JPH0632017Y2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a rice cooker equipped with heating means for heating a container for cooking rice and controlling the input of this heating means to cook rice.

(Prior art) Generally, in this type of rice cooker, the hot water is cooked first when the start switch is turned on, and after this the water has sufficiently penetrated into the rice grain, and then the substantial rice cooking process is performed. During the rice cooking process, boiling detection is performed to detect that the water temperature in the container has reached a boiling state, and the heating amount by the heating means is reduced at the time of this boiling detection, thereby boiling the water in the container. Stablely continue, and the water in the container decreases due to the continuation of such boiling, and the temperature of the container rises, and when the temperature reaches a predetermined temperature, for example, 120 ° C, the rice cooking process is completed as a dry-up state, and the unevenness process is performed. It is designed to move to. Then, by detecting boiling during the rice cooking process and reducing the heating amount by the heating means, various problems that occur when the heating amount reduction control is not performed are solved. In other words, by controlling the decrease of the heating amount, the temperature of each part of the rice cooker rises and the reliability of electronic parts etc. decreases, and the heating amount in the boiling state becomes too large when the capacity is small and the inside of the container Boiled water spills or spills, shortens the boiling duration and does not have the time to maintain the boiling state necessary for gelatinization of rice, leaving rice with a core remaining, and further evaporating water when cooking porridge It solves the problem that the amount becomes large and it does not become a porridge.

By the way, during the rice cooking process, when the temperature of the container reaches around 100 ° C is detected as a boiling state and the amount of heating by the heating means is reduced, low areas such as high altitude areas and bad weather such as typhoons can be used. Since the boiling temperature of the water temperature is low at atmospheric pressure, it is difficult to reach a container temperature of around 100 ° C, which may prevent boiling detection from being performed, and the heating amount reduction control may not be executed, resulting in the various problems described above. There is a risk of doing it.

In consideration of such problems, the temperature of the container during the rice cooking process is lower than the boiling temperature of normal water, for example 90 ° C, and the standard is when the container temperature reaches 90 ° C. Decrease the amount of heating by the heating means that is detected as a boiling state, or reduce the amount of heating by determining that the boiling state has been reached when a predetermined temperature gradient is detected after the container temperature reaches 90 ° C. Although there is a cost problem, a temperature sensor is provided on the container and the lid, and the temperature sensor on the lid detects the generation of steam, and when the steam is detected, it is judged that the boiling state has been reached and the heating amount. I am trying to reduce.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, it is possible to detect boiling in a low pressure state and prevent various problems when the reduction control of the heating amount is not performed. Since constant boiling detection and constant heating amount reduction are always performed without considering the above, delicious rice cannot be obtained in a low pressure state. In other words, to get delicious rice,
It is known that a boiling state duration of 20 minutes or more is required to maintain a boiling state of 98 ° C or higher under atmospheric pressure. Therefore, boiling under 98 ° C is required in order to perform sufficient alpha conversion under low pressure. It is necessary to continue the state or a state close to this state for a longer period than the atmospheric pressure state, but with the conventional rice cooker, the boiling state duration in the low pressure state was short and delicious rice could not be obtained.

Therefore, an object of the present invention is to provide a rice cooker capable of ensuring an appropriate boiling duration time required for α conversion in a low pressure state.

[Structure of the Invention] (Means for Solving the Problem) The present invention is a container 5 for cooking rice, a heating unit 6 for heating the container 5, and a temperature detecting unit 9 for detecting the temperature of the container 5.
A boiling detection means for detecting that the water temperature in the container 5 has reached a boiling state, and a first heating amount for reducing the heating amount by the heating means 6 when the boiling state is detected by the boiling detection means. When the boiling state is not detected by the control means and the boiling detection means until a certain time elapses after the temperature of the container 5 reaches a predetermined temperature, the heating by the heating means 6 is performed by the control by the first heating amount control means. And a second heating amount control means for reducing the amount.

(Operation) When the boiling state is detected by the boiling detecting means, the present invention judges that the state is the atmospheric pressure state and reduces the heating amount by the heating means 6 by the operation of the first heating amount control means so that the temperature of the container 5 becomes a predetermined temperature. When the boiling state is not detected until a certain period of time has elapsed since the temperature reached, the second heating amount control means operates and the boiling state continues for a longer time than the control by the first heating amount control means. Heating means 6
The amount of heating due to is reduced, and sufficient alpha conversion can be obtained in both the atmospheric pressure state and the low pressure state.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, 1 is a bowl body having an inner case 2 and an outer case 3 and the like, 4 is a lid, 5 is a container for containing cooked food contained in the inner case 2, and 6 is a bottom portion of the inner case 2. The rice cooking heater as a heating means provided in the above, 7 is a heat retention heater as a heating means provided on the side surface of the inner case 2 and the inner surface of the lid 4, and 8 is provided so as to be elastically pressed against the outer bottom portion of the container 5. A temperature sensor 9 is provided inside the cup-shaped heat-sensitive section, which is a temperature detecting means for detecting the temperature of the container 5.

FIG. 1 shows a block diagram, 10 is a commercial power supply, and a thermal fuse 11, a rice cooker 6, and a warming heater 7 are provided between both terminals of the commercial power supply.
And the triac 12 is connected in series. A normally open relay switch 13A forming a relay 13 is connected in parallel to the series circuit of the heat insulation heater 7 and the triac 12. Reference numeral 14 is a control means composed of a microcomputer to which a predetermined power supply voltage is supplied via a power supply transformer 15 and a constant voltage circuit 16, which is a well-known CP (not shown).
U, timer means, memory, input circuit, output circuit and the like. The temperature sensor 9 is connected to the input terminal of the control means 14.
A container switch 17 for detecting whether the container 5 is housed in the inner case 2 and each operation switch 18 are connected. Then, the control means 14 detects the temperature signal from the temperature sensor 9 and inputs the inputs of the rice cooking heater 6 and the warming heater 7 to the relay driving circuit 19 and the triac driving circuit according to a predetermined rice cooking program according to the operation content of the operation switch 18. The display drive circuit that controls the display unit 21 while controlling it via 20.
The rice is cooked while controlling it via 22, and when the rice cooking is completed, the relay 13 is turned off to shift to heat retention. Also control means
Reference numeral 14 denotes a boiling detection means for detecting that the water temperature in the container 5 has reached a boiling state, and a first heating amount control for reducing the heating amount by the rice cooking heater 6 when the boiling state is detected by the boiling detection means. Means for maintaining the boiling state for a longer time than the control by the first heating amount control means when there is no detection of the boiling state by the boiling detection means until a certain time elapses after the temperature of the container 5 reaches a predetermined temperature. Thus, the second heating amount control means for reducing the heating amount by the rice cooking heater 6 is provided.

Next, the operation of the rice cooker configured as described above will be described with reference to FIGS. 3 to 6.

In response to turning on of the operation switch 18 for start, the control means 14 first executes the hot water cooking process, and judges the start time of the rice cooking process performed after this process (step 1). For example, the input W _{1 of} 1000 W) is controlled (step 2) to execute the rice cooking process. Then the time count with the detected temperature t of the container 5 during the cooking process to determine whether rose to 90 ° C. (Step 3), initiates boiling detection at P ₁ became t ≧ 90 ° C. (Step 4) Tx and Ty are started (step 5). The control means 14 controls the time count Ty in boiling detection as shown in FIG.
Ty ′ is, for example, every 4 minutes, the time P ₃ when the temperature rise of the container 5 between the _two times P ₂ and P ₃ before and after tx is, for example, 5 deg or less is detected (step 6), and the time P ₂ is detected. If the temperature t is 95 ° C or higher, the detected temperature t at time point P ₃ is
It is judged whether the temperature is 98 ° C or higher (step 7). If these conditions are satisfied, the first heating amount control means controls the input W ₂ of 60% (600 W) to the rice cooking heater 6 at the time point P ₃ (step 8), and then the water content in the container 5 is increased. There is judged whether the detected temperature t of the container 5 decreases is when P ₄ was increased to 120 ° C. or higher (step 9), point P ₄
Then, the rice cooking heater 6 is turned off in the dry-up state (step 10), and the unevenness process is performed. On the other hand, as shown in FIG. 5, even if the temperature rise between the two time points P ₂ and P ₃ is 5 deg or less in step 6, the detected temperature at time point P ₂ is less than 95 ° C. in step 7, and the detection time point P ₃ is detected. temperature
If it is lower than 98 ° C, it is judged whether the time count Tx from the time point P ₁ when the detection temperature t ≧ 90 ° C reaches a fixed time Tx ′, for example, 10 minutes (step 11), and the time P when Tx ≧ 10 minutes is reached.
Detected as a boiling state in the low pressure state in ₅ ,
The second heating amount control means controls the rice cooking heater 6 to have an input W _{3 of} , for example, 30% (300 W) smaller than the input W ₂ to reduce the heating amount (step 12), and then shifts to step 9. When t ≧ 120 ° C., the rice cooking heater 6 is turned off at P ₄ and the process shifts to the unevenness process. In this case, the heating amount of the input W ₃ of the rice cooking heater 6 controlled by the second heating amount control means is compared with that of the rice cooking heater 6 as shown in FIG.
It is also possible to obtain it by controlling on / off with 100% input.

As described above, in the present embodiment, the first heating amount control means causes t ≧ 98 ° C. after 4 minutes have elapsed from the time point P ₂ at t ≧ 95 ° C.
When the rise in the detected temperature during the time P ₃ of 5 deg. Or less is detected as a boiling state at normal pressure, the rice cooking heater 6 is detected.
The heating amount is reduced by controlling the input to W ₁ from W ₁ to W ₂ that can maintain a boiling state of 98 ° C. or more for 20 minutes or more. Therefore, as shown in the water temperature curve a in FIG. It is possible to obtain the boiling state continuation time Ta required for alpha conversion. On the other hand, by the second heating amount control means, a predetermined temperature gradient, that is, two time points P ₂ at intervals of 4 minutes at t ≧ 90 ° C. or more from the time point P ₁ at t ≧ 90 ° C. until a certain time Tx ′, for example, 10 minutes, elapses.
Even increase in temperature detected between P ₃ is equal to or less than 5 deg, less than 95 ° C. the temperature detected by the time point P ₂ is, if the detected temperature at P ₃ is less than 98 ° C., the time P ₅ that after 10 minutes cyclones because detects a boiling input for cooking heater 6 by controlling the W ₂ smaller than W ₃ is intended to reduce the amount of heating in the boiling state continues as temperature curve b shown by the broken line of FIG. 5 The time Tb can be made longer than the time Ta shown in FIG. 4, and it is possible to obtain delicious rice that has been sufficiently α-converted in a low pressure state. Further, when the second heating amount control means cannot detect the predetermined temperature gradient before the elapse of the predetermined time, the time P at which the predetermined time elapses.
_Since the input of the rice cooking heater 6 is controlled by ₅ to reduce the heating amount, the time of 100% input of the rice cooking heater 6 becomes too long and the temperature of each part of the rice cooker becomes too high as before.
It is possible to prevent various problems such as spilling of hot water in the container 5 from occurring. Furthermore, if the detection temperature in the dry-up state is set to 120 ° C, the boiling temperature is lower than the atmospheric pressure state in the low atmospheric pressure state, so it is easy to overheat before the dry-up state occurs, which may result in burnt rice. In the example, since the input W ₃ is small, overheating does not occur, and it is possible to suppress the occurrence of focal spots.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, the heating amount in the first heating amount control and the heating amount in the second heating amount control may be appropriately selected so that the boiling duration time can be longer in the second heating amount control than in the first heating amount control. .

[Effects of the Invention] The present invention includes first heating amount control means for reducing the amount of heating by the heating means when the boiling state is detected by the boiling detection means, and until a certain time elapses after the container temperature reaches a predetermined temperature. By providing the second heating amount control means for reducing the heating amount as compared with the control by the first heating amount control means when there is no boiling detection, an appropriate boiling state duration time required for α conversion in a low pressure state is secured. It is possible to provide a rice cooker that can be done.

[Brief description of drawings]

1 to 6 show one embodiment of the present invention, FIG. 1 is a block diagram, FIG. 2 is an overall sectional view of a rice cooker, and FIG. 3 is a first and second heating amount control means. FIG. 4 is a flowchart showing the operation, FIG. 4 is a graph showing the first heating amount control state, and FIG.
FIG. 6 and FIG. 6 are graphs showing the second heating amount control state. 5 ... Container 6 ... Rice cooking heater (heating means) 9 ... Temperature sensor (temperature detection means) 14 ... Control means (first heating amount control means) (Second heating amount control means) (Boiling detection means)

Claims (1)

[Scope of utility model registration request] 1. A container for cooking rice, heating means for heating the container, temperature detecting means for detecting the temperature of the container, and boiling detecting means for detecting that the water temperature in the container reaches a boiling state. A first heating amount control means for reducing a heating amount by the heating means when a boiling state is detected by the boiling detection means, and the boiling until a certain time elapses after the temperature of the container reaches a predetermined temperature. A rice cooker comprising: a second heating amount control means for reducing the heating amount by the first heating amount control means when the boiling state is not detected by the detection means.