Maintenance device and maintenance method for single-action shifting fork type pneumatic actuator

Abstract

The invention discloses a maintenance device and method for a single-action shifting fork type pneumatic actuator, and relates to the technical field of maintenance of pneumatic actuators. The maintenance device comprises a supporting base and an axial pushing device, and a target actuating mechanism is placed on the supporting base; the target executing mechanism comprises a rear cylinder cover at the end and an internal spring assembly, the axial pushing device comprises a limiting plate, a second jacking mechanism and a plurality of axial driving lead screws, the limiting plate is located on the outer side of the rear cylinder cover, one end of each axial driving lead screw is connected to the target executing mechanism, and the other end of each axial driving lead screw penetrates through the rear cylinder cover and the limiting plate; the axial driving lead screw is further in threaded connection with a first nut and a second nut, the first nut abuts against the outer side of the rear cylinder cover, the second nut abuts against the outer side of the limiting plate, the second jacking mechanism is located between the limiting plate and the rear cylinder cover, the rear cylinder cover is pushed to move towards the target executing mechanism, and the spring assembly is continuously pressed inwards. The cylinder cover is convenient to operate, and compared with manual pushing of the cylinder cover, the effect of reducing manpower consumption is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic actuator maintenance, and in particular to a maintenance device and a maintenance method for a single-acting scotch yoke type pneumatic actuator. Background Art

[0002] Valves can be divided into three types according to the different energy sources: pneumatic valves, hydraulic valves and electric valves. Pneumatic actuators are the actuators of pneumatic valves, which are actuators that use air pressure to drive the opening, closing or regulating of valves. The scotch fork pneumatic actuator is a type of piston actuator, which is mainly composed of a cylinder, a piston, a scotch fork, an output shaft, a spring, a screw and an air source interface. Its main working principle is: the piston in the cylinder makes a linear motion, and the scotch fork is connected to the piston by a U-shaped groove, converting the linear motion of the piston into the rotational motion of the output shaft. The O-ring used for piston sealing is easy to wear due to periodic reciprocating motion, and the cylinder needs to be disassembled frequently for replacement.

[0003] When disassembling, replacing and resetting the valve, the axial thrust of the spring in the cylinder makes it difficult to install the rear cylinder head into place. It is usually necessary to push the rear cylinder head manually and then continuously turn the lead screw, pushing it a little and turning it a little. This installation method is firstly very time-consuming and labor-intensive, and secondly, it is easy to cause the lead screw to slip, affecting the normal use of the valve. At the same time, the huge axial pressure after slippage will threaten the safety of personnel at the rear cylinder head. Summary of the invention

[0004] The purpose of the present invention is to provide a maintenance device and a maintenance method for a single-acting scotch fork pneumatic actuator, which is easy to operate, saves time and effort, and greatly reduces manpower consumption compared to manually pushing the cylinder head.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A maintenance device for a single-acting scotch fork type pneumatic actuator comprises a support base and an axial pushing device, wherein a target actuator is placed on the support base; the target actuator comprises a rear cylinder cover at the end and an internal spring assembly, the axial pushing device comprises a limit plate, a second lifting mechanism and a plurality of axial drive screws, the limit plate is located on the outside of the rear cylinder cover, one end of the axial drive screw is connected to the target actuator, and the other end passes through the rear cylinder cover and the limit plate, the axial drive screw is also threadedly connected with a first nut and a second nut, the first nut abuts against the outside of the rear cylinder cover, and the second nut abuts against the outside of the limit plate, the second lifting mechanism is located between the limit plate and the rear cylinder cover, and pushes the rear cylinder cover to move toward the target actuator, thereby continuously pressing the spring assembly inward.

[0006] Furthermore, the second lifting mechanism includes a second jack.

[0007] Furthermore, a second buffer block is provided between the second jack and the rear cylinder head.

[0008] Furthermore, the support base is connected to a plurality of first lifting mechanisms, and the target actuator includes a main mechanism body and an outer cylinder body. The outer cylinder tube of the cylinder body is detachably connected to one end of the main body, the rear cylinder cover is arranged on the outer end of the outer cylinder tube of the cylinder body, the main body is placed on the support base, the outer cylinder tube of the cylinder body is placed on the first lifting mechanism, and is lifted and lowered by the first lifting mechanism to engage with the main body in place.

[0009] Furthermore, the first lifting mechanism includes a first jack.

