JPS63284789A - Induction heating method - Google Patents

Abstract

PURPOSE:To aim at the uniformization of temperature distribution in a plate cross direction by covering a U-shaped core on a conductor of an inductor, installing it in opposition to the surface of a heated plate, and installing a magnetic induction core in a position being opposed to the inductor at the backside of an edge part of the plate. CONSTITUTION:The inductor 1 that covered a U-shaped core 3 on a conductor extending in a plate cross direction of a plate is installed as being opposed to a plate surface, and at the backside of an edge part of the plate 10, there is provided with a magnetic induction core 2 in a position being opposed to the inductor 1. And, frequency f(Hz) of a power source to be fed to the inductor 1 is set down to f<(50.3/t)<2>.rho at a time when thickness of the plate as a heated material is set t(m/m) and specific resistance of the said plate rho(muOMEGA.cm). With this constitution, the alternating magnetic flux produced by the inductor 1 pierces through the plate 10 consisting of a magnetic material in a nonmagnetic state withing the range of temperature of more than a nonmagnetic material or a Curie point, forming a closed magnetic circuit making the magnetic induction core 2 set up as opposed to the plate edge backside a magnetic path, and magnetic flux density at the edge part is raised and a temperature up in the edge part is performed, thus the promotion of soaking with the central part in the plate cross direction is accelerated in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to an induction heating method for heating a plate material to be heated in a striped manner, and particularly relates to an induction heating method where the plate material is a non-magnetic material or a plate material made non-magnetic at high temperature. The present invention relates to an induction heating method that aims to equalize the temperature in the width direction.

B0 Summary of the Invention In an induction heating method for heating a non-magnetic plate or a plate in a non-magnetic state in the width direction of the plate, a conductor extending linearly in the width direction 1Cf3 of the plate is provided with a U-shaped core'. An inductor stacked on the plate is provided facing the surface of the plate, and a magnetic fermentation core is disposed on the surface of the edge of the plate at a position facing the inductor to supply power to the curved rib inductor. The frequency f of (50,
, 3/l)" x ρ (where t is the thickness of the plate material, and ρ is the specific resistance of the plate material), thereby making the heating temperature distribution uniform in the width direction of the plate at the edge and center. be.

C0 Conventional technology induction heating equipment rl! ? When heat treatment is performed in the width direction of a thin steel plate using a transverse magnetic flux heating method, the transverse magnetic flux heating (TRO) method as shown in Figure 4 (a) and lbl has come to be used. That is, in FIG. 4(a), an inductor 1O1 having a conductor formed in a rectangular shape is arranged so as to extend in the width direction of the surface of a plate material 110, which is a heated material, so that the rectangular surface is parallel to the plate material 110. FIG. 3 is a diagram showing induction heating applied in the width direction of the plate material 110. This inductor 101 has a medium frequency or high frequency alternating current.
When power is supplied from a source E, an induced current 1 flows through the plate 110 as shown in FIG. 1al, and this current 1 heats the plate 110.

FIG. 5 shows the flow of the induced current 1 generated in this plate material 110. As shown in the above, the current 1 induced in the I/C plate material 110 flows through the circulation flow path A facing the conductor of the inductor 101.
stomach? Form and flow. In the edge parts A at both ends, the induced current 1 flows concentrated at the tip of the edge, so the current becomes high in this part, as shown in Figure 4 ra).
The L joint portions 110 to tiob of the plate material 110 were particularly heated, causing overheating.

