[go: up one dir, main page]

WO2015025818A1 - Dispositif de commande hydraulique pour machine de travail - Google Patents

Dispositif de commande hydraulique pour machine de travail Download PDF

Info

Publication number
WO2015025818A1
WO2015025818A1 PCT/JP2014/071575 JP2014071575W WO2015025818A1 WO 2015025818 A1 WO2015025818 A1 WO 2015025818A1 JP 2014071575 W JP2014071575 W JP 2014071575W WO 2015025818 A1 WO2015025818 A1 WO 2015025818A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
target
hydraulic
speed
unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2014/071575
Other languages
English (en)
Japanese (ja)
Inventor
宇田川　勉
石川　広二
中山　晃
枝穂 泉
亮平 山下
秀一 森木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Construction Machinery Co Ltd
Original Assignee
Hitachi Construction Machinery Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Construction Machinery Co Ltd filed Critical Hitachi Construction Machinery Co Ltd
Publication of WO2015025818A1 publication Critical patent/WO2015025818A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
    • E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2296—Systems with a variable displacement pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3138—Directional control characterised by the positions of the valve element the positions being discrete
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/426—Flow control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/455—Control of flow in the feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6336—Electronic controllers using input signals representing a state of the output member, e.g. position, speed or acceleration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6652—Control of the pressure source, e.g. control of the swash plate angle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6654—Flow rate control

