JP2003007444A - Electromagnetic cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect boiling of water inside of a cooking container when the cooking container put on a cooking container receiver is heated in an electromagnetic cooker. SOLUTION: A temperature detecting element 5 is arranged on the upper face of the cooking container receiver 2, and based on this detected temperature, a gradient calculation means 13 detects a temperature change in starting heating as the first gradient and detects the temperature change at the prescribed temperature in the intermediate time of the heating as the second gradient. A tightly contacted state of the bottom face form of the cooking container 1 with the cooking container receiver is judged by the first gradient, and the gradient to become the standard of detecting the boiling is estimated by a fuzzy inference based on the first gradient and the second gradient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic cooker capable of automatically detecting boiling of cooked food.

[0002]

2. Description of the Related Art The structure of a conventional electromagnetic cooker with an automatic boiling detection function will be described with reference to FIG. Reference numeral 101 denotes a cooking container placed on a cooking container receiver 102 made of a ceramic plate, which is induction-heated by a high-frequency magnetic field generated by an induction heating coil 103 provided under the cooking container receiver 102. 104 is an induction heating coil 103
Coil current control means for supplying a high frequency current to the high frequency inverter circuit 104a and the high frequency inverter output control circuit 104b. Reference numeral 105 denotes a temperature sensor attached to the lower surface of the cooking container receiver 102, which indirectly detects the temperature of the cooking container 101 by detecting the temperature of the cooking container receiver 102. The output of the temperature detecting element 105 is an automatic boiling detecting means 106 for automatically detecting the start of boiling.
Have been transmitted to. Further, 107 is a start input means composed of a switch for the user to instruct the start of operation, and this signal is similarly transmitted to the automatic boiling detection means 106. The first inclination detecting means 108 constituting the automatic boiling detecting means 106 receives the output of the temperature detecting element 105, and
As shown in (1), the slope of the average temperature rise from the first predetermined temperature T1 to the second predetermined temperature T2 is detected. In other words, the time required to pass these two temperatures is measured to detect the average temperature rise slope. The tilt calculating means 109 calculates 1/3 of the tilt detected by the first tilt detecting means 108. This 1/3 is an empirically determined value. The second inclination detecting means 110 receives the detected temperature signal of the temperature detecting element 105 and detects the differential value, that is, the inclination, at any time. The boiling determination means 111 which is the output of the automatic boiling detection means 106 is the second inclination detection means 11
By comparing the output of 0 and the output of the inclination calculating means 109, when the output of the second inclination detecting means 110 becomes smaller than the output of the inclination calculating means 109, the food in the cooking container 101 boils. To judge. That is, the output of the coil current control means 104 is stopped at this point, and the supply of the high frequency current to the induction heating coil 103 is stopped.

[0003]

The above-described conventional electromagnetic cooker has a problem that the setting of the boiling detection timing is not very accurate. That is, the inclination of the temperature rise detected by the first inclination detection means becomes unstable because the shape of the cooking container 101, especially the shape of the bottom surface, may not be in close contact with the cooking container receiver 102. There is. For this reason, the boiling detection timing may be earlier or later.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an electromagnetic cooker capable of detecting boiling with high accuracy.

[0005]

[Means for Solving the Problems] A first means of the present invention for achieving the above object is to provide a cooking container receiver for receiving a cooking container, and induction heating for generating a high frequency magnetic field arranged on the lower surface of the cooking container receiver. A coil, a temperature detecting element arranged on the upper surface of the cooking container receiver for detecting the temperature so that the cooking container receiver is substantially flat, and an inclination serving as a reference for boiling detection by receiving the output of the temperature detecting device. An inclination calculating means for calculating, a third inclination detecting means for receiving the output of the temperature detecting element to detect the inclination of the detected temperature at any time, and an output of the inclination calculating means and an output of the third inclination detecting means are compared. And a boiling determination means for changing the heating amount of the heating coil when determining the boiling start time, the gradient calculation means, the temperature change at the start of heating is the first gradient, at a predetermined temperature during heating intermediate. Change in temperature Detected as the second inclination, and determine the contact state between the bottom shape of the cooking container and the cooking container receiver by the first inclination, and the boiling detection reference from the first inclination and the second inclination. This is an electromagnetic cooker that calculates the inclination.

According to a second aspect of the present invention, in addition to the above-mentioned first means, the inclination calculating means determines a gradient which is a reference for boiling detection by fuzzy inference based on the first inclination and the second inclination. It is an inferred electromagnetic cooker.

