An Accurate and Efficient Approach to Three-Dimensional Geometric Modeling of Undeformed Chips for the Geometric and the Physical Simulations of Three-Axis Milling of Complex Parts

Author(s):  
Zhiyong Chang ◽  
Zezhong C. Chen

To pursue high-performance computer numerical control (CNC) milling of complex parts, it is crucial to simulate their machining process geometrically and physically with high fidelity beforehand. The geometric simulation is to construct three-dimensional (3D) models of the finished parts and to compute geometric deviation between the models and the part designs, in order to verify the planned tool paths. The physical simulation is to build undeformed chips geometric models and in-process workpiece models and to compute instantaneous cutting forces, in order to optimize the machining parameters. Therefore, it is essential to accurately and efficiently model undeformed chips geometry in machining complex geometric parts. Unfortunately, this work is quite challenging, and no well-established method for this work is available. To address this problem, our work proposes an accurate and effective approach to 3D geometric modeling of undeformed chips geometry in three-axis milling of complex parts. The outstanding feature of this approach is that undeformed chip models and in-process workpiece models can be effectively constructed. This approach lays a theoretical foundation for the geometric and the physical simulations of three-axis milling. It advances the technique of machining simulation and promotes high-performance machining of complex parts.

2014 ◽  
Vol 701-702 ◽  
pp. 223-226
Author(s):  
Shuang Wu

This paper is study on the two-dimensional simulation of the machining process, and three-dimensional simulation. Analog three-axis CNC milling machining entity, it will be processed rough triangular facets discrete and discrete vector geometry and tool scans the body to do intersection algorithm to simulate the tool cutting process by continually updating the blank data to achieve material simulation removal process.


2020 ◽  
Vol 4 (3) ◽  
pp. 66
Author(s):  
Yubin Lee ◽  
Alin Resiga ◽  
Sung Yi ◽  
Chien Wern

The purpose of machining operations is to make specific shapes or surface characteristics for a product. Conditions for machining operations were traditionally selected based on geometry and surface finish requirements. However, nowadays, many researchers are optimizing machining parameters since high-quality products can be produced using more expensive and advanced machines and tools. There are a few methods to optimize the machining process, such as minimizing unit production time or cost or maximizing profit. This research focused on maximizing the profit of computer numerical control (CNC) milling operations by optimizing machining parameters. Cutting speeds and feed are considered as the main process variables to maximize the profit of CNC milling operations as they have the greatest effect on machining operation. In this research, the Nelder–Mead simplex method was used to maximize the profit of CNC milling processes by optimizing machining parameters. The Nelder–Mead simplex method was used to calculate best, worst, and second-worst value based on an initial guess. The possible range of machining parameters was limited by several constraints. The Nelder–Mead simplex method yielded a profit of 3.45 ($/min) when applied to a commonly used case study model.


2012 ◽  
Vol 510 ◽  
pp. 384-389
Author(s):  
Jin Gui Wan ◽  
Fei Zhang ◽  
Bei Hua Li ◽  
Qi Gao

A complex part, which has curved surface overall, is trial-manufactured with CNC machine. The NC machining process and technology of this full-surface part are studied in this paper. First, the 3D model of the part is created in the modeling module of UG system. Then, process analysis and scheme are developed. As the part has an irregular shape and the entire surface is to be NC machined, there are many difficulties during processing. The optimized process plan is determined. In the manufacturing module of UG system, the NC machining parameters are set according to the processing requirements, the tool paths are generated, edited and checked, and the NC code is generated by post processing. Finally, the part is manufactured using a 3-axis CNC milling machine with the NC programs. It has desirable shape and high accuracy. The result shows that the NC process is reasonable and efficient. CAD/CAM integration technology is applied successfully in this example. The methodology and technology introduced in this paper can provide valuable reference for processing similar parts, and it is also useful for correlational study.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257158
Author(s):  
Wei-Ting Chou ◽  
Chuan-Chung Chuang ◽  
Yi-Bing Wang ◽  
Hsien-Chung Chiu

This experimental study aimed to compare the internal fit (marginal fit and internal discrepancy) of metal crowns fabricated by traditional casting and digital methods (computer numerically controlled (CNC) milling and three-dimensional [3D] printing). Thirty standard master abutment models were fabricated using a 3D printing technique with digital software. Metal crowns were fabricated by traditional casting, CNC milling, and 3D printing. The silicon replica method was used to measure the marginal and internal fit. A thin layer of low-viscosity polyvinyl siloxane material was placed inside each crown and on the die (like a seat) until the material was set. Replicas were examined at four reference points under a microscope: the central pit (M1), cusp tip (M2), axial wall (M3), and margin (M4). The measured data were analyzed using a one-way analysis of variance (ANOVA) to verify statistical significance, which was set at p < 0.05. In the traditional casting group, the minimum distance measured was at M3 (90.68 ± 14.4 μm) and the maximum distance measured was at M1 (145.12 ± 22 μm). In the milling group, the minimum distance measured was at M3 (71.85 ± 23.69 μm) and the maximum distance measured was at M1 (108.68 ± 10.52 μm). In the 3D printing group, the minimum distance measured was at M3 (100.59 ± 9.26 μm) and the maximum distance measured was at M1 (122.33 ± 7.66 μm). The mean discrepancy for the traditional casting, CNC milling, and 3D printing groups was 120.20, 92.15, and 111.85 μm, respectively, showing significant differences (P < 0.05). All three methods of metal crown fabrication, that is, traditional casting, CNC milling, and 3D printing, had values within the clinically acceptable range. The marginal and internal fit of the crown was far superior in the CNC milling method.


