A two-way damping valve for a hydraulic pilot control system

Abstract

The present invention discloses a two-way damping valve for a hydraulic pilot control system, belonging to the technical field of hydraulic valve pilot control. The two-way damping valve includes a plug valve sleeve, a one-way throttle valve spool and a throttle plug. A one-way throttle valve seat is installed in the plug valve sleeve; a valve seat throttle plug is installed in the one-way throttle valve seat; the one-way throttle valve spool is located inside the one-way throttle valve seat, and a spool throttle plug is installed in the one-way throttle valve spool. A spring is provided at the bottom of the spool throttle plug; its overall structure is simple and the volume is small, which is convenient for assembly in the hydraulic valve pilot control oil circuit. The oil of the two-way damping valve can flow from one oil port of the two-way damping valve to the other oil port, or can flow reversely. Different damping effects are generated in the two flow directions, solving the problems that the impact of the pilot oil is greatly changed during the pilot control of the existing construction machinery hydraulic valve and the reciprocating movement smoothness of the hydraulic valve spool is difficult to control.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic valve pilot control, and particularly relates to a two-way damping valve for a hydraulic pilot control system. Background Art

[0002] Hydraulic valves are important components of the hydraulic systems of construction machinery such as cranes, loaders, and aerial work platforms. They can control the performance of the entire equipment by the movement of the valve core to affect actuators such as cylinders and motors. At present, there are increasingly high requirements for the movement smoothness and use comfort of construction machinery products, and thus higher requirements are put forward for the movement smoothness of the hydraulic valve core of construction machinery.

[0003] Most existing construction machinery adopts a hydraulic system solution that uses a pilot oil circuit to control the hydraulic valve core of the main oil circuit. The reciprocating movement state of the hydraulic valve core of the main oil circuit determines the reciprocating movement state of actuators such as cylinders and motors of the entire equipment. However, the impact of the pilot oil flowing in both directions that drives the reciprocating movement of the hydraulic valve core of the main oil circuit may vary greatly, making it difficult to control the reciprocating movement smoothness of the hydraulic valve core of the main oil circuit, often resulting in poor reciprocating movement smoothness of the actuators of the main oil circuit, and further affecting the movement smoothness and use comfort of the entire equipment. At the same time, due to the requirements for the differences in speed and load when the actuators of the main oil circuit reciprocate in both directions, different smoothness requirements are imposed on the reciprocating movement of the hydraulic valve core of the main oil circuit in both directions. Therefore, by enhancing the stability of the pilot control oil flowing in both directions of the hydraulic valve core, the reciprocating movement smoothness of the hydraulic valve core of the main oil circuit can be effectively enhanced, and further the reciprocating movement smoothness of the actuators of the main oil circuit can be improved, while the reciprocating movement smoothness and use comfort of the entire equipment are improved.

[0004] As an important damping component in the hydraulic system, based on the principle of small hole throttling, the damping valve can reduce the oil flow rate and the oil pressure, effectively reduce the impact of the oil movement, enhance the smoothness of the oil movement, and thus the damping valve can be used in the hydraulic pilot control oil circuit of the hydraulic valve core to achieve the smoothness control of the movement of the hydraulic valve core. In order to enhance the stability of the pilot control oil flowing in both directions of the hydraulic valve core, a two-way damping valve can be used to achieve the stability control of the pilot control oil flowing in both directions and meet the different stability requirements of the pilot control oil flowing in both directions.

[0005] The "two-way damping valve structure" disclosed in the publication number: CN 204942128 U uses standard parts of symmetric left damping and right damping for the valve core. The adjustable range of the damping is small, the valve core has no spring control, it is difficult to meet the two-way adjustment requirements for the stability of oil flow, and the valve seat and the plug are of a separated structure and need to be installed in other threaded holes of the oil circuit to work properly, so the application range is small. The "two-way hydraulic damping valve" disclosed in the publication number: CN 107989846 A adopts a completely symmetric structure as a whole. The left and right oil inlet damping holes are located on the moving valve core. The damping adjustment range is small, and the structure of the moving valve core is complex, making it difficult to adjust the damping and it is difficult to meet different two-way adjustment requirements for the stability of oil flow. Summary of the Invention

[0006] Technical Problem: The purpose of the present invention is to overcome the deficiencies in the prior art and provide a two-way damping valve for a hydraulic pilot control system with a simple structure, small volume, convenient installation and good use effect.

