Pneumatic three-position multi-way valve

Abstract

The pneumatic three-position multi-way valve comprises a valve assembly and a pneumatic actuator, the valve assembly comprises a valve body assembly and a valve element assembly, the valve body assembly comprises a valve body and box bodies arranged on the periphery of the valve body, and pipe heads are arranged on the side face box body, the bottom box body and the top box body and used for medium inlet and outlet. The valve element assembly comprises a long valve element body and a short valve element body, the long valve element body and the short valve element body rotate synchronously, a plurality of open holes are formed in the surfaces of the long valve element body and the short valve element body respectively and used for being matched with pipe heads, and communicating holes are correspondingly formed in the valve body. The pipe head, the open hole and the communicating hole are matched to achieve medium inlet and outlet of different paths. According to the pneumatic three-position multi-way valve, multi-path medium inlet and outlet are achieved, use of various pipelines can be effectively guaranteed, and the service life of the pneumatic three-position multi-way valve is greatly prolonged through pressure compensation and auxiliary sealing; and secondly, the middle position hovering function is achieved through cooperation of different pistons and the cylinder body.

Description

Technical Field

[0001] The invention relates to the technical field of fluid equipment, and in particular to a pneumatic three-position multi-way valve. Background Art

[0002] Pneumatic three-way multi-way valve, also known as conversion valve or multi-position valve, is a commonly used control element that can realize switching control between multiple channels in a valve body. Pneumatic three-way multi-way valves are usually used to control the flow, pressure and direction in hydraulic systems, and are widely used in various fields such as machinery, aviation, aerospace, engineering machinery, rail transportation, etc. The working principle of the pneumatic three-way multi-way valve is to connect different flow channels to each other by rotating the valve core to achieve switching control of different fluid media. Pneumatic three-way multi-way valves are usually composed of valve body, valve core, spring, sealing ring, handle, actuator, etc. The internal shape of the valve body is designed according to different functional requirements, usually including inlet and outlet, central flow channel and multiple flow channel connection holes. The valve core is usually cylindrical, with multiple channels opened inside, and different channels can be connected to each other during rotation.

[0003] However, the existing pneumatic three-position multi-way valve has problems such as complex structure and short service life. Summary of the invention

[0004] The object of the present invention is to provide a pneumatic three-position multi-way valve to solve the above technical problems.

[0005] To achieve the above object, the present invention provides the following technical solutions: A pneumatic three-position multi-way valve, characterized in that it includes a valve assembly and a pneumatic actuator, the valve assembly includes a valve body assembly and a valve core assembly arranged in the valve body assembly, wherein the valve body assembly includes a valve body and a box body arranged around the valve body, the box body includes a side box body, a bottom box body and a top box body, wherein the side box body, the bottom box body and the top box body are provided with pipe heads for medium entry and exit, the valve core assembly includes a long valve core body and a short valve core body, wherein the long valve core body and the short valve core body rotate synchronously, and each surface is provided with a plurality of openings for adapting the pipe heads, wherein the valve body is correspondingly provided with connecting holes, the pneumatic actuator is used to drive the valve core assembly to rotate, and when the valve core assembly rotates, the pipe heads, the openings and the connecting holes cooperate to realize the entry and exit of media through different paths.

[0006] The present invention is further provided that the pneumatic actuator includes a cylinder body and end covers arranged at both ends of the cylinder body, the end covers include a first end cover and a second end cover, the first end cover is provided with a first air inlet hole, the second end cover is provided with a second air inlet hole, the cylinder body is provided with a third air inlet hole, the first end cover is provided with a first piston on the inner side of the first end cover, the second end cover is provided with a second piston on the inner side of the second end cover, wherein the first piston is connected to the third piston, a rack is provided between the second piston and the third piston, the rack is matched with a gear, the gear is provided on a corresponding gear shaft, the first piston and the third piston are fixedly connected, the gear shaft is connected to the valve core assembly and drives the valve core assembly to rotate, the first air inlet hole is used to drive the first piston to move when air is inletted, the second air inlet hole is used to drive the second piston to move when air is inletted, and the third air inlet hole is used to drive the third piston to move when air is inletted, and the second piston is provided with a push rod to limit the position of the third piston, wherein the first piston, the second piston and the third piston are used in combination to realize the change of the rotation angle of the gear shaft, that is, by changing the cylinder body, the cylinder body part where the second piston is provided and the length of the push rod, the change of the total stroke angle and the intermediate hovering angle is realized.

