Large-torque pneumatic actuator

Abstract

The large-torque pneumatic actuator comprises a spring cylinder, a cover plate is arranged on one side of the spring cylinder, a spring seat is arranged on one side of the inner wall of the spring cylinder, a spring set is fixedly connected to one side of the spring seat, a piston rod is connected to the middle of the spring seat in an inserted mode, and a box is connected to one side of the spring cylinder in a bolted mode. The stability and the positioning precision of the piston rod can be ensured through the arranged positioning guide mechanism, the inner wall of the piston body is connected with the outer wall of the key groove in a penetrating mode, the inner wall of the key groove is connected with the outer wall of the clamping key in a clamped mode, and one side of the piston body is tightly attached to one side of the elastic check ring and connected with one side of the piston rod through a nut on one side of the piston rod. Through the connection arrangement, the problem that a piston rod of a traditional actuator deflects under the high pressure difference can be effectively solved; and by arranging the detachable fixing mechanism, the device can be conveniently maintained, the piston rod can be conveniently replaced, the service life of the actuator is prolonged, the maintenance efficiency of the actuator is improved, and the maintainability of the product is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pneumatic actuators, in particular to a large-torque pneumatic actuator. Background Technique

[0002] There are two types of transmission mechanisms for pneumatic actuators, namely the gear-rack type and the fork type. The fork-type pneumatic actuator drives the fork to rotate through the linear motion of the piston rod, and then drives the main shaft or valve stem to rotate. It is a stroke piston type actuator and can be used for the on-off control of valves with a 90° rotation angle.

[0003] Patent CN204459387U discloses a modular integrated fork-type pneumatic actuator, which includes a pneumatic module, a torque module, and a spring module. A pneumatic module connecting plate is provided on the pneumatic module, a spring module connecting plate is provided on the spring module, and the torque module is connected to the pneumatic module connecting plate and the spring module connecting plate by snap-fastening and is fastened to the pneumatic module and the spring module through fasteners. The mechanical step snap-fastening design is adopted between the modules to position the connection between the modules, and the structure is more stable.

[0004] At present, only one piston rod is connected to the traditional piston. Although there is a certain contact width between its outer periphery and the inner wall of the cylinder body, which has a certain anti-deviation effect, the effect is limited after all. When the pressure difference on both sides of the piston is too large, deflection may still occur, and the positioning effect is not good. Content of the Utility Model

[0005] The purpose of the utility model is to provide a large-torque pneumatic actuator to solve the problem that only one piston rod is connected to the piston in the above-mentioned background technique. Although there is a certain contact width between its outer periphery and the inner wall of the cylinder body, which has a certain anti-deviation effect, the effect is limited after all. When the pressure difference on both sides of the piston is too large, deflection may still occur, and the positioning effect is not good.

[0006] To achieve the above purpose, the utility model provides the following technical solution: A large-torque pneumatic actuator, including a spring cylinder, a cover plate is arranged on one side of the spring cylinder, a spring seat is arranged on one side of the inner wall of the spring cylinder, a spring group is fixedly connected to one side of the spring seat, a piston rod is inserted in the middle of the spring seat, a box body is bolted to one side of the spring cylinder, a positioning and guiding mechanism is bolted to one side of the box body, a cylinder body is bolted to one side of the positioning and guiding mechanism, a detachable fixing mechanism is detachably connected to the outer wall of the piston rod, an end cover is bolted to one side of the cylinder body, a lifting ring screw is threadedly connected to the upper end of the box body, and a fork assembly is fixedly connected to the middle of the box body;

[0007] The positioning and guiding mechanism includes an inner cover. One side of the inner cover is bolted to one side of the box body. There is a positioning table on one side of the inner cover. Connecting counterbores are provided at both ends of the positioning table. A pull rod is slidably connected to the inner wall of the connecting counterbore. An inner hexagonal hole is fixedly connected to one side of the pull rod. A threaded section is provided on the outer wall of the inner hexagonal hole. A relief hole is penetratingly provided in the middle of the end cover.

[0008] Preferably, one side of the cover plate is bolted to one side of the spring cylinder, and the outer wall of the spring seat is fixedly connected to the inner wall of the spring cylinder.

[0009] Preferably, one side of the inner cover is fixedly connected to one side of the positioning table, and both ends of the positioning table are penetratingly connected to the outer wall of the connecting counterbore.

[0010] Preferably, one end of the inner hexagonal hole penetrates through the end cover and is threadedly connected by a nut.

[0011] Preferably, the detachable fixing mechanism includes a piston body. The inner wall of the piston body is detachably connected to the outer wall of the piston rod. A keyway is provided on the inner wall of the piston body. A key is provided on the inner wall of the keyway. An elastic retaining ring is movably connected to one side of the key. Positioning through holes are provided at both ends of the inner wall of the piston body.

