JPS6331204B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a control device for an electric boiler such as an electric rice cooker that can cook rice porridge and the like.

(b) Prior Art Conventionally, in an electric rice cooker, a heat-sensitive element is provided at the bottom of the inner pot, and the heater is controlled based on the output of this heat-sensitive element. With such electric rice cookers, good results can be obtained in detecting the completion of rice cooking and in detecting temperatures in low temperature ranges, but if the heater for rice cooking is nearby, it may be greatly affected by the heat or be exposed to heat. Since this method is greatly influenced by the non-uniformity of the temperature distribution of the food to be cooked, it has not been possible to obtain very favorable results in detecting the boiling of the food to be cooked. Therefore, in order to cook rice porridge etc. in an ideal manner,
Since accurate boiling detection of the food to be cooked is required, with the above configuration, it is not possible to cook rice porridge or the like in good condition.

(c) Problems to be Solved by the Invention The present invention takes the above-mentioned drawbacks into account and allows cooking of rice porridge and the like in good condition.

(d) Means for Solving the Problems The control device for an electric boiler of the present invention comprises an outer pot and a bottomed cylindrical container for storing food that is removably inserted into the outer pot. A cooking device comprising an inner pot and a boiling heater that heats the inner pot, and detecting boiling of the food to adjust the calorific value of the boiling heater,
A heat sensitive body is provided inside the lid, and boiling is detected by this heat sensitive body.

(E) Effect Since the present invention is constructed as described above,
The heat sensitive element outputs a signal in response to a sudden increase in the amount of steam during boiling, without being influenced by external factors.

(f) Examples Examples of the present invention will be described based on the drawings. FIG. 1 shows a schematic cross-sectional view. 1 is a cylindrical frame, 2 is a bottomed cylindrical outer pot inside the frame,
Reference numeral 3 denotes an inner pot which is detachably inserted into the outer pot and stores the food to be cooked; 4 is a ring-shaped boiling heater provided at the inner bottom of the outer pot 2; and 5 is a center bottom of the outer pot 2. The first part is always energized by a spring 6 so as to be in close contact with the outer bottom surface of the inner pot 3 (the position where the temperature of the food to be cooked is most accurately sensed until the food reaches boiling temperature). It is a negative thermistor whose resistance value decreases as the temperature rises, and its Curie point is set at around 70 degrees. Reference numeral 7 denotes a rotatable lid body for closing the outer pot 2 and the inner pot 3, which includes an outer lid 8, an inner lid 9 with good heat conduction, a lid packing 10 held between the outer periphery of each lid, and an inner lid. The second heat sensitive body 11 is provided in close contact with the upper surface of 9 (the position where the boiling temperature is accurately detected). A Currie point has been set up nearby. 12 is an auxiliary lid provided on the lower surface of the lid 7, and 13 is the frame 1 and the outer pot 2.
A frame cover 14, which fits and fixes the edge of the upper opening, is a back cover fixed to the lower part of the frame 1, and forms a storage chamber 16 for an electronic circuit 15, which will be described later.

Figure 2 shows an electronic circuit, where MC is a microcomputer that has input gates I ₁ and I ₂ and output gate Oo and is programmed with predetermined functions, and RY is a built-in contact RYS for the boiling operation. Relay connected in series to heater 4, E is DC power supply,
STW is a start switch connected in series to the power supply,
BG ₁ is a first bridge circuit that includes the first heat sensitive body 5, one side connects the first heat sensitive body 5 and a resistor _R1 in series, and the other side connects a resistor _R2 and a resistor _R3 in series to provide a reference voltage. Set each connection to the first comparator
The output of the _comparator is connected to one input gate _I1 of the microcomputer MC. BG ₂ is a second bridge circuit that includes the second heat sensitive body 11, one side connects the second heat sensitive body 11 and a resistor _R4 in series, and the other side connects a resistor _R5 and a resistor _R6 in series to provide a reference voltage. and each connection is connected to the input gate of a second comparator CP ₂ , the output of which is connected to another input gate I ₂ of the microcomputer MC. R ₇ and R ₈ are feedback resistors connected to the output gates of the respective comparators, and Tr is connected in series with the relay RY and turned on and off by the output gate Oo of the microcomputer MC via the resistor R ₉ . He is a driver.

