KR20100044324A - Regulator for axial piston pump - Google Patents

Abstract

PURPOSE: A regulator for an axial piston pump is provided to selectively use a positive control method and a negative control method, and to reduce manufacturing costs by using one regulator. CONSTITUTION: A regulator for an axial piston pump comprises a main case, pilot valves(200), stroking pistons(320), first spools(370). The main case forms the exterior of the regulator. The pilot valve has a pilot case, a pilot piston, and a lever(310). The pilot case is selectively coupled to the main case. The pilot piston is equipped in the pilot case. One end of the lever is coupled to the pilot piston, and the other end of the lever is rotatably coupled to the stroking piston. The first spool is contacted with one side of the lever, and controls an exhausted flux.

Description

Regulator for axial piston pump

The present invention relates to a regulator of an axial piston pump.

In general, an excavator uses a rotary kinetic energy provided by an engine such as an internal combustion engine to drive a pump. Such pumps supply hydraulic oil that can be driven by actuators such as booms, arms, swing motors, and traveling motors, and a variable displacement pump having a variable discharge capacity, such as a swash plate type axial pump, is generally used.

In such a swash plate type axial pump, the flow rate of the hydraulic oil discharged from the pump is determined according to the inclination (slope angle) of the swash plate, and the inclination of the swash plate is configured to be adjusted by the operation of the regulator according to the pilot pressure.

That is, the flow rate output from the pump is changed according to the pilot pressure input. In the flow rate control method using the pilot pressure, a positive control (aka, static flow rate control or the flow rate) is increased in proportion to the pilot pressure input to the regulator. Posicon) and negative control (also known as float control or negative flow) in which the flow rate is reduced in inverse proportion to the pilot pressure input to the regulator.

The control method of such a regulator is determined depending on the use environment and use, or depends on the inherent characteristics of the manufacturer. Therefore, an excavator manufacturer selects and uses a positive control or negative control regulator.

In addition, such a positive control or negative control method has a significant difference in the coupling relationship with the pump and the configuration of the overall system itself, and accordingly, a regulator suitable for each is manufactured to be configured and used according to the corresponding method.

Therefore, manufacturers of regulators have to produce both positive control regulators and negative control regulators for each excavator manufacturer, and selectively combine them with a pump to form a corresponding system.

According to the prior art having such a configuration, from the standpoint of a regulator manufacturer, a separate regulator suitable for a positive control method or a negative control method must be produced separately, which causes a problem of high manufacturing cost. And, once a regulator is produced, it is structurally impossible to divert it in different ways when it is in stock. Therefore, the loss cost increases when inventory is generated.

In addition, for the manufacturer of the excavator, the positive control or negative control regulator suitable for the pump must be selected and assembled, and the entire system configuration must be changed according to the corresponding method. There is this.

SUMMARY OF THE INVENTION An object of the present invention is to provide a regulator of an axial piston pump which can be selectively changed to a positive control or a negative control regulator according to a direction in which a pilot valve composed of a pilot piston and a lever coupled thereto is coupled to a main case. will be.

The regulator of the axial piston pump according to an embodiment of the present invention, the main case forming an outer shape; A pilot valve which is selectively coupled to the main case, a pilot piston which is moved in accordance with an applied pilot pressure built into the pilot case, and a pilot valve having one end axially coupled to the pilot piston; A stroking piston which is provided inside the main case and is moved in accordance with the change of the tilt angle, and the other end of the lever is pivotally coupled to the other end; A first spool which is in contact with one side of the lever inside the main case and is moved according to the rotation of the lever to adjust the discharge flow rate of the pump, wherein the pilot valve is coupled to the main case; Positive or negative control can be selected.

In addition, a pivot part having a curved surface is formed at an end of the lever to be rotatable and inserted into the stroking piston, and the receiving part is formed at the stroking piston to open to the side to accommodate the pivot part.

In addition, the first spool is configured to be selectively connected to the large diameter chamber and the drain port of the pump or the discharge port of the pump in accordance with the movement by the lever.

In addition, the lever extends to the outside through the opening that is opened to the outside of the pilot case, and is inserted through the insertion passage of the main case opened upward of the stroking piston.

In addition, the pilot valve is configured to be coupled to the main case even when rotated in the opposite direction by the coupling means fastened to the main case through the pilot case.

In the regulator of the axial piston pump according to the present invention, one end is axially coupled to the pilot piston and the other end is a positive control or negative control type regulator according to the coupling direction of the pilot valve composed of a lever selectively coupled to the stroking piston. It is configured to be selectively changed to.

