JPH0315889B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a rice cooker that cooks rice that is ready to eat after it has finished steaming when a timer is set.

(Prior Art) Conventionally, in a rice cooker, for example, a jar rice cooker,
Although various products equipped with a timer function are commercially available, all of these timers determine the time to start cooking rice, but not the time to finish the rice. On the other hand, the time when rice is most delicious is when the rice has been cooked and a certain amount of cooking time has elapsed. The more it gets, the more it tends to smell and change color.

(Problems to be Solved by the Invention) Therefore, conventionally, when trying to enable a user to eat rice at a desired time in the most delicious manner,
The user estimates the rice cooking time from the amount of cooked rice, adds the unevenness time to this, calculates the time from the start of cooking to the completion of unevenness, subtracts this time from the desired time, and sets the rice cooking start time using a timer. had to be set, which was extremely troublesome.

In general, the rice cooking process involves heating the rice soaked in water using a rice cooker to cook it, and then cutting off the electricity to the rice cooker and storing heat in the rice cooker itself or using the heater to gently heat the rice. It consists of a finishing step that promotes gelatinization of the rice and evaporates excess moisture, and is characterized by this finishing step, a special cooking step that is not found in other heating cooking processes.

However, although the end of the rice cooking process is relatively easy for the user to notice when the rice cooking heater is shut off, most of the finishing process involves simply leaving the heater without electricity, so when does the finishing process end? In other words, it was difficult to know when the rice would be ready to eat after it had been cooked. Even if you set the time to start cooking rice using a timer, the finished time is often inaccurate because the user sets the cooking time as described above, and it is difficult to know when the rice will be ready to eat at the desired time. . Even if you can set the finishing time accurately, the time for the rice cooking process may vary depending on various surrounding conditions, and you may wonder if the rice is ready to eat at the desired time. I'm sure the users were worried.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a timer for arbitrarily setting the time when rice is finished, and a rice cooking process that starts from the time when rice is finished set by this timer. , a rice cooking control means for starting the rice cooking a certain time before the time required for the finishing process, so that the rice that is ready to eat after finishing the cooking process is cooked at the time set by the above-mentioned timer, and the rice cooking process is started from the finishing process. A rice cooker characterized by being provided with a display means that displays the irregularity time when the transition occurs, and also displays the irregularity time until the end of the irregularity while counting down the displayed irregularity time as the irregularity progresses. It is composed of

(Function) When the user cooks rice on a timer, the user sets the time when he wants to eat rice that is just about ready to eat.

By setting this timer, rice cooking is started a certain time before the time required for the rice cooking process and the finishing process, starting from the time when the rice is ready to eat. When the rice cooking process is finished, the process moves to a finishing process in which shading, etc. is performed, and at this time, the shading time required for the finishing process is displayed. This displayed uneven time is
As the finishing process progresses, the countdown is sequentially displayed until the end of the finishing process.

When the countdown ends, for example, when the unevenness time display shows "0", the unevenness or finishing process is completed, and the user understands that the rice is just finished and ready to eat. can do.

In this case, even if the end of the finishing process does not coincide with the desired time due to surrounding conditions,
The cooking time is counted down sequentially and displayed until the end of the cooking process, so you can definitely know the end of the finishing process by the end of the countdown, and you can be sure that the rice is cooked and ready to eat. You can check it.

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

First, FIG. 1 shows a schematic structure of the rice cooker of the present invention. In the figure, 1 is the main body of the jar rice cooker, 2 is an outer pot, 3 is a hot plate type rice cooker heater installed at the inner bottom of the outer pot 2, and 4 is an inner pot that can be moved in and out of the outer pot 2 and stores food to be cooked. , 5 is a heat-retaining heater provided on the outer surface of the outer pot 2, 6 is a thermosensor such as a thermistor that is in contact with the center of the outer bottom surface of the inner pot 4 and detects temperature changes of the food to be cooked, and 7 is provided on the outer surface of the outer pot 2. Thermal reed switch for heat retention that detects temperature changes in hot food, 8
9 is an operation panel provided on the outer surface of the main body 1, and 9 is a control board installed inside the operation panel 8. Although not shown in the drawings, it goes without saying that an inner lid for opening and closing the opening of the inner pot 4 and an outer lid for covering the outside of the inner pot 4 are provided as is well known in the art.

As shown in FIG.
It has an operation status display section 11 for rice cooking, etc., and also has a timer set key 12 and various control keys 13.

