Bidirectional cushion valve structure for closed loop

Abstract

The bidirectional cushion valve structure comprises an oil way body, and a first oil way and a second oil way are formed in the oil way body; the two throttle valve assemblies are respectively a first throttle valve assembly and a second throttle valve assembly, the first throttle valve assembly is communicated with the first oil way, and the second throttle valve assembly is communicated with the second oil way; the variable arm is arranged on one side of the oil way body, the variable arm is mechanically connected with an external variable handle, the variable arm switches the high-pressure output state and the low-pressure input state of the first oil way and the second oil way by adjusting the swing angle, and the oil way is arranged on the variable arm, so that when the variable direction is changed, the variable arm can adjust the swing angle of the first oil way and the second oil way. The throttling valve is switched and connected with different buffering oil ways on the variable arm, and a throttling loop is always kept to be arranged on the low-pressure side of the closed type hydraulic system. In this way, the requirement for the buffering function of the throttling valve is met, and the problem of efficiency loss caused by the throttling valve can be avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of transmission, and relates to a bidirectional buffer valve structure for a closed loop. BACKGROUND

[0002] In order to reduce or eliminate hydraulic impact caused by sudden change of working conditions, a conventional closed hydraulic system increases a throttling passage with a drain chamber on a single main oil passage. The throttling passage is used to achieve pressure relief when a pressure impact wave peak caused by sudden change of working conditions, and is used to achieve oil supplement when a pressure impact wave caused by sudden change of working conditions, so as to reduce or eliminate hydraulic impact caused by sudden change of working conditions, and the adjustment degree is determined by the size of the throttling hole. The throttling method of the single main oil passage of the conventional method can only adjust hydraulic impact in a single driving direction, and plays a positive role on the oil suction side, but when the reverse drive is performed, the throttling oil passage is directly communicated with the high-pressure side, direct efficiency loss is caused, and a negative effect is caused, so that the system / product is heated and energy is lost. SUMMARY

[0003] The present application is aimed at the above-mentioned problems existing in the prior art, and provides a bidirectional buffer valve structure for a closed loop.

[0004] The purpose of the present application can be achieved by the following technical scheme: a bidirectional buffer valve structure for a closed loop, comprising an oil passage body, a first oil passage and a second oil passage are formed in the oil passage body; two throttling valve assemblies, which are a first throttling valve assembly and a second throttling valve assembly, the first throttling valve assembly is in communication with the first oil passage, and the second throttling valve assembly is in communication with the second oil passage; a variable arm, which is arranged on one side of the oil passage body, the variable arm is mechanically connected with an external variable handle, and the variable arm switches high-pressure output and low-pressure input states of the first oil passage and the second oil passage according to an adjustment swing angle; a first oil groove and a second oil groove are formed in the variable arm; the variable arm has a left limit working position and a right limit working position, when the variable arm is in the left limit working position, the first oil groove is disconnected with the first throttling valve assembly, and the second oil groove is in communication with the second throttling valve assembly, and the first oil passage is a high-pressure oil passage; conversely, when the variable arm is in the right limit working position, the second oil groove is disconnected with the second throttling valve assembly, and the first oil groove is in communication with the first throttling valve assembly, and the second oil passage is a high-pressure oil passage.

[0005] In the bidirectional buffer valve structure for a closed loop, first and second mid-grooves are respectively formed in the first and second oil grooves, and the first mid-groove is arranged in line with the second mid-groove.

[0006] In the above-mentioned bidirectional buffer valve structure for a closed circuit, the throttle valve assembly includes a valve body, a throttle orifice on the valve body, a throttle channel connected to the oil circuit on the valve body, a spring in the throttle channel, and a filter screen on the side of the throttle channel near the throttle orifice.

[0007] In the above-mentioned bidirectional buffer valve structure for a closed loop, both the first oil groove and the second oil groove are arranged in an arc shape. When the variable arm is adjusted in angle, the throttling orifice on the valve body of the first throttling valve is always located on the arc-shaped path of the first oil groove, and the throttling orifice on the valve body of the second throttling valve is always located on the arc-shaped path of the second oil groove.

[0008] In the above-described bidirectional buffer valve structure for a closed loop, when the variable arm is in the left limit working position, the first throttle orifice is disengaged from the first oil tank, and the second throttle orifice is connected to the right end region of the second oil tank. When the variable arm is in the right limit working position, the second throttle orifice is disengaged from the second oil tank, and the first throttle orifice is connected to the left end region of the first oil tank.

[0009] In the above-mentioned bidirectional buffer valve structure for a closed circuit, the oil circuit body is provided with an oil pump mounting surface and a motor mounting surface, and the axes of the oil pump mounting surface and the motor mounting surface are arranged at right angles.

[0010] In the above-mentioned bidirectional buffer valve structure for a closed circuit, a first mounting hole and a second mounting hole are provided on one side of the oil circuit body. The first mounting hole is connected to the first oil circuit, and the second mounting hole is connected to the second oil circuit. The first throttle valve assembly is located in the first mounting hole, and the second throttle valve assembly is located in the second mounting hole.

[0011] Compared with the prior art, the present invention sets up an oil circuit on the variable arm. When the direction of the variable changes, the throttle valve switches and connects different buffer oil circuits on the variable arm accordingly, always keeping the throttle circuit set on the low-pressure side of the closed hydraulic system. This not only realizes the buffer function requirement of the throttle valve, but also avoids the efficiency loss problem caused by the throttle valve. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is an exploded schematic diagram of the throttle valve assembly of the present invention; Figure 4 This is a cross-sectional view of the throttle valve assembly of the present invention; Figure 5This is a schematic diagram of the right limit working position of the present invention; Figure 6 This is a schematic diagram of the middle position of the present invention; Figure 7 This is a schematic diagram of the left limit working position of the present invention.

[0013] In the diagram, 1. Oil circuit body; 2. First oil circuit; 3. Second oil circuit; 4. First throttle valve assembly; 5. Second throttle valve assembly; 6. Variable arm; 7. First oil groove; 8. Second oil groove; 9. First neutral groove; 10. Second neutral groove; 51. Valve body; 52. Throttling orifice; 53. Throttling channel; 54. Spring; 55. Filter screen; 6. First mounting hole; 7. Second mounting hole. Detailed Implementation

[0014] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments. Example

[0015] like Figures 1 to 7 As shown, a bidirectional buffer valve structure for a closed circuit includes an oil circuit body 1, on which an oil pump mounting surface and a motor mounting surface are provided, and the axes of the oil pump mounting surface and the motor mounting surface are arranged at right angles.

[0016] The oil circuit body 1 has a first oil circuit 2 and a second oil circuit 3. A first mounting hole 6 and a second mounting hole 7 are provided on one side of the oil circuit body 1. The first mounting hole 6 is connected to the first oil circuit 2, and the second mounting hole 7 is connected to the second oil circuit 3. Throttling valve assemblies are provided in both the first mounting hole 6 and the second mounting hole 7. The throttle valve assembly in the first mounting hole 6 and the second mounting hole 7 are respectively provided with a first throttle valve assembly and a second throttle valve assembly 5.

[0017] In this embodiment, the first throttle valve assembly 4 and the second throttle valve assembly 5 are the same. Taking the first throttle valve assembly 4 as an example, the throttle valve assembly includes a valve body 51 disposed in the first mounting hole 6. The valve body 51 has a throttle hole 52 and a throttle channel 53 connected to the first oil circuit 2. A spring 54 is disposed in the throttle channel 53. A filter screen 55 is also disposed on the side of the throttle channel 53 near the throttle hole 52. The filter screen 55 can filter the transmission medium to avoid contamination of the transmission medium and affect the normal operation of the valve body 51 and the hydraulic system. In this embodiment, the transmission medium is hydraulic oil or machine oil.

[0018] A variable arm 6 is provided on one side of the oil circuit body 1. The variable arm 6 has a first oil groove 7 and a second oil groove 8. The variable arm 6 has a left limit working position and a right limit working position. When the variable arm 6 is in the left limit working position, the first oil groove 7 is disconnected from the first throttle valve assembly 4, and the second oil groove 8 is connected to the second throttle valve assembly 5. The first oil circuit 2 is a high-pressure oil circuit. Conversely, when the variable arm 6 is in the right limit working position, the second oil groove 8 is disconnected from the second throttle valve assembly 5, and the first oil groove 7 is connected to the first throttle valve assembly 4. The second oil circuit 3 is a high-pressure oil circuit.

[0019] In this embodiment, the left limit position is the maximum angle position of the variable arm 6 rotating to the left, and the right limit position is the maximum angle position of the limiting arm rotating to the right.

[0020] The first oil tank 7 is connected to the first oil circuit 2 through the throttling hole 52 and throttling channel 53 on the valve body 51, and the second oil tank 8 is connected to the second oil circuit 3 through the throttling hole 52 and throttling channel 53 on the valve body 51.

[0021] The first oil tank 7 and the second oil tank 8 are respectively provided with a first neutral position groove 9 and a second neutral position groove 10. The first neutral position groove 9 and the second neutral position groove 10 are arranged in a straight line. When the variable arm 6 is working in the neutral position, the first throttle valve assembly 4 is connected to the first oil tank 7, and the second throttle valve is connected to the second oil tank 8. At this time, the hydraulic variable piston pump has no output, and the hydraulic system does not work, thus avoiding premature output of the piston pump due to the clearance of the variable mechanism, which could lead to malfunction of the hydraulic system. Figure 6 As shown, the angle θ between the tangents at the left and right extreme positions and the center of the variable arm is set to adjust the dead zone angle. In practice, operators can select variable arms with different angles θ according to the actual situation, avoiding premature output of the piston pump due to the clearance of the variable mechanism, which could cause malfunctions in the hydraulic system. Especially when applied to vehicle drive, a reasonable dead zone angle setting can prevent the vehicle from creeping.

[0022] Both the first oil tank 7 and the second oil tank 8 are arc-shaped. When the variable arm 6 is adjusted in angle, the throttling orifice 52 on the valve body 51 of the first throttling valve is always located on the arc-shaped path of the first oil tank 7, and the throttling orifice 52 on the valve body 51 of the second throttling valve is always located on the arc-shaped path of the second oil tank 8.

[0023] When the variable arm 6 is working at its left limit position, the first oil circuit 2 is the high-pressure oil circuit output by the plunger pump. The first throttle valve assembly 4 is separated from the first oil tank 7, and the first throttle valve circuit is disconnected to avoid system leakage and efficiency loss. The second oil circuit 3 is the low-pressure oil circuit input by the plunger pump. The throttle orifice 52 on the valve body 51 of the second throttle valve is located at the rightmost position of the second oil tank 8. The second throttle valve assembly 5 and the second oil circuit 3 are connected throughout their full stroke in this working direction. Opening the throttle valve circuit can reduce the hydraulic system shock caused by sudden load changes.

[0024] When the variable arm 6 is working at its right limit position, the first oil circuit 2 is the low-pressure oil circuit for the piston pump input. The throttle orifice 52 on the first throttle valve body 51 is located at the leftmost position of the first oil groove 7. The first throttle valve assembly 4 is fully connected to the first oil groove 7 in this working direction. Opening the circuit of the first throttle valve assembly 4 can reduce the hydraulic system shock caused by sudden load changes. The second oil circuit 3 is the high-pressure oil circuit for the piston pump output. The second throttle valve assembly 5 is separated from the second oil circuit 3. The throttle valve circuit is disconnected to avoid system leakage and efficiency loss.

