JPH11287381A - Induction coil for fusion attachment and method for fusion attachment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the fabrication costs by allowing one sort of induction coil to work well in fusion attachment operation for different size members and establish an effective joining in thermal fusion attachment and also a lightweight construction. SOLUTION: A plurality of spiral coils 31-36 are arranged in a single row in the longitudinal direction and buried in a flexible band 2 capable of being fixed to a plastic pipe along its periphery and being wound on a socket type fitting for fusion attachment of plastic pipe where a heater emitting heat by electromagnetic induction is embedded on the side with the inside surface, and are equipped with respective high-frequency current feeding terminals 31a and 31b through 36a and 36b capable of being connected in series or parallel and also switched between On and Off to the two terminals 4a and 4b of a high-frequency power supply 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the fusion welding of plastic pipes such as gas pipes using socket type joints,
More specifically, the present invention relates to an induction coil device for fusing a plastic tube and a method of fusing the same, which are used when a repair member for repairing a scratch generated on an existing plastic tube is bonded to the plastic tube. A plastic pipe and a fusion member such as a plastic plate-shaped repair member disposed on the outer peripheral surface of the plastic pipe and a plastic socket type joint of the same type as the plastic pipe made of a polyolefin resin and a damaged portion of the plastic pipe are covered. TECHNICAL FIELD The present invention relates to a fusion induction coil and a fusion method in which an eddy current is generated by electromagnetic induction in a magnetic alloy heater buried on an inner peripheral surface side of a fusion member to generate heat and heat fusion is performed. .

[0002]

2. Description of the Related Art In a fusion method using an induction coil device for fusing plastic pipes of this kind, the size of a fusion member to be used and the inner peripheral surface of the member are buried in accordance with the diameter of the plastic pipe. The size of the heater is determined. Therefore, in order to give an appropriate amount of heat to the heaters of the welding members having different sizes, conventionally, as an induction coil for supplying a high-frequency current to the heater by electromagnetic induction, the degree of curvature is different for each size of the plastic tube and the welding member. A method of preparing a plurality of types of induction coil devices in which induction coils are held by different half-cylindrical members, and selectively using the plurality of types of induction coil devices selectively according to the size of the fusing member. Was adopted.

[0003]

However, in the case of the above-described conventional induction welding coil device for plastic pipe and the above-mentioned welding method, there are many types of diameters of the plastic pipe and sizes of the welding members. A large number of induction coil devices to be provided (necessary) is required, and the production cost of each induction coil device is high, which causes a problem that the fusion work cost is increased. Therefore, when a fusion bonding member having a small size is fusion-bonded, by selecting and using an induction coil device larger than the size, it is possible to reduce the number of prepared (conventional) induction coil devices accordingly. However, this causes a power loss due to the current being supplied to the induction coil portion that does not need to be energized, which reduces the efficiency of the predetermined fusion bonding and increases the weight of the coil portion that does not need to be energized. However, there is also a problem that handling of the induction coil device is disadvantageous.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to reduce the manufacturing cost by using one type for fusion bonding of fusion members of any size, and to reduce the manufacturing cost. An object of the present invention is to provide an induction coil device for fusing a plastic tube and a method for fusing the same, which can realize weight reduction that is advantageous in terms of fusion bonding and handling.

[0005]

According to a first aspect of the present invention, there is provided an induction coil device for fusing plastic pipes, wherein a heater is embedded on an inner peripheral surface side. A fusion induction coil for causing the heater of the member to generate heat by electromagnetic induction and fusing the fusion member to another plastic member, wherein a plurality of spiral coils are arranged in a flexible band in the longitudinal direction. Are arranged and buried in a line, and a plurality of spiral coils can be connected in series or in parallel, and a terminal for supplying a high-frequency current is provided for each spiral coil. is there.

According to a second aspect of the present invention, there is provided a plastic pipe fusing member in which a heater for generating heat by electromagnetic induction is buried on an inner peripheral surface of the plastic pipe fusing member along an outer peripheral surface of the plastic pipe. After fixedly installed on the outer periphery of the welding member, a plurality of spiral coils are arranged in a line in the longitudinal direction, and a flexible strip formed and embedded therein is wound thereon. By supplying high-frequency power from a high-frequency power source to a spiral coil located in a length range corresponding to the heater among the coils, the heater is heated by electromagnetic induction, and the fusion member and the plastic tube are fusion-bonded. It is characterized by doing.

