Approach Of Process Technology For The Key Parts Of A Type Marine Diesel Engine

Known as ship's heart,marine diesel engine is the main power propulsion device.It's cost may make up 10%-15% of the total ship price in general.Due to the characteristics of low oil consumption,reliable structure and function,long life cycle and so on,low-speed marine diesel engine widely used in large sea-going vessel,tankers,bulk carriers.Recently the customer's demand is increasing in high performance,low oil consumption,low emission.The patent holder must develop new engine for the demand of the ship-owner.The engine manufacture also needs to develop new machining technology for it.This thesis is for a new type engine for the first time.Compared with the same bore engine,the key parts of this engine which was the latest development of MAN's products series have changed greatly in structure,materials,size,etc.Therefore,research of the key parts processing technology is imminent.In this paper,the processing and manufacturing process of the key parts of marine main engine is studied.From the performance of key parts,the analysis of the processing requirements,the key and difficult points are determined.First of all,the performance and processing requirements of the six key parts are summarized.Then the processing technology of the machine frame and connecting rod is discussed in detail.Be directed against the machining difficulties of the large frame box,on the base of structure features and technical requirements of the frame box were analyzed,determined the guide board manufacturing accuracy,and found that it also is the focus of the inspection determine,so the guide board manufacturing is the critical procedures for processing;and then based on the research of the processing drawings,it has been clear about the design basis,locating datum,benchmark,crude benchmark,decided to determine the processing crude benchmark by layout;by selecting the processing methods and equipment to determine the process route,the principle of machining datum transformation,calculation of dimension chain in the manufacturing process of the guide boar,and finally determine the frame processing technological process;On the part of the key working procedure,by considering the method of guide board milling,in order to guarantee the machining precision it should be ensure that the whole milling process of guide is down milling,therefore,it have to be used the left-hand milling and left-hand blade in a specific location,write the CNC program for numerical control machining.Be directed against the machining difficulties of the large connecting rod,the structure feature and technology requirement were analyzed,and then the design basis,machining datum,machining tools,finally the machining process of connecting rod is determined.Be directed against the machining difficulties of the deep hole of the connecting rod,analyzed the form of process hole,special process equipment,the cutting parameter.The cutting has been applied in the manufacturing of new products.The research results of this paper have been verified in the period of the latest engine manufacture,and will be expanded and used.It maybe provide a theoretical and technical support for process development of other kind of engine.