Rear-mounted air guide device for a motor vehicle

A rear-mounted air guide device for a motor vehicle includes an air guide element which can be adjusted in relation to the vehicle body between a retracted inactive position and an extended active position. In the retracted inactive position, the air guide element, which forms the upper body surface in some regions, has a different attack angle than in the extended active position, in which the air guide element extends in a spaced manner to the upper body surface. A device, provided for fastening and adjusting the air guide element, has a simpler design, can be produced more inexpensively, and requires little space, is provided by way of at least one support, seated displaceably on the vehicle body, which can be moved in the vertical direction and which includes on its upper end region a contact area for the air guide element pivoted on the support. The air guide element, in the extended active position, rests in some regions on the contact area of the support and is held in this position by a spring element. In retracted inactive position, the air guide element is swiveled against the action of the spring element and is supported on its bottom by the vehicle body.

This application claims the priority of German application 10 2005 008 001.4, filed Feb. 22, 2005, the disclosure of which is expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a rear-mounted air guide device for a motor vehicle including an air guide element which can be adjusted in relation to a vehicle body between a retracted inactive position, forming an upper body surface in some regions and having a different attack angle than in an extended active position, in which the device extends in a spaced manner with respect to the upper body surface, and to a device for fastening and adjusting such an air guide element.

German patent DE 42 07 658 C2 discloses a rear spoiler for a motor vehicle including an air guide element which can be adjusted in relation to the vehicle body between a retracted inactive position and an extended active position. The air guide element, in the retracted inactive position, forms the upper body surface in some areas and has a different attack angle than in the extended active position, in which the element extends spaced from the upper body surface.

The air guide element is fastened and adjusted by at least one kinematic gear including a rocker arm. An end of the rocker arm pointing to the vehicle top is rotatably connected to the air guide element, and the other end thereof is pivoted at the vehicle body. The gear also includes a multi-link joint rod chain, which is rotatably connected to the air guide element and the rocker arm, respectively, and pivoted in a joint rod bearing, which can be adjusted in position, and has a drive for the rocker arm and the joint rod chain.

One disadvantage of this arrangement is that the device used to fasten and adjust the air guide element has a complex configuration with a plurality of components, which results in high costs and a relatively high space requirement in the rear of the motor vehicle.

It is an object of this invention to further develop a device for fastening and adjusting the air guide element of an air guide device such that it has a simplified configuration, can be produced inexpensively, and requires little space.

This object is achieved according to the invention by providing at least one support, which is seated displaceably on the vehicle body and can be moved in the vertical direction. On its upper end region, the support includes a contact area for the air guide element pivoted on the support. The air guide element, in the extended active position, rests in some regions on the contact area of the support and is held in this position by a spring element. In the retracted inactive position, the air guide element is swiveled against the action of the spring element and is supported on its bottom by the vehicle body. Additional features of the invention are apparent from the dependent claims.

Advantages achieved with the invention include provision of a pivoted connection of the air guide element to at least one support that is adjustable in the vertical direction. The arrangement of a spring element between the air guide element and support as well as the contact areas on the supports and the recessed accommodation in the vehicle body also permit the air guide element to be adjusted automatically when retracting and extending the supports. This kinematic arrangement has a simplified design with few components, can be produced inexpensively, and requires little space.

DETAILED DESCRIPTION OF THE INVENTION

A motor vehicle1in the form of a sports car includes an air guide device3with a wing-like air guide element4in a tail region2. The element is adjustable in relation to an adjoining vehicle body5between a retracted inactive position A, in which it forms the upper body surface6in some regions, and an extended active position B, in which the element extends in a spaced manner with respect to the upper body surface6.

In the retracted inactive position A, the outside7of the air guide element4extends with its upper surface flush with respect to sections of the fastback-like vehicle body5arranged upstream and downstream and has a different attack angle than in the extended active position B. In the active position B, the air guide element4is disposed such that the upper outside7′ of the air guide element4is arranged either horizontally or at a slight incline towards the rear (FIG. 2).

In order to fasten and adjust the air guide element4, a device8is provided. The device8comprises at least one support9, which is seated on the vehicle body5, is displaceable in the vertical direction C—C, and comprises at its upper end region at least locally a contact area10for the air guide element4, which is pivoted at the support9. In the extended active position B, the air guide element4rests in some regions on the contact area10and is held in this position by a spring element11. In the retracted inactive position A, the air guide element4is swiveled against the action of the spring element11and in doing so is supported with its bottom12in some regions by a recess13of the vehicle body5for accommodating the air guide element.

In the illustrated example, two spaced, adjustable supports9are provided for adjusting and fastening the air guide element4(FIG. 1). Viewed in a cross-sectional perspective, the hollow body-like supports9have oval, circular, or similar shapes, and the tops of the supports9may be closed off in some regions. On lower end regions, the supports9interact with a conventional drive device, which is not shown in detail, such that straight or arched retraction and extension movements of the supports9in the vertical direction C—C are guaranteed.

In the illustrated example, the air guide element4is rotatably connected in a rear region of its longitudinal extension to an upper end region of each support9about a transverse, substantially horizontally aligned axis of rotation14. A substantially upright spring element11, the one end15of which is connected to the air guide element4and the other end16of which is connected to the support9, extends in a spaced fashion to the axis of rotation14of the air guide element4. In this active position B, the spring element11pulls the air guide element4downward in the direction of the support9. According toFIG. 2, viewed in the longitudinal direction, the upper end15of the spring element11is disposed slightly more forward than the rear lower end16. The spring element11is formed by tension spring, a leg spring, a torsion spring at the axis14or the like.

So as to avoid noise between the air guide element and the supports9in the extended active position B, interposed contact elements17are arranged on each support9and/or the air guide element4in the contact area10for the air guide element4. The contact elements are made, for example, of a suitable plastic or rubber material. In the retracted position A, the development of noise between the air guide element4and the adjoining vehicle body5is prevented by having additional contact elements18interposed between the recessed accommodation13and the air guide element4.

The adjustment movement of the air guide element4from the inactive position A, in which the upper surface of the outside is flush with the upper body surface, into the active position B occurs during an initial phase of the extension movement of the two supports9, while the adjustment movement of the air guide element4from the active position B into the inactive position B does not occur until an end phase of the retraction movement of the two supports9.

The axis of rotation14and the contact area10are arranged vertically, such that during a driving operation the resultant aerodynamic force FRgenerates a moment MHoldin the contact direction (MHold=FR×L).