CN213451916U - Differential pressure valve - Google Patents

Abstract

The utility model relates to a differential pressure valve, including the vertical valve body that sets up and have the valve pocket, be equipped with the check valve that two structures are the same and parallelly connected intercommunication in the valve pocket, every check valve all includes the valve port and can the elasticity support by the case on the up end of valve port, supports a spring in the top of case, and the case includes metal framework, has seted up the annular at metal framework's lower terminal surface, is equipped with the vulcanite spare at the embedded annular. The outer side of the upper end face of the valve port is a plane, the inner side of the upper end face of the valve port is convex upwards to form an annular bulge, and the vertical height of the annular bulge is 0.6-1 mm. The annular bulge is arranged right opposite to the lower end face of the vulcanized rubber piece, and the plane is arranged right opposite to the outer edge of the lower end face of the metal framework. The utility model discloses a differential pressure valve can protect vulcanized rubber spare to the at utmost, and the theoretical pressure differential of avoiding long-time back differential pressure valve to use diminishes, has increased the reliability of differential pressure valve.

Description

Differential pressure valve

Technical Field

The utility model relates to a rail transit technical field especially relates to a differential pressure valve, the differential pressure valve that vehicle air suspension system used among the specially adapted rail transit field.

Background

In the air suspension system of the rail transit vehicle, the air spring is an important measure for improving the dynamic quality of a bogie and improving the running stability of the vehicle. Many advantages of the air spring can be fully exerted only by adopting a height adjusting device with excellent performance, and the automatic height adjusting device of the air spring comprises a height adjusting valve, a differential pressure valve and a connecting rod. The height adjusting valve is used for automatically increasing or decreasing the air pressure in the air spring when the height of the air spring changes according to the increase or decrease of the vehicle load, so that the air spring is always kept at a certain height. The arrangement of the differential pressure valve in the air suspension system is shown in figure 1, the height adjusting valve 02 is connected with the corresponding air spring, the differential pressure valve 01 is arranged between the left air spring 03 and the right air spring 04 of the same bogie, and the air springs on two sides are connected through a pipeline, so that the differential pressure valve can play a certain role in adjusting the pressure difference between the left air spring 03 and the right air spring 04.

When the air bag of one side of the air spring of the same bogie is suddenly broken or damaged or the air is filled and exhausted by the height adjusting valve, so that the pressure of the air spring on one side is changed, the pressure difference of the air springs on two sides is larger than the theoretical pressure difference, the internal one-way valve is opened by the differential pressure valve, the air springs on two sides are conducted, the air is filled into the low-pressure side from the high-pressure side, and the differential pressure valve is closed again until the pressure difference on two sides is reduced to be lower than the theoretical pressure difference. The differential pressure valve keeps the air spring pressure on the two sides of the bogie balanced, so that the stability and comfort of the vehicle in the running process can be ensured, and the safe operation of the vehicle is finally ensured.

However, the differential pressure valve is installed under a vehicle, so that the operation space is narrow, the field maintenance and operation are difficult, the differential pressure valve is exposed in the atmosphere, the application working condition and environment are severe, and the reliability of the differential pressure valve is insufficient due to the influences of rain, snow, wind, sand, oil corrosion and the like. With the long-term use of the differential pressure valve, the theoretical differential pressure of the differential pressure valve becomes small.

In the prior art, if a theoretical differential pressure of a differential pressure valve is adjusted, the differential pressure valve needs to be detached from a vehicle, returned to a factory for maintenance, replaced with parts and the like, and the differential pressure valve is extremely complex.

Another type's differential pressure valve has adjusting device, can realize the further compression to the spring through rotating adjusting device, accomplishes the adjustment to the spring pre-compaction volume from this for the differential pressure valve obtains repairing, and need not disassemble the differential pressure valve, also need not change the spare part of differential pressure valve. Therefore, the theoretical differential pressure of the differential pressure valve can be adjusted on the vehicle body, and complicated processes of disassembling the differential pressure valve from the vehicle, returning to a factory for maintenance and the like are avoided.

The method mainly starts from the quick adjustment of the theoretical pressure difference, and partially solves the problem of complicated process in reality. However, in reality, because the pneumatic valve related to a specific action value is supplied to a user after the theoretical differential pressure is adjusted, the user usually clearly requires that the adjusting device related to the adjustment action value must be additionally provided with a lead seal or be coated with a locking mark. When the differential pressure valve is installed, the anti-loosening mark of the adjusting device of the differential pressure valve is clear and definite, and the adjusting device of the differential pressure valve is not allowed to be readjusted in a maintenance period. The adjusting device is coated with the anti-loosening mark, so that on one hand, a user can stably and reliably demand the action value of the differential pressure valve in the service life cycle, and on the other hand, a differential pressure valve supplier can be protected after the theoretical differential pressure of the differential pressure valve supplier is adjusted, and the personal adjustment of untrained personnel is avoided. Therefore, the differential pressure valve with the regulating device is often more applied to the adjustment before the differential pressure valve is installed or the debugging before the differential pressure valve leaves a factory, and the adjustment of the regulating device is not allowed after the differential pressure valve is installed in a vehicle.

