JPH09153350A - Manufacture of small bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a small bulb by which a highly reliable small bulb is manufactured with excellent yield and with ease. SOLUTION: A mount 6 which is formed by mounting a filament 6c on one end side of a pair of lead wires (lead-in wires) 6b, 6b' airtightly interposed in an approximately elliptical (oval) bead glass 6a is inserting arranged in a cylindrical glass bulb 5 whose one end is sealed as positioning the filament 6c on the sealed end side. As positioning the bead glass 6a of the inserting arranged mount 6, the sealed portion outer peripheral face of the glass bulb 5 is heated and pressurized so as to shrink the diameter of a sealed portion 5a into approximately elliptical. The bead glass 6a of the mount 6 is positioned at and locked with the shrunk sealed portion 5a of the glass bulb 5, and by heating and welding in an exhausted state, the bead glass 6a and the sealed portion 5a are sealed and integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a small light bulb, and more particularly to a method for manufacturing a small light bulb suitable for mounting on a wiring board for an instrument of an automobile.

[0002]

2. Description of the Related Art With the development of the automobile industry, automobile instrument display devices are diversified, and in response to the diversification of instrument display devices, various types of display means have been developed. In these display means, the small light bulb used as a light source is required to have high brightness and long life. In responding to such demands, the probability and development / advancement of a more effective manufacturing technique for a small light bulb are indispensable. For example, a sealing means for a glass bulb forming an arc tube has been developed.

2 (a) to 2 (e) schematically show the steps of manufacturing a conventional small-sized electric bulb in the order of steps, and first, as shown in a sectional view in FIG. 2 (a). , A cylindrical glass bulb 1 with an inner diameter of ~ 1 mm, sealed at one end (open at the other end), and a spherical (circular) bead glass 2a
A pair of lead wires (introduction wire) that are hermetically sealed and inserted
A mount 2 is prepared in which a filament 2c for light emission is mounted on one end side of b and 2b '.

Next, after the mount 2 is inserted and arranged in the glass bulb 1 with the filament 2c as the sealing end side,
As shown in a sectional view and a plan view in FIG. 2 (b), the bead glass 2a of the mount 2 which is inserted and arranged is a sealing end side,
While the outer peripheral surface of the sealed portion 1a of the glass bulb 1 is heated by the burner 3, the diameter of the sealed portion 1a is reduced to a substantially circular shape by pressing the roller 4 as shown in a sectional view in FIG. 2 (c). To do. In the step of heating and reducing the outer diameter of the sealed portion 1a of the glass bulb 1, the glass bulb 1 and the burner 3 are relatively rotated to heat and shrink the sealed portion 1a substantially uniformly. The diameter of the mount 2 is the diameter of the circular (or spherical) bead crow 2a of the mount 2 at the reduced inner diameter.
Is locked, and there is still a space left on the sealed end side of the glass bulb 1 for exhausting air.

Next, the glass bulb 1 in which the diameter of the sealed portion 1a is reduced is inverted, and as shown in a sectional view in FIG. 2 (d),
While the circular or spherical bead glass 2a of the mount 2 is locked (contacted) with the circularly reduced inner wall portion of the sealed portion 1a, the outer peripheral portion is heated by a burner (not shown) while exhausting air. , Pressure is applied to weld and seal the sealed portion 1a and the bead glass 2a. At this time, if necessary, a part of the opening end side including the sealed portion 1a may be crushed and sealed. After that, the open end side of the glass bulb 1 and the lead wire 2 of the mount 2
By cutting b and 2b ′ to the required length and shaping them, a compact light bulb as shown in cross section in FIG. 2 (e) can be obtained.

[0006]

However, the manufacturing method of the small-sized light bulb still has the following problems. That is, in a state in which the circular (or spherical) bead glass 2a provided in the mount 2 and the sealed portion 1a diameter of the glass bulb 1 having a substantially circular diameter are locked and brought into contact with each other,
In melt-sealing each other, first, it is necessary to properly position the both. However, in the case of this manufacturing method, the lead wires 2b, 2b of the mount 2 are pushed by pressing the roller 4 in the step of reducing the circular diameter of the sealed portion 1a that is locked and brought into contact with the circular bead glass 2a. ′ Is deformed, and the sealed portion 1a having a circular reduced diameter and the circular bead glass 2a do not have a required locking / contacting state,
They may be melt sealed together. That is, in this type of small light bulb, since the glass bulb 1 is a thin tube and the mount 2 has a minute structure, there is a problem that a required small light bulb cannot be obtained due to a slight error or deviation in processing accuracy. For example, when the locking / contact between the reduced diameter sealed portion 1a and the circular bead glass 2a is slightly deviated, the filament 2c is inclined and comes into contact with the inner wall surface of the glass bulb 1, resulting in blackening. It causes the generation and shortening of life. The problems of blackening and shortening of life greatly affect the manufacturing cost problem, reliability, and manufacturing yield of a small light bulb, and can be said to be a serious problem in a small light bulb manufacturing method that takes mass productivity.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a manufacturing method capable of easily manufacturing a compact light bulb having a high yield and high reliability.

