JP7377009B2 - pinch valve - Google Patents

Description

The present invention relates to pinch valves.

a valve section, a tube body with a flow path formed therein and housed in the valve section, a pressing section that deforms the tube body by pressing or releasing the pressure to open and close the flow path; A pinch valve having a driving part that drives a part is well known (see, for example, Patent Document 1).

European Patent Application No. 2306055

In general, a tube made of an elastic material such as rubber may burst due to deterioration or minute scratches on the surface, and the fluid inside may leak out of the tube. The driving part of the pinch valve described in Patent Document 1 is an air actuator that drives the pressing part with air pressure, but the fluid that has flowed out of the pipe body is transferred to the outside of the pinch valve through an exhaust port or an intake port. Further leakage is possible. In particular, if the fluid is a chemical such as sulfuric acid that has an adverse effect on the human body, it is necessary to prevent the fluid from flowing out of the pinch valve.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pinch valve in which fluid inside the tube does not flow out of the pinch valve even if the tube ruptures.

According to one aspect of the present invention, there is provided a valve section, a tube body in which a flow path is formed and housed in the valve section, and a tube body that is deformed by pressing or releasing the pressure on the tube body. In the pinch valve, the pinch valve includes a pressing part that opens and closes the flow path, and a driving part that drives the pressing part, and seals fluid communication between a space near the outer surface of the pipe body and the outside of the pinch valve. A pinch valve is provided, further comprising a sealing portion.

The seal part has a first seal member, the valve part has a contact surface that comes into contact with an end surface of the tube, and the first seal is provided between the end surface of the tube and the contact surface. A sealing member may be provided. The seal portion may include a second seal member, and the second seal member may be provided between the valve portion and the drive portion. The seal portion includes a third seal member, the valve portion includes a main body member, and a holding member that holds the tube and is housed in the main body member, and the main body member and the holding member The third seal member may be provided between. The valve portion may include a main body member that holds the tube, a connecting member disposed at both ends of the main body member, and a cap nut that is screwed together with the connecting member at both ends of the main body member. good. The seal portion may include a fourth seal member, the drive portion may include a piston, and a base plate, and the fourth seal member may be provided between the piston and the base plate. The sealing member may be an O-ring. The first sealing member may be an annular projection formed on the abutment surface. The material of the valve portion may be plastic.

Aspects of the present invention have the common effect of providing a pinch valve in which the fluid inside the tube does not flow out of the pinch valve even if the tube ruptures.

FIG. 1 is a longitudinal sectional view of a pinch valve according to a first embodiment of the invention. FIG. 2 is an exploded perspective view of the pinch valve. FIG. 3 is an exploded perspective view of the holding member. FIG. 4 is a partially enlarged vertical sectional view of FIG. 1. FIG. 5 is a longitudinal sectional view showing the deformation of the tube. FIG. 6 is an enlarged vertical cross-sectional view of the pressing portion. FIG. 7 is another enlarged longitudinal cross-sectional view of the pressing portion. FIG. 8 is a diagram showing the relationship between curvature and fully closing pressing force. FIG. 9 is a diagram showing the relationship between curvature and strain. FIG. 10 is a diagram showing the relationship between the taper angle and the fully closing pressing force. FIG. 11 is a diagram showing the relationship between taper angle and strain. FIG. 12 is a diagram showing the relationship between the height of the support protrusion and the fully closing pressing force. FIG. 13 is a longitudinal sectional view of a pinch valve according to a second embodiment of the invention. FIG. 14 is an exploded perspective view of the pinch valve. FIG. 15 is a partially enlarged longitudinal sectional view of FIG. 13.

Embodiments of the present invention will be described in detail below with reference to the drawings. Corresponding components are given common reference numerals throughout the drawings.

FIG. 1 is a longitudinal sectional view of a pinch valve 1 according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view of the pinch valve 1, and FIG. 3 is an exploded perspective view of a holding member 21. The pinch valve 1 includes a valve part 2, a pipe body 3 (tube) in which a flow path is formed and accommodated in the valve part 2, and a pipe body 3 that can be opened by pressing or releasing the pressure on the pipe body 3. It has a pressing part 4 that deforms and opens and closes a flow path, and a driving part 5 that drives the pressing part 4. The tube body 3 is formed from an elastic material.