When the differential pressure valve is out of tolerance theoretically in the vehicle operation process, whether a user or a supplier firstly needs to be butted and confirmed, namely whether the anti-loosening mark of the adjusting device is misplaced or not, and whether a person personally adjusts the adjusting device to cause the action value of the differential pressure valve to be out of tolerance or not. If the adjusting device is adjusted on site after loading, the two parties must agree to obtain the authorization of the other party. Therefore, in order to adjust the compression amount of the spring for the loaded differential pressure valve, user authorization must be obtained, and the method is generally suitable for solving the problem that the vehicle is emergently taken out of a warehouse and operated on line, or carrying out test verification during debugging.

Therefore, how to increase the reliability of the differential pressure valve to avoid the theoretical differential pressure from becoming small after long-time use to the greatest extent becomes a problem which needs to be solved urgently at present to meet the market demand.

Therefore, the inventor provides a differential pressure valve by virtue of experience and practice of related industries for many years so as to overcome the defects of the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a differential pressure valve can protect vulcanized rubber spare by at utmost, and the theoretical differential pressure of avoiding long-time back differential pressure valve to use diminishes, has increased the reliability of differential pressure valve.

The utility model aims at realizing the differential pressure valve, which comprises a valve body which is vertically arranged and is provided with a valve cavity, wherein two check valves which have the same structure and are communicated in parallel are arranged in the valve cavity, each check valve comprises a valve port and a valve core which can elastically abut against the upper end surface of the valve port, a spring is abutted against the upper part of the valve core, the valve core comprises a metal framework, the lower end surface of the metal framework is provided with an annular groove, and a vulcanized rubber part is embedded in the annular groove; the outer side of the upper end face of the valve port is a plane, the inner side of the upper end face of the valve port is convex upwards to form an annular bulge, and the vertical height of the annular bulge is 0.6-1 mm; the annular bulge is arranged right opposite to the lower end face of the vulcanized rubber piece, and the plane is arranged right opposite to the outer edge of the lower end face of the metal framework.

In a preferred embodiment of the present invention, the outer wall of the annular protrusion is a tapered surface with an upward tapered outer diameter, and a transition arc surface is formed at a connection between the upper end edge of the tapered surface and the inner wall of the annular protrusion.

In a preferred embodiment of the present invention, the lower end surface of the vulcanized rubber member extends out of the lower end surface of the metal frame, and the vertical height of the extension is 0.1 mm.

The present invention provides a preferred embodiment, wherein each check valve further comprises an adjusting mechanism disposed on the valve body, and the adjusting mechanism is connected to the spring and can adjust the compression amount of the spring.

In a preferred embodiment of the present invention, the adjusting mechanism includes a guiding sleeve and an adjusting screw, the guiding sleeve is a tubular structure with a closed bottom and an open top, the outer side of the upper end of the guiding sleeve is provided with a convex ring in an outward protruding manner, the outer edge of the upper end of the valve core is provided with a concave surface, and two ends of the spring respectively prop against the lower surface and the concave surface of the convex ring; the valve body is provided with a threaded hole, the adjusting screw rod can be adjustably inserted into the threaded hole, and the end part of the adjusting screw rod is abutted against the upper surface of the bottom of the guide sleeve.

In a preferred embodiment of the present invention, a seal ring is interposed between the adjusting screw and the threaded hole.

The utility model discloses an in a preferred embodiment, all install the nut at the top of every check valve, nut and valve body sealing connection, the screw hole is seted up on the nut.

The present invention provides a preferred embodiment, wherein the adjusting screw is provided with a limiting ring, the limiting ring is formed by the inward protruding portion of the nut, and the nut is provided with an upper limiting portion which can limit the upper end surface of the limiting ring and a lower limiting portion which can limit the lower end surface of the limiting ring.

In a preferred embodiment of the present invention, the nut is a cylindrical structure with a downward opening, and an annular inner plug is formed by extending downward on the inner surface of the top of the nut; the periphery of the annular inner plug is sleeved with a threaded sleeve, and the guide sleeve is sleeved outside the threaded sleeve; the threaded sleeve is of a cylindrical structure with an upward opening, a central hole is formed in the bottom of the threaded sleeve, the threaded hole, the annular inner plug and the central hole are coaxially arranged, and the inner diameter of the annular inner plug is larger than the aperture of the threaded hole and the aperture of the central hole; the annular part of the top inner surface of the nut and located between the threaded hole and the annular inner plug forms an upper limiting part, and the annular part of the bottom inner surface of the nut and located between the central hole and the annular inner plug forms a lower limiting part.

In a preferred embodiment of the present invention, the inner wall of the guiding sleeve and the outer wall of the nut are in clearance fit.

In a preferred embodiment of the present invention, the two check valves are respectively referred to as a first check valve and a second check valve, the valve cavity includes a first valve cavity and a second valve cavity, and the first check valve and the second check valve are respectively disposed in the first valve cavity and the second valve cavity; the valve port of the first check valve divides the first valve cavity into a first upper chamber and a first lower chamber, and the valve port of the second check valve divides the second valve cavity into a second upper chamber and a second lower chamber; the first upper chamber is communicated with the second lower chamber through a first channel, the first lower chamber is communicated with the second upper chamber through a second channel, and an input port communicated with the first lower chamber and an output port communicated with the second lower chamber are formed in the side portion of the valve body.

