柴油机气门座圈在工作中由于承受高温、高压气体和连续冲击载荷的作用,特别容易发生故障。其工作锥面往往出现麻点、凹坑、金属剥落、座圈缩短和磨损变宽等现象,造成气门关闭不严,缸压下降,柴油机动力不足。如果气门在气门座圈上的凹陷深度大于其使用极限值,经更换加厚气门后,若仍不符合规定或座圈发生严重烧蚀、松动和裂纹时,必须更换气门座圈。 Diesel valve seat in the work due to withstand high temperature, high pressure gas and continuous impact load, particularly prone to failure. Its working cone often appear pitting, pits, metal spalling, seat shortening and wear broadening and other phenomena, resulting in lax valve closure, cylinder pressure drop, lack of diesel power. If the depth of the valve on the valve seat is greater than the limit of its use, after replacing the thickened valve, the valve seat must be replaced if it still does not meet the requirements or the seat is severely ablated, loosened or cracked.