JP5047222B2 - Electromagnetic cooker - Google Patents

Description

  The present invention relates to an electromagnetic cooker that controls the oil temperature during frying.

  A conventional electromagnetic cooker includes a glass top plate for holding a pan, infrared detection means for detecting infrared rays from the pan through the glass top plate, and temperature detection means for detecting the temperature of the pan from the output of the infrared detection means, A control means for switching the output of the heating coil downward at a preset temperature in the oil preheating step according to the output of the temperature detection means and the set temperature at the operation unit, and controlling the oil to reach the set temperature; Oil amount determination means for determining the oil amount in the pan according to the rising temperature from the temperature determination value of 1 to the second temperature determination value (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2003-92177 (Claims 1, 3 and 1)

By the way, the above-mentioned glass top plate does not pass the wavelength of 2.5 μm or more, and the wavelength of the temperature of 500 K (227 ° C.) or less is cut by the glass top plate at the wavelength of 2.5 μm or less. Was detected only at a temperature around 180 ° C.
The present invention has been made to solve the above-described problems. An electromagnetic cooker that accurately controls the oil temperature regardless of the amount of oil in the cooking pan and regardless of the warped state of the pan bottom. The purpose is to provide.

An electromagnetic cooker according to the present invention includes a top plate on which a cooking pan is placed, a heating coil that is installed under the top plate and that heats the cooking pan placed on the top plate, and an alternating voltage is converted to a high-frequency voltage. A drive circuit that converts and supplies high-frequency current to the heating coil, a control circuit that detects the output power of the heating coil and controls the drive circuit so that the power becomes set power, and is provided above the top plate, Infrared sensor that receives infrared rays radiated from the side of the cooking pan, and pan temperature calculation unit that calculates the pan side temperature based on the amount of infrared rays received by the infrared sensor, the control circuit starts the fried food cooking mode Once a predetermined time, and controls the driving circuit to a predetermined power, the first predetermined time of the predetermined time, the change value or pot sides therebetween in amount of infrared rays Determining a positional relationship between the heating coil cooking pot seeking every change value, then, in the second predetermined time of the predetermined time, it obtains the change in value of the change value or pan side temperature between the infrared-amount basic Judge the amount of oil, calculate the amount of oil in the cooking pan by correcting the basic oil amount from the positional relationship between the cooking pan and the heating coil determined earlier, and select the gain of temperature feedback control based on that oil amount The gain of the temperature feedback control increases as the oil amount increases, and decreases as the oil amount decreases.

  In the present invention, when the deep-fried food cooking mode is started, the drive circuit is controlled to be at a predetermined power for a predetermined time, and during the first predetermined time of the predetermined time, the amount of infrared rays or the temperature of the pan side surface during that time is changed. Determine the positional relationship between the cooking pan and the heating coil by determining the value, and then determine the basic oil amount by determining the amount of infrared rays or the temperature change of the pan side surface during the second predetermined time of the predetermined time, And the basic oil amount was corrected from the positional relationship between the cooking pan and the heating coil determined earlier, the oil amount in the cooking pan was calculated, and the gain of temperature feedback control was selected based on the oil amount. Regardless of the amount of oil in the cooking pan and the warping state of the pan bottom, the oil temperature does not overshoot and temperature control can be performed with high accuracy.

