JP6941528B2 - Fittings and fitting manufacturing methods - Google Patents

Description

The present invention relates to a joint having excellent fire resistance, a piping structure provided with the joint, and a method for manufacturing the joint.

A drainage system (piping structure) for buildings and the like is known to be composed of a plurality of resin pipes and resin joints (hereinafter, also simply referred to as "joints") for connecting the resin pipes to each other. ing. Such a joint includes a main body and a socket formed so that a resin pipe can be fitted inside.

The material of the joint is appropriately selected according to the function to be imparted to the joint. Further, as a method for manufacturing a joint, injection molding in which a resin material is injected into a mold to form a resin is often used. However, for example, when trying to make only the socket transparent so that the insertion condition of the resin pipe into the socket can be confirmed, a transparent resin is selected as the material of the joint, and a uniaxial injection molding machine is used. When a joint is injection-molded with a single transparent resin, not only the socket but also the main body becomes transparent. That is, when a joint is injection molded with a single material, the function of the joint is determined by the characteristics of the single material.

However, there are cases where it is desired to form the main body and the socket with the same common material and to superimpose a material different from the common material on either the main body and the socket. For example, in Patent Document 1, a joint in which the outer layer of the socket and the main body are made of a resin material capable of absorbing the thermal stretching stress of the resin pipe, and the inner layer of the socket is made of a resin material that can be adhesively bonded to the resin pipe. Is disclosed.

Japanese Unexamined Patent Publication No. 2011-002012

The joint described in Patent Document 1 can be manufactured by insert molding. In insert molding, the socket or the main body (first member) is molded in advance, the molded first member is fitted into the core of the mold, and then a resin material different from the first member (first member) is formed around the first member. 2 Resin) is injected to integrate the first member and the second member. However, when a conventional uniaxial injection molding machine is applied to insert molding, it is difficult to first deform the first member according to the cavity of the mold (that is, the flow path of the resin material of the second member). There was a problem that the first member could not be mounted on the mold or the first member was damaged. On the other hand, if the shape of the mold is changed individually for the joint or if a two-shaft injection molding machine is prepared, there is a concern that the manufacturing cost will increase.

The present invention has been made in view of the above circumstances, and is a joint that can be easily manufactured by insert molding using a conventional uniaxial injection molding machine, a piping structure provided with the joint, and the joint. Provide a manufacturing method.

The joint according to the present invention includes a main body formed in a tubular shape and having a plurality of openings, and a socket provided in the plurality of openings, and one of the main body and the socket has two layers. The structure is composed of a single-layer structure, and the inner layer of either the main body or the socket has a tubular first member formed of the first resin, and either the main body or the socket. One outer layer and the other have a second member formed of a second resin different from the first resin, and the first member and the second member are integrally formed on the first member. Is characterized in that a cut portion along the axial direction is formed.

In the above-mentioned joint, at the time of manufacturing by insert molding using a conventional uniaxial injection molding machine, both ends of the cut portion are separated and the first member is fitted into the core of the mold to easily make the first member. Can be attached to the mold. Subsequently, as in the conventional method, if the second resin is injected around the first member (that is, the gap between the mold and the first member), the second member is integrally molded with the first member, which is different. A joint in which resin materials are partially laminated can be easily manufactured. In addition, it can be manufactured using a conventional uniaxial injection molding machine, and it is necessary to individually change the shape of the core or cavity (mold) for the joint or prepare a biaxial injection molding machine. Therefore, it is possible to suppress an increase in the manufacturing cost of the joint.

Further, in the joint according to the present invention, the cut portion has a predetermined width in the circumferential direction of the first member, and the second resin may intervene in the cut portion.

In the above-mentioned joint, since the second resin is interposed in the cut portion, the joint strength between the first member and the second member can be increased.

In the joint according to the present invention, the first member may have a slit formed at a position different from that of the cut portion in the circumferential direction, and the slit may be formed along the axial direction of the first member.

In the above-mentioned joint, in addition to separating both ends of the cut portion along the circumferential direction of the first member, the both ends of the slit are separated along the radial direction of the first member to deform the first member. The degree of freedom can be expanded. By increasing the degree of freedom of deformation, it becomes easy to attach the first member to the mold regardless of the shape of the mold. Further, if the slit has a predetermined width in the circumferential direction of the first member and the second resin is interposed in the slit, the degree of bonding between the first member and the second member can be further increased.

