KR200333340Y1 - Boom emergency lowering device of excavator - Google Patents

Abstract

When the engine driving is stopped, the boom located at a certain height from the ground can be lowered to the emergency by utilizing the operating pressure of the hydraulic cylinder for driving the boom when descending to the ground to secure the safety of the equipment.

According to a preferred embodiment, an engine, a first hydraulic pump and a second hydraulic pump connected to and driven by the engine, and a boom driving hydraulic cylinder connected to the first hydraulic pump to rotate the boom within a predetermined stroke when driven. And a direction control valve installed between the first hydraulic pump and the boom driving hydraulic cylinder and controlling the flow direction of the hydraulic oil discharged from the first hydraulic pump when driven by the pilot signal pressure supply from the second hydraulic pump. And a pilot valve installed between the second hydraulic pump and the directional control valve to control the pilot signal pressure for driving the directional control valve during operation, and installed between the pilot valve and the boom driving hydraulic cylinder to stop the engine driving. When operating the directional control valve at the operating pressure of the hydraulic cylinder for the boom drive by the contraction of the hydraulic cylinder for the boom drive It provides an boom emergency lowering device of the excavator, characterized in that it is provided with an operation means for lowering the boom relative to the ground.

As a result, when the engine driving is stopped and the boom located at a certain height from the ground is lowered to the ground to secure the safety of the equipment, the process of accumulating energy by utilizing the operating pressure of the hydraulic cylinder for driving the boom is unnecessary. It has one advantage to prevent waste of energy.

Description

Excavator boom emergency lowering device

The present invention relates to an boom emergency lowering device of an excavator, and more particularly, the operation of the hydraulic cylinder for driving the boom when the boom is lowered to the ground in order to ensure the safety of the equipment when the boom located at a predetermined height from the ground while the engine driving is stopped It relates to an boom emergency lowering device of an excavator that can use the pressure to lower the boom to an emergency.

As schematically shown in FIG. 1, the boom emergency lowering device of an excavator according to the prior art includes an engine 1, a first hydraulic pump 2 and a second hydraulic pump connected to and driven by the engine 1. (3), a boom driving hydraulic cylinder (5) connected to the first hydraulic pump (2) described above and rotating the boom (4) in a predetermined stroke during driving, and the first hydraulic pump (2) described above; Directional control valves installed between the hydraulic cylinders 5 to control the flow direction of the hydraulic oil discharged from the aforementioned first hydraulic pump 2 when driven by the pilot signal pressure supply discharged from the aforementioned second hydraulic pump 3. (6) and an operating lever (7) installed between the second hydraulic pump (3) and the direction control valve (6) to control the pilot signal pressure for driving the above-mentioned direction control valve (6) during operation; In the emergency situation in which the driving of the engine 1 described above is stopped between the above-described second hydraulic pump 3 and the operation lever 7. Further included is an accumulator (8) for storing the pilot signal pressure for driving the direction control valve 6.

Reference numeral 9 denotes a relief valve for protecting the related components by draining the tank when an overload occurs above a predetermined operating pressure set in the hydraulic circuit, and 10 indicates that the pilot signal pressure discharged from the above-described second hydraulic pump 3 is reversed. A check valve for preventing, 11 is an arm rotatably connected to the other end of the boom 4 described above, 12 is a bucket rotatably connected to the other end of the arm 11 described above.

The boom emergency lowering device of the excavator configured as described above stops the driving of the engine 1 in the state where the above-described boom 4 is located at a predetermined height from the ground due to the expansion of the above-described boom driving hydraulic cylinder 5. Accumulator accumulating the pilot signal pressure discharged from the above-mentioned second hydraulic pump 3 when driving the engine 1 when the above-mentioned boom 4 should be lowered to the ground side in order to secure the safety of the equipment. The pilot signal pressure from (8) is supplied to the above-mentioned direction control valve 6 by the operation of the operation lever 7 described above and is switched to the left in the drawing, so that the above-mentioned boom driving hydraulic cylinder 5 The working pressure from the large chamber is returned to the tank T via the directional control valve 6 that has been switched.

