JPH01134833A - Manufacture of metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To have a discharge lamp having a constant chip bore regardless of the wall thickness difference, eccentric fillet, etc., of a light emitting tube by sealing both ends of the light emitting tube, heating and softening areas around the part to undergo chip fixing process, sensing the softening condition with a micro-pressure sensor device, and then sending by pressure a gas from one of the sealed ends. CONSTITUTION:From a gas pressure-feed pipe 12 a gas with a specified pressure is sent to a light emitting tube 1 consisting of quartz, etc., of a metal vapor discharge lamp, and areas of chip hole 4 are heated by a mixed flame given by a burner 11. At this time, change of the pressure P in the light emitting tube 1 is sensed by a micro-pressure sensor device 5 at the single side closed part 10a of the light emitting tube 1. At the time t0 when heating of the tube 1 by the burner 11 causes commencement of penetrating the chip hole 4, a max. pressure P0 is given, and after passage of the time t0, the pressure P is dropped by and by till the time t1. After the device 5 senses the time t0, baking is continued for a specified period of time so as to form the desired bore.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a metal vapor discharge lamp, and in particular to a welding process for attaching an arc tube chip to this type of high-pressure discharge lamp.

[Conventional technology]

FIG. 5 shows an explanatory diagram of the structure of an example of a light emitting portion of a conventional high pressure discharge lamp of this kind. A pair of electrodes 7.78 are arranged at both ends of the arc tube 1 made of quartz or the like, and a molybdenum metal foil 2.2a is connected to each electrode 7, 7a, respectively.

3.38 indicates a sealing portion in which molybdenum metal foil 2°2a is sealed. Reference numeral 4 denotes a chip hole for joining/welding a chip tube passed r1 through a part of the arc tube 1, and is a portion to which a chip tube (exhaust pipe) 8, which will be described later, is welded. The tip tube 8 serves as an exhaust tube and is necessary for exhausting the interior of the arc tube 1.

The conventional method for attaching the tip tube 8 is to make a hole with a welding burner and join the tip portions, as disclosed in, for example, Japanese Utility Model Application Publication No. 57-7152. FIG. 8 shows an example of a conventional device for attaching a chip, in which an arc tube 1 and a sealing part 9.9a that seals both ends of the arc tube 1,
It is formed by a burner 11 that heats and softens the arc tube 1, a pressure feed tube 12 that feeds pressurized gas into the arc tube 1, and the like.

The inside of the arc tube 1 is maintained at a constant pressure by the pressurized gas, but the gas inside the arc tube 1 expands due to the burner 11, and eventually a part 4 of the wall of the arc tube 1 melts/penetrates, leading to a chip. form a hole.

[Problem that the invention seeks to solve]

However, as mentioned above, the arc tube tip attachment portion 4
Figures 6 (a) and (b) show two examples of defective tip attachment even under the same heating conditions: softening with a burner such as a mixed flame of gas and oxygen and making a hole in the welded part of the tip tube. As shown in figure (b), which shows two side views of each, when the wall thickness of the arc tube 1 is thin, the chip hole 6 becomes large, and the wall thickness of the joint part becomes thin. When the wall thickness of the arc tube is thick, as in the example shown in FIG.

(The wall thickness of the arc tube in both figures (a) and (b) is exaggerated.) This invention was made in view of the problems of the conventional example as described above. The object of the present invention is to provide a method for manufacturing an arc tube with a chip that can obtain a constant chip hole diameter without being influenced by the thickness of the chip or uneven thickness.

(Means for Solving the Problems) Therefore, in the manufacturing method of the present invention, in the chip attaching process for welding the chip tube to a part of the quartz tube, etc., both ends of the arc tube are sealed and the arc tube is closed. After heating and softening the vicinity of the area to be processed for chip attachment, and detecting the softened state using a micro-pressure detection device at one end of the sealed end of the arc tube, the diameter of the chip hole is drilled by pumping gas from the other sealed end. By adopting a method in which the firing conditions for hole diameter adjustment are determined based on the above-mentioned micro-pressure detection time,
This aims to achieve the above objective.

