JPH0229217A - rice cooker - 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] [Object of the Invention] (Industrial Application Field) The present invention relates to a rice cooker that controls a heating operation for cooking rice based on the temperature of a pot detected by a temperature measuring means. In particular, the present invention relates to a rice cooker with an improved control system.

(Prior art) Conventionally, in a rice cooker, a magnetic shunt steel is attached to the outer bottom of the pot, and a permanent magnet that is attracted and held against a spring is provided on the magnetic shunt steel. When the temperature of the pot detected by the device reaches a preset cooking temperature, the permanent magnet is separated from the magnetic shunt steel in response to a sudden decrease in magnetic permeability, and the pot is heated by an interlocking switch that turns off in response to this separation. A configuration has been implemented in which power is cut off to the heater used for the purpose.

In addition, in conventional rice cookers, rice is cooked once to ensure that the rice becomes alpha-gelatinized and removes excess moisture, resulting in delicious rice. is provided. That is,
This device uses, for example, a timer device, and this timer device starts a timer operation for a certain period of time in conjunction with the power cutoff of the heater due to the turning off of the interlocking switch, and
The timer contact is turned on for a certain period of time at a predetermined timing, and a current conduction path for the heater is formed through the timer contact. Therefore, in such a rice cooker, the heater is cut off as the rice is cooked, and at a predetermined timing after the cutoff, the heater is turned on again for a certain period of time to heat the pot. Then the temperature is cooked.

(Problems to be Solved by the Invention) As in the conventional configuration described above, when the heater power-off timing, in other words, the termination timing of the heating operation for cooking rice, is controlled by magnetic shunt steel, While these properties vary depending on the characteristics of the magnetic steel, permanent magnets, and springs, as well as the state of adhesion between the magnetic shunt steel and the pot, the above characteristics and state of adhesion are uniform for each product. Since it is extremely difficult to heat the rice, there is a problem that the end timing of the heating operation is inaccurate, which may cause the rice to burn or, conversely, be insufficiently alpha-ized. There was a risk.

In addition, when adopting a conventional configuration that uses a timer device to cook at a temperature, the heating operation for cooking at the same temperature is always the same regardless of the rice cooking conditions such as the amount of rice cooked, the power supply voltage, and the outside temperature. The heating condition of the pot during cooking will vary according to the changes in the above conditions. ! 3
(heating temperature) will change. In particular, when the rice is cooked, the amount of water in the pot is relatively reduced, so if the heating temperature of the pot becomes high, the rice is very likely to burn.

The present invention has been made in view of the above circumstances, and its purpose is to be able to control the end timing of the heating operation for cooking rice extremely accurately, to prevent the rice from burning, and to prevent the rice from burning after the rice is cooked. To provide a rice cooker which can reliably alphanize rice by twice cooking the rice by reheating a pot and can effectively prevent the rice from burning at this temperature.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above objects, the present invention provides a heating means for heating a pot, a temperature measuring means for sensing the temperature of the pot, and a temperature measuring means for sensing the temperature of the pot. A means for monitoring the sensing output is provided, and the means detects a flat gradient in the monitored temperature of the pot, and the heating means for the pot is heated at a temperature value obtained by adding a predetermined temperature value to the detected temperature value. stopping, and then intermittently rotating the heating means at a temperature lower than the added temperature value;
The structure is such that a heating control means is provided.

(Function) When a pot containing rice and water is heated by a heating means, the pot temperature becomes stable after rising to a temperature corresponding to the boiling point temperature of the water. The flat slope continues for a period of time when the water in the pot is convecting. The control means detects the temperature of the pan when the change in pan temperature exhibits a flat gradient as described above through a temperature measuring means, and then adjusts the pan temperature to a predetermined temperature equal to the detected temperature value. The heating of the pot by the heating means is stopped at the temperature value D' obtained by adding the values.

In other words, the detected temperature value, which is the standard for when to stop heating the pot, is not a fixed value, but a value that corresponds to the boiling point temperature of the water in the pot, and depends on the amount of rice cooked, power supply voltage, outside temperature, etc. Since the value corresponds to the rice cooking conditions, it is possible to accurately control when to stop heating the pot.

On the other hand, the control means, after the heating of the pot as described above is stopped,
The pot is reheated by the heating means at a temperature lower than the additional temperature value D', that is, the pot is intermittently heated. As a result of heating at a relatively low temperature, the rice burns even though it is already cooked and the amount of water in the pot is relatively reduced. In addition to preventing this from occurring, it will also ensure that rice becomes alpha.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In Fig. 1, 1 is the main body of the rice cooker consisting of an inner case 2 and an outer case 3, 4 is a lid, 5 is a pot housed in the inner case 2, and 6 is a space between the bottoms of the inner case 2 and the pot 5. This is a heater that is a heating means disposed in the space. Reference numeral 7 denotes a cup-shaped heat-sensitive part which is provided so as to be elastically pressed against the outer bottom of the pot 5. A thermistor 8 serving as a temperature measuring means is enclosed inside the heat-sensitive part 7 by a heat-conductive mold member 9. The thermistor 8 is configured to sense the temperature of the pot 5. Reference numeral 10 denotes a case disposed at the outer bottom of the rice cooker main body 1, and a control circuit 11 serving as a control means whose circuit configuration is shown in FIG. 2 is housed inside the case.

Next, in FIG. 2, reference numeral 12 is an AC power source, and the heater 6 is connected between both terminals of the AC power source via a normally open relay switch 13. 14 is a drive circuit that turns on the relay switch 13 only when a signal "1" is input; 15;
16 is a start switch for starting rice cooking. When the start switch 16 is turned on, a signal ``1'' is sent to line L. " is output.

Reference numeral 17 denotes a pulse generator, which consists of a shaping circuit 18 that shapes the waveform of the output of the AC power supply 12, and a frequency dividing circuit 19 that divides the frequency of the output of this shaping circuit 18. It is configured to output a clock pulse Pc to line L2 at regular intervals. Now, although the control circuit 11 will be explained below in terms of hardware using logic circuits and functional blocks, it goes without saying that the same functions as the control circuit 11 may be obtained by a microcomputer program.

That is, first, an overview of each functional block will be explained. 2
0.21 is a counter that counts the pulses input to the clock input terminal CK, and these are cleared when a signal "1" is input to the clear terminal CL. 22 to 3
Reference numeral 1 denotes a comparison section, which outputs a signal "1" when the input value of the terminal A is larger than the input value of the terminal B, and outputs a signal "0" in other cases. 32 to 44 are first to thirteenth storage units, in which numerical values as described below are stored in advance. First storage unit 32 serving as a lower limit storage unit... Pot temperature lower limit D32 ('C) (for example, 90°C), second storage unit 33 serving as an upper limit storage unit...
... Pot temperature upper limit D3i ('C) (for example, 110℃)
, 3rd. Fourth storage unit 34.35... Measuring time value T34 used for measuring the amount of cooked rice. T1. [Seconds] (However, T, , < T, U), 5th. 6th. Seventh storage unit 36, 37, 38. ...Additional temperature values D36, D37. D38 [”C) (However,
D) 6 < D 37 < D 3g), 8th. 9th.
10th storage section 39.40.41...Additional temperature value for 1 degree cooking D391 D4°, D41('C) (However, % D39<D aO<D4+・D39
<D36・D40kuD 37. D a+< D 3
8), 11th. 12th storage unit 42, 43...
・Measurement temperature value D4° used for measuring the amount of cooked rice,
D43("C) (however, D4□<1)43<D3゜),
Thirteenth storage unit 44...Timer time value T44
[Seconds] (In this embodiment, it is set to a value corresponding to, for example, 15 minutes.) On the other hand, 1.45 is an A-D converter that receives the resistance value of the thermistor 8 as an input, and this is connected to its terminal φ. Line L2
The input resistance value is digitally converted every time a clock pulse Pc is received from. Reference numeral 46 denotes a temperature converter which is a monitoring means for receiving the output of the A-reverse converter 45 and converting it into a digital temperature value. Sd to line L,
Output to. 47, 48, and 49 are shift registers, and each time a pulse is input to the terminal φ, the terminal A is
The input value for is transferred to terminal B and output. Reference numeral 50 denotes a delay circuit, which has a delay time longer than the time required for a signal input to terminal A of the shift register 47 at the front stage to be output from terminal B of the shift register 49 at the last stage.

