WO2017018557A1 - Hydraulic circuit for construction machine - Google Patents
Hydraulic circuit for construction machine Download PDFInfo
- Publication number
- WO2017018557A1 WO2017018557A1 PCT/KR2015/007867 KR2015007867W WO2017018557A1 WO 2017018557 A1 WO2017018557 A1 WO 2017018557A1 KR 2015007867 W KR2015007867 W KR 2015007867W WO 2017018557 A1 WO2017018557 A1 WO 2017018557A1
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- WIPO (PCT)
- Prior art keywords
- hydraulic
- control valve
- hydraulic cylinder
- pump
- hydraulic oil
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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
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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
- E02F9/22—Hydraulic or pneumatic drives
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- 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 from the hydraulic pump to the hydraulic cylinder and the hydraulic oil returned from the hydraulic cylinder to the hydraulic oil tank.
- FIG. 1 is a hydraulic circuit diagram for a construction machine according to the prior art.
- a variable displacement hydraulic pump (hereinafter referred to as a hydraulic pump) 1 and a pilot pump 2 are connected to an engine (not shown).
- a hydraulic cylinder 3 driven by hydraulic oil supplied from the hydraulic pump 1 is connected to the hydraulic pump 1.
- An operation lever RCV (not shown) for outputting a pilot pressure corresponding to the operation amount is provided in a flow path between the pilot pump 2 and the control valve 4.
- the hydraulic oil of the hydraulic pump 1 passes through the spool of the control valve 4 and is supplied to the first chamber 3a of the hydraulic cylinder 3, and the second chamber 3b of the hydraulic cylinder 3 is provided.
- the hydraulic oil discharged from) passes through the spool of the control valve 4 and is returned to the hydraulic oil tank (T). Therefore, the hydraulic cylinder 3 can be extended and driven.
- the hydraulic oil of the hydraulic pump 1 passes through the spool of the control valve 4 and is supplied to the second chamber 3b of the hydraulic cylinder 3, and the first chamber 3a of the hydraulic cylinder 1 is supplied.
- the hydraulic oil discharged from) passes through the spool of the control valve 4 and is returned to the hydraulic oil tank (T). Therefore, it is possible to shrink-drive the hydraulic cylinder 3.
- the hydraulic oil supplied from the hydraulic pump 1 to the hydraulic cylinder 3 by the operation of the operation lever, and the amount of hydraulic oil discharged from the hydraulic cylinder 3 and returned to the hydraulic oil tank T is It is determined according to the opening area of the spool of the control valve 4 switched corresponding to the operation amount of the operation lever.
- the notch for supplying the hydraulic oil of the hydraulic pump 1 to the hydraulic cylinder 3 and the notch for returning the hydraulic oil discharged from the hydraulic cylinder 3 to the hydraulic oil tank T are the control valves. It is because it forms in two places in the spool of (4).
- the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic cylinder 3 according to the pressure generated in the hydraulic cylinder 3 or the movement of the equipment while the hydraulic cylinder 3 is extended or driven.
- Independent control of the spool opening area of the control valve (4) for supply to the control valve and the spool opening area of the control valve (4) for returning the hydraulic oil discharged from the hydraulic cylinder (3) to the hydraulic oil tank (T) You will not be able to.
- the opening area of the spool of the control valve 4 for returning to the valve is controlled dependently by the pilot pressure applied to the control valve 4 by the operation of the operation lever.
- the present invention is to solve the above-mentioned problems, dualizing the control valve for supplying the hydraulic oil of the hydraulic pump to the hydraulic cylinder or the hydraulic oil discharged from the hydraulic cylinder to the hydraulic oil tank in accordance with the pressure generated in the hydraulic cylinder It is an object of the present invention to provide a hydraulic circuit for construction machinery that can be controlled independently.
- variable displacement hydraulic pump and a pilot pump a variable displacement hydraulic pump and a pilot pump
- a hydraulic cylinder driven by the hydraulic oil supplied from the hydraulic pump
- a hydraulic circuit for a construction machine characterized in that it comprises a proportional control valve for switching by applying a pilot pressure corresponding to the operation amount of the electric operation lever to the first control valve and the second control valve.
- the present invention having the above-described configuration, during the operation of driving the hydraulic cylinder, supplying the hydraulic oil of the hydraulic pump to the hydraulic cylinder in accordance with the pressure generated in the hydraulic cylinder, or to control the hydraulic oil returned from the hydraulic cylinder to the hydraulic oil tank
- By independently controlling the control valve for the dual it is possible to prevent excessive pressure rise in the hydraulic cylinder, it is possible to increase the working speed by adjusting the operating flow rate supplied to the hydraulic cylinder.
- FIG. 2 is a hydraulic circuit diagram for a construction machine according to a preferred embodiment of the present invention.
- FIG. 2 is a hydraulic circuit diagram for a construction machine according to a preferred embodiment of the present invention.
- a variable displacement hydraulic pump (hereinafter referred to as a hydraulic pump) 10 and a pilot pump 11 are connected to the engine (not shown).
- the hydraulic cylinder 12 driven by the hydraulic oil supplied from the hydraulic pump 10 is connected to the hydraulic pump 10.
- a first control valve (MCV) 14 for returning the hydraulic oil discharged from the first chamber 12a of the cylinder 12 to the hydraulic oil tank T is a flow path between the hydraulic pump 10 and the hydraulic cylinder 12. Is installed on.
- the second control valve (MCV) 15 for returning to (T) or supplying the hydraulic oil of the hydraulic pump 10 to the second chamber 12b of the hydraulic cylinder 12 is the hydraulic pump 10 And a flow path between the hydraulic cylinder 12.
- the hydraulic oil supplied from the pilot pump 11 is transferred to the electric control lever 13.
- the pilot pump has a proportional control valve 16 that converts the secondary pilot pressure to correspond to the manipulated variable and applies the secondary pilot pressure to the first control valve 14 and the second control valve 15 to switch the pilot pressure. (11) and the flow path between the first control valve 14 and the flow path between the pilot pump 11 and the second control valve (15).
- PPRV proportional pilot reducing valve
- the first and second proportional control valves 17 and 18 and the third and fourth proportional control valves 19 and 20 provide electrical signals generated by manipulation of the electric control lever 13.
- the hydraulic cylinder 12 is any one of the boom cylinder, the arm cylinder and the bucket cylinder of the excavator.
- the opening area of the spool of the first control valve 14 and the second control valve 15 is adjusted according to the magnitude of the pressure generated in the hydraulic cylinder 12 or the machine motion.
- the flow path between the first control valve 14 and the hydraulic cylinder 12 and the flow path between the second control valve 15 and the hydraulic cylinder 12 is installed in the first It may be provided with a pressure sensor for detecting the pressure generated in the first chamber (12a) and the second chamber (12b).
- the electrical signal resulting from operating the electric control lever 13 to drive the hydraulic cylinder 12 in an extension drive is the first proportional control valve 17.
- the second proportional control valve 18 are applied simultaneously.
- the hydraulic cylinder 12 can be extended and driven.
- the electrical signal generated by operating the electric control lever 13 to contract the hydraulic cylinder 12 is the third proportional control valve 19.
- the fourth proportional control valve 20 are applied simultaneously.
- the electric control lever 13 is operated to switch the first and second control valves 14 and 15 by switching the first and second proportional control valves 17 and 18 so that the hydraulic cylinder ( 12) or the first and second control valves 14 and 15 by switching between the third and fourth proportional control valves 19 and 20 by operating the electric operation lever 13.
- the hydraulic cylinder 12 can be driven to shrink.