The piping structure according to the present invention is characterized by including the above-mentioned joint and a resin pipe fitted in a receiving port of the joint.

In the above-mentioned piping structure, the above-mentioned joint can be manufactured by insert molding using a uniaxial injection molding machine as in the conventional method. Further, in the above-mentioned piping structure, it is not necessary to individually change the shape of the core or cavity for the joint or prepare a biaxial injection molding machine, so that the increase in the manufacturing cost of the piping structure can be suppressed. Can be done.

The method for manufacturing a joint according to the present invention is the above-mentioned method for manufacturing a joint, which includes a first member forming step of molding the first member and forming the cut portion along the axial direction of the first member. , The first member mounting step of mounting the first member on the mold, and the second member of injecting the second resin around the first member and molding the second member integrally with the first member. It is characterized by including a molding process.

In the above-mentioned joint manufacturing method, in the first member mounting step, both ends of the cut portion of the first member are expanded and the first member is fitted into the mold, whereby the first member is easily mounted on the mold. can do. Subsequently, in the second member molding step, the second member can be molded integrally with the first member to easily manufacture a joint in which different resin materials are partially laminated. Further, since it can be manufactured by using a conventional uniaxial injection molding machine and it is not necessary to change the shape of the mold individually for the joint, it is possible to suppress an increase in the manufacturing cost of the joint.

According to the joint, the piping structure, and the method for manufacturing the joint according to the present invention, it is possible to easily manufacture a joint in which different resin materials are partially laminated by using a conventional uniaxial injection molding machine.

It is a perspective view of the piping structure provided with the joint of the 1st Embodiment to which this invention is applied. It is a partial cross-sectional view of the piping structure shown in FIG. 1, and is a cross-sectional view taken along the line EE shown in FIG. It is a perspective view of the 1st member of the joint shown in FIG. It is a perspective view for demonstrating the manufacturing method of the joint shown in FIG. It is a perspective view of the 1st member of the joint of the 2nd Embodiment to which this invention was applied. It is a perspective view of the 1st member of the joint of 3rd Embodiment to which this invention was applied. It is a perspective view for demonstrating the manufacturing method of the joint of the 3rd Embodiment to which this invention is applied. It is a perspective view of the 1st member of the joint of 4th Embodiment to which this invention was applied. It is a perspective view of the 1st member of the joint of 5th Embodiment to which this invention was applied. It is a perspective view of the piping structure provided with the joint of the 1st Embodiment to which this invention is applied. It is a partial cross-sectional view of the piping structure shown in FIG. 10, and is a cross-sectional view taken along the line FF shown in FIG.

Hereinafter, embodiments of the joint, the piping structure, and the method for manufacturing the joint according to the present invention will be described with reference to the drawings. The drawings used in the following description are schematic, and the length, width, thickness ratio, etc. are not always the same as the actual ones and can be changed as appropriate.

(First Embodiment)
[Joints and piping structure]
As shown in FIG. 1, the piping structure 70 of the first embodiment to which the present invention is applied includes a resin joint 1 and a resin pipe 4 connected to a receiving port 3 of the joint 1. The piping structure 70 constitutes, for example, a drainage system of a building.

The joint 1 includes a tubular main body 2 and receiving ports 3 provided in each of the plurality of openings 5 of the main body 2. The joint 1 of the present embodiment is a so-called cheese joint. The main body 2 includes a straight pipe portion 41 and a branch portion 42 that branches from the middle of the straight pipe portion 41 in the axial direction along a direction orthogonal to the axial direction. The receiving ports 3 are provided at both ends of the straight pipe portion 41 in the axial direction and at a total of three openings 5 at the tip of the branch portion 42. That is, the joint 1 includes three sockets 3A, 3B, and 3C. Hereinafter, when explaining the configuration common to the sockets 3A, 3B, and 3C, these sockets 3A, 3B, and 3C are collectively referred to as the socket 3. The end portion of the resin tube 4 is internally fitted in the receiving port 3 via the adhesive 8.

