JP2006045627A - Induction-heating coil for ring member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction-heating coil for ring member with which the conventional heating method is improved so as to fit to not only heating for hardening but also, particularly, an annealing and a tempering to the ring member hardened with a cold-working. <P>SOLUTION: On the outer surface of the ring member W to be heated, an outer surface induction body 10 composed of an almost whole circular annular electric conductive body 11 and an inner surface induction body 20 composed of two semi-circular arc electric conductive bodies 21, 22 in the inner surface, are concentrically arranged, and the one end part 21a of one side of the semi-circular arc electric conductive body 21 in the inner surface induction body 20, is connected with a terminal part 2, and the other end part 21b is connected with the one end part 11a of an outer surface induction body 10, and the other end part 11b of this outer surface induction body 10 is connected with the one end part 22a of the other semi-circular arc electric conductive body 22, and the other end part 22b is connected with a terminal part 5, and then, the inner surface induction body 20 and the outer surface induction body 10 are connected in series so that the current is caused to flow in the circular reverse direction. The positions of the connecting parts 11a, 11b in the outer surface induction body 10 and the positions of the connecting parts 21a, 21b, 22a, 22b of the semi-circular arc electric conductive bodies 21, 22, are arranged so as to be shifted to ≥25° at the circular angle of the inner surface induction body 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an induction heating coil in a heat treatment such as annealing a ring member cured by cold working or the like by induction heating.

Conventionally, when a ring member after cold working is annealed, a heating furnace using a fuel such as electricity, gas, or oil has been used. However, these heating furnaces are large and require a large installation area in the factory. In addition, such a heating furnace has a problem that it is difficult to line it with other processing machines.
Therefore, heating by induction heating has been requested, but conventionally, a method of arranging an annular conductor coil on the outer periphery of the ring member and heating only from the outer periphery has been performed, but in order to heat the whole uniformly Required a long heating time.
Therefore, the present inventors previously presented an induction heating device for a cylindrical object that simultaneously heats from the inner and outer surfaces of the ring member (Patent Document 1).
Japanese Patent Application No. 2002-372304

  The induction heating device of Patent Document 1 is particularly suitable for heating a ring member having a recess on the inner periphery, but the present invention improves this, and the ring is hardened not only by quenching heating but also by annealing or cold working. It is an object of the present invention to provide an induction heating coil for a ring member, which is an improved conventional heating method so as to be suitable for normalizing a member.

  In order to achieve the above object, an induction heating coil of a ring member according to the present invention has a concentric circular inner surface derivative and an outer surface derivative for heating the inner and outer surfaces, respectively, on the inner and outer surfaces of the ring member to be heated. It is characterized in that the current of the derivative and the outer surface derivative is connected in series so as to flow in the opposite direction of the circumference.

  By simultaneously heating from the inner and outer surfaces of the ring member in this way, it is possible to rapidly and uniformly heat the conventional method of heating only from the outer periphery. Further, since the current of the inner and outer derivatives flows in the opposite direction of the circumference, the heating from the inside and outside is performed evenly without interference.

  In the induction heating coil of the ring member of the present invention, the outer surface derivative is formed of an annular conductor that forms substantially the entire circumference, the inner surface derivative is formed of two semicircular conductors, and the currents of the inner surface derivative and the outer surface derivative are It is desirable to connect in series so that can flow in the opposite circumferential direction.

  In this way, by using two semicircular conductors obtained by dividing the inner derivative instead of one annular conductor, it is possible to obtain an advantage that it is easy to manufacture a coil in which the connection position of the inner derivative and the outer derivative is changed.

  Furthermore, in the induction heating coil of the ring member of the present invention, one end of one semicircular conductor of the inner surface derivative is connected to the terminal portion, the other end of the one semicircular conductor is connected to one end of the outer surface derivative, The other end of the outer surface derivative is connected to one end of the other semicircular conductor, the other end of the other semicircular conductor is connected to the terminal portion, and the current of the inner surface derivative and the outer surface derivative flows in the opposite direction of the circumference. The connection position of the outer surface derivative and the connection position of the semicircular conductor of the inner surface derivative are arranged so as to be shifted by 25 degrees or more in circumferential angle when the ring member is heated. Desirable for uniform heating in a short time with or without rotation.

  Conventionally, when two coils are connected in series, they are usually connected at a portion corresponding to the same position mainly in order to simplify the connecting portion. As a result of the experiment, the inventors have found that when the ring member is heated with a heating coil in which the angle α = 0 of the connection position shown in FIG. 1, that is, the connection position of the outer surface derivative is on the same center line as the connection position of the inner surface derivative, It has been found that the occurrence of a temperature difference of 80 ° C. or more is unavoidable depending on the position. On the other hand, it has been found that when the connection position is heated by a coil arranged so as to be shifted by α ≧ 25 degrees in the figure, it is heated to a substantially uniform temperature. In the case of actual ring member heating, since the ring member is heated while rotating, such a temperature difference does not occur. However, even in the case of rotation, the connection position is shifted in this way for rapid uniform heating. We found it desirable to place. This shift angle is less than 25 degrees, and the effect is small. If the angle is too large, the structure of the connecting portion becomes complicated and difficult to manufacture, so 40 ± 15 degrees is desirable.

