JP2874353B2 - Electric cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating cooker in which a temperature sensor is provided below a heat-resistant plate to accurately detect a change in oil temperature in a cooking vessel on the heat-resistant plate and to control the oil temperature.

[0002]

2. Description of the Prior Art As shown in FIGS. 6 and 7, a conventional electric cooker of this type has an appliance body 1 having an open upper portion and a heat-resistant glass as a heat-resistant plate provided at the opening of the appliance body 1. 2, a heater unit 3 housed in the appliance main body 1 and provided between the heat-resistant glass 2 and a heater positioned inside the heater unit 3 so that radiation from the heater does not directly hit the temperature sensor 5. A temperature sensor 5 that is covered with a heat insulating material tube 4 as a heat radiation suppressor made of an inorganic fiber foam or the like and is in contact with the back surface of the heat resistant glass 2. 2, a temperature detector 6 for detecting the temperature of the heater unit 2, an on-off temperature setting unit 7 for setting an on-off temperature for supplying and stopping power to the heater unit 3, and an on-off temperature setting unit 7.
And a control circuit 9 having a power control unit 8 for controlling the power to the heater unit 3 from the set temperature of the heater unit 3 and the temperature detected by the temperature detection unit 6. When the operation is performed with the cooking vessel 10 placed on the glass 2, the temperature detection unit 6 detects the temperature of the cooking vessel 10 via the heat-resistant glass 2 by the temperature sensor 5,
The temperature of tempura oil etc. was detected. The power control unit 8 controls the power to the heater unit 3 based on the temperature set by the temperature setting unit 7 and the temperature detected by the temperature detection unit 6 to adjust the temperature.

[0003]

However, in the above-mentioned structure, in the case of tempura cooking, the heating unit 3 is supplied to the heater unit 3 in spite of the fact that the heat load is different depending on the kind of the material to be cooked and the amount of the material to be put into the oil. And the on-off temperature set by the on-off temperature setting section remained constant. Therefore, if the heat load is small,
There is a problem that the control temperature of the oil by turning off is higher than when the heat load is large, and deviates from the set temperature.
For example, in FIG. 8, when the cooking temperature is set to 200 ° C. and 200 g of potato is poured into 1100 g of oil at time Z, when the detection temperature 11 of the temperature sensor 5 falls to the ON set temperature, the heater 3 is re-energized. When the temperature starts to rise, on-off is repeated thereafter.
No. 2 shows a similar tendency and is equilibrated at about 200 ° C. On the other hand, under the same conditions, when the heat load was 50 g and the heat load was reduced to 1/4, similarly, when the heat load was applied at time Z, the oil temperature 12 was equilibrated at about 225 ° C.
5 ° C temperature is high. This is because the oil temperature rises excessively because the heater power value and the OFF temperature are the same even though the heat load is reduced. As described above, there is a problem that oil temperature fluctuations increase depending on the magnitude of the heat load, and cooking cannot be performed at an optimum cooking temperature, so that it is difficult to produce delicious tempura.

The present invention relates to a method in which a temperature sensor detects the temperature of the back surface of a top glass. When the heat load is small due to the type of the material to be cooked in the tempura and the amount to be put into the oil, the oil is turned on and off. An object of the present invention is to solve the problem that the control temperature rises as compared with the case where the heat load is large and deviates from the optimal cooking set temperature, so that delicious tempura cannot be obtained.

[0005]

In order to achieve the above object, the present invention provides an electric power value to a heater unit and an on-off temperature based on a falling value of a temperature detected from a temperature detector after a set-off temperature is reached. Fuzzy control rule storage unit that stores the control level change value of the fuzzy control rule as a fuzzy control rule, performs fuzzy inference processing by referring to the fuzzy control rule of the fuzzy control rule storage unit based on the detected temperature, and performs the power value to the heater unit and the power ON. -A control circuit having a fuzzy control inference unit for determining a control level change value of the off-temperature is provided.

[0006]

According to the present invention, the above-described structure has the following effects. That is, the temperature detecting unit detects the temperature of the cooking vessel, that is, the temperature of the tempura oil or the like, via the heat resistant glass by the temperature sensor. Since the fuzzy control rule storage unit stores the power value to the heater unit and the control level change value of the on-off temperature as a fuzzy control rule, the fuzzy control inference unit stores the fuzzy control rule based on the detected temperature. The fuzzy inference processing is performed with reference to the fuzzy control rule of (1), and the power value to the heater unit and the control level change value of the on-off temperature are determined.