In the joint 1, the main body 2 has a two-layer structure, and the socket 3 has a single-layer structure. As shown in FIG. 2, the inner layer of the main body 2 has a tubular first member 12 formed of the first resin. The outer layer of the main body 2 and the receiving port 3 have a second member 13 made of a second resin different from the first resin. The first member 12 and the second member 13 are integrally formed by insert molding or the like.

The first resin and the second resin are appropriately selected according to the function to be imparted to the joint 1. In the present embodiment, for the purpose of increasing the transparency of the socket 3 and imparting fire resistance to the joint 1, the first resin is, for example, polyvinyl chloride resin (PVC) having excellent fire resistance or chlorinated polyvinyl chloride. It is preferable to use a mixed resin in which a fire-resistant agent such as heat-expandable graphite, aluminum hydroxide, magnesium hydroxide, or a flame retardant is blended with a resin such as vinyl resin (CPVC). CPVC is a chlorinated product of polyvinyl chloride resin (PVC). Further, as the second resin, for example, it is preferable to use PVC, ABS resin, or MBS resin which is transparent and easy to mold.

As shown in FIGS. 2 and 3, the first member 12 is formed into a cylindrical shape by injection molding or the like using a uniaxial injection molding machine. A plurality of convex portions 33 are provided on the outer peripheral surface 12a of the first member 12 with a predetermined interval G33 along the axial direction. As shown in FIG. 3, the convex portion 33 is formed over the entire circumferential direction of the first member 12. The convex portion 33 may be provided intermittently in the circumferential direction. Further, an opening 44 is formed in the outer peripheral surface 12a of the first member 12 to communicate the hollow portion of the first member 12 and the hollow portion of the branch portion 42 (see FIG. 1).

A cutting portion 51 along the axial direction is formed on the outer peripheral surface 12a of the first member 12. As shown in FIGS. 3 and 4, the cut portion 51 is formed so that the side ends 51p and 51q in the circumferential direction are in contact with each other in a natural state (that is, a state in which the cut portion 51 is not deformed by an external force or the like) and has a width. No.

As shown in FIG. 1, all the outer layers of the joint 1 are composed of the second member 13. As shown in FIG. 2, the second member 13 has a laminated portion 21 in contact with the first member 12 and a single-layer portion 22 having a single-layer structure of the joint 1. A concave portion 34 that fits into the convex portion 33 of the first member 12 is formed on the inner peripheral surface 21b of the abutting portion 21. By fitting the convex portion 33 and the concave portion 34, the joint strength between the first member 12 and the second member 13 is increased. The concave portion 34 extends over the entire circumferential direction of the second member 13, but when the convex portion 33 is provided intermittently in the circumferential direction of the first member 12, the concave portion 34 is provided in the circumferential direction of the second member 13. It may be provided intermittently in.

[Manufacturing method of fittings]
Next, a method of manufacturing the joint according to the present embodiment will be described. The method for manufacturing the joint of the present embodiment is a method for manufacturing the joint 1, at least forming the first member 12 and forming the cut portion 51 along the axial direction of the first member 12. A step, a first member mounting step of mounting the first member 12 on a mold, a second member M13 being injected around the first member 12, and a second member 13 being integrally molded with the first member 12. It includes a two-member molding process.

In the first member forming step, the tubular body (not shown) which is the basis of the first member 12 illustrated in FIGS. 1 to 3 is formed by injection molding using a uniaxial injection molding machine as in the conventional method. Mold. The first member 12 is formed by using CPVC as the first resin. After that, an opening 44, a cutting portion 51, and slits 52A and 52B are formed in the tubular body. The opening 44 may be formed at the time of injection molding.

Next, as shown in FIG. 4, in the first member mounting step, the side ends 51p and 51q are separated so that the cutting portion 51 expands, and the first member 12 is moved from the radial outside of the mold to the core 100. Fit. Since the first member 12 is twisted in this way and the first member 12 is greatly deformed, it becomes easy to fit the first member 12 into the core 100. As described above, the first member 12 is easily mounted on the mold by fitting the first member 12 into the core 100 along the radial direction from the radial outside of the core 100.

Next, in the second member molding step, the second resin M13 is injected around the first member 12, that is, into a cavity (flow path) (not shown). The second member 13 is formed by using transparent PVC as the second resin. Subsequently, the second resin M13 is cured in the same manner as the conventional injection molding under conditions suitable for the second resin M13 (molding temperature, molding time, etc.), and the second member 13 is molded integrally with the first member 12. ..
The joint 1 is completed through each of the above steps.

The joint 1 of the first embodiment described above includes a first member 12 and a second member 13, and a cut portion 51 is formed in the first member 12. According to the configuration of the joint 1, at the time of manufacturing by insert molding using a conventional uniaxial injection molding machine, the side ends 51p and 51q of the cutting portion 51 are separated from each other, and the first member 12 is moved in the radial direction of the mold. By fitting the first member 12 into the core 100 along the line, the first member 12 can be easily attached to the mold. Subsequently, as in the conventional method, if the second resin M13 is injected around the first member 12 (that is, the flow path of the mold), the second member 13 is integrally formed with the first member 12 and the joint is formed. 1 can be easily manufactured. The joint 1 can be manufactured by using a conventional single-screw injection molding machine, and it is necessary to individually prepare a mold for the joint 1 having a different shape or to prepare an expensive two-screw injection molding machine. There is no. Therefore, the joint 1 in which different resin materials are partially laminated can be easily manufactured without incurring a high cost.

Since the piping structure 70 of the first embodiment includes the joint 1, it has the same effect as that of the joint 1 described above.

In the joint manufacturing method of the first embodiment, the cut portion 51 is formed on the first member 12 at least in the first member forming step. Subsequently, in the first member mounting step, the first member 12 is appropriately deformed by separating the side ends 51p and 51q of the cutting portion 51 in the circumferential direction, and the first member 12 is deformed appropriately from the radial outside of the core 100 of the mold. The member 12 can be easily fitted to the core 100. Therefore, in the joint manufacturing method of the present embodiment, the joint 1 in which different resin materials are partially laminated can be easily manufactured by using a conventional uniaxial injection molding machine.

(Second Embodiment)
Next, the joint, the piping structure, and the method of manufacturing the joint of the second embodiment to which the present invention is applied will be described. In each of the following embodiments, the contents common to the above-described first embodiment will be omitted, and the contents different from the first embodiment will be described.

The joint of the second embodiment is obtained by replacing the first member 12A of the joint 1 of the first embodiment shown in FIGS. 1 and 2 with the first member 12B shown in FIG. As shown in FIG. 5, the cut portion 51 of the first member 12 may be formed so that the side ends 51p and 51q are separated from each other in a natural state, and may have a width W51. Although not shown, the second resin of the second member 13 is interposed in the cut portion 51.

The piping structure of the second embodiment is a joint provided with the first member 12B instead of the first member 12A, and a resin pipe 4 similar to the piping structure 70 is fitted into each receiving port of the joint. ..

The joint manufacturing method of the second embodiment includes the same steps as the joint manufacturing method of the first embodiment.

In the joint of the second embodiment described above, the cut portion 51 has a width W51, and the second resin of the second member 13 is interposed in the cut portion 51. By interposing the second resin in the cut portion 51, the first member 12 and the second member 13 are engaged with each other in the cut portion 51, and the joint strength between the first member 12 and the second member 13 is increased.

According to the method of manufacturing the pipe structure and the joint of the second embodiment, the same effect as the method of manufacturing the pipe structure and the joint of the first embodiment can be obtained.

(Third Embodiment)
Next, a joint, a piping structure, and a method for manufacturing the joint according to the third embodiment to which the present invention is applied will be described.

The joint of the third embodiment is obtained by replacing the first member 12A of the joint 1 of the first embodiment shown in FIGS. 1 and 2 with the first member 12C shown in FIG. As shown in FIG. 6, slits 52A and 52B are formed on the outer peripheral surface 12a of the first member 12 at positions different from those of the cutting portion 51 in the circumferential direction. The slits 52A and 52B are formed along the axial direction (the axial direction of the first member). The slit 52A is formed from the axial end 12c of the first member 12 toward the center and has a predetermined length. The slit 52B is formed from the axial end 12d of the first member 12 toward the center, and has substantially the same length as the slit 52A. In the axial direction of the first member 12, the slits 52A and 52B are separated from each other with the connecting portion 54 interposed therebetween. The slits 52A and 52B are formed so that the side ends 52p and 52q in the circumferential direction are in contact with each other in the natural state, and have no width.

