1.开发目的汽车发动机的气门机构零件是在非常严酷的条件下工作,所以要求具有较高的可靠性。其中凸轮及摇臂的滑动接触部位表面压力高,多采用耐滑动磨损的激冷铸铁凸轮轴。为了减少滑动阻力,降低燃料费用,研究用滚柱轴承代替以往的滑动接触方式,此外,作为对凸轮特性的要求,滚动疲劳强度更加重要。因此,注意到ADI(奥氏体等温淬火球铁)优异的疲劳特性,以提高可靠性和降低成本为目的,对ADI的适用性进行 1. The purpose of development Valve components of automotive engines are working under very harsh conditions, so require high reliability. One of the cam and rocker sliding contact surface pressure is high, and more use of sliding wear-resistant chilled cast iron camshaft. In order to reduce the sliding resistance, reduce fuel costs, the use of roller bearings instead of the traditional sliding contact method, in addition, as a cam characteristics, rolling fatigue strength is more important. Therefore, noting the excellent fatigue properties of ADI (austempered isothermal quenched ductile iron), the suitability of ADI for reliability and cost reduction