[0008]

According to a first aspect of the present invention, a filament is mounted on one end side of a pair of lead wires (introducing wires) in which a substantially oval (oval) bead glass is hermetically inserted. The mounting of the filament into a cylindrical glass bulb with one end sealed with the filament as the sealing end side, and the bead glass of the mount that has been inserted and placed as the sealing end side, and The process of heating and pressurizing the outer peripheral surface of the sealed portion to reduce the diameter of the sealed portion into an almost elliptical shape, and positioning and locking the bead glass of the mount to the reduced sealed portion of the glass bulb. And a step of sealing and integrating the bead glass and the sealed portion by heating / welding in an exhausted state. The invention according to claim 2 is a mount in which a filament is mounted on one end side of a pair of lead wires (introducing wires) in which a substantially oval (oval) bead glass is airtightly inserted, and one end is sealed. In a cylindrical glass bulb, a step of inserting and arranging the filament as a sealing end side, a bead glass of the mount that is inserted and arranging as a sealing end side, and heating the outer peripheral surface of the sealed portion of the glass bulb,
By the process of reducing the diameter of the sealed portion into an almost elliptical shape, and heating and welding in the state where the bead glass of the mount is positioned and locked to the reduced diameter sealed portion of the glass bulb,
A method of manufacturing a small light bulb, comprising: a step of sealing and integrating a bead glass and a sealed portion; and a step of sealing the filament sealing region of the mount after exhausting the air.

That is, in the method for manufacturing a small light bulb of the present invention, the bead glass of the mount portion to be sealed is made substantially elliptical (ellipsoidal), and the diameter reduction (inner diameter) of the sealed portion of the glass bulb is elliptical. The main point is to make it easier to secure the positioning accuracy for locking and contacting the bead glass and the portion to be sealed (diameter reduction) by using the (oval shape).

In the method for manufacturing a small light bulb according to the present invention, the glass bulb forming the arc tube and the mount for sealing have substantially the same standard shape and dimensions as those of a small light bulb used as a light source for instrument display. To be selected.
For example, a cylindrical glass bulb having an inner diameter of 4.5 to 5.0 mm and having one end sealed is used, and a standard mount sealed in the glass bulb is used except for the bead glass shape.

According to the first and second aspects of the present invention, there is provided a mount provided with a bead glass having a substantially elliptical shape (oval shape).
With the bead glass inserted and mounted as the sealing end side of the glass bulb, the inner diameter of the sealed portion of the glass bulb is reduced to an elliptical shape. Therefore, the positioning and locking / contact of the bead glass with respect to the reduced diameter sealed portion of the glass bulb secures high accuracy, and the bead glass and the sealed portion are sealed and integrated in this state. . In other words, the lead wire (introduction wire) is prevented from being deformed, and the mount is sealed with high accuracy in a predetermined position and direction. Therefore, the risk of filament contact with the inner wall surface of the glass bulb is completely eliminated and avoided. Therefore, a high-quality compact light bulb can be manufactured with high yield and at low cost.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below with reference to FIGS. 1 (a) to 1 (e).

FIGS. 1 (a) to 1 (e) are views schematically showing the embodiments of the method of manufacturing a compact electric bulb according to the present invention in the order of steps.

First, as shown in a sectional view in FIG. 1 (a), a cylindrical glass bulb 5 having an inner diameter of 4.5 to 5.0 mm with one end sealed (the other end is open), and a substantially elliptical shape (oval shape). )
Of a pair of lead wires (introducing wires) 6b and 6b 'which are hermetically inserted through the bead glass 6a of
Prepare a mount 6 on which 6c is mounted.

Then, after the mount 6 is inserted and arranged in the glass bulb 5 with the filament 6c as the sealing end side,
As shown in a sectional view and a plan view in FIG. 1 (b), the bead glass 6a of the mount 6 which is inserted and arranged is a sealing end side,
While the outer peripheral surface of the sealed portion 5a of the glass bulb 5 is heated by the burner 7, a pair of pinchers 8a whose opposite end surfaces are processed into a substantially semicircular shape as shown in a sectional view and a plan view in FIG. 1 (c), 8b is pressed to reduce the diameter of the sealed portion 5a into an almost elliptical shape. In the step of heating the outer peripheral surface of the sealed portion 1a of the glass bulb 1 to reduce its diameter, the glass bulb 5 and the burner 7 are relatively rotated to heat the sealed portion 5a substantially uniformly. In addition, the degree of diameter reduction at this time is the space where the elliptical (oval) bead crow 6a of the mount 6 is locked to the reduced inner diameter, and the sealing end side of the glass bulb 5 can be exhausted. Is about to remain.

