Foot brake valve

Abstract

The utility model provides a foot brake valve. The foot brake valve comprises a valve body, a pushing element, an upper piston capable of moving downwards under driving of the pushing element, a first valve capable of being opened under driving of the upper piston, a middle piston capable of moving downwards and a second valve capable of being opened under driving of the middle piston are sequentially arranged in the valve body from top to bottom, and the upper piston comprises a circumferential wall. The foot brake valve further comprises a spacer bush element and a sealing element which are fixedly arranged between the inner surface of the valve body and the outer surface of the circumferential wall of the upper piston. By means of the spacer bush element and the sealing element, the outer diameter of the upper piston and the cylinder diameter of the foot brake valve can be reduced without changing the size of the valve body, and thus the pedal effort of the foot brake valve is reduced. The foot brake valve can further comprise a pressure difference adjusting mechanism, the pressure difference adjusting mechanism is arranged in the middle piston, the valve body structure of the foot brake valve is more compact, and the pressure difference adjusting mechanism can be easily assembled.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to the technical field of vehicle braking. More particularly, the present disclosure relates to a foot brake valve. BACKGROUND

[0002] Braking, also known as braking, refers to the action of slowing down or stopping a vehicle or other means of transport in motion. During braking, a foot brake valve is usually used to control braking.

[0003] There are various foot brake valves with different cylinder diameters in the prior art, such as a standard foot brake valve with a cylinder diameter of 57 mm, a pressure limiting foot brake valve or low pedal force foot brake valve with a cylinder diameter of 52 mm, a pressure limiting foot brake valve or low pedal force foot brake valve with a cylinder diameter of 47 mm, etc. However, there is currently a demand for further reducing the cylinder diameter of the foot brake valve (such as reducing the cylinder diameter to 42 mm or less) to further reduce the pedal force of the foot brake valve. Considering that the foot brake valve contains many components, and these components need to be manufactured with different molds, it is also desirable to reduce the cylinder diameter as much as possible without changing the size of most components so that these components can be manufactured with their existing molds to reduce manufacturing costs.

[0004] In addition, the foot brake valve usually includes an upper chamber and a lower chamber, and during braking, the compressed gas in the upper chamber can flow to the rear axle of the vehicle for braking through the upper chamber exhaust port, and the compressed gas in the lower chamber can flow to the front axle of the vehicle for braking through the lower chamber exhaust port. In some prior art foot brake valves, there is a pressure difference between the upper chamber exhaust port and the lower chamber exhaust port (for example, the pressure of the upper chamber exhaust port can be higher than that of the lower chamber exhaust port). In some applications, it is desirable that the size of the pressure difference can be adjusted to match the braking of the front axle and the rear axle of the vehicle. In some cases, it is also desirable that the pressure difference adjusting mechanism used can be easily assembled, or the pressure difference can be easily adjusted. SUMMARY

[0005] The purpose of the present disclosure is to solve at least one of the above problems, or to achieve other additional advantages.

[0006] The present disclosure provides a foot brake valve. The foot brake valve includes a valve body, a push element, an upper piston capable of moving downward under the drive of the push element, a first valve capable of opening under the drive of the upper piston, a middle piston capable of moving downward, and a second valve capable of opening under the drive of the middle piston are sequentially arranged in the valve body from top to bottom, wherein the upper piston includes a circumferential wall, and wherein the foot brake valve further includes a spacer element and a sealing element fixedly arranged between the inner surface of the valve body and the outer surface of the circumferential wall of the upper piston.

[0007] According to some embodiments of the present disclosure, the inner surface of the valve body is provided with a lower stop for preventing downward movement of the spacer element, and the foot brake valve comprises a retaining ring for preventing upward movement of the spacer element.

[0008] According to some embodiments of the present disclosure, the inner surface of the valve body is provided with a first annular groove for receiving at least a portion of the retaining ring, the retaining ring being at least partially embedded in the first annular groove.

[0009] According to some embodiments of the present disclosure, the spacer element is configured in a sleeve shape and comprises a first spacer portion and a second spacer portion extending vertically, the first spacer portion having an outer diameter greater than that of the second spacer portion, such that a step is formed between the first spacer portion and the second spacer portion, wherein the step is seated on the lower stop, and the retaining ring is arranged to abut a top of the first spacer portion of the spacer element.

[0010] According to some embodiments of the present disclosure, the sealing element is arranged to abut a bottom of the second spacer portion of the spacer element, and a support element is arranged below the sealing element for preventing downward movement of the sealing element.

[0011] According to some embodiments of the present disclosure, the support element is configured in an annular shape and comprises a protrusion extending radially outward, the inner surface of the valve body is provided with a second annular groove for receiving the protrusion of the support element, the protrusion of the support element being at least partially embedded in the second annular groove.

[0012] According to some embodiments of the present disclosure, the support element comprises a first support portion and a second support portion extending radially outward obliquely relative to the first support portion, the protrusion being arranged radially outward of the second support portion.

[0013] According to some embodiments of the present disclosure, the support element is elastically deformable.

[0014] According to some embodiments of the present disclosure, the upper piston comprises an upper outer piston and an upper inner piston, the spacer element is configured in a sleeve shape and comprises a spacer body extending vertically, the spacer body being arranged between a circumferential wall of the upper outer piston and a circumferential wall of the upper inner piston, an outer side of the spacer body being provided with a flange extending radially outward, wherein a portion of the spacer body below the flange abuts the lower stop of the valve body to prevent downward movement of the spacer element, and the retaining ring is arranged above the flange to prevent upward movement of the spacer element.

