JPS6131819A - Controlling device for heating for cooker - Google Patents

Abstract

PURPOSE:To make it possible to detect boiling when required by a user, by controlling the passage of electric current to heating means based on the output of a timer after the gradient of temperature rise of water temperature in a container has reached a predetermined value. CONSTITUTION:When water heating operation is started, the input from a current amount setting means 14 is switched to the input from a time adjusting means 11. The gradient of temperature rise is determined by a gradient detecting means 8 on the basis of the output signal of a temperature detecting means 7 including a temperature sensing element 6 for detecting water temperature in a container 4. When a judging means 9 judges that the boiling point has been attained based on the change in this gradient value, a timer 10 is actuated. The delay time of the timer 10 is the time required by a user based on the input signal from the time adjusting means 11. When the operation of the timer 10 is completed, it is informed by a buzzer 17, and switching to the input from the current amount setting means 14 is made.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a heating control device for a cooking device such as an electric stove that heats a pot or kettle. ○Conventional structure and problems thereof Generally, the bottom temperature of the pot is detected by a sensor. However, a heating control device is known that detects the boiling point from the temperature increase gradient, notifies the boiling point with a buzzer, etc., and controls the energization of the heating means. However, the correlation between the temperature of the bottom of the pot and the temperature of the water will naturally vary depending on the pot. As shown in Figure 1, an aluminum pot 1. Enamel pot 2. The difference between stainless steel pot 3 and the bending point of the pot bottom temperature, which corresponds to the boiling point of water, is 1. ．． 12.13
and became dog-like. In fact, in a device that detects boiling when the temperature increase gradient becomes as small as %, there is a deviation in the boiling detection point as shown in the table below. Although this value satisfies the ability of the device to provide a buzzer to notify the user that boiling has been detected after the water has definitely boiled, it is unsatisfactory from the user's perspective.

Generally, when boiling water at home, most of the pots used are fixed, so in households using aluminum pots, the buzzer always sounds 10 seconds after boiling, and in households using stainless steel pots, the buzzer always sounds 50 seconds after boiling. It takes a few seconds for the buzzer to finally sound.0Also, users have different ways of thinking about boiling.
(C) It is necessary to completely sterilize the product by boiling it for 3 to 5 minutes.The uniform boil detection method did not give the user a sense of satisfaction.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a heating control device for a cooker that performs a boiling detection operation according to the pot used by the user and at a time desired by the user. It is something to do.

Structure of the Invention In order to achieve the above object, the heating control device for a cooker of the present invention includes a heating means for heating a container such as a pot, and a thermistor or the like that is brought into pressure contact with the bottom of the container and indirectly detects the water temperature inside the container. Temperature detection means that includes a temperature sensing element as a part; gradient detection means that measures a temperature increase gradient based on the output signal of the temperature detection means; and judgment that determines the boiling point based on the gradient value measured by the gradient detection means. a timer that starts with the output of the determination means; a time adjustment means that adjusts the time of the timer; and an energization control means that uses the output of the timer as a boiling detection output to control energization of the heating means;
It consists of a drive means that directly drives the heating means with the output of the energization control means, and an energization amount setting means that sets the energization amount after the output of the timer. Based on the input, the drive means controls the energization of the heating means via the energization control means, and boiling can be detected according to the type of pot and at a time desired by the user. It is.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 2, the heating control device for a cooker of the present invention includes a heating means 6 such as a heater that heats a container 4 such as a pot or kettle, and a heating means 6 such as a heater that heats a container 4 such as a pot or a kettle, and a heating means 6 that is brought into pressure contact with the bottom surface of the container 4 by a means such as a spring. 4, a temperature sensing element 6 such as a thermistor that detects the water temperature inside the temperature sensor 4, a temperature sensing means 7 that includes the temperature sensing element 6, and a gradient that measures the temperature increase gradient based on the output signal of the temperature sensing means 7. A detecting means 8, a determining means 9 for determining the boiling point based on a change in the gradient value measured by the gradient detecting means 8, a timer 10 started by the output of the determining means 9, and a timer 10 for adjusting the time. a time adjustment means control means; an energization control means 12 that uses the output of the timer 1o as a boiling detection output to control energization of the heating means 5; and a relay that directly drives the heating means 5 with the output of the energization control means 12. Alternatively, it comprises a driving means 13 consisting of a bidirectional sirisk and its gate circuit, etc., and an energization amount setting means 14 for setting the energization amount after the output of the timer 10, and after the output of the timer 1°, the energization amount setting means The driving means 13 controls the heating means 5 via the energization control means 12 based on the input signal from the heating means 14.
Controls energization to. Further, during the boiling detection operation, the input from the time adjustment means control means of the timer 10 is valid;
After the operation of the timer 10, that is, after the boiling detection operation, the input switching means 1 between the time adjustment means 1, 1 and the energization amount setting means 14 makes the input from the energization amount setting means 14 valid.
5, and this input switching means 16 operates based on the output of the timer 10.The zero slope detection means 8, the judgment means 9, the timer 10, and the energization control means 12 are functions built into the one-chip microcomputer 16. It is. It also has the function of sounding a piezoelectric buzzer 17 using the output of the timer 10 to notify the boiling detection point.

