A pneumatic high sealing L-type valve

Abstract

The application discloses a pneumatic L-shaped valve with high sealing performance, which comprises a valve body, a pneumatic driving unit and a bellows assembly. The valve body is internally provided with a first chamber, and the one end and the top of the valve body are respectively provided with a first interface and a second interface which are in communication with the first chamber. The bellows assembly comprises a sealing valve cover, a first bellows and a bellows mounting seat. The bellows mounting seat is connected to the other end of the valve body. The first bellows of the application can axially stretch and shrink along with the reciprocating movement of the sealing valve cover, so that the movement of the driving rod can be transmitted to the sealing valve cover, and the driving rod is separated from the vacuum environment in the first chamber. Therefore, the dynamic sealing structure for the driving rod to slide through is not needed on the vacuum side, the gas leakage path formed due to the abrasion of the sliding sealing element can be reduced, and the possibility of the lubricating medium or the abrasion particles entering the vacuum flow channel is lowered.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a pneumatically operated L-type valve with high sealing performance. Background Technology

[0002] Existing pneumatic vacuum valves typically use a cylinder to drive a piston rod in reciprocating motion, which in turn opens or closes the valve cover. Since the piston rod needs to extend into the valve body from the cylinder side, existing designs usually incorporate sliding seals such as O-rings, oil seals, or packing between the piston rod and the valve body or end cover to prevent outside air or driving gas from entering the vacuum passage. However, during long-term, frequent opening and closing of the valve, continuous friction occurs between the piston rod and the sliding seal, easily causing wear, aging, or plastic deformation of the seal. This allows outside gas to enter the vacuum passage through the gap between the piston rod and the seal, affecting the vacuum level and operational stability of the vacuum system.

[0003] Meanwhile, some sliding seal structures require the use of lubricating media to reduce frictional resistance. The gases generated by the evaporation of the lubricating media and the particles produced by seal wear may enter the vacuum environment, adversely affecting production processes with high cleanliness requirements. As seal wear increases, valves are also prone to problems such as increased opening and closing resistance, decreased sealing performance, and shortened service life.

[0004] Furthermore, the valve stem sealing structure of existing vacuum valves is typically distributed among the valve body, end cap, and cylinder. When the seals reach the end of their service life or become damaged, it is often necessary to remove the entire valve from the vacuum pipeline, and then disassemble the valve body, cylinder, and valve stem sequentially to remove and replace the corresponding seals. This maintenance process is cumbersome and time-consuming, and reassembly can easily lead to secondary leaks due to misalignment of the seals or improper compression, which is detrimental to reducing equipment maintenance costs and downtime. Summary of the Invention

[0005] The purpose of this invention is to provide a pneumatically operated L-type valve with high sealing performance. This invention features a bellows assembly on the outside of the drive rod, consisting of a sealing valve cover, a first bellows, and a bellows mounting base. The first bellows can axially extend and retract with the reciprocating motion of the sealing valve cover, allowing the movement of the drive rod to be transmitted to the sealing valve cover while simultaneously isolating the drive rod from the vacuum environment in the first chamber. Therefore, a dynamic sealing structure for the drive rod to slide through is not required on the vacuum side, reducing gas leakage paths caused by wear of the sliding seal and lowering the possibility of lubricating media or wear particles entering the vacuum flow channel.

[0006] To achieve the above objectives, the following technical solution is adopted: A pneumatically operated, high-sealing L-shaped valve includes a valve body, a pneumatic drive unit, and a bellows assembly. The valve body has a first chamber, and one end and the top of the valve body are respectively provided with a first interface and a second interface communicating with the first chamber. The bellows assembly includes a sealing valve cover, a first bellows, and a bellows mounting seat. The bellows mounting seat is connected to the other end of the valve body. The first bellows is arranged within the first chamber, and one end of the first bellows is connected to the bellows mounting seat. The sealing valve cover is arranged at the inner opening of the first interface communicating with the first chamber and is connected to the other end of the first bellows. A first sealing ring is also installed on the side of the sealing valve cover near the first interface. The pneumatic drive unit is installed at the other end of the valve body. The pneumatic drive unit includes a drive rod, one end of which is inserted into the first bellows and connected to the sealing valve cover. The drive rod can drive the sealing valve cover to reciprocate relative to the valve body, thereby pressing the first sealing ring against the inner end face of the first interface or moving the first sealing ring away from the inner end face of the first interface, thus opening or closing the first interface.

