counterbalance valve

Abstract

A balance valve, comprising: a valve body, the valve body is sequentially provided with a pilot valve core, a main valve core and an elastic element cavity in the main valve cavity in the axial direction, the pilot valve core and the main valve core move along the axial direction of the main valve cavity to control the on-off of the oil path from the load oil port to the working oil port; a valve sleeve abuts against the main valve core to form a sealing structure, the valve sleeve and the main valve core have a shaft hole fitting area, the shaft hole fitting area is matched with the main valve core through a shaft hole gap, and the shaft hole fitting area is located between the sealing structure and the load oil port; a damping assembly is arranged in the elastic element cavity and comprises a damping piston and a damping sleeve, the damping piston is connected with the main valve core, the damping piston is provided with a through-flow hole, the through-flow hole is communicated with the elastic element cavity and a cavity in the damping piston, and the damping piston moves towards the damping sleeve under the pushing of the main valve core to disconnect the through-flow hole and the elastic element cavity. The balance valve provided by the embodiment of the utility model is beneficial to realize stable opening of the balance valve without shaking.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic valve technology, and in particular to a balancing valve. Background Technology

[0002] In the field of engineering machinery, most working mechanisms are driven by hydraulic transmission. This means that the engine drives the hydraulic pump to provide hydraulic energy, which is then supplied to the hydraulic cylinder or hydraulic motor via a hydraulic control valve to provide flow and maximum pressure to support the action, thereby completing the action of the mechanical equipment.

[0003] Balance valves, with their functions of load holding, load reduction, and unidirectional conduction, play a crucial role in hydraulic control systems. During the opening process, a sudden surge in system oil supply can cause a sharp increase in the valve's pilot pressure, leading to excessive valve spool opening and resulting in a large valve orifice opening. This creates an oscillation effect, causing the balance valve to frequently vibrate during operation. Currently, a throttling damping orifice is typically added to the valve pilot to slow the opening speed. However, on the one hand, to achieve this slowing effect, the throttling damping orifice is generally small and prone to clogging, affecting the reliability of the balance valve; on the other hand, while the throttling damping orifice affects the speed at which pilot oil enters the pilot port, it does not affect the movement of the valve spool, still failing to prevent the valve orifice from opening too large in the initial opening phase.

[0004] Therefore, there is an urgent need to provide a balancing valve that can slow down the opening speed of the balancing valve and solve the problem of vibration during startup. Utility Model Content

[0005] The technical problem solved by this utility model is to provide a balancing valve that can slow down the opening speed of the balancing valve, which helps to solve the problem of balancing valve vibration.

[0006] To solve the above-mentioned technical problems, this utility model provides a balancing valve, comprising: a valve body, wherein the valve body is provided with a main valve chamber, a control oil port, a load oil port, and a working oil port; a pilot valve core, a main valve core, and an elastic element cavity are sequentially arranged axially within the main valve chamber; the pilot valve core and the main valve core are adapted to move axially along the main valve chamber to control the on / off state of the oil passage from the load oil port to the working oil port; and a valve sleeve, wherein the valve sleeve is adapted to abut against the main valve core to form a sealing structure; the valve sleeve and the main valve core have a shaft hole mating area, and the valve sleeve in the shaft hole mating area... The main valve core is fitted with a shaft hole clearance, and the shaft hole fit area is located between the sealing structure and the load port; a damping assembly is disposed in the cavity of the elastic element, and the damping assembly includes a damping piston and a damping sleeve. The damping piston is connected to the main valve core, and a flow passage is provided on the damping piston. The flow passage communicates with the cavity of the elastic element and the cavity inside the damping piston. The damping piston is adapted to move in the opposite direction to the damping sleeve under the push of the main valve core to disconnect the passage between the flow passage and the cavity of the elastic element.

[0007] Optionally, the damping piston and the damping sleeve are fitted with a shaft-hole clearance fit.

