Papers by Keyword: Worktable

Abstract: In this study, a small 6-DOF (degree of freedom) parallel mechanism worktable for machine tool was developed. There are many factors that affect the positioning precision and the accuracy of the machine tool. The uncertainty in position is mainly due to the structural rigidity, the geometric error of the parts and the assembly errors. It is very difficult to estimate the assembly errors and the link parameter of each part. Moreover, it is necessary to make clear the relation of cross talk between each axis for parallel mechanism. In this research, a method to compensate the movement error of worktable based on the measurement result was proposed and discussed. First, in order to measure the positioning accuracy of the worktable a measuring method by using 3-dimensional coordinate measuring machine (CMM) was proposed. After the evaluation, the positioning accuracy of the parallel mechanism worktable, the error of each configuration parameter can be obtained. By the correction of the inverse kinematic program, the improvement of the positioning accuracy of the worktable was confirmed. After calibrating several times, the positioning error became stable within a constant range. It is confirmed that this method to obtain the parameter error is effective, and it is possible to improve the positioning accuracy.

Abstract: In this paper, high-speed vertical machining center of the four schemes(namely general reinforcement worktable, strength general reinforcement worktable, diagonal reinforcement worktable and strength diagonal reinforcement worktable) has been entity modeling in Soldworks. After modeling, do finite element analysis and stiffness analysis to four schemes, the conclusion shows strength reinforcement worktable is the best plan. Then, do modal analysis in order to improve the inherent frequency, get the modal of the system frequency and vibration mode. Finally, according to the results of analysis of static dynamics, in order to improve the natural frequencies of strength general reinforcement system, the worktable has been topological optimization. Because of the result of the topological optimization is not obvious, so choose workbench is verified by reasonable structure.

Abstract: In this study, a small, 6-DOF (degree of freedom) parallel mechanism worktable for machine tool was developed. There are a lot of factors that affect the positioning error and the accuracy of the machine tools. The uncertainty in position is mainly due to the rigidity of the structure, the geometric error of parts and assembly errors. It is very difficult to estimate the assembly errors and the link parameter of each part. In this paper, the uncertainty factor in positioning of the worktable was investigated and compensated based on measurement of movement error by using coordinate measuring machine (CMM).

Abstract: This paper presents a manual moving and lifting worktable. This worktable consists of roof, base,cross frame, wheels, lifting device, wire driving two-way ratchet and parallelogram steering structure. It can do some action such as moving, turning and lifting through the manual operation for the application of warehouse, logistics, and indoor maintenance. The paper analyses the principle and structure of the worktable, especially on the design and work principle of two-way ratchet. The design is satisfied by built a real model.

Abstract: The main work is calculating and analyzing the worktable’s static stiffness in different positions, and drawing 3D static stiffness spectrum of the worktable in Z direction according to the analyzing results. DVG850 High-speed machining centre is taken as the research object, to establish the solid modal in ANSYS Workbench and analyze the worktable’s static stiffness in different positions. and the paper uses its worktable as the researching object. According to the results the spectrum of the static stiffness of the worktable is drawing in Matlab. The spectrum shows that the more the position is near the edge, the larger the static stiffness is, and it changes faster, however the middle is smaller. This spectrum has certain directive significance for the optimal design and improvement of product quality of design.

Abstract: Parallel mechanism has many advantages, such as high stiffness, high accuracy, high degree of freedom (DOF), etc. These fine features are suitable for work table of machine tools for production of recent complicated designs. In this study, six axes linear-actuated parallel mechanism was chosen as the basic design for work table. First, geometrical parameters of the table were designed to satisfy the required movable range with minimum cutting load. Then, the work table was actually constructed and its performance was evaluated. From positioning accuracy measurement, it was found that the table is suitable to be used for machining of complicated products. On the other hand, from actual cutting tests of primitive shapes using chemical wood and measurement of the machined shapes, potential of the table for real cutting application was confirmed.

Abstract: In order to improve machining quality and productivity of complex curved surfaces in high-speed wire electrical discharge machining (HS-WEDM), an additional numerical control (NC) worktable (rotation-swing-swing worktable) and its NC system were designed. The movement model of the four-axle linkage system was established and simulation was developed using the programming language Visual C++ and standard connection software OpenGL.