收割机在作业中如果突然出现割台升降失灵 ,而转向正常 ,故障的原因可能是多路换向阀内的节流孔堵塞。排除方法为 :拆开回油阀 ,取出中心圆柱体 ,用细钢丝将节流孔捅通 ,安装复位即可继续作业。预防措施 :班次保养时 ,放出液压油 ,用柴油清洗油道 ,如果原机油没有老化变质 ,过 Harvester in the job suddenly if the header lift failure, and turn to normal, the failure may be caused by multi-way valve throttle orifice blockage. Exclusion method: open the oil return valve, remove the center cylinder, with fine steel wire will be stabbed through the orifice, installation reset to continue working. Preventive measures: shift maintenance, the release of hydraulic oil, diesel oil wash, if the original oil is not aging deterioration, too