(Function) According to the manufacturing method described above, gas at a constant pressure is fed into the inside of the quartz tube, the part where the tip is to be attached is heated and melted by a burner, and the softened part is detected by detecting the pressure fluctuation inside the quartz tube. By knowing the wall thickness of the arc tube and using the detection time to set the firing conditions for adjusting the hole diameter, it is possible to mold a constant hole diameter, and it is possible to mold the hole with a constant diameter. It is possible to obtain an arc tube with no variations in the size of the chip hole diameter or the wall thickness of the chip attachment portion.

〔Example〕

Hereinafter, the present invention will be explained based on examples.

(Device Configuration) FIG. 1 shows an explanatory diagram of an embodiment of the tip tube welding process according to the present invention. At one end of the arc tube 1, there is a sealed part lO1 having a gas pressure feed pipe 12; at the other end there is a low pressure detection device 5.
A sealing portion 10a is provided in which the sealing portion 10a cannot be attached.

(Process) Next, details of the process will be explained. Luminescent tube! Prepare 30 (quartz valves φ15+ue wall thickness 1.On+s), apply N2 gas pressure of 0.1 g7cm" from the pressure feed pipe 12,
The joint portion 4 was heated by a burner 11 using a mixed flame of LNG and oxygen. At this time, the pressure change inside the arc tube 1 was detected by the micro-pressure detection device 5 in the sealed portion 10a on one side of the arc tube 1, and a temporal change characteristic diagram of the pressure P inside the arc tube 1 shown in FIG. 2 was obtained. . That is, FIG. 2 is a characteristic curve diagram obtained by measuring the change in the pressure P of the arc tube 1 using the micro-pressure detection device 5.
This is the time when the arc tube 1 is heated and the welded part 4 begins to penetrate. After this time point t0, time point 1. Until then, the pressure P gradually decreases. This change is because the arc tube chip hole portion 4 expands with time t, and each time t0 and tl are factors related to the chip hole diameter.

In order to find out the relationship between the penetration time t0 and the wall thickness of the arc tube 1 using the above method, FIG. 9.1.0
, 1.1+sm, 10 each, for a total of 60 data. It is shown that the thicker the wall, the longer the time to. Based on the above, FIG. 4 is a diagram showing a characteristic curve of the relationship between the firing time t after time t in FIG. 2 and the chip hole diameter. The hole diameter gradually increases with firing time.

From the above figures, in order to obtain the optimum hole diameter for the chip hole diameter, it is possible to obtain the desired hole diameter by continuing firing for a predetermined period of time after detecting time t0 by the micro-pressure detection device 5. I can do it. As a result of actually attaching chips to 100 luminous tubes 1 having different wall thicknesses and uneven thicknesses using the method of this invention as described above, the results shown in FIGS. 6(a) and (b) were obtained.
No defects such as those shown in 2 were observed.

〔Effect of the invention〕

As explained above, according to the present invention, a tube with a tip having a constant tip hole diameter can be used without being influenced by slight differences in wall thickness or uneven thickness of the arc tube of this type of metal vapor discharge lamp. can now be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating an embodiment of the chip attaching method according to the present invention, FIG. 2 is a characteristic diagram of an example of micro-pressure changes in the arc tube with respect to firing time for chip attachment, and FIG. An example of a characteristic diagram showing the relationship between wall thickness and chip penetration time to,
FIG. 4 is an example of a characteristic diagram showing the relationship between the heating time and the chip hole diameter after time to, FIG. Figure (a). (b) shows two diagrams of two cases of defective chip attachment, respectively;
FIG. 7 is a perspective view after chip attachment, and FIG. 8 is an explanatory side view showing an example of a conventional chip attachment method. In the figure, 1 is an arc tube, 5 is a micro-pressure detection device, 6 is a tip attaching part, 10 and 10a are closed ends, 11 is a burner, and 12 is a gas pressure feeding tube. In each figure, the same reference numerals represent the same or equivalent components.

Claims (1)

[Claims] In the tipping step of welding a tip tube to a part of an arc tube made of quartz or the like, both ends of the arc tube are sealed, and the vicinity of the portion of the arc tube where the tip is to be attached is heated and softened, and the above-mentioned sealing of the arc tube is performed. After detecting the softened state by the pressure detection means at one end, the tip hole is drilled by pumping gas from the other sealed end, and
A method for manufacturing a metal vapor discharge lamp, characterized in that firing conditions for adjusting the hole diameter are determined based on the predetermined micro-pressure detection time from the time when the tip hole starts penetrating.