New technologies for engine valve springs became necessary to meet car manufacturers' increasing requirements for a reduction of fuel consumption. The valve spring design influences fuel consumption through the required spring loads and installation heights. Therefore increased fatigue strength as well as optimized design were the target of investigations.
A CrSi alloyed wire increases the fatigue strength as long as the specific requirements of high-tensile materials are considered. Furthermore non-cylindrical spring contours and ovate wire cross sections are able to reduce spring loads and installation heights. At the same time minimum failure rates are ensured.