JP3212417B2 - Method of winding wire for fusion joint and wire for fusion joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire for a fusion joint used for connecting a gas pipe or a water pipe made of a thermoplastic resin, and a wire wound around a mandrel for forming a fusion joint. It relates to a winding method.

[0002]

2. Description of the Related Art After a wire is spirally wound around a mandrel, a thermoplastic resin is injection-molded on the outer periphery of the mandrel to form a main body. The fusion joint is made of a gas pipe or a water pipe made of a thermoplastic resin. It is often used for connection (see JP-A-4-59319).

[0003] By the way, conventionally, the wire used in the fusion joint is a metal wire such as copper or nickel alloy,
Generally, it is formed by coating with a substantially concentric resin. However, when a wire having a circular cross section is used, a streak-like depression formed between the wires also appears on the inner peripheral surface of the fusion joint. Therefore, when the inner peripheral surface of the fusion joint is fused to the outer peripheral surface of a gas pipe, a water pipe or the like, earth and sand enter between the recessed portion of the joint and the outer peripheral surface of the gas pipe, a water pipe, or the like. May interfere with wearing.

[0004] In order to solve this problem, in recent years, a semi-cylindrical wire is used in which a flat surface is continuously provided in the longitudinal direction on the surface of a resin layer covering a metal wire, and the flat wire is fused. By configuring the inner surface of the joint, the inner surface of the joint is made to be a smooth surface (actually open flat 4-6).
No. 2496).

[0005]

However, when a wire having a semi-cylindrical shape is used, when the wire is twisted before the wire is supplied to the mandrel, the flat surface of the wire faces the mandrel in various directions. In such a case, there is a problem that a streak-like dent appears on the inner surface of the fusion joint in some cases.

In view of the above, the present invention focuses on the above-described problems, and when winding a wire around a mandrel, the winding of the wire for a fusion joint can ensure that the flat surface provided on the wire abuts the outer peripheral surface of the mandrel. It is an object of the present invention to provide a wire method and a wire for a fusion joint.

[0007]

According to a first aspect of the present invention, there is provided a method of winding a wire for a fusion joint according to the first aspect of the present invention, wherein a plane is formed in a longitudinal direction on a surface of a resin layer covering a metal wire. In a winding method in which a continuously provided wire is wound in a state where a flat surface is in contact with a mandrel,
The wire is wound around a mandrel after being inserted into a through hole that is inserted only in a predetermined direction.

According to another aspect of the present invention, there is provided a wire for a fusion joint according to a second aspect of the present invention, wherein the wire for a fusion joint is spirally incorporated into an inner peripheral portion of the fusion joint. And a resin layer covering the metal wire, and a concave or convex engaging portion is continuously provided in the longitudinal direction on the surface of the resin layer, and at a position separated from the engaging portion. The plane is provided continuously in the longitudinal direction.

[0009]

In the method for winding a wire for a fusion joint according to the first aspect, the twist is corrected when the wire is inserted through a through hole that is inserted only in a fixed direction. Wound around the mandrel.

When winding the wire for a fusion joint according to claim 2 around a mandrel, a guide portion engageable with an engaging portion provided on the surface of the resin layer is provided in a fixed state, and the wire is attached to the guide portion. After the engaging portion is engaged with the guide portion, it is wound around the mandrel. By doing so, the wire can be wound around the mandrel after the twist of the wire is corrected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment corresponding to the method for winding a wire for a fusion joint according to claim 1 will be described with reference to FIGS.

FIG. 1 is a perspective view showing a state in which a wire is wound around a mandrel, in which 1 is a wire, 2 is a mandrel, 3 is a tension adjusting device, and 4 is a twist correcting jig.

The wire 1 is drawn out of a bobbin 5. As shown in FIG. 3, the wire 1 is composed of a metal wire 11 having a circular cross section and a resin layer 12 having a kamaboko-shaped cross section that covers the surface thereof. The plane 13 is continuous in the longitudinal direction. For the metal wire 11, for example, a wire for general resistance such as a nichrome wire, a copper-nickel alloy wire, a manganese-nickel alloy wire, a chromel wire, and an iron-chrome wire can be used. And thermoplastic resins such as polyethylene resin, polypropylene resin, polyvinyl chloride resin and polybutene resin.

The mandrel 2 serves as an inner mold for forming the body of the fusion joint. The mandrel 2 is connected to a rotating shaft 21 so that the wire 1 can be wound by its own rotation. ing.

