Three-section type pneumatic actuator with accurate positioning function

Abstract

The invention provides a three-section type pneumatic actuator accurate in positioning, and relates to the technical field of pneumatic actuators. The three-section type pneumatic actuator with the accurate positioning function comprises two cylinder bodies, two ratchet wheel and pawl mechanisms, a double-arc helical tooth gear and rack mechanism and a straight tooth gear and rack mechanism. A group of double-arc helical tooth gear rack mechanism and straight tooth gear rack mechanism are adopted to provide transmission respectively, when the valve needs to be opened according to a set angle, compressed gas is introduced into the two cylinder bodies in sequence, so that the double-arc helical tooth rack drives the double-arc helical gear to rotate firstly, and then the straight tooth gear rack drives the straight tooth gear to rotate; the valve is driven to rotate to a preset angle through the ratchet and pawl mechanism and the connecting column, then the straight toothed spur gear is driven to rotate through the straight toothed rack, the angle of the valve is further accurately adjusted to the set angle of the valve, and the positioning accuracy of the pneumatic actuator is greatly improved through the successive control mode.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic actuators, and in particular to a three-stage pneumatic actuator with precise positioning. Background Art

[0002] The three-stage pneumatic actuator is a key device widely used in the industrial field. Its main function is to use compressed air, a powerful power source, to accurately drive valves and other equipment. The actuator consists of two independent cylinders and a key connecting part in the middle. Its working principle is to push the piston in the cylinder to move by passing compressed air into the cylinder in an orderly manner. In this process, the movement of the piston can effectively control the opening or closing of the valve and realize the precise regulation of the fluid channel.

[0003] In the prior art, the two cylinders of a three-stage pneumatic actuator usually synchronously control the opening or closing action of the valve. However, this synchronous control method has obvious disadvantages. Since the two cylinders lack an effective coordination mechanism during the action process, mutual interference is likely to occur. This interference will cause the actions of the two cylinders to be inconsistent, which will have a serious negative impact on the positioning accuracy of the pneumatic actuator.

[0004] To this end, we have developed a new three-stage pneumatic actuator with precise positioning. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a three-stage pneumatic actuator with precise positioning, which solves the problem in the prior art that the two cylinders of the three-stage pneumatic actuator have uncoordinated movements when synchronously controlling the opening or closing of a valve, resulting in inaccurate positioning of the actuator.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a three-stage pneumatic actuator with precise positioning, comprising a box body, cylinder bodies are fixedly installed on both sides of the box body, a steering assembly is fixedly installed in the box body, a first driving member is slidably matched in one of the cylinder bodies, and a second driving member is slidably matched in the other of the cylinder bodies;

[0009] The steering assembly includes a connecting column that is rotatably matched with the box body, and the circumferential side surface of the connecting column is provided with two groups of mounting grooves in a circumferential array, and two symmetrical support columns are fixedly connected in the mounting grooves, and the circumferential side surface of one support column is rotatably matched with a non-return pawl, and the circumferential side surface of the other support column is fixedly sleeved with an arc-shaped metal spring sheet, and the arc-shaped metal spring sheet is located between the non-return pawl and the mounting groove;

[0010] The circumferential side surface of the connecting column is rotatably matched with two ratchets, the circumferential side surface of the connecting column is located at one end of the ratchet and is rotatably matched with a double arc bevel gear, and the circumferential side surface of the connecting column is located at the other end of the ratchet and is rotatably matched with a spur cylindrical gear, and the module and number of teeth of the spur cylindrical gear are both greater than those of the double arc bevel gear.

[0011] Preferably, the side surfaces of the connection columns are fixedly connected to trapezoidal limiting rings at the other ends of the two ratchets, and the other ends of the ratchets are fixedly connected to connecting rings that rotatably cooperate with the trapezoidal limiting rings.

[0012] Preferably, one end of the ratchet is fixedly connected to a plurality of plug plates in a circular array, and one end of the double arc helical gear and the spur gear are penetrated by a plurality of through grooves in a circular array, and the through grooves are slidably matched with the plug plates.

