A valve pneumatic actuator

Abstract

The present invention discloses a valve pneumatic actuator, which relates to the technical field of valve actuators, including a cylinder body, a left end cover, a right end cover, a left piston and a right piston placed in the cylinder body, and a gear shaft meshed with the left piston and the right piston, and also includes a limit block fixed to the outer wall of the gear shaft, a limit assembly and an adjustment assembly, the limit assembly is arranged in the cylinder body, and is used to limit the limit block; the adjustment assembly is arranged on the cylinder body and is located below the limit assembly, and the adjustment assembly is used to adjust the speed of the left piston and the right piston moving in the cylinder body through the limit assembly. The present invention continuously compresses the first elastic member, so that the moving distance of the first slider in the first guide groove continuously changes, so that the cross section of the first air inlet hole continuously decreases with the compression of the third elastic member, and the air intake flow of the first air inlet hole is controlled, so as to prevent the left piston and the right piston from moving too fast in the cylinder body, resulting in the problem that the left piston and the right piston in the cylinder body are separated from the gear shaft.

Description

Technical Field

[0001] The present invention relates to the technical field of valve actuators, and in particular to a valve pneumatic actuator. Background Art

[0002] Pneumatic actuator is a commonly used actuator, which is driven by gas pressure and can perform various operations, such as opening and closing, rotation and adjustment. Pneumatic actuator has the characteristics of light weight, small size, stable operation and low noise. Pneumatic actuator is the execution part, which is used to control the opening and closing of valves, etc., and is suitable for many valves such as ball valves, butterfly valves and plug valves. Pneumatic actuators are divided into single-acting pneumatic actuators and double-acting pneumatic actuators.

[0003] For example, the Chinese patent application number 201320824585.X discloses a pneumatic valve actuator, including a cylinder body, a left end cover, a right end cover, a left piston and a right piston placed in the cylinder body, and a gear shaft, the gear shaft is meshed with the racks on the left piston and the right piston, respectively, and the cylinder body is provided with a first channel and a second channel, the internal port of the first channel is located between the left piston and the right piston, and the second channel is connected with the left end cover and the right end cover, respectively, and is characterized in that a sealing guide ring is provided between the left piston and the cylinder body, and between the right piston and the cylinder body, respectively, and the sealing guide ring includes a sealing ring and a reinforced sealing body, the reinforced sealing body is arranged on the periphery of the sealing ring, and the reinforced sealing body is fixedly connected to the sealing ring, and the height of the reinforced sealing body is greater than the height of the sealing ring. The overall sealing effect is good, it is not easy to wear during use, and it can be applied to dynamic occasions where the piston frequently reciprocates. However, the invention still has the problem that when the pressure of the gas source entering the cylinder body remains unchanged, the left piston and the right piston move rapidly in the cylinder body, which may cause the left piston and the right piston in the cylinder body to separate from the gear shaft, causing the cylinder body to rupture, directly damaging the cylinder body, and making the valve unable to work normally; there is also the problem that when water flows through the valve, if the valve is opened or closed quickly, a water hammer effect will occur, which may damage the valve and other pipeline facilities.

[0004] Therefore, the present invention proposes a valve pneumatic actuator to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a valve pneumatic actuator, which solves the technical problems raised in the above-mentioned background technology through a limit assembly and an adjustment assembly.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a valve pneumatic actuator, comprising a cylinder body, a left end cover, a right end cover, a left piston and a right piston disposed in the cylinder body, and a gear shaft meshing with the left piston and the right piston, and also comprising: a limit block fixed on the outer wall of the gear shaft; a limit assembly, the limit assembly is arranged in the cylinder body and is used to limit the limit block; an adjustment assembly, the adjustment assembly is arranged on the cylinder body and is located below the limit assembly, and the adjustment assembly can adjust the speed at which the left piston and the right piston move in the cylinder body through the limit assembly.

[0007] Preferably, the limiting assembly includes a first air cylinder and a second air cylinder fixed on the side wall of the cylinder body, a first limiting cavity and a first air collecting cavity are provided in the first air cylinder, a first piston is slidably connected in the first limiting cavity, one end of the first piston is fixedly connected to a first piston rod, one end of the first piston rod extending out of the first air cylinder is movably connected to the side wall of the limiting block, a first elastic member is provided in the first air collecting cavity, a first fixing rod is provided in the first air cylinder, one end of the first elastic member is connected to an end of the first piston away from the first piston rod, the other end of the first elastic member is connected to an end of the first fixing rod located in the first air cylinder, and a first connecting hole connected to the first air collecting cavity is provided on the outer wall of the first air cylinder.

