JP2003052535A - Pressure vessel for electromagnetic cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure vessel for an electromagnetic cooker used in an electromagnetic cooker enabling accurate controlling of vessel temperature and safe cooking. SOLUTION: The pressure vessel for an electromagnetic cooker has a pressure pot 1 and a lid 2 for closing the pressure pot 1. In the pressure pot 1, a magnetic metallic material 1b having a specified Curie temperature is provided at least on an outside face of the bottom of the pot composed of a nonmagnetic metallic material 1a. A self-temperature controlling function is provided so as to accurately control the vessel temperature and to cook safely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic cooker pressure vessel used in an electromagnetic cooker.

[0002]

2. Description of the Related Art Conventionally, in an electromagnetic cooker, a heating coil is arranged below a top plate, and magnetic lines of force generated by the heating coil cause an eddy current in the bottom surface of the pressure vessel for the electromagnetic cooker on the top plate to generate heat. It is like this.

As a pressure vessel for such an electromagnetic cooker, a pot made of magnetic metal material (iron, SUS430 series stainless steel), a magnetic metal material (iron, SUS430 series stainless steel, etc.) and a non-magnetic metal material (aluminum, SUS30 series).
A container made of a clad material (two-layer or multi-layer) with 4 series stainless steel, etc. is often used. The temperature of the container is controlled by a thermistor installed on the back surface of the top plate on which the container is placed.

[0004]

However, since the crystallized glass used for the top plate of such a conventional electromagnetic cooker has a low thermal conductivity, the actual temperature of the pressure vessel for the electromagnetic cooker and the thermistor are not so high. The temperature difference from the sensitive temperature was large, and the thermal response was poor. For this reason, accurate temperature control cannot be performed even if it is used for pressure cooking in which the saturated vapor pressure is controlled by temperature control. For this,
The pressure cannot be controlled by the container temperature (steam temperature in the container). Therefore, a constant electric power is applied to the pressure container, and the internal pressure is adjusted by the pressure control valve provided in the pressure container.

The present invention is intended to solve the above-mentioned conventional problems and to provide a pressure vessel for an electromagnetic cooker having a self-temperature control function.

[0006]

In order to achieve the above object, the pressure vessel for an electromagnetic cooker according to the present invention is provided with a self-temperature control function by using a magnetic metal material having a predetermined Curie temperature. The pressure can be controlled by keeping the temperature constant.

[0007]

The invention according to claim 1 is a pressure cooker in which a magnetic metal material having a Curie temperature is provided on at least the outer surface of the bottom of a pan made of a non-magnetic metal material, and a lid for sealing the pressure cooker. By using the pressure vessel for an electromagnetic cooker having the above, the temperature of the pressure vessel can be kept near the Curie temperature, and as a result, the pressure in the pressure vessel can be kept constant.

The invention according to claim 2 is characterized in that the non-magnetic metal material of the pressure cooker according to claim 1 is composed of a good thermal conductor.
The unevenness of the temperature distribution due to the poor heat conduction of the magnetic metal material is eliminated, and the temperature of the cooked food inside the pressure cooker becomes uniform, improving the cooking performance.

According to the third aspect of the present invention, the weight is provided on the lid so as to release the steam when the pressure in the pressure cooker becomes equal to or higher than the first predetermined value, so that the pressure vessel is erroneously put on the gas stove. Even if it is exposed, it will prevent danger such as explosion due to increased pressure.

According to the fourth aspect of the present invention, the lid is provided with a safety valve that melts when the temperature of the lid exceeds a predetermined temperature and allows steam in the pressure cooker to escape. Even if it is exposed to the pressure, the safety valve works to drain the steam inside the pressure cooker, so it is possible to prevent the danger that the pressure cooker will explode and the pressure cooker will explode.

According to the fifth aspect of the present invention, the handle for operating the lid is provided, and the handle is located above the safety valve, so that when the metal melts and the food in the pressure cooker pops out. However, since it is covered by the handle, it does not scatter on the ceiling.

According to the sixth aspect of the present invention, the pressure of the pressure cooker on which the safety valve acts is set higher than the pressure in the pressure cooker when the weight escapes the steam, so that the metal cannot be reused once it is operated. It can be reused by making it easier to operate the safety valve that melts than the reusable weight.

