Pressure reducing valve

Abstract

The application discloses a pressure reducing valve, which comprises a valve body, a diaphragm and a valve core, the valve body is internally provided with a medium inflow channel, a medium outflow channel, a valve core cavity, a valve seat cavity and an outlet cavity, the valve seat cavity is internally fixedly installed with a valve seat, the upper end of the diaphragm is provided with an elastic pressing assembly for pressing the diaphragm downwards to adhere to the valve seat, the valve seat is provided with a central channel, the upper end of the valve core passes through the central channel of the valve seat and abuts against or is connected to the diaphragm, the valve body is internally provided with a small spring, the middle of the diaphragm is provided with a flat part, the elastic pressing assembly comprises a pressing plate abutting against the flat part of the diaphragm and a first elastic member acting on the pressing plate, the lower end of the pressing plate is provided with a downward protruding lower protruding part, the lower protruding part is provided with a middle flat surface and an arc surface arranged at the outer periphery of the middle flat surface, the radius of the arc surface of the lower protruding part is R, the height between the flat part of the diaphragm and the valve seat when the diaphragm is not subjected to the force of the elastic pressing assembly is H, and 0.045<=H / R<=0.055, so that the service life of the diaphragm is effectively prolonged.

Description

Technical Field

[0001] This invention relates to the technical field of valves, and particularly to a pressure reducing valve. Background Technology

[0002] A pressure reducing valve is a pressure regulating device in a pneumatic system. It includes a valve body, a diaphragm, and a valve core. The valve body has a medium inflow channel, a medium outflow channel, a valve core cavity, a valve seat cavity, and an outlet cavity. A valve seat is fixedly installed in the valve seat cavity. The diaphragm is located in the outlet cavity, and its outer periphery is pressed against the diaphragm sealing surface of the valve body. A pressing assembly is provided at the upper end of the diaphragm to press the diaphragm down to fit the valve seat. The valve seat has a central channel, and the lower end of the central channel forms a valve port. The valve core is axially slidably located in the valve core cavity. The upper end of the valve core passes through the central channel of the valve seat and abuts against or connects to the diaphragm. A small spring is provided in the valve body to push the valve core upward. In the initial state, the force exerted by the pressing assembly on the diaphragm is greater than the force exerted by the valve core on the diaphragm.

[0003] When the pressure reducing valve is working, the diaphragm is pressed against the valve seat by the pressing assembly. After the fluid medium is introduced into the medium inflow channel, the fluid pressure acting on the lower end face of the diaphragm will push the diaphragm upward until the pressure acting on the upper end face of the diaphragm and the thrust acting on the lower end face of the diaphragm reach a dynamic balance. When the fluid pressure in the outlet of the lower end of the diaphragm increases, the fluid thrust acting on the diaphragm is greater than the pressure acting on the upper end face of the diaphragm, causing the diaphragm to move upward. At this time, the valve core moves upward under the action of the small spring, which reduces the valve opening, increases the throttling effect, and thus reduces the output pressure, establishes a new dynamic balance, until the valve opening is closed.

[0004] In pressure reducing valves, the diaphragm deforms significantly with each opening and closing operation, so the durability and service life of the diaphragm are technical issues that require special attention. Summary of the Invention

[0005] The purpose of this invention is to provide a pressure reducing valve that, by ensuring that the ratio of the height H of the flat portion of the diaphragm to the radius R of the arcuate surface of the lower convex portion of the diaphragm is between 0.045 and 0.055 when the diaphragm is not subjected to the force of the elastic pressing component, the stress between the diaphragm and the pressure plate is uniform in both the initial and final contact states, thereby preventing excessive localized stress on the diaphragm and effectively improving the service life of the diaphragm.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a pressure reducing valve, comprising a valve body, a diaphragm, and a valve core, wherein the valve body is provided with a medium inflow channel, a medium outflow channel, a valve core cavity, a valve seat cavity, and an outlet cavity; a valve seat is fixedly installed in the valve seat cavity; the diaphragm is disposed in the outlet cavity and its outer periphery is pressed against the diaphragm sealing surface of the valve body; an elastic pressing component is provided at the upper end of the diaphragm for pressing the diaphragm down to fit the valve seat; the valve seat is provided with a central channel, the lower end of which forms a valve port; the valve core is axially slidably disposed in the valve core cavity, and the upper end of the valve core passes through the valve seat cavity. The valve seat has a central channel that abuts against or connects to the diaphragm. The valve body is equipped with a small spring for pushing the valve core upward. The diaphragm has a flat portion in the middle. The elastic pressing assembly includes a pressure plate abutting against the flat portion of the diaphragm and a first elastic element acting on the pressure plate. The lower end of the pressure plate has a downwardly protruding lower convex portion. The lower convex portion has a central flat surface and an arc-shaped surface disposed on the outer periphery of the central flat surface. The radius of the arc-shaped surface of the lower convex portion is R. When the diaphragm is not subjected to the force of the elastic pressing assembly, the height between the flat portion of the diaphragm and the valve seat is H, where 0.045≤H / R≤0.055.

