JPH0443146Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Purpose of the Invention" (Industrial Field of Application) The present invention relates to a rice cooker that controls the amount of heating to be reduced in accordance with the rice cooking capacity after a boiling state is detected.

(Prior Art) Conventionally, this type of rice cooker has a heater drive means for driving a heater for heating a pot, a temperature detection means for detecting the temperature of the pot, and a boiling state determined based on the temperature detected by the temperature detection means. The boiling detection means includes a boiling detection means for detecting boiling, and a control means for controlling on/off of a heater and a heater output, and after the boiling state is detected by the boiling detection means, the control means controls to reduce the amount of heating by the heater. are doing. In this case, the boiling detection means counts the time until the temperature detected by the temperature detection means changes from 70°C to 80°C before boiling, detects the rice cooking capacity based on the time, and detects the rice cooking capacity based on the time. one that detects a boiling state when the detected temperature reaches a constant temperature gradient depending on the rice cooking capacity, or one that detects a boiling state when the detected temperature reaches a certain temperature gradient regardless of the rice cooking capacity; Alternatively, there is a method that detects the boiling state when the rice cooking capacity reaches a predetermined temperature, for example, 102°C. A specific example of the heating amount reduction control will be explained using FIGS. 13 and 14 using porridge cooking as an example. First, the heater is turned on.
The heater is turned on at 100% high output, and when the temperature detected by the temperature detection means that detects the temperature of the pot has reached the boiling state temperature by the boiling detection means (time point P), that is, when the heater is turned on for the first time. When the time W1 has elapsed from 1 to 4 until the boiling state is detected, the heater is turned off for the set time T1 and turned on for the set time _T0 , and after the control set time W2 has elapsed, the heater is energized again. Heating is performed by repeatedly turning the heater on and off for a set time W3 with the rate reduced. In this way, the time W1 from when the heater is turned on for the first time until the point P when the boiling state is detected is a high heat stroke, and from the time when this high heat stroke is finished, the heater is turned off for a set time T1 and the heater is turned off for a set time _T0. The control set time W2 for repeating the ON operation is a medium heat stroke, and the set time W3 from the time when this medium heat stroke ends is a low heat stroke.

By the way, conventionally in this type of rice cooker, the length of the control setting time W2 of the medium heat stroke is set to "large" based on, for example, the time it takes for the detected temperature to change from 70°C to 80°C before the boiling state is detected. It is set according to the rice cooking capacity, which is determined in three stages: , ``medium'', and ``small.''

As mentioned above, before the boiling state is detected, the rice cooking capacity is classified into "large", "medium", and "small", and during the control setting time W2 set according to this classification, the times T ₀ and T1 are set.
If the heater is repeatedly turned on and off to perform a medium heat cycle, no problem will occur if the pot temperature curve A and the water temperature curve B in the pot are the same. Because the temperature is detected by a thermistor that is in contact with the bottom of the pot, and because the water in the pot generates convection while being heated by the heater, there is a difference between the actual water temperature and the temperature at the bottom of the pot detected by the thermistor. Figure 14 and 15th
As shown in the figure, the water temperature curve B has a time delay with respect to the pot temperature curve A, and this time delay increases as the rice cooking capacity increases. Furthermore, even if the rice cooking capacity is the same, the smaller the size of the pot, the greater the time delay. For this reason, when the rice cooking capacity is large as shown in Figure 14, the water temperature does not reach a boiling state during the high heat cycle time W1 and the medium heat cycle time W2, but during the low heat cycle time W3. It will reach boiling point. For this reason, the setting time for the low heat process is to keep the water temperature above 98℃ for 20 minutes, which is necessary for gelatinizing the rice.
Cannot run between W3s. In addition, when the rice cooking capacity is small as shown in Figure 15, the water temperature reaches the boiling state at the point P when the boiling state is detected by the boiling detection means, so the water temperature must be 98°C or higher, which is necessary for gelatinizing the rice. 20
Although it can be continued for several minutes, the heater output after boiling the water is too high and the water in the pot boils over. Furthermore, even if the rice cooking capacity is small, if a foreign object is caught between the pot and the thermistor that detects its temperature, or if the contact between the pot and the thermistor is poor, the thermistor will reach a higher temperature than the pot. When the heater runs out quickly, the rice α
This results in the problem that the conversion is insufficient.

