JP2010276057A - Swing check valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swing check valve for checking a backflow by quickly closing a valve element 8 when stopping operation, by holding the valve element 8 in large opening in operation of an aeration blower. <P>SOLUTION: A cylinder device 21 is attached to an outer wall of a valve casing 7, and a valve rod 9 for rockably supporting the valve element 8 and a piston 23 of the cylinder device 21 are connected by a connecting mechanism, and opening-closing operation of the valve element 8 and reciprocating motion of the piston 23 are interlocked. A cylinder chamber 24 for expanding the volume by the movement of the piston 23 interlocking with opening operation of the valve element 8 is communicated with the upstream side of the valve element 8 by a communicating flow passage 25, and a three-way ball valve 26 is interposed in this communicating flow passage 25. An operation member 35 operating so as to overturn to the downstream side at a preset flow rate or more and rise at the preset flow rate or less, is arranged on the downstream side of the valve element 8 in the valve casing 7. The three-way ball valve 26 communicates the communicating flow passage 25 with a cylinder chamber 24 by overturning to the downstream side of a flapper 36 of the operation member 35, and the three-way ball valve 26 communicates the communicating flow passage 25 with the atmosphere by rising of the flapper 36. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a swing check valve provided in a flow path for preventing a reverse flow by flowing a fluid in the flow path only in one direction. The present invention relates to an improved swing check valve that can close a valve body quickly and prevent reverse flow in the event of a power failure or power failure.

  An example of a conventional swing check valve will be described with reference to FIG. FIG. 9 is a longitudinal sectional view showing a structure of an example of a conventional swing check valve. In FIG. 9, the swing check valve 3 is configured such that a valve body 8 is swingably supported by a valve rod 9 in a valve box 7, and the valve body 8 is in a direction opposite to the direction in which a fluid flows as shown by a solid line. It is configured to swing by its own weight and come into close contact with the valve seat 10 to be in a closed state. And as shown with the broken line, the valve body 8 is comprised so that it may be pushed open against the force of self-weight, may be rock | fluctuated in the direction which flows a fluid, and may be in an open state. In such a configuration, if the pressure of the fluid on the upstream side is higher than that on the downstream side, the valve element 8 swings away from the valve seat 10 by the pressure difference to allow the fluid to pass. If the pressure of the fluid on the downstream side is higher than that on the upstream side, the valve body 8 swings in the direction opposite to the direction in which the fluid flows by the pressure difference and the weight of the valve body 8 and comes into close contact with the valve seat 10. Thus preventing the passage of fluid in the reverse direction.

  The swing check valve 3 having such a structure is incorporated in a piping system as shown in FIG. 10, for example. FIG. 10 is an example of a piping system in which a swing check valve is incorporated. A plurality of aeration blowers 1, 1 are connected to the collecting pipe 5 via the swing check valves 3, 3 and the air supply valves 4, 4 downstream thereof, and the other end of the collecting pipe 5 is pluralized. It branches and is connected to the diffuser 6, 6, 6, 6 respectively.

  In the above-described conventional swing check valve 3, when the upstream side is at a higher pressure than the downstream side, the valve body 8 is pushed open by the pressure difference so that the valve body 8 is opened. Since the self-weight of 8 acts in the closing direction, the force for pushing the valve body 8 is small, so that the valve body 8 cannot be opened to the fully open position, and the valve body 8 is held at an intermediate opening. As a result, the flow path area is narrowed by the valve body 8 and the flow path resistance is increased, resulting in a problem that pressure loss is generated accordingly. In addition, since the valve body 8 is at an intermediate opening position in the normal state, the valve body 8 may swing due to a change in the wind speed of the aeration blower 1, and the bearing of the valve stem 9 may be worn out, resulting in malfunction. there were. Further, when the operation of the aeration blowers 1 and 1 is stopped, the pressure on the downstream side becomes higher than the upstream side, and the valve body 8 is suddenly closed by the pressure difference and the weight of the valve body 8, so There was a problem that the valve body 8 and the valve seat 10 were damaged due to collision. In particular, when one aeration blower 1 among a plurality of aeration blowers 1 and 1 is stopped and the operation of the other aeration blower 1 is continued, the swing check valve communicates with the stopped aeration blower 1. 3 is a problem in that the pressure of the other aeration blower 1 that is continuously operated on the downstream side is applied, the upstream side is suddenly lower than the downstream side, and the valve body 8 collides violently with the valve seat 10 as described above. Will occur.

In order to improve these problems, the present applicant previously proposed Japanese Patent Application Laid-Open No. 20006-266416. The technology proposed earlier is as follows. In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box 7 and the valve body of the swing check valve 3 is provided. The valve body 9 that swingably supports the valve 8 in the open state and the closed state and the piston of the cylinder device are coupled by a coupling mechanism so that the opening / closing operation of the valve body 8 and the reciprocating movement of the piston are interlocked. 8 is connected to the cylinder chamber of the cylinder device whose volume is expanded when the valve body 8 is opened via the communication flow path, and the flow rate of the fluid flowing into and out of the cylinder chamber is adjusted to the communication flow path. The flow rate adjusting means is provided. With this configuration, the valve rod 9 that supports the valve body 8 in a swingable manner and the piston of the cylinder device are connected by a connecting mechanism, and the flow rate adjusting means is provided in the flow path of the fluid flowing into and out of the cylinder chamber. The flow rate of the fluid flowing into and out of the chamber is controlled so that the fluid cannot flow in and out instantaneously, and gradually flows in and out at the set flow rate. The slow operation of the piston of this cylinder device is Acting as a brake against the swing, the swing of the valve body 8 becomes slow. Therefore, even if the pressure on the downstream side from the upstream side temporarily increases suddenly, the valve body 8 does not collide violently with the valve seat 10. Even when a surging phenomenon occurs, the valve body 8 cannot swing in response to surging pulsation and vibration, and the valve body 8 does not swing back and forth violently. However, it does not repeatedly hit the valve seat 10 repeatedly. Further, the cylinder chamber is expanded by the upstream pressure, the opening of the valve body 8 is increased, and the flow path resistance can be reduced.
JP 2006-266416 A

