JPH07197117A - Coil body in induction hardening deice - Google Patents

Abstract

PURPOSE:To improve a coil body composed of a coil for heating a work and cores for supporting this coil in an induction hardening device. CONSTITUTION:The surfaces of the cores 10 in the coil body in the induction hardening device is coated with a film 13 having heat resistance and alkali resistance to shut off the radiation heat from the heated work. After heating, the infiltration of a weak alkaline water soluble hardening agent sprayed in the heated surface of the work is prevented. Then, this film 13 is formed by applying or baking coated material mainly containing a phenol resin. Further, the upper core 10a and the lower core 10b are provided with the coil 11 in between and joined part between the coil 11 and the core 10 is sealed with the sealing agent 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a coil body comprising a coil for heating a work and a core supporting the coil in an induction hardening apparatus.

[0002]

2. Description of the Related Art Conventionally, as a technique for improving the durability of a core in a coil structure having a coil for heating a work and a core for supporting the coil in a high-frequency heating apparatus, for example, Japanese Patent Application Laid-Open No. Hei 10-242242 3-2663
A structure like No. 91 is known.

In this technique, in order to prevent the core from deteriorating due to radiant heat from the work heated by the coil, a cooling water circulation groove is provided at a portion facing the hardened surface of the core, and the core itself is cooled by the cooling water. It is cooled and its surface is covered with a heat-resistant lid.

[0004]

However, in the above technique, it is necessary to provide a cooling water circulation groove at a position facing the workpiece quenching surface, and to cover the surface with a heat-resistant lid, which makes the shape complicated. Alternatively, there is a problem that it is difficult to apply to a core that is small.

When the apparatus is a quenching apparatus, the work is heated and then a cooling medium such as cooling water is sprayed on the heating surface of the work to quench the work. This cooling medium is generally used. In the case of a weakly alkaline water-soluble quenching agent, the deterioration of the core is accelerated by the sprayed water-soluble quenching agent.

That is, in general, the core is a porous body formed by mixing a ferromagnetic powder and an insulating material with a binder, and molding and sintering the mixture. When the weakly alkaline water-soluble quenching agent penetrates into the core, it reacts with the binder. This is because it weakens the binding action.

[0007]

In order to solve such a problem, the present invention does not perform complicated processing and can be applied under various conditions (type of target work, size thereof, cooling medium, etc.) to prevent core deterioration. As a result, the surface of the core holding the coil is coated with a coating having heat resistance and alkali resistance. Further, this coating was formed by applying a paint and baking it. Also, the coil was adhered to the core through the coating. Further, a pair of cores is provided with the coil sandwiched, and the joint between the coil and the core is sealed with a sealant.

[0008]

[Function] Since the core surface is covered with a heat-resistant and alkali-resistant coating, the influence of radiant heat from the work can be blocked and the penetration of the water-soluble quenching agent can be prevented.

[0009]

Embodiments of the coil body of the induction hardening apparatus of the present invention will be described with reference to the accompanying drawings. 1 to 3
4 is a partially enlarged view showing a configuration example of a coil body, FIG. 4 is a longitudinal sectional view of a main part of the quenching device, FIG. 5 is an explanatory view of the quenching device in plan view, and FIG. 6 is an exploded perspective view of the quenching device. .

The induction hardening apparatus of the present invention is configured as a device for hardening the inner peripheral surface of a cup-shaped work W as shown in FIG. 4, for example, and a center pillar 2 attached to a support 1. A coil body 3 mounted on the center pillar 2 is provided.

That is, as shown in FIG. 6, three protrusions 4, ... Are provided on the side surface of the center pillar 2, and a cooling jacket 5 is attached to the upper portion of the protrusion 4, and The coil body 3 is attached to the cooling jacket 5 by hollow bolts 8 via upper and lower spacers 6 and 7 (FIG. 4).

The coil body 3 comprises a core 10 and a coil 11, and the core 10 is divided into an upper core 10a and a lower core 10b as shown in FIG.

The coil 11 is a pipe made of copper and having a rectangular cross section. The heating surface 11a at the upper three places can be made to face the quenching surface of the work W, and the inside of the pipe is Cooling water for cooling the coil 11 itself is circulated.

The core 10 is formed by mixing a ferromagnetic powder and an insulating material with a binder, molding and sintering, and is a porous body.

The lower core 10b and the upper core 10a
The coil 11 is set so as to be sandwiched by.

A quenching coolant flow passage 2a is provided at the center of the center pillar 2 so that it can be communicated with the hollow bolt 8 and the overhanging portion 4 has a flow passage for cooling water or the like. 4 a is provided and communicates with the inside of the cooling jacket 5. A passage 5a as shown in FIG. 4 is formed in the cooling jacket 5, the passage 5a communicates with a gap 12 formed between the cooling jacket 5 and the spacer 7, and the gap 12 is formed on the outer surface. It has an opening e that opens toward the front.

That is, the cooling water or the like that has passed through the flow passage 4a of the overhanging portion 4 is introduced into the cooling jacket 5 to cool the lower surface of the core 10, and then flows out from the opening e of the gap 12.

When the work W is heated and then quenched, the quenching coolant that has passed through the flow passage 2a in the center of the center pillar 2 is sprayed from the upper portion of the hollow bolt 8 onto the heating surface of the work W.

By the way, a coating 13 having heat resistance and alkali resistance as shown in FIG. 1 is formed around the core 10 of the coil body 3 of the present application.

In the case of the example, the coating 13 is formed by applying a heat-resistant coating material containing organosilicon whose main component is a phenol resin, and then baking it at about 280 ° C. for about 20 minutes. The coating 13 has heat resistance and alkali resistance.

The coating 13 is formed on the upper core 10a.
Of the upper and lower cores 10a, 1 which are coated with the coating 13 in this manner.
The coil 11 is sandwiched between 0b.

A sealant 14 is applied to the joint between the core 10 and the coil 11 to seal the gap. That is, this is to prevent the quenching coolant from entering through the gap.

In the quenching apparatus configured as described above,
Quenching is performed by bringing the coil 11 close to the quenching surface of the work W. At this time, even if radiant heat is radiated from the heated work W, the core 10 is protected from the heat by the coating 13.

When the heating is finished, the center pillar 2
A weakly alkaline water-soluble quenching agent is sprayed onto the heating surface of the work W from the central flow passage 2a.

Here, as other means of the quenching coolant, for example, use of cooling water or cooling oil can be considered, but the cooling water has a limited cooling capacity, and the surroundings become contaminated with cooling oil. Therefore, in the present proposal, a generally widely used weakly alkaline water-soluble quenching agent is used.

When such a weakly alkaline water-soluble quenching agent is sprayed onto the heating portion of the work W, the core 10 is also exposed to this quenching agent, but the surface of the core 10 has alkali resistance. Since it is covered with the film 13, it is possible to effectively block the permeation. In addition, the sealant 14 more firmly prevents the intrusion.

That is, the coating 13 can effectively prevent deterioration due to radiant heat and deterioration due to penetration of the water-soluble quenching agent.

Next, FIGS. 2 and 3 show another configuration example.

In this case, the core 10 is integrated, and in the case of FIG. 2, a concave portion for accommodating the coil 11 is formed, and the coil 11 is accommodated and adhered in this concave portion. In the case of FIG. The coils 11 and 11 are bonded together.

Also in this case, the coating 13 is provided on the entire surface around the core 10. However, when the coil 11 is bonded, it is better to bond it through the coating 13 rather than directly to the core 10 which is a porous body. There is also an effect that the adhesive effect is high.

[0031]

As described above, in the coil body of the induction hardening apparatus according to the present invention, the surface of the core holding the heating coil is covered with the coating having heat resistance and alkali resistance. Radiant heat can be effectively shielded, and deterioration due to the penetration of the quenching coolant can be effectively prevented. Further, in addition to having a simple structure, it is convenient because a core having a complicated shape or a small size can be easily applied.

[Brief description of drawings]

FIG. 1 is a partially enlarged view showing a first configuration example of a coil body.

FIG. 2 is a partially enlarged view showing a second configuration example of a coil body.

FIG. 3 is a partially enlarged view showing a third configuration example of a coil body.

FIG. 4 is a vertical cross-sectional view of a main part of a quenching device

FIG. 5 is an explanatory view of the quenching device in plan view.

FIG. 6 is an exploded perspective view of a quenching device.

[Explanation of symbols]

 3 coil body 10 core 10a upper core 10b lower core 11 coil 13 coating 14 sealant

Claims (4)

[Claims] 1. A coil body of an induction hardening apparatus comprising a heating coil and a core holding the heating coil, wherein the surface of the core is coated with a coating having heat resistance and alkali resistance. Coil device 2. The coil body for an induction hardening apparatus according to claim 1, wherein the coating film is formed by applying a paint and baking the paint. 3. The coil body of the induction hardening apparatus according to claim 1, wherein the coil is bonded to the core via the coating. 4. The pair of cores are provided so as to sandwich the coil, and the joint between the coil and the core is sealed with a sealant.
The coil body of the induction hardening apparatus described in.