JPH0761B2 - Electric rice cooker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric rice cooker capable of keeping warm after completion of rice cooking.

2. Description of the Related Art Recent electric rice cookers are naturally required to be cooked well, and as a result, there is a demand for more delicious heat-retaining heat-retaining functions.

A conventional electric rice cooker of this type will be described with reference to FIGS. 10 and 11.

As shown in FIG. 10, a container 2 is provided with a lid 1 on the top for containing rice and water, and a bottom heater 3 for heating the bottom portion of the container 2.
And the body heater 4 for heating the side surface of the container 2, and the container 2
The temperature of the container 2 detected by the thermistor 5 is input from the thermistor 5 for detecting the temperature of the thermistor 5, and the signal from the thermistor 5 is input, so that the temperature of the container 2 detected by the thermistor 5 becomes a specified heat retaining temperature. The bottom heater 3 and the body heater 4 are each constituted by a control circuit board 6 which controls to energize or deenergize at a constant energization rate.

Next, the operation of the conventional electric rice cooker will be described with reference to the flowchart of FIG.

In FIG. 11, in step 10, the rice cooking process is performed. In step 11, the rice cooked in the container 2 is cooked and it is judged whether or not the rice cooking end temperature is reached and the rice cooking process is completed. If the rice cooking is not completed, the process returns to step 10 and steps 10 to 11 are repeated until the rice cooking is completed. repeat.

When the rice is cooked, proceed to step 12 and thermistor 5
Input the temperature of the container 2 by. Next, if the temperature does not reach the heat retention temperature (71.5 ° C) in step 13, step
In step 14, heating is controlled so that the body heater 4 and the bottom heater 3 reach the heat retention temperature. If the temperature exceeds the heat retention temperature, in step 15, the energization of the body heater 4 and the bottom heater 3 is stopped. After performing Step 14 and Step 15, return to Step 12. Steps 12 to 15 were repeated, and the temperature of the container 2 was controlled to be the heat retaining temperature, and the rice in the container 2 was kept warm.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a conventional electric rice cooker, when the lid 1 is opened and reclosed while the temperature is kept warm, the lid 1 is cold. There was a problem that the rice dropped on top and kept warm while containing a lot of water, and its shape collapsed and whitened.

The present invention is to solve the above problems, and its first object is to prevent dew from adhering to the inside of the lid on the upper part of the container and to keep the temperature of rice without deteriorating the taste and shape of rice. There is. The second purpose is to prevent dew from forming on the inside of the lid of the container even if the lid of the container is opened and then closed again. It is to keep the heat without deteriorating. A third purpose is to prevent dew from forming on the inside of the lid of the container even if the lid of the container is opened and then closed again. The purpose is to keep heat without deteriorating and to prevent the lid on the top of the container from being heated to a dangerous temperature.

Means for Solving the Problems In order to achieve the first object of the present invention, a bottom heater that heats a bottom portion of a container, a body heater that heats a side surface portion of the container, and an inside of a lid of the container are provided. A lid heater that heats the container, a temperature detection unit that detects the temperature of the container, and a control unit that inputs a signal of the temperature detection unit, the control unit having the temperature immediately after entering the heat retention process from the rice cooking process. The bottom heater, the body heater, and the lid heater are energized at a constant duty ratio so that when the detection means is below the specified heat retention temperature, the temperature is maintained, and when the specified heat retention temperature is exceeded, the bottom heater and the lid heater are connected. The first problem solving means is to stop the energization with the body heater and control the lid heater so as to reduce the energization rate.

Further, in order to achieve the second object, in addition to the first problem solving means, an opening / closing detection means for detecting the opening / closing of the lid of the container is provided, and the control means outputs signals of the temperature detection means and the opening / closing detection means. A second problem solving means is to input and increase the energization rate of the lid heater while the lid of the container is opened by the opening / closing detection means.

Further, in order to achieve the third object, in addition to the second problem solving means, a lid temperature detecting means for detecting the temperature inside the lid of the container is provided, and the control means includes the lid temperature detecting means and the temperature detecting means. A third problem solving means is to input a signal to the open / close detection means and stop the energization of the lid heater when the lid temperature rises above a specified temperature by the lid temperature detection means.

