KR100961433B1 - hydraulic system of construction equipment - Google Patents

hydraulic system of construction equipment Download PDF

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Publication number
KR100961433B1
KR100961433B1 KR1020080100107A KR20080100107A KR100961433B1 KR 100961433 B1 KR100961433 B1 KR 100961433B1 KR 1020080100107 A KR1020080100107 A KR 1020080100107A KR 20080100107 A KR20080100107 A KR 20080100107A KR 100961433 B1 KR100961433 B1 KR 100961433B1
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South Korea
Prior art keywords
hydraulic
control valve
hydraulic pump
center bypass
work device
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KR1020080100107A
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Korean (ko)
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KR20100041100A (en
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토시미치 이케다
이양구
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볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비
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Priority to KR1020080100107A priority Critical patent/KR100961433B1/en
Priority to EP09010569.3A priority patent/EP2157245B1/en
Priority to JP2009189831A priority patent/JP5564215B2/en
Priority to CN2009101629749A priority patent/CN101676495B/en
Priority to US12/545,653 priority patent/US8572957B2/en
Publication of KR20100041100A publication Critical patent/KR20100041100A/en
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Publication of KR100961433B1 publication Critical patent/KR100961433B1/en

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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
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
    • E02F9/2267—Valves or distributors
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60Y—INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
    • B60Y2200/00—Type of vehicle
    • B60Y2200/40—Special vehicles
    • B60Y2200/41—Construction vehicles, e.g. graders, excavators
    • B60Y2200/412—Excavators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps

Abstract

개시된 내용은, 굴삭기와 같은 건설장비에 적용되는 2개의 유압펌프를 사용하는 유압시스템에 추가되는 제3유압펌프의 작동유를 작업장치측에 합류시킴에 따라, 주행 직진을 간섭하지 않고 작업장치용 액츄에이터(붐실린더 등)의 구동속도를 증속시키며, 합류로 인한 압력 손실되는 것을 최소화할 수 있도록 한 것으로,Disclosed is that the actuator of the third hydraulic pump added to the hydraulic system using two hydraulic pumps applied to construction equipment such as an excavator to the working device side, so as not to interfere with the traveling straight line actuator To increase the driving speed of (boom cylinder, etc.), and to minimize the pressure loss due to confluence,

본 발명의 일 실시예에 의한 건설장비용 유압시스템은,Hydraulic system for construction equipment according to an embodiment of the present invention,

엔진에 연결되는 제1,2,3유압펌프와,First, second and third hydraulic pumps connected to the engine,

제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브와,A first control valve for driving provided in the center bypass passage of the first hydraulic pump for controlling the starting, stopping, and direction change of the left traveling motor;

주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브와,A first control valve for the work device, which is installed in the center bypass passage downstream of the first control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브와,A second control valve for driving provided in the center bypass passage of the second hydraulic pump for controlling starting, stopping, and direction change of the right traveling motor;

주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브와,A second control valve for the work device, which is installed in the center bypass passage downstream of the second control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제3유압펌프의 토출유로에 접속되고, 주행용 제1,2제어밸브의 하류측에서 제1,2유압펌프의 센터바이패스통로에 제1,2체크밸브를 통해 각각 접속되는 제1통로 와,A first passage connected to the discharge passage of the third hydraulic pump and connected to the center bypass passages of the first and second hydraulic pumps on the downstream side of the first and second control valves for driving through the first and second check valves, respectively; ,

제3유압펌프의 토출유로에 접속되고, 주행용 제1,2제어밸브의 하류측에서 제1,2유압펌프의 병렬라인에 제3,4체크밸브를 통해 각각 접속되는 제2통로를 포함한다.And a second passage connected to the discharge passage of the third hydraulic pump and connected to the parallel line of the first and second hydraulic pumps on the downstream side of the first and second control valves for travel, respectively, through the third and fourth check valves. .

굴삭기, 작업장치, 액츄에이터, 3펌프 구동형 유압시스템 Excavator, Work Tool, Actuator, Three Pump Driven Hydraulic System

Description

건설장비용 유압시스템{hydraulic system of construction equipment}Hydraulic system of construction equipment

본 발명은 굴삭기와 같은 건설장비에 적용되는 2개의 유압펌프를 사용하는 유압시스템에 제3유압펌프를 추가하여 해당 작업장치(붐, 아암, 버킷)의 구동속도를 증속시킬 수 있도록 한 건설장비용 유압시스템에 관한 것이다.The present invention is to add a third hydraulic pump to the hydraulic system using two hydraulic pumps applied to construction equipment such as excavators for construction equipment to increase the driving speed of the work device (boom, arm, bucket) It relates to a hydraulic system.

더욱 상세하게는, 2개의 유압펌프를 사용하는 굴삭기의 유압시스템에 추가되는 제3유압펌프의 작동유를 작업장치측에 합류시킴에 따라, 주행 직진을 간섭하지않고 작업장치용 액츄에이터(붐실린더 등)의 구동속도를 증속시키며, 합류로 인한 압력 손실되는 것을 최소화할 수 있도록 한 건설장비용 유압시스템에 관한 것이다.More specifically, by joining the hydraulic fluid of the third hydraulic pump added to the hydraulic system of the excavator using two hydraulic pumps to the work device side, the actuator for the work device (boom cylinder, etc.) without interfering with traveling straight. The hydraulic system for the construction equipment to increase the driving speed of the and to minimize the pressure loss due to the confluence.

도 1에 도시된 바와 같이, 일반적인 굴삭기는,As shown in Figure 1, a typical excavator,

하부 주행체(1)와,The lower traveling body 1,

하부 주행체(1) 상에 선회모터 등의 구동으로 인해 선회가능하게 탑재되는 상부선회체(2)와,An upper revolving body 2 rotatably mounted on the lower traveling body 1 by driving of a revolving motor, etc.,

상부 선회체(2) 상에 탑재되는 운전실캡(3) 및 엔진실(4)과,Cab cap 3 and engine compartment 4 mounted on the upper swing body 2,

상부 선회체(2)에 고정되고, 붐실린더(5)에 의해 구동되는 붐(6)과, 아암실린더(7)에 의해 구동되는 아암(8)과, 버킷실린더(9)에 의해 구동되는 버킷(10)을 포함하는 작업장치(11)와,A boom 6 fixed to the upper swinging structure 2 and driven by the boom cylinder 5, an arm 8 driven by the arm cylinder 7, and a bucket driven by the bucket cylinder 9. A work device 11 comprising a 10,

상부 선회체(1) 상에 장착되고, 작업시 장비의 균형을 유지하는 카운터웨이트(12)를 포함한다.It is mounted on the upper pivot 1 and includes a counterweight 12 to balance the equipment during operation.

도 2에 도시된 바와 같이, 종래 기술에 의한 건설장비용 유압시스템(2개의 유압펌프를 사용하는 굴삭기의 유압시스템)은,As shown in Figure 2, the hydraulic system for construction equipment according to the prior art (hydraulic system of an excavator using two hydraulic pumps),

엔진에 연결되는 가변용량형 제1,2유압펌프(50,51)와,Variable displacement first and second hydraulic pumps 50 and 51 connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56) 및 아암실린더(57) 의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 on the downstream side of the first control valve 54 for traveling, and is connected through the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder 57 First control valves 68, 58, and 59 for controlling the working oil supplied to the working device of

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65) 및 아암실린더(57)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸 브(66,67,76)를 포함한다.It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel, and is connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder 57 A second control valve (66, 67, 76) for the working device to control the hydraulic oil supplied to the working device of the).

따라서, 굴삭기를 주행하기 위하여 주행용 제1제어밸브(54)를 절환시 제1유압펌프(50)로부터 공급되는 작동유에 의해 좌측 주행모터(53)를 구동시키고, 주행용 제2제어밸브(62)를 절환시 제2유압펌프(51)로부터 공급되는 작동유에 의해 우측 주행모터(61)를 구동시킨다.Accordingly, when the driving first control valve 54 is switched to drive the excavator, the left driving motor 53 is driven by the hydraulic oil supplied from the first hydraulic pump 50, and the driving second control valve 62 is used. At the time of switching), the right driving motor 61 is driven by the hydraulic oil supplied from the second hydraulic pump 51.

