JPH0824621B2 - Pressure heating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pressure heating device such as a pressure cooker or a pressure cooker equipped with a sensor.

2. Description of the Related Art There is a pressure cooker or a pressure cooker as a heater in which an object to be heated is hermetically sealed and the vapor pressure thereof raises the internal pressure to raise the boiling point to shorten the heating time.

The heating mode using a pressure cooker or pressure cooker is from a rising mode until the pressure adjusting means such as a weight is activated, a heating mode in which a constant internal pressure is maintained, and a steaming mode in which heating is stopped and the internal pressure waits for the internal pressure to drop. It is made up.

Among these heating modes, the most important heating mode that most affects the heating condition of the object to be heated is the heating mode for maintaining a constant internal pressure. The heating time described in the cookbook attached to a domestic pressure cooker is generally the time required for this heating mode.

However, the rise time required for the start-up mode varies depending on the amount of the object to be heated and the calorie of the heat source, so the person who operates the pan will be stuck to the pan until the pressure adjusting means such as a weight starts operating, and the weight will be reduced. It was necessary to confirm the point of time when the operation was started and start the timer for setting the heating time.

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

As an example of such an electric pressure cooker, SR-20 made by Matsushita
There is 3P. This is a structure in which the internal temperature of the pot is maintained at a certain value by detecting the outer surface temperature of the bottom of the pot with a temperature sensor and controlling the power supply to the electric heater so as to keep it at a constant temperature. That is, if the internal temperature of the pot is maintained at 120 degrees, the internal pressure of the pot is maintained at about 2 atm.

Further, it has a timer for setting the heating time, and the control unit does not operate this timer until the temperature sensor reaches a predetermined value. With this configuration, the timer starts running after the rise time has elapsed, ignoring fluctuations in the quantity of the object to be heated and the power consumption of the electric heater, so the person who operates the electric pressure cooker needs to be in front of the pot. Absent.

However, in this configuration, since the temperature sensor is a method of indirectly estimating the internal temperature by detecting the temperature of the outer surface of the pot, the temperature inside the pot is directly and accurately controlled. Can not do it.

Furthermore, since the heat conduction is delayed by the thickness of the pan, the internal temperature exceeds the temperature to be controlled and overshoots. In particular, when the amount of the object to be heated is small, it rises quickly, and thus such an overshoot becomes considerably large.

Also, if the broth sticks to the contact area between the temperature sensor and the pan, heat will be difficult to conduct and the internal temperature will be high.
That is, the pressure becomes high. Cooking will not work and risk will increase.

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

Therefore, the present invention directly and accurately detects the time when the pressure adjusting means such as a weight starts to operate, and freely sets the time setting of the heating mode for maintaining the most important constant internal pressure, or to the equipment. It is to provide a pressure heating device that can be automatically set by the user.

Means for Solving the Problems In order to achieve the above object, the present invention sets a gas sensor for detecting a time at which surplus vapor or gas discharged from a pressure adjusting means is discharged, and an arbitrary heating time. Equipped with a timer means and an auto key for selecting the type of object to be heated for automatically ending the heating, when the timer means is operated, excess vapor or gas is released from the pressure adjusting means by the gas sensor. Is detected,
From that time, the timer means is activated, and when the auto key is operated, the gas sensor detects the time when excess vapor or gas is released, and the time taken up to that point is counted, and based on this It is arranged to determine the heating time during which a constant internal pressure is maintained.

The pressure heating device of the present invention directly and accurately detects the time when the pressure adjusting means starts operating by detecting the excess vapor or gas discharged from the pressure adjusting means using the gas sensor, without delay. The timer means can be activated.

In addition, the gas sensor can accurately detect the time when the pressure adjusting means starts operating, and since this time strongly depends on the amount of the object to be heated and the power consumption of the heating means, the time taken until then is counted, The heating time can be automatically determined based on this.

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

FIG. 2 is a perspective view of a main body of a pressure heating apparatus according to an embodiment of the present invention, in which an operation panel 2 is provided on the front surface of the main body 1 and is a part of timer means for setting a heating time by manual heating. A timer knob 3 and an auto key 4 for selecting the heating method according to the type of the object to be heated or the heating category by automatic heating are arranged.

The pressure adjusting means or weight 5 is provided at the center of the lid body 6 and discharges excess steam in order to maintain the internal pressure of the pressure vessel 7 built in the main body at a predetermined value.

The lid handle 8 is a rod-shaped structure having a hollow interior, is fixed in the diameter direction of the lid 6, and the weight 5 is depressed in the center. By gripping the lid handle 8 and sliding the lid 6 in the radial direction, the lid and the pressure vessel 7 can be sealed. Further, the discharged steam or gas passes through the hollow inside of the lid handle 8 and is guided to a gas sensor (not shown, see FIG. 1) in the main body 1.

 Reference numeral 9 is a handle for carrying the main body 1.

Now, FIG. 1 is a block diagram showing the configuration of the pressure heating apparatus in one embodiment of the present invention.

An electric heater 10, which is a heating means, is disposed at the bottom of the pressure vessel 7, and the power supply is controlled by the controller 11 via the driver 12.

The timer knob 3 and the auto key 4 on the operation panel 2
It is connected to the control unit 11 and sets the heating time and commands the heating category.

The gas sensor 13 is arranged in the air guide path formed by the lid handle 8 and the main body 1, and detects excess vapor or gas (arrow) discharged from the dead weight 5 through the opening of the nozzle 14. To do. Reference numeral 15 is the detection circuit.

Such gas sensors include Matsushita's relative humidity sensor "Humicellum" and absolute humidity sensor "Neo-Humicellum", Figaro's gas sensor, Shibaura Electronics' absolute humidity sensor, Matsushita's pyroelectric vapor sensor, and the like. Goods are available.

Reference numeral 16 is a rubber packing that seals the lid 6 and the pressure vessel 7.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention. In this embodiment, the heating means is composed of a magnetron 17, and the pressure vessel 7 made of synthetic resin is a heating chamber.
Placed in 18. One side of the heating chamber 18 that can be opened and closed 19
The gas sensor 13 is arranged at a site that is closed by and communicates with the heating chamber.

In this embodiment, as compared with the embodiment shown in FIGS. 1 and 2, the space formed by the main body 1 and the lid handle 8 is replaced by the heating chamber 18, and the pressure vessel 7 is taken out. Then, the heating chamber 18 can be used as a microwave oven.

Next, an outline of the operation of the control system will be described. FIG. 4 is a time chart showing the vapor in the vicinity of the gas sensor and the internal pressure of the pressure vessel. FIG. 4A shows changes in the vapor detected by the gas sensor, and FIG. 4B shows the internal pressure of the pressure vessel at this time. It represents a movement.

When heating is started, the temperature of the object to be heated in the pressure vessel begins to rise, and eventually the internal pressure begins to rise. However, there is no vapor in the vicinity of the gas sensor because the weight blocks the nozzle opening. This is the rising mode.

Then, when the weight starts moving, steam leaks from the opening of the nozzle, and the humidity near the gas sensor rapidly increases.
The change is digital, and the humidity sensor can detect point P with high sensitivity.

Unlike the conventional method in which a desired value is controlled as an absolute value by a temperature sensor, relative control is performed as to whether or not steam is generated, so stable detection can be realized.
Further, since the excess vapor is wetted out from the weight to directly detect that the internal pressure has reached the predetermined value, there is no operation delay due to heat conduction as in the conventional temperature sensor method.

During manual heating, the timer means starts operating from point P. This is the heating mode that has the greatest effect on the heating condition of the object to be heated.

When the set heating time elapses, the power supply to the heating means is stopped and the steaming mode is waited for until the internal pressure decreases.

During automatic heating, the detection point P of the sensor from the start of heating
The control unit counts the time T ₁ required for the control. Experiments have shown that the rise time T ₁ depends on the type and quantity of the object to be heated. The table below shows a part of the results of such an experiment.
A magnetron having a high-frequency output of 0 watts, a food as the object to be heated, and a pyroelectric vapor sensor manufactured by Matsushita as the gas sensor were used.

From the results of this experiment, it is understood that the detection time T ₁ of the gas sensor extends almost linearly as the amount of the heated object increases. However, it is also found that the inclination is subtly different depending on the type of object to be heated.

Therefore, if you input the type of object to be heated into the control unit,
The amount of the object to be heated can be estimated from the detection time of the gas sensor, that is, the time T ₁ required for the rising mode, and the subsequent heating time can be automatically calculated based on this T ₁ value.

 That is, the heating time T is calculated by the following equation.

T = KT ₁ + B K: Coefficient that differs depending on the type of object to be heated B: Constant By this arithmetic processing, heating can be automatically terminated. In this example, the heating time was obtained by a linear equation, but a higher-order calculation equation may be used depending on the experimental result.

FIG. 5 is a flowchart showing the operation of the control unit.

When heating is started, it is first determined whether it is automatic heating or manual heating (a).

In the case of manual heating, it is checked whether or not a predetermined amount of vapor is detected by the gas sensor (b), and after reaching point P, the heating time set in the timer is gradually reduced (c).

When the heating time elapses (d), the heating is stopped (e) and the steaming mode is entered.

In the case of automatic heating, it is checked whether or not a predetermined amount of vapor has been detected by the gas sensor (f), and before the point P is reached, that is, in the rising mode, T ₁ time is counted (g).

When the point P is reached, the counted time T ₁ is multiplied by a predetermined count K corresponding to the selected auto key to calculate the heating time (h). Then, this is gradually reduced (i).

When this heating time KT ₁ + B has elapsed (j), heating is stopped (k) and the mode shifts to the steaming mode.

EFFECTS OF THE INVENTION As described above, in the pressure heating device of the present invention, by detecting the excess vapor or gas discharged from the pressure adjusting means using the gas sensor, the time point when the pressure adjusting means operates can be directly assured. Can be detected. In addition, the time setting of the heating mode that maintains a constant internal pressure, which is the most important in pressure heating, can be freely set by timer means, and the type of object to be heated etc. can be selected by operating the auto key You can set it automatically.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of a pressure heating apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of the same body, and FIG. 3 is a pressure according to another embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of the heating device, FIG. 4 is a time chart showing changes in steam and internal pressure, FIG. 4A is a diagram showing changes in steam detected by a gas sensor, and FIG. FIG. 5 is a diagram showing the movement of the internal pressure of the pressure vessel at this time, and FIG. 5 is a flowchart showing the operation of the control unit. 3 ... Timer knob, 4 ... Auto key, 5 ... Pressure adjusting means, 7 ... Pressure vessel, 11 ... Control section, 13 ... Gas sensor.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Mitsuo Akiyoshi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-53-83871 (JP, A) JP-A-60-177598 (JP, A) Actually opened 61-110330 (JP, U) Actually opened 57-202827 (JP, U)

Claims (1)

[Claims] 1. A pressure vessel for accommodating and sealing an object to be heated, a pressure adjusting means provided in a part of the pressure vessel, a heating means for heating the pressure vessel, and a power supply to the heating means. A control unit, a timer means for setting an arbitrary heating time, an auto key for selecting the kind of the object to be heated for automatically ending the heating, and an excess steam or gas discharged from the pressure adjusting means. An air passage leading to the air passage, and a gas sensor for detecting steam or gas fixed to the air passage, and the controller controls the gas sensor to generate excess steam from the pressure adjusting means when the timer means is operated. Alternatively, the time when the gas is released is detected, and the timer means is activated from that time, and when the auto key is operated, the control unit controls the pressure by the gas sensor. A pressure heating device configured to detect the time when excess steam or gas is released from the stage, count the time required until then, and determine the heating time based on which the continuous constant internal pressure is maintained .