Water-stopping member, method for manufacturing a water-stopping member, and pipe joint

Abstract

Ensures sealing performance on the radially inner side of a water-stopping member that has a water-absorbing and expanding function. [Solution] The water-stopping member is a water-stopping member that is placed in the water-stopping portion between the pipe body 20 and the joint body, and comprises an annular water-absorbing and expanding member 37A having a water-absorbing and expanding function, and an annular non-expanding member 37B that is laminated radially inward of the water-absorbing and expanding member 37A and does not absorb water and expand.

Description

Technical Field

[0001] The present invention relates to a water stop member, a method for manufacturing the water stop member, and a pipe joint for connecting pipe bodies.

Background Art

[0002] Conventionally, a pipe joint is known in which a water stop member such as an O-ring is arranged on a water stop surface between a pipe body and a joint body to stop water. Further, as a water stop member, a water absorption expansion sealing material that expands by absorbing water and seals the water stop surface has been proposed to prevent water leakage (see Patent Document 1).

Prior Art Documents

Patent Documents

[0009] In the water-stopping member according to the second embodiment, the water-absorbing and expanding member has a water-contact area increasing portion that increases the contact area between the water that has entered the water-stopping portion and the water-stopping member, thereby causing the water-stopping member to expand radially.

[0010] According to the water-stopping member of the second embodiment, since a portion with an increased water-contacting surface area is formed, the expansion of the water-absorbing and expanding member of the water-stopping member is promoted, and the time until the water-stopping function is achieved can be shortened.

[0011] In the third embodiment, the water-stopping member is formed by a slit extending along the axial direction in which the water-contacting area is increased.

[0012] According to the third embodiment of the water-stopping member, water can be allowed to enter the portion where the slit is formed, thereby increasing the water-contact area of ​​the water-stopping member.

[0013] The pipe joint according to the fourth embodiment comprises a tubular joint body connected to a pipe body, with a watertight portion formed between it and the pipe body, and a watertight member according to any of the first to third embodiments arranged in the watertight portion.

[0014] According to the pipe joint of the fourth embodiment, a non-water-absorbing, non-expanding member is laminated on the radially inner side of the water-stopping member, so that the radial expansion of the inner side of the water-stopping member is suppressed, and the sealing performance on the radially inner side of the water-stopping member can be ensured.

[0015] A method for manufacturing a water-stopping member according to the fifth embodiment is a method for manufacturing a water-stopping member according to any one of the first to third embodiments, wherein a laminated sheet having a water-absorbing and expanding layer having a water-absorbing and expanding function and a non-expanding layer that does not absorb and expand is punched out in an annular shape to form a laminated ring, and the laminated ring is deformed so that the water-absorbing and expanding layer is positioned radially outward and the non-expanding layer is positioned radially inward.

[0016] According to the manufacturing method of the water stop member according to the fifth aspect, the water stop member can be manufactured simply.

Effect of the Invention

[0017] According to the present invention, it is possible to ensure the sealing property on the radially inner side of the water stop member having a water absorption expansion function.

Brief Description of the Drawings

[0018] [Figure 1] Regarding the pipe joint according to the first embodiment, (A) is a cross-sectional view showing the state before the pipe body is inserted, and (B) is a cross-sectional view showing the state after the pipe body is inserted. [Figure 2] It is a cross-sectional view of the joint main body part and the water stop ring of the pipe joint according to the first embodiment. [Figure 3] It is a perspective view of the water stop ring of the pipe joint according to the first embodiment. [Figure 4] It is an explanatory view of the manufacturing steps (A) to (D) of the water stop ring. [Figure 5] It is a perspective view of the water stop ring according to the modified example. [Figure 6] Regarding the pipe joint according to the second embodiment, (A) is a cross-sectional view showing the state before the pipe body is inserted, and (B) is a cross-sectional view showing the state after the pipe body is inserted.

Mode for Carrying Out the Invention

[0019] Hereinafter, the pipe joint according to the embodiment of the present invention will be specifically described with reference to the accompanying drawings.

[0020] [First Embodiment] The pipe joint 10 of the first embodiment includes a joint main body portion 30 and a joint peripheral portion 40. The joint main body portion 30 has an inner cylinder portion 31 formed in a cylindrical shape and a connection portion 32 formed continuously at one end of the inner cylinder portion 31. A threaded portion is formed on the outer peripheral surface of the connection portion 32 so that it can be screwed and connected to another pipe body. Between the inner cylinder portion 31 and the connection portion 32, a hexagonal portion 32A having a larger outer diameter than the inner cylinder portion 31 and the connection portion 32 is formed. Also, a flow path R is formed on the inner peripheral side of the inner cylinder portion 31 and the connection portion 32.

[0021] The joint peripheral portion 40 has a holding member 41 formed in a cylindrical shape, a claw member 42 formed in a ring shape, a release ring 43, and a cap 44. The holding member 41 is disposed on the outer peripheral side of the inner cylinder portion 31, and the claw member 42 and the release ring 43 are arranged side by side at one end of the holding member 41. The cap 44 is installed so as to cover these holding member 41, claw member 42, and release ring 43 from the outer peripheral side, preventing the holding member 41, claw member 42, and release ring 43 from coming out of the joint main body portion 30.

[0022] A pipe body insertion space 21 into which the pipe body 20 is inserted is formed between the inner cylinder portion 31 and the holding member 41. The pipe body 20 inserted into the pipe body insertion space 21 is prevented from coming out by the claw member 42 attached to one end of the holding member 41 biting into the outer periphery. By pushing the release ring 43 provided together with the claw member 42 toward the claw member 42 side and expanding the diameter of the claw member 42 to release the biting, the pipe body 20 can be pulled out from the pipe body insertion space 21. Also, the end portion of the inner cylinder portion 31 on the connection portion 32 side has an enlarged flange portion 33, and the pipe body 20 can be inserted until it reaches this flange portion 33.

[0023] Hereinafter, the direction along the axis L of the inner cylinder portion 31 is referred to as the axial direction, and the direction orthogonal to the axis L is referred to as the radial direction. Also, regarding the axial direction of the pipe joint 10, the connection portion 32 side is referred to as the back side, and the pipe body 20 side is referred to as the front side.

[0024] The outer circumferential surface of the inner cylinder portion 31 has circumferential grooves 34 and 35 formed therein, which are recesses extending around the entire circumference. The circumferential groove 34 is formed closer to the tip of the inner cylinder portion 31 than the circumferential groove 35. The circumferential groove 35 is longer in the axial direction L than the circumferential groove 34. An O-ring 36 is fitted into the circumferential groove 34, and a water-sealing ring 37 is fitted into the circumferential groove 35. The area including the circumferential grooves 34 and 35 and their vicinity on the outer circumferential surface of the inner cylinder portion 31 forms a water-sealing section.

[0025] The O-ring 36 is primarily made from materials that do not absorb water and swell, or have low water absorption and swelling properties, such as SBR, EPDM, CR, butyl rubber, silicone, polysulfur rubber, and chlorosulfonated polyethylene rubber.

[0026] As shown in Figures 2 and 3, the water-sealing ring 37 has a rectangular cross-section and is an annular shape. The water-sealing ring 37 is formed by laminating two layers in the radial direction: a water-absorbing and expanding member 37A and a non-expanding member 37B. The radially outer layer is the annular water-absorbing and expanding member 37A, and the radially inner layer is the annular non-expanding member 37B.

[0027] The water-absorbing and expanding member 37A has a water-absorbing and expanding function and is formed by including a water-absorbing and swelling material. Examples of water-absorbing and swelling materials include rubber that absorbs water and swells itself, such as urethane rubber, non-swelling rubbers such as NBR, SBR, and EPDM, and EVA resin or vinyl chloride resin mixed with polyacrylic acid-based, popal-based, polyoxyethylene-based, cellulose-based, or starch-based superabsorbent resins. The non-expanding member 37B can be formed from the same material as the O-ring 36.

[0028] As shown in Figure 2, before being fitted into the circumferential groove 35, the inner diameter R1 of the water-sealing ring 37 is smaller than the diameter R2 of the bottom of the circumferential groove 35. Therefore, when attaching the water-sealing ring 37 to the circumferential groove 35, the inner diameter of the water-sealing ring 37 is stretched by elastic deformation, and even after attachment, it is fitted in a slightly stretched state.

[0029] As shown in Figure 3, a slit 37C is formed in the water-absorbing and expanding member 37A of the water-sealing ring 37. The slit 37C is formed in a circular shape around the entire circumference in the radial middle portion of the water-absorbing and expanding member 37A, i.e., in the central portion of its thickness, when viewed from the axial direction. The slit 37C is formed from the upstream end of the water-sealing ring 37 in the direction of water intrusion when viewed from the side, and has a length S that does not extend to the other end. Preferably, the axial length S of the slit 37C is 1 / 2 or more of the axial length of the water-sealing ring 37.

[0030] Next, the manufacturing method of the water-stopping ring 37 will be explained.

