JPH0257412B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a general-purpose heating cooker such as a stove, and controls the cooking temperature appropriately so that rice can be cooked well even if the type of pot or the amount of rice to be cooked changes. It is related to cooking utensils.

Conventional configuration and its problems Conventionally, to cook rice, a special pot was used, and the temperature was set to an appropriate temperature by correlating the temperature of a temperature sensor that came into contact with the bottom of the pot with the temperature of the food (cooked rice). However, even if you tried to cook rice with a general-purpose cooker like a stove, you would have to change the pot or the amount of rice cooked would change greatly. Because of these large degrees of freedom, it has been difficult to properly control the temperature of the rice, making it difficult to cook delicious rice.

Purpose of the Invention The present invention provides a cooker that can cook rice well even if the type of pot or the amount of rice cooked changes when cooking rice in a general-purpose cooker such as a stove that detects the temperature at the bottom of the pot. With the goal.

Structure of the Invention Therefore, when rice cooking is selected by a switch, the cooking device of the present invention detects the slope of the temperature rise of the contents during rice cooking, and determines the internal temperature by determining the bending point according to the slope. Not only can it reliably detect the point at which the rice has boiled, but it can also continue to heat and cook the rice, and if it reaches a predetermined temperature higher than the temperature at which boiling was detected, it will stop heating and control the cooking temperature. The configuration is such that it is possible to do so.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 shows an external view of an example in which the present invention is applied to a gas stove, in which 1 is a gas stove box, a trivet 2 on which a rice cooking pot 14 is placed, and a burner 3.
Further, 4 is a temperature sensor that protrudes from the center of the burner 3 and detects the temperature by contacting the bottom surface when the rice cooking pot 14 is placed on the trivet 2. Also, on the front side, there is a temperature sensor that detects the temperature when the rice cooking pot 14 is placed on the trivet 2. a knob 5 for changing the temperature, a knob 6 for changing the temperature, an indicator lamp 7, a notification buzzer 8, and
It has a stove or rice cooking switch 9. Furthermore, it has a gas connection port 10 and a dry battery 11 on the side.

FIG. 2 is a diagram showing an example of the control system of the present invention, in which gas passes from the gas connection port 10, through the gas tank 12, and the proportional control valve 13, and is combusted in the burner 3. The burner 3 heats the bottom of the rice cooker 14 and adds heat to the contents 15.

The temperature signal from the temperature sensor 4 is transmitted to the tilt detection section 17 inside the boiling detection section 16 if the changeover switch 9 is set to the rice cooking side. Tilt detection section 17
detects the temperature increase slope Tw of the bottom of the pot 14, and calculates the bending value Tu from the slope Tw.

Reference numeral 18 denotes a bending point detection unit, which detects a bending point C at which the temperature gradient ΔT is smaller than the bending value Tu when the bending value Tu is determined by the inclination detecting unit 17.

19 is a temperature determination section, and a bending point detection section 18
A determination is made as to whether or not the bending point C is higher than the temperature Te obtained by adding a predetermined temperature α to the detected temperature Td. 20 is attached to the temperature determination section 19, and a temperature
The temperature changing section 21 is configured to change Te.
The heat quantity control section drives the proportional control valve 13 to control the burner 3.
increase/decrease or stop the amount of combustion.

The initial heat amount setting section 22 and the heat amount changing section 23 are attached to the heat amount control section 21, and heat with the heating amount set by the initial heat amount setting section 22 at the same time as ignition, and when the bending point detection section 18 detects the bending point C. Heat amount control section 23
Reduce the amount of heating. Then, the temperature determination section 19
When the temperature Te is reached, the heating is stopped by the heat amount control section 21, the notification section 24 is activated, and the display lamp 7 and notification buzzer 8 are configured to notify the user. Note that when the bending point detection section 18 detects the bending point C, there is no problem even if the heating is performed with the heating amount set in the initial heat setting section 22 without omitting the heat amount changing section 23 and reducing the heating amount. The amount of heat can also be set by the amount of heat changing section 23 according to the temperature increase slope of the inclination detecting section 17. That is,
If the temperature gradient is large, the amount of rice to be cooked is small and the amount of heating can be reduced, and if the temperature gradient is small, the amount of rice to be cooked is large and the amount of heating can be set to a large value, making it possible to cook rice over a wide range.

On the other hand, if the changeover switch 9 is set to the stove side, when the temperature of the temperature sensor 4 reaches the temperature set by the temperature change unit 20, the temperature determination unit 19 is activated.
The proportional control valve 13 is driven by the heat amount control section 21 to proportionally control the combustion amount of the burner 3, and the notification section 21 notifies the burner so that it can be used as a normal temperature control stove.

In the present invention, even if the type of rice cooking pot 14 or the amount of rice cooked 15 changes, as long as the temperature of the water put inside boils,
It is configured to detect the bending point C of the slope of the pot bottom temperature, paying attention to the fact that the temperature does not rise any further until the water runs out, and the temperature rise at the bottom of the pot also decreases.

FIG. 3 shows a characteristic diagram explaining the control operation state, where the horizontal axis X is time, the vertical axis T of characteristic A is temperature, the broken line A is the temperature at the bottom of the contents 15, and the solid line B is based on the temperature sensor 4 at the bottom of the pot. Indicates temperature characteristics. The vertical axis of characteristic B indicates the control current of the proportional control valve 13, which is proportional to the combustion amount of the burner 3.

The temperature Ta is at room temperature, and both curves A and B increase when heated by the heating amount set by the initial heat amount setting section 22. Although the temperature rise in the initial stage of heating is unstable,
Eventually, the temperature rises from the temperature Tb in a constant and stable manner according to the amount of the contents 15. This temperature Tb is 75~
It is 80℃. As the temperature continues to rise further, the temperature Tc becomes
The temperature is 100℃, and the content 15 bottom A boils to 100℃.
It will no longer rise above this level. However, contents 1 at this time
The temperature from the center to the top of 5 is because there is little convection.
The temperature gradually rises from below 100℃ until it reaches 100℃. When the temperature Tc is reached, the sensor temperature B is Td, and this temperature Td also increases very little from the point where the bottom A of the contents 15 reaches 100°C, but sometimes it disappears. Here, the temperature difference between the temperature Tc point 100℃ and Td is determined by the type (material and thickness) of the rice cooker 14 and the amount of rice cooked 15
There is a large variation due to However, the inflection point C at which the temperature increase slope ΔT changes is always after the content 15 has boiled from the bottom A.

Here, the tilt detection section 17 of the boiling detection section 16 is
At the point where the temperature rise exceeds the stable temperature Tb, measure the slope Tw of the temperature rise of ΔXA for a certain period of time, and use this slope Tw as a function to calculate the calculation constant K,
The bending value Tu is calculated from Tu=K·Tw−L, and the bending point detection unit 18 determines the bending point C at which the temperature gradient ΔT is smaller than the bending value Tu.

The operation of this bending point detection section 18 will be explained with reference to FIG. Until the time Xd when the bending point detection section 18 detects the bending point C, the heating amount is the heating amount of the proportional control valve current a set by the initial heat amount setting section 22. When the bending point C is detected, the heat amount changing unit 23 reduces the heating amount to the proportional control valve current b to slowly heat the contents 15. When the bending point C is detected, no problem will occur even if the heat amount changing unit 23 is omitted and the proportional control valve current is heated as it is at a without changing it to b.

Gradually, if the entire content 15 is sufficiently heated and boiled, the moisture will eventually disappear and the bottom temperature of the content 15 will be A.
begins to rise above 100°C, and sensor temperature B also rises accordingly. At time Xe, temperature determination section 1
9, when the temperature Te (Td+α), which is the sum of the temperature Td at the bending point C and the predetermined temperature α, is reached, the heating is stopped by stopping the proportional control valve current, and the notification unit 24 is activated as shown in FIG. 3C. The completion of rice cooking is notified by turning the buzzer signal on and off. Here, it is also possible for the user to adjust the temperature Te by increasing or decreasing the temperature Te using the temperature changing section 20 so as to obtain the desired degree of scorching.

The contents 15 are sufficiently cooked between the temperatures Td and Te, and the temperatures A and B gradually decrease as heating is stopped.

FIG. 4 is a diagram showing an example of inclination detection and bending point detection of sensor temperature 2. The temperature is detected by the tilt detection section 17.
If the temperature gradient Tw at a fixed time interval ΔXA is measured from Tb and the bending value Tu is calculated, the temperature T _on at every sampling time ΔX enters the bending point detection section 18.
The temperature gradient ΔT is measured sequentially from ~T _o , and when the temperature gradient ΔT becomes less than the bending value Tu, the point Xd is determined to be the bending point C, and the temperature at which the bottom of the contents 15 becomes 100°C is determined. This is a method to do so.

As described above, when using a microcomputer in the control system, all control sequences are stored in a fixed memory (ROM), and the bending value Tu is stored in a writable and readable data memory (RAM). It is programmed in advance so that the bending point temperature Td, etc. are stored in memory.

