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汽车大修热试或行驶中,常常会出现气门挺杆响,若不及时消除,将会造成凸轮不正常磨损,挺杆损坏,影响发动机正常工作。气门挺杆响情况较复杂,除因气门挺杆与挺杆孔配合松旷外,发响的挺杆多数是转动不正常、不转或摆动。拆检时发现下列各种现象: 1.凸轮及挺杆球面硬度较低,造成严重磨损,尤以凸轮尖部最重。2.气门挺杆球面弧度不对,凸轮轮廓不标准,凸轮锥度不正确,光洁度低,挺杆球面与凸轮接触不均匀,其表面有拉伤痕纹及烧蚀、熔焊现象。3.气门挺杆杆部与挺杆孔配合松旷,光洁度低,精度低,失圆及锥度过大。4.气门弹簧过硬。5.润滑油使用不适当。为了消除上述不正常现象,必须掌握凸轮轴及气门挺杆的技术条件及合理的修理工艺,
Car overhaul hot test or driving, valve tappets often appear, if not promptly eliminated, will result in abnormal cam wear, tappet damage, affecting the normal operation of the engine. Valve lifter ring situation is more complicated, except for the valve lifter and tappet hole with Song Kuang, the majority of the sounding tappet rotation is not normal, do not turn or swing. Disassembly found the following various phenomena: 1. Cam and tappet lower spherical hardness, causing serious wear and tear, especially the most severe cam tip. 2. Valves tappet spherical curvature is not correct, the cam profile is not standard, the cam taper is not correct, smooth finish, tappet spherical and uneven contact with the cam, the surface of the scar pattern and ablation, welding phenomenon. 3. Valve tappet rod and tappet hole with Songkuang, low finish, low accuracy, loss of roundness and taper is too large. 4. valve spring is too strong. 5. Lubricant is not used properly. In order to eliminate the abnormal phenomenon, we must master the technical conditions of the camshaft and valve lifter and reasonable repair process,