[0007] Furthermore, the flat portion of the diaphragm covers the lower protrusion of the pressure plate.

[0008] Furthermore, when the diaphragm abuts against the upper surface of the valve seat under the action of the elastic pressing assembly, the middle flat surface and the arc-shaped surface of the pressure plate both fit against the upper surface of the flat portion of the diaphragm.

[0009] Furthermore, the flat surface of the pressure plate is located in the upper end face area of ​​the valve seat, the arc-shaped surface of the pressure plate is located in the upper end face area of ​​the valve seat, and the arc-shaped surface of the pressure plate is located outside the upper end face area of ​​the valve seat.

[0010] Furthermore, where 0.9mm≤H≤1.1mm.

[0011] Furthermore, the valve body is provided with a pressure regulating component, which includes a pressure block and a connecting handle. The connecting handle is rotatably connected to the valve body. The pressure block is located at the lower end of the connecting handle and inside the valve body. The first elastic element is abutted between the pressure block and the pressure plate. The pressure of the elastic pressing component acting on the diaphragm is adjusted by adjusting the position of the pressure block through the connecting handle.

[0012] Furthermore, the upper end of the diaphragm is provided with a central positioning post, and the diaphragm is provided with an annular groove on the outer periphery of the central positioning post. The first elastic element is partially accommodated in the annular groove and sleeved on the outer periphery of the central positioning post.

[0013] Furthermore, the valve body includes a first valve body, a second valve body, and a connecting sleeve for connecting the first valve body and the second valve body, wherein the connecting end of the first valve body and the second valve body is provided with a diaphragm sealing surface.

[0014] Furthermore, the valve body is provided with a limiting step, which limits the highest upward movement position of the pressure plate by limiting the upper end face of the outer periphery of the pressure plate with the limiting step.

[0015] In summary, the present invention has the following beneficial effects:

[0016] The pressure reducing valve of the present invention ensures that the stress between the diaphragm and the pressure plate is uniform in both the initial and final contact states by keeping the ratio of the height H of the flat portion of the diaphragm to the radius R of the arcuate surface of the lower convex portion of the diaphragm between 0.045 and 0.055 when the diaphragm is not subjected to the force of the elastic pressing component. This prevents excessive local stress on the diaphragm and effectively improves the service life of the diaphragm. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the present invention when the diaphragm is not pressed onto the valve seat by the pressure plate.

[0019] Figure 3 This is a schematic diagram of the structure of the diaphragm of the present invention when it is pressed onto the valve seat by the pressure plate.

[0020] Figure 4 This is a schematic diagram of the structure of the pressure plate of the present invention.

[0021] In the diagram: 10. Valve body; 11. Medium inflow channel; 12. Medium outflow channel; 13. Valve core cavity; 14. Valve seat cavity; 15. Outlet cavity; 16. First valve body; 17. Second valve body; 171. Limiting step; 18. Connecting sleeve; 19. Diaphragm sealing surface; 20. Diaphragm; 21. Flat part; 30. Valve core component; 40. Valve seat; 41. Valve plate; 50. Elastic pressing assembly; 51. Pressure plate; 511. Lower protrusion; 512. Flat surface; 513. Arc-shaped surface; 52. First elastic element; 60. Small spring; 70. Pressure regulating assembly; 71. Pressure block; 72. Connecting handle. Detailed Implementation

[0022] The invention will now be further described with reference to the accompanying drawings.