In a preferred embodiment of the present invention, the filter is disposed at both the input port and the output port.

From top to bottom, the utility model provides a special design is done through the up end to the valve port to utilize metal framework to vulcanized rubber spare's guard action, can guarantee vulcanized rubber spare and valve port sealing contact, guarantee the leakproofness. Meanwhile, when the compression amount of the spring is further increased, the metal framework can abut against the plane of the valve port and mainly bears the force, so that the vulcanized rubber part can be protected to a certain extent; because the height of the annular bulge is limited to 0.6-1 mm, no matter how much force is applied to the valve core by the spring, the vulcanized rubber piece can be prevented from being further compressed, the compression amount of the vulcanized rubber piece can be controlled within a certain range, the depth of the maximum indentation of the vulcanized rubber piece is controlled within 0.6-1 mm, and the indentation is prevented from being too deep. The sealing performance of the vulcanized rubber piece can be guaranteed, the aging damage of the vulcanized rubber piece is prevented or delayed to the maximum extent, the action value of the differential pressure valve after loading is guaranteed not to be out of tolerance, and the problem that the theoretical differential pressure of the differential pressure valve becomes small after long-time use is avoided to the maximum extent. Simultaneously, can also alleviate the adhesion phenomenon between vulcanite spare and the valve port well, can also avoid the differential pressure valve value adjustment in-process frequently to operate or the maloperation leads to the damage to vulcanite spare effectively, improved the reliability of differential pressure valve greatly.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: the layout of the differential pressure valve in the air suspension system is shown schematically.

FIG. 2: do the utility model provides a structural schematic diagram of differential pressure valve one.

FIG. 3: which is a partial enlargement at C in fig. 2.

FIG. 4: an enlarged view of a portion of the valve port of figure 3.

FIG. 5: does the utility model provides a structural schematic diagram of case.

FIG. 6: which is an enlarged view of a portion at D in fig. 2.

FIG. 7: do the utility model provides a overlook the cross-sectional view of valve body.

FIG. 8: do the utility model provides a main sectional view first of valve body.

FIG. 9: do the utility model provides a main sectional view of valve body two.

FIG. 10: do the utility model provides a structural schematic diagram two of differential pressure valve. Wherein the arrows within the valve cavity in fig. 10 represent the direction of airflow.

The reference numbers illustrate:

01. a differential pressure valve; 02. a leveling valve; 03. a left air spring; 04. and a right air spring.

1. A valve body;

11. a valve cavity; A. a first valve chamber; a1, a first upper chamber; a2, first lower chamber; B. a second valve cavity; b1, second upper chamber; b2, second lower chamber;

12. mounting holes; 13. a first channel; 14. a second channel; 15. an input port; 16. an output port;

2. a nut; 21. a seal ring; 22. an annular inner plug; 23. a threaded sleeve; 24. an upper limit portion; 25. a lower limiting part;

3. a one-way valve; 31. a first check valve; 32. a second one-way valve;

4. a valve port; 41. a plane; 42. an annular projection; 421. a conical surface; 422. a transition arc surface;

5. a valve core; 51. a metal skeleton; 52. a vulcanized rubber member; 53. a concave surface;

6. a spring;

7. an adjustment mechanism; 71. a guide sleeve; 711. a convex ring; 72. adjusting the screw rod; 721. a limiting ring; 73. a seal ring;

8. a valve seat.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in fig. 2 to 10, the differential pressure valve provided in this embodiment includes a valve body 1 vertically disposed and having a valve cavity 11, two check valves 3 having the same structure and connected in parallel are disposed in the valve cavity 11, each check valve 3 includes a valve port 4 and a valve core 5 elastically abutting on an upper end face of the valve port 4, and a spring 6 abuts on an upper side of the valve core 5. The valve core 5 comprises a metal framework 51, a ring groove is arranged on the lower end face of the metal framework 51, and a vulcanized rubber piece 52 is embedded in the ring groove. The outer side of the upper end face of the valve port 4 is a plane 41, the inner side of the upper end face of the valve port 4 is convex upwards to form an annular bulge 42, and the vertical height of the annular bulge 42 is 0.6-1 mm. The annular protrusion 42 is disposed opposite to the lower end surface of the vulcanized rubber member, and the flat surface 41 is disposed opposite to the outer edge of the lower end surface of the metal framework 51.

The metal framework 51 is a cylindrical structure, the vulcanized rubber piece 52 is annular, and the vulcanized rubber piece is vulcanized in an annular groove of the metal framework 51 through a vulcanization process. Generally, for convenience of processing and installation, a valve seat 8 is arranged in the valve cavity 11, and an upper port of the valve seat 8 forms the valve port 4. In the initial state, the valve ports 4 of the two check valves 3 are kept closed under the pre-pressure of the spring 6. When the input pressure of one check valve 3 overcomes the pressure of the spring 6, the valve port 4 of the check valve 3 is opened, the check valve 3 transmits the air pressure to the inner cavity of the other check valve 3 until the differential pressure of the air springs at two sides is reduced to be lower than the theoretical differential pressure, and the differential pressure valve is closed again.