According to the present invention having the above-described structure, the welding member is fixedly installed in a position along the outer peripheral portion of the plastic pipe, and the flexible belt is wound around the outer periphery of the welding member. Out of a plurality of spiral coils arranged and embedded in a line in the flexible strip in a length range corresponding to the size of the magnetic alloy heater in the fusing member. One or more spiral coils will face the magnetic alloy heater. In this state, by supplying high-frequency power from the high-frequency power supply only to the spiral coil facing the magnetic alloy heater, an eddy current is generated by electromagnetic induction in the magnetic alloy heater to generate heat, thereby causing the outer peripheral surface of the plastic pipe and the melting point to melt. The inner peripheral surfaces of the wearing members can be fusion-bonded to each other in an area range corresponding to the size of the magnetic alloy heater. As a result, only one kind of fusion induction coil device is prepared, and this one kind of fusion induction coil device can be used for fusion members of any size selected according to the diameter of the plastic pipe. It is also possible to use the same for the joining.

[0008] Further, instead of using a single induction coil device that is simply large in size to accommodate fusion members of all sizes, the number of currents to be supplied to a plurality of spiral coils in accordance with the size of the fusion member is increased. In particular, when a small-sized fusion-bonding member is fusion-bonded, there is no power loss such as energizing all spiral coils, and a predetermined fusion-bonding can be performed efficiently. In addition, it is easier to reduce the weight of the entire apparatus as compared with a conventional coil apparatus in which an induction coil is held by a half-tubular member.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an induction coil device for fusing a plastic tube according to the present invention. The induction coil device for fusing plastic tube 1 is a flexible band 2 that can be wound around the outer periphery of a plastic tube fusing member described later.
In the longitudinal direction, a plurality of spiral coils 31 (shown as six in the drawing, but may be three or more) are provided.
32, 33, 34, 35, and 36 are arranged in a line and buried, and these spiral coils 31 to 36 are connected to a switch S.
It can be connected in series via W1 to SW5,
For each of the spiral coils 31 to 36, energizing terminals 31 a and 31 b to switch connection / disconnection between both terminals 4 a and 4 b of the high-frequency power supply 4 in parallel via switches SW 6 to SW 15.
36a and 36b are provided.

In the induction coil device 1 for fusing plastic pipes having the above-described configuration, the terminals 4a and 4b of the high-frequency power source 4 and the arbitrary number of the spiral coils 31 to 36 among the six are connected via the switches SW6 to SW15. Energizing terminal 31
a, 31b to 36a, 36b, and the spiral coils connected to the high-frequency power supply 4 are connected in series via the switches SW1 to SW5, so that SW1 to SW5 are cut off. SW6 ~ SW
15 is selectively switched and connected in parallel to the high frequency power supply, so that high frequency power is supplied from the high frequency power supply 4 to only an arbitrary number of the spiral coils.

Next, an operation procedure for fusing and joining plastic pipes to each other with a socket-type joint as an example of a fusing member using the plastic tube fusing induction coil device 1 having the above-described configuration will be described with reference to FIGS. This will be described with reference to FIG.

As shown in FIG. 2, two joined plastic pipes 10A, 1 made of a polyolefin resin such as polyethylene or polypropylene and arranged concentrically.
0B, these plastic tubes 10A, 10B
A plastic socket type joint 11 of the same type as above is fitted and fixedly installed so as to straddle between both plastic pipes 10A and 10B. A magnetic alloy heater 12, which is formed by braiding a magnetic alloy wire having a predetermined Curie temperature into a net shape, is embedded in an annular shape on the inner peripheral surface side of the socket type joint 11.

