JP3234765B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker having a so-called reservation rice cooking function, which can complete a rice cooking operation at a set reservation time.

[0002]

2. Description of the Related Art A recent rice cooker is generally provided with a reservation rice cooking function for completing a rice cooking operation at a set reservation time, and there is a rice cooker having an appearance as shown in FIG. The operation unit (3) formed on the upper part of the appliance body (1) has a reservation rice cooker switch (32) and a time setting button for setting the reservation time.
(33) and (34) are provided, and the reservation time set by the buttons (33) and (34) is stored in a reservation time setting device provided in a control device (not shown). In addition, the time setting button (3
3) A reservation time display device (35) for displaying the reservation time is provided near (34).

[0003] Further, in this apparatus, a reference rice time setting for storing a rice cooking time when a rice grain having a reference rice amount (eg, a maximum rice cooking capacity) is cooked with water at a reference temperature (eg, 20 ° C) is stored as a reference required time. And a reservation time setting device for storing the reservation time set by the time setting buttons (33) and (34) are incorporated in a control device (not shown). In this device, the rice cooking operation is started at a time earlier than the reservation time set by the reservation time setting device by the reference required time, and the temperature sensor (2
The temperature in the kettle (2) detected by 1) is the rice cooking completion temperature (for example, 14
When the temperature reaches 5 ° C.), the steaming operation is performed for a predetermined time (for example, 15 minutes), and then the rice cooking operation is completed. Then, since the reference required time is set to a time required for cooking the reference rice amount with water at the reference temperature, the time required for the reference required time to elapse from the start of rice cooking, that is, the reservation time has arrived. Around the time, the rice cooking operation is completed. If the cooked rice is cooked early, a warming operation is executed to notify that cooking is completed when the reserved time comes.

[0004]

However, in the above-described conventional apparatus, the rice cooking start time is set using the fixed reference required time, despite the fact that the required rice cooking time varies depending on the temperature of the water used and the amount of rice cooked. Since the calculation is performed, the reservation time and the actual cooking completion time are easily shifted. In particular, when the rice cooking operation is completed after the reservation time, there is a big problem since a meal cannot be made at a desired time.

In recent rice cookers, so-called fuzzy control is performed so that the required rice cooking time is substantially constant. However, even in such a rice cooker, for example, in the case of a gas rice cooker, the supply gas pressure is low. In addition, when the temperature of the water to be used is extremely low, the rise time until the inside of the pot rises to the boiling temperature may be longer than the set time, and the cooking completion time may be later than the reservation time. Therefore, in the fuzzy control type as well, even if the supply gas pressure is low and the water temperature is extremely low, the rice cooking time is estimated slightly longer so that rice can be completed at the reservation time, and the reservation time is Normally, the cooked rice is cooked slightly earlier and the operation shifts to the warming operation.

The present invention has been made in view of the above-mentioned circumstances. "A temperature sensor for detecting the temperature in a pot and a required time for cooking rice when the rice is cooked using water having a reference temperature are defined as a first reference required time. A first reference required time setting device for storing, a reservation time setting device for setting a reservation time for reserved rice cooking, and a second reference required time setting device for storing the required rice cooking time for the reference rice amount as a second reference required time. When the reserved rice cooker switch is operated, the rice cooking operation is started from the rice cook start time determined based on the difference between the reserved time and the first reference required time and the difference between the reserved time and the second reference required time. When the temperature inside the pot detected by the temperature sensor reaches the temperature at which the rice is cooked, the rice cooker ends the rice cooking operation. Cooking rice As its object to reduce the deviation of the completion time.

[0007]

[0008]

According to a first aspect of the present invention, there is provided a method for cooking rice cooked by a temperature sensor after turning on a reservation rice cooker switch and a reference temperature. Means for performing a first correction for advancing or delaying the rice cooking start time according to the amount of change in the temperature of the temperature sensor by heating the kettle after the temperature sensor detects the temperature in the kettle for the first correction. Rice rice determination temperature gradient (G), which is the temporal change rate of the detected temperature, and rice cooked rice amount determination means for determining the amount of rice grains to cook based on the rice volume determination temperature gradient (G), and the rice cooking Means for performing a second correction for further advancing or delaying the rice cooking start time after the first correction in accordance with the amount of change in the required rice cooking time resulting from the difference between the amount of cooked rice determined by the rice amount determination means and the reference rice amount. Rice cooked at the corrected rice cook start time To start the work, "that is.

The above technical means operates as follows. When the reserved rice cooker switch is operated, rice cooking is started from the change in the required rice cook time based on the difference between the water temperature in the pot detected by the temperature sensor after the operation and the reference temperature (water temperature when cooked rice is cooked in the reference required time). The operation of correcting the time is executed by means for performing the first correction. That is, since the required rice cooking time becomes shorter when the water temperature becomes higher, in such a case, the means for performing the first correction executes the correction for delaying the rice cooking start time, and conversely, when the water temperature becomes lower, the required rice cooking time becomes longer. Therefore, in such a case, the first correction for advancing the rice cooking start time is performed.

[0010]

According to the above-mentioned technical means, the pot is heated after the temperature sensor detects the temperature in the pot for the first correction, whereby the rate of change with time of the detected temperature of the temperature sensor is obtained. The rice amount determination temperature gradient (G) is determined. Then, since the rice amount determination temperature gradient (G) and the amount of cooked rice have a relationship in which one increases and the other decreases, the amount of cooked rice can be determined by this. Then, the rice cooking start time (already corrected by the first correction) is further corrected by the second correction unit from the amount of change in the required rice cooking time based on the amount of cooked rice (second correction). That is, if the amount of cooked rice increases, the time required for rice cooking becomes longer. In such a case, the correction to advance the rice cooking start time is executed by the means for performing the second correction, and conversely, if the amount of cooked rice decreases, the time required for rice cooking becomes shorter. In such a case, the correction that delays the rice cooking start time is executed by the second correction unit.

[0012]

As described above, according to the present invention,
Since the rice cook start time is corrected to be advanced or delayed according to the temperature change of the water to be used and the amount of cooked rice, the difference between the reservation time and the actual cooked rice completion time due to the change in the water temperature and the change in the amount of cooked rice. Becomes smaller.

[0013]

Next, an embodiment of the present invention will be described. As described above, the rice cooker switch (32) and the time setting buttons (33) and (34) are provided on the operation unit (3) of the appliance body (1). (36) Ordinary rice cooker switch (31) to be turned on when starting rice cooker operation immediately, and further stop switch (38)
Is provided.

The outputs of the switches and the temperature sensor (21) for detecting the temperature inside the shuttle (2) are applied to a control circuit (5) incorporating a microcomputer as shown in FIG. The output of the reservation time setting device (37) for storing the reservation time set by the time setting buttons (33) and (34) is applied to the control circuit (5) and the reservation time display device (35) to make the reservation. Time display device
In (35), the reservation time is displayed. Further, the output of the control circuit (5) is applied to a gas valve (42) inserted in the gas circuit to the gas burner (4).

The microcomputer incorporated in the control circuit (5) stores a control program having contents as shown in the flowcharts of FIGS. 3 and 4. Hereinafter, the operation of the rice cooker according to the present embodiment will be described. Will be described with reference to these drawings. When a power plug (not shown) is connected, it is monitored that the reserved rice cooker switch (32), the normal rice cooker switch (31) and the heat insulation switch (36) are turned on (step (71) in FIG. 3).
~ (73)).

When the operation of the reservation rice cooker switch (32) is confirmed, the control operation shifts from step (71) to step (74), and the reservation time (A) stored in the reservation time setting device (37) is reset. It is stored in the reserved time memory (M1) in the microcomputer. Also, the temperature detected by the temperature sensor (21) (water temperature in the pot (2))
(Equivalent to (B)) the temperature memory in the microcomputer
(M2) (see step (75)).

Next, in steps (76) to (80), the correction time (C) is determined so that the water temperature (B) increases as the water temperature (B) decreases. That is, when the water temperature (B) is 10 ° C. or less, the correction time (C) is set to “6 minutes” (step (7)).
6) (78)) If the water temperature (B) is higher than 10 ° C and lower than 15 ° C, the correction time (C) is set to “3 minutes” (step (77)).
(79)) If the water temperature (B) exceeds 15 ° C., the correction time (C) is set to “0” (steps (77) and (8)).
0)).