Therefore, even when the driving of the engine 1 above is stopped while the above-described boom 4 is located at a predetermined height from the ground, the above-mentioned boom 4 is utilized by using the pilot signal pressure accumulated in the above-described accumulator 8. Can be lowered to the ground.

However, the problem that the pilot signal pressure discharged from the above-described second hydraulic pump 3 is separately accumulated in the above-described accumulator 8 and then used is used to cause waste of energy, and hydraulic oil leaks in various valve portions of the hydraulic circuit. As the loss of energy (LOSS) caused by the (LEAK) is left for a long time when the state of raising the above-mentioned boom 4 to a predetermined height from the ground, the above-described boom (4) cannot be lowered emergencyly, There is a problem that a safety accident can occur.

Accordingly, an object of the present invention is to accumulate energy by utilizing the working pressure of the boom driving hydraulic cylinder when the boom is lowered to the ground in order to secure the safety of the equipment when the engine driving is stopped. It is to provide an boom emergency lowering device of the excavator to prevent the waste of energy is unnecessary.

1 is a hydraulic circuit diagram of the boom emergency lowering device of the excavator according to the prior art,

2 is a hydraulic circuit diagram of the boom emergency lowering device of the excavator according to an embodiment of the present invention.

* Explanation of symbols used in the main part of the drawing

1: engine

2: first hydraulic pump

3: second hydraulic pump

4: boom

5: Hydraulic cylinder for boom drive

6: directional control valve

7: Operation lever

13: power switch

14: solenoid valve

An object of the present invention described above is for driving a boom for driving a boom within a predetermined stroke when connected to the engine, a first hydraulic pump and a second hydraulic pump connected to and driven by the engine, and the first hydraulic pump when driven. Directional control is provided between the hydraulic cylinder, the first hydraulic pump and the boom driving hydraulic cylinder and controls the flow direction of the hydraulic oil discharged from the first hydraulic pump when driven by the pilot signal pressure supply from the second hydraulic pump A pilot valve installed between the valve, the second hydraulic pump and the directional control valve to control the pilot signal pressure for driving the directional control valve during operation, and installed between the pilot valve and the boom driving hydraulic cylinder. When the drive stops, the directional control valve is driven by the operating pressure of the boom driving hydraulic cylinder, so that the boom driving hydraulic cylinder The is achieved by the boom provide an emergency descent device of the excavator, characterized by configured by comprising a processing means for lowering to the ground.

Preferably, the operation means is switched according to the power switch is turned off when the boom is lowered with respect to the ground while the engine driving is stopped, and the electric signal applied from the power switch, the boom drive And a solenoid valve for supplying a part of the working pressure from the large chamber of the hydraulic cylinder to a working pressure for switching the directional control valve and lowering the boom by contraction of the boom driving hydraulic cylinder.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are not intended to limit the technical scope of the present invention.

2 is a hydraulic circuit diagram of the boom emergency lowering device of the excavator according to an embodiment of the present invention.

As shown in the figure, the engine 1, the first hydraulic pump 2 and the second hydraulic pump 3 connected to and driven by the engine 1, and the first hydraulic pump 2 described above. The second hydraulic pump is installed between the hydraulic cylinder for driving the boom (5) and the first hydraulic pump (2) and the hydraulic cylinder (5), which is connected to rotate the boom (4) in a predetermined stroke when driving. (3) the direction control valve 6 for controlling the flow direction of the hydraulic oil discharged from the above-mentioned first hydraulic pump 2 when driven by the pilot signal pressure supply from the above, and the above-mentioned second hydraulic pump 3 and the direction An operating lever 7 installed between the control valves 6 for controlling the pilot signal pressure for driving the above-mentioned direction control valve 6 during operation, and a tank when an overload occurs above a predetermined operating pressure initially set inside the hydraulic circuit. A relief valve 9 for draining and protecting related parts, and a pile discharged from the above-described second hydraulic pump 3 The configuration of the check valve 10 to prevent the reverse flow of the signal pressure is applied in the same manner as shown in Figure 1, so the detailed description thereof will be omitted, and the duplicated reference numerals are the same.