In order to solve this problem, in addition to the temperature detection means that detects the temperature of the pot, a temperature detection means is provided on the lid of the pot to detect the state of steam generation due to boiling water, and the It is possible to control the amount of heating by the heater in the medium heat stroke, but this is
In addition to requiring two temperature detection means, the structure becomes complicated and expensive because the amount of heating by the heater is controlled based on the detection outputs of the two temperature detection means.

(Problem that the invention attempts to solve) In this way, before the boiling state is detected, the rice cooking capacity is classified into "large", "medium", and "small", and for a certain period of time W2 set according to this classification. If the heater is repeatedly turned on and off to perform a medium heat process, it may not be possible to maintain the boiling state necessary for gelatinizing the rice, or the water in the pot may boil over. , As a countermeasure,
In the case where the lid is provided with a temperature detection means for detecting the state of steam generation and the amount of heating by the heater in the medium heat cycle is controlled according to the pot temperature and the state of steam generation, the structure is complicated and expensive. .

Therefore, the present invention is capable of securing the boiling state maintenance time necessary for gelatinizing the rice based on the detected temperature of one temperature detection means, and also prevents the hot water in the pot from boiling over, so that the heating after the boiling state is detected. An object of the present invention is to provide a rice cooker capable of controlling quantity reduction.

[Structure of the invention] (Means for solving the problem) In the present invention, when the heater 5 is turned off after the boiling state is detected, the temperature sensor 4 is not affected by the heat of the heater 5, so the temperature of the pot 3 rapidly changes to the water temperature. This was done with a focus on approaching the drive means 1 of the heater 5.
7, and temperature detection means 10 for detecting the temperature of the pot 3.
and a boiling detection means for detecting a boiling state based on the detection output of the temperature detection means 10, and a control means 11 for reducing the heating amount by the heater 5 after the boiling state is detected by the boiling detection means, Means 11 turns off the heater 5 until a predetermined time period elapses after the boiling state is detected, and turns off the heater 5 after the elapse of the predetermined time based on the detection output of the temperature detection means 10 when the predetermined time period has elapsed.
This is to selectively control the reduction in the amount of heating caused by the heating.

(Function) If the heater 5 is on after the boiling state is detected, the water temperature will have a considerable time delay with respect to the temperature of the pot 3, but if the heater 5 is off after the boiling state is detected, the temperature of the pot 3 will be The water temperature rapidly approaches. Control means 11
By utilizing such a phenomenon, the heater 5 is turned off for a certain period of time after the boiling state is detected, and the amount of heating after the certain period of time is determined based on the detection output of the temperature detection means 10 at the time when the certain period of time has elapsed. perform an action to selectively control the decrease in . Therefore,
The boiling state maintenance time necessary for gelatinizing the rice 7 can be secured, and the hot water in the pot 3 can be prevented from boiling over.

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

Fig. 8 shows the general structure of the rice cooker, 1 is the main body of the rice cooker, 2 is the lid, 3 is a pot serving as a container, and 4 is a container that comes into contact with the bottom of the pot 3 when the pot 3 is accommodated in the main body 1. 5 is a heater as a heating means disposed below the pot 3; 6 is a food to be cooked, which is made of rice 7 and water 8;

FIG. 6 is a block diagram showing the electrical configuration.
In the same figure, 9 is an A/D converter which together with the temperature sensor 4 constitutes a temperature detection means 10, which detects the temperature of the pot 3 by the temperature detection means 10, and determines the temperature according to the detected temperature tk. Outputs a detection signal.
11 is a control means consisting of a microcomputer, which, as is well known, has a CPU 12, a clock circuit 13, a memory 14, an input circuit 15, and an output circuit 16.
etc. This control means 11 performs driving control of the heater 5 according to a control program it owns, and controls the heater 5 for a certain period of time after detecting the boiling state and the boiling state, which will be described later, based on the detected temperature from the temperature detecting means 10. The temperature when the heater 5 is turned off is detected, and based on these detection results and the detected temperature tk, the heater 5 is turned on and off and its output is controlled to perform a high heat stroke, a medium heat stroke, a low heat stroke, etc. Reference numeral 17 denotes a drive circuit for the heater 5, which turns on and off the heater 5 and adjusts its output based on a heater on signal, a heater off signal, and an output adjustment signal given from the control means 11.

Next, the control of each stroke will be explained with reference to FIGS. 1 to 5. When the rice cooking start switch (not shown) is turned on, the output of the heater 5 is set to high output (100% output), and the rice cooking process is executed with this output, and when the rice cooking process is finished, the rice cooking process starts. Transition. In this rice cooking process, the output of the heater 5 is maintained at high output H to maintain the ON state, thereby heating the pot 3 and the contents (rice 7 and water 8) inside the pot 3. And pot 3
inside (especially the bottom of pot 3) is at boiling temperature (in this case
100° C.), the control means 11 detects the boiling state. The detected temperature at this time is defined as the boiling temperature tl. By detecting this boiling state, the high heat cycle time is determined.
Transitioning from W1 to medium heat stroke time W2, a reduction control of the amount of heating by the heater 5 during the rice cooking stage is executed.

The heating amount reduction control in the case of FIG. 1 will be explained with reference also to the flowchart of FIG. 7. When this medium heat process starts, first step S1
Time count (parameter Tx) as shown in
At the same time, a time count (parameter Ty) is started as shown in step S2, and the heater 5 is turned off as shown in step S3.
Then, as shown in step S4, the count time Ty
In other words, it is determined whether or not the heater off time has passed the set time T1, and if the heater off time has not passed the set time T1, the routine moves to "NO" in step S4, and the count is started as shown in step S5. It is determined whether the time Tx, that is, the time of the medium heat stroke by the heater 5 has passed the control set time W2, and in this example, since it has not elapsed, the process returns to step S4 according to "NO" in step S5. Then, when the heater off time has passed the set time T1, according to "YES" in step S4, as shown in step S6, whether the detected temperature tk of the temperature detection means 10 at the time point P1 when the set time T1 has elapsed is below the boiling state detection temperature tl? A judgment is made as to whether or not. 1st
In the example shown in the figure, since tk<tl, in response to "YES" in step S6, the parameter Ty is cleared and the time count (parameter Ty) is restarted as shown in step S7. Next, the heater 5 is turned on as shown in step S8. Next step
As shown in S9, it is determined whether or not the count time Ty, that is, the heater on time has passed the set time _T0 , and if the heater on time has not passed the set time _T0 , the routine follows "NO" in step S9. Then, as shown in step S10, it is determined whether the count time Tx, that is, the time of the medium heat stroke by the heater 5, is less than or equal to the control set time W2.
In this example, as shown in step S11, it is determined whether or not the detected temperature tk of the temperature detection means 10 at P2 during the set time _T0 is equal to or higher than the boiling state detection temperature tl. Since tk<tl, the process returns to step S9 and it is determined whether or not the heater-on time has exceeded the set time _T0 .
Once the time has elapsed, the process returns to step S2 in the same manner as described above. Then, in the same way as above, steps S2 to S4 are performed.
After the heater off time has passed the set time T1, as shown in step S6, it is determined whether the detected temperature tk of the temperature detection means 10 at the time point P3 when the set time T1 has elapsed is below the boiling state detection temperature tl. Ru. In the example shown in Figure 1, since tk > tl, the heater off state is maintained, and according to "NO" in step S6, the process moves to step S12 and the parameter
Along with clearing Ty, the time count (parameter Ty) is restarted, and then, as shown in step S13, it is determined whether the count time Ty, that is, the heater off time after the set time T1 has elapsed, has reached the set time T2. , Heater off time is set time
If T2 has not been reached, as shown in step S14, it is determined whether or not the count time Tx, that is, the time of the medium heat stroke, has passed the control set time W2.
The routine returns to step S13, and when the heater off time has elapsed for the set time T2, step S15
As shown, it is determined whether or not the temperature tk detected by the temperature detection means 10 at the time point P4 when the set time T2 is reached is equal to or lower than the boiling state detection temperature tl. In this example, tk<tl, so select "YES" in step S15.
The routine returns to step S7, and the heater is turned on through steps S7 to S11 in the same manner as above, and the detected temperature is set at P5 during the set time _T0 .
It is determined whether tk is higher than the boiling state detection temperature tl, and since tk > tl, after the heater is on for the set time _T0 , the process returns to step S2 and the heater is turned off, and the steps are repeated in the same way as above.
When the set time T1 is reached after the heater is turned off for the set time T1 through steps S2 to S6.
It is determined whether the temperature tk detected by the temperature detection means 10 at P6 is lower than the boiling state detection temperature tl. In this example, since tk > tl, the set time T2 is passed through steps S12 to S15 in the same way as above.
It is determined whether the detected temperature tk at time P7 after passing through the heater off state is below the boiling state detection temperature tl, and in this example, since tk > tl, the routine moves to step S15 of "NO", The medium heat stroke ends at time W2′ and shifts to the low heat stroke for the set time W3.

Next, the heating amount reduction control in the case of FIG. 2 will be explained with reference to the flowchart of FIG. 7. In the example of Fig. 2, step S1 is performed as in Fig. 1.
After passing through step S9, the heater is turned off for a set time T1, and then the heater is turned on for a set time _T0 , and then the process returns to step S2. Next, after going through steps S2 to S4 and being in the heater off state for a set time T1, as shown in step S6, when the heater off state reaches the set time T1, it is determined whether the detected temperature tk at P3 is lower than the boiling state detection temperature tl. In this example, since tk<tl, the heater is turned on through steps S7 and S8, and the detected temperature tk is set at P4 while the heater is on for a set time _T0 through steps S9 to S11. In this example, tk≧ is determined at P4' when time _T00 has elapsed after the heater-off state for set time T1 ended at P4 during set time _T0 . tl, so after the time _T00 has elapsed, the routine moves to step S11 and returns to step S2. Then step S2
Or, since the control set time W2 does not elapse after the heater is turned off for the set time T1 through step S5, the detected temperature tk at P5 is lower than the boiling detection temperature tl at the time when the heater is turned off for the set time T1, as shown in step S6. A judgment is made as to whether or not
In this example, tk > tl, so "NO" in step S6
Steps S12 to S14 are followed, and the heater is turned off for a set time T2.
Then, as shown in step S15, it is determined whether or not the detected temperature tk at P6 is lower than the boiling detection temperature tl after the heater has been turned off for the set time T2. In this example, if tk > tl, Since there is, the routine moves to step S15 (NO), the medium heat stroke is completed in a shorter time W2' than in the case of FIG. 1, and the transition is made to the low heat stroke for the set time W3.

Next, the heating amount reduction control in the case of FIG. 3 will be explained with reference to the flowchart of FIG. 7. In this example, the steps are the same as in Figure 1.
After the heater is turned off for a set time T1 through steps S2 and S4, as shown in step S6, it is determined whether the detected temperature tk at P1 is lower than the boiling detection temperature tl when the heater is turned off for the set time T1. In this example, since tk > tl, the routine moves to step S6 "NO", and the step
The heater-off state continues for the set time T2 through steps S12 to S14, and then, as shown in step S15, the time point P2 when the set time T2 of the heater-off state has elapsed.
It is determined whether or not the detected temperature tk of the boiling point is lower than the boiling detection temperature tl. In this example, since tk<tl, the process moves to the "YES" routine of step S15, returns to step S7, and then steps S7 to S7. step
After S11, the heater remains on for the set time _T0 , and during the set time _T0 , a determination is made at P3 whether or not the detected temperature tk becomes equal to or higher than the boiling detection temperature tl, and time _T00 has elapsed since the heater was turned on. When P3′
Since tk≧tl, after time _T00 has elapsed, the process moves to the "YES" routine of step S11 and returns to step S2. Next, through steps S2 to S15, it is determined that the detected temperature tk at P4 is tk > tl after the off state for the set time T1 has elapsed, and the set time T2 is determined.
After the off state for the set time T2 has elapsed, the detected temperature tk at P5 is tk > tl, so the process moves to the "NO" routine in step S15, and the medium heat stroke is changed from the case in Fig. 2. The process ends after a short time W2′ and moves to a low heat process for a set time W3.

Next, the heating amount reduction control in the case of FIG. 4 will be explained with reference to the flowchart of FIG. 7. In this example, after the heater is turned on for a set time T1 through steps S2 to S6, since the detected temperature tk at the elapsed time point P1 is tk<tl, the heater is turned on through steps S7 to S11 and the set time _T0 is reached. While the heater is on, it is determined whether the detected temperature tk at that point P2 becomes tk≧tl, and since tk≧tl is not satisfied, the process returns to step S2 after the heater is on for a set time _T0 , and the process returns to step S2. Step S11 is repeated, and since the detected temperature tk never exceeds the boiling detection temperature tl, when the count time Tx reaches the control setting time W2 in step S5 or step S10, the answer is "YES" in step S5 or "YES" in step S10 at P8. NO'' routine, the medium heat stroke ends at a preset control setting time W2, and the process moves to a low heat stroke for a set time W3.

Next, the heating amount reduction control in the case of FIG. 5 will be explained with reference to the flowchart of FIG. 7. In this example, after the heater is turned off for a set time T1 through steps S2 to S6, since the detected temperature tk at the elapsed time point P1 is tk>tl, the heater is turned off for a set time T2 through steps S12 to S14. , Heater off state setting time
After T2 has elapsed, the set time is set as shown in step S15.
It is determined whether the detected temperature tk at the time point P2 after T2 is lower than the boiling detection temperature tl, and since tk > tl, the routine moves to follow "NO" in step S15, and the medium heat process is performed according to Fig. 3. The process ends after a short time W2', and then moves to the low heat process for a set time W3.

In this way, Figure 1 shows that after the heater is turned on twice for the set time T ₀ after the heater is turned off,
After the heater is turned on for the set times T1 and T2, it shifts to the low heat process before the control set time W2 is reached.
Figure 2 shows that after repeating the heater on state for a set time T ₀ and a set time T ₀₀ after the heater is turned off,
As in Fig. 1, the process shifts to low heat before the control set time W2 is reached, and in Fig. 3, it is performed after the heater is turned off.After the heater is turned on for the set time T ₀₀ , the heater is turned off and then as in Fig. 1. Control setting time
It shifts to the low heat stage before it reaches W2, and shifts to the low heat stage faster from Figure 1 to Figure 3. Figure 4 shows the setting time during control setting time W2.
The heater-off state at T1 and the heater-on state at the set time _T0 are repeated, and after the control setting time W2, the process moves to a low heat process. In Fig. 5, after the heater off operation for the set times T1 and T2 has elapsed, the process immediately shifts to the low heat process without turning on the heater. are doing. In addition, the setting time for the heater off operation is divided into two stages, T1 and T2, because when the temperature drop gradient of the pot temperature curve A is large, the heater is turned on earlier, and the detected temperature tk of the pot temperature curve A is higher than the boiling detection temperature tl. Sometimes, the heater off time is lengthened to see the temperature change in pot temperature curve A. This results in a large amount of heating at the maximum rice cooking capacity, a small amount of heating at the minimum rice cooking capacity, and a linear heating amount at the intermediate cooking capacity. do. In addition, the setting time T1 of the heater off state,
T2 is set arbitrarily, and control setting time W2 is determined and set experimentally. The reason why the set time T ₀ for the heater-on state is made constant is to prevent as much as possible the difference in temperature change between the pan temperature curve A and the water temperature curve B that occurs during heating, and to prevent abnormal heating.

Next, with reference to FIGS. 9 and 10, the phenomenon used to control the reduction in heating amount shown in the above embodiment, that is, when the heater 5 is turned off after boiling is detected, the temperature sensor 4
The reason why the temperature of the pot 3 rapidly approaches the water temperature will be explained because it is not affected by the heat of the heater 5.
In the example of Fig. 9, when the heater is turned off at the time P when the pot temperature curve A reaches the boiling detection temperature tl, the pot temperature curve A steeply descends to the water temperature curve since the water temperature curve B is before boiling. You can get closer to B. In addition,
This example shows the maximum rice cooking capacity state when the rice cooking capacity is larger than the heating capacity of the pot 3, or the case where the contact between the temperature sensor 4 and the pot 3 is poor and the heater is cut off prematurely. In addition, in the example of Fig. 10, the point P when the pot temperature curve A reaches the boiling detection temperature tl
When the heater is turned off, the water temperature curve B is also in the boiling state, so the pot temperature curve A gradually decreases, and the relationship between the detected temperature tk and the detected boiling temperature tl becomes tk≧tl. Note that this example represents the minimum rice cooking capacity state when the rice cooking capacity is the same or smaller than the heating capacity of the pot 3. It is also possible that the pot temperature curve A is lower than the water temperature curve B during heating, but as mentioned above, the temperature of the pot 3 is detected by a thermistor that is in contact with the bottom of the pot 3, and the temperature inside the pot 3 is The convection of the water 8 and the heating by the heater 5 first heat the pot 3 itself, and because the water 8 is heated by heat conduction from the pot 3, the pot temperature curve A is actually lower than the water temperature curve B. There is no condition. Further, since the specific heat of boiled water 8 is approximately half that of non-boiled water 8, the water temperature does not easily drop once the water temperature curve B reaches the boiling temperature tl.

When looking at the examples shown in FIGS. 2 and 3 with attention to such a phenomenon, the change in the pot temperature curve A shown in FIGS. 2 and 3 is the maximum rice cooking capacity state shown in FIG. The state is intermediate between the minimum rice cooking capacity shown in the figure, and the rice cooking capacity is an intermediate cooking capacity with respect to the heating capacity of pot 3, and even in such an intermediate cooking capacity, settings are made as shown in Figures 2 and 3. Time T1,
Fine heating adjustment can be made according to the rice cooking capacity by the heater off state at T2, the heater on state at the set time _T0 , and the heater on state at the time _T00 , and a control time W2' suitable for the rice cooking capacity can be obtained. In addition, linear heating adjustment is possible from the minimum rice cooking capacity to the maximum rice cooking capacity. In this case, the rice cooking capacity is, for example, 1
If the minimum rice cooking capacity is 2 to 2 cups and the maximum rice cooking capacity is 7 to 10 cups, the amount of heating required for the same rice cooking capacity will vary depending on water temperature, rice quality, water amount, etc. For example, even if the rice cooking capacity is 2 cups, when the water temperature is low or high, or the water content of rice 7,
When the water absorption rate is low, a larger amount of heating is required than when this is not the case, so even a rice cooking capacity of 2 cups can be regarded as an intermediate cooking capacity.

Fig. 11 shows the water temperature curve B in the maximum rice cooking capacity state or the heater prematurely cut-off state shown in Fig. 4, together with the pot temperature curve A, and shows the heater off state at set time T1 and the heater on state at set time _T0 . and the experimentally determined control setting time W2
After repeating for a while, move on to the low heat process for the set time W3. In this case, the water temperature curve B is the control setting time W2
Since the boiling state is reached in between, the boiling state maintenance time necessary for gelatinizing the rice 7 can be secured. In addition, Fig. 12 shows the water temperature curve B in the minimum rice cooking capacity state shown in Fig. 5 together with the pot temperature curve A, and immediately after the heater is turned off for set times T1 and T2, the low heat cycle for set time W3 is started. Transition.
In this case, in the water temperature curve B, the water 8 is boiling at the boiling detection point P, so the heater is not turned on. Therefore, the hot water in the pot 3 will not boil over. In addition, even in the range of intermediate rice cooking capacity from the maximum rice cooking capacity state shown in Fig. 11 or the heater prematurely cut-off state to the minimum rice cooking capacity state shown in Fig. 12, the rice cooking capacity varies as shown in Figs. 1 to 3. Since fine heating adjustment is possible, it is possible to prevent the boiling state maintenance time required for gelatinization of the rice 7 from being secured or the hot water in the pot 3 from boiling over. Figure 13 shows the water temperature curve B in the rice porridge cooking state together with the pot temperature curve A. The water temperature curve B reaches the boiling state during the time W2' of the medium heat process, and then the water temperature curve B reaches the boiling state during the time W2' of the medium heat process. The boiling state maintenance time W3 required for αization can be secured for, for example, 20 minutes, and then the uneven process with the heater off is performed for about 5 minutes.

Unlike conventional methods, rice cooking is detected in three stages: "large", "medium", and "small" based on the time it takes for the temperature detected by the temperature detection means to change from 70°C to 80°C before boiling is detected. If the control setting time W2 is set in advance according to the capacity, it is not possible to finely heat the rice in the range of rice cooking capacity from large to small, and if there is an error in the amount of cooked rice detected before boiling However, in the above-mentioned embodiment of the present invention, the heater 5 adjusts the heating temperature based on the detected temperature tk after the heater is off or the detected temperature when the heater is on at the set time T1 or the set time T2 after boiling detection. Since the heating amount is finely controlled and the control time W2' is finely selected, it is possible to accurately control the heating amount reduction according to the rice cooking capacity.
Sufficient time for maintaining the boiling state necessary for gelatinizing the rice 7 can be ensured, and boiling over of hot water in the pot 3 can be well prevented. Further, since there is no need to provide another temperature detection means on the lid 2 of the pot 3, the above effects can be obtained based on the temperature detected by one temperature detection means 10, which is favorable in terms of cost.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, although the above embodiment has been explained using porridge cooking as an example, it can also be applied to white rice, brown rice, takikomi, rice porridge cooking, etc. Furthermore, although each function such as the control means and the boiling detection means is provided by the control means comprising a microcomputer, each function may be obtained by an individual electronic circuit.

[Effects of the invention] The present invention turns off the heater for a certain period of time after the boiling state is detected, and then adjusts the heating amount by the heater after the certain period of time based on the detected temperature after the certain period of time has elapsed. Since we have performed an operation to selectively reduce the
Heating can be adjusted accurately according to the rice cooking capacity based on the temperature detected by one temperature detection means, the boiling state can be maintained for the time necessary for gelatinizing the rice, and the hot water in the pot can be prevented from boiling over. We can provide a rice cooker.

[Brief explanation of the drawing]

1 to 5 are graphs showing the relationship between the pot temperature curve and the on/off state of the heater according to an embodiment of the present invention, and FIG. 6 is a block diagram of the electrical configuration showing an embodiment of the present invention. Figure 7 is a flowchart, Figure 8
The figure is a sectional view showing the schematic structure of a rice cooker, Figures 9 and 10 are graphs for explaining the principle of the invention, and Figures 11, 12, and 13 are pots showing embodiments of the invention. Graphs showing the relationship between temperature curves and water temperature curves, FIGS. 14 and 15 are graphs showing conventional examples. 5... Heater, 10... Temperature detection means, 11...
...control means (boiling detection means), 17... drive means.

Claims (1)

[Scope of utility model registration request] A heater driving means, a temperature detecting means for detecting the temperature of the pot, a boiling detecting means for detecting a boiling state based on the detection output of the temperature detecting means, and a certain period of time elapses after boiling is detected by the boiling detecting means. control for performing an operation of turning off the heater for a period of time and selectively controlling a reduction in the amount of heating by the heater after the predetermined time has elapsed based on a detection output by the temperature detection means when the predetermined time has elapsed; A rice cooker characterized by comprising means.