JP6774783B2 - rice cooker - Google Patents

Description

The present invention relates to a rice cooker. In particular, the present invention relates to a rice cooker capable of specifying the degree of charring of cooked rice at the time of cooking.

Conventionally, a rice cooker that heats the rice cooker and a control unit that controls the rice cooker are provided, and a pre-cooking process of impregnating rice grains with water, a main cooking process of evaporating the water in the rice cooker, and a rice cooker A rice cooker is known in which a cooking process of heating the inside to a predetermined cooking temperature and a steaming process of steaming the cooked rice are performed. When the cooked rice is browned with this type of rice cooker, the cooking temperature in the cooking process is generally set to be higher than that when the cooked rice is not browned.

However, since the water evaporation temperature at which the water evaporates in the main cooking process differs depending on the type and quality of rice, etc., if a single cooking temperature is set for the same level of browning, the water content in the main cooking process The temperature difference between the evaporation temperature and the cooking temperature in the cooking process is different. As a result, there may be excess or deficiency in the heating of cooked rice in the cooking process, and the desired degree of charring may not be obtained. From the above viewpoint, the applicant has previously proposed to set the temperature obtained by adding the predetermined correction temperature ΔT set according to the browning level to the water evaporation temperature as the cooking temperature in the cooking process ( For example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-61649

FIG. 4 shows a temperature change of the detected temperature when the standard browning level “0” is specified using a household rice cooker. The rice cooker for home use has a small rice cooker, and the amount of rice cooked is small. Therefore, when the cooked rice begins to be charred, the ratio of the charred portion to the total amount of cooked rice increases, and the temperature change of the cooked rice in the cooking process greatly appears in the temperature of the rice cooker. Therefore, as in Patent Document 1, by increasing or decreasing the correction temperature ΔT for setting the cooked temperature, the degree of charring of cooked rice can be finely controlled at any level of strengthening and weakening.

However, a large rice cooker is used in a commercial rice cooker, and the amount of rice cooked increases. Therefore, even if the cooked rice is partially charred, the temperature change of the whole is small, and if the cooked rice is heated to the extent that the temperature change appears, the cooked rice tends to be scorched in the cooking process. When a stronger browning level is specified, the temperature difference between the water evaporation temperature and the cooking temperature becomes large, so it is possible to control the degree of charring by setting the correction temperature ΔT, but the weaker browning When the level is specified, even if the same browning level is used, the temperature difference between the water evaporation temperature and the cooked temperature is smaller in the large rice cooker as described above than in the small rice cooker, so the browning level due to the correction temperature ΔT Difficult to control. In particular, when a large rice cooker is used to cook a small amount of cooked rice with a degree of charring that does not cause charring, it is necessary to finish heating before a temperature change appears in the cooking process. Therefore, in such a rice cooker, there is a problem that the degree of burning cannot be controlled because the correction temperature ΔT as in Patent Document 1 cannot be set.

The present invention solves the above problems, and an object of the present invention is to provide a rice cooker capable of cooking cooked rice in a desired degree of charring designated by a charring level designation unit.

The present invention
A rice cooker that heats the rice cooker and
A temperature detector that detects the temperature inside the rice cooker or at the bottom of the rice cooker,
Predetermined standard browning level and browning level,及beauty specifiable browning levels weakening than standard browning level browning level specifying unit also stronger than normal browning level,
Equipped with a control unit that controls the operation of the rice cooker
In a rice cooker that performs a cooking process that heats the cooked rice so that the brown rice specified by the browning level designation section is attached.
When a stronger browning level is specified by the browning level designation unit , the control unit designates it as the cooking judgment reference temperature when the detection temperature detected by the temperature detecting unit in the cooking process reaches the predetermined cooking judgment reference temperature. Only the cooking temperature, which is the sum of the predetermined correction temperature ΔT set according to the strong browning level, is set as the cooking condition.
When a browning level that is weaker than the standard browning level is specified in the browning level specification part, it is set according to the specified weak browning level from the predetermined standard cooking time set corresponding to the standard browning level. It is a rice cooker that sets only the cooking time obtained by subtracting the predetermined correction time Δt that has been set as the cooking condition.

