JP2513250Y2 - High frequency heating torch for heating bolts - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating torch for heating bolts.

[0002]

2. Description of the Related Art Heating of bolts for tightening or loosening large structure tightening bolts has conventionally been done by heating with flammable gas or heating with electric resistance. 4 As shown in the longitudinal sectional view, the metal outer cylinder 21 is inserted into the hole opened in the axial center of the bolt.
There is one in which a resistance wire 22 covered with a heat resistant insulator is housed.

However, the conventional gas heating is difficult to control the temperature and often overheats to damage the bolt. In addition, in the heating torch using the resistance wire shown in FIG. 4, the metal outer cylinder 21 is heated by the resistance wire 22, and the bolt is heated by the radiation and convection of the heat, so that the efficiency is low and a large power is supplied to the thin metal outer cylinder 21. Since it cannot be passed through, it requires a long heating time.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and it is possible to supply a large amount of electric power to the shaft center hole of the bolt, and to use the high frequency induction heating to efficiently and shortly drive the bolt. An object of the present invention is to provide a high-frequency heating torch for heating a bolt, which can be heated by.

[0005]

To this end, the present invention is a heating torch for high-frequency heating inserted in a shaft hole of a bolt, the tubular conductor having an outer diameter inserted in the shaft hole of the bolt, and An inner conductor coaxially inserted into the inside of the tubular conductor, the tip of which is connected to the ends of the tubular conductor, a power supply terminal attached to the base ends of both conductors, and a high-permeability member fitted around the inner conductor. It is characterized by having a magnetic susceptibility core.

[0006]

In the high frequency heating torch for heating bolts of the present invention, high-frequency induction heating is performed by the tubular conductor from the inner surface of the axial hole of the bolt, so that the bolt itself directly generates heat, so that efficient heating is performed. At this time, the magnetic flux from the inner conductor is absorbed by the high transmittance core so that the magnetic flux outside the tubular conductor is not canceled by the current flowing through the inner conductor.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of a high frequency heating torch for heating bolts according to the present invention will be described. FIG.
Is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is an explanatory view of a use state.

In FIGS. 1 and 2, a tubular conductor 1 having an outer diameter to be inserted into a shaft center hole of a bolt and having a closed tip made of a good conductor metal such as copper has a tubular shape for water cooling. An inner conductor 2 made of a good conductor metal such as copper is inserted, and its tip is connected to the tip of the tubular conductor 1. A ceramic heat-resistant insulating support plug 3 that coaxially holds and seals the inner conductor 2 is fitted at the proximal end of the tubular conductor 1, and the outer surface of the tubular conductor 1 contacts the inner surface of the axial center hole of the bolt. The heat resistant insulating coating film 4 is coated so as not to be grounded.

A power source terminal 5 and a power source terminal 6 are attached to the base ends of the tubular conductor 1 and the inner conductor 2, respectively, and are connected to a high-frequency power source 7. The former power source terminals 5 and 6 are cooling water outlets. The latter also serves as cooling water inlets, and a water guiding port 8 is formed at the tip of the inner conductor 2. Furthermore, around the inner conductor 2, several high magnetic permeability cores 9 that absorb the magnetic flux generated by the inner conductor 2 are externally fitted.

The procedure for heating the bolt with such a heating torch will be described with reference to FIG. 3. The stud bolt 10 for fastening the flanges 13 and 14 of the structure is screwed into the flange 14. The flanges 13 and 14 are tightened by the nut 12 fitted in the. At this time, in order to further increase the tightening force, the tubular conductor 1 of the heating torch is inserted into the shaft center hole 11 of the stud bolt 10.
When high frequency power of, for example, 10 to 20 kW is supplied from the power supply terminals 5 and 6 by inserting, the stud bolt 10 is heated and expanded in a short time by the induction heating by the magnetic flux generated in the tubular conductor 1 and expanded by a predetermined amount. By tightening and cooling the nut 12, the tightening force of the stud bolt 10 is increased.

[0011]

In summary, according to the present invention, there is provided a heating torch for high-frequency heating which is inserted into the axial hole of a bolt, the tubular conductor having an outer diameter inserted into the axial hole of the bolt, and the tubular conductor. An inner conductor coaxially inserted into the inside and having a tip connected to the tip of the tubular conductor, a power supply terminal attached to the base ends of the both conductors, and a high-permeability core fitted around the inner conductor. Since it is possible to supply a large amount of electric power to the shaft center hole of the bolt and to efficiently heat the bolt by high frequency induction heating in a short time, a high frequency heating torch for heating the bolt is provided. Above all, it is extremely useful.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a high frequency heating torch for heating bolts according to the present invention.

2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is an explanatory view of a usage state of the heating torch of FIG. 1.

FIG. 4 is a vertical sectional view of a conventional heating torch.

[Explanation of symbols]

 1 Tubular conductor 2 Inner conductor 3 Heat-resistant insulating support plug 4 Heat-resistant insulating coating film 5 Power supply terminal 6 Power supply terminal 7 High frequency power supply 8 Water inlet 9 High permeability core

Claims (1)

(57) [Scope of utility model registration request] 1. A heating torch for high-frequency heating inserted in a shaft hole of a bolt, the tubular conductor having an outer diameter inserted in the shaft hole of the bolt, and coaxially inserted inside the tubular conductor. The inner conductor having a tip connected to the tip of the tubular conductor, a power supply terminal attached to the base ends of the both conductors, and a high-permeability core fitted around the inner conductor. High frequency heating torch for heating bolts.