pinch valve

Abstract

A pinch valve (1) is provided with: a pipe body (3) composed of an elastic material, having a cylindrical pipe main body (31) and annular flange portions (32) provided at both ends of the pipe main body (31), the pipe body (3) having a flow path formed inside; and a holding member (20) integrally formed and capable of housing the pipe body (3); at least one flange portion (32) protrudes radially outward at the end portion of the pipe main body (31) via a bent portion (33); in the bent portion (33), a first curved surface portion (33a) is provided on the outside of the pipe body (3), and a second curved surface portion (33b) is provided on the inside of the pipe body (3); in a cross section passing through the center axis of the pipe body (3), the maximum radius of curvature (R1) of the first curved surface portion (33a) is formed to be smaller than the maximum radius of curvature (R2) of the second curved surface portion (33b).

Description

Technical Field

[0001] The present invention relates to valves, and more particularly to pinch valves. Background Art

[0002] A known pinch valve comprises a valve portion; a tubular body with a flow path formed therein and housed within the valve portion; a pressing portion that deforms the tubular body by pressing or releasing the pressing force, thereby opening and closing the flow path; and a driving portion that drives the pressing portion (see, for example, Patent Document 1). In the pinch valve of Patent Document 1, the tubular body is housed within a retaining member of the valve portion. Annular flanges are formed at each end of the tubular body. Typically, the tubular body is formed of an elastic material such as rubber.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-211081

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2016-061335 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In addition, in the case where the retaining member is composed of a split member formed by two halves, for example, the split members are combined in a manner that surrounds the tube body and the split members are connected with screws or the like to perform assembly. On the other hand, in the case where the retaining member is formed integrally, in order to accommodate the tube body in the retaining member, it is necessary to elastically deform the end of one side of the tube body and insert it into the retaining member. However, even if the end of the tube body is compressed radially inward to deform it, it is difficult to elastically deform it due to the flange portion formed at the end. Furthermore, if the deformation is forced, the tube body may be damaged and the sealing performance may be impaired. The same problem may also occur, for example, in the butterfly valve of Patent Document 2, when a valve seat ring corresponding to a tube body having a flange portion is mounted on a valve body corresponding to the retaining member.

[0009] An object of the present invention is to provide a valve capable of easily attaching a pipe body having a flange portion to a holding member.

[0010] Means used to solve problems

[0011] According to a technical solution of the present invention, a valve is provided, characterized in that it comprises: a tube body made of elastic material, the tube body having a cylindrical tube main body and annular flange portions arranged at both ends of the above-mentioned tube main body, the tube body forming a flow path inside; and a retaining component, which is formed integrally and can accommodate the above-mentioned tube body; at least one of the above-mentioned flange portions protrudes radially outward at the end of the above-mentioned tube main body via a bent portion; in the above-mentioned bent portion, a first curved portion is provided on the outside of the above-mentioned tube body, and a second curved portion is provided on the inside of the above-mentioned tube body; in a cross-section passing through the central axis of the above-mentioned tube body, the maximum curvature radius of the above-mentioned first curved portion is formed to be smaller than the maximum curvature radius of the above-mentioned second curved portion.

[0012] The thickness of the tube body may be greater than that of the flange portion. The radial thickness of the curved portion may continuously decrease from the tube body toward the flange portion. A pressing portion may also be provided that presses the tube body or releases the pressing force to deform the tube body, thereby opening and closing the flow path.

[0013] Effects of the Invention

[0014] According to the technical solution of the present invention, there is a common effect of providing a valve capable of easily attaching a pipe body including a flange portion to a holding member. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a longitudinal sectional view of the pinch valve according to the embodiment of the present invention.

[0016] Figure 2 It is an enlarged longitudinal cross-sectional view of the tube body.

[0017] Figure 3 It is a three-dimensional diagram of the tube body.

[0018] Figure 4 It is a three-dimensional diagram showing the assembly of the tube body and the pushing portion.

[0019] Figure 5 It is a cross-sectional view of the tube body.

[0020] Figure 6 It is a front view of the pushing part.

[0021] Figure 7 It is a cross-sectional view of the pushing portion.

[0022] Figure 8 It is a longitudinal cross-sectional view showing the opening and closing of the flow path of the tube. DETAILED DESCRIPTION

[0023] Below, with reference to the attached Figure 1 In the drawings, corresponding components are given the same reference numerals.

[0024] Figure 1 This is a longitudinal cross-sectional view of a pinch valve 1 according to an embodiment of the present invention. The pinch valve 1 comprises a valve portion 2, a tubular body 3 (tube) having a flow path formed therein and housed within the valve portion 2, a pressing portion 4 that opens and closes the flow path by pressing or releasing the pressure on the tubular body 3 to deform the tubular body 3, a driving portion 5 that drives the pressing portion 4, and a cylindrical rod member 6 attached to the distal end of the pressing portion 4.

[0025] The drive unit 5 includes a cylinder 10, a piston 11 that slides within the cylinder 10, a base plate 12 positioned opposite the piston 11, an indicator 13, and a cap 14. The drive unit 5 is a pneumatic actuator that raises and lowers the piston 11 and the pressing member 4 within the cylinder 10 by supplying compressed air into the cylinder 10 through an air port (not shown), or by exhausting air from the cylinder 10. The drive unit 5 can be an electric actuator, or the pressing member 4 can be raised and lowered manually by operating a handle or lever. The pressing member 4 is attached to the tip of the piston 11. As the piston 11 rises and falls, the indicator 13 mounted on the piston 11 appears and disappears relative to the cylinder 10. Therefore, by visually observing the appearance and disappearance of the indicator 13 through the cap 14, the position of the piston 11, and thus the position of the pressing member 4, and thus the open or closed state of the pinch valve 1, can be determined. To seal between components, the pinch valve 1 includes a plurality of O-rings (for example, the O-ring 15 ).

[0026] The valve portion 2 includes a cylindrical retaining member 20 integrally formed to accommodate the tubular body 3, connecting members 21 disposed at both ends of the retaining member 20, and cap nuts 22 screwed together with the connecting members 21 onto both ends of the retaining member 20. The drive unit 5 is mounted to the valve portion 2, specifically, the retaining member 20, using screws (not shown). The tubular body 3 includes a cylindrical main body 31 and an annular flange 32 disposed at both ends of the main body 31, with a flow path formed therein. The cap nuts 22 are screwed onto the retaining member 20 while the connecting member 21 is in close contact with the end faces of the flange 32 and the end faces of the retaining member 20.

[0027] The pinch valve 1, particularly the valve portion 2, can be formed entirely of a plastic material. For example, the cylinder 10 and base plate 12 are formed from polypropylene (PPG) mixed with glass, the pusher 4 and piston 11 are formed from acetal resin (POM), the retaining member 20, the connecting member 21, and the cap nut 22 are formed from polyvinyl chloride (U-PVC), the indicator 13 is formed from acrylonitrile butadiene styrene (ABS), and the cap 14 is formed from polycarbonate (PC). The tube 3 is made of an elastic material such as rubber, for example, ethylene propylene diene monomer (EPDM) or fluorocarbon rubber (FKM). The rod member 6 is made of metal or rigid plastic, and can also be made of the same material as the pusher 4.

[0028] Figure 2 It is an enlarged longitudinal cross-sectional view of the tube body 3. Specifically, Figure 2 (a) is Figure 1 The enlarged view of section A is shown. Figure 2 (b) is Figure 1 An enlarged view of part B is shown.

[0029] Reference Figure 2 In (a), in the tube body 3, at least one flange portion 32, in this embodiment, Figure 1 The flange portion 32 on the left side of the center is formed to protrude radially outward through a bent portion 33 at the end of the pipe body 31. An annular sealing protrusion 32a is provided on the end surface of the flange portion 32 facing outward relative to the axial direction, which contacts the connecting member 21 and performs a sealing effect.

[0030] In the curved portion 33, a first curved portion 33a is provided on the outside of the tube body 3, i.e., the outside of the flow path, and a second curved portion 33b is provided on the inside of the tube body 3, i.e., the inside of the flow path. Figure 2 In the longitudinal cross-sectional view shown, i.e., the cross-section passing through the central axis of the tube body 3, the curvature radius R1 of the first curved surface portion 33a is formed to be smaller than the curvature radius R2 of the second curved surface portion 33b. When the first curved surface portion 33a and the second curved surface portion 33b are composed of multiple curved surfaces having multiple curvature radii, the maximum curvature radii can be compared. In other words, the maximum curvature radius of the first curved surface portion 33a can also be formed to be smaller than the maximum curvature radius of the second curved surface portion 33b.