[0007] The present invention further provides that the valve assembly and the pneumatic actuator are connected via a flange, a linkage shaft connected to the gear shaft is provided in the flange, a bearing cover and a compensating sealing assembly are provided on the linkage shaft, thereby realizing the combination of the positioning function and the compensating sealing function of the cover.

[0008] The present invention is further arranged that the openings arranged on the long valve core body include a first type of openings and a second type of openings, the second type of openings include air-blocking openings provided with air-blocking plugs and air-venting openings provided with air-venting plugs, a yielding step is formed at the air-blocking openings, the air-blocking plug on the long valve core body is provided with a medium port for medium to pass through, the medium flows from the medium port to the yielding step, the medium acts on the air-blocking plug to cause it to deviate to one side of the valve body to achieve pressure sealing compensation.

[0009] The present invention is further arranged that a second type of openings is provided on the short valve core body, the second type of openings include air-blocking openings provided with air-blocking plugs and air-venting openings provided with air-venting plugs, a yielding step is provided at the air-blocking openings, an inlet port communicating with the yielding step is provided on the short valve core body, when the medium enters the yielding step from the inlet port, the medium acts on the air-blocking plug in the short valve core body to cause it to deviate to one side of the valve body to achieve pressure sealing compensation.

[0010] The present invention is further arranged that the two ends of the linkage shaft respectively form a first connection part connected to the gear shaft and a second connection part connected to the long valve core body, the first connection part and the second connection part are square shaft structures, wherein the first connection part and the second connection part are provided with fool-proof holes, and fool-proof fasteners are arranged in the fool-proof holes.

[0011] The present invention further provides that a concentric positioning step is provided between the actuator assembly and the valve assembly to ensure concentric transmission of the actuator output shaft and the valve stem.

[0012] The present invention further provides that a positioning copper sleeve is provided on the gear shaft, the positioning copper sleeve comprises an upper positioning copper sleeve and a lower positioning copper sleeve, and a step portion is formed on the gear shaft at the lower end of the upper positioning copper sleeve.

[0013] The present invention is further provided that a retaining ring opening is formed on both ends of the cylinder body, and a retaining ring groove is formed on the first end cover and the second end cover, the retaining ring groove is used to place a retaining ring connecting the cylinder body and the first end cover and the second end cover, wherein a pin hole is formed on the retaining ring groove, a limit pin is formed in the pin hole, and a limit groove cooperating with the limit pin is formed on the retaining ring. When the retaining ring is installed from the retaining ring opening, the first end cover or the second end cover is rotated, and the retaining ring is deformed along the retaining ring groove and installed into the retaining ring groove, and the limit groove cooperates with the limit pin to fix the retaining ring.

[0014] The present invention is further arranged that a vent plug of the same size is arranged opposite to each air-blocking plug to achieve symmetrical centering.

[0015] Beneficial effects of the present invention: The present invention combines a pneumatic actuator and a valve assembly, through the valve body of the valve assembly and a box body arranged around the valve body, wherein the box body includes a side box body, a bottom box body and a top box body, wherein the side box body, the bottom box body and the top box body are provided with pipe heads for medium entry and exit, the valve core assembly includes a long valve core body and a short valve core body, wherein the long valve core body and the short valve core body rotate synchronously, and a plurality of openings are provided on the surface of each for adapting the pipe head, wherein a connecting hole is correspondingly provided on the valve body, when the pneumatic actuator is used to drive the valve core assembly to rotate, when the valve core assembly rotates, the pipe head, the opening and the connecting hole cooperate to realize the medium entry and exit of different paths, and the medium entry and exit of multiple paths can effectively ensure the use of multiple pipelines, thereby reducing the use demand of a single pipeline, and through pressure compensation and auxiliary sealing, the service life of the pneumatic three-position multi-way valve is greatly increased; and the switching of pipelines is realized by the pneumatic actuator, and the angle range can be accurately adjusted, and the intermediate position hovering function is realized by different pistons cooperating with the cylinder body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 The figure is a schematic diagram of the explosion structure of an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of assembling an embodiment of the present invention.

