JPS5966032A - Glass working method - Google Patents

Abstract

PURPOSE:To enable boring at desired position with high accuracy by providing a laser beam shield having low laser beam absorption while withstandable against temperature rise due to irradiation of laser beam. CONSTITUTION:A laser beam shielding rod 13 made of such substance as withstandable against temperature rise due to irradiation of laser beam while having low laser beam absorption, for example metal, is inserted from the inside of a chuck 12 for holding one end 11b of a light emission tube 11 made of silicon glass to the hollow section of at the central portion 11a of said tube 11. Then the laser beam 14 of CO2 collected through a convex lense 15 is irradiated such that the boring section 11c of said tube 11 and the shielding member 13 will be positioned on the light path. Consequently it causes no build-up at the circumference of the hole to enable boring of desired diameter with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a glass processing method for making holes in the wall surface of a hollow glass body using a laser beam.

[Technical background of the invention and its problems]

Conventionally, in the manufacture of arc tubes for hollow glass bodies, such as metal vapor discharge lamps, a hole is drilled in the wall of the arc tube, an exhaust pipe is connected around this hole, and the inside of the arc tube is evacuated through the exhaust pipe before starting. After filling the exhaust pipe with a rare gas, mercury, metal halide, etc., a step is taken in which the exhaust pipe is tipped off near its base.

To explain in more detail the drilling of the wall of the arc tube, as shown in FIG. 1, the arc tube is formed! 2 Close the opening of the quartz tube (1) with a stopper (
2) In (2), seal or apply internal pressure with compressed gas such as air (or nitrogen gas), and partially heat the wall surface with an oxyhydrogen burner flame (3), etc., and increase the internal pressure within the RF to heat the heated area. The method used is to punch through the wall and make a hole (4). However, the diameter of the hole (4) is set to a value commensurate with the inner diameter of the exhaust pipe, which is determined by the size K of the substance enclosed in the arc tube, and is conventionally about 2.0 to 4.0 mm. It was within the range of

Furthermore, the size of the sealed remainder of the exhaust pipe affects the temperature distribution of the arc tube and causes a 12% variation, so
It is desirable to make it as small as possible.

In recent years, demand for high-pressure discharge lamps, which are characterized by high efficiency and long life, has increased as a light source to replace incandescent light bulbs from the perspective of energy conservation, and in response to social demands for use as household light sources, demand for high-pressure discharge lamps has also increased. In particular, from the viewpoint of color rendering properties, it has become necessary to develop smaller metal halide membranes.

However, in the case of small metal halide lamps.

In addition to mercury, various metals or metal halides are filled as fillers, so the temperature distribution, especially the temperature of the coldest part of the arc tube, has a greater effect on the characteristics than other types of lamps. It is important to reduce the diameter of the sealed remaining part of the pipe or the hole for connecting the exhaust pipe and to make it uniform.

For example, in the case of a 40W small metal halide lamp, 9
The size of the arc tube is spherical with an inner diameter of 8 mm, and the filling material is Ar100), 8 rrtg of mercury, and a weight mixing ratio of 1.
:5 scandium iodide and sodium iodide at 2.0 I
T! Enclose each g. Based on the size of these inclusions, the size of the hole drilled in the wall of the arc tube, that is, its diameter, is 1.
An accuracy of 0mm ± 0.2 mm is required; below this lower limit, no inclusions will enter the hole, and if it exceeds the upper limit, leaks will occur from the joint between this hole and the exhaust pipe connected around the hole. This is not preferable because it tends to occur more easily. In addition, the inner diameter of the exhaust pipe is suitably 1.5 mm: 0.2 mm in correspondence with the hole diameter.

Furthermore, since the hole is made by using the internal pressure of the tube to pierce the heated tube wall as described above, 9 raised areas of pierced quartz glass are created on the outer circumferential surface of the tube around the hole. This variation in the raised portion is quite large depending on the heating temperature, heating range, thickness of the tube wall, etc., so it increases the variation in the internal volume of the small arc tube, and has a serious effect on the lamp characteristics. Moreover, such adverse effects tend to be exacerbated as the arc tube becomes smaller. Also.

When drilling a hole in the wall of a hollow glass body, not just in arc tubes, in general, it is required to have a hole in a predetermined position and with a highly accurate hole diameter, and furthermore, the glass bulge around the hole must be minimized as much as possible. It is hoped that this will happen. 1. The present inventors have dealt with this situation.

Laser light has been used as a heat source for glass processing in place of oxyhydrogen burner flame, but this method can cause serious damage to walls other than the processing area, and there is a possibility that there is a platform that can damage the hollow glass body. understood.

[Purpose of the invention]

The present invention has been made in consideration of the various circumstances mentioned above, and includes making a hole with a highly accurate diameter at a predetermined location Wt on the wall surface of a hollow glass body, and creating a bulge of glass around the hole. It is an object of the present invention to provide a glass processing method that causes less damage to the wall surface and causes less damage to the wall surface.

[Summary of the invention]

According to the present invention, the absorption rate of laser light is low inside the hollow glass body in which a hole is to be made in the wall surface, and 1. A laser light shielding body that can withstand temperature rise due to laser light irradiation is inserted, and the laser light is irradiated from outside the hollow glass body so that the above-mentioned portion to be drilled and the shielding body are located on the optical path. It is characterized by making holes in the wall surface.

