A pneumatic cylinder type straight three-way butterfly valve and its usage method

Abstract

The present invention discloses a pneumatic cylinder type straight three-way butterfly valve and its usage method, belonging to the field of butterfly valves. A pneumatic cylinder type straight three-way butterfly valve replaces the fixed sealing ring on the butterfly plate with an adjustable sealing airbag. By simply inflating and deflating the sealing airbag, the sealing and non-sealing functions of the sealing airbag can be achieved. On the one hand, the sealing effect can be improved. On the other hand, before the operation of opening and closing the butterfly plate, the sealing airbag is in a deflated state, which can avoid the abrasion of the sealing airbag caused by the rotation of the opening and closing butterfly plate, and can greatly extend the service life of the sealing airbag. By setting a receiving groove on the circumferential side end of the butterfly plate and elastic protective rings on the opposite sides of the sealing airbag, when the butterfly plate is in the open state, the sealing airbag is received in the receiving groove, and the protective ring blocks the outside of the sealing airbag, playing a protective role for the sealing airbag to prevent the passing fluid from directly impacting the sealing airbag.

Description

Technical Field

[0001] The present invention relates to the field of butterfly valves, and more specifically, to a pneumatic cylinder type positive three-way butterfly valve and a using method thereof. Background Art

[0002] A pneumatic butterfly valve is composed of a pneumatic actuator and a butterfly valve. The pneumatic butterfly valve uses a circular butterfly plate that rotates with the valve stem for opening and closing to achieve the opening and closing action of a pneumatic valve. It is mainly used as a cut-off valve and can also be designed to have the function of adjustment or both cut-off and adjustment. The use of butterfly valves on low-pressure large and medium-diameter pipelines is increasing. The principle of the pneumatic butterfly valve lies in that it is used in combination with a YT positioner. The YT positioner is a device that receives a 4-20 mA DC current signal from a controller and delivers air to the pneumatic actuator to control the valve position.

[0003] In the prior art, in order to control the flow of fluid in a three-way valve, generally two butterfly valves are provided. The two butterfly valves respectively control the opening and closing of two of the pipelines. The butterfly valve uses the sealing ring on the circumferential side of its circular butterfly plate to achieve the interception of the pipeline. During the rotation of the butterfly plate sealing ring with the valve stem, it will frequently slide against the inner wall of the butterfly housing, causing wear of the sealing ring and resulting in a decrease in the sealing performance. Summary of the Invention

[0004] 1. Technical Problems to be Solved

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a pneumatic cylinder type positive three-way butterfly valve and a using method thereof, which can improve the sealing effect, avoid the wear of the sealing airbag during the rotation of the opening and closing butterfly plate, and can greatly extend the service life of the sealing airbag.

[0006] 2. Technical Solutions

[0007] To solve the above problems, the present invention adopts the following technical solutions.

[0008] A pneumatic cylinder type positive three-way butterfly valve includes a valve body, a control mechanism, and a pneumatic actuator. The control mechanism, the pneumatic actuator, and the valve body are connected in sequence, and the control mechanism delivers air into the pneumatic actuator through an air duct I to adjust the state of the valve body. The valve body includes a valve housing, a butterfly plate, and a valve stem;

[0009] The butterfly plate is located inside the valve housing. The upper end of the valve stem is connected to the pneumatic actuator. The lower end of the valve stem movably penetrates through the valve housing and is fixed to the side end of the butterfly plate. A sealing airbag is sleeved on the circumferential side of the butterfly plate;

[0010] An air guide hole is provided inside the valve stem. The control mechanism is connected to the end of the valve stem away from the pneumatic actuator through the second air guide pipe, and the second air guide pipe is communicated with the air guide hole. An air hole 1 communicated with the air guide hole is provided on the side wall of the valve stem. An air hole 2 corresponding to the air hole 1 is provided at the center of the butterfly plate. A plurality of air guide channels communicated with the air hole 2 are arranged in a circumferential array along the radial direction of the butterfly plate. A fixed pipe is fixedly penetrated through the sealing airbag, and the fixed pipe is fixedly inserted into the air guide channel. The usage method is as follows:

[0011] a: When the butterfly plate is in the closed state, the control mechanism controls the second air guide pipe to convey air into the valve stem. The air flow passes through the air guide hole and the air guide channel in sequence, and finally is introduced into the sealing airbag, so that the sealing airbag expands. The outer wall of the expanded sealing airbag abuts against the inner wall of the valve housing, forming a stable sealing effect;