In the prior art, the theoretical pressure difference of the differential pressure valve is adjusted by adjusting the compression amount of the spring 6 by using an adjusting device, and the adjustment of the decrease of the action value of the differential pressure valve caused by the attenuation of the spring 6 is mainly responded to so as to ensure that the action value of the differential pressure valve can meet the application requirement of a vehicle. However, it has been found that the damping of the spring 6 is not the only factor causing the action value of the differential valve to be out of tolerance, and the aging of the vulcanized rubber member 52 of the valve element 5 is also a main factor causing the action value to be out of tolerance.

Because the spring force of the spring 6 is obviously attenuated after being applied for a period of time, the model selection design or the production quality of the spring 6 is proved to have problems, because the design parameters and the performance indexes of the spring 6 can be measured and controlled at any time, for example, the spring diameter, the free height, the screw pitch and the force values under different compression amounts of the spring 6 can be measured and controlled in real time through equipment such as calipers, spring tensioning machines and the like. However, the vulcanized rubber part 52 in the valve products has a small volume, and after being vulcanized to the metal framework 51, no matter the hardness, tensile strength, elongation at break, compression set, hot air aging test and the like, the quality control means in the production process is very limited, generally only appearance inspection and size inspection are carried out, and the size measurement in the size inspection process is larger due to the elasticity of the rubber. At present, in order to verify various indexes of the vulcanized rubber piece 52, only the rubber test block made of the same material is used for test verification, a quantitative control means in the production process is lacked, but the index verification of the rubber test block and the index of the vulcanized rubber piece 52 used in practice are in great difference. Therefore, based on the current design process level, the spring 6 can basically ensure the performance index and basically cannot be attenuated in the use process; the performance index of the vulcanized rubber piece 52 cannot be effectively guaranteed, and the vulcanized rubber piece is easy to deform or age and damage in the using process, so that the theoretical differential pressure of the differential pressure valve is directly reduced.

The factors that contribute to the susceptibility of the vulcanized rubber 52 to aging are two main factors: one is temperature and the other is pressure. For the temperature, the temperature is changed according to different running environments of the vehicle, and cannot be regulated and controlled manually; in the case of pressure, the aging of the vulcanized rubber member 52 is accelerated by a long time when the same position is subjected to a force for a long time. The aging of the vulcanized rubber 52 can be reduced by optimizing the design of the valve port 4.

When the differential valve port 4 is closed, an indentation is inevitably generated between the vulcanized rubber member 52 in the valve core 5 and the upper end surface of the valve port 4 by the spring 6. In order to ensure the sealing performance of the rubber, the indentation cannot be too deep, which easily causes accelerated aging of the vulcanized rubber piece 52, and meanwhile, in the opening process of the valve port 4, the too deep indentation can cause adhesion between the valve core 5 and the upper end surface of the valve port 4, which directly affects the action value of the differential pressure valve; especially, when the differential pressure valve is not operated before or after loading for a long time, the adhesion phenomenon is easier to exist between the upper end surface of the valve port 4 of the check valve 3 and the vulcanized rubber piece 52, so that the first opening value of the differential pressure valve is higher.

Along with the increase of the setting pressure value of the differential pressure valve (namely, the critical pressure value that can make valve port 4 open, also be the action value of theoretical pressure difference value or differential pressure valve), the precompression that is applied to spring 6 also constantly increases, the precompression of spring 6 leads to between the up end of vulcanite 52 and valve port 4 through case 5, when the precompression exceeded vulcanite 52 and bore the limit, valve port 4 can make the indentation of permanent deformation to vulcanite 52, along with the further increase of indentation degree of depth, the adhesion between vulcanite 52 of case 5 and valve port 4 influences the utility model discloses showing more, the compression capacity of spring 6 also changes, will influence the stability of differential pressure valve action value like this. In addition, as time goes by or the vulcanized rubber 52 is aged, the upper end surface of the valve port 4 damages the vulcanized rubber 52, and the sealing performance of the lower end surface of the vulcanized rubber 52 is lowered, affecting the airtightness of the differential pressure valve.

When the design of the valve port 4 is optimized, the indentation cannot be too shallow, which affects the air tightness of the differential pressure valve, especially in low-temperature tests, because the contraction of the vulcanized rubber piece 52 further causes the air tightness to be unqualified. And the lower end face of the vulcanized rubber piece 52 is difficult to ensure the smoothness due to the process reason, and the upper end face of the valve port 4 is completely flat, so that the sealing property is difficult to ensure. Researches show that the indentation of the vulcanized rubber piece 52 is controlled within 0.6-1 mm, so that the sealing performance can be ensured, and the aging of the vulcanized rubber piece 52 can be effectively prevented.

