JP2852235B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rice cooker for cooking rice by heating a pot containing rice and water.

[0002]

2. Description of the Related Art Japanese Utility Model Application Laid-Open No. 61-56925 discloses that a lid heater and a heat-sensitive element are provided in a lid body, and a heating value of a rice cooker is limited by a signal of the heat-sensitive element. A rice cooker that starts and shifts to warming is disclosed. However, in this rice cooker, if the heating of the lid heater is too strong, problems such as deformation and discoloration of the lid occur.

Further, in this rice cooker, a separate inner lid is arranged on the lower surface side of the lid, so that heat radiated from the lid heater into the pot is blocked by the inner lid, and the heating efficiency is reduced. Will drop.

Therefore, in recent years, Japanese Utility Model Laid-Open No. 2-78 has been proposed.
As seen in No. 122, without using the inner lid, the lower surface member of the lid body is directly closed to the opening of the pan and closed, and the upper portion of the upper portion of the pan is formed based on the lid heater arranged on the back side of this lower surface member. There has been proposed a rice cooker that emits radiant heat directly to improve heating efficiency.

[0005] In this case, the broth (oneba) generated during cooking rice
Is in contact with and adheres to the lower surface member of the lid, and therefore, the surface of the lower surface member is coated with a resin such as a non-adhesive fluororesin so that the lower surface member can be easily cleaned.

[0006]

However, in the rice cooker disclosed in Japanese Utility Model Laid-Open No. 2-78122,
The lower member is simply heated by the lid heater, so that the lower member is heated more than necessary, and the lower member is heated .
When a resin coat is applied to the surface, the resin coat
May deteriorate, and the lid may be deformed or discolored.

The present invention has been made in view of such a point, and an object of the present invention is to maintain a proper temperature of a heat radiating plate, which is a lower surface member of a lid , by applying a resin coating on the surface thereof.
An object of the present invention is to provide a rice cooker capable of preventing deterioration of the rice cooker.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a lid for covering an opening of a pot, and a lower surface of the lid which directly faces the pot and has a lower surface. Is resin
And coating is applied radiating plate, provided on the back side of the heat radiating plate, cover the heating means for heating the heat radiating plate, and a heat-sensitive means for detecting the temperature of the radiator plate, sensing the temperature of the heat-sensitive means the
And a control means for stopping the energization of the lid heating means when the temperature reaches a predetermined temperature near the endurance temperature of the resin coat .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 shown in FIG. 1 is a cooking pot. An inner frame, an outer frame 3 and a frame 4 constitute a body, and the pot 1 is provided in the inner frame 2 so as to be detachable.

At the bottom center of the inner frame 2 is provided a heat sensing device 5, and a rice cooking heater 6 is disposed on the outer periphery of the heat sensing device 5 as a pot heating means. A heat retaining heater 7 is attached to the upper portion of the outer side surface of the inner frame 2.

A control unit 8 accommodating a control circuit to be described later is mounted on the bottom of the outer frame 3. 9 is pot 1
Is a lid that covers the opening of FIG. Inside the lid 9, a radiator plate 10 which constitutes the lower surface of the lid 9 and is directly opposed to the opening of the pan 1 is attached. The surface of the radiator plate 10 facing the pan 1 is coated with a resin, For example, a fluorine resin coat is applied. The durability temperature of this fluororesin coat is 250 ° C. or less.

A lid heater 11 is provided on the back surface of the heat radiating plate 10 as lid heating means, and a heat shield plate 12 covers the lid heater 11 so that heat from the lid heater 11 does not reach the lid 9. ing.

A pot bottom sensor 13 is provided inside the heat-sensitive device 5, and a pot sensor 14 is provided at a portion protruding downward from the center of the lid 9, and the heat radiation plate 10 and the heat shield are provided. In the vicinity of the lid heater 11 surrounded by the plate 12, a heat radiating plate sensor 15 is provided as heat sensing means. Each of these sensors 13, 14, 15 is a sensor for detecting temperature.

FIG. 2 is a block diagram showing a circuit configuration.
Is a microcomputer constituting the control unit body.
An analog output of the pan bottom sensor 13 that has detected the pan bottom temperature Td is converted into a digital signal by a first A / D converter 22 and supplied to the microcomputer 21.

The analog output of the radiator plate sensor 15 that has detected the radiator plate temperature Tu is converted into a digital signal by a second A / D converter 23 and supplied to the microcomputer 21.

The analog output of the in-pan sensor 14 detecting the pan upper temperature Ti is converted into a digital signal by a third A / D converter 24 and supplied to the microcomputer 21.

A clock circuit 25 for measuring the current time and the time of each cooking step is connected to the microcomputer 21. The operation unit 26 is connected to the microcomputer 21 and inputs various initial settings and manual operations.

The microcomputer 21 controls a display unit 28 via a display control circuit 27. The microcomputer 21 is connected via a heater control circuit 29 to
The heater switch unit 30 that directly controls the energization of the rice cooking heater 6, the heat retaining heater 7, and the lid heater 11 is controlled.