According to the above rice cooker, when a browning level that is weaker than the standard browning level is specified in the browning level designation part, it is weaker than the standard cooking time set corresponding to cooking at the standard browning level . Only the cooking time obtained by subtracting the predetermined correction time Δt set according to the browning level is set as the cooking condition, and the end of the cooking process is determined. As a result, even when the temperature difference due to the browning level is small or when it is necessary to end the heating before the temperature rise occurs in the cooking process, the degree of burning can be controlled regardless of the degree of the temperature rise in the cooking process. ..
On the other hand, at the strong browning level, a high cooking temperature is required, so that the temperature difference between the predetermined cooking determination reference temperature and the cooking temperature becomes large according to the strong browning level. Therefore, the degree of charring can be controlled by setting only the cooking temperature obtained by adding the predetermined correction temperature ΔT to the cooking determination reference temperature as the cooking condition.

As described above, according to the present invention, when a browning level weaker than the standard browning level is specified, the standard cooking is set corresponding to the standard browning level regardless of the temperature change in the cooking process. Since the time obtained by subtracting the correction time Δt set according to the browning level from the time is set as the cooking condition, a rice cooker with a small temperature difference due to the difference in the browning level in the cooking process or a weak browning level can be used. When specified, cooked rice can be cooked with a desired degree of charring even in a rice cooker in which a temperature change does not appear in the cooking process.

FIG. 1 is a schematic configuration diagram showing an example of a rice cooker according to an embodiment of the present invention. FIG. 2 is a graph showing a change in the detected temperature during rice cooking operation of the rice cooker according to the embodiment of the present invention. FIG. 3 is a control flow diagram showing an example of rice cooking operation in the rice cooker according to the first embodiment of the present invention. FIG. 4 is a graph showing changes in the detected temperature during rice cooking operation of a conventional home-use rice cooker.

Hereinafter, the rice cooker according to the present embodiment will be specifically described with reference to the drawings.
FIG. 1 is a schematic configuration diagram in which the rice cooker according to the present embodiment is applied to a commercial gas rice cooker (for example, 5 sho). As shown in FIG. 1, this rice cooker includes a rice cooker 1 in which an upper lid 11 is arranged and a gas burner 2 (rice cooker) arranged in the bottom of the rice cooker 1 to heat the rice cooker 1. .. In the gas circuit to the gas burner 2, the first gas valve 22, the second gas valve 23, and the proportional valve 24 are arranged in order from the upstream side, and the first gas valve 22 and the second gas valve 23 are arranged in this order. From between, the gas circuit to the pilot burner 26 is branched.

The rice cooker is equipped with a kettle inner sensor 12 that comes into contact with the back surface of the upper lid 11 of the rice cooker 1 and a kettle bottom sensor 13 that comes into contact with the outer surface of the kettle bottom of the rice cooker 1. The in-pot sensor 12 and the in-pot bottom sensor 13 function as temperature detection units for detecting the in-pot and bottom temperature of the rice cooker 1, respectively, and the detected detection signal is output to the control device 30 described later. ..

The rice cooker includes a charred level designation unit 5 that specifies the degree of charred rice that the user intends to cook. The browning level designation unit 5 is composed of an UP / DOWN counter 50, a browning level raising button 51 connected to the UP input terminal, and a browning level lowering button 52 connected to the DOWN input terminal. Further, the output unit of the UP / DOWN counter 50 is connected to a burnt level indicator 55 provided with a burnt level indicator lamp 54. Then, the degree of charring of cooked rice can be adjusted by the output of the charring level designation unit 5, for example, with the standard charring level being "0" and from "-5" to "+5" in 11 levels of charring. ..