In the above configuration, the slope Tw of the temperature rise of the contents 15 is measured by the slope detection section 17 of the boiling detection section 16 and the bending point detection section 18, and the bending point C is determined by calculating the bending value Tu according to the slope Tw. By detecting this, even if the type of rice cooker 14 or the amount of cooked rice in the contents 15 changes, the temperature of the contents 15 will be kept at exactly 100°C.
Furthermore, when the temperature determination unit 19 reaches a temperature Te obtained by adding a predetermined temperature α to the temperature Td at the bending point C, the temperature control unit 21 controls the heating of the burner 3. Since it is designed to stop, stable rice cooking is always possible under any conditions.

In addition, the heat amount changing unit 23 reduces the power of the burner 3 at the temperature Td at which the bending point C is detected, allowing for slow cooking or reducing the amount of heating depending on the amount of rice to be cooked, so that good rice can be cooked.

Furthermore, the temperature determination unit 19 determines the temperature Td at the bending point C.
By adjusting the temperature Td obtained by adding a predetermined temperature α to the temperature Td using the temperature changing unit 20, it is possible to adjust the degree of scorching to suit the user's preference.

Furthermore, the changeover switch 9 makes it possible to provide a highly convenient cooking device that can cook rice and can also be used as a normal gas stove with temperature control.

Effects of the Invention As described above, the cooking device of the present invention provides the following effects.

(1) By installing a temperature sensor in a general-purpose cooker like a stove, it is possible to adjust the temperature to suit the cooking content, and if you select rice cooking with the selector switch, the pot and amount of rice cooked will be constant on the stove. It is possible to cook rice under conditions with a high degree of freedom.

(2) By measuring the slope of the temperature rise of the contents using a temperature sensor and detecting the bending point by calculating the bending value according to the slope, it is possible to detect that the temperature of the contents has reached boiling. The system is configured to stop heating and start cooking when the temperature rises by a predetermined amount, so regardless of the type of rice cooker or the amount of rice cooked, the temperature can always be controlled at a constant level, resulting in delicious and delicious rice. .

(3) The method for detecting inclinations and bending points is to obtain the difference in sensor temperature by sampling at fixed time intervals, and the system can be easily configured by controlling with a microcomputer, etc.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the cooking device of the present invention applied to a gas stove, Fig. 2 is a control system diagram thereof, and Fig. 3 A, B, and C are characteristic diagrams illustrating control operation states of temperature control. , FIG. 4 is a characteristic diagram illustrating the detection states of the inclination detection section and the bending point detection section. 3... Burner (heating means), 4... Temperature sensor (temperature detection means), 13... Proportional control valve (heating control means), 14... Rice cooking pot, 16... Boiling detection section,
17...Inclination detection section, 18...Bending point detection section, 1
9...Temperature determination section, 20...Temperature change section, 21...
...heat control unit, Tw...tilt, Tu...bending value,
ΔT...temperature gradient, C...bending point, Td...bending point temperature, Te...temperature higher than the bending point temperature by a predetermined temperature, α...predetermined temperature.

Claims (1)

[Scope of Claims] 1. A heating means for heating a rice cooker, a temperature detecting means for detecting the temperature by contacting the rice cooker, a heating control means for controlling the heating amount of the heating means, and the temperature detecting means. It has a heat amount control unit that outputs a control signal to the heating control means in response to a signal, and a changeover switch that selects according to the cooking content, and when the changeover switch selects rice cooking, the temperature detection means determines whether the rice is cooked or not. It has a boiling detection section consisting of an inclination detection section that detects the temperature rise slope of the pot and calculates a bending value from the inclination, and a bending point detection section that further detects a bending point where the temperature slope becomes smaller than the bending value, A temperature determining unit is provided for determining that the heating of the heating means has reached a temperature higher than the temperature at which the bending point was detected by the bending point detection unit by a predetermined temperature, and the amount of heat is controlled based on the output of the temperature determining unit. A cooking device that is configured to stop heating depending on the part. 2. Claim 1 in which the temperature changing unit can change the temperature higher by a predetermined temperature than the temperature at which the bending point detection unit in the temperature determining unit detects the bending point.
Cooking device described in section. 3. The cooking appliance according to claim 1, wherein the heating amount of the heating means is reduced based on the detection of the bending point by the bending point detection section. 4. The heat amount control section changes the heating amount of the heating means after the bending point is detected by the bending point detection section, in accordance with the temperature increase slope detected by the slope detection section, by the heat amount changing section. Cooking device.