JP2011249203A - Electromagnetic cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique for suppressing firing of oil by heating a pan in a low-power state of power supply to an excitation coil when the pan is heated to temperature equal to or higher than predetermined temperature since kind determination means of determining the kind of the pan placed on a top plate is provided so as to determine the kind of the pan placed on the plate and to perform temperature control matching the pan, and heating is started with high input in a state the pan placed on the top plate is at considerably high temperature like a pan which is used once and not cooled enough, so that the oil in the pan fires to possibly cause danger.SOLUTION: An electromagnetic cooker includes temperature determination means of determining whether a cooking container is in a heating state of temperature equal to or higher than the predetermined temperature, and the kind of the pan is determined in a high-power state of power supply to the excitation coil when the temperature determination means determines that the pan is not in a heating state,and in a low-power state of the power supply to the excitation coil so as to suppress firing of the oil in the pan when the temperature determination means determines that pan is in the heating state.

Description

  The present invention relates to an electromagnetic cooker in which a cooking container generates heat due to electromagnetic induction caused by an electric current flowing in an exciting coil, and the oil in the cooking container can be heated to make a fried food or the like.

  The electromagnetic cooker includes an exciting coil wound in a flat shape so as to correspond to the bottom surface of the cooking vessel (also referred to as pan) on the lower side of the top plate of the electromagnetic cooking device on which the cooking vessel (also referred to as pan) is placed. There is an electromagnetic cooker in which a cooking container generates heat by an electromagnetic induction effect caused by an electric current flowing through the exciting coil, and the oil in the cooking container can be heated to make a fried food or the like (see Patent Document 1). In this case, when using an electromagnetic cooker, a cooking container (also referred to as a pan) that generates heat satisfactorily by electromagnetic induction is required, so that a recommended pan is usually specified for each electromagnetic cooker. In particular, when fried (general name including both tempura and fried foods), if the temperature of the oil in the pan is not properly controlled, the quality of the fried food will be reduced. The recommended pan is one in which the size and material of the pan (this is referred to as the type of pan) is specified, and a steel pan of a predetermined size is usually used.

  If this recommended pan is made of iron, but other pans, such as stainless steel pans, are used, the desired fried food cannot be achieved, so the pan material on the induction cooker Technology to determine whether or not the material is made of iron, and if it is made of iron, it shifts to the desired heating state, but if it is not made of iron, it is determined that it cannot be used and does not shift to the heated state There is.

JP 2003-86343 A

  As described above, the electromagnetic cooker has a mechanism in which a pan placed on the electromagnetic cooker generates heat by an electromagnetic induction action, and thus the types of pans to be used are limited. And in an electromagnetic cooker, the system which detects the temperature of oil indirectly is employ | adopted as control for maintaining the temperature of the oil in a pan at predetermined temperature (it is said to maintain this at heat retention temperature). For this reason, it is the structure which detects the temperature of the pan which rose by heating with the temperature detection sensor arrange | positioned under the top plate of the electromagnetic cooker which mounts a pan. When a predetermined iron pan is used, a reference value is set as to what temperature the temperature detection sensor detects, and the temperature of the oil in the pan becomes a predetermined heat retention temperature. The technology that controls the temperature of the oil in the pan to the predetermined heat-retaining temperature while comparing the reference value with the temperature detected by the temperature detection sensor from time to time after energization is started. is there.

  The present invention is a type determining means for determining the type of a pan placed on the top plate in order to determine the type of the pan placed on the top plate and perform temperature control corresponding to the pan. Is provided. In this case, if the pan placed on the top plate has been used once and started to be heated at a high temperature at a considerable temperature, the oil in the pan will ignite. Become dangerous. For this reason, the present invention is designed to suppress the ignition of oil by heating the energizing coil in a low-power state if the pan is heated to a temperature that is equal to or higher than a predetermined temperature or exceeds a predetermined temperature. is there.

In addition, the electromagnetic cooker is a mechanism in which the pan placed on it generates heat due to electromagnetic induction, so the types of pans that are suitable for frying (general names including both tempura and fried foods) are limited. In the state where only one type can be used, the usability is bad.
In view of this point, an object of the present invention is to improve the usability by allowing a plurality of types of pans suitable for fried foods to be used.

  When a pan is placed on an electromagnetic cooker and heating is started by an excitation coil with a predetermined input, the temperature detected by the temperature sensor when the pan is made of iron, and the temperature detection when a pan of another material is used The temperature detected by the sensor is different. This is because the temperature of the pan generated by heating differs depending on the material of the pan, and the temperature detected by the temperature detection sensor differs. In the control based on the detection of the temperature detection sensor, the temperature of the oil put in the pan is a predetermined value. It will deviate from the heat retention temperature (for example, 180 ° C.). For this reason, it is necessary to carry out appropriate heating control for maintaining the oil at a predetermined heat-retaining temperature depending on what kind of pan (the material of the pan) placed on the electromagnetic cooker.

  In view of this point, the present invention provides a control method for maintaining oil at a predetermined heat-retaining temperature even when different types of pans are used. The present invention provides a technique for determining the type of pan (the material of the pan in the embodiment) before the oil is heated to a predetermined temperature.

  Further, the present invention is in a state where the temperature of the pan placed on the electromagnetic cooker is high before determining what kind of pan (the material of the pan in the embodiment) the pan placed on the electromagnetic cooker is. If the temperature is high, heating is started in a low input state, thereby providing a technique for avoiding the danger of causing oil ignition.

In the first invention, a switching element is provided so as to control energization to an exciting coil disposed under the top plate of the main body of the electromagnetic cooker, and a drive circuit for driving the switching element and a control signal given to the drive circuit A controller that controls the high-frequency power supplied to the exciting coil to be close to a target power value; and a type determining unit that determines the type of the cooking container (or pan) placed on the top plate. In an electromagnetic cooker configured to maintain the oil in the cooking container (or pan) at a predetermined heat-retaining temperature with a control suitable for the type,
A temperature determining means for determining whether or not the cooking container (or pan) is heated to a temperature equal to or higher than a predetermined temperature or exceeding a predetermined temperature;
When it is determined by the temperature determination means that it is not in a heated state, the determination is executed while the energization of the exciting coil is in a high power state, and when the temperature determination means determines that it is in a heated state, the cooking container The determination is performed when energization of the excitation coil is in a low power state so as to suppress the ignition of oil in the (or pan).

  A second invention is characterized in that, in the first invention, the temperature determination means is configured to detect the temperature of the cooking container (or pan) by a temperature detection sensor disposed in a central portion of the exciting coil. To do.

  According to a third invention, in the first invention or the second invention, the type determining means determines whether the cooking container (or pan) is different depending on the driving frequency of the control signal when the cooking container (or pan) is heated with a constant input. ) Is determined.

  According to a fourth invention, in the first invention or the second invention, the type determining means is configured such that when the drive frequency of the control signal exceeds a predetermined upper limit value or exceeds a predetermined upper limit value, the cooking container of the first type material If it is equal to or less than a predetermined lower limit value or less than a predetermined lower limit value, it is determined as a cooking container of the second type of material, and if it is within the range between the upper limit value and the lower limit value, cooking of the third type material is performed. It is characterized by comprising material determining means for determining a container.

  In a fifth aspect based on the first aspect or the second aspect, the type determining means selects the material of the cooking container (or pan) depending on whether the driving frequency of the control signal is higher or lower than a predetermined upper limit value. 1st determination means to determine, and the material determination means provided with the 2nd determination means to determine the material of the said cooking container (or pan) by whether it is high or low with respect to a predetermined | prescribed lower limit. It is characterized by.