[0007] Therefore, the heat load varies depending on the type of ingredients and the amount of oil to be charged in tempura cooking, but when the heat load is small, the heater power after the charging is reduced, and the on-off set temperature is further reduced. Can also be changed to a lower temperature than the initial setting. Therefore, the control temperature of the oil can maintain the optimal cooking set temperature regardless of the heat load.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1 and FIG. 2, reference numeral 13 denotes a fuzzy control rule storage unit, and the temperature detection unit 6 after reaching the set off temperature.
The power value to the heater unit 3 and the control level change value of the on-off temperature are stored as a fuzzy control rule based on the fall value of the detected temperature from. An example of a fuzzy control rule is shown.

(1) If the degree of if temperature drop (L) is small, then the heater power is reduced.

(2) If the degree of if temperature drop (L) is medium, then the heater power is increased. (3) If the degree of if temperature drop (L) is large, then the heater power is increased.

(4) If the degree of if temperature drop (L) is small, the then control level is lowered. (5) If the degree of if temperature drop (L) is medium, the then control level is set to medium.

(6) If the degree of if temperature drop (L) is large, the then control level is increased. As described above, the fuzzy control rules are stored in the if-then- format.

Here, the control variable "small" is defined by the membership function shown in FIG. A fuzzy control inference unit 14 performs a fuzzy inference process by referring to the fuzzy control rules in the fuzzy control storage unit 13 based on the temperature detected by the temperature detection unit 6 and performs a fuzzy inference process.
And the on-off temperature. 9A is a control circuit.

The operation of this embodiment will be described below. The temperature detector 6 detects the temperature of the cooking vessel 10 via the heat-resistant glass 2 by the temperature sensor 5, that is, the temperature of the tempura oil or the like. While the temperature is lower than the OFF temperature set by the ON-OFF temperature setting unit 7, the power control unit 8 supplies power to the heater unit 3 and heats the heater unit 3 to increase the oil temperature. Then, when the temperature detected by the temperature detection unit 6 reaches the off-temperature set by the on-off temperature setting unit 7, the power control unit 8 stops power to the heater unit 3. On the other hand, the fuzzy control inference unit 14 determines the temperature difference L between the detected temperatures T1 and T2 from the detected temperature T1 after a certain set time Z1 and the detected temperature T2 after a certain set time Z2 at the same time when the OFF temperature is reached.
The fuzzy inference process is performed with reference to the fuzzy control rules of the fuzzy control rule storage unit 13 based on the calculated values to determine the power value to the heater unit 3 and the control level change value of the on-off temperature. In FIG. 4, the region A is at the time of heating rise, the on-off temperature is “set value”, and the heater power is also rated 1900 w. The area B is a case where the temperature difference L is converted into a degree of temperature drop and becomes “4”. According to the membership function of FIG. 3A, “large degree” is 0, “medium degree” is 0.5 “small”. Is 0.5. Thus, the degree of power to the heater unit in FIG. 3B is determined from the inference rules. In this case, the "large degree" is 0.5 and the "small degree" is 0.5, and 1440w is determined from the center of gravity. Next, from FIG.
The degree of the control level change value of the off-temperature is obtained. In this case, the "high degree" is 0, the "medium degree" is 0.5, and the "low degree" is 0.5. "-2.25" is obtained from the center of gravity.
Next, the case of actually cooking tempura will be described with reference to FIG. When the load is large, for example, the cooking temperature is set to 200 ° C., and 1100 g of oil and 20 potatoes are used.
If 0 g is supplied at the time Z after reaching the set off temperature, the detected temperature T1 when the certain set time Z1 is 10 seconds is 2
The detection temperature T2 was 235 ° C. when a certain set time Z2 was set to 40 seconds. Detection temperature T1 and T2
Was 15 ° C. The fuzzy control inference unit 14 converts this L = 27 ° C. into the detected temperature drop degree “6”, then refers to the fuzzy control rules in the fuzzy control rule storage unit 13 and as described above, calculates the heater unit from the membership function of FIG. Power value to 3 is "strong" (1900w), on-
The control level change value of the OFF temperature is “0 level” (no change). In this case, the detected temperature 1 of the temperature sensor 5
When the temperature drops to the set ON temperature, the heater 3 is re-energized, and when the temperature starts to rise, the heater is repeatedly turned on and off thereafter. However, the oil temperature 12 also shows the same tendency, and the oil temperature 12 equilibrates at about 205 ° C. I have. When the load is small, for example, 1100
In the case where the heat load is reduced to 1/4 with 50 g of potatoes in the oil of g, if the set temperature is reached at the same time after reaching the set off temperature, the detection temperature T when a certain set time Z1 is set to 10 seconds is obtained.
1 was 250 ° C., and the detection temperature T2 was 240 ° C. when a certain set time Z2 was set to 40 seconds. Detection temperature T1
The difference L between T2 and T2 is 10 ° C. Fuzzy control inference unit 1
4 indicates that the temperature difference L = 10 ° C. is detected and the temperature drop degree is “1”.
After the conversion, the power value to the heater unit 3 from the membership function of FIG. 3 to the heater unit 3 is “weak” (1380) with reference to the fuzzy control rule in the fuzzy control rule storage unit 13 as described above.
w), the change value of the on-off temperature is lowered by "-3 level". The oil temperature 12 in this case is equilibrated at about 212 ° C., and has not changed much compared to the case of 200 g. Therefore, even when the load is small, a delicious tempura is produced without increasing the control temperature as compared with the case where the load is large.