[0023] like Figures 1-4As shown, a pressure reducing valve includes a valve body 10, a diaphragm 20, and a valve core 30. The valve body 10 is provided with a medium inflow channel 11, a medium outflow channel 12, a valve core cavity 13, a valve seat cavity 14, and an outlet cavity 15. The outlet cavity 15 is directly connected to the medium outflow channel 12 on one side, and is connected to the medium inflow channel 11 through the valve seat cavity 14 and the valve core cavity 13 on the other side. After the medium enters from the medium inflow channel 11, it will pass through the valve core cavity 13, the valve seat cavity 14, the outlet cavity 15, and the medium outflow channel 12 in sequence.

[0024] A valve seat 40 is fixedly installed inside the valve seat cavity 14. The diameter of the valve core cavity 13 is smaller than the diameter of the valve seat cavity 14, so that a stepped surface is formed between the valve core cavity 13 and the valve seat cavity 14. A valve plate 41 cavity is provided at the bottom of the valve seat 40, and a valve plate 41 is fixedly embedded in the valve plate 41 cavity. The valve seat 40 has a central channel, and a valve port is formed at the lower end of the central channel. Specifically, a valve port is provided in the middle of the valve plate 41, and the valve port is connected to the central channel. The valve core 30 is axially slidably disposed in the valve core cavity 13. The upper end of the valve core 30 passes through the central channel of the valve seat 40 and abuts against or is connected to the diaphragm 20. The valve body 10 is provided with a means for mounting the valve core 30. Specifically, the valve core 30 has an abutment portion, a sealing portion, and a positioning portion. The sealing portion is a sealing structure with a gradually narrowing outer opening. The valve core 30 seals the valve port through the sealing portion. The abutment portion passes through the central channel and abuts against the diaphragm 20. The positioning portion is disposed inside the valve core cavity 13. The small spring 60 is sleeved on the outer periphery of the positioning portion. An abutment surface is formed between the positioning portion and the sealing portion. The upper end of the small spring 60 abuts against the abutment surface, and the other end of the small spring 60 abuts against the bottom of the valve core cavity 13. The elastic restoring force of the small spring 60 ensures that the upper end surface of the valve core 30 always abuts against the diaphragm 20.

[0025] The diaphragm 20 is disposed inside the outlet cavity 15 and its outer periphery is pressed against the diaphragm sealing surface 19 of the valve body 10. An elastic pressing assembly 50 is provided at the upper end of the diaphragm 20 for pressing the diaphragm 20 down to fit the valve seat 40. The diaphragm 20 has a flat portion 21 in the middle, and the outer periphery of the flat portion 21 has a downwardly recessed inner portion. The elastic pressing assembly 50 includes a pressure plate 51 abutting against the flat portion 21 of the diaphragm 20 and a first elastic member 52 acting on the pressure plate 51. The first elastic member 52 is a large spring and the elastic force of the first elastic member 52 is greater than the elastic force of the small spring 60. The lower end of the pressure plate 51 has a downwardly protruding lower protrusion 511. The lower protrusion 511 has a middle flat surface 512 and an arc-shaped surface 513 disposed on the outer periphery of the middle flat surface 512. The radius of the arc-shaped surface 513 of the lower protrusion 511 is R. When the diaphragm 20 is not subjected to the force of the elastic pressing assembly 50, the height between the flat portion 21 of the diaphragm 20 and the valve seat 40 is H, where 0.045≤H / R≤0.055. Specifically, the radius R of the arc surface 513 and the ratio of the flat portion 21 of the diaphragm 20 to the height H of the valve seat 40 when the diaphragm 20 is not subjected to the force of the elastic pressing component 50 will affect the initial contact area and the final contact area between the pressure plate 51 and the diaphragm 20. The difference between the initial contact area and the final contact area will affect the contact stress, thereby affecting the durability and service life of the diaphragm 20.

[0026] In the initial state, the pressure on the upper end face of the diaphragm 20 is greater than the supporting force on the lower end face of the diaphragm 20. At this time, the diaphragm 20 is pressed against the upper end face of the valve seat 40 by the pressure plate 51. In this state, the pressure plate 51 and the diaphragm 20 are in initial contact area. The flat part 21 of the diaphragm 20 and the middle flat surface 512 of the pressure plate 51 abut against most or all of the arc surface 513. The valve core 30 will be moved down and open the valve port by the action of the diaphragm 20. After the fluid medium is introduced into the medium inflow channel 11, the fluid pressure acting on the lower end face of the diaphragm 20 will push the diaphragm 20 up until the pressure acting on the upper end face of the diaphragm 20 and the thrust acting on the lower end face of the diaphragm 20 reach dynamic equilibrium. In this state, the pressure plate 51 and the diaphragm 20 are in final contact area. The flat part 21 of the diaphragm 20 abuts only against the middle flat surface 512 of the pressure plate 51.