즉, 동일한 용량의 제1,2유압펌프(50,51)로부터 토출되는 작동유에 의해 좌우측 주행모터(53,61)를 각각 구동시킴에 따라 직진 주행성을 확보할 수 있다.That is, as the left and right traveling motors 53 and 61 are driven by the hydraulic oil discharged from the first and second hydraulic pumps 50 and 51 of the same capacity, it is possible to secure the straight running property.

한편, 주행시 작업장치(붐을 조작하는 경우)를 동시에 구동시켜 복합작업을 수행하는 경우, 제1유압펌프(50)로부터 토출되는 작동유 일부는 주행용 제1제어밸브(54)를 통해 좌측 주행모터(53)에 공급되고, 동시에 제1유압펌프(50)의 작동유 일부는 병렬라인(55)을 통해 제어밸브(68)를 경유하여 붐실린더(64)에 공급된다.On the other hand, when the work device (when operating the boom) to drive at the same time to perform a composite work, a part of the hydraulic oil discharged from the first hydraulic pump 50 is left driving motor through the first control valve 54 for driving And a part of the hydraulic oil of the first hydraulic pump 50 is supplied to the boom cylinder 64 via the control valve 68 via the parallel line 55.

또한, 제2유압펌프(51)로부터 토출되는 작동유 일부는 주행용 제2제어밸브(62)를 통해 우측 주행모터(61)에 공급되고, 동시에 제2유압펌프(51)의 작동유 일부는 병렬라인(63)을 통해 제2제어밸브(66)를 경유하여 붐실린더(64)에 공급된다.In addition, a part of the hydraulic oil discharged from the second hydraulic pump 51 is supplied to the right driving motor 61 through the second control valve 62 for driving, and at the same time a part of the hydraulic oil of the second hydraulic pump 51 is parallel to the line. It is supplied to the boom cylinder 64 via the 2nd control valve 66 via 63. FIG.

즉, 동일한 용량을 갖는 2개의 유압펌프를 사용하는 유압시스템이 적용되는 굴삭기에서, 제1유압펌프(50)로부터 토출되는 작동유에 의해 좌측 주행모터(53)와 작업장치(붐실린더(64) 등)를 구동시키고, 제2유압펌프(51)로부터 토출되는 작동유에 의해 우측 주행모터(61)와 작업장치(붐실린더(64) 등)를 각각 구동시킴에 따라, 주행과 작업장치를 동시에 구동시키는 복합작업시 장비는 직진 주행할 수 있다.That is, in an excavator to which a hydraulic system using two hydraulic pumps having the same capacity is applied, the left traveling motor 53 and the work device (boom cylinder 64, etc.) are driven by the hydraulic oil discharged from the first hydraulic pump 50. ) And drive the right traveling motor 61 and the work device (such as the boom cylinder 64) by the hydraulic oil discharged from the second hydraulic pump 51, thereby simultaneously driving the travel and the work device. In complex operations, the machine can travel straight.

한편, 작업조건에 따라 부하가 크게 발생되는 작업을 하는 경우 대형 굴삭기를 사용하게 된다. 이때 대형 굴삭기에 요구되는 용량의 유압펌프, 제어밸브, 액츄에이터 등을 장착하여 사용하게 되는데, 특히 굴삭기에 대용량의 유압펌프를 사용할 수 없는 경우(즉 대용량의 유압펌프 구입이 곤란하거나 가격이 고가여서 사용할 수 없는 경우) 제3유압펌프를 추가로 설치하여 사용하게 된다.On the other hand, when working with a large load depending on the working conditions to use a large excavator. At this time, the hydraulic pump, control valve, actuator, etc. of the capacity required for large excavators are installed and used.In particular, when a large capacity hydraulic pump cannot be used for the excavator (that is, it is difficult to purchase a large capacity hydraulic pump or is expensive. If it is not possible, additional 3rd hydraulic pump will be installed.

도 3에 도시된 바와 같이, 종래의 다른 기술에 의한 건설장비용 유압시스템(3개의 유압펌프를 사용하는 굴삭기의 유압시스템)은,As shown in Figure 3, the hydraulic system for construction equipment according to another conventional technique (hydraulic system of an excavator using three hydraulic pumps),

엔진에 연결되는 가변용량형 제1,2유압펌프(50,51)와,Variable displacement first and second hydraulic pumps 50 and 51 connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56) 및 아암실린더(57) 의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 on the downstream side of the first control valve 54 for traveling, and is connected through the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder 57 First control valves 68, 58, and 59 for controlling the working oil supplied to the working device of

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65) 및 아암실린더(57)등의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸 브(66,67,76)와,It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel, and is connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder 57 Second control valves 66, 67, and 76 for the work device for controlling the hydraulic oil supplied to the work device, respectively;

제2유압펌프(51)의 상류측 센터바이패스통로(60) 및 병렬라인(63)에 각각 연결되고, 작업장치용 유압실린더(붐실린더 등)에 작동유 공급량을 증대시켜 작업장치의 구동속도를 증속시키도록 사용하는 가변용량형 제3유압펌프(69)를 포함한다.It is connected to the center bypass passage 60 and the parallel line 63 upstream of the second hydraulic pump 51, respectively, and increases the operating oil supply amount to the hydraulic cylinder (boom cylinder, etc.) for the working device to increase the driving speed of the working device. And a variable displacement third hydraulic pump 69 used to increase the speed.

이때, 작업장치의 해당 액츄에이터를 증속시키도록 작동유를 추가 공급하는 제3유압펌프(69)를 제외한 구성은, 도 2에 도시된 구성과 실질적으로 동일하게 적용되므로 이들의 상세한 설명은 생략하고, 중복되는 도면부호는 동일하게 표기한다.At this time, the configuration except for the third hydraulic pump 69 for additionally supplying the hydraulic oil to increase the corresponding actuator of the work device is substantially the same as the configuration shown in Figure 2, so the detailed description thereof will be omitted, overlapping Reference numerals are the same.

전술한 제3유압펌프(69)로부터 공급되는 작동유에 의해 제2유압펌프(51)측 해당 작업장치(붐실린더(64))의 구동속도를 증속시키는 경우, 제3유압펌프(69)로부터 토출되는 작동유 일부가 주행모터(61)에도 공급된다. 이로 인해 작업장치와 주행장치측에 발생되는 부하압력 차이로 인해 작동유 공급량이 언밸런싱되므로, 직진 주행성을 확보할 수 없는 문제점을 갖는다.When the driving speed of the work device (boom cylinder 64) on the second hydraulic pump 51 side is increased by the hydraulic oil supplied from the third hydraulic pump 69 described above, it is discharged from the third hydraulic pump 69. A part of the hydraulic oil to be supplied is also supplied to the driving motor 61. As a result, since the hydraulic oil supply amount is unbalanced due to the difference in the load pressure generated on the work device and the traveling device side, there is a problem in that it is impossible to secure straight running.

