JPS6116714A - Temperature control pressure kettle - 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 The present invention uses a heating cooker such as a pressure cooker to reduce the temperature of the food to boiling when cooking with a high amount of water such as simmering or stewing in a short period of time. The present invention relates to a temperature-controlled pressure cooker that accurately detects when the temperature is near and controls the amount of heating appropriately.

Structure of conventional hook and its problems In FIG. 1, 1 is a gas inlet, and gas passes through a cock 2' and is burned in a burner 3. 4 is a trivet on which a cooking container is placed, and 5 is a gas stove consisting of these. 6 is a pressure cooker, which is heated by a burner 3. 7 is a food to be cooked in the pressure cooker 6. Reference numeral 16 designates the lid of the pressure cooker 6, which is provided with a fastener 17 at the center of the lid and a gasket 18 made of a heat-resistant material around the lid, which seals the lid with the pressure cooker 6 during use. Reference numeral 19 denotes a pressure regulator, which is fixed to the lid 16 and has one end directed into the pressure cooker 6 and the other end exposed to the atmosphere, and releases steam from a small hole (not shown) during heating to adjust the pressure inside the pressure cooker 6. It keeps the pressure constant. 20
is a safety valve, which is similarly fixed to the lid 16, with one end directed into the pressure cooker 6 and the other end exposed to the atmosphere, and which releases steam when the pressure inside the pressure cooker 6 exceeds the allowable pressure. It lowers the pressure inside the pressure cooker 6. 21 is a lid support;
The lid 16 can be brought into close contact with the pressure cooker 6 by installing both ends onto the upper end 6 of the pressure cooker 6 and tightening the fasteners 17.

Conventionally, when the pressure cooker 6 is used to stew stew, curry, etc., or boil potatoes, the pressure inside the pot increases, so the boiling point of water becomes high and cooking can be done in a relatively short time. However, in order to adjust the pressure inside the pressure cooker 6, steam must always be released from the pressure regulator 19 to the outside of the pot during heating and boiling, which is wasteful due to the amount of heat carried away by the steam and the fuel cost for continuous heating. This has the disadvantage that it consumes a lot of energy and releases a large amount of steam into the room, causing indoor pollution.

Therefore, an automatic control device that detects the temperature of the contents and automatically adjusts the firepower when the contents boil is considered.

However, inserting a temperature sensor into a cooking pot to detect the temperature of the contents is inconvenient, difficult to seal the pot, and feels unclean. For this reason, a method has been devised in which a temperature sensor is brought into contact with the bottom of a cooking pot to detect the bottom temperature of the pot and to infer the temperature of the contents. However, this method had the disadvantage that the temperature at the bottom of the pot and the temperature of the contents were not constant and varied depending on the material and shape of the pot, the type and amount of contents, etc. Therefore, it is difficult to accurately detect when the temperature of the contents reaches the boiling point and then adjust the temperature to a constant temperature within a small range.

Purpose of the Invention The present invention is a cooking temperature control device that detects the temperature at the bottom of a pressure cooker, which can be set regardless of the type and amount of contents, especially when the internal temperature is controlled to a boiling state when cooking with a lot of water such as boiling or stewing. Moreover, by controlling the amount of heating, the purpose is to prevent the release of excess steam, save energy, and maintain the safety of the appliance by keeping the pressure inside the pot constant.

Composition of the Invention The temperature-controlled pressure cooker of the present invention is configured to use a temperature control device to detect the slope of the temperature rise of the contents being simmered, and to detect the boiling point according to the slope value. The temperature at that time is set as the set temperature, and the temperature is adjusted within a small range with respect to the set temperature by varying the amount of heating.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram of the temperature-controlled pressure cooker of the present invention, and FIG. 3 is a diagram showing an example of a control system applied to the present invention.

Note that the same numbers as in the conventional example shown in FIG. 1 have the same names, and a description of the structure will be omitted.

The dregs pass from the dregs population 1 through an on-off valve 2 and are burned in a burner 3. The burner 3 heats the bottom of the pressure cooker 6 and adds heat to the cooked food 7. 8 is a temperature sensor that detects the bottom surface temperature of the pressure cooker 6, and this signal is input to the temperature detection section 9;
The temperature is transmitted to the temperature control section 10. The temperature control section 10 includes an inclination detection section 11, a bending point detection section 12, and a heat amount control section 13, and controls the combustion amount of the burner 3 by driving the on-off valve 2.

