JPS62248926A - Temperature controller for cooking - Google Patents

Abstract

PURPOSE:To eliminate a cooking failure and to prevent an erroneous action by providing means for detecting the temperature of a food to be cooked and a temperature control portion, further providing an graclient detecting portion for detecting the gradient of the rise in the temperature of the food to be cooked and a band point detecting portion, and controlling the amount of heating based on a boiling detection signal. CONSTITUTION:A gas passes through a proportional control valve 2 and burns in a burner 3 to heat the bottom part of a pan 4 and to heat a food 5 to be cooked contained therein. A signal from a temperature sensor 6 is transferred to a temperature control part 7. The temperature control portion 7 actuates the proportional control valve 2 constituted therein of an gradient detection portion 8, a bend point detecting portion 9, and a proportional control pant 10 to thereby control the quantity of combustion of the burner 3. Thus, even when the relationship between the temperature of the food to be cooked and the temperature of the sensor is not constant, that is, the thickness of the pan and the material quantity thereof vary, the correct detection of the boiling point becomes possible by detecting the irregularity of the sensor and the temper ature of the pan bottom.

Description

Detailed Description of the Invention Go to 2 - Industrial Field of Application The present invention provides a method for precisely controlling the humidity of the food to be cooked at a constant level when cooking with a high moisture content, such as stewing, using a heating cooker such as a stove. The present invention relates to a cooking temperature control device that makes it possible to

BACKGROUND OF THE INVENTION Traditionally, stews and other stews require heating at high heat initially, and then boiling the contents over low heat for a long time once the contents have boiled. Up until now, these operations had been done by hand, so there were many mistakes, such as forgetting to turn down the heat even when the water was boiling, resulting in burnt food. Moreover, in this case, energy is wasted.

Therefore, an automatic control device that detects the temperature of the contents and automatically reduces the heat when the contents boil is being considered. However, inserting a temperature sensor into a cooking pot to detect the temperature of the contents is inconvenient and unsanitary.

For this reason, a method has been developed in which a temperature sensor is brought into contact with the bottom of a cooking pot to detect the bottom temperature and to infer the temperature of the contents.

3A - Problems to be Solved by the Invention However, this method has the disadvantage that the humidity at the bottom of the pot and the temperature of the contents are not constant and vary depending on the material shape, thickness, amount of contents, etc. of the pot.

For example, as a conventional control means, a sensor 6 as shown in FIG.
There is a structure in which a signal is directly introduced into the proportional control section 10, and a drive signal for the proportional control valve 2 is outputted thereby.

FIG. 5 is a diagram of the control system of a gas staple stove. Reference numeral 1 indicates a gas inlet, and gas passes through a proportional control valve 2 and is combusted in a burner 3. The burner 3 heats the bottom of the pot 4 and adds heat to the food 5 to be cooked. Reference numeral 6 denotes a temperature sensor that detects the bottom surface temperature of the pot 4, and this signal is input to the proportional control section 10, which drives the proportional control valve 2 to control the combustion amount of the burner 3.

With the above configuration, when the signal from the sensor 6 is lower than the set temperature of the proportional control section 10, the proportional valve 2 is fully opened and the burner 3 is at maximum combustion. As the temperature of the sensor 6 rises and approaches the set temperature, the proportional valve 2 gradually begins to throttle and the amount of combustion is also throttled. When the temperature of the sensor 6 reaches the set humidity, the proportional valve 2 is throttled down to the minimum, and the burner 3 reaches the minimum combustion amount that allows safe combustion.

In this case, there is no problem as long as the correlation between the temperature of the sensor 6 and the temperature of the food 5 is constant. However, it is difficult to correlate the temperature of the sensor 6 and the humidity of the food 5 because the pot and the amount of adjustment vary depending on the food to be cooked.

