Drive arrangement for a motor vehicle roof element which can be swiveled into a stowage space in the vehicle for deposition

A drive arrangement for a motor vehicle roof with a movable roof part (14) which is connected to a carrier element (11, 111, 225) which can be displaced by a drive element (5, 19, 220) along a given path of motion (8, 219), the drive element (5, 19, 220) engaging a intermediate pivot lever (12, 112, 221) which applies the drive force applied by the drive element (5, 19, 220) via a driver (6, 244) to the carrier element (11, 111, 225) depending on the pivot position of the intermediate lever (12, 112, 221), and the drive arrangement is constructed such that the pivot position of the intermediate lever (12, 112, 221) is determined by the position of the carrier element (11, 111, 225) along the path of motion (8, 219).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a drive arrangement for a motor vehicle roof element which can be swiveled into a stowage space for a motor vehicle for deposition, especially for a convertible top.

2. Description of Related Art

German Patent DE 195 25 587 C1 discloses a drive arrangement for a convertible top which can be lowered into a rear convertible top compartment by means of a four-bar mechanism, one of the two connecting rods of the four-bar mechanism arrangement being provided on its end which is permanently coupled to the body with a worm wheel which is driven by a worm which is driven by a compressively stiff drive cable in order to cause a swinging motion of the convertible top into or out of the convertible top compartment.

The disadvantage in this known drive arrangement is the application of force which is constant due to the structure during the swinging process.

SUMMARY OF THE INVENTION

The primary object of this invention is to devise a drive arrangement in which the application of force during the adjustment process can be made variable with simple means.

This object is achieved in accordance with the invention by a drive arrangement for a motor vehicle roof with a movable roof part which is connected to a carrier element which can be moved by means of a drive element along a given path of motion, the drive element engaging an intermediate pivot lever which applies the drive force applied by the drive element via a driver to the carrier element depending on the pivot position of the intermediate lever. Furthermore, the drive arrangement is made such that the pivot position of the intermediate lever is determined by the position of the carrier element along the path of motion.

In this approach according to the invention, it is advantageous that the application of force during the displacement process can be made variable with simple means, especially with few components, in order to increase or decrease the application of force, for example, in the area before reaching the end position.

The invention is described in detail below with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1schematically shows a drive arrangement for a roof cassette14of an openable motor vehicle roof30(seeFIG. 5) according to a first embodiment. The roof cassette14is used to hold an openable roof element31such as, for example, a folding roof (seeFIGS. 5 & 6) or a louvered roof. Here, the openable roof element31, which closes the roof opening32flat in its closed position, is pushed by means of a drive (not shown) along lateral guides33into the roof cassette (14) in order to clear the roof opening32, this process also being possible when driving. The roof cassette14can, for its part, be swung, by means of the drive arrangement described below, for deposition in a rear stowage space34of the motor vehicle35, especially behind the seats, to completely remove the motor vehicle roof30in the manner of a convertible. The roof cassette14is pivotally mounted on the body via two schematically shown mounting elements17,18which are connected via hinges3,4to two carrier elements10,11which, for their part, are each pivotally supported at coupling points formed at hinges2,1mounted stationary on the motor vehicle body (see FIG.7). The hinges1,4;2,3are located on the opposing ends of the carrier elements11,10. The carrier element11acts as a driven connecting rod. The carrier elements10,11with the hinges1,2,3,4form a four-bar mechanism arrangement for a roof cassette14by which this roof cassette can be lowered into the stowage space34.FIG. 7shows the carrier elements10,11and the roof cassette14in the intermediate position when the roof cassette14is lowered.

The connecting rod11in the lengthwise direction is provided with a guide path13into which a driver pin6which is made on the intermediate lever12fits. The intermediate lever12on its two ends is provided with a slider5,7which fits into a body-mounted guideway8,9and is guided to slide in it. Thus, the driver pin moves essentially parallel to the longitudinal direction of the connecting rod11, while the slider5,7moves crosswise relative thereto so that the movement of the driver pin6is essentially perpendicular to the movement of the slider5,7relative to connecting rod11. A compressively stiff drive cable19which is driven by a drive which is made in the conventional manner (via a pinion which is driven by an electric motor) engages the slider5which lies radially to the outside with respect to the pivot1of the connecting rod11. The radially outside guideway8for the slider5is made circular in this embodiment. The inner guideway9which lies radially inside for the slider7runs via wide sections essentially parallel to the outside guideway8, i.e., it is made likewise circular over significant sections. In the end area20of the inner guideway9, however, its radius is greatly reduced so that the distance between the guideways8,9in this area increases greatly. It is noted that, slider5together with drive cable19serve as a drive element for the connecting rod11, connecting rod11constituting a carrier element for the movable roof part14.

