MOTOR VEHICLE COOLANT HEAT EXCHANGER HAVING A WINDABLE COVERING SYSTEM HAVING A MODIFIABLE WINDING SPEED, AND PULLING MEANS ADAPTEN THERETO

Abstract

A motor vehicle coolant heat exchanger having a modifiable covering system includes a support, a winding shaft mounted rotatably around a winding axis, a rotational drive, a roller-blind web, at least one pulling means winding body connected to the winding shaft to rotate together, and a pulling means. The roller-blind web is windable onto and unwindable from the winding shaft along a winding trajectory, which comprises a pulling crosspiece at its longitudinal end region located remotely from the winding shaft. The pulling means is unwindable from and windable onto the pulling means winding body parallel to the winding trajectory, which is connected at its longitudinal end remote from the pulling means winding body to the pulling crosspiece. The pulling means is guided around a deflection roller in such a way that its longitudinal end connected to the pulling crosspiece moves away from the winding shaft while it is being wound on.

Claims

1. A motor vehicle coolant heat exchanger having a modifiable covering system for modifying an air flow-capable cross section of the motor vehicle coolant heat exchanger, comprising: a support stationary relative to the radiator heat exchanger; a winding shaft mounted on the support rotatably around a winding axis; a rotational drive, mounted on the support, for driving the winding shaft to rotate around the winding axis; a roller-blind web, windable onto and unwindable from the winding shaft along a winding trajectory, which is connected to the winding shaft at its one longitudinal end region with respect to the winding trajectory, and comprises a pulling crosspiece at its other longitudinal end region located oppositely with respect to the winding trajectory; at least one pulling means winding body that is connected to the winding shaft for rotation together; and a pulling means that is unwindable from and windable onto the pulling means winding body parallel to the winding trajectory, the pulling means being connected at one end to the pulling means winding body and at the other end to the pulling crosspiece, the pulling means being guided, in its extent between the pulling means winding body and the pulling crosspiece, around a deflection roller in such a way that that longitudinal end of the pulling means which is connected to the pulling crosspiece moves away from the winding shaft while it is being wound on, the pulling means and the roller-blind web being connected for a winding motion counter-directionally with their respective winding body, namely the pulling means winding body and winding shaft, so that the pulling means is unwound from the pulling means winding body while the roller-blind web is wound onto the winding shaft, and vice versa, the winding radius of the pulling means winding body changing in a winding portion, along its axial extent, in such a way that during a rotational motion of the pulling means winding body in the pulling means winding-on direction, the length of a pulling means portion, wound on in successive rotational portions of the pulling means winding body which have the same rotational angle magnitude, decreases.

2. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1, wherein the winding portion of the pulling means winding body tapers conically in its axial direction.

3. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 2, wherein the winding portion of the pulling means winding body comprises a helical groove in which the pulling means is received in the wound-on state.

4. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 3, wherein the magnitude of the change in the winding radius of the helical groove per turn differs from the thickness of the roller-blind web by no more than 10%.

5. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1, wherein the pulling means winding body is located in the torque transfer path for transferring drive torque from the rotational drive to the winding shaft.

6. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 5, wherein a torque output part of the rotational drive is coupled in torque-transferring fashion to the pulling means winding body.

7. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1, wherein a respective pulling means winding body, having a respective pulling means, is connected to the winding shaft axially on both sides of the roller-blind web for rotation together around the winding axis.

8. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1, wherein the support comprises two guide rails, extending parallel to the winding trajectory and arranged with a distance from one another parallel to the winding axis, which each guide an edge portion, extending along the winding trajectory, of the roller-blind web during the winding and unwinding motion of the roller-blind web.

9. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1, wherein the winding trajectory extends parallel to a flow incidence side of the motor vehicle coolant heat exchanger.

10. A vehicle, having a motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 1.

11. The motor vehicle coolant heat exchanger, having a modifiable covering system, according to claim 3, wherein the magnitude of the change in the winding radius of the helical groove per turn differs from the thickness of the roller-blind web by no more than 5%.

Description

[0039] The present invention will be explained in more detail below with reference to the appended drawings, in which:

[0040] FIG. 1 is a schematic plan view, in a flow incidence direction, of an embodiment according to the present invention of a motor vehicle coolant heat exchanger having a modifiable covering system in accordance with the present Application; and

[0041] FIG. 2 is a side view of the motor vehicle coolant heat exchanger having a modifiable covering system of FIG. 1.

[0042] In FIGS. 1 and 2, an embodiment according to the present invention of a system for covering a motor vehicle coolant heat exchanger 11 is labeled generally as 10. FIG. 1 shows the embodiment as viewed in a flow incidence direction D (see FIG. 2), and FIG. 2 shows the embodiment as viewed along winding axis W in the direction of arrow II in FIG. 1. The illustrations are not to scale.

[0043] The embodiment encompasses a support 12 having, for example, a bottom plate 14 as well as two guide rails 16 and 18. Also provided on the bottom plate is a delimiting bar 20 that delimits a flowthrough opening 22 surrounded by support 12, more precisely by guide rails 16 and 18, and by delimiting bar 20. Bottom plate 14 does not need to be a plate. It can also be merely a bar or the like. Motor vehicle coolant heat exchanger 11, which is merely indicated with dashed lines in FIG. 1, is located behind flowthrough opening 22 in flow incidence direction D.

[0044] The embodiment furthermore comprises a winding shaft 24 mounted, rotatably around a winding axis W, directly or indirectly on support 12, onto which shaft a roller-blind web 26 is windable along a winding trajectory B. Roller-blind web 26 is also unwindable from winding shaft 24 along winding trajectory B. Flowthrough opening 22 is not obligatorily necessary. In order to achieve the advantages of the present invention it is sufficient if roller-blind web 26 is movable along a flow incidence surface 11a of motor vehicle coolant heat exchanger 11.

[0045] At its longitudinal end located closest to winding shaft 24, roller-blind web 26 is connected to winding shaft 24, for example, by adhesive bonding and/or clamping and/or riveting, to name only a few possible examples.

[0046] At its longitudinal end located remotely from winding shaft 24 along winding trajectory B, roller-blind web 26 comprises a pulling crosspiece 28 that projects on both sides beyond roller-blind web 26 in an axial direction with respect to winding axis W. Pulling crosspiece 28 is received in positively engaging fashion in an end-located loop 30 of roller-blind web 26 along winding trajectory B. Loop 30 can be formed by folding over roller-blind web 26 and stitching and/or adhesively bonding it.

[0047] Provided on both axial sides of winding shaft 24 is a respective pulling means winding body 32 and 34 that is embodied mirror-symmetrically with respect to a mirror symmetry plane orthogonal to winding axis W and thus to the drawing plane of FIG. 1. Because of the symmetry condition indicated, it is sufficient to describe only pulling means winding body 34, the description thereof serving also, given the symmetry condition indicated, to describe pulling means winding body 32.

[0048] A cable 36, constituting an example of a pulling means, can be wound onto and unwound from pulling means winding body 34. Pulling means winding body 34 rotates together with winding shaft 24 around winding axis W constituting a common rotation axis. Cable 36 is connected, at its longitudinal end located remotely from winding body 34, to that longitudinal end of pulling crosspiece 38 which is located axially closer to winding body 34. Between pulling crosspiece 28 and winding body 34, cable 36 runs around a deflection roller 38 that is provided rotatably on support 12 (here, on bottom plate 14).

[0049] A winding portion 40 of pulling means winding body 34 is embodied in conically tapering fashion. Winding axis W, constituting the rotation axis of pulling means winding body 34, forms the cone axis of winding portion 40.

[0050] For defined arrangement of the wound-on longitudinal portions of cable 26, a helical groove 42, in which cable 36 abuts against winding body 34 upon winding, is embodied on the conical winding portion 40 of pulling means winding body 34.

[0051] The difference in radius between two immediately axially adjacent turns of helical groove 42 corresponds to thickness d of roller-blind web 26 (see FIG. 2).

