Safety in motion - component testing of car seats
C. Rob. Hammerstein (CRH) relies on the S9M force transducer from HBM
Car seats should not only be comfortable and easy to use, but above all they should be safe. Stringent tests and inspections during the development of new car seat models are essential for success in the market. But how can these tests be carried out more efficiently when the range of models and number of variants continues to increase? C. Rob. Hammerstein (CRH), globally leading manufacturer of car seats, has developed a future-proof test concept, trusting in measurement technology from HBM.
When it is about car seat innovations, no-one can best the company CRH. The company, located in Germany, first developed the electrical seat height adjustment back in 1968. Numerous other steps towards more comfort in the car seat followed.
But in addition: The CRH car seats not only became more comfortable, they also became increasingly safer. A high demand that still continues today. In order to achieve the highest of safety standards, the company implements numerous tests and inspections during the development of new components and models.
Easier said than done: Because CRH masters not only the development and production of standard products for mass production, it also carries out special applications for special model variants or series. All seat structures are modular in design - with perfectly matched components.
Efficiency and safety for the function testing of components
With such a variety in the product program and the components used, even a test and inspection program rapidly becomes complex. Does every single component really have to be tested? Does a separate prototype have to be set up for each model variant and then tested in the test bench? Or can the configurations in the technical specifications be tested more broadly?
A question that arises, for example, in the sector of function testing of components for car seats. Instead of setting up an expensive sample for each possible application case, CRH checks the individual components of the car seat before starting construction of a prototype. The prototype is only built and its performance put to the test once the optimal combination has been found.
A preliminary test looks at determining the loading data as they may occur in the actual application case. C. Rob. Hammerstein (CRH) equips a typical seat system with servo motors and strain gages for this purpose. The data obtained from this preliminary test are then used in the test bench.
In the test bench, the test setup consists of the linear drive to be tested and a servo motor that simulates the loading. The servo motor works against the linear drive and simulates the loading for the drive. Load profiles are run in the test to simulate a realistic situation.
Every test bench is only as good as the measurement technology used in it. This is why CRH is using HBM measurement technology. The S9M force transducer is positioned here next to the drive and measures the reaction forces. The results of the target-actual comparison are transferred to a PID controller and the servo motor is correspondingly adjusted.
S9M Force Transducer
The S9M force transducer is available in the accuracy class of 0.02, and with nominal (rated) forces from 500 N to 50 kN. It is made of stainless steel with IP68 protection. The robust transducer can also deliver precise measurement results even in rough environments.
A reliable product for safe developments: So that numerous car drivers can continue to enjoy a safe and comfortable drive in their CRH seat in the future.
"HBM is a respected partner for CRH, delivering high-quality products. The S9M force transducer is a cost-effective measurement tool. We had already had good experiences with the predecessor model, the S9. The decisive points for our application are the low lateral force sensitivity, accuracy, high operating temperature range and the reliability of the S9M. The introduced products function reliably, we appreciate the support and competent advice from HBM."
Horst Schulz, Manager Functional Testing at C. Rob. Hammerstein