  By the way, even if the operation of the aeration blowers 1 and 1 is stopped, the pressure upstream of the valve body 8 may not immediately decrease. For example, in the technique disclosed in Japanese Patent Application Laid-Open No. 2006-266416, since the compressed air in the cylinder chamber is discharged to the upstream side through the communication flow path, the pressure drop on the upstream side is delayed accordingly. Thus, if the upstream pressure remains without decreasing immediately, the pressure difference between the upstream side and the downstream side of the valve body 8 becomes small, and the valve body 8 moves slowly in the closing direction. . Further, since the compressed air in the cylinder chamber of the cylinder device is discharged to the upstream side through the flow rate adjusting means, the flow rate that can be discharged is regulated, and the cylinder device acts as a brake for the closing operation of the valve body 8, Closing of the body 8 is slow. Therefore, there is a possibility that a reverse flow may occur from the downstream side to the upstream side. Due to this reverse flow, the impellers of the aeration blowers 1 and 1 are reversely rotated, and the oil pump of the lubrication device interlocked with the impellers is also reversely rotated, resulting in insufficient oil supply, which may cause damage to the blower bearing.

  The present invention has been made in view of the circumstances as described above, and can maintain the valve body at a large opening degree during operation of a blower or the like, and closes the valve body quickly at the time of operation stop or a sudden power failure to prevent backflow. An object of the present invention is to provide a swing check valve that can be prevented.

  The present invention has been made to solve the above-described problems, and the swing check valve of the present invention is provided in the flow path in order to flow the fluid in the flow path only in one direction and prevent the reverse flow. In the swing check valve, a cylinder device is attached to the outer wall of the valve box, and a valve rod for swingably supporting the swing check valve in an open state and a closed state and a piston of the cylinder device are connected to each other. The cylinder chamber of the cylinder device is connected so that the opening / closing operation of the valve body and the reciprocating movement of the piston are interlocked, and the volume is increased by the movement of the piston interlocking with the opening operation of the valve body. The flow path communicates with the upstream side of the valve body, a switching valve is provided in the communication flow path, and the flow rate downstream of the valve body in the valve box downstream of the valve body is lower than the set flow rate. Falls below the set flow rate An actuating member that operates to stand is provided, and the switching valve causes the upstream side of the valve body and the cylinder chamber to communicate with each other by the overturning of the actuating member to the downstream side, and the actuation The operation member and the switching valve are connected so that the switching valve communicates the communication channel to the atmosphere and the cylinder chamber communicates to the atmosphere when the member stands up.

  Further, in the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve of the swing check valve is provided. A valve rod that supports the body in an open state and a closed state so as to be swingable and a piston of the cylinder device are connected by a connection mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are linked, The cylinder chamber of the cylinder device that expands the volume by the movement of the piston interlocked with the opening operation of the valve body is connected to the upstream side of the valve body through a communication flow path, a branch pipe is provided in the communication flow path, and the branch An open / close valve is provided in the pipe, and the operating member operates to fall in the valve box downstream from the valve body when the flow rate downstream of the fluid is higher than a set flow rate, and to stand up below the set flow rate. The actuating member The operation is performed so that the on-off valve is closed by the overturning to the downstream side, and the on-off valve is opened by the standing of the operating member so that the communication flow path is communicated with the atmosphere via the first branch pipe. You may comprise a member and the said on-off valve connected.

  In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve of the swing check valve A valve rod that supports the body in an open state and a closed state so as to be swingable and a piston of the cylinder device are connected by a connection mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are linked, The cylinder chamber of the cylinder device, which expands the volume by movement of the piston in conjunction with the opening operation of the valve body, is connected to the upstream side of the valve body through a communication channel, and an electromagnetic or electric switching valve is connected to the communication channel. An actuating member is provided in the valve box so as to fall downstream when the flow rate of the fluid downstream of the valve body is higher than a set flow rate and to stand up when the flow rate is lower than the set flow rate. On the outside of the box An electrical switch that is turned ON / OFF by the overturning and standing of the moving member is provided, and the switching valve is moved through the communication channel by the operation of the electrical switch by the overturning to the downstream side of the operating member. The upstream side of the valve body and the cylinder chamber are communicated with each other, and the switching valve is communicated with the atmosphere by the operation of the electrical switch by the standing of the operating member, whereby the cylinder chamber is communicated with the atmosphere. It can also be constituted so that it can communicate with.

