JPH0424603Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to an incandescent light bulb, and specifically relates to an incandescent light bulb with a foil seal structure. [Background of the invention] In an example of an incandescent light bulb with a foil seal structure, conventionally, as shown in FIG. 3, a glass envelope 80,
The sealing body 80 includes a filament coil 81 made of tungsten and a metal foil 83 made of molybdenum embedded in a crimp sealing portion 82 of the sealing body 80. Reference numeral 84 denotes an inner conductive wire extending from the end of the filament coil 81 , and the end of this inner conductor 84 is connected to the metal foil 83 and embedded in the crimp-sealed portion 82 . 85 is an outer conductor. [Problems to be solved by the invention] However, the incandescent light bulb having such a configuration has the following problems. That is, the inner conductor 84 is connected to the filament coil 81
Therefore, if a thin coil with an MG value of 40 or less is used in the coil design, when forming the crimp sealing part 82, the sealing body 80
The assembly in which the inner conductor 84 and the outer conductor 85 are connected to the metal foil 83 is positioned within the open end of the tubular glass that will constitute the glass, and the open end of the tubular glass is heated under high temperature where the glass softens. Since the crimp-sealed portion 82 is formed by pinching the crimp-sealed portion 82, the portion 86 of the inner conductor 84 buried in the crimp-sealed portion 82 is
Due to the stress between the inner conductor wire 84 and the glass, an unreasonable force is likely to be applied to the buried portion 86 of the inner conductor wire 84, and as a result, wire breakage occurs at a particularly weak point in the portion 86, resulting in a problem of poor yield. [Purpose of the invention] The present invention was made based on the above-mentioned circumstances, and its purpose is to provide an incandescent light bulb that can be manufactured without disconnection of the inner conductor. [Means for Solving the Problems] The present invention includes a glass enclosure, a filament coil disposed within the enclosure, and a metal foil for airtight sealing embedded in the crimp-sealed portion of the enclosure. In the incandescent light bulb with a foil seal structure, the thickness of the filament coil is 40 or less in terms of MG value, and the inner conductor has an inner conductor extending from an end of the filament coil. The end portion is connected to the metal foil, the metal foil is buried in the crimp sealing part, and the part of the inner conductor buried in the crimp sealing part is located on the metal foil. It is characterized by a length of 0.5 mm or less, excluding. [Operations and Effects of the Invention] According to the invention, a filament coil with a wire thickness of MG value of 40 or less is used, and the filament coil is embedded in the crimp-sealed part of the inner conductor integrally formed with the filament coil. Since the length of the part excluding the part located on the metal foil is 0.5 mm or less, the stress applied to the inner conductor by the glass of the crimp-sealed part is reduced, and as a result, the inner conductor does not break. An incandescent lamp can be formed, and ultimately an incandescent lamp with a foil seal structure can be manufactured with high yield. [Specific Configuration of the Invention] The configuration of the present invention will be specifically explained below with reference to the drawings. FIGS. 1 and 2 are explanatory diagrams showing an example of an incandescent light bulb according to the present invention. In the same figure, 10 is a sealing body made of, for example, quartz glass, 20 is a crimp sealing part, 30 is a filament coil made of, for example, tungsten, 41 and 42 are metal foils for airtight sealing made of, for example, molybdenum, and 51, 52
are inner conductive wires extending from both ends of the filament coil 30, respectively, and are formed integrally with the filament coil. That is, the filament coil 30 and the inner conductive wires 51 and 52 are formed from a single tungsten wire, and the thickness of the strand is MG value 40 or less. Note that the MG value is the weight (mg) of the wire per 200 mm of length. 61 and 62 are external conductors. The ends of the inner conductors 51 and 52 are each covered with metal foil 4.
The metal foils 41 and 42 are connected to the ends of the inner conductors 51 and 42 by, for example, spot welding, and the metal foils 41 and 42 are buried in the crimp sealing part 20, and the parts of the inner conductors 51 and 52 to be buried in the crimp sealing part 20 are Of which, metal foil 41,4
The length (hereinafter also referred to as "buried length") excluding the part located above 2 shall be 0.5 mm or less. The length of the metal foils 41, 42 is, for example, about 10 mm, and the connection length with the inner conductors 51, 52, that is, the length of the portion of the inner conductors 51, 52 located on the metal foils 41, 42 is For example, it is about 2 mm.
Further, the thickness of the metal foil is, for example, about 10 to 20 μm. Note that the edges of the inner ends of the metal foils 41 and 42 may be located on the boundary line between the crimp sealing part 20 and the internal space of the sealing body 10. According to the above configuration, the filament coil 30
Of the portions of the inner conductive wires 51, 52 integrally formed in the filament coil 30 whose thickness is 40 or less in terms of MG value and which are embedded in the crimp-sealed portion 20, the metal foils 41, Since the length L excluding the portion located above 42 was set to 0.5 mm or less, the inner conductors 51 and 52 added by the glass of the crimp sealing part 20
As a result, the stress on the inner conductor 5 becomes smaller.
It is possible to form an incandescent light bulb without causing wire breakage of 1,52 wires, and as a result, an incandescent light bulb with a foil seal structure can be manufactured with a high yield. Furthermore, since the buried length L of the inner conductors 51 and 52 is made small as described above, it is possible to increase the protrusion distance of the filament coil 30 from the crimp sealing part 20, and as a result, the crimp sealing during lighting can be made longer. The thermal load on the portion 20 can also be suppressed to a small level. [Experiment example] When incandescent light bulbs were manufactured by changing the thickness of the wire of the filament coil and the buried length L of the inner conductor, the number of defective products per 100,000 products was as follows.
The results are shown in the table. As can be understood from the results of this experiment, by employing the configuration of the present invention, incandescent light bulbs can be manufactured with an extremely high yield.

【table】

[Table] The incandescent light bulb of the present invention can be used for various purposes, and the purpose of use is not particularly limited, but it can be preferably used, for example, as an automobile light bulb, an exposure light bulb for a copying machine, etc.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a longitudinal sectional front view and a side view, respectively, showing an incandescent light bulb according to the present invention, and FIG. 3 is a longitudinal sectional front view showing a conventional incandescent light bulb. 10... Sealing body, 20... Crimp sealing part, 30...
Filament coil, 41, 42...metal foil, 5
1, 52...Inner conductor, 61,62...Outer conductor, L
... Burying length, 80 ... Encapsulation body, 81 ... Filament coil, 82 ... Crimp sealing part, 83 ... Metal foil, 84 ... Inner conductor wire, 85 ... Outer conductor wire, 86 ...
buried part.

Claims (1)

[Claims for Utility Model Registration] A foil seal structure comprising a glass envelope, a filament coil disposed within the envelope, and a metal foil for airtight sealing embedded in the crimp-sealed portion of the envelope. In the incandescent light bulb, the thickness of the wire of the filament coil is 40 or less in terms of MG value, and the inner conductor has an inner conductor extending from an end of the filament coil, and the end of the inner conductor is connected to the metal foil. and the metal foil is embedded in the crimp sealing part, and the length of the part of the inner conductor buried in the crimp sealing part excluding the part located on the metal foil is 0.5. An incandescent light bulb characterized by being less than mm.