JPH02119083A - Induction heating cooker - Google Patents

Abstract

PURPOSE:To improve safety, more specially to prevent an empty pan from being heated due to inadvertent failure to magnetically attach a temperature sensor to the pan by judging the attachment of the sensor based on the on-off condition of a switch in the sensor and, in the case the result is off, controlling with a top plate temperature sensor of a cooker. CONSTITUTION:When a temperature sensor 11 is magnetically attached to a cooking pan 4 by means of a permanent magnet 14 and an iron plate 15, a metallic piece 16 is pressed into a case 13 to turn a switch 18 on. When the magnetic attachment is imperfect, however, the metallic piece 16 is pushed back with a coil spring 17 to turn the switch 18 off. A control circuit 10 judges the on-off condition of the switch 18 based on the change in the value of voltage. When the switch is judged to be on, a changeover switch is turned to the sensor 11 side to control the temperature of the cooking pan 4 with a heating output control 12. When the switch is judged to be off, connection is made to a top plate temperature sensor 12 side to indirectly control the cooking pan 4 temperature. As a result, the pan 4 is prevented from being heated empty even if the temperature sensor 11 is not attached to the pan 4 due to inadvertent failure, improving safety.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an induction heating cooker, and particularly to a sensor for detecting the temperature of the cooking pot thereof.

[Conventional technology]

FIG. 8 shows a sectional view of a main part of an example of a conventional 6-induction heating cooker disclosed in, for example, Japanese Utility Model Application Publication No. 55-35449.

(Configuration) In the figure, 1 is the main body of the induction heating cooker, 2 is the heating coil, 3 is the power supply circuit, 4 is the cooking pot, 5 is the food to be cooked in the pot,
6 is a top plate on which the cooking pot 4 is placed; 7 is a cover for the 5-sensor IA element 8; 9 is a conductor; and 10 is a control circuit. FIG. 9 is a cross-sectional view of the main part of the mounting part of the temperature sensor.
is a temperature sensor made of a permanent magnet.

(motion) Next, the operation of the above configuration will be explained.

A high frequency current is applied to the heating coil 2 by the power supply circuit 3, and the cooking pot 4 is heated by induction. In order to bring the food 5 to a temperature suitable for cooking, the temperature is controlled by detecting the temperature of the food 5 with the temperature sensing element 8 and controlling the heating output with the control circuit 10.

In addition, in FIG. 9, a temperature sensor 11 equipped with a temperature sensing element 8 is magnetically attached to a predetermined location of the cooking pot 4, and by detecting the temperature of the cooking pot 4, the temperature of the food 5 can be indirectly detected. Upon detection, the heating output is controlled by the control circuit 10', thereby controlling the cooking temperature. This method is superior in terms of hygiene and cooking workability because it is not necessary to directly insert the temperature sensing element 8 into the food 5 itself.

[Problem to be solved by the invention]

However, since the conventional induction heating cooker is configured as shown below, if the temperature sensor 8 is forgotten to be attached to the cooking pot 4, the temperature of the cooking pot 4 cannot be detected. In addition, there were problems regarding cooking/safety, such as the inability to prevent dry cooking of the cooking pot 4.

This invention was made in order to solve the problems of the prior art as described above, and it is possible to detect a situation such as forgetting to turn on the temperature sensor, and also to detect a temperature at which the temperature of the cooking pot can be detected with good results. The purpose is to provide sensors.

(Means for solving the problem) Therefore, in the induction heating cooker according to the present invention,
They each include a temperature sensing element, a permanent magnet, an iron plate that is magnetized by the permanent magnet, a spring means for bringing the temperature sensing element into contact with the cooking pot, and a switch means that turns on when the temperature sensing element is magnetically attached to the cooking pot. a temperature sensor provided thereon, an upper plate temperature sensor disposed on the lower surface of the upper plate on which the cooking pot is placed, and heating output by selecting both temperature sensors by turning on/off the switching means. The above object is achieved by configuring the device to include a control circuit for controlling the device.

(Function) With the above-described configuration, in the temperature sensor of the present invention, the iron plate magnetized by the permanent magnet magnetically attaches to the cooking pot, and the temperature sensing element comes into contact with the cooking pot 17 and turns on the switch. . The temperature sensor is connected to the control circuit, and it can be determined whether the temperature sensor is correctly attached to the cooking pot by turning on/off the switch, so if you forget to attach the temperature sensor, etc. Gains 1 point of protection against dry firing, etc.

〔Example〕

The present invention will be explained below based on examples.

(Structure) FIG. 1 is a cross-sectional configuration diagram of main parts of an embodiment of an induction heating cooker according to the present invention, and FIGS. 2(a) and (b) are horizontal/vertical cross-sectional views of the temperature sensor 11, respectively. FIG. 3 shows a perspective view thereof, and the same (equivalent) components 1 to 11 as in FIGS. 8 and 9 of the conventional example are denoted by the same reference numerals, and redundant explanation will be omitted.

