Pipe joint and manufacturing method of the same

Abstract

To provide a pipe joint which makes screw fitting between a joint body and a cap more difficult to be disassembled.SOLUTION: A pipe joint 1 includes: a joint body 10 in which a female screw part 11cA is formed on an inner peripheral surface; a cap 15A in which a male screw part 16aA configured to fit with the female screw part is formed on an outer peripheral surface; and an adhesion part 25A where the female screw part and the male screw part are adhered to each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pipe joint and a method for manufacturing a pipe joint. [Background technology]

[0002] 2. Description of the Related Art Conventionally, pipe joints have been used to connect pipes used for water supply, hot water supply, air conditioning equipment, and the like in buildings (see, for example, Patent Documents 1 and 2). In the pipe joint of Patent Document 1, the joint body and the cap are both made of metal. The joint body and the cap are connected by threaded engagement. In the pipe joint of Patent Document 2, the joint body and the cap are both made of resin. The joint body and the cap are connected by threaded engagement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-015021 [Patent Document 2] Patent Publication No. 2021-028516 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the pipe joint of Patent Document 1, a gap is formed between the threads of the joint body and the cap, so there is a risk that the joint body and the cap may be easily disassembled with a tool such as a pipe wrench.

[0005] The present invention has been made in consideration of such problems, and has an object to provide a pipe joint in which the threaded engagement between the joint body and the cap is difficult to disassemble, and a method for manufacturing the pipe joint. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention proposes the following means. (1) A first aspect of the present invention is a pipe fitting comprising a fitting body having a female threaded portion formed on an inner circumferential surface, a cap having a male threaded portion formed on an outer circumferential surface thereof that fits with the female threaded portion, and an adhesive portion that bonds the female threaded portion and the male threaded portion to each other. In this invention, the female threaded portion of the joint body and the male threaded portion of the cap are threadedly fitted together by an adhesive portion, thereby making it difficult to disassemble the threaded fitting between the joint body and the cap.

[0007] (2) A second aspect of the present invention may be the pipe joint according to (1), wherein the adhesive portion is formed from an epoxy resin, a silicone resin, or an acrylic resin. In the present invention, the adhesive portion can be made of a known material such as an epoxy resin, a silicone resin, or an acrylic resin.

[0008] (3) A third aspect of the present invention may be the pipe joint according to (1) or (2), further comprising an annular packing disposed on the inner circumferential surface of the joint body. (4) A fourth aspect of the present invention may be the pipe fitting described in (3), further comprising an annular base member, an annular first stopper, an annular spacer, and an annular second stopper, wherein the first stopper, the spacer, the second stopper, the base member, and the packing are arranged in this order on the inner circumferential surface of the fitting body in the axial direction of the fitting body.

[0009] (5) A fifth aspect of the present invention is a method for manufacturing a pipe fitting according to any one of (1) to (4), comprising the steps of applying an adhesive to the male threaded portion and then fitting the cap to the fitting body. In this invention, an adhesive is applied to the male threaded portion, and then the cap and the joint body are fitted together, and the adhesive is used as an adhesive portion, for example. This makes it difficult to disassemble the threaded fitting between the joint body and the cap. Effect of the Invention

[0010] In the pipe joint and the method for manufacturing the pipe joint of the present invention, the threaded engagement between the joint body and the cap can be made difficult to disassemble. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional side view of a pipe joint according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view of a main part in FIG. [Diagram 3] FIG. 13 is a diagram showing the change in torque required to disassemble the cap depending on the adhesive specifications. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, one embodiment of a pipe joint and a method for manufacturing a pipe joint (hereinafter simply referred to as a manufacturing method) according to the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 and 2, the pipe joint 1 of this embodiment includes a joint body 10, caps 15A, 15B, packings (sealing members) 20A, 20B, adhesive portions 25A, 25B, base members 30A, 30B, first stoppers 35A, 35B, spacers 40A, 40B, and second stoppers 45A, 45B. In FIG. 1, pipes 100A, 100B are indicated by two-dot chain lines.