[0008] Preferably, a second limiting chamber and a second air collecting chamber are provided in the second air cylinder, a second piston is slidably connected in the second limiting chamber, one end of the second piston is fixedly connected to a second piston rod, one end of the second piston rod extending out of the second air cylinder is movably connected to the side wall of the limiting block, a second elastic member is provided in the second air collecting chamber, a second fixing rod is provided in the second air cylinder, one end of the second elastic member is connected to an end of the second piston away from the second piston rod, the other end of the second elastic member is connected to an end of the second fixing rod located in the second air cylinder, and a second connecting hole connected to the second air collecting chamber is provided on the outer wall of the second air cylinder.

[0009] Preferably, the adjustment assembly includes a guide member fixed on the side of the cylinder body, the cylinder body is provided with a first channel and a second channel, the guide member is provided with a first air inlet hole connected to the first channel, the guide member is also provided with a second air inlet hole connected to the second channel, the first channel is connected to the chamber between the left piston and the right piston in the cylinder body, and the second channel is respectively connected to the chamber between the left piston and the left end cover and the chamber between the right piston and the right end cover in the cylinder body.

[0010] Preferably, a first guide groove and a second guide groove are respectively provided on both sides of the guide member, the first guide groove is connected to the first air inlet hole, the second guide groove is connected to the second air inlet hole, a first slider is slidably connected in the first guide groove, and a second slider is slidably connected in the second guide groove.

[0011] Preferably, a third air cylinder and a fourth air cylinder are fixedly connected on both sides of the guide member, a third piston is slidably connected in the third air cylinder, one end of the third piston is fixedly connected to a third piston rod, one end of the third piston rod extending out of the third air cylinder is fixedly connected to the first slider, a third elastic member is sleeved on the outer wall of the third piston rod, one end of the third elastic member is connected to the inner wall of the third air cylinder, the other end of the third elastic member is connected to an end of the third piston close to the third piston rod, and a third connecting hole is provided at an end of the third air cylinder away from the third piston rod.

[0012] Preferably, a fourth piston is slidably connected inside the fourth air cylinder, one end of the fourth piston is fixedly connected to a fourth piston rod, one end of the fourth piston rod extending out of the fourth air cylinder is fixedly connected to the second slider, a fourth elastic member is sleeved on the outer wall of the fourth piston rod, one end of the fourth elastic member is connected to the inner wall of the fourth air cylinder, the other end of the fourth elastic member is connected to an end of the fourth piston close to the fourth piston rod, and a fourth connecting hole is provided at an end of the fourth air cylinder away from the fourth piston rod.

[0013] Preferably, the third communicating hole is connected to the first communicating hole through a pipeline.

[0014] Preferably, the fourth connecting hole is connected to the second connecting hole through a pipeline.

[0015] Preferably, a valve is fixedly connected to the bottom of the cylinder body, and a valve stem of the valve is connected to a slot provided on the gear shaft.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention uses the first elastic member to buffer the first piston as the first piston is continuously squeezed, so that when the limit block rotates counterclockwise and hits the first piston rod, the first piston rod can be buffered, avoiding the first piston rod being damaged by the impact when the limit block rotates counterclockwise, resulting in the problem that the valve cannot be opened properly; the second elastic member uses the second elastic member to buffer the second piston as the second piston is continuously squeezed, so that when the limit block rotates clockwise and hits the second piston rod, the second piston rod can be buffered, avoiding the second piston rod being damaged by the impact when the limit block rotates clockwise, resulting in the problem that the valve cannot be closed properly.

[0018] 2. The present invention continuously compresses the first elastic member so that the moving distance of the first slider in the first guide groove continuously changes, and the cross-section of the first air inlet hole continuously decreases with the compression of the third elastic member, thereby controlling the air intake flow of the first air inlet hole and preventing the left piston and the right piston from moving too fast in the cylinder body, causing the left piston and the right piston in the cylinder body to separate from the gear shaft, resulting in cylinder rupture, direct damage to the cylinder body, and the valve being unable to work normally. The present invention continuously compresses the second elastic member so that the moving distance of the second slider in the second guide groove continuously changes, and the cross-section of the second air inlet hole continuously decreases with the compression of the fourth elastic member, thereby controlling the air intake amount of the second air inlet hole and preventing the valve from closing quickly when water flows in the valve, causing water hammer effect and damaging pipeline facilities.

