JP2005141962A - Induction cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction cooker which can detect the temperature of a cookware placed on a top plate with superior accuracy. <P>SOLUTION: In a sensor holder 12 arranged underneath the top plate 1 which places a cookware 9, a heat-receiving board 14 is provided that has a mounting leg 17 bent downward, inserted into a mounting hole 17 installed at the upper part of the sensor holder 12, a temperature sensor 14 covered with electrical insulating material 13 is installed in the recessed groove 16 installed adjacent to the mounting hole 17, and the heat-receiving board 14 covers the upper part of the temperature sensor 14 covered with the electrical insulating material 13, thereby the temperature of the cookware 9 can be measured with superior precision. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an induction heating cooker that can accurately measure temperature.

  The conventional induction heating cooker performs wide-area temperature detection on the lower surface of the top plate by using a method such as collecting heat from a wide range using a heat collecting plate or a method using multiple temperature sensors. It was.

  This is to solve the problem that in the temperature detection in which the sensor is directly attached to the top plate, the detection temperature varies depending on the shape of the bottom of the cooker.

  As an example of a conventional induction heating cooker, two types of temperature sensors, a temperature sensor having no heat receiving plate and a temperature sensor having a heat receiving plate, are fixed below the top plate, and signals based on these two temperature sensors To control the input to the induction heating coil (see, for example, Patent Document 1).

FIG. 8 shows the configuration, in which the heating coil 4 for heating the cooking utensil is arranged in the main body 2, and the first temperature sensor 14 not having the heat receiving plate 15 made of a nonmagnetic metal is disposed at the center of the heating coil 4. The second temperature sensor 14 having the heat receiving plate 15 is provided in the diameter direction of the heating coil 4 at the outer periphery and the outer periphery. The heat receiving plate 15 is set in an elongated strip shape.
JP-A-4-2090

  However, in the above conventional configuration, since the area where the temperature sensor can contact the top plate or the heat receiving plate is small, the heat conduction is not good, and even if a plurality of temperature sensors are used, the structure is complicated and the accuracy is high. There was a problem that good temperature detection was not possible.

  The present invention solves such a conventional problem, and provides an induction heating cooker that can accurately transfer the heat of a cooking utensil to a temperature sensor via a top plate and accurately measure the temperature of a cooking container. It is an object.

In order to achieve the above object, the present invention
A top plate for placing the cooking utensil, a heating coil provided below the top plate, a frequency conversion circuit for supplying a high frequency current to the heating coil, and the temperature of the cooking utensil corresponding to the heating coil are adjusted to the top plate And a temperature detector for detecting the temperature of the temperature sensor, the temperature detector holding the temperature sensor with the sensor holder and thermally connecting the heat receiving plate for transferring heat from the top plate to the sensor holder in multiple paths. In addition to transferring heat from the heat receiving plate to the temperature sensor via the sensor holder, heat from the top plate is transmitted to the sensor holder and further to the temperature sensor. Such a so-called two-system heat transfer significantly increases the temperature detection characteristics.

  According to the induction heating cooker of the present invention, the temperature detection characteristic is remarkably enhanced by the heat transfer of the two systems, and the temperature detection characteristic by the temperature detector can be improved.

  An embodiment of the present invention corresponds to a top plate for placing a cooking utensil, a heating coil provided below the top plate, a frequency conversion circuit for supplying a high-frequency current to the heating coil, and the heating coil. A temperature detector for detecting the temperature of the cooking utensil via the top plate, the temperature detector holding a temperature sensor with the sensor holder and a heat receiving plate for transferring heat from the top plate to the sensor holder. It is configured to be thermally linked and attached in multiple paths.

  Therefore, the heat of the top plate is not only transmitted from the heat receiving plate to the temperature sensor via the sensor holder, but also the heat from the top plate is transmitted to the sensor holder and further to the temperature sensor. The temperature detection characteristics are enhanced by so-called two systems of heat transfer.

  The heat receiving plate is attached by bending a part of the heat receiving plate downward to form an attachment leg, and inserting the attachment leg into an attachment hole provided in the sensor holder. It is desirable to form a plurality of the legs. And the groove | channel and attachment hole which install a temperature sensor were provided in parallel adjacent to the sensor holder, and it was made to improve the heat transfer to a temperature sensor.

  The heat receiving plate has a shape extending from the center to the outer periphery of the heating coil, and if the heating coil has a double spiral coil shape in which an outer coil is wound around the inner coil, a sensor holder is disposed between the inner and outer coils. At the same time, by making the heat receiving plate a shape extending from the center of the inner coil to the outermost periphery of the outer coil, it is possible to detect a wide range of heat.

