JPS63269475A - Heating cooker - Google Patents

Abstract

PURPOSE:To improve thermal efficiency and remove the difference in thermal efficiency in spite of variation in the material quality and the surface condition of a cooker by forming a supporting plate of a crystallized glass which shuts off light in a near infrared ray region while radiating light in a far infrared ray region. CONSTITUTION:A supporting plate 8 consists of a crystallized glass which shuts off light in a near infrared ray region while radiating light in a far infrared ray region. That is, the infrared rays in a near infrared ray region heading for a cooker 20 from an infrared ray lamp 10 is shut off by a supporting plate 8. The shut-off near infrared rays heat the supporting plate 8 so that the supporting plate 8 itself radiates light in the far infrared region. Accordingly, the cooker 20 is heated mainly by the far infrared rays radiated from the supporting plate 8 so that a commonly-used cooker has good absorption of the far infrared rays. Thereby, thermal efficiency is generally improved, with a small difference in an absorption rate according to materials thus removing difference in thermal efficiency in spite of variation in the material quality the surface condition or the shape of the cooker.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a cooking device using an infrared lamp as a heat source.

(Prior art) Conventionally, as a heating cooking device, Japanese Patent Application Laid-Open No. 59-123180
As shown in Japanese Utility Model Application No. 60-135076 filed by the present applicant, there are known devices that use a tubular infrared lamp as a heat source.

This device includes a support plate on which a cooking container containing food to be cooked is placed above the infrared lamp, and
A heat insulating material is provided below this infrared lamp.

According to such a heating cooking device, infrared rays emitted from an infrared lamp are directed toward the support plate, and the infrared rays are transmitted through the support plate to heat the cooking container placed on the support plate.

The above-mentioned support plate is used to place and support the cooking container, but this support plate must have the property of transmitting infrared rays so that the infrared rays emitted from the infrared lamp reach the cooking container. It is said that

For this reason, conventionally, the support plate has been made of quartz-based crystallized glass.

(Problems to be Solved by the Invention) However, as shown by the broken lines in Figures 1 and 3, the conventional support plate made of quartz-based crystallized glass has a transmittance of about 80% in the near-infrared region. Compared to this, the transmittance in the far infrared region was small.

In general, near-infrared rays have the advantage of being quick-acting in heating cooking vessels quickly. However, the absorption efficiency of near-infrared rays differs depending on the material and surface condition of the cooking container, and even if the same amount of human power is applied to the infrared lamp, the degree of heating of the cooking container will vary, resulting in a large difference in thermal efficiency. There is.

For example, when heating with near-infrared rays, a cooking container made of aluminum with a polished surface has a thermal efficiency of about 58%.
Similarly, a cooking container made of iron with a polished surface had a thermal efficiency of about 56%, whereas a cooking container made of black-painted brass had a thermal efficiency of about 66%.

The present invention aims to provide a heating cooking device that has improved overall thermal efficiency and eliminates the difference in thermal efficiency even if the cooking container is made of different materials or has different surface conditions.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, the support plate is shielded from near-infrared rays,
However, it is characterized by being made of crystallized glass that emits far-infrared radiation.

(Function) According to the present invention, the near-infrared region of the infrared rays directed from the infrared lamp toward the cooking utensil is blocked by the support plate. The blocked near-infrared rays heat the support plate, so that the support plate itself emits far-infrared rays. Therefore, the cooking container is heated mainly by far infrared rays emitted from the support plate. Far-infrared rays have good absorption properties in commonly used cooking containers, which improves overall thermal efficiency, and there is little difference in absorption rate depending on the material, so even if the material, surface condition, or shape of the cooking container is different. The difference in thermal efficiency disappears.

(Example) The present invention will be described below based on an example shown in the drawings.

Reference numeral 1 shown in FIGS. 1 and 2 is a casing constituting the main body of the cooking utensil. This casing 1 is made of, for example, a sheet metal, and has a box shape with an opening 3 surrounded by a flange 2 on the top surface. There is. There are heat radiation holes 4 on the side wall of the casing l.
... has been established.

A dish-shaped support member 5 is accommodated in the casing l.

This support member 5 is made of microporous ceramic, for example, 5
It is made of a heat insulating material such as I02, and its upper end is fixed to the flange 2 of the casing I, and its periphery' faces the side wall of the casing I with a gap therebetween. This support member 5 forms a partition between the center and end portions of an infrared lamp 10, which will be described later.

Note that another heat insulating member may be provided between the bottom wall of the support member 5 and the bottom wall of the casing l, but an air heat insulating layer may be used.

An infrared reflector B is formed on the inner surface of the support member 5 over substantially the entire surface.

A plurality of insertion holes 7 are formed in the same plane on both opposite side walls of the dish-shaped support member 5, and in these insertion holes 7, tubular infrared lamps 10 are formed.・Multiple pieces are inserted and supported.

The tubular infrared lamp IO includes a tungsten filament 12 supported by a plurality of support rings 13, located on the tube axis within a straight tube bulb 11 made of quartz glass. Both ends of the filament 12 are connected to molybdenum foils (not shown) sealed in pinch seals 14.14 formed at both ends of the bulb 11, and these molybdenum foils are connected to external lead wires (not shown). has been done.

Inside the bulb 11, halogen gas is sealed together with an inert gas such as argon or nitrogen.

Both ends of such a tubular infrared lamp 10 are inserted into insertion holes 7 formed in both side walls of the dish-shaped support member 5, as shown in FIG. Supported. This infrared lamp 10 includes a support member 5
External lead wires led out to the pinch seal portions at both ends projecting to the outside are connected to terminals (not shown) of the sockets 19, 19.

) In this example, four tubular infrared lamps IO and
... are arranged so as to be parallel to each other and located on substantially the same plane.

A support plate 8 is fixed to the upper opening of the dish-shaped support member 5 so as to cover the opening 3 of the casing 1.

The support plate 8 of this embodiment is made of crystallized glass that blocks near-infrared rays and emits far-infrared rays.

A cooking container containing food to be cooked, such as a pot 20, is placed on the support plate 8.

The operation of the embodiment with such a configuration will be explained.

When the tubular infrared lamps 10 are powered on and turned on, the tungsten filament 12 becomes red hot and emits light. Since this tubular infrared lamp IO is a halogen lamp, the color temperature of the filament is 1600~
It reaches 2400'K and emits light in a wide range from visible light to far infrared rays, but its maximum output is particularly around a wavelength of 1200 nm.

Such radiation passes through the bulb 11 of the lamp 10, and part of it goes directly to the support plate 8, while the rest goes to the inner surface of the support member 5 and hits the infrared reflector 6 formed on the inner surface of the support member 5. It is reflected and goes towards the support plate 8.

Since the support plate 8 is made of crystallized glass that cuts near-infrared rays, approximately 25
Near-infrared rays of 00 nm or less are blocked, and therefore the amount reaching the cooking container 20 placed on the support plate 8 is reduced.

A part of the near-infrared rays blocked by the support plate 8 heats the support plate 8 itself.

The remaining near-infrared rays are reflected downward, toward the inner surface of the support member 5, reflected by the infrared reflector B formed on the inner surface of the support member 5, and directed toward the support plate 8 again.

By repeating such reflection, heat is trapped in the space surrounded by the support plate 8 and the support member 5, so the temperature of this space increases, and this heat heats the support plate 8. Therefore, the temperature of the support plate 8 rises and it emits far infrared rays by itself.

For this reason, the cooking container 20 is mainly heated by far infrared rays emitted from the support plate 8, and the rest is heated by heat conduction from the support plate 8.

Since far-infrared rays have excellent absorption properties, they are well absorbed without being affected by the material, surface condition, shape, etc. of the cooking container 20. Therefore, thermal efficiency is improved and variation in thermal efficiency from container to container is also reduced.

FIG. 3 shows the results of measuring the transmittance of near-infrared rays when the support plate 8 of the above example was used.

The lamps used were four 200 V'500 W paper tube-shaped halogen lamps, the solid line indicates the cooking device of the present invention using crystallized glass having the characteristics of the present invention as the support plate, and the broken line indicates the cooking device using quartz-based crystallized glass. These are the characteristics of each conventional cooking device.

From Figure 3, while the conventional cooking device had a transmittance in the near-infrared region of approximately 80%, the cooking device of the present invention has a transmittance in the near-infrared region that has been significantly reduced to about 20%. I know what you're doing.

The table below shows the results of measuring the thermal efficiency depending on the material of the cooking container for the heating cooking device of the present invention and the conventional heating cooking device.

From the results in the table above, it can be seen that the cooking device of the present invention improves thermal efficiency no matter what material the cooking container is made of, and also reduces variations in thermal efficiency based on differences in materials.

In the above embodiment, the infrared lamp is a halogen lamp, but the present invention is not limited to this, and the lamp may be a lamp that does not contain halogen, and the shape may be a straight tube. However, it may be curved into a ring shape, a spiral shape, a U-shape, or the like.

[Effects of the Invention] As explained above, according to the present invention, the support plate blocks near-infrared rays and is heated directly or indirectly by the blocked near-infrared rays, so that the support plate itself is exposed to far-infrared rays. radiates and therefore emits far infrared radiation towards the cooking vessel. For this reason, cooking containers are heated mainly with far infrared rays, which improves thermal efficiency due to good heat absorption, and can reduce variations in thermal efficiency due to the material, surface condition, shape, etc. of the cooking container, and the types of cooking containers that can be used. becomes wider.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
2 is a perspective view of the entire heating cooking device, and FIG. 3 is a characteristic diagram of transmittance. ■... Casing, 5... Support member, B... Infrared reflective coating, 8... Support plate, 10... Tubular infrared lamp, 20... Cooking container. Applicant's representative Patent attorney Takehiko Suzue Day 1, Day 20 Ichika Ko

Claims (1)

[Claims] A support plate is provided above the tubular infrared lamp, a cooking container containing food to be cooked is placed on the support plate, and the cooking container is heated by the infrared lamp. The heating cooking apparatus, wherein the support plate is formed of crystallized glass that blocks near-infrared rays and emits far-infrared rays.