JPS59144420A - Automatic rice cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to rice cookers, and particularly to rice cookers using a microcomputer as a control circuit.

Conventional technology Cooking equipment with built-in microcomputer
By setting a predetermined rice cooking program in the OM (read only memory) in advance, the rice cooking operation according to the program can be automatically performed.

However, such automatic rice cookers operate according to a set rice cooking program with time and temperature as factors, so if you want to inspect the rice cooking operation during the production process, it will take several tens of seconds.
It will take several minutes. Therefore, it is necessary to provide a means for checking the rice cooking operation in a short time.

Purpose: In view of the above-mentioned problem numbers, the present invention aims to provide an automatic rice cooker equipped with a test mode function that allows rice cooking operation to be confirmed in a short period of time.

MQ I Figure 1 schematically shows the structure of the present invention.

1 is a rice cooking switch for starting and stopping the rice cooking operation, and 2 is a timer switch for setting the time until the rice cooking operation starts. 3 is a program rice cooking operation control means for performing rice cooking according to a preset rice cooking program;
4 is a timer means for operating the program rice cooking operation control means 3 after the time set by the timer switch 2 has elapsed, and 5 is a normal rice cooker that performs the rice cooking operation at a constant energization level without following the rice cooking program. It has one stage of operation control. 6 manually inputs signals from the rice cooking switch 1 and the timer switch 2, and from the combination of these signals, the programmed rice cooking operation control means 3, the timer means 4, or the normal rice cooking operation control means 5.
This is a switch determination means that selects one of them and puts one of them into an operating state.

The operation of the switch determination means 6 is such that, for example, when the rice cooking switch 1 is pressed after the timer switch 2 sets the time in the timer means 4, the timer means 4 is activated, and when only the rice cooking switch 1 is pressed, the timer means 4 is activated. The program rice cooking operation control means 3 is operated, and after the start of the program rice cooking operation, the rice cooking switch 1 is pressed while the timer switch 2 is kept pressed, 115, and when the rice cooking switch 1 is released first, the program rice cooking starts. This is to stop the operation of the control means 3 and shift to a test mode in which the normal rice cooking operation control means 5 is operated.

In the present invention, the test mode function refers to the rice cooking switch 1 and the timer switch 2, as in the third operation above.
This refers to a function that allows a transition to the normal rice cooking operation control means 5 by the operation of .

FIG. 2 shows a schematic sectional view of one embodiment.

10 is a rice cooking heater provided to heat the bottom surface of the inner pot 12 of the rice cooker 11 via a heat transfer member 13, and 14 is a heat retention heater.

The rice cooking heater 10 is embedded in a heat transfer member 13 that contacts the bottom surface of the inner pot 12 so that the heat generated therein is effectively transferred to the bottom surface of the inner pot 12. The heat-retaining heater 14 is provided on the upper side surface of the outer container 15 so that heat is transferred to the inner pot 12 via the outer container 15. 16 is the bottom 7 of the inner pot 12:
A thermistor (hereinafter referred to as the first thermistor) as an example of a thermistor (hereinafter referred to as the first thermistor) detects 1a degrees, and 17 is a thermistor (hereinafter referred to as the first thermistor) as a side temperature element to detect the side temperature of the 1st pot 12. 2nd thermistor).

The first thermistor 16 and the second thermistor 17 are brought into contact with the bottom and side surfaces of the inner pot 12, respectively, due to the pressing force of a spring, and the detection signals of both thermistors 1617 are connected to be input to the microcomputer 18. #19 is a power supply circuit and one microcomputer 18
20 receives the control signal from the rice cooker 10 and the heat-retaining heater 14.The microswitch 20 detects whether the inner pot 12 is in use or not, and if the inner pot 12 is present, it is turned on and the power is turned on. The circuit 19 is turned on and the power supply circuit 19 is turned off until the inner pot 12 is placed to prevent dry cooking.21 is the lid of the inner pot. The surrounding area is filled with a heat insulating material for heat retention, and the lid 21 can also be provided with a known pressure regulating device. 22
is a control unit containing a microcomputer 18, which is installed on the outer body of the rice cooker 11, and is equipped with a burn switch 23, which will be described later, in addition to the rice cooking switch 1 and timer switch 2, as switches for controlling the rice cooker. There is.