The third means of the present invention is, in addition to the first or second means, an electromagnetic means provided with a delay means for determining the delay time based on the first inclination and delaying the judgment of the boiling judgment means. It is a cooking device.

The fourth means of the present invention is, in addition to the above-mentioned third means, the delay means is an electromagnetic cooker for inferring a delay time for boiling judgment from the first slope and the second slope by fuzzy inference. To do.

[0009]

The first means of the present invention devises the installation of the temperature detecting element and sets the boiling detection reference based on the two detection values of the first inclination and the second inclination. , Which functions as an electromagnetic cooker capable of highly accurate boiling detection.

In the second means of the present invention, the inclination calculating means receives the first and second inclination information and fuzzyly infers the optimum boiling detection reference, so that more accurate boiling detection is possible. It functions as an electromagnetic cooker.

In the third means of the present invention, the delay means acts so as to delay the boiling judgment by determining the delay time based on the first inclination, and it is possible to detect boiling with higher accuracy. It realizes a simple electromagnetic cooker.

Further, in the fourth means of the present invention, the delay means infers the optimum boiling detection criterion by the gradient fuzzy inference, further infers the optimum delay time by the delay time fuzzy inference, and is optimum for the boiling judgment. Since it acts to have a delay, more accurate boiling detection is realized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first reference example according to the present invention will be described below with reference to FIGS. In the figure, reference numeral 1 denotes a cooking container such as a pot, the bottom surface of which is in close contact with the cooking container receiver 2. The cooking container receiver 2 is made of a ceramic plate or the like, and an induction heating coil 3 for generating a high frequency magnetic field is provided on the lower surface of the cooking container receiver 2. This induction heating coil 3
The high frequency current supplied to the induction heating coil 3 is connected to the high frequency current output part of the high frequency inverter circuit 4a.
And a high-frequency inverter output control circuit 4 for controlling the oscillation of the high-frequency inverter circuit 4a and controlling the high-frequency output current.
The coil current control means 4 composed of b. The coil current control means 4 includes a knob for adjusting the output of the induction heating coil 3. Reference numeral 5 denotes a temperature detecting element attached to the central portion of the lower surface of the cooking container receiver 2 for detecting the temperature. Reference numeral 6 denotes a start input means for the user to instruct the start of heating, which is composed of a switch. The user sets cooking ingredients in the cooking container 1 and operates the start input means 6. 7
Is an automatic boiling detection means which is the essence of the present embodiment, and when it receives a cooking start signal from the start input means 6, sends a heating start signal to the coil current control means 4. Automatic boiling detection means 7
Is the first tilt detecting means 11 and the second tilt detecting means 12
The inclination calculating means 13, the third inclination detecting means 14, and the boiling determining means 15 are included.

The first inclination detecting means 11 receives the temperature information detected by the temperature detecting element 5 and detects the inclination of the temperature rise for a preset time dt1 from the heating start time t1. . Further, the second inclination calculating means 12
Similarly, the temperature information from the temperature detecting element 5 is received, and the slope of the temperature increase from the preset temperature T1 to the temperature T2 having a predetermined temperature difference dT from T1 is detected. . The T1 is the first tilt detecting means 1
1 is set at the timing when the tilt detection is completed. The outputs of the first tilt detecting means 11 and the second tilt detecting means 12 are sent to the tilt calculating means 13.

The inclination calculating means 13 determines a reference inclination based on the two pieces of inclination information.
The third inclination detecting means 14 receives the temperature detected by the temperature detecting element 5 similarly to the first and second inclination detecting means 11 and 12, and the second inclination detecting means 12 detects the second inclination. After that, the slope of the temperature rise is detected at any time. That is, the differential value of the temperature detected by the temperature detecting element 5 with respect to time is detected.

The boiling determining means 15 compares the output of the inclination calculating means 13 with the output of the third inclination detecting means 14,
When the output of the third inclination detecting means becomes smaller, it is determined as the boiling timing of the cooked food. At this boiling timing, the boiling determination means 15 drives the high frequency inverter output control circuit 4b constituting the coil current control means 4 to change the output to a preset output.

The operation of this reference example will be described below. The cooking container 1 used in this embodiment is a dedicated container that comes into close contact with the cooking container receiver 2. That is, most of the high-frequency magnetic field generated by the induction heating coil 3 is effectively used for induction heating of the cooking container 1. Therefore, the temperature detection element 5 can detect an accurate and highly accurate temperature.