- the pressure detection signal generated on the first and second chambers 12a and 12b of the hydraulic cylinder 12 by the pressure sensor is input to the control unit ECU not shown, the electric operation is performed by the control unit.
- the electrical signals applied to the first and second proportional control valves 17 and 18 or the third and fourth proportional control valves 19 and 20 are adjusted.
- the first, second, third, and fourth proportional control valves 17, 18, 19, and 20 are controlled by controlling the electrical signals applied to the first, second, third, and fourth proportional control valves 13.
- the magnitude of the pilot pressure applied to the first and second control valves 14 and 15 may be adjusted in the 3, 4 proportional control valves 17, 18, 19, and 20. Therefore, the opening area of the spool of the first and second control valves 14 and 15 can be controlled independently.
- the first and second control valves 14 and 15 are switched by the operation of the electric operation lever 13 to supply the hydraulic oil of the hydraulic pump 10 to the hydraulic cylinder 12 and the hydraulic cylinder (
- the first and second control valves by the operation of the electric operation lever 13 according to the pressure generated in the hydraulic cylinder 12 (
- the spool opening area of 14, 15 can be controlled differently.
- the electric signal by the operation of the electric operation lever 13 is simultaneously applied to the first and second proportional control valves 17 and 18 so that the first As the two control valves 14 and 15 are switched, the hydraulic oil of the hydraulic pump 10 passes through the first control valve 14 to be supplied to the first chamber 12a of the hydraulic cylinder 12.
- the hydraulic oil discharged from the second chamber 12b of the hydraulic cylinder 12 may be returned to the hydraulic oil tank T. Therefore, the hydraulic cylinder 12 can be extended and driven.
- the first and second control valves 14 and 15 are switched by simultaneously applying electric signals generated by the operation of the electric control lever 13 to the third and fourth proportional control valves 19 and 20. Accordingly, the hydraulic oil of the hydraulic pump 10 passes through the second control valve 15 to be supplied to the second chamber 12b of the hydraulic cylinder 12, and the first chamber 12a of the hydraulic cylinder 12 is provided. The hydraulic oil discharged from the tank can be returned to the hydraulic oil tank (T). Therefore, the hydraulic cylinder 12 can be driven to shrink.
- the hydraulic cylinder 3 is supplied from the hydraulic pump 1 to the hydraulic cylinder 3 by spool switching of one control valve 4 (MCV) during expansion and contraction operation of the hydraulic cylinder 3.
- MCV control valve 4
- various priority valves or flow control valves on the main control valve (MCV) and the boom down side Booster valves are installed.
- equipment to which an electromagnetic hydraulic valve system (not shown) equipped with an independent metering valve (IMV) is applied is provided with a proportional valve installed on top of a poppet installed in a supply passage of a hydraulic pump.
- IMV independent metering valve
- the electrohydraulic valve system has a disadvantage in that wear occurs in the seat of the poppet due to the impact of the opening / closing cycle.
- the control performance of the poppet decreases due to the wear of the seat, the state of mounting the poppet alone and the performance of the electrohydraulic valve system combining the poppet and the electromagnetic proportional valve are different, thereby making it necessary to modify the electrohydraulic valve system.
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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)
- Operation Control Of Excavators (AREA)
Abstract
Disclosed is a hydraulic circuit for controlling operation oil, which is supplied from a hydraulic pump to a hydraulic cylinder, and operation oil, which is returned from the hydraulic cylinder to an operation oil tank. The present invention provides a hydraulic circuit for a construction machine, characterized by comprising: a hydraulic pump and a pilot pump; a hydraulic cylinder driven by operation oil from the hydraulic pump; an electrically manipulated level; a first control valve installed in a channel between the hydraulic pump and the hydraulic cylinder so as to supply, when switching, operation oil from the hydraulic pump to a first chamber of the hydraulic cylinder or to return operation oil, which is discharged from the first chamber of the hydraulic cylinder, to an operation oil tank; a second control valve installed in a channel between the hydraulic pump and the hydraulic cylinder so as to return, when switching simultaneously with the first control valve, operation oil, which is discharged from a second chamber of the hydraulic cylinder, to the operation oil tank or to supply operation oil from the hydraulic pump to the second chamber of the hydraulic cylinder; and proportional control valves installed in a channel between the pilot pump and the first control valve and in a channel between the pilot pump and the second control valve, respectively, such that, in order to independently control the spool opening area of the first and second control valves, a pilot pressure corresponding to the amount of manipulation of the electronically manipulated level is applied to the first and second control valves, thereby switching the same.
Description
본 발명은 유압회로에 관한 것으로, 보다 구체적으로 설명하면, 유압펌프로부터 유압실린더에 공급되는 작동유와 유압실린더로부터 작동유탱크로 귀환되는 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 from the hydraulic pump to the hydraulic cylinder and the hydraulic oil returned from the hydraulic cylinder to the hydraulic oil tank.
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) 및 파일럿펌프(2)가 엔진(미 도시됨)에 연결된다.As shown in FIG. 1, a variable displacement hydraulic pump (hereinafter referred to as a hydraulic pump) 1 and a pilot pump 2 are connected to an engine (not shown).
상기 유압펌프(1)로부터 공급되는 작동유에 의해 구동되는 유압실린더(3)가 상기 유압펌프(1)에 연결된다.A hydraulic cylinder 3 driven by hydraulic oil supplied from the hydraulic pump 1 is connected to the hydraulic pump 1.
절환시 상기 유압펌프(1)의 작동유를 상기 유압실린더(3)에 공급하거나, 상기 유압실린더(3)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시키는 컨트롤밸브(MCV)(4)가 상기 유압펌프(1)와 유압실린더(3) 사이의 유로에 설치된다.The control valve (MCV) (4) for supplying the hydraulic oil of the hydraulic pump (1) to the hydraulic cylinder (3) or the hydraulic oil discharged from the hydraulic cylinder (3) to the hydraulic oil tank (T) at the time of switching It is installed in the flow path between the hydraulic pump 1 and the hydraulic cylinder (3).
조작량에 대응되는 파일럿압력을 출력하는 조작레버(RCV)(미 도시됨)가 상기 파일럿펌프(2)와 컨트롤밸브(4) 사이의 유로에 설치된다.An operation lever RCV (not shown) for outputting a pilot pressure corresponding to the operation amount is provided in a flow path between the pilot pump 2 and the control valve 4.
전술한 구성에 의하면, 상기 조작레버를 조작하여 상기 파일럿펌프(2)로부터 공급되는 작동유를 조작량에 대응되게 변환시킨 파일럿압력(Pa)을 상기 컨트롤밸브(4)의 좌측 신호압포트에 인가시킬 경우 컨트롤밸브(4)의 스풀은 도면상, 우측방향으로 절환된다.According to the above-described configuration, when the pilot pressure Pa, which operates the operating lever and converts the hydraulic oil supplied from the pilot pump 2 to correspond to the operation amount, is applied to the left signal pressure port of the control valve 4. The spool of the control valve 4 is switched to the right direction in the drawing.
이로 인해, 상기 유압펌프(1)의 작동유는 컨트롤밸브(4)의 스풀을 통과하여 유압실린더(3)의 제1챔버(3a)에 공급되고, 상기 유압실린더(3)의 제2챔버(3b)로부터 배출되는 작동유는 상기 컨트롤밸브(4)의 스풀을 통과하여 작동유탱크(T)로 귀환된다. 따라서 상기 유압실린더(3)를 신장구동시킬 수 있다.Therefore, the hydraulic oil of the hydraulic pump 1 passes through the spool of the control valve 4 and is supplied to the first chamber 3a of the hydraulic cylinder 3, and the second chamber 3b of the hydraulic cylinder 3 is provided. The hydraulic oil discharged from) passes through the spool of the control valve 4 and is returned to the hydraulic oil tank (T). Therefore, the hydraulic cylinder 3 can be extended and driven.
