IMPROVEMENT OF TECHNOLOGY AND EQUIPMENT FOR INCREASING THE REPAIR QUALITY OF CYLINDER LINERS OF AUTOMOTIVE ENGINES

Abstract

The article presents the developed technology and equipment for vibration honing of cylinder liners of automotive engines. The device is attached to the spindle head of the machine between the spindle and the hone of the honing machine. The roughness of the treated working surface of the sleeves is reduced and the lubrication conditions of the sleeve–piston ring coupling of the connecting rod-piston group of automotive engines are improved after repair. (Research purpose) The research purpose is to improve the technological process of honing cylinder liners in order to reduce the time for processing the inner surface and improve technological parameters. (Materials and methods). The final honing of the inner surface of the cylinder liners was carried out by the method of flat-topped honing with graphite saturation of the inner surface of the liners. The article presents the design of a honing head with abrasive-filled polyamide threads for flat-topped honing of the inner surface of the cylinder liners of automotive engines. The use of the proposed head makes it possible to reduce mechanical losses and increase the service life of the sleeve-piston of KAMAZ-740 engines during repair. (Results and discussion) In order to increase the wear resistance of the cylinder liners of automotive engines, it was proposed to additionally carry out patching of the inner surface during the repair process. The applied layer has one hundred percent extreme pressure resistance with a counter-coupling part (piston ring). Tests during the running-in and operation of the D-240 engines showed high (1.2-1.4 times) wear resistance of cylinder liners after brassing in comparison with liners restored according to standard technology. (Conclusions) The results of the study indicate the expediency of applying the developed recommendations for improving technology and equipment at repair and technical enterprises of the agro-industrial Stavropol Territory. The calculation of the economic efficiency of improving the technology and equipment for repairing the cylinder liners of automotive engines at the site in the AOOT "Repairman" showed the expediency of increasing their wear resistance and the resource of the connecting rod-piston group.