It is a block diagram which shows the structure of the electromagnetic cooker which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the positional relationship of a cooking pan and a heating coil when a cooking pan is mounted in the heating port. It is sectional drawing which shows the positional relationship of a cooking pan and a heating coil when a cooking pan shifts | deviates to the infrared sensor side and is mounted in the heating port. It is a curve figure of the pan side surface temperature which changes according to the positional relationship of a cooking pan and a heating coil, and the oil quantity in a cooking pan. It is a figure which shows the correlation with the differential value of 1st predetermined time t1, and the correction coefficient K. FIG. It is a figure which shows the correlation with the differential value of 2nd predetermined time t2, and the basic oil amount L. FIG. It is a figure which shows the correlation with the oil amount (basic oil amount xK) in a cooking pan, and the feedback gain FG. It is a figure which shows the correlation with the oil amount (basic oil amount Lx correction coefficient K) of the cooking pan in Embodiment 2, and a threshold value. It is a figure which shows the correlation with the oil amount (basic oil amount LxK) of cooking pot, and input electric power. It is a block diagram which shows the structure of the electromagnetic cooker which concerns on Embodiment 4 of this invention. It is a diagram of the amount of curvature of the pan bottom showing the correlation between the differential value of the first predetermined time t1 and the temperature difference between the pan side surface temperature and the thermistor temperature. It is a figure which shows the correlation with the curvature amount of a pan bottom, and the correction coefficient Ks of the thermistor temperature.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of the electromagnetic cooking device according to Embodiment 1 of the present invention.
In FIG. 1, the top plate 3 attached to the upper part of the main body 11 is comprised by the heat resistant tempered glass and the metal frame (not shown) attached to the outer periphery of the glass. A circular heating port (not shown) indicating the heating position of the cooking pan 1 is displayed on the surface of the heat-resistant tempered glass of the top plate 3. In addition, an annular heating coil 4 is provided below the top plate 3 so as to face the above-described heating port. The heating coil 4 induction-heats the cooking pan 1 on the top plate 3 based on a high-frequency current from a drive circuit 6 described later.

  For example, the infrared sensor 5 provided on the upper side of the top plate 3 is attached to the above-described frame so as to face the side surface of the cooking pan 1, and receives infrared rays emitted from the side surface of the cooking pan 1. The drive circuit 6 includes an inverter circuit, drives the inverter circuit based on control from the control circuit 7 described later, converts the alternating voltage 8 into a high frequency voltage, and supplies the high frequency current to the heating coil 4. The control circuit 7 calculates the input power from the input current detected by the current detector 9 composed of, for example, a current transformer and the input voltage detected by the voltage detector 10, and the heating power set by the operation unit The drive circuit 6 is controlled so that

Next, the pan side temperature which changes according to the positional relationship between the cooking pan 1 and the heating coil 4 and the amount of oil in the cooking pan 1 will be described.
2 is a cross-sectional view showing the positional relationship between the cooking pan and the heating coil when the cooking pan is placed in the heating port, and FIG. 3 is a cooking when the cooking pan is shifted to the infrared sensor side and placed on the heating port. Sectional drawing which shows the positional relationship of a pan and a heating coil, FIG. 4 is a curve figure of the pan side surface temperature which changes according to the positional relationship of a cooking pan and a heating coil, and the oil amount in a cooking pan. In addition, t1 shown in FIG. 4 is the first predetermined time, t2 is the second predetermined time, and the curve indicates the pan side surface temperature from the start of heating until the second predetermined time t2 elapses.

  As shown in FIG. 3, when the side surface on the infrared sensor 5 side of the cooking pan 1 protrudes from the heating coil 4, the pan bottom a and the pan side b opposite to the infrared sensor 5 are first caused by the magnetic flux from the heating coil 5. Directly heated, the heat is transmitted to the side of the pan on the infrared sensor 5 side through the oil 2 of the cooking pan 1. Therefore, the temperature rise on the side of the pan on the infrared sensor 5 side is small. On the other hand, when the cooking pan 1 is inside the heating coil 4 as shown in FIG. 2, since the pan side b surrounded by the dotted line is directly heated by the magnetic flux from the heating coil 4 together with the pan bottom a, the infrared sensor 5 The temperature rise on the side of the pan is large. As shown in FIG. 4, in the heating for the first predetermined time t <b> 1, since the heat transfer coefficient of the cooking pot 1 is larger than the heat transfer coefficient of the oil 2, the cooking pot 1 is first heated. In this case, the influence of the positional relationship between the cooking pan 1 and the heating coil 4 is greater than the amount of oil, and heat is transferred to the oil 2 as the heating proceeds, and the slope of the temperature rise changes according to the amount of oil. Moreover, even if it is the same oil quantity, the direction where the cooking pan 1 exists in the inside of the heating coil 4 has large inclination of a temperature rise.