The tension adjusting device 3 includes the mandrel 2.
And the bobbin 5. This tension adjusting device 3
Has a first drum 31 whose rotational pressure can be adjusted, a second drum 32 and a third drum 33 that are rotatable, and a force exceeding the rotational pressure of the first drum 31 from the mandrel 2 side. When the wire 1 is pulled, all the drums 31, 32, 33 rotate in the direction in which the wire 1 is sent out. In addition, the tension adjusting device 3 disposes the second drum 32 in a position diagonally below and to the right of the first drum 31 and positions the third drum 33 in a position diagonally below and to the left of the first drum 31. Thereby, the distance along which the wire 1 extends along the outer periphery of the first drum 31 is ensured.

The twist correcting jig 4 is provided between the tension adjusting device 3 and the mandrel 2, and is fixed to the tension adjusting device 3 via a support member 6. As shown in FIG. 2, the twist correcting jig 4 has six flat surfaces 41a, 41b, 41c, 41d, 41 circumscribing the wire 1.
e, 41f, and the wire 1 is inserted into the through hole 41 only in a direction in which the plane 13 corresponding to the bottom of the semicylindrical shape comes into contact with the outer peripheral surface of the mandrel 2.
Not to be inserted. That is, as shown in the figure, when the wire is installed so as to contact the outer peripheral surface of the mandrel with the plane of the wire facing downward, the plane 13 of the wire 1 faces sideways before the twist correcting jig 4. Even when the wire 1 is twisted upward, when the wire 1 passes through the through hole 41 of the twist correcting jig 4, the twist of the wire 1 is always corrected so that the plane 13 faces downward.

When winding the wire 1 around the mandrel 2, the first drum 3 provided in the tension adjusting device 3
The rotation pressure of 1 is appropriately set according to the wire diameter of the wire 1 and the diameter of the mandrel 2, and then the mandrel 2 is rotated in a direction in which the wire 1 is wound. Then,
The wire 1 pulled out from the bobbin 5 passes through the tension adjusting device 3, then also passes through the through hole 41 of the twist correcting jig 4, and is then wound up on the mandrel 2. That is,
Since the wire 1 can be wound around the mandrel 2 after the twist of the wire 1 is corrected by the twist correcting jig 4, the flat surface 13 provided on the wire 1 must be always brought into contact with the outer peripheral surface of the mandrel 2 and wound. Can be.

Therefore, the twist correcting jig 4 is preferably provided as close to the mandrel 2 as possible in order to prevent the wire 1 from twisting between the twist correcting jig 4 and the mandrel 2.

Next, an embodiment corresponding to the wire for a fusion joint according to claim 2 will be described with reference to FIG.

FIG. 4 is a sectional view showing a wire for a fusion joint according to the present embodiment. In the wire 7 according to the present embodiment, a resin layer 72 covering the surface of a metal wire 71 has a longitudinally extending upper surface. It is formed in a semi-cylindrical section having a continuous concave engaging portion 73, and a portion corresponding to the bottom of the semi-cylindrical portion is a plane 74 that is continuous in the longitudinal direction.

When the wire 7 of the present embodiment is wound around a mandrel, the wire 7 can be inserted into an insertion hole of a torsion correcting jig shown below, so that the wire winding method according to claim 1 can be applied. it can.

Hereinafter, the twist correcting jig 8 will be described with reference to FIG. The details of the other winding methods are the same as those of the winding method shown in the first embodiment, and a description thereof will be omitted.

The twist correcting jig 8 includes a concave engaging portion 73 of the wire 7 on one side of a rectangle circumscribing the wire 7 at four places.
A through-hole 82 having a cross-sectional shape provided with a convex guide portion 81 that engages with the wire 7 is formed.
Is not engaged with the convex guide portion 81, the through hole 8
2 is not inserted. In other words, even if the plane 74 of the wire 7 is twisted in front of the torsion correction jig 8 such that the plane 74 faces sideways or upwards, when passing through the through hole 81 of the torsion correction jig 8, the plane 74 must be downward. The twist of the wire 7 can be corrected so as to face the wire.

Although FIG. 5 shows the torsion correcting jig in which the through hole is formed by one part, for example, as shown in FIG. 6, the through hole 82 is formed by the upper member 8a and the lower member 8b.
And a twist correcting jig 8B having a through hole 82 formed by an upper member 8c and a lower member 8d, and left and right horizontal members 8e and 8f as shown in FIG. May be used. Incidentally, the torsion correcting jig 8 in which the through-hole 82 is formed by a plurality of members as described above.
In A and 8B, the size of the through hole 82 can be finely adjusted according to the degree of tightening between the members. Or adjust the tension required to do so. Also, as shown in FIG.
You may use the torsion correction jig 8C in which 2a is formed in the shape matched with the cross-sectional shape of the wire 7. FIG.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. Are also included in the present invention.

