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WO2017122836A1 - Hydraulic system for construction equipment - Google Patents

Hydraulic system for construction equipment Download PDF

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Publication number
WO2017122836A1
WO2017122836A1 PCT/KR2016/000256 KR2016000256W WO2017122836A1 WO 2017122836 A1 WO2017122836 A1 WO 2017122836A1 KR 2016000256 W KR2016000256 W KR 2016000256W WO 2017122836 A1 WO2017122836 A1 WO 2017122836A1
Authority
WO
WIPO (PCT)
Prior art keywords
spool
hydraulic
hydraulic pump
port
poppet
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/KR2016/000256
Other languages
French (fr)
Korean (ko)
Inventor
전만석
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.)
Volvo Construction Equipment AB
Original Assignee
Volvo Construction Equipment AB
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 Volvo Construction Equipment AB filed Critical Volvo Construction Equipment AB
Priority to PCT/KR2016/000256 priority Critical patent/WO2017122836A1/en
Publication of WO2017122836A1 publication Critical patent/WO2017122836A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D29/00—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto
    • F02D29/04—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto peculiar to engines driving pumps
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors

Definitions

  • the present invention relates to a hydraulic system for construction machinery, and more particularly, in the case of operating an optional device selectively mounted on a construction machine, for example, an excavator, in addition to a single operation of the option device as well as a combination operation with the attachment. It relates to a hydraulic system for construction machinery that can adjust the flow rate of the working oil supplied.
  • construction machines such as excavators
  • optional devices such as breakers, hammers, shears, and the like.
  • This option device is operated by the hydraulic oil discharged from the hydraulic pump supplied.
  • a flow rate control valve is installed in the flow path between the option device and the hydraulic pump to control the flow rate of the hydraulic oil discharged from the hydraulic pump and supplied to the option device.
  • the conventional flow control valve is designed to constantly supply the hydraulic fluid discharged from the hydraulic pump to the optional device regardless of the magnitude of the load generated in the optional device.
  • the flow rate of the hydraulic oil supplied to the option apparatus is excessively increased than the set flow rate.
  • the flow rate of the excessively supplied hydraulic oil is stabilized with time.
  • the conventional flow control valve is designed to control only the independent operation of the option device, and thus has a problem such that the operation speed of the option device is lowered when combined with the attachment.
  • the present invention has been made to solve the problems of the prior art as described above, the object of the present invention when operating an optional device that is selectively mounted on a construction machine, such as an excavator, the operation of the optional device as well as attachments To provide a hydraulic system for construction machinery that can control the flow rate of the hydraulic fluid supplied to the optional device even when combined with.
  • the hydraulic pump and the optional device and the hydraulic pump and the attachment is installed in the flow path, one side and the other side is provided with a first port and a second port, respectively, the first applied to the first port 1 the flow path between the hydraulic pump and the option device when switching by the pilot signal pressure, the flow path between the hydraulic pump and the option device when switching by the second pilot signal pressure applied to the second port and the A first spool for simultaneously connecting a flow path between the hydraulic pump and the attachment;
  • a poppet installed to open and close a flow path connecting the hydraulic pump and the first spool, and controlling a flow rate of the working oil supplied from the hydraulic pump to the option device when the first spool is switched;
  • a second spool installed in a flow path connecting the first spool and the option device, and controlling a hydraulic oil supplied to the option device through the first spool during switching; And it is connected to the first spool and the poppet, it is repeatedly switched to one side or the other side according to the magnitude of the pressing force repeatedly applied to one end
  • the pressing force applied to one side end of the third spool may be a value obtained by multiplying the cross-sectional area of the one end pressure receiving unit by the hydraulic oil pressure in the flow passage communicating with the one end.
  • the pressing force applied to the other end of the third spool may be a value obtained by multiplying the cross-sectional area of the other end pressure receiving portion by the hydraulic oil pressure in the flow passage communicating with the other end and adding the elastic force of the valve spring for elastically supporting the other end.
  • a shim having a through hole formed at the inlet side of the first orifice and communicating with the first orifice, and a check valve formed in the first orifice and having a second orifice penetrated at the center thereof.
  • it may further include a piston connected to the poppet.
  • the piston may further include a third orifice which is formed in the piston and controls hydraulic fluid discharged from the hydraulic pump and supplied to the back pressure chamber of the poppet when the third spool is switched.
  • It may further include a fourth orifice installed in a flow path connecting between the third spool and the back pressure chamber of the piston, and for controlling the hydraulic oil supplied from the hydraulic pump to the back pressure chamber of the piston when the third spool is switched.
  • the inlet side is in communication with the flow path between the first spool and the poppet is installed in the flow path is connected to the outlet side to the third spool, and discharged from the hydraulic pump to control the operating oil for switching the third spool It may further include a fifth orifice.
  • the second spool includes a third port and a fourth port provided at one side and the other side, and enables the first operation of the option device when switching by the third pilot signal pressure applied to the third port, When switching by the fourth pilot signal pressure applied to the fourth port, the second operation of the option device may be enabled.
  • the apparatus may further include a first proportional control valve connected to the first port and a second proportional control valve connected to the second port.
  • the first pilot signal pressure is applied to the first port via the first proportional control valve
  • the second pilot signal pressure is applied to the second port via the second proportional control valve.
  • the flow rate of the hydraulic oil supplied to the option device can be constantly adjusted not only in the single operation of the option device but also in the combined operation with the attachment.
  • FIG. 1 is a cross-sectional view showing a flow control valve in a hydraulic system for construction machinery according to an embodiment of the present invention.
  • FIG. 2 is a hydraulic circuit diagram of a hydraulic system for a construction machine according to an embodiment of the present invention.
  • Figure 3 is a cross-sectional view of the poppet of the hydraulic system for construction machinery according to an embodiment of the present invention.
  • the hydraulic system for a construction machine is an optional device such as a breaker, hammer, shear, etc., which is selectively mounted on a construction machine such as an excavator through hydraulic control ( 24) Hydraulic system to control the operation.
  • a construction machine such as an excavator through hydraulic control ( 24) Hydraulic system to control the operation.
  • the hydraulic system for a construction machine according to an embodiment of the present invention, the hydraulic fluid supplied to the option device 24 at the time of combined operation with the attachment of the excavator consisting of the boom, the arm, the bucket as well as the sole operation of the option device 24 Hydraulic system that can control the flow rate.
  • the hydraulic system for a construction machine is formed including a first spool 15, poppet 14, the second spool 25 and the third spool (3).
  • the first spool 15 is discharged from the hydraulic pump 26 to operate the option device 24 and to supply the hydraulic oil to the hydraulic cylinder 37 for attachment for operating the attachment device. It is a spool that controls the movement and flow of hydraulic oil. To this end, the first spool 15 is installed in the flow path connecting the hydraulic pump 26 and the option device 24 and the hydraulic pump 26 and the attachment, more specifically the hydraulic cylinder 37 for attachment. One side of the first spool 15 is provided with a first port a to which the first pilot signal pressure is applied. In this case, the first pilot signal pressure may be applied to the first port a via the first proportional control valve 41.
  • a second port b to which the second pilot signal pressure is applied is provided on the other side of the first spool 15.
  • the second pilot signal pressure may be applied to the second port b via the second proportional control valve 42.
  • the hydraulic oil discharged from the hydraulic pump 26 is supplied to the option device 24, and some of the hydraulic oil discharged from the hydraulic pump 26 is joined to the flow path 32 And joins to the flow path of the hydraulic system for operating the attachment hydraulic cylinder 37 through.
  • the poppet 14 is installed to open and close the flow path 20 connecting the hydraulic pump 26 and the first spool 15.
  • the poppet 14 controls the flow rate of the hydraulic oil supplied from the hydraulic pump 26 to the option device 24 at the time of switching the first spool 15.
  • Hydraulic system for a construction machine further includes a piston 13 connected to the poppet 14, the piston 13 is elastically supported by the elastic member 12.
  • the hydraulic system for a construction machine piston 13 and poppet 14 by the hydraulic oil discharged from the hydraulic pump 26 by switching the third spool (3).
  • it may include a shim (14c) and a check valve (14b) acting as a control means for controlling the flow rate of the working oil passing through the first orifice (14a) of the poppet (14).
  • the shim 14c and the check valve 14b are supplied to the option device 24 from the back pressure chamber 17 of the poppet 14 by the third spool 3 switching in the initial control section of the operation of the option device 24. Prevents the flow of hydraulic oil from increasing above the set flow rate.
  • the shim 14c is seated on the inlet side of the first orifice 14a of the poppet 14.
  • the seam 14c is formed with a through hole 14e in communication with the first orifice 14a.
  • the check valve 14b is built in the first orifice 14a.
  • a second orifice 14d is formed below the check valve 14b (drawing reference).
  • the hydraulic system for construction machinery according to an embodiment of the present invention, the third orifice 13a, the fourth orifice 30a and the fifth orifice 30b to control the hydraulic oil discharged from the hydraulic pump 26.
  • the third orifice 13a is formed in the piston 13.
  • the third orifice 13a discharges from the hydraulic pump 26 when the third spool 3 is switched to control the hydraulic oil supplied to the back pressure chamber 17 of the poppet 14.
  • the fourth orifice 30a is provided in a flow path 23 connecting the third spool 3 and the back pressure chamber 29 of the piston 13.
  • the fourth orifice 30a discharges from the hydraulic pump 26 when the third spool 3 is switched to control the hydraulic oil supplied to the back pressure chamber 29 of the piston 13.
  • the fifth orifice 30b is provided in the flow path 16 through which the inlet side communicates with the flow path between the first spool 15 and the poppet 14 and the outlet side communicates with the third spool 3.
  • the fifth orifice 30b discharges from the hydraulic pump 26 to control the hydraulic oil for switching the third spool 3.
  • the second spool 25 is provided in a flow path connecting the first spool 15 and the option device 24.
  • the second spool 25 controls the hydraulic oil supplied to the option device 24 through the first spool 15 at the time of switching.
  • One side of the second spool 25 according to the embodiment of the present invention is provided with a third port c to which a third pilot signal pressure is applied for the first operation of the option device 24.
  • the first operation of the option device 20 may be an upward movement or a change of direction in the first direction.
  • the second spool 25 When the third pilot signal pressure for the first operation of the option device 24 is applied to the third port c, the second spool 25 is switched in the left direction (reference to the drawing), and from the hydraulic pump 26 In addition to connecting the flow path between the first spool 15 and the option device 24 so that the discharged hydraulic oil can move to the option device 24 via the first spool 15, the hydraulic oil from the option device 24 is connected. Is connected to the flow path between them so that it can be returned to the hydraulic tank (36). At this time, in order for the hydraulic oil discharged from the hydraulic pump 26 to move to the option device 24 via the first spool 15, the first spool 15 may also be driven by the first pilot signal pressure or the second pilot signal pressure. It must be switched.
  • the other side of the second spool 25 is provided with a fourth port d to which the fourth pilot signal pressure is applied for the second operation of the option device 24.
  • the second operation of the option device 25 may be a downward direction or a change of direction in a second direction opposite to the first direction.
  • the fourth pilot signal pressure for the second operation of the option device 25 is applied to the fourth port d, the second spool 25 is switched in the right direction (reference to the drawing), and the hydraulic pump 26
  • the hydraulic fluid discharged from the connecting device is connected to the hydraulic device by connecting the flow path therebetween so as to be movable to the option device 24 via the first spool 15.
  • the flow path between them is connected.
  • the flow path for the hydraulic oil moving to the option device 24 and the hydraulic oil return to the hydraulic tank 36 are flow paths that are opened when the second spool 25 is switched for the first operation of the option device 24. Is reversed.
  • the third spool 3 is connected with the first spool 15 and the poppet 14. At this time, the third spool 3 is repeatedly switched to one side or the other side according to the magnitude of the pressing force repeatedly applied to the left end (based on the drawing) and the right end.
  • the third spool 3 controls the hydraulic oil supplied from the hydraulic pump 26 to the poppet 14 side at the time of switching.
  • the pressing force applied to the left end of the third spool 3 is defined as a value obtained by multiplying the cross-sectional area of the left pressure receiving part by the hydraulic oil pressure in the flow path 16 in communication with the left end, and the third spool 3
  • the pressing force applied to the right end of the c) is defined as the value obtained by multiplying the cross-sectional area of the right end hydraulic part by the hydraulic oil pressure in the flow path 18 in communication with the right end and the elastic force of the valve spring 5 elastically supporting the right end. This will be described in more detail below.
  • the hydraulic oil discharged from the hydraulic pump 26 includes a flow path 20 in one direction connecting the hydraulic pump 26 and the first spool 15, and the flow path 20. It is bisected and supplied to the flow path 20a branched from the other direction from the side. At this time, the hydraulic oil supplied to the flow passage 20 in one direction is also supplied to the pilot flow passage 19 connected thereto.
  • the poppet 14 is pushed up in the upward direction (see FIG. 1) by the hydraulic oil supplied to the flow path 20 in one direction.
  • the check valve 14b embedded in the first orifice 14a of the poppet 14 is moved to the upper seam 14c position.
  • the hydraulic oil supplied to the mixing chamber 17 of the poppet 14 is moved to the chamber 21 through the second orifice 14d of the check valve 14b embedded in the poppet 14. For this reason, the poppet 14 is moved upward and comes into contact with the piston 13. At this time, the elastic member 12 is compressed. Accordingly, the hydraulic oil supplied to the flow path 20 in one direction is moved to the chamber 21. At this time, the hydraulic fluid moved to the chamber 21 is blocked by the first spool 15 that is maintained in a neutral state and is not supplied to the option device 24. In addition, the hydraulic oil of the flow path 20a branched from the flow path 20 in one direction to the other direction is returned to the hydraulic tank 36 via the second spool 25.
  • variable notch portion formed on the outer circumferential surface of the first spool 15 27, pressure loss starts to occur between the chamber 21 and the option port 22.
  • the pressure loss also increases as the flow rate of the hydraulic fluid moving from the chamber 21 to the option port 22 increases.
  • the pressure of the hydraulic oil raised by the switching of the first spool 15 passes through the fifth orifice 30b of the flow path P1 16 in communication with the chamber 21, and thus the left side of the third spool 3. Supplied to the stage. For this reason, the 3rd spool 3 is switched to a right direction.
  • the pressure receiving section cross-sectional area of the third spool 3 is A1
  • the force for switching the third spool 3 to the right direction is A1 ⁇ P1.
  • the pressure of the hydraulic oil at the option port 22 is supplied to the right end of the third spool 3 through the flow path P2 18 communicated with it.
  • the 3rd spool 3 is switched to a left direction.
  • the pressure receiving section cross-sectional area of the third spool 3 is A2
  • the force for switching the third spool 3 to the left is A2 ⁇ P2 + F1.
  • F1 is the elastic force of the valve spring 5.
  • the condition for maintaining the initial state in which the third spool 3 is not switched is A1 ⁇ P1 ⁇ A2 ⁇ P2 + F1
  • the condition for switching the third spool 3 in the right direction is A1 ⁇ P1> A2. It becomes * P2 + F1.
  • the hydraulic oil supplied to the pilot oil passage 19 communicating with the oil passage 20 in one direction connecting the hydraulic pump 26 and the first spool 15 may be After passing through the three spools 3 and the flow path 23 connecting the back pressure chamber 29 of the piston 13, they are supplied to the back pressure chamber 29 of the piston 13. Through this, the piston 13 moves in the downward direction (see FIG. 1). In this case, the poppet 14 also moves downward at the same time.
  • variable notch portion formed on the outer circumferential surface of the first spool 15 (The pressure loss starts to occur between the chamber 21 and the option port 22 by 35). In this case, the pressure loss also increases as the flow rate of the hydraulic fluid moving from the chamber 21 to the option port 22 increases.
  • the pressure of the hydraulic oil raised by the switching of the first spool 15 passes through the fifth orifice 30b of the flow path P1 16 in communication with the chamber 21, and thus the left side of the third spool 3. Supplied to the stage. For this reason, the 3rd spool 3 is switched to a right direction.
  • the pressure receiving section cross-sectional area of the third spool 3 is A1
  • the force for switching the third spool 3 to the right direction is A1 ⁇ P1.
  • the pressure of the hydraulic oil at the option port 22 is supplied to the right end of the third spool 3 through the flow path P2 18 communicated with it.
  • the 3rd spool 3 is switched to a left direction.
  • the pressure receiving section cross-sectional area of the third spool 3 is A2
  • the force for switching the third spool 3 to the left is A2 ⁇ P2 + F1.
  • F1 is the elastic force of the valve spring 5.
  • the condition for maintaining the initial state in which the third spool 3 is not switched is A1 ⁇ P1 ⁇ A2 ⁇ P2 + F1
  • the condition for switching the third spool 3 in the right direction is A1 ⁇ P1> A2. It becomes * P2 + F1.
  • the second pilot signal pressure is applied to the second port b of the first spool 15 and the first spool 15 is switched in the left direction (reference to the drawing), it is moved to the chamber 21.
  • the hydraulic oil is supplied to the option device 24 through the option port 22, and some of the hydraulic oil discharged from the hydraulic pump 26 and supplied to the flow path 20 in one direction is upwardly loaded with the rod check poppet 38. While waiting in the chamber 31 in the upward direction, it passes through the notch part 33 and the joining flow path 32 and is supplied to the attachment hydraulic cylinder 37 side.
  • the hydraulic system for construction machinery contributes to the improvement of the operation speed of the attachment not only during the independent operation of the option device 24 but also during the combined operation with the attachment.
  • the flow rate of the hydraulic oil supplied can be adjusted constantly.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