[0012] b: Before opening the butterfly plate, the control mechanism controls the second air guide pipe to recover the air in the sealing airbag. The sealing airbag loses air and becomes deflated, and its outer wall does not contact the inner wall of the valve housing. At this time, the control mechanism is used to convey air into the pneumatic actuator through the first air guide pipe to drive the valve stem to rotate the butterfly plate and open the butterfly plate;

[0013] c: After closing the butterfly plate again, the control mechanism controls the second air guide pipe to convey air into the valve stem. The air flow passes through the air guide hole and the air guide channel in sequence, and finally is introduced into the sealing airbag, so that the sealing airbag expands. The outer wall of the expanded sealing airbag abuts against the inner wall of the valve housing, forming a stable sealing effect again.

[0014] Furthermore, a storage groove adapted to the sealing airbag is provided at the circumferential side end of the butterfly plate. The storage groove is used to store the sealing airbag. When the butterfly plate is in the open state, the sealing airbag is stored in the storage groove, which can effectively reduce the impact and wear of the passing fluid on the sealing airbag. Sealing gaskets are fixedly connected to the inner wall of the valve housing and the inner wall of the storage groove. When the sealing airbag is in the expanded state, the friction on the surface of the sealing airbag can be reduced.

[0015] Furthermore, a leak detection ball is connected to the second air guide pipe. The leak detection ball includes an elastic balloon and a rigid transparent spherical shell. The elastic balloon is fixedly communicated with the second air guide pipe. The rigid transparent spherical shell is sleeved outside the elastic balloon and fixedly connected to the second air guide pipe. The color of the elastic balloon is different from the colors of other structures on the periphery, and a fluorescent coating is applied on the surface of the elastic balloon. When the second air guide pipe inflates and deflates the sealing airbag, the elastic balloon is also inflated and deflated. The expansion and contraction of the elastic balloon are consistent with those of the sealing airbag. The staff can know the state of the sealing airbag by observing the state of the elastic balloon. When the sealing airbag inside the three-way valve leaks accidentally, the elastic balloon will also deflate immediately, playing a role in prompting the staff that the sealing airbag leaks. In addition, the fluorescent coating applied on the surface of the elastic balloon enables the elastic balloon to still play a prominent prompting role in a dim environment. The rigid transparent spherical shell can play a role in protecting and limiting the elastic balloon.

[0016] Further, a thickened layer is provided on the outer ring portion of the sealing airbag, and the thickened layer is integrally formed with the sealing airbag. The position of the outer ring portion of the sealing airbag frequently contacts the inner wall of the valve housing, and the thickened layer can improve the anti-wear performance of the sealing airbag.

[0017] Further, a first sealing ring is fixedly connected to the center of the end face of the butterfly plate close to the valve stem. The first sealing ring surrounds the outside of the second air hole, and the first sealing ring is in tight contact with the valve stem. The first sealing ring seals the peripheries of the first air hole and the second air hole to prevent air leakage.

[0018] Further, a second sealing ring is fixedly sleeved on the outer end of the fixed pipe. The second sealing ring is arranged in a manner that fits the sealing airbag. A sealing groove adapted to the second sealing ring is provided on the side end of the butterfly plate. On the one hand, the second sealing ring can seal the periphery of the air guiding channel, and on the other hand, it can also reduce the wear caused by the part of the butterfly plate at the port of the air guiding channel to the sealing airbag.

[0019] Further, an annular groove one is provided on the outer wall of the fixed pipe. A glue injection hole communicating with the air guiding channel is provided on the butterfly plate, and the glue injection hole corresponds to the annular groove one. After inserting the fixed pipe into the air guiding channel, inject an adhesive from the glue injection hole so that the adhesive fills the annular groove one. After curing, stable fixation between the fixed pipe and the air guiding channel is achieved, and at the same time, the sealing performance between the fixed pipe and the air guiding channel can be enhanced.

[0020] Optionally, an annular groove two is provided on the inner wall of the air guiding channel. The annular groove two corresponds to the annular groove one. The setting of the annular groove two in cooperation with the annular groove one enables the adhesive to fill both the annular groove one and the annular groove two at the same time, which can further improve the stable fixation between the fixed pipe and the air guiding channel.

