KR20100072721A - Apparatus for driving working device of construction machinery - Google Patents

Abstract

PURPOSE: A device for driving a working device for construction machinery is provided to store energy using a cylinder and an accumulator, and to reduce energy consumption by driving a working device using the stored energy. CONSTITUTION: A device for driving a working device for construction machinery comprises a working cylinder(10), a cylinder(20) for compensating deadweight, and an accumulator(30). The working cylinder powers a working device(2) and comprises an ascent chamber and a descent chamber. Hydraulic fluid discharged from a pump is supplied to the ascent chamber. And the hydraulic fluid is supplied to the descent chamber and then is supplied to the cylinder. The accumulator supplies the hydraulic fluid to the ascent chamber of the cylinder.

Description

Working device drive of construction machine {APPARATUS FOR DRIVING WORKING DEVICE OF CONSTRUCTION MACHINERY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction machinery such as excavators and the like, and more particularly, to a work machine drive of a construction machine for efficiently driving work machines such as booms, arms and buckets.

In general, the working machine of a construction machine such as an excavator consists of a boom, an arm and a bucket. The boom, arm and bucket are driven by a hydraulic cylinder to perform work such as excavation work.

The boom is rotatably installed in the upper pivot body in the vertical direction, the arm is rotatably installed in the vertical direction in the boom, and the bucket is installed in the arm to pivot in the vertical direction. Thus, a boom cylinder for driving the boom must support the load of the arms and the bucket as well as the weight of the boom itself.

Therefore, when the boom cylinder is extended to raise the boom, most energy is consumed. On the other hand, when the boom is lowered, the load of the boom, the arm and the bucket raises the pressure of the raising chamber of the boom cylinder very high. In this way, the pressure formed in the upward chamber is lost by thermal energy while passing through an orifice or the like for preventing a sudden drop of the boom.

Recently, however, studies are being actively conducted to minimize the loss of power by using the high pressure formed in the rising chamber of the boom cylinder when the boom is lowered with the rapid increase in the oil price. One example is a flow rate regeneration method for supplying hydraulic oil in the up chamber of the boom cylinder to the down chamber of the boom cylinder when the boom is lowered. Such a flow rate regeneration method reduces the flow rate of the hydraulic oil discharged from the pump by supplying the hydraulic oil of the high pressure rising chamber to the lowering chamber, but energy can be saved, but the efficiency is very low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described point, and an object thereof is to provide a work machine driving device for a construction machine that can significantly improve fuel efficiency due to high energy regeneration efficiency.

Working machine driving device of the construction machine according to the present invention for achieving the above object is the rising chamber 11 and the lower supply line 14 is supplied with the hydraulic oil discharged from the pump 1 through the rising supply line (13). A working cylinder (10) having a lowering chamber (12) for receiving hydraulic oil discharged from the pump (1) through a), and driving up and down the work machine (2) according to the supply direction of the hydraulic oil; A self-compensation cylinder 20 having a raising chamber 21 to which hydraulic oil is supplied in a rising direction of the working machine 2 to assist the raising of the working machine 2; And the lifting chamber 21 of the self-compensating cylinder 20 is connected in communication with each other, and the lifting weight of the self-compensating cylinder 20 is increased according to the load applied by the work machine 2 to the self-compensating cylinder 20. The accumulators 30 and 130 supply hydraulic fluid supplied from the chamber 21 to accumulate or accumulate the hydraulic fluid to the raising chamber 21 of the self-weight compensation cylinder 20.

According to an embodiment of the present invention, the work machine driving device of the construction machine includes a first holding valve unit 50 for preventing the hydraulic oil of the lifting chamber 11 of the working cylinder 10 is leaked; And a second holding valve unit 60 for preventing leakage of the working oil of the lowering chamber 12 of the working cylinder 10. The accumulator 30 is configured as an accumulator 30. The work machine 2 may be a boom 2 on which an arm 3 and a bucket 4 are mounted at a tip thereof to support the load of the arm 3 and the bucket 4.

According to another embodiment of the present invention, the accumulator 130 includes a counter weight 131 installed to be elevated on the main body 6; And a lift chamber 133 connected to the lift chamber 21 of the self-weight compensation cylinder 20 so as to be in communication with the lift chamber 133. The counter weight 131 may be driven up and down according to the pressure of the lift chamber 133. It includes a pressure storage cylinder 132 installed on the counter weight 131 so as to.

According to the problem solving means described above, not only the self-compensation cylinder and the accumulator can store energy caused by the self-weight of the work machine but also drive the work machine using the stored energy, thereby providing energy to the work machine by the working cylinder. Can be reduced.