[0018] Figure 3 It is a schematic structural diagram of a valve assembly according to an embodiment of the present invention.

[0019] Figure 4 Schematic diagram of the structure of a pneumatic actuator according to an embodiment of the present invention.

[0020] Figure 5 It is a schematic structural diagram of a flange according to an embodiment of the present invention.

[0021] Figure 6 It is a cross-sectional view of a flange according to an embodiment of the present invention.

[0022] Figure 7 It is a schematic structural diagram of a long valve core body according to an embodiment of the present invention.

[0023] Figure 8 It is a cross-sectional view of a long valve core body according to an embodiment of the present invention.

[0024] Fig. 9 It is a schematic structural diagram of a short valve core body according to an embodiment of the present invention.

[0025] Fig.10 It is a cross-sectional view of a short valve core body according to an embodiment of the present invention.

[0026] Fig.11 It is a schematic diagram of the structure of the end cover and the retaining spring according to an embodiment of the present invention.

[0027] Fig.12 4 is a cross-sectional view of a valve assembly according to an embodiment of the present invention.

[0028] Fig.13 for Fig.12 Enlarged view of point A in the middle.

[0029] Reference numerals: 10. Valve assembly; 101. Valve body assembly; 1011. Valve body; 10111. Connecting hole; 1012. Side box; 1013. Top box; 1014. Bottom box; 1015. Pipe head; 102. Valve core assembly; 1021. Long valve core body; 1022. Short valve core body; 1023. Second type of opening; 10231. Air-blocking opening; 10232. Ventilation opening; 1024. Air-blocking plug; 1025. Ventilation plug; 1026. First type of opening; 20. Pneumatic actuator; 201. Cylinder body; 202. First end cover; 203. Second end cover; 204. First piston; 205. Second piston; 206. Third piston; 207. Push rod; 208. Rack; 209. Gear; 2010. Gear shaft; 201 1. Cylinder body of the second piston; 30. Flange; 301. Outer shell; 302. Linkage shaft; 3021. First connecting part; 3022. Second connecting part; 303. Pressure cover; 304. Compensation spring; 305. Packing support ring; 306. Packing sealing ring; 307. Packing pressure ring; 40. First air inlet; 50. Second air inlet; 60. Third air inlet; 70. Make way step; 80. Medium port; 90. Inlet; 100. Foolproof hole; 110. Foolproof fastener; 120. Shaft groove; 130. Connecting shaft; 140. Upper positioning copper sleeve; 150. Lower positioning copper sleeve; 160. Circlip mouth; 170. Circlip; 180. Circlip groove; 190. Pin hole; 200. Limit pin; 210. Limit groove; 220. Step part; DETAILED DESCRIPTION

[0030] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0031] like Figure 1-Figure 13As shown, the present invention provides a pneumatic three-position multi-way valve, including a valve assembly 10 and a pneumatic actuator 20, wherein the valve assembly 10 includes a valve body assembly 101 and a valve core assembly 102 arranged in the valve body assembly 101, wherein the valve body assembly 101 includes a valve body 1011 and a box body arranged around the valve body 1011, wherein the box body includes a side box body 1012, a bottom box body 1014 and a top box body 1013, wherein the side box body 1012, the bottom box body 1014 and the top box body 1013 are provided with a pipe head 10 15 is used for medium entry and exit, the valve core assembly 102 includes a long valve core body 1021 and a short valve core body 1022, wherein the long valve core body 1021 and the short valve core body 1022 rotate synchronously, and a plurality of openings are arranged on the surface of each for adapting to the pipe head 1015, wherein a connecting hole 10111 is correspondingly arranged on the valve body 1011, and the pneumatic actuator 20 is used to drive the valve core assembly 102 to rotate, when the valve core assembly 102 rotates, the pipe head 1015, the opening and the connecting hole 10111 cooperate to realize the medium entry and exit of different paths.