[0031] First, as shown in Figure 4(A), a sheet SH is prepared in which a water-absorbing and expanding layer SH1, which will become the water-absorbing and expanding member 37A, and a non-expanding layer SH2, which will become the non-expanding member 37B, are laminated. Next, as shown in Figure 4(B), a ring shape is punched out by punching. Then, as shown in Figure 4(C), it is rotated by 90° so that the non-expanding layer SH2 is on the radially inner side and the water-absorbing and expanding layer SH1 is on the radially outer side. Then, a slit 37C is formed.

[0032] In this way, the water-stopping ring 37 can be easily manufactured.

[0033] Next, the operation of the pipe joint 10 will be explained.

[0034] As shown in Figure 1(A), the pipe 20 is positioned facing the opening side of the pipe insertion space 21. Then, as shown in Figure 1(B), it is inserted until the tip abuts against the flange portion 33. In this inserted state, the O-ring 36 is compressed by the bottom of the circumferential groove 34 and the pipe 20, sealing the space between the outer surface of the inner cylinder portion 31 and the inner surface of the pipe 20. The claw member 42 bites into the outer surface of the pipe 20, preventing the pipe 20 from coming out.

[0035] In this state, for example, if foreign matter (such as a hair) is caught in the O-ring 36, water leakage will occur. The water leakage will occur as water gradually seeps in from the front to the back of the inner cylinder portion 31 and reaches the water-sealing ring 37. The water-absorbing and expanding member 37A of the water-sealing ring 37 has a water-absorbing and expanding function, so it expands and seals the space between the outer surface of the inner cylinder portion 31 and the inner surface of the pipe body 20.

[0036] In this embodiment, the water-sealing ring 37 has a non-expanding member 37B laminated inside the water-absorbing and expanding member 37A, so that the expansion of the inner diameter when it absorbs water is suppressed. Therefore, the sealing performance on the radially inner side of the water-sealing ring 37 can be ensured.

[0037] Furthermore, since the water-stopping ring 37 of this embodiment has a slit 37C formed therein, water that enters the circumferential groove 35 enters the slit 37C, increasing the area in direct contact with water (water-contact area) of the water-absorbing and expanding member 37A. As a result, the expansion of the water-absorbing and expanding member 37A is accelerated compared to the case where the slit 37C is not formed, and the time until the water-stopping function is achieved can be shortened.

[0038] Furthermore, since the slit 37C in this embodiment is formed from the upstream end in the water ingress direction, water can easily enter the slit 37C, shortening the time until the water-stopping function is activated.

[0039] Furthermore, since the slit 37C in this embodiment is formed over the entire circumference in the middle of the radial direction when viewed from the axial direction, it can effectively promote the expansion of the water-sealing ring 37 radially outward across the slit 37C.

[0040] In this embodiment, a slit 37C was formed, but the slit 37C is not essential.

[0041] Furthermore, since the water-stopping ring 37 of this embodiment is fitted into the circumferential groove 35 with its inner diameter stretched by elastic deformation, even if the inner diameter increases due to radial outward expansion, a gap is less likely to form between the ring and the bottom of the circumferential groove 35.

[0042] Furthermore, although the water-stopping ring 37 is formed in two layers in this embodiment, as shown in Figure 5, a water-absorbing and expanding member 37A may be formed radially inside the non-expanding member 37B.

[0043] [Second Embodiment] Next, a second embodiment will be described. In this embodiment, the same parts as in the first embodiment are denoted by the same reference numerals, and their detailed descriptions will be omitted. The pipe joint 50 in this embodiment seals the outer surface of the pipe body 20.

[0044] As shown in Figures 6(A) and 6(B), the pipe fitting 50 comprises a fitting body 52, an inner circumferential support member 53, a cap 54, a collet 56, an O-ring 36, and a water-stopping ring 37.

[0045] The joint body 52 is cylindrical and consists of a first inner wall portion 52A, a second inner wall portion 52B, and a third inner wall portion 52C, in order from the insertion side of the pipe body 20. The inner diameter of the first inner wall portion 52A is larger than the inner diameter of the second inner wall portion 52B, and the inner diameter of the second inner wall portion 52B is larger than the inner diameter of the third inner wall portion 52C. The third inner wall portion 52C forms part of the flow path. A stepped portion 52D1 is formed between the first inner wall portion 52A and the second inner wall portion 52B, and a stepped portion 52D2 is formed between the second inner wall portion 52B and the third inner wall portion 52C. A male thread 52N is formed on the outer circumference of the joint body 52 corresponding to the first inner wall portion 52A.