Next, the correction time (C) and the first reference time (the time required for rice cooking when 1 liter of rice grains are cooked with water at 20 ° C., which is 45 minutes in this embodiment) Set the required rice cooking time (D) from (set).
That is, the correction time (C) is added to the first reference required time to determine the required rice cooking time (D) (step (8)).
1)). Therefore, the required rice cooking time is corrected based on the change in the temperature of the water to be used, whereby the required rice cooking time (D) is subtracted from the reservation time (A) in step (93) of FIG. The rice cooking start time (E) is also corrected based on the change in the water temperature. Therefore, in this embodiment, steps (76) to (80) for determining the correction time (C) based on the water temperature (B), and the rice cooking time (D) is calculated based on the correction time (C). (81) and a step (9) of calculating the rice cooking start time (E) using the rice cooking time (D).
The functional unit in the microcomputer that executes the step 3) corresponds to the means for performing the first correction of the first aspect. Further, the water temperature of 20 ° C., which is an element for determining the first reference required time, corresponds to the reference temperature of the first aspect of the present invention.
The liter of rice corresponds to the reference amount of rice according to the first aspect of the present invention. Further, a memory section in the microcomputer for storing the first reference required time set at 45 minutes corresponds to the first reference required time setting device of the first aspect of the present invention.

Next, from step (82) to step (9) in FIG.
In 3), the rice cooking start time (E) is corrected based on the amount of cooked rice. That is, first, in steps (82), (83) and (84), the gas burner (4) is burned for one minute, and then the temperature sensor (21)
The memory temperature (M3) in the microcomputer is stored as the temperature after heating (F) as a temperature after heating (F) (step (85)), and the temperature after heating (F) and the water temperature detected before combustion of the gas burner (4) are stored.
The difference of (B) is stored as a rice amount determination temperature gradient (G) (step (86)). Then, the temperature gradient (G) for determining the amount of rice and the amount of cooked rice have a relationship in which one increases and the other decreases.
That is, as the amount of cooked rice increases, the temperature gradient (G) for judging rice amount decreases, and as the amount of cooked rice decreases, the temperature gradient (G) for judging rice amount increases.

Next, steps (87) to (92) in FIG.
Use to correct the rice cooking time (D) based on the amount of cooked rice. That is,
If the rice amount determination temperature gradient (G) is 4 degrees or more, the correction time (H) is set to "6 minutes" (steps (87) and (91)), and the rice amount determination temperature gradient (G) is 4 degrees. If it is less than 2 deg and less, set the correction time (H) to “3 minutes” (steps (88) (9)
0)) Further, if the rice amount determination temperature gradient (G) is less than 2 deg, the correction time (H) is set to “0 minutes”. And
The value obtained by adding the correction time (H) and the required rice cooking time (D) is stored again as the required rice cooking time (D) (step (9)
2)). Therefore, in this embodiment, the required rice cooking time (D) before re-storing corresponds to the second reference required time according to the first aspect of the present invention. A function unit in the microcomputer for storing the required rice cooking time (D) before the re-storage is performed.
Corresponds to the second required time setting device of the invention. Then, in step (93), the rice cook start time (E) = reservation time (A) -required rice cook time (D) is calculated, whereby the rice cook start time (E) is corrected based on the amount of cooked rice. Therefore, in this embodiment, the functional unit in the microcomputer for executing the steps (75), (82) to (86) necessary for determining the rice amount determination temperature gradient (G) is described in claim 1. Corresponds to the rice cooked rice amount determining means of the invention. Further, the correction time (H) is determined according to the magnitude of the rice amount determination temperature gradient (G), and the rice cooking start time (E) is calculated based on the correction time (H) and the rice cooking time (D). The functional unit in the microcomputer which executes the steps (87) to (93) corresponds to the means for performing the second correction according to the first aspect of the present invention.

Next, when the rice cooking start time (E) is calculated, the arrival of the rice cooking start time (E) is monitored using a built-in timer of the microcomputer (step (94)).
When the rice cooking start time (E) comes, the gas burner (4) is burned in step (95). Then, when the temperature in the pot detected by the temperature sensor (21) reaches 145 ° C., which is the temperature at which the rice is cooked, the gas burner (4) is maintained in a fire extinguishing state in step (97), and then the steaming operation of the cooked rice is performed in step (98). For a fixed time (for example, 15 minutes). When the steaming operation is completed, in step (99), a rice cooking completion indicator lamp (not shown) is turned on to display rice cooking completion, and then a stop switch (3)
Until 8) is turned on, the heat retention heater (25) is operated to continue the heat retention operation (steps (100) and (101)).

As described above, in the rice cooker according to the above embodiment, the rice cook start time depends on the amount of cooked rice and the temperature of the water used.
Since (E) is corrected, the difference between the actual cooked rice completion time displayed in step (99) and the reserved time set by the reserved time setting device (37) is reduced. Step (7) in FIG.
When the operation of the normal rice cooker switch (31) is confirmed when the step (2) is executed, a pre-cooking step of heating the inside of the pot (2) to a predetermined temperature (eg, 40 ° C.) for a predetermined time (eg, 10 minutes) is executed. (Step (721)), and then the control operation is moved to Step (95) in FIG. 4 in which the gas burner (4) is burned. or,
When the operation of the heat retention switch (36) can be confirmed in step (73) of FIG. 3, the control operation is shifted to step (100) of FIG. 4 to cause the heat retention heater (25) to generate heat, thereby executing the heat retention operation. Is done.

In the above embodiment, the required rice cooking time (D) is once corrected according to the amount of cooked rice and the temperature of the water to be used.
Rice cooking start time based on the corrected rice cooking time (D)
(E) was corrected.
Correction time (C) obtained in (80) and Step (87)-Step (9
The built-in timer of the microcomputer may be advanced by the sum of the correction time (H) obtained in 1), or the correction time (C) from the reserved cooking time set by the reservation time setting device (37)
(H) may be subtracted. Further, after subtracting 45 minutes as a reference required time from the output of the reservation time setting device (37), the correction time (C) (H) may be subtracted from the subtraction result. In any of these cases, as a result, the rice cooking start time is corrected based on the amount of cooked rice and the temperature of the water used.

In the above embodiment, the amount of cooked rice is determined based on the temperature gradient of the temperature in the pot (2) accompanying the heating of the pot (2). 2) A weighing machine for measuring the weight of 2) may be provided, and the amount of cooked rice may be determined by the weighing machine. Further, a reference required time is set in advance based on a reference water temperature (for example, 5 ° C.) lower than the above embodiment, and a correction time (C) determined based on the temperature of the water to be used
Is subtracted from the reference required time to shorten the required cooking time,
A correction may be made to delay the rice cooking start time based on the corrected rice cooking required time.

Furthermore, the reference required time is set based on a larger reference rice amount (eg, the maximum rice cooking capacity that can be cooked) than in the above embodiment, and the correction time determined based on the rice cooked rice amount is set.
(H) may be subtracted from the reference required time to shorten the required rice cooking time, thereby making a correction to delay the rice cooking start time in the same manner as described above.

[Brief description of the drawings]

[Fig. 1] External view of the instrument body (1)

FIG. 2 is a control circuit diagram of the rice cooker according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating a control program stored in a microcomputer of the control circuit (5).

FIG. 4 is a flowchart illustrating a control program stored in a microcomputer of the control circuit (5).

[Explanation of symbols]

 (1) ・ ・ ・ Equipment body (3) ・ ・ ・ Operation part (31) ・ ・ ・ Normal rice cooker switch (32) ・ ・ ・ Reserved rice cooker switch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-166718 (JP, A) JP-A-60-48714 (JP, A) JP-A-2-305515 (JP, A) JP-A-7- 8189 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A47J 27/00 109

Claims (1)

(57) [Claims] 1. A temperature sensor for detecting a temperature in a pot, a first reference required time setting device for storing a required rice cooking time when the rice is cooked using water at a reference temperature as a first reference required time, and a reserved rice cooking. A reservation time setting device for setting a reservation time for cooking, and a second reference required time setting device for storing the required rice cooking time for the reference rice amount as a second reference required time, when the reserved rice cooking switch is operated. Above reservation time and 1st
The rice cooking operation is started from the rice cooking start time determined based on the difference in the reference required time and the difference between the reservation time and the second reference required time, and the rice is cooked when the temperature in the pot detected by the temperature sensor reaches the rice cooking complete temperature. In the rice cooker whose operation is to be ended, a first correction is made to advance or delay the rice cooking start time according to the amount of change in the required rice cooking time caused by the difference between the reference temperature and the temperature detected by the temperature sensor after the reservation rice cooker switch is turned on. Means for heating the kettle after the temperature sensor detects the temperature in the kettle for the first correction, thereby producing a temperature gradient for rice quantity determination as a temporal change rate of the detected temperature of the temperature sensor.
(G), the rice rice amount determination means for determining the amount of rice grains to cook based on the rice amount determination temperature gradient (G), rice cooked rice amount and the reference rice amount determined by the rice rice amount determination means Means for performing a second correction for further advancing or delaying the rice cooking start time after the first correction in accordance with the amount of change in the required rice cooking time due to the difference in rice cooking, and starting the rice cooking operation at the corrected rice cooking start time Rice cooker which was made to let.