Pneumatic valve actuator of long-stroke shifting fork structure

Abstract

The utility model discloses a pneumatic valve actuator of a long-stroke shifting fork structure. The pneumatic valve actuator comprises a piston cylinder assembly, a box body assembly and a spring assembly. The box body assembly comprises a box body in butt joint with the front end of the cylinder body and a guide block arranged in the box body and used for bearing the piston rod and guiding operation of the piston rod. The spring assembly comprises a spring barrel connected with the front end of the box body, a spring seat arranged in the middle of the tail end in the spring barrel, a supporting spring arranged on the spring seat in a sleeving mode and a spring rod connected with the supporting spring and arranged in the spring barrel, and the box body assembly with a shifting fork and the spring assembly with the spring rod are sequentially arranged at the braking end of the piston cylinder assembly. A piston rod pair shifting fork transmission structure is adopted, torque complementation is well formed with a traditional product, the piston cylinder assembly, the box body assembly and the spring assembly are assembled into a whole, the appearance of the actuator is slender, the gravity center of the actuator is centered, and the operation reliability of the valve starting actuator is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pneumatic actuators, in particular to a pneumatic valve actuator with a long-stroke shift fork structure. Background Art

[0002] Traditional angular-turn actuators are all 1 / 4 partial-turn types, and are mainly used for valves with a 90-degree stroke, such as ball valves, butterfly valves, and plug valves. The present invention can be applied to three-way valves and special valves with a stroke of ≥90 degrees and less than 180 degrees.

[0003] Conventional large-stroke actuators are mainly gear rack structures, with cylinder bodies made of extruded aluminum profiles and racks made of die-cast aluminum alloy. Due to objective factors such as market demand and basic technology, the maximum cylinder diameter of products on the market can only be 240mm. As a result, when encountering large-torque valves, angular-stroke actuators can only be processed by forgings or castings. As a result, the angular-stroke actuators processed in this way have the disadvantages of bulky appearance, long delivery time, and low cost-effectiveness, which is difficult for conventional products to meet.

[0004] Therefore, the utility model provides a pneumatic valve actuator with a long-stroke fork structure that forms torque complementarity with traditional products. Utility Model Content

[0005] The utility model aims to provide a pneumatic valve actuator with a long-stroke fork structure to solve the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A pneumatic valve actuator with a long-stroke fork structure comprises a piston-cylinder assembly, a box assembly and a spring assembly, wherein the piston-cylinder assembly comprises a cylinder body, a piston arranged in the cylinder body and a piston rod which penetrates a rear cylinder cover at the rear end of the cylinder body through the movement of the piston;

[0008] The box assembly includes a box body docked with the front end of the cylinder body, a guide block arranged in the box body to receive the piston rod and guide the piston rod to run, and a transmission pin is arranged in the box body through the guide block and a shift fork is connected through the transmission pin;

[0009] The spring assembly includes a spring cylinder connected to the front end of the box body, a spring seat arranged in the middle of the end of the spring cylinder, a supporting spring sleeved on the spring seat, and a spring rod connected to the supporting spring and arranged in the spring cylinder, and the top end of the spring rod is connected to the end of the piston rod.

[0010] Furthermore, the rear cylinder cover is provided with a first oil-free bushing that cooperates with the horizontal and smooth movement of the piston rod. The first oil-free bushing is used to maintain the stability of the horizontal movement of the piston rod when the piston rod moves forward and backward as the cylinder body runs and the piston pushes it.

[0011] Furthermore, a second oil-free bushing and a third oil-free bushing are respectively provided above and below the corresponding shift fork on the box body, and the shift fork is positioned up and down by the second oil-free bushing and the third oil-free bushing to ensure the coaxiality and radial freedom of the shift fork when in use.

[0012] Furthermore, the connecting ends of the transmission pin respectively pass through the shift fork and the guide block and are provided with a copper slider.

[0013] Furthermore, a bushing seat is provided at the front end of the spring cylinder to cooperate with the horizontal movement of the spring rod, and the bushing seat cooperates with the spring rod to ensure stability when the spring rod moves along with the movement of the piston rod.

