Evaluation of the Dynamic Performance for Five-Axis CNC Machine Tools Based on RTCP

Author(s):  
Zhong Jiang ◽  
Wei Wang ◽  
Qingzhao Li ◽  
Zhipeng Zhou ◽  
Jiexiong Ding ◽  
...  

RTCP (rotation tool center point), which is one of the necessary functions for high-grade CNC machine tools, can effectively decrease nonlinear errors caused by the motion of the rotation axis and improve the accuracy of the machinery. Based on the characteristic that the cutting tool tip point is relative to the manufacturing workpiece, the RTCP trajectory is proposed to conveniently measure the displacement of the tool tip point. The scheme is utilized to study the dynamic performance of machine tools, and a simulation that shows the relationship between the tool tip error trajectory and the factors influencing the dynamic performance of the machine tool is presented based on the servo system model. Then, the experiment is carried out, and the tool tip point error variation is found to be consistent with the simulation result. This study provides theoretical support for dynamic performance detection of five-axis CNC machine tools.

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Cong Geng ◽  
Yuhou Wu ◽  
Jian Qiu

Since a nonlinear relationship exists between the position coordinates of the rotation axes and components of the tool orientation, the tool will deviate from the required plane, resulting in nonlinear errors and deterioration of machining accuracy. Few attempts have been made to obtain a general formula and common rules for nonlinear error because of the existence of various kinematic structures of machine tools with orthogonal configuration. This paper analyzes the relationship between the deviation of cutter location points and motion of tool orientations. Five-axis CNC machine tools are divided into two groups according to the configuration of the two rotational joints and the home position. Motions of the tool are regarded as a combination of translation and rotation. A model for error calculation is then built. The maximum deviation of the tool with respect to the reference plane generated by the initial and the final orientation is used to quantify the magnitude of the errors. General formulas are derived and common change rules are analyzed. Finally, machining experiment is conducted to validate the theoretical analysis. The research has important implications on the selection of a particular kinematic configuration that may achieve higher accuracy for a specific machining task.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2913
Author(s):  
Rafał Gołębski ◽  
Piotr Boral

Classic methods of machining cylindrical gears, such as hobbing or circumferential chiseling, require the use of expensive special machine tools and dedicated tools, which makes production unprofitable, especially in small and medium series. Today, special attention is paid to the technology of making gears using universal CNC (computer numerical control) machine tools with standard cheap tools. On the basis of the presented mathematical model, a software was developed to generate a code that controls a machine tool for machining cylindrical gears with straight and modified tooth line using the multipass method. Made of steel 16MnCr5, gear wheels with a straight tooth line and with a longitudinally modified convex-convex tooth line were machined on a five-axis CNC milling machine DMG MORI CMX50U, using solid carbide milling cutters (cylindrical and ball end) for processing. The manufactured gears were inspected on a ZEISS coordinate measuring machine, using the software Gear Pro Involute. The conformity of the outline, the tooth line, and the gear pitch were assessed. The side surfaces of the teeth after machining according to the planned strategy were also assessed; the tests were carried out using the optical microscope Alicona Infinite Focus G5 and the contact profilographometer Taylor Hobson, Talysurf 120. The presented method is able to provide a very good quality of machined gears in relation to competing methods. The great advantage of this method is the use of a tool that is not geometrically related to the shape of the machined gear profile, which allows the production of cylindrical gears with a tooth and profile line other than the standard.


2014 ◽  
Vol 556-562 ◽  
pp. 1454-1459
Author(s):  
Dong Sheng You

The use of CNC machine tools signal acquisition, two-way transmission of the temperature sensor data, the ladder design and macro program guide and other methods on the implementation of a temperature sensing system of smart lubrication function. It is not only low-end CNC machine tools can compensate for deficiencies in equipment protection features and maintenance-free function, but also enhance the diversity of processing. Ultimately by analyzing the different lubrication mode, the relationship between the lubricating oil pressure and temperature and other factors, to draw the function in the lubrication in a stabilizing effect on oil pressure and control bearings and nut seat temperature. It is simple and practical, has important theoretical significance and great value.


2019 ◽  
Vol 299 ◽  
pp. 04003
Author(s):  
Juraj Kundrík ◽  
Marek Kočiško ◽  
Martin Pollák ◽  
Monika Telišková ◽  
Anna Bašistová ◽  
...  

Modern CNC machine tools include a number of sensors that collect machine status data. These data are used to control the production process and for control of the CNC machine status. No less importantpart of the production process is also a machine tool. The condition of the cutting tool is important for the production quality and its failure can cause serious problems. Monitoring the condition of thecutting tool is complicated due to its dimensions and working conditions. The article describes how the tool wear can be predicted from the measured values of vibration and pressure by using neural networks.


2020 ◽  
Vol 19 (01) ◽  
pp. 65-85
Author(s):  
Chuan-Hsun Hsu ◽  
Chi-Hsiang Wang ◽  
Syh-Shiuh Yeh

Backlash, friction, and servo lag factors often result in protrusion or segment difference phenomenon in the moving speed reversal of a machine tool’s moving table. This phenomenon can be improved by adjusting the backlash control parameters of the machine tool controller, but the control parameters must vary with the feed rate and payload of the moving table. Therefore, this study performed the circular test process for CNC machine tools, and used different feed rate, radius, and payload motion conditions to discuss the effect of backlash control parameters on quadrant protrusions. First, this study used parameter-range reduction combined with the Taguchi method and the binary search algorithm to search for the optimal backlash control parameters in the parameter setting range, so that the machine tool could have preferable quadrant protrusion performance when executing circular tests. Afterward, the correlation of the moving table feed rate, radius, and payload to the quadrant protrusion was analyzed according to the experimental results. The results indicated that the machine tool moving table feed rate had the most apparent effect on quadrant protrusions, and the relationship between the payload and quadrant protrusion was influenced by the moving table feed rate and circular radius simultaneously.


2014 ◽  
Vol 701-702 ◽  
pp. 874-878
Author(s):  
Shao Hsien Chen ◽  
Chin Mou Hsu ◽  
Kuo Lin Chiu ◽  
Chu Peng Chan

Swivel spindle head is a key component used in five-axis machine tool of high performance and is of great importance in application and design. Nowadays, more and more components are manufactured by high performance multi-axis CNC machine tools, such as components of spaceflight, renewable energy and automobile, etc. Therefore, high performance machine tools of multiple axes are more and more urgently demanded, while Swivel spindle head is one of the most important components for a multi-axis machine tool. Hence, Swivel spindle head is one of the key to developers multi-axis machine tool . The study explores the highly responsive direct-driving motor able to drive the spindle head to rotate with multi-driving rotary technology. The dual-driving motor rotates via multi-driving units, generates torsion that magnifies and eliminates its clearance, and then drives the spindle head to rotate. Results of the test show that the completed machine tool can meet the standards of dual axis rotary head with high preformation in, no matter, speed, distance, positional accuracy, repeated accuracy or maximum torque, etc.


2014 ◽  
Vol 945-949 ◽  
pp. 1700-1706
Author(s):  
Rong Bo Shi ◽  
Zhi Ping Guo ◽  
Zhi Yong Song

This paper studies control and motion theory of feed system of the five-axis CNC machine tools, propose the method of establish mathematical model, kinematics model of the feed system, in order to provide a method of theoretical research for accuracy identification of five-axis CNC machine tools.


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