[0013] Preferably, the first driving member includes a first piston slidingly matched with the cylinder body, one end of the first piston is fixedly connected to a first connecting plate, the first connecting plate slides through the cylinder body, one end of the first connecting plate is fixedly connected to a double-arc helical rack, and the double-arc helical rack is meshingly matched with the double-arc helical gear.

[0014] Preferably, the second driving member includes a second piston that slides with the other cylinder body, one end of the second piston is fixedly connected to a second connecting plate, the second connecting plate slides through the other cylinder body, one end of the second connecting plate is fixedly connected to a spur rack, and the spur rack meshes with the spur cylindrical gear.

[0015] Preferably, a plurality of slots are provided on the peripheral side surface of the connecting column in a circular array between the two groups of mounting slots.

[0016] Preferably, a plurality of slide grooves are provided on the inner circumferential side surface of the double circular arc bevel gear in a circumferential array, a clamping block is slidably fitted in the slide groove, and a spring is fixedly connected to one end of the clamping block in the slide groove.

[0017] Preferably, a first air port is provided on one side of the cylinder body near one end thereof, and a second air port is provided on one side of the cylinder body near the other end thereof, and both the first air port and the second air port are connected to the cylinder body.

[0018] Preferably, a third air port is provided on one side of the other cylinder body near one end thereof, and a fourth air port is provided on one side of the other cylinder body near the other end thereof, and the third air port and the fourth air port are both connected to the other cylinder body.

[0019] Preferably, one end of the connecting column is fixedly connected to a transmission shaft, and a mounting plate is fixedly connected to a peripheral side surface of the transmission shaft.

[0020] (III) Beneficial effects

[0021] The present invention provides a three-stage pneumatic actuator with precise positioning, which has the following beneficial effects:

[0022] The three-stage pneumatic actuator with precise positioning adopts a set of double-arc helical gear rack mechanism and spur gear rack mechanism to provide transmission respectively. When the valve needs to be opened at a set angle, compressed gas is first introduced into one cylinder to make the double-arc helical gear rack drive the double-arc helical gear to rotate, and then the valve is driven to rotate to a predetermined angle (less than the set angle for opening the valve) through the ratchet pawl mechanism and the connecting column. Then compressed gas is introduced into the other cylinder, and the spur gear rack drives the spur cylindrical gear to rotate, so as to further accurately adjust the valve angle to the set angle. Since the module and number of teeth of the spur cylindrical gear are greater than those of the double-arc helical gear, when the two sets of gear racks are normally meshed and move the same distance, the rotation angle of the spur cylindrical gear is smaller than that of the double-arc helical gear. Therefore, this sequential control method greatly improves the positioning accuracy of the pneumatic actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional diagram after the present invention is inverted;

[0024] Figure 2 is a cross-sectional view from a first viewing angle of the present invention;

[0025] Figure 3 It is a schematic diagram of the structure of the connection column and the two gears;

[0026] Figure 4 It is a cross-sectional view of the connection column and the two gears;

[0027] Figure 5 It is a schematic diagram of the structure of the connection column and the two ratchets;

[0028] Figure 6 It is a schematic diagram of the structure of the connection column, a set of non-return pawls and arc-shaped metal springs;

[0029] Figure 7 It is a schematic diagram of the structure of the ratchet and the connecting ring;

[0030] Figure 8 It is a structural schematic diagram of a double circular arc helical gear;

[0031] Fig. 9 It is a schematic diagram of the structure of the first connecting plate and the double-arc helical rack.

