JPH04112401A - Projection type head lamp for car - Google Patents

Abstract

PURPOSE:To provide a projection type head lamp for car which gives a hot zone of proper light intensity by constructing a globe for shield against ultraviolet rays in a cylindrical form opened at the front, and installing an inner lens for shielding against ultraviolet rays between a discharge lamp and a projection lens. CONSTITUTION:A light projector unit 20 comprises a metal reflector 22 in an elliptical form, a discharge bulb 30 fitted in a bulb insert hole 23 formed at the rear top of this reflector, and a metal lens holder 24 at whose front a projection lens 26 is fixed and which is secured to the front opening of the reflector 22, wherein the three members are consolidated in a single piece structure. A globe 50 for shielding of ultraviolet rays is made cylindrical, and the beam of light emitted ahead from the front opening of the globe includes ultraviolet rays, but will get rid of those when passing through an inner lens 27 for ultraviolet rays which is located in the neighborhood of No.2 focal point F2 of the reflector 22, so that there is no fear of ill influencing on a human body, plastic lamp component parts, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a projection type headlamp for automobiles that reflects light from a light source with an elliptical reflector, converts the reflected light into parallel light with a projection lens, and projects the reflected light into parallel light. In particular, the present invention relates to a projection type headlamp for automobiles that uses a discharge lamp as a light source.

[Prior Art and Problems to be Solved by the Invention] Discharge lamps are increasingly being used as light sources for automobile headlamps because they have good luminous efficiency and color rendering properties, and have a long lifespan. Discharge lamps emit ultraviolet rays when they emit light, and this ultraviolet rays are harmful to the human body and may also denature the synthetic resin components inside the headlamp. It is surrounded by a glove to block harmful ultraviolet rays.

However, as shown in FIG.
This problem does not occur with headlamps of the type where the light emitted from the light source (emitted from The light emitted from discharge lamp 1) is attached to an elliptical glue lifter
3, the projection lens 6
In a headlamp that projects parallel light, the hot zone is divided into left and right halves, as shown by reference numeral 8 in Figure 8, and the luminous intensity in the central region (indicated by reference 9 in Figure 8) is insufficient. A problem arose.

Upon investigation by the inventors, it has been found that this is because a part of the light reflected by the flefter 3 (indicated by reference numeral Q in FIG. 7) is blocked by the tip of the ultraviolet shielding glove 1a. Therefore, the present invention was developed from the viewpoint that the ultraviolet shielding glove 1a should be shaped so as not to block the light reflected by the reflector 3 as much as possible.

The present invention was made in view of the above-mentioned problems.

The object of the present invention is to provide a projection type headlamp for automobiles that uses a discharge lamp as a light source and can provide a hot zone with appropriate luminous intensity.

[Means to solve the problem]

In order to achieve the above object, in the projection type headlamp for an automobile according to claim (1), in the lamp body.

an elliptical reflector, a discharge lamp as a light source placed at a first focal point of the ellipse reflector, an ultraviolet shielding glove surrounding the discharge lamp, and an ellipse reflector placed in front of the ellipse reflector. In a projection-type headlamp for an automobile, which is equipped with a light projection unit integrated with a projection lens that converts reflected light from a parallel beam into parallel light and projects it forward, the ultraviolet-ray shielding glove is shaped like a cylinder with an opening at the front. In addition, an inner lens for shielding ultraviolet rays is provided between the discharge lamp and the projection lens.

Further, in the automobile headlamp according to claim (2), the lamp body includes an elliptical reflector, a discharge lamp that is a light source disposed at a first focal position of the ellipse reflector, and a discharge lamp surrounding the discharge lamp. For automobiles, the light projection unit is provided with an integrated ultraviolet shielding glove and a projection lens that is placed in front of the elliptical reflector and converts the light reflected by the elliptical reflector into parallel light and projects it forward. In the projection type headlamp, the UV-shielding globe has a cylindrical shape with a front opening, and a UV-shielding film is formed on the outer surface of the discharge lamp facing the opening at the tip of the globe.

[Effect]

The reflected light on the hot zone light distribution light reflecting surface of the elliptical reflector is not blocked by the ultraviolet ray shielding glove, and a hot zone of appropriate size and luminous intensity can be obtained. In claim (1), the ultraviolet rays emitted from the opening at the tip of the ultraviolet ray shielding glove are blocked by the ultraviolet ray shielding inner lens provided in front of the discharge lamp. Further, in claim (2), the ultraviolet rays directed from the discharge lamp toward the opening at the tip of the globe are blocked by the ultraviolet shielding film formed on the outer surface of the discharge lamp when the ultraviolet rays are emitted from the discharge lamp.

〔Example〕

Next, an embodiment of the present invention will be described based on the drawings.

FIG. 1 shows one embodiment of the present invention, and is a longitudinal sectional view of a projection type headlamp for an automobile using a discharge lamp as a light source.

In this figure, numeral 10 is a container-shaped lamp body;
A light projection unit 20 is tiltably supported within the lamp body 10 by an aiming mechanism (not shown).

The light projection unit 20 includes an elliptical metal reflector 22, a discharge bulb 30 inserted into a bulb insertion hole 23 formed at the rear top of the reflector, and a projection lens 26 fixed to the front surface of the reflector. -22 has an integrated structure with a metal lens holder 24 attached to the front opening. Reference numeral 30a denotes a locking cap for fixing the discharge bulb 30 to the bulb insertion hole 23;
Reference numeral 26a designates an annular lens fixing frame that fixes the projection lens 26 to the lens holder 24 by caulking.

The discharge bulb 30 has a discharge lamp 34 mounted on a pair of lead supports 32a and 32b that protrude from the front of an insulating base 3.
The discharge portion 34a of the discharge lamp 34 is disposed at the first focal point F1 of the reflector 22. Further, a cylindrical ultraviolet shielding glove 50 surrounding the discharge lamp 34 is fixedly held on the front surface of the base 31 via a glove holding plate 40, and the discharge portion 34a is fixedly held on the front surface of the base 31.
It is designed to block harmful ultraviolet rays in the wavelength range emitted by the sun. Second focal point F2 of reflector 22
Nearby, there are provided a shade 25 for forming a clear cut integrated with the lens holder 24, and an inner lens 27 for shielding ultraviolet rays fixedly held on the lens holder 24 by a metal leaf spring member 27a. Then, the light emitted from the discharge section 34a of the discharge lamp 34 is reflected by the reflector 22, and after converging on the second focal point F2 of the reflector 22,
The projection lens 26 converts the light into parallel light and projects it forward. Note that the leaf spring member 27a is U-shaped, with both ends 27a
1 is held between the lens holder 24 and the flange 22, and the central region 27a of the plate spring member
2 is fastened to the shade 25 with a screw 27a. Reference numeral 24a denotes a pair of left and right horizontal ribs integrally formed on the inner surface of the lens holder.
A silicone rubber 24b is attached to the end of the reflector side and is in contact with the inner lens 27, and the inner lens 27 is pressed against the silicone rubber 24b and the upper end of the shade 25a by the spring force of the leaf spring member 27a. ing. Further, the lens holder 24 and the leaf spring member 27a are made of metal and have excellent heat resistance.

Further, the tip end 50a of the ultraviolet shielding glove 50 is positioned so as not to block the reflected light Q on the hot zone forming light reflecting surface 22a formed around the bulb insertion hole 25 of the reflector 22.

That is, the ultraviolet shielding glove 50 is placed on the optical path of the light Ω that is reflected by the reflector 22 and contributes to the light distribution in the hot zone.
does not exist. Therefore, unlike the conventional method (see Figure 7), part of the light that is reflected by the reflector and contributes to the light distribution in the hot zone is not blocked, so that sufficient light is distributed in the real zone area. As a result, a hot zone of appropriate size and sufficient luminosity can be obtained.

Further, the ultraviolet ray shielding glove 50 has a cylindrical shape, and the light emitted forward from the front opening of the glove includes ultraviolet rays. Since ultraviolet rays are blocked when they pass through the inner lens 27, there is no risk of adverse effects on the human body or the components of the lamp made of synthetic resin.

