JPS59129037A - Rice cooker equipped with empty cooking preventing means - 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 a rice cooker, and more particularly to a rice cooker using a micro combi coater as a control circuit.

BACKGROUND ART In a conventional rice cooker with a built-in microcomputer, by setting a predetermined rice cooking program in a ROM (read only memory) in advance, it is possible to automatically perform a rice cooking operation according to the program. However, in such a rice cooker, if the inner pot is empty and the rice cooking operation is accidentally started, the rice cooker operates according to the same program as when normally cooking rice. As a result, the temperature of various parts may rise beyond the specified limits, and there is a risk that accidents such as melting of temperature fuses may occur. Therefore, in such a rice cooker, it is necessary to provide some kind of dry-cooking prevention means or dry-cooking detection means.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a rice cooker with a built-in micro combi coater that is equipped with a means for preventing dry rice cooking.

The present invention is capable of controlling the temperature of the inner pot within a certain period of time after the start of the rice cooking operation or until reaching the predetermined rice cooking mode, even though the temperature of the inner pot cannot reach the predetermined temperature if there is food in the rice cooker. When this is reached, the inner pot is determined to be empty, and appropriate measures are taken to achieve the above objective.

”Ai Figure 1 schematically shows the structure of the present invention.

1 is a rice cooking heater provided to heat the bottom surface of the inner pot 2 of the rice cooker A via an electric heating member 3; 4 is a heat-retaining heater;
This heat-retaining heater 4 is provided so as to heat the upper side surface of the inner pot 2 via an external grower 5.

Reference numeral 6 denotes temperature detection means including a thermistor (hereinafter referred to as a first thermistor) 6-1 as an example of a temperature measuring element, and the first thermistor 6-1 is provided so as to be in contact with the bottom surface of the inner pot 2. Reference numeral 7 denotes a rice cooking mode setting means which stores a rice cooking mode program using temperature and time as parameters, and is usually constituted by a ROM. 8 is a rice cooking mode control means which inputs the temperature signal from the temperature detection means 6 and the same amount signal from the time measurement means 9, and controls the rice cooking heater 1 and the warming heater 4 according to the rice cooking mode program set in the rice cooking mode setting means 7. It outputs a signal that controls the on/off operation of the rice cooker heater 1 and the amount of electricity supplied to the rice cooking heater 1. Reference numeral 1o denotes heater energization amount control means, which inputs a signal from the rice cooking mode control means 8 and determines the amount of energization to the rice cooking heater 1. Reference numeral 11 denotes a switch means which inputs a signal from the rice cooking mode control means 8 and switches the rice cooking heater 1.
and controls the on/off operation of energization to the heat-retaining heater 4.

In the present invention, if a temperature signal higher than a predetermined temperature is sent from the temperature detection means 6 to the rice cooking mode control means 8 before reaching a predetermined rice cooking mode or within a certain period of time, a signal is sent from the rice cooking mode control means 8 to the switch means 11. When the rice is sent out, the power supply to the rice cooking heater 1 is turned off, and the power supply to the heat retention heater 4 is controlled to shift to the heat retention mode.

In addition, in a preferred embodiment of the present invention, as shown in FIG. 1, a thermistor (hereinafter referred to as a second nermistor) 12-1 for detecting the side temperature of the inner w42 is further included. A temperature detection means 12 and a rice cooking power determination means 13 are provided.

The rice cooking power determining means 13 determines the amount of content in the inner pot 2 by measuring the rate of temperature increase over a certain period of time from the preparation detecting means 12, and controls the amount of heater energization so as to set the amount of heater energization according to the amount of content. A signal is sent to the means 10. Further, the heater energization amount control means 10 inputs a signal from the temperature detection means 12 at the time of starting rice cooking, and if the starting temperature is high (beep), the heater energization amount is decreased; Furthermore, in the initial state (when the power is turned on), the rice cooking mode control means 8 inputs a signal from the temperature detection means 12, and if the temperature w4 is 55° C. or higher, the rice cooking heater is turned on. It is also possible to perform J:connect control in which the power supply of 1 is turned off and the mode is shifted to the heat retention mode.

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

20 is a control unit l~ installed on the outer body of the rice cooker,
A microcomputer 21 is incorporated therein as a control circuit for realizing each means shown in FIG. 22
-24 are various switches for operating this micro convenience store 1--921.

The first thermistor 6-1 and the 24th no-mistor 12-1
J5 are brought into contact with the bottom and side surfaces of the inner pot 2 by the pressing force of the spring, and both thermistors 6-1.42-
The detection signal No. 2 is wired to be input to the microcomputer 21. 25 is a power supply circuit which receives a control signal from the microgo 1 pump 21 and energizes the rice cooking heater 1 and the warming heater 4. It is buried in the heat transfer part +J3 that contacts the bottom of the pot. The heat-retaining heater 4 is configured such that heat is transferred to the inner pot 2 via the outer container 5.
It is provided surrounding the upper side surface of the outer container 5. 26
There is a lid C'' on the inner pot.Although it is omitted in the figure, there is a lid C'' on the outer pot 5.
A heat insulating material is filled around the lid 2G for heat retention, and a known pressure regulating device can also be provided on the lid 2G.

19 is a microswitch that detects the presence or absence of the inner pot 2, and if the inner pot 2 is present, it turns on and turns on the power supply circuit 25; until the inner pot 2 is placed, the power supply circuit 25 is turned off and dry cooking is performed. It is prevented.

In this embodiment, the electric circuit system directly related to the operation of the rice cooking heater 1 is not shown in FIG. The 11th length mister 6-1 on the bottom side of the inner pot and the second thermistor 12-1 on the side surface are provided between the power supply Vdd and the ground via resistors R, 4, and R2, respectively, and the respective detection signals is the microphone []
2 to the A/[) converter input port of computer 21
, and is converted into a digital signal.

The switch 22 is a rice cooking switch for operating the rice cooking operation, and the switch 23 is a timer switch for the timer Z 1- since this embodiment has a timer function as described later. Signals from the respective switches 27 and 23 are also input manually to the microcomputer 21.

The microcomputer 21 sends an on/on signal to the driver 27, thereby controlling the signals of the 1~Riatsu 928 through the driver 27. The rice cooking heater 1 is connected to an AC power source 29 via its i-light connector 28, and is controlled to be turned on and off.

In this embodiment, the rice cooking heater 1 is The lf suspension is controlled by the duty ratio of the on-time controlled via 1 to 28. In other words, microcomputer 2
1 is the first thermistor 6-1 and the second reamister 12-
When the temperature signal from 1 is input, the driver 27 outputs an ON signal for an appropriate amount of time at a fixed time interval (for example, 15 seconds) so that the appropriate amount of electricity is applied according to the set rice cooking mode program. By 1-Liac 2
8 to turn on.

Since the rice cooking heater 1 is energized and heated only during the time when the triac 28 is on, the desired energization (rice cooking power) can be achieved by changing the time during which it is energized.

FIG. 4 shows the panels of the control units 1 to 20 used in this embodiment. The switches that can be operated by the operator include the rice cooking switch 22 for starting and starting the rice cooking operation.
There are three switches: a timer switch 23 that allows you to set the time until the start of the rice cooking operation, and a burnt switch 24 that allows you to adjust the degree of burnt rice according to your preference. 30 is a display panel that displays the progress of rice cooking as it progresses according to the program, and is provided with diodes 31 to 38 for each step. The lights are turned on one after another.

41 and 42 are time display panels that display the remaining time until the rice cooking operation starts when the timer function 1 to 1 is set by the timer switch 23, and 40 indicates the time, with 7 segments of 1-1 digits. 3l) element, 41 is the number 3
This is a surface emitting element on which 0 (minutes) is displayed.

Roundness Next, the operation of one embodiment will be explained.

In FIG. 5, -actual fJf! The relationship between the rice cooking mode program executed in example i and the bottom temperature of the inner pot is shown.

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 1 to the maximum. This stage is called middle bappa mode. Soshi C 2nd - Lee Mister 1
When the detected temperature of 2 to 1 exceeds 50 DEG C., the content is determined from the temperature gradient as described above, and the power supply is controlled in accordance with the amount of content. How to control power at this stage 7-1.

In this mode, it will boil over soon! Spell l. Power control 1 - Controls the rice cooking heater power at a predetermined rate (
For example, maintain the boiling point by avoiding the drop to 70%. This stage is called the boiling l1gM holding mode.

Continue boiling (when the water in the boiler runs out, the temperature will rise to a specified temperature, e.g. 137°C).
), it shifts to uneven mode.

In the uneven mode, after the rice cooking heater 1 is turned off for a certain period of time, the rice cooking heater 1 is turned on for a time corresponding to the setting value of the burn switch 24, and then turned off again to complete the rice cooking operation and shift to the warming mode. . In the keep warm mode 1-, the rice temperature is kept at a constant temperature (for example, 7
0°C).

The above is a normal rice cooking operation, but for example, if the temperature detected by the first thermistor 6-1 has already reached a predetermined value (737°C) or higher in the electric power controller 1 heating mode, it is determined that the inner pot is empty. Then, the program skips the subsequent steps and shifts to the moisturizing mode.

Furthermore, if the second thermistor 12-1 installed on the side of the inner pot is not normal, the rice cooking operation according to the program cannot be performed, so the rice cooking mode in which the power of the rice cooking heater 1 is constant is executed. In that case, if the temperature detected by the first thermistor 6-1 reaches 137°C or higher within a certain period of time after starting the normal rice cooking mode, it will be determined that the inner pot is empty and the mode will shift to the keep warm mode. .

The above operation will be explained in more detail according to the flow v-h.

FIG. 6 shows the initial state, and when the power is turned on, first the temperature of the first thermistor 6-1 on the bottom of the inner pot is detected (step S1). Abnormality detection is performed as follows. If the thermistor is disconnected, it will have high 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 d-3, if the resistance value of the first thermistor 6-1 is a high resistance value corresponding to 120°C or less or a low resistance value corresponding to 150°C or more, the first thermistor 6-1 -1 is determined to be abnormal, and the abnormality is notified. Next, the second thermistor 12- on the side of the inner pot
1, temperature detection is performed (step s2). If the detected temperature is 55°C or higher, it will shift to the heat retention mode and 55°C.
If it is less than C, the timer switch 23 and rice cooking switch 22 are read. If the timer switch 23 is on, the transition to timer cella 1~mode occurs (step S3);
When the timer set switch 23 is off, the rice cooking switch 22 is turned off.
is on, shifts to preheating mode/\ (step s4
).

FIG. 7 shows an operation flowchart of the heat retention mode. The insulating heater 4 is controlled so that the temperature of the rice becomes 70'C (step s5). When the rice cooking switch 22 is pressed during the heat retention mode, the rice cooker is stopped (step s6).

[Step s7 to detect an abnormality in the second thermistor 12-1 even during the heat retention mode. 21st No Mister 12-
1 abnormality detection is the same as the case of the first thermistor 6-1, but in this case, high resistance value corresponding to 20℃ or less or 7
If the resistance value is low and corresponds to 30-℃ or higher, it is determined that there is an abnormality.

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

When the timer switch 23 is pressed, the set time of 30 minutes is displayed (step 511), and the timer switch 23 is pressed.
Each time is pressed, the time display is incremented in units of 30 minutes (increment 1 -). (Steps s12.s13)
.

Then, when the rice cooking switch 22 is pressed, step s10
), the timer operation is started.

A flowchart of the timer operation is shown in FIG.

The elapsed time is subtracted from the displayed set patent application, and the remaining time is displayed (step 515). When the remaining time reaches O, the process shifts to preheating mode (step 316). When the rice cooking switch 22 is pressed during this timer mode (step s14), the timer is released and the process returns to the initial state.

Next, the rice cooking operation will be explained with reference to FIGS. 10 to 14.

