JPH07108255B2 - Heating control device for rice cooker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating control device for a rice cooker, which makes it possible to match the time required for the inside of a pot to reach a predetermined target temperature with an optimum temperature known from experience. As a result, high quality cooked rice can be cooked.

[0002]

2. Description of the Related Art As a rice cooker in which high-quality cooked rice can be cooked by devising a heating method, there is, for example, one shown in FIG. Gas burner (2) for heating the kettle (1)
An on-off valve (3) is inserted in the gas circuit to the, and the on-off valve (3) is controlled to be opened and closed by a heating control circuit (30) incorporating a microcomputer or the like. As shown in FIG. 8, all the steps of cooking rice include a preheating step (A), a rice cooking heating step (B), and a steaming heating step (C) arranged in time series. (A) adjusts the water content of the rice grains to an appropriate value, the cooked rice heating step (B) actually cooks the cooked rice, and the steaming and heating step (C) steams the cooked rice.

In the preheating step (A), the inside of the kettle (1) is heated and kept at a constant temperature (usually 45 ° C.) for a preheating time set to about 20 minutes, so that an appropriate water content in the rice grain can be obtained. Secure. In the cooking rice heating step (B), the gas burner (2) is burned in a high heat state until the temperature in the kettle (1) detected by the temperature sensor (31) rises to 125 ° C. Evaporate. After that, the inside of the kettle (1) is 1
The gas burner (2) is burned in a low heat state until the temperature is raised to 45 ° C. to finish the rice cooking step (B). After that, the pot (1)
When the steaming and heating step (C) in which the inside is kept warm for a certain period of time is executed, the whole rice cooking step is completed.

During the rice cooking process, the temperature control in the kettle (1) in the transition area from the preheating process (A) to the rice cooking heating process (B) has an important influence on the taste of cooked cooked rice. If the time from the completion of the preheating step (A) until the temperature in the kettle (1) reaches 98 ° C near the boiling point is limited to about 10 minutes (hereinafter, referred to as a time limit), a high tasting quality is obtained. Experience has shown that quality cooked rice can be cooked. This is because when the time until the temperature rises to about the boiling point is long, the amount of starch liquid called oneva generated from rice grains is small, and when the time is short, the amount of the starch liquid is large and the cooked rice increases. This is because the taste of the product is deteriorated. The present invention has been made in view of the above points, and it is possible to raise the temperature in the pot (1) to about the boiling point within the predetermined time limit from the start of the rice heating step (B). The task is to do.

[0005]

[Technical Means] The technical means of the present invention for solving the above-mentioned problems will be described with reference to the conceptual diagram shown in FIG. 6. The technical means of the present invention is that "a unit control operation is repeated n times. A unit control assigned to the unit control operation by raising the temperature in the kettle from the starting temperature T1 to the final temperature Tn, and dividing the time limit G given for the temperature raising operation by the control number n. The control operation is performed once in the unit control time g by obtaining the time g, and ((final temperature Tn-starting temperature T1) / control count n)
Temperature rise coefficient calculation means (13) for obtaining the temperature rise coefficient K determined by
Then, after detecting the actual kettle temperature h at the start of the i-th unit control operation, (starting temperature T1 + (temperature increase coefficient K ×
i) -a unit temperature increase means (14) for calculating a unit temperature rise Hi that needs to be raised in the container by the i-th control by calculating the temperature h) in the container; Temperature gradient calculating means for calculating the temperature gradient X1 of the pot temperature at the start of the i-th unit control operation by using the temperature difference between the pot temperature at the start of the i-th unit control action and a certain time period after this ( 15), and further, a correction coefficient calculation means (16) for calculating a correction coefficient X2 which is determined as a ratio of the temperature gradient X1 and the calculated temperature increase coefficient K corresponding to the temperature gradient X1. The unit heating temperature Hi that needs to be raised is corrected by the correction coefficient X2, and the i-th heating control is performed ”.

[0006]

The above technical means operates as follows. The temperature inside the kettle is set to the final temperature T by repeating the unit control operation n times.
In addition to being able to raise the temperature to n, the unit control operation can be executed by spending a unit control time g obtained by dividing a predetermined time limit G by the control number n. There is. Therefore, when the unit control operation is repeated n times and all the control operations are completed, the time limit G
And the temperature in the pot reaches the final temperature Tn by the action described below.

First, the temperature increase counting calculation means (13) has a starting temperature T1 before the start of control and a final temperature T to be increased.
By dividing the difference of n by the preset number of times of control n, the temperature rise coefficient K required to raise the temperature in the pot by the unit control operation is calculated. That is, if the temperature inside the kettle can be raised by the temperature increase coefficient K for each unit control operation, the temperature inside the kettle will reach the final temperature Tn when all the n times of control are completed. It will be.

However, in each actual unit control operation,
Because of the fact that the amount of cooked rice is not constant, the temperature inside the kettle cannot be accurately raised so as to meet the above-mentioned calculated temperature rise coefficient K, and a temperature error occurs. Therefore, in order to prevent the temperature error from accumulating for each unit control, the unit rising temperature is calculated in consideration of the temperature error. That is, the i-th (i =
1 to n), when the unit control operation is started, the actual kettle temperature h at this point is measured, and then the calculation of (starting temperature T1 + (temperature increase coefficient K × i) −cook pot temperature h) is calculated. The unit rising temperature calculation means (14) executes and finds the rising temperature Hi.

Then, the unit rising temperature calculating means (1
(Starting temperature T1 + (temperature increase coefficient K × i)) in the equation executed by 4) is a calculation that the inside of the kettle (1) should reach when the i-th unit control operation is completed. It shows the temperature, and the unit rise temperature Hi obtained by subtracting the actual kettle temperature h at the start of the i-th unit control operation from the calculated temperature.
Is taken into consideration so as to eliminate the temperature error caused by the progress of the unit control operation (i-1th control operation) before that. That is, if the inside of the pot can be heated and raised by the unit rising temperature Hi during the i-th unit control operation, the temperature error before that can be absorbed when the i-th unit control operation is executed. It will be.

On the other hand, the temperature gradient calculation means (15) calculates the temperature gradient X1 in the kettle at the start of the i-th unit control operation, and further the temperature gradient X1 and the calculated temperature rise corresponding thereto. The correction coefficient calculating means (16) calculates the ratio of the coefficient K (correction coefficient X2). When the previous temperature gradient X1 (actual temperature gradient) tends to be excessively higher than the value of the corresponding calculated temperature increase coefficient K, the residual heat of the kettle (1) having a large heat capacity is transferred to the kettle (1). Therefore, the temperature inside the kettle during the i-th unit control operation may be excessively increased due to the influence of the excessive temperature increase tendency, and the correction coefficient X2 is calculated to correct this.

The unit rising temperature Hi, which is to be raised during the i-th unit control operation, is corrected by the correction coefficient X2.
The temperature of the inside of the kettle (1) is accurately raised by performing the heating operation of the kettle (1) while making a correction. After that, if the unit control operation is performed for all control times (n times), the inside of the shuttle (1) will be heated to the final temperature Tn when the time limit G is reached. example
For example , when the starting temperature of the rice heating step (B) is set as the starting temperature T1, the boiling point is set as the final temperature Tn, and the time limit G is set to 10 minutes, the inside of the pot (1) is set.
It is possible to accurately raise the temperature to the boiling point within the set time .

[0012]

[Effect] The present invention has the following unique effects. Take the desired time limit from the start of the rice heating process (B) to the boiling point
Because it can raise the temperature accurately , that is, the boiling
Accurate time required to heat up to the preset time limit
Therefore, the taste of cooked rice can be improved based on the above control.

[0013]

Embodiments of the present invention described above will now be described with reference to the drawings. The rice cooker of the embodiment of the present invention has a schematic configuration as shown in FIG. 1, and the outer surface of the pot (1) and the upper lid (11) are
Temperature sensor (31) (1) for detecting the temperature inside the kettle (1)
2) are brought into contact with each other. In the gas circuit to the gas burner (2) as a heating source, a first gas valve (22), a second gas valve (23) and a proportional valve (24) are arranged in this order from the upstream side. The circuit to the pilot burner (26) is branched from between the first gas valve (22) and the second gas valve (23). The valves are controlled by a control circuit (30) that determines the outputs of the temperature sensors (12) and (31), and the control circuit (30) further includes a rice cooking switch (10). ) The operation signal is applied.

The rice cooker is controlled by a control program stored in the microcomputer in the control circuit (30), and the control program is as shown in the flow chart of FIG. Hereinafter, the entire heating process performed by the rice cooker of this embodiment will be described with reference to FIG. <About the preheating step (A)>. First, the operation of the rice cooking switch (10) is monitored, and when the rice cooking switch (10) is operated, the preliminary heating step (A) is executed. That is, by opening the gas valves (22) and (23) and igniting the gas burner (2), and then controlling the combustion operation of the gas burner (2), the temperature inside the kettle (1) is controlled. First pre-cooking step (A1) of maintaining at 30 ° C. for 3 minutes (see step (61))
After performing the above, the second precooking step (A2) (see step (62) in the drawing) of maintaining the temperature in the kettle (1) at 36 ° C. for 17 minutes is performed.

