JPH0357613A - Manufacture of electrical fusion welding type synthetic resin joint - Google Patents

Abstract

PURPOSE:To remarkably improve working efficiency and obtain a joint excellent in electrical efficiency by a method wherein electrically conductive metal pattern is formed in advance on the surface of a mold, which forms the surface to fix through fusion welding of a synthetic resin joint in order to transfer electrically conductive path to the surface for the fusion welding of the joint. CONSTITUTION:The coating 11 of resist is performed onto the surface of a mold 10, which forms the surface to fix through fusion welding of a branch pipe joint 1. The coating of the resist is performed by covering the part excluding the electrically conductive metal pattern part, which makes the electrically conductive path for wire 6. Next, metal plating is conducted on the surface of a mold 10 in order to form the electrically conductive path 12 having the predetermined pattern. The plating is conducted through the predetermined plating solution E by energizing under the condition that a counter electrode is connected to the positive pole of a power source 14 and the mold 10 is connected to the negative pole of the power source. The mold 10, from which the coating 11 of the resist is removed, is assembled to a core 15 and an outer mold 16 for injection molding. When resin is poured from the nozzle 17 of the outer mold 16 for the injection molding of the branch pipe joint, the electrically conductive path 12 is transferred to the surface 5 to fix through fusion welding of the branch pipe joint 1 so as to form the hot wire 6 having the predetermined pattern.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an electrically fused synthetic resin joint. Concerning a method of forming a tract.

[Conventional technology]

BACKGROUND OF THE INVENTION Conventionally, joints have been known in which the connecting and fixing parts of synthetic resin pipes are connected and fixed by electrical fusion when connecting synthetic resin pipes, repairing defective parts, forming branch parts, and the like. To manufacture such electric fusion joints, for example sockets and elbows, a coated hot wire wound into a coil is inserted into an inner mold (core), the outer mold is closed, and resin is injection molded. Manufactured using

Furthermore, Japanese Patent Application Laid-Open No. 63-254297 discloses a method of printing conductive metal on the fusion-fixing surface of a branch pipe joint after molding, as a means of disposing a hot wire in a branch pipe joint. .

[Problem to be solved by the invention]

However, in the method of injection molding after loading the hot wire into a mold, preparations such as winding the hot wire into a coil or spiral shape before molding and loading this into the mold are troublesome, and the hot wire is wound. It was necessary to prepare jigs for reuse and holding the same. Further, the latter printing method cannot be easily performed depending on the shape of the joint, and has disadvantages such as requiring special jigs and complicated procedures.

Therefore, the present invention provides a method for manufacturing an electric fusion type synthetic resin joint that allows hot wires to be easily installed in joints of various shapes without winding the hot wire or loading it into a mold. is intended to provide.

[Means to solve the problem]

In order to achieve the above-mentioned object, the method of manufacturing an electric fusion type synthetic resin joint of the present invention is a method of manufacturing an electric fusion type synthetic resin joint that is connected and fixed by electric fusion by treasury molding. In this method, a conductive metal pattern serving as a predetermined conductive path is formed in advance on the surface of a mold for molding the fusion fixing surface of the synthetic resin joint, and when the joint is molded with the mold, It is characterized in that the conductive path is transferred to the fusion-fixed surface.

[For production]

Therefore, a hot wire consisting of a predetermined pattern of conductive paths can be formed on the fusion-fixing surface of the joint at the same time as injection molding without winding the hot wire.

[Example] Hereinafter, the present invention will be described in more detail based on a manufacturing example of a branch pipe joint shown in the drawings.

1 and 2 show a branch pipe joint manufactured according to this embodiment, with FIG. 1 being a sectional view and FIG. 2 being a bottom view. 3 to 5 show an example of the manufacturing procedure, and FIG. 3 is a sectional view showing a state in which a resist coating is applied to the surface of a mold that forms a fusion fixing surface of a branch pipe joint; FIG. 4 is a cross-sectional view showing the state in which conductive metal is plated on the surface of the mold, and FIG. 5 is a cross-sectional view of the mold for injection molding the branch pipe joint.

First, as shown in FIGS. 1 and 2, the branch pipe joint 1 manufactured in this example includes a saddle portion 3 that is fused and fixed to the outer peripheral surface of a synthetic resin pipe 2, and a saddle portion 3 that stands on the saddle portion. The inner peripheral surface of the saddle portion 4 is a welding fixing member 5 to the synthetic resin pipe 2, and a hot wire 6 for heat fusion is arranged on the welding fixing surface 5. It is set up.

The hot wire 6 has a conductive metal wire connected to a pair of terminal portions 6a and 6b spirally arranged so as to surround the opening 4a of the short tube portion 4. 6b is connected to an appropriate external terminal (not shown).

In the present invention, when manufacturing the branch pipe joint 1 having such a structure by injection molding, the hot wire 6 of the fusion fixing surface 5 is formed simultaneously with the molding of the branch pipe joint 1.

In molding the branch pipe joint 1, first, as shown in FIG. A resist layer 8L11 is applied to the surface. This resist covering 11 has m
i.

Next, as shown in FIG. 4, the surface of the mold 10 having the resist coating 11 formed thereon is plated with metal to form a predetermined pattern of conductive paths 12. This plating process can be performed in the same way as normal plating process by connecting the counter electrode 13 as an anode and the mold 10 as a cathode to the power source 14 through a predetermined plating solution E, and applying electricity. , it is not necessary to increase the adhesion with the mold 10, so it can be carried out at high current density in a short time.

The resist fill is removed from the mold 10 in which the conductive path 12 has been formed by the above-mentioned plating process, and as shown in FIG. Ru. Then, resin is injected from the nozzle 17 of the outer mold 16 and the branch pipe joint 1 is injection molded. The conductive path 12 formed on the surface of the mold 10 is transferred to the fusion fixing member 5 of the branch pipe joint 1, and a predetermined pattern of hot wires 6 is formed.

Incidentally, the composition of the conductive metal forming the hot wire 6, that is, the composition of the plating material, the material of the surface of the mold 10, etc. can be selected as appropriate. A nickel/chromium mixture that can form a conductive path can be used, and the mold surface material can be stainless steel or hard chromium, which has conductivity during plating and corrosion resistance against plating solutions, and is also suitable for resin injection molding. Plated steel or the like can be used. Furthermore, the resist is shown! Formation of ill can also be performed by various means, similar to the resist coating formation process during normal plating process.

In the above embodiment, the manufacture of branch pipe joints was explained, but when manufacturing sockets and elbows, it is also possible to form and transfer a predetermined conductive path on the inner mold for molding these, and it is possible to create various shapes. Electrofusion joints can be easily manufactured using similar procedures.

〔Effect of the invention〕

As explained above, the method for manufacturing an electrically welded synthetic resin joint of the present invention involves forming a conductive metal pattern on the surface of a mold that forms the welding and fixing surface of the joint, and applying the pattern to the injection molding surface of the joint. Since it is transferred to the fusion fixing member at the same time as the molding, the desired hot wire for heat fusion can be formed at the same time as the joint is molded.
Work efficiency can be greatly improved. Moreover, it can be easily applied to joints of various shapes. Furthermore, the joint manufactured by the method of the present invention has excellent electrical efficiency during heat fusion because the hot wire is exposed on the fusion fixing surface.

4. 711 Description of the Drawings Figures 1 and 2 show a branch pipe joint, with Figure 1 being a sectional view and Figure 2 being a bottom view. Figures 3 to 5 show an example of the manufacturing procedure. Figure 3 is a cross-sectional view showing the state in which the surface of the mold is coated with resist waves, and Figure 4 is a cross-sectional view showing the state in which the surface of the mold is coated with resist waves. A cross-sectional view showing a state in which conductive metal is plated,
FIG. 5 is a sectional view of a mold for injection molding a branch pipe joint.

1... Branch pipe joint 2... Synthetic resin pipe 5...
・Fusion fixing surface 6... Heat wire 10... Mold mold 11... Resist! II 12... Conductive path 15... Core 16... External mold East 1 solid upper branch pipe 11 most 2 factors 14 Hide 5 factors

Claims (1)

[Claims] 1. In a method of manufacturing an electric fusion type synthetic resin joint that is connected and fixed by electric fusion by injection molding, on the surface of a mold for molding the fusion fixing surface of the synthetic resin joint,
Electric fusion type synthesis characterized in that a conductive metal pattern serving as a predetermined conductive path is formed in advance, and when the joint is formed using the mold, the conductive path is transferred to the fusion fixing surface of the joint. Manufacturing method for resin joints.