JPS628491A - 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, and particularly to a temperature display on its top plate.

[Conventional technology]

FIG. 5 is an external perspective view of a conventional induction heating cooker disclosed in, for example, Japanese Utility Model Publication No. 54-37083. In the figure, 1 is an upper plate made of an insulating plate such as glass or ceramic; A high frequency oscillator sends power to an inductor coil (not shown) placed on the lower surface of the plate 1, and 3 is a support leg. 4
is a radial display pattern marked on the surface (upper surface) of the upper plate 10 at the position where the cooking pot is placed, and part or all of it is drawn with paint (thermo paint) that changes color depending on the temperature.

When this cooker is connected to a power source, a metal cooking pot is placed on the top plate 1, and the switch is turned on, power is supplied to the inductor coil via the high frequency oscillator 2, the well-known electromagnetic induction effect Eddy currents are induced in a metal cooking pot, and the eddy currents generate heat at the bottom of the pot, resulting in cooking.

In this way, the induction heating cooker heats metal steel, which is originally a good electrical conductor, by induction, and the upper plate 1 made of an insulating material is not heated by induction. However, in reality, the heat from the heated pot is transferred to the top plate 1 and becomes almost as hot as the bottom of the pot, so if you touch the top plate immediately after removing the pot, you may get burned. Therefore, we drew a display pattern 4 showing the placement position of the cooking pot using thermo paint, and by changing the color of the paint,
By notifying the user of dangerous temperatures, the risk of burns can be prevented.

[Problem that the invention seeks to solve]

In conventional induction heating cookers, the display pattern indicating the placement position of the cooking pot was drawn on the exposed surface of the top plate using thermo paint7, so with repeated use, the pot and The problem was that the paint peeled off due to friction, making it unsuitable for long-term use.

Furthermore, even if a protective film is formed on the display pattern to prevent the display pattern from peeling off, there is a risk that the protective film itself may peel off, and it is also prone to staining due to seepage of boiled water etc. However, it cannot be said that everything is perfect.

This invention was made to solve the above-mentioned problems, and there is no fear that the display pattern will peel off due to friction with a pot, etc., and the temperature of the top plate can be displayed reliably for a long period of time. The purpose is to obtain a cooker.

[Means to resolve the issue]

The present invention provides an induction heating cooker that heats a cooking pot placed on an upper plate by electromagnetic induction.

This is an induction heating cooker that has a three-layered structure, with the upper layer being a transparent crystallized glass plate, the middle layer being a tape that reversibly changes color depending on temperature, and the lower layer being a heat-resistant glass plate.

[For production]

In the present invention, whether the temperature of the upper plate is higher than a predetermined temperature is indicated by the color of the tape that reversibly changes color depending on the temperature when it is sandwiched between the upper plate and the transparent crystallized glass plate.

A top layer of transparent crystallized glass plate covers the tape to prevent direct contact of the cooking pot with the tape and to prevent spilled boiling water from being sprinkled on the tape.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is an external perspective view of an induction heating cooker equipped with an upper plate according to the present invention, where 10 is the main body of the cooker, 20 is an upper plate on which a cooking pot, etc. is placed, and 20a is the upper plate 20 along with the proper position of the pot device. This is a display pattern that indicates whether or not the temperature is higher than a predetermined temperature.

Details of the structure of the above-mentioned upper plate 20 are shown in FIGS. 2 and 3. That is, the upper plate 20 has a three-layer structure, with 21
is a relatively thin heat-resistant glass plate forming the lower layer, 18
It can be used up to a temperature of about 0°C. 22 is a tape (thermo tape) that reversibly changes color depending on the temperature and has a display pattern 20a attached to the center of the upper surface of the heat-resistant glass plate.
The discoloration temperature is preferably about 80°C, for example.

The display shape of the tape is not limited to the circular shape shown in the drawings, but may be freely determined such as a radial pattern. A transparent crystallized glass plate 23 is placed over the thermo tape 22, and forms an upper layer on which a cooking pot or the like is placed.

The upper plate 20 configured in three layers in this way is assembled into the cooking device main body 10. When a cooking pot is placed above the display pattern 20a of the top plate 20 and induction heating is started, the heat of the induction heated pot is transferred to the top plate 20. As a result, upper board 2
0 reaches a predetermined temperature (for example, 80° C.) or higher, the color of the thermo tape 22 changes to notify the user that the top plate 20 is hot. The discoloration of the tape can be reliably visually recognized because the crystallized glass plate 23 is transparent. Since the thermo tape 22 is covered with a crystallized glass plate 23, it does not wear out or peel off due to contact with a pot or the like, and can be used for a long time.

Moreover, the top layer crystallized glass plate 23 has a smooth surface and is hard.
Due to its high strength and heat resistance, it is difficult to damage and can be easily wiped away, allowing it to be kept clean for a long period of time.

FIG. 4 shows another embodiment.

In this embodiment, the thermo tape 22 attached to the upper surface of the heat-resistant glass plate 21 constituting the upper plate 20 displays characters such as "hot", and the heat-resistant glass plate 21 is displayed in the color of the thermo tape 22 before high temperature discoloration. The difference from the first embodiment is that the first embodiment is colored in the same color (for example, by painting or printing).

According to this embodiment, when the temperature of the upper plate 20 is above a predetermined value,
Characters such as ``hot'' stand out from the background color, making it possible to urge the user to be more careful.

In each of the above embodiments, the thermo tape 22 is attached to the upper surface of the lower layer heat-resistant glass plate 21, but it may be attached to the lower surface of the upper layer crystallized glass plate 23.

〔Effect of the invention〕

As described above, according to the present invention, the upper plate of the induction heating cooker is made of an upper layer made of a transparent crystallized glass plate, a lower layer made of a heat-resistant glass plate, and is reversible depending on the temperature sandwiched between the two glass plates. 3 with an intermediate layer consisting of a tape that changes color
Because of the layered structure, the display pattern does not peel off or wear out, and it is possible to provide an induction heating cooker that can reliably display the temperature on the top plate over a long period of time.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of one embodiment of the present invention, FIG. 2 is an exploded perspective view of the upper plate shown in FIG. 1, FIG. 3 is an assembled side view of the top plate shown in FIG. 21, and FIG. FIG. 5 is a perspective view of a component showing another embodiment of the present invention, and FIG. 5 is an external perspective view showing an example of a conventional induction heating cooker. 201d upper plate, 21 is a heat-resistant glass plate, 22 is a thermochromic tape, and 23 is a crystallized glass plate.

Claims (2)

[Claims] (1) In an induction heating cooker that heats a cooking pot or the like placed on an upper plate by electromagnetic induction, the upper plate includes a transparent crystallized glass plate forming an upper layer and a heat-resistant glass plate forming a lower layer. and a tape that reversibly changes color depending on the temperature and forms an intermediate layer between the two glass plates. (2) Predetermined characters are displayed using the tape that reversibly changes color depending on the temperature, and the heat-resistant glass plate is colored in the same color as the color of the tape before the high-temperature discoloration. Induction heating cooker described in section.