  Therefore, in the first embodiment, the driving circuit 6 is controlled so as to have a predetermined power for a predetermined time, and at the first predetermined time t1 in the predetermined time, the change value of the pan side surface temperature is obtained during cooking. The positional relationship between the pan 1 and the heating coil 4 is determined, and then, at the second predetermined time t2 of the predetermined time, the change value of the pan side temperature during that time is determined, the basic oil amount is determined, and the determination is made first. The amount of oil in the cooking pan 1 is calculated from the positional relationship between the cooking pan 1 and the heating coil 4, a gain of temperature feedback control is selected based on the amount of oil, and the power of the heating coil 4 is controlled. .

Next, the series of processes described above will be described in detail with reference to FIGS.
FIG. 5 is a diagram showing the correlation between the differential value at the first predetermined time t1 and the correction coefficient K, FIG. 6 is a diagram showing the correlation between the differential value at the second predetermined time t2 and the basic oil amount L, and FIG. It is a figure which shows the correlation with the oil amount (basic oil amount xK) in a cooking pan, and the feedback gain FG.

  The above-described processing is performed by the control circuit 7 of the cooker. The control circuit 7 includes a pan temperature calculating unit that calculates the pan side surface temperature based on the amount of infrared light received by the infrared sensor 5 so that when the deep-fried food cooking switch is turned on, the control circuit 7 has predetermined power for a predetermined time. The drive circuit 6 is controlled. At this time, at the first predetermined time t1 of the predetermined time, the pan side surface temperature during that time is time-differentiated to calculate a differential value (change value). Next, as shown in FIG. 5, it is determined whether the differential value is equal to or greater than a predetermined value T1, and when the differential value is equal to or less than the predetermined value T1, it is determined that the cooking pan 1 is shifted to the infrared sensor 5 side. The correction coefficient K is set to 1.0. Further, when the differential value is larger than the predetermined value T1, it is determined that the cooking pot 1 is placed on the inner side of the heating coil 4 or on the opposite side of the infrared sensor 5, and is set according to the differential value. A correction coefficient K (a value smaller than 1.0) is selected.

  Thereafter, the control circuit 7 calculates the differential value (change value) by time-differentiating the pan side surface temperature during the second predetermined time t2 of the predetermined time, and the basic oil set according to the differential value The quantity L is selected (see FIG. 6). Then, the basic oil amount L is multiplied by the correction coefficient K previously selected to obtain the oil amount in the cooking pan 1, and a feedback gain FG set according to the oil amount is selected as shown in FIG. And gain of temperature feedback control. The feedback gain FG increases as the oil amount increases and decreases as the oil amount decreases.

  Although the pan side surface temperature calculated by the pan temperature calculating unit is time-differentiated, the amount of infrared rays received by the infrared sensor may be time-differentiated instead. The calculation of the differential value of the pan side surface temperature will be described in detail when the operation is described.

In the electromagnetic cooker configured as described above, when the power source is turned “on” by the operation unit, and the deep-fried food cooking mode is started by turning on the deep-fried food cooking switch, the control circuit 7 The drive circuit 6 is controlled so that At this time, the infrared ray amount P from the side of the cooking pan 1 received by the infrared sensor 5 and the temperature T _O of the infrared sensor 5 itself are read, the infrared emissivity of the cooking pan 1 is ε, the Stefan-Boltzmann constant is σ, the side of the pan The pan side surface temperature Ta is calculated from the following equation (1) where the temperature is Ta.
P = σ (εTa ⁴ −εTo ⁴ ) (1)

Thereafter, when the start of heating has elapsed a first predetermined time t1, the amount of infrared rays P emitted from the side surface of the cooking pot 1 received through the infrared sensor 5 reads the temperature T _O of the infrared sensor 5 itself The pan side surface temperature Ta is calculated from the above equation (1). Next, time differentiation is performed with the previously calculated pan side surface temperature Ta, and a differential value of the pan side surface temperature Ta is calculated.

  Next, the control circuit 7 determines whether or not the calculated differential value is larger than a predetermined value T1 that is set in advance (see FIG. 5). And the correction coefficient K is set to 1.0. Further, when the differential value is larger than the predetermined value T1, it is determined that the cooking pot 1 is placed on the inner side of the heating coil 4 or on the opposite side of the infrared sensor 5, and is set according to the differential value. A correction coefficient K (a value smaller than 1.0) is selected.