If force is applied to the outer slider5in the direction of the arrow from the position shown inFIG. 1by means of the drive cable19, by engagement of the driver6which is located between the two sliders5,7the connecting rod11is forced into a pivoting motion clockwise, then the slider6,7being guided in the guideways8,9. As long as the distance between the guideways8,9is constant, force is applied to the connecting rod11via the driver6always at the same location, i.e., at a constant drive force of the drive cable19the drive force applied to the connecting rod11is likewise constant. In the area of the constant interval the guideways8,9can also be made such that they are on top of one another, i.e., do not have any interval.

But, if the slider7travels into the end area20of the inner guideway9in which its radius decreases, the distance between the guideways8,9increases and the intermediate lever12necessarily executes clockwise rotational pivoting motion about the drive element5, since the slider7moves to the inside along the inner guideway9. In doing so, the driver6slides in the guide slot13of the connecting rod forming the carrier11to the inside, viewed in the radial direction. The rotary motion of the intermediate lever12at the same drive speed of the driven slider5leads to the pivoting motion of the connecting rod forming the carrier11about pivot1slowing down. Accordingly, with a uniform driving force of the drive cable19, the drive force applied to the connecting rod11for the roof cassette14increases. Therefore, in the end area20of the inner guideway9, stepping down of the driving motion takes place.

The drive motion can be stepped up and the drive force reduced by the distance between the two guideways8,9being reduced by, for example, the radius of the inner guideway9being increased.

Basically, it is possible, since for force transfer only the distance between the two guideways8,9is important, instead of the inner guideway9, to provide the outer guideway8with a variable radius. However, since the drive cable runs19runs in this outer guideway8, it is generally preferred that, as shown, the inner guideway9is made with a changing radius.

An increase or decrease of the drive force can be desirable not only in the area of the end position of the roof cassette14, but under certain circumstances, also in intermediate positions.

FIG. 2schematically shows a second embodiment of the invention, the essential difference being that, in contrast to the embodiment fromFIG. 1, the radially inside guideway9and the inner slide7of the intermediate lever12, which slide is guided in the latter, are omitted. The dependency of the radial position of the inner end107of the intermediate lever112, i.e., the end nearer the pivot1of the connecting rod111, on the pivot position of the connecting rod111is achieved by means of a lock119in interplay with a body-mounted stop118and a body-mounted sliding cam117.

The intermediate lever112, which is made as a toggle lever, is driven on its radial outside slider5by a compressively stiff drive cable19in a body-mounted circular guideway8which has the rotary axis1of the connecting rod111as the center point. The force is applied to the connecting rod111as in the aforementioned embodiment by means of a driver6which is made on the intermediate lever112and which fits into a guideway113which is made in the connecting rod111essentially in the radial direction.

The lock119can be moved in the connecting rod111in an essentially tangential direction, its being pre-tensioned by means of a compression spring116into a position (seeFIG. 2) in which it forms a contact surface120for the inner end107of the pivot lever112in the radial direction. In this way, in the position of the connecting rod111shown inFIG. 2, the radially inner end107of the intermediate lever112is prevented from moving in the radial direction to the inside; together with the engagement of the driver6in the guideway113, this provides for fixing of the intermediate lever112relative to the connecting rod111. In this position, thus, at a constant drive speed and drive force, the connecting rod111moves with a constant speed and constant force via the drive cable19and the outer slider5. In the embodiment ofFIG. 1, this state corresponds to the area in which the two guideways8,9run with a constant distance between them, i.e., concentrically.

The sliding cam117and the stop118lie in different planes, the stop118being located such that with the corresponding angular position of the connecting rod111, the lock119with its front end121runs against the stop118and then is pushed back accordingly against the pre-tensioning force of the compression spring116in the tangential direction. In this way, the contact of the radially inside end107of the intermediate lever112with the contact surface120of the lock119which points radially to the outside is ended, by which the end107is released. The sliding cam or the sliding cam element117is made such that, after the lock119is pushed back by the stop118, the radially inside end107of the intermediate lever112makes contact with the contact surface122of the sliding cam element117, by which the radial position of the inner end107of the intermediate lever112is now determined by the shape of the contact surface122. It is shaped as shown inFIG. 2such that the inner end107of the intermediate lever112, as the pivoting motion of the connecting rod111continues around the axis1of rotation in the direction of the arrow, i.e., clockwise, can move radially to the inside; in interaction with the guide of the driver6in the guide slot113of the connecting rod111and the continued constant application of force to the slider5leads to a rotational pivoting motion of the intermediate lever112clockwise. The shape of the contact surface122of the sliding cam element117corresponds to the shape of the inner guideway9fromFIG. 1in its end area20.