Next, we will discuss the operation. First, when cooking rice normally, a predetermined amount of water and rice are stored in the inner pot 3, inserted into the outer pot 2, and the input level is connected to another input gate (not shown) of the microcomputer MC. Operate the selector switch (not shown) to set it to the "cooking" position, then press the start switch.
The STW is turned on to set the temperature detection state of only the first heat sensitive element 5 and perform the rice cooking operation.

To cook porridge, store rice and a large amount of water in the inner pot 3, insert the inner pot into the outer pot 2, operate the changeover switch to set it to the "porridge" position, and press the start switch STW. Turn on. With this ON operation, the microcomputer MC
The output signal of the output gate Oo turns on the driver Tr through the resistor _R9 , drives the relay RY, and connects the contact.
Power is applied to the boiling heater 4 via RYS. This is because the output of the first comparator CP ₁ becomes "H" due to the large resistance value of the first heat sensitive element 5, and in response, the output gate of the microcomputer MC becomes "H".

As shown in Fig. 3, the temperature of the rice porridge rises rapidly as the amount of heat from the boiling heater 4 directly heats the inner pot 3, and when it reaches around 90 degrees, the temperature of the first heat-sensitive element 5 rises to about 70 degrees. When the output of the first comparator CP ₁ changes from "H" to "L", the microcomputer
The first program in the MC turns the relay RY "ON" and "OFF" at predetermined intervals to slightly reduce the calorific value of the boiling heater 4 and gradually reach the boiling temperature. When the temperature of the porridge reaches boiling temperature,
The amount of steam generated in the inner pot 3 increases rapidly, and this steam heats the auxiliary lid 12 and the inner lid 9, causing the inner lid to rise to about 80 ml.
reach the degree. The second heat sensitive body 11 that sensed this temperature
As the resistance value increases rapidly, the output of the second comparator _CP2 changes from "L" to "H" and is input to the input gate _I2 of the microcomputer MC. (for about 20 minutes), the driver Tr is controlled by the second program to further reduce the calorific value of the boiling heater 4 by turning it "ON" and "OFF".
Control. Eventually, after a predetermined period of time has elapsed, the output duty of the microcomputer MC is greatly changed to minimize the energization rate of the boiling heater 4 and shift to the heat retention state. After this predetermined time has elapsed, the heating of the boiling heater 4 may be completely stopped if it is not necessary.

(g) Effects of the Invention As described above, the present invention provides an outer pot, a bottomed cylindrical inner pot for storing food that is removably inserted into the outer pot, and the outer pot and the inner pot. and a boiling heater that heats the inner pot, and detects boiling of the food to adjust the calorific value of the boiling heater, wherein the lid has a heat-sensitive Set up your body,
Since boiling is detected using this heat-sensitive body, boiling can be detected accurately and in good condition even when cooking porridge or the like where boiling detection is important.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the electric rice boiler of the present invention, FIG. 2 is an electric circuit diagram, and FIG. 3 is a characteristic diagram of the food to be cooked. DESCRIPTION OF SYMBOLS 1... Frame, 2... Outer pot, 3... Inner pot, 4... Boiling heater, 5... First heat sensitive body, 7... Lid body, 11... Second heat sensitive body (heat sensitive body).

Claims (1)

[Claims] 1. An outer pot, a cylindrical inner pot with a bottom for storing food that can be inserted into and removed from the outer pot, a lid for covering the outer pot and the inner pot, and the inner pot. A boiling heater that heats the food and detects boiling of the food to adjust the amount of heat generated by the boiling heater, wherein a heat sensitive body is provided in the lid, and the heat sensitive body detects boiling. A control device for an electric boiler characterized by: