KR200389671Y1 - Apparatus for reducing shock on the bucket of wheel typed loader in float down mode - Google Patents
Apparatus for reducing shock on the bucket of wheel typed loader in float down mode Download PDFInfo
- Publication number
- KR200389671Y1 KR200389671Y1 KR20-1999-0012340U KR19990012340U KR200389671Y1 KR 200389671 Y1 KR200389671 Y1 KR 200389671Y1 KR 19990012340 U KR19990012340 U KR 19990012340U KR 200389671 Y1 KR200389671 Y1 KR 200389671Y1
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- bucket
- boom
- control valve
- cylinder
- float
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- 230000035939 shock Effects 0.000 title 1
- 239000003921 oil Substances 0.000 claims description 17
- 238000001514 detection method Methods 0.000 claims description 10
- 239000010720 hydraulic oil Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 description 7
- 230000003111 delayed effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
- E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
- E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
-
- 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
- E02F9/2282—Systems using center bypass type changeover valves
-
- 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)
- Mechanical Engineering (AREA)
- Operation Control Of Excavators (AREA)
Abstract
본 고안은 휠로더의 붐하강 충격저감장치에 관한 것으로, 특히 휠로더의 버켓에 하중체를 적재한 상태에서 플로트다운 모드로 버켓 및 붐을 하강시킬 때, 붐제어스풀(2)이 플로트위치에 있음을 감지한 플로트위치 감지센서(12)의 감지신호와,버켓의 적재하중을 감지한 버켓하중 감지수단의 감지신호에 의해 제어밸브(7) 에 전원이 인가되고, 이에 따라 제어밸브(7)가 절환되어 상기 붐실린더(2)의 압유를 탱크로 드레인시키는 유로(6)를 교축시킴으로써 붐하강속도를 감소시켜 붐하강 충격을 저감하는 것이다.The present invention relates to an impact reduction device for lowering the boom of a wheel loader. In particular, when the bucket and the boom are lowered in a float down mode while a load is loaded on the bucket of the wheel loader, the boom control spool (2) is in a float position. Power is applied to the control valve 7 by the detected signal of the detected float position sensor 12 and the detected signal of the bucket load sensing means that detects the loading load of the bucket, so that the control valve 7 is switched. By throttling the flow path 6 for draining the pressure oil of the boom cylinder 2 to the tank, the boom lowering speed is reduced to reduce the boom lowering impact.
Description
본 고안은 휠로더의 붐하강 충격저감장치에 관한 것으로, 특히 부움이 자중에 의해 하강하는 모드, 소위 플로트다운 모드(FLOAT DOWN mode)에서 붐이 자중으로 하강할 때 지면과의 충격을 저감하는 장치에 관한 것이다.The present invention relates to a boom lowering impact reduction device of a wheel loader, and more particularly to a device that reduces the impact with the ground when the boom descends to its own weight in a mode in which the boom descends by its own weight, a so-called float down mode. It is about.
건설현장에서 버켓으로 중량물을 운반 또는 들어올리거나 내리는 데 사용되는 장비인 휠로더에서 붐하강동작을 제어하는 방식에는 2가지 방식이 있다. 즉 한가지는 유압펌프에서 붐실린더의 헤드측(붐이 하강하는 방향)으로 공급되는 압유의 유량을 제어함으로써 붐의 하강속도를 제어하는 소위 붐다운(BOOM DOWN)방식이고, 다른 방식은 소위 플로트 다운(FLOAT DOWN)방식으로서, 붐실린더의 헤드측 압유와 로드측 압유를 모두 드레인시킴으로써 버켓과 붐의 자중에 의해 하강하도록 제어하는 방식이다.There are two ways to control the boom lowering action in the wheel loader, which is the equipment used for transporting, lifting or lowering heavy items from the construction site to the bucket. One is the so-called boom down method that controls the lowering speed of the boom by controlling the flow rate of the hydraulic oil supplied from the hydraulic pump to the head side of the boom cylinder (the direction in which the boom descends), and the other method is the so-called float down method. As a (FLOAT DOWN) method, the head side oil pressure and the rod pressure oil pressure of the boom cylinder are drained so as to be lowered by the weight of the bucket and the boom.