[0013] 2, the packing 20A and the base member 30A form a water stopping portion 50A. The first stopper 35A, the spacer 40A, and the second stopper 45A form a fixing portion 51A. As shown in Figures 1 and 2, the joint body 10 and the caps 15A and 15B are formed in a cylindrical shape. The joint body 10 and the caps 15A and 15B are arranged coaxially with a common axis. Hereinafter, the common axis will be referred to as the axis O1. The axis O1 is the axis of the joint body 10. A direction perpendicular to the axis O1 is called a radial direction, and a direction going around the axis O1 is called a circumferential direction.

[0014] As shown in FIG. 1, the pipe joint 1 is formed symmetrically with respect to a reference plane S1 perpendicular to an axis O1. In the following, the configuration of the first side D1 in the direction of the axis O1 with respect to the reference plane S1 (hereinafter simply referred to as the first side D1) is indicated by adding the capital letter "A" to the number or number and lowercase English letter of the symbol. The configuration of the second side D2 (hereinafter simply referred to as the second side D2) on the opposite side of the first side D1 in the direction of the axis O1 with respect to the reference plane S1 is indicated by adding the capital letter "B" to the number or number and lowercase English letter of the symbol of the configuration of the first side D1. This avoids redundant explanations. For example, the caps 15A and 15B are configured to be plane-symmetrical with respect to the reference plane S1. In the configuration of the first side D1 of the pipe joint 1 with respect to the reference plane S1, the first side D1 is the outer side in the direction of the axis O1, and the second side D2 is the inner side in the direction of the axis O1.

[0015] As shown in FIGS. 1 and 2, the joint body 10 has a cylindrical body 11 and a protruding portion 12. The cylindrical body 11 is formed in a cylindrical shape. On the inner peripheral surface of the cylindrical body 11, a first enlarged diameter portion 11aA, a second enlarged diameter portion 11bA, and a female thread portion 11cA are formed. As shown in Fig. 2, the first enlarged diameter portion 11aA, the second enlarged diameter portion 11bA, and the female thread portion 11cA are arranged in this order from the reference plane S1 toward the first side D1. The first enlarged diameter portion 11aA, the second enlarged diameter portion 11bA, and the female thread portion 11cA are arranged coaxially with the axis O1. The first enlarged diameter portion 11aA, the second enlarged diameter portion 11bA, and the female thread portion 11cA are formed over the entire circumference around the axis O1.

[0016] The inner diameter of the first expanded diameter portion 11aA is larger than the inner diameter of a portion of the cylindrical body 11 that is closer to the second side D2 than the first expanded diameter portion 11aA. A first step portion 11dA is formed between the first expanded diameter portion 11aA and a portion of the cylindrical body 11 that is closer to the second side D2 than the first expanded diameter portion 11aA. The first step portion 11dA is a surface facing the first side D1.

[0017] The inner diameter of the second expanded diameter portion 11bA is larger than the inner diameter of the first expanded diameter portion 11aA. A second step portion 11eA is formed between the second expanded diameter portion 11bA and the first expanded diameter portion 11aA. The second step portion 11eA is a surface facing the first side D1. The female thread portion 11cA is formed on the first side D1 of the second enlarged diameter portion 11bA.

[0018] 1, the protruding portion 12 is formed in an annular shape and is disposed on a reference plane S1. The protruding portion 12 protrudes from the inner circumferential surface of the cylindrical body 11 toward the inside in the radial direction. The cylindrical body 11 and the protruding portion 12 of the joint body 10 are made of metal. The metal forming the joint body 10 can be arbitrarily selected based on the quality design according to the application, from bronze, brass, stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc. The joint body 10 is preferably formed of bronze.

[0019] The joint body 10 may be made of resin (synthetic resin). Examples of resins that form the joint body 10 include cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polypropylene resin (PP), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF) fluororesin, polytetrafluoroethylene (PVFE) fluororesin, and the like.

[0020] As shown in FIG. 2, the cap 15A has a cylindrical body 16A and a flange 17A. The cylindrical body 16A is formed in a cylindrical shape. A male screw portion 16aA is formed in the middle portion in the axis O1 direction on the outer circumferential surface of the cylindrical body 16A. The flange 17A is formed in an annular shape and protrudes radially outward from an end of the first side D1 on the outer circumferential surface of the cylindrical body 16A. The cylindrical body 16A and the flange 17A of the cap 15A are made of resin. The cap 15A can be made of the same resin as the joint body 10. The cap 15A is preferably made of polyphenylene sulfide resin. By forming the cap 15A from resin, the manufacturing cost of the cap 15A can be reduced. The cap 15A may be made of a metal. The joint body 10 may be made of the same metal as the joint body 10 itself.

[0021] The cylindrical body 16A of the cap 15 is disposed within the end of the first side D1 of the cylindrical body 11 of the joint body 10. The male threaded portion 16aA of the cap 15 is fitted (fitted) into the female threaded portion 11cA of the joint body 10. A gap 105A is formed between the male threaded portion 16aA and the female threaded portion 11cA due to the threaded fit. The gap 105A is a small gap caused by a part of the male threaded portion 16aA and a part of the female threaded portion 11cA that are not in contact with each other. The flange 17A of the cap 15 contacts the cylindrical body 11 of the joint body 10 from the first side D1 of the cylindrical body 11. Here, the length (thread width) in the axis O1 direction along which the female thread portion 11cA and the male thread portion 16aA are formed is defined as L1.

[0022] The packing 20A is formed in an annular (ring-like) shape. For example, an O-ring is used as the packing 20A. The inner diameter of the packing 20A is smaller than the inner diameter of the first enlarged diameter portion 11aA of the cylindrical body 11 on the second side D2. The packing 20A is disposed in the first enlarged diameter portion 11aA of the cylindrical body 11. The packing 20A is disposed on the inner peripheral surface of the first enlarged diameter portion 11aA of the cylindrical body 11 (joint main body 10). The packing 20A contacts the first enlarged diameter portion 11aA of the cylindrical body 11 from the radially inner side of the first enlarged diameter portion 11aA, and contacts the first step portion 11dA from the first side D1 of the first step portion 11dA. The material that can be used to form the packing 20A is ethylene propylene diene rubber (EPDM), fluororubber (FKM), vinyl methyl silicone rubber (VMQ), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), chloroprene rubber (CR), or other rubber materials.

[0023] The adhesive portion 25A is disposed in a gap 105A between the female thread portion 11cA of the joint body 10 and the male thread portion 16aA of the cap 15A, which are fitted together. The adhesive portion 25A bonds the female thread portion 11cA and the male thread portion 16aA to each other. The adhesive portion 25A is formed of an epoxy resin, a silicone resin, or an acrylic resin. It is preferable that the adhesive portion 25A is arranged in a range of (L1×3 / 5) in the direction of the axis O1, excluding the range of (L1 / 5) at the end of the first side D1 and the range of (L1 / 5) at the end of the second side D2, of the thread width L1.

[0024] The base member 30A, the first stopper 35A, the spacer 40A, and the second stopper 45A are each formed in an annular (ring-shaped) shape. The packing 20A, the base member 30A, the first stopper 35A, the spacer 40A, and the second stopper 45A are disposed on the inner circumferential surfaces of the first enlarged diameter portion 11aA and the second enlarged diameter portion 11bA of the cylindrical body 11 (joint main body 10). The packing 20A, the base member 30A, the first stopper 35A, the spacer 40A, and the second stopper 45A are arranged in the following order toward the first side D1: packing 20A, base member 30A, first stopper 35A, spacer 40A, and second stopper 45A.

[0025] The base member 30A has a first base portion 31A and a second base portion 32A. The first base portion 31A and the second base portion 32A are each formed in a circular ring shape. A recess 32aA is formed in a corner of the second base portion 32A between the radially inner side and the first side D1. The recess 32aA is recessed in a direction between the radially outer side and the second side D2. The second base portion 32A is disposed on the first side D1 relative to the first base portion 31A. The second base portion 32A protrudes radially outward relative to the first base portion 31A. The second base portion 32A is continuous with the first base portion 31A. The first base portion 31A contacts the first expanded diameter portion 11aA of the cylindrical body 11 from the radially inner side of the first expanded diameter portion 11aA. The second base portion 32A contacts the second expanded diameter portion 11bA of the cylindrical body 11 from the radially inner side of the second expanded diameter portion 11bA, and contacts the second step portion 11eA from the first side D1 of the second step portion 11eA.

[0026] The first base portion 31A and the second base portion 32A of the base member 30A may contain a resin having high chemical resistance, such as polyphenylene sulfide resin (PPS). The base member 30A may also contain glass fiber reinforced polyphenylene sulfide resin (GFPPS).

[0027] The first stopper 35A has a first stopper portion 36A and a second stopper portion 37A. The first stopper portion 36A and the second stopper portion 37A are each formed in an annular shape. The first stopper portion 36A is disposed coaxially with the axis O1. The second stopper portion 37A protrudes radially inward from the inner peripheral edge of the first stopper portion 36A. The second stopper portion 37A is gradually inclined toward the second side D2 as it extends radially inward. The inner diameter of the second stopper portion 37A is smaller than the inner diameter of the first enlarged diameter portion 11aA of the cylindrical body 11 on the second side D2. The first stopper portion 36A and the second stopper portion 37A of the first stopper 35A can be made of the same metal as the joint body 10.

[0028] The spacer 40A is formed in an annular shape and is disposed coaxially with the axis O1. The spacer 40A and the base member 30A sandwich the first stopper 35A in the direction of the axis O1. The second stopper 45A has a first stopper portion 46A and a second stopper portion 47A that are configured similarly to the first stopper portion 36A and the second stopper portion 37A of the first stopper 35A. The second stopper 45A is disposed between the spacer 40A and the cylindrical body 16A of the cap 15A.

[0029] In the pipe fitting 1 configured as described above, an end portion of the second side D2 of the pipe 100A is disposed within the cap 15A. As shown in Fig. 1, the pipe 100A contacts the protruding portion 12 of the fitting body 10 from the first side D1 of the protruding portion 12. The watertight portion 50A prevents water passing through the inside of the pipe 100A from leaking out of the pipe joint 1. The fixing portion 51A fixes the pipe 100A to the pipe joint 1.

[0030] Next, a manufacturing method of this embodiment will be described. The manufacturing method includes a placement step and a fitting step. First, in an arrangement step, the packing 20A, the base member 30A, the first stopper 35A, the spacer 40A, and the second stopper 45A are arranged in a portion of the first side D1 of the cylindrical body 11 of the joint body 10. Similarly, the packing 20B, the base member 30B, the first stopper 35B, the spacer 40B, and the second stopper 45B are arranged in a portion of the second side D2 of the cylindrical body 11 of the joint body 10. Once the placement process is completed, the fitting process begins.

[0031] Next, in a fitting process, an adhesive (not shown) is applied to the male thread portion 16aA of the cap 15A, and then the cap 15A is fitted to the joint body 10. Similarly, an adhesive (not shown) is applied to the male thread portion of the cap 15B, and then the cap 15B is fitted to the joint body 10. The adhesive hardens, etc., to form adhesive portions 25A and 25B. When the fitting step is completed, all steps of the manufacturing method are completed, and the pipe fitting 1 is manufactured.

[0032] The pipe joint 1 to which the pipes 100A, 100B are connected is used by allowing water or the like to flow through the pipes 100A, 100B.

[0033] (Measurement results of the force required to disassemble the cap of a pipe joint) The adhesive used was a two-liquid epoxy adhesive manufactured by ThreeBond Holdings Co., Ltd. The base agent was TB2023 and the hardener was TB2105C. The measurement results are shown in Fig. 3. In Fig. 3, the horizontal axis represents the specifications of the adhesive (adhesive portion), and the vertical axis represents the torque required when disassembling the cap 15A (hereinafter referred to as disassembly torque).

