活塞在柴油机燃烧一膨胀行程的高温高压作用下在缸套内作高速往复运动，若因剧烈爆震摩擦等原因而导致缸套内壁被拉伤、出现金属剥落及竖向沟槽并影响柴油机的正常工作，则称拉缸。此时，燃烧室内的高温高压气体向油底壳下窜，迫使机油外泄或烧损，同时造成发动机启动困难、功 Pistons in the diesel engine combustion an expansion stroke under the action of high temperature and pressure in the cylinder for high-speed reciprocating motion, if due to severe detonation friction and other reasons led to the inner cylinder wall is strained, there are metal spalling and vertical groove and affect the diesel engine Normal work, then pull cylinder. At this point, the combustion chamber under the high temperature and pressure gas channeling to the oil pan, forcing oil leakage or burning, while causing the engine start difficult, work