Overflow valve for urban rail vehicle pneumatic control system

Abstract

The overflow valve for urban rail vehicle pneumatic control system comprises an upper valve body, a flow distribution plate and a lower valve body, the upper valve body is provided with a downwardly open mounting hole, the flow distribution plate is located between the upper valve body and the lower valve body, the flow distribution plate is provided with a plurality of flow distribution grooves in the circumference, the lower valve body is annularly provided with an annular cavity, the lower ends of the plurality of flow distribution grooves are connected to the annular cavity, the upper end surface of the flow distribution plate is provided with a diaphragm, the bottom of the mounting hole is provided with an upper spring support, the lower valve body is provided with an input cavity on one side, the input cavity is communicated with the annular cavity, the lower valve body is provided with an output cavity in the vertical direction, and the output cavity extends to the lower surface of the diaphragm. The diaphragm can be prevented from being unevenly stressed, tilted and even stuck under the action of air pressure, the opening and closing pressure stability of the overflow valve is improved, and the technical index requirements of safe, reliable and stable operation under various environmental conditions are met.

Description

Technical Field

[0001] This invention relates to the field of direct-acting diaphragm overflow valve technology, and particularly to overflow valves used in the pneumatic control system of urban rail vehicles. Background Technology

[0002] Currently, the direct-acting diaphragm overflow valve used in the air spring pneumatic control system of my country's rail transit vehicles has the following structure: Figure 1 As shown, the product consists of components such as adjusting bolt 1′, upper spring bracket 2′, spring 3′, lower spring bracket 4′, diaphragm assembly 5′, lower housing 6′, connecting screw 7′, and upper housing 8′. The upper housing 8′ and lower housing 6′ are fastened together using connecting screw 7′. By adjusting the screw's screw length, spring 3′ generates appropriate elastic force. This force acts on diaphragm assembly 5′ through lower spring bracket 4′, pressing diaphragm assembly 5′ tightly against the air inlet valve of lower housing 6′, disconnecting input chamber a from output chamber b. When air pressure is input into input chamber a, this pressure overcomes the elastic force of spring 3′ and the tension of diaphragm assembly 5′, pushing diaphragm assembly 5′ upward, opening the air inlet valve, and connecting input chamber a to output chamber b. The air pressure in input chamber a when output chamber b begins to output air pressure is the opening pressure. The stability of this pressure is a key performance indicator of the product. Because the product lacks a diversion device, the input cavity a of the diaphragm assembly 5′ near the lower housing 6′ is the first to be subjected to air pressure impact, making it prone to tilting. This causes friction, or even jamming, between the outer circle of the lower spring bracket 4′ and the inner hole of the upper housing 8′. Furthermore, because the fit between the spring 3′ and the upper spring bracket 2′ and lower spring bracket 4′ is a clearance fit of approximately 1mm, after the product is installed in the vehicle, the coaxiality between the adjusting bolt 1′, upper spring bracket 2′, spring 3′, lower spring bracket 4′, and diaphragm assembly 5′ can change by up to approximately 1mm due to vehicle vibration. Affected by these two factors, the opening pressure of the product is prone to large fluctuations, or even jamming, causing the product to fail to meet the increasingly stringent technical requirements of rail transit vehicles. Summary of the Invention

[0003] The purpose of this invention is to propose an overflow valve for the pneumatic control system of urban rail vehicles, which reduces or avoids uneven stress on the diaphragm under air pressure, resulting in tilting or even jamming, and improves the opening and closing pressure stability of the overflow valve, so as to meet the technical requirements of safe, reliable and stable operation of rail transit vehicles under various environmental conditions.

[0004] To achieve the above objectives, the following technical solution is adopted: an overflow valve for the pneumatic control system of urban rail vehicles, comprising an upper valve body, a flow divider plate, and a lower valve body. The upper valve body has a downward-opening mounting hole. The flow divider plate is located between the upper and lower valve bodies. The flow divider plate has multiple flow divider grooves arranged circumferentially. The lower valve body has an annular cavity arranged on its upper ring. The lower ends of the multiple flow divider grooves are connected to the annular cavity. A diaphragm is arranged on the upper surface of the flow divider plate. The upper openings of the multiple flow divider grooves act evenly on the diaphragm. An upper spring bracket is installed at the bottom of the mounting hole. A spring is connected below the upper spring bracket. A lower spring bracket is connected to the opening of the mounting hole. The lower end of the spring abuts against the lower spring bracket, and the lower spring bracket is located above the diaphragm. An input cavity is arranged on one side of the lower valve body, which communicates with the annular cavity. An output cavity is arranged vertically at the center of the lower valve body. The upper end of the output cavity extends through the flow divider plate to the lower surface of the diaphragm.

