JP2000076998A - Method and apparatus for manufacturing metal halide lamp - Google Patents

Abstract

(57) [Problem] In a conventional method for manufacturing a metal halide lamp, when forming a secondary sealing portion, a metal halide placed in a discharge chamber moves, is melted and adheres to an inner wall of a bulb, and airtightness is obtained. Has been reduced to cause an initial failure. According to the present invention, a method for manufacturing a metal halide lamp in which a position regulating step for preventing metal halide grains 3 from moving to the vicinity of a secondary sealing portion 1b is performed before forming a secondary sealing portion 1a. By performing the secondary sealing, the metal halide grains 3 are moved to the vicinity of the secondary sealing portion 1b by the rotation given to the valve 1 when performing the secondary sealing, heated, melted and evaporated, and thereafter closely contacted by the pinch seal. The present invention solves the problem by preventing the adhesive from adhering to the inner surface of a valve to be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal halide lamp used as a light source for a headlamp of an automobile or a light source for a liquid crystal projector, and more particularly to a method and a method for manufacturing the metal halide lamp. It concerns the device.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional metal halide lamp manufacturing method and a manufacturing apparatus 80, in which metal halide grains 92 are put in a discharge chamber 91 of a bulb 90 in which a primary sealing portion 90a is formed. In this state, the discharge chamber 91 and the secondary sealing portion 90b are partitioned by the partition plate 81,
The discharge chamber 91 side is cooled by spraying liquid nitrogen N from a supply device 82, and the secondary sealing portion 90 b side is heated and melted by a burner 83, and then the secondary sealing portion 90 b is pinched by a pinch sealer 84. It is manufactured by performing pinch seal processing or the like.

[0003]

However, in the above-described conventional manufacturing method, when the secondary sealing portion 90b is heated by the burner 83, the shaft is mounted on the valve 90 so that the entire circumference thereof is uniformly heated. Since rotation about Z must be given, the metal halide particles 92 placed in the discharge chamber 91 move with the rotation of the bulb 90 described above.

At this time, when the movement of the metal halide particles 92 occurs in the direction approaching the partition plate 81, the metal halide particles 92 are melted and evaporated by the heat of the burner 83, and are sealed by a pinch sealer 84 as shown in FIG. The vaporized metal halide 92a adheres to the inner wall of the secondary sealing portion 90b or the electrode 93, the molybdenum foil 94, or the like before the sealing is performed, which causes a problem of impairing the airtightness after performing the pinch seal. Becomes

When the metal halide grains 92 shift to the secondary sealing portion 90b as described above, the amount of metal halide in the discharge chamber 91 becomes insufficient, and for example, poor start-up, poor brightness, etc. Causes the problem of lowering the yield of metal halide lamps.
The solution of these points has been an issue.

In order to prevent the movement of the metal halide particles 92 due to the rotation of the valve 90 in the direction of the secondary sealing portion 90b, the secondary sealing portion 90b is set in a state where the axis Z of the valve 90 is vertical. A method of heating with a burner 91 has also been proposed.
However, on the other hand, uniform heating of the secondary sealing portion 90b becomes extremely difficult due to convection of the atmosphere and the like, and sealing failure due to this reason may occur. It cannot be a drastic solution.

[0007]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a metal halide is placed in a discharge chamber of a bulb which is primarily sealed, and a secondary sealing is performed. In the method for manufacturing a metal halide lamp, before performing the secondary sealing, a position regulating step for preventing the metal halide from moving near a position where the secondary sealing is performed is performed. The problem is solved by providing a method for manufacturing a lamp.

[0008]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 shows a first embodiment of the present invention. In FIG. 1, a valve denoted by reference numeral 1 is a valve. This valve 1 has a primary sealing portion 1 a already formed at one end and a discharge chamber 2. The second embodiment is similar to the conventional example in that the metal halide grains 3 are put in the second sealing portion to form the secondary sealing portion 1b.

Here, in the present invention, when forming the secondary sealing portion 1b, the metal halide grains 3 are devised so as not to move near the secondary sealing portion 1b. In one embodiment, a step of fixing the metal halide grains 3 is performed prior to the step of forming the secondary sealing portion 1b.

In the fixing step, the metal halide grains 3 are heated and melted at a temperature at which evaporation does not occur, and the metal halide grains 3 are brought into close contact with the inner wall of the bulb 1 (discharge chamber 2). In the step of forming the portion 1b, the valve 1 is fixed so as not to move by the rotation applied to the valve 1.

In the first embodiment, as a method of heating the metal halide grains 3, an example is shown in which a YAG laser device 20 capable of heating an object in a spot shape is used. If the primary sealing portion 1a is provided with appropriate means such as cooling the primary sealing portion 1a with liquid nitrogen N, the
The operation can be performed without causing thermal distortion in the portion a.

In this way, the metal halide grains 3
After the temporary fixing is performed, the step of forming the secondary sealing portion 1b is performed. At this time, the metal halide grains 3 do not move even by the rotation of the valve 1, so that the same as the conventional example is performed. In addition, even when the secondary sealing portion 1b is heated with the central axis Z of the bulb 1 horizontal, the metal halide does not adhere to the inner wall of the bulb 1, the electrode 4, or the molybdenum foil 5 without causing the metal halide to adhere. The next sealing portion 1b can be formed.

