JPH0319770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a control device for a pressure cooker used in general households. In this type of pressure cooker, there are two methods for controlling the pressure inside the pressure vessel: a method using a pressure regulating valve and a method using temperature control.

By the way, the former method using a pressure regulating valve is complicated to operate, as it is necessary to manually adjust the heating amount once the pressure regulating valve starts operating, and it is also necessary to start a timer to set the cooking time. This method has the advantage that high-quality cooking can be achieved because the steam inside the pressure vessel flows smoothly. On the other hand, the latter temperature control method uses a control circuit and a timer to automatically control the amount of heating and set the cooking time, making it easy to operate. It has the disadvantage that it has poor fluidity and cannot produce high-quality cooking.

The present invention aims to provide a pressure cooker that takes advantage of these two methods and eliminates their drawbacks, that is, a pressure cooker equipped with a control device that is easy to operate and can provide high-quality cooking. be.

[Structure of the invention]

The pressure cooker control device of the present invention includes a pressure vessel heated by an electric heating element, a lid for sealing the pressure vessel, and a pressure cooker that controls the pressure when the pressure inside the pressure vessel exceeds a predetermined pressure. It has a pressure regulating valve that releases steam in the container, a temperature sensor that detects the temperature of the pressure container, and a control circuit that controls heating of the electric heating element based on the output of the temperature sensor. In the pressure cooker, the control circuit includes a storage means that stores the temperature output detected by the temperature sensor at regular intervals, and compares the stored temperature output with a previous stored temperature output. and a subtractor that calculates the difference between the two, and when the difference becomes less than a certain value, the heating amount of the electric heating element is controlled.

Embodiments of the present invention will be described with reference to the drawings. 1st
In the figure, 1 is a pressure vessel, 2 is a lid that seals the pressure vessel 1 via packing 3, and 4 is a pressure vessel 1.
5 is a temperature sensor that detects the temperature of the pressure vessel 1; 6 is a control circuit that controls the amount of heat generated by the electric heating element 4 based on the output of the temperature sensor 5; 7 is a power switch. 8 is a handle of the lid 2; 9 is a handle of the pressure vessel 1; 10 is a handle of the main body 11; and 12 is a pilot lamp. 1
Reference numeral 3 denotes a pressure regulating valve provided at the center of the lid 2, which releases steam to regulate the pressure when the pressure inside the pressure vessel 1 exceeds a predetermined pressure.

As shown in FIG. 2, the control circuit 6 includes an A/D converter 14, a microcomputer 15, and a relay circuit 16.
and the triax 17 and its gate circuit 18
Therefore, microcomputer 15 has RAM 19 and CPU
20 and a ROM 21.
A series of operations of this control circuit is programmed and stored in the ROM 21, and the CPU 20 reads this program and converts the temperature signal from the temperature sensor 5 into the A/D converter 14 according to the program.
The data is digitized and captured by the RAM 19, and these signals are processed appropriately to generate signals for driving the relay circuit 16 and gate circuit 18.

Next, its effect will be explained. In FIG. 2, when the power switch a of the timer device 7 is turned on, the control circuit 6 starts operating, and when the temperature detected by the temperature detector 5 is lower than a predetermined temperature, the relay circuit 16 is turned on, and the electric heating element 4, energization is performed. On the other hand, since the gate circuit 18 is off and the triax 17 is off, the motor 7b of the timer device 7 does not rotate.

By heating the electric heating element 4, the temperature of the pressure vessel 1 rises as shown by curve A in FIG. When the predetermined temperature T _B is reached, the CPU 20 stores the temperature signal from the temperature detector 5 in the RAM 19 at regular intervals, and uses the stored temperature signal T _o as the next temperature signal T _o+1 The difference T _D
=T _o+1 -T _o is calculated, and when the temperature difference T _D is equal to or greater _than a certain value When T D reaches a ceiling and T _D becomes less than X, the power supply to the electric heating element 4 is stopped for a certain period of time L. Here, the time L is the temperature difference T _D at time T _B multiplied by a certain constant coefficient. Also, from the point when T _D becomes less than X (operating temperature T _C ), gate circuit 1
8 is turned on, the triax 17 is turned on, and the motor 7b of the timer device 7 starts driving.

After the energization to the electric heating element 4 is stopped for a certain period of time L, the energization is restarted, and after a certain period of time M, it is restarted.
The calculation T _D = T _{o +1} − _{T o} is performed. M is a time to avoid erroneously detecting a temperature valley in the pressure vessel, and is obtained by multiplying L by a certain coefficient. Thereafter, the same operation is repeated, and when the set time _ts of the timer device 7 has elapsed, the power switch 7a is turned off.
opens, all electricity is turned off, and cooking ends. In the above embodiment, after the pressure regulating valve 13 starts operating, it is re-energized after a certain period of time L of energization is stopped, but the electric power for this re-energization is also changed appropriately in consideration of heating efficiency. This is effective.

〔Effect of the invention〕

As described above, in the pressure cooker of the present invention, after the temperature sensor 5 detects that the temperature rise in the pressure vessel reaches a ceiling due to the action of the pressure regulating valve 13, the pressure cooker starts heating by intermittent heating. Since it automatically controls a certain temperature, it is possible to achieve good cooking in the same way as the weight control method, which maintains the pressure inside the pressure vessel at a constant level using the weight of the pressure regulating valve. The cooking is automatically and stably connected by the control circuit 6. Therefore, it is possible to provide a pressure cooker that has the advantages of the conventional methods (the pressure regulating valve method and the temperature control method) described at the beginning and eliminates the drawbacks, and has the effect of achieving the object of the invention.

[Brief explanation of drawings]

FIG. 1: A longitudinal cross-sectional view of an embodiment of the pressure cooker of the present invention, FIG. 2: An electric circuit diagram of an embodiment of the control circuit of the present invention, and FIG. 3: An explanatory diagram of the operation of the present invention. 1... Pressure vessel, 2... Lid, 3... Packing, 4... Electric heating element, 5... Temperature detector, 6...
...Control circuit, 7...Timer device, 7a...Power switch, 7b...Motor, 13...Pressure regulating valve,
14...A/D converter, 15...microcomputer,
16... Relay circuit, 17... Triack, 1
8...Gate circuit, 19...RAM, 20...
CPU, 21...ROM.

Claims (1)

[Claims] 1 a pressure vessel heated by an electric heating element;
a lid that seals the pressure vessel; a pressure regulating valve that releases steam within the pressure vessel when the pressure within the pressure vessel exceeds a predetermined pressure; and a temperature sensor that detects the temperature of the pressure vessel. In the pressure cooker, the pressure cooker includes a control circuit that controls heating of the electric heating element based on the output of the temperature sensor, wherein the control circuit controls the temperature output detected by the temperature sensor. It has a storage means that stores data at regular intervals, and a subtracter that compares the stored temperature output with the previous stored temperature output and calculates the difference, and when the difference becomes less than a certain value. After stopping the heating of the electric heating element for a certain period of time L, heating the electric heating element for a certain period of time M, and then again taking in the temperature output detected by the temperature sensor at a certain period of time and comparing the temperature output of the previous stage. A control device for a pressure cooker, characterized in that steam in a pressure vessel whose pressure has been adjusted to a desired pressure by repeating a series of calculation operations is intermittently jetted out from a pressure regulating valve.