[0008] Optionally, the width of the shaft hole mating area in the axial direction of the main valve cavity is greater than or equal to the diameter of the flow passage.

[0009] Optionally, the main valve core has a tapered sealing surface, and the valve sleeve has an annular sealing surface, with the tapered sealing surface abutting against the annular sealing surface to form the sealing structure.

[0010] Optionally, it further includes: a pressure regulating screw, which is disposed at the bottom of the elastic element cavity; a first elastic element, which is disposed in the elastic element cavity, one end of the first elastic element being connected to the damping piston, and the other end of the first elastic element being connected to the pressure regulating screw.

[0011] Optionally, a second elastic element may also be included, one end of which is connected to the valve sleeve.

[0012] Optionally, the gap between the main valve chamber and the shaft hole of the main valve core forms a first channel, and the first channel connects the elastic element cavity and the working oil port.

[0013] Optionally, it also includes a hydraulic control chamber, which is connected to the control port, and the pilot valve core is located in the hydraulic control chamber, forming a radial seal between the pilot valve core and the hydraulic control chamber.

[0014] Compared with the prior art, the technical solution of this utility model embodiment has the following beneficial effects:

[0015] The balance valve provided by this technical solution incorporates a damping assembly within the elastic element cavity. The flow orifice of the damping assembly connects to the internal cavity. When the balance valve opens in reverse, pilot oil enters through the control port, pushing the pilot valve core, main valve core, and damping piston. The damping piston and damping sleeve move towards each other, closing the flow orifice. Oil in the cavity flows outward through the shaft hole gap between the damping piston and damping sleeve, thus creating a damping effect that slows the opening speed of the balance valve. Simultaneously, a shaft hole clearance fit is formed between the main valve core and the valve sleeve. During the damping process, the presence of this shaft hole fit area prevents the valve sleeve and main valve core from rapidly separating, preventing the valve opening from being too sudden. This contributes to the stable opening of the balance valve and reduces vibration. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural diagram of the balance valve in one embodiment of the present invention;

[0017] Figure 2 yes Figure 1 An enlarged schematic diagram of the structure within the dashed box shown. Detailed Implementation

[0018] As described in the background section, to address the vibration issue during the initial opening of a balance valve, a throttling orifice is typically added to the pilot port to slow down the entry of pilot oil into the valve. However, this method of using a throttling orifice to reduce the valve's opening speed is still insufficient. Firstly, if the orifice diameter is too large, it cannot effectively slow down the oil flow; if the orifice diameter is too small, it is prone to clogging, causing the balance valve to malfunction and affecting its stability. Secondly, the throttling orifice only slows down the entry of pilot oil into the valve but does not impede the movement of the valve core.

[0019] To address the aforementioned problems, this utility model provides a balancing valve. The balancing valve has a pilot valve core, a main valve core, and an elastic element cavity sequentially arranged within its main valve chamber. A damping assembly is installed within the elastic element cavity, comprising a damping piston and a damping sleeve. A flow passage on the damping piston connects the elastic element cavity and the cavity within the damping piston. When the balancing valve opens in the reverse direction, pilot oil enters the pilot port of the balancing valve, pushing the pilot valve core and the main valve core to move axially along the main valve chamber. The damping piston, pushed by the main valve core, moves in opposite directions against the damping sleeve until the flow passage disconnects from the elastic element cavity. At this point, the oil in the cavity flows outward along the gap between the damping piston and the damping sleeve, thus providing a damping effect and slowing the opening speed of the balancing valve. In addition, since the valve sleeve and main valve core have a shaft hole mating area between the sealing structure and the load port, during the damping process, the oil in the load port slowly passes through the shaft hole mating area due to the existence of the shaft hole mating area, and the valve sleeve and main valve core will not separate quickly, thus avoiding the valve opening too suddenly and helping to solve the shaking problem in the initial stage of the balance valve opening.

