JPH0221822A - Electrical cooker - Google Patents

Abstract

PURPOSE:To prevent a steaming overflow and enable cooking rice gruel and the like of good taste by reducing the calorific value of a heater in such a way that a control means is regulated with a boiling detection means and a timer means for maintaining the temperature of a cooked object near a boiling temperature for the predetermined time after the boiling thereof. CONSTITUTION:When rice gruel is cooked, a selector switch is set to a 'gruel' position and a start switch STW is turned on, thereby supplying electric power to a cooking heater 4. The calorific value of the cooking heater 4 is used to directly heat an inner pan 3. The temperature of the gruel, therefore, suddenly rises and when the temperature reaches the neighborhood of 90 degrees, the temperature of the first thermosensible body 5 reaches about 70 degrees, thereby reducing slightly the calorific value of the cooking heater 4 and causing the value to gradually reach the boiling temperature. When the temperature of the gruel reaches the boiling temperature, the generated steam amount of the inner pan 3 suddenly increases and the temperature of an inner lid 9 reaches about 80 degrees. The second thermosensible body 11 upon detecting the temperature suddenly drops in resistance value and, therefore, a microcomputer MC actuates a driver Tr for maintaining the neighborhood of the boiling temperature for the predetermined time of about 20 minutes via a timer, thereby making the 'ON' and 'OFF' control of the cooking heater 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electric cooker capable of cooking rice porridge and the like.

(B) Conventional technology Conventionally, in electric rice cookers, a heat sensitive body is provided at the bottom of the inner pot, and the heater is controlled based on the output of this heat sensitive body (for example, Japanese Patent Laid-Open No. 55 138420 Official Residence). 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. The boiling of the food to be cooked cannot be accurately detected because it is greatly affected by the unevenness of the temperature distribution of the food to be cooked. Therefore, when cooking rice porridge or the like, if boiling cannot be detected accurately, a large amount of boiling water will overflow, making it impossible to continue cooking.

In addition, with conventional rice cookers, cooking will not end until the moisture in the food is gone and the temperature of the inner pot rises to 100°C or above -E. However, you had to manually turn off the rice cooking switch to finish cooking, which made it inconvenient to use.

(c) Problems to be Solved by the Invention The present invention has been made in consideration of the above points, and is intended to provide an electric cooker that can cook rice porridge etc. well.

(d) Means for Solving the Problems The present invention provides an outer pot, an inner pot provided in the outer pot for storing food to be cooked, a lid body for covering the outer pot and the inner pot, and a lid body for covering the outer pot and the inner pot. A heater for heating the inner pot, a boiling detection means for detecting boiling of the food by means of a heat sensitive element provided on the lid, a heating control means for varying the amount of heat generated by the heater, and a timer means, The control means is configured to reduce the amount of heat generated by the heater under the control of the boiling detection means and the timer means so that after the food has boiled, the temperature of the food to be cooked is maintained near the boiling temperature for a predetermined period of time. be.

(E) Function Since the present invention is constructed as described above, the heat-sensitive element provided on the straight rod reacts to a sudden increase in the amount of steam during boiling,
The boiling detection means accurately detects boiling of the food to be cooked. After boiling, the amount of heat generated by the heater decreases to prevent the food from overflowing. Furthermore, by maintaining the temperature near the boiling temperature for a predetermined period of time, gelatinization of the rice is sufficiently promoted, and rice porridge and the like can be deliciously cooked.

(F) Embodiment 4 An embodiment of the invention will be described based on the drawings. FIG. 1 shows a schematic cross-sectional view. (1) is a circular frame, (2)
(3) is a bottomed cylindrical outer pot built into the frame; (3) is an inner pot that can be inserted into and removed from the outer pot and stores 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 ring-shaped boiling heater provided at the center of the bottom of the outer pot (2) by a spring (6). ) outer bottom surface (
The first heat sensitive element is energized to be in close contact with the position that most accurately senses the temperature of the food being cooked until it reaches boiling temperature, and is a negative thermistor whose resistance value decreases as the temperature rises. The Curie point is set at around 70 degrees. (7) is a rotatable lid that covers the outer pot (2) and the inner pot (3), and the outer pot (2), the inner pot (9) with good heat conduction, and the outer periphery of each lid. Lid backing sandwiched between (
10) and a second heat sensitive element (11) provided in close contact with the upper surface of the inner lid (9) (the position where the boiling temperature is accurately detected). It is a thermistor with a Curie point set around 80 degrees.

(12) is an auxiliary lid provided on the lower surface of the lid body (7), and (13) is the frame (1) and outer pot (2).
A frame cover that fits and secures the edge of the upper opening of (
14) is a back cover fixed to the lower part of the frame (1);
It forms a storage chamber (16) for an electronic circuit (15) to be described later.

Figure 2 shows an electronic circuit, in which (MC) has input gates (L), (II) and output gates (Oo), and is a microcomputer used to program predetermined functions including a timer function. (RY) is a built-in contact (
RYS) connected to the boiling heater (4) in a row, (E) is a DC power supply, t' S T W )
is the start switch connected in series to the power supply, (BG,)
is a first bridge circuit including the first heat sensitive body (5), -
The first heat sensitive element (5) and resistor (R1) are connected in series on one side, and the resistor (R1) and resistor (R8) are connected in series on the other side to set the reference voltage, and each connection is connected to the first comparator. (CP,
) and the output of the comparator is connected to one input gate (11) of the microcomputer (Ni C). (BG line is the second bridge circuit including the second heat sensitive body (11), the negative side is the series connection of the second heat sensitive body (11) and the resistor (R4), and the other side is the resistor (R3).
) and a resistor (R6) are connected in series to set a reference voltage, and each connection is connected to the input gate of the second converter (CP□), and the output of this comparator is connected to the other of the microcomputer (MC). It is connected to one input gate (1,). (R,) (R1) is a feedback resistor connected to the output gate of each comparator, (Tr) is connected in series to the relay (RY>), and is connected to the output gate (0, MC) of the microcomputer (MC). ) by resistance (R
9) is a driver that turns ON and OFF. Next, we will discuss the operation. First, when cooking rice in a suitable manner, the specified amount of water and rice are stored in the inner pot (3) and inserted into the outer pot (2), and other input gates (not shown) of the microcomputer (MC) are inserted. ) connected to the input level selector switch (not shown), set it to the "cooking" position, turn on the start switch (S T W ), and set the temperature detection state of only the first heat sensitive element (5) to start the rice cooking operation. Do the following.

To cook rice porridge, store rice and a large amount of water in the inner pot (3), insert the inner pot into the outer pot (2), and operate the switch to set it to the "porridge" position. Then turn on the start switch (STW). Along with this ON operation, the output gate (0
The output signal of ゜) is sent to the driver (T
Turn on r) to drive the relay <RY) and turn the contact (RYS
) is applied to the boiling heater (4). This is because the resistance value of the first heat sensitive element (5) is large, so the output of the first comparator (CP) becomes "11", and in response, the output gate of the microcomputer (MC) becomes "H". It is.

As shown in Figure 3, the temperature of the porridge rises rapidly due to the amount of heat from the boiling heater (4) directly heating the inner pot (3).
When the temperature reaches around 0 degrees, the temperature of the first heat sensitive body (5) is about 70 degrees.
The output of the first comparator (CP, ) reaches r
I (J becomes "L" and microcomputer (MC)
According to the first program, the relay (RY) is turned 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), so that the inner lid reaches about 80 degrees. reach. The resistance value of the second heat sensitive body (11) that senses this temperature increases rapidly, so the output of the second comparator (CP) changes from "L" to "H" and the microcomputer (M
The input gate (I) and the output gate (0°) of C) are controlled by a driver by a second program so that the porridge stays near the boiling temperature for a predetermined period of time (approximately 20 minutes) using a microcomputer (MC) timer. (Tr) to further reduce the calorific value of the boiling heater (4).The rice gelatinization condition is to maintain the rice temperature at 98°C or higher for about 20 minutes during this period. is satisfied, and the gelatinization of the rice is sufficiently promoted. Eventually, after a predetermined period of time has elapsed, the duty of the output of the microcomputer (MC) is greatly changed to minimize the energization rate of the boiling heater (4), and the rice is kept warm. After this predetermined time has elapsed, if it is not necessary, the heat generation of the boiling heater (4) may be completely stopped and the porridge cooking may be completed.

(G) Effects of the Invention As described above, the present invention is capable of detecting the boiling of the food to be cooked in response to a sudden increase in the amount of steam by providing a heat-sensitive element in the lid, so it is not affected by external factors. It is possible to accurately detect boiling without causing boiling, and to maintain the vicinity of the boiling temperature after boiling to reduce the amount of heat generated by the heater, thereby preventing overflow. Furthermore, since the temperature is maintained near the boiling temperature for a predetermined period of time, the gelatinization of the rice is sufficiently promoted, and after a predetermined period of time has elapsed, the heating value of the heater is further reduced to automatically keep the rice warm, so it can be used for cooking with rice gruel, etc. It can be done well.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the electric cooking device of the present invention, FIG. 2 is an electric circuit diagram, and FIG. 3 is a characteristic diagram of the food to be cooked. (1)...Frame, (2)...Outer pot, (3)...
- Inner pot, (4)... Boiling heater, (5)... First heat sensitive body, (7)... Lid body, (11)... Second heat sensitive body, (MC). ...A microcomputer with a timer function. Applicant: Sanyo Electric Co., Ltd. and 1 other person Agent: Patent attorney Takuji Nishikei (2 others) Figure 13 Wotomei-1 Figure 2

Claims (2)

[Claims] (1) an outer pot, a cylindrical inner pot with a bottom for storing food provided in the outer pot, and a lid body for covering the outer pot and the inner pot;
a heater that heats the inner pot; a boil detection means that detects and outputs boiling of the food to be cooked using a heat sensitive element provided on the lid; and a heating control means that varies the amount of heat generated by the heater;
and a timer means that operates based on the output of the boiling detection means, and the heating control means is controlled by the boiling detection means and the timer means, and after the food to be cooked has boiled, the temperature of the food to be cooked is controlled by the timer to be around the boiling temperature. An electric cooking device characterized in that the amount of heat generated by the heater is reduced so as to maintain the temperature for a predetermined period of time. (2) The heating control means further reduces the amount of heat generated by the heater or stops the heat generation after maintaining the temperature of the food to be cooked near boiling temperature for a predetermined period of time. Electric cooker.