도 4에 도시된 바와 같이, 종래의 또 다른 기술에 의한 건설장비용 유압시스템(3개의 유압펌프를 사용하는 굴삭기의 유압시스템)은,As shown in Figure 4, the hydraulic system for construction equipment according to another conventional technique (hydraulic system of an excavator using three hydraulic pumps),

엔진에 연결되는 가변용량형 가변용량형 제1,2유압펌프(50,51)와,Variable displacement variable displacement first and second hydraulic pumps 50 and 51 connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병 렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56) 및 아암실린더(57) 의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 to the downstream side of the first control valve 54 for travel, and is connected via the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder ( First control valves 68, 58 and 59 for the working device which respectively control the hydraulic oil supplied to the working device of

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65) 및 아암실린더(57)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브(66,67,76)와,It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel, and is connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder 57 Second control valves 66, 67, and 76 for the work device for controlling the hydraulic oil supplied to the work device of

주행용 제2제어밸브(62)의 하류측에서 병렬라인(63)에 토출유로(71)가 연결되고, 토출유로(71)에서 분기된 분기유로(70)를 통해 주행용 제2제어밸브(62)의 하류측 센터바이패스통로(60)에 연결되는 가변용량형 제3유압펌프(69)를 포함한다.On the downstream side of the traveling second control valve 62, the discharge flow path 71 is connected to the parallel line 63, and the traveling second control valve is driven through the branch flow path 70 branched from the discharge flow path 71. A variable displacement third hydraulic pump 69 connected to the downstream center bypass passage 60;

이때, 주행시 작업장치를 동시에 구동시켜 복합작업을 수행하는 경우, 주행 직진성을 확보할 수 있고, 작업장치의 해당 액츄에이터를 증속시키도록 작동유를 추가 공급하는 제3유압펌프(69)를 제외한 구성은, 도 3에 도시된 구성과 실질적으로 동일하게 적용되므로 이들의 상세한 설명은 생략하고, 중복되는 도면부호는 동일하게 표기한다.At this time, in the case of carrying out a complex operation by driving the work device at the same time when driving, it is possible to secure driving straightness, except for the configuration of the third hydraulic pump 69 for additionally supplying hydraulic oil to increase the corresponding actuator of the work device, Since they are applied in substantially the same manner as the configuration shown in FIG.

전술한 제3유압펌프(69)로부터 토출되는 작동유는 토출유로(71)에서 분기된 분기유로(70)에 의해 주행용 제2제어밸브(62)를 경유한 센터바이패스통로(60)의 작동유와 합류된 후, 토출유로(71)에 설치된 체크밸브(73)를 경유하여 작업장치용 제 2제어밸브(66)의 입력포트에 접속된다.The hydraulic fluid discharged from the above-mentioned third hydraulic pump 69 is the hydraulic fluid of the center bypass passage 60 via the second control valve 62 for travel by the branch passage 70 branched from the discharge passage 71. And is connected to the input port of the second control valve 66 for the working device via the check valve 73 provided in the discharge passage 71.

따라서, 붐을 조작하기 위하여 제2제어밸브(66)를 절환시킴에 따라 센터바이패스통로(60)는 닫힌다. 이로 인해 제2유압펌프(51)로부터 토출되는 작동유는 병렬라인(63)을 통해 제2제어밸브(66)의 입력포트에 유입된다.Accordingly, the center bypass passage 60 is closed by switching the second control valve 66 to operate the boom. As a result, the hydraulic oil discharged from the second hydraulic pump 51 flows into the input port of the second control valve 66 through the parallel line 63.

이때, 제3유압펌프(69)로부터의 작동유는 제2유압펌프(51)로부터 공급되는 작동유와 합류된다(제2제어밸브(66)의 절환으로 인해 분기유로(70)는 단힌상태임). 또한 제2제어밸브(66)의 출력포트에서는 제1제어밸브(68)의 절환으로 인해 제1유압펌프(50)로부터 공급되는 작동유와 합류된다.At this time, the hydraulic oil from the third hydraulic pump 69 is joined with the hydraulic oil supplied from the second hydraulic pump 51 (the branch flow path 70 is closed due to the switching of the second control valve 66). In addition, the output port of the second control valve 66 joins the hydraulic oil supplied from the first hydraulic pump 50 due to the switching of the first control valve 68.

따라서, 붐실린더(64)는 제1,2,3유압펌프(50,51,69)로부터 공급되는 작동유에 의해 구동되므로, 이의 구동속도를 증속시킬 수 있다.Therefore, since the boom cylinder 64 is driven by the hydraulic oil supplied from the first, second and third hydraulic pumps 50, 51 and 69, it is possible to increase the driving speed thereof.

한편, 버킷실린더(65)의 구동을 제어하는 제2제어밸브(67) 및 아암실린더(57)의 구동을 제어하는 제어밸브(76)가 제2제어밸브(66)의 하류측으로 센터바이패스통로(60)에 설치되어 병렬라인(63)을 통해 각각 연결된다. 이로 인해 버킷실린더(65)와 아암실린더(57)를 구동시 붐실린더(64)와 동일한 기능을 수행할 수 있다.On the other hand, the second control valve 67 for controlling the drive of the bucket cylinder 65 and the control valve 76 for controlling the drive of the arm cylinder 57 are located in the center bypass passage downstream of the second control valve 66. Installed in the 60 is connected via a parallel line 63, respectively. Thus, when driving the bucket cylinder 65 and the arm cylinder 57 can perform the same function as the boom cylinder (64).

한편, 버킷실린더(65)와 아암실린더(57)는 병렬라인(63)을 통해 서로 연결되므로, 이들을 동시에 구동시키는 경우에도 제3유압펌프(69)로부터 토출되는 작동유를 보충받을 수 있다.On the other hand, since the bucket cylinder 65 and the arm cylinder 57 are connected to each other through the parallel line 63, even when driving them at the same time, the hydraulic oil discharged from the third hydraulic pump 69 can be replenished.

한편, 붐실린더(64)의 조작중, 주행장치를 구동시켜 복합작업을 수행하는 경우, 제2유압펌프(51)측 병렬라인(63)의 상류측에 설치된 체크밸브(72)에 의해 붐실린더(64)에 공급되는 작동유가 주행용 제2제어밸브(62)에 공급되는 것을 방지할 수 있다.On the other hand, when the boom cylinder 64 is operated to drive a traveling device to perform a compound operation, the boom cylinder is provided by a check valve 72 provided upstream of the parallel line 63 on the second hydraulic pump 51 side. It is possible to prevent the hydraulic oil supplied to the 64 from being supplied to the traveling second control valve 62.

따라서, 작업장치와 주행장치를 동시에 조작하는 경우에도 작업장치측에 공급되는 작동유가 주행장치의 주행속도에 영향을 주지않아 직진 주행할 수 있다.Therefore, even when operating the work device and the travel device at the same time, the hydraulic oil supplied to the work device side can travel straight without affecting the travel speed of the travel device.

한편, 제3유압펌프(69)로부터 공급되는 작동유에 의해 직진 주행을 간섭하지않고 해당 작업장치의 구동속도를 증속시킬 경우, 작동유를 합류시킨 쪽의 제어밸브(일 예로서 제2제어밸브(66)를 말함)에는 합류로 인한 압력 손실이 커지게 된다. 이로 인해 에너지 손실으로 인한 연료 소비량이 증가되는 문제점을 갖는다.On the other hand, when increasing the driving speed of the work device without interfering with the straight running by the hydraulic oil supplied from the third hydraulic pump 69, the control valve on the side of the hydraulic oil (for example, the second control valve 66 ) Increases the pressure loss due to confluence. As a result, fuel consumption due to energy loss is increased.

본 발명의 실시예는, 2개의 유압펌프를 사용하는 유압시스템이 적용되는 굴삭기의 작업장치를 구동시, 추가된 제3유압펌프의 작동유를 작업장치측에 합류시킴에 따라, 주행 직진성을 확보하면서 작업장치의 해당 액츄에이터의 구동속도를 증속시켜 작업성을 향상시킬 수 있도록 한 건설장비용 유압시스템과 관련된다.The embodiment of the present invention, while driving the working device of the excavator to which the hydraulic system using two hydraulic pumps is applied, by joining the hydraulic fluid of the third hydraulic pump added to the working device side, while ensuring the traveling straightness It is related to the hydraulic system for construction equipment, which can improve the workability by increasing the driving speed of the corresponding actuator of the work equipment.

본 발명의 실시예는, 추가되는 제3유압펌프로부터의 작동유를 작업장치측에 합류시 발생되는 압력 손실을 최소화하여 연료 소비량을 줄일 수 있도록 한 건설장비용 유압시스템과 관련된다.Embodiments of the present invention relate to a hydraulic system for construction equipment that enables to reduce the fuel consumption by minimizing the pressure loss generated when the hydraulic oil from the third hydraulic pump to be added to the work device side.

본 발명의 일 실시예에 의한 건설장비용 유압시스템은,Hydraulic system for construction equipment according to an embodiment of the present invention,

엔진에 연결되는 제1,2,3유압펌프와,First, second and third hydraulic pumps connected to the engine,

제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브와,A first control valve for driving provided in the center bypass passage of the first hydraulic pump for controlling the starting, stopping, and direction change of the left traveling motor;

주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브와,A first control valve for the work device, which is installed in the center bypass passage downstream of the first control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브와,A second control valve for driving provided in the center bypass passage of the second hydraulic pump for controlling starting, stopping, and direction change of the right traveling motor;

주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브와,A second control valve for the work device, which is installed in the center bypass passage downstream of the second control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제3유압펌프의 토출유로에 접속되고, 주행용 제1,2제어밸브의 하류측에서 제1,2유압펌프의 센터바이패스통로에 제1,2체크밸브를 통해 각각 접속되는 제1통로와,A first passage connected to the discharge passage of the third hydraulic pump and connected to the center bypass passages of the first and second hydraulic pumps on the downstream side of the driving first and second control valves, respectively, through the first and second check valves; ,

제3유압펌프의 토출유로에 접속되고, 주행용 제1,2제어밸브의 하류측에서 제1,2유압펌프의 병렬라인에 제3,4체크밸브를 통해 각각 접속되는 제2통로를 포함한다.And a second passage connected to the discharge passage of the third hydraulic pump and connected to the parallel line of the first and second hydraulic pumps on the downstream side of the first and second control valves for travel, respectively, through the third and fourth check valves. .

본 발명의 다른 실시예에 의한 건설장비용 유압시스템은,Hydraulic system for construction equipment according to another embodiment of the present invention,

엔진에 연결되는 제1,2,3유압펌프와,First, second and third hydraulic pumps connected to the engine,

제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브와,A first control valve for driving provided in the center bypass passage of the first hydraulic pump for controlling the starting, stopping, and direction change of the left traveling motor;

주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브와,A first control valve for the work device, which is installed in the center bypass passage downstream of the first control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브와,A second control valve for driving provided in the center bypass passage of the second hydraulic pump for controlling starting, stopping, and direction change of the right traveling motor;

주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브와,A second control valve for the work device, which is installed in the center bypass passage downstream of the second control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제3유압펌프의 토출유로에 접속되고, 작업장치용 제1,2제어밸브중 최하류측 제어밸브의 입력포트에 제1,2체크밸브를 통해 각각 접속되는 제1통로와,A first passage connected to the discharge flow path of the third hydraulic pump and connected to the input port of the downstreammost control valve among the first and second control valves for the working device through the first and second check valves,

제3유압펌프의 토출유로에 접속되고, 제1,2유압펌프의 병렬라인 최하류측에 제3,4체크밸브를 통해 각각 접속되는 제2통로를 포함한다.And a second passage connected to the discharge passage of the third hydraulic pump and connected to the downstream of the parallel lines of the first and second hydraulic pumps via the third and fourth check valves, respectively.

본 발명의 또 다른 실시예에 의한 건설장비용 유압시스템은,Hydraulic system for construction equipment according to another embodiment of the present invention,

엔진에 연결되는 제1,2,3유압펌프와,First, second and third hydraulic pumps connected to the engine,

제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브와,A first control valve for driving provided in the center bypass passage of the first hydraulic pump for controlling the starting, stopping, and direction change of the left traveling motor;

주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브와,A first control valve for the work device, which is installed in the center bypass passage downstream of the first control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브와,A second control valve for driving provided in the center bypass passage of the second hydraulic pump for controlling starting, stopping, and direction change of the right traveling motor;

주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브와,A second control valve for the work device, which is installed in the center bypass passage downstream of the second control valve for travel, is connected via a parallel line, respectively, and controls the hydraulic oil supplied to the work device;

제3유압펌프의 토출유로에 접속되고, 주행용 제1,2제어밸브의 하류측에서 제 1,2유압펌프의 병렬라인에 제3,4체크밸브를 통해 각각 접속되는 제2통로와,A second passage connected to the discharge passage of the third hydraulic pump and connected to the parallel lines of the first and second hydraulic pumps on the downstream side of the first and second control valves for travel, respectively, through the third and fourth check valves;

제3유압펌프의 토출유로에 설치되고, 작업장치를 조작시 절환되어 제3유압펌프로부터의 작동유를 제1,2유압펌프의 병렬라인에 각각 공급하는 언로드밸브를 포함한다.And an unload valve installed in the discharge flow path of the third hydraulic pump and switched when the working device is operated to supply hydraulic oil from the third hydraulic pump to the parallel lines of the first and second hydraulic pumps, respectively.

바람직한 실시예에 의하면, 전술한 제1유압펌프의 병렬라인의 상류측에 설치되고, 제1유압펌프측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브와,According to a preferred embodiment, it is provided on the upstream side of the parallel line of the above-mentioned first hydraulic pump, and the hydraulic oil is supplied from the working device side to the traveling device side during the compound work for simultaneously driving the first hydraulic pump side working device and the traveling device. Check valve for preventing backflow,

제2유압펌프의 병렬라인의 상류측에 설치되고, 제2유압펌프측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브를 포함한다.It is installed on the upstream side of the parallel line of the second hydraulic pump, and includes a check valve for preventing the flow of hydraulic oil from the working device side to the traveling device side in the composite work for driving the second hydraulic pump side working device and the traveling device at the same time. do.

전술한 바와 같이, 본 발명의 실시예에 의한 건설장비용 유압시스템은 아래와 같은 이점을 갖는다.As described above, the hydraulic system for construction equipment according to an embodiment of the present invention has the following advantages.

2개의 유압펌프를 사용하는 유압시스템이 적용되는 굴삭기의 작업장치를 구동시, 추가된 제3유압펌프의 작동유를 작업장치측에 합류시킴에 따라, 주행 직진성을 확보하면서 작업장치의 해당 액츄에이터의 구동속도를 증속시켜 작업성 및 신뢰성을 향상시킬 수 있다.When driving the working device of the excavator to which the hydraulic system using two hydraulic pumps is applied, the operating oil of the third hydraulic pump is added to the working device side, thereby driving the corresponding actuator of the working device while ensuring driving straightness. The speed can be increased to improve workability and reliability.

또한, 추가되는 제3유압펌프로부터의 작동유를 작업장치측에 합류시 발생되 는 압력 손실을 최소화함에 따라 에너지 손실로 인한 연료 소비량을 줄일 수 있다.In addition, it is possible to reduce the fuel consumption due to energy loss by minimizing the pressure loss generated when the hydraulic oil from the additional third hydraulic pump is joined to the work device side.

이하, 본 발명의 바람직한 실시예를 첨부된 도면을 참조하여 설명하되, 이는 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자가 발명을 용이하게 실시할 수 있을 정도로 상세하게 설명하기 위한 것이지, 이로 인해 본 발명의 기술적인 사상 및 범주가 한정되는 것을 의미하지는 않는 것이다.Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to describe in detail enough to enable those skilled in the art to easily practice the invention, and therefore It does not mean that the technical spirit and scope of the present invention is limited.