According to a seventh aspect of the present invention, a packing for sealing is provided between the pressure cooker and the lid, and when the pressure in the pressure cooker reaches a second predetermined value or more, the packing is deformed and By letting the steam escape, it is possible to prevent the danger that the pressure rises and the pressure cooker explodes.

According to the eighth aspect of the present invention, the first predetermined value when the weight allows the steam to escape the second predetermined value pressure at which the packing deforms
By setting the pressure higher than the predetermined value, the safety in case of abnormality is secured.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a pressure cooker, the inside of which a food is put is made of a non-magnetic metal material 1a made of aluminum, which is a good conductor of heat and has a good thermal conductivity, and the outside is of a predetermined Curie temperature (this embodiment). The magnetic metal material 1b having a temperature of 120 ° C. (made of a nickel alloy in this embodiment) is integrally formed. The magnetic metal material 1b may be provided on the entire outer side of the non-magnetic metal material 1a, but as shown in the figure, it may be provided on at least the outer surface of the bottom of the pan. Reference numeral 2 is a lid for sealing the pressure cooker 1, and 3 is a weight that works to release steam when the pressure in the pressure cooker 1 reaches a first predetermined value (here, 250 kPa) or more. It is provided freely. Reference numeral 4 is a safety valve that works so as to melt and release steam when the temperature of the lid 2 exceeds a predetermined value (here, 135 ° C.). ing. 5 is a pressure cooker 1 and a lid 2
This is a packing for sealing the
When it exceeds a predetermined value (450 kPa in this embodiment) or more, it deforms and escapes the steam protruding from between the pressure cooker 1 and the lid 2. 6 is a handle of the lid 2 provided on the safety valve 5, and 7 is a handle provided on the pressure cooker 1.

With the above-described structure, the pressure cooker 1 is placed on the top plate of the electromagnetic cooker to start cooking, but below the Curie temperature of the magnetic metal material 1b, the alternating magnetic flux radiated from the heating coil. Is the outer magnetic metal material 1
Although it flows into b, its magnetic permeability is high, so that the eddy current induced by the alternating magnetic flux concentrates on the bottom side of the pressure cooker due to the skin effect of the high frequency current. Therefore, the alternating magnetic flux almost flows through the outer magnetic metal material 1b and is not affected by the inner nonmagnetic metal material 1a. As a result, the eddy current intensively flows on the surface of the magnetic metal material 1a (bottom side of the pan), the electric resistance of the pressure cooker becomes equivalently large, and the Joule heat generated by the eddy current is large, and the heat value of induction heating is large. Grows.

On the other hand, when the temperature exceeds the Curie temperature, the magnetic metal material 1b loses magnetism, so that the magnetic permeability decreases and the penetration depth of the eddy current (depth from the surface until the surface current decreases to a constant rate) increases. .

Therefore, the eddy current due to the alternating magnetic field also flows through the inner nonmagnetic metal material 1a, and the eddy current flows through the large cross-sectional area of the entire bottom side of the pressure cooker 1 as a whole. The amount of Joule heat generated is small and the amount of heat generated by induction heating is small.

The change in heating operation will be described in more detail below. When heating is started from room temperature, it is heated with a large amount of heat until it reaches the Curie temperature, and as a result, the pressure cooker reaches the Curie temperature. When it reaches, the pressure cooker itself automatically changes its characteristics and the amount of heat generated is reduced. Then, when the temperature of the pressure cooker decreases and becomes equal to or lower than the Curie temperature, the outer magnetic metal material 1b regains magnetism and starts heating with a large calorific value.

By using a good thermal conductor as the inner non-magnetic metal material 1a in the above, the unevenness of the temperature distribution due to poor heat conduction of the magnetic metal material 1b is eliminated, and the temperature of the cooked food inside the pressure cooker is eliminated. Becomes uniform and the cooking performance is significantly improved.

When used as a pressure cooker for cooking,
The Curie temperature of the magnetic metal material 1b is optimally 200 ° C. or lower, and a nickel alloy or an iron-chromium alloy is preferable as a specific magnetic metal material.

Furthermore, as the non-magnetic metal material 1a inside which the food is to be put, aluminum or copper, which is a good conductor of heat and has excellent heat conduction, is preferable.

On the other hand, as a method for integrating the magnetic metal material 1b with at least the outer surface of the bottom of the pan made of the non-magnetic metal material 1a, a clad material is used, bonding with a brazing material or an inorganic adhesive material, or hot pressing. You may press-contact by the method.

In the present embodiment, the Curie temperature of the outer magnetic metal material 1b is set to 120 ° C. In this case, the pressure in the pressure cooker 1 becomes about twice the atmospheric pressure, which is faster than the normal pressure. You can cook. Although the Curie temperature varies depending on the set pressure, about 110 ° C to 140 ° C is suitable.

In the unlikely event that the pressure vessel for the electromagnetic cooker is heated to the gas stove, there is a danger that it will be heated above the Curie temperature, but when the temperature of the pressure cooker 1 rises to about 128 ° C., saturated steam in the pressure cooker 1 Since the pressure becomes 250 kPa or more, the weight 3 operates and the steam in the pressure cooker 1 escapes to release the pressure cooker 1
There is no danger of explosion.

If the weight 3 operates and the hole for releasing steam is clogged with food, the weight 3 may not operate and the temperature of the pressure cooker 1 may rise further. Temperature rises to 135 ° C (saturated vapor pressure in pressure cooker 1 is 320
When the pressure reaches 1 kPa), the safety valve 4 provided on the lid 2 operates (melts) to release the steam in the pressure cooker 1 and prevent the danger such as the pressure cooker 1 exploding. At that time, since the handle 6 is provided above the safety valve 4, there is no fear that the food material inside the pressure cooker 1 will be blown out from the ceiling or the like.

Further, when the safety valve 4 does not operate due to clogging or the like, when the steam pressure in the pressure cooker 1 reaches 450 kPa, the packing provided between the pressure cooker 1 and the lid 2 is caused by the steam pressure in the pressure cooker 1. There is no danger that the pressure cooker 1 will explode, because the deformation of the pressure cooker 5 causes the steam to escape from between the pressure cooker 1 and the lid 2.

[0029]

As is apparent from the above description, in the pressure vessel for an electromagnetic cooker according to the present invention, the magnetic metal material having a predetermined Curie temperature is provided on at least the outer surface of the bottom of the pressure cooker made of the non-magnetic metal material. In combination with an electromagnetic cooker, the temperature of the pressure vessel can be kept constant and pressure can be controlled.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a pressure vessel for an electromagnetic cooker according to an embodiment of the present invention.

[Explanation of symbols]

1 pressure cooker 1a Non-magnetic metal material 1b Magnetic metal material 2 lid 3 weights 4 Safety valve 5 packing 6 handles

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K051 AC32 AC54 AD02 AD10 AD12                       AD33 CD14 CD44                 4B055 AA08 AA09 BA07 BA09 CA03                       CA41 DB14 FB01 FC06 GB25                       GC03 GC33

Claims (8)

[Claims] 1. A magnetic metal material having a Curie temperature,
A pressure vessel for an electromagnetic cooker, comprising a pressure cooker provided on at least the outer surface of the bottom of a pot made of a non-magnetic metal material, and a lid for sealing the pressure cooker. 2. The pressure vessel for an electromagnetic cooker according to claim 1, wherein the non-magnetic metal material is a good thermal conductor. 3. The pressure vessel for an electromagnetic cooker according to claim 1, wherein the lid is provided with a weight which works so as to release steam when the pressure in the pressure cooker becomes equal to or higher than a first predetermined value. 4. The electromagnetic cooker according to any one of claims 1 to 3, wherein the lid is provided with a safety valve that melts when the temperature of the lid reaches a predetermined temperature or higher to release steam in the pressure cooker. Pressure vessel. 5. The pressure vessel for an electromagnetic cooker according to claim 4, wherein a handle for operating the lid is provided, and the position of the handle is located above the safety valve. 6. The pressure vessel for an electromagnetic cooker according to claim 4, wherein the pressure in the pressure cooker on which the safety valve acts is set higher than the pressure in the pressure cooker when the weight releases steam. 7. A packing for sealing is provided between the pressure cooker and the lid, and when the pressure in the pressure cooker reaches or exceeds a second predetermined value, the deformation of the packing causes steam to escape from between the pressure cooker and the lid. The pressure vessel for an electromagnetic cooker according to claim 1, wherein the pressure vessel is an electromagnetic cooker. 8. The pressure vessel for an electromagnetic cooker according to claim 7, wherein the second predetermined value pressure at which the packing deforms is set higher than the first predetermined value pressure at which the weight operates.