Thereafter, a flexible band 2 constituting the plastic tube fusion induction coil device 1 is wound around the outer periphery of the socket type joint 11. At this time, if the diameters of the plastic pipes 10A and 10B to be joined and the diameter of the corresponding socket-type joint 11 are large, for example, as shown in FIG. All of the coils 31 to 36 face the magnetic alloy heater 12 of the socket-type joint 11, and the above-mentioned plastic pipes 10A, 10A to be joined.
When the diameter of B and the diameter of the corresponding socket-type joint 11 are small, for example, as shown in FIG. 4, four of the six spiral coils 31 to 36 in the induction coil device 1 for fusing plastic pipes have four spirals. The coils 31 to 34 face the magnetic alloy heater 12 of the socket joint 11.

Therefore, all six spiral coils 31 facing the magnetic alloy heater 12 of the socket type joint 11 are provided.
To 36 energizing terminals 31a, 31b to 36a, 36b or four energizing terminals 31 of spiral coils 31 to 34
a, 31b to 34a, 34b are connected to the switches SW6 to S
While being connected to both terminals 4a and 4b of the high-frequency power supply 4 via W15, the spiral coils connected to the high-frequency power supply 4 are connected in series via the switches SW1 to SW5.

In this connection state, high frequency power is supplied from the high frequency power supply 4 to the six or four spiral coils facing the magnetic alloy heater 12 so that electromagnetic induction is applied to the entire surface of the magnetic alloy heater 12. As a result, an eddy current is generated and the heater 12 generates heat, and both plastic tubes 10
The outer peripheral surfaces of A and 10B and the inner peripheral surface of the socket-type joint 11 are fusion-bonded to each other in an area range corresponding to the size of the magnetic alloy heater 12.

FIGS. 5 to 7 are explanatory views of another example of use of the induction coil device 1 for fusing plastic pipes having the above-described configuration for repairing a damaged portion generated on the outer peripheral surface of an existing plastic pipe 10. FIG. Yes, work procedures for repairing plastic pipes will be described below.

In FIG. 5, reference numeral 15 denotes an example of a plastic tube fusion member, which is a curved plate-like repair member made of the same polyolefin resin as the plastic tube 10 to be repaired. The magnetic alloy heater 12 'is embedded in an annular shape on the inner peripheral surface side of the plastic tube 10 whose surface 15a is to be repaired and on the inner peripheral surface side.

The curved plate-shaped repairing member 15 is arranged such that the magnetic alloy heater 12 ′ on the inner peripheral surface surrounds the damaged portion 16 of the plastic tube 10. As shown in FIG. 6, a plastic tube 1 is fixed using a fixing jig 17 such as a plastic band.
Fix to 0.

Subsequently, as shown in FIG. 7, the flexible band 2 constituting the induction coil device 1 for fusing the plastic pipe is wound around the outer periphery of the curved plate-shaped repair member 15. At this time, too, according to the diameter of the plastic tube 10 and the diameter of the curved plate-shaped repair member 15 corresponding thereto, the six spiral coils 31 to 31 in the induction coil device 1 for fusing the plastic tube.
An arbitrary number of the 36 faces the magnetic alloy heater 12 ′ of the curved plate-shaped repair member 15.

Thereafter, as in the above embodiment, only the energizing terminals of the spiral heater facing the magnetic alloy heater 12 'are connected to both terminals 4a and 4b of the high frequency power supply 4, and the high frequency power supply 4 By connecting the spiral coils connected to each other in series via the switches SW1 to SW5 and supplying high frequency power from the high frequency power supply 4 to the number of spiral coils facing the magnetic alloy heater 12, An eddy current is generated by electromagnetic induction on the entire surface of the magnetic alloy heater 12 ′, and the heater 12 ′ generates heat, so that the outer peripheral surface of the plastic tube 10 and the inner peripheral surface of the curved plate-shaped repair member 15 become the magnetic alloy heater 12 ′. Are welded to each other in the area range corresponding to the size of the plastic pipe 10, and the damaged portion 16 of the plastic pipe 10 is repaired by the repairing member 15.