[0032] In this embodiment, the pneumatic actuator 20 includes a cylinder body 201 and end covers arranged at both ends of the cylinder body 201, the end covers include a first end cover 202 and a second end cover 203, the first end cover 202 is provided with a first air inlet hole 40, the second end cover 203 is provided with a second air inlet hole 50, the cylinder body 201 is provided with a third air inlet hole 60, the inner side of the first end cover 202 is provided with a first piston 204, the inner side of the second end cover 203 is provided with a second piston 205, wherein the first piston 204 is connected to the third piston 206, a rack 208 is provided between the second piston 205 and the third piston 206, the rack 208 is provided with a gear 209 in cooperation, and the gear 209 is provided on the corresponding gear shaft 2010, The cross-sectional areas of the first piston and the third piston are consistent, and the cross-sectional area of ​​the second piston is larger than the cross-sectional areas of the first piston and the third piston; the first piston 204 and the third piston 206 are fixedly connected, the gear shaft 2010 is connected to the valve core assembly 102 and drives the valve core assembly 102 to rotate, the first air inlet 40 is used to drive the first piston 204 to move when air is inlet, the second air inlet 50 is used to drive the second piston 205 to move when air is inlet, and the third air inlet 60 is used to drive the third piston 206 to move when air is inlet, wherein the first piston 204, the second piston 205 and the third piston 206 are used in combination to achieve the change of the rotation angle of the gear shaft 2010, that is, by changing the length of the cylinder body, the cylinder body part 2011 of the second piston and the push rod 207, the change of the total stroke angle and the intermediate hovering angle is achieved. The push rod 207 is set on the second piston and faces the third piston, and its specific performance is as follows: When the first air inlet hole 40 is inletting air, the second air inlet hole 50 and the third air inlet hole 60 are not inletting air, and the first piston 204 moves toward the direction of the third piston 206, so that the gear shaft 2010 rotates by a first angle, and the maximum of the first angle is 180°; when the third air inlet hole 60 is inletting air, the first air inlet hole 40 and the second air inlet hole 50 are not inletting air, then the gear shaft 2010 rotates by a second angle, and the maximum of the second angle is 180°; when the first air inlet hole 40, the second air inlet hole 50 and the third air inlet hole 60 are inletting air at the same time, the second piston 205 moves toward the third piston 206, thereby realizing that the gear shaft 2010 rotates by a first angle, and the maximum of the first angle is 180°. The third piston 206 moves, and a limiting rod is provided on the third piston 206 for limiting the moving range of the third piston 206, and the size of the moving range is related to the length of the limiting rod. Therefore, the air intake and the length of the limiting rod can fix the gear shaft 2010 at a certain rotation angle within the range of 0-180°. According to the air intake state of different air inlet holes, the intermediate position hovering function of the pneumatic actuator 20 is realized. This intermediate position does not simply refer to the 90° position, but should be understood as any position within the range of 0-180.

[0033] In addition, since the linkage shaft 302 will be worn during rotation, which will lead to a decrease in the sealing effect and concentricity of the linkage shaft 302, the following method is adopted: A linkage shaft connected to the gear shaft is arranged in the flange. Based on the above situation, the valve assembly 10 and the pneumatic actuator 20 in this embodiment are connected through a flange 30, and the flange 30 includes an outer shell 301 and a linkage shaft 302 connected to the gear shaft 2010. The linkage shaft is provided with a bearing cover and a compensation seal assembly to realize the combination of the positioning function and the compensation seal function of the cover; specifically, the linkage shaft 302 is provided with a pressure cover 303, a compensation spring 304, a packing support ring 305, a packing seal ring 306, a packing pressure ring 307, and a packing pressure ring 308 in sequence from one side of the gear shaft 2010 to the other side of the valve assembly 10. 07, the compensation spring 304, the packing support ring 305, the packing sealing ring 306, and the packing pressure ring 307 constitute a compensation sealing assembly; wherein the packing sealing ring 306 is provided in plurality and is a V-shaped structure, wherein the pressure cover 303, the compensation spring 304, the packing support ring 305, the packing sealing ring 306, and the packing pressure ring 307 are used in combination to realize the compensation seal of the linkage shaft 302 during the rotation process and to ensure that the linkage shaft 302 will not be eccentric during the rotation process, wherein the compensation spring 304 adopts a wave spring, but other types of springs can also be used.