51 and 52 are subtraction units, which subtract the input value of the terminal B from the input value of the terminal A and output the subtraction result values, respectively. 53 is an adder, and 54 is an auxiliary adder. These add terminals A and B when a pulse is input to the terminal CK.
The human power values for each are added and the addition result values are stored and output at the same time. Reference numeral 55 denotes a temperature storage section at the time of rising, which stores the input value for the terminal CK when a pulse is input to the terminal CK. Reference numerals 56 to 62 designate transfer gates that exhibit low impedance and allow signals to pass only when a signal "1" is input to their gate terminals. Further, 63 is a monostable multivibrator, 64 to 66 are R-S flip-flops, and 67 to 75 are AN
D circuit, 76 to 78 are OR circuits, 79 to 85 are NO
It is a T circuit.

Next, the specific signal flow shown in FIG. 2 will be described with reference to its effect and the temporal change characteristic diagram of the temperature of w45 shown in FIG. 3. Now, when the lid 4 is closed with a predetermined amount of rice and water stored in the pot 5 and the start switch 16 is turned on, a signal "1" is output to the line L1. Then, this signal "1" causes the counter 20 to
, 21 are cleared, and the R-S flip-flops 64 and 65 are reset, and the signal "
Further, the R-S flip-flop 66 is set via the OR circuit 77, and the signal "1" from its output terminal Q is supplied to the drive circuit 14. Therefore, the relay switch 13 is turned on by the drive circuit 14, and the AC power supply 12 is connected to the heater 6.
The heater 6 starts to energize the pot 5.
The rice cooking operation of heating the rice begins.

At this time, the comparison section 29 connects the terminal A to the thirteenth storage section 4.
The timer time value T44 from 4 is input, and the terminal B
Since the initial value (i.e. zero) of the counter 21 is input manually, the signal "1" is outputted, and this signal "1" is
It is applied to one input terminal of the D circuit 73. This AND
Since the signal "0" from the R-S flip-flop 65 is inverted to a signal "1" by the NOT circuit 84 and input to the other input terminal of the circuit 73, the HAND circuit 73
A signal "1" is then given to the display circuit 15, and as a result, in response to the start of the rice cooking operation, the display circuit 15 lights up a rice cooking indicator lamp (not shown) to indicate that the rice cooking operation is being performed. do.

With the start of such a rice cooking operation, the temperature of the pot 5 rises as shown in FIG. 3, and a temperature value signal Sd corresponding to the temperature is sent from the temperature converter 46 with a period of 1 second (period of the clock pulse Pc).
will be output. Then, in accordance with the temperature rise of the steel 5, first the counter 20 and the comparison parts 23, 24, 25
．． 26 as well as the third and fourth. 11th. Each twelfth storage unit 3
Cooked rice amount measuring section 86 comprising 4,35°42,43, etc.
works.

In the rice cooking amount measurement section 86, the comparison section 22 is configured such that the temperature value signal Sd input to the terminal A is first with respect to the terminal B.
The signal "0" is output until time t1 when the measurement temperature value D4□ inputted from the 1 storage unit 42 becomes larger, and the signal "1" is output after time t1.

Further, the comparator 23 compares the temperature value signal Sd input to the terminal B with the measurement temperature value D4 input to the terminal A from the twelfth storage unit 43. The signal "1" is output until the time t2 becomes larger, and the signal "0" is output after the time t2. Therefore, both comparison units 22 .
Since the signal "1" is outputted from 23 and given to the AND circuit 67, the clock pulse Pc from the line L2 passes through the AND circuit 67 and is given to the clock input terminals C and K of the counter 20 only during this period. As a result, the count result value C20 of the counter 20 becomes a value corresponding to the time required for the temperature of the pot 5 to rise from the measurement temperature value D42 to the measurement temperature value D43 (time from time t1 to t2). . The count result value CZO has a property of increasing or decreasing in proportion to the amount of cooked rice, and the magnitude of the amount of cooked rice is determined based on this count result value C2°.

