JP2012014835A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooker that prevents a metal pin of a thermopile having a thermistor for temperature correction incorporated from being thermally affected.SOLUTION: The induction heating cooker includes a main body 1, a top plate 2, a heating coil unit 200, a cooling fan 401, and a duct 408 which guides cooling air 406, and an infrared sensor module 407 which stores the thermopile 12 receiving infrared light from a pan 501 and a printed wiring board 27 at a bottom part 16d of a resin case 16, and is covered with a magnetic shielding case 13, wherein, in the duct 408, a fixed member 211 comprising an upper surface 211a and four corner parts 211b hanging down from the upper surface 211a is fixed to a lower surface of the heating coil unit 200 while covering the infrared sensor module 407, and a heat insulating material 60 with elasticity is stuck outside a bottom surface of the magnetic shielding case 13 covering the bottom part 16d of the resin case 16 of the infrared sensor module 407.

Description

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

  2. Description of the Related Art Conventionally, as a method for detecting the pan temperature of an induction heating cooker, a method including an infrared sensor that detects infrared rays emitted from the bottom of a pan is known.

  In addition, the induction heating cooker contains heat generated from the heating coil and electronic components, cooling air that cools the components that generate heat, and a magnetic field generated from the heating coil. Various ways to protect are devised.

  Therefore, as shown in Patent Document 1, an infrared detection module equipped with an amplifying device that performs ambient temperature correction by the output of a thermopile, which is an infrared detection element (infrared sensor), and the thermistor is composed of a resin provided for the purpose of windproof and heat insulation. A high-frequency current supply for supplying power to the heating coil by covering it with a windshield case (resin case) and covering the infrared detection module with a magnetic shield case (magnetic shield case) made of metal for the purpose of shielding the magnetic field from the heating coil The windproof case and the infrared detection module covered with the magnetic shield case are fixed on a case containing the device, and placed on the top plate through an opening (light guide tube) provided near the heating coil. The thing which measures the temperature of the pot to perform is described (refer FIG. 3, FIG. 5 of the literature 1).

JP 2009-266506 A

  In the induction heating cooker shown in Patent Document 1, an infrared detection module that detects infrared rays radiated from the bottom of the pan is fixed on a case containing a high-frequency current supply device that supplies power to the heating coil, and the vicinity of the heating coil In order to measure the temperature of the pan placed on the top plate through the opening provided in, the heating coil that was pressed against the top plate moves when an unexpected strong impact is applied during transportation. There is a problem that part of infrared rays emitted from the pan is shielded by the heating coil, or infrared rays emitted from the heating coil are incident on the thermopile of the infrared detection module.

  And in order to solve the said subject, when an infrared detection module is fixed to the coil base of a heating coil, the whole infrared detection module is exposed to the cooling air which flows through the inside of a cooling air path.

  In particular, the infrared module used in the induction heating cooker shown in Patent Document 1 uses a thermopile as an infrared detection element.

  The mounting of the thermopile is fixed and electrically connected to the circuit by soldering on the back side of the board by passing the legs (metal pins) that serve as attachment parts connected to the electrodes of the thermopile through the holes made in the board. .

  And the infrared module put in the windproof case is divided by the substrate into the electronic component placement surface side and the back side which is the foot side soldering electronic components such as thermopile, the substantially partitioned back side is The space is very narrow, and the tip of the thermopile foot is very adjacent to the infrared sensor case.

  When an infrared module in which such a windproof case is further covered with a magnetic shield case is mounted on the back side of the heating coil and provided in the cooling air passage, the cooling air flows on the back side of the magnetic shield case and the magnetic Since the shield case efficiently exchanges heat with the cooling air, the temperature change of the cooling air is transmitted through the resin of the windproof case, and the wall surface temperature inside the windproof case changes minutely. And the temperature change is transmitted from the foot soldered to the back side of the board to the inside of the package, and the thermocouple with a small heat capacity connected to the foot changes the output voltage following the minute temperature change, the same A temperature-correcting thermistor housed in a package and connected to the foot similarly has a larger heat capacity than a thermocouple, so that its resistance value changes slowly without following a minute temperature change.

