短语词组短语valve -opening pressure 气门开启压力;活门打开压力Intake valve -opening time 进气持续角Exhaust valve -opening time 排气持续角relief -valve opening 释放阀启开injection -valve opening pressure 喷油阀开启压力full -opening valve 全径阀门;敞开阀;全径阀 返回 valve opening