JPH083998B2 - Manufacturing method of filament for light bulb - Google Patents

Description

The present invention relates to a method for producing a filament using a filament, such as a halogen bulb.
Especially, the wire connection part of the filament used with a large current,
The present invention relates to a method for manufacturing a filament provided with a sub coil.

[Conventional technology]

Conventionally, as shown in FIG. 5, when a filament 21 of a light bulb used for a large current such as a headlamp bulb is connected to a lead-in wire 23 by spot welding, the filament 21 is compared with the lead-in wire 23. It is thin and has a small heat capacity, and because the contact area is small, the current concentrates,
In order to cause problems such as brittleness due to temperature rise of this wire connection portion, as shown in the figure, a sub-coil 22 fitted to the filament 21 is formed with an appropriate conductive member, and the sub-coil 22 is connected to the wire. The measure was to insert it in the line part.

[Problems to be solved by the invention]

However, when inserting the sub-coil 22 described above, since the filament 21 itself is fine, automatic insertion by a machine or the like is impossible, and it is necessary to manually insert each one. However, for this reason, there is a problem in that this type of light bulb becomes expensive, and there is a problem in production that the mass productivity is poor and quality control is difficult.

[Means for solving problems]

The present invention, as a specific means for solving the above-mentioned conventional problems, in a method for manufacturing a filament for a light bulb in which a tungsten wire is wound around a core wire made of a soluble wire such as molybdenum and then the core wire is melted into a coil shape. , The fusible wire finer than the tungsten wire is previously wound as a sub-coil, and the tungsten wire is wound around the core wire and then the sub-coil other than a necessary place such as the core wire and a connecting wire is formed. By providing a method for producing a filament for a light bulb, the sub-coil can be formed at the same time when the filament is produced, and the conventional problems are solved.

〔Example〕

Next, the present invention will be described in detail based on an embodiment shown in the drawings.

Reference numeral 1 in FIG. 1 is a tungsten wire for forming a filament of a light bulb, and the tungsten wire 1 is used as a core, and a fusible wire 2 such as a molybdenum wire thinner than this is used to form a winding for a sub coil. Is done. Since this winding process is almost the same as the conventional filament forming process, it can be easily and automatically performed by applying a conventional winding machine, etc. The wire diameter, pitch, etc. most suitable for the purpose may be selected based on the data accumulated from the above.

As shown in FIG. 2, the tungsten wire 1 on which the fusible wire 2 is wound in this manner is wound on the core wire 3 made of a member similar to the one on which the sub-coil is formed, such as molybdenum, by a normal filament forming method. To be a predetermined shape. At this time, naturally, a conventional winding machine can be used.

After that, as shown in FIG. 3, a resin coating 5 is applied to a necessary portion of the soluble wire 2 and the soluble wire 2 is immersed in a solution 4 such as aqua regia (mixed solution of concentrated hydrochloric acid and concentrated nitric acid).
And the core wire 3 is melted. Since the step of melting the core wire 3 is a step that has been conventionally performed, no new equipment is particularly required when implementing the present invention.

The sub-coil 2a is provided at a predetermined position, that is, the connecting wire portion 1a for connecting wires, as shown in FIG. 4, without preparing any new equipment for carrying out the present invention by the manufacturing method described above. The filament 6 thus obtained is obtained.

It should be noted that although the above description has been made with reference to the most basic shape of the filament 6, it goes without saying that, for example, performing it on a double coil filament is a very easy modification for those skilled in the art and can be easily implemented. In addition, the portion where the sub-coil 2a is left is not limited to the connecting wire portion 1a described above. It is also free and does not impair the gist of the present invention.

〔The invention's effect〕

As described above, in the method for manufacturing a filament for a light bulb according to the present invention, a fusible wire which is thinner than the tungsten wire is previously wound as a sub-coil, and the tungsten wire is wound on the core wire and then the core wire is wound. With the manufacturing method of melting the sub-coil other than the required place such as a wire connection part, without manually inserting the bulb filament for which this kind of sub-coil is provided,
In addition, it can be automatically obtained without making a large change to the production equipment that has been conventionally used, and has an excellent effect on cost reduction and production rationalization.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first step of an embodiment of a method for manufacturing a filament for a light bulb according to the present invention, FIG. 2 is an explanatory view showing a step of similarly winding a filament winding, and FIG. 3 is a melting step. 4 is an explanatory view showing a completed state,
FIG. 5 is an explanatory view showing a conventional example. 1 ... Tungsten wire 1a ... Connection part 2 ... Soluble wire 2a ... Subcoil 3 ... Core wire 4 ... Solution 5 ... Resin coating 6 ... Filament for bulb

Claims (1)

[Claims] 1. A method of manufacturing a filament for a light bulb, comprising winding a tungsten wire around a core wire made of a soluble wire material such as molybdenum and then melting the core wire to form a coil, wherein the tungsten wire is preliminarily thinner than the soluble wire material. As a sub-coil, and the tungsten wire is wound around the core wire, and then the core wire and the sub-coil other than a required place such as a connecting portion are melted. .