JPS60243934A - Production of light emitting tube for miniature-type high-pressure metallic vapor discharge lamp - Google Patents

Abstract

PURPOSE:To obtain a light emitting tube having no electrical or optical variations, by a method in which the central portion of a tube stock is heat melted and formed into a U-shape in a mold, an exhaust tube is attached to the central portion of the tube stock and electrodes are sealed to both of the open ends. CONSTITUTION:A tube stock 1 is heat melted by flames, while rotated, such that the central portion thereof is bent. The tube 1 is placed in a mold 5a while supplied with inactive gas 3 with one of the open ends closed with a cap, so that it is formed into a U-shape. An exhaust tube 6 is welded to the part 1b where the tube is broken by the flow of air so as to communicate with the tube. An intermediate portion of the exhaust tube 6 is held by a holder 11 and a gas introducing tube 10 is attached to the exhaust tube 6. Electrodes 9 held by a holder 8 are inserted into the tube stock 1 from the open ends thereof and then the inactive gas 3 is introduced into the tube through the introducing tube 10 so as to substitute the atmosphere within the tube stock. The outer periphery of the tube stock 1 is heat melted by flames 4 and the electrodes 9 are sealed to the tube stock by a pincher head. Thus, a light emitting tube can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing an arc tube for a miniature high-pressure metal vapor discharge lamp.

[Prior art]

Conventionally, the method for manufacturing miniature arc tubes with an internal volume of Ice or less involves heating and melting the central part of a raw tube cut to a predetermined size, attaching it to a mold of a predetermined shape, and blowing it into shape. Completely mold. Thereafter, the central part of the raw pipe is heated and blown open by blowing inert gas, etc., and an exhaust pipe is connected to this part.

Insert a metal rod into the bottom opening of the base pipe to which the exhaust pipe is attached, and melt and seal the bottom opening while flowing inert gas.
Flip it 80 degrees and melt-seal the other end opening in the same way.

Incidentally, this type of arc tube has been manufactured by the steps shown in FIGS. 1 to 8. That is, according to the conventional manufacturing method, as shown in FIG. Activated gas is allowed to flow in. While rotating, the central part of the raw tube 1 is heated and melted by the flame 4.The raw tube 1 stops rotating, and as shown in FIG. Gas 3 flows in and pressurizes the inside of the tube 1 to form an bulge. Thereafter, a part of the bulging portion 1a of the raw tube 1 is heated and melted by a flame 4 as shown in FIG. 3, and an inert gas is flowed into the tube to blow out the melted portion as shown in FIG. Then, as shown in FIGS. 5 and 6, the exhaust pipe 6 is welded and communicated with the blown-out portion 1b while being melted by the flame 4. One end opening of the blank tube 1 formed as described above is closed with a cap 7, and an electrode 9 held by a holder 8 is inserted from the other end (lower end) into the brass tube as shown in FIG. After that, the gas introduction pipe 10 is connected to the open end of the exhaust pipe 6, and the gas introduction pipe 10
An inert gas 3 is caused to flow into the raw tube 1 from the inert gas 3. Next, one side of the raw tube 1 is heated and melted with a flame 4, and an electrode 9 is sealed using a press head (not shown) or the like as shown in FIG. Further, the camp 7 on the other side of the tube 1 is removed, the tube 7 is inverted, and the electrode 9 is inserted and sealed in the same manner as described above, thereby manufacturing an arc tube as shown in FIG. 9.

However, in the conventional manufacturing method described above, the axes of the pair of sealed electrodes 9 and 9 do not match the tube axis of the arc tube, causing the optical axis to shift, and the electrode gap due to inversion of the tube 1. Dispersion in distance, etc. will occur. For this reason, in miniature arc tubes with an inner volume of less than 1 cubic meter, the emitted light color may differ partially when lit, and the distance between the electrodes varies, causing significant changes in electrical and optical characteristics. It became.