상기 붐다운방식은 붐실린더에 공급·배출되는 압유의 량을 조절하여 붐하강속도를 제어하는 방식이므로 붐 또는 버켓의 미세조작이나 붐으로 작업대상물에 큰 힘을 가할 필요가 있는 경우에 사용되고, 상기 플로트다운 방식은 붐하강시 붐실린더의 로드측 및 헤드측 양쪽을 모두 탱크로 연통시켜 붐실린더 내의 압유를 모두 드레인시키므로, 상기 붐다운방식에 비하여 하강속도가 빨라서 상차 작업후 버켓을 다시 지면으로 신속하게 내릴 필요가 있는 경우에 적합하고, 또한 이 플로트다운 모드에서는 작업자가 버켓을 하강시키는 방향으로 계속 밀고 있더라도 버켓이 자중 및 붐자중에 의해 하강하다가 지면에 닿게 되면 저절로 정지하게 되므로 조작이 편리하다는 장점이 있다. The boom-down method is used to control the boom lowering speed by adjusting the amount of pressure oil supplied to and discharged from the boom cylinder, so it is used when it is necessary to apply a large force to the work object by the micro-manipulation of the boom or the bucket or the boom. The float down method connects both the rod side and the head side of the boom cylinder to the tank when the boom is lowered, and drains all the pressure oil in the boom cylinder. Therefore, the lowering speed is faster than that of the boom down method. It is suitable for the case that needs to be lowered, and in this float down mode, even if the operator keeps pushing the bucket in the downward direction, the bucket is lowered by its own weight and boom weight, and stops on its own when it touches the ground. There is this.
그리고 상기 플로트 모드로 버켓을 지면에 닿게 한 상태에서 주행을 하면 버켓은 지면을 계속 누르고 있는 상태에서 이동하게 되므로 평탄작업도 가능하다.In addition, if the bucket is driven while the bucket is in contact with the ground in the float mode, the bucket is moved while the ground is kept pressed, so that flat work is possible.
그런데 상기 플로트 모드로 버켓을 하강시킬 때 버켓에 하중이 가해지지 않을 때에는 문제가 없으나, 중량체를 적재한 상태에서 버켓을 플로트모드로 하강시킬 때에는 그 하중 때문에 지면에 닿을 때 충격이 큰 단점이 있다.However, when the bucket is lowered in the float mode, there is no problem when the load is not applied to the bucket, but when the bucket is lowered in the float mode while the heavy body is loaded, the impact is great when it comes in contact with the ground due to the load. .
본 고안은 상기한 바와 같은 문제점을 해소하기 위해 제안된 것으로서, 휠로더에서 버켓이 중량체를 적재한 상태에서 플로트 다운 모드로 하강할 때, 버켓의 하강속도를 지연시켜 지면과 맞닿을 때 그 지면과의 충격을 줄여주는 휠로더 붐하강 충격저감장치를 제공함에 목적이 있다.The present invention is proposed to solve the problems as described above, when the bucket in the wheel loader descends to the float down mode in the state of loading the heavy body, delayed the falling speed of the bucket when the contact with the ground It is an object of the present invention to provide a wheel loader boom lowering impact reduction device that reduces the impact of a car.
상기 목적을 달성하기 위한 본 고안은 휠로더의 버켓에 하중체를 적재한 상태에서 플로트다운 모드로 버켓 및 붐을 하강시킬 때, 그 버켓의 적재하중을 감지한 버켓하중 감지용수단의 감지신호와, 붐제어스풀이 플로트위치에 있음을 감지한 플로트위치 감지센서의 감지신호에 의해 솔레노이드 제어밸브에 전원이 인가되고, 이에 따라 제어밸브가 절환되어 상기 붐실린더(2)의 압유를 탱크로 드레인시키는 유로를 교축시킴으로써 붐하강속도를 감소시킨다.The present invention for achieving the above object is when the bucket and the boom in the down load mode in the state of loading the load on the bucket of the wheel loader, the detection signal of the bucket load detection means for detecting the load load of the bucket, A flow path for supplying power to the solenoid control valve by the detection signal of the float position detecting sensor that detects that the boom control spool is in the float position, thereby switching the control valve to drain the pressure oil of the boom cylinder 2 to the tank. Reduce the boom lowering speed by throttling.
이러한 구조로 이루어진 본 고안은 트럭에 적재된 중량체를 버켓에 실어 내릴 때, 붐의 하강속도가 감소되므로 버켓이 하강하여 지면에 닿을 때 지면과의 충격을 감소시키게 된다.The present invention having such a structure reduces the impact of the ground when the bucket is lowered and touches the ground because the lowering speed of the boom is reduced when loading the weight loaded on the truck into the bucket.