Further, this rice cooker includes a control device 30 that controls the operation of the gas burner 2 that functions as a rice cooker. The control device 30 includes a CPU, a ROM, a RAM, and a timer, and incorporates a microcomputer in which a control program is stored. The first gas valve 22, the second gas valve 23, the proportional valve 24, and the sensor in the kettle are incorporated. 12. It is connected to the bottom sensor 13, the browning level designation unit 5, and the browning level indicator 55. Further, as a functional configuration means, the microcomputer of the control device 30 has a standard browning level or a strong browning level on the “+” side higher than the standard browning level (hereinafter, “standard or strong browning”) in the browning level designating unit 5. When "level" is specified, the cooked rice temperature setting unit 31 that sets the cooked rice temperature E as the cooked condition, and the temperature changing unit that changes the correction temperature ΔT according to the standard or strong browning level. 32. When a weak browning level on the "-" side (hereinafter referred to as "weak browning level"), which is lower than the standard browning level, is specified in the browning level designation unit 5, the cooking time of cooked rice e It is provided with a cooking time setting unit 33 for setting, a time changing unit 34 for changing the correction time Δt according to a weak browning level, a heating capacity changing unit 35 for changing the thermal power (heating capacity) of the gas burner 2. Further, in the memory of the control device 30, a correction temperature ΔT according to the browning level when a standard or strong browning level is specified, and a correction time ΔT according to the browning level when a weak browning level is specified. t, the standard cooking time for setting the cooking time e when a weak browning level is specified, and the like are stored. These were obtained experimentally.

FIG. 2 is a temperature change of the pot bottom temperature detected by the pot bottom sensor 13 when the maximum amount of cooked rice is cooked by designating the standard browning level “0”. To schematically explain the rice cooking operation in the rice cooker of the present embodiment with reference to FIG. 2, the cooked temperature setting unit 31 has a temperature gradient of the pot bottom temperature detected by the pot bottom sensor 13 in the cooking process. When the turning point where is changed from negative to positive ((a) in FIG. 2) is set as the cooking judgment reference temperature T0, and the standard or strong browning level is specified by the browning level designation unit 5, the cooking judgment standard The temperature (T0 + ΔT) obtained by adding the correction temperature ΔT to the temperature T0 is set as the cooked temperature E. Although it is possible to set the water evaporation temperature in the main cooking process as the cooking determination reference temperature T0, the water evaporation temperature for evaporating the water in the rice cooker 1 may not be stable, whereas the water evaporation temperature after the main cooking process may not be stable. In the cooking process, the water content evaporates and the water content in the rice cooker 1 decreases, and then the pot bottom temperature begins to rise. Therefore, the cooking judgment reference temperature is based on the variation point of the temperature gradient of the pot bottom temperature in the cooking process. By setting T0, the temperature at which browning begins to occur more accurately can be used as a criterion.

The temperature changing unit 32 sets the correction temperature ΔT higher as the browning level designated by the browning level specifying unit 5 increases. As a result, when a standard or stronger browning level is specified, if the same browning level is used, the same correction temperature ΔT will be obtained even if the type and quality of rice are different and the cooking judgment reference temperature is different. Set. Table 1 shows the correction temperature ΔT set when a standard or strong browning level is specified for the rice cooker of the present embodiment.

As shown in Table 1, in the present embodiment, when a standard or strong browning level is specified, the correction temperature ΔT is set in 6 steps in 6 ° C increments within the range of 6 to 36 ° C. .. As described above, when the standard or strong browning level is specified, the temperature difference between the cooking determination reference temperature T0 and the cooking temperature E set as the cooking condition becomes large. Therefore, when a standard or strong browning level is specified for a large rice cooker, the degree of charring can be controlled by the correction temperature ΔT.

On the other hand, the correction temperature ΔT when the standard browning level is specified is 6 ° C. Therefore, when a weaker browning level is specified, a plurality of charring due to the correction temperature ΔT less than 6 ° C. It is difficult to control the condition. In particular, in order to cook a small amount of cooked rice with a large rice cooker at a weak browning level that does not cause browning, it is necessary to finish heating before a temperature change appears in the cooking process.

Therefore, in the present embodiment, when a weak browning level is specified by the browning level specifying unit 5, the cooking time setting unit 33 sets the pot bottom temperature when the standard browning level described above is specified. , The time required to reach the temperature obtained by adding the correction temperature ΔT according to the standard browning level to the cooking judgment reference temperature is set as the standard cooking time t0 (for example, 2100 seconds), and from the standard cooking time t0. , The time (t0−Δt) obtained by subtracting the predetermined correction time Δt set according to the browning level is set as the cooking time e. As a result, cooked rice can be cooked according to the browning level specified by the cooking time e without setting the cooking temperature E. Further, when the standard browning level is specified, the cooking condition can be set according to the cooking time, but in the present embodiment, when the standard browning level is specified, the pot bottom temperature is not affected by the cooking time. Since the cooking is determined by the cooking temperature E based on the above, the degree of burning can be controlled more accurately. Therefore, by using the standard cooking time when determining the standard browning level of cooking by temperature control as the reference time for the cooking conditions when a weaker browning level is specified, the standard cooking time can be made more accurate. Can be set to.

