KR101625681B1

KR101625681B1 - Sudden Turning Prevention System for Construction Machinery

Info

Publication number: KR101625681B1
Application number: KR1020090129767A
Authority: KR
Inventors: 황거선
Original assignee: 두산인프라코어 주식회사
Priority date: 2009-12-23
Filing date: 2009-12-23
Publication date: 2016-05-30
Also published as: KR20110072719A; CN102108720A; CN102108720B

Abstract

A hydraulic system for preventing a sudden turn of a construction machine is disclosed. The disclosed invention is directed to a control system for controlling a main pump, a first pump and a second pump, a swing control valve, a running straight valve connecting a first pump to a main pump or a drain line of a swing control valve, A plurality of front control valves connected to the tank, a traveling control valve connected to the main pump for controlling the traveling motor or connecting the second pump to the tank, and a hydraulic line and a swing control valve for connecting the first pump and the traveling straight- And a swinging speed reducing line that connects the swing hydraulic line to the tank and a hitching speed reducing line that is opened by a signal for driving the swing motor in a state where the front working machine and the traveling motor are operated, And a quick turn reduction valve that connects the line to the tank to prevent a swirling of the swing motor.

Pump, Swing control valve, Front control valve, Reduction valve, Hydraulic line

Description

[0001] Sudden Turning Prevention System for Construction Machinery [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic system for preventing rushing of a construction machine, and more particularly, to a hydraulic system for preventing rushing of a construction machine, which can prevent a turning impact generated by a rush- .

Among the construction machines, the excavator is driven by a traveling motor, which is a hydraulic motor, and the upper swing body is swung by a swing motor which is a hydraulic motor. Booms, arms, buckets and the like corresponding to the front working machine are driven by hydraulic cylinders.

Since the drive unit such as the hydraulic motor and the hydraulic cylinder is driven by the hydraulic oil, the hydraulic oil discharged from the pump to each of the drive units must be appropriately distributed. If the flow rate of the hydraulic fluid supplied to any one of the left and right traveling motors is insufficient when the traveling, the front working machine, or the turning operation is simultaneously performed, the traveling can not be performed straight.

1A, the traveling straight ahead valve 30 connects the first pump 10 to the drain line 40 in an initial state to drain hydraulic oil discharged from the first pump 10, 10 from the first and second merging lines 41, 42. On the other hand, the operating fluid of the first pump 10 is waiting at the front end of the swing control valve 50 through the swing parallel line 43 connected to the swing control valve 50, bypassing the traveling straight ahead valve 30.

In this state, when the travel signal and the arm operation signal are generated, the first travel control valve 60 and the arm first-speed control valve 70 are converted into the state shown in FIG. 1B. The first drive control valve 60 and the arm first speed control valve 70 thus cut off the first and second branch signal lines 32 and 33 connected to the second pump 20. Then, a high pressure is formed in the traveling straight-ahead signal line 31 connecting the water-pressure portion 30a of the traveling straight-ahead valve 30 and the second pump 20, and the traveling straight- .

1B, the first pump 10 is connected to the first and second merging lines 41 and 42 through the straight running valve 30. As a result, the hydraulic fluid discharged from the first pump 10 is supplied to the boom first-speed control valve 90 through the first merging line 41 and is supplied through the second merging line 42 to the first- And supplies the operating fluid to the valve 70. On the other hand, the first running control valve 60 is supplied with the hydraulic oil by the main pump P1.

The first and second merging lines 41 and 42 are communicated with the swing parallel line 43 through the traveling straight-ahead valve 30. The operating fluid flowing through the first and second merging lines 41 and 42 is supplied to the boom first speed control valve 90 and the arm first speed control valve 70 at the front end thereof, . At this time, the operating pressure of the boom and the arm is about 100 bar. Accordingly, a pressure of about 100 bar is formed in the first and second merging lines 41 and 42. The drain line 40 of the first pump 10 is shut off by the running straight valve 30 and the turning parallel line 43 is connected to the first and second merging lines 41 and 42, And the parallel line 43 is also formed to the extent of 100 bar.