[0021] Further, protective rings are provided on both opposite sides of the sealing airbag, and the protective rings are made of an elastic material. Both protective rings are inclined towards the side of the sealing airbag. The protective rings are fixedly connected to the butterfly plate. The protective rings can play a protective role for the sealing airbag when the butterfly plate is opened and the sealing airbag is in a deflated state, preventing the passing fluid from directly impacting the sealing airbag.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] (1) In this solution, the fixed sealing ring on the butterfly plate is replaced with an adjustable sealing airbag. By inflating and deflating the sealing airbag, the sealing and non-sealing functions of the sealing airbag are realized. On the one hand, the sealing effect can be improved. On the other hand, before the operations of opening and closing the butterfly plate, the sealing airbag is in a deflated state, which can avoid the wear caused to the sealing airbag during the rotation of opening and closing the butterfly plate, and can greatly extend the service life of the sealing airbag;

[0025] (2) In this solution, a storage groove adapted to the sealing airbag is provided at the circumferential side end of the butterfly plate. The storage groove is used to store the sealing airbag. When the butterfly plate is in the open state, the sealing airbag is stored in the storage groove, which can effectively reduce the impact and wear of the passing fluid on the sealing airbag.

[0026] (3) In this solution, sealing washers are fixedly connected to the inner wall of the valve housing and the inner wall of the storage groove. When the sealing airbag is in the inflated state, the friction on the surface of the sealing airbag can be reduced.

[0027] (4) In this solution, a thickened layer is provided on the outer ring part of the sealing airbag. The position of the outer ring part of the sealing airbag frequently contacts the inner wall of the valve housing, and the thickened layer can improve the anti-wear performance of the sealing airbag.

[0028] (5) In this solution, a first sealing ring is fixedly connected to the center of the end face of the butterfly plate close to the valve stem. The first sealing ring seals the circumferences of the first air hole and the second air hole to prevent air leakage. A second sealing ring is fixedly sleeved on the outer end of the fixed pipe. On the one hand, the second sealing ring can seal the circumference of the air guiding channel, and on the other hand, it can also reduce the wear of the part of the butterfly plate at the port of the air guiding channel on the sealing airbag.

[0029] (6) In this solution, a leakage detection ball including an elastic balloon and a hard transparent spherical shell is connected to the second air guiding pipe. The color of the elastic balloon is different from the colors of other structures on the circumference, which is more eye-catching. When the second air guiding pipe inflates and deflates the sealing airbag, the elastic balloon is also inflated and deflated. The inflation and deflation of the elastic balloon are consistent with those of the sealing airbag. The staff can know the state of the sealing airbag by observing the state of the elastic balloon. When the sealing airbag inside the three-way valve leaks accidentally, the elastic balloon will also deflate immediately, playing a role in prompting the staff that the sealing airbag leaks. In addition, the fluorescent coating applied on the surface of the elastic balloon enables the elastic balloon to still play an eye-catching prompting role in a dim environment. The hard transparent spherical shell can protect and limit the elastic balloon.

[0030] (7) In this solution, a first annular groove is provided on the outer wall of the fixed pipe, and a corresponding glue injection hole is provided on the butterfly plate. After inserting the fixed pipe into the air guiding channel, the adhesive is injected from the glue injection hole so that the adhesive fills the first annular groove. After curing, the stable fixation between the fixed pipe and the air guiding channel is realized, and at the same time, the sealing performance between the fixed pipe and the air guiding channel can be enhanced.

[0031] (8) In this solution, a second annular groove is provided on the inner wall of the air guiding channel. The setting of the second annular groove in cooperation with the first annular groove enables the adhesive to fill both the first annular groove and the second annular groove at the same time, which can further improve the stable fixation between the fixed pipe and the air guiding channel.

[0032] (9) In this solution, elastic protective rings are provided on opposite sides of the sealed airbag. The protective rings can protect the sealed airbag when the butterfly plate is opened and the sealed airbag is in a deflated state, preventing the fluid passing through from directly impacting the sealed airbag. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 is a schematic diagram of the structure of the valve body of the present invention;

[0035] Figure 3 is a schematic diagram of the split structure of the butterfly plate and the sealed airbag of the present invention;

[0036] Figure 4 is Figure 3 an enlarged schematic diagram of part A in

[0037] Figure 5 is a schematic diagram of the internal structure of the butterfly plate of the present invention;

[0038] Figure 6 is Figure 5 an enlarged schematic diagram of part B in

[0039] Figure 7 is a schematic diagram of the split structure of the butterfly plate and the valve stem of the present invention;

[0040] Figure 8 is a schematic diagram of the side structure of the butterfly plate of the present invention;

[0041] Figure 9 is a demonstration diagram of the sealed airbag from inflation to deflation of the present invention.

