Each Lemförder spare part undergoes a long, complex development process before it gets to market. Take a look at their development department and you will see why their decades of OE experience and state-of-the-art expertise make all the difference.
The preliminary design on the screen kicks off the development of a chassis component. Their experienced engineers create, in collaboration with the vehicle manufacturers, the material requirements, the geometry, the design and the configuration of the mounting points for each component being developed. The expected requirements regarding the acting forces and the available installation space are also factored in, along with the interaction with the directly connected chassis parts. The vehicle manufacturer sets out these parameters in a requirement specification.
The first computer simulations, e.g. FEM strength analyses, are then run. Once these have been successfully completed, the design release feeds into the next step which involves building the initial prototypes.
PROTOTYPING
Initial prototypes are usually milled from a solid block. 3D models provided from Development are prepared accordingly for CNC machining. Here creativity coupled with absolute precision is the order of the day. What hitherto only existed virtually inside the computer is now turned into something real and tangible.
After the part release, the next stage involves producing small quantities from near-production tools (e.g. forged control arms). All individual parts and the preassembled chassis components are measured, the material properties analysed and all functional values checked and documented as per the requirement specification.
The prototypes are then tested in the laboratory and on test vehicles until they finally meet the vehicle manufacturer's requirements and wishes. In this way, over 15,000 prototypes are produced annually. It takes a renowned company that has been operating successfully in the marketplace for many years to shoulder the associated costs.
TEST AND VALIDATION
They achieve their voluntary commitment to maximum quality through the disparate testing procedures, which go way beyond the standards normally found in the market. In addition to extensive studies in their research and development facilities, all LEMFÖRDER products undergo intensive load tests under real conditions. The following critical factors are checked:
Breakaway torque
Rotation and tilting torque
Radial and axial elasticities
Pull-out and press-out strength of the ball stud
Buckling forces
Once certain measured values fall outside the required tolerances, comfort is likely to be severely compromised. The observed physical variables also provide an insight into the wear and safety of the tested parts.
The requirements for these parts have increased significantly over the past few years. That affects both the test methods and the duration of the tests. More and longer tests are conducted. The requirements placed on the products have also increased substantially due to the globalized markets.
For instance, the sealing of the components is tested in the environmental simulation at temperatures ranging from -40°C to +100°C. Apart from pure water, saline water or a concentrated salt solution is also used fortesting.
Similarly, the loads through a car wash (approx. 10 bar) and through a pressure washer (up to 100 bar and 80 °C water temperature) are also simulated.
The system must, on the one hand, be sealed against the water pressure, but, on the other, also be firmly connected mechanically so that the water pressure cannot leverage off the sealing boot.
DRIVING TEST
After validation on the test bench, the final step in the development involves the road test on the automotive manufacturers' release-relevant test tracks. The parts undergo thorough testing with driving tests under disparate road and climatic conditions. All conceivable driving situations, all common road surfaces and the different driving styles are taken into consideration.