Next, FIG. 3 is a circuit diagram in which the present invention is implemented by a microcomputer, in which the rice cooking heater 3 is connected to the AC power source 15 through the contacts of the rice cooking pot relay 14, and the rice cooking relay 14 has a heat retention heater at the contacts. 5. A series circuit consisting of the contacts of the heat-retaining thermal reed switch 7 and the heat-retaining relay 16 is connected in parallel. Therefore, the rice cooking relay 14 and the heat retention relay 16 are turned on by the microcomputer described later.
OFF controlled, rice cooking heater 3 and warming heater 5
By controlling the power supply to the rice cooker, rice cooking or warming operation is executed. Both relays 14 and 16 are provided on a control board 9, and this board 9 is provided with a microcomputer, a time display element, a light emitting diode, a switch, etc.; Each display section 10, 11 and various keys 12, 1 of the operation panel 8
3 to correspond to a predetermined relationship. The power for the control section as described above is obtained from an AC power source via a transformer 17.

FIG. 4 is a block diagram of the entire control circuit. In FIG. 4, 18 is a microcomputer, mainly a central processing unit (hereinafter referred to as CPU) 19,
Electronic timer 20, read-only memory (below)
ROM) 21, arbitrary access memory (hereinafter referred to as
22 (referred to as RAM) and an interface (input/output signal processing circuit) 23. The ROM 21 stores a control program for the CPU 19, and the PAM 22 is used as a data memory for the CPU 19.

The CPU 19 reads the status of each part on the input side via the interface 23, and
By reading the control program in the ROM 21, processes such as preheating, capacity determination, boiling, double cooking, uneven cooking, and keeping warm are determined, and the heating parts necessary for executing the processes are controlled via the interface 23. The process is controlled by an electronic timer 20 in cooperation with the CPU 19. The electronic timer 20 counts a predetermined time according to instructions from the CPU 19 and outputs a signal after the predetermined time.

In the above configuration, the control will be explained in detail below.

First, FIG. 5 is the main flowchart of the rice cooker of the present invention, in which the steps of primary preheating, secondary preheating, capacity determination, cooking, double cooking, uneven cooking, and heat retention are sequentially executed from the start of rice cooking. Each process other than the cooking process and the warming process is executed for a predetermined time (constant). Further, the cooking process is completed by detecting the temperature of the food to be cooked, and by employing a control method which will be described in detail later, the temperature is kept approximately constant. Incidentally, FIG. 6 is a curve diagram showing the relationship between the elapsed time from the start of cooking rice to keeping it warm and the temperature change of the food to be cooked. Control of each process will be explained below.

● Primary and secondary preheating process Press the control key 13 for rice cooking and timer start.
When turned on, this is stored in the storage means A in the CPU 19, and the control program contents in the ROM 21 corresponding to the stored contents are read out.
A flowchart of the primary preheating step shown in FIG.
Subsequently, control is performed as shown in the flowchart of the secondary preheating step shown in FIG.

In the primary preheating process, when the rice cooking/timer start control key 13 is turned on, the set temperature of the thermosensor 6 is set to a predetermined temperature _t1 , and the contact of the rice cooking relay 14 is turned on to start energizing the rice cooking heater 3. Preheat food for a certain period of time
T ₁ go. The temperature setting of the thermosensor 6 and the determination as to whether the set temperature has been reached are performed as follows. The temperature detected by the thermosensor 6 is converted into a digital signal by digital-to-analog conversion and read into the CPU 19, where the digital signal is
It is compared with the set temperature stored in the ROM 21, and a match or mismatch is determined.

The rice cooking heater 3 is continuously energized until the temperature of the thermosensor 6, which detects the temperature of the food to be cooked, reaches a predetermined temperature _T1 . However, the above
If the temperature of the thermosensor 6 does not reach the predetermined temperature even after T ₁ hours have elapsed, the process moves to the next stage of secondary preheating step after T ₁ hours have elapsed.

Conversely, if the temperature of the thermosensor 6 reaches the predetermined temperature _T1 within _T1 hour, the remaining time is set to ON-MAX for several tens of seconds (for example, 15 seconds) and OFF-Fix for several seconds (for example, 5 seconds). By switching to intermittent control, control is performed to maintain the predetermined temperature _t1 as much as possible. This intermittent control will be explained.
Now, if the temperature of the thermosensor 6 reaches the predetermined temperature _t1 due to continuous energization of the rice cooking heater 3 and the energization to the rice cooking heater 3 is stopped, the temperature determination means B in the CPU 19 stops the energization to the rice cooking heater 3. When 5 seconds have passed from the time, it is determined whether the temperature of the thermosensor 6 is higher than the predetermined temperature _t1 , and if it is higher, the power supply to the rice cooking heater 3 is continued to be stopped, and the temperature of the thermosensor 6 is lowered below the predetermined temperature _t1 . At this point, the rice cooking heater 3 is energized. Conversely, if the temperature of the thermosensor 6 is lower than the predetermined temperature _t1 , the power to the rice cooking heater 3 is restarted, and the thermosensor 6
When the temperature reaches the predetermined temperature _t1 , the power supply to the rice cooking heater 3 is stopped again, and the temperature of the thermosensor 6 is again determined after 5 seconds have elapsed since the power supply was stopped. Even if the rice cooking heater 3 is continuously energized for 15 seconds, if the temperature of the thermosensor 6 does not reach the predetermined temperature _t1 , the electricity to the rice cooking heater 3 will be stopped after 15 seconds have passed, and the electricity will be turned off again after 5 seconds have elapsed. The temperature of the thermosensor 6 is determined, and if necessary, the rice cooking heater 3 is energized.

As described above, within T ₁ hour, the sahi sensor 6
15 seconds if the temperature reaches the specified temperature t ₁
It performs intermittent control of ON-MAX and 5 seconds OFF-Fix, and an example of the control state is shown in FIG. Note that the above 15 seconds or 5 seconds is not particularly limited, and depends on the size of the rice cooker,
The time can be determined at any time depending on the size, structure, etc. of the rice cooking heater.

Therefore, such a primary preheating process is aimed at correcting the temperature of the food to be cooked relative to the water temperature and air temperature at the beginning of rice cooking, and even when the water temperature or air temperature at the beginning of rice cooking is low, the temperature of the food to be cooked is corrected. This is to enable the temperature rise to keep up with the control mode described later.

In addition, the above 15 seconds ON-MAX, 5 seconds OFF-Fix
The reason for introducing intermittent control will be explained in detail in the next stage of the secondary preheating process.

In the secondary preheating process, the temperature of the food that has been raised to a predetermined temperature t ₁ in the primary preheating process is further increased to temperature t ₂ over a certain period of time T ₂ , and the above temperature is increased over the entire T ₂ hours. 15 seconds ON−
Execute the intermittent control method of MAX, 5 seconds OFF-Fix, and set the temperature of the thermosensor 6.
Every time a certain period of time elapses, e.g. 52 seconds, e.g. 2
Increase the temperature by ℃.

Now, when the primary preheating process is completed and the process proceeds to the secondary preheating process, the set temperature of the thermosensor 6 is changed to (t ₁ +
At the same time, set the temperature interval time T ₃ to 52 seconds, turn ON-MAX for 15 seconds, and set the temperature to 2℃).
Secondary preheating of the food to be cooked is started by controlling power supply to the rice cooking heater 3 using an intermittent control method of OFF-Fix seconds. Then, the set temperature of the thermosensor 6 is increased by 2 degrees Celsius every time 52 seconds pass, and eventually the set temperature of the thermosensor 6 reaches the _t2 temperature after a certain period of time _T2 has elapsed since the start of secondary preheating. , flag area C of RAM22
Once specified, the process moves to the next stage capacity determination step.

This secondary preheating process promotes water absorption of the rice, and makes the temperature of the cooked food constant and uniform when moving to the next capacity determination process, regardless of the rice cooking capacity. The purpose of this is to enable accurate capacity determination. Therefore, it is desirable to set the _t2 temperature to around 60°C, and it is also desirable to set the _T2 time to about 8 to 10 minutes.

Here, 15 seconds ON-MAX, 5 seconds OFF-Fix
Let me explain why we adopted this intermittent control method. In the case where the set temperature of the thermosensor 6 is gradually increased as in the present invention, if the rice cooking heater 3 is continuously energized for too long,
Figure 10a shows the overshoot of the thermosensor temperature after the power supply to the rice cooking heater 3 is stopped.
By adopting an intermittent control system, where the overshoot becomes too large and ideal control cannot be achieved, as shown in FIG. 10b, the overshoot can be suppressed to a small value and ideal control becomes possible. Also, the temperature difference between the top and bottom of the food, especially the water,
Although it does not eliminate the problem, it can be significantly alleviated compared to continuous energization.

The preheating control means for executing the primary and secondary preheating steps as described above corresponds to the rice cooking/timer start control key 13, the storage means A in the CPU 19, the temperature determination means B, and the contents stored in the storage means A. It is composed of the control program contents of the ROM 21, a thermosensor 6, a rice cooking relay 14, and the like.

● Capacity determination process When the secondary preheating process moves to the capacity determination process, control is performed as shown in the flowchart shown in FIG. do.

In this capacity determination process, the temperature of the food that has risen to temperature t ₂ is raised to temperature t ₃ over a certain period of time T 4. During this time, the temperature of the cooked food that has risen to temperature t ₂ is increased to temperature t ₃ . ON-MAX, 5 seconds
While executing the OFF-Fix intermittent control method, the set temperature of the thermosensor 6 is increased by, for example, 2 degrees Celsius every time a certain period of time, for example 40 seconds, as shown in Fig. The energization time is stored in the rice cooking capacity determination data storage area in the RAM 22 and integrated.