  According to the induction heating coil of the ring member of the present invention, since it can be heated to a uniform temperature more rapidly than the conventional induction heating coil, the working time can be shortened, the energy consumption can be reduced, and the cost can be reduced.

  Hereinafter, the induction heating coil of the ring member of the present invention will be specifically described based on the illustrated embodiment. FIG. 1 is a diagram illustrating a connection circuit of an induction heating coil of a ring member of the present invention, and FIG. 2 is a perspective view of the induction heating coil of the ring member of the present invention.

  1 and 2, an induction heating coil 1 of a ring member according to the present invention includes an outer outer surface derivative 10 disposed concentrically with a predetermined gap on the inner and outer circumferences of a ring member to be heated (hereinafter referred to as a workpiece) W. And an inner inner surface derivative 20.

  The outer surface derivative 10 is composed of a substantially circular conductor 11 around the circumference, and the inner surface derivative 20 is composed of two semicircular semicircular conductors 21 and 22. The terminal portion 2 is connected to one end 21 a of one semicircular conductor 21, and the other end 21 b is connected to one end 11 a of the outer annular conductor 11 via the first lead portion 3. The other end 11b of the outer annular conductor 11 is connected to one end 22a of the other semicircular arc conductor 21 via the second lead portion 4, and the terminal portion 5 is connected to the other end 22b. As a result, a coil through which current flows in the opposite direction is formed on the annular conductor 11 of the outer surface derivative 10 and the two semicircular conductors 21 and 22 of the inner surface derivative 20.

  As shown in FIG. 1, the connecting portions 21a, 22b, 21b, and 22a of the semicircular conductors 21 and 22 are placed at positions almost opposite to the circle by 180 degrees, but the connecting portions 11a and 11b of the annular conductor 11 on the outer surface are It is arranged to be shifted by 30 degrees from the connecting portion of the semicircular conductors 21 and 22 at a circumferential angle (α in the figure). As a result, even if the workpiece is heated without rotating, the temperature drop corresponding to the connecting portion is reduced, and rapid soaking is possible even when rotating and heating. The shifting angle α is preferably 40 ± 15 degrees.

  The workpiece W is inserted between the outer surface derivative 10 and the inner surface derivative 20 of the heating coil having the above configuration, and the workpiece W is heated while rotating.

A heating experiment was performed under the following conditions using the heating coil having the above-described configuration.
Work specification: Work size: 125mmφ × 106mmφ × 20mm
Work material: S45C
Heating coil specifications: Inner surface derivative: Coil outer diameter x width: 90 mmφ x 35 mm
Outer surface derivative: Coil inner diameter x width: 155 mmφ x 35 mm
Heating conditions: frequency x power 3 kHz x 132 kW
Heating time: 11s
Heating temperature: 950-1000 ° C

  As a result of heating the workpiece having a hardness of Hv 240 to 260 by cold working under the above conditions, the hardness after heating was normalized to Hv 180 to 190. This heating time was reduced by about half compared with the conventional method.

  As described above, according to the induction heating coil of the ring member of the present invention, the heating time can be greatly shortened compared with the conventional method, and uniform heating can be performed.

  As described above, according to the induction heating coil of the ring member of the present invention, the work efficiency is greatly improved, so that the cost of heat treatment can be reduced, contributing to industrial development.

It is a figure which shows the connection of the induction heating coil of the ring member of embodiment of this invention. It is a perspective view of the induction heating coil of the ring member of the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction heating coil, 2 Terminal part, 3 1st lead part, 4 2nd lead part, 5 Terminal part, 10 Outer surface derivative, 11 Annular conductor, 20 Inner surface derivative, 21, 22 Semicircular conductor, W Workpiece (ring member)

Claims (3)

In the induction heating coil of the ring member, annular inner surface derivatives and outer surface derivatives for heating the inner and outer surfaces are arranged concentrically on the inner and outer surfaces of the ring member to be heated, and the currents of the inner surface derivative and the outer surface derivative are opposite in the circumferential direction. An induction heating coil of a ring member, which is connected in series so as to flow through the ring. The outer surface derivative is composed of an annular conductor that forms almost the entire circumference, the inner surface derivative is composed of two semicircular arc conductors, and is connected in series so that the current of the inner surface derivative and the outer surface derivative flows in opposite directions of the circumference. The induction heating coil for a ring member according to claim 1, wherein the coil is an induction heating coil. One end of one semicircular conductor of the inner surface derivative is connected to the terminal portion, the other end of the one semicircular conductor is connected to one end of the outer surface derivative, and the other end of the outer surface derivative is connected to the other semicircular conductor. Connected to one end, the other end of the other semicircular conductor is connected to the terminal portion, and connected in series so that the current of the inner surface derivative and the outer surface derivative flows in the opposite direction of the circumference, the connection portion of the outer surface derivative The induction heating coil of a ring member according to claim 2, wherein the position and the position of the connecting portion of the semicircular conductor of the inner surface derivative are arranged with a circumferential angle shifted by 25 degrees or more.

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