Reference numeral 12 denotes a lighting circuit housing unit that houses a lighting circuit (not shown) for a discharge bulb, and is integrated into an opening 11 formed at the rear top of the lamp body 10 via a cylindrical extension 13. The male connector 14 connected to the lead wire extending from the lighting circuit is connected to the insulating base 31.
It is connected to a male side connector 15 that is integrally formed on the back side of the . Note that the reference numeral 16 is a decorative plate made of synthetic resin arranged around the projection lens 26 of the light projection unit 20.
The surface is painted silver to improve the appearance when the headlights are not lit. Also, the code 18 is the lamp body 1
This is a lens that is assembled and integrated into the front opening of the lens.

Details of the discharge bulb 30 are shown in FIGS. 2 to 4, and the discharge lamp 34 has a circular pipe-shaped quartz glass tube pinched at one end and near the other end to form a discharge space. Pinch seal portions 34b1 and 34b having a rectangular cross section are provided at both ends of the sealed glass bulb 34a, which is an ellipsoidal discharge portion.
2, and a starting rare gas, mercury, and metal halide are sealed in the glass bulb 34a. Further, one pinch seal portion 34b2 is integrally formed with a circular pipe-shaped extension portion 34c that is not pinch sealed, and this extension portion 34c is held by a metal support 33b, which will be described later. Tungsten discharge electrodes 35a and 35b are arranged facing each other in the discharge space.
a, 35b are connected to molybdenum foils 36a, 36b sealed to the pinch seal parts 34b, 34b2, and lead wires 37a are connected from the ends of the pinch seal parts 34b, 34b2 to the molybdenum foils 36a, 36b, respectively. ,
37b is led out, and the lead wire 37b is inserted through the extension portion 34c and spot welded to the metal support 33b. The discharge lamp 34 is insert-molded into the insulating base 31 and supported at both ends by a pair of long and short lead supports 32a and 32b that protrude forward from the base via metal supports 33a and 33b.

The insulating base 31 is a disk-shaped molded body made of a synthetic shelving material such as PPS, and a lead support 3 is provided on the back side of the base 31.
Connector male terminals 32c and 32d, which are integrally welded to 2a and 32b, respectively, protrude. Terminals 32c, 32
d is surrounded by a partition wall 31a extending into a rectangular cylinder shape to prevent discharge between both terminals 32c and 32d. Further, the integrated terminal 32c and lead support 32a and the integrated terminal 32d and lead support 32b are integrated into the insulating base 31 by insert molding. A front and rear through hole 31b is formed in the base region between the lead supports 32a and 32b by molding, and thereby the base 3
The dielectric strength of 1 is increased. This hole 31b extends across between the terminal 32c and the terminal 32d, and
The presence of the air layer (an air layer region with lower insulation properties than the base material) C between the holes 31b and 32d is considered to reduce the dielectric strength of the base. However, when the base 31 is molded, the hole forming wall surface is pressed tightly against the mold, so the material density around the hole becomes high, and the material density around the hole is higher than the decrease in dielectric strength due to the air layer C. The increase in dielectric strength associated with
As a result, the dielectric strength is greater than in the case where the through hole 31b is not formed, and discharge is less likely to occur between the terminals 32c and 32d. Further, this hole 31b communicates with the inside of the glove 50 via a front and back through hole 40a formed in a glove holding plate 40, which will be described later. Heat dissipation is promoted. A pair of rivets 42 and 42, which are glove fixing fittings integrated into the base by insert molding, protrude from the front surface of the base 31, and the ceramic disc-shaped glove holding plate 40 is fixed to the front surface of the base by the rivets 42. Retained.

A pair of lead support insertion holes 43 and 44 are formed in the glove holding plate 4o, and a pair of rivet insertion holes 46 and 46 are further formed on both sides of the insertion hole 44.

The lead supports 32a and 32b are made to protrude from the lead support insertion holes 43 and 44, and the peripheral edges of the rivet insertion holes are caulked and fixed by rivets 42.