  In the present invention, when the type of a cooking container (or pan) is determined, if the cooking container (or pan) in a heated state starts to be heated at a high input, the temperature of the oil in it suddenly increases and ignition occurs. There is a possibility, but in the case of a cooking container (or pan) in a heated state, it is heated at a low input by determining whether or not the cooking container (or pan) is heated in advance by the temperature judging means. In order to start, the intended type determination can be performed while avoiding the danger.

  Moreover, since this invention is the structure which detects the temperature of a cooking container (or pan) with the temperature detection sensor arrange | positioned in the center part of an exciting coil, the temperature detection in a temperature determination means is the structure of a cooking container (or pan). Even if the sizes are different, regular temperature detection is possible and stable control is possible.

  Further, the present invention determines the material of the pan based on the difference in the driving frequency when the pan is heated with a constant input, so that the oil is brought to a predetermined heat retaining temperature by a control operation corresponding to the determined pan material. Can be controlled.

  In addition, the present invention allows the use of cooking containers made of at least three kinds of materials by setting the upper limit value and the lower limit value. Compared to the case where only iron is the main container, the container used for frying cooking using an electromagnetic cooker is used. The breadth of selection will be widened, and the usability of the electromagnetic cooker can be improved. Then, a control operation corresponding to the material is performed, and the oil can be controlled to have a predetermined temperature.

  Moreover, in the present invention, when the upper limit value and the lower limit value are set so that the range between the upper limit value and the lower limit value becomes an iron cooking container, a plurality of types of iron pans can be used within this range, Further, if it is in the upper region of the range, it becomes a cooking container made of SUS18-8, and if it is in the lower region, it becomes easy to determine that it becomes a cooking container made of SUS18-0. A control operation suitable for the cooking container can be performed.

It is a perspective view which shows the state which integrated the heating cooker which concerns on this invention in the kitchen equipment stand. It is a perspective view which shows the inside which removed the top plate of the heating cooker which concerns on this invention. It is an energization control circuit of the induction heating coil concerning the present invention. It is a flowchart of temperature determination control and material determination control of the cooking container (or pan) which concerns on this invention. It is a voltage-frequency relationship diagram in the cold start control of the temperature determination control and the material determination control of the cooking container (or pan) according to the present invention. FIG. 6 is a numerical relationship diagram of voltage and drive frequency for each type of cooking container (or pan) in FIG. 5. It is a relationship diagram of the voltage and frequency in the hot start control of the temperature determination control and the material determination control of the cooking container (or pan) according to the present invention. It is a numerical relationship figure of the voltage and drive frequency for every kind of cooking container (or pan) in FIG. It is a figure which shows the drive frequency of the cooking container (or pan) which concerns on this invention, (A) shows the drive frequency at the time of high input (at the time of 1500W input) using an iron pan, (B) shows the low of iron pan use The drive frequency at the time of input (at the time of 500W input) is shown. It is a figure which shows the state in which the drive frequency in the case of increasing the input of the cooking container (or pan) which concerns on this invention is reduced gradually. It is a figure which shows the change of the temperature of the oil in the iron pan 10cm in the cold start control of the material determination control of the cooking container (or pan) which concerns on this invention, and the detection temperature of pan bottom TH. It is a figure which shows the change of the temperature of the oil in the iron pan 22cm, and the detected temperature of the pan bottom TH in the cold start control of the material determination control of the cooking container (or pan) which concerns on this invention. It is a figure which shows the change of the temperature of the oil in the single layer pan of SUS18-8, and the detection temperature of pan bottom TH in the cold start control of the material determination control of the cooking container (or pan) which concerns on this invention. It is a figure which shows the change of the temperature of the oil in the pan of SUS18-0, and the detection temperature of pan bottom TH in the cold start control of the material determination control of the cooking container (or pan) which concerns on this invention. It is a flowchart which concerns on other embodiment of the temperature determination control and material determination control of the cooking container (or pan) which concerns on this invention.

  In the present invention, a switching element is provided to control energization to an exciting coil disposed under the top plate of the electromagnetic cooker body, and the driving circuit for driving the switching element and the control signal given to the driving circuit A control unit that controls the high-frequency power supplied to the exciting coil to approach the target power value; and a type determination unit that determines the type of the cooking container (or pan) placed on the top plate, the determination In an electromagnetic cooker configured to maintain the oil in the cooking container (or pan) at a predetermined heat-retaining temperature by control according to the type, the cooking container (or pan) is equal to or higher than a predetermined temperature or exceeds a predetermined temperature. Temperature determination means for determining whether or not the heating temperature is in a heated state, and when the temperature determination means determines that the heating coil is not in a heating state, energization of the exciting coil is performed in a high power state. And when the temperature determination means determines that the heating state is present, the determination is performed when the energization of the excitation coil is in a low power state so as to suppress the ignition of oil in the cooking container (or pan). Is to be executed.

  Embodiments of an electromagnetic cooker according to the present invention will be described below with reference to the drawings.

  Hereinafter, as an example of the present invention, an embodiment of an electromagnetic cooker 1 having one induction heating coil 4 and one radiant heater 5 will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a state in which the electromagnetic cooking device 1 according to the first embodiment of the present invention is attached to a kitchen equipment table 7. The electromagnetic cooker 1 is a form incorporated into the insertion hole of the upper surface plate 7A of the kitchen equipment table 7 such as a system kitchen, a cooking table or a sink, by a drop-in method, and a main body 2 that forms a substantially rectangular case. And a top plate 3 made of heat-resistant glass supported by a top plate frame 6 attached to the upper surface portion of the main body portion 2, and the main body portion 2 has a front and rear space in the lower space corresponding to the top plate 3. An induction heating coil 4 (hereinafter referred to as an excitation coil 4) and a radiant heater 5 are provided as heat sources that are installed at intervals. The main body 2 forms a substantially rectangular case having an upper surface opening by a side wall 2B attached to the bottom wall 2A so as to surround the bottom wall 2A and surrounding four sides. Moreover, the top plate 3 made of heat-resistant glass is in a state where the peripheral portion is supported by a top plate frame 6 attached to the side wall 2B with screws so as to cover the upper surface opening of the main body 2.

  A circular cooking container is placed on the top surface of the top plate 3 corresponding to the excitation coil 4 and the radiant heater 5 in order to clearly show the place where the cooking container 10 such as a pan (hereinafter referred to as the pan 10) is placed. Parts 8 and 9 are displayed by printing or the like. In the embodiment, the exciting coil 4 has a calorific value at a rated voltage of 200 V (volt) and a maximum input (or maximum input) of 1500 W (watt), and the radiant heater 5 has a rated voltage of 200 V and a maximum input (or rating). Input) Although it is a thing of the emitted-heat amount in 1200w, it is not limited to this.

  Below the upper surface plate 7A of the kitchen equipment table 7 (the sink 7) is an article storage space 12A, and the front surface of the article storage space 12A can be opened and closed by an open / close door. As described above, in the electromagnetic cooker 1 dropped into the insertion hole of the kitchen equipment stand 7, the bottom wall 2A of the main body 2 is exposed above the article storage space 12A.