The drive unit 5 includes a cylinder 10, a piston 11 that is slidable within the cylinder 10, a base plate 12 disposed opposite to the piston 11, an indicator 13, a cap 14, an O-ring 15, and an O-ring. 16, an O-ring 17, and an O-ring 18. The drive unit 5 is an air actuator, and can move the piston 11 up and down in the cylinder 10 by supplying compressed air into the cylinder 10 from an air port (not shown) or exhausting it from the cylinder 10. The piston 11 has a shaft portion 19 that passes through the base plate 12. Therefore, the piston 11 moves up and down while being guided by the base plate 12. A pressing portion 4 is attached to the tip of the shaft portion 19. As the piston 11 moves up and down, the display 13 placed on the piston 11 moves in and out of the cylinder 10. Therefore, by visually confirming the state of protrusion and retraction of the indicator 13, it is possible to grasp the position of the piston 11, and by extension the position of the pressing part 4, that is, the open/closed state of the pinch valve 1.

The O-ring 15 is attached to the outer circumferential surface of the piston 11 and seals between the outer circumferential surface of the piston 11 and the inner circumferential surface of the cylinder 10. The O-ring 16 is attached to the outer peripheral surface of the base plate 12 and seals between the outer peripheral surface of the base plate 12 and the inner peripheral surface of the cylinder 10. The O-ring 17 is attached to the inner circumferential surface of the through hole of the base plate 12 and seals between the inner circumferential surface of the through hole of the base plate 12 and the outer circumferential surface of the shaft portion 19 of the piston 11. The O-ring 18 is attached to the outer peripheral surface of the indicator 13 and seals between the outer peripheral surface of the indicator 13 and the inner peripheral surface of the cylinder 10. Note that the drive unit 5 may be an electric actuator, or may be one that manually moves the piston 11 up and down.

The valve part 2 includes a cylindrical main body member 20, a holding member 21 that holds the pipe body 3 and is housed in the main body member 20, connecting members 22 arranged at both ends of the main body member 20, and the connecting members 22. It has cap nuts 23 that are screwed onto both ends of the main body member 20. The drive part 5 is attached to the valve part 2, specifically the main body member 20, by a screw 24. At this time, an O-ring 25 is disposed between the valve section 2 and the drive section 5, specifically between the base plate 12.

The holding member 21 includes an annular member 26 that holds each of the flange portions 6 formed at both ends of the tube body 3, and an upper support member 27 and a lower support member 28 that connect with each of the annular members 26. . A male thread is formed on the outer peripheral surface of the annular member 26, and is screwed into a female thread formed on the inner peripheral surface of the cap nut 23. In each of the annular members 26, an O-ring 29 is disposed inside the male thread when disposed in the tubular body 3. Therefore, an O-ring 29 is arranged between the main body member 20 and the holding member 21. The upper support member 27 and the lower support member 28 are combined so as to surround the middle part of the tube body 3, and are connected by a screw 30.

FIG. 4 is a partially enlarged vertical sectional view of FIG. 1. An annular recess 31 for receiving the flange portion 6 of the tubular body 3 is formed in the end face of the annular member 26 . An annular contact surface 32 that comes into contact with the inner annular end surface 8 of the flange portion 6 of the tube body 3 is formed on a surface corresponding to the bottom surface of the recess 31 . An annular projection 33 is formed on the contact surface 32 . The upper support member 27 and the lower support member 28 are connected to the annular member 26 in a state where the tube body 3 is slightly expanded in the axial direction. Therefore, each of the flange portions 6 of the tube body 3 is pressed against the contact surface 32 of the corresponding annular member 26, and the annular protrusion 33 of the annular member 26 is pressed against the end surface 8 of the flange portion 6 of the tube body 3. buried. As a result, the annular projection 33 seals between the end surface 8 of the flange portion 6 and the contact surface 32 of the annular member 26.

By the way, in general, a tube made of an elastic material such as rubber may burst due to deterioration or minute scratches on the surface, and the fluid inside may leak out of the tube. In particular, if the fluid is a chemical such as sulfuric acid that has an adverse effect on the human body, it is necessary to prevent the fluid from flowing out of the pinch valve. Additionally, for fluids that react with metals, such as sulfuric acid, metal parts cannot be used in the pinch valve. Therefore, it is necessary to use non-metallic parts, for example plastic parts, but plastic parts generally tend to have poor dimensional accuracy compared to metal parts, so Fluid is more likely to leak between parts than between parts.

