Processing method of elastic check valve and elastic check valve

Abstract

To certainly provide a slit on a valve body of a rubber check valve by a safe and easy method.SOLUTION: A machining method of a rubber check valve 1 forms a slit on a valve body 3 of the rubber check valve 1 that has a cylindrical check valve body 2, and the valve body 3 that has a slit, is provided in a passage of the check valve body 2, and allows the passing of a fluid in one direction in the slit and does not allow the fluid in the opposite direction. So as to break fragile portion 5 formed on the valve body 3 in advance, air is made to circulate in one direction to break the fragile portion 5, thereby forming a slit.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an elastic check valve having a cylindrical check valve body and a valve body having a slit and disposed in a passage of the check valve body, which allows fluid to pass in one direction at the slit but does not allow fluid to pass in the reverse direction, and to an elastic check valve. [Background technology]

[0002] Conventionally, there has been known a sealed container that stores an object in a sealed state. For example, the sealed container has an intake valve and an exhaust valve provided on the bottom surface thereof, and an inert gas or the like is supplied into the container through the intake valve and exhausted through the exhaust valve as needed to replace the gas inside the container and maintain an airtight state.

[0003] A known example of such a check valve is the elastic check valve described above, which includes a cylindrical check valve body and a valve element having a slit disposed in a passage of the check valve body, which allows fluid to pass through the slit in one direction but not in the reverse direction. This valve element is made of soft rubber, and the slit is cut out manually using a special punching tool or the like.

[0004] For example, as disclosed in Patent Document 1, a method is known in which a melt-extruded resin is placed on the surface of a rotating cooling roll and cooled by blowing air onto it from an air knife device.

[0005] Also known is a method, as disclosed in Patent Document 2, in which cooling air is blown from an air knife nozzle onto the surface layer side of an uncured thermoplastic resin to forcibly cool it, and then a foam layer is laminated onto the base layer side. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-6271 [Patent Document 2] Patent No. 3357182 Summary of the Invention [Problem to be solved by the invention]

[0007] However, conventional manual work using dedicated tools requires a lot of work, such as preparing a dedicated punching tool, setting the elastomer check valve on the tool, punching it out, and then removing the punched elastomer check valve from the tool.In addition, because cutting with a blade is done manually, there are safety issues and it is extremely time-consuming.

[0008] The methods of Patent Documents 1 and 2 above use an air knife, and although it is possible to hold down an object onto which air is blown, it is not intended to perform cutting such as slitting.

[0009] The present invention has been made in view of the above points, and an object of the present invention is to provide a method for reliably providing a slit in the valve element of an elastic check valve in a safe and easy manner. [Means for solving the problem]

[0010] In order to achieve the above object, in this invention, a weakened portion provided in advance on a rubber valve body is broken by air pressure.

[0011] Specifically, in the first invention, A cylindrical check valve body; A method for manufacturing an elastic check valve having a valve body with a slit, the valve body having a slit and being integral with a passage of the check valve body, the valve body allowing fluid to pass through the slit in one direction but not in the reverse direction, comprising the steps of: The slit is formed by circulating air in the one direction so that a weakened portion formed in advance on the valve body breaks, thereby breaking the weakened portion.

[0012] According to the above configuration, when molding the elastic check valve, a fragile portion that is more likely to break than other portions is formed in the valve body in advance, and by simply circulating air at an appropriate pressure in the direction that the fluid is allowed to pass through, the fragile portion can be broken, and a slit can be formed safely and reliably.

[0013] In the second invention, in the first invention, the fragile portion is a portion that is thinner than other portions of the valve body, The thickness of the weakened portion is 0.02 mm or more and 0.06 mm or less.

[0014] Here, it is difficult to form the fragile portion thinner than 0.02 mm, and it is difficult to break it with air if it is thicker than 0.06 mm. However, with the above configuration, the fragile portion has an appropriate thickness, making it easy to form and reliably breaks with the pressure of ordinary compressed air, making it easy to manufacture the elastomer check valve.

[0015] In a third aspect of the present invention, in the first or second aspect of the present invention, The valve body is made of rubber, The hardness of the rubber is 20 or more and 90 or less in terms of durometer type A of JIS K6253.

[0016] If the Shore A hardness of the valve body is lower than 20, it is too soft, and if it is higher than 90, it is too hard and does not function properly as a check valve. However, with the above configuration, the hardness is appropriate, so an elastic check valve is obtained that is easy to break and can properly function as a check valve after breaking.

