JP3004783B2 - Automotive headlamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile 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 having a pair of pinch seal portions 1b and 1c extending forward and backward from a closed glass bulb 1a.
A lead wire 2 (2a, 2b) connected to a counter electrode in the closed glass bulb 1a is led out from the end of 1c. The lead wire 2 (2a, 5a, 5b) is fixed to the metal support 5 (5a, 5b) welded to a pair of long and short lead supports 4 (4a, 4b) projecting forward of the lamp base 3.
2b) is welded and fixed to constitute a discharge lamp device in which the arc tube 1 is supported at both ends.

Since this discharge lamp device has good luminous efficiency and good color rendering properties, studies have been made to use it as a bulb for an automobile headlamp. Since ultraviolet rays in a harmful wavelength range are included in the light, it is necessary to cut off the ultraviolet rays in the harmful wavelength range. As a means for cutting the ultraviolet rays, as shown in the figure, there is a structure in which an ultraviolet 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, this discharge lamp device is used as a bulb of a projection type head run in which reflected light from a substantially elliptical reflector 7 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 portion (sealed glass bulb) 1a of the arc tube provided at the first focal position of the reflector 7 is reflected by the reflector 7 as shown by the arrow in FIG. Then, the light passes through the second focal point on the optical axis and is projected and distributed forward by the projection lens 8 to form a predetermined light distribution pattern. However part of the reflected light by the reflector 7, in particular, light reflecting in the tip of the optical L ₁ UV shielding globe 6 reflected by the light reflecting surface regions 7a around bulb insertion hole, absorbed, refracted, etc. (hereinafter , Which is called vignetting of light), the illuminance at the central part of the light distribution pattern is lowered, and there is a problem that the light distribution is not preferable. Reference numeral 6a is light L ₁
Indicates a vignetting site. If the length of the arc tube 1 is reduced (the length of the pinch seal portions 1b and 1c is reduced), the front and rear length of the globe 6 can also be reduced, and this problem (vignetting of reflected light by the reflector on the glove) is solved. However, it is difficult to shorten the length of the arc tube 1 in order to seal the lead wire and prevent leakage of the sealing gas in the sealed glass bulb. Although the diameter of the globe 6 may be reduced, the diameter of the globe 6 cannot be sufficiently reduced due to the presence of the lead supports 4a and 4b for supporting the arc tube 1, and vignetting of light cannot be prevented.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems of the prior art, and has as its object to provide a discharge lamp provided with an ultraviolet shielding glove 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 open ends of a cylindrical ultraviolet shielding glove are provided. The front and rear ends of the arc tube are fixedly held via ceramic discs at the portions, respectively, to form an arc tube / globe assembly, and the rear end of the arc tube / globe assembly is fixedly supported by the insulating base and A vehicle head comprising: a discharge bulb fixedly supported by a lead support having a front end protruding from an insulating base; and a lens disposed in front of the discharge bulb and distributing light reflected by a reflector forward. A lamp, wherein the front end of the ultraviolet shielding globe is reflected by a light reflecting surface area around a bulb insertion hole of a reflector. It is obtained so as to form a tapered shape that does not interfere with the light.

According to a second aspect, the first aspect is applied to a projection type headlamp provided with a reflector having a substantially elliptical shape and a projection lens.

[0008]

According to the first aspect of the present invention, the ultraviolet shielding glove is formed in a cylindrical shape, and the arc tube and the ultraviolet shielding glove surrounding the outer tube are integrated via a ceramic disk to constitute an arc tube / glove combined body. Since the arc tube / globe combination is supported by the lead support projecting forward from the insulating base, the lead support does not hinder the tapered tip of the globe. Further, since the light reflected on the light reflecting surface area around the bulb insertion hole of the reflector is not vignetted by the globe, an appropriate light distribution pattern can be obtained.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a longitudinal 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. 2 is an enlarged vertical sectional view of a discharge bulb.

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

In the discharge bulb 30, an arc tube / globe combination A in which an arc tube 34 and a globe 50 surrounding the arc tube 34 for shielding ultraviolet rays are integrated via ceramic disks 32a and 32b is made of synthetic resin. of the insulative base 40 and a metal lead support 33 by the structure which is integrated is supported at both ends, the discharge portion 34a of the arc tube 34 is positioned at the first focal point position F ₁ of the reflector 22. The second focus position F ₂ the vicinity of the reflector 22, the shade 2 of light distribution patterns formed for passing integrated into the lens holder 24
5, and a metal leaf spring member 27a
A UV-shielding filter 27 fixed and held by is provided. The discharge part 34 of the arc tube 34
The light emission a is reflected by the reflector 22, converges on the second focal point F ₂ of the reflector 22, is converted into parallel light by the projection lens 26, and is projected forward, but the light passes through the ultraviolet shielding globe 50 and the filter 27. UV rays are cut twice when performing.

