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WO2016182099A1 - Hydraulic circuit for construction equipment - Google Patents

Hydraulic circuit for construction equipment Download PDF

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Publication number
WO2016182099A1
WO2016182099A1 PCT/KR2015/004768 KR2015004768W WO2016182099A1 WO 2016182099 A1 WO2016182099 A1 WO 2016182099A1 KR 2015004768 W KR2015004768 W KR 2015004768W WO 2016182099 A1 WO2016182099 A1 WO 2016182099A1
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WIPO (PCT)
Prior art keywords
hydraulic
hydraulic oil
actuator
port
hydraulic actuator
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Ceased
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PCT/KR2015/004768
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French (fr)
Korean (ko)
Inventor
주상규
구본석
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Volvo Construction Equipment AB
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Volvo Construction Equipment AB
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Priority to PCT/KR2015/004768 priority Critical patent/WO2016182099A1/en
Publication of WO2016182099A1 publication Critical patent/WO2016182099A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • 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
    • 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
    • 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 circuit, and more specifically, to a hydraulic circuit for construction machinery for controlling the hydraulic oil supplied to a plurality of hydraulic actuators from a single hydraulic pump.
  • FIG. 1 is a hydraulic circuit diagram for a construction machine according to the prior art.
  • hydraulic pump 1 As shown in Fig. 1, a variable displacement hydraulic pump (hereinafter referred to as “hydraulic pump”) 1 is connected to an engine (not shown) or the like.
  • At least one hydraulic actuator (2, 3, 4) driven by the hydraulic oil of the hydraulic pump (1) is connected to the hydraulic pump (1).
  • the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic actuators (2, 3, 4) through the pump passage (5), or discharged from the hydraulic actuators (2, 3, 4)
  • a metering valve 7 for draining the hydraulic oil to the hydraulic oil tank T through the tank oil passage 6 is installed in the flow path between the hydraulic pump 1 and the hydraulic actuators 2, 3, 4.
  • the metering valve 7 (IMV; independent metering valve)
  • Second metering valve 7b for supplying the hydraulic oil of the hydraulic pump 1 to the other port of the hydraulic actuators 2, 3, and 4 (e.g., a small chamber) during switching by application of an electrical signal.
  • Port relief valves 9 and 10 are respectively installed in the relief passage 8 connected to one port and the other port of the hydraulic actuators 2, 3 and 4.
  • the port relief valves 9 and 10 are hydraulic actuators 2, 3 and 4 when the pressure generated by the hydraulic actuators 2, 3 and 4 exceeds the set pressure of the port relief valves 9 and 10.
  • Relief valves 9a, 10a protecting the hydraulic actuators 2, 3, 4 and the hydraulic actuators 2, 3, and 4 are driven by draining a part of the hydraulic oil to the hydraulic oil tank T.
  • cavitation occurs when the pressure becomes lower than the set pressure in the hydraulic oil tank T, the hydraulic oil of the hydraulic oil tank T is transferred to the hydraulic actuators 2, 3, and 4 through the tank flow path 6. It consists of check valves 9b and 10b that supply to and compensate for.
  • the first and third metering valves ( 7a, 7c are switched to the ON state to open the opening.
  • the second and fourth metering valves 7b and 7d maintain an initial state in which the opening is blocked by the elastic force of the valve spring because no electrical signal is applied.
  • the hydraulic oil of the hydraulic pump 1 is supplied to one port of the hydraulic actuator 2 via the pump passage 5 and the first metering valve 7a.
  • the hydraulic oil discharged from the other port of the hydraulic actuator (2) is returned to the hydraulic oil tank (T) via the third metering valve (7c) and the tank flow path (6).
  • the said hydraulic actuator 2 can be extended-driven (The drive of the said hydraulic actuators 3 and 4 becomes the same as the drive of the hydraulic actuator 2, and detailed description is abbreviate
  • the hydraulic actuators 2, 3, and 4 are provided with a plurality of port relief valves 9 and 10 each consisting of relief valves 9a and 10a and check valves 9b and 10b, the number of parts constituting the hydraulic circuit is increased. There is a problem that the cost and manufacturing cost is increased, so the overall price of the equipment rises, the price competitiveness falls.
  • the present invention is to solve the above problems, in the hydraulic circuit for construction machinery to control the hydraulic fluid supplied from a single hydraulic pump to a plurality of hydraulic actuators, a plurality of hydraulic pressure by a single port relief valve when the hydraulic actuator is overloaded
  • An object of the present invention is to provide a hydraulic circuit for a construction machine that can protect an actuator.
  • At least one hydraulic actuator driven by the hydraulic oil of the hydraulic pump
  • a metering valve that supplies and compensates the hydraulic oil supplied from the hydraulic oil tank through the tank flow path to the hydraulic actuator when the pressure generated during operation of the hydraulic actuator falls below a set pressure in the hydraulic oil tank;
  • a non-return check valve installed in the first relief passage connected to the one side port and the other port of the hydraulic actuator
  • a port relief valve installed in a second relief flow passage connected to an inlet of the first relief flow passage and an outlet connected to the hydraulic oil tank, and the port relief valve is configured to generate a pressure exceeding a set pressure of the port relief valve to the hydraulic actuator. And draining a part of the hydraulic oil of the hydraulic actuator to the hydraulic oil tank through the check valve.
  • FIG. 2 is a hydraulic circuit diagram for a construction machine according to an embodiment of the present invention.
  • FIG. 2 is a hydraulic circuit diagram for a construction machine according to an embodiment of the present invention.
  • a variable displacement hydraulic pump (hereinafter referred to as "hydraulic pump") 1 is connected to an engine (not shown) or the like.
  • At least one hydraulic actuator (2, 3, 4) (e.g., an boom cylinder, an arm cylinder, a bucket cylinder of an excavator) driven by the hydraulic oil of the hydraulic pump 1 is connected to the hydraulic pump 1 Connected.
  • the hydraulic oil of the hydraulic pump 1 When switching by the application of an electrical signal, the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic actuators (2, 3, 4) through the pump flow path 5 and discharged from the hydraulic actuators (2, 3, 4) The hydraulic oil is drained to the hydraulic oil tank (T) through the tank flow path (6), and the pressure generated during the operation of the hydraulic actuators (2, 3, 4) falls below the set pressure in the hydraulic oil tank (T) to generate cavitation.
  • the hydraulic oil of the hydraulic oil tank (T) When the hydraulic oil of the hydraulic oil tank (T) is supplied to the hydraulic actuator (2, 3, 4) through the tank flow path (6) and the third, fourth untunging valve (7c, 7d) (make up)
  • the metering valve 7 is installed in the conduit between the hydraulic pump 1 and the hydraulic actuators 2, 3, 4.
  • a port relief valve 15 is installed in a second relief flow passage 14 having an inlet connected to the first relief flow passage 11 and an outlet connected to the hydraulic oil tank T, wherein the port relief valve 15 is When the pressure generated in the hydraulic actuator (2, 3, 4) exceeds the set pressure of the port relief valve 15, a part of the hydraulic oil of the hydraulic actuator (2, 3, 4) and the check valve (12 or 13) The hydraulic actuators 2, 3, and 4 may be protected by draining the hydraulic oil tank T through the two relief passages 14.
  • a first metering valve 7a for supplying hydraulic oil of the hydraulic pump 1 to one port of the hydraulic actuators 2, 3, and 4 when switching to an ON state by application of an electrical signal;
  • a second metering valve 7b for supplying hydraulic oil of the hydraulic pump 1 to the other port of the hydraulic actuators 2, 3, and 4 when switching to an ON state by applying an electrical signal;
  • the first metering valve 7a to drain the hydraulic oil discharged from the other port of the hydraulic actuators 2, 3, and 4 to the hydraulic oil tank T when switching to the ON state by applying an electrical signal.
  • the second metering valve 7b to drain the hydraulic oil discharged from one port of the hydraulic actuators 2, 3, and 4 to the hydraulic oil tank T when switching to the ON state by the application of an electrical signal. And a fourth metering valve 7d interlocked with the fourth metering valve.
  • the second and fourth metering valves 7b and 7d maintain an initial state in which the opening is blocked by the elastic force of the valve spring because no electric signal is applied.
  • the hydraulic oil from the hydraulic pump 1 is supplied to one port (large chamber) of the hydraulic actuator 2 via the pump channel 5 and the first metering valve 7a.
  • the hydraulic oil discharged from the other port (small chamber) of the hydraulic actuator 2 is returned to the hydraulic oil tank (T) via the third metering valve (7c) and the tank flow path (6).
  • the said hydraulic actuator 2 can be extended-driven (The drive of the said hydraulic actuators 3 and 4 becomes the same as the drive of the hydraulic actuator 2, and detailed description is abbreviate
  • the plurality of hydraulic actuators 2 are provided by one port relief valve 15. 3 and 4 can be protected (in the conventional hydraulic circuit, the port relief valves 9 and 10 are provided in the hydraulic actuators 2, 3 and 4, respectively).
  • the number of parts constituting the hydraulic circuit for construction machinery can be reduced, thereby reducing the cost and manufacturing cost, thereby lowering the price of the equipment.

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

Abstract

Disclosed is a hydraulic circuit for controlling hydraulic oil supplied from a single hydraulic pump to a plurality of hydraulic actuators. The hydraulic circuit, according to the present invention, comprises: at least one hydraulic actuator driven by hydraulic oil of a hydraulic pump; a metering valve that supplies the hydraulic oil of the hydraulic pump to the hydraulic actuator and drains the hydraulic oil, which is discharged from the hydraulic actuator, to a hydraulic oil tank when being switched, and compensates for the pressure generated while the hydraulic actuator is being driven, by supplying the hydraulic oil of the hydraulic oil tank to the hydraulic actuator when the pressure drops to the set pressure of the hydraulic oil tank or less; a check valve for preventing backflow that is installed on a first relief flow passage that is connected to opposite ports of the hydraulic actuator to communicate with the ports; and a port relief valve installed on a second relief flow passage to drain a part of the hydraulic oil of the hydraulic actuator to the hydraulic oil tank through the check valve when a pressure exceeding a set pressure is generated in the hydraulic actuator, wherein the second relief flow passage has an inlet connected to the first relief flow passage and an outlet connected to the hydraulic oil tank.

Description

건설기계용 유압회로Hydraulic Circuit for Construction Machinery

본 발명은 유압회로에 관한 것으로, 보다 구체적으로 설명하면, 단일 유압펌프로부터 복수의 유압 액츄에이터에 공급되는 작동유를 제어하기 위한 건설기계용 유압회로에 관한 것이다.The present invention relates to a hydraulic circuit, and more specifically, to a hydraulic circuit for construction machinery for controlling the hydraulic oil supplied to a plurality of hydraulic actuators from a single hydraulic pump.

도 1은 종래 기술에 의한 건설기계용 유압회로도이다.1 is a hydraulic circuit diagram for a construction machine according to the prior art.

도 1에 도시한 바와 같이, 가변용량형 유압펌프(이하, "유압펌프" 라고 함)(1)가 엔진(미 도시됨) 등에 연결된다.As shown in Fig. 1, a variable displacement hydraulic pump (hereinafter referred to as "hydraulic pump") 1 is connected to an engine (not shown) or the like.

상기 유압펌프(1)의 작동유에 의해 구동되는 적어도 하나 이상의 유압 액츄에이터(2,3,4)가 상기 유압펌프(1)에 연결된다.At least one hydraulic actuator (2, 3, 4) driven by the hydraulic oil of the hydraulic pump (1) is connected to the hydraulic pump (1).

전기적신호의 인가에 의해 절환시 상기 유압펌프(1)의 작동유를 펌프유로(5)를 통해 상기 유압 액츄에이터(2,3,4)에 공급하거나, 상기 유압 액츄에이터(2,3,4)로부터 배출되는 작동유를 탱크유로(6)를 통해 작동유탱크(T)로 드레인시키는 미터링밸브(7)가 상기 유압펌프(1)와 유압 액츄에이터(2,3,4) 사이의 유로에 설치된다.When switching by the application of an electrical signal, the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic actuators (2, 3, 4) through the pump passage (5), or discharged from the hydraulic actuators (2, 3, 4) A metering valve 7 for draining the hydraulic oil to the hydraulic oil tank T through the tank oil passage 6 is installed in the flow path between the hydraulic pump 1 and the hydraulic actuators 2, 3, 4.

상기 미터링밸브(7)(IMV;independent metering valve)는The metering valve 7 (IMV; independent metering valve)

전기적신호의 인가에 의해 절환시 상기 유압펌프(1)의 작동유를 유압 액츄에이터(2,3,4)의 일측 포트(일 예로서, 라지챔버를 말함)에 공급하는 제1미터링밸브(7a)와,A first metering valve 7a for supplying hydraulic oil of the hydraulic pump 1 to one side port (for example, a large chamber) of the hydraulic actuators 2, 3, and 4 when switching by application of an electrical signal; ,

전기적신호의 인가에 의해 절환시 상기 유압펌프(1)의 작동유를 상기 유압 액츄에이터(2,3,4)의 타측 포트(일 예로서, 스몰챔버를 말함)에 공급하는 제2미터링밸브(7b)와,Second metering valve 7b for supplying the hydraulic oil of the hydraulic pump 1 to the other port of the hydraulic actuators 2, 3, and 4 (e.g., a small chamber) during switching by application of an electrical signal. Wow,

전기적신호의 인가에 의해 절환시 상기 유압 액츄에이터(2,3,4)의 타측 포트로부터 배출되는 작동유를 상기 작동유탱크(T)로 드레인시키도록 상기 제1미터링밸브(7a)와 연동되는 제3미터링밸브(7c)와,A third metering interlocked with the first metering valve 7a to drain the hydraulic oil discharged from the other port of the hydraulic actuators 2, 3, 4 to the hydraulic oil tank T when the electric signal is switched by an electric signal; The valve 7c,

전기적신호의 인가에 의해 절환시 상기 유압 액츄에이터(2,3,4)의 일측 포트로부터 배출되는 작동유를 상기 작동유탱크(T)로 드레인시키도록 상기 제2미터링밸브(7b)와 연동되는 제4미터링밸브(7d)로 이루어진다.A fourth metering interlocked with the second metering valve 7b to drain the hydraulic oil discharged from one port of the hydraulic actuators 2, 3, and 4 to the hydraulic oil tank T when the electric signal is switched by an electric signal; It consists of a valve 7d.

상기 유압 액츄에이터(2,3,4)의 일측 포트 및 타측 포트에 연통되게 연결되는 릴리프유로(8)에 포트 릴리프밸브(port relief valve)(9,10)가 각각 설치된다.Port relief valves 9 and 10 are respectively installed in the relief passage 8 connected to one port and the other port of the hydraulic actuators 2, 3 and 4.

상기 포트 릴리프밸브(9,10)는 상기 유압 액츄에이터(2,3,4)에 발생되는 압력이 상기 포트 릴리프밸브(9,10)의 설정압력을 초과하는 경우 상기 유압 액츄에이터(2,3,4)의 작동유 일부를 작동유탱크(T)로 드레인시킴에 따라 유압 액츄에이터(2,3,4)를 보호하는 릴리프밸브(9a,10a)와, 상기 유압 액츄에이터(2,3,4)의 구동 중 발생되는 압력이 상기 작동유탱크(T) 내의 설정압력 이하로 떨어져 캐비테이션(cavitation)이 발생되는 경우 상기 작동유탱크(T)의 작동유를 상기 탱크유로(6)를 통해 상기 유압 액츄에이터(2,3,4)에 공급하여 보상(make up)하는 체크밸브(9b,10b)로 이루어진다.The port relief valves 9 and 10 are hydraulic actuators 2, 3 and 4 when the pressure generated by the hydraulic actuators 2, 3 and 4 exceeds the set pressure of the port relief valves 9 and 10. Relief valves 9a, 10a protecting the hydraulic actuators 2, 3, 4 and the hydraulic actuators 2, 3, and 4 are driven by draining a part of the hydraulic oil to the hydraulic oil tank T. When cavitation occurs when the pressure becomes lower than the set pressure in the hydraulic oil tank T, the hydraulic oil of the hydraulic oil tank T is transferred to the hydraulic actuators 2, 3, and 4 through the tank flow path 6. It consists of check valves 9b and 10b that supply to and compensate for.