The pinch valve 1 according to the first embodiment has, in addition to a primary seal for ensuring airtightness during normal use, a seal portion that is a secondary seal in case the tube body 3 ruptures. Thereby, even if the pipe body 3 ruptures, the fluid inside the pipe body 3 will not flow out to the outside of the pinch valve 1. Specifically, the pinch valve 1 includes, as seal parts, an annular protrusion 33 that is a first seal member, an O-ring 25 that is a second seal member, an O-ring 29 that is a third seal member, and a fourth seal. The pinch valve 1 has an O-ring 17 which is a member, and these seal the fluid communication between the space near the outer surface of the tube body 3 and the outside of the pinch valve 1. Note that the annular protrusion 33 may be replaced with an O-ring.

In this regard, referring to FIG. 4, the annular projection 33 seals between the end surface 8 of the flange portion 6 and the contact surface 32 of the annular member 26, thereby preventing leakage in the L1 direction. Furthermore, the O-ring 25 seals between the valve portion 2 and the drive portion 5, thereby preventing leakage in the L2 direction. Furthermore, the O-ring 29 seals between the main body member 20 and the holding member 21 to prevent leakage in the L3 direction. Furthermore, the O-ring 17 seals between the piston 11 and the base plate 12 to prevent leakage in the L4 direction. Furthermore, since O-rings and the like are used, consumable parts can be easily replaced.

As mentioned above, the pinch valve 1 according to the first embodiment uses an air actuator. The presence of the O-ring 17, which is the fourth sealing member, prevents the fluid that has flowed out of the tube from flowing into the cylinder 10, preventing damage to the drive unit, and preventing the exhaust port, intake port, etc. This prevents leakage of the pinch valve 1 to the outside through the pinch valve 1. Furthermore, even in the case of the pinch valve 1 in which the piston 11 is moved up and down manually instead of using an air actuator, the presence of the fourth seal member allows the fluid that has flowed out of the pipe body to further flow out to the outside of the pinch valve 1. It is prevented from doing so.

The seal portion is not limited to the seal member described above, and may be arbitrarily placed at a location where it is necessary to seal fluid communication between the space near the outer surface of the tube body 3 and the outside of the pinch valve 1. Further, the specific structure of the sealing member is not limited to an O-ring, and may be formed in any manner as long as sealing performance is ensured.

In the first embodiment, the drive unit 5 was attached to the holding member 21 that holds the tubular body 3 via the main body member 20, but it is directly attached to the holding member 21 without going through the main body member 20. It may also be attached to the other side. In this case, O-ring 29 is omitted. Similarly, the sealing member can be omitted by omitting or integrating each member.

The pinch valve 1, and in particular the valve part 2, can be made entirely of plastic material. For example, the cylinder 10, the piston 11, the base plate 12, and the lower support member 28 are made of glass-filled polypropylene (PPG), the pressing part 4 and the upper support member 27 are made of recycled polyvinylidene fluoride (recycled PVDF), and the main body The member 20, the connecting member 22, the cap nut 23, and the annular member 26 are made of polyvinyl chloride (U-PVC), the indicator 13 is made of acrylonitrile butadiene styrene (ABS), and the cap 14 is made of polypropylene. (PP), and the tubular body 3 is made of ethylene propylene diene rubber (EPDM) or fluororubber (FKM).

FIG. 5 is a longitudinal cross-sectional view showing the deformation of the tubular body 3. In FIG. 5, (A) shows the pinch valve 1 in a fully open state in an unpressurized state with no fluid flowing through the channel, and (B) shows the pinch valve 1 in a pressurized state with fluid flowing in the channel. (C) shows the fully closed state of the pinch valve 1 when there is no pressure when no fluid is flowing through the flow path, and (D) shows the fully closed state when the pinch valve 1 is under pressure when fluid is flowing through the flow path. The pinch valve 1 is shown in a fully closed state. Note that FIG. 5 is schematically drawn, and therefore, the base plate 12, the annular member 26, the upper support member 27, and the lower support member 28 are shown integrally as one support member.

As is clear from the comparison between FIGS. 5A and 5B, the tube body 3 in the fully open state when pressurized is not regulated by the pressing part 4 and the support member, specifically the upper support member 27. The part that is not there expands. Further, as is clear from a comparison between FIGS. 5C and 5D, the tube body 3 in the fully closed state when pressurized expands so as to come into closer contact with the outer surface of the pressing part 4.

Generally, by reducing the contact area where the pressing part contacts the tube, the pressure applied to the tube can be increased, and the pressing force required to close the flow path of the tube can be lowered. However, since the pressing force is concentrated on a portion of the tube and is applied repeatedly, the durability of the tube decreases. The optimal shapes of the pressing part 4 and the supporting member will be explained below.

FIG. 6 is an enlarged vertical cross-sectional view of the pressing portion 4. As shown in FIG. FIG. 6 is a diagram corresponding to (D) of FIG. The curvature of the tip of the pressing portion 4 that comes into contact with the tubular body 3 is defined as a curvature R. The center of curvature of the curvature R is arranged on the axis of symmetry in the cross section of the pressing part 4. The pressing part 4 has a curved part 4a and two straight parts 4b connected to the ends of the curved part 4a, respectively, in a longitudinal section in the axial direction of the tube body 3, and the angle formed by the two straight parts 4b is , the taper angle is defined as A. Therefore, the straight portion 4b is a tangent at the end of the curved portion 4a. The straight line portion 4b may not be a perfect straight line, but may be a curved line that is close to a straight line to the extent that it can be visually recognized as a straight line.

An upper support surface 34 is provided on the side of the pressing part 4 with respect to the axis C (FIG. 1) of the tubular body 3, that is, on the upper support member 27, for supporting the tubular body 3 except for a portion corresponding to the pressing part 4. ing. A lower support surface 35 for supporting the tube 3 is provided on the opposite side of the pressing part 4 with respect to the axis C of the tube 3, that is, on the lower support member 28. A support protrusion 36 is formed on the lower support surface 35 to cause a part of the tube body 3 to protrude toward the pressing portion 4 side. The support protrusion 36 is located at a position facing the tip of the pressing portion 4 and is formed across the tube body 3 in the transverse direction. The amount of protrusion from the lower support surface 35, ie, the height of the support protrusion 36, is defined as a height H.

FIG. 7 is another enlarged longitudinal cross-sectional view of the pressing portion 4. As shown in FIG. FIG. 7 is a diagram corresponding to (C) of FIG. In the longitudinal section of the tube body 3 in the axial direction, the distance between the center of the tip of the pressing part 4 and the edge of the upper support surface 34 is defined as a distance D.

FIG. 8 is a diagram showing the relationship between the curvature R and the fully closed pressing force F, and FIG. 9 is a diagram showing the relationship between the curvature R and the strain E. "Fully closing pressing force" refers to the pressing force required to deform the tube body 3 by the pressing part 4 driven by the driving part 5 and bring the pinch valve 1 into the fully closed state. "Strain" This refers to the strain in the part of the tube 3 that is most deformed in the fully closed state, for example, the part of the tube 3 that is in contact with the tip of the pressing part 4. The strain E is the value obtained by dividing the change in length before and after deformation by the length before deformation.

As shown in FIG. 8, as the curvature R decreases, the fully closing pressing force F also decreases. On the other hand, as shown in FIG. 9, when the curvature R becomes smaller, the curvature of the tubular body 3 when the tubular body 3 is deformed also becomes smaller following the curvature R of the pressing portion 4. As a result, the strain E increases, and the durability of the tube 3 decreases.

Considering these, it is preferable that the curvature R is 1.1 to 4.2 times the wall thickness T (FIG. 6) of the tube body 3. For example, if the diameter of the tube 3 is 25 mm and the allowable strain of the rubber of the tube 3 is 0.5, the fully closing pressing force F must be less than 1,000 N in order to make the pinch valve 1 within the required dimensions. There is a need to. As a result, the curvature R is 4 to 15 mm.

FIG. 10 is a diagram showing the relationship between the taper angle A and the fully closed pressing force F, and FIG. 11 is a diagram showing the relationship between the taper angle A and the strain E. As shown in FIG. 10, as the taper angle A becomes smaller, the fully closing pressing force F also becomes smaller. On the other hand, as shown in FIG. 11, as the taper angle A becomes smaller, the strain E becomes larger. That is, when the taper angle A is small, the contact surface with the tubular body 3 becomes smaller. As a result, the force applied per unit area of the tube 3, that is, the pressure increases. Therefore, the strain E also increases, and the durability of the tube body 3 decreases.

Considering these, it is preferable that the taper angle A is 55 to 90 degrees. For example, if the diameter of the tube 3 is 25 mm and the allowable strain of the rubber of the tube 3 is 0.5, the fully closing pressing force F must be less than 1,000 N in order to make the pinch valve 1 within the required dimensions. There is a need to. As a result, the taper angle A becomes 55 to 90 degrees.

