JPS62133693A - 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 [Field of Industrial Application] The present invention relates to an electromagnetic cooking device, and particularly to one that eliminates the temperature difference between the center and the outer circumference of an induction coil.

[Conventional technology]

Conventionally, regarding the induction coil a of the electric 81 cooker, for example,
As described in Jitsutikaku No. 56-26895, a vertical cross-sectional view of the coil and its temperature distribution diagram are shown in FIG. 9 and FIG. 1O.

In Fig. 9, the induction coil a is an induction coil a1 having a linear cross-section, that is, a flat plate, with respect to the plate a on which the pot C, which is the object to be heated, is placed. In Fig. 10, the distance between the pot C and the coil a2 is approximately 1/3 of the center of the distance between the center and the outer periphery of the induction coil a2. The cross section of the coil a2 is formed into a W-shape so as to be maximum.

Therefore, by applying a high-frequency current to the induction coil a, magnetic flux is generated and heats the mounting plate b and eventually the pan C. In the case of Fig. 9, the temperature change at the bottom of the pot with respect to the distance from the center of the coil is shown. As you can see in the graph, that temperature! Contrary to the fact that the mouth has an M-shape with large undulations, in the case of Fig. 10, the induction coil a2 has a W-shaped cross section, so the magnetic flux density is made uniform and the temperature distribution at the bottom of the pot is as shown in the graph.
It becomes approximately equalized.

[Problem that the invention seeks to solve]

Since the conventional induction coil is configured as described above, if it is formed into a flat plate shape, there is a drawback that temperature unevenness becomes large. In addition, in the case of a W-shape that eliminates this drawback, the distance between the induction coil and the bottom of the pot increases on average, which not only causes a significant decrease in heating efficiency but also
This W-shaped induction coil is not used at all because of the problem that the W-shaped induction coil requires a large installation space.

[Means for solving problems]

In view of the above circumstances, the present invention aims to provide an induction coil that can eliminate temperature unevenness without expanding the installation space and also improve mass productivity.

Therefore, the induction coil of the electromagnetic cooker according to the present invention is
Conductive plates and heat-resistant insulating plates made of spiral copper foil are alternately laminated and integrated, and the density of the spiral copper foil is coarser in the center and denser closer to the outer periphery. It was designed to be.

[Effect]

With the above configuration, the magnetic flux density crossing between the pot and the induction coil becomes uniform, so the temperature distribution at the bottom of the pot becomes uniform.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained based on FIGS. 1 to 5.

First, I will explain the configuration.

FIG. 1 is a perspective view of an induction coil 1 installed in a large-sized electromagnetic cooker (not shown) of the wooden embodiment, and FIG. 2 is a partially exploded view of the large-sized induction coil 1.

FIG. 3 is a sectional view taken along line mm in FIG. 1, and FIG. 4 is a front view of the induction coil l installed in the large-sized electromagnetic cooker.

In the figure, the induction coil l is formed in the shape of a disk, and can be assembled integrally by layering a plurality of IXi layers of insulating sheets 2 and conductive plates 3 alternately from the top surface and ending with the insulating sheet 2 from the bottom surface. be.

The insulating sheet 2 has heat resistance, has a thickness of about 50 μm,
The external dimensions are the same as those of the conductive plate 3.

The conductive plate 3 has a thickness of approximately 20 gm, and includes a coiled strip-shaped copper foil 3a with a width of 2 mm, and a heat-resistant strip of copper foil 3a arranged between and around the coiled copper foil 3a. and an insulator 3b.

In the spiral copper foil 3a, the spacing between adjacent copper foils 3a becomes smaller from near the center of the conductive plate 3 toward the outer periphery, and as a whole, the center is coarse and the outer periphery is dense. has been done.

In the induction coil l formed by laminating these, the inner end of the copper foil 3a, which is the center of the spiral, is electrically connected by a connecting wire 4 that penetrates the laminated layers, and the outer end is also electrically connected by a connecting wire. , are connected to lead wires 5.5, respectively.

Next, we will discuss the effect.

When a high frequency current is supplied to the induction coil 1, a magnetic flux is generated between the pot pot and the induction coil 1, and an eddy current is generated in the pot pot bottom, thereby heating the pot pot bottom. In this case, the magnetic flux density is uniform because the arrangement density of the copper foil 3a of the electrocardiographic board 3 in the induction coil l is made coarser from the outer periphery to the center, and the magnetic flux density is uniform. Since the eddy current is also uniform, the amount of heat generated is also uniform. Therefore, the temperature at the bottom of the pot becomes uniform and constant throughout, as shown in FIG. That is, the temperature of the heated portion located above the induction coil 1, such as the holder a and the bottom of the pot, is always uniform as long as it is above the induction coil 1.

In the above embodiment, one disk-shaped induction coil 1 is constructed of the same type of conductive plate 3, but several types of conductive plates with different mutual spacings of the spiral copper foils 3a are prepared. An induction coil may also be used to obtain a uniform temperature.

In addition, for the rectangular electromagnetic cooker 10 as shown in FIG. 6 as another embodiment, a rectangular plate-shaped induction coil 11 is used as shown in FIGS. 6 and 7, and a rectangular plane A heat-resistant insulating sheet is formed by using a rectangular conductive plate 13 formed by densely disposing copper foil 13a formed in a rectangular spiral shape around the outer periphery and sparsely disposing the central part, and applying an insulator 13b. 12
By alternately stacking the coils and arranging the coils in substantially the same manner as the disk-shaped induction coil 1, the same effect as in the embodiment described above can be obtained.

〔Effect of the invention〕

As explained above, in this invention, the induction coil is a laminated type, and the copper foil is spirally arranged in the conductive part so that the center is rough. Therefore, there is no risk of deterioration in heating efficiency, and there is an effect that not only can the occurrence of uneven baking be eliminated, but also that mass productivity can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a large induction coil installed inside a round electromagnetic cooker according to an embodiment of the present invention, FIG. 2 is a partially exploded view of the same large induction coil, and FIG. I[I in Figure 1
-III line sectional view, Figure 4 is a front view of a large induction coil installed in a 5-round electromagnetic cooker, and Figure 5 shows the temperature at the bottom of the pot from the center of the induction coil to the outer periphery. The graph shown in FIG. 6 is a perspective view of a square electromagnetic cooker according to another embodiment, and FIG. 7 is a perspective view of a square induction coil.
9A is a sectional view of a flat induction coil installed in a conventional electromagnetic cooker, and FIG. 9B is a graph corresponding to FIG. 5. FIG. 10A is a sectional view of a W-shaped induction coil installed in a conventional electromagnetic cooker, and FIG. 10B is a graph corresponding to FIG. 5. 1.11... Induction coil 2.12... Insulating sheet 3.13... Conductive plates 3a, 13a... Copper foil 3b, 13b...・・・Heat-resistant insulator b・・・・・・Revision plate Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. ts9 Fig. 10

Claims (1)

[Claims] The induction coil, which is installed internally facing the mounting plate, is integrated by alternately laminating a conductive plate made of copper foil in a spiral shape and coated with a heat-resistant insulating material, and a heat-resistant insulating sheet. An electromagnetic cooking device characterized in that both ends of the copper foil are electrically connected to each other, and the copper foil is arranged so that the density of the copper foil becomes denser from coarser to denser from the center to the outer periphery.