JPH0574204A - Automotive head lamp - Google Patents

Abstract

PURPOSE:To prevent light reflected by a reflector from being eclipsed by forming the front end part of a UV radiation shielding glove in a tapering shape so as not to interfere with light reflected in a light reflecting surface area on the peripheral edge of a reflector bulb insertion hole. CONSTITUTION:The front end part of a UV radiation shielding glove 50 is formed smaller in aperture than an area 52 corresponding to a discharge unit of an arc tube 34, and is made into aperture so as not to interfere with light L2 and L3 reflected by the light reflecting surface 22a formed around a bulb insertion hole 23 of a reflector 22. That is, since there exists no glove 50 on light passages of the lights L2 and L3 contributive to light distribution by being reflected by the reflector 22, a part of the lights contributive to the light distribution by being reflected by the reflector is hardly eclipsed by the glove 50. Thereby, sufficient light is distributed in a hot zone area, so that a light distribution pattern having both proper size and sufficient illumination intensity can be obtained. As for emission from the discharge unit, UV radiation in a harmful wavelength area is cut by the glove 50, so that the influence is hardly exerted upon a human body or a head lamp constituting part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlamp using an arc tube as a light source.

[0002]

2. Description of the Related Art As shown in FIG. 5, an arc tube 1 is a rod-shaped body in which a pair of pinch seal portions 1b, 1c extend forward and backward from a closed glass bulb 1a.
The lead wire 2 (2a, 2b) connected to the counter electrode in the closed glass bulb 1a is led out from the end of 1c. Then, the lead wires 2 (2a, 5a, 5b) are welded and fixed to the pair of long and short lead supports 4 (4a, 4b) projecting forward of the lamp base 3.
2b) is welded and fixed, and a discharge lamp device in which the arc tube 1 is supported at both ends is configured.

Since this discharge lamp device has good luminous efficiency and color rendering property, research has been conducted to use it as a bulb for automobile headlamps. However, the arc tube emits light from the human body and headlamp components. Since ultraviolet rays in the harmful wavelength range are contained in the, it is necessary to cut off the ultraviolet rays in this harmful wavelength range. As a means for cutting off the ultraviolet rays, as shown in the figure, there is a structure in which the ultraviolet ray shielding globe 6 surrounding the arc tube 1 is fixed to the base 3 and integrated with the discharge lamp device.

As shown in FIG. 5, when the discharge lamp device is used as a bulb for a projection type head run in which the light reflected by the reflector 7 having a substantially ellipsoidal shape is projected and distributed by a projection lens 8 (hereinafter, referred to as a bulb). As shown by the arrow in FIG. 5, most of the light emitted from the discharge part (closed glass bulb) 1a of the arc tube provided at the first focus position of the reflector 7 is reflected by the reflector 7. Then, the light passes through the second focal point on the optical axis and is projected and distributed by the projection lens 8 forward to form a predetermined light distribution pattern. However, a part of the light reflected by the reflector 7, in particular, the light L ₁ reflected by the light reflection surface area 7a around the bulb insertion hole is reflected, absorbed, refracted, etc. at the tip of the ultraviolet shielding globe 6 (hereinafter Since this is referred to as vignetting of light), the illuminance at the central portion of the light distribution pattern is reduced, which causes a problem that it is not preferable in light distribution. Reference numeral 6a is light L ₁
Indicates a part that is vignetted. And if the length of the arc tube 1 is reduced (the length of the pinch seal parts 1b and 1c is shortened), the front-back length of the globe 6 can be shortened, and this problem (vignetting of the light reflected by the reflector on the globe) is solved. However, it is difficult to shorten the length of the arc tube 1 from the viewpoint of sealing the lead wire and preventing leakage of the sealing gas in the sealed glass bulb. Further, the diameter of the globe 6 may be made small, but the lead supports 4a and 4b for supporting the arc tube 1 cannot be formed to have a sufficiently small diameter, so that vignetting of light cannot be prevented.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide an electric discharge provided with an ultraviolet ray shielding globe having a shape in which light reflected by a reflector is not vignetted. An object of the present invention is to provide an automobile headlamp using a bulb.

[0006]

In order to achieve the above object, in a vehicle headlamp according to the present invention, a reflector provided in a lamp body and front and rear opening ends of a cylindrical ultraviolet shielding globe. The front and rear ends of the arc tube are fixedly held at the respective parts via ceramic disks to form an arc tube / groove combination, and the rear end of this arc tube / groove combination is fixedly supported by an insulating base. An automotive head including a discharge bulb whose front end is fixedly supported by a lead support protruding from an insulating base, and a lens which is disposed in front of the discharge bulb and which distributes light reflected by a reflector to the front. In the lamp, the front end portion of the ultraviolet shielding globe is reflected by the light reflection surface region around the bulb insertion hole of the reflector. It is obtained so as to form a tapered shape that does not interfere with the light.

Further, in a second aspect of the present invention, the first aspect is applied to a projection type headlamp including a substantially ellipsoidal reflector and a projection lens.

[0008]

According to the first aspect of the present invention, the ultraviolet ray shielding globe has a cylindrical shape, and the arc tube and the ultraviolet ray shielding globe that surrounds the outer tube are integrated through a ceramic disk to form an arc tube / groove combination. Since the structure is such that the arc tube / groove combination is supported by the lead support protruding forward of the insulating base, the lead support does not get in the way when the tip of the globe is tapered. In addition, since the light reflected by the light reflection surface region around the bulb insertion hole of the reflector does not vignet with the globe, an appropriate light distribution pattern can be obtained.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a vertical sectional view of a projection headlamp for an automobile using a discharge bulb as a light source, FIG. 2 is a perspective view of the discharge bulb, and FIG.
FIG. 4 is an enlarged vertical sectional view of a discharge bulb.

In these drawings, reference numeral 10 is a container-shaped lamp body, and a light projection unit 20 is tiltably supported in the lamp body 10 by an aiming mechanism (not shown). Reference numeral 18 is a transparent cover assembled to the front opening of the lamp body 10. The light projection unit 20 is made of a substantially ellipsoidal metal (made of aluminum).
A reflector 22 and a discharge bulb 30 inserted into a bulb insertion hole 23 formed at the rear top of the reflector 22.
And the projection lens 26 is fixed to the front side, and the reflector 2
Made of metal (made of aluminum) attached to the front opening of 2
It has a structure in which the lens holder 24 is integrated. Reference numeral 31 is a locking cap for fixing the discharge bulb 30 to the bulb insertion hole 23, and reference numeral 26a is an annular lens fixing frame for crimping the projection lens 26 to the lens holder 24.

In the discharge bulb 30, an arc tube / groove combination A in which an arc tube 34 and an ultraviolet ray shielding globe 50 surrounding the arc tube 34 are integrated via ceramic disks 32a and 32b is made of a synthetic resin. The discharge base 34 a of the arc tube 34 is disposed at the first focal point position F ₁ of the reflector 22 with a structure in which both ends are supported by the insulating base 40 and the lead support 33 made of metal. In the vicinity of the second focus position F ₂ of the reflector 22, a shade 2 for forming a light distribution pattern for passing light integrated with the lens holder 24 is formed.
5, and a metal leaf spring member 27a on the lens holder 24.
An ultraviolet shielding filter 27 fixedly held by is provided. And the discharge part 34 of the arc tube 34
The light emitted from a is reflected by the reflector 22, converges on the second focal point F ₂ of the reflector 22, and is collimated by the projection lens 26 to be projected forward, but the light passes through the ultraviolet shielding globe 50 and the filter 27. UV rays are cut twice when doing.

The details of the discharge bulb 30 are shown in FIGS.
Is shown in. The arc tube 34 is made of a quartz glass tube having a circular pipe shape, and has pinch seal portions 34b ₁ and 34b ₂ having a rectangular cross section at both ends of a closed glass sphere 34a which is an ellipsoidal discharge portion forming a discharge space. The glass sphere 34a has a structure formed integrally with a starting rare gas, mercury, and a metal halide. Circular pipe-shaped portions 34b ₃ and 34b ₄ which are non-pinch seal portions extend from the pinch seal portions 34b ₁ and 34b ₂ to form both ends of the arc tube 34. Discharge electrodes 35a and 35b made of tungsten are arranged inside the sealed glass bulb 34a so as to face each other. The discharge electrodes 35a and 35b are molybdenum foils 36a sealed to the pinch seal portions 34b ₁ and 34b ₂ , respectively.
36b, lead wires 37a and 37b connected to the molybdenum foils 36a and 36b, respectively, are led out from the ends of the pinch seal portions 34b ₁ and 34b ₂ , and the lead wires 37
a, respectively 37b circular pipe-shaped portion 34b _3, 34b ₄
And extends to the outside.

The globe 50 for shielding ultraviolet rays which surrounds the arc tube 34 is a glass tube having a length slightly shorter than that of the arc tube 34 and having an outer diameter larger than the outer diameter of the arc tube 34. Ceramic discs 32a, 32 engaged with openings at both ends of 50
An arc tube / groove combination A is formed by being integrated with the arc tube 34 via b. That is, the ceramic disks 32a, 32b are provided with recesses 32a ₁ , 32b ₁ for engaging the globe 50 and arc tube engaging holes 32a ₂ , 32b ₂ . Then, the ends of the arc tube 34 are penetrated through the holes 32a ₂ and 32b ₂ of the ceramic disks 32a and 32b, and the ends of the globe 50 are engaged with the engaging recesses 32a ₁ and 32b ₁ to form the ceramic disks 32a and 32b. An inorganic adhesive is loaded into the engaging portion between the globe 50 and the arc tube 34 to fix and integrate them, and the region S between the globe and the tube is sealed.

Further, the region 52 of the globe 50 corresponding to the closed glass bulb 34a, which is the heat source of the arc tube 34, is formed in an ellipsoidal shape larger than the diameter of the end of the globe and has a particularly high temperature. The tube area surrounding the closed glass bulb 34a is separated from the heat source, and the closed globe-tube area S is vacuumed to keep the surface temperature of the globe 50 low. .. Therefore, when the discharge bulb is turned on, the temperature rises due to the heat generation of the arc tube 34 and the sealing agent loaded in the engaging portion between the lamp body 10 and the transparent cover 18 or the silicon-based synthetic resin material in the lamp chamber (Si) jumps out, but since silicon (Si) cannot contact the arc tube 34 having a high surface temperature even though it contacts the globe 50 having a low surface temperature, the generation of SiO ₂ is suppressed and There is no possibility that the formed SiO ₂ will adhere to the arc tube 34. Therefore, there is no problem that the arc tube 34 is clouded white and the luminous efficiency is reduced. The inside and / or outside of the globe 50 is coated with an ultraviolet shielding film such as ZnO for blocking ultraviolet rays, and the durability of the ultraviolet shielding film tends to decrease at high temperatures. The vacuum state in the tube-to-tube region S is also effective in suppressing the deterioration of the durability of the ultraviolet shielding film. Reference numeral 54 is a pinch seal portion provided on the globe 50, and when the arc tube / groove combination A is assembled, a vertical tube as shown by reference numeral 53 in FIG. 3 projects from the position of the pinch seal portion 54. The region S between gloves and tubes is evacuated through the vertical tubes 53, and then the vertical tubes 53 are pinched off to form the region S between gloves and tubes in a vacuum atmosphere.

The arc tube / groove combination A is
The end side ceramic disc 32b has three rivets 42
Is fixedly supported on the front surface of the insulating base 40 by
It On the front surface of the insulating base 40, the base is fixed inside the base.
Fixed, three rivets 42 protruding forward are provided.
And the hole 32b in the rear end side ceramic disk 32b.
₃The rivet 42 through the
By plastically deforming outward, the peripheral edge of the hole is rivet 42.
It is fixed by crimping. Also, the circular pipe shaped part 3
4b_FourThe lead wire 37b derived from the insulating base 40
Through the front and rear through holes 43 formed in the
It is welded to the terminal 44 insert-molded into zero.
In addition, the circular pipe-shaped portion 34 that is the front end portion of the arc tube
b₃The lead wire 37a derived from
Bending of the lead wire 33a, which is the tip region of 33
Tip 33a₁It is spot welded to. Note that reference numeral 4
5 is an end integrated with the base end of the lead support 33
With the child, form the male connector 15 with the terminal 44.
From the lighting circuit housing unit 12 to the male connector 15 of
Male connector connected to outgoing output cord 16
14 is connected.

Reference numeral 46 is a focusing ring fixed to the peripheral edge of the insulating base 40. The focus ring 46, which is a reference contact portion when the discharge bulb 30 is positioned in the bulb insertion hole 23 of the reflector 22, and the insulating base 40.
Is the metal ring 4 on the mating surface of both members 46, 40.
7 has a structure in which it is slidable in the circumferential direction and the axial direction (Y direction shown in FIG. 3) with the interposition of 7. At the position, the metal ring 47 is heated by high frequency induction heating so that the mating surfaces of both members 40 and 46 are welded and integrated.

Further, the front end portion 5 of the ultraviolet shielding globe 50
0a is a region 5 corresponding to the discharge part of the arc tube 34.
The diameter is smaller than the diameter of No. ₂ and does not interfere with the reflected lights L ₂ and L _{3 on the} light reflection surface 22a formed around the bulb insertion hole 23 of the reflector 22. That is, the ultraviolet ray shielding globe 50 does not exist on the optical path of the lights L ₂ and L ₃ reflected by the reflector 22 and contributing to the light distribution. Therefore, as in the prior art (see FIG. 5), a part of the light reflected by the reflector and contributing to the light distribution is not vignetted to the globe 50, so that sufficient light is distributed to the hot zone region, A light distribution pattern of appropriate size and sufficient illuminance can be obtained. In order to prevent the vignetting of light for forming the hot zone, the diameter of the globe front end 50a is made smaller than the diameter of the region 52 corresponding to the discharge part 34a. , 32b to form an integrated arc tube / groove combination A, and an insulating base 4
This is the first shape that can be realized by using a structure in which the front end portion of the combined body A is supported by the lead support 33 protruding from 0. The light reflecting surface 22a for forming the hot zone
Although the lead support 33 is positioned on the optical path of the reflected light L ₃ at, the lead support 33 is thin, so there is no problem in light distribution.

Reference numeral 16 is a synthetic resin decorative plate disposed around the projection lens 26 of the light projection unit 20. The surface of the decorative plate is coated with silver to improve the appearance of the headlamp when it is not lit. .. FIG. 4 is a sectional view of an essential part of a vehicle headlamp that is a second embodiment of the present invention. Only a part of the structure of the discharge bulb is different from the above-mentioned embodiment,
Others are the same as those in the above-mentioned embodiment, and the same reference numerals are given to omit the duplicated description.

That is, although the front and rear ceramic disks 32a and 32b are different in shape from each other in the above embodiment, in this embodiment, the front and rear ceramic disks 32 are different from each other.
Since a and 32a have exactly the same shape, there is an advantage that the number of types of constituent parts can be reduced accordingly. Further, the rear end of the arc tube / groove combination B in which the arc tube 34 and the globe 50 are integrated via the ceramic disks 32a, 32a is engaged in the cylindrical portion 47 formed to project on the front surface of the insulating base 40. The structure is such that the arc tube / groove combination B is fixed to the insulating base 40 more easily than the caulking fixing shown in the first embodiment.

The terminal 45 penetrates the insulating base 40 and projects to the front of the base, and the lead wire 33a is spot-welded to the front projection of the terminal 45 so that the lead support 3 is formed.
3 and the structure of the lead support 33 is simplified as compared with the above-described embodiment. It should be noted that the ultraviolet shielding globe 50 and the ultraviolet shielding filter 27 in the above-described embodiments have a structure in which an ultraviolet shielding film is formed on the front surface or the back surface or both front and back surfaces of glass, but the globe and the filter themselves have an ultraviolet shielding function. It may be made of soda glass or hard glass. Further, the ultraviolet ray shielding filter 27 is not necessarily required to be provided.

Further, in the above-mentioned embodiment, the shade 25 is provided to cut off harmful light on the light distribution of the passing beam (sub beam), but the present invention is applied to the formation of the traveling beam (main beam). When applied to a headlamp, the shade 25 becomes unnecessary. Although the present invention has been described with reference to the projection type headlamp in the above embodiment, the present invention is not limited to the projection type.
It can also be applied to parabolic reflector headlamps.

[0022]

As is apparent from the above description, according to the automobile headlamp of the present invention, the arc tube and the cylindrical ultraviolet ray shielding globe surrounding the arc tube are integrated via the ceramic disk. Since the arc tube / grove combination that has been made into a structure is configured and the front end of this arc tube / grove combination is supported by the lead support protruding from the insulating base,
The front end portion of the ultraviolet shielding globe that surrounds the discharge lamp can be formed in a tapered shape that does not interfere with the light reflected by the reflector, the problem of light vignetting is solved, and light distribution with proper illuminance can be obtained. In addition, since the ultraviolet rays in the harmful wavelength range are cut off by the ultraviolet shielding gloves,
There is no effect on the human body or headlamp components.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an automobile headlamp according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a discharge bulb.

FIG. 3 is an enlarged vertical sectional view of a discharge bulb.

FIG. 4 is a longitudinal sectional view of a main part of an automobile headlamp according to a second embodiment of the present invention.

FIG. 5 is a vertical sectional view of a conventional automobile headlamp.

[Explanation of symbols]

10 Lamp Body 20 Light Projection Unit 22 Elliptical Reflector 22a Light Reflecting Surface Area for Hot Zone Formation 26 Projection Lens 30 Discharge Bulb 40 Insulating Base 33 Lead Support 34 Discharge Lamp 34a Discharge Section 34b ₁ and 34b ₂ Pinch Seal 37a, 37b Lead wire 50 Ultraviolet ray shielding globe 50a Tapered globe front end L ₂ , L ₃ Light for forming hot zone reflected by reflector

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location // F21M 3/05 B 9249-3K F21V 9/06 2113-3K

Claims (2)

[Claims] 1. An arc tube / globe in which front and rear end portions of an arc tube are fixedly held via a ceramic disk at front and rear opening ends of a reflector provided in a lamp body and a cylindrical ultraviolet shielding globe, respectively. And a discharge bulb in which a rear end of the arc tube / groove combination is fixedly supported by an insulating base and a front end is fixedly supported by a lead support protruding from the insulating base. A headlamp for an automobile, which is arranged in front of a bulb and which distributes light reflected by a reflector to the front, wherein the front end portion of the ultraviolet shielding globe is at the periphery of the bulb insertion hole of the reflector. A headlamp for an automobile, characterized in that it has a tapered shape that does not interfere with the light reflected by the light reflecting surface area. 2. The headlamp for an automobile according to claim 1, wherein the reflector has a substantially ellipsoidal shape, and the lens is a projection lens for projecting and distributing light guided from the reflector.