Next, a specific example of the present invention will be explained based on the circuit diagram of FIG. When the power switch 18 connected to the AC power supply 42 is turned on, a voltage is applied to the DC power supply circuit 19 to form a DC power supply, and an AC voltage is applied to the series circuit of the bidirectional thyristor 20 and the heater 21 which is the heating means 6. is applied. A one-chip microcomputer 16 containing the gradient detection means 8, judgment means 9, timer 10, and energization control means is connected to this DC power supply, and the microcomputer 16 is connected to a DC circuit for the DC power supply. A connection point between the key switch 22 and the resistor 23 is connected. This key switch 22 and the resistor 23 form an automatic water boiling start means 24, and this key switch 22
By pressing , a high potential is transmitted to the microcomputer 16 and the water boiling operation is started. The temperature sensing element 6 also forms a DC circuit for the DC power supply.
The temperature detecting means 7 is composed of the thermistor 26 and the resistor 26.
The potential at the connection point is converted into a digital signal via the A/D converter 27, and the digital signal is manually input to the microcomputer 16. Also, a time adjustment means control means which has a resistor 28 and a volume 29 connected in series to a DC power supply, and an energization amount setting means 1 which has a resistor 3o and a volume 31 connected to a DC power supply in series.
The outputs of 4 and 4 are grounded by a resistor 34 through diodes 32 and 33, respectively, to determine the voltage level and to
The signal is input to the microcomputer 16 via a D converter 36. Further, the output from the microcomputer 16 is connected to the anode of the diode 33 via the diode 4o, and the same output is connected to the anode of the diode 32 via the inverter 36 and the diode 41. The input switching means 15 of the A/D converter 35 is formed by combining the diodes 32, 33°40.41, the resistor 34, and the inverter 36. By this switching, it is switched whether to transmit the input from the time adjustment means control means of the timer 10 to the microcomputer 16 or the input from the energization amount setting means 14 to the energization control means 12. The output of the microcomputer 16 drives the piezoelectric buzzer 17, the transistor 38 is driven via the current limiting resistor 37, and the bidirectional thyristor 20 is driven by the transistor 38 via the current limiting resistor 39. .

The driving means 13 is formed by the resistors 37, 39, the transistor 38, and the bidirectional thyristor 2o.Next, the operation of the circuit diagram of this embodiment will be explained with reference to the flowchart of FIG. 4. The power switch 18 is turned on,
When the key switch 22 is pressed in step 1, the water boiling operation starts, and in step 2, the energization amount is automatically set to the maximum full power, and in step 3, the input from the energization amount setting means 14 (Wattcon input ) to the input from the time adjustment means control means (manual delay timer).

In FIG. 3, when there is no Low output from the microcomputer 16, the input level from the energization amount setting means 14 is reduced to Low at the anode of the diode 33, and the input signal from the time adjustment means control means is passed through the diode 32. ,A
It is transmitted to the microcomputer 16 via the /D converter 35. Next, in step 4, the first temperature gradient is detected,
In step 5, a second temperature gradient is detected, and in step 6, the ratio of the temperature gradients is determined. The operations of steps 4 to 6 affect the gradient detecting means 8 described above. If it is determined that the predetermined slope has been reached, then in step 7 the timer 10 is activated. At this time, the delay time of the timer 10 is a time based on the input signal from the time adjustment means control means. When the operation of the timer 1Q is completed, a buzzer indicating the end is issued in step 8, and in step e, the input from the time adjustment means control means (delay timer manual input) and the input from the energization amount setting means 14 (wattcon input) are input again. can be switched to In FIG. 3, a high output is made from the microcomputer 16, and the input level from the anode of the diode 32 and the time adjustment means control means is reduced to low through the inverter 36.
In FIG. 3, when the input switching means 16 is not used, there is a One more A/D converter is required, and one more input port of the microcomputer 16 is also required.

Effects of the Invention As described above, according to the present invention, the boiling detection time can be arbitrarily changed using an external timer. The time shown in the table above indicates the boiling detection point when the temperature rise gradient tag of the water temperature reaches %, but if you change the detection method to gradient detection such as %, the boiling point will be lower than the boiling point. You can choose a slightly earlier boil detection point. By adding a timer to this, any boiling detection point around the boiling point can be selected. As a result, hemorrhoid users can perform any boiling detection operation that suits the pots of each household or according to their preference. Furthermore, by introducing the input switching means, the input from the time adjustment means necessary during the water boiling operation and the input from the energization amount setting means necessary after the water boiling operation are switched and used, thereby reducing the number of input ports of the microcomputer. This has the effect that the number of A/D converters can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a water boiling characteristic diagram of various pots, Fig. 2 is a block diagram showing an embodiment of the device of the present invention, Fig. 3 is a circuit diagram of an embodiment of the device, and Fig. 4 is an operation flowchart of the device. It is. 5... Heating means, 6... Temperature sensing element, 7
...Temperature detection means, 8...Gradient detection means, 9...
・Judgment means, 10... Timer, control means・
... Time adjustment means, 12 ... Current supply control means, 13 ... Drive means, 14 ... Current supply amount setting means, 15 ... Input switching means, 16・・・・・・
・Microcomputer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Courtesy □ Shout out

Claims (2)

[Claims] (1) A heating means for heating a container such as a pot, a temperature detecting means that includes a temperature sensing element such as a thermistor that is brought into pressure contact with the bottom of the container and indirectly detects the water temperature inside the container, and this temperature detecting means a gradient detection means for measuring the temperature increase gradient based on the output signal of the gradient detection means, a judgment means for judging the boiling point based on the gradient value measured by the gradient detection means, a timer started by the output of the judgment means, and a timer for starting the timer. a time adjustment device that adjusts the time; and an energization control device that uses the output of the timer as a boiling detection output to control energization of the heating device;
It consists of a drive means that directly drives the heating means with the output of the energization control means, and an energization amount setting means that sets the energization amount after the output of the timer. A heating control device for a cooking appliance that controls energization of the heating means by the drive means via the energization control means based on an input. (2) Input switching between the time adjustment means and the energization amount setting means so that the input from the time adjustment means of the timer is valid during the boiling detection operation, and the input from the energization amount setting means is valid after the boiling detection operation A heating control device for a cooker according to claim 1, comprising means.