Space double-connecting-rod type ball bar based on ball hinge

Abstract

The invention discloses a space double-connecting-rod type ball bar based on a ball hinge. When an existing ball bar conducts measurement, the bar length change range is quite small and can not cover all areas in a machine tool working stroke. A first precise small ball is fixed to the outer end of a first connecting rod and fixed to a first precise magnetic bowl base in a three-point mechanical positioning mode; a second precise small ball is fixed to the outer end of a second connecting rod and fixed to a second precise magnetic bowl base in a three-point mechanical positioning mode; a ball head and a supporting ball socket of the precise ball hinge are fixed to the inner end of the second connecting rod and the inner end of the first connecting rod respectively; a first sphere-crown-shaped capacitor electrode is arranged at the bottom of the ball head of the precise ball hinge, and a second sphere-crown-shaped capacitor electrode is arranged at the bottom of the supporting ball socket. The three-dimensional movement of the ball bar is achieved through the ball hinge, the included angle between the axes of the two connecting rods is detected through a spherical capacitance sensor, the circular trajectory formed when a main shaft does the space arc movement is calculated according to the angle value and the length of the two connecting rods, and the dynamic precision of a numerical control machine tool is evaluated.

Description

technical field [0001] The invention belongs to the field of error detection of numerical control machine tools, and in particular relates to a space two-link ballbar based on a ball hinge. Background technique [0002] The machine tool is the main machine in the machinery manufacturing industry, and its precision directly affects the level of the manufacturing industry. With the popularization and application of numerical control equipment, the precision improvement methods and technologies of various numerical control machine tools have also become a hot spot for scientific research workers. [0003] At present, the error detection methods of CNC machine tools mainly include direct measurement method, indirect measurement method and comprehensive error measurement method. The measurement method based on the ballbar is a typical comprehensive error measurement method, which has the advantages of fast detection, simple operation, and convenient portability. It is often used...

AI Technical Summary

Problems solved by technology

In addition, the radius of the circular trajectory of the existing ballbar measurement space is basically unchanged (the amount of change is determined by the expansion and contraction amount of about 1mm determined by the length of the rod), which cannot cover (or traverse) all the spatial areas within the working stroke range of the machine tool

Japanese scholars invented the two-link ballbar, in which the two connecting rods are connected by a common rotary joint and the angle between the two rods is measured by a rotary encoder, which effectively increases the measurement range of the ballbar. However, due to Due to structural limitations, the instrument can only move in one plane. If it is necessary to test the three planes of XY, YZ, and ZX on the machine tool, it is necessary to install and test the ballbar multiple times, so the measurement efficiency is low and it is difficult to guarantee High measurement accuracy

Images