[0007] Technical Solution: A two-way damping valve for a hydraulic pilot control system of the present invention includes a plug valve sleeve, a one-way throttle valve core and a throttle plug. A one-way throttle valve seat is installed in the plug valve sleeve; a valve seat throttle plug is installed in the one-way throttle valve seat; the one-way throttle valve core is located inside the one-way throttle valve seat, a valve core throttle plug is installed inside the one-way throttle valve core, and a spring is provided at the bottom of the valve core throttle plug; the valve seat throttle plug and the valve core throttle plug are connected in series to achieve two-way damping, and by changing the size of the damping hole, various two-way dampings can be achieved.

[0008] The plug valve sleeve is in a stepped shape that matches the hydraulic pilot control system. An oil port A is opened on the left side of the plug valve sleeve, and an oil port B is opened on the right side. The oil port A is a semi-threaded blind hole, and the oil port B is a through hole coaxially communicating with the oil port A; the outer ring at one end of the oil port A opened on the left side is hexagonal, and the outer ring at one end of the oil port B opened on the right side is externally threaded, and a combined gasket is provided at the shoulder.

[0009] One end of the one-way throttle valve seat is a full-threaded blind hole and is provided with an assembly slot, the other end is a cavity for accommodating the one-way throttle valve core, and the middle part is a through hole; the one-way throttle valve seat is connected to the plug valve sleeve through the outer ring thread, and an O-ring is provided between the one-way throttle valve seat and the plug valve sleeve.

[0010] One end of the valve seat throttle plug is provided with an assembly internal hexagonal groove, and the other end is provided with a damping hole communicating with the internal hexagonal groove. The valve seat throttle plug is threadedly connected to the one-way throttle valve seat.

[0011] One end of the spool of the one-way throttle valve is a conical surface with a through hole, the other end is a spring accommodation cavity, and the middle part is a full-thread blind hole; the assembly composed of the one-way throttle valve spool and the spool throttle plug is under the thrust of the spring, and the conical surface at one end of the one-way throttle valve spool fits with the one-way throttle valve seat.

[0012] One end of the spool throttle plug is provided with an assembled internal hexagonal groove, and the other end is provided with a damping hole. The spool throttle plug is threadedly connected to the one-way throttle valve spool.

[0013] Beneficial effects: Due to the adoption of the above technical solutions, the present invention is connected to the hydraulic valve pilot control oil circuit through two oil ports, and when the pilot control oil of the hydraulic valve spool flows in both forward and reverse directions in the two-way damping valve, the impact of the pilot control oil flowing in both forward and reverse directions is reduced, the smoothness of the reciprocating movement of the main oil circuit hydraulic valve spool is enhanced, the smoothness of the reciprocating movement of the main oil circuit actuator is improved, and further the smoothness of the reciprocating movement of the entire equipment and the use comfort are improved, solving the problems of large changes in the impact of the pilot oil during the pilot control of the existing construction machinery hydraulic valve, difficult control of the smoothness of the reciprocating movement of the hydraulic valve spool, and improvement of the smoothness of the actuator movement. The two-way damping valve structure that uses a fixed damping throttle plug in series with a one-way damping throttle plug has a simple overall structure and a small volume, which is convenient for assembly in the hydraulic valve pilot control oil circuit. The oil can flow from one oil port of the two-way damping valve to the other oil port, or it can flow in the reverse direction. Different damping effects are generated in the two flow directions, enhancing the stability of the pilot control oil flowing in both directions of the hydraulic valve spool, and further enhancing the smoothness of the reciprocating movement of the main oil circuit hydraulic valve spool, and meeting the requirements of different smoothness of the reciprocating movement of the main oil circuit hydraulic valve spool due to the differences in the speed and load of the reciprocating movement of the main oil circuit actuator in both directions, thereby effectively improving the smoothness of the reciprocating movement of the entire equipment and the use comfort. Description of the Drawings

[0014] Figure 1 It is a schematic diagram of the internal structure of the two-way damping valve for the hydraulic pilot control system of the present invention;

[0015] Figure 2 It is a three-dimensional structure schematic diagram of the two-way damping valve in the left viewing direction of the axonometric;

[0016] Figure 3 It is a three-dimensional structure schematic diagram of the two-way damping valve in the right viewing direction of the axonometric;

[0017] Figure 4 It is a schematic diagram of the internal structure of the one-way damping valve of the two-way damping valve of the present invention.

[0018] In the figure: 1 - plug valve sleeve; 2 - one-way throttle valve seat; 3 - throttle plug of valve seat; 4 - one-way throttle valve spool; 5 - throttle plug of spool; 6 - spring; 7 - O-ring seal; 8 - combined gasket. Detailed implementation mode

[0019] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

[0020] As Figures 1 - 3 shown, a two-way damping valve for a hydraulic pilot control system of the present invention mainly consists of a plug valve sleeve 1, a one-way throttle valve seat 2, a throttle plug of valve seat 3, a one-way throttle valve spool 4, and a throttle plug of spool 5; the one-way throttle valve seat 2 is installed in the plug valve sleeve 1; the throttle plug of valve seat 3 is installed in the one-way throttle valve seat 2; the one-way throttle valve spool 4 is located inside the one-way throttle valve seat 2, and a throttle plug of spool 5 is installed inside the one-way throttle valve spool 4, and a spring 6 is provided at the bottom of the throttle plug of spool 5; the throttle plug of valve seat 3 and the throttle plug of spool 5 are connected in series to achieve two-way damping, and by changing the size of the damping hole, various two-way damping can be achieved. The plug valve sleeve 1 is in a stepped shape that matches the hydraulic pilot control system. An oil port A is opened on the left side of the plug valve sleeve 1, and an oil port B is opened on the right side. The oil port A is a semi-threaded blind hole, and the oil port B is a through hole coaxially communicating with the oil port A; the outer ring of one end of the oil port A opened on the left side is hexagonal, and the outer ring of one end of the oil port B opened on the right side is externally threaded, and a combined gasket 8 is provided at the shoulder. One end of the one-way throttle valve seat 2 is a full-threaded blind hole and is provided with an assembly slot, the other end is a cavity for accommodating the one-way throttle valve spool 4, and the middle part is a through hole; the one-way throttle valve seat 2 is connected to the plug valve sleeve 1 through an outer ring thread, and the one-way throttle valve seat 2 and the plug valve sleeve 1 are sealed through an O-ring seal 7. One end of the throttle plug of valve seat 3 is provided with an assembly internal hexagonal groove, and the other end is provided with a damping hole communicating with the internal hexagonal groove. The throttle plug of valve seat 3 is threadedly connected to the one-way throttle valve seat 2. One end of the one-way throttle valve spool 4 is a conical surface and is provided with a through hole, the other end is a cavity for accommodating the spring 6, and the middle part is a full-threaded blind hole; the assembly formed by the one-way throttle valve spool 4 and the throttle plug of spool 5 is in contact with the one-way throttle valve seat 2 through the conical surface at one end of the one-way throttle valve spool 4 under the thrust of the spring 6. One end of the throttle plug of spool 5 is provided with an assembly internal hexagonal groove, and the other end is provided with a damping hole. The throttle plug of spool 5 is connected to the one-way throttle valve spool 4 through an outer ring thread. When the throttle plug of valve seat 3 is installed in the one-way throttle valve seat 2, the two-way damping valve realizes the two-way damping effect of the throttle plugs in series, and the two-way damping effects are different; both the throttle plug of valve seat 3 and the throttle plug of spool 5 can change the size of the damping hole to achieve various two-way damping effects;

[0021] Working principle: When the hydraulic pressure at oil port A is greater than the sum of the hydraulic pressure at oil port B and the spring force, the spool 4 of the one-way throttle valve disengages from the valve seat 2 of the one-way throttle valve and moves towards oil port B. The oil passage formed by the valve seat 2 of the one-way throttle valve and the spool 4 of the one-way throttle valve opens. At this time, the oil is only affected by the damping effect of the throttle plug 3 on the valve seat. When the sum of the hydraulic pressure at oil port B and the spring force is greater than the hydraulic pressure at oil port A, the spool 4 of the one-way throttle valve fits against the valve seat 2 of the one-way throttle valve, and the oil passage formed by the valve seat 2 of the one-way throttle valve and the spool 4 of the one-way throttle valve closes. At this time, the oil is affected by the combined damping effect of the throttle plug 5 on the spool and the throttle plug 3 on the valve seat. The oil in the two-way damping valve can flow from one oil port of the two-way damping valve to the other oil port, or it can flow in the reverse direction. The two flow directions produce different damping effects, which can solve the problems of large impact changes in the pilot oil and difficult control of the reciprocating movement stability of the hydraulic valve spool during the pilot control of the hydraulic valves of existing construction machinery.

[0022] As Figure 4 shown, after the throttle plug 3 on the valve seat is removed from the valve seat 2 of the one-way throttle valve, the two-way damping valve can achieve the one-way damping function. When the throttle plug 3 on the valve seat is removed from the valve seat 2 of the one-way throttle valve, during operation, when the hydraulic pressure at oil port A is greater than the sum of the hydraulic pressure at oil port B and the spring force, the spool 4 of the one-way throttle valve disengages from the valve seat 2 of the one-way throttle valve and moves towards oil port B. The oil passage formed by the valve seat 2 of the one-way throttle valve and the spool 4 of the one-way throttle valve opens. At this time, the oil is not affected by the damping effect of the throttle plug. When the sum of the hydraulic pressure at oil port B and the spring force is greater than the hydraulic pressure at oil port A, the spool 4 of the one-way throttle valve fits against the valve seat 2 of the one-way throttle valve, and the oil passage formed by the valve seat 2 of the one-way throttle valve and the spool 4 of the one-way throttle valve closes. At this time, the oil is only affected by the damping effect of the throttle plug 5 on the spool, that is, the one-way damping function.

[0023] In the above embodiments, both the throttle plug 3 on the valve seat and the throttle plug 5 on the spool can change the size of the damping hole to achieve the matching of various two-way damping sizes, expanding the application range of the two-way damping valve in the hydraulic pilot control system.

Claims

1. A two-way damping valve for a hydraulic pilot control system, comprising a plug valve sleeve (1), a one-way throttle valve spool (4) and a throttle plug, characterized in that: A one-way throttle valve seat (2) is installed in the plug valve sleeve (1); a valve seat throttle plug (3) is installed in the one-way throttle valve seat (2); the one-way throttle valve spool (4) is located inside the one-way throttle valve seat (2), a spool throttle plug (5) is installed in the one-way throttle valve spool (4), and a spring (6) is provided at the bottom of the spool throttle plug (5); the valve seat throttle plug (3) and the spool throttle plug (5) are connected in series to achieve two-way damping, and various two-way damping can be achieved by changing the size of the damping hole. The plug valve sleeve (1) is in a stepped shape that matches the hydraulic pilot control system. An oil port A is opened on the left side of the plug valve sleeve (1), and an oil port B is opened on the right side. The oil port A is a semi-threaded blind hole, and the oil port B is a through hole that is coaxially connected to the oil port A; the outer ring of one end of the oil port A opened on the left side is hexagonal, the outer ring of one end of the oil port B opened on the right side is externally threaded, and a combined gasket (8) is provided at the shoulder. One end of the one-way throttle valve seat (2) is a full-threaded blind hole and has an assembly slot, the other end is a cavity for accommodating the one-way throttle valve spool (4), and the middle part is a through hole; the one-way throttle valve seat (2) is connected to the plug valve sleeve (1) through the outer ring thread, and an O-ring (7) is provided between the one-way throttle valve seat (2) and the plug valve sleeve (1). One end of the one-way throttle valve spool (4) is a conical surface and has a through hole, the other end is a cavity for accommodating the spring (6), and the middle part is a full-threaded blind hole; the assembly body composed of the one-way throttle valve spool (4) and the spool throttle plug (5) is in contact with the one-way throttle valve seat (2) through the conical surface at one end of the one-way throttle valve spool (4) under the thrust of the spring (6).

2. The two-way damping valve for a hydraulic pilot control system according to claim 1, characterized in that: One end of the valve seat throttle plug (3) has an assembly internal hexagonal groove, and the other end has a damping hole that communicates with the internal hexagonal groove. The valve seat throttle plug (3) is threadedly connected to the one-way throttle valve seat (2).

3. The two-way damping valve for a hydraulic pilot control system according to claim 1, characterized in that: One end of the spool throttle plug (5) has an assembly internal hexagonal groove, and the other end has a damping hole. The spool throttle plug (5) is threadedly connected to the one-way throttle valve spool (4).

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