JPS5814034B2 - Dice-type induction heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a die-type induction heating device for inductively heating a metal die used for extrusion molding of aluminum or the like through a low-frequency alternating current.

Since it is inconvenient to transport the die alone, it is generally stored in a ring-shaped holder and transported, and when the die is cold, the extruded material is cooled and the surface layer is hardened, so the extruded material In order to prevent the surface layer from curing, the die must be preheated before being installed in the extruder.

When heating such a die shape using an induction heating device, conventionally, even if the holder is made of magnetic steel, the heating coil 3 is heated while the die shape 1 is housed in the holder 2, as shown in FIG. It was placed on an axially movable trolley 4 and inserted into the center of the heating coil 3, and heated by the electromagnetic induction effect of the alternating magnetic field generated by the heating coil 3, but due to the skin effect, only the outer holder 2 Since the die mold 1 that should be heated is hardly heated, it takes time to heat the die mold 1 and has the disadvantage of poor efficiency.

Further, in order to eliminate such drawbacks, the holder 2 may be made of non-magnetic steel such as stainless steel, but the material cost of the holder 2 increases, resulting in a high price.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a method for induction heating a die type, which can heat the die type at a uniform temperature in a short time regardless of the material of the holder.

In order to achieve the above-mentioned object, the present invention is an apparatus for induction heating a die mold held in a holder using a heating coil. By providing a lifter that is provided directly below the center of the heating coil and moves up and down, and a rotary table that is provided at the tip of the lifter and has an outer diameter smaller than the inner diameter of the holder and mounts only the die mold,
When a die mold housed in a holder is placed in an induction heating coil and subjected to induction heating, the die mold is taken out from the holder and only the die mold is placed in the induction heating coil to be induction heated, and after heating is completed. , the die mold is stored in the holder again.

Embodiments of the present invention will be described below based on the drawings.

2 to 4 show the heating process of the die mold according to the present invention.

The heating coil 23 for inductively heating the die mold 1 is divided into left and right parts at the center and is formed to be openable and closable. In the closed state shown in FIG.
4 are connected in series.

The die mold 1 housed in the ring-shaped holder 22 has a pair of heating coils 23a in an open state, as shown in FIG.
23b, the pair of heating coils 23 are removed from the holder 22 by a lifter 25 such as a cylinder, as shown in FIG. 3, and only the die 1 is separated.
Then, as shown in FIG. 4, the left and right heating coils 23a and 23b are brought into a closed state, joined in series at the dividing portion 24, and induction heating begins.

The die mold 1 is placed on a rotary table 26 provided on the top of a lifter 25, and is rotated only during heating.

After the heating is completed, the left and right heating coils 23a and 23b are connected to the divided portion 2.
The die mold 1, which is heated by the lowering lifter 25, is again stored in the holder 22 and carried out, as shown in FIG.

The holder 22 is not shown from the time when the die mold 1 stored in the holder 22 is carried in directly under the heating coil for heating until the dice mold 1 is stored in the holder 22 again after heating and is taken out. It is maintained in a known manner.

In this embodiment, when the die 1 housed in the holder 22 is carried in directly below the coil, it is desirable that the attachment/detachment direction of the holder 22 and the die 1 be perpendicular.

At that time, the direction in which the die mold 1 is removed from the holder 22 (or the direction in which it is stored), the direction in which the die mold 1 is removed (or the direction in which it is stored), and the heating coils 23a, 23
These four operations are performed by one lifter 25, since the direction of lifting to the center part of b (or the direction of descending from the center part) is the same.

Therefore, the construction of the device is simplified and the entire process is short-circuited.

Further, since the lifter moves up and down, it is advantageous in terms of gravity when mounting the die mold 1 on the rotary table 26.

Note that the lifter 25 may be disposed directly below the coil, and the die mold 1 may be carried in and out from above the coil.

Further, since the center axes of the rotary table and the die 1 are perpendicular to the center axis of the heating coil, that is, the direction of the alternating magnetic flux, the die 1 is heated evenly throughout, in accordance with the known principle of induction heating.

That is, if only the center axis of the heating coil is made vertical in the state shown in FIG. 4, there is no need to divide the heating coil into two, but the rotary table becomes meaningless and uniform heating becomes impossible.

As described above, according to the present invention, the die mold 1 is removed from the ring-shaped holder 22, inserted into the heating coil, and heated by induction, so that the thermal efficiency is improved regardless of whether the holder 22 is made of magnetic steel or non-magnetic steel. It can be heated at a uniform temperature in a short time.

In addition, since the holder 22 is not heated to high temperatures, there is less wear and tear.
It also has the advantage of being manufactured from inexpensive magnetic steel.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing a conventional die-type induction heating method.
2 to 4 are process diagrams showing the heating method according to the present invention. 1... Dice type, 22... Holder, 2
3, 23a, 23b...Heating coil.

Claims (1)

[Claims] 1 In a device that induction heats a die mold held in a holder by a heating coil, a pair of heating coils that are divided into two in the horizontal axis direction and open and close on the left and right, and a pair of heating coils installed directly below the center of the pair of heating coils are used. A die-type induction heating device comprising: a lifter that moves up and down; and a rotary table provided at the tip of the lifter and having an outer diameter smaller than the inner diameter of the holder and mounting only the die-type.