[0032] Among them, 1. box body; 2. cylinder body; 3. steering assembly; 4. connecting column; 5. mounting groove; 6. supporting column; 7. non-return pawl; 8. arc-shaped metal spring; 9. ratchet; 10. double arc bevel gear; 11. spur gear; 12. trapezoidal limit ring; 13. connecting ring; 14. plug plate; 15. through groove; 16. first driving member; 17. second driving member; 18. first piston; 19. first connecting plate; 20. double arc bevel gear rack; 21. second piston; 22. second connecting plate; 23. spur gear rack; 24. slot; 25. slide groove; 26. block; 27. spring; 28. first air port; 29. ​​second air port; 30. third air port; 31. fourth air port; 32. transmission shaft; 33. mounting plate. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Examples, such as Figure 1 - Fig. 9 As shown, the embodiment of the present invention provides a three-stage pneumatic actuator with precise positioning, including a box body 1, cylinder bodies 2 are fixedly installed on both sides of the box body 1, a steering assembly 3 is fixedly installed in the box body 1, a first driving member 16 is slidably matched in one cylinder body 2, and a second driving member 17 is slidably matched in the other cylinder body 2;

[0035] Specifically, the steering assembly 3 includes a connecting column 4 that is rotatably engaged with the box body 1, and two groups of mounting grooves 5 are opened on the side surface of the connecting column 4 in a circular array. Two symmetrical support columns 6 are fixedly connected in the mounting grooves 5. A non-return pawl 7 is rotatably engaged on the side surface of one support column 6, and an arc-shaped metal spring piece 8 is fixedly sleeved on the side surface of the other support column 6. The arc-shaped metal spring piece 8 is located between the non-return pawl 7 and the mounting groove 5, and the arc-shaped metal spring piece 8 is pressed against one side of the non-return pawl 7 so that one end of the non-return pawl 7 is always located outside the mounting groove 5.

[0036] The connecting column 4 is rotatably matched with two ratchet wheels 9 to form two sets of ratchet and pawl mechanisms. Figure 5As shown, since the non-return pawl 7 is inserted into the teeth of the ratchet 9, when one of the ratchets 9 rotates clockwise, the teeth of the ratchet 9 will exert a tangential force on the non-return pawl 7. Under the action of this tangential force, the ratchet 9 can drive the non-return pawl 7 to rotate in the same direction, and the non-return pawl 7 drives the connecting column 4 to rotate through the supporting column 6 that rotates with it. When the connecting column 4 rotates, it will drive the other group of non-return pawls 7 to rotate in the same direction. However, in this case, this group of non-return pawls 7 will slide along the inclined surface of the teeth of the ratchet 9, and due to the elastic effect of the arc-shaped metal spring sheet 8, the non-return pawl 7 will swing back and forth around the supporting column 6 that rotates with it during the sliding process. In this process, this group of non-return pawls 7 will not drive the other ratchet 9 to rotate in the same direction. This design enables the two ratchets 9 to function independently under different working conditions.

[0037] The side surfaces of the connecting column 4 are fixedly connected to the other ends of the two ratchets 9 with a trapezoidal limiting ring 12 , and the other ends of the ratchets 9 are fixedly connected to a connecting ring 13 rotatably matched with the trapezoidal limiting ring 12 , and the trapezoidal limiting ring 12 provides support and limiting effect for the ratchets 9 .

[0038] The side surface of the connecting column 4 is located at one end of a ratchet 9 and is rotatably matched with a double circular arc bevel gear 10, and the side surface of the connecting column 4 is located at one end of another ratchet 9 and is rotatably matched with a spur cylindrical gear 11. The module and number of teeth of the spur cylindrical gear 11 are greater than those of the double circular arc bevel gear 10. When the spur cylindrical gear 11 and the double circular arc bevel gear 10 are respectively matched with corresponding racks, then when the two racks respectively drive the spur cylindrical gear 11 and the double circular arc bevel gear 10 to rotate the same angle, the linear motion stroke of the rack matched with the spur cylindrical gear 11 will be greater than the linear motion stroke of the rack matched with the double circular arc bevel gear 10.

[0039] One end of the ratchet 9 is fixedly connected to a plurality of plug plates 14 in a circular array, and one end of the double arc bevel gear 10 and the spur gear 11 are penetrated by a plurality of through grooves 15 in a circular array. The through grooves 15 are slidably matched with the plug plates 14, so that the two ratchets 9 will rotate synchronously with the corresponding spur gears 11 or double arc bevel gears 10.