The plastic tube 10 to be joined in this way is
6 spiral shapes corresponding to the size of the repairing member 15 selected and used in accordance with the diameters of A and 10B and the size of the socket type joint 11 or the size of the damaged portion 16 occurring in the plastic tube 10. By supplying a high-frequency current to only a required number of spiral coils among the coils 31 to 36, an appropriate eddy current is always generated by magnetic induction in the magnetic alloy heater 12 or 12 ′ of each size, so Fusion bonding between the socket type joint 11 or the curved plate-shaped repair member 15 and the plastic pipes 10A, 10B, 10 can be performed in an area range corresponding to the size of the alloy heater 12 or 12 '. Thus, by preparing only one kind of induction coil device 1 for fusing plastic pipes, it is possible to use the same for fusion bonding of the socket-type joint 11 and the curved plate-shaped repair member 15 of any size. .

Also, instead of using a single induction coil device 1 that is merely large to accommodate welding members of all sizes, energizing a plurality of spiral coils according to the size of the welding members is not necessary. Since the number and the range are changed, particularly in the case of fusion-bonding a small-sized fusion-bonding member, there is no power loss such as energizing all of the plurality of spiral coils, and a predetermined fusion-bonding can be performed efficiently. .

[0023]

As described above, according to the present invention, only one kind of fusion induction coil device is prepared, and this one kind of fusion induction coil device can be adapted to the diameter of the plastic pipe. Since it can also be used for fusion bonding of any size fusion-bonding member selected for use, it is possible to reduce manufacturing costs and management costs. Also, rather than using a single induction coil device that is simply large to accommodate fusion members of all sizes, the number and range of currents to a plurality of spiral coils are adjusted according to the size of the fusion members. In particular, when a small-sized fusion-bonding member is fusion-bonded, there is no power loss such as energizing all of the plurality of spiral coils. This has the effect of making it easier to reduce the weight of the entire device as compared to a conventional coil device in which an induction coil is held by a cylindrical member.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an induction coil device for fusing a plastic tube according to the present invention.

FIG. 2 is a longitudinal sectional side view showing a state in which the plastic tubes are fusion-bonded to each other by a socket-type joint using the plastic tube fusion induction coil device.

FIG. 3 is a longitudinal sectional front view showing a state in which a large-sized plastic pipe and a socket-type joint are fusion-bonded.

FIG. 4 is a longitudinal sectional front view showing a state where a small-sized plastic pipe and a socket-type joint are fusion-bonded.

FIG. 5 is a perspective view showing a repair member that is fusion-bonded to a plastic pipe using the induction coil device for plastic pipe fusion according to the present invention.

FIG. 6 is a perspective view showing a state in which the repair member is fixed to an outer periphery of a plastic pipe.

FIG. 7 is a longitudinal sectional side view showing a state in which the repair member is fusion-bonded to a plastic pipe using an induction coil device for fusing the plastic pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Induction coil device for fusion of plastic pipes 2 Flexible band 4 High frequency power supply 12, 12 'Magnetic alloy heater 31-36 Spiral coil 31a, 31b-36a, 36b Terminal for conducting electricity 10, 10A, 10B Plastic pipe 11 Socket type Joint (an example of the welding member) 15 Curved plate-shaped repair member (another example of the welding member)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidekazu Enomoto 64 Ishizu-Kitacho, Sakai City, Osaka Inside Kubota Vinyl Pipe Factory

Claims (2)

[Claims] 1. A fusing guide for fusing the fusing member to another plastic member by causing the heater of the fusing member made of plastic having a heater embedded on the inner peripheral surface side to generate heat by electromagnetic induction. A plurality of spiral coils are arranged in a line in the longitudinal direction in a flexible band, and embedded in the flexible belt, so that the plurality of spiral coils can be connected in series or in parallel. A fusion induction coil, characterized in that a terminal for supplying a high-frequency current is provided for each coil. 2. A plastic pipe fusing member having a heater buried on the inner peripheral surface side by electromagnetic induction embedded therein is fixedly installed in a position along the outer peripheral surface of the plastic pipe, and is then longitudinally disposed on the outer periphery of the fusing member. A plurality of spiral coils are arranged in a line in a row, and a flexible band formed by being buried is wound, and a spiral located in a length range corresponding to the heater among the plurality of spiral coils. A fusion method, comprising: supplying high-frequency power from a high-frequency power supply to the coil, causing the heater to generate heat by electromagnetic induction, and fusion-bonding the fusion-bonding member to the plastic tube.