Now, proceeding to the capacity determination step, the set temperature of the thermosensor 6 is set to (t ₂ + 2°C), and the temperature interval time T ₅ is set to 40 seconds.
Executes an intermittent control method of 15 seconds ON-MAX and 5 seconds OFF-Fix. During this time, if the temperature of the thermosensor 6 is lower than the set temperature, the rice cooking heater 3 is energized for a maximum of 15 seconds to heat and raise the temperature of the food, while adding up the energization time to the rice cooking heater 3. go. In this way, every time 40 seconds elapse, the set temperature of the thermosensor 6 is increased by 2 degrees Celsius, and the energization time to the rice cooking heater 3 is integrated, and eventually T ₄ hours have passed since the start of the capacity determination process. When the set temperature of the thermosensor 6 reaches the _t3 temperature and the flag area D of the RAM 22 is designated, the rice cooking capacity is determined based on the cumulative energization time of the rice cooking heater 3. In addition, in the capacity determination step, the timing of energizing the rice cooking heater with respect to changes in setting and measurement temperature is determined by the 13th
An example is shown in the figure.

In the capacity determination step, the _t3 temperature is not particularly limited, but is preferably determined within the range of 85°C to 90°C. That is, in the structure of the rice cooker as shown in the first diagram, t ₂ (around 60℃)
The temperature range from t3 _{to t3} (85 to 90°C) is the temperature range in which the rice cooking heater energization time changes the most with respect to the size of the rice cooking capacity, and is the most preferable period for collecting rice cooking capacity determination data.

Next, determination of rice cooking capacity will be explained. The rice cooking capacity is determined by reading the rice cooking capacity determination program stored in the ROM 21 in advance based on the designation of the flag area D.
The rice cooking capacity is determined as shown in the flowchart shown in Figure 4, and the heating sequence for the next stage of the cooking process is determined. This heating sequence is a heating power adjustment, and specifically, a so-called duty control method is adopted, which is a method of adjusting the time during which the rice cooking heater 3 is energized within a certain period (for example, 64 seconds). The heating duty for the next stage of cooking, which is determined as a result of the capacity determination, is determined by applying a heater voltage suitable for the rice cooking capacity, but in order to completely gelatinize the rice, it is necessary to
The conditions are that the rice should be kept for at least 30 minutes, that there should be no boiling over, and that the cooking time should be constant.

In addition, the rice cooking capacity is determined to be accurate to a certain degree by taking into consideration the accumulated time of energizing the rice cooking heater, the power supply voltage when the rice cooking heater is energized, and whether the rice is cooked on a timer or immediately. That is, the 15th
As can be seen from the experimental data shown in the figure, even when the cumulative energization time of the rice cooking heater is the same, the rice cooking capacity determination result varies greatly depending on the level of the power supply voltage and whether rice is cooked on a timer or not. For example, the cumulative time
In the case of 240 seconds, the rice cooking capacity judgment value fluctuates over the range of 3 to 8 cups. Therefore, it is possible to perform accurate capacity judgment by performing program processing based on the above three conditions. The mechanism is shown in the flowchart in Figure 14. still,
The above-mentioned timer rice cooking will be explained in detail later, but in the case of timer rice cooking, the diagram from the time setting to the start of rice cooking is shown below.The rice is immersed in water and has absorbed some water at the start of cooking, so rice can be cooked immediately. The amount of water absorbed by rice is different compared to rice, and as a result, even if the rice cooking capacity is the same, there is a difference in the cumulative energization time of the rice cooker.As a result, when determining the rice cooking capacity, timer rice cooking is considered to be different from instant rice cooking. The amount of water absorbed by the rice is corrected by adding .

In FIG. 14, the rice cooking capacity is determined at the end of the capacity determination process. First, RAM22
By reading out the timer rice cooking determination contents temporarily stored in the , it is determined whether the rice cooking currently being executed is timer cooking or immediate cooking. Furthermore, RAM2
2, the time setting means E reads whether or not the time has been set using the timer set key before the rice cooking/timer start key is operated, and this is temporarily stored in advance. When this determination is completed, the value of the power supply voltage is compared with the value stored in the ROM 21 while the power is on, and it is determined whether the power supply voltage is in the low voltage, standard voltage, or high voltage range. After that, the rice cooking capacity is determined as shown in the flowchart of FIG. 16 based on the cumulative energization time of the rice cooking heater. The rice cooking capacity is divided into 6 categories depending on whether it is timer rice cooking or instant rice cooking, and the state of the power supply voltage for each type of rice cooking.Furthermore, each category is divided into 10 stages according to its own time width, and the cumulative time of energization of the rice cooking heater is divided into 10 stages. A heating duty is set for each capacity as described below, and the contents of these programs are stored in advance in the ROM 21.

