Balancing valve pilot quick response structure

Abstract

The application provides a balanced valve pilot quick response structure and belongs to the technical field of balanced valves, and solves the problem of slow response speed in the prior art. The balanced valve pilot quick response structure comprises a main valve body and a pilot valve body, the main valve body is provided with a pilot cavity, the pilot valve body is provided with a first stepped cavity, a variable damping valve core is movably arranged in the first stepped cavity, an annular tapered surface is arranged on the variable damping valve core, a throttling groove is formed in the annular tapered surface, the variable damping valve core is connected with a reset mechanism, one end of the first stepped cavity with a smaller diameter is connected with a liquid inlet channel, one end of the first stepped cavity with a larger diameter is communicated with the pilot cavity through a hole, and the variable damping valve core is provided with a first damping. After the pressure of the liquid inlet channel is greater than the pressure of the pilot cavity by a certain value, the oil pushes the variable damping valve core to move, the oil enters one end of the first stepped cavity with a larger diameter through the throttling groove, and then flows into the pilot cavity, so that the rising speed of the pressure of the pilot cavity in the opening stage of the balanced valve is increased, and the response speed of the balanced valve is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of balance valve, and particularly to a balance valve pilot quick response structure. BACKGROUND

[0002] The pilot balance valve has the advantages of high rated working pressure, reliable closing, controllable flow, and small energy consumption, and is widely used in occasions where the working parts move vertically, such as excavating machinery, hoisting machinery, missile launching vehicles, and the like.

[0003] In order to reduce the overshoot and oscillation of the hydraulic system in which the pilot balance valve is located during operation, and improve the stability of the hydraulic system in which the pilot balance valve is located, a fixed damper is usually provided in the pilot oil circuit of the pilot balance valve. When the system exceeds the load mutation working condition, the balance valve needs to be opened by controlling the rapid rise of the pilot pressure, at this time, the control piston controlled by the pilot pressure needs to move quickly to respond, and in the existing structure, a fixed damper with a large damping value is provided in the pilot oil circuit to throttle, the pilot cavity pressure of the pilot balance valve rises slowly in the opening stage, causing the opening response time of the balance valve to be long. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide a balance valve pilot quick response structure, oil liquid first enters the pilot cavity through the first damper to push the control piston to move, after the pressure in the liquid inlet channel is greater than the pilot cavity pressure by a certain value, the oil liquid pushes the variable damper spool to move, the oil liquid enters the one end with larger diameter of the first step cavity through the throttling groove, and then flows into the pilot cavity, so as to realize the adjusting effect of variable damper, accelerate the rising speed of the pilot cavity pressure in the opening stage of the balance valve, accelerate the response speed when the balance valve opens, and improve the rapidity of the balance valve.

[0005] The technical scheme adopted by the present application is as follows:

[0006] A balance valve pilot quick response structure, comprising a main valve body and a pilot valve body connected with the main valve body, a pilot cavity is arranged in the main valve body, a control piston is movably sealed in the pilot cavity, a first step cavity is arranged in the pilot valve body, a variable damper spool is movably arranged in the first step cavity, an annular tapered surface is arranged on the outer wall of the variable damper spool, a throttling groove is formed in the annular tapered surface, the variable damper spool is connected with a reset mechanism for keeping the annular tapered surface abutting on the step of the first step cavity, one end with smaller diameter of the first step cavity is connected with a liquid inlet channel, one end with larger diameter of the first step cavity is communicated with the pilot cavity through a hole, a first damper is arranged in the variable damper spool, one end of the first damper is communicated with the liquid inlet channel, a first communication hole is formed in the variable damper spool, the first communication hole communicates the other end of the first damper with one end with larger diameter of the first step cavity.

[0007] Preferably, the reset mechanism comprises a first reset spring abutting against an end of the variable-damping spool.

[0008] Preferably, the reset mechanism further comprises a threaded stud extending into the pilot valve body and abutting against the first reset spring.

[0009] Preferably, a nut is threaded on the threaded stud, and a sealing gasket is movably sleeved on the threaded stud between the nut and the pilot valve body.

[0010] Preferably, an end face of the variable-damping spool is threaded with a plug.

[0011] Preferably, the pilot valve body is provided with a first mounting cavity in communication with the first stepped cavity and the pilot cavity, and the first mounting cavity is provided with a one-way valve assembly allowing oil to flow from the pilot cavity to the first mounting cavity.

[0012] Preferably, the one-way valve assembly comprises a valve sleeve mounted in the first mounting cavity, the valve sleeve is provided with a second stepped cavity in communication with the pilot cavity along the axial direction of the top rod, and an end of the second stepped cavity with a larger diameter movably provides a blocking ball.

[0013] Preferably, the second mounting cavity is in communication with a chamber where the reset mechanism is located.