The operation of the automatic boiling detection means 7 will be described below with reference to FIG. It is assumed that the user finishes preparations for cooking and operates the start input means 6 at time t1. This signal is transmitted to the automatic boiling detection means 7. Automatic boiling detection means 7
When it receives this signal, it first resets itself to a mode in which boiling is not detected. At the same time, the coil current control means 4 is driven with the heating output set to the maximum. In this way, a high-frequency current is supplied to the induction heating coil 3, and the cooking container 1 starts to increase in temperature from time t1. This temperature is detected by the temperature detecting element 5, and the first, second and third inclination detecting means 11, 12, 14 start operating.

The first inclination detecting means 11 detects the inclination of temperature rise between time t1 and time t2 having a predetermined time difference from time t1. That is, the first inclination is detected. The second inclination detecting means 12 receives the temperature information from the temperature detecting element 5 and preset temperatures T1 to T1.
From the temperature rise to the temperature T2 having the predetermined temperature difference dT, the slope of the temperature rise and the second slope are detected. Although the slope of the temperature rise until the cooked product reaches boiling varies depending on the amount and type of the cooked product as described in the conventional example, the inventors of the present invention have conducted experiments and found that the cooking container 1 is a dedicated one. Then, it has been found that the slope of this temperature rise has a correlation with the first slope and the second slope. From the first and second slopes, the slope calculating means 13 calculates and determines the slope when the food is boiling, in other words, the slope K1 that serves as a reference for temperature control, according to the following equation. It is a thing.

K1 = (second slope) / (C1 × (first slope) + C2) (where C1 and C2 are preset constants) After the temperature control reference K is determined in this way, The third inclination detecting means 14 receives the output of the temperature detecting element 5 and detects the third inclination at any time. The information indicating the third inclination is transmitted to the boiling determination means 15 together with the temperature control reference K1 and is used to determine whether or not the boiling state is reached. That is, the boiling determination means 15 determines that the cooking product has reached the boiling state at the timing when the information indicating the third inclination has a value smaller than the temperature control reference K1 and moves to a state having a smaller value. Is what you are doing.

When the boiling state is determined, the boiling determining means 13 acts to reduce the setting of the heating output of the coil current control means 4 to a preset value.
Further, it is more preferable to notify that the boiling state has been reached at this time by using an appropriate means.

As described above, according to the present embodiment, the boiling state can be detected accurately and automatically, so that the user can do another work with peace of mind.

Next, a second reference example according to the present invention will be described with reference to FIG. The same parts as those in the above embodiment are designated by the same reference numerals, and the following description will be omitted. Reference numeral 21 is an automatic boiling detection means, which has a fuzzy inference means 22. The fuzzy inference means 22 includes the following elements. Reference numeral 23 is a first inclination membership storage means for storing a membership function for inferring the degree of the first inclination shown in FIG. Reference numeral 24 is a first inclination adaptability calculating means for inferring the first inclination degree based on the output of the first inclination detecting means 11.

Reference numeral 25 is a second slope membership storage means for storing a membership function for inferring the degree of the second slope shown in FIG. 4 (b). Reference numeral 26 is a second inclination adaptability calculating means for inferring the second inclination degree based on the output of the second inclination detecting means 12. The outputs of the first slope adaptability calculating means 24 and the second slope adaptability calculating means 25 are sent to the output adaptability calculating means 28 for calculating the slope which is the boiling control reference. The output fitness calculation means 28
This information is once sent to the output membership function storage means 27, and the optimum output value for inferring the optimum output from the membership function shown in FIG. 4C is determined. Upon receipt of this information, the output adaptability calculating means 28 finally determines the inclination which is the boiling control reference, and transmits this signal to the boiling determining means 15. The functions of the third inclination detecting means 14 and the boiling determining means 15 are the same as those in the above embodiment.

The operation of this reference example will be described below. When the user operates the start input means 6 to start cooking, a high-frequency magnetic field is generated from the induction heating coil 3 to start heating the cooking container 1. The temperature of the cooking container 1 is detected by the temperature detecting element 5 provided in the cooking container receiver 2. The temperature information of the temperature detecting element 5 is sent to the first inclination detecting means 11 and then to the second inclination detecting means 12, and the fuzzy inference means 22 starts fuzzy inference. That is,
The first inclination adaptability calculating means 24, which has received the information on the temperature change at the initial stage of heating from the first inclination detecting means 11, sends this information to the first inclination membership function storing means 23,
The first slope in the initial heating is calculated and determined.

Further, the second inclination adaptability calculating means 26 which has received the information of the temperature change at the intermediate temperature from the second inclination detecting means 12 similarly sends this information to the second inclination membership function storing means 25. Then, the second slope at the intermediate temperature is calculated and determined. That is, the first inclination membership function storage means 23 evaluates the inclination degree of the temperature rise at the initial heating stage based on the fitness estimation rule shown in FIG. In other words, it is inferred to which stage the current temperature rise gradient is matched when it is divided into five stages from steep to gentle.

Upon receipt of this information from the first inclination detecting means 24, the first inclination adaptability calculating means 24 determines the first inclination and transmits this information to the output adaptability calculating means 28.
Similarly, the second slope adaptability calculating means 26 stores the second slope at the intermediate temperature and the second slope membership function storing means 25.
Is determined from the evaluation value evaluated based on FIG. 4 (b),
It is transmitted to the output adaptability calculating means 28. Upon receiving this information, the output adaptability calculating means 28 temporarily stores this information in FIG.
It is sent to the output membership function storage means 27 having the inference rule shown in FIG. Output membership function storage means 27
Calculates the optimum output value for estimating the gradient that serves as the boiling control reference from the degree of the first gradient and the degree of the second gradient.

Upon receipt of this information, the output adaptability calculating means 28 finally determines the inclination which serves as the boiling control reference, and transmits this signal to the boiling determining means 15. In the boiling determination means 15, the third inclination detection means 14 is the temperature detection element 5
The inclination of the temperature change which is detected at any time by receiving the output of the above and the boiling control reference are compared, and the third inclination detecting means 14
The time when the detection value of is smaller than the boiling control reference is determined as the boiling state. That is, the coil current control means 4 operates so as to be changed to a preset output and operated. Further, as in the above embodiment, it is more preferable to notify the user of the arrival of the boiling state by using an appropriate notification means.

As described above, according to this reference example, since the optimum inference output by fuzzy inference is used, it is possible to realize an electromagnetic cooker capable of detecting boiling with higher accuracy.

Next, the first embodiment of the present invention will be described with reference to FIG.
It will be described based on. The same parts as those in the above embodiment are designated by the same reference numerals, and the following description will be omitted. Reference numeral 31 is a temperature detecting element mounted so as to be embedded in the central portion of the upper surface of the cooking container receiver 2, and the contact surface between the cooking container receiver 2 and the cooking container 1 is flat. Reference numeral 32 denotes an automatic boiling detection means, which has an inclination calculation means 33 for calculating an inclination serving as a reference for temperature control from outputs of the first inclination detection means 11 and the second inclination detection means 12.

The operation of this embodiment will be described below. In this embodiment, the temperature detecting element 31 is provided so as to detect the temperature of the central portion of the cooking container 1 on the upper surface of the cooking container receiver 2. The contact surface of the surface of the cooking container receiver 2 with the cooking container 1 is flat and uniform. Therefore, the temperature detection accuracy of the temperature detection element 31 is much higher than that of the structure of each of the embodiments. Therefore, the correlation between the slope of the temperature rise until the food reaches boiling and the first slope and the second slope is higher.

In the present embodiment, the inclination calculating means 33 has the first inclination detected by the first inclination detecting means 11 at the start of heating and the second inclination in the middle detected by the second inclination detecting means 12. The gradient K2, which is the reference for the temperature control, is calculated and determined by using the following equation.

K2 = (second slope) / (C3 × (first slope) + C4) (where C3 and C4 are preset constants) Note that C3 and C4 are K1 of the above embodiment. It can be determined with higher accuracy than the constants C1 and C2 when setting.

The third inclination detecting means 14 receives the temperature information of the temperature detecting element 31 and detects the inclination of the temperature rise at any time, as in the above embodiment. Also, the boiling determination means 15
The inclination value K2 serving as the temperature control reference is compared with the detection value of the third inclination detecting means 14, and the third inclination detecting means 14 is compared.
The boiling point is determined when the gradient detected by is smaller than the gradient value K3 serving as the temperature control reference. That is, at this time, the coil current control means 4 is operated so as to be changed to a preset output and operated. Further, as in the above embodiment, it is more preferable to notify the user of the arrival of the boiling state by using an appropriate notification means.

