JPS59123187A - Electromagnetic induction heating cooking device - 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] [Technical Envelope of the Invention] This invention is based on the fact that when a high-frequency magnetic field is applied to a cooking pot, an eddy electric current is generated in the dM cooking pot. Electromagnetic induction heating that performs tiles by self-heating 4
Regarding the circumferential device.

[Technical background of the invention]

Conventionally, there is a cooking device of this type as shown in FIG. In FIG. 1, reference numeral 1 denotes an alternating loop power source, and the output of this power source #1 is rectified by a rectifier circuit 2 and supplied to an inverter circuit 3. The inverter circuit 3 converts the direct voltage supplied from the rectifier circuit 2 into a predetermined AC voltage by switching the switching elements, and supplies it to the heating operation section 4. The heating operation unit 4 constitutes a resonant circuit with a heating coil 40 and a capacitor (not shown), and applies the exchange voltage supplied from the inverter circuit 3 to the resonant circuit, and is transmitted to the heating coil 40. A high frequency magnetic field is generated from the heating coil 40 using a frequency current. Heating coil 40 is 4+q vortex (magnetic material) 5
It will be erected near the set part. - power, 1 The output of the source 1 is supplied to the main control circuit 6. This main control circuit 6 controls the on/off duty of the switching elements in the inverter circuit 3 according to the heating output (2) that is set.

Note that the main control section 6 is supplied with a signal from the heating operation section 4 indicating whether or not a cooking pot is set.

[Problems with background technology]

By the way, in such an electromagnetic induction heating cooker,
When the material and size of the cooking pot 5 change, the inductance of the heating coil 40 changes accordingly, but the on/off duty of the switching element in the inverter circuit 3 is fixed in accordance with the set heating output. As shown in FIG. 2, there is an interval in which the high frequency current flowing through the heating coil 40 changes greatly depending on the change in the inductance of the heating coil 4C. There was room for improvement in terms of reliability, as the heating output was dependent on the material and size of the cooking pot 5, and the time taken to complete cooking was unstable.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide an electromagnetic induction heating cooker that can always maintain the heating needle in a constant state (2) regardless of the material or size of the cooking pot, thereby enabling stable cooking. There is a particular thing.

[Summary of the invention]

This invention provides means for detecting the inductance of the heating coil, and controls the heating output according to the detection result.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. However, in the drawings, the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 3, reference numeral 11 denotes a heating coil current detection circuit, which detects the high frequency current flowing through the heating coil 4C. The detection result of this heating coil 'lucidity detection circuit 11 is A/
It is converted into a digital signal by a D (analog/digital) converter 12 and supplied to a microcomputer 13.

The microcomputer J3 determines the inductance of the heating coil 40 according to the detection result of the heating coil current detection circuit 11, and uses the determined inductance to determine Ig! , it is also determined whether the pot 5 is appropriate or not, and the results of these determinations are supplied to the main control section 6 via an A/A (digital/analog) converter 14. In addition,
A speech synthesizer 15 is connected to the main control section 6, and the speech information emitted from the speech synthesizer 15 is outputted as actual speech (converted into two voices) through a speaker 16.

Next, the operation in the above configuration will be explained.

First, before starting cooking, when the :A cooking pot 5 is set, it is detected by the heating operation section 4, and the high-rise electric hoop is given up to the heating coil 40 by the action of the main side @1 section 6. This high frequency current is detected by the heating coil w current detection circuit, and the microcomputer 13 determines whether the inductance of the heating coil 4C and the cooking pot 5 are appropriate. However, if it is determined that the cooking pot 5 is not appropriate because it is too large or too small, the voice synthesizer 15
The voice information indicating that the voice is not appropriate is emitted from the speaker 16, and the voice information is emitted from the speaker 16 as an actual voice. therefore,
The user can easily sense whether the cooking pot 5 is suitable or not.

When heating is started, an inverter drive signal with on/off duty corresponding to the determined inductance and set heating output is supplied from the main control section 6 to the inverter circuit j path 3. That is, as shown in FIG.
The inverter turns on according to the inductance change of the signal.

As the off-duty changes, the level of the voltage applied to the common circuit in the heating operation section 4 changes as shown in the figure. There is no control to ensure that the value remains constant.

In this way, by taking into consideration the change in inductance of the heating coil 40 in the control of the heating output, the heating needle can always be held constant regardless of the quality or size of the cooker 5, and the same cooking can be achieved. The time it takes for Yuuri to complete that is always constant.

It should be noted that this invention is of course not limited to the above-mentioned embodiments, and can be modified in various ways without changing the gist.

〔Effect of the invention〕

As described above, according to the present invention, regardless of the material used or the size of the control pot, the heating temperature can be maintained at a certain level at all times, making it possible to achieve more stable cooking than C2. It is possible to provide an electric [3'i induction PA processor with excellent reliability.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of a control circuit of a conventional electromagnetic induction heating cooker, FIG. 2 is a diagram showing changes in heating coil current in FIG. FIG. 4 is a schematic configuration diagram of the control circuit shown in FIG. 4, and is a diagram for explaining the operation of the same embodiment. , 9... Inverter circuit, 4... Heating operation section, 4C
... Heating coil, 6... Main control circuit, 1)... Heating coil current detection circuit, 13... Microcomputer, 15... Speech synthesis device. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Showa 5-June PA-Japan Commissioner of the Patent Office Kazuo Wakasugi 1. Indication of the case Patent application No. 1983-233544 2. Title of the invention Electromagnetic induction heating cooker 3, relationship with the case of the person making the amendment Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4, agent address 17 Mori Building 6, 1-26-5 Toranomon, Minato-ku, Tokyo, of the amendment Full text of the surrounding specification 7 Reprint of the amended specification (no change in content)

Claims (3)

[Claims] (1) In an N-magnetic induction heating appliance that applies a high-frequency magnetic field to a cooking pot from a heating coil and cooks by the self-heating of the cooking pot, a detection means for detecting the inductance of a silent coil, and this detection. A magnetic induction IJD thermal cooker comprising: control means for controlling the strength of the high frequency magnetic field emitted from the heating coil according to the detection result of the means. (2) The electromagnetic induction cooking device according to claim 1, wherein the detection means detects the inductance before starting cooking. (3) The control means determines whether or not the cooking pot is appropriate based on the detection result of the detection means, and notifies this determination result with a voice generated by a voice synthesizer. Or the electromagnetic induction heating cooker according to item 2.