After determining the power supply voltage, the rice cooking heater energization cumulative time T _R temporarily stored in the RAM 22 is determined.
At the same time, the rice cooking capacity is determined by reading out the rice cooking capacity determination program in the ROM 21 as shown in the flowchart shown in _FIG . By sequentially subtracting, the rice cooking capacity when the relationship T _R <0 is established is determined, and the heating duty is determined based on this determined capacity G ₀ . In this manner, when the flag area F of the RAM 22 is designated after _T4 time has elapsed, the process moves to the next blow-up step.

As described above, in the capacity determination process, the thermosensor 6
By increasing the set temperature of T by 2℃ every ₅ hours and executing an intermittent control method of ON-MAX for 15 seconds and OFF-Fix for 5 seconds, the temperature of the food to be cooked can be raised from _T2 temperature to _T3 temperature. The rice is raised for ₄ hours, the time during which electricity is applied to the rice cooking heater 3 is accumulated, and the rice cooking capacity is determined based on this accumulated electricity application time, taking into account the state of the power supply voltage and whether it is timer rice cooking or instant rice cooking. , determine the heating duty in the cooking process.

As can be seen from Figure 14, the number of determinations for rice cooking capacity is 60 types in 6 categories and 10 stages, all with different heating duties set, and this heating duty is calculated based on the formula below. There is.

Heating power = (cooking capacity) x (specific heat) x (
temperature rise)/(heating time a)... Heating power = (water amount) x (latent heat of evaporation)/(heating time b
)... The above formula is the formula to calculate the heating power until boiling, and the formula is the formula to calculate the heating power after boiling. Here, by keeping the cooking time (+) constant, the heating power (+) can be calculated from the formula. Then, a heater of a size that has a margin for the maximum value of the heating power (+) determined in this way is adopted as a rice cooking heater, and by controlling the duty of this heater, the heating power suitable for each capacity is adjusted. produce.

In this duty control, the time _T6 for energizing the rice cooking heater 3 within a certain period is determined by the following formula (see Fig. 17).

T ₆ = Heating power/size of rice cooking heater x period (64 seconds)... However, this is a value set in consideration of the lifespan of the rice cooking relay 14, and is not particularly limited to this value. .

● Cooking process When moving to the cooking process, the duty of the rice cooking heater 3 is set by reading the heating program contents corresponding to the heating duty determined in the previous capacity determination process from the ROM 21 based on the specification of the flag area F of the RAM 22. The temperature of the food is heated up to the cooking temperature _t4 (approximately 124 degrees Celsius), and when the temperature exceeds _t4 , the thermosensor 6 detects the temperature, ends the process, and flags the RAM 22. G
is specified and moves on to the next stage of twice-cooking and shading process (see the flowchart in Figure 18).

This cooking process differs from the previous steps in that it detects that the temperature of the thermosensor 6 has reached the _t4 temperature and starts the flow, so there is an element of temporal instability, but the rice cooking capacity By determining the heating duty suitable for this and controlling the duty of the rice-cooking heater in the relevant process based on this, the time _T7 required for the rice-cooking process has extremely small fluctuations. It will be a fixed amount of time.

● Double-cooking/uneven process In the double-cooking/uneven process, the burn setting contents temporarily stored in the RAM 22 are read based on the designation of the flag area G of the RAM 22, and the settings in the ROM 21 corresponding to the setting contents are read out. By reading the control program contents, the first
Control is performed as shown in the flowchart shown in FIG. 9, and after a certain period of time T ₈ (for example, 12 minutes), the lag area H of the RAM 22 is designated and the process is moved to the warming process.

First, to adjust or set the burn, press the control key 13 for burn adjustment to select "Standard" →
"Light" → "Standard" → "Dark" → "Standard" → "Light"
The setting can be repeated as follows, and the burn degree determining means 1 counts the number of times the control key 13 is pressed, and then temporarily stores the burn setting contents in the RAM 22. Then, when moving to the double-cooking/smoothing process,
The burn setting contents are read out from the RAM 22, and the control program contents in the ROM 21 corresponding to these contents are read out, thereby controlling as shown in the flowchart shown in FIG. Each figure in Fig. 20 shows the relationship between the temperature change of the thermosensor and the energization state of the rice cooking heater in the same process, where a is when set to "Light", b is when set to "Standard", and c is when set to "Standard". Indicates when set to “Dark”.

If it is currently set to "Light", it detects that the temperature of the thermosensor 6 has fallen below the _t4 temperature (124℃) and starts counting the time, and when one minute has passed, the rice cooker heater 3 is activated for a short time. Electricity is applied (for 5 seconds) to burn the food, that is, rice, and then electricity to the rice cooking heater 3 is stopped.