A fixture 47b, which is a metal fitting for fixing the holding plate, is attached to the lead support 32b, and presses and fixes the peripheral edge of the lead support insertion hole to the base side. Reference numeral 48 denotes an insulating cylindrical body made of ceramic for preventing discharge that is fitted around the outer periphery of the covering portion 31c of the lead support 32a, and a fixture 47a having the same structure as the fixture 47b is also installed between this insulating cylindrical body 48 and the lead support 32a. The insulating cylindrical body 48 is fixedly held on the lead support 32a.

The metal support 33b is made by forming a belt-shaped metal plate of a constant width into a circular pipe shape to form an arc-shaped lamp gripping part 33b. The extending portion 34c is connected to the lamp gripping portion 33.
A flange portion 33b2 is spot welded to the tip of the lead support 32b while it is being held by the b-handle. For this reason, sliding the discharge lamp 34 in the axial direction (horizontal direction in FIG.
It is also easy to slide the discharge part of the discharge lamp 34 with respect to the reflector 22.

Like the metal support 33b, the metal support 33a that supports the front end of the discharge lamp 34 is formed from a band-shaped metal plate with a constant width, and one end is caulked and fixed to the tip of the lead support 32a, and spot welded. The other end is folded back to sandwich the front end wire 37a and spot welded.

The UV shielding glove 50 is made of transparent glass in the shape of a cylindrical cup with a closed front end, and is inorganic adhesive bonded to the glove engaging groove 41 of the ceramic glove holding plate 40 fixed to the base 31 with rivets 42. Agent 41a
The base end on the glove opening side is firmly adhered. The outer surface of the glove is coated with an ultraviolet shielding film 5 made of ZnO.
Therefore, when the globe 50 is fixedly held on the base 31, the discharge lamp 34
The ultraviolet shielding film 54 that surrounds the globe 50 absorbs the ultraviolet rays generated at the same time as the discharge lamp 34 emits light, and only the visible light from which the ultraviolet rays have been cut is emitted to the outside of the globe 50 . In addition, the transmittance of ultraviolet rays shorter than 370 nm is O.
In order to achieve this, a film thickness of 1.6 μm or more is required, and from the perspective of preventing peeling, a film thickness of 5 μm or less is desirable.

In addition, the wavelength range of ultraviolet rays that can be cut varies depending on the temperature around the glove (at high temperatures, the wavelength range that is cut shifts to the longer wavelength side), so at least the wavelength range of 370 to 3
The film thickness is said to be such that it can block ultraviolet rays of 80 nm or less. Note that the ultraviolet shielding film can be formed by dipping, vapor deposition, spraying, or other coating methods. If the film thickness is adjusted by dipping,
This can be done by changing the rate at which the glove is pulled up from the immersed state, or by changing the number of times of dipping. Further, as another method for adjusting the film thickness, the film thickness can be increased by increasing the number of times of vapor deposition, spraying, etc. Also, compared to the previous proposal (see Figures 6 and 7) in which an ultraviolet shielding film was formed on a cup-shaped glass tube with a closed tip, this example uses a cylindrical glass tube with an open tip. The ultraviolet shielding film 54 may be formed on the inside or outside or on both the inside and outside of the UV shielding film 54.
is extremely easy to form.

The inner lens 27 is also formed by forming an ultraviolet ray shielding film such as ZnO on the front or back surface or both front and back surfaces of a flat glass plate, and the method of forming the ultraviolet ray shielding film is the same as that of the ultraviolet ray shielding glove.

Reference numeral 30a is a protrusion for positioning the discharge bulb back and forth, which is provided on the front surface of the peripheral edge of the insulating base 31. This protrusion 30a comes into contact with the wall surface of the bulb insertion hole (not shown), and the bulb is aligned in the front and rear direction (front and back of the optical axis). direction).

Reference numeral 30b is a notch for positioning in the circumferential direction formed on the peripheral edge of the insulating base 31. When the discharge bulb is inserted into the valve insertion hole (not shown), the protrusion on the side of the valve insertion hole is inserted into the notch 30b. is engaged to circumferentially position the valve.

In addition, in the above-described embodiment, the ultraviolet shielding glove 50 is #! Although described as having a structure in which the globe 50 is fixedly held on the edge base 31 and integrated with the discharge bulb 30, the globe 50 is separate from the discharge bulb 30, and for example, the base end of the globe is connected to the bulb insertion hole 23. It may have a structure in which it is engaged and fixed to.

In addition, instead of the inner lens 27 shown in the above-described embodiment, as shown in FIG. It may also be formed. The formation limit 55a of the light-shielding coating film 55 on the discharge part side is set to a position where the discharge part 34a and the ultraviolet-ray shielding glove tip 50a are connected.

Note that the UV-shielding glove 50 and the UV-shielding inner lens 27 of the above-mentioned embodiments have a structure in which a UV-shielding film is formed on the surface of glass. Good as an inner lens.

〔Effect of the invention〕

As is clear from the above description, according to the projection type headlamp for automobiles according to the present invention, the reflected light from the hot zone light distribution light reflecting surface of the reflector is not blocked by the ultraviolet ray shielding glove, A hot zone of high luminosity is obtained. In addition, the ultraviolet rays emitted from the opening at the tip of the ultraviolet ray shielding glove are cut by the inner lens for ultraviolet ray shielding, or the ultraviolet rays directed toward the opening at the tip of the ultraviolet ray shielding glove are formed in the discharge lamp when they are emitted from the discharge lamp. The ultraviolet rays are blocked by the ultraviolet shielding film, so
There are no defects that are harmful to the human body or other headlamp components.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a projection type headlamp for an automobile which is an embodiment of the present invention, Fig. 2 is a partially cutaway perspective view of a discharge bulb, and Fig. 3 is a longitudinal sectional view of the same bulb. , FIG. 4 is a cross-sectional view of the same valve (a cross-sectional view along line IV-IV shown in FIG. 3), FIG. 5 is a cross-sectional view of main parts of another embodiment of the present invention,
Figure 6 is a schematic diagram of a conventional reflective headlamp for automobiles.
FIG. 7 is a schematic diagram of the previously proposed projection type headlamp for automobiles that uses a discharge lamp as a light source, and FIG. 8 is a diagram showing the hot zone on the light distribution screen of the headlamp shown in FIG. 7. . 10... Lamp body. 20...Light projection unit. 22... Elliptical reflector (reflector), 26... Projection lens, 27... Inner lens for ultraviolet shielding, 30... Discharge bulb, 34... Discharge lamp as a light source, 50... Ultraviolet rays Shielding gloves. 50a... Glove tip, 54... Ultraviolet shielding film, 55... Light blocking coating film which is an ultraviolet shielding film.

Claims (2)

[Claims] (1) Inside the lamp body, an elliptical reflector, a discharge lamp which is a light source placed at the first focal point of the ellipse reflector, an ultraviolet shielding glove surrounding the discharge lamp, and an elliptical reflector located at the first focal point of the ellipse reflector. A projection type headlamp for an automobile is provided with a light projection unit integrated with a projection lens that is placed in front and converts light reflected by an elliptical mirror into parallel light and projects it forward, wherein the ultraviolet shielding glove is A projection type headlamp for an automobile, characterized in that it has a cylindrical shape with an opening at the front, and an inner lens for shielding ultraviolet rays is provided between the discharge lamp and the projection lens. (2) Inside the lamp body, an elliptical reflector, a discharge lamp that is a light source placed at the first focal point of the ellipse reflector, an ultraviolet shielding glove surrounding the discharge lamp, and A projection type headlamp for an automobile is provided with a light projection unit integrated with a projection lens that is placed in front and converts light reflected by an elliptical mirror into parallel light and projects it forward, wherein the ultraviolet shielding glove is A projection type headlamp for an automobile, characterized in that the discharge lamp has a cylindrical shape with a front opening, and an ultraviolet shielding film is formed on the outer surface of the discharge lamp facing the opening at the tip of the globe.