As a result, the flow rate and pressure of the hydraulic oil supplied to the working cylinder can be reduced, thereby reducing the power of the pump. Therefore, the fuel economy of the construction machinery can be significantly improved.

In addition, by the first and the second holding valve unit it is possible to prevent the hydraulic oil of the lower chamber as well as the rising chamber of the working cylinder to be leaked through the work machine control valve to further improve fuel economy.

In addition, by using the counter weight as a means for storing the energy of the working oil, it is possible to minimize the number of parts added, thereby minimizing the manufacturing cost of construction machinery.

Hereinafter, a work machine driving apparatus of a construction machine according to an embodiment of the present invention will be described in detail.

1 to 3, a work machine driving device for a construction machine according to an embodiment of the present invention includes a working cylinder 10, a weight compensation cylinder 20, an accumulator 30, first and It includes a second holding valve unit 50, 60.

The working cylinder 10 is for driving the work machine 2 in accordance with an operation signal input from the work machine operation unit, and is driven by the hydraulic oil discharged from the pump 1. The work machine 2 is a concept including a boom 2, an arm 3, and a bucket 4, but in the present embodiment, the work machine 2 will be described as an example of the boom 2, and the working cylinder ( 10, the boom cylinder 10 will be described by way of example. However, unlike the present embodiment, the work machine 2 may be various work machines depending on the type of construction machinery. That is, the work machine 2 may be an arm 3 and a bucket 4 as long as the work machine has a large weight, and may also be a work machine such as a dozer.

One end of the working cylinder 10 is rotatably coupled to the upper swinging body 5, and the other end of the rod 15 is rotatably coupled to the work machine 2. The working cylinder 10 coupled in this way is supplied with hydraulic oil discharged from the pump 1 and controlled in the flow direction by the work machine control valve 40. That is, the work machine control valve 40 is converted to one side or the other side according to the signal generated from the operation unit, and the flow direction and the flow rate of the hydraulic oil of the pump 1 are controlled by the work machine control valve 40 thus converted. It is supplied to the working cylinder 10. Then, the work machine 2 is driven up and down while the rod 15 of the working cylinder 10 is stretched.

When the weight of the work machine 2 is large, the self-compensation cylinder 20 accumulates the working oil and stores the hydraulic fluid in the form of pressure in the accumulator 30, and when the work machine 2 rises, the accumulator 30. The hydraulic oil is supplied to the working machine 2 to raise the work. Even if the flow rate and pressure of the hydraulic oil supplied to the working cylinder 10 are small by the self-weight compensation cylinder 20, the work machine 2 can be driven up.

More specifically, the self-compensation cylinder 20 is the same as the working cylinder 10, one end is rotatably installed on the upper swinging body 5, the other end of the rod 22 is the work machine (2) ) Is rotatably installed. In addition, the lifting chamber 21 of the self-weight compensation cylinder 20 is provided, the load of the work machine 2 is supported by the pressure formed in the lifting chamber 21.

On the other hand, the rod-side chamber 23 of the self-weight compensation cylinder 20 may be formed so that the rod 22 can be freely driven to the outside and air flow. That is, the self-compensation cylinder 20 stretches and contracts the rod 22 only by the pressure formed in the raising chamber 21. More specifically, a pressure of a predetermined range is formed in the lifting chamber 21, the force applied to the rod 22 is different depending on the position of the boom 2, the arm 3 and the bucket (4). The rod 22 is stretched and stretched.

The accumulator 30 is connected in communication with the rising chamber 21 of the self-compensation cylinder 20 to accumulate the hydraulic fluid of the lifting chamber 21 of the self-compensation cylinder 20 or accumulate the hydraulic oil. Supply to the raising chamber 21 of the self-weight compensation cylinder 20. In this embodiment, the accumulator 30 is composed of an accumulator 30. More specifically, when the load applied to the self-compensation cylinder 20 by the work machine 2 increases, the pressure of the raising chamber 21 of the self-compensation cylinder 20 increases. The operating oil in which the pressure is raised in this way is supplied to the accumulator 30 and accumulated. On the other hand, when the load of the work machine 2 is small or the work cylinder 10 is extended to receive a force in the direction in which the work machine 2 rises, the work weight compensation cylinder 20 by the work machine 2 The load on) decreases. Then, the pressure of the rising chamber 21 of the self-compensating cylinder 20 is lowered, and the hydraulic oil accumulated in the accumulator 30 is supplied to the rising chamber 21 of the self-compensating cylinder 20, whereby the self-weight The rod 22 of the compensation cylinder 20 extends in the direction in which the work machine 2 ascends.

As described above, the accumulator 30 stores the energy by accumulating the pressure of the hydraulic oil in accordance with the pressure applied from the working machine 2 to the self-compensating cylinder 20, or stores the stored hydraulic oil in the self-compensating cylinder ( 20, the flow rate and pressure of the hydraulic oil to be supplied to the working cylinder 10 to raise the work machine 2 is decelerated, whereby the flow rate and pressure of the hydraulic oil discharged from the pump 1 Will decrease. Therefore, the construction machinery can save energy, which can significantly improve fuel economy.

On the other hand, by the accumulator 30 and the self-weight compensation cylinder 20, the work machine 2 is maintained in a state receiving a force in the rising direction. That is, the high pressure is formed in the ascending chamber 11 of the working cylinder 10 by the load of the work machine 2 as well as the accumulator 30 and the descending chamber 12 of the working cylinder 10. The high pressure may be formed by a force applied to the work weight 2 by the self-weight compensation cylinder 20. Therefore, holding valve units 50 and 60 for preventing leakage through the work machine control valve 40 are required in both the rising chamber 11 and the lower chamber 12 of the working cylinder 10. Hereinafter, the holding valve units 50 and 60 will be described.

The first holding valve unit 50 is for preventing the hydraulic oil of the lifting chamber 11 of the working cylinder 10 from leaking through the work machine control valve 40, and raising the working cylinder 10. It is installed in the rising supply line 13 connected to the chamber 11. The first holding valve unit 50 includes a first logic valve 51 and a first control valve 52 for controlling the first logic valve 51. The first control valve 52 has a first hydraulic pressure portion 52a to which the rising signal pressure Pb1 of the work machine is applied. The first logic valve 51 and the first control valve 52 maintain the state as shown in FIG. 3 when the rising signal pressure Pb1 is not applied to the first hydraulic pressure unit 52a. It is to prevent the operating oil of the rising chamber 11 of the back flow to the work machine control valve (40). On the other hand, when the rising signal pressure Pb1 is applied to the first hydraulic pressure unit 52a, the first control valve 52 is converted to the right side of FIG. 3, whereby the first head of the first logic valve 51. The hydraulic oil of the chamber 51a is drained. Therefore, the hydraulic oil supplied to the first head chamber 51a can push the first poppet 51c and be supplied to the raising chamber 11 of the working cylinder 10.

The second holding valve unit 60 is for preventing the hydraulic oil of the lowering chamber 12 of the working cylinder 10 from leaking through the working machine control valve 40, and the lowering chamber of the working cylinder 10 ( 12 is the same as the first holding valve unit 50, except that it is installed in the lower supply line 14 for supplying the operating oil. That is, the second holding valve unit 60 includes a second logic valve 61 and a second control valve 62 for controlling the second logic valve 61. The second control valve 62 has a second hydraulic pressure portion 62a to which the falling signal pressure Pb2 of the work machine is applied. The second logic valve 61 and the second control valve 62 maintains the state as shown in FIG. 3 when the falling signal pressure Pb2 is not applied to the second hydraulic pressure unit 62a. The backflow to the work machine control valve 40 of the lowering chamber 12 is prevented. On the other hand, when the falling signal pressure Pb2 is applied to the second hydraulic pressure unit 62a, the second control valve 62 is converted to the right side of FIG. 3, whereby the second head of the second logic valve 61. The hydraulic oil of the chamber 61a is drained. Therefore, the hydraulic oil supplied to the second head chamber 61a can push the second poppet 61c and be supplied to the lowering chamber 12 of the working cylinder 10.

In order to compare the energy saving efficiency of the work machine driving device having the configuration as described above with the conventional excavator, the device was driven by the trajectory as shown in FIG. 4, and the energy saving efficiency was improved by 60 to 70% as shown in FIGS. .

More specifically, FIGS. 5A and 5B show the energy consumed when the conventional excavator and the excavator to which the present embodiment is applied are driven along the trajectory as shown in FIG. 4. It can be seen from FIG. 5A that the existing excavator consumes 0.37 kwh when the work is completed. From FIG. 5B, the excavator applied to the present embodiment shows that 0.12 kwh is consumed when the work is completed. That is, according to one embodiment of the present invention, it can be seen that the energy efficiency of about 67% is improved.

Figure 6a shows the power consumed to move the existing excavator along the trajectory as shown in Figure 4, Figure 6b shows the power consumed when the excavator applied to the work machine drive device according to the present embodiment moves along the trajectory as shown in Figure 4 It is shown. As can be seen from the graph, it can be seen that the power of the excavator to which the present embodiment is applied is much reduced.

7 is a schematic view of an excavator to which a work implement driving device according to another embodiment of the present invention is applied.

Another embodiment of the present invention is the same as the embodiment except that the accumulator 130 is composed of a counter weight 131 and the accumulator cylinder 132. Therefore, hereinafter, only the accumulator 130 will be described in detail.

The counter weight 131 is installed on the main body 6 of the construction machine so as to be movable in the vertical direction. More specifically, the counter weight 131 is installed in the main body 6 so as to be movable in the vertical direction by guide parts such as guide rails and guide grooves.

The accumulator cylinder 132 is installed below the counter weight 131 to move the counter weight 131 in the up and down direction according to the pressure formed in the ascending chamber 133 of the accumulator cylinder 132. . The rising chamber 133 of the pressure storage cylinder 132 is connected in communication with the rising chamber 21 of the self-weight compensation cylinder 20, as in the embodiment.

As a result, when the high pressure is formed in the raising chamber 21 of the self-compensating cylinder 20 by the work machine 2, the hydraulic oil of the raising chamber 21 of the self-compensating cylinder 20 is It is supplied to the rising chamber 133 of the cylinder 132. Then, the counter weight 131 moves upward while the rod 134 of the accumulator cylinder 132 extends.

On the other hand, when low pressure is formed in the rising chamber 21 of the self-compensating cylinder 20, the hydraulic fluid of the rising chamber 133 of the accumulating cylinder 132 is the rising chamber (of the self-compensating cylinder 20). 21), whereby the self-compensation cylinder 20 provides the power for raising the work machine (2).

As such, according to another embodiment of the present invention, the energy accumulated by the self-weight of the work machine 2 by the accumulator 130 and the self-weight compensation cylinder 20 is used as a power for raising the work machine 2. By providing it, it is possible to reduce the energy to be supplied to the working cylinder 10 in order to raise the work machine 2, whereby it is possible to significantly improve the fuel economy of the construction machine.

1 is a conceptual diagram of a work machine driving device of a construction machine according to an embodiment of the present invention,

FIG. 2 is a side view schematically showing a construction machine to which a work device driving device of FIG. 1 is applied; FIG.

3 is a circuit diagram schematically showing the work machine driving device of FIG.

4 is a view schematically showing the trajectory of the work machine for experimenting with the energy saving efficiency of the work machine driving device of FIG.

5A and 5B are graphs schematically showing energy required to drive a work machine along the trajectory shown in FIG. 4, and compare a conventional construction machine with a construction machine to which an embodiment of the present invention is applied.

6A and 6B are graphs schematically showing the power required to drive a work machine along the trajectory shown in FIG. 4, and compare the existing construction machine with the construction machine to which an embodiment of the present invention is applied.

7 is a side view schematically showing a construction machine to which a work implement driving device according to another embodiment of the present invention is applied.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS

2; Work machine, boom 10; Working cylinder

20; Self-compensating cylinders 30 and 130; Accumulator, accumulator

50, 60; First and second holding valve units 131; Counter weight

132; Accumulator

Claims (5)

The lower chamber 12 receives the hydraulic oil discharged from the pump 1 through the rising supply line 13 and the lower chamber 12 receives the hydraulic oil discharged from the pump 1 through the lower supply line 14. A working cylinder (10) for elevating and driving the work machine (2) according to the supply direction of the hydraulic oil; A self-compensation cylinder 20 having a raising chamber 21 to which hydraulic oil is supplied in a rising direction of the working machine 2 to assist the raising of the working machine 2; And It is connected in communication with the rising chamber 21 of the self-compensation cylinder 20, the lifting chamber of the self-compensation cylinder 20 according to the load applied to the self-compensation cylinder 20 by the work machine 2 And a accumulator part (30) (130) for supplying the accumulator or the accumulated hydraulic fluid to the lifting chamber (21) of the self-weight compensation cylinder (20). The method of claim 1, The accumulator 30 is an accumulator 30, the work machine driving device of the construction machine. The method of claim 1, wherein the accumulator 130, A counter weight 131 installed on the main body 6 so as to be movable up and down; And And a rising chamber 133 connected in communication with the rising chamber 21 of the self-weight compensation cylinder 20, and capable of driving the counter weight 131 up and down in accordance with the pressure of the rising chamber 133. Working device driving device for a construction machine, characterized in that it comprises a accumulator cylinder (132) installed on the counter weight (131). The method of claim 1, A first holding valve unit (50) for preventing leakage of hydraulic oil in the raising chamber (11) of the working cylinder (10); And And a second holding valve unit (60) for preventing leakage of hydraulic oil in the lowering chamber (12) of the working cylinder (10). The method of claim 1, The work machine 2 is a work machine driving device of the construction machine, characterized in that the arm (3) and the bucket (4) is mounted on the front end to support the load of the arm (3) and bucket (4). .

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