JP2011228030A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooker which is maintained at a low temperature suitable for cooking by using an infrared sensor.SOLUTION: An induction heating cooker includes a heating coil 3, an inverter circuit 19, an infrared sensor 17, a temperature and fire power adjustment means 73 for setting a temperature, a cooker 30 and a control means 18 for switching a high-frequency current which is output from the inverter circuit 19 into a predetermined high fire power and a predetermined low fire power so as to maintain the cooker 30 at the set temperature. The control means 18 includes a timer time storage means 94 for storing the time required to maintain the predetermined low fire power and a timer means 93 for measuring the time required to maintain the predetermined low fire power. In order to maintain the cooker 30 at the set temperature on average, the control means 18 switches output from the inverter circuit 19 into the predetermined low fire power when the infrared sensor 17 detects a temperature equivalent to or over the set temperature and starts operation of the timer means 93 to measure the time required to maintain the predetermined low fire power when the infrared sensor 17 detects a temperature equivalent to or over the set temperature, and then switches the output from the inverter circuit 19 into the predetermined high fire power after the time required to maintain the predetermined low fire power has passed.

Description

  The present invention relates to an induction heating cooker that selects and cooks a menu.

  As a conventional induction heating cooker, the temperature of the pan placed on the top plate is detected by a thermistor provided in close contact with the bottom surface of the top plate, and the heating output of the heating coil that heats the pan according to the output of the thermistor is detected. There is something to control and cook. The thermistor for detecting the temperature of the pan has a problem that the temperature response speed is slow because the temperature of the thermistor does not match the temperature of the pan because the top plate is interposed between the thermistor and the pan.

  Therefore, in Patent Document 1, instead of the thermistor, the temperature of the pan is directly captured using an infrared sensor, a menu is selected in advance, and heating is started, so that the temperature becomes suitable for charging the food. Disclosed is an induction heating cooker having an automatic cooking menu having a function of notifying that.

JP 2010-33981 A

  Since the temperature that can be detected by the infrared sensor is in the temperature range of about 150 ° C. to 250 ° C., the automatic cooking of Patent Document 1 using the infrared sensor mainly corresponds to automatic cooking at a temperature of 200 ° C. or higher. It was.

  Therefore, when cooking at a cooking temperature of 140 to 160 ° C. (eg fried eggs), the infrared radiation emitted from the pan cannot be detected sufficiently by the infrared sensor, automatic cooking is not possible. There was a problem of not becoming.

  The present invention has been made to solve the above-described problems. In claim 1, the top plate is provided on the upper surface of the main body, and the top plate is provided below the top plate by supplying a high-frequency current. A heating coil that heats the pan placed on the inverter, an inverter circuit that supplies high-frequency current to the heating coil, an infrared sensor that detects the temperature by infrared rays emitted from the pan through the top plate, and the temperature of the pan And a control means for switching the high-frequency current output from the inverter circuit to a predetermined high heating power and a predetermined low heating power in order to maintain the temperature of the pan at the set temperature. The control means includes a timer time storage means for storing a time for maintaining the predetermined low thermal power, and a timer for measuring the time for maintaining the predetermined low thermal power. In order to maintain the temperature of the pan at a set temperature on average, when the infrared sensor detects a temperature equal to or higher than a predetermined temperature, the output of the inverter circuit is switched to a predetermined low heating power, and the predetermined low heating power is set. After the switching, the timer means is operated, and after measuring the time for maintaining the predetermined low heating power, the output of the inverter circuit is switched to the predetermined high heating power.

  Further, in claim 2, the time for maintaining the predetermined low heating power stored in the timer time storage means is the number of times that the number of times of switching to the predetermined low heating power is the third time from the second time except the first time, and the fourth time from the third time. The longer it is, the longer it is.

  According to a third aspect of the present invention, the control means outputs the output of the inverter circuit when the detected temperature of the infrared sensor detects the set temperature or higher when the set temperature set by the temperature / thermal power adjusting means is the threshold temperature or higher. The temperature is set to a predetermined low heating power, and when the detected temperature of the infrared sensor is equal to or lower than the setting temperature, the output of the inverter circuit is set to a predetermined high heating power and the temperature of the pan is maintained at the set temperature.

  According to the present invention, since the temperature of the pan can be maintained in a low temperature range of 140 to 160 ° C. suitable for cooking by using an infrared sensor, automatic cooking can be applied to fried eggs that are extremely difficult to cook. It became so.

It is an external appearance perspective view of the induction heating cooking appliance which shows the Example of this invention. Similarly, it is the perspective view except the top plate of the induction heating cooking appliance. Similarly, it is the principal part sectional drawing and control block diagram of the heating coil arrange | positioned at the right side of the induction heating cooking appliance. Similarly, it is an enlarged view of an upper surface operation part and an upper surface display part. Similarly, it is explanatory drawing of the operation | movement which performs the temperature control of the control means 18. FIG. Similarly, it is a flowchart figure which shows the temperature adjustment operation | movement of the suitable temperature cooking menu of an induction heating cooking appliance. Similarly, it is a time chart figure of the temperature adjustment operation by the temperature adjustment operation of the appropriate temperature cooking menu of the induction heating cooker. Similarly, it is a flowchart figure which shows the switching heating operation | movement of the suitable temperature cooking menu of an induction heating cooking appliance. Similarly, it is a time chart diagram of the temperature adjustment operation by the switching heating operation of the appropriate temperature cooking menu of the induction heating cooker.

  An embodiment of the present invention will be described below with reference to FIGS. Note that the present embodiment is not limited to the built-in type that fits into the system kitchen, but may be a stationary heating cooker that is placed in the kitchen.

  1 and 2, a top plate 2 is horizontally disposed on the upper surface of the main body 1 of the induction heating cooker. 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, annular heating coils 3 are arranged on the left and right and center rear in the upper part of the main body 1, respectively, and induction heating 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 and the like of the heating coil 3 on the right side of the main body 1, the upper surface operation unit 7b inputs the heating power and the like of the heating coil 3 at the center rear of the main body 1, and the upper surface operation unit 7c The heating power of the 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 cooling air sucked from the intake port 4 by the fan (not shown) provided in the main body 1 is provided in the main body 1. It is cooled by flowing it through a control board (not shown), a heating coil 3 or the like provided on the board. 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. The grill heating means 6 has a box shape with an open front, a heating element such as a sheathed heater and a thermistor for detecting the internal temperature are provided in the internal cooking cabinet, and a handle 6a is attached to the front. The tray is closed by the grill door 6b, and a tray is accommodated therein.

  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.

  As shown in FIG. 2, the heating coils 3 arranged on the left and right and the central rear part are respectively an annular inner heating coil 3a and an annular outer heating coil 3c arranged with an annular gap 3b on the outside thereof. It consists of 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 a coil base 13, and the coil base 13 is biased toward the top plate 2 by a plurality of springs (not shown), and the heating coil 3 is 2 is configured so as to be substantially parallel to 2. The heating coil 3 employs a litz wire to suppress the skin effect, and a high frequency current of several tens of kHz and several hundreds V is supplied from an inverter circuit 19 described later, and a high frequency magnetic field is applied to the pan 30. Then, an eddy current is generated in the pan 30, and the pan 30 is heated by self-heating. The heating coil 3 disposed on the left side and the heating coil 3 disposed on the central rear part have the same configuration.

  In the vicinity of the center of the inner heating coil 3a, an inner temperature sensor 15a of a temperature sensor constituted by a thermistor is attached in close contact with the lower surface of the top plate 2, and the pan 30 placed above the heating coil 3 is attached. The temperature is measured via the top plate 2. Further, in the gap 3b of the heating coil 3, outer temperature sensors 15b, 15c, and 15d of a thermistor constituted by a thermistor at an equal distance of about 120 degrees at an equal distance from the center of the heating coil 3 are used as a buffer material. (Not shown). The protrusions 16 provided on the outer peripheral edge of the coil base 13 are for maintaining a constant gap between the pan 30 placed on the top plate 2 and the heating coil 3. The distance is provided. The outer temperature sensors 15b, 15c, and 15d attached to the support member 14 are in close contact with the lower surface of the top plate 2 because the coil base 13 is biased by a spring in the direction of the top plate 2. The heating coil 3 disposed on the left side has a similar configuration.

  The outer temperature sensors 15b, 15c, and 15d are provided in the gap 3b of the heating coil 3, but are not particularly limited thereto. For example, a configuration may be provided in the vicinity of the outer periphery of the outer heating coil 3c, or in the vicinity of the outer periphery of the configuration of the heating coil 3 having no gap 3b in which the inner heating coil 3a and the outer heating coil 3c are wound without a gap. Further, the outer temperature sensors 15b, 15c, 15d are not limited to three, but may be one, two, or three or more.

