JPH04371113A - Rice cooking method, rice cooker adopting above method and automatic rice cooking appliance - Google Patents

Abstract

PURPOSE:To dispense with steam discharge for a reduction in the consumption of electric power by, after rice attains to a fixed temperature lust before boiling, heating it for a fixed time as the above temperature is kept. CONSTITUTION:A heating plate 10 having a buried rice cooking heater 9 is attached to the lower part of an inner pot 13 to accommodate a necessary quantity of rice and water, and a temperature detecting means 19 to detect fixed temperature T just before boiling, namely 98-100 deg.C, is provided at the middle of the underside of a cover plate 16. In addition to that, a bottom body 2 is provided with a control device 22 composed of a timer 21 which starts when the temperature detecting means 19 has detected a fixed temperature T just before boiling and times 25 minutes, and a microcomputer or the like to control the rice cooking heater 9 or the like on signals concerned with the above matters. Thus the temperature inside the inner pot 13 can be controlled so as to keep below 100 deg.C during rice cooking to reduce the consumption of electric power and moreover to cook the rice so as to have uniform rice grains and their fine surfaces.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooking method using electric heating, electromagnetic induction heating or gas fire heating, and a rice cooker and automatic rice cooking apparatus for carrying out the method.

0002

[Prior Art] In the conventional rice cooking method using, for example, an electric rice cooker, the required amount of rice and water added to the required water absorption amount are placed in a pot, and the rice is heated by a rice cooking heater as shown in FIG. First, the water is preheated and maintained at a specified temperature for a certain period of time, allowing the rice to absorb sufficient water. Then, the rice starts cooking over high heat using a large amount of power, and when the rice starts to boil, the electricity supply rate to the rice cooking heater is controlled to reduce the power slightly, and the boiling state continues until the excess amount of water is used up. The water is gone and the temperature at the bottom of the pot is 100℃.
When the temperature suddenly rises above the temperature and the temperature detecting means detects this, the rice cooking heater is turned off based on this signal. After that, the pot is heated and steamed using a small amount of electricity for a certain period of time to promote gelatinization of the starch.

[0003] The reason why extra water is added to the minimum amount of water required to absorb the required amount of rice is that the boiling state continues due to this extra water, so the temperature can be increased by 10 minutes without adjusting the temperature.
This is for gelatinization by maintaining the temperature at 0°C. Moreover, when this excess water is removed, the temperature rises rapidly beyond the boiling point, so by detecting this point, it is possible to easily determine when rice cooking is complete.

Incidentally, in recent years, an automatic rice cooking device has been proposed in which a rice cooker is built into a storage box such as a cooking table, and the rice is cooked and kept warm while the rice cooker is stored. In this type of automatic rice cooking device, since the rice cooker emits a large amount of steam as mentioned above, it is necessary to store the rice cooker as shown in, for example, Japanese Patent Application Laid-Open No. 62-26031 and Japanese Patent Publication No. 63-63205. The box body is provided with an exhaust passage and a forced exhaust device to exhaust the steam emitted by the rice cooker to the outside of the box body.
As shown in Publication No. 69, etc., measures have been taken such as installing a heat exchange device to cool the steam emitted by the rice cooker and converting it back into water.

[0005]

[Problems to be Solved by the Invention] However, in the conventional rice cooking method, excess water is boiled and evaporated, which consumes more electricity than is necessary for the original rice cooking, and a large amount of steam is released. It was having a negative impact on the surrounding indoor environment. Additionally, convection during boiling caused the rice grains to collide with each other, causing them to become chipped or crushed, resulting in uneven rice grains. Additionally, a steam vent was needed to let the steam escape, and an inner lid was needed to cover the pot to prevent boiling over. For this reason, the inner lid had to be removed and carefully washed every time rice was cooked.

[0006] On the other hand, even in an automatic rice cooking device with a built-in conventional rice cooker, as mentioned above, an exhaust system and a heat exchange device must be provided, and these devices require extra space and space inside the storage box. A mechanism was needed. Furthermore, for devices that emit steam, the location of the exhaust port and exhaust pipe had to be determined by considering surrounding kitchen equipment and indoor layout. However, even with these exhaust measures, it is not possible to completely remove the steam, so if the inside of the device is not constantly cleaned and cleaned, problems such as mold growth and pest intrusion may occur. there were.

[0007] The present invention aims to solve such problems, and provides a rice cooking method that can cook rice while suppressing boiling, does not emit steam, and consumes less power, and a rice cooker for carrying out the method. The object of the present invention is to provide an automatic rice cooking device that does not require measures for steam exhaust.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the rice cooking method according to the present invention includes heating a pot containing a required amount of rice and water necessary for absorbing the rice at a predetermined temperature just before boiling. and a step of continuing heating for a predetermined period of time until the rice cooking is completed while maintaining the temperature just before boiling.