[0027] In some embodiments, the flat portion 21 of the diaphragm 20 covers the lower protrusion 511 of the pressure plate 51. That is, the lower protrusion 511 of the pressure plate 51 is located in the area where the flat portion 21 of the diaphragm 20 is located.

[0028] In some embodiments, when the diaphragm 20 abuts against the upper surface of the valve seat 40 under the action of the elastic pressing assembly 50, the middle flat surface 512 and the arc-shaped surface 513 of the pressure plate 51 both fit against the upper surface of the flat portion 21 of the diaphragm 20.

[0029] In some embodiments, the middle flat surface 512 of the pressure plate 51 is in the upper end surface region of the valve seat 40, the arcuate surface 513 of the pressure plate 51 is in the upper end surface region of the valve seat 40, and the arcuate surface 513 of the pressure plate 51 is outside the upper end surface region of the valve seat 40.

[0030] Furthermore, where 0.9mm≤H≤1.1mm. When the diaphragm 20 is not subjected to the force of the elastic compression component 50, the height H of the flat portion 21 of the diaphragm 20 and the valve seat 40 is determined by the flow coefficient of each valve. If H is too large, it is not conducive to the miniaturization design of the pressure reducing valve; if H is too small, the discharge flow rate is too small.

[0031] In some embodiments, a pressure regulating assembly 70 is provided on the valve body 10. The pressure regulating assembly 70 includes a pressure block 71 and a connecting handle 72. The connecting handle 72 is rotatably connected to the valve body 10. The pressure block 71 is disposed at the lower end of the connecting handle 72 and located inside the valve body 10. The first elastic member 52 abuts against the pressure block 71 and the pressure plate 51. The pressure exerted by the elastic pressing assembly 50 on the diaphragm 20 is adjusted by adjusting the position of the pressure block 71 through the connecting handle 72. Specifically, the connecting handle 72 has a screwing part, which facilitates the user to screw the connecting handle 72.

[0032] In some embodiments, the upper end of the diaphragm 20 is provided with a central positioning post, and the diaphragm 20 is provided with an annular groove on the outer periphery of the central positioning post. The first elastic member 52 is partially accommodated in the annular groove and sleeved on the outer periphery of the central positioning post. This arrangement prevents the first elastic member 52 from shifting during the extension and contraction process, thereby improving its stability.

[0033] In some embodiments, the valve body 10 includes a first valve body 16, a second valve body 17, and a connecting sleeve 18 for connecting the first valve body 16 and the second valve body 17. The connecting ends of the first valve body 16 and the second valve body 17 are provided with diaphragm sealing surfaces 19. Specifically, the first valve body 16 is provided with a positioning groove with an upper opening, the second valve body 17 is disposed in the positioning groove, and the lower end of the second valve body 17 is provided with a flange. The upper end of the inner ring of the connecting sleeve 18 is provided with a tapered pressing surface, and the lower end of the inner ring is provided with a threaded connection portion. The connecting sleeve 18 is connected to the first valve body 16 through the threaded connection portion, and the second valve body 17 is firmly pressed onto the first valve body 16 through the pressing fit between the tapered pressing surface and the flange.

[0034] In some embodiments, the valve body 10 is provided with a limiting step 171, which limits the highest upward movement position of the pressure plate 51 by limiting the upper end surface of the pressure plate 51 with the limiting step 171.

[0035] In summary, the present invention has the following beneficial effects:

[0036] The pressure reducing valve of the present invention ensures that the stress between the diaphragm 20 and the pressure plate 51 is uniform in both the initial and final contact states by keeping the ratio of the height H of the flat portion 21 of the diaphragm 20 and the height H of the valve seat 40 to the radius R of the arc surface 513 of the lower protrusion 511 of the diaphragm 20 between 0.045 and 0.055 when the diaphragm 20 is not subjected to the force of the elastic pressing component 50. This prevents excessive local stress on the diaphragm 20 and effectively improves the service life of the diaphragm 20.

