Design And Research Of Modular Machine Tool Of Drilling,Broaching And Reaming For Crankcase Of V-Engine

As the major machine in mechanic field, machine tool has developed quickly in100years. In order to fit the need of mass production, modular machine tool emerges as the times require. The main design and research mission of this paper is to design a modular machine tool of drilling, broaching and reaming to meet the requirement of processing V-engine tappet holes, which includes the discourse of research background and significance, ensure the processing technology program and machine configuration form, accomplish the overall design of the machine tool, analyze the process accuracy of machine tool and the force of the cutting tool. This modular machine tool can make the workpiece assembled rapidly while positioned reliably and can make drilling, broaching, reaming three stations rotate automatically. Also, with the adjustment of fixture size and work cycle control, it can process the different number of tappet holes so as to make a certain flexibility of machine tool, ease the labor intensity and improve productivity.In the process of design, firstly, developed some alternative plans according to the process requirement of tappet holes and the structural features of crankcase, comparing the merit and demerit of each program to get the best one, which include: the process, allocation and clamping methods. Secondly, according to the processing technology program to design the whole machine, which include:selected machining allowance and drew the operation drawings; selected the cutters, calculated the cutting data, selected spindles and connecting rod, designed the guide, selected the power units, designed the working cycle and drew the processing schematic drawing; selected the loading height and space required of the machine, then completed the contact size drawing of the machine; calculated the machine productivity card; designed the spindle box and its drive system; designed the machine fixture, including the allocating and supporting system of the clamp, the calculation of clamping force, the designing and checking of clamping components, and completed the assembly drawing of fixture; designed the working cycle of machine. Besides, this paper analyzed the machining accuracy from three aspects:the inversion precision of turret head, the kinematics’accuracy of slide and work table. Finally, in consideration of the insufficient stiffness about elongated cutting tools, we used PRO/E to get the three-dimensional model of twist drill and used ANSYS to analyze its statics problem.In this paper, the design of the whole machine can guide for the further design. For this, we also need researches of integral structure of machine under the work force, researches of vibration affect on the machining accuracy of machine tools, researches of rigidity and reliability of whole clamp, and also researches of control system, cooling and lubrication system. After machine’s manufacturing, assembling and debugging, we can put it into practical at last.