[Embodiments of the invention]

The details of the present invention will be explained below with reference to one embodiment shown in the drawings. In the figure, (II) is a quartz glass arc tube for a 40W metal halide lamp, with a wall thickness of 0.6 mm.
The central portion (lla) is formed into a hollow spherical shape with an inner diameter of 8 mm, and both end portions (llb) are in the form of a thin tube that will be crushed and sealed in a subsequent process. A chuck that holds one end (nb) of the arc tube. A rod-shaped laser beam shield (131) made of a material that can withstand temperature rise, such as metal, is inserted. (1 (a) is a convex lens 09
A laser beam, for example, a carbon dioxide gas laser beam, is focused through the quartz glass arc tube (11) to drill the planned hole (
IIC), shielding, and body (1 This value is determined by the distance, the beam diameter of the laser beam incident on the convex lens, etc. For example, if the diameter of the planned hole is 1. , O
mm and the laser beam diameter is 10 mm.

When using a convex lens (15) with a focal length of 200 mm.

The surface of the portion (1, 1, c) to be drilled on the wall may be placed at a position about 20 mm away from the focal point toward the convex l/lens side.

According to the above method, the quartz glass in the area where the hole is to be drilled is scattered by the laser beam irradiation, and does not remain inside the hole around the hole as in the case of the conventional method. ．． A highly accurate pore diameter that fully satisfies Omm -1-0.2 mrn can be obtained. Also.

When a predetermined hole is drilled, the laser beam will reach the opposite wall surface (], 1d) facing the two holes, which may cause unexpected situations such as damaging or puncturing the surface of this area. However, according to the above method, a shielding body θ made of a metal with a low absorption rate and a high melting point is inserted into the hollow part of the arc tube (11). Further, the laser beam directed toward the opposite wall surface (lid) is blocked by this shield (1 rise), so the laser light directed toward the opposite wall surface (lid)
damage to the lid) can be completely prevented.

In addition, the shielding body ('sai) is the laser beam shielding and l~
Of course, the width of the hole must be greater than the diameter of the hole to be drilled.

Furthermore, - the position at which the shield (1 (6)) is inserted;

If the position is not right orthogonal to the laser beam, the l/- laser beam reflected from the surface of the θ-ray of the shielding body may be condensed and reflected on other wall surfaces, damaging this wall surface. , if at least the laser beam irradiation surface side of the shielding body 0 is roughened, , iJ@shielding body (1), the arrangement position 1ρ, V1.

Even if there is a slight deviation, the light is diffusely reflected and there is no point where it is condensed and reflected on a part of the wall surface, so damage to the wall surface other than the hole area can be prevented.

Note that the 1/- laser light shielding body is not limited to metal, and the important thing is that the absorption rate of the laser light used is low.

Moreover, any material may be used as long as it can withstand the temperature rise when the laser is irradiated. 1/-The light used in the present invention is carbon dioxide (CO2) L/-The Ruby Ray SuZ YAG
There are lasers, etc., but YAG lasers cannot produce a large output, so they are suitable for thin walled objects, but the processing speed for thick walled objects is inferior to the other lasers mentioned above. In addition, the laser beam shielding body is a metal, preferably a high-melting point metal in the case of a carbon dioxide laser, and a metal or ceramic coated with a reflective film for wavelengths of about 1 μm and about 0.7 μm, respectively, in the case of a YAG laser and a ruby laser. , silicon, etc. are suitable.

Furthermore, the present invention is not limited to the above embodiments,
Similar remarkable effects can be obtained even when applied to other bulbs, for example, when drilling a hole for connecting an exhaust pipe in a halogen bulb.

In addition, in the glasswork of hollow glass bodies such as glass tubes,
It is also possible to apply the process to one culm by drilling desired holes in the wall surface.

[Results of invention]

As described in detail above, the present invention utilizes laser light in a glass processing method for making a hole in a desired wall surface of a hollow glass body, and also injects a laser beam with a low absorption rate into the interior of the hollow glass body. By inserting a shield into the hole, it is not only possible to drill a hole with a highly accurate hole diameter in the desired position, but also to prevent the glass from building up around the hole, and to make it easier to drill holes in L7. Effects such as no damage caused by the laser beam to other wall surfaces can be obtained.

[Brief explanation of drawings]

FIG. 1 shows a conventional method, and FIG. 2 shows an embodiment of the present invention. U...quartz glass arc tube, (,11c)...
Planned hole drilling area, 0th floor...Shielding body, θ4...Laser light, (151...Convex lens. Agent: Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] (1) In addition to the method of making a hole in the wall surface of a hollow glass body, a laser beam shielding body is inserted inside the hollow glass body, and a hole is to be formed between the laser beam shielding body and the wall surface. (211/-v') Y,; 1) fq i & body shape at least l/-ri" light 11 (1
(3) A patent claim in which the feature is that the hollow glass body is a tube. The glass processing method according to claim 1 or 2. (4) The glass processing method according to claim 3, wherein the nose light shield is made of metal.