  An excitation coil 4 and a radiant heater 5 are arranged in the main body 2. The excitation coil 4 is attached to the upper surface of a synthetic resin support frame 4A. The support frame 4A is supported by a synthetic resin base member 20 attached to the bottom wall 2A of the main body 2 by a coil spring, and the periphery of the support frame 4A. The flange is biased upward so that the flange contacts the lower surface of the heat-resistant glass top plate 3. As a result, the exciting coil 4 is held in a substantially horizontal state close to the lower surface of the top 3. Further, the radiant heater 5 is mounted in a heat-resistant support frame 5A having an opening on the upper surface, and the support frame 5A is supported by coil springs 19 at a plurality of locations on the upper surface of a support base 18 mounted so as to rise from the bottom wall 2A. The support frame 5A is urged upward so as to contact the lower surface of the top plate 3 made of heat-resistant glass. As a result, the radiant heater 5 is held in a substantially horizontal state in proximity to the lower surface of the top plate 3.

  The electromagnetic cooker 1 includes an operation switch unit 13 for performing energization control and heat generation control of the excitation coil 4 and the radiant heater 5, an LED display unit 14 corresponding to the operation switch unit 13, and the like at the front of the top frame 6. An operation unit 15 is provided. Further, a control device 30 constituting a control circuit unit for performing energization control and heat generation control of the exciting coil 4 and the radiant heater 5 and a heat radiation fin 27 of the control device 30 are mounted inside the main body 2. The printed wiring board 25 is attached to the upper surface of the synthetic resin base member 20. A cooling fan (not shown) for cooling the heat radiation fins 27 and cooling the exciting coil 4 and the radiant heater 5 is provided inside the main body 2, and the exhaust from the cooling fan is connected to the rear side wall. The air passes through the exhaust slit 28 formed in 2B and is discharged upward from the exhaust unit 16 formed in the rear part of the top frame 6. An exhaust cover 17 having a large number of exhaust holes 17A is attached to the exhaust portion 16. A control circuit unit for performing energization control and heat generation control of the exciting coil 4 and the radiant heater 5 and a printed wiring board 25 to which the heat dissipation fins 27 of the control circuit unit are attached are formed on the upper surface of the synthetic resin base member 20. It is attached.

  The excitation coil 4 attached to the upper surface of the support frame 4A is suitable for heating both the small and large ones of the bottom surface of the pan 10 placed on the top plate 3, The inner coil portion 4P and the outer coil portion 4Q that are connected in series are separately arranged concentrically.

  In order to mainly detect the heating state of the pot 10, a temperature detection sensor (hereinafter referred to as the pot bottom) that mainly detects the pot bottom temperature of the pot 10 is provided at the center of the inner coil portion 4 </ b> P so as to be positioned at the center of the exciting coil 4. TH). Further, a temperature detection sensor (hereinafter referred to as a coil TH) that mainly detects the temperature of the exciting coil 4 and the temperature of the bottom periphery of the pan 10 is disposed between the inner coil portion 4P and the outer coil portion 4Q.

  A control device 30 for electrically controlling the electromagnetic cooker 1 is shown in FIG. The control device 30 mainly includes a resonance circuit 32 having an excitation coil 4 and a resonance capacitor 31 connected in parallel thereto, a rectification circuit 34 that converts AC power supplied from a commercial power supply 33 into DC power, and a rectification circuit 34. In order to convert the DC power input from RF into high frequency power and supply it to the exciting coil 4, each of the inverter circuit 36 having switching elements 35A and 35B connected to the resonance circuit 32 and the switching elements 35A and 35B is switched. Drive circuits 37A and 37B for controlling the operation, and a control unit 38 for controlling the high frequency power supplied to the exciting coil 4 to be close to the target power value by changing the drive frequency of the control signal given to the drive circuits 37A and 37B. It has. In the embodiment, the AC power supplied from the commercial power source 33 is AC power having a rated voltage of 200 volts (hereinafter referred to as 200 V). In addition to this, the control device 30 also includes a control circuit unit that controls energization of the radiant heater 5.

  In addition to this, the control device 30 includes analog temperature values and voltage values of the temperature detection circuit 39, the current detection circuit 40, the voltage detection circuit 41, the current detection circuit 40, and the voltage detection circuit 41 based on the temperature detection of the pan bottom TH and the coil TH. Is converted to a digital value. The control unit 38 receives a switch operation signal from the operation unit 15, a signal from the temperature detection circuit 39, a signal from the A / D conversion circuit 42, and the like so as to play a central role in controlling the power of the excitation coil 4. The CPU 43 as a central processing unit, the ROM 44 that is a memory that stores an operation program executed by the CPU 43, the RAM 45 that is a memory that stores information for the CPU 43 to perform a control operation, and the like. The capacitor 31S is a snubber capacitor.

  The high frequency power supplied to the exciting coil 4 is input power calculated from the current value detected by the current detection circuit 40 and the voltage value detected by the voltage detection circuit 41, and this is the output power of the electromagnetic cooker 1. (For example, the maximum output is 1500 W). This input can be controlled by controlling the switching time by ON-OFF of the switching elements 35A and 35B by the drive circuits 37A and 37B.

  When the input time is controlled by controlling the switching time by ON / OFF of the switching elements 35A, 35B by the drive circuits 37A, 37B, the energization time to the exciting coil 4 by lowering the drive frequency as shown in FIG. The input is increased if the length is increased, and the input is decreased if the drive frequency is increased and the energization time to the exciting coil 4 is shortened as shown in FIG. For this reason, in order to set the high-frequency power supplied to the exciting coil 5 to a high input 1500 W, the switching elements 35A and 35B are controlled to be turned on and off at a low frequency corresponding to that as shown in FIG. 9A. do it. Further, in order to set the high frequency power supplied to the exciting coil 5 to a low input of 500 W, the switching elements 35A and 35B are controlled to be turned on and off at a high frequency corresponding to that as shown in FIG. 9B. That's fine.

  A control method for variably controlling the drive frequency so as to achieve a predetermined target power value will be described. FIG. 10 is an explanatory diagram when the drive frequency is gradually lowered when heating to a predetermined target power value. In FIG. 10, if the target power value is 1500 W, for example, when the exciting coil 4 is driven at a certain driving frequency (indicated by (1) KHz), it is checked whether or not the input is 1500 W. If 1500 W is not output, the excitation coil 4 is driven at a predetermined drive frequency (indicated by (2) KHz) lower than that to check whether the input is 1500 W. Here, if 1500 W is not yet output, the exciting coil 4 is driven at a predetermined drive frequency (indicated by (3) KHz) lower than that to check whether the input is 1500 W. In this way, the drive frequency is changed so that the input is 1500 W. It should be noted that Ta1: Tb1 = Ta2: Tb2 = Ta3: Tb3 = 1. In the description of FIG. 10 and FIG. 10, ((1) KHz) and ((2) KHz) do not indicate 1 KHz and 2 KHz. In (1) and (2), some numerical value such as 200 or 100 is entered.

  More specifically, when the deep-fried food cooking is started by operating the deep-fried food switch 13B in the state where the target power value is set to 1500 W in the electromagnetic cooker 1, the controller 38 first heats at 1500 W. Start and divide 1500 W by the voltage value detected by the voltage detection circuit 41 at a predetermined time interval to obtain a current value I1 at that time, and divide this I1 by the set value I0 to obtain a calculated value at that time x1 is calculated, and the exciting coil 4 is driven at a driving frequency f1 corresponding to x1. Similarly, at a predetermined time interval, 1500 W is divided by the voltage value detected by the voltage detection circuit 41 to obtain a current value I2 at that time, and this I2 is divided by the set value I0 to obtain the current value. A calculated value x2 is calculated, and the exciting coil 4 is driven at a drive frequency f2 corresponding to x2. With this relationship, the excitation coil 4 is driven with the drive frequencies f1, f2, f3... Corresponding to the calculated values x1, x2, x3... And controlled until the target power value reaches 1500 W. The In this control, a table indicating the correspondence between the calculated values x1, x2, x3... And the drive frequencies f1, f2, f3... Is set in the ROM 44 or RAM 45.