[0010] Furthermore, the target actuator and the rear cylinder cover are provided with a plurality of holes for connecting the original screw rods and connecting the rear cylinder cover and the target actuator to each other. During maintenance, all the holes are divided into at least two groups. An axial drive screw is installed in one set of holes, which passes through the rear cylinder cover and is connected to the limit plate. The original screw is installed in another set of holes. After it is in place, the axial drive screw is replaced with the original screw.

[0011] Furthermore, it also includes an upper balancing member, which is connected to the upper end of the limiting plate / main mechanism body and applies an upward pulling force to the limiting plate / main mechanism body.

[0012] Furthermore, the upper balancing member includes an electric hoist, and the upper end of the limiting plate / main mechanism body is connected to a U-shaped ring connected to a hook lock of the electric hoist.

[0013] Furthermore, a shaft protection box is connected to the support base, the target actuator includes an output shaft for outputting rotational motion, and a limiting hole for downward insertion of the output shaft is provided in the shaft protection box.

[0014] The present application also discloses a maintenance method for a maintenance device of a single-acting scotch yoke type pneumatic actuator, comprising the following steps: Step S10, including, after the target actuator is disassembled and the parts are replaced and repaired, it is placed on a support base; Step S30, including installing the spring assembly into the cylinder of the target actuator; Step S40, comprising: connecting one end of all axial drive screws to the target actuator, passing the other end through the rear cylinder cover, and tightening the first nut; Step S50, comprising: passing the outer end of the axial drive screw through the limit plate again, placing the second lifting mechanism between the limit plate and the rear cylinder cover, and tightening the second nut to fit the limit plate, the second lifting mechanism, and the rear cylinder cover; Step S60 includes driving the second lifting mechanism to lift, axially pushing the rear cylinder cover and the spring assembly to axially displace, and continuously tightening the first nut until the rear cylinder cover is installed in place.

[0015] In summary, the present invention has the following beneficial effects: 1. The axial pushing device composed of the limit plate, the second jack and the axial driving screw realizes the installation of the rear cylinder head under the force of the internal spring assembly, which saves time and effort. Compared with manually pushing the cylinder head, it reduces the reinstallation time by half and greatly reduces the manpower consumption; 2. The piston actuator is a powerful pneumatic actuator. The operating pressure of its cylinder can reach 0.8Mpa. The axial reverse thrust is very large during reinstallation. In the prior art, maintenance personnel have a greater safety risk in the axial position. With this maintenance device, they only need to operate the jack handle and tighten the second nut on both sides of the actuator, which greatly reduces the safety risk of maintenance personnel. 3. During installation, the existing technology has huge axial pressure, which makes it difficult to install and join the two sections of the cylinder body (between the main body and the outer cylinder of the cylinder body), and the unbalanced radial force can easily cause the cylinder body to deform. The present application makes it easy to disassemble and assemble the actuator through the first jack and the upper balance member, and will not cause the cylinder body to deform due to misalignment; 4. The application has a simple and practical structure and is easy to operate. Jacks and the like are simple daily maintenance tools. There is no need for a hydraulic press to be specially equipped like valve manufacturers for installation, which reduces daily maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of a maintenance device for a single-acting scotch fork type pneumatic actuator of the present invention; Figure 2 It is a structural schematic diagram of a supporting base portion in a maintenance device for a single-acting scotch fork type pneumatic actuator of the present invention; Figure 3 The invention discloses a cross-sectional schematic diagram of a rear cylinder cover portion of a maintenance device for a single-acting scotch fork type pneumatic actuator.

[0017] In the figure, 0, target actuator; 01, rear cylinder cover; 02, spring assembly; 03, main mechanism body; 04, outer cylinder body; 05, output shaft; 1, support base; 11, shaft protection box; 12, connecting bolts; 13, fixed angle steel; 14, fixed channel steel; 2, limit plate; 21, second jack; 22, second buffer block; 3, axial drive screw; 31, first nut; 32, second nut; 4, first jack; 5, electric hoist. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings, and this embodiment does not constitute a limitation of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0019] A maintenance device for a single-acting scotch yoke pneumatic actuator, such as Figure 1 and Figure 2 As shown, it includes a support base 1 and an axial pushing device, the target actuator 0 is placed on the support base 1, and the axial pushing device pushes the rear cylinder cover 01 in the target actuator 0 to overcome resistance for installation; The target actuator 0 includes a main body 03, an outer cylinder tube 04, and a rear cylinder cover 01. The main body 03 is provided with an output shaft 05, a shift fork, a piston and other structures. The outer cylinder tube 04 is detachably connected to one end of the main body 03. The rear cylinder cover 01 is provided on the outer end of the outer cylinder tube 04. The inner side of the rear cylinder cover 01 abuts against or is directly connected to the spring assembly 02, and forms a cylinder structure with the outer cylinder tube 04, the piston and the like. The target actuator 0 converts the linear motion of the cylinder piston into the rotational motion of the output shaft 05 through the shift fork. Among them, the outer cylinder body 04 and the main body 03 can be connected by structures such as flanges and bolts, and they can also be mutually nested structures. In this embodiment, the outer end cylinder of the main body 03 and the outer cylinder body 04 are joined by male and female buckles, and positioning blocks and other structures can also be provided to prevent rotation between the cylinders; its spring assembly 02 includes large and small springs, which are fixed on the inner side of the rear cylinder cover 01.