Therefore, the regulator in which the control method is determined by the coupling direction is mounted on the axial piston pump to implement a desired system in the manufacturer, thereby enabling the control of the flow rate according to the pilot pressure.

That is, the regulator having the same configuration can be mounted to the positive control pump, and the regulator having the same configuration can be mounted to the negative control pump by changing the coupling direction of the pilot valve.

Therefore, the production of the regulator having a single configuration can be mounted on the pump of various excavator manufacturers, so that the standardization of parts is possible, there is an effect that can reduce the manufacturing cost.

In addition, it is possible to configure the system in a positive control method or a negative control method by simply installing a regulator, thereby making it easier to assemble.

Further, by providing a regulator that can be selectively set to a positive control and a negative control, the excavator maker can use the regulator having a control method as needed, thereby improving the product utilization in the excavator maker.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments in which the spirit of the present invention is presented, and other embodiments included in the spirit of the present invention or other inventions which are degenerate by addition, modification, or deletion of other components are easily provided. Can suggest.

1 is a hydraulic circuit diagram of a regulator of an axial piston pump according to an embodiment of the present invention.

Referring to the drawings, a pair of pumps 10 connected to the motor 1 are rotated by a motor 1 such as an internal combustion engine, and the operating oil flows to the center bypass line 40 by the rotation of the pump 10. Through) can be supplied to the regulator 100 and the actuator and the drain tank.

The pair of pumps 10 and the regulator 100 is in a symmetrical form, the configuration is completely the same, so only the pump 10 and the regulator 100 provided on one side will be described in detail.

The pump 10 is similar to the structure of a general axial piston pump, and is configured by coupling a plurality of pistons 12 to the swash plate 20 whose inclination is adjusted, and the piston 12 is according to the regulator 100. The large diameter chamber 22 in which the pressure is adjusted and the small diameter chamber 24 to which the discharge pressure of the pump 10 is supplied are respectively provided.

Although not shown in detail, the swash plate 20 is rotated together according to the change of the inclination (tilt angle) of the swash plate 20 and is connected to the feedback lever 310 provided in the regulator 100 ( 30) is provided.

Meanwhile, the regulator 100 includes a pilot valve 200 including a pilot piston 220 to which pilot pressure is input and a lever 270 connected to the pilot piston 220, and a swash plate of the pump 10. 20) the stroking piston 320, which is moved by a feedback mechanism (feedback lever 310 and feedback cam 30) according to an inclination (slope angle), one end in contact with the lever 270 of the lever 270 The first spool 370 to selectively adjust the pressure of the large diameter chamber 22 in accordance with the rotation, and the compass piston (350) and the second spool (360) which are moved left and right according to the discharge pressure in the pump It is configured to include.

2 and 3 are longitudinal cross-sectional views when a regulator of an axial piston pump according to an embodiment of the present invention is used in a positive control manner, and the regulator will be described in more detail with reference to the accompanying drawings.

The regulator 100 is mounted on both sides of the housing of the pump 10, respectively, the regulator 100 on both sides are configured in the same configuration, and are mounted in a direction opposite to each other.

The regulator 100 is coupled to the pilot valve 200 to the main case 300 as a whole to form an overall appearance. At this time, the first case 370, the second spool 360, the stroking piston 320, the compass piston 350, etc., which will be described in detail below, are embedded in the main case 300, and the pilot Inside the case 210, the pilot piston 220 and the lever 270 is built.

Looking at this in more detail, the pilot valve 200 is coupled to the upper portion of the main case 300, it may be combined by rotating 180 ° in the horizontal direction from the top of the main case 300 according to the control method. .

The pilot valve 200 includes a pilot case 210 forming an outer shape, a pilot piston 220 mounted inside the pilot case 210, and a lever 270 connected to the pilot piston 220. .

The pilot case 210 forms an upper shape of the regulator 100, and the pilot piston 220 is disposed to be movable in a horizontal direction therein. In addition, a pilot spring 220 is provided inside the pilot case 210 to elastically support the pilot spring 220 and to adjust the elasticity of the pilot spring 220 at one end of the pilot case 210. Pilot cover 240 and the setting screw 242 is provided. In addition, the other end of the pilot case 210 is provided with a pilot port Pi for inputting a pilot pressure for the operation of the pilot piston 220.

Meanwhile, an opening 250 is formed at one side of the bottom surface of the pilot case 210. The opening 250 is a hole through which the lever 270, which will be described later, enters and exits, and is formed to communicate with the insertion passage 390 which will be described below. In addition, an oil seal 252 is provided at an outer circumference of the opening 250 to allow the opening 250 and the insertion passage 390 to be hermetically sealed when the pilot case 210 is coupled to the main case 300. More is provided.