[0005] Preferably, the upper valve body is provided with an adjusting bolt, the movable end of which extends into the mounting hole and abuts against the upper spring bracket.

[0006] Preferably, the upper spring bracket has an upward-opening conical opening, in which a steel ball is installed, and the movable end of the adjusting bolt extends into the conical opening and abuts against the steel ball.

[0007] Preferably, the adjusting bolt is provided with a vent hole that communicates with the outside.

[0008] Preferably, a locking nut is connected to the adjusting bolt, and the locking nut is located on the upper end face of the upper valve body.

[0009] Preferably, the flow divider plate is further provided with annular ribs, which are located above the flow divider groove.

[0010] Preferably, the mounting hole is a stepped hole structure, and the lower spring bracket is located within the stepped hole structure and can move up and down to a predetermined height.

[0011] Preferably, the lower spring bracket has a positioning cylinder extending into the mounting hole, the upper end of the positioning cylinder extending into the mounting hole by a predetermined distance, and an oilless sliding bearing is provided between the positioning cylinder and the inner wall of the mounting hole.

[0012] Preferably, the upper spring bracket and the mounting hole of the upper valve body are clearance fit, the lower spring bracket and the oilless sliding bearing are clearance fit, and the opposite end faces of the upper spring bracket and the lower spring bracket have intermediate bosses, and the intermediate bosses are transition fits with the inner hole of the spring.

[0013] Preferably, the flow divider plate is further provided with a conical groove, which is located inside the annular rib and is arranged in a ring on the upper surface of the flow divider plate. A sealing gasket is provided between the lower valve body and the flow divider plate.

[0014] Preferably, both the output cavity and the input cavity are provided with filter screen assemblies. The filter screen assembly includes a ring-shaped filter screen support and a stainless steel wire filter screen located inside the filter screen support. The upper and lower surfaces of the filter screen support are both ring-shaped with arc-shaped sealing surfaces.

[0015] Preferably, the upper valve body, the flow divider, and the lower valve body are connected by washers and hexagonal head screws.

[0016] The beneficial effects achieved by this invention are as follows:

[0017] The overflow valve for the pneumatic control system of urban rail vehicles provided by this invention, by setting multiple diversion grooves, reduces or avoids uneven stress on the diaphragm under air pressure, resulting in tilting or even jamming, thereby improving the stability of the opening and closing pressure of the overflow valve. This meets the technical requirements for safe, reliable, and stable operation of rail transit vehicles under various environmental conditions. Simultaneously, it has a good limiting design structure, strong vibration resistance, and can achieve an opening pressure fluctuation of less than 20 kPa during vehicle operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overflow valve structure in the background art.

[0019] Figure 2 This is a schematic diagram of the overflow valve structure used in the air circuit control system of urban rail vehicles according to the present invention.

[0020] Figure 3 This is a top view of the structure of the present invention.

[0021] Figure 4 This is a schematic diagram of the connection structure of the upper valve body, the flow divider plate, and the lower valve body of the present invention.

[0022] Figure 5 This is a top view of the splitter structure.

[0023] Figure 6 This is a schematic diagram of the internal cross-sectional structure of the manifold.

[0024] Figure 7 This is a schematic diagram of the adjusting bolt structure.

[0025] Figure 8 This is a schematic diagram of the sealing gasket structure.

[0026] Figure 9 This is a schematic diagram of the filter assembly structure. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] See appendix Figure 1-9 An overflow valve for a pneumatic control system of urban rail vehicles includes an upper valve body 1, a flow divider plate 2, and a lower valve body 3. The upper valve body 1 has a downward-opening mounting hole 4. The flow divider plate 2 is located between the upper valve body 1 and the lower valve body 3. The flow divider plate 2 has multiple flow divider grooves 5 arranged circumferentially. The lower valve body 3 has an annular cavity 6 arranged on its upper ring. The lower ends of the multiple flow divider grooves 5 are connected to the annular cavity 6. A diaphragm 7 is provided on the upper surface of the flow divider plate 2. The upper openings of the multiple flow divider grooves 5 act evenly on the diaphragm 7. An upper spring bracket 8 is installed at the bottom of the mounting hole 4. A spring 9 is connected below the upper spring bracket 8. A lower spring bracket 10 is connected to the opening of the mounting hole 4. The lower end of the spring 9 abuts against… The lower valve body 3 rests on the lower spring support 10, which is located above the diaphragm 7. An input chamber 11 is provided on one side of the lower valve body 3, which is connected to the annular chamber 6. An output chamber 12 is provided in the center of the lower valve body 3 along the vertical direction. The upper end of the output chamber 12 extends through the diverter plate 2 to the lower surface of the diaphragm 7. During use, the air pressure of the product input chamber 11 is applied to the diaphragm 7 through multiple evenly distributed diverter grooves 5, so that the bottom of the lower spring support 10 is evenly stressed, avoiding tilting or jamming during the up-and-down reciprocating motion. This improves the opening and closing pressure stability of the overflow valve and meets the technical requirements for safe, reliable and stable operation of rail transit vehicles under various environmental conditions.