That is, the count result value C20 from the counter 20 is
3rd by 4.25. Measurement time value T from each fourth storage unit 34.35 34. T 35 (T 34 <
T3. ) are compared respectively. At this time, the comparator 24 outputs a signal "0" when the count result value C20 is less than or equal to the measurement time value T34 (in other words, when the amount of rice cooked is relatively "small"); The signal “1” is output by the NOT circuit 79.
” and then output to line L4. Further, the comparison unit 25 determines that the count result value C20 is the measurement time value T6. (in other words, when the amount of cooked rice is relatively "large"), a signal "1" is output, and this signal "1" is output to line L6.

Then, the count result value C20 is the measurement time value T1. When the measurement time value T34 is exceeded (in other words, when the rice cooking amount is "medium"), a signal "1" is output from the comparator 24 and applied to one input terminal of the AND circuit 68. Then, a signal "0" is output from the comparator 25, which is inverted to a signal "1" by the NOT circuit 80, and then applied to the other input terminal of the AND circuit 68, so that the AND circuit 68 to line L, signal "
1" is output.

As described above, the rice cooking amount measuring section 86 measures the amount of rice cooking based on the time required for the temperature of the pot 5 to rise from the measuring temperature value D4□ to D43. At this time, each line L4. L9. L6 are transfer gates 56 and 59, 57 and 60, 58 and 61 respectively.
is connected to each gate terminal of , so the amount of rice cooked is
If it is "small", the transfer game) 56.59 is the addition temperature value stored in the 5th and 8th storage sections 36.39, respectively, and the addition temperature value DS9 for cooking 6.1 degrees is passed. If the amount of cooked rice is "medium", transfer gate 57.6.0 is set to 6th. Added temperature value D37. from the ninth storage unit 37°40. If the additional temperature value D40 for double-cooking is allowed to pass, and the amount of cooked rice is "large", the transfer gate 58.61 is set to the 7th and 10th storage sections 38.41.
The additional temperature value D41 for 8° 1 degree cooking is allowed to pass.

After that, when the temperature of the pot 5 rises and the temperature value signal Sd exceeds the pot temperature lower limit value 2 stored in the first storage section 32, the temperature value signal Sd is received at the terminal A. Terminal B
The output of the comparator 26 that receives the pot temperature lower limit value D32 is inverted from the signal "0" to the signal "1". Further, the temperature of the pot 5 further increases and the temperature value signal Sd is stored in the second storage section 33 as the pot temperature upper limit D3. When the temperature exceeds 0, the output of the comparator 27 which receives the temperature value signal Sd at the terminal A and receives the pot temperature upper limit value D33 at the terminal B becomes the signal "0".
” will be reversed to “1”. At this time, the three-input type AND circuit 70 has the comparison section 26 at its first input terminal.
The second input terminal receives the output from the comparator 27 via the NOT circuit 81, and the third input terminal receives the output from the R-S flip-flop 65 via the NOT circuit 82. It is set up so that you can receive it.

At this point, the signal “0” is output from the R-S flip-flop 65.
” is output, the comparator 26 outputs the signal “
During the period in which the signal "1" is output and the signal "0" is output from the comparator 27, all inputs to the AND circuit 70 become the signal "1". In short, the AND circuit 70 outputs a signal "1" only when the temperature of the pot 5 is between the pot temperature lower limit value D'31 and the pot temperature upper limit value D'31, and sends this signal "1" to the transfer gate 62. It will be given to the gate terminal of.

Now, when the temperature of the pot 5 exceeds the pot temperature lower limit value D32, the transfer gate 62 outputs a signal (in this case, the clock pulse Pc
), the comparison unit 2.8. Shift register 47. 48, 49° delay circuit 50. Subtraction section 5
1.52, the rising temperature value storage section 55, and the like, the arithmetic section 87 comes into operation. In the arithmetic unit 87, the shift register 47 at the front stage transfers the latest temperature value signal Sd input to its terminal A to the terminal B every time the terminal φ receives a clock pulse Pc, and thereby transfers the latest temperature value signal Sd input from the terminal B to the terminal B. Temperature value signal Sd at a time point 1 second ago.