  For example, in the control for reducing the input to 500 W when heating at 1500 W, similarly to the above, the drive frequencies f1, f2, f3 corresponding to the calculated values x1, x2, x3. Depending on the relationship, the excitation coil 4 is driven while gradually increasing the drive frequency, and it is checked whether or not 500 W has been output. If 500 W has not yet been output, the excitation coil has a higher predetermined drive frequency. 4 is driven, and control is performed until the target power value reaches 500 W by checking whether or not the input is 500 W again.

  As shown in FIG. 10, the waveforms of the drive frequencies for performing the ON / OFF control of the switching elements 35 </ b> A and 35 </ b> B are opposite in ON / OFF timing. Then, in order to prevent a large current from flowing at the time of ON-OFF switching and destroying the switching elements 35A and 35B, an operation with a certain switching time difference as shown in d is performed. .

  The target power value is usually referred to as an input of the electromagnetic cooker 1, and in the embodiment, when the rated voltage of the AC power supplied from the commercial power supply 43 is 200V, the maximum value of the electromagnetic cooker 1 is set. The maximum input, which is the target power value, is 1500 watts (hereinafter referred to as 1500 W).

  When the pan 10 filled with oil is placed in the electromagnetic cooker 1 and heating is started by the excitation coil 4 with a certain input, the temperature detected by the pan bottom TH when the pan 10 is made of iron, and pans of other materials The temperature detected by the pan bottom TH when used is different. Since the temperature rise of the pan 10 varies depending on the heating, the temperature detected by the pan bottom TH varies depending on the material of the pan 10, and the temperature of the oil placed in the pan 10 deviates from a predetermined heat retention temperature. For this reason, it is necessary to carry out appropriate heating control for maintaining the oil at a predetermined heat-retaining temperature depending on what kind of material the pan 10 is made of. In this regard, even when a plurality of types of pans 10 are used, the energization control of the exciting coil 4 is performed so as to determine the material of the pan 10 and to output a predetermined rated input, thereby maintaining the oil at a predetermined temperature. Therefore, a technique for determining the material of the pan 10 placed on the electromagnetic cooker 1 is provided. This technique is described below.

  In the present invention, an operation is performed to start heating in a state where a pan 10 containing a predetermined amount of oil (500 g oil amount in the embodiment) is placed on the top surface of the top plate 3 corresponding to the excitation coil 4. The power switch 13A, which is one of the operation switch sections 13 provided in the section 15, is operated to be turned on. In this state, the deep-fried food switch 13B is operated, the control unit 38 operates based on the ON signal, and the CPU 43 executes the processing operation according to the operation program stored in the ROM 44.

  Thus, the deep-fried food switch 13B is operated and the control part 38 operate | moves based on the ON signal. Thereby, the heating of the pan 10 is started, and the oil therein is heated. Within a predetermined time (within 40 seconds in the embodiment) from this start, the material determination of the pan 10 is performed. This material determination will be described based on the flowchart of FIG. 4 and FIGS. 5 to 8 showing the relationship between the material of the pan 10 and the driving frequency. The flowcharts shown in FIG. 4 and FIG. 15 show the steps of the processing operation executed by the CPU 43 in accordance with the operation program stored in the ROM 44. The temperature determination by each temperature determination means and the material determination for determining the material of the pan 10 Each determination means such as means means an operation unit executed for each step shown in FIGS. 4 and 15 as the processing operation of the CPU 23.

  In the present invention, when the temperature of the pan 10 containing a predetermined amount of oil (500 g oil amount in the embodiment) at the start of frying is high to some extent, if the pan 10 is heated at a high input, there is a risk of ignition. It has a configuration with safety means to prevent. For this reason, the determination step which performs the determination whether the pan 10 mounted in the cooking container mounting part 8 is already heated is provided. Hereinafter, the determination operation when this temperature determination means is provided will be described.

  Specifically, with the pan 10 containing a predetermined amount (for example, 500 g) of oil placed on the cooking vessel placing portion 8, the power switch 13A is operated to the ON state, and the control device 30 operates. The ready state is entered, and the CPU 43 can execute the processing operation according to the operation program stored in the ROM 44. Then, the fried food switch 13B is turned on as a frying start (step S1 in FIG. 4), whereby the CPU 23 executes a processing operation.

  In this invention, the determination step which determines first whether the pan 10 mounted in the cooking container mounting part 8 is already heated is provided. For this reason, the temperature detection of the pan 10 placed on the cooking container placement unit 8 is performed by the pan bottom TH, and temperature data based on the detection is input from the temperature detection circuit 39, and the pan 10 is brought to a predetermined temperature in accordance with the operation of the CPU 43. Whether it is heated or not is determined by the temperature determining means (step S2 in FIG. 4). In the embodiment, it is determined in step S2 whether the detected temperature of the pan bottom TH is 60 ° C. or lower, and if the detected temperature is 60 ° C. or lower (YES), the pan 10 is cold. As shown in FIG. For this reason, when oil is heated to a predetermined heat-retaining temperature of 180 ° C. so that the temperature is suitable for fried food, there is no risk of ignition even if the pan 10 is heated at a high input, so a constant high input 1500 W Then, the process proceeds to the step of heating the pan 10 (step S3 in FIG. 4).

  Then, by the operation of the control unit 38, the constant input power calculated based on the current value detected by the current detection circuit 40 and the voltage value detected by the voltage detection circuit 41 is supplied to the exciting coil 4 and heating is started. (Step S3 in FIG. 4). In step S3, the inverter circuit 16 is controlled by varying the drive frequency applied to the drive circuits 17A and 17B so that the high-frequency power supplied to the exciting coil 4 becomes an input 1500 W that is a target power value. As described above with reference to FIG. 10, this variable control of the driving frequency drives the exciting coil 4 with the driving frequencies f1, f2, f3... Corresponding to the calculated values x1, x2, x3. Thus, control is performed so as to obtain a predetermined target power value. In this state, if the driving frequency at that time is checked, the material of the pan 10 currently used can be determined.

  The present invention applies this technical idea so that three types of pots 10 can be used. Hereinafter, the determination means will be described.

  In the present invention, it is determined whether or not a first predetermined time (for example, 20 seconds) has elapsed from the start of heating at 1500 W (step S3) in order to stably determine the material of the pan 10 (FIG. 4). Step S4) When 20 seconds have elapsed (YES), the first frequency determination means starts checking (measuring) the drive frequency (Step S5 in FIG. 4). The circuit configuration in which the CPU 43 executes the processing operation is provided with first frequency detection means for detecting the drive frequency of the control signal (PWM signal) to be supplied to the drive circuit 37, whereby the drive frequency is checked.

  Then, it is determined whether or not a second predetermined time (for example, 40 seconds) longer than the first predetermined time has elapsed since the start of heating at 1500 W (step S6 in FIG. 4). The process proceeds to step S7 and subsequent steps in FIG. For this reason, the material of the pot 10 is determined by the material determination means from step S7 to step 11 in FIG. 4 according to the driving frequency checked between the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds). It means to judge.

