JPH06254898A - Production of electric fusing joint - Google Patents

Abstract

PURPOSE:To efficiently and certainly perform a winding process adapted to a core in order to mold an elbow type electric fusing joint. CONSTITUTION:The bent part of a core 1 is supported by a support shaft 2 provided in a direction wherein both exial lines (X-axis, Y-axis) cross each other at a right angle. The axial line X of the first core 1a is arranged on a rotary axial line R to rotate the core 1a and an electric heating wire 14 is wound around the core 1a from the end part thereof to the bent part. Next, the electric heating wire is passed through the bent part while the core 1 is revolved around a Z-axis to be wound around the second core 1b. The axial line Y of the second core 1b is arranged on the rotary axial line R to reversely rotate the core 1b and the electric heating wire is wound around the core 1b from the bent part to the end part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electric fusion joint, and more particularly to a method for manufacturing an electric fusion joint in which a coil-shaped heating wire is arranged on the inner peripheral surfaces of both ends of an elbow.

[0002]

2. Description of the Related Art As one of the pipe joints used for connecting plastic pipes used for gas pipes and water and sewer pipes,
An electric fusion joint (electro fusion joint: EF joint) is known. This electrofusion joint is a resin molded product in which a coil-shaped electrothermal material (heating wire) is arranged on the inner peripheral surface of the joint, and the plastic pipe is connected to the outside of the joint after fitting the pipe from both sides of the joint. It is carried out by connecting a power source to the exposed terminal pin (terminal) and energizing a heating wire to heat and melt the contact surface between the inner surface of the joint and the pipe.

Conventionally, various methods have been proposed as a method for manufacturing this electric fusion joint, but generally, a core having an inner peripheral molding surface for forming the inner peripheral surface of the joint main body is used. A winding process of winding a heating wire into a coil a required number of times on the outer peripheral surface, and a terminal treatment for inserting and connecting terminal pins by aligning both ends of the heating wire and electrically connecting the terminal pin and the heating wire. A method comprising a step and a molding step of setting this in a mold (outer mold) and then injection-molding a resin is widely performed.

In such a process, when manufacturing an elbow, for example, as described in Japanese Patent Laid-Open No. 4-185993, heating wires are separately wound around the divided cores, and then the cores are joined. At the same time, a method of connecting a heating wire to obtain an electrical connection is known.

[0005]

However, as described above, in the method of winding the heating wire in the state where the core is divided and connecting the heating wire together with the joining of the cores, the winding process is divided into two. It is difficult to improve work efficiency, and since the heating wire is divided in the middle, a connection terminal for connecting this and the connection work are required, and it is difficult to expect improvement in work efficiency from this aspect as well. Furthermore, since tension is not easily applied to this connection terminal when winding the heating wire,
It is easy to imagine that during injection molding, this part cannot withstand the injection pressure, and there is a high possibility that the heating wire or the connection terminal itself will stick out to the inner surface of the joint, or problems with the stability of electrical connection will occur. It Therefore, conventionally, in many cases,
In this elbow winding process, one winding is performed by one hand by a human hand. In this way, when the winding work is performed manually, the winding tension is unstable, and the winding is performed in a line. However, there are many problems in terms of work efficiency and work efficiency, and improvements are urgently needed.

[0006] Therefore, an object of the present invention is to provide a method for manufacturing an electric fusion joint which can efficiently and surely perform a winding process on an elbow core.

[0007]

In order to achieve the above-mentioned object, a method for manufacturing an electric fusion splicing joint according to the present invention is directed to a split L-shaped split core forming an inner peripheral surface of an elbow type electric fusion splicing joint. Manufacture of an electric fusion joint in which a heating wire is wound around an outer peripheral surface, the core is placed in an outer mold, and a resin is injected into a space formed by the outer mold and the core to embed the heating wire in the resin. In the method, both axis lines (X axis, Y
The axis (X axis) of each of the split cores is arranged on one rotation axis, and the position where the two axes intersect is orthogonal to each other. While rotating the core about the axis of No. 1, the heating wire is wound around the outer peripheral surface of one core from the end toward the bent portion, and then, in a direction (Z
While rotating the core about the axial direction), the heating wire is turned to the other core side through the inside of the bent portion, and the other axis (Y-axis) of the core is arranged on the one rotation axis. The heating wire is wound around the outer peripheral surface of the other core from the bent portion toward the end while rotating the core in the direction opposite to the rotation direction about the axis of the other core.

[0008]

[Operation] According to the above configuration, after the elbow molding core is joined and the bent portion of the core is supported, the core is simply rotated in a predetermined direction, and the core is continuously electrified at a predetermined position. The hot wire can be wound, and stable winding can be reliably performed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail based on an embodiment shown in the drawings. 1 shows a core supporting device for carrying out the present invention. FIG. 1 is a front view showing a state in which one core is wound, FIG. 2 is a plan view of the same, and FIG. 3 is one core. Is a front view showing a state in which the winding is finished and the winding is transferred to the other core, FIG. 4 is a front view showing a state in which the other core is wound, and FIG. 5 is a manufactured elbow-type electric fusion It is sectional drawing of a dressing joint.

First, as shown in FIGS. 1 and 2, a core 1 for forming an inner peripheral surface of an elbow-type electric fusion joint has a first core 1a and a second core 1b at the center of a bent portion. In the state of fitting and connection in a separable manner, the intersection of the axis line X (X axis) of the first core 1a and the axis line Y (Y axis) of the second core 1b in the bent portion is mutually crossed with both axis lines X, Y. Axis Z in the orthogonal direction
It is rotatably supported by a support shaft 2 provided on (Z axis). The support shaft 2 is attached to a tip end portion of a revolving arm 6 rotatably provided on a bearing portion 5 of a support column 4 which is erected at one end of a pedestal 3, and the core 1 includes a bent portion of the core 1. It is pivotally supported on the revolving arm 6 via a box-shaped holding member 7 for holding. Further, the swivel arm 6 has a pin insertion hole 6 into which a fixing pin 8 for fixing the core 1 at a predetermined angle is inserted.
a is provided, and the holding member 7 is provided with two pin holes 7a and 7b into which the fixing pin 8 is inserted.

On the other hand, the end of the core 1 is rotatably supported by an end supporting device 9 provided at the other end of the gantry 3. The end support device 9 includes a support plate 12 rotatably and axially movable on a bearing 11 of a column 10 standing on the other end of the pedestal 3, and the support plate 12
And a lever 13 for moving the shaft in the axial direction.

The rotation axis of the revolving arm 6 and the rotation axis of the support plate 12 of the end supporting device 9 are located on the same rotation axis R, and the core 1 around which the heating wire 14 is wound.
First, the axis X of the first core 1a is set to the rotation axis R
It is set in the state matched above. That is, the fixing pin 8 is inserted into one pin hole 7a of the holding member 7 through the pin insertion hole 6a of the revolving arm 6, the bent portion of the core 1 is fixed, and the lever 13 is operated to engage the support plate 12. The pin 12a is inserted into and engaged with an engagement hole 1c formed in the end surface of the first core 1a to fix the end portion of the first core 1a. As a result, the axis X of the first core 1a becomes coaxial with the rotation axis R of the swivel arm 6 and the support plate 12, and the first core 1a is set to be rotatable around the rotation axis R.

Next, the heating wire 14 is drawn out from the nozzle of the heating wire supply portion (not shown), and the tip end portion thereof is fixed to the end portion of the first core 1a. In this state, while rotating the first core 1a in the direction of the arrow C1 shown in FIG. 1 about the X axis, the nozzle of the heating wire supply unit is moved in the direction of the bending portion, and the heating wire 14 is moved at a predetermined winding density. It is wound around the outer periphery of the first core 1a. The heating wire 14 is formed by coating the outer circumference of a nichrome wire or the like with a resin such as polyethylene or polybutene, and a terminal pin is attached to the tip portion after the resin coating is peeled off.

After the heating wire 14 has been wound up to a predetermined position, the nozzle of the heating wire supply unit is moved so that the heating wire 14 is located inside the bent portion of the core 1, and then the fixing pin 8 is pulled out. The holding member 7 is rotatable with respect to the turning arm 6, and the lever 13 is retracted to release the engagement state between the engagement pin 12a of the support plate 12 and the engagement hole 1c of the first core 1a. , The core 1 is rotated 90 degrees clockwise in FIG. 1 about the support shaft 2, that is, the Z axis, so that the axis Y of the second core 1b is coaxial with the rotation axis R. At this time, as shown in FIG. 3, the heating wire 14 passes through the inside of the bent portion of the core 1 and moves to the second core 1b side.

In order to prevent the winding from being disturbed by the rotation of the core 1 and the movement of the nozzle, the coating of the heating wire 14 is heated and melted by a heater or the like at the stage of finishing the winding of the first core 1a, The adjacent heating wires 14 are welded to each other, or the winding is fixed by using an adhesive tape or the like.