[0019] 3. The present invention expands and contracts the first piston through the first elastic member, expands and contracts the third piston through the third elastic member, and the compressed gas in the third gas cylinder further supports the first piston, so that when the first piston rod and the limit block are worn, the wear between the first piston rod and the limit block can be compensated in real time, preventing the gear shaft from turning too many times and causing the valve to open and close improperly, resulting in internal leakage of the valve; the second piston is expanded and squeezed by the second elastic member, and the fourth piston is expanded and squeezed by the fourth elastic member, and the compressed gas in the fourth gas cylinder further supports the second piston, so that when the second piston rod and the limit block are worn, the wear between the second piston rod and the limit block can be compensated in real time, preventing the gear shaft from turning too many times and causing the valve to open and close improperly, resulting in internal leakage of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the cylinder structure of the present invention.

[0022] Figure 3 It is a schematic diagram of the local structure of the gear shaft of the present invention.

[0023] Figure 4 It is a structural schematic diagram of the gear shaft of the present invention rotating counterclockwise to the maximum limit position.

[0024] Figure 5 This is a structural sectional view of the gear shaft of the present invention when it rotates clockwise to the maximum limit position.

[0025] Figure 6 It is an exploded view of the cylinder body of the present invention.

[0026] Figure 7 It is an exploded view of the guide member of the present invention.

[0027] Figure 8 It is a schematic diagram of the full cross-section structure of the guide member of the present invention at the first guide groove.

[0028] Fig. 9 It is a schematic diagram of the full cross-section structure of the third air cylinder in the compressed state of the third elastic member of the present invention.

[0029] Fig.10 It is a schematic diagram of the full cross-section structure of the fourth air cylinder in the expanded state of the fourth elastic member of the present invention.

[0030] Fig.11 It is a full cross-sectional view of the first air cylinder at the first communicating hole when the first elastic member of the present invention is in a compressed state.

[0031] Fig.12 It is a full cross-sectional view of the second air cylinder at the second connecting hole when the second elastic member of the present invention is in a relaxed state.

[0032] The accompanying drawings are marked as follows: 1, cylinder body; 2, left end cover; 3, right end cover; 4, left piston; 5, right piston; 6, gear shaft; 61, limit block; 7, limit assembly; 71, first air cylinder; 711, first piston; 712, first piston rod; 713, first elastic member; 714, first fixing rod; 715, first communicating hole; 72, second air cylinder; 721, second piston; 722, second piston rod; 723, second elastic member; 724, second fixing rod; 725, second communicating hole; 8 , adjusting component; 81, guide member; 811, first air inlet hole; 812, second air inlet hole; 813, first guide groove; 814, second guide groove; 815, first slider; 816, second slider; 82, third air cylinder; 821, third piston; 822, third piston rod; 823, third elastic member; 824, third connecting hole; 83, fourth air cylinder; 831, fourth piston; 832, fourth piston rod; 833, fourth elastic member; 834, fourth connecting hole; 9, valve. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0034] It is found in actual use that with the existing valve pneumatic actuator, as the valve opens and closes quickly and the number of times used increases, the upper limit cam on the gear shaft in the cylinder body impacts with the limit screw, causing a dent in the side wall of the limit cam, resulting in the pneumatic valve not being able to open or close properly. This embodiment is specially invented to solve the above problem.

[0035] See also Figure 1 , Figure 4 and Figure 5 A valve pneumatic actuator according to an embodiment of the present invention comprises a cylinder body 1, a left end cover 2, a right end cover 3, a left piston 4 and a right piston 5 placed in the cylinder body 1, and a gear shaft 6 meshing with the left piston 4 and the right piston 5. A first channel and a second channel are provided on the cylinder body 1. The first channel is communicated with the chamber between the left piston 4 and the right piston 5 in the cylinder body 1, and the second channel is communicated with the chamber between the left piston 4 and the left end cover 2 and the chamber between the right piston 5 and the right end cover 3 in the cylinder body respectively; wherein the cylinder body 1 is the prior art, the left piston 4 and the right piston 5 are the prior art and are provided with spur gears meshing with the gear shaft 6, which will not be described in detail here; it also comprises a limit block 61 fixed to the outer wall of the gear shaft 6, a limit assembly 7 and an adjustment assembly 8, and a valve 9 is fixedly connected to the bottom of the cylinder body 1; in combination with Figure 3 and Figure 6 The valve stem of the valve 9 is connected to the slot provided on the gear shaft 6 .

