JPH03184295A - Induction heating cooker - Google Patents

Abstract

PURPOSE:To directly detect a cooking vessel temperature by receiving infrared ray, radiated from a cooking vessel placed on a cooling vessel placing surface, with an infrared ray sensor. CONSTITUTION:The upper surface of a min body 1, in which an induction heating coil 4 and an infrared ray sensor 5 are provided in the inside, is covered with a cooking vessel placing surface 3 composed of e.g. infrared ray transmission material part or the whole of which transmits the infrared ray of crystallization silicone, etc. The infrared ray sensor 5 detects infrared ray, generated from the surface of a pan 2 placed on the cooking vessel placing surface 3, through the cooking vessel placing surface 3. Because thus the infrared ray sensor 5 catches the infrared ray corresponding to temperature radiated from a cooking vessel 2, the temperature of the cooking vessel 2 can be directly detected, the time lag of temperature detection or the absolute error of detected temperature reduces, and correct temperature can be grasped.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an induction heating cooker that heats a cooking pot or the like using eddy currents caused by magnetic flux.

BACKGROUND OF THE INVENTION In recent years, induction heating cookers have become popular in the market. below,
An example of the conventional induction heating cooker mentioned above will be explained with reference to FIG. 21 is an induction heating cooker that heats the cooking container 22 by induction. 23 is an induction heating cooker 21
This is the cooking container mounting surface that covers the surface of the cooking container. 24 is an induction heating coil; 25 is a heat sensitive element that detects the temperature of the cooking container mounting surface 23 and outputs a signal according to this temperature; 26 is a temperature detection circuit that detects the temperature state from the output of the heat sensitive element 25; 27 is a heating side #circuit that performs heating control based on information obtained from the temperature detection circuit 26. Reference numeral 28 is a reference setting section through which the user sets desired temperature and the like.

The temperature detection and heating control operations of the conventional induction heating cooker configured as described above will be described below. cooking container 2
2 is heated by the heating coil 24 and its temperature rises. This temperature is detected by the heat sensitive element 25 via the cooking container mounting surface 23. The thermal element 25 outputs a signal corresponding to this temperature to the temperature detection circuit 26, and the temperature detection circuit 26 outputs the information to the heating $IJ 11 circuit 27. The heating control circuit 27 uses information from the reference setting section and the temperature detection circuit 2.
The output of the heating coil 24 is controlled based on the information from 6.

In this way, the temperature of the cooking container 22 placed on the cooking container mounting surface 23 is controlled.

Problems to be Solved by the Invention However, in the above configuration, the temperature of the cooking container 22 is detected via the cooking container mounting surface 23, which is indirect measurement, and the detected temperature is delayed in time. However, there were problems such as the inability to accurately detect temperature. In particular, if the bottom surface of the cooking container 22 is warped or otherwise deformed and is floating above the cooking container mounting surface 23, an air layer will exist between the cooking container 22 and the layer time deviation and temperature error will increase. It was something.

The present invention aims to solve the problems that such conventional configurations have, and firstly, it is to provide an induction heating cooker with a configuration that can directly detect the temperature of a cooking container. This is the purpose. The second objective is to provide an induction heating cooker that can accurately control temperature by incorporating directly detected temperature information into a heating control system. A third object of the present invention is to provide an induction heating cooker that can stop heating a cooking container if the cooking container is placed in an inappropriate position.

Means to Solve the Problem The first means to achieve the first objective is to use an induction heating coil and an infrared sensor installed inside the main body, and a material that transmits infrared rays in part or in whole. The induction heating cooker has a cooking container placement surface, and the infrared sensor detects the temperature of the cooking container by receiving infrared rays emitted from the cooking container placed on the cooking container placement surface. It is something. A second means for achieving the second objective is an induction heating cooker that takes in the output of the infrared sensor into a feedback loop of a heating control system to perform heating control. The third means to achieve the third objective is
Only a part of the cooking container mounting surface is made of infrared transmitting material, and an infrared sensor is installed opposite to this infrared transmitting material, and the heating state is determined based on the elapsed time input to the induction heating coil and temperature information from the infrared sensor. This is an induction heating cooker that has a judgment circuit for making judgments.

Function The first means described above is one in which an infrared sensor captures infrared rays corresponding to the temperature emitted from the cooking container and allows the temperature of the cooking container to be directly observed. This reduces the absolute error in detected temperature and allows accurate temperature determination. Moreover, the second means is capable of realizing highly accurate temperature control by incorporating the temperature detected by the above-mentioned infrared sensor into the heating control system. The third means is the cooking container III
! A part of the placing surface is made of infrared transmitting material and has a judgment circuit that judges the heating state based on the elapsed time input to the induction heating coil and temperature information from the infrared sensor, so if the cooking container is placed in an inappropriate position. can stop heating the cooking container.

EXAMPLE Hereinafter, an example of the first means of the present invention will be described with reference to FIG. 2 is an induction heating cooking machine main body (hereinafter simply referred to as the main body) having an induction heating coil 4 and an infrared sensor 5 inside.

The upper surface of the main body 1 is covered with a cooking container mounting surface 3 that is partially or entirely made of an infrared transmitting material such as crystallized silicon that transmits infrared rays.

2 is a cooking device placed on the cooking container placement surface 3 by the user! (hereinafter referred to as steel). The infrared sensor 5 detects infrared rays generated from the surface of jA2 through the cooking container mounting surface 3.

