JPS60172134A - Forming of glass tube for exhaustion - Google Patents

Abstract

PURPOSE:To make it possible to form an accurate protrusion with a simple configuration by heating and softening all around a specified portion of a glass tube and then inserting a shaft into the glass tube through this heated portion and by applying a pressing force to the glass tube toward the middle part of it. CONSTITUTION:A specified position 64 at one end 62 of a glass tube 61 is heated and softened all around by a ring burner B. A stopper D is placed to touch on the other end 63 of the glass tube 61, and on the other hand an insertion part C1 of a shaft C (made of graphite and a combination of the insertion part C1 and a touching part C2) is inserted through the end 62 of the glass tube 61 until the touching part C2 touches on an end face 65 of the glass tube 61. The shaft C is pressed toward the middle part of the glass tube 61 to form a sword guard-shaped protrusion 66 at the specified position 64 where the glass tube 61 is heated and softened. Then the shaft C is taken out of the glass tube 61 and the stopper D is also removed; thus an exhaust tube 6 is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to a method of forming a glass tube used for evacuation of a fluorescent lamp or the like.

[Prior art]

The exhaust glass tube C (hereinafter referred to as exhaust tube) of a straight fluorescent lamp or the like generally uses a straight, hollow glass tube, and is often used by being directly sealed to a glass stem.

On the other hand, in recent years, apart from such fluorescent lamps, small-sized fluorescent lamps aimed at making the shape more compact have been proposed. FIG. 1 shows an example. In the figure, (
1) is the pulp, +21 is the bottom u3 of the pulp (1) (
13 is an end plate that airtightly closes the opening, (4) is a glass stem with an electrode (3) r sealed on the top and a single wire system protruding outward, and 16: an exhaust pipe. . These pulp tl+, stem (4), and exhaust pipe (61 are each valved with a glass frit (5) and are hermetically fixed to the end plate (21). (7) is covered with the inner surface of the pulp (1). Layered phosphor layers.

(1υ is the communication part of pulp (1) 0 The rung configured in this way has pulp il+ and end plate (
21, the stem (4), and the four lead wires (2) are closely arranged in a compact arrangement. In the case of extending C, this exhaust>g (6t is the lead wire 133
It becomes a hindrance when processing the electrodes (3) through the lamp or when electrically connecting the completed lamp.

For this reason, the exhaust pipe (6:) is provided separately from the stem (4) as described above.

Therefore, the applicant first proposed an exhaust pipe (6) for such a lamp.
) as 1. As shown in Fig. 2, we have proposed a flange-shaped protrusion (66) whose diameter is larger than the outer diameter of the glass tube (6) at a predetermined location on one end (62) side of the glass tube (6). If the exhaust pipe (6) of the exhaust pipe (6) is used, the protrusion (66) of the exhaust pipe (6) will not stick to the end plate (21) through the glass frit, as shown in Figure 2. It becomes a locking part with the end plate (2), and prevents the glass frit (51) from sagging downward.In addition, the exhaust pipe f6+ can be supported by the end plate (21) without special support from the outside. .

This makes it easier to apply and fix the glass frit (51). However, in this exhaust pipe (6).

The tip (62) side and the lower end (53) with the protrusion (66) as the boundary
) If the centering is insufficient with the end plate (21), it will become difficult to insert the exhaust pipe (61) into the end plate (21), paint the glass frit (51), or attach it to the exhaust machine (not shown). Further, unless the shape of the protruding portion (66) is formed with high precision, problems such as the glass frit (5) dangling downward may occur.

[Summary of the Invention] The present invention has been made based on the above-mentioned background, and it is possible to provide a flange-like protrusion whose diameter is larger than the outer diameter of the exhaust pipe at a predetermined location in a simple manner and with high precision. The purpose is to provide a molding method that can be used.

[Embodiments of the invention]

Next, an embodiment of the present invention will be explained in the order of steps with reference to FIGS. 3 to 6.

1. First, the outer diameter is 5mm, the inner diameter is 3.4+mm, and the total length is 10mm.
A third glass tube made of lead glass (61) cut into 3 mm
As shown in the figure, the glass tube (61) is placed on the glass tube (61) from one end (62) of approximately 6WrIR+t (64) to the entire circumference with a ring burner (B) to soften it.

2. Next, as shown in Figure 4, as soon as the ring burner (B) is heated and softened, the ring burner (B) is released and the glass tube (61
) is brought into contact with the other end (63) of the stopper CD);

The insertion part (C1) of the core shaft (C), in which the insertion part (C1) and the contact part (C2) are integrated, is inserted from the one end (62) side of the glass tube (61) so that the contact part (C2) Insert the glass tube (61) until it touches the U end surface (65). Furthermore, this 8
The insertion part (C1) of the barrel (0) has an outer diameter of 3.2 and a total throat length of 10.
ffl++.

The contact portion (C2) is made of graphite material with an outer diameter of 10 m.

3. Next, in this state, adjust the core salary (C) as shown in Figure 5.
) in the direction of the center of the glass tube (61) by a distance of 2IIOI+, and with this pressing force, the glass tube (
A flange-shaped protrusion (66) with an outer diameter of 5 mm is formed at a predetermined position (64) that has been heated and softened in 61).

4. Then, remove the core (C) from the glass tube (61),
I also released the stopper and completed the exhaust pipe (61).

That is, in such a method of forming the exhaust pipe (6), the expanded diameter part (66) is formed by inserting the insertion part (C1) of the core diameter (0) into the glass tube (61), Since the molding is performed using only the suppressing force, a complicated molding device is not required and the molding can be easily performed.

In addition, the matchmaker part (cl) of 8 salary (C) is a glass tube (61)
The glass tube (61) is inserted through the heated softening part (64) to the center of the glass tube (61), and then a pressing force is applied to the tube (c) to form the enlarged diameter part (66). , heating, forming the enlarged diameter part [66] with the softened part (64) as the border (6?).
) 11111 and the other end (6'+) side, it is prevented by the insertion part (C1), and at most the misalignment is caused by the difference between the inner diameter of the glass tube (61 and the outer diameter of the insertion part (cl)). As a result, the contact portion (C2) and the end surface (64) of the glass tube (61) do not abut evenly over the entire circumference, and the pressing force toward the center of the glass tube (61) is uneven. Even in such a case, there is no problem of misalignment.Therefore, there is no need to require much precision of the end surface (64) when cutting the glass tube (61).

Furthermore, since there is almost no void inside the glass tube (61) due to the insertion part (C1) of 8 pieces (0), when a pressing force of a certain distance is applied, the glass wall of the heated and softened part (64) The protruding portion (66) is reliably protruded in the diametrical direction without accumulating on the inside, and a stable protruding portion (66) can be obtained.

In addition to the above-mentioned actual ttvpIl, as shown in FIG. ) may be rotated. In this case, even one burner (B) can uniformly heat and soften the predetermined position (64) over the entire circumference. Further, as shown in Fig. 8, the insertion part (C1) of the core (C) is inserted into the glass W (61), and at the same time the glass tube (61) is heated and softened, and the core frame (C) is inserted into the glass tube. (61) may be pressed toward the center.

On the other hand, such an exhaust pipe (61 tip 4 (62) (63)
In many cases, simple glazing that does not cause deformation is performed, but such glazing processing is performed after the exhaust pipe (6) is completed, or a predetermined position (64) of the glass tube (61) is heated and softened. The effect of the present invention is not diminished in any way by performing the heating and softening process at various times or by performing the heating process in advance before the softening process.

〔Effect of the invention〕

As described in detail above, this invention heats and softens a predetermined part of a supported glass tube over its entire circumference, inserts a core frame that passes through the heated part into the glass tube, and By applying a pressing force in between, a flange-shaped protrusion is formed at the heated and softened portion, so the protrusion can be manufactured in a simple manner and with high precision. Therefore, the production yield of rungs using such an exhaust pipe can be improved.

[Brief explanation of drawings]

FIG. 1 is a partially sectional perspective view showing an example of a small fluorescent lamp;
FIG. 2 is a partially enlarged sectional view of an exhaust pipe previously proposed by the present applicant, FIGS. 3 to 6 are process diagrams illustrating a part 1M example of the present invention, and FIGS. 1 and 8 are respectively FIG. 6 is a partial process diagram showing another embodiment of the present invention. In these figures, (61 is the exhaust pipe 1, (61) is the glass tube, (64) is the heated, softened part 1, (66) is the protrusion, (C) is the core frame, and (01) is the insertion part of the core frame. In addition, the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa 1vA Figure 2 Pa Figure 3 Figure 7 Figure 8

Claims (1)

[Scope of Claims] (1) A predetermined part of the supported glass tube is heated and softened over the entire circumference, and a core rod passing through the heated part is inserted into the glass tube, and then the glass tube is heated toward the center of the glass tube. A method for forming an exhaust glass tube, characterized in that a flange-like protrusion is formed at a heated and softened portion by applying a pressing force to the glass tube. (2) The glass tube is inserted into the glass tube. The exhaust device according to claim 1, characterized in that a single-core rod having an insertion portion and a contact portion that is integrally formed with the insertion portion and comes into contact with the end surface of the glass tube is inserted into the glass tube. Method for forming a glass tube. (3) The method for forming an exhaust glass tube according to claim 1, characterized in that the glass tube is rotated during heating and softening.