[0014] Preferably, the second mounting cavity is provided with an opening in communication with the outer wall of the pilot valve body, and a sealing plug is threadedly connected to the opening.

[0015] Preferably, an end of the control piston away from the pilot valve body is connected with a control rod, and a spring assembly is sleeved on the control rod.

[0016] As described above, by adopting the technical scheme, the present application has the following advantages:

[0017] The oil first passes through the first damping to enter the pilot cavity to push the control piston to move, and when the pressure in the liquid inlet channel is greater than the pressure in the pilot cavity by a certain value, the oil pushes the variable-damping spool to move, and the oil enters the end of the first stepped cavity with a larger diameter through the throttle groove and then flows into the pilot cavity, thereby realizing the variable-damping adjustment effect, accelerating the rising speed of the pilot cavity pressure during the opening stage of the balance valve, accelerating the response speed during the opening of the balance valve, and improving the rapidity of the balance valve. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of the drawings.

[0019] Figure 1 The cross-sectional structure schematic diagram provided for the embodiments of the present application;

[0020] Figure 2 The schematic diagram of the ejector rod disengaging the blocking ball provided for the embodiments of the present application.

[0021] The drawings show: 1-main valve body; 2-pilot chamber; 3-control piston; 4-second installation chamber; 5-second damping; 6-sealing plug; 7-stud; 8-nut; 9-first return spring; 10-pilot valve body; 11-plug; 12-first communication hole; 13-variable damping spool; 14-annular tapered surface; 15-first damping; 16-throttle groove; 17-first step cavity; 18-first installation cavity; 19-valve sleeve; 20-second return spring; 21-blocking ball; 22-second communication hole; 23-second step cavity; 24-ejector rod; 25-liquid inlet channel; 26-spring group; 27-sealing gasket; 28-control rod. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] In the description of the present application, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0025] The application will be described below in conjunction with Figure 1 and Figure 2 The application will be described below in conjunction with

[0026] Embodiments

[0027] A balanced valve pilot quick response structure, comprising a main valve body 1 and a pilot valve body 10 connected with the main valve body 1, a pilot cavity 2 is arranged in the main valve body 1, a control piston 3 is movably sealed in the pilot cavity 2, a first stepped cavity 17 is arranged in the pilot valve body 10, a variable damping spool 13 is movably arranged in the first stepped cavity 17, an annular tapered surface 14 is arranged on the outer wall of the variable damping spool 13, a throttling groove 16 is arranged on the annular tapered surface 14, the variable damping spool 13 is connected with a reset mechanism for keeping the annular tapered surface 14 abutting on the step of the first stepped cavity 17, a liquid inlet channel 25 is connected with the end of the first stepped cavity 17 with smaller diameter, the end of the first stepped cavity 17 with larger diameter is communicated with the pilot cavity 2 through a hole, a first damping 15 is arranged in the variable damping spool 13, one end of the first damping 15 is communicated with the liquid inlet channel 25, a first communication hole 12 is arranged on the variable damping spool 13, the first communication hole 12 communicates the other end of the first damping 15 with the end of the first stepped cavity 17 with larger diameter. When the annular tapered surface 14 abuts on the first stepped cavity 17, the annular tapered surface 14 and the step of the first stepped cavity 17 form a sealing structure to avoid the flow of oil from this place.

[0028] The oil liquid from the liquid inlet channel 25 enters the lower end of the first stepped cavity 17 (i.e. the end with smaller diameter of the first stepped cavity 17), and the oil liquid first passes through the first damper 15 with fixed damping value, and then flows into the upper end of the first stepped cavity 17 (i.e. the end with larger diameter of the first stepped cavity 17) from the first communication hole 12, and the oil liquid enters the pilot cavity 2 through the hole and pushes the control piston 3 to move rightwards; in the opening stage of the balance valve, the pressure in the liquid inlet channel 25 rapidly rises, and when the oil liquid pressure in the liquid inlet channel 25 exceeds the oil liquid pressure in the pilot cavity 2 by a certain value, the resultant force of the pressure at the lower end of the variable damping spool 13 and the reset force of the reset mechanism is greater than the pressure at the upper end of the variable damping spool 13, so as to push the variable damping spool 13 to move upwards, the throttle groove 16 at the side of the variable damping spool 13 also moves upwards and is disengaged from the step of the first stepped cavity 17, the throttle groove 16 and the step of the first stepped cavity 17 form an oil outlet gap, the oil liquid flow channel other than the first damper 15 is increased, so as to reduce the damping value at the variable damping spool 13, further increase the oil liquid flow into the pilot cavity 2, accelerate the oil liquid pressure rising speed in the pilot cavity 2, and improve the opening speed of the balance valve.

[0029] When the oil liquid pressure in the liquid inlet channel 25 does not exceed the oil liquid pressure in the pilot cavity 2 by a certain value, the variable damping spool 13 is kept closed under the action of the reset mechanism, and the oil liquid in the liquid inlet channel 25 only flows into the pilot cavity 2 through the first damper 15, thereby ensuring the stability of the balance valve when the opening degree reaches the pilot setting value.

[0030] The reset mechanism comprises a first reset spring 9 abutting against the end of the variable damping spool 13. The first reset spring 9 is a compression spring arranged at the upper end of the variable damping spool 13 and abutting against the variable damping spool 13, so as to realize the automatic reset of the variable damping spool 13. The first reset spring 9 can also be replaced by a tension spring connected to the lower end of the variable damping spool 13, but in order to facilitate the installation of the first reset spring 9, the compression spring is preferred.

[0031] The reset mechanism further comprises a threaded stud 7 extending into the pilot valve body 10 and abutting against the first reset spring 9. The threaded stud 7 can adjust the pre-tightening force of the first reset spring 9, so as to select different reset forces for different working conditions, and meanwhile, the threaded stud 7 is convenient for dismounting the first reset spring 9.

[0032] A nut 8 is arranged on the threaded stud 7, and a sealing gasket 27 is movably sleeved on the threaded stud 7 and located between the nut 8 and the pilot valve body 10. The sealing gasket 27 seals the gap between the threaded stud 7 and the pilot valve body 10 under the pressure of the nut 8, so as to avoid the leakage of oil liquid.

[0033] As Figure 1As shown, one end surface of the variable damping spool 13 is threadedly provided with a plug 11. The plug 11 is arranged at one end of the variable damping spool 13 close to the first return spring 9. The variable damping spool 13 is hollow in structure. After the plug 11 is removed, the first damping 15 can be conveniently disassembled. The first damping 15 is threadedly connected to the variable damping spool 13.

[0034] The pilot valve body 10 is provided with a first mounting cavity 18 in communication with the first stepped cavity 17 at the end with a larger diameter and the pilot cavity 2. The first mounting cavity 18 is provided with a one-way valve assembly allowing oil to flow from the pilot cavity 2 to the first mounting cavity 18. The control piston 3 is connected with a top rod 24 for opening the one-way valve assembly. The pilot valve body 10 is provided with a second mounting cavity 4 in communication with the first mounting cavity 18 and the pilot cavity 2. The second mounting cavity 4 is provided with the second damping 5 at the connection with the first mounting cavity 18.

[0035] Under the action of the top rod 24, the one-way valve assembly remains in an open state (i.e. oil flows freely between the pilot cavity 2 and the first mounting cavity 18). Oil enters the pilot cavity 2 through the one-way valve assembly and the second damping 5. After the oil pushes the control piston 3 to move to the right, the top rod 24 is separated from the one-way valve assembly. At this time, the one-way valve assembly is closed, and oil can only enter the pilot cavity 2 from the second damping 5, so that the balance valve opening is further increased. At this time, the second damping 5 can keep the operation of the balance valve stable under the condition of large flow of oil. In the case of opening to closing of the balance valve, the pressure of the liquid inlet channel 25 is reduced, and the oil in the pilot cavity 2 pushes the one-way valve assembly to open. Finally, the oil flows out from the first damping 15.

[0036] The one-way valve assembly includes a valve sleeve 19 mounted in the first mounting cavity 18. The valve sleeve 19 is provided with a second stepped cavity 23 in communication with the pilot cavity 2 along the axial direction of the top rod 24. The second stepped cavity 23 is movably provided with a blocking ball 21 at the end with a larger diameter. The valve sleeve 19 is provided with a second return spring 20 for abutting the blocking ball 21 against the step of the second stepped cavity 23. The valve sleeve 19 is provided with a second communication hole 22 in communication with the second stepped cavity 23 and the first mounting cavity 18.

[0037] The blocking ball 21 can move in the valve sleeve 19. The second return spring 20 is arranged to abut the blocking ball 21 against the step of the second stepped cavity 23, so as to realize the closing of the one-way valve assembly. The top rod 24 is movably arranged in the axial direction of the valve sleeve 19 and extends into the second stepped cavity 23, so as to abut the blocking ball 21 to move in the direction of the second return spring 20. Oil enters the second stepped cavity 23 from the second communication hole 22 and flows into the pilot cavity 2 from the gap between the top rod 24 and the valve sleeve 19.

[0038] The second mounting cavity 4 is in communication with the chamber where the reset mechanism is arranged. The oil in the second mounting cavity 4 can enter the chamber where the reset mechanism is arranged to lubricate the related structure.