[0040] The first driving member 16 includes a first piston 18 that is slidably matched with a cylinder body 2, one end of the first piston 18 is fixedly connected to a first connecting plate 19, the first connecting plate 19 and the cylinder body 2 are slidably matched, one end of the first connecting plate 19 is fixedly connected to a double arc helical rack 20, the double arc helical rack 20 is meshed with the double arc helical gear 10, a first gas port 28 is provided near one end of one side of the cylinder body 2, and a second gas port 29 is provided near the other end of one side of the cylinder body 2, the first gas port 28 and the second gas port 29 are both connected to the cylinder body 2, and compressed gas is introduced into the cavity on the side of the first piston 18 in the cylinder body 2 through the first gas port 28, so that the first piston 18 moves in the cylinder body 2. The other side slides, and the gas in the cavity on the other side is discharged through the second air port 29. When the first piston 18 slides, it will drive the double-arc helical rack 20 to move synchronously through the first connecting plate 19. When the double-arc helical rack 20 is meshed with the double-arc helical gear 10, since the tooth surface is spiral, in addition to the circumferential force for transmitting torque, an axial force will also be generated. When the double-arc helical rack 20 moves to one side, an axial force will be generated. This axial force will cause the double-arc helical gear 10 to move axially upward or downward. When the double-arc helical rack 20 moves to the other side, the direction of the axial force will change. The change in the direction of the axial force will cause the double-arc helical gear 10 to move axially in the opposite direction.

[0041] The second driving member 17 includes a second piston 21 that is slidably matched with the other cylinder body 2. One end of the second piston 21 is fixedly connected to a second connecting plate 22. The second connecting plate 22 penetrates and slides with the other cylinder body 2. One end of the second connecting plate 22 is fixedly connected to a spur rack 23. The spur rack 23 meshes with the spur cylindrical gear 11. A third air port 30 is provided near one end of the other cylinder body 2. A fourth air port 31 is provided near the other end of the other cylinder body 2. The third air port 30 , and the fourth air port 31 are both connected to the other cylinder body 2. Compressed gas is introduced into the cavity on the side of the first piston 18 in the one cylinder body 2 through the third air port 30, so that the second piston 21 slides to the other side in the other cylinder body 2, and the gas in the cavity on the other side is discharged through the fourth air port 31. When the second piston 21 slides, it will drive the spur rack 23 to move synchronously through the second connecting plate 22. When the spur rack 23 is meshed with the spur cylindrical gear 11, the spur rack 23 will drive the spur rack 23 to rotate.

[0042] A plurality of slots 24 are provided in a circular array on the side surface of the connecting column 4 between the two groups of mounting slots 5, and a plurality of slide grooves 25 are provided in a circular array on the inner side surface of the double circular arc bevel gear 10. A block 26 is slidably fitted in the slide groove 25, and a spring 27 is fixedly connected to one end of the block 26 in the slide groove 25. In the initial state, the block 26 is located in the slide groove 25, and the spring 27 is in a compressed state. When the double circular arc bevel gear 10 moves upward and the ratchet 9 located below continues to rotate counterclockwise, the slide groove 25 will meet the slot 24, which allows the compressed spring 27 to rebound, and the spring 27 will drive one end of the block 26 to move from the inside of the slide groove 25 to the inside of the slot 24. If the ratchet 9 continues to rotate counterclockwise, the ratchet 9 will transmit the torque to the connecting column 4 through the block 26, so that the connecting column 4 starts to rotate in the same direction.

[0043] One end of the connecting column 4 is fixedly connected to a transmission shaft 32, and a mounting plate 33 is fixedly connected to the side surface of the transmission shaft 32. The transmission shaft 32 is connected to the valve control shaft of the ball valve or butterfly valve to transmit torque for controlling the opening of the valve. The mounting plate 33 is used to fix the actuator on the ball valve or butterfly valve.