In this embodiment, the structures of the valve port 4 and the valve core 5 are optimized, so that the vulcanized rubber piece 52 can be protected to the greatest extent after the adjustment before leaving the factory, the indentation of the vulcanized rubber piece is controlled within a certain range, and the aging speed of the vulcanized rubber piece is slowed down, so that the action value of the differential pressure valve after loading is not out of tolerance. The method specifically comprises the following steps: the upper end surface of the valve port 4 is designed to have a flat surface 41 on the outer side and an annular protrusion 42 on the inner side. The annular protrusion 42 can well avoid the problem that the end surface of the vulcanized rubber piece 52 is uneven to affect the sealing performance. Meanwhile, the vulcanized rubber piece 52 is embedded in the metal framework 51 to form the valve core 5, and when the valve core 5 is under the pre-pressure action of the spring 6, the vulcanized rubber piece 52 can be ensured to be in sealing contact with the upper end surface of the valve port 4. Before loading, when the theoretical differential pressure of the differential pressure valve is adjusted manually, that is, when the compression amount of the spring 6 is further increased, after the pre-pressure of the spring 6 acting on the valve core 5 is further increased, the metal framework 51 of the valve core 5 and the upper end surface of the valve port 4 start to contact, at this time, the edge of the lower end surface of the metal framework 51 abuts against the plane 41 of the valve port 4, and the metal framework 51 has a certain protection effect on the vulcanized rubber piece 52, so that the vulcanized rubber piece 52 is prevented from being further extruded.

Therefore, the differential pressure valve in the embodiment can ensure that the vulcanized rubber piece 52 is in sealing contact with the valve port 4 and the sealing performance is ensured by specially designing the upper end surface of the valve port 4 and utilizing the protection effect of the metal framework 51 on the vulcanized rubber piece 52. Meanwhile, when the compression amount of the spring 6 is further increased, the metal framework 51 can abut against the plane 41 of the valve port 4, and the metal framework 51 mainly bears the force and can play a certain role in protecting the vulcanized rubber piece 52; because the height of annular protrusion 42 is limited to 0.6-1 mm, no matter how much force is applied to valve core 5 by spring 6, vulcanized rubber 52 can be prevented from being further compressed, and the compression amount of vulcanized rubber 52 can be controlled within a certain range, that is, the depth of the maximum indentation is controlled within 0.6-1 mm, so that the indentation is prevented from being too deep.

The sealing performance of the vulcanized rubber piece 52 can be guaranteed, the aging damage of the vulcanized rubber piece 52 is prevented or delayed to the maximum extent, the action value of the differential pressure valve after loading is guaranteed not to be out of tolerance, and the problem that the theoretical differential pressure of the differential pressure valve becomes small after long-time use is avoided to the maximum extent. Meanwhile, the adhesion phenomenon between the vulcanized rubber piece 52 and the valve port 4 can be well reduced, the damage to the vulcanized rubber piece 52 caused by frequent operation or misoperation in the value adjusting process of the differential pressure valve can be effectively avoided, and the reliability of the differential pressure valve is greatly improved.

In a specific implementation, the structure of the annular protrusion 42 can be implemented as follows: as shown in fig. 2 to 4, the outer wall of the annular protrusion 42 is a tapered surface 421 that tapers outward and upward (i.e., the tapered surface 421 is formed by the plane 41 of the annular protrusion 42 increasing in vertical height from the outside to the inside of the inner wall of the valve port 4), and a transition arc 422 is formed at the junction between the upper end edge of the tapered surface 421 and the inner wall of the annular protrusion 42.

Under the above structure, the size of the included angle θ between the conical surface 421 and the horizontal plane is selected according to the specific space size of the valve seat 8, and generally, the included angle θ can be selectively as large as possible under the condition that the vertical height of the annular protrusion 42 is within 0.6-1 mm, so as to effectively ensure the sealing effect. The radius of the transition arc surface 422 is preferably 0.2-0.5 mm. Of course, the annular protrusion 42 may have other structures according to the size requirement of the valve port 4, that is, the size requirement of the valve seat 8, and this embodiment is only for illustration.

In a possible implementation, the lower end face of the vulcanized rubber 52 protrudes beyond the lower end face of the metal skeleton 51 by a vertical height of preferably 0.1 mm. Because the flatness of the lower end face of the vulcanized rubber piece 52 is difficult to ensure during processing, the vulcanized rubber piece 52 protrudes out of the metal framework 51 for a certain length to serve as design redundancy during processing, and if the flatness of the vulcanized rubber piece 52 can be ensured or is not flat but has little influence on the performance in the later period, the vulcanized rubber piece 52 at the protruding part can be continuously retained; if the influence on the performance is large, the lower end face of the vulcanized rubber piece 52 can be ground by adopting a grinding process, so that the yield of the vulcanized rubber piece 52 is improved, and the cost is reduced.

Further, in order to facilitate adjustment of the theoretical differential pressure of the differential pressure valve before shipment or before loading, as shown in fig. 2, 5 and 6, each check valve 3 further includes an adjusting mechanism 7 provided on the valve body 1, and the adjusting mechanism 7 is connected to the spring 6 and can adjust the compression amount of the spring 6.

Specifically, in order to facilitate the adjustment mechanism 7 to adjust the compression amount of the spring 6, the adjustment mechanism 7 includes a guide sleeve 71 and an adjustment screw 72, the guide sleeve 71 is a cylindrical structure with a closed bottom and an open top, a convex ring 711 is formed on the outer side of the upper end of the guide sleeve 71 in an outward protruding manner, a concave surface 53 is formed on the outer edge of the upper end of the valve core 5, and two ends of the spring 6 respectively abut against the lower surface of the convex ring 711 and the concave surface 53. A threaded hole is opened in the valve body 1, the adjusting screw 72 is adjustably inserted in the threaded hole, and an end of the adjusting screw 72 abuts on an upper surface of a bottom of the guide sleeve 71.