Thereafter, the control circuit 7 receives the infrared ray amount P radiated from the side surface of the cooking pan 1 through the infrared sensor 5 in the same manner as described above when entering the measurement of the second predetermined time t2, and the infrared sensor 5 The temperature T _O of itself is read, and the pan side surface temperature Ta is calculated from the above-described equation (1). When the second predetermined time t2 has elapsed, the amount of infrared rays P emitted from the side surface of the cooking pot 1 received through the infrared sensor 5 reads the temperature T _O of the infrared sensor 5 itself, the above-mentioned ( 1) The pan side surface temperature Ta is calculated from the equation. Next, time differentiation is performed with the previously calculated pan side surface temperature Ta, a differential value of the pan side surface temperature Ta is calculated, and a basic oil amount L set according to the differential value is selected (see FIG. 6). Then, the amount of oil in the cooking pan 1 is calculated by multiplying the basic oil amount L by the correction coefficient K previously selected.

  For example, when the cooking pan 1 is inside the heating coil 4, the differential value at the first predetermined time t <b> 1 increases as the oil amount decreases, so the correction coefficient K decreases. Although the differential value at the second predetermined time t2 is smaller than that at the first predetermined time t1, it becomes larger as the oil amount is smaller, so the basic oil amount L becomes smaller. For this reason, the amount of oil in the cooking pot 1 is estimated to be small. Further, since the differential value at the first predetermined time t1 becomes smaller as the amount of oil increases, the correction coefficient K increases. Although the differential value at the second predetermined time t2 is smaller than that at the first predetermined time t1, the smaller the oil amount, the smaller the basic oil amount L. For this reason, a large amount of oil in the cooking pan 1 is estimated.

  When the cooking pan 1 is on the infrared sensor 5 side and the correction coefficient K is 1.0 based on the differential value at the first predetermined time t1, the differential value at the second predetermined time t2 is the oil amount. As the amount of oil increases, the amount of basic oil L increases, and the amount of oil in the cooking pan 1 is estimated to be large. Conversely, since the differential value at the second predetermined time t2 increases as the oil amount decreases, the basic oil amount L decreases compared to when the differential value is small, and the oil amount in the cooking pan 1 is estimated to be small. .

  After estimating the amount of oil in the cooking pan 1, a feedback gain FG set in accordance with the amount of oil is selected (see FIG. 7) and used as a gain for temperature feedback control. And the target temperature Tobj of fried food cooking and the pan side surface temperature Ta are compared, and when the pan side surface temperature Ta is low, electric power will be supplied to the heating coil 4 after 2 second predetermined time t2. The power at this time is proportional to FG (Tobj−Ta).

  As described above, according to the first embodiment, when the deep-fried food cooking mode is started by turning on the deep-fried food cooking switch, the drive circuit 6 is controlled to be at a predetermined power for a predetermined time, and the first time in the predetermined time. At a predetermined time t1, the pan side surface temperature Ta during that time is differentiated with respect to time to obtain a differential value, a correction coefficient K is selected from the differential value, and then at a second predetermined time t2 of the predetermined time, the pan during that time The side temperature Ta is differentiated with respect to time to obtain a differential value, the basic oil amount L is selected from the differential value, and the oil amount in the cooking pan 1 is calculated from the correction coefficient K selected earlier, and the oil amount is calculated. Since the gain FG of the temperature feedback control is selected based on this, overshoot of the oil temperature is eliminated regardless of the amount of oil in the cooking pan 1 and the warped state of the pan bottom, and temperature control can be performed with high accuracy.