  As described above, in the present invention, when the drive frequency of the control signal exceeds the predetermined upper limit value A or exceeds the predetermined upper limit value A in step S7 and step S8 of FIG. (In this case, the pan 10 made of SUS18-8) is determined (step S9 in FIG. 4). When the predetermined lower limit B or less or less than the predetermined lower limit B, the second type of pan 10 (here, SUS18). -0 made pan 10) (step S10 in FIG. 4), and if it is within the range between the upper limit value A and the lower limit value B, the third type material pan 10 (here, iron pan 10) Determination (step S11 in FIG. 4) includes material determination means (also referred to as type determination means). This determination is performed by a material determination unit configured by the control unit 30.

  If the determination by this material determination means is demonstrated in detail, in step S7 and step S8 of FIG. 4, the material of the pot 10 will be determined by whether the drive frequency of the control signal is higher or lower than a predetermined upper limit value A. First determining means (step S7 in FIG. 4) and second determining means (step S8 in FIG. 4) for determining the material of the pan 10 depending on whether it is higher or lower than the predetermined lower limit B. Based on the determination of the first and second determination means within a predetermined time from the start of control in a constant input state by the control unit 30, the control unit 30 adapts to the material of the pan 10 so as to maintain the oil at a predetermined heat insulation temperature. The heating control operation is performed (step S13 in FIG. 4).

  More specifically, in step S7 and step S8 in FIG. 4, it is determined whether or not the drive frequency of the control signal is equal to or higher than a predetermined upper limit value A or exceeds a predetermined upper limit value A. First determination means (steps S7 and S9 in FIG. 4) for determining that the pan 10 is a first type of material (here, pan 10 made of SUS18-8) when A exceeds A or a predetermined upper limit A. Second determination means (step S8 in FIG. 4 and step S8 in FIG. 4) that determines that the pan is made of the second type of material (here, pan 10 made of SUS18-0) when it is less than or equal to the predetermined lower limit B S10) and third determination means (step S7 in FIG. 4) for determining that the pot is a third type of pot 10 (here, iron pot 10) if it is within the range between the upper limit value A and the lower limit value B. S8 and S11), and the control unit 30 Based on the determination of the first to third means within a predetermined time from the start of control in a constant input state, the control unit 30 then controls the heating according to the type of the pan 10 so as to maintain the oil at a predetermined temperature. The operation is performed (step S13 in FIG. 4). Note that step S12 in FIG. 4 is another processing step (for example, oil amount measurement, etc.) that is executed in the process of shifting to step S13 after the above material determination is completed.

  In an Example, the iron pan 10, the SUS18-0 pan 10, and the SUS18-8 pan 10 are set as the applicable pan 10, In that case, within the range of the upper limit A and the lower limit B If the upper limit value A and the lower limit value B are set so that the iron pan 10 is obtained, the pan 10 made of SUS18-8 is formed in the upper region, and the pan 10 made of SUS18-0 is formed in the lower region. Judgment can be made easily. That is, the SUS18-8 pan 10 has a higher drive frequency than the frequency determination range of the iron pan 10 that is the range between the upper limit A and the lower limit B (described as the frequency iron determination range in FIG. 4). Since the SUS18-0 pan 10 has a lower driving frequency than the iron pan 10, in steps S7 and S8 in FIG. 4, the determination is based on the iron pan 10 or the SUS18-0 pan. It is the structure which determines whether it is the pan 10 or the SUS18-8 pan 10. This is substantially the same as the case where the determination is made by comparing the upper limit value A (reference value upper limit A) and the lower limit value B (reference value lower limit B) as described above.

  As described above, during a second predetermined time (for example, 40 seconds) from the start of heating, heating is performed at a constant input 1500 W in the case of a cold start, and heating is performed at a constant input 500 W in the case of a hot start, during the first predetermined time. The material of the pot 10 is determined by the material determination means from step S5 to step 11 in FIG. 4 based on the driving frequency checked between (for example, 20 seconds) and the second predetermined time (for example, 40 seconds). Thus, when the oil is started to be heated to a predetermined temperature of 180 ° C., the material judgment of the pan 10 is performed. The oil is not yet heated to the predetermined temperature of 180 ° C. This is because a phenomenon in which the value of the drive frequency for maintaining the temperature varies depending on the material of the pan 10 can be accurately captured.

  5 and 6 show the relationship of the drive frequency to the power supply voltage (voltage rectified by the rectifier circuit 34) detected by the voltage detection circuit 41 for each type of pan 10 when heating is started at 1500W. ing. As shown in FIG. 5, when the reference power supply voltage is 200V, the power supply voltage has two types of iron pans so that regular material determination can be performed even when the power supply voltage fluctuates within a range of ± 20V. 10, the upper limit A and the lower limit B for setting the SUS18-0 pan 10 and the SUS18-8 pan 10 as the applicable pan 10 are set in the ROM 44 or the RAM 45.

  As shown in FIG. 5, when the power supply voltage is 200 V, the upper limit value A of the drive frequency (described as the reference value upper limit A in FIG. 6) in the material determination is 26.3 KHz, and the lower limit value B of the drive frequency. (Described as reference value lower limit B in FIG. 6) is 23.4 KHz. When the power supply voltage is in the range of 180 V to 220 V, the upper limit value A of the drive frequency is the value indicated by the graph G1, and the lower limit value B of the drive frequency is the value indicated by the graph G2. As is apparent from FIG. 5, the range of the graph G1 and the graph G2 is the iron pan 10 which is the third type of pan 10, and the one of the first type of pan which is equal to or higher than the graph G1. It is the pan 10 made from SUS18-8 which is 10, and the thing below the graph G2 or less shows that it is the pan 10 made from SUS18-0 which is the 2nd kind of pan 10.

  For this reason, the graph G3 shown in FIG. 5 is one kind of commercially available iron fried pan 10 having a bottom diameter of 10 cm, and the graph G4 is an iron fried pan 10 prepared for exclusive use of the electromagnetic cooker 1 of the embodiment. This is an iron fried pan 10 made of iron having a bottom diameter of 22 cm. Moreover, the graph G5 shown in FIG. 5 is one of the SUS18-8-made pans 10 with a bottom diameter of 18 cm, and the graph G6 is one of the SUS18-0-made pans 10.

  6, among the graph values shown in FIG. 5, the upper limit value A (reference value upper limit A), the lower limit value B (reference value lower limit B) when the power supply voltage is 180 V, 200 V, and 220 V, G3: commercially available iron The driving frequency of the frying pan 10, G4: the driving frequency of the iron fried pan 10 made of iron, G5: the driving frequency of the pan 10 made of SUS18-8, and G6: the driving frequency of the pan 10 made of SUS18-0 are shown.

  Thus, if the upper limit A and the lower limit B are within this range, the value determined so that many iron pans can be used in consideration of the size and material of the iron pan suitable for normal use. It is. For this reason, the frequency range between the upper limit value A and the lower limit value B can be referred to as an iron determination range as described in step S7 in FIG. It can be said that the SUS18-8 pan 10 is above or beyond this range, and the SUS18-0 pan 10 is below or below this range.

  After determining the material of the pan 10 as described above, for example, it is determined that the pan 10 is made of iron, for example, in step S13, a predetermined heat retaining temperature 180 suitable for fried food (tempura or fried food) according to the characteristics of the pan 10 is obtained. The oil temperature is controlled to be ℃. For this reason, the CPU 43 operates via the temperature detection circuit 39 and the A / D conversion circuit 42 by a signal based on the temperature detection of the pan bottom TH, and the inverter circuit 16 is controlled by changing the drive frequency applied to the drive circuits 17A and 17B. Control. The variable control of the driving frequency is performed by a driving circuit based on a driving frequency determined by comparing data based on temperature detection of the pan bottom TH with reference data (table data set in the ROM 44 or RAM 45) determined for each material of the pan 10. 17A and 17B operate, and the inverter circuit 16 is controlled so that the oil temperature is controlled to a predetermined heat retention temperature of 180 ° C.