As described above, according to this embodiment, the boiling state can be detected more accurately by devising the attachment of the temperature detecting element 31.

Next, the second embodiment of the present invention will be described with reference to FIG.
It will be described based on. The same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and the following description will be omitted. Reference numeral 41 denotes an automatic boiling detection means, which has a delay means 42 for delaying the boiling judgment made by the boiling judgment means on the basis of the output value of the first inclination detection means 11. That is, the delay means 42 delays the boiling determination by the boiling determination means 15 when the inclination detected by the first inclination detection means 11 is smaller than a predetermined value.

The operation of this embodiment will be described below. When the cooking container 1 is placed on the cooking container receiver 2, if a foreign substance such as dust adheres to the bottom back surface of the cooking container 1 or is set in an inclined state, the temperature detecting element 31 will cook. It no longer adheres to the container 1. In such a case, the temperature detection of the temperature detection element 31 is delayed with respect to the temperature rise of the food. In other words, the time at which the start of boiling is detected is also delayed in time. Therefore, in this embodiment, the inclination calculating means 33 determines the inclination K3 which is the temperature control reference shown by the following equation, based on the outputs of the first inclination detecting means 11 and the second inclination detecting means 12.

K3 = ((second slope) / (C5 × (first slope) + C6)) * a C5 · C6: preset constant a: preset constant larger than 1, that is, in this embodiment The temperature control reference slope K3 is set large, in other words, boiling detection is performed at an early stage. In this state, the boiling determination means 15 outputs the output of the third inclination detection means 14 and the K
The arrival at the boiling state is detected by comparing with No. 3. The output of the boiling determination means is the delay means 42.
Is sent to the coil current control means 4 via. At this time, when the delaying means 42 recognizes that the output of the first inclination detecting means 11 is smaller than usual, that is, it is in the state of the mounting abnormality described above, the output of the boiling determining means is directly used for the coil current control means. 4 to reduce the output of the coil current control means 4 to a predetermined value.

When the delay means 42 recognizes that the output of the first inclination detecting means 11 is normal, the output of the boiling determining means is delayed by a predetermined time and transmitted to the coil current controlling means 4. The output of the coil current control means 4 is reduced to a predetermined value. That is, the delay means 42 acts so as to delay the regular boiling determination timing by a predetermined time when the placement is abnormal.

As described above, according to this embodiment, by providing the delay means 42, it is possible to provide an electromagnetic cooker capable of coping with variations in setting of cooking containers.

Next, a third embodiment of the present invention will be described with reference to FIG. Reference numeral 51 is an automatic boiling detection means, which has a fuzzy inference means 52. The fuzzy inference means 52 includes the following elements. Reference numeral 53 is a first slope membership function storage means for storing a membership function for inferring the degree of the first slope shown in FIG. Reference numeral 54 is a first inclination adaptability calculating means for inferring the first inclination degree based on the output of the first inclination membership function storage means 53. Reference numeral 55 is a second slope membership function storage means for storing a membership function for inferring the degree of the second slope shown in FIG. 8B. Reference numeral 56 is a second slope adaptability calculating means for inferring the second slope degree based on the output of the second slope membership function storage means 55.

The outputs of the first slope adaptability calculating means 54 and the second slope adaptability calculating means 56 are sent to the output adaptability calculating means 58 for calculating the slope as the boiling control reference. The output fitness calculating means 58 once sends this information to the output membership function storing means 57, and determines the optimum output value for inferring the optimum output from the membership function shown in FIG. 8C. . Upon receipt of this information, the output adaptability calculating means 58 finally determines the inclination which serves as the boiling control reference, and transmits this signal to the boiling determining means 15.

The operation of this embodiment will be described below. When the user operates the start input means 6 to start cooking, a high-frequency magnetic field is generated from the induction heating coil 3 to start heating the cooking container 1. This temperature is accurately detected by the temperature detecting element 5, sent to the first inclination detecting means 11 and then to the second inclination detecting means 12, and the fuzzy inference means 5 is sent.
2 starts fuzzy reasoning. That is, the first inclination adaptability calculating means 54, which has received the information on the temperature change at the initial stage of heating from the first inclination detecting means 11, sends this information to the first inclination membership function storage means 53 to perform heating. The first inclination in the initial stage is calculated and determined.