[0020] To make the above-mentioned objectives, features and beneficial effects of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0021] Figure 1 This is a cross-sectional structural diagram of the balance valve in one embodiment of the present invention; Figure 2 yes Figure 1 An enlarged schematic diagram of the structure within the dashed box shown.

[0022] Reference Figure 1 and Figure 2 The balance valve 1 includes a valve body 10, on which a main valve chamber 11, a control port P, a load port C, and a working port V are provided. A main valve core 21, a pilot valve core 30, and an elastic element cavity 22 are provided in the main valve chamber 11. The pilot valve core 30, the main valve core 21, and the elastic element cavity 22 are arranged sequentially along the axial direction X of the main valve chamber 11. The pilot valve core 30 and the main valve core 21 are adapted to move along the axial direction X of the main valve chamber 11 to control the opening and closing of the oil passage from the load port C to the working port V.

[0023] Valve sleeve 41, the valve sleeve 41 is adapted to abut against the main valve core 21 to form a sealing structure, the valve sleeve 41 and the main valve core 21 have a shaft hole mating area 50, the valve sleeve 41 and the main valve core 21 in the shaft hole mating area 50 adopt a shaft hole clearance fit, the shaft hole mating area 50 is located between the sealing structure and the load port C;

[0024] A damping assembly 60 is disposed within the elastic element cavity 22. The damping assembly 60 includes a damping piston 61 and a damping sleeve 62. The damping piston 61 is connected to the main valve core 21. The damping piston 61 is provided with a flow passage 63, which communicates with the elastic element cavity 22 and the cavity 64 within the damping piston 61. The damping piston 61 is adapted to move in opposite directions to the damping sleeve 62 under the push of the main valve core 21, thereby disconnecting the connection between the flow passage 63 and the elastic element cavity 22.

[0025] The balance valve 1 also includes a hydraulic control chamber 31, the control port P is connected to the hydraulic control chamber 31, the pilot valve core 30 is located inside the hydraulic control chamber 31, the pilot valve core 30 is tightly attached to the inner wall of the hydraulic control chamber 31, and a radial seal is formed by the sealing element.

[0026] In this embodiment, one end of the main valve core 21 is connected to the pilot valve core 30, and the other end of the main valve core 21 is connected to the damping piston 61. Under the push of the pilot oil entering from the control port P, the pilot valve core 30 moves along the axial direction X of the main valve chamber 11, and at the same time pushes the main valve core 21 and the damping piston 61 to move along the axial direction X of the main valve chamber 11.

[0027] During the movement of the pilot valve core 30, the main valve core 21, and the damping piston 61 along the axial direction X of the main valve chamber 11, the damping piston 61 and the damping sleeve 62 move towards each other. The flow passage 63 will be gradually covered by the damping sleeve 62 until the connection between the cavity 64 and the elastic element cavity 22 is broken. At this time, the oil in the cavity 64 flows outward through the gap between the damping sleeve 62 and the damping piston 61, opposite to the opening direction of the balance valve 1, thereby achieving the damping effect.

[0028] In this embodiment, the damping piston 61 and the damping sleeve 62 are fitted with a shaft hole clearance. Compared with a damping hole, the shaft hole clearance fit eliminates the risk of blockage between the damping piston 61 and the damping sleeve 62, thus improving the reliability of the damping assembly 60.

[0029] The pilot valve core 30, the main valve core 21, and the damping piston 61 move along the axial direction X of the main valve chamber 11. The sealing structure between the valve sleeve 41 and the main valve core 21 separates. During the damping process, the flow passage is gradually covered by the damping sleeve 62. Through the shaft hole mating area 50 of the valve sleeve 41 and the main valve core 21, the valve sleeve 41 and the main valve core 21 form a shaft hole clearance fit for a certain stroke. The pilot oil of the control port P and the oil of the load port C can only slowly pass through the shaft hole mating area 50, which can prevent the valve port from opening suddenly and reduce the vibration of the balance valve caused by the excessive opening speed.

