KR20110072719A - Sudden turning prevention system for construction machinery - Google Patents

Abstract

PURPOSE: A sudden turning prevention hydraulic system for a construction machine is provided to prevent the reduction of working speed by employing a circular circuit in which a main pump is connected to the junction of a straight driving valve in driving and front operation. CONSTITUTION: A sudden turning prevention hydraulic system for a construction machine comprises main pumps(100,101), a first pump(105), a second pump(110), a turning control valve(115), a straight driving valve(125), and a turning hydraulic line(116). The main pumps drive a driving motor and a front working machine. The first pump drives a turning motor. The second pump provides pilot signal pressure. The turning control valve comprises a hydraulic line connected to the first pump and controls the turning motor through a plurality of positions. The straight driving valve comprises a junction position(126) and a connection location(127). The turning hydraulic line connects the running control valve to a hydraulic line connecting the first pump and the straight driving valve.

Description

Sudden Turning Prevention System for Construction Machinery

The present invention relates to a hydraulic system for preventing sharp turning of construction machinery, and more particularly, a hydraulic system for preventing sharp turning of construction machinery that can prevent turning impact caused by sharp turning when simultaneously performing front work and traveling and turning combined motion. It is about.

The excavator of the construction machine is driven by a traveling motor, which is a hydraulic motor, and the upper pivot is pivoted by a turning motor, which is a hydraulic motor. The booms, arms and buckets that correspond to the front work are driven by hydraulic cylinders.

Drives such as hydraulic motors and hydraulic cylinders are driven by hydraulic oil, so the hydraulic fluid discharged from the pump must be properly distributed to each driving side. When driving and the front work machine or turning at the same time, if the flow rate of the hydraulic oil supplied to either of the left and right traveling motor is insufficient, it will not be able to drive straight.

Referring to FIG. 1A, the driving straight valve 30 connects the first pump 10 to the drain line 40 in an initial state to drain the hydraulic oil discharged from the first pump 10, and the first pump ( 10) is blocked from the first and second confluence lines (41, 42). On the other hand, the hydraulic oil of the first pump 10 is waiting for 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 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 to the state as shown in FIG. 1B. The first traveling control valve 60 and the arm first speed control valve 70 converted as described above block the first and second branch signal lines 32 and 33 connected to the second pump 20. Then, high pressure is formed in the traveling straight signal line 31 connecting the hydraulic pressure unit 30a of the traveling straight valve 30 and the second pump 20, and the traveling straight valve 30 is in a state as shown in FIG. 1B. Is converted.

Thereafter, when the traveling straight valve 30 is converted to the state as shown in FIG. 1B, the first pump 10 is connected to the first and second confluence lines 41 and 42 through the traveling straight valve 30. As a result, the hydraulic oil discharged from the first pump 10 supplies the hydraulic oil to the boom first speed control valve 90 through the first confluence line 41, and controls the arm first speed through the second confluence line 42. The operating oil is supplied to the valve 70. On the other hand, the operating oil is supplied to the first travel control valve 60 by the main pump (P1).

On the other hand, the first and second confluence lines 41 and 42 are in communication with the turning parallel line 43 through the traveling straight valve 30. The hydraulic fluid flowing through the first and second confluence lines 41 and 42 is the hydraulic fluid of the main pumps P1 and P2 at the front end of the boom 1 speed control valve 90 and the arm 1 speed control valve 70. Joined with. At this time, the working pressure of the boom and the arm is about 100 bar. Therefore, a pressure of about 100 bar is formed in the first and second confluence lines 41 and 42. The drain line 40 of the first pump 10 is blocked by the traveling straight valve 30, and the turning parallel line 43 is connected to the first and second confluence lines 41 and 42, thereby turning. The parallel line 43 is also formed about 100bar.

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 as shown in FIG. 1B to connect the swing parallel line 43 to the swing motor 51 side. At this time, the hydraulic oil having a high pressure high flow rate of about 100 bar is supplied to the swing motor 51 through the swing control valve 50. In this state, the turning motor 51 is suddenly driven, and a turning shock occurs in which the upper swinging body turns suddenly at a high speed. If a turning shock occurs, the accident is likely to occur because the upper turning body turns suddenly and quickly, contrary to the driver's intention.

In addition, when traveling, front work and swing driving are performed at the same time, the working pressure of the boom and the arm is relatively large, so that most of the hydraulic oil discharged from the first pump 10 is supplied to the swing motor 51. Therefore, the hydraulic oil supplied to the boom cylinder and the arm cylinder through the first and second confluence lines 41 and 42 is only very small. As a result, the driving speed of the front work machine is significantly lowered, thereby reducing the efficiency of the work.

