Відновлення поршневих пальців гарячим пластичним деформуванням

Abstract

The aim of the study is to create a theoretical basis that allows to calculate the forces of hot plastic deformation of the piston pin. One of the promising methods of restoring the piston fingers of the connecting rod - piston group of internal combustion engines is the method of hot plastic deformation. The process of restoring the piston fingers by hot plastic deformation can increase their strength and, in particular, fatigue strength. When developing the technological process of restoration of piston fingers using the method of hot plastic deformation by distributing it with a punch in the stamp, there is a problem of determining the effort required for high-quality deformation process. The article offers the theoretical basis for calculating the deformation forces. The result was obtained on the basis of the selected scheme of formation. As a result of the calculations we can conclude: 1. Restoration of the piston finger by hot plastic deformation allows to restore 95% of the fingers which have arrived in repair. 2. Piston fingers restored by hot plastic deformation in their technical parameters are not inferior to the new, achieved - "healing" of microcracks, creating internal compressive stresses, and grinding grain, which strengthens the material of the piston finger, in particular increasing its fatigue strength by 15… 20% . 3. As a result of theoretical studies of the resistance of the metal to plastic deformation were obtained dependences of the specific force on the punch depending on the ratio of the diameters of the workpiece.