[0030] In this embodiment, the width of the shaft hole mating area 50 in the axial direction X of the main valve cavity 11 is greater than or equal to the diameter of the flow passage 63, so as to ensure that the valve port will not suddenly open during the damping process.

[0031] Continue to refer to Figure 1 The balance valve 1 further includes a first elastic element 23 and a pressure regulating screw 24. The first elastic element 23 is disposed in the elastic element cavity 22, and the pressure regulating screw 24 is disposed at the bottom of the elastic element cavity 22. One end of the first elastic element 23 is connected to the damping piston 61, and the other end of the first elastic element 23 is connected to the pressure regulating screw 24. The pressure regulating screw 24 is used to fix the first elastic element 23.

[0032] In this embodiment, when the damping piston 61 is subjected to pressure, it pushes the first elastic element 23 to compress the first elastic element 23.

[0033] In this embodiment, the first elastic element 23 is a spring.

[0034] In this embodiment, the balance valve 1 further includes a sleeve 13, which is connected to the valve body 10. A first channel 12 is provided on the sleeve 13, which connects the elastic element cavity 22 and the working oil port V.

[0035] In this embodiment, when the first elastic element 23 is compressed, the hydraulic oil in the elastic element cavity 22 can be discharged to the working oil port V through the first channel 12.

[0036] Continue to refer to Figure 1 The balance valve 1 further includes a second elastic element 42, one end of which is connected to the valve sleeve 41, and the other end of which is fixedly disposed. When the valve sleeve 41 is subjected to oil pressure, it pushes the second elastic element 42 to compress.

[0037] In this embodiment, the second elastic element 42 is a spring.

[0038] refer to Figure 2 In this embodiment, the main valve core 21 has a conical sealing surface 210, and the valve sleeve 41 has an annular sealing surface 410. The conical sealing surface 210 and the annular sealing surface 410 abut against each other to form the sealing structure, thereby disconnecting the oil passage between the load port C and the working port V. When the valve sleeve 41 is separated from the main valve core 21, the sealing structure is separated, and the oil passage between the load port C and the working port V is connected.

[0039] In this embodiment, when the balance valve 1 is opened in the forward direction, the oil enters the main valve chamber 11 of the balance valve 1 from the working oil port V, pushes the valve sleeve 41 to compress the second elastic element 42, the valve sleeve 41 separates from the main valve core 21, and the oil flows from the working oil port V to the load oil port C, realizing the one-way flow function of the balance valve 1.

[0040] In this embodiment, when the balance valve 1 is opened in reverse, hydraulic oil enters the balance valve 1 from the load port C and acts on the main valve core 21. In addition, the pilot oil at the control port P enters the hydraulic control chamber 31 of the balance valve 1 and acts on the pilot valve core 30. When the sum of the pressure acting on the pilot piston 30 (i.e. the balance valve pilot opening pressure) and the pressure acting on the main valve core 21 is greater than the set pressure of the first elastic element 23 of the balance valve 1, the pilot valve core 30 can be pushed, causing the main valve core 21 to separate from the valve sleeve 41, thereby opening the oil passage from the load port C to the working port V.

[0041] In this embodiment, when the main valve core 21 moves, it pushes the damping piston 61 to compress the first elastic element 23. The damping piston 61 and the damping sleeve 62 move in opposite directions. The flow hole 63 is blocked by the damping sleeve 62, which disconnects the passage to the elastic element cavity 22. The oil in the cavity 64 can only flow out through the gap between the damping piston 61 and the damping sleeve 62. The flow direction of the oil in the cavity 64 is opposite to the movement direction of the main valve core 21, thereby playing a damping role and slowing down the opening speed of the balance valve. In addition, because there is a shaft hole mating area 50 between the sealing structure and the load port C, and the valve sleeve 41 and the main valve core 21 in the shaft hole mating area 50 adopt a shaft hole clearance fit, during the damping process, that is, during the process of the flow hole gradually closing, even if the sealing structure of the main valve core 21 and the valve sleeve 41 separates, the oil needs to slowly pass through the shaft hole mating area 50 due to the existence of the shaft hole clearance fit. This can prevent the valve port from opening too suddenly, achieve the effect of slow opening of the balance valve, and help the balance valve to open stably without shaking.

