JPH07110263B2 - Electric rice cooker - Google Patents

Description

Detailed Description of the Invention

[0001]

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an electric rice cooker, and more particularly to an improvement of an electric rice cooker in which heating control during rice cooking is performed by a microcomputer or the like.

[0002]

2. Description of the Related Art In electric rice cookers, so-called microcomputer-controlled electric rice cookers in which heating control during rice cooking is controlled by a microcomputer have been put into practical use, and various types of rice cookers have been sold. In the conventional so-called microcomputer-controlled electric rice cooker, the electricity to the rice cooker heater is controlled according to the amount of rice cooked, and the inner pot temperature rises along an ideal reference temperature curve. There is (for example, the second patent application of 1990 in the applicant's earlier application)
90014).

Such a microcomputer-controlled electric rice cooker has a mechanism in which the temperature of the inner pot is detected by a temperature sensor and the microcomputer controls energization of the rice cooker heater based on the detected temperature.

[0004]

By the way, in general, the inner pot can be taken out from the main body, as is well known. Therefore, if this inner pot is set correctly in the main body, the temperature of the inner pot is accurately detected and ideal rice is cooked, but if the inner pot is not set correctly, The temperature sensor cannot accurately detect the temperature.

[0005] For example, the inner pot is set in the main body after washing rice and filling a certain amount of water. Therefore, rice grains may adhere to the bottom of the inner pot. When the inner pan is set in such a state, the deposited rice grains caught between the pan bottom and the cooking heater, in a state like this, the temperature sensor is unable to detect the inner bowl temperature accurately, as a result However, there was a drawback that the optimum rice cooking control could not be performed.

Further, it is known that the temperature rise during rice cooking is relatively high mainly in the case of boiled rice cooked with salt, etc., based on the temperature rise in the case of rice cooked with white rice. In such a case, if the same temperature control as normal rice cooked was performed, even if the rice was not cooked, the temperature detected by the temperature sensor increased to a predetermined temperature and the power supply to the rice heater was stopped. was there.

Therefore, the present invention has been made in order to solve the above-mentioned problems, and when the inner pot is not properly set due to the adherence of rice grains or other foreign substances to the bottom of the inner pot, or the white rice even if a special cooking stove like cooked other than rice, to provide an electric cooker that can without the need for special operation and mode selection, subjected to pressurized heat control, I'll come 炊delicious rice To aim.

[0008]

Means for Solving the Problems] The present invention, in the first, an electric rice cooker to perform cooking by heating the inner pot by cooking heater, a temperature sensor for detecting the inner bowl temperature, the temperature sensor And a time measuring means for starting time measurement when the temperature of the inner pot reaches a first temperature at which the contents of the inner pot start to boil, or a time determined by the time measuring means is preset, or the temperature detected by the temperature sensor is the first temperature. Observe whether or not a predetermined second temperature higher than the boiling temperature, which is the temperature , is reached, and set the predetermined time.
During the counting, in particular in response not reach the second temperature,
After that, the ordinary rice-cooking control means for performing energization control for the ordinary rice-cooking on the rice-cooking heater and the time measured by the time-measurement means, or the temperature detected by the temperature sensor is the first
Observing whether a predetermined second temperature higher than the boiling temperature, which is the temperature , is reached, and in response to the detected temperature reaching the second temperature before the predetermined time is timed, the rice cooking heater is subsequently used. On the other hand, a special rice-cooking control means for controlling energization for the special rice-cooking according to the time from the first temperature to the second temperature is included.

[0009] Second, an electric cooker that performs cooking by heating the inner pot by cooking heater, the first temperature sensor for detecting the inner bowl temperature, the temperature detected by the temperature sensor is predetermined counting means to start time counting in response to become the boiling temperature is the temperature, when the counting means has counted a predetermined time, detects the temperature of the temperature sensor, below the second temperature detected temperature predetermined At this time, after that, the normal rice-cooking control means for performing energization control for the normal rice-cooking on the rice-cooking heater, and when the detected temperature is equal to or higher than a predetermined second temperature, thereafter, the special rice-cooking according to the detected temperature is performed on the rice-cooking heater And a special rice-cooking control means for controlling energization for.