[0034] The pipe joint of sample 1, which is a comparative example, does not have adhesive portions 25A and 25B. In this case, the disassembly torque was 0.3 N·m. Cap 15A can be disassembled by hand by an operator without using any tools. Pipe joints 1 of samples 2 to 4, which are examples, have adhesive parts 25A and 25B. The masses of adhesive parts 25A and 25B in pipe joints 1 of samples 2 to 4 (per one side; hereinafter, referred to as the amount of adhesive applied) are 0.04 g, 0.05 g, and 0.06 g, respectively. The disassembly torque of pipe fitting 1 in samples 2 to 4 was 4.0 N·m or more. Disassembly of cap 15A was impossible for an operator to do by hand and required tools.

[0035] As described above, the amount of adhesive to be applied is preferably 0.04 g or more and 0.06 g or less, and more preferably 0.05 g. When the amount of adhesive applied was less than 0.04 g, the cap 15A was easily disassembled, and the "disassembly" rating was "x." There was no overflow of the adhesive from the cap 15A, and the "overflow of adhesive" rating was "o." When the amount of adhesive applied was 0.04 g or more and 0.06 g or less, the cap 15A was difficult to disassemble, and the "disassembly" rating was "○." There was no overflow of the adhesive from the cap 15A, and the "overflow of adhesive" rating was "○." When the amount of adhesive applied was more than 0.06 g, it was difficult to disassemble the cap 15A, and the "decomposability" was rated "○". The adhesive overflowed from the cap 15A, and the "adhesive overflow" was rated "×".

[0036] The disassembly torque of the pipe joint in Patent Document 2 was 1.52 N·m.

[0037] As described above, in the pipe fitting 1 of this embodiment, the portion where the female threaded portion 11cA of the fitting body 10 and the male threaded portion 16aA of the cap 15A are threadedly fitted together is adhered to each other by the adhesive portion 25A. Therefore, it is possible to make it difficult to disassemble the threaded fitting between the fitting body 10 and the cap 15A. The adhesive portion 25A is formed of an epoxy resin, a silicone resin, or an acrylic resin, which is a known material.

[0038] In the manufacturing method of this embodiment, an adhesive is applied to the male thread portion 16aA, and then the cap 15A and the joint body 10 are fitted together, and this adhesive forms the adhesive portion 25A. This makes it difficult to disassemble the threaded fit between the joint body 10 and the cap 15A.

[0039] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and changes, combinations, deletions, etc. of the configuration are also included within the scope that does not deviate from the gist of the present invention. For example, in the above embodiment, the pipe joint 1 does not necessarily have to include the protrusion 12, the packings 20A, 20B, the base members 30A, 30B, the first stoppers 35A, 35B, the spacers 40A, 40B, and the second stoppers 45A, 45B. [Explanation of symbols]

[0040] 1 Pipe fittings 10. Fitting body 11cA Female thread 15A, 15B Cap 16aA Male thread 20A, 20B Packing 25A,25B Adhesive part 30A, 30B Base material 35A, 35B First stopper 40A, 40B Spacer 45A, 45B Second stopper

Claims

1. A joint body having a female thread portion formed on an inner circumferential surface thereof; A cap having an outer circumferential surface formed with a male thread portion that fits into the female thread portion; An adhesive portion that adheres the female thread portion and the male thread portion to each other; A pipe fitting comprising:

2. 2. The pipe joint according to claim 1, wherein the adhesive portion is formed from an epoxy resin, a silicone resin, or an acrylic resin.

3. The pipe joint according to claim 1 or 2, further comprising an annular packing disposed on the inner circumferential surface of the joint body.

4. further comprising an annular base member, an annular first stopper, an annular spacer, and an annular second stopper; 4. The pipe joint according to claim 3, wherein the packing, the base member, the first stopper, the spacer, and the second stopper are arranged in this order on the inner circumferential surface of the joint body in the axial direction of the joint body.

5. A method for manufacturing a pipe joint according to claim 1, comprising the steps of: A method for manufacturing a pipe joint, comprising the steps of applying an adhesive to the male threaded portion and then fitting the cap to the joint body.

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