[0042] In this embodiment, when the balance valve 1 is closed, oil does not enter through the control port P. Under the elastic force of the first elastic element 23, the main valve core 21 is gradually closed. At this time, the cavity 64 is evacuated into a vacuum, and atmospheric pressure cannot hinder the elastic force from pushing the main valve core 21. Therefore, the closing speed of the main valve core 21 is completely unaffected. After the main valve core 21 is reset, the flow hole 63 reconnects with the elastic element cavity 22, and the oil in the elastic element cavity 22 can re-enter the cavity 64 through the flow hole 63 to form a damping effect when the balance valve 1 opens in the reverse direction next time.

[0043] In this embodiment, the damping component 60 is disposed in the elastic element cavity 22 and integrated with other components of the balance valve 1. Compared with adding a damping orifice at the control oil port, no additional pilot circuit design is required, which is beneficial to the integration and miniaturization of the balance valve.

[0044] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A balancing valve, characterized in that, include: The valve body is provided with a main valve chamber, a control oil port, a load oil port and a working oil port. In the main valve chamber, a pilot valve core, a main valve core and an elastic element cavity are arranged in sequence along the axial direction. The pilot valve core and the main valve core are adapted to move along the axial direction of the main valve chamber to control the opening and closing of the oil passage from the load oil port to the working oil port. A valve sleeve adapted to abut against the main valve core to form a sealing structure, the valve sleeve and the main valve core having a shaft hole mating area, the valve sleeve and the main valve core in the shaft hole mating area being fitted with a shaft hole clearance, the shaft hole mating area being located between the sealing structure and the load port; A damping assembly is disposed within the cavity of the elastic element. The damping assembly includes a damping piston and a damping sleeve. The damping piston is connected to the main valve core and has a flow passage hole that communicates with the cavity of the elastic element and the cavity inside the damping piston. The damping piston is adapted to move in the opposite direction to the damping sleeve under the push of the main valve core to disconnect the flow passage hole from the cavity of the elastic element.

2. The balancing valve as described in claim 1, characterized in that, The damping piston and the damping sleeve are fitted with a shaft-hole clearance fit.

3. The balancing valve as described in claim 1, characterized in that, The width of the shaft hole mating area in the axial direction of the main valve cavity is greater than or equal to the diameter of the flow passage.

4. The balancing valve as described in claim 1, characterized in that, The main valve core has a tapered sealing surface, and the valve sleeve has an annular sealing surface. The tapered sealing surface and the annular sealing surface abut against each other to form the sealing structure.

5. The balancing valve as described in claim 1, characterized in that, Also includes: A pressure regulating screw is disposed at the bottom of the elastic element cavity; A first elastic element is disposed within the cavity of the elastic element. One end of the first elastic element is connected to the damping piston, and the other end of the first elastic element is connected to the pressure regulating screw.

6. The balancing valve as described in claim 1, characterized in that, It also includes a second elastic element, one end of which is connected to the valve sleeve.

7. The balancing valve as described in claim 1, characterized in that, The gap between the main valve chamber and the shaft hole of the main valve core forms a first channel, and the first channel connects the elastic element cavity and the working oil port.

8. The balancing valve as described in claim 1, characterized in that, It also includes a hydraulic control chamber, which is connected to the control oil port, and the pilot valve core is located in the hydraulic control chamber, forming a radial seal between the pilot valve core and the hydraulic control chamber.

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