Method and device for joining a lens with a housing of a lighting device for a motor vehicle

Abstract

A method for joining a lens with a housing of a lighting device for a motor vehicle, having the steps: positioning the housing in a receiving device of a welding device, said housing having on its underside at least one fastener for attaching the lighting device in the motor vehicle, identifying the position of the at least one fastener relative to the receiving device, calculating a correction value on the basis of the identified position of the at least one fastener, and moving the lens held in a holding device of the welding device in the direction of the housing along a travel distance and welding the lens to the housing.

Claims

1. A method for joining a lens with a housing of a lighting device for a motor vehicle, the method comprising: positioning the housing in a receiving device of a welding device, an underside of the housing having at least one fastener for attaching the lighting device in the motor vehicle; identifying a position of the at least one fastener relative to the receiving device to obtain a correction value; moving the lens, which is held in a holding device of the welding device, along a travel distance in the direction of the housing; and welding the lens to the housing, wherein a length of the travel distance is corrected by the correction value such that in a welded state of the lens to the housing, a defined target height of the lighting device is created, the defined target height being measured from a reference surface of the at least one fastener to an upper surface of the lens facing away from the housing.

2. The method according to claim 1, wherein the housing is positioned in the receiving device, such that the reference surface of the at least one fastener is oriented toward an inner surface of the receiving device.

3. The method according to claim 2, wherein the position of the at least one fastener is determined by identifying a distance between the reference surface of the at least one fastener and the inner surface of the receiving device, the distance between the reference surface of the at least one fastener and the inner surface of the receiving device being the correction value.

4. The method according to claim 1, wherein the position of the at least one fastener is identified by a sensor element.

5. The method according to claim 1, wherein the correction value is transmitted to a control unit of the welding device, which controls the travel distance of the lens or the travel distance of the housing.

6. The method according to claim 1, wherein the welding of the lens to the housing is terminated upon reaching the defined target height.

7. The method according to claim 1, wherein the welding is carried out by a concurrent ablation process.

8. The method according to claim 1, wherein the at least one fastener includes two or more fasteners, wherein the position of the two or more fasteners is identified, wherein a mean value is calculated from the positions of and wherein the correction value is based on the mean value.

9. A welding device for joining a lens with a housing of a lighting device for a motor vehicle, the welding device comprising: a receiving device for receiving and positioning the housing; a holding device for holding and moving the lens; and a welder for welding the lens to the housing, wherein the receiving device comprises a sensor element via which a position of at least one fastener of the housing relative to the receiving device is identified so as to obtain a correction value and the lens is moved along a travel distance when welding to the housing, wherein a length of the travel distance is corrected via the correction value such that in a welded state of the lens to the housing, a defined target height of the lighting device is created, the defined target height being measured from a reference surface of the at least one fastener to a top surface of the lens facing away from the housing.

10. The welding device according to claim 9, wherein the sensor element is arranged on an inner surface of the receiving device.

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. 1 is a schematic representation of a welding device for joining a lens with a housing of a lighting device at the beginning of a joining process according to the invention; and

(3) FIG. 2 is a schematic representation of the welding device shown in FIG. 1 at the completion of the joining process according to the invention.

DETAILED DESCRIPTION

(4) FIG. 1 shows a welding device 100, by means of which a lens L constructed of a plastic can be cohesively connected to a plastic housing G of a lighting device.

(5) The lens L is arranged on a holding device 10, wherein by means of the holding device 10, the lens L can be moved down or lowered in the direction of the housing G.

(6) The housing G is positioned in a receiving device 11, which in turn is connected fixed in position to a base plate 12. The receiving device 11 has a receiving collar 14 projecting upwardly from a bottom plate 13 of the receiving device 11, on which the housing G can rest with its edge region R.sub.G, which also forms the joint portion of the housing G. The receiving device 11 thus has a U-shape in cross-section. The receiving collar 14 forms a support surface for the joint portion of the housing G so as to absorb the forces acting on the edge region R.sub.G of the housing G that forms the joint portion during joining. The housing G thereby rests on the receiving collar 14 in such a way, that the bottom B.sub.G of the housing G is arranged freely suspended in the receiver 11. The underside U.sub.G of the housing G, which forms the underside U.sub.G of the bottom B.sub.G of the housing G, is thus arranged spaced apart from an inner surface 15 of the receiving device 11. In the embodiment shown here, several fastener A in the form of screw domes are arranged at the underside U.sub.G of the housing G, which protrude from the underside U.sub.G. The fastener A are used to fasten the housing G and thus the finished, joined lighting device B in the motor vehicle, particularly on the body of the motor vehicle, by passing screws through the fastener A. The fastener A are also formed of plastic and are equally molded in the injection molding process when the housing G is formed.

(7) After positioning the housing G in the receiving device 11, prior to beginning the actual welding operation, first the position of one or more of the fastener A relative to the receiving device 11 is identified. In this case, the lens L is still positioned at a distance from the housing G, as can be seen in FIG. 1. The position of one or more of the fastener A is identified by means of a sensor element 16.

(8) The housing G is positioned in the receiver 11 in such a way that the fastener A are oriented with their reference surface S.sub.A toward the inner surface 15 of the receiver 11. The position of one or more of the fastener A is determined by the sensor element 16, by identifying the distance between the reference surface S.sub.A of one or more of the fastener A and the inner surface 15 of the receiving device 11.

(9) From the identified position of one or more of the fastener A, wherein the reference surfaces S.sub.A of the fastener A respectively serve as a reference point, a correction value Δx is calculated. This calculated correction value Δx is transmitted to a control unit of the welding device 100, which controls the movement and the travel distance of the lens L. The resulting length of the travel distance x.sub.res is calculated from a base travel distance x.sub.0 and the correction value Δx:
x.sub.res=x.sub.0±Δx.

(10) By means of the control unit, the lens L is now moved in the direction of the housing G along the previously identified, resulting travel distance x.sub.res, along with a welding of the lens L to the housing G performed therewith, as soon as such comes to rest on the edge region R.sub.G of the housing G through the edge region R.sub.L of the lens L. The welding is carried out, for example, by means of a friction welding process.

(11) The movement of the lens L over the previously determined length of the travel distance x.sub.res, in a welded state of the lens L to the housing G, as shown in FIG. 2, ensures a defined target height H of the lighting device B, measured from the reference surface S.sub.A of one or more of the fastener A to the top surface O.sub.L of the lens L facing away from the housing G. All lighting devices B manufactured or joined in such a manner have such an equally high target height H, so that it can be ensured that during installation of the lighting devices B in the body of a motor vehicle, these always sit flush with the outer skin of the motor vehicle.

(12) The indentation depth t, also called welding depth, of the edge region R.sub.L of the lens L into the edge region R.sub.G of the housing G, resulting during the welding operation, can have a different value for each lighting device B so that the tolerances of the lens L made of plastic and of the housing can be compensated over the different indentation depths t without changing the dimensions, in particular the target height H of the finished, joined lighting devices B.

(13) The invention is not limited in its execution to the above preferred embodiment. Rather, a number of variants are conceivable, which makes use of the illustrated solution even with fundamentally different embodiments. All of the features and/or advantages arising from the claims, the description or the drawings, including design details, spatial arrangements and method steps, can be essential to the invention both by themselves and in various combinations.

(14) 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