JPH01173541A - Manufacture of glass tube for single-base small fluorescent lamp - Google Patents

Abstract

PURPOSE:To stabilize the light output characteristic by heating and softening the outside portion of the bent tube section of a U-shaped glass tube, recessing and deforming the center section of this softened portion, and forming a recess on the center section of the outside of the bent tube. CONSTITUTION:The outside portion (m) of the bent tube section 15b of a U-shaped glass tube 15 is heated and softened. The center of the outside portion (m) is pushed up and recessed to form a recess 20 at the center. In a U-shaped glass tube 14 thus molded, protruded tip sections 15c on both sides of the recess 20 formed at the center of the outside of the bent tube 15b become the coldest sections apart from a discharge passage formed in the glass tube 14. A single- base small fluorescent lamp using one or multiple U-shaped glass tubes 14 can easily obtain the coldest points. The light output characteristic can be thereby stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a glass tube for a small single-cap fluorescent lamp in which a meandering discharge path is formed using a glass tube.

Traditionally, compact single-cap fluorescent lamps are made by forming a meandering discharge path in a double-0 shape using a glass tube. Due to their low power consumption and long lifespan, they are becoming popular as a new light source to replace incandescent light bulbs. A common single-cap small fluorescent lamp is one in which four straight glass tubes are connected to form a double U-shaped discharge path, examples of which are shown in Figures 11 to 13. .

The single-cap compact fluorescent lamp (1) shown in the figure has a cap (6) fixed to the end of the same side of four straight glass tubes (2) to (5) connected in a double-0 shape. It is. adjacent 2
Book glass tubes (2) (3) and the remaining two glass tubes (4)
(5) has a tubular connection (7) at the tip opposite to the base (6).
(8), and the two adjacent glass tubes (3) and (4) have a tubular connection part (9) at the end on the base (6) side.
) to form a double-0-shaped discharge path, and this discharge path is filled with mercury and a rare gas. Connection part (7) that connects the tip sides of each glass tube (2) to (5)
(8) is provided at a location approximately 1 Ofl away from the tips of the glass tubes (2) to (5) for reasons described later.

The fluorescent lamp (1) has a maximum light output at the mercury vapor pressure when the temperature at the coldest point of the glass tube is about 40° C., like a general mercury-filled fluorescent lamp. Therefore, the connection parts (7) and (8) are separated from the tips of each glass tube (2) to (5), and the glass tube (2) is separated from the discharge path passing through the connection parts (7) and (8).
By keeping the tips of (5) apart, the coldest point that stabilizes the mercury vapor pressure and stabilizes the light output can be found at any of these tips.

The double U-shaped glass tube in such a fluorescent lamp (1) is manufactured as follows. First, the 14th
A straight fluorescent glass tube with a sealed tip as shown in the figure (
10) and insert 1() from the tip of this glass tube (10).
Immediately after, as shown in Fig. 15, a high pressure gas such as N2 gas is blown into the glass tube (10) to soften it sufficiently by locally heating a predetermined point about 100 ha apart with a burner flame (11). A bulging and torn hole (12) is formed in the locally heated portion of (10). A glass tube like this (
10), and insert two glass tubes (10) (10') into each hole (10') as shown in Figure 16.
2) (12”) butt the peripheries to face each other in equilibrium,
The two glass tubes (10) (10') are connected and fixed together at the connection part (13) formed by reheating the peripheries of both holes (12) (12°) and fusing them into a tubular shape. . Two approximately U-shaped glass tubes obtained in this manner are connected in a double 0 shape to obtain a double U-shaped glass tube.

As shown above, in a single-cap compact fluorescent lamp manufactured by connecting four straight glass tubes in a double-0 shape, the tip of the glass tube is farthest from the discharge path, causing the This creates a cold spot and stabilizes the light output characteristics, but there was a difficulty in the manufacturing process of double U-shaped glass tubes, especially approximately U-shaped glass tubes. As explained in Fig. 14 to Fig. 16, the manufacturing process for connecting the glass tubes involves drilling holes by local heating of the glass tubes, fusing by local reheating of the two glass tubes, and fusing the two glass tubes by local reheating. Workability was poor due to the large number of technically difficult tasks such as removing residual distortion from parts, which made it difficult to mass-produce small single-cap fluorescent lamps.

The present invention has been made in view of the above-mentioned problems in manufacturing a substantially U-shaped glass tube for a single-cap compact fluorescent lamp.
The present invention is characterized in that the outer part of the curved tube part of the U-shaped glass tube is heated to soften it, and then the center part of the softened part is recessed and deformed to form a recessed part in the outer center part of the curved tube part.

When a recessed part is formed in the center of the outside of the curved tube part of a countersunk U-shaped glass tube, the ends on both sides of the concave part of the curved tube part become the coldest point parts away from the discharge path, and the single-capped small fluorescent Stabilizes lamp characteristics. In addition, the immersion deformation of the bent tube portion of the U-shaped glass tube after partial heating can be easily performed by pressing the entire shape, etc., and the workability of the glass tube manufacturing process can be improved.

1 to 10 show specific embodiments of the method of the present invention.
This will be explained with reference to the figures. Note that FIGS. 1 to 7 are for explaining the first embodiment, and FIGS. 8 to 10 are for explaining the second embodiment.