이하 본 고안의 실시예를 첨부도면에 따라 자세히 설명한다.Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
도 1은 본 고안에 따른 장치를 나타낸 유압회로도이다. 메인펌프(1)에서 토출된 압유는 붐제어스풀(2)과 버켓제어스풀(3)을 통하여 각각 붐실린더(4)와 버켓실린더(5)에 공급되게 되어 있다.1 is a hydraulic circuit diagram showing a device according to the present invention. The pressure oil discharged from the main pump 1 is supplied to the boom cylinder 4 and the bucket cylinder 5 through the boom control spool 2 and the bucket control spool 3, respectively.
상기 붐제어스풀(2)과 붐실린더(4)의 헤드측 체임버(4a)을 서로 연결시키는 제1압유라인(6)에는 솔레노이드 제어밸브(7)가 설치된다. 이 솔레노이드 제어밸브(7)의 솔레노이드부(7a)는 릴레이스위치(8)를 통하여 전원에 연결되어 있다. 따라서 이 제어밸브(7)의 솔레노이드부(7a)에 전원이 인가되면 제어밸브(7)는 오리피스통로(7b)측으로 절환되어 상기 제1압유라인(6)을 통하여 드레인되는 압유의 량을 감소시킴으로써 붐하강의 하강속도를 늦추게 된다.A solenoid control valve 7 is installed in the first pressure oil line 6 which connects the boom control spool 2 and the head side chamber 4a of the boom cylinder 4 to each other. The solenoid portion 7a of the solenoid control valve 7 is connected to the power supply via the relay switch 8. Therefore, when power is applied to the solenoid portion 7a of the control valve 7, the control valve 7 is switched to the orifice passage 7b to reduce the amount of pressure oil drained through the first pressure oil line 6. This slows down the descent of the boom.
그리고 상기 솔레노이드 제어밸브(7)의 솔레노이드부(7a)쪽으로 전원을 공급하는 전선에는 상기 버켓에 중량체가 적재된 경우에만 온작동하여 제어밸브(7)의 솔레노이드부(7a)에 전원을 공급하는 버켓하중 감지수단(9)이 연결되어 있다. In addition, the electric wire for supplying power to the solenoid portion 7a of the solenoid control valve 7 is turned on only when a heavy body is loaded in the bucket to supply power to the solenoid portion 7a of the control valve 7. The load sensing means 9 is connected.
본 실시예에서는 상기 버켓하중 감지수단이 압력스위치(9)로 구성되고, 이 압력스위치(9)는 버켓실린더(5)의 로드측 체임버(5a)와 버켓제어스풀(3)의 출구포트를 연결하는 제2압유라인(10)에서 분기된 파이롯라인(11)에 연결되어 이 파이롯라인(11)에 일정한 압력이상이 가해지면 온(on)작동하여 상기 제어밸브(7)의 솔레노이드부(7a)에 전원을 인가하게 된다.In this embodiment, the bucket load sensing means is composed of a pressure switch 9, which is connected to the rod side chamber 5a of the bucket cylinder 5 and the outlet port of the bucket control spool 3. The solenoid portion of the control valve 7 is connected to the pilot line 11 branched from the second pressure oil line 10 so as to be turned on when a predetermined pressure or more is applied to the pilot line 11. Power is applied to 7a.
또한 상기 솔레노이드 제어밸브(7)의 솔레노이드부(7a)쪽으로 전원을 공급하는 전선에는 상기 붐제어스풀(2)이 플로트다운 모드에 위치한 경우 감지작동하여 솔레노이드 제어밸브(7)의 솔레노이드부(7a)에 감지신호를 보내는 플로트위치 감지센서(12)가 상기 압력스위치(9)와 직렬로 연결되어 있다.In addition, the electric wire for supplying power to the solenoid portion 7a of the solenoid control valve 7 detects when the boom control spool 2 is located in the float down mode and operates the solenoid portion 7a of the solenoid control valve 7. The float position sensor 12 which transmits a detection signal to the pressure switch 9 is connected in series.
