JPH11118085A - Electrical welding coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical welding coupling for reliably connecting an electric heating wire to a connector pin without generating poor contact electrification, and for preventing the connector pin from slipping off from an inner or from falling. SOLUTION: This electrical welding coupling is composed of an inner 1C having hole parts 12 on both ends and a spiral groove 11 on a socket part; an electric heating wire 3 to be wound on the spiral groove 11 of the inner 1C; connector pins 5 for connecting both ends of the electric heating wire 3 and inserted and fitted into the hole parts 12 of the inner 1C; and an outer 1D formed on the outer side of the inner 1C by injection-molding. Winding grooves for winding the electric heating wire 3 are provided on the connector pins 5, and burrs 7 are provided on the lower ends of the connector pins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner structure of an electric fusion joint and a connector pin, and a joining structure of a heating wire and a connector pin.

[0002]

2. Description of the Related Art It is well known that a pipe made of a thermoplastic resin material such as polyethylene or polybutene is connected to a pipe by electrofusion. This electric fusion joint (hereinafter, referred to as a joint) includes, for example, a pipe joint body 1 obtained by integrally injection-molding an outer cylindrical member 1D called an outer with an inner cylindrical member 1C called an inner as shown in FIG. A heating wire 3 wound around a spiral groove formed in the inner 1C;
It comprises a connector pin 6 connected to both ends of the heating wire 3 and standing on the inner 1C.

[0003] A portion 1E is a connector cover for protecting the connector pins 6 and fitting the connector terminals on the controller side. In the fusion work, a pipe 11B is inserted into the joint, a connector terminal (not shown) on the controller side is connected to the connector pins 6 at both ends, and thereafter, predetermined electric energy is supplied to connect the heating wire 3 The joint and the pipe are fusion-spliced by the heat generation action.

[0004] The connection structure between the heating wire 3 and the connector pin 2 adopted by this joint is disclosed in Japanese Utility Model Publication No. 5-2095.
As shown in FIG.
Flanges 61 and 6 provided vertically below each other
2, a heating wire 3 is wound between the collars, and then the collars 61 and 62 are caulked, and a projection at the lower end of the connector pin is inserted into the hole 12 formed in the inner 1C. In addition, there is also a structure in which a heating wire is simply wound around a connector pin for connection.

[0005]

However, in the connector pin 6 of the conventional joint shown in FIG. 3, the heating wire 3 is joined to one of the connector pins, and the heating wire 3 is wound around the inner while having a certain tension. It is joined to the other connector pin. For this reason, a load is applied in a direction perpendicular to the axis of the connector pin 6, and there is a problem that the connector pin 6 comes off or sags.

In addition, caulking when connecting a heating wire to a connector pin makes it difficult to fully automate a series of manufacturing processes, and simply winding the heating wire around the connector pin tends to cause poor contact conduction. is there.

[0007] Accordingly, the present invention provides an electro-fusion joint using a connector pin having upper and lower wrapping portions and a return at a lower end portion to solve the above problem.

[0008]

Means for Solving the Problems An inner having a hole at both ends and a helical groove at a receiving portion, a heating wire wound around the helical groove of the inner, and both ends of the heating wire are connected. In an electrofusion joint comprising a connector pin inserted into a hole of an inner and an outer formed by injection molding outside the inner, the connector pin is provided with a winding groove around which the heating wire is wound, and a lower end thereof. This is an electrofusion joint provided with a return in the section. Here, it is desirable that the width of the heating wire winding groove is slightly smaller than the wire diameter of the heating wire.

As a feature of the present invention, the connector pin 6 is turned back as shown in FIG. 2 and inserted into the hole portion 12 of the inner 1C, so that the fixing is reliable, and problems such as detachment, sinking, etc. are prevented and the defect is prevented. It becomes a measure. In addition, the installation method of the connector pin is simple because it only pushes in. Therefore, there are advantages such as easy automation by mechanization and high efficiency. Optimizing the length of the lower end of the connector pin, the width of the return, and the number according to the nominal diameter of the joint will further improve the performance.

Another feature is that, at the beginning of the winding of the heating wire, the heating wire is sandwiched in the groove below the winding portion of the connector pin while applying a tensile load to the heating wire, and then the heating wire is connected to the winding portion of the connector pin. At the end of winding, the heating wire is inserted into the groove above the winding portion of the connector pin. At this time, the width of the groove is slightly smaller than the wire diameter of the heating wire,
The heating wire is inserted into the gap between the side walls of the groove and press-fitted in a tight fit, and the heating wire is locked in at least two upper and lower grooves, so that the heating wire comes off the connector pin and makes contact Eliminates the problem of poor energization.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described with reference to the drawings. FIG. 1 shows a state in which the plastic pipe 11B is connected to an electro-fusion type plastic pipe joint according to the present invention, and FIG. 2 is a sectional view showing the structure of a connector pin. The configuration of the electrofusion joint main body and the like is not different from the conventional one, so that the description is omitted.

The connector pin 5 protrudes from the outer surface of the joint body, and has an upper end 51 into which the separate power supply controller is inserted.
And a connector pin lower end portion 52 which is fitted and positioned and buried in the inner hole 12 at the lower portion, and flange-shaped flanges 53 and 54 are provided between them. Between the flanges 53 and 54, there is a winding part 55 for winding the heating wire 3 several times, and furthermore, grooves for sandwiching the heating wire 3 at both ends of the winding part 55, in this embodiment, two places, upper and lower. 56 and 57 are provided. The width of each of the grooves 56 and 57 is a dimension enough to fit the heating wire 3 or the width of the heating wire 3.
Size slightly smaller than the wire diameter of, for example, 0.0
It is formed as small as 3 mm. Therefore, if the heating wire 3 is fitted into one of the grooves, the heating wire 3 is wound around the outer peripheral surface of the winding portion 55, and then the heating wire 3 is fitted into the other groove, contact failure between the connector pin 5 and the heating wire 3 is poor. Will not occur.

Further, since the connector pin lower end 52 inserted into the hole 12 is provided with the return 7, it is assumed that a load acts in the direction perpendicular to the axis of the connector pin 6 due to the tension of the heating wire 3. Also, no problems such as falling out or falling down occur.

[0014]

According to the present invention, as described above, the problem of contact failure of the heating wire is eliminated by providing the connector pin with the groove around which the heating wire is wound and the lower end of the pin having a return. Further, the problem of the connector pin coming off from the inner during production of the electrofusion joint and causing problems such as sinking was solved, and mounting was simplified. This can improve performance and productivity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric fusion joint according to an embodiment of the present invention.

FIG. 2 is a front view of a connector pin used in the electric fusion joint of the present invention.

FIG. 3 is a cross-sectional view illustrating an example of a conventional electric fusion joint.

[Explanation of symbols]

1. Plastic fitting body, 3. Heating wire, 5. Connector pin, 6. Conventional connector pin, 7.
..The lower end of the connector pin, 9 ... the upper end of the connector pin,
12. Holes, 53, 54, flange-shaped flange, 55, heating wire winding portion, 56, 57, heating wire winding groove

Claims (1)

[Claims] 1. An inner having a hole at both ends and a helical groove at a receiving portion, a heating wire wound around the helical groove of the inner, and both ends of the heating wire connected to each other to form a hole in the inner. And an outer joint formed by injection molding outside the inner, wherein the connector pin is provided with a winding groove around which the heating wire is wound, and a return is provided at a lower end portion. An electric fusion joint characterized by being provided.