JP2004073311A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker wherein the accuracy of a detected temperature is increased, and an accurate rice cooking capacity judgement can be performed based on the detected temperature. <P>SOLUTION: A steam temperature sensor 18 (steam sensor) which detects a steam temperature is provided in a steam discharging path 15 provided in a lid body 4 which discharges steam generated from the inside of a internal pot 2 (cooking pot) to the outside of the lid body 4. A microcomputer 8 (control means) acquires respective required periods of time t<SB>l</SB>and t<SB>2</SB>until the detected temperatures by a temperature sensor 12 for the lid (lid sensor) and the steam temperature sensor 18 reach respective transfer temperatures T<SB>3</SB>and T<SB>4</SB>. The required period of time t<SB>1</SB>or t<SB>2</SB>which has reached the transfer temperature T<SB>3</SB>or T<SB>4</SB>earlier is obtained as a judgement time t<SB>SE</SB>. Then, the rice cooking capacity judgement is performed based on the judgement time t<SB>SE</SB>. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to home and commercial rice cookers. In particular, it relates to rice cooker capacity determination control of a rice cooker.
[0002]
[Prior art]
Generally, as a method of determining the rice cooking capacity of a rice cooker, a lid sensor is brought into contact with an outer surface of an inner lid of a lid to detect a temperature of a heat radiating plate provided on the inner lid. A method of measuring a time required to reach a predetermined temperature (transition temperature) from an initial temperature and determining a rice cooking capacity based on the time is adopted.
[0003]
[Problems to be solved by the invention]
However, in the rice cooker, if the heat radiating plate provided on the inner lid is not properly attached and loose, the detection of boiling is delayed, and there is a risk of spilling over. At this time, if the transition temperature of the lid sensor is reduced in order to prevent spillage, there is a problem that the rice cooking capacity determination time is shortened and the determination accuracy is reduced. In addition, when the dimensions of the heat radiating plate vary, there is another problem that the temperature detected by the lid sensor differs for each product. Furthermore, since the heat sink is generally made of stainless steel, there is a problem that the accuracy of the detected temperature is low.
[0004]
Therefore, an object of the present invention is to provide a rice cooker capable of improving the accuracy of the detected temperature and performing accurate rice cooking capacity determination based on the detected temperature.
[0005]
[Means for Solving the Problems]
The present invention, as means for solving the above problems,
A cooking pan, a main body for housing the cooking pan, heating means for heating the cooking pan, a lid attached to the main body so as to be openable and closable, and an opening of the cooking pan, and provided on the lid. A lid sensor for detecting the temperature of the heat sink, and a rice cooker including control means for controlling the heating means,
A steam sensor that detects a steam temperature is provided in a steam discharge path provided inside the lid that discharges steam generated from inside the cooking pot to the outside of the lid,
The control means obtains each required time until the detection temperatures of the lid sensor and the steam sensor reach each transition temperature, obtains the required time on the side where the transition temperature reached the transition temperature earlier as a determination time, and determines the determination time. Is used to determine the rice cooking capacity.
[0006]
In the above invention, the steam sensor accurately detects the steam temperature irrespective of the set state and the dimensional variation of the heat sink attached to the lid, so that the accuracy of the detected temperature is improved. As a result, the accurate transition temperature can be detected and stable cooking rice capacity determination can be performed.
[0007]
In the rice cooking capacity determination, the rice cooking capacity determination may be performed based on the heating output time required during the required time until the transition temperature is reached, in addition to the determination time. Specifically, in the capacity determination, the capacity determination rank is determined according to the value of the sum of the time required for the mid-span process and the heating output time during that time. Here, the heating output time refers to a time during which an output for heating is actually performed to the heating means of the rice cooker. Thus, by taking into account the heating output time, more accurate rice cooking capacity determination is performed.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0009]
FIG. 1 shows a pressure cooker 1 to which a rice cooker according to the present invention is applied. The pressure cooker 1 includes an inner pot 2 serving as a cooking pot, a main body 3 and a lid 4.
[0010]
The inner pot 2 is formed by coating an outer surface of a pot base material made of aluminum or the like having a high thermal conductivity with a ferromagnetic material that is electromagnetically heated by an eddy current generated when a high-frequency current is supplied to an induction heating coil 6 described later. Or joined together.
[0011]
The main body 3 includes a protective frame 5 made of a non-conductive material for accommodating the inner pan 2 inside a body 3 a having a bottomed cylindrical shape. Between the body 3a and the protective frame 5, an induction heating coil 6 as a heating means, an inner pot temperature sensor 7 and a microcomputer 8 as a control means are arranged.
[0012]
The induction heating coil 6 is disposed on the lower surface of the protection frame 5 and is configured to heat the inner pot 2 by electromagnetic induction when a high-frequency current is applied.
[0013]
The inner pan temperature sensor 7 detects the temperature of the inner pan 2, is disposed at the bottom of the protective frame 5, and has a detecting portion at the tip thereof through a through hole provided in the protective frame 5. And outputs the temperature of the inner pan 2 to the microcomputer 8.