  In the case of the double spiral coil shape, it is conceivable to arrange a heat receiving plate formed in an arc shape between the inner and outer coils.

  Moreover, you may provide a heat insulation part in the outer periphery of a sensor holder in order to make the heat transfer to a temperature sensor favorable.

  In order to prevent the temperature sensor from being damaged by external pressure, it is also effective to set the upper surface of the electrical insulator covering the temperature sensor below the upper surface of the sensor holder.

  If a heat conducting material is disposed between the heat receiving plate and the electrical insulator, heat transfer to the temperature sensor can be further improved.

  The heat receiving plate is preferably formed of a non-magnetic metal for the purpose of preventing self-heating of the metal due to magnetism.

  Embodiments will be described below with reference to the accompanying drawings.

(Example 1)
In FIG. 1 to FIG. 3, each element for induction heating is provided in a main body 2 which is closed with a top plate 1 made of crystallized glass having a thickness of about 4 mm. More specifically, a heating coil 4 held by a coil holder 3 is disposed below the top plate 1. The heating coil 4 is set in a double spiral coil shape divided into an inner coil 5 and an outer coil 6.

  A high-frequency current is input to the heating coil 4 via a frequency conversion circuit 7 such as an inverter circuit, and the current is controlled by a control circuit 8 that controls cooking temperature and the like.

  A temperature detector 10 that detects the temperature of a cooking utensil 9 such as a pan placed on the top plate 1 via the top plate 1 is held by the coil holder 3 and is interposed between the inner coil 5 and the outer coil 6. Has been placed.

  The temperature detector 10 is housed in the recess 11 of the coil holder 3 so as to be movable up and down, and the sensor holder 12 made of a highly heat-resistant resin and the like and the temperature-resistance element such as a thermistor are covered with heat-resistant glass. The temperature sensor 14 is wrapped with an electrical insulator 13 such as a fluorine resin, and the heat receiving plate 15 is formed of a nonmagnetic material, for example, aluminum which is a heat conducting material having a thickness of 1.0 mm.

  More specifically, the temperature sensor 14 is arranged in a concave groove 16 provided in the upper part of the sensor holder 12, and the concave groove 16 has an elongated shape extending in the tangential direction of the circumference of the inner coil 5. . The heat receiving plate 15 has a rectangular shape so as to straddle both the inner coil 5 and the outer coil 6 in the radial direction, and a pair of mounting legs 17 bent integrally from both sides are formed on the upper part of the sensor holder 12. Are inserted into the mounting holes 18.

  The temperature detector 10 is urged upward by a spring 19 interposed between the sensor holder 12 and the recess 11, and as a result, the heat receiving plate 14 comes into close contact with the lower surface of the top plate 1.

  Note that a heat conductive material 20 such as silicon compound is applied to the upper surface of the heat receiving plate 15 and a part of the lower surface corresponding to the temperature sensor 14 to transfer heat between the top plate 1 and the heat receiving plate 15, the top plate 1. Heat transfer between the temperature sensor 14 and the temperature sensor 14.

  The operation | movement is demonstrated about the electromagnetic induction heating cooking appliance comprised as mentioned above.

  The temperature of the cooking utensil 9 heated by the heating coil 4 rises. The temperature of the cooking utensil 9 is transmitted to the top plate 1, and then transmitted to the heat receiving plate 15, from the heat receiving plate 15 to the temperature sensor 14 via the electrical insulator 13, and from the mounting legs 17 of the heat receiving plate 15. There are two paths: a heat conduction path that is transmitted to the sensor holder 12 and that is transmitted from the sensor holder 12 to the temperature sensor 14 via the electrical insulator 13.

  By using two heat conduction paths, the temperature sensor 14 detects the temperature more quickly, and information is transmitted to the control circuit 8 so that the current supplied from the frequency conversion circuit 7 to the heating coil 4 is controlled. Thereby, the quantity of the magnetic field generated by the heating coil 4 can be changed, and induction heating to the cooking utensil 9 can be controlled.

  Therefore, a highly safe induction heating cooker can be provided by accurate temperature detection. For example, even when the cooking utensil 9 is empty and baked, the cooking utensil 9 can be quickly detected and heated. Can be restricted or stopped.

  Moreover, by making the heat receiving plate 15 into a strip-like rectangle, the temperature of the bottom of the cooking utensil 9 can be received in a wide range, and even if the cooking utensil 9 is displaced, there is a possibility that the bottom and the heat receiving plate 15 face each other. It is high and can receive heat with high sensitivity.