[0039] An opening is formed in the second installation cavity 4 and communicates with the outer wall of the pilot valve body 10, and a sealing plug 6 is threadedly and sealingly connected to the opening. The sealing plug 6 can facilitate the subsequent disassembly and assembly of the second damping 5, wherein the second damping 5 is threadedly connected to the pilot valve body 10.

[0040] The control piston 3 is connected to a control rod 28 at the end away from the pilot valve body 10, and the control rod 28 is sleeved with a spring set 26. The spring set 26 is composed of large and small springs to increase the rigidity of the spring set 26, so that the control piston 3 can be normally reset to the left.

[0041] By adopting the above technical scheme, the pilot valve can be quickly opened under the condition of load mutation, the pressure of the pilot cavity 2 connected with the control piston 3 rises rapidly when the pilot pressure rises rapidly, the control piston 3 controlled by the pilot pressure moves rapidly to respond, the response speed of the opening of the balance valve and the quick opening of the pilot valve under the condition of load mutation is increased, and the rapidity of the balance valve is improved.

[0042] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A balanced valve pilot quick response structure, comprising a main valve body (1) and a pilot valve body (10) connected with the main valve body (1), a pilot cavity (2) is arranged in the main valve body (1), a control piston (3) is movably sealed in the pilot cavity (2), characterized in that, The pilot valve body (10) is provided with a first stepped cavity (17), a variable damping valve core (13) is movably arranged in the first stepped cavity (17), an annular tapered surface (14) is arranged on the outer wall of the variable damping valve core (13), a throttling groove (16) is formed in the annular tapered surface (14), the variable damping valve core (13) is connected with a reset mechanism for keeping the annular tapered surface (14) abutting on the step of the first stepped cavity (17), one end of the first stepped cavity (17) with a smaller diameter is connected with a liquid inlet channel (25), the other end of the first stepped cavity (17) with a larger diameter is communicated with the pilot cavity (2) through a hole, a first damping (15) is arranged in the variable damping valve core (13), one end of the first damping (15) is communicated with the liquid inlet channel (25), a first communication hole (12) is formed in the variable damping valve core (13), the first communication hole (12) communicates the other end of the first damping (15) with the other end of the first stepped cavity (17) with a larger diameter; the pilot valve body (10) is provided with a first mounting cavity (18) communicated with the other end of the first stepped cavity (17) with a larger diameter and the pilot cavity (2), a one-way valve assembly allowing oil to flow from the pilot cavity (2) to the first mounting cavity (18) is arranged in the first mounting cavity (18), a top rod (24) for opening the one-way valve assembly is connected to the control piston (3), the pilot valve body (10) is provided with a second mounting cavity (4) communicated with the first mounting cavity (18) and the pilot cavity (2), a second damping (5) is arranged at the connection between the second mounting cavity (4) and the first mounting cavity (18); the second mounting cavity (4) is communicated with the chamber where the reset mechanism is located.

2. A pilot operated quick response structure for a balanced valve according to claim 1, characterized in that, The reset mechanism comprises a first reset spring (9) abutting on the end of the variable damping valve core (13).

3. A pilot operated quick response structure for a balanced valve according to claim 2, characterized in that, The reset mechanism further comprises a threaded stud (7) extending into the pilot valve body (10) and abutting with the first reset spring (9).

4. A pilot operated quick response structure for a balanced valve according to claim 3, characterized in that, A nut (8) is threadedly arranged on the threaded stud (7), and a sealing gasket (27) is movably arranged on the threaded stud (7) between the nut (8) and the pilot valve body (10).

5. The pilot operated quick response structure for a balanced valve according to claim 1, characterized by, A plug (11) is threadedly arranged on one end surface of the variable damping valve core (13).

6. A pilot operated quick response structure for a balanced valve according to claim 1, characterized in that, The one-way valve assembly comprises a valve sleeve (19) mounted in the first mounting cavity (18), the valve sleeve (19) is provided with a second stepped cavity (23) communicated with the pilot cavity (2) along the axial direction of the top rod (24), a blocking ball (21) is movably arranged at one end of the second stepped cavity (23) with a larger diameter, a second reset spring (20) is arranged in the valve sleeve (19) for abutting the blocking ball (21) on the step of the second stepped cavity (23), and a second communication hole (22) is formed in the valve sleeve (19) for communicating the second stepped cavity (23) and the first mounting cavity (18).

7. A pilot operated quick response structure for a balanced valve according to claim 1, characterized in that, An opening is formed in the second mounting cavity (4) and communicated with the outer wall of the pilot valve body (10), and a sealing plug (6) is threadedly and sealingly connected to the opening.

8. A pilot operated quick response structure for a balanced valve according to claim 1, characterized in that, A control rod (28) is connected to the end of the control piston (3) away from the pilot valve body (10), and a spring set (26) is sleeved on the control rod (28).

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