Pressure limiting valve

Abstract

The utility model discloses a pressure limiting valve which comprises a shell, an inner cavity is formed in the shell, and an air inlet and an air outlet which are communicated with the inner cavity are formed in the shell. A piston is arranged in the inner cavity, and one end of the piston is matched with the pressure regulating unit; a first valve seat is arranged on the side wall of the inner cavity, a first valve port is formed in the first valve seat, and the other end of the piston penetrates through the first valve port to abut against a first valve. A supporting spring is arranged at the end, away from the piston, of the first valve. According to the structure, the first valve port abuts against the first valve, gas supply and gas cutoff from the gas inlet to the gas outlet are achieved through cooperation of the first valve port and the first valve, in the process, friction force between a sealing ring at one end of the piston and the side wall does not need to be overcome, and the sealing mode of one end of the piston is changed, namely sliding sealing (sealing ring) is changed into contact sealing; the resistance is reduced, and the sensitivity is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure limiting valves, in particular to a pressure limiting valve. Background Art

[0002] The pressure limiting valve is used in vehicle air pressure pipelines or equipment units. It can limit the pipeline air pressure to ensure that the subsequent continuous components can work within the rated air pressure, prevent the air pressure from being too high, causing the connected components to work beyond the rated pressure, resulting in a reduction in component life or failure.

[0003] For example, Chinese patent document CN20628055U discloses a pressure limiting valve, which includes a valve body shell, an air inlet, an output port, an exhaust port, a first piston and a second piston. A first spring is arranged in the cavity of the first piston, and the lower end of the spring abuts against the top of the arched spring seat. A second spring is arranged in the second piston; a second valve port is arranged between the lower end of the second piston and the first piston, and a sealing ring is arranged at the lower end of the second piston to cooperate with the second valve port. When the pressure limiting function fails, the air pressure at the output port is higher than the preset pressure limiting pressure. When the pressure is higher than a certain value, the upward thrust of the second air pressure chamber on the second piston is greater than the upward thrust of the second spring on the second piston, the second piston moves upward, the second valve port opens, and part of the air pressure at the output port flows through the second valve port through the third air pressure chamber and is discharged from the exhaust port to the atmosphere. Although the above structure can achieve air replenishment through the first piston and the rubber sealing structure on the first piston, the sensitivity of air replenishment is still not very ideal. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a pressure limiting valve, including a shell, an inner cavity is arranged in the shell, and the shell has an air inlet and an air outlet connected with the inner cavity; a piston is arranged in the inner cavity, and one end of the piston cooperates with a pressure regulating unit; a first valve seat is arranged on the side wall of the inner cavity, a first valve port is formed on the first valve seat, and the other end of the piston passes through the first valve port and contacts with the first valve; a supporting spring is arranged at the end of the first valve away from the piston; the cooperation between the first valve and the first valve port realizes the supply and cut-off of air from the air inlet to the air outlet. In the above structure, the first valve port is used to contact with the first valve, and the supply and cut-off of air from the air inlet to the air outlet are realized through the cooperation between the two, and in the above process, there is no need to overcome the friction between the sealing ring at one end of the piston and the side wall, and the sealing method of one end of the piston is changed, that is, the sliding seal (sealing ring) is changed to a contact seal, which reduces the resistance and improves the sensitivity.

[0005] In one embodiment, a second valve is further included, and a second valve port is formed on the second valve, and the piston simultaneously passes through the second valve port and contacts the first valve; at this time, the second valve cooperates with the first valve port, and the first valve cooperates with the second valve port. In this scheme, through the double valve setting, the diameter of the second valve port is smaller than the diameter of the first valve port, which can effectively improve the air replenishment response. The air inlet can start to replenish air within a small range when the pressure change difference of the air outlet is within a small range, which improves the response efficiency of the limit valve. When the air outlet uses air, air can be replenished in time, which can avoid the problem of slow release of the handbrake and heavy clutch due to slow air replenishment.

[0006] In one embodiment, a pressure relief device is provided on the housing; a through hole is formed on the piston, one end of which cooperates with the first valve; and the other end of the through hole is connected to the pressure relief device. Through the above arrangement, when the pressure at the gas outlet exceeds the reference value, the piston will be lifted up, so that the end of the piston is separated from the first valve. At this time, the gas will flow along the gap between the second valve and the piston and the through hole, and then enter the pressure limiting device for pressure relief, thereby improving safety.

