Design of Motion Accuracy Measurement Device for NC Machine Tools with Three Displacement Sensors

2011 ◽  
Vol 5 (6) ◽  
pp. 847-854 ◽  
Author(s):  
Yukitoshi Ihara ◽  
◽  
Yuki Hiramatsu
Keyword(s):  
Measurement Device ◽  
Coordinate Measurement ◽  
Accuracy Measurement ◽  
Test Standards ◽  
Machining Center ◽  
Displacement Sensors ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Measurement Devices ◽  
Five Axis

To measure motion accuracy, including that of the rotary axis of five-axis machining center that have been widely introduced into production sites recently, a device with three displacement sensors combined to measure the center position of the master ball was invented and will be added to the International Standard. Such measurement devices are not difficult to produce in principle, but the commercially available products are expensive. This study discusses a threedimensional (3D) coordinate measurement device with multiple displacement sensors, discussing it in terms of the test standards of the machines to which the device has been applied and in relation to devices which have been studied, developed, and released. Our measurement device is then designed and produced, and its measurement accuracy is confirmed.

scholarly journals Development of Motion Accuracy Measurement Method of Five Axis NC Machine Tools with ISO230-4

2006 ◽  
Vol 72 (7) ◽  
pp. 873-877
Author(s):  
Masaki USHIO ◽  
Norifumi KURMAE ◽  
Masahide KOUYA ◽  
Hiroyuki NARAHARA ◽  
Hiroyuki KORESAWA ◽  
...  
Keyword(s):  
Machine Tools ◽  
Measurement Method ◽  
Accuracy Measurement ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

Research on Modeling Flow of Volumetric Error for Five-Axis NC Machine Tools

2009 ◽  
Vol 626-627 ◽  
pp. 423-428
Author(s):  
Wei Sun ◽  
Hui Ma ◽  
Chao Feng Li ◽  
Bang Chun Wen
Keyword(s):  
Error Modeling ◽  
Characteristic Matrix ◽  
Volumetric Error ◽  
Machining Center ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Key Steps ◽  
Multi Body ◽  
Five Axis ◽  
Modeling Flow

Based on the achievements of early works, a volumetric error modeling flow which is based on multi-body system theory is put forward. The flow includes 4 key steps mainly: describing structure, setting up coordinate system, creating characteristic matrix and generating volumetric error model are respectively. The operating method of every step is discussed in detail and the solving formula is given. At last, taking the VMC650 machining center of milling and boring which is developed by a machine tool factory as example, the validity of modeling flow is verified. This study can be used as a reference for opening automatic modeling system.

Enhancement of Motion Accuracy for Cone-Frustum Cutting Motion by Modified NC Program

2018 ◽  
Author(s):  
Kiichi Morishita ◽  
Ryuta Sato ◽  
Keiichi Shirase ◽  
Isamu Nishida
Keyword(s):  
Machine Tools ◽  
Opposite Sign ◽  
Accuracy Evaluation ◽  
Error Vector ◽  
Direction Error ◽  
Dynamic Motion ◽  
Machining Center ◽  
Nc Program ◽  
Nc Machine ◽  
Nc Machine Tools

Motion accuracy of NC machine tools is directory copied onto the machined shape. However, it is known that the motion accuracy is deteriorated by several error courses; geometric and dynamic motion errors of feed axes. In this study, in order to enhance the motion accuracy of NC machine tools, a method that modifies the NC program based on the normal direction error at each command point on the designed path is developed. In the method, the error vector between the commanded and estimated machined shape is obtained. The NC program for the motion is modified by adding the obtained error vector with the opposite sign. In order to confirm the effectiveness of the proposed method, 5-axis motion tests for cone-frustum cutting which is widely applied to the accuracy evaluation of 5-axis machining centers are carried out. At the first, it is confirmed that the proposed method can compensate the dynamic synchronous errors based on the feedback positions and angles of the axes. In addition, it is also confirmed that the proposed method can compensate both of dynamic and geometric errors based on the tool center point trajectory measured by a ball-bar system. As the results, it is clarified that the proposed method can effectively enhance the motion accuracy of the 5-axis machining center.

Study on Spindle Thermal Field Distribution and Thermal Errors of Horizontal Machine Tool

2011 ◽  
Vol 697-698 ◽  
pp. 273-276 ◽  
Author(s):  
X.B. Ma ◽  
Jian Qiu ◽  
Qi Wei Liu ◽  
J.F. Lin
Keyword(s):  
Temperature Distribution ◽  
Field Distribution ◽  
Machine Tools ◽  
Thermal Field ◽  
Infrared Imaging ◽  
Positioning Error ◽  
Thermal Errors ◽  
Machining Center ◽  
Nc Machine ◽  
Nc Machine Tools

Research on thermal field and thermal errors of NC machine tools were carried on using infrared imaging and laser distance measurement technologies. It mainly focused on the analysis of thermal field distribution of a three-axis horizontal machining center and the relationships between thermal behaviors and their temperatures. It was found experimentally that spindle thermal errors is one of the main errors sources of NC machine tools, and spindle thermal errors has been observed to be closely linked to the temperature distribution of machine tools. There was a significant increase in the axis positioning error related to the spindle temperature increasing. The elongations on Z direction are much larger than the extensions of X and Y directions. Finally, a method by adjusting spindle temperature to control spindle thermal errors was taken.

A novel approach to calculating the dynamic error reflected on an S-shaped test piece

2020 ◽  
pp. 095440622096215
Author(s):  
Weiwei He ◽  
Liping Wang ◽  
Liwen Guan
Keyword(s):  
Test Piece ◽  
Machine Tools ◽  
Dynamic Error ◽  
Dynamic Performance ◽  
Error Distribution ◽  
Feed System ◽  
Test Pieces ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

This paper proposes a novel approach to calculating the dynamic error distribution reflected on an S-shaped test piece. First, a numerical model of an S-shaped test piece is established, and the distribution characteristics for the twist angle and curvature are analysed. Second, a delay continuous method (DCM), which can transform the discrete input into a delayed step input, is presented to express the single-axis dynamic error affected by the input quantitatively in the form of a mathematical expression. Based on the sinusoidal input, the feasibility of the DCM is verified by comparing the experimental results of a Simulink simulation model and a mathematical expression derived by the DCM. Third, according to a new three-point tangential (NTPT) positioning algorithm and the DCM, this article makes the first attempt to investigate the quantitative calculation method of the influence of the dynamic performance of a servo feed system for five-axis numerical control (NC) machine tools on the dynamic error distribution for S-shaped test pieces after processing. Parameter p, representing the dynamic characteristic of the servo feed system, is varied to compare the difference of the dynamic error distribution law on S-shaped test pieces. The calculation results show that the parameter p can be adjusted to reduce the dynamic error of the final machined test pieces. It is important to improve the dynamic performance of servo feed systems for five-axis NC machine tools and enhance the machining quality of test pieces. In addition, compared with the calculation results of the dynamic error distribution for an NAS979 test piece, the S-shaped test piece can reflect the dynamic performance of the servo feed system for five-axis NC machine tools more accurately and effectively. Finally, the effectiveness of the proposed calculation method is verified through processing experiments on a five-axis NC machine tool.

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