[0014] Furthermore, the rear end of the spring cylinder is provided with a rear cover which seals the rear end of the spring cylinder and facilitates the inspection of the spring cylinder. When an abnormality occurs to the spring rod or the support spring, the rear cover can be opened to check and inspect the status inside the spring cylinder to ensure the operation effect of the pneumatic valve actuator.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The pneumatic valve actuator with a long-stroke fork structure has a box assembly with a fork and a spring assembly with a spring rod arranged in sequence at the braking end of the piston cylinder assembly. The piston rod in the piston cylinder assembly cooperates with the transmission pin to produce a linkage with the fork. The piston rod to fork transmission structure can well form torque complementarity with traditional products. The piston cylinder assembly, the box assembly and the spring assembly are assembled into one, so that the actuator has a slender appearance and a central center of gravity, thereby improving the reliability of the starter valve actuator during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model;

[0018] Figure 2 For this utility model Figure 1 Schematic diagram of the cross-sectional structure along line AA.

[0019] In the figure: 1. Piston-cylinder assembly; 3. Spring assembly; 4. Cylinder body; 6. Rear cylinder cover; 7. Piston rod; 8. Box body; 9. Guide block; 10. Transmission pin; 11. Shift fork; 12. Spring cylinder; 13. Spring seat; 14. Support spring; 15. Spring rod; 16. First oil-free bushing; 17. Second oil-free bushing; 18. Third oil-free bushing; 19. Bushing seat; 20. Rear cover. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1-2 , the utility model provides a technical solution:

[0022] A pneumatic valve actuator with a long-stroke fork structure comprises a piston-cylinder assembly 1, a box assembly and a spring assembly 3. The piston-cylinder assembly 1 comprises a cylinder body 4, a piston 5 disposed in the cylinder body 4 and a piston rod 7 which passes through a rear cylinder cover 6 at the rear end of the cylinder body 4 through the movement of the piston 5.

[0023] The box assembly includes a box 8 connected to the front end of the cylinder 4, a guide block 9 arranged in the box 8 to receive the piston rod 7 and guide the piston rod 7 to run, a transmission pin 10 is arranged in the box 8 through the guide block 9, and a shift fork 11 is connected through the transmission pin 10;

[0024] The spring assembly 3 includes a spring barrel 12 connected to the front end of the box body 8, a spring seat 13 arranged in the middle of the inner end of the spring barrel 12, a support spring 14 sleeved on the spring seat 13, and a spring rod 15 connected with the support spring 14 and arranged in the spring barrel 12. The top end of the spring rod 15 is connected to the end of the piston rod 7. The spring barrel 12 adopts an extended design to greatly shorten the length of the spring rod 15 and improve the stiffness and straightness of the spring rod 15. The spring rod 15 is manufactured with a spring rod 15 with a better height-to-diameter ratio and winding ratio to ensure that within the ultra-long full stroke range, the problem of the spring rod 15 bending sideways and rubbing against the inner wall of the spring barrel 12 is avoided.

[0025] The rear cylinder cover 6 is provided with a first oil-free bushing 16 that cooperates with the piston rod 7 to move horizontally and smoothly. The first oil-free bushing 16 is used to keep the horizontal movement of the piston rod 7 stable when the piston rod 7 moves forward and backward as the cylinder body 4 runs and the piston pushes.

[0026] A second oil-free bushing 17 and a third oil-free bushing 18 are respectively provided above and below the housing 8 corresponding to the fork 11. The second oil-free bushing 17 and the third oil-free bushing 18 are used to position the fork 11 up and down to ensure the coaxiality and radial freedom of the fork 11 when in use.

[0027] The connecting ends of the transmission pin 10 respectively penetrate the shift fork 11 and the guide block 9 and are provided with a copper slider.

[0028] The front end of the spring tube 12 is provided with a bushing seat 19 that cooperates with the horizontal movement of the spring rod 15. The spring rod 15 passes through the bushing seat 19, and the bushing seat 19 cooperates with the spring rod 15 to ensure stability when it moves along with the linear movement of the piston rod 7.

