JPS62154431A - Sealing method for bend type fluorescent lamp - Google Patents

Abstract

PURPOSE:To make the inner surface of a sealing scheduled part so as to be formed on a continuous smooth surface, by forming the sealing scheduled part in advance and, after removing a phosphor film, letting electrodes ajoin each opening part at both ends of a discharge passage, inserting them into the sealing scheduled part, then performing a pinch seal. CONSTITUTION:A glass bulb 6 being molded by metal molds 30 and 30 is provided with an almost U-shaped discharge passage 7, installing a continuous wall 8 between walls of adjacent discharge passages 7, and one end is interconnected to both opening ends of these discharge passages 7 in common and a large diametral tubular sealing scheduled part 32 where the other end is opened is formed. A phosphor applying liquid is poured in the inside of the bulb 6, applying a fluorescent material to the whole inner surface, then a phosphor film being applied to an inner circumferential wall surface of the sealing scheduled part 32 is removed. Electrode mounts 12 and 12 are inserted into both ends of these discharge passages 7 through the sealing scheduled part 32, and they are heated and softened, then the sealing scheduled part 32 is crushed by pinch metal molds 18 and 18. Thus, these electrode mounts 12 and 12 are sealed up by a pinch seal part 33, so that an inner surface of this sealing scheduled part 32 is smooth enough, thus no concave part is produced there.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for sealing electrodes of a bent fluorescent lamp having a U-shaped or meandering discharge path.

(Prior art) As a method for manufacturing a fluorescent lamp, the present applicant has developed
The method disclosed in Japanese Patent Publication No. -95828 is proposed.

The manufacturing method disclosed in the above publication involves heating and softening a glass tube with a relatively large diameter, and molding the softened glass tube into a pair of molded surfaces that correspond to a curved discharge path, such as a U-shape. A bent bulb with the curved discharge path is molded by pressing with a mold, and with this method, a bent bulb with little change in bulb wall thickness can be easily obtained. , which has the advantage of being mass-producible.

The conventional manufacturing method disclosed in the above publication will be explained based on the drawings shown in FIGS. 12 to 20, and its problems will be described.

In the figure, 1 is a large-diameter glass tube that is used as a material to be formed into a bent glass bulb, and the entire large-diameter glass tube 1 is uniformly heated by a burner 2 shown in FIG. Ru.

When the large diameter glass tube 1 is in a softened state, a pair of molds 3, 3
Press by. The molds 3, 3 are symmetrical to each other, and as shown in FIG. 13, each has, for example, a substantially U-shaped molding surface 4 and a partition wall 5 in the center.

The softened large-diameter glass tube 1 is pressed by a pair of molds 3, 3, and as shown in FIG.
, 3 are brought into contact with each other, and in this state, pressurized air is sent from the end of the large-diameter glass tube 1, and the glass tube 1 is blow-molded, thereby obtaining the glass bulb 6 shown in FIG. 15.

The glass bulb 6 shown in FIG. 16 has a U-shaped discharge path 7, and the partition wall 5
It has a continuous wall 8 formed by. Further, both ends of the discharge path 7 are open, and the openings 9 are formed adjacent to each other and lined up in the same direction.

After the glass bulb 6 is annealed to remove thermal distortion generated during molding, the continuous walls 8 located near the openings 9.9 at both ends are removed.

That is, when the flame of the burner 10 is directed toward the continuous wall 18 at the position to be removed, the continuous wall 8 at this position is heated and softened, and the softened portion is blown out under the pressure of the jet gas of the burner 10. Therefore, t, the continuous wall 8 has the first
As shown in Figure 6, the cut section 11 (discontinuous section - slit)
is formed.

The reason why the cutout portion 11 is formed in the continuous wall 8 is as follows. That is, when sealing, for example, the electrode mount 12.12 shown in FIG. 17 to the opening 9.9, the mount 12.12 is sealed by heating and softening the peripheral wall of the opening 9.9 and pinch-sealing it. Although it is meant to seal,
When heating and softening the peripheral walls of the openings 8139 and 9, if the continuous wall 8 remains here, it will not be possible to heat evenly around the entire circumference, resulting in uneven temperature distribution and partial thermal distortion. occurs and cracks are likely to occur. On the other hand, when the cutout portion 11 is provided, uniform heating can be performed and the generation of cracks can be prevented. In addition, the electrode mount 12゜1
2 is composed of a lead wire 13, 13, a filament 14, and a bead glass 15, and an exhaust pipe 16 is joined to the bead glass 15 of at least one electrode mount 12.

After providing the resection portion 11, a first
As shown in Figure 6, pour the phosphor coating liquid to coat the entire inner surface with the phosphor. After forming the phosphor coating 17 on the entire inner surface of the bulb 6, the phosphor coating applied to the inner peripheral wall surface of the opening 9.9, which is to be pinch-sealed, is removed.

Thereafter, the electrode mount 12°12 is inserted into the openings 9, 9, the opening 9.9 is heated and softened with a burner (not shown), and the opening 9.9 is formed using a pinch mold 18°18 shown in FIG. Electrode mount by crushing 12.1
Seal 2.

In this way, 1! A fluorescent lamp is produced in which the pole mount 12.12 is sealed by a pinch seal 19.

(Problems to be Solved by the Invention) In such a manufacturing method, a large diameter glass tube 1 is pressed by a pair of molds 3゜3 to form a substantially U-shaped discharge path 7 and an adjacent one. When making a glass bulb 6 having a continuous wall 8 between the walls of the discharge path 7, as shown in FIG. 20 (A>), the continuous wall 8 is formed by being pressed in the direction of the arrow. A recess 20.20 is formed on the inner surface of the discharge path 7 corresponding to the continuous wall 8.If a fluorescent body liquid is applied to the inner surface of such a discharge path 7 to form a coating [17],
A phosphor coating 17 is also formed on the inner surface of the recess 20.20.

However, when pinch sealing is performed, the presence of impurities such as a phosphor coating on this sealing surface may cause leakage, so a coating is applied to the inner circumferential wall surface of the opening 9.9 where the pinch sealing is to be performed. The phosphor coating is to be removed.

However, according to the above manufacturing method, the concave portion 20.20 is also formed in the area where the vinyl seal is planned, so the phosphor film formed on the inner surface of the concave portion 20.20 is not completely removed even during the removal operation. , as shown in FIG. 20(C), the remaining amount is 21.21.

Such residual phosphor film 21.2'1 remains in the seal portion 19 when pinch sealing is performed, as shown in FIG. 20(D), causing problems such as leaks and cracks.

The present invention has the advantage that no phosphor film remains on the pinch seal portion,
It is an object of the present invention to provide a method for sealing a bent fluorescent lamp that prevents leaks and cracks.

[Means for solving problems]

When molding a bulb by pressing with a pair of molds, the present invention provides a cylindrical sealing portion having a common and single opening communicating with both openings of the discharge path. After forming and applying a phosphor film, and removing the phosphor film from the area to be sealed, apply the 1/i electrodes to the area to be sealed, with each of the 1/i electrodes facing the openings at both ends of the discharge path. It is characterized by inserting the seal and pinch-sealing the portion to be sealed.

[Effect]

According to the method of the present invention, since the inner surface of the portion to be sealed is formed into a continuous and smooth surface, no phosphor film remains on this inner surface, and leaks and cracks are prevented from occurring.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in FIGS. 1 to 11.

In the embodiment shown in FIGS. 1 to 11, the first
Members similar to those in the conventional system shown in FIGS. 2 to 20 are designated by the same reference numerals and their explanations will be omitted.

In this example, each step is the same as the conventional one, but one pair (7
) Mold 30.30:4;t, formed [i4,! :, a partition 8vps, and a molding surface 31 having a semi-elliptical or semi-elliptical shape, for example, is formed on the open end side. As shown in FIG. 4, the glass bulb 6 formed by such a mold 30, 30 has a U-shaped discharge path 7, and a continuous wall 8 between adjacent walls of the discharge path 7. At the same time, a large-diameter cylindrical sealing portion 32 is formed, one end of which communicates with both open ends of the discharge path 7, and the other end of which is open. As shown in FIG. 5, this sealing portion 32 has an oval or elliptical cross section. In addition, the portion to be sealed 3
The length of 2 is 2 to 101. Appropriately it is about 100%.

Such a glass bulb 6 has a sixth glass bulb inside the bulb 6.
Pour the phosphor coating liquid as shown in the figure to coat the entire inner surface with the phosphor. After forming the phosphor coating 17 on the entire inner surface of the bulb 6, the phosphor coating applied to the inner circumferential wall surface of the portion to be sealed 32 is removed. In other words, the phosphor coating 17 covers the discharge path 7 as shown in FIG.
It is formed only on the inner surface of

Thereafter, as shown in FIG. 9, the electrode mounts 12° 12 are inserted into both ends of the discharge path 7 through the sealed portion 32, and the sealed portion 32 is heated and softened with a burner (not shown). The portion to be sealed 32 is crushed using a pinch mold 18, 18 shown in the figure.

In this way, the electrode mount 12.12 is sealed by the pinch seal 33 shown in FIGS. 8 and 11.

According to the method of this embodiment, the pair of molds 30, 3
When the large-diameter glass tube 1 is press-molded at 0, a large-diameter oval or elliptical cylindrical sealing portion 32 communicating with both open ends of the tI1M path 7 is formed. The inner surface of 32 is smooth, that is, no recesses 20 as in the conventional case occur.

Therefore, when the phosphor coating liquid is poured into the inner surface of the bulb 6 and the phosphor coating 17 is formed, the portion 3 to be sealed is
The phosphor coating formed on the inner surface of the phosphor film 2 can be completely and reliably removed at the same time.

Therefore, when the scheduled sealing portion 32 is crushed, no phosphor remains, so that leaks and cracks do not occur. .

Further, according to the above-mentioned pinch sealing method, the portion 32 to be sealed that is formed continuously in the discharge path 7 is heated and softened, so that uniform heating can be performed over the entire circumference. For this reason,
Unlike the conventional method, it is not necessarily necessary to form a special cutout part 13 in the continuous wall 8, and when the cutout part 13 is not formed, this step is omitted, so that work efficiency is improved.

In addition, as shown in FIG. 8, in the completed bulb 6, the adjacent discharge paths 7 and 7 are mechanically connected at one end by a substantially U-shaped bent part, and the other end is mechanically connected by a pinch seal part 33. The mechanical strength is strengthened because of the physical connection. From this, the continuous wall 8 is not necessarily required, and the continuous wall 8 can be omitted.

〔Effect of the invention〕

As explained above, according to the present invention, when molding a bulb by pressing with a pair of molds, a cylindrical shape having a common and single opening communicating with both openings of the discharge path is formed at both end openings of the discharge path. A portion to be sealed is formed, a phosphor coating is applied, and the phosphor coating is removed from the portion to be sealed. Since it is inserted into the part to be sealed and the part to be sealed is pinch-sealed, the inner surface of the part to be sealed is formed into a continuous and smooth surface, so that this part can be easily removed during the removal process of the phosphor coating. A phosphor coating is prevented from forming on the inner surface.

[Brief explanation of drawings]

Figures 1 to 11 show an embodiment of the present invention, and are explanatory diagrams of the manufacturing method, respectively, and Figures 12 to 20 (A
>(B), (C), and (D) are explanatory diagrams showing conventional methods. 1... Large diameter glass tube, 2... Burner, 30...
Mold, 4... Molding surface, 5... Partition wall, 6... Glass bulb, 7... Discharge path, 8... Continuous wall, 12...
...electrode mount, 17...phosphor coating, 32...
- Part to be sealed, 33...pinch seal part. Applicant's representative Patent attorney Takehiko Suzue Figure 5 Figure 6 Figure 7 Figure 8 Figure 13 Figure 15 Figure 14 Figure 16 Figure 17 q and Figure 8 Figure 19 (A) Figure 20

Claims (2)

[Claims] (1) By heating and softening a large-diameter straight glass tube and pressing the softened glass tube with a pair of molds having molding surfaces corresponding to the curved discharge path, the openings at both ends are aligned with each other. A bulb having a curved discharge path was molded, a phosphor coating was applied to the inner surface of the curved discharge path, and electrodes were inserted into the openings at both ends of the curved discharge path for pinch sealing. In the method for sealing a bent fluorescent lamp, when the bulb is molded, a cylindrical sealing portion having a common and single opening communicating with the openings at both ends of the discharge path is formed; A bent type characterized in that after removing the phosphor coating of the intended part, the electrodes are inserted into the intended part to be sealed so as to face the openings at both ends of the discharge path, and the part to be sealed is pinch-sealed. How to seal a fluorescent lamp. (2) The portion to be sealed is formed in a flat shape having a long axis along a direction in which openings at both ends of the curved discharge path are juxtaposed. A method of sealing a bent fluorescent lamp.