Friction clutches in electric tailgates are safety-related components in modern vehicles. They prevent the tailgate from closing suddenly in the event of a defect, thereby protecting both people and components from injury and damage.
An important component of friction clutches are friction discs, for example with carbon fiber friction linings. Carbon materials have unique material properties, such as high electrical and thermal conductivity, heat and corrosion resistance, lubricity, and lightness combined with strength. In order to precisely characterize the friction behavior of such components, Hegewald & Peschke has designed a test system that reliably and reproducibly determines the relevant parameters.
Special testing system based on the universal testing machine inspekt table
The testing system is based on an inspekt table universal testing machine with a maximum test force of 5 kN. A torsion module is integrated above the moving crosshead, which applies a torque load to the test piece while simultaneously applying a compressive force via the crosshead. This combination enables a realistic simulation of the mechanical stress on friction clutches.
In a friction clutch, individual friction discs are assembled together. For testing, at least one friction disc and the corresponding counter friction surfaces are placed on top of each other in a special clamping. While the friction disc is mounted so that it can rotate, the counter friction surfaces remain fixed. Under axial load, the friction disc rotates between the support surfaces – the resulting torque is precisely recorded by the LabMaster test software. Thanks to a data acquisition rate of 1 kHz, even very fast torsional movements of up to 1600 rpm can be evaluated accurately.
Simulation of real operating conditions
For testing under realistic environmental conditions, the system is equipped with a temperature control chamber that can simulate temperatures ranging from –40 °C to +120 °C. This allows the friction behavior and stability of the couplings to be examined under realistic thermal conditions.
Flexible parameterization and versatile testing options
The LabMaster test software allows numerous parameters—such as torque, speed, axial force, temperature, direction of rotation, and angle of rotation—to be individually set and controlled. This enables different types of tests to be carried out, e.g., step or continuous running tests, determination of the breakaway torque, or stability tests of the friction connection.
The compact and variable friction test bench can accommodate friction discs of different diameters and friction packages of different thicknesses. Conversion for different friction disc geometries can be carried out quickly and easily in just a few simple steps.
Efficient operation and data analysis
The test bench is operated and programmed using the LabMaster software. The software is ideally suited to this application thanks to its high degree of flexibility and customization options for parameterizing test sequences. Complete test sequences can be conveniently defined using the integrated block program. In addition, the tester has full control over the test sequence by monitoring detailed termination criteria. The block program is always part of LabMaster, so no additional modules need to be purchased for complex tests. The measurement results can be evaluated directly or exported in CSV format for further analysis.
With this testing system, Hegewald & Peschke offers a customized solution for testing safety-relevant clutch components—compact, precise, and application-oriented.
