JP2001230062A - Induction heating cooking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooking device that can detect in good precision the temperature of a cooking pot put on a top plate. SOLUTION: The cooking device comprises a cooking pot 20 which cooks the heated object by heating, a heat sensing plate 22 made of a material of high thermal conductivity which collects the temperature of the cooking pot, a temperature detective means 24 made of a thermistor which detects the temperature of the heat sensing plate 22 and a control means 25 which controls the electricity supplied to the heating coil in accordance with the output of the temperature detecting means 24. As the temperature of the cooking pot 20 is collected by the heat sensing plate of high thermal conductivity and the temperature of this heat sensing plate 22 is measured by the temperature detecting means 24 made of a thermistor, the precision of temperature measuring of the cooking pot is greatly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker capable of accurately detecting the temperature of a pan on a top plate.

[0002]

2. Description of the Related Art In an induction heating cooker for heating an object to be heated such as a pan, as a method of detecting the temperature of the pan of the object to be heated, a method of detecting the temperature with a thermistor via a top plate on which the pan is placed. There is. There is also known a method using a temperature-sensitive plate which further improves the temperature detection accuracy than this method. This conventional example will be described with reference to FIG.

A top plate 2 made of a non-magnetic material is mounted on an upper surface of a main body 1 of the device. A heating coil 3 is arranged below the top plate 2, and a high-frequency current is supplied to the heating coil 3 to heat the pot 4 placed on the top plate 2 by induction. A temperature-sensitive plate 5 having high thermal conductivity and high electrical insulation is adhered to the lower surface of the top plate 2. The temperature sensing plate 5 collects heat transmitted through the top plate 2 to the temperature of the induction-heated pot 4. The temperature of the heating plate 5 can be measured by detecting the temperature of the temperature-sensitive plate 5 by the temperature detecting means 6 composed of a thermistor. The control means 7 controls the electric power of the heating coil 3 according to the signal of the temperature detection means 6, and controls the pan 4 to a predetermined temperature.

There is also known a method of detecting infrared rays emitted from the pan 4 to detect the temperature at the bottom of the pan. This conventional example will be described with reference to FIG.

[0005] A main body 11 is provided with a magnetic generating coil 13 for heating the pan 12 and an infrared sensor 14 for detecting temperature. The top plate 15 provided on the upper surface of the main body 11 has an infrared transmitting portion 16 that transmits infrared light at a portion facing the infrared sensor 14, and the other portion of the infrared transmitting portion 16 is covered with an opaque layer 17. Infrared light radiated from the pan 12 is transmitted by the infrared transmitting portion 16 of the top plate 15, and the infrared sensor 14 measures the temperature of the pan 11.

[0006]

In the conventional induction heating cooker shown in FIG. 8, the temperature sensing plate 5 receives heat via the top plate, and the temperature of the temperature sensing plate 5 is detected. The top plate 2 made of ceramic has a low heat transfer coefficient, and a delay in the thermal response of the top plate 2 causes an error with the actual temperature of the object to be heated.

In the conventional induction heating cooker shown in FIG. 9, infrared rays radiated from the pan 12 are transmitted through the top plate 15 and detected. Cooking pot 1 in general
The temperature of No. 2 is about 30 ° C. to 230 ° C., and the peak wavelength at this temperature is 10 μm to 6 μm according to the Stefan-Boltzmann law. The wavelength that the top plate 15 can transmit is in the near-infrared region of 2.5 microns or less, and even if this wavelength is detected, measuring the temperature during cooking tends to cause measurement errors.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a pot for heating and cooking an object to be heated, a heating coil for heating the pot, a temperature plate for collecting the temperature of the pot, and a pot via the temperature plate. A top plate, a temperature detecting means for detecting the temperature of the temperature-sensitive plate, and a control means for controlling electric power supplied to the heating coil according to the output of the temperature detecting means. This is an induction heating cooker whose temperature can be measured.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to the first aspect of the present invention is to accurately detect the temperature of a pan by detecting the temperature of a thermosensitive plate for collecting the temperature of the pan and controlling the power supplied to a heating coil. Is an induction heating cooker that can measure.

