JP2005032660A - Induction heating cooker top plate and dielectric heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the conduction of heat from a pan on the surface of a top plate, to suppress the temperature rise, and to suppress the heat conduction to the inside of the main body at the same time. In addition, it is possible to provide a safe induction heating cooker that can eliminate burn damage caused by contact with the surface, and further reduce the product cost.
By providing a spacer on the plate surface, a space can be provided between the cooking utensil and the plate surface, and heat conduction from the cooking utensil on the plate surface generating heat is reduced.
[Selection] Figure 1

Description

  The present invention relates to an induction heating cooker used for general household and business use, and in particular, a top plate that does not increase the temperature of the surface of the top plate and that is quick and safe even after cooking, and its The present invention relates to a safe induction heating cooker equipped with a top plate.

  As shown in FIG. 9, the conventional induction heating cooker has a top plate 2 installed at the top of the main body 1 and an induction heating coil 3, a temperature sensor 4, and a control circuit arranged at the bottom of the top plate 2.

In order to suppress the rise in the temperature of the surface and the rise in the temperature inside the main body, a method of inserting a heat insulating material between the top plate and the induction heating coil (Japanese Patent Laid-Open No. 6-76930), A method of providing an aluminum stay on the surface of the induction heating coil (Japanese Patent Laid-Open No. 6-60972) and the like have been devised, but none of them has sufficient performance and has not been put into practical use. In addition, the applicant separately filed an application for an invention that suppresses the temperature rise on the surface of the plate by making the plate porous and by blowing out air from the lower part of the plate. It is disadvantageous in terms of complexity and cost.
JP-A-6-76930 JP-A-6-60972

  That is, in the above-described conventional configuration, there is a problem that heat is generated due to heat generated by the cooking utensil, for example, a pan, on the surface of the top plate even during cooking or after cooking, and there is a problem that there is a high risk of burns when contacted.

  Also, during cooking, the heat of the heated cooking utensils is transferred to the inside of the main body through the top plate, and the temperature of the induction heating coil, the control board, etc. rises abnormally and causes malfunctions. A heat sink and a cooling fan are installed in the apparatus.

  The present invention solves such a conventional problem, reduces heat conduction from the cooking utensils on the top plate surface, suppresses temperature rise, and simultaneously suppresses heat conduction into the main body. It is another object of the present invention to provide a safe induction heating cooker that can eliminate burn damage caused by contact with the surface.

  In order to solve the above-described problems, the present invention includes a top plate on which a cooking utensil for heating a cooked food or the like is installed, and an induction heating coil disposed on the lower side of the top plate, and the top plate is made of a material. However, considering the antifouling property of the surface, those formed of a glass material are preferable.

  The present invention provides a spacer of an inorganic substance of at least 0.1 mm or more and 10.0 mm or less between the cooking utensil and the top plate so that the cooking utensil and the top plate do not come into direct contact with each other, resulting in the plate surface. It is possible to reduce heat transfer to the inside of the main body. More preferably, the spacer is 0.3 mm or more and 6.0 mm or less.

  Furthermore, in the present invention, it is possible to suppress heat transfer to the top plate, particularly by setting the thermal conductivity of the inorganic spacer to 42 W / (m · K) or less and the specific heat to 418 J / (kg · K) or more. . Therefore, even after cooking is completed, the transfer of heat from the spacer to the plate surface is small, and the risk of burns can be reduced without increasing the temperature of the plate surface. In addition, since heat transfer to the inside of the main body is reduced, a cooling fan is unnecessary, and the product thickness can be further reduced. Furthermore, since the plate material does not require the conventional heat resistance, the range of selection is widened and it is possible to cope with a lower cost material, leading to a reduction in the cost of the entire product.

As another preferred configuration, the present invention is the expansion of the installation spacer due to the temperature shift of the contact portion with the heated cooking utensil by using at least one of alumina, silica and zirconia as a main component. The material is limited to a material that prevents deterioration due to shrinkage.
In this spacer, the same effect can be obtained by using a porous material or a detachable spacer plate. Further, unevenness due to deformation of the plate itself is also possible.

  This not only reduces heat transfer from the cooking utensil to the top plate surface, avoids the risk of burns, but also suppresses heat transfer to the inside of the main unit, and abnormalities due to the heat of circuit components installed inside the main unit Therefore, a cheaper and safer induction heating cooker can be obtained.

  Below, the preferable form of this invention is shown.