[0015] According to some embodiments of the present disclosure, an inner surface of the spacer sleeve body is provided with a groove, and the sealing element is arranged in the groove of the spacer sleeve body and located between the spacer sleeve body and the circumferential wall of the upper inner piston.

[0016] According to some embodiments of the present disclosure, the sealing element is a first sealing element, and the foot brake valve further comprises a second sealing element arranged below the flange of the spacer sleeve body and located between the spacer sleeve body and the valve body.

[0017] According to some embodiments of the present disclosure, the middle piston comprises an axial extension located at the center thereof, the axial extension extends through the first valve to the vicinity of the bottom of the upper piston, and the axial extension is provided with a through inner cavity, and the through inner cavity is provided with a differential pressure adjusting mechanism therein, wherein the differential pressure adjusting mechanism comprises a fixedly arranged pressure regulating spring seat, a pressure regulating spring located above the pressure regulating spring seat, and a pressure regulating top rod seat located above the pressure regulating spring, the pressure regulating top rod seat is capable of moving downward under the drive of the upper piston and is capable of moving upward to reset under the drive of the pressure regulating spring.

[0018] According to some embodiments of the present disclosure, the pressure regulating spring is a compressible coil spring.

[0019] According to some embodiments of the present disclosure, the through inner cavity is provided with a circumferential upper stop portion, and the pressure regulating top rod seat comprises a protruding portion extending radially outward, and the protruding portion of the pressure regulating top rod seat is capable of abutting against the upper stop portion of the through inner cavity to prevent the pressure regulating top rod seat from moving upward out of the through inner cavity.

[0020] According to some embodiments of the present disclosure, the pressure regulating top rod seat comprises a plurality of protruding portions spaced apart from each other.

[0021] According to some embodiments of the present disclosure, the pressure regulating spring seat is fixed in the through inner cavity of the middle piston by a buckle mechanism.

[0022] According to some embodiments of the present disclosure, the buckle mechanism comprises a plurality of circumferential ribs uniformly distributed along the circumference and arranged on the inner surface of the through inner cavity, and a plurality of inverted U-shaped accommodation grooves uniformly distributed along the circumference and arranged on the outer circumferential surface of the pressure regulating spring seat, each circumferential rib is capable of being accommodated in a corresponding one of the inverted U-shaped accommodation grooves to fix the pressure regulating spring seat.

[0023] According to some embodiments of the present disclosure, the inverted U-shaped accommodation groove comprises a circumferential extension and two legs extending downward from both sides of the circumferential extension, and the two ends of each circumferential rib are capable of being defined between the two legs, wherein the two legs have different lengths.

[0024] According to some embodiments of the present disclosure, the pressure regulating spring seat is elastic, and a vertically extending support rib is arranged between the two legs, which can form an interference fit with the circumferential rib.

[0025] According to some embodiments of the present disclosure, the support rib tapers in a radially outward direction and has a triangular cross section.

[0026] According to some embodiments of the present disclosure, the differential pressure regulating mechanism further comprises at least one pressure regulating washer arranged between the pressure regulating spring and the pressure regulating spring seat, and / or between the pressure regulating spring and the pressure regulating top rod seat.

[0027] According to some embodiments of the present disclosure, the foot brake valve has a cylinder diameter of 42 mm.

[0028] According to some embodiments of the present disclosure, the middle piston comprises a middle outer piston and a middle inner piston, the bottom of the middle inner piston being below the bottom of the middle outer piston, so that the middle inner piston moves downward under the drive of the middle outer piston.

[0029] According to some embodiments of the present disclosure, a first gas cavity is formed between the first part of the valve body and the upper piston, a second gas cavity is formed between the second part of the valve body and the first valve, a first communication port is arranged between the first gas cavity and the second gas cavity, and the opening and closing of the first communication port is controlled by the first valve; a third gas cavity is formed between the third part of the valve body and the lower part of the middle piston, a fourth gas cavity is formed between the fourth part of the valve body and the second valve, a second communication port is arranged between the third gas cavity and the fourth gas cavity, and the opening and closing of the second communication port is controlled by the second valve; a fifth gas cavity is further formed between the fifth part of the valve body and the upper part of the middle piston, and the first gas cavity and the fifth gas cavity are in fluid communication; wherein the foot brake valve further comprises a first air inlet, a first air outlet, a second air inlet, and a second air outlet, wherein the first air inlet is in fluid communication with the second gas cavity, the first air outlet is in fluid communication with the first gas cavity, the second air inlet is in fluid communication with the fourth gas cavity, and the second air outlet is in fluid communication with the third gas cavity.

[0030] According to some embodiments of the present disclosure, the first valve and the second valve each comprise a valve body, a valve seat, and a spring arranged between the valve body and the valve seat, wherein the valve body abuts the corresponding first communication port or second communication port, and the valve body can move up and down to open or close the corresponding first communication port or second communication port.

[0031] It is to be noted that aspects of the disclosure described with respect to one embodiment can be incorporated into other different embodiments, although not specifically described with respect to the other different embodiments. In other words, all embodiments and / or features of any embodiment can be combined in any manner and / or combination, as long as they are not mutually contradictory. BRIEF DESCRIPTION OF DRAWINGS

[0032] Aspects of the present disclosure will become more fully understood from the following detailed description, read together with the accompanying drawings, wherein:

[0033] Figure 1 is a front view of a foot brake valve according to one embodiment of the disclosure;

[0034] Figure 2 is a cross-sectional view of a foot brake valve according to one embodiment of the disclosure;

[0035] Figure 3 is a cross-sectional view of an upper valve body of a foot brake valve according to one embodiment of the disclosure;

[0036] Figure 4 and Figure 5 are a perspective view and a cross-sectional view, respectively, of a spacer sleeve of a foot brake valve according to one embodiment of the disclosure;

[0037] Figure 6 and Figure 7 are a perspective view and a cross-sectional view, respectively, of a support ring of a foot brake valve according to one embodiment of the disclosure;

[0038] Figure 8 is a cross-sectional view of a center piston assembly including a differential pressure regulating mechanism according to one embodiment of the disclosure;

[0039] Figure 9 is a perspective view of a pressure regulating top rod seat of a differential pressure regulating mechanism according to one embodiment of the disclosure;

[0040] Figure 10 is a perspective view of a pressure regulating spring seat of a differential pressure regulating mechanism according to one embodiment of the disclosure;

[0041] Figure 11 is a cross-sectional view of a foot brake valve according to another embodiment of the disclosure;

[0042] Figure 12 and Figure 13 are a perspective view and a cross-sectional view, respectively, of a spacer sleeve of a foot brake valve according to another embodiment of the disclosure.

[0043] It is to be understood that like numerals in the drawings represent like elements throughout the several embodiments. In the drawings, the dimensions can be varied and are not necessarily to scale for the sake of clarity. DETAILED DESCRIPTION

[0044] The present disclosure will be described with reference to the accompanying drawings, which show several embodiments thereof. It is understood that the present disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways, thus providing more additional embodiments.

[0045] It should be understood that the language used in the specification has been principally selected for readability and instructional purposes and can not have been selected to delineate or circumscribe the inventive subject matter. That said, the present disclosure has broad applications and the following detailed description does not limit the scope thereof. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. In addition, the articles "a", "an", and "the" are intended to mean that there are one or more (for example, one) of the items. Unless otherwise noted, the terms "including", "comprising", and "having" are intended to be inclusive and not restrictive.

[0046] As used in the description of the disclosure, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. As used herein, the language "includes" as well as "comprising", "containing", "having" and the like are specifically intended to be inclusive and are intended to mean that the item listed is present, but not to the exclusion of one or more additional items which are not specifically recited. As used herein, the language "and / or" comprises any and all combinations of one or more of the associated listed items.

[0047] In the description herein, when an element is referred to as being "on", "attached", "connected", "coupled", or "contacted" to another element, it can be directly on, attached, connected, coupled, or contacted to the other element or one or more intervening elements can also be present.

[0048] In the description herein, the terms "first", "second", "third", etc. are used merely to facilitate the description and are not intended to limit the scope of the disclosure. Any technical features denoted by "first", "second", "third", etc. are interchangeable.

[0049] In the description herein, spatially relative terms such as "upper", "lower", "front", "back", "top", "bottom", etc. can be used for the purpose of explaining the orientation of one feature to another feature in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the drawings. For example, if a device is turned over in the drawings, a feature that is described as being on the bottom of other features would then be oriented upward and the bottom of such other features would now be oriented downward. The device can be oriented in any direction, and the relative spatial terms are intended to include the different orientations of the device in use or operation. The specific spatial

[0050] Reference Figures 1-2FIG. 1 shows a foot brake valve 1 according to one embodiment of the present disclosure. The foot brake valve 1 can be a small-bore, low pedal force foot brake valve. For example, the foot brake valve 1 can have a bore of about 42 mm, which is smaller than the 57 mm bore, 52 mm bore, or 47 mm bore of existing foot brake valves. The foot brake valve 1 can have a top rod force or pedal force of about 1400 N at an output pressure of 10 bar, which is smaller than the pedal force required by existing foot brake valves with 57 mm bore, 52 mm bore, and 47 mm bore.

[0051] The foot brake valve 1 can include a valve body 10. The valve body 10 can be generally cylindrical in shape to accommodate internal components. To facilitate assembly of the foot brake valve 1, in some embodiments, the valve body 10 can include an upper valve body 11 and a lower valve body 12 that are fixedly coupled to each other. However, the present disclosure is not limited thereto. In other embodiments, the valve body 10 can include different numbers of parts, such as one part or three or more parts, as appropriate.

[0052] The valve body 10 of the foot brake valve 1 can include, in order from top to bottom, a push element 20 (e.g., a top rod or push rod), an upper piston 30 that is movable downward under the drive of the push element 20, a first valve 40 that is openable under the drive of the upper piston 30, a middle piston 50 that is movable downward, and a second valve 60 that is openable under the drive of the middle piston 50.

[0053] A spring 70 can be provided between the push element 20 and the upper piston 30. The spring 70 can be compressed under the drive of the push element 20 to transmit a pushing force to the upper piston 30, and can extend after the pushing force is released to reset the push element 20. Similarly, a spring 71 can be provided at the bottom of the upper piston 30 to facilitate resetting of the upper piston 30.

[0054] When assembled into the foot brake valve 1, a first gas cavity A is formed between a first portion 101 of the valve body 10 and the upper piston 30, a second gas cavity B is formed between a second portion 102 of the valve body 10 and the first valve 40, and a first communication port C is provided between the first gas cavity A and the second gas cavity B. The first communication port C is controlled by the first valve 40. Specifically, the first valve 40 can include a valve body 41, a valve seat 42, and a spring 43 between the valve body and the valve seat. As shown, the valve seat 42 can be supported by a support plate 44 and positioned in a cavity formed by the second portion 102 of the valve body 10. The first communication port C is provided at the top of the second portion 102 of the valve body 10, and the valve body 41 is provided to abut the first communication port C. The valve body 41 is movable up and down to open or close the first communication port C. Figure 2 ​

[0055] A third gas chamber D is formed between the third portion 103 of the valve body 10 and the middle piston 50 (more specifically, the lower portion of the middle piston 50), and a fourth gas chamber E is formed between the fourth portion 104 of the valve body 10 and the second valve 60. A second communication port F is provided between the third gas chamber D and the fourth gas chamber E, and the opening and closing of the second communication port F is controlled by the second valve 60. The second valve 60 can have the same structure as the first valve 40, and can include a valve body 61, a valve seat 62, and a spring 63 between the valve body and the valve seat. The valve seat 62 can be supported by a support plate 64 to be positioned in a chamber formed by the fourth portion 104 of the valve body 10. The second communication port F is provided at the top of the fourth portion 104 of the valve body 10, and the valve body 61 is provided to abut the second communication port F. The valve body 61 is movable up and down to open or close the second communication port F.

