KR20000021940A - Booster for work equipment of construction machine - Google Patents

Booster for work equipment of construction machine Download PDF

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Publication number
KR20000021940A
KR20000021940A KR1019980041230A KR19980041230A KR20000021940A KR 20000021940 A KR20000021940 A KR 20000021940A KR 1019980041230 A KR1019980041230 A KR 1019980041230A KR 19980041230 A KR19980041230 A KR 19980041230A KR 20000021940 A KR20000021940 A KR 20000021940A
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KR
South Korea
Prior art keywords
pressure
relief valve
cylinder
variable relief
boom cylinder
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KR1019980041230A
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Korean (ko)
Inventor
이병호
Original Assignee
토니헬샴
볼보건설기계코리아 주식회사
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Application filed by 토니헬샴, 볼보건설기계코리아 주식회사 filed Critical 토니헬샴
Priority to KR1019980041230A priority Critical patent/KR20000021940A/en
Publication of KR20000021940A publication Critical patent/KR20000021940A/en

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
    • E02F9/2228—Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
    • E02F9/2267—Valves or distributors

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

Abstract

PURPOSE: A booster is provided to increase a durability of an equipment by preventing an overload in a work equipment when the load over the pressure established in the work equipment is applied while working using a construction heavy equipment such as a loader. CONSTITUTION: A booster is composed of: a first sensor(18a) for detecting an operation pressure to a boom cylinder(14), a second sensor(18b) for detecting the operation pressure at a bucket cylinder(15), a third sensor(18c) for detecting a traveling speed of an equipment. And a variable relief valve(16) is established at a control valve(13) for returning the operation pressure to a hydraulic pressure tank(T) when the load over the pressure established in the boom cylinder(14) and the bucket cylinder(15) is applied. When the load over the pressure established in the boom cylinder(14) and the bucket cylinder(15) is applied, a solenoid valve(12) is established to be switched according to an input of a specific signal to a vent line(19) of the variable relief valve(16) for increasing an established pressure of the variable relief valve.

Description

건설기계의 작업장치용 승압장치Pressure booster for work equipment of construction machinery

본 발명은 건설기계의 작업장치용 승압장치에 관한 것으로, 더욱 상세하게는 로우더와 같은 건설중장비를 이용하여 작업하는 도중 작업장치에 설정된 압력이상의 부하가 발생되는 경우 작업장치에 여분의 작동압을 공급하여 작업의 연속성을 확보할 수 있도록 한 건설기계의 작업장치용 승압장치에 관한 것이다.The present invention relates to a pressure booster for a work device of a construction machine, and more particularly, to supply an extra working pressure to the work device when a load greater than the pressure set in the work device occurs while working with heavy equipment such as a loader The present invention relates to a booster for a work device of a construction machine to ensure continuity of work.

일반적으로, 로우더는 작업장치가 적재물을 파고 들어가서 적재물을 굴삭후 이를 원하는 높이까지 들어올린 다음, 소정거리 주행하여 덤프트럭 등에 적재하는 작업("상차작업" 이라함)을 주로 하게된다. 이때, 작업장치가 적재물을 파고 들어가는 것과 동시에 운전자가 작업장치(붐 또는 버킷)를 움직여서 적재물이 작업장치에 최적상태로 적재되도록 한다.In general, the loader is mainly carried out by the work device to dig the load, excavate the load and lift it up to a desired height, and then run a predetermined distance to load the dump truck and the like (called "loading operation"). At this time, the working device is digging into the load and the driver moves the working device (boom or bucket) so that the load is optimally loaded on the working device.

도 1은 종래 기술에 의한 건설기계의 작업장치용 유압회로도 이다.1 is a hydraulic circuit diagram for a working device of a construction machine according to the prior art.

