JPS6192633A - 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 [Technical Field of the Invention] The present invention relates to a rice cooker that automatically prepares porridge.

[Technical background of the invention and its problems]

As is well known, with J3 rice cookers, the inside of the pot exhibits a so-called dry-up state (a state in which the water inside the steel is almost completely absorbed by the rice), and the pot temperature drops to the boiling point of the water. The rice cooker is configured to detect when the soil is rapidly leaking as described above, cut off the power to the heater for heating the pot, and thereby terminate the rice cooking operation.

In other words, in a rice cooker with such a conventional configuration, the heater cannot be automatically turned off while the moisture in the steel remains unabsorbed by the rice, and therefore it is impossible to automatically prepare porridge at all. It was impossible. In addition, in conventional rice cookers,
Even after the water in the pot boils Br1, the heater output is maintained as it is, so the heater's I
Even if you try to make porridge by manually operating the GI-den, the water will boil! ! In reality, it was difficult to make porridge even by manual operation because the heater output was too large and the hot water in the river boiled over.

(Object of the invention) The present invention has been made in view of the above-mentioned conventional circumstances, and
The purpose of this is to be able to automatically make porridge without boiling over water, and also to ensure stable detection of boiling water in the steel, which is essential for such automatic porridge cooking. It is an object of the present invention to provide a rice cooker that has effects such as being able to cook rice porridge.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention has an object of the present invention, in which during the porridge cooking operation, when the time set in the first timer means has elapsed from the time when the temperature of the steel reaches a predetermined temperature slightly lower than the boiling point temperature of water. It is determined that the steel water has boiled, and the output of the heater is automatically decreased based on the determination result, and when the time set in the second timer means has elapsed after the decrease in the heater output, the heater is activated. The power is automatically cut off.

[Embodiments of the invention]

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 2, 1 is an inner frame 2. The main body of the rice cooker consists of an outer frame 3, etc., 4 is a lid, 5 is a steel disposed inside the inner frame 2, 6 is a heater for heating this steel 5, 7 is an operation panel, and 8 is a temperature control panel for the bottom of the steel 5. Detection means provided for detection is, for example, a thermistor. Reference numeral 9 denotes a case disposed on the outer bottom of the rice cooker main body 1, and inside the case 9, power supply/disconnection of the heater 6 is controlled based on the temperature detected by the thermistor 8 and input from the operation panel 7. A rice cooking control circuit 10 or 7 is housed therein.

The rice cooking control circuit 10 is configured to be able to execute and control not only the normal rice cooking operation and warming operation but also the porridge cooking operation. The related circuitry of the directly related porridge-cooking operation control is shown.

In FIG. 1, reference numeral 11 denotes a relay contact, which is connected between both terminals of an AC power source 12 via the heater 6 in series. Reference numeral 13 denotes a coupler consisting of a light emitting diode 13a and a phototransistor 13b, to which the half-wave voltage of the AC power source 12 is applied via a diode 14 and a resistor 15. Reference numeral 16 denotes a DC constant voltage circuit that receives the output of the AC power supply 12, and power is supplied from this DC constant voltage circuit 16 to each circuit described below.

That is, 17 is the output of the A/C coupler 13 (AC power 11
112 is a waveform shaping circuit that shapes the voltage output (corresponding to the half-wave output) into a rectangular wave, and 18 is a frequency dividing circuit that divides the output of this waveform shaping circuit 17 to generate, for example, a clock pulse P18 with a period of 1 second. be.

A-1) conversion circuit 19 receives the output of the thermistor 8, and outputs a digital temperature signal 819 corresponding to the fifth temperature detected by the thermistor 8. 20 is a first memory circuit which stores a predetermined temperature slightly lower than the boiling point temperature of water, for example 90° C., as a digital temperature signal S2o; 21 stores an upper limit temperature, for example 120° C., as a digital temperature signal S21. This is the second memory circuit made up of the following.

Further, 22 is a third storage circuit that stores a certain period of time, for example 4 minutes, as a digital la time signal S22, and 23 is a fourth storage circuit that stores a certain period of time, for example 10 minutes, as a digital time signal 823. The circuit 24 stores a certain period of time, for example 30 minutes, as a digital field time signal 824,
25 is a sixth storage circuit that stores a certain period of time, for example 30 seconds, as a digital time signal 828; 26 stores a certain period of time, for example 15 seconds, as a digital time signal 82G. This is the seventh memory circuit consisting of. 27, 28, 29, 30, 31, 32 and 33 are comparison circuits, and each input value NA, NB for input terminals A and B is
A high level signal is output when the relationship lfiNA≧NB, and a low level signal is output when the relationship N A <Ns. Reference numerals 34 and 35 are trigger circuits that output pulses (34 and P3S) when receiving high level signals from the corresponding comparison circuits 27 and 28, respectively. 36 is a pulse generation circuit, which is connected to the operation panel 7.
A start pulse P36 is output when the momentary type start switch 7a provided at is turned on. 37 is a counter which, when reset terminal 1 receives the start pulse P3[1, sets the counter 1-1 to ``0''.
”, and counts up every time the clock pulse PI8 is received at the reverse terminal CK.
The count value is output as a numerical signal S3□. 38
is a cycle counter, which also counts when it receives a start pulse P36 at the reset terminal R (resets the direct signal to 0, and outputs a clock pulse P18 to the clock terminal GK).
It repeats the operation of counting up and counting up to a value equivalent to 60 seconds each time a signal is received, and outputs the count 1-value as a numerical signal S3[1.

Also, 39.40 and 41 are R-S flip 70 knobs,
42, 43, 44, 45 and 46 are AND circuits, 47 and 48 are OR circuits, and 49 is an inverter. and,
Reference numeral 50 denotes an output circuit serving as an adjusting means, which turns on the relay contact 11 when a high level signal is input. In this embodiment, the thermistor 8. A-D conversion circuit 1
9. First memory circuit 20. The comparison circuit 27 and the trigger circuit 34 constitute a signal output means 51, and the signals 1 to 34 from the trigger circuit 3/I correspond to auxiliary signals in Kokumei. Further, the third storage circuit 22. The comparison circuit 29 and the counter 37 constitute a first timer means 52A, and the fifth memory circuit 24. Comparison circuit 3
1. The counter 37 and the inverter 49 constitute the second timer means 52B, and the sixth memory circuit 25. 7th
storage circuit 26, comparison circuit 3.2.33. The control means 5 is controlled by a cycle counter 38 and an AND circuit 45,46.
3 are made up.

Next, the operation of the above structure will be explained with reference also to FIGS. 3 and 4. In addition, FIG. 3 shows the time change characteristics of the temperature detected by the thermistor 8 (that is, the temperature of the steel 5),
The figure shows the temporal change characteristics of the outlet of the heater 6. Now, when rice and a predetermined amount of water necessary for cooking this rice into porridge are stored in the steel 5, and the start switch 7a is turned on in this state, a start pulse P3 is generated from the pulse generating circuit 36.
is output, and this start pulse P3G causes R-S
The flip 70 knobs 39, 40, and 41 are reset, and the counter 37 and cycle counter 3 days are reset. As a result, the AND circuits 43 and 44 receive a low level signal from each reset output terminal 0 of the R-87 lip flop 40 and 41 at one input terminal, respectively, and block passage of the clock pulse PI8 from the frequency divider circuit 18. Therefore, the count values of the counter 37 and the cycle counter 38 are held in rOJ. For this reason,
Numerical signals 837.83 from each of the above counters 37 and 38
8 and the time signals 822 to 32G from the third to seventh storage circuits 22 to 26, 82 a >S23
>S22 >83 r and Szs >S2 s >S3
The relationship a is established, and high level signals are output from all of the comparison circuits 29 to 33.

Therefore, as a result, the AND circuit 42 which receives the high level signal from the OR circuit 48 and the high level signal from the set output terminal Q of the R-S flip-flop 39 outputs a high level signal, and receives this high level signal. Output circuit 5
0 turns on the relay contact 11, and in response, the heater 6 turns on.
is energized and heating of the steel 5 begins. As the heating of the steel 5 progresses, that is, the porridge cooking operation progresses, the temperature detected by the thermistor 8 rises to 90°C, and 8-1) the temperature signal 819 from the conversion circuit 19 and the first memory circuit 20 When the relationship between S19≧Szn and the temperature signal 320 from
At time [l] in FIGS. 3 and 4, the output of the comparator circuit 27 is inverted to a high level signal, and the auxiliary signals 1 to 4 are output from the C trigger circuit 34, so this trigger pulse P3a R-S flip 70 tube 40.4
1 is reset. Then, the AND circuits 43 and 44 receive a high level signal from each reset output terminal Q of the R-87 lip flops 40 and 41, and output a clock pulse P.
ls is allowed to pass, and the counter 37 and cycle counter 38 start a timer operation in which the counter 37 and the cycle counter 38 count up every second. Then, when time 12, which is 4 minutes corresponding to the time set in the first timer means 52Δ after this time tl, passes, the counter 3
Since the @value signal S37 from 7 and the time signal h 322 (corresponding to 4 minutes) from the third storage circuit 22 have a relationship of S3□>S22, the output of the comparator circuit 29 is low as the boiling signal. Invert to level signal. At this time, allt2 comics have 6 more
In the period up to time [3 (time 10 minutes have passed from time t1) when minutes have passed, C is the numerical signal S3□
Since the time signal MSz3 (equivalent to 10 minutes) from the fourth storage circuit 23 has a relationship of 837≦323, the comparator circuit 30 continues to output a high level signal. Therefore, the AND circuit 45 continues to allow the output signal from the comparator circuit 32 to pass through, but the comparator circuit 32 receives the value Ia No. 838 from the cycle counter 38 (from rOJ to "60" in a 60-second period). (Sequentially increasing numerical signal)
and the time signal 82S (equivalent to 30 seconds) from the sixth storage circuit 25 are configured to output a high level signal only during a period in which the relationship of 838≦82° is satisfied. Therefore, the AND circuit 45
The operation of outputting a high level signal for 30 seconds and then outputting a 1-level signal for 30 seconds is repeated. Then, the output circuit 50 repeats the operation of turning on the relay contact 11 for 30 seconds and then turning it off for 30 seconds, and as a result, during the period from time t2 to t3, the heater 6 is energized at a duty ratio of 50%. Then, the output of the heater 6 is reduced to 50% of the previous output. Then, after time t3, which is 10 minutes after time t1, the counter 37 outputs a numerical signal S3? and the time signal S23 from the fourth storage circuit 23 have a relationship of S3 r > S23, so the output of the comparison circuit 30 is inverted to a low level signal, and the AND circuit 45 outputs the output signal from the comparison circuit 32. will now prevent the passage of. This time corresponds to the time set in the second timer means 52B after 3.
During WJ up to time t4 when 0 minutes have elapsed (time 30 minutes have elapsed from time 1), the above numerical value 4g
@S, 3 r and the time signal 5 from the fifth storage circuit 24
24 (corresponding to 30 minutes) satisfies the relationship S'3 r≦824, so the comparator circuit 31 continues to output a high-level signal. Therefore, the AND circuit 46
This comparator circuit 33 continues to allow the passage of the output signal from the cycle counter 38, but the comparison circuit 33 receives the numerical signal 3 from the cycle counter 38
38 and the time signal 82G (15
It outputs a high level signal for a period during which 838≦Sz6 (equivalent to seconds) satisfies the relationship 838≦Sz6, so the AND circuit 46 outputs a high level signal for 15 seconds and then a low level signal for 45 seconds. Actions become repetitive. Therefore, in this case, the output circuit 50 repeats the operation of turning on the relay contact 11 for 15 seconds and then turning it off for 45 seconds, and as a result, during the period from time (3 to %, and the output of the heater 6 is reduced to 25% of the rated value.Then, when 30 minutes have passed since time t1, a numerical signal S37 from the counter 37 is output. and the time signal 32.4 from the fifth storage circuit 24 are S3 r > 3
24, the output of the comparison circuit 31 is inverted to a low level signal, and the AND circuit 45 blocks the output signal from the comparison circuit 33 from passing. At the same time, the low level signal is inverted by the inverter 49 to a high level signal which is a stop signal, so the three knobs of the R-S flip 70 are reset, and in response, the output circuit 50 turns off the relay contact 11. When this state is maintained, the heater 6 is cut off, and the porridge cooking operation is completed.

In addition, during such a porridge cooking operation, if the amount of water stored in the steel 5 is insufficient, the inside of the wAb will be in a dry-up state before reaching time t4, and the temperature will rise to 100°C or higher. However, in this case, when the temperature detected by the thermistor 8 exceeds the upper limit temperature of 120°C stored in the second memory circuit 21 (for your reference), , that is, the temperature signal S1 from the A-D conversion circuit 19 and the temperature No. 18 821 from the second storage circuit 21.
When the relationship S19≧821 holds, the comparator circuit 2
Since the output of 8 is inverted to a high level signal and the trigger pulse P3S is output from the trigger circuit 35, the R-S flip 70 knob 39 is reset by this trigger pulse P3S. Therefore, the temperature of steel 5 is the upper limit temperature of 120
When the temperature exceeds "C", the heater 6 is cut off by the output circuit 50, thereby reliably preventing the overheating accident as described above.

According to the above embodiment, after the start of the porridge cooking operation in response to the ON operation of the start switch 7a, until the low level signal as the boiling signal is output from the comparison circuit 29 in the first timer means 52Δ. between (in other words, steel 5
(until the water reaches a boiling state), the heater 6 generates heat at its rated output to quickly bring it to a boil, and after such boiling, the output of the heater 6 is reduced. The configuration is such that the heater 6 is automatically cut off after being held for 30 minutes until a high level signal as a stop signal is output from the four inverters in the timer means 52B. Therefore, just by turning on the start switch 7a, porridge can be automatically prepared in the shortest possible time, and in this case,
After the water in the steel 5 boils, the output of the heater 6 does not become excessive as in the conventional case, and there is no risk of the hot water boiling over. In particular, in this embodiment, a boiling signal indicating that the water in the steel 5 has reached a boiling state is sent to the first timer means 52A when the temperature of the steel 5 reaches 90° C., which is much lower than the boiling point temperature of water. It is configured to start running after a set 4 minutes have elapsed, and after that, the moving bed described below can be performed.

In other words, the water is boiling! In general, it is difficult to quickly detect that a state has occurred (iW), and the cost is high.

However, according to the above configuration, if the heater 6 continues to generate heat at the rated output for a suitable period of time (4 minutes in this embodiment) after the temperature of w45 reaches 90°C, the water in m5 will definitely boil. A boiling signal is output in anticipation of this situation, and therefore, the boiling of water in the steel 5 can be detected reliably, although there may be some errors. In this case, the time set in the first timer means 52A is set to such an extent that hot water does not boil over even when the amount of porridge is at its minimum.

In addition, in this embodiment, when reducing the output of the heater 6, the output of the heater 6 is reduced to 50% of the rated value for 6 minutes after the water in the pot 5 boils, and then 2 more
Between 0B and C, the output of heater 6 is reduced to 25 at the rated time.
%, and as a result, the degree of decrease in the output of the heater 6 becomes smaller at the first light of the year when the lagoon boils over with relatively inert light, and the time required to cook the porridge is further shortened. It becomes like this.

Now, in the first embodiment, the time t1 to [
2), the time to reduce the output of the heater 6 to 50% (time 12 to t3), and the time to reduce the output of the heater 6 to 25% (time [3 to [4]) are the rice stored in the steel 5. Although the configuration is such that the above times are constant regardless of the size of (2), it is also possible to have a configuration in which each of the above times is changed depending on the size of the rice hanging, and hereinafter, a second embodiment of the present invention employing such a configuration will be described. An example will be explained with reference to FIGS. 5 to 7. However, in this second embodiment, the same parts as in the first embodiment are designated by the same reference numerals, and the explanation thereof will be omitted.

That is, in FIG. 5, 54 is an eighth memory circuit which stores the first &1 hanging temperature, for example 70°C, as a digital value temperature ITjNS54, and 55 is the second reading temperature, for example 80'G. This is the ninth storage circuit which stores the digital value of hot water temperature l;' S, 5.

56 to 72 are the 10th to 26th memory circuits, and these have 5 minute and 3 minute memory circuits, as shown in FIG.

5 minutes, 4 minutes, 3 minutes, 13 minutes, 10 minutes, 7 minutes, 35 minutes, 3
0 minutes, 25 minutes, 35 seconds, 30 seconds, 25 seconds.

Digital time signals 856 to S72 corresponding to 18 seconds, 15 seconds, and 12 seconds are stored.

73 to 76 are comparison circuits, and other comparison circuits 27 to 33
It has the same configuration as . Reference numerals 77 to 81 denote first to fifth latch circuits, which change the stored contents each time a new signal is input. 82 to 99
are transfer gates, which allow signals to pass while receiving a high-level signal at the gate terminal. 10
0 is a counter, which resets the count value to "0" when a high level signal is received at the reset terminal R, and counts every time the clock pulse Pill from the frequency dividing circuit 18 is received at the L1 terminal CK. and outputs the count value as a numerical signal Sz o o.

A circuit 101 outputs a trigger pulse Ps o t that remains at a high level for a certain period of time when receiving a high level signal. Further, 102 is an AND circuit, 103 is a NOR circuit, 104 is an OR circuit, and 105 and 106 are inverters. In this embodiment, the 12th to 14th storage circuits 58 to 60, the comparison circuits 29. counter 37
．． The first latch circuit 77 and transfer gates 82 to 84 constitute a first timer means 107, each of the 18th to 20th storage circuits 64 to 66, and the comparison circuit 3.
1. Counter 37. Inverter 49. The second latch circuit 79 and transfer gates 88 to 90
A timer means 108 is constructed. In addition, each of the twenty-first to twenty-sixth memory circuits 67 to 72. Comparison circuits 32, 33.
Cycle counter 38. AN0 circuit 45.46. 4th.
Each of the fifth latch circuits 80, 81 . A control means 109 is constituted by the seven transformer gates 91 to 96, and the eighth
Each of the eleventh memory circuits 54 to 57. Comparison circuits 73 to 76, counter 100. A determination means 110 is constituted by the t-transfer gates 97 to 99 and the NOR circuit 103.

Next, the operation of the above structure will be explained with reference to FIGS. 6 and 7, which are similar to FIGS. 3 and 4, respectively.

Now, when rice and the predetermined amount of water required to cook this rice into porridge are stored in w45 and the start switch 7a is turned on in this state, the start pulse P31i is output from the pulse generation circuit 36, and this start Pulse P3ft sets R-S flip 70 tabs 39, 40, and 41, and resets counters 37, 100 and cycle counter 38. At this time, since the temperature detected by the thermistor 8 is 90 degrees Celsius or lower, the temperature signal S19 from the A-D conversion circuit 19 and the temperature signal S20 from the first storage circuit 20 have a relationship of 819<820 and are compared. The circuit 27 begins to output a low level signal, and the output is inverted to a high level signal by the inverter 105 and then applied to one input terminal of the AND circuit 42 via the OR circuit 104. Since the other input terminal of the AND circuit 42 receives a high level signal from the set output terminal Q of the R-87 lip 70 tube 39 set as described above, a high level signal is output from the AND circuit 42. Upon receiving this high level signal, the output circuit 50 turns on the relay contact 11, and in response, the heater 6 is energized and heating of the steel 5 is started. As the heating of the steel 5 progresses, that is, the porridge cooking operation progresses, the detected temperature of the Narmister 8 rises to 70°C, and the temperature signal 819 from the A-D converter circuit 19 and the temperature signal 819 from the eighth memory circuit 54 increase. When the temperature signal Ssa has a relationship of Szs≧854 (
At time t1 in FIGS. 6 and 7, the output of the comparison circuit 73 is inverted to a high level signal. At this time, the temperature signal Si
s and the temperature signal 5ss from the ninth memory circuit 55 (80°C
Since there is a relationship Si2 <Ss s, the comparator circuit 74 also outputs a high level signal, and the high level signals from these comparator circuits 73 and 74 are received by A.
The ND circuit 102 receives the clock pulse P from the frequency dividing circuit 18.
1B is allowed to pass, so that the counter 100 counts up every second.

Thereafter, when the temperature detected by the thermistor 8 rises to 80° C. and the temperature signal 819 and Sss become Sts>Ss (time t2), the output of the comparison circuit 74 is inverted to a low level signal, so the AND circuit 102 now blocks the passage of clock pulse P1[1, and the counter 100
runt-up is stopped by one. At this time, if the count value of the counter 100 is one or more shifts equivalent to 5 minutes at time wholesale 1t2, a numerical signal S1 is sent from the counter 100.
o The time signal 5ss from the tenth storage circuit 56 (
(equivalent to 5 minutes), ill/ and the time signal 5sr (equivalent to 3 minutes) from the eleventh storage circuit 57 are 5soo≧SS6.
>S, 7, so the comparator circuit 75 outputs a high level signal, the comparator circuit 76 outputs a low level signal, and the NOR circuit 103 outputs a low level signal. Also, at time 12, the counter 10
0 count (if the shift exceeds the value equivalent to 3 minutes and is less than the value equivalent to 5 minutes, the above-mentioned number 1iiff signal S 1o
o and time signal Ss 6. S57 is Ss 6 > SI
Since the relationship is OO>5s-r, the comparison circuit 75.76
Both now output low level signals, and NO
R circuit 103 outputs a high level signal. Furthermore, if the count value of the counter 100 is less than the value equivalent to 3 minutes at time t2, the numerical signal Sro a and the temperature signal Ss6/SST have a relationship of S56>S57>=5100, so only the comparison circuit 76 A high level signal is output from the NOR circuit 103, and a low level signal is output from the NOR circuit 103. By the way, the time required for the temperature detected by the thermistor 8 to change from 70°C to 80°C has a property that the longer the amount of rice and water M stored in m5 from the heat capacity part of the steel 5 becomes longer. Yes, 8th
Each of the eleventh memory circuits 54 to 57. Comparison circuits 73 to 76, counter 100. The determination means 110 including the NOR circuit 103 and the like determines the Φ of the rice in the pot 5 using the above property. That is, the determining means 110 determines that if the time required for the temperature detected by the Reamister 8 to change from 70°C to 80°C (time t1 to [2]) is 5 minutes or more, in other words, the temperature inside the steel 5 When the amount of rice is relatively large, the comparison circuit 75
If the time from time 1 to time 12 exceeds 3 minutes and is less than 5 minutes, in other words, the pot 5 When the rice inside the steel has a medium luster, a high level signal is output from only the NOR circuit 103 and is applied to the transfer gate 98, and if the above time is 3 minutes or less, in other words, the rice inside the steel When there are relatively few stitches, a high level signal is output only from the comparator circuit 76 and the transformer 77
Give to gate 99.

However, at time t2, when a low level signal is output from the comparator circuit 74 as described above, the output of A is output from the inverter 1.
Since the signal is inverted to a high level signal by 06 and then applied to the trigger circuit 101, the trigger circuit 101 outputs a trigger pulse pt o l. Then, the trigger pulse Pr.

Transnor gate 97°98 that receives l at the gate terminal
．． 99 will allow the signal to pass for a short period of time.

Therefore, when the amount of rice in the steel 5 is relatively large, a high level signal is output from the transfer gate 97.
The high level signal causes the transfer gate 82,
85, 88.91°94 exhibits a conductive state. As a result, the storage contents of the first to fifth latch circuits 77 to 81 are the time signal 5ss (corresponding to 5 minutes) from the 12th storage circuit 58 and the time signal 861 from the 15th storage circuit 61.
(equivalent to 13 minutes), time signal 364 from the 18th memory circuit 64 (equivalent to 35 minutes), time signal 367 from the 21st memory circuit 67 (equivalent to 35 seconds), time signal 367 from the 24th memory circuit (equivalent to 35 seconds), 70 is rewritten to the time signal Sro (equivalent to 18 seconds).Also, when the rice level in the steel 5 is medium, a high level signal is output from the transformer 71 gate 98 and the transfer gate 83, 86, 89, 9
Since the 13th. 16th, 19th. 22nd. 25th memory circuit 59°62.65,6
Each temperature signal from 8.71 85° (equivalent to 4 minutes), 8G
2 (equivalent to 10 minutes), S65 (equivalent to 30 minutes), 86
day (equivalent to 30 seconds).

571 (equivalent to 15 seconds).

Further, when the rice Φ in m5 is relatively small, a high level signal is output from the transformer 71 gate 99 and the transfer gates 84.87, 90°93.96 are in a conductive state. latch circuits 77 to 8
The memory contents of No. 1 are 14th, 17th, . 20th. 23rd. Each time signal 860 (equivalent to 3 minutes), 863 (equivalent to 7 minutes) from the 26th storage circuit 60.63.66.69.72
.

Ss6 (equivalent to 25 minutes), 569 (equivalent to 25 seconds),
5ro (equivalent to 12 seconds).

Now, for convenience of explanation, in the following, when there is a relatively large number of suspended rice in the steel 5 (i.e., the first to fifth latch circuits 77 to 81 use time signals S, s, S61, S641, respectively),
To explain the case where S6 r + Sy o are stored as an example, when the grueling action further progresses and the temperature detected by the thermistor 8 rises to 90°C (at time j
3), the temperature signal 819 from the A-D conversion circuit 19 and the first
temperature signal 820 from the storage circuit 20 of $19≧82
As a result of this relationship, the output of the comparison circuit 27 is inverted to a high level signal. Then, the trigger pulse P34, which is an auxiliary signal, is output from the circuit 34 and the R-8 flip-flops 40 and 41 are reset.
．． 44 receives a high level signal from each input terminal 0 of the R-S flip-flop 40. 37 and cycle counter 38 start counting up every second.

1. After this time [3, when the time indicated by the time signal Sss stored in the first latch circuit 77, that is, 5 minutes has elapsed [4], the numerical signal 837 from the counter 37 and the above-mentioned time signal Ss Toga 83 y > Ss
Since the relationship is s, the output of the comparison circuit 29 is
Atal reverses to low level Nobui. At time js (time t
4 to 8 minutes), the numerical signal S37 and the time signal S61 or S37≦S
6! Therefore, the comparison circuit 30 outputs a high level signal. Therefore, A that receives the above high level signal
The ND circuit 45 is in a state where it allows the output signal from the comparison circuit 32 to pass, but the comparison circuit 32 receives the numerical signal 838 from the cycle counter 38 (a numerical value that increases sequentially from rOJ to r60J with a cycle of 6.0 seconds). signal) and the fourth
The AND circuit 4 outputs a high level signal only during the period when the time signal 5hr (equivalent to 35 seconds) stored in the latch circuit 80 is in the relationship 838≦Si+t.
The operation of outputting a high level signal for 5 to 35 seconds and then outputting a low level signal for 25 seconds is repeated. Then, the output circuit 50 repeats the operation of turning on the relay contact 11 for 35 seconds and then turning it off for 25 seconds, and as a result, during the period from time t1 to time t5, the heater 6 has a duty ratio of (35/60) The output of heater 6 became energized at 58.3%, and the output of heater 6 decreased to about 58.3%.
．． Reduced to 3%. Then, after time t5, when 13 minutes have passed since time t3#a, the numerical signal 837 from the counter 37 and the time signal 3 from the second latch circuit 77 are passed.
111 is in the relationship 837 > Ss l, the output of the comparison circuit 30 is inverted to a low level signal, and therefore the AN
The D circuit 45 now blocks passage of the output signal from the comparison circuit 32. In the period leading up to time t6, which is another 22 minutes after time t6 (35 minutes have passed since time t3), the numerical signal S3T and the time signal 864 (35 minutes) stored in the seven third latch circuits are used. ) is in the relationship 83□≦Ssa, so the comparator circuit 31
maintains the state in which it outputs a high-level signal. Therefore, the AND circuit 46 continues to allow the output signal from the comparison circuit 33 to pass through, but the comparison circuit 33 receives the numerical signal 83B from the cycle counter 38 and the time signal stored in the fifth latch circuit 81. 870 (equivalent to 18 seconds) or 838≦Sra, a high level signal is output only during a period where the relationship is 838≦Sra, so the AND circuit 46 outputs a high level signal for 18 seconds and then outputs a low level signal for 42 seconds. This action is repeated. Therefore, in this case, the output circuit 50 repeats the operation of turning on the relay contact 11 for 18 seconds and then turning it off for 42 seconds.
As a result, during the period from time t5 to t6, the heater 6 is passed at a duty ratio (1,8/60) x 10Q = 30%, and the output of the heater 6 is reduced to 30% at constant lI8. . Then, when 35 minutes have passed from time t 3 tG [6], the numerical signal S from the counter 37
]r and the time signal 86m stored in the third latch circuit 78
Since S3 t > 86 t, the output of the comparison circuit 31 is inverted to a low level signal, and the AND circuit 46
blocks the output signal from the comparator circuit 33 from passing through. At the same time, the low level signal is inverted by the inverter 49 to a high level signal which is a stop signal, so the three R-S flips 70 are reset, and in response, the output circuit 50 switches the relay contact 11 to A. When the heater 6 is kept in the off state, the power is cut off to the heater 6, and the porridge cooking operation is completed.

In addition, when the distance in wI5 is medium, that is, the 115th gold fifth latch circuits 77 to 81 are timed.
, S621 S6s , and S6s/Sr+ are stored, as can be understood from the above-mentioned action, at time t3 when the temperature detected by the thermistor 8 reaches 90°C.
At time t4, 4 minutes have elapsed since then, a low level signal is output from the comparator circuit 29, and from time t4 to time t5, 6 minutes have elapsed, the output of the heater 6 is at the rated level (30/6
0) x 100 = 50%, and furthermore, the output of the heater 6 is reduced to the rated value (15/60) x 100 = 25 from the time t5 (until 6
%. In addition, when the amount of rice in the steel 5 is relatively small, that is, the first to fifth latch circuits 77 to 81 output the temperature signals 36o *Ss 3 , 866 , 8
+s 91872 respectively memorized,
A low level signal is output from the C comparator circuit 29 at time t4, three minutes after time t3 when the temperature detected by the thermistor 8 reaches 90°C, and at time t, four minutes after this time t4.
5, the output of heater 6 is at the rated value (25/60)
X100# is reduced to 41.7%, and furthermore, from this time [5 to time t6, 18 minutes have passed, the output of the heater 6 is reduced to (12/60)X100=20% of the rated value.
This will be reduced to

In summary, the feature of this embodiment is that after the temperature detected by the thermistor 8 reaches 90°C, the comparison circuit 29 outputs 81i! lI
i! The time it takes to output a low level signal as a signal, the time it takes to output a stop signal from the inverter 49 after outputting the boiling signal to cut off the power to the heater 6 and stop the porridge cooking operation, and the time after outputting the boiling signal. The degree of reduction in the output of the heater 6 is automatically changed depending on the size of the rice porridge cooking area from the rice storage area in the steel 5. That is, when the amount of porridge cooking is relatively large, the time it takes for the inside of the steel 5 to reach a boiling state after the temperature detected by the thermistor 8 reaches 44 degrees or 90 degrees Celsius, and the time required to complete cooking the porridge, respectively. In addition, even after the water in the pot 5 has boiled, a relatively active convection phenomenon is required within the w45. The time it takes for the inside of the pot 5 to reach a boiling state after the detected temperature reaches 90'C and the time it takes to finish cooking the porridge are shortened, and after the water in the steel 5 has boiled (the output of the Uheater 6 is A small but sufficient convection phenomenon
Accordingly, according to the second embodiment described above, it is possible to perform a porridge cooking operation that is practical and has little waste.

In addition, the above 1. In each of the second embodiments, the output of the heater 6 is reduced in two steps, but it may be reduced in only one step.

〔Effect of the invention〕

According to the present invention, as explained above, it is possible to provide a novel rice cooker which has not been available in the past, which automatically prepares and cooks porridge without boiling over water. It is possible to reliably detect the boiling of the water in the steel, which is essential for the above-mentioned automatic porridge cooking operation, so that stable porridge cooking can always be carried out.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a block diagram of the electrical configuration, FIG. 2 is a side view partially cut away, and FIG. Figures and Figures 4 and 4 respectively show the effects.
They are a temperature characteristic curve diagram and an output characteristic curve diagram for one light. Further, FIGS. 5, 6, and 7 are views corresponding to FIGS. 1, 3, and 4, respectively, showing a second embodiment of the present invention. In the figure, 5 is steel, 6 is a heater, 8 is a thermistor (detection means), 10 is a rice cooking control circuit, 51 is a signal output means, 52Δ
, 107 is a first timer means, 528 and 108 are first timer means, 53 and 109 are control means, and 110 is a determination means. No. 1 [21 Bu No. 2 Zukyu 3121 degree

Claims (1)

[Claims] 1. A heater for heating a pot, an adjusting means capable of adjusting the output of the heater, a detecting means for detecting the temperature of the pot, and a temperature detected by the detecting means being a predetermined temperature slightly lower than the boiling point temperature of water. a signal output means for outputting an auxiliary signal when the auxiliary signal is output; a first timer means for outputting the boiling signal when a predetermined time has elapsed after outputting the auxiliary signal; a second timer means for outputting a stop signal to the boiling point; and a second timer means for reducing the output of the heater by the adjusting means when the boiling signal is output, and turning off the heater when the stop signal is output thereafter. A rice cooker characterized by comprising: a control means for controlling the rice cooker.