CN108725414B

CN108725414B - A kind of braking pressure limiting valve

Info

Publication number: CN108725414B
Application number: CN201810510596.8A
Authority: CN
Inventors: 赵刚; 王俊伟; 冯海力; 蔡昌乐
Original assignee: Anhui Jianghuai Automobile Group Corp
Current assignee: Anhui Jianghuai Automobile Group Corp
Priority date: 2018-05-24
Filing date: 2018-05-24
Publication date: 2019-10-25
Anticipated expiration: 2038-05-24
Also published as: CN108725414A

Abstract

The invention discloses a kind of braking pressure limiting valves, including shell, air-out mechanism and air return mechanism；Shell have first opening, second opening and partition, partition by the inner cavity of shell be divided into the first chamber of the first opening in communication and with the second chamber of the second opening in communication, and partition be equipped with venthole and return-air hole；Air-out mechanism is intracavitary set on second, and air-out mechanism includes outlet closure member and outlet return unit, and outlet closure member is oppositely arranged with venthole；Air return mechanism is intracavitary set on first, and air return mechanism includes return-air closure member and return-air return unit, and return-air closure member is oppositely arranged with return-air hole.The braking pressure limiting valve of the disclosure flexibly effectively can easily balance the air pressure between gas source and the control device of braking system.

Description

Braking pressure limiting valve

Technical Field

The invention relates to an automobile brake system, in particular to a brake pressure limiting valve.

Background

The braking system mainly comprises an energy supply device, a control device, a transmission device, a brake and the like, and can decelerate or even stop a running automobile, keep the speed of the automobile running downhill stable and keep the stopped automobile still. The braking system can be divided into a mechanical braking system, a hydraulic braking system, a pneumatic braking system, an electromagnetic braking system and a combined braking system according to the braking energy transmission mode.

In the pneumatic power-assisted brake system, because the pressure of the air source is relatively high, the air of the air source needs to be prevented from directly entering a control device of the brake system, and the air of the air source is generally used after being depressurized by using a brake pressure limiting valve.

The existing brake pressure limiting valve has a housing formed by combining a plurality of sub-housings, and a gap is formed at the joint of each sub-housing. The gas entering the braking pressure-limiting valve is easy to discharge from the gaps, and external impurities can also enter the interior of the braking pressure-limiting valve through the gaps.

Therefore, how to avoid the air leakage of the braking pressure limiting valve and the external impurities entering the braking pressure limiting valve becomes a technical problem to be solved urgently in the field.

Disclosure of Invention

One object of the present invention is to provide a new technical solution for a braking pressure limiting valve that can effectively avoid air leakage and the entry of impurities.

According to an aspect of the present invention, a brake pressure limiting valve is provided.

The braking pressure limiting valve comprises a shell, an air outlet mechanism and an air return mechanism; wherein,

the shell is provided with a first opening, a second opening and a partition plate, the partition plate divides the inner cavity of the shell into a first cavity communicated with the first opening and a second cavity communicated with the second opening, and the partition plate is provided with an air outlet and an air return hole;

the air outlet mechanism is arranged in the second cavity and comprises an air outlet sealing piece and an air outlet resetting piece, the air outlet sealing piece is arranged opposite to the air outlet hole, and the air outlet resetting piece is arranged for applying force towards the partition plate to the air outlet sealing piece so that the air outlet sealing piece seals the air outlet hole;

the air return mechanism is arranged in the first cavity and comprises an air return sealing piece and an air return resetting piece, the air return sealing piece and the air return hole are arranged oppositely, and the air return resetting piece is arranged to apply force towards the partition plate to the air return sealing piece, so that the air return sealing piece seals the air return hole.

Optionally, the air outlet mechanism further comprises an air outlet mechanism bracket installed in the second cavity, and the air outlet reset piece is limited between the air outlet mechanism bracket and the air outlet closing piece;

the air return mechanism further comprises an air return mechanism support arranged in the first cavity, and the air return reset piece is limited between the air return mechanism support and the air return closing piece.

Optionally, the air outlet mechanism support and the air return mechanism support both have a cover-shaped structure;

the air outlet mechanism support is covered on the partition plate, covers the air outlet hole and the air return hole, and is provided with a first hole in the bottom wall;

the air return mechanism support covers the partition plate, the air outlet hole and the air return hole are covered by the air return mechanism support, and a second hole is formed in the bottom wall of the air return mechanism support.

Optionally, a gap is formed between the side wall of the air outlet mechanism support and the inner wall of the housing, and a third hole is formed in the side wall of the air outlet mechanism support;

a gap is formed between the side wall of the air return mechanism support and the inner wall of the shell, and a fourth hole is formed in the side wall of the air return mechanism support.

Optionally, an air outlet partition plate is arranged on the air outlet mechanism support, the air outlet partition plate extends from the bottom wall of the air outlet mechanism support towards the partition plate, the air outlet partition plate separates the air outlet hole and the air return hole, and a fifth hole is formed in the air outlet partition plate;

the air return mechanism is characterized in that an air return partition plate is arranged on the air return mechanism support, the air return partition plate faces towards the bottom wall of the air return mechanism support, the partition plate extends, the air outlet hole and the air return hole are separated by the air return partition plate, and a sixth hole is formed in the air return partition plate.

Optionally, the air outlet mechanism further comprises an air outlet mechanism bracket fixing piece for positioning the air outlet mechanism bracket in the second cavity;

the air return mechanism further comprises an air return mechanism bracket fixing piece used for positioning the air return mechanism bracket in the first cavity.

Optionally, the braking pressure limiting valve further comprises an air return control mechanism arranged in the first cavity, the air return control mechanism comprises an air return elastic member and an air return elastic adjusting member mounted on the air return mechanism support, and the air return elastic adjusting member is configured to adjust an elastic force provided by the air return elastic member to the air outlet sealing member toward the second opening; and/or

The braking pressure limiting valve further comprises an air outlet control mechanism arranged in the second cavity, the air outlet control mechanism comprises an air outlet elastic piece and an air outlet elastic adjusting piece arranged on the air outlet mechanism support, and the air outlet elastic adjusting piece is used for adjusting the elastic force provided by the air outlet elastic piece to the air return sealing piece towards the first opening.

Optionally, the air return control mechanism further comprises an air return elastic force transmission member, and the air return elastic force transmission member is arranged between the air return elastic member and the air outlet sealing member; and/or

The air outlet control mechanism further comprises an air outlet elastic force transmission piece, and the air outlet elastic force transmission piece is arranged between the air outlet elastic piece and the air return closing piece.