[0046] The cap portion 54 is annular in shape, and a female thread 54N is formed on its inner wall that screws onto the male thread 52N. The cap portion 54 is connected to the joint body 52 by the female thread 54N screwing onto the male thread 52N. On the side of the cap portion 54 that is inserted into the pipe body 20, an insertion opening portion 54A is formed, which has a smaller inner diameter than the first inner wall portion 52A of the joint body 52.

[0047] Inside the first inner wall portion 52A, between the insertion opening portion 54A and the stepped portion 52D, a collet 56, a watertight ring 37, and an O-ring 36 are arranged in that order from the insertion opening portion 54A. The watertight ring 37 has a slit 37C positioned on the O-ring 36 side. The collet 56 is annular in shape and prevents the watertight ring 37 and the O-ring 34 from coming off and positions them correctly.

[0048] The inner circumferential support member 53 is cylindrical in shape with a flange 53A formed at its tip. The flange 53A abuts against the stepped portion 52D, and an insertion space 51 is formed between the inner circumferential support member 53 and the collet 56.

[0049] Next, the function of the pipe joint 50 will be explained.

[0050] As shown in Figure 6(A), the pipe body 20 is positioned opposite the insertion opening 54A. Then, as shown in Figure 6(B), the pipe body 20 is inserted into the insertion space 51, and its tip is brought into contact with the stepped portion 52D2. In this inserted state, the O-ring 36 is compressed by the first inner wall portion 52A and the pipe body 20, sealing the space between the first inner wall portion 52A and the outer surface of the pipe body 20.

[0051] In this state, for example, if foreign matter (such as hair) is caught in the O-ring 36, water leakage will occur. Due to the water leakage, water gradually seeps in from the third inner wall portion 52C side of the O-ring 36 to the water-sealing ring 37 side. The water-absorbing and expanding member 37A of the water-sealing ring 37 has a water-absorbing and expanding function, so it expands and seals the space between the outer surface of the first inner wall portion 52A and portion 31 and the inner surface of the pipe body 20.

[0052] In this embodiment, the water-sealing ring 37 also has a non-expanding member 37B laminated inside the water-absorbing and expanding member 37A, so that the expansion of the inner diameter when it absorbs water is suppressed. Therefore, the sealing performance on the radially inner side of the water-sealing ring 37 can be ensured.

[0053] Furthermore, because the slit 37C is formed, the water that enters enters the slit 37C, increasing the area in direct contact with the water (water-contacting area) of the water-absorbing and expanding member 37A. As a result, the expansion of the water-absorbing and expanding member 37A is accelerated compared to when the slit 37C is not formed, and the time until the water-stopping function is activated can be shortened.

[0054] Furthermore, since the slit 37C in this embodiment is formed at the upstream end in the water ingress direction, water can easily enter the slit 37C, shortening the time until the water-stopping function is activated.

[0055] Although the first and second embodiments of the present invention have been described above, the components in the above embodiments can be replaced with other components as appropriate without departing from the spirit of the present invention, and the above embodiments can also be combined as appropriate. [Explanation of symbols]

[0056] 10 Pipe fittings 20 tubular body 30. Fitting body (fitting body) 37. Water-stopping ring (water-stopping component) 37A Water-absorbing and expanding member 37B Non-expansion member 37C Slit 50 Pipe Fittings 52 Fitting body

Claims

1. A water-stopping member that is placed in the water-stopping section between the pipe body and the joint body, An annular water-absorbing and expanding member having a water-absorbing and expanding function, Laminated radially inward of the aforementioned water-absorbing and expanding member is a non-water-absorbing, annular, non-expanding member, A water-stopping component equipped with the following features.

2. The water-absorbing and expanding member has a water-contact area increasing portion that increases the contact area between the water that has entered the water-stopping portion and the water-stopping member, thereby causing the water-stopping member to expand radially. The water-stopping member according to claim 1.

3. The portion with increased water contact area is formed by a slit extending along the axial direction. The water-stopping member according to claim 2.

4. A tubular joint body that connects to a pipe and forms a watertight seal between it and the pipe, A water-stopping member according to any one of claims 1 to 3, disposed in the water-stopping portion, A pipe fitting equipped with [a specific feature].

5. A method for manufacturing a water-stopping member according to any one of claims 1 to 3, A laminated sheet, consisting of a water-absorbing and expanding layer and a non-water-absorbing and non-expanding layer, is punched out in a ring shape to form a laminated ring. The laminated ring is deformed so that the water-absorbing and expanding layer is positioned radially outward and the non-expanding layer is positioned radially inward. A method for manufacturing a water-stopping component.

Images