[0036] See also Figure 1 and Figure 2 The limiting assembly 7 is arranged in the cylinder body 1 and is used to limit the limiting block 61. The limiting assembly 7 includes a first gas cylinder 71 and a second gas cylinder 72 fixed on the side wall of the cylinder body 1. Fig.11 A first limiting chamber and a first air collecting chamber are provided in the first air cylinder 71, a first piston 711 is slidably connected in the first limiting chamber, one end of the first piston 711 is fixedly connected to a first piston rod 712, one end of the first piston rod 712 extending out of the first air cylinder 71 is movably connected to the side wall of the limiting block 61, a first elastic member 713 is provided in the first air collecting chamber, wherein the first elastic member 713 is a spring, a first fixing rod 714 is provided in the first air cylinder 71, one end of the first elastic member 713 is connected to an end of the first piston 711 away from the first piston rod 712, the other end of the first elastic member 713 is connected to an end of the first fixing rod 714 located in the first air cylinder 71, and a first connecting hole 715 connected to the first air collecting chamber is provided on the outer wall of the first air cylinder 71.

[0037] See also Fig.12 A second limiting chamber and a second air collecting chamber are provided in the second air cylinder 72, a second piston 721 is slidably connected in the second limiting chamber, one end of the second piston 721 is fixedly connected to a second piston rod 722, one end of the second piston rod 722 extending out of the second air cylinder 72 is movably connected to the side wall of the limiting block 61, a second elastic member 723 is provided in the second air collecting chamber, wherein the second elastic member 723 is a spring, a second fixing rod 724 is provided in the second air cylinder 72, one end of the second elastic member 723 is connected to an end of the second piston 721 away from the second piston rod 722, the other end of the second elastic member 723 is connected to an end of the second fixing rod 724 located in the second air cylinder 72, and a second connecting hole 725 connected to the second air collecting chamber is opened on the outer wall of the second air cylinder 72.

[0038] When in use, when the gas source enters the chamber formed by the left piston 4 and the right piston 5 through the first channel, the compressed gas synchronously pushes the left piston 4 to move toward the left end cover 2 in the cylinder body 1, and the right piston 5 moves toward the right end cover 3 in the cylinder body 1, and the gas at both ends of the cylinder body 1 is discharged from the second channel; synchronously, the gear shaft 6 rotates counterclockwise with the movement of the left piston 4 and the right piston 5, and the gear shaft 6 rotates counterclockwise while driving the limit block 61 to rotate counterclockwise, and the limit block 61 rotates counterclockwise while gradually squeezing the first piston rod 712, and the first piston rod 712 moves in the first air cylinder 71 while driving the first piston 711 to move, and the first piston 711 moves while The first elastic member 713 is squeezed. When the end face of the first piston 711 contacts the inner wall of the first limiting chamber, the end face of the first piston rod 712 is in surface contact with the side face of the limiting block 61. At this time, the valve 9 is completely opened by the counterclockwise rotation of the gear shaft 6. At the same time, the first elastic member 713 is compressed to the maximum limit position. The first elastic member 713 is continuously squeezed by the first piston 711, so that the first elastic member 713 buffers the first piston 711, so that when the limiting block 61 rotates counterclockwise to hit the first piston rod 712, the first piston rod 712 can be buffered, thereby avoiding the first piston rod 712 being damaged by the impact when the limiting block 61 rotates counterclockwise, resulting in the problem that the valve 9 cannot be opened.

[0039] When the gas source enters the cylinder body 1 through the second channel and enters the chambers respectively located between the left piston 4 and the left end cover 2 and between the right piston 5 and the right end cover 3, the compressed gas pushes the left piston 4 and the right piston 5 closer to each other in the cylinder body 1, and the gas located between the left piston 4 and the right piston 5 in the cylinder body 1 is discharged through the first channel; synchronously, the gear shaft 6 rotates clockwise with the movement of the left piston 4 and the right piston 5, and the gear shaft 6 rotates clockwise while driving the limit block 61 to rotate clockwise, and the limit block 61 rotates clockwise while gradually squeezing the second piston rod 722, and the second piston rod 722 moves in the second gas cylinder 72 while driving the second piston 721 to move, and the second piston 721 moves while squeezing The second elastic member 723, when the end face of the second piston 721 contacts the inner wall of the second limiting chamber, the end face of the second piston rod 722 is in surface contact with the side face of the limiting block 61. At this time, the valve 9 is completely closed by the clockwise rotation of the gear shaft 6, and the second elastic member 723 is compressed to the maximum limit position. The second elastic member 723 is continuously squeezed by the second piston 721, so that the second elastic member 723 buffers the second piston 721, so that when the limiting block 61 rotates clockwise to hit the second piston rod 722, the second piston rod 722 can be buffered, thereby avoiding the second piston rod 722 being damaged by the impact when the limiting block 61 rotates clockwise, resulting in the problem that the valve 9 cannot be closed.