In addition, Fig. 4 1bl shows the structure ke, the inductor t formed in a rectangular shape.
ot This inductor 101 is arranged so that the rectangular surface is ineffective against the plate material 110 and is heated.
The 11L flow 1 induced by heating using 11L flows as shown in FIG. 5(b). As shown in the figure, this electromotive force fL1 flows in a concentrated manner in the part facing the conductor of the inductor 101 and heats the central part of the plate 110 (1-/JO), but it is dispersed and low on both sides of the conductor. +lle flows in a tight manner to generate circulation channels A, A, and B. If the plate 110 is a magnetic material, the paths of magnetic flux passing through the plate 110 are aligned at the edges, so that The dispersion of the induced current becomes smaller, and the edge portions 110a and 1l as well as the center portion
Qb is also heated to a higher temperature. However, if the plate material 110 is a non-magnetic material, or if a magnetic material reaches a temperature above the Curie point and becomes a non-magnetic material, the temperature will rise in the central part of A where the temperature is high, but the temperature will rise at the edge part. In the part A, the current v due to current division
I! Because of the lower temperature, the temperature rise at the edge portions ttoa and ttob was slightly lower than that at the center portion, resulting in underheating. At 8 minutes, aLtlL flows in a dispersed manner, so the temperature rise is extremely low.

D8 Problems to be Solved by the Invention Even if it is attempted to perform heating by induction heating in a narrow range in the width direction of a plate material, it is difficult to carry out soaking heating in the width direction of the plate material, especially when When the heating material is a non-magnetic material, or when a magnetic material such as steel is transformed,
When the temperature is increased to a non-magnetic region by exceeding a certain temperature, the difference in temperature between the edge portion and the center of the plate material is large, making it difficult to equalize the temperature and causing ILI.

The present invention has been created in view of the above-mentioned problems, and when a magnetic conductive core metal is disposed at the edge portion on the opposite side of the plate material facing the inductor provided by abrasive material in the width direction of the plate material, the rc @Supplied to the conductor [The frequency of the source is determined by the thickness of the plate material and the specific resistance of the plate material, and the temperature is equalized in the width direction between the edge part and the center part of the plate material.

Means for Solving Problem E1 The specific means used by the present invention for this purpose is to provide an inductor having a U-shaped core on a conductor extending in the width direction of the plate facing the surface of the plate, A magnetic induction core is disposed on the back surface of the edge portion of the plate at a position facing the inductor, and the frequency of the power supply to the inductor is 'Iif(Ifz)ThfA(5α3/
l(m)'x/, (aΩ, cs) to equalize the heat in the width direction of the plate between the edge portion and the center portion of the plate.

20 Effect By using the above-mentioned unitary means 7m, the alternating magnetic flux generated by the inductor passes through a plate made of a non-magnetic material or a calm material in a non-magnetic state with a temperature of 17 points or more. Throughout the page, a magnetic g conductor 7 is arranged facing the edge portion and surface of the plate material.
a? A closed magnetic path is formed as path lIa, and the flux density at the edge is 1f'? By raising the temperature tAk of the edge portion, it is possible to equalize the temperature in the width direction of the plate with respect to the center portion.

G. EXAMPLES Below, practical examples of the present invention will be explained in detail with reference to all the drawings.

The first figure is a diagram showing the main parts of the induction heating device according to the practical example of the present invention, 1a) 4 is a partially cutaway plan view, and (b1)
The figure is a view taken along the line X-X of figure la), and figure lc) is a view taken along line Y-Y of figure +b).

First, the configuration of an actual example will be explained. As shown in FIG. 1, an inductor 1 for performing spinning heating is formed into a rectangular shape as shown in FIG. 11143 (tb), and is connected to an induction heating device 5. A plate material 1θ in a stationary state, which is a heated material, is disposed close to the inductor 1, and the IEI inductor l is disposed in the width direction of the plate so that the rectangular direction is perpendicular to the surface of the plate material LO. It will be done. A beam-shaped core 3 is installed in a conductor portion of the inductor l facing the plate material 10.

The {circle around (2)}-shaped core 3 is placed over the inductor conductor from above with its opening facing down, and its length is slightly longer than the width of the plate 10. A magnetic induction core 2.2 is disposed at a position facing the inductor 1 across the plate material 10f. The magnetic induction cores 2, 2 are disposed close to the back surface of the plate 10 and at the edge of the plate 10, and are formed into a U-shape with the opening facing upward toward the plate 10. And - Naruko 1
The lead portion is insulated by an insulating plate 4.

The operation of the present textile example configured as described above will be explained. When the plate material 0 is in a non-ma state, the thickness of the plate material IO is t mum, and the characteristic resistance is ρμΩ・island, the power supplied to the inductor 1 by the heating induction source 5 is Frequency f (Ilz) k f< (50,3/l
)"By setting the size of ρ, the plate material to?y
- It has been demonstrated and widely stated that it produces a page-through magnetic flux, i.e., a transverse magnetic flux φ. By applying the electric power of the frequency f2 to the inductor l, a police box Nitto φ that passes through the non-magnetic plate 10 is generated by the inductor lK.

This inductor 1 has a U-shaped core covered with a conductor for a length longer than the width of the plate material LOO, and a magnetic induction core 2 is placed on the edge portion of the back surface of the 10,000 plate material IO, facing the inductor 1. As a result, the magnetic flux φ near the edge gIS concentrates on the magnetic induction core 2 with a large throughput fa'4, forming a path la as shown in FIG. 2 1a). Therefore, even if the material to be heated is a non-magnetic material, the magnetic flux at the edge of the plate 10 decreases, causing underheating at the edge as in the conventional case shown in M3 Figure 1bJ. No, Figure 2 1b
), the magnetic flux density is maintained at the same level as near the center, and the error lfl! The heating temperature of the central part is raised to approximately the same temperature as that of the central part. At the same time, the range of temperature increase in the central part of the violet is expanded toward the edge part to solve the problem of insufficient temperature rise caused by growth inside the edge part.

In addition, when heating a magnetic material such as an octopus plate over the non-magnetic region at 2 beyond the Curie point, the temperature in the magnetic region is as shown in Fig. 3(b).
As explained in the conventional example shown in 2, the central part and the edge part of the plate material are uniformly heated, and even in the non-magnetic area, underheating of the edge part is avoided by the action of the magnetic induction core 2, and the central part and the edge part are uniformly heated. is heated uniformly. As mentioned above, the action of the magnetic interrogation core occurs when the frequency of the n force supplied to the inductor l is f < (50,3/l)Lρ, and at frequencies df other than the above, there is no penetration. Since no magnetic flux is obtained, the magnetic path shown in FIG. 2 1aJ is not slid.

As described in detail of the H9 invention, the present invention provides a U-shaped break on the conductor of the inductor so as to face the surface of the plate material to be heated, and on the back side of the edge portion of the plate material. The magnetic induction 7af is provided at a position facing the inductor, and the frequency a of the power supplied to the inductor is set to t < (50,3/l)・ρ, so when the material to be heated is a non-magnetic material However, a magnetic path is formed at the edge via the magnetic induction 7A, and the magnetic flux density at the edge increases, so a drop in heating temperature at the edge is prevented and the temperature distribution in the width direction of the plate is made uniform. It will be planned. The above effect solves the problem of performing core heating on a plate material in a non-magnetic state.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of a heating four-ring device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a magnetic path of alternating magnetic flux in an actual gun example. FIGS. 3 and 4 are diagrams showing embodiments according to the prior art. 1...Inductor, 2...Magnetic induction 7A% 3...U
shaped core, 5...power supply for induction heating, 6...plate material (heated material)%φ...alternating magnetic flux, 1...induction [@1. f-
1W source frequency (b), t...thickness of heated plate material (m/m
), ρ... Specific resistance of heated plate material (μΩ・clh). Figure 3 (&) 'v11 Figure 4 (-) Figure 3 (b) Figure 4 (b)

Claims (1)

[Claims] In an induction heating method for heating the width direction of a non-magnetic material or a plate in a non-magnetic state as a material to be heated, an inductor in which a U-shaped core is covered with a conductor extending linearly in the width direction of the plate material. is provided facing the surface of the plate material, and a magnetic induction core is disposed on the back side of the edge portion of the plate material at a position facing the inductor, so that the frequency f (Hz) of the power supply supplied to the inductor is When the thickness of the plate used as a heating material is t (m/m) and the specific resistance of the plate is ρ (μΩ・cm), f<(50.3/
t) An induction heating method characterized in that ^2・ρ.