따라서 상기 붐제어스풀(3)을 플로트다운 모드에 두고, 동시에 버켓에 하중체가 적재되어 상기 파이롯라인(11)에 파이롯신호압이 가해지는 경우에, 상기 압력스위치(9)는 온작동하여 상기 제어밸브(7)의 솔레노이드부(7a)로 전원을 공급함으로써 솔레노이드부(7a)를 작동시키고, 이에 따라 제어밸브(7)가 오리피스유로(7b)측으로 방향절환하게 된다. 이 경우 붐은 자중과 버켓에 적재된 하중체의 무게 때문에 하강하는 데, 이 때 붐실린더(4)의 헤드측 체임버(4a)에서 제1압유라인(6)을 통하여 탱크쪽으로 드레인되는 압유의 량은 제어밸브(7)의 오리피스측 유로(7b)를 통하여 감소하므로 붐의 하강속도가 지연된다. 따라서 버켓이 지면에 닿을 때의 충격이 감소되는 것이다.Accordingly, when the boom control spool 3 is placed in the float down mode and at the same time a load is loaded in the bucket and the pilot signal pressure is applied to the pilot line 11, the pressure switch 9 is turned on. The solenoid portion 7a is operated by supplying power to the solenoid portion 7a of the control valve 7 so that the control valve 7 is diverted to the orifice flow path 7b. In this case, the boom is lowered due to its own weight and the weight of the load loaded on the bucket. At this time, the pressure of the hydraulic oil drained from the head side chamber 4a of the boom cylinder 4 to the tank through the first pressure oil line 6 Since the amount decreases through the orifice side flow path 7b of the control valve 7, the lowering speed of the boom is delayed. Therefore, the impact when the bucket touches the ground is reduced.
반면, 상기 버켓에 중량체를 적재하지 않고, 상기 붐을 플로트다운 모드로 하강시키더라도, 상기 버켓실린더(5)의 로드측 체임버(5a)에 연결된 압유라인(10)의 라인압이 낮으므로, 이 압유라인(10)에서 분기된 파이롯라인(11)을 통하여 상기 압력스위치(9)에 가해지는 파이롯신호압도 설정치보다 낮게 되어 상기 압력스위치(9)는 오프(off)된다. On the other hand, even if the boom is lowered in the float down mode without loading a heavy body in the bucket, the line pressure of the oil pressure line 10 connected to the rod side chamber 5a of the bucket cylinder 5 is low. In addition, the pilot signal pressure applied to the pressure switch 9 through the pilot line 11 branched from the oil pressure line 10 is also lower than the set value so that the pressure switch 9 is turned off.
한편, 상기 압력스위치(9)과 전원을 연결하는 상기 전선에는 선택스위치(13)를 연결설치하여 이 선택스위치(13)를 온/오프시킴으로써 본 고안에 따른 붐하강 충격저감장치를 작동시키거나 작동시키지 않게 할 수도 있다. On the other hand, by connecting the selection switch 13 to the wire for connecting the pressure switch 9 and the power supply to operate the boom lowering impact reduction device according to the present invention by turning on / off the selection switch 13 You can also disable it.
이러한 구조로 이루어진 본 고안의 장치의 작동을 아래에서 설명한다.The operation of the device of the present invention having such a structure will be described below.
버켓에 하중체가 적재된 상태에서 붐을 플로트다운 모드로 하강시키는 경우, 즉 붐을 자중으로 하강시키되, 지면에 맞닿을 때 그 충격이 크지 않게 하고자 하는 경우에는, 우선 선택스위치(13)를 온시키고,조이스틱레버를 밀어서 붐제어스풀(2)을 플로트다운 모드로 절환시키면, 플로트다운 위치감지센서(12)가 감지작동하여 감지신호를 보내고, 동시에 버켓의 적재하중에 따른 파이롯라인(11)의 파이롯신압에 의해 압력스위치(9)가 온된다. When the boom is lowered in the float down mode while the load is loaded in the bucket, that is, when the boom is lowered by its own weight and the impact is not so large when it comes into contact with the ground, the selector switch 13 is first turned on. When the boom control spool 2 is switched to the float down mode by pushing the joystick lever, the float down position sensor 12 detects and sends a detection signal, and at the same time, the pilot line 11 The pressure switch 9 is turned on by the pilot pressure.
상기와 같이 되면 전원은 상기 제어밸브(7)의 솔레노이드부(7a)에는 전원이 인가되어 제어밸브(7)가 오리피스측 유로(7b)로 절환되고, 이에 따라 붐실린더(4)의 헤드측 체임버(4a)에서 탱크로 드레인되는 유량은 감소하므로 붐하강속도가 지연되어 버켓이 지면에 닿게 되더라도 그 충격이 저감되게 된다.In this case, power is applied to the solenoid portion 7a of the control valve 7 so that the control valve 7 is switched to the orifice side flow path 7b, and accordingly, the head side chamber of the boom cylinder 4 is provided. Since the flow rate drained to the tank in (4a) decreases, the impact is reduced even if the boom lowering speed is delayed and the bucket touches the ground.
