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1 概述 气门与气门座是内燃机配气机构七对摩擦副中使用寿命最短的一组摩擦副,它直接影响到配气机构乃至整机的可靠性。因此对这对摩擦副的研究十分重要。 关于这对摩擦副的磨损特点,近年来日益受到人们的重视。资料表明,气门和气门座之间的摩擦是由于接触零件之间的相对位移引起的,其相对位移是由于气门呈撞击性落座时,在气体压力和惯性力的作用下,气门头产生弹性变形的缘故。而进气门的直径较大(刚性差),因此磨损的可能性比排气门大。根据大量的试验表明,气门和气门座在2000小时的内燃机耐久试车中,气门的总下沉量(磨损量)与时间的关系,均经历了“初始磨损阶段——稳定的磨损阶段”,与机械零件正常磨损过程十分相似。因此除了一些特殊情况外,这对摩擦副主要是以滑动的形式磨损。
1 Overview Valve and valve seat is the internal combustion engine gear mechanism seven pairs of friction pair, the shortest service life of a group of friction, it directly affects the reliability of the valve body and even the whole machine. Therefore, the pair of friction research is very important. On the wear characteristics of this pair of friction, in recent years, more and more people’s attention. Data show that the friction between the valve and the valve seat is caused due to the relative displacement between the contact parts, the relative displacement is due to the impact of the valve seat, under the action of gas pressure and inertial force, the valve head produces elastic deformation The reason. The intake valve larger diameter (poor rigidity), so the possibility of wear larger than the exhaust valve. According to a large number of tests, the valve and valve seat in the 2000-hour internal combustion engine durability test, the valve total sinkage (wear volume) and time, have gone through the “initial wear stage - stable wear stage”, and The normal wear and tear of mechanical parts is very similar. Therefore, in addition to some special circumstances, the friction pair is mainly in the form of sliding wear.