JPH1154092A - Infrared ray bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the infrared ray emitting ratio and to reduce the rush current in lighting by sealing a carbon material forming a bar-like heating element into a glass tube so that the end parts of lead wires on both ends are led out of the glass tube. SOLUTION: A metal wire, for example, a tungsten wire 3 is wound in coil in contact with a heating element of bar-like carbon material 2, and a metal piece 4 consisting of an iron-nickel alloy is fixed from above the tungsten wire 3 by caulking. Further, a molybdenum thin plate 6 is electrically connected to the other end of an internal molybdenum wire 5, and an external molybdenum wire 7 forming a part of a lead wire is connected to the molybdenum thin plate 6. Even if the bar-like carbon material 2 is longitudinally expanded by a high heat in lighting, the bar-like carbon material 2 is slid within the tungsten wire 3 since the coil-like tungsten wire 3 is interposed, so that an unnecessary bending force never acts on the bar-like carbon material 2 to break it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared light bulb used for heating and heating, and more particularly to an infrared light bulb using a carbon-based material as a heating element and having a superior heat source. .

[0002]

2. Description of the Related Art As an infrared bulb conventionally used as a heat source, a tungsten spiral filament generally held at the center of a glass tube by a plurality of tungsten supports is generally used.

[0003]

However, the infrared emissivity of tungsten is as low as 30 to 39%, and the inrush current is high. In addition, the use of multiple tungsten supports to hold the tungsten spiral filament in the center of the glass tube is not easy to assemble, especially enclosing multiple tungsten spiral filaments for high output. It was difficult to do.

[0004]

SUMMARY OF THE INVENTION In order to solve these problems, an infrared light bulb of the present invention uses a rod-shaped carbon-based material instead of a conventional tungsten spiral filament. Since the infrared emissivity of the carbon-based material is as high as 78 to 84%, the infrared emissivity as an infrared light bulb is also high, and the carbon-based material has a negative resistance-temperature characteristic in which the resistance value decreases with increasing temperature. Therefore, the rush current at the time of lighting can be reduced. Further, since the rod-shaped carbon-based material has sufficient rigidity, the rod-shaped carbon-based material serving as the heating element can be held at a predetermined position of the glass tube by a small number of holding means. .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of an infrared light bulb according to an embodiment of the present invention, and FIG. 2 is a partially cut-away enlarged view thereof.

In these figures, reference numeral 1 denotes a rod-shaped glass tube made of heat-resistant glass, and 2 denotes a carbon-based substance made of crystallized carbon such as graphite, amorphous carbon, or a mixture thereof serving as a heating element. For example, a diameter of 0.5
It is formed in a rod-like body having a length of 5 mm and a length of 180 mm. As shown in FIG. 2, a metal wire, for example, a tungsten wire 3 is wound in a coil shape on both ends of the rod-shaped carbon-based material 2 in contact with the rod-shaped carbon-based material 2. Then, a metal piece 4 made of an iron / nickel alloy or the like is fixed to the rod-shaped carbon-based material 2 by caulking from above the coil-shaped tungsten wire 3.

Reference numeral 5 denotes an internal molybdenum wire forming a part of a lead wire, one end of which is fixed to the metal piece 4 by spot welding as shown in FIG. A coil-shaped portion 5a having a diameter substantially equal to the inner diameter of the coil 1 is formed. Further, a molybdenum thin plate 6 is electrically connected to the other end of the internal molybdenum wire 5, and an external molybdenum wire 7 forming a part of a lead wire is connected to the molybdenum thin plate 6.

The rod-shaped carbon-based material 2, the internal molybdenum wire 5, and the molybdenum thin plate 6
And the external molybdenum wire 7 is inserted into the glass tube 1,
By a conventionally known technique, the glass tube 1 is melt-bonded at the portion of the molybdenum thin plate 6 with an inert gas such as argon or nitrogen sealed therein, thereby forming an infrared light bulb. At this time,
The outer diameter of the coil-shaped portion 5a of the internal molybdenum wire 5 comes into contact with the inner wall of the glass tube 1, and the rigid rod-like carbon-based material 2 is supported at both ends by the coil-shaped portion 5a. , Supported at the center of the interior of the glass tube 1.