The time changing unit 34 sets the correction time Δt longer as the browning level designated by the browning level specifying unit 5 becomes lower. As a result, when a weaker browning level is specified, the lower the browning level, the earlier the cooking time e arrives. Therefore, even a large rice cooker can reduce the amount of combustion before it starts to burn. Table 2 shows the correction time Δt set when a weak browning level is specified in the rice cooker of the present embodiment.

As shown in Table 2, in the present embodiment, when a weak browning level is specified, the correction time Δt is set in 5 steps in 50 second increments within the range of 50 to 250 seconds. As described above, the weaker the browning level, the larger the time difference between the standard cooking time t0 and the cooking time e. Therefore, even when a weak browning level is specified with a large rice cooker, the degree of charring can be controlled by the correction time Δt.

Next, the rice cooking operation in the rice cooker of the present embodiment will be described with reference to the graph of the temperature change of the pot bottom temperature of FIG. 2 and the control flow diagram of FIG. The rice cooker of the present embodiment is configured so that the standard browning level is set when the browning level is not specified by the browning level designating unit 5.

When the user turns on the rice cooking switch (not shown), the timer is turned on, and it is determined whether or not a weak browning level is specified by the browning level specifying unit 5 (steps ST1 to ST2).

When a weak browning level is specified in the browning level designation unit 5, the correction time Δt corresponding to the specified browning level is read, and the time obtained by subtracting the correction time Δt from the standard cooking time t0 is cooked. It is set as the time e (steps ST3 to ST4).

Next, the first gas valve 22, the second gas valve 23, and the proportional valve 24 are opened to ignite the gas burner 2, and the pre-cooking step is executed (steps ST5 to ST6). In this pre-cooking step, the opening degree of the proportional valve 24 is adjusted to control the combustion amount of the gas burner 2, and the rice cooker 1 is heated so that the pot bottom temperature becomes a predetermined pre-cooking temperature (for example, about 50 ° C.). To do. As a result, the water content of the rice grains in the rice cooker 1 increases.

When the predetermined pre-cooking time elapses, the pre-cooking step is terminated and the process proceeds to the main cooking step (step ST7). In the main cooking step, the temperature raising step B1 and the water evaporation step B2 are sequentially executed (see FIG. 2).

In the temperature raising step B1, the rice cooker 1 is heated until the inside of the rice cooker 1 is in a boiling state. At this time, the combustion amount of the gas burner 2 is controlled so that the inside of the rice cooker 1 is in a boiling state. For example, when the pot bottom temperature reaches a predetermined boiling temperature (for example, 120 ° C.), the boiling state is maintained until the water in the rice cooking pot 1 is substantially evaporated, so that the temperature gradient is higher than that at the time of temperature rise. Will also be gradual. Therefore, the change in the temperature gradient is detected from the temperature curve, and when the temperature gradient becomes equal to or less than a predetermined value, the process proceeds to the water evaporation step B2.

In the water evaporation step B2, the rice cooker 1 is heated until the water in the rice cooker 1 is substantially evaporated. When the water in the rice cooker 1 is exhausted in the water evaporation step, the pot bottom temperature rises above the water evaporation temperature, and the temperature gradient changes from negative to positive. Therefore, the change in the temperature gradient is detected from the temperature curve, and when the inflection point of the temperature gradient appears, the process proceeds to the cooking process (step ST8).

Then, in the cooking step, heating is continued with the proportional valve 24 set to a predetermined opening degree (for example, medium) until the cooking time e corresponding to the weak browning level specified by the browning level designating unit 5 elapses. (Step ST9). As described above, in the present embodiment, when a weak browning level is specified, the correction time Δt set according to the browning level is used instead of the correction temperature ΔT, and the standard browning is used. Since the correction time Δt shorter time (t0−Δt) than the standard cooking time t0 set corresponding to the level is set as the cooking time e, the temperature difference due to the difference in the browning level is small. However, the degree of charring can be controlled according to the charring level. Moreover, according to the present embodiment, since the cooking time is set as the cooking condition regardless of the cooking temperature in the cooking process, it is not necessary to raise the temperature in the cooking process to determine the end of cooking. Therefore, even with a rice cooker whose degree of charring cannot be controlled by the correction temperature ΔT, cooked rice can be cooked with a desired degree of charring.

When the cooking time e arrives as described above, the steaming process of closing the first and second gas valves 22 and 23 to extinguish the gas burner 2 and steaming the cooked rice in the rice cooker 1 for a predetermined time is executed. , The whole rice cooking process is completed by the end of this steaming process (steps ST10 to ST11).

On the other hand, when the browning level is not specified by the browning level designation unit 5, or when the standard or strong browning level is specified, the correction temperature ΔT corresponding to the browning level is read and the gas burner 2 is ignited. (Steps ST12 to ST13). Next, the pre-cooking step and the main-cooking step described above are executed, and after shifting to the cooking step (steps ST14 to ST16), the temperature of the inflection point where the temperature gradient of the pot bottom temperature shifts from negative to positive ((A) in FIG. 2 is set as the cooking judgment reference temperature T0, and the temperature (T0 + ΔT) obtained by adding the correction temperature ΔT according to the browning level to the cooking judgment reference temperature T0 is set as the cooking temperature E. Set (steps ST17 to ST18). Then, when the cooking temperature E at which the pot bottom temperature is set is reached, the gas burner 2 is extinguished, a predetermined steaming step is executed, and the entire rice cooking step is completed (steps ST19 and ST10 to ST11).

As described above, in the rice cooker of the present embodiment, at the weak browning level, the correction is set according to the designated browning level from the standard cooking time t0 set corresponding to the standard browning level. The time (t0 − Δt) obtained by subtracting the time Δt is set as the cooking time e, and at the standard browning level or the strong browning level, it is set according to the browning level specified in the cooking determination reference temperature T0. Since the temperature (T0 + ΔT) obtained by adding the correction temperature ΔT is set as the cooked temperature E, the cooked rice with the desired degree of charring can be cooked regardless of which browning level is specified by a large rice cooker. Can be done.

(Other embodiments)
(1) In the above embodiment, the median of the strong browning level and the weak browning level is set as the standard browning level, but the browning level stronger or weaker than the median is set to the standard browning level. You may. In this case, as in the above embodiment, it is preferable to set the browning level at which the cooking temperature can be determined by the correction temperature ΔT to the standard browning level.
(2) In the above embodiment, a constant correction time Δt is set regardless of the amount of cooked rice, but the correction time Δt may be changed according to the amount of cooked rice.
(3) In the above embodiment, after shifting to the cooking process, the cooking is determined based on whether or not the cooking time is set according to the browning level, but in the case of a rice cooker that is easily burnt, it is cooked. It may be set so that the cooking time arrives during the main cooking process prior to the rising process.
(4) In the above embodiment, the gas cooker using a gas burner is mentioned as the rice cooker, but it may be applied to an electric rice cooker using an electric heater.
(5) In the above embodiment, the kettle bottom temperature detected by the kettle bottom sensor is used as the detection temperature, but the kettle temperature detected by the kettle bottom sensor may be used.

1 Rice cooker 2 Gas burner 5 Burnt level designation part 13 Pot bottom sensor 30 Control device

Claims (1)

A rice cooker that heats the rice cooker and
A temperature detector that detects the temperature inside the rice cooker or at the bottom of the rice cooker,
Predetermined standard browning level and browning level,及beauty specifiable browning levels weakening than standard browning level browning level specifying unit also stronger than normal browning level,
Equipped with a control unit that controls the operation of the rice cooker
In a rice cooker that performs a cooking process that heats the cooked rice so that the browned rice specified by the browned rice level designation section is attached.
When a stronger browning level is specified by the browning level designation unit , the control unit designates it as the cooking judgment reference temperature when the detection temperature detected by the temperature detecting unit in the cooking process reaches the predetermined cooking judgment reference temperature. Only the cooking temperature, which is the sum of the predetermined correction temperature ΔT set according to the strong browning level, is set as the cooking condition.
When a browning level that is weaker than the standard browning level is specified in the browning level specification part, it is set according to the specified weak browning level from the predetermined standard cooking time set corresponding to the standard browning level. A rice cooker that sets only the cooking time, which is obtained by subtracting the predetermined correction time Δt, as the cooking condition.

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