EP0992738B1 - Vehicle headlamp with double-walled shade - Google Patents

Description

The invention relates to a headlamp for vehicles with the features according to the preamble of claim 1.

Such a headlamp for vehicles is known from DE 195 14 085 A1. The headlight has a cup-shaped housing made of plastic, which is closed on its front by a lens. In the housing interior, a plastic existing, cup-shaped reflector is arranged. In the apex region of the reflector, an opening for receiving a light bulb is introduced. The bulb dips with its glass bulb in a cup-shaped aperture. As the bottom of the cup-shaped aperture is a lid which is connected via a bending tab integrally with the peripheral side wall of the panel. The lid adjoins with its outer edge portion of the lens facing the outer edge of the side wall. The panel is made of sheet metal and in practice is usually made of sheet steel, so that the panel withstands the high heat load through the bulb. The cup-shaped panel is connected via three arm-shaped support elements with the reflector. The side wall of the panel is punched out of sheet metal and rolled into a hollow body and has a seam formed by blunt, juxtaposed edges. The disadvantage here is that the interior of the headlamp appears inhomogeneous because of the existing sheet steel panel in an optically clear lens. In the case of a cover made of sheet steel and chrome-plated on the outside, the chromium plating turns on when the heat load is high.

From GB-A-1 301 768 a headlamp for vehicles is known in which a diaphragm arranged between a reflector and a lens has a double-walled side wall. The outer wall part of the double-walled side wall is connected via two support elements to a reflector, wherein the inner wall part is connected via a support element near the reflector with the support elements of the outer wall part and is designed substantially smaller than the outer wall part. Therefore, there is an air layer between the two wall parts and the wall parts are interconnected only via the support elements. It is disadvantageous that both the outer and the inner wall part are held on support elements and thus both wall parts must consist of a dimensionally stable heavy material. Furthermore, because of the air layer between the wall parts, the light rays coming directly from the light source exiting from the light source and reflected by the reflector strike the outer edge region of the outer wall part, through which a chromium plating on the outside of the outer wall part can start in color.

In the known from US-A-5 567 033 headlights for vehicles, a single-walled cup-shaped aperture has a bottom which adjoins with its free edge portion of a circumferential side wall of the diaphragm, wherein the bottom and the side wall of the cup-shaped aperture consist of the same metal sheet ,

In the case of the headlights disclosed in DE 197 53 973 A1 and DE 196 54 225 A1, the cover may be made of a different material than the side wall of the panel, but the outer edge section of the peripheral side wall of the cup-shaped panel is disturbingly visible from the outside.

The object of the invention is to improve the headlamp described in the preamble of claim 1 such that the entire outer side of a double-walled side wall having cup-shaped aperture of an outer bare surface having and easily deformable sheet is determined and still for the cup-shaped aperture high heat resistance and dimensional stability is given. This object is achieved according to the invention by the features of the characterizing part of claim 1. As a result, the entire outer side of the diaphragm can be formed by a metal sheet, which after molding has a smooth outer side, does not have to contribute to the dimensional stability of the cup-shaped diaphragm and in which permanent tarnishing on the smooth outer side of the diaphragm occur only at temperatures which are higher than on chromed sheet steel. As a metal sheet for the aperture is particularly suitable a light metal sheet with a shiny silver-colored surface, which serves as the outside of the panel. The light metal sheet is advantageously made of aluminum or an aluminum alloy, wherein the shiny silver surface is protected by a film. The glossy surface forms the outside of the cup-shaped aperture. After forming the outer wall portion and the bottom of the panel, the film is first removed. This will not damage the outside of the bezel during molding.

A very deep design of the cup-shaped aperture is possible if the outer and inner circumferential wall portion of the side wall in each case a seam which extends from the outer rim facing the reflector to the outer rim facing the lens. In this case, the outer wall part must not be deep-drawn, but can be rolled. During deep drawing, an undesirable matt surface is formed on the outside of the outer wall part. By rolling the smooth surface of the outer wall portion is maintained even if the circumferential side wall of the cup-shaped aperture is almost cylindrical. The aperture is very small in a cylindrical shape. As a result, the optically effective reflection surface of the reflector in the region of its apex can be as large as possible. The dimensional stability of the diaphragm is particularly great when the inner and outer wall part is frustoconical. The panel has a homogeneous appearance from the outside, when the inner and outer wall part has a common edge. In this case, only the inner wall part of the side wall is used for shading of light rays emerging directly from the light source. In this context, it is advantageous if the inner wall part consists of sheet steel and has a matte inner surface. The matt inner surface can be formed by a black finish. As a result, a high light absorption is given, and thus no disturbing light rays caused by reflection within the diaphragm. For the panel is given a high dimensional stability, since it is made of sheet steel. When using a lamp whose glass bulb has a blackened cap at the free end, the bottom of the panel must not be double-walled, since the cap directly shields light rays emerging from the light source from the ground.