[0020] like Figure 2 As shown, a shaft protection box 11 is connected to the support base 1, and a limit hole is provided in the shaft protection box 11 for the output shaft 05 to be inserted downward; the support base 1 includes a well-shaped structure and a connecting bolt 12; the connecting bolt 12 connects the shaft protection box 11 with the well-shaped structure, and the well-shaped structure includes two parallel fixed angle steels 13 and two parallel fixed channel steels 14. The target actuator 0 is axially parallel to the fixed channel steel 14 and perpendicular to the fixed angle steel 13. The connecting bolt 12 connects the two ends of the shaft protection box 11 to the corresponding fixed channel steels 14 respectively; In this embodiment, two 1m long 14# fixed channel steels 14 are axially parallel welded on two fixed angle steels 13 as the support base 1, which is designed as a tic-tac-toe chassis to increase the ground contact area. A U-shaped ring is also welded at the center of the fixed angle steel 13. If the valve is installed at a high place, after the actuator is disassembled, the sling can pass through the U-shaped ring to facilitate the lifting by a car crane.

[0021] like Figure 1As shown, the axial pushing device includes a limit plate 2 (a section of channel steel, with a plurality of through holes in two sections), a second lifting mechanism and a plurality of axial driving screws 3. The limit plate 2 is located outside the rear cylinder cover 01. One end of the axial driving screw 3 is connected to the main mechanism body 03 (threaded or set in a screw shape, with the head end passing through and abutting against the side of the main mechanism body 03 away from the rear cylinder cover 01), and the other end passes through the rear cylinder cover 01 and the limit plate 2. A first nut 31 and two second nuts 32 are also threadedly connected to the axial driving screw 3. The first nut 31 abuts against the outside of the rear cylinder cover 01, and the second nut 32 abuts against the outside of the limit plate 2. The second lifting mechanism is located between the limit plate 2 and the rear cylinder cover 01, and pushes the rear cylinder cover 01 to move toward the target actuator 0, and continuously presses the spring assembly 02 inward; The threads of the axial drive screw 3, the first nut 31 and the two second nuts 32 are rectangular or trapezoidal in shape, so that the two positions can achieve better limit and stop effect to avoid thread slippage; Among them, the second lifting mechanism includes a second jack 21, a second buffer block 22 is arranged between the second jack 21 and the rear cylinder head 01, the top pad of the second jack 21 is against the limit plate 2, the second buffer block 22 is fixed at the base, the second buffer block 22 is against the rear bumper cover 01, and an axial thrust is generated by reciprocating the handle, and the thrust is transmitted from the second jack 21 to the second buffer block 22. The second buffer block 22 pushes the rear cylinder head 01 forward, and at the same time, the first nut 31 is continuously screwed on to complete the installation.

[0022] like Figure 1 As shown, a plurality of first lifting mechanisms are connected to the support base 1, the main mechanism body 03 is placed on the support base 1, and the cylinder outer cylinder 04 is placed on the first lifting mechanism, and is lifted and lowered by the first lifting mechanism to complete the axial leveling of the cylinder outer cylinder 04 and the main mechanism body 03 (including internal components), so that the cylinder outer cylinder 04 and the main mechanism body 03 are joined in place; Among them, the first lifting mechanism includes a first jack 4, and four or more first jacks 4 are symmetrically fixed on the upper side of the corresponding fixed channel steel 14, so that the two sides of the lower part of the outer tube 04 of the cylinder body respectively abut against the output end of the upper end of the first jack 4, providing an upward thrust to achieve lifting.