Output one after another. The next stage shift register 48 receives a temperature value signal S at a time point one second before input to its terminal A.
dl is transferred to the terminal B every time the clock pulse Pc is received at the terminal φ, and the temperature value signal Sd2 at the time point two seconds ago is successively outputted from the terminal B, and the shift register 49 at the last stage is Similarly to the above, the temperature value signal Sd at the time point 3 seconds ago is output one after another from the terminal B. Subtraction section 51
subtracts the temperature value signal Sd at the time 3 seconds ago from the temperature value signal Sd2 at the time 2 seconds ago, and calculates the subtraction result (i.e., the temperature value of the pot 5 from the time 3 seconds ago until 1 second has elapsed). temperature gradient) is applied to terminal B of the comparing section 28. The subtraction unit 52 subtracts the temperature value signal Sd2 at the time point two seconds ago from the temperature value signal Sd at the time point one second ago, and the subtraction result (i.e., the temperature value signal Sd2 at the time point two seconds ago) temperature gradient of the pot 5) is applied to the terminal A of the comparing section 28. If the subtraction result by the subtraction unit 52 becomes larger than the subtraction result by the subtraction unit 51, that is, at time t3 in FIG. When the voltage starts to rise, the comparator 28 outputs a signal “1” and applies this signal “1” to one input terminal of the AND circuit 69. This AND
When the clock pulse Pc that has passed through the transfer gate 62 is applied to the other input terminal of the circuit 69 via the delay circuit 50, the R-S flip-flop 64 is activated by the signal "1" output from the AND circuit 69. It is set and a signal "1" is output from the output terminal Q. Then, the monostable multi-pipe rake 63 is triggered to output a pulse signal, and the rising temperature value storage section 55, which receives this pulse signal at the terminal CK, stores the temperature value signal Sd2 from the shift register 48 at the rising edge. It comes to be stored as a temperature value Ds. At the same time, the adder 53 and the auxiliary adder 54, which receive the pulse signal at the terminal CK, calculate the rising temperature value Ds input to each terminal B and the signal value input to each terminal A. Each addition result value U2. and U, 4, and outputs the addition result values U53 and U54. At this time, the fifth to seventh terminals are connected to the terminal A of the adding section 53.
The added temperature values D stored in the storage units 36 to 38 of
,6. D, 7°I) is the rice cooking amount measuring section 8
The additional temperature value corresponding to the measurement result of No. 6 is given to the terminal A of the auxiliary addition section 54, and the additional temperature value for one-time cooking stored in the eighth to tenth storage sections 39 to 41 is given to the terminal A of the auxiliary addition section 54. , D4
o.

Among D4□, an additional temperature value for one-time cooking is given according to the measurement result of the rice cooking amount measuring section 86.

Furthermore, when the R-S flip-flop 64 is set at time t, the signal "1" from its output terminal Q is applied to one input terminal of the AND circuit 72 via the OR circuit 76. The AND circuit 72 allows the passage of the clock pulse Pc applied to the other input terminal, and the counter 21 starts a counting operation. The timer 88 made up of the comparison section 29 and the thirteenth storage section 44 starts its timer operation from time t.

Now, the addition result value U53 of the adding section 53 is compared with the temperature value signal Sd in the comparing section 30, and at time t4, the temperature value signal Sd is compared with the temperature value signal Sd.
When d exceeds the addition result value U53, the comparator 3
A signal “1” is output from “0” and applied to one input terminal of the AND circuit 75.

At this time, the other input terminal of the AND circuit 75 has R.
- Since the signal “1” is given from the S flip-flop 64, the AND circuit 75 outputs the signal “1”, and this signal “1” resets the R-S flip-flop 66 via the OR circuit 78. It is applied to input terminal R. Therefore, the R-S flip-flop 66 is reset and the supply of the signal "1" to the drive circuit 14 is stopped.
The relay switch 13 is turned off and the heater 6 is cut off,
After this, the period shifts to an uneven period controlled by the timer 88.

During this uneven period, the addition result value U of the auxiliary addition section 54
54, so-called one-time cooking is performed.

That is, the addition result value U, 4 of the auxiliary addition section 54 is the comparison section 31.
At time t, the temperature value signal Sd is compared with the temperature value signal Sd at time t as the temperature of the pot 5 decreases due to the power outage of the heater 6.
When becomes equal to the addition result value U54, a signal "1" is output from the comparator 31 and the third
given to the input terminal. . At this time, the AND circuit 7
4, 1st. The second input terminal has a comparator 29 and an R-S, respectively.
Since the signal "1" is given from the flip-flop 64, the AND circuit 74 outputs the signal "1", and this signal "1" is sent to the set of the R-S flip-flop 66 via the OR circuit 77. It is applied to input terminal S. Therefore, R
-S flip-flop 66 is set and drive circuit 14
Since the signal ``1'' is again applied to , the relay switch 13 is turned on and the heater 6 is energized again, and the pot 5 is reheated to perform one cooking operation.

After this, the temperature value signal Sd is changed to the addition result value υ6. , the heater 6 is cut off in the same manner as described above, and the temperature value signal Sd becomes equal to the addition result value U54 of the auxiliary addition section 54 as the temperature of the pot 5 decreases due to this cutoff. At times, the operation of energizing the heater 6 as described above is repeated. Then, at time t6, which is 15 minutes after time t3, the count value of the counter 29 becomes equal to the timer time value T44 stored in the thirteenth storage section 44, so that the comparison section 29 outputs the signal rOJ. become. Then, the signal "0" is changed to the signal "1" by the NOT circuit 85.
'' is inverted and then applied to the reset input terminal R of the R-S flip-flop 66 via the OR circuit 78.
Since the -S flip-flop 66 is reset, the relay switch 13 is turned off by the drive circuit 14 and the heater 6 is cut off. At the same time, the output of the AND circuit 73 which received the signal "0" from the comparator 29 becomes the signal "1".
” to signal “0”, the display circuit 15 turns off the rice cooking display lamp (not shown).

As described above, rice is cooked when the start switch 16 is turned on, but when the start switch 16 is turned on with no rice or water stored in the pot 5, a so-called dry cooking state occurs. It is dangerous.

However, in this embodiment, the above-mentioned danger is prevented as described below. That is, in the case of dry cooking, the temperature of the pot 5 rises as shown by the two-dot chain line in FIG. 3, and the rising temperature value Ds no longer exists. As the temperature rises, the temperature value signal S
d is the pot temperature upper limit value D33 stored in the second storage unit 33
When the value exceeds 1, the comparator 27 outputs the signal "1" as described above, and the AND circuit 70 outputs the signal "1".
0" is now output, and the transfer gate 62
is turned off, and at the same time, the signal "1" from the comparator 27 is applied to one input terminal of the AND circuit 71. At this time, the signal "0" from the R-S flip-flop 64 is input to the other input terminal of the AND circuit 71.
Since the signal rlJ is applied via the OT circuit 83, the AND circuit 71 outputs the signal rlJ. Then the above signal “
1” is connected to the R-S flip-flop 6 via the OR circuit 78.
6, the heater 6 is powered off in the same way as described above, and at the same time, the signal rlJ is inverted to signal "0" by the NOT circuit 84 and output to the AND circuit 73. Since the signal is applied to one input terminal, the AND circuit 73 outputs a signal "0" and the rice cooking display lamp is turned off. In this way, pot 5
The temperature of 1. is the upper limit of the pot temperature. The heater 6 is cut off when the temperature exceeds the limit, thereby preventing the risk of overheating.

According to the present embodiment described above, the additional temperature value D is preset to the rising temperature value Ds when the temperature gradient of the pot 5 starts to rise from a flat state.