  In addition, when it transfers to step S13 and the heating control operation | movement according to the kind of pan 10 is performed by the control part 30 so that oil may be maintained to predetermined | prescribed heat retention temperature, the pan 10 heats efficiently by supplying with electricity to the exciting coil 4 In order to achieve the state, the inverter circuit 36 can be driven at a drive frequency set based on the resonance frequency of the resonance circuit 32. Usually, the driving frequency at this time is substantially the same as the resonance frequency or a slightly higher frequency.

  In the above, it is determined in step S2 in FIG. 4 whether the detected temperature of the pan bottom TH is 60 ° C. or lower, and if the detected temperature is 60 ° C. or lower (YES), the detected temperature is 60 ° C. or lower. The case where it is not less than (NO) will be described below. In this case, the pan 10 is warmed, and the hot start control is performed as shown in FIG.

  In the embodiment, it is determined in step S2 of FIG. 4 whether the detected temperature of the pan bottom TH is 60 ° C. or less. If the detected temperature is not less than 60 ° C. (NO), a constant low input (500 W in the embodiment) is determined. ) To heat the pan 10 (step S31 in FIG. 4). This is a state in which the pan 10 is warmed, so if heated to a predetermined heat-retaining temperature (180 ° C. in the embodiment) that is suitable for deep-fried food, the temperature of the oil in the pan 10 will rise rapidly. Since there is a risk of fire, the process proceeds to the step of heating the pan 10 with a constant low input (500 W in the embodiment) (step S31 in FIG. 4).

  By the operation of the control unit 38, the constant input power calculated based on the current value detected by the current detection circuit 40 and the voltage value detected by the voltage detection circuit 41 is supplied to the exciting coil 4 and heating starts ( Step S31 in FIG. In step S31, the inverter circuit 16 is controlled by varying the drive frequency applied to the drive circuits 17A and 17B so that the high-frequency power supplied to the excitation coil 4 becomes an input 500 W that is the target power value. As described above with reference to FIG. 10, this variable control of the drive frequency drives the exciting coil 4 with the drive frequencies f11, f22, f33... Corresponding to the calculated values x11, x22, x33. Thus, control is performed so as to obtain a predetermined target power value. In this state, if the driving frequency at that time is checked, the material of the pan 10 currently used can be determined.

  The present invention applies this technical idea so that three types of pots 10 can be used. Hereinafter, the determination means will be described.

  In the present invention, it is determined whether or not a first predetermined time (for example, 20 seconds) has elapsed since the start of heating at 500 W (step S31) in order to make the material determination of the pan 10 stable (FIG. 4). Step S41) When 20 seconds have passed (YES), the first frequency determination means starts checking (measuring) the drive frequency (Step S51 in FIG. 4). The circuit configuration in which the CPU 43 executes the processing operation is provided with first frequency detection means for detecting the drive frequency of the control signal (PWM signal) to be supplied to the drive circuit 37, whereby the drive frequency is checked.

  Then, it is determined whether or not a second predetermined time (for example, 40 seconds) longer than the first predetermined time has elapsed since the start of heating at 500 W (step S61 in FIG. 4), and the material determination is made when 40 seconds have elapsed (YES). It shifts to the step after step S71 of Drawing 4 which judges the material of pot 10 by means. For this reason, the material of the pot 10 is determined by the material determination means from step S71 to step S111 in FIG. 4 according to the driving frequency checked between the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds). It means to judge.

  As described above, in the present invention, when the drive frequency of the control signal exceeds the predetermined upper limit value A or exceeds the predetermined upper limit value A in step S71 and step S81 of FIG. (Here, the pan 10 made of SUS18-8) is determined (step S91 in FIG. 4). When the predetermined lower limit B or less or less than the predetermined lower limit B, the second type of pan 10 (here, SUS18). -0 made pan 10) (step S101 in FIG. 4), and if it is within the range between the upper limit value A and the lower limit value B, a third type of material pan 10 (here, iron pan 10) Material determining means for determining (step S111 in FIG. 4) is provided. This determination is performed by a material determination unit configured by the control unit 30.

  If the determination by this material determination means is demonstrated in detail, in step S71 and step S81 of FIG. 4, the material of the pan 10 will be determined by whether the drive frequency of the control signal is higher or lower than a predetermined upper limit C. First determination means (step S71 in FIG. 4) and second determination means (step S81 in FIG. 4) for determining the material of the pan 10 depending on whether it is higher or lower than the predetermined lower limit D. Based on the determination of the first and second determination means within a predetermined time from the start of control in a constant input state by the control unit 30, the control unit 30 adapts to the material of the pan 10 so as to maintain the oil at a predetermined heat insulation temperature. The heating control operation is performed (step S13 in FIG. 4).

  More specifically, in step S71 and step S81 in FIG. 4, it is determined whether or not the drive frequency of the control signal is equal to or higher than a predetermined upper limit value C or exceeds a predetermined upper limit value C. First determination means (steps S71 and S91 in FIG. 4) for determining that the pan is made of the first type of material (here, the pan 10 made of SUS18-8) when C exceeds or exceeds a predetermined upper limit C; Second determination means (step S81 in FIG. 4 and step S81 in FIG. 4) that determines that the pan 10 is a second type of material (here, pan 10 made of SUS18-0) when it is less than or equal to the predetermined lower limit D or less than the predetermined lower limit D. S101) and third determination means (step S71 in FIG. 4) for determining that the pot is a third type of pot 10 (here, iron pot 10) if it is within the range between the upper limit C and the lower limit D. S81 and S111) Based on the determination of the first to third means within a predetermined time from the start of control in a constant input state by the control unit 30, the control unit 30 then selects the type of the pan 10 so as to maintain the oil at a predetermined temperature. The heating control operation corresponding to is performed (step S13 in FIG. 4). Note that step S12 in FIG. 4 is another processing step (for example, oil amount measurement, etc.) that is executed in the process of shifting to step S13 after the above material determination is completed. In addition, the control performed in step S13 of FIG. 4 is controlled so that the temperature of the oil becomes a predetermined heat retention temperature of 180 ° C. by the same control method as described in the cold start control.

  In an Example, the iron pan 10, the SUS18-0 pan 10, and the SUS18-8 pan 10 are set as the applicable pan 10, In that case, within the range of the upper limit C and the lower limit D If the upper limit value C and the lower limit value D are set so as to become the iron pot 10, it becomes a SUS18-8 pot 10 if it is in the upper area, and it becomes a SUS18-0 pot 10 if it is in the lower area. Judgment can be made easily. That is, the SUS18-8 pan 10 has a higher driving frequency than the frequency determination range of the iron pan 10 that is the range between the upper limit C and the lower limit D (described as the frequency iron determination range in FIG. 4). Since the SUS18-0 pan 10 has a lower driving frequency than the pan 10, in steps S71 and S81 of FIG. 4, the iron pan 10 or SUS18-0 is made based on the determination based on the iron pan 10. It is the structure which determines whether it is the pan 10 or the pan 10 made from SUS18-8. This is substantially the same as the case where the determination is made by comparing the upper limit value C (reference value upper limit C) and the lower limit value D (reference value lower limit D) as described above.

