JPH1134110A - Core for producing welding joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perfectly automate a series of elbow type electric welding joint manufacturing processes by easily and properly winding an electric heating wire around the outer peripheral surface of a core. SOLUTION: This core consists of a first core 10 having a protruding connection member 11 and a second core 20 having a recessed connection member 21 and the protruding connection member 11 has a connection member 13 having a columnar part and a prismatic part 13 and the holding member 14 allowing the prismatic part of the connection member 13 to protrude from the connection surface A of the first core 10 to hold the columnar part in the first core 10 in a revolvable manner and the recessed connection member 21 has the prismatic groove part 25 enabling the insertion of the prismatic part and a holding means for elastically holding the prismatic part inserted in the prismatic groove part 25 and, in the connection state wherein the prismatic part is inserted into the prismatic groove part 25, both cores 10, 20 are revolved between a molding position where the molding angle is a predetermined value and a winding position where the cores are arranged in line in such a state that the connection surfaces of both cores are in a contact state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core for manufacturing a welded joint, and more particularly, to a structure of a split core used when injection-molding an elbow type electric welded joint.

[0002]

2. Description of the Related Art As a joint for connecting a synthetic resin gas pipe or a water supply / hot water supply pipe, an electric fusion joint in which a heating wire is embedded in an inner peripheral surface of a receiving port is widely used. The production of this fusion joint is generally performed by setting a core having a heating wire wound on the outer peripheral surface in a mold and performing injection molding, and in order to remove the core from the joint after molding. It is formed so that it can be divided at the center.

A method of winding a heating wire around a core for manufacturing an elbow used in a bent portion of a pipeline is described in, for example, Japanese Patent Application Laid-Open No. 63-71323. And a method of winding a heating wire in a state where the heating wires are connected, and as described in JP-A-4-1859593, a heating wire is separately wound around each core, and then both cores are connected. There is a method of connecting a heating wire.

[0004]

However, in the case where the heating wire is wound in a state where both cores are connected, the rotation axis of the core must be changed in the course of winding, and the rotation of the core is also reduced. Since it is not stable, the working efficiency is poor, and it is difficult to wind the heating wire at a constant pitch, and it is necessary to use a device having a special structure for winding the heating wire. On the other hand, in the case where the heating wire is wound around each of the divided cores and then connected to both cores, the connection portion of the heating wire is easily loosened and automation is difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a welded joint manufacturing core which can easily and reliably wind a heating wire and which can fully automate a series of elbow-type electrowelded joint manufacturing steps. .

[0006]

In order to achieve the above object, a core for manufacturing a welded joint according to the present invention is a core for manufacturing a welded joint used when injection-molding an elbow-type electric welded joint. A first core having a convex coupling member;
A second having a concave coupling member engaging the convex coupling member;
The convex coupling member of the first core is formed by coupling with a core, the coupling member having a columnar portion and a prismatic portion, and the columnar portion of the coupling member projecting from the coupling surface of the first core. A holding member for rotatably holding the portion in the first core, wherein the concave coupling member of the second core comprises a square groove in which the prism can be fitted, and a prism fitted in the square groove. And holding means for holding the first core and the second core in a state where the first core and the second core are fitted in the square grooves.
While the first core and the second core are in contact with each other, the two cores are relatively rotatable between a molding position where the two cores have a predetermined molding angle and a winding position where both the cores are linear. It is characterized by being formed.

[0007]

FIG. 1 is a cross-sectional view showing one embodiment of a core for manufacturing a welded joint according to the present invention, FIG. 2 is a cross-sectional view showing a joint portion between both cores, and FIG. FIG. 4 is a partial cross-sectional front view of a concave engaging portion, FIG. 5 is a cross-sectional view showing a winding position where both cores are linear, and FIG. 6 is a state in which a heating wire is wound. FIG. 7 is a cross-sectional view showing a state in which both cores after the heating of the heating wire are turned to a molding position at a predetermined molding angle, and FIG. 8 is a diagram illustrating a state where the first core is removed from the joint after molding. FIG. 9 is a cross-sectional view showing a state in which both cores are drawn out of the joint.

First, the core for manufacturing a welded joint shown in this embodiment is for manufacturing a 45-degree elbow, and connects the first core 10 and the second core 20 divided at the center of the bent portion. By doing so, a core having a predetermined shape is formed. The coupling surface A between the first core 10 and the second core 20 is formed at an angle of 22.5 degrees with respect to the axis of each core.