Definitions

  • the present invention relates to a hydraulic control device for a work machine that is provided in a work machine such as a hydraulic excavator and is suitable for driving the work machine by discharging hydraulic oil from a hydraulic pump to a plurality of hydraulic actuators.
  • a work machine such as a hydraulic excavator or a wheel loader includes a plurality of hydraulic actuators such as hydraulic cylinders that are operated by hydraulic oil discharged as pressure oil from a hydraulic pump, and an operation device that operates these hydraulic actuators.
  • the hydraulic oil is distributed to the hydraulic actuators according to the operation input of the operating device, so that the turning operation of the turning body and the turning operation of the boom and the like are performed in a composite manner.
  • this ultra-small swivel hydraulic working machine of the prior art includes a hydraulic pump and a plurality of hydraulic actuators such as a swing motor and a boom cylinder, as well as hydraulic fluid discharged from the hydraulic pump to each hydraulic actuator.
  • a directional control valve for controlling the flow, a pressure compensation valve for controlling the pressure of hydraulic oil discharged from the hydraulic pump to each hydraulic actuator, and the discharge pressure of the hydraulic pump and the load pressure of each hydraulic actuator are set to a predetermined differential pressure.
  • a pump capacity control cylinder to be maintained and a discharge amount control unit such as a load sensing valve are provided.
  • the pressure compensation valve keeps the differential pressure before and after the directional control valve constant, and the discharge amount control unit is higher than the load pressure of the highest hydraulic actuator among the multiple hydraulic actuators by the target differential pressure, that is, the load sensing differential pressure.
  • each operation part driven by each hydraulic actuator has its own weight, the inertial mass of the work object, and the load due to the reaction force received from the work object.
  • the same characteristics as described above are not always required for the part.
  • a bucket having a relatively high speed controllability is relatively preferred, but a swinging device, a boom, etc. preferably have a good force controllability in addition to the speed controllability.
  • the conventional ultra-small swivel hydraulic working machine is one in which an operator operates each operating part by operating an operating device, so that even if it has excellent speed controllability, force controllability is obtained. Otherwise, it is required to operate carefully so that the revolving body and boom do not suddenly start or stop suddenly, and there is a concern that the operating performance of the operating device will deteriorate.
  • the flow rate controllability of hydraulic fluid flowing into each hydraulic actuator of a work machine to which a load sensing system is applied is a directional control valve based on an operation input of an operating device. This is determined by the response of the spool and the pressure control response of the pressure compensation valve. Therefore, if there is no dynamic delay in the operation of the spool of the directional control valve with respect to the operation input of the operating device, the flow rate controllability of the hydraulic oil is determined by the pressure control response of the pressure compensation valve.
  • the valve has a characteristic of quickly following the speed of each hydraulic actuator. Therefore, if the response of the pressure control of the pressure compensation valve can be freely set and the operation of the pressure control valve can be delayed with respect to the speed of each hydraulic actuator, it is considered that the operation performance of the operating device can be improved.
  • the following characteristics of the pressure compensation valve are composed of components such as the force acting on the pressure receiving portion of the pressure compensation valve, the elastic force of the spring acting on the pressure compensation valve, the mass of the pressure compensation valve, and the pressure transmission circuit.
  • the pressure compensation valve operates quickly with respect to the speed of each hydraulic actuator by such a hardware configuration that cannot be changed easily, so that the pressure control response of the pressure compensation valve can be freely set It is difficult to improve the operating performance of the operating device.
  • the present invention has been made based on the actual situation of the prior art as described above, and its object is to sufficiently improve the force controllability while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device.
  • An object of the present invention is to provide a hydraulic control device for a working machine.
  • a hydraulic control device for a work machine includes a hydraulic pump driven by a prime mover, a plurality of hydraulic actuators operated by hydraulic oil discharged from the hydraulic pump, and the hydraulic pressures thereof.
  • a hydraulic control unit that is provided in a work machine including an operation device that operates an actuator, and that controls an operation flow from the hydraulic pump to the plurality of hydraulic actuators in response to an operation input from the operation device;
  • a discharge pressure detection unit that detects a discharge pressure of the hydraulic pump
  • a speed detection unit that detects a speed of the plurality of hydraulic actuators, and a hydraulic fluid flowing into the plurality of hydraulic actuators
  • a plurality of hydraulic actuators based on an inflow control unit for controlling pressure and an operation amount operated by the operation device.
  • a plurality of hydraulic actuators based on the target speed calculation unit that calculates a target value of the speed at which the motor is operated, the speed detected by the speed detection unit, and the target value calculated by the target speed calculation unit A target driving pressure calculating unit that calculates a target value of a driving pressure for driving the hydraulic pressure, and the hydraulic pressure according to the discharge pressure detected by the discharge pressure detecting unit and the target value calculated by the target driving pressure calculating unit.
  • a target discharge amount calculation unit that calculates a target value of the pump discharge amount, and the inflow control unit flows into the plurality of hydraulic actuators according to the target value calculated by the target drive pressure calculation unit While controlling the pressure of hydraulic fluid, the hydraulic control unit controls the discharge amount of the hydraulic pump to the target value calculated by the target discharge amount calculation unit. It is characterized.
  • the target speed calculation unit calculates the target value of the speed for operating each hydraulic actuator based on the operation amount operated by the operation device.
  • the target drive pressure calculator calculates the detected speed of each hydraulic actuator and the target calculated by the target speed calculator. Based on the value, the target value of the driving pressure of each hydraulic actuator can be calculated.
  • the discharge pressure detection unit detects the discharge pressure of the hydraulic pump
  • the discharge amount calculation unit according to the detected discharge pressure of the hydraulic pump and the target value calculated by the target drive pressure calculation unit, The target value of the discharge amount of the hydraulic pump is calculated, and the hydraulic control unit controls the discharge amount of the hydraulic pump to the calculated target value.
  • hydraulic oil having a flow rate corresponding to this target value is discharged as pressure oil from the hydraulic pump toward each hydraulic actuator into the hydraulic circuit, so that the discharged hydraulic oil is arranged upstream of each hydraulic actuator. Flow into the inflow control unit.
  • each hydraulic actuator can be appropriately operated. Therefore, the force controllability can be sufficiently improved while ensuring the speed controllability of the hydraulic actuator with respect to the operation input of the operation device.
  • the hydraulic control device for a work machine further includes a pressure limiting unit that sets an upper limit pressure of the driving pressure based on the operation amount operated by the operating device, and the target driving pressure calculation
  • the unit is configured to determine the driving pressure based on the speed detected by the speed detecting unit, the target value calculated by the target speed calculating unit, and an upper limit pressure of the driving pressure set by the pressure limiting unit. It is characterized by calculating a target value.
  • the drive pressure required for each hydraulic actuator to obtain the target value speed calculated by the target speed calculation unit with respect to the operation amount of the operating device is set by the pressure limiting unit. Since the pressure exceeding the upper limit of the drive pressure does not act on each hydraulic actuator even when the upper limit is exceeded, the driving force of each hydraulic actuator depends on the operation amount of the operating device. Can be suppressed, and high force controllability can be obtained.
  • the driving pressure required for each hydraulic actuator to obtain the target speed calculated by the target speed calculator with respect to the operation amount of the operating device is the upper limit pressure of the driving pressure set by the pressure limiter.
  • the drive pressure of the hydraulic actuator is not limited and the drive force of each hydraulic actuator is not suppressed in the calculation process of the target drive pressure calculation unit, excellent speed controllability can be obtained.
  • the target drive pressure calculation unit uses the target discharge amount as a calculation result that is a value lower than the target value of the calculated drive pressure by a predetermined value. It is characterized by being output to a calculation unit.
  • the discharge pressure of the hydraulic pump is lower by a predetermined value than the drive pressure of the hydraulic actuator for which the highest target value has been calculated by the target drive pressure calculation unit among the plurality of hydraulic actuators.
  • the inflow control unit that controls the driving pressure of the engine can maximize the opening area, and can minimize resistance generated when hydraulic fluid passes, that is, pressure loss.
  • the relationship between the operation amount operated by the operation device and the target value calculated by the target speed calculation unit is stored in advance.
  • a relationship correction unit that corrects the relationship stored in the storage unit according to the target value calculated by the target drive pressure calculation unit, and the target speed calculation unit is corrected by the relationship correction unit.
  • the target value is calculated by applying the operation amount operated by the operation device to the relationship.
  • the relationship correction unit is stored in the storage unit.
  • the target value of the speed of each hydraulic actuator can be obtained with respect to the operation amount of the operating device. Thereby, the operation feeling of the operating device can be easily adjusted for each hydraulic actuator.
  • the inflow control unit is provided between the hydraulic pump and the plurality of hydraulic actuators, and controls the pressure of hydraulic fluid that passes therethrough. It includes a control valve, and the pressure control valve is driven by receiving an input signal from the outside, and the opening amount is decreased as the input signal increases.
  • the hydraulic control unit is configured to generate a target drive pressure based on the speed of each hydraulic actuator detected by the speed detection unit and the target value of the speed calculated by the target speed calculation unit.
  • the pressure corresponding to the target value calculated by the calculation unit can be appropriately applied to each hydraulic actuator via the inflow control unit by adjusting the discharge amount of the hydraulic pump by the target discharge amount control unit. Therefore, the driving force of each hydraulic actuator can be suppressed according to the operation amount of the operating device, and the force controllability is sufficiently improved while ensuring the speed controllability of the hydraulic actuator for the operation input of the operating device. be able to. Accordingly, stable operation of each hydraulic actuator can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation device can be improved, and the work efficiency of the work machine can be improved as compared with the conventional case.
  • FIG. 3 It is a figure showing a hydraulic excavator mentioned as an example of a working machine with which a 1st embodiment of a hydraulic control device concerning the present invention is provided. It is a figure showing composition of a 1st embodiment of a hydraulic control device of a working machine concerning the present invention. It is a figure which shows the structure of the controller with which 1st Embodiment of this invention was equipped. It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each functional relationship of the target speed table regarding an especially turning motor, and an upper limit pressure table. It is a figure which shows the principal part of the controller shown in FIG. 3, and is a figure explaining each function relationship of the target speed table and upper limit pressure table regarding especially a boom cylinder.
  • a figure shows the structure of the electromagnetic proportional pressure reducing valve which comprises an inflow control part
  • the figure is an electromagnetic proportional pressure reduction. It is a figure which shows the characteristic of a valve. It is a figure which shows the structure of the controller with which 2nd Embodiment of this invention was equipped. It is a figure explaining the functional relationship of the target speed table regarding the turning motor correct
  • a figure shows the structure of the electromagnetic proportional throttle valve which comprises an inflow control part
  • the figure is an electromagnetic proportional throttle It is a figure which shows the characteristic of a valve. It is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
  • the first embodiment of the hydraulic control apparatus according to the present invention is applied to a work machine, for example, a hydraulic excavator 1 shown in FIG.
  • the hydraulic excavator 1 includes a traveling body 2, a revolving body 3 attached to the upper side of the traveling body 2 via a revolving device 3A, and a revolving body 3 mounted in front of the revolving body 3 so as to rotate in the vertical direction.
  • the front work machine 4 is configured.
  • the front work machine 4 includes a boom 4A whose base end is pivotally attached to the swing body 3 and pivots in the vertical direction, an arm 4B pivotally attached to the tip of the boom 4A, and the arm And a bucket 4C rotatably attached to the tip of 4B.
  • the swivel body 3 is arranged at the front, a cab 7 disposed at the rear, a counterweight 6 disposed at the rear to maintain the balance of the vehicle body, and disposed between the cab 7 and the counterweight 6, and an engine 11 (see FIG. 2) and an engine speed detector 11A (see FIG. 2) that is attached to the engine 11 in the engine room 5 and detects the speed of the engine 11.
  • the rotating body 3 is rotated by a driving force of the engine 11, and a variable displacement swash plate hydraulic pump (hereinafter referred to as hydraulic pressure for convenience) that discharges hydraulic oil as pressure oil for driving the front work machine 4.
  • a pump a tilt amount adjusting unit 12 A that adjusts the tilt amount by changing the tilt angle of a swash plate (not shown) with respect to the rotating shaft of the hydraulic pump 12, and the hydraulic pump 12