도시된 바와 같이, 미도시된 엔진에 의해 구동하는 유압펌프(1)와, 유압펌프(1)에 붐실린더(4) 및 버킷실린더(5)가 연결되며, 유압펌프(1)와 붐실린더(4) 및 버킷실린더(5)사이에 이들 실린더에 공급되는 작동유의 량 및 흐름방향을 제어하는 컨트롤밸브(2)가 설치된다. 이때, 컨트롤밸브(2)는 작업중 붐실린더(4)와 버킷실린더(5)에 설정된 압력이상의 부하가 발생되는 경우 작동압을 유압탱크(6)로 귀환시켜 유압라인 및 부품을 보호하는 릴리프밸브(3)를 포함한다.As shown, the hydraulic pump 1 driven by the engine not shown, the boom cylinder 4 and the bucket cylinder 5 is connected to the hydraulic pump 1, the hydraulic pump 1 and the boom cylinder ( Between 4) and the bucket cylinder 5, a control valve 2 for controlling the amount and flow direction of the working oil supplied to these cylinders is provided. At this time, the control valve (2) is a relief valve for protecting the hydraulic line and parts by returning the operating pressure to the hydraulic tank (6) when a load greater than the pressure set in the boom cylinder (4) and bucket cylinder (5) during operation ( Include 3).

그러나, 작업장치가 적재물을 파고 들어가는 과정에서 작업장치에 설정된 부하가 발생되어(릴리프상태) 작업장치가 전혀 움직이지 못하는 상태가 발생된다. 즉, 붐 또는 버킷 구동용 실린더에 설정된 최대압력(릴리프압력)이 발생된 상태로서 작업장치가 외부 부하조건을 극복하지 못하는 상태에 직면하게 된다. 이로 인해, 작업이 일시 중단되므로, 운전자는 이와 같은 작업조건 상태를 벗어나기 위하여 작업장치를 후진시킨 다음, 적재물에 다시 파고 들어가는 작업을 반복하게 되므로 작업이 지연되어 작업성이 떨어지는 문제점을 갖는 것이다.However, a load set on the work device is generated in the process of digging into the load (relief state), and thus the work device does not move at all. That is, the maximum pressure (relief pressure) set in the boom or bucket driving cylinder is generated, and the working apparatus faces a state in which it cannot overcome the external load condition. Because of this, since the work is suspended, the driver is to reverse the work device in order to get out of the working condition, and then repeats the work to be dug into the load again, the work is delayed and workability is inferior.

이와 같이, 작업이 지연되는 것을 방지하기 위하여 작업장치가 적재물을 조금이라도 움직여서 그 한계조건상태를 벗어날 수 있도록 한다. 즉, 작업장치를 강제적으로 움직여 작업장치가 적재물을 파고 들어가는 각도를 변경하여 한계상태가 된 작업장치를 한계조건(릴리프상태)에서 벗어나도록 하면, 작업장치는 릴리프압력상태에서 벗어나게 되어 엔진의 동력중 여분의 동력이 장비의 바퀴에 공급되도록 하여, 장비의 견인력을 향상시킴에 따라 작업의 연속성이 확보되었다.In this way, the work device may move the load a little to get out of the limit condition in order to prevent the work delay. In other words, if the work device is forcibly moved to change the angle at which the work device digs into the load, and the work device that is in the limit state is released from the limit condition (relief state), the work device is released from the relief pressure state and the engine By allowing extra power to be supplied to the wheels of the machine, the continuity of the work was ensured by improving the traction of the machine.

따라서, 장비에 과부하가 발생되어 장비의 내구성이 떨어지며, 운전자의 피로도는 가중되는 것이었다.As a result, the machine was overloaded, resulting in poor durability and increased operator fatigue.

따라서, 본 발명의 목적은, 로우더와 같은 건설중장비를 이용하여 작업하는 도중 작업장치에 설정된 압력이상의 부하가 발생되는 경우 작업장치에 여분의 작동압을 공급함에 따라 작업의 연속성 확보로 작업성을 향상시킬 수 있으며, 작업장치에 과부하 발생되는 것을 방지하여 장비의 내구성을 증대시킬 수 있도록 한 건설기계의 작업장치용 승압장치를 제공하는 것이다.Accordingly, an object of the present invention is to improve workability by securing the continuity of work by supplying an extra working pressure to the work device when a load greater than the pressure set in the work device occurs during work using heavy construction equipment such as a loader It is possible to provide, and to increase the durability of the equipment by preventing the overload of the working device to provide a boosting device for the working device of the construction machine.

도 1은 종래 기술에 의한 건설기계의 작업장치용 유압회로도,1 is a hydraulic circuit diagram for a working device of a construction machine according to the prior art,

도 2는 본 발명의 실시예에 의한 건설기계의 작업장치용 승압장치의 유압회로도 이다.2 is a hydraulic circuit diagram of a boosting device for a work device of a construction machine according to an embodiment of the present invention.

