Lens holder for holding a lens in a headlamp

Abstract

A lens holder for holding a lens in a headlamp, and to a headlamp having such a lens holder, wherein the lens holder comprises a receptacle section for holding the lens and a mounting section, wherein the mounting section can be mounted in the headlamp by means of fasteners. The lens holder has an at least partially circumferential channel between the receptacle section and the mounting section.

Claims

1. A lens holder for holding a lens in a headlamp, the lens holder comprising: a receptacle section to hold the lens; a mounting section adapted to be mounted in the headlamp via at least one fastener; and an at least partially circumferential channel formed between the receptacle section and the mounting section, wherein the mounting section has screw openings in which the at least one fastener is inserted, wherein the receptacle section is a tubular hollow body with openings at each end, wherein a longitudinal axis of the hollow body is defined and the longitudinal axis passes perpendicularly through the openings at each end, wherein a transition section is provided that adjoins the mounting section and the receptacle section, the transition section being located between the mounting section and the receptacle section in an axial direction of the longitudinal axis, wherein the channel is provided in the transition section, the channel having a U-shaped and/or arched cross-section having a back wall, a front wall and a curved bottom connecting the back wall and the front wall, and wherein the back wall of the channel is a surface of the mounting section having the screw openings therein and the front wall of the channel is a surface of the receptacle section that opposes the surface of the mounting section having the screw openings therein.

2. The lens holder according to claim 1 wherein the channel extends radially around the transition section with respect to the longitudinal axis.

3. The lens holder according to claim 2, wherein the lens holder has a plurality of ribs, wherein the ribs are arranged on the lens holder on an outside and/or on an inside, and wherein the ribs each extend essentially axially along the mounting section, the transition section and the receptacle section with respect to the longitudinal axis.

4. The lens holder according to claim 1, wherein the receptacle section has an average radius with respect to the longitudinal axis, wherein the channel has an average depth, and wherein the average depth of the channel is 0.1 times to 0.5 times the average radius of the receptacle section.

5. The lens holder according to claim 4, wherein the average depth of the channel is 0.3 times the average radius of the receptacle section.

6. The lens holder according to claim 1, wherein the channel has a first section and a second section, wherein the first section and the second section are arranged on opposite sides of the lens holder.

7. The lens holder according to claim 1, wherein the lens holder is manufactured by an injection molding process.

8. A headlamp comprising: a supporting frame; and a lens holder to hold a lens, wherein the lens holder comprises a receptacle section for holding the lens and a mounting section, wherein the mounting section is connected to the supporting frame by screws, and wherein the lens holder has an at least partially circumferential channel formed between the receptacle section and the mounting section, wherein the mounting section has screw openings in which the screws are inserted, wherein the receptacle section is a tubular hollow body with openings at each end, wherein a longitudinal axis of the hollow body is defined and the longitudinal axis passes perpendicularly through the openings at each end, wherein a transition section is provided that adjoins the mounting section and the receptacle section, the transition section being located between the mounting section and the receptacle section in an axial direction of the longitudinal axis, wherein the channel is provided in the transition section, the channel having a U-shaped and/or arched cross-section having a back wall, a front wall and a curved bottom connecting the back wall and the front wall, wherein the back wall of the channel is a surface of the mounting section having the screw openings therein and the front wall of the channel is a surface of the receptacle section that opposes the surface of the mounting section having the screw openings therein.

9. The headlamp according to claim 8, wherein the channel extends radially around the transition section with respect to the longitudinal axis.

10. The headlamp according to claim 8, wherein the supporting frame is manufactured from a fiber-matrix semifinished product and the lens holder is manufactured from polycarbonate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1a is a first schematic representation of an embodiment of the lens holder according to the invention,

(3) FIG. 1b is a second schematic representation of the embodiment, and

(4) FIG. 2 is a cross-sectional representation of the embodiment.

DETAILED DESCRIPTION

(5) FIGS. 1a, 1b, and 2 show an advantageous embodiment of the lens holder 100 according to the invention, with a receptacle section 1, formed by a tubular hollow body, for holding a lens, with a mounting section 2 provided for connecting to the supporting frame, and with a transition section 5 that is arranged between the receptacle section 1 and the mounting section 2 and is partially surrounded by the channel 3 according to the invention. The longitudinal axis 4 passes through the geometric centroid of the lens holder 100 and forms the normal of the plane of the openings 11, 12 at the ends of the receptacle section 1. The screw openings 7 arranged on the mounting section 2 are used for the screw connection of the lens holder 100 to the supporting frame of a headlamp. The light source of the headlamp in this case is arranged relative to the lens holder 100 in such a way that the emitted light enters through the rear opening 12 of the receptacle section 1, then passes through a lens held in the receptacle section 1, and subsequently emerges from the front opening 11 of the receptacle section 1.

(6) When changes occur in the operating and/or ambient temperature of the lens holder 100 in a headlamp, the thermal expansion capability of the mounting section 2 is limited by the screw connection to the supporting frame of the headlamp, which usually is made of a different material than the lens holder 100. In order to avoid irreversible deformations and permanent distortion of the mounting section 2 in this case, according to the invention a thermomechanical decoupling from the receptacle section 1, which thermally expands freely, is carried out. This decoupling is realized by the intermediate transition section 5 with the partially circumferential channel 3. In FIG. 2, which shows a sectional view along the section lines II drawn in FIGS. 1a and 1b, the channel 3 is shown as an arched structure in the hatched section plane. The legs of the channel 3 connecting to the adjacent sections, which is to say to the receptacle section 1 and the mounting section 2, are each expanded according to the thermal expansion of the adjacent sections when temperature changes occur. Unequally large expansions of the receptacle section and the mounting section thus result in a deformation of the transition section 5, in particular in a change in the curvature of the channel 3, but not in an irreversible distortion of the lens holder 100, in particular of the mounting section 2 in the region of the screw connection to the supporting frame. Owing to this thermomechanical decoupling according to the invention of the receptacle section 1 and mounting section 2, the lens holder 100 is substantially more robust to repeated temperature changes as compared with prior art lens holders, which is to say that no distortion of the lens holder 100 that degrades the functionality of the associated headlamp occurs even after a great many temperature change cycles.

(7) In the embodiment of the lens holder 100 shown in FIGS. 1a, 1b, and 2, the channel 3 is implemented only in sections as a first section 31 and a second section 32 on opposite sides of the lens holder 100. This can serve, in particular, to ensure adequate mechanical stability and load capacity of the lens holder 100. The thermomechanical decoupling of the receptacle section 1 and mounting section 2 is thus not provided in all spatial directions. When the lens holder 100 is installed in a headlamp in a motor vehicle in such a manner that the longitudinal axis 4 is in the horizontal direction, then a thermomechanical decoupling is nonetheless provided in the vertical direction, which is to say, in particular, protection is provided against upward and downward displacements of the light cone projected onto the roadway. The ribs 6 formed on the lens holder 100 on the outside, which start at the mounting section 2 and extend along the mounting section 5 and the receptacle section 1, also serve to increase the load capacity of the lens holder 100. By means of these longitudinal ribs 6, loads can be transmitted into the supporting frame of the headlamp from the receptacle section 1.

(8) In FIG. 2, the average radius 10 of the receptacle section 1 and the average depth 30 of the channel 3 are shown. The average radius 10 of the receptacle section 1 is defined as the average distance between the longitudinal axis and the wall of the receptacle section 1 in the form of a hollow body, and the average depth 30 of the channel 3 is defined as the average radial distance, with respect to the longitudinal axis 4, between the bottom of the channel 3 and the wall of the receptacle section 1 in the form of a hollow body at the transition to the transition section 5. The ratio of the average depth 30 of the channel 3 to the average radius 10 of the receptacle section 1 is preferably chosen such that the lens holder 100 has thermomechanical decoupling from the receptacle section 1 and the mounting section 2 that is adequate for the practical use of headlamps while at the same time ensuring adequate stability and load capacity.

(9) The invention is not limited in its implementation to the preferred exemplary embodiment provided above. Instead, a number of variants are possible that make use of the described solution even in embodiments that are fundamentally different in nature. All features and/or advantages, including design details and spatial arrangements, that derive from the claims, the description, or the drawings, can be essential for the invention individually as well as in a wide variety of combinations.

(10) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.