[Summary of the invention]

This invention was made with the aim of improving this drawback, and involves heating and melting the central part of the raw tube, which is held at both ends, bending it, and then putting it into a mold and forming it into a U-shape.

By attaching an exhaust pipe to the center of the raw tube and sealing electrodes to the openings at both ends, it is possible to eliminate local changes in luminescent color caused by misalignment of the electrode axis and tube axis, and electrical problems caused by changes in the distance between the electrodes. The present invention provides a method for manufacturing an arc tube without optical fluctuations.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 10 to 18. First, as shown in FIG. 10, both ends of the raw pipe 1 cut to a predetermined size are held by the holder 2°2, and while the raw pipe 1 is rotated, the central part is heated and melted by the flame 4, as shown in FIG. It is curved like this. Next, the opening at one end of the raw tube 1 is closed with a cap 7, and the raw tube 1 is placed in a full mold 5a, and an inert gas 3 is pressurized inside the tube to form it into a U-shape as shown in FIG. After that, as shown in FIG.
The curved portion of the tube is heated and melted by flame 4, and inert gas 3 is introduced under pressure into the tube to blow it out as shown in FIG. Then, as shown in FIGS. 15 and 16, an exhaust pipe 6 is welded and communicated with the blown-out portion 1b while being melted by the flame 4. The blank pipe 1 formed as described above is held by the holder 11 at the middle part of the exhaust pipe 6, and the gas introduction pipe 10 is attached to the exhaust pipe 6, as shown in FIG. 17 from both open ends of the blank pipe 1. After the electrode 9 held by the holder 8 is inserted into the tube, the inert gas 3 is introduced into the tube from the introduction tube 10 to replace the atmosphere. In this way, the entire outer periphery of the raw tube 1 is heated and melted by the flame 4, and a vincher head (not shown) is used to attach the electrodes 9, 9 as shown in FIG.
By sealing them together, an arc tube as shown in FIG. 19 can be manufactured.

In addition, in the embodiment, after forming the raw pipe 1 into a U-shape, the exhaust pipe 6 is
Although we have shown an example in which the arc tube is attached, it is also possible to attach the exhaust pipe before forming it into a U-shape, or to form it into a U-shape after sealing the electrodes, and the arc tube is limited to a U-shape. It does not have to be a shape, but may have other shapes.

〔Effect of the invention〕

As explained above, according to the present invention, in an arc tube having an inner volume of 1 or less, the steps of heating the center of the tube, forming the tube into a predetermined shape by molding, and The manufacturing process consisted of a step of blowing out the tube, a step of connecting the exhaust pipe to this part, and a step of inserting and sealing the electrode into the open end of the tube in parallel with these steps, so that the electrode axis and tube axis were There is no local change in the emitted light color due to misalignment, and since the electrodes can be sealed all at once, the distance between the electrodes can be set before sealing, and the electrical and optical characteristics are maintained without fluctuations in the distance between the electrodes. It has the effect of significantly improving the

[Brief explanation of the drawing]

1 to 9 are diagrams showing the conventional arc tube manufacturing process, and Figures 1θ to 19 are diagrams showing the manufacturing process according to an embodiment of the present invention. 1...Made pipe, 2...-holder, 5a...molding,
6... Exhaust pipe, 7... Camping, 8... Holder, 9
...Main rod, 10...Gas introduction pipe. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1, 1 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 13 Figure 14 Figure 15 Figure 16-1 Figure 18] Figure 19 Continued from page 1 ■Inventor: Kanji Seibe

Claims (1)

[Claims] There are two steps: heating the center of the straight tube that will become the luminous tube, molding the tube into a predetermined shape, blowing off the heated center of the tube, and installing an exhaust pipe in the blown-out section. A miniature high-pressure pot steam release system characterized by the following steps: a step of connecting an electrode, a step of inserting an electrode into the open end of the raw tube in parallel with these steps, and a step of heating and melting the open end to seal it. A method of manufacturing an arc tube for electric lights.