JPH10290749A - Electric pressure cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooking performance without requiring any thermistor, control circuit, thyristor for time switch and thyristor for relay by reducing heating quantity at a temperature lower than the temperature of pressure in order to prevent boiling-over outside a pressure vessel. SOLUTION: A pressure vessel 7 is freely attachably and detachably housed in a main body 1 of instrument and placed on a completed electric heating body 4. Concerning the completed electric heating body 4, an inner electric heating body 5 is casted into aluminium inside and an outer electric heating body 6 is casted into aluminium outside. The temperature of pressure in the pressure vessel 7 is about 120 deg.C, a switching thermostad 16 is integrated near the center of completed electric heating body 4, and a thermosensitive part is press-contacted on the base of pressure vessel 7. When the outer electric heating body 6 is electrified and the temperature in the pressure vessel 7 rises to 110-117 deg.C, the switching thermostad 16 is operated, and the inner and outer electric heating bodies 5 and 6 are serially electrified. Thus, by changing power from 80 W to 200 W, for example, steam can be generated so as not to boil over when a pressure cooking temperature reaches 120 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric pressure cooker mainly used at home.

[0002]

2. Description of the Related Art Generally, an electric pressure cooker is required to be cooked so as not to spill over during pressure cooking.

Conventionally, the structure of this type of electric pressure cooker is shown in FIG.
The configuration is as shown in FIG. Hereinafter, the configuration will be described with reference to FIGS.

[0004] In FIG. 3, a pressure vessel 7 is removably housed in the instrument body 1 and is mounted on an electric heating element 31. The lid 9 covers the upper opening of the pressure vessel 7 so that it can be opened and closed. A nozzle 11 is attached to the lid 9, and a weight 12 is placed on the nozzle 11. A packing 15 is removably interposed between the pressure vessel 7 and the outer periphery of the lid 9. The electric heating element 31 is incorporated in the protective frame 2, the protective frame 2 is fixed to the appliance body 1, and the control circuit 33 is provided on the bottom of the appliance body 1, and the time switch 17 and the neon lamp 20 are incorporated on the side surface. 19 were arranged and configured.

[0005] Here, the food is put into the pressure vessel 7, the lid 9, the packing 15, and the weight 12 are set, the electric heater 31 is placed, and the time switch 17 is turned on according to the time according to the food. Then, energization of the electric heating element 31 is started. When the pressure in the pressure vessel 7 increases, the pressure indicating pin 14
To indicate that the pressure has increased. The thermistor 32 detects the bottom surface temperature of the pressure vessel 7 and sets the pressure cooking temperature to 3 to 7.
The thyristor 34 for a time switch is turned on just before the temperature is 0 ° C., and the time switch 17 starts to operate.

When the bottom surface temperature of the pressure vessel 7 reaches the pressure cooking temperature, the thermistor 32 detects, the relay thyristor 36 is turned off, the contact of the relay 35 is turned off, and the heat generation of the electric heating element 31 is stopped. . When the temperature drops, thermistor 3
2 is detected, the relay thyristor 36 is turned on, and the relay
The contact No. 5 is turned on, and the electric heating element 31 generates heat. This operation is repeated, and when the time switch 17 is turned off, the heating of the electric heating element is stopped, the pressure in the pressure vessel 7 is reduced, and when the pressure indicating pin 14 is lowered, the lid 9 can be opened and the cooking is completed. . The weight is set as the function of a safety device, and the structure is such that steam does not leak from this point.

[0007]

However, in the above-described structure, since the pressure temperature is controlled, the boiling in the pressure vessel 7, that is, the bubbling phenomenon does not occur, so that the seasoning stains on the food. There was a problem that the temperature distribution in the pressure vessel 7 was not uniform due to poor convection or insufficient boiling convection, resulting in uneven cooking. Further, since the temperature is controlled by the thermistor 32, the control circuit 33, the thyristor 34 for the time switch, the relay 35, and the thyristor 36 for the relay, a large number of components are required and the cost is high.

An object of the present invention is to improve the cooking performance without the need for a thermistor, a control circuit, a thyristor for a time switch, a relay, and a thyristor for a relay.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a pressure vessel, a heating means for heating the pressure vessel, and a pressure regulating means for regulating the inside of the pressure vessel to a predetermined pressure temperature. Wherein the heating means reduces the amount of heating at a temperature lower than the pressure temperature by a predetermined temperature in order to prevent spilling out of the pressure vessel.

[0010]

The invention according to claims 1 to 5 comprises a pressure vessel, heating means for heating the pressure vessel, and pressure adjusting means for adjusting the inside of the pressure vessel to a predetermined pressure temperature, The heating means reduces the amount of heating at a temperature lower than the pressure temperature by a predetermined temperature to prevent spilling out of the pressure vessel. It is possible to improve soaking and reduce uneven cooking.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of an electric pressure cooker according to the present invention. FIG. 2 shows the internal electric heating element 5 and the switching thermostat 1
6 is a circuit diagram in which time switch coils 17a are connected in parallel.