  The thermopile thermistor is built into the thermopile, and is not capable of satisfactorily correcting the temperature under conditions where the temperature changes in a short time as it is used in an induction heating cooker. It is merely a specification for evaluation, and after changing the ambient temperature, it is saturated and maintained for about 10 minutes. Is performance.

  Therefore, when the thermopile thermocouple is used by incorporating it in an induction heating cooker, the output voltage that changes following the minute temperature change is amplified by the amplifying device, so that the temperature of the pan is changing. As a result, there is a problem that the temperature of the pan cannot be measured accurately.

  The present invention has been made to solve the above-mentioned problems. In claim 1, a main body, a top plate on which a pan is placed, and a heating coil provided below the top plate for heating the pan are provided. A heating coil unit, a high-frequency power supply circuit for supplying power to the heating coil, an infrared sensor module that is provided below the heating coil unit and detects the temperature of the pan over the top plate, and the infrared sensor module A control circuit that controls the high-frequency power supply circuit according to the output and supplies predetermined power to the heating coil, and a cooling fan that generates cooling air for cooling the heating coil, the high-frequency power supply circuit, and the infrared sensor module The infrared sensor module generates a voltage according to the amount of received infrared light emitted from the pan, and varies depending on the temperature. A thermopile with a built-in thermistor whose resistance changes, a thermal infrared temperature detection circuit that corrects the generated voltage by a resistance change of the thermistor and amplifies the corrected voltage, and the thermopile and the thermal infrared temperature detection circuit A printed wiring board that is mounted and electrically connected to the thermopile and the thermal infrared temperature detection circuit through a hole through a metal pin of the thermopile and soldered on the back side, and the cooling air is applied to the printed wiring board A resin case that covers the printed wiring board so that it does not directly hit, a metal magnetic shielding case that covers the outside of the resin case so as to prevent the influence of a magnetic field generated from the heating coil on the printed wiring board, and a back surface side of the printed wiring board A heat insulating material is provided on the outer surface of the opposing magnetic shielding case.

  According to a second aspect of the present invention, the heat insulating material is composed of an upper surface and four corners hanging from the upper surface, and is separate from the fixing member that covers the infrared sensor module, forms an air layer inside the heat insulating material, and is elastic. The material is affixed to the magnetic shielding case.

  According to the present invention, in the operation in which the heating conditions change while suppressing the temperature change of the metal pin (foot) of the thermopile, the speed of the temperature drop inside the main body of the heating cooker and the speed of the temperature drop of the thermopile ambient temperature. Therefore, the temperature of the pan as the object to be heated can be accurately measured with the thermopile without being affected by the cooling air inside the main body of the induction heating cooker.

  In addition, since it is made of elastic material, the infrared sensor module is fixed to the heating coil unit, and the bottom of the infrared sensor module has a small dimensional likelihood with the components inside the main body, and the bottom of the infrared sensor module is inside the main body. The shock can be absorbed when contacting the components.

  Moreover, since the heat insulating material is affixed to the magnetic shielding case, it is easy to assemble.

The external appearance perspective view of the induction heating cooking appliance of one Example. The main body top view which removed the top plate of the induction heating cooking appliance. The main body top view which removed the heating coil unit of FIG. The top view of the heating coil unit of the induction heating cooking appliance of one Example. The bottom perspective view of the heating coil unit of the induction heating cooking appliance of one example. Sectional drawing of the infrared sensor group cut | disconnected by the DD cross section of FIG. Sectional drawing of the thermopile cut | disconnected by the EE cross section of FIG. The top view of the thermopile cut | disconnected by CC cross section of FIG. Explanatory drawing of the cooling air path cut | disconnected by the AA cross section of FIG. Explanatory drawing of the cooling air path cut | disconnected by the BB cross section of FIG. The functional block diagram of the temperature detection of the induction heating cooking appliance of one Example, and a heating control system.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  1-3, 1 is a main body of an induction heating cooking device. Reference numeral 2 denotes a top plate made of crystallized glass having high heat resistance, which is horizontally disposed on the upper surface of the main body 1 and on which a pan 501 (FIG. 10) made of a magnetic material such as iron or a non-magnetic material such as aluminum is placed. Is.