  Further, by bending a part of the heat receiving plate 15 downward, the heat received in a wide range can be attached and efficiently conducted to the legs 10. In addition, by providing a plurality of mounting legs 17 (two in this embodiment), heat can be obtained from a wider range, heat conduction can be improved, and the sensitivity of the temperature sensor 14 can be improved.

  By making the heating coil 4 into a double spiral coil shape in which the outer coil 6 is placed around the inner coil 5, temperature detection is performed between the inner coil 5 and the outer coil 6 having the strongest magnetic field when performing induction heating. The vessel 10 can be installed. Since the highest heat is generated in the place where the magnetic field is strongest, the highest temperature at the bottom of the cooking utensil 9 can be measured with higher sensitivity by placing the temperature detector 10 between the inner and outer coils, and a safer induction. A cooker can be provided.

  In the first embodiment, the spring 19 receives the temperature of the top plate 1 with higher sensitivity by pressing the temperature detector 10 toward the top plate 1. At this time, the electrical insulator 13 is configured not to protrude from the upper surface of the temperature detector 10. With this configuration, the temperature sensor 14 whose outer shell is formed of glass reduces the possibility of damaging the glass portion of the temperature sensor 14 due to the force of the spring 19 provided at the lower portion thereof, and has high heat receiving reliability. Can be performed.

  Further, by applying a silicon compound, which is a heat conductive material 20, between the heat receiving plate 15 and the temperature sensor 14 covered with the electrical insulator 13 and between the upper surface of the heat receiving plate 15 and the lower surface of the top plate 1, The heat conduction can be improved and the temperature can be detected with higher accuracy.

  Furthermore, by forming the heat receiving plate 15 with aluminum which is a nonmagnetic metal, the self-heating of the heat receiving plate 15 due to the induction heating magnetic field can be reduced, and the temperature of the cooking utensil 9 can be received with higher sensitivity. In addition, the temperature detection accuracy of the cooking utensil 9 is improved by using aluminum that has good heat conduction in terms of material properties.

  Further, by providing a heat insulating portion 21 below the heat receiving plate 15 and on the upper surface portion of the heating coil 4 and the outer periphery of the sensor holder 12, heat radiation from the temperature sensor 14 and the sensor holder 12 is prevented, and the heat conduction is performed with high sensitivity. This can be transmitted to the sensor 14, and the temperature accuracy can be improved.

  Further, by forming the heat insulating portion 21 with mica having a thickness of 0.5 mm, which is sufficiently larger than the heat receiving plate 15 so that the heat receiving plate 15 and the heating coil 4 can be electrically insulated, electric insulation performance is achieved. Can be ensured, and heat radiation of the temperature sensor 14 and the sensor holder 12 can be prevented, and the temperature detection accuracy can be improved with high sensitivity.

(Example 2)
In FIG. 4, the temperature detector 10 is arranged at the center of the heating coil 4, and the heat receiving plate 15 is extended from the center of the heating coil 4 toward the outer periphery. Thereby, the temperature of the bottom of the cooking utensil 9 in which the heating temperature distribution is generated substantially concentrically can be received with high accuracy, and the effects described above can be obtained.

(Example 3)
As shown in FIG. 5, the mounting leg 17 is provided on the heat receiving plate 15 and is attached to the sensor holder 12. Therefore, two types of temperature detectors 10 having different heat receiving performance can be easily provided by arranging or removing the heat receiving plate 15. Can be configured. For example, when the temperature detector 10 is provided at the center of the heating coil 4, there is a high possibility that the bottom of the cooking utensil 9 is located above the temperature sensor 14 even if the cooking utensil 9 is displaced. Therefore, the temperature detector 10 having the heat receiving plate 15 is disposed at the center, and the temperature detector 10 is disposed between the inner and outer heating coils. Thereby, even if the cooking utensil 9 shifts, the bottom temperature of the cooking utensil 9 can be received by the heat receiving plate 15. With such a configuration, in addition to the effect of improving the heat conduction to the temperature sensor 14 described in the first embodiment, the temperature can be detected with higher accuracy. In particular, configuring the temperature detectors 10 having different performances with the same molded product as described above has a cost merit that a molding die can be reduced.

Example 4
6 and 7, the heating coil 4 has a double spiral coil shape in which the outer coil 6 is placed around the inner coil 5, and the temperature detector 10 including the heat receiving plate 15 formed in an arc shape is replaced with the inner and outer coils. It is an induction heating cooker arranged between 5 and 6. Further, as shown in FIG. 7, the mounting holes 18 at the top of the sensor holder 12 are provided on the left and right sides of the concave groove 16.