The adjusting screw 72 is preferably connected with the threaded hole in a matched manner through fine threads, and the fine threads can control the value adjustment accuracy to the maximum extent. The tail end (i.e., the lower end) of the adjusting screw 72 abuts against the guide sleeve 71, the guide sleeve 71 can be controlled to move downwards by rotating the adjusting screw 72 downwards, the guide sleeve 71 is controlled to move upwards by rotating the adjusting screw 72 upwards, and the compression amount of the spring 6 is adjusted simply and conveniently. This adjustment mechanism 7 can be convenient carry out the value of dispatching from the factory to the differential pressure valve, of course, even after the differential pressure valve dispatches from the factory the loading, also can authorize user's quick adjustment adjusting screw 72's direction of rotation, and then the compression capacity of control spring 6 to the realization is to the quick adjustment of differential pressure valve action value. In order to ensure airtightness of the differential pressure valve, a seal ring 73 is interposed between the adjusting screw 72 and the threaded hole to perform seal protection.

Further, in order to facilitate processing and installation, a nut 2 is installed at the top of each one-way valve 3, the nut 2 is connected with the valve body 1 in a sealing mode, and a threaded hole is formed in the nut 2. It can be understood that a mounting hole 12 is formed in the valve body 1 at a position corresponding to the nut 2, the nut 2 is inserted into the mounting hole 12 and is in threaded connection, and a sealing ring 21 is clamped between the nut 2 and the mounting hole 12 to ensure the sealing performance. When the nut 2 is installed, corresponding torsion is applied to ensure looseness and separation prevention, and after the installation is completed, looseness-prevention marks are coated and marked between the nut 2 and the valve body 1.

Meanwhile, the inner surface of the top of the screw cap 2 can also play a role in limiting and protecting the upward movement of the guide sleeve 71. When the input pressure of the differential pressure valve is too high or the input pressure fluctuates frequently, the limiting function can ensure that the spring 6 acts in a limited range, the action value of the differential pressure valve is stable and reliable, and the input pressure of the differential pressure valve is stable. That is, after the input pressure of the input port of one check valve 3 of the differential pressure valve exceeds the pre-pressure of the spring 6, the valve port 4 is opened, along with the increase of the input pressure, the air pressure acts on the lower part of the valve core 5 of the check valve 3, and then the spring 6 acting on the valve core 5 drives the guide sleeve 71 to move upwards, after the guide sleeve 71 moves upwards to be in contact with the nut 2, the maximum stroke of the guide sleeve 71 is limited through the nut 2, even if the input pressure of the differential pressure valve continues to increase or fluctuate, the maximum opening degree of the valve port 4 cannot be increased any more, the constant pressure is ensured to be output, and the stability of the action value of the differential pressure valve. The maximum stroke distance of the guide sleeve 71 can be calculated according to the design size of the differential pressure valve and the normal working pressure. The limiting function can also effectively ensure that the compression amount of the spring 6 cannot exceed the theoretical design range, and the up-and-down fluctuation of the action value of the differential pressure valve is avoided.

In practical applications, in order to facilitate effective limit constraint on the adjusting screw 72 to ensure safe use, as shown in fig. 2 and 6, a limiting ring 721 is formed on the adjusting screw 72 and inside the nut 2 in an outward protruding manner, and the nut 2 is provided with an upper limiting portion 24 capable of limiting the upper end surface of the limiting ring 721 and a lower limiting portion 25 capable of limiting the lower end surface of the limiting ring 721.

The upper limit part 24 limits the limit ring 721, so that the situation that the nut 2 is screwed out due to misoperation when the adjusting screw 72 is adjusted by an operator can be avoided; under the extreme condition, the situation that the adjusting screw 72 is lost and left on a track line due to the fact that an operator seriously breaks down after loading the vehicle and adjusts the adjusting screw 72 privately until the adjusting screw 72 is separated from the guide sleeve 71, namely the spring 6 cannot restore the adjusting screw 72 after acting force cannot be exerted on the adjusting screw 72; and the potential safety hazard of the whole operation line caused by the loss of the adjusting screw 72 due to the fact that the adjusting screw 72 is separated from the nut 2 due to vibration during vehicle operation is also avoided.

Meanwhile, when the operator continuously screws the adjusting screw 72 into the nut 2, the spring 6 is continuously compressed, the limiting of the lower limiting part 25 on the adjusting screw 72 can be realized, the phenomenon that the pitch of the spring 6 is 0 and the spring 6 is pressed when the operator continuously screws the adjusting screw 72 downwards can be avoided, and the phenomenon that the continuously accumulated external force damages the vulcanized rubber piece 52 of the valve core 5 is avoided. When the adjusting screw 72 rotates downwards to a certain size, the adjusting screw cannot move downwards continuously due to the limiting effect, and the spring 6 and the vulcanized rubber piece 52 are further protected.