After rotating the second core 1b as described above, the fixing pin 8 is inserted into the pin hole 7b of the holding member 7 through the pin insertion hole 6a of the turning arm 6 to fix the bent portion of the core 1. The lever 13 is operated to insert and engage the engagement pin 12a of the support plate 12 into the engagement hole 1d of the second core 1b to fix the second core 1b. As a result, the second core 1
The axis b of the b is coaxial with the rotation axis R and is set to be rotatable around the rotation axis R.

Then, as shown in FIG. 4, while moving the nozzle of the heating wire supply unit to a predetermined winding start position,
While rotating the second core 1b about the Y axis in the direction opposite to that of the first core 1a, that is, in the direction of arrow C2 shown in FIG. 4, the nozzle of the heating wire supply unit is moved to the end of the second core 1b. And the heating wire 14 is wound around the outer periphery of the second core 1b at a predetermined winding density.

After the heating wire 14 has been wound around the second core 1b, in order to prevent the heating wire 14 from being separated from a predetermined position of the core 1 by the resin pressure at the time of injection molding, if necessary, in the middle of the winding. And heat the coating of the front and back parts with a heater etc.,
A predetermined work such as welding the heating wires 14 to each other and connecting terminal pins to both ends of the heating wires 14 is performed, the core 1 is detached from the core supporting device, set in an outer mold, and injection-molded.

As a result, as shown in FIG. 5, the heating wire 14 is densely wound around both ends of the pipe, and the elbow where the heating wire 14 has passed the shortest distance inside the bending portion is formed in the middle bent portion. The mold electrofusion joint 21 can be manufactured.

The first core 1 in the above winding process
The rotation of a and the second core 1b is performed by rotating the swivel arm 6 and the support plate 1.
A suitable handle may be provided on the two shafts and rotated by hand, or may be rotated by a motor.
Similarly, the rotation of the core 1 about the Z axis can be performed by any means. Further, when the core 1 is rotated about the Z axis, the nozzle of the heating wire supply unit is moved in conjunction with the rotation of the core 1 so as not to change the tension of the heating wire 14. Preferably. Furthermore, although the 90-degree elbow is illustrated in the above-mentioned embodiment, the winding can be performed by substantially the same operation even in the case of an elbow having other angles.

[0021]

As described above, according to the method for manufacturing an electric fusion joint of the present invention, the heating wire can be wound with the core integrated in the manufacturing process of the elbow type electric fusion joint. Therefore, since the winding process is not divided and the heating wire is not divided in the middle of the process, extra parts such as connection terminals are not required, and the connection work is eliminated, so that the electrical connection is stable. Further, the change in winding tension can be suppressed, quality can be improved and stabilized, work efficiency can be improved, and the manufacturing cost of the electric fusion joint can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a core supporting device for carrying out the present invention and showing a state in which one core is wound.

FIG. 2 is a plan view of the same.

FIG. 3 is a front view showing a state in which the winding on one core is finished and the winding is transferred to the other core.

FIG. 4 is a front view showing a state in which winding is performed on the other core.

FIG. 5 is a cross-sectional view of the manufactured elbow-type electric fusion joint.

[Explanation of symbols]

1 ... Core, 1a ... 1st core, 1b ... 2nd core, 2 ... Support shaft, 6 ... Swivel arm, 7 ... Holding member, 8 ... Fixing pin, 9
... Supporting device, 12 ... Supporting plate, 14 ... Heating wire

Claims (1)

[Claims] 1. A heating wire is wound around an outer peripheral surface of a substantially L-shaped split core forming an inner peripheral surface of an elbow-type electric fusion joint, and the core is arranged in an outer mold to form an outer mold and a core. In the method for manufacturing an electric fusion joint in which the heating wire is embedded in the resin by injecting the resin into the space formed by, the position where both axis lines (X axis, Y axis) intersect in the bent portion of the split core is The cores are supported from directions (Z-axis directions) orthogonal to both axes, and the axis (X-axis) of one core of the split cores is arranged on one rotation axis, and the cores are centered on the axis of the one core. While rotating, a heating wire is wound around the outer peripheral surface of one of the cores from the end toward the bent portion, and then the core is rotated about directions (Z-axis directions) orthogonal to both axes of the bent portion. While moving the heating wire through the inside of the bend to the other core side, The other axis (Y-axis) of the core is arranged on the one rotation axis, and thereafter, while rotating the core in the opposite direction to the rotation direction about the axis of the other core, the outer circumference of the other core A method for manufacturing an electric fusion splicing joint, characterized in that a heating wire is wound on a surface from a bent portion to an end portion.