[0042] Description of the reference numerals in the drawings:

[0043] 1. Valve body; 101. Valve housing; 102. Butterfly plate; 103. Valve stem; 104. Sealed airbag; 105. Receiving groove; 106. Air hole I; 107. Sealing ring I; 108. Air guiding channel; 109. Air hole II; 110. Fixed pipe; 111. Annular groove I; 112. Annular groove II; 113. Glue injection hole; 114. Sealing groove; 115. Sealing ring II; 116. Protective ring; 117. Air guiding hole; 118. Thickened layer; 119. Sealing gasket; 2. Control mechanism; 3. Pneumatic actuator; 4. Air guiding pipe I; 5. Air guiding pipe II; 6. Leakage detection ball. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Embodiment 1:

[0048] Please refer to Figure 1 , a pneumatic cylinder type right three-way butterfly valve, which includes a valve body 1, a control mechanism 2 and a pneumatic actuator 3 applied to the cylinder type right three-way. The control mechanism 2, the pneumatic actuator 3 and the valve body 1 are connected in sequence. The pneumatic butterfly valve is used in combination with a YT positioner. The control mechanism 2 includes a YT positioner and a controller. The YT positioner receives a 4-20 mA DC current signal from the controller and conveys air to the pneumatic actuator 3 through an air duct 1 to adjust the state of the valve body 1.

[0049] Please refer to Figure 2 , the valve body 1 includes a valve housing 101, a butterfly plate 102 and a valve stem 103. The valve housing 101, the butterfly plate 102 and the valve stem 103 all adopt common models in the prior art.

[0050] Among them, the butterfly plate 102 is located inside the valve housing 101. The upper end of the valve stem 103 is connected to the pneumatic actuator 3. The lower end of the valve stem 103 movably penetrates the valve housing 101 and is fixed to the side end of the butterfly plate 102. The valve stem 103 can rotate in the valve housing 101, thereby driving the butterfly plate 102 to rotate synchronously in the valve housing 101.

[0051] Please refer to Figure 3 , a sealing airbag 104 is sleeved on the circumferential side of the butterfly plate 102. The sealing airbag 104 is made of an elastic material with good tolerance performance. Specifically, it is selected according to the actual application environment of the butterfly valve.

[0052] An air guide hole 117 is arranged inside the valve stem 103. Please refer to Figure 1 , the control mechanism 2 is connected to the end of the valve stem 103 away from the pneumatic actuator 3 through the second air guide pipe 5, and the second air guide pipe 5 is communicated with the air guide hole 117. An air hole 106 communicated with the air guide hole 117 is arranged on the side wall of the valve stem 103. An air hole 109 corresponding to the air hole 106 is arranged at the center of the butterfly plate 102. A plurality of air guide channels 108 communicated with the air hole 109 are arranged in a circumferential array along the radial direction of the butterfly plate 102. A fixing pipe 110 is fixedly penetrated through the sealing airbag 104, and the fixing pipe 110 is fixedly inserted into the air guide channel 108. The second air guide pipe 5 is used in cooperation with the air guide hole 117, the air guide channel 108 and the fixing pipe 110 to inflate and deflate the sealing airbag 104, so as to realize the sealing and non-sealing functions of the sealing airbag 104.

[0053] By replacing the fixed sealing ring on the butterfly plate 102 with the adjustable sealing airbag 104, the sealing and non-sealing functions of the sealing airbag 104 can be realized only by inflating and deflating the sealing airbag 104. On the one hand, the sealing effect can be improved. On the other hand, before the operations of opening and closing the butterfly plate 102, the sealing airbag 104 is in a deflated state, which can avoid the abrasion of the sealing airbag 104 caused by the rotation of the opening and closing butterfly plate 102, and can greatly extend the service life of the sealing airbag 104.

[0054] Please refer to Figure 3 , a receiving groove 105 adapted to the sealing airbag 104 is arranged at the circumferential side end of the butterfly plate 102. The receiving groove 105 is used to receive the sealing airbag 104. When the butterfly plate 102 is in the open state, the sealing airbag 104 is received in the receiving groove 105, which can effectively reduce the impact and abrasion of the passing fluid on the sealing airbag 104.

