INFLUENCE OF THE CUTTING FORCES ON THE STRUCTURE OF A MACHINE TOOL CN-EMCO PC MILL 155

摘要

Accuracy can be defined as the degree of agreement or conformity of a finished piece with the dimensional and geometric accuracy required. The error on the other hand, can be understood as a deviation of the edge of the tool of cutting of the theoretical position required to produce a part with the specified tolerance. The size of the error in a machine gives a measure of accuracy; it is the maximum error of translation between two points in the workload of the machine. Of course, this depends on the resolution of the system. Errors can be classified into two categories, namely the quasi-static and dynamic errors: 1. Quasi-static errors are those between the tools and the work piece which are slowly variable over time and related to the structure of the machine itself. These sources include cinematic geometric errors, which are due to own weight of the components of the machine and the thermal stresses in the structure of the machine tool. 2. Dynamic errors, on the other hand are caused by sources such as the movement of the spindle, the vibrations of the machine structure, errors due to the control of the machine etc. they are more dependent on the particular operating conditions of the machine. Quasi-static errors account for about 70% of the total error of the machine tool which makes the compensation of these errors a very important axis of research. Once the individual errors of components have been identified, the next step of the problem is to use the concept of error budget and to determine the optimum values of these errors to minimize a cost criterion [1].