In FIG. 1, 12 is a -L top plate temperature sensor, which is most often used in ordinary induction cookers, and indirectly detects the temperature of cooking 5 through the bottom of the cooking pot 4 and the top plate 6. . 13 is a case for storing the temperature sensor 11; 14;
1 is a permanent magnet, and 15 is an iron plate that is magnetized by the permanent magnet 14 and magnetically attached to the cooking w44. 16
is a metal piece made of aluminum or the like having a relatively high heat transfer coefficient, and houses the moisture-sensitive element R9 therein, is inserted so as to be able to slide in the axial direction inside the case 13, and is brought into contact with the cooking pot 4 so as to be heat-responsive. It is intended to improve the

A compression coil spring 17 is used to push the metal piece 16 into contact with the cooking pot 4.

Reference numeral 18 denotes a switch, which is configured to be closed (turned on) by the metal piece 16 when the temperature sensor 11 is magnetically attached to the cooking pot 4.

FIG. 4 is a switching circuit configuration diagram showing which of the temperature sensor 11 and the upper plate temperature sensor 12 is used as an input to the control circuit 10. When the switch 18 is on, the temperature sensor 11
The changeover switch 19 is configured to change over so that the upper plate temperature sensor 12 is operated manually by the control circuit 10 when it is off.

(Operation) Next, the operation in the configuration as described below will be explained. Temperature sensor 11 is magnetically attached to cooking pot 4 by permanent magnet 4 and iron plate 15 . The metal piece 16 is pushed into the case 13 while contacting the cooking pot 4, and the switch 18 is turned on. If the temperature sensor 11 is not attached to the ladle 4, the compression coil spring 17 pushes back the metal piece 16 and turns off the switch 18. The resistance inside the control circuit 10 and the temperature sensing element 8 of the temperature sensor 11 are connected to the switch 18.
The open/closed state of the switch 8 is determined by the change in voltage value, and if the switch 8 is on, the selector switch 19 is connected to the temperature sensor 11 side, and the temperature of the cooking pot 4 is controlled by heating output control. Control. On the other hand, if the switch 18 is off, the selector switch 19 is connected to the upper plate temperature sensor 12 side and operates to indirectly control the temperature of the cooking pot 4.

(Other Embodiments) In the above embodiment, the temperature sensing element 8 is replaced by the metal piece 16.
5(a) and (b) if the temperature sensing element 8 is not likely to be damaged by external force.
) and FIG. 6 is a view corresponding to FIGS. 2(a), 3(b) and 3, the metal piece 16 may be replaced by a heat-resistant rubber 20 having elasticity. By doing so, when the temperature sensing element 8 comes into contact with the cooking pot 4, the heat resistant rubber 20 covers the temperature sensing element 8, making it possible to detect temperature unaffected by outside air.

In addition, as shown in FIG. 7, which is a diagram equivalent to FIG. It may be possible to block it from outside air so that it will not be affected by it. In this case, the temperature sensing element 8 can be protected from boiling over of the food 5 to the outside of the cooking pot 4.

〔Effect of the invention〕

As explained above, according to the present invention, it is determined whether or not the temperature sensor of the induction heating cooker is magnetically attached to the cooking pot by turning on/off the switch inside the temperature sensor, and whether or not the temperature sensor of the induction heating cooker is magnetically attached to the cooking pot is determined. In this case, since the temperature is controlled by the upper plate temperature sensor inside the cooker, it is possible to prevent the cooking pot from dry-frying due to forgetting to attach the temperature sensor, etc., and improve safety.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram of essential parts of an embodiment of an induction heating cooker according to the present invention, FIGS. 2(a) and (b) are horizontal and vertical cross-sectional views, respectively, of the temperature sensor thereof, and FIG. Its perspective view,
FIG. 4 is a switching circuit configuration diagram of the temperature sensor and the -L plate temperature sensor according to this embodiment, FIGS. 5(a), (b), and 6.
The figure shows the second surface diagram of a temperature sensor showing other embodiments.
Figures (a), (b) and figures corresponding to Figure 3, Figure 7 are perspective views of other embodiments of the temperature sensor, and Figure 8 is a cross-sectional configuration diagram of essential parts of an example of a conventional induction heating cooker. , FIG. 9 is a sectional view of the main part of the temperature sensor mounting part. Note that in each figure, the same reference numerals indicate the same or constituent elements. In the figure, 1 is the cooking device body, 4 is the cooking pot, 6 is the upper plate,
8 is a temperature sensing element, 10 is a control circuit, 11 is a temperature sensor, 1
2 is an upper plate temperature sensor, and 19 is a changeover switch. Figure 1 Meat 2 Figure So

Claims (1)

[Claims] A temperature sensing element, a permanent magnet, an iron plate magnetized by the permanent magnet,
A temperature sensor including a spring means for bringing the temperature sensing element into contact with the cooking pot, a switch means that closes the circuit when magnetically attached to the cooking pot, and a lower surface of an upper plate on which the cooking pot is placed. 1. An induction heating cooker comprising: a top plate temperature sensor provided in the top plate; and a control circuit for selecting both temperature sensors and controlling heating output by closing/opening the switch means.