JP3997891B2 - Induction heating cooker - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to an induction heating cooker that can accurately detect the temperature of a pan on a top plate.
[0002]
[Prior art]
In an induction heating cooker that heats an object to be heated such as a pot, as a method of detecting the temperature of the pot of the object to be heated, there is a method of detecting the temperature with a thermistor through a top plate on which the pot is placed. There is also a method of detecting temperature using infrared rays.
[0003]
[Patent Document 1]
JP 2002-75624 A
[Problems to be solved by the invention]
In an induction heating cooker having a conventional configuration, a thermistor receives the temperature of a pan through a top plate and detects the temperature. Here, the top plate 2 made of ceramic has a low heat transfer coefficient, and due to a delay in the thermal response of the top plate 2, an actual pan temperature and error occur, and the temperature of the object to be heated cannot be accurately detected. It is.
[0005]
[Means for Solving the Problems]
The present invention includes a top plate on which a pan is placed, a heating coil that heats the pan by electromagnetic induction, an inverter that supplies high-frequency current to the heating coil, and an infrared ray that is placed in the center of the top plate and transmits infrared rays from the pan. An infrared detecting means for detecting infrared rays that have passed through the transmitting part, and a correcting means for correcting the output of the infrared detecting means, when the emissivity is known from room temperature or 100 degree stable. When the output of the infrared detection means is reduced due to the displacement of the top plate , the correction means is an induction heating cooker that corrects the output of the infrared detection means .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 includes a top plate on which the pan is placed, a heating coil that heats the pan by electromagnetic induction, an inverter that supplies high-frequency current to the heating coil, and a central plate that is disposed in the center of the top plate. a transmitting unit which transmits infrared, and infrared detection means for detecting the infrared rays having passed through the transparent portion, and a correcting means for correcting the output of said infrared detection means, the normal temperature from the pot emissivity is known or When the output of the infrared detection means at 100 degree stability is decreased due to the displacement of the top plate , the correction means can correct the output of the infrared detection means, thereby accurately adjusting the temperature of the pan. It becomes an induction heating cooker that can be detected.
[0007]
Since the invention described in claim 2 has a coating that does not affect the infrared transmission wavelength region on the lower surface of the transmission portion, the transmission portion can be emphasized and the user can be more conscious of removing dirt. An induction heating cooker capable of measuring temperature can be realized.
[0008]
【Example】
Example 1
The first embodiment of the present invention will be described below. FIG. 1 is a block diagram showing the configuration of this embodiment. The induction heating cooker of the present embodiment supplies a high frequency current to the pan 1 for cooking the object to be heated, the top plate 2 on which the pan 1 is placed, the heating coil 3, and the heating coil 3, and electromagnetic induction is applied to the pan 1. Inverter 4 which generates heat, transmission part 5 which transmits infrared rays, infrared detection means 6, amplification means 7, correction means 8 and control means 9 are provided.
[0009]
In the first embodiment, when a power supply (not shown) is turned on and a predetermined temperature is set with the operation switch, the control means 9 supplies power to the heating coil 3. When electric power is supplied to the heating coil 3, an induction magnetic field is generated in the heating coil 3, and the pan 1 on the top plate 2 is induction-heated. Due to this induction heating, the temperature of the pan 1 rises and the object to be heated in the pan 1 is cooked. Here, the shape of the transmission part 5 and the top plate 2 will be described.
[0010]
The transmission part 5 is made of Si, quartz, sapphire or the like having a high transmittance with respect to an infrared wavelength region of about 0 to 300 degrees. Here, when heating of the pan 1 is started by the heating coil 3, infrared rays corresponding to the temperature of the pan 1 are transmitted through the transmission portion 5 provided under the pan 1. The infrared detection means 6 detects this infrared ray and outputs a signal corresponding to the amount of infrared ray to the amplification means 7. The amplifying means 7 amplifies the signal, outputs it to the control means 9, determines the temperature of the pan 1 by the control means 9, and controls the inverter 4 to control the electric power so that the predetermined temperature is set. is there. Here, when the top plate 2 is displaced, the infrared rays transmitted through the transmission portion 5 are reduced. Due to the decrease, it is detected that the temperature is lower than the actual pan temperature. This deviation may be a dimensional error of the top plate 2 or a deviation during assembly. Therefore, a pan whose emissivity is known at the time of initial stabilization is installed at room temperature or when it is stable at 100 degrees, and the output of the infrared detection means in that case is corrected by the correction means 8. As a result, the temperature of the pan 1 can always be detected quickly and accurately by the amount of infrared rays that has passed through the transmission part, whereby the temperature of the pan 1 can be controlled and the object to be heated can be cooked.
[0011]
(Example 2)
FIG. 2 is a block diagram showing the configuration of the second embodiment of the present invention. The induction heating cooker of the present embodiment is different from the first embodiment only in the shape of the transmission part and the correction means, and other parts having the same configuration and effect are given the same reference numerals and detailed description is omitted. However, the differences will be mainly described.
[0012]
In the second embodiment, the transmission part 10 has a diameter sufficiently larger than the visual field range of the infrared detection means 6. That is, the field of view of the infrared detecting means 6 is limited to about φ5 mm on the top plate 2, but the transmission part 10 is φ15 mm. For this reason, the amount of infrared rays passing through the transmitting portion 10 is the same even when the top plate or the support plate below the infrared detecting means 6 is displaced. For this reason, the temperature of the pan 1 can always be controlled quickly and accurately by detecting the temperature of the pan 1 with the amount of infrared rays that has passed through the transmission part, and the object to be heated can be cooked.
[0013]
Further, as shown in FIG. 3, the lower surface of the transmission window may be coated. Sapphire, Si, and the like used for the transmission window have high purity, and the coloring material cannot be embedded directly. In order to show the user the presence of the transmissive window and to be aware of care such as wiping off dirt, it is effective to visually recognize it by coloring. Therefore, it can be emphasized by coating the lower surface of the transmission window with a coating that does not affect the infrared transmission wavelength range. As a result, the temperature of the pan can be continuously detected accurately.
[0014]
【The invention's effect】
According to the present invention as described above, the dimension accuracy, when without being affected by variations in assembly, in which the induction heating cooker capable of detecting the temperature of the pot in a precise and fast response can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an induction heating cooker in Embodiment 1 of the present invention. FIG. 2 is a block diagram showing an induction heating cooker in Embodiment 2. FIG. 3 is a block diagram showing an induction heating cooker in Embodiment 3. FIG. 4 is a block diagram showing an induction heating cooker in a conventional example.
DESCRIPTION OF SYMBOLS 1,12 Pan 2,13 Top plate 3 Heating coil 4 Inverter 5, 10 Transmission part 6 Infrared detection means 7 Amplification means 8 Correction means 9 Control means 11 Coating

Claims (2)

A top plate for placing the pan, a heating coil for heating the pan by electromagnetic induction, an inverter for supplying high-frequency current to the heating coil, and a transmission portion arranged at the center of the top plate for transmitting infrared light from the pan Infrared detection means for detecting infrared rays that have passed through the transmission part, and correction means for correcting the output of the infrared detection means, and detecting the infrared rays at a normal temperature from a pan whose emissivity is known or at 100 degree stability When the output of the means decreases due to the displacement of the top plate , the correction means is an induction heating cooker that corrects the output of the infrared detection means . The induction heating cooker according to claim 1 , wherein a coating that does not affect the infrared transmission wavelength region is applied to the lower surface of the transmission part.

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