Especially in stew dishes, the temperature at which the inside boils, that is, the timing to reduce the heat after boiling, is when the temperature of the contents reaches 100 degrees Celsius if the atmospheric pressure is 1 atm. When the set temperature is reached, the temperature of the contents will never reach the set temperature (because water does not rise above 100°C at 1 atm), the proportional valve 2 will not work and the firepower will not be reduced. On the other hand, if the temperature is too low, the heat will be turned down before the temperature reaches 100 degrees Celsius, and the water will have to be heated on low heat thereafter, so it will not come to a boil easily, so a very precise temperature setting is required. Furthermore, temperature control becomes impossible when considering the above-mentioned variations depending on the pot and the amount of food to be cooked.

5-7 In addition to this, if the boiling point of water changes, it becomes impossible to detect the boiling point using conventional control methods.

For example, when cooking using a pressure cooker, the internal pressure rises to a boiling temperature of 120 to 130°C, but it does not boil at 100°C. In addition, in highlands where the atmospheric pressure is low, it boils at temperatures below 100°C, and the temperature does not rise to 100°C, causing boiling over and burning. The same problem occurs even in a configuration in which the temperature sensor is inserted directly into the food to be cooked.

Means for Solving the Problems In order to solve the above problems, the present invention provides means for detecting the temperature of the food being heated by the heating means, and a heating control for controlling the amount of heating in accordance with this signal. The means is provided with a temperature control section that outputs a control signal, and the temperature control section includes a slope detection section that detects the slope of the temperature rise of the food to be cooked, and a temperature slope that is below a predetermined value when the food boils. A bending point detection unit is provided to detect the bending point where the bending point becomes, and the amount of heating is controlled by the boiling detection signal from the bending point detection unit.

The configuration includes a tilt detection start section that starts tilt detection when the temperature is equal to or higher than a predetermined temperature.

Function With the above configuration, it is possible to directly detect changes in atmospheric pressure, sensor variations, or the temperature of the food when cooking food with a large amount of water, such as by simmering or boiling water. Even in the case where the food is not boiled, it has the function of accurately detecting that the food has boiled, and at the same time has the function of preventing malfunctions caused by detecting an unstable temperature slope at the initial stage of heating by the slope detection start section. .

Example The present invention will be explained below with reference to the drawings.

FIG. 1 is a diagram showing an example of a control system to which the present invention is applied. This example shows an application to a gas staple stove.

1 is a gas inlet, and the gas passes through a proportional control valve 2 and is burned in a burner 3. The burner 3 heats the bottom of the pot 4 and the contents of the cooking material 5.
adding heat to. 6 is a temperature sensor that detects the bottom surface temperature of the pot 4, and this signal is transmitted to the temperature control section 7'. The temperature control section 7 includes an inclination detection section 8, a bending point detection section 9, and a proportional control section 10, and controls the combustion amount of the burner 3 by driving the proportional control valve 2.

In the present invention, when water boils at 1 atm, it boils at 100°C,
Focusing on the fact that the temperature does not rise any further, the configuration is such that the slope of the temperature rise is detected.

FIG. 2 shows temperature rise characteristics, with the horizontal axis X representing time and the vertical axis T representing temperature. The figure shows an example of the characteristics when boiling water, where A shows the temperature of the contents, that is, the water temperature, and B shows the temperature detected by the temperature sensor 6 at the bottom of the pot. Wetting rra is curve A by heating at room temperature.
, B rise, and at temperature Tb, the rising curve becomes gentle once and starts rising again. This is because the moisture condensed around the container evaporates at temperature Tb, and this temperature varies depending on the material and size of the container (pan), but is approximately 4.
The temperature is 0 to 70°C.

As the temperature further increases, the temperature Tc reaches 100°C, and at one atmospheric pressure, the water temperature A boils and does not rise above 100°C. The temperature B of the sensor at this time is Td, and since the water temperature A reaches 100° C., the rising characteristic of Td becomes very small or disappears. The temperature difference between Tc (100° C.) and Td varies greatly depending on the material of the pot and the amount and type of food to be cooked.