Next, the glass bulb 5 in which the sealed portion 5a has a reduced diameter is inverted, and as shown in a sectional view in FIG. 1 (d),
In a state where the oval bead glass 6a of the mount 6 is locked (contacted) with the oval-reduced inner wall portion of the sealed portion 5a,
While exhausting, the burner (not shown) heats the outer peripheral portion, while not shown, the pair of pinchers 8a, 8b
Is pressed against the outer peripheral surface of the elliptical sealed portion 5a to apply pressure, and the sealed portion 5a and the bead glass 6a are welded and hermetically sealed. At this time, if necessary, a part of the opening end side including the sealed portion 5a may be crushed and sealed. After that, the open ends of the glass bulb 5 and the lead wires 6b, 6 of the mount 6
By cutting b'to a required length and shaping it, a small light bulb as shown in cross section in FIG. 1 (e) is obtained.

Regarding the small light bulb manufactured as described above,
A visual inspection revealed that no filament 6c contacted the inner wall surface of the glass bulb 5,
No fear of blackening or shortening of life was observed. That is, since the mount 6 is sealed by the substantially oval-shaped bead glass 6a and the reduced diameter portion being locked / contacted with each other, the position is accurately determined, and the dispersion of the positioning is eliminated. Positioning accuracy of 6c is secured well,
It was confirmed that the occurrence of defects due to the positioning accuracy was completely eliminated.

In the manufacture of the small-sized light bulb, the mount 6 has a structure in which the elliptical bead glass 6a is hermetically inserted together with the lead wires 6b and 6b '.
The pair of pinchers 8a and 8b is formed into an elliptical sealed portion 5a.
After pressurizing and pressing the outer peripheral surface of the glass to weld and hermetically seal the sealed portion 5a and the bead glass 6a, the inside of the sealed portion of the mount 6 is evacuated and sealed, and then the opening end side of the glass bulb 5 and Even if a means for cutting and shaping the lead wires 6b, 6b 'of the mount 6 to a required length was adopted, it was possible to obtain a small bulb of high quality with high yield and high reliability.

The present invention is not limited to the above embodiments, but various modifications can be made without departing from the spirit of the invention.

[0020]

According to the method of manufacturing a small light bulb according to the present invention, the glass bulb corresponding to the sealed portion is changed by changing or setting the sealed portion of the small light bulb from a circular shape to an elliptical shape or an oval shape. Since the precision of the locking and contacting of the reduced portion and the bead glass can be ensured easily and easily, it is possible to provide a compact high-luminance and long-life compact bulb with stable quality and high yield. Here, the ability to easily and stably provide high-quality compact light bulbs with high yield is a means to bring great advantages to the provision of mass-produced and reliable instrument display light sources, etc. while requiring low cost. I can say.

[Brief description of the drawings]

1 (a) to 1 (e) are schematic views showing an embodiment example in the order of manufacturing steps in a method for manufacturing a small light bulb according to the present invention.

2 (a) to 2 (e) are schematic views each showing an embodiment example in the order of manufacturing steps in the conventional method for manufacturing a small-sized light bulb.

[Explanation of symbols]

 1,5 ...... Cylindrical glass bulb 1a, 5a ...... Encapsulated part (reduced diameter part) of glass bulb 2, 6 ...... Mount 2a ...... Disc bead glass 2d, 2b ', 6d, 6b ′ …… Lead wire (introduction wire) 2c, 6c …… Filament 3, 7 …… Burner 4 …… Roller 5a …… Glass bulb sealed part (elliptical reduced diameter part) 6a …… Oval plate bead Glass 8 ... Pincher

Claims (2)

[Claims] 1. A mount formed by mounting a filament on one end side of a pair of lead wires that are hermetically inserted through a substantially elliptical bead glass, and a cylindrical glass bulb whose one end is sealed, said filament being mounted on said mount. And a step of inserting and arranging the bead glass of the mount that is inserted and arranging as a sealing end side, and heating and pressurizing the outer peripheral surface of the sealed portion of the glass bulb to substantially reduce the diameter of the sealed portion. The step of reducing the diameter to an elliptical shape, the bead glass of the mount being positioned and locked to the reduced diameter sealed portion of the glass bulb, and the bead glass and the sealed portion being heated and welded in an exhausted state. Sealing /
A method of manufacturing a small-sized light bulb, comprising: 2. A mount formed by mounting a filament on one end side of a pair of lead wires that are hermetically inserted through an almost elliptical beet glass, and the filament is mounted on a cylindrical glass bulb whose one end is sealed. And inserting and placing the bead glass of the mount that has been inserted and placed as the sealing end side, and heating the outer peripheral surface of the sealed portion of the glass bulb to make the diameter of the sealed portion substantially elliptical. The step of shrinking the bead glass and the sealed part together by heating and welding in a state where the bead glass of the mount is positioned and locked to the reduced sealed part of the glass bulb. And a step of sealing after evacuating the inside of the filament sealing region of the mount, and manufacturing the small light bulb.