According to a second aspect of the present invention, the top plate is provided with a heat insulating material between the top plate and the temperature sensing plate to reduce heat radiation of the temperature sensing plate and to measure the temperature of the pot with high accuracy. It is a heating cooker.

[0011] In the invention described in claim 3, the top plate is provided with a cushioning material between the top plate and the temperature-sensitive plate to eliminate a gap formed between the top plate and the temperature-sensitive plate to prevent spillage of boiling juice and the like. Then, the induction heating cooker can measure the temperature of the pot with high accuracy.

According to a fourth aspect of the present invention, there is provided an induction heating cooker in which the temperature sensing plate has a diameter equal to or less than the diameter of the heating coil and collects the temperature of the pan to accurately measure the temperature of the pan.

According to a fifth aspect of the present invention, there is provided an induction heating cooker in which the temperature-sensitive plate is set to have a radius substantially equal to or more than half of the radius of the heating coil to collect the temperature of the pan and to accurately measure the temperature of the pan. And

According to a sixth aspect of the present invention, there is provided an induction heating cooker wherein the temperature detecting means detects infrared rays radiated from the temperature-sensitive plate and measures the temperature to measure the temperature of the pot with high accuracy. I have.

[0015]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a block diagram showing the configuration of this embodiment. The induction heating cooker of the present embodiment includes a pot 20 for heating and cooking an object to be heated, and a heating coil 21 for heating the pot 20.
A temperature-sensitive plate 22 made of a material having a high thermal conductivity (for example, aluminum nitride) for collecting the temperature of the pan 20, and a concave portion into which the temperature-sensitive plate 22 is placed so that the top surface on which the pan 20 is placed becomes flat. A top plate 23 having a shape, a temperature detecting means 24 comprising a thermistor which comes into contact with the lower surface of the temperature sensing plate 22 through a central hole 23a of the top plate 23 and detects the temperature, and a heating coil according to the output of the temperature detecting means 24 And control means 25 for controlling the electric power supplied to the power supply 21.

In the first embodiment, when a power supply (not shown) is turned on and a predetermined temperature is set by an operation switch,
The control means 25 supplies electric power to the heating coil 21. When electric power is supplied to the heating coil 21, the heating coil 21
Generates an induction magnetic field from the pan 2 on the top plate 23.
0 is induction heated. By this induction heating, the temperature of the pan 20 rises, and the object to be heated in the pan 20 is cooked. Here, the shapes of the temperature sensing plate 22 and the top plate 23 will be described. The top plate 23 is formed as a paragraph in a concave shape, and the temperature sensing plate 22 is fitted into the concave portion. The top plate 23 has a flat top surface so that the pan 20 can be easily placed. When the heating of the pan 20 is started by the heating coil 21, the temperature-sensitive plate 22 provided under the pan 20 and made of a material having a high thermal conductivity collects heat. Becomes Temperature detecting means 24 composed of a thermistor is attached to the lower surface of the temperature-sensitive plate 22 and detects the temperature of the temperature-sensitive plate 22. The temperature detecting means 24 converts the temperature of the temperature sensitive plate 22 into an electric signal and sends it to the control means 25. The control means 25 controls the electric power supplied to the heating coil 21 in accordance with the temperature signal to control the temperature to a predetermined pan temperature. By collecting the temperature of the pan 20 with the temperature-sensitive plate 22 in this manner, the temperature of the pan 20 can be controlled, and the object to be heated can be cooked.

In the first embodiment, in particular, the temperature of the pot 20 is collected by the temperature-sensitive plate 22 having high thermal conductivity, and the temperature of the temperature-sensitive plate 22 is measured by the temperature detecting means 24 comprising a thermistor. The temperature measurement can be realized with a temperature close to the above temperature and a quick response.