Furthermore, it is advantageous if the support element of the panel is double-walled and each part of the support element is integrally connected to one of the seam delimiting edges of the inner wall part, wherein the support member passes through a slot of the outer wall portion and the slot laterally only to the reflector is open. The outer wall part is firmly connected to portions of its outer edges by small indentations with the inner wall part.

Furthermore, it is advantageous if the outer wall part of the double-walled side wall, in a portion in which the edges of a seam of the outer wall part abut each other, is non-detachably connected to each other.

• Figur 1 in einer Teilansicht einen vertikalen Mittelschnitt eines Scheinwerfers für Fahrzeuge mit einer einer Lichtquelle zugeordneten becherförmigen Blende;
• Figur 2 in einer Seitenansicht drei Bauteile der becherförmigen Blende vor dem Zusammenbau;
• Figur 3 eine Ansicht aus Richtung x in Figur 1 auf die becherförmige Blende;
• Figur 4 eine Ansicht aus Richtung y auf die becherförmige Blende;
• Figur 5 eine Abwicklung einer inneren Seitenwand der becherförmigen Blende mit einem an das innere Wandteil angeformten Tragelement der Blende;
• Figur 6 eine Abwicklung des äußeren Wandteils der becherförmigen Blende und
• Figur 7 eine Abwicklung des äußeren Wandteils und des Bodens einer anderen becherförmigen Blende, wobei der Boden über eine Biegelasche mit dem äußeren Wandteil verbunden ist.

An embodiment of the invention is shown in the drawing, in fact show

• Figure 1 is a partial sectional view of a vertical center section of a headlamp for vehicles with a cup-shaped aperture associated with a light source;
• Figure 2 in a side view three components of the cup-shaped aperture before assembly;
• Figure 3 is a view from direction x in Figure 1 on the cup-shaped aperture;
• Figure 4 is a view from direction y on the cup-shaped aperture;
• Figure 5 shows a development of an inner side wall of the cup-shaped aperture with an integrally formed on the inner wall part supporting element of the aperture;
• Figure 6 shows a development of the outer wall portion of the cup-shaped aperture and
• Figure 7 shows a development of the outer wall portion and the bottom of another cup-shaped aperture, wherein the bottom is connected via a bending tab with the outer wall portion.

The headlight has an outer housing made of plastic, which is closed by a largely optic-free lens (not shown). In the interior of the outer housing, at least one consisting of plastic, shell-shaped reflector (1) is arranged. In the reflector (1) an opening (17) for receiving a light source (3) is introduced in the region of its apex. As the light source (3) is an incandescent lamp which is inserted with its glass bulb (18) ahead through the opening (17) of the reflector (1) until the incandescent lamp with its plate-shaped base (19) at the outer edge region of the opening (17) is applied. The base (19) is through a holding device, not shown, held on the back of the reflector (1). The incandescent lamp has an incandescent filament, which is arranged in a focal region of the dish-shaped reflector (1). The glass bulb of the incandescent lamp has at its front free end portion a blackened cap (20) to shield directly from the light source (3) emerging light rays from the back. So that front edge portions of the reflector (1) are shielded from light rays which emerge directly from the light source (3), the glass bulb (18) with its free end dips into a cup-shaped diaphragm (2), which is supported by a support element (6). connected to the reflector (1).

The cup-shaped panel (2) has circumferentially a double-walled side wall (5) and a bottom (4), which is formed by a lid. The inner wall part (10) of the double-walled side wall (5) consists of a steel sheet whose inside is painted black. The black coating serves to absorb the light rays of the light source (3) which occur on the inside of the inner wall part (10). In Figure 5, the inner wall portion (10) is shown unwound and has at its opposite edges (14) each have a support arm, which is doubled the support element (6). After rolling the inner wall part (10), the edges (14) delimit a seam (16) which also extends between the two support arms of the doubled support element (6). On one of the two support arms of the support element (6) retaining lugs (21) are laterally formed, which are bent after the duplication of the support arms to the adjacent support arm around and thus hold together both support arms of the support element (6). In Figure 6, the outer wall portion (9) of the double-walled side wall (5) of the cup-shaped aperture (2) is shown.

The outer wall part (9) and the serving as a lid bottom (4) of the diaphragm (2) according to Figures 2 and 6 and 7 are formed from a light metal sheet, the outside of the cup-shaped aperture (2) forming surface high gloss and silver is. The high-gloss surface is protected by a peel-off film. The film is pulled off only after the molding of the outer wall part (9) and the bottom (4). The outer wall part (9) is rolled as well as the inner wall part (10) and lies flat against the inner Wall part (10). The outer wall part (9) has retaining lugs (21) on the edge (7) facing the reflector (1), which are bent around the outer edge (7) of the inner wall part (10) according to FIG. 5 and the outer wall part (9 ) on the inner wall part (10). The outer wall part (9) is held at its front edge (12) by indentations (not shown) which engage in the surface of the inner wall part (10) on the inner wall part (10). At the front edge (12), the inner and outer wall part (10 and 9) circumferentially on a step in which a lateral edge portion (8) of the bottom (4) is arranged. The lateral edge portion (8) extends with its outer side flush with the outside of the adjacent outer wall part (9). The bottom (4) serving lid is also held captive by not shown indentations on the outer wall part (9). The inner and outer wall part (10 and 9) have circumferentially on a common edge (7). In this case, only the edge (7) of the inner wall part (10) is used for shadowing of light rays emerging directly from the light source (3). The bottom (4) of the cup-shaped aperture (2) does not have to be double-walled, like its side wall (5), because of the blackened cap (20) of the glass bulb (18) of the light source (3) the bottom opposite directly from the light source (3 ) emerging light rays is shielded.