[0031] Near the bend 33, the thickness t1 of the tube body 31 may be greater than the thickness t2 of the flange 32. In this case, the radial thickness t of the bend 33 continuously decreases from the tube body 31 toward the flange 32. Thus, the radial thickness t of the bend 33 is smaller than the thickness t1 of the tube body 31 and greater than the thickness t2 of the flange 32. The radial thickness t of the bend 33 is defined as the thickness perpendicular to a tangent line at a predetermined position of the first curved surface portion 33a or the second curved surface portion 33b.

[0032] Reference Figure 2 In (b), the flange portion 32 on the other side is constructed so as to protrude radially outward through the corner portion 34 at the end of the tube body 31. In the corner portion 34, a curved portion 34a having a curvature radius R1 equivalent to the first curved portion 33a is provided on the outside of the tube body 3 in the same manner as the curved portion 33. On the other hand, a curved portion equivalent to the second curved portion 33b is not provided on the inside of the tube body 3. Strictly speaking, there is a portion having a small curvature radius on the inside of the tube body 3, but its curvature radius is very small compared to the curvature radius R1 of the curved portion 34a. In addition, the maximum thickness t3 of the curved portion 34a in the direction perpendicular to the tangent at a predetermined position is very large compared to the thickness t1 of the tube body 31 and the thickness t2 of the flange portion 32.

[0033] If Figure 2 The curved portion 33 shown in (a) is Figure 2 As can be seen from the shape and structure of the corner portion 34 shown in FIG. 3 (b), since the bend 33 has lower rigidity than the corner portion 34, the flange portion 32 is more easily flexed, for example, in the axial direction, with the bend 33 serving as a fulcrum. Consequently, one end of the tube body 3 provided with the bend 33 is more easily elastically deformed than the other end of the tube body 3 provided with the corner portion 34. Furthermore, by making the thickness t2 of the flange portion 32 smaller than the thickness t1 of the tube body 31 as described above, the flange portion 32 can be more easily elastically deformed.

[0034] When the retaining member 20 is integrally formed as in the pinch valve 1 of this embodiment, the tubular body 3 must be accommodated in the retaining member 20 by inserting it into the retaining member 20 while elastically deforming one end of the tubular body 3. Therefore, during assembly, the end of the tubular body 3 provided with the bent portion 33 is compressed radially inward to deform it, making it easier to insert the tubular body 3 into the retaining member 20. As a result, the tubular body 3 provided with the flange portion 32 can be easily attached to the retaining member 20. Furthermore, since the bent portion 33 is provided with the first curved surface portion 33a and the second curved surface portion 33b, stress during elastic deformation is dispersed, preventing damage to the bent portion 33 and the surrounding area due to stress concentration.

[0035] Furthermore, since the corner portions 34 are highly rigid, it is difficult to bend the flange portion 32, for example, in the axial direction, using the corner portions 34 as fulcrums. Consequently, it is difficult to elastically deform the end portion of the tube body 3 provided with the corner portions 34. Consequently, it is difficult to insert the tube body 3 into the retaining member 20 while elastically deforming the end portion of the tube body 3 provided with the corner portions 34. Even if deformation is attempted with difficulty, the tube body may be damaged, thereby impairing the sealing performance.

[0036] Therefore, in a configuration where assembly is possible with either end of the tube body 3 inserted into the retaining member 20, a curved portion 33 can be provided on both flange portions 32 of the tube body 3. This eliminates the need for end verification during assembly, enabling quick and reliable assembly. Furthermore, by providing the curved portion 33 only on one end of the tube body 3, as in the aforementioned embodiment, the mold for manufacturing the tube body 3 can be manufactured more cheaply than if the curved portions 33 were provided on both ends of the tube body 3. Specifically, the core on the flow path side of the tube body 3 is composed of two core halves, separated by a plane perpendicular to the central axis in the center of the flow path. In this case, since the surface of the second curved portion 33b, the surface of the tube body 31, and the surface of the flange portion 32 are continuous, while functionally acceptable, the presence of an insert parting line would make it noticeable. To enhance the appearance, the core half on the side where the curved portion 33 is provided is integrally formed from a larger mold material. On the other hand, since the corner 34 is a substantially right angle, it is less noticeable if a nesting line is provided to match its tip. Therefore, the core half on the side without the curved portion 33 can be split and manufactured so that the nesting line is located at the portion corresponding to the corner 34. Consequently, the core half on the side without the curved portion 33 can be manufactured more cheaply than the core half on the side with the curved portion 33. The structure of the tubular body 3 having the curved portion 33 provided on the flange 32 as described above can also be applied to valves having the same structure other than pinch valves, such as butterfly valves and other valves.