도 5에 도시된 바와 같이, 본 발명의 일 실시예에 의한 건설장비용 유압시스템(3개의 유압펌프를 사용하는 유압시스템)은,As shown in Figure 5, the hydraulic system for construction equipment (hydraulic system using three hydraulic pumps) according to an embodiment of the present invention,

엔진에 연결되는 가변용량형 제1,2,3유압펌프(50,51,69)와,Variable displacement first, second, and third hydraulic pumps (50, 51, 69) connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56) 및 아암실린더(57) 의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 on the downstream side of the first control valve 54 for traveling, and is connected through the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder 57 First control valves 68, 58, and 59 for controlling the working oil supplied to the working device of

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병 렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65) 및 아암실린더(57)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브(66,67,76)와,It is installed in the center bypass passage 60 on the downstream side of the second control valve 62 for travel, and is connected through the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder ( Second control valves 66, 67, and 76 for the working device, respectively, for controlling the hydraulic oil supplied to the working device of the working device;

제3유압펌프(69)의 토출유로(80)에 접속되고, 주행용 제1,2제어밸브(54,62)의 하류측에서 제1,2유압펌프(50,51)의 센터바이패스통로(52,60)에 제1,2체크밸브(82,83)를 통해 각각 접속되는 제1통로(84)와,The center bypass passage of the first and second hydraulic pumps 50 and 51 is connected to the discharge passage 80 of the third hydraulic pump 69 and downstream from the first and second control valves 54 and 62 for travel. A first passage 84 connected to the first and second check valves 82 and 83 to 52 and 60, respectively;

제3유압펌프(69)의 토출유로(80)에 접속되고, 주행용 제1,2제어밸브(54,62)의 하류측에서 제1,2유압펌프(50,51)의 병렬라인(55,63)에 제3,4체크밸브(85,86)를 통해 각각 접속되는 제2통로(87)를 포함한다.A parallel line 55 of the first and second hydraulic pumps 50 and 51 is connected to the discharge passage 80 of the third hydraulic pump 69 and downstream from the first and second control valves 54 and 62 for travel. And 63, second passages 87 connected through third and fourth check valves 85 and 86, respectively.

이때, 제1유압펌프(50)의 병렬라인(55)의 상류측에 설치되고, 제1유압펌프(50)측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브(81)와,At this time, the hydraulic fluid is installed on the upstream side of the parallel line 55 of the first hydraulic pump 50, and the working oil from the working apparatus side to the traveling apparatus side during the compound work for simultaneously driving the working apparatus and the traveling apparatus at the first hydraulic pump 50 side. A check valve for preventing backflow (81) to block the supply;

제2유압펌프(51)의 병렬라인(63)의 상류측에 설치되고, 제2유압펌프(51)측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브(72)를 포함한다.It is installed on the upstream side of the parallel line 63 of the second hydraulic pump 51, and the hydraulic fluid is supplied from the working apparatus side to the traveling apparatus side during the compound work for simultaneously driving the working apparatus and the traveling apparatus on the second hydraulic pump 51 side. And a check valve 72 for preventing backflow.

이때, 제3유압펌프(69)의 토출유로(80)에 각각 접속되고, 제3유압펌프(69)로부터의 작동유를 제1유압펌프(50)의 작업장치 또는 제2유압펌(51)의 작업장치에 합류시키는 제1통로(84) 및 제2통로(87)를 제외한 구성은, 도 4에 도시된 종래의 유압시스템의 구성과 실질적으로 동일하게 적용되므로 이들의 상세한 설명은 생략하고, 중복되는 도면부호는 동일하게 표기한다.At this time, the hydraulic oil from the third hydraulic pump 69 is connected to the discharge flow path 80 of the third hydraulic pump 69, and the working device of the first hydraulic pump 50 or the second hydraulic pump 51 The configuration except for the first passage 84 and the second passage 87 joining the work device is substantially the same as the configuration of the conventional hydraulic system shown in FIG. 4, and thus, detailed description thereof will be omitted. Reference numerals are the same.

이하에서, 본 발명의 일 실시예에 의한 건설장비용 유압시스템의 사용예를 첨부된 도면을 참조하여 상세하게 설명한다.Hereinafter, with reference to the accompanying drawings an example of the use of the hydraulic system for construction equipment according to an embodiment of the present invention will be described in detail.

붐을 구동시키도록 붐실린더(64)를 단독으로 조작하는 경우를 설명한다.The case where the boom cylinder 64 is operated alone to drive the boom will be described.

도 5에 도시된 바와 같이, 작업장치용 제2제어밸브(66)를 절환시킴에 따라 제2유압펌프(51)측 센터바이패스통로(60)는 닫힌다. 이로 인해 제2유압펌프(51)로부터 토출되는 작동유는 병렬라인(63) 및 제2제어밸브(66)를 통과하여 붐실린더(64)에 공급된다. 즉 붐실린더(64)는 제2유압펌프(51)로부터의 작동유에 의해 구동된다.As shown in FIG. 5, as the second control valve 66 for the work device is switched, the center bypass passage 60 of the second hydraulic pump 51 side is closed. As a result, the hydraulic oil discharged from the second hydraulic pump 51 is supplied to the boom cylinder 64 through the parallel line 63 and the second control valve 66. In other words, the boom cylinder 64 is driven by the hydraulic oil from the second hydraulic pump 51.

이때, 제3유압펌프(69)로부터의 작동유는 제1유압펌프(50)측 센터바이패스통로(52)를 통하여 유압탱크로 귀환되므로 붐실린더(64)에 공급되는 작동유에 합류되지 못한다.At this time, the hydraulic oil from the third hydraulic pump 69 is returned to the hydraulic tank through the center bypass passage 52 on the first hydraulic pump 50 and thus cannot be joined to the hydraulic oil supplied to the boom cylinder 64.

한편, 붐 구동속도를 증속시킬 수 있도록 제2제어밸브(66)를 절환시키고 작업장치용 제1제어밸브(68)를 절환시키는 경우, 제1유압펌프(50)측 센터바이패스통로(52) 및 제2유압펌프(51)측 센터바이패스통로(60)가 각각 닫힌다.On the other hand, when the second control valve 66 is switched to increase the boom driving speed and the first control valve 68 for the work device is switched, the center bypass passage 52 of the first hydraulic pump 50 side is changed. And the second hydraulic pump 51 side center bypass passage 60 are closed respectively.

이로 인해, 제3유압펌프(69)로부터의 작동유는, 제1유압펌프(50)로부터 병렬라인(55) 및 제1제어밸브(68)를 통해 공급되는 작동유와, 제2유압펌프로부터 병렬라인(63) 및 제2제어밸브(66)를 통해 공급되는 작동유와 합류되어 붐실린더(64)에 공급된다.Thus, the hydraulic oil from the third hydraulic pump 69 is supplied from the first hydraulic pump 50 through the parallel line 55 and the first control valve 68 and the parallel oil from the second hydraulic pump. The hydraulic oil supplied through the 63 and the second control valve 66 is joined to the boom cylinder 64.

따라서, 붐실린더(64)는 제1,2,3유압펌프(50,51,69)로부터 각각 공급되는 작동유에 의해 구동되므로, 이의 구동속도를 증속시킬 수 있다.Therefore, the boom cylinder 64 is driven by the hydraulic oil supplied from the first, second, and third hydraulic pumps 50, 51, and 69, respectively, so that the driving speed thereof can be increased.

한편, 아암실린더(57)의 구동을 제어하는 제어밸브(59,76)가 제1,2제어밸브(68,66)의 하류측에 각각 설치되어 병렬라인(55,63)을 통해 연결되므로, 아암실린더(57)를 구동시 붐실린더(64)의 구동시와 동일하게 제3유압펌프(69)로부터의 작동유를 보충받을 수 있다.On the other hand, since the control valves 59 and 76 for controlling the drive of the arm cylinder 57 are installed downstream of the first and second control valves 68 and 66, respectively, and are connected through the parallel lines 55 and 63, When the arm cylinder 57 is driven, the hydraulic oil from the third hydraulic pump 69 can be replenished in the same manner as when the boom cylinder 64 is driven.

한편, 제1제어밸브(58)를 조작하여 선회모터(56)를 구동시키는 경우, 제3유압펌프(69)로부터의 작동유는 제2유압펌프(51)측 센터바이패스통로(60)의 작동유 압력보다 상대적으로 낮다(언로딩됨). 따라서 제3유압펌프(69)의 작동유가 선회모터(56)를 구동시키는 작동유에 합류되지 못하므로 선회모터(56)는 제1유압펌프(50)로부터 공급되는 작동유에 의해서 구동된다.On the other hand, when operating the swing motor 56 by operating the first control valve 58, the hydraulic oil from the third hydraulic pump 69 is the hydraulic oil of the center bypass passage 60 on the second hydraulic pump 51 side. Relatively lower than pressure (unloaded). Therefore, since the hydraulic oil of the third hydraulic pump 69 does not join the hydraulic oil for driving the swing motor 56, the swing motor 56 is driven by the hydraulic oil supplied from the first hydraulic pump 50.