[0055] Please refer to Figure 9 , sealing washers 119 are fixedly connected to the inner wall of the valve housing 101 and the inner wall of the receiving groove 105. When the sealing airbag 104 is in the inflated state, the friction on the surface of the sealing airbag 104 can be reduced.

[0056] In addition, an air leakage detection ball 6 is connected to the second air duct 5. The air leakage detection ball 6 includes an elastic balloon and a rigid transparent spherical shell. The elastic balloon is fixedly communicated with the second air duct 5. The rigid transparent spherical shell is sleeved outside the elastic balloon and fixedly connected to the second air duct 5. The color of the elastic balloon is different from that of other structures on the periphery, and a fluorescent coating is applied on the surface of the elastic balloon. The color of the elastic balloon is different from that of other structures on the periphery, making it more eye-catching. When the second air duct 5 inflates and deflates the sealing airbag 104, the elastic balloon is also inflated and deflated. The expansion and contraction of the elastic balloon are consistent with those of the sealing airbag 104. The staff can know the state of the sealing airbag 104 by observing the state of the elastic balloon. When the sealing airbag 104 inside the three-way valve leaks accidentally, the elastic balloon will also deflate immediately, playing a role in prompting the staff that the sealing airbag 104 leaks. In addition, the fluorescent coating applied on the surface of the elastic balloon enables the elastic balloon to still play an eye-catching prompting role in a dim environment. The rigid transparent spherical shell can protect and limit the elastic balloon.

[0057] Please refer to Figure 8 , a thickened layer 118 is provided on the outer ring part of the sealing airbag 104, and the thickened layer 118 is integrally formed with the sealing airbag 104. The position of the outer ring part of the sealing airbag 104 frequently contacts the inner wall of the valve housing 101. The thickened layer 118 can improve the anti-wear performance of the sealing airbag 104; in addition, protective rings 116 are provided on both opposite sides of the sealing airbag 104, and the protective rings 116 are made of elastic material. Both protective rings 116 are inclined towards the side of the sealing airbag 104. The protective rings 116 are fixedly connected to the butterfly plate 102. The protective rings 116 can play a protective role for the sealing airbag 104 when the butterfly plate 102 is opened and the sealing airbag 104 is in a deflated state, preventing the passing fluid from directly impacting the sealing airbag 104.

[0058] Please refer to Figure 7 , a first sealing ring 107 is fixedly connected to the center of the end face of the butterfly plate 102 close to the valve stem 103. The first sealing ring 107 is made of rubber or silica gel. The first sealing ring 107 surrounds the outside of the second air hole 109, and the first sealing ring 107 is in tight contact with the valve stem 103. The first sealing ring 107 seals the peripheries of the first air hole 106 and the second air hole 109 to prevent air leakage.

[0059] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6, a second sealing ring 115 is fixedly sleeved at the outer end of the fixed pipe 110. The second sealing ring 115 is made of rubber or silica gel. The second sealing ring 115 is arranged in contact with the sealing airbag 104. A sealing groove 114 adapted to the second sealing ring 115 is arranged at the side end of the butterfly plate 102. On the one hand, the second sealing ring 115 can seal the periphery of the air guide channel 108, and on the other hand, it can also reduce the wear caused by the part of the butterfly plate 102 at the port of the air guide channel 108 to the sealing airbag 104.

[0060] Please refer to Figure 3 and Figure 4 , a first annular groove 111 is arranged on the outer wall of the fixed pipe 110. A glue injection hole 113 communicating with the air guide channel 108 is arranged on the butterfly plate 102, and the glue injection hole 113 corresponds to the first annular groove 111. After the fixed pipe 110 is inserted into the air guide channel 108, adhesive is injected from the glue injection hole 113 so that the adhesive fills the first annular groove 111. After curing, stable fixation between the fixed pipe 110 and the air guide channel 108 is achieved, and at the same time, the sealing performance between the fixed pipe 110 and the air guide channel 108 can be enhanced.

[0061] To further improve the fixation stability between the fixed pipe 110 and the air guide channel 108, a second annular groove 112 is arranged on the inner wall of the air guide channel 108. The second annular groove 112 corresponds to the first annular groove 111. The arrangement of the second annular groove 112 in cooperation with the first annular groove 111 enables the adhesive to fill both the first annular groove 111 and the second annular groove 112 simultaneously, further improving the stable fixation between the fixed pipe 110 and the air guide channel 108.