[0029] The rear end of the spring barrel 12 is provided with a rear cover 20 which seals the rear end of the spring barrel 12 and facilitates the inspection of the spring barrel 12. When the spring rod 15 or the support spring 14 is abnormal, the rear cover 20 can be opened to check and inspect the status of the spring barrel 12 to ensure the operation effect of the pneumatic valve actuator.

[0030] The pneumatic valve actuator of the long-stroke fork structure has a box assembly with a fork 11 and a spring assembly 3 with a spring rod 15 arranged in sequence at the braking end of the piston cylinder assembly 1. The piston rod 7 in the piston cylinder assembly 1 cooperates with the transmission pin 10 to produce a linkage with the fork 11. The transmission structure of the piston rod 7 to the fork 11 can well form torque complementation with traditional products. The piston cylinder assembly 1, the box assembly and the spring assembly 3 are assembled into one body, so that the actuator has a slender appearance and a central center of gravity, thereby improving the reliability of the valve actuator when it is started;

[0031] The pneumatic valve actuator with a long stroke fork structure takes a stroke of 120 degrees as an example. The actuator's fork 11 adopts a symmetrical slot design. The angles corresponding to the start, run and end points of the actuator are 0°, 60° and 120° respectively. Assuming the eccentricity is l, the lever arm L = l / cos60°, and the rated stroke of the slot size of the fork 11 is S = l*tan60°*2. At the same time, the adjustment stroke of the two extreme positions of 0 degrees and 120 degrees is retained within ±5 degrees.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pneumatic valve actuator with a long-stroke fork structure, comprising a piston-cylinder assembly (1), a box assembly and a spring assembly (3), characterized in that: The piston-cylinder assembly (1) comprises a cylinder body (4), a piston arranged in the cylinder body (4), and a piston rod (7) which is moved by the piston (5) and penetrates a rear cylinder cover (6) at the rear end of the cylinder body (4); The box assembly comprises a box (8) docked with the front end of the cylinder (4), a guide block (9) arranged in the box (8) to receive the piston rod (7) and guide the operation of the piston rod (7), a transmission pin (10) is arranged in the box (8) through the guide block (9) and a shift fork (11) is connected through the transmission pin (10); The spring assembly (3) comprises a spring cylinder (12) connected to the front end of the box body (8), a spring seat (13) arranged at the middle of the inner end of the spring cylinder (12), a support spring (14) sleeved on the spring seat (13), and a spring rod (15) connected to the support spring (14) and arranged in the spring cylinder (12), wherein the top end of the spring rod (15) is butted against the end of the piston rod (7).

2. The pneumatic valve actuator with a long-stroke fork structure according to claim 1, characterized in that: The rear cylinder cover (6) is provided with a first oil-free bushing (16) which cooperates with the piston rod (7) to move horizontally and smoothly.

3. The pneumatic valve actuator with a long-stroke fork structure according to claim 2, characterized in that: A second oil-free bushing (17) and a third oil-free bushing (18) are respectively provided above and below the corresponding shift fork (11) on the box body (8), so that the shift fork (11) can be positioned up and down by the second oil-free bushing (17) and the third oil-free bushing (18).

4. The pneumatic valve actuator with a long-stroke fork structure according to claim 1, characterized in that: The connecting ends of the transmission pin (10) respectively penetrate the shift fork (11) and the guide block (9) and are provided with a copper sliding block.

5. The pneumatic valve actuator with a long-stroke fork structure according to claim 4, characterized in that: The front end of the spring cylinder (12) is provided with a bushing seat (19) which cooperates with the spring rod (15) to move horizontally.

6. The pneumatic valve actuator with a long-stroke fork structure according to claim 5, characterized in that: The rear end of the spring cylinder (12) is provided with a rear cover (20) which seals the rear end of the spring cylinder (12) and facilitates maintenance of the inside of the spring cylinder (12).

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