The details of the discharge bulb 30 are shown in FIGS.
Is shown in The arc tube 34 is formed 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 elliptical discharge portion forming a discharge space. With a structure formed integrally, a starting rare gas, mercury and a metal halide are sealed in the glass bulb 34a. Pinch seal portions 34b _1, 34b from ₂ is a non-pinch seal portion circular pipe-shaped portion 34b _3, 34b ₄ are formed at both ends of the arc tube 34 extends. Discharge electrodes 35a of within the closed glass bulb 34a tungsten, 35b is arranged to face the discharge electrodes 35a, 35b is pinch-sealed portion 34b _1, 34b ₂ on the sealed molybdenum foils 36a,
Connected to 36b, the pinch seal portion 34b _1, 34b ₂ of the molybdenum foil 36a from the end, respectively connected to leads 37a to 36b, 37b is derived, leads 37
a, respectively 37b circular pipe-shaped portion 34b _3, 34b ₄
And extends to the outside.

The ultraviolet shielding glove 50 surrounding the arc tube 34 is a glass tube having a slightly shorter length than the arc tube 34 and having an outer diameter larger than the outer diameter of the arc tube 34 and having open ends at both ends. Ceramic discs 32a and 32 engaged with the openings at both ends
An arc tube / globe combination A is formed by being integrated with the arc tube 34 via b. That ceramic disk 32a, the recess 32a ₁ for engagement with the globe 50 to 32 b, 32 b ₁ and the arc tube engaging hole 32a _2, 32b ₂ are provided. Then, the ends of the arc tube 34 are passed 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 , respectively. An inorganic adhesive is loaded into the engagement portion between the globe 50 and the arc tube 34, and they are fixed and integrated, and the region S between the glove and tube is sealed.

Further, a region 52 of the globe 50 corresponding to the closed glass sphere 34a, which is a heat source of the arc tube 34, is formed in an elliptical shape larger than the diameter of the end of the globe, and becomes particularly hot. The tube area surrounding the sealed glass bulb 34a is separated from the heat source, and the sealed glove-tube area S is evacuated to keep the surface temperature of the globe 50 low. . For this reason, when the discharge bulb is turned on, the temperature rise due to the heat generated by the arc tube 34 causes the sealant loaded in the engagement portion between the lamp body 10 and the transparent cover 18 and the silicon-based synthetic resin material in the lamp chamber space to become silicon. (Si) but pops be in contact with silicon (Si) is lower glove 50 of the surface temperature, can not contact the high arc tube 34 of the surface temperature, with formation of SiO ₂ is suppressed, generation There is no possibility that the SiO ₂ thus deposited adheres 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 glove 50 is coated with an ultraviolet shielding film for cutting ultraviolet light such as ZnO, and the durability of the ultraviolet shielding film tends to decrease at high temperatures. Making the inter-tube region S in a vacuum state is also effective in suppressing a decrease in the durability of the ultraviolet shielding film. Reference numeral 54 denotes a pinch seal portion provided on the glove 50. When the arc tube / glove combination A is assembled, a vertical tube as shown by reference numeral 53 in FIG. The region S between gloves and tubes is evacuated via the vertical tube 53, and then the vertical tube 53 is pinched off to form the region S between gloves and tubes in a vacuum atmosphere.

The arc tube / globe combination A is
The end side ceramic disk 32b has three rivets 42
Is fixedly supported on the front surface of the insulating base 40.
You. On the front surface of the insulating base 40, the base is fixed in the base.
And three rivets 42 projecting forward are provided.
Hole 32b of the rear end side ceramic disk 32b.
_ThreeThrough the rivet 42 and insert the rivet tip in the radial direction.
By plastically deforming outward, the periphery of the hole is
It is fixed by caulking. In addition, circular pipe shape part 3
4b_FourLead 37b derived from the insulating base 40
Through the front and rear through holes 43 formed in the insulating base 4
0 is welded to the terminal 44 which is insert-molded.
Further, a circular pipe-shaped portion 34 which is a front end portion of the arc tube.
b_ThreeLead wire 37a is lead support
The lead wire 33a, which is the tip region of 33, bends
Tip part 33a₁Spot welded. Note 4
5 is an end integrated with the base end of the lead support 33
A male connector 15 together with the terminal 44
From the lighting circuit housing unit 12 to the male connector 15
Male connector connected to output cord 16
14 are connected.

Reference numeral 46 denotes a focus ring fixed to the peripheral portion of the insulating base 40. The focus ring 46 and the insulating base 40, which are reference contact portions when positioning the discharge bulb 30 in the bulb insertion hole 23 of the reflector 22,
Means that the metal ring 4
7 is interposed so as to be relatively slidable in the circumferential direction and the axial direction (the Y direction shown in FIG. 3). At the position, the metal ring 47 is heated by high-frequency induction heating so that the mating surfaces of the two members 40 and 46 are welded and integrated.

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

Reference numeral 16 denotes a decorative board made of a synthetic resin disposed around the projection lens 26 of the light projection unit 20, and its surface is coated with silver to improve the appearance when the headlamp is not lit. . FIG. 4 is a sectional view of a main part of an automotive headlamp according to a second embodiment of the present invention. Only a part of the structure of the discharge bulb is different from the above-described embodiment,
The other parts are the same as those of the above-described embodiment, and the same reference numerals are given, and the duplicated description will be omitted.

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

Further, the terminal 45 penetrates the insulating base 40 and projects forward of the base.
3 and the structure of the lead support 33 is simplified as compared with the embodiment described above. The ultraviolet shielding globe 50 and the ultraviolet shielding filter 27 in the above-described embodiment have a structure in which an ultraviolet shielding film is formed on the front surface, the back surface, or both the front and back surfaces of the glass. You may make it comprise soda glass or hard glass. Further, the ultraviolet shielding filter 27 is not necessarily provided.

In the above-described embodiment, the shade 25 is provided to cut off harmful light on the light distribution of the passing beam (sub beam). However, the present invention is applied to forming a traveling beam (main beam). When applied to a headlamp, the shade 25 becomes unnecessary. Further, in the above-described embodiment, the present invention has been described by taking a projection type headlamp as an example, but the present invention is not limited to a projection type headlamp,
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 shielding globe surrounding the arc tube are integrated via the ceramic disk. Since the arc tube / globe combined body is configured and the front end of the arc tube / glove combined body is supported by the lead support projecting from the insulating base,
The front end of the ultraviolet shielding globe surrounding the discharge lamp can be formed into a tapered shape that does not interfere with the light reflected by the reflector, so that the problem of vignetting of light is eliminated, and light distribution with an appropriate illuminance can be obtained. In addition, the light emission of the discharge part is cut off ultraviolet rays in the harmful wavelength range by the ultraviolet shielding glove,
There is no effect on the human body and headlamp components.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an automotive 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 automotive headlamp according to a second embodiment of the present invention.

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

[Explanation of symbols]

10 lamp body 20 to an optical projection unit 22 elliptical reflector (reflector) 22a hot zone light reflecting surface area 26 a projection lens for forming 30 discharge bulb 40 insulating base 33 lead support 34 discharge lamps 34a discharge portion 34b _1, 34b ₂ pinch seal part 37a, 37b lead wire 50 Grove front end L ₂ of the ultraviolet shielding globe 50a tapered, L ₃ light for hot zone forming reflected by the reflector

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H01J61 / 88 H01J61 / 88B (56) References JP-A-3-141501 (JP, A) JP-A-3-163744 ( JP, A) JP-A-2-165501 (JP, A) JP-A-2-31011 (JP, U) JP-A-60-131957 (JP, U) JP-A-4-21004 (JP, U) JP Hei 4-12204 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F21M 3/02 F21M 3/05 F21V 9/06 H01J 61/32 H01J 61/34 H01J 61/88

Claims (2)

(57) [Claims] An arc tube glove having a reflector provided in a lamp body and front and rear ends of an arc tube fixedly held via ceramic discs at front and rear open ends of a cylindrical ultraviolet shielding glove, respectively. A discharge bulb having a combined structure, a rear end portion of the combined arc tube / glove assembly fixedly supported by an insulating base, and a front end portion fixedly supported by a lead support projecting from the insulating base; A lens that is disposed in front of the bulb and distributes the light reflected by the reflector forward, wherein the front end of the ultraviolet shielding glove is provided around the bulb insertion hole of the reflector. An automobile headlamp having a tapered shape that does not interfere with light reflected by a light reflecting surface area. 2. The automotive headlamp according to claim 1, wherein the reflector has a substantially elliptical shape, and the lens is a projection lens that projects and distributes light guided from the reflector.