JPH0866304A - Rice cooking method, and rice cooker - Google Patents

Abstract

PURPOSE: To realize correct cooking of long grains of rice by cooking a group of thin and long rice grains of Indica species while applying ultrasonic waves to them for accelerating impregnation of water to boundary parts between the rice grains deposited laterally in a pot, and accelerating vaporization of water content during cooking. CONSTITUTION: In a gas circuit 20 to a gas burner 2, a main valve 21 and a proportional valve 22 are inserted, a heat insulation heater 3 is laid at such a position as to surround an outer circumferential part of a pot 1 heated by the gas burner 2, an ultrasonic oscillator 4 is made in contact with a lower side surface, and an inner temperature detection temperature sensor S is attached on an outer bottom surface. The temperature sensor S, ultrasonic oscillator 4, etc., are electrically connected to a control circuit 5 in which a microcomputer is assembled, and to the control circuit 5, a cooking switch 51, a heat insulation switch 52, and a mode changing switch 53 for cooking long grain rice are connected. When rice grains R are swollen to be applied to each other during cooking action, the rice grains are vibrated by ultrasonic waves, thereby impregnation of water into a rice grain deposition layer can be accelerated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a rice cooking method and a rice cooker capable of properly cooking rice regardless of the type of rice, and particularly to long and narrow rice grains (hereinafter referred to as "long grain" such as Indica varieties represented by Thai rice). It is said that rice can be cooked properly.

[0002]

2. Description of the Related Art With the internationalization of food distribution, in addition to relatively short and round rice grains (hereinafter referred to as "short grain rice") such as Japonica, which is widely consumed in Japan, the above long grain is used. Rice has also become available in the market, and there is a growing demand for the appearance of rice cookers that can cook high-quality cooked rice regardless of the type of rice.

In the rice cooker shown in FIG. 6, a temperature sensor (S) is attached to the wall surface of a pot (1) heated by a gas burner (2), and the temperature detected by the temperature sensor (S) is judged. The combustion amount of the gas burner (2) is controlled by a control circuit (not shown). In this case, when the gas burner (2) burns and the rice cooking operation starts, the water in the kettle (1) boils and its water gradually evaporates, and while the water is boiling, the temperature sensor ( The detection temperature of S) is kept at the boiling point. Then, after the water inside the pot (1) has evaporated, the temperature sensor (S)
The temperature at which rice is cooked is higher than the boiling point.
When the temperature is raised to 5 ° C), the gas burner (2) is maintained in a fire extinguishing state and the rice cooking operation is completed.

However, the above-mentioned rice cooking method is a rice cooking method for short-grained rice, which has been known from experience, and there is a problem that long-grained rice cannot be properly cooked by the rice cooking method.
The above problems will be described in more detail. As described above, since long grain rice is longer and narrower than short grain rice, rice grains (R) tend to accumulate in the kettle (1) in a stable posture with the rice grains (R) laid sideways, and each rice grain (R) is It is in a state where it is deposited in an orderly manner (see FIG. 6). Then, compared with this, long grain rice has a smaller gap at the boundary between the rice grains than short grain rice with roundness, so the water in the pot penetrates into the sediment layer of the long grain rice. It becomes difficult to do so, and especially when the swelling of the rice grains is completed near the completion of the rice cooking, the adhesion between the rice grains becomes high, so that it becomes difficult for water to permeate to the lower part of the accumulated layer of rice grains. From this, the rice grains (R) at the bottom of the kettle are heated and heated to the cooking completion temperature by the gas burner (2) even though the water in the kettle (1) is not sufficiently evaporated. Then
The temperature sensor (S) will detect this rice cooking completion temperature, and the gas burner (2) will be activated before the water in the pot (1) is completely evaporated.
The so-called premature cutting phenomenon that extinguishes occurs, and long grain rice cannot cook properly. [Inventions of Claims 1 and 2] The invention of Claim 1 is made in view of the above-mentioned points.
In the rice cooking method, in which the temperature inside the kettle (1) heated by (2) is detected by the temperature sensor (S) and the rice cooking operation is advanced while judging the detected temperature. It is an object of the present invention to realize proper rice cooking of long grain rice by promoting the evaporation of water content.

[0005]

[Technical Means] The technical means of the invention of claim 1 for solving the above-mentioned problem is that "rice grains are stored in a pot (1) while being irradiated with ultrasonic waves for cooking". is there.

[0006]

According to the above technical means, the rice grains in the cooked rice are vibrated by ultrasonic waves, so that water easily enters the boundary between the rice grains and promotes the penetration of water into the sediment layer of rice grains. To be done. Therefore, even when the time of completion of rice cooking in which the rice grains swell and the degree of adhesion between the rice grains becomes high, the smooth penetration of water to the lower part of the rice grain accumulation layer (the portion close to the pot bottom) can be ensured.
Therefore, even when cooking the long grain rice described above, the water in the pot (1) during the rice cooking is likely to evaporate, and the moisture does not evaporate inside or above the accumulated layer of rice grains after the rice is cooked. It will not remain.

[0007]

The invention of claim 1 has the following unique effect. Even when cooking long grain rice, moisture evaporates smoothly, so that moisture does not remain in the rice grain group at the end of rice cooking, and proper cooking of such long grain rice can be realized.

[0008]

EXAMPLES Next, examples of the invention of claims 1 and 2 will be described. As shown in FIG. 1, a main valve (21) and a proportional valve (22) are inserted in a gas circuit (20) to a gas burner (2), and a kettle (2) heated by the gas burner (2) is inserted. A heat insulation heater (3) is arranged at a position surrounding the outer peripheral portion of (1). An ultrasonic oscillator (4) is in contact with the lower side surface of the kettle (1), and a temperature sensor (S) for detecting the internal temperature is attached to the outer bottom surface of the kettle (1). There is.

The temperature sensor (S), ultrasonic oscillator (4), etc. are electrically connected to a control circuit (5) in which a microcomputer is incorporated, and the control circuit (5) further includes a rice cooker switch (51). ), A heat retention switch (52), and a mode selection switch (53) operated when cooking long grain rice. A control program having the contents shown in the flow chart of FIG. 2 is stored in the microcomputer in the control circuit (5), and the operation of the rice cooker of the embodiment will be described below with reference to the figure.

When it is confirmed that the heat retention switch (52) is turned on by monitoring that the heat retention switch (52) and the rice cooking switch (51) are turned on in steps (60) and (61), step (62) )
To perform the heat retention operation. That is, the heat-retaining heater (3) is caused to generate heat to maintain the cooked rice in the pot (1) at a predetermined temperature. Next, when the above step (61) is executed, the rice cooking switch (5
When it is confirmed that (1) has been input, further steps (61
Execute 1) to determine whether the mode switch (53) is operated. Then, the mode switch (5
If step 3) is operated, the ultrasonic oscillator (4) is activated in step (63), which causes the rice grains (R) placed in the kettle (1).
The group is irradiated with ultrasonic waves of about 5 to 10 MHz and vibrated. Then, the vibration facilitates the entry of water into the boundary between the rice grains (R) (R) and promotes the permeation of water into the sediment layer of the rice grains.

Next, in step (64), the main valve (21) is opened, and the ignition device (59) arranged near the gas burner (2).
Is operated to put the gas burner (2) into a combustion state, and thereby the rice cooking operation is started. Next, reset the timer (T) in step (65) and then in the steps (66) and (67).
(1) A precooking operation is performed to increase the water content of rice grains by maintaining the temperature inside at 45 ° C for 20 minutes. That is, while monitoring the temperature inside the pot with the temperature sensor (S), the proportional valve (2
By controlling the opening of 2), the temperature inside the kettle (1) can be adjusted to 4
Hold at 5 ° C for 20 minutes.

Next, when the preliminary cooking process is completed, the main cooking process for executing steps (68) to (72) is started. The main cooking step is a step of evaporating the water in the kettle (1). First, the opening degree of the proportional valve (22) is increased to burn the gas burner (2) with high flame. As a result, when the temperature inside the kettle detected by the temperature sensor (S) reaches 115 ° C., the opening of the proportional valve (22) is narrowed down and the gas burner (2) is burned with a low heat. And the temperature sensor
When the temperature in the pot detected by (S) reaches 145 ° C, which is the completion temperature of rice cooking, the ultrasonic oscillator (4) is stopped and the main valve (21) is closed in step (72) to extinguish the gas burner (2). Keep in the state. Even if the rice grains swell during the main cooking operation and the rice grains (R) (R) come into close contact with each other, these rice grains (R) (R) are ultrasonically generated by the ultrasonic oscillator (4). Since the water is vibrated, the penetration of water into the sediment layer of these rice grains is promoted, and even when cooking long grain rice with a small gap between the rice grains, the moisture content of There is no inconvenience of incomplete evaporation. That is, the gas burner (2) does not cause so-called premature disconnection.

When the main cooking step is completed, a steaming operation of waiting for 10 minutes is executed in step (73), thereby completing the rice cooking operation. If it is determined that the mode switch (53) is not operated when step (611) is executed, the ultrasonic oscillator (4)
The rice cooking operation from step (64) onward is executed without activating. Therefore, in this case, the rice grains (R) (R) are not vibrated by the ultrasonic waves, and the rice cooking operation suitable for the ordinary rice cooking of short grain rice proceeds. [Inventions of Claims 3 and 4] The invention of claim 3 solves the same problem as the invention of claim 1.

[0014]

[Technical Means] According to the technical means of the invention of claim 3, the temperature in the pot (1) heated by the gas burner (2) is detected by a temperature sensor.
In the rice cooking method, which is detected by (S), the rice cooking operation is advanced while judging the detected temperature.
(B) cooked rice while vibrating the pot (1). ”

[0015]

[Operation / Effect] According to the above technical means, the vibration of the vibrator (B) during rice cooking causes the kettle (1) to vibrate, and the rice grains (R) (R) inside the kettle also vibrate. Become. Then, the vibration of the rice grains (R) (R) facilitates the entry of water into the boundaries between the rice grains, thereby promoting the permeation of water into the sediment layer of the rice grains. Therefore, even when the time of completion of rice cooking in which the rice grains swell and the degree of adhesion between the rice grains becomes high, the smooth penetration of water to the lower part of the rice grain accumulation layer (the portion close to the pot bottom) can be ensured. Therefore, even when rice is cooked with long grain rice as described above, water in the pot (1) easily evaporates during rice cooking, and moisture does not evaporate inside or above the accumulated layer of rice grains after completion of rice cooking. It will not remain as it is. Therefore, proper rice cooking of long grain rice can be realized.

[0016]

EXAMPLES Next, examples of the inventions of claims 3 and 4 will be described. As shown in FIG. 3, the upper frame (8) detachably mounted on the lower frame (A) equipped with the gas burner (2) etc., has an inner shell (80) surrounding the kettle (1). ) And its outer body (81)
And a heat insulation layer (82) consisting of a heat insulation layer (82) loaded between these
3) is provided, and heat-resistant rubber rings (84) (89) for contacting and supporting the shuttle (1) are provided on the inner circumference and the bottom of the inner body (80). In addition, the heat insulation layer (82)
A heat insulation heater (3) is provided inside.

Further, the inner body (80) is provided with a recess (85), and the recess (85) is loaded with an electromagnetic coil (86) functioning as a vibrator (B). Coil (8
On the hook (1) corresponding to the magnetic pole of (6), iron magnetic bolt (8
7) is screwed and fixed. Further, the upper end opening of the shuttle (1) is openably and closably covered by a lid body (92) having a removable inner lid (91).

As shown in FIG. 4, in the gas circuit (20) to the gas burner (2) for heating the kettle (1), a main valve (21) and a proportional valve are provided.
(22) is inserted, and a temperature sensor (S) for detecting the internal temperature is attached to the outer bottom surface of the shuttle (1). The electromagnetic coil (86) and the temperature sensor (S) are electrically connected to a control circuit (5) in which a microcomputer is incorporated, and the control circuit (5) further includes a lower frame (A) operation unit. A rice cooker switch (51) and a heat retention switch (52) provided in (58), and a mode selector switch (53) operated when cooking long grain rice are connected.

A control program having the contents shown in the flow chart of FIG. 5 is stored in the microcomputer in the control circuit (5), and the operation of the rice cooker of the embodiment will be described below with reference to FIG. If it can be confirmed that the heat retention switch (52) or rice cooker switch (51) has been turned on in steps (100) and (101) and it can be confirmed that the heat retention switch (52) has been turned on, heat retention operation will be performed in step (102). To execute. That is, the heat retention heater
(3) is heated to keep the cooked rice in the kettle (1) at a predetermined temperature.

Next, when it is confirmed that the rice cooking switch (51) is turned on when the step (101) is executed,
Execute step (103) and switch the mode (53)
It is determined whether or not is operated. If the mode selector switch (53) is operated, step (1
Apply alternating current to the electromagnetic coil (86) with 04). Then
The magnetic bolts (87) are periodically attracted by the electromagnetic coil (86), and the periodic attraction operation and the rubber rings (84) (8
The elasticity of 9) causes the hook (1) to vibrate, and in synchronization with this, the hook (1) vibrates.
(1) Rice grains (R) and (R) inside will also vibrate. Then, the vibration facilitates the entry of water into the boundary between the rice grains (R) and (R), which promotes the permeation of water into the sediment layer of the rice grains.

