A Triple Translation Parallel Machine Tool with Large Workspace and Additional Redundant Arc Sliding

Abstract

The invention discloses a large-working-space three-translation parallel machine tool for additional redundancy arc sliding. The machine tool comprises a frame, an arc module, a first branch chain set, a second branch chain set, a third branch chain set, a movable platform and a worktable; the lower end of the frame is fixed with a foundation through foundation bolts; the first branch chain set, the second branch chain set and the third branch chain set all consist of three sets of extension rods with the same structures; the arc module is fixed at the middle part of a main stand column of the frame; one ends of the first branch chain set and the third branch chain set are respectively connected with an upper bracket and a lower bracket of the frame, and the other ends are both connected with the movable platform; one end of the second branch chain set is connected with the arc module, and the other end is connected with the movable platform; and all the branch chain sets are connected with the frame, the arc module or the movable platform through spherical hinges at two ends to form a space parallel closed-loop structure. The large-working-space three-translation parallel machine tool, provided by the invention, is compact in structure, flexible in movement, capable of preventing singular configurations, high in rigidity, fast in dynamic response and suitable for machining of large workpieces.

Description

technical field [0001] The invention belongs to the field of numerical control manufacturing equipment, in particular to a three-translational parallel machine tool with large working space and redundant circular arc sliding. Background technique [0002] In the field of grand manufacturing, traditional single-column boring and milling machines, large gantry milling machines and other types of machine tools have problems such as poor dynamic performance, low precision, large body and high cost, which make the processing cost of large workpieces high. As a new concept machine tool, parallel machine tool has its unique advantages compared with traditional CNC machine tools, but there are few cases of parallel machine tool with large working space. [0003] Chinese patent CN105818137A discloses a parallel mechanism with three-dimensional translation, including a moving platform, a fixed platform and three sets of branch chains. The mechanism uses three servo motors to synchrono...

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Problems solved by technology

[0003] Chinese patent CN105818137A discloses a parallel mechanism with three-dimensional translation, including a moving platform, a fixed platform and three sets of branch chains. The mechanism uses three servo motors to synchronously drive a set of retractable branch chains. The disadvantage is that the working space of the mechanism is small , not suitable for large-scale work

Chinese patent CN103240729A discloses a space three-translational parallel manipulator, including a fixed frame, a moving platform, and three branch chain groups symmetrically arranged between the fixed frame and the moving platform. Each group of branch chains is divided into a near frame rod and a far frame. Rods, forming a spatially axisymmetric multi-link structure, the limitation is that the rigidity is poor and the working space is small

The Pegasus wood processing center launched by German Reichenbacher uses three sets of fixed rods with universal hinges at both ends. The rods are connected with three mobile slides and a moving platform by means of hinges, and the operation is limited to a narrow and long working space. And the rigidity is low, and the processing accuracy cannot meet the requirements for processing large metal workpieces

The University of Stuttgart in Germany, the University of Queensland in Australia, Agde College in Norway, and ABB in Sweden jointly researched a large workspace parallel mechanism called Gantry-Tau. One sliding seat has a set of parallel rods, one sliding seat is equipped with three rods to form two parallelograms, the third sliding seat is equipped with a rod, three horizontal guide rails are fixed on the frame, and the platform is moved by planning the movement of the three sliding seats From the space on the left side to the space on the right side, it has a larger working space than other parallel mechanisms, but there are two problems in this mechanism: one, the length of the guide rail must be increased in order to obtain a larger working space, and the mechanism Second, the trajectory planning of the moving platform switching in the left and right space is extremely complicated, and the path that can pass is limited

Zhang Chuanxu. Research on the overall technology of C-shaped gantry parallel machine tool [D]. Nanjing: Nanjing University of Science and Technology, 2013, Shen Xiaojian. Design and optimization of the frame structure of parallel C-shaped gantry milling machine [D]. Nanjing: Nanjing University of Science and Technology, 2015, Guo Jinlong .Study on stiffness and dynamic characteristics of C-shaped gantry parallel milling machine[D].Nanjing: Nanjing University of Science and Technology, 2015 The C-shaped gantry parallel machine tool disclosed in 2015 is an asymmetric three-translational parallel mechanism with redundant linear sliding to form a large Spatial parallel machine tool, although the machining range of this machine tool is larger than that of conventional parallel machine tools, but because the redundant sliders are at both ends of the position, they are far away from the core area of ​​the workbench, making the work space very irregular, resulting in the gap of the work space. Wasteful, performance optimization limited

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