이와 반대로, 상기 조작레버를 조작시 상기 파일럿펌프(2)로부터 공급되어 조작량에 대응되게 변환된 파일럿압력(Pb)을 상기 컨트롤밸브(4)의 우측 신호압포트에 인가시킬 경우 컨트롤밸브(4)의 스풀은 도면상, 좌측방향으로 절환된다.On the contrary, when the operation lever is operated, the pilot pressure Pb supplied from the pilot pump 2 and converted to correspond to the operation amount is applied to the right signal pressure port of the control valve 4. The spool of is switched to the left in the figure.
이로 인해, 상기 유압펌프(1)의 작동유는 컨트롤밸브(4)의 스풀을 통과하여 유압실린더(3)의 제2챔버(3b)에 공급되고, 상기 유압실린더(1)의 제1챔버(3a)로부터 배출되는 작동유는 상기 컨트롤밸브(4)의 스풀을 통과하여 작동유탱크(T)로 귀환된다. 따라서 상기 유압실린더(3)를 수축구동시킬 수 있다.Therefore, the hydraulic oil of the hydraulic pump 1 passes through the spool of the control valve 4 and is supplied to the second chamber 3b of the hydraulic cylinder 3, and the first chamber 3a of the hydraulic cylinder 1 is supplied. The hydraulic oil discharged from) passes through the spool of the control valve 4 and is returned to the hydraulic oil tank (T). Therefore, it is possible to shrink-drive the hydraulic cylinder 3.
이때, 상기 조작레버의 조작에 의해 상기 유압펌프(1)로부터 상기 유압실린더(3)에 공급되는 작동유와, 상기 유압실린더(3)로부터 배출되어 상기 작동유탱크(T)로 귀환되는 작동유의 량은 상기 조작레버의 조작량에 대응되게 절환되는 상기 컨트롤밸브(4)의 스풀의 개구면적에 따라 결정된다.At this time, the hydraulic oil supplied from the hydraulic pump 1 to the hydraulic cylinder 3 by the operation of the operation lever, and the amount of hydraulic oil discharged from the hydraulic cylinder 3 and returned to the hydraulic oil tank T is It is determined according to the opening area of the spool of the control valve 4 switched corresponding to the operation amount of the operation lever.
이는 상기 유압펌프(1)의 작동유를 상기 유압실린더(3)에 공급하기 위한 노치와, 상기 유압실린더(3)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시키는 노치(notch)가 상기 컨트롤밸브(4)의 스풀에 2개소씩 형성되어 있기 때문이다.The notch for supplying the hydraulic oil of the hydraulic pump 1 to the hydraulic cylinder 3 and the notch for returning the hydraulic oil discharged from the hydraulic cylinder 3 to the hydraulic oil tank T are the control valves. It is because it forms in two places in the spool of (4).
이로 인해, 상기 유압실린더(3)를 신장구동시키거나 수축구동시켜 작업하는 도중에 상기 유압실린더(3)에 발생되는 압력 또는 장비의 움직임에 따라 상기 유압펌프(1)의 작동유를 상기 유압실린더(3)에 공급하기 위한 컨트롤밸브(4)의 스풀 개구면적과, 상기 유압실린더(3)로부터 배출되는 작동유를 상기 작동유탱크(T)로 귀환하기 위한 컨트롤밸브(4)의 스풀 개구면적을 독립적으로 제어할 수 없게 된다.For this reason, the hydraulic oil of the hydraulic pump 1 is supplied to the hydraulic cylinder 3 according to the pressure generated in the hydraulic cylinder 3 or the movement of the equipment while the hydraulic cylinder 3 is extended or driven. Independent control of the spool opening area of the control valve (4) for supply to the control valve and the spool opening area of the control valve (4) for returning the hydraulic oil discharged from the hydraulic cylinder (3) to the hydraulic oil tank (T) You will not be able to.
즉, 상기 유압펌프(1)의 작동유를 상기 유압실린더(3)에 공급하기 위한 상기 컨트롤밸브(4)의 스풀의 개구면적과, 상기 유압실린더(3)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시키기 위한 컨트롤밸브(4)의 스풀의 개구면적이 상기 조작레버의 조작에 의해 상기 컨트롤밸브(4)에 인가되는 파일럿압력에 의해 종속적으로 제어되기 때문이다.That is, the opening area of the spool of the control valve 4 for supplying the hydraulic oil of the hydraulic pump 1 to the hydraulic cylinder 3, and the hydraulic oil discharged from the hydraulic cylinder 3 to the hydraulic oil tank (T). This is because the opening area of the spool of the control valve 4 for returning to the valve is controlled dependently by the pilot pressure applied to the control valve 4 by the operation of the operation lever.
따라서, 본 발명은 전술한 문제점을 해결하고자 하는 것으로, 유압실린더에 발생되는 압력에 따라 유압펌프의 작동유를 유압실린더에 공급하거나, 유압실린더로부터 배출되는 작동유를 작동유탱크로 귀환시키기 위한 컨트롤밸브를 이원화시켜 독립적으로 제어할 수 있는 건설기계용 유압회로를 제공하는 것을 목적으로 한다.Accordingly, the present invention is to solve the above-mentioned problems, dualizing the control valve for supplying the hydraulic oil of the hydraulic pump to the hydraulic cylinder or the hydraulic oil discharged from the hydraulic cylinder to the hydraulic oil tank in accordance with the pressure generated in the hydraulic cylinder It is an object of the present invention to provide a hydraulic circuit for construction machinery that can be controlled independently.
상기 및 기타 본 발명의 목적을 달성하기 위하여 본 발명의 일 실시예에 따르면, 가변용량형 유압펌프 및 파일럿펌프;According to an embodiment of the present invention to achieve the above and other objects of the present invention, a variable displacement hydraulic pump and a pilot pump;
상기 유압펌프로부터 공급되는 작동유에 의해 구동되는 유압실린더;A hydraulic cylinder driven by the hydraulic oil supplied from the hydraulic pump;
조작량에 대응되는 전기적신호를 출력하는 전기식 조작레버;An electric operation lever for outputting an electric signal corresponding to the operation amount;
상기 유압펌프와 유압실린더 사이의 유로에 설치되고, 절환시 상기 유압펌프의 작동유를 상기 유압실린더의 제1챔버에 공급하거나, 상기 유압실린더의 제1챔버로부터 배출되는 작동유를 작동유탱크로 귀환시키는 제1컨트롤밸브;Is installed in the flow path between the hydraulic pump and the hydraulic cylinder, supplying the hydraulic oil of the hydraulic pump to the first chamber of the hydraulic cylinder during switching, or the hydraulic oil discharged from the first chamber of the hydraulic cylinder to the hydraulic oil tank 1 control valve;
상기 유압펌프와 유압실린더 사이의 유로에 설치되고, 상기 제1컨트롤밸브와 동시에 절환시 상기 유압실린더의 제2챔버로부터 배출되는 작동유를 작동유탱크로 귀환시키거나, 상기 유압펌프의 작동유를 상기 유압실린더의 제2챔버에 공급하는 제2컨트롤밸브;Is installed in the flow path between the hydraulic pump and the hydraulic cylinder, the hydraulic oil discharged from the second chamber of the hydraulic cylinder when switching at the same time with the first control valve to return to the hydraulic oil tank, or the hydraulic oil of the hydraulic pump to the hydraulic cylinder A second control valve supplied to a second chamber of the second control valve;
상기 파일럿펌프와 상기 제1컨트롤밸브 사이의 유로와 상기 파일럿펌프와 상기 제2컨트롤밸브 사이의 유로에 설치되고, 상기 제1컨트롤밸브 및 제2컨트롤밸브의 스풀 개구면적을 독립적으로 제어하기 위해 상기 전기식 조작레버의 조작량에 대응되는 파일럿압력을 상기 제1컨트롤밸브 및 제2컨트롤밸브에 인가시켜 절환시키는 비례제어밸브를 구비하는 것을 특징으로 하는 건설기계용 유압회로를 제공한다.It is installed in the flow path between the pilot pump and the first control valve and the flow path between the pilot pump and the second control valve, to independently control the spool opening area of the first control valve and the second control valve Provided is a hydraulic circuit for a construction machine, characterized in that it comprises a proportional control valve for switching by applying a pilot pressure corresponding to the operation amount of the electric operation lever to the first control valve and the second control valve.
