JPS62160687A - Heating coil for electromagnetic cooker - 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 application field) The present invention relates to a heating coil for an electromagnetic cooker.

(Prior art) In general, a heating coil for an electromagnetic cooker is a coil made by stranding insulated wires or spirally wound wires on a plastic coil stand (1), for example, as shown in Figure 1 below. (2
) is fixed with impregnated varnish. The lead wire portions (3) and (4) also use the same Ritz wire as the coil portion (2).

In the above, the impregnated varnish for bonding the coil (2) and the coil stand (1) must have high heat resistance, and when applying the varnish, there must be sufficient space between the windings of the coil and between the coil and the coil stand. It needs to have good fluidity because it needs to penetrate into the liquid. Therefore, for example, epoxy-based or polyester-based impregnated varnishes are used.

(Problems to be Solved by the Invention) These varnishes have very high hardness after curing, but almost no elasticity. Therefore, when the varnish applied near the base of the lead wire penetrates into the lead wire portion due to capillary action and hardens, the IJ-wire hardens and becomes rod-shaped, making it difficult to connect to the power circuit. In order to prevent the above-mentioned phenomenon, it may be possible to reduce the amount of varnish applied near the base of the lead wire, but in this case, the adhesive force may become weak and the coil may peel off from the coil stand.

In view of the above, the present invention has been developed to solve these problems.

(Means for Solving the Problems) That is, the heating coil of the present invention consists of a coil made of a stranded insulated litz wire wound spirally on a coil base made of plastic or the like, and coated with impregnated varnish. In a fixed electromagnetic cooking heating coil, a varnish that has low fluidity or hardens in a short time even at high temperatures is applied near the beginning and end of the coil, and the coil is fixed on the coil stand. It is characterized by having a flexible lead wire that prevents impregnated varnish from penetrating into the lead wire portion that continues at the beginning and end of the coil winding.

The present invention will be explained in detail below with reference to FIG. 1 as an example.

In the parts (A) and (B) near the base of the lead wire, unlike other parts, a varnish that does not have fluidity even at high temperatures or has a short curing time (short hardening time) is applied. The other parts were coated with an ordinary impregnated varnish with good fluidity, and then heated and cured.

(Function) Varnish @ itself has low fluidity, so it does not penetrate into the lead wire part, and it can also prevent impregnated varnish ■ from penetrating into the lead wire part, or because Varnish @ has a short curing time. Since the varnish hardens before it begins to penetrate, it is possible to prevent the varnish from penetrating. This results in a heating coil with flexible lead wires. In addition, since the impregnated varnish (2) can be sufficiently applied near the base of the lead wire without worrying about it penetrating into the lead wire portion, sufficient adhesive strength between the coil and the coil stand can be ensured in that area.

Examples of varnishes that do not have fluidity or harden in a short time even at high temperatures include epoxy-based or polyester-based varnishes, particularly thixotropic varnishes.

In the present invention, the expression "low fluidity" or "cures in a short time" means that either one or both may be used.

(Effect of the invention) According to the present invention as described above, there are the following effects.

■Since the impregnated varnish is sufficiently applied to the coil part near the base of the lead wire, the adhesion between the coil and the coil stand is strong.
There is no risk of the coil peeling off, especially near the base of the lead wire.

■The lead wire is flexible because the varnish with high viscosity, short curing time, and thixotropic properties is applied near the base of the lead wire to prevent the impregnated varnish from penetrating into the lead wire portion.

[Brief explanation of drawings]

FIG. 1 illustrates an explanatory plan view of the heating coil of the present invention. (1)...Coil stand, (2)...Coil, (3),
(4)...Lead wire, (A), (B)...Near the base of the lead wire Figure 1 Procedural amendment document March 4, 1985 1, Indication of the case 1986 Patent Application No. 002627 λ Title of invention f no 11'l JEk + p 7a, il
- Koi ν3, Relationship with the person who makes the amendment Special;'t'r:, +! Applicant 4, Agent 1) The seventh line from the top of page 4 of the specification is corrected to ``(short curing time) J'kr (short curing time).

Claims (2)

[Claims] (1) For example, in a heating coil for an electromagnetic cooker, a coil made of a spirally wound Litz wire made of twisted insulated windings is fixed on a coil stand made of plastic or the like with impregnated varnish. A varnish that has low fluidity or hardens in a short time even at high temperatures is applied near the beginning and end of the winding, and the impregnated varnish that fixes the coil to the coil stand is applied to the lead wire portion that continues at the beginning and end of the coil. A heating coil for an electromagnetic cooker characterized by having a flexible lead wire that prevents penetration. (2) The varnish that impregnates and fixes the coil on the coil stand is one selected from the epoxy-based and polyester-based groups,
Electromagnetic cooking according to claim (1), wherein the varnish that has low fluidity or hardens in a short time even at high temperatures is an epoxy-based or polyester-based varnish selected from the group of thixotropic varnishes. Dexterity heating coil.