JPH0433825Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rice cooker, and particularly to a rice cooker that can cook not only white rice but also brown rice.

(Prior Art) Recently, multi-functional electronic rice cookers have been put into practical use that are equipped with a built-in microcomputer and are capable of cooking not only delicious white rice but also brown rice and other types of rice. In addition, even in conventional electric rice cookers that use a temperature switch to switch between rice cooking operation and warming operation, there has been proposed one that is provided with a function to control the power supplied to the rice cooker in order to cook delicious rice. For example, in Utility Model Application Publication No. 55-11153,
A parallel circuit consisting of a temperature switch and a diode that senses the temperature of the pot is connected in series with the rice cooker, and at the initial stage of the rice cooking process, power is supplied to the rice cooker heater via the diode to heat the pot with low power and the pot is heated. When the temperature reaches a predetermined temperature, the rice cooker turns on the temperature switch to short-circuit the diode and supply maximum power to the rice cooking heater. A temperature switch is provided to detect the temperature of the water storage space formed between the outer pot and the inner pot, and when the water in the water storage space formed between the outer pot and the inner pot is almost extinguished, the temperature switch is activated and A rice cooker has been proposed in which electric power is supplied to a rice cooking heater using a rice cooker.

(Problem that the invention aims to solve) However, electronic rice cookers with a built-in microcomputer have a complicated structure and high cost. Since the pattern is constant, good results can be obtained when cooking white rice, but it has been difficult to obtain satisfactory results when cooking other types of rice. For example, if you start cooking immediately after polishing brown rice, there is a problem that only rice with a core can be cooked because the brown rice cannot absorb enough water.

Therefore, an object of the present invention is to provide an inexpensive rice cooker that can deliciously cook white rice and brown rice with a simple configuration without using a microcomputer.

(Means for solving the problem) As a means for solving the problem, the present invention, as shown in FIG. A rice cooker equipped with a temperature switch 7 that energizes the rice cooking heater 10 until the temperature of the inner pot reaches the rice cooking completion temperature,
A series circuit consisting of a thermostat 12, which is attached to the outer pot 2 housing the inner pot 3 and turns on at a predetermined temperature, and a changeover switch 13 connected in series between the rice cooking heater 10 and the normally closed contact of the temperature switch 7. and,
The present invention provides a rice cooker characterized in that a power control circuit 15 consisting of a diode D connected in parallel is inserted into the series circuit.

In a preferred embodiment, the rice cooking heater 10
is installed away from the outer pot 2, and the thermostat 1
2 is arranged at the bottom of the outer pot 2.

(Function) When the rice cooker according to the present invention cooks rice with the changeover switch 13 in the ON state, in the initial stage of the rice cooking operation, the water temperature is low and the thermostat 12 is OFF. 10
Electric power is supplied to the inner pot 3, and the inner pot 3 is heated with 50% of the maximum electric power. When the water temperature rises and the bottom of the outer pot, which is heated by heat conduction via the inner pot, reaches a predetermined temperature, the thermostat 12 is turned on, so power is supplied to the rice cooking heater 10 via the thermostat 12. , the inner pot is heated at maximum power until the rice is cooked. When the rice cooking is completed, the temperature switch 7 is switched to the normally open contact side, and the rice keeps warm. This power supply pattern is used when cooking white rice.

On the other hand, when cooking rice with the changeover switch 13 in the OFF state, power is supplied to the rice cooking heater 10 via the diode D from the initial stage of the rice cooking operation until the rice cooking is completed, and when the rice cooking is completed, the rice heating operation shifts to the warming operation. This power supply pattern is used when cooking brown rice.

Examples of the present invention will be described below.

(Example) In FIGS. 1 to 3 showing the rice cooker according to the present invention, 1 is an exterior body, 2 is an outer pot, 3 is an inner pot, 4 is a lid body hinged to the exterior body 1, and 5 is the lock release button when opening the lid body 4, 6 is the power cord, 7 is the temperature switch, 8 is the thermal reed switch, 9
13 is a heating plate, 13 is a changeover switch, 17 is a temperature fuse, 18 is a power switch, and 19 is a bottom body which is fixed to the outer pot 2 with a set screw 16. The heating plate 9 on which the inner pot 3 is placed is equipped with a rice cooking heater 10, and the heating plate itself is supported by a plurality of support pieces 20 to support the outer pot 2.
It is supported away from the The outer pot 2 has a heat-retaining heater 11 and a thermal reed switch 8 attached to its outer periphery.

As shown in FIG. 1, the rice cooking heater 10 is connected to a normally closed contact of a temperature switch 7 via a power control circuit 15, and the temperature is controlled via a series circuit consisting of a heat retention heater 11 and a thermal reed switch 8. It is connected to the normally open contact of switch 7. The power control circuit 15 includes a series circuit formed by connecting a thermostat 12 and a changeover switch 13 in series, which are turned on at a predetermined temperature, and a diode D connected in parallel to the series circuit. The temperature switch 7 has a known structure, for example, as shown in FIG.
, a micro switch 22, and an operating lever 23 that operates the micro switch 22 under the action of the magnetic temperature sensor 2.

If the thermostat 12 is placed so as to directly receive the heat from the rice cooking heater 10 or the heat retention heater 11 or to come into contact with the inner pot, there is a risk of malfunction during preheating cooking.
The thermostat 12 is attached to the lower part of the outer pot 2, preferably at the bottom, to prevent the preheating time from becoming short when rice is washed with hot water and started to be cooked.
By arranging a heating plate 9 to which a rice cooking heater 10 is attached apart from an outer pot 2, a preheating time corresponding to the amount of rice to be cooked is ensured, and delicious rice can be cooked.

When using the rice cooker having the above structure, for example, when cooking polished rice, the changeover switch 13
Turn it on, that is, cook rice in preheat cooking mode. The rice cooking operation is started by pressing the rice cooking switch 25. At this time, the operating lever 23
The temperature switch 7 is set by the action of , and the micro switch 22 is switched to the normally closed contact side. At the initial stage of this preheating cooking mode, the thermostat 12 is off and power is supplied to the rice cooking heater 10 via the diode D, so the rice starts with 50% of the rated power as shown in Figure 4A. be done. Therefore, the rice in the inner pot 3 is heated with low power, so-called low heat, and sufficient water absorption time is ensured.

When the temperature at the bottom of the outer pot 2, which increases due to heat conduction from the inner pot 3, reaches a predetermined temperature, for example, 40°C,
Since the thermostat 12 is turned on and the diode D is short-circuited, power is supplied to the rice cooker heater 10 via the thermostat 12, and the inner pot 3 is heated with 100% power, so-called high heat. When the water in the inner pot 3 runs out and the temperature at the bottom of the inner pot 3 reaches the operating temperature of the temperature switch 7, for example 135°C, rice cooking is completed and the temperature switch 7 switches to the normally open contact side to keep the rice warm. mode. In this heat retention mode, the thermal reed switch 8 acts to intermittently energize the heat retention heater 11 and the rice cooking heater 10, and the cooked rice is maintained at a predetermined temperature, for example, 70°C.

On the other hand, when cooking brown rice, the changeover switch 13 is turned off, that is, the rice is cooked in the brown rice cooking mode. In this case, since the changeover switch 13 is in the OFF state, even if the thermostat 12 is turned on midway through, the diode D will not be short-circuited. Electric power is supplied through diode D from this stage to the completion of rice cooking, and rice is cooked over low heat. Inner pot 3
When the temperature at the bottom of the rice cooker reaches the operating temperature of the temperature switch 7, rice cooking is completed, the temperature switch 7 switches to the normally open contact side, and shifts to the warming operation. From then on, the cooked rice is kept warm at a predetermined temperature in the same manner as in the preheat cooking mode.

Therefore, the rice cooker according to the present invention can operate the changeover switch 13 without using a microcomputer.
You can cook two types of rice, white rice and brown rice, with a simple switch.

In addition, since the thermostat 12 is placed at the bottom of the outer pot 2, even if hot water around 40°C is used to wash rice when cooking in preheating mode,
Since the heat is conducted to the thermostat 12 via the inner pot 3 and the outer pot 2, the thermostat 1
As a result, the thermostat 12 is turned on after the water temperature in the inner pot 3 reaches a higher temperature, for example, about 50°C, as a result of the time lag in the temperature detected by the thermostat 2 at 40°C. Therefore, even if hot water is used to wash the rice, sufficient time is secured for the rice to absorb the water, and delicious rice without a core can be cooked. Similarly, the time it takes for the water temperature to rise to the specified temperature changes depending on the amount of rice cooked.
As a result of changing the time until the thermostat 12 is turned on, a water absorption time corresponding to the amount of rice to be cooked is ensured.

Furthermore, since the outer periphery of the outer pot 2 is surrounded by a heat insulating material 24, the time it takes for the thermostat 12 to detect a predetermined temperature is not greatly affected by the outside temperature, and if the amount of rice cooked is constant, it can be cooked in all seasons. The rice is cooked in an approximately constant amount of time throughout the process.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways. For example, in the above embodiment, the power switch 18 is inserted to turn off the heat retention to save power, but as long as the power switch 18 is omitted and the rice cooker is plugged into an outlet,
A heat-retaining operation may also be performed. Also,
During the heat retention operation, the heat retention heater 11 is connected in series with the rice cooking heater 10, but only the heat retention heater 11 may be energized.

(Effects of the invention) As is clear from the above explanation, according to the invention, it is possible to manufacture an inexpensive rice cooker with a simple configuration that can cook rice in two ways: preheating and brown rice, and also with a thermostat. By attaching the rice cooker to the bottom of the outer pot, it is possible to prevent the rice cooker from malfunctioning, and at the same time, it has the excellent effect of facilitating assembly during manufacturing.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram of a rice cooker showing an embodiment of the present invention, Fig. 2 is a schematic sectional view showing the structure of the rice cooker shown in Fig. 1, and Fig. 3 is a bottom body of the rice cooker shown in Fig. 2. FIG. 4 is a characteristic diagram showing changes in the power supplied to the rice cooker of FIG. 1. 1...Exterior body, 2...Outer pot, 3...Inner pot, 4...
... Lid body, 7 ... Temperature switch, 8 ... Thermal reed switch, 9 ... Heating plate, 10 ... Rice cooking heater, 11 ... Heat retention heater, 15 ... Power control circuit, D ... Diode.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A rice-cooking heater 10 that heats the inner pot 3, and a temperature switch that detects the temperature of the inner pot 3 and energizes the rice-cooking heater 10 until the temperature of the inner pot reaches the rice-cooking completion temperature. 7, a thermostat 12 and a changeover switch 13 are installed between the rice cooking heater 10 and the normally closed contact of the temperature switch 7, and are attached to the outer pot 2 that accommodates the inner pot 3 and are turned on at a predetermined temperature. A series circuit formed by connecting in series,
A rice cooker characterized in that a power control circuit 15 comprising a diode D connected in parallel is inserted into the series circuit. (2) The rice cooker according to claim 1, wherein the thermostat 12 is disposed at the bottom of the outer pot 3.