[0034] In this embodiment, the openings provided on the long valve core body 1021 include first-type openings 1026 and second-type openings 1023. The second-type openings 1023 include air-blocking openings 10231 provided with air-blocking plugs 1024 and air-venting openings 10232 provided with air-venting plugs 1025. A yielding step 70 is formed at the air-blocking openings 10231. The air-blocking plug 1024 on the long valve core body 1021 is provided with a medium port 80 for medium to pass through. The medium flows into the yielding step 70 from the medium port 80. The medium acts on the air-blocking plug 1024 to cause it to deviate toward the side of the valve body 1011 to achieve pressure sealing compensation.

[0035] Similarly, the short valve core body 1022 is provided with a second type of opening 1023, which includes a closed opening 10231 provided with a closed plug 1024 and a vent opening 10232 provided with a vent plug 1025. The closed opening 10231 is provided with a step 70, and the short valve core body 1022 is provided with an inlet 90 communicating with the step 70. When the medium enters the step 70 from the inlet 90, the medium acts on the closed plug 1024 in the short valve core body 1022 to deviate to the side of the valve body 1011 to achieve pressure sealing compensation. It is worth mentioning that opposite to each closed plug 1024, a vent plug 1025 of the same size is provided to achieve symmetrical centering, so that the loads of the long valve core body 1021 and the short valve core body 1022 are in a balanced state.

[0036] In addition, when the linkage shaft 302, the gear shaft 2010 and the long valve core body 1021 are installed, a round shaft is generally used in the prior art to realize the connection between the three. However, the round shaft structure has too high assembly precision requirements and often leads to misassembly during assembly. Based on the above situation, this embodiment provides the following technical solutions: The two ends of the linkage shaft 302 respectively form a first connecting part 3021 connected to the gear shaft 2010 and a second connecting part 3022 connected to the long valve core body 1021, and the first connecting part 3021 and the second connecting part 3022 are square shaft structures, wherein the first connecting part 3021 and the second connecting part 3022 are provided with an anti-fool hole 100, and the anti-fool hole 100 is provided with an anti-fool fastener 110. The square shaft structure is adopted and the anti-fool hole 100 is provided to cooperate with the anti-fool fastener 110, which can avoid the situation of wrong installation. In this embodiment, the anti-fool fastener 110 is a bolt.

[0037] In addition, when the long valve core body 1021 and the short valve core body 1022 are installed, there may be a mis-installation situation, so the following solution is adopted: the long valve core body 1021 is formed with an axis groove 120 on the side facing the short valve core body 1022, and the short valve core body 1022 is formed with a connecting shaft 130 on the side facing the long valve core body 1021. The connecting shaft 130 is a square shaft structure, and an anti-fool hole 100 is provided thereon, and an anti-fool fastener 110 is provided in the anti-fool hole 100. Similarly, the use of a square shaft structure and the provision of an anti-fool hole 100 in conjunction with the anti-fool fastener 110 can avoid the situation of mis-installation. In this embodiment, the anti-fool fastener 110 is a bolt.

[0038] In addition, a concentric positioning step is provided between the actuator assembly and the valve assembly to ensure the concentric transmission of the actuator gear shaft and the linkage shaft. Therefore, a positioning copper sleeve is provided on the gear shaft 2010, and the positioning copper sleeve includes an upper positioning copper sleeve 140 and a lower positioning copper sleeve 150. The gear shaft 2010 at the lower end of the upper positioning copper sleeve is formed with a step portion 220. The upper and lower positioning copper sleeves 150 cooperate with the step portion 220 to ensure that the gear shaft 2010 has a good centering effect.