In detail, the nut 2 has a cylindrical structure with a downward opening, and an annular inner plug 22 is formed on the inner surface of the top of the nut 2 and extends downward. The periphery of the annular inner plug 22 is sleeved with a threaded sleeve 23, and the guide sleeve 71 is sleeved outside the threaded sleeve 23. The threaded sleeve 23 is of a cylindrical structure with an upward opening, a central hole is formed in the bottom of the threaded sleeve 23, the threaded hole, the annular inner plug 22 and the central hole are coaxially arranged, and the inner diameter of the annular inner plug 22 is larger than the aperture of the threaded hole and the aperture of the central hole. The annular portion of the top inner surface of the nut 2 between the threaded hole and the annular inner plug 22 constitutes an upper retainer 24, and the annular portion of the bottom inner surface of the nut 2 between the central hole and the annular inner plug 22 constitutes a lower retainer 25.

The inner wall of the screw sleeve 23 is generally in threaded connection with the outer wall of the annular inner plug 22, the upper end face of the screw sleeve 23 preferably abuts against the top inner wall of the screw cap 2, the two are in full contact, and the screw sleeve 23 can also play a role in guiding the up-and-down movement of the guide sleeve 71. The up-down stroke of the adjusting screw rod 72 can be limited through the matching of the screw sleeve 23 and the annular inner plug 22, and the adjusting screw rod is simple and convenient. Of course, the upper and lower limits of the adjusting screw 72 may also be in other structural forms, and this embodiment is only for illustration.

More preferably, the inner wall of the guide sleeve 71 is a clearance fit with the outer wall of the nut 2. When the spool 5 of the differential pressure valve is actuated, a force is transmitted to the guide sleeve 71 through the spring 6 fitted to the spool 5. When the differential pressure valve inputs pressure fluctuation or the natural frequency of the support vibration of the differential pressure valve is close to the vibration frequency of the spring 6 in the vehicle operation process, through the clearance fit between the guide sleeve 71 and the threaded sleeve 23, the damping generated in the moving process of the guide sleeve 71 on the threaded sleeve 23 can effectively reduce or inhibit the frequency jump and the vibration of the valve core 5, and the differential pressure valve is prevented from generating irregular abnormal sound in the working process.

Further, the two check valves 3 are connected in reverse parallel, as shown in fig. 2 and fig. 7 to 10, the two check valves 3 are respectively referred to as a first check valve 31 and a second check valve 32, the valve chamber 11 includes a first valve chamber a and a second valve chamber B, and the first check valve 31 and the second check valve 32 are respectively disposed in the first valve chamber a and the second valve chamber B. Port 4 of first check valve 31 divides first valve chamber a into first upper chamber a1 and first lower chamber a2, and port 4 of second check valve 32 divides second valve chamber B into second upper chamber B1 and second lower chamber B2. The first upper chamber a1 communicates with the second lower chamber B2 through the first passage 13, the first lower chamber a2 communicates with the second upper chamber B1 through the second passage 14, and an input port 15 communicating with the first lower chamber a2 and an output port 16 communicating with the second lower chamber B2 are opened at a side portion of the valve body 1.

When in use, the input port 15 and the output port 16 are respectively communicated with the left air spring and the right air spring on two sides of the same bogie. Since the second upper chamber B1 and the first lower chamber a2 are always open, the pressure in the first lower chamber a2 decreases as the pressure in the left air spring connected to the input port 15 decreases, and the pressure in the second upper chamber B1 decreases. When the reduced pressure exceeds the predetermined pressure, the pressure in the second lower chamber B2 overcomes the spring force of the spring 6 in the second check valve 32, opens the port 4 of the second check valve 32, and allows the pressure in the second lower chamber B2 to enter the second upper chamber B1 through the port 4 and further enter the first lower chamber a2, and the direction of the air flow is shown by the arrow in the valve chamber 11 in fig. 10. When the pressure difference between the second lower chamber B2 and the second upper chamber B1 meets the design requirement, the valve port 4 of the second check valve 32 is restored to be closed under the spring force of the spring 6 in the second check valve 32, and the second lower chamber B2 no longer replenishes the second upper chamber B1 with air.

Conversely, when the pressure of the right air spring connected to the output port 16 decreases, the left air spring connected to the first lower chamber a2 will supply air to the right air spring connected to the second lower chamber B2 until the pressure difference meets the design requirements.

Further, in order to prevent foreign matter in the piping from entering the valve body 1, filter members (not shown in the drawings) are provided at both the inlet port 15 and the outlet port 16. The filter piece can adopt a filter screen or a filter element to play a role in protection, prevent foreign matters from influencing the action performance of the valve after entering the valve body 1 and simultaneously avoid the foreign matters from being adhered to the valve port 4 to influence the air tightness when the valve is closed.

In summary, in the differential pressure valve in this embodiment, the annular convex ring 711 is formed on the upper end surface of the valve port 4, the vertical height of the annular convex ring 711 is limited, and the metal framework 51 is used for protecting the vulcanized rubber piece 52, so that the maximum indentation of the vulcanized rubber piece 52 can be effectively controlled within 0.6-1 mm, the indentation is prevented from being too deep, and the sealing performance can be ensured. Meanwhile, the inner surface of the top of the nut 2 is used for limiting the upward movement of the guide sleeve 71, so that the spring 6 can be ensured to act in a limited range; the upper limiting part 24 and the lower limiting part 25 are used for limiting the stroke of the adjusting screw 72, so that the vulcanized rubber piece 52 is further protected, the vulcanized rubber piece 52 can be protected to the greatest extent after the adjustment before leaving the factory, the aging speed of the vulcanized rubber piece is reduced, and the action value of the differential pressure valve after loading is not out of tolerance. The whole differential pressure valve has the advantages of simple structure, adjustable flow, stable and reliable performance, good protective performance and convenient maintenance.

The above are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims (12)

1. A differential pressure valve comprises a valve body which is vertically arranged and is provided with a valve cavity, two check valves which have the same structure and are communicated in parallel are arranged in the valve cavity, each check valve comprises a valve port and a valve core which can be elastically abutted against the upper end surface of the valve port, a spring is abutted against the upper part of the valve core, the differential pressure valve is characterized in that,

the valve core comprises a metal framework, a ring groove is formed in the lower end face of the metal framework, and a vulcanized rubber piece is embedded in the ring groove; the outer side of the upper end face of the valve port is a plane, the inner side of the upper end face of the valve port is convex upwards to form an annular bulge, and the vertical height of the annular bulge is 0.6-1 mm; the annular bulge is arranged right opposite to the lower end face of the vulcanized rubber piece, and the plane is arranged right opposite to the outer edge of the lower end face of the metal framework.

2. A differential pressure valve as claimed in claim 1,

the outer wall of the annular bulge is a conical surface with an upward tapered outer diameter, and a transition arc surface is formed at the joint between the edge of the upper end of the conical surface and the inner wall of the annular bulge.

3. A differential pressure valve as claimed in claim 1,

the lower end face of the vulcanized rubber piece extends out of the lower end face of the metal framework, and the vertical height of the extension is 0.1 mm.

4. A differential pressure valve as claimed in claim 1,

each check valve still including establish adjustment mechanism on the valve body, adjustment mechanism with the spring coupling can adjust the compression capacity of spring.

5. A differential pressure valve as claimed in claim 4,

the adjusting mechanism comprises a guide sleeve and an adjusting screw rod, the guide sleeve is of a cylindrical structure with a closed bottom and an open top, the outer side of the upper end of the guide sleeve is outwards protruded to form a convex ring, the outer edge of the upper end of the valve core is provided with a concave surface, and two ends of the spring respectively prop against the lower surface of the convex ring and the concave surface;

the valve body is provided with a threaded hole, the adjusting screw rod can be inserted into the threaded hole in an adjustable mode, and the end portion of the adjusting screw rod abuts against the upper surface of the bottom of the guide sleeve.

6. A differential pressure valve as claimed in claim 5,

and a sealing ring is clamped between the adjusting screw rod and the threaded hole.

7. A differential pressure valve as claimed in claim 5,

every the nut is all installed at the top of check valve, the nut with valve body sealing connection, the screw hole is seted up on the nut.

8. A differential pressure valve as claimed in claim 7,

the adjusting screw is arranged on the adjusting screw and positioned in the nut, a limiting ring is formed by outward protruding arrangement, and the nut is provided with an upper limiting part capable of limiting the upper end face of the limiting ring and a lower limiting part capable of limiting the lower end face of the limiting ring.

9. A differential pressure valve as defined in claim 8,

the nut is of a cylindrical structure with a downward opening, and an annular inner plug is formed by downwardly extending the inner surface of the top of the nut; a threaded sleeve is sleeved on the periphery of the annular inner plug, and the guide sleeve is sleeved on the outer side of the threaded sleeve;

the threaded sleeve is of a cylindrical structure with an upward opening, a central hole is formed in the bottom of the threaded sleeve, the threaded hole, the annular inner plug and the central hole are coaxially arranged, and the inner diameter of the annular inner plug is larger than the aperture of the threaded hole and the aperture of the central hole; the annular part of the inner surface of the top of the nut and located between the threaded hole and the annular inner plug forms the upper limit part, and the annular part of the inner surface of the bottom of the nut and located between the central hole and the annular inner plug forms the lower limit part.

10. A differential pressure valve as claimed in claim 9,

the inner wall of the guide sleeve is in clearance fit with the outer wall of the screw cap.

11. A differential pressure valve as claimed in claim 1,

the two check valves are respectively marked as a first check valve and a second check valve, the valve cavity comprises a first valve cavity and a second valve cavity, and the first check valve and the second check valve are respectively arranged in the first valve cavity and the second valve cavity; the valve port of the first check valve divides the first valve cavity into a first upper chamber and a first lower chamber, and the valve port of the second check valve divides the second valve cavity into a second upper chamber and a second lower chamber;

the first upper chamber is communicated with the second lower chamber through a first channel, the first lower chamber is communicated with the second upper chamber through a second channel, and an input port communicated with the first lower chamber and an output port communicated with the second lower chamber are formed in the side portion of the valve body.

12. A differential pressure valve as defined in claim 11,

and filter pieces are arranged at the input port and the output port.

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