[0023] like Figure 1 As shown, in order to improve the stability of the device during operation, the maintenance device also includes an upper balance member, which is connected to the upper end of the limit plate 2 / main body 03 and applies an upward pulling force to the limit plate 2 / main body 03; In this embodiment, the upper balancing member includes an electric hoist 5. Since the end with the second jack 21 is heavier, the electric hoist 5 is connected to the upper end of the limiting plate 2, and the upper end of the limiting plate 2 is connected to a U-shaped ring connected to the hook lock of the electric hoist 5.

[0024] like Figure 3As shown, the main mechanism body 03 and the rear cylinder cover 01 are provided with a number of holes for connecting the original screw rods and connecting the rear cylinder cover 01 and the main mechanism body 03 to each other. During maintenance, all the holes are divided into at least two groups. The axial drive screw 3 is installed in one set of holes, passes through the rear cylinder cover 01 and is connected to the limit plate 2. The original screw is installed in another set of holes. After it is installed in place, the axial drive screw 3 is replaced with the original screw. In this embodiment, there are 12 holes A to L, which are divided into three groups. The first group is the A, B, C, and D holes on the left and right / upper and lower sides, where the corresponding axial drive screws 3 are installed, which penetrate the rear cylinder cover 01 and are connected to the corresponding ends of the limit plate 2. The second group is the E, F, K, and L holes on the upper and lower / left and right sides. Long lead screws are installed, passing through the rear cylinder cover 01 and connected to the limit nuts. As the second jack 21 moves, the first nut 31 and the limit nut are continuously tightened to limit the outer position of the rear cylinder cover 01. The third group is the G, H, I, and J holes at the four corners. After the rear cylinder cover 01 is installed in place, install the original lead screw, and finally replace the lead screws in the first and second groups with the original lead screws in turn (they can be disassembled and replaced in groups or one by one).

[0025] This embodiment also discloses a maintenance method for a maintenance device of a single-acting scotch yoke type pneumatic actuator, comprising the following steps: Step S10, including disassembling the target actuator 0 and replacing the sealing ring and other parts after the inspection is completed, and then placing it on the support base 1; Specifically, the shaft protection box 11 is connected to the support base 1 (a tic-tac-toe structure) by connecting bolts 12, and after being stably placed on the ground, the output shaft 05 in the main mechanism body 03 is inserted downward into the shaft protection box 11 until the main mechanism body 03 abuts against the upper side of the shaft protection box 11, and a plurality of first jacks 4 (depending on the length of the cylinder) are placed or fixed on the support base 1; Step S20, including placing the cylinder outer tube 04 between the first jacks 4 on both sides, and lifting and lowering the first jacks 4 to achieve axial docking and leveling with the main mechanism body 03, so that the two are docked in place to avoid misalignment (the cylinder outer tube 04 and the main mechanism body 03 can be connected by bolts in this step, or can be mutually nested and connected under the push of the second jack 21 in a subsequent step); Step S30, including installing the spring assembly 02 into the cylinder of the target actuator 0; Step S40, including: connecting one end of all axial drive screws 3 to the main mechanism body 03 (A, B, C, D holes), passing the other end through the rear cylinder cover 01, and tightening the first nut 31; connecting one end of the long screw to the main mechanism body 03 (E, F, K, L holes), passing the other end through the rear cylinder cover 01, and tightening the limit nut; after manually pushing the rear cylinder cover 01 to keep the spring assembly 02 in a certain deformation, the first nut 31 can be screwed on; Step S50, including passing the outer end of the axial driving screw 3 through the limit plate 2 (the upper end of the limit plate 2 is connected to the hook lock of the lower end of the electric hoist 5), and placing the second jacking mechanism and the buffer block between the limit plate 2 and the rear cylinder cover 01, the buffer block fits the rear cylinder cover 01, the second jack 21 fits the buffer block, the limit plate 2 abuts the second jack 21, and after ensuring that the limit plate 2, the second jack 21, and the buffer block are axially balanced (the three can also be directly fixed together), then tighten the second nut 32, so that the limit plate 2, the second jacking mechanism, the buffer block, and the rear cylinder cover 01 are tightly fitted, and the spring assembly 02 is deformed to a certain extent; Step S60, including reciprocatingly pulling the handle of the second jack 21 to drive the second jack 21 to lift, push the rear cylinder head 01 and the spring assembly 02 to axially displace (the outer cylinder tube 04 of the cylinder body can also be nested with the main body 03 by lifting the second jack 21), and continuously tighten the first nut 31 and the limit nut until the rear cylinder head 01 and the outer cylinder tube 04 of the cylinder body are installed in place, and the first nut 31 is also screwed in place (if the second jack 21 does not have enough travel during the process, the second jack 21 can also be driven to reset, and the second nut 32 can be tightened at the same time, so that the limit plate 2 continues to move forward); Step S70 includes connecting one end of the original lead screw to the main mechanism body 03, and passing the other end through the rear cylinder cover 01 (E, F, K, L holes), and tightening the original nut thereon so that it is pressed against the outer side of the rear cylinder cover 01, and then replacing the axial drive lead screw 3 and the long lead screw one by one or in groups with the corresponding original lead screws and original nuts, and the installation of the actuator is completed.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. A maintenance device for a single-acting scotch fork pneumatic actuator, characterized in that: It includes a support base and an axial pushing device, on which a target actuator is placed; the target actuator includes a rear cylinder cover at the end and an internal spring assembly, the axial pushing device includes a limit plate, a second lifting mechanism and a plurality of axial drive screws, the limit plate is located on the outside of the rear cylinder cover, one end of the axial drive screw is connected to the target actuator, and the other end passes through the rear cylinder cover and the limit plate, the axial drive screw is also threadedly connected with a first nut and a second nut, the first nut abuts against the outside of the rear cylinder cover, and the second nut abuts against the outside of the limit plate, the second lifting mechanism is located between the limit plate and the rear cylinder cover, pushes the rear cylinder cover to move toward the target actuator, and continuously presses the spring assembly inward.