  In the first embodiment, the correction coefficient K is selected from the differential value of the pan side surface temperature Ta obtained at the first predetermined time t1, and the basic value is derived from the differential value of the pan side surface temperature Ta obtained at the second predetermined time t2. The oil amount L is selected, and the basic oil amount L is multiplied by the previous correction coefficient K to obtain the oil amount in the cooking pan 1. When the oil amount is, for example, 200 g (predetermined amount) or less. You may make it alert | report that there is little oil amount in the cooking pan 1 to a user with a liquid crystal display part, LED, or an audio | voice by stopping control of fried food cooking mode. When comprised in this way, when the amount of oil in the cooking pan 1 is small, it can prevent that oil temperature goes up too much, and safety improves more.

Embodiment 2. FIG.
In the second embodiment, in the electromagnetic cooker of the first embodiment described above, when the temperature optimal for fried food cooking (for example, 180 ° C.) has been reached, the pan side surface temperature Ta suddenly drops due to the addition of ingredients. The heating is performed by adding a predetermined power to the current power.

  FIG. 8 is a diagram showing the correlation between the amount of oil in the cooking pan (basic oil amount L × correction coefficient K) and the threshold in Embodiment 2, and FIG. 9 is the amount of oil in the cooking pan (basic oil amount L × K). It is a figure which shows the correlation with input electric power. Note that the oil input threshold shown in FIG. 8 will be described in a third embodiment to be described later. Moreover, since the structure of the electromagnetic cooking device of Embodiment 2 is the same as that of Embodiment 1, it demonstrates using FIG.

  When the oil temperature of the cooking pan 1 reaches a predetermined temperature (for example, 180 ° C.) that is optimal for deep-fried food cooking, the control circuit 7 of the electromagnetic cooker in the second embodiment sets the pan side surface temperature Ta between the predetermined intervals. Is differentiated with respect to time to calculate a differential value (change value), and the differential value is set in accordance with the oil amount (basic oil amount L × correction coefficient K). It is determined whether or not it has changed in the negative direction. When the differential value changes in the negative direction beyond the food material input threshold, it is determined that the food material has been input into the cooking pan 1, and the power set according to the amount of oil is added to the current power and heated. As shown in FIG. 8, the food material input threshold decreases as the amount of oil in the cooking pan 1 increases, and increases as the amount of oil decreases.

  The pan side temperature Ta is obtained from the equation (1) as described in the first embodiment. In addition, as in the first embodiment, the oil amount described above is selected from the differential value of the pan side surface temperature Ta obtained at the first predetermined time t1, and the pan obtained at the second predetermined time t2. This is obtained by selecting the basic oil amount L from the differential value of the side surface temperature Ta and multiplying the basic oil amount L by the correction coefficient K. Although the pan side surface temperature calculated by the pan temperature calculating unit is time-differentiated, the amount of infrared rays received by the infrared sensor may be time-differentiated instead.

  As described above, according to the second embodiment, when the amount of oil in the cooking pan 1 is large, the food material input threshold value is reduced, so that the input of the food material can be reliably detected even when the oil amount is large, Since the threshold is raised when the amount of oil in the cooking pan 1 is small, erroneous determination due to the insertion of chopsticks or the like can be prevented. In addition, the addition of electric power when food is added is changed according to the amount of oil, so temperature recovery from the temperature drop state due to food input is performed without overshoot, and the optimal temperature for fried food cooking Can be maintained and delicious cooking becomes possible.

Embodiment 3 FIG.
In the electromagnetic cooker according to the second embodiment described above, the third embodiment is configured such that when the oil 2 is additionally introduced when the temperature (for example, 180 ° C.) is optimal for fried food cooking, The oil amount is calculated again. The determination as to whether or not the oil 2 is additionally charged will be described with reference to FIG. In addition, since the structure of the electromagnetic cooker of Embodiment 3 is the same as that of Embodiment 1, it demonstrates using FIG.

  The control circuit 7 of the electromagnetic cooker according to the third embodiment is configured such that the differential value (change value) of the pan side surface temperature Ta calculated every predetermined interval is set according to the amount of oil (first threshold). Value) Determine whether or not the oil input threshold value has changed in the negative direction beyond the threshold value. When the above-mentioned differential value changes in the negative direction beyond the food material input threshold set in accordance with the amount of oil, it is determined that the food material has been input into the cooking pan 1 as described above. When it changes to the minus direction more than a threshold value, it determines with the oil 2 having been poured into the cooking pan 1, and calculates oil amount again. As shown in FIG. 8, the oil input threshold is higher than the food input threshold, decreases as the amount of oil in the cooking pan 1 increases, and increases as the amount of oil decreases.

