Research on influence of geometric parameters of engine body parts during repair process

Exterior parts of complex constructions are widely used in internal combustion engines for various purposes, such as pumps, compressors, etc. Solving the problem of high-quality repair of parts of complex configuration, effective control of their technical condition during their reuse requires solving a number of engineering, technological and metrological tasks. The durability of modern cylinder blocks is ensured by the use of high-quality materials, improved element construction, equal strength of parts with optimal manufacturability, maintainability, quality of assembly and service. To conduct the research, technological schemes for monitoring and measuring deviations in the location of the main geometric parameters of the cylinder block were developed. Engineering documentation and technological support for the manufacture of a control and measuring device for controlling the alignment of the holes of the main bearings were developed. Processing of the measurement results by indicator devices in the workshop conditions shows that the deviation from the alignment or displacement of the middle root supports relative to the extreme ones can reach a value of −0.08 to +0.09 mm, which is significantly beyond the diameter limit. The values of the results show that the maximum deviations occur in the horizontal plane (1800–3600) with a transition to the lower part of the vertical plane. This direction of displacement can be explained by the zone of maximum values of the forces acting during the engine operation. It should be assumed that the values of actual deviations in the range of −0.04 to +0.04 can be accepted for the use of cylinder blocks. The construction of the device with indicator counting devices was developed to ensure control and measurement of the alignment of the holes of the main bearings. Laboratory tests of the device and metrological evaluation of the permissible measurement error were carried out. The results obtained made it possible to increase the productivity of defect detection work and develop recommendations for improving the aftermarket reliability of engines.