[0062] When installing this butterfly valve, first, after inserting the fixed pipe 110 into the air guide channel 108, inject adhesive from the glue injection hole 113 so that the adhesive fills the first annular groove 111 and the second annular groove 112. After curing, stable fixation between the fixed pipe 110 and the air guide channel 108 is achieved, and at the same time, the sealing performance between the fixed pipe 110 and the air guide channel 108 can be enhanced.

[0063] Install this butterfly valve on the barrel - type straight tee using the existing installation method. The usage method of this pneumatic barrel - type straight tee butterfly valve is as follows:

[0064] a: When the butterfly plate 102 is in the closed state, the control mechanism 2 controls the air delivery pipe two 5 to deliver air into the valve stem 103. The air flow passes through the air guide holes 117 and the air guide channel 108 in sequence, and finally is introduced into the sealing airbag 104, causing the sealing airbag 104 to expand. The outer peripheral wall of the expanded sealing airbag 104 abuts against the inner wall of the valve housing 101 to form a stable sealing effect;

[0065] b: Before opening the butterfly plate 102, the control mechanism 2 controls the second air duct 5 to recover the air in the sealing airbag 104. The sealing airbag 104 loses air and becomes deflated, and its outer peripheral wall does not contact the inner wall of the valve housing 101. At this time, the control mechanism 2 uses the first air duct 4 to convey air to the pneumatic actuator 3 to drive the valve stem 103 to rotate the butterfly plate 102 and open the butterfly plate 102. At this time, the fluid can flow through the gap between the valve housing 101 and the butterfly plate 102. The protective ring 116 blocks the outside of the sealing airbag 104 and plays a protective role for the sealing airbag 104 to prevent the passing fluid from directly impacting the sealing airbag 104;

[0066] c: After closing the butterfly plate 102 again, the control mechanism 2 controls the second air duct 5 to convey air into the valve stem 103. The air flow passes through the air guide holes 117 and the air guide channels 108 in sequence and finally enters the sealing airbag 104, causing the sealing airbag 104 to expand. The outer peripheral wall of the expanded sealing airbag 104 abuts against the inner wall of the valve housing 101, and a stable sealing effect is formed again.

[0067] Compared with the existing fixed sealing ring, in this solution, the fixed sealing ring on the butterfly plate 102 is replaced with an adjustable sealing airbag 104. By simply inflating and deflating the sealing airbag 104, the sealing and non-sealing functions of the sealing airbag 104 can be realized. On the one hand, the sealing effect can be improved. On the other hand, before the operations of opening and closing the butterfly plate 102, the sealing airbag 104 is in a deflated state, which can avoid the wear of the sealing airbag 104 caused during the rotation of the opening and closing butterfly plate 102, and can greatly extend the service life of the sealing airbag 104.

[0068] The above; only the preferred specific implementation manner of the present invention; but the protection scope of the present invention is not limited thereto; any person skilled in the art within the technical scope disclosed by the present invention; according to the technical solution of the present invention and its improved concept, equivalent replacement or change; should be covered by the protection scope of the present invention.

Claims

1. A pneumatic cylinder type straight three-way butterfly valve, comprising a valve body (1), a control mechanism (2) and a pneumatic actuator (3), wherein the control mechanism (2), the pneumatic actuator (3) and the valve body (1) are connected in sequence, and the control mechanism (2) conveys air into the pneumatic actuator (3) through a first air duct (4) to adjust the state of the valve body (1), and is characterized in that: The valve body (1) includes a valve housing (101), a butterfly plate (102) and a valve stem (103); The butterfly plate (102) is located inside the valve housing (101). The upper end of the valve stem (103) is connected to the pneumatic actuator (3). The lower end of the valve stem (103) movably penetrates the valve housing (101) and is fixed to the side end of the butterfly plate (102). A sealing airbag (104) is sleeved on the circumferential side of the butterfly plate (102); An air guide hole (117) is arranged inside the valve stem (103). The control mechanism (2) is connected to the end of the valve stem (103) far from the pneumatic actuator (3) through an air guide pipe two (5), and the air guide pipe two (5) is communicated with the air guide hole (117). An air hole one (106) communicated with the air guide hole (117) is arranged on the side wall of the valve stem (103). An air hole two (109) corresponding to the air hole one (106) is arranged at the center of the butterfly plate (102). A plurality of air guide channels (108) communicated with the air hole two (109) are arranged in a circumferential array along the radial direction of the butterfly plate (102). A fixed pipe (110) is fixedly penetrated through the sealing airbag (104), and the fixed pipe (110) is fixedly inserted into the air guide channel (108); Protective rings (116) are arranged on both opposite sides of the sealing airbag (104), and the protective rings (116) are made of elastic material. Both of the two protective rings (116) are inclined towards the side of the sealing airbag (104), and the protective rings (116) are fixedly connected to the butterfly plate (102).

2. The pneumatic cylinder type straight three-way butterfly valve according to claim 1, characterized in that: A receiving groove (105) adapted to the sealing airbag (104) is arranged at the circumferential side end of the butterfly plate (102). Sealing gaskets (119) are fixedly connected to the inner wall of the valve housing (101) and the inner wall of the receiving groove (105).

3. The pneumatic cylinder type straight three-way butterfly valve according to claim 1, characterized in that: An air leakage detection ball (6) is connected to the air guide pipe two (5). The air leakage detection ball (6) includes an elastic balloon and a hard transparent spherical shell. The elastic balloon is fixedly communicated with the air guide pipe two (5). The hard transparent spherical shell is sleeved outside the elastic balloon and is fixedly connected to the air guide pipe two (5). The color of the elastic balloon is different from the colors of other structures on the periphery, and a fluorescent coating is coated on the surface of the elastic balloon.

4. The pneumatic cylinder type straight three-way butterfly valve according to claim 1, wherein: A thickening layer (118) is arranged on the outer ring part of the sealing airbag (104), and the thickening layer (118) is integrally formed with the sealing airbag (104).

5. The pneumatic cylinder type straight-through three-way butterfly valve according to claim 1, characterized in that: A sealing ring one (107) is fixedly connected to the center of the end face of the butterfly plate (102) close to the valve stem (103). The sealing ring one (107) surrounds the outside of the air hole two (109), and the sealing ring one (107) abuts against the valve stem (103).

6. The pneumatic cylinder type straight three-way butterfly valve according to claim 1, wherein: A sealing ring two (115) is fixedly sleeved on the outer end of the fixed pipe (110). The sealing ring two (115) is arranged in a manner of fitting the sealing airbag (104). A sealing groove (114) adapted to the sealing ring two (115) is arranged at the side end of the butterfly plate (102).

7. The pneumatic cylinder type straight three-way butterfly valve according to claim 6, wherein: An annular groove one (111) is provided on the outer wall of the fixed pipe (110). A glue injection hole (113) communicating with the air guide channel (108) is provided on the butterfly plate (102), and the glue injection hole (113) corresponds to the annular groove one (111).

8. The pneumatic cylinder type straight-through three-way butterfly valve according to claim 6, characterized in that: An annular groove two (112) is provided on the inner wall of the air guide channel (108), and the annular groove two (112) corresponds to the annular groove one (111).

9. A method for using a pneumatic cylinder type straight three-way butterfly valve according to any one of claims 1-8, characterized in that: It includes the following steps: a: When the butterfly plate (102) is in a closed state, the control mechanism (2) controls the air guide pipe two (5) to convey air into the valve stem (103). The air flow sequentially passes through the air guide holes (117) and the air guide channel (108), and finally is introduced into the sealing airbag (104), so that the sealing airbag (104) expands. The outer wall of the expanded sealing airbag (104) abuts against the inner wall of the valve housing (101) to form a stable sealing effect; b: Before opening the butterfly plate (102), the control mechanism (2) controls the air guide pipe two (5) to recover the air in the sealing airbag (104). The sealing airbag (104) loses air and becomes deflated, and its outer wall does not contact the inner wall of the valve housing (101). At this time, the control mechanism (2) conveys air into the pneumatic actuator (3) through the air guide pipe one (4) to drive the valve stem (103) to rotate the butterfly plate (102) and open the butterfly plate (102); c: After closing the butterfly plate (102) again, the control mechanism (2) controls the air guide pipe two (5) to convey air into the valve stem (103). The air flow sequentially passes through the air guide holes (117) and the air guide channel (108), and finally is introduced into the sealing airbag (104), so that the sealing airbag (104) expands. The outer wall of the expanded sealing airbag (104) abuts against the inner wall of the valve housing (101) to form a stable sealing effect again.

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