In particular, the boom cylinder is subjected to not only the boom but also the load of the arm and the bucket, so that a high pressure is formed in the raising chamber of the boom cylinder. Therefore, when only about half of the second traveling control valve (not shown) is converted, a part of the hydraulic oil of the main pump P1 is supplied to the traveling motor through the traveling control valve (not shown), and the remaining hydraulic oil of the main pump is boomed. It is supplied to the boom cylinder through the first speed control valve 90.

Here, the hydraulic oil of the main pump is joined with the first confluence 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 in the first confluence line 41. It is. At this time, when the pressure of the hydraulic oil is 100 bar or more, the hydraulic oil supplied to the boom cylinder flows back to the turning parallel line 43 through the first confluence line 41 and the traveling straight valve 30.

Therefore, the turning motor 51 is supplied with the hydraulic fluid of a larger flow rate, so that the turning impact is increased and the driving speed of the boom cylinder is significantly lowered.

On the other hand, the hydraulic pressure portion 30a of the traveling straight valve 30 communicates with the second pump 20, so that when the traveling control valve 60 and the front control valve 70 are simultaneously converted, the traveling straight valve 30 ) Is abruptly converted from the state shown in FIG. 1A to the state shown in FIG. 1B. That is, the traveling straight valve 30 is converted to the on / off method.

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

The present invention has been made to solve the above problems of the prior art, it is possible not only to prevent the turning impact, but also to prevent the sharpening of the hydraulic system of the construction machine that can prevent the driving speed of the front work machine is reduced during the composite work To provide.

Hydraulic system for preventing sharpening of the construction machine according to the present invention includes a main pump for driving the driving motor and the front work machine; A first pump for driving the swing motor; A second pump providing a pilot signal pressure; A hydraulic control line connected to the first pump, the swing control valve controlling the swing motor by a plurality of positions; A traveling position including a joining position connecting the hydraulic line connected to the first pump to both connection points connected to the main pump and a connecting position connecting the hydraulic line connected to the first pump to the drain line of the swing control valve; Straight valve; A plurality of front control valves having a hydraulic line connected to any one of two connection points of the traveling straight valve and providing a plurality of selectable positions for controlling the front work machine or connecting the second pump to a tank; A traveling control valve connected to the main pump to control a traveling motor and providing a plurality of selectable positions for controlling the traveling motor or connecting the second pump to a tank; And, in the hydraulic system of the construction machine comprising a hydraulic pressure line for connecting the pivoting control valve on the hydraulic line side connecting the first pump and the traveling straight valve, the rapid speed reduction for connecting the pivoting hydraulic line to the tank And a rapid deceleration valve installed in the rapid deceleration line and connected to the tank by the swing hydraulic line by being opened by a signal for driving the swing motor in a state where the front work machine or the traveling motor is operated.

Here, the rapid 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 rapid deceleration line may be connected to the swing control valve and connected to the tank through the swing control valve.

Hydraulic system for preventing rapid turning of construction machinery according to the present invention as described above can improve the problem that the working speed is reduced by applying the original circuit connected to the joining position of the driving straight valve when the main pump is running and front operation.

When the driving + front + turning combination, the turning deceleration valve is opened by the turning pilot signal, and the hydraulic oil inputted to the turning control valve is supplied to the turning motor so that the turning deceleration valve side is turned on in the driving + front + turning signal input state. An internal drain line of the swing control valve is connected to the hydraulic valve, and the hydraulic oil under pressure on the driving and front sides is partially drained through the sudden reduction valve to improve the swing jump on the swing motor side.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the hydraulic system for preventing sharpening of the construction machine according to the present invention. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description. 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.

Figure 2 is a circuit diagram showing a single swing operation of the hydraulic system for preventing sharp turning of the construction machine according to an embodiment of the present invention, Figure 3 is a running + front of the hydraulic system for preventing sharp turning of the construction machine according to an embodiment of the present invention 4 is a circuit diagram showing the operation, Figure 4 is a circuit diagram showing the running + front + turning operation of the hydraulic system for preventing sharp turning of the construction machine according to an embodiment of the present invention.

2, the hydraulic system for preventing rapid turning of the construction machine according to an embodiment of the present invention, the main pump (100, 101), the first pump 105, the second pump 110, the swing control valve 115 , The traveling straight valve 125, the front control valves 130 and 131, the travel control valve 135, the turning hydraulic line 116, the turning deceleration valve 145, a plurality of hydraulic lines connecting the respective components Include.

Here, the main pumps 100 and 101 are configured in plural to supply hydraulic oil to the driving motor 136 and the front work machine (boom, arm, bucket). The first pump 105 serves to supply hydraulic oil to the front work machine and the swing motor 133. The second pump 110 switches pilot positions of the swing control valve 115, the traveling straight valve 125, the front control valve 130, and the travel control valve 135 via a joystick control valve (not shown). Provides a signal (in the circuit, all pilot lines are connected to the tank).

The swing control valve 115 is a hydraulic line connected to the first pump 105, and is a valve for controlling the swing motor 133 by a plurality of positions. The traveling straight valve 125 has a hydraulic line 106 connected to the first pump 105 and a confluence position 126 connecting both connection points 107 and 108 and a hydraulic line 106 connected to the first pump 105. ) Is connected to the drain line 109 of the swing control valve 115. The front control valves 130 and 131 are connected to a hydraulic line at one connection point 108 of both connection points of the traveling straight valve 125, and control the front work machine or the second pump 110 to the tank 150. Provides a plurality of selectable locations to connect to.

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

Here, the plurality of positions of the swing control valve 115, the front control valve 130, and the travel control valve 135 may be a forward position 121 for providing hydraulic oil in a forward direction, and a reverse position for providing in the reverse direction ( 122), a cutoff position 123 for stopping the supply of hydraulic oil, an internal drain line position 124 connected to the tank, and the like. Each control valve is a technique used in the related art, and a spool whose position is switched in accordance with a characteristic of a driving part supplied with hydraulic oil is installed, and is controlled by a pilot signal to distribute appropriate hydraulic fluid in accordance with the operation order and operating load of each driving part.

On the other hand, the turning deceleration valve 145 according to the present embodiment is considered to be opened when the turning operation signal is input. The turning deceleration valve 145 is installed in the turning deceleration line 148 and is opened by a swing pi driving the turning motor 133 to connect the turning hydraulic line 116 to the tank 151. To perform. Here, the turning deceleration valve 145 is opened by a pilot signal associated with the turning control valve 115 in a check valve manner. The orifice disposed inside the check valve upstream side of the rapid deceleration valve 145 is for ensuring the pressure of the working oil waiting for the swing motor to be driven. In addition, the turning deceleration line 148 is connected to the turning control valve 115 is connected to the tank 151 through the turning control valve 115.

Hereinafter, it looks at the operating state of the hydraulic system for preventing sharp turning of the construction machine according to an embodiment of the present invention. Referring to FIG. 2, the turning control valve 115 is moved to the right by the turning signal, and the X-shaped direction line at the reverse position 122 is the turning hydraulic line 116 and the turning drain line. 117 is connected.

The hydraulic oil of the first pump 105 flows into the swing motor 133 through the swing hydraulic line 116 and the swing control valve 115, drives the swing motor 133, and then through the swing drain line 117. Flows into the tank 151. At this time, a part of the hydraulic oil discharged from the first pump 105 passes through the internal drain 109 of the traveling straight valve 125 to be in a standby state in the internal drain line of the swing control valve 115. In addition, the operating oil of the second pump 110 flows into the tank 150 through the internal drains 118a, 118b, and 118c of the front control valve 130 and the travel control valve 135, and the travel straight valve 125. ) Is not provided with working pressure.

In addition, the rapid turning deceleration valve 145 connected to the turning hydraulic line 116 is opened by a pilot signal causing turning operation, and the operating oil passes through the turning deceleration valve 145 or the turning deceleration valve 145. Since the internal drain line 119a of the swing control valve 115 connected to) is blocked, the operating pressure of the swing hydraulic line 116 by the swing reduction valve 145 is not reduced.

In addition, the front control valves 130 and 131 and the traveling control valve 135 are disconnected from the hydraulic lines for supplying the hydraulic oil to the front actuator and the driving motor 138, and the internal drain lines 119b and 119c are connected to each other. In this state, the hydraulic oil of the main pump 101 is directly sent to the tank 151. Therefore, the turning-only operation by the first pump 105 is smoothly and normally performed.

See FIG. 3 for driving + front driving. When a pilot signal is applied to the front control valve 130 for driving the arm, the front control valve 130 is moved to the left. Then, a pilot signal is applied to the travel control valve 135 to move the travel control valve 135 to the right. At this time, the internal drain lines 118b and 118c of the front control valve 130 and the travel control valve 135 to drain the hydraulic oil of the second pump 110 are blocked, and the second pump 110 is a traveling straight valve ( Provide more working pressure, and the travel straight valve 125 is moved to the right.

The confluence position 126 of the traveling straight valve 125 joins the hydraulic oil of the first pump 105 and the main pump 100, and a part of the hydraulic oil of the first pump 105 drives the arm cylinder 132. Is supplied to the front control valve 130. As the front control valve 130 is moved to the left and switched to the forward position 121a, the hydraulic oil is supplied to the arm cylinder 132 for driving the arm via the front operation line 134. In addition, the traveling control valve 135 is a state in which the hydraulic oil of the main pump 100 is supplied to the traveling motor 138 as the reverse position 122a as the X shape.

