JPH01109687A - Temperature adjusting device for heated cooking utensil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to a temperature control device for a cooking device that heats a pot or the like for cooking.

Conventional Technology Conventionally, when cooking tempura with this type of heating cooker, if the amount of oil used is small, the oil temperature will rise rapidly before the device's temperature control function operates, causing oil to ignite. has been established.

Hereinafter, a conventional temperature control device with an overheating prevention function will be described in the case of an induction heating cooker.

First, the temperature control device will be explained with reference to FIGS. 4 and 6. 1 is a heat-sensitive element such as a thermistor, and the object to be heated 2
The temperature of the heated object 2 is detected via the top plate 3, which is pressed against the lower surface of a top plate 3 made of an insulating material such as ceramic on which the heated object 2 is placed. The thermistor 1 and a resistor 4 constitute a temperature detection device 5, and the output of this temperature detection device 6 is input to a MU/D converter 6. 7 is a timer device which starts operating when the device starts heating. The output of the timer device 7 is input to the overheating prevention level setting means 8, and this output and the output of the temperature control level setting device 9, which consists of several touch keys, are compared by the level comparison means 10, and whichever is higher is compared. The set level and the output from the MU/D converter 6 are input to the temperature control means 11. The temperature control means 11 compares the thermistor temperature "th" output from the MU/D converter 6 with the final temperature control level "1evel" determined by the level comparison means 1o, and calculates half of the amplitude during temperature control. am (medium 1°C)
As, Tth-. 7°, if ≧T0, oscillation is stopped (temperature control is 0FF), and if Tlevel -Tth≧Tam, oscillation (temperature control is ON) is output.A duty signal is output to the inverter drive circuit, and upon receiving this signal, the inverter is driven. The circuit 12 performs duty control on an inverter circuit 13 and a heating coil 14 that heats the object 2 to be heated. Further, the temperature control means 11 calculates the total time t of the OFF signals. 2. When reaching a predetermined time tN, a signal is output to a notification circuit 16 made up of display elements such as LEDs to light up the display elements.

In addition, 6~8,! :10 and 11 are devices built into a 1-chip microcomputer. Next, according to Figure 6,
The overheating prevention level set by this temperature control device will be explained.

When the user of the device turns on the input switch (not shown) and sets the temperature control level "set" using the temperature control level setting device 9, the device oscillates and at the same time the timer device 7 starts counting. Depending on the input, the overheating prevention level setting means 8 sets the temperature control MAX setting level T11 □ Eyorimo high level Tl1 until 11 hours after the device oscillates.
From tl to t2, set the level to Tl1m1t2, which changes linearly with the heating time, and after 12 hours, set it to the level T11□t3, which is lower than the temperature control MAY setting level "set□t". There are three levels of settings.

Problems to be Solved by the Invention However, in such an overheating prevention level setting method, if the temperature of a small amount of oil rises rapidly, duty control is performed at an overheating prevention level Tl1m1t' that is higher than the temperature control MAX setting level. starts, so there is no need to worry about oil igniting, but when cooking continuously, the temperature of thermistor 1 will be quite high by the time the first cooking is finished and the input switch of the device is turned off. Temperature detection device 5
The output of Repe 1 is lower than the overheating prevention level T 1.
m1t le. Therefore, when the user turns on the input switch of the device to heat the low-temperature oil again, until the output level of the temperature detection device 5 rises to the overheating prevention level T1□mit', that is, until the temperature of the thermistor 1 becomes considerably low. There was a problem in that the second cooking process was not possible because the equipment remained stopped heating.

Therefore, in view of the above problems, the present invention changes the initial overheat prevention level setting according to the initial thermistor temperature at the start of cooking, so that even when continuous cooking is performed, the overheat prevention function is activated at the start of the second cooking. The purpose is to enable the user to continuously perform temperature-controlled cooking without operating the device.

Means for Solving the Problems In order to achieve the above object, the temperature control device for a heating cooker of the present invention measures the temperature from the initial temperature detection device, and if the temperature is lower than a predetermined temperature, If the overheating prevention level is set to a low level like the conventional one, and the temperature is higher than the set temperature, the overheating prevention level is set to a high level from the beginning.

Effect With the above configuration, when cooking with a small amount of oil from a low initial temperature, the oil temperature is set to a low level as in the past, so the oil temperature rises rapidly and the temperature detection device cannot follow the oil temperature. Even if the temperature is poor, the overheating prevention device is activated early, so there is no need to worry about the oil catching fire. In addition, in the case of continuous cooking, the temperature of the temperature detection device is higher than the set temperature immediately after the first cooking, so the overheating prevention level is increased and the heating operation can be continued for the second cooking. It is.

EXAMPLE Hereinafter, an example of the present invention will be explained in the case of an induction heating cooker with reference to FIGS. 1, 2, and 3.

First, the configuration of a temperature control device with an overheating prevention function for an induction heating cooker according to this embodiment will be explained with reference to FIG. 16 is a thermistor, and a top plate 18 on which the heated object 17 is placed.
The temperature detection device 20 detects the temperature of the object to be heated 17 through the top plate 18 and is connected to the bottom surface of the resistor 19.
It consists of The output of this temperature detection device 20 is A/
The temperature detection device 20 has a configuration in which the temperature is inputted to a D converter 21, and the configuration of this temperature detection device 20 is the same as that of the conventional example. However, in the embodiment of the present invention, the output of the A/D converter 21 is first inputted to the initial thermistor temperature comparison means 22, and this output allows the overheating prevention level setting means 23 to control the overheating based on the output of the timer device 24. A constant overheating prevention level is set regardless of the prevention level or the output of the timer device 24, and the overheating prevention level set by the overheating prevention level setting means 23 is set to 11°□, and the temperature is set using several touch keys. Temperature control level Ts set by the control level setting device 25
6t is the level compared by the level comparison means 26, whichever is lower is determined by the temperature control means 27 as the temperature control level T1゜7.
．． Input as 1. The configuration of the temperature control processing means described below is the same as the configuration explained in the conventional example, and the total output of the MU/D converter 21, the thermistor temperature Tth, and the level comparison means 2
The entire output of e and the final temperature control level "lev.1" are compared by the temperature control means 27, and half of the amplitude during temperature control is set to "1m (
As part 1'c), the inverter drive circuit 28
is an inverter circuit 29 and a heating coil 3 that completely heats the object to be heated by the high frequency current supplied from the inverter circuit 29.
An alarm circuit 3 which controls the duty of o and also consists of an LED.
1 is the sum T of the processed signal from the temperature control means 27, that is, the OFF signal. In response to a signal indicating that f has reached the predetermined time TN, the LEDi is turned on to ensure that the temperature of the contents of the heated object 1 reaches the set temperature desired by the user of the device within the tolerance range. I'll let you know everything I've reached. In addition,
21 to 24 and 28 and 27 are devices built into a one-chip microcomputer.

Next, the operation of the temperature control device in the example will be explained with reference to FIGS. 2 and 3. Initial temperature of thermistor 16 "t"
If ho is determined to be lower than the branch temperature Td by the mister temperature comparing means 22, the overheating prevention level setting means 23 reads the output of the timer device 24 and starts the device oscillation, as in the conventional case. From to branch time t1, the overheat prevention level is set at a level Tl1m1t' which is considerably higher than the temperature control MAX level set by the temperature control level setting device 25. In this case, as in the conventional example, the overheating prevention level from branch time t to branching time t2 is the above-mentioned "overheating prevention level" that changes linearly from 11m1t1 to oscillation elapsed time t, and 11+it2 is the output of the timer device 24. The overheating prevention level setting means 23 performs arithmetic processing and sets the level. After the branch time t2, the temperature control MAX level is set to a constant level "11m1t3" which is lower than the MAX level.On the other hand, as in the case of continuous cooking, the initial temperature Ttho of the thermistor 16 is set to the branch temperature Td.
If the initial thermistor temperature comparison means 22 determines that the temperature is higher than The overheating prevention level T is not constant. Initialize it to it3. Therefore, while the thermistor temperature Tth is high, the temperature is adjusted again.
Even when cooking is performed near the AX level setting, the device will not continue heating until the thermistor temperature Tth drops to a certain degree, and the thermistor temperature "th"
The device continues heating until the temperature reaches the predetermined temperature control level.

More than the effects of the invention, as is clear from the examples, according to the present invention, by switching the overheating prevention level of the equipment according to the initial temperature level of the temperature detection device, the conventional overheating prevention function against oil ignition can be maintained as before. It is possible to maintain detection performance and enable continuous cooking of the device.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a temperature control device in an embodiment of the present invention,
FIG. 2 is a flowchart showing the operation of the microcomputer, and FIG. 3 is a characteristic diagram of the overheat prevention level and thermistor temperature change in the same device. FIG. 4 is a block diagram of a conventional temperature control device, FIG. 5 is a flowchart showing the operation of the same microcomputer, and FIG. 6 is a characteristic diagram of the overheat prevention level and thermistor temperature change in the same device. 16... Thermistor, 20... Temperature detection device, 22... Initial thermistor temperature comparison means, 23... Overheating prevention level setting means, 27...
...Temperature control means. Name of agent: Patent attorney Toshio Nakao and 1 other person16
- Thermistor η - Temperature control + throw Fig. 1 Fig. 3 Fig. 1 te 2 Battle ■ Fig. 4

Claims (1)

[Claims] a temperature detection device for detecting the temperature of the object to be heated; a temperature control means for controlling the temperature of the object to be heated to a predetermined stable temperature; and an output of the temperature detection device that reaches a predetermined overheat prevention operation level. Then, the overheat prevention means stops heating the heating element or switches to duty control, and the overheat prevention means switches to at least two overheat prevention operation levels depending on the initial output signal level from the temperature detection device. A temperature control device for a heating cooker.