JP4120696B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker that can accurately detect the temperature of a pan on a top plate.

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.
JP 2002-75624 A

  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.

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 a high-frequency current to the heating coil, and an infrared ray that is disposed under the top plate and is emitted from the pan and infrared detection means for detecting, and a control means for inputting a signal to said infrared detection means, the infrared ray detecting means is formed in a cylindrical cavity of the top plate near encloses the sensor element to the sensor element the cases are arranged near the inside center of the heating coil, and, by installing the filter for attaching the dirt inside the device between the top plate lower surface and the case upper and the dirt on the sensor element in which the amount of infrared rays to the sensor element by the dirt that adheres rather name is an induction heating cooker is characterized in that so as not to decrease.

  As described above, according to the present invention, dirt can be prevented from entering the infrared transmission path of the infrared detecting means, so that an induction heating cooker that can stably and quickly measure temperature can be realized. It is.

(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. It comprises an inverter 4 that generates heat, an infrared detection means 5 that detects infrared rays from the pan, an amplification means 6, a control means 7, and a filter 8.

  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 7 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, 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 top plate under the pan 1. The infrared detection means 5 detects this infrared ray and outputs a signal corresponding to the amount of infrared ray to the amplification means 6. The amplifying means 6 amplifies the signal, outputs it to the control means 7, determines the temperature of the pan 1 by the control means 7, and controls the inverter 4 to control the electric power so that the predetermined temperature is set. is there. The infrared detection means 5 has a case made of, for example, aluminum and includes a sensor element, and a cylindrical cavity extends from the top 2 to the element. For this reason, dust inside the equipment or oil contained in the outside air taken in for cooling adheres. For this reason, a filter 8 for attaching dirt is provided between the bottom surface of the top plate and the upper part of the aluminum case of the infrared detecting means. Since the filter does not attach dirt to the element, the amount of infrared rays does not decrease due to the dirt. As a result, the temperature of the pan 1 can be detected quickly and accurately stably for a long time.

  In addition, this filter can be used by removing the top plate and replacing it so that the effect of removing dirt can be maintained for a long time.

(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 that of the first embodiment only in the configuration of the infrared detection means, and other parts having the same configuration and operational effects are denoted by the same reference numerals and detailed description thereof is omitted. The difference will be mainly described. Reference numeral 9 denotes a lens barrel.

  In the second embodiment, the infrared detecting means 5 has a case made of, for example, aluminum, includes a sensor element, and a cylindrical cavity from the top 2 to the element. A lens barrel 9 is provided in a cylindrical cavity so that infrared light incident from above does not attenuate before reaching the element. For this reason, the amount of infrared rays is not reduced, and the temperature of the pan 1 can be detected quickly and accurately.

(Example 3)
FIG. 3 is a block diagram showing the configuration of the third embodiment of the present invention. The induction heating cooker of the present embodiment is different from that of the first embodiment only in the configuration of the heating coil, and other parts having the same configuration and operational effects are denoted by the same reference numerals and detailed description thereof is omitted and different. The explanation will focus on the points. 10 is ferrite.

  In the third embodiment, the heating coil 3 generates a high frequency magnetic field. Here, the magnetic flux is converged in the lower part of the heating coil by the ferrite 10 installed on the lower surface of the heating coil 3. However, when the infrared detection means is installed near the inner center of the heating coil 3, even if the case is made of aluminum that is difficult to be induction-heated, a small induction current flows, the aluminum case self-heats, and the sensor Temperature is affected.

  Also, noise due to the magnetic field is generated. Therefore, in the present invention, by installing this ferrite inside the heating coil, these influences can be eliminated, and the induction cooking device can stably detect the temperature of the pan stably.

Example 4
FIG. 4 is a configuration diagram of Embodiment 4 of the present invention. The induction heating cooker of the present embodiment is different from that of the first embodiment only in the configuration of the infrared detection means, and other parts having the same configuration and operational effects are denoted by the same reference numerals and detailed description thereof is omitted. The difference will be mainly described. 11 is a resin part, 12 is an aluminum part.

  In the fourth embodiment, the infrared detecting means 5 has an upper part of the case constituted by the resin part 11 having low heat conduction and a lower part constituted by the aluminum part 12 having high heat conduction. The sensor element is included in the aluminum part 12, and temperature unevenness does not occur around the element.