In the first embodiment, a material having a high thermal conductivity such as aluminum nitride is used for the material of the temperature sensitive plate 22.
A similar effect can be obtained with alumina or silicon, and the invention is not limited to a single material.

(Embodiment 2) FIG. 2 is a block diagram showing the configuration of Embodiment 2 of the present invention. The induction heating cooker according to the present embodiment is different from the first embodiment only in that a heat insulating material is provided between the top plate and the temperature sensing plate, and the other portions having the same configuration and operation and effect have the same reference numerals. , Detailed description is omitted, and different points are mainly described. Reference numeral 26 denotes a heat insulating material made of a material having a low thermal conductivity between the top plate 23 and the temperature sensitive plate 22.

In the second embodiment, the heat transmitted from the pan 20 is collected by the temperature sensing plate 22 and detected by the temperature detecting means 24 in contact with the lower surface thereof. Since the temperature sensing plate 22 is in contact with the top plate 23, the heat of the temperature sensing plate 22 is also transmitted to the top plate 23. In other words, the temperature of the pan 20 is radiated not only to the temperature-sensitive plate 22 but also to the top plate 23, and the radiation causes a detection delay. However, the heat insulating material 26 is provided on the lower surface of the temperature-sensitive plate 22 and can prevent the heat of the temperature-sensitive plate 22 from radiating to the top plate 23. The delay between the temperature of the pan 20 and the temperature of the temperature sensitive plate 22 can be reduced.

As described above, according to the second embodiment, the heat insulating material 26 prevents the heat of the temperature sensitive plate 22 from being transmitted to the top plate 23, thereby improving the responsiveness of the temperature sensitive plate. Therefore, an induction heating cooker with high measurement accuracy can be realized.

(Embodiment 3) FIG. 3 is a block diagram showing a configuration of Embodiment 3 of the present invention. The induction heating cooker of the present embodiment is different from that of the first embodiment only in that a cushioning material is provided between the top plate and the temperature sensing plate, and the other portions having the same configuration and operation and effect have the same reference numerals. , Detailed description is omitted, and different points are mainly described. 27 is a cushioning material for eliminating a gap between the top plate 23 and the temperature sensitive plate 22;
As shown in the figure, the gap between the temperature sensing plate 22 and the top plate 23 is filled on the lower surface and the peripheral end surface.

In the third embodiment, the cushioning material 27 is provided between the top plate 23 and the temperature sensitive plate 22, and a cushioning material made of ceramic paint or the like is used to prevent a gap formed therebetween. When boiling water or the like is spilled from the pan 20, there is a possibility that the broth may enter through a gap between the temperature sensing plate 22 and the top plate 23 and reach the heating coil 21. The buffer material 27 fills the gap between the top plate 23 and the temperature-sensitive plate 22, which is the cause of the above, so that the intrusion of boiling water or the like can be prevented. The cushioning material 27 absorbs the difference in the coefficient of thermal expansion between the top plate 23 and the temperature-sensitive plate 22 and can be securely attached. The top surface of the top plate 23 can be flattened.

As described above, according to the third embodiment, the gap between the top plate and the temperature-sensitive plate is eliminated to prevent the spilling of the broth or the like, and the temperature of the pot can be measured with high accuracy.

The cushioning member 27 only needs to prevent the gap between the top plate 23 and the temperature-sensitive plate 22, and the same effect can be obtained by using a ceramic-based adhesive material or an organic adhesive material.

(Embodiment 4) FIG. 4 is a block diagram showing the configuration of Embodiment 4 of the present invention. The induction heating cooker of this embodiment is different from the first embodiment only in that the temperature sensing plate is smaller than the diameter of the heating coil. The same reference numerals are given and detailed description is omitted, and different points will be mainly described. Thermal plate 2
Reference numeral 2 denotes a shape not larger than the diameter of the heating coil 21.

In the fourth embodiment, the magnetic flux for induction heating the pan 20 is determined by the diameter of the heating coil 21. The electric power to the pan 20 is intensively supplied within this diameter. Pot 20
The portion to be heated is less than the diameter of the heating coil 21. If a temperature sensing plate is provided below this diameter, the temperature of the pan 20 can be detected in a concentrated manner.

As described above, according to the fourth embodiment, the diameter of the temperature sensing plate 22 is set to be equal to or less than the diameter of the heating coil 21 so that the temperature of the pan 20 can be detected with certainty. A cooker can be realized.

(Embodiment 5) FIG. 5 is a block diagram showing the configuration of Embodiment 5 of the present invention. FIG. 6 is a diagram showing the power density of induction heating according to the fifth embodiment of the present invention. The induction heating cooker according to the present embodiment is different from the first embodiment only in that the temperature sensing plate is characterized in that it is substantially half or more of the radius of the heating coil.
The other portions having the same configuration and operation and effect are denoted by the same reference numerals, detailed description thereof will be omitted, and different points will be mainly described. The temperature sensing plate 22 has a shape that is substantially half or more of the radius of the heating coil 21.

In the fifth embodiment, the relationship between the power density of the induction heating of the heating coil 21 and the pot 20 will be described with reference to FIG. Pan 20 placed on top plate 23 is heated by induction power from heating coil 21. At this time, the power density of the pan 20 is supplied at a peak at a position approximately half the radius of the heating coil 21. The pot 20 shows a similar temperature distribution with this power density. By making the temperature sensing plate 22 half or more of the radius of the heating coil 21, it is possible to reliably collect heat from the highest temperature position of the pot 20.

As described above, according to the fourth embodiment, the temperature of the pan 20 can be reliably detected by setting the diameter of the temperature sensing plate 22 to be equal to or more than half the radius of the heating coil 21, and the induction with high measurement accuracy can be achieved. A heating cooker can be realized.

(Embodiment 6) FIG. 7 is a block diagram showing the configuration of Embodiment 6 of the present invention. The induction heating cooker according to the present embodiment is different from the first embodiment only in that the temperature detecting means is provided with a non-contact temperature detecting means for detecting infrared rays emitted from the temperature sensitive plate and measuring the temperature. The same reference numerals are given to portions having the same configuration and operation and effect other than those described above, detailed description is omitted, and different points will be mainly described. 28 is the temperature sensing plate 22
This is a non-contact temperature detecting means composed of a thermopile for detecting a temperature by detecting infrared rays emitted from the device.

In the sixth embodiment, the non-contact temperature detecting means 28 is provided below the temperature sensing plate 22 and faces the lower surface of the temperature sensing plate 22. The temperature sensing plate 22 emits infrared light having a peak wavelength according to the temperature. Non-contact temperature detecting means 28 made of a thermopile
However, the temperature sensing plate 22 is directly detected. Non-contact temperature detection means 2
Numeral 8 converts the amount of infrared rays into a temperature signal to measure the surface temperature of the temperature sensitive plate 22. The non-contact temperature detecting means includes:
The temperature signal is sent to the control means 25. The control means 25 controls the electric power supplied by the heating coil 21 so that the pan 20 can be controlled to a predetermined temperature.

As described above, according to the sixth embodiment, since the non-contact temperature detecting means 28 directly detects the temperature of the thermosensitive plate 22, the non-contact temperature detecting means 28 detects the infrared radiation radiated from the thermosensitive plate 22 without attenuating it. And the temperature can be measured, and a highly accurate induction heating cooker can be realized.

In the embodiment, the non-contact temperature detecting means 28
Although the configuration of an infrared sensor using a thermopile is used, similar effects can be obtained with an infrared sensor such as a ceramic bulk element or a thin-film pyroelectric element.

[0036]

As described above, the invention according to claim 1 of the present invention comprises a pot for heating and cooking an object to be heated, a heating coil for heating the pot, and a thermosensitive plate for collecting the temperature of the pot. A top plate on which a pan is placed via a temperature sensing plate, temperature detection means for detecting the temperature of the temperature sensing plate, and control means for controlling electric power supplied to the heating coil according to the output of the temperature detection means. It is equipped with, collecting the temperature of the pot with a thermosensitive plate with high thermal conductivity,
Since the temperature of the temperature sensing plate is measured by the temperature detecting means including the thermistor, an induction heating cooker capable of measuring the temperature with a temperature close to the temperature of the pan and a quick response can be realized.

Further, the invention described in claim 2 is provided with a heat insulating material between the top plate and the temperature sensitive plate, so that the heat radiation of the temperature sensitive plate is reduced and the temperature of the pot is measured with high accuracy. An induction heating cooker that can do this can be expected.

Further, the invention according to claim 3 is provided with a cushioning material between the top plate and the temperature-sensitive plate, and eliminates a gap formed between the top plate and the temperature-sensitive plate to remove boiling water or the like. An induction heating cooker that prevents the spill and can measure the temperature of the pot with high accuracy can be realized.

Further, according to the invention described in claim 4, the temperature sensing plate has a diameter equal to or less than the diameter of the heating coil, and collects the temperature of the pot so that the temperature of the pot can be measured with high accuracy.

According to a fifth aspect of the present invention, the temperature sensing plate is set to be at least approximately half the radius of the heating coil to collect the temperature of the pan and to accurately measure the temperature of the pan. is there.

According to a sixth aspect of the present invention, the temperature detecting means measures the temperature by detecting the infrared rays emitted from the temperature-sensitive plate, so that the temperature of the pot can be measured with high accuracy. Vessel can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an induction heating cooker according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an induction heating cooker according to a second embodiment.

FIG. 3 is a block diagram illustrating an induction heating cooker according to a third embodiment.

FIG. 4 is a block diagram showing an induction heating cooker according to a fourth embodiment.

FIG. 5 is a block diagram showing an induction heating cooker according to a fifth embodiment.

FIG. 6 is a diagram showing an induction heating cooker and its power density in a sixth embodiment.

FIG. 7 is a block diagram illustrating an induction heating cooker according to a sixth embodiment.

FIG. 8 is a block diagram showing a conventional induction heating cooker.

FIG. 9 is a block diagram showing an induction heating cooker in another conventional example.

[Explanation of symbols]

 Reference Signs List 20 pan 21 heating coil 22 temperature sensing plate 23 top plate 24 temperature detecting means 25 control means 26 heat insulating material 27 buffer material 28 non-contact temperature detecting means

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Izumi Hirota 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Takahiro Miyauchi 1006 Odaka Kadoma Kadoma City Osaka Pref. (72) Inventor Yu Fukuda 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 3K051 AB02 AC09 AC33 AC42 AD02 AD04 BD02 CD14 CD42 CD44 CD45

Claims (6)

[Claims] 1. A pot for heating and cooking an object to be heated, a heating coil for heating the pot, a temperature plate for collecting the temperature of the pot, a top plate for placing the pot via the temperature plate, An induction heating cooker comprising: temperature detecting means for detecting a temperature of a temperature sensing plate; and control means for controlling electric power supplied to a heating coil according to an output of the temperature detecting means. 2. The induction heating cooker according to claim 1, wherein the top plate is provided with a heat insulating material between the top plate and the temperature sensing plate. 3. The induction heating cooker according to claim 1, wherein the top plate is provided with a buffer between the top plate and the temperature sensing plate. 4. The induction heating cooker according to claim 1, wherein the temperature sensing plate has a diameter equal to or less than a diameter of the heating coil. 5. The induction heating cooker according to claim 1, wherein the temperature sensing plate is at least approximately half the radius of the heating coil. 6. The induction heating cooking device according to claim 1, wherein the temperature detecting means includes a non-contact temperature detecting means for measuring a temperature by detecting infrared rays emitted from the temperature sensitive plate. vessel.