Hereinafter, description will be made in accordance with the connection in the circuit diagram of FIG. As shown in FIG. 1, a pressure vessel 7 is detachably housed in the instrument main body 1 and placed on the completed electric heating element 4. The completed electric heating element 4 is formed by casting an inner electric heating element 5 on the inside and an outer electric heating element 6 on the outside with aluminum. The completed electric heating element 4 is incorporated in the protection frame 2, and the protection frame 2 is fixed to the instrument body 1. The lid 9 covers the upper opening of the pressure vessel 7 so that it can be opened and closed. Nozzle 1 on lid 9
1 is mounted, a weight 12 is placed on the nozzle 11, and the operating pressure of the weight 12 is usually 9.80665 × 1
It is set to 04 Pa. 9.80665 × 10 4 P
The pressure temperature of the water in the pressure vessel 7 at the time a is about 120 ° C. The operating pressure of the weight 12 is determined by the hole area of the nozzle 11 and the weight of the weight 12.

The packing 1 is provided between the outer periphery of the pressure vessel 7 and the lid 9.
5 is detachably interposed, maintains the tightness of the pressure vessel 7 and the lid 9, and increases the pressure. The switching thermostat 16 is incorporated near the center of the completed electric heating element 4, and this heat-sensitive portion protrudes from a hole opened near the center of the completed electric heating element 4 and is pressed against the bottom surface of the pressure vessel 7 by a spring. I have. The time switch 17 is incorporated in the display board 19 together with the neon lamp 20. Time switch 17
Is the time switch coil 17a and the time switch contact 1
7b. Reference numeral 18 denotes a time switch knob used for setting the cooking time of the time switch.

Reference numeral 3 denotes an instrument body handle, which is attached to the upper side surface of the instrument body 1, and is used when carrying the electric pressure cooker. Reference numeral 8 denotes a pressure vessel handle, which is attached to the upper side surface of the pressure vessel 7, and is used for attaching / detaching the pressure vessel 7 to / from the instrument body 1 and carrying the same. Reference numeral 10 denotes a lid handle, which is attached to the upper part of the lid 9 and is used for opening and closing the lid 9 and for carrying.

Numeral 13 denotes a safety device which is mounted on the top of the lid 9 so that when the switching thermostat 16 fails, the eutectic alloy melts and a hole is opened to prevent an abnormal rise in pressure in the pressure vessel 7. 14 is a pressure indicating pin attached to the upper part of the lid 9,
When the pressure in the pressure vessel 7 increases, it indicates that the pressure rises and the pressure is applied. Reference numeral 22 denotes a security thermostat mounted on the bottom surface of the completed electric heating element 4 to prevent the temperature of the completed electric heating element 4 from rising abnormally. Reference numeral 23 denotes a temperature fuse which is attached to the bottom surface of the completed electric heating element 4 and operates when the security thermostat 22 breaks down, and stops supplying electricity to the completed electric heating element 4. Reference numeral 21 denotes a stable resistor which is connected in series with the neon lamp 20.

The operation of the above configuration will be described.
The food is put in the pressure vessel 7, the lid 9, the packing 15, and the weight 12 are set and placed on the completed electric heating element 4.
By connecting the power supply and setting the time switch 17 to the cooking time according to the food, the time switch contact 17b
Is turned on to energize the external electric heating element 6 and the neon lamp 20, the temperature inside the pressure vessel 7 starts to rise, and the neon lamp 20 is also turned on to indicate the energized state. In this state, the contact of the security thermostat 22 and the contact of the switching thermostat 16 are ON. In addition, no voltage is applied to the time switch coil 17a.

When the pressure in the pressure vessel 7 rises, the pressure indicating pin 14 rises to indicate that the pressure in the pressure vessel 7 has risen. The operating pressure of the weight 12 is 9.80665
When the pressure is set to 10 4 Pa, when the temperature of the pressure vessel 7 reaches 110 to 117 ° C., the temperature is switched and the thermostat 16 senses and operates to turn off the contacts, and the internal electric heating element 5 and the external electric The heating elements 6 are energized in series. The voltage is also applied to the time switch coil 17a, and the time switch coil 17a is turned on, and the time switch 17 starts operating. When the capacity of the pressure vessel 7 is 3.2 L type, the power at startup is 800 W for the power of the external electric heating element 6 and the internal electric heating element 5 is connected in series with the external electric heating element 6. If the resistance of the internal electric heating element 5 is set so as to be 200 W at
When the pressure cooking temperature reached 120 ° C., steam was emitted from the weight 12 to such an extent that it did not spill over.

[0019] The limit of the spillover differs depending on the cooking material.
The results of a 3.2L type test of the degree of spillover in the case of cooking are as follows. If 1 cup of rice is used for 5 minutes, 350W will not wipe over. At 400 W, a slight spillover occurred. 350W for 2 cups of cooked white rice
No spill over. In the case of 2 cups of boiled beans, the spillover occurred at 350 W. No blow-off at 300W. Curry
In the case of 3 cups of lug 100g water, there is no spill at 300W. However, one cup is 200 mL.