[0014]
The lid 4 closes the inner pan 2 and the opening of the main body 3 so as to be openable. An inner lid 9 is provided on the inner pan 2 side. The inner lid 9 is provided so as to be detachable from the lid body 4, and a radiator plate 10 made of stainless steel and a lid heater 11 are provided inside. Further, inside the lid 4, a lid temperature sensor 12 (lid sensor), a pressure sensor 13, and a pressure regulator 14 are provided.
[0015]
The lid temperature sensor 12 detects the temperature of the heat sink 10 and outputs the detected temperature to the microcomputer 8.
[0016]
The pressure sensor 13 detects the pressure in the inner pan 2 and outputs the detected pressure to the microcomputer 8, and the detection unit is disposed so as to face the inside of the inner pan 2.
[0017]
The pressure regulator 14 includes a steam discharge path 15 having an opening 15 a communicating with the inner pot 2, a pressure regulating ball 16 disposed above the opening 15 a, and a solenoid 17 serving as a driving means of the pressure regulating ball 16. Consists of The pressure regulator 14 presses the pressure regulating ball 16 by a plunger 17a of a solenoid 17 before rice cooking, after rice cooking, and after the completion of rice cooking, and retreats from the opening 15a. Are communicated via the steam discharge path 15. Further, at the time of pressure cooking, while the opening 15a is closed by the weight of the ball to increase the internal pressure of the inner pot 2, pressure is input while the inner pressure of the inner pot 2 exceeds, for example, 0.15 kg / cm ² . Then, the steam in the inner pan 2 is made to float up the pressure regulating ball 16 and is discharged to the outside.
[0018]
Further, a steam temperature sensor 18 (steam sensor) for detecting a steam temperature is provided in the steam discharge path 15 of the lid 4. The steam temperature sensor 18 outputs the detected temperature to the microcomputer 8.
[0019]
The microcomputer 8 includes a timer for measuring time, a RAM memory for storing the time measured by the timer, the temperature detected by the temperature sensors 7, 12, 12, and the determined rice cooking capacity, and the like. And a central processing unit (CPU) that executes the rice cooking process in cooperation with the timer.
[0020]
The microcomputer 8 performs the rice cooking operation by sequentially executing the steps of preheating, medium heating 1, 2 and 3, power control, spotting, and heat retention in accordance with the program stored in the ROM memory. Further, the microcomputer 8 performs the rice cooking capacity determination of the present invention during the middle and middle two steps, and sets the duty ratio and the like in the subsequent steps such as power control according to the determined rice cooking capacity, and sets the temperature. Appropriate rice cooking operation is performed according to the input from the sensors 7, 12 and the pressure sensor 13.
[0021]
Next, rice cooking control by the microcomputer 8 of the pressure rice cooker 1 will be described.
[0022]
First, the user stores the desired number of cups of rice and the amount of water required to cook the rice in the inner pot 2, sets the inner pot 2 on the main body 3, and then sets the desired rice after cooking. The rice hardness, the cooking time, etc. are set by operating the switches on the display panel 30 disposed on the front of the main body 3, and the rice cooking switch is pressed.
[0023]
Then, the microcomputer 8 starts the rice cooking flow and, as shown in FIG. 2, in step S1, starts energizing the induction heating coil 6, and adjusts the temperature of the inner pot 2 to about 50 ° C. Preheating is applied (preheating step).
[0024]
Then, after a lapse of a predetermined time, in step S2, electricity is supplied to the induction heating coil 6 with 100% (full power) power (medium wrapper step), and the rice cooking capacity determination described later is performed. Then, according to the determined rice cooking capacity, a temperature at which pressure is applied to the inner pot 2 via the solenoid 17 and the pressure regulator 14 and a time for determining that the dry-up is performed are set.
[0025]
Next, in step S3, the process waits until the temperature detected through the lid temperature sensor 12 reaches the set threshold value. When the temperature reaches the threshold value, in step S4, the solenoid 17 of the pressure regulator 14 is turned off. When activated, the pressure regulating ball 16 is disposed in the opening 15a to shut off the steam discharge path 15. As a result, the pressure regulating ball 16 closes the opening 15a with its own weight, seals the inside of the inner pot 2, and applies pressure.
[0026]
Thereafter, in step S5, in accordance with the pressure of Uchinabe in 2 detected via the pressure sensor 13, so that the pressure in the inner pot 2 is in the range of about 0.09 kg / cm ² of 0.11 kg / cm ² Next, the amount of electricity supplied to the induction heating coil 6 is controlled to control the pressure rice cooking (power control step).
[0027]
When the dry-up is detected by a known method, in step S6, after the pressure input by the pressure regulator 14 is released, the energization of the lid heater 11 disposed on the lid 4 is started, and the steaming and dewatering are performed for a predetermined time. The skipping (purple step) is performed, and the rice cooking is completed. When the rice cooking is completed, in step S7, the process shifts to a heat retaining process, similarly to a known pressure rice cooker (heat retaining step).
[0028]
Hereinafter, the rice cooking capacity determination operation by the microcomputer 8 will be described.
[0029]
As shown in FIG. 3, middle Pappa 1 is finished and the medium Pappa 2 step is started, transition temperature T of Pappa 2 medium from the migration temperature T ₂ detected temperature is medium Pappa 1 of the cover for the temperature sensor 12 and duration t ₁ to reach _3, the required time t ₂ required to reach the transition temperature T ₄ of the transition temperatures T ₁ medium Pappa from second detection temperature medium Pappa 1 steam temperature sensor 18, in package Pas 2 step , The heating output time t _IH during which the induction heating coil 6 is on is measured. Then, the required time _{t 1} to the side reaching the transition temperature _{T 3} or _{T 4} faster out of the required time _{t 2,} i.e. determined as a time determining the time required _{t 2 t SE} in the example of FIG. 3, N value according to the number 1 Is calculated. The transition temperature between the lid temperature sensor 12 and the steam temperature sensor 18 is set for each rice cooking menu as shown in FIG.
[0030]
N = t _SE × a + t _IH × b (Equation 1)
Here, it is assumed that the optimum values of the capacity discrimination coefficients a and b are obtained within the range of 1/2 to 1/32 by experiments.
[0031]
As described above, since the temperature is detected using the two temperature sensors 12 and 18, for example, the heat radiation plate 9 of the lid 4 is not properly attached, and the accuracy of the detected temperature of the lid temperature sensor 12 is low. Even in this case, the temperature detection accuracy is improved by performing accurate temperature detection by the steam temperature sensor 18 that captures the temperature of the steam generated from the food in the inner pan 2. In addition, since the rice cooking capacity is determined using the heating output time t _IH , more accurate rice cooking capacity determination is performed.
[0032]
After the completion of the two processes, four types of capacity determination of ranks S, M, L, and O are performed based on the N value based on the table shown in FIG. Threshold _{T YO1, T YO2, T YO3} when performing the capacity determination is rice types that cooking as shown in the table of FIG. 6, is set according to the amount. In this table, the threshold values for cooking rice porridge size L, rice porridge size H, brown rice size L, and brown rice size H are shown.
[0033]
【The invention's effect】
As is clear from the above description, in the rice cooker of the present invention, the steam sensor for detecting the steam temperature is provided in the steam discharge path, and the time required for the detected temperatures of the lid sensor and the steam sensor to reach each transition temperature is set. The required time on the side that quickly reached the transition temperature is determined as the determination time, and the rice cooking capacity determination is performed based on the determination time, so that the accurate transition temperature is detected, so that the stable rice cooking capacity determination can be performed and delicious. You can cook rice. In addition, since the steam sensor accurately detects the temperature of the steam generated from the object to be cooked, it is possible to detect boiling without lowering the transition temperature of the lid sensor as in a conventional rice cooker, and to reduce the risk of spilling.
[Brief description of the drawings]
FIG. 1 is a schematic view of a rice cooker according to the present invention.
FIG. 2 is a flowchart showing rice cooking control of the rice cooker of FIG.
FIG. 3 is a graph showing changes in detected temperatures of a lid temperature sensor 12 and a steam temperature sensor 18 in a middle wrapping process.
FIG. 4 is a table showing transition temperatures in a middle dad process.
FIG. 5 is a table showing capacity determination ranks corresponding to N values.
FIG. 6 is a table showing thresholds of N values used in discriminating the capacity of each rice cooking menu.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cooker, 2 ... Inner pot (cooking pot), 3 ... Main body, 4 ... Lid, 6 ... Induction heating coil (heating means), 8 ... Microcomputer (Control means), 12 ... Lid temperature sensor (Lid) Sensor), 15: steam discharge path, 18: steam temperature sensor (steam sensor).

Claims (2)

A cooking pan, a main body for housing the cooking pan, heating means for heating the cooking pan, a lid attached to the main body so as to be openable and closable, and an opening of the cooking pan, and provided on the lid. A lid sensor for detecting the temperature of the heat sink, and a rice cooker including control means for controlling the heating means,
A steam sensor that detects a steam temperature is provided in a steam discharge path provided inside the lid that discharges steam generated from inside the cooking pot to the outside of the lid,
The control means obtains each required time until the detected temperatures of the lid sensor and the steam sensor reach each transition temperature, obtains the required time on the side where the transition temperature reached the transition temperature earlier as a determination time, and determines the determination time. A rice cooker characterized in that a rice cooker capacity is determined based on a rice cooker. 2. The rice cooker according to claim 1, wherein, in the rice cooking capacity determination, the rice cooking capacity determination is performed based on a heating output time required during the required time until the transition temperature is reached, in addition to the determination time. 3. .

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