JPS62246284A - Crossing magnetic field type induction heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a crossed magnetic field type induction heater, and particularly to a crossed magnetic field type induction heater that is equipped with an auxiliary heater in addition to a main heater and is suitable for heating non-magnetic thin plate materials. Regarding heaters.

Conventional technology: In addition to the main heater, it is equipped with an auxiliary heater, which overcomes the drawback that if the main heater alone is used, the temperature near the ends of the object to be heated is low in the width direction of the object, making it impossible to achieve uniform heating. In order to solve this problem, a cross-magnetic field type induction heater is disclosed, for example, in Japanese Patent Application Laid-Open No. 10-221986, which uses an auxiliary heater to perform corrective heating on this part to obtain a uniform temperature distribution as a whole.

However, in this device, the main heater has four magnetic poles (N, S) extending across substantially the entire width of the object to be heated, perpendicular to the central axis along the moving direction of the object to be heated.

N, S) is used as one unit, and an auxiliary heater is arranged downstream of the main heater in the direction of movement of the object to be heated, and both are used to heat the object. Most of the power (70-90%) will be supplied to the main heater. Therefore, as a result of being heated intensively by the main heater, the temperature difference between the widthwise center of the object to be heated and the vicinity of its edges also increases depending on the heating power, especially when the object to be heated is a thin plate material. , /8 distortion occurs, causing displacement of the thin plate material in the direction of the gap between the main heaters above and below the thin plate, which causes deformation due to thermal strain until it passes through the auxiliary heater that is to be subjected to corrective heating next. There is. In addition, the structure of the auxiliary heater is such that when each excitation coil is housed and wound in a slot provided in the iron core parallel to the central axis of the object to be heated, it becomes a rectangular spiral parallel to the surface of the object to be heated. This has the disadvantage that the structure is complicated and the winding of the coil is complicated.

Problems to be Solved by the Invention It is an object of the present invention to provide a crossed r magnetic field type induction heater that does not cause large thermal strain on the object to be heated due to rapid concentrated heating of the main heater.

Means to solve the problem: The main heater, which had a conventional four-magnetic-pole configuration, was divided into two parts, and it had N-pole and S-pole magnetic poles and their related excitation coils, with the object to be heated sandwiched between them. A plurality of pairs of main heaters arranged vertically are arranged alternately with at least one pair of auxiliary front heaters along the moving direction of the object to be heated.

Each pair of main heaters distributed along the moving direction of the object to be heated with the pair of auxiliary heaters in between heats the object to be heated in multiple stages. Heating and correction heating by the auxiliary heater are performed alternately.

Embodiment FIG. 1 is a side view of an embodiment of the crossed magnetic field type induction heater of the present invention, which includes two main heater pairs 1a and 1b and an auxiliary heater pair 2 disposed between them. , and each pair of main heaters 1a and 1b is composed of two main heaters 10. of the same structure disposed above and below the object to be heated, for example, a plate 3.
11 are paired. The auxiliary heater pair 2 is also made up of a pair of upper and lower auxiliary heaters 20 and 21 having the same structure. The structure of the main heaters 10.11 is similar to the conventional 8" Jii described above, except that each consists of two magnetic poles (N and S), and each magnetic pole has an excitation coil 13. 14 is wound, and an alternating magnetic field is generated from each magnetic pole by an applied alternating current.

The structure of the auxiliary heaters 20 and 21 is different from that of the auxiliary heaters used in the above-mentioned conventional crossed magnetic field type induction heater.

The method of winding the excitation coil housed in each slot around the iron core is different. FIGS. 2A, B, and C show a top view, a side view, and a cross-sectional view of the pair of auxiliary heaters 2, where the main heater is near the widthwise end of the plate 3. An excitation coil 23 is housed in each slot 24 formed at a position on the iron core 22 of the auxiliary heater so as to cover two locations symmetrical with respect to the central axis X of the auxiliary heater. After extending along the core 22, it is attached to the core 22 along the back surface of the core 22 in a winding shape. Therefore, the excitation coil in each slot does not contact, overlap, or intersect with other excitation coils laterally or above and below, and is separated and independent for each slot, making the winding work easy.
Also, the structure is simple. In addition, unlike the conventional rectangular spiral coil, the coil portion that crosses the plate 3 in the width direction W from one slot in the width direction W of the plate 3 to the slot on the other side is unnecessary, and the structure is simple. The materials are also adjusted. External terminal 2 is attached to each excitation coil wound in each slot.
5 are provided and connected to their respective power sources. As these power sources, those similar to those used in the above-mentioned conventional crossed magnetic field type induction heater can be used.