  • hydraulic oil tank 13 that stores the hydraulic oil to be sucked in and a plurality of hydraulic actuators that are operated by the hydraulic oil discharged from the hydraulic pump 12.
  • the hydraulic pump 12 is not limited to the swash plate type, and other variable displacement mechanisms such as a swash shaft type may be used.
  • These hydraulic actuators are arranged on the upper side of the boom 4A, for example, a swing motor 3a that drives the swing device 3A, a swing cylinder 3 that connects the swing body 3 and the boom 4A, and rotates the boom 4A by extending and contracting.
  • a swing motor 3a that drives the swing device 3A
  • a swing cylinder 3 that connects the swing body 3 and the boom 4A
  • rotates the boom 4A by extending and contracting At the same time, the boom cylinder 4A and the arm 4B are connected, and the arm cylinder 4b that rotates the arm 4B by extending and contracting, and the bucket cylinder that connects the arm 4B and the bucket 4C and rotating the bucket 4C by expanding and contracting. 4c.
  • the swing body 3 is connected between the hydraulic pump 12 and each swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4c, and controls the flow of hydraulic oil discharged from the hydraulic pump 12.
  • Control valves 16A to 16D are provided.
  • Each of the directional control valves 16A to 16D is, for example, a closed center type having no center bypass oil passage and does not include a bleed-off circuit.
  • the cab 7 includes an operation seat (not shown) on which an operator is seated, and an operation device that is provided in the vicinity of the operation seat and operates each of the hydraulic actuators 3a, 4a to 4c.
  • a left operation lever 15A that is disposed on the left side of the driver's seat and that rotates the swivel device 3A to the left or right, or that rotates the arm in the vertical direction.
  • a pilot pump (not shown).
  • the left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the directional control valve 16A on the swing motor 3a side.
  • the pressure of pilot pressure oil supplied to each pressure receiving chamber of the direction control valve 16A, that is, the pilot pressure is adjusted according to the amount of operation and received, and the pilot pressure is applied to the direction control valve 16A to change the switching position of the direction control valve 16A. I try to switch.
  • the left operation lever 15A is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16C on the arm cylinder 4b side, and the pilot pressure oil guided from the pilot pump is operated in the front / rear direction among the front / rear and left / right directions.
  • the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16C is adjusted according to the operation amount, and the pilot pressure is applied to the direction control valve 16C to switch the switching position of the direction control valve 16C. . Therefore, the operator rotates the arm 4B in the vertical direction by operating the left operation lever 15A in the left-right direction to turn the turning device 3A in the left-right direction, or operating the left operation lever 15A in the front-rear direction. Can be moved.
  • the right operation lever 15B is connected to the left and right pressure receiving chambers of the direction control valve 16B on the boom cylinder 4a side, for example, and inputs pilot pressure oil guided from the pilot pump in the front / rear direction among the front / rear and left / right directions.
  • the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16B is adjusted according to the amount of operation received, and the pilot pressure is applied to the direction control valve 16B to switch the switching position of the direction control valve 16B.
  • the right operation lever 15B is connected to, for example, the left and right pressure receiving chambers of the direction control valve 16D on the bucket cylinder 4c side, and adjusts the pilot pressure supplied to each pressure receiving chamber of the direction control valve 16D according to the operation amount.
  • the pilot pressure is applied to the direction control valve 16D to switch the switching position of the direction control valve 16D. Therefore, the operator operates the right operation lever 15B in the front-rear direction to rotate the boom 4A in the vertical direction, or operates the right operation lever 15B in the left-right direction to move the bucket 4C in the vertical direction. It can be rotated.
  • the operation amount of each operation lever 15A, 15B is a positive value when, for example, the operation direction is the left direction or the front direction, and is negative when the operation direction of each operation lever 15A, 15B is the right direction or the rear direction. Value.
  • the left operation lever 15A and the right operation lever 15B are provided with operation amount sensors 15A1 and 15B1 as operation amount detection units for detecting an operation amount, respectively.
  • the pilot pressure of the pilot pressure oil supplied from the levers 15A and 15B to the pressure receiving chambers of the direction control valves 16A to 16D is detected as an operation amount.
  • a discharge pressure sensor 17 serving as a discharge pressure detection unit for detecting the discharge pressure of the hydraulic pump 12 is provided in a pipe line connecting the directional control valves 16A to 16D and the hydraulic pump 12.
  • Speed sensors 18A to 18D as speed detectors for detecting the speeds of the hydraulic actuators 3a and 4a to 4c
  • inflow control for controlling the pressure of hydraulic oil flowing into the hydraulic actuators 3a and 4a to 4c, that is, driving pressure.
  • the first embodiment of the present invention is a hydraulic control unit that controls the flow rate of hydraulic oil discharged from the hydraulic pump 12 to the hydraulic actuators 3a, 4a to 4c in response to operation inputs from the operation levers 15A and 15B.
  • the controller 20 is connected to operation amount sensors 15A1 and 15B1, a discharge pressure sensor 17, speed sensors 18A to 18D, a tilt amount adjustment unit 12A, and inflow control units 19A to 19D. Yes.
  • the configuration of the controller 20 according to the first embodiment of the present invention will be described in detail with reference to FIG. 3, but the control of the arm cylinder 4b and the bucket cylinder 4c is performed similarly to the control of the boom cylinder 4a. A description of the configuration and operation related to the control of the arm cylinder 4b and the bucket cylinder 4c is omitted.
  • the controller 20 sets a target value (hereinafter referred to as a convenience) of a speed at which the turning motor 3a is operated based on an operation amount operated by the left operation lever 15A, that is, an operation amount detected by the operation amount sensor 15A1. (Referred to as a target turning speed) and a driving pressure for driving the turning motor 3a based on the operation amount operated by the operation amount sensor 15A1 (hereinafter referred to as a turning driving pressure for convenience).
  • Pressure limiter 25A2 for setting the upper limit pressure
  • the speed of the swing motor 3a detected by the speed sensor 18A the target swing speed calculated by the target speed calculator 25A1, and the swing set by the pressure limiter 25A2.
  • the target value of the drive pressure of the swing motor 3a (hereinafter referred to as the target swing drive pressure for convenience). And a target driving pressure calculating section 26A for calculating a.
  • the pressure limiter 25A2 may be omitted regardless of whether the pressure limiter 25A2 is included.
  • the controller 20 Based on the operation amount operated by the right operation lever 15B, that is, the operation amount detected by the operation amount sensor 15B1, the controller 20 sets a target value of the speed for operating the boom cylinder 4a (hereinafter referred to as a target boom speed for convenience).
  • the upper limit pressure of the driving pressure for driving the boom cylinder 4a (hereinafter referred to as the boom driving pressure for convenience) is determined based on the operation amount detected by the target speed calculation unit 25B1 and the operation amount sensor 15B1.
  • the speed limit unit 25B2 to be set, the speed of the boom cylinder 4a detected by the speed sensor 18B, the target boom speed calculated by the target speed calculation unit 25B1, and the upper limit pressure of the boom drive pressure set by the pressure limit unit 25B2 Based on the target value of the drive pressure of the boom cylinder 4a (hereinafter, the target boom drive And a target driving pressure calculating unit 26B for calculating referred to as pressure).
  • the pressure limiter 25B2 may be omitted regardless of whether the pressure limiter 25B2 is included.
  • the controller 20 discharges the hydraulic pump 12 according to the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target swing drive pressure and target boom drive pressure calculated by the target drive pressure calculation units 26A and 26B.
  • a target discharge amount calculation unit 30 for calculating a target value of the amount (hereinafter referred to as a target discharge amount for convenience) is provided.
  • inflow control part 19A, 19B is the pressure of the hydraulic fluid which flows in into each turning motor 3a and boom cylinder 4a according to the target turning drive pressure and target boom drive pressure which were calculated by target drive pressure calculating part 26A, 26B. That is, the controller 20 controls the drive pressure and sets the flow rate according to the drive pressure, and the controller 20 controls the discharge amount of the hydraulic pump 12 to the target discharge amount calculated by the target discharge amount calculation unit 30. Yes.
  • the inflow control units 19A and 19B set the flow rates of the hydraulic oil flowing into the swing motors 3a and the boom cylinders 4a, the directional control valves 16A and 16B are connected to the actuators 3a and 4a.
  • the main function is to switch the direction of hydraulic oil outflow, and the throttle function for setting the flow rate for each actuator 3a, 4a of the normal directional control valve reduces the influence.
  • target speed calculation units 25A1, 25B1, pressure limiting units 25A2, 25B2, target drive pressure calculation units 26A, 26B, target discharge amount calculation unit 30, and inflow control units 19A, 19B according to the first embodiment of the present invention.
  • the specific configuration of will be described.
  • a target speed table 25a1 shown in FIG. 4 is stored in advance as the relationship between the operation amount operated by the left operation lever 15A and the target turning speed calculated by the target speed calculation unit 25A1.
  • a storage unit 25a3 is provided, and this storage unit 25a3 is stored, for example, inside the target speed calculation unit 25A1.
  • the functional relationship of the target speed table 25a1 has a minimum value VRmin and a maximum value VRmax, and the absolute value of the slope of the target turning speed VR with respect to the operation amount XL increases stepwise as the absolute value of the operation amount XL increases. It is set to be.
  • the target speed calculation unit 25A1 calculates the target turning speed by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 set in this way.
  • an upper limit pressure table 25a2 shown in FIG. 4 is previously stored as the relationship between the operation amount operated by the left operation lever 15A and the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2.
  • the storage unit 25a4 is stored, and the storage unit 25a4 is stored, for example, inside the pressure limiting unit 25A2.
  • the functional relationship of the upper limit pressure table 25a2 has a minimum value PRmin (> 0) and a maximum value PRmax, and the slope of the upper limit pressure PR of the swing drive pressure with respect to the operation amount XL increases as the absolute value of the operation amount XL increases.
  • the absolute value is set to increase stepwise.
  • the pressure limiter 25A2 sets the upper limit pressure of the turning drive pressure by applying the operation amount detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2 set in this way.
  • the target drive pressure calculator 26A is configured to perform proportional control, differential control, based on the deviation between the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the speed deviation.
  • a PID control unit 26A1 that performs PID control combined with integral control, and a turning drive connected to the PID control unit 26A1 and the pressure limiting unit 25A2 and set by the pressure limiting unit 25A2 with respect to the output value of the PID control unit 26A1
  • a limiter processing unit 26A2 for performing a limiter process for limiting the upper limit pressure.
  • the PID controller 26A1 eliminates the speed deviation by performing PID control on the speed of the swing motor 3a detected by the speed sensor 18A and the target swing speed calculated by the target speed calculator 25A1, that is, the swing motor.
  • the turning driving pressure required to make the speed 3a coincide with the target turning speed is calculated and output to the limiter processing unit 26A2.
  • the PID control unit 26A1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26A1 is not limited to PID.
  • the limiter processing unit 26A2 compares the turning drive pressure calculated by the PID control unit 26A1 with the upper limit pressure of the turning drive pressure set by the pressure limiting unit 25A2, and the turning drive pressure calculated by the PID control unit 26A1 is the pressure. If the upper limit pressure of the turning drive pressure set by the restriction unit 25A2 is greater than the upper limit pressure of the turning drive pressure, the calculation is performed with the upper limit pressure of the turning drive pressure set by the pressure restriction unit 25A2 as the target turning drive pressure.
  • the limiter processing unit 26A2 determines the swing drive pressure calculated by the PID control unit 26A1 if the swing drive pressure calculated by the PID control unit 26A1 is equal to or lower than the upper limit pressure of the swing drive pressure set by the pressure limiting unit 25A2. Is calculated to be a target turning drive pressure. Note that the maximum value PRmax of the upper limit pressure of the turning drive pressure described above is set to be larger than the turning drive pressure calculated by the PID control unit 26A1.
  • the limiter processing unit 26A2 outputs the calculated target turning drive pressure as a command current to the inflow control unit 19A, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target turning drive pressure. The data is output to the calculation unit 30. The reason for using the predetermined value will be described later. When this calculation result becomes a negative value, the limiter processing unit 26A2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
  • a target speed table 25b1 shown in FIG. 5 is used as the relationship between the operation amount operated by the right operation lever 15B and the target boom speed calculated by the target speed calculation unit 25B1.
  • the storage unit 25b3 is stored in advance, and the storage unit 25b3 is stored in, for example, the target speed calculation unit 25B1.
  • the target speed table 25b1 of the target speed calculation unit 25B1 has a functional relationship in which the target boom speed VB increases as the operation amount XR increases, and this functional relationship indicates that the boom 4A is rotated with respect to the turning operation of the boom 4A. Since the required performance differs depending on the operation direction such as raising and lowering the boom 4A, it is set according to the operation direction and the operation amount of the right operation lever 15B.
  • the target speed table 25b1 has a minimum value VBmin and a maximum value VBmax so that the absolute value of the gradient of the target boom speed VB with respect to the operation amount XR increases stepwise as the absolute value of the operation amount XR increases. It has become.
  • the target speed calculation unit 25B1 calculates the target boom speed by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 set in this way.
  • an upper limit pressure table 25b2 shown in FIG. 5 is previously stored as the relationship between the operation amount operated by the right operation lever 15B and the upper limit pressure of the boom drive pressure set by the pressure limiting unit 25B2.
  • the storage unit 25b4 is stored, and the storage unit 25b4 is stored, for example, inside the pressure limiting unit 25B2.
  • the upper limit pressure table 25b2 of the pressure limiting unit 25B2 has a functional relationship in which the upper limit pressure PB of the boom driving pressure increases as the absolute value of the operation amount XR increases. This functional relationship is the rotation of the boom 4A as described above. Since the required performance differs depending on the operation direction such as raising the boom 4A and lowering the boom 4A with respect to the moving operation, the setting is set according to the operation direction and the operation amount of the right operation lever 15B.
  • the line target is set.
  • the functional relationship of the upper limit pressure table 25b2 has a minimum value PBmin (> 0) and a maximum value PBmax, and the gradient of the upper limit pressure PB of the boom drive pressure with respect to the operation amount XR is stepped as the absolute value of the operation amount XR increases. Is set to increase.
  • the pressure limiting unit 25B2 sets the upper limit pressure of the boom driving pressure by applying the operation amount detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2 set in this way.
  • the target drive pressure calculator 26B performs proportional control, differential control, and integral control based on the deviation between the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculator 25B1.
  • a PID control unit 26B1 that performs combined PID control, and an upper limit pressure of the boom drive pressure that is connected to the PID control unit 26B1 and the pressure limiting unit 25B2 and set by the pressure limiting unit 25B2 with respect to the output value of the PID control unit 26B1
  • a limiter processing unit 26B2 for performing a limiter process for adding the above limitation.
  • the PID control unit 26B1 eliminates the speed deviation by performing PID control on the speed of the boom cylinder 4a detected by the speed sensor 18B and the target boom speed calculated by the target speed calculation unit 25B1, that is, the boom cylinder
  • the boom driving pressure required to match the speed 4a with the target boom speed is calculated and output to the limiter processing unit 26B2.
  • the PID control unit 26B1 uses PID control, but any control method can be used as long as the output value can follow the target value, and the PID control unit 26B1 is not limited to PID.
  • the limiter processing unit 26B2 compares the boom driving pressure calculated by the PID control unit 26B1 with the upper limit pressure of the boom driving pressure set by the pressure limiting unit 25B2, and the boom driving pressure calculated by the PID control unit 26B1 is the pressure. If the upper limit pressure of the boom drive pressure set by the limiter 25B2 is greater than the upper limit pressure of the boom drive pressure, the calculation is performed with the upper limit pressure of the boom drive pressure set by the pressure limiter 25B2 as the target boom drive pressure.
  • the limiter processing unit 26B2 may calculate the boom driving pressure calculated by the PID control unit 26B1. -Calculates the target boom drive pressure. Further, the limiter processing unit 26B2 outputs the calculated target boom driving pressure as a command current to the inflow control unit 19B, and calculates a target discharge amount as a calculation result that is a predetermined value, for example, 1 MPa lower than the calculated target boom driving pressure. The data is output to the calculation unit 30. When the calculation result becomes a negative value, the limiter processing unit 26B2 regards it as 0 MPa and outputs it to the target discharge amount calculation unit 30.
  • the target discharge amount calculation unit 30 is based on an input value input from the limiter processing unit 26A2 and an input value input from the limiter processing unit 26B2.
  • a target discharge pressure calculation unit selects the maximum target discharge pressure as the target discharge pressure of the hydraulic pump 12 by selecting the larger one of the input value input from the limiter processing unit 26A2 and the input value input from the limiter processing unit 26B2, for example. It consists of part 30A.
  • the target discharge amount calculation unit 30 is, for example, similar to the PID control units 26A1 and 26B1 described above, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 selected by the maximum target discharge pressure selection unit 30A.
  • a PID control unit 30B that performs PID control based on a deviation from the target discharge pressure, and a target discharge amount correction unit 30C that corrects the output value of the PID control unit 30B with the rotational speed of the engine 11. Yes.
  • the PID control unit 30B performs hydraulic pressure control by performing PID control on the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the target discharge pressure of the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the pump 12 coincide with the target discharge pressure is calculated and output to the target discharge amount correction unit 30C.
  • the target discharge amount correction unit 30C calculates the target discharge amount by dividing the discharge amount input from the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A.
  • the target discharge amount is output to the tilt amount adjustment unit 12A.
  • Each inflow control unit 19A, 19B is provided between, for example, the hydraulic pump 12, the turning motor 3a, and the boom cylinder 4a, and is a pressure control valve that controls the pressure of hydraulic fluid that passes as shown in FIG. 6 (a).
  • electromagnetic proportional pressure reducing valves 19A1 and 19B1 As electromagnetic proportional pressure reducing valves 19A1 and 19B1.
  • Each of the electromagnetic proportional pressure reducing valves 19A1, 19B1 is driven by receiving a command current for the target turning driving pressure and the target boom driving pressure input from the external limiter processing units 26A2, 26B2, and decreases the opening amount as the command current increases. I am doing so.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 of the inflow control units 19A and 19B are, for example, directions in which the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a and boom cylinder 4a side) communicate with each other.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (swing motor 3a, 19b2) when the magnitude of the command current I to the electromagnetic solenoids 19a2 and 19b2 is less than a predetermined current value IA.
  • the set pressure PS on the boom cylinder 4a side is the maximum value PSmax and the magnitude of the command current I is equal to or greater than the predetermined current value IA
  • the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) is
  • the opening is set so that the set pressure PS on the secondary side (the swing motor 3a side and the boom cylinder 4a side) becomes 0A. The amount is adjusted.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the primary side (hydraulic pump 12 side) and the secondary side by the elastic force of the springs 19a1 and 19b1.
  • the command current I is greater than or equal to a predetermined current value IA while keeping the switching position (the D position shown in FIG. 6A) in which the (turning motor 3a, boom cylinder 4a side) communicates
  • the springs 19a1 and 19b1 The main body moves against the elastic force, and is switched to a switching position (E position shown in FIG. 6A) where the hydraulic oil tank 13 communicates.
  • Each of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 causes the secondary side (swing motor 3a, boom cylinder 4a side) hydraulic oil to act against the elastic force of the springs 19a1 and 19b1, thereby rotating the secondary side (swinging).
  • the hydraulic oil in the motor 3a and boom cylinder 4a side becomes excessive, the hydraulic oil is allowed to flow out to the hydraulic oil tank 13.
  • the tilt amount control unit 12A receives the target discharge amount from the target discharge amount correction unit 30C, and adjusts the tilt amount of the hydraulic pump 12 according to the target discharge amount, thereby adjusting the discharge amount of the hydraulic pump 12 to the target discharge.
  • the target discharge amount corrected by the amount correction unit 30C is controlled.
  • the operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right to make the pilot pressure of the pilot pressure oil discharged from the pilot pump maximum, and this pilot pressure is reduced. Since it acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (position A shown in FIG. 2) or the right position (FIG. 2). (C position shown), and the opening amount of the direction control valve 16A is maximized.
  • the speed sensor 18 ⁇ / b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed VRmax calculated by the target speed calculation unit 25A1, thereby matching the speed of the turning motor 3a with the target turning speed VRmax.
  • the required turning drive pressure Px is obtained, and the calculation result is output to the limiter processing unit 26A2 of the target drive pressure calculation unit 26A.
  • the limiter processing unit 26A2 compares the swing drive pressure Px calculated by the PID control unit 26A1 with the upper limit pressure PRmax of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, since the upper limit pressure PRmax of the turning drive pressure set by the pressure limiting unit 25A2 is the maximum value, the turning drive pressure Px calculated by the PID control unit 26A1 is set by the pressure limiting unit 25A2.
  • the upper limit pressure PRmax of the turning drive pressure is not more than the upper limit pressure PRmax and is not restricted by the pressure restriction unit 25A2.
  • the limiter processing unit 26A2 obtains the turning drive pressure Px calculated by the PID control unit 26A1 as it is as the target turning drive pressure.
  • the subtracted calculation result is output to the target discharge amount calculation unit 30 of the controller 20.
  • the speed sensor 18B detects the speed of the boom cylinder 4a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • PB PBmin
  • the unit of boom speed is normally described by m / s etc., it abbreviate
  • the limiter processing unit 26B2 When the limiter processing unit 26B2 inputs the calculation result from the PID control unit 26B1, the limiter processing unit 26B2 compares the boom driving pressure (0 MPa) calculated by the PID control unit 26B1 with the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2. . At this time, as described above, the boom driving pressure calculated by the PID control unit 26B1 is 0 MPa, and the upper limit pressure PBmin of the boom driving pressure set by the pressure limiting unit 25B2 is the minimum value and larger than 0 MPa. 26B2 calculates
  • the limiter processing unit 26B2 outputs the maximum value Imax corresponding to the target boom drive pressure (0 MPa) as the command current I to the inflow control unit 19B, and subtracts the predetermined value 1 MPa from the target boom drive pressure (0 MPa).
  • the calculation result is output to the target discharge amount calculation unit 30. Since the calculation result output at this time is a negative value, 0 MPa is output.
  • the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared.
  • the input value input from the limiter processing unit 26A2 is a value obtained by subtracting 1 MPa from the turning drive pressure Px calculated by the PID control unit 26A1 ((Px ⁇ 1) MPa), and is 0 MPa or more. Therefore, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2.
  • the maximum target discharge pressure selection unit 30A selects the input value ((Px-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and the calculation result is the target discharge amount calculation unit. It outputs to 30 PID control part 30B.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((Px-1) MPa)
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current Ix (0 ⁇ Ix ⁇ Imax) from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is adjusted. Is controlled to be the pressure Px corresponding to the command current Ix, that is, the turning drive pressure Px calculated by the PID control unit 26A1.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((Px-1) MPa) obtained by subtracting a predetermined value 1 MPa from the swing drive pressure Px calculated by the PID control unit 26A1, and the discharge amount of the swing motor 3a
  • the flow rate makes the speed coincide with the target turning speed VRmax.
  • the inflow control unit 19A controls the pressure on the secondary side (the swing motor 3a side) to be the swing drive pressure Px calculated by the PID control unit 26A1, and the swing motor 3a via the direction control valve 16A.
  • the pressure ((Px-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure Px on the secondary side (swing motor 3a side) by a predetermined value 1 MPa
  • the pressure generated on the secondary side of the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A shown in FIG. 6A is smaller than the set pressure Px by a predetermined value 1 MPa.
  • the secondary pressure fed back to the electromagnetic proportional pressure reducing valve 19A1 (the broken line portion in FIG. 6A) is also smaller than the set pressure Px by a predetermined value 1 MPa, so that the spring switching position is that of the electromagnetic proportional pressure reducing valve 19A1.
  • the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if hydraulic fluid is discharged from the boom cylinder 4a to the boom cylinder 4a, the hydraulic fluid is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
  • the operator seated on the driving seat in the cab 7 operates the left operating lever 15A to the left or right by a half lever, so that the pilot pressure oil discharged from the pilot pump according to the operating amount of the left operating lever 15A is obtained. Is depressurized. Since the pilot pressure of this pilot pressure oil acts on the direction control valve 16A on the swing motor 3a side, the switching position of the direction control valve 16A is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). (A position) or right position (C position shown in FIG. 2), the direction control valve 16A opens according to the operation amount of the left operation lever 15A.
  • the speed sensor 18 ⁇ / b> A detects the speed of the turning motor 3 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the pressure limiting unit 25A2 of the controller 20 applies the operation amount X1 detected by the operation amount sensor 15A1 to the functional relationship of the upper limit pressure table 25a2, thereby setting the upper limit pressure PR of the turning drive pressure to the minimum value PRmin.
  • the PID controller 26A1 of the target drive pressure calculator 26A PID control is performed on the speed of the turning motor 3a detected by the sensor 18A and the target turning speed V1 (0 ⁇ V1 ⁇ VRmax) calculated by the target speed calculation unit 25A1, thereby eliminating the speed deviation, that is, turning A turning drive pressure Py required to make the speed of the motor 3a coincide with the target turning speed V1 (0 ⁇ V1 ⁇ VRmax) is obtained.
  • the set pressure of the relief valve 21 is set to PrL larger than the above-described pressure P1 (PRmin ⁇ P1 ⁇ PRmax) in the upper limit pressure table 25a2 (P1 ⁇ PrL).
  • the set pressure PrL is set as the upper limit value of the PID control unit 26A1
  • the PID control unit 26A1 since the PID control unit 26A1 has a large inertia load, the speed deviation between the target speed obtained by the target speed calculation unit 25A1 and the speed detected by the speed sensor 18 Since it takes time to eliminate the rotation, the turning drive pressure Py reaches PrL, and this calculation result is used as the limiter processing unit 2 of the target drive pressure calculation unit 26A. And outputs it to the A2.
  • the target drive pressure of each actuator does not exceed the relief setting pressure PrL by setting the maximum value PRmax of the upper limit pressure to a value equal to or less than the relief setting pressure PrL, and thus exceeds the normal relief setting pressure PrL.
  • the flow rate discharged from the relief valve 21 to the hydraulic oil tank 13 can be suppressed, and an energy saving effect can be obtained.
  • the limiter processing unit 26A2 compares the swing drive pressure PrL calculated by the PID control unit 26A1 with the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. At this time, as described above, the turning drive pressure PrL calculated by the PID control unit 26A1 is larger than the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 (P1 ⁇ PrL), so the PID control unit 26A1. The calculated turning drive pressure PrL is limited by the pressure limiting unit 25A2.
  • the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value (0 MPa) input from the limiter processing unit 26B2 is compared.
  • the input value ((P1-1) MPa) input from the limiter processing unit 26A2 is a value obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2. Since it is 0 MPa or more, it is larger than the input value (0 MPa) input from the limiter processing unit 26B2.
  • the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the discharge amount required to make the discharge pressure of the hydraulic pump 12 coincide with the target discharge pressure ((P1-1) MPa)
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current Imax from the limiter processing unit 26B2, the opening amount is minimized and the set pressure PS on the secondary side (boom cylinder 4a side) is set to the command current Imax. To a pressure (0 MPa) corresponding to.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting the predetermined value 1 MPa from the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2, and the discharge amount is set to the discharge pressure.
  • the flow rate is determined by the pressure ((P1-1) MPa).
  • the inflow control unit 19A controls the pressure on the secondary side (swing motor 3a side) to be the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2, and via the direction control valve 16A. It can be made to act on the turning motor 3a.
  • the turning drive pressure Py calculated by the PID control unit 26A1 is large, the pressure exceeding the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2 is swung by being limited by the pressure limiting unit 25A2. Since it does not act on the motor 3a, the driving force of the turning motor 3a can be suppressed and the turning body 3 can be turned. Thereby, high force controllability of the swing body 3 is obtained with respect to the operation input of the left operation lever 15A while ensuring speed controllability within the range of the upper limit pressure P1 of the swing drive pressure set by the pressure limiting unit 25A2. be able to. Therefore, the operator can obtain an operation feeling when the driving force of the turning motor 3a is controlled, and can perform work while grasping the load applied to the turning operation of the turning body 3 with the operation feeling of the left operation lever 15A. Can do.
  • the turning drive pressure Py calculated by the PID control unit 26A1 becomes equal to or lower than the upper limit pressure P1 of the turning drive pressure set by the pressure restriction unit 25A2, the pressure restriction unit 25A2 Since the restriction is not applied, the turning drive pressure Py calculated by the PID control unit 26A1 can be applied to the turning motor 3a similarly to the operation when the full lever operation of the left operation lever 15A is performed.
  • the speed controllability of the body 3 can be further improved.
  • the pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the inflow control unit 19A is smaller than the set pressure P1 on the secondary side (swing motor 3a side) by a predetermined value 1 MPa.
  • the pressure loss between the primary side and the secondary side of the electromagnetic proportional pressure reducing valve 19A1 can be suppressed to a necessary minimum. Thereby, even when the half lever operation of the left operation lever 15A is performed, the pressure loss generated in the inflow control unit 19A can be reduced, so that the energy efficiency in the hydraulic circuit can be increased.
  • the electromagnetic proportional pressure reducing valve 19B1 is closed to control the set pressure PS on the secondary side (boom cylinder 4a side) to a pressure (0 MPa) corresponding to the command current Imax, that is, the switching position is shifted to the E position. Even if the hydraulic oil is discharged from the pump 12 to the boom cylinder 4a, the hydraulic oil is blocked by the electromagnetic proportional pressure reducing valve 19B1. Furthermore, since the directional control valve 19B maintains the neutral position (the B position shown in FIG. 2), the discharge pressure of the hydraulic pump 12 does not act on the boom cylinder 4a, and the boom 4A maintains the stopped state.
  • control operation of the controller 20 when the half lever operation of the left operation lever 15A is performed and the half lever operation of the right operation lever 15B is performed in the combined operation will be described.
  • control operations of the target speed calculation unit 25A1, the pressure limiting unit 25A2, and the target drive pressure calculation unit 26A in the controller 20 are the same as when the above-described half lever operation of the left operation lever 15A is performed, and overlapping descriptions are given. Is omitted.
  • the operator seated on the driving seat in the cab 7 operates the right operation lever 15B halfway forward or rearward, thereby pilot pressure oil discharged from the pilot pump according to the operation amount of the right operation lever 15B. Is depressurized. Since the pilot pressure of the pilot pressure oil acts on the direction control valve 16B on the boom cylinder 4a side, the switching position of the direction control valve 16B is changed from the neutral position (position B shown in FIG. 2) to the left position (shown in FIG. 2). The position control valve 16B is opened according to the amount of operation of the right operation lever 15B by switching to the A position) or the right position (C position shown in FIG. 2).
  • the speed sensor 18 ⁇ / b> A detects the speed of the boom cylinder 4 a and outputs a detection signal to the controller 20.
  • the discharge pressure sensor 17 detects the discharge pressure of the hydraulic pump 12 and outputs a detection signal to the controller 20.
  • the target speed calculation unit 25B1 of the controller 20 performs the operation amount X2 (0 ⁇ X2 ⁇ ) detected by the operation amount sensor 15B1 with respect to the functional relationship of the target speed table 25b1.
  • the pressure limiting unit 25B2 of the controller 20 applies the operation amount X2 detected by the operation amount sensor 15B1 to the functional relationship of the upper limit pressure table 25b2, thereby setting the upper limit pressure PB of the boom drive pressure to the minimum value PBmin.
  • the target drive pressure calculation unit 26B receives the detection signal from the speed sensor 18B, the calculation result from the target speed calculation unit 25B1, and the setting result from the pressure limiting unit 25B2, the PID control unit 26B1 of the target drive pressure calculation unit 26B By performing PID control on the speed of the boom cylinder 4a detected by the sensor 18B and the target boom speed V2 calculated by the target speed calculation unit 25B1, the speed deviation is eliminated, that is, the speed of the boom cylinder 4a is set to the target boom. A boom driving pressure Pz required to match the speed V2 is obtained.
  • the inertia load with respect to the turning operation of the boom 4A is relatively large, and the pressure in the hydraulic circuit is limited by the relief valve 21 or the like.
  • the set pressure of the relief valve 21 is set to PrL (P2 ⁇ PrL) in the same manner as the above-described PID control unit 26A1 that is larger than the pressure P2 in the upper limit pressure table 25b2, the boom calculated by the PID control unit 26B1 is used.
  • the driving pressure is PrL as described above.
  • the PID control unit 26B1 obtains PrL as the boom drive pressure Pz and outputs the calculation result to the limiter processing unit 26B2 of the target drive pressure calculation unit 26B.
  • the limiter processing unit 26B2 compares the boom driving pressure PrL calculated by the PID control unit 26B1 with the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2. At this time, as described above, the boom drive pressure PrL calculated by the PID control unit 26B1 is larger than the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 (P2 ⁇ PrL), so the PID control unit 26B1. The calculated boom drive pressure PrL is limited by the pressure limiting unit 25B2.
  • the maximum target discharge pressure selection unit 30A of the target discharge amount calculation unit 30 inputs the calculation results from the limiter processing units 26A2 and 26B2, the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and The input value ((P2-1) MPa) input from the limiter processing unit 26B2 is compared.
  • the maximum target discharge pressure selection unit 30A selects the input value ((P1-1) MPa) input from the limiter processing unit 26A2 and obtains it as the target discharge pressure of the hydraulic pump 12, and calculates the calculation result as a target discharge amount calculation. To the PID control unit 30B of the unit 30.
  • the PID control unit 30B inputs the calculation result from the maximum target discharge pressure selection unit 30A, the discharge pressure of the hydraulic pump 12 detected by the discharge pressure sensor 17 and the hydraulic pump 12 calculated by the maximum target discharge pressure selection unit 30A.
  • the calculation result is output to the target discharge amount correction unit 30C of the target discharge amount calculation unit 30.
  • the target discharge amount correction unit 30C When the target discharge amount correction unit 30C receives the calculation result from the PID control unit 30B, the target discharge amount correction unit 30C divides the discharge amount calculated by the PID control unit 30B by the rotation number of the engine 11 detected by the engine rotation number detection unit 11A. Thus, the target discharge amount is obtained, and the calculation result is output to the tilt amount adjustment unit 12A.
  • the tilt amount adjustment unit 12A adjusts the tilt amount of the hydraulic pump 12, and the discharge amount of the hydraulic pump 12 is corrected by the target discharge amount correction unit 30C. The target discharge amount is controlled.
  • the electromagnetic proportional pressure reducing valve 19A1 of the inflow control unit 19A receives the command current I1 from the limiter processing unit 26A2, the opening amount is adjusted and the set pressure PS on the secondary side (swing motor 3a side) is set to the command current I1. Is controlled so as to be the upper limit pressure P1 of the turning drive pressure set by the pressure limiting unit 25A2.
  • the electromagnetic proportional pressure reducing valve 19B1 of the inflow control unit 19B receives the command current I2 from the limiter processing unit 26B2, the opening amount is adjusted and the set pressure PS on the secondary side (the boom cylinder 4a side) is set to the command current I2. Is controlled so as to become the upper limit pressure P2 of the boom driving pressure set by the pressure limiting unit 25B2.
  • the discharge pressure of the hydraulic pump 12 becomes a pressure ((P1-1) MPa) obtained by subtracting a predetermined value 1 MPa from the upper limit pressure P1 of the swing drive pressure set by the pressure limiter 25A2, and the discharge amount is the swing speed.
  • the flow rate is determined by the discharge pressure ((P1-1) MPa) with respect to the motor 3a and the boom cylinder 4a. Accordingly, it is possible to obtain the same operation and effect as the above-described half lever operation of the left operation lever 15A.
  • the electromagnetic proportional pressure reducing valve 19B1 controls the set pressure PS on the secondary side (boom cylinder 4a side) to the upper limit pressure P2 ( ⁇ P1) of the turning drive pressure set by the pressure limiting unit 25B2,
  • the pressure ((P1-1) MPa) on the primary side (hydraulic pump 12 side) of the control unit 19A becomes larger than the set pressure P2 on the secondary side (boom cylinder 4a side), and the operation discharged from the hydraulic pump 12
  • the oil is adjusted to a flow rate corresponding to the set pressure P2 by the electromagnetic proportional pressure reducing valve 19B1.
  • the upper limit pressure P2 of the boom drive pressure set by the pressure limiting unit 25B2 can be applied to the boom cylinder 4a via the direction control valve 16B.
  • the boom 4A can be rotated while suppressing the driving force of the boom cylinder 4a.
  • high force controllability of the boom 4A can be obtained with respect to the operation input of the right operation lever 15B, while ensuring speed controllability within the range of the boom drive pressure upper limit pressure P2 set by the pressure limiter 25B2.
  • Can do Therefore, the operator can obtain an operation feeling when the driving force of the boom cylinder 4a is controlled, and can perform an operation while grasping the load applied to the rotation operation of the boom 4A with the operation feeling of the right operation lever 15B. Can do.
  • the pressure limiting unit 25B2 Since there is no restriction, the boom drive pressure Pz calculated by the PID control unit 26B1 can be applied to the boom cylinder 4a in the same manner as the operation when the full lever operation of the left operation lever 15A is performed. The speed controllability of 4A can be further improved.
  • the force controllability can be sufficiently improved while ensuring the above. Thereby, stable operation of the swing motor 3a and the boom cylinder 4a can be realized, and a smooth operation feeling can be obtained. Therefore, the operation performance of the operation levers 15A and 15B can be improved, and the working efficiency of the hydraulic excavator 1 can be improved. Can do.
  • the closer the operation of the operation levers 15A and 15B is to the full lever operation the more excellent acceleration performance can be exerted on the swing body 3 and the boom 4A by the speed controllability obtained.
  • the speed intended by the operator can be easily obtained.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are used as the pressure control valves of the inflow control units 19A and 19B, the flow rate of the hydraulic oil flowing into the swing motor 3a and the boom cylinder 4a is controlled. Since the control can be easily executed by the electromagnetic proportional pressure reducing valves 19A1 and 19B1, the hydraulic circuit is not complicated, and the hydraulic circuit can be efficiently manufactured. Thereby, the burden of the operator in the manufacturing process of a hydraulic circuit can be reduced, and manufacturing efficiency can be improved.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 control the secondary side (swing motor 3a side, boom cylinder 4a side) set pressure PS in accordance with the input command current I, thereby controlling the secondary side (swinging). Since the pressure on the motor 3a side and the boom cylinder 4a side) is adjusted to be equal to or lower than the set pressure PS, the hydraulic oil can be accurately guided from the hydraulic pump 12 to the swing motor 3a and the boom cylinder 4a.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are arranged on the secondary side (the swing motor 3a side and the boom cylinder 4a side) when the magnitude of the command current I is equal to or greater than a predetermined current value IA.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are open, so that the operator operates the operation levers 15A and 15B.