FIG. 12 is a diagram showing the relationship between the height H of the support protrusion 36 and the fully closing pressing force F. As the height H of the support protrusion 36 increases, the full-close pressing force F becomes smaller, but when the height H exceeds a predetermined value, the full-close pressing force F becomes approximately constant. Considering this, it is preferable that the height H is greater than 7% of the wall thickness T of the tube body 3 and smaller than 40% of the wall thickness T. For example, in order to make the pinch valve 1 within the required dimensions with the pipe body 3 having a diameter of 25 mm, the fully closing pressing force F needs to be smaller than 1,000N. As a result, the height H is greater than 0.25 mm and is 1.5 mm.

Furthermore, although not shown, it is preferable that the distance D shown in FIG. 7 be 3 to 6 times the wall thickness T of the tubular body 3. The smaller the expansion of the tubular body 3 during pressurization, the smaller the strain E, that is, the load on the tubular body 3. The smaller the distance D, the smaller the expansion of the tubular body 3 and the smaller the strain E. However, when the diameter of the tubular body 3 is large, the stroke of the pressing portion 4 as the piston 11 moves up and down becomes large, and as a result, the required distance D becomes large. Even when the distance D is large, the wall thickness T must be increased in order to suppress the strain E to a specified value. When the wall thickness T is increased, the fully closed pressing force F is increased, so it is necessary to increase the size of the drive section 5. Therefore, in consideration of these balances, the distance D is preferably 3 to 6 times the wall thickness T of the tube body 3.

Considering these, it is preferable that the distance D is within the above range. The tube body 3 having a diameter of 25 mm has a wall thickness T of 3.5 mm, and as a design example, a distance D of 17.5 mm. In this case, the distance D is five times the wall thickness T. Further, the tube body 3 having a diameter of 40 mm has a wall thickness T of 6 mm, and as a design example, a distance D of 25.0 mm. In this case, the distance D is 4.2 times the wall thickness T.

As described above, by optimizing the shapes of the pressing portion 4 and the support member, the pressing force required to close the channel of the tube can be reduced without impairing the durability of the tube. Note that the optimum values of the curvature R, the taper angle A, the height H of the support protrusion 36, and the distance D may be designed in any combination.

FIG. 13 is a longitudinal sectional view of a pinch valve 100 according to a second embodiment of the present invention, and FIG. 14 is an exploded perspective view of the pinch valve 100. The pinch valve 100 according to the second embodiment differs from the pinch valve 1 according to the first embodiment only in the configuration of the valve part, but the effects are the same. Therefore, only the different points will be explained below. Note that the shapes of the base plates also differ from each other, and the shapes of the base plates differ depending on the shape of the valve portion.

As described above, the valve part 2 of the pinch valve 1 according to the first embodiment includes the cylindrical main body member 20, the holding member 21 that holds the pipe body 3 and is housed in the main body member 20, and the main body member 20. It has connection members 22 arranged at both ends, and cap nuts 23 that are screwed together with the connection members 22 at both ends of the main body member 20.

On the other hand, the valve part 102 of the pinch valve 100 according to the second embodiment includes a cylindrical main body member 120, connecting members 122 disposed at both ends of the main body member 120, and screwed together with the connecting members 122 at both ends of the main body member 120. It has a cap nut 123. That is, the valve part 102 of the second embodiment does not have a configuration equivalent to the holding member 21 in the valve part 2 of the first embodiment, and the main body member 120 directly holds the tube body 3. . In other words, the main body member 120 of the second embodiment has a shape in which the main body member 20 and the holding member 21 of the first embodiment are integrated. Therefore, the pinch valve 100 of the second embodiment also does not have the O-ring 29 disposed between the main body member 20 and the holding member 21 in the first embodiment. Note that it can also be said that the holding member, not the main body member 120, is configured in a shape in which the main body member 20 and the holding member 21 of the first embodiment are integrated.

FIG. 15 is a partially enlarged longitudinal sectional view of FIG. 13. An annular recess 131 for receiving the flange portion 6 of the tube body 3 is formed in the end surface of the main body member 120. An annular contact surface 132 that comes into contact with the inner annular end surface 8 of the flange portion 6 of the tube body 3 is formed on a surface corresponding to the bottom surface of the recess 131 . An annular projection 133 is formed on the contact surface 132 . The main body member 120 holds the tubular body 3 in a state where the tubular body 3 is slightly expanded in the axial direction. Therefore, each of the flange portions 6 of the tube body 3 is pressed against the contact surface 132 of the corresponding body member 120, and the annular projection 133 is buried in the end surface 8 of the flange portion 6 of the tube body 3. As a result, the annular projection 133 seals between the end surface 8 of the flange portion 6 and the contact surface 132 of the main body member 120.

The pinch valve 100 according to the second embodiment has, in addition to a primary seal for ensuring airtightness during normal use, a seal portion that is a secondary seal in case the tube body 3 ruptures. Thereby, even if the tube body 3 ruptures, the fluid inside the tube body 3 will not flow out to the outside of the pinch valve 100 . Specifically, the pinch valve 100 includes, as a seal portion, an annular projection 133 that is a first seal member, an O-ring 25 that is a second seal member, and an O-ring 17 that is a fourth seal member. , these seal fluid communication between the space near the outer surface of tube 3 and the outside of pinch valve 100 . Note that, as described above, the pinch valve 100 according to the second embodiment does not have a configuration corresponding to the O-ring 29, which is the third sealing member of the first embodiment. The annular projection 133 may be replaced with an O-ring.

In this regard, referring to FIG. 15, the annular projection 133 seals between the end surface 8 of the flange portion 6 and the contact surface 132 of the main body member 120, thereby preventing leakage in the L1 direction. Furthermore, the O-ring 25 seals between the valve portion 2 and the drive portion 5, thereby preventing leakage in the L2 direction. Furthermore, the O-ring 17 seals between the piston 11 and the base plate 112 to prevent leakage in the L4 direction.

Although the pinch valve 1 according to the first embodiment has more parts than the pinch valve 100 according to the second embodiment, it can be assembled easily. Furthermore, during maintenance, only consumable parts such as the tube body and O-ring need to be replaced, resulting in excellent maintenance costs. On the other hand, the pinch valve 100 according to the second embodiment has a structure in which the main body member 20 and the holding member 21 are integrated, and does not have the O-ring 29, compared to the pinch valve 1 according to the first embodiment. Therefore, the number of parts is small and it can be manufactured at a lower cost. Furthermore, maintenance can be easily performed by replacing the entire main body member assembled with the tube and O-ring.

1 Pinch valve 2 Valve part 3 Pipe body 4 Pressing part 5 Drive part 10 Cylinder 11 Piston 12 Base plate 13 Display 14 Cap 20 Main body member 21 Holding member 22 Connection member 23 Cap nut 25 O-ring 26 Annular member 27 Upper support member 28 Lower Support member 29 O-ring 31 Recess 32 Contact surface 33 Annular projection 34 Upper support surface 35 Lower support surface 36 Support projection A Taper angle D Distance H Height R Curvature T Thickness

Claims (7)

a valve part;
a pipe body having a flow path formed therein and housed in the valve portion;
a pressing unit that deforms the tubular body by pressing or releasing pressure on the tubular body, and opens and closes the flow path;
A pinch valve comprising a drive unit that drives the pressing unit,
further comprising a seal portion that seals fluid communication between a space near the outer surface of the pipe body and the outside of the pinch valve ,
The seal part has a first seal member, the valve part has a contact surface that comes into contact with an end surface of the tube, and the first seal is provided between the end surface of the tube and the contact surface. A sealing member is provided,
the first sealing member is an annular protrusion formed on the contact surface;
The pinch valve is characterized in that flange portions are formed at both ends of the pipe body, the inner side of the flange portion has a flat and annular end surface, and the first seal member is buried in the annular end surface. . The pinch valve according to claim 1 , wherein the seal portion has a second seal member, and the second seal member is provided between the valve portion and the drive portion. The seal portion includes a third seal member, the valve portion includes a main body member, and a holding member that holds the tube and is housed in the main body member, and the main body member and the holding member 3. The pinch valve according to claim 1, wherein the third seal member is provided between the pinch valve and the third seal member. The valve portion includes a main body member that holds the tube, a connecting member disposed at both ends of the main body member, and a cap nut that is screwed together with the connecting member at both ends of the main body member. The pinch valve according to any one of claims 1 to 3, characterized in that: The seal part has a fourth seal member, the drive part has a piston and a base plate, and the fourth seal member is provided between the piston and the base plate. The pinch valve according to any one of claims 1 to 4 . The pinch valve according to any one of claims 1 to 5 , wherein the sealing member is an O-ring. 7. The pinch valve according to claim 1, wherein the material of the valve part is plastic.

Images