The present invention provides a hydraulic system for construction equipment, the system comprising: a first spool installed on a fluid channel that connects a hydraulic pump and an optional device and connects the hydraulic pump and an attachment, the first spool having first and second ports provided on opposite sides thereof, respectively, wherein the first spool connects the fluid channel between the hydraulic pump and the optional device when switched by a first pilot signal pressure applied to the first port, and simultaneously connects the fluid channel between the hydraulic pump and the optional device and the fluid channel between the hydraulic pump and the attachment when switched by a second pilot signal pressure applied to the second port; a poppet installed to open/close a fluid channel connecting the hydraulic pump and the first spool, wherein the poppet controls the amount of hydraulic oil supplied from the hydraulic pump to the optional device when the first spool is switched; a second spool installed on a fluid channel connecting the first spool and the optional device, wherein the second spool controls a hydraulic oil supplied to the optional device through the first spool when switched; and a third spool connected with the first spool and the poppet, wherein the third spool is repeatedly switched to one side or an opposite side according to the magnitude of pressure repeatedly applied to opposite ends thereof, and controls a hydraulic oil supplied from the hydraulic pump to the poppet when switched.

Description

건설기계용 유압시스템Hydraulic System for Construction Machinery

본 발명은 건설기계용 유압시스템에 관한 것으로서 더욱 상세하게는 건설기계, 예컨대, 굴삭기에 선택적으로 장착되는 옵션장치를 작동시키는 경우, 옵션장치의 단독 동작 뿐만 아니라 어태치먼트와의 복합 동작 시에도 옵션장치에 공급되는 작동유의 유량을 조절할 수 있는 건설기계용 유압시스템에 관한 것이다.The present invention relates to a hydraulic system for construction machinery, and more particularly, in the case of operating an optional device selectively mounted on a construction machine, for example, an excavator, in addition to a single operation of the option device as well as a combination operation with the attachment. It relates to a hydraulic system for construction machinery that can adjust the flow rate of the working oil supplied.