D38 is selectively added to obtain the addition result value U5.
3, and when the temperature value signal Sd obtained by measuring the temperature of the pot 5 exceeds the above-mentioned addition result value U53, the heater 6 is cut off. The rising temperature value Ds, which is the standard, is not a fixed value, but is a value obtained by measuring the actual temperature gradient of the pot 5 between the pot temperature lower limit value D32 and the pot temperature upper limit value D33 each time. Therefore, there is a contact state between the pot 5 and the thermistor 8.

It is possible to accurately control the power-off timing of the heater 6 without being influenced by error factors such as ambient temperature, secular changes in the characteristics of the thermistor 8, variations during mass production, and changes in atmospheric pressure. Moreover, in this case, the added temperature value D)6
1 D 371 D 311 is selected by the rice cooking amount measuring section 8
6, the power-off timing of the heater 6 can be controlled more accurately in accordance with the actual amount of rice cooked.

Further, according to this embodiment, one-time cooking is performed not by time control as in the conventional case but by temperature control based on the temperature value Ds at the time of rising. 1 depending on the actual amount of rice cooked
Since the re-energization timing for the heater 6 for double-cooking is changed, it is possible to accurately control single-cooking. Particularly, during the one-time cooking, a preset additional temperature value D3 for one-time cooking is added to the reference temperature value Ds. .

D4o, D4. The heater 6 is intermittently energized based on the addition result value U, which is obtained by selectively adding one of the above-mentioned additional temperature values D39°D4°,
D41 is the addition result value U for setting the finished cooking temperature;
6. Additional temperature value corresponding to 3. Since these values are lower than D38, the one-time cooking heating is performed at a temperature lower than the rice cooking end temperature (Usi). Therefore, as a result of heating the rice once at a relatively low temperature, the rice is in a fully cooked state when the pot 5 is heated.
Even though the amount of water in the rice is relatively reduced, the rice is effectively prevented from burning, and the grain formation of the rice is reliably promoted.

Furthermore, according to this embodiment, until the temperature of the pot 5 exceeds the pot temperature lower limit value D3°, the rising temperature value D s D
Since the configuration is such that the calculation for determining I is stopped, when the temperature of the pot 5 rises as indicated by the center line in FIG. 3, and at the time indicated by B in FIG. There is no possibility that the temperature value (the point at which the temperature starts to be transmitted to the water) will be mistakenly recognized as the rising temperature value, and therefore there is no possibility of malfunction.

Incidentally, in the above embodiment, the pot 5 is reheated multiple times when cooking once, but in this case, the additional temperature value for once-cooking at each time of reheating is made different. Also good. Furthermore, in the above embodiment,
Of course, it is also possible to perform a heat retention process after the unevenness period ends.

[Effects of the Invention] According to the present invention, as is clear from the above description,
The end timing of the heating operation for cooking rice can be controlled extremely accurately without being affected by the contact state between the pot and the temperature sensor 9, the ambient temperature, etc., thereby preventing the rice from burning. Moreover, to provide a rice cooker that can reliably alpha-gelatize rice by reheating the pot after the rice is cooked, and can effectively prevent the rice from burning during this one-time cooking. I can do it.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention; Fig. 1 is a partially cutaway side view of the rice cooker, Fig. 2 is a block diagram showing the electrical configuration, and Fig. 3 shows the temperature change state of the pot. FIG. In the figure, 5 is a pot, 6 is a heater (heating means), 8 is a thermistor (temperature measuring means), 11 is a control circuit (control means), 3
2 is a first storage unit (lower limit value storage unit), 33 is a second storage unit (upper limit value storage unit), 46 is a temperature converter, (monitoring means)
, 53 is an adder, 54 is an auxiliary adder, 86 is a cooked rice amount measuring unit, 87 is an arithmetic unit, and 88 is a timer.

Claims (1)

[Claims] 1. A heating means for heating the pot, a temperature measuring means for sensing the temperature of the pot, a means for monitoring the sensing output from the temperature measuring means, and a temperature change of the pot monitored by this means having a flat slope. control means for detecting and stopping the heating means for the pot at a temperature value obtained by adding a predetermined temperature value to the detected temperature value, and thereafter reheating the heating means intermittently at a temperature lower than the added temperature value; A rice cooker characterized by comprising: