JP2792172B2 - Pressure heating device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure heating device such as a pressure cooker used for a high-frequency heating device provided with a sensor.

2. Description of the Related Art There is a pressure cooker or a pressure cooker as a heater that seals an object to be heated, raises an internal pressure by a vapor pressure thereof, raises a boiling point, and shortens a heating time.

The heating mode using a pressure cooker or pressure cooker can be selected from a start-up mode until the pressure adjusting means operates on a weight, etc., a heating mode that maintains a constant internal pressure, and a steaming mode that stops heating and waits for the internal pressure to decrease. It is made up.

Among these heating modes, an important heating mode that has the greatest influence on the degree of heating of the object to be heated is a heating mode in which a constant internal pressure is maintained. The heating time described in a cookbook attached to a home pressure cooker or the like is generally the time required for this heating mode.

However, the rise time required for the rise mode depends on the amount of the object to be heated and the calorie of the heat source, etc. It was necessary to start the timer to set the heating time after confirming the start of operation.

In the pressure cooking of a pressure cooker, it is better to cook at high pressure (about 120 ° C and 2 atm), and to cook at low pressure (about 11
0 ° C, 1.4 atm) Some are better cooked. However, in a conventional pressure cooker using a gas or the like as a heating source, it is necessary to change the type of weight as pressure adjusting means by cooking.

In order to eliminate such troublesome operation, electric pressure cookers that detect the temperature of the cooker using a temperature sensor are already on the market.

Matsushita's SR-20 is an example of such an electric pressure cooker.
There is 3P. This is a configuration in which the internal pressure of the pan is maintained at a certain value by detecting the outer surface temperature of the bottom of the pan with a temperature sensor and controlling the power supply to the electric heater to maintain the temperature at a constant temperature. That is, if the internal temperature of the pan is maintained at 120 degrees, the internal pressure of the pan is maintained at about 2 atm.

When the temperature inside the pot is maintained at 113 degrees, the internal pressure of the pot is maintained at about 1.6 atm.

Problems to be Solved by the Invention However, in this configuration, the temperature sensor detects the temperature of the outer surface of the pot and indirectly estimates the internal temperature. Can't control.

Furthermore, since the heat conduction is delayed by the thickness of the pot, the internal temperature exceeds the temperature to be controlled and overshoots. In particular, when the amount of the object to be heated is small, the rise is fast, and such an overshoot is considerably large.

Also, if the boiled liquid sticks to the contact point between the temperature sensor and the pot, it will be difficult to conduct heat, and the internal temperature will be high,
That is, the pressure increases.

 Cooking does not go well and the risk increases.

Further, the heating time must be set using a timer, and the timing at which the timer operates is automatically controlled, but the heating is not basically automated.

Therefore, the present invention does not change the pressure cooker adjusting means such as the weight with the high-pressure cooking and the low-pressure cooking without changing each time, and can directly and accurately detect the time when the pressure adjusting means such as the weight starts to operate. An object of the present invention is to provide a pressure heating device that can quickly set a pressurized state.

Means for Solving the Problems In order to solve the above problems, the present invention provides a gas sensor for detecting a time point at which excess steam or gas released from a pressure adjusting means starts to be released or a certain time point thereafter, and a gas sensor required up to that point. And a controller that controls the power supply to the heating means based on the counted time.

The pressure heating device of the present invention detects the excess steam or gas released from the pressure adjusting means using a gas sensor, thereby directly and accurately detecting the time when the pressure adjusting means starts to operate, and thereafter detects high pressure cooking. The high-frequency heating is stopped for a predetermined period of time based on the function of the time required up to that time depending on the contents of the low-pressure cooking, and the required temperature or pressurized state can be quickly returned to.

Example Hereinafter, a pressure heating device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. A magnetron 2 serving as a high-frequency heating means is mounted in a high-frequency heating device main body 1 and supplies a radio wave into a heating chamber 3. A pressure vessel 4 made of a synthetic resin is placed in the heating chamber 3.

A gas sensor 6 is disposed on a surface of the heating chamber 3 which is closed by a door 5 which can be opened and closed and communicates with the heating chamber.
An operation panel 7 is provided on the front surface of the high-frequency heating device main body 1, a timer 8 for setting a heating time by manual heating, and an auto key for selecting a heating method according to a kind of an object to be heated and a heating category by automatic heating. 9 are arranged.

The pressure 10 serving as a pressure adjusting means of the pressure vessel 4 includes a lid 11.
And discharges excessive steam in order to maintain the internal pressure of the pressure vessel 4 at a predetermined value.

A metal holding portion 12 is fixed to the lid 11, and the lid 11 and the pressure vessel 4 can be sealed via the rubber packing 13 by sliding the lid 11 in the radial direction.

On the other hand, the power supply of the magnetron 2 is controlled by the control unit 14 via the driver 15. The signal of the gas sensor 6 for detecting the excess steam discharged from the weight 10 of the pressure vessel 4 is input to the control unit 14 via the detection circuit 16.

As such a gas sensor, a relative humidity sensor "Himamiserum" manufactured by Matsushita, a gas sensor manufactured by Figaro, an absolute humidity sensor manufactured by Shibaura Electronics, and the like, and the like can be used.

