一、排气门弹簧为何连续折断四次 一台配装S195型柴油机的小四轮拖拉机,连续折断排气门外弹簧四次,而且每次工作都不到一个班次就折断了。开始怀疑新换上的弹簧质量有问题,就将原进气门弹簧装到排气门处,结果工作不到一个班次,排气门弹簧又折断了。经仔细检查发现,排气门弹簧与缸盖接触平面有轻微锈蚀,并有小水珠。原来是缸盖上有一未透的铸造小气孔。机手在第一次更换弹簧时, First, why the exhaust valve spring break four times in a row S195 equipped with a small four-wheel tractor diesel engine, continuous break off the exhaust valve outside the spring four times, and each work less than a shift on the break. Start to suspect the new spring quality problems, the original intake valve spring loaded to the exhaust valve, the result of less than a shift, the exhaust valve spring and broken. After careful examination found that the exhaust valve spring and cylinder head contact surface with a slight corrosion, and a small drop of water. Turned out to have a cylinder head is not through the casting of small pores. The first time in the spring to replace the spring,