[0009] Furthermore, a rice cooker for carrying out this method includes a pot containing a required amount of rice and water necessary for absorbing the rice;
a heating means for heating the pot; a lid without an inner lid for covering the pot; a temperature detection means provided on the lid for detecting a predetermined temperature immediately before boiling; a timer means for measuring a predetermined time after detecting a predetermined temperature; and a heating means for heating the temperature until the temperature detecting means detects a predetermined temperature just before boiling; and control means for causing the heating means to continue heating while maintaining the temperature immediately before boiling until the time is counted.

[0010] Furthermore, the automatic rice cooking apparatus for carrying out the rice cooking method is such that the rice cooker is housed in a storage box and rice is cooked in the housed state.

[0011] The predetermined temperature immediately before boiling is a temperature necessary for gelatinizing the starch of rice, and is 98 to 100°C. In addition, the predetermined time for continuing heating after detecting the predetermined temperature is the time when water absorption is completed and gelatinization is sufficiently performed from the state immediately before boiling, and this is almost constant regardless of the amount of rice cooked. The present inventors have confirmed that it is ~25 minutes. Note that as the heating means, not only an electric heater but also electromagnetic induction heating, gas fire heating, etc. are employed.

0012

[Operation] After reaching a predetermined temperature just before boiling, the cooking temperature is maintained at 98 to 100°C by continuing heating for a predetermined time while maintaining that temperature. This allows water absorption and
The starch in the rice is gelatinized, and the rice is completely cooked without any release of steam.

[0013]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a rice cooker according to the present invention, and in the figure, a bottom body 2 is fitted to the lower end of the exterior body 1, a shoulder body 3 is fitted to the upper end, and an outer pot 4 is housed inside. A body heat-retaining heater 5 is disposed on the outer peripheral surface of the outer pot 4. Also outside pot 4
A tray-shaped support plate 7 is accommodated in an opening 6 formed at the bottom of the outer pot 4, and this support plate 7 is elastically supported by a spring 8 on the bottom of the outer pot 4. A rice cooking heater 9 is mounted on the upper surface of the support plate 7.
A heating plate 10 with a heat shield embedded therein is attached, and a heat shield plate 11 is attached to the lower surface. A pot bottom temperature detecting means 12 is attached to the center of the heating plate 10.

The inner pot 13 has a flange 14 on the outer periphery of the upper end,
When placed in the outer pot 4 and placed on the heating plate 10, the pot bottom temperature detection means 12 comes into pressure contact with the outer surface of the bottom, and the weight of the rice and water accommodated therein causes the spring force of the spring 8 to be applied. As a result of the heating plate 10 being pushed down against the
The flange portion 14 is brought into pressure contact with the upper end of the outer pot 4.

[0015] The lid body 15 is attached to the shoulder body 3 by a hinge 15a so as to be openable and closable. A seal packing 17 is attached around the lid plate 16 attached to the inner surface of the lid body 15 to be in pressure contact with the upper end of the inner pot 4. Further, a lid heat insulating heater 18 is disposed on the upper surface of the lid plate 16, and a temperature detecting means 19 for detecting a predetermined temperature T of 98 to 100° C. immediately before boiling is mounted at the center of the lower surface. The lid plate 1
6 is not provided with an inner lid for covering the inner pot 13 or a steam vent as shown by the two-dot chain line. However, for safety reasons, a steam escape port may be provided in the cover plate 16, and a steam passage may be formed from the steam escape port through the hinge portion (15a) to the dew pan 20 provided on the shoulder body 3. .

The bottom body 2 includes a timer 21 that starts when the temperature detection means 19 detects a predetermined temperature immediately before boiling and measures 25 minutes;
A control device 22 including a microcomputer or the like is provided to control the rice cooking heater 9, the body heat-retaining heater 5, and the lid heat-retaining heater 18 based on signals from 2, 19 and a rice cooking switch (not shown).

In the rice cooker having the above configuration, the rice cooking method according to the present invention is executed by the control device 22. That is, when a required amount of rice and water necessary for its absorption are put into the inner pot 13 and a rice cooking switch (not shown) is pressed, the rice cooking heater 9 first preheats and maintains the water temperature at a predetermined temperature for a certain period of time. This causes the rice to absorb water.

Thereafter, the rice cooking heater 9 is controlled at a 100% energization rate to start cooking rice with a large power of 1000W, as shown in FIG. When the temperature detecting means 19 provided on the lid plate 16 detects a predetermined temperature T between 98 and 100 degrees Celsius just before boiling, the timer 21 is started and the rice cooking heater 9 is temporarily turned on to prevent overshoot. (minute) After turning off, heating is continued with a small power of 50 W by controlling the rice cooking heater 9 at a low energization rate. In addition, if the temperature of the pot bottom is adjusted to 100° C. by the pot bottom temperature detection means 12, the internal temperature can be reliably suppressed to 100° C. or less.

[0019] In this way, since heating is performed with a small amount of electric power, boiling is suppressed as much as possible during cooking, and the temperature between 98 and 100°C, which is the temperature necessary for gelatinization of starch, is maintained. . Furthermore, since boiling is suppressed, there is no release of steam, and there is no adverse effect on the indoor environment such as condensation on peripheral equipment, glassware, etc. Furthermore, only the water necessary for water absorption is placed in the inner pot 13, there is no excess water, and boiling is suppressed as described above, so that almost no convection occurs. This prevents the rice grains from colliding with each other and causing them to break, resulting in rice with uniform grains and a beautiful surface.

[0020] Eventually, when the timer 21 counts 25 minutes and the time is up, the control device 22 turns off the rice cooking heater 9. This completes the rice cooking, and thereafter the lid heater 18 and the body heater 5 are turned on to keep the cooked rice warm. In this way, rice is cooked with high power until the temperature detection means 19 detects a predetermined temperature T just before boiling, and thereafter, heating is performed with low power, so power consumption is extremely small. Since boiling is suppressed in the rice cooker according to the present embodiment, the lid is not stained by slime, and there is no need for the troublesome work of removing and washing the rice every time rice is cooked, which is the case with conventional rice cookers.

FIG. 4 shows an automatic rice cooking device according to the present invention, which includes a storage box body A, a ricer section B, a water supply section C, a rice washing section D, a drain section E, and a rice cooking section F. and control section G
It consists of The storage box body A has a rectangular box shape, and is provided with an openable and closable upper lid 31 on its upper surface that is opened when storing rice in a rice bin 35 and can also be used as a cooking table. In addition, on the front, there is an operation panel 32,
A window 33 for checking the amount of rice in the rice pot 35 and a door 34 that is opened when the rice cooker 59 is taken out are provided.

Ricer section B includes a rice bin 35 and a measuring device 36.
It consists of The rice bin 35 has a funnel shape, and rice is stored through an opening 37 at the upper end and flows out through an outlet 38 at the lower end, and a rice bin window 39 is provided on the side for checking the amount of rice. is provided. The measuring device 36 is rotatable by a motor 40 and is formed integrally with a shutter 41 that opens and closes the outlet 38 of the rice bin 35. When this measuring device 36 is rotated in the direction of arrow a, the shutter 41 opens the outlet 38 of the rice bin 35 and accepts a certain amount of rice flowing out from the outlet 38.
When rotated in the direction of arrow b, the shutter 41 closes the outlet 38 and the received rice flows down to the rice washing section D.

The water supply section C includes a water supply tank 44 that receives water from a water supply port 42 protruding from the top surface of the storage box A through a water stop valve 43, and a water supply tank 44 that receives water from the water supply tank 44 through a water supply valve 45 to wash rice, which will be described later. It consists of a water supply pipe 46 that supplies water to part D. The rice washing section D has an upper case 47 and a lower case 48.
and a stirring rod 49. The upper case 47 is formed with a rice inlet 50 for receiving rice flowing down from the ricer section B and a water inlet 51 for receiving water from the water supply section C. The lower case 48 is rotatably provided by a motor 52, and rotates in the direction of arrow c to form an airtight container together with the upper case 47, and rotates in the direction of arrow d to collect washed rice and water, which will be described later. It is designed to be poured into the rice cooking section F. This lower case 48 is formed with an outlet 53 through which overflowing water flows out, and is also equipped with a turbidity sensor 54 that detects the turbidity of water during rice washing. The stirring rod 49 is provided in a closed container formed by an upper case 47 and a lower case 48, and can be rotated by a motor 55, and is used to polish or wash rice stored in the container. There is.

[0024] The drainage section E is the lower case 48 of the rice washing section D.
It consists of a drain tank 56 that receives water that overflows, and a drain pump 58 that sucks the water in the drain tank 56 and drains it from a drain port 57 provided on the top surface of the storage box body A. The rice cooking section F includes a rice cooker main body 6 that is housed in a storage box body A and is movable back and forth on a rail 59.
0, and a lid 61 that is slidably provided on the inner wall of the storage box body A and covers the rice cooker main body 59. The rice cooker main body 60 and the lid body 61 have substantially the same configuration as the rice cooker described above, so a description thereof will be omitted. Based on the operation of the operation panel 32, the control section G controls the ricer section B,
The water supply section C, rice washing section D, drainage section E, and rice cooking section F are controlled to automatically perform operations from measuring rice to cooking the rice.

The operation of this rice cooking device will be explained below. After opening the water stop valve 43, specify the amount of rice to be cooked and whether to polish or wash the rice on the operation panel 32, and press the start switch.
It rotates in the direction of arrow b, and a certain amount of rice flows into the measuring device 36, and then it rotates in the direction of arrow b, and the weighed rice flows into the upper case 4.
7 and a lower case 48. By repeating this, the specified amount of rice is stored in the airtight container. If polished rice is specified, the stirring rod 49 is rotated by the motor 55 and the rice is polished before water is supplied. When washing rice is specified, the water supply valve 45 opens and the lower case 4
Water is injected into the chamber 8 and the stirring rod 49 rotates.
The rice is washed with water overflowing from the outlet 53. The overflow water flows down into the drain tank 56 and is drained outside by the drain pump 58.

During this rice washing, when the turbidity sensor 54 detects that the turbidity of the water has become below a predetermined value, the water supply valve 45 is closed, the stirring rod 49 is stopped, and the lower case 48 is opened and the rice is washed. The rice is poured into the inner pot 62 of the rice cooker main body 60 together with water. Subsequently, the lower case 48 is closed and the water supply valve 4 is closed.
5 is opened and additional water is poured to reach the predetermined amount of water.
The lower case 48 opens again and the additional water flows down into the inner pot 62. In the case of polished rice, a predetermined amount of water is poured into the inner pot 62 in the same manner. Next, the lid 61 slides forward to cover the rice cooker main body 59, and the rice cooking heater is controlled as described above to perform rice cooking.

When cooking rice, as mentioned above, no steam is released, so the storage box body A will not be filled with steam, and the storage box body A will not be filled with steam. There is no need to provide Therefore, storage box body A
The inside is kept clean and there is no mold or pest infestation.

[0028]

[Effects of the Invention] As is clear from the above explanation, according to the rice cooking method according to claim 1, the rice cooking method according to the first aspect does not require adding an excess amount of water.
Since the rice is heated with low power from just before boiling to suppress boiling as much as possible, no steam is released and there is no adverse effect such as condensation on the surrounding indoor environment. In addition, power consumption is reduced compared to the conventional method of continuing the boiling state for a long time. Furthermore, since there is no excess water and the boiling is suppressed, the rice is cooked quietly without violent convection, resulting in beautiful rice with even grains on the surface. Further, according to the rice cooker according to claim 2, there is no release of steam or boiling over, so there is no need for a steam vent or an inner lid made of expensive heat-resistant materials like in conventional rice cookers, and the rice cooker is inexpensive and can be used every time rice is cooked. This eliminates the troublesome work of removing and washing the inner lid. Furthermore, according to the automatic rice cooking device of claim 3, since no steam is generated during rice cooking, there is no need to provide an exhaust pipe or a forced exhaust device for discharging steam inside the storage box body. Furthermore, since the steam does not condense on the inner walls of the storage box or each device, there is no risk of mold or pests invading.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing temporal changes in rice cooking temperature and electric power according to the rice cooking method according to the present invention.

FIG. 2 is a sectional view of the rice cooker according to the present invention.

FIG. 3 is a diagram showing temporal changes in rice cooking temperature and energization rate according to a conventional rice cooking method.

FIG. 4 is an elevational view of the automatic rice cooking device according to the present invention.

[Explanation of symbols]

9... Rice cooking heater (heating means), 13... Inner pot, 15... Lid, 19... Temperature detection means, 21... Timer, 22... Control device, A... Storage box body.

Claims (3)

[Claims] Claim 1: A process of heating a pot containing a required amount of rice and water necessary for its absorption until it reaches a predetermined temperature just before boiling, and a predetermined period of time until the rice is cooked while maintaining the temperature just before boiling. A rice cooking method characterized by including a step of continuing heating. 2. A pot containing a required amount of rice and water necessary for absorbing the rice, a heating means for heating the pot, a lid without an inner lid for covering the pot, and a lid provided on the lid. temperature detecting means for detecting a predetermined temperature immediately before boiling; timer means for measuring a predetermined time after the temperature detecting means detects a predetermined temperature immediately before boiling; and control means for causing the heating means to heat until the predetermined temperature is detected, and for causing the heating means to continue heating while maintaining the temperature immediately before boiling until the timer means measures a predetermined time after detecting the predetermined temperature. Characteristic rice cooker. 3. An automatic rice cooking device characterized in that the rice cooker according to claim 2 is housed in a storage box body, and rice is cooked in the stored state.