  For example, when the oil 2 is introduced into the cooking pan 1, the recalculation of the oil amount is performed by providing each period corresponding to the first predetermined time t1 and the second predetermined time t2 described in the first embodiment, The differential value (time differential) of the pan side surface temperature Ta is calculated for each. Then, the correction coefficient is determined from the differential value in the first period, the basic oil amount is determined from the differential value in the next period, and then, the new oil amount is obtained by multiplying the basic oil amount by the previous correction coefficient. . Then, the electric power set according to the new oil amount is added to the current electric power and heated.

  As described above, according to the third embodiment, when the amount of oil in the cooking pan 1 is large, the oil input threshold value is reduced. Therefore, even when the amount of oil is large, the input of oil 2 can be reliably detected. Since the threshold value is raised when the amount of oil in the cooking pan 1 is small, erroneous determination can be prevented. Moreover, since the addition of electric power when oil 2 is input is changed according to the new oil amount, temperature recovery from the temperature drop state due to oil input is performed without overshooting, and fried food cooking The optimum temperature can be maintained, and delicious cooking becomes possible.

Embodiment 4 FIG.
FIG. 10 is a block diagram showing the configuration of the electromagnetic cooking device according to Embodiment 4 of the present invention, and FIG. 11 shows the correlation between the differential value of the first predetermined time t1, the temperature difference between the pan side surface temperature and the thermistor temperature. FIG. 12 is a diagram showing the correlation between the amount of warpage of the pan bottom and the correction coefficient Ks of the thermistor temperature. In FIG. 10, the same parts as those in the first embodiment described in FIG.

  As shown in FIG. 10, the electromagnetic cooker according to the fourth embodiment includes a thermistor 21 in addition to the infrared sensor 5. The thermistor 21 is installed in contact with the back surface of the top plate 3 in the central space of the heating coil 4 and is connected to a control circuit 7 described later.

  The control circuit 7 described above includes a pan temperature detection unit that detects the pan bottom temperature of the cooking pan 1 on the top plate 3 via the thermistor 21. When the frying cooking mode is started by turning on the frying cooking switch, the cooking pan The drive circuit 6 is controlled so that the temperature of 1 becomes a predetermined temperature (for example, 180 ° C.) optimum for cooking fried food. At this time, the pan side surface temperature Ta during the predetermined time t1 from the start of heating is time-differentiated to calculate a differential value (change value). Next, the pan bottom temperature Ts of the cooking pan 1 on the top plate 3 is detected via the thermistor 21, and the pan bottom temperature Ts is subtracted from the pan side surface temperature Ta to calculate the temperature difference. Thereafter, as shown in FIG. 11, it is determined whether there is a warp in the pan bottom from the above-described differential value and temperature difference.

  When it is determined from the differential value and the temperature difference that there is no warping at the bottom of the pan, feedback control is performed using the pan bottom temperature Ts detected by the thermistor 21 as the temperature of the cooking pan 1. Further, when it is determined that the pan bottom is warped from the differential value and the temperature difference, the warpage amount is determined (see FIG. 11), and a correction coefficient Ks set according to the warpage amount is selected (see FIG. 12). . Then, the pan bottom temperature Ts detected by the thermistor 21 is multiplied by the correction coefficient Ks, and feedback control is performed as the temperature of the cooking pan 1.

  As described above, according to the fourth embodiment, when the amount of warpage of the pan bottom is determined from the differential value of the pan side surface temperature Ta and the temperature difference obtained by subtracting the pan bottom temperature Ts from the pan side surface temperature Ta, according to the amount of warpage. Since the pan temperature Ts detected by the thermistor 21 is corrected (multiplied) by the set correction coefficient Ks, the thermistor 21 can accurately set the temperature of the cooking pan 1 even if the cooking pan 1 is warped. It can be detected and the temperature can be controlled accurately.

