An Accelerated Test Method for Automotive Wiper Systems

This paper will present an Accelerated testing method, which has been developed for wiper systems. The main objectives are to run the product to failure in a minimal time period and to reproduce the typical life test failures. A better understanding of the correlation between the damage (leading to the defection of the product) and the operating conditions (speed, temperature…) was the basis of this test method. In this paper, the main focus was on the arm and blade sub-system. Field test and Laboratory test data dictate the requirements for the assembly of a test bench. This test bench system allows us to control the influential experimental parameters and occupies a small room area, while testing a large number of samples. The displacement (motion) of the samples is created using pneumatic actuators and the test conditions are computer controlled and monitored. The frequency, the duration, the shaft torque are recorded during the tests. The larger number of samples combined with computer control allowed a statistical treatment of the results and reliable calculations. Two methods have been adapted to ensure the reproduction of the field conditions on the test bench, these are utilization of strain gages and cracking varnish. Strain gages and cracking varnish showed the correlation between stress and effort on a partial car (buck) and on the test bench.