  • the driving pressure of the swing motor 3a and the boom cylinder 4a can be ensured, and the swing motor 3a and the boom cylinder 4a can be operated reliably, and the high reliability of the hydraulic excavator 1 can be ensured.
  • the discharge pressure of the hydraulic pump 12 is lowered by a predetermined value, so that the one with the highest load on the inflow control units 19A and 19B can supply the hydraulic oil to the actuator at the maximum opening. Therefore, the pressure loss can be minimized and energy saving can be achieved.
  • the target discharge amount correction unit 30C of the target discharge amount calculation unit 30 divides and corrects the discharge amount input from the PID control unit 30B by the engine speed detected by the engine speed detection unit 11A. Thus, even if the rotational speed of the engine 11 fluctuates greatly, the influence can be suppressed, so that the discharge amount of the hydraulic pump 12 can be controlled stably.
  • FIG. 7 is a diagram showing a configuration of a controller provided in the second embodiment of the present invention
  • FIG. 8 is a function of a target speed table related to the turning motor corrected by the relation correcting unit provided in the second embodiment of the present invention
  • FIG. 9 is a diagram for explaining the relationship
  • FIG. 9 is a diagram for explaining the functional relationship of the target speed table related to the boom cylinder corrected by the relationship correction unit provided in the second embodiment of the present invention.
  • the functional relationship of the target speed table 25a1 is determined by the target drive pressure calculator 26A.
  • a relationship correction unit 35A that corrects the calculated target turning drive pressure according to the target boom drive pressure;
  • a relationship correction unit 35B that corrects the functional relationship of the target speed table 25b1 according to the target boom drive pressure calculated by the target drive pressure calculation unit 26B; It has.
  • the basic configuration of the second embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
  • the relationship correction unit 35A inputs the target turning drive pressure calculated by the target drive pressure calculation unit 26A, for example, and the larger the target turning drive pressure, the more the target In the functional relationship of the speed table 25a1, correction is performed to reduce the absolute value of the gradient of the target turning speed VR with respect to the operation amount XL. Then, the target speed calculation unit 25A1 calculates the target turning speed VR by applying the operation amount XL detected by the operation amount sensor 15A1 to the functional relationship of the target speed table 25a1 corrected by the relationship correction unit 35A. I have to.
  • the relationship correction unit 35B inputs, for example, the target boom drive pressure calculated by the target drive pressure calculation unit 26B, and the target speed table 25b1 increases as the target boom drive pressure increases. In such a functional relationship, correction is performed to reduce the absolute value of the inclination of the target boom speed VB with respect to the operation amount XR. Then, the target speed calculation unit 25B1 calculates the target boom speed VB by applying the operation amount XR detected by the operation amount sensor 15B1 to the functional relationship of the target speed table 25b1 corrected by the relationship correction unit 35B. I have to.
  • the relationship correction unit 35A determines the functional relationship of the target speed table 25a1 as the target drive pressure calculation unit.
  • the correction is made according to the target turning speed calculated by 26A
  • the relationship correction unit 35B corrects the functional relationship of the target speed table 25b1 according to the target boom speed calculated by the target drive pressure calculation unit 26B, thereby speed control.
  • force controllability can be adjusted easily. For example, speed control, such as excavation of heavy rocks, or swivel lateral movement operation that presses the side surface of the bucket 4C against the groove side surface using swiveling in order to solidify so that the sediment on the groove side surface does not collapse during groove excavation.
  • the discharge amount of the hydraulic pump 12 can be suppressed, the invalid flow rate discharged from the relief valve 21 is suppressed, Energy saving can be improved.
  • FIG. 10 is a diagram for explaining an inflow control unit provided in the third embodiment of the present invention.
  • FIG. 10A is a diagram showing a configuration of an electromagnetic proportional throttle valve constituting the inflow control unit, and FIG. The figure which shows the characteristic of an electromagnetic proportional throttle valve,
  • FIG. 11 is a figure which shows the structure of the controller with which 3rd Embodiment of this invention was equipped.
  • the third embodiment of the present invention differs from the first embodiment described above in the first embodiment in that each inflow control unit 19A, 19B determines the pressure of hydraulic fluid that passes through as shown in FIG. 6 (a). While the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are included as pressure control valves to be controlled, in the third embodiment, instead of the electromagnetic proportional pressure reducing valves 19A1 and 19B1, for example, as shown in FIG. It is that electromagnetic proportional throttle valves 19A2 and 19B2 are included as control valves.
  • the basic configuration of the third embodiment of the present invention is the same as that of the first embodiment, and the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 includes, for example, a primary side (hydraulic pump 12 side) and a secondary side (swing motor 3a side, boom cylinder 4a) as in the first embodiment.
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 has an opening area A that is a maximum value Amax when the magnitude of the command current I is less than a predetermined current value IB, and the magnitude of the command current I.
  • the opening area A is inversely proportional to the magnitude of the command current I, and when the magnitude of the command current I is the maximum value Imax, the opening amount is set so that the opening area A becomes 0A. Is adjusted to control the pressure on the secondary side (swing motor 3a side, boom cylinder 4a side).
  • each of the electromagnetic proportional throttle valves 19A2 and 19B2 has a primary side (hydraulic pump 12 side) and a secondary side (side of the hydraulic pump 12) by the elastic force of the springs 19a1 and 19b1.
  • a predetermined current value IB when the swing motor 3a side and the boom cylinder 4a side) are kept in the switching position (the F position shown in FIG. 10A)
  • the springs 19a1 and 19b1 Switching position G position shown in FIG. 10 (a) in which the main body moves against the elastic force and the primary side (hydraulic pump 12 side) and the secondary side (swing motor 3a side, boom cylinder 4a side) are cut off. ).
  • the controller 20 is calculated by the target discharge pressure and target drive pressure calculator 26A calculated by the maximum target discharge pressure selector 30A of the target discharge amount calculator 30 as shown in FIG.
  • the differential pressure calculation unit 27A that calculates the differential pressure with the target turning drive pressure, the target discharge pressure calculated by the maximum target discharge pressure selection unit 30A, and the target boom drive pressure calculated by the target drive pressure calculation unit 26B And a differential pressure calculation unit 27B that calculates the difference.
  • the controller 20 calculates an opening area A of the electromagnetic proportional throttle valve 19A2 based on the differential pressure calculated by the differential pressure calculator 27A and the target turning speed calculated by the target speed calculator 25A1.
  • the flow rate through each of the electromagnetic proportional throttle valves 19A2 and 19B2 is Q
  • the opening area is A
  • the primary side hydroaulic pump 12 side
  • the secondary side tilt motor 3a side, boom cylinder 4a side
  • the differential pressure is ⁇ P
  • the hydraulic fluid density is ⁇
  • the flow coefficient is C
  • the flow rate Q is the product of the target turning speed calculated by the target speed calculating unit 25A1 and the motor capacity that is the specification of the turning motor 3a, and the primary side (hydraulic pump 12 side) and the secondary side (turning motor 3a).
  • the effective differential pressure ⁇ P is calculated from the differential pressure calculated by the differential pressure calculation unit 27A, and the density ⁇ and the flow coefficient C of the hydraulic oil are respectively predetermined constants. Therefore, the opening area calculation unit 28A Calculates the opening area A of the electromagnetic proportional throttle valve 19A2 using the differential pressure calculated by the differential pressure calculation unit 27A, the target turning speed calculated by the target speed calculation unit 25A1, and the above equation (2). I have to.
  • the flow rate Q is the product of the target boom speed calculated by the target speed calculator 25B1 and the pressure receiving area of the boom cylinder 4a, and the primary side (hydraulic pump 12 side) and secondary side (boom cylinder 4a side).
  • the effective differential pressure ⁇ P is obtained from the differential pressure calculated by the differential pressure calculation unit 27B, and the hydraulic fluid density ⁇ and the flow coefficient C are respectively predetermined constants.
  • the opening area A of the electromagnetic proportional throttle valve 19B2 is calculated using the differential pressure calculated by the differential pressure calculation unit 27B, the target boom speed calculated by the target speed calculation unit 25B1, and the above equation (2). Yes.
  • the effective differential pressure ⁇ P becomes a negative value by a predetermined value of 1 MPa.
  • the opening area calculation units 28A and 28B use an electromagnetic proportional throttle. An operation is performed on the valves 19A2 and 19B2 so as to shift the switching position to the F position.
  • the same operational effects as those of the first embodiment described above can be obtained, and electromagnetic proportional throttle valves 19A2 and 19B2 can be used as pressure control valves of the inflow control units 19A and 19B. Since the hydraulic circuit can be miniaturized, the manufacturing cost can be reduced. Thereby, high productivity can be realized.
  • the hydraulic excavator 1 includes the hydraulic pump 12 and the four hydraulic actuators of the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a.
  • the present invention is not limited to this case.
  • the hydraulic actuator includes other than the swing motor 3a, the boom cylinder 4a, the arm cylinder 4b, and the bucket cylinder 4a. But it ’s okay.
  • the target drive pressure calculation unit 26A outputs a value lower than the calculated target turning drive pressure by a predetermined value 1 MPa to the target discharge amount calculation unit 30 as a calculation result
  • the target drive The case where the pressure calculation unit 26B outputs a value lower than the calculated target boom drive pressure by the predetermined value 1 MPa as the calculation result to the target discharge amount calculation unit 30 has been described. Is preferably close to 0 MPa from the viewpoint of the accuracy of control of the hydraulic actuators 3a and 4a. However, in consideration of control variations caused by the accuracy of the pressure control of the hydraulic pump 12 and the control of the inflow control units 19A and 19B, etc. May be set.
  • the target drive pressure may be output to the target discharge amount calculation unit 30 as it is without providing a predetermined value.
  • the driving pressure is the same value.
  • each functional relationship between the target speed table 25a1 of the target speed calculation unit 25A1 and the upper limit pressure table 25a2 of the pressure limiting unit 25A2 is the performance required for the swing operation of the swing body 3.
  • the functional relationship between the target speed table 25b1 of the target speed calculation unit 25B1 and the upper limit pressure table 25b2 of the pressure limiting unit 25B2 takes into consideration the performance required for the pivoting operation of the boom 4A.
  • the functional relationship between the target speed table 25a1 and the upper limit pressure table 25a2 is set in consideration of the balance between the turning operation of the swing body 3 and the other operation parts 4A to 4C.
  • the target speed table 25b1 and the upper limit pressure table Each functional relationship of 25b2 may be set in consideration of the operation balance between the rotation operation of the boom 4A and the other operation parts 3a, 4B, 4C.
  • the cab 7 of the excavator 1 has a work mode setting unit for setting work modes such as a power mode for performing heavy load work and an economy mode for performing light load work, and includes target speed tables 25a1 and 25b1 and upper limit pressure tables.
  • a plurality of functional relationships 25a2 and 25b2 may be set according to the work mode, and may be switched in conjunction with the work mode set by the work mode setting unit.
  • the target speed calculation unit 25A1 is configured such that, for example, as the target turning drive pressure calculated by the target drive pressure calculation unit 26A increases, the target speed with respect to the operation amount XL in the functional relationship of the target speed table 25a1.
  • the target speed calculation unit 25B1 performs correction in the functional relationship of the target speed table 25b1 as the target boom driving pressure calculated by the target driving pressure calculation unit 26B increases.
  • the present invention sets a decrease amount that decreases the absolute value of the inclination of the target turning speed VR with respect to the operation amount XL in the functional relationship of the target speed table 25a1, and sets the target boom with respect to the operation amount XR in the functional relationship of the target speed table 25b1.
  • the operator can freely change the degree of correction of each function relationship of the target speed tables 25a1 and 25b1 by the reduction amount setting unit, so that the operator's operation feeling with respect to the operation levers 15A and 15B can be adjusted, and the operation performance can be improved. It can be improved further.
  • the present invention may include a switching unit that enables or disables correction of each function relationship of the target speed tables 25a1 and 25b1 by the relationship correction unit of the target speed calculation units 25A1 and 25B1. Thereby, the operator can invalidate each function relationship of the target speed tables 25a1 and 25b1 by this switching unit and fix the setting, so that high convenience can be ensured.
  • the electromagnetic proportional pressure reducing valves 19A1 and 19B1 are configured to have a characteristic in which the set pressure PS is inversely proportional to the command current I.
  • the present invention is not limited to this.
  • a valve structure in which the D position and the E position of the electromagnetic proportional pressure reducing valves 19A1 and 19B1 shown in FIG. 6A are exchanged is used, and as the command current I increases, the opening amount increases and the set pressure PS increases. It is good also as a structure.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