The piping structure of the third embodiment is a joint provided with the first member 12C instead of the first member 12A, and a resin pipe 4 similar to the piping structure 70 is fitted into each receiving port of the joint. ..

The joint manufacturing method of the third embodiment includes the same steps as the joint manufacturing method of the first embodiment.
In the first member mounting step of the present embodiment, the side ends 51p and 51q of the cutting portion 51 are separated from each other according to the shape of the core 100 and the like, and as shown in FIG. 7, the side ends 52p of the slits 52A and 52B are separated. , 52q may be twisted apart. Specifically, with the connecting portion 54 between the slits 52A and 52B as a fulcrum, the side end 52p of the slit 52A is shifted inward in the radial direction of the first member 12, and the side end 52q of the slit 52A is radially outside. You may shift it to. Then, the side end 52p of the slit 52B shifts upward in the radial direction, and the side end 52q of the slit 52B shifts inward in the radial direction. In this way, the first member 12 can be further deformed and fitted into the core 100 of the mold.

In the joint of the third embodiment described above, since the slits 52A and 52B are formed in the first member 12, the amount of deformation of the first member 12 is larger than that in the case where the slits 52A and 52B are not formed. can do.

According to the piping structure of the third embodiment, the same effect as that of the piping structure of the first embodiment can be obtained.

In the joint manufacturing method of the third embodiment, in the first member mounting step, in addition to expanding the first member 12 by separating the side ends 51p and 51q of the cutting portion 51, the side ends of the slits 52A / 52B By separating 52p and 52q, the first member 12 can be twisted and the amount of deformation of the first member 12 can be increased. When fitting the first member 12 into the core 100 of the mold, it is necessary to expand the cut portion 51, but since the slits 52A and 52B are formed, the first member 12 is formed regardless of the shape of the core 100 and the like. The member 12 can be easily attached to the core 100 of the mold.

(Fourth Embodiment)
Next, the joint, the piping structure, and the method of manufacturing the joint according to the fourth embodiment to which the present invention is applied will be described.

The joint of the fourth embodiment is obtained by replacing the first member 12A of the joint 1 of the first embodiment shown in FIGS. 1 and 2 with the first member 12D shown in FIG. As shown in FIG. 8, the cut portion 51 of the first member 12 is formed so that the side ends 51p and 51q are separated from each other in a natural state, and has a width W51. Although not shown, the second resin of the second member 13 is interposed in the cut portion 51.

Further, the slits 52A and 52B formed in the same manner as in the third embodiment are formed so that the side ends 52p and 52q are separated from each other in a natural state, and have a width W52. The second resin of the second member 13 is interposed in the slits 52A and 52B. Since the second resin is interposed in the slits 52A and 52B, the first member 12 and the second member 13 are engaged in the slits 52A and 52B in addition to the cut portion 51, so that the first member 12 and the second member 13 are engaged. The joint strength with and is increased.

The piping structure of the fourth embodiment is a joint provided with the first member 12D instead of the first member 12A, and a resin pipe 4 similar to the piping structure 70 is fitted into each receiving port of the joint. ..

The joint manufacturing method of the fourth embodiment includes the same steps as the joint manufacturing method of the third embodiment.

In the joint of the fourth embodiment described above, the slits 52A and 52B have a width W52, and the second resin of the second member 13 is interposed in the slits 52A and 52B. By interposing the second resin in the slits 52A and 52B, the first member 12 and the second member 13 are engaged with each other in the slits 52A and 52B, and the joint strength between the first member 12 and the second member 13 is increased.

According to the method for manufacturing the pipe structure and the joint according to the fourth embodiment, the same effect as the method for manufacturing the pipe structure and the joint according to the third embodiment can be obtained.

(Fifth Embodiment)
Next, the joint, the piping structure, and the method of manufacturing the joint according to the fifth embodiment to which the present invention is applied will be described.

The joint of the fifth embodiment is obtained by replacing the first member 12A of the joint 1 of the first embodiment shown in FIGS. 1 and 2 with the first member 12E shown in FIG. As shown in FIG. 9, a slit 52E is formed on the outer peripheral surface 12a of the first member 12 at a position different from that of the cutting portion 51 in the circumferential direction. The slit 52E is formed from the end 12c to the end 12d of the first member 12 along the axial direction (the axial direction of the first member). The slit 52E is composed of a groove recessed inward in the radial direction from the outer peripheral surface 12a of the first member 12. In the cross-sectional view seen from the direction along the axial direction, the shape of the groove may be V-shaped as shown in FIG. 9, or may be U-shaped, for example. The slit 52E does not reach the inner peripheral surface 12b of the first member 12 in the radial direction. The second resin of the second member 13 is interposed in the slit 52E. By interposing the second resin in the slit 52E, the first member 12 and the second member 13 are engaged in the slit 52E, so that the joint strength between the first member 12 and the second member 13 is increased.

The piping structure of the fifth embodiment is a joint provided with the first member 12E instead of the first member 12A, and a resin pipe 4 similar to the piping structure 70 is fitted into each receiving port of the joint. ..

The joint manufacturing method of the fifth embodiment includes the same steps as the joint manufacturing method of the first embodiment. In the present embodiment, in the first member mounting step, the side ends 51p and 51q of the cut portion 51 of the first member 12 are separated from each other while the side ends 52x and 52y on the radial outer side of the slit 52E are brought close to each other. 1 The member 12 is opened wide and fitted into the core 100 of the mold (see FIG. 4).

In the joint of the fifth embodiment described above, the slit 52E is formed in the first member 12, and the second resin of the second member 13 is interposed in the slit 52E. By interposing the second resin in the slit 52E, the first member 12 and the second member 13 are engaged with each other in the slit 52E, and the joint strength between the first member 12 and the second member 13 is increased.

According to the piping structure of the fifth embodiment, the same effect as that of the piping structure of the first embodiment can be obtained.

According to the joint manufacturing method of the fifth embodiment, the same effect as that of the joint manufacturing method of the first embodiment can be obtained. Further, in the first member mounting step, it is necessary to expand the cutting portion 51 in order to fit the first member 12 into the core 100 of the mold, but the slit 52E is formed so that the cutting portion 51 can be smoothly formed. It can be expanded more widely, and the first member 12 can be easily attached to the core 100 of the mold.

(Sixth Embodiment)
Next, the joint, the piping structure, and the method of manufacturing the joint according to the fifth embodiment to which the present invention is applied will be described.

In the joint 1F of the sixth embodiment, as shown in FIGS. 10 and 11, the socket 3 of the joint 10 has a two-layer structure, and the main body 2 has a single-layer structure. In the present embodiment, for the purpose of increasing the transparency of the socket 3 and imparting fire resistance to the joint 1, for example, PVC, MABS resin, MBS resin, which have excellent transparency and are easy to mold, are used as the first resin. It is preferable to use an acrylic resin or a PMMA resin. Further, as the second resin, for example, a resin such as polyvinyl chloride resin (PVC) or chlorinated polyvinyl chloride resin (CPVC) having excellent fire resistance, and heat-expandable graphite, aluminum hydroxide, magnesium hydroxide and the like are used. It is preferable to use a mixed resin containing a fire resistant agent or a flame retardant.

The outer peripheral surface 12a of the first member 12F is formed with a plurality of convex portions 35 that protrude outward in the radial direction from the outer peripheral surface 12a and are exposed on the outer surface of the second member 13. Since the convex portion 35 is made of transparent PVC (that is, the first resin), it functions as a window portion that makes the inside of the receiving port 3 visible. Further, the first member 12F of the receiving port 3 of the present embodiment is formed with a cutting portion 51 having widths W51 and W52 and slits 52A and 52B as in the fourth embodiment.

In the piping structure of the fifth embodiment, the above-mentioned joint 1F and the resin pipe 4 similar to the piping structure 70 are fitted into the respective receiving ports of the joint.

In the joint of the sixth embodiment described above, the slits 52A and 52B have a width W52, and the second resin of the second member 13 is interposed in the slits 52A and 52B. By interposing the second resin in the slits 52A and 52B, the first member 12F and the second member 13 are engaged with each other in the slits 52A and 52B, and the joint strength between the first member 12F and the second member 13 is increased. In the joint of the sixth embodiment, since the convex portion 35 is formed on the first member 12F, the convex portion 35 and the second member 13 are engaged with each other, and the joint strength between the first member 12F and the second member 13 is increased. Further increase.

According to the method for manufacturing the pipe structure and the joint according to the sixth embodiment, the same effect as the method for manufacturing the pipe structure and the joint according to the third embodiment can be obtained.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various aspects of the present invention are described within the scope of the claims. It can be transformed and changed.

For example, in the above-described embodiment, a joint 1 having fire resistance and a transparent socket 1 (that is, a fire-resistant joint) is assumed, CPVC is mentioned as the first resin, and transparent PVC is mentioned as the second resin. However, the first resin and the second resin are not limited to the above-mentioned resins. As described above, the first resin and the second resin are appropriately selected according to the function to be imparted to the joint 1. For example, if a resin to which an inorganic material or a metal powder is added is used as the first resin forming the inner layer of the main body, and the above-mentioned transparent PVC is used as the second resin forming the outer layer of the main body and the entire socket, the sound insulation is excellent. Moreover, a joint having a transparent socket (that is, a sound insulating joint) can be realized. Further, if a heat-resistant resin such as CPVC is used as the first resin forming the inner layer of the receiving port and a polypropylene (PP) resin is used as the second resin forming the outer layer and the main body of the receiving port, the transparency is excellent and the receiving port is made. It is possible to realize a joint having chemical resistance (that is, a joint for high temperature drainage).

Further, for the purpose of increasing the degree of freedom of deformation of the first member 12 described above, a plurality of slits 52A and 52B may be formed at positions different from the cutting portion 51 in the circumferential direction of the first member 12 and at positions different from each other. .. If the degree of freedom of deformation of the first member 12 can be secured, only one of the slits 52A and 52B may be formed. Further, if the degree of freedom of deformation of the first member 12 can be secured by separating the side ends 51p and 51q of the cutting portion 51 from each other, the slits 52A and 52B need not be formed.
Further, when the receiving port 3 has a two-layer structure as in the sixth embodiment, when it is desired to give the receiving port 3 an arbitrary function other than making the receiving port 3 transparent, the convex portion 35 is omitted. May be good.

Further, in the above-described embodiment, a so-called cheese joint has been illustrated as a joint 1 having three openings 5, but the joint according to the present invention is not limited to the cheese joint, and the main body made of a straight pipe and the joint. It may be a joint having openings at both ends of the main body, a so-called elbow joint, an LT type joint (see Patent Document 1 or the like), a YT type joint, or the like, and includes all joints having a plurality of openings.

1 ... Joint 2 ... Main body 3 ... Receptacle 4 ... Resin tube 5 ... Opening 12 ... First member 13 ... Second member 51 ... Cutting portions 52A, 52B ... Slit M13 ... Second resin W51 ... Width

Claims (5)

A body that is tubular and has multiple openings,
The sockets provided in the plurality of openings are provided.
The socket has a two-layer structure, and the main body has a single-layer structure.
The inner layer of the socket has a tubular first member formed of the first resin.
The outer layer of the socket and the main body have a second member made of a second resin different from the first resin.
The first member and the second member are integrally formed.
A joint characterized in that a cut portion along the axial direction is formed in the first member. A body that is tubular and has multiple openings,
The sockets provided in the plurality of openings are provided.
The main body has a two-layer structure, and the socket has a single-layer structure.
The inner layer of the main body has a tubular first member formed of the first resin.
The outer layer of the main body and the socket have a second member made of a second resin different from the first resin.
The first member and the second member are integrally formed.
A joint characterized in that a cut portion along the axial direction is formed in the first member. The cut portion has a predetermined width in the circumferential direction of the first member, and has a predetermined width.
The joint according to claim 1 or 2 , wherein the second resin is interposed in the cut portion. A slit is formed in the first member at a position different from that of the cut portion in the circumferential direction.
The joint according to any one of claims 1 to 3, wherein the slit is formed along the axial direction of the first member. The method for manufacturing a joint according to any one of claims 1 to 4.
A first member forming step of forming the first member and forming the cut portion along the axial direction of the first member.
The first member mounting step of mounting the first member on the mold, and
A second member molding step of injecting the second resin around the first member and molding the second member integrally with the first member.
A method of manufacturing a joint, which comprises.

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