In addition, in the case of 5 cups of cooked white rice, uneven cooking is likely to occur. As a result of comparison with a conventional electric pressure cooker that does not leak steam, the rice in the conventional electric pressure cooker is formed by hollow rice in the center. While it was harder than other parts,
The result of cooking rice with the configuration of the present invention was that there was no unevenness in the center and the rice was even and delicious. Specifically, in a conventional electric pressure cooker, for example, when about 8 go rice is put in a pressure vessel having a diameter of 22 cm, the peripheral height is about 10 c.
m, the center portion was indented to about 8 cm. However, as a result of having the internal electric heating element 5 and the external electric heating element 6 connected in series and emitting steam from the weight 12 at 100 W, only a slight depression was found at the center.

The heating power for maintaining the conventional pressure cooking temperature at 120 ° C. is about 45 W for the 3.2 L type. From the above example, the minimum heating power required to generate steam is about three times the power that does not cause steam leakage in consideration of uneven cooking of rice. The upper limit is about seven times the electric power that does not cause steam leakage when the difference between the surface height of the food in the pressure vessel 7 and the surface height of the lid 9 is about 6 cm, taking into account that spillage does not occur. In an actual design, it is necessary to set a median value in consideration of voltage fluctuation, room temperature fluctuation, and the like.

As described above, boiling occurs in the pressure vessel 7 and convection becomes active. As a result, the seasoning can be surely permeated into the food, the temperature distribution becomes uniform, and the cooking performance can be improved. Things.

At the preset cooking time, the time switch contact 17b is turned off, the heating of the internal electric heating element 5 and the external electric heating element 6 is stopped, the neon lamp 20 is turned off, and the power supply to the time switch 17a is terminated.

When the pressure in the pressure vessel 7 decreases, the pressure indicating pin 14 lowers, the lid 9 can be opened, and the cooking is completed.

Even if the connections of the inner electric heating element 5 and the outer electric heating element 6 in the circuit diagram are exchanged, the cooking performance can be sufficiently exhibited.

When the power supply voltage is higher than the rated voltage of the time switch 17, it can be handled by connecting a voltage-corresponding resistor in series with the time switch coil 17a.

As described above, an electric pressure cooker having a small number of parts, a simple circuit configuration, and a low cost can be provided.

Needless to say, the heating power can be adjusted by using the electronic control circuit. For example, a thyristor or the like can be used as the switching means, and the amount of heating power can be controlled by phase control, inverter control, or waveform cutting.

[0029]

As described above, the pressure vessel, the heating means for heating the pressure vessel, and the pressure adjusting means for adjusting the inside of the pressure vessel to a predetermined pressure temperature are provided. By reducing the heating amount at a temperature lower than the pressure temperature by a predetermined temperature in order to prevent spilling out of the container, boiling occurs in the pressure container, and a slight bubbling phenomenon can be generated, and as a result, In addition, the seasoning can be surely permeated into the food, the convection in the pressure vessel becomes active, the temperature distribution in the pressure vessel becomes uniform, and the cooking performance can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an electric pressure cooker showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of the electric pressure cooker.

FIG. 3 is a sectional view of a main part of an electric pressure cooker showing a conventional example.

FIG. 4 is a circuit diagram of the electric pressure cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument main body 2 Protective frame 3 Instrument main body handle 4 Complete electric heating element 5 Inner electric heating element 6 Outer electric heating element 7 Pressure vessel 8 Pressure vessel handle 9 Lid 10 Lid handle 11 Nozzle 12 Weight 13 Safety device 14 Pressure display pin 15 Packing Reference Signs List 16 switching thermostat 17 time switch 17a time switch coil 17b time switch setting point 18 knob for time switch 19 display board 20 neon lamp 21 stable resistor 22 security thermostat 23 temperature fuse 31 electric heating element 32 thermistor 33 Control circuit 34 Thyristor for time switch 35 Relay 36 Thyristor for relay

Claims (5)

[Claims] 1. A pressure vessel, heating means for heating the pressure vessel, and pressure adjusting means for adjusting the inside of the pressure vessel to a predetermined pressure temperature, wherein the heating means spills out of the pressure vessel. An electric pressure cooker in which the amount of heating is reduced at a temperature lower than the pressure temperature by a predetermined temperature so as to prevent the occurrence of heat. 2. The heating means is formed by connecting an internal electric heating element and an external electric heating element in series, and short-circuits one of the electric heating elements before the heating amount is reduced.
An electric pressure cooker as described. 3. The electric pressure according to claim 1, further comprising switching means for adjusting an amount of electric power supplied to the heating means, wherein the switching means controls an energization ratio according to the amount of electric power supplied to the heating means. pot. 4. A time switch for stopping a power supply to the heating means after measuring a predetermined boiling maintenance time, wherein the time switch starts measuring simultaneously with the start of reduction of the heating amount. Electric pressure cooker. 5. The temperature at which the amount of heating is started to be reduced is set to a value which is three times lower than the pressure
The electric pressure cooker according to claim 1, wherein the temperature is lower by 10 to 10C.