  Moreover, although the temperature of a top plate becomes high during cooking, even if this temperature is radiated to the resin part 11, since heat conduction is low, it is hard to be transmitted to the aluminum part in which the element is included. As a result, for example, when the element is a thermopile, the temperature of the object, i.e., pan, can be measured from the difference between the temperature of the element itself and the amount of incident infrared rays. Highly accurate and stable temperature detection is possible.

  Moreover, as shown in FIG. 5, it can be made not to receive the influence of the temperature of a top plate by flowing cooling air from the lower part of an infrared detection means.

  Furthermore, as shown in FIG. 6, by covering the infrared detecting means with the heat insulating portion 13, it is possible to further eliminate the influence of the temperature change of the top plate and the surroundings.

(Example 5)
FIG. 7 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 for generating heat, infrared detecting means 5 for detecting infrared rays from the pan, amplifying means 6, control means 7, and black tube portion 14 are provided.

  In the fifth embodiment, when a power supply (not shown) is turned on and a predetermined temperature is set with the operation switch, the control means 7 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, 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 top plate under the pan 1. The infrared detection means 5 detects this infrared ray and outputs a signal corresponding to the amount of infrared ray to the amplification means 6. The amplifying means 6 amplifies the signal, outputs it to the control means 7, determines the temperature of the pan 1 by the control means 7, and controls the inverter 4 to control the electric power so that the predetermined temperature is set. is there. The infrared detection means 5 has a case made of, for example, aluminum, includes a sensor element, and includes a black copper portion 14 from the top plate 2 to the element, so that infrared light is not reflected on the side surface. . For this reason, the viewing angle of the infrared rays that enter and reach the sensor element can be narrowed, and the center portion of the pan bottom can be spot-detected. Or even if dirt adheres, since reflection is not required, there is almost no influence and the amount of infrared rays does not fall. As a result, the temperature of the pan 1 can be detected quickly and accurately stably for a long time.

(Example 6)
FIG. 8 is a configuration diagram of Embodiment 6 of the present invention. The induction heating cooker of the present embodiment is different from the first embodiment only in the configuration of the top plate, and other parts having the same configuration and operational effects are denoted by the same reference numerals and detailed description thereof is omitted and different. The explanation will focus on the points. Reference numeral 15 denotes a transmission window.

  In the said Example 6, the transmissive window is installed in the top plate. The transmission window 15 is made of sapphire or the like having a high transmittance with respect to an infrared wavelength region of about 0 to 300 degrees. For this reason, the amount of infrared rays entering the infrared detection means 5 can be increased, and the gain of the amplifying unit 6 can be lowered by several hundred times as compared with the time when the top plate is interposed, so that the influence of noise and the like can be reduced. As a result, the temperature of the pan 1 can be detected with higher accuracy, and the thermal power can be controlled in accordance with various menus.

The block diagram which shows the induction heating cooking appliance in Example 1 of this invention. The block diagram which shows the induction heating cooking appliance in Example 2 The block diagram which shows the induction heating cooking appliance in Example 3 The block diagram which shows an example of the induction heating cooking appliance in Example 4. The block diagram which shows an example of the induction heating cooking appliance in Example 4. The block diagram which shows an example of the induction heating cooking appliance in Example 4. The block diagram which shows the induction heating cooking appliance in Example 5 The block diagram which shows the induction heating cooking appliance in Example 6 The block diagram which shows the induction heating cooking appliance in a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,16 Pan 2,17 Top plate 3 Heating coil 4 Inverter 5 Infrared detection part 6 Amplifying means 7 Control means 8 Filter 9 Lens tube 10 Ferrite 11 Resin part 12 Aluminum part 13 Heat insulation part 14 Black cylinder part 15 Transmission window 18 Thermistor

Claims (2)

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 an infrared ray that is disposed under the top plate and detects infrared rays from the pan detection means, and control means for inputting a signal to said infrared detection means, said infrared detection means, the cases that are formed in the cylindrical cavity from the top plate near encloses the sensor element to the sensor element wherein disposed inside the vicinity of the center of the heating coil, and, by installing the filter for attaching the dirt inside the device between the top plate lower surface and the case upper, that the dirt adheres to the sensor element induction heating cooker wherein the amount of infrared rays to the sensor element was prevented from being lowered by do rather the dirt. 2. The induction heating cooker according to claim 1, wherein the infrared detection means includes an upper part of the case made of a resin part having a low thermal conductivity and a lower part of the case made of an aluminum part having a high thermal conductivity .

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