JPS5917218Y2 - electric rice cooker - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric rice cooker whose rice cooking capacity can be continuously selected.

Conventionally, a device for adjusting the calorific value according to the rice cooking capacity is known (see Japanese Utility Model Publication No. 10851/1983).

However, this method did not allow continuous selection of rice cooking capacity.

Moreover, by reducing the amount of heat generated at the beginning of rice cooking and increasing the amount of heat generated after the temperature exceeds a predetermined temperature, cooked rice, etc. cannot be made delicious.

The purpose of the present invention is to provide an electric rice cooker that allows the rice cooking capacity to be continuously selected, and also reduces the amount of heat generated in the initial stage of rice cooking, thereby achieving good rice cooking.

In the present invention, in order to enable continuous selection of rice-cooking containers, a plurality of rice-cooking heaters are installed, and the amount of heat generated is made variable by means of a switch.

Additionally, an NTC thermistor was connected in series to the heater in order to reduce the amount of heat generated during the initial stage of rice cooking.

This will be explained in detail below using figures.

FIG. 1 is a sectional view showing an example of an electric rice cooker to which the present invention is applied.

In the figure, a hot plate 2 is provided on the bottom of the inner container 1,
Three rice-cooking heaters 30, 3□, and 33 are embedded in the hot plate 2.

A heat-retaining heater 5 is provided on the upper part of the side wall 4, and the heat-retaining heater 5 is turned on and off by a heat sensing switch 6.

FIGS. 2 and 3 are diagrams for explaining the relationship between the heater calorific value and the rice cooking capacity according to the present invention.

Referring to FIG. 2, the above rice cooking heater 3□, 3°.

33 are provided in parallel with each other, and each heater 3□, 3□, 3
A rice cooking switch 7 is provided in series with the rice cooker 3.

The rice-cooking heaters 3□, 33 include the rice-cooking heaters 3□, 3.
Turn on only 3.

Changeover switches 8□, 83 are provided to turn off.

It has been confirmed through our experiments that the characteristic of the effective calorific value of the rice-cooking heater relative to the rice-cooking capacity is the shaded area shown in FIG. 3.

That is, referring to Fig. 3, the rice cooking container is 4 cups (0,7
2l), 310-390W is a good calorific value, and when the rice cooking capacity is 10 go (1,81), it is 540W.
~660W is a good heater heat generation amount.

And they have an intermediate cooking capacity of 4 cups (0.72 cups).
1) to 10 (1,81)].

For example, when the rice cooking capacity is 7 cups (1,261),
A good heater heat output is 30 to 520 W.

Expressing the above relationship mathematically, the amount of heat generated by the heater is Q(W),
Assuming that the rice cooking capacity is ■ (combined, 0.181), the relational expression for the upper limit straight line A becomes Q = 45 V + 210, and the relational expression for the lower limit straight line mouth becomes Q = 38 V + 157.

Therefore, the good range of Q is 38V+157≦Q≦45V+210 becomes.

Furthermore, the optimal relationship between Q and ■ is estimated to be at a position midway between the straight line A and the mouth, so the relational expression to the straight line is Q = 42 V + 183.

Using the above relational expression, 4 go (0,72l) to 10
An example of the heater calorific value that can be used in a rice cooking capacity range of 1.8 liters is given below.

When the rice cooking heater 31 is 400W, the rice cooking heater 32 is 100W, and the rice cooking heater 33 is 100W,
It is possible to adopt a heat generation amount of 400 to 600W, and as shown in Figure 3, it is approximately 4 go (0,721) to 10 go (1,
81) can be cooked well.

That is, in FIG. 2, when only the rice cooking switch 7 is turned on, the amount of heat generated is 400W, and when the rice cooking switch 7 and the changeover switch 8□ are turned on, the amount of heat generated is 500W.

Further, when all the switches 81, 82 and 83 are turned on, the amount of heat generated is 600W.

The amount of heat generated by the heater is adopted within the range shown in the following table.One embodiment of the present invention will be described below with reference to FIG. 4.

An NTC thermistor 9 is provided in series with each of the rice cooking heaters 3,', 32', and 33'.

The thermistor 9 has a large resistance when the temperature is low, and a small resistance when the temperature exceeds a predetermined temperature. By providing this thermistor 9, the characteristics of the rice cooking temperature with respect to the rice cooking time become as shown in FIG.

That is, while the rice cooking temperature is low, the resistance of the NTC thermistor 9 is large, so the amount of heat generated is small, and therefore the temperature rises slowly.

When the predetermined temperature determined by the NTC thermistor 9 is exceeded, the resistance decreases, the amount of heat generated increases rapidly, and the temperature increases rapidly.

According to the present invention, there are the following effects.

In other words, it is possible to set an appropriate heating temperature according to the continuous rice cooking capacity, and due to the action of the NTC thermistor, the rice starts with a relatively low calorific value at the beginning of cooking, and increases to a high calorific value when the temperature exceeds a predetermined temperature. This allows the rice grains to absorb sufficient water and activate the enzymes contained in the rice grains, resulting in better cooked rice.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of an electric rice cooker to which the present invention is applied, Fig. 2 is a circuit diagram for explaining the relationship between the calorific value and rice cooking capacity of the present invention, and Fig. 3 is a diagram showing the relationship between the calorific value and rice cooking capacity of the present invention. A characteristic diagram for explaining the relationship with rice cooking capacity, FIG. 4 is a circuit diagram of an embodiment of the present invention, and FIG. 5 is a diagram showing the characteristic of rice cooking temperature with respect to rice cooking time. 3, ', 3□', 33': Heater for rice cooking, 7: Switch for rice cooking, 82.83: Selector switch, 9: NTC thermistor.

Claims (1)

[Scope of utility model registration request] The rice cooking heater comprises a plurality of rice-cooking heaters, an NTC thermistor connected in series to each of the plurality of heaters, and a switch that simultaneously selectively causes one or more of the heaters to generate heat, An electric rice cooker in which the rice cooking capacity can be continuously selected by selecting the calorific value of each rice cooking heater within a range determined by the rice cooking capacity and heater calorific value characteristics.