As shown in FIG. 3, the heater switch section 30 has a first closed circuit, a commercial power supply 31, the rice cooker 6 and a switch 32 (hereinafter referred to as SW32).
Are connected in series.

As the second closed circuit, the commercial power source 31, the rice cooking heater 6, the heat retaining heater 7, and the switch 33
(Hereinafter, referred to as SW33) are connected in series.
As the third closed circuit, the commercial power supply 31 and the lid heater 1
1 and a switch 34 (hereinafter referred to as SW34) are connected in series.

FIG. 4 is a flowchart showing rice cooking control by the microcomputer 21. When the microcomputer 21 enters this control, the SW 32 is turned on, and power is supplied to the rice cooking heater 6.

It is determined whether or not the detected temperature Tu of the radiator plate sensor 15 is higher than 115 ° C.
If it is above, it is determined that the rice is in the empty cooking state and the SW32 is turned off.
F. Perform empty cooking.

If the detected temperature Tu is lower than 115 ° C., it is next determined whether or not the rate of increase of the detected temperature Tu per 3 minutes is 1 ° C. or less. Increase rate of detected temperature Tu per 3 minutes is 1 ° C
Is exceeded, the process returns to the process of turning on the SW 32 again. If the detected temperature Tu is less than 115 ° C. and the rate of increase per 3 minutes is 1 ° C. or less, the SW
34 is turned on to supply power to the lid heater 11.

Next, the detection temperature Td of the pan bottom sensor 13
It is determined whether or not the detected temperature Td is equal to or higher than 120 ° C.
If the temperature is lower than 0 ° C., it is determined whether the detected temperature Tu of the heat sink sensor 15 is 200 ° C. or higher.

If the detected temperature Tu of the heat sink sensor 15 is 200 ° C. or more, the SW 34 is turned off, and if the detected temperature Tu is less than 200 ° C., the SW 34 is turned on. The process returns to the process of determining whether the detection temperature Td of the pan bottom sensor 13 is 120 ° C. or more again. When the detected temperature Td of the pan bottom sensor 13 becomes 120 ° C. or higher, the SW 32 is turned off to stop supplying power to the rice cooking heater 6.

Next, SW32 is set to O by the clock circuit 25.
The time after the FF is measured, and it is determined whether or not the measured time has elapsed 15 minutes. If 15 minutes have not passed,
It is determined whether or not the detected temperature Tu of the heat sink sensor 15 is 200 ° C. or higher.

When the detected temperature Tu of the heat sink sensor 15 is 20
If the temperature is 0 ° C. or more, the switch SW34 is turned off, and the detection temperature Tu
Is lower than 200 ° C., the switch SW34 is turned on. In any case, the clock circuit 2 is turned on again.
The process returns to the process of determining whether or not the measurement time measured by step 5 has elapsed 15 minutes.

When the time measured by the clock circuit 25 has elapsed for 15 minutes, the flow shifts to the heat retention control. FIG. 5 is a flowchart showing the heat retention control by the microcomputer 21. Upon entering the heat retention control, it is determined whether or not the detected temperature Td of the pan bottom sensor 13 is lower than 71 ° C.
If the detected temperature Td is 71 ° C. or higher, the switch 33 is turned off.

In any case, the sensor 1 in the pot
4 is the detected temperature Td of the pan bottom sensor 13
It is determined whether it is smaller than. If the detected temperature Ti is lower than the detected temperature Td, the SW 34 is turned on,
The process returns to the process of determining whether the detected temperature Td is lower than 71 ° C. again.

If the detected temperature Ti is equal to or higher than the detected temperature Td, it is determined whether or not a temperature obtained by adding 0.5 ° C. to the detected temperature Ti is lower than the detected temperature Tu of the radiator plate sensor 15. If the temperature obtained by adding 0.5 ° C. to the detected temperature Ti is equal to or higher than the detected temperature Tu, the SW 34 is turned on. If the temperature obtained by adding 0.5 ° C. to the detected temperature Ti is smaller than the detected temperature Tu, The SW 34 is turned off, and in any case, the process returns to the process of determining whether or not the detected temperature Td of the pan bottom sensor 13 is lower than 71 ° C.

In such a configuration, when cooking of rice cooking is started, first, heating by rice cooking heater 6 is started. At this time, if the pot 1 is in an empty cooking state such as when water is not put in with rice together with rice, when the temperature Tu detected by the heat sink sensor 15 reaches 115 ° C., The power supply is stopped.

In a normal case, since the water boils and reaches an equilibrium temperature around 100 ° C., the rate of rise of the temperature Tu detected by the heat sink sensor 15 per 3 minutes is 1 ° C.
At this time, heating of the radiator plate 10 by the lid heater 11 is started.

Temperature T detected by pan bottom sensor 13
Until d reaches 120 ° C., the temperature Tu detected by the heat sink sensor 15 is maintained at 200 ° C.
The energization control of the lid heater 11 is performed.

Temperature T detected by pan bottom sensor 13
When d reaches 120 ° C., the power to the rice cooker 6 is stopped. Until 15 minutes have elapsed from that time, the energization control of the lid heater 11 is performed so that the temperature Tu detected by the heat sink sensor 15 is maintained at 200 ° C.

After the elapse of 15 minutes, the heat-retaining heater 7 is energized so that the temperature Td detected by the pan bottom sensor 13 is maintained at 71 ° C. as the heat-retaining control. Also,
In order that the temperature Ti detected by the in-pan sensor 14 is not lower than the temperature Td detected by the pan bottom sensor 13, the temperature Ti detected by the in-pan sensor 14 is further detected by the radiator plate sensor 15. The energization of the lid heater 11 is controlled so that the temperature Tu is kept higher than 0.5 ° C.

As described above, the radiator plate 10 provided inside the lid 9 is provided on the back surface by the radiator plate sensor 15 during the rice cooking in which the water put together with the rice in the pot 1 boils. Since the lid heater 11 is controlled to be energized and heated to 200 ° C., condensation of water vapor on the lower surface of the radiator plate 10 is prevented.

During the heat insulation, the sensor 1 in the pot is used.
Since the temperature of the heat radiating plate 10 detected by the heat radiating plate sensor 15 is controlled to be 0.5 ° C. higher than the temperature of the upper portion of the pan 1 detected by 4, water droplets adhere to the lower surface of the heat radiating plate 10 even during the heat retention. Is prevented.

For example, even if the lid 9 is opened and closed during the heat insulation and the temperature of the upper part of the pan suddenly drops, the lid is immediately returned to a desired heat insulation state by heating by the lid heater 11 and the heat radiation plate 10 of the lid 9 is heated. There is no danger of water drops.

Further, since the heat radiating plate 10 is used, the heating capacity is smaller than that of the conventional method of heating the inner lid, so that a desired temperature can be obtained by low-power heating. Heat sink 1
Since the surface of No. 0 is coated with a fluororesin, it is difficult to be stained and is easy to remove. The durability temperature of the fluororesin coat is 250 ° C. or less, but the temperature of the heat sink 10 is
The temperature is controlled to be equal to or lower than the durability temperature of the resin coat, so that the resin coat does not dissolve and peel off.

By providing the radiator plate sensor 15, when the rice cooker is empty, such as when water is not put into the pot 1 together with rice or when the pot itself is not set, after the rice cooker is started. The abnormal temperature rise in the pot 1 or the inner frame 2 is detected, and the supply of electric power to the rice cooker 6 is stopped, so that empty cooking can be prevented and the cover 9 can be prevented from being damaged by high heat.

Therefore, there is an effect that the conventional pot switch can be removed. By providing the heat sink sensor 15 in this manner, a sequence that is more versatile than in the related art can be performed.

[0042]

As described above, according to the present invention,
A heat radiating plate constituting the lower surface of the lid is provided with a lid heating means for heating the heat radiating plate and a heat sensitive means for detecting a temperature of the heat radiating plate, and a temperature sensed by the heat sensitive means is applied to a surface of the heat radiating plate. When the temperature reaches a predetermined temperature near the endurance temperature of the resin coat, the energization of the lid heating means is stopped, so that the temperature of the lid is prevented from rising more than necessary and the surface of the radiator plate is cooled .
Deterioration of the resin coat can be reliably prevented. In addition, the inner lid is not provided on the lower surface side of the lid, and the heat-sensitive means is provided on the back side of the radiator plate directly facing the pan, so that heat radiation into the pan is not hindered, and the state in the pan Temperature of the heat sink can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a rice cooker according to one embodiment of the present invention.

FIG. 2 is a circuit diagram showing a circuit configuration of the rice cooker.

FIG. 3 is a circuit diagram of a heater switch unit of the rice cooker.

FIG. 4 is a flowchart of rice cooking control performed by a microcomputer of the rice cooker.

FIG. 5 is a flowchart of heat retention control performed by a microcomputer of the rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pot 6 ... Rice cooking heater 7 ... Heat keeping heater 9 ... Lid 10 ... Heat radiating plate 11 ... Lid heater 13 ... Pot bottom sensor 14 ... Pot sensor 15 ... Heat radiating plate sensor 21 ... Microcomputer 30 ... Heater switch part

Claims (1)

(57) [Claims] 1. A lid for covering an opening of a pot, and a lower surface of the lid, which directly faces the pot and has a resin coat on the surface.
And decorated with radiating plate, provided on the back side of the heat radiating plate, cover the heating means for heating the heat radiating plate, and a heat-sensitive means for detecting the temperature of the radiator plate, sensing the temperature of the resin Kor heat-sensitive means
And a control means for stopping the energization of the lid heating means when the temperature reaches a predetermined temperature near the endurance temperature of the rice cooker.