Design And Precision Analyze Of Turn-Turn Broaching CNC Machine Tool

In this paper, the purpose and significance of designing turn-turn broaching CNC machine tool is shown firstly. Then, the development of manufacturing and CNC technology and the character of CNC machine tool are introduced.At present, turn-turn broaching CNC machine tool is widely employed to process crankshaft main journal and pin journal at home. In this machine tool, many parts can be processes if workpiece is load and unload one time. Machining precision and work efficiency are improved at the same time. Some fields of turn-turn broaching CNC machine tool, such as the basic configuration, constitutes, project and principle of tools, are introduced. And technics structure of processing crankshaft is analyzed and compared in this paper.Turn-turn broaching CNC machine tool is presented in this paper is technical tools for machining crankshaft. The crankshaft is one of the most important parts in the engine. So not only dimension and weight of engine, but also dependability and life of the engine are affected greatly by its structural parameter and processing technic level. Many means of processing crankshaft can be used, such as turning, milling and broaching. But shape and position precision can not be guaranteed perfectly. If crankshaft is machined in turn-turn broaching CNC machine tool, the request of machining and the request of precision can be guaranteed at one time. In this paper, structure of crankshaft is introduced, the processing technic of processing crankshaft is discussed, and stress of crankshaft is analyzed and calculated.In the paper , starting with turn-turn broaching CNC machine's movement, the mathematics model of the workpiece are established, setting up the basic movement's function and analyzing the result are done.At present, there are lots of means for measuring precision of CNC machine at home, several aspects are expatiated in the paper, for example, precision measures of CNC machine, technology of error compensation, check of position precision and improving the process precision, and analyzing the error of the numerical control machine is done, too.In the paper the comprehensive designed scheme of turn-turn broaching CNC machine tool is presented and machining methods of it is studied. And the routes of processing technic is worked out, program list of machining the crank is studied out, and the feasibility of the design is tested.In the end, the author analyzed economic benefit that the design of the turn-turn broaching CNC machine tool can bring to the enterprises and society, and summarized the excellences in the design, pointed out the deficiencies in it.