Further, the second inclination adaptability calculating means 56 which has received the information of the temperature change at the intermediate temperature from the second inclination detecting means 12 similarly sends this information to the second inclination membership function storing means 55. Then, the second slope at the intermediate temperature is calculated and determined. That is, the first inclination membership function storage means 53 evaluates the inclination degree of the temperature rise at the initial heating stage based on the membership function shown in FIG. The membership function is designed so as to minimize the influence of fluctuations in thermal adhesion between the cooking container 1 and the cooking container receiver 2, in particular. That is, the degree of the initial temperature rise is influenced by the degree of adhesion between the cooking container 1 and the cooking vessel receiver 2, and therefore the estimation rule is such that the degree of this degree of adhesion can be evaluated. The first slope membership storage means 52 uses this rule to infer which stage the current slope of temperature rise corresponds to when it is divided into five stages from steep to gentle. It is a thing.

Upon receipt of this information from the first inclination detecting means 53, the first inclination adaptability calculating means 54 determines the first inclination and transmits this information to the output adaptability calculating means 58.
The second slope adaptability calculating means 56 similarly sets the second slope to the intermediate temperature, and the second slope membership function storing means 55.
Is determined from the evaluation value evaluated based on FIG. 8 (b),
This is transmitted to the output compatibility calculation means 58. The membership function stored in the second membership function storage means 55 is also designed to minimize the influence of the fluctuation of the thermal adhesion between the cooking container 1 and the cooking container receiver 2. There is. That is, the degree of temperature rise at the intermediate time is affected by the degree of adhesion between the cooking container 1 and the cooking container receiver 2,
The estimation rule is such that the degree of adhesion can be evaluated.

The output adaptability calculating means 58 which has received this information
Sends this information to the output membership storage means 57 provided with the inference rules shown in FIG. 8 (c). Figure 8 (c)
The inference rule shown in FIG. 4 can infer the reference value of the inclination for detecting boiling more accurately than that shown in FIG. Output membership storage means 57
Uses this inference rule to calculate the optimum output value for estimating the gradient that serves as the boiling control reference from the degree of the first gradient and the degree of the second gradient. Output fitness calculation means 5
8 receives this information, finally determines the inclination that serves as the boiling control reference, and transmits this signal to the boiling determination means 15.

At this time, in this embodiment, the fuzzy inference means 5 is used.
The inclination which is the boiling control criterion determined by 2 is set on the assumption that the cooking container 1 is placed on the cooking container receiver 2 in an abnormal manner, that is, is set to a slightly large setting. . For this reason, the boiling determination timing determined by the boiling determination means 15 is an appropriate determination timing when dust or the like is attached. That is, the delay means 42
When it is determined that the detection output of the first inclination detecting means 11 is smaller than a predetermined value and dust is attached or there is an abnormal placement, the output of the boiling determining means 15 is sent to the coil current control means 4 as it is and the coil is immediately turned on. The output of the current control means 4 is reduced to a predetermined value. When the normal state is determined, the output of the boiling determination means 15 is delayed by a predetermined time to control the coil current control means 4.

As described above, according to this embodiment, since the fuzzy inference means 52 and the delay means 42 are provided, the optimum inference output can always be obtained and the placement abnormality of the cooking container can be dealt with. .

Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the automatic boiling detection means 5
1 has a fuzzy inference means 62. The fuzzy inference means 62 includes a delay membership function storage means 63 for determining the delay time of the delay means 42 and a delay fitness calculation means 64.
It has and. The delay membership storage unit 63 includes the fitness estimation rule shown in FIG. This adaptability estimation rule is designed so as to reduce the influence of fluctuations in thermal adhesion between the cooking container 1 and the cooking container receiver 2, in particular.

The operation of this embodiment will be described below. From the information of the first inclination detecting means 11, both the calculation of the first inclination adaptability by the first inclination adaptability calculating means 54 and the delay time adaptability by the delay adaptability calculating means 64 can be determined. Therefore, the boiling determination timing of the boiling determination means 15 can be appropriately delayed according to the degree of thermal contact between the cooking container 1 and the cooking container receiver 2.

As described above, according to this embodiment, it is possible to realize an electromagnetic cooker capable of always making accurate and highly accurate boiling determination.

