Pressure-reducing overflow valve

Abstract

The utility model belongs to the field of hydraulic valves, and particularly relates to a pressure reduction overflow valve which comprises a valve body, a valve sleeve, a guide sleeve, a main spring, a spring seat, a valve element and a push rod, a buffer cavity is formed between the valve element in the valve sleeve and the guide sleeve, and the buffer cavity communicates with a spring cavity through an oil passing gap between the push rod and the inner wall of the guide sleeve. The buffering cavity is communicated with the oil passing channel of the valve element through the damping hole, namely, a buffering area is additionally arranged between the spring cavity and the working oil port of the pressure reduction overflow valve, liquid is absorbed or discharged through the damping hole and the oil passing gap by means of oil, the damping effect of absorbing pressure fluctuation is achieved, therefore, oscillation and frequent switching of the valve element are reduced, and the service life of the pressure reduction overflow valve is prolonged. And abnormal sound and howling are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic valves, and in particular to a pressure reducing and relief valve. Background Art

[0002] A pressure reducing valve is a hydraulic valve that maintains a constant outlet pressure when the inlet pressure and outlet flow rate change. A three-way pressure reducing valve is commonly known as a pressure reducing relief valve, which can prevent the pressure at the pressure limiting port (working oil port) from rising above the set value through its relief function.

[0003] The pressure relief valve has a lot of pressure oscillations because the valve core is prone to overshoot when closing the oil inlet and immediately opens the overflow port. When the oil inlet pressure changes rapidly, overshoot is very likely to occur, causing the valve core to switch frequently and causing abnormal noise. Utility Model Content

[0004] The embodiment of the present application provides a pressure reducing relief valve, which aims to reduce valve core vibration and frequent switching, and avoid abnormal noise and howling.

[0005] To achieve the above-mentioned purpose, the present application provides a pressure reducing relief valve, including a valve body, a valve sleeve, a guide sleeve, a main spring, a spring seat, a valve core and a push rod;

[0006] The valve sleeve is arranged at one end of the valve body, an oil inlet and an overflow port are arranged on the valve sleeve at intervals along the axial direction, a working oil port is formed at one end of the valve sleeve away from the valve body, a spring cavity is arranged in the valve body and communicates with the interior of the valve sleeve, an oil outlet is arranged on the valve body to communicate the spring cavity with the outside, the guide sleeve is arranged at one end of the spring cavity close to the valve sleeve, the main spring and the spring seat are both located in the spring cavity, and the spring seat abuts against one end of the guide sleeve away from the valve sleeve under the action of the main spring;

[0007] The valve core is axially slidably arranged in the valve sleeve, one end of the push rod is connected to the valve core, and the other end slides through the guide sleeve and abuts against the spring seat, an oil gap is arranged between the push rod and the inner wall of the guide sleeve, a buffer cavity is formed in the valve sleeve between the valve core and the guide sleeve, an oil passage communicating with the working oil port is arranged in the valve core, a damping hole communicating with the oil passage and the buffer cavity is arranged on the valve core, an annular oil groove is circumferentially arranged on the outer wall of the valve core, a through hole communicating with the oil passage and the annular oil groove is arranged on the valve core, and the width of the annular oil groove is smaller than the distance between the oil inlet and the overflow port.

[0008] Optionally, a plurality of pressure equalizing grooves are arranged at intervals along the axial direction at a position where the push rod and the guide sleeve are in sliding contact.

[0009] Optionally, the pressure reducing relief valve further comprises an elastic reset assembly, which is disposed in the valve sleeve and acts on an end of the valve core away from the push rod, and the elastic force of the elastic reset assembly acting on the valve sleeve is smaller than the elastic force of the main spring.

[0010] Optionally, the elastic return assembly includes a retaining spring, a gasket and a return spring. An inner wall of the valve sleeve is circumferentially provided with an annular groove at one end close to the working oil port. The retaining spring is retained in the annular groove. The gasket is cushioned at one end of the retaining spring facing the valve core. The return spring is disposed between the gasket and the valve core, and two ends of the return spring are respectively against the gasket and the valve core. Under the action of the return spring, one end of the push rod away from the valve core is against the spring seat.

[0011] Optionally, the pressure reducing and relief valve also includes a pressure regulating assembly, and an installation port connected to the spring chamber is provided at one end of the valve body away from the valve sleeve. The pressure regulating assembly is arranged on the installation port and acts on one end of the main spring away from the spring seat, and the pressure regulating assembly is used to adjust the compression of the main spring.

[0012] Optionally, the pressure regulating assembly includes a mounting seat and an adjusting screw, the mounting seat is installed on the mounting port, the mounting seat is provided with a threaded hole connected to the spring cavity, the adjusting screw is passed through the threaded hole and threadedly connected to the threaded hole, and one end of the adjusting screw extending into the spring cavity abuts against an end of the main spring away from the spring seat.

[0013] Optionally, the pressure regulating assembly further includes a limiting nut, wherein the limiting nut is threadedly connected to one end of the adjusting screw located outside the threaded hole.

[0014] The beneficial effect of the pressure reducing relief valve provided by the present application is that compared with the prior art, the pressure reducing relief valve of the present application forms a buffer chamber between the valve core and the guide sleeve inside the valve sleeve, the buffer chamber and the spring chamber are connected through the oil gap between the push rod and the inner wall of the guide sleeve, and the buffer chamber and the oil passage of the valve core are connected through the damping hole, that is, the pressure reducing relief valve adds a buffer area between the spring chamber and the working oil port, and utilizes the oil to absorb or discharge liquid through the damping hole and the oil gap to achieve a damping effect of absorbing pressure fluctuations, thereby reducing valve core vibration and frequent switching, and avoiding abnormal noise and howling. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] in:

[0017] Figure 1 is a schematic cross-sectional structural diagram of a pressure reducing relief valve shown in one embodiment of the present application;

[0018] Figure 2 It is a partial cross-sectional structural schematic diagram of a pressure reducing relief valve in an overflow state shown in one embodiment of the present application.

[0019] Description of main component symbols:

[0020] 10. Valve body; 101. Spring chamber; 102. Oil outlet; 103. Installation port;

[0021] 20, valve sleeve; 201, oil inlet; 202, overflow port; 203, working oil port; 204, buffer chamber;

[0022] 30. Guide sleeve;

[0023] 40. Main spring;

[0024] 50. Spring seat;

[0025] 60, valve core; 601, oil passage; 602, annular oil groove; 603, through hole; 604, damping hole;

[0026] 70. Putting;

[0027] 80. elastic reset assembly; 81. retaining spring; 82. gasket; 83. reset spring;

[0028] 90. Pressure regulating assembly; 91. Mounting seat; 92. Adjusting screw; 93. Limiting nut;

[0029] 100. Oil clearance. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present application, the present application will be described more comprehensively with reference to the relevant drawings below. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many other different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] As described in the background technology, in the related technology, the pressure relief valve has a lot of pressure oscillations because the valve core is prone to overshoot when closing the oil inlet and immediately opens the overflow port. When the oil inlet pressure changes rapidly, overshoot is very likely to occur, resulting in frequent switching of the valve core and abnormal noise.

[0035] In order to solve the above problems, the embodiment of the present application provides a pressure reducing relief valve, such as Figure 1 and Figure 2As shown, the pressure reducing and relief valve comprises a valve body 10 , a valve sleeve 20 , a guide sleeve 30 , a main spring 40 , a spring seat 50 , a valve core 60 and a push rod 70 . The valve sleeve 20 is arranged at one end of the valve body 10, and an oil inlet 201 and an overflow port 202 are axially spaced apart on the valve sleeve 20. A working oil port 203 is formed at the end of the valve sleeve 20 away from the valve body 10. A spring chamber 101 communicating with the interior of the valve sleeve 20 is arranged in the valve body 10, and an oil outlet 102 connecting the spring chamber 101 with the outside is arranged on the valve body 10 (it can be understood here that the setting of the oil outlet 102 allows the oil entering the spring chamber 101 to be discharged, so as to avoid the accumulation of pressure oil in the spring chamber 101 causing the set pressure to increase, thereby affecting the pressure output by the working oil port 203). The guide sleeve 30 is arranged at one end of the spring chamber 101 close to the valve sleeve 20, and the main spring 40 and the spring seat 50 are both located in the spring chamber 101, and the spring seat 50 abuts against the end of the guide sleeve 30 away from the valve sleeve 20 under the action of the main spring 40. The valve core 60 is axially slidably arranged in the valve sleeve 20, one end of the push rod 70 is connected to the valve core 60, and the other end slides through the guide sleeve 30 and abuts against the spring seat 50. An oil gap 100 is arranged between the push rod 70 and the inner wall of the guide sleeve 30, and a buffer cavity 204 is formed in the valve sleeve 20 between the valve core 60 and the guide sleeve 30. An oil passage 601 communicating with the working oil port 203 is arranged in the valve core 60, and a damping hole 604 connecting the oil passage 601 and the buffer cavity 204 is arranged on the valve core 60. An annular oil groove 602 is arranged on the outer wall of the valve core 60 along the circumferential direction. The valve core 60 is provided with a through hole 603 connecting the oil passage 601 and the annular oil groove 602. The width of the annular oil groove 602 is smaller than the distance between the oil inlet 201 and the overflow port 202. It can be understood that when the annular oil groove 602 is connected with the oil inlet 201 correspondingly, the annular oil groove 602 and the overflow port 202 are completely staggered. The axial movement of the valve core 60 in the valve sleeve 20 can connect or disconnect the working oil port 203 and the oil inlet 201, or the axial movement of the valve core 60 in the valve sleeve 20 can connect or disconnect the working oil port 203 and the overflow port 202.

[0036] The working principle of the pressure relief valve is: when the oil inlet 201 on the valve sleeve 20 is connected to the annular oil groove 602 on the valve core 60 (such as Figure 1 The oil on the high-pressure oil circuit enters from the oil inlet 201, and enters the oil passage 601 through the annular oil groove 602 and the through hole 603 to provide oil for the working oil port 203. When the oil pressure on the working oil port 203 is too large, the oil will push the valve core 60 upward, and the valve core 60 drives the push rod 70 to overcome the elastic force of the main spring 40 and move upward, so that the annular oil groove 602 on the valve core 60 is staggered from the oil inlet 201, slowing down the entry of oil. When the annular oil groove 602 is completely staggered from the oil inlet 201, the annular oil groove 602 on the valve core 60 is connected to the overflow port 202 correspondingly (as shown in the state ... Figure 2The oil in the oil passage 601 flows out of the overflow port 202 through the through hole 603 and the annular oil groove 602, thereby reducing the oil pressure of the working oil port 203. After the oil pressure is reduced, under the action of the main spring 40, the push rod 70 and the valve core 60 move downward. At this time, the annular oil groove 602 is connected with the oil inlet 201, the working oil port 203 is isolated from the overflow port 202, and the working oil port 203 is connected with the oil inlet 201 to restart the pressure reducing function.

[0037] When the valve core 60 is impacted, the oil enters the buffer chamber 204 through the damping hole 604. During the upward movement of the valve core 60, the push rod 70 is driven to move upward, and the oil in the buffer chamber 204 enters the spring chamber 101 from the oil gap 100. Due to the damping effect of the oil gap 100, the oil inside the buffer chamber 204 cannot be discharged quickly, thereby slowing down the upward movement speed of the valve core 60 and improving the stability of the movement of the valve core 60; during the downward movement of the valve core 60, the elastic force of the main spring 40 pushes the push rod 70 to reset. At this time, the volume of the buffer chamber 204 becomes larger, and oil must be sucked from the oil inlet 201 and the spring chamber 101. The damping hole 604 and the oil gap 100 hinder the process of rapid oil absorption, thereby slowing down the downward movement speed of the valve core 60, reducing the impact of the valve core 60 action switching, and improving the stability of the valve core 60 action.

[0038] In the embodiment of the present application, a buffer chamber 204 is formed between the valve core 60 and the guide sleeve 30 inside the valve sleeve 20, the buffer chamber 204 is connected to the spring chamber 101 through the oil gap 100 between the push rod 70 and the inner wall of the guide sleeve 30, and the buffer chamber 204 is connected to the oil passage 601 of the valve core 60 through the damping hole 604, that is, the pressure reducing relief valve adds a buffer area between the spring chamber 101 and the working oil port 203, and utilizes the oil to absorb or discharge liquid through the damping hole 604 and the oil gap 100 to achieve a damping effect of absorbing pressure fluctuations, thereby reducing the oscillation and frequent switching of the valve core 60, and avoiding abnormal noise and howling.

[0039] In one embodiment, if Figure 1 As shown, a plurality of pressure equalizing grooves are arranged at intervals along the axial direction at the position where the push rod 70 and the guide sleeve 30 are in sliding contact.

[0040] According to the above arrangement, the plurality of pressure equalizing grooves are used to reduce the radial unbalanced force on the push rod 70 to prevent the push rod 70 from being stuck due to the radial unbalanced force. The specific number of the pressure equalizing grooves can be adjusted according to the actual working conditions.

[0041] In one embodiment, if Figure 1 and Figure 2As shown, the pressure reducing relief valve also includes an elastic reset assembly 80, which is arranged in the valve sleeve 20 and acts on the end of the valve core 60 away from the push rod 70. The elastic force of the elastic reset assembly 80 acting on the valve sleeve 20 is smaller than the elastic force of the main spring 40. The purpose of the elastic reset assembly 80 is only to help the valve core 60 reset.

[0042] In a specific embodiment, Figure 2 As shown, the elastic return assembly 80 includes a retaining spring 81, a gasket 82 and a return spring 83. An annular groove is circumferentially arranged on one end of the inner wall of the valve sleeve 20 close to the working oil port 203. The retaining spring 81 is clamped in the annular groove. The gasket 82 is cushioned on the end of the retaining spring 81 facing the valve core 60. The return spring 83 is arranged between the gasket 82 and the valve core 60, and the two ends of the return spring 83 are respectively against the gasket 82 and the valve core 60. Under the action of the return spring 83, the end of the push rod 70 away from the valve core 60 is against the spring seat 50.

[0043] In the default state, the return spring 83 pushes the valve core 60 and the push rod 70 upward. The force applied by the return spring 83 on the valve core 60 is much smaller than the force applied by the main spring 40 on the spring seat 50. The purpose of the return spring 83 is only to help the valve core 60 to reset.

[0044] In one embodiment, if Figure 1 As shown, the pressure reducing relief valve also includes a pressure regulating assembly 90 for adjusting the set pressure. An end of the valve body 10 away from the valve sleeve 20 is provided with a mounting port 103 connected to the spring chamber 101. The pressure regulating assembly 90 is arranged on the mounting port 103 and acts on an end of the main spring 40 away from the spring seat 50. The pressure regulating assembly 90 is used to adjust the compression amount of the main spring 40, thereby adjusting the oil pressure of the working oil port 203.

[0045] In a specific embodiment, continue to refer to Figure 1 The pressure regulating assembly 90 includes a mounting seat 91 and an adjusting screw 92. The mounting seat 91 is installed on the mounting port 103. The mounting seat 91 is provided with a threaded hole connected to the spring cavity 101. The adjusting screw 92 is passed through the threaded hole and screwed with the threaded hole. One end of the adjusting screw 92 extending into the spring cavity 101 abuts against the end of the main spring 40 away from the spring seat 50.

[0046] The pressure regulating assembly 90 is designed as above, with a simple structure and convenient adjustment. The compression amount of the main spring 40 can be adjusted by simply rotating the adjusting screw 92 to move it axially, thereby changing the force of the main spring 40 acting on the spring seat 50, and then adjusting the set pressure of the pressure reducing relief valve.

[0047] Furthermore, the pressure regulating assembly 90 also includes a limiting nut 93 , which is threadedly connected to one end of the adjusting screw 92 outside the threaded hole. The limiting nut 93 can fix the position of the adjusting screw 92 relative to the mounting seat 91 .

[0048] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A pressure reducing relief valve, characterized in that: It includes a valve body, a valve sleeve, a guide sleeve, a main spring, a spring seat, a valve core and a push rod; The valve sleeve is arranged at one end of the valve body, an oil inlet and an overflow port are arranged on the valve sleeve at intervals along the axial direction, a working oil port is formed at one end of the valve sleeve away from the valve body, a spring cavity is arranged in the valve body and communicates with the interior of the valve sleeve, an oil outlet is arranged on the valve body to communicate the spring cavity with the outside, the guide sleeve is arranged at one end of the spring cavity close to the valve sleeve, the main spring and the spring seat are both located in the spring cavity, and the spring seat abuts against one end of the guide sleeve away from the valve sleeve under the action of the main spring; The valve core is axially slidably arranged in the valve sleeve, one end of the push rod is connected to the valve core, and the other end slides through the guide sleeve and abuts against the spring seat, an oil gap is arranged between the push rod and the inner wall of the guide sleeve, a buffer cavity is formed in the valve sleeve between the valve core and the guide sleeve, an oil passage communicating with the working oil port is arranged in the valve core, a damping hole communicating with the oil passage and the buffer cavity is arranged on the valve core, an annular oil groove is circumferentially arranged on the outer wall of the valve core, a through hole communicating with the oil passage and the annular oil groove is arranged on the valve core, and the width of the annular oil groove is smaller than the distance between the oil inlet and the overflow port.

2. The pressure reducing relief valve according to claim 1, characterized in that: A plurality of pressure equalizing grooves are arranged at intervals along the axial direction at the position where the push rod and the guide sleeve are in sliding contact.

3. The pressure reducing relief valve according to claim 1, characterized in that: The pressure reducing relief valve also includes an elastic reset component, which is arranged in the valve sleeve and acts on one end of the valve core away from the push rod. The elastic force of the elastic reset component acting on the valve sleeve is smaller than the elastic force of the main spring.

4. The pressure reducing relief valve according to claim 3, characterized in that: The elastic return assembly includes a retaining spring, a gasket and a return spring. An inner wall of the valve sleeve is circumferentially provided with an annular groove at one end close to the working oil port. The retaining spring is retained in the annular groove. The gasket is cushioned at one end of the retaining spring facing the valve core. The return spring is disposed between the gasket and the valve core, and two ends of the return spring are respectively against the gasket and the valve core. Under the action of the return spring, one end of the push rod away from the valve core is against the spring seat.

5. The pressure reducing relief valve according to any one of claims 1 to 4, characterized in that: The pressure reducing and relief valve also includes a pressure regulating assembly. An installation port connected to the spring chamber is provided at one end of the valve body away from the valve sleeve. The pressure regulating assembly is arranged on the installation port and acts on one end of the main spring away from the spring seat. The pressure regulating assembly is used to adjust the compression amount of the main spring.

6. The pressure reducing relief valve according to claim 5, characterized in that: The pressure regulating assembly includes a mounting seat and an adjusting screw. The mounting seat is mounted on the mounting port. A threaded hole communicating with the spring cavity is provided on the mounting seat. The adjusting screw is passed through the threaded hole and threadedly connected with the threaded hole. One end of the adjusting screw extending into the spring cavity abuts against an end of the main spring away from the spring seat.

7. The pressure reducing relief valve according to claim 6, characterized in that: The pressure regulating assembly further comprises a limiting nut, and the limiting nut is threadedly connected to one end of the adjusting screw rod located outside the threaded hole.

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