In FIG. 1, the top plate (FIG. 2) which provided the inorganic spacer of this invention product in the upper part of a main body is installed, and the induction heating coil and the control circuit are installed in the lower part. It is assumed that the top plate is fixed by a peripheral frame.
Further, the inorganic spacer can be arranged as shown in FIG. 3, and is not particularly limited.

  Using the induction heating cooker configured as described above, the pan whose temperature rises the highest among the usual conceivables is baked, and the temperature rise of the control circuit portion that is thermally weakest in the main body is shown in FIG. The comparison was made with the conventional products shown.

  A test was performed using a conventional top plate. The portion where the top plate surface and the pan contacted was heated by heat transfer from the heated pan, and when the pan reached the maximum temperature of 750 ° C., heating was stopped and the plate surface portion was measured for temperature. It had risen above ℃. FIG. 4 shows the measured temperature region of each part of the plate, and FIG. 5 shows the temperature change. Here, the first part is the plate surface that hits the coil central part, the second part is a part away from the central part by 50 mm in the circumferential direction, the third part is a part away from the 75 mm circumferential direction, and the fourth part is a 105 mm circumferential part It is the result of measuring the temperature of the plate surface at a distance from the surface with a contact thermometer. Even after about 5 minutes, the temperature of the 2 parts and 3 parts is 150 ° C. or higher, and there is a high risk of burns when contacted.

  Using an induction heating apparatus with a conventional top plate shown in FIG. 9, water is poured into the pan, the boiling state is maintained for 15 minutes after boiling, the dielectric heating is stopped, and the temperature of the plate surface is set in the same manner as in Example 1. It was measured. The temperature change of each part is shown in FIG.

  A similar test was performed with a dielectric heating apparatus equipped with the top plate of the present invention. Five spacers of 20 mm in diameter were applied to the portion corresponding to the induction heating portion so that the spacer made of alumina was about 1 mm in height, and was installed in the induction heating apparatus in the same manner as in the above example.

  Using the induction heating apparatus in which the top plate of the present invention shown in FIG. 1 was installed, the same pan burning test as in Example 1 was performed. The temperature measurement result of each part in FIG. 4 was very low compared to the conventional plate, and the temperature of each part on the top plate surface reached 60 ° C. or less after 3 minutes. The measurement result of temperature is shown in FIG.

  Using the top plate of the present invention, the same test as in Example 3 was performed to measure the temperature of each part on the top plate surface. Even in this test, the temperature dropped to 70 ° C. or lower in all the parts compared to the conventional top plate after 5 minutes. The temperature change of each part is shown in FIG.

  From the above results, by installing the product of the present invention in a dielectric heating cooker, compared to the current product, it suppresses the rise in temperature and reduces the occurrence of burns due to the temperature drop after cooking. Can be designed. In addition, a cheaper material can be selected as compared with an expensive material such as current crystallized glass. For example, the cheapest soda glass, a non-magnetic metal such as aluminum, or a resin plate can be used. Furthermore, since the maximum temperature of the circuit portion is lowered due to the heat insulating effect between the plate and the air layer, it is possible to employ inexpensive electronic components with lower heat resistance.

It is sectional drawing of the induction heating cooking appliance of one Example of this invention. It is a fragmentary view of the top plate of the present invention. It is a top view which shows the other Example of the top plate of this invention. It is explanatory drawing which shows the temperature measurement position in an Example. 3 is a graph showing changes in temperature in Example 1. 6 is a graph showing changes in temperature in Example 2. 6 is a graph showing changes in temperature in Example 4. 10 is a graph showing changes in temperature in Example 5. It is sectional drawing of the conventional induction heating cooking appliance.

Explanation of symbols

1 Body 2 Top plate 3 Induction heating coil 4 Temperature sensor 5 Cooling fan 6 Control device 7 Spacer

Claims (4)

  A top plate for an induction heating cooker comprising a spacer having a thickness of 0.1 mm or more and 10.0 mm or less on all or a part of a cooking appliance installation portion on the surface of the top plate of the dielectric heating cooker.   The top plate for an induction heating cooker having a spacer according to claim 1, wherein the spacer has a thermal conductivity of 42 W / (m · K) or less and a specific heat of 418 J / (kg · K) or more.   The top plate for an induction heating cooker according to claim 1, wherein the spacer is made of a material mainly composed of at least one of alumina, zirconia, and silica. The induction heating cooking appliance which mounts the top plate in Claims 1-3.

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