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

11;유압펌프11; hydraulic pump

12;솔레노이드밸브12; solenoid valve

13;컨트롤밸브13; control valve

14;붐실린더14; boom cylinder

15;버킷실린더15; bucket cylinder

16;가변 릴리프밸브16; variable relief valve

17;컨트롤러17; controller

18a;제 1 센서18a; first sensor

18b;제 2 센서18b; second sensor

18c;제 3 센서18c; third sensor

18d;선택스위치18d; selector switch

19;토출유로(VENT LINE)19; VENT LINE

전술한 본 발명의 목적은, 유압펌프와, 상기 유압펌프에 연결되어 구동하는 붐실린더 및 버킷실린더와, 상기 유압펌프와 상기 붐실린더 및 버킷실린더사이에 설치되며 작동유의 량 및 흐름방향을 제어하는 컨트롤밸브를 구비하는 건설기계의 작업장치용 승압장치에 있어서: 상기 붐실린더에 형성되어 상기 붐실린더의 작동압력을 검출하는 제 1 센서; 상기 버킷실린더에 형성되어 상기 버킷실린더의 작동압력을 검출하는 제 2 센서; 장비의 주행속도를 검출하도록 설치되는 제 3 센서; 상기 컨트롤밸브에 형성되며, 상기 붐실린더 및 버킷실린더에 설정된 압력이상의 부하가 발생되는 경우 작동압을 유압탱크로 귀환시키는 가변 릴리프밸브; 상기 가변 릴리프밸브의 토출유로에 소정신호 입력에 따라 절환되도록 설치되며, 상기 붐실린더 및 버킷실린더에 설정된 압력이상의 부하발생시 절환되어 상기 가변 릴리프밸브의 설정압력을 증가시키는 솔레노이드밸브; 운전자에 의해 상기 가변 릴리프밸브 제어기능을 선택하는 선택스위치; 상기 선택스위치 및 각 센서들로 부터 입력되는 검출신호에 따라 상기 가변 릴리프밸브에 소정신호를 인가하는 컨트롤러를 더 포함하여 구성됨을 특징으로 하는 건설기계의 작업장치용 승압장치를 제공함에 의해 달성된다.An object of the present invention described above is installed between a hydraulic pump, a boom cylinder and a bucket cylinder connected to and driven by the hydraulic pump, and installed between the hydraulic pump and the boom cylinder and the bucket cylinder to control the amount and flow direction of the working oil. A booster for a work machine of a construction machine having a control valve, comprising: a first sensor formed on the boom cylinder to detect an operating pressure of the boom cylinder; A second sensor formed in the bucket cylinder to detect an operating pressure of the bucket cylinder; A third sensor installed to detect a traveling speed of the equipment; A variable relief valve formed in the control valve and returning the operating pressure to the hydraulic tank when a load greater than the pressure set in the boom cylinder and the bucket cylinder is generated; A solenoid valve installed to be switched according to a predetermined signal input in the discharge flow path of the variable relief valve and switched when a load greater than the pressure set in the boom cylinder and the bucket cylinder is generated to increase the set pressure of the variable relief valve; A selection switch for selecting the variable relief valve control function by a driver; It is achieved by providing a boosting device for a work machine of a construction machine, characterized in that it further comprises a controller for applying a predetermined signal to the variable relief valve in accordance with the detection signal input from the selection switch and the respective sensors.

이하, 본 발명의 바람직한 실시예를 첨부도면에 따라 상세하게 설명하며, 이는 본 발명 기술내용의 이해를 돕기 위한 것이지 이로 인해 본 발명의 기술적인 범주가 한정되는 것은 아니다.Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are intended to assist in understanding the technical contents of the present invention, and thus the technical scope of the present invention is not limited.

엔진에 의해 구동하는 유압펌프(11)와, 유압펌프(11)에 연결되어 구동하는 붐실린더(14) 및 버킷실린더(15)와, 유압펌프(11)와 붐실린더(14) 및 버킷실린더(15)사이에 설치되며 작동유의 량 및 흐름방향을 제어하는 컨트롤밸브(13)를 구비하는 로우더 등의 건설기계에 적용된다.A hydraulic pump 11 driven by an engine, a boom cylinder 14 and a bucket cylinder 15 connected to and driven by the hydraulic pump 11, a hydraulic pump 11, a boom cylinder 14 and a bucket cylinder ( It is applied to construction machinery such as a loader, which is installed between 15 and has a control valve 13 for controlling the amount and flow direction of the working oil.

따라서, 본 발명의 바람직한 실시예에 의하면, 전술한 붐실린더(14)에 이의 작동압력을 검출하는 제 1 센서(18a), 버킷실린더(15)에 이의 작동압력을 검출하는 제 2 센서(18b) 및 장비의 주행속도를 검출할 수 있도록 제 3 센서(18c)가 각각 설치되며, 전술한 붐실린더(14) 및 버킷실린더(15)에 설정된 압력이상의 부하가 발생되는 경우 작동압을 유압탱크(T)로 귀환시키는 가변 릴리프밸브(16)(밸런스 피스톤형 릴리프밸브)가 컨트롤밸브(13)에 설치되며, 붐실린더(14) 및 버킷실린더(15)에 설정된 압력이상의 부하발생시 가변 릴리프밸브(16)의 설정압력을 증가시켜주는 솔레노이드밸브(12)가 가변 릴리프밸브(16)의 토출유로(19)(VENT LINE)에 소정신호 입력에 따라 절환되도록 설치되며, 운전자에 의해 가변 릴리프밸브(16) 제어기능을 선택할 수 있도록 선택스위치(18d)가 형성되며, 선택스위치(18d) 및 각 센서(18a,18b,18c)들로 부터 입력되는 검출신호에 따라 가변 릴리프밸브(16)에 소정신호를 인가하는 컨트롤러(17)로서 구성된다.Accordingly, according to a preferred embodiment of the present invention, the first sensor 18a for detecting the operating pressure thereof in the above-described boom cylinder 14 and the second sensor 18b for detecting its operating pressure in the bucket cylinder 15 are described. And third sensors 18c are installed to detect the traveling speed of the equipment, respectively, and when a load greater than the pressure set in the above-described boom cylinder 14 and the bucket cylinder 15 is generated, the hydraulic pressure is applied to the hydraulic tank T. The variable relief valve 16 (balance piston type relief valve) returning to the control valve 13 is installed in the control valve 13, and the variable relief valve 16 when a load greater than the pressure set in the boom cylinder 14 and the bucket cylinder 15 is generated. The solenoid valve 12 for increasing the set pressure of the variable relief valve 16 is installed to be switched in accordance with a predetermined signal input to the discharge passage 19 (VENT LINE) of the variable relief valve 16, and the variable relief valve 16 is controlled by the driver. The selector switch 18d is shaped so that the function can be selected. And a controller 17 for applying a predetermined signal to the variable relief valve 16 in accordance with the selection switch 18d and the detection signals input from the sensors 18a, 18b, and 18c.

미설명부호 20은, 가변 릴리프밸브(16)의 제어기능이 해제될 때 붐실린더(14) 및 버킷실린더(15)에 설정된 압력이상의 부하발생시 작동압을 유압탱크(T)로 귀환시키는 릴리프밸브 이다.Reference numeral 20 is a relief valve for returning the operating pressure to the hydraulic tank T when a load greater than the pressure set in the boom cylinder 14 and the bucket cylinder 15 occurs when the control function of the variable relief valve 16 is released. .

위와같이 구성되는 본 발명의 실시예에 의한 건설기계의 작업장치용 승압장치의 작동을 설명하면 다음과 같다.Referring to the operation of the boosting device for a working device of a construction machine according to an embodiment of the present invention configured as described above are as follows.

즉, 로우더 등의 중장비를 이용하여 상차작업 하는 경우, 작업장치가 적재물을 파고 들어가서 버킷에 적재물을 적재하는 단계에서 작업장치(붐 또는 버킷)에 설정된 압력이상의 부하가 발생되어(릴리프상태) 작업장치를 전혀 움직이지 못하게되는 경우, 운전자는 작업장치를 구동하여 작업장치의 파고 들어가는 각도를 변경함에 따라 작업장치의 릴리프단계를 벗어날 수 있게된다.In other words, when loading the vehicle using heavy equipment such as a loader, a load of a pressure higher than the pressure set in the work device (boom or bucket) is generated during the work device digging into the load and loading the load into the bucket (relief state). If it does not move at all, the driver can drive the work tool to change the angle of entering the work tool to escape the relief phase of the work equipment.