Author(s):  
Vahid Pourmostaghimi ◽  
Mohammad Zadshakoyan

Determination of optimum cutting parameters is one of the most essential tasks in process planning of metal parts. However, to achieve the optimal machining performance, the cutting parameters have to be regulated in real time. Therefore, utilizing an intelligent-based control system, which can adjust the machining parameters in accordance with optimal criteria, is inevitable. This article presents an intelligent adaptive control with optimization methodology to optimize material removal rate and machining cost subjected to surface quality constraint in finish turning of hardened AISI D2 considering the real condition of the cutting tool. Wavelet packet transform of cutting tool vibration signals is applied to estimate tool wear. Artificial intelligence techniques (artificial neural networks, genetic programming and particle swarm optimization) are used for modeling of surface roughness and tool wear and optimization of machining process during hard turning. Confirmatory experiments indicated that the efficiency of the proposed adaptive control with optimization methodology is 25.6% higher compared to the traditional computer numerical control turning systems.


2014 ◽  
Vol 687-691 ◽  
pp. 113-116
Author(s):  
Ge Zheng ◽  
Chun Wang ◽  
Bo Huang

Inverse design is the process of using a certain means of measurement to measure entity or model, and according to the measurements, refactoring physical CAD model through Three-dimensional geometric modeling methods. Basing on the little model, use reverse engineering methods, three-dimensional scanning technology and Raindrop Company produced the inverse engineering software to finish the reverse three-dimensional modeling design of little bear punch. Applying Master CAM to set parameters, simulation run, and automatically generate NC code, in the vertical machining center, complex curved surface NC machining of the model can be finished. In engineering practice, it can improve work efficiency, reduce the labor intensity of product development, and reduce the artificial error of the design.


2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Kory Chang ◽  
Masakazu Soshi

Sliding guideways are often used as the foundation for linear motion in computer numerical control (CNC) machine tools due to their high damping capabilities especially for heavy duty machining applications. However, the traditional manufacturing process with grinding is time-consuming, and the product’s sliding performance has not been optimized nor clearly understood. In order to increase productivity, a machining center based manufacturing method with cubic boron nitride (CBN) milling tools was introduced and tested by researchers. While greatly reducing manufacturing time and cost, a rougher milled surface, in comparison to traditional grinding, is a possible concern for the performance as well as the life of sliding guideways. In this study, a novel planar honing process was proposed as a postprocess of CBN milling to create a finish surface on hardened cast iron sliding guideways used for CNC machine tools. A design of experiment (DOE) was conducted to statistically understand significant factors in the machining process and their relationship with surface topography. Effective planar honing conditions were discovered and analyzed with three-dimensional (3D) and two-dimensional surface parameters.


2012 ◽  
Vol 220-223 ◽  
pp. 385-388
Author(s):  
An Jiang Cai ◽  
Yan Jun Guo ◽  
Shi Hong Guo ◽  
Ming Wei Ding

CNC Milling Process for the complex characteristics, in order to solve how to quickly and effectively to provide a reasonable and optimal machining parameters of CNC milling process for technologist. The paper takes horizontal machining center DMC60H as a test platform and technological data of shell aluminum alloy hydraulic aircraft engine parts as a study. the paper establish management system of CNC milling parameters which was suitable for machinery manufacturing enterprises. The results showed that: The established parameters of CNC milling system can be better management of various CNC milling technology to effectively manage information and improve the CNC milling process information efficiency, has certain promotion effect to the production of the numerical control milling processing and the development of the manufacturing enterprises.


2013 ◽  
Vol 579-580 ◽  
pp. 276-282 ◽  
Author(s):  
Zhi Yan Ma ◽  
Guang You Yang ◽  
Xu Wu Su

Based on Virtual Numerical Control machining system (VNC), a new method of Augmented Numerical Control machining system (ANC) which aims at the realization of NC machining process simulation in real machining environment is put forward. The System inputs continuous video images of real NC processing environment through camera to identify and locate the major machining and positioning parts of real machine in the image stream. And the virtual parts of VNC will be matched to the corresponding real ones of real machining system to achieve the registration of ANC. The NC system drives the virtual machining models for processing through a real machine. On the other hand, the actual running information of CNC machine are imported into the ANC system to drive some models of process variables such as cutting force, material removal rate, chip shape, tool temperature, cutting tool wear. ANC provides the platform to integrate the geometry and physical simulation based on actual information from real CNC machining environment.


2014 ◽  
Vol 915-916 ◽  
pp. 236-239
Author(s):  
Man Yang ◽  
Hui Bin Li ◽  
Bao Yun Xu

For hypoid gear which processed by HFT (hypoid gear formate tilt) method, geometry parameters and machining parameters of hypoid gear were calculated by using Gleason card. According to the actual machining process and meshing principle, tooth surface equation was derived by coordinate transformation. Then the discrete coordinates points of tooth surface were obtained by using MATLAB tools and projection transformation principle, and data were saved in ibl format. At last the 3-demensional model of hypoid gear were established by importing the ibl format data in Pro/e.


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