전술한 구성을 갖는 본 발명에 따르면, 유압실린더를 구동시켜 작업하는 도중에, 유압실린더에 발생되는 압력에 따라 유압펌프의 작동유를 유압실린더에 공급하거나, 유압실린더로부터 작동유탱크로 귀환되는 작동유를 제어하기 위한 컨트롤밸브를 이원화시켜 독립적으로 제어함에 따라, 유압실린더에 과다하게 압력 상승되는 것을 방지할 수 있고, 유압실린더에 공급되는 작동유 량을 조정하여 작업속도를 높일 수 있는 효과가 있다.According to the present invention having the above-described configuration, during the operation of driving the hydraulic cylinder, supplying the hydraulic oil of the hydraulic pump to the hydraulic cylinder in accordance with the pressure generated in the hydraulic cylinder, or to control the hydraulic oil returned from the hydraulic cylinder to the hydraulic oil tank By independently controlling the control valve for the dual, it is possible to prevent excessive pressure rise in the hydraulic cylinder, it is possible to increase the working speed by adjusting the operating flow rate supplied to the hydraulic cylinder.
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 바람직한 실시예에 따른 건설기계용 유압회로도이다.2 is a hydraulic circuit diagram for a construction machine according to a preferred embodiment of the present invention.
〈도면의 주요 부분에 대한 참조 부호의 설명〉<Explanation of reference numerals for the main parts of the drawings>
10; 가변용량형 유압펌프10; Variable displacement hydraulic pump
11; 파일럿펌프11; Pilot pump
12; 유압실린더12; Hydraulic cylinder
13; 전기식 조작레버(RCV)13; Electric control lever (RCV)
14; 제1컨트롤밸브(MCV)14; First Control Valve (MCV)
15; 제2컨트롤밸브(MCV)15; Second control valve (MCV)
16; 비례제어밸브(PPRV)16; Proportional control valve (PPRV)
17; 제1비례제어밸브17; First proportional control valve
18; 제2비례제어밸브18; 2nd proportional control valve
19; 제3비례제어밸브19; Third proportional control valve
20; 제4비례제어밸브20; Fourth proportional control 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 바람직한 실시예에 따른 건설기계용 유압회로도이다.2 is a hydraulic circuit diagram for a construction machine according to a preferred 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)(10) 및 파일럿펌프(11)가 엔진(미 도시됨)에 연결된다.A variable displacement hydraulic pump (hereinafter referred to as a hydraulic pump) 10 and a pilot pump 11 are connected to the engine (not shown).
상기 유압펌프(10)로부터 공급되는 작동유에 의해 구동되는 유압실린더(12)가 상기 유압펌프(10)에 연결된다.The hydraulic cylinder 12 driven by the hydraulic oil supplied from the hydraulic pump 10 is connected to the hydraulic pump 10.
전기식 조작레버(RCV)(13)의 조작에 의해 인가되는 파일럿압력에 의해 절환되는 경우 상기 유압펌프(10)의 작동유를 상기 유압실린더(12)의 제1챔버(12a)에 공급하거나, 상기 유압실린더(12)의 제1챔버(12a)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시키는 제1컨트롤밸브(MCV)(14)가 상기 유압펌프(10)와 유압실린더(12) 사이의 유로에 설치된다.When switching by the pilot pressure applied by the operation of the electric control lever (RCV) 13, supply the hydraulic oil of the hydraulic pump 10 to the first chamber 12a of the hydraulic cylinder 12, or the hydraulic pressure A first control valve (MCV) 14 for returning the hydraulic oil discharged from the first chamber 12a of the cylinder 12 to the hydraulic oil tank T is a flow path between the hydraulic pump 10 and the hydraulic cylinder 12. Is installed on.
상기 전기식 조작레버(13)의 조작에 의해 인가되는 파일럿압력에 의해 상기 제1컨트롤밸브(14)와 동시에 절환되는 경우 상기 유압실린더(12)의 제2챔버(12b)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시키거나, 상기 유압펌프(10)의 작동유를 상기 유압실린더(12)의 제2챔버(12b)에 공급하는 제2컨트롤밸브(MCV)(15)가 상기 유압펌프(10)와 유압실린더(12) 사이의 유로에 설치된다.The hydraulic oil discharged from the second chamber 12b of the hydraulic cylinder 12 when the hydraulic pressure switch 12 is simultaneously switched with the first control valve 14 by the pilot pressure applied by the operation of the electric operation lever 13. The second control valve (MCV) 15 for returning to (T) or supplying the hydraulic oil of the hydraulic pump 10 to the second chamber 12b of the hydraulic cylinder 12 is the hydraulic pump 10 And a flow path between the hydraulic cylinder 12.
상기 제1컨트롤밸브(14) 및 제2컨트롤밸브(15)의 스풀 개구면적(open area)을 독립적으로 제어하기 위해, 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되게 2차 파일럿압력으로 변환하여, 상기 제1컨트롤밸브(14) 및 제2컨트롤밸브(15)에 변환된 2차 파일럿압력을 인가시켜 절환시키는 비례제어밸브(16)가 상기 파일럿펌프(11)와 상기 제1컨트롤밸브(14) 사이의 유로 및 상기 파일럿펌프(11)와 상기 제2컨트롤밸브(15) 사이의 유로에 설치된다.In order to independently control the spool opening area of the first control valve 14 and the second control valve 15, the hydraulic oil supplied from the pilot pump 11 is transferred to the electric control lever 13. The pilot pump has a proportional control valve 16 that converts the secondary pilot pressure to correspond to the manipulated variable and applies the secondary pilot pressure to the first control valve 14 and the second control valve 15 to switch the pilot pressure. (11) and the flow path between the first control valve 14 and the flow path between the pilot pump 11 and the second control valve (15).
상기 비례제어밸브(PPRV;proportional pilot reducing valve)(16)는,The proportional pilot reducing valve (PPRV) 16,
상기 유압펌프(10)의 작동유를 상기 유압실린더(12)의 제1챔버(12a)에 공급할 경우, 상기 제1컨트롤밸브(14)의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제1컨트롤밸브(14)의 신호압포트에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제1비례제어밸브(17);When the hydraulic oil of the hydraulic pump 10 is supplied to the first chamber 12a of the hydraulic cylinder 12, it is supplied from the pilot pump 11 to control the spool opening area of the first control valve 14. A first proportional to convert the hydraulic oil to the secondary pilot pressure corresponding to the operation amount of the electric control lever 13, and to switch by applying the converted secondary pilot pressure to the signal pressure port of the first control valve 14; Control valve 17;
상기 유압실린더(12)의 제2챔버(12b)로부터 배출되는 작동유를 상기 작동유탱크(T)로 귀환시킬 경우, 상기 제2컨트롤밸브(15)의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제2컨트롤밸브(15)의 신호압포트에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제2비례제어밸브(18);When the hydraulic oil discharged from the second chamber 12b of the hydraulic cylinder 12 is returned to the hydraulic oil tank T, the pilot pump 11 to control the spool opening area of the second control valve 15. ) To convert the hydraulic oil supplied from the hydraulic pressure to the secondary pilot pressure corresponding to the operation amount of the electric control lever 13, and to switch by applying the converted secondary pilot pressure to the signal pressure port of the second control valve (15) A second proportional control valve 18;
상기 유압펌프(10)의 작동유를 상기 유압실린더(12)의 제2챔버(12b)에 공급할 경우, 상기 제2컨트롤밸브(15)의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제2컨트롤밸브(15)의 신호압포트에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제3비례제어밸브(19);When the hydraulic oil of the hydraulic pump 10 is supplied to the second chamber 12b of the hydraulic cylinder 12, it is supplied from the pilot pump 11 to control the spool opening area of the second control valve 15. A third proportion of converting the hydraulic fluid to the secondary pilot pressure corresponding to the operation amount of the electric control lever 13 and applying the converted secondary pilot pressure to the signal pressure port of the second control valve 15 for switching. Control valve 19;
상기 유압실린더(12)의 제1챔버(12a)로부터 배출되는 작동유를 상기 작동유탱크(T)로 귀환시킬 경우, 상기 제1컨트롤밸브(14)의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제1컨트롤밸브(14)의 신호압포트에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제4비례제어밸브(20)로 이루어진다.When the hydraulic oil discharged from the first chamber 12a of the hydraulic cylinder 12 is returned to the hydraulic oil tank T, the pilot pump 11 to control the spool opening area of the first control valve 14. ) To convert the hydraulic oil supplied from the hydraulic pressure to the secondary pilot pressure corresponding to the operation amount of the electric control lever 13, and to switch by applying the converted secondary pilot pressure to the signal pressure port of the first control valve (14) And a fourth proportional control valve 20.
상기 제1,2비례제어밸브(17,18) 및 제3,4비례제어밸브(19,20)는 상기 전기식조작레버(13)의 조작에 의한 전기적신호가 상기 제1,2,3,4비례제어밸브(17,18,19,20)에 인가되지않을 경우 상기 파일럿펌프(11)로부터 공급되는 작동유가 상기 제1,2컨트롤밸브(14,15)에 파일럿압력으로 인가되지않도록 차단하는 초기상태를 유지한다.The first and second proportional control valves 17 and 18 and the third and fourth proportional control valves 19 and 20 provide electrical signals generated by manipulation of the electric control lever 13. When not applied to the proportional control valves 17, 18, 19 and 20, the initial operation of blocking the hydraulic oil supplied from the pilot pump 11 from being applied to the first and second control valves 14 and 15 at the pilot pressure. Maintain state.
상기 유압실린더(12)는 굴삭기의 붐실린더, 아암실린더 및 버킷실린더 중 어느 하나이다.The hydraulic cylinder 12 is any one of the boom cylinder, the arm cylinder and the bucket cylinder of the excavator.
도면에는 미 도시되었으나, 상기 제1컨트롤밸브(14) 및 제2컨트롤밸브(15)의 스풀 개구면적은 상기 유압실린더(12)에 발생되는 압력의 크기 또는 장비의 움직임(machine motion)에 따라 조절될 수 있도록, 상기 제1컨트롤밸브(14)와 유압실린더(12) 사이의 유로 및 상기 제2컨트롤밸브(15)와 유압실린더(12) 사이의 유로에 설치되어 상기 유압실린더(12)의 제1챔버(12a) 및 제2챔버(12b)에 발생되는 압력을 감지하는 압력센서를 구비할 수 있다.Although not shown in the drawing, the opening area of the spool of the first control valve 14 and the second control valve 15 is adjusted according to the magnitude of the pressure generated in the hydraulic cylinder 12 or the machine motion. In order to be able to be, the flow path between the first control valve 14 and the hydraulic cylinder 12 and the flow path between the second control valve 15 and the hydraulic cylinder 12 is installed in the first It may be provided with a pressure sensor for detecting the pressure generated in the first chamber (12a) and the second chamber (12b).
전술한 구성에 따르면, 상기 유압실린더(12)의 신장구동을 먼저 설명한다.According to the above-described configuration, the extension drive of the hydraulic cylinder 12 will be described first.
상기 유압실린더(12)를 신장구동(일 예로서 굴삭기의 붐 업(boom up) 구동시킴을 말함)시키기 위해 상기 전기식 조작레버(13)를 조작함에 따른 전기적신호는 상기 제1비례제어밸브(17) 및 제2비례제어밸브(18)에 동시에 인가된다.The electrical signal resulting from operating the electric control lever 13 to drive the hydraulic cylinder 12 in an extension drive (for example, driving a boom up of an excavator) is the first proportional control valve 17. ) And the second proportional control valve 18 are applied simultaneously.
따라서, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호가 상기 제1비례제어밸브(17)에 인가되는 경우, 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되게 2차 파일럿압력으로 변환하여 상기 제1컨트롤밸브(14)의 우측 신호압포트에 변환된 2차 파일럿압력을 인가한다.Therefore, when the electric signal by the operation of the electric operation lever 13 is applied to the first proportional control valve 17, the operating amount of the electric operation lever 13 is supplied with the hydraulic oil supplied from the pilot pump 11. The secondary pilot pressure is converted to the secondary pilot pressure so that the secondary pilot pressure is converted to the right signal pressure port of the first control valve 14.
상기 제1컨트롤밸브(14)의 스풀이 도면상, 좌측방향으로 절환되므로 상기 유압펌프(10)의 작동유는 상기 제1컨트롤밸브(14)의 스풀을 통과하여 상기 유압실린더(12)의 제1챔버(12a)에 공급된다.Since the spool of the first control valve 14 is switched in the left direction in the drawing, the hydraulic oil of the hydraulic pump 10 passes through the spool of the first control valve 14 and thus the first of the hydraulic cylinder 12. It is supplied to the chamber 12a.
한편, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호가 상기 제2비례제어밸브(18)에 인가되는 경우, 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되게 2차 파일럿압력으로 변환하여 상기 제2컨트롤밸브(15)의 좌측 신호압포트에 변환된 2차 파일럿압력을 인가한다.On the other hand, when the electric signal by the operation of the electric operation lever 13 is applied to the second proportional control valve 18, the hydraulic oil supplied from the pilot pump 11 the operation amount of the electric operation lever 13 The secondary pilot pressure is converted to the secondary pilot pressure so that the secondary pilot pressure is converted to the left signal pressure port of the second control valve 15.
상기 제2컨트롤밸브(15)의 스풀이 도면상, 우측방향으로 절환되므로 상기 유압실린더(12)의 제2챔버(12b)로부터 배출되는 작동유는 상기 제2컨트롤밸브(15)의 스풀을 통과하여 상기 작동유탱크(T)로 귀환된다.Since the spool of the second control valve 15 is switched in the right direction in the drawing, the hydraulic oil discharged from the second chamber 12b of the hydraulic cylinder 12 passes through the spool of the second control valve 15. It returns to the said hydraulic oil tank (T).
따라서, 상기 유압실린더(12)를 신장구동시킬 수 있게 된다.Therefore, the hydraulic cylinder 12 can be extended and driven.
이하에서, 상기 유압실린더(12)의 수축구동을 설명한다.Hereinafter, the shrinkage driving of the hydraulic cylinder 12 will be described.
상기 유압실린더(12)를 수축구동(일 예로서 굴삭기의 붐 다운(boom down) 구동시킴을 말함)시키기 위해 상기 전기식 조작레버(13)를 조작함에 따른 전기적신호는 상기 제3비례제어밸브(19) 및 제4비례제어밸브(20)에 동시에 인가된다.The electrical signal generated by operating the electric control lever 13 to contract the hydraulic cylinder 12 (for example, to drive the boom down of the excavator) is the third proportional control valve 19. ) And the fourth proportional control valve 20 are applied simultaneously.
따라서, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호가 상기 제3비례제어밸브(19)에 인가되는 경우, 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되게 2차 파일럿압력으로 변환하여 상기 제2컨트롤밸브(15)의 우측 신호압포트에 변환된 2차 파일럿압력을 인가한다.Therefore, when the electric signal by the operation of the electric operation lever 13 is applied to the third proportional control valve 19, the operating amount of the electric operation lever 13 to the hydraulic oil supplied from the pilot pump (11). The secondary pilot pressure is converted to the secondary pilot pressure so as to correspond to the secondary pilot pressure and applied to the right signal pressure port of the second control valve 15.
상기 제2컨트롤밸브(15)의 스풀이 도면상, 좌측방향으로 절환되므로 상기 유압펌프(10)의 작동유는 상기 제2컨트롤밸브(15)의 스풀을 통과하여 상기 유압실린더(12)의 제2챔버(12b)에 공급된다.Since the spool of the second control valve 15 is switched in the left direction in the drawing, the hydraulic oil of the hydraulic pump 10 passes through the spool of the second control valve 15 so that the second of the hydraulic cylinder 12 It is supplied to the chamber 12b.
한편, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호가 상기 제4비례제어밸브(20)에 인가되는 경우, 상기 파일럿펌프(11)로부터 공급되는 작동유를 상기 전기식 조작레버(13)의 조작량에 대응되게 2차 파일럿압력으로 변환하여 상기 제1컨트롤밸브(14)의 좌측 신호압포트에 변환된 2차 파일럿압력을 인가한다.On the other hand, when the electric signal by the operation of the electric operation lever 13 is applied to the fourth proportional control valve 20, the operating amount of the electric operation lever 13 to the hydraulic oil supplied from the pilot pump 11 The secondary pilot pressure is converted to the secondary pilot pressure so that the secondary pilot pressure is converted to the left signal pressure port of the first control valve 14.
상기 제1컨트롤밸브(14)의 스풀이 도면상, 우측방향으로 절환되므로 상기 유압실린더(12)의 제1챔버(12a)로부터 배출되는 작동유는 상기 제1컨트롤밸브(14)의 스풀을 통과하여 상기 작동유탱크(T)로 귀환된다.Since the spool of the first control valve 14 is switched to the right in the drawing, the hydraulic oil discharged from the first chamber 12a of the hydraulic cylinder 12 passes through the spool of the first control valve 14. It returns to the said hydraulic oil tank (T).
따라서, 상기 유압실린더(12)를 수축구동시킬 수 있게 된다.Therefore, it is possible to shrink-drive the hydraulic cylinder 12.
전술한 바와 같이 상기 전기식 조작레버(13)를 조작하여 상기 제1,2비례제어밸브(17,18)의 절환에 의해 상기 제1,2컨트롤밸브(14,15)를 절환시켜 상기 유압실린더(12)를 신장구동시키거나, 상기 전기식 조작레버(13)를 조작하여 상기 제3,4비례제어밸브(19,20)의 절환에 의해 상기 제1,2컨트롤밸브(14,15)를 절환시켜 상기 유압실린더(12)를 수축구동시킬 수 있다.As described above, the electric control lever 13 is operated to switch the first and second control valves 14 and 15 by switching the first and second proportional control valves 17 and 18 so that the hydraulic cylinder ( 12) or the first and second control valves 14 and 15 by switching between the third and fourth proportional control valves 19 and 20 by operating the electric operation lever 13. The hydraulic cylinder 12 can be driven to shrink.
이때, 상기 제1,2컨트롤밸브(14,15)와 유압실린더(12) 사이의 유로에 설치된 압력센서(미 도시됨)에 의해 검출되는 유압실린더(12)에 발생되는 압력 또는 장비의 움직임에 의해 상기 제1,2컨트롤밸브(14,15)의 스풀 개구면적을 독립적으로 제어할 수 있다.At this time, the pressure or movement of the equipment generated by the hydraulic cylinder 12 detected by a pressure sensor (not shown) installed in the flow path between the first and second control valves 14 and 15 and the hydraulic cylinder 12. As a result, the spool opening areas of the first and second control valves 14 and 15 can be controlled independently.
즉, 상기 압력센서에 의해 상기 유압실린더(12)의 제1,2챔버(12a,12b)측에 발생되는 압력 검출신호가 미도시된 제어부(ECU)에 입력됨에 따라, 제어부에 의해 상기 전기식 조작레버(13)의 조작에 의해 상기 제1,2비례제어밸브 (17,18) 또는 상기 제3,4비례제어밸브(19,20)에 인가되는 전기적신호를 조절하게 된다.That is, as the pressure detection signal generated on the first and second chambers 12a and 12b of the hydraulic cylinder 12 by the pressure sensor is input to the control unit ECU not shown, the electric operation is performed by the control unit. By operating the lever 13, the electrical signals applied to the first and second proportional control valves 17 and 18 or the third and fourth proportional control valves 19 and 20 are adjusted.
이로 인해, 상기 전기식 조작레버(13)의 조작에 의해 상기 제1,2,3,4비례제어밸브(17,18,19,20)에 인가되는 전기적 신호를 조절함에 따라 상기 제1,2,3,4비례제어밸브(17,18,19,20)에서 상기 제1,2컨트롤밸브(14,15)에 인가되는 파일럿압력의 크기를 조절할 수 있다. 따라서 상기 제1,2컨트롤밸브(14,15)의 스풀의 개구면적을 독립적으로 제어할 수 있게 된다.Therefore, the first, second, third, and fourth proportional control valves 17, 18, 19, and 20 are controlled by controlling the electrical signals applied to the first, second, third, and fourth proportional control valves 13. The magnitude of the pilot pressure applied to the first and second control valves 14 and 15 may be adjusted in the 3, 4 proportional control valves 17, 18, 19, and 20. Therefore, the opening area of the spool of the first and second control valves 14 and 15 can be controlled independently.
즉, 상기 전기식 조작레버(13)의 조작에 의해 상기 제1,2컨트롤밸브(14,15)를 절환시켜 상기 유압펌프(10)의 작동유를 상기 유압실린더(12)에 공급하고 상기 유압실린더(12)로부터 배출되는 작동유를 상기 작동유탱크(T)로 귀환시킬 경우, 상기 유압실린더(12)에 발생되는 압력 정도에 따라 상기 전기식 조작레버(13)의 조작에 의한 상기 제1,2컨트롤밸브(14,15)의 스풀 개구면적을 다르게 제어할 수 있다.That is, the first and second control valves 14 and 15 are switched by the operation of the electric operation lever 13 to supply the hydraulic oil of the hydraulic pump 10 to the hydraulic cylinder 12 and the hydraulic cylinder ( When the hydraulic oil discharged from the 12 is returned to the hydraulic oil tank T, the first and second control valves by the operation of the electric operation lever 13 according to the pressure generated in the hydraulic cylinder 12 ( The spool opening area of 14, 15 can be controlled differently.
따라서, 상기 유압실린더(12)를 신장구동시키거나 또는 수축구동시킬 경우, 상기 유압펌프(10)로부터 상기 유압실린더(12)에 공급되는 작동유 량과, 상기 유압실린더(12)로부터 작동유탱크(T)로 귀환되는 작동유 량을 다르게 제어할 수 있게 된다.Therefore, when the hydraulic cylinder 12 is extended or driven, the hydraulic fluid is supplied from the hydraulic pump 10 to the hydraulic cylinder 12, and the hydraulic oil tank T from the hydraulic cylinder 12. It is possible to control the operating flow rate returned to) differently.
따라서, 본 발명의 일 실시예의 건설기계의 유압회로에 의하면, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호를 상기 제1,2비례제어밸브(17,18)에 동시에 인가시켜 상기 제1,2컨트롤밸브(14,15)를 절환시킴에 따라 상기 유압펌프(10)의 작동유를 상기 제1컨트롤밸브(14)를 통과시켜 유압실린더(12)의 제1챔버(12a)에 공급하고, 상기 유압실린더(12)의 제2챔버(12b)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시킬 수 있다. 따라서 상기 유압실린더(12)를 신장구동시킬 수 있다.Therefore, according to the hydraulic circuit of the construction machine according to the embodiment of the present invention, the electric signal by the operation of the electric operation lever 13 is simultaneously applied to the first and second proportional control valves 17 and 18 so that the first As the two control valves 14 and 15 are switched, the hydraulic oil of the hydraulic pump 10 passes through the first control valve 14 to be supplied to the first chamber 12a of the hydraulic cylinder 12. The hydraulic oil discharged from the second chamber 12b of the hydraulic cylinder 12 may be returned to the hydraulic oil tank T. Therefore, the hydraulic cylinder 12 can be extended and driven.
이와 반대로, 상기 전기식 조작레버(13)의 조작에 의한 전기적신호를 상기 제3,4비례제어밸브(19,20)에 동시에 인가시켜 상기 제1,2컨트롤밸브(14,15)를 절환시킴에 따라 상기 유압펌프(10)의 작동유를 상기 제2컨트롤밸브(15)를 통과시켜 유압실린더(12)의 제2챔버(12b)에 공급하고, 상기 유압실린더(12)의 제1챔버(12a)로부터 배출되는 작동유를 작동유탱크(T)로 귀환시킬 수 있다. 따라서 상기 유압실린더(12)를 수축구동시킬 수 있다.On the contrary, the first and second control valves 14 and 15 are switched by simultaneously applying electric signals generated by the operation of the electric control lever 13 to the third and fourth proportional control valves 19 and 20. Accordingly, the hydraulic oil of the hydraulic pump 10 passes through the second control valve 15 to be supplied to the second chamber 12b of the hydraulic cylinder 12, and the first chamber 12a of the hydraulic cylinder 12 is provided. The hydraulic oil discharged from the tank can be returned to the hydraulic oil tank (T). Therefore, the hydraulic cylinder 12 can be driven to shrink.
이때, 상기 유압실린더(12)에 발생되는 압력의 크기에 따라, 상기 전기식 조작레버(13)의 조작에 의해 상기 제1,2,3,4비례제어밸브(17,18,19,20)에 인가되는 전기적신호를 조절할 경우, 상기 제1,2,3,4비례제어밸브(17,18,19,20)에서 인가되는 파일럿압력에 의해 절환되는 제1,2컨트롤밸브(14)의 스풀의 개구면적을 독립적으로 제어할 수 있게 된다.At this time, according to the magnitude of the pressure generated in the hydraulic cylinder 12, by the operation of the electric control lever 13 to the first, second, third, fourth proportional control valve (17, 18, 19, 20) When adjusting the applied electrical signal, the spool of the first, second control valve 14, which is switched by the pilot pressure applied from the first, second, third, fourth proportional control valve 17, 18, 19, 20 The opening area can be controlled independently.
즉, 도 1과 같은 종래의 유압회로에서는, 상기 유압실린더(3)의 신축구동시 하나의 컨트롤밸브(4)(MCV)의 스풀 절환에 의해 유압펌프(1)로부터 유압실린더(3)에 공급되는 작동유 량과, 상기 유압실린더(3)로부터 작동유탱크(T)로 귀환되는 작동유 량을 조절하기 위해서는 메인 컨트롤밸브(MCV)에 다양한 우선밸브(priority valve) 또는 유량제어밸브와, 붐 다운측에 부스터밸브(booster valve) 등을 설치하게 된다.That is, in the conventional hydraulic circuit as shown in FIG. 1, the hydraulic cylinder 3 is supplied from the hydraulic pump 1 to the hydraulic cylinder 3 by spool switching of one control valve 4 (MCV) during expansion and contraction operation of the hydraulic cylinder 3. In order to adjust the working oil flow rate and the working oil flow rate returned from the hydraulic cylinder (3) to the hydraulic oil tank (T), various priority valves or flow control valves on the main control valve (MCV) and the boom down side Booster valves are installed.
이와 반면에, 도 2에 도시된 본 발명의 유압회로에서는 유압실린더(12)의 신축구동시 독립적으로 제어되는 제1,2컨트롤밸브(14,15)의 스풀 절환에 의해 유압펌프(10)로부터 유압실린더(12)에 공급되는 작동유 량과, 상기 유압실린더(12)로부터 작동유탱크(T)로 귀환되는 작동유 량을 다르게 제어할 수 있다.On the other hand, in the hydraulic circuit of the present invention shown in FIG. 2 from the hydraulic pump 10 by spool switching of the first and second control valves 14 and 15 independently controlled during expansion and contraction of the hydraulic cylinder 12. The hydraulic fluid supplied to the hydraulic cylinder 12 and the hydraulic fluid returned from the hydraulic cylinder 12 to the hydraulic oil tank T can be controlled differently.
한편, IMV(independent metering valve)가 구비되는 전자 유압밸브 시스템(미 도시됨)이 적용되는 장비는, 유압펌프의 공급유로에 설치되는 포펫(poppet)의 상단에 설치되는 전자비례밸브(proportional valve)를 제어함에 따라 포펫의 움직임을 제어하여 유압펌프로부터 유압실린더에 공급되는 유량을 제어할 수 있다. 상기 전자 유압밸브 시스템은 개폐 싸이클의 증가에 따른 충격으로 인해 포펫의 시트(seat)에 마모가 발생되어 누유되는 단점이 있다. 또한 시트의 마모로 인해 포펫의 제어 성능도 저하됨에 따라 포펫 만을 장착시킨 상태와, 포펫과 전자비례밸브를 조합시킨 전자 유압밸브 시스템의 성능이 상이하게 되므로 전자 유압밸브 시스템의 수정이 불가피하게 된다.On the other hand, equipment to which an electromagnetic hydraulic valve system (not shown) equipped with an independent metering valve (IMV) is applied is provided with a proportional valve installed on top of a poppet installed in a supply passage of a hydraulic pump. By controlling the control of the movement of the poppet can control the flow rate supplied from the hydraulic pump to the hydraulic cylinder. The electrohydraulic valve system has a disadvantage in that wear occurs in the seat of the poppet due to the impact of the opening / closing cycle. In addition, since the control performance of the poppet decreases due to the wear of the seat, the state of mounting the poppet alone and the performance of the electrohydraulic valve system combining the poppet and the electromagnetic proportional valve are different, thereby making it necessary to modify the electrohydraulic valve system.
이와 반면에, 본 발명의 유압회로에서는 상기 포펫의 시트에 발생되는 마모로 인한 누유와, 포펫과 전자비례밸브를 조합시킬 경우 발생되는 전자 유압밸브 시스템의 성능 저하되는 현상이 발생되지 않는다.On the other hand, in the hydraulic circuit of the present invention, leakage of oil due to abrasion generated on the seat of the poppet and the performance of the electrohydraulic valve system generated by combining the poppet and the electromagnetic proportional valve do not occur.
여기에서, 상술한 본 발명에서는 바람직한 실시예를 참조하여 설명하였지만, 해당 기술분야에서 숙련된 당업자는 하기의 특허청구범위에 기재된 본 발명의 사상및 영역으로부터 벗어나지 않는 범위 내에서 본 발명을 다양하게 수정 및 변경할 수 있음을 이해할 수 있을 것이다.Herein, while 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, 굴삭기와 같은 건설기계의 유압펌프로부터 유압실린더에 공급되는 작동유와 유압실린더로부터 작동유탱크로 귀환되는 작동유를 제어하는 컨트롤밸브를 이원화시켜 독립적으로 제어할 수 있는 효과가 있다.According to the present invention having the above-described configuration, the effect that can be independently controlled by dualizing the control valve for controlling the hydraulic oil supplied from the hydraulic pump of the construction machine such as an excavator to the hydraulic cylinder and the hydraulic oil returned from the hydraulic cylinder to the hydraulic oil tank There is.
Claims (4)
- 가변용량형 유압펌프 및 파일럿펌프;Variable displacement hydraulic pump and pilot pump;상기 유압펌프로부터 공급되는 작동유에 의해 구동되는 유압실린더;A hydraulic cylinder driven by the hydraulic oil supplied from the hydraulic pump;조작량에 대응되는 전기적신호를 출력하는 전기식 조작레버;An electric operation lever for outputting an electric signal corresponding to the operation amount;상기 유압펌프와 유압실린더 사이의 유로에 설치되고, 절환시 상기 유압펌프의 작동유를 상기 유압실린더의 제1챔버에 공급하거나, 상기 유압실린더의 제1챔버로부터 배출되는 작동유를 작동유탱크로 귀환시키는 제1컨트롤밸브;Is installed in the flow path between the hydraulic pump and the hydraulic cylinder, supplying the hydraulic oil of the hydraulic pump to the first chamber of the hydraulic cylinder during switching, or the hydraulic oil discharged from the first chamber of the hydraulic cylinder to the hydraulic oil tank 1 control valve;상기 유압펌프와 유압실린더 사이의 유로에 설치되고, 상기 제1컨트롤밸브와 동시에 절환시 상기 유압실린더의 제2챔버로부터 배출되는 작동유를 작동유탱크로 귀환시키거나, 상기 유압펌프의 작동유를 상기 유압실린더의 제2챔버에 공급하는 제2컨트롤밸브;Is installed in the flow path between the hydraulic pump and the hydraulic cylinder, the hydraulic oil discharged from the second chamber of the hydraulic cylinder when switching at the same time with the first control valve to return to the hydraulic oil tank, or the hydraulic oil of the hydraulic pump to the hydraulic cylinder A second control valve supplied to a second chamber of the second control valve;상기 파일럿펌프와 상기 제1컨트롤밸브 사이의 유로와 상기 파일럿펌프와 상기 제2컨트롤밸브 사이의 유로에 설치되고, 상기 제1컨트롤밸브 및 제2컨트롤밸브의 스풀 개구면적을 독립적으로 제어하기 위해 상기 전기식 조작레버의 조작량에 대응되는 파일럿압력을 상기 제1컨트롤밸브 및 제2컨트롤밸브에 인가시켜 절환시키는 비례제어밸브;를 구비하는 것을 특징으로 하는 건설기계용 유압회로.It is installed in the flow path between the pilot pump and the first control valve and the flow path between the pilot pump and the second control valve, to independently control the spool opening area of the first control valve and the second control valve And a proportional control valve for switching the pilot pressure corresponding to the operation amount of the electric operation lever to the first control valve and the second control valve.
- 제1항에 있어서, 상기 비례제어밸브는,According to claim 1, wherein the proportional control valve,상기 유압펌프의 작동유를 상기 유압실린더의 제1챔버에 공급할 경우, 상기 제1컨트롤밸브의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프로부터 공급되는 작동유를 상기 전기식 조작레버의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제1컨트롤밸브에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제1비례제어밸브;When the hydraulic oil of the hydraulic pump is supplied to the first chamber of the hydraulic cylinder, the hydraulic oil supplied from the pilot pump to control the spool opening area of the first control valve corresponds to the operation amount of the electric operation lever. A first proportional control valve that converts the pressure into a pressure and applies the second pilot pressure to the first control valve to switch the pressure;상기 유압실린더의 제2챔버로부터 배출되는 작동유를 상기 작동유탱크로 귀환시킬 경우, 상기 제2컨트롤밸브의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프로부터 공급되는 작동유를 상기 전기식 조작레버의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제2컨트롤밸브에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제2비례제어밸브;When the hydraulic oil discharged from the second chamber of the hydraulic cylinder is returned to the hydraulic oil tank, the hydraulic oil supplied from the pilot pump to control the spool opening area of the second control valve corresponds to the operation amount of the electric operation lever. A second proportional control valve converting the secondary pilot pressure and applying the converted secondary pilot pressure to the second control valve to switch the secondary pilot pressure;상기 유압펌프의 작동유를 상기 유압실린더의 제2챔버에 공급할 경우, 상기 제2컨트롤밸브의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프로부터 공급되는 작동유를 상기 전기식 조작레버의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제2컨트롤밸브에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제3비례제어밸브;When the hydraulic oil of the hydraulic pump is supplied to the second chamber of the hydraulic cylinder, the hydraulic pilot oil supplied from the pilot pump to control the spool opening area of the second control valve corresponds to the operation amount of the electric operation lever. A third proportional control valve that converts the pressure into a pressure and applies the second pilot pressure to the second control valve to switch the pressure;상기 유압실린더의 제1챔버로부터 배출되는 작동유를 상기 작동유탱크로 귀환시킬 경우, 상기 제1컨트롤밸브의 스풀 개구면적을 제어하기 위해 상기 파일럿펌프로부터 공급되는 작동유를 상기 전기식 조작레버의 조작량에 대응되는 2차 파일럿압력으로 변환시키고, 상기 제1컨트롤밸브에 변환된 2차 파일럿압력을 인가시켜 절환시키는 제4비례제어밸브;로 이루어지는 것을 특징으로 하는 건설기계용 유압회로.When the hydraulic oil discharged from the first chamber of the hydraulic cylinder is returned to the hydraulic oil tank, the hydraulic oil supplied from the pilot pump to control the spool opening area of the first control valve corresponds to the operation amount of the electric operation lever. And a fourth proportional control valve which converts the secondary pilot pressure and applies the secondary pilot pressure to the first control valve to switch the secondary pilot pressure.
- 제1항에 있어서, 상기 유압실린더는The method of claim 1, wherein the hydraulic cylinder굴삭기의 붐실린더, 아암실린더 및 버킷실린더 중 어느 하나인 것을 특징으로 하는 건설기계용 유압회로.Hydraulic circuit for a construction machine, characterized in that any one of the boom cylinder, arm cylinder and bucket cylinder of the excavator.
- 제1항에 있어서,The method of claim 1,상기 제1컨트롤밸브 및 제2컨트롤밸브의 스풀 개구면적은 상기 유압실린더에 발생되는 압력의 크기에 따라 조절될 수 있도록 상기 제1,2컨트롤밸브와 유압실린더 사이의 유로에 설치되어 상기 유압실린더의 제1,2챔버에 발생되는 압력을 감지하는 압력센서를 구비하는 것을 특징으로 하는 건설기계용 유압회로.The spool opening areas of the first control valve and the second control valve are installed in a flow path between the first and second control valves and the hydraulic cylinder to be adjusted according to the magnitude of the pressure generated in the hydraulic cylinder. Hydraulic circuit for a construction machine, characterized in that it comprises a pressure sensor for detecting the pressure generated in the first and second chambers.
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