[0010]

[Action] from the temperature of the inner pan bottom portion is detected for example has reached the boiling AgaAtsushi degree is the first temperature by temperature sensor, detection temperature is a second temperature special cooking determination temperature (e.g., 11
0 ℃) observed up to. Then, ordinary rice in accordance with this observation, it is determined that special cooking, if more of the special cooking is
Different cook raised temperature is set, cook mentioned process is continued until it reaches its cooking raised temperature.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing an external shape of an electric rice cooker according to an embodiment of the present invention. The electric rice cooker has a main body 1 and an openable / closable lid unit 2 provided on the upper portion of the main body 1 as shown in the figure. The lid unit 2 is opened by pressing a push button 3 provided on the front upper portion of the main body 1 as shown by a chain line. An inclined surface 4 inclined from the front to the depth direction is formed on the upper front surface of the main body 1, and the inclined surface 4 is a display for displaying time data such as time, rice cooking reservation time, and rice cooking time, and other data. The container 5 is arranged and a plurality of operation buttons 6 are arranged. The operation button 6 is used, for example, when performing a quick cooking operation without a water supply stroke, selecting a cooking menu such as cooking porridge, and setting a timer for reserving rice cooking time.

FIG. 2 is a schematic sectional view taken along the line AA of FIG. 1, showing the internal structure of this electric rice cooker. Figure 2
The main body 1 of the electric rice cooker includes a cylindrical cover member 7 made of a thin metal plate forming an outer surface thereof, an inner container 8 forming an inner side thereof, and a cover member 7. A shoulder member 9 that connects the upper edge portion and the upper edge portion of the inner container 8 to form the shoulder of the main body 1, and a bottom member 10 that is fitted to the lower edge portion of the cover member 7 to form the bottom of the main body 1. And have.

A temperature sensor 11 is arranged at the center of the inner bottom of the inner container 8, and a rice cooking heater 12 is arranged so as to surround the temperature sensor 11. A removable inner pot (rice cooker) 13 is housed in the inner container 8. When the inner pot 13 is properly stored in the inner container 8,
The outer bottom surface contacts the temperature sensor 11 and the rice cooking heater 12, the bottom surface is heated by the rice cooking heater 12, and the temperature of the central portion of the bottom surface can be detected by the temperature heater 11.

The lid unit 2 includes an outer lid 14 formed of synthetic resin or the like, a pot lid 15 detachably attached to the outer lid 14 on the inner surface side of the outer lid 14, and a pot lid 15 made of metal, for example. The pressure adjusting port 16 incorporated in the lid 14 is provided. The pan lid 15 is for covering the inner pan 13. The lid unit 2 is detachably attached to the arm 17 provided on the rear shoulder member 9. Arm 17
Are connected to the shoulder member 9 by a hinge mechanism including a hinge pin 18 and a spring (not shown). Therefore, the lid unit 2 attached to the arm 17 can be opened and closed with respect to the main body 1 as described above. Then, when the lid unit 2 is closed, the tip portion thereof is engaged with the push button 3 provided on the main body 1 side to be closed. When the push button 3 is pushed, the lid unit 2 is automatically opened by the force of a spring (not shown) of the hinge mechanism.

A heat-retaining heater 20 is provided around the outside of the inner container 8 so that the inner pot 13 can be steamed from the periphery of the side surface or heated for keeping heat through the inner container 8. Also,
A shoulder heater 21 is incorporated in the shoulder member 9. The shoulder heater 21 is arranged so as to come into contact with the edge portion of the pan lid 15, and heats the pan lid 15 by heat conduction, so that the pan lid 1
The purpose of this is to evaporate the water droplets generated on the surface of No. 5 and prevent the water droplets from falling into the inner pot 13.

Further, a heat insulating material 22 is arranged between the inner container 8 and the cover member 7, and the inner container 8 and the inner pot 13 are provided.
The heat radiation from is prevented. Further, between the heat insulating material 22 and the cover member 7, there are provided a control circuit board 23 for controlling rice cooking, heat retention control, timer control, etc. in the electric rice cooker and a power supply circuit board 24 for power supply. It is housed. Control circuit board 23, power supply circuit board 24
Is a temperature sensor 11, a rice cooking heater 12, and a heat retention heater 2.
0, the shoulder heater 21, the display 5 and the operation button 6 are electrically connected.