[0044] Working principle: first connect the valve control shaft of the ball valve or butterfly valve to the transmission shaft 32, and then fix the actuator on the ball valve or butterfly valve through the mounting plate 33. When the valve needs to be opened at a set angle, the compressed gas is introduced into the cavity on one side of the first piston 18 in the cylinder body 2 through the first air port 28, so that the first piston 18 slides to the other side in the cylinder body 2, and the gas in the cavity on the other side is discharged through the second air port 29. When the first piston 18 slides, it will drive the double arc helical rack 20 to move synchronously through the first connecting plate 19. At this time, the double arc helical rack 20 will give the double arc helical gear 10 a downward axial force However, under the position restriction of the trapezoidal limiting ring 12 located below, the double-arc bevel gear rack 20 will not move downward, and the double-arc bevel gear rack 20 will only drive the double-arc bevel gear 10 to rotate clockwise, and the double-arc bevel gear 10 drives the ratchet 9 below it to rotate clockwise through the plug plate 14. At this time, the teeth of the ratchet 9 will exert a tangential force on the non-return pawl 7. Under the action of this tangential force, the ratchet 9 can drive the non-return pawl 7 to rotate in the same direction, and the non-return pawl 7 drives the connecting column 4 to rotate through the supporting column 6 that rotates with it, and the connecting column 4 drives the valve to rotate through the transmission shaft 32 until the valve When the rotation angle reaches a predetermined angle (the predetermined angle should be less than the set angle), the compressed gas is stopped from being introduced into the first cylinder 2, so that the first piston 18 is in a stationary state, and then the compressed gas is introduced into the cavity on one side of the first piston 18 in the first cylinder 2 through the third gas port 30, so that the second piston 21 slides to the other side in the other cylinder 2, and the second piston 21 drives the spur rack 23 to move synchronously through the second connecting plate 22, and the spur rack 23 drives the spur gear 11 meshing with it to rotate clockwise, and the spur gear 11 drives the ratchet 9 below it to rotate clockwise through the plug plate 14, and the ratchet 9 The check pawl 7 is driven to rotate in the same direction, and the check pawl 7 drives the connecting column 4 to rotate through the supporting column 6 that rotates with it, and the connecting column 4 drives the valve to rotate clockwise through the transmission shaft 32, so that the valve rotates to the position where the set angle is located. Since the module and the number of teeth of the spur gear 11 are greater than the double arc bevel gear 10, when the two sets of gear racks are normally meshed and the spur gear rack 23 and the double arc bevel gear rack 20 move the same distance, the rotation angle of the spur gear 11 is smaller than the double arc bevel gear 10. Therefore, these two non-interfering sequential controls will improve the positioning accuracy of the pneumatic actuator.

[0045] When the valve is reset, compressed gas is first introduced into the other cylinder 2 through the fourth gas port 31 to reset the spur rack 23. The spur rack 23 does not drive the connecting column 4 to rotate during the reset process. Then, compressed gas is introduced into one cylinder 2 through the second gas port 29, and when the first gas port 28 is exhausted, the first piston 18 drives the double circular arc helical rack 20 to move in the opposite direction. At this time, the double circular arc helical rack 20 gives an upward axial force to the double circular arc helical gear 10, causing the double circular arc helical gear 10 to rotate. When the double circular arc bevel gear 10 contacts the trapezoidal limit ring 12 at the top, it will stop moving upward, and because the ratchet 9 at the bottom continues to rotate counterclockwise, the slide groove 25 will meet the clamping groove 24, which allows the compressed spring 27 to rebound, and the spring 27 will drive one end of the clamping block 26 to slide from the inside of the slide groove 25 into the inside of the clamping groove 24. If the ratchet 9 continues to rotate counterclockwise, the ratchet 9 will transmit the torque to the connecting column 4 through the clamping block 26, causing the connecting column 4 to start rotating counterclockwise until the valve is closed.