Now, in the present invention, once the pressure inside the pressure cooker is determined, water will boil at a certain temperature and will not rise any further. (For example, at a gauge pressure of 1 kg/cyA, it boils at about 119°C.) Similarly, we focused on the fact that the temperature rise at the bottom of the pressure cooker would also be reduced, and we designed a structure that detects the bending point of the slope of the bottom temperature.

Figure 4 shows the 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 a pressure cooker 6 is used to boil the area, where A is the temperature of the contents, that is, water temperature, and B indicates the temperature at the bottom of the pot, that is, the temperature detected by the temperature sensor 8.

The temperature Ta is at a moderate temperature and increases in both curves A and B due to heating. The temperature B detected by the temperature sensor 8 has a gradual rising curve once at the temperature Tb, and then begins to rise again from the temperature Tf. This is because dew condenses on the bottom of the pan at temperatures around Tb to Tf and evaporates. Temperatures Tb to Tf are approximately 40 to 70'C, although this varies depending on the size and material of the pan 4. Furthermore, the temperature continues to rise until the temperature Tc reaches approximately 119°C, and the water temperature A boils and does not rise above 119°C. The sensor temperature B at this time is Td. Td and water temperature A are 119
From the point at which the temperature rises to °C, the rate of rise becomes very small or disappears. The temperature difference between this Tc point 119℃ and Td is the temperature difference between the pot 6
It varies greatly depending on the type of food (material and thickness), amount and type of food being cooked. However, the inflection point C where the slope of temperature rise changes
is always after the water temperature A has boiled.

Furthermore, in order to prevent the bending point detection unit 12 from detecting the bending caused by the temperature Tb-Tf, the bending point detection unit 12 is configured to operate from the measurement start temperature Tf or higher (a temperature at which the temperature rise is stable). Eliminates bending point detection errors.

Here, the temperature increase slope Tx at a constant time interval ΔXA is measured at a point Tf exceeding point Tb in FIG. 4, and the bending value Tu is calculated using this slope Tw as a function.

This bending value Tu is compared with ΔT in the bending point detection unit 12, and Δ
The bending point C is determined at the point where T is smaller than Tu.

The heat amount control section 13 controls the combustion amount from 1 ON to OFF based on the signal from the bending point detection section 12, or controls the amount of combustion to be further heated with a small amount of calories, which is generally suitable for simmering and takes a long time over low heat. It can be boiled.

FIG. 5 is a diagram showing an example of detection of a bending point of sensor temperature B. In this method, the temperature Tn-
The temperature change ΔT is sequentially measured from m-Tn, and the bending point detection unit 12 determines that the point where ΔT becomes equal to or less than the bending value Tu is the bending point, and the content temperature is determined at the temperature Td at that time. This is a method of setting the temperature to 119°C.

Figure 6 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 Figure 4, and the solid line B is the sensor temperature characteristic at the bottom of the pot. . The vertical axis I of the characteristic W indicates rONJ [○FFJ] of the on-off valve 2, which is interlocked with "ON"[OFF'J] of the burner 3. Until time Xd, the on-off valve 2 is in the "ON" state and the burner 3 continues combustion before the signal from the bending point detection section 12 shown in FIG. 5 is output. When the internal temperature reaches the Tc point of 119° C. at time Xd and boiling begins, the bending point detection unit 12 detects this and turns the on-off valve 2 “OFF” to stop combustion. At this time, the temperature Td is set as the set temperature in the heat quantity control section 13.

For example, if the value of the set temperature Td is 130°C, the on-off valve 2 can actually be operated at 130°C and 127°C. In other words, turn off the on-off valve 2 at Td=13o'c.
JL, stop combustion. At Tdi -127°C, the on-off valve 2 is turned “QN” and combustion is started. As the sensor temperature B changes in this way, the temperature of the contents also follows. In other words, there is a slight temperature change between Tc and Tc1, but there is no problem during actual use, and compared to other pots, cooking can be done in a shorter time.