To explain the operation, 1. When the plate 3 moves in the direction of the arrow as shown in Fig. 1, the plate 3 is first heated by the pair of main heaters 1a, but compared to the conventional 4-pole configuration, the plate 3 is heated by the pair of main heaters 1a. Since it has a magnetic pole (two magnetic poles) configuration, the time for passing through the main heater, the heating time for 11 u, is approximately halved, and at this stage, the primary heating time, which has not yet reached the predetermined final temperature, and the plate material 3 are subjected to auxiliary heating. Since it passes through pair 2 of the maxillary p8 appliances, corrective heating is performed for areas that are not sufficiently heated by the maxillary p8 appliance. Board material 3 is
It then passes through the main heater pair 1b where it is heated to a predetermined final temperature. Therefore, conventionally, a pair of main heaters (
In this example, the plate material was heated rapidly and intensively while it passed through the 4-magnetic pole configuration to reach a predetermined final temperature. The two pairs of main heaters 1a and 1b perform heating to a predetermined final temperature in two stages with a correction heating period in between.

Therefore, thermal strain caused by rapid concentrated heating is also dispersed and reduced.

Also, excitation coil 2 for each slot of pair 2 of the auxiliary heater
3 is the above-mentioned conventional crossed magnetic field via the respective external terminals 25! ? By connecting to a control circuit similar to the power supply control circuit used in the A-conduction heater, the power supply can be controlled for each excitation coil, so that the desired heating portion of the plate material 3 can be individually Correction heating is possible, and more uniform temperature control is possible.In addition, the excitation coil 23 of the auxiliary heater has a width W of the object to be heated.
When is constant, it can also be provided only at predetermined locations.

Note 2: In the above embodiment, the conventional main heater is divided into small unit main heaters each having two magnetic poles and arranged in a distributed manner, but crossed magnetic field type induction heating including an auxiliary heater The overall length of the vessel can be made not much different from conventional ones.

FIG. 3 shows another embodiment of the invention, compared to the embodiment of FIG. 1, with the addition of auxiliary heater pairs 2a and 2C, each of which is a main heater pair! Before (upstream) and after (downstream) a and Ib
By adjusting the distribution of the heating power supplied to these heaters, more precise heating temperature adjustment can be achieved.For example, the first pair of auxiliary heaters 2a
approximately the amount of heating power supplied to all auxiliary heaters,
The next first pair of main heaters 1a is supplied with approximately the same amount of heating power as is supplied to all the main heaters, and the second pair of auxiliary heaters 2b is
Correction heating is performed at , power is supplied to the second main heater pair ib to reach a temperature close to the predetermined final temperature, and final temperature adjustment is performed at the last auxiliary heater pair 2C. The distortion can be minimized by

Effects of the Invention The main heater uses a plurality of pairs having a small number of magnetic poles, that is, two magnetic poles, and these are distributed so as to be arranged alternately with the auxiliary heaters. Since the object to be heated is heated in multiple stages to reach a predetermined final temperature, the object to be heated is not heated suddenly and intensively by the pair of main heaters, so that the object to be heated is heated in the width direction of the object. There is no large temperature difference between the two, and therefore thermal strain can be kept small. In addition, before the assistance in the middle of each heating stage by multiple pairs of main heaters,! The influence of the temperature difference due to 8rA can be corrected early, and a more uniform temperature distribution can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view of one embodiment of the cross-magnetic field type induction heater of the present invention, and FIG. 2, A, B, and C are a plan view, a side view, and a sectional view of the auxiliary heater in FIG. can be. FIG. 3 is a side view showing another embodiment of the invention. In the figure, +a, lb, respectively, the pair of main heaters, 2,...
,,Auxiliary heater pair. 3. Object to be heated (plate material) 10. Il,
,, 8 organs, 13, eyes, 1. Excitation coil, 2
0.2+, auxiliary heater 22), iron core,
23. , , , Excitation coil 24 , , ,
,,slot, 25. ,,,,,external terminal.

Claims (3)

[Claims] (1) In a cross-induction type heater having a main heater for inductively heating a conductive object to be heated by a crossed magnetic field, and an auxiliary heater for correcting and heating the insufficiently heated portion of the main heater, the main heater is , a plurality of pairs of main heaters are arranged above and below with the object to be heated in between, each having N-pole and S-pole magnetic poles and excitation coils associated with these magnetic poles; A crossed magnetic field type induction heater comprising at least one pair of auxiliary heaters arranged alternately with the pair of main heaters along the moving direction of an object. (2) In the cross-magnetic field type induction heater according to claim 1, the auxiliary heater has a position corresponding to a predetermined heating point in the width direction of the object to be heated in the moving direction of the object to be heated. A cross-magnetic field induction heater characterized in that salient poles and slots are formed in parallel in an iron core, and the excitation coil of each slot extends along the slot and is then wound along the back surface of the iron core. (3) In the cross-magnetic field type induction heater according to claim 1, the lamination directions of the iron cores of the main heater and the auxiliary heater are shifted by 90 degrees from each other. type induction heater.