JPH05290966A - Control device for heating cooker - Google Patents

Abstract

PURPOSE:To prevent cooking oil from firing in abnormally heated state, and maintain the rising performance of oil temperature in the case where a cooking pan having a deflected bottom is used to cook an ingredient. CONSTITUTION:A control circuit 13 is constituted of various electronic circuits such as a judgement means 14 including a microcomputer and a control means 15. Signals from an operation means 16 and a temperature detector 8 are taken into the judgement means 14 for controlling power supply to a heating coil 6. The control circuit 13 has set values comprising the first high control temperature and the second low control temperature, and the set value of the first control temperature is used for normal heating. When the temperature rise of the detector 8 per unit time is equal to or lower than the predetermined value at the start of heating, the set value of the second control temperature is used to control a heating coil 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker control device capable of preventing ignition of cooking oil.

[0002]

2. Description of the Related Art Conventionally, an induction heating cooker has a structure as shown in FIG. The configuration will be described below with reference to the drawings. In the figure, 1 is a plate, 2
Is a frame fixing the plate 1. The main body case 3 is fixed to the frame 2, and has an intake port 4 on the front surface and an exhaust port 5 on the rear surface. The heating coil 6 is fixed to the coil base 7 by spirally winding a plurality of conducting wires. The temperature detector 8 is attached so as to contact the lower surface of the plate 1 from the center of the heating coil 6, and detects the temperature of the cooking pot 9 placed on the upper surface of the plate 1. The control circuit 10 supplies electric power to the heating coil 6. Further, the temperature detector 8 and the control circuit 10 are electrically connected, and the operation of the control circuit 10 is controlled by the temperature of the cooking pot 9. The cooling fan 11 is provided in the vicinity of the intake port 4 and cools heat-generating components in the control circuit 10 and the like.

With the above structure, when cooking oil is put in the cooking pot 9 and tempura is cooked, the user mistakenly cooks the cooking pot 9.
If you continue to heat the cooking oil, the temperature of the cooking oil will rise abnormally, and in the worst case, it will ignite, but in such a case,
The control circuit 10 detects an abnormally high temperature of the temperature detector 8, and when the temperature exceeds a preset control temperature, the current supplied to the heating coil 6 is stopped to prevent the cooking oil from being ignited. To do.

[0004]

However, in the above-mentioned conventional structure, when the cooking pot 9 whose bottom surface 12 is largely warped as shown in FIG. 6 is used, a large air layer is formed between the bottom surface 12 and the plate 1. Since the heat of the cooking pot 9 is less likely to be transferred to the temperature detector 8, the difference between the temperature of the cooking oil in the cooking pot 9 and the temperature of the temperature detector 8 is significantly increased as compared with the flat cooking pot 9. Will be done. Therefore, when the cooking oil is heated in the cooking pot 9 whose bottom surface 12 is largely warped, there is a problem that the cooking oil is ignited before the temperature of the temperature detector 8 reaches the control temperature at which the heating is stopped.

As a method for solving this problem, depending on the magnitude of the temperature rise value of the temperature detector 8 per unit time,
There is a method for determining and controlling whether or not the bottom surface 12 of the cooking pot 9 being heated is warped, but this method has two drawbacks. That is, as shown in FIG. 7, even if the cooking pot 9 is heated with a constant output, the temperature rise curve of the temperature detector 8 changes with time, and the warp state of the bottom surface 12 depends on which time point the inclination is detected. There is a problem in that the temperature rise curve of the temperature detector 8 largely changes not only according to the warped state of the bottom surface 12 but also according to the amount of cooking oil put into the cooking pot 9, so that the warped state of the bottom surface 12 It was difficult to put it into practical use because an accurate judgment could not be made.

The present invention solves the above-mentioned conventional problems. Even when cooking with a cooking pan having a warped bottom, the cooking oil is prevented from being ignited when the cooking oil is abnormally heated, and the cooking oil temperature rises. An object of the present invention is to provide a control device for a heating cooker capable of maintaining performance.

[0007]

In order to achieve the above object, the present invention provides a first solution to a problem that a control circuit has two or more control temperature values having different set temperatures. The higher control temperature value is used during heating, and the lower control temperature value is used when the temperature rise value per unit time of the temperature detector at the start of heating is less than or equal to a preset value. As a second means for solving the problem, another control circuit has two or more heating output values having different set outputs,
The higher heating output value is used during normal heating.If the temperature rise value per unit time of the temperature detector at the start of heating is less than or equal to the preset value, the lower heating output value is used. The heating coil is used to control the heating coil.

[0008]

In the above structure, the operation of the first problem solving means is such that, when the bottom surface of the cooking pot is warped, the temperature rise value per unit time of the temperature detector becomes equal to or less than a preset value, Since the heating output is reduced by controlling the energization based on the control temperature value having a low temperature value, it is possible to prevent the ignition of the cooking oil, and the action of the second problem solving means is that the bottom of the cooking pot is warped. If so, the lower heating power value is used to control the heating coil.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In this embodiment, the same components as those shown in the above-mentioned conventional example are designated by the same reference numerals, and the description thereof will be omitted. The characteristic configuration of the present embodiment is that the control circuit section described in the conventional example is provided with measures against oil ignition.
That is, the control circuit 13 is composed of various electronic circuits such as a judgment means 14 including a microcomputer, a control means 15 and the like, and takes in signals from the operation means 16 and the temperature detector 8 to the judgment means 14 to heat the heating coil. The power supply to 6 is controlled. Further, the control circuit 13 has a set value composed of a first control temperature set high and a second control temperature set low, and the set value of the first control temperature is used in normal heating, and when the heating is started. At temperature detector 8
When the temperature rise value per unit time of is less than or equal to the preset value, the heating coil 6 is controlled using the set value of the second control temperature. In the figure, 17 is a power supply 17 for supplying electric power
Is. Then, the cooking pot 9 is placed on the plate 1, and a signal for starting heating is output from the operating means 16, whereby the control means 15 supplies a driving current to the heating coil 6 to induction-heat the cooking pot 9.

Next, the operation will be described with reference to FIGS. 2 and 3. That is, when the heating start is input from the operating means 16, the temperature h of the temperature detector 8 is set to h1 and the control circuit 13 is set.
Then, the control circuit 13 supplies a drive current to the heating coil 6 to heat the cooking pot 9. Immediately, the heating time t is measured by using the clock function in the control circuit 13, and if the heating time t exceeds a preset time T (which is set to 10 minutes or less in this embodiment). , The temperature h of the temperature detector 8 is stored as h2 in the control circuit 13, and h2 and h1 are stored.
When the temperature rise value Ha is less than or equal to a preset temperature rise value Ha, the temperature rise value per unit time of the temperature detector 8 at the start of heating is small, so the bottom surface 12 of the cooking pot 9 is warped. The determination means 14 determines that the heating control temperature S
Lower the setting of h by C1. When the difference between h2 and h1 is equal to or higher than the preset temperature increase value Hb,
Since the temperature rise value per unit time of the temperature detector 8 at the start of heating is very large, it is determined that the cooking pot 9 that has been heated in advance is used. Also in this case, the cooking oil easily ignites, and therefore the heating control The setting of the temperature Sh is lowered by C2.
When the difference between h2 and h1 is larger than Ha and smaller than Hb, it is determined that the bottom surface 12 of the cooking pot 9 is flat, and the setting of the heating control temperature Sh is not changed. Heating is continued in this state, and when the temperature h of the temperature detector 8 becomes Sh or higher, the control means 15 stops energizing the heating coil 6 to prevent the cooking oil from igniting. Although not shown, after stopping once,
When the temperature h of the temperature detector 8 becomes equal to or lower than a predetermined temperature, heating can be performed again.

As described above, according to the controller of the heating cooker of the embodiment, the warp of the bottom surface 12 of the cooking pot 9 is determined by the magnitude of the temperature rise value per unit time of the temperature detector 8 at the start of heating. Therefore, erroneous determination of the warp of the bottom surface 12 depending on the amount of cooking oil is eliminated, and the ignition of cooking oil can be prevented. Therefore, even when the bottom surface 12 is largely warped, it is possible to more safely prevent the cooking oil from being ignited.

Further, by using the amount of change of the temperature detector 8 at the start of heating, the cooking pot 9 containing the preheated cooking oil can be judged at the same time as shown in FIG. 3. Ignition can also be prevented.

FIG. 4 shows a second embodiment of the present invention. The difference from the first embodiment is that, in the control method for the ignition of cooking oil, the heating output is controlled while the heating control temperature is set low. That is, the output control is performed only when the preset output is large, and in this embodiment, the output is reset to half of the maximum output only when heating is performed at the output of half or more of the maximum output. There is. Heating is continued in this state, and when the temperature h of the temperature detector 8 becomes Sh or higher, the power supply from the control circuit 13 to the heating coil 6 is stopped to prevent the cooking oil from igniting. Although not shown, the temperature detector 8 can be heated again when the temperature h of the temperature detector 8 becomes equal to or lower than a predetermined temperature.

As described above, according to the control device for the heating cooker of the second embodiment, when the output is large in the state of the cooking pot 9 where cooking oil is easily ignited, the output is controlled to be small. Therefore, it is possible to prevent the cooking oil from igniting by slowing the temperature rise of the cooking pot 9 and improving the temperature followability of the temperature detector 8 with respect to the cooking pot 9. Further, when the cooking oil is easily ignited, the output of heating is lowered, so that the rise in the oil temperature is delayed and the user can easily recognize the abnormality.

In the above embodiment, the temperature rise value per unit time of the temperature detector 8 near the start of heating is substituted with the temperature rise value after the heating time T, but the temperature detector 8 has a constant temperature. You may substitute for the time until it becomes an increase value. Although the heating is stopped when the temperature of the temperature detector 8 becomes equal to or higher than the control temperature Sh, control may be performed to reduce the value of the heating output. Further, the second control temperature is obtained by subtracting a certain value from the first control temperature, but a method of setting a value in advance may be used. Further, although it has an algorithm for detecting a preheated cooking pot, this part may be omitted. Also, what is important in the control to prevent the ignition of cooking oil is the control temperature and heating output until the first heating is stopped, and the control temperature and heating output from the second heating can be changed by different set values. If the temperature rise value per unit time of the temperature detector 8 near the start of heating is less than or equal to a predetermined value,
The control temperature and the heating output may be made smaller than a preset value at least once or for a certain period of time. Furthermore, although an induction heating cooker is used for description, a heating cooker having a halogen heater or the like may be used.

[0017]

As is apparent from the above embodiments, the control device for a heating cooker according to the present invention has two or more control temperature values with different set temperatures in the control circuit, which is high during normal heating. If the temperature rise value per unit time of the temperature detector is less than or equal to a preset value at the start of heating, the heating coil is controlled using the lower control temperature value. With this configuration, it is possible to prevent the cooking oil from being ignited and to maintain the cooking oil temperature rising performance even when a cooking pot having a warped bottom surface is used.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a controller for a heating cooker according to a first embodiment of the present invention.

FIG. 2 is an operation flowchart of the control device.

FIG. 3 is a diagram showing a relationship between a temperature of a temperature detector of the control device and heating time.

FIG. 4 is an operation flowchart of the control device.

FIG. 5 is a sectional view of a conventional heating cooker.

FIG. 6 is a sectional view of a cooking pot placed on the heating cooker.

FIG. 7 is a diagram showing the relationship between the temperature of the temperature detector of the cooking device and the heating time.

[Explanation of symbols]

 6 Heating coil 8 Temperature detector 9 Cooking pot 13 Control circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Abe 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A temperature detector for detecting the temperature of a cooking pot,
And a control circuit for controlling energization to the heating coil based on the signal of the temperature detector, wherein the control circuit has two or more control temperature values having different set temperatures, and is high during normal heating. If the temperature rise value per unit time of the temperature detector at the start of heating is less than or equal to a preset value at the start of heating, the lower control temperature value is used to control the heating coil. A control device for a heating cooker configured to control. 2. A temperature detector for detecting the temperature of the cooking pot,
And a control circuit for controlling energization to the heating coil based on the signal of the temperature detector, wherein the control circuit has two or more heating output values having different set outputs, and is high during normal heating. If the temperature rise value per unit time of the temperature detector at the start of heating is less than or equal to a preset value at the start of heating, the lower heating output value is used to drive the heating coil. A control device for a heating cooker configured to control.