[0039] In addition, when the end cover of the pneumatic actuator 20 is connected to the cylinder body 201, the existing technical means are all connected through bolts, but the vibration resistance of the bolt connection is relatively poor: the connection strength and stability of the bolt connection are subject to certain limitations, and it may easily become loose in applications with large vibrations, affecting the operating stability and life of the equipment.

[0040] Based on the above situation, in this embodiment, a clamping spring 170 is used to connect the end cover and the cover body, and the specific means are as follows: In this embodiment, retaining ring openings 160 are formed on both ends of the cylinder body 201, and retaining ring grooves 180 are formed on the first end cover 202 and the second end cover 203. The retaining ring grooves 180 are used to place retaining rings 170 connecting the cylinder body 201 and the first end cover 202 and the second end cover 203, wherein a pin hole 190 is formed on the retaining ring grooves 180, and a limiting pin 200 is formed in the pin hole 190, and a limiting groove 210 cooperating with the limiting pin 200 is formed on the retaining ring 170. When the retaining ring 170 is installed from the retaining ring openings 160, the first end cover 202 or the second end cover 203 is rotated, and the retaining ring 170 is deformed along the retaining ring grooves 180 and installed into the retaining ring grooves 180, and the limiting grooves 210 cooperate with the limiting pin 200 to fix the retaining ring 170.

[0041] The present invention combines a pneumatic actuator 20 and a valve assembly 10, wherein a valve body 1011 of the valve assembly 10 and a box body arranged around the valve body 1011, wherein the box body includes a side box body 1012, a bottom box body 1014 and a top box body 1013, wherein the side box body 1012, the bottom box body 1014 and the top box body 1013 are provided with a pipe head 1015 for medium inlet and outlet, and the valve core assembly 102 includes a long valve core body 1021 and a short valve core body 1022, wherein the long valve core body 1021 and the short valve core body 1022 rotate synchronously, and each surface is provided with a plurality of openings for adapting the pipe head 1015, wherein the valve body 10 A connecting hole 10111 is correspondingly arranged on 11. When the pneumatic actuator 20 is used to drive the valve core assembly 102 to rotate, when the valve core assembly 102 rotates, the pipe head 1015, the opening and the connecting hole 10111 cooperate to realize the entry and exit of media in different paths. The entry and exit of media in multiple paths can effectively ensure the use of multiple pipelines, thereby reducing the demand for the use of a single pipeline. Through pressure compensation and auxiliary sealing, the service life of the pneumatic three-position multi-way valve is greatly increased; and the pneumatic actuator 20 is used to switch the pipeline, and the angle range can be accurately adjusted. Secondly, the intermediate position hovering function is realized by different pistons cooperating with the cylinder body.

[0042] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0043] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0044] The above description shows and describes several preferred embodiments of the present invention, but as before, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept of this article through the above teachings or the technology or knowledge of the relevant field. And the changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A pneumatic three-position multi-way valve, characterized in that: It includes a valve assembly and a pneumatic actuator, the valve assembly includes a valve body assembly and a valve core assembly arranged in the valve body assembly, wherein the valve body assembly includes a valve body and a box body arranged around the valve body, the box body includes a side box body, a bottom box body and a top box body, wherein the side box body, the bottom box body and the top box body are provided with pipe heads for medium entry and exit, the valve core assembly includes a long valve core body and a short valve core body, wherein the long valve core body and the short valve core body rotate synchronously, and each surface is provided with a plurality of openings for adapting the pipe heads, wherein the valve body is correspondingly provided with connecting holes, the pneumatic actuator is used to drive the valve core assembly to rotate, and when the valve core assembly rotates, the pipe heads, the openings and the connecting holes cooperate to realize medium entry and exit through different paths.

2. A pneumatic three-position multi-way valve according to claim 1, characterized in that: The pneumatic actuator comprises a cylinder body and end covers arranged at both ends of the cylinder body, the end covers comprising a first end cover and a second end cover, the first end cover is provided with a first air inlet hole, the second end cover is provided with a second air inlet hole, the cylinder body is provided with a third air inlet hole, the first end cover is provided with a first piston on the inner side of the first end cover, the second end cover is provided with a second piston on the inner side of the second end cover, wherein the first piston is connected to the third piston, a rack is provided between the second piston and the third piston, the rack is provided with a gear in cooperation with the gear, the gear is provided on a corresponding gear shaft, the first piston and the third piston are fixedly connected, the gear shaft is connected to the valve core assembly and drives the valve core assembly to rotate, the first air inlet hole is used to drive the first piston to move when air is inletted, the second air inlet hole is used to drive the second piston to move when air is inletted, the third air inlet hole is used to drive the third piston to move when air is inletted, and the second piston is provided with a push rod to limit the position of the third piston, wherein the first piston, the second piston and the third piston are used in combination to realize the change of the rotation angle of the gear shaft, that is, by changing the cylinder body, the cylinder body part where the second piston is provided and the length of the push rod, the change of the total stroke angle and the intermediate hovering angle is realized.

3. A pneumatic three-position multi-way valve according to claim 1, characterized in that: The valve assembly is connected to the pneumatic actuator via a flange, a linkage shaft connected to the gear shaft is arranged in the flange, a bearing gland and a compensating seal assembly are arranged on the linkage shaft, so as to realize the combination of the positioning function and the compensating seal function of the gland.

4. A pneumatic three-position multi-way valve according to claim 1, characterized in that: The openings arranged on the long valve core body include a first type of openings and a second type of openings, the second type of openings include air-blocking openings provided with air-blocking plugs and air-venting openings provided with air-venting plugs, the air-blocking openings are formed with yielding steps, the air-blocking plug on the long valve core body is provided with a medium port for medium to pass through, the medium flows from the medium port to the yielding step, the medium acts on the air-blocking plug to cause it to deviate to one side of the valve body to achieve pressure sealing compensation.

5. The pneumatic three-position multi-way valve according to claim 1, characterized in that: The short valve core body is provided with a second type of openings, which include air-blocking openings provided with air-blocking plugs and air-venting openings provided with air-venting plugs. A yielding step is provided at the air-blocking openings. The short valve core body is provided with an inlet port connected to the yielding step. When the medium enters the yielding step from the inlet port, the medium acts on the air-blocking plug in the short valve core body to cause it to deviate to one side of the valve body to achieve pressure sealing compensation.

6. A pneumatic three-position multi-way valve according to claim 3, characterized in that: The two ends of the linkage shaft respectively form a first connection part connected to the gear shaft and a second connection part connected to the long valve core body. The first connection part and the second connection part are square shaft structures, wherein the first connection part and the second connection part are provided with anti-fool holes, and anti-fool fasteners are arranged in the anti-fool holes.

7. A pneumatic three-position multi-way valve according to claim 1, characterized in that: A concentric positioning step is provided between the actuator assembly and the valve assembly to ensure concentric transmission of the actuator gear shaft and the linkage shaft.

8. A pneumatic three-position multi-way valve according to claim 7, characterized in that: A positioning copper sleeve is arranged on the gear shaft, and the positioning copper sleeve comprises an upper positioning copper sleeve and a lower positioning copper sleeve, and a step portion is formed on the gear shaft at the lower end of the upper positioning copper sleeve.

9. A pneumatic three-position multi-way valve according to claim 2, characterized in that: A retaining ring opening is formed on both ends of the cylinder body, and a retaining ring groove is formed on the first end cover and the second end cover. The retaining ring groove is used to place a retaining ring connecting the cylinder body and the first end cover and the second end cover, wherein a pin hole is formed on the retaining ring groove, and a limit pin is formed in the pin hole. A limit groove that cooperates with the limit pin is formed on the retaining ring. When the retaining ring is installed from the retaining ring opening, the first end cover or the second end cover is rotated, and the retaining ring is deformed along the retaining ring groove and installed into the retaining ring groove, and the limit groove cooperates with the limit pin to fix the retaining ring.

10. A pneumatic three-position multi-way valve according to claim 5 or 6, characterized in that: Opposite each air-blocking plug, a venting plug of the same size is arranged to achieve symmetrical centering.

Images