Loading patent…
AssigneeFraunhofer-Gesellschaft zur Foerderung der angewandten Forschung
InventorsAndreas Muller, Vatroslav Grubisic, Gerhard Fischer
Estimating the term…
A test rig for testing motor-vehicle assemblies includes a loading device for inducing vertical forces, lateral forces, longitudinal forces and braking or driving forces in the motor-vehicle assembly. The test rig includes a control device for controlling the loading device in such a way as to ensure that the vertical forces, lateral forces, longitudinal forces and braking or driving forces are induced in the motor-vehicle assembly according to a predetermined control loading programme. The control loading programme causes different loading cases of the motor-vehicle assembly, which are realistic in terms of the physics of driving, to be simulated repeatedly in a temporally consecutive sequence. The control loading programme is a standardised basic programme adapted, with the aid of vehicle-and/or axle-specific conversion values and test-rig-specific conversion values, to the given motor-vehicle assembly to be tested in the given case. Preferably, a modifying device is provided for adapting the motor-vehicle assembly to the standardised basic loading programme, whereby the modifying device enables adaptation of the basic loading programme in a particularly uncomplicated manner. The modifying device linearises the suspension spring characteristic of the motor-vehicle assembly.
Test rig for testing motor-vehicle assemblies of the type including spring means under operational loading conditions comprising:
Process for testing motor-vehicle assemblies of the type including spring means under loading conditions of operational type, comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
Gearings; Transmission mechanisms: test-benches with force-applying means, e.g. loading of drive shafts along several directions
Wheeled or endless-tracked vehicles: suspension or damping
Testing static or dynamic balance of machines or structures
Term ended 3 Feb 2013 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The invention relates to a test rig and a process for testing motor-vehicle assemblies, in particular independent wheel suspensions of motor vehicles, under operational loading condition.
Chassis components of motor vehicles such as stub axles, wishbones, tie rods, fastening elements, axle hubs, body components or frame components are, in the course of driving operations, subject to complex, multi-axial stresses. The forces acting on the chassis are vertical forces F.sub.Z, lateral forces F.sub.Y, longitudinal forces F.sub.X and braking or driving forces F.sub.XB, the points of force application are shown in FIGS. 1 and 2 with reference to an automobile.
For different loading cases, the forces listed above differ as regards their relevance (correlation) and frequency. Typical loading cases occurring in the course of motoring operation, which must be taken into account in the process of simulation, are:
The aforementioned and other characteristics and advantages of the invention are described and explained in detail below with regard to certain preferred embodiments of the test rig and the process according to the invention and with reference to the Figures of the drawing;
FIG. 1 shows the point of application and the directions of the lateral force and the vertical force for a front wheel of an automobile;
FIG. 2 shows the points of application and the directions of the longitudinal force, the vertical force and the braking and driving forces acting on the front wheel in FIG. 1;
As shown in the example in FIG. 3, a synthetic loading sequence of operational type includes several different loading types of, in the given case, predetermined duration, which in the present example are designated "rough road", "cornering", "braking" and "rough road, at high frequency" and may also include other loading types such as "accelerating" or may consist of other loading types.
Different loading sequences are in turn combined to form loading blocks which are produced repeatedly.
Irrespective of its special type (loading case), each loading type is generally characterised by the application, during a predetermined time t, to the item to be tested of one or several specific force combinations of vertical force F.sub.Z, longitudinal force F.sub.X, driving or braking force F.sub.XB and lateral force F.sub.Y, said combinations being such as to correspond in the given case to loading cases which are realistic in terms of driving physics. As shown in FIG. 3, individual forces may of course have zero magnitude in any one case. In the following description of the embodiments the item to be tested is assumed to be an independent wheel suspension of a motor vehicle, but the invention is not limited to testing independent wheel suspensions, and the embodiments therefore also apply, in appropriate manner, to the testing of other suitable motor-vehicle assemblies.