LIMRUC. ASSESSING THE QUALITY OF REPAIR OF AUTOMOTIVE ENGINES

Abstract

To improve the quality of technological processes during the restoration of parts of automotive engines, we carried out micrometrage of the geometric parameters of the working surfaces of the base part of the diesel engines, the block crankcase of the SMD-60 engine on the assembly line of the Remselmash repair plant. (Research purpose) The research purpose is increasing the shape accuracy of the working surfaces of the block crankcase after boring the beds. (Materials and methods) The goal is achieved by increasing the rigidity of the blocks by installing cylinder liners and tightening the bed covers before boring. The following parameters were monitored: upper and lower seats for the cylinder liner, the inner diameter of the cylinder liners before and after pressing into the crankcase, sockets for the inserts of the crankshaft main bearings, holes for the camshaft support necks and for pushers. The state of repair production is assessed by a comprehensive indicator of the organizational and technical level, taking into account the availability and use of regulatory and technical documentation for repairs, advanced repair and technological equipment and tools; the level of technical control, scientific organization of labor and production culture. The complex indicator of the organizational and technical level is 0.67, which is lower than the base value of 0.85. (Results and discussion) The quality of the repaired products is assessed using the Kd defect index based on the micrometreage of the main parts after the restoration and quality control of the assembly of the SMD-60 engines. The defect rate is 597 points, which is significantly higher than the standard value, which should be less than or equal to 280 points for repaired SMD-60 engines with a resource of 80 percent of the new ones. (Conclusions) In order to increase the complex indicator of the organizational and technical level of repair production and reduce the level of defects of repaired engines, it is necessary to organize systematic quality control of the repair of SMD-60 engines, input control of new and restored parts and assemblies and provide workplaces with measuring tools.