JPS62195888A - Induction heating 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 induction heating cooker that is used in combination with a pot mounting plate.

2. Description of the Related Art In general, in induction heating cookers, if the object to be heated deviates from the center of the heating coil, the thermal efficiency decreases.

There are problems such as an increase in radiated magnetic flux from the heating coil and the occurrence of radio wave interference.In order to solve this problem, two vanes are configured to detect when the object to be heated is shifted from the center of the heating coil. For example, it is known from Japanese Patent Publication No. 58-36472. This is a configuration diagram of the detection coil shown in FIGS. 5 and 6, that is, the detection coil 13a.

13b and 13c are arranged around the heating coil 12. And detection coils 13a, 13b.

The output voltage of 13c is applied to a detection circuit (not shown) whose main parts include a three-phase full-wave rectifier circuit and a voltage comparator, and the displacement of the object to be heated is detected from the output of the detection circuit. Note that 1o in the figure is a commercial power source, and 11 is the commercial power source 1o.
a frequency converter 14 connected to the heating coil 1;
This is the second support plate.

Problems to be Solved by the InventionIn recent years, in induction heating cookers in which an induction heating unit is incorporated into a table, etc., when the object to be heated is placed on the top plate of the table, etc. Because the top plate can be distorted or damaged due to radiant heat, conduction heat, etc., there is a tendency to use a pot holder in combination.

3 bae.

Here, when a pot mounting plate is used in conjunction with the induction heating cooker having the conventional configuration, even if the pot mounting plate is shifted from the center of the heating coil, as long as the object to be heated is in the center of the heating coil, the user can It does not issue a warning and cannot detect that the pot mounting plate has shifted from the center of the heating coil. Moreover, in order to detect that the object to be heated has shifted from the center of the heating coil, a complicated configuration such as three or more detection coils and a three-phase full-wave rectifier circuit is required. Furthermore, if the pot mounting plate of the induction heating cooker deviates from the center of the heating coil, the heating efficiency will decrease and the radiation magnetic flux from the heating coil will also increase, resulting in increased radio wave interference. Furthermore, if a small object such as a spoon or knife is placed on the upper surface of the heating coil at the position where the pot placement plate is displaced, it will be heated, causing problems such as burns.

The present invention solves the above-mentioned conventional problems, and aims to provide an induction heating cooker that can detect with a simple configuration that the pot mounting plate has shifted from the center of the heating coil.

Means for Solving the Problems In order to achieve this object, the induction heating cooker of the present invention has the following features:
A display pattern was provided that was made of a substance that changes color as the temperature rises (for example, paint that changes color as the temperature rises, trade name: Thermopaint). It has a configuration including a pot mounting plate provided with at least one magnetic body whose temperature increases due to the magnetic flux from the heating coil.

Effect With this configuration, if the pot placement plate deviates from the center of the heating coil, the temperature of the magnetic body increases due to the magnetic flux induced by the heating coil, and the display pattern provided on the magnetic body changes color, causing the pot placement plate to shift from the center of the heating coil. It is possible to detect that the plate has shifted from the center of the heating coil.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a table, which has a top plate 2 made of a heat-resistant plate, and an induction heating unit 7 provided at the bottom of the top plate 2. On top of the top plate 2, a pot 6t and a placing plate 3, which is made of a heat-resistant insulator and on which the object to be heated 4 is placed, is removably provided. The induction heating unit 7 includes a heating coil 7 that induces magnetic flux within the support housing 7a.
b. Further, the pot mounting plate 3 has a display pattern consisting of a magnetic body 6 whose temperature increases due to the magnetic flux from the heating coil 7b, and a paint that changes color as the temperature of this magnetic body 6 increases. In the above configuration, when the pot mounting plate 3 is located at the center of the heating coil 7b as shown in FIG. First, the display pattern 5 does not develop color. Also, as shown in Fig. 3B, the pot mounting plate 3 is connected to the heating coil 7b.
If it deviates from the center of the heating coil 7b, the magnetic flux induced by the heating coil 7b will cause the magnetic body 6 to generate heat, and the display pattern 5 will change color, indicating to the user that the pot placement plate 3 has deviated from the center of the heating coil 7b. Inform.

