scholarly journals Five-Axis Tool Path Generation of Injection Mold Represented by T-Spline Surface

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ce Shang ◽  
Hongyao Shen ◽  
Jianzhong Fu ◽  
Yangfan Sun ◽  
Shuhua Yue ◽  
...  
Keyword(s):  
Injection Molding ◽  
Tool Path ◽  
Order Continuity ◽  
Freeform Surfaces ◽  
Tool Paths ◽  
Spline Surface ◽  
Surface Models ◽  
Processing Order ◽  
Patch Boundary ◽  
Five Axis

Injection molding is widely used in industries to produce polymeric products. At present, compound NURBS surfaces are commonly used to represent freeform surfaces in mold models. This work uses T-spline surface with extraordinary control points instead of NURBS to represent freeform surfaces in mold models. Compared with NURBS, T-splines’ higher-order continuity facilitates the mold quality control especially at the patch boundary. And, its patch layout information can be utilized for tool path planning. We propose an algorithm to determine the patch processing order and generate nonretraction tool path for T-spline surface models. The tool paths are generated patch by patch using isoparametric strategy. Actual machining and injection molding experiments have been conducted. The result shows the feasibility of the proposed method, and the final product is in good quality.

Study of The Tool Path Generation Method of an Ultra-Precision Spherical Complex Surface Based on a Five-Axis Machine Tool

2021 ◽  
Author(s):  
Tianji Xing ◽  
Xuesen Zhao ◽  
Zhipeng Cui ◽  
Rongkai Tan ◽  
Tao Sun
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Spherical Surface ◽  
Tool Path Generation ◽  
Path Generation ◽  
Tool Paths ◽  
Spherical Surfaces ◽  
Spherical Complex ◽  
Ultra Precision ◽  
Five Axis

Abstract The improvement of ultra-precision machining technology has significantly boosted the demand for the surface quality and surface accuracy of the workpieces to be machined. However, the geometric shapes of workpiece surfaces cannot be adequately manufactured with simple plane, cylindrical, or spherical surfaces because of their different applications in various fields. In this research, a method was proposed to generate tool paths for the machining of complex spherical surfaces based on an ultra-precise five-axis turning and milling machine with a C-Y-Z-X-B structure. Through the proposed tool path generation method, ultra-precise complex spherical surface machining was achieved. First, the complex spherical surface model was modeled and calculated, and then it was combined with the designed model to generate the tool path. Then the tool paths were generated with a numerically controlled (NC) program. Based on an ultra-precision three-coordinate measuring instrument and a white light interferometer, the machining accuracy of a workpiece surface was characterized, and t[1]he effectiveness of the provided tool path generation method was verified. The surface roughness of the machined workpiece was less than 90 nm. Furthermore, the surface roughness within the spherical region appeared to be less than 30 nm. The presented tool path generation method in this research produced ultra-precision spherical complex surfaces. The method could be applied to complex spherical surfaces with other characteristics.

Tool path generation for ultra-precision polishing of freeform optical surfaces in an off-axis three-mirror imaging system

2015 ◽  
Vol 231 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Dengpeng Huang ◽  
Lei Zhang ◽  
Shijun Ji ◽  
Ji Zhao
Keyword(s):  
Tool Path ◽  
Imaging System ◽  
Concentric Circle ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Primary Mirror ◽  
Tool Paths ◽  
Ultra Precision

The optical performance of the off-axis three-mirror imaging system can be greatly improved using freeform surfaces. This article focuses on the polishing of the primary mirror and tertiary mirror in an off-axis three-mirror imaging system. The primary mirror and tertiary mirror are fabricated on one monolithic substrate and described by non-uniform rational B-spline–based freeform surfaces. The separated and integrated polishing strategies are presented for polishing the two mirrors on the four-axis computer numerical control polishing platform. A tool path generation approach is proposed for polishing of the non-uniform rational B-spline–based freeform surface. Three kinds of the tool paths are given for ultra-precision polishing of the primary mirror and tertiary mirror with the freeform surfaces. The concentric circle path and the approximately concentric circle path are generated for polishing two mirrors separately, while the spiral path is calculated for integrated polishing of two mirrors simultaneously. The polishing tool posture along the planned tool paths is also analyzed. The ultra-precision polishing experiments of the primary mirror and tertiary mirror on the four-axis computer numerical control polishing platform are performed to verify the proposed approach for tool path generation.

Path Planning for Motion Control of Hexapod Machines

2001 ◽  
Author(s):  
Zhiming Ji ◽  
Zhenqun Li
Keyword(s):  
Path Planning ◽  
Machine Tools ◽  
Tool Path ◽  
Local Planning ◽  
Tool Path Planning ◽  
Tool Paths ◽  
Condition Optimization ◽  
Planning Methods ◽  
Tool Motion ◽  
Five Axis

Abstract The dramatic departure in structure of the hexapod machine tools from the traditional five-axis machines leads to the question: can the planning and control methods for the traditional CNC machines be used for the hexapod machine tools? We studied several tool motion characteristics, such as Jocabian matrices, path tracking errors and the extra degree of freedom (e-DOF), and found that the traditional five-axis planning methods cannot take into consideration of the kinematics performance variation and the e-DOF in a hexapod. A kinematics-based tool path planning scheme for the hexapods is therefore proposed. It combines the traditional tool path planning with the kinematic condition optimization. The optimization is a two-step process. First a high accuracy zone of the workspace is identified globally for the placement of the part. Then a set of 5-DOF tool paths is generated and extended to a set of 6-DOF tool paths based on the local planning of e-DOF. Finally the relationship between the e-DOF and the stiffness of the Hexapods, another factor in the use of e-DOF, are discussed.

Generation of Optimal Tool-Paths for Five-Axis Finish Milling of Free-Form Surfaces

2012 ◽  
Vol 500 ◽  
pp. 440-446
Author(s):  
Lin Geng ◽  
Yun Feng Zhang
Keyword(s):  
Genetic Algorithm ◽  
Tool Path ◽  
Free Form ◽  
Machining Efficiency ◽  
Interference Avoidance ◽  
Tool Paths ◽  
Modified Genetic Algorithm ◽  
Novel Method ◽  
Five Axis ◽  
Free Form Surfaces

In this paper, a novel method is proposed to generate optimal 5-axis finish tool-paths regarding joint movements and machining efficiency. A modified genetic algorithm is used to search for the optimal posture sequence along a tool-path while interference avoidance and surface finish quality act as constraints. Case studies are then provided to prove the effectiveness of the algorithm.

A New Architecture of Tool Path Generation for Five-Axis Control Machining

2005 ◽  
Vol 291-292 ◽  
pp. 501-506 ◽  
Author(s):  
K. Nakamoto ◽  
K. Shirase ◽  
Akifumi Morishita ◽  
E. Arai ◽  
T. Moriwaki
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Manufacturing Systems ◽  
Tool Path ◽  
Cutting Parameters ◽  
Tool Paths ◽  
Nc Program ◽  
Digital Copy ◽  
Copy Milling ◽  
Five Axis

NC machine tools, which are widely employed in manufacturing systems, are basically driven by NC programs. However, it requires extensive amount of time and efforts to generate high quality tool paths before a machining operation. An NC program for five-axis control machining is more difficult to generate because the motion of machine tool is more complicated. In this paper, a new architecture is proposed to autonomously control the machine tool without an NC program for more rapid and flexible machining. A technique called digital copy milling is developed to generate the tool paths in real time based on the principle of copy milling. It means that the cutting parameters can be adaptively controlled in order to maintain stable cutting process and to avoid the cutting troubles. In the experimental verification, the improved digital copy milling system for five-axis control milling successfully detected and avoided tool collision in real-time.

Smooth Cutting Operation Strategy for High Finishing Machining

2014 ◽  
Vol 875-877 ◽  
pp. 896-900
Author(s):  
Xiao Fei Bu ◽  
Hu Lin ◽  
Long Chen
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Machining Process ◽  
Path Generation ◽  
Tool Paths ◽  
Constant Scallop Height ◽  
Simulation And Experiment ◽  
Cutting Operation ◽  
Five Axis ◽  
Finishing Machining

High finishing machining tool path generation methods are usually adopted for five-axis computer numerically controlled machining of sculptured surface parts. The quality of the high finishing machining has an important effect on that of the surface. In this paper, a high finishing machining tool path generation method is introduced to generate an optimal tool path. The initial tool path is firstly created based on the constant scallop height, then the derived tool paths are generated as a kind of the diagonal curve by the initial tool path, and at last, the tool path smoothing algorithm is applied to the generated tool path. This path algorithm can ensure higher level of smooth of the surface been machined. Finally, the results of simulation and experiment of the machining process are given to verify the smooth and applicability of the proposed method.

Optimal Workpiece Setup for Time-Efficient and Energy-Saving Five-Axis Machining of Freeform Surfaces

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Ke Xu ◽  
Kai Tang
Keyword(s):  
Energy Consumption ◽  
Alternative Energy ◽  
Tool Path ◽  
Machining Time ◽  
Freeform Surfaces ◽  
Significant Saving ◽