In addition, the pilot valve 200 is coupled to the main case 300 by a coupling member. The coupling means 280 is configured to penetrate the pilot case 210 from above the pilot case 210, and a plurality of coupling means 280 is formed to be fastened to the main case 300.

In addition, the coupling means 280 rotates the pilot valve 200 in a horizontal direction so that the pilot valve 200 can be fixed even when coupled to the main case 300, the pilot valve 200 Are arranged at equal intervals from the centered portion during rotation of the.

In addition, a coupling pin 260 is provided at a corresponding position where the pilot case 210 and the main case 300 contact each other, so that the pilot valve 200 is coupled to the case 300 when the pilot valve 200 is coupled to the case 300. The position 200 is to be fixed so that the main case 300 can be coupled at the correct position.

That is, the pilot valve 200 is mounted so that the pilot port Pi is located on the right side when the regulator 100 is used in the positive control method (forward direction), and 180 ° in the horizontal direction when used in the negative method. It is rotated and mounted so that the pilot port Pi may be located on the left side (reverse direction). In addition, the pilot case 210 and the main case 300 are set by the coupling pin 260 so that the pilot case 210 and the main case 300 are coupled to each other, and are coupled by the coupling means 280.

The lever 270 allows the pilot piston 220 and the stroking piston 320 to move relative to each other, and the pressure of the large diameter chamber 22 can be adjusted by the first spool 370. It is axially coupled to one side of the pilot piston 220. Therefore, in a state where the pilot valve 200 is separated from the main case 300, the lever 270 is extended to the outside through the opening 250 in a state in which the lever 270 is coupled to the pilot piston 220. It is composed.

In addition, a pivot portion 272 is formed at the other end of the lever 270. The pivot part 272 is selectively inserted into the stroking piston 320 when the pilot case 210 is coupled to the main case 300, and is fixed to be rotatable. The circumferential surface is formed to have a curvature so that it can be detachably inserted into the receiving portion 322 formed in the stroking piston 320, which will be described below, and the lever 270 moves the pivot portion 272 in the inserted state. It is configured to be rotatable as a reference.

On the other hand, the inner lower portion of the main case 300 is provided in the feedback mechanism, that is, the feedback lever 310 mounted on the lower portion of the main case 300 and the swash plate 20 is interlocked with the feedback lever 310 The stroking piston 320 is moved by the feedback cam 30 is provided.

An upper portion of the stroking piston 320 has a receiving portion 322 in a shape that can accommodate the pivot portion 272, the lower portion is formed with an interference portion 324 to interfere with the feedback lever 310. In addition, an adjusting spring 321, an inspring 323, and an out spring 325 are provided inside the stroking piston 320 to adjust the movement of the stroking piston 320 by the compression force of these springs. Configured to do so.

One side (right side in FIG. 2) end of the main case 300 is provided with a cover 330 and an adjust screw 332 fastened to adjust the elasticity of the adjust spring 321, the main case ( The piston chamber 340, the compass piston 350, and the second spool 360 are provided in the left side of the stroking piston 320.

The compass piston 350 moves to the left and right according to the discharge pressure of the pump 10. When the discharge pressure of the pump 10 increases, the compass piston 350 moves to the right to the inspring 323 and the out spring 325. When the compression spring 321 is compressed and the discharge pressure of the pump 10 is reduced, the spring 325 moves to the left side by the elasticity of the spring 323, the out spring 325, and the adjustment spring 321. .

In addition, the second spool 360 in contact with the right end of the compass piston 350 moves left and right according to the movement of the compass piston 350, so that the Sv port of the Dr port or the pump 10 connected to the oil tank. It is selectively connected to the P1 _b port connected to the output port is configured to adjust the pressure of the large diameter chamber 22, by adjusting the tilt angle by the pressure control of the large diameter chamber 22 to adjust the discharge flow rate of the pump 10 It is configured to be adjustable.

On the other hand, the first spool 370 is provided on the upper portion of the main case 300. The Cl port connected to the large diameter chamber 22 is selectively connected to the Sv port or the P1 _a port connected to the output port of the pump 10, and one end of the first spool 370 (left end in FIG. 2). Is elastically supported by the return spring 372 inside the main case 300, the other end of the first spool 370 is formed to contact the side of the lever 270.

Accordingly, the first spool 370 in contact with the lever 270 moves left and right according to the rotation of the lever 270, and the large diameter chamber 22 moves along the left and right sides of the first spool 370. The Sv port is connected to the Dr and P1 _b ports.