As described above, according to the present embodiment, a magnetic 6-base plate with an indication pattern made of paint that changes color as the temperature rises is used to indicate that the pot placement plate has deviated from the center of the heating coil. Detection can be performed with a simple configuration of attaching it to a mounting plate.

FIG. 4 shows another embodiment of the present invention, which includes a magnetic body 9a provided with a display pattern 8a made of paint that changes color due to temperature rise as shown in C in the figure, and a magnetic body 9a similar to the magnetic body 9a described above. It is characterized in that three magnetic bodies (not shown) having the following configuration are provided on the pot mounting plate. In the same figure, 8a, 8
b and 8c are display patterns made of paint that changes color as the temperature rises and is provided on three magnetic bodies other than the magnetic body 9a. When the pot mounting plate 3 is located at the center of the heating coil 7b as shown in A in FIG. 4, the magnetic flux induced by the heating coil 7b does not generate heat in any of the magnetic bodies, and the display pattern sa
, sb, sc, and sd do not change color and are still B in the same figure.
If the pot placement plate 3 is off the center of the heating coil 7b, the magnetic body 9a will generate heat due to the magnetic flux induced by the heating coil, and the display pattern 8a will change color, causing the user to be unable to place the pot on the pot. It is notified that the placing plate 3 has shifted from the center of the heating coil 7b.

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As described above, according to this embodiment, the pot mounting plate is placed at the center of the heating coil by providing the pot mounting plate with four magnetic bodies each having a display pattern made of paint that changes color as the temperature rises. If it deviates from the heating coil, one or two of the four display patterns will change color, and if you shift the pot placement plate in the direction of the discolored display pattern, you will be able to place the pot placement plate in the center of the heating coil. can.

The display pattern 5 is made of paint that changes color as the temperature rises.
The display patterns 8a, 8b, 8c, and 8d may be liquid crystals that change color as the temperature rises.

Effects of the Invention As is clear from the above embodiments, the present invention provides an induction heating cooker equipped with a pot mounting plate provided with at least one magnetic material provided with a display pattern made of a substance that changes color as the temperature rises. With this configuration, it is possible to detect with a simple configuration that the pot mounting plate has shifted from the center of the heating coil, and also reduce magnetic flux radiated from the heating coil, reduce radio interference,
Furthermore, it is possible to realize an excellent induction heating cooker that can contribute to improving the safety against the load of small items placed on the upper surface of the heating coil in the deviated portion of the pot mounting plate.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an induction heating cooker according to an embodiment of the present invention, Fig. 2 is a sectional view of an induction heating cooker according to an embodiment of the present invention, and Figs. 3A and B are an embodiment of the invention. FIGS. 4A and 4B are explanatory diagrams of the operation in another embodiment of the present invention, FIG. 4C is a perspective view of the magnetic body in another embodiment of the present invention, and FIG. 5 is the conventional The configuration diagram of the induction heating cooker, FIGS. 6A and 6B, are a bottom view and a side view of the main parts of a conventional induction heating cooker. 1...Table, 2...Top plate, 3...
...Pot placement board, 5...Display pattern, 6...
...Magnetic material, 7b...Heating coil, 8a,
8b, 8c, 8d---Display pattern, 9a...
...Magnetic material. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 7b Figure 5: zta8b description---Display root stock Figure 6/3c/λ/, 3b/3(2/3b

Claims (1)

[Claims] An induction heating unit provided with a heating coil or the like is incorporated into the lower surface of a top plate of a table or the like, a pot placing plate is removably provided on the top plate, and at least one of the above-mentioned pot placing plates is heated by magnetic flux from the heating coil. An induction heating cooker comprising one magnetic body, and a display pattern made of a substance that changes color due to temperature rise on the magnetic body.