[0017] In a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, The configuration is such that a discharge portion that discharges compressed air from a compressor is pressed against one end side of the check valve body, and the compressed air is sent in to break the fragile portion.

[0018] According to the above-mentioned configuration, the slit can be formed extremely easily and safely.

[0019] In the fifth invention, in the fourth invention, The air pressure that breaks the fragile portion is set to 0.1 MPa or more and 2.0 MPa or less.

[0020] According to the above configuration, the pressure of a general compressor installed in a factory, etc. can be used without installing any more pressurizing equipment than necessary, and there is no risk of the pressure being too high and causing the valve body to break at parts other than the slit.

[0021] In the sixth invention, A cylindrical check valve body; an elastic check valve having a valve body having a slit and integrally provided in a passage of the check valve body, the valve body allowing fluid to pass in one direction through the slit but not in the reverse direction, The valve body is configured such that the gap between the valve body and the slit becomes gradually narrower as the valve body approaches the slit in the one direction, and a fractured surface is formed at the narrowest portion of the slit.

[0022] With the above-described configuration, a weak portion that is more easily broken than other portions is formed in advance in the portion of the valve body that will become the slit, as the gap between the portions gradually narrows, and the weak portion can be broken to safely and reliably form the slit simply by passing air of an appropriate pressure in the direction that the fluid is to pass through. This results in an elastic check valve that is inexpensive and easy to manufacture.

[0023] In the seventh invention, in the sixth invention, It is made of a single piece of rubber molding. The hardness of the rubber is 20 or more and 90 or less in terms of durometer type A of JIS K6253.

[0024] If the Shore A hardness of the valve body is lower than 20, it is too soft, and if it is higher than 90, it is too hard and does not function properly as a check valve. However, with the above configuration, the hardness is appropriate, so an elastic check valve is obtained that is easily broken by air pressure and can properly function as a check valve after breaking. [Effects of the Invention]

[0025] As described above, according to the present invention, the weakened portion provided in advance in the valve body is ruptured by air, so that a slit can be reliably provided in the valve body of the elastic check valve in a safe and easy manner. [Brief explanation of the drawings]

[0026] [Figure 1A] FIG. 2 is a plan view showing a rubber check valve. [Figure 1B] FIG. 1B is a cross-sectional view taken along line IB-IB of FIG. 1A. [Figure 2] 1C is an enlarged cross-sectional view of part II in FIG. 1B. [Figure 3] FIG. 3 is a cross-sectional view corresponding to FIG. 2 according to a first modified example of the embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view corresponding to FIG. 2 according to a second modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0028] -Rubber check valve configuration- 1A and 1B show a rubber check valve 1 as an elastomer check valve according to an embodiment of the present invention. For example, this rubber check valve 1 is a check valve provided at the bottom of a sealed container (not shown) or the like to allow communication with the outside. Rubber check valve 1 as an elastomer check valve is made of, for example, a one-piece molded product of fluororubber, but is not particularly limited as long as it is an elastomer, and may be made of thermoplastic or thermosetting elastomer, or rubber such as silicone rubber or ethylene propylene rubber. Furthermore, it may also be partially made of metal.

[0029] The rubber check valve 1 according to this embodiment has a cylindrical check valve body 2 and a valve element 3 provided integrally at the center thereof.

[0030] The check valve main body 2 has an outer diameter for insertion into a through-hole of a sealed container, for example, but its shape is not particularly limited, and it may be a cylinder with a through-hole in the center, such as an elliptical cross section, a field track shape with a pair of straight lines, or a rectangular shape. As described above, a portion of the check valve main body 2 may be made of metal or plastic.

[0031] 1B, the valve element 3 is molded integrally with the inner periphery of the check valve main body 2, which forms the passageway, and the spacing gradually narrows toward the tip, with a slit 4 that is linear in plan view at the center of the tip. This slit 4 is configured to allow fluid to pass in one direction (the direction of the arrow shown in FIG. 1B) (slit 4 opens) and not pass fluid in the opposite direction (slit 4 closes), thereby functioning as a check valve.

[0032] As shown enlarged in Figure 2, the slit 4 is formed by a method described below in a weakened portion 5 formed in the center of a straight, flat band-shaped portion 6 at the tip of the valve body 3 in a plan view. The weakened portion 5 is thinner than other portions of the valve body 3 (e.g., t1 = approximately 0.5 mm), and the thickness t2 of the portion of the weakened portion 5 that becomes the slit 4 is 0.02 mm or more and 0.06 mm or less (0.02 ≦ t2 ≦ 0.06). The width W of the weakened portion 5 is, for example, 0.1 mm (W = 0.1). In the transverse cross-sectional view of the band-shaped portion 6 in Figure 2, the inclination angle α of the side surface of the groove that forms the weakened portion 5 is, for example, 67° (α = 67°).

[0033] Furthermore, the rubber hardness of the valve element 3 of the rubber check valve 1 after molding is 20 or more and 90 or less in terms of durometer type A (shore A) of JIS K6253.

[0034] -Processing method for rubber check valves- Next, a method for manufacturing the rubber check valve 1 according to this embodiment will be described.

[0035] Although a detailed explanation will be omitted, the rubber check valve 1 is molded, for example, from fluororubber using a dedicated mold by injection molding or compression molding. At this molding stage, as described above, the linear fragile portion 5 is formed in the band-like portion 6 at the tip of the valve body 3. Note that, for example, the check valve main body 2 and the valve body 3 may be molded in two colors using different rubber materials.

[0036] As shown in FIG. 1B, the discharge part 10 (the tip of the air gun) that discharges compressed air from the compressor is pressed against one end (lower end) of the check valve body 2, and compressed air is sent in, causing the air to flow in one direction that allows fluid flow so that the pre-formed fragile part 5 in the valve body 3 breaks, breaking the fragile part 5 and forming the slit 4. This eliminates the need for a special punching tool. Note that if air is sent in the opposite direction, the valve body 3 will deform and not break properly. Furthermore, the discharged fluid is not limited to air; other gases can also be used. The slit 4 is formed as if it had been torn by air pressure, and a fractured surface can be seen when viewed under magnification. The fractured surface closes when the valve body 3 closes, but air does not leak from the closed part.

[0037] In this case, the air pressure required to rupture the fragile portion 5 is set to 0.1 MPa or more and 2.0 MPa or less. This allows the pressure of a typical compressor installed in a factory, etc., to be used, eliminating the need for excessive pressurization equipment. Furthermore, by setting the upper limit at 2.0 MPa or less, there is no risk of the valve body 3 rupturing at a location other than the slit 4 due to excessive pressure.

[0038] In this way, when molding the rubber check valve 1, a fragile portion 5 that is more easily broken than other portions is formed in the valve body 3 in advance, and the fragile portion 5 can be broken and the slit 4 can be formed safely and reliably simply by passing air at an appropriate pressure in one direction to allow the fluid to pass through.

[0039] The reason why the thickness of the fragile portion 5 is set to 0.02 mm or more and 0.06 mm or less is that it is difficult to mold the fragile portion 5 thinner than 0.02 mm, and it is difficult to break it with air if it is thicker than 0.06 mm. Since the fragile portion 5 of this embodiment has such an appropriate thickness, it is easy to mold the fragile portion 5 and it is reliably broken by the pressure of ordinary compressed air, making it easy to manufacture the rubber check valve 1.

[0040] The reason why the hardness of the rubber of the valve body 3 is set to 20 or more and 90 or less in Shore A hardness is that if it is lower than 20 it is too soft, and if it is higher than 90 it is too hard and does not function well as a check valve. The valve body 3 of this embodiment has an appropriate hardness, so it can be easily broken, and a rubber check valve 1 can be obtained that can properly function as a check valve after breaking.

[0041] As described above, according to the present invention, the fragile portion 5 provided in advance in the valve body 3 is designed to be ruptured by air, so that the slit 4 can be reliably provided in the valve body 3 of the rubber check valve 1 in a safe and easy manner.

[0042] -Variation 1- Fig. 3 shows a first modification of the embodiment of the present invention, which differs from the above embodiment in that the configuration of the fragile portion 5' is different. In the following first and second modifications, the same parts as those in Figs. 1A to 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0043] In this modified example, in the cross-sectional view of the band-shaped portion 6, the width of the groove-shaped portion of the fragile portion 5' gradually narrows from the bottom, and the upper side has a constant width W, with a band-shaped thin plate formed at the top.

[0044] In this modification, the thickness t2 of the fragile portion 5 is also 0.02 mm or more and 0.06 mm or less (0.02≦t2≦0.06). The width W of the fragile portion 5 is also, for example, 0.1 mm (W=0.1). In the cross-sectional view of the band-shaped portion 6, the inclination angle α' of the side surface of the groove portion forming the fragile portion 5 is α'=90° in this modification.

[0045] It should be noted that this α' is, for example, 45° or more and 90° or less (45°≦α'≦90°), and α'=67° corresponds to the above embodiment.

[0046] In this case as well, the fragile portion 5' can be broken by forcibly sending air in the direction that allows the fluid to pass through the check valve, thereby forming the slit 4.

[0047] -Variation 2- FIG. 4 shows a second modification of the embodiment of the present invention, which differs from the above-described embodiment and the first modification in that the configuration of the fragile portion 5'' is different.

[0048] In this modified example, a groove is also formed on the upper side of the fragile portion 5'', and in the cross-sectional view of the upper and lower band-shaped portions 6, the width of the groove-shaped portion is constant, and the fragile portion 5'' is made of a thin band-shaped plate. In other words, the fragile portion 5'' does not have to be at the uppermost part of the valve body 3, and may be located in the middle part of the band-shaped portion 6 in the thickness direction.

[0049] In this modification, the thickness t2 of the fragile portion 5 is 0.02 mm or more and 0.06 mm or less (0.02≦t2≦0.06). The width W of the fragile portion 5 is also, for example, 0.1 mm (W= 0.1 In the cross section of the band-like portion 6, the inclination angle α'' of the side surface of the groove portion forming the weakened portion 5 is α=90° in this modification. This α should be between 45° and 90° (45°≦α''≦90°).

[0050] In this case as well, the fragile portion 5' can be broken by forcibly sending air in the direction that allows the fluid to pass through the check valve, thereby forming the slit 4.

[0051] (Other embodiments) The present invention may be configured as follows in relation to the above embodiment.

[0052] That is, in the above embodiment, the fragile portion is linear in plan view, but it may be, for example, cross-shaped or V-shaped. On the other hand, if the fragile portion is perforated, air may leak from the interlocking portion when the slit closes after breaking, which is undesirable.

[0053] In the above embodiment, the rubber check valve 1 is used in a sealed container, but it is not limited to this and may also be used in piping or the like.

[0054] It should be noted that the above-described embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses. [Explanation of symbols]

[0055] 1. Rubber check valve (elastic check valve) 2. Check valve body 3 Valve body 4 slits 5,5',5'' Weakened section 6. Belt 10 Discharge part

Claims

1. A cylindrical check valve body; a valve body that is integrally formed on the inner periphery of the check valve body, the slits being linear in plan view at the tip and gradually narrowing toward the tip, and that allows fluid to pass through the slits in one direction but not in the reverse direction; At the tip of the valve body, a weak portion of a straight thin band-shaped plate is formed in advance in the width direction center of the flat band-shaped portion along the longitudinal direction of the band-shaped portion, and the weak portion is broken by circulating air in the one direction so that the weak portion breaks, thereby forming the slit. A method for processing an elastic check valve.

2. the fragile portion is made of a thin band-like plate portion that is thinner than the flat band-like portion, The thickness of the belt-shaped thin plate portion of the fragile portion is 0.02 mm or more and 0.06 mm or less.

2. A method for manufacturing an elastic check valve according to claim 1.

3. The valve body is made of rubber, The hardness of the rubber is 20 or more and 90 or less in terms of durometer type A of JIS K6253.

3. A method for manufacturing an elastic check valve according to claim 1 or 2.

4. A discharge portion that discharges compressed air at a pressure of 0.1 MPa or more and 2.0 MPa or less is pressed against one end side of the check valve body, and the compressed air is sent in to break the fragile portion.

4. A method for manufacturing an elastic check valve according to claim 1.

5. The weakened portion is formed in the belt-shaped thin plate at a middle position in the thickness direction of the flat belt-shaped portion.

4. A method for manufacturing an elastic check valve according to claim 1.

6. A cylindrical check valve body; an elastic check valve having a valve body having a slit and integrally provided on the inner circumferential side of the check valve body which serves as a passage, the valve body allowing fluid to pass in one direction through the slit but not in the reverse direction, The valve body has a gradually narrower gap as it approaches the slit in the one direction, The slit is provided in a flat band-shaped portion that is straight in a plan view, At the narrowest part of the slit, a fracture surface of a weakened portion that is thinner than the flat strip portion is formed at the center in the width direction of the flat strip portion along the longitudinal direction of the strip portion. An elastic check valve characterized by:

7. It is made of a single piece of rubber molding. The hardness of the rubber is 20 or more and 90 or less in terms of durometer type A of JIS K6253.

7. The elastic check valve according to claim 6.

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