Next, in step (105), the main valve (21) is opened and the ignition device (5) installed near the gas burner (2) is opened.
9) is activated to put the gas burner (2) into a burning state, and the rice cooking operation is started. Next, reset the timer (T) in step (106), and then in steps (107) (10
In step 8), the precooking operation is performed to increase the water content of rice grains by maintaining the temperature in the kettle (1) at 45 ° C for 20 minutes. That is, by controlling the opening of the proportional valve (22) while monitoring the temperature inside the kettle with the temperature sensor (S), the temperature inside the kettle (1) is maintained at 45 ° C. for 20 minutes.

Next, when the preliminary cooking process is completed, the main cooking process for executing steps (109) to (113) is started. The main cooking process is a process of evaporating the water in the kettle (1),
First, the opening of the proportional valve (22) is increased and the gas burner (2) is burned with high flame. As a result, when the temperature inside the kettle detected by the temperature sensor (S) reaches 115 ° C., the opening of the proportional valve (22) is narrowed down and the gas burner (2) is burned with a low heat. And the temperature sensor
When the temperature in the pot detected by (S) reaches 145 ° C, which is the completion temperature of rice cooking, the electromagnetic coil (86) is turned off in step (113) and the main valve (21) is closed to turn on the gas burner (2). Keep fire extinguished. Then, even when the rice grains swell during the main cooking operation and the rice grains (R) (R) come into close contact with each other,
Since the rice grains (R) (R) are vibrated by the operation of the electromagnetic coil (86), the penetration of water into the sediment layer of these rice grains is promoted, and the long grain rice with a small gap between the rice grains is formed. Even when cooking rice, there is no inconvenience of incomplete evaporation of water, unlike the conventional ones. That is, the gas burner (2)
Does not cause so-called premature disconnection.

When the main cooking process is completed, a steaming operation of waiting for 10 minutes is executed in step (114), thereby completing the rice cooking operation. If it is determined that the mode switch (53) is not operated when step (103) is executed, the electromagnetic coil (86)
The rice cooking operation in step (105) and the following steps is executed while keeping the OFF state. Therefore, in this case, the cooking operation suitable for ordinary rice cooking of short grain rice proceeds without vibrating the pot (1).

[Brief description of drawings]

FIG. 1 is a control circuit diagram of a rice cooker implementing the invention of claim 1.

FIG. 2 is a flow chart of rice cooking control used in the embodiment of the invention of claim 1.

FIG. 3 is a cross-sectional view of a rice cooker that implements the invention of claim 3.

FIG. 4 is a control circuit diagram of a rice cooker that implements the invention of claim 3.

FIG. 5 is a flowchart of rice cooking control used in the embodiment of the invention of claim 2;

FIG. 6 is an enlarged view showing the state of the inside of the pot when cooking rice.

[Explanation of symbols]

 (1) ・ ・ ・ Kettle (2) ・ ・ ・ Gas burner (4) ・ ・ ・ Ultrasonic oscillator (B) ・ ・ ・ Vibrator (S) ・ ・ ・ Temperature sensor

Claims (4)

[Claims] 1. A rice cooking method in which the temperature inside a pot (1) heated by a gas burner (2) is detected by a temperature sensor (S) and the rice cooking operation is advanced while judging the detected temperature. A rice cooking method in which rice grains stored in a pot (1) are cooked while being irradiated with ultrasonic waves. 2. The rice is cooked while the ultrasonic oscillator (4) is activated by providing an ultrasonic oscillator (4) for irradiating ultrasonic waves to the rice grains stored in the kettle (1) and a mode selector switch (53). A rice cooker in which the operation and the operation of cooking rice without operating the ultrasonic oscillator (4) can be switched by the operation of the mode selection switch (53). 3. A rice cooking method in which the temperature in a pot (1) heated by a gas burner (2) is detected by a temperature sensor (S) and the rice cooking operation is advanced while judging the detected temperature. , Rice cooking method in which the vibrator (B) vibrates the pot (1) to cook rice. 4. The rice cooking method according to claim 3, wherein a mode in which the vibrator (B) is activated and a mode in which it is not activated can be selectively switched during the rice cooking operation.