JPH065257A - Discharge lamp device - Google Patents

Abstract

PURPOSE:To obtain a compact discharge lamp device in which the forming and the attaching of SiO2 to the surface of an arc tube can be prevented. CONSTITUTION:The rear end opening of a cap type glass globe 20 for shielding untraviolet ray to which a glass tube is provided connecting to its front end, which operates as an inert gas feeding hole, and then is sealed by a pinch seal or a shrink seal, is welded to a glass flange provided connecting to the rear end periphery of an arc tube 10, so as to form an arc tube-globe connection body A whose arc tube periphery is sealed up. And a lead wire 18a led out from the front end of the arc tube is led out from the glass tube sealing part 22 at the front end of the globe to the outer side of the globe, the rear end of the arc tube-globe connection body A is fixed and held to an insulating type base 30, and a lead wire 18c led out from the front end of the globe is held by a lead support 40 extending from the insulating type base 30 to the front side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp device used as a light source for automobiles, and more particularly to a discharge lamp device in which an arc tube arranged in front of an insulating base is surrounded by an ultraviolet shielding globe.

[0002]

2. Description of the Related Art In recent years, as a light source for an automobile headlamp, an incandescent lamp has been replaced with a halogen lamp having a large amount of light, and recently, a discharge lamp having a larger amount of light and a long life has been developed. FIG. 5 shows a previously proposed discharge lamp device of this type.
Both ends of the arc tube 5, which is the main body of the discharge lamp, are supported by a pair of lead supports 3 and 4 projecting therefrom. The actuating tube 5 has electrodes 6 and 6 arranged in a sealed glass ball 5a at the center of the glass tube, and the glass tube has a pinch seal portion 5b for sealing molybdenum foils 7 and 7 connected to the electrodes 6 and 6, 5b is formed, lead wires 8 and 8 connected to the molybdenum foils 7 and 7 are led out from the pinch seal portions 5b and 5b, and the lead wires 8 and 8 lead through the metal supports 8a and 8b. It is welded and fixed to the supports 3 and 4. In addition to mercury as a luminescent substance, a metal halogen substance (for example, sodium-thallium-indium system or scandium-system) is contained in the glass bulb 5a.
Sodium-based) is included. Reference numeral 9 is a cylindrical ultraviolet shielding glove that is fixedly held on the base 2, and blocks ultraviolet rays in a wavelength range harmful to the human body from the light emission of the arc tube 5 and a wavelength range that deteriorates resin parts in the lamp. ing. Then, this discharge lamp device is inserted into the bulb insertion hole 1a of the reflector 1 and arranged in a lamp chamber space (not shown) formed by the lamp body and the front lens.

[0003]

However, in the discharge lamp device shown in FIG. 5, the circumference of the arc tube 5 communicates with the lamp chamber space through the opening end of the ultraviolet shielding globe 9. And when the headlamp is lit, the arc tube 5
Heats up the inside of the lamp chamber to a high temperature. Due to this high temperature, a sealing agent loaded to seal the engaging portion between the lamp body and the front lens and S provided in the lamp chamber space.
Silicon jumps out from the i-based synthetic resin material as low-molecular siloxane into the lamp chamber space, migrates, combines with O ₂ in the atmosphere near the surface of the arc tube where the temperature becomes high, and adheres to the surface of the arc tube as SiO ₂ . . This attached Si
There is a problem that O ₂ makes the arc tube cloudy white and reduces the luminous efficiency of the arc tube.

Further, as shown in FIG. 6, the ultraviolet-shielding globe 9 has a closed front end, and the open end of the globe is adhered to a ceramic disk fixed to the front surface of the base 2 to seal the inside of the globe 9. However, a structure for preventing SiO ₂ from adhering to the arc tube 5 has also been proposed. However, the adhesive for bonding the gloves has changed over time, and there is concern about the airtightness between the gloves 9 and the disk, and it has not been possible to reliably prevent the adhesion of SiO ₂ for long-term use. Furthermore, since the ultraviolet ray shielding globe 9 has a structure that surrounds the entire arc tube 5 and the lead supports 3 and 4, the discharge lamp device becomes large. Further, the front end 9a of the globe 9 is located in front of the arc tube, and the light reflected by the reflector 1 may be scattered by the front end 9a of the globe to become glare light. There is also a problem that light is cut off at the front end 9a of the globe and the central luminous intensity of the light distribution pattern is insufficient.

The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to form SiO on the surface of the arc tube.
_The purpose of the present invention is to provide a compact discharge lamp device in which ₂ does not stick out.

[0006]

To achieve the above object, in the discharge lamp device according to the present invention, a glass tube which acts as an inert gas supply hole and is then sealed by a pinch seal or a shrink seal is used. Weld the rear end opening of the cap-type glass globe for UV shielding that is coupled to the tube to the glass flange that is coupled to the outer periphery of the rear end of the arc tube to enclose the arc tube and the arc tube. In addition to sealing in the integrated UV shielding globe, the lead wire leading from the tip of the arc tube is led out of the globe from the glass tube sealing part at the front end of the globe to insulate the rear end of the arc tube / groove combination. The lead wire that is fixedly held on the base is supported by a lead support that extends forward from the insulating base. Those were Unishi.

According to a second aspect, in the discharge lamp device according to the first aspect, the lead wire led out from the arc tube and the lead wire led out of the glass tube sealing portion to the outside of the globe are connected to the glass tube sealing portion. The connection is made through a molybden foil that is sealed.

[0008]

[Function] The rear end opening of the cap-type glass globe is welded to the glass flange formed continuously on the outer periphery of the arc tube, and the glass tube at the front end of the globe is sealed by a pinch seal or a shrink seal, and the arc tube is sealed. The area around is kept in a completely sealed state with gloves.

For this reason, the globe for shielding ultraviolet rays which surrounds the arc tube prevents the low molecular weight siloxane (Si) that has jumped out into the lamp chamber space due to the heat generated by the discharge from approaching the arc tube, which becomes a high temperature, and the SiO ₂ Generation and Si
Prevents O _{2 from} adhering to the surface of the arc tube. Since the surface temperature of the globe is lower than that of the arc tube, the low-molecular-weight siloxane (S
i) has a low degree of bonding with O _2, and does not adhere to the gloves as SiO ₂ .

Further, since the globe for shielding ultraviolet rays has a structure in which only the arc tube is enclosed, it is more compact and has a shorter front-rear length than the conventional structure in which the lead support is also enclosed. According to the second aspect, the molybdenum foil sealed in the glass tube sealing portion which is shrink-sealed or pinch-sealed is very thin and has a good compatibility with glass, so that the hermeticity of the sealing portion is ensured.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. 1 and 2 show an embodiment of the present invention.
FIG. 2 is a perspective view of a discharge lamp device which is an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the discharge lamp device, and FIGS. 3 and 4 are explanatory views of a manufacturing process of the discharge lamp device.

In these figures, the discharge lamp device is
The arc tube 10 and a globe 20 which is an outer tube for shielding the arc tube 10 and for shielding ultraviolet rays.
Arc tube / groove combination A in which and are integrated
And an insulating base 30 that is an arc tube support base that supports the rear end of the arc tube / groove combination A.
And a lead support 40 that extends forward from the insulating base 30 and supports the front end portion of the outer tube / groove combination A.

The arc tube 10 is an elliptical closed glass sphere 12 which forms a discharge space by pinching the front end and the rear end of a circular quartz glass tube.
At both ends of the pinch seal portions 13a, 13 having a rectangular cross section.
In the structure in which b is formed, a rare gas for starting, mercury, and a metal halide (for example, a sodium-thallium-indium-based luminescent material) are enclosed in the glass bulb 12.
A discharge electrode 15 made of tungsten is provided in the closed glass bulb 12.
a and 15b are arranged to face each other, and the discharge electrodes 15a and 1b
5b is connected to the molybdenum foils 16a and 16b sealed to the pinch seal parts 13a and 13b, and the pinch seal part 1
Molybdenum foils 16a, 16b from the ends of 3a, 13b
Lead wires 18a, 1 made of molybden respectively connected to
8b is led out, and the lead wire 18b extends through the circular pipe-shaped portion 14b, which is a non-pinch seal portion, to the outside.
On the other hand, the front end side lead wire 18a is connected to the molybdenum foil 16 sealed in the seal portion 22 at the front end of the ultraviolet shielding globe 20.
It is connected to a lead wire 18c made of molybden which is led out to the front of the globe via c, and this lead wire 18c is connected to a metal support 41 fixed to the tip of the lead support 40. A glass disk is welded and integrated with the circular pipe-shaped portion 14b at the rear end of the arc tube 10 to form a flange portion 24, and the open end of the globe 20 is welded and integrated with the disk (flange portion) 24. As a result, the arc tube / groove combination A is formed.

A glass globe 20 for shielding ultraviolet rays which surrounds the arc tube 10 is a cap type in which a sealing portion 22 is projected on a spherical tip portion, and a rear end opening portion of the globe is formed on a rear end portion of the arc tube 10. It has a structure in which the arc tube 10 is surrounded by being welded to a glass disk (flange portion) 24 that is circumferentially provided. Glass gloves 2
The outside of 0 is coated with an ultraviolet shielding film such as ZnO having an ultraviolet blocking effect.
From the light emission of the discharge section of 0, ultraviolet rays in the wavelength range harmful to the human body and the constituent members of the lamp are cut off.

Initially, the seal portion 22 at the tip of the globe is made up of a glass tube 21 as shown in FIG. 3 (e). Inside the glass tube 21, the molybdenum foil 16c connected to the lead wire 18a is provided. With the lead wire assembly 17 consisting of the lead wire 18c and the lead wire 18c inserted, the glass tube 2
By shrink-sealing 1
Is formed. The molybdenum foil 16c is well compatible with glass, and can ensure the airtightness in the glass tube sealing portion to which the lead wire assembly 17, which is a current-carrying path, is sealed. Further, the glass arc tube 10 and the glass disc (flange portion) 24, and the glass disc (flange portion) 24 and the glass globe 20 are integrated by welding to ensure the airtightness of the respective joints. An inert gas is enclosed in the glove 20 which is in a completely sealed state, and the glove 2 is protected by the heat insulating effect of the inert gas.
The surface temperature of 0 can be kept low. For this reason, the temperature rises during the lighting of the discharge lamp device, so that the sealing agent loaded in the engaging portion between the lamp body, which is a headlamp constituent member, and the front lens and the silicon-based synthetic resin in the lamp chamber space. The low-molecular-weight siloxane that has jumped out of the material cannot contact the arc tube 10 having a high surface temperature even if it contacts the globe 20 having a low surface temperature, so that the generation of SiO ₂ is suppressed and even if it is generated. Also, there is no possibility that the generated SiO ₂ adheres to the arc tube. Therefore, the arc tube 1
There is no problem as in the prior art that 0 is clouded white and the luminous efficiency is reduced.

The globe 20 is coated with an ultraviolet ray shielding film such as ZnO for cutting off ultraviolet rays. The durability of this ultraviolet ray shielding film tends to decrease at high temperatures, but the inertness inside the globe 20 is low. Because the heat insulation effect of the gas suppresses the temperature rise of the ultraviolet shielding film,
The durability of the UV shielding film is also guaranteed. Reference numeral 26 is a getter that is welded and fixed to the lead wire 18a and that adsorbs and removes impurity components (for example, gases such as H ₂ and O ₂ ) in the globe 20.

The insulative base 30 is an integrally molded body of synthetic resin, and a lead support 40 insert-molded on the front surface of the base 30 extends forward. A ceramic disk 34 is fixed to the front surface of the base 30 by a screw 32, and an arc tube engaging hole 31 formed in the front surface of the base 30 is engaged with a rear end of the arc tube. An area corresponding to the flange portion 24 is fixed to the ceramic disk 34 with an inorganic adhesive 36. The lead wire 18b on the rear end side of the arc tube is led out from the small hole 31a provided on the bottom surface of the arc tube engaging hole 31 to the back side of the base, and a part of the connector projecting on the back side of the base 30. Is welded to the terminal 37.

On the other hand, the lead wire 1 on the front end side of the arc tube
The molybdenum foil 8a is connected to the molybdenum foil 16c sealed in the front end seal portion 22 of the globe 20.
A lead wire 18c made of molybdenum is led out of the globe 20 from 6c. The lead wire 18c is connected to the metal support 41 fixed to the tip of the lead support 40 by spot welding, and the lead support 40, which acts as a current-carrying path to the front end side lead wire 18a, is provided in the base 30. The terminal 38 which is a part of the connector is formed by bending and projecting to the back side of the base. Reference numeral 42 is a ceramic pipe fitted on the lead support 40 to prevent discharge. Power supply cords C ₁ and C ₂ are connected to the terminals 37 and 38, respectively, and the base 30 is provided between the terminals 37 and 38.
A bifurcated partition 39 extends from the bifurcated partition 39 and has a code C.
The partition wall 52 on the plug cover 50 side through which ₁ and C ₂ are inserted and held is engaged to prevent discharge between the terminals 37 and 38.

Reference numeral 46 is a focusing ring fixed to the peripheral edge of the insulating base 30. The focus ring 46, which is a reference contact portion when the discharge lamp device is positioned in the bulb insertion hole of the reflector, and the insulative base 30 have a metal ring 47 interposed between the mating surfaces of both members 46, 30. Although the structure allows relative sliding in the circumferential direction and the axial direction (left and right direction shown in FIG. 2), high frequency induction heating is performed at a position where the sealed glass bulb 12 which is the discharge part and the focus ring 46 are positioned in the axial direction and the circumferential direction. Thus, the metal ring 47 is heated so that the abutting surfaces of both members 30, 46 are welded and integrated.

Next, the manufacturing process of the discharge lamp device of this embodiment will be described with reference to FIGS. First, FIG. 3 (a)
3 is prepared, and the lead wire assembly 17 in which the molybdenum foil 16c and the lead wire 18c are integrated is connected to the arc tube front end side lead wire 18a as shown in FIG. 3 (b). Further, as shown in FIG. 3C, the getter 26 is connected to the lead wire 18a, and as shown in FIG. 3D, the glass disk (flange portion) 24 is arced by a heat source such as a CO ₂ laser. Weld to the rear end of the tube.

Next, as shown in FIG. 3 (e), the ultraviolet ray shielding globe 20 is put over the arc tube 10,
The lead wire assembly 17 is inserted into the glass tube 21 connected to the tip of the globe, the lower end opening of the globe 20 is engaged with the disc (flange portion) 24, and the globe 20
And the disk (flange portion) 24 are welded together by a heat source such as a CO ₂ laser.

Next, as shown in FIG. 4A, the glass tube 2
The inside of the globe 20 is evacuated to vacuum via 1 and then an inert gas is injected to replace the inside of the globe 20 with the inert gas, and the glass tube 21 is sealed with a shrink seal to form a seal portion 22. Next, as shown in FIG. 4B, an insulating base 30 having a ceramic disk 34 fixed to the front surface and a lead support 40 protruding therefrom is prepared, and the rear end of the arc tube is inserted into the tube engaging hole 31. After the insertion, the rear end portion of the arc tube / groove combination A is adhered and fixed to the ceramic disk 34. At this time, the rear end side lead wire 18b of the arc tube is passed from the small hole 31a to the base 3
It is made to project to the back side of 0. Further lead support 4
The lead wire 18c led out from the front end of the globe is spot-welded to the metal support 41 fixed to the front end of 0.

Next, as shown in FIG. 4C, the base 30
A terminal 37 is screwed on the back side of the and the lead wire 18b is spot-welded to the terminal 37. Further, the cords C ₁ and C ₂ are connected to the terminal 37 and the terminal 38 that is the base rear protruding portion of the lead support 40, and the plug cover 50 is provided.
Is engaged with the base 30, and the metal ring 47 is attached to the engaging portions of both members 50, 30. Next, as shown in FIG. 4D, the focus ring 46 is attached, alignment for adjusting the focus ring position is performed, and the plug cover 50, the base 30, and the focus ring 4 are adjusted by high frequency induction heating.
Integrate 6 and.

In the above embodiment, the seal portion 22 which is the glass tube sealing portion is formed by the shrink seal, but it may be formed by the pinch seal. Further, in the above-described embodiment, the front end side lead wire (molybdenum wire) 18a of the arc tube is connected to the lead wire 18c through the molybden foil 16c sealed in the glass tube sealing portion 22, but the structure is not limited to the globe. 20 is made of quartz glass (coefficient of linear expansion 5.0 × 10
⁷ to a hard glass (coefficient of linear expansion 43 × 10 ⁷ ) close to the coefficient of linear expansion of molybdenum wire (52 × 10 ⁷ ), the lead wire (molybdenum wire) 18a is directly sealed by the sealing portion 22, The line 18a may be directly led out to the front of the globe.

[0025]

As is apparent from the above description, according to the discharge lamp device of the present invention, the arc tube is surrounded by the ultraviolet ray shielding globe and is kept in a completely sealed state. The low-molecular-weight siloxane that jumps out into the lamp chamber space due to the rise in the room temperature does not migrate to the vicinity of the surface of the high-temperature arc tube, and Si
Generation of O ₂ and adhesion of this SiO _{2 to} the arc tube are suppressed, and a decrease in luminous efficiency of the arc tube is prevented. Since the surface temperature of the globe is lower than that of the arc tube, the oxidation reaction of Si (low molecular weight white saquine) is suppressed and SiO ₂ does not adhere to the globe.

Further, since the globe for shielding ultraviolet rays has a structure in which only the arc tube is surrounded without surrounding the lead support, it is very compact as compared with the conventional structure. Also, because it is shorter than the conventional globe, the reflected light from the reflector is scattered at the front end of the globe and becomes glare light as in the conventional structure, or the light is cut at the tip of the globe and the luminous intensity at the center of the light distribution pattern is reduced. There is no problem such as shortage. Further, since the lead support is not exposed to ultraviolet rays unlike the conventional structure provided in the glove, the lead support is not easily denatured, and the durability of the lead support is secured accordingly.

The high temperature state of the arc tube is insulated by the inert gas atmosphere surrounding the arc tube and transmitted to the ultraviolet ray shielding globe, so that the durability of the ultraviolet ray shielding film formed on the globe is suppressed. . Further, since the arc tube can be kept in a heat insulating atmosphere in the globe to maintain a constant operating temperature, it is possible to stabilize the luminous flux, color and temperature of the headlamp.

[Brief description of drawings]

FIG. 1 is a perspective view of a discharge lamp device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of the discharge lamp device.

FIG. 3 is a diagram showing a manufacturing process of the same discharge lamp device, and a diagram for explaining a process up to fixing the arc tube in the ultraviolet shielding globe.

FIG. 4 is a diagram showing a manufacturing process of the discharge lamp device, which is a diagram illustrating a process from shrink-sealing a tip portion of the ultraviolet shielding globe to completion of the discharge lamp device.

FIG. 5 is a vertical sectional view of the previously proposed discharge lamp device.

FIG. 6 is a vertical sectional view of another previously proposed discharge lamp device.

[Explanation of symbols]

 10 Arc tube which is a discharge lamp body 12 Closed glass bulb which is a discharge part 13a, 13b Pinch seal part 14b Cylindrical part 15a, 15b Discharge electrode 18a Lead wire leading to the front end side of the arc tube 18c Lead wire leading from the front end of the globe 20 UV Shield Gloves 21 UV Shield Gloves Glass Tube Formed at the Tip 22 Glass Tube Sealing Part 30 Insulating Base 34 Ceramic Disc 36 Adhesive 40 Lead Support A Arc Tube / Glove Combine

Claims (2)

[Claims] 1. A rear end opening of a cap-type glass globe for ultraviolet shielding, which has a glass tube acting as an inert gas supply hole and subsequently sealed by a pinch seal or a shrink seal and connected to the front end, It is welded to the glass flange that is connected to the outer periphery of the rear end of the arc tube,
The arc tube is hermetically sealed in the UV shielding globe that surrounds and integrates the arc tube, and the lead wire that is led from the tip of the arc tube is led out of the globe from the glass tube sealing part at the front end of the globe to join the arc tube and globe. The rear end of the body is fixedly held on the insulating base,
A discharge lamp device, wherein a lead wire extending from the front end of the globe is supported by a lead support extending forward from the insulating base. 2. The lead wire led out from the arc tube and the lead wire led out from the glass tube sealing portion to the outside of the globe are connected via a molybden foil sealed in the glass tube sealing portion. The discharge lamp device according to claim 1, wherein: