Simulation And Optimization Of Cylinder Block Production Line Of High-power Diesel Engine

Diesel engines are widely used in the fields of marine power,power generation,irrigation,vehicle power and so on,especially in the field of vehicle power.There has been a tendency of "dieselization"of vehicle power around the world.Cylinder block,one of the important portions of the engine,is the basis of installing all parts of the engine.The huge demand for automobiles in the market determines the fact that the cylinder block is generally produced by the production line.However,with the increase of market demand,most rigid production lines in China are faced with the problems of low utilization of equipment and insufficient production capacity.Therefore,optimizing the configuration of production line and improving the utilization as well as the output of equipment in production line is of great significance.This article focuses on the simulation and optimization of diesel engine cylinder block production line,the main researches contents are listed as follows:(1)Virtual machining simulation technology was used to verify the rationality of decentralized process flow of cylinder block in mass production.First,combined with the technical requirements and processes of cylinder block,the structural characteristics of the cylinder block and typical processes in the processing process were analyzed.Additionally,the UG processing module was used to program the typical process,and the NC program of the typical process was obtained.At last with the help of VERICUT,the virtual machine tool of DMU125FD was established.Typical processes were centralized together for virtual machining simulation and compared with the actual situation of the production line.This research showed that in the process of the mass production of diesel engine cylinder block,it is reasonable to adopt the distributed processing procedure and combine it with the high efficiency machine tool in the current production line.(2)Plant Simulation software was used to establish the production line model and optimize the configuration of the production line.Firstly,according to the production process and related data of cylinder block production line,an object-oriented model of the production line was constructed.Secondly,In order to solve the problem of imbalance of the production line,the buffer allocation mode for each station was adjusted.The optimal buffer allocation location was obtained using genetic algorithm.Lastly,the optimal buffer allocation scheme was obtained using the method of simulation configuration:the first and second bottleneck processes were configured with buffers of capacity 19 and 3.respectively,and the off-line machine tools were arranged to regularly clear the buffer backlog.(3)The mathematical model based on queuing theory of the production lines was established,and the optimal configuration result of production line was obtained by this model.At first,the M/M/1/N queuing system was analyzed and its state probability equation was obtained.Furthermore,the serial production line with N machine tools was decomposed into a set of subsystem.The mathematical model of cylinder production line was established.Last,the optimized configuration scheme of buffer was selected by genetic algorithm.The result of the scheme was consistent with that of the simulation model,which indicated that the optimized results and two models were both reliable.In this paper,the rationality of production process and equipment of cylinder block was verified by CNC virtual machining.Then.the object-oriented simulation model and mathematical model based on queuing theory of the cylinder block production line was established.The buffer configuration was optimized separately,and the optimization results obtained by the two methods were basically consistent,indicating that the two models and the optimization results had high reliability,which provided the technical support for the transformation and optimization of the production line.