일반적으로, 건설기계, 예컨대, 굴삭기에는 브레이커(breaker), 햄머(hammer), 전단기(shear) 등과 같은 옵션장치가 선택적으로 장착된다. 이러한 옵션장치는 유압펌프로부터 토출되어 공급되는 작동유에 의해 작동하게 된다. 이때, 옵션장치와 유압펌프 사이의 유로에는 유량제어밸브가 설치되어, 유압펌프로부터 토출되어 옵션장치로 공급되는 작동유의 유량을 제어한다. 여기서, 종래의 유량제어밸브는 옵션장치에 발생되는 부하의 크기에 관계없이 유압펌프로부터 토출되는 작동유를 옵션장치에 일정하게 공급하도록 설계되어 있다. 이때, 옵션장치의 초기 동작구간에서는 옵션장치에 공급되는 작동유의 유량이 설정된 유량보다 과다하게 증가되는데, 이와 같이, 과다 공급된 작동유의 유량은 시간이 경과함에 따라 안정화된다. 이로 인해, 옵션장치의 초기 동작구간에서는 옵션장치의 이상동작이 초래되어 안정성이 저하되는 문제가 있었다. 또한, 종래의 유량제어밸브는 옵션장치의 단독 동작만을 제어하도록 설계되어 있어, 어태치먼트와의 복합 동작 시 옵션장치의 동작 속도가 저하되는 등의 문제점을 가지고 있다.In general, construction machines, such as excavators, are optionally equipped with optional devices such as breakers, hammers, shears, and the like. This option device is operated by the hydraulic oil discharged from the hydraulic pump supplied. At this time, a flow rate control valve is installed in the flow path between the option device and the hydraulic pump to control the flow rate of the hydraulic oil discharged from the hydraulic pump and supplied to the option device. Here, the conventional flow control valve is designed to constantly supply the hydraulic fluid discharged from the hydraulic pump to the optional device regardless of the magnitude of the load generated in the optional device. At this time, in the initial operation section of the option apparatus, the flow rate of the hydraulic oil supplied to the option apparatus is excessively increased than the set flow rate. Thus, the flow rate of the excessively supplied hydraulic oil is stabilized with time. As a result, abnormal operation of the option device is caused in the initial operation section of the option device, resulting in a problem that the stability is lowered. In addition, the conventional flow control valve is designed to control only the independent operation of the option device, and thus has a problem such that the operation speed of the option device is lowered when combined with the attachment.

본 발명은 상술한 바와 같은 종래기술의 문제점을 해결하기 위해 안출된 것으로서, 본 발명의 목적은 건설기계, 예컨대, 굴삭기에 선택적으로 장착되는 옵션장치를 작동시키는 경우, 옵션장치의 단독 동작 뿐만 아니라 어태치먼트와의 복합 동작 시에도 옵션장치에 공급되는 작동유의 유량을 조절할 수 있는 건설기계용 유압시스템을 제공하는 것이다.The present invention has been made to solve the problems of the prior art as described above, the object of the present invention when operating an optional device that is selectively mounted on a construction machine, such as an excavator, the operation of the optional device as well as attachments To provide a hydraulic system for construction machinery that can control the flow rate of the hydraulic fluid supplied to the optional device even when combined with.

이를 위해, 본 발명은, 유압펌프와 옵션장치 및 상기 유압펌프와 어태치먼트를 연결하는 유로에 설치되고, 일측 및 타측에는 제1 포트 및 제2 포트가 각각 제공되며, 상기 제1 포트에 인가되는 제1 파일럿 신호압에 의해 절환 시 상기 유압펌프와 상기 옵션장치 사이의 유로를 연결시키고, 상기 제2 포트에 인가되는 제2 파일럿 신호압에 의해 절환 시 상기 유압펌프와 상기 옵션장치 사이의 유로 및 상기 유압펌프와 상기 어태치먼트 사이의 유로를 동시에 연결시키는 제1 스풀; 상기 유압펌프와 상기 제1 스풀을 연결하는 유로를 개폐할 수 있도록 설치되고, 상기 제1 스풀 절환 시 상기 유압펌프로부터 상기 옵션장치에 공급되는 작동유의 유량을 제어하는 포펫; 상기 제1 스풀과 상기 옵션장치를 연결하는 유로에 설치되고, 절환 시 상기 제1 스풀을 통과하여 상기 옵션장치에 공급되는 작동유를 제어하는 제2 스풀; 및 상기 제1 스풀 및 상기 포펫과 연결되고, 일측단 및 타측단에 반복적으로 가해지는 가압력의 크기에 따라 일측 또는 타측으로 반복 절환되며, 절환 시 상기 유압펌프로부터 상기 포펫 측으로 공급되는 작동유를 제어하는 제3 스풀을 포함하는 건설기계용 유압시스템을 제공한다.To this end, the present invention, the hydraulic pump and the optional device and the hydraulic pump and the attachment is installed in the flow path, one side and the other side is provided with a first port and a second port, respectively, the first applied to the first port 1 the flow path between the hydraulic pump and the option device when switching by the pilot signal pressure, the flow path between the hydraulic pump and the option device when switching by the second pilot signal pressure applied to the second port and the A first spool for simultaneously connecting a flow path between the hydraulic pump and the attachment; A poppet installed to open and close a flow path connecting the hydraulic pump and the first spool, and controlling a flow rate of the working oil supplied from the hydraulic pump to the option device when the first spool is switched; A second spool installed in a flow path connecting the first spool and the option device, and controlling a hydraulic oil supplied to the option device through the first spool during switching; And it is connected to the first spool and the poppet, it is repeatedly switched to one side or the other side according to the magnitude of the pressing force repeatedly applied to one end and the other end, when switching to control the hydraulic oil supplied from the hydraulic pump to the poppet side It provides a hydraulic system for construction machinery comprising a third spool.

여기서, 상기 제3 스풀의 일측단에 가해지는 가압력은 상기 일측단 수압부의 단면적과 상기 일측단과 연통된 유로 내의 작동유 압력을 곱한 값일 수 있다.Here, the pressing force applied to one side end of the third spool may be a value obtained by multiplying the cross-sectional area of the one end pressure receiving unit by the hydraulic oil pressure in the flow passage communicating with the one end.

또한, 상기 제3 스풀의 타측단에 가해지는 가압력은 상기 타측단 수압부의 단면적과 상기 타측단과 연통된 유로 내의 작동유 압력을 곱한 값에 상기 타측단을 탄성 지지하는 밸브스프링의 탄성력을 더한 값일 수 있다.In addition, the pressing force applied to the other end of the third spool may be a value obtained by multiplying the cross-sectional area of the other end pressure receiving portion by the hydraulic oil pressure in the flow passage communicating with the other end and adding the elastic force of the valve spring for elastically supporting the other end. .

상기 포펫의 제1 오리피스 입구측에 안착되고 상기 제1 오리피스와 연통되는 관통공이 형성된 심(shim) 및 상기 제1 오리피스에 내설되고 중앙에 제2 오리피스가 관통 형성된 체크밸브를 더 포함할 수 있다.And a shim having a through hole formed at the inlet side of the first orifice and communicating with the first orifice, and a check valve formed in the first orifice and having a second orifice penetrated at the center thereof.

또한, 상기 포펫과 연결되는 피스톤을 더 포함할 수 있다.In addition, it may further include a piston connected to the poppet.

상기 피스톤에 형성되고, 상기 제3 스풀 절환 시 상기 유압펌프로부터 토출되어 상기 포펫의 배압실에 공급되는 작동유를 제어하는 제3 오리피스를 더 포함할 수 있다.The piston may further include a third orifice which is formed in the piston and controls hydraulic fluid discharged from the hydraulic pump and supplied to the back pressure chamber of the poppet when the third spool is switched.

상기 제3 스풀과 상기 피스톤의 배압실 사이를 연결하는 유로에 설치되고, 상기 제3 스풀 절환 시 상기 유압펌프로부터 상기 피스톤의 배압실에 공급되는 작동유를 제어하는 제4 오리피스를 더 포함할 수 있다.It may further include a fourth orifice installed in a flow path connecting between the third spool and the back pressure chamber of the piston, and for controlling the hydraulic oil supplied from the hydraulic pump to the back pressure chamber of the piston when the third spool is switched. .

또한, 상기 제1 스풀과 상기 포펫 사이의 유로에 입구측이 연통되고 상기 제3 스풀에 출구측이 연통되는 유로에 설치되고, 상기 유압펌프로부터 토출되어 상기 제3 스풀을 절환시키는 작동유를 제어하는 제5 오리피스를 더 포함할 수 있다.In addition, the inlet side is in communication with the flow path between the first spool and the poppet is installed in the flow path is connected to the outlet side to the third spool, and discharged from the hydraulic pump to control the operating oil for switching the third spool It may further include a fifth orifice.

상기 제2 스풀은 일측 및 타측에 제공되는 제3 포트 및 제4 포트를 포함하고, 상기 제3 포트에 인가되는 제3 파일럿 신호압에 의해 절환 시 상기 옵션장치의 제1 동작을 가능하게 하고, 상기 제4 포트에 인가되는 제4 파일럿 신호압에 의해 절환 시 상기 옵션장치의 제2 동작을 가능하게 할 수 있다.The second spool includes a third port and a fourth port provided at one side and the other side, and enables the first operation of the option device when switching by the third pilot signal pressure applied to the third port, When switching by the fourth pilot signal pressure applied to the fourth port, the second operation of the option device may be enabled.

또한, 상기 제1 포트에 연결되어 있는 제1 비례제어밸브 및 상기 제2 포트에 연결되어 있는 제2 비례제어밸브를 더 포함할 수 있다.The apparatus may further include a first proportional control valve connected to the first port and a second proportional control valve connected to the second port.

이때, 상기 제1 파일럿 신호압은 상기 제1 비례제어밸브를 경유하여, 상기 제1 포트에 인가되고, 상기 제2 파일럿 신호압은 상기 제2 비례제어밸브를 경유하여, 상기 제2 포트에 인가될 수 있다.In this case, the first pilot signal pressure is applied to the first port via the first proportional control valve, and the second pilot signal pressure is applied to the second port via the second proportional control valve. Can be.

본 발명에 따르면, 옵션장치의 단독 동작 뿐만 아니라 어태치먼트와의 복합 동작 시에도 옵션장치에 공급되는 작동유의 유량을 일정하게 조절할 수 있다.According to the present invention, the flow rate of the hydraulic oil supplied to the option device can be constantly adjusted not only in the single operation of the option device but also in the combined operation with the attachment.

또한, 본 발명에 따르면, 옵션장치의 부하 크기에 관계없이 옵션장치에 일정한 유량을 공급함으로써, 옵션장치의 작동속도를 일정하게 제어할 수 있고, 이를 통해, 조작성을 향상시킬 수 있다.In addition, according to the present invention, by supplying a constant flow rate to the option device irrespective of the load size of the option device, it is possible to constantly control the operating speed of the option device, thereby improving the operability.

또한, 본 발명에 따르면, 여러 종류의 옵션장치에 요구되는 작동유의 유량을 각각 조절할 수 있어, 작업능률을 향상시킬 수 있다.In addition, according to the present invention, it is possible to adjust the flow rate of the hydraulic oil required for various types of option devices, respectively, it is possible to improve the work efficiency.

또한, 본 발명에 따르면, 옵션장치의 초기 제어구간에서 작동유의 유량이 과다하게 증가되는 것을 방지할 수 있고, 이를 통해, 옵션장치의 초기 작동 시 안전성을 확보할 수 있다.In addition, according to the present invention, it is possible to prevent excessive increase in the flow rate of the working oil in the initial control section of the option device, thereby ensuring the safety during the initial operation of the option device.

도 1은 본 발명의 실시 예에 따른 건설기계용 유압시스템에서, 유량제어밸브를 나타낸 단면도이다.1 is a cross-sectional view showing a flow control valve in a hydraulic system for construction machinery according to an embodiment of the present invention.

도 2는 본 발명의 실시 예에 따른 건설기계용 유압시스템에 대한 유압 회로도이다.2 is a hydraulic circuit diagram of a hydraulic system for a construction machine according to an embodiment of the present invention.

도 3은 본 발명의 실시 예에 따른 건설기계용 유압시스템의 포펫 단면도이다.Figure 3 is a cross-sectional view of the poppet of the hydraulic system for construction machinery according to an embodiment of the present invention.

이하에서는 첨부된 도면들을 참조하여 본 발명의 실시 예에 따른 건설기계용 유압시스템에 대해 상세히 설명한다.Hereinafter, with reference to the accompanying drawings will be described in detail for the hydraulic system for construction machinery according to an embodiment of the present invention.

아울러, 본 발명을 설명함에 있어서, 관련된 공지 기능 혹은 구성에 대한 구체적인 설명이 본 발명의 요지를 불필요하게 흐릴 수 있다고 판단된 경우 그 상세한 설명은 생략한다.In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

도 1 및 도 2에 도시한 바와 같이, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 유압 제어를 통해, 굴삭기와 같은 건설기계에 선택적으로 장착되는 브레이커, 햄머, 전단기 등과 같은 옵션장치(24)의 동작을 제어하는 유압시스템이다. 또한, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 옵션장치(24)의 단독 동작 뿐만 아니라 붐, 아암, 버켓으로 이루어지는 굴삭기의 어태치먼트와의 복합 동작 시에도 옵션장치(24)에 공급되는 작동유의 유량을 제어할 수 있는 유압시스템이다.1 and 2, the hydraulic system for a construction machine according to an embodiment of the present invention is an optional device such as a breaker, hammer, shear, etc., which is selectively mounted on a construction machine such as an excavator through hydraulic control ( 24) Hydraulic system to control the operation. In addition, the hydraulic system for a construction machine according to an embodiment of the present invention, the hydraulic fluid supplied to the option device 24 at the time of combined operation with the attachment of the excavator consisting of the boom, the arm, the bucket as well as the sole operation of the option device 24 Hydraulic system that can control the flow rate.

이를 위해, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 제1 스풀(15), 포펫(14), 제2 스풀(25) 및 제3 스풀(3)을 포함하여 형성된다.To this end, the hydraulic system for a construction machine according to an embodiment of the present invention is formed including a first spool 15, poppet 14, the second spool 25 and the third spool (3).

제1 스풀(15)은 옵션장치(24)를 동작시킴과 아울러, 어태치먼트 동작 시 이를 동작시키기 위한 어태치먼트용 유압 실린더(37)에 대한 작동유 공급이 이루어질 수 있도록 하기 위해 유압펌프(26)로부터 토출되는 작동유의 이동 및 유량을 제어하는 스풀이다. 이를 위해, 제1 스풀(15)은 유압펌프(26)와 옵션장치(24) 및 유압펌프(26)와 어태치먼트, 보다 상세하게는 어태치먼트용 유압 실린더(37)를 연결하는 유로에 설치된다. 제1 스풀(15)의 일측에는 제1 파일럿 신호압이 인가되는 제1 포트(a)가 제공된다. 이때, 제1 파일럿 신호압은 제1 비례제어밸브(41)를 경유하여, 제1 포트(a)에 인가될 수 있다. 이와 같이, 제1 포트(a)에 인가된 제1 파일럿 신호압에 의해 제1 스풀(15)이 우측 방향(도면기준)으로 절환되면, 유압펌프(26)와 옵션장치(24) 사이의 유로가 연결된다. 제1 파일럿 신호압에 의해 유압펌프(26)와 옵션장치(24) 사이의 유로가 연결됨에 따라, 유압펌프(26)로부터 옵션장치(24)로 작동유의 공급이 가능해지고, 옵션장치(24)로부터 유압탱크(36)로 작동유의 귀환이 가능해진다. 이를 통해, 옵션장치(24)는 동작 가능한 상태가 된다. 이때, 옵션장치(24)의 실질적인 동작은 제1 스풀(15)과 옵션장치(24) 사이에 설치되는 제2 스풀(25)에 의해 제어되는데 이에 대해서는 하기에서 보다 상세히 설명하기로 한다.The first spool 15 is discharged from the hydraulic pump 26 to operate the option device 24 and to supply the hydraulic oil to the hydraulic cylinder 37 for attachment for operating the attachment device. It is a spool that controls the movement and flow of hydraulic oil. To this end, the first spool 15 is installed in the flow path connecting the hydraulic pump 26 and the option device 24 and the hydraulic pump 26 and the attachment, more specifically the hydraulic cylinder 37 for attachment. One side of the first spool 15 is provided with a first port a to which the first pilot signal pressure is applied. In this case, the first pilot signal pressure may be applied to the first port a via the first proportional control valve 41. In this way, when the first spool 15 is switched in the right direction (drawing reference) by the first pilot signal pressure applied to the first port a, a flow path between the hydraulic pump 26 and the option device 24 is provided. Is connected. As the flow path between the hydraulic pump 26 and the option device 24 is connected by the first pilot signal pressure, the hydraulic oil can be supplied from the hydraulic pump 26 to the option device 24, and the option device 24 is provided. From this, the hydraulic oil can be returned to the hydraulic tank 36. In this way, the option device 24 is operable. At this time, the substantial operation of the option device 24 is controlled by the second spool 25 provided between the first spool 15 and the option device 24, which will be described in more detail below.

또한, 제1 스풀(15)의 타측에는 제2 파일럿 신호압이 인가되는 제2 포트(b)가 제공된다. 이때, 제2 파일럿 신호압은 제2 비례제어밸브(42)를 경유하여, 제2 포트(b)에 인가될 수 있다. 이와 같이, 제2 포트(b)에 인가된 제2 파일럿 신호압에 의해 제1 스풀(15)이 좌측 방향(도면기준)으로 절환되면, 유압펌프(26)와 옵션장치(24) 사이의 유로 및 유압펌프(26)와 어태치먼트용 유압 실린더(37) 사이의 유로가 동시에 연결된다. 제2 파일럿 신호압에 의해 이들 유로가 동시에 연결됨에 따라, 유압펌프(26)로부터 토출된 작동유는 옵션장치(24)에 공급되고, 유압펌프(26)로부터 토출된 작동유 중 일부는 합류유로(32)를 통해 어태치먼트용 유압 실린더(37)를 동작시키는 유압시스템의 유로에 합류된다.In addition, a second port b to which the second pilot signal pressure is applied is provided on the other side of the first spool 15. In this case, the second pilot signal pressure may be applied to the second port b via the second proportional control valve 42. In this way, when the first spool 15 is switched in the left direction (drawing reference) by the second pilot signal pressure applied to the second port b, a flow path between the hydraulic pump 26 and the option device 24 is provided. And a flow path between the hydraulic pump 26 and the attachment hydraulic cylinder 37 at the same time. As these flow paths are simultaneously connected by the second pilot signal pressure, the hydraulic oil discharged from the hydraulic pump 26 is supplied to the option device 24, and some of the hydraulic oil discharged from the hydraulic pump 26 is joined to the flow path 32 And joins to the flow path of the hydraulic system for operating the attachment hydraulic cylinder 37 through.

포펫(14)은 유압펌프(26)와 제1 스풀(15)을 연결하는 유로(20)를 개폐할 수 있도록 설치된다. 이러한 포펫(14)은 제1 스풀(15) 절환 시 유압펌프(26)로부터 옵션장치(24)에 공급되는 작동유의 유량을 제어한다.The poppet 14 is installed to open and close the flow path 20 connecting the hydraulic pump 26 and the first spool 15. The poppet 14 controls the flow rate of the hydraulic oil supplied from the hydraulic pump 26 to the option device 24 at the time of switching the first spool 15.

본 발명의 실시 예에 따른 건설기계용 유압시스템은 이러한 포펫(14)과 연결되는 피스톤(13)을 더 포함하는데, 이러한 피스톤(13)은 탄성부재(12)에 의해 탄성 지지된다.Hydraulic system for a construction machine according to an embodiment of the present invention further includes a piston 13 connected to the poppet 14, the piston 13 is elastically supported by the elastic member 12.

한편, 도 3에 도시한 바와 같이, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 제3 스풀(3) 절환으로 유압펌프(26)로부터 토출되는 작동유에 의해 피스톤(13) 및 포펫(14)이 가압되는 경우, 포펫(14)의 제1 오리피스(14a)를 통과하는 작동유의 유량을 제어하는 제어수단으로 작용하는 심(shim)(14c) 및 체크밸브(14b)를 포함할 수 있다. 심(14c)과 체크밸브(14b)는 옵션장치(24)의 동작 초기 제어구간에서, 제3 스풀(3) 절환으로 포펫(14)의 배압실(17)에서 옵션장치(24)에 공급되는 작동유의 유량이 설정된 유량 이상으로 증가되는 것을 방지한다. 여기서, 심(14c)은 포펫(14)의 제1 오리피스(14a)의 입구측에 안착된다. 이러한 심(14c)에는 제1 오리피스(14a)와 연통되는 관통공(14e)이 형성되어 있다. 또한, 체크밸브(14b)는 제1 오리피스(14a)에 내설된다. 이러한 체크밸브(14b)의 하측(도면기준)에는 제2 오리피스(14d)가 형성된다.On the other hand, as shown in Figure 3, the hydraulic system for a construction machine according to an embodiment of the present invention piston 13 and poppet 14 by the hydraulic oil discharged from the hydraulic pump 26 by switching the third spool (3). ) Is pressurized, it may include a shim (14c) and a check valve (14b) acting as a control means for controlling the flow rate of the working oil passing through the first orifice (14a) of the poppet (14). The shim 14c and the check valve 14b are supplied to the option device 24 from the back pressure chamber 17 of the poppet 14 by the third spool 3 switching in the initial control section of the operation of the option device 24. Prevents the flow of hydraulic oil from increasing above the set flow rate. Here, the shim 14c is seated on the inlet side of the first orifice 14a of the poppet 14. The seam 14c is formed with a through hole 14e in communication with the first orifice 14a. In addition, the check valve 14b is built in the first orifice 14a. A second orifice 14d is formed below the check valve 14b (drawing reference).

또한, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 유압펌프(26)로부터 토출되는 작동유를 제어하기 위해, 제3 오리피스(13a), 제4 오리피스(30a) 및 제5 오리피스(30b)를 포함한다. 제3 오리피스(13a)는 피스톤(13)에 형성된다. 이러한 제3 오리피스(13a)는 제3 스풀(3) 절환 시 유압펌프(26)로부터 토출되어 포펫(14)의 배압실(17)에 공급되는 작동유를 제어한다. 제4 오리피스(30a)는 제3 스풀(3)과 피스톤(13)의 배압실(29) 사이를 연결하는 유로(23)에 설치된다. 이러한 제4 오리피스(30a)는 제3 스풀(3) 절환 시 유압펌프(26)로부터 토출되어 피스톤(13)의 배압실(29)에 공급되는 작동유를 제어한다. 제5 오리피스(30b)는 제1 스풀(15)과 포펫(14) 사이의 유로에 입구측이 연통되고 제3 스풀(3)에 출구측이 연통되는 유로(16)에 설치된다. 이러한 제5 오리피스(30b)는 유압펌프(26)로부터 토출되어 제3 스풀(3)을 절환시키는 작동유를 제어한다.In addition, the hydraulic system for construction machinery according to an embodiment of the present invention, the third orifice 13a, the fourth orifice 30a and the fifth orifice 30b to control the hydraulic oil discharged from the hydraulic pump 26. Include. The third orifice 13a is formed in the piston 13. The third orifice 13a discharges from the hydraulic pump 26 when the third spool 3 is switched to control the hydraulic oil supplied to the back pressure chamber 17 of the poppet 14. The fourth orifice 30a is provided in a flow path 23 connecting the third spool 3 and the back pressure chamber 29 of the piston 13. The fourth orifice 30a discharges from the hydraulic pump 26 when the third spool 3 is switched to control the hydraulic oil supplied to the back pressure chamber 29 of the piston 13. The fifth orifice 30b is provided in the flow path 16 through which the inlet side communicates with the flow path between the first spool 15 and the poppet 14 and the outlet side communicates with the third spool 3. The fifth orifice 30b discharges from the hydraulic pump 26 to control the hydraulic oil for switching the third spool 3.

제2 스풀(25)은 제1 스풀(15)과 옵션장치(24)를 연결하는 유로에 설치된다. 제2 스풀(25)은 절환 시 제1 스풀(15)을 통과하여 옵션장치(24)에 공급되는 작동유를 제어한다. 본 발명의 실시 예에 따른 제2 스풀(25)의 일측에는 옵션장치(24)의 제1 동작을 위한 제3 파일럿 신호압이 인가되는 제3 포트(c)가 제공된다. 여기서, 옵션장치(20)의 제1 동작은 상승이나 제1 방향으로의 방향 전환일 수 있다. 제3 포트(c)에 옵션장치(24)의 제1 동작을 위한 제3 파일럿 신호압이 인가되면, 제2 스풀(25)은 좌측 방향(도면기준)으로 절환되어, 유압펌프(26)로부터 토출되는 작동유가 제1 스풀(15)을 경유하여 옵션장치(24)로 이동 가능하도록 제1 스풀(15)과 옵션장치(24) 사이의 유로를 연결시킴과 아울러, 옵션장치(24)로부터 작동유가 유압탱크(36)로 귀환 가능하도록 이들 사이의 유로를 연결시킨다. 이때, 유압펌프(26)로부터 토출되는 작동유가 제1 스풀(15)을 경유하여 옵션장치(24)로 이동하기 위해서는 제1 스풀(15) 또한 제1 파일럿 신호압 또는 제2 파일럿 신호압에 의해 절환되어야 한다.The second spool 25 is provided in a flow path connecting the first spool 15 and the option device 24. The second spool 25 controls the hydraulic oil supplied to the option device 24 through the first spool 15 at the time of switching. One side of the second spool 25 according to the embodiment of the present invention is provided with a third port c to which a third pilot signal pressure is applied for the first operation of the option device 24. Here, the first operation of the option device 20 may be an upward movement or a change of direction in the first direction. When the third pilot signal pressure for the first operation of the option device 24 is applied to the third port c, the second spool 25 is switched in the left direction (reference to the drawing), and from the hydraulic pump 26 In addition to connecting the flow path between the first spool 15 and the option device 24 so that the discharged hydraulic oil can move to the option device 24 via the first spool 15, the hydraulic oil from the option device 24 is connected. Is connected to the flow path between them so that it can be returned to the hydraulic tank (36). At this time, in order for the hydraulic oil discharged from the hydraulic pump 26 to move to the option device 24 via the first spool 15, the first spool 15 may also be driven by the first pilot signal pressure or the second pilot signal pressure. It must be switched.

또한, 제2 스풀(25)의 타측에는 옵션장치(24)의 제2 동작을 위한 제4 파일럿 신호압이 인가되는 제4 포트(d)가 제공된다. 여기서, 옵션장치(25)의 제2 동작은 하강이나 제1 방향과 반대되는 제2 방향으로의 방향 전환일 수 있다. 이러한 제4 포트(d)에 옵션장치(25)의 제2 동작을 위한 제4 파일럿 신호압이 인가되면, 제2 스풀(25)은 우측 방향(도면기준)으로 절환되어, 유압펌프(26)로부터 토출되는 작동유가 제1 스풀(15)을 경유하여 옵션장치(24)로 이동 가능하도록 이들 사이의 유로를 연결시킴과 아울러, 옵션장치(24)로부터 작동유가 유압탱크(36)로 귀환 가능하도록 이들 사이의 유로를 연결시킨다. 이때, 작동유가 옵션장치(24)로 이동하는 유로와 작동유가 유압탱크(36)로 귀환하는 유로는 옵션장치(24)의 제1 동작을 위해 제2 스풀(25)의 절환 시 개방되는 유로들과 반전된다.In addition, the other side of the second spool 25 is provided with a fourth port d to which the fourth pilot signal pressure is applied for the second operation of the option device 24. Here, the second operation of the option device 25 may be a downward direction or a change of direction in a second direction opposite to the first direction. When the fourth pilot signal pressure for the second operation of the option device 25 is applied to the fourth port d, the second spool 25 is switched in the right direction (reference to the drawing), and the hydraulic pump 26 The hydraulic fluid discharged from the connecting device is connected to the hydraulic device by connecting the flow path therebetween so as to be movable to the option device 24 via the first spool 15. The flow path between them is connected. At this time, the flow path for the hydraulic oil moving to the option device 24 and the hydraulic oil return to the hydraulic tank 36 are flow paths that are opened when the second spool 25 is switched for the first operation of the option device 24. Is reversed.

제3 스풀(3)은 제1 스풀(15) 및 포펫(14)과 연결된다. 이때, 제3 스풀(3)은 좌측단(도면기준) 및 우측단에 반복적으로 가해지는 가압력의 크기에 따라 일측 또는 타측으로 반복 절환된다. 이러한 제3 스풀(3)은 절환 시 유압펌프(26)로부터 포펫(14) 측으로 공급되는 작동유를 제어한다. 본 발명의 실시 예에서, 제3 스풀(3)의 좌측단에 가해지는 가압력은 좌측단 수압부의 단면적과 좌측단과 연통된 유로(16) 내의 작동유 압력을 곱한 값으로 정의되고, 제3 스풀(3)의 우측단에 가해지는 가압력은 우측단 수압부의 단면적과 우측단과 연통된 유로(18) 내의 작동유 압력을 곱한 값에 우측단을 탄성 지지하는 밸브스프링(5)의 탄성력을 더한 값으로 정의되는데, 이에 대해서는 하기에서 보다 상세히 설명하기로 한다.The third spool 3 is connected with the first spool 15 and the poppet 14. At this time, the third spool 3 is repeatedly switched to one side or the other side according to the magnitude of the pressing force repeatedly applied to the left end (based on the drawing) and the right end. The third spool 3 controls the hydraulic oil supplied from the hydraulic pump 26 to the poppet 14 side at the time of switching. In the embodiment of the present invention, the pressing force applied to the left end of the third spool 3 is defined as a value obtained by multiplying the cross-sectional area of the left pressure receiving part by the hydraulic oil pressure in the flow path 16 in communication with the left end, and the third spool 3 The pressing force applied to the right end of the c) is defined as the value obtained by multiplying the cross-sectional area of the right end hydraulic part by the hydraulic oil pressure in the flow path 18 in communication with the right end and the elastic force of the valve spring 5 elastically supporting the right end. This will be described in more detail below.

이하, 본 발명의 실시 예에 따른 건설기계용 유압시스템의 작동에 대하여 도 1 및 도 2를 참조하여 설명하기로 한다.Hereinafter, the operation of the hydraulic system for a construction machine according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

도 1 및 도 2에 도시한 바와 같이, 유압펌프(26)로부터 토출된 작동유는 유압펌프(26)와 제1 스풀(15)을 연결하는 일측 방향의 유로(20)와, 이 유로(20)로부터 타측 방향으로 분기된 유로(20a)에 양분되어 공급된다. 이때, 일측 방향의 유로(20)에 공급되는 작동유는 이와 연결되어 있는 파일럿 유로(19)에도 공급된다. 일측 방향의 유로(20)에 공급되는 작동유에 의해 포펫(14)은 상측 방향(도 1 기준)으로 밀려 올라간다. 동시에, 포펫(14)의 제1 오리피스(14a)에 내설된 체크밸브(14b)는 상측의 심(14c) 위치까지 이동된다. 또한, 포펫(14)의 배합실(17)에 공급된 작동유는 포펫(14)에 내설된 체크밸브(14b)의 제2 오리피스(14d)를 통과하여 챔버(21)로 이동된다. 이로 인해, 포펫(14)은 상측 방향으로 이동되어, 피스톤(13)에 접촉된다. 이때, 탄성부재(12)는 압축된다. 이에 따라, 일측 방향의 유로(20)에 공급되는 작동유는 챔버(21)로 이동된다. 이때, 챔버(21)에 이동된 작동유는 중립상태로 유지되는 제1 스풀(15)에 의해 차단되어 옵션장치(24)에 공급되지 않는다. 또한, 일측 방향의 유로(20)로부터 타측 방향으로 분기된 유로(20a)의 작동유는 제2 스풀(25)을 경유하여, 유압탱크(36)로 귀환된다.As shown in FIGS. 1 and 2, the hydraulic oil discharged from the hydraulic pump 26 includes a flow path 20 in one direction connecting the hydraulic pump 26 and the first spool 15, and the flow path 20. It is bisected and supplied to the flow path 20a branched from the other direction from the side. At this time, the hydraulic oil supplied to the flow passage 20 in one direction is also supplied to the pilot flow passage 19 connected thereto. The poppet 14 is pushed up in the upward direction (see FIG. 1) by the hydraulic oil supplied to the flow path 20 in one direction. At the same time, the check valve 14b embedded in the first orifice 14a of the poppet 14 is moved to the upper seam 14c position. In addition, the hydraulic oil supplied to the mixing chamber 17 of the poppet 14 is moved to the chamber 21 through the second orifice 14d of the check valve 14b embedded in the poppet 14. For this reason, the poppet 14 is moved upward and comes into contact with the piston 13. At this time, the elastic member 12 is compressed. Accordingly, the hydraulic oil supplied to the flow path 20 in one direction is moved to the chamber 21. At this time, the hydraulic fluid moved to the chamber 21 is blocked by the first spool 15 that is maintained in a neutral state and is not supplied to the option device 24. In addition, the hydraulic oil of the flow path 20a branched from the flow path 20 in one direction to the other direction is returned to the hydraulic tank 36 via the second spool 25.

이 상태에서, 제2 스풀(25)의 제3 포트(c)에 제3 파일럿 신호압이 인가되어, 제2 스풀(25)이 좌측 방향(도면기준)으로 절환되면, 유압펌프(26)로부터 타측 방향으로 분기된 유로(20a)를 따라 이동되는 작동유는 제2 스풀(25)에 의해 차단된다. 이때, 유압펌프(26)로부터 토출되어 일측 방향의 유로(20)에 공급되는 작동유 중 일부는 로드 체크 포펫(38)을 상측 방향으로 밀어 올려 챔버(31)에 대기한다.In this state, when the third pilot signal pressure is applied to the third port c of the second spool 25 and the second spool 25 is switched in the left direction (drawing reference), the hydraulic pump 26 The hydraulic fluid moved along the flow path 20a branched in the other direction is blocked by the second spool 25. At this time, some of the hydraulic oil discharged from the hydraulic pump 26 and supplied to the flow path 20 in one direction pushes the rod check poppet 38 upward and waits in the chamber 31.

이 상태에서, 제1 스풀(15)의 제1 포트(a)에 제1 파일럿 신호압이 인가되어, 제1 스풀(15)이 우측 방향(도면기준)으로 절환되면, 챔버(21)에 이동된 작동유는 옵션포트(22)를 통과하여 옵션장치(24)에 공급되고, 이로 인해, 옵션장치(24)는 동작하게 된다. 이때, 제1 파일럿 신호압에 의해 제1 스풀(15)이 절환되는 경우, 제1 스풀(15)의 움직임 정도 혹은 이동량에 따라 제1 스풀(15)의 외주면에 형성되어 있는 가변 노치부(27)의 단면적이 가변되고, 이를 통해, 제1 스풀(15)을 통과하여 옵션장치(24)에 공급되는 작동유의 유량이 결정된다. 여기서, 이와 같이 유압펌프(26)로부터 토출된 작동유가 제1 스풀(15)을 경유하여 제2 스풀(25) 측으로 흐르기 시작하면, 제1 스풀(15)의 외주면에 형성되어 있는 가변 노치부(27)에 의해 챔버(21)와 옵션포트(22) 사이에 압력 손실이 발생하기 시작한다. 이 경우, 챔버(21)에서 옵션포트(22)로 이동하는 작동유의 유량이 증가되는 만큼 압력 손실 또한 증가된다.In this state, when the first pilot signal pressure is applied to the first port a of the first spool 15 and the first spool 15 is switched in the right direction (drawing reference), it moves to the chamber 21. The supplied hydraulic oil passes through the option port 22 and is supplied to the option device 24, whereby the option device 24 is operated. At this time, when the first spool 15 is switched by the first pilot signal pressure, the variable notch portion 27 formed on the outer circumferential surface of the first spool 15 according to the degree of movement or the amount of movement of the first spool 15. ), The cross-sectional area is varied, and through this, the flow rate of the working oil supplied to the option device 24 through the first spool 15 is determined. Here, when the hydraulic oil discharged from the hydraulic pump 26 begins to flow to the second spool 25 via the first spool 15, the variable notch portion formed on the outer circumferential surface of the first spool 15 ( 27, pressure loss starts to occur between the chamber 21 and the option port 22. In this case, the pressure loss also increases as the flow rate of the hydraulic fluid moving from the chamber 21 to the option port 22 increases.

이때, 제1 스풀(15)의 절환으로 상승되는 작동유의 압력은 챔버(21)와 연통된 유로(P1)(16)의 제5 오리피스(30b)를 통과하여, 제3 스풀(3)의 좌측단에 공급된다. 이로 인해, 제3 스풀(3)은 우측 방향으로 절환된다. 예를 들어, 제3 스풀(3)의 수압부 단면적을 A1이라고 하면, 제3 스풀(3)을 우측 방향으로 절환시키는 힘은 A1×P1이 된다. 그리고 옵션포트(22)에서의 작동유의 압력은 이와 연통된 유로(P2)(18)를 통과하여 제3 스풀(3)의 우측단에 공급된다. 이로 인해, 제3 스풀(3)은 좌측 방향으로 절환된다. 이 경우, 제3 스풀(3)의 수압부 단면적을 A2라고 하면, 제3 스풀(3)을 좌측 방향으로 절환시키는 힘은 A2×P2+F1이 된다. 여기서, F1은 밸브스프링(5)의 탄성력이다.At this time, the pressure of the hydraulic oil raised by the switching of the first spool 15 passes through the fifth orifice 30b of the flow path P1 16 in communication with the chamber 21, and thus the left side of the third spool 3. Supplied to the stage. For this reason, the 3rd spool 3 is switched to a right direction. For example, when the pressure receiving section cross-sectional area of the third spool 3 is A1, the force for switching the third spool 3 to the right direction is A1 × P1. The pressure of the hydraulic oil at the option port 22 is supplied to the right end of the third spool 3 through the flow path P2 18 communicated with it. For this reason, the 3rd spool 3 is switched to a left direction. In this case, when the pressure receiving section cross-sectional area of the third spool 3 is A2, the force for switching the third spool 3 to the left is A2 × P2 + F1. Here, F1 is the elastic force of the valve spring 5.

즉, 제3 스풀(3)을 절환시키지 않는 초기상태로 유지하는 조건은, A1×P1 < A2×P2+F1이고, 제3 스풀(3)을 우측 방향으로 절환시키는 조건은 A1×P1 > A2×P2+F1이 된다.In other words, the condition for maintaining the initial state in which the third spool 3 is not switched is A1 × P1 <A2 × P2 + F1, and the condition for switching the third spool 3 in the right direction is A1 × P1> A2. It becomes * P2 + F1.

제3 스풀(3)이 우측 방향으로 절환되는 경우, 유압펌프(26)와 제1 스풀(15)을 연결하는 일측 방향의 유로(20)와 연통되는 파일럿 유로(19)에 공급된 작동유는 제3 스풀(3)과, 이와 피스톤(13)의 배압실(29)을 연결하는 유로(23)를 차례로 통과한 후 피스톤(13)의 배압실(29)에 공급된다. 이를 통해, 피스톤(13)은 하측 방향(도 1 기준)으로 움직인다. 이 경우, 포펫(14)도 동시에 하측 방향으로 움직인다.When the third spool 3 is switched in the right direction, the hydraulic oil supplied to the pilot oil passage 19 communicating with the oil passage 20 in one direction connecting the hydraulic pump 26 and the first spool 15 may be After passing through the three spools 3 and the flow path 23 connecting the back pressure chamber 29 of the piston 13, they are supplied to the back pressure chamber 29 of the piston 13. Through this, the piston 13 moves in the downward direction (see FIG. 1). In this case, the poppet 14 also moves downward at the same time.

이와 같이, 포펫(14)이 하측 방향으로 움직이면, 유로(20)와 챔버(21) 사이의 유로가 포펫(14)에 의해 차단된다. 이 경우, 챔버(21)와 연통된 유로(P1)(16) 내의 압력이 감소하게 되고, 이와 같이 감소된 압력으로 인해, 제3 스풀(3)을 좌측 방향으로 움직이게 하는 A1×P1 < A2×P2+F1 조건이 성립되어, 제3 스풀(3)이 좌측 방향으로 움직이게 된다.As such, when the poppet 14 moves downward, the flow path between the flow path 20 and the chamber 21 is blocked by the poppet 14. In this case, the pressure in the flow path P1 16 in communication with the chamber 21 is reduced, and A1 x P1 <A2 x which causes the third spool 3 to move to the left due to the reduced pressure. The condition P2 + F1 is established so that the third spool 3 moves to the left.

이와 같이, 제3 스풀(3)이 좌측 방향으로 움직이면, 파일럿 유로(19) 내의 압력이 유로(23) 측으로 공급되는 것이 차단된다. 이로 인해, 포펫(14)이 상측 방향으로 이동됨에 따라, 유압펌프(26)로부터 토출된 작동유가 유로(20), 챔버(21), 유로(P1)(16)을 경유하여 제3 스풀(3)의 좌측단에 공급된다. 즉, 제3 스풀(3)을 우측 방향으로 절환시키는 A1×P1 > A2×P2+F1 조건이 성립되어, 제3 스풀(3)이 우측 방향으로 절환된다.In this way, when the third spool 3 moves in the left direction, the pressure in the pilot flow passage 19 is blocked from being supplied to the flow passage 23 side. Thus, as the poppet 14 is moved upward, the hydraulic oil discharged from the hydraulic pump 26 passes through the flow path 20, the chamber 21, and the flow path P1 16 to the third spool 3. It is supplied to the left end of the That is, the condition A1 x P1> A2 x P2 + F1 for switching the third spool 3 in the right direction is established, and the third spool 3 is switched in the right direction.

상기와 같은 제3 스풀(3)의 반복적인 절환 동작이 이루어짐에 따라, 챔버(21)와 옵션포트(22) 사이에 발생되는 압력 손실이 일정하게 되어, Q=Cd×A×ΔP 공식이 성립된다. 여기서, Q는 유량, Cd는 유량계수, A(스풀 개구면적)는 상수(constant), ΔP(압력 손실로, P1과 P2의 차)는 상수(constant)이다.As the repetitive switching operation of the third spool 3 is performed as described above, the pressure loss generated between the chamber 21 and the option port 22 becomes constant, and the formula Q = Cd × A × ΔP is established. do. Where Q is the flow rate, Cd is the flow coefficient, A (spool opening area) is constant, and ΔP (pressure loss, the difference between P1 and P2) is constant.

반대로, 제1 스풀(15)의 제2 포트(b)에 제2 파일럿 신호압이 인가되어, 제1 스풀(15)이 좌측 방향(도면기준)으로 절환되는 경우, 챔버(21)에 이동된 작동유는 옵션포트(22)를 통과하여 옵션장치(24)에 공급되고, 이로 인해, 옵션장치(24)는 동작하게 된다. 이때, 제2 파일럿 신호압에 의해 제1 스풀(15)이 절환되는 경우, 제1 스풀(15)의 움직임 정도 혹은 이동량에 따라 제1 스풀(15)의 외주면에 형성되어 있는 가변 노치부(27)의 단면적이 가변되고, 이를 통해, 제1 스풀(15)을 통과하여 옵션장치(24)에 공급되는 작동유의 유량이 결정된다. 여기서, 이와 같이 유압펌프(26)로부터 토출된 작동유가 제1 스풀(15)을 경유하여 제2 스풀(25) 측으로 흐르기 시작하면, 제1 스풀(15)의 외주면에 형성되어 있는 가변 노치부(35)에 의해 챔버(21)와 옵션포트(22) 사이에 압력 손실이 발생하기 시작한다. 이 경우, 챔버(21)에서 옵션포트(22)로 이동하는 작동유의 유량이 증가되는 만큼 압력 손실 또한 증가된다.On the contrary, when the second pilot signal pressure is applied to the second port b of the first spool 15 so that the first spool 15 is switched in the left direction (drawing reference), it is moved to the chamber 21. The hydraulic oil is supplied to the option device 24 through the option port 22, whereby the option device 24 is operated. At this time, when the first spool 15 is switched by the second pilot signal pressure, the variable notch portion 27 formed on the outer circumferential surface of the first spool 15 according to the degree of movement or the amount of movement of the first spool 15. ), The cross-sectional area is varied, and through this, the flow rate of the working oil supplied to the option device 24 through the first spool 15 is determined. Here, when the hydraulic oil discharged from the hydraulic pump 26 begins to flow to the second spool 25 via the first spool 15, the variable notch portion formed on the outer circumferential surface of the first spool 15 ( The pressure loss starts to occur between the chamber 21 and the option port 22 by 35). In this case, the pressure loss also increases as the flow rate of the hydraulic fluid moving from the chamber 21 to the option port 22 increases.

이때, 제1 스풀(15)의 절환으로 상승되는 작동유의 압력은 챔버(21)와 연통된 유로(P1)(16)의 제5 오리피스(30b)를 통과하여, 제3 스풀(3)의 좌측단에 공급된다. 이로 인해, 제3 스풀(3)은 우측 방향으로 절환된다. 예를 들어, 제3 스풀(3)의 수압부 단면적을 A1이라고 하면, 제3 스풀(3)을 우측 방향으로 절환시키는 힘은 A1×P1이 된다. 그리고 옵션포트(22)에서의 작동유의 압력은 이와 연통된 유로(P2)(18)를 통과하여 제3 스풀(3)의 우측단에 공급된다. 이로 인해, 제3 스풀(3)은 좌측 방향으로 절환된다. 이 경우, 제3 스풀(3)의 수압부 단면적을 A2라고 하면, 제3 스풀(3)을 좌측 방향으로 절환시키는 힘은 A2×P2+F1이 된다. 여기서, F1은 밸브스프링(5)의 탄성력이다.At this time, the pressure of the hydraulic oil raised by the switching of the first spool 15 passes through the fifth orifice 30b of the flow path P1 16 in communication with the chamber 21, and thus the left side of the third spool 3. Supplied to the stage. For this reason, the 3rd spool 3 is switched to a right direction. For example, when the pressure receiving section cross-sectional area of the third spool 3 is A1, the force for switching the third spool 3 to the right direction is A1 × P1. The pressure of the hydraulic oil at the option port 22 is supplied to the right end of the third spool 3 through the flow path P2 18 communicated with it. For this reason, the 3rd spool 3 is switched to a left direction. In this case, when the pressure receiving section cross-sectional area of the third spool 3 is A2, the force for switching the third spool 3 to the left is A2 × P2 + F1. Here, F1 is the elastic force of the valve spring 5.

즉, 제3 스풀(3)을 절환시키지 않는 초기상태로 유지하는 조건은, A1×P1 < A2×P2+F1이고, 제3 스풀(3)을 우측 방향으로 절환시키는 조건은 A1×P1 > A2×P2+F1이 된다.In other words, the condition for maintaining the initial state in which the third spool 3 is not switched is A1 × P1 <A2 × P2 + F1, and the condition for switching the third spool 3 in the right direction is A1 × P1> A2. It becomes * P2 + F1.

제3 스풀(3)이 좌측 방향으로 절환되는 경우, 파일럿 유로(19) 내의 압력이 유로(23) 측으로 공급되는 것이 차단된다. 이로 인해, 포펫(14)이 상측 방향으로 이동됨에 따라, 유압펌프(26)로부터 토출된 작동유가 유로(20), 챔버(21), 유로(P1)(16)을 경유하여 제3 스풀(3)의 좌측단에 공급된다. 즉, 제3 스풀(3)을 우측 방향으로 절환시키는 A1×P1 > A2×P2+F1 조건이 성립되어, 제3 스풀(3)이 우측 방향으로 절환된다.When the third spool 3 is switched in the left direction, the pressure in the pilot flow passage 19 is blocked from being supplied to the flow passage 23 side. Thus, as the poppet 14 is moved upward, the hydraulic oil discharged from the hydraulic pump 26 passes through the flow path 20, the chamber 21, and the flow path P1 16 to the third spool 3. It is supplied to the left end of the That is, the condition A1 x P1> A2 x P2 + F1 for switching the third spool 3 in the right direction is established, and the third spool 3 is switched in the right direction.

이와 같이, 제3 스풀(3)이 우측 방향으로 움직이면, 유압펌프(26)와 제1 스풀(15)을 연결하는 일측 방향의 유로(20)와 연통되는 파일럿 유로(19)에 공급된 작동유는 제3 스풀(3)과, 이와 피스톤(13)의 배압실(29)을 연결하는 유로(23)를 차례로 통과한 후 피스톤(13)의 배압실(29)에 공급된다. 이를 통해, 피스톤(13)은 하측 방향(도 1 기준)으로 움직인다. 이 경우, 포펫(14)도 동시에 하측 방향으로 움직인다.As such, when the third spool 3 moves in the right direction, the hydraulic oil supplied to the pilot oil passage 19 communicating with the oil passage 20 in one direction connecting the hydraulic pump 26 and the first spool 15 is After passing through the 3rd spool 3 and the flow path 23 which connects this and the back pressure chamber 29 of the piston 13, it is supplied to the back pressure chamber 29 of the piston 13. As shown in FIG. Through this, the piston 13 moves in the downward direction (see FIG. 1). In this case, the poppet 14 also moves downward at the same time.

이와 같이, 포펫(14)이 하측 방향으로 움직이면, 유로(20)과 챔버(21) 사이의 유로가 포펫(14)에 의해 차단된다. 이 경우, 챔버(21)와 연통된 유로(P1)(16) 내의 압력이 감소하게 되고, 이와 같이 감소된 압력으로 인해, 제3 스풀(3)을 좌측 방향으로 움직이게 하는 A1×P1 < A2×P2+F1 조건이 성립되어, 제3 스풀(3)이 좌측 방향으로 움직이게 된다.As such, when the poppet 14 moves downward, the flow path between the flow path 20 and the chamber 21 is blocked by the poppet 14. In this case, the pressure in the flow path P1 16 in communication with the chamber 21 is reduced, and A1 x P1 <A2 x which causes the third spool 3 to move to the left due to the reduced pressure. The condition P2 + F1 is established so that the third spool 3 moves to the left.

상기와 같은 제3 스풀(3)의 반복적인 절환 동작이 이루어짐에 따라, 챔버(21)와 옵션포트(22) 사이에 발생되는 압력 손실이 일정하게 되어, Q=Cd×A×ΔP 공식이 성립된다.As the repetitive switching operation of the third spool 3 is performed as described above, the pressure loss generated between the chamber 21 and the option port 22 becomes constant, and the formula Q = Cd × A × ΔP is established. do.

한편, 제1 스풀(15)의 제2 포트(b)에 제2 파일럿 신호압이 인가되어, 제1 스풀(15)이 좌측 방향(도면기준)으로 절환되는 경우, 챔버(21)에 이동된 작동유가 옵션포트(22)를 통과하여 옵션장치(24)에 공급됨과 아울러, 유압펌프(26)로부터 토출되어 일측 방향의 유로(20)에 공급되는 작동유 중 일부는 로드 체크 포펫(38)을 상측 방향으로 밀어 올려 챔버(31)에 대기하다가 노치부(33) 및 합류유로(32)를 통과하여 어태치먼트용 유압실린더(37) 측으로 공급된다.On the other hand, when the second pilot signal pressure is applied to the second port b of the first spool 15 and the first spool 15 is switched in the left direction (reference to the drawing), it is moved to the chamber 21. The hydraulic oil is supplied to the option device 24 through the option port 22, and some of the hydraulic oil discharged from the hydraulic pump 26 and supplied to the flow path 20 in one direction is upwardly loaded with the rod check poppet 38. While waiting in the chamber 31 in the upward direction, it passes through the notch part 33 and the joining flow path 32 and is supplied to the attachment hydraulic cylinder 37 side.

이와 같이, 본 발명의 실시 예에 따른 건설기계용 유압시스템은 옵션장치(24)의 단독 동작 뿐만 아니라 어태치먼트와의 복합 동작 시에도 어태치먼트의 동작 속도 향상에 기여를 하는 한편, 옵션장치(24)에 공급되는 작동유의 유량을 일정하게 조절할 수 있다.As described above, the hydraulic system for construction machinery according to the embodiment of the present invention contributes to the improvement of the operation speed of the attachment not only during the independent operation of the option device 24 but also during the combined operation with the attachment. The flow rate of the hydraulic oil supplied can be adjusted constantly.

이상과 같이 본 발명은 비록 한정된 실시 예와 도면에 의해 설명되었으나, 본 발명은 상기의 실시 예에 한정되는 것은 아니며, 본 발명이 속하는 분야에서 통상의 지식을 가진 자라면 이러한 기재로부터 다양한 수정 및 변형이 가능하다.As described above, although the present invention has been described with reference to the limited embodiments and the drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

그러므로 본 발명의 범위는 설명된 실시 예에 국한되어 정해져서는 아니 되며, 후술하는 특허청구범위뿐만 아니라 특허청구범위와 균등한 것들에 의해 정해져야 한다.Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (11)

유압펌프와 옵션장치 및 상기 유압펌프와 어태치먼트를 연결하는 유로에 설치되고, 일측 및 타측에는 제1 포트 및 제2 포트가 각각 제공되며, 상기 제1 포트에 인가되는 제1 파일럿 신호압에 의해 절환 시 상기 유압펌프와 상기 옵션장치 사이의 유로를 연결시키고, 상기 제2 포트에 인가되는 제2 파일럿 신호압에 의해 절환 시 상기 유압펌프와 상기 옵션장치 사이의 유로 및 상기 유압펌프와 상기 어태치먼트 사이의 유로를 동시에 연결시키는 제1 스풀;It is installed in the hydraulic pump and the optional device and the flow path connecting the hydraulic pump and the attachment, the first and second ports are provided on one side and the other side, respectively, and switched by the first pilot signal pressure applied to the first port The flow path between the hydraulic pump and the option device, and when switching by the second pilot signal pressure applied to the second port, the flow path between the hydraulic pump and the option device and between the hydraulic pump and the attachment A first spool for simultaneously connecting the flow paths; 상기 유압펌프와 상기 제1 스풀을 연결하는 유로를 개폐할 수 있도록 설치되고, 상기 제1 스풀 절환 시 상기 유압펌프로부터 상기 옵션장치에 공급되는 작동유의 유량을 제어하는 포펫;A poppet installed to open and close a flow path connecting the hydraulic pump and the first spool, and controlling a flow rate of the working oil supplied from the hydraulic pump to the option device when the first spool is switched; 상기 제1 스풀과 상기 옵션장치를 연결하는 유로에 설치되고, 절환 시 상기 제1 스풀을 통과하여 상기 옵션장치에 공급되는 작동유를 제어하는 제2 스풀; 및A second spool installed in a flow path connecting the first spool and the option device, and controlling a hydraulic oil supplied to the option device through the first spool during switching; And 상기 제1 스풀 및 상기 포펫과 연결되고, 일측단 및 타측단에 반복적으로 가해지는 가압력의 크기에 따라 일측 또는 타측으로 반복 절환되며, 절환 시 상기 유압펌프로부터 상기 포펫 측으로 공급되는 작동유를 제어하는 제3 스풀;It is connected to the first spool and the poppet, it is repeatedly switched to one side or the other side according to the magnitude of the pressing force repeatedly applied to one end and the other end, the switching agent for controlling the hydraulic oil supplied from the hydraulic pump to the poppet side 3 spools; 을 포함하는 건설기계용 유압시스템.Hydraulic system for construction machinery comprising a. 제1항에 있어서,The method of claim 1, 상기 제3 스풀의 일측단에 가해지는 가압력은 상기 일측단 수압부의 단면적과 상기 일측단과 연통된 유로 내의 작동유 압력을 곱한 값인 것을 포함하는 건설기계용 유압시스템.And a pressing force applied to one end of the third spool is a value obtained by multiplying a cross-sectional area of the one end pressure receiving part by a hydraulic oil pressure in a flow passage communicating with the one end. 제1항에 있어서,The method of claim 1, 상기 제3 스풀의 타측단에 가해지는 가압력은 상기 타측단 수압부의 단면적과 상기 타측단과 연통된 유로 내의 작동유 압력을 곱한 값에 상기 타측단을 탄성 지지하는 밸브스프링의 탄성력을 더한 값인 것을 포함하는 건설기계용 유압시스템.The pressing force applied to the other end of the third spool is a value including a value obtained by multiplying the cross-sectional area of the other end pressure receiving portion and the hydraulic oil pressure in the flow passage communicating with the other end plus the elastic force of the valve spring for elastically supporting the other end. Hydraulic system for machines. 제1항에 있어서,The method of claim 1, 상기 포펫의 제1 오리피스 입구측에 안착되고 상기 제1 오리피스와 연통되는 관통공이 형성된 심(shim) 및 상기 제1 오리피스에 내설되고 중앙에 제2 오리피스가 관통 형성된 체크밸브를 더 포함하는 건설기계용 유압시스템.And a shim seated at a first orifice inlet side of the poppet and having a through hole communicating with the first orifice, and a check valve built into the first orifice and having a second orifice penetrating through the center thereof. Hydraulic system. 제1항에 있어서,The method of claim 1, 상기 포펫과 연결되는 피스톤을 더 포함하는 건설기계용 유압시스템.Hydraulic system for a construction machine further comprising a piston connected with the poppet. 제5항에 있어서,The method of claim 5, 상기 피스톤에 형성되고, 상기 제3 스풀 절환 시 상기 유압펌프로부터 토출되어 상기 포펫의 배압실에 공급되는 작동유를 제어하는 제3 오리피스를 더 포함하는 건설기계용 유압시스템.And a third orifice formed in the piston and controlling hydraulic fluid discharged from the hydraulic pump and supplied to the back pressure chamber of the poppet when the third spool is switched. 제5항에 있어서,The method of claim 5, 상기 제3 스풀과 상기 피스톤의 배압실 사이를 연결하는 유로에 설치되고, 상기 제3 스풀 절환 시 상기 유압펌프로부터 상기 피스톤의 배압실에 공급되는 작동유를 제어하는 제4 오리피스를 더 포함하는 건설기계용 유압시스템.And a fourth orifice installed in a flow path connecting between the third spool and the back pressure chamber of the piston, and controlling a hydraulic oil supplied from the hydraulic pump to the back pressure chamber of the piston when the third spool is switched. Hydraulic system. 제1항에 있어서,The method of claim 1, 상기 제1 스풀과 상기 포펫 사이의 유로에 입구측이 연통되고 상기 제3 스풀에 출구측이 연통되는 유로에 설치되고, 상기 유압펌프로부터 토출되어 상기 제3 스풀을 절환시키는 작동유를 제어하는 제5 오리피스를 더 포함하는 건설기계용 유압시스템.A fifth valve installed in a flow passage in which an inlet side communicates with the flow passage between the first spool and the poppet and an outlet side communicates with the third spool, and a fifth oil controlling the hydraulic fluid discharged from the hydraulic pump to switch the third spool. Hydraulic system for construction machinery further comprising an orifice. 제1항에 있어서,The method of claim 1, 상기 제2 스풀은 일측 및 타측에 제공되는 제3 포트 및 제4 포트를 포함하고, 상기 제3 포트에 인가되는 제3 파일럿 신호압에 의해 절환 시 상기 옵션장치의 제1 동작을 가능하게 하고, 상기 제4 포트에 인가되는 제4 파일럿 신호압에 의해 절환 시 상기 옵션장치의 제2 동작을 가능하게 하는 건설기계용 유압시스템.The second spool includes a third port and a fourth port provided at one side and the other side, and enables the first operation of the option device when switching by the third pilot signal pressure applied to the third port, And a second operation of the option device upon switching by a fourth pilot signal pressure applied to the fourth port. 제1항에 있어서,The method of claim 1, 상기 제1 포트에 연결되어 있는 제1 비례제어밸브 및 상기 제2 포트에 연결되어 있는 제2 비례제어밸브를 더 포함하는 건설기계용 유압시스템.And a first proportional control valve connected to the first port and a second proportional control valve connected to the second port. 제10항에 있어서,The method of claim 10, 상기 제1 파일럿 신호압은 상기 제1 비례제어밸브를 경유하여, 상기 제1 포트에 인가되고, 상기 제2 파일럿 신호압은 상기 제2 비례제어밸브를 경유하여, 상기 제2 포트에 인가되는 건설기계용 유압시스템.The first pilot signal pressure is applied to the first port via the first proportional control valve, and the second pilot signal pressure is applied to the second port via the second proportional control valve. Hydraulic system for machines.
PCT/KR2016/000256 2016-01-11 2016-01-11 Hydraulic system for construction equipment Ceased WO2017122836A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002106507A (en) * 2000-07-27 2002-04-10 Komatsu Ltd Flow control device for hydraulic actuator
JP2007315514A (en) * 2006-05-26 2007-12-06 Sumitomo (Shi) Construction Machinery Manufacturing Co Ltd Controller for working machine
KR100800081B1 (en) * 2006-08-29 2008-02-01 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 Hydraulic Circuit of Excavator Option
WO2013002429A1 (en) * 2011-06-27 2013-01-03 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic control valve for construction machinery
KR20150114949A (en) * 2013-02-05 2015-10-13 볼보 컨스트럭션 이큅먼트 에이비 Construction equipment pressure control valve

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002106507A (en) * 2000-07-27 2002-04-10 Komatsu Ltd Flow control device for hydraulic actuator
JP2007315514A (en) * 2006-05-26 2007-12-06 Sumitomo (Shi) Construction Machinery Manufacturing Co Ltd Controller for working machine
KR100800081B1 (en) * 2006-08-29 2008-02-01 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 Hydraulic Circuit of Excavator Option
WO2013002429A1 (en) * 2011-06-27 2013-01-03 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic control valve for construction machinery
KR20150114949A (en) * 2013-02-05 2015-10-13 볼보 컨스트럭션 이큅먼트 에이비 Construction equipment pressure control valve

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