That is, the front control valve 130 and the traveling straight valve 125 are switched to the position for driving the front and the driving motor. The traveling straight valve 125 is switched to the right side, and the first pump 105 is in a state of supplying hydraulic oil to the front and swing control valves 115. The front and driving motors are normally operated, and the turning control valve 115 has no pilot signal for driving the turning motor 133. The first pump 105 and the turning motor 133 are disconnected. It is a state. Therefore, in the absence of the turning pilot signal, the operation of the traveling motor and the front is normally performed by the hydraulic oil of the first pump 105 and the main pump 100.

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

At this time, the pilot signal is applied to the rapid deceleration valve 145 side by the turning pilot signal, and the rapid deceleration valve 145 is opened. The turning deceleration valve 145 is connected to the drain line 119a of the turning control valve 115 by the turning deceleration line 148, and the internal drain line 119a of the turning control valve 115 is connected to the tank 151. Since it is connected to the hydraulic oil of the turning hydraulic line 116 connected to the first pump 105, some flow rate is drained to the tank 151 through the turning speed reducing valve 145. In order for the rapid deceleration valve 145 to open earlier than the swing control valve 115, the rapid deceleration valve 145 opening must be set to operate at a hydraulic pressure smaller than the pilot pressure for switching the swing control valve 115.

Thereafter, the swing control valve 115 is moved left or right according to the swing pilot signal and is switched to the forward position 121 or the reverse position 122, and the swing hydraulic line 116 is connected to the swing motor 133. Connected. Therefore, when the turning pilot signal is applied, the turning deceleration valve 145 is opened so that the operating pressure of the turning hydraulic line 116 can be reduced to about 50 bar, which is a normal operating pressure, and the turning motor 133 operates normally without turning rapidly. do. At this time, the flow rate of the drain flowing into the tank 151 through the turning hydraulic line 116 may be adjusted by using the orifice of the rapid turning reduction valve 145.

On the other hand, the hydraulic circuit shown in one embodiment of the present invention as described above shows a hydraulic circuit configured in the excavator of the construction machine. The front control valve includes all of the boom control valves 1 and 2 and the arm control valves 1 and 2 and the bucket control valve, and only the boom control valve 2 and the arm control valve 1 are shown. Although not shown, the boom 2 cylinder is connected to another front control valve 131 corresponding to the boom control valve 2. The boom control valve 1 and the arm control valve 2 (not shown) may have a circuit configured in the lower region of the drawing in which the main pump 100 is connected. That is, the driving control valve and the driving motor, the boom 1 control valve and the boom 1 cylinder, the bucket control valve and the bucket cylinder, etc., which are connected to the main pump 100 and driven and constitute the other axis of the driving, are connected to the main pump 100. A hydraulic circuit including a may be configured.

1a and 1b is a view schematically showing a conventional construction machinery hydraulic circuit.

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

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

4 is a circuit diagram illustrating a driving + front + turning operation of the hydraulic system for preventing a sharp turn of a construction machine according to an embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

100, 101: main pump 105: first pump

110: second pump 115: swing control valve

116: swing hydraulic line 117: swing drain line

121: forward position 122: reverse position

123: blocking position 125: driving straight valve

126: confluence position 127: connection position

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

145: sharpening deceleration valve 148: sharpening deceleration line

Claims (3)

Main pumps 100 and 101 for driving the traveling motor and the front work machine; A first pump 105 for driving the swing motor; A second pump 110 providing a pilot signal pressure; A hydraulic control line connected to the first pump 105 and a swing control valve 115 controlling the swing motor by a plurality of positions; The turning control valve 115 connects the hydraulic line connected to the first pump 105 and the confluence position 126 connecting the hydraulic line connected to the first pump 105 to both connection points connected to the main pump. A traveling straight valve 125 including a connection position 127 for connecting to a drain line of the pump; And, in the hydraulic system of the construction machine including a swing hydraulic line 116 connecting the swing control valve 115 to the hydraulic line side connecting the first pump 105 and the traveling straight valve 125. , The turning hydraulic deceleration line 148 for connecting the turning hydraulic line 116 to the tank, and the turning deceleration line 148 to the signal for driving the turning motor in the state in which the front work machine or the traveling motor is operated. A hydraulic system for preventing a sharp turn of a construction machine including a sharpening deceleration valve (145) connecting the turning hydraulic line (116) to the tank by opening by the opening. The method of claim 1, The turning deceleration valve (145) is a hydraulic check system for preventing the turning of the construction machine, characterized in that the opening by the pilot signal associated with the swing control valve 115 in a check valve manner in which the flow rate is adjusted. The method of claim 1, The turning deceleration line (148) is connected to the swing control valve 115 is connected to the tank through the swing control valve 115, the hydraulic system for preventing a sharp turn of the construction machine.

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