[0040] In actual use, it is found that although the first elastic member 713 and the second elastic member 723 can buffer the impact of the limit block 61 on the first piston rod 712 and the second piston rod 722, when the pressure of the gas source entering the cylinder body 1 remains unchanged, the left piston 4 and the right piston 5 move rapidly in the cylinder body 1, which may cause the left piston 4 and the right piston 5 in the cylinder body 1 to separate from the gear shaft 6, causing the cylinder body 1 to rupture, directly damaging the cylinder body 1, and making the valve 9 unable to work normally; and when the valve 9 is opened and closed widely due to the rapid rotation of the gear shaft 6, if water flows in the valve 9, a water hammer effect will occur, which may damage the valve 9 and other pipeline facilities. Further improvements are made on the basis of the above-mentioned embodiments.

[0041] See also Figure 1 and Figure 2 The adjusting assembly 8 is arranged on the cylinder body 1 and is located below the limiting assembly 7. The adjusting assembly 8 can adjust the speed of the left piston 4 and the right piston 5 moving in the cylinder body 1 through the limiting assembly 7. The adjusting assembly 8 includes a guide member 81 fixed on the side of the cylinder body 1; Figure 2 , Figure 4 , Figure 5 and Figure 7 The guide member 81 is provided with a first air inlet hole 811 connected to the first channel, and the guide member 81 is also provided with a second air inlet hole 812 connected to the second channel. A first guide groove 813 and a second guide groove 814 are respectively provided on both sides of the guide member 81. The first guide groove 813 is connected to the first air inlet hole 811, and the second guide groove 814 is connected to the second air inlet hole 812. A first slider 815 is slidably connected in the first guide groove 813, and a second slider 816 is slidably connected in the second guide groove 814.

[0042] See also Figure 7 and Figure 8 , the third gas cylinder 82 and the fourth gas cylinder 83 are fixedly connected to both sides of the guide member 81; Fig. 9 A third piston 821 is slidably connected in the third gas cylinder 82, one end of the third piston 821 is fixedly connected to a third piston rod 822, one end of the third piston rod 822 extending out of the third gas cylinder 82 is fixedly connected to the first slider 815, and a third elastic member 823 is sleeved on the outer wall of the third piston rod 822, wherein the third elastic member 823 is a spring, one end of the third elastic member 823 is connected to the inner wall of the third gas cylinder 82, and the other end of the third elastic member 823 is connected to an end of the third piston 821 close to the third piston rod 822, and a third connecting hole 824 is provided at one end of the third gas cylinder 82 away from the third piston rod 822, Fig.10A fourth piston 831 is slidably connected in the fourth air cylinder 83, one end of the fourth piston 831 is fixedly connected to a fourth piston rod 832, one end of the fourth piston rod 832 extending out of the fourth air cylinder 83 is fixedly connected to the second slider 816, and the outer wall of the fourth piston rod 832 is sleeved with a fourth elastic member 833, wherein the fourth elastic member 833 is a spring, one end of the fourth elastic member 833 is connected to the inner wall of the fourth air cylinder 83, and the other end of the fourth elastic member 833 is connected to an end of the fourth piston 831 close to the fourth piston rod 832, and a fourth connecting hole 834 is provided at an end of the fourth air cylinder 83 away from the fourth piston rod 832, the third connecting hole 824 is connected to the first connecting hole 715 through a pipeline, and the fourth connecting hole 834 is connected to the second connecting hole 725 through a pipeline.