  Further, in the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve of the swing check valve A valve rod that supports the body in an open state and a closed state so as to be swingable and a piston of the cylinder device are connected by a connection mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are linked, The cylinder chamber of the cylinder device that expands the volume by the movement of the piston interlocked with the opening operation of the valve body is connected to the upstream side of the valve body through a communication flow path, a branch pipe is provided in the communication flow path, and the branch An electromagnetic or electric on-off valve is provided in the pipe, and when the flow rate of the fluid downstream of the valve body in the valve box on the downstream side of the valve body is higher than a set flow rate, it falls down and rises below the set flow rate. Actuating member An electric switch that is turned on / off by the overturning and standing of the operating member is provided outside the valve box, and the on / off valve is operated by the electric switch by the overturning to the downstream side of the operating member. The open / close valve is opened by the operation of the electrical switch by the standing of the actuating member, and the communication flow path can be communicated with the atmosphere via the branch pipe. is there.

  Further, the electromagnetic or electric switching valve may be configured to communicate the communication channel with the atmosphere when the energization is interrupted.

  In addition, the electromagnetic or electric on-off valve can be configured to open when energization is interrupted and to connect the communication channel to the atmosphere via the branch pipe.

  Furthermore, a flapper is provided on the operating member so that the flapper can be tumbled and tilted, and a spring that elastically biases the flapper to stand up is provided. If the flow rate of the fluid downstream is equal to or higher than a set flow rate, It may be configured such that the flapper falls to the downstream side against the bias, and the flapper stands up by the elastic bias of the spring below the set flow rate.

  In the swing check valve according to claim 1, the operating member falls when the flow of the fluid in the flow channel exceeds the set flow rate and rises below the set flow rate, and communicates with the operation of the operating member. Since the switching valve provided in the passage is switched, if the blower or the like is operated and there is a flow rate higher than the set flow rate, the operating member falls and the switching valve applies high upstream pressure to the cylinder chamber via the communication channel. It is made to flow in and the opening degree of a valve body is kept large. When the operation of the blower, etc. is stopped and the flow rate falls below the set flow rate, the operation member rises and the switching valve communicates the communication flow path with the atmosphere, and immediately decreases the pressure upstream of the valve body and the pressure in the cylinder chamber. Can be. Thus, the valve body is immediately closed to prevent backflow.

  In the swing check valve according to the second aspect, as in the first aspect, the operation member falls when the flow of the fluid in the flow channel falls above the set flow rate and rises below the set flow rate. Since the on-off valve provided in the branch pipe of the communication channel is opened and closed in conjunction with the operation of the member, if the blower or the like is operated and there is a flow rate higher than the set flow rate, the operating member falls and the on-off valve is closed Then, high pressure on the upstream side is caused to flow into the cylinder chamber via the communication channel, and the opening degree of the valve body is kept large. When the operation of the blower or the like is stopped and the flow rate is equal to or lower than the set flow rate, the operating member is erected to open the on-off valve, the communication channel is communicated to the atmosphere via the branch pipe, The pressure in the cylinder chamber can be immediately reduced. Thus, the valve body is immediately closed to prevent backflow.

  In the swing check valve according to the third aspect, the operating member falls when the fluid flow in the flow channel falls above the set flow rate and rises below the set flow rate, and interlocks with the operation of the actuating member. The electrical switch is turned on and off, and the electromagnetic or electric switching valve provided in the communication flow path is switched by this electrical switch operation. When the member falls, the switching valve causes the upstream side high pressure to flow into the cylinder chamber via the communication flow path, and the opening degree of the valve body is kept large. Then, when the operation of the blower or the like is stopped and the flow rate is lower than the set flow rate, the switching valve causes the communication flow path to communicate with the atmosphere by raising the operation member, and immediately reduces the pressure on the upstream side of the valve body and the pressure in the cylinder chamber. obtain. Therefore, as in the first aspect, the valve body is immediately closed to prevent backflow.

  Furthermore, in the swing check valve according to claim 4, the operating member falls when the flow of the fluid in the flow channel falls above the set flow rate and rises below the set flow rate, and interlocks with the operation of the operating member. The electrical switch is turned ON / OFF, and the operation of this electrical switch opens or closes the electromagnetic or electric on-off valve provided in the branch pipe of the communication flow path. If there is, the on-off valve is closed by the overturning of the operating member, and high upstream pressure is caused to flow into the cylinder chamber via the communication flow path, so that the opening degree of the valve body is kept large. Then, when the operation of the blower or the like is stopped and the flow rate is lower than the set flow rate, the on-off valve is opened by the standing of the operating member, and the branch pipe is connected to the atmosphere, so that the communication channel is connected to the atmosphere. The side pressure and the pressure in the cylinder chamber can be immediately reduced. Therefore, as in the second aspect, the valve body is immediately closed to prevent backflow.

  Further, in the swing check valve according to claim 5, since the electromagnetic or electric switching valve is made to communicate with the atmosphere when the energization is interrupted, the energization is interrupted. Immediately, the pressure on the upstream side of the valve body and the pressure in the cylinder chamber decrease. Therefore, the valve body is immediately closed when the energization is interrupted to prevent backflow.

  In the swing check valve according to claim 6, the electromagnetic or electric on-off valve is opened when the energization is cut off, and the communication flow path is communicated with the atmosphere via the branch pipe. Therefore, as soon as power is cut off, the pressure on the upstream side of the valve body and the pressure in the cylinder chamber decrease. Therefore, similarly to the fifth aspect, the valve body is immediately closed when the energization is interrupted, and the backflow can be prevented.

  The swing check valve according to claim 7 is provided with a spring that elastically biases the flapper provided on the actuating member so as to stand up, and resists the elastic biasing of the spring when the flow rate exceeds the set flow rate. Since the flapper falls to the downstream side and the flapper is raised by the elastic bias of the spring below the set flow rate, switching and opening / closing of the switching valve or on-off valve can be performed by appropriately setting the spring elasticity. Can be performed at an appropriate set flow rate. Moreover, the structure is simple.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an external view showing the structure of a first embodiment of the swing check valve of the present invention. FIG. 2 is a longitudinal sectional view of the swing check valve of the first embodiment. FIG. 3 is a diagram showing the structure of the operating member and the switching valve connected thereto. 4A and 4B are diagrams showing the movement of the valve body and the operating member and the state of the switching valve. FIG. 4A shows a state where the flow rate is equal to or higher than the set flow rate, and FIG. 4B shows a state where the flow rate is equal to or lower than the set flow rate. 1 to 4, the same or equivalent members as those in FIGS. 9 and 10 are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 1, the main body of the swing check valve 20 is the same as the structure shown in FIG. Then, a cylinder device 21 is attached to the outer wall of the valve box 7 of the swing check valve 20, and the valve rod 9 and the cylinder device 21 that support the valve body 8 of the swing check valve 20 so as to be swingable between an open state and a closed state. The piston 23 is connected by a connecting rod 28 and a crank arm 29 so that the opening / closing operation of the valve body 8 and the reciprocating movement of the piston 23 are interlocked. The valve stem 9 penetrates the outer wall of the valve box 7 in an appropriate airtight state and protrudes outward. The crank arm 29 may be fixed so as not to rotate relative to the valve stem 9. The connecting mechanism including the connecting rod 28 and the crank arm 29 allows the opening / closing operation of the valve body 8 and the reciprocating movement of the piston 23 to be interlocked. Further, the upstream side of the valve body 8 is communicated with the cylinder chamber 24 of the cylinder device 21 whose volume is increased when the valve body 8 is opened via the communication flow path 25. Such a configuration is the same as that disclosed in Japanese Patent Laid-Open No. 2006-266416. The communication channel 25 is provided with a three-way ball valve 26 as a switching valve. The three-way ball valve 26 is configured to be switched between a state in which the upstream side of the valve body 8 communicates with the cylinder chamber 24 and a state in which the communication flow path 25 communicates with the atmosphere. A flow rate adjusting means 27 is provided in the communication flow path 25 on the upstream side of the three-way ball valve 26.

  Further, as shown in FIG. 2, an operating member 35 is disposed in the valve box 7 of the swing check valve 20 on the downstream side of the valve body 8. The actuating member 35 is provided with a flapper 36 integrally with a pin 37, and is pivotably disposed by the pin 37 so that the flapper 36 can fall down and stand up in the fluid flow direction. A coil spring 38 is externally fitted to the pin 37 and is elastically biased by the elasticity of the coil spring 38 so that the flapper 36 is in an upright state. If the flow rate flowing from the upstream side to the downstream side is equal to or greater than the set flow rate, the flapper 36 falls against the elasticity due to the flow pressure, and if the flow rate flows below the set flow rate, the flapper 36 stands up due to the elasticity. Is set as appropriate. Further, as shown in FIG. 3, one end of the pin 37 protrudes outward from the valve box 7 in an airtight state, and the end of the protruded pin 37 is connected to the valve rod of the three-way ball valve 26 via a flexible joint 39. 40. In addition, when the flapper 36 is overturned, the three-way ball valve 26 makes the communication flow path 25 conductive and the upstream pressure flows into the cylinder chamber 24. When the flapper 36 is upright, the three-way ball valve 26 is The communication channel 25 is configured to communicate with the atmosphere.

  In such a configuration, when an aeration blower (not shown) is activated, the pressure on the upstream side from the valve body 8 is increased, and the valve body 8 is opened by being pressed by the fluid pressure downstream, and from the upstream side to the downstream side. A flow occurs. If the flow rate is equal to or higher than the set flow rate, the flapper 36 falls to the downstream side against the elasticity of the coil spring 38 as shown in FIG. Then, the rotation caused by the fall of the flapper 36 rotates the valve rod 40 of the three-way ball valve 26 via the pin 37 and the flexible joint 39, the three-way ball valve 26 is switched, and the upstream side is connected via the communication channel 25. It communicates with the cylinder chamber 24. Then, the upstream pressure is applied to the cylinder chamber 24 via the communication channel 25, the volume thereof is expanded, and the piston 23 is pushed upward in FIG. 4 (a). This upward movement of the piston 23 causes the valve rod 9 of the valve body 8 to rotate counterclockwise in FIG. 4 via the connecting rod 28 and the crank arm 29, thereby moving the valve body 8 in the fully open direction. The fully open state is maintained. As described above, while the aeration blower is in operation, the pressure upstream of the valve body 8 acts as a force pressing the valve body 8 downstream, and the upstream pressure applied to the cylinder chamber 24 causes the piston 23. Acts as a force for opening up the valve body 8. As a result, the opening degree of the valve body 8 can be increased and the large opening degree can be reliably maintained.

  Further, the flow rate adjustment by the flow rate adjustment valve 27 interposed in the communication flow path 25 regulates the flow rate flowing into the cylinder chamber 24, and the rising speed of the piston 23 is appropriately suppressed, and the valve body is moved by moving in the opening direction. 8 does not collide with the valve box 7 violently. In the first embodiment, the flow rate adjusting valve 27 is interposed in the communication channel 25 upstream of the three-way ball valve 26. However, the flow rate adjusting valve is located downstream of the three-way ball valve 26 in the cylinder chamber. It will be easily understood that the device may be interposed between the two. In addition, when this flow regulating valve is interposed between the three-way ball valve 26 and the cylinder chamber 24, the discharge of the compressed air in the cylinder chamber 24 becomes gentle and the closing of the valve body 8 becomes slow. Therefore, of course, the flow rate regulated by the flow rate adjustment valve should be set appropriately.

  When the aeration blower stops, the flow rate decreases. When the flow rate is equal to or lower than the set flow rate, the pressure due to the flow rate decreases and the flapper 36 is moved by the elasticity of the coil spring 38 as shown in FIG. Stand up. Then, the rotation of the flapper 36 standing up causes the valve rod 40 of the three-way ball valve 26 to rotate in the reverse direction via the pin 37 and the flexible joint 39, the three-way ball valve 26 is switched, and the communication flow path 25 is opened to the atmosphere. Communicated with Then, the pressure on the upstream side is discharged to the atmosphere through the communication flow path 25 and the compressed air in the cylinder chamber 24 is discharged to the atmosphere, the volume of the cylinder chamber 24 is reduced, and the piston in FIG. 23 is allowed to move downward. By allowing the piston 23 to move downward, the valve rod 9 of the valve body 8 is allowed to rotate in the reverse direction in the clockwise direction in FIG. 4 via the connecting rod 28 and the crank arm 29. The valve body 8 is allowed to move in the fully closed direction. Here, the force that has pressed the valve body 8 to the downstream side is decreased due to the decrease in the flow rate, and the valve body 8 comes into contact with the valve seat 10 of the valve box 7 by the dead weight of the valve body 8 to be fully closed. If the pressure on the downstream side of the valve body 8 is higher than that on the upstream side, the valve body 8 is strongly pressed against the valve seat 10 of the valve box 7 by the pressure on the downstream side, and a fully closed state is secured. Therefore, it acts as a check valve.

  Further, by providing a flow rate adjusting valve in the flow path where the three-way ball valve 26 communicates the communication flow path 25 to the atmosphere, the flow rate of the compressed air discharged from the cylinder chamber 24 is adjusted, and the valve body 8 is closed. It is also possible to adjust the speed to be adjusted. If the three-way ball valve 26 is provided in a flow path that communicates the communication flow path 25 to the atmosphere, the flow rate adjusting valve is configured to discharge the compressed air in the communication flow path 25 and the cylinder chamber 24 in the communication flow path 25. It becomes loose and the closing of the valve body 8 becomes slow. Therefore, of course, the flow rate regulated by the flow rate adjustment valve should be set appropriately.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing the movement of the valve body and the actuating member of the second embodiment of the swing check valve of the present invention and the state of the on-off valve, (a) shows the state where the flow rate is equal to or higher than the set flow rate, b) shows a state where the flow rate is equal to or lower than the set flow rate. In FIG. 5, the same or equivalent members as those in FIGS. 1 to 4, 9 and 10 are given the same reference numerals and redundant description is omitted.

  The second embodiment is different from the first embodiment in that the three-way ball valve 26 is not provided, the communication channel 25 is directly connected to the cylinder chamber 24, and the branch channel is further connected to the communication channel 25. 50, and an opening / closing ball valve 51 is provided in the branch pipe 50, and the valve rod 52 of the opening / closing ball valve 51 is interlocked with the operation of the flapper 36.

  In such a configuration, when the aeration blower is activated and a flow is generated from the upstream side to the downstream side, and the flow rate is equal to or higher than the set flow rate, the elasticity of the coil spring 38 is resisted as shown in FIG. Thus, the flapper 36 falls to the downstream side, and the rotation caused by the fall of the flapper 36 rotates the valve rod 52 of the open / close ball valve 51, the open / close ball valve 51 is closed, and the communication flow path 25 is shut off from the atmosphere. . Then, the upstream pressure is applied to the cylinder chamber 24 through the communication flow path 25, the volume thereof is expanded, the piston 23 is pushed upward, the valve body 8 is moved in the fully open direction, and the fully open state is maintained. Then, the flow rate adjustment by the flow rate adjustment valve 27 interposed in the communication flow path 25 regulates the flow rate flowing into the cylinder chamber 24, and the ascending speed of the piston 23 is appropriately suppressed. The body 8 does not collide violently with the valve box 7.

  When the aeration blower stops, the flow rate decreases. When the flow rate becomes equal to or lower than the set flow rate, the pressure due to the flow rate decreases as shown in FIG. The rotation of the flapper 36 by standing up causes the valve rod 52 of the open / close ball valve 51 to rotate in the reverse direction, the open / close ball valve 51 is opened, and the communication channel 25 communicates with the atmosphere via the branch pipe 50. Is done. Then, the pressure on the upstream side and the compressed air in the cylinder chamber 24 are discharged to the atmosphere via the communication channel 25, and the movement of the valve body 8 in the fully closed direction is allowed. Here, the force that has pressed the valve body 8 to the downstream side is decreased due to the decrease in the flow rate, and the valve body 8 comes into contact with the valve seat 10 of the valve box 7 by the dead weight of the valve body 8 to be fully closed. If the pressure on the downstream side of the valve body 8 is higher than that on the upstream side, the valve body 8 is strongly pressed against the valve seat 10 of the valve box 7 by the pressure on the downstream side, and a fully closed state is secured. Here, the upstream side of the valve body 8 is also communicated with the atmosphere via the communication channel 25, and the pressure on the upstream side can be quickly reduced. The valve body 8 is closed by adjusting the flow rate of the compressed air discharged from the cylinder chamber 24 by providing the flow rate adjusting valve in the flow path that allows the open / close ball valve 51 to communicate the communication flow path 25 with the atmosphere. The speed may be adjusted.

  A third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is an external view showing the structure of a third embodiment of the swing check valve of the present invention. FIG. 7 is a diagram illustrating the movement of the valve body and the operating member and the state of the switching valve according to the third embodiment. FIG. 7A illustrates a state where the flow rate is equal to or higher than the set flow rate, and FIG. Shows the state. 6 and 7, the same or equivalent members as those in FIGS. 1 to 5, 9, and 10 are assigned the same reference numerals, and redundant description is omitted.

  The third embodiment is different from the first embodiment in that a three-way solenoid valve 61 is provided in the communication flow path 25 in place of the three-way ball valve 26, and the three-way solenoid valve 61 is switched and controlled by the control device 60. The In addition, an electrical switch 55 such as a limit switch is provided outside the valve box 7. The pin 37 of the flapper 36 of the actuating member 35 is provided at one end passing through the valve box 7 so that the arm 57 does not rotate relatively. The fall of the flapper 36 causes the arm 57 to turn on / off the electrical switch 55. It is configured to switch the OFF operation.

  In such a configuration, when the aeration blower is activated and a flow is generated from the upstream side to the downstream side, and the flow rate becomes equal to or higher than the set flow rate, the elasticity of the coil spring 38 is resisted as shown in FIG. Then, the flapper 36 falls to the downstream side, and the rotation caused by the fall of the flapper 36 switches the electrical switch 55 to ON, and the control device 60 causes the three-way solenoid valve 61 to communicate the communication channel 25 with the cylinder chamber 24. Switch to. Then, the upstream pressure is applied to the cylinder chamber 24 via the communication channel 25, the volume thereof is expanded, the piston 23 is pushed upward, the valve body 8 is moved in the fully open direction, and the fully open state is maintained.

  When the aeration blower stops, the flow rate decreases. When the flow rate is equal to or lower than the set flow rate, the pressure due to the flow rate decreases as shown in FIG. The rotation due to the standing up of the flapper 36 switches the electrical switch 55 to OFF, and the control device 60 switches the three-way electromagnetic valve 61 so that the communication channel 25 communicates with the atmosphere. Then, the pressure on the upstream side and the compressed air in the cylinder chamber 24 are discharged to the atmosphere via the communication channel 25, and the movement of the valve body 8 in the fully closed direction is allowed. Here, the force that has pressed the valve body 8 to the downstream side is decreased due to the decrease in the flow rate, and the valve body 8 comes into contact with the valve seat 10 of the valve box 7 by the dead weight of the valve body 8 to be fully closed.

  Here, when a sudden power outage that stops the aeration blower occurs, it may be desirable that the valve body 8 is quickly closed and fully closed. In such a case, the three-way solenoid valve 61 may be configured to communicate the communication flow path 25 to the atmosphere in a state where the control device 60 and the three-way solenoid valve 61 are not energized. In response to a sudden power failure, the upstream pressure and the compressed air in the cylinder chamber 24 are discharged to the atmosphere, and the valve body 8 is allowed to move in the fully closed direction.

  Further, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing the movement of the valve body and the actuating member of the fourth embodiment of the swing check valve of the present invention and the state of the switching valve. FIG. 8A shows the state where the flow rate is equal to or higher than the set flow rate. b) shows a state where the flow rate is equal to or lower than the set flow rate. 6 and 7, the same or equivalent members as those in FIGS. 1 to 5, 9, and 10 are assigned the same reference numerals, and redundant description is omitted.

  The fourth embodiment differs from the second embodiment in that an electric on-off valve 66 is provided in the branch pipe 50 of the communication flow path 25 in place of the on-off ball valve 26, and the electric on-off valve 66 is controlled by the control device 60. Is switched by. In addition, an electrical switch 55 such as a limit switch is provided outside the valve box 7. The pin 37 of the flapper 36 of the actuating member is provided at one end portion that penetrates the valve box 7 so that the arm 57 does not rotate relatively, and when the flapper 36 falls and stands, the arm 57 turns on / off the electrical switch 55. It is configured to switch operations.

  In such a configuration, when the aeration blower is started and a flow is generated from the upstream side to the downstream side, and the flow rate becomes equal to or higher than the set flow rate, the elasticity of the coil spring 38 is resisted as shown in FIG. Then, the flapper 36 falls to the downstream side, and the rotation caused by the fall of the flapper 36 switches the electrical switch 55 to ON, and the control device 60 closes the electric on-off valve 66 and passes through the communication channel 25. The pressure of the upstream flow path 45 is applied to the cylinder chamber 24, the volume thereof is expanded, the piston 23 is pushed upward, the valve body 8 is moved in the fully open direction, and the fully opened state is maintained.

  When the aeration blower stops, the flow rate decreases. When the flow rate is equal to or lower than the set flow rate, the pressure due to the flow rate decreases as shown in FIG. The rotation due to the rising of the flapper 36 switches the electrical switch 55 to OFF, and the control device 60 opens the electric on-off valve 66 to switch the communication channel 25 to the atmosphere. Then, the pressure on the upstream side and the compressed air in the cylinder chamber 24 are discharged to the atmosphere via the communication channel 25, and the movement of the valve body 8 in the fully closed direction is allowed. Here, the force that has pressed the valve body 8 to the downstream side is decreased due to the decrease in the flow rate, and the valve body 8 comes into contact with the valve seat 10 of the valve box 7 by the dead weight of the valve body 8 to be fully closed.

  Here, as in the third embodiment, when a sudden power outage that stops the aeration blower occurs, it may be desirable that the valve body 8 is quickly closed and fully closed. In such a case, the electric opening / closing valve 66 may be opened and the communication channel 25 may be communicated with the atmosphere in a state where the control device 60 and the electric opening / closing valve 66 are not energized. In response to a sudden power failure, the upstream pressure and the compressed air in the cylinder chamber 24 are discharged to the atmosphere, and the valve body 8 is allowed to move in the fully closed direction.

  In the above embodiment, the swing check valve of the present invention is not limited to the one in which gas flows in the flow path, but can be applied to the one in which liquid flows in the flow path. In the first embodiment, the three-way ball valve 26 is used. However, the present invention is not limited to this, and the communication flow path 25 is communicated with the cylinder chamber 24 in conjunction with the falling and rising of the flapper 36 of the operating member 35. A switching valve having any structure may be used as long as it can be switched between a state and a state communicating with the atmosphere. In the second embodiment, the open / close ball valve 51 is used. However, the present invention is not limited to this, and the communication channel 25 is blocked from the atmosphere in conjunction with the falling and rising of the flapper 36 of the operating member 35. An open / close valve of any structure may be used as long as it can be switched to a communication state. Further, in the third and fourth embodiments, the electrical switch 55 that is switched ON / OFF in conjunction with the falling and rising of the flapper 36 of the operating member 35 is not limited to the limit switch, and the falling and rising of the flapper 36 is performed. Any structure may be used as long as it is an electrical switch that provides an ON / OFF signal to the control device 60 in conjunction with the switch, and a proximity switch or the like may be used. In the third and fourth embodiments, instead of the three-way solenoid valve 61 and the electric on-off valve 66, an electromagnetic or electric switching valve that can be switched and controlled by the control device 60 in accordance with the ON / OFF signal of the electrical switch 55. Or what is necessary is just the structure of an on-off valve. Further, the connecting mechanism for connecting the valve rod 9 of the valve body 8 and the piston 23 is not limited to that of the above embodiment, and any structure can be used as long as the opening / closing operation of the valve body 8 and the reciprocating movement of the piston 23 are connected. The connection mechanism may be used. Further, the structure of the actuating member 35 is not limited to the structure in which the flapper 36 is disposed so as to be able to fall and stand up, and any structure may be used as long as the posture changes between the set flow rate and the set flow rate. Further, in the third and fourth embodiments, the electric switch 55 is turned on / off by the actuating member 35, and the control device 60 causes the three-way electromagnetic valve 61 and the electric on-off valve 66 by the ON / OFF signal. However, the present invention is not limited to this, and the electrical switch 55 may be switched between energization and shut-off of the three-way solenoid valve 61 and the electric on-off valve 66 to act as the control device 60.

It is an external view which shows the structure of 1st Example of the swing check valve of this invention. It is a longitudinal cross-sectional view of the swing check valve of 1st Example. It is a figure which shows the structure of an operation member, and the switching valve connected with it. It is a figure which shows the motion of a valve body and an operation member, and the state of a switching valve, (a) shows the state where a flow rate is more than a setting flow rate, (b) shows the state where a flow rate is below a setting flow rate. It is a figure which shows the state of the valve body of the 2nd Example of the swing check valve of this invention, the action | operation member, and the state of an on-off valve, (a) shows the state where a flow volume is more than a setting flow volume, (b) is flow volume. Indicates a state below the set flow rate. It is an external view which shows the structure of 3rd Example of the swing check valve of this invention. It is a figure which shows the state of the valve body of 3rd Example, an operation member, and the state of a switching valve, (a) shows the state where a flow volume is more than a setting flow volume, (b) shows the state where a flow volume is below a setting flow volume. . It is a figure which shows the state of the valve body of 4th Example of the swing check valve of this invention, the action | operation member, and the state of a switching valve, (a) shows the state where a flow volume is more than setting flow volume, (b) is flow volume. Indicates a state below the set flow rate. It is a longitudinal cross-sectional view which shows the structure of an example of the conventional swing check valve. It is an example of the piping system in which a swing check valve is incorporated.

DESCRIPTION OF SYMBOLS 1 Aeration blower 3, 20 Swing check valve 4 Air supply valve 5 Collecting pipe 6 Air diffuser 7 Valve box 8 Valve body 9, 40, 52 Valve rod 10 Valve seat 21 Cylinder device 23 Piston 24 Cylinder chamber 25 Communication flow path 26 Three-way ball valve 27 Flow control valve 28 Connecting rod 29 Crank arm 35 Actuating member 36 Flapper 37 Pin 38 Coil spring 39 Flexible joint 40 Valve rod 50 Branch pipe 51 Opening and closing ball valve 52 Valve rod 55 Electrical switch 57 Arm 60 Control device
61 Three-way solenoid valve 66 Electric on-off valve

Claims (7)

In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve body of the swing check valve is mounted A valve rod that is swingably supported in an open state and a closed state and a piston of the cylinder device are coupled by a coupling mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are interlocked. The cylinder chamber of the cylinder device that expands the volume by the movement of the piston interlocked with the opening operation of the cylinder communicates with the upstream side of the valve body through a communication channel, and a switching valve is provided in the communication channel, An operating member is provided on the downstream side of the valve body so as to fall to the downstream side when the flow rate to the downstream side of the fluid is higher than a set flow rate and to stand up below the set flow rate. The switching valve at the fall The upstream side of the valve body and the cylinder chamber are communicated with each other via the communication channel, and the switching valve communicates the communication channel to the atmosphere by the standing of the operating member, thereby communicating the cylinder chamber to the atmosphere. A swing check valve characterized in that the actuating member and the switching valve are connected to each other. In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve body of the swing check valve is mounted A valve rod that is swingably supported in an open state and a closed state and a piston of the cylinder device are coupled by a coupling mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are interlocked. The cylinder chamber of the cylinder device that expands the volume by movement of the piston in conjunction with the opening operation of the cylinder is connected to the upstream side of the valve body through a communication channel, and a branch pipe is provided in the communication channel, An on-off valve is provided, and an actuating member is provided in the valve box so as to fall downstream when the flow rate of the fluid downstream of the valve body is higher than a set flow rate and to stand up when the flow rate is lower than the set flow rate. , Downstream of the actuating member The operating member to close the open / close valve by the overturning to open, and to open the open / close valve by the standing of the operating member and to communicate the communication channel to the atmosphere via the branch pipe. A swing check valve characterized by connecting the on-off valve. In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve body of the swing check valve is mounted A valve rod that is swingably supported in an open state and a closed state and a piston of the cylinder device are coupled by a coupling mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are interlocked. The cylinder chamber of the cylinder device that expands the volume by movement of the piston interlocked with the opening operation of the cylinder is communicated to the upstream side of the valve body through a communication channel, and an electromagnetic or electric switching valve is provided in the communication channel, An actuating member is provided in the valve box so as to fall downstream when the flow rate downstream of the valve body is lower than a set flow rate and to stand up when the flow rate is lower than the set flow rate. The actuating member on the outside An electrical switch that is turned ON / OFF by the falling and standing is provided, and the switching valve is moved through the communication channel by the operation of the electrical switch by the falling to the downstream side of the operating member. The cylinder chamber is communicated with the upstream side and the cylinder chamber is communicated with the switching valve by communicating the communication channel with the atmosphere by the operation of the electrical switch by the standing of the operating member. A swing check valve characterized by being configured as described above. In the swing check valve provided in the flow path for flowing the fluid in the flow path only in one direction to prevent the reverse flow, a cylinder device is attached to the outer wall of the valve box, and the valve body of the swing check valve is mounted A valve rod that is swingably supported in an open state and a closed state and a piston of the cylinder device are coupled by a coupling mechanism so that the opening / closing operation of the valve body and the reciprocating movement of the piston are interlocked. The cylinder chamber of the cylinder device that expands the volume by movement of the piston in conjunction with the opening operation of the cylinder is connected to the upstream side of the valve body through a communication channel, and a branch pipe is provided in the communication channel, An electromagnetic or electric opening / closing valve is provided, and operates so that the flow rate downstream of the valve body in the valve box falls to the downstream side when the flow rate is equal to or higher than the set flow rate, and rises below the set flow rate. Provide actuating member, front An electrical switch that is turned ON / OFF by the overturning and standing up of the operating member is provided outside the valve box, and the open / close valve is closed by the operation of the electrical switch by the overturning to the downstream side of the operating member. And the open / close valve is opened by the operation of the electrical switch by the standing of the actuating member, and the communication flow path is communicated with the atmosphere via the first branch tube. Stop valve. 4. The swing check valve according to claim 3, wherein the electromagnetic or electric switching valve is configured to communicate the communication flow path with the atmosphere when energization is interrupted. 5. The swing check valve according to claim 4, wherein the electromagnetic or electric on-off valve is configured to open when energization is cut off and to connect the communication flow path to the atmosphere via the branch pipe. Swing check valve characterized by. 5. The swing check valve according to claim 1, wherein a flapper is provided on the actuating member so as to be able to fall and stand up, and a spring that is elastically biased to stand up the flapper is provided on the downstream side of the fluid. When the flow rate to the flow rate is equal to or higher than the set flow rate, the flapper falls to the downstream side against the elastic bias of the spring, and when the flow rate is equal to or lower than the set flow rate, the flapper stands up due to the elastic bias of the spring. A swing check valve.