L'invention porte sur un dispositif de commande hydraulique pour une machine de travail, avec lequel dispositif une aptitude de commande d'énergie peut être améliorée de façon adéquate tout en assurant l'aptitude de commande de vitesse d'un actionneur hydraulique vis-à-vis d'une entrée d'actionnement à partir d'un dispositif d'actionnement. La présente invention comporte : des unités de calcul de pression d'entraînement cible (26A, 26B), qui calculent des valeurs cibles pour la pression d'entraînement d'actionneurs hydrauliques (3a, 4a) sur la base de la vitesse détectée par des unités de détection de vitesse (18A, 18B) et de valeurs cibles calculées par des unités de calcul de vitesse cible (25A1, 25B1) ; et une unité de calcul de quantité de refoulement cible (30), qui calcule une valeur cible pour la quantité de refoulement d'une pompe hydraulique (12) en fonction de la pression de refoulement détectée par un capteur de pression de refoulement (17) et des valeurs cibles calculées par les unités de calcul de pression d'entraînement cible (26A, 26B). Des unités de commande d'écoulement d'entrée (19A, 19B) commandent la pression d'huile d'actionnement fournie aux actionneurs hydrauliques (3a, 4a) en fonction des valeurs cibles calculées par les unités de calcul de pression d'entraînement cible (26A, 26B), et un dispositif de commande (20) commande la quantité de refoulement de la pompe hydraulique (12) de façon à obtenir la valeur cible calculée par l'unité de calcul de quantité de refoulement cible (30).
PCT/JP2014/071575 2013-08-22 2014-08-18 Dispositif de commande hydraulique pour machine de travail Ceased WO2015025818A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-172509 2013-08-22
JP2013172509A JP5918728B2 (ja) 2013-08-22 2013-08-22 作業機械の油圧制御装置