[0052] In FIG. 2 the viewer is looking along arrow II of FIG. 1 toward covering system 10 and thus toward pulling means winding body 32. The helical groove also provided thereon is labeled 42 as it is on winding body 34. Groove 42 is indicated in FIG. 2, however, only by a single line and not, as in FIG. 1, by two parallel lines. The pulling means (cable) connected to pulling means winding body 32 is again labeled 36.

[0053] As is evident especially from FIG. 2, cable 36 and roller-blind web 26 are wound counterdirectionally around winding axis W, i.e. when roller-blind web 26 is unwound from winding shaft 24, cable 36 is simultaneously wound onto pulling means winding bodies 32 and 34, and vice versa.

[0054] A rotational drive 44 is directly connected to pulling means winding body 34 arranged on the right in FIG. 1. An output shaft 46 of the rotational drive is arranged coaxially with pulling means winding bodies 32 and 34 and with winding shaft 24, and is coupled directly for rotation together, preferably by positive engagement, to that longitudinal end region of pulling means winding body 34 which is located remotely from winding shaft 24. Torque outputted from rotational drive 44 via its output shaft 46 is thus transferred via pulling means winding body 34 to the winding shaft. Rotational drive 44 is drivable in opposite rotational directions so that roller-blind web 26 can be wound onto winding shaft 24, and unwound from it, in motorized fashion. Roller-blind web 26 can be steplessly unwound from, and wound onto, winding shaft 24. A flow incidence surface 11a of motor vehicle coolant heat exchanger 11 can thereby be steplessly covered by roller-blind web 26.

[0055] In contrast to what is depicted in FIGS. 1 and 2, winding shaft 24 is preferably arranged above radiator 11 so that roller-blind web 26 can be guided past flow incidence surface 11a at the closest possible distance parallel to flow incidence direction D upon unwinding.

[0056] The (preferably electric) rotational drive 44 is operated at a constant rated rotation speed while delivering a rated torque.

[0057] For a constant rotation speed of output shaft 46, the speed of pulling crosspiece 28 along winding trajectory B depends on the winding radius of the assembly constituted by winding shaft 24 and roller-blind web 26 wound onto it. The larger the winding radius, the more quickly pulling crosspiece 28 moves along winding trajectory B when rotationally driven at a constant rotation speed. This means that pulling crosspiece 28 becomes increasingly slower as roller-blind web 26 unwinds from winding shaft 24, and increasingly faster upon winding on.

[0058] In order to allow this change in speed as a function of the winding state of roller-blind web 26 also to be achieved with cables 36, winding portions 40 are embodied with the above-described conicity. For the reason recited, the winding radius of helical groove 42 differs, between immediately adjacent turns, by approximately the thickness d of roller-blind web 26. It is thereby possible to ensure that the sum of the unwound lengths of roller-blind web 26 on the one hand and of a cable 36 on the other hand is approximately constant over the operating states achievable as intended for occluding flow incidence surface 11a. Cables 36 can thus assist an unwinding motion of roller-blind web 26 by exerting a pulling force along winding trajectory B in a direction away from winding axis W, and can thus prevent roller-blind web 26 from canting upon unwinding. The winding of roller-blind web 26 onto winding shaft 24, conversely, is very largely non-critical.

[0059] As is evident from FIG. 2, a guide rail 16 encompasses two rail bodies 16a that form a gap 48 between them. Gap 48 passes completely through guide rail 16 in an axial direction, i.e. parallel to winding axis W, and is delimited by rail bodies 16a in a direction orthogonal to winding axis W and to winding trajectory B. Guide rail 18 is embodied mirror-symmetrically with respect to guide rail 16 with reference to a mirror symmetry plane orthogonal to winding axis W.

[0060] Rotational drive 44 can be connected to a vehicle controller 50, for example a microcomputer, that receives from sensors 52 operating information regarding vehicle 54 having covering system 10, for example regarding the coolant temperature of an internal combustion engine of vehicle 54.

[0061] As a function of the information received from sensors 52, vehicle controller 50 can apply control to rotational drive 44 to rotationally drive winding shaft 24 in order thereby, as a function of the operating state, to uncover or block flowthrough opening 22 in terms of a flow of convective cooling air, and thereby to allow flow incidence surface 11a of motor vehicle coolant heat exchanger 11 to be steplessly covered or not covered.