[0025] The variable arm 6 is mechanically connected to an external variable handle, synchronously driving the variable swashplate to swing at a corresponding angle to adjust the variable angle of the hydraulic piston pump and the direction of the working oil circuit, thereby achieving high-low pressure switching between the first oil circuit 2 and the second oil circuit 3. As the working direction of the variable arm 6 changes, the working position of the throttle circuit also changes accordingly, always keeping the throttle circuit on the low-pressure side of the closed hydraulic system. This fulfills the buffering function requirement of the throttle valve while avoiding the efficiency loss problem caused by the throttle valve.

[0026] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A bidirectional buffer valve structure for a closed loop, characterized by, The oil passage body (1) is provided with a first oil passage (2) and a second oil passage (3); Two throttle valve assemblies, namely a first throttle valve assembly (4) and a second throttle valve assembly (5), the first throttle valve assembly (4) is communicated with the first oil passage (2), and the second throttle valve assembly (5) is communicated with the second oil passage (3); A variable arm (6) is arranged on one side of the oil passage body, the variable arm (6) is mechanically connected with an external variable handle, and the variable arm (6) is used for switching the high-pressure output and low-pressure input states of the first oil passage (2) and the second oil passage (3) according to the adjustment of the swing angle. The variable arm (6) is provided with a first oil groove (7) and a second oil groove (8); the variable arm (6) has a left limit working position and a right limit working position; when the variable arm (6) is in the left limit working position, the first oil groove (7) is disconnected with the first throttle valve assembly (4), the second oil groove (8) is communicated with the second throttle valve assembly (5), and the first oil passage (2) is a high-pressure oil passage; conversely, when the variable arm (6) is in the right limit working position, the second oil groove (8) is disconnected with the second throttle valve assembly (5), the first oil groove (7) is communicated with the first throttle valve assembly (4), and the second oil passage (3) is a high-pressure oil passage.

2. A bidirectional snubber valve structure for a closed loop according to claim 1, characterized in that: The first oil groove (7) and the second oil groove (8) are respectively provided with a first middle groove (9) and a second middle groove (10), and the first middle groove (9) and the second middle groove (10) are arranged in a straight line.

3. A bidirectional snubber valve structure for a closed loop according to claim 2, characterized in that: The throttle valve assembly comprises a valve body (51), the valve body (51) is provided with a throttle hole (52), the valve body (51) is provided with a throttle channel (53) communicated with the oil passage, the throttle channel (53) is provided with a spring (54), and the side, close to the throttle hole (52), of the throttle channel (53) is further provided with a filter screen (55).

4. A bidirectional snubber valve structure for a closed loop according to claim 3, characterized in that: The first oil groove (7) and the second oil groove (8) are both arranged in an arc shape, when the variable arm (6) is adjusted in angle, the throttle hole (52) on the first throttle valve body (51) is always located on the arc path of the first oil groove (7), and the throttle hole (52) on the second throttle valve body (51) is always located on the arc path of the second oil groove (8).

5. A bidirectional snubber valve structure for a closed loop according to claim 4, characterized in that: When the variable arm (6) is in the left limit working position, the first throttle hole (52) is disconnected with the first oil groove (7), and the second throttle hole (52) is communicated with the right end area of the second oil groove (8); when the variable arm (6) is in the right limit working position, the second throttle hole (52) is disconnected with the second oil groove (8), and the first throttle hole (52) is communicated with the left end area of the first oil groove (7).

6. A bidirectional snubber valve structure for a closed loop according to claim 5, characterized in that: The oil passage body (1) is provided with an oil pump mounting surface and a motor mounting surface, and the axes of the oil pump mounting surface and the motor mounting surface are arranged at right angles.

7. A bidirectional snubber valve structure for a closed loop according to claim 6, characterized in that: The oil passage body (1) is provided with a first mounting hole (6) and a second mounting hole (7) on one side, the first mounting hole (6) is communicated with the first oil passage (2), the second mounting hole (7) is communicated with the second oil passage (3), the first throttle valve assembly (4) is located in the first mounting hole (6), and the second throttle valve assembly (5) is located in the second mounting hole (7).

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