[0007] Furthermore, one end of the drive rod is provided with a threaded connection section, and the diameter of the threaded connection section is smaller than the diameter of the drive rod; a limiting step is provided at the connection between the threaded connection section and the drive rod; the sealing valve cover is sleeved on the threaded connection section and abuts against the limiting step; a locking nut is also screwed onto one side of the threaded connection section located on the sealing valve cover, and the locking nut is used to lock and fix the sealing valve cover.

[0008] Furthermore, a first O-ring and a first washer, which are fitted onto the threaded connection section, are sequentially provided between one side of the sealing valve cover and the locking nut.

[0009] Furthermore, the pneumatic drive unit also includes a cylinder and a piston; the cylinder is connected to the other end of the valve body, and a second chamber is also provided inside the cylinder; a front cover is provided at one end of the second chamber near the valve body to seal the second chamber; the piston is slidably arranged in the second chamber, one end of the drive rod passes through the front cover and is inserted into the first bellows, and the other end of the drive rod is connected to the piston.

[0010] Furthermore, a limiting block is also sleeved on the drive rod on the other side of the sealing valve cover; a first spring is also sleeved on the outer wall of the drive rod between the limiting block and the front cover.

[0011] Furthermore, the front cover is fitted into the second chamber, and the inner wall of the second chamber is provided with a first retaining ring on one side of the front cover; the outer wall of the front cover is also fitted with a second O-ring; the center of the front cover is also provided with a first guide hole for the drive rod to pass through, and the inner wall of the first guide hole is also provided with a rod seal and a sliding bushing, through which the drive rod is arranged.

[0012] Furthermore, the outer wall of the piston is fitted with a second sealing ring and a magnetic ring; a buffer pad is also provided on the side of the piston away from the front cover.

[0013] Furthermore, a third sealing ring is also embedded in the outer wall of the bellows mounting base.