On the other hand, the operating pressure of the swing motor is about 50 bar. The swing motor is driven by converting the swing control valve 50 in the state shown in Fig. 1B and connecting the swing parallel line 43 to the swing motor 51 side. At this time, the high-pressure, high-flow hydraulic oil of about 100 bar is supplied to the swing motor 51 through the swing control valve 50. In this state, the swing motor 51 is suddenly driven, and a swinging shock occurs in which the upper swing body swings at a suddenly high speed. In the case of a turning impact, there is a high possibility that a safety accident occurs because the upper revolving body turns suddenly and swiftly unlike the driver's intention.

Further, when the running, the front work and the swing drive are simultaneously performed, the operating pressure of the boom and the arm is relatively large, so that most of the operating oil discharged from the first pump 10 is supplied to the swing motor 51. Therefore, the operating fluid supplied to the boom cylinder and the arm cylinder through the first and second merging lines 41 and 42 is minimized. As a result, the driving speed of the front working machine is remarkably lowered and the efficiency of the work is lowered.

Particularly, not only the boom but also the load of the arm and the bucket are applied to the boom cylinder, so that a high pressure is formed in the rising chamber of the boom cylinder. Therefore, in the case where only the second running control valve (not shown) is only half-converted, a part of the operating oil of the main pump P1 is supplied to the running motor through the running control valve (not shown) Speed control valve 90 to the boom cylinder.

Here, the working oil of the main pump is joined to the first joining line 41 at the front end of the boom first-speed control valve 90, and the operating pressure of the swing motor 51 is only about 50 bar at the first joining line 41 . At this time, when the pressure of the hydraulic oil is 100 bar or more, the hydraulic fluid supplied to the boom cylinder flows back to the swivel parallel line 43 through the first joining line 41 and the traveling straight-ahead valve 30.

Therefore, a greater flow rate of hydraulic fluid is supplied to the swing motor 51, which not only increases the turning impact but also significantly lowers the driving speed of the boom cylinder.

On the other hand, the pressure receiving portion 30a of the traveling straight ahead valve 30 is communicated with the second pump 20 so that when the traveling control valve 60 and the front control valve 70 are simultaneously converted, Is suddenly converted into a state as shown in Fig. 1B in the state shown in Fig. 1A. That is, the traveling straight ahead valve 30 is converted to the ON / OFF system.

In this way, the drain line 40 is suddenly blocked because the traveling straight ahead valve is switched to the on / off system, and suddenly a large pressure is suddenly formed in the swing parallel line 43. These factors also amplify the turning impact even more.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art described above, and it is an object of the present invention to provide a hydraulic system for preventing rushing of a construction machine, which can prevent a turning impact, .

The hydraulic system for preventing rushing of a construction machine according to the present invention comprises a main pump for driving a traveling motor and a front working machine; A first pump for driving the swing motor; A second pump for providing a pilot signal pressure; A swing control valve to which the hydraulic pump is connected to the first pump and which controls the swing motor by a plurality of positions; And a connecting position for connecting a hydraulic line connected to the first pump to both connecting points connected to the main pump and a connecting line connecting the hydraulic line connected to the first pump to the drain line of the swing control valve, Straightening valve; A plurality of front control valves connected to a hydraulic line at any one of connection points on either side of the traveling straight ahead valve and providing a plurality of selectable positions for controlling the front working machine or connecting the second pump to the tank; A travel control valve connected to the main pump to control the travel motor and to provide a plurality of selectable positions for controlling the travel motor or connecting the second pump to the tank; And a swing hydraulic line connecting the swing control valve to a hydraulic line side connecting the first pump and the traveling straight-ahead valve, the hydraulic system comprising: a swing deceleration decelerator for connecting the swing hydraulic line to the tank; And a hull emergency deceleration valve installed at the hull emergency deceleration line and connected to the tank by being opened by a signal for driving the swing motor in a state where the front working machine or the traveling motor is operated.

Here, the throttle deceleration valve is opened by a pilot signal associated with the swing control valve in a check valve manner in which the flow rate is controlled.

The throttle deceleration line may be connected to the swing control valve and connected to the tank through the swing control valve.