[0030] In this embodiment, an adjusting bolt 13 is provided on the upper valve body 1. The movable end of the adjusting bolt 13 extends into the mounting hole 4 and abuts against the upper spring bracket 8 to adjust the height position of the upper spring bracket 8, thereby adjusting the elasticity characteristics of the spring 9.

[0031] In this embodiment, the upper spring bracket 8 has an upward-opening conical opening, and a steel ball 14 is installed inside the conical opening. The movable end of the adjusting bolt 13 extends into the conical opening and abuts against the steel ball 14. By utilizing the self-centering characteristic of the steel ball 14, it is ensured that the force of the adjusting bolt 13 always acts vertically on the center position of the upper spring bracket 8 and is vertically transmitted to the spring 9.

[0032] In this embodiment, the adjusting bolt 13 is provided with a breathing hole 14 that communicates with the outside, so that the upper cavity of the diaphragm is connected with the outside atmosphere. During the operation of the overflow valve, there is no air pressure resistance and the opening and closing characteristics are stable.

[0033] In this embodiment, a locking nut 15 is connected to the adjusting bolt 13. The locking nut 15 is located on the upper end face of the upper valve body 1, ensuring that after the adjusting bolt 13 is screwed into the threaded hole of the upper valve body 1, the position of the adjusting bolt 13 is fixed by tightening the locking nut 15.

[0034] In this embodiment, the flow divider 2 is also provided with annular ribs 16, which are located above the flow divider 5. Under the blocking effect of the annular ribs 16, the axial deformation of the diaphragm 7 can be reasonably controlled, thereby enabling precise control of the product's opening pressure.

[0035] In this embodiment, the mounting hole 4 is a stepped hole structure. The lower spring bracket 10 is located within the stepped hole structure and can move up and down to a predetermined height, thereby controlling and limiting the maximum movement distance of the lower spring bracket 10 and preventing overload during the operation of the spring 9.

[0036] In this embodiment, the lower spring bracket 10 has a positioning cylinder 17 extending into the mounting hole 4. The upper end of the positioning cylinder 17 extends into the mounting hole 4 by a predetermined distance, further preventing the lower spring bracket 10 from tilting or jamming. An oilless sliding bearing 18 is provided between the positioning cylinder 17 and the inner wall of the mounting hole 4. An oilless sliding bearing 18 is designed in the mounting hole 4 of the upper valve body 1. Based on the fact that the form and position tolerance and dimensions of the inner hole are highly accurate after the oilless sliding bearing 18 is press-fitted, coupled with the self-lubricating characteristics of the oilless sliding bearing 18, the lower spring bracket 10 has excellent working stability.

[0037] In this embodiment, the upper spring bracket 8 and the mounting hole 4 of the upper valve body 1 are clearance fit, and the lower spring bracket 10 and the oilless sliding bearing 18 are clearance fit. This ensures that under vibration conditions, the maximum change in coaxiality between the steel ball 14, the upper spring bracket 8, the spring 9, and the lower spring bracket 10 is less than 0.1mm, thereby reducing the elasticity fluctuation of the spring 9. The opposite end faces of the upper spring bracket 8 and the lower spring bracket 10 have intermediate bosses, and the intermediate bosses are all transition fits with the inner hole of the spring 9. This ensures that the relative position of the spring 9 and the upper spring bracket 8 and the lower spring bracket 10 does not move radially under impact vibration conditions, thereby ensuring that the coaxiality of the spring 9 and the upper spring bracket 8 and the lower spring bracket 10 remains unchanged. The appropriate clearance design results in a high first-time assembly qualification rate, reduces rework time and scrap losses during the production process, and lowers production costs.