Hereinafter, the operation of the regulator of the axial piston pump according to the embodiment of the present invention having the above configuration will be described.

The regulator 100 mounted in FIG. 2 is a configuration of the regulator 100 for controlling the flow rate in a positive control manner.

When the pilot pressure input to the pilot port Pi rises, the pilot piston 220 moves to the left and stops at a position balanced with the compression restoring force of the pilot spring 220.

When the pilot piston 220 is moved to the left side, the lever 270 is rotated counterclockwise with respect to the "A" point (the pivot part 272), and the rotation of the lever 270 Accordingly, the first spool 370 in contact with the lever 270 moves to the left side while compressing the return spring 372.

As the left side of the first spool 370 moves, the Cl port is connected to the Sv port, and is connected to the Dr port via the Sv port. Therefore, the pressure of the large diameter chamber 22 connected to the Cl port is reduced. On the other hand, in the state where the discharge pressure of the pump 10 is always provided to the small diameter chamber 24, the swash plate 20 is inclined by the pressure difference between the large diameter chamber 22 and the small diameter chamber 24. This results in increased tilt angle. When the tilt angle is increased, the stroke of the piston 12 is increased, and the flow rate discharged through the pump 10 is increased.

On the other hand, when the tilt angle is increased, the feedback cam 30, the feedback mechanism 310 and the feedback mechanism is rotated, the stroking piston 320 is terminated the interference with the feedback lever 310 is The spring 323 and the out spring 325 are moved to the right by the elastic restoring force.

When the stroking piston 320 is moved to the right, the lever 270 is moved in the counterclockwise direction based on the point "B", and the lever 270 is moved to the lever 270 according to the rotation of the lever 270. The first spool 370 is in contact with the return spring 372 to move to the right. Therefore, the first spool 370 is in a closed state with the first sleeve 380 formed in the main case 300 to maintain a constant flow rate.

On the other hand, when the pilot pressure input to the pilot port Pi is reduced, the pilot piston 220 is moved to the right, the lever is rotated clockwise based on the "A" point to the first spool 370 is moved to the right.

By moving to the right of the first spool 370, the Cl port is in communication with the P1 _a port connected to the discharge port of the pump 10, thereby increasing the pressure of the large diameter chamber. As the pressure of the large diameter chamber 22 increases, the tilt angle becomes smaller, and as the stroke angle decreases, the stroke of the piston 12 decreases, so that the discharged flow rate also decreases.

When the tilt angle is reduced, the stroking piston 320 is moved to the left by the feedback mechanism. By moving the left side of the stroking piston 320, the lever rotates clockwise based on the "B" point to move the first spool 370 to the left direction. As a result, the first spool 370 is closed with the first sleeve 380 to maintain a constant flow rate.

As shown in FIG. 4, the regulator 100 having the pilot valve 200 coupled in a direction having a positive control method is proportional to the pilot pressure input through the pilot port Pi, as illustrated in FIG. 4. The discharge flow rate discharged from can be increased.

On the other hand, in order for the regulator 100 to be used to control the flow rate in a negative control method, the coupling direction of the pilot valve 200 must be assembled in the reverse direction (the direction rotated by 180 ° with reference to FIG. 2), and This will be described with reference to the drawings.

5 is a longitudinal cross-sectional view when a regulator of an axial piston pump according to an embodiment of the present invention is used in a negative control manner.

In order to use the regulator 100 in a negative control method, when the pilot case 210 is mounted on the main case 300, the pilot port Pi is disposed to the left side.

Such a position is to rotate the pilot valve 200 by 180 ° in the above-described positive control method, it is possible to determine the flow rate control method only by selecting the coupling direction of the pilot valve 200 without additional work.

The pilot valve 200 is coupled to the main case 300 in a state where the regulator 100 is disposed so that the pilot port Pi faces to the left. In this case, the opening 250 communicates with the insertion passage 390, and the lever 270 is inserted into the receiving portion 322 of the stroking piston 320 through the insertion passage 390.

At this time, the coupling position of the pilot case 210 and the main case 300 is determined by the coupling pin 260, the pilot valve 200 is the main case by fastening the coupling means 280 Coupled to 300. By combining the pilot valve 200 and the main case 300, the opening 250 and the insertion passage 390 are hermetically sealed by an oil seal 252. At this time, the pivot 272 of the lever 270 is rotatable inside the receiving portion 322 is configured to rotate in accordance with the relative movement of the pilot piston 220 or the stroking piston 320. .

