JP2005233363A - Pipe coupling and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light and inexpensive pipe coupling, dividing functions required for the pipe coupling, and divided into inner and outer parts (a coupling body and an outer skin) which are formed of resin respectively satisfying the functions. <P>SOLUTION: This pipe coupling includes: a coupling body constituting the whole passage formed of resin having a bending elastic modulus of 8,000 to 14,000 MPa (e.g. FORTRON 1140A1) and an outer skin formed of resin having a bending elastic modulus of 800 to 3,000 MPa (e.g. TROGAMIDE CX7323) to cover the coupling body. 1: coupling body 2: passage 3: inner cylinder 11: outer skin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to the structure of a pipe joint. More specifically, the present invention provides a new pipe joint composed entirely of resin.

  In recent years, resin pipes have been widely used for water supply and hot water pipes even in detached houses such as apartment houses, which are placed between water supply and hot water headers and various instruments, and pipe joints are connected to these connecting parts. Is widely used.

  Patent document 1 is mentioned as an example of this pipe joint. FIG. 5 shows this pipe joint. In the figure, 31 is a joint base, and a flow path 32 is formed at the center. An inner cylinder 33 is formed for the flow path 32, and the pipe 20 is inserted into the inner cylinder 33. Reference numeral 34 denotes a pipe holding member, which is provided with a claw 35 facing inward, which bites into the outer surface of the inserted pipe 20 and prevents the pipe 20 from coming off. Reference numeral 36 denotes an annular collet that supports the pipe holding member 34, and reference numeral 37 denotes a cap that covers the pipe holding member 34 and the collet 36 from the outside.

JP 2002-005373 A

  In this pipe joint, the cap 37 is made of resin, but the joint base 31 is usually made of metal (gunmetal). However, since the pipe joint as a whole is heavy, its handling is difficult and expensive.

  The present invention is intended to solve the above-mentioned problems, and separates the functions required for pipe joints into two parts (inside and outside of the joint body) to make a pipe joint with a resin that satisfies each. Thus, a light-weight and inexpensive pipe joint is provided.

  The first gist of the present invention is a joint body constituting the entire flow path made of a resin having a flexural modulus of 8,000 to 14,000 MPa, and this joint body made of a resin having a flexural modulus of 800 to 3,000 MPa. It is applied to a pipe joint made of an outer skin that covers the cover.

  The second gist of the present invention is that a joint body is formed by injecting a resin having a flexural modulus of 8,000 to 14,000 MPa into a mold forming the entire flow path, and then the joint body is formed into a joint outer shape. And a pipe joint manufacturing method characterized in that an outer skin is formed by injecting a resin having a flexural modulus of 800 to 3,000 MPa around the joint body.

  The pipe joint of the present invention and its manufacturing method have the above-described configuration, and it is extremely lightweight as a pipe joint compared to a conventional metal pipe joint, and is easy to handle during construction and as a pipe joint. The cost is significantly reduced.

  Hereinafter, although it demonstrates centering on a pipe joint, in this invention, a pipe joint is divided into the function requested | required and the resin suitable for this is used. First, a joint body is made of a resin having high rigidity, durability, and high water resistance, and is insert-molded so as to cover the periphery with a resin having a low elastic modulus. That is, a joint body is formed by (injection) molding, the joint body is inserted into a mold, and a shell resin is injected to form a skin on the joint body to obtain a pipe joint.

  The joint main body is a part that constitutes the entire flow path and is in direct contact with the fluid, and examples thereof include resins having the above-described properties, such as PPS resin and PP resin reinforced with glass fiber, which are injection-molded. is there. Of course, the molding may be performed by other methods. Such a resin can reduce the cost.

  However, in general, such a resin is weak in impact resistance, and if it is dropped at the construction site, it will crack. For this reason, the outer periphery is formed by covering the periphery of the joint body with a particularly transparent resin having a low bending elastic modulus. Such a resin is, for example, covered with microcrystalline polyamide resin, PP resin, or polybutene resin. The resin referred to here is preferably a transparent resin, and includes a resin having such a transparency that the inside, that is, the tip of the pipe to be inserted can be visually observed.

  As described above, the joint body is preferably formed by accurately forming the pipe insertion part and the flow path by injection molding, and this is set in the mold, and a resin as the outer shell is formed on the outside of the joint by injection molding. To be molded. In such a pipe joint in which two types of resins are laminated, the resin in the outer skin serves as a cushion, and prevents the joint body from cracking when the pipe joint is dropped or subjected to an impact.

  There is no need for press fitting or screwing between the joint body and the outer shell resin, and it is light weight and low cost.

  In addition, the resin of the outer shell is transparent, as described above, the tip of the pipe to be inserted is visible from the outside, and the pipe holding member is inserted by inserting the pipe tip to a predetermined position. It surely bites into the surface of the pipe, and there is no leakage of water due to the disconnection of the pipe.

A suitable resin constituting the inner joint body is PPS resin (manufactured by Polyplastics Co., Ltd .: Fortron 1140A1, Fortron 1130T6 (PPS resin containing 30% glass fiber)).

And what is suitable for comprising transparent resin as an outer_layer | skin is a microcrystalline transparent polyamide resin (Daicel: Torogamide CX7323).

  The bending elastic modulus of the resin of the joint body is preferably 8,000 to 14,000 MPa, and the bending elastic modulus of the resin of the outer skin is 800 to 3,000 MPa.

Hereinafter, the present invention will be described in more detail with reference to examples.
FIG. 1 is a central sectional view of a T-shaped pipe joint having a branch port. In the figure, reference numeral 1 denotes a joint body formed of PPS resin (polyplastics company: Fortron 1140A1) containing 40% by weight of glass fiber, which is obtained by injection molding. The whole is constituted and the inner cylinder 3 is constituted.

  Further, the outer skin 11 is formed on the outer side of the joint body 1, and although not shown, the joint body 1 is set in a mold for forming the outer skin 11, and a microcrystalline polyamide resin (Daicel: Trogamid CX7323) is injected, and a transparent outer skin 11 is formed by a so-called insert method.

  FIG. 2 is a central sectional view of the L-shaped pipe joint. In the figure, 1 is formed from PPS resin (Polyplastic Co., Ltd .: Photron 1140A1) containing 5% by weight of glass fiber, and obtained by injection molding as in FIG. The entire flow path 2 as a joint is configured.

  Further, the outer skin 11 is formed on the outer side of the joint body 1. Although not shown, the joint body 1 is set in a mold for forming the outer skin 11, and in this example, PP resin is injected on the outer side. The transparent outer skin 11 is formed by the so-called insert method.

  FIG. 3 is a central sectional view of a straight pipe joint. The reference numerals are the same as those in FIG.

  The pipe joint obtained here is obtained by covering a joint body 1 that is relatively brittle to impact or the like with a resin having a low bending elastic modulus as an outer skin 11 around the joint body 1. Therefore, even if this is dropped on the floor, the joint body 1 does not directly collide with the floor, and the impact is absorbed to some extent by the outer skin 11, so that the safety as a pipe joint is extremely high. is there.

  FIG. 4 is a cross-sectional view showing a state where the resin pipe 20 is inserted into the straight pipe joint. In the figure, 4 is an O-ring fitted in the circumferential groove of the inner cylinder 3, 5 is a pipe holding member adapted to the shape of the tip of the outer skin 11, and bites into the surface of the resin pipe 20 inside. Nail 6 is formed. Further, a collet 7 for maintaining the shape of the pipe holding member 5 is fitted on the outside. A cap 8 is press-fitted into the outer skin 11 so as to surround them.

  When the resin pipe 20 is inserted into the inner cylinder 3 and is brought into contact with the deepest portion of the joint body 1, the space between the inner cylinder 3 and the resin pipe 20 is sealed by the O-ring 4 and exhibits a water leakage prevention effect. Is done. Then, the claws 6 of the pipe holding member 5 come into contact with the surface of the resin pipe 20. When this pipe joint is actually used, that is, when a fluid is passed through the flow path 2, the resin pipe 20 moves slightly in the direction opposite to the direction in which it is inserted due to the internal pressure. It bites into the surface of the pipe 20 and prevents the resin pipe 20 from coming off here.

  In order to pull out the resin pipe 20 from the pipe joint, the claw 6 is released from biting into the resin pipe 20 by pushing the tail of the collet 7 inward, and the resin pipe 20 is removed in that state. Good.

  Now, when the resin pipe 20 is not completely inserted into the deepest part, the claw 6 is not completely bited into the surface of the resin pipe 20, and the contact with the O-ring 4 is not perfect, and the resin pipe 20 comes off. Or water leakage is expected. Therefore, the resin pipe must be completely inserted, but since the outer skin 11 of the present invention is transparent, it is possible to quickly confirm where the tip of the resin pipe 20 is visually, and the resin pipe 20 is inserted here. It is possible to confirm the completeness of.

  As a pipe joint, it is extremely light (approximately ¼) compared with a conventional metal pipe joint, and the ease of handling at the time of construction and the cost as a pipe joint are remarkably reduced.

FIG. 1 is a central sectional view of a T-shaped pipe joint having a branch port. FIG. 2 is a central sectional view of the L-shaped pipe joint. FIG. 3 is a central sectional view of a straight pipe joint. FIG. 4 is a cross-sectional view showing a state in which a resin pipe is inserted into a straight pipe joint. FIG. 5 is a cross-sectional view of a conventional pipe joint.

Explanation of symbols

1 ... Fitting body,
2.
3. Inner cylinder,
4 ... outer skin,
5. Nail,
6. Pipe holding member
7. Collet
8. Cap,
11 ... Hull,
20 ... Resin pipe.

Claims (7)

  A pipe joint composed of a joint body constituting the entire flow path made of a resin having a flexural modulus of 8,000 to 14,000 MPa and an outer skin covering the joint body made of a resin having a flexural modulus of 800 to 3,000 MPa. The pipe joint according to claim 1, wherein the joint body is formed by injection molding, the joint body is inserted into a mold, and a skin resin is injected to form a skin on the joint body. The pipe joint according to claim 1, wherein the resin constituting the joint body is a PPS resin containing glass fiber. The pipe joint according to claim 1, wherein the resin constituting the outer skin is a transparent microcrystalline polyamide resin.   A joint body is formed by injecting a resin having a flexural modulus of 8,000 to 14,000 MPa into a mold that forms the entire flow path, and then the joint body is set in a mold that defines the joint outer shape. Then, a pipe joint manufacturing method is characterized in that a shell having a bending elastic modulus of 800 to 3,000 MPa is formed around the joint body to form an outer skin. The method for producing a pipe joint according to claim 5, wherein the resin constituting the joint body is a PPS resin containing glass fiber. 6. The method for producing a pipe joint according to claim 5, wherein the resin constituting the outer skin is a transparent microcrystalline polyamide resin.

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