Development And Application Of Virtual Manufacturing System For Diesel Engine Boreholes For Process Precision Control

Diesel engine holes machining is very important in the production and manufacture of diesel engine, the machining quality of the holes has a direct impact on the performance of the diesel engine, how to ensure the machining accuracy of the typical holes of diesel engine is one key technology in the process of manufacturing of diesel engine, such as high accuracy and high coaxial holes of cylinder head and composite bolt deep hole of the body etc. At present, the process planning for the machining of the holes of diesel engine is mainly based on manual and its own machining experience to make in our country, this kind of traditional holes machining current situation causes its machining accuracy difficult to guarantee. This paper is aimed at taking the typical holes of diesel engine as the research object, on the basic of the process analysis for accuracy control, effective control of the machining accuracy of the holes of diesel engine was achieved based on three kinds of research methods of NC machining simulation, statistical process control and finite element simulation, the virtual manufacturing system of the holes of diesel engine was developed in the end, so as to optimize the processing technology of the holes of diesel engine, and improve the machining accuracy of the holes. The main research contents of this paper are as follows:(1) In the light of the current situation of low accuracy and large hole axis offset of the holes of diesel engine, the system structure was determined according to the system requirements, then the business process of the system was analyzed, and four key technologies were put forward in this paper, which laid the foundation for the following theoretical research.(2) On the basis of the analysis of the processing technology of the accuracy control, NC machining simulation was carried out for the key working procedure of diesel engine holes based on VERICUT, and the simulation results were analyzed. The results showed that there was no phenomenon of over-cut and undercut during the machining process of key working procedure of the cylinder head, and the critical dimension had reached the accuracy of the holes. So, the geometric accuracy of the holes were verified, and the accuracy of the NC machining process was guaranteed.(3) Under the premise of the NC machining process without error, the size parameters of the key holes of diesel engine after NC machining were collected, the sample data were statistically analyzed and the control chart was drawn based on SPC, to determine the stability of the machining quality of the holes. When the abnormal situation occurred, the reason of the abnormal production was analyzed and the processing technology was improved, so as to achieve the effective control of the machining accuracy of the holes.(4) In the light of the current situation of poor guide accuracy and large axis offset in deep hole machining, the migration mechanism and control technology of the hole axis in the process of deep hole gun drill processing were studied in the method of numerical analysis, which is based on the position of the guide block, the weight of the cutter arbor and the cutting depth. The results showed that the position of the guide block had a significant influence on the deep hole axis deviation, and the optimal angle combination was 70 degree and 180 degree. The influence of the weight of the cutter arbor on the deep hole axis deviation was small and could be neglected. The deep hole axis deviation would be significantly increased with the increase of cutting depth.(5) Through the research of the above theory and key technology, virtual manufacturing system for the holes of diesel engine was developed and example application was carried out, thus the feasibility and effectiveness of the proposed methods and technique were verified in this paper.