JPS6255891A - Heating preventor for heat insulating material of 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 [Industrial Field of Application] The present invention relates to an insulating material heat generation prevention device for an induction heating device.

In general, devices using induction heating are widely applied in the fields of metal melting, heat treatment, brazing, pressure welding, etc., but the direct target of the present invention is induction heating type vacuum heat treatment equipment. This is a device or furnace that uses a heat insulating material such as graphite or carbon inside the heating coil.

[Prior Art] A conventional induction heating type vacuum heating device is shown in Fig. 7.
A heat insulating container made of a heat insulating material is arranged inside the induction heating coil a, the work C and the object to be heated d are housed in the heat insulating volume F5b, and the work C is heated by energizing the induction heating coil a.
heats the substance inside.

However, when the heat insulating container generates heat due to the induced current in the circumferential direction of the induction heating coil a, the temperature of the induction heating coil a outside the container also rises.

Since the heat resistance of the material used for insulating the coil a is generally lower than the heating temperature, insulation deterioration occurs.

Therefore, in conventional induction heating vacuum heating equipment,
The heat generated by the heat insulating container due to the induced current in the circumferential direction is reduced by cutting the heat insulating container into pieces e in the circumferential direction as shown in FIG. A method of preventing this was to assemble the parts between the two.

[Problems to be Solved by the Invention] However, since this method involves assembly, the mechanical strength is low and the processing is time-consuming. It is also conceivable that the resistance value of the insulator decreases due to the upper temperature limit, making it impossible to sufficiently interrupt the induced current.

An object of the present invention is to easily solve the above-mentioned problems in terms of processing while minimizing a decrease in the mechanical strength of the heat-insulating container.

[Means for Solving the Problems] That is, the present invention places a heat insulating material capable of accommodating the object to be heated inside an induction heating coil, and provides slits along the entire wall surface of the heat insulating material for the induction heating. This invention relates to a heat insulating material heat prevention device for an induction heating device, characterized in that a plurality of coils are provided at required intervals in the generatrix direction of the coil.

[For production]

Slits provided at required intervals around the entire wall of the insulation material block the induced current flowing in the circumferential direction through the insulation material, which prevents the temperature of the insulation material from rising and also prevents insulation deterioration of the induction heating coil. Ru.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of the present invention, which is an example of an induction heating type vacuum heating apparatus.

A heat insulating material 2 is installed in a vacuum chamber 1, and an induction heating coil 3 is wound around the heat insulating material 2.

The heat insulating material 2 is a cylindrical block that can be assembled in parts, and has a lid 4 and a bottom 5 on the top and bottom, and houses a workpiece 6 that is a heat generating element inside. It is.

A plurality of slits 8 are arranged on the outer peripheral wall surface of the heat insulating material 2 at predetermined intervals in the direction of the generatrix of the heat insulating material 2, which is a cylindrical block, that is, in the direction of the generatrix of the induction heating coil 3. The length, width, depth, etc. of the slit 8 can be adjusted as appropriate depending on the size of the heat insulating material 2, the container, etc.

With the above configuration, the induced current in the circumferential direction caused by the energization of the induction heating coil 3 is blocked by the slit 8, so that the heat insulating material 2 itself is prevented from generating heat, and the workpiece 6 is heated and the object to be heat treated is heated. 7 is heat treated.

The above principle is to block the eddy current 10 generated when the conductor 9 is inserted into the induction heating coil 3 using the slit 8 as shown in FIG. Since the eddy current 10 has a complicated distribution, the greater the number of slits 8, the greater the heat generation prevention effect. In addition, the magnitude of the eddy current 10 is maximum on the outer surface of the conductor 9 and becomes smaller toward the center. Can be blocked.

FIG. 5 shows another embodiment of the present invention, in which slits 11 are arranged alternately on the inner circumferential side of the split cylindrical heat insulating material 2 and with the slits 8 on the outer circumferential side, in a structure substantially similar to that of the previous embodiment.
This is an example where .

In the case of this embodiment, the inner slit 11 effectively works to block the eddy current 10 which has a low frequency and little skin effect,
The effect of preventing the heat insulating material 2 from generating heat is further enhanced.

The heat insulating material heat generation prevention device of the induction heating device of the present invention is not limited to the above-mentioned embodiments, and the shape of the insulating material and slits is not limited to a cylinder, but can also be shaped in a horizontal cross section as shown in FIG. It goes without saying that various changes can be made without departing from the gist of the present invention, such as arranging the divided blocks 13 so as to form a square slit 12 and prevent heat radiation from the heated workpiece. It is.

[Effects of the Invention] As explained above, the heat insulating material heat generation prevention device of the induction heating device of the present invention exhibits various excellent effects as described below.

(D) By making appropriate slits in the heat insulating material, it is possible to prevent the generation of induced current without using an insulator.

(2) Since heat generation of the heat insulating material can be prevented, deterioration of the insulation of the conductive heating coil (1) can be prevented.

■ Processing is easy as all you have to do is cut slits in the insulation material.

■ It is advantageous because the number of slits can be determined depending on the degree of heat generation of the insulation material.

(V) Because it is insulated by space, there is no temperature dependence.
Provides reliable insulation.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the device of the present invention, FIG. 2 is a view taken along the arrow II-I in FIG. 1, FIG. 3 is an explanatory diagram showing the installed state of the device of the present invention, and FIG. Fig. 5 is an explanatory diagram of another embodiment of the device of the present invention, Fig. 6 is an explanatory diagram of a modification of the device of the present invention, and Fig. 7 is a diagram of the conventional induction heating coil. An explanatory diagram showing an example of a type vacuum heating device, Fig. 8 (
8(a) and 8(b) are explanatory views showing an example of a conventional heat insulating container. FIG. 8(a) is a view showing the state before assembly, and FIG. 8(B) is a view showing the state after assembly. 1 is a vacuum chamber, 2 is a heat insulating material, 3 is an induction heating coil, 6 is a workpiece, and 8, 11, and 12 are slits. play

Claims (1)

[Claims] 1) A heat insulating material capable of accommodating the object to be heated is placed inside an induction heating coil, and a plurality of slits are provided on the entire wall surface of the heat insulating material at required intervals in the generatrix direction of the induction heating coil. A heat insulating material heat generation prevention device for an induction heating device, characterized by: