During the latest years the robots with Delta 3DOF parallel structure began to be used more and more in high accuracy applications, due to their advantages: high stiffness, availability for usage at high rates of speed and acceleration [1, . Obviously, for the high accuracy applications the elaboration of new analysis methods of the positioning accuracy is imposed. Further to the deviations of the element dimensions in the structure of the kinematical couplings or wear, perturbing influences may occur on the positioning accuracy. This work approaches the influence of the maximum clearance in the kinematical couplings on the positioning accuracy and its repartition on the work space of the robots with Delta 3DOF parallel structure, by using a method that has numerical solution.
In the field of manufacturing processes it is observed that the trend is to produce more and more fast, efficiently parts with high complexity, which involves using a high number of tools in the machining process. One of the main solutions for high speed and efficient manufacturing is based on the full automation of the entire manufacturing process. The automatic changing of the tools involved in the manufacturing process is carried out by the automatic tool changing mechanism, thus the auxiliary non-productive time consumed with the tool change is highly minimized. In this paper we present a novel automatic tool changer which is both simple and compact, and any milling machining center provided with chain or disc tool magazine can be equipped with. Also by adopting the use of this tool changing mechanism other subassemblies of the tool changing system, such as the tool transfer mechanism and the waiting position, are substituted by this changing mechanism. The auxiliary movements needed to bring the tool from the magazine into the waiting position are overlapped with the machining time, so that the total time for exchanging the tool in the spindle with the tool from the magazine is minimized.
During the latest years, the robots<strong> </strong>that include mechanisms with Delta 3DOF parallel structure attracted the attention of the university research centers due to their unexploited potential. Besides the advantages given by the Delta 3DOF parallel structure, there is a series of disadvantages too. A significant disadvantage is the fact that the workspace is limited. Under these conditions, the studies on determining and improving the workspace got intensified lately. This work is presenting a study on determining the workspace of a parallel structure Delta 3DOF, by using a method that digitizes the angular position parameters of the active kinematical couplings.
Recent trends in the machine tools domain have focused on improving the manufacturing performances by increasing the feed rates and acceleration values. In this context, the stiffness of the constructive elements which form the mechanical part of the kinematic feed chains need to be studied in order to determine the machine tool dynamic behavior. This study plays a very important role in the correct dimensioning of the feed chain structure and in establishing an optimum control law for the closed-loop system. The present paper presents an experimental study which demonstrates the influence of the whole kinematic feed chain stiffness on the positioning precision of the moving table. Experimental tests were carried out on a test bed which uses the indirect position measuring system, in which case all the external disturbances affecting the mechanical part are found in the values of the positioning precision parameters.
One of the main objectives in obtaining high productivity on machining centers is the reduction of auxiliary times consumed with the tool and workpiece change. In the case of workpiece change the auxiliary time is reduced by adopting the use of an automatic pallet changer system and implicitly of pallets, while in the case of tool change this time is reduced using an automatic tool changer system. The optimization of the constructive and functional parameters of palletizing systems, in the purpose of decreasing auxiliary times, implies increased speed and accelerations, inertia reduction, an optimum transmission ratio, component mechanisms coupled movements, increasing the positioning accuracy of the pallet on the machine table. This paper presents the methodology of transmission ratio optimization of an electric driven pallet changer mechanism, the main purpose is to obtain the maximum acceleration. In order to find the maximum acceleration of the electric driven pallet changing mechanism considered, and thus minimizing the total changing time, we use the equilibrium equation of the moments reduced to the motor shaft. Following the proposed methodology we obtain the maximum acceleration of the considered pallet changer mechanism. Also we issue some constructive indications for future designing of electric driven pallet changer mechanisms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.