JPS6116489A - 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 the Invention The present invention relates to an improvement in an induction heating device for heating the inner diameter of a cylindrical heated material, such as a steel pipe or a strip coil.

BACKGROUND ART One of the methods for heating the inner diameter portion of a cylindrical heated material, such as a steel pipe or slip coil, is an induction heating method.

This induction heating method is a method in which an iron core integrated with an excitation coil is inserted into a heating section 1 of a material to be heated, and the material to be heated is heated by electromagnetic induction.

Fig. 2 shows an example of the principle of a method in which a strip coil is used as a material to be heated and the inner diameter portion thereof is heated by induction.

I) When heating the inner diameter part of the strip coil 4, which is the material to be heated, - insert the iron core 3 integrated with the excitation coil 2 into the inner diameter part of the strip coil 4, and connect it to the induction heating device control panel 6. When the stored electromagnetic contactor 5 is closed and an arbitrary voltage and frequency f supplied by the power supply 1 are applied to the excitation coil 2, an electromagnetic induction effect 1 (from Joule heat is generated in the strip coil 4 and heated.

S) When heating the lip coil 4, the inner diameter part of the strip coil 4 is inserted into the iron core 3, so a part of the iron core can be divided. When heating, this dividing point is reconnected to create a closed magnetic path iron nob, but if the connection is poor, a gap will be created at the joint and the magnetic resistance will become thicker (and the alternating magnetic flux will increase). Decrease.

The conventional split core structure has a linear fixed core 3a on one side and a U-shaped movable core 31) on the other side, as shown in Figure 3, and has a cantilevered support structure with a strip coil 4.
The U-shaped movable iron core 3b is inserted and coupled into the inner diameter portion of the shaft.

When the width of the sharpening strip coil 40 is wide, the length in the width direction of the U-shaped iron core 3b becomes long, and bending occurs at the tip of the U-shaped core 3b, making it easy to create a gap at the joint portion. Further, when the strip coil 4 is inserted, a large space is required for the U-shaped iron core 3b to wait.

The structure and operation and effects of such a conventional induction heating device will be briefly explained.

Reference numeral 7 denotes a cart for moving the material to be heated, and the strip coil 4 is carried by this cart to a position to be heated.

The movable iron core 3b is provided within the machine frame 10 and is vertically moved by a motor 8. The movable iron core 3b is horizontally movably provided on rails 13 fixed to the carriages 1a, J, 1b, and is suspended from the carriage 12. ing. An excitation coil 2 is provided in a horizontal portion of the iron core 3b that is inserted into the inner diameter of the strip coil 1.

To insert the horizontal part into the inner diameter part of the coil 4, the cart 112.11b is moved up and down in the direction of the arrow Y, the rail 13 is moved, and height centering is performed to bring the iron core 3b to an appropriate position. Thereafter, the trolley 12 is horizontally moved in the direction of arrow Z at the horizontal movement position 9, the horizontal part having the excitation coil 2 is inserted into the inner diameter part of the strip coil 4, and the iron core 3b is coupled to the fixed iron core 3aK.

In this way, since the excitation coil 2 is placed on the horizontal part of the iron core 3+), the stiffness becomes long and the iron core 3bK deflects, which creates a gap at the joint with the fixed iron core 3a and closes it. The circuit will no longer be configured. This is a serious problem.

Problems to be Solved by the Invention The present invention solves the problems described above that may occur when the inner diameter of a cylindrical heated material is heated with an induction heating device having a splittable iron core forming a closed circuit. This is an attempt to eliminate the occurrence of voids in joints due to the occurrence of deflection in iron cores.

Means for Solving the Problems In the present invention, the dividable iron cores constituting the closed circuit are arranged opposite to each other (7) or two U-shaped iron cores having the same shape as Y, and two cores are provided. Each U-shaped core is heated to 4J.
An excitation coil is installed in the horizontal part of the heated coil, and the iron core is inserted into the inner diameter of the heating element at a predetermined position and connected to form a closed circuit. , solves the above problem.

Example Next, an example of the thermal power fabric of the present invention will be explained with reference to Figure 1.

In the figures, the same symbols as those appearing in the figures 2 and 3 have the same meaning.

That is, 4 is the strip coil which is the main heating target, 7 is the movable trolley, 10 is the machine frame, ]1a, 1]-b
1 is a vertically movable cart, 8 is its drive motor, and 13 is a rail.

Now, 3 a' + 3 b' is the strip coil 4
2a and 2b are excitation coils installed in the horizontal part inserted into the inner diameter of the strip coil 4 of the core. be. Each iron core 3a', 3b'
are the carts I2a that move horizontally on the rails 13,
It hangs down to 12b. -9a and 9b are trolleys respectively]
This is a device that horizontally moves 2a, 12b.

Next, the operation of the apparatus of this embodiment will be explained. The strip coil 4 is transported to a position where it is heated by a heated material moving cart 7 and is fixed therein. Next, the U-shaped iron core 3a is suspended from the trolleys 12a and 12b moving on the rail]3.
', 31)' and the excitation coils 2a, 21) are inserted into the inner diameter hole of the strip coil 1, and the vertically movable trolley 1]a, 1lb is moved up and down in the direction of the arrow Y by the motor 8. Move it to match the height of rail]3.

After that, the carts 12a, 12bK are hung with box-shaped iron cores 3a', 3b' and the excitation coil 2a.

2b as a horizontal movement device (e.g. hydraulic, electric cylinder)
Move horizontally in the direction of arrow Z with 9a and 9b,
As shown by the dotted lines, the split surfaces of both cores 3a'+31)' are accurately joined together to form a core forming a closed magnetic path, and the strip coil 4 is heated. When the heating is finished, horizontal moving devices a and 9b move the carts 12a and 12b in the opposite direction to uncouple the U-shaped cores 3a' and 3b'.
Move it to the standby position.

Effects of the Invention As is clear from the above explanation, in the device of the present invention, the waiting space is almost the same as the conventional one, the horizontal length of the movable core 3b can be halved compared to the conventional one, and the excitation coil 2 can also be divided in half. It is smaller, the moment generated at the cantilever and the support point of the iron core is about 2 times that of the conventional method, it can be made smaller with more flexibility, there is no gap in the joint, and the efficiency of induction heating can be increased.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of an example of the device of the present invention, Figure 2 is an explanatory diagram of an induction heating method for the inner diameter part of a strip coil,

Claims (1)

[Claims] (1) In an induction heating device that heats the inner diameter part of a cylindrical heated material having a split core constituting a closed circuit, two U-shaped cores of substantially the same shape are arranged facing each other, and the U-shaped core An excitation coil is provided in the horizontal part inserted into the inner diameter of the material to be heated, and when heating, the U-shaped iron core is connected,
An induction heating device characterized by an iron core forming a closed circuit.