Next, the operation of this embodiment will be explained. When the user turns on a switch (not shown), power is supplied to the induction heating coil 4 and a high frequency magnetic field is generated. This high-frequency magnetic field causes the pot 2 to
An eddy current is generated, and the pot 2 is heated. At this time, infrared rays are emitted from the bottom of the pot 2 according to the temperature. This infrared ray passes through the cooking container mounting surface 3 made of an infrared transmitting material and reaches the infrared sensor 5. Infrared sensor 5
captures this and outputs a signal corresponding to the temperature to a control circuit (not shown).

In this way, in this embodiment, since the temperature of the pot 2 is directly detected using the infrared sensor 5, there is no time delay and the temperature can be detected accurately.

Next, an embodiment of the second means will be described based on FIG. 2. Components that are the same as those in FIG. 1 are given the same reference numerals, detailed explanations are omitted, and differences will be mainly explained. 6 is a temperature detection circuit that receives the output of the infrared sensor 5 and detects the temperature, and 7 is a heating control circuit that judges the output of the temperature detection circuit 6 and issues a command to heat or stop heating. This heating control circuit 7 is connected to an infrared sensor 5 that detects infrared rays generated from the pot 2, and forms a closed feedback loop. Reference numeral 8 denotes a reference setting unit that serves as a reference for determining whether to heat or stop heating, and this setting is performed by the user.

The operation of the heating control configured as described above will be explained. The temperature detection circuit 6 detects the temperature from the output signal of the infrared sensor 5 and outputs this signal to the heating control circuit 7, as in the embodiment of the first means described above. Upon receiving this signal, the heating control circuit 7 compares the temperature with the temperature of the reference setting section 8 set by the user, and if the temperature is lower than the reference temperature, the induction heating coil 4 is turned off.
The heating of the pot 2 is continued by supplying power to the pot 2. Moreover, if the temperature of the pot 2 rises and becomes higher than the reference temperature, the power supplied to the induction heating coil 4 is stopped.

As described above, according to this embodiment, a series of heating controls is configured by a feedback loop, and by providing the cooking container mounting surface 3 and the infrared sensor 5 made of an infrared transmitting material in the loop, the time delay can be reduced. In addition, the induction heating cooker can perform heating control with small temperature errors.

FIG. 3 is a block diagram of an induction heating cooker which is an embodiment of the third means. Reference numeral 9 denotes an infrared transmitting material formed only on a part of the cooking container mounting surface 10.

An infrared sensor 5 is provided facing the infrared transmitting material 9. The pot 2 is shown placed in a position with the infrared transmitting material 9 removed by the user. In other words, it is placed in an inappropriate state. Reference numeral 11 indicates a small item such as a spoon that is not to be heated. 12 is a time measurement circuit that counts the elapsed time after the power switch (not shown) of the main body 1 is turned on; 13 is information on the elapsed time obtained from the time measurement circuit 12 and temperature information obtained from the temperature detection circuit 6; This is a judgment circuit that determines whether or not heating is inappropriate based on The alarm means 14 which issues an alarm to the user is activated.

The operation of this embodiment will be explained below. When the pot 2 is heated in the state shown in FIG.
The viewing angle of the infrared sensor 5 provided opposite to this is limited. Therefore, even if the temperature of the misaligned pot 2 rises, the infrared sensor 5 will not detect infrared rays. On the other hand, the judgment circuit 13
The passage of a certain period of time is recognized based on the elapsed time information from when the power switch of the main body 1 is turned on, which is output by the device 2, and the temperature information detected by the temperature detection circuit 6 at the moment when this certain period of time has elapsed is checked. In this way, if the ratio of elapsed time and temperature information is checked and the temperature rise is small, it is determined that the mounting position is inappropriate and a signal is sent to the alarm means 14 to call the user's attention. At the same time, the heating control circuit 7 is driven to stop the power supply to the induction heating coil 4.

As described above, in this embodiment, if the position of the pot 2 placed by the user is inappropriate, the user can be warned of this and the heating can be stopped at the same time. The same applies when the small object 11 is heated, but a separately provided small object detection circuit can prevent heating if only the small object is present.

Effects of the Invention As described above, the first means of the present invention provides an induction heating cooker that can directly detect the temperature of a cooking container, and therefore can accurately detect temperature without time delay. can do. Moreover, according to the second means, in addition to the effects of the first means, it is possible to provide an induction heating cooker capable of high-speed and highly accurate temperature control. Furthermore, according to a third means, there is provided an induction heating cooker that can warn a user or stop heating when a pot is placed on a cooking container placement surface in an inappropriate state. I can do it.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the first means, Fig. 2 is a block diagram showing an embodiment of the second means, and Fig. 3 shows an embodiment of the third means and the fourth means. Block diagram, 4th
The figure is a block diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Main body, 2... Cooking container, 3. 10... Cooking container mounting surface, 4... Induction heating coil, 5... Infrared sensor, 6... Temperature detection circuit, 7. ...Heating control circuit, 8... Standard setting section, 9... Infrared transmitting material, 11
...Non-heated object, 12...Time measurement circuit, 13.
... Judgment circuit, 14... Alarm means.

Claims (3)

[Claims] (1) It has an induction heating coil and an infrared sensor provided inside the main body, and a cooking container mounting surface partially or entirely made of a material that transmits infrared rays; An induction heating cooker that detects the temperature of a cooking container by receiving infrared rays emitted from the cooking container. (2) The induction heating cooker according to claim 1, wherein the output of the infrared sensor is taken into a feedback loop of a heating control system to perform heating control. (3) Only a part of the cooking container mounting surface is made of an infrared transmitting material, and an infrared sensor is provided facing the infrared transmitting material, and heating is performed using the elapsed time input to the induction heating coil and temperature information from the infrared sensor. The induction heating cooker according to claim 1 or 2, further comprising a judgment circuit for judging the state.