[0037] The experimental data for the maximum stress and service life of the diaphragm at different radii when the height H is 0.9 mm are as follows:

[0038]

[0039] The experimental data for the maximum stress and service life of the diaphragm at different radii when the height H is 1.026 mm are as follows:

[0040]

[0041] The experimental data for the maximum stress and service life of the diaphragm at different radii when the height H is 1.1 mm are as follows:

[0042]

[0043] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. A pressure reducing valve, characterized in that: The valve body (10) includes a valve body (10), a diaphragm (20), and a valve core (30). The valve body (10) is provided with a medium inflow channel (11), a medium outflow channel (12), a valve core cavity (13), a valve seat cavity (14), and an outlet cavity (15). A valve seat (40) is fixedly installed in the valve seat cavity (14). The diaphragm (20) is disposed in the outlet cavity (15), and the outer periphery of the diaphragm (20) is pressed against the diaphragm sealing surface (19) of the valve body (10). An elastic pressing component (50) is provided at the upper end of the diaphragm (20) for pressing the diaphragm (20) down to fit the valve seat (40). The valve seat (40) is provided with a central channel, and a valve port is formed at the lower end of the central channel. The valve core (30) is axially slidably disposed in the valve core cavity (13). The upper end of the valve core (30) passes through the central channel of the valve seat (40) and abuts against or connects to the diaphragm (20). The diaphragm (20) and valve body (10) are provided with a small spring (60) for pushing the valve core (30) upward. The diaphragm (20) has a flat portion (21) in the middle. The elastic pressing assembly (50) includes a pressure plate (51) abutting against the flat portion (21) of the diaphragm (20) and a first elastic member (52) acting on the pressure plate (51). The lower end of the pressure plate (51) has a downwardly protruding lower protrusion (511). The lower protrusion (511) has a central flat surface (512) and an arcuate surface (513) disposed on the outer periphery of the central flat surface (512). The radius of the arcuate surface (513) of the lower protrusion (511) is R. When the diaphragm (20) is not subjected to the force of the elastic pressing assembly (50), the height between the flat part (21) of the diaphragm (20) and the valve seat (40) is H, where 0.045≤H / R≤0.

055.

2. A pressure reducing valve according to claim 1, characterized in that: The flat portion (21) of the diaphragm (20) covers the lower protrusion (511) of the pressure plate (51).

3. A pressure reducing valve according to claim 1, characterized in that: When the diaphragm (20) abuts against the upper surface of the valve seat (40) under the action of the elastic pressing assembly (50), the middle flat surface (512) and the arc-shaped surface (513) of the pressure plate (51) are both attached to the upper surface of the flat part (21) of the diaphragm (20).

4. A pressure reducing valve according to claim 1, characterized in that: The middle flat surface (512) of the pressure plate (51) is in the upper end surface area of ​​the valve seat (40), the arc-shaped surface (513) of the pressure plate (51) is in the upper end surface area of ​​the valve seat (40), and the arc-shaped surface (513) of the pressure plate (51) is outside the upper end surface area of ​​the valve seat (40).

5. A pressure reducing valve according to any one of claims 1-4, characterized in that: Where 0.9mm≤H≤1.1mm.

6. A pressure reducing valve according to claim 5, characterized in that: A pressure regulating component (70) is provided on the valve body (10). The pressure regulating component (70) includes a pressure block (71) and a connecting handle (72). The connecting handle (72) is rotatably connected to the valve body (10). The pressure block (71) is located at the lower end of the connecting handle (72) and inside the valve body (10). The first elastic element (52) abuts against the pressure block (71) and the pressure plate (51). The pressure of the elastic pressing component (50) acting on the diaphragm (20) is adjusted by adjusting the position of the pressure block (71) through the connecting handle (72).

7. A pressure reducing valve according to claim 5, characterized in that: The upper end of the diaphragm (20) is provided with a central positioning post, and the diaphragm (20) is provided with an annular groove on the outer periphery of the central positioning post. The first elastic element (52) is partially accommodated in the annular groove and is sleeved on the outer periphery of the central positioning post.

8. A pressure reducing valve according to claim 5, characterized in that: The valve body (10) includes a first valve body (16), a second valve body (17), and a connecting sleeve (18) for connecting the first valve body (16) and the second valve body (17). The connecting end of the first valve body (16) and the second valve body (17) is provided with a diaphragm sealing surface (19).

9. A pressure reducing valve according to claim 5, characterized in that: The valve body (10) is provided with a limiting step (171), which limits the highest upward position of the pressure plate (51) by the limiting step (171) and the upper surface of the outer periphery of the pressure plate (51).

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