[0016]

As described above, according to the present invention, the fuzzy control rule storage unit stores the power value to the heater unit and the control level change value of the on-off temperature as a fuzzy control rule based on the temperature detected by the temperature detecting unit. The fuzzy inference process is performed by referring to the fuzzy control rule in the fuzzy control rule storage unit based on the detected temperature, and the power value to the heater unit and the ON-
By providing a control circuit having a fuzzy control inference unit for determining the control level change value of the off-temperature, the fuzzy control inference unit refers to the fuzzy control rule in the fuzzy control rule storage unit based on the detected temperature to perform fuzzy inference processing. In order to determine the power value to the heater unit and the control level change value of the on-off temperature, the heat load changes depending on the type of ingredients, the amount of oil to be charged in the tempura cooking, etc. The heater power is reduced and the on-off temperature is also reduced, so that the oil control temperature does not change as compared with the case where the heat load is large, and the problem that the cooking temperature deviates from the optimal cooking set temperature as in the past is solved. You can cook delicious tempura.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view of an electric heating cooker according to one embodiment of the present invention.

FIG. 2 is a block diagram of a control circuit of the electric heating cooker according to one embodiment of the present invention.

FIG. 3A is a diagram illustrating a membership function indicating a degree of a detected temperature of the electric heating cooker according to one embodiment of the present invention. B a membership function indicating heater power of the electric heating cooker according to one embodiment of the present invention. Explanatory diagram C Explanatory diagram of the membership function representing the amount of change in the control level of the electric heating cooker according to one embodiment of the present invention.

FIG. 4 is a conceptual diagram of temperature characteristics and fuzzy control rules applied by an electric heating cooker according to one embodiment of the present invention.

FIG. 5 is a temperature characteristic diagram at the time of actual cooking by the electric heating cooker according to one embodiment of the present invention.

FIG. 6 is a partial cross-sectional perspective view of a conventional electric heating cooker.

FIG. 7 is a block diagram of a control circuit of a conventional electric heating cooker.

FIG. 8 is a temperature characteristic diagram during actual cooking by a conventional electric heating cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument main body 2 Heat-resistant plate 3 Heater unit 4 Heat radiation suppressor 5 Temperature sensor 6 Temperature detection unit 7 On-off temperature setting unit 8 Power control unit 9A Control circuit 13 Fuzzy control rule storage unit 14 Fuzzy control inference unit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Teruhiko Hiraishi 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-59-231326 (JP, A) JP-A-61- 186728 (JP, A) JP-A-2-259335 (JP, A) JP-A-61-86607 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24C 7/04 301 H05B 3/00 330

Claims (2)

(57) [Claims] 1. A heat-resistant plate on which a cooking vessel is mounted on an upper portion, an appliance body for installing the heat-resistant plate in an upper opening, and a heat-resistant plate housed in the appliance body and provided between the heat-resistant plate. A heater unit, a temperature sensor whose detection unit is in contact with a lower portion of the heat-resistant plate, and a control circuit, and the control circuit detects a temperature of the heat-resistant plate with the temperature sensor, An on-off temperature setting unit for setting an on-off temperature for supplying and stopping power to the heater unit, and when the set-off temperature is reached, a detected temperature after a set time Z1 starting from the set time is set to T1. Further, a detected temperature after a certain set time Z2 is T2, a difference between the detected temperatures T1 and T2 is L, and a value of L supplied to the heater unit and a control level change value of the on-off temperature are determined by the value of L. And A fuzzy control rule storage unit for storing as a fuzzy control rule, performing fuzzy inference processing by referring to a fuzzy control rule in the fuzzy control rule storage unit based on a difference L between the detected temperatures T1 and T2 and supplying the fuzzy control rule to the heater unit A fuzzy control inference unit that determines a power value and a control level change value of an on-off temperature, and supplies power to a heater unit in response to a supply power value from the fuzzy control inference unit and a control level change value of an on-off temperature. An electric heating cooker comprising a power control unit for controlling. 2. A heat radiation plate, wherein the heat-resistant plate is made of heat-resistant glass and covers the periphery of a temperature sensor in which a detecting portion is in contact with a lower surface of the heat-resistant glass to prevent the temperature sensor from being directly exposed to radiation from a heater. The electric heating cooker according to claim 1, wherein the electric heating cooker is configured to have a suppressor.