즉, 선회모터(56)는 구동시 제3유압펌프(69)로부터 작동유를 보충받아야할 만큼 많은 유량이 불필요하므로 제1유압펌프(50)로부터 공급되는 작동유에 의해서도 원활하게 작동될 수 있다.That is, since the swing motor 56 does not require much flow rate to be replenished with the hydraulic oil from the third hydraulic pump 69 when driven, the swing motor 56 may be smoothly operated by the hydraulic oil supplied from the first hydraulic pump 50.

한편, 붐실린더(64)를 구동시키는 도중에 주행장치를 구동시켜 복합작업을 수행할 경우, 제1유압펌프(50)측 병렬라인(55)의 상류측에 설치된 역류방지용 체크밸브(81)와, 제2유압펌프(51)측 병렬라인(63)의 상류측에 설치된 역류방지용 체크밸브(72)에 의해 붐실린더(64)측에 공급되는 작동유가 주행용 제1,2제어밸브(54,62)에 공급되는 것이 방지된다.On the other hand, when performing a complex operation by driving the traveling device in the middle of driving the boom cylinder 64, the check valve 81 for preventing the reverse flow provided on the upstream side of the parallel line 55 side of the first hydraulic pump 50, The hydraulic oil supplied to the boom cylinder 64 side by the check valve 72 for preventing the reverse flow installed on the upstream side of the parallel line 63 on the second hydraulic pump 51 side (54,62) ) Is prevented.

이로 인해, 제3유압펌프(69)로부터의 작동유를 작업장치측에 합류시키는 경 우에도 주행 직진에 영향을 주지 않게된다. Thus, even when the hydraulic oil from the third hydraulic pump 69 is joined to the work device side, the driving straightness is not affected.

전술한 바와 같이, 제3유압펌프(69)로부터의 작동유를 토출유로(80) 및 제1,2통로(84,87)를 통해 제1,2유압펌프(50,51)측 작동유에 동일한 유량을 각각 합류시킴에 따라, 제1유압펌프(50)측 제어밸브 및 제2유압펌프(51)의 제어밸브중 어느 한쪽 제어밸브에만 큰 압력 손실을 발생시키지 않으며, 압력손실을 균등화하여 최소로 할 수 있다.As described above, the flow rate of the hydraulic oil from the third hydraulic pump 69 is equal to the hydraulic fluid of the first and second hydraulic pumps 50 and 51 through the discharge passage 80 and the first and second passages 84 and 87. By combining the respective pressures, a large pressure loss is not generated in only one of the control valves of the first hydraulic pump 50 side control valve and the second hydraulic pump 51, and the pressure loss is equalized to minimize the pressure loss. Can be.

도 6에 도시된 바와 같이, 본 발명의 다른 실시예에 의한 건설장비용 유압시스템은,As shown in Figure 6, the hydraulic system for construction equipment according to another embodiment of the present invention,

엔진에 연결되는 가변용량형 제1,2,3유압펌프(50,51,69)와,Variable displacement first, second, and third hydraulic pumps (50, 51, 69) connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56) 및 아암실린더(57) 의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 on the downstream side of the first control valve 54 for traveling, and is connected through the parallel line 55, respectively, the boom cylinder 64, the swing motor 56 and the arm cylinder 57 First control valves 68, 58, and 59 for controlling the working oil supplied to the working device of

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65) 및 아암실린 더(57)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브(66,,67,76)와,It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel, and is connected through the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65 and the arm cylinder ( Second control valves 66, 67, and 76 for the working device, respectively, for controlling the hydraulic oil supplied to the working device of the working device;

제3유압펌프(69)의 토출유로(80)에 접속되고, 작업장치용 제1,2제어밸브중 최하류측 제어밸브(59,76)의 입력포트에 제1,2체크밸브(82,83)를 통해 각각 접속되는 제1통로(84)와,It is connected to the discharge flow path 80 of the third hydraulic pump 69, and the first and second check valves 82, to the input port of the lowest control valve 59, 76 of the first and second control valves for the working apparatus. First passages 84 connected respectively through 83;

제3유압펌프(69)의 토출유로(80)에 접속되고, 제1,2유압펌프(50,51)의 병렬라인(55,63) 최하류측에 제3,4체크밸브(85,86)를 통해 각각 접속되는 제2통로(87)를 포함한다.The third and fourth check valves 85 and 86 are connected to the discharge flow path 80 of the third hydraulic pump 69 and are located at the most downstream side of the parallel lines 55 and 63 of the first and second hydraulic pumps 50 and 51. And second passages 87 connected to each other.

이때, 제3유압펌프(69)로부터의 작동유를 제1,2유압펌프(50,51)의 최하류측 제1,2제어밸브(59,76)의 입력포트에 연결하여, 제1,2제어밸브(59,76)의 절환으로 인해 제어되는 아암실린더(57)에만 제3유압펌프(69)의 작동유를 합류시키도록 사용되는 제1,2통로(84,87)를 제외한 구성은, 도 5에 도시된 유압시스템의 구성과 실질적으로 동일하게 적용되므로 이들의 상세한 설명은 생략하고, 중복되는 도면부호는 동일하게 표기한다.At this time, the hydraulic oil from the third hydraulic pump 69 is connected to the input ports of the first and second control valves 59 and 76 on the most downstream side of the first and second hydraulic pumps 50 and 51, respectively. The configuration except for the first and second passages 84 and 87 used to join the hydraulic oil of the third hydraulic pump 69 only to the arm cylinder 57 controlled by the switching of the control valves 59 and 76 is illustrated in FIG. Since the same applies to the configuration of the hydraulic system shown in 5, the detailed description thereof will be omitted, and overlapping reference numerals will be denoted the same.

따라서, 아암을 구동시키기 위하여 제1제어밸브(59)를 절환시킬 경우 제1유압펌프(50)측 센터바이패스통로(52)는 닫히게 된다. 이로 인해 병렬라인(55)을 통해 공급되는 제1유압펌프(50)의 작동유는 토출유로(80)를 통해 공급되는 제3유압펌프(69)의 작동유와 합류된 후, 제1제어밸브(59)의 입력포트에 공급된다.Therefore, when switching the first control valve 59 to drive the arm, the center bypass passage 52 of the first hydraulic pump 50 side is closed. Accordingly, the hydraulic oil of the first hydraulic pump 50 supplied through the parallel line 55 joins the hydraulic oil of the third hydraulic pump 69 supplied through the discharge passage 80, and then the first control valve 59. It is supplied to the input port of).

제1제어밸브(59)의 출력포트에서는 제2제어밸브(76)의 절환으로 인해 제2유압펌프(51)로부터 공급되는 작동유와 합류되어 아암실린더(57)에 공급된다.In the output port of the first control valve 59, due to the switching of the second control valve 76 is joined with the hydraulic oil supplied from the second hydraulic pump 51 is supplied to the arm cylinder (57).

따라서, 아암실린더(57)는 제1,2,3유압펌프(50,51,69)로부터 공급되는 작동유에 의해 구동되므로, 이의 구동속도를 증속시킬 수 있다.Therefore, since the arm cylinder 57 is driven by the hydraulic oil supplied from the 1st, 2nd, 3rd hydraulic pumps 50, 51 and 69, it can speed up the drive speed.

도 7에 도시된 바와 같이, 본 발명의 또 다른 실시예에 의한 건설장비용 유압시스템은,As shown in Figure 7, the hydraulic system for construction equipment according to another embodiment of the present invention,

엔진에 연결되는 가변용량형 제1,2,3유압펌프(50,51,69)와,Variable displacement first, second, and third hydraulic pumps (50, 51, 69) connected to the engine;

제1유압펌프(50)의 센터바이패스통로(52)에 설치되고, 좌측 주행모터(53)의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브(54)와,A first control valve 54 for driving provided in the center bypass passage 52 of the first hydraulic pump 50 for controlling the starting, stopping, and direction change of the left traveling motor 53;

주행용 제1제어밸브(54)의 하류측으로 센터바이패스통로(52)에 설치되고, 병렬라인(55)을 통해 각각 연결되며, 붐실린더(64), 선회모터(56), 아암실린더(59)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브(68,58,59)와,It is installed in the center bypass passage 52 on the downstream side of the first control valve 54 for travel, and is connected through the parallel line 55, respectively, the boom cylinder 64, the swing motor 56, the arm cylinder 59 First control valves 68, 58, 59 for the working device to control the hydraulic fluid supplied to the working device of the),

제2유압펌프(51)의 센터바이패스통로(60)에 설치되고, 우측 주행모터(61)의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브(62)와,A second control valve 62 for traveling installed in the center bypass passage 60 of the second hydraulic pump 51 for controlling the starting, stopping, and direction change of the right traveling motor 61;

주행용 제2제어밸브(62)의 하류측으로 센터바이패스통로(60)에 설치되고, 병렬라인(63)을 통해 각각 연결되며, 붐실린더(64), 버킷실린더(65), 아암실린더(57)의 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브(66,67,76)와,It is installed in the center bypass passage 60 to the downstream side of the second control valve 62 for travel, and is connected via the parallel line 63, respectively, the boom cylinder 64, the bucket cylinder 65, the arm cylinder 57 Second control valves 66, 67, and 76 for the work device for controlling the hydraulic oil supplied to the work device of

제3유압펌프(69)의 토출유로(80)에 접속되고, 주행용 제1,2제어밸브(54,62)의 하류측에서 제1,2유압펌프(50,51)의 병렬라인(55,63)에 제3,4체크밸브(85,86)를 통해 각각 접속되는 제2통로(87)와,A parallel line 55 of the first and second hydraulic pumps 50 and 51 is connected to the discharge passage 80 of the third hydraulic pump 69 and downstream from the first and second control valves 54 and 62 for travel. A second passage (87) connected to the (63) through the third and fourth check valves (85, 86),

제3유압펌프(69)의 토출유로(80)에 설치되고 붐 등의 작업장치를 조작시 공급되는 전기적 신호에 의해 절환되며, 절환시 제3유압펌프(69)로부터의 작동유를 제1,2유압펌프(50,51)의 병렬라인(55,63)에 각각 공급하며, 중립시 제3유압펌프(69)로부터의 작동유를 유압탱크로 귀환시키는 언로드밸브(100)를 포함한다.It is installed in the discharge flow path 80 of the third hydraulic pump 69 and is switched by an electrical signal supplied when operating a work device such as a boom, and when switching the hydraulic oil from the third hydraulic pump 69 Supply to the parallel lines (55, 63) of the hydraulic pump (50, 51), respectively, and includes an unload valve 100 for returning the hydraulic oil from the third hydraulic pump 69 to the hydraulic tank.

이때, 전술한 제2통로(87) 및 언로드밸브(100)를 제외한 구성은 도 5에 도시된 유압시스템의 구성과 실질적으로 동일하게 적용되므로 이들의 상세한 설명은 생략하고, 중복되는 도면부호는 동일하게 표기한다.At this time, the configuration except for the above-described second passage 87 and the unload valve 100 is applied substantially the same as the configuration of the hydraulic system shown in Figure 5, so that the detailed description thereof will be omitted, duplicate reference numerals are the same To be written.

따라서, 붐 등의 작업장치를 조작할 경우 공급되는 전기적 신호에 의해 언로드밸브(100)가 도면상, 우측방향으로 절환된다. 이로 인해 제3유압펌프(69)로부터의 작동유는 토출유로(80) - 언로드밸브(100) - 제2통로(87)에 설치된 체크밸브(85,86)를 통해 제1,2유압펌프(50,51)의 병렬라인(55,63)에 공급된다.Therefore, when operating a work device such as a boom, the unload valve 100 is switched to the right in the drawing by an electrical signal supplied. As a result, the hydraulic oil from the third hydraulic pump 69 passes through the first and second hydraulic pumps 50 through the check valves 85 and 86 installed in the discharge passage 80, the unload valve 100, and the second passage 87. It is supplied to the parallel lines 55 and 63 of 51.

반면에, 언로드밸브(100)가 중립을 유지하는 경우(도 7에 도시된 상태), 제3유압펌프(69)로부터의 작동유는 언로드밸브(100)를 경유하여 유압탱크로 귀환된다.On the other hand, when the unload valve 100 remains neutral (state shown in FIG. 7), the hydraulic oil from the third hydraulic pump 69 is returned to the hydraulic tank via the unload valve 100.

전술한 바와 같이, 본 발명의 실시예에 의한 건설장비용 유압시스템은, 굴삭기와 같은 건설장비에 적용되는 2개의 유압펌프를 사용하는 유압시스템에 제3유압펌프를 추가시킴에 따라, 제3유압펌프로부터의 작동유를 해당 작업장치의 액츄에이터에 합류시켜 주행 직진성을 확보하면서 작업장치의 구동속도를 증속시킬 수 있다.As described above, the hydraulic system for construction equipment according to the embodiment of the present invention, by adding a third hydraulic pump to the hydraulic system using two hydraulic pumps applied to the construction equipment such as excavators, the third hydraulic pressure The hydraulic oil from the pump can be joined to the actuator of the work device to increase the driving speed of the work device while ensuring the driving straightness.

또한, 추가되는 제3유압펌프로부터의 작동유를 작업장치에 합류시 발생되는 압력 손실을 최소화하여 에너지 손실을 줄일 수 있다.In addition, it is possible to reduce the energy loss by minimizing the pressure loss generated when the hydraulic oil from the additional third hydraulic pump is joined to the work device.

도 1은 일반적인 굴삭기의 개략도,1 is a schematic view of a typical excavator,

도 2는 종래 기술에 의한 건설장비용 유압시스템의 개략도,2 is a schematic view of a hydraulic system for construction equipment according to the prior art,

도 3은 종래 기술에 의한 건설장비용 유압시스템의 변형예시도,3 is a modified example of the hydraulic system for construction equipment according to the prior art,

도 4는 종래 기술에 의한 건설장비용 유압시스템의 다른 변형예시도,4 is another modified example of the hydraulic system for construction equipment according to the prior art,

도 5는 본 발명의 일 실시예에 의한 건설장비용 유압시스템의 개략도,5 is a schematic view of a hydraulic system for construction equipment according to an embodiment of the present invention,

도 6은 본 발명의 다른 실시예에 의한 건설장비용 유압시스템의 개략도,6 is a schematic view of a hydraulic system for construction equipment according to another embodiment of the present invention,

도 7은 본 발명의 또 다른 실시예에 의한 건설장비용 유압시스템의 개략도이다.7 is a schematic diagram of a hydraulic system for construction equipment according to another embodiment of the present invention.

*도면중 주요 부분에 사용된 부호의 설명* Explanation of symbols used in the main part of the drawing

50; 제1유압펌프50; 1st hydraulic pump

51; 제2유압펌프51; 2nd hydraulic pump

52,60; 센터바이패스통로52,60; Center bypass passage

53; 좌측 주행모터53; Left motor

54; 주행용 제1제어밸브54; First control valve for driving

55,63; 병렬라인55,63; Parallel line

56; 선회모터56; Turning motor

57; 아암실린더57; Arm cylinder

58,59; 작업장치용 제1제어밸브58,59; First control valve for work equipment

61; 우측 주행모터61; Right driving motor

62; 주행용 제2제어밸브62; Traveling Second Control Valve

64; 붐실린더64; Boom cylinder

65; 버킷실린더65; Bucket cylinder

66,67; 작업장치용 제2제어밸브66,67; Second control valve for work equipment

69; 제3유압펌프69; 3rd hydraulic pump

72,81,82,83,85,86; 체크밸브72,81,82,83,85,86; Check valve

80; 토출유로80; Discharge path

84; 제1통로84; The first passage

87; 제2통로87; Second passage

100; 언로드밸브100; Unload Valve

Claims (4)

엔진에 연결되는 제1,2,3유압펌프;First, second and third hydraulic pumps connected to the engine; 상기 제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브;A first control valve installed in a center bypass passage of the first hydraulic pump and configured to control start, stop, and direction change of the left driving motor; 상기 주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브;A first control valve for the work device which is installed in the center bypass passage downstream of the first control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브;A second control valve installed in the center bypass passage of the second hydraulic pump and configured to control start, stop and direction change of the right traveling motor; 상기 주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브;A second control valve for the work device which is installed in the center bypass passage downstream of the second control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제3유압펌프의 토출유로에 접속되고, 상기 주행용 제1,2제어밸브의 하류측에서 상기 제1,2유압펌프의 센터바이패스통로에 제1,2체크밸브를 통해 각각 접속되는 제1통로; 및A first passage connected to the discharge passage of the third hydraulic pump and connected to the center bypass passages of the first and second hydraulic pumps on the downstream side of the first and second control valves for driving through the first and second check valves, respectively. 1 passage; And 상기 제3유압펌프의 토출유로에 접속되고, 상기 주행용 제1,2제어밸브의 하류측에서 상기 제1,2유압펌프의 병렬라인에 제3,4체크밸브를 통해 각각 접속되는 제2통로를 포함하는 것을 특징으로 하는 건설장비용 유압시스템.A second passage connected to the discharge passage of the third hydraulic pump and connected to the parallel lines of the first and second hydraulic pumps on the downstream side of the first and second control valves for driving through third and fourth check valves, respectively; Hydraulic system for construction equipment comprising a. 엔진에 연결되는 제1,2,3유압펌프;First, second and third hydraulic pumps connected to the engine; 상기 제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브;A first control valve installed in a center bypass passage of the first hydraulic pump and configured to control start, stop, and direction change of the left driving motor; 상기 주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브;A first control valve for the work device which is installed in the center bypass passage downstream of the first control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브;A second control valve installed in the center bypass passage of the second hydraulic pump and configured to control start, stop and direction change of the right traveling motor; 상기 주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브;A second control valve for the work device which is installed in the center bypass passage downstream of the second control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제3유압펌프의 토출유로에 접속되고, 상기 작업장치용 제1,2제어밸브중 최하류측 제어밸브의 입력포트에 제1,2체크밸브를 통해 각각 접속되는 제1통로; 및A first passage connected to the discharge passage of the third hydraulic pump and connected to the input port of the downstreammost control valve of the first and second control valves for the working apparatus through first and second check valves, respectively; And 상기 제3유압펌프의 토출유로에 접속되고, 상기 제1,2유압펌프의 병렬라인 최하류측에 제3,4체크밸브를 통해 각각 접속되는 제2통로를 포함하는 것을 특징으로 하는 건설장비용 유압시스템.And a second passage connected to the discharge passage of the third hydraulic pump and connected to the downstream of the parallel line of the first and second hydraulic pumps via third and fourth check valves, respectively. Hydraulic system. 엔진에 연결되는 제1,2,3유압펌프;First, second and third hydraulic pumps connected to the engine; 상기 제1유압펌프의 센터바이패스통로에 설치되고, 좌측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제1제어밸브;A first control valve installed in a center bypass passage of the first hydraulic pump and configured to control start, stop, and direction change of the left driving motor; 상기 주행용 제1제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제1제어밸브;A first control valve for the work device which is installed in the center bypass passage downstream of the first control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제2유압펌프의 센터바이패스통로에 설치되고, 우측 주행모터의 기동, 정지 및 방향전환을 제어하는 주행용 제2제어밸브;A second control valve installed in the center bypass passage of the second hydraulic pump and configured to control start, stop and direction change of the right traveling motor; 상기 주행용 제2제어밸브의 하류측으로 센터바이패스통로에 설치되고, 병렬라인을 통해 각각 연결되며, 작업장치에 공급되는 작동유를 각각 제어하는 작업장치용 제2제어밸브;A second control valve for the work device which is installed in the center bypass passage downstream of the second control valve for travel and connected through parallel lines, respectively, and controls the hydraulic oil supplied to the work device; 상기 제3유압펌프의 토출유로에 접속되고, 상기 주행용 제1,2제어밸브의 하류측에서 상기 제1,2유압펌프의 병렬라인에 제3,4체크밸브를 통해 각각 접속되는 제2통로; 및A second passage connected to the discharge passage of the third hydraulic pump and connected to the parallel lines of the first and second hydraulic pumps on the downstream side of the first and second control valves for driving through third and fourth check valves, respectively; ; And 상기 제3유압펌프의 토출유로에 설치되고, 작업장치를 조작시 절환되어 상기 제3유압펌프로부터의 작동유를 상기 제1,2유압펌프의 병렬라인에 각각 공급하는 언로드밸브를 포함하는 것을 특징으로 하는 건설장비용 유압시스템.And an unload valve installed in the discharge flow path of the third hydraulic pump and switched when the work device is operated to supply hydraulic oil from the third hydraulic pump to parallel lines of the first and second hydraulic pumps, respectively. Hydraulic systems for construction equipment. 청구항 1 내지 청구항 3중 적어도 어느 하나의 항에 있어서, 상기 제1유압펌프의 병렬라인의 상류측에 설치되고, 상기 제1유압펌프측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브와,The work device side according to any one of claims 1 to 3, which is provided on an upstream side of the parallel line of the first hydraulic pump and simultaneously drives the first hydraulic pump side working device and the traveling device at the same time. Check valve for preventing the flow of hydraulic oil from the 상기 제2유압펌프의 병렬라인의 상류측에 설치되고, 상기 제2유압펌프측 작업장치와 주행장치를 동시에 구동시키는 복합작업시 작업장치측에서 주행장치측으로 작동유 공급되는 것을 차단하는 역류방지용 체크밸브를 포함하는 것을 특징으로 하는 건설장비용 유압시스템.A check valve for preventing a back flow installed on an upstream side of the parallel line of the second hydraulic pump and blocking supply of hydraulic oil from the working device side to the traveling device side during a combined operation for simultaneously driving the second hydraulic pump side working device and the traveling device. Hydraulic system for construction equipment comprising a.
KR1020080100107A 2008-08-21 2008-10-13 hydraulic system of construction equipment KR100961433B1 (en)

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KR1020080100107A KR100961433B1 (en) 2008-10-13 2008-10-13 hydraulic system of construction equipment
EP09010569.3A EP2157245B1 (en) 2008-08-21 2009-08-17 Hydraulic system for construction equipment
JP2009189831A JP5564215B2 (en) 2008-08-21 2009-08-19 Hydraulic system for construction machinery
CN2009101629749A CN101676495B (en) 2008-08-21 2009-08-20 Hydraulic system for construction equipment
US12/545,653 US8572957B2 (en) 2008-08-21 2009-08-21 Hydraulic system for construction equipment

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WO2015012423A1 (en) * 2013-07-24 2015-01-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction machine

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JP5771332B2 (en) * 2011-08-09 2015-08-26 ボルボ コンストラクション イクイップメント アーベー Hydraulic control system for construction machinery
WO2013094793A1 (en) * 2011-12-23 2013-06-27 볼보 컨스트럭션 이큅먼트 에이비 Drive merge control system for construction machine

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Publication number Priority date Publication date Assignee Title
WO2015012423A1 (en) * 2013-07-24 2015-01-29 볼보 컨스트럭션 이큅먼트 에이비 Hydraulic circuit for construction machine
US10184499B2 (en) 2013-07-24 2019-01-22 Volvo Construction Equipment Ab Hydraulic circuit for construction machine

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