[0012] Preferably, the inner wall of the piston body is penetratingly connected to the outer wall of the keyway, and the inner wall of the keyway is engaged with the outer wall of the key.

[0013] Preferably, one side of the piston body is closely attached to one side of the elastic retaining ring and is connected by a nut on one side of the piston rod.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1. By setting the positioning and guiding mechanism, the equipment can ensure the stability and positioning accuracy of the piston rod. The inner wall of the piston body is penetratingly connected to the outer wall of the keyway, the inner wall of the keyway is engaged with the outer wall of the key, and one side of the piston body is closely attached to one side of the elastic retaining ring and is connected by a nut on one side of the piston rod. Through this connection setting, the problem of the piston rod deflection of the traditional actuator under high pressure difference can be effectively solved, and at the same time, the stability and reliability of the actuator are ensured. The outer end of the pull rod penetrates through the end cover, and a nut is engaged on its threaded section for fixed limit. The nut exerts a pressure towards the box body direction on the end cover, so that the cylinder body is clamped between the inner cover and the end cover to form a fixed connection. By adding a spring group and a fork assembly, the actuator can provide a greater torque output to meet the use requirements under different working conditions;

[0016] 2. By setting the detachable fixing mechanism, the equipment can facilitate the maintenance and replacement of the piston rod, improve the service life and maintenance efficiency of the actuator, and improve the maintainability of the product. Brief Description of the Drawings

[0017] Figure 1 is a schematic cross-sectional view of the three-dimensional structure of the present utility model;

[0018] Figure 2 is a schematic diagram of the positioning and guiding mechanism of the present utility model;

[0019] Figure 3 is a schematic diagram of the detachable fixing mechanism of the present utility model;

[0020] Figure 4 is a schematic three-dimensional structure diagram of the present utility model;

[0021] Figure 5 is a side cross-sectional view of the three-dimensional structure of the present utility model.

[0022] In the figures: 1. Spring cylinder; 2. Cover plate; 3. Spring seat; 4. Spring group; 5. Piston rod; 6. Box body; 7. Positioning and guiding mechanism; 8. Cylinder block; 9. Detachable fixing mechanism; 10. End cover; 11. Hoisting ring screw; 12. Fork assembly; 71. Inner cover; 72. Positioning table; 73. Connecting counterbore; 74. Pull rod; 75. Hexagon socket head; 76. Thread section; 77. Relief hole; 91. Piston body; 92. Keyway; 93. Key; 94. Circlip; 95. Positioning through hole. Detailed Description of the Preferred Embodiment

[0023] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0024] Please refer to Figure 1 、 Figure 4 and Figure 5, the present utility model provides a technical solution: a high-torque pneumatic actuator, which includes a spring cylinder 1. A cover plate 2 is arranged on one side of the spring cylinder 1. A spring seat 3 is arranged on one inner wall side of the spring cylinder 1. A spring group 4 is fixedly connected to one side of the spring seat 3. A piston rod 5 is inserted in the middle of the spring seat 3. A box body 6 is bolted to one side of the spring cylinder 1. A positioning and guiding mechanism 7 is bolted to one side of the box body 6. A cylinder block 8 is bolted to one side of the positioning and guiding mechanism 7. A detachable fixing mechanism 9 is detachably connected to the outer wall of the piston rod 5. A end cover 10 is bolted to one side of the cylinder block 8. A lifting eye screw 11 is threadedly connected to the upper end of the box body 6. A fork assembly 12 is fixedly connected to the middle of the box body 6. The positioning and guiding mechanism 7 includes an inner cover 71. One side of the inner cover 71 is bolted to one side of the box body 6. A positioning table 72 is arranged on one side of the inner cover 71. Connecting counterbores 73 are arranged at both ends of the positioning table 72. A pull rod 74 is slidably connected to the inner wall of the connecting counterbore 73. An internal hexagonal hole 75 is fixedly connected to one side of the pull rod 74. A threaded section 76 is arranged on the outer wall of the internal hexagonal hole 75. A relief hole 77 is penetrated through the middle of the end cover 10. One side of the cover plate 2 is bolted to one side of the spring cylinder 1. The outer wall of the spring seat 3 is fixedly connected to the inner wall of the spring cylinder 1;