Furthermore, if the pressure changes using a pressure cooker or the like, the temperature Tc itself will no longer be 100°C. However, the inflection point C where the slope of temperature rise changes is always the point where water boils.

FIG. 3 is a diagram showing an example of tilt detection or bending point detection. This method is based on the temperature change Δ for each sampling time Δχ.
As T is measured, the bending point detection unit 9 determines that the point where ΔT becomes less than a certain value is the bending point, and detects the temperature Td at that point.
In this method, the temperature of the contents is set to 100°C.

In addition to this method, the bending point detection section may also detect when the ratio of temperature rise falls below a certain value. In other words, (Tn-
The point at which Tn 1)/(Tn-1-Tn-2) is below a certain value is defined as Td. (This formula can be in any form as long as it determines the slope ratio.) The proportional control section 10 uses the signal from the bending point detection section 9 to
゛It is possible to shift to various types of control. An example of this is a method in which the proportional valve 2 is closed in response to a signal from the bending point detector 9 to stop combustion. This is ideal for boiling water. Another example is a method in which the signal from the bending point detection section 9 is used to reduce the amount of combustion and melting, and further heat the product with a small amount of calories. Generally, stews are cooked using the latter method, and are often simmered over low heat for a long time.

FIG. 4 shows this control characteristic, where the horizontal axis X is time, the vertical axis T of characteristic V is temperature, the broken line A is the temperature of the contents as in FIG. 2, and the solid line B is the temperature characteristic of the sensor at the bottom of the pot. The vertical axis I of the characteristic W indicates the control current of the proportional valve, which is proportional to the combustion amount of the burner 3. Until time Xd, the proportional valve current I is at its maximum before the signal from the bending point detection unit 9 shown in FIG.
The amount of combustion is also the maximum combustion. At time Xd, the internal temperature is Tc
When boiling starts at (100° C.), the bending point detection unit 9 detects this and sets the proportional valve current I to the minimum value, narrowing down the combustion amount to the minimum combustion amount. At this time, the proportional control section 10 controls the temperature Td
is set as the set temperature, and the proportional valve current, that is, the combustion amount, is proportionally controlled according to the difference between the set temperature and the sensor temperature. Now, when food is added at time Xe, the internal temperature A decreases. Along with this, the temperature B of the sensor also decreases, and a decrease to the internal temperature is detected. The proportional control unit 10 maintains this temperature T.

The proportional valve current ■ is increased to Ie according to the difference between the temperature Td and the set temperature Td. As a result, the amount of combustion and melting increases, the temperature A returns to the original temperature Tc, and the amount of combustion also returns to the minimum combustion amount. The magnitude of Ie above changes depending on the magnitude of T d −T e, and Td−
When To is large, Ie is large, and when Td-Te is small, Ie is small.

The proportional control valve 2 may be an on-off valve or a multistage valve. At this time, the proportional control section 10 is configured to perform on/off control or multi-stage control operation.

Furthermore, as explained in FIG. 2, in order to prevent the bending point detecting section 9 from detecting the bending caused by the temperature Tb, the bending point detecting section 9 is configured to operate from the measurement start temperature Tf or higher by the tilt detection starting section I, and is unstable. Eliminates errors in detecting bending points due to inclination detection.

Recently, microcomputers (hereinafter referred to as microcomputers) are often used to create complex control systems such as those described above. FIG. 6 shows a simple flow diagram when the control system described in FIGS. 1 to 4 is created using a microcomputer.

In the figure, IG is the subroutine of the ignition sequence of burner 3,
S is a subroutine that reads the temperature S1 of the sensor 6, S2
shows a subroutine for determining the throttle amount of the proportional valve 2 and outputting the current I according to the magnitude of the temperature difference Td-9. ■ indicates the tilt detection start part, and the temperature S1 of the sensor after ignition is Tf
If the value is also low, go through the loop I in the figure and S,>T.
Wait until f.

