JP2010135191A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent fried food cooking from being an unsuccessful result by exactly determining whether the cooking is carried out by a frying pan provided as an attachment. <P>SOLUTION: An induction heating cooker includes a top plate 2, a heating coil 3 mounted under the top plate 2, an infrared sensor 17 detecting infrared rays radiated from a cooking vessel, a temperature sensor 15 mounted in contact with a lower surface of the top plate 2 measuring a temperature of the cooking vessel, an infrared radiation means projecting the rays on a bottom face of the cooking vessel and an infrared receiving means receiving the reflected rays from the bottom face of the cooking vessel, a reflectance measuring means 19 for measuring the reflectance of the cooking vessel by an output of the infrared receiving means, a control means 118 controlling power supplied to the heating coil 3 based on an output of the temperature sensor 15, and a menu-setting means 71 for setting a temperature of the cooking vessel. In the case of the fried food cooking carried out by the menu-setting means 71, the output from the reflectance measuring means is used to determine whether the vessel 30 is the attachment of the induction heating cooker or not. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating cooker including temperature detection means for detecting the temperature of a pan placed on a top plate via the top plate.

  This type of conventional induction heating cooker has a fried food menu in the cooking menu, and when the “fried food” key is selected in the operation unit, the temperature of the cooking pan placed on the top plate is detected via the top plate. The temperature of the oil in the pan is controlled from the output of the temperature sensor.

  There are many types of pans that can be used in the induction heating cooker. Generally, there are iron-based pans with good thermal conductivity, and SUS-based pans, which are magnetic materials that are less heat conductive than iron-based pans. in use.

  However, some iron pans differ in thickness, sledge, size, and shape of the pan, and SUS pans have the same differences as iron pans, as well as those with poor thermal conductivity and pan bottoms. However, if such a pan is used, the temperature at the bottom of the pan cannot be detected accurately, and the oil temperature may not be controlled at an appropriate temperature.

  Therefore, as a cooking container for fried foods, a pan that manages the material, the shape of the pan bottom, the thickness of the pan, etc. is provided as an accessory to the induction heating cooker, and a control program for fried food menus in combination with this pan Is built into the control circuit so that fried food can be cooked deliciously without failure.

  Then, when cooking fried food, a predetermined power is supplied to the heating coil, and the output of the input power monitor circuit at this time, the operating frequency of the inverter means, and the temperature of the pan placed on the top plate are passed through the top plate. From the output of the temperature sensor (thermistor) to be detected, determine whether the cooking container is an accessory pan or not, and if a pan other than the accessory pan is being used, notify that and stop the heating operation, The failure of cooking due to the use of pans other than accessories is prevented (for example, see Patent Document 1).

JP 2003-77640 A

  However, in the above prior art, when fried food cooking, in order to detect whether or not the accessory pan is used as a cooking container, predetermined power is supplied to the heating coil at the start of fried food cooking. Because the input power and the operating frequency of the inverter means that supplies power to the heating coil and the output of the thermistor that detects the temperature of the pan are detected, the pan is heated for a while after fried food cooking is started. Otherwise, it cannot be determined whether it is an accessory pan, and there is a disadvantage that it takes time and is not easy to use.

  In addition, cooking containers of similar materials and sizes may be misjudged as accessory pans. For this reason, if the criteria for pans described above are stricter, accessories may be used depending on how the pans are placed or the pans are deformed. Even if you use a hot pot, it may be misjudged if it is not an accessory pan, and it will be inconvenient.

  The present invention was made to solve the above-described conventional problems, and can accurately determine whether or not fried food cooking is performed in an accessory pan, and prevents fried food cooking failures. It is.

  The present invention has been made to solve the above-described problems. In claim 1, a top plate on which a cooking container is placed, a heating coil provided below the top plate, and a temperature of the cooking container. A temperature sensor for detecting the temperature, infrared light emitting means for projecting on the bottom surface of the cooking container, infrared light receiving means for receiving reflected light from the bottom surface of the cooking container, and the reflectance of the cooking container from the output of the infrared light receiving means. A reflectance measuring means for measuring, a control means for controlling the electric power supplied to the heating coil based on the output of the temperature sensor, and a menu setting means for setting the temperature of the cooking container. When fried food cooking is selected, it is determined from the output of the reflectance measuring means whether the cooking container is a cooking pan attached to the induction heating cooker for fried food cooking. It is.

  In claim 2, when it is determined that the cooking pan is different from the cooking pan for frying cooking attached to the induction heating cooker, the operation of frying cooking is stopped and a notification is given.

  The induction heating cooker of the present invention is configured as described above, thereby accurately determining whether or not fried food cooking is performed in a cooking pan attached to the induction heating cooker, and fried food using a pan other than the accessory. Can prevent cooking failure.

  Moreover, when fried food cooking is performed in a pan other than the accessory, the fried food cooking operation is stopped and notified, so that it is safe and easy to use.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is an external perspective view of an induction heating cooker showing an embodiment of the present invention. In FIG. 1, the top plate 2 is horizontally arrange | positioned on the upper surface of the main body 1 of the induction heating cooking appliance.

  The top plate 2 is made of crystallized glass with a high heat resistance and has a thickness of about 4 mm, and a cooking container such as a pan 30 made of a magnetic material such as iron or a non-magnetic material such as aluminum is placed on the top plate 2.

  Below the top plate 2, the annular heating coils 3 are arranged on the left and right sides of the upper part in the main body 1 and the central rear part, respectively, and the induction heating is performed on the pan 30 and the like placed on the top plate 2.

  Upper surface operation portions 7a, 7b, 7c corresponding to the respective heating coils 3 are provided on the upper surface on the front surface side of the top plate 2, and the energization state of the heating coils 3 is set and operated. Corresponding to the upper surface operation parts 7a, 7b, 7c, upper surface display parts 8a, 8b, 8c are provided in the vicinity of the upper surface operation parts 7a, 7b, 7c, and the energization state of each heating coil 3 is determined. indicate.

  The upper surface operation unit 7a inputs the heating power of the heating coil 3 on the right side of the main body 1, the upper surface operation unit 7b inputs the heating power of the heating coil 3 at the center rear of the main body 1, and the upper surface operation unit 7c is on the left side of the main body 1. The heating power of the heating coil 3 is input.

  An intake port 4 opened upward is provided on the right side of the rear portion of the main body 1, and a cooling air sucked from the intake port 4 by a fan (not shown) provided in the main body 1 is entered into the main body 1. It cools by flowing in the control board (not shown), the heating coil 3, etc. which were provided.

  An exhaust port 5 for exhausting the cooling air that has cooled the inside of the main body 1 is provided on the rear left side of the main body 1.

  A grill heating means 6 for grilling fish, pizza or the like is provided on the left side of the front surface of the main body 1, and the grill heating means 6 has a box shape with an open front, and a sheathed heater or the like in an internal cooking chamber. The thermistor for detecting the temperature of the heating element and the internal temperature are provided, and the front surface is closed by a grill door 6b to which a handle 6a is attached.

  The grill door 6b has a saucer attached to the back side of the grill door 6b. The grill door 6b is housed in the cooking chamber so that it can be inserted and removed freely from the front opening, and cooked by placing ingredients such as fish and pizza on the grill net placed on the saucer. To do.

  A main power switch 9 for supplying power to the main body 1 and a front operation unit 10 for inputting cooking conditions for the grill heating means 6 and the like are provided on the right front portion of the main body 1.

  The front operation unit 10 has a so-called kangaroo pocket shape in which the upper part of the operation panel 11 is tilted to the front side around a rotation axis provided below and the operation keys 12 are exposed upward.

  FIG. 2 is a top view of the induction heating cooker excluding the top plate 2, and FIG. 3 is a block diagram showing a configuration mainly including the left and right heating coils 3 of the induction heating cooker.

  The heating coils 3 arranged at the left and right and the central rear part are each composed of an annular inner heating coil 3a and an annular outer heating coil 3c arranged with an annular gap 3b on the outside thereof.

  The reason why the gap 3b is provided in the heating coil 3 is to disperse the magnetic flux generated by the inner heating coil 3a and the outer heating coil 3c and to make the temperature of the pan 30 uniform.

  In addition, although each heating coil 3 was set as the structure which provides the clearance gap 3b, it is not limited to this in particular. For example, the structure which is set as the heating coil 3 without the gap | interval 3b which wound the inner side heating coil 3a and the outer side heating coil 3c without the gap may be sufficient.

  As shown in FIG. 3, the heating coil 3 is installed on the coil base 13. A gap spacer 14 is provided at appropriate intervals from the outer periphery of the coil base 13 toward the center by a support member 16 attached to the outer peripheral edge of the coil base 13, and the coil base 13 includes a plurality of coil bases 13. By being biased in the direction of the top plate 2 by a spring (not shown), the heating coil 3 is substantially parallel to the top plate 2, and the pot 30 and the heating coil 3 placed on the top plate 2 are The gap is kept constant.