  The top plate 2 has an optical characteristic of transmitting infrared light having a wavelength of 4 μm or less and cutting infrared light having a longer wavelength. Reference numerals 3 a to 3 c denote three heating units arranged below the top plate 2, which have a heating coil unit 200 (FIG. 2) that induction-heats the pan 501 placed on the top plate 2.

  Reference numerals 31 a to 31 c denote infrared transmission regions that transmit infrared rays radiated from the bottom of the pan to the lower side of the top plate 2. Here, the number of heating units is three, but the number of heating units may be one or two. Reference numeral 4 denotes an air intake opening that opens upward at the rear portion of the main body 1 and takes cooling air into the main body 1. Reference numeral 5 denotes an exhaust port which opens upward at the rear portion of the main body 1 and discharges exhaust heat that has cooled the inside of the main body 1. In this embodiment, the intake port 4 is disposed on the right side of the rear portion of the main body 1 and the exhaust port 5 is disposed on the left side.

  Reference numeral 6 denotes a grill heating unit provided at the left front portion of the main body 1.

  Reference numerals 7a to 7c denote operation units provided on the upper surface side of the main body 1 for setting and operating the heating units 3a to 3c. Reference numerals 8a to 8c are display units that are provided at the upper part on the front side of the top plate 2 and display the setting states of the operation units 7a to 7c and the energization states of the heating units 3a to 3c.

  One of the ducts 408 communicates with the cooling fan 401 (FIG. 9), and guides cooling air from the other opening 408a to the heating coil unit 200. An exhaust port of a duct 409 (FIG. 9) surrounding a high-frequency power supply circuit 403 to 405 (FIG. 9) to be described later and a part of the duct 408 are connected and exhausted.

  The heating coil unit 200 will be described with reference to FIG. The heating coil 201 is composed of an inner peripheral heating coil 201a and an outer peripheral heating coil 201b provided on the same concentric plane, and an outer end of the inner peripheral heating coil 201a and an inner end of the outer peripheral heating coil 201b. Are electrically connected.

  In this embodiment, the inner peripheral heating coil 201a is provided at a distance of about 30 to 45 mm from the coil center, and the outer peripheral heating coil 201b is provided at a distance of about 55 to 90 mm from the coil center.

  Reference numeral 203 denotes a coil base for holding the heating coil 201, and 202 denotes a gap spacer for providing a gap between the top plate 2 and the heating coil 201.

  Further, the light guide tube 508 is formed integrally with the coil base 203, is provided substantially perpendicular to the top plate 2 (FIG. 10), and detects the thermopile 12 (FIG. 6) provided at a distance of 45 to 55 mm from the coil center. The area is defined, the field of view of the thermopile 12 is narrowed, and the infrared rays emitted from the pan bottom 501a (FIG. 10) are guided to the thermopile 12 described later. Further, infrared rays from the heating coil 201 are prevented from entering the visual field of the thermopile 12.

  In this embodiment, the size of the detection area of the thermopile 12 is about 10 mm in diameter using the light guide tube 508. The upper end of the light guide tube 508 is substantially the same height as the heating coil 201 (FIG. 10). Reference numerals 205 to 208 denote thermistors (contact temperature sensors) for measuring the temperature of the lower surface of the top plate 2.

  5 and 6, reference numeral 407 denotes an infrared sensor module, which is fixed to the lower side of the coil base 203 with a screw 210 via a fixing member 211.

  The fixing member 211 is a resin molded product, and the infrared sensor module 407 is held around the upper surface 211a and the four corners 211b hanging from the four sides of the side surface, and there is no constituent member that covers the bottom surface of the infrared sensor module 407. The upper surface 211a includes a window portion 211c. The four corners 211b prevent wind from entering through the gaps at the corners of the magnetic shielding case 13, which will be described later, and protect the lead wires such as the thermistors 205 to 208 from the end surfaces of the corners of the magnetic shielding case 13. Yes.

  Reference numeral 13 denotes a magnetic shielding case, which becomes the outer surface of the infrared sensor module 407. The magnetic shielding case 13 is composed of a substantially flat top 13a and a box-shaped bottom 13b. The top 13a is provided with a window 13f, a claw 13c with a part of the side bent, and the claw 13c is fitted and fixed to the bottom 13b. Has been.

  The lower portion 13b is provided with fixing portions 13d and 13e. When the screw 210 is passed through the upper portion 13a and the fixing portion 13d and fixed to the heating coil unit 200 via the fixing member 211, the upper portion 13a and the lower portion 13b are brought into close contact with each other and electrically connected. The same applies to the other fixing portion 13e. As a result, when the magnetic shielding case 13 needs to be grounded, the ground wire connected to either the upper 13a or the lower 13b and the upper 13a and the lower 13b are electrically connected.

  A heat insulating material 60 is provided on the bottom surface of the magnetic shielding case 13 that becomes the bottom surface side 407 a of the infrared sensor module 407. The heat insulating material 60 is a urethane packing of about 5 mm and is attached to the bottom surface of the magnetic shielding case 13 by a glued structure.

  The reason why the heat insulating material 60 is separate from the fixing member 211 is that the fixing member 211 of the resin molded product cannot hold the air layer and obtain a high heat insulating effect.

  Further, by making the magnetic shielding case 13 made of non-magnetic aluminum, electromagnetic noise entering the infrared sensor module 407 is reduced.

  Reference numeral 16 denotes a resin case which is covered with the magnetic shielding case 13. The resin case 16 includes a box-shaped lower 16b and a lid-shaped upper 16a. A window portion 14 is provided on the upper 16 a of the resin case 16, and the window material 15 is accommodated and sealed by the window material 15. The resin case 16 includes a thermopile 12 that detects infrared rays, a thermal infrared temperature detection circuit 72 that amplifies the output voltage of the thermopile 12 by correcting errors due to temperature changes of the thermopile 12 itself, and the reflectance of the pan bottom 501a. The printed wiring board 27 provided with the reflectance detection circuit 132 (FIG. 10) to be measured is accommodated. Since the window portion 14 of the resin case 16 is sealed by the window material 15, the cooling air 406 (FIG. 9) is supplied to the thermopile 12, the thermal infrared temperature detection circuit 72, and the reflectance detection circuit 132 inside the infrared sensor module 407. There is no direct hit. That is, with this configuration, the influence of the cooling air 406 on the thermal infrared temperature detection circuit 72 and the reflectance detection circuit 132 is reduced. Further, the resin case 16 is made of a resin having a low thermal conductivity, thereby preventing the temperature inside the infrared sensor module 407 from rapidly changing. That is, with this configuration, the temperature of the thermopile 12, the thermal infrared temperature detection circuit 72, and the reflectance detection circuit 132 is prevented from changing suddenly due to heat transfer.

  Further, the window material 15 has an optical characteristic of cutting infrared rays (4 μm or more) having a high temperature rising effect emitted from the top plate 2, the light guide tube 508, the heating coil 201, etc. that have become hot. , Infrared rays having a high temperature-raising effect are prevented from entering the infrared sensor module 407.

  In the present embodiment, the infrared transmission characteristics of the top plate 2 and the infrared transmission characteristics of the window member 15 are the same.

  With such a configuration, the thermopile 12, the thermal infrared temperature detection circuit 72, and the reflectance detection circuit 132 allow the cooling air and the ambient temperature to change rapidly, the influence of infrared rays having a high heating effect wavelength, electrical noise, and so on. Can be reduced, a high-accuracy signal can be output in a wide temperature range from 150 ° C. to 300 ° C., and the temperature of the pan 501 can be measured accurately.

  7 and 8 show the details of the thermopile 12. FIG. 8 is a plan view of a cross section taken along the line CC in FIG. 7 (the infrared absorption film 43 is omitted so that a thermocouple formed by the polysilicon vapor deposition film 40 and the aluminum vapor deposition film 41 can be seen).

  The thermopile 12 has a large number of thermocouples (thermocouples) connected in cascade (piling), and is incorporated in a metal case 37 made of a metal can 35 such as a nickel-plated steel plate and a metal stem 36. A silicon oxide film 39 is formed on the surface of the silicon substrate 38 having a thickness of about 300 μm to electrically and thermally insulate, and polysilicon and aluminum are sequentially deposited on the surface of the silicon oxide film 39 by the polysilicon deposited film 40 and the aluminum deposited film 41. Create a number of thermocouples and connect them in cascade. An infrared absorption film 43 such as a rubidium oxide film close to a black body is formed at the center of the silicon substrate 38 having a polysilicon / aluminum junction (temperature measuring contact). One end of the polysilicon and aluminum vapor deposition film is a cold junction 44, which is disposed around the silicon substrate 38. The back surface of the silicon substrate 38 is etched to 299 μm leaving the periphery (cold contact portion), and the thickness of the silicon substrate having the temperature measuring contact portion is formed to 1 μm. This is because silicon having good heat conduction is thinned to reduce heat conduction between the temperature measuring contact portion 42 and the cold junction portion 44, and the temperature measuring contact portion 42 and the cold junction portion 44 are thermally insulated.

  The silicon substrate 38 is fixed to the metal stem 36 in the metal case 37 with a bond or the like. At the same time, the NTC thermistor 45 formed on the ceramic is similarly disposed on the metal stem 36. This is for detecting the ambient temperature of the thermocouple in the metal case 37 and correcting the thermoelectromotive force of the thermocouple. Details will be described later.

  In addition, four metal pins 46 that are insulated and sealed are passed through the metal stem 36, and the output of the previous thermocouple and the NTC thermistor 45 are wire-connected to the metal pins.

  A cylindrical metal can 35 is covered and welded to the metal stem 36 in an inert gas. A small-hole window 47 is opened on the upper surface of the metal can 35, and an optical filter 48 (a member that transmits light in a certain wavelength region) is attached thereto from the inside. The silicon substrate 38 is fixed so that the temperature measuring contact portion 42 (below the infrared absorbing film 43) is positioned below the small hole window 47, and the thermocouple is irradiated with the infrared light that has passed through the small hole window 47. The temperature measuring contact 42 (below the infrared absorbing film 43) is heated, and this heating temperature rise is proportional to the infrared energy that has passed, and proportional to the temperature difference between the cold junction 44 of the thermocouple and the temperature measuring contact 42. This voltage is output to the thermocouple output metal pin 46.

  For this reason, when the temperature of the pan rises, the infrared radiation intensity from the pan bottom increases, the amount of infrared energy received by the thermopile 12 increases, and the output signal voltage of the thermopile 12 increases.

  In FIG. 9, 401 is a cooling fan, 402 is a motor that drives the cooling fan 401, and 403 to 405 are high-frequency power supply circuits that supply high-frequency power to the heating coil 201. A cooling air 406 is sucked by a cooling fan 401 and is blown to the infrared sensor module 407, the heating coil unit 200, and the top plate 2.

  The cooling air 406 shown in the present embodiment is a simplified representation of the flow of the cooling air related to this patent. Actually, the high-frequency power supply circuits 403 to 405 are also blown by the duct 409. The heating coil unit 200 is supported by a spring (not shown) so as to be in close contact with the lower surface of the top plate 2. The heating coil unit 200 and the top plate 2 allow the cooling air 406 that cools the heating coil 201 to pass through the gap provided by the gap spacer 202.