On the other hand, since the configuration of the inside of the main case 300 of the regulator 100 is the same as the structure of the regulator 100 of the positive control method described above, a detailed description thereof will be omitted.

On the other hand, when the pilot case 210 is coupled and the assembly of the regulator 100 for controlling the flow rate in a negative control method is completed, the regulator 100 is mounted on the corresponding pump 10 to be used.

The operation of the negative control regulator having such a configuration is as follows.

When the pilot pressure input from the pilot port Pi increases, the pilot piston moves to the right to rotate the lever clockwise with respect to the “A” point, and by the rotation of the lever 270. The first spool 370 moves to the right to connect the Cl port and P1 _a .

Therefore, the pressure of the large diameter chamber 22 is increased, and the stroke of the piston 12 is shortened by increasing the pressure of the large diameter chamber 22, so that the flow rate discharged from the pump 10 is reduced.

As the pressure of the large diameter chamber 22 increases, the tilt angle becomes smaller, and as the tilt angle becomes smaller, the stroking piston 320 is moved to the left by the feedback mechanism to move the lever 270 to " Rotate clockwise around the B "point. As the lever 270 rotates, the first spool 370 is moved to the left side, and the first spool 370 is closed in the first sleeve 380 to maintain a constant flow rate. .

On the other hand, when the pilot pressure input from the pilot port Pi is reduced, the piston 12 is moved to the left to rotate the lever 270 counterclockwise based on the "A" point, The first spool 370 is moved to the left side by the rotation of the lever 270 so that the Cl port and the Sv port may be connected to each other and communicate with the oil tank through the Dr port.

Therefore, the pressure of the large diameter chamber 22 is reduced, and the stroke of the piston 12 is lengthened due to the pressure reduction of the large diameter chamber 22, so that the flow rate discharged from the pump 10 is increased.

As the pressure of the large diameter chamber 22 decreases, the tilt angle increases, and as the tilt angle increases, the stroking piston 320 is moved to the right by the feedback mechanism to move the lever 270 to " Rotate counterclockwise from the point B ”. As the lever 270 rotates, the first spool 370 is moved to the right and the first spool 370 is closed in the first sleeve 380 to maintain a constant flow rate. .

As described above, when the pilot valve 200 is coupled in a direction in which the regulator 100 has a negative control method, the pump 10 is discharged as the pilot pressure input through the pilot port Pi increases. It can be seen that the flow rate decreases, and the pilot pressure and the discharge flow rate of the pump 10 are inversely proportional.

1 is a hydraulic circuit diagram of a regulator of an axial piston pump according to an embodiment of the present invention.

2 is a longitudinal sectional view when the regulator of the axial piston pump according to the embodiment of the present invention is used in a positive control manner;

3 is a longitudinal sectional view when a regulator of an axial piston pump according to an embodiment of the present invention is used in a positive control manner;

Figure 4 is a graph showing the flow rate change according to the pilot pressure when the regulator of the axial piston pump according to an embodiment of the present invention is used in a positive control method.

5 is a longitudinal sectional view when a regulator of an axial piston pump according to an embodiment of the present invention is used in a negative control manner;

Figure 6 is a graph showing the flow rate change according to the pilot pressure when the regulator of the decant piston pump according to the embodiment of the present invention is used in a negative control method.

Claims (5)

A main case forming an appearance; A pilot valve which is selectively coupled to the main case, a pilot piston which is moved in accordance with an applied pilot pressure built into the pilot case, and a pilot valve having one end axially coupled to the pilot piston; It is provided on the inside of the main case and moved in accordance with the change of the tilt angle, the stroking piston that the other end of the lever is pivotally coupled, and in contact with one side of the lever inside the main case, the rotation of the lever Is moved according to the first spool configured to control the discharge flow rate of the pump, A positive piston pump regulator capable of selecting a positive control or a negative control according to the direction in which the pilot valve is coupled to the main case. The method of claim 1, An end portion of the lever is formed with a pivot having a curved surface inserted into the stroking piston to be rotatable, The axial piston pump regulator is formed in the stroking piston, the receiving portion for each side opening to receive the pivot portion. The method of claim 1, The first spool is configured to be selectively connected to the large diameter chamber and the drain port of the pump or the discharge port of the pump in accordance with the movement by the lever. The method of claim 1, The lever extends to the outside through the opening that is opened to the outside of the pilot case, the regulator of the axial piston pump is inserted through the insertion passage of the main case opened upward of the stroking piston. The method of claim 1, The pilot valve regulator of the axial piston pump is configured to be coupled to the main case even when rotated in the opposite direction by the coupling means fastened to the main case through the pilot case.

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