Research On Optimization Of Machining Process Parameters And Simulation Method Of Virtual Machining For Large Marine Engine Cylinder Block

The marine engine cylinder block is the core component of a ship,and its processing quality directly determines the ship’s performance and operating performance.Due to the difficulty of processing the engine block of the ship,the first trial cutting is required before the actual mass production is carried out to check the rationality of the NC program and process planning,and the unreasonable selection of the processing technology parameters will cause the processing efficiency and it is difficult to improve the quality of processing.Therefore,it is necessary to deeply study the numerical simulation of NC machining and machining process parameter optimization methods of ship engine cylinder block with virtual simulation.Aiming at the NC process optimization technology of marine engine block,the large-scale gantry five-sided composite machining center is used to simulate the machining of marine engine block.This paper mainly explores the simulation construction method and processing parameter optimization method of Longmen five-sided machining center from the theoretical and technical means such as process planning,tool path trajectory generation,post-processing,optimization of machining parameters,virtual simulation and hybrid programming.And through the rapid development of computer technology through hybrid programming method,the virtual engine environment to optimize the parameters of the engine block and simulation processing.The main research contents are as follows:(1)By analyzing the processing technology of the marine engine block,the processing technology route of the engine block was formulated.By studying the method of generating the tool path trajectory,the calculation method of the step length and line spacing of the tool and the control method of the tool vector were determined.The post-processing algorithm of the gantry machining center was researched,and the post-processor was developed to obtain the NC code recognizable by the CNC machine tool,which lays the foundation for the subsequent virtual simulation processing of the marine engine block.(2)By analyzing the influencing factors of the machining quality of the marine engine block,the milling speed,the feed per tooth,the cutting width,and the cutting depth were taken as optimization variables,and a multi-objective optimization function for the machining parameters of the marine engine block was established.By analyzing the constraints that were satisfied when manufacturing the engine block,an improved geneticalgorithm based on elite saving and large mutation operations was proposed,and a simulated annealing penalty function was used to handle the nonlinear constraint conditions of the ship engine block during processing.Finally,simulation calculations were performed in conjunction with the genetic algorithm,genetic algorithm parameters were adjusted,and the stability of the optimized algorithm was verified.(3)The construction principle and method of the virtual machine tool were studied,and the three-dimensional model and kinematic model of the virtual machine tool were established by analyzing the structure of the gantry machining machine tool used in the actual processing of the marine engine block.The construction method of the side milling head movement of the gantry machining center was proposed,which can realize the side milling head movement at various angles,and the corresponding virtual machining environment was established.By adding the interface of UG and VERICUT,the modeling and simulation were seamlessly connected,and the simulation processing of the marine engine block was completed more conveniently and quickly,which further verifies the correctness of the virtual machine tool and the rationality of the block processing technology.(4)By analyzing the difference between the data stored in C# and Matlab,the data interface between C# and Matlab was studied,and the virtual machining simulation software based on the marine engine block was developed.Combined with the virtual processing software,the parameters optimization and simulation processing of the marine engine block were realized in a virtual environment.Through the trial cutting experiments of the marine engine block,the feasibility of the software was verified by comparing the optimization results.