JPS6229874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic induction heating coil that can significantly improve the heating efficiency of a heated object, and a method for manufacturing the same.

(Prior Art) Heating is used for various purposes. One of them is heating for drying, and heating for drying includes heating for fixing the paint after painting. Conventionally, as a heating method for drying paint after painting, it has been common to use a large number of heating lamps installed in a drying oven. When drying with a heating lamp in a drying oven in this way, there is no problem if the object to be heated is simple and large in shape.
Uniform drying will occur in all parts, but if the object to be heated is small and has a complicated shape, the parts that are hidden from the heat lamp side will be hidden from other parts. It is difficult to dry, and therefore it is difficult to achieve uniform drying.

(Problems to be Solved by the Invention) The problems to be solved by the present invention are as described above, even if the object to be heated is small and has a complicated shape, it can be heated efficiently and uniformly in a short time. The aim is to be able to heat the For this reason, electromagnetic induction heating is adopted as the heating method. By the way, in electromagnetic induction heating, a heating plate is placed inside a magnetic field whose direction changes alternately, as can be seen in cooking appliances.This heating plate is made to generate heat by eddy current, and the object to be heated is placed above it. The so-called indirect heating method is common. Therefore, this method cannot be directly applied to the small and complicatedly shaped object to be heated, which is the object of the present invention. The present invention has been made in view of this point.

(Means for Solving the Problems) The first invention of the present invention is a coil for electromagnetic induction heating, and the outer surface of the object to be heated is wrapped in accordance with the outer shape of the object to be heated. The second invention relates to a method of manufacturing such a coil.The coil is constructed by bonding a conductive wire in a spiral shape to the outer surface of a mold formed in a mold, and then thermally spraying ceramic on the back surface of the mold to which the conductive wire is bonded.The second invention relates to a method for manufacturing such a coil. A wooden mold with a shape almost similar to the shape of the object to be heated is combined with a fixing plate with a hole for inserting the wooden mold, and after applying a release agent to the wooden mold, a cloth or the like is tightly attached. The cloth or the like is hardened with varnish, etc., and then the conductive wire is wound in the circumferential direction of the wooden mold while being fixed with adhesive, followed by drying, and after the drying, the wooden mold is removed and molded, and after the molding,
This is a method of thermally spraying ceramic from the outer surface.

(Function) According to the method of the second invention, it is possible to obtain an electromagnetic induction heating coil that covers an uneven object to be heated, and the coil according to the first invention manufactured in this way can be used. For example, an object to be heated that is small and has a complicated shape can be uniformly and quickly heated by electromagnetic induction.

(Example) Next, an example of the present invention will be described using the drawings. It should be noted that the coil according to the first invention will be completed by implementing the second invention, so the description will focus on the second invention. In FIG. 1, numeral 1 indicates an object to be heated. In this embodiment, the object to be heated (1) is a shock absorber of an automobile. This object to be heated 1 includes a shaft portion 1a and a convex portion 1 for this shaft portion 1a.
b, 1c (therefore, the shaft portion 1a becomes a recessed portion). What is shown in Figure 2 is the object to be heated 1.
This is an electromagnetic induction heating coil (hereinafter referred to as a coil) 2 which has a shape similar to the shape of , and has a size that surrounds the object to be heated 1 . This coil 2 is
A conductive wire 4 is formed on the top of the fixing plate 3 by being hardened into the shape shown in the figure.

Next, the manufacturing order will be explained. First, as shown in FIG. 3, a wooden mold 5 having a shape almost similar to the shape of the object to be heated 1 is prepared. This wooden mold 5 is inserted into a fixing plate 3 (resin or baked plate) having a hole 6 for inserting the wooden mold 5 as shown in FIG. Make it. Then, a release material is applied to the surface of the wooden mold 5, and a cloth 7 is tightly attached thereon and hardened with varnish and resin (see FIG. 6). After that, as shown in FIGS. 7 and 8, the conductor 4 is attached to the wooden mold 3 while being fixed to the top surface with adhesive.
Wrap it circumferentially and dry. After drying, the wooden mold 5 is pulled out below the fixing plate 3 as shown in FIG. Then, as shown in FIG. 10, a coil 2 having an appearance similar to that shown in FIG. 2 is produced. This is completed by spraying ceramic 8 on the back side as shown in FIG.

In the above process, a plurality of twisted heat-resistant enamelled wires are used as the conducting wire 4. In this way, the current flowing through each wire can be made uniform, and the lines of magnetic force can be made dense. Furthermore, the natural cooling of the coil is faster than with a single wire, making it cost-effective. The conductor wire 4 is wound in the circumferential direction (spiral) of the wooden mold 3 so that the lines of magnetic force are directed in the same direction, so that magnetic energy is effectively used and the temperature distribution of the heated object 1 is uniform. Roll it loosely or densely depending on the shape of the heated object 1.

Thereby, the object to be heated 1 is heated uniformly in a short time, the thermal polymerization between the object to be heated 1 and the paint becomes uniform, and an appropriate coating thickness and strong adhesion are obtained.
The dimensions of the wooden mold 5 are 5mm around the entire circumference of the wooden mold 5.
Increase the degree. As the cloth 7, since this cloth 7 is used for heat resistance and insulation resistance, ceramic, Teflon, asbestos, etc. are used by coating or pasting.

The coil 2 manufactured in this manner is fitted around the outer periphery of the object to be heated 1 and is energized for use. The device for this purpose is an electromagnetic induction heater using a GTO thyristor. This is GTO
This is because by controlling the thyristor, the current flowing to the coil 2 can be easily changed, and the coil 2 of the present invention can be used with high efficiency. Note that since the coil 2 generates heat, it is preferable to cool it by air cooling or water cooling.

(Effects of the Invention) Since the present invention is a coil and a manufacturing method thereof as described above, it is compact and can be used for electromagnetic induction heating that can uniformly and quickly heat an object to be heated that has a complicated shape. This has the effect that the coil can be easily obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of an object to be heated, Fig. 2 is a perspective view of a coil for covering the object to be heated in Fig. 1, and Figs. 3 to 11 illustrate the steps of the method of the present invention. It is an explanatory diagram for explanation. 1...Object to be heated, 1a...Shaft portion (recessed portion) 1b,
1c...Protrusion, 2...Coil, 3...Fixing plate, 4
... Conductor, 5 ... Wooden pattern, 6 ... Hole, 7 ... Cloth, 8
... Ceramics.

Claims (1)

[Scope of Claims] 1. A conductor wire is spirally glued to the outer surface of a mold that is shaped to fit the outer shape of the object to be heated so as to cover the outer surface of the object to be heated, and the conductor wire is attached to the back side of the mold to which the conductor wire is bonded. An electromagnetic induction heating coil characterized by sprayed ceramic. 2. Combining a wooden mold with a shape almost similar to the shape of the object to be heated and a fixing plate with a hole for inserting the wooden mold, and after applying a release agent to the wooden mold, tightly attaching cloth etc. The cloth, etc. is hardened with varnish, etc., and then the conductive wire is wound around the circumferential direction of the wooden mold while being fixed with adhesive, then it is dried, and after the drying, the wooden mold is removed and molded. A method of manufacturing an electromagnetic induction heating coil characterized by thermally spraying ceramic.