[0037] Figure 3 is a three-dimensional diagram of the tube body 3, Figure 4 This is a perspective view showing the assembly of the tubular body 3 and the pressing portion 4. The tubular body 3 further includes a connecting portion 35, which is provided on the outer surface of the tubular body 3, that is, on the outer surface of the tubular main body 31, and connects the rod member 6 to the tubular body 3 in a transverse arrangement relative to the tubular body 3. In other words, the connecting portion 35 is provided with a through-hole 36, which allows the rod member 6 to be inserted and extends transversely relative to the tubular body 3. The connecting portion 35 is formed as a whole into a cylindrical shape, but any other shape is acceptable as long as the through-hole 36 is provided. The connecting portion 35 is integrally provided with the tubular main body 31.

[0038] To assemble the tube body 3 and the pressing portion 4 into the valve portion 2, the tube body 3 is elastically deformed and housed in the holding member 20 as described above. Next, the rod member 6 is inserted into the through hole 36 of the connecting portion 35. The rod member 6 is then attached to the front end of the pressing portion 4, completing the assembly of the tube body 3 and the pressing portion 4.

[0039] Figure 5This is a cross-sectional view of the tube body 3. The inner surface of the through-hole 36 of the connecting portion 35 is formed into a substantially cylindrical shape corresponding to the cylindrical rod member 6. A flat surface 37 extending along the entire length of the through-hole 36 is provided on the inner surface of the through-hole 36 on the tube body 31 side. The provision of the flat surface 37 eliminates the step between the entrance 36a of the through-hole 36 and the outer surface of the tube body 31. As a result, the rod member 6 can be smoothly inserted into the through-hole 36 during assembly.

[0040] Figure 6 is a front view of the pushing portion 4, Figure 7 This is a cross-sectional view of the pressing portion 4. A fitting recess 41 is provided at the front end of the pressing portion 4, into which the rod member 6 can be snap-fitted. The fitting recess 41 is composed of a first recess 42 and a second recess 43. The first recess 42 is formed to complementarily receive the connecting portion 35, and the second recess 43 extends coaxially across the first recess 42 and is formed to complementarily receive the rod member 6. A pair of engaging claws 44 are provided only at the ends of the second recess 43, which can engage with the rod member 6.

[0041] A pair of engaging claws 44 are arranged oppositely (relatively) along the edge of the second recess 43. The spacing between the pair of engaging claws 44 is smaller than the diameter of the cylindrical rod member 6. On the other hand, in the second recess 43, the spacing between the edge of the portion where the engaging claws 44 are not provided is larger than the diameter of the cylindrical rod member 6. During assembly, if the pushing portion 4 is pushed relative to the cylindrical rod member 6, the rod member 6 elastically deforms the pair of engaging claws 44 in the second recess 43 to separate the pair of engaging claws 44, enabling the rod member 6 to be snap-fitted. As a result, the pushing portion 4, the rod member 6, and the tubular body 3 connected to the rod member 6 can be simply and firmly connected as a whole.

[0042] Figure 8 It is a longitudinal cross-sectional view showing the opening and closing of the flow path of the tube body 3. Figure 8 (a) shows the fully open state of the pinch valve 1. Figure 8 (b) shows the fully closed state of the pinch valve 1. Figure 8 , components of the pinch valve 1 other than the tube body 3, the pressing portion 4, and the rod member 6 are omitted. The pinch valve 1 is configured such that the tube body 3 is deformed by pressing or releasing the tube body 3 via the pressing portion 4 of the rod member 6, thereby opening and closing the flow path.