In the preheating mode (Fig. 10), first the second thermistor 12-
Measure the inner pot temperature according to step 1, below 20℃, 20-33℃
, or over 33°C, the rice cooking heater 1 is energized and heated with appropriate electric power (steps s20 and s21). After preheating for a certain period of time (for example, 6 minutes), the electric power of the rice cooking heater 1 is increased to the maximum, and the process shifts to the next medium-bopper mode (step s23.
s24).

If the rice cooking switch 22 is pressed in this preheating mode, the timer switch 23 will not be on when the rice cooking switch 22 is released and turned off (the rice cooking operation will be canceled and the initial state will return). Step s22→s40.s
41). This operation is performed when you have started cooking rice but want to stop it at the end of the cooking process. Furthermore, when the pressed rice cooking switch 22 is released, if the timer switch 23 is pressed, the mode shifts to the normal rice cooking mode (step s22→
s40. s41). This operation is performed in an inspection process before shipment at a factory.

Middle pappa mode (in Fig. 11, second thermistor 12-
If the detected temperature of the second thermistor 12-1 is less than 37°C, the middle patter operation will continue, but if the detected temperature of the second thermistor 12-1 is lower than 37°C at this point.
If the temperature is detected above ℃, it will switch to normal rice cooking mode (
Step 525).

During normal operation, a certain period of time (for example, 1
Thermistor 12-1 detects 50°C within 0 minutes.Step s26. s27).

However, if the second thermistor 12-1 does not detect 50°C even after a certain period of time has elapsed, it is determined that there is an abnormality in the second thermistor 12-1 or other components, and the mode shifts to normal rice cooking mode (
step 826).

When the second thermistor 12-1 detects 50°C in step s27, the second thermistor 12-1 detects the temperature again after a certain period of time (for example, 2 minutes) from that point (
Step s28. s29). Then, the content M is determined based on the rate of temperature rise between this fixed amount, and the amount of electricity supplied to the rice cooking heater 1 is controlled to be a value corresponding to the amount of content, and the next power controller is switched to the roll mode. The process moves on (step s30).

In the power control mode (FIG. 12), electricity is heated for a certain period of time (for example, 4 minutes) using controlled electricity (step 532). Under normal conditions, a boil will form at this stage, but
Since water still remains, the temperature detected by the first thermistor 6-1 does not exceed the boiling point of water. If the first thermistor 6-1 detects a temperature of 137°C or higher in this power control mode, it is determined that the inner pot is empty, and the process shifts to the heat retention mode (step s31).

After a certain period of time in step s32r has passed, the boiling maintenance mode is entered and the power is reduced to 10% of the control power value (step 533). When the boiling is completed and the water content disappears, the temperature of the rice rises, so if the first thermistor 6-1 detects a temperature of 137°C or higher, the next transition is to the uneven mode (step 534). If an abnormality occurs in the first thermistor 6-1 and 137° C. is not detected, the process shifts to the uneven mode after a certain period of time (for example, 25 minutes) has elapsed after starting the boiling maintenance mode (step 535).

The normal rice cooking mode will be explained in FIG. 13. In this mode, the electric power applied to the rice cooking heater 1 is set to 70% of the maximum electric power, and the rice is heated for a certain period of time (1'+), and then the process shifts to the uneven mode.Step s37 ．． s3.9>.

In this case, after switching to normal rice cooking mode,
'+) The detected temperature of the first thermistor 6-1 is 13
When 7°C is detected, if the time until 137°C is detected is longer than a certain time (T2), it will shift to uneven mode, but if this time is less than T2, the inner pot is empty. It is determined that
). Here, the fixed time (° [2)] is the time during which the temperature never rises to 137°C unless the inner pot is empty.

Finally, the operation in uneven mode is shown in FIG.

After turning off the electricity to the rice cooking heater 1 for a certain period of time (steps s50 and s51), the on period 114 is determined according to whether the J5 burn switch is set to light, medium, or light, and the electricity is turned on to the rice cooking heater 1 for that period. Heating string (steps s52 to 554). By adjusting the current application time mj M, the degree of burntness is changed. After a certain period of time, the rice cooking heater 1 is turned off and the mode shifts to the moisturizing mode (step 55).
5).

Of course, as described above, the present invention is equipped with a microcomputer.
In a rice cooker, if the temperature of the inner pot rises above a predetermined temperature within a certain period of time or in a predetermined mode after the rice cooking operation has started, the inner pot will be determined to be empty and the system will immediately switch to the keep warm mode. With this structure, it is now possible to easily create a rice cooker that can prevent dry cooking.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram explaining the present invention in detail, Fig. 2 is a schematic cross-sectional fj diagram showing one embodiment of the invention, Fig. 3 is a main circuit diagram of one embodiment, and Fig. 4 is an embodiment. 5 is a diagram showing a rice cooking program in one embodiment, and FIGS. 6 to 14 are flowcharts 1 to 14 showing the operation of one embodiment. - 1... Rice cooking heater, 2... Inner pot, 4... Heat retention heater, 6, 12... Temperature detection means, 6
-1.12-1... Thermistor, 7... Rice cooking mode setting means, 8... Rice cooking mode control means, 9... Timing means, 10... Heater energization amount control means, 11... Switching means, 21...Micro combi coater. Patent Applicant Zojirushi Mahobin Co., Ltd. Patent Attorney Aoyama 3 persons Fig. 1Δ Fig. 2 Fig. 3 Fig. 4 Fig. 5'' ]l Fig. 6 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Figure 12 Figure 13 Figure 614 Procedural amendment (1. Illusion J. Display of the case. 1982 Patent Application No. 005097. 2. Name of the invention. Rice cooker equipped with dry cooking prevention means. 3. Relationship with the person making the amendment. Patent application. Person 4, Agent Address: Honmachi Building, 2-10 Honmachi, Higashi-ku, Osaka City, Osaka Name: Patent Attorney (6214) Aoyama Aoyama and 3 others 5: Date of amendment order: Voluntary 6 Subject of amendment: Details of the invention in the specification Explanation column°7.
Contents of the amendment (]) Specification, page 42, line 2o, "same program" is corrected to "same program." (2) Correct ``-2'' in ``6 Negative 15 Line 1'' to ``-1''. (3) On page 8, line 19, the phrase "in action" is corrected to read "one action." (71) Same page 9] In the 9th line, it says [Surface emitting element 1] [-
surface emitting device]. (5) Same] In the second line of page 2, the words 1 and 2 are corrected to read ``abnormal.'' (6) Page 15, line 7, F (Fig. 11), replace it with 1 (1st
Figure 1)”. (Ma) On the 15th negative line 10, correct the phrase ``-1's'' to ``-1?'' (8) On the 15th negative 10th line, the word ``after'' is 1-transferred.''
I am corrected.

Claims (1)

[Scope of Claims] 1) Temperature detection means including a temperature measuring element provided so as to be in contact with the bottom surface of the inner pot, a rice cooking heater provided on the bottom surface of the inner pot, and a heat retention heater that heats the inner pot from the side. A rice cooking mode setting means that stores a rice cooking mode, a sub-time means, a salt reward signal from the humidity detection means and a time signal from the trimming means are inputted, and the rice cooking mode is set according to the rice cooking mode program of the rice cooking mode setting means. A rice cooking mode control means for outputting a signal for controlling the on/off operation of the rice cooking heater and the heat retention heater and the amount of electricity applied to the rice cooking heater; and a rice cooking mode control means for outputting a signal for controlling the on/off operation of the rice cooking heater and the heat retention heater, and the amount of electricity applied to the rice cooking heater by inputting the signal from the rice cooking mode control means. and a switch means that inputs a signal from the rice cooking mode control means to control the on/off operation of energization to the rice cooking heater and the heat-retaining heater. If the temperature detected by the means rises above a predetermined temperature for a certain period of time or before reaching the predetermined rice cooking mode, the electricity to the rice cooking heater is cut off and the rice cooker shifts to the heat retention mode. Rice cooker equipped with preventive measures.