For example, in the method of winding a wire for a fusion joint, any number of twist correcting jigs may be provided between the tension adjusting mechanism and the mandrel.

On the other hand, in the embodiment of the fusion joint wire,
Although the resin layer has shown a wire having a semi-cylindrical cross section, the cross-sectional shape of the resin layer is not limited to the semi-cylindrical shape. , 2 above the rectangle as shown in FIG.
The same effect can be obtained with the wire 7B in which the metal wire 71 is covered with the resin layer 72b having a cross-sectional shape whose corner has been cut off.

In the embodiment of the fusion joint wire,
Although the wire in which the concave engaging portion is provided on the resin layer is shown, as shown in FIG. 11, the convex engaging portion 7 is provided on the resin layer 72c.
The same effect can be obtained with the wire 7C provided with the wire 5. However, in that case, wire 7C
When winding the wire around the mandrel, it is necessary to use a twist correcting jig (not shown) having a concave guide portion.

Further, in the embodiment of the wire for the fusion joint,
Although the wire in which one engagement portion is formed on the upper surface of the resin layer is shown, the position and the number of the engagement portions are not limited to the embodiment, and for example, as shown in FIG. 73
As shown in FIG. 13, a wire 7D in which two wires are provided in parallel on the upper surface, a wire 7E in which one concave engagement portion 73 is provided on each side surface, and as shown in FIG. The concave engaging portion 73 has one on each of the upper surface and both side surfaces.
The same effect can be obtained with the wires 7F provided one by one. However, in this case, when winding the wire around the mandrel, it is necessary to use a twist correcting jig (not shown) in which a convex guide portion is formed at a position corresponding to the concave engagement portion.

[0030]

As described above, in the method for winding a wire for a fusion joint according to the first aspect of the present invention and the wire for a fusion joint according to the second aspect, the twist of the wire is corrected. After that, the wire can be wound around the mandrel, so that an effect can be obtained that the plane provided on the wire can always be brought into contact with the outer peripheral surface of the mandrel and wound.

[Brief description of the drawings]

FIG. 1 is an overall perspective view for explaining an embodiment corresponding to the method for winding a wire for a fusion joint according to the first embodiment.

FIG. 2 is a front view of a twist correcting jig used in the winding method.

FIG. 3 is a sectional view of a wire used in the winding method.

FIG. 4 is a sectional view of an embodiment corresponding to the wire for a fusion joint according to the second embodiment.

FIG. 5 is a front view showing a twist correcting jig that can be used when winding the wire.

FIG. 6 is a front view showing a modification of the twist correcting jig.

FIG. 7 is a front view showing a modification of the twist correcting jig.

FIG. 8 is a front view showing a modification of the twist correcting jig.

FIG. 9 is a cross-sectional view showing a modification of the fusion joint wire.

FIG. 10 is a sectional view showing a modified example of the fusion joint wire.

FIG. 11 is a sectional view showing a modified example of the fusion joint wire.

FIG. 12 is a sectional view showing a modified example of the fusion joint wire.

FIG. 13 is a sectional view showing a modification of the fusion joint wire.

FIG. 14 is a sectional view showing a modified example of the fusion joint wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 wire 11 metal wire 12 resin layer 13 plane 2 mandrel 4 twist correction jig 41 through hole 7 wire 71 metal wire 72 resin layer 73 concave engagement part 74 plane 8 twist correction jig 81 convex guide part 82 through hole

Claims (2)

(57) [Claims] 1. A winding method of winding a wire having a plane continuously provided in a longitudinal direction on a surface of a resin layer covering a metal wire in a state where the plane is in contact with a mandrel, A method for winding a wire for a fusion joint, wherein the wire is wound around a mandrel after being inserted through a through hole inserted only in a predetermined direction. 2. A wire for a fusion joint which is spirally incorporated into an inner peripheral portion of the fusion joint, wherein the wire is formed of a metal wire and a resin layer covering the metal wire, and a concave surface is formed on a surface of the resin layer. Alternatively, for a fusion joint, a convex engaging portion is continuously provided in the longitudinal direction, and a plane is continuously provided in the longitudinal direction at a position separated from the engaging portion. wire.