즉, 전술한 바와 같은 작업장치가 릴리프단계인 경우, 전술한 센서(18a,18b,18c) 및 선택스위치(18d)에 의해 검출되는 검출신호가 전술한 컨트롤러17)에 입력됨에 따라, 컨트롤러(17)로 부터의 소정신호가 전술한 솔레노이드밸브(12)에 인가되어 내부 스플을 도 2의 도면상, 좌측방향으로 절환시킨다(도면상 "b"상태). 이로 인해, 전술한 가변 릴리프밸브(16)의 토출유로(19)는 전술한 솔레노이드밸브(12)에 의해 차단된다.That is, when the work device as described above is in the relief phase, the detection signal detected by the above-described sensors 18a, 18b, 18c and the selection switch 18d is input to the above-described controller 17, so that the controller 17 A predetermined signal from < RTI ID = 0.0 > 1) < / RTI > is applied to the solenoid valve 12 described above to switch the internal spool to the left side in the figure of FIG. For this reason, the discharge flow path 19 of the variable relief valve 16 mentioned above is interrupted | blocked by the solenoid valve 12 mentioned above.

따라서, 작업장치의 작동압은 전술한 가변 릴리프밸브(16)의 설정압으로 작동하게 되며(이때, 가변 릴리프밸브(16)의 설정압은 릴리프밸브(20)의 설정압보다 높게 설정된 것임), 이로 인해 작업장치(붐 또는 버킷)에 유압펌프(11)로 부터 토출되는 작동압중 여분의 작동압이 추가로 공급됨에 따라, 작업장치의 구동을 릴리프단계로 부터 벗어날 수 있게된다.Therefore, the working pressure of the working device is operated at the set pressure of the variable relief valve 16 described above (the set pressure of the variable relief valve 16 is set higher than the set pressure of the relief valve 20), As a result of the extra supply of the operating pressure discharged from the hydraulic pump 11 to the work device (boom or bucket), it is possible to escape the drive of the work device from the relief step.

한편, 작업장치가 릴리프단계를 벗어나 설정된 압력이하의 부하로서 정상적인 상태로 작업하는 경우, 전술한 솔레노이드밸브(12)는 이의 밸브스프링(12a)의 복원력에 의해 도 2의 도면에서와 같은 현재상태로 절환되며(도 2의 "a"상태), 이로 인해, 전술한 가변 릴리프밸브(16)의 토출유로(19)는 릴리프밸브(20)과 연통된다. 따라서, 작업장치의 구동은 릴리프밸브(20)의 설정압으로 작동된다.On the other hand, when the work device is working in a normal state as a load under the set pressure out of the relief step, the above-described solenoid valve 12 is returned to its current state as shown in FIG. 2 by the restoring force of the valve spring 12a. It is switched (“a” state in FIG. 2), whereby the discharge passage 19 of the variable relief valve 16 described above is in communication with the relief valve 20. Accordingly, the drive of the work device is operated at the set pressure of the relief valve 20.

이상에서와 같이, 바람직한 실시예에 의하면, 로우더와 같은 건설중장비를 이용하여 작업하는 도중 작업장치에 설정된 압력이상의 부하가 발생되는 경우 작업장치에 여분의 작동압을 공급함에 따라 작업의 연속성 확보로 작업성을 향상시킬 수 있으며, 작업장치에 과부하 발생되는 것을 방지하여 장비의 내구성을 증대시킬 수 있도록 한 이점을 갖는다.As described above, according to a preferred embodiment, when the load is greater than the pressure set in the work device during the operation using heavy construction equipment such as a loader, work by securing the continuity of work by supplying an extra working pressure to the work device It is possible to improve the durability, and to prevent the overload of the working device has the advantage to increase the durability of the equipment.