  As described above, during a second predetermined time (for example, 40 seconds) from the start of heating, heating is performed at a constant input 1500 W in the case of a cold start, and heating is performed at a constant input 500 W in the case of a hot start, during the first predetermined time. The material of the pan 10 is determined by the material determination means from step S7 to step S11 in FIG. 4 according to the driving frequency checked during a second predetermined time (for example, 40 seconds) from (for example, 20 seconds). Thus, when the oil is started to be heated to a predetermined temperature of 180 ° C., the material judgment of the pan 10 is performed. The oil is not yet heated to the predetermined temperature of 180 ° C. This is because a phenomenon in which the value of the drive frequency for maintaining the temperature varies depending on the material of the pan 10 can be accurately captured.

  7 and 8 show the relationship of the drive frequency to the power supply voltage (voltage rectified by the rectifier circuit 34) detected by the voltage detection circuit 41 for each type of pan 10 when heating is started at 500W. ing. As shown in FIG. 7, when the reference power supply voltage is set to 200V, the power supply voltage has two types of iron pans so that regular material determination can be performed even when the power supply voltage fluctuates within a range of ± 20V. 10, the upper limit C and the lower limit D for making the SUS18-0 pan 10 and the SUS18-8 pan 10 the applicable pan 10 are set in the ROM 44 or the RAM 45.

  As shown in FIG. 7, when the power supply voltage is 200 V, the upper limit C of the drive frequency (described as the reference value upper limit C in FIG. 8) in the material determination is 34.58 KHz, and the lower limit D of the drive frequency. (Described as a reference value lower limit D in FIG. 8) is 30.71 KHz. When the power supply voltage is in the range of 180 V to 220 V, the upper limit value C of the drive frequency is the value indicated by the graph G11, and the lower limit value D of the drive frequency is the value indicated by the graph G21. As apparent from FIG. 7, the range of the graph G11 and the graph G21 is the iron pan 10 that is the third type of pan 10, and the range of the first type pan is greater than or equal to the graph G11. It is the pan 10 made from SUS18-8 which is 10, and the thing below the graph G21 or less shows that it is the pan 10 made from SUS18-0 which is the second kind of pan 10.

  For this reason, the graph G31 shown in FIG. 7 is one type of a commercially available iron fried pan 10 having a bottom diameter of 10 cm, and the graph G41 is an iron fried pan 10 prepared for exclusive use of the electromagnetic cooker 1 of the embodiment. This is an iron fried pan 10 made of iron having a bottom diameter of 22 cm. Moreover, the graph G51 shown in FIG. 7 is one of the SUS18-8-made pans 10 with a bottom diameter of 18 cm, and the graph G61 is one of the SUS18-0-made pans 10.

  8, among the graph values shown in FIG. 7, the upper limit value C (reference value upper limit C), the lower limit value D (reference value lower limit D) when the power supply voltage is 180 V, 200 V, and 220 V, G31: commercially available iron The driving frequency of the frying pan 10, G41: the driving frequency of the iron fried pan 10 made of iron, G51: the driving frequency of the pan 10 made of SUS18-8, and the driving frequency of the pan 10 made of G61: SUS18-0 are shown.

  Thus, if the setting of the upper limit C and the lower limit D is within this range, a value determined so that many iron pans can be used, considering the size and material of the iron pan suitable for normal use. It is. For this reason, the frequency range between the upper limit C and the lower limit D can be referred to as an iron determination range as described in Step 71 of FIG. 4, and the one in this range is the iron frying pan 10. It can be said that the SUS18-8 pan 10 is above or beyond this range, and the SUS18-0 pan 10 is below or below this range.

  As described above, in the present invention, the cooking container 10 of the first type material is a cooking container made of SUS18-8, the cooking container 10 of the second type material is a cooking container made of SUS18-0, The case where the cooking container 10 of three types of materials is an iron cooking container is taken as an example.

  As described above, in the present invention, the voltage at which the energization to the exciting coil 4 is controlled by the switching elements 35A and 35B is a DC voltage obtained by passing the voltage of the commercial AC power supply 33 through the rectifier circuit 34. The upper limit value A or C and the lower limit value B or D are set according to the driving frequency of the control signal for various values. And in FIG. 4, this upper limit and lower limit are shown in the state which is the range of the cooking container 10 made from iron.

  As described above, after the material of the pan 10 is determined, the control unit 30 performs a heating control operation according to the type of the pan 10 so as to maintain the oil in the pan 10 at a predetermined heat retaining temperature (for example, 180 ° C.). (Step S13 in FIG. 4). Step S12 in FIG. 4 is another processing step (for example, oil amount measurement or the like) executed in the process of moving to step S13 after the above material determination and size determination are completed.

  FIG. 15 shows a flowchart of temperature determination control and material determination control as another embodiment according to the present invention. Below, it demonstrates based on the control flow of FIG.

  In FIG. 15, with the pan 10 containing a predetermined amount of oil placed on the cooking container placing portion 8, the power switch 13 A is operated to the ON (on) state, the control device 30 enters the operating state, and the ROM 44 In accordance with the stored operation program, the CPU 43 enters a state for executing the processing operation. When the deep-fried food switch 13B is turned on as a frying start (step S11 in FIG. 15), the temperature of the pan 10 is detected by the pan bottom TH, and temperature data based on the temperature detection is input from the temperature detection circuit 39. Whether the pan 10 is heated to a predetermined temperature in accordance with the operation of the CPU 43 is determined by the temperature determining means (step S22 in FIG. 15). In the embodiment, it is determined in step 22 whether the detected temperature of the pan bottom TH is 60 ° C. or higher. If the detected temperature is 60 ° C. or higher (YES), the pan 10 is warm, as in FIG. The hot start control is performed, and the process proceeds to step S331, and heating at a constant low input 500W is started as in FIG.

  And in order to make it the state which can perform the material determination of the pan 10 stably, it is determined whether the 1st predetermined time (for example, 20 seconds) passed from the heating start at 500 W (step S441 of FIG. 15), 20 When the second has passed (YES), the first frequency determination means starts checking (measuring) the drive frequency (step S551 in FIG. 15). The circuit configuration in which the CPU 43 executes the processing operation is provided with first frequency detection means for detecting the drive frequency of the control signal (PWM signal) to be supplied to the drive circuit 37, whereby the drive frequency is checked.

  Then, it is determined whether or not a second predetermined time (for example, 40 seconds) longer than the first predetermined time has elapsed from the start of heating at 500 W (step S661 in FIG. 15), and when 40 seconds have elapsed (YES), the material determining means Thus, the process proceeds to step S77 and subsequent steps in FIG. The provision of the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds) is driven between the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds). The frequency is checked, and the material of the pan 10 is determined by comparing the drive frequency with a reference value. The oil has not yet been heated to a predetermined temperature of 180 ° C., and at the beginning of heating the oil By determining the material of the pot 10, the heating is controlled in a state commensurate with the material of the pot 10.

  In step S77 and step S88 of FIG. 15, when the drive frequency of the control signal exceeds the predetermined upper limit value A or exceeds the predetermined upper limit value A, the pan 10 of the first type material (here, made of SUS18-8). Pan 10) (step S99 in FIG. 15), and when it is less than or equal to the predetermined lower limit B or less than the predetermined lower limit B, the second type of pot 10 (here, pan 10 made of SUS18-0) If it is determined (step S1010 in FIG. 15) and is within the range between the upper limit value A and the lower limit value B, it is determined that the pot is a third type of pot 10 (here, iron pot 10) (step S1111 in FIG. 15). ) It has a judging means. This determination is performed by the determination unit configured by the control unit 30 and is the same as that described in FIG.

