Field of the Invention
The present invention pertains to an upper MacPherson strut step bearing for wheel suspensions in motor vehicles and more particularly, the present invention relates to an upper MacPherson strut step bearing including a metallic housing in a vertical section which is pot-shaped, a rubber buffer arranged in the housing and a support piece which can be connected to a shock absorber and which extends with radially extending projections into the rubber buffer connected to it rigidly, wherein the radially extending housing edge forms an abutment for the annular spring buffer, by which the top end of the coil spring surrounding the shock absorber is supported and is connected to the cover plate of the housing, the cover plate being fastened to a part of the motor vehicle and covering the rubber buffer on its top side.
Background of the Invention
Such a MacPherson strut step bearing has been known from EP-0 136 023-A2. The outer edge of the housing, whose vertical section is pot-shaped, and the cover plate extend only radially in this prior-art design. They are usually welded together, and they do not form a radially acting guide for the top end of the coil spring of the MacPherson strut, which end is supported against the underside of the housing edge, or a support jacket for the spring buffer made of rubber or a comparable elastomeric material, so that this material can be squeezed out under a higher load and therefore it must have a corresponding material rigidity, which stands directly opposed to the desired comfort. The collar edge on the underside of the housing, which radially guides the shock absorber at the housing, is a separate component, which is connected to the bottom of the housing by spot welding.
Summary and Objects of the Invention
The primary object of the present invention is to improve the effect of such an upper MacPherson strut step bearing, to increase its stability, and to make it possible to manufacture it from a reduced number of components at a more favorable cost.
According to the invention, an upper MacPherson's strut step beating for wheel suspensions in a motor vehicle is provided including a metallic housing with a pot-shaped vertical section, a rubber buffer arranged in the housing and a support piece which can be connected to a shock absorber and which support piece extends with radially extending projections into the rubber buffer connected to it rigidly. A radially extending housing edge forms an abutment for an annular spring buffer by which the top end of the coil spring surrounding the shock absorber is supported. The radially extending housing edge is connected to the cover plate of the housing. The cover plate of the housing can be fastened to a part of the motor vehicle and the cover plate of the housing covers the rubber buffer on its top side. A collar edge for radially guiding the shock absorber, is located on the underside of the housing. The metallic housing is made from sheet metal formed in one piece with the collar edge, the collar edge being provided on the underside of the metallic housing. The metallic housing is wedged with or is wedged within the cover plate.
Considerable manufacturing costs are saved due to the one-piece design of the housing with the part made in one piece with it on its underside for receiving the top end of the shock absorber and for radially guiding same. However, greater stability of the housing is also achieved at the same time, so that smaller wall thicknesses can be selected at a higher possible load or, vice versa, higher loads can be absorbed. A separate manufacturing process for the collar edge commonly used previously and another operation for connecting this collar edge to the housing are eliminated.
In another embodiment according to the present invention, the housing is connected to a cover plate, which has a jacket ring which extends downwardly beyond the spring buffer and into which the top end of the coil spring of the MacPherson strut supported by the buffer ring extends. This also leads to a substantial improvement in the stability of the upper MacPherson strut bearing and at the same to a radially acting guiding for the top end of the coil spring of the MacPherson strut. In addition, the buffer ring, made of rubber or the like, is surrounded on its outer jacket side, so that lateral squeezing of the material of the buffer ring cannot occur any longer. The material may therefore be selected as a material of lower rigidity, or correspondingly higher loads can be transmitted. It also becomes possible to fasten the top end of the bellows, which normally protectingly surrounds the shock absorber, within the jacket ring provided on the cover plate, either as a component that is independent from the buffer ring or as a component made in one piece with the buffer ring.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
Brief Description of the Drawings
In the drawings:
FIGS. 1 and 2 of the drawing show vertical sections of two exemplary embodiments of a design according to the present invention.
Description of the Preferred Embodiment
In the exemplary embodiments, the upper MacPherson strut bearing comprises a metallic housing 1, whose vertical section in a plane passing through the central axis of the MacPherson strut is pot-shaped. A rubber buffer 2 is arranged in the said housing. A support piece 3 is provided, which can be connected to the shock absorber, not shown in the drawing, and which has radially directed (extending) projections 4, which extend into the material of the rubber buffer 2. A collar edge 5 is made from sheet metal in one piece with the wall of the housing 1 on the underside of the housing 1. The top end of the shock absorber, not shown, extends into this collar edge 5 up to housing bottom wall, so that it is radially guided (limited as to radial movement) and held as a result. The support piece 3 is connected to the shock absorber through the hole in the support piece 3. The housing 1 is closed on the top side by a cover plate 6, which surrounds the support piece 3 with a clearance, so that the support piece 3 is cardanically movable in relation to the housing, utilizing a corresponding clearance in the bottom of the housing 1. The radially extending projections 4 have openings in some areas. A cardanically reduced characteristic can be achieved in the plane of the load as a result. The rubber buffer 2 is clamped in the housing 1 with the cover plate 6 in the conventional manner. The radially outwardly directed edge 7 of the pot-shaped housing 1 and the cover plate 6 are wedged (pressed) together. This makes possible a final handling of both the housing 1 and the cover plate 6 before mounting. Both components can thus be subjected to surface treatment, especially lacquering, already prior to the connection. This is not possible in the case of a prior-art welding. Fastening elements for the connection to the part of the motor vehicle are located on the cover plate. Fastening screws 8, which pass through holes of both the radially directed housing flange 7 and the cover plate 6, are shown. The cover plate 6 passes over at the outer edge into a jacket ring 9, which is directed downward and extends beyond a spring buffer 10, by which the top end of the coil spring 11 of the MacPherson strut is supported.
In the exemplary embodiment according to FIG. 1, a bellows 12, protectingly surrounding the shock absorber, is made in one piece with the spring buffer 10. The fastening of the top end of the bellows 12 is brought about by the fastening of buffer ring 10.
In the exemplary embodiment according to FIG. 2, the top end of the sealing bellows 12 has an outwardly directed flange. The outwardly directed flange 13 is clamped between the buffer ring 10 and the flange 7 of the housing. Both representations show dearly that the buffer ring 10 and optionally also the radial flange 13 of the bellows 12 may have openings for fastening the upper MacPherson strut bearing to a part of the motor vehicle.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.