The rotational pivoting motion of the intermediate lever112achieved thereby, in the embodiment as shown inFIG. 2, has the same effects as in the embodiment as shown inFIG. 1, i.e., the pivoting motion of the guide rod111slows down while the force accordingly increases so that stepping-down of the drive motion of the connecting rod111takes place in the end region of the pivoting area.

One advantage of the embodiment as shown inFIG. 2is that the inner guideway of the embodiment as shown inFIG. 1can be omitted for the most part, i.e., with the exception of the sliding cam element117; this can lead to advantages in terms of construction space and/or costs. Nonetheless, the movement of the driver pin6is still essentially perpendicular to the movement of the slider5,7relative to connecting rod111.

Even if the invention so far has been described with reference to a drive provided with a drive cable, the application of the driving force to the intermediate lever12,112is fundamentally possible in a different manner, for example, by means of a drive rod.

This invention is not limited to the drive of a connecting rod, i.e., a lever which is pivotally coupled to the body on one end, but the adjustable roof parts can in general be driven along a given path of motion, as is shown inFIGS. 3,4for a slider plate225as the driven roof part to which, for example, the roof tip of a folding roof guided on roof-mounted guides is attached.

The slider plate225is guided by a guide means which is not shown along a body-mounted guideway, for example a guide rail, on a stipulated path219of motion. This example is a linear section; the path of motion or the guide rail219could also be curved if necessary.

The slider plate225can also be, for example, a driven element of the roof mechanism for a folding roof, a convertible top, a sliding roof, a sliding and lifting roof, a louvered roof or a spoiler roof.

A compressively-stiff drive cable (not shown) which is driven preferably via a pinion by the electric motor runs in a cable channel228and is rigidly connected to a slider220which is guided in the cable channel228and is connected via a hinge222to one end of an intermediate lever which is made as a toggle lever221. The other end of the toggle lever221is guided via a slider230which is connected via a hinge223in the guide channel229. Between the hinges222,223, the toggle lever221has a driver224which is made as a guide pin and which fits into a guide slot226which is made in the slider plate225. The crank slot226, as necessary, can be made straight or curved. In this example, it is made straight and runs perpendicular to the direction of motion219of the slider plate. In this embodiment, the slider220and the drive cable form a drive element acting on the driver224to move the carrier element formed by the slider plate225based on the position of the intermediate lever formed by toggle lever221.

Aside from the cam area labeled with reference number227, the guide channel229for the slider230runs straight and parallel to the guide channel228for the slider220. The guide channel228runs straight over its entire illustrated length. In the parallel area, the guide channels228,229run essentially over one another so that the toggle lever221in this area, as shown inFIG. 3, lies essentially horizontal. In the curved section227, the guide channel229runs away from the guide channel228, i.e., the distance between the guide channels228,229increases.

The drive force imparted by the drive cable is applied to the slider plate225via the slider220, the toggle lever221and finally the driver224. In the position shown inFIG. 3, in which the two sliders220,230are located in the straight area of the guide channels228,229, the application of force is constant at a constant driving force of the drive cable.

However, as soon as the slider230enters the curved area227of the guide channel229, the toggle lever221is forced into pivoting motion around the hinge222of the slider220, by which the driver224in the crank slot226slides down. As a result of this swivelling motion of the toggle lever221, at a constant speed of the slider220, the motion of the driver224slows down (i.e., the corresponding motion component decreases) and as does the slider plate225in the direction219at the same time; this causes a corresponding increase of the driving force with respect to the direction219. In this way, stepping-down of the drive motion in the direction210is achieved in the direction210in the area of the curved section227of the guide channel229.

The step-up ratio is determined on the one hand by the dimensioning of the toggle lever, i.e., the ratio between the distance b between the hinge222and the driver224and the distance a between the driver224and the hinge223, and on the other hand, by the configuration of the curved section227of the guide channel229, and can be adjusted accordingly via these parameters for the respective application.

The application of a driving force to the slider plate225depends on the pivot position of the toggle lever221which, in turn, depends on the position of the slider plate225along its path of motion. In this way, application of the driving force which is variable as necessary is enabled.

Instead of being determined by means of engagement of the slider230in the guide channel229, the pivot position of the toggle lever221can also be determined, as in the embodiment shown inFIG. 2, by a lock element which is actuated, for example, by a stop depending on the position of the slider plate225, and which, in the unactuated state, forms a contact surface for the guide point of the toggle lever221which corresponds to the slider230. In this modification, the guide channel229can be completely eliminated at least with respect to its straight section, and the curved section can be replaced by a curved contact surface, as in FIG.2.

In principle, this invention enables any adjustable, variable application and step-up/step-down of the drive force with a reliable mechanical embodiment and with low construction space requirement.