JPS61222419A - 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] (Industrial application field) The present invention relates to a cooking device such as a jar rice cooker.

(Prior art and its problems) Conventionally, in jar rice cookers, etc., a heat-retaining heater is provided on the main body side and the lid side, and both of the heat-retaining heaters are controlled based on a single sensor provided on the side of the main body. However, the sensor installed on the side of the main unit has poor response to temperature changes of the food to be cooked, i.e., rice, and cannot accurately detect the temperature change.Also, condensation tends to occur on the inner surface of the inner lid, making it difficult to maintain good heat retention. Things were becoming difficult.

(Object of the Invention) The present invention has been made in view of the above points, and is capable of controlling the heat-retaining heater on the main body side by quickly responding to temperature changes of the food to be cooked and accurately capturing the temperature changes. To provide a cooking appliance which eliminates dew condensation on the inner surface of an inner lid by keeping the atmospheric temperature inside the pot slightly higher than the temperature of the food to be cooked, and which makes it possible to obtain a good heat retention state as a whole.

(Structure of the Invention) The present invention includes an inner pot that houses food to be cooked, a main body that houses the inner pot, an inner lid that closes an opening of the inner pot, and an outer lid that covers the outside of the inner lid. , a heat-retaining heater installed on the main body side,
a first sensor that detects a change in temperature at the bottom of the inner pot, a heat retaining heater provided on the outer lid side, a second sensor that detects a change in atmospheric temperature within the inner pot, and a The heat retention control means controls the heat retention heater on the main body side based on the signal and the heat retention heater on the outer lid side based on the signal from the second sensor, and controls the heat retention set temperature by the second sensor. The temperature is set slightly higher than the temperature set by the sensor No. 1 to achieve the desired purpose.

(Example) Examples of the present invention shown in the drawings will be described in detail below.

First, FIG. 1 shows the schematic structure of the rice cooker of the present invention.

In the figure, 1 is the insulated main body of the jar rice cooker, 2 is the outer pot, and 3 is the rice cooker heater (700W) installed at the inner bottom of the outer pot 2.
, 4 is an inner pot that can be moved in and out of the outer pot 2 and accommodates the food to be cooked;
5 is a heat-retaining heater provided on the outer surface of the outer pot 2; 6 is a first sensor such as a thermistor that is in contact with the outer bottom surface of the inner pot 4 to detect temperature changes at the bottom; 7 is an outer lid having a heat-insulating structure; 8 is a Outer lid 7
9 is a hollow hanging rod protruding from the center of the inner surface of the outer lid 7; 10 is an inner heater that is removably inserted and supported on the hanging rod 9 through a seal packing 11; Lid, 12
14 is a steam cylinder with a built-in ball valve 13 protruding from the inner lid 10;
is a second sensor such as a thermistor enclosed in the hanging rod 9, and this sensor 14 is connected to the inner pot 4 via the hanging rod 9.
Detects changes in the ambient temperature inside the device. Note that the hanging rod 9 is made of a metal with good thermal conductivity, such as aluminum.

Next, FIG. 2 is a diagram showing the operating section. 15 is a time display section, 16 is a menu select button, 17 is an hour set key, 18 is a minute set key, 19 is a start key, 20
21 is a cancel key, 21 is a warming start key, a- is a display LED, and the display LEDa displays the timer operation. Display LED b = g indicates preheating, rice cooking (primary), rice cooking (
2nd), rice cooking (3rd), 2nd time cooking, uneven cooking, and keeping warm.In addition, the display LED h- shows white rice, brown rice,
Cooks the rice and displays the porridge menu. Further, the operation section is marked with a notification timing depending on the positional relationship with the display LEDs b to g.

FIG. 3 is a block diagram of the entire control circuit. In FIG. 3, 22 is a microcomputer, which mainly includes a central processing unit (hereinafter referred to as CPU) 23 and an electronic timer 24.
, a read-only memory (hereinafter referred to as ROM) 25, an arbitrary access memory (hereinafter referred to as RAM) 26, and an interface (input/output signal processing circuit) 27. The ROM 25 stores a control program for the CPU 23, and the RAM 26 is used as a data memory for the CPU 28. The CPU 2g reads the status of each part on the input side via the interface 27 and also reads the control program in the ROM 25 to perform preheating, rice cooking (primary) (secondary) (tertiary),
It determines processes such as boiling, uneven cooking, and keeping warm, and controls the heating unit etc. necessary to execute the process via the interface 27, and the process transition is performed in cooperation with the electronic timer 24. It will be done. In addition, the electronic timer 24 is
3, it counts up or down the time and outputs a signal.

