Method of control of machining accuracy of low-rigidity elastic-deformable shafts

Abstract

The paper presents an analysis of the possibility of increasing the accuracy and stability of machining of low-rigidity shafts while ensuring high efficiency and economy of their machining. An effective way of improving the accuracy of machining of shafts is increasing their rigidity as a result of oriented change of the elasticdeformable state through the application of a tensile force which, combined with the machining force, forms longitudinal-lateral strains. The paper also presents mathematical models describing the changes of the elastic-deformable state resulting from the application of the tensile force. It presents the results of experimental studies on the deformation of elastic low-rigidity shafts, performed on a special test stand developed on the basis of a lathe. An estimation was made of the effectiveness of the method of control of the elastic-deformable state with the use, as the regulating effects, the tensile force and eccentricity. It was demonstrated that controlling the two parameters: tensile force and eccentricity, one can improve the accuracy of machining, and thus achieve a theoretically assumed level of accuracy.Key words low rigidity shaft, control of machining accuracy, mathematical models of machining, efficiency, mechanics of machine tools

The Use of Neural Networks and Genetic Algorithms to Control Low Rigidity Shafts Machining

“…This type of process control can be exerted by applying a tensile force to the workpiece, which, combined with the cutting force, produces longitudinal-transverse loads. Additionally, one can control the rotation angle of the cross-section of the workpiece at the holding point by applying a tensile force displaced relative to the axis of the lathe centers [ 24 ]. This work-holding solution can be depicted as a movable rotary support ( Figure 1 ).…”

“…Automation of solutions for the machining of high rigidity parts generally does not pose any major difficulties. The real challenge is the automation of machining of parts with atypical dimensional proportions, such as low-rigidity shafts [ 7 ]. When designing machine parts and the devices that are composed of those parts, it is necessary to take into account reliability, both in relation to the production process and the operation and maintenance.…”

Improving the machining accuracy of low-rigid details on the computer numerically controlled lathe machine

“…To increase the accuracy of processing low rigid shafts, several methods are usually used: 1 Using special devices: lunettes, devices that create tensile deformations, etc. [3,4,5]; 2 Changing the feed along the length of the shaft when processing on the numerically controlled machine (CNC) [6]; 3 Reducing the cutting depth throughout the passage [7]. Any modern production is aimed at increasing productivity at minimal cost, so using the first two methods is not practical, because the first method causes some additional costs for purchasing additional devices and their implementation on the lathe.…”

Maintenance research of a horizontal ribbon mixer

“…Technological progress is the counterpart to the growing demand for novel machines and devices that should be characterised by high reliability, functionality, and an extended time of operation in extreme conditions [9], as well as the achievement of the assumed accuracy of machining [16]. Exploitation of structural elements of machines and technical devices usually significantly differs from the parameters in the above in standards [9] or technical data sheets machines.…”