  Below the gap 3b of the heating coil 3, an infrared sensor 17 is provided for receiving infrared light emitted from the bottom surface of the pan 30 through the top plate 2 and measuring the temperature from the received infrared energy. . The infrared sensor 17 is a sensor using a thermal detection element, and its light receiving surface 17a is located at a position of the gap 3b of the heating coil 3 at a position about 35 mm away from the lower surface of the top plate 2 below the heating coil 3. Is provided. Although not shown, the light receiving surface 17a is provided with a lens, a filter, a light guide tube, and the like that limit the viewing angle of infrared rays to be measured. As shown in FIG. The viewing angle is detected by the temperature detection spot 17b. The infrared sensor 17 has a characteristic that when the temperature of the pan 30 is about 150 ° C. or less, the infrared energy radiated from the pan 30 cannot obtain a sufficient output.

  Next, heating control of the pan 30 will be briefly described with reference to FIG. 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 are omitted in FIG. In FIG. 3, menu setting means 71 for inputting a cooking menu, temperature / heating power adjusting means 73 for setting a set temperature when the cooking menu is set, and heating power for heating the pan 30 are set in the upper surface operation unit 7 a. A heating power setting means 72 for performing cooking and a cutting / starting key 74 for performing cooking cutting / starting are provided. The operation information is input to the control means 18. The upper surface display unit 8a displays the input information of the upper surface operation unit 7a, the progress of cooking, and the like as display signals by the control means 18.

  The temperature detection signal of each temperature sensor of the inner temperature sensor 15a and the outer temperature sensors 15b, 15c and 15d provided in the heating coil 3 and the infrared sensor 17 provided below the heating coil 3 is input to the control means 18. The control means 18 controls the inverter circuit 19 according to the temperature detected by each temperature sensor, controls the high-frequency current flowing through the heating coil 3, and controls the heating of the pan 30. Further, the control means 18 controls the inverter circuit 19 based on the information set by the menu setting means 71, the thermal power setting means 72, and the temperature / thermal power adjustment means 73, thereby controlling the high-frequency current flowing through the heating coil 3 to control the pan. 30 is heated and controlled.

  The pan state determination means 20 receives the output signal of the infrared sensor 17 provided in the heating coil 3, determines from the detected temperature rise value whether or not the pot 30 being heated is suitable for heating, and the control means 18. To enter. In addition, although the inverter circuit 19 and the pan state determination means 20 are provided with two corresponding to the right and left heating coils 3, the control means 18 comprises the whole.

  Although the detailed operation of the pan state determination means 20 will not be described, the heating coil specific to the cooking menu is controlled in advance by experiments, and the heating coil is used for the state of the pan 30, the material of the bottom of the pan 30 and the difference in thickness. The temperature rise value of the infrared sensor 17 provided in 3 is measured, and the correlation between the temperature rise value data and the state of the problematic pan 30 when the heating control specific to the cooking menu is performed is determined as data. As a reference, the pan state determination means 20 determines whether or not the pot 30 being heated is suitable for heating.

  The upper surface operation unit 7a and the upper surface display unit 8a will be described with reference to FIG. 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 portion 8a is divided into a display 81a and a display 81b. The display 81a has the temperature / temperature when the thermal power input by the thermal power setting means 72, the cooking menu input by the menu setting means 71, and the cooking menu are set. A set temperature or the like input by the thermal power adjusting means 73 is displayed. In addition, the display 81b displays a process of heating the pan temperature to the set temperature when the menu for proper temperature cooking, which is one of automatic cooking, is selected, and “when preheating” is displayed, and when the pan temperature reaches the set temperature. The “appropriate temperature” that is displayed to inform the user of the timing of loading the ingredients is 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 in one operation. In this way, keys are provided individually according to the thermal power. The standard of the thermal power to be set is a maximum of 12 stages of thermal power, and the relationship between each thermal power and power consumption is equivalent to 100W for "1" stage, 200W for "2" stage, and 300W for "3" stage. “4” stage is 400 W, “5” stage is 500 W, “6” stage is 800 W, “7” stage is 1.1 kW, “8” stage is 1.4 kW, “9” stage is 1.6 kW, “ The “10” stage is 2 kW, the “11” stage is 2.5 kW, and the “12” stage is 3 kW.

  As shown to Fig.4 (a), the display of the display 81a is a number which shows the standard of a thermal power. The relationship between the 12-stage number representing the thermal power and the 4-stage thermal power that can be set by the thermal power setting means 72 is “1” for “slow fire”, “2”, “3”, “4”, “5” for “low fire”. “Medium fire” is “6”, “7”, “8”, and “High fire” is “9”, “10”, “11”, “12”.

  When inputting a thermal power that cannot be input by the thermal power setting means 72, for example, a thermal power "9", the temperature / thermal power adjusting means 73 first sets the thermal power to "7" with the "medium fire" key 72c, and then the temperature / thermal power When the adjustment UP key 73b is pressed twice, the number indicating the heating power displayed on the display 81a is changed from "7" to "8", and from "8" to "9", and the heating power is changed to "9". It shows that. Incidentally, when the temperature / heating power adjustment DOWN key 73a is pressed next, the heating power can be lowered from “9” to “8”.

  The menu setting means 71 is for setting “cooking rice”, “fried food”, “boiled water”, “boiled” in the automatic cooking menu, “steak”, “stir-fried”, “eggaki”, etc. in the appropriate temperature cooking menu. When the menu setting means 71 is pressed, the menu is displayed on the display 81a. Each time the menu setting means 71 is pressed, the menu is switched and displayed. This selects the menu to be used. When the menu setting means 71 sets the appropriate temperature cooking menu of “steak”, “stir fry”, and “eggaki”, the temperature / heating power adjustment means 73 can adjust the set temperature as desired. Description of “cooking rice”, “fried food”, “boiled water” and “boiled” in the automatic cooking menu is omitted.

  In the appropriate temperature cooking menu, the initial value of the set temperature and the adjustment temperature range vary depending on the menu and can be adjusted in increments of 10 ° C. “Steak” has an initial set temperature of 220 ° C., a temperature adjustment range of 190 ° C. to 250 ° C., “Fry” has an initial set temperature of 200 ° C., a temperature adjustment range of 170 ° C. to 230 ° C., and “Fried egg” has an initial set temperature. 170 degreeC and a temperature adjustment range are 140 degreeC-200 degreeC.

  For example, in FIG. 4B, after selecting “stir-fry” for stir-cooking, the set temperature initial value is “200” and increases to 230 ° C. in 10 ° C. increments every time the temperature / heating power adjustment UP key 73b is pressed. Can be set. In the figure, the number indicating the temperature is changed to “220”. Moreover, every time the temperature / heating power adjustment DOWN key 73a is pressed, the temperature can be set to 170 ° C. in 10 ° C. increments.

  In addition, when “Fried Egg” is selected for the fried egg cooking, the change can be made in the same manner. In FIG. 4A, “Fried Egg” is selected and the set temperature is changed from the initial set temperature “170” to the temperature / heat power adjustment DOWN. A display adjusted to “140” by pressing the key 73a is shown.

  FIG. 5 is a diagram for explaining the details of the temperature control by the control means 18. The operation switching unit 91 that switches the operation of the control unit 18 selects a temperature adjustment operation described later when the set temperature is equal to or higher than the threshold temperature 170 ° C. according to the set temperature set by the temperature / thermal power adjusting unit 73, and the set temperature is the threshold temperature. When the temperature is lower than 170 ° C., a switching heating operation described later is selected.

  In the temperature adjustment operation, in order to maintain the average temperature of the pan 30 at the set temperature, when the temperature of the pan detected by the infrared sensor 17 is lower than the set temperature, the temperature of the pan detected by the infrared sensor 17 is set to a predetermined high heating power. When the temperature is higher than the set temperature, control is performed by switching the output of the high-frequency current supplied from the inverter circuit 19 to the heating coil 3 to a predetermined low heating power.

  In the switching heating operation, when the temperature of the pan detected by the infrared sensor 17 is higher than a predetermined temperature, the output of the high-frequency current supplied from the inverter circuit 19 to the heating coil 3 is switched from the predetermined high heating power to the predetermined low heating power. The timer time for determining the timing for switching from the predetermined low heating power to the predetermined high heating power is used.

  Moreover, the temperature of the pan 30 is set by setting the predetermined temperature to a lower limit temperature (for example, 165 ° C.) that can be detected by the infrared sensor 17 and changing the timer time for switching from the predetermined low heating power to the predetermined high heating power. By changing the amplitude of the change greatly, the average temperature can be kept lower than the predetermined temperature.

  The predetermined high thermal power is a high-frequency current output supplied to the heating coil 3 from the inverter circuit 19 in order to increase the temperature of the pan 30, and the predetermined low thermal power is a decrease in the temperature of the pan 30. Therefore, the predetermined low heating power includes a state where the output from the inverter circuit 19 is zero. The predetermined high thermal power and the predetermined low thermal power are not the same in the temperature adjustment operation and the switching heating operation, but are individually set according to the set temperature.

  In the temperature adjusting operation, after the infrared energy detected by the infrared sensor 17 is converted into a detected temperature, the temperature measuring means 92 compares the relationship between the temperature of the pan 30 and the set temperature, and the average temperature of the pan 30 becomes the set temperature. Thus, when the temperature of the pan 30 is lower than the set temperature, the high-frequency current output from the inverter circuit 19 is controlled so that the predetermined high heating power is obtained, and when the temperature of the pan 30 is higher than the set temperature, the predetermined low heating power is obtained. Thus, the high-frequency current output from the inverter circuit 19 is controlled.

  In the switching heating operation, after the infrared energy detected by the infrared sensor 17 is converted into a detected temperature, the temperature measuring means 92 compares the relationship between the temperature of the pan 30 and the set temperature, and the average temperature of the pan 30 becomes the set temperature. Thus, immediately after the start of heating, until the temperature detected by the infrared sensor 17 becomes equal to or higher than the predetermined temperature (for example, 165 ° C.), the output from the inverter circuit 19 is set to a predetermined high heating power in order to increase the temperature of the pan 30. The high frequency current output from the inverter circuit 19 is controlled so that when the temperature of the pan 30 becomes equal to or higher than the predetermined temperature (for example, 165 ° C.), a predetermined low heating power is used to lower the temperature of the pan 30. Control. Further, at the same time when the predetermined high thermal power is switched to the predetermined low thermal power, the elapsed time after the switching is measured by the timer means 93, and the predetermined low thermal power previously stored in the timer time storage means 94 is measured. The predetermined low heating power is maintained in order to lower the temperature of the pan 30 until the maintenance time elapses, and the predetermined high heating power is used to increase the temperature of the pan after the elapsed time has elapsed. The high-frequency current output from the inverter circuit 19 is controlled.

  In the timer time storage means 94, as shown in FIG. 5, the set temperature set by the temperature / heating power adjusting means 73, the number of times of switching to a predetermined low heating power for each set temperature, and the number of times of switching to the predetermined low heating power. The time for maintaining the predetermined low heating power is stored. The time for maintaining the predetermined low heating power differs for each set temperature, and the longer the set temperature is, the lower the average temperature needs to be lowered. Further, the number of times of switching to a predetermined low heating power at the same set temperature becomes longer as the number of times is increased from the second time to the third time and the third time to the fourth time except the first time. Specifically, at the set temperature of 160 ° C., the predetermined low heating power is maintained for 5 seconds for the first time, 4, 5, 6 seconds for the second, third and fourth times, 7 seconds for the fifth time and thereafter, and similarly for 150 ° C. 10 seconds for the first time, 7, 9, 11 seconds for the second, third and fourth times, 13 seconds for the fifth and subsequent times, 15 seconds for the first time at 140 ° C., 13, 16, 19 seconds for the fifth time for the second, third and fourth times After that, it is 22 seconds.

  The present embodiment is configured as described above. Next, an operation example of “stir-fry” and “egg-yaki” will be described in the menu for cooking at an appropriate temperature.

  First, the case where the set temperature is a threshold temperature of 170 ° C. or higher in “sauté” cooking will be described with reference to FIGS.

  When a user cooks “stir-fry” using the heating coil 3 on the right side of the main body 1, the main power switch 9 is first turned on to turn on the power, and the pan 30 (frying pan) used for heating is placed on the right side of the main body 1. Placed in the center of the heating coil 3 and operating the menu setting means 71 of the upper surface operation unit 7a while looking at the display 81a, as shown in FIG. 4B, "stir fry" is displayed on the display 81a. The set temperature initial value “200” displayed on the display 81a is changed to the desired set temperature “220” by operating the temperature / thermal power adjusting means 73. Next, the cut / start key 74 is pressed to start cooking, energize the heating coil 3, and put oil into the pan 30.

When the energization is started, as shown in FIG. 6, “Preheating” is displayed on the display 81b in Step 1, and the pot 30 is heated with a high heating power of 2.0 kW for the first 7 seconds after the energization is started in Step 2. Then, in step 3, the heating power is dropped to a low heating power of 0.5 kW and heated for 5 seconds. In step 4, the heating power is set to a high heating power of 2 kW, and when the temperature detected by the infrared sensor 17 reaches the set temperature T ₀ in step 5, it is determined that the preheating is finished. In step 6, the pot state determination means 20 determines whether the pot 30 is suitable for heating. If it is suitable for heating, the process proceeds to step 7. In step 7, “appropriate temperature” is displayed on the display 81 b and informed, and then the process proceeds to heat retention in step 8 and temperature control is performed so that the temperature of the pan 30 is maintained at the set temperature T ₀ as an average temperature.

  In step 8, since the set temperature is 220 ° C., the operation switching means 91 outputs the output of the inverter circuit 19 according to the temperature of the pan 30 detected by the infrared sensor 17 in order to maintain the average temperature of the pan at the set temperature. A temperature adjustment operation is selected for controlling the high-frequency current to be switched from a predetermined high heating power to a predetermined low heating power and from a predetermined low heating power to a predetermined high heating power. The operation is changed from 2 kW of a predetermined high heating power to 0.3 kW of a predetermined low heating power when the detection temperature of the infrared sensor 17 becomes 220 ° C. or higher, and from 0.3 kW of a predetermined low heating power when the detected temperature becomes 220 ° C. or lower. Change to high heat 2kW and continue heating. Then, the user confirms that “appropriate temperature” is displayed on the display 81b, and puts the ingredients into the pan 30 to perform fried cooking.

  Next, a case where the set temperature is lower than the threshold temperature 170 ° C. will be described with reference to FIGS.

  The user turns on the main power switch 9 to turn on the power to perform the fried egg cooking, puts the pot 30 (frying pan) used for heating in the center of the heating coil 3 on the right side of the main body 1, and operates the upper surface while viewing the display 81a. The menu setting means 71 of the unit 7a is operated to display “Fried egg” on the display 81a as shown in FIG. The temperature / heating power adjusting means 73 is operated to change the set temperature displayed on the display 81a to the desired “140”. Next, the cut / start key 74 is pressed to start cooking, energize the heating coil 3, and put oil into the pan 30.

  When energization is started, as shown in FIG. 8, “Preheating” is displayed on the display 81 b in Step 1. In step 2, heating is performed at a predetermined high heating power of 1.5 kW during preheating, and in step 3, if the temperature detected by the infrared sensor 17 reaches a predetermined temperature of 165 ° C., whether or not the pan 30 is heated by the pan state determination means 20 in step 4. If it is suitable for heating, the process proceeds to step 5. Heating at a predetermined low heating power of 0.1 kW in step 5, the timer means 93 of step 6 timed the first 15 seconds of maintaining the predetermined low heating power stored in the timer time storage means 94, and 15 seconds passed When it is determined that the preheating has been completed, “appropriate temperature” is displayed on the display 81b in step 7 for notification. Thereafter, the process proceeds to heat retention in step 8, and the temperature is controlled so that the average temperature of the temperature amplitude obtained by the switching heating operation becomes substantially the set temperature, and the pan 30 is maintained at the substantially set temperature.

  When "appropriate temperature" is displayed and the process proceeds to the heat retention in step 8, in step 8a, a high frequency current supplied from the inverter circuit 19 to the heating coil 3 by the control means 18 is supplied to the heating coil 3 by the control means 18 so as to reach the predetermined temperature 165 ° C. Energize with. When the temperature reaches 165 ° C. shown in Step 8b, it switches to 0.1 kW of the predetermined low heating power shown in Step 8c. Then, the number of times from the time data table for maintaining the predetermined low heating power with respect to the number of times of switching to the predetermined low heating power determined for each set temperature previously stored in the timer time storage means 94 by the timer means 93 in step 8d is 2, 3, The fourth time is 13, 16, 19 seconds, and after the fifth time, 22 seconds is selected and timed. For example, in the case of the second low thermal power time of 13 seconds, after the passage of 13 seconds, it is switched to a predetermined high thermal power of 1.5 kW, and is processed inside the control means 18 so as to repeat the switching of the thermal power so as to perform the switching heating operation. The output of the inverter circuit 19 is controlled. Then, the user confirms that “appropriate temperature” is displayed on the display 81b, and puts the ingredients into the pan 30 to perform the fried egg.

  Thus, the average temperature of the temperature of the pan 30 is obtained as the substantially set temperature by the switching heating operation of the lower limit predetermined temperature that can be detected by the infrared sensor 17 and the time for maintaining the predetermined low heating power. By maintaining the temperature, it is possible to set a set temperature in cooking at a low temperature such as fried eggs, and since the ingredients can be input at the temperature set by the user, it is possible to cook comfortably without feeling inconvenience during cooking.

  In addition, the time for maintaining the predetermined low thermal power is set so that the number of times of switching to the predetermined low thermal power becomes longer as the number of times increases from the second time to the third time and the third time to the fourth time except the first time. This is to prevent the temperature of the pan 30 from rising due to an increase in the average temperature of the ingredients placed in the pan 30 or the pan 30 by increasing the cooking time.

  In addition, the time for maintaining the initial predetermined low thermal power is long because it takes time for the temperature of the pan 30 to drop due to overshoot that occurs when the initial predetermined high thermal power is switched to the predetermined low thermal power. Is set.

  Although the case where the set temperature is 140 ° C. has been described above, even in the switching heating operation where the set temperature is 150 ° C. and 160 ° C., the predetermined temperature for switching from the predetermined high thermal power to the predetermined low thermal power is the same as 165 ° C. This is possible by adjusting the time for maintaining the thermal power.

  In addition, since the time for maintaining the predetermined low heating power is provided for heating the ingredients, the temperature of the pot 30 increases during the time for maintaining the predetermined low heating power as the amount of eggs put into the pot 30 increases. The temperature of the egg will drop greatly and the average temperature will drop, so even if the time required for baking is increased due to the increase in the amount of eggs, it is possible to heat the egg to the inside without burning the surface. Even if the amount of ingredients put into the pan 30 changes, there is no failure.

  In an actual cooking situation, the temperature of the pan is high immediately after the start of preheating or when the temperature detected by the infrared sensor is high, or when the pan state determination means 20 determines that heating is inappropriate during preheating. However, in the present invention, detailed explanations of the treatment at the time of hot pot and the treatment at inappropriate time for heating are omitted.

  According to the above-described embodiment, the temperature of the pan can be maintained at a temperature suitable for cooking in a low temperature range of 140 to 160 ° C. using an infrared sensor. Automatic cooking can be applied to very difficult fried eggs.

DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 3 Heating coil 15 Temperature sensor 17 Infrared sensor 18 Control means 19 Inverter circuit 71 Menu setting means 73 Temperature / heating power adjustment means 91 Operation switching means 93 Timer means 94 Timer time storage means

Claims (3)

  A top plate provided on the upper surface of the main body, a heating coil provided below the top plate to supply a high-frequency current to heat the pan placed on the top plate, and a high-frequency current to the heating coil An inverter circuit; an infrared sensor for detecting the temperature by infrared rays radiated from the pan through the top plate; a temperature / heating power adjusting means for setting the temperature of the pan; and the temperature of the pan to the set temperature. Control means for switching the high-frequency current output from the inverter circuit to a predetermined high heating power and a predetermined low heating power to maintain the timer, and a timer time storage means for storing a time for maintaining the predetermined low heating power; Timer means for measuring the time for maintaining the predetermined low heating power, and in order to maintain the temperature of the pan at a set temperature on average, the infrared When the sensor detects a temperature equal to or higher than a predetermined temperature, the output of the inverter circuit is switched to a predetermined low thermal power, and the timer means is operated from the time when the output is switched to the predetermined low thermal power, and the time for maintaining the predetermined low thermal power is counted. Then, the output of the inverter circuit is switched to the predetermined high heating power.   The time for maintaining the predetermined low thermal power stored in the timer time storage means is increased every time the number of times of switching to the predetermined low thermal power is increased from the second to the third time, and from the third time to the fourth time except the first time. The induction heating cooker according to claim 1.   The control means sets the output of the inverter circuit to a predetermined low heating power when the temperature detected by the infrared sensor detects a temperature equal to or higher than a set temperature when the set temperature set by the temperature / heating power adjusting means is equal to or higher than a threshold temperature. The control of setting the output of the inverter circuit to a predetermined high heating power and maintaining the temperature of the pan at the set temperature when the detection temperature of the infrared sensor detects a temperature lower than the set temperature is performed. The induction heating cooker described.

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