When set to "Standard", it detects that the temperature of the thermosensor 6 has fallen below the _t4 temperature and starts counting the time, and when one minute has elapsed, the rice cooking heater 3 is energized and the thermosensor 6 is activated. The food to be cooked is heated until the temperature reaches _t4 temperature, and when the temperature reaches _t4 temperature, the power supply to the rice cooking heater 3 is stopped and the rice cooking heater 3 is thereafter in a stopped state.

If it is set to "Dark", the above "Standard"
Similarly, one minute after the temperature of the thermosensor 6 falls below the _t4 temperature, the rice cooking heater 3 is energized to raise it again to the _t4 temperature.
Then again, the temperature of thermosensor 6 is t ₄
Count for 1 minute from the time the temperature drops below the
After one minute has elapsed, the rice cooking heater 3 is energized and the food is heated again until the temperature of the thermosensor 6 reaches the _t4 temperature, after which the power outage is stopped.

Therefore, the double-cooking and shading process starts from the beginning.
T Ends after ₈ hours and RAM22
The flag area H is designated and the process moves to the heat retention process. This double-cooking/smoothing process finishes the rice by draining the cooked rice and adjusting the burntness, and by completing this process, the rice is thoroughly cooked and the rice is ready to eat. It will be done.

Incidentally, the burn setting can be made arbitrarily before proceeding to the double-cooking/unshading process, and subsequent setting operations will be invalid.

As described above, the rice cooking control means includes preheating control means,
It includes each flag area of the RAM 22, program contents in the ROM 21 corresponding to each area, other memory contents in the electronic timer 20, ROM 21, and RAM 22, etc. By determining the capacity and controlling energization to the rice cooking heater 3 based on the determination result, rice cooking is completed in a substantially constant rice cooking time from the start of rice cooking (start of primary preheating),
It is configured so that the rice is finished after a certain amount of time after the completion of cooking.

● Heat retention process When moving to the heat retention process, the heat retention relay 16 is activated.
ON, and this ON state is the control key 1 for cancellation.
Continues until 3 is pressed. Control in the heat retention process is performed by a heat retention thermal reed switch 7 that detects changes in the temperature of the food to be cooked, and as shown in FIG. This is to control the power supply to 5 to keep the rice, which is the food to be cooked, warm. The temperature setting of the thermal reed switch 7 is set to a temperature suitable for keeping rice warm, for example, 70°C.

Next, the rice finishing timer means will be explained. This timer means is for executing the above-mentioned timer rice cooking, and is configured to arbitrarily set a finishing time and to start cooking rice by the above-mentioned rice cooking control means at a fixed time when the set time ends.

The rice finishing timer means includes a time setting means E in the CPU 19, a rice cooking start determination means including the program contents specified by the flag, a display control means including the program contents specified by the flag, and a time setting means in the ROM 21. The program consists of an electronic timer 20, a RAM 22, a time display element (time display section 10), a timer set key 12, and a rice cooking and timer start control key 13, which will be explained in order below.

First, the time is set by reading the input state of the timer set key 12 with the time setting means E, and reading out the contents of the time setting program and the contents of the display program from the ROM 21.
This is carried out as shown in the flowchart of FIG.

In FIG. 22, the timer set key 12
When the time key is pressed, the time data will be counted up one hour at a constant cycle while the key is pressed, and the time display element will display the time in the order of 1, 2, 3, etc. The time will be set to a maximum of 12 hours. Next, when you press the minute key, the display by the hour display element switches to the minute display, and while the minute key is pressed, the minute data is counted up in 10 minute increments at a constant cycle, and the time display element The minutes are displayed in the order of 10, 20, 30, etc., and finally, by pressing the rice cooking/timer start control key 13, the hours and minutes are set and the timer is put into operation. The time display element is normally in the time display state and switches to minute display only when the minute key is pressed.

In addition, control key 13 for rice cooking and timer start
If no key is pressed for a certain period of time (for example, 4 seconds) before pressing , the display switches to timer start standby mode (for example, the hours and minutes are displayed alternately), and then continues for a certain period of time (for example, 3 seconds). minutes), it switches to cancel mode (e.g. 88 blinking display).

In the timer actual operation state, the display control is performed by counting down the time data from the set time and reading out the contents of the display program, as shown in the flowchart shown in FIG. In other words, as time passes, the time display element counts down in hour units to display the remaining time until the rice is finished, and when the remaining time is less than one hour, the time display element displays the time. from C ₀
(abbreviation for COOK) display to indicate that rice cooking has started from rice cooking standby. Then, at the same time that the temperature of the thermosensor 6 reaches the _t4 temperature and the cooking process shifts to the double-cooking/uniforming process, the _C0 display by the time display element is switched to the minute display, and the double-cooking/uniforming process Execution time of T ₈
That is, 12 minutes will be displayed, and the countdown will continue in 1-minute increments, and the remaining time until the rice will be finished will be displayed, and the 0 minute display will coincide with the end of the double-cooking and shading process. When moving to the body temperature step, the time data is counted up, the elapsed time of keeping warm is displayed by the time display element, and the time is counted up in units of one hour.

On the other hand, the determination to start rice cooking is made by determining whether the remaining time until the finishing time has reached T ₀ hours (time shorter than 1 hour), and when the time T ₀ has reached, rice cooking is started by the rice cooking control means. the above
T ₀ time is determined based on the total time of T ₁ , T ₂ , T ₄ , T ₇ , and T ₈ . In making this decision,
There is no problem because each time T ₁ , T ₂ , T ₄ , T ₇ , and T ₈ is a constant time, but as explained in the previous cooking process, T ₇ hours includes unstable elements, so
T ₇ It is necessary to consider how much time to expect. However, as explained earlier, although there is some variation in T ₇ hours, it is a nearly constant time, so it was determined based on experimental data, and T ₁ ,
If T ₀ time is determined by including each time of T ₂ , T ₄ , and T ₈ , there will be a difference between T ₀ time and the time actually required from the start of cooking to the finished rice, but the difference is T ₀ time If you look at it as a whole, it can be kept extremely small.

In addition, in the time display section 10, the time from C ₀ display to switching to minute display due to the start of the double-cooking/smoothing process is calculated to be 48 minutes, but in reality it is an unstable time of T ₇ . are included, so they do not necessarily match. However, the time zone that includes T ₇ is
C ₀ display, no time display, the time difference is extremely small, and the 0 display coincides with the end of the cooking process twice, so the reliability of the user is not compromised. , it is possible to almost accurately obtain the rice that is most ripe for consumption at the desired set time.

Here, rice cooking using the rice finishing timer means, ie, timer rice cooking, will be briefly explained with reference to the flowchart shown in FIG.

Suppose that under standard voltage, 4 cups of rice is heated to 12
If you want to finish the rice after a certain amount of time and give it a standard degree of charring, first wash 4 cups of rice and store it in the inner pot 4, then fill the inner pot 4 with water accurately to the specified water level.
Place it in the outer pot 2 and close the lid. Next, insert the power plug into the outlet, turn on the power, and press the time key of timer set key 12 to set the time to 12 hours.
By pressing the timer start control key 13, the timer is brought into operation.

Then, as time passes, the remaining time is displayed on the time display section 10 in 1 hour increments, and eventually
When 11 hours have passed and the remaining time is less than 1 hour, C ₀ is displayed on the time display section 10, indicating that the rice cooking start standby state has entered.

Furthermore, when time passes and the remaining time reaches T ₀ hours, rice cooking starts and the primary preheating process is executed, and after T ₁ hour has passed, the secondary preheating process has been started, and after T ₂ hours have passed, the capacity has been determined. Move on to the process. In this capacity determination process,
By increasing the set temperature by 2 degrees Celsius every _T5 , and executing an intermittent control method of 15 seconds ON-MAX and 5 seconds OFF-Fix, the electricity supply time of the rice cooking heater 3 during this period is accumulated, and this The cumulative time is collected as rice cooking capacity determination data.
Then, when T ₄ hours have passed, the power supply voltage,
The rice cooking capacity is determined based on whether the rice is cooked by a timer or instantaneously, and the rice cooking capacity is determined based on the cumulative energization time of the rice cooking heater.The heating duty corresponding to this is determined, and the process moves to the next stage of cooking. In addition, in the case of this rice cooking example,
Enter the area of Figure 14 (2-4), (2-4)
A heating duty corresponding to the region is selected.

When moving to the cooking process, the rice is cooked by heating at the previously determined heating duty. Then, when the temperature of the thermosensor 6 reaches the _t4 temperature and the rice is cooked, the time goes to the double-cooking/uniforming step, and at the same time, the time display section ₁₀ displays T8 hours, that is, 12 minutes. still,
By operating the burn adjustment control key 13 before starting the double-cooking/unevening process,
Set the degree of burntness to "Standard".

In the double-cooking and uneven cooking process, double-cooking and browning are executed by controlling the rice cooking heater 3 as shown in FIG. At the same time, the process ends and the process moves to the heat retention process.
Therefore, this time is about 12 hours after pressing the rice cooking/timer start control key 13.
You will get rice that has been thoroughly milled and is ready to eat.

Note that the minute display in the double-cooking/uncoating process is performed not only when rice is cooked on a timer but also when rice is immediately cooked.