[0043] Because the pressing portion 4 is connected to the tubular body 3 via the rod member 6, when the pressing portion 4 presses the tubular body 3, the entire length of the rod member 6 pushes the tubular body 3. At this time, no load acts on the connecting portion 35. On the other hand, when the pressing portion 4 releases the pressure on the tubular body 3, for example, by raising the piston 11, the pressing portion 4 rises, and the rod member 6, engaged with the pressing portion 4, pulls the tubular body 31 upward via the connecting portion 35. As a result, the pinch valve 1 can be reliably fully opened. In other words, the shape, placement, and dimensions of the engaging claw 44 are appropriately designed to ensure sufficient engagement force to prevent the rod member 6 from disengaging when the tubular body 31 is pulled upward to fully open the pinch valve 1. The design of the engaging claw 44 should also take into account the operating conditions of the pinch valve 1, the fluid pressure, and the material of the tubular body 3.

[0044] Therefore, even if the elastic material (e.g., rubber) constituting the tube body 3 degrades due to aging, resulting in a decrease in the elastic restoring force of the tube body 3, plastic deformation of the tube body 3, or adhesion between the inner surfaces of the tube body 3 that contact each other when fully closed, the pinch valve 1 can still be reliably and accurately controlled for opening and closing. Furthermore, no load acts on the connecting portion 35 when the pressing portion 4 presses the tube body 3. Instead, a load in the tensile direction, which occurs when the pressing portion 4 releases the pressure and pulls the tube body 31 upward, acts. Thus, deterioration or damage to the connecting portion 35 can be minimized. Furthermore, while the pinch valve 1 has a structure that adds a rod member 6 and a connecting portion 35 compared to the pinch valve described in Patent Document 1, reliable opening and closing is achieved with minimal change in overall size.

[0045] The rod member 6 is preferably made to have a length that is approximately the same as the width of the deformed tube body 3 in the fully closed state. If the rod member 6 is shorter than the width of the deformed tube body 3 in the fully closed state, the edges of the rod member 6 at both ends may contact the surface of the tube body 31 and damage the tube body 3. On the other hand, if the rod member 6 is longer than the width of the deformed tube body 3 in the fully closed state, it may interfere with the inner surface of the retaining member 20 or other components. In addition, from the perspective of preventing the rod member 6 from damaging the tube body 3 in the event of contact with the tube body 31, it is preferable to chamfer the edges of the ends of the rod member 6.

[0046] The structure having the connecting portion 35 that connects the rod member 6 to the tubular body 3 in a transverse arrangement is applicable not only to a pinch valve having an integrally formed retaining member 20 but also to a retaining member composed of, for example, two separate halves. The rod member 6 may also be shaped like a polygonal column rather than a cylindrical column. Besides fitting, the rod member 6 may also be attached to the distal end of the pressing portion 4 by means of fastening or tightening.

[0047] Description of labels

[0048] 1. Pinch valve; 2. Valve portion; 3. Tube body; 4. Pushing portion; 5. Driving portion; 6. Rod member; 10. Cylinder; 11. Piston; 12. Base plate; 13. Indicator; 14. Cap; 15. O-ring; 20. Holding member; 21. Connecting member; 22. Cap nut; 31. Tube body; 32. Flange portion; 33. Bend portion; 33a. First curved portion; 33b. Second curved portion; 34. Corner portion; 35. Connecting portion; 36. Through hole; 41. Fitting recess; 42. First recess; 43. Second recess; 44. Engaging claw.

Claims

1. A valve, characterized in that: have: a tube body made of an elastic material, comprising a cylindrical tube body and annular flange portions provided at both ends of the tube body, wherein a flow path is formed inside the tube body; and The holding member is formed integrally and is capable of accommodating the tube body. One of the flange portions protrudes radially outward at the end of the pipe body via a bent portion, and the other flange portion protrudes radially outward at the end of the pipe body via a corner portion. In the above-mentioned bending portion, a first curved portion is provided on the outside of the above-mentioned tube body, and a second curved portion is provided on the inside of the above-mentioned tube body. In a cross section passing through the central axis of the tube, the maximum curvature radius of the first curved portion is formed to be smaller than the maximum curvature radius of the second curved portion. At the corner, only the curved portion is provided on the outer side of the tube. The thickness of the pipe body is greater than the thickness of the flange portion.

2. The valve according to claim 1, wherein The thickness of the bent portion in the radial direction continuously decreases from the pipe body side toward the flange portion side.

3. The valve according to claim 1 or 2, characterized in that The invention further comprises a pressing portion for pressing or releasing the pressing of the tube body to deform the tube body and open or close the flow path.

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