[0014] By adopting the above solution, the beneficial effects of the present invention are: 1) This invention provides a bellows assembly on the outside of the drive rod, consisting of a sealing valve cover, a first bellows, and a bellows mounting base. The first bellows can axially extend and retract with the reciprocating motion of the sealing valve cover, allowing the motion of the drive rod to be transmitted to the sealing valve cover while isolating the drive rod from the vacuum environment in the first chamber. Therefore, a dynamic sealing structure for the drive rod to slide through is not required on the vacuum side, reducing gas leakage paths caused by wear of the sliding seal and lowering the possibility of lubricating media or wear particles entering the vacuum channel. 2) The pneumatic drive unit and the valve body are detachably connected. The sealing valve cover is detachably connected to the drive rod through a threaded connection section, a limiting step and a locking nut. When the first bellows or related seals need to be replaced, the connection between the pneumatic drive unit and the valve body can be disconnected, and the connection between the sealing valve cover and the drive rod can be disconnected, so that the bellows assembly can be taken out as a whole, reducing the disassembly of the valve body and the internal components of the pneumatic drive unit, reducing the difficulty of maintenance and the risk of assembly errors. 3) By applying a reset force to the limit block through the first spring, when the gas supply stops, the drive rod can drive the sealing valve cover to automatically press the inner end face of the first interface, so that the valve remains in a normally closed state. When the gas source fails or the equipment stops unexpectedly, the valve can still close automatically, which helps to improve the failure safety performance of the vacuum system. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the present invention; The following are explanations of the labels in the attached diagram: 1. Valve body; 2. Pneumatic drive unit; 3. Bellows assembly; 11. First chamber; 12. First interface; 13. Second interface; 21. Drive rod; 22. Cylinder; 23. Piston; 24. Front cover; 25. First retaining ring; 26. Second O-ring; 27. Rod seal; 28. Sliding bushing; 31. Sealing valve cover; 32. First bellows; 33. Bellows mounting seat; 34. Third sealing ring; 211. Threaded connection section; 212. Limiting step; 213. Locking nut; 214. First O-ring; 215. First gasket; 216. Limiting block; 217. First spring; 231. Second sealing ring; 232. Magnetic ring; 233. Buffer pad; 311. First sealing ring. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0017] Reference Figures 1 to 2 As shown, the present invention provides a pneumatically operated, high-sealing L-shaped valve. In one embodiment, it includes a valve body 1, a pneumatic drive unit 2, and a bellows assembly 3. The valve body 1 has a first chamber 11, and one end and the top of the valve body 1 are respectively provided with a first interface 12 and a second interface 13 communicating with the first chamber 11. The bellows assembly 3 includes a sealing valve cover 31, a first bellows 32, and a bellows mounting seat 33. The bellows mounting seat 33 is connected to the other end of the valve body 1. The first bellows 32 is arranged in the first chamber 11, and one end of the first bellows 32 is connected to the bellows mounting seat 33. The sealing valve cover 31 is arranged between the first interface 12 and the second interface 13. The inner opening of the chamber 11 is connected to the other end of the first bellows 32; a first sealing ring 311 is also installed on the side of the sealing valve cover 31 near the first interface 12; the pneumatic drive unit 2 is installed on the other end of the valve body 1; the pneumatic drive unit 2 includes a drive rod 21, one end of which is inserted into the first bellows 32 and connected to the sealing valve cover 31; the drive rod 21 can drive the sealing valve cover 31 to reciprocate relative to the valve body 1, so as to press the first sealing ring 311 against the inner end face of the first interface 12 or drive the first sealing ring 311 away from the inner end face of the first interface 12, thereby opening or closing the first interface 12.

[0018] like Figure 2 As shown, in this embodiment, the axis of the first interface 12 is perpendicular to the axis of the second interface 13, so that the first interface 12, the first chamber 11 and the second interface 13 together form an L-shaped gas flow path; an annular sealing end face is formed around the inner opening of the first interface 12 communicating with the first chamber 11. The sealing end face is flattened to cooperate with the sealing valve cover 31. The sealing valve cover 31 has an annular mounting groove on the side facing the first interface 12, and the first sealing ring 311 is embedded in the annular mounting groove; when the sealing valve cover 31 moves toward the first interface 12, the first sealing ring 311 contacts the inner end face of the first interface 12 and is axially compressed, thereby sealing the communication position between the first interface 12 and the first chamber 11; when the sealing valve cover 31 moves away from the first interface 12, the first sealing ring 311 disengages from the inner end face of the first interface 12, so that the first interface 12 communicates with the second interface 13 through the first chamber 11.

[0019] The bellows assembly 3 includes a sealing valve cover 31, a first bellows 32, and a bellows mounting seat 33. The bellows mounting seat 33 is installed on the other end of the valve body 1 away from the first interface 12 (this end has an installation port, and the bellows mounting seat 33 is installed in the installation port). The first bellows 32 is located in the first chamber 11. One end of the first bellows 32 is sealed to the bellows mounting seat 33, and the other end of the first bellows 32 is sealed to the sealing valve cover 31, so that the sealing valve cover 31, the first bellows 32, and the bellows mounting seat 33 together form an assembly that can be installed and disassembled as a whole.

[0020] The bellows mounting seat 33 has a central through hole through which the drive rod 21 passes. The outer wall of the bellows mounting seat 33 has an annular sealing groove. The third sealing ring 34 is installed in the annular sealing groove. After the bellows mounting seat 33 is installed on the valve body 1, the third sealing ring 34 is pressed between the bellows mounting seat 33 and the inner wall of the mounting port, thereby forming a static seal between the two without relative sliding. The pneumatic drive unit 2 is installed at the other end of the valve body 1. After the pneumatic drive unit 2 is installed in place, it can also axially position the bellows mounting seat 33 to prevent the bellows mounting seat 33 from axially moving relative to the valve body 1 during the opening and closing of the valve.

[0021] In this embodiment, the first bellows 32 is sleeved on the outside of the drive rod 21. The drive rod 21 extends into the first bellows 32 through the central through hole of the bellows mounting base 33 and connects to the sealing valve cover 31. The outer peripheral surface of the first bellows 32 faces the vacuum environment in the first chamber 11, and the internal space of the first bellows 32 corresponds to the drive side. Therefore, the drive rod 21 is not directly exposed to the vacuum environment in the first chamber 11. The first bellows 32 adapts to the reciprocating motion of the sealing valve cover 31 and the drive rod 21 through its own axial expansion and contraction, and continuously isolates the vacuum side from the drive side.

[0022] In some embodiments, the end of the drive rod 21 near the sealing valve cover 31 is provided with a threaded connection section 211. The diameter of the threaded connection section 211 is smaller than the diameter of the main body of the drive rod 21, thereby forming a limiting step 212 at the connection position between the threaded connection section 211 and the main body of the drive rod 21. The middle part of the sealing valve cover 31 is provided with a mounting hole that matches the threaded connection section 211. The sealing valve cover 31 is sleeved on the threaded connection section 211 and abuts against the limiting step 212.

[0023] A first O-ring 214 and a first washer 215 are sequentially arranged on the side of the sealing valve cover 31 away from the limiting step 212. The locking nut 213 is screwed onto the threaded connection section 211. The locking nut 213 presses the sealing valve cover 31 through the first washer 215, so that the sealing valve cover 31 is stably fixed between the limiting step 212 and the locking nut 213. The first O-ring 214 can seal the mating position between the mounting hole of the sealing valve cover 31 and the threaded connection section 211. The first washer 215 can disperse the axial pressure applied by the locking nut 213 and reduce the torsional or compressive damage to the first O-ring 214 during the locking process.

[0024] In some embodiments, the pneumatic drive unit 2 includes a cylinder 22, a front cover 24, a piston 23, and a drive rod 21; a second chamber is formed inside the cylinder 22, and one end of the cylinder 22 facing the valve body 1 is detachably connected to the valve body 1; the front cover 24 is fitted into the second chamber near the valve body 1 to close the second chamber; the piston 23 is slidably installed in the second chamber, one end of the drive rod 21 is connected to the piston 23, and the other end of the drive rod 21 passes through the front cover 24 and extends into the first bellows 32, and is connected to the sealing valve cover 31 through a threaded connection section 211.

[0025] Preferably, the outer wall of the front cover 24 is provided with an annular groove, and the second O-ring 26 is installed in the annular groove and pressed between the front cover 24 and the inner wall of the cylinder 22, thereby sealing the installation gap between the front cover 24 and the cylinder 22; the inner wall of the cylinder 22 is provided with a retaining ring mounting groove on one side of the front cover 24, and the first retaining ring 25 is installed in the retaining ring mounting groove and abuts against the front cover 24 to restrict the front cover 24 from moving axially along the second chamber.

[0026] The front cover 24 has a first guide hole at its center for the drive rod 21 to pass through. A rod seal 27 and a sliding bushing 28 are installed in the first guide hole. The sliding bushing 28 is slidably engaged with the drive rod 21 to guide the reciprocating motion of the drive rod 21 and reduce the radial swing of the drive rod 21. The rod seal 27 is slidably sealed with the outer circumferential surface of the drive rod 21 to prevent the compressed gas in the second chamber from leaking along the gap between the drive rod 21 and the first guide hole.

