Studies on the Algorithm for Five-Axis NC Machining with Triangular Facet Model

2013 ◽  
Vol 385-386 ◽  
pp. 726-730
Author(s):  
Ren Xian Geng ◽  
Hou Jun Qi ◽  
Xin Pan ◽  
Zhi Gang Liu

Using five-axis equipment for NC machining of free-form surface is an effective way to improve machining quality and machining efficiency, the surface shape and the five coordinate of the complexity of the machine tool movement led to its tool path planning technology is difficult. The paper aimed at the five coordinate NC machining of free-form surface and puts forward a five-axis NC machining method based on triangular facet model. The research based on triangular facet model, using constant scallop height method to calculate the step distance and improve the cutting efficiency to a great extent. In the process, tool path is generated, combining with the method of configuration space interference free.

2012 ◽  
Vol 443-444 ◽  
pp. 202-208 ◽  
Author(s):  
Shu Kun Cao ◽  
Li Song ◽  
Ke Dong ◽  
Kai Feng Song ◽  
Zhi Ming Sui

In view of all sorts of questions existing in CNC machining, such as machining vibration, so proposed a new method of free-form surface NC machining path optimization based on constant scallop height. This method first discrete surface boundary into the knife touch point based on the maximum tolerance, then in accordance with the maximum allowable scallop height generates circular trajectory with the same scallop, and finally connects adjacent curve path using the diagonal to achieve a continuous cutting scallop height tool path. This method can reduce the number of tools cut in and out parts, reduce the processing vibration and tool wear, and the surface processed has the same precision. This method has simple calculation, suitable for free-form surface of CNC highspeed and precision machining.


Author(s):  
Tomonobu Suzuki ◽  
Koichi Morishige

Abstract This study aimed to improve the efficiency of free-form surface machining by using a five-axis controlled machine tool and a barrel tool. The barrel tool has cutting edges, with curvature smaller than the radius, increasing the pick feed width compared with a conventional ball end mill of the same tool radius. As a result, the machining efficiency can be improved; however, the cost of the barrel tool is high and difficult to reground. In this study, a method to obtain the cutting points that make the cusp height below the target value is proposed. Moreover, a method to improve the tool life by continuously and uniformly changing the contact point on the cutting edge is proposed. The usefulness of the developed method is confirmed through machining simulations.


Author(s):  
Yuan-Shin Lee ◽  
Tien-Chien Chang

Abstract In this paper, a methodology of applying convex hull property in solving the tool interference problem is presented for 5-axis NC machining of free-form surfaces. Instead of exhausted point-by-point checking for possible tool interference, a quick checking can be done by using the convex hull constructed from the control polygon of free-form surface modeling. Global tool interference in 5-axis NC machining is detected using the convex hull of the free-form surface. A correction method for removing tool interference has also been developed to generate correct tool path for 5-axis NC machining. The inter-surface tool interference can be avoided by using the developed technique.


2011 ◽  
Vol 215 ◽  
pp. 176-181
Author(s):  
Li Min ◽  
Ke Hua Zhang

A new tool path generation method based on cutter shaft tilt method was proposed for free-form surface machining by using Ball-end Cutter. Firstly, it introduces the processing quality problems caused by traditional ball-end mill processing. Then cutter shaft tilt was proposed to avoid the above questions. Analyzing the different machining efficiency at the different angle, and then cutter shaft tilt compensation method which based on above method could avoid that problem was proposed. After the paths calculation to a real surface and simulation, the result shows that, comparing to traditional machining method, the new method reduced efficiently phenomenon of extruding and scratching surface. It meets five-axis processing accuracy requirements.


2010 ◽  
Vol 29-32 ◽  
pp. 430-435
Author(s):  
Li Qiang Zhang ◽  
Ye Cui Yan

This paper presents process optimization for the five-axis milling based on the mechanics model explained in Part I. The process is optimized by varying the feed as the tool-workpiece engagements. The linear and angular feedrates are optimized by sequential quadratic programming. Sharp feedrate changes may result in undesired feed-marks on the finished surface. The adopted step is to update the the original CL file with optimized and filtered feedrate commands. The five-axis milling process is simulated in a virtual enviroment, and the resulting feedrate outputs are stored at each position along the tool path. The new feedrate profiles are shown to considerably reduce the machining time while avoiding process faults.


2011 ◽  
Vol 467-469 ◽  
pp. 900-905
Author(s):  
Shu Kun Cao ◽  
Li Song ◽  
Kai Feng Song ◽  
Jie Lv ◽  
Xiu Sheng Chen

In view of all sorts of questions existing in CNC machining, such as machining vibration, so proposed a new simultaneous multi-objective optimization algorithm on free-form surface five-axis machining tool path and tool posture based on constant scallop height. In the algorithm, we first complete the surface fitting on the base of feature points obtained. Secondly calculate principal curvatures of the surface, select tools, and at the same time generate tool axis vector in the current cutter-contact point tool axis. Once again get the maximum spacing and surface curvature in accordance with the tool effective cutting radius, discrete into cutter-contact point, and calculate the cutting depth to adjust the machine feed rate. And finally connect adjacent curve path using the diagonal to achieve a continuous cutting scallop height tool path. This algorithm can achieve the goals such as the same precision, improving processing efficiency, reducing the number of tool cutting in and out, reducing cutting vibration and tool wear and so on. That is the algorithm can achieve simultaneous multi-objective optimization of the free-form surface NC machining finally.


2011 ◽  
Vol 55-57 ◽  
pp. 1932-1937
Author(s):  
Li Song ◽  
Shu Kun Cao ◽  
Kai Feng Song ◽  
Chang Zhong Wu ◽  
Wei Wei Song

The paper presented the development of free-form surface axis NC machining tool path optimization module. In the UG environment, have three-dimensional solid modeling to the surface, and then have the secondary development of free-form surfaces five-axis machining path optimization module through the UG/Open API and VC++6.0. This can realize NC processing path automatically generation and optimization after the three-dimensional modeling. Introduction


2011 ◽  
Vol 697-698 ◽  
pp. 244-248
Author(s):  
Ke Hua Zhang ◽  
Li Min ◽  
Dong Hui Wen

A new tool path generation method based on Z-buffer method is proposed for free-form surface machining by using ball-end cutters. Firstly, to avoid ball-end mill cutting the workpiece, we make the cutter shaft which is perpendicular to machining surface tilt angle θ, then determine the examining area and then judge there is or not a interference occurring between ball-end mill and examining area, if there is, then make a adjustment for cutter shaft. The discretized points within the examining area are efficiently read in and stored directly by the computer hardware; no extra searching and iterative methods are needed. Simulation results show that, comparing with the traditional algorithm, the tool-position calculation time is shorter, and the phenomenon of workpiece squeezed and scratched is less in this algorithm. It meets the basic needs of five axis machining accuracy. Finally we make a practical machining experiment for cutter location generated.


2011 ◽  
Vol 55-57 ◽  
pp. 1441-1446
Author(s):  
Shu Kun Cao ◽  
Jia Jia ◽  
Wei Wei Song ◽  
Kai Feng Song ◽  
Jie Lv

For the free-form surface 5-axis computer numerical control processing field, we can obtain the processing route information according to the secondary development of UG , it also based on the free surface 5-axis numerical control machining tool path and synchronization of posture multi-objective optimization algorithms, then develops a software module according to the analysis comparison of features and programming instructions of the Fanuc and Siemens numerical control system, This module can be realized according to the information from the path for the two numerical control system, this module generates the proper or absolute matching G-code, it also can generate the automatic G-code for many different numerical control system .


Author(s):  
Feiyan Han ◽  
Juan Wei ◽  
Bin Feng ◽  
Wu Zhang

The manufacturing technology of an integral impeller is an important indicator for measuring the manufacturing capability of a country. Its manufacturing process involves complex free-form surface machining, a time consuming and error-prone process, and the tool path planning is considered as a critical issue of free-form surface machining but still lacks a systematic solution. In this paper, aiming at the tool path planning of the impeller channel, a quasi-triangular tool path planning method based on parametric domain template trajectory mapping is proposed. The main idea is to map the template trajectory to physical domain by using the mapping model of parametric domain to the physical domain to obtain the actual machining path. Firstly, the trajectory mapping model of parametric domain to physical domain is established using the morphing technique, and the template trajectory mapping method in the parametric domain is given. Secondly, the clean-up boundary of the impeller channel is determined in the parametric domain, and the quasi-triangular template trajectory of the impeller channel is defined. Finally, taking a certain type of impeller as an example, the quasi-triangular tool path of the impeller channel is calculated, and the tool path calculation time of this method is compared with that of the traditional isometric offset method. The result shows that the computational efficiency is improved by 45% with this method, which provides a new method for the rapid acquisition of NC machining tool path for impeller channels. In addition, the simulation and actual machining are carried out, the results show that the shape of actual cutting traces on the surface of the impeller channel is quasi-triangular, showing that this method is effective and feasible.


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