<Rice cooking heating step (B)> In the rice cooking heating step (B), as shown in FIG. 3, the temperature inside the pot (1) is raised to 98 ° C. near the boiling point in 10 minutes. Cooking process (B1) and subsequent second cooking process (B2)
(See FIG. 3), the first cooking step (B1) further includes a first heating step (B11) for heating the temperature in the kettle (1) to 70 ° C. in 7 minutes, and 3 7 in minutes
Second temperature raising step (B12) of raising the temperature from 0 ° C to 98 ° C
It consists of Further, in the rice cooking heating step (B), fuzzy control is executed so as to determine and evaluate both the unit rising temperature Hi and the correction coefficient X2, which will be described later, to determine the optimum combustion amount of the gas burner (2). Has become.
The present invention is adapted to be used when the above-mentioned rice cooking heating step (B) is executed. Next, the details of the rice cooking heating step (B) will be described with reference to FIG. 2 and the like.

.. When the preheating step (A) is completed, the opening of the proportional valve (24) is set to about 1/8 of the fully opened state, the gas burner (2) is burned, and this state is maintained for 1 minute. 63) (see step 64)). ． The current temperature h inside the kettle detected by the temperature sensor (12) attached to the upper lid (11) is stored in the initial temperature memory h0 (see step (65) in the drawing). The temperature stored in the initial temperature memory h0 corresponds to the starting temperature T1 described in the above-mentioned technical means.

.. Next, gas burner (2) at 10 second intervals
Control is performed to raise the temperature in the kettle (1) to 70 ° C. in 6 minutes (36 times) while changing the combustion amount of. Therefore, the temperature rise coefficient K = (70 ° C.−h0) / 36 (“36” is the number of combustion control times of the gas burner (2) executed at intervals of 10 seconds in 6 minutes) is calculated. As a result, the temperature rise coefficient K, which is the temperature that needs to be raised by one-time control (10 seconds), is calculated.
Further, the control frequency i is set to "1", and the initial temperature gradients Y0 and Y1 necessary for correcting the combustion amount of the gas burner (2) are both set to "h0" (see reference numeral (66)). See step).

.. Next, the target temperature Q for increasing the temperature in the kettle (1) by the i-th control is set to the detected temperature of the temperature sensor (12) attached to the upper lid (11), the temperature rise coefficient K, and the like. Use and calculate. That is, the target temperature Q = the temperature stored in the initial temperature memory h0 + the temperature increase coefficient k × i is calculated (see step (67) in the drawing).

.. When the target temperature Q is calculated, the difference between the actual kettle temperature h detected by the temperature sensor (12) and the target temperature Q is calculated, whereby the i-th combustion control continues for 10 seconds. In the meantime, the unit rising temperature Hi that needs to raise the temperature inside the kettle (1) is calculated. That is, the unit rising temperature Hi = the temperature h in the kettle-the target temperature Q is calculated (see step (68) in the drawing). Then, as shown in the enlarged view (FIG. 4) of the temperature in the kettle (1) during the execution of the first temperature raising step (B11),
The unit rise temperature Hi as the difference between the actual kettle temperature h and the target temperature Q is obtained.

[0020]. Next, the pot temperature h detected by the temperature sensor (12) is stored in the pot temperature memory Yn which stores the pot temperature at the initial stage of the i-th control. That is, the first time (i =
The temperature h in the kettle detected by the temperature sensor (12) at the beginning of the control of 1) is stored in the first kettle temperature memory Y1 in the second time (i).
= 2), the temperature h in the kettle detected by the temperature sensor (12) is detected in the second kettle temperature memory Y2, and the temperature detected by the temperature sensor (12) is detected in the beginning of the i-th control. The internal temperature h is sequentially stored in the i-th kettle temperature memory Yn.