  In FIG. 10, the flow of the cooling air 406 around the infrared sensor module 407 will be described. The cooling air 406 flows through the duct 408, the bottom surface side 407 a of the infrared sensor module 407 provided at the lower portion of the heating coil unit 200 becomes the windward, and the cooling air 406 is provided on the heat insulating material 60 provided on the bottom surface side 407 a of the infrared sensor module 407. In this case, it passes through the side surface 407b of the infrared sensor module 407, and the side surface 407b is cooled and raised. Then, from the opening 408a of the duct 408, the heating coil unit 200 above the infrared sensor module 407 passes through the clearance of the heating coil 201 and the inner and outer circumferences of the coil base 203 and flows above the heating coil 201, and the light guide tube 508 and the like. These components are cooled, flow to the lower surface of the top plate 2 disposed above the heating coil unit 200, and are exhausted from the exhaust port 5 to the outside of the main body 1.

  In addition, even when the heating coil unit moves downward due to a sudden impact, the heat insulating material 60 is provided with a resilient urethane packing on the bottom surface side 407a of the infrared sensor module 407 so that it hits the structure portion 408d. To absorb the shock of.

  FIG. 11 is a functional block diagram of the temperature detection and heating control system. In FIG. 11, 501 is a pan that is an object to be heated, 502 is a temperature detection circuit that calculates the temperature of the pan 501 based on the outputs of the infrared sensor module 407 and the thermistors 205 to 208, and 26 is based on the output of the infrared sensor module 407. An emissivity calculation circuit for calculating the emissivity of the pan 501, 503 corrects the temperature calculated by the temperature detection circuit 502 based on the output of the emissivity calculation circuit 26, and sets the high frequency power supply circuit 405 according to the corrected temperature. It is a control circuit that controls and controls the power supplied to the heating coil 201. When automatic cooking is selected by the operation unit 7 shown in FIG. 1, the temperature of the pan 501 is detected and controlled by the infrared sensor module 407, the temperature detection circuit 502, the emissivity calculation circuit 26, and the control circuit 503 described above.

  Next, the operation of this embodiment will be described.

  When the user places the pan 501 on the top plate 2 and operates the operation unit 7c to start heating, the control circuit 503 controls the high frequency power supply circuit 405 to supply predetermined power to the heating coil 201. . When a high frequency current is supplied to the heating coil 201, an induction magnetic field is generated from the heating coil 201, and an eddy current is generated in the pan 501 to be induction heated. By this induction heating, the temperature of the pan 501 rises and the food in the pan 501 is cooked. At the same time, electric power is supplied to the motor 402, the cooling fan 401 rotates and blows the cooling air 406, the high frequency power supply circuits 403 to 405 through the duct 409, the heating coil unit 200 through the duct 408, The infrared sensor module 407 is cooled.

  The cooling air 406 blown from the cooling fan 401 flows through the duct 408 and flows from the bottom of the infrared sensor module 407. Then, the side surface of the infrared sensor module 407 is raised, the window material 15 and the light guide tube 508 are cooled, and the heating coil unit 200 flows from the bottom to the top to cool down, and then strikes the top plate 2 to be dispersed in all directions and heated. The heating coil 201 and the top plate 2 are cooled while passing through the gap between the coil 201 and the top plate 2, and then discharged from the exhaust port 5.

  The temperature of the cooling air 406 was initially the same as the outside air sucked from the air inlet 4, but as the cooking progressed, the temperature of the top plate 2 increased due to the temperature of the pan 501 rising, and the heating coil 201. As the temperature rises and the temperature of the components in the high frequency power supply circuit 405 rises, the temperature gradually rises while repeating the rise and fall in a complicated manner.

