18.新的柴油机在低负荷工作时,机油为什么会上窜? 答:柴油机正常运转时,在作功行程,由于燃气压力很大,使活塞环贴紧活塞环槽和缸壁,因而润滑油不会上窜。在排气行程活塞上行时,活塞环因惯性力和摩擦力的作用,其下平面与活塞环槽贴合,上边让开空隙,有向上压挤润滑油的趋势。在进气行程活塞下行时,活塞环因受惯性力和摩擦力的作用,使活塞环上平面与活塞环槽贴合,机油进一步向上环槽引入。压缩行程活塞下行如同排气行程一样,活塞环的下平面与活塞环槽贴合,这样再 18. When the new diesel engine works under low load, why does the oil creep up? A: In the normal operation of the diesel engine, due to the high gas pressure, the piston ring is closely attached to the piston ring groove and the cylinder wall, so the lubricating oil Will not channeling. Piston ring in the exhaust stroke up, the piston ring due to inertial force and friction, the lower plane and the piston ring groove fit, leaving the gap above, the tendency to squeeze up the lubricant. When the piston in the intake stroke descends, the piston ring will fit the plane of the piston ring to the piston ring groove due to the inertia force and the frictional force, and the oil will be further introduced into the annular groove. Compression stroke Pistons down the same line as the exhaust stroke, piston ring under the plane fit the piston ring groove, so again