The unwinding shown in FIG. 7 is the outer wall part (9) and the bottom (4) of the cup-shaped panel (3). Here, the bottom (4) via a bending tab (13) is integrally connected to the outer wall part (9).

LIST OF REFERENCE NUMBERS Headlights for vehicles

1

reflector

2

Cover .

3

light source

4

ground

5

Side wall

6

supporting member

7

outer edge

8th

free edge section

9

outer wall part

10

inner wall part

11

seam

12

front edge

13

bending lug

14

margins

15

slot

16

seam

17

opening

18

flask

19

base

20

cap

21

holding flag

22

depression

Claims (10)

1. Headlamp for vehicles, having a beaker-shaped shade (2) arranged between a reflector (1) and a lamp screen, said shade serving both to shade off light rays emerging directly from a light source (3), as well as to cover the light source (3) and the base (4) of said shade being a cover connected to its peripheral side wall (5), and having at least one support element (6), which connects the beaker-shaped shade (2) to the reflector (1), wherein the beaker-shaped shade (2) has a peripheral double-layered side wall (5) extending as far as its outer free edge, characterised in that the outer wall portion (9) of the double side wall (5) lies and is held against the inner wall portion (10) which is connected by means of the support element (6) to the reflector (1), and the cover of the shade (2) serving as the base (4) adjoins the double-layered side wall (5) with its free edge section (8) on the outer wall portion (9), wherein the cover formed by the base (4) and the outer wall portion (9) of the side wall (5) comprise the same metal sheet.
2. Headlamp for vehicles according to claim 1, characterised in that at least the outer peripheral wall portion (9) of the side wall (5) has a seam (11), which runs from the outer edge (7) facing towards the reflector (1) to the outer edge (12) facing towards the lamp screen.
3. Headlamp for vehicles according to claim 1 or 2, characterised in that the inner and outer wall portion (10 and 9) are made in the form of a truncated cone.
4. Headlamp for vehicles according to one of the claims 1 to 3, characterised in that the beaker-shaped shade (2) has a common peripheral free edge (7) formed from the inner and outer wall portions (10 and 9).
5. Headlamp for vehicles according to one of the claims 1 to 4, characterised in that the cover formed by the base (4) is constructed, via a flexible flap (13), in one piece with the outer wall portion (9).
6. Headlamp for vehicles according to one of the claims 1 to 5, characterised in that the cover formed by the base (4) engages with a peripheral lateral edge section (8) facing towards the reflector in a peripheral step of an adjacent free edge (12) of the double-layered side wall (5) and passes flush, with the outer side of its lateral edge section (8), into the outer side of the double-layered side wall (5).
7. Headlamp for vehicles according to one of the claims 1 to 6, characterised in that the outer wall portion (9) of the double-layered side wall (5)¹ and the cover serving as the base (4) comprise a light sheet metal with a glossy silver-coloured surface, which is the outer side of the shade (2).
   ¹ Translator's note: There appears to be an error in the German original in the third line of claim 7. The reference number 8 has been used with the word Seitenwand (= 'side wall'), which is otherwise associated with the reference number 5. This has been amended accordingly in the translation.
8. Headlamp for vehicles according to one of the claims 1 to 7, characterised in that the inner wall portion (10) of the double-layered side wall (5) comprises sheet steel with a matt inner surface.
9. Headlamp for vehicles according to one of the claims 2 to 8, characterised in that the support element (6) is made from a doubled support arm which passes through a slit (15) bordered by the edges (14) of a seam (11) of the outer wall portion (9), said slit being laterally open only towards the reflector (1), whereby a seam (16) of the inner wall portion (10) passes through the two portions of the doubled support element (6) and said two portions are bound to the edges of the inner wall portion (10) forming the seam (16), in one piece with said edges.
10. Headlamp for vehicles according to one of the claims 2 to 9, characterised in that the outer wall portion (9) of the double-layered side wall (5) is non-detachably connected to itself in a section wherein the edges (14) of a seam (11) of the outer wall portion (9)² meet each other.
    ² In the last line of claim 10 in the German original, the reference number 10 has been used in conjunction with the words äußeres Wandteil (= 'outer wall portion'), whereas this term is otherwise associated with the reference number 9. This has been amended accordingly in the translation.

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