FIG. 3 is a block diagram showing a configuration relating to an electric control circuit of the electric rice cooker described above. This electric rice cooker has a microcomputer 25 as a control center.
Is provided. The operation signal of the operation button 6 and the temperature detected by the temperature sensor 11 are given to the microcomputer 25. The microcomputer 25 switches the display contents of the display device 5 based on these input signals, and controls the energization of the rice cooking heater 12, the warming heater 20 and the shoulder heater 21.

FIG. 4 is a graph showing changes in the bottom temperature of the inner pot 13 during the rice cooking operation, with the horizontal axis representing time and the vertical axis representing temperature. The rice cooking operation includes a preheating step for raising the inner pot 13 to a predetermined temperature (for example, about 40 ° C.), a water supply step for allowing the rice to absorb water at the predetermined temperature after preheating, and rice and water in the inner pot 13. It includes a first cooking process for heating the rice to a boiling state, a second cooking process for maintaining the boiling condition until the water in the inner pot 13 is exhausted, and a steaming process for steaming the cooked rice.

Of these, when the first cooking process is completed, the bottom temperature of the inner cooking pot 13 is about 107 ° C., and in the first half of the second cooking process, since there is water in the inner cooking pot 13, The bottom temperature does not rise above about 107 ° C. Then, in the latter half of the second cooking process, the water content in the inner pot 13 starts to disappear, and only the cooked rice (solid) is heated, so that the temperature rises.

The temperature sensor 11 detects the thus changing bottom temperature of the inner pot 13. Microcomputer 2
5 controls energization to the rice cooking heater 12 based on this detected temperature. However, when the inner pot 13 is not completely stored and the rice cooking heater 12 is not in proper contact with the bottom surface of the inner pot 13, the temperature sensor 11 can accurately detect the bottom temperature of the inner pot 13. Disappear. Such a situation often occurs because rice grains and other foreign matter adhere to the bottom of the inner pot 13. In such a case, the bottom part temperature change of the inner pot 13 during rice cooking is, for example, the one-dot chain line or 2 in FIG.
It becomes as shown by the dotted line. That is, the temperature at the end of the first cooking process increases according to the degree of adhesion of foreign matter.

For example, when making cooked rice,
Salt content is added to the cooked rice contents, and the boiling temperature becomes relatively higher than in the case of cooked rice. Therefore, also in this case, the temperature change of the bottom portion of the inner pot 13 during rice cooking is as shown by, for example, a two-dot chain line in FIG. The features of the electric rice cooker according to this embodiment are that when the inner pot 13 is not properly in contact with the rice cooking heater 12 due to the adhesion of foreign particles such as rice grains, or when the rice containing contents such as cooked rice is cooked, Set the cooking temperature of relatively high temperature compared to normal rice cooked rice,
It controls to automatically cook delicious rice.

In the conventional electric rice cooker, rice grains and other foreign substances adhere to the bottom of the inner pot 13, so that the detected temperature at the completion of the first cooking step is the normal temperature (about 107).
When the temperature becomes higher than (.degree. C.), for example, when it reaches about 130.degree. Figure 5
And FIG. 6 is a flowchart showing an example of rice cooking control performed by the microcomputer 25 in the electric rice cooker according to this embodiment. Next, the rice cooking control operation will be described according to the flow of FIGS. 5 and 6.

