EP0589189A1 - Vehicle headlamp - Google Patents

Abstract

The invention relates to a headlamp for vehicles with a shell-shaped lens (1) and a housing (2) made of plastic. The housing (2) has a receiving surface (6) for the diffuser base (5) on its outer peripheral edge. On the receiving surface (6) serving as a support for the lens (5) are raised (7) which are deformed when the lens (1) is placed on the housing (2) by pressing the lens base (5) against it, that they form a bed surrounding the diffusing plate base (5) at least on one side. In this bed the spreading disc (1) is held with its foot (5) by a mechanical device existing between the spreading disc (1) and the housing (2). <IMAGE>

Description

The invention relates to a headlight for vehicles, with a bowl-shaped lens and with a sealed from the lens, made of plastic housing, the free peripheral edge has a transverse to the mounting direction of the lens receiving surface on which the lens with its foot with a large game is placed transversely to the mounting direction, and the attachment of the lens to the housing is carried out by a mechanical device pressing the lens base in the direction of the receiving surface.

From DE 35 40 130 C1 a headlight is known, the bowl-shaped lens of which is inserted with its foot into a receiving channel of U-shaped cross section of the housing. Before mounting the spreading disc, an adhesive is introduced into the receiving groove, which surrounds the spreading disc base after the spreading disc has been placed on the housing. After the adhesive has hardened, the connection it creates between the housing and the lens is very strong, even without additional mechanical elements, and the adhesive is also a good sealant. The disadvantage here is that in a housing made of plastic, the selection of the type of plastic is very limited, since not all plastics - such as. B. the thermoplastic polypropylene - let it glue well with an inexpensive adhesive. The elimination of this disadvantage can be achieved with the connection technology which is used in the headlight known from DE 28 46 990 A1, from which we started when forming the generic term of claim 1. The connecting compound introduced between the lens and the edge of the housing in this headlight is viscous, so that the adhesive effect of the connecting compound is very small and the connecting compound primarily serves as a seal. This connection technology has been put into practice shown that the lens in the mounting position of the headlamp moves due to the fluidity of the sealant in the direction of its gravity until it abuts with its foot on the inner and / or bottom of the outer leg of the receiving channel. There is a risk of the lens spreading, particularly at higher temperatures, because the degree of toughness of the connecting compound then decreases. The mechanical device, which is formed by locking lugs formed on the outer leg of the receiving channel, which engage in a step of the lens and lock it in the mounting direction, does not prevent the lens from moving downward.

The distance between the two legs of the U-shaped receiving channel is greater than the thickness of the base of the lens and the greater the larger the housing made of plastic, and the distance is particularly large if an inexpensive plastic is used to manufacture the housing, through which large manufacturing tolerances arise for the housing. The large manufacturing tolerances of a diffusing screen made of pressed glass also contribute to the widening of the receiving channel. In the headlight known from DE 28 46 990 A1, the mechanical devices which lock the lens on the housing are resilient lugs formed on the outer leg of the receiving groove and engage in a step on the outside of the lens. As a result, the lens is only held on the housing in the mounting direction.

From DE-GM 76 26 043 a headlight has become known in which a rubber seal is inserted as a sealing means in the cross-sectionally U-shaped receiving groove of the housing. The lens is pressed against the rubber seal by a mechanical device. It is disadvantageous here that the seal made of rubber is an additional part and is very expensive to produce, since it is either a molded seal or an extruded seal. The The string seal must be cut exactly to length so that there is no leak at its joint. In addition, after it has been put on, the lens must be held in a precisely positioned position relative to the housing until the mechanical device is mounted. The mechanical device consists of a C-shaped retaining spring made of spring sheet metal, which engages with one leg in a step of the lens and with the other leg in a step of the housing. Furthermore, the brackets must be made very stable so that the contact pressure of the lens against the rubber seal is so high that the voluminous seal is deformed by the base of the lens to ensure that the lens can not move down with its foot.

The object of the invention is to design the headlights described in the preamble of claim 1 in such a way that the lens with its foot is centered on a receiving surface that is essentially wider because of large manufacturing tolerances than is required for the thickness of the lens, and so without additional Attach components or operations to the receiving surface so that the lens is centered in the housing transverse to its mounting direction. This object is achieved according to the invention in that the support of the lens base is formed by projections protruding from the receiving surface, which are deformed when the lens is placed on the housing by pressure of the lens base against it so that it is at least one side of the lens base narrow Form the surrounding bed.

In such an advantageous solution, the lens is exactly aligned with the housing when it is assembled by, after the lens foot rests on the elevations in the receiving surface, exerts so much pressure on the elevations with its lens base that the webs deform and contract the Form the base of the lens at least on one side. The mechanical device that holds the lens on the housing thus serves only to hold the base of the lens in the bed and thus does not have to prevent the lens from moving downward. In addition, it is not necessary in automatic production to hold the diffuser after it has been put on until the mechanical device has been mounted by the device which is putting it on.

The connection technology that precisely aligns the lens with the housing is necessary so that, in the case of a headlight installed in the body opening, the outer surface of the lens is flush with the surface of the body adjacent to the lens. In addition, it is always ensured in the embodiment according to the invention that the small gap existing between the lens and the adjacent body cannot be reduced by migration of the lens. Otherwise the lens could come into contact with the lower body part adjacent to it and be damaged. In addition, a lens provided with optical means would no longer be precisely aligned with a reflector of the headlight.

It is also advantageous if the housing is made from a thermoplastic material that is resistant to high heat distortion. When using the thermoplastic polypropylene, a cold deformation of the elevations is advantageous, and in addition, polypropylene is very inexpensive and, due to its high heat resistance, very suitable for a headlight housing, however, very large manufacturing tolerances occur on the housing due to the use of polypropylene. Since only the latter is disadvantageous when using polypropylene, it is ideally suited for a housing with the features according to the invention. In this context, it is also advantageous if the elevations are directly molded onto the base of the receiving channel. Such a solution is simple and inexpensive to manufacture. The deformation of the protrusions is plastic, and because the housing is made of a thermoplastic, the deformation is possible with a small force. When using the thermoplastic PBTP, a thermoforming of the elevations is advantageous. The elevations can be heated by a heating device. The higher the temperature of the elevations, the easier they are to plastically deform them.

It is also advantageous if the elevations are webs which run transversely to the longitudinal extent of the receiving surface and extend approximately over the entire width of the receiving surface. It is useful if the receiving surface is the base of a U-shaped receiving groove in cross section and the webs connect the legs of the U-shaped receiving groove with each other. Here, the legs of the receiving channel serve as holding elements for the webs when the webs are deformed. The holding elements ensure that the entire web is not deformed and the bed created by deformation for the diffuser base always has the desired depth.

Another advantage is that the webs are designed as thin walls. With such a solution, only a small force is required to deform the thin walls, since the specific pressure acting on the walls is very high because of the thin walls of the walls. In the case of thin walls formed exclusively on the base of the receiving channel, it is very advantageous if the thin walls point against the direction of attachment of the diffusing screen, since this ensures that the walls do not bend when they are put on, but are plastically deformed. In the case of thin walls connecting the legs of the receiving channel, it is advantageous if these run at an acute angle to the base of the receiving channel. As a result, a small force is required for the deformation.

It is also advantageous if the webs taper towards the free end. Such a web is very stably connected to the receiving channel and its free end section can be deformed by a small force.

It is also advantageous if elevations in their cross-section have side surfaces which run at an acute angle to one another, one of which extends in the direction of placement of the diffusing screen on the housing. As a result, the webs cannot buckle when the spreading disc is put on.

It is also advantageous if the side faces describe a concave arc in the cross section of the web. Here, the free end portion of the web is made very thin, so that a high specific pressure acts on it when it is deformed. Since the cross-section of the web to be deformed rapidly increases when the diffuser is put on, the end position of the diffuser towards the housing hardly varies even with different pressure on the web.

