ИЗ ОПЫТА ЭКСПЛУАТАЦИИ АВТОБУСОВ ЛИАЗ 529222

Abstract

With a slight mileage of buses of the Likinsky Bus Plant, the engines alternately began to fail with the destruction of cylinder blocks and pistons, the occurrence of compression rings. (Research purpose) The research purpose is searching out for the causes of increased engine oil consumption and emergency failure of foreign-made internal combustion engines. (Materials and methods) The D0836LOH65 engine was chosen as the object of research. We studied the geometry and hardness of oil-removing piston rings. We used a Digital Micro microscope with magnification up to 400x and an electronic hardness tester in accordance with the recommendations of the regulatory and technical documentation. (Results and discussion) It was established by visual inspection that there is uneven wear on the working surfaces of the oil-removing piston rings, and defects in the form of porous formations on the end ones. Wear was recorded in the upper part of the cylinders with the formation of a ledge, black carbon deposits appeared on the bottoms and on the heat belt of the pistons, small longitudinal scratches appeared on the skirts of the pistons. Damage to the inserts has a form characteristic of working in the so-called oil starvation mode. It was determined that the cause of damages in engine parts is the non-compliance of the material of the oil-removing rings, both new and used, with the requirements of the standard for the difference in hardness in a single ring and the total hardness of the surface of the rings. (Conclusions) The detection of the defect is related to the manufacture of rings, the non-compliance of the material of the compression rings of foreign-made engines with the requirements of the domestic standard and the increased consumption of engine oil, which caused emergency damage to diesel engine parts. The transition to the use of domestic internal combustion engines is relevant and necessary in modern conditions. From a practical point of view, it is recommended to check the surface hardness of new compression rings before installation during engine repairs.