When the control is started, first, preheating and water supply strokes are performed (step S1). As described above, this preheating and water supply process is a process in which the bottom temperature of the inner pot 13 is raised to, for example, about 40 ° C., and in that state, the rice is allowed to absorb water for a certain period of time. When the water supply process is completed, the rice cooking heater 12
Is turned on (step S2), and the first cooking process starts. Then, in the middle of the first cooking process, the sum is judged (step S3). As a method of determining the sum, for example, the method disclosed in Japanese Patent Application No. 2-290014, which is the applicant's prior application, is used. Briefly, first
During the course of the cooking process, when the temperature detected by the temperature sensor 11 reaches, for example, 71 ° C., clocking is started and the rice cooking heater 12 is energized at 100% (for example, in the case of duty control, energization with a duty ratio of 1). . Then, for example, based on the temperature detected by the temperature sensor 11 after 4 minutes have passed, the sum is judged, that is, the amount of cooked rice stored in the inner pan 13 is judged.

After determining the amount of cooked rice, the rice cooking heater 12 is energized according to the determined amount of cooked rice (step S).
4). The control up to this point is the same as the control in the electric rice cooker using the conventional microcomputer. Next, the temperature detected by the temperature sensor 11 is the first temperature.
It is determined whether or not the boiling temperature has reached 105 ° C. (step S5). In the case of normal cooked rice, boiling starts when the inner pot 13 reaches 105 ° C. Therefore, the temperature detected by the temperature sensor 11 is the boiling temperature 1 which is the first temperature.
When the temperature reaches 05 ° C, the microcomputer 25
A predetermined time of, for example, 300 seconds is started (step S6). The time counting process by the microcomputer 25 may be performed by a timer using software, or may be performed by a timer having a hardware timer built therein. And in advance
It is observed whether 300 seconds, which is the predetermined time counting time, has elapsed or whether the temperature detected by the temperature sensor 11 reaches a second predetermined temperature, for example, 110 ° C (steps S7, S).
8). It is needless to say that the electric power according to the rice cooking use determined in step S4 is continuously supplied to the rice cooking heater 12 during this period.

The temperature detected by the temperature sensor 11 is predetermined.
If it is observed that the timer has finished measuring 300 seconds before the temperature reaches 110 ° C., which is the second temperature (YES in step S7).
S), in response to the second temperature not being reached,
Energization control for normal rice cooking is performed on the rice cooking heater 12.
That is, the energization control of the rice cooking heater 12 is performed until the temperature detected by the temperature sensor 11 reaches, for example, 130 ° C. (step S9). That is, the cooking temperature is 13
0 ° C is set. And the detected temperature is 13
When the temperature reaches 0 ° C., the power supply to the rice cooking heater 12 is interrupted and the steaming process is started (step S10).

In the steaming process, the power supply to the rice cooking heater 12 can be switched to a power supply necessary and sufficient for steaming. On the other hand, after the start of timing in step S6, 3
The temperature detected by the temperature sensor 11 is predicted before 00 seconds has elapsed.
When the temperature reaches 110 ° C., which is the second temperature to be determined (YES in step S8), the temperature detected by the temperature sensor 11 falls within this range.
When the second temperature of 110 ° C. is exceeded, the time counting operation is stopped and the time measured by the timer is determined (steps S11 and S13). In other words, it is the predetermined time
The detected temperature is the second temperature before 300 seconds are counted.
In response to reaching 110 ℃
12, the first temperature is 105 ° C. to the second temperature.
For special cooking depending on the time it takes to reach 110 ℃
Energization control is performed. When foreign matter such as rice grains adheres to the bottom of the inner pot 13 or foreign matter exists on the rice cooking heater 12, or when cooking cooked rice other than white rice, the size of the foreign matter and the content of cooked rice ( For example, the time required for the detected temperature to reach the second temperature of 110 ° C. varies depending on the saltiness. Generally speaking, the larger the foreign matter or the higher the salt concentration, the faster the temperature rises and the shorter the time until the detected temperature reaches 110 ° C. Therefore, in this embodiment, the detected temperature is preset from the first temperature of 105 ° C. to the second temperature.
When the time required to rise to 110 ° C. is relatively long (200 seconds to 300 seconds), the cooking temperature is set to 135 ° C. (step S12). When the temperature rise is moderate (100 seconds to 199 seconds), the cooking temperature is set to 140 ° C (step S14). Furthermore, when the temperature rise is very fast (0 to 99 seconds), the cooking temperature is set to 145 ° C. (step S15) . As a result, even if foreign matter is present between the inner pot 13 and the rice heating heater 12, or even in the case of special rice other than rice cooked with white rice, that is automatically detected and the cooking temperature is corrected, and it is always You can cook delicious rice. Especially, the inner pot 13 and the rice cooker 1
Even if there is a foreign substance sandwiched between the two, it is possible to prevent the rice from being cooked raw or the rice with the core being cooked up.

It should be noted that the present invention cooks delicious rice even when foreign matter is attached between the inner pot and the rice-cooking heater, or in cases other than rice cooked with white rice. With this configuration, the rice cooker 12 is not energized even when the rice cooker forgets to put the rice cooker in the inner pot 13 or the rice is cooked in an abnormal state. Such empty rice cooking, abnormal rice cooking, and rice cooking targeted by the present invention are
The distinction is made by setting the set temperature in step S8 to 110 ° C., for example. That is, the temperature of 110 ° C. is a set temperature for detecting foreign substances of a predetermined size or smaller between the inner pot 13 and the rice cooking heater 12 or for detecting cooked rice other than white rice cooked rice. Is.

7 and 8 are flow charts showing another rice cooking control operation of the electric rice cooker according to this embodiment. Next, according to the flowcharts of FIGS. 7 and 8,
Another rice cooking control operation of the electric rice cooker according to this embodiment will be described. When the control process is started, preheating and water supply are performed (step S21), the rice cooking heater 11 is turned on (step S22), and a summation determination is performed during the first rice cooking process (step S23), depending on the amount of cooked rice. Electric power is supplied to the rice cooking heater 12 (step S24). The control up to this point is exactly the same as steps S1 to S4 shown in FIG.

Next, the temperature detected by the temperature sensor 11 is preset.
It is observed whether or not the boiling temperature of 100 ° C., which is the first temperature to be determined, has been reached (step S25). Usually, the temperature detected by the temperature sensor 11 at the time of cooking is at a first temperature Ri boiling der Water
The contents of the still inner bowl 13 even at some 100 ° C. is not boiling, as described in place of step S5 in FIG. 5, the contents when the detected temperature reaches for example 105 ° C. begins boiling To do. In the control of FIG. 7 , the contents are actually
There first temperature to determine a temperature 100 ° C. of the temperature below the boiling advance
And the temperature is set to the rice cooking content detection start temperature. Then, when it is determined that the temperature detected by the temperature sensor 11 has reached 100 ° C. (YES in step S25), the timer is started (step S26) and, for example, counting of 200 seconds is started. Then, when 200 seconds have been measured (YES in step S27), the temperature detected by the temperature sensor 11 is read (step S28), and the cooking temperature is set based on the level of the read detected temperature.

More specifically, the detected temperature is the second temperature.
When it is observed to be 108 below ℃ that (YES in step S29), the foreign matter is not interposed between the inner bowl 13 and the cooking heater 12, and is determined to be the normal rice cooking, 130 After the cooking temperature of ℃ is set , cooked rice after that.
The heater 12 is energized for normal rice cooking
Then, the cooking process for ordinary rice is performed until the cooking temperature is reached (step S30). On the other hand, when the detected temperature exceeds the second temperature of 108 ° C. and is 115 ° C. or lower (YES in step S31), the cooking temperature is set to 135 ° C. and the cooking process is performed until the temperature is reached. (Step S32).

Further, the detected temperature is the second temperature 115.
If the temperature exceeds ℃ and is 122 ℃ or less (Y in step S33
ES), the cooking temperature of 140 ° C. is set, and the cooking process is performed until the cooking temperature is reached (step S3).
4). Furthermore, when the detected temperature exceeds the second temperature of 122 ° C., the cooking temperature is set to 145 ° C., and the cooking process is performed until the temperature is reached (step S35). In this way, the detected temperature is determined in advance.
When the temperature is above the temperature, the detected temperature will be detected by the rice cooking heater 12 thereafter.
Energization control for special rice cooking is performed according to the degree.

