IABG commissions the new automatic half-axle test bench (AHAP) for testing spring and shock absorber systems. We now have a total of four spring and shock absorber test benches in our test centre for air springs and shock absorbers at the headquarters in Ottobrunn.
The automatic half-axle test bench enables us to test shock absorbers and spring and shock absorber systems under realistic conditions. At variable ambient temperatures of between -40°C and +100°C, biaxial excitation is applied through compression and steering angle with the original kinematics of a half axle in real time. Optional water cooling of the shock absorbers dissipates the heat generated. This makes it possible to run continuous tests without having to stop for cooling, which reduces the overall testing time.
The effective interior dimensions of the test chamber are L x W x H [mm] = 720 x 720 x 1,300, which provides ample room for a standard car half axle whose connecting rods are attached to the test bench with special adapters. The test chamber has ducts for actuators, compressed air and water cooling, as well as for control and sensor cables. Even complex active systems can be subjected to functional and fatigue strength tests.
Digital control channels permit transmission of separate, synchronised test signals for compression and steering angle. Tests on modern active spring and shock absorber systems are usually made with real-time signals based on driving test measurements or simulation calculations with superimposed temperature cycles. However, special issues can also be addressed by generating synthetic signals to determine characteristics under different operating conditions.
Both the setting and the automatic control and readjustment of the static preload of air spring elements are made via a controlled compressed-air supply integrated in the facility control system. Controlled energisation of active elements is also possible for testing active spring and shock absorber systems. This equipment also permits you to provoke realistic reactions even in complex suspension systems thus ensuring reliable testing. The table below illustrates the mechanical performance characteristics of the AHAP test bench.
| Compression | Steering angle | |
|---|---|---|
| Maximum static load | +/- 100 kN | +/- 10 kN |
| Maximum dynamic load | +/- 80 kN | +/- 8 kN |
| Maximum stroke | +/- 125 mm | +/- 50mm |
| Maximum piston speed | +/- 3 m/s | +/- 0,5 m/s |
Table: Key performance figures of the AHAP automatic half-axle test bench
During testing, the paths, forces, pressures and temperatures the test item is subjected to can be continuously measured, monitored and if necessary, recorded. These variables also serve as switch-off criteria if, for example, it is necessary to interrupt testing if there is change in the system behaviour and an inspection has to be carried out.
The AHAP automatic half-axle test bench extends the IABG portfolio in the field of testing air springs and shock absorbers of active systems. Realistic testing of spring and shock absorber systems in axle setups has a firm place in development and approval testing, especially of active systems. For many years, our air spring and shock absorber test centre has been an integral part of the testing processes of major systems suppliers for premium automotive manufacturers.
Test benches are designed and made completely by IABG and serve as yet another outstanding example of our service portfolio for the development, modernisation, operation and support of test systems. Our daily practical experience in testing flows directly into the task-oriented development of our test systems. In this way, we consistently meet our customers' constantly growing demands.