Claims (1)

유압펌프와, 상기 유압펌프에 연결되어 구동하는 붐실린더 및 버킷실린더와, 상기 유압펌프와 상기 붐실린더 및 버킷실린더사이에 설치되며 작동유의 량 및 흐름방향을 제어하는 컨트롤밸브를 구비하는 건설기계의 작업장치용 승압장치에 있어서:A construction machine comprising a hydraulic pump, a boom cylinder and a bucket cylinder connected to and driven by the hydraulic pump, and a control valve installed between the hydraulic pump and the boom cylinder and the bucket cylinder to control the amount and flow direction of the working oil. In the booster for work equipment: 상기 붐실린더에 형성되어 상기 붐실린더의 작동압력을 검출하는 제 1 센서;A first sensor formed in the boom cylinder to detect an operating pressure of the boom cylinder; 상기 버킷실린더에 형성되어 상기 버킷실린더의 작동압력을 검출하는 제 2 센서;A second sensor formed in the bucket cylinder to detect an operating pressure of the bucket cylinder; 장비의 주행속도를 검출하도록 설치되는 제 3 센서;A third sensor installed to detect a traveling speed of the equipment; 상기 컨트롤밸브에 형성되며, 상기 붐실린더 및 버킷실린더에 설정된 압력이상의 부하가 발생되는 경우 작동압을 유압탱크로 귀환시키는 가변 릴리프밸브;A variable relief valve formed in the control valve and returning the operating pressure to the hydraulic tank when a load greater than the pressure set in the boom cylinder and the bucket cylinder is generated; 상기 가변 릴리프밸브의 토출유로에 소정신호 입력에 따라 절환되도록 설치되며, 상기 붐실린더 및 버킷실린더에 설정된 압력이상의 부하발생시 절환되어 상기 가변 릴리프밸브의 설정압력을 증가시키는 솔레노이드밸브;A solenoid valve installed to be switched according to a predetermined signal input in the discharge flow path of the variable relief valve and switched when a load greater than the pressure set in the boom cylinder and the bucket cylinder is generated to increase the set pressure of the variable relief valve; 운전자에 의해 상기 가변 릴리프밸브 제어기능을 선택하는 선택스위치; 및A selection switch for selecting the variable relief valve control function by a driver; And 상기 선택스위치 및 각 센서들로 부터 입력되는 검출신호에 따라 상기 가변 릴리프밸브에 소정신호를 인가하는 컨트롤러를 더 포함하여 구성됨을 특징으로 하는 건설기계의 작업장치용 승압장치.And a controller for applying a predetermined signal to the variable relief valve according to the detection signal input from the selection switch and the respective sensors.
KR1019980041230A 1998-09-30 1998-09-30 Booster for work equipment of construction machine KR20000021940A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100455056B1 (en) * 2000-12-14 2004-11-08 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 hydraulic circuit for construction heavy equipment
KR100610881B1 (en) * 2004-04-29 2006-08-11 주식회사수산중공업 An Oil Control Device of Construction Machine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR920008285A (en) * 1990-10-29 1992-05-27 김연수 Power-up control device of heavy equipment working device and control method
KR920010084A (en) * 1990-11-01 1992-06-26 김연수 Optimum working flow control device of excavator and its control method
JPH06313403A (en) * 1993-04-27 1994-11-08 Yutani Heavy Ind Ltd Hydraulic circuit of construction machine
JPH09151486A (en) * 1995-11-22 1997-06-10 Furukawa Co Ltd Overload protection device for attachment
KR100240086B1 (en) * 1997-03-22 2000-01-15 토니헬 Automatic fluid pressure intensifying apparatus and method of a hydraulic travelling device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR920008285A (en) * 1990-10-29 1992-05-27 김연수 Power-up control device of heavy equipment working device and control method
KR920010084A (en) * 1990-11-01 1992-06-26 김연수 Optimum working flow control device of excavator and its control method
JPH06313403A (en) * 1993-04-27 1994-11-08 Yutani Heavy Ind Ltd Hydraulic circuit of construction machine
JPH09151486A (en) * 1995-11-22 1997-06-10 Furukawa Co Ltd Overload protection device for attachment
KR100240086B1 (en) * 1997-03-22 2000-01-15 토니헬 Automatic fluid pressure intensifying apparatus and method of a hydraulic travelling device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100455056B1 (en) * 2000-12-14 2004-11-08 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 hydraulic circuit for construction heavy equipment
KR100610881B1 (en) * 2004-04-29 2006-08-11 주식회사수산중공업 An Oil Control Device of Construction Machine

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