When each cooking temperature is reached,
The cooking process is completed and the steaming process is performed (step S36). As described above, in the control shown in FIGS. 7 and 8, the temperature detected by the temperature sensor 11 is set to the first temperature determined in advance .
Certain rice cooking content detection start temperature (100 ° C. in this embodiment)
The corresponding cooking temperature is set on the basis of the temperature increase for a certain time (200 seconds in this embodiment). This is the feature of this control. Incidentally, rice content detection starting temperature, which is the first temperature in step S25 is not a temperature below the boiling temperature, boiling AgaAtsushi degree itself, for example may be set to 105 ° C..

By changing the cooking temperature based on the temperature rise within a certain period of time, even if there is a foreign substance between the inner pot 13 and the rice cooking heater 12, or the cooked rice other than the white rice cooked rice is cooked. Even in such cases, you can always cook delicious rice, and it will not be raw rice or rice with core as in the past. This invention
In addition to the specific examples described above, control may be performed by changing the rice cooking content detection start temperature, and various changes may be made within the technical scope described in the claims. is there.

[0034]

EFFECT OF THE INVENTION The present invention is constructed as described above, and foreign matter is caught between the inner pot and the rice cooking heater.
Even for cooked rice other than rice cooked with white rice , the boiling temperature
Cook until the temperature reaches a certain value, and the temperature detected by the temperature sensor is set in advance.
After that, in response to the boiling temperature,
Performing energization control corresponding to the detected temperature contrast, since the normal cooking and to set different cooking raised temperatures, can be cited cook your have <br/> correct rice.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external configuration of an electric rice cooker according to an embodiment of the present invention.

FIG. 2 is a schematic sectional structural view taken along the line AA of FIG.

FIG. 3 is a block diagram showing a configuration of an electric control-related circuit of the electric rice cooker according to the embodiment of the present invention.

FIG. 4 is a graph showing changes in detected temperature during a rice cooking operation of the electric rice cooker according to this embodiment.

FIG. 5 is a flowchart showing an example of rice cooking control operation of the electric rice cooker according to this embodiment.

FIG. 6 is a flowchart showing an example of rice cooking control operation of the electric rice cooker according to the embodiment.

FIG. 7 is a flowchart showing another rice cooking control operation of the electric rice cooker according to this embodiment.

FIG. 8 is a flowchart showing another rice cooking control operation of the electric rice cooker according to this embodiment.

[Explanation of symbols]

 1 Rice Cooker Main Body 2 Rice Cooker Lid Unit 5 Indicator 11 Temperature Sensor 12 Rice Cooker 13 Inner Pan 25 Microcomputer

Claims (2)

[Claims] 1. An electric rice cooker for heating rice by heating the inner pot with a rice cooking heater, wherein a temperature sensor for detecting the inner pot temperature and the temperature detected by the temperature sensor cause the contents of the inner pot to boil. A timer means for starting timekeeping when the first temperature is reached, and a timer for counting a predetermined time by the timer means, or a predetermined second temperature in which the temperature detected by the temperature sensor is higher than the boiling temperature which is the first temperature. observing whether reaching temperature, the advance
During the time counting to determine, in response especially not reach the second temperature, thereafter, the plain cooking control means for energization control for ordinary rice against rice heaters, to measure a period of time counting means predetermined Or observing whether the temperature detected by the temperature sensor reaches a predetermined second temperature higher than the boiling temperature which is the first temperature , and the detected temperature is the second temperature before the predetermined time is measured. In response to reaching the
An electric rice cooker, comprising: a special rice control unit that controls energization for the special rice according to the time from the temperature to the second temperature. 2. A heating the inner pot by cooking heater electric cooker that performs cooking, boiling temperature sensor for detecting the inner bowl temperature, the temperature detected by the temperature sensor is a first temperature the predetermined
Counting means to start time counting in response to become temperature, when the counting means has counted a predetermined time, detects the temperature of the temperature sensor, when less than the second temperature detected temperature predetermined, thereafter, Normal rice cooking control means for controlling the electricity for normal rice cooking to the rice cooking heater, and when the detected temperature is equal to or higher than a predetermined second temperature, the electricity is supplied to the rice cooking heater for special rice according to the detected temperature. An electric rice cooker characterized by including special rice cooker control means for controlling.