Optionally, the air-returning elastic force transmission piece comprises an air-returning baffle part and an air-returning contact part, the air-returning baffle part is in contact with the air-returning elastic piece, the air-returning baffle part covers the air outlet, the air-returning contact part is in clearance fit with the air outlet, and the air-returning contact part is in contact with the air outlet sealing piece; and/or

Go out gas elasticity transmission piece including the baffle portion of giving vent to anger and the contact site of giving vent to anger, give vent to anger the baffle portion with it contacts to give vent to anger the elasticity piece, just it covers to give vent to anger baffle portion the return air hole, give vent to anger the contact site with return air hole clearance fit, just give vent to anger the contact site with the return air closing piece contacts.

Optionally, the air return elasticity adjusting piece is in threaded fit connection with the air return mechanism support; and/or

The air outlet elasticity adjusting piece is in threaded fit connection with the air outlet mechanism support.

According to one embodiment of the present disclosure, when the sum of the pressure in the second chamber and the force exerted by the air outlet reset member on the air outlet closing member is less than the pressure in the first chamber, the air outlet is opened, and the first opening is communicated with the second opening through the air outlet to balance the air pressure of the first chamber and the air pressure of the second chamber; when the sum of the pressure in the first chamber and the force applied by the air return resetting piece to the air return closing piece is smaller than the pressure in the second chamber, the air return hole is opened, and the second opening is communicated with the first opening through the air return hole so as to balance the air pressure of the first chamber and the air pressure of the second chamber.

The braking pressure limiting valve disclosed by the invention can flexibly, effectively and conveniently balance air pressure between an air source and a control device of a braking system. The shell of the braking pressure-limiting valve is not provided with a gap, gas can only enter and exit from the first opening and the second opening of the braking pressure-limiting valve, the problem of gas leakage caused by the gap on the shell can not be caused, and impurities outside the braking pressure-limiting valve can not enter the interior of the braking pressure-limiting valve from the gap on the shell.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic structural diagram of an embodiment of a braking pressure limiting valve of the present invention.

The figures are labeled as follows:

a shell-1, a first opening-11, a second opening-12, a clapboard-13, an air outlet-131, an air return hole-132, a first cavity-14, a second cavity-15, an air outlet mechanism-2, an air outlet closing piece-21, an air outlet resetting piece-22, an air outlet mechanism bracket-23, a first hole-231, a third hole-232, an air outlet clapboard-233, a fifth hole-234, an air outlet mechanism bracket fixing piece-24, an air return mechanism-3, an air return closing piece-31, an air return resetting piece-32, an air return mechanism bracket-33, a second hole-331, a fourth hole-332, an air return clapboard-333, a sixth hole-334, an air return mechanism bracket fixing piece-34, an air return control mechanism-4 and an air return elastic piece-41, the air return elastic force adjusting part-42, the air return elastic force transmission part-43, the air return baffle part-431 and the air return contact part-432.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

The invention provides a brake pressure limiting valve, aiming at solving the problems of air leakage of the brake pressure limiting valve and the entering of external impurities into the brake pressure limiting valve.

As shown in fig. 1, the braking pressure limiting valve of the present disclosure includes a housing 1, an air outlet mechanism 2, and an air return mechanism 3. The housing 1 should be a one-piece housing, i.e. the housing 1 is not formed by a plurality of sub-housings, and there is no gap or clearance formed on the outer surface of the housing 1 due to the engagement of the plurality of sub-housings. The shape of the housing 1 may be, for example, a cylindrical shape, a rectangular block shape, or the like.

The housing 1 has a first opening 11, a second opening 12 and a partition 13. When the housing 1 has a cylindrical shape, the first opening 11 and the second opening 12 may be located on both bottom surfaces of the cylinder, respectively. The partition 13 may be formed by integral molding. The partition plate 13 divides the inner cavity of the housing 1 into a first chamber 14 communicating with the first opening 11 and a second chamber 15 communicating with the second opening 12, and the partition plate 13 is provided with an air outlet 131 and an air return hole 132. The first chamber 14 can be communicated with the second chamber 15 through the air outlet 131 or the air return hole 132, so that the first opening 11 is communicated with the second opening 12, and the ventilation function of the brake pressure-limiting valve is realized. Generally, the first opening 11 and the second opening 12 are disposed oppositely, and the air outlet 131 and the air return hole 132 correspond to the first opening 11 and the second opening 12 at the same time.

The air outlet mechanism 2 is arranged in the second cavity 15. The air outlet mechanism 2 includes an air outlet closing member 21 and an air outlet restoring member 22. The outlet closure 21 may function to close the outlet aperture 131. The outlet closure 21 is disposed opposite the outlet aperture 131. The air outlet reset piece 22 may apply a force to the air outlet closing piece 21 toward the partition plate 13 so that the air outlet closing piece 21 closes the air outlet hole 131. The structure of the outlet closure member 21 may be variously selected, for example, the outlet closure member 21 may have a block-like structure; for another example, the outlet closure member 21 may have a T-shaped structure, and the end surface of the T-shaped structure with a larger surface area in the length direction is opposite to the port of the outlet hole 131 in the second chamber 15. The air outlet reset member 22 may be, for example, a spring or a leaf spring or a slider or the like having a larger surface area than the air outlet closure member 21. The air outlet resetting member 22 may be fixed on the inner wall of the second cavity 15, for example, when the air outlet resetting member 22 is a spring, one end of the spring may be fixed on the inner wall of the second cavity 15 by integral molding or welding, and the other end of the spring may contact the air outlet sealing member 21 to provide an elastic force to the air outlet sealing member 21. The outlet reset member 22 may be further confined in the second chamber 15, for example, when the outlet reset member 22 is a compression spring, one end of the compression spring may abut against the surface of the outlet enclosure 21, and the other end of the compression spring may abut against a baffle plate extending outward from the surface of the inner wall of the second chamber 15, so as to provide an elastic force to the outlet enclosure 21, where the "outward" direction is a direction from the second chamber 15; for another example, when the gas outlet resetting member 22 is a slider having a larger surface area than the gas outlet closing member 21, the slider can be slidably engaged with the second chamber 15, one end of the slider is in contact with the gas outlet closing member 21, and the slider pushes the gas outlet closing member 21 to move when the gas entering the second chamber 15 from the second opening 12 pushes the slider to move along the second chamber 15.

The air return mechanism 3 is arranged in the first cavity 14. The air return mechanism 3 includes an air return closing member 31 and an air return returning member 32. The outlet closure 21 may function to close the outlet aperture 131. The return air closing member 31 is disposed opposite to the return air hole 132. The return air returning member 32 may apply a force to the return air closing member 31 toward the partition 13 so that the return air closing member 31 closes the return air hole 132. The structure of the return air closing member 31 may be variously selected, for example, the return air closing member 31 may have a block-like structure; for another example, the return air closing member 31 may have a T-shaped structure, and an end surface of the T-shaped structure, which has a large surface area in the longitudinal direction, is opposite to a port of the return air hole 132 in the first chamber 14. The return air reset 32 may be, for example, a spring or a leaf spring or a slide with a larger surface area than the return air closing member 31. The air return resetting member 32 may be fixed on the inner wall of the first cavity 14, for example, when the air return resetting member 32 is a spring, one end of the spring may be fixed on the inner wall of the first cavity 14 by integral molding or welding, and the other end of the spring may contact with the air return closing member 31 to provide an elastic force to the air return closing member 31. The return air element 32 may also be retained within the first chamber 14, for example, when the return air element 32 is a compression spring, one end of the compression spring may abut against a surface of the return air sealing member 31, and the other end of the compression spring may abut against a baffle extending outward from a surface of an inner wall of the first chamber 14, so as to provide an elastic force to the return air sealing member 31, where the "outward" direction is a direction from the first chamber 14; for another example, when the return air returning element 32 is a slider having a larger surface area than the return air closing element 31, the slider may be slidably engaged with the first chamber 14, one end of the slider being in contact with the return air closing element 31, and the slider pushes the return air closing element 31 to move when the gas entering the first chamber 14 from the first opening 11 pushes the slider to move along the first chamber 14.

In specific implementation, the air return mechanism 2 and the air outlet mechanism 3 may have the same structure, that is, the air outlet closing member 21 may have the same structure as the air return closing member 31, and the air outlet resetting member 22 may have the same structure as the air return resetting member 32, so as to more conveniently control the pressure limiting function of the brake pressure limiting valve.

When the brake pressure limiting valve is used, the first opening 11 is communicated with an air source, and the second opening 12 is communicated with a control device of a brake system.

When the sum of the pressure in the second chamber 15 and the force applied by the air outlet reset piece 22 to the air outlet closing piece 21 is smaller than the pressure in the first chamber 14, the air outlet 131 is opened, and at this time, the surface of the air return closing piece 31 closes the port of the air return hole 132 in the first chamber 14, so that the air return hole 132 is closed, and the first opening 11 is communicated with the second opening 12 through the air outlet 131. The gas from the gas source can enter the second chamber 15 through the first opening 11 and the gas outlet 131, the pressure at one end of the second opening 12 is continuously increased along with the inflow of the gas, the difference between the sum of the pressure in the second chamber 15 and the force applied by the gas outlet reset piece 22 to the gas outlet closing piece 21 and the pressure in the first chamber 14 is continuously reduced, and the gas outlet closing piece 21 is continuously close to the gas outlet 131. Until the sum of the pressure in the second chamber 15 and the force exerted by the outlet reset fitting 22 against the outlet closure member 21 equals the pressure in the first chamber 14, the outlet closure member 21 closes the outlet aperture 131 and the air pressure in the first chamber 14 and the air pressure in the second chamber 15 are balanced.

When the sum of the pressure in the first chamber 14 and the force applied by the return air returning element 32 to the return air closing element 31 is smaller than the pressure in the second chamber 15, the return air hole 132 is opened, and the surface of the outlet air closing element 21 closes the port of the outlet air hole 131 in the second chamber 15 so that the outlet air hole 131 is closed, and the second opening 12 is communicated with the first opening 11 through the return air hole 132. Gas from the control device of the brake system can enter the first chamber 14 through the second opening 12 and the return air hole 132, the pressure at one end of the first opening 11 is continuously increased along with the inflow of the gas, the difference between the sum of the pressure in the first chamber 14 and the force applied to the return air closing member 31 by the return air returning member 32 and the pressure in the second chamber 15 is continuously reduced, and the return air closing member 31 is continuously close to the return air hole 132. Until the sum of the pressure in the first chamber 14 and the force applied by the return air returning element 32 to the return air closing element 31 equals the pressure in the second chamber 15, the return air closing element 31 closes the return air hole 132 and the air pressure in the first chamber 14 and the air pressure in the second chamber 15 reach equilibrium.

When the sum of the pressure in the second cavity 15 of the brake pressure limiting valve and the force applied by the air outlet resetting piece 22 to the air outlet closing piece 21 is smaller than the pressure in the first cavity 14, the air outlet hole 131 is opened, and the first opening 11 is communicated with the second opening 12 through the air outlet hole 131 so as to balance the air pressure of the first cavity 14 and the air pressure of the second cavity 15; when the sum of the pressure in the first chamber 14 and the force applied by the return air returning member 32 to the return air closing member 31 is smaller than the pressure in the second chamber 15, the return air hole 132 is opened, and the second opening 12 communicates with the first opening 11 through the return air hole 132 to balance the air pressure of the first chamber 14 and the air pressure of the second chamber 15.

The braking pressure limiting valve disclosed by the invention can flexibly, effectively and conveniently balance air pressure between an air source and a control device of a braking system. The shell 1 of the braking pressure-limiting valve has no gap, gas can only enter and exit from the first opening 11 and the second opening 12 of the braking pressure-limiting valve, the problem of gas leakage caused by the gap on the shell 1 cannot be caused, and impurities outside the braking pressure-limiting valve cannot enter the interior of the braking pressure-limiting valve from the gap on the shell 1.

In one embodiment of the disclosed brake pressure limiting valve, the air outlet mechanism 2 further comprises an air outlet mechanism support 23 mounted in the second chamber 15. The outlet reset piece 22 is limited between the outlet mechanism support 23 and the outlet closing piece 21. The vent mechanism support 23 may function to retain the vent reset fitting 22 within the second chamber 15. The structure of the air outlet mechanism support 23 can be selected in various ways. For example, the air outlet mechanism support 23 may be a baffle plate fixed on the inner wall of the second cavity 15 by way of integral molding or welding, the air outlet reset piece 22 may be a spring abutting against the baffle plate or an elastic piece fixedly connected with the baffle plate, and the air outlet reset piece 22 is limited in the second cavity 15 by the baffle plate and the air outlet sealing piece 21. For another example, the exhaust mechanism support 23 may be an annular boss fixed on the inner wall of the second chamber 15 by integral molding or welding, the exhaust resetting member 22 may be a spring abutting against the annular boss, and the exhaust resetting member 22 is limited in the second chamber 15 by the annular boss and the exhaust sealing member 21.

The air return mechanism 3 further comprises an air return mechanism support 33 mounted in the first chamber 14. The return air resetting member 32 is confined between the return air mechanism bracket 33 and the return air closing member 31. The return air mechanism bracket 33 may function to retain the return air reset 32 within the first chamber 14. The structure of the air return mechanism support 33 can be variously selected. For example, the air return mechanism bracket 33 may be a baffle plate fixed on the inner wall of the first cavity 14 by means of integral molding or welding, the air return reset piece 32 may be a spring abutting against the baffle plate or an elastic sheet fixedly connected with the baffle plate, and the air return reset piece 32 is limited in the first cavity 14 by the baffle plate and the air return closing piece 31. For another example, the air return mechanism bracket 33 may be an annular boss fixed on the inner wall of the first cavity 14 by integral molding or welding, the air return reset element 32 may be a spring abutting against the annular boss, and the air return reset element 32 is limited in the first cavity 14 by the annular boss and the air return closing element 31.

The arrangement of the air outlet mechanism support 23 and the air return mechanism support 33 is beneficial to more conveniently assembling the braking pressure limiting valve, and the stability and the reliability of the structure of the braking pressure limiting valve are improved.

Further, the air outlet mechanism support 23 and the air return mechanism support 33 each have a lid-like structure. The cover-like structure is a structure having a bottom wall and side walls extending in the same direction from both ends of the bottom wall, and the cover-like structure may be covered or covered on a working surface, which is the surface of the partition 13 in this embodiment.

The air outlet mechanism support 23 covers the partition 13, and the air outlet mechanism support 23 covers the air outlet 131 and the air return hole 132. The bottom wall of the air outlet mechanism support 23 is provided with a first hole 231. The area defined by the surface of the partition plate 13 and the air outlet mechanism support 23 in the second chamber 15 and the area other than the area defined by the partition plate 13 and the air outlet mechanism support 23 in the second chamber 15 can be communicated through the first hole 231, and the gas entering from the second opening 12 can enter the return air hole 132 from the first hole 231. The number of the first holes 231 can be flexibly set according to actual requirements, for example, two first holes 231 opposite to the air outlet 131 and the air return hole 132 are arranged on the bottom wall of the air outlet mechanism support 23.

The air return mechanism bracket 33 is covered on the partition plate 13, and the air return mechanism bracket 33 covers the air outlet 131 and the air return hole 132. The bottom wall of the air return mechanism bracket 33 is provided with a second hole 331. The gas entering from the first opening 11 can enter the gas exit hole 131 from the second hole 331 through the second hole 331 communicating between the area of the first chamber 14 defined by the surface of the partition plate 13 and the air return mechanism support 33 and the area of the first chamber 14 other than the area of the partition plate 13 and the air return mechanism support 33. The number of the second holes 331 can be flexibly set according to actual requirements, for example, two second holes 331 are disposed on the bottom wall of the air return mechanism bracket 33 and are opposite to the air outlet 131 and the air return hole 132, respectively.

The air outlet mechanism support 23 and the air return mechanism support 33 with the cover-shaped structure can effectively support the air outlet reset piece 22 and the air return reset piece 32, and the assembly is convenient. In specific implementation, the air outlet mechanism support 23 and the air return mechanism support 33 may be fixed on the partition 13 by gluing or fixed on the inner wall of the housing 1 by welding.

Furthermore, a gap is formed between the sidewall of the air outlet mechanism support 23 and the inner wall of the housing 1, and a third hole 232 is formed in the sidewall of the air outlet mechanism support 23. A gap is formed between the side wall of the air outlet mechanism support 23 and the inner wall of the housing 1 to communicate with the second opening 12, and the third hole 232 communicates the gap with the area defined by the surface of the partition plate 13 and the air outlet mechanism support 23 in the second chamber 15. The number of the third holes 232 can be flexibly set according to actual requirements, for example, two opposite third holes 232 are arranged on the side wall of the air outlet mechanism support 23.

A gap is formed between the side wall of the air return mechanism support 33 and the inner wall of the housing 1, and a fourth hole 332 is formed in the side wall of the air return mechanism support 33. The side wall of the air return mechanism support 33 and the inner wall of the housing 1 have a gap therebetween that communicates with the first opening 11, and the fourth hole 332 communicates with the gap and the area defined by the surface of the partition plate 13 and the air return mechanism support 33 in the first chamber 14. The number of the fourth holes 332 can be flexibly set according to actual requirements, for example, two opposite fourth holes 332 are provided on the side wall of the air return mechanism bracket 33.

The provision of the third hole 232 facilitates more rapid equalization of the air pressure in the region defined by the surface of the partition plate 13 and the air outlet mechanism support 23 in the second chamber 15 and the region other than the region defined by the partition plate 13 and the air outlet mechanism support 23 in the second chamber 15. The provision of the fourth aperture 332 facilitates more rapid balancing of the area of the first chamber 14 defined by the surface of the partition 13 and the air return mechanism support 33 with the area of the first chamber 14 outside the area defined by the partition 13 and the air return mechanism support 33.

Further, an air outlet partition 233 is provided on the air outlet mechanism support 23. The air outlet partition 233 extends from the bottom wall of the air outlet mechanism support 23 toward the partition 13, and the air outlet partition 233 partitions the air outlet hole 131 and the air return hole 132. The free end of the air outlet partition 233 can abut against the surface of the partition 13, thereby dividing the area defined by the surface of the partition 13 and the air outlet mechanism support 23 into two sub air outlet areas in which the air outlet 131 and the air return hole 132 are respectively located. The outlet partition 233 is provided with a fifth hole 234. The fifth hole 234 may serve to communicate the two sub-venting regions. The number of the fifth holes 234 can be flexibly set according to actual requirements. In an embodiment of the braking pressure limiting valve, the air outlet partition 233 is provided with a fifth hole 234, and the sidewall of the air outlet mechanism support 23 is provided with two opposite third holes 232, and the fifth hole 234 and the two third holes 232 are correspondingly arranged.

The air return mechanism support 33 has an air return partition 333. The air-return partition 333 extends from the bottom wall of the air-return mechanism support 33 toward the partition 13, and the air-return partition 333 partitions the air outlet hole 131 and the air-return hole 132. The free end of the air return partition 333 may abut against the surface of the partition 13, thereby dividing the area defined by the surface of the partition 13 and the air return mechanism support 33 into two sub air return areas in which the air outlet hole 131 and the air return hole 132 are located, respectively. The air return partition 333 is provided with a sixth hole 334. The sixth hole 334 may serve to communicate the two sub-return air regions. The number of the sixth holes 334 can be flexibly set according to actual requirements. In an embodiment of the braking pressure limiting valve, the air return partition 333 is provided with a sixth hole 334, and the side wall of the air return mechanism support 33 is provided with two opposite fourth holes 332, and the sixth hole 334 and the two fourth holes 332 are correspondingly arranged.

The arrangement of the air outlet partition 233 and the air return partition 333 is advantageous for increasing the strength of the air outlet mechanism support 23 and the air return mechanism support 33, and more effectively supporting the air outlet mechanism support 23 and the air return mechanism support 33 on the partitions. The provision of the fifth hole 234 facilitates more rapid equalization of gas pressure between the two sub-venting regions. The provision of the sixth aperture 334 facilitates a more rapid equalisation of the air pressure between the two sub-return air regions.

Further, the air outlet mechanism 2 further includes an air outlet mechanism holder fixing member 24 for positioning the air outlet mechanism holder 23 in the second chamber 15. The air outlet mechanism bracket fixing part 24 may be, for example, a snap spring or a stopper. In specific implementation, a groove for fixing a clamp spring can be arranged on the inner wall of the second cavity 15, and the clamp spring abuts against the bottom wall of the air outlet mechanism support 23 to prevent the air outlet mechanism support 23 from coming off towards the second opening 12; alternatively, an elastic stopper may be disposed on the inner wall of the second cavity 15, and the stopper abuts against the bottom wall of the air outlet mechanism support 23 or the side wall of the air outlet mechanism support 23, so as to prevent the air outlet mechanism support 23 from coming off toward the second opening 12.

The air return mechanism 3 further includes an air return mechanism bracket fixing member 34 for positioning the air return mechanism bracket 33 in the first chamber 14. The air return mechanism bracket fixing member 34 may be, for example, a snap spring or a stopper. In specific implementation, a groove for fixing a clamp spring can be arranged on the inner wall of the first cavity 14, and the clamp spring abuts against the bottom wall of the air return mechanism support 33 so as to prevent the air return mechanism support 33 from coming off towards the first opening 11; alternatively, an elastic stopper may be disposed on the inner wall of the first cavity 14, and the stopper abuts against the bottom wall of the air return mechanism support 33 or the side wall of the air return mechanism support 33, so as to prevent the air return mechanism support 33 from coming off toward the first opening 11.

In one embodiment of the disclosed brake pressure limiting valve, the brake pressure limiting valve may further include a return air control mechanism 4 disposed within the first chamber 14. The return air control mechanism 4 includes a return air elastic member 41 and a return air elastic force adjusting member 42 mounted on the return air mechanism bracket 33. The air-return elasticity adjusting member 41 can adjust the elastic force provided by the air-return elasticity member 42 to the air outlet sealing member 21 toward the second opening 12. The return spring 41 may be a spring or a spring arm, for example. The return air elastic member 41 may be in direct contact with the surface of the outlet closure member 21 facing the outlet hole 131 or in indirect contact through an intermediate baffle to provide an elastic force to the outlet closure member 21. The air return elasticity adjusting member 42 can be mounted on the air return mechanism bracket 33 by means of screw-fitting or snap-fitting. When the air return elastic member 41 is a spring, the air return elastic member 41 can be limited between the air return elastic force adjusting member 42 and the air outlet sealing member 21; when the air-return elastic member 41 is an elastic arm, one end of the air-return elastic member 41 may be fixed to the air-return elastic adjustment member 42 by integral molding, welding, or bonding, and the other end of the air-return elastic member 41 may abut against the air outlet sealing member 21. In use, the return air elasticity adjusting member 42 changes the distance from the outlet sealing member 21 by moving relative to the return air mechanism support 33, thereby adjusting the elastic force provided by the return air elasticity adjusting member 42 to the outlet sealing member 21.

In this embodiment, when the sum of the pressure in the second chamber 15 and the force applied by the outlet reset member 22 to the outlet gas closing member 21 is greater than the sum of the pressure in the first chamber 14 and the elastic force applied by the return elastic member 42 to the outlet gas closing member 21, the surface of the outlet gas closing member 21 closes the port of the outlet hole 131 in the second chamber 15 so that the outlet hole 131 is closed. When the sum of the pressure in the first chamber 14 and the force applied by the return air returning member 32 to the return air closing member 31 is less than the pressure in the second chamber 15, the return air hole 132 is opened. The second opening 12 communicates with the first opening 11 via a return vent 132, and air from the control device of the brake system can enter the first chamber 14 via the second opening 12 and the return vent 132, so that the air pressure in the first chamber 14 and the air pressure in the second chamber 15 are balanced. By adjusting the distance between the air return elastic force adjusting piece 42 and the air outlet sealing piece 21, the elastic force provided by the air return elastic piece 42 to the air outlet sealing piece 21 is changed, so that the air return demand pressure of the brake pressure limiting valve is changed, and the function of adjusting the air return demand pressure is realized.

In one embodiment of the disclosed brake pressure limiting valve, the brake pressure limiting valve may further include an air outlet control mechanism (not shown) disposed within the second chamber 15. The air outlet control mechanism comprises an air outlet elastic piece and an air outlet elastic adjusting piece arranged on the air outlet mechanism bracket 23. The air outlet elastic adjustment member can adjust the elastic force provided by the air outlet elastic member to the air return sealing member 31 towards the first opening 11. The air outlet elastic member can be a spring or an elastic arm, for example. The air outlet elastic member may be in direct contact with a surface of the air return closing member 31 facing the air return hole 132 or in indirect contact through an intermediate baffle to provide an elastic force to the air return closing member 31. The air outlet elasticity adjusting piece can be arranged on the air outlet mechanism bracket 23 in a thread matching or clamping manner. When the air outlet elastic piece is a spring, the air outlet elastic piece can be limited between the air outlet elastic adjusting piece and the air return sealing piece 31; when the air outlet elastic member is an elastic arm, one end of the air outlet elastic member may be fixed to the air outlet elastic adjustment member by integral molding, welding, or bonding, and the other end of the air outlet elastic member may abut against the air return sealing member 31. In use, the outlet elasticity adjusting piece changes the distance between the outlet elasticity adjusting piece and the air return sealing piece 31 through moving relative to the outlet mechanism support 23, so that the elastic force provided by the outlet elasticity adjusting piece to the air return sealing piece 31 is adjusted.

In this embodiment, when the sum of the pressure in the first chamber 14 and the force applied to the return air closing member 31 by the return air returning member 32 is greater than the sum of the pressure in the second chamber 14 and the elastic force applied to the return air closing member 31 by the air outlet elastic member, the surface of the return air closing member 31 closes the port of the return air hole 132 in the first chamber 14 so that the return air hole 132 is closed. At this time, the pressure in the first chamber 14 is greater than the sum of the force applied to the discharge gas returning member 22 to the discharge gas closing member 21 and the pressure in the second chamber 15, and the discharge hole 131 is opened. The first opening 11 is in communication with the second opening 12 via the vent hole 131, and gas from a gas source can enter the second chamber 15 via the first opening 11 and the vent hole 131, so that the gas pressure of the first chamber 14 and the gas pressure of the second chamber 15 are balanced. By adjusting the distance between the air outlet elastic force adjusting piece and the air return sealing piece 31, the elastic force provided by the air outlet elastic piece to the air return sealing piece 31 is changed, so that the air outlet demand pressure of the braking pressure limiting valve is changed, and the function of adjusting the air outlet demand pressure is realized.

In one embodiment of the disclosed brake pressure limiting valve, the brake pressure limiting valve may include both the return air control mechanism 4 disposed within the first chamber 14 and the outlet air control mechanism disposed within the second chamber 15. The specific implementation of the air return control mechanism 4 and the air outlet control mechanism can refer to the above description of the air return control mechanism 4 and the air outlet control mechanism, which is not described in detail in this disclosure. As can be easily understood by those skilled in the art, by adjusting the distance between the air-return elastic force adjusting member 42 and the air-outlet sealing member 21 and/or the distance between the air-outlet elastic force adjusting member and the air-return sealing member 31, the elastic force provided by the air-return elastic member 42 to the air-outlet sealing member 21 and/or the elastic force provided by the air-outlet elastic member to the air-return sealing member 31 is changed, so that the air-return and/or air-outlet demand pressure of the brake pressure-limiting valve is changed, thereby achieving the function of adjusting the magnitude of the air-return and/or air-outlet demand pressure.

Further, the return air control mechanism 4 further includes a return air elastic force transmission member 42. The return air elasticity transmission member 42 is provided between the return air elasticity member 41 and the outlet closure member 21. The return spring force transmission member 42 can function to transmit the spring force of the return spring member 41 to the outlet closure member 21. The configuration of the return spring force transmission member 42 can be variously selected. For example, the return spring force transmission member 42 has a plate-like structure, and the return spring force member 41 and the outlet closing member 21 are respectively located on both surfaces of the return spring force transmission member 42. For another example, the return spring force transmission member 42 has a T-shaped structure, and an end surface of the T-shaped structure having a large surface area in the longitudinal direction is in contact with the return spring member 41, and the other end surface of the T-shaped structure in the longitudinal direction is in contact with the airtight packing 21. The arrangement of the return air elastic force transmission member 42 is beneficial to improving the smoothness of the elastic force transmission of the return air elastic member 41, so that the air outlet sealing member 21 moves more reliably.

Further, the air outlet control mechanism also comprises an air outlet elastic force transmission piece. The air outlet elastic force transmission piece is arranged between the air outlet elastic force transmission piece and the air return closing piece 31. The air outlet elastic force transmission member can play a role of transmitting the elastic force of the air outlet elastic member to the air return closing member 31. The structure of the outgoing spring force transmission member can be variously selected. For example, the outlet spring force transmission member has a plate-like structure, and the outlet spring force transmission member and the return air closing member 31 are respectively located on both surfaces of the outlet spring force transmission member. For another example, the air outlet elastic force transmission member has a T-shaped structure, and an end surface of the T-shaped structure having a large surface area in the longitudinal direction is in contact with the air outlet elastic member, and the other end surface of the T-shaped structure in the longitudinal direction is in contact with the air return seal member 31. The arrangement of the air outlet elastic force transmission piece is beneficial to improving the smoothness of the elastic force transmission of the air outlet elastic force transmission piece, so that the air return closing piece 31 can move more reliably.

In one embodiment of the disclosed brake pressure limiting valve, the brake pressure limiting valve may include both the return air control mechanism 4 disposed in the first chamber 14 and the outlet air control mechanism disposed in the second chamber 15, the return air control mechanism 4 including the return air elasticity transmission member 43, and the outlet air control mechanism including the outlet air elasticity transmission member. The specific implementation of the air return control mechanism 4 and the air outlet control mechanism can refer to the above description of the air return control mechanism 4 and the air outlet control mechanism, which is not described in detail in this disclosure.

Further, the return spring force transmission member 43 includes a return baffle portion 431 and a return contact portion 432. The return air baffle portion 431 is in contact with the return air elastic member 41, and the return air baffle portion 431 covers the air outlet hole 131. The fact that the air return flap portion 431 covers the air outlet 131 means that the size of the air return flap portion 431 is larger than that of the air outlet 131, so that the air return flap portion 431 is prevented from entering the air outlet 131. The air return contact portion 432 is in clearance fit with the air outlet 131, and the air return contact portion 432 is in contact with the air outlet sealing member 21. The return elastic force transmission member 432 of this structure can smoothly and efficiently transmit the elastic force of the return elastic member 41 to the outlet closure member 21.

Further, the air outlet elastic force transmission member includes an air outlet baffle portion and an air outlet contact portion. The air outlet baffle part is contacted with the air outlet elastic part, and the air outlet baffle part covers the air return hole 132. The air outlet baffle portion covers the air return holes 132, that is, the size of the air outlet baffle portion is larger than that of the air return holes 132, so that the air outlet baffle portion is prevented from entering the air return holes 132. The air outlet contact part is in clearance fit with the air return hole 132, and the air outlet contact part is in contact with the air return sealing piece 31. The air outlet elastic force transmission piece with the structure can smoothly and efficiently transmit the elastic force of the air outlet elastic force transmission piece to the air return closing piece 31.

Furthermore, the braking pressure limiting valve may include both the air return control mechanism 4 disposed in the first chamber 14 and the air outlet control mechanism disposed in the second chamber 15, the air return control mechanism 4 includes an air return elastic force transmission member 43, and the air return elastic force transmission member 43 includes an air return baffle portion 431 and an air return contact portion 432; the air outlet control mechanism comprises an air outlet elastic transmission piece, and the air outlet elastic transmission piece comprises an air outlet baffle part and an air outlet contact part. The specific implementation of the air return control mechanism 4 and the air outlet control mechanism can refer to the above description of the air return control mechanism 4 and the air outlet control mechanism, which is not described in detail in this disclosure.

Further, the return air elasticity adjusting member 42 is screw-fittingly connected to the return air mechanism bracket 33. In specific implementation, the return-air elasticity adjusting member 42 may include a screw, and a head and a baffle respectively located at two ends of the screw, the screw is in threaded fit with the screw hole on the return-air mechanism support 33, the head may be a hexagonal head, and the baffle abuts against an end of the return-air elasticity member 41. When the return air elasticity adjusting member 42 is screwed by the head portion of the return air elasticity adjusting member 42, the position of the return air elasticity adjusting member 42 in the return air mechanism bracket 33 is changed, so that the elastic force applied by the return air elasticity member 41 to the air closing member 21 is changed accordingly. The air return elasticity adjusting piece 42 with the structure has a simple structure, is easy to realize, and can conveniently realize the adjustment of the air return elasticity adjusting piece 42.

Further, the air outlet elasticity adjusting piece is in threaded fit connection with the air outlet mechanism support 23. During specific implementation, the air outlet elastic adjusting piece can comprise a screw rod, and a head and a baffle which are respectively positioned at two ends of the screw rod, the screw rod is in threaded fit with the screw hole in the air outlet mechanism support 23, the head can be a hexagonal head, and the baffle is abutted to the end of the air outlet elastic piece. When the outlet elasticity adjusting member is screwed by the head portion of the outlet elasticity adjusting member, the position of the outlet elasticity adjusting member on the outlet mechanism support 23 is changed, so that the elastic force applied by the outlet elasticity member to the return air sealing member 31 is changed accordingly. The air outlet elastic adjusting piece with the structure has a simple structure, is easy to realize, and can conveniently realize the adjustment of the air outlet elastic adjusting piece.

Further, the braking pressure limiting valve can simultaneously comprise an air return control mechanism 4 arranged in the first cavity 14 and an air outlet control mechanism arranged in the second cavity 15, the air return control mechanism 4 comprises an air return elastic adjusting piece 42, and the air return elastic adjusting piece 42 is in threaded fit connection with the air return mechanism support 33; the air outlet control mechanism comprises an air outlet elasticity adjusting piece, and the air outlet elasticity adjusting piece is in threaded fit connection with the air outlet mechanism support 23. The specific implementation of the air return control mechanism 4 and the air outlet control mechanism can refer to the above description of the air return control mechanism 4 and the air outlet control mechanism, which is not described in detail in this disclosure.

In order to more clearly illustrate the brake pressure limiting valve of the present disclosure, the following is illustrated by taking the embodiment shown in fig. 1 as an example:

as shown in the figures, the braking pressure limiting valve of the present disclosure includes a housing 1, an air outlet mechanism 2, an air return mechanism 3, and an air return control mechanism 4.

The housing 1 has a first opening 11, a second opening 12 and a partition 13. The partition plate 13 divides the inner cavity of the housing 1 into a first chamber 14 communicating with the first opening 11 and a second chamber 15 communicating with the second opening 12, and the partition plate 13 is provided with an air outlet 131 and an air return hole 132.

The air outlet mechanism 2 is arranged in the second cavity 15. The air outlet mechanism 2 comprises an air outlet sealing part 21, an air outlet resetting part 22, an air outlet mechanism bracket 23 and an air outlet mechanism bracket fixing part 24. The outlet closure member 21 has a T-shaped structure, and the end surface of the T-shaped structure with a large surface area in the length direction is opposite to the port of the outlet hole 131 in the second chamber 15. The air outlet reset 22 is a compression spring. The air outlet mechanism support 23 has a lid-like structure. The air outlet mechanism support 23 covers the partition 13, and the air outlet mechanism support 23 covers the air outlet 131 and the air return hole 132. An air outlet partition plate 233 is arranged on the air outlet mechanism support 23. The bottom wall of the air outlet mechanism support 23 is provided with two first holes 231 which are respectively opposite to the air outlet hole 131 and the air return hole 132. A gap is formed between the side wall of the air outlet mechanism support 23 and the inner wall of the housing 1, and two opposite third holes 232 are formed in the side wall of the air outlet mechanism support 23. The air outlet partition 233 extends from the bottom wall of the air outlet mechanism support 23 toward the partition 13, and the air outlet partition 233 partitions the air outlet hole 131 and the air return hole 132. One end of the vent resetting piece 22 abuts against the vent sealing piece 21, and the other end of the vent resetting piece 22 abuts against the surface of the region of the vent mechanism support 23 opposite to the vent hole 131, so that the vent resetting piece 22 is limited between the vent sealing piece 21 and the vent mechanism support 23. The air outlet partition plate 233 is provided with a fifth hole 234, and the fifth hole 234 and the two third holes 232 are correspondingly arranged. The air outlet mechanism support fixing piece 24 is a clamp spring, a groove for fixing the air outlet mechanism support fixing piece 24 is formed in the inner wall of the second cavity 15, and the air outlet mechanism support fixing piece 24 abuts against the bottom wall of the air outlet mechanism support 23 so as to fix the air outlet mechanism support 23 in the second cavity 15.

The air return mechanism 3 is arranged in the first cavity 14. The air return mechanism 3 includes an air return closing member 31, an air return returning member 32, an air return mechanism bracket 33, and an air return mechanism bracket fixing member 34. The return air closing member 31 has a T-shaped structure, and an end surface of the T-shaped structure having a large surface area in the longitudinal direction is opposed to a port of the return air hole 132 in the first chamber 14. Return air reset 32 is a compression spring. The air return mechanism bracket 33 has a lid-like structure. The air return mechanism bracket 33 is covered on the partition plate 13, and the air return mechanism bracket 33 covers the air outlet 131 and the air return hole 132. The air return mechanism support 33 is provided with an air return partition plate 333. The bottom wall of the air return mechanism support 33 is provided with a second hole 331 opposite to the air return hole 132. A gap is formed between the side wall of the air return mechanism support 33 and the inner wall of the housing 1, and two opposite fourth holes 332 are formed in the side wall of the air return mechanism support 33. The air-return partition 333 extends from the bottom wall of the air-return mechanism support 33 toward the partition 13, and the air-return partition 333 partitions the air outlet hole 131 and the air-return hole 132. One end of the air return returning piece 32 abuts against the air return closing piece 31, and the other end of the air return returning piece 32 abuts against the surface of the area of the air return mechanism bracket 33 opposite to the air return hole 132, so that the air return returning piece 32 is limited between the air return closing piece 31 and the air return mechanism bracket 33. The air return partition 333 is provided with a sixth hole 334, and the sixth hole 334 and the two fourth holes 332 are correspondingly arranged. The air return mechanism support fixing piece 34 is a clamp spring, a groove used for fixing the air return mechanism support fixing piece 34 is formed in the inner wall of the first cavity 14, and the air return mechanism support fixing piece 34 abuts against the bottom wall of the air return mechanism support 33 so as to fix the air return mechanism support 33 in the first cavity 14.

The return air control mechanism 4 includes a return air elastic member 41, a return air elastic force adjusting member 42, and a return air elastic force transmitting member 43. The return spring 41 is a compression spring. The return air elasticity adjusting part 42 comprises a screw rod, and a head part and a baffle plate which are respectively positioned at two ends of the screw rod, the screw rod is in threaded fit with a screw hole which is arranged on the return air mechanism support 33 and is opposite to the air outlet 131, the head part is a hexagonal head, and the baffle plate is abutted against the end part of the return air elasticity adjusting part 41. The return spring force transmission member 43 includes a return baffle portion 431 and a return contact portion 432. The return damper portion 431 covers the air outlet hole 131. The air return contact portion 432 is in clearance fit with the air outlet 131, and the air return contact portion 432 is in contact with the air outlet sealing member 21. One end of the return air spring 41 abuts against the flap of the return air spring adjuster 42, and the other end of the return air spring 41 abuts against the return air flap portion 431.

When the brake pressure limiting valve is used, the brake pressure limiting valve can comprise an air outlet state and an air return state.

When the sum of the pressure in the second chamber 15 and the force exerted by the air outlet resetting member 22 on the air outlet closing member 21 is smaller than the sum of the pressure in the first chamber 14 and the elastic force exerted by the air return elastic member 42 on the air outlet closing member 21, the air outlet 131 is opened, the surface of the air return closing member 31 closes the port of the air return hole 132 in the first chamber 14, so that the air return hole 132 is closed, and the first opening 11 is communicated with the second opening 12 through the air outlet 131. Gas from the gas source can enter the first chamber 14 through the first opening 11, then enter the area defined by the surface of the partition plate 13 and the return mechanism bracket 33 through the second hole 331, the fourth hole 332 and the sixth hole 334, and enter the second chamber 15 through the gas outlet hole 131, so that the brake pressure-limiting valve is in a gas outlet state.

The pressure at one end of the second opening 12 continuously increases along with the inflow of the gas, the difference between the sum of the pressure in the second chamber 15 and the force exerted by the gas outlet reset member 22 on the gas outlet closing member 21 and the sum of the pressure in the first chamber 14 and the elastic force exerted by the gas return elastic member 42 on the gas outlet closing member 21 continuously decreases, and the gas outlet closing member 21 continuously approaches the gas outlet hole 131. Until the sum of the pressure in the second chamber 15 and the force applied by the air outlet reset member 22 to the air outlet closing member 21 is equal to the sum of the pressure in the first chamber 14 and the elastic force applied by the air return elastic member 42 to the air outlet closing member 21, the air outlet closing member 21 closes the air outlet 131, and the air pressure in the first chamber 14 and the air pressure in the second chamber 15 reach equilibrium.

When the sum of the pressure in the first chamber 14 and the force applied by the return air resetting member 32 to the return air closing member 31 is smaller than the pressure in the second chamber 15, the return air hole 132 is opened, and at this time, the sum of the pressure in the second chamber 15 and the force applied by the outlet resetting member 22 to the outlet air closing member 21 is larger than the sum of the pressure in the first chamber 14 and the elastic force applied by the return air elastic member 42 to the outlet air closing member 21, the surface of the outlet air closing member 21 closes the port of the air outlet hole 131 in the second chamber 15 so that the air outlet hole 131 is closed, and the second opening 12 is communicated with the first opening 11 through the return air hole 132. Gas from the control device of the brake system can enter the second chamber 15 through the second opening 12, then enter the area defined by the surface of the partition plate 13 and the air outlet mechanism support 23 through the first hole 231, the third hole 232 and the fifth hole 234, and enter the first chamber 14 through the air return hole 132, so that the brake pressure-limiting valve is in an air return state.

The pressure at the end of the first opening 11 increases with the inflow of the gas, the difference between the sum of the pressure in the first chamber 14 and the force applied by the return air returning element 32 to the return air closing element 31 and the pressure in the second chamber 15 decreases, and the return air closing element 31 approaches the return air hole 132. Until the sum of the pressure in the first chamber 14 and the force applied by the return air returning element 32 to the return air closing element 31 equals the pressure in the second chamber 15, the return air closing element 31 closes the return air hole 132 and the air pressure in the first chamber 14 and the air pressure in the second chamber 15 reach equilibrium.

The air return elastic force adjusting piece 42 is screwed by the head of the air return elastic force adjusting piece 42, the position of the air return elastic force adjusting piece 42 on the air return mechanism support 33 is changed, the distance between the air return elastic force adjusting piece 42 and the air outlet sealing piece 21 is adjusted, the elastic force provided by the air return elastic piece 42 to the air outlet sealing piece 21 is changed, the air return requirement pressure of the brake pressure limiting valve is changed, and the function of adjusting the air return requirement pressure is achieved.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A braking pressure limiting valve is characterized by comprising a shell, an air outlet mechanism and an air return mechanism; wherein,

the air return mechanism is arranged in the first cavity and comprises an air return sealing piece and an air return resetting piece, the air return sealing piece is arranged opposite to the air return hole, and the air return resetting piece is arranged for applying force towards the partition plate to the air return sealing piece so that the air return sealing piece seals the air return hole;

the air outlet mechanism further comprises an air outlet mechanism bracket arranged in the second cavity, and the air outlet reset piece is limited between the air outlet mechanism bracket and the air outlet closing piece;

2. The brake pressure limiting valve according to claim 1, wherein the air outlet mechanism support and the air return mechanism support each have a cap-like structure;

3. The braking pressure limiting valve according to claim 2, wherein a gap is formed between the side wall of the air outlet mechanism support and the inner wall of the housing, and a third hole is formed in the side wall of the air outlet mechanism support;

4. The brake pressure limiting valve according to claim 2, wherein a vent partition plate is disposed on the vent mechanism support, the vent partition plate extends from a bottom wall of the vent mechanism support toward the partition plate, the vent partition plate separates the vent hole and the return vent, and a fifth hole is disposed on the vent partition plate;

5. The brake pressure limiting valve of claim 2 wherein said venting mechanism further comprises a venting mechanism support fixture for positioning said venting mechanism support within said second cavity;

6. The brake pressure limiting valve according to any one of claims 1 to 5, further comprising a return air control mechanism disposed in the first chamber, wherein the return air control mechanism comprises a return air elastic member and a return air elastic force adjusting member mounted on the return air mechanism support, and the return air elastic force adjusting member is configured to adjust an elastic force provided by the return air elastic member to the outlet closure member toward the second opening; and/or

7. The brake pressure limiting valve according to claim 6 wherein the return air control mechanism further comprises a return air spring force transmission member disposed between the return air spring member and the outlet closure member; and/or

8. The brake pressure limiting valve according to claim 7, wherein the return spring force transmission member comprises a return baffle portion and a return contact portion, the return baffle portion is in contact with the return spring member, the return baffle portion covers the air outlet hole, the return contact portion is in clearance fit with the air outlet hole, and the return contact portion is in contact with the air outlet sealing member; and/or

9. The brake pressure limiting valve according to claim 6, wherein the return air elasticity adjusting member is in threaded fit connection with the return air mechanism bracket; and/or