Publications (1)

Publication Number Publication Date
WO2015025818A1 true WO2015025818A1 (fr) 2015-02-26

Family

ID=52483593

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/071575 Ceased WO2015025818A1 (fr) 2013-08-22 2014-08-18 Dispositif de commande hydraulique pour machine de travail

Country Status (2)

Country Link
JP (1) JP5918728B2 (fr)
WO (1) WO2015025818A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210107765A (ko) * 2019-02-15 2021-09-01 히다찌 겐끼 가부시키가이샤 건설 기계
WO2023182010A1 (fr) 2022-03-22 2023-09-28 日立建機株式会社 Engin de chantier
CN119855992A (zh) * 2022-09-29 2025-04-18 日立建机株式会社 作业机械

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6585401B2 (ja) * 2015-07-09 2019-10-02 日立建機株式会社 作業機械の制御装置
JP6915436B2 (ja) * 2017-08-04 2021-08-04 コベルコ建機株式会社 旋回式油圧作業機械
WO2020065739A1 (fr) * 2018-09-25 2020-04-02 日立建機株式会社 Machine de travail
WO2024043303A1 (fr) * 2022-08-26 2024-02-29 コベルコ建機株式会社 Dispositif de commande et procédé de commande
JP7710420B2 (ja) * 2022-09-30 2025-07-18 日立建機株式会社 作業機械

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09189302A (ja) * 1995-11-06 1997-07-22 Kobe Steel Ltd 油圧アクチュエータの速度制御装置
JP2000027803A (ja) * 1998-07-08 2000-01-25 Uchida Hydraulics Co Ltd クローズドセンター型電磁比例方向制御弁を使用したブリードオフ制御方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09189302A (ja) * 1995-11-06 1997-07-22 Kobe Steel Ltd 油圧アクチュエータの速度制御装置
JP2000027803A (ja) * 1998-07-08 2000-01-25 Uchida Hydraulics Co Ltd クローズドセンター型電磁比例方向制御弁を使用したブリードオフ制御方法

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210107765A (ko) * 2019-02-15 2021-09-01 히다찌 겐끼 가부시키가이샤 건설 기계
US20210332563A1 (en) * 2019-02-15 2021-10-28 Hitachi Construction Machinery Co., Ltd. Construction machine
EP3926177A4 (fr) * 2019-02-15 2022-11-16 Hitachi Construction Machinery Co., Ltd. Engin de chantier
KR102562508B1 (ko) 2019-02-15 2023-08-03 히다찌 겐끼 가부시키가이샤 건설 기계
US11920325B2 (en) * 2019-02-15 2024-03-05 Hitachi Construction Machinery Co., Ltd. Construction machine
WO2023182010A1 (fr) 2022-03-22 2023-09-28 日立建機株式会社 Engin de chantier
KR20240145016A (ko) 2022-03-22 2024-10-04 히다치 겡키 가부시키 가이샤 작업 기계
CN119855992A (zh) * 2022-09-29 2025-04-18 日立建机株式会社 作业机械

Also Published As

Publication number Publication date
JP5918728B2 (ja) 2016-05-18
JP2015040604A (ja) 2015-03-02

Similar Documents

Publication Publication Date Title
JP5918728B2 (ja) 作業機械の油圧制御装置
JP4794468B2 (ja) 建設機械のポンプ制御装置
JP5984165B2 (ja) 作業機械の油圧制御装置
JP6474718B2 (ja) 建設機械の油圧制御装置
JP6793849B2 (ja) 建設機械の油圧駆動装置
JP6852145B2 (ja) ショベル
CN111133204A (zh) 工程机械
WO2016056334A1 (fr) Appareil de commande hydraulique pour engin de chantier
WO2015151776A1 (fr) Dispositif de commande de pression d'huile pour un engin de travail
JP6605316B2 (ja) 作業機械の駆動装置
CN110431274B (zh) 工程机械的液压驱动装置
WO2003001067A1 (fr) Unite hydraulique d'entrainement d'un engin et procede associe
JP6565614B2 (ja) 旋回式油圧作業機械
JP6585401B2 (ja) 作業機械の制御装置
WO2021200024A1 (fr) Engin de chantier
JP7001574B2 (ja) 建設機械
JP5639855B2 (ja) 油圧駆動装置および油圧駆動装置を備えた作業機械
JP5985268B2 (ja) 建設機械用油圧システム
JP6591370B2 (ja) 建設機械の油圧制御装置
JP7053731B2 (ja) 作業機械
JP5755865B2 (ja) 油圧駆動装置および油圧駆動装置を備えた作業機械
JP6989548B2 (ja) 建設機械
JP6118705B2 (ja) 建設機械の旋回制御装置
WO2022102391A1 (fr) Engin de chantier
JP6964059B2 (ja) 建設機械

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14838702

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14838702

Country of ref document: EP

Kind code of ref document: A1