[0056] In some embodiments, a fifth gas chamber G is further formed between the fifth portion 105 of the valve body 10 and the middle piston 50 (more specifically, the upper portion of the middle piston 50). The first gas chamber A can be configured to be in fluid communication with the fifth gas chamber G. In some embodiments, the first gas chamber A can be configured to be in fluid communication with the fifth gas chamber G and the second gas chamber B. Figure 2 In the illustrated embodiment, the first portion 101, the second portion 102, and the fifth portion 105 of the valve body 10 can be portions of the upper valve body 11, and the third portion 103 and the fourth portion 104 of the valve body 10 can be portions of the lower valve body 12.

[0057] The foot brake valve 1 can further include a first intake port 106, a first exhaust port 107, a second intake port 108, and a second exhaust port 109. The first intake port 106 can be in fluid communication with the second gas chamber B, the first exhaust port 107 can be in fluid communication with the first gas chamber A, the second intake port 108 can be in fluid communication with the fourth gas chamber E, and the second exhaust port 108 can be in fluid communication with the third gas chamber D.

[0058] When the brake pedal is depressed, an external force is applied to the push element 20. The push element 20 drives the upper piston 30 to move downward. The downward movement of the upper piston 30 causes the first valve 40 to open (i.e., the valve body 41 of the first valve 40 is moved downward so as not to block the first communication port C). At this time, compressed gas can enter the second gas chamber B through the first gas inlet 106 and enter the first gas chamber A through the first communication port C. Part of the compressed gas entering the first gas chamber A is output from the first gas outlet 107 (e.g., to the rear axle of the vehicle for braking), and another part can enter the fifth gas chamber G. The compressed gas entering the fifth gas chamber G acts on the middle piston 50, causing the middle piston 50 to move downward, thereby causing the second valve 60 to open (i.e., the valve body 61 of the second valve 60 is moved downward so as not to block the second communication port F). At this time, compressed gas can enter the fourth gas chamber E through the second gas inlet 108 and enter the third gas chamber D through the second communication port F. The compressed gas entering the third gas chamber D is output from the second gas outlet 109 (e.g., to the front axle of the vehicle for braking). During the process of depressing the brake pedal, the pressure of the compressed gas in the first gas chamber A continuously increases until it reaches a level at which the external force can cause the first valve 40 to close, at which time the brake pressure of the first gas outlet 107 remains stable; similarly, the pressure of the compressed gas in the third gas chamber D also continuously increases until the sum of the pressure in the third gas chamber D, the spring force of the spring 63 of the second valve 60, and the friction between the middle piston 50 and the valve body is equal to the pressure in the fifth gas chamber G, at which time the second valve 60 closes, and the brake pressure of the second gas outlet 109 remains stable. Due to the presence of the spring force of the spring 63 of the second valve 60 and the friction between the middle piston 50 and the valve body, the pressure of the first gas outlet 107 is generally higher than that of the second gas outlet 109 when the brake pressure is stable, and thus there is a pressure difference between the two.

[0059] As mentioned above, one of the purposes of the present disclosure is to reduce the cylinder diameter of the foot brake valve to reduce the pedal force of the foot brake valve. To this end, in the embodiment according to the present disclosure, a spacer element and a sealing element are provided between the inner surface of the foot brake valve and the outer surface of the upper piston. The spacer element and the sealing element are fixed, and the upper piston can move up and down relative to the spacer element and the sealing element, thereby reducing the outer diameter of the upper piston and the cylinder diameter of the foot brake valve (e.g., to 42 mm) without changing the size of the valve body, and thereby reducing the pedal force of the foot brake valve (e.g., when the output pressure is 10 bar, the pedal force can be reduced to about 1400 N). By means of the spacer element and the sealing element, since the size of the valve body does not need to be changed, the valve body can still be manufactured using existing molds (e.g., existing molds for manufacturing valve bodies with a size of 47 mm or more) or existing valve bodies, thereby saving manufacturing costs.

[0060] Referring to Figures 2-7 , the spacer element, the sealing element, and the structure and arrangement thereof according to one embodiment of the present disclosure will be described in detail.

[0061] As Figure 2 shown, the upper piston 30 can include a circumferential wall 31 and a bottom wall 32, such that the upper piston 30 is generally cup-shaped. The upper piston 30 can further include a first extension post 33 extending upwardly from the center of the bottom wall 32 and a second extension post 34 extending downwardly from the center of the bottom wall 32.

[0062] The spacer element 35 and the sealing element 36 can be fixedly disposed between the inner surface of the valve body 10 (the upper valve body 11 in the embodiment shown) and the outer surface of the circumferential wall 31 of the upper piston 30. Figure 2

[0063] As Figure 3 shown, in order to prevent the spacer element 35 from moving downwardly, the inner surface of the upper valve body 11 can be provided with a lower stopper 111. The lower stopper 111 can be configured as an annular stepped portion. In addition, in order to prevent the spacer element 35 from moving upwardly, a retaining ring 37 can be provided. The retaining ring 37 can be a metal retaining ring. In order to fix the retaining ring 37, as Figure 3 shown, the inner surface of the upper valve body 11 can be provided with a first annular groove 112 for receiving at least a portion of the retaining ring 37. The retaining ring 37 can be at least partially embedded in the first annular groove 112.