2. The maintenance device for a single-acting scotch fork pneumatic actuator according to claim 1, characterized in that: The second lifting mechanism includes a second jack.

3. A maintenance device for a single-acting scotch fork pneumatic actuator according to claim 1 or 2, characterized in that: A second buffer block is provided between the second lifting mechanism and the rear cylinder cover.

4. The maintenance device for a single-acting scotch fork pneumatic actuator according to claim 1, characterized in that: The support base is connected to a plurality of first lifting mechanisms, and the target actuator includes a main mechanism body and a cylinder body. The outer cylinder tube of the cylinder body is detachably connected to one end of the main body, the rear cylinder cover is arranged on the outer end of the outer cylinder tube of the cylinder body, the main body is placed on the support base, the outer cylinder tube of the cylinder body is placed on the first lifting mechanism, and is lifted and lowered by the first lifting mechanism to engage with the main body in place.

5. The maintenance device for a single-acting scotch fork pneumatic actuator according to claim 4, characterized in that: The first lifting mechanism includes a first jack.

6. The maintenance device for a single-acting scotch-fork pneumatic actuator according to claim 1, characterized in that: The target actuator and the rear cylinder cover are provided with a plurality of holes for connecting the original screw rods and connecting the rear cylinder cover and the target actuator to each other. During maintenance, all the holes are divided into at least two groups. An axial drive screw is installed in one set of holes, which passes through the rear cylinder cover and is connected to the limit plate. The original screw is installed in another set of holes. After it is in place, the axial drive screw is replaced with the original screw.

7. The maintenance device for a single-acting scotch fork pneumatic actuator according to claim 4, characterized in that: It also includes an upper balancing member, which is connected to the upper end of the limiting plate / main mechanism body and applies an upward pulling force to the limiting plate / main mechanism body.

8. The maintenance device for a single-acting scotch-fork pneumatic actuator according to claim 7, characterized in that: The upper balancing member comprises an electric hoist, and the upper end of the limiting plate / main mechanism body is connected to a U-shaped ring connected to the hook lock of the electric hoist.

9. The maintenance device for a single-acting scotch fork pneumatic actuator according to claim 1, characterized in that: The support base is connected with a shaft protection box, the target actuator comprises an output shaft for outputting rotational motion, and a limiting hole for downward insertion of the output shaft is provided in the shaft protection box.

10. A maintenance method for a maintenance device of a single-acting scotch yoke pneumatic actuator according to claim 1, characterized in that: The following steps are included: Step S10, including, after the target actuator is disassembled and the parts are replaced and repaired, it is placed on a support base; Step S30 includes: Install the spring assembly into the cylinder of the target actuator; Step S40, comprising: connecting one end of all axial drive screws to the target actuator, passing the other end through the rear cylinder cover, and tightening the first nut; Step S50, comprising: passing the outer end of the axial drive screw through the limit plate again, placing the second lifting mechanism between the limit plate and the rear cylinder cover, and tightening the second nut to fit the limit plate, the second lifting mechanism, and the rear cylinder cover; Step S60 includes driving the second lifting mechanism to lift, axially pushing the rear cylinder cover and the spring assembly to axially displace, and continuously tightening the first nut until the rear cylinder cover is installed in place.

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