Disc springs can handle high forces. Due to their compact design, they also have a small spring travel. They are installed, for example, in automatic clutch systems of commercial vehicles.
ZF Friedrichshafen is one of the largest automotive suppliers in the world and a leading company in the field of driveline and chassis technology. For the expansion of a development centre in Shanghai, the company has acquired a testing machine from Hegewald and Peschke. The testing machine is used for testing disc springs with an outer diameter of up to 385 mm.
Due to the special testing device for disc springs of motor vehicles with integrated spring travel measuring system, the universal testing machine inspekt 100kN becomes a spring testing machine. Three load cells are used to record the forces as single channel and averaged as measured values or to use them as control channel for the disc spring test.
The test system allows different test variants:
1. Checking the actuation travel of the disc spring
- Measurement of the force and the spring travel
- Non-destructive testing during production, random sampling as part of quality assurance
2. Checking the uniformity of the bending of the spring tongues by scanning with a measuring probe. The difference of the spring finger heights is determined. The spring is preloaded three times at the beginning of the test. Then the measuring cycle for determining the hysteresis loop takes place.
The complex test sequences are prepared in the block programme of the LabMaster testing software and stored as a template: Preload, actual load for the measurement and determination of the tongue height. The block programme enables the test to run automatically.