JPH0249633Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a halogen light bulb having a structure in which the bulb casing is made of a translucent alumina tube, and the end of the bulb is sealed with an end cap made of conductive cermet. Regarding light bulbs.

[Prior art and problems] When a halogen light bulb made of a quartz container is used as a heat source for heating during semiconductor manufacturing, it must be lit at a temperature higher than the softening point of quartz to meet the desired temperature conditions. The drawback was that it was not available.

Therefore, translucent alumina tubes that can withstand high temperature and high pressure metal or halogen vapors have been developed, and high-pressure sodium lamps used as arc tube enclosures have already been put into practical use, and metal halide lamps have also been proposed. As shown in Japanese Publication No. 58-1510, a halogen light bulb has been proposed that uses an alumina tube as the light bulb casing and uses conductive ceramic at its end.

However, although tungsten metal is generally used as the filament material for such light bulbs, there is a problem in the connection between the filament and the conductive ceramic, which has not yet been completely solved. The biggest drawback is the problem of connecting tungsten metal and non-ductile ceramic, and since direct welding is not possible during manufacturing, they are connected by mechanical bonding means, but the heat generated by each material due to turning on and off. The difference in expansion coefficient caused the connection to become loose, and eventually the filament sometimes fell off.

[Purpose of the invention] The purpose of the invention is to use a chemically stable and devitrified-free translucent alumina tube as the bulb enclosure, and to seal the end with an end cap made of conductive cermet. In halogen light bulbs, which allow for higher bulb surface temperature designs than conventional ones, the electrical connection is ensured by eliminating any loosening caused by heat cycles at the connection between the filament and the conductive cermet when the light is turned on and off. The goal is to make it more durable and extend its lifespan.

[Summary of the invention] The present inventors applied tension to the filament latching portion formed at the tip of the internal lead rod of the end cap, and by stretching both ends of the filament, lighting could be achieved. It has been found that an accurate contact can be obtained without loosening of the connection due to elongation due to thermal expansion of the filament.

As a result, when used as a heat source for a heating furnace using a halogen bulb, it is possible to provide a halogen bulb with a high thermal design margin and excellent vibration resistance.

[Structure and operation of the invention] Hereinafter, an embodiment of the invention will be described based on FIG. 1.

In Fig. 1, numeral 1 is a light bulb casing made of a translucent alumina tube, the end of which is La ₂ O ₃ −Y ₂ O ₃ −
It is sealed with an end cap 3 made of a conductive cermet made of tungsten-alumina via a SiO ₂ sealing material 2 . The inner side of the tube of this end cap has a structure in which an internal lead rod 4 is integrally molded, and a filament hooking part 5 is formed at the tip of the end cap, for example, as shown in FIG. 2a, It has a structure in which holes 6 are provided.

Both ends of a filament 7 made of tungsten are connected to the hole, and the connected filament is suspended in the tube under tension at all times.

Hydrogen bromide is sealed inside such a tube, and 8 in the figure indicates an external lead rod.

FIG. 2b shows another embodiment of the filament hook, in which a notch 9 is formed in the internal lead rod to form a hook shape.

In order to manufacture such a light bulb, first, a recrystallized filament that is shorter than the total length of the alumina tube is attached to one end of the translucent alumina tube at the filament hooking part of the internal lead rod of one end cap. The end cap with one end connected is sealed via a sealing material.

and pulling the other end of the filament from the other end opening of the alumina tube with tweezers or the like;
The other end of the filament is connected to the filament hooking part of the internal lead rod of the other end cap, so that the filament is stretched under tension, and the other end cap is connected to the alumina pipe as described above. Seal on the other end.

[Effects of the invention] As is clear from the above description, the halogen light bulb according to the invention has a filament hook formed at the tip of the internal lead rod of the cermet end cap of the light bulb casing made of translucent alumina. By hanging the filament in a state where the filament is under tension, a light bulb with excellent vibration resistance and a long life can be obtained without loosening of the filament connection part due to repeated lighting cycles. and,
It is possible to obtain a halogen light bulb that is optimal as a heat source for heating, etc.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal sectional view of a halogen light bulb showing an embodiment of the present invention, and FIGS. 2a and 2b are sectional views of essential parts thereof.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A halogen light bulb in which the end of a light bulb enclosure 1 made of a translucent alumina tube is sealed with an end cap 3 made of conductive cermet, and halogen gas is sealed inside the light bulb. In the halogen light bulb, both ends of a filament 7 are connected to a filament hook 5 formed at the tip of the internal lead rod 4 of the end cap, and the filament is suspended under tension. 2. The halogen light bulb according to claim 1, wherein the filament hook is a hole 6. 2. The halogen light bulb according to claim 1, wherein the filament hook is a notch 9.