JPS5927431A - Apparatus for sealing luminous tube of discharge lamp - Google Patents

Abstract

PURPOSE:To prevent fluctuation of distance between electrodes and shape of end portion and to improve reliability by providing electrode holders opposed vertically, luminous tube holder provided on the circumference of lower part thereof and inactive gas introducing tube and by making it possible to move vertically the luminous tube holder. CONSTITUTION:A pair of electrode holders 4 for supporting and fixing electrodes 2 are arranged opposingly at the open end portion of tube body 1 of luminous tube, and fixed while keeping the distance between electrodes 2 constant. A clearance A is provided at the external side of lower holder 4, the luminous tube holder 6 which can move vertically is provided and the internal diameter B which is a holder of this holder 6 is larger than the external diameter D of lower end of tube body 1. The holding surface formed as the stepped portion is provided in the area deeper than C from the upper end of the luminous tube holder 6, the tube body 1 is inserted in such luminous tube holder 6 and is held with the lower end stopped and retained by the supporting surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that electrodes are sealed (11,
This invention relates to a sealing device for arc tubes.

FIG. 1 is a partially enlarged view showing a conventional sealing device for sealing an electrode to an end of an arc tube of a high-pressure metal vapor discharge lamp such as an unpressurized mercury rung. In this figure, (1) is a cylindrical arc tube body, and (3) is a chip tube for introducing inert gas attached to the center of this tube body (1).

(2) μ tube body (end J of 11: 9 electrode to be inserted and sealed).

(4) is a holder that is arranged opposite to one open end of the tube body for the arc tube and supports and fixes the electrode (2); A sealing cap (61U) is attached to the tube body (11'i), and a sealing cap (61U) is attached to the tube body (11'i).
Reference numeral 7) denotes a rare gas inflow pipe that is attached to the open end of the tip pipe (3) and allows the rare gas to flow into the pipe body (1).

In the structure thus constructed, a method of sealing the pole (2) to both ends of the entire tube body (1) will be described.

First, the upper end of the tube body (1) is sealed with a sealing cap (5).

The entire central part of the tube (11) is held and fixed by the arc tube holder (6).Then, the electrode (2) is inserted into the lower end of the tube (1), and in this state. Inserted electrode (2)
(2) That is, the outer wall of the end of the tube fil on the lower end side is heated to a high temperature with a gas burner, and the end is sealed and molded.

Next, remove the sealing cap (5) from the entire arc tube body (1).

Turn it upside down and bring the removed end toward the holding stand (4), fully insert the electrode (2), and seal the other end of the arc tube body (1) in the same way as above. This process seals the electrodes at both ends.

However, in the conventional arc tube sealing device as described above, the central part of the arc tube body (1) is attached to the arc tube holder (6).
Since the electrodes (2) are sealed on one side at a time, the arc tube body (1) may move up and down, or the tube body (
The center of electrode (2) often shifts from the center of electrode (2), resulting in variations in the distance between the electrodes and the shape of the sealed end, and the electrode cannot be sealed to the center of the arc tube body, resulting in lower lamp voltage. There are drawbacks such as variations and misalignment of the optical center axis.

This invention was made to eliminate the above-mentioned drawbacks, and includes a vertically movable arc tube holder, a lower electrode holder provided inside the arc tube holder, and an upper part of the lower electrode holder. and an upper electrode holder provided opposite to the upper electrode holder.

Hold the lower part of the arc tube body with an arc tube holder and seal the upper part. 9. Next, seal the sealed side, that is, the upper part 'f: Hold the lower part of the arc tube body with an electrode lead wire. By sealing, it is possible to completely prevent variations in the distance between the electrodes and the shape of the end, and a reliable arc tube for a discharge lamp can be obtained.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. In these figures, l4)(4t is a pair of electrode holders for supporting and fixing the electrodes (21(21'fr), respectively, and are arranged opposite to the open ends of the arc tube body (1), respectively. The electrodes (21 (21) are fixed so as to maintain a constant distance between them. A vertically movable light emitting device is provided with a gap Ai of 01-0,8711 m outside the lower electrode holder (4). There is a tube holder (6), and the inner diameter B of this arc tube holder (6), which is the holding part, is 0.2 I from the diameter of the lower end row of the arc tube body (1).
Im, -0,8z path is enlarged. In addition, there is a stepped holding surface at a location where the depth O from the upper end of the arc tube holder (6) is 5 degrees or more, and the 9 arc tube body (1) is inserted into this arc tube holder (6). The lower end thereof is held by a holding surface. The upper end of the lower electrode holder (4) is.

The distance from the holding surface of the arc tube holder (6) is 0.5 w+
that's all.

The outer diameter d of the lower electrode holder (4) is arranged below.
is made narrower by 15111 mm or more than the inner diameter of the arc tube body (1).

In addition, the inert gas introduction tube (7) is introduced into the inert gas arc tube tube (1) from the chip tube (3) provided in the center of the arc tube tube body (1). This is to replace the gas inside.

With the device configured as above, the pole (21121
A method of sealing the arc tube to both ends of the arc tube body (11) will be explained.

First, attach each electrode holder (41) to the electrode (21 (211).
41, insert this electrode +21 +21 into both ends of the arc tube body (1) with a predetermined distance between the electrodes, and attach the lower end of the arc tube body (1) to the arc tube holder (
6) to hold it.

In this state, inert gas is introduced into the arc tube body <11 from the inert gas introduction pipe (7) through the chip tube (3) to replace the air inside with inert scum. .