31>Tf, the inclination explained in FIG. 3 is detected in the part (■). ■ is the bending point detection part, and 'rp in the figure is the above-mentioned (Tn-Tn -1)/(Tn-1-Tn -2)
= T p, and if Tp compared with the constant value P is not smaller than P, the sampling time ΔX is measured to form a loop (■).

'rp-p' and after detecting the bending point, the process shifts to the loop shown in the figure (■) and becomes proportional control. X END indicates a program that stops operating when a preset cooking time X ends.

The effect of the above embodiment is that by configuring a proportional control section that proportionally controls the proportional valve using the temperature of the sensor at the bending point as the set humidity, once it boils, the temperature is maintained and the heat is automatically turned off to low. It is possible to perform simmering instead, and if the temperature drops due to additional ingredients, the amount of combustion will be automatically increased and the original temperature will be restored in a short time. Therefore, you can safely simmer and cook without any failures such as burning or boiling over, and you can save energy by preventing unnecessary heating.

Although the embodiment of the present invention has been described using a gas stove, similar effects can be obtained with a heater for an electric stove or the like. Furthermore, it can be widely applied to cooking appliances such as kettles and rice cookers.

As described in detail, the cooking humidity control device of the present invention has the following effects.

(1) Measuring the slope of temperature rise of cooked food during simmering cooking,
By detecting the bending point, it is configured to detect when the temperature of the food to be cooked has reached the boiling point. Therefore, when the relationship between the humidity of the food and the temperature of the sensor is not constant, the temperature of the sensor may vary. By detecting the temperature at the bottom of the pot, as shown in the example, it is possible to accurately detect the boiling point even when the thickness or material of the pot changes. Even if it's boiling, it won't be detected forever, so you don't have to worry about it boiling over or burning, and it's very easy to use and won't cause cooking failures.

(2) Since the tilt detection starting section I does not perform tilt detection in a portion where the tilt is unstable due to dew condensation or the like in the early stage of heating, errors in tilt detection are small and malfunctions can be prevented.

[Brief explanation of drawings]

Fig. 1 is a control system diagram showing one embodiment of the cooking temperature control device of the present invention, Fig. 2 is a characteristic diagram showing the rising state of the sensor section and internal temperature of Fig. 1, and Fig. 3 is an inclination Fig. 4 is a characteristic diagram explaining the state of detection of a bending point in the detection unit, Fig. 4 is a characteristic diagram explaining the operation of the proportional control unit after detecting a bending point, and Fig. 5 is a conventional example of a proportional control system using 14 HEPA for pan bottom temperature detection. The control system diagram, FIG. 6, is a schematic flow diagram showing an example of a case where the temperature control section (section 7 in FIG. 1) of the present invention is configured by a microcomputer. 2... Proportional control valve (heating control means), 3...
・Burner (heating means), 4...Pot (container), 5
... Cooking food, 6 ... Sensor (temperature detection means), 7 ... Temperature control section, 8 ... Inclination detection section, 9 ...・Bending point detection part, 10...
・Proportional control section, ■...Inclination detection start section, Td
......Set temperature, Tf...Measurement start temperature, P...Predetermined value. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 0↓ B T ---m-- Tc A 7T-1111-cho Figure 3 × Ko × Figure 4

Claims (1)

[Claims] A control signal is sent to a heating means for heating a food containing moisture, a temperature detection means for detecting the temperature of the food, and a heating control means for controlling a heating amount of the heating means in accordance with a signal from the temperature detection means. The temperature control section includes a slope detection section that detects a temperature rise slope of the food to be cooked by the temperature detection means, and a temperature slope detected by the slope detection section when the food boils. has a bending point detecting section that detects a bending point where the bending point becomes less than a predetermined value, and the heating amount of the heating means is varied or stopped according to a boiling detection signal from the bending point detecting section, and the tilt detecting section This is a cooking temperature control device that operates based on a signal from a tilt detection start section that detects that the temperature detected by the temperature detection means has exceeded a predetermined measurement start temperature.