[0064] As Figure 4 and Figure 5 shown, in some embodiments according to the present disclosure, the spacer element 35 can be configured as a cylinder. The spacer element 35 can include a first spacer portion 351 and a second spacer portion 352 extending vertically. The outer diameter of the first spacer portion 351 can be greater than the outer diameter of the second spacer portion 352, such that a stepped portion 353 is formed between the first spacer portion 351 and the second spacer portion 352. The stepped portion 353 can be seated on the lower stopper 111 to prevent the spacer element 35 from moving downwardly. The retaining ring 37 can be provided to abut against the top of the first spacer portion 351 of the spacer element 35 to prevent the spacer element 35 from moving upwardly. In some embodiments according to the present disclosure, the inner surface of the spacer element 35 can include an annular recess 354. The presence of the annular recess 354 can reduce the contact area between the inner surface of the spacer element 35 and the outer surface of the upper piston 30, thereby reducing the frictional force suffered by the upper piston 30 when moving up and down. In some embodiments according to the present disclosure, the spacer element 35 can be made of plastic.

[0065] In Figure 2 ​In the illustrated embodiment, the sealing element 36 is disposed below the spacer element 35. More specifically, the sealing element 36 may be configured to abut the bottom of the second spacer portion 352 of the spacer element 35. The sealing element 36 may be a sealing ring having a circular cross-section. To prevent the sealing element 36 from moving downward, a support element 38 may be disposed below the sealing element 36.

[0066] Reference Figure 6 and Figure 7 In some embodiments according to this disclosure, the support element 38 may be configured as annular. The support element 38 may include radially outwardly extending protrusions 381 for positioning the support element 38. Specifically, the inner surface of the upper valve body 11 may be provided with a second annular groove 113 for receiving the protrusions 381 of the support element 38, such as... Figure 3 As shown. The protrusion 381 of the support element can be at least partially embedded in the second annular groove 113, thereby positioning the support element 38. The protrusion 381 of the support element can be an annular protrusion that matches the second annular groove 113.

[0067] In some embodiments, the support element 38 may be configured to elastically deform, such that its protrusion 381 is more securely embedded in the second annular groove 113, thereby providing a more secure positioning of the support element 38. In some embodiments, the support element 38 may include a first support portion 382 and a second support portion 383 extending radially outward at a slightly inclined angle relative to the first support portion 382. The protrusion 381 may be disposed radially outward of the second support portion 383. The inclined extension of the second support portion 383 allows the protrusion 381 to be more securely embedded in the second annular groove 113, thereby providing a more secure positioning of the support element 38.

[0068] In other embodiments according to this disclosure, the spacer element 35 and the sealing element 36 may have other different structures and other different positioning methods.

[0069] As mentioned above, another object of this disclosure is to be able to adjust the pressure difference between the first exhaust port 107 and the second exhaust port 109 to match the braking of the front and rear axles of the vehicle. To this end, in some embodiments according to this disclosure, the foot brake valve 1 may include a pressure differential adjustment mechanism.

[0070] Reference Figures 8-10 The differential pressure regulating mechanism 80 according to one embodiment of the present disclosure will be described in detail. The differential pressure regulating mechanism 80 may be disposed in the intermediate piston 50.

[0071] Specifically, the middle piston 50 may include an axial extension 51 located at its center. The axial extension 51 may extend through the first valve 40 to near the bottom of the upper piston 30 (see [link to original text]).Figure 2 The axial extension 51 can have a through-bore 52, and the differential pressure regulating mechanism 80 can be disposed in the through-bore 52.

[0072] The differential pressure regulating mechanism 80 can include a fixedly disposed pressure regulating spring seat 81, a pressure regulating spring 82 located above the pressure regulating spring seat 81, and a pressure regulating top rod seat 83 located above the pressure regulating spring 82. The pressure regulating top rod seat 83 is capable of abutting against the bottom of the second extension column 34 of the upper piston 30, so that it is capable of moving downward under the drive of the upper piston 30 (more specifically, the second extension column 34 of the upper piston 30). The pressure regulating top rod seat 83 is also capable of moving upward to reset under the drive of the pressure regulating spring 82, and for this purpose, the pressure regulating spring 82 can be configured as a compressible coil spring.

[0073] In order to prevent the pressure regulating top rod seat 83 from moving upward out of the through-bore 52, as shown in Figure 8 , a circumferential upper stop portion 53 is provided inside the through-bore 52. Correspondingly, as shown in Figure 9 , the pressure regulating top rod seat 83 can include a radially outwardly extending protruding portion 831 capable of abutting against the upper stop portion 53 of the through-bore 52 to prevent the pressure regulating top rod seat 83 from moving upward out of the through-bore 52. In the embodiment shown in Figure 9 , the pressure regulating top rod seat 83 includes a plurality of protruding portions 831 (such as three or more) spaced apart from each other. In other embodiments, the pressure regulating top rod seat 83 can also include only one protruding portion 831, such as a continuous protruding portion in the form of a ring.

[0074] The pressure regulating spring seat 81 can be fixed inside the through-bore 52 of the middle piston 50 by a snap mechanism. In some embodiments according to the present disclosure, the snap mechanism can include a plurality of (such as two, three or more) circumferentially uniformly distributed circumferential ribs 54 (see Figure 8 ) provided on the inner surface of the through-bore 52 of the middle piston 50 and a plurality of (such as two, three or more) circumferentially uniformly distributed inverted U-shaped receiving grooves 811 (see Figure 10 ) provided on the outer peripheral surface of the pressure regulating spring seat 81. Each circumferential rib 54 is capable of being received in a corresponding one of the inverted U-shaped receiving grooves 811 to fix the pressure regulating spring seat 81. In some embodiments, the circumferential rib 54 can also include a vertical rib 55 extending downward from a substantially central position of the circumferential rib 54 to enhance the support strength of the circumferential rib 54.