Thereafter, the upper end of the arc tube body (1) is heated and melted from the outer wall using a gas burner or the like, press-molded using pinchers (not shown), and the electrode (2) is sealed to the upper end. Thereafter, the arc tube holder (6) which is sealed to the upper end and supports the arc tube body (11) by the upper electrode holder (4) via the fct pole (2) and holds its lower end. After moving it downward, the lower end of the arc tube body (11) is heated and melted from the outer wall with a gas burner and pinched (
(not shown) to seal the electrode (2) and complete the sealing of the two arc tubes.

Now, in the device as described above, if the gap between the arc tube holder (6) and the lower electrode holder (4) is less than 0.111 ml, it will be difficult to move the arc tube holder (6). (18
If the value is 1111 or more, the 9 gap is large, so the tube body for the arc tube (
1), the arc tube holder (6) is tilted, and the center of the electrode (21 (2) and the center of the arc tube tube body (11) do not match. This gap is defined as cLt, -0,11 cage. By doing so, the center of the electrode (21+21) and the arc tube body (
The centers of the arc tube holders (6) are aligned, and the movement of the arc tube holder (6) becomes easy.

Also. The inner diameter B of the holding part of the arc tube holder (6) is 0.2H or less from the outer diameter of the lower end of the arc tube body (11). Cracks, chips, etc. occur at the lower end of the tube body (1), making the arc tube tube body (1) defective.If it is 0.8 WlI or more, the center of the arc tube body (1) and the electrode +21 (2+ f2+ is misaligned with the center of the electrode +2)
) and become defective. Luminous tube holder (
6) The inner diameter of the holding part Bi should be larger than the outer diameter of the lower end of the arc tube tube (1) within the range of 0.21 m - (18 m + 1). This eliminates defects caused by misalignment of the center of the electrode (2) (21) and the center of the arc tube body (11), and by the electrode (2) coming too close to the arc tube body (11).

Furthermore, the arc tube holder (6) that holds the entire arc tube body (1)
) If the depth C from the upper end of the holding surface to the holding surface is 5u or less, the holding effect of the tube body for arc tube 2 (11) will be lost and the tube body (1) cannot be held stably. OK
By setting it to 5 i+m or more, a retention effect is produced.

Also, from the holding surface of the arc tube holder (6) to the electrode holder (4)
The gap E to the upper end, that is, the distance between the upper end of the electrode holder (4) and the lower end of the tube (1) is 0.5 fig or less.

When sealing the lower end, the lower end of the arc tube body (11) is heated and melted, but at that time the lower end of the arc tube body (1) hangs down, and the electrode holder f41 K is attached and sealed. This may make subsequent removal difficult or damage the electrode holder (4). , 5 or more, the above problem will not occur.

Furthermore, the outer diameter d of the electrode holder (4) is the arc tube body (
If it is equal to but greater than the lower end inner diameter 11) of 1),
In addition, it takes a long time to fully fill the inert gas from the chip tube (3) through the inert gas introduction tube (7) and replace the air in the arc tube body (1) with the inert gas.

When sealing the ends, the flame of the gas burner from the outside reflects off the top surface of the electrode holder (4) and oxidizes the electrode (2) inserted into the arc tube body (11). Outer diameter d of the holder (4) Inner diameter I of the entire arc tube body (11)
D') The above problem was solved by making it thinner than 0.5 arm.

As described above, the present invention includes an electrode holder that holds electrodes facing each other vertically, an arc tube holder that is provided on the outer periphery of the lower electrode holder that holds an arc tube body, and an inert gas introduction tube. By making the arc tube holder completely movable up and down.

In addition to preventing misalignment between the center axis of the arc tube body and the center axis of the electrode and cracking or chipping of the ends of the arc tube body, it also prevents electrode oxidation due to burner flame entering the arc tube body.
It is also possible to prevent variations in the shape of the end portions of the arc tubes.

Furthermore, the distance between the electrodes can be checked before electrode sealing.
In addition to being able to prevent variations in lamp voltage and scratches on the optical center axis, this also has the effect of greatly improving the yield when manufacturing arc tubes.

[Brief explanation of the drawing]

FIGS. 1 and 2 are partial front views showing the steps of manufacturing using a conventional arc tube sealing device, and FIGS. 3 and 4 show a process for manufacturing using an arc tube sealing device according to an embodiment of the present invention. FIG. 5 is a partial front view showing the process order, and FIG. 5 is a partial enlarged view showing the main parts further enlarged. The same symbols in the figures indicate the same or equivalent parts, (1) 1 arc tube body, (2) electrode, (3) chip tube, (4)
(5) is the sealing cap, (6m arc tube holding shell, (7) is the inert gas introduction tube. Representative: Makoto Kuzuno - Figure 1, Figure 3, Figure 4)

Claims (1)

[Claims] An upper electrode holder for holding an electrode sealed in a luminous tube body facing downward; an upper electrode holder is provided below the upper electrode holder at a spacing such that the tube body can be arranged in the axial direction; A lower electrode holder that has a cylindrical shape smaller than the inner diameter of the tube by a certain value or more and holds the center Vct pole of its end face upward; The inner circumferential wall becomes stepped at a position of the above distance, and the diameter of this inner circumferential wall is larger than the outer diameter of the tube within a predetermined range, and the inner circumferential wall holds the tube and slides in the vertical direction. 1. A sealing device for a discharge lamp arc tube, comprising a movable tube holder and an inert waste introduction tube attached to an open end of a chip tube provided in the tube.