Furthermore, it is advantageous if, after the deformation of the elevations, the base of the lens lies against stops which are formed by projections molded onto the receiving groove. As a result, from a certain force with which the lens is placed on the housing, the position of the lens to the base of the receiving groove of the housing is precisely determined.

In another advantageous development of the invention, the elevations are designed as rods which are arranged close to one another. When the spreading disc is placed on the housing, the rods below the spreading disc base are pushed away with plastic and / or elastic deformation and, if they protrude together in a brush-like manner from the base of the receiving channel, can adhere to the inner surfaces of the legs of the U- support shaped receiving channel.

In a particularly advantageous development of the invention, elevations are formed by a roof-shaped and thin-walled section of the wall of the receiving channel which has the base area, the roof with its ridge extending transversely to the receiving channel. Such a roof is easy to demold. Such an embodiment is particularly advantageous if the side surfaces of the roof run at an angle that is a right or larger. The upper end portion of the roof can be deformed the easier the thinner the roof is. This thin wall does not impair the good demouldability of the roof. The roof-shaped elevations are particularly suitable when the angle between the demolding direction of the receiving groove of the housing and the mounting direction of the lens is a large acute angle.

In a further advantageous development of the invention, a pasty sealing means is introduced into the receiving groove, which fills the gaps between the U-shaped receiving bed and the diffuser base. The doughy sealant, which is primarily used for sealing, is placed in the receiving channel before the diffuser is heated up, if it has good flowability, and only then is the diffuser placed on the housing. The raised sealant heats up due to the heated sealant and can be deformed with less force. In addition, the sealing between the lens and the housing is very good due to the doughy sealant if the gap receiving the doughy sealant between the diffuser base fixed in the bed of the elevations and the legs of the receiving channel is made correspondingly wide. The doughy sealant is particularly advantageous when the housing is made of a plastic such. B. is made of thermoplastic (polypropylene), which can not be glued by an inexpensive adhesive. In this context, it is also advantageous if the diffusing screen placed on the housing is fixed by the clamps forming the mechanical device, which clamps with engage one leg in an undercut of the lens and with the other leg in an undercut of the housing and press the lens against the housing with its force. Only a few clamps are required here, since they only have to lock the spreading disc in its mounting direction and the clamp force is defined for this locking.

• Fig. 1 und Fig. 2 ein erstes Ausführungsbeispiel in einem Schnitt durch eine Teilansicht eines Scheinwerfers mit einer Streuscheibe vor und nach dem Einsetzen in eine Aufnahmerinne des Gehäuses, in welcher eine Erhöhung ein Steg ist, in welchen der Streuscheibenfuß durch Verformung ein ihn aufnehmendes Bett eingedrückt hat,
• Fig. 3 und Fig. 4 eine zweite Ausführungsform in Teilansichten, die den Figuren 1 und 2 ähnlich sind, jedoch sind die Erhöhungen von aus der Grundfläche der Nut hervorspringenden Stäbchen gebildet,
• Fig. 5 eine Ansicht aus Richtung Y auf die Aufnahmerinne der Fig. 3,
• Fig. 6 einen mittleren Längsschnitt durch eine Aufnahmerinne des Gehäuses mit einem Steg vor und nach seiner Verformung und von Vorsprüngen gebildete Anschläge für die Streuscheibe und die
• Figuren 7 bis 11 jeweils eine andere Ausführungsform der aus der Grundfläche der Aufnahmerinne hervorspringenden Erhöhungen.

In the drawing, several embodiments of the invention are shown, namely show

• Fig. 1 and Fig. 2 shows a first embodiment in a section through a partial view of a headlamp with a lens before and after insertion in a receiving groove of the housing, in which an increase is a web, in which the base of the lens by deformation of a bed receiving it has indented
• 3 and 4 show a second embodiment in partial views, which are similar to FIGS. 1 and 2, but the elevations are formed by rods projecting from the base of the groove,
• 5 is a view from the direction Y of the receiving channel of FIG. 3,
• Fig. 6 shows a central longitudinal section through a receiving groove of the housing with a web before and after its deformation and stops formed by projections for the lens and
• FIGS. 7 to 11 each show another embodiment of the elevations protruding from the base of the receiving channel.

The drawing shows the outer edge section of a bowl-shaped diffusing screen (1) and the outer edge section of a pot-shaped housing (2), which can also be a reflector. The housing (2) is made of thermoplastic "polypropylene", and the lens (1) is made of glass. The distance between the legs (4) of the receiving channel (3) which is U-shaped in cross section is substantially greater than the thickness of the base of the diffusing screen (5). From the base area (6) of the receiving channel (3) serving as the receiving area (6) for the lens (5), elevations (7) protrude, which are distributed over the entire length of the receiving channel (3). In FIGS. 1, 2, 6, 7, 8, 9 and 11, the elevations (7) are webs which run transversely to the receiving channel (3) and connect the legs (4) of the receiving channel to one another.

In the case of automatic assembly, the lens (1) is placed on the housing (2) by means of a device aligned precisely with the bowl-shaped housing (2). When the spreading disc (1) is placed on the housing (2), the spreading disc base (5) first grips between the legs (4) of the U-shaped receiving channel (3) and, after its base surface (10) is placed on the elevations (7) pressed strongly against its support so that the elevations (7) deform and form a bed (8) which lies closely against the base of the lens (5). The diffuser (1) is fixed to the housing (2) radially to its mounting direction (X) by the bed (8). The spreading disc (1) is locked onto the housing (2) in the mounting direction (X) by the mechanical device (9), which is formed by a bracket bent from a spring plate in a C-shape. The clamp (9) engages with one free leg in a step of the lens (1) and the housing (2) and presses the lens (1) in the direction of the housing (2).

In FIGS. 6 and 7, the elevation (7) is a thin-walled web which runs at an acute angle to the base area (6) of the receiving channel (3). After the thin-walled web (7) has been deformed by the diffuser base (5), its base (10) rests against stops (11) which are formed on the base surface (6) of the receiving channel (3) between the elevations (7) Projections are formed. In Figures 7, 8 and 9, the web (7) tapers towards its free end. In FIGS. 7 and 9, the side surfaces (12) of the web (7) run at an acute angle to one another, wherein in FIG. 9 one of the side surfaces runs in the direction of attachment (X) of the lens (1). In FIG. 8, the side surfaces (12) run in a concave arc in the cross section of the web (7).

In FIG. 10, the elevation (7) is formed by a thin-walled section of the wall of the receiving channel (3) which has the base area (6). The thin-walled section (7) is roof-shaped, the ridge of the roof extending transversely to the receiving groove (3). One of the two side surfaces of the roof (7) extends in the mounting direction (X) of the diffuser (1).

In Figures 3, 4 and 5, the elevations (7) are thin rods, which together protrude like brushes from the base (7) of the receiving channel (3). When the spreading disc (1) is placed on the housing (2), the thin-walled rods below the base surface (10) of the spreading disc (1) are plastically deformed and the other rods are pressed away laterally with their free end section under elastic and plastic deformation. Here, they can be supported on the inside of the legs (4) of the receiving channel (3). The base area (6) of the receiving channel (3) is designed in a brush-like manner in sections distributed over its entire length.

In order to obtain a tight connection between the lens (1) and the housing (2), it is very advantageous if a sealing means (not shown) is introduced into the U-shaped receiving groove before the lens is installed. A doughy sealant is known from practice, which has good flowability in the heated state and is introduced into the receiving groove (3) in this state and after the spreading disc (1) has been placed on the housing, the spreading disc base (5) up to close to the Tightly surrounds the edge of the receiving channel (3). After the sealant has cooled, it is viscous, so that this sealant is primarily used for sealing. It is advantageous if there is such a small gap between the base plate surface (10) and the base surface (6) of the receiving channel (3) that the sealing agent is held on its side surfaces by adhesion.

Reference numerals Headlights for vehicles

(1)

Lens

(2)

casing

(3)

Receiving channel

(4)

leg

(5)

Lens base

(6)

Floor space

(7)

Increases

(8th)

bed

(9)

mechanical device

(10)

Foot surface

(11)

attack

(12)

Side surface

(X)

Direction of touchdown

Claims (23)

Headlights for vehicles, with a bowl-shaped lens (1) and with a plastic housing (2) which is closed off from the lens (1) and the free peripheral edge of which has a receiving surface (6) running transversely to the direction of attachment of the lens (1), on which the lens (1) is placed with its foot (5) with a large amount of play transversely to the mounting direction, and the attachment of the lens (1) to the housing (2) by means of a lens base (5) in the direction of the receiving surface (6 ) pressing mechanical device (9), characterized in that the support of the diffuser base (5) is formed by protrusions (7) protruding from the receiving surface (6), which when the diffuser (1) is placed on the housing (2) a pressure of the diffuser base (5) against them is deformed such that they form a bed (8) which closely surrounds the diffuser base (5) at least on one side. Headlamp according to claim 1, characterized in that the housing (2) is made from a thermoplastic which is resistant to high heat distortion. Headlamp according to claim 2, characterized in that the thermoplastic is polypropylene (PP). Headlight according to claim 2, characterized in that the thermoplastic is polybutylene terephthalate (PBTP). Headlamp according to one of Claims 1 to 4, characterized in that a limiting web which is integrally formed on the receiving surface (6) forms an L-shape in cross section together with the receiving surface (6). Headlamp according to one of claims 1 to 4, characterized in that two limiting webs formed circumferentially on the receiving surface (6) together with the receiving surface (6) form a U-shaped receiving channel (3) in cross section. Headlamp according to claim 6, characterized in that the elevations (7) are directly molded onto the base surface of the receiving channel (3) serving as the receiving surface (6). Headlight according to one of claims 1 to 7, characterized in that the elevations (7) are webs which run transversely to the longitudinal extent of the receiving surface (6) and extend approximately over the entire width of the receiving surface (6). Headlight according to claim 8, characterized in that the webs (7) connect the legs (4) of the U-shaped receiving channel (3) to one another. Headlamp according to claim 8 or 9, characterized in that the webs (7) are designed as thin walls. Headlamp according to claim 8 or 9, characterized in that the webs (7) taper towards the free end. Headlamp according to claim 11, characterized in that the elevations (7) have side surfaces (12) running at an acute angle to one another in their cross section. Headlamp according to claim 11 or 12, characterized in that one of the side surfaces (12) of the webs (7) extends in the direction of placement of the lens (1) onto the housing (2). Headlamp according to claim 11, characterized in that in the cross section of the web (7) the side surfaces (12) describe a concave arc. Headlamp according to one of claims 1 to 14, characterized in that after the deformation of the elevations (7) the diffuser (1) rests with its foot surface (10) against stops (11) which are formed by projections molded onto the receiving surface (6) are. Headlight according to one of the preceding claims, characterized in that the elevations (7) are designed as rods which are arranged closely next to one another. Headlight according to claim 16, characterized in that the rods project together like a brush from the receiving surface (6). Headlight according to one of the preceding claims, characterized in that elevations (7) are formed by a roof-shaped and thin-walled section of the wall having the receiving surface (6), the ridge (7) with its ridge transverse to the longitudinal extent of the receiving surface (6) runs. Headlight according to claim 18, characterized in that the side surfaces (12) of the roof (7) run at an angle to one another which is at least a right one. Headlight according to one of the preceding claims, characterized in that a pasty sealing agent is applied to the receiving surface (6), which fills the gap between the receiving surface (6) and the lens base (5). Headlight according to one of the preceding claims, characterized in that a pasty sealing means is introduced into the receiving channel (3), which fills the gaps between the U-shaped receiving bed (3) and the diffuser base (5). Headlamp according to one of the preceding claims, characterized in that brackets serve as the mechanical device (9) which engage on the outside of the headlamp with one leg in each case in an undercut in the outer edge portion of the lens (1) and the housing (2). Headlamp according to claim 10, characterized in that the thin walls (7) run at an acute angle to the base surface (6) of the receiving channel (3).

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