FIG. 3 shows an electric circuit system directly related to the operation of the rice cooking heater 10 in this embodiment. The first thermistor 16 on the bottom side of the inner pot and the second thermistor 17 on the side surface each have a resistance R.
1, is provided between the power supply VDD and ground via R2 - each detection signal is connected to the microcomputer 18.
The A/D converter input capo) R2, KIG is input and converted into a digital signal. The signals of the rice cooking switch 1 and the timer switch 2 are also sent to the microcomputer 1.
You can input 8.

The microcomputer 18 controls the gate signal of the triac 25 via the driver 24 by sending an on/off signal to the driver 24. The rice cooking heater 10 is connected to an AC power source 26 via its triax 25, thereby controlling on/off.

In this embodiment, the amount of electricity supplied to the rice cooking heater 10 is controlled by the duty ratio of the on time controlled via the triac 25. That is, the microcomputer 18
When the temperature signal from the first thermistor 16 and the second thermistor 17 is input, the heater is turned on for an appropriate period of time at a certain time interval (for example, 15 seconds) so that the heater is energized to an appropriate level according to a generally established rice cooking mode program. A signal is output and the driver 24 turns on the triac 25. Since the rice cooking heater 10 is energized and heated only while the triac 25 is on, the desired amount of energization (rice cooking power) can be achieved by changing the energized time.

Fig. 4 shows the panel of this embodiment (cooking control = L unit 2).The switches that the operator can operate include switch 1, timer switch 2, and browning switch 23, which can adjust the degree of browning according to the preference setting. There are 30
If the rice cooking operation is progressing according to the program,
A display panel that displays the progress of the program is provided with diodes 31 to 38 for each step, which are lit up one by one as the program progresses.■.

It is desirable that F and D 31 to 38 are appropriately color-coded.

40 and 41 are time display panels that display the remaining time until the rice cooking operation starts when the timer switch 2 & koyori timer cella are turned off, and 40 is a 2-digit 7-segment element that represents the time. 41 is a surface emitting element on which the number 30 (minutes) is displayed.

motion The operation of this embodiment will be explained.

FIG. 5 shows the relationship between the rice cooking mode program executed in one embodiment and the bottom temperature of the inner pot.

The first stage of the rice cooking operation is at a low temperature to allow the rice to absorb enough moisture, for example, for 6 minutes. This stage is called preheating mode. Next, increase the power of the rice cooking heater 10 to the maximum. This stage is called the middle Patsupa mode.

Then, when the detected temperature 13 of the second thermistor 17 exceeds 50°C, the contents 1-1 are judged from the temperature gradient,
The power supply is controlled according to the amount of contents.

This stage is set in power control mode. In this mode it will eventually boil over. After starting the power control mode, the rice cooking heater power is reduced to a predetermined percentage (for example, 70%) to maintain the boiling state. This stage is referred to as the boiling maintenance mode.

As the water continues to boil, the water will eventually disappear and the temperature will begin to rise. When the temperature reaches a predetermined temperature (for example, 137°C), the mode shifts to uneven mode. In uneven mode, after turning off the rice cooking heater 10 for a certain period of time, the setting of the burn switch 23 (only for a period of time according to irJ) is performed. The rice cooking heater 10 is turned on, turned off 1llY, completes the rice cooking operation, and shifts to Ichihol!Jn mode.In the keep warm mode, the on/off operation of the keep warm heater 14 is performed to keep the rice warm to a constant temperature (
For example, the temperature is controlled to be 70°C.

The following is a normal rice cooking operation, but for example, if the temperature detected by the first thermistor 16 has already reached a predetermined value (137°C) or higher in the power control mode, it will be determined that the inner pot is empty and the subsequent operation will be performed. Skip the program step and switch to keep warm mode. In addition, if the second thermistor 17 provided on the side of the inner pot is not normal - the rice cooking operation cannot be performed according to the program, so the normal rice cooking mode in which the power of the rice cooking heater 10 is constant is executed. After starting the normal rice cooking mode, if the temperature detected by the first thermistor 16 reaches 137° C. or higher within a certain period of time, it is determined that the inner pot is empty and the mode is shifted to the keep warm mode.

The above operation will be explained in more detail according to the flowchart.

FIG. 6 shows the initial state, and when the power is turned on, an abnormality in the first thermistor 16 on the bottom of the inner pot is detected (step Sl). Abnormality detection is performed as follows. If the thermistor is disconnected, it will become a pre-resistance and will be in the same state as at low temperature, and if it is shorted, it will be low resistance and will be in the same state as at high temperature.

Therefore, in the initial state, the resistance value of the first thermistor
If the resistance value is low corresponding to the above, it is determined that the first thermistor 16 is abnormal.
Temperature is detected by the second thermistor 7 on the HIJ surface of the inner pot 4 (step S2).

If the detected temperature is 55°C or higher, the mode shifts to the heat retention mode, and if it is lower than -55°C, the timer switch 2 and rice cooking switch 1 are read. If the timer switch 2 is on, the process shifts to the timer set mode (step 53').
If the timer switch 2 is off and the rice cooking switch 1 is on, the mode shifts to preheating mode (step S4).

FIG. 7 shows an operation flowchart of the heat retention mode. The heat-retaining heater J4 is controlled so that the rice temperature reaches 70°C (step 55). If the rice cooking switch 1 is pressed during the keep-warm mode, the rice cooking is stopped (step S6). Also, the second thermistor 17 is activated during the keep-warm mode. (Step S7). Abnormality detection of the second thermistor 17 is the same as that of the first thermistor 16, but in this case, it corresponds to a high resistance value corresponding to below 20°C or above 130'CJa. Low resistance value (low resistance is considered abnormal.

A flowchart of the timer setting operation is shown in FIG.

When timer switch 2 is pressed, one set time of 30 minutes is displayed (step s11), and each time timer switch 2 is pressed, the time display is increased (incremented) in units of 30 minutes (steps 312 and 513).

Then, when the rice cooking switch 1 is pressed (step S1o>
, the timer operation is started.

Flowchart 1 of the timer operation is shown in FIG.

The elapsed time is subtracted from the set time that has been completely displayed, and the remaining time is displayed (step 515). When the remaining time reaches 0, the mode shifts to the preheating mode (step 516. If the rice cooking switch 1 is pressed during this timer mode (step 514), the timer set is canceled and the mode returns to the initial state.

Next, the rice cooking operation will be explained with reference to FIGS. 1o to 14.

For the preheating shear (Fig. 10), use
1 lights up. First, the diary 11 was written by the second Zamister 17.
Measured 1 time, less than 20℃, 20-33℃, or 3
Depending on whether the temperature is above 3°C, the rice cooking heater 10 is heated by electricity with J times of power (step 52).
0,521). Preheat for a certain period of time (for example, 6 minutes)
After reaching S, the electric power of the cooking plate heater 10 is increased to the maximum ζ, and the process shifts to the next medium heat mode (step 523.5).
24).

If the rice cooking switch 22 is pressed in this preheating mode, the rice cooking switch 22 is turned off and turned off (if the timer switch 23 is on and fS, the rice cooking operation is canceled and returns to the initial state. (Step S22→5
40,541). For this operation, if you have started cooking rice but want to cancel it for some reason, use fs doboko line fX;

Also, if the timer switch 23 is pressed when the pressed rice cooking switch 22 is pressed, the process shifts to the normal rice cooking mode (step S22→540).

541). This operation is performed during the inspection process before shipment at the factory, etc.
This is the operation realized by the present invention.

In medium patch mode (Fig. 11), LE I in Fig. 4)
32 will go down in history. If the temperature detected by the second thermistor 17 is less than 37°C, the medium cooking operation continues, but if the second thermistor 17 detects a temperature of 37°C or higher at this point, the mode shifts to normal rice cooking mode (step S25). .

During normal operation, a certain period of time [for example, 1
0 minutes], the second thermistor 17 detects 50° C. (steps 526 and 527).

However, even after a certain period of time has passed, the second thermistor 17 remains at 50.
When the temperature is not detected, it is determined that there is an abnormality in the first and second thermistors 17 and others, and the mode shifts to the normal rice cooking mode (step 526).

When @2 thermistor 17 detects 50°C in step S2'7, after a certain period of time (for example, 2 minutes) from that point,
Temperature is detected again by the second thermistor 17 (steps 528 and 529r). Then, from the rate of temperature increase over a certain period of time, it is determined whether the content is warm or not, and the amount of electricity applied to the rice cooking heater 10 is changed to the content h-1. I will become the city sword that suits you ゛) I-ko system ml
j, and the process moves to the next power control mode 1 (step 53o).

Power control mode)' (@Figure 12 L in Figure 4
I': D 33 further turns on the λ light and heats it for a certain period of time (for example, 4 minutes) by controlling the power ttt (Step 532) Under normal conditions, it will boil at this stage, but there is still water left. Therefore, the temperature detected by the first rmister 16 will never exceed the boiling point of water.If the first rmister 16 detects a temperature of 137°C or higher in this power control mode, it is determined that the inner pot is empty. Then, the process shifts to the maintenance mode (step 531).

After a certain period of time in step 332, 175 teeth, the boiling maintenance mode is switched to 1-3 and the power is controlled at 70% of the city power value.
(Step 533: In the boiling maintenance mode, L E I in FIG. 4) 34 is further lit. The temperature of the rice will rise as the water boils down and the water evaporates.
If the thermistor 16 detects a temperature higher than 137° C., the next transition is to the cramp mode (step 534).

If an abnormality occurs in the first thermistor 1- and 137°C is not detected, the system will shift to uneven mode after a certain period of time (e.g. 25 minutes) has elapsed after starting boiling maintenance mode (
step 535).

The normal rice cooking mode will be explained with reference to FIG. In this mode, D31 to D34 of No. 1'' in Fig. 4 are lit, and the power of the rice cooker heater L is set to 70% of the maximum power, and the rice is heated for a certain period of time (1), and then the mode shifts to uneven mode. (Step S37.538). In this case - after the transition to the normal rice cooking mode, a certain period of time σ1) has elapsed AiJ
It takes a certain period of time (T2
) or more, the mode shifts to the uneven mode; however, if this time is less than ゛I゛2, it is determined that the inner pot is filled with nitrogen, and the mode shifts to the warming mode (step 539). Here, the fixed time (T2) is never 13 if the inner pot is not nitrogen.
This is the time during which the temperature does not rise to 7°C.

Finally, the operation in uneven mode is shown in zt+ Figure 14.

First, after the lights L and El in Figure A4 are turned on and the power to the rice cooking heater 10 is turned off for a certain period of time (steps s5o and S51), the burn switch is turned on.
The on time is determined by determining whether the power is set to medium or light, and the rice cooking heater 1 () is energized and heated for that time (steps 552 to 554). Here L E 1) 3
5 lights up further. By adjusting the energization time, the degree of burntness can be changed. After a certain period of time, the rice cooking heater 10 is turned off and the L F, I) 37 is further turned on. Eventually the temperature detected by the second thermistor 17 reaches 7 (J°C
When it decreases to
). In the heat retention mode, only LED 33 lights up.

As described above, the present invention can increase the microcomputer to 1Iit.
In a rice cooker that has been tested, by operating the rice cooking switch and timer switch, we have made it possible to ignore the rice cooking progera and immediately recognize the rice cooking operation, so we installed a special switch for the test mode. Now, the process of checking the rice cooking operation on the 66 line, which used to take several tens of minutes, can now be carried out in just 4 to 5 minutes, and the testing process has been significantly shortened. Ta.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram explaining the present invention in detail, Fig. 2 is a schematic sectional view showing one embodiment of the invention, Fig. 3 is a main circuit diagram of one embodiment, and Fig. 4 is an embodiment. FIG. 5 is a diagram showing a panel of the control unit used, FIG. 5 is a diagram showing a rice cooking program in one embodiment, and FIGS. 6 to 14 are flowcharts showing the operation of one embodiment. 1...Rice cooking switch, 2...Timer switch, 3
. . . Programmed rice cooking operation control means, 4 . . . Timer means, 5 . Patent applicant Zojirushi Mahobin Co., Ltd. Agent
Patent Attorney Aohaku Sogai, 3 people Figure 3 Figure 4 Figure 6 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] (1) A rice cooking switch for starting and stopping the rice cooking operation, a timer switch for setting the time until the start of the rice cooking operation, a preset rice cooking program (program to perform the rice cooking operation according to the rice cooking operation), a rice cooking operation control means, and the timer. In an automatic rice cooker, the automatic rice cooker includes: a timer means for operating the programmed rice cooking operation control means after a time set by a switch has elapsed; Input the switch and timer switch signals.
An automatic rice cooker characterized by comprising a switch determination stage which selects the programmed rice cooking operation control means, the normal rice cooking operation control means, or the timer means and puts them into operation based on the combination number of these signals.