[0007] In one embodiment, the inner cavity side wall forms a limiting step, and the limiting step is used to limit the sliding of the piston.

[0008] In one embodiment, the second valve forms a limiting guide strip arranged around the piston. By forming the limiting guide strip, the movement of the second valve can maintain a predetermined track, reduce deviation, and ensure response sensitivity.

[0009] In one embodiment, there are multiple limiting guide strips, and air flow passages are formed between the multiple limiting guide strips.

[0010] In one embodiment, the pressure regulating unit includes a pressure regulating spring arranged in the inner cavity and a pressure regulating bolt arranged on the shell, and the pressure regulating bolt regulates the pressure of the pressure regulating spring through an upper pressure plate; the other end of the pressure regulating spring cooperates with the piston through a lower pressure plate; at the same time, an air hole is arranged on the lower pressure plate, and the air hole is connected with the through hole; the pressure relief device includes a breathing port formed on the shell and a dust-proof device arranged in the breathing port.

[0011] In one embodiment, a piston sealing ring is provided between the piston and the inner cavity wall; the first valve seat is fixed by a clamping ring, and a first valve seat sealing ring is provided between the first valve seat and the inner cavity wall.

[0012] In one embodiment, a support spring seat is disposed below the first valve seat, a vent hole is disposed on the support spring seat, and two ends of the support spring are respectively in contact with the first valve and the support spring seat.

[0013] In one embodiment, the air inlet and the air outlet are arranged on the same side.

[0014] The above-mentioned pressure limiting valve can be integrated with the pressure protection valve and the dryer, which is small in size, occupies little installation space and is easy to install. It can also be integrated with a multi-circuit protection valve (four-circuit or six-circuit). It can be made into a modular form to achieve a variety of layouts. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the specific implementation modes of the present invention, the following is a brief introduction to the drawings required for use in the specific implementation modes. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a structural schematic diagram of the pressure limiting valve of the utility model;

[0017] Figure 2 It is a structural schematic diagram of the second valve of the utility model;

[0018] Figure 3 yes Figure 1 A magnified view of middle;

[0019] Figure 4 It is a schematic diagram of the air intake structure of the pressure limiting valve of the utility model;

[0020] Figure 5 It is a schematic diagram of the structure of the air supply of the pressure limiting valve of the utility model;

[0021] Figure 6 It is a schematic diagram of the structure of the pressure relief of the pressure limiting valve of the utility model;

[0022] Figure 7 It is a structural schematic diagram of the air supply pressure of the pressure limiting valve of the utility model;

[0023] The reference numerals in the figure are represented as follows: 1-air inlet; 2-air outlet; 3-piston; 4-first valve seat; 5-first valve port; 6-first valve; 7-support spring; 8-second valve; 9-second valve port; 10-through hole; 11-limiting step; 12-limiting guide strip; 13-air flow passage; 14-pressure regulating spring; 15-pressure regulating spring; 16-upper pressure plate; 17-lower pressure plate; 18-air hole; 19-piston sealing ring; 20-clamp ring; 21-first valve seat sealing ring; 22-support spring seat; 23-vent; 24-breathing port; 25-dustproof device. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the contents of the utility model in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of the embodiments. The embodiments in the utility model and other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the utility model.

[0025] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Example 1

[0029] like Figure 1-3As shown, the present embodiment discloses a pressure-limiting valve, which includes a shell. The structure of the shell is not specifically limited and is preferably composed of multiple pieces. An inner cavity is arranged in the shell, and the inner cavity is used to arrange or install various components to form an air intake, an air replenishing channel and a pressure relief channel. An air inlet 1 and an air outlet 2 connected to the inner cavity are formed on the shell, and the air inlet 1 and the air outlet 2 are used to connect external components. A piston 3 is arranged in the inner cavity, and a sliding seal is formed between one end of the piston 3 or a position close to the end and the inner cavity wall. Specifically, a piston sealing ring 19 can be arranged between the piston 3 and the inner cavity wall to achieve this, such as a piston sealing ring is arranged on the piston 3 to achieve this. The end of the piston 3 close to the sliding sealing position cooperates with the pressure regulating unit. A first valve seat 4 is arranged on the side wall of the inner cavity. The first valve The seat 4 can be formed by the side wall of the inner cavity, or can be formed separately. In the present embodiment, it is preferably formed separately. At this time, the first valve seat 4 is fixed in the inner cavity by a clamping ring 20, and the clamping ring 20 is installed in a groove on the wall of the inner cavity. The first valve seat 4 is sealed with the inner cavity wall. Specifically, a first valve seat sealing ring 21 is arranged between the first valve seat 4 and the inner cavity wall. Preferably, the first valve seat sealing ring 21 is arranged in a groove on the side wall of the first valve seat 4; a first valve port 5 is formed on the first valve seat 4, and the other end of the piston 3 passes through the first valve port 5 and contacts the first valve 6. A supporting spring 7 is arranged at the end of the first valve 6 away from the piston 3, and the cooperation between the first valve 6 and the first valve port 5 realizes the air supply from the air inlet 1 to the air outlet 2. The structure of the first valve 6 is not specifically limited, and can be one structure or multiple structures. Of course, in order to achieve a better sealing effect, it at least includes a flexible pad structure that cooperates with the first valve port 5, such as a sheet, a ring, etc.; the circumference of the first valve 5 is preferably close to the inner cavity side wall of the first valve seat 4, and it is as close as possible to avoid deviation during operation; a support spring seat 22 is provided below the first valve seat 4, and the support spring seat 22 can be provided in various ways, such as being provided on the inner cavity side wall, or being provided on the first valve seat 4, such as Figure 3 As shown, the support spring seat 22 is buckled with the first valve seat 4; a vent hole 23 is provided on the support spring seat 22, and both ends of the support spring 7 are in contact with the first valve 6 and the support spring seat 22 respectively.

[0030] In one embodiment, a second valve 8 is further included, and a second valve port 9 is formed on the second valve 8. The piston 3 passes through the second valve port 9 and contacts the first valve 6 at the same time. At this time, the second valve 8 cooperates with the first valve port 5, and the first valve 6 cooperates with the second valve port 9, thereby forming a double valve structure. Compared with the single valve structure, the double valve structure has better sensitivity in replenishing air, as follows, refer to Figure 7 , the principle is as follows:

[0031] Assume that the air supply pressure difference is ΔP, that is, the air outlet drops by ΔP, and the air inlet starts to supply air to the air outlet;

[0032] Piston force during pressure limiting: S C *P 限 =F 弹簧 1)

[0033] Among them, S C is the area of ​​air pressure acting at the air outlet;

[0034] The pressure at the outlet drops ΔP, and the air inlet starts to supply air to the outlet:

[0035] F 弹簧 -S C *(P 限 -ΔP)=P 进 *S A 2)

[0036] Among them, S A is the contact area between the second valve port and the first valve;

[0037] Substituting formula 1) into formula 2), we get:

[0038] S C *ΔP=P 进 *S A , and then ΔP=P 进 *S A / S C , we can know from the formula: S C Increase or S A Reducing can reduce ΔP. In order to ensure the intake diameter, a valve is added to ensure intake ventilation, so that the air supply pressure difference of the double valve structure is smaller than that of the single valve structure, which improves the air supply sensitivity.

[0039] In one embodiment, a pressure relief device is provided on the housing; the piston forms a through hole 10, one end of the through hole 10 cooperates with the first valve 6, specifically, the first valve 6 closes and opens the end of the through hole 10 to achieve a pressure relief function, and the other end of the through hole 10 is connected to the pressure relief device. As for the pressure relief device, there is no specific limitation. In this embodiment, the pressure relief device includes a breathing port 24 formed on the housing and a dust prevention device 25 arranged in the breathing port 24, and the breathing port 24 runs through the housing.

[0040] In one embodiment, a limiting step 11 is formed on the side wall of the inner cavity, and the limiting step is used to limit the sliding of the piston 3.

[0041] In one embodiment, the second valve 8 is formed with a limiting guide strip 12 arranged along the periphery of the piston, and there are a plurality of limiting guide strips 12 , and an air flow channel 13 is formed between the plurality of limiting guide strips 12 .

[0042] In one embodiment, the pressure regulating unit includes a pressure regulating spring 14 arranged in the inner cavity and a pressure regulating bolt 15 arranged on the shell. The pressure regulating bolt 15 regulates the pressure of the pressure regulating spring 14 through an upper pressure plate 16, and the other end of the pressure regulating spring 14 cooperates with the piston 3 through a lower pressure plate 17.

[0043] In one embodiment, the lower pressing plate 17 is provided with an air hole 18 , and the air hole 18 is connected to the through hole 10 . Specifically, the lower pressing plate 17 is fitted with the end of the piston 3 , so that the air hole 18 is located above the through hole 10 .

[0044] The pressure limiting valve of the utility model can be used for an integrated dryer. When the gas consumption in the circuits 23 and 24 is frequent and large, the circuits 23 and 24 are replenished with gas. When the gas pressure in the circuits 23 and 24 is relatively high, the pressure is released through the pressure relief structure of the pressure limiting valve.

[0045] The use process of the pressure limiting valve of the utility model is as follows:

[0046] 1. Intake process (reference Figure 4 ): Gas enters the air outlet through the air inlet, the air vent, the gaps between the first valve and the second valve and the first valve seat, the gap between the first valve and the second valve, the gap between the second valve and the piston, the gap between the piston and the first valve seat, and the space between the piston above the first valve seat and the shell.

[0047] 2. Qi replenishment process (reference Figure 5): When the air pressure at the air outlet reaches a certain level, the piston is pushed upward, the first valve closes the second valve port and the through hole, and the second valve closes the first valve port to stop air intake. When the air pressure at the air outlet drops, the piston moves downward, preferentially pushing the first valve downward, so that there is a gap between the first valve and the second valve port, and air is quickly replenished; when the air pressure at the air outlet drops significantly, the piston moves downward with a large amplitude, and at this time, the space between the second valve and the first valve port is also opened to replenish air.

[0048] 3. Pressure relief process (reference Figure 6 ): When the air pressure at the air outlet is greater than the set value, the piston is pushed upward so that a gap exists between the lower end of the piston and the first valve. At this time, the gas is depressurized along the gap between the piston and the first valve seat, the air flow channel, the gap between the piston and the second valve, the lower end of the through hole and the entire through hole, the air hole, the space above the piston, and the pressure relief device to ensure the safety of gas use.

[0049] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A pressure limiting valve, characterized in that: It comprises a shell, an inner cavity is arranged in the shell, and an air inlet and an air outlet connected with the inner cavity are provided on the shell; a piston is arranged in the inner cavity, and one end of the piston cooperates with a pressure regulating unit; a first valve seat is arranged on the side wall of the inner cavity, a first valve port is formed on the first valve seat, and the other end of the piston passes through the first valve port and contacts with a first valve; a supporting spring is arranged at the end of the first valve away from the piston; the cooperation between the first valve and the first valve port realizes the air supply and air cut-off from the air inlet to the air outlet.

2. The pressure limiting valve according to claim 1, characterized in that: It also includes a second valve, on which a second valve port is formed, and the piston simultaneously passes through the second valve port and conflicts with the first valve; at this time, the second valve cooperates with the first valve port, and the first valve cooperates with the second valve port.

3. The pressure limiting valve according to claim 1 or 2, characterized in that: The housing is provided with a pressure relief device; the piston forms a through hole, one end of the through hole cooperates with the first valve; the other end of the through hole is connected to the pressure relief device.

4. The pressure limiting valve according to claim 3, characterized in that: The inner cavity side wall forms a limiting step, and the limiting step is used to limit the sliding of the piston.

5. The pressure limiting valve according to claim 2, characterized in that: The second valve forms a limiting guide strip arranged along the periphery of the piston.

6. The pressure limiting valve according to claim 5, characterized in that: There are multiple limiting guide strips, and airflow passages are formed between the multiple limiting guide strips.

7. The pressure limiting valve according to claim 3, characterized in that: The pressure regulating unit includes a pressure regulating spring arranged in the inner cavity and a pressure regulating bolt arranged on the shell, and the pressure regulating bolt regulates the pressure of the pressure regulating spring through an upper pressure plate; the other end of the pressure regulating spring cooperates with the piston through a lower pressure plate; at the same time, an air hole is arranged on the lower pressure plate, and the air hole is connected with the through hole; the pressure relief device includes a breathing port formed on the shell and a dustproof device arranged in the breathing port.

8. The pressure limiting valve according to claim 1 or 2, characterized in that: A piston sealing ring is arranged between the piston and the inner cavity wall; the first valve seat is fixed by a clamping ring, and a first valve seat sealing ring is arranged between the first valve seat and the inner cavity wall.

9. The pressure limiting valve according to claim 8, characterized in that: A support spring seat is arranged below the first valve seat, a vent hole is arranged on the support spring seat, and two ends of the support spring are respectively in contact with the first valve and the support spring seat.

10. The pressure limiting valve according to claim 1 or 2, characterized in that: The air inlet and the air outlet are arranged on the same side.

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