[0027] Meanwhile, a second sealing ring 231 is provided on the outer periphery of the piston 23. The second sealing ring 231 slides and seals with the inner wall of the cylinder 22, so that the spaces on both sides of the piston 23 are separated from each other. A magnetic ring 232 is also installed on the outer periphery of the piston 23. The magnetic ring 232 can adopt a split structure so as to be assembled on the piston 23. The magnetic ring 232 can move synchronously with the piston 23 and can cooperate with the magnetic detection element installed on the outside of the cylinder 22 to detect the position of the piston 23 or determine the opening and closing status of the valve. A buffer pad 233 is provided on the side of the piston 23 away from the front cover 24. When the piston 23 moves to the end of its stroke away from the front cover 24, the buffer pad 233 can reduce the impact between the piston 23 and the end of the cylinder 22.

[0028] In some embodiments, a limiting block 216 and a first spring 217 are fitted onto the portion of the drive rod 21 located between the sealing valve cover 31 and the front cover 24; the limiting block 216 is installed on the drive rod 21 near the sealing valve cover 31 and can move synchronously with the drive rod 21; the first spring 217 is fitted onto the outside of the drive rod 21, with one end abutting against the front cover 24 and the other end abutting against the limiting block 216; the first spring 217 is in a pre-compressed state and applies an elastic force toward the first interface 12 to the drive rod 21 through the limiting block 216.

[0029] A rod chamber for compressed air is formed between piston 23 and front cover 24. Cylinder 22 is provided with an intake and exhaust passage communicating with the rod chamber. When the valve needs to be opened, compressed air is introduced into the rod chamber through the intake and exhaust passage. The compressed air acts on the side of piston 23 facing front cover 24 and pushes piston 23 to move away from front cover 24. Piston 23 drives drive rod 21 to retract. Drive rod 21 simultaneously drives limit block 216 and sealing valve cover 31 to move away from first interface 12. Limit block 216 compresses first spring 217 during movement. After sealing valve cover 31 moves, first sealing ring 311 disengages from inner end face of first interface 12, so that first interface 12 is connected to second interface 13 through first chamber 11, and valve switches from closed state to open state.

[0030] After the supply of compressed air to the rod chamber is stopped and the rod chamber is vented, the gas pressure acting on the piston 23 decreases; the first spring 217 releases its elastic potential energy and pushes the limiting block 216 towards the first interface 12. The limiting block 216 drives the drive rod 21 to extend, and the drive rod 21 further drives the sealing valve cover 31 towards the first interface 12. When the first sealing ring 311 contacts the inner end face of the first interface 12, the elastic force continued to be applied by the first spring 217 causes the first sealing ring 311 to be axially compressed, thereby closing the first interface 12. Thus, when the air supply is interrupted or the air pressure is insufficient, the valve can automatically return to the closed state by relying on the first spring 217.

[0031] During the opening or closing of the sealing valve cover 31, the first bellows 32 undergoes axial compression or elongation synchronously with the sealing valve cover 31. Although the wall of the first bellows 32 undergoes elastic deformation, there is no sliding sealing interface between the first bellows 32 and the sealing valve cover 31, or between the first bellows 32 and the bellows mounting seat 33. Therefore, it can maintain the isolation between the vacuum side and the drive side while transmitting axial movement. There is no sliding gap between the first chamber 11 outside the first bellows 32 and the drive rod 21, which can reduce the risk of drive gas, outside air and drive-side contaminants entering the vacuum channel.

[0032] In addition, when the bellows assembly 3 needs to be replaced, first, the valve and its vacuum system should be brought into a maintainable state. Then, the pneumatic drive unit 2 should be disconnected to separate the cylinder 22 from the valve body 1. Then, the connection between the locking nut 213 and the threaded connection section 211 should be released, and the first gasket 215 and the first O-ring 214 should be removed in sequence to disconnect the sealing valve cover 31 from the drive rod 21. At this time, the bellows assembly 3, which consists of the sealing valve cover 31, the first bellows 32 and the bellows mounting seat 33, can be taken out of the valve body 1 as a whole for replacement, which is convenient.

[0033] In one alternative embodiment, the valve body 1 can be made of aluminum alloy to reduce the weight of the valve; the sealing valve cover 31, the first bellows 32, and the bellows mounting base 33 can be made of corrosion-resistant metal; the first interface 12 and the second interface 13 can adopt a vacuum flange structure for connection to a vacuum pipeline or vacuum chamber; the specific specifications of the first sealing ring 311, the first O-ring 214, the second O-ring 26, the second sealing ring 231, and the third sealing ring 34 can be selected according to the valve interface size, working pressure, working temperature, and the medium in contact with it, and there are no restrictions on this.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pneumatically operated, high-sealing L-type valve, characterized in that, The system includes a valve body, a pneumatic drive unit, and a bellows assembly. The valve body has a first chamber, and one end and the top of the valve body are respectively provided with a first interface and a second interface communicating with the first chamber. The bellows assembly includes a sealing valve cover, a first bellows, and a bellows mounting base. The bellows mounting base is connected to the other end of the valve body. The first bellows is arranged within the first chamber, and one end of the first bellows is connected to the bellows mounting base. The sealing valve cover is arranged at the inner opening of the first interface communicating with the first chamber and is connected to the other end of the first bellows. A first sealing ring is also installed on the side of the sealing valve cover near the first interface. The pneumatic drive unit is installed at the other end of the valve body. The pneumatic drive unit includes a drive rod, one end of which is inserted into the first bellows and connected to the sealing valve cover. The drive rod can drive the sealing valve cover to reciprocate relative to the valve body, thereby pressing the first sealing ring against the inner end face of the first interface or moving the first sealing ring away from the inner end face of the first interface, thus opening or closing the first interface.

2. The pneumatic high-sealing L-type valve according to claim 1, characterized in that, One end of the drive rod is also provided with a threaded connection section, and the diameter of the threaded connection section is smaller than the diameter of the drive rod; a limiting step is provided at the connection between the threaded connection section and the drive rod; the sealing valve cover is sleeved on the threaded connection section and abuts against the limiting step; a locking nut is also screwed onto one side of the threaded connection section located on the sealing valve cover, and the locking nut is used to lock and fix the sealing valve cover.

3. The pneumatic high-sealing L-type valve according to claim 2, characterized in that, One side of the sealing valve cover and the locking nut are also provided with a first O-ring and a first washer that are fitted onto the threaded connection section.

4. The pneumatic high-sealing L-type valve according to claim 1, characterized in that, The pneumatic drive unit also includes a cylinder and a piston; the cylinder is connected to the other end of the valve body, and a second chamber is also provided inside the cylinder; a front cover is provided at one end of the second chamber near the valve body to seal the second chamber; the piston is slidably arranged in the second chamber, one end of the drive rod passes through the front cover and is inserted into the first bellows, and the other end of the drive rod is connected to the piston.

5. The pneumatic high-sealing L-type valve according to claim 4, characterized in that, A limiting block is also sleeved on the drive rod on the other side of the sealing valve cover; a first spring is also sleeved on the outer wall of the drive rod between the limiting block and the front cover.

6. The pneumatic high-sealing L-type valve according to claim 4, characterized in that, The front cover is fitted into the second chamber, and the inner wall of the second chamber is provided with a first retaining ring on one side of the front cover; the outer wall of the front cover is also fitted with a second O-ring; the center of the front cover is also provided with a first guide hole for the drive rod to pass through, and the inner wall of the first guide hole is also provided with a rod seal and a sliding bushing, and the drive rod passes through the rod seal and the sliding bushing.

7. The pneumatic high-sealing L-type valve according to claim 6, characterized in that, The piston is fitted with a second sealing ring and a magnetic ring on its outer wall; a buffer pad is also provided on the side of the piston away from the front cover.

8. The pneumatic high-sealing L-type valve according to claim 1, characterized in that, The outer wall of the bellows mounting base is also fitted with a third sealing ring.

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