  The heating coil 3 employs a litz wire to suppress the skin effect, and a voltage of several hundred volts is applied at a high frequency of several tens kHz by the inverter means 100 described later, and a high frequency magnetic field is applied to the pan 30. An eddy current is generated in the pan 30 and the pan 30 is heated by self-heating.

  Near the center of the heating coil 3 disposed on the left and right, an inner temperature sensor 15a among a plurality of temperature sensors 15 formed of a thermistor is provided in close contact with the lower surface of the top plate 2, and the heating coil 3, the temperature of the pan 30 placed above 3 is detected via the top plate 2.

  Similarly, in the gap 3b of the heating coil 3, outer temperature sensors 15b, 15c, 15d composed of thermistors are equidistant from the center of the heating coil 3 and at equal intervals of 120 degrees. The temperature of the pan 30 placed above the heating coil 3 is detected by being provided via (not shown) and in close contact with the lower surface of the top plate 2.

  The outer temperature sensors 15b, 15c, and 15d are configured to be provided in the gap 3b of the heating coil 3, but are not particularly limited thereto. For example, the structure provided in the outer periphery vicinity of the outer periphery of the outer side heating coil 3c or the structure used as the heating coil 3 without the clearance gap 3b which wound the inner side heating coil 3a and the outer side heating coil 3c without the gap may be sufficient.

  Further, the outer temperature sensors 15b, 15c, and 15d are not limited to three, and may be one or two, or three or more.

  Below the center of the heating coil 3 disposed on the left and right, an infrared sensor 17 that receives infrared rays radiated from the bottom surface of the pan 30 through the top plate 2 and detects the temperature from the received infrared energy. Is provided.

  The infrared sensor 17 is a sensor using a thermal detection element, and its light receiving surface 17a is located at a position near the center of the inner heating coil 3a and is about 35 mm away from the lower surface of the top plate 2 below the heating coil 3. It is provided at the position.

  Further, the light receiving surface 17a is provided with a lens, a light guide tube, and the like (not shown) that limit the viewing angle of infrared rays to be detected. As shown in FIG. The viewing angle is detected by the detection spot 17b.

  A reflective photo interrupter 18 is provided at a position away from the lower surface of the top plate 2 in the gap 3b between the heating coils 3 arranged on the left and right.

  FIG. 4 is a diagram for explaining the reflective photointerrupter 18. As shown in the drawing, the reflection type photointerrupter 18 has an infrared LED 18a as an infrared light emitting means and an infrared phototransistor 18b as an infrared light receiving means arranged on the same plastic member and molded 18c.

  A plastic lens is formed on the light emitting surface of the infrared LED 18a, and irradiates a thin beam of infrared light upward.

  A visible light blocking plastic lens is formed on the light receiving surface of the infrared phototransistor 18b, and the reflected infrared light at the object (pan bottom) of the irradiated infrared light is received with a narrow viewing angle, and the amount of received light. A current proportional to is output.

  From the output of the infrared phototransistor 18b of the reflection type photo interrupter 18, the reflectance measurement means 19 measures the reflectance of the bottom surface of the pan 30 placed on the top plate 2.

  FIG. 5 is a diagram illustrating the upper surface operation unit 7a and the upper surface display unit 8a.

  Since the contents of the upper surface operation unit 7c and the upper surface display unit 8c are the same as the contents of the upper surface operation unit 7a and the upper surface display unit 8a, description thereof is omitted.

  The upper surface display unit 8a is divided into a display unit 81a and a display unit 81b, and the display unit 81a displays the thermal power input by the thermal power setting means 72, the cooking menu input by the menu setting means 71, and the like.

  The display unit 81b informs the user of the timing of loading the ingredients when the pan 30 is preheated and the temperature of the pan 30 reaches an appropriate temperature in the “fried food” or “steak” menu set by the menu setting means 71. “Preheating” and “Suitable temperature” can be displayed.

  The thermal power that can be set by the thermal power setting means 72 is divided into four stages, a “hot fire” key 72a, a “low fire” key 72b, a “medium fire” key 72c, and a “high fire” key 72d, and the necessary thermal power can be input by one operation. Keys are provided individually according to the thermal power so that you can.

  The arrow adjusting means 73 is used to finely adjust the medium heat up and down after setting the medium power with the heat power that cannot be input by the heat power setting means 72, for example, with the "medium heat" key 72c.

  The menu setting means 71 is for setting “cooking rice”, “fried food”, “boiled water”, “stir fry”, “steak”, etc. for automatic cooking. By pressing the menu setting means 71, the display unit 81a is set. A menu is displayed, and the menu is switched each time the menu setting means 71 is pressed. This selects the menu to be used.

  When “fried food” is selected by the menu setting means 71, it is necessary to set the oil temperature next. In this case, the arrow adjusting means 73 can be operated to set six stages of temperatures from 150 ° C. to 200 ° C. For example, when the fried food is set by the menu setting means 71 and then the oil temperature is set to 180 ° C. by the arrow adjusting means 73, the display unit 81a displays the number “180” and the letters “fried food” as shown in FIG. Is displayed.

  Reference numeral 74 denotes a cut / start key for starting or stopping cooking.

  FIG. 6 is a block diagram of the inverter means 100. The heating control of the pot 30 by the left and right heating coils 3 will be described with reference to the block diagrams of FIGS.

  Note that the control of the grill heating unit 6 and the control of the heating coil 3 at the center rear of the main body 1 are not directly related to the present invention, and thus the description thereof is omitted.

  The control means 118 inputs the output of the menu setting means 71 and the heating power setting means 72 of the upper surface operation section 7a, the output of the inner temperature sensor 15a provided in the vicinity of the heating coil 3, and the outputs of the outer temperature sensors 15b, 15c and 15d. is doing.

  The reflectance measuring means 19 measures the reflectance of the bottom surface of the pan 30 placed on the top plate 2 from the output of the reflective photo interrupter 18 and inputs it to the control means 118.

  The control means 118 measures the reflectance of the cooking pan 30 attached to the induction heating cooker in advance and stores it as a predetermined value. The reflectance of the predetermined value and the reflection measured by the reflectance measuring means 19 are stored. Compare rates.

  Further, the control means 118 controls the inverter means 100 according to the set contents of the upper surface operation unit 7a, the detected temperatures of the temperature sensors 15a, 15b, 15c, and 15d and the detected temperature of the infrared sensor 17, and the heating coil 3 is controlled. The pan 30 is heated and controlled by controlling the flowing high-frequency current.

  The reason for providing a plurality of temperature sensors 15a, 15b, 15c, and 15d is to prevent the temperature detection accuracy from being lowered due to deformation of the bottom of the pan 30 to detect the temperature of the pan 30. A value obtained by detecting the highest temperature detected by the temperature sensors 15a, 15b, 15c, and 15d is used as the determination temperature.

  As shown in FIG. 6, the inverter unit 100 is configured such that an AC power source 117 is converted into a DC voltage by the rectifying unit 102 and connected to a switching unit configured by a series body of switching elements 103 and 105. Diodes 104 and 106 are connected in antiparallel to the switching elements 103 and 105, respectively, and a resonance circuit unit composed of the heating coil 3 and the resonance capacitor 107 is connected between the connection point of the switching elements 103 and 105 and the reference point of the DC voltage. To do. Further, snubber capacitors 108 and 109 are connected to the switching elements 103 and 105, respectively.

  By switching on and off the switching elements 103 and 105 exclusively at a high frequency, a high-frequency resonance current is supplied to a resonance circuit unit composed of the heating coil 3 and the resonance capacitor 107, and a load disposed in the vicinity of the heating coil 3 is heated.

  The control unit 110 inputs a target power level instruction to be applied to the load from the control unit 118, and controls the switching units 103 and 105 so that the output power of the inverter unit 100 becomes a target value.

  The input current conversion unit 112 converts the output signal of the detection unit 111 that detects the current input from the AC power source 117 to an appropriate level and outputs the converted signal to the control unit 110.

  The input voltage detection means 113 detects the voltage of the AC power supply 117, converts it to an appropriate level, and outputs it to the control unit 110.

  The inverter current detection means 115 converts the output signal of the detection means 114 that detects the current flowing through the resonance circuit section into an appropriate level and outputs it to the control section 110.

  The control unit 110 inputs these signals, calculates inverter power that is input to the load, determines the state of the load, suitability for heating, etc., and performs on / off control exclusively for the switching elements 103 and 105. A signal is output and converted to an appropriate drive level for the switching elements 103 and 105 by the level converter 116 to drive the switching elements 103 and 105.

  The control unit 110 outputs these states to the control unit 118.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement of fried food cooking is demonstrated with the flowchart of FIG.

  The case where the user cooks the deep-fried food using the heating coil 3 on the right side of the main body 1 will be described. First, the main power switch 9 is turned on to turn on the power, and the cooking pot 30 as an accessory used when cooking the deep-fried food is used. Add oil, place it in the center of the heating coil 3 on the right side of the main body 1, and operate the menu setting means 71 of the upper surface operation unit 7a while viewing the display unit 81a to display “fried food” on the display unit 81a. To set the oil temperature. And set temperature is set to 180 degreeC and "180" is displayed on the display part 81a.

  In addition, the cooking pan 30 of the above-mentioned accessory is one that manages the material (iron, magnetic stainless steel), the shape of the pan bottom, the thickness of the pan, etc. so that fried food cooking can be performed without failure. As a set, it is used only for cooking fried foods, and has a black paint around it.

  Next, the temperature control is started by operating the off / start key 74.

  When temperature control is started, the reflectance of the cooking pot 30 is measured by the reflectance measuring means 19 from the output of the reflective photointerrupter 18 in S01, and the process proceeds to S02.

  The control means 118 stores in advance the reflectance of the accessory cooking pan 30 as a predetermined value. In S02, the reflectances of the two are compared, and if the reflectance is within the predetermined value, the accessory is stored. It determines with the cooking pan 30 being used, and transfers to S03.

  On the other hand, if the reflectance of the cooking pot 30 is other than the predetermined value, it is determined that the accessory cooking pot 30 is not used, the temperature control of the frying cooking is finished, and the operation is stopped. And it alert | reports to a user with a display or a sound.

  Thereafter, when it is confirmed that the accessory cooking pan 30 is used, the control means 118 controls the cooking pan 30 to 180 ° C. by the heating coil 3 on the right side in the normal fried food mode. When cooking is performed and cooking of the deep-fried food is finished, the main power switch 9 is turned off.

  In addition, about this normal deep-fried food and other cooking, since it is not especially related to a present Example, description is abbreviate | omitted.

  As described above, according to this embodiment, when fried food cooking is selected by the menu setting means 71, oil is put into the attached cooking pan 30 and placed on the top plate 2 with the heating coil 3, and cut off. When temperature control is started by operating the start key 74, the reflectance of the cooking pot 30 is measured by the reflectance measuring means 19 from the output of the reflective photo interrupter 18, and the accessory cooking pot 30 is preliminarily measured by the control means 118. Is compared with the reflectance stored as a predetermined value, and if the reflectance is within the predetermined value, it is determined that the accessory cooking pot 30 is used, and if the reflectance is other than the predetermined value, it is included. It is determined that the cooking pan 30 of the product is not used, and the temperature control of the frying cooking is finished and the operation is stopped. Therefore, it is determined whether or not the cooking pan 30 is an accessory before the oil temperature of the cooking pan 30 rises. It is possible, As of years, it is not possible to determine whether the pot or not accessories and not heated for a while cooking pot from the start of the deep-fried cooking, it is possible to overcome the drawbacks of poor usability takes time.

  Further, since the reflectance of the cooking pot 30 as an accessory is stored in the control means 118 in advance as a predetermined value, cooking containers of similar materials and sizes can be obtained by appropriately setting the reflectance value. It will no longer be misjudged as an accessory pan, and even if you use an accessory pan due to how to place the pan or deformation of the pan, it will not be misjudged as an accessory pan, It is easy to use.

It is an external appearance perspective view of the induction heating cooking appliance which shows one Example of this invention. It is the top view except the top plate of the induction heating cooking appliance similarly. It is a block diagram which shows the structure which mainly made the heating coil of the left and right of the induction heating cooking appliance similarly. It is a figure explaining a reflection type photo interrupter. It is a figure explaining the upper surface operation part and upper surface display part of this invention. It is a block diagram of the inverter means of this invention. It is a flowchart explaining operation | movement of the induction heating cooking appliance of this invention.

Explanation of symbols

2 Top plate 3 Heating coil 15 Temperature sensor 17 Infrared sensor 18a Infrared LED
18b Infrared phototransistor 19 Reflectivity measuring means 71 Menu setting means 118 Control means

Claims (2)

  A top plate on which the cooking container is placed, a heating coil provided below the top plate, a temperature sensor for detecting the temperature of the cooking container, infrared light emitting means for projecting on the bottom surface of the cooking container, and the cooking Infrared light receiving means for receiving reflected light from the bottom of the container, reflectance measuring means for measuring the reflectance of the cooking container from the output of the infrared light receiving means, and supplying to the heating coil based on the output of the temperature sensor Control means for controlling electric power and menu setting means for setting the temperature of the cooking container, and when the fried food cooking by the menu setting means is selected, the cooking container cooks the fried food from the output of the reflectance measuring means. An induction heating cooker characterized by determining whether or not it is a cooking pan attached to an induction heating cooker.   The induction heating cooker according to claim 1, wherein when the cooking pan is determined to be different from the cooking pan for frying cooking attached to the induction heating cooking device, the operation of frying cooking is stopped and a notification is made. An induction heating cooker characterized by that.

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