In the first embodiment a, the result is approximately U as shown in FIG.
This glass tube (14) is produced in the shape of a
14) is manufactured from the U-shaped glass tube (15) shown in FIG. 1 as follows.

The U-shaped glass tube (15) is made by heating the center of a straight glass tube to soften it, then bending it into a 0-shape from the center and molding it with a mold, and it has two parallel straight tubes. (15a) (
15a) and a molded bent pipe part (15b). For this U-shaped glass tube (15), as shown in FIG.
) is heated with a burner flame (16) to soften it. Next, while the outer portion (m) of the bent tube portion is sufficiently softened, the bent tube portion (15b) is inserted into the molding hole (1 day) of the predetermined mold (17) as shown in FIG. Press into the molding hole (1) of the mold (17).
As shown in Figures 6 and 7, 8) is a hole shaped to fit the two straight pipe parts (15a) (15a) of the U-shaped glass tube (15), and protrudes about 10B from the center of the bottom. Projection (1
The curved tube part (15b) of the U-shaped glass tube (15) is fitted into the molded hole (18) in which the glass tube (15) is formed.
5) Raise the internal pressure by blowing N2 gas etc.
When the bent pipe part (15b) is pushed into the forming hole (18), the protrusion (19) of the forming hole (18) pushes up the center of the outer part (m) of the bent pipe part (15b) and dents the fourth part. As shown in the figure, a recess (20) is formed in the center of the outer portion (m) of the curved tube section (15b), and the curved tube section (15b) is molded into a substantially H shape. From this glass tube (15) to the mold (17)
When removed, a substantially U-shaped glass tube (14) shown in FIG. 5 is obtained.

The approximately U-shaped glass tube (14) molded in this way is
A recess (20) formed at the center of the outside of the curved pipe portion (15b)
The protruding tips (15C) (15c) on both sides of the glass tube (14) serve as the coldest point away from the discharge path formed in the glass tube (14). Therefore, the single-cap compact fluorescent lamp using one or more of these approximately U-shaped glass tubes (14) can easily obtain the coldest point and have stable characteristics.

Next, a second embodiment shown in FIGS. 8 to 10 will be described. In this case, first, as shown in FIG. 8, the outer part (m
) is locally heated with a burner flame (21) to sufficiently soften it. Next, this softened part is pinched and crushed from both sides with pliers (22) as shown by the chain lines in FIG. 10, and recesses ( 23) Mold (23). The crushed portion (24) between the two recesses (23) does not necessarily need to be left.

A substantially U-shaped glass tube (14
') are the tips of both sides of the recess (23) (23) (
15d) (15d) is the coldest point part away from the discharge path. In addition, the crushed portion (24) between the recesses (23) (23)
) reinforces the curved portion of the approximately U-shaped glass tube (14'), making handling convenient.

Since the present invention, the manufacturing process of heating and softening the outer part of the curved pipe part of a U-shaped glass tube to form a depressed and deformed recess in the center part has been used to prevent local holes. Lighting is technically easier than processing or fusing, requires fewer man-hours, and is superior in mass production. Further, in the glass tube manufactured according to the present invention, both sides of the concave portion can be used as the coldest point, making it possible to manufacture a high-quality single-cap compact fluorescent lamp with stable light output characteristics.

[Brief explanation of the drawing]

1 to 7 are for explaining the first embodiment of the present invention, and FIG. 1 is a front view of a U-shaped glass tube, and FIG.
The figure is a front view of the glass tube shown in FIG. 1 when heated, FIGS. 3 and 4 are partial front views of the glass tube shown in FIG. 2 when it is formed, and FIG. 5 is a perspective view of the formed glass tube. 6 is a front view including a partial cross section of the mold used in the molding shown in FIG. 3, and FIG. 7 is a sectional view taken along the line AA in FIG. 6. 8 to 10 are for explaining the second embodiment of the present invention, FIG. 8 is a front view of the U-shaped glass tube during heating, and FIG. 9 is a front view of the glass tube of FIG. 8. A front view after molding, and FIG. 10 is a sectional view taken along the line B--B in FIG. 9. FIG. 11 is a front view of a small single-cap fluorescent lamp with a glass tube manufactured by a conventional manufacturing method, and FIGS. 12 and 13 are a side view and a bottom view of the fluorescent lamp of FIG. 11. 14 to 16 are front views of glass tubes including partial cross sections at each step for explaining a conventional glass tube manufacturing method. (15) -U-shaped glass tube, (15b) -.-bent tube part, (m) -..~outer part, (20) (23).-recessed part. Fig. 1 Fig. 2 (fJ” Last Keijo A 11th pull)
(Shiro side sea e% - esE surface 1%lI) Fig. 6 Fig. 7 Fig. 8 Fig. fJ9 Fig. 1θ (s-a Korean #r consideration) Fig. 11 Fig. 12

Claims (1)

[Claims] A single-ended device characterized by heating and softening the outer part of the curved pipe part of the U-shaped glass tube, and then deforming the central part of the softened part to form a recessed part in the outer center part of the curved pipe part. A method for manufacturing glass tubes for small gold fluorescent lamps.