전술한 구성에 따르면, 상기 유압 액츄에이터(2)를 신장구동시키기 위해 상기 제1,3미터링밸브(7a,7c)의 밸브스프링 대향측에 전기적신호를 인가시킬 경우, 상기 제1,3미터링밸브(7a,7c)는 온(ON) 상태로 절환되어 개구부를 개방하게 된다. 이때 상기 제2,4미터링밸브(7b,7d)는 전기적신호가 인가되지않아 밸브스프링의 탄성력에 의해 개구부를 차단시킨 초기상태를 유지하게 된다.According to the above-described configuration, when an electrical signal is applied to the valve spring opposite side of the first and third metering valves 7a and 7c to extend-drive the hydraulic actuator 2, the first and third metering valves ( 7a, 7c are switched to the ON state to open the opening. At this time, the second and fourth metering valves 7b and 7d maintain an initial state in which the opening is blocked by the elastic force of the valve spring because no electrical signal is applied.

따라서, 상기 유압펌프(1)의 작동유가 상기 펌프유로(5)와 상기 제1미터링밸브(7a)를 경유하여 유압 액츄에이터(2)의 일측 포트에 공급된다. 이때 상기 유압 액츄에이터(2)의 타측 포트로부터 배출되는 작동유는 상기 제3미터링밸브(7c)와 탱크유로(6)를 경유하여 상기 작동유탱크(T)로 리턴된다.Therefore, the hydraulic oil of the hydraulic pump 1 is supplied to one port of the hydraulic actuator 2 via the pump passage 5 and the first metering valve 7a. At this time, the hydraulic oil discharged from the other port of the hydraulic actuator (2) is returned to the hydraulic oil tank (T) via the third metering valve (7c) and the tank flow path (6).

이로 인해, 상기 유압 액츄에이터(2)를 신장구동시킬 수 있다(상기 유압 액츄에이터(3,4)의 구동은 유압 액츄에이터(2)의 구동과 동일하게 되므로 상세한 설명은 생략한다).For this reason, the said hydraulic actuator 2 can be extended-driven (The drive of the said hydraulic actuators 3 and 4 becomes the same as the drive of the hydraulic actuator 2, and detailed description is abbreviate | omitted.).

상기 유압 액츄에이터(2,3,4)에 릴리프밸브(9a,10a) 및 체크밸브(9b,10b)로 이루어진 복수개의 포트 릴리프밸브(9,10)가 각각 구비됨에 따라, 유압회로를 이루는 부품수가 많아져 원가 및 제작비용이 상승되므로 장비의 전체 가격이 올라 가격경쟁력이 떨어지는 문제점이 있다.As the hydraulic actuators 2, 3, and 4 are provided with a plurality of port relief valves 9 and 10 each consisting of relief valves 9a and 10a and check valves 9b and 10b, the number of parts constituting the hydraulic circuit is increased. There is a problem that the cost and manufacturing cost is increased, so the overall price of the equipment rises, the price competitiveness falls.

따라서, 본 발명은 전술한 문제점을 해결하고자 하는 것으로, 단일 유압펌프로부터 복수의 유압 액츄에이터에 공급되는 작동유를 제어하는 건설기계용 유압회로에서, 유압 액츄에이터에 과부하 발생시 단일 포트 릴리프밸브에 의해 다수의 유압 액츄에이터를 보호할 수 있는 건설기계용 유압회로를 제공하는 것을 목적으로 한다.Accordingly, the present invention is to solve the above problems, in the hydraulic circuit for construction machinery to control the hydraulic fluid supplied from a single hydraulic pump to a plurality of hydraulic actuators, a plurality of hydraulic pressure by a single port relief valve when the hydraulic actuator is overloaded An object of the present invention is to provide a hydraulic circuit for a construction machine that can protect an actuator.

상기 및 기타 본 발명의 목적을 달성하기 위하여 본 발명의 일실시예에 따르면,According to one embodiment of the present invention to achieve the above and other objects of the present invention,

가변용량형 유압펌프;Variable displacement hydraulic pump;

상기 유압펌프의 작동유에 의해 구동되는 적어도 하나 이상의 유압 액츄에이터;At least one hydraulic actuator driven by the hydraulic oil of the hydraulic pump;

상기 유압펌프와 유압 액츄에이터 사이의 유로에 설치되고, 절환시 상기 유압펌프의 작동유를 펌프유로를 통해 상기 유압 액츄에이터에 공급하고 상기 유압 액츄에이터로부터 배출되는 작동유를 탱크유로를 통해 작동유탱크로 드레인시키며, 상기 유압 액츄에이터의 구동 중 발생되는 압력이 상기 작동유탱크 내의 설정압력 이하로 떨어지는 경우 상기 작동유탱크로부터 상기 탱크유로를 통해 공급되는 작동유를 상기 유압 액츄에이터에 공급하여 보상하는 미터링밸브;Is installed in the flow path between the hydraulic pump and the hydraulic actuator, when switching the hydraulic oil of the hydraulic pump to the hydraulic actuator through the pump flow path and the hydraulic oil discharged from the hydraulic actuator to the hydraulic oil tank through the tank flow path, A metering valve that supplies and compensates the hydraulic oil supplied from the hydraulic oil tank through the tank flow path to the hydraulic actuator when the pressure generated during operation of the hydraulic actuator falls below a set pressure in the hydraulic oil tank;

상기 유압 액츄에이터의 일측 포트 및 타측 포트에 연통되게 연결되는 제1릴리프유로에 설치되는 역류방지용 체크밸브;A non-return check valve installed in the first relief passage connected to the one side port and the other port of the hydraulic actuator;

상기 제1릴리프유로에 입구가 연결되고 상기 작동유탱크에 출구가 연결되는 제2릴리프유로에 설치되는 포트 릴리프밸브, 상기 포트 릴리프밸브는 상기 유압 액츄에이터에 상기 포트 릴리프밸브의 설정압력을 초과하는 압력 발생시 상기 유압 액츄에이터의 작동유 일부를 상기 체크밸브를 통해 상기 작동유탱크로 드레인시킴;을 특징으로 하는 건설기계용 유압회로를 제공한다.A port relief valve installed in a second relief flow passage connected to an inlet of the first relief flow passage and an outlet connected to the hydraulic oil tank, and the port relief valve is configured to generate a pressure exceeding a set pressure of the port relief valve to the hydraulic actuator. And draining a part of the hydraulic oil of the hydraulic actuator to the hydraulic oil tank through the check valve.

전술한 구성을 갖는 본 발명에 따르면, 단일 유압펌프로부터 복수의 유압 액츄에이터에 공급되는 작동유를 제어하는 유압회로를 구성하는 릴리프밸브 숫자를 줄여 원가 및 제작비용이 절감되므로 장비 전체의 가격을 낮추고, 사후관리비용을 절감할 수 있는 효과가 있다.According to the present invention having the above-described configuration, by reducing the number of the relief valve constituting the hydraulic circuit for controlling the hydraulic oil supplied to a plurality of hydraulic actuators from a single hydraulic pump, cost and manufacturing cost is reduced, thereby lowering the overall price of the equipment, It can reduce the management cost.

도 1은 종래 기술에 의한 건설기계용 유압회로도,1 is a hydraulic circuit diagram for a construction machine according to the prior art,

도 2는 본 발명의 일 실시예에 의한 건설기계용 유압회로도이다.2 is a hydraulic circuit diagram for a construction machine according to an embodiment of the present invention.

〈도면의 주요 부분에 대한 참조 부호의 설명〉<Explanation of reference numerals for the main parts of the drawings>

1; 유압펌프One; Hydraulic pump

2,3,4; 유압 액츄에이터2,3,4; Hydraulic actuator

5; 펌프유로5; Pump flow path

6; 탱크유로6; Tank Euro

7; 미터링밸브(IMV;independent metering valve)7; Independent metering valve (IMV)

11; 제1릴리프유로11; First Reef Euro

12,13; 체크밸브12,13; Check valve

14; 제2릴리프유로14; Second relief euro

15; 포트 릴리프밸브15; Port Relief Valve

이하, 첨부도면을 참조하여 본 발명의 바람직한 실시예에 따른 건설기계용 유압회로를 상세히 설명하기로 한다.Hereinafter, a hydraulic circuit for a construction machine according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

도 2는 본 발명의 일 실시예에 의한 건설기계용 유압회로도이다.2 is a hydraulic circuit diagram for a construction machine according to an embodiment of the present invention.

도 2를 참조하면, 본 발명의 일 실시예에 따른 건설기계용 유압회로는,2, the hydraulic circuit for a construction machine according to an embodiment of the present invention,

가변용량형 유압펌프(이하 "유압펌프" 라고 함)(1)가 엔진(미 도시됨) 등에 연결된다.A variable displacement hydraulic pump (hereinafter referred to as "hydraulic pump") 1 is connected to an engine (not shown) or the like.

상기 유압펌프(1)의 작동유에 의해 구동되는 적어도 하나 이상의 유압 액츄에이터(2,3,4)(일 예로서, 굴삭기의 붐실린더, 아암실린더, 버킷실린더를 말함)가 상기 유압펌프(1)에 연결된다.At least one hydraulic actuator (2, 3, 4) (e.g., an boom cylinder, an arm cylinder, a bucket cylinder of an excavator) driven by the hydraulic oil of the hydraulic pump 1 is connected to the hydraulic pump 1 Connected.

전기적신호의 인가에 의해 절환시 상기 유압펌프(1)의 작동유를 펌프유로(5)를 통해 상기 유압 액츄에이터(2,3,4)에 공급하고 상기 유압 액츄에이터(2,3,4)로부터 배출되는 작동유를 탱크유로(6)를 통해 작동유탱크(T)로 드레인시키며, 상기 유압 액츄에이터(2,3,4)의 구동 중 발생되는 압력이 상기 작동유탱크(T) 내의 설정압력 이하로 떨어져 캐비테이션이 발생되는 경우 상기 작동유탱크(T)의 작동유를 상기 탱크유로(6) 및 제3,4미텅링밸브(7c,7d)를 통해 상기 유압 액츄에이터(2,3,4)에 공급하여 보상(make up)하는 미터링밸브(7)가 상기 유압펌프(1)와 유압 액츄에이터(2,3,4) 사이의 관로에 설치된다.When switching by the application of an electrical signal, the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic actuators (2, 3, 4) through the pump flow path 5 and discharged from the hydraulic actuators (2, 3, 4) The hydraulic oil is drained to the hydraulic oil tank (T) through the tank flow path (6), and the pressure generated during the operation of the hydraulic actuators (2, 3, 4) falls below the set pressure in the hydraulic oil tank (T) to generate cavitation. When the hydraulic oil of the hydraulic oil tank (T) is supplied to the hydraulic actuator (2, 3, 4) through the tank flow path (6) and the third, fourth untunging valve (7c, 7d) (make up) The metering valve 7 is installed in the conduit between the hydraulic pump 1 and the hydraulic actuators 2, 3, 4.

이때, 전기적신호의 인가에 의해 절환시 상기 유압펌프(1)로부터 상기 유압 액츄에이터(3,4)에 대해 공급 및 배출되는 작동유를 제어하는 미터링밸브(7)의 구성은, 상기 유압 액츄에이터(2)에 연결되는 미터링밸브(7)의 구성과 동일하므로 상세한 설명은 생략한다.At this time, the configuration of the metering valve (7) for controlling the hydraulic oil supplied and discharged from the hydraulic pump (1) to the hydraulic actuator (3,4) at the time of switching by the application of an electrical signal, the hydraulic actuator (2) Since the same configuration as the metering valve 7 connected to the detailed description thereof will be omitted.

상기 유압 액츄에이터(2,3,4)의 일측 포트(일 예로서, 라지챔버를 말함) 및 타측 포트(일 예로서, 스몰챔버를 말함)에 연통되게 연결되는 제1릴리프유로(11)에 역류방지용 체크밸브(12,13)가 설치된다.Counter flow to the first relief passage 11 connected in communication with one port (eg, a large chamber) and the other port (eg, a small chamber) of the hydraulic actuators 2, 3, and 4. Preventive check valves 12 and 13 are provided.

상기 제1릴리프유로(11)에 입구가 연결되고 상기 작동유탱크(T)에 출구가 연결되는 제2릴리프유로(14)에 포트 릴리프밸브(15)를 설치하되, 상기 포트 릴리프밸브(15)는 상기 유압 액츄에이터(2,3,4)에 상기 포트 릴리프밸브(15)의 설정압력을 초과하는 압력 발생시 상기 유압 액츄에이터(2,3,4)의 작동유 일부를 상기 체크밸브(12 또는 13) 및 제2릴리프유로(14)를 통해 상기 작동유탱크(T)로 드레인시킴에 따라 유압 액츄에이터(2,3,4)를 보호할 수 있다.A port relief valve 15 is installed in a second relief flow passage 14 having an inlet connected to the first relief flow passage 11 and an outlet connected to the hydraulic oil tank T, wherein the port relief valve 15 is When the pressure generated in the hydraulic actuator (2, 3, 4) exceeds the set pressure of the port relief valve 15, a part of the hydraulic oil of the hydraulic actuator (2, 3, 4) and the check valve (12 or 13) The hydraulic actuators 2, 3, and 4 may be protected by draining the hydraulic oil tank T through the two relief passages 14.

상기 미터링밸브(7)는The metering valve 7

전기적신호의 인가에 의해 온(ON) 상태로 절환시 상기 유압펌프(1)의 작동유를 상기 유압 액츄에이터(2,3,4)의 일측 포트에 공급하는 제1미터링밸브(7a)와,A first metering valve 7a for supplying hydraulic oil of the hydraulic pump 1 to one port of the hydraulic actuators 2, 3, and 4 when switching to an ON state by application of an electrical signal;

전기적신호의 인가에 의해 온(ON) 상태로 절환시 상기 유압펌프(1)의 작동유를 상기 유압 액츄에이터(2,3,4)의 타측 포트에 공급하는 제2미터링밸브(7b)와,A second metering valve 7b for supplying hydraulic oil of the hydraulic pump 1 to the other port of the hydraulic actuators 2, 3, and 4 when switching to an ON state by applying an electrical signal;

전기적신호의 인가에 의해 온(ON) 상태로 절환시 상기 유압 액츄에이터(2,3,4)의 타측 포트로부터 배출되는 작동유를 상기 작동유탱크(T)로 드레인시키도록 상기 제1미터링밸브(7a)와 연동되는 제3미터링밸브(7c)와,The first metering valve 7a to drain the hydraulic oil discharged from the other port of the hydraulic actuators 2, 3, and 4 to the hydraulic oil tank T when switching to the ON state by applying an electrical signal. A third metering valve 7c interlocked with the

전기적신호의 인가에 의해 온(ON) 상태로 절환시 상기 유압 액츄에이터(2,3,4)의 일측 포트로부터 배출되는 작동유를 상기 작동유탱크(T)로 드레인시키도록 상기 제2미터링밸브(7b)와 연동되는 제4미터링밸브(7d)로 이루어질 수 있다.The second metering valve 7b to drain the hydraulic oil discharged from one port of the hydraulic actuators 2, 3, and 4 to the hydraulic oil tank T when switching to the ON state by the application of an electrical signal. And a fourth metering valve 7d interlocked with the fourth metering valve.

전술한 구성을 따르면, 상기 유압 액츄에이터(2)를 신장구동시키기 위해 상기 제1,3미터링밸브(7a,7c)의 밸브스프링 대향측에 전기적신호를 인가시킬 경우에 상기 제1,3미터링밸브(7a,7c)는 온(ON) 상태로 절환되어 개구부를 개방하게 된다.According to the above-described configuration, when the electrical signal is applied to the valve spring opposite side of the first and third metering valves 7a and 7c to extend-drive the hydraulic actuator 2, the first and third metering valves ( 7a, 7c are switched to the ON state to open the opening.

이때, 상기 제2,4미터링밸브(7b,7d)는 전기적신호가 인가되지않아 밸브스프링의 탄성력에 의해 개구부를 차단시킨 초기상태를 유지하게 된다.At this time, the second and fourth metering valves 7b and 7d maintain an initial state in which the opening is blocked by the elastic force of the valve spring because no electric signal is applied.

따라서, 상기 유압펌프(1)로부터의 작동유가 상기 펌프유로(5)와 상기 제1미터링밸브(7a)를 경유하여 유압 액츄에이터(2)의 일측 포트(라지챔버)에 공급된다. 이때 상기 유압 액츄에이터(2)의 타측 포트(스몰챔버)로부터 배출되는 작동유는 상기 제3미터링밸브(7c)와 탱크유로(6)를 경유하여 상기 작동유탱크(T)로 리턴된다.Therefore, the hydraulic oil from the hydraulic pump 1 is supplied to one port (large chamber) of the hydraulic actuator 2 via the pump channel 5 and the first metering valve 7a. At this time, the hydraulic oil discharged from the other port (small chamber) of the hydraulic actuator 2 is returned to the hydraulic oil tank (T) via the third metering valve (7c) and the tank flow path (6).

이로 인해, 상기 유압 액츄에이터(2)를 신장구동시킬 수 있다(상기 유압 액츄에이터(3,4)의 구동은 유압 액츄에이터(2)의 구동과 동일하게 되므로 상세한 설명은 생략한다).For this reason, the said hydraulic actuator 2 can be extended-driven (The drive of the said hydraulic actuators 3 and 4 becomes the same as the drive of the hydraulic actuator 2, and detailed description is abbreviate | omitted.).

전술한 바와 같이 상기 유압펌프(1)로부터 공급되는 작동유에 의해 구동되는 상기 유압 액츄에이터(2,3,4)에 발생되는 압력이 상기 포트 릴리프밸브(15)의 설정압력을 초과하는 경우, 상기 유압 액츄에이터(2,3,4)의 작동유 일부는 상기 체크밸브(12 또는 13)와 제2릴리프유로(14) 및 포트 릴리프밸브(15)를 차례로 통과하여 작동유 탱크(T)로 드레인된다(즉 유압 액츄에이터(2,3,4)에 발생되는 압력이 포트 릴리프밸브(15)의 설정압력을 초과할 수 없게 된다).As described above, when the pressure generated in the hydraulic actuators 2, 3, 4 driven by the hydraulic oil supplied from the hydraulic pump 1 exceeds the set pressure of the port relief valve 15, the hydraulic pressure A part of the hydraulic oil of the actuators 2, 3, and 4 passes through the check valve 12 or 13, the second relief flow passage 14, and the port relief valve 15 in order to be drained into the hydraulic oil tank T (i.e., hydraulic pressure). The pressure generated in the actuators 2, 3, and 4 cannot exceed the set pressure of the port relief valve 15).

따라서, 상기 유압 액츄에이터(2,3,4)의 구동시 상기 포트 릴리프밸브(15)의 설정압력을 초과하는 압력이 발생되는 경우에 하나의 포트 릴리프밸브(15)에 의해 복수의 유압 액츄에이터(2,3,4)를 보호할 수 있다(종래의 유압회로에서는 유압 액츄에이터(2,3,4)에 포트 릴리프밸브(9,10)가 각각 구비됨). 이로 인해 건설기계용 유압회로를 구성하는 부품수를 줄여 원가 및 제작비용을 절감하므로 장비의 가격을 낮출 수 있다.Accordingly, when a pressure exceeding a set pressure of the port relief valve 15 is generated when the hydraulic actuators 2, 3, 4 are driven, the plurality of hydraulic actuators 2 are provided by one port relief valve 15. 3 and 4 can be protected (in the conventional hydraulic circuit, the port relief valves 9 and 10 are provided in the hydraulic actuators 2, 3 and 4, respectively). As a result, the number of parts constituting the hydraulic circuit for construction machinery can be reduced, thereby reducing the cost and manufacturing cost, thereby lowering the price of the equipment.

한편, 상기 유압 액츄에이터(2,3,4)의 작동 중 발생되는 압력이 상기 작동유탱크(T) 내의 설정압력 이하로 떨어져 캐비테이션이 발생되는 경우, 상기 작동유탱크(T)의 작동유를 상기 탱크유로(6) 및 제3,4미터링밸브(7c 또는 7d)를 통해 상기 유압 액츄에이터(2,3,4)에 공급하여 보상하게 되므로 캐비테이션을 방지할 수 있다.On the other hand, when cavitation occurs because the pressure generated during operation of the hydraulic actuators (2, 3, 4) falls below the set pressure in the hydraulic oil tank (T), the hydraulic oil of the hydraulic oil tank (T) is the tank flow path ( 6) and the third and fourth metering valves (7c or 7d) through the supply to the hydraulic actuators (2, 3, 4) to compensate for cavitation can be prevented.

여기에서, 상술한 본 발명에서는 바람직한 실시예를 참조하여 설명하였지만, 해당 기술분야에서 숙련된 당업자는 하기의 특허청구범위에 기재된 본 발명의 사상 및 영역으로부터 벗어나지 않는 범위 내에서 본 발명을 다양하게 수정 및 변경할 수 있음을 이해할 수 있을 것이다.Herein, although the present invention has been described with reference to the preferred embodiments, those skilled in the art will variously modify the present invention without departing from the spirit and scope of the invention as set forth in the claims below. And can be changed.

전술한 구성을 갖는 본 발명에 따르면, 미터링밸브가 구비되는 건설기계용 유압회로에서 단일 유압펌프로부터 복수의 유압 액츄에이터에 공급되는 작동유를 제어할 수 있는 효과가 있다.According to the present invention having the above-described configuration, in the hydraulic circuit for a construction machine provided with a metering valve has the effect of controlling the hydraulic oil supplied to a plurality of hydraulic actuators from a single hydraulic pump.

Claims (3)

유압펌프;Hydraulic pump; 상기 유압펌프의 작동유에 의해 구동되는 적어도 하나 이상의 유압 액츄에이터;At least one hydraulic actuator driven by the hydraulic oil of the hydraulic pump; 상기 유압펌프와 유압 액츄에이터 사이의 유로에 설치되고, 절환시 상기 유압펌프의 작동유를 펌프유로를 통해 상기 유압 액츄에이터에 공급하고 상기 유압 액츄에이터로부터 배출되는 작동유를 탱크유로를 통해 작동유탱크로 드레인시키며, 상기 유압 액츄에이터의 구동 중 발생되는 압력이 상기 작동유탱크 내의 설정압력 이하로 떨어지는 경우 상기 작동유탱크로부터 상기 탱크유로를 통해 공급되는 작동유를 상기 유압 액츄에이터에 공급하여 보상하는 미터링밸브;Is installed in the flow path between the hydraulic pump and the hydraulic actuator, when switching the hydraulic oil of the hydraulic pump to the hydraulic actuator through the pump flow path and the hydraulic oil discharged from the hydraulic actuator to the hydraulic oil tank through the tank flow path, A metering valve that supplies and compensates the hydraulic oil supplied from the hydraulic oil tank through the tank flow path to the hydraulic actuator when the pressure generated during operation of the hydraulic actuator falls below a set pressure in the hydraulic oil tank; 상기 유압 액츄에이터의 일측 포트 및 타측 포트에 연통되게 연결되는 제1릴리프유로에 설치되는 역류방지용 체크밸브;A non-return check valve installed in the first relief passage connected to the one side port and the other port of the hydraulic actuator; 상기 제1릴리프유로에 입구가 연결되고 상기 작동유탱크에 출구가 연결되는 제2릴리프유로에 설치되는 포트 릴리프밸브, 상기 포트 릴리프밸브는 상기 유압 액츄에이터에 상기 포트 릴리프밸브의 설정압력을 초과하는 압력 발생시 상기 유압 액츄에이터의 작동유 일부를 상기 체크밸브를 통해 상기 작동유탱크로 드레인시킴;을 특징으로 하는 건설기계용 유압회로.A port relief valve installed in a second relief flow passage connected to an inlet of the first relief flow passage and an outlet connected to the hydraulic oil tank, and the port relief valve is configured to generate a pressure exceeding a set pressure of the port relief valve to the hydraulic actuator. And draining a part of the hydraulic oil of the hydraulic actuator to the hydraulic oil tank through the check valve. 제1항에 있어서, 상기 미터링밸브는The method of claim 1, wherein the metering valve 전기적신호의 인가에 의해 절환시 상기 유압펌프의 작동유를 상기 유압 액츄에이터의 일측 포트에 공급하는 제1미터링밸브와,A first metering valve for supplying hydraulic oil of the hydraulic pump to one port of the hydraulic actuator at the time of switching by application of an electrical signal; 전기적신호의 인가에 의해 절환시 상기 유압펌프의 작동유를 상기 유압 액츄에이터의 타측 포트에 공급하는 제2미터링밸브와,A second metering valve for supplying hydraulic oil of the hydraulic pump to the other port of the hydraulic actuator when switching by applying an electric signal; 전기적신호의 인가에 의해 절환시 상기 유압 액츄에이터의 타측 포트로부터 배출되는 작동유를 상기 작동유탱크로 드레인시키도록 상기 제1미터링밸브와 연동되는 제3미터링밸브와,A third metering valve interlocked with the first metering valve to drain the hydraulic oil discharged from the other port of the hydraulic actuator to the hydraulic oil tank when the electric switch is applied by an electric signal; 전기적신호의 인가에 의해 절환시 상기 유압 액츄에이터의 일측 포트로부터 배출되는 작동유를 상기 작동유탱크로 드레인시키도록 상기 제2미터링밸브와 연동되는 제4미터링밸브로 이루어지는 것을 특징으로 하는 건설기계용 유압회로.And a fourth metering valve interlocked with the second metering valve to drain the hydraulic oil discharged from one port of the hydraulic actuator to the hydraulic oil tank when the electric switch is applied by an electrical signal. 제1항에 있어서,The method of claim 1, 상기 유압 액츄에이터는 붐실린더, 아암실린더 및 버킷실린더 중 어느 하나인 것을 특징으로 하는 건설기계용 유압회로.The hydraulic actuator is a hydraulic circuit for a construction machine, characterized in that any one of the boom cylinder, the arm cylinder and the bucket cylinder.
PCT/KR2015/004768 2015-05-12 2015-05-12 Hydraulic circuit for construction equipment Ceased WO2016182099A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0567655U (en) * 1992-05-20 1993-09-07 日立建機株式会社 Hydraulic circuit of hydraulic excavator
KR20060106661A (en) * 2005-03-31 2006-10-12 나부테스코 가부시키가이샤 Hydraulic circuits and their valve devices
JP2013072444A (en) * 2011-09-26 2013-04-22 Kobe Steel Ltd Hydraulic driving apparatus for working machine
KR20140050004A (en) * 2011-07-12 2014-04-28 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic actuator damping control system for construction machinery
KR101389956B1 (en) * 2007-04-25 2014-04-30 가야바코교 가부시기가이샤 Fluid pressure drive unit and snow removal unit

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0567655U (en) * 1992-05-20 1993-09-07 日立建機株式会社 Hydraulic circuit of hydraulic excavator
KR20060106661A (en) * 2005-03-31 2006-10-12 나부테스코 가부시키가이샤 Hydraulic circuits and their valve devices
KR101389956B1 (en) * 2007-04-25 2014-04-30 가야바코교 가부시기가이샤 Fluid pressure drive unit and snow removal unit
KR20140050004A (en) * 2011-07-12 2014-04-28 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic actuator damping control system for construction machinery
JP2013072444A (en) * 2011-09-26 2013-04-22 Kobe Steel Ltd Hydraulic driving apparatus for working machine

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