[0043] On the basis of the above embodiment, when the gas source enters the first channel through the first air inlet hole 811, and the compressed gas enters the interior of the cylinder body 1 and the chamber formed between the left piston 4 and the right piston 5 through the first channel, the compressed gas synchronously pushes the left piston 4 to move toward the left end cover 2 in the cylinder body 1, and the right piston 5 to move toward the right end cover 3 in the cylinder body 1, and the gas at both ends of the cylinder body 1 is discharged from the second channel into the second air inlet hole 812 and discharged through the second air inlet hole 812; synchronously, the gear shaft 6 rotates counterclockwise with the movement of the left piston 4 and the right piston 5, and the gear shaft 6 rotates counterclockwise while bringing The movable limit block 61 rotates counterclockwise, and the limit block 61 gradually squeezes the first piston rod 712 while rotating counterclockwise. The first piston rod 712 moves in the first gas cylinder 71 and drives the first piston 711 to move. The first piston 711 squeezes the first elastic member 713 while moving. Synchronously, the gas in the first limit cavity is compressed. When the end face of the first piston 711 contacts the inner wall of the first limit cavity, the first elastic member 713 is compressed to the maximum limit position. At this time, the gas in the first gas cylinder 71 is compressed to the maximum limit, and the compressed gas in the first gas cylinder 71 passes through the first connecting hole. 715 and the pipeline enter into the third connecting hole 824, the compressed gas enters into the third gas cylinder 82 through the third connecting hole 824, the compressed gas pushes the third piston 821 to move, the third piston 821 moves while driving the third piston rod 822 to move, the third piston rod 822 moves while driving the first slider 815 to move in the first guide groove 813; synchronously, the third piston 821 moves while continuously squeezing the third elastic member 823, when the third elastic member 823 is compressed to the maximum limit, at this time, the first slider 815 is closest to the inner wall of the first air inlet hole 811, through the first slider 815 makes the cross-section of the first air inlet hole 811 at the first guide groove 813 the smallest, so that the flow rate of compressed gas entering the cylinder body 1 through the first air inlet hole 811 and the first channel is minimized. At this time, the compressed gas between the left piston 4 and the right piston 5 squeezes the left piston 4 and the right piston 5 to move at the slowest speed, thereby preventing the left piston 4 and the right piston 5 from moving too fast in the cylinder body 1, causing the valve 9 to open quickly due to the rapid rotation of the gear shaft 6, causing the left piston 4 and the right piston 5 in the cylinder body 1 to separate from the gear shaft 6, causing the cylinder body 1 to rupture, directly damaging the cylinder body 1, and making the valve 9 unable to work normally.

[0044] To sum up, through the continuous compression of the first elastic member 713, the moving distance of the first slider 815 in the first guide groove 813 is continuously changed, so that the cross-section of the first air inlet hole 811 is continuously reduced with the compression of the third elastic member 823, thereby controlling the air intake flow of the first air inlet hole 811, preventing the left piston 4 and the right piston 5 from moving too fast in the cylinder body 1, causing the left piston 4 and the right piston 5 in the cylinder body 1 to be separated from the gear shaft 6, causing the cylinder body 1 to rupture, directly damaging the cylinder body 1, and making the valve 9 unable to work normally; preventing the water hammer effect caused by the rapid opening of the valve 9 when water flows in it.

[0045] When the gas source enters the second channel through the second air inlet hole 812, and the compressed gas enters the chambers located between the left piston 4 and the left end cover 2 and between the right piston 5 and the right end cover 3 in the cylinder body 1 through the second channel, the compressed gas pushes the left piston 4 and the right piston 5 to approach each other in the cylinder body 1, and the gas located between the left piston 4 and the right piston 5 in the cylinder body 1 is discharged from the first air inlet hole 811 through the first channel; synchronously, the gear shaft 6 rotates clockwise with the movement of the left piston 4 and the right piston 5, and the gear shaft 6 rotates clockwise while driving the limit block 61 The second piston rod 722 is gradually squeezed while the limiting block 61 rotates clockwise. The second piston rod 722 moves in the second gas cylinder 72 and drives the second piston 721 to move. The second piston 721 moves and squeezes the second elastic member 723. Synchronously, the gas in the second limiting chamber is compressed. When the end face of the second piston 721 contacts the inner wall of the second limiting chamber, the second elastic member 723 is compressed to the maximum limit position. At this time, the gas in the second gas cylinder 72 is compressed to the maximum limit. The compressed gas enters the fourth cylinder 83 through the second connecting hole 725 and the pipeline, and the compressed gas enters the fourth cylinder 83 through the fourth connecting hole 834. The compressed gas pushes the fourth piston 831 to move. The fourth piston 831 moves while driving the fourth piston rod 832 to move. The fourth piston rod 832 moves while driving the second slider 816 to move in the second guide groove 814. Synchronously, the fourth piston 831 moves while continuously squeezing the fourth elastic member 833. When the fourth elastic member 833 is compressed to the maximum limit, the second slider 816 It is closest to the inner wall of the second air inlet hole 812, and the second slider 816 is used to minimize the cross-section of the second air inlet hole 812 at the second guide groove 814, so that the flow of compressed gas entering the cylinder body 1 through the second air inlet hole 812 and the second channel is minimized. At this time, the compressed gas squeezes the left piston 4 and the right piston 5 to move at the slowest speed, thereby preventing the left piston 4 and the right piston 5 from moving too fast in the cylinder body 1, causing the valve 9 to close quickly due to the rapid rotation of the gear shaft 6, and preventing the water hammer effect caused by the rapid closure when water flows through the pipe connected to the valve 9.

[0046] To sum up, through the continuous compression of the second elastic member 723, the moving distance of the second slider 816 in the second guide groove 814 is continuously changed, so that the cross-section of the second air inlet hole 812 is continuously reduced with the compression of the fourth elastic member 833, thereby controlling the air intake amount of the second air inlet hole 812 and preventing the valve 9 from closing quickly when water flows in it and causing water hammer effect to damage the pipeline facilities.

[0047] On the basis of the above embodiment, as the limit block 61 rotates, the first piston rod 712 and the second piston rod 722 are worn, resulting in the failure of the first piston rod 712 and the second piston rod 722 to limit the limit block 61, and the gear shaft 6 rotates multiple times, causing the valve 9 to not open and close properly, resulting in the problem of internal leakage of the valve 9. If the adjustment range is too large or adjusted at will, the pneumatic actuator will be stuck and the valve 9 will fail to open and close. Frequent adjustment causes inconvenience in use, and this embodiment is specially invented for this purpose.

[0048] On the basis of the above embodiment, when the first piston rod 712 contacts the limit block 61, the first elastic member 713 is compressed to the maximum limit position by the first piston 711. As the first piston rod 712 wears, the first elastic member 713 expands and squeezes the first piston 711, so that the first piston rod 712 is always in contact with the side of the limit block 61. When the first elastic member 713 is compressed to the maximum limit position by the first piston 711, the compressed gas in the first connecting hole 715 further squeezes the first piston 711, thereby fine-tuning the first piston rod 712. Synchronously, the air in the third air cylinder 82 is compressed when the third elastic member 823 expands and contracts. When the first piston 711 is stretched, the third piston 821 further squeezes the compressed gas, so that the compressed gas enters the first connecting hole 715 through the third connecting hole 824 and the pipeline, and further supports the first piston 711. The first piston 711 is squeezed by the expansion and contraction of the first elastic member 713, and the third piston 821 is squeezed by the expansion and contraction of the third elastic member 823. The compressed gas in the third gas cylinder 82 further supports the first piston 711, so that when the first piston rod 712 and the limit block 61 are worn, the wear between the first piston rod 712 and the limit block 61 can be compensated in real time, thereby preventing the gear shaft 6 from rotating too much and causing the valve 9 to fail to open and close properly, resulting in internal leakage of the valve 9.