[0075] As shown in Figure 10As shown, the pressure regulating spring seat 81 can have a cylindrical body. The inverted U-shaped accommodation grooves 811 can be arranged on the outer circumferential surface of the cylindrical body at intervals. The inverted U-shaped accommodation grooves 811 can include a circumferential extension 812 and two legs 813 and 814 extending downward from both sides of the circumferential extension 812. Both ends of each circumferential rib 54 can be defined between the two legs 813 and 814. In Figure 10 In the embodiment shown, the two legs 813 and 814 have different lengths, for example, the length of the leg 813 is shorter than that of the leg 814. Such a configuration makes it possible, when installing the pressure regulating spring seat 81, to rotate the pressure regulating spring seat 81 to rotate the circumferential rib 54 from the side of the shorter leg 813 into the inverted U-shaped accommodation groove 811 until one end of the circumferential rib 54 abuts against the longer leg 814. At this time, both ends of the circumferential rib 54 will be defined between the two legs 813 and 814, and the top surface 541 of the circumferential rib 54 will abut against the bottom surface 815 of the circumferential extension 812 of the inverted U-shaped accommodation groove 811, so that the pressure regulating spring seat 81 is fixed in the through inner cavity 52.

[0076] In some embodiments according to the present disclosure, the pressure regulating spring seat 81 can have elasticity so that it can be elastically compressed and installed in the through inner cavity 52, so that it is more firmly fixed. In some embodiments, a vertically extending support rib 816 can also be arranged between the two legs 813 and 814 of the pressure regulating spring seat 81. The support rib 816 can abut against and form an interference fit with the circumferential rib 54, which also makes it possible for the pressure regulating spring seat 81 to be more firmly fixed. In some embodiments, as shown, Figure 10 As shown, the support rib 816 can taper in the radially outward direction and can have a triangular cross section.

[0077] In embodiments according to the present disclosure, the cylinder diameter of the middle piston 50 is about 42.5 mm, and by arranging the pressure differential adjusting mechanism 80 in the through inner cavity 52 of the middle piston 50, the valve body structure of the foot brake valve 1 according to the present disclosure is more compact and smaller in volume compared with existing foot brake valves that integrate a pressure differential adjusting mechanism. In addition, the pressure differential adjusting mechanism 80 according to the present disclosure can be more easily assembled. For example, when assembling the pressure differential adjusting mechanism 80 according to the present disclosure, the pressure regulating top rod seat 83, the pressure regulating spring 82 and the pressure regulating spring seat 81 can be sequentially installed from below the middle piston 50. In particular, when assembling the pressure regulating spring seat 81 according to the present disclosure, it is only necessary to first place it in the through inner cavity 52, and then rotate the pressure regulating spring seat 81 so that the circumferential rib 54 in the through inner cavity 52 is accommodated in the inverted U-shaped accommodation groove 811 of the pressure regulating spring seat 81.

[0078] According to the differential pressure regulating mechanism 80 of this disclosure, the pressure difference between the first exhaust port 107 and the second exhaust port 109 of the foot brake valve 1 is adjusted by means of an additional spring force generated by the pressure regulating spring 82. Specifically, when the upper piston 30 moves downward, its second extension post 34 drives the pressure regulating rod seat 83 of the differential pressure regulating mechanism 80 downward. The pressure regulating rod seat 83 compresses the pressure regulating spring 82, thereby generating an additional spring force in the pressure regulating spring 82. This additional spring force, together with the compressed gas in the fifth gas chamber G, drives the middle piston 50 downward and opens the second valve 60. The additional spring force of the pressure regulating spring 82 can at least partially offset the spring force of the spring 63 of the second valve 60 and the frictional force between the middle piston 50 and the valve body, thereby adjusting the pressure difference between the first exhaust port 107 and the second exhaust port 109 to the desired value.

[0079] The pressure difference between the first exhaust port 107 and the second exhaust port 109 can be adjusted by changing the additional spring force generated by the adjusting spring 82. For example, adjusting springs 82 with different elastic coefficients, different thicknesses, or different lengths can be selected to generate the desired additional spring force to adjust the pressure difference between the first exhaust port 107 and the second exhaust port 109 to the desired value. In some embodiments, the pressure difference adjustment mechanism 80 may also include at least one adjusting washer, and the pressure difference can be adjusted by adding or removing the adjusting washer to change the pre-compression force of the adjusting spring 82 and thus change the additional spring force generated by the adjusting spring 82. When the pressure difference adjustment mechanism 80 includes an adjusting washer, the adjusting washer may be disposed between the adjusting spring 82 and the adjusting spring seat 81, and / or between the adjusting spring 82 and the adjusting push rod seat 83. In some embodiments according to this disclosure, such as Figure 2 As shown, a compressible return spring 84 can also be installed below the pressure regulating spring seat 81.

[0080] Next, refer to Figures 11-13 The diagram shows a foot brake valve 2 according to another embodiment of the present disclosure. Foot brake valve 2 has a similar structure to foot brake valve 1, therefore, the same parts will not be described in detail, but only the differences between foot brake valve 2 and foot brake valve 1 will be described.

[0081] The foot brake valve 2 includes a valve body 2.1. The upper piston of the foot brake valve 2 may include an upper outer piston 2.2 and an upper inner piston 2.3. The upper outer piston 2.2 is inverted cup-shaped and includes a circumferential wall 2.21, and the upper inner piston 2.3 is cup-shaped and includes a circumferential wall 2.31. The diameter of the circumferential wall 2.21 of the upper outer piston 2.2 is larger than the diameter of the circumferential wall 2.31 of the upper inner piston 2.3, and the upper outer piston 2.2 is positioned above the upper inner piston 2.3.

[0082] The middle piston of the foot brake valve 2 can include a middle outer piston 2.4 and a middle inner piston 2.5. The bottom of the middle inner piston 2.5 can be located below the bottom of the middle outer piston 2.4, so that the middle inner piston 2.5 is driven to move downward by the middle outer piston 2.4.

[0083] A spacer element 2.6 is fixedly arranged between the inner surface of the valve body 2.1 of the foot brake valve 2 and the circumferential wall 2.31 of the upper inner piston 2.3. Unlike the spacer element 35, the spacer element 2.6 is configured in a sleeve shape and includes a spacer body 2.61 extending vertically. As shown, the spacer body 2.61 can be arranged between the circumferential wall 2.21 of the upper outer piston 2.2 and the circumferential wall 2.31 of the upper inner piston 2.3. The outer side of the spacer body 2.61 is provided with a flange 2.62 extending radially outward. The inner surface of the valve body 2.1 of the foot brake valve 2 is provided with a lower stop 2.11 for preventing the spacer element 2.6 from moving downward. As shown, the lower stop 2.11 is configured as an annular inclined portion. The portion of the spacer body 2.61 below the flange 2.62 can abut against the lower stop 2.11 of the valve body 2.1 to prevent the spacer element 2.6 from moving downward. In order to prevent the spacer element 2.6 from moving upward, a retaining ring 2.7 is arranged in the foot brake valve 1. The retaining ring 2.7 can be arranged above the flange 2.62 of the spacer element 2.6. Similarly, the retaining ring 2.7 can be embedded in an annular groove of the valve body 2.1 of the foot brake valve. Figure 11 Figure 11

[0084] The foot brake valve 2 can include a first sealing element 2.8. The first sealing element 2.8 can be arranged between the inner surface of the spacer body 2.61 of the spacer element 2.6 and the outer surface of the circumferential wall 2.31 of the upper inner piston 2.3. To this end, the inner surface of the spacer body 2.61 can be provided with a groove 2.63, and the first sealing element 2.8 can be arranged in the groove 2.63. The upper inner piston 2.3 can move up and down relative to the spacer element 2.6 and the first sealing element 2.8.

[0085] Similarly to the foot brake valve 1, in the foot brake valve 2, by means of the spacer element 2.6 and the first sealing element 2.8, the outer diameter of the upper inner piston 2.3 and the cylinder diameter of the foot brake valve 2 can be reduced without changing the size of the valve body 2.1 (for example, to 42 mm), and thus the pedal force of the foot brake valve 2 can be reduced (for example, to about 1400 N when the output pressure is 10 bar).

[0086] In some embodiments, the foot brake valve 2 can further include a second sealing element 2.9, which can be arranged below the flange 2.62 of the spacer body 2.61 and between the spacer body 2.61 and the valve body 2.1.

[0087] ​​In the foot brake valve 2, a differential pressure adjusting mechanism can not be provided. However, the present disclosure is not limited thereto, and a suitable differential pressure adjusting mechanism can also be provided in the foot brake valve 2 if necessary.

[0088] The exemplary embodiments according to the present disclosure are described above with reference to the accompanying drawings. However, it will be understood by those skilled in the art that various changes and modifications can be made to the exemplary embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. All changes and modifications are intended to be included within the scope of the present disclosure as defined by the claims. The present disclosure is defined by the appended claims, and equivalents thereto are intended to be included therein.

Claims

1. A foot brake valve, characterized in that The foot brake valve comprises a valve body, which is provided with, from top to bottom, a push element, an upper piston capable of moving downward under the drive of the push element, a first valve capable of opening under the drive of the upper piston, a middle piston capable of moving downward, and a second valve capable of opening under the drive of the middle piston, wherein the upper piston comprises a circumferential wall, and wherein the foot brake valve further comprises a spacer element and a sealing element fixedly arranged between the inner surface of the valve body and the outer surface of the circumferential wall of the upper piston.

2. Foot brake valve according to claim 1, characterized in that The inner surface of the valve body is provided with a lower stop for preventing the spacer element from moving downward, and the foot brake valve comprises a retainer ring for preventing the spacer element from moving upward.

3. The foot brake valve according to claim 2, characterized in that The inner surface of the valve body is provided with a first annular groove for receiving at least a portion of the retainer ring, and the retainer ring is at least partially embedded in the first annular groove.

4. The foot brake valve according to claim 2, characterized in that The spacer element is sleeve-shaped and comprises a first spacer portion and a second spacer portion extending vertically, the outer diameter of the first spacer portion being larger than that of the second spacer portion, so that a step is formed between the first spacer portion and the second spacer portion, wherein the step is seated on the lower stop, and the retainer ring is arranged to abut the top of the first spacer portion of the spacer element.

5. The foot brake valve according to claim 4, characterized in that The sealing element is arranged to abut the bottom of the second spacer portion of the spacer element, and a support element is arranged below the sealing element for preventing the sealing element from moving downward.

6. The foot brake valve according to claim 5, characterized in that The support element is annular and comprises a protrusion extending radially outward, and the inner surface of the valve body is provided with a second annular groove for receiving the protrusion of the support element, and the protrusion of the support element is at least partially embedded in the second annular groove.

7. The foot brake valve according to claim 6, characterized in that The support element comprises a first support portion and a second support portion extending radially outward obliquely relative to the first support portion, and the protrusion is arranged radially outward of the second support portion.

8. The foot brake valve according to claim 6, characterized in that The support element is elastically deformable.

9. The foot brake valve according to claim 2, characterized in that The upper piston comprises an upper outer piston and an upper inner piston, the spacer element is sleeve-shaped and comprises a spacer body extending vertically, the spacer body is arranged between the circumferential wall of the upper outer piston and the circumferential wall of the upper inner piston, and the outer side of the spacer body is provided with a flange extending radially outward, wherein the portion of the spacer body below the flange abuts the lower stop of the valve body to prevent the spacer element from moving downward, and the retainer ring is arranged above the flange to prevent the spacer element from moving upward.

10. The foot brake valve according to claim 9, characterized in that The inner surface of the spacer body is provided with a recess, and the sealing element is arranged in the recess of the spacer body and between the spacer body and the circumferential wall of the upper inner piston.

11. The foot brake valve according to claim 10, characterized in that The sealing element is a first sealing element, and the foot brake valve further comprises a second sealing element arranged below the flange of the spacer body and between the spacer body and the valve body.

12. The foot brake valve according to claim 1, characterized in that The middle piston comprises an axial extension in the center thereof, the axial extension extending through the first valve to the vicinity of the bottom of the upper piston, and the axial extension having a through inner cavity, and a differential pressure regulating mechanism is arranged in the through inner cavity, The differential pressure regulating mechanism comprises a pressure regulating spring seat fixedly arranged, a pressure regulating spring arranged above the pressure regulating spring seat, and a pressure regulating top rod seat arranged above the pressure regulating spring, the pressure regulating top rod seat being capable of moving downward under the drive of the upper piston and being capable of moving upward under the drive of the pressure regulating spring and resetting.

13. The foot brake valve according to claim 12, characterized in that The pressure regulating spring is a compressible coil spring.

14. The foot brake valve according to claim 12, characterized in that The through inner cavity is provided with a circumferential upper stop portion, and the pressure regulating top rod seat comprises a protruding portion extending radially outward, the protruding portion of the pressure regulating top rod seat being capable of abutting against the upper stop portion of the through inner cavity to prevent the pressure regulating top rod seat from moving upward out of the through inner cavity.

15. The foot brake valve according to claim 14, characterized in that The pressure regulating top rod seat comprises a plurality of protruding portions spaced apart from each other.

16. The foot brake valve according to claim 12, characterized in that The pressure regulating spring seat is fixed in the through inner cavity of the middle piston by a buckle mechanism.

17. The foot brake valve according to claim 16, characterized in that The buckle mechanism comprises a plurality of circumferential ribs uniformly distributed in a circle and arranged on the inner surface of the through inner cavity and a plurality of inverted U-shaped accommodating grooves uniformly distributed in a circle and arranged on the outer peripheral surface of the pressure regulating spring seat, each circumferential rib being capable of being accommodated in a corresponding one of the inverted U-shaped accommodating grooves to fix the pressure regulating spring seat.

18. The foot brake valve according to claim 17, characterized in that The inverted U-shaped accommodating groove comprises a circumferential extension and two legs extending downward from both sides of the circumferential extension, and the two ends of each circumferential rib are capable of being defined between the two legs, wherein the two legs have different lengths.

19. The foot brake valve according to claim 18, characterized in that The pressure regulating spring seat is elastic, and a support rib extending vertically is arranged between the two legs, the support rib being capable of forming an interference fit with the circumferential rib.

20. The foot brake valve according to claim 19, characterized in that The support rib tapers in a radial outward direction and has a triangular cross section.

21. The foot brake valve according to claim 12, characterized in that The differential pressure regulating mechanism further comprises at least one pressure regulating gasket arranged between the pressure regulating spring and the pressure regulating spring seat and / or arranged between the pressure regulating spring and the pressure regulating top rod seat.

22. The foot brake valve according to any one of claims 1 to 21, characterized in that The foot brake valve has a cylinder diameter of 42 mm.

23. The foot brake valve according to any one of claims 9 to 11, characterized in that The middle piston comprises a middle outer piston and a middle inner piston, the bottom of the middle inner piston being below the bottom of the middle outer piston, so that the middle inner piston moves downward under the drive of the middle outer piston.

24. The foot brake valve according to any one of claims 1 to 21, characterized in that A first gas cavity is formed between the first part of the valve body and the upper piston, a second gas cavity is formed between the second part of the valve body and the first valve, a first communication port is arranged between the first gas cavity and the second gas cavity, and opening and closing of the first communication port is controlled by the first valve; a third gas cavity is formed between the third part of the valve body and the lower part of the middle piston, a fourth gas cavity is formed between the fourth part of the valve body and the second valve, a second communication port is arranged between the third gas cavity and the fourth gas cavity, and opening and closing of the second communication port is controlled by the second valve; a fifth gas cavity is further formed between the fifth part of the valve body and the upper part of the middle piston, and the first gas cavity and the fifth gas cavity are in fluid communication. The foot brake valve further comprises a first air inlet, a first air outlet, a second air inlet, and a second air outlet, wherein the first air inlet is in fluid communication with the second gas cavity, the first air outlet is in fluid communication with the first gas cavity, the second air inlet is in fluid communication with the fourth gas cavity, and the second air outlet is in fluid communication with the third gas cavity.

25. The foot brake valve according to claim 24, characterized in that The first valve and the second valve each comprise a valve body, a valve seat, and a spring between the valve body and the valve seat, wherein the valve body abuts the corresponding first communication port or second communication port, and the valve body can move up and down to open or close the corresponding first communication port or second communication port.

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