Effect The present invention, by the above-mentioned first problem solving means, after moving from the rice cooking step to the heat retaining step, the temperature of the container is detected by the temperature detecting means, and the lid heater is energized at a constant duty ratio below the heat retaining temperature, When the temperature exceeds the heat retention temperature, the energization is performed by lowering the energization rate, so that the inside of the lid on the top of the container is always heated, and it is possible to prevent dew from attaching to the inside of the lid.

In addition, by the second problem solving means, after the opening of the lid is detected by the opening / closing detection means after the rice cooking step is shifted to the heat retention step, the energization rate of the lid heater is increased to heat the inside of the lid and the lid is opened. Even if it is opened and then closed again, the temperature inside the lid is not lowered, and there is no condensation on the inside of the lid.

The third problem solving means detects the opening of the lid by the open / close detecting means and the lid temperature detecting means after the rice cooking step is shifted to the heat retaining step, and the energization rate of the lid heater is increased to increase the inside of the lid. When the lid temperature exceeds the specified temperature, the energization of the lid heater is stopped, and heating can be prevented until the lid temperature reaches a dangerous temperature.

Embodiment An embodiment of the first invention will be described below with reference to FIGS. 1, 2 and 3.

In FIG. 1, a lid 21 is provided on the top of the container 20, and rice and water are put in the container 20 to cook rice. The container 20 is provided with a bottom heater 22 for heating the bottom portion and a body heater 23 for heating the side portion, and the lid 21 is provided with a lid heater 24 for heating the inside of the lid 21. The temperature detecting means 25 detects the temperature of the container 20. The control means 26 inputs the signal of the temperature detecting means 25, and when the temperature detecting means 25 falls below the specified heat retaining temperature immediately after entering the heat retaining step from the rice cooking process, the bottom heater 22 and the body are adjusted so that the temperature becomes the heat retaining temperature. When the heater 23 and the lid heater 24 are each energized at a constant energization rate, and when the prescribed heat retention temperature is exceeded, the energization of the bottom heater 22 and the body heater 23 is stopped, and the lid heater 24
Control is performed so as to reduce the energization rate of.

Next, FIG. 2 is a specific circuit diagram. The start key 31 is for starting the rice cooking process, and the cancel key 32 is for canceling the rice cooking process and the heat retaining process. Temperature detection means (hereinafter referred to as the first
The thermistor) 25 detects the temperature of the container 20. The signal from the first thermistor 25 is A / D converted by the A / D converter 33. The relay 34 is a relay for energizing the bottom heater 22, and has a relay coil 34a and a relay contact 34b. The relay drive unit 35 drives the relay 34.
The relay 36 is a relay for energizing the body heater 23 and has a relay coil 36a and a relay contact 36b. The relay drive unit 37 drives the relay 36. The relay 38 is a relay for energizing the lid heater 24 and is a relay coil.
It has 38a and a relay contact 38b. The relay drive unit 39 drives the relay 38. The input unit 40 inputs signals from the start key 31, the cancel key 32 and the A / D converter 33. The output unit 41 outputs a relay opening / closing signal to each of the relay driving units 35, 37 and 39. The control unit 42 controls the output unit 41 according to the signal input from the input unit 40. The control means (hereinafter referred to as a microcomputer) 26 is composed of an input section 40, an output section 41 and a control section 42.

FIG. 3 is a flow chart showing the operation of the microcomputer 26. The operation will be described with reference to this flow chart.