At the center of the joint surface between the cores 10 and 20, square storage holes 12 and 22 for holding a convex coupling member 11 and a concave coupling member 21 for coupling the cores 10 and 20, respectively. Is provided.

As shown in FIG. 2 and FIG.
The convex coupling member 11 provided on the core 10 has a cylindrical portion 13.
a, a connecting member 13 having a prismatic portion 13b and a retaining flange 13c, and a cylindrical portion 13a such that the prismatic portion 13b of the connecting member 13 protrudes from the coupling surface of the first core 10.
Holding member 14 having a cylindrical portion 14a for rotatably holding the inside of the first core 10 and an engaging step 14b of the retaining flange 13c, and a locking hole provided in a cylindrical portion 13a in the holding member 14. 15, two ball plungers 16 which are resiliently engaged with each other and held at a predetermined rotation position;
1 are formed by two ball plungers 17 which are resiliently locked in locking holes 23 (see FIG. 4) provided in the first and second cores 10 and 20 to hold the cores 10 and 20 at a predetermined rotation position. The convex coupling member 11 is held and fixed in the storage hole 12 of the first core 10 by a bolt 18.

The position of the cylindrical portion 13a of the connecting member 13;
That is, the position of the cylindrical portion 14a of the holding member 14 that rotatably holds the cylindrical portion 13a is set such that the axis of the cylindrical portion 14a intersects with the axis of the first core 10 at the position of the coupling surface A. ing. That is, on the coupling surface A, the axis of the first core 10, the axis of the second core 20, and the cylindrical portion 14a
Axis intersects at one point.

As shown in FIG. 1, the prism 13b is formed with an inclined surface 13d which is parallel to the axis of the first core 10 at the time of molding. Is provided with a locking hole 19 for locking the ball plunger 24 (refer to FIG. 4) provided in the hole. Further, a concave groove 12 a into which one of the screws 16 s of the ball plunger 16 enters is provided on one side surface of the storage hole 12.

On the other hand, as shown in an enlarged manner in FIGS. 2 and 4, the concave coupling member 21 provided on the second core 20 has a square groove 25 into which the prism 13b of the connecting member 13 can be fitted.
And the ball plunger 24 which is a holding means for holding the prism portion 13b fitted in the square groove portion 25 by elastic force. The coupling surface of the concave coupling member 21 includes the convex coupling member. The locking holes 23 for locking the eleven ball plungers 17 are provided. Also, the concave coupling member 21
Is divided into two members, a groove forming material 21a and a lid member 21b, for the sake of forming the square groove portion 25, and is held and fixed in the storage hole 22 of the second core 20 by bolts 26.

As is well known, each ball plunger is provided with a ball, a coil spring, and a screw at least in a through hole formed with a female screw on the base side.
The ball is made to project by a predetermined amount with a predetermined projection force from a small hole at the front end of the through hole by the elastic force of the coil spring.

When the convex coupling member 11 and the concave coupling member 21 having the above-described structure are coupled to each other, the prism 13 b projecting from the coupling surface A of the first core 10 is connected to the second core 20.
When the ball 24a of the ball plunger 24 is locked in the locking hole 19, the cores 10 and 20 are held in a coupled state by the locking force of the ball plunger 24.

When one of the cores 10 and 20 is fixed and the other is rotated in this connected state, the cylindrical portion 1 of the holding member 14 is rotated.
4a and the cylindrical portion 13a of the connecting member 13 are relatively rotated, and the cores 10 and 20 are relatively rotated while the prism 13b of the connecting member 13 is still coupled to the square groove 25. Can be.

The ball 1 of the ball plunger 16
6a is the locking hole 15 and the ball 1 of the ball plunger 17
7a is locked in the locking holes 23, so that the relative rotation positions of the cores 10 and 20 are maintained. As shown in FIGS. 1 and 2, the cores 10 and 20 are locked. 5 is held at a molding position where the axis is at a predetermined molding angle (45 degrees), and as shown in FIG. 5, a winding position where the axes of both cores 10 and 20 are linear.

Therefore, the operation of winding the heating wire around the core of the straight pipe type electric welding joint is performed by winding the heating wire while holding the cores 10 and 20 at the winding positions shown in FIG. The heating wire can be wound in almost the same operation. However, as shown in FIG.
After winding the heating wire, it is necessary to provide a margin 31 for rotating the cores 10 and 20 to the molding position. By providing an appropriate spacer in the center of the core, the extra portion 31 can easily and reliably form the extra portion 31 having a predetermined length, as shown in FIG.
When the cores 10 and 20 are rotated to the molding position, the margin 31 can be brought into close contact with the outer peripheral surface of the core, and the heating wire 3
Zero slack can be eliminated. The heating wire winding portions at both ends of the core to be welded portions are heated at an appropriate position in the circumferential direction at the time when a predetermined winding process is completed (the state of FIG. 6) and are adjacent to each other, as in the related art. Since the coating layers of the heating wires 30 are welded to each other and fixed, the wound state is not impaired even if the extra portion 31 is provided, and the rotation of the cores 10 and 20 can be performed without any problem.

After the heating wire is wound as described above and both cores 10 and 20 are rotated to a predetermined molding position,
Is set in the mold 32 as shown in FIG.
Inject resin into 3 to form an electrical welded joint.

First, as shown in FIG. 8, the core is removed from the joint 34 after the molding. At this time, the inclined surface 13d of the prism 13b is in the first position.
Since it is parallel to the axis of the core 10, the first core 10
By pulling the ball plunger 2 in the axial direction.
4 is disengaged from the locking hole 19, and the prism 13b is
With the movement of 0, the second core 20 is extracted from the inside of the square groove 25.

The second core 20 after removing the first core 10
As shown in FIG. 9, by extracting both cores 10 and 20, an elbow-type electric welded joint 34 having a predetermined shape is obtained.

As described above, also in the core for manufacturing the elbow-type electric welding joint, the heating wire can be wound with the core in a straight state, so that the winding device similar to the straight pipe type can be easily and reliably provided. The heating wire can be wound around. Further, since it is only necessary to relatively rotate one core by 180 degrees before setting it in the mold, the heating of the core, the winding of the heating wire, the rotation of the core, the setting in the mold, and the molding. Complete automation of a series of manufacturing processes up to extraction from the product can be easily performed, and the productivity and quality of the elbow-type electrowelded joint can be improved.

In this embodiment, the case of a 45-degree elbow has been described as an example. However, the present invention can be similarly applied to other angles.

[0024]

As described above, according to the core for manufacturing a welded joint according to the present invention, the heating wire can be wound around the outer peripheral surface of the core easily and reliably because the heating wire can be wound with the core being straight. It can be rotated, and the welding joint manufacturing process can be fully automated, improving productivity and quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a welded joint manufacturing core showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a joint between both cores.

FIG. 3 is a partial cross-sectional front view of a convex engaging portion.

FIG. 4 is a partial cross-sectional front view of a concave engaging portion.

FIG. 5 is a sectional view showing a state of a winding position where both cores are linear.

FIG. 6 is a front view showing a state where a heating wire is wound.

FIG. 7 is a cross-sectional view showing a state where both cores after the heating wire are turned to a molding position at a predetermined molding angle.

FIG. 8 is a cross-sectional view showing a state in which a first core is extracted from the inside of the formed joint.

FIG. 9 is a cross-sectional view showing a state where both cores are pulled out of the joint.

[Explanation of symbols]

10: first core, 11: convex coupling member, 12: storage hole,
12a: concave groove, 13: connecting member, 13a: cylindrical portion, 13
b: prismatic portion, 13c: retaining flange, 13d: inclined surface, 14: holding member, 14a: cylindrical portion, 14b: engaging step, 15: locking hole, 16, 17: ball plunger, 1
8 bolt, 19 locking hole, 20 second core, 21 concave coupling member, 21a groove forming material, 21b lid member, 22
... storage holes, 23 ... locking holes, 24 ... ball plungers, 2
5: square groove, 26: bolt, A: coupling surface

Claims (1)

[Claims] 1. A welding joint manufacturing core used when injection-molding an elbow type electric welding joint, wherein the core is engaged with a first core having a convex coupling member and the convex coupling member. The convex coupling member of the first core is formed by coupling with a second core having a concave coupling member, the coupling member having a cylindrical portion and a prism portion, and the prism portion of the coupling member is formed of the first core. A holding member for rotatably holding the column portion within the first core so as to protrude from the connection surface, wherein the concave connection member of the second core includes a square groove portion into which the prism portion can be fitted; Holding means for holding the prism portion fitted in the square groove portion by resilient force, wherein the first core and the second core are connected to each other when the first core and the second core have the prism portion fitted in the square groove portion. A molding position where both cores are at a predetermined molding angle while the two cores are in contact with the bonding surface; A core for manufacturing a welded joint, wherein both cores are formed so as to be rotatable relative to a linear winding position.