[0021] Then, the _(Y n _{-Y n-2)} by the operation of, and the shuttle within the temperature h in the pot (1) at the time of performing the control of the i-th, the two previous (i-2 The actual temperature change L1 of the kettle (1) is calculated by taking the difference in the kettle internal temperature h during the (second) control. Then, this is divided by 2 to calculate the temperature gradient X1. Then, the temperature gradient X1 shows the average of the temperatures actually increased in the kettle (1) by the control in the previous two times, and the temperature of the gas burner (2) at the present time (during the i-th control) is shown. When the combustion amount is maintained as it is, it can be inferred that the temperature inside the kettle (1) is increased by the temperature gradient X1 when the next (i + 1) th control is completed. Further, since the temperature in the kettle (1) to be heated by the next i + 1-th control is the temperature rising coefficient K, the ratio of the two is taken and "correction coefficient X2 = temperature gradient X1 / temperature rising" The coefficient "K" is calculated (see step of drawing code (70)). That is, when the temperature gradient X1 and the temperature increase coefficient K match (when the actual temperature change in the kettle (1) matches the calculated temperature temperature increase coefficient K), The correction coefficient X2 is "1".

.. Next, the work of correcting the combustion amount of the gas burner (2) is performed from the unit rising temperature Hi and the correction coefficient X2 obtained in the above steps "" and "". Figure 7
A matrix for searching the correction amount of the combustion amount of the gas burner (2) from the combination of the unit rising temperature Hi and the correction coefficient X2, and this matrix is stored in the microcomputer of the control circuit (30). When the unit temperature rise Hi calculated in the above step "" is maximum, it is necessary to considerably increase the combustion amount of the gas burner (2). or,
Even when the correction coefficient X2 is the minimum, it is necessary to considerably increase the combustion amount of the gas burner (2). Therefore, when the unit rising temperature Hi is maximum and the correction coefficient X2 is minimum (when it is necessary to greatly increase the combustion amount of the gas burner (2)), "Hi;maximum" and "X2;minimum" in FIG. "+ Large" specified by "is selected in the microcomputer,
The combustion amount of the gas burner (2) is greatly increased.

Further, even if the unit rising temperature Hi is maximum,
When the correction coefficient X2 is "small" or "appropriate", "+ small" is selected from the matrix in the figure, and the combustion amount of the gas burner (2) is increased by a small amount. Further, even if the unit rising temperature Hi is maximum, the correction coefficient X2
Is "large" or "maximum", that is, the pot (1)
In the case where the temperature rise gradient in the inside is large and the correction coefficient X2 requires the combustion reduction of the gas burner (2), "0" is selected from the matrix of the figure, and the combustion amount of the gas burner (2) is the current state. Maintained. Then, the control is executed in the step portion of the reference numeral (71) in FIG. Incidentally, FIG.
In the above, "-small" and "-large" respectively indicate "slightly small" and "substantially small" the combustion amount of the gas burner (2). When the combustion amount of the gas burner (2) is corrected as described above, this state is maintained for 10 seconds (see step (72) in the drawing), and it is continuously determined whether i has reached 36 times. And the i
When the value is 36 or less, the value of i is increased by "1" and the control is returned to the step of the drawing code base (67) for calculating the target temperature Q (drawing code (72) (73). ) See step).

In this way, control is performed 36 times at intervals of 10 seconds, and while the combustion amount of the gas burner (2) is being corrected, 7 minutes after the start of the first temperature raising step (B11), the inside of the kettle (1) Raise the temperature to 70 ° C. As a result, the first temperature raising step (B11) is completed.

[0025]. Next, the instrument control is the second temperature raising step (B12) of raising the temperature in the kettle (1) to 98 ° C. in 3 minutes.
First, the present time t is stored in the steaming time memory (T) necessary for determining the steaming time described later. Also, the proportional valve (24) is maintained in a half-open state and the gas burner (2) is burned for 30 seconds (see the drawing reference numeral (75)).
See step).

.. Next, set the combustion amount of the gas burner (2) to 1
By controlling at 0 second intervals for 2 minutes and 30 seconds (15 times in total), the temperature inside the kettle (1) is finally raised to 98 ° C. Therefore, the same control as in the first temperature raising step (B11) is performed. The steps indicated by the reference numerals (77) to (83) are executed. On this platform, temperature rise coefficient K = (98 ° C.-pot temperature h0)
The control is performed in the same manner as in the first temperature raising step (B11) except that it is calculated / determined as / 15 (total number of control times) and that the maximum value of i is "15". As a result, the first cooking step (B1) including the first heating step (B11) and the second heating step (B12) is completed, and the cooked rice heating step (B)
The process of the first cooking step (B1) of raising the temperature inside the kettle (1) to 98 ° C. is completed in 10 minutes from the start of. That is, the first temperature raising step (B11) is completed in 7 minutes and the second temperature raising step (B12) is completed in 3 minutes.
The first cooking step (B11) is executed by spending 0 minutes.

In this embodiment, the present invention is separately applied to the first and second temperature raising steps (B11) and (B12), and the steps indicated by reference numerals (66) and (77) are executed. The part to do corresponds to the temperature rise coefficient calculating means (13) described in the section of technical means. Further, a portion for executing the steps of the drawing numerals (67) and (68) and (78) and (79) corresponds to the unit rising temperature calculating means (14) described in the section of technical means, and The portion for calculating the temperature gradient X1 executed at the codes (70) and (80) is the temperature gradient calculating means (1) described in the section of the above-mentioned technical means.
5), and further, the drawing codes (70) (8
The portion for calculating the correction coefficient X2 in the step 0) corresponds to the correction coefficient calculation means (16). Further, "36 times" is adopted as the control number n in the first temperature raising step (B11), and "15 times" is adopted as the control number n in the second temperature raising step (B12). As the unit control time g, the first and second temperature raising steps (B11)
(B12) Both “10 seconds” are adopted. And
In the above embodiment, the temperature in the pot (1) may be raised to 98 ° C. all at once by repeating the control 60 times at 10 second intervals from the initial temperature of the rice cooking heating step (11). In this case, "10 seconds" corresponds to the unit control time g, and "60 times" corresponds to the control number n described in the technical means section.

[10]. Next, the appliance control shifts to the second cooking step (B2), the proportional valve (24) is fully opened to burn the gas burner (2), and thereby the kettle (1) detected by the temperature sensor (31). Cook the rice in the rice cooker until the temperature of the bottom wall reaches 125 ℃ (drawing code (85),
See step (86)).

[11]. Next, when the proportional valve (24) is adjusted to a half open state and the temperature in the kettle (1) detected by the temperature sensor (31) reaches 145 ° C., the first gas valve (22) (2)
3) is closed to extinguish the gas burner (2), thereby completing the step of cooking rice heating step (B) (see steps (87) and (88) in the drawing). After that, the pot (1)
After the step of drawing reference numeral (89) for executing the steaming and heating step (C) for keeping the inside at the steaming temperature (usually 96 ° C. to 98 ° C.) is performed and the first temperature raising step (B11) is finished. It is determined whether or not 20 minutes have elapsed (see step (90) in the drawing), and if the time has elapsed (when cooked rice is alpha-ized), an alarm indicating that rice has been cooked is sounded. And complete the whole rice cooking process.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a rice cooker according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control program.

FIG. 3 is a graph showing the temperature inside the pot (1) when cooking rice.

FIG. 4 is an enlarged view of a main part of FIG.

FIG. 5 is a matrix showing control rules used for fuzzy control.

FIG. 6 is a conceptual diagram of the present invention.

FIG. 7 is an explanatory diagram of a conventional example.

FIG. 8 is an explanatory diagram of a conventional example.

[Description of References] (1) ... Kettle (13) ... Temperature rising coefficient calculation means (14) ... Unit heating temperature calculation means (15) ... Temperature gradient calculation means (16) ... Correction coefficient calculation means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuki Shoda, 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Within Osaka Gas Co., Ltd. (72) Inventor Michinori Shimotake, Hirano-cho, Chuo-ku, Osaka 4-1-2 No. 1 in Osaka Gas Co., Ltd. (56) Reference JP-A-2-277419 (JP, A) JP-A-59-155222 (JP, A) JP-A-62-186819 (JP, A)

Claims (1)

[Claims] 1. The temperature inside the kettle is raised from a starting temperature T1 to a final temperature Tn by repeating the unit control operation n times, and the time limit G given for this temperature raising operation is controlled as described above. A unit control time g assigned to a unit control operation is obtained by dividing by the number of times n, and one control operation is performed in the unit control time g.
Temperature rise coefficient calculation means (13) for obtaining a temperature rise coefficient K determined by ((final temperature Tn−starting temperature T1) / control count n),
After detecting the actual kettle temperature h at the start of the i-th unit control operation, (starting temperature T1 + (temperature increase coefficient K × i) −
A unit rise temperature calculation means (14) for calculating a unit rise temperature Hi that needs to raise the inside of the pot under the i-th control by calculating the pot temperature h), and the i-th unit Temperature gradient calculating means (1) for calculating the temperature gradient X1 of the pot temperature at the start of the i-th unit control operation by utilizing the temperature difference between the pot temperature at the start of the control operation and a certain time before this.
5), and further, a correction coefficient calculation means (16) for calculating a correction coefficient X2 which is determined as a ratio of the temperature gradient X1 and the calculated temperature increase coefficient K corresponding to the temperature gradient X1. Unit rising temperature Hi that needs to be raised
The heating control device of the rice cooker which performs the i-th heating control while correcting the above with the correction coefficient X2.