  Even when such cooling air 406 hits the infrared sensor module 407, the heat insulating material 60 stuck to the bottom of the magnetic shielding case 13 does not transmit a complicated changing temperature to the back side of the printed wiring board 27 of the resin case 16, The temperature on the back surface side of the printed wiring board 27 in the resin case 16 changes slowly and rises.

  In addition, since the heat insulating material 60 is pasted only on the bottom of the magnetic shielding case 13, the temperature in the resin case 16 of the infrared sensor module 407 also drops after cooking is completed, so that the resin case is reheated. It is possible to reduce the difference between the temperature of the back surface side of the printed wiring board 27 in the inside 16 and the temperature of the cooling air. By reducing the temperature difference, the temperature change in the resin case 16 due to the cooling air 406 can be reduced. I try not to wake it up.

  The temperature on the electronic component placement surface side of the printed wiring board 27 in the resin case 16 is complicatedly changed by the influence of the cooling air 406 because the magnetic shielding case 13 is exposed without covering the heat insulating material on the side surface side.

  According to the induction heating cooker of the present embodiment described above, the temperature drop inside the main body 1 of the induction heating cooker is reduced after cooking while suppressing the temperature change of the metal pin 46 (foot) of the thermopile 12. By making the speed and the speed of the temperature drop of the atmosphere temperature of the thermopile 12 substantially the same, the temperature of the pot 501 that is the object to be heated is not affected by the cooling air 406 inside the main body 1 of the induction heating cooker. 12 can be measured accurately.

  Further, since the material is elastic, the infrared sensor module 407 is fixed to the heating coil unit 200. The bottom of the infrared sensor module 407 has a small dimensional likelihood with the components inside the main body, and the infrared sensor module 407 The impact can be absorbed when the bottom contacts the components inside the body.

  Moreover, since the heat insulating material 60 is affixed on the magnetic-shielding case 13, it is easy to assemble.

DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 12 Thermopile 13 Magnetic-shield case 16 Resin case 16d Bottom part 27 Printed wiring board 45 Thermistor 46 Metal pin 60 Thermal insulation material 72 Thermal type infrared temperature detection circuit 200 Heating coil unit 201 Heating coil 211 Fixing member 211a Upper surface 211b Four corners 401 Cooling fan 403, 404, 405 High frequency power supply circuit 406 Cooling air 407 Infrared sensor module 501 Pan

Claims (2)

  A main body, a top plate on which the pan is placed, a heating coil unit provided below the top plate and provided with a heating coil for heating the pan, a high-frequency power supply circuit for supplying power to the heating coil, and the heating An infrared sensor module that is provided below the coil unit and detects the temperature of the pan through the top plate, and controls the high-frequency power supply circuit according to the output of the infrared sensor module to supply predetermined power to the heating coil A control circuit, a heating fan, a high-frequency power supply circuit, and a cooling fan that generates cooling air for cooling the infrared sensor module, and the infrared sensor module is configured to control the amount of received infrared radiation from the pan. A thermopile with a built-in thermistor that generates a voltage depending on the temperature, and the resistance of the thermistor A thermal infrared temperature detection circuit that corrects the generated voltage by amplification and amplifies the corrected voltage; and the thermopile and the thermal infrared temperature detection circuit, and the thermopile and the thermal infrared temperature detection circuit A printed wiring board in which the metal pin of the thermopile is passed through a hole and soldered on the back side for electrical connection, a resin case that covers the printed wiring board so that the cooling air does not directly hit, and the printed wiring board In order to prevent the influence of the magnetic field generated from the heating coil, a metal magnetic shielding case that covers the outside of the resin case, and a heat insulating material is provided on the outer surface of the magnetic shielding case that faces the back side of the printed wiring board. An induction heating cooker characterized by that.   The heat insulating material is composed of an upper surface and four corners hanging from the upper surface, and is a separate member from the fixing member that covers the infrared sensor module, forms an air layer inside the heat insulating material, and is an elastic material, The induction heating cooker according to claim 1, wherein the induction heating cooker is attached to the magnetic shielding case.

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