반면, 버켓에 중량체를 적재하지 않고 붐을 플로트다운 모드로 신속하게 하강시키는 경우에는, 버켓실린더(5)의 로드측 체임버(5a)에서 분기된 파이롯라인(11)의 파이롯압이 낮으므로 상기 압력스위치(9)가 오프되어 제어밸브(7)에 전원이 차단되어 제어밸브(7)를 절환시키지 않고, 이에 따라 붐실린더(4)의 헤드측 체임버(4a)의 압유는 그대로 드레인되어 붐하강속도가 상대적으로 빨라져 붐이 신속하게 하강하게 되는 것이다.On the other hand, in the case of rapidly lowering the boom in the float down mode without loading a heavy body into the bucket, the pilot pressure of the pilot line 11 branched from the rod side chamber 5a of the bucket cylinder 5 is low. The pressure switch 9 is turned off and the power is cut off from the control valve 7 so that the control valve 7 is not switched. Accordingly, the pressure oil of the head side chamber 4a of the boom cylinder 4 is drained as it is. The descent speed is relatively high, causing the boom to descend quickly.
이상에서 설명한 바와 같이 본 고안의 장치에 따르면, 붐을 플로트다운모드로 하강시킬 때, 버켓의 적재하중에 따라 붐하강속도가 자동으로 조절되므로, 버켓이 지면에 닿을 때 지면과의 충격이 감소되어 작업성을 향상시킬 수 있게 된다.As described above, according to the device of the present invention, when lowering the boom in the float down mode, the boom lowering speed is automatically adjusted according to the loading load of the bucket, so that the impact to the ground when the bucket touches the ground is reduced Workability can be improved.
도 1 은 본 고안에 따른 휠로더의 붐하강 충격저감장치를 나타낸 유압회로도이다.1 is a hydraulic circuit diagram illustrating a boom lowering impact reduction device of a wheel loader according to the present invention.
* 도면의 주요부분에 대한 부호의 설명 * Explanation of symbols on main parts of drawing
1: 메인펌프 2: 붐제어스풀1: main pump 2: boom control spool
3: 버켓제어스풀 4: 붐실린더3: bucket control spool 4: boom cylinder
4a: 헤드측 체임버 5: 버켓실린더4a: head side chamber 5: bucket cylinder
5a: 로드측 체임버 6: 제1압유라인5a: Rod side chamber 6: 1st oil pressure line
7: 제어밸브 7a: 솔레노이드부7: control valve 7a: solenoid part
7b: 오리피스측 유로 8: 릴레이스위치7b: Orifice side flow path 8: relay switch
9: 압력스위치 10: 제2압유라인9: pressure switch 10: second pressure oil line
11: 파이롯라인 12: 플로트 다운모드 위치감지센서11: Pilot Line 12: Float Down Mode Position Sensor
13: 선택스위치13: selector switch
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20-1999-0012340U KR200389671Y1 (en) | 1999-06-30 | 1999-06-30 | Apparatus for reducing shock on the bucket of wheel typed loader in float down mode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20-1999-0012340U KR200389671Y1 (en) | 1999-06-30 | 1999-06-30 | Apparatus for reducing shock on the bucket of wheel typed loader in float down mode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20010001834U KR20010001834U (en) | 2001-01-26 |
| KR200389671Y1 true KR200389671Y1 (en) | 2005-07-14 |
Family
ID=43690938
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR20-1999-0012340U Expired - Lifetime KR200389671Y1 (en) | 1999-06-30 | 1999-06-30 | Apparatus for reducing shock on the bucket of wheel typed loader in float down mode |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR200389671Y1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101324917B1 (en) | 2006-11-30 | 2013-11-01 | 두산인프라코어 주식회사 | Device for controlling Boom of Excavator |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100953809B1 (en) * | 2002-12-27 | 2010-04-21 | 두산인프라코어 주식회사 | Boom Buffer of Wheel Loader |
| CN104968863B (en) * | 2013-02-05 | 2017-10-10 | 现代建设机械（株） | Construction equipment |
| CN119266331A (en) * | 2024-11-07 | 2025-01-07 | 三一重机有限公司 | A hydraulic control system and method for horizontal push loading of a front shovel excavator and a front shovel excavator |
-
1999
- 1999-06-30 KR KR20-1999-0012340U patent/KR200389671Y1/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101324917B1 (en) | 2006-11-30 | 2013-11-01 | 두산인프라코어 주식회사 | Device for controlling Boom of Excavator |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20010001834U (en) | 2001-01-26 |
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