  In the fourth embodiment, the amount of warping of the pan bottom is determined from the differential value of the pan side temperature Ta and the temperature difference obtained by subtracting the pan bottom temperature Ts from the pan side temperature Ta. The temperature difference between the side surface temperature Ta and the pan bottom temperature Ts detected by the thermistor 21 is calculated. You may make it alert | report to a user by a part, LED, or an audio | voice. This is a case where fried food cooking is performed by the cooking pot 1 in which the warping of the pot bottom is extremely large. With this configuration, it is possible to prevent the oil temperature from extremely rising when the cooking pan 1 having a large warp is used, and the safety is improved.

  Also, either one of the temperature of the cooking pan 1 obtained by correcting the pan side temperature Ta detected by the infrared sensor 5 or the pan bottom temperature Ts detected by the thermistor 21 is, for example, 250 ° C. (second predetermined value) of oil. ) When the temperature rises above, control of the fried food cooking mode may be stopped and heating of the cooking pan 1 by the heating coil 4 may be stopped. In this case as well, the user is notified of this by the liquid crystal display unit, LED, or voice as described above. With this configuration, the oil temperature can be prevented from becoming abnormally high, and the safety is further improved.

  In each of the embodiments described above, it has been described that the above formula (1) is used for calculating the pan side surface temperature Ta. However, for example, 0.2 is used for the infrared emissivity ε in the formula. May be. This 0.2 is the infrared emissivity ε of the dedicated cooking pan of this cooker. By using the infrared emissivity ε for the calculation of the pan side surface temperature Ta, accurate temperature calculation becomes possible.

  1 cooking pot, 2 oil, 3 top plate, 4 heating coil, 5 infrared sensor, 6 drive circuit, 7 control circuit, 9 current detector, 10 voltage detector, 21 thermistor.

Claims (4)

A top plate on which the cooking pan is placed;
A heating coil that is installed under the top plate and heats the cooking pan placed on the top plate;
A drive circuit for converting an alternating voltage into a high frequency voltage and supplying a high frequency current to the heating coil;
A control circuit that detects the output power of the heating coil and controls the drive circuit so that the power becomes a set power;
An infrared sensor that is provided above the top plate and receives infrared rays emitted from the side surface of the cooking pan;
A pan temperature calculating unit that calculates a pan side surface temperature based on the amount of infrared light received by the infrared sensor;
When the deep-fried food cooking mode is started, the control circuit controls the drive circuit so as to have a predetermined power for a predetermined time, and a change value of the infrared amount during the first predetermined time among the predetermined time. Or the change value of the said pan side temperature is calculated | required, the positional relationship of a cooking pan and the said heating coil is determined, Then, in the 2nd predetermined time among the said predetermined time, the change value of the said infrared amount in the meantime or the said pan side surface The basic oil amount is determined by determining the temperature change value, and the basic oil amount is corrected from the positional relationship between the cooking pan and the heating coil determined earlier, and the oil amount in the cooking pan is calculated. select a gain of temperature feedback control based on,
A gain of the temperature feedback control increases as the amount of oil increases, and decreases as the amount of oil decreases .   2. The electromagnetic cooker according to claim 1, wherein when the calculated amount of oil is equal to or less than a predetermined amount, the control circuit stops control of the deep-fried food cooking mode and notifies the user that the amount of oil is small. . When the oil temperature reaches a predetermined temperature, the control circuit calculates a change value of the infrared amount or a change value of the pan side surface temperature at predetermined intervals, and the change value is set according to the oil amount. It is determined whether or not the first threshold value is changed in the negative direction, and when the change value is changed in the negative direction more than the first threshold value, it is determined that the ingredients are put in the cooking pan, Select the input power from the oil amount and heat in addition to the current power,
The electromagnetic cooker according to claim 1 or 2 , wherein the input electric power increases as the amount of oil increases .   The control circuit determines whether or not the change value has changed in a minus direction by a second threshold value higher than the first threshold value set according to the oil amount, and the change value is second. 4. The electromagnetic cooker according to claim 3, wherein when it changes in a minus direction more than a threshold value, it is determined that oil has been put into the cooking pan and the amount of oil is calculated again.

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