In the above configuration, the control will be explained in detail below. In addition, Fig. 4 is a diagram showing a model of the temporal change in the temperature detected by the first and second sensors, and Fig. 5 is a diagram showing the relationship between the temperature detected by the sensor and the rice cooking power as the capacity changes. .

First, after turning on the power, press menu select button 1.
6 to select the desired menu. In accordance with this selection, a predetermined display LED is turned on and a menu is displayed.

white rice cooked rice Now, the case where cooked white rice is selected will be explained.

First, after selecting the menu, when the start key 19 is turned on, the CPU 23 confirms that the start key 19 is turned on, and
Next, it is determined which flag is specified. Since white rice cooking is currently selected, the designation of flag 1 is determined and the control program in the ROM 25 corresponding to flag 1 is read out to perform control as shown in the flowchart shown in FIG. In addition, turn on the start key 19.
In response to this, the notification section (for example, a piezoelectric buzzer) operates and emits a confirmation sound.

O Preheating step In this preheating step, the food to be cooked (rice and water) is heated to a certain constant temperature, and the humidity is maintained until a certain period of time has elapsed from the start of rice cooking (preheating). In addition, in Fig. 6, D
The frame indicated by indicates a flowchart of the preheating process.

When the preheating process starts, the rice cooking heater 3 is turned on and heats the object to be heated, and the heating is continued until the temperature detected by the first sensor 6 reaches a certain temperature (for example, 62° C.). When the detected temperature reaches 62°C, the rice cooking heater 3 is turned off. Thereafter, by turning on and off the rice cooking heater 3 based on the temperature detected by the first sensor 6, the temperature is maintained at 62°C until a certain period of time (for example, 10 minutes) has elapsed from the start of preheating, and when 10 minutes have passed, Move on to the next stage of rice cooking (first stage) process.

The purpose of this process is to promote water absorption in the rice, to correct the temperature of the food to be cooked relative to the initial water temperature and air temperature, and to make the temperature distribution uniform regardless of the amount of rice cooked. and time are just examples, and may be arbitrarily set to values necessary to achieve the intended purpose.

In the preheating process, the temperature detected by the second sensor 14 is lower than the temperature detected by the first sensor 6, as shown in FIG. 4, and the rising curve is extremely gradual.

Q Rice Cooking (Primary) Process In this process, capacity determination data is collected, the amount of rice to be cooked is determined based on this data, and the heating duty of the next stage is determined. In FIG. 6, the frame indicated by E shows a flowchart of the process.

Now, when moving to the rice cooking (first stage) process, turn the rice cooker heater 3 to O.
Nt, the food to be cooked is heated and heated continuously until the temperature detected by the first sensor 6 reaches a predetermined temperature (for example, 88°C) from 62°C, while counting up the time from the start of the rice cooking process. go.

When it is determined that the temperature detected by the first sensor 6 has reached 88° C., the timer data T at this time is read and stored as data T1.

Next, the amount of cooked rice is determined based on this timer data T1,
Determine the heating duty for the next rice cooking (secondary) process.

Here, the determination of the amount of cooked rice will be explained. The amount of rice cooked is in 10 stages from 1 go (o, zl) to 10 go (1,8 l depending on the time width of
The heating duty is divided into O stages, and the heating duty is set for each rice cooking amount as described later, and the programmed contents are stored in the ROM 26 in advance. For example, if the rice cooking heater 3 is 700W, the timer data T1 is 50W.
When it is longer than 0 seconds, it is judged as 10 cups, and when it is less than 150 seconds, it is judged as 1 cup, and the period from 500 seconds to 150 seconds is divided according to the time width specific to each amount of rice cooked. Thus, the amount of cooked rice is determined by sequentially subtracting the time width for each amount of cooked rice from the timer data T1, and determines the amount of cooked rice when the relationship T1<0 is reached.

Next, the heating duty is set corresponding to each amount of rice to be cooked, and is used to adjust the time during which the rice cooking heater 3 is energized within a certain period (for example, 64 seconds). The purpose of this heating duty is to keep fluctuations in the execution time of the rice cooking (secondary) process due to the amount of rice cooked to a minimum. For example, for 10 cups, No. 64 64 seconds, for 1 cup, 32 seconds/rice cooking heater 3 During this period, the heating duty is set according to the amount of rice to be cooked. Therefore, the heating power in the rice cooking (secondary) step is 700 W for 10 cups and 350 W for 1 cup.

In addition, in the rice cooking (primary) process, the temperature detected by the second sensor 14 is low as shown in FIG. 4, and the rising curve is also gradual. The end temperature of the rice cooking (primary) step and the cycle of duty control are not limited to the above values.

○ After the rice cooking amount is determined and the heating duty is determined in the first step of the rice cooking (secondary) process, when the rice cooking (secondary) process is started, the rice cooking heater 3 is controlled in duty according to the above determination. While heating the food, the time is counted up following the previous step, and by determining whether the food has boiled, the process moves to the next rice cooking (tertiary) step.

In FIG. 6, the frame indicated by F shows a flowchart of the process.

Here, determination of boiling of the food to be cooked will be explained.

As shown in FIG. 4, the temperature detected by the first sensor 6 reaches 100°C in a short time from the start of the rice cooking (secondary) process, but this is due to the temperature at the bottom of the food near the rice cooking heater 3. This is due to partial boiling and the thermal influence of the rice cooking heater 3, and at this point the entire food to be cooked has not yet reached a boiling state, so if boiling is determined based on the temperature detected by the first sensor 6, it will not be accurate. It lacks sex. On the other hand, the temperature detected by the second sensor 14 gradually rises even after the start of the rice cooking (secondary) process, and the entire food to be cooked begins to boil and a lot of steam is generated, causing steam to flow inside the inner pot 4. When it starts to fill up, it rises rapidly.

Therefore, by detecting a sudden rise in the temperature detected by the second sensor 14, it is possible to accurately determine whether the entire food to be cooked has boiled.

However, when the temperature detected by the second sensor 14 suddenly rises, it is sensed that the temperature has reached a certain temperature (for example, 90° C.), and boiling is determined.

Therefore, the rice cooking (secondary) process ends when it is determined that the temperature detected by the second sensor 14 has reached 90°C, and the rice cooking (third) process starts. Data T, i.e. from the start of the rice cooking (1st stage) process to the rice cooking (2nd stage)
The elapsed time until the end of the process is read and stored as data T2. Next, based on this timer data T2, the amount of rice to be cooked is determined in the same way as in the previous case, and the heating duty of the next stage is determined.
Determine.

The amount of rice cooked is divided into 10 stages as in the previous case. For example, when the timer data T2 is 750 seconds or more, it is 10 cups, and when it is 350 seconds or less, it is 1 cup, and in between is a time width specific to each rice cooking amount. It is divided by. Also, heating duty
In order to completely gelatinize the rice, the rice cooking (tertiary) process should be cooked twice and the time for the shading process should be at least 20 minutes, there should be no boiling over, and the rice cooking (first) should be over 20 minutes. The time from the start of the process to the end of the rice cooking (tertiary) process is set for each amount of rice, with the condition that the time is approximately constant regardless of the amount of rice cooked.For example, for 10 cups, the heating voltage is set for 64 seconds. Set the cuff to 00W (/64 seconds rice cooking heater 16 seconds ON), and for 1 cup, set the heating power to 175W (/64 seconds rice cooking heater N).

Rice Cooking (Tertiary) Process In this process, the rice to be cooked, that is, white rice, is cooked by duty-controlling the rice cooking heater 3 based on the above determination.

In FIG. 6, the frame indicated by G shows a flowchart of the process.

That is, heating progresses through the duty control of the rice cooking heater 3, the moisture in the inner pot 4 disappears, the bottom humidity rises rapidly, and the temperature detected by the first sensor 6 reaches the finished cooking temperature (for example, 124°C). When it is determined that the rice cooking process has been completed, the rice cooking heater 3 is turned off and the process moves to the next twice-cooking/mixing process.

In addition, since the heating duty in the rice cooking (tertiary) process is set based on the conditions mentioned above, the cooking time is almost the same regardless of the amount of rice cooked, as shown in Figure 6. Become. Also, the notification section is activated when the rice is cooked.

02-degree cooking/uniform process This process finishes the rice by draining and browning the cooked rice, and by completing this process, sufficient unevenness is achieved and the rice is ready to eat.

In FIG. 6, the frame indicated by H shows a flowchart of the process.

When moving to the double-cooking/uniforming step, a countdown for a certain period of time (for example, 12 minutes) is started, while waiting for the temperature detected by the first sensor 6 to drop to a predetermined temperature (for example, 110°C), and then the temperature is increased to 110°C. When it is determined that the temperature has reached 124°C, the rice cooking heater 3 is turned ON'L and heated again until the temperature reaches 124°C, and when the temperature reaches 124°C, the rice cooking heater 3 is turned OFF and thereafter kept in a stopped state. Then, after 12 minutes have elapsed, the completion of the rice is notified and the process moves on to the warming process.

○ Heat retention process When moving to the heat retention process, as shown by the frame I in Figure 6,
The first sensor 6 and the second sensor 247) control the heat-retaining heaters 5 and 8 according to the temperature detected by the sensor t-14 to keep the rice at the temperature.

That is, the first sensor 6 quickly responds to the temperature change of the rice at the bottom of the inner pot 4 and accurately captures the temperature change, and when the detected temperature drops to, for example, 73° C. or lower,
When the temperature exceeds 73°C, the temperature-retaining heater 5 is turned off. On the other hand, the second sensor 14 accurately captures the atmospheric temperature inside the inner pot 4, and when the detected temperature drops to, for example, 76°C or lower, the heat retaining heater 8 is turned on and the temperature reaches 76°C.
When the temperature exceeds this temperature, the warming heater 8 is turned off, and the above-described operation is repeated to keep the rice warm in a good condition.

The reason why the temperature set by the second sensor 14 is higher than the temperature set by the first sensor 6 is that the inner lid 10
This is to prevent dew from forming on the inner surface of the Furthermore, the reason why both the sensors 6 and 14 are used to individually control the heat retaining heaters 5 and 8 is that the first sensor 6 alone cannot quickly detect the temperature drop in the upper part due to the opening of the lid, and the second sensor This is because the temperature change of the food to be cooked, that is, the rice, cannot be accurately detected with only 14.

As described above, white rice is cooked.
Next, I will explain brown rice cooking.

When brown rice cooking is selected using the brown rice cooking menu selection button 16 and the start key 19 is turned on, the designation of flag 2 is determined and the corresponding control program is read out, thereby controlling as shown in the flowchart shown in Figure 7. .

In FIG. 7, the parts common to those in FIG. 6 are designated by the reference numerals in the frame in FIG. 6, and the details are omitted.

The control of this brown rice cooking is basically the same as that of white rice cooking, and only the different points will be explained below.

In the preheating process for cooking brown rice, the execution time is set longer than that for cooking white rice, so that even brown rice, which has poor water absorption compared to white rice, can absorb sufficient water. - As an example, for the 10 minute preheating process of white rice cooking,
Set it to 30 minutes. Cooking rice after preheating process (1st) (2nd)
(Third stage), twice-cooking, uneven cooking, and keeping warm are controlled in the same way as when cooking white rice. However, the reference time and heating duty for capacity determination are set to specific values based on experimental data for cooking brown rice. .

For example, in the rice cooking (primary) process, timer data T1 is 4.
When the time is 00 seconds or more, it is determined as 10 cups, and when it is 140 seconds or less, it is determined as 1 cup. Also, in the rice cooking (secondary) process, timer data T2 is 1.
000 seconds or more, 10 seconds, 65, . When it is 0 seconds or less, it is determined as 1 go.

On the other hand, the heating duty of the rice cooking (secondary) process is 60 seconds for 10 cups/rice cooking heater ON (heating power 64 seconds 656W), 32 seconds for 1 cup/rice cooking heater 0N6
4 seconds (heating power 350W), and the heating duty of the rice cooking (tertiary) process is 58 seconds/64 seconds for 10 cups, rice cooking heater ON' (heating power 684 W), 16 seconds/1 cup for 1 cup.
The rice cooking heater is set to ON' (applied M'lE power +75W) for 64 seconds, and the boiling period is set to be slightly longer than when cooking white rice.

When rice cooking is selected using the menu select button 16 and the start key 19 is turned on, the designation of the flag 3 is determined and the corresponding control program is read out, thereby controlling as shown in the flowchart shown in FIG. In FIG. 8, the parts common to those in FIG. 6 are designated by the reference numerals in the frame in FIG. 6, and the details are omitted.

The steps of preheating, cooking (primary) (secondary), cooking twice/uniformly, and keeping warm are basically the same as for white rice cooking, and the different cooking (tertiary) steps are explained below. .

Some of the ingredients for cooked rice are added from the beginning of cooking, and others are added when the rice boils, so a boiling alarm is set in the rice cooking (tertiary) process so that the addition of ingredients can be detected. .

First, when moving to the rice cooking (tertiary) step, the alarm unit is sounded to notify boiling and prompt the addition of ingredients. After that, if no ingredients are added, cooking is performed by duty-controlling the rice-cooking heater 3 according to the heating duty determined in the rice-cooking (secondary) process, and the temperature detected by the first sensor 6 is When the temperature reaches 124°C, proceed to the next step.

On the other hand, when the lid is opened and the ingredients are added, the temperature detected by the second sensor 14 drops rapidly due to the inflow of outside air, as shown in FIG. 9, indicating that the detected temperature has fallen below 90°C. When the determination is made, the rice cooking heater 3 is continuously turned on and the heating electric cuff is heated at 00 W regardless of the heating duty, thereby raising the temperature in a short time until the temperature detected by the second sensor 14 reaches 90°C. And the second sensor 1
When it is determined that the temperature detected by the first sensor 6 reaches 90°C, the rice cooking heater 3 is thereafter duty-controlled until the temperature detected by the first sensor 6 reaches 124°C.

Note that the reference time and heating duty for capacity determination are set to specific values based on experimental data. For example, in the rice cooking (primary) process, when timer data T1 is 650 seconds or more, 10
If the time is 250 seconds or less, it is judged as 1 cup, and the rice is cooked (secondary).
In the process, when the timer data T2 is 800 seconds or more, it is judged as 10 cases, and when it is 400 seconds or less, it is judged as 1 case. The heating duty of the rice cooking (secondary) process is set to 64 seconds/64 seconds for 10 cups (heating electric cuff 00W), and 32 seconds/64 seconds for 1 cup (heating power 350W). The heating duty of the rice cooking (tertiary) process is 6 when the rice is 10 cups.
0 seconds/set the rice cooking heater ON (heating 64 seconds power 656W), 1 cup for 15 seconds/rice cooking bee ON for 64 seconds (heating power 164W).

When porridge cooking is selected using the porridge cooking menu select button 16 and the start key 19 is turned on, the designation of the flag 4 is determined and the corresponding control program is read out, thereby controlling as shown in the flowchart of FIG. 10. . In FIG. 1θ, parts common to those in FIG. 6 are designated by the symbols in the frame in FIG. 6, and details are omitted.

The preheating, rice cooking (first) (secondary) steps of porridge cooking are basically the same as those for white rice cooking, and the different rice cooking (tertiary) and twice-cooking/shading steps will be explained. Note that no heat-keeping step is provided in cooking the porridge.

In porridge cooking, the elapsed time from the start of cooking is counted, and the rice cooking (tertiary) step moves to the next stage of scouring step when a certain period of time (for example, 60 minutes) has elapsed from the start of cooking. The unevenness process ends when the rice cooking heater 3 is turned off and a certain period of time (for example, 5 minutes) has elapsed.

Note that the reference time and heating duty for capacity determination are set to specific values based on experimental data. For example, in the rice cooking (primary) process, when timer data T0 is 700 seconds or more, 10
If the time is 350 seconds or less, it is judged as 1 go, and in the rice cooking (secondary) process, when the timer data T2 is 900 seconds or more, it is judged as 10.
If it is 500 seconds or less, it is determined as 1 match. On the other hand, the heating duty of the rice cooking (secondary) process is - 1110 cups, the rice cooking heater is ON for 32 seconds/64 seconds (heating power 350 W), and when the rice cooking duty is 1 cup, the rice cooking heater is ON for 16 seconds/64 seconds (heating power + 75
W) and the heating duty of the rice cooking (tertiary) process.
16 seconds for 10 cups / Rice cooking heater ON (heat power + 75W' for 64 seconds), 12 seconds for 1 cup / Rice cooker 6
It is set to ON for 4 seconds (heating power 131W), and especially in the rice cooking (tertiary) process, the heating power is set to the minimum that can maintain boiling to prevent boiling over.

As described above, in this embodiment, the first and second sensors 6.
By controlling the rice cooking heater 3 based on a signal from the rice cooker 14, various kinds of cooking such as white rice cooking and brown rice cooking are performed. In addition, in various types of cooking, the time from the start of preheating to the end of double cooking and shading is controlled so that it is approximately constant regardless of the capacity, but this is disclosed in Japanese Patent Application Laid-Open No. 59-232.
This is to enable implementation of a rice finishing timer as disclosed in Japanese Patent No. 520 and the like.

In the above embodiment, the amount of cooked rice is determined twice using the same method, but the method of determination is not limited to the above method.
The method disclosed in Japanese Patent No. 282520 or the like may be adopted. In this method, while raising the food to be cooked from a certain temperature to a certain temperature, the set temperature is gradually increased in small increments, the ON time of the rice cooking heater is accumulated during this time, and the capacity is determined by the cumulative ON time of the rice cooking heater. This method uses the data as data and determines the amount of cooked rice based on this data. Therefore, such a method can be adopted not only for the first determination but also for the second determination in the case of white rice cooking which does not particularly require boiling detection.

Further, the second sensor 14 is not limited to the position in the above embodiment, but may be in any position as long as it can detect changes in the atmospheric temperature within the inner pot 4. However, it is desirable to thermally isolate it from the heat-retaining heater.

In addition, the present invention can be implemented with appropriate modifications within the scope of the invention.

(Effects of the Invention) As described above, according to the present invention, the temperature change of the food to be cooked is quickly responded to, the temperature change is accurately detected, and the heat retention heater on the main body side is controlled, while the outer lid side By accurately detecting and controlling the temperature of the atmosphere inside the inner pot, and by setting the temperature of the atmosphere inside the inner pot slightly higher than the temperature of the food being cooked, we have eliminated the phenomenon of condensation on the inner surface of the inner lid. A good heat retention state can be obtained as a whole.

[Brief explanation of drawings]

Fig. 1 is a schematic structural diagram of a jar rice cooker according to an embodiment of the present invention, Fig. 2 is a diagram showing the operating section of the above, Fig. 3 is a block diagram of the entire control circuit of the above, and Fig. 4 is a temperature detected by the sensor of the above. Fig. 5 is a diagram showing the relationship between the temperature detected by the sensor and the rice cooking power as the capacity changes, Fig. 6 is a flowchart for cooking white rice, Fig. 7
The figure is a flowchart for cooking brown rice as above, Figure 8 is a flowchart for cooking rice with rice mixed with same as above, Figure 9 is a diagram showing a model of the change in temperature detected by the second sensor in cooking rice with same as above, Figure 10 is porridge style as above. l: Main body, 4: Inner pot, 5: Heater, 6: First sensor, 7: Outer lid, 8
．． Insulating heater, 10, inner lid, 14: second sensor, 2
2. microcomputer. Agent Patent attorney Aihiko Fukushi (and 2 others) Figure 1O-1chi1-

Claims (1)

[Claims] 1. An inner pot that accommodates the food to be cooked, a main body that houses the inner pot, an inner lid that closes the opening of the inner pot, an outer lid that covers the outside of the inner pot, and an outer lid that is provided on the main body side. a heat retention heater, a first sensor that detects a temperature change at the bottom of the inner pot, a heat retention heater provided on the outer lid side, a second sensor that detects a change in atmospheric temperature within the inner pot, and a first sensor that detects a temperature change at the bottom of the inner pot; heat retention control means for controlling the heat retention heater on the main body side based on the signal from the second sensor and the heat retention heater on the outer lid side based on the signal from the second sensor, A cooking appliance characterized in that the set temperature is set slightly higher than the heat retention set temperature determined by the first sensor.