Study And Application Of The Constant Pressure Control Technology Of Coordinate Polishing Crankshaft With Abrasive Belt

Nowadays, China is known as a shipbuilding country, but it do not say to reach ashipbuilding leader, at the same time marine crankshaft is a tool that directly used forconnecting between diesel engine and propeller and transfers the propulsion, that has amotto the large ship “heart”(diesel engine) of “heart”; And its characteristic includescomplicated shape, poor stiffness, easy to deformation and high quality requirements. Inthe process of the crankshaft crankpin coordinate polished by the abrasive belt, becauseof the special structure of the crankshaft, the gravity of the coordinate mechanism,friction and inertia force changed at any time, that influence the polishing process, andthat may result stress of the crankshaft crankpin uneven, thereby affecting thecylindricity and roundness of the crankshaft crankpin, at the same time polishing timewill affect the surface roughness, so that will cause the surface roughness of thecrankshaft crankpin uneven. In order to realize the constant pressure polishing, need toanalyze the polishing process,Therefore, the subject about “study and application of the constant pressure controltechnology of coordinate polishing crankshaft with abrasive belt” of study, this mainresearch works in this paper are as follows:Firstly, the motion model of coordinate polishing crankshaft crankpin with abrasivebelt was established according to the main properties of the abrasive belt coordinatelypolishing crankshaft crankpin. And under the condition of the crankshaft was polishedin the constant rotating speed, its movement schematic diagram and the curve ofabrasive trajectory were analyzed. Under the condition of the crankshaft crankpin waspolished in the constant pressure, the crankshaft variable speed rotating was analyzed,namely the single abrasive constant moved on the surface of the crankshaft crankpinwhen it polishes the crankshaft crankpin; At the same time, The crankshaft crankpinpolishing force and the coordinate mechanism force were analyzed, in order to makecrankshaft crankpin only clamped force by polishing shoe.Secondly, under the condition of the crankshaft crankpin was polished in theconstant pressure, and its influence on the error processing precision neck connectingrod the processing error influenced machining accuracy of the crankshaft crankpinwhich was analyzed.1) Because of the impact of machine assembly errors, the errorexists between the center height of the coordinate and the rotary center height of the crankshaft;2) the lag error of the crankshaft variable speed rotating;3) the wear error ofthe polishing shoe. According to those errors analyzed, and the corresponding errorcompensation model were introduced.After that the grinding system was designed and analyzed. For mechanical part,there mainly designed polishing shoe; For electrical part, there mainly designedelectrical control principle and selected relevant electric components; For the controlpart, in the process of the crankshaft crankpin polished in the constant pressure, at thefirst, the main technical characteristics of SINUMERIK840D and the numerical controlsystem hardware architecture schematic were introduced; And then to analyze theoverall work flow, and finally to analyze the interpolation theory about the crankshaftvariable speed rotating.Finally, there were the routine experiment and the crankshaft crankpin polishedexperiment in the constant pressure, the two groups of the polishing experimentalresults contrasted and analyzed, after the crankshaft crankpin was polishing in theconstant pressure, its surface roughness of the consistency is the better, and the surfaceprofile meets the requirements.