[0038] In this embodiment, the diverter plate 2 is also provided with a conical groove 19. The conical groove 19 is located inside the annular rib 16 and is arranged in a ring on the upper end face of the diverter plate 2. The angle of the conical groove 19 is reasonably designed according to the hardness of the adhesive of the diaphragm 7 to ensure the reliable sealing of the product. A sealing gasket 20 is provided between the lower valve body 3 and the diverter plate 2 to ensure the sealing between the lower valve body 3 and the diverter plate 2.

[0039] In this embodiment, both the output cavity 12 and the input cavity 11 are provided with filter screen assemblies. The filter screen assembly includes a ring-shaped filter screen support 21 and a stainless steel wire filter screen 22 located inside the filter screen support 21. The upper and lower surfaces of the filter screen support 21 are both provided with arc-shaped sealing surfaces M, which gives it good sealing performance and anti-pollution ability.

[0040] The upper valve body 1, the flow divider plate 2, and the lower valve body 3 are connected by washers 23 and hexagon socket head cap screws 24. The flow divider groove 5 includes, but is not limited to, the oblong hole shown in the figure, and should also include circular holes, rectangular holes, etc.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An overflow valve for a pneumatic control system of urban rail vehicles, comprising an upper valve body (1), a flow divider (2), and a lower valve body (3), characterized in that: The upper valve body (1) has a downward-opening mounting hole (4). The flow divider (2) is located between the upper valve body (1) and the lower valve body (3). The flow divider (2) has multiple flow divider grooves (5) arranged around its circumference. The lower valve body (3) has an annular cavity (6) arranged on its upper ring. The lower ends of the multiple flow divider grooves (5) are connected to the annular cavity (6). A diaphragm (7) is arranged on the upper end face of the flow divider (2). The upper end slots of the multiple flow divider grooves (5) act evenly on the diaphragm (7). An upper spring bracket (8) is installed at the bottom of the mounting hole (4). A spring (9) is connected below the upper spring bracket (8), and a lower spring bracket (10) is connected to the opening of the mounting hole (4). The lower end of the spring (9) abuts against the lower spring bracket (10), and the lower spring bracket (10) is located above the diaphragm (7). An input chamber (11) is provided on one side of the lower valve body (3), and the input chamber (11) is connected to the annular cavity (6). An output chamber (12) is provided in the center of the lower valve body (3) along the vertical direction. The upper end of the output chamber (12) extends through the diverter plate (2) to the lower surface of the diaphragm (7).

2. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 1, characterized in that: An adjusting bolt (13) is provided on the upper valve body (1), and the movable end of the adjusting bolt (13) extends into the mounting hole (4) and abuts against the upper spring bracket (8).

3. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 2, characterized in that: The upper spring bracket (8) has an upward-opening conical opening, in which a steel ball (14) is installed, and the movable end of the adjusting bolt (13) extends into the conical opening and abuts against the steel ball (14).

4. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 2, characterized in that: The adjusting bolt (13) is provided with a vent hole that communicates with the outside.

5. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 2, characterized in that: A locking nut (15) is connected to the adjusting bolt (13), and the locking nut (15) is located on the upper end face of the upper valve body (1).

6. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 1, characterized in that: The flow divider plate (2) is also provided with annular ribs (16), which are located above the flow divider groove (5).

7. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 1, characterized in that: The mounting hole (4) is a stepped hole structure, and the lower spring bracket (10) is located inside the stepped hole structure and can move up and down to a predetermined height.

8. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 1, characterized in that: The lower spring bracket (10) has a positioning cylinder (17) extending into the mounting hole (4). The upper end of the positioning cylinder (17) extends into the mounting hole (4) by a predetermined distance. An oilless sliding bearing (18) is provided between the positioning cylinder (17) and the inner wall of the mounting hole (4).

9. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 8, characterized in that: The mounting hole (4) of the upper spring bracket (8) and the upper valve body (1) is a clearance fit, and the fit between the lower spring bracket (10) and the oilless sliding bearing (18) is a clearance fit. The opposite end faces of the upper spring bracket (8) and the lower spring bracket (10) have intermediate bosses, and the intermediate bosses are all transition fits with the inner hole of the spring (9).

10. The overflow valve for the pneumatic control system of urban rail vehicles according to claim 1, characterized in that: The flow divider (2) is also provided with a conical groove (19), which is located inside the annular rib (16) and is arranged in a ring on the upper end face of the flow divider (2). A sealing gasket (20) is provided between the lower valve body (3) and the flow divider (2).

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