In FIG. 3, the start key 31 is input in step 50, it is determined in step 51 whether the key pressed is the start key 31, and steps 50 to 51 are repeated until the start key 31 is pressed. If the start key 31 is pressed in step 51, the process proceeds to step 52 and the rice cooking process is executed. In step 53, it is judged whether or not the rice cooking process is completed. If the rice cooking is not completed, the process returns to step 52 and the steps are continued until the rice cooking is completed.
Repeat 52 to 53. If cooking is over, step 54
Proceeding to step 54, the temperature of the container 20 is detected by the temperature detecting means 25 in step 54, and if the bottom temperature does not reach the heat retention temperature (71.5 ° C) in step 55, the body heater 23 is set to 15/16 and the bottom heater 22 is set to step 56. 1/16, energize the lid heater 24 at a duty ratio of 8/16,
If the temperature exceeds the heat retention temperature, in step 57, the energization of the bottom heater 22 and the body heater 23 is stopped, and the lid heater 24 is set to 5/16.
Energize at the duty ratio of. After executing steps 56 and 57, the process proceeds to step 58 and waits for the input of the cancel key 32. Step
If it is not determined in 59 that the cancel key 32 has been pressed, the process returns to step 54, and steps 54 to 59 are repeated until it is determined in step 59 that the cancel key 32 has been pressed. If it is determined in step 59 that the cancel key 32 has been pressed,
Proceed to step 60, stop energizing all heaters, and return to step 50.

As described above, according to the electric rice cooker of the first embodiment of the present invention, after the rice cooking process is moved to the heat retaining process, the bottom heater 22, the body heater 23, and the lid heater 24 are heated and controlled at a constant energization rate, container
When the temperature of 20 exceeds the heat retention temperature, the energization rate of the bottom heater 22 and the body heater 23 is stopped, the energization rate of the lid heater 24 is reduced, and the inside of the lid 21 above the container 20 is constantly heated to keep the lid 21 It is possible to prevent the inside from being exposed to dew, and the temperature of the container 20 can be controlled to be a heat retention temperature.

Next, an embodiment of the second invention will be described with reference to FIGS. 4, 5, and 6. Note that the description of the same configuration as that of the embodiment of the first invention is omitted.

In FIG. 4, the opening / closing detection means 27 detects opening / closing of the lid 21 of the container 20. The control means 28 inputs signals from the temperature detecting means 25 and the open / close detecting means 27, and when the temperature detecting means 25 is equal to or lower than the prescribed heat retaining temperature immediately after entering the heat retaining step from the rice cooking process, the heat retaining temperature is set to this heat retaining temperature. Bottom heater 22 and body heater 23
The lid heater 24 and the lid heater 24 are energized at a constant energization rate, and when the temperature is over the specified temperature, the bottom heater 22 and the body heater 23 are de-energized, and the energization rate of the lid heater 24 is lowered. Further, while the lid 21 of the container 20 is opened by the opening / closing detection means 27, control is performed so as to increase the energization rate of the lid heater 24.

Next, FIG. 4 is a specific circuit diagram, and the opening / closing detection means (hereinafter referred to as opening / closing switch) 27 detects opening / closing of the lid 21 of the container 20. The input section 43 includes a start key 31, a cancel key 32 and A /
The signals from the D converter 33 and the open / close switch 27 are input. The output unit 44 outputs a relay opening / closing signal to the relay driving units 35, 37 and 39. The control unit 45 controls the output unit 44 according to the signal input from the input unit 43. The control means (microcomputer) 28 is composed of an input section 43, an output section 44 and a control section 45.

FIG. 6 is a flow chart showing the operation of the microcomputer 28. The operation will be described with reference to this flow chart.

In FIG. 6, the start key 31 is input in step 61, and the same operation as that of the embodiment of the first invention is repeated in steps 61 to 64, and if the rice cooking is completed, step
Proceeding to 65, the input of the open / close switch 27 is accepted. Next, in step 66, it is determined whether or not the lid 21 of the container 20 is opened, and if the lid 21 is opened, the lid heater 24 is continuously energized in step 67 and the process proceeds to step 68. Detects temperature. If the bottom temperature does not reach the heat retention temperature (71.5 ° C) in step 69, the body heater 23 in step 70.
15/16, the bottom heater 22 is energized at a duty ratio of 1/16, and if the temperature exceeds the heat retention temperature, the energization of the bottom heater 22 and the body heater 23 is stopped in step 71.

If the lid 21 of container 20 was closed in step 66, step
Proceeding to 72, the same operation as in the first embodiment of the invention is carried out in step 7
After performing steps 3, 74 and 75, the process proceeds to step 76 and waits for the input of the cancel key 32. If it is not determined in step 77 that the cancel key 32 has been pressed, the process returns to step 65, and steps 65 to 77 are repeated until it is determined in step 77 that the cancel key 32 has been pressed. When the cancel key 32 is pressed in step 77, the process proceeds to step 78, the energization of all heaters is stopped, and the process returns to step 61.

As described above, according to the electric rice cooker of the second embodiment of the present invention, after the rice cooking process is moved to the heat retaining process, the lid heater 24 is continuously energized when the lid 21 on the upper portion of the container 20 is opened, so that the lid 21 is opened. It is possible to prevent dew condensation on the inside of the lid 21 when the lid 21 is closed again by heating the inside of the container, and if the lid 21 is closed, the bottom heater 22, the body heater 23 and the lid heater 24 are heated and controlled to control the container. It can be controlled so that the temperature of 20 becomes the heat retention temperature.

Next, an embodiment of the third invention will be described with reference to FIG. 7, FIG. 8 and FIG. The description of the same configuration as that of the second embodiment will be omitted.

In FIG. 7, the lid temperature detecting means 29 detects the temperature inside the lid 21 of the container 20. The control means 30 inputs signals from the temperature detection means 25, the open / closed detection means 27 and the lid temperature detection means 29, and when the temperature detection means 25 is below the specified heat retention temperature immediately after entering the heat retention step from the rice cooking process, the heat retention temperature is maintained. So that the bottom heater 22, the body heater 23, and the lid heater 24 are energized at a constant energization rate, and when the temperature is higher than the specified heat retention temperature, the energization of the bottom heater 22 and the body heater 23 is stopped,
Control to reduce the duty ratio of 24. Further, while the lid 21 of the container 20 is opened by the opening / closing detection means 27, the lid heater 24
Is continuously energized, and the lid temperature is controlled by the lid temperature detecting means 29 to stop energizing the lid heater 24 when the lid temperature rises above a specified temperature.

Next, FIG. 8 is a specific circuit diagram, and the lid temperature detecting means (hereinafter referred to as the second thermistor) 29 detects the temperature of the lid 21 above the container 20. A / D signals from this second thermistor 29
A / D conversion is performed by the converter 46. The input unit 47 inputs signals from the start key 31, the cancel key 32, the A / D converter 33, the open / close switch 27, and the A / D converter 46. Output unit 48 is a relay drive unit
Outputs a relay open / close signal to each of 35, 37 and 39. The control unit 49 controls the output unit 48 according to the signal input from the input unit 47. The control means (microcomputer) 30 is composed of an input section 47, an output section 48 and a control section 49.

FIG. 9 shows a flowchart showing the operation of the microcomputer 30, and the operation will be described with reference to this flowchart.

In FIG. 9, the start key 31 is input in step 81, the same operation as that of the embodiment of the second invention is repeated in steps 81 to 84, and if the rice cooking is completed, step
Proceeding to 85, the input of the open / close switch 27 is accepted. Next, in step 86, it is determined whether the lid 21 of the container 20 is open. If the lid 21 is open, the lid temperature is detected by the lid temperature detecting means 29 in step 87, and the lid temperature is 120 in step 88.
If the temperature is not higher than ℃, the process proceeds to step 89, and the lid heater 24 is continuously energized. If the lid temperature exceeds 120 ° C. in step 88, the energization of the heater 24 is stopped in step 90. Step 89
After executing steps 90 and 90, the process proceeds to step 91 and the temperature detecting means 25
Detects the temperature of the container 20. Hereinafter, the same operation as that of the second embodiment of the invention is performed in steps 92, 93 and 94, and the process proceeds to step 99. If the lid 21 of the container 20 is closed in step 86, the process proceeds to step 95, where the temperature detecting means 25 detects the temperature of the container 20. The same operation as that of the second embodiment of the invention is performed in steps 96, 97 and 98, and the process proceeds to step 99 to wait for the input of the cancel key 32. If it is not determined in step 100 that the cancel key 32 has been pressed, the process returns to step 85. Step 10
Step 8 until it is judged that the cancel key 32 is pressed with 0
Steps 5 to 100 are repeated, and when the cancel key 32 is pressed in step 100, the process proceeds to step 101, the energization of all heaters is stopped, and the process returns to step 81.

As described above, according to the electric rice cooker of the third embodiment of the present invention, after the rice cooking process is moved to the heat retaining process, the lid 21 at the upper part of the container 20 is opened when the lid temperature is 120 ° C. or less. Heater 2
4 is continuously energized and the lid heater 24
When the lid 21 is opened, the temperature of the lid 21 can be raised to prevent dew condensation when the lid 21 is closed, and the lid 21 temperature can be prevented from abnormally rising. Lid of
If 21 is closed, the bottom heater 22, the body heater 23, and the lid heater 24 can be heated and controlled so that the temperature of the container 20 becomes the heat retention temperature.

EFFECTS OF THE INVENTION As is clear from the above embodiments, according to the first aspect of the present invention, even when the temperature of the container enters the heat retention step and exceeds the heat retention temperature, the dew inside the container is always controlled to control the heating of the lid heater. It is possible to always prevent the generation of heat and keep the heat without deteriorating the taste and shape of the rice due to the adhesion of dew.

Also, in the second invention, even if the lid on the upper part of the container is opened, the lid is continuously heated to maintain the temperature inside the lid at a high temperature, and even if the lid is closed again, dew is attached to the inside of the lid due to dew condensation. Can be prevented.

Further, according to a third aspect of the invention, when the lid is opened, the temperature inside the lid is maintained at a high temperature to prevent dew inside the lid, and the lid temperature is abnormally increased by heating the lid by the lid heater. In order not to do so, the heating of the lid heater is stopped when the specified temperature is reached, so that it is possible to prevent the user from being burned and the device from being damaged.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric rice cooker according to an embodiment of the present invention,
2 is a specific circuit diagram of the electric rice cooker, FIG. 3 is a flow chart showing the operation of the electric rice cooker, FIG. 4 is a block diagram of the electric rice cooker of another embodiment of the present invention, and FIG. A concrete circuit diagram of the electric rice cooker, FIG. 6 is a flow chart showing the operation of the electric rice cooker, FIG. 7 is a block diagram of the electric rice cooker of another embodiment of the present invention, and FIG. 8 is the electric rice cooker. FIG. 9 is a flowchart showing the operation of the electric rice cooker, FIG. 10 is a longitudinal sectional view of the conventional electric rice cooker, and FIG. 11 is a flowchart showing the operation of the electric rice cooker of the conventional example. 20 ... Container, 21 ... Lid, 22 ... Bottom heater, 23 ... Body heater, 24 ... Lid heater, 25 ... Temperature detection means, 26 ... Control means.

Claims (3)

[Claims] 1. A container provided with a lid on the top for containing rice and water,
A bottom heater that heats the bottom of the container, a body heater that heats the side of the container, a lid heater that heats the inside of the lid, a temperature detector that detects the temperature of the container, and the temperature detector. A control means for inputting a signal from the means, wherein the control means is provided with the bottom heater so that when the temperature detecting means falls below a specified heat retention temperature immediately after entering the heat retention step from the rice cooking step, the temperature becomes the heat retention temperature. The body heater and the lid heater are each energized at a constant energization rate, and when the temperature exceeds a prescribed heat retention temperature, the energization of the bottom heater and the body heater is stopped, and the energization rate of the lid heater is lowered. Controlled electric rice cooker. 2. Opening / closing detection means for detecting opening / closing of the lid of the container is provided, and the control means inputs a signal from the temperature detecting means and the opening / closing detection means, while the lid of the container is opened by the opening / closing detection means. The electric rice cooker according to claim 1, wherein the electric rice cooker is controlled so as to increase the energization rate of the lid heater. 3. A lid temperature detecting means for detecting the temperature inside the lid is provided, and the control means inputs signals of the lid temperature detecting means, the temperature detecting means and the open / close detecting means, and is defined by the lid temperature detecting means. The electric rice cooker according to claim 2, wherein the lid heater is controlled so as to stop energization when the lid temperature rises above the temperature.