Patent Application
20070236954
The present invention relates to mounting arrangements for isolating automotive components from vibration. More particularly, the present invention relates to mounting arrangements for isolating automotive components from vibration wherein the automotive components are items, such as, but not limited to, headlamp housings with headlamps therein.
Automotive components, such as electrical devices, fragile mechanisms and lamp devices, frequently require isolation from vibration. Exemplary of such devices are vehicle headlamps which are normally mounted to the body of a vehicle. Headlamps are more fragile than other lamps in the vehicle in that they include many more internal parts such as brackets, reflectors, bulbs, internal adjuster mechanisms, and in some cases a projector lamp. Currently, headlamps are mounted directly to the body of a vehicle; however, mounting headlamps directly on vehicle frames or on bumpers is under consideration because it may be desirable to install headlamps at a lower height. This raises a concern because acceleration levels from road impacts into the frames of automotive vehicles are higher than acceleration levels into bodies mounted on frames.
A standard practice is to attach or support items such as headlamp housings with expensive rubber isolators that need adequate stiffness while simultaneously isolating damaging vibration loads. Such isolators use variables such as geometry, durometer and internal coring to produce correct stiffness in XYZ directions. This results in high costs and high dimensional variability. Current vehicles have very small gap and flush requirements and hence it is difficult to use elastomeric isolators to accurately locate a lamp housing to external surfaces of the vehicles. Exemplary of such surfaces are the surfaces of bumpers which are attached directly to the vehicle frames. When attaching a headlamp housing to a frame, it is necessary to have a minimal stiffness of about 45 Hz to prevent perceived visual flutter of the light beam, yet stiffness above about 45 Hz can transmit damaging impacts to the headlamp components.
In view of the aforementioned considerations, there is a need for an arrangement to mount components, such as vehicular headlamp housing, directly to a vehicle frame, rather than to the body of the vehicle.
A mounting arrangement for mounting a support structure for an automotive component on an automotive vehicle comprises at least one unitary beam. The unitary beam has a column portion with a coupling component thereon for attaching the unitary beam to the automotive vehicle. A fork-shaped portion of the unitary beam extends from the column portion and has a base extending in opposite directions of, and transversely with respect to, the column portion. At least a pair of arms are unitary with the base and extend transversely with respect to both the base and the column portion, the arms each having ends joined to the supporting structure of the automotive component.
In still a further aspect, the column portion has a front and a rear surface and the coupling component comprises a screw received through a hole in the column portion, which screw is threaded into a nut adjacent to the rear surface of the column portion.
In still a further aspect, the nut is a J-nut having a threaded opening adjacent to the rear surface of the column portion for receiving the screw.
In still a further aspect, a locating pin projects from the column portion in a direction away from the arms.
In still a further aspect, the arms are integrally molded with the supporting structure.
In another embodiment, the arms are separate from the supporting structure and are coupled thereto by fasteners.
In a further aspect, the supporting structure is an automotive headlamp housing.
In a further aspect, the mounting arrangement is for an automotive headlamp housing mounted by an array of four unitary beams with a pair of the unitary beams joined to opposite sides of the housing.
In still a further aspect, the beams are tuned beams tuned to provide a minimum natural frequency in a range of about 30 to 60 Hz, and preferably about 45 Hz.
In still a further aspect, the headlamp housing is mounted by the pairs of unitary beams to proximate portions of a bumper which comprises the automotive structure.
In still further aspects, the unitary beams each have a locating pin projecting from the front surfaces of the column portions for engagement with the bumper portion, the couplings between the columns and the bumper portion being screws passing through holes in the bumper portion.
In still a further aspect, the automotive headlamp housing and unitary beams are made of a polymer material, which is preferably 30% talc filled polypropylene.
In still further aspects, the unitary beams are unitary with the automotive headlamp housing, and alternatively the unitary beams are separate from the automotive headlamp housing and are attached thereto by fasteners.
Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
Referring now to
Unitary beams 14 are each similar in configuration, and as is apparent from the views of
In
As is seen in
Unitary with the column portion 50 of each of the unitary beams 14 is a fork-shaped portion 54 which is generally U-shaped in that it has a base 56 which extends in opposite directions transversely with respect to the column portion 50. First and second arms 60 and 62 extend in spaced relation laterally from end portions of the base 56 to the headlamp housing 12. The column portion 50, base portion 56 and arm portions 60 and 62 are simple beams molded from plastic that provide vertical and fore-aft flexibility for the headlamp housing 12 and thus the headlamp 10 therein. The geometry of the unitary beam 14 comprised of the simple beams 50, 56, 60 and 62 is adjusted to tune the supported lamp 10 and housing 12 to a first natural frequency in a range of 30-60 Hz with a preferably frequency of about 45 Hz. Preferably, the arms 60 and 62 are wider at the ends 64 and 66 where they join the housing 12, then where the arms join the base portion 56.
Referring now to
While the unitary beams 14 are in the illustrated embodiment used to support headlamp housing 12, the unitary beams are also of use in supporting other vehicular components.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