(Other Examples) (1) In the above embodiment, the state of the power supply voltage is taken into consideration when determining the rice cooking capacity, but the state of the power supply voltage does not need to be taken into consideration. In this case, the variation in the time T ₇ in the cooking process will be larger than in the above embodiment, and the difference between the set desired finishing time and the actual finishing time will also be large. Compared to estimating the rice cooking time and adding the unevenness time to this to calculate the time from the start of cooking to the completion of unevenness, subtracting this time from the desired time and setting the rice cooking start time with a timer. The difference between the desired finishing time and the actual finishing time is kept extremely small, and the accuracy is high.

(2) Also, timer rice cooking and
It is also possible to omit the ready-to-cook rice. In this case as well, the same thing as (1) above can be said, but the intended purpose of the present invention can be achieved and the gist of the present invention is not departed from.

(3) In the above embodiment, even in the case of instant cooking, the execution time T ₇ of the cooking process is controlled to be approximately constant, as in the case of timer _cooking . There is no need to keep the time constant, and if the amount of rice is small, it may be possible to cook the rice in a short time based on the determination of the rice cooking capacity.

In addition, the present invention is not limited only to the embodiments described above and shown in the drawings, and it goes without saying that the present invention can be practiced by appropriately changing the temperature, time, etc., without departing from the scope of the invention.

(Effects of the Invention) According to the present invention, if you set the timer just when you want to eat rice that is ready to eat, you can start the rice cooking process.
Rice cooking will automatically start a certain amount of time before the finishing process, and when you set the timer, the rice will be ready to eat as soon as the rice is finished cooking.

In this case, when the rice cooking process moves to the finishing process, the unevenness time is displayed and the unevenness time is displayed while counting down sequentially until the end of the finishing process, so the user can know when the rice is ready to eat. The end of the finishing process can be reliably recognized by the end of the countdown of the irregularity time without having to worry about the end of the finishing process.

In addition, even if the finish time of the finishing process does not coincide with the desired time due to surrounding conditions, the finish time countdown display will ensure that the finishing process has finished, that is, the rice is ready to eat. Since it is possible to know when the rice is ripe, it is possible to accurately notify the user when the rice is ready to eat without giving the user a sense of anxiety about the failure or the reliability of the device.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the general structure of the rice cooker of the present invention, Fig. 2 is a front view of the operation panel section of the above, Fig. 3 is a circuit diagram of the heater circuit of the above, Fig. 4 is a block diagram of the entire control circuit of the above. Figure 5 is the main flowchart of the above, Figure 6 is a curve diagram showing the relationship between the time elapsed from the start of rice cooking to keeping it warm and the temperature change of the food, and Figures 7 and 8 are the primary and secondary preheating steps of the above. FIG. 9 is an explanatory diagram showing the intermittent control state of the rice cooking heater, FIG. 10 a and b are explanatory diagrams for comparing continuous energization and intermittent energization of the rice cooking heater, and FIG. A flowchart for collecting judgment data in the judgment process, Fig. 12 is a diagram showing changes in the set temperature in the capacity judgment process, Fig.
The figure shows the timing of energization to the rice cooking heater with respect to the setting and measured temperature in the capacity determination process as above, Figure 14 is a flowchart for determining the rice cooking capacity in the capacity determination process as above, and Figure 15 shows the integrated energization of the rice cooking heater in the capacity determination process as above. Experimental data showing the relationship between time and rice cooking capacity, Fig. 16 is a flowchart for determining the rice cooking capacity as above, Fig. 17 is an explanatory diagram showing the control state of the rice cooking heater in the cooking process as above, Fig. 18 is the cooking process as above. Figure 19 is a flowchart of the same double-cooking and unevenness process, and Figures 20 a to c are the same twice-cooked and uneven process.
A diagram showing the relationship between the temperature change of the thermosensor and energization to the rice cooking heater in the heating process, FIG. 21 is an explanatory diagram showing the control state of the heat retention heater in the heat retention process, and Figure 22 is a flowchart for setting the timer. FIG. 23 is a time display flowchart. 3: Rice cooking heater, 4: Inner pot, 6: Thermosensor, 12: Timer set key, 13: Rice cooking, timer start key, 18: Microcomputer.

Claims (1)

[Claims of Claims] 1. A timer for arbitrarily setting the time when rice is finished, and a rice cooking control that starts cooking rice a certain period of time necessary for the rice cooking process and finishing process from the time when the rice is finished set by the timer. The rice cooker is equipped with a means to ensure that the rice that is ready to eat after the cooking process is completed at the time set by the above-mentioned timer, displays the cooking time when the rice cooking process moves to the finishing process, and also controls the progress of the cooking process. A rice cooker characterized by being provided with a display means for displaying the uneven time until the end of the uneven cooking while counting down the displayed uneven time.