When the temperature of contents A is Tc, steam is released from the pressure regulator 19, and when it is Tc1, the amount of steam released is smaller, resulting in less wasteful use of thermal energy compared to conventional pressure cookers. At the same time, since the amount of steam released is reduced, indoor contamination due to steam can be prevented.

Moreover, if the food to be cooked is added at time Xe, the content temperature A decreases. Along with this, the sensor temperature B also decreases and the content temperature A
detect a decrease in The calorie control unit 13 detects this temperature Te, turns on the on-off valve 2, and automatically restarts combustion. Although the combustion control by turning the on-off valve 2 ON and OFF has been explained above, the purpose can also be achieved by controlling the combustion amount using a proportional valve.

Effects of the Invention As described above, the temperature-controlled pressure cooker of the present invention measures the slope of temperature rise of the food during simmering, changes the bending value according to the slope, and detects the bending point. Since the structure detects when the temperature of the food to be cooked has reached the boiling point, the boiling point can be accurately detected even if the relationship between the temperature of the food and the sensor temperature is not constant.

In addition, the method for detecting inclinations and bending points is to obtain the difference in sensor temperature by sampling at fixed time intervals, which makes it easy to control with a microcomputer, etc., and allows accurate bending point detection just by processing a program. This makes it easy to configure the system.

Furthermore, the tilt detection starts from the point where the sensor temperature reaches a predetermined temperature or higher, so that even if there is tilt fluctuation due to water condensing on the bottom of the pot during the initial heating stage, it is ignored, ensuring a stable and reliable tilt detection. can be detected and therefore
The bending point (boiling point) can be detected.

In addition, by having a heat amount control unit that controls the on-off valve using the sensor temperature at the bending point as the set temperature, once it has boiled, it is possible to automatically change the heat amount and simmer while maintaining the temperature, and further add ingredients etc. If the temperature drops, the amount of combustion is automatically increased and the original temperature is restored in a short time. Therefore, stewing can be done safely in a short time without any failures such as burning or boiling over, and it also prevents unnecessary heating and saves energy. In other words, since the amount of steam released from the pressure cooker is reduced, thermal energy can be saved, and accidents such as indoor contamination due to steam and burns can be prevented.

Furthermore, if the bottom of the pot is in contact with the temperature sensor, boiling can be detected regardless of the amount of food being cooked or the shape of the pot.

[Brief explanation of drawings]

Figure 1 is a schematic partial cross-sectional view of a conventional example using a pressure cooker;
The figure is a schematic partial sectional view showing one embodiment of the temperature-controlled pressure cooker of the present invention, FIG. 3 is a control system diagram of the same, FIG. FIG. 5 is a characteristic diagram illustrating the bending point detection state, and FIG. 6 is a characteristic diagram illustrating the operation of the heat quantity control section after the bending point is detected. 3...Burner (heating means), 2...Opening/closing valve (heating control means), 6...Pressure cooker (cooking container), 7...Cooking material , 8... Temperature sensor, 9... Temperature detection section, 10... Temperature control section, 11... Tilt detection section, 12......・
Bending point detection unit, 13... Heat amount control unit, 16...
... Lid, 19 ... Pressure adjustment device, 2o.
... Safety valve, Tw ... Incline, Tu ...
...Bending value, C...Bending point, ΔT...
·Temperature rise. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure/3. S Figure 2 I'1 Figure 3 Figure 4 □ X Figure 5 Figure 6

Claims (1)

[Claims] A heating means for heating the food to be cooked, a heating control means for controlling the heating amount of the heating means, a cooking container installed above the heating means, and a pressure regulating device and a safety valve provided on the lid of the cooking container. , a temperature sensor is installed on the bottom surface of the cooking container; a temperature detection section that detects the temperature of the food to be cooked using the temperature sensor; and a temperature detection section that outputs a control signal to the heating control means in accordance with a signal from the temperature detection section. The temperature control unit includes a slope detection unit that detects a temperature rise slope of the food to be cooked by the temperature detection unit, and a bending point where the temperature rise is smaller than a bending value calculated as a function of the temperature slope. A temperature-controlled pressure cooker comprising: a bending point detecting section; and a heat amount control section varying the amount of heating based on a signal from the bending point detecting section.