  Based on the determination by the determination means within a predetermined time from the start of control in a constant input state by the control unit 30, the control unit 30 then determines the type of the pot 10 determined so as to maintain the oil at a predetermined temperature. The heating control operation corresponding to is performed (step S13 in FIG. 15). Note that step S12 in FIG. 15 is the same as step 12 in FIG. 4. After the above-described material determination is completed, other steps executed in the process of moving to step S13 in FIG. 15 similar to step S13 in FIG. It is a processing step (for example, oil amount measurement). The control performed in step S13 in FIG. 15 is controlled so that the temperature of the oil becomes a predetermined heat retention temperature of 180 ° C. by the same control method as described in the cold start control.

  On the other hand, in step 22, it is determined whether the detected temperature of the pan bottom TH is 60 ° C. or higher. If the detected temperature is 60 ° C. or lower (NO), the pan 10 is cold, as in FIG. Cold start control. For this reason, when oil is heated to a predetermined heat retention temperature of 180 ° C. so that the temperature is suitable for fried food, there is no risk of ignition even if the pan 10 is heated at a high input. The pan 10 is heated with a high input 1500 W (step S33 in FIG. 15).

  And in order to make it the state which can perform the material determination of the pan 10 stably, it is determined whether the 1st predetermined time (for example, 20 seconds) passed since the heating start at 1500 W (step S44 of FIG. 15), 20 When the second has passed (YES), the first frequency determination means starts checking (measuring) the drive frequency (step S55 in FIG. 15). The circuit configuration in which the CPU 43 executes the processing operation is provided with first frequency detection means for detecting the drive frequency of the control signal (PWM signal) to be supplied to the drive circuit 37, whereby the drive frequency is checked.

  Then, it is determined whether or not a second predetermined time (for example, 40 seconds) longer than the first predetermined time has elapsed since the start of heating at 1500 W (step S66 in FIG. 15), and when 40 seconds have elapsed (YES), the material determination It moves to the step after step S77 of Drawing 15 which judges the material of pot 10 by means. The provision of the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds) is shown in the figure between the first predetermined time (for example, 20 seconds) and the second predetermined time (for example, 40 seconds). This means that the material of the pot 10 is determined by the material determination means from step S77 to step 1111.

  In step S77 and step S88 of FIG. 15, when the drive frequency of the control signal exceeds the predetermined upper limit value A or exceeds the predetermined upper limit value A, the pan 10 of the first type material (here, made of SUS18-8). Pan 10) (step S99 in FIG. 15), and when it is less than or equal to the predetermined lower limit B or less than the predetermined lower limit B, the second type of pot 10 (here, pan 10 made of SUS18-0) If it is determined (step S1010 in FIG. 15) and is within the range between the upper limit value A and the lower limit value B, it is determined that the pot is a third type of pot 10 (here, iron pot 10) (step S1111 in FIG. 15). ) It has a judging means. This determination is performed by the determination unit configured by the control unit 30 and is the same as that described in FIG.

  Based on the determination by the determination means within a predetermined time from the start of control in a constant input state by the control unit 30, the control unit 30 then determines the type of the pot 10 determined so as to maintain the oil at a predetermined temperature. The heating control operation corresponding to is performed (step S13 in FIG. 15). Note that step S12 in FIG. 15 is the same as step 12 in FIG. 4. After the above-described material determination is completed, other steps executed in the process of moving to step S13 in FIG. 15 similar to step S13 in FIG. It is a processing step (for example, oil amount measurement). The control performed in step S13 in FIG. 15 is controlled so that the temperature of the oil becomes a predetermined heat retention temperature of 180 ° C. by the same control method as described in the cold start control.

  4 and 15 are flow charts of temperature determination control and material determination control according to the present invention. However, within the technical scope of the present invention, other steps configured by steps different from the steps of FIGS. It may be a control flowchart.

  Moreover, although the kind of pan determined by the type determination means according to the present invention is the material determination of the pan in the above embodiment, this is possible even when the energization to the exciting coil is in a low power state such as 500 W. This is because the type determination can be performed accurately. However, in order to achieve the object of the present invention, the type of the pot determined by the type determining means is not only the material of the pot, but also a method for discriminating other distinguishable elements within the technical scope of the present invention. is there.

  The electromagnetic cooker according to the present invention is not limited to the configuration shown in the above embodiment, but can be applied to various forms, and includes various forms within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic cooker 2 ... Main part 2A ... Bottom wall of main part 3 ... Top plate 4 ... Induction heating coil (excitation coil)
5 ... Lagent heater 6 ... Top frame 7 ... Kitchen equipment stand (sink)
7A ... Top plate 8, 9 ... Cooking container placement part 10 ... Cooking container (pot)
13 ... Operation switch part 13A ... Power switch 13B ... Fried food switch 16 ... Exhaust part 17 ... Exhaust cover 19 ... Coil spring 20 ... Base member 21 ... .... Coil spring 25 ... Circuit board 27 ... Radiation member 28 ... Exhaust slit 30 ... Control device 31 ... Resonance capacitor 32 ... Resonance circuit 33 ... Commercial power supply 34 ... Rectifier circuit 35A ... Switching element 35B ... Switching element 36 ... Inverter circuit 37A, 37B ... Drive circuit 38 ... Control unit 39 ... Temperature Detection circuit 40 ... Current detection circuit 41 ... Voltage detection circuit 42 ... A / D conversion circuit 43 ... CPU
44 ... ROM
45 ... RAM

Claims (5)

A switching element is provided to control energization to the excitation coil arranged under the top plate of the electromagnetic cooker body, and the drive circuit for driving the switching element and the excitation signal supplied to the excitation coil are supplied to the excitation coil A control unit that controls the high-frequency power to be close to the target power value, and a type determination unit that determines the type of the cooking container (or pan) placed on the top plate, and matches the determined type In an electromagnetic cooker configured to maintain the oil in the cooking container (or pan) at a predetermined heat-retaining temperature under control,
A temperature determining means for determining whether or not the cooking container (or pan) is heated to a temperature equal to or higher than a predetermined temperature or exceeding a predetermined temperature;
When it is determined by the temperature determination means that it is not in a heated state, the determination is executed while the energization of the exciting coil is in a high power state, and when the temperature determination means determines that it is in a heated state, the cooking container The electromagnetic cooker according to claim 1, wherein the determination is performed in a state where the energization of the exciting coil is in a low power state so as to suppress ignition of oil in the (or pan).   2. The electromagnetic cooker according to claim 1, wherein the temperature determination unit is configured to detect the temperature of the cooking container (or pan) by a temperature detection sensor disposed in a central portion of the excitation coil. .   The said kind determination means determines the material of the said cooking container (or pan) by the difference in the drive frequency of the said control signal when heating the said cooking container (or pan) with a fixed input. Or the electromagnetic cooker of 2.   The type determining means determines that the control signal drive frequency is equal to or higher than a predetermined upper limit value or exceeds a predetermined upper limit value, and is determined as a cooking container of the first type of material, and is equal to or lower than a predetermined lower limit value or a predetermined lower limit value. If it is less than, it is determined that the cooking container is made of the second type of material, and if it is within the range between the upper limit value and the lower limit value, there is provided a material judging means for judging that the cooking container is made of the third type of material. The electromagnetic cooker according to claim 1 or 2.   The type determination means includes a first determination means for determining the material of the cooking container (or pan) depending on whether the driving frequency of the control signal is higher or lower than a predetermined upper limit value, and a predetermined lower limit value. The electromagnetic cooking of Claim 1 or 2 provided with the material determination means provided with the 2nd determination means which determines the material of the said cooking container (or pan) with respect to high or low with respect to it. vessel.

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