CN109026887B

CN109026887B - Buffer valve

Info

Publication number: CN109026887B
Application number: CN201811210743.6A
Authority: CN
Inventors: 不公告发明人
Original assignee: Heze Baite Engineering Machinery Co ltd
Current assignee: HEZE BAITE ENGINEERING MACHINERY Co.,Ltd.
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2020-05-19
Anticipated expiration: 2038-10-17
Also published as: CN109026887A

Abstract

The invention relates to a cushion valve, which comprises a valve body provided with a second oil port; a valve sleeve connected with the lower end of the valve body; the overflow valve core is arranged in the valve body in a sliding manner; the middle part of the buffering piston is in sliding fit in the valve sleeve and forms a buffering cavity with the valve sleeve, a first through-flow hole and a damping hole for communicating the first through-flow hole with the buffering cavity are arranged in the buffering piston, and a first oil port is formed by a lower port of the first through-flow hole; the screw sleeve is fixedly connected to the upper part of the valve sleeve; the adjusting rod is connected on the screw sleeve and forms a spring cavity with the overflow valve core; and the spring is arranged in the spring cavity. The buffer valve has the advantages of simple and reasonable structure, low processing and manufacturing cost, convenience in installation and good buffering effect.

Description

Buffer valve

Technical Field

The invention belongs to the technical field of hydraulic valves, and particularly relates to a buffer valve.

Background

In the slewing device of the existing mechanical equipment, a large number of hydraulic circuits with buffer functions are applied, such as an excavator slewing device, a crane slewing device, an overhead working truck slewing device, a manipulator slewing device, an agricultural and forestry mechanical slewing device and the like, wherein a buffer overflow valve is a key hydraulic element of the system, and the performance of the buffer overflow valve directly influences the performance of a main machine. The existing buffer overflow valve is divided into a plate-type buffer overflow valve and a plug-in type buffer overflow valve according to a connection mode, and the plug-in type buffer overflow valve is generally adopted in a system in order to reduce installation space and improve system reliability. If the grant publication number is "CN 202073860", the name is "thread-inserted adjustable buffer overflow valve", a buffer overflow valve is disclosed, which comprises a valve sleeve, a valve seat, a valve core, a spring and a buffer piston, wherein the valve sleeve is provided with a first oil port, the valve seat is arranged at the front end part of the valve sleeve and is provided with a second oil port, the valve core is arranged in the valve sleeve, a pressure regulating screw sleeve is provided with a front end inner cavity, the pressure regulating screw sleeve is arranged at the rear end part of the valve sleeve and can move axially so as to change the axial elasticity of the spring, the buffer piston comprises a guide part at the rear end, a convex ring part with a radial convex middle part and a cylinder accommodating part with an axial opening at the front end matched with the rear end part of the valve core, the rear end surface of the convex ring part is larger than the front end surface, a connecting channel for allowing oil to flow from the inner cavity of the cylinder to. Although the buffer overflow device can realize a simple buffer overflow function, the buffer overflow device has the advantages of more complex structure, larger volume, higher requirements in processing and assembly and high comprehensive cost; in addition, the first-stage pressure is set by adjusting the threaded sleeve, the pressure of the second oil port is quickly increased to the first-stage pressure to overflow, then the buffer piston compresses the spring to increase the pressure of the second port to the second-stage pressure, the damping hole is arranged on the plug at the front end of the valve core, the effect of controlling the buffer time is achieved when the first-stage pressure is converted to the second-stage pressure, but the response speed of the valve core is reduced due to the damping hole and the long length of the through-flow hole in the valve core, and the rotary valve is not ideal to be applied to equipment (such as a small excavator) which is frequently started and stopped in a rotary mode.

In summary, the existing buffer overflow valve can be further improved.

Disclosure of Invention

The invention aims to solve the technical problem of providing the cushion valve which can effectively cushion impact pressure, has simpler structure and more convenient processing, has shorter damping channel and can meet the working condition of frequent rotation.

The technical scheme adopted by the invention for solving the technical problems is as follows: a cushion valve, characterized by: the oil valve comprises a valve body with an axial through hole, wherein a second oil port is formed in the side wall of the lower part of the valve body; the valve sleeve is provided with a step-shaped through hole, and is in threaded connection with the lower end of the valve body; the overflow valve core is provided with an axial through hole and is arranged in the valve body and can slide up and down, and the lower port of the overflow valve core forms an overflow valve port; the middle part of the buffering piston is in sliding fit in the large-diameter part of the stepped through hole of the valve sleeve, the lower part of the buffering piston is in sliding fit in the small-diameter part of the stepped through hole of the valve sleeve and extends out of the lower part of the valve sleeve, the upper part of the buffering piston upwards extends into the valve body, a first through hole which axially penetrates through the buffering piston is arranged in the buffering piston, a first oil port is formed at the lower end port of the first through hole, a buffering cavity is formed between the lower end surface of the middle part of the buffering piston and the step surface of the inner hole of the valve sleeve, a damping hole which is used for communicating the first through hole with the buffering cavity is arranged on the side wall of the lower part of the buffering piston, and a sealing conical surface; the screw sleeve is connected to the upper end of the valve body in a threaded manner and used for sealing the upper opening of the valve body; the upper part of the adjusting rod is in threaded connection with an opening at the upper end of the threaded sleeve and extends upwards, the lower part of the adjusting rod is in sliding fit with an inner hole at the upper end of the valve body, a spring cavity is formed between the adjusting rod and the overflow valve core in the valve body, and a second through-flow hole for communicating the overflow valve port with the spring cavity is formed in the overflow valve core; and the spring is arranged in the spring cavity, one end of the spring is abutted against the adjusting rod, and the other end of the spring is abutted against the overflow valve core to enable the overflow valve core to keep a downward moving trend, so that the overflow valve port and the sealing conical surface are attached to separate the first oil port and the second oil port.

Preferably, the cushion valve further comprises a first spring seat and a second spring seat, the first spring seat is arranged between the upper end of the overflow valve core and the lower end of the spring, and the second spring seat is arranged between the lower end of the adjusting rod and the upper end of the spring.

The overflow valve core comprises a sliding section, a reducing section and an expanding section which are sequentially connected from top to bottom, the sliding section is in sliding fit with an inner hole of the valve body, and the cross-sectional area of the overflow valve port is larger than that of the sliding section.

The upper part of the adjusting rod is connected with a locking nut.

Compared with the prior art, the invention has the advantages that: this cushion valve simple structure, reasonable, manufacturing is convenient, with low costs, and simple to operate, cooperate through the overflow valve mouth that sets up buffer piston and overflow valve core, make buffer piston follow overflow valve core upward movement by initial position when the overflow valve core is opened until moving to the top position to make the spring compressed gradually, the pressure of first hydraulic fluid port rises to second overflow pressure by first overflow pressure gradually, and buffering effect is good. .

Drawings

FIG. 1 is a cross-sectional view of an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1, a preferred embodiment of the present invention.

A cushion valve comprises

The valve body 2 is provided with an axial through hole, and the side wall of the lower part of the valve body 2 is provided with a second oil port B.

And a valve sleeve 4 with a step-shaped through hole is in threaded connection with the lower end of the valve body 2.

The overflow valve core 3 with an axial through hole is arranged in the valve body 2 and can slide up and down, and the lower port of the overflow valve core 3 forms an overflow valve port 31. The overflow valve core 3 comprises a sliding section, a reducing section and an expanding section which are sequentially connected from top to bottom, the sliding section is in sliding fit with an inner hole of the valve body 2, and the cross-sectional area D1 of the overflow valve port 31 is larger than the cross-sectional area D2 of the sliding section.

The middle of the buffering piston 1 is in sliding fit in the large-diameter part of the stepped through hole of the valve sleeve 4, the lower part of the buffering piston 1 is in sliding fit in the small-diameter part of the stepped through hole of the valve sleeve 4 and extends to the lower part of the valve sleeve 4, the upper part of the buffering piston 1 extends upwards into the valve body 2, a first through-flow hole 102 which penetrates axially is formed in the buffering piston 1, a lower port of the first through-flow hole 102 forms a first oil port A, a buffering cavity 1a is formed between the lower end face of the middle of the buffering piston 1 and the stepped face of the inner hole of the valve sleeve 4, a damping hole 101 which is used for communicating the first through-flow hole 102 with the buffering cavity 1a is formed in the side wall of the lower part of the buffering piston 1, and a sealing conical surface 103 which is matched with the overflow valve.

And the threaded sleeve 7 is in threaded connection with the upper end of the valve body 2 and is used for sealing the upper opening of the valve body 2.

The upper portion of the adjusting rod 9 is in threaded connection with an opening at the upper end of the threaded sleeve 7 and extends upwards, the lower portion of the adjusting rod 9 is in sliding fit with an inner hole at the upper end of the valve body 2, a spring cavity 2a is formed between the adjusting rod 9 and the overflow valve core 3 in the valve body 2, and a second through hole 32 used for communicating the overflow valve port 31 with the spring cavity 2a is formed in the overflow valve core 3. The upper thread of the adjusting rod 9 is connected with a locking nut 8.

And the spring 5 is arranged in the spring cavity 2a, one end of the spring abuts against the adjusting rod 9, and the other end of the spring abuts against the overflow valve core 3 to enable the overflow valve core 3 to keep moving downwards, so that the overflow valve port 31 and the sealing conical surface 103 are attached to separate the first oil port A and the second oil port B.

A first spring seat 6a and a second spring seat 6b, the first spring seat 6a is arranged between the upper end of the overflow spool 3 and the lower end of the spring 5, and the second spring seat 6b is arranged between the lower end of the adjusting rod 9 and the upper end of the spring 5.

The working principle and the process of the buffer valve are as follows:

when the oil pump is used, the first oil port A and the second oil port B are respectively connected with two oil ports of a rotary motor.

When the slewing device normally revolves, the second oil port B is at high pressure, the first oil port A is in an oil return working condition, at the moment, under the pressure action of the second oil port B, the buffer piston 1 moves downwards to the lowest end, under the action of the spring 5, the overflow valve port 31 of the overflow valve core 3 is attached to the sealing conical surface 103 of the buffer piston 1, and the first oil port A and the second oil port B are isolated from each other.

When the slewing device is converted from normal slewing to a stop state, the reversing valve in the hydraulic system returns to a middle position, the oil supply to the second oil port B is stopped, and the first oil port A is also cut off by the reversing valve and is in a closed state; the rotating device is driven by the inertia effect of the load to rotate continuously, the pressure of the first oil port A rises, the second oil port B is in a low-pressure state, the pressure rising speed in the buffer cavity 1a lags behind the pressure rising speed of the first oil port A due to the delay effect of the damping hole 101, the pressure of the first oil port A acts on an annular area generated by the cross-sectional area D1 of the overflow valve port 31 and the cross-sectional area D2 of the sliding section of the overflow valve core 3 (D1-D2), when the pressure of the first oil port A rises to a first overflow pressure P1, the overflow valve core 3 overcomes the acting force of the spring 5 upwards to open the overflow valve port 31, the pressure oil of the first oil port A flows into the second oil port B through the overflow valve port 31 through the first through flow hole 102, and simultaneously the oil liquid of the first oil port A enters the buffer cavity 1a through the damping hole 101 to push the buffer piston 1a to move upwards to reduce the opening, therefore, because the opening degree of the overflow valve port 31 is reduced, the pressure of the first port a continues to rise, the overflow valve core 3 continues to move upwards to increase the opening degree of the overflow valve port 31, and the buffer piston 4 lags behind the upward movement to reduce the opening degree of the overflow valve port 31, so that the pressure of the first port a continues to rise again, according to the movement process, until the buffer piston 1 moves upwards to abut against the lower end face of the valve body 2, at this time, the buffer piston 1 cannot continue to move upwards, and the spring 5 generates greater compression from the initial position, at this time, the pressure of the first port a rises to the second overflow pressure P2, which is the maximum braking pressure of the slewing device, and the slewing device stops braking and slewing under the action of the second overflow pressure P2.

From above, when the slewer stopped the gyration, the pressure of first hydraulic fluid port A rose to second overflow pressure P2 by first overflow pressure P1 gradually, and the pressure rises peacefully, and no impact, buffering effect is good.

Claims

1. A cushion valve, characterized by: comprises that

The valve body (2) is provided with an axial through hole, and a second oil port (B) is formed in the side wall of the lower part of the valve body (2);

the valve sleeve (4) is provided with a step-shaped through hole and is in threaded connection with the lower end of the valve body (2);

the overflow valve core (3) is provided with an axial through hole, is arranged in the valve body (2) and can slide up and down, and the lower port of the overflow valve core (3) forms an overflow valve port (31); the overflow valve core (3) comprises a sliding section, a reducing section and an expanding section which are sequentially connected from top to bottom, the sliding section is in sliding fit with an inner hole of the valve body (2), and the cross sectional area (D1) of the overflow valve port (31) is larger than the cross sectional area (D2) of the sliding section;

the middle part of the buffering piston (1) is in sliding fit with the large-diameter part of the stepped through hole of the valve sleeve (4), the lower part of the buffering piston is in sliding fit with the small-diameter part of the stepped through hole of the valve sleeve (4) and extends to the lower part of the valve sleeve (4), the upper part of the buffering piston (1) upwards extends into the valve body (2), a first through-flow hole (102) which axially penetrates through the buffering piston (1) is formed in the buffering piston (1), a first oil port (A) is formed by a lower port of the first through-flow hole (102), a buffering cavity (1a) is formed between the lower end surface of the middle part of the buffering piston (1) and the step surface of the inner hole of the valve sleeve (4), a damping hole (101) for communicating the first through-flow hole (102) with the buffering cavity (1a) is formed in the side wall of the lower part of the buffering piston (1), and a sealing conical surface (103) which is matched with the overflow valve port (31) and used for controlling the connection and disconnection of;

the threaded sleeve (7) is in threaded connection with the upper end of the valve body (2) and is used for sealing the upper opening of the valve body (2);

the upper part of the adjusting rod (9) is in threaded connection with an opening at the upper end of the threaded sleeve (7) and extends upwards, the lower part of the adjusting rod (9) is in sliding fit with an inner hole at the upper end of the valve body (2), a spring cavity (2a) is formed between the adjusting rod (9) and the overflow valve core (3) in the valve body (2), and a second through hole (32) for communicating the overflow valve port (31) with the spring cavity (2a) is formed in the overflow valve core (3);

and the spring (5) is arranged in the spring cavity (2a), one end of the spring is abutted against the adjusting rod (9), the other end of the spring is abutted against the overflow valve core (3) to enable the overflow valve core (3) to keep the downward movement trend, and then the overflow valve port (31) is attached to the sealing conical surface (103) to separate the first oil port (A) and the second oil port (B).

2. A trim valve according to claim 1, wherein: still include first spring holder (6a) and second spring holder (6b), establish between overflow valve core (3) upper end and spring (5) lower extreme first spring holder (6a), establish between regulation pole (9) lower extreme and spring (5) upper end second spring holder (6 b).

3. A trim valve according to claim 1, wherein: the upper part of the adjusting rod (9) is connected with a locking nut (8).