[0049] When the second piston rod 722 contacts the limit block 61, the second elastic member 723 is compressed to the maximum limit position by the second piston 721. As the second piston rod 722 wears, the second elastic member 723 expands to squeeze the second piston 721, so that the second piston rod 722 is always in contact with the side of the limit block 61. When the second elastic member 723 is compressed to the maximum limit position by the second piston 721, the compressed gas in the second connecting hole 725 further squeezes the second piston 721, thereby fine-tuning the second piston rod 722. Synchronously, when the fourth elastic member 833 expands, the air in the fourth air cylinder 83 is compressed by the fourth elastic member 833. The fourth piston 831 is further squeezed, so that the compressed gas enters the second connecting hole 725 through the fourth connecting hole 834 and the pipeline, and further supports the second piston 721. The second piston 721 is squeezed by the expansion and contraction of the second elastic member 723, and the fourth piston 831 is squeezed by the expansion and contraction of the fourth elastic member 833. The compressed gas in the fourth gas cylinder 83 further supports the second piston 721, so that when the second piston rod 722 and the limit block 61 are worn, the wear between the second piston rod 722 and the limit block 61 can be compensated in real time, thereby preventing the gear shaft 6 from turning too much and causing the valve 9 to fail to open and close properly, resulting in internal leakage of the valve 9.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A valve pneumatic actuator, comprising a cylinder body, a left end cover, a right end cover, a left piston and a right piston disposed in the cylinder body, and a gear shaft meshing with the left piston and the right piston, characterized in that: Also includes: A limit block fixed on the outer wall of the gear shaft; A limiting component, the limiting component is arranged in the cylinder body and is used to limit the limiting block; An adjusting assembly, the adjusting assembly is arranged on the cylinder body and is located below the limiting assembly, and the adjusting assembly can adjust the speed at which the left piston and the right piston move in the cylinder body through the limiting assembly; The limiting assembly includes a first air cylinder and a second air cylinder fixed on the side wall of the cylinder body, a first limiting cavity and a first air collecting cavity are provided in the first air cylinder, a first piston is slidably connected in the first limiting cavity, one end of the first piston is fixedly connected to a first piston rod, one end of the first piston rod extending out of the first air cylinder is movably connected to the side wall of the limiting block, a first elastic member is provided in the first air collecting cavity, a first fixing rod is provided in the first air cylinder, one end of the first elastic member is connected to an end of the first piston away from the first piston rod, the other end of the first elastic member is connected to an end of the first fixing rod located in the first air cylinder, and a first connecting hole connected to the first air collecting cavity is provided on the outer wall of the first air cylinder; A second limiting cavity and a second air collecting cavity are provided in the second air cylinder, a second piston is slidably connected in the second limiting cavity, one end of the second piston is fixedly connected to a second piston rod, one end of the second piston rod extending out of the second air cylinder is movably connected to a side wall of the limiting block, a second elastic member is provided in the second air collecting cavity, a second fixing rod is provided in the second air cylinder, one end of the second elastic member is connected to an end of the second piston away from the second piston rod, the other end of the second elastic member is connected to an end of the second fixing rod located in the second air cylinder, and a second connecting hole connected to the second air collecting cavity is provided on the outer wall of the second air cylinder; The regulating assembly includes a guide member fixed on the side of the cylinder body, the cylinder body is provided with a first channel and a second channel, the guide member is provided with a first air inlet hole and a second air inlet hole connected with the first channel and the second channel, the first air inlet hole and the second air inlet hole are both connected with the inner cavity of the cylinder body, and the first air inlet hole is connected with the chamber between the left piston and the right piston in the cylinder body, and the second air inlet hole is connected with the chamber between the left piston and the left end cover in the cylinder body and the chamber between the right piston and the right end cover; The guide member is provided with a first guide groove and a second guide groove on both sides, the first guide groove is connected to the first air inlet hole, the second guide groove is connected to the second air inlet hole, a first slider is slidably connected in the first guide groove, and a second slider is slidably connected in the second guide groove; The third air cylinder and the fourth air cylinder are fixedly connected to the two sides of the guide member respectively, a third piston is slidably connected in the third air cylinder, one end of the third piston is fixedly connected to a third piston rod, one end of the third piston rod extending out of the third air cylinder is fixedly connected to the first slider, a third elastic member is sleeved on the outer wall of the third piston rod, one end of the third elastic member is connected to the inner wall of the third air cylinder, the other end of the third elastic member is connected to an end of the third piston close to the third piston rod, and a third connecting hole is opened at an end of the third air cylinder away from the third piston rod; The third communicating hole is connected with the first communicating hole through a pipeline.

2. A valve pneumatic actuator according to claim 1, characterized in that: A fourth piston is slidably connected inside the fourth air cylinder, a fourth piston rod is fixedly connected to one end of the fourth piston, one end of the fourth piston rod extending out of the fourth air cylinder is fixedly connected to the second slider, a fourth elastic member is sleeved on the outer wall of the fourth piston rod, one end of the fourth elastic member is connected to the inner wall of the fourth air cylinder, the other end of the fourth elastic member is connected to an end of the fourth piston close to the fourth piston rod, and a fourth connecting hole is provided at an end of the fourth air cylinder away from the fourth piston rod.

3. A valve pneumatic actuator according to claim 2, characterized in that: The fourth communicating hole is connected with the second communicating hole through a pipeline.

4. A valve pneumatic actuator according to claim 1, characterized in that: A valve is fixedly connected to the bottom of the cylinder body, and a valve stem of the valve is connected to a slot provided on the gear shaft.

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