JP3148019B2 - Electric 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 an electric fusion joint in which a coil which generates heat by energization is embedded in an inner peripheral surface of a resin pipe main body.

[0002]

2. Description of the Related Art In general, there is known an electric fusion joint in which a coil which generates heat by energization is buried in an inner peripheral surface of a resin tube main body, and an end of the coil is provided with an energization terminal (for example, see, for example). And JP-A-2-253098).

Conventionally, in this electric fusion joint, an energizing terminal has been projected from a predetermined position on the outer peripheral surface of a resin pipe main body.

[0004]

However, in the above-described conventional electric fusion joint, the current-carrying terminal protrudes from a predetermined position on the outer peripheral surface of the resin pipe main body. When connecting to a pipe in a place where workability is poor, the energization terminal cannot be taken out to a desired position, which causes a disadvantage that energization work becomes difficult.

[0005] In particular, in the case of an electrofusion joint in which one end is formed as a screw portion and the other end is formed as a fusion portion, the position of the energizing terminal in the fusion portion is inevitable when the screw portion is screwed into the pipe. Power supply work becomes difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an electrofusion joint which can easily carry out electricity even in a small place with poor workability. .

[0007]

An electric fusion joint according to the present invention for solving the above-mentioned problems is an electric fusion joint in which a coil which generates heat by energization is embedded in an inner peripheral surface of a resin pipe main body. Along with the circumferential direction of the resin pipe main body, there is provided an energizing terminal that is electrically connected to the end of the coil, and the energizing terminal is provided at a plurality of locations or on the entire outer peripheral surface of the resin pipe main body. It is exposed to be able to conduct across.

[0008]

According to the present invention, an energizing terminal is provided along the circumferential direction of the resin tube main body so as to conduct to the end of the coil, and the energizing terminal is connected to the outer peripheral surface of the resin tube main body. Because it is exposed so as to be able to conduct over a plurality of places or the whole, regardless of the insertion state of the electrofusion joint,
Power can be supplied to the power supply terminal from any circumferential direction.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

[0010]

Embodiment 1 FIG. 1 schematically shows the overall structure of an electrofusion joint 1.

That is, in the electric fusion joint 1, a coil 3 that generates heat by energization is buried in the inner peripheral surface of the resin pipe main body 2, and the coil 3 of the coil 3 extends along the circumferential direction of the resin pipe main body 2. A ring-shaped energizing terminal 4 that is electrically connected to the end is provided around the periphery, and the energizing terminal 4 is exposed to be conductive throughout the entire outer peripheral surface of the resin pipe main body 2.

The resin pipe main body 2 is formed in a cylindrical shape, and the ends of the resin pipe 5 can be fitted from both ends to the entire inner peripheral portion of the resin pipe main body 2. A fitting portion 21 is formed. In the vicinity of both ends of the outer peripheral surface of the resin pipe main body 2, groove portions 22 are respectively formed along the circumferential direction.
Are formed.

The coil 3 is buried on the inner peripheral wall surface side of the fitting portion 21, and its end is connected to the power supply terminal 4.

The energizing terminal 4 is formed in a ring shape and is provided in the groove 22 of the resin pipe main body 2. In this state, a part of the power supply terminal 4 is
2 is exposed on the bottom surface. This energizing terminal 4 must be made of a material that can be energized,
It should not be made of a material that generates heat when energized, such as the coil 3.

The energizing terminal 4 is not limited to the one that is exposed only on the bottom surface of the groove portion 22 as in this embodiment, but as shown in FIG. A part may be provided so as to project. Further, as shown in FIG. 3, the groove 22 may not be formed on the outer peripheral surface of the resin pipe main body 2, and the energization terminal 4 may be directly provided on the outer peripheral surface of the resin pipe main body 2. Further, the shape of the energizing terminal 4 is not limited to a circular cross-section, and as shown in FIGS. 2 and 3, the cross-section is square, semi-circular, I-shaped.
It may be formed in various shapes such as a character shape and a triangular shape.

The shape of the electric fusion joint 1 is not particularly limited, and may be, for example, an elbow joint (not shown) or a branch joint (not shown). Good. Further, as shown in FIG. 4, an electrofusion joint 1 in which a screw portion 22 is formed on an outer peripheral surface on one end side of the resin pipe main body 2 and can be screwed to various members 6 may be used. However, the screw portion 23 may be provided on the inner peripheral surface side of the resin pipe main body 2.

In the case of the electrofusion joint 1 in which the screw portion 23 is formed, the fixing position of the electrofusion joint 1 is inevitably determined in a state of being screwed to the various members 6. Since the ring-shaped energizing terminal 4 is provided around the tip of the connector, the connector 7 can be connected from any direction on the outer peripheral surface of the electrofusion joint 1 to perform the fusion work, which is particularly effective. It becomes something.

As shown in FIG. 5, for example, a connector 7 connected to the power supply terminal 4 has an insulator 71 formed so as to correspond to a part of the outer peripheral surface of the resin pipe main body 2.
In addition, the electrode 7 adapted to match the shape in the groove 22
2 provided with a substantially C-shaped cross-section and elastically deformable can be used. That is, by expanding the diameter of the connector 7 and causing the insulator 71 to extend along the outer peripheral surface of the resin pipe main body 2, the electrode 72 is fitted into the groove 22,
The electrode 72 and the terminal 4 for electric conduction can be conducted. Then, due to the elastic force of the connector 7, the conduction state between the electrode 72 and the current-carrying terminal 4 is maintained.

However, the connector 7 must have a shape corresponding to various shapes of the energizing terminal 4 as shown in FIG.

The connector 7 is, as shown in FIG.
An insulator 71 provided with two electrodes 72 may be used. In this case, it is not necessary to connect the connector 7 for each energizing terminal 4.

Further, in this embodiment, the connector 7 is elastically fitted to the outer peripheral surface of the resin pipe main body 2 to maintain the conduction state between the electrode 72 and the terminal 4 for energization. However, the present invention is not limited to this. For example, the connector 7 may be opened and closed by a hinge (not shown), and may be configured to sandwich and fix the energizing terminal 4. The electrode 72 may be formed into a shape that fits into the groove 22 or the current-carrying terminal 4 in a state where the electrode 72 is fitted in the groove 22.

[0022]

Embodiment 2 This embodiment is shown in FIGS.

That is, the electric fusion joint 1 of this embodiment is
Energizing terminal 4 of the electrofusion joint 1 of the first embodiment.
However, it is exposed to be conductive from three places on the outer peripheral surface of the resin pipe main body 2, and the other configuration is the same as that of the first embodiment. Here, only the differences will be described, and other description will be omitted. The same members as those in the first embodiment are denoted by the same reference numerals.

The energizing terminal 4 is formed in a ring shape, and has a projection 41 projecting from three equally spaced positions in the radially increasing direction.

The resin tube main body 2 has recesses 24 at three locations corresponding to the projections 41, and the projections 41 are exposed in the recesses 24.

That is, in the electric fusion joint 1, a normal socket-type connector (not shown) is inserted into a desired one of the three recesses 24, and the connector and the current-carrying terminal 4 are connected to each other. Electric conduction is enabled by making the projection 41 conductive.

In this embodiment, the projections 4 are connected to the energizing terminals 4 so that the projections 41 are exposed in the recesses 24.
1 is projected, but if the energizing terminal 4 can be exposed in a conductive manner, the projection 41
It is not necessary to form and expose
May be exposed directly. Further, an electrode (not shown) having an appropriate shape instead of the protrusion 41 may be formed on the outer surface of the energizing terminal 4 so as to expose the electrode. Further, in the present embodiment, the concave portion 24 is formed in the resin pipe main body 2 to expose the projection 41, but
As shown in FIG. 9, a protrusion 41 is formed on the outer peripheral surface of the resin pipe main body 2.
May be formed so as to directly protrude.
In this case, it is possible to conduct electricity by the connector 7 of the type shown in FIG.

As shown in FIG. 10, a conductive connecting member 42 formed in a concave shape in advance is connected to the resin pipe main body 2.
The electric fusion joint 1 may be buried facing the outer peripheral surface of the connector 1 and connected to the terminal 4 for energization via the conducting wire 43 to the connecting member 42. Further, as shown in the figure, the energizing terminal 4 does not need to be formed in an endless ring shape, but may be an end-shaped one in which a rod-shaped conductive member is formed in a ring shape.

Further, in the present embodiment, three energized locations are provided on the outer peripheral surface of the resin pipe main body 2, but the number is not particularly limited to three, and a plurality of energized locations are provided. If so, there may be two places, four places, or the like.

[0030]

As described above, according to the present invention, power can be supplied to the power supply terminal from any circumferential direction irrespective of the state of insertion of the electrofusion joint. Even in a poor place, it is possible to easily carry out the energizing work.

[Brief description of the drawings]

FIG. 1 is a partially broken side view schematically showing an overall configuration of an electrofusion joint.

FIG. 2 is a partial cross-sectional view showing various embodiments of an energizing terminal.

FIG. 3 is a partial sectional view showing still another embodiment of an energizing terminal.

FIG. 4 is a partially broken side view showing another embodiment of the electric fusion joint.

FIG. 5 is a perspective view schematically showing an overall configuration of the connector.

FIG. 6 is a partial sectional view showing various shapes of the connector.

FIG. 7 is a perspective view showing another embodiment of the connector.

FIG. 8 is a partially broken side view and a sectional view taken along line VIII-VIII, showing the electro-fusion joint according to Example 2.

FIG. 9 is a sectional view showing another example of the electrofusion joint according to the second embodiment.

FIG. 10 is a partially broken side view and a cross-sectional view taken along line XX showing another example of the electrofusion joint according to Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric fusion joint 2 Resin pipe main body 3 Coil 4 Terminal for energization

Claims (1)

(57) [Claims] 1. An electric fusion joint comprising a coil which generates heat by energization embedded in an inner peripheral surface of a resin pipe main body, and is electrically connected to an end of the coil along a circumferential direction of the resin pipe main body. An electric fusion joint, wherein a current-carrying terminal constructed as described above is provided, and the current-carrying terminal is exposed so as to be able to conduct over a plurality of locations or the whole of the outer peripheral surface of the resin pipe main body.