[0025] By providing a screw hole on the end cover 10, an internal hexagonal tool can be inserted through the screw hole to cooperate with the internal hexagonal hole 75 at the end of the piston rod 5 inside the cylinder block 8, achieving the effect of quickly and conveniently screwing the piston rod 5. An external hexagonal plug is engaged on the screw hole to seal the internal structure. If the cylinder block 8 is a single-acting cylinder, removing the external hexagonal plug can connect the inner space of the cylinder block 8 with the outside. A relief hole 77 is provided on the positioning table 72. When the piston body 91 on the piston rod 5 moves to the end cover 10, the end of the piston rod 5 enters the relief hole 77 and is relieved, extending the telescopic stroke of the piston rod 5. The pull rod 74 extends outside the end cover 10, and a sealing ring is provided between the pull rod 74 and the end cover 10, making the sealing effect more reliable. The setting of two annular key grooves 92 and two groups of arc-shaped key blocks 93. The key grooves 92 are circumferentially provided on the piston rod 5 and are respectively located on both sides of the piston body 91. The width of the key block 93 is adapted to the width of the key groove 92. The key block 93 encloses the key groove 92, and its circumferential outer side is tightened and limited by an elastic retaining ring 94. The front and rear sides of the piston body 91 are in contact with the inner side of the key block 93.

[0026] Please refer to Figure 2 , in order to quickly guide the piston body 91 on the piston rod 5, one side of the inner cover 71 is fixedly connected to one side of the positioning table 72. Both ends of the positioning table 72 are penetrated and connected to the outer wall of the connecting counterbore 73. One end of the internal hexagonal hole 75 penetrates through the end cover 10 and is threadedly connected by a nut;

[0027] A connecting hole is provided in the middle of the piston body 91, which is convenient for being mounted on the piston rod 5 to ensure uniform force. A keyway 92 is provided on the piston rod 5. The width between the keyways 92 is adapted to the length of the positioning through hole 95. A group of latching keys 93 are enclosed on the keyway 92 and are closed and fixed by elastic retaining rings 94. The outer diameter of the latching keys 93 is larger than the positioning through hole 95, so that the piston body 91 is clamped between the latching keys 93, completing the fixation between the piston rod 5 and the piston body 91, making the connection method easy to disassemble and assemble. A small hole is provided at the end of the elastic retaining ring 94, and an iron wire can be passed through the small hole to further ensure that the latching keys 93 are stably enclosed on the piston rod 5.

[0028] See also Figure 3 In order to quickly fix the piston body 91 on the piston rod 5, the detachable fixing mechanism 9 includes a piston body 91, the inner wall of the piston body 91 is detachably connected to the outer wall of the piston rod 5, the inner wall of the piston body 91 is provided with a keyway 92, the inner wall of the keyway 92 is provided with a card key 93, one side of the card key 93 is movably connected with an elastic retaining ring 94, and both ends of the inner wall of the piston body 91 are provided with positioning through holes 95, the inner wall of the piston body 91 is connected with the outer wall of the keyway 92, the inner wall of the keyway 92 is connected with the outer wall of the card key 93, and one side of the piston body 91 is tightly attached to one side of the elastic retaining ring 94 and connected through a nut on one side of the piston rod 5;

[0029] The compressed gas is passed into the cylinder 8, and the pressure difference drives the piston body 91 to move axially. The piston body 91 slides on the pull rod 74, and the piston rod 5 connected to the piston body 91 also moves axially synchronously. The piston rod 5 simultaneously drives the fork assembly to move, and the indicator shaft rotates to achieve the effect of shifting the valve stem. At the same time, the spring group 4 in the spring cylinder 1 is compressed. When no driving force is provided, the spring group 4 on the spring seat 3 in the spring cylinder 1 releases elastic potential energy, drives the piston rod 5 to move axially, and reversely shifts the fork assembly, that is, reversely shifts the valve stem.

[0030] Working principle: First, a screw hole is provided on the end cover 10, through which a hexagonal tool can be inserted to cooperate with the hexagonal hole 75 at the end of the piston rod 5 in the cylinder body 8, so as to achieve the effect of quickly and conveniently cooperating to twist the piston rod 5, and the outer hexagonal screw plug is engaged on the screw hole to achieve the sealing of the internal structure. If the cylinder body 8 is a single-acting cylinder, the outer hexagonal screw plug can be removed to connect the inner space of the cylinder body 8 with the outside world. A clearance hole 77 is provided on the positioning platform 72. When the piston body 91 moves to the bottom toward the end cover 10, the end of the piston rod 5 enters the clearance hole 77 and is given way, extending the telescopic stroke of the piston rod 5. The pull rod 74 extends out of the outside of the end cover 10, and a sealing ring is provided between the pull rod 74 and the end cover 10, so that the sealing effect is more reliable. Two annular keyways 92 and two sets of arc-shaped card keys 93 are provided, and the keyways 92 are circumferentially opened on the piston rod 5 and are respectively located at the movable On both sides of the plug body 91, the width of the key 93 is adapted to the width of the key slot 92, the key 93 is enclosed in the key slot 92, and its circumferential outer side is clamped and limited by an elastic retaining ring 94, the front and rear sides of the piston body 91 are in contact with the inner side of the key 93, and a connecting hole is opened in the middle of the piston body 91, which is convenient for sleeved on the piston rod 5 to make the force uniform. The piston rod 5 is provided with a key slot 92, and the width between the key slots 92 is adapted to the length of the positioning through hole 95. A group of keys 93 are enclosed on the key slot 92 and are closed and fixed by an elastic retaining ring 94. The outer diameter of the key 93 is larger than the positioning through hole 95, so that the piston body 91 is clamped between the key 93, and the fixation between the piston rod 5 and the piston body 91 is completed, so that the connection method is convenient for disassembly and assembly, and a small hole is provided at the end of the elastic retaining ring 94, and a wire can also be passed through the small hole to further ensure that the key 93 is stably enclosed on the piston rod 5;

[0031] Then, during actual operation, compressed gas is generated and passed into the cylinder body 8, and the pressure difference drives the piston body 91 to move axially. The piston body 91 slides on the pull rod 74, and the piston rod 5 connected to the piston body 91 also moves axially synchronously. The piston rod 5 simultaneously drives the fork assembly to move, and rotates the indicating shaft to achieve the effect of shifting the valve stem. At the same time, the spring group 4 in the spring cylinder 1 is compressed. When no driving force is provided, the spring group 4 on the spring seat 3 in the spring cylinder 1 releases elastic potential energy, drives the piston rod 5 to move axially, and reversely shifts the fork assembly, that is, reversely shifts the valve stem. The above is the working process of the entire device, and the contents not described in detail in this specification belong to the existing technology well known to professional and technical personnel in this field.

[0032] Although the 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 high torque pneumatic actuator, comprising a spring cylinder (1), characterized in that: A cover plate (2) is provided on one side of the spring cylinder (1), a spring seat (3) is provided on one side of the inner wall of the spring cylinder (1), a spring group (4) is fixedly connected to one side of the spring seat (3), a piston rod (5) is inserted in the middle of the spring seat (3), a box body (6) is bolted to one side of the spring cylinder (1), a positioning guide mechanism (7) is bolted to one side of the box body (6), a cylinder body (8) is bolted to one side of the positioning guide mechanism (7), a detachable fixing mechanism (9) is detachably connected to the outer wall of the piston rod (5), an end cover (10) is bolted to one side of the cylinder body (8), a lifting eye screw (11) is threadedly connected to the upper end of the box body (6), and a fork assembly (12) is fixedly connected to the middle of the box body (6); The positioning guide mechanism (7) includes an inner cover (71), one side of the inner cover (71) is bolted to one side of the box body (6), a positioning platform (72) is provided on one side of the inner cover (71), connecting countersunk holes (73) are provided at both ends of the positioning platform (72), the inner wall of the connecting countersunk hole (73) is slidably connected to a pull rod (74), one side of the pull rod (74) is fixedly connected to a hexagonal hole (75), the outer wall of the hexagonal hole (75) is provided with a threaded section (76), and a clearance hole (77) is provided through the middle of the end cover (10).

2. A high torque pneumatic actuator according to claim 1, characterized in that: One side of the cover plate (2) is bolted to one side of the spring cylinder (1), and the outer wall of the spring seat (3) is fixedly connected to the inner wall of the spring cylinder (1).

3. A high torque pneumatic actuator according to claim 1, characterized in that: One side of the inner cover (71) is fixedly connected to one side of the positioning platform (72), and both ends of the positioning platform (72) are connected through the outer wall of the connecting countersunk hole (73).

4. A high torque pneumatic actuator according to claim 3, characterized in that: One end of the hexagonal hole (75) passes through the end cover (10) and is threadedly connected via a nut.

5. A high torque pneumatic actuator according to claim 1, characterized in that: The detachable fixing mechanism (9) comprises a piston body (91), the inner wall of the piston body (91) is detachably connected to the outer wall of the piston rod (5), the inner wall of the piston body (91) is provided with a keyway (92), the inner wall of the keyway (92) is provided with a key (93), one side of the key (93) is movably connected to an elastic retaining ring (94), and positioning through holes (95) are provided at both ends of the inner wall of the piston body (91).

6. A high torque pneumatic actuator according to claim 5, characterized in that: The inner wall of the piston body (91) is connected through the outer wall of the keyway (92), and the inner wall of the keyway (92) is connected by snapping with the outer wall of the key (93).

7. A high torque pneumatic actuator according to claim 5, characterized in that: One side of the piston body (91) is in close contact with one side of the elastic retaining ring (94) and is connected via a nut on one side of the piston rod (5).

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