Papers by Keyword: Machining Centre

Abstract: The increasing of vibration stability for the technological system is always the vital task for different material processing. Vibration stability increasing methods are divided into constructive and technological. It’s necessary to take into consideration different factors such as vibration whence, vibration parameters, immediate changing of processing mode possibility while choosing the method of vibration decreasing for the technological systems. The present article is reviewing the research methods of milling technology elements as one of the basis of technological methods for increasing of vibration stability.

Abstract: In this article we present a methodology of minimizing the number of movements performed by an existent pallet changer mechanism attached to an horizontal machining centre. After analysing the existent pallet changer mechanism along with the machining centre we obtained new optimized constructive alternatives regarding the number of movements performed by the pallet changer. After applying the tree-graph method we had optimized structurally the considered pallet changer mechanism and obtained the constructive configuration which performs the least movements in order to change the pallet. The small number of movements of the resulted pallet changer mechanism helps the design engineer to choose the most simple structure which reflects positively in the production cost. The minimum movements number obtained by making use of this method will lead to a simplification of the driving, command and control system of the pallet changer mechanism.

Abstract: The use of machining centres is predominant in the case of small and medium size batch manufacturing, their advantages being materialised in high productivity. The productivity is owed, mainly, to the small auxiliary times consumed with the tool and material change, times which are served by the automatic tool changer system and the automatic pallet changer. The purpose of this article researches aims to determine the kinematic parameters of an hydraulically driven linear pallet changer in two cases (when the deceleration is carried out through a throttle and when the deceleration is made through a new solution). Thus, an experimental set-up, which matches an hydraulically driven linear pallet changer, was designed and built. The experiments aimed toward using a classic braking method of hydraulic cylinders and a new two-stage braking with counter-pressure limitation.

Abstract: During machining operations on machining centres, there are a large number of internal and external factors that act on the technological system. They generate errors that influence the manufacturing cost, productivity, and machining accuracy. The monitoring and control system developed for machining centres presented in this paper consists of 3D touch probes, a device for registering a contact between the cutting tool and workpiece, devices for measuring the geometric accuracy of the machine tool and for calibrating the touch probe in the spindle, parameterised CNC programmes, computer and software for data processing and database management. The developed system guarantees monitoring of the machining accuracy, low cost, high level of productivity, low number of preparatory work and measurements, increased reliability due to reduced scrap rate by reducing the probability of cutting tool breakage, the possibility of automating the measurements and processing the data, and wide applicability.