JPH03212228A - electric rice cooker - Google Patents

Abstract

PURPOSE:To prevent dew condensation on the inner side of a lid by controlling bottom, barrel and lid heaters for supplying power thereto at a constant rate, when an output signal from a temperature detection means drops to or below the level of the predetermined thermal insulation temperature, and further controlling the aforesaid heaters for stopping power supply to the bottom and barrel heaters, and supplying power only to the lid heater, when the output signal exceeds the aforesaid temperature level. CONSTITUTION:A control means 27, upon receipt of an output signal from a temperature detection means 26, controls a lid heater 23, a barrel heater 24 and a lid heater 25 respectively for a constant rate of power supply thereto immediately at the start of a thermal insulation process after a cooking process, so as to maintain thermal insulation temperature when an output signal from the temperature detection means 26 drops to or below the predetermined thermal insulation temperature. Also, the control means 28 controls the bottom heater 23 and the barrel heater 24 for interrupting power supply thereto, while supplying power only to the lid heater 25, when the output signal exceeds the predetermined thermal insulation temperature. During a thermal insulation process, the control is so made that the lid heater 25 is supplied with power and the temperature of a lid 22 does not drop. Consequently, a dew drop is not formed on the lid 22 and cooked rice is not deteriorated in taste, shape or the like due to the fall of dew drops.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electric rice cooker having a heat retention function.

BACKGROUND OF THE INVENTION In recent years, electric rice cookers with a heat-retaining function are required not only to cook rice well, but also to have a heat-retaining function that is delicious and keeps the rice hot.

A conventional electric rice cooker of this type will be explained with reference to FIGS. 4 and 5.

As shown in FIG. 4, there is a container 2 with a lid 1 on the top to hold rice and water, and a bottom heater 3 that heats the bottom of the container 2.
, a body heater 4 that heats the side portion of the container 2, and a
A thermistor 6 detects the temperature of the container 2, and a signal from this thermistor 6 is input, and the temperature of the container 2 detected by the thermistor 6 reaches the specified warming temperature immediately after the rice cooking process enters the warming process. A device 3 comprising a control circuit board 6 that controls the bottom heater 3 and the body heater 4 to respectively energize at a constant energization rate or stop energization.

Next, the operation of this conventional electric rice cooker will be explained with reference to the flowchart shown in FIG.

In FIG. 6, a rice cooking process is performed in step 1o. In step 11, it is determined whether the rice cooking process has been completed, and if the rice cooking has not been completed, the process returns to step 1o.
Repeat steps 10 to 11 until the rice is cooked.

When the rice cooking is finished, proceed to step 12 and check the thermistor 5.
Enter the temperature of container 2 using . Next, in step 13, if the temperature has not reached the insulating temperature (71.5°C), in step 14, the body heater 4 is turned to 16/16, and the bottom heater 3 is turned to 1/16.
The current is applied at an energization rate of 16, and if the temperature exceeds the heat retention temperature, the energization of the trunk heater 4 and the bottom heater 3 is stopped in step 16. After executing steps 14 and 15, the process returns to step 12.

Steps 12 to 16 were repeated to control the temperature of the container 2 to the keeping temperature, thereby keeping the rice in the container 2 warm.

Problems to be Solved by the Invention In such conventional electric rice cookers, when the lid is opened and then closed again while the rice is being kept warm, the lid is cold, so dew forms on the inside of the lid, and the dew forms on the rice. There was a problem that the rice would fall onto the top and contain a lot of moisture, causing it to lose its shape and turn white.

The present invention solves the above problems by controlling the heating of the lid at the top of the container using a lid heater to prevent dew from forming on the inside of the lid, thereby reducing the taste of the rice.

The purpose is to retain heat without deteriorating its shape.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a container with a lid on the top for storing rice and water, a bottom heater that heats the bottom portion of the container, and a width portion of the container that heats the bottom portion of the container. A body heater that heats the
It includes a lid heater that heats the inside of the lid of the container, a temperature detection device that detects the temperature of the container, and a control device that inputs a signal from the temperature detection device, and the control device controls the process from the rice cooking process to the warming process. Immediately after entering, if the output of the temperature detection means is below the specified heat retention temperature, the bottom heater, the body heater, and the lid heater 5/\-7 are each operated at a constant energization rate so that the temperature is maintained. A means for solving the problem is to perform control such that when electricity is applied and the temperature exceeds a prescribed heat retention temperature, electricity is turned off to the bottom heater and the body heater, and only the lid heater is energized.

According to the above-described structure, the present invention controls the bottom heater and the body heater so that after the rice cooking process moves to the warming process, the bottom heater and the body heater are set at a prescribed warming temperature based on the output of the temperature detection means. In addition, the lid heater is continuously energized at a constant energization rate regardless of the output of the temperature detection means, without lowering the temperature inside the lid. It can prevent dew from adhering.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1, 2, and 3.

As shown in the figure, a container 21 has a lid 22 on the top and contains rice and water. The bottom part of this container 21 is heated by the bottom heater 23, and the side part is heated by the body heaters 2461, -7. The lid heater 26 heats the inside of the lid 22. The temperature detection means 26 detects the temperature of the container 21. The control means 27 inputs the signal from the temperature detection means 26, and immediately after entering the heat retention step from the rice cooking process, if the output of the temperature detection means 26 falls below the specified heat retention temperature, the bottom heater is activated so that the temperature is maintained. 23, body heater 24 and lid heater 2
6 are respectively energized at a constant energization rate, and when the predetermined insulating temperature is exceeded, the bottom heater 23 and the body heater 24 are de-energized, and only the lid heater 26 is energized.

Next, FIG. 2 is a specific circuit diagram, in which a start key 28 is used to start the rice cooking process, and a cancel key 29 is used to cancel the rice cooking process and the warming process.

Temperature detection means (hereinafter referred to as a thermistor) 26 is connected to the container 21
Detects the temperature of the A/D converter 30, inputs it to the A/D converter
The D converter 3o A/D converts the signal from the thermistor 26. The relay 31 is for energizing the bottom heater 23, and has a relay coil 31a and a relay contact 31b. Relays 77, -7 The drive section 32 drives the relay 31.

The relay 33 is only for energizing the body heater 24.
It has a relay coil 33a and a relay contact 33b.

The relay drive unit 34 drives the relay 33.

The relay 36 is for energizing the lid heater 26.
It has a relay coil 36a and a relay contact 35b.

The relay drive section 36 drives the relay 36.

The input section 37 receives signals from the start key 28, the cancel key 29, and the A/D converter 30. The output section 38 outputs relay opening/closing signals to each of the relay driving sections 32, 34, and 36. The control section 39 controls the output section 38 based on the signal input from the input section 37 . The microcomputer 40 includes an input section 37, an output section 38, and a control section 39.
It is composed of

FIG. 3 shows a flowchart showing the operation of the microcomputer 4o, and the operation will be explained with reference to this flowchart.

In FIG. 3, the start key 28 is inputted in step 6o, it is determined in step 51 whether or not the pressed key is the start key 28, and the steps 50 and 50 continue until the start key 28 is pressed.
Repeat steps 51 from . If the start key 28 is pressed in step 51, the process advances to step 52 to execute the rice cooking process. In step 63, it is determined whether the rice cooking process has finished, and if the rice cooking has not finished, the process returns to step 52.
Steps 52 and 53 are repeated until the rice cooking is completed.

When the rice cooking is completed, the process proceeds to step 64, where the temperature of the container 21 is detected by the temperature detection means 26.

If the temperature detected in step 65 is lower than the heat retention temperature of 71.5°C, the process proceeds to step 66, and the body heater 24 is
A6, bottom heater 23 1/16, lid heater 26 8/1
If the temperature exceeds the heat retention temperature in step 56, the power supply to the body heater 24 and the bottom heater 23 is stopped in step 57, and the lid heater 26 is turned on at an energization rate of 8/16. Turn on electricity. After executing steps 66 and 67, the process advances to step 58, where the cancel key 29 is input. If it is determined in step 59 that the cancel key 29 has not been pressed, the process returns to step 64. Take 9 in step 59
Step 54 until it is determined that the page erase key 29 has been pressed.
Step 59 is repeated from . When the cancel key 29 is pressed in step 69, the process proceeds to step 6Q, where the energization of all heaters is stopped and the process returns to step 5o.

As described above, according to the electric rice cooker of the embodiment of the present invention, after moving from the rice cooking process to the warming process, if the temperature falls below the warming temperature, the bottom heater 23, the body heater 24, and the lid heater 25 are heated and controlled. If the temperature exceeds the heat retention temperature, the power supply to the bottom heater 23 and the body heater 24 is stopped, and only the lid heater 26 is energized, so the temperature of the container 21 is controlled to the heat retention temperature to keep the rice delicious and warm. At the same time, when keeping the food warm, the lid heater 25 is energized and controlled so that the temperature of the lid 22 does not drop, so dew does not form on the lid 22 and drips onto the rice and affects the taste and shape of the rice. It will not deteriorate.

Effects of the Invention As is clear from the above embodiments, according to the present invention, even if the lid is opened to take out the rice in the container during the warming process, the lid heater provided on the lid does not Since the inside of the lid of the container is constantly heated and dew does not form on the lid, the rice can be kept warm without deteriorating the taste, shape, etc. of the rice due to the dew falling onto the rice.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an electric rice cooker according to an embodiment of the present invention.
Fig. 2 is a specific circuit diagram of the electric rice cooker, Fig. 3 is an operation flowchart of the microcomputer in the electric rice cooker, Fig. 4 is a vertical cross-sectional view of a conventional electric rice cooker, and Fig. 5 is a diagram of the conventional electric rice cooker. It is an operation flowchart of an electric rice cooker. 21...container, 22...lid, 23...
... Bottom heater, 24 ... Body heater, 25.
... Lid heater, 26 ... Temperature detection means,
27... Control means.

Claims (1)

[Claims] A container with a lid on the top and containing rice and water, a bottom heater that heats the bottom of the container, a body heater that heats the side surface of the container, and a lid heater that heats the inside of the lid of the container. , comprising a temperature detection means for detecting the temperature of the container, and a control means for inputting a signal from the temperature detection means, and the control means controls the output of the temperature detection means immediately after entering the warming step from the rice cooking step. If the temperature is below the specified heat retention temperature, the bottom heater, the body heater, and the lid heater are energized at a constant energization rate so that the temperature is maintained, and if the temperature exceeds the specified temperature, the bottom heater and the lid heater are energized. An electric rice cooker that is controlled so as to stop energizing the body heater and energize only the lid heater.