[0046] 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 three-stage pneumatic actuator with precise positioning, comprising a box (1), with cylinders (2) fixedly mounted on both sides of the box (1), characterized in that: A steering assembly (3) is fixedly installed in the box (1), a first driving member (16) is slidably fitted in one of the cylinders (2), and a second driving member (17) is slidably fitted in the other of the cylinders (2); The steering assembly (3) comprises a connecting column (4) rotatably matched with the box body (1), the connecting column (4) is provided with two groups of mounting grooves (5) in a circumferential array on its circumferential side surface, two symmetrical support columns (6) are fixedly connected in the mounting grooves (5), a non-return pawl (7) is rotatably matched on the circumferential side surface of one of the support columns (6), and an arc-shaped metal spring sheet (8) is fixedly sleeved on the circumferential side surface of the other support column (6), and the arc-shaped metal spring sheet (8) is located between the non-return pawl (7) and the mounting groove (5); The side surface of the connecting column (4) is rotatably matched with two ratchets (9), the side surface of the connecting column (4) is located at one end of the ratchet (9) and is rotatably matched with a double circular arc bevel gear (10), and the side surface of the connecting column (4) is located at one end of the other ratchet (9) and is rotatably matched with a spur gear (11), the module and the number of teeth of the spur gear (11) are both greater than the double circular arc bevel gear (10).

2. A three-stage pneumatic actuator with precise positioning according to claim 1, characterized in that: The side surface of the connection column (4) is fixedly connected to a trapezoidal limiting ring (12) at the other end of the two ratchets (9), and the other end of the ratchet (9) is fixedly connected to a connecting ring (13) that rotatably cooperates with the trapezoidal limiting ring (12).

3. A three-stage pneumatic actuator with precise positioning according to claim 2, characterized in that: One end of the ratchet (9) is fixedly connected to a plurality of plug plates (14) in a circumferential array, and one end of the double arc bevel gear (10) and the spur gear (11) are both provided with a plurality of through grooves (15) in a circumferential array, and the through grooves (15) are slidably matched with the plug plates (14).

4. The three-stage pneumatic actuator with precise positioning according to claim 3, characterized in that: The first driving member (16) comprises a first piston (18) which is slidably matched with the cylinder body (2); one end of the first piston (18) is fixedly connected with a first connecting plate (19); the first connecting plate (19) penetrates and slidably matches with the cylinder body (2); one end of the first connecting plate (19) is fixedly connected with a double-arc helical gear rack (20); the double-arc helical gear rack (20) is meshed with the double-arc helical gear (10).

5. A three-stage pneumatic actuator with precise positioning according to claim 4, characterized in that: The second driving member (17) comprises a second piston (21) which is slidably matched with the other cylinder body (2); one end of the second piston (21) is fixedly connected to a second connecting plate (22); the second connecting plate (22) penetrates and slidably matches with the other cylinder body (2); one end of the second connecting plate (22) is fixedly connected to a spur rack (23); the spur rack (23) is meshed with the spur cylindrical gear (11).

6. A three-stage pneumatic actuator with precise positioning according to claim 5, characterized in that: The peripheral side surface of the connecting column (4) is located between the two groups of mounting grooves (5) and is provided with a plurality of slots (24) in a circular array.

7. A three-stage pneumatic actuator with precise positioning according to claim 6, characterized in that: The inner circumferential side surface of the double circular arc bevel gear (10) is provided with a plurality of slide grooves (25) in a circumferential array, a clamping block (26) is slidably fitted in the slide groove (25), and a spring (27) is fixedly connected to one end of the clamping block (26) in the slide groove (25).

8. The three-stage pneumatic actuator with precise positioning according to claim 7, characterized in that: A first air port (28) is provided on one side of the cylinder body (2) near one end thereof, and a second air port (29) is provided on one side of the cylinder body (2) near the other end thereof. Both the first air port (28) and the second air port (29) are in communication with the cylinder body (2).

9. A three-stage pneumatic actuator with precise positioning according to claim 8, characterized in that: A third air port (30) is provided on one side of the other cylinder body (2) near one end thereof, and a fourth air port (31) is provided on one side of the other cylinder body (2) near the other end thereof, and the third air port (30) and the fourth air port (31) are both in communication with the other cylinder body (2).

10. The three-stage pneumatic actuator with precise positioning according to claim 9, characterized in that: One end of the connecting column (4) is fixedly connected to a transmission shaft (32), and a mounting plate (33) is fixedly connected to a peripheral side surface of the transmission shaft (32).

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