In the hydraulic system for preventing the sudden turn of the construction machine according to the present invention, the main pump connected to the merging position of the traveling straight ahead valve during traveling and front operation can be applied to improve the working speed.

When the vehicle is running + the front + the wheel is combined, the hurry deceleration valve is opened by the swing pilot signal, and the hydraulic oil input to the swing control valve is supplied to the swing motor. And the hydraulic oil receiving the pressure on the running side and the front side is partially drained through the throttle deceleration valve to improve the turning jumping to the side of the turning motor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a hydraulic system for preventing a breakwater of a construction machine according to the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator.

FIG. 2 is a circuit diagram showing a single swing operation of a hydraulic system for preventing a sudden turn of a construction machine according to an embodiment of the present invention. FIG. 3 is a schematic view of a hydraulic system for preventing rushing of a construction machine according to an embodiment of the present invention, 4 is a circuit diagram showing a traveling + front + swing operation of a hydraulic system for preventing a sudden turn of a construction machine according to an embodiment of the present invention.

Referring to FIG. 2, the hydraulic system for preventing rushing of a construction machine according to an embodiment of the present invention includes main pumps 100 and 101, a first pump 105, a second pump 110, a swing control valve 115, A plurality of hydraulic lines connecting respective components of the hydraulic control system 100 are connected to each of the hydraulic control valves 130, 132, the forward traveling valve 125, the front control valves 130, 131, the travel control valve 135, the pivot hydraulic line 116, .

Here, the main pumps 100 and 101 are composed of a plurality of pumps, and supply operating fluid to the traveling motor 136 and the front working machine (boom, arm, bucket). The first pump 105 performs a function of supplying operating oil to the front working machine and the swing motor 133. The second pump 110 is connected to a pilot switch for switching positions of the swing control valve 115, the forward straightening valve 125, the front control valve 130, the travel control valve 135 and the like via a joystick control valve Signal (the pilot lines are all connected to the tank on the circuit).

The swivel control valve 115 is connected to the first pump 105 via a hydraulic line, and controls the swivel motor 133 by a plurality of positions. The travel straight ahead valve 125 has a merging position 126 for connecting the hydraulic line 106 connected to the first pump 105 to the both connecting points 107 and 108 and a hydraulic line 106 connected to the first pump 105 ) To the drain line (109) of the swing control valve (115). The front control valves 130 and 131 are connected to the connection point 108 of one of the connection points on both sides of the straight running valve 125. The front control valves 130 and 131 control the front work machine or connect the second pump 110 to the tank 150, As shown in FIG.

The travel control valve 135 is connected to the main pump 101 to control the travel motor 138 and to control the travel motor 138 or to connect the second pump 110 to the tank 150, Location. The swirling hydraulic line 116 connects the swing control valve 115 to the hydraulic line 106 side connecting the first pump 105 and the traveling straight-ahead valve 125.

Here, the plurality of positions of the swing control valve 115, the front control valve 130, and the travel control valve 135 include a forward position 121 for providing the hydraulic fluid in the forward direction, a reverse position 122, a shutoff position 123 for disconnecting the supply of hydraulic fluid, an internal drain line position 124 for connection to the tank, and the like. Each control valve is a conventionally used technology, and is equipped with a spool that is switched in position in accordance with the characteristics of a driving part supplied with operating fluid, and is controlled by a pilot signal so as to distribute a proper operating fluid according to the operating order and operating load of each driving part.

On the other hand, the hull reducing speed reducing valve 145 according to the present embodiment is regarded as opened when the swing operation signal is inputted. The hull reduction deceleration valve 145 has a function of connecting the swirl hydraulic line 116 to the tank 151 by being opened by a signal swing pi which is provided to the hull reduction deceleration line 148 and drives the linear motor 133 . Here, the throttle deceleration valve 145 is opened by a pilot signal associated with the swing control valve 115 in a check valve manner. The orifice disposed inside the check valve upstream of the throttle deceleration valve 145 is for ensuring the pressure of the working fluid waiting for the swing motor drive. The hull deceleration line 148 is also connected to the swirl control valve 115 and to the tank 151 via the swirl control valve 115.

Hereinafter, an operating state of a hydraulic system for preventing a breakaway of a construction machine according to an embodiment of the present invention will be described. 2, the swivel signal causes the swivel control valve 115 to move to the right and the X-shaped directional line in the reverse position 122 to the swivel hydraulic line 116 and the swivel drain line Lt; / RTI >

The operating fluid of the first pump 105 flows into the swing motor 133 via the swing hydraulic line 116 and the swing control valve 115 and is driven through the swing drain line 117 after driving the swing motor 133 And then flows into the tank 151. At this time, a part of the hydraulic oil discharged from the first pump 105 passes through the inner drain 109 of the traveling straight-ahead valve 125 and is in a waiting state in the inner drain line of the swing control valve 115. The operating fluid of the second pump 110 flows into the tank 150 through the inner drains 118a, 118b and 118c of the front control valve 130 and the travel control valve 135, ) Does not provide working pressure.

The hydraulic circuit is connected to the swing hydraulic line 116 by a pilot signal causing a swing operation and the hydraulic fluid passes through the swirl reducing speed reducing valve 145 or the swirl reducing speed reducing valve 145 The operating pressure of the swirling hydraulic line 116 by the swirling speed reducing valve 145 is not decreased since the inner drain line 119a of the swing control valve 115 connected to the swirling speed reducing valve 145 is shut off.

The front control valves 130 and 131 and the travel control valve 135 are disconnected from the hydraulic line for supplying the hydraulic oil to the front actuator and the traveling motor 138. When the inner drain lines 119b and 119c are connected to each other And the operating fluid of the main pump 101 is sent to the tank 151 as it is. Therefore, the swing single operation by the first pump 105 is smoothly performed normally.

See FIG. 3 for travel + front drive. When the pilot signal is applied to the front control valve 130 driving the arm, the front control valve 130 is moved to the left. Then, the pilot signal is applied to the travel control valve 135, and the travel control valve 135 is moved to the right. At this time, the front drainage lines 118b and 118c of the front control valve 130 and the travel control valve 135 for draining the hydraulic fluid of the second pump 110 are shut off, and the second pump 110 is closed 125, and the travel straight-ahead valve 125 is moved to the right.

The joining position 126 of the forward straight ahead valve 125 joins the operating fluid of the first pump 105 and the main pump 100 and a part of the operating fluid of the first pump 105 drives the arm cylinder 132 To the front control valve 130. The front control valve 130 moves to the left and is switched to the forward position 121a and the operating oil is supplied to the arm cylinder 132 driving the arm via the front operating line 134. [ The travel control valve 135 is in the reverse position 122a such as the X shape and is supplied with the operating fluid of the main pump 100 to the traveling motor 138. [

That is, the front control valve 130 and the straight traveling valve 125 are switched to the positions for driving the front and traveling motors. The traveling straight ahead valve 125 is switched to the right side and the first pump 105 is in a state of supplying the hydraulic fluid to the front and swing control valve 115. The front and the traveling motor are normally operated and the swing control valve 115 is in a state in which there is no pilot signal for driving the swing motor 133 and the first pump 105 and the swing motor 133 are disconnected State. Therefore, the traveling motor and the front are normally operated by the operating fluid of the first pump 105 and the main pump 100 without the swing pilot signal.

Fig. 4 shows a state immediately before the swing control valve 115 is switched when the running + front + swing drive is performed in combination. This combined operation is performed by applying the swing pilot signal to the swing control valve 115 in the state of Fig. That is, the operating state is changed from FIG. 3 to FIG. The swivel hydraulic line 116 is connected to the confluence position 126 of the drive straight valve 125 to which the main pump 100 is connected before the swivel control valve 115 is switched to drive the swivel motor 133 . At this time, the swivel hydraulic line 116 is under a pressure of about 100 bar by the front working machine connected to the merging position 126 and the traveling motor 138, and is at a higher pressure than the normal swivel operating pressure of 50 bar.

At this time, the pilot signal is applied to the side of the hurry reduction deceleration valve 145 by the swing pilot signal, and the hurry reduction deceleration valve 145 is opened. The throttle deceleration valve 145 is connected to the drain line 119a of the swing control valve 115 by the rapid deceleration line 148 and the inner drain line 119a of the swing control valve 115 is connected to the tank 151, The operating oil of the swirling hydraulic line 116 connected to the first pump 105 is drained to the tank 151 through the quick turn reducing valve 145 at a certain flow rate. In order for the throttle deceleration valve 145 to open before the swing control valve 115, the opening of the throttle deceleration valve 145 should be set to operate at a hydraulic pressure lower than the pilot hydraulic pressure for switching the swing control valve 115.

Thereafter, the swing control valve 115 is shifted to the left or right according to the swing pilot signal to switch to the forward position 121 or the reverse position 122, and the swing hydraulic line 116 to the swing motor 133 . Accordingly, when the swing pilot signal is applied, the hurry reduction deceleration valve 145 is opened so that the operating pressure of the swirling hydraulic line 116 can be reduced to about 50 bar, which is the normal operating pressure, and the swing motor 133 is normally operated do. At this time, the flow rate of the drain flowing into the tank 151 through the orbiting hydraulic line 116 can be adjusted by using the orifice of the throttle deceleration valve 145.

Meanwhile, as described above, the hydraulic circuit shown in one embodiment of the present invention shows a hydraulic circuit constructed in an excavator among construction machines. The front control valve includes both the boom control valves 1 and 2, the arm control valves 1 and 2, and the bucket control valve, only the boom control valve 2 and the arm control valve 1 are shown. The boom 2 cylinder is connected to another front control valve 131 corresponding to the boom control valve 2 although not shown. The boom control valve 1 and the arm control valve 2, which are not shown, can be configured in a lower region of the drawing where the main pump 100 is connected. That is, in the region where the main pump 100 is connected, a traveling control valve and a traveling motor driven by the main pump 100 and constituting another axis of the traveling, a boom 1 control valve and a boom 1 cylinder, a bucket control valve and a bucket cylinder May be constructed.

Figs. 1A and 1B are schematic views of a conventional construction machine hydraulic circuit.

FIG. 2 is a circuit diagram showing a single turning operation of a hydraulic system for preventing a rush current of a construction machine according to an embodiment of the present invention.

3 is a circuit diagram showing a traveling + front operation of a hydraulic system for preventing a sudden turn of a construction machine according to an embodiment of the present invention.

4 is a circuit diagram showing a traveling + front + swing operation of a hydraulic system for preventing a sudden turn of a construction machine according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

100, 101: main pump 105: first pump

110: Second pump 115: Swing control valve

116: Swirl hydraulic line 117: Swirl drain line

121: Forward position 122: Reverse position

123: shutoff position 125: traveling straight-ahead valve

126: Joining position 127: Joining position

130, 131: front control valve 135: travel control valve

145: Rapid deceleration valve 148: Rapid deceleration line

Claims

Main pumps (100, 101) for driving a traveling motor and a front working machine; A first pump 105 for driving the swing motor; A second pump (110) providing a pilot signal pressure; A swing control valve 115 connected to a hydraulic line of the first pump 105 and controlling the swing motor by a plurality of positions; A merging position 126 for connecting the hydraulic line connected to the first pump 105 to both connection points connected to the main pump and a hydraulic line connected to the first pump 105 are connected to the swing control valve 115, A forward straightening valve 125 including a connecting position 127 for connecting to the drain line of the valve; And a pivot hydraulic line 116 connecting the pivot control valve 115 to a hydraulic line side connecting the first pump 105 and the traveling straight ahead valve 125. In the hydraulic system of the construction machine, ,

A hurry deceleration line 148 connecting the swirling hydraulic line 116 to the tank and a signal provided to the hurry deceleration line 148 to open the swirling hydraulic line 116, A hydraulic system for preventing rushing of a construction machine including a quick turn reduction valve (145) connected to a tank.

The method according to claim 1,

Wherein the quick turn reducing valve (145) is opened by a pilot signal associated with the turn control valve (115) in a check valve manner in which the flow rate is controlled.

The method according to claim 1,

Wherein the hull reduction deceleration line (148) is connected to the swirl control valve (115) and connected to the tank through the swirl control valve (115).