Therefore, according to a preferred embodiment of the present invention, a part of the operating pressure of the above-described boom driving hydraulic cylinder (5) between the above-described operating lever (7) and the boom driving hydraulic cylinder (5) the direction control valve ( 6) is supplied at the operating pressure for switching, and operation means for lowering the above-described boom 4 with respect to the ground in the state where the driving of the engine 1 is stopped is provided. At this time, the above-mentioned operation means is applied from the power switch 13, which is turned off when the above-mentioned boom 4 is lowered with respect to the ground while the driving of the engine 1 is stopped and from the power switch 13. Switched in accordance with the electrical signal to be supplied a portion of the operating pressure from the large chamber (5a) of the above-described boom driving hydraulic cylinder (5) to the operating pressure for switching the above-mentioned directional control valve (6) for the boom driving The solenoid valve 14 which lowers the above-mentioned boom 4 by contraction of the hydraulic cylinder 5 is provided.

Referring to the method of using the boom emergency lowering device of the excavator according to the embodiment of the present invention is configured as follows.

The first hydraulic pump 2 and the second hydraulic pump 3 described above are driven by driving the engine 1 described above, and from the second hydraulic pump 3 described above due to the operation of the operation lever 7 described above. The pilot signal pressure discharged is supplied to the above-mentioned direction control valve 6 to switch the internal spool in the left or right direction, whereby the operating pressure discharged from the above-described first hydraulic pump 2 is the position-controlled direction control. As the boom driving hydraulic cylinder 5 is supplied via the valve 6, the boom 4 is rotated within a predetermined stroke due to the driving of the boom driving hydraulic cylinder 5 described above. It is possible to perform a predetermined operation.

At this time, the above-mentioned boom 4 is stopped in the state in which the above-described boom 4 is located at a predetermined height from the ground due to the extension of the above-described boom driving hydraulic cylinder 5, so that the above-mentioned boom is secured to secure the equipment. In the case where it is necessary to lower (4) to the ground side, an electrical signal according to the user turning off the above-mentioned power switch 13 is applied to the valve spring 14a of the solenoid valve 14 described above, and the internal spline is released. Switch to the left in the drawing.

Therefore, the above-mentioned solenoid valve 14 and the above-mentioned directional control valve 6 in which the part of the operating pressure from the large chamber 5a of the above-mentioned boom drive hydraulic cylinder 5 are switched are leftward on the drawing. It is supplied to the right port of the above-mentioned directional control valve 6 via the operating lever 7 which is operated to be switched, and switches the internal spool to the left side on the drawing. Therefore, as the operating pressure from the large chamber 5a of the above-described boom driving hydraulic cylinder 5 is returned to the tank T via the position-controlled direction control valve 6, the above-described boom 4 Is to be able to emergencyly lower the ground even when the driving of the engine (1) described above is stopped.

As described above, according to a preferred embodiment of the present invention, the operating pressure of the hydraulic cylinder for driving the boom when lowering the ground to secure the equipment of the boom located at a predetermined height from the ground while the engine driving is stopped Therefore, there is no need for a process of accumulating additional energy, thereby preventing the waste of energy.

Claims (1)

engine; A first hydraulic pump and a second hydraulic pump connected to and driven by the engine; A boom driving hydraulic cylinder connected to the first hydraulic pump to rotate the boom within a predetermined stroke range when driven; A direction control valve installed between the first hydraulic pump and the boom driving hydraulic cylinder and controlling a flow direction of the hydraulic oil discharged from the first hydraulic pump when driven by a pilot signal pressure supply from the second hydraulic pump; A pilot valve installed between the second hydraulic pump and a direction control valve to control a pilot signal pressure for driving the direction control valve during operation; A power switch to turn off the power when the boom is lowered with respect to the ground while the engine driving is stopped; And It is installed between the second hydraulic pump and the boom driving hydraulic cylinder, is switched by the electrical signal applied from the power switch and the operating pressure from the large chamber of the boom driving hydraulic cylinder for switching the direction control valve And a solenoid valve for lowering the boom by contraction of the hydraulic cylinder for driving the boom by supplying the working pressure to the boom emergency lowering device of the excavator.