 Next, an outline of the operation of the control system will be described.

FIG. 2 is a time chart showing the steam near the gas sensor, the internal pressure of the pressure vessel, and the high-frequency output at that time.
(A) is a change in steam detected by the gas sensor 6,
(B) shows the movement of the internal pressure in the pressure vessel, and (c) shows the change in the high-frequency output at this time.

When heating is started, the temperature of the object to be heated in the pressure vessel starts to rise, and the internal pressure starts to increase soon. But weight
10 does not exist near the gas sensor 6 because it closes the opening of the nozzle. Further, when the internal pressure increases and the weight 10 starts to move, steam leaks from the opening of the nozzle, and the humidity near the gas sensor rapidly increases. The change is digital,
The gas sensor 6 can detect the point P with high sensitivity.

Pressure cooking includes cooking at a high pressure of 2 atm,
Some foods, such as rice and vegetables, will melt too much when cooked at high pressure. In addition, when there is a pig or chicken bone, glue in the bone comes out and the taste becomes worse. Therefore, it is desirable to cook such food at a low pressure of about 1.4 to 1.6 atm.

In order to quickly return to the desired low pressure, the high-frequency output is reduced to zero by the signal at point P where the steam is detected.

At the time of automatic heating, the control unit 14 counts the time T1 required from the start of heating to the detection point P of the sensor.
Experiments have revealed that the T1 time depends on the type and quantity of the object to be heated. That is, it was found that the time T1 extends almost linearly as the amount of the object to be heated increases. That is, the quantity of the object to be heated can be estimated from the time T1, and the time T2 at which the subsequent high-frequency output becomes zero based on the value of T1 and the subsequent heating time can be automatically calculated.

That is, the time T2 for setting the high-frequency output to zero is obtained by the following equation.

 T2 = KT1 + BK K: Coefficient different depending on the type of the object to be heated B: Heating time T following the constant T1 is obtained by the following equation.

T = 1T1 + C1: Coefficient which varies depending on the type of the object to be heated B: Constant Heating can be automatically terminated by such an arithmetic processing.

After the time T2 when the high-frequency output is reduced to zero, the high-frequency output is reduced to about 100 to 300 W depending on the type of the object to be heated.

The internal pressure of the pressure vessel 4 is increased by the applied high frequency output.
Balanced between 1.4 and 2 atmospheres. The high-frequency output at this time is calculated experimentally.

FIG. 3 is a flowchart showing the operation of the control unit.

When pressure cooking is selected from the auto keys 9 on the operation panel 7 and a pressure weak key such as vegetables or rice is selected during pressure cooking, heating is started by the selected key (a).

At first, heat it with full power of 500W. At the same time, the time T1 until the gas sensor 6 detects steam is counted.
(B).

When the gas sensor 6 detects the vapor, the power supply to the magnetron 2 is stopped to stop heating (c).

Time from the start of heating until the gas sensor detects evaporation
The time T2 = KT1 + B for stopping the high-frequency output from T1 is calculated (d), and the time is gradually reduced (e).

After that time, high frequency output according to the menu
Restart heating (100 W to 300 W) at P ₂ (f).

The heating time T is calculated from the time T1 from the start of heating to the time when the gas sensor detects steam.

 T = 1T1 + C (g).

When the T time gradually decreases and elapses, heating is stopped.
(H), the mode is shifted to the steaming mode (the high-frequency output is stopped).

Effect of the Invention As described above, in the pressure heating device, it is possible to directly and reliably detect the time when the pressure adjusting means starts operating by detecting the excess steam or gas released from the pressure adjusting means using the gas sensor. After that, the high-frequency output is stopped, so that the pressure can be promptly set to an appropriate pressure according to the object to be heated.

In addition, the gas sensor accurately detects the point in time when the pressure adjusting means starts to operate from the start of heating, and since this time strongly depends on the quantity of the object to be heated and the high-frequency output, the time required up to that point is counted. , The heating stop time can be determined automatically.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a pressure heating device showing one embodiment of the present invention, FIG. 2 is a time chart showing changes in steam, the internal pressure of a pressure vessel, and high-frequency heating output, and FIG. It is a flowchart which shows an operation. 1 ... high frequency heating device main body, 4 ... pressure vessel, 6 ... gas sensor, 7 ... operation panel, 10 ... weight, 11 ... lid, 14 ... control unit.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05B ⁶ /64-6/68

Claims (2)

(57) [Claims] 1. A pressure vessel for containing and sealing an object to be heated, a pressure adjusting means provided in a part of the pressure vessel, a high frequency heating means for heating the pressure vessel, and a power supply to the high frequency heating means. And a gas sensor for detecting excess steam or gas released from the pressure adjusting means, and the control section starts supplying power to the high-frequency heating means and adjusts the pressure by the gas sensor. A pressure heating device that detects a point in time when excess steam or gas starts to be released from the unit or a certain point in time after that, and stops supplying power to the high-frequency heating unit for a predetermined time from that point. 2. A method according to claim 1, wherein the power supply to the high-frequency heating means is started for a predetermined period of time, and the time when the surplus steam or gas starts to be released from the pressure adjusting means by the gas sensor or a certain time after that is detected. The pressure heating device according to claim 1, which is calculated based on a function.