  By arranging the temperature detector 10 between the inner and outer coils 5 and 6 and arranging the heat receiving plate 15 formed in an arc shape between the inner and outer coils 5 and 6, the inner coil 5 and the outer coil having the strongest magnetic field for induction heating. 6, the temperature detector 10 itself can be installed, and the highest temperature at the bottom of the cooking utensil 9 can be measured with higher sensitivity.

  Further, by providing the mounting hole 18 adjacent to and parallel to the concave groove 16, heat can be efficiently conducted to the temperature sensor 14 and the lead portion of the temperature sensor 14, and heat can be received with higher accuracy. Such a structure of the temperature detector can also be used in the induction heating cookers according to the first to third embodiments, thereby enabling more accurate temperature detection.

  As described above, according to the induction heating cooker according to the present invention, the accuracy of heat conduction to the temperature sensor can be improved, and accurate temperature detection can be performed. A safer induction heating cooker can be provided.

Sectional drawing which shows the structure of the induction heating cooking appliance in Example 1 of this invention. Schematic of the important note which shows the structure of the induction heating cooking appliance in Example 1 of this invention. The exploded perspective view of the temperature detector part of the induction heating cooking appliance in Example 1 of the present invention Schematic of the important note which shows the structure of the induction heating cooking appliance in Example 2 of this invention. Schematic of the important note which shows the structure of the induction heating cooking appliance in Example 3 of this invention. Schematic of the remarks which show the structure of the induction heating cooking appliance in Example 4 of this invention. The disassembled perspective view of the temperature detector part of the induction heating cooking appliance in Example 4 of this invention Schematic of the main notes showing the configuration of a conventional induction heating cooker

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top plate 2 Main body 3 Coil holder 4 Heating coil 5 Inner coil 6 Outer coil 7 Frequency conversion circuit 8 Control circuit 9 Cooking utensil 10 Temperature detector 11 Recess 12 Sensor holder 13 Electrical insulator 14 Temperature sensor 15 Heat receiving plate 16 Groove 17 Mounting leg 18 Mounting hole 19 Spring 20 Heat conduction material 21 Heat insulation part

Claims (12)

A top plate for placing the cooking utensil, a heating coil provided below the top plate, a frequency conversion circuit for supplying a high frequency current to the heating coil, and the temperature of the cooking utensil corresponding to the heating coil are adjusted to the top plate And a temperature detector for detecting the temperature of the temperature sensor, the temperature detector holding the temperature sensor with the sensor holder and thermally connecting the heat receiving plate for transferring heat from the top plate to the sensor holder in multiple paths. Induction heating cooker installed and configured. The induction heating cooker according to claim 1, wherein a part of the heat receiving plate is bent downward to form an attachment leg, and the attachment leg is inserted into an attachment hole provided in the sensor holder. The induction heating cooker according to claim 2, wherein a groove and a mounting hole for installing the temperature sensor are provided in parallel adjacent to the sensor holder. The induction heating cooker according to claim 2 or 3, wherein a plurality of mounting legs are formed. The induction heating cooker according to claim 1, wherein the heat receiving plate has a shape extending from the center to the outer periphery of the heating coil. The heating coil has a double spiral coil shape in which an outer coil is wound around the inner coil, a sensor holder is disposed between these inner and outer coils, and the heat receiving plate extends from the center of the inner coil to the outermost periphery of the outer coil. The induction heating cooker according to claim 1. The heating coil has a double spiral coil shape in which an outer coil is wound around the inner coil, a sensor holder is disposed between the inner and outer coils, and a heat receiving plate formed in an arc shape is disposed between the inner and outer coils. The induction heating cooker according to claim 1. The induction heating cooker according to claim 1, wherein a heat insulating portion is provided on an outer periphery of the sensor holder. The induction heating cooker according to claim 1, wherein a heat insulating portion is provided below the heat receiving plate and on the outer peripheral portion of the sensor holder so as to cover the outer periphery of the heat receiving plate. The induction heating cooker according to claim 1, wherein a heat conductive material is disposed between the heat receiving plate and the electric insulator covering the temperature sensor. The induction heating cooker according to claim 1, wherein a heat conductive material is disposed between the upper surface of the heat receiving plate and the lower surface of the top plate. The induction heating cooker according to claim 1, wherein the heat receiving plate is formed of a nonmagnetic metal.

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