[0052]

The first means of the present invention comprises the third inclination detecting means, the inclination calculating means, and the boiling determining means, and the inclination calculating means measures the temperature change at the start of heating by the first inclination. The temperature change at a predetermined temperature during heating is detected as a second inclination, and the first inclination is used to determine the close contact state between the bottom shape of the cooking container and the cooking container receiver. In order to realize an electromagnetic cooker capable of highly accurate boiling detection, the inclination which serves as a reference for boiling detection is calculated from the inclination and the second inclination. And
By providing the temperature detecting element on the upper surface of the cooking container receiver, it is possible to reduce variations in the detection characteristics of the temperature detecting element and realize an electromagnetic cooker capable of highly accurate boiling detection.

The second means of the present invention comprises a third inclination detecting means, a fuzzy inference means, and a boiling judging means,
The gradient calculating means is configured to infer a gradient as a reference for boiling detection by fuzzy inference based on the first gradient and the second gradient, and the fuzzy inference can be used to determine the optimum reference value for boiling detection. In addition, it is possible to realize an electromagnetic cooker capable of realizing boiling detection with higher accuracy.

The third means of the present invention comprises, in addition to the first and second means, a delay means for determining the delay time based on the first inclination and delaying the judgment of the boiling judgment means. As a result, it is possible to deal with the abnormal state of the cooking container
It is intended to realize an electromagnetic cooker capable of highly accurate boiling detection.

In addition to the fourth means, the fourth means of the present invention is such that the delay means infers the delay time for boiling judgment from the first slope and the second slope by fuzzy inference.
The delay time can be determined with high accuracy, and an electromagnetic cooker capable of detecting boiling with higher accuracy can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of an electromagnetic cooker according to a first reference example.

FIG. 2 is a temperature characteristic diagram showing the same operation.

FIG. 3 is a block diagram of an electromagnetic cooker according to a second reference example.

FIG. 4 is a diagram showing the contents of the fuzzy inference means.

FIG. 5 is a block diagram of an electromagnetic cooker according to the first embodiment of the present invention.

FIG. 6 is a block diagram of an electromagnetic cooker according to a second embodiment of the present invention.

FIG. 7 is a block diagram of an electromagnetic cooker according to a third embodiment of the present invention.

FIG. 8 is a diagram showing the contents of the fuzzy inference means.

FIG. 9 is a block diagram of an electromagnetic cooker according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing a membership function included in the delay membership function storage means.

FIG. 11 is a block diagram of a conventional electromagnetic cooker.

FIG. 12 is a temperature characteristic diagram detected by a temperature detection element of the electromagnetic cooker.

[Explanation of symbols]

1 cooking container 2 cooking container receiver 3 induction heating coil 4 Coil current control means 5 Temperature sensing element 6 Start input means 7, 32, 41 Automatic boiling detection means 11 First tilt detection means 12 Second tilt detecting means 13 Tilt calculation means 14 Third tilt detecting means 15 Boiling determination means 22, 52, 62 Fuzzy inference means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mika Kanou             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Machiko Miyai             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 3K051 AA08 AC07 AC33 AC35 AD04                       AD29 BD04 BD09 BD11 CD03                       CD38

Claims (4)

[Claims] 1. A cooking container receiver for receiving a cooking container, an induction heating coil arranged on a lower surface of the cooking container receiver for generating a high frequency magnetic field, and an cooking coil receiver arranged on an upper surface of the cooking container receiver so that the cooking container receiver is substantially flat. A temperature detecting element configured to detect the temperature, an inclination calculating unit that receives an output of the temperature detecting element and calculates an inclination that serves as a reference for boiling detection, and an output of the temperature detecting element to detect the detected temperature at any time. Boiling determination means for changing the heating amount of the heating coil when the boiling start time is determined by comparing the output of the third inclination detection means with the output of the third inclination detection means for detecting the inclination. And the slope calculating means detects a temperature change at the start of heating as a first slope, detects a temperature change at a predetermined temperature during heating as a second slope, and Bottom of cooking container An electromagnetic cooker that determines a contact state between a surface shape and a cooking vessel receiver and calculates an inclination that serves as a reference for boiling detection from the first inclination and the second inclination. 2. The electromagnetic cooker according to claim 1, wherein the inclination calculating means infers an inclination that serves as a reference for boiling detection by fuzzy inference based on the first inclination and the second inclination. 3. The electromagnetic cooker according to claim 1, further comprising delay means for determining a delay time based on the first inclination and delaying the judgment of the boiling judgment means. 4. The electromagnetic cooker according to claim 4, wherein the delay means infers the delay time for boiling determination from the first slope and the second slope by fuzzy inference.