Research on the peak prediction and intelligent computing of reversal error for the tilt feed system installed on the precision machine tools

To effectively predict the peak of reversal error of tilt feed system and reduce reversal error caused by friction and gravity components, a peak prediction method of reversal error for tilt feed system on the precision NC machine tool is proposed. According to the load, tilt angle, motion trajectory, maximum static friction torque and relevant dynamic characteristic information, the peak prediction formula of the reversal error for the tilt feed system is established by mathematical derivation based on the kinematics, dynamics and torque balance during the process of reversal. Thus, the peak of reversal error for the tilt feed system can be obtained. The experimental results show that this method can achieve a good prediction effect, and can predict the peak of reversal error before the machining. It provides a theoretical basis for the reversal error suppression.

Research on Fixture Design of NC Machine Tool Based on UG 3D Modeling

Research on the design of CNC machine tool fixture based on UG 3D modeling; Firstly, the processing procedure of the back cover parts is analyzed, and the overall scheme of the fixture is determined. Then the three dimensional model of each part of the jig is established including the standard part library of jig and the design of non-standard parts of jig. Then carry on the fixture 3D assembly drawing design; Finally, it is converted into fixture technical document including assembly drawing and specific part drawing. The design process is simple and clear, which improves the quality and efficiency of fixture design.

A Geometric Accuracy Error Analysis Method for Turn-Milling Combined NC Machine Tool

Turn-Milling Combined NC machine tool is different from traditional machine tools in structure and process realization. As an important means in the design stage, the analysis method of geometric accuracy error is also different from the traditional method. The actual errors and the error compensation values are a pair of "symmetry" data sets which are connected by the movement of machine tools. The authors try to make them more consistent through this work. The geometric error terms were firstly determined by topological structure analysis, then based on homogeneous coordinate transformation and multibody system theory, the geometric error model was established. With the interval theory, the function rule of sensitivity of geometric error sources to spatial errors was analyzed in detail, and the global maximum interval sensitivity of nine geometric error sources was extracted, providing a theoretical basis for error compensation and precision distribution. The geometric error sensitivity analysis method proposed in this paper can accurately evaluate the influence weights of each error term on the machining accuracy, and identify the important sensitive error terms with great influence on the machining accuracy from many error terms.

Transcriptional Characteristics of Quadrant Glitches on Machined Surface – Influence of Tool Diameter and Feed Rate –

When a three-dimensional shape is machined by NC machine tool, motion errors occur around the motion direction changing points of the translational axis. This has a significant influence on a quality of machined surfaces. Therefore, much research on the influence of motion errors around the motion direction changing points of the feed drive system on a machined surface has been conducted to improve the quality of machined surfaces by NC machine tool. Among the motion errors that occur around the motion direction changing points of the translational axis, quadrant glitches with a stick-slip motion have a particularly large influence on the machined surface, and research on compensation methods continues to be reported. However, the transcriptional characteristics of quadrant glitches of the translational axis for machine tools have not been investigated adequately. In this study, the transcriptional characteristics of quadrant glitches of the translational axis on a machined surface were investigated. In addition, the influences of various factors on the transcriptional characteristics of quadrant glitches on a machined surface were investigated using a proposed equation and actual machining tests.

The Errors Recognition and Compensation for the Numerical Control Machine Tools Based on Laser Testing Technology

To improve the accuracy of numerical control machine tools error, this paper studies the application of laser testing technology in numerical control machine tool, and put forward a laser interferometer automatic aiming system which can conduct space error measurement. The system, in the process of the NC machine tool operating, can measure the machine tool space curve through changing the direction of the laser. The principle of laser interferometer and matlab analysis are adopted, through the experiment of laser interference technology in the numerical control machine tool, the law curve of error in NC machine tools is obtained, getting the method of error of NC machine tools. When conducting laser testing error experiment in NC machine tool, the results show that the laser testing can measure aggregated error and thermal error of NC machine tool better, with small control of environment and high accuracy of measurement.