Investigation On The Remanufacturing Engine Critical Parts’ Dimensions Recovery Technology

During Engine use, some parts of the original geometric shape anddimensions will change due to wear, deformation, breakage, fracture,corrosion, and other damage.thereby undermining the characteristics andworking ability of co-ordination between the parts, so that the parts,assemblies and even the normal working of the machine is affected.This paper carried out the size of the key parts of the engineremanufacturing recovery technology research. First, do some basic work,these are developed automated spraying platform which provides thefoundation for the experiments carried out and process research; study theperformance of the spraying supplies and its spray coatings, and providethe basis for the spraying selection. Based on the above work, respectively,using the cold spray, thermal spray, swelling repair recovery techniques tostudy the process of the crankshaft, engine block waterways, piston pinsand cylinder head conduit hole and critical process. Specific content andconclusions are as follows:1.In order to overcome the high cost of the spraying machine hand, onthe basis of the normal decommissioning lathe, to develop automatedspraying platform. The spray platform meets the plane, shaft, bore engineparts spraying requirements. At the same time, according to thecharacteristics of the plane, shaft, bore parts of the engine, planning thepath of spraying walk. In order to figure out which coatings to selectaccording to the required repair parts,coating performance sprayed by fivekinds of consumables of cold spray and two kinds of thermal consumablesspray has been compared. Physical characteristics of each consumable and coating adhesion strength, hardness, wear resistance and tribologicalproperties of law are obtained.2.High velocity arc spraying process to restore the crankshaft journalsize has been studied.Its main processes include:pretreatment beforespraying,the crankshaft spraying, processing after crankshaft spraying.Forroughening process before spraying the surface preparation ofsandblasting,the main factors of roughening pretreatment processparameters on the surface roughness has been analyzed.And gives theseimpact factor important order, the relationship between the thesandblasting parameters and the substrate surface roughness obtained bylinear regression formula.It has guiding significance for selection of thesand, the formulation process parameters as well as surface roughnessacquisition method.In order to clarify how pretreatment Surface roughnessaffects coating adhesion strength,depth analysis of the roughness values ofthe interval of the three roughness on the bonding strength are carriedout.The conclusion is that the roughness values of the three roughnessinterval satisfys coating adhesion strength requirements.3.Cold spray process to restore the size of the engine block waterwayshas been studied. The process comprises surface roughening, spray coating,processing after spraying.After the recovery of the waterways through thecold spraying,coating performance has been characterized, proved thecoating performance meets the requirements.4.The size recovery process of Piston pin and cylinder head theconduit hole are researched by the elastoplastic deformation and expandedjoint methods.For the piston pin which working surface is the outercylindrical surface and cylinder head conduit hole which working surfaceis the internal cylindrical surface, the elastoplastic deformation method andexpansion copper conduits were used and studied. Derivation from theperspective of elastoplastic mechanical principle of the process is given,and the process validated, process specifications formed. And applied foran invention patent and a utility model patent.