Therefore, in the first embodiment, not only the occurrence of the slow leak due to the evaporation and adhesion of the metal halide can be prevented, but also the most favorable condition for the occurrence of the slow leak due to the thermal distortion of the valve 1. In this case, it is possible to form the secondary sealing portion 1b in a horizontal state, and thereby to reliably prevent the occurrence of initial failure due to slow leak that occurs after shipping to the market.

Accordingly, although not shown, a secondary sealing portion 1b such as a chuck for supporting the valve 1, a burner, a pinch sealer, a supply device for liquid nitrogen N, or an exhaust device in the valve 1 is provided. A manufacturing apparatus (see FIG. 3 of the conventional example) required for the formation can be exactly the same as the conventional example.

FIG. 2 shows a second embodiment of the present invention. In the first embodiment, the metal halide grains 3 are temporarily fixed through a step of heating and re-melting the metal halide grains 3. However, it is essential that the metal halide grains 3 do not move to the vicinity of the secondary sealing portion 1b in the step of forming the secondary sealing portion 1b. There is no problem.

That is, as described in the section of the prior art, if the central axis Z of the valve 1 is perpendicular to the secondary sealing portion 1b side, the condition is satisfied at least in terms of suppressing the evaporation of the metal halide grains 3b. Will do. This second embodiment was performed with attention paid to this point. The inventor of the present invention has conducted experiments and studies to achieve the present invention, and has found that the inclination angle α of the central axis Z of the valve 1 is secondarily sealed. 1 with the part 1b side facing upward
If the angle is maintained within the range of 5 ° ± 5 °, the metal halide grains 3 do not approach the vicinity of the secondary sealing portion 1b in the process of forming the secondary sealing portion 1b, and the secondary sealing portion 1b is formed. It was found that the process did not cause irregular thermal distortion.

In the second embodiment, the discharge chamber 2 and the secondary sealing section 1b are formed when forming the secondary sealing section 1b.
b, a supply plate 12 for injecting liquid nitrogen N or the like into the discharge chamber 2 for cooling,
A burner 13 for heating a portion of the secondary sealing portion 1b;
The manufacturing apparatus 10 including the pinch sealer 14 for pinch-sealing the heated secondary sealing portion 1b is the same as the first embodiment and the conventional example.

Here, the actual implementation of the step of forming the secondary sealing portion 1b will be described. For example, a chuck for supporting the valve 1 which has been conventionally used in this type of step is described. , Burner, pinch sealer, liquid nitrogen N supply device, or exhaust device in valve 1
It is sufficient that the entire manufacturing apparatus 10 required when forming the secondary sealing portion 1b is inclined such that the secondary sealing portion 1b faces upward within the above-mentioned range of 15 ° ± 5 °. Other than the above, the YAG laser device 20 described in the first embodiment and the like can be implemented without any additional device or additional step.

[0019]

As described above, according to the present invention, before the secondary sealing is performed, the metal halide is subjected to the position regulating step for preventing the metal halide from moving near the position where the secondary sealing is performed. With the method of manufacturing the lamp, the metal halide grains are moved to the vicinity of the secondary sealing portion by the rotation given to the bulb when performing the secondary sealing, heated, melted, evaporated, and thereafter pinch-sealed. The metal halide adheres to the inner surface of the valve where the close contact is to be performed, thereby reducing the degree of sealing and preventing the occurrence of a defect at a relatively early point in time after shipment, which is referred to as an initial defect due to a slow leak or the like. This is extremely effective in improving the reliability of the lamp.

In particular, the position regulating step is a step of inclining the axis of the valve in the range of 10 ° ± 5 ° so that the end on the side where the secondary sealing is performed is upward. ,
The above-mentioned object can be achieved without any additional device or additional step, and an excellent effect of being able to supply inexpensively high-quality products to the market is achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a main part of a first embodiment of a method for manufacturing a metal halide lamp according to the present invention.

FIG. 2 is an explanatory view showing a main part of a second embodiment of the method for manufacturing a metal halide lamp according to the present invention.

FIG. 3 is an explanatory diagram showing a conventional example.

FIG. 4 is an explanatory diagram showing a problem in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Valve 1a ... Primary sealing part 1b ... Secondary sealing part 2 ... Discharge chamber 3 ... Metal halide particles 4 ... Electrode 5 ... Molybdenum foil 10 ... Manufacturing apparatus 11 ... Partition plate 12 ... ... Supplying device 13 ... Burner 14 ... Pinch sealing machine 20 ... YAG laser device

Claims (4)

[Claims] In a method for manufacturing a metal halide lamp in which a metal halide is placed in a discharge chamber of a bulb which has been primarily sealed and a secondary sealing is performed, before the secondary sealing is performed, the metal halide is charged with the metal halide. A method for manufacturing a metal halide lamp, comprising performing a position regulating step of preventing the metal halide lamp from moving to a position near a position where the next sealing is performed. 2. The method according to claim 1, wherein the position regulating step is a step of inclining the axis of the valve by 10 ° ± 5 ° such that the end on the side where the secondary sealing is performed is upward. 2. The method for manufacturing a metal halide lamp according to 1. 3. The method according to claim 1, wherein the position regulating step is a step of heating the metal halide and welding the metal halide to an appropriate position on an inner wall of the bulb. 4. A manufacturing apparatus for a metal halide lamp in which a metal halide is placed in a discharge chamber of a primary sealed bulb and a secondary sealing is performed, wherein the manufacturing apparatus performs a secondary sealing of an axis of the bulb. An apparatus for manufacturing a metal halide lamp, wherein secondary sealing is performed by inclining 10 ° ± 5 ° so that the end on the side is upward.