In the above configuration, the coiled tungsten wire 3 is interposed between the rod-shaped carbon-based material 2 and the metal piece 4 even if the rod-shaped carbon-based material 2 expands in the longitudinal direction due to high heat when used. Because this rod-shaped carbon-based material 2
Is such that the rod-shaped carbon-based material 2 does not break due to sliding movement in the coil-shaped tungsten wire 3 and unnecessary bending force acting on the rod-shaped carbon-based material 2.

In this embodiment, a tungsten wire having a similar coefficient of thermal expansion of carbon is used as the metal wire wound around the end of the rod-shaped carbon-based material 2. May be used instead of the metal wire. Further, in the above-described embodiment, the case where the cross section of the rod-shaped carbon-based material 2 is circular has been described. However, the polygonal shape increases the surface area and can further increase the calorific value.
Further, the heat generation can be made directional by forming it into a polygonal shape, in particular, a flat plate shape or a triangular cross section.

FIG. 4 shows an example in which a plurality of rod-like carbon-based materials 2 as heating elements are enclosed in a glass tube 1 in order to obtain stronger heat generation. A plurality of rod-like carbon-based materials 2 are integrally fixed by a metal piece 4 in the same manner as described above so that the plurality of rod-shaped carbon-based materials 2 are parallel to each other, and the metal piece 4 is fixed by one internal molybdenum wire 5 having a coil-shaped portion 5a. By supporting in the same manner as described above, a plurality of cables can be supported at the same time.

[0012]

As described above, the infrared light bulb of the present invention uses a rod-shaped carbon-based material instead of the conventional tungsten spiral filament, and the carbon-based material has an infrared emissivity of 78 to 84. %, The infrared emissivity as an infrared light bulb is high, and the inrush current at the time of lighting can be reduced because the carbon-based material has a negative resistance temperature characteristic in which the resistance value decreases as the temperature increases. Things. Further, since the rod-shaped carbon-based substance has sufficient rigidity, the rod-shaped carbon-based substance serving as the heating element can be held at a predetermined position of the glass tube by a small number of holding means. Also, a plurality of heating elements can be easily arranged.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an infrared light bulb according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of a cutout of a main part of the infrared light bulb.

FIG. 3 is an enlarged perspective view of a main part of the infrared light bulb.

FIG. 4 is a perspective view of a main part of an infrared light bulb according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass tube 2 Heating element 3 Tungsten wire 4 Metal piece 5 Internal molybdenum wire 5a Coiled part 6 Molybdenum thin plate 7 External molybdenum wire

Claims (6)

[Claims] 1. A carbon-based material serving as a heating element formed in a rod shape having lead wires electrically connected to both ends, respectively, is inserted into a glass tube such that an end of the lead wire is led out of the glass tube. An infrared light bulb characterized by being enclosed. 2. A metal wire is wound around each end of the rod-shaped carbon-based material in a coil shape, and another metal piece is fixed by caulking so as to cover the coil-shaped metal wire, and the lead is attached to the metal piece. 2. The infrared light bulb according to claim 1, wherein one end of the wire is electrically fixed. 3. The infrared light bulb according to claim 2, wherein said coiled metal wire is a tungsten wire. 4. The infrared light bulb according to claim 1, wherein a part of said lead wire is wound in a coil shape having a diameter in contact with an inner wall of said glass tube. 5. A plurality of rod-shaped carbon-based materials each having a metal wire wound in a coil shape at both ends, and another metal piece is integrally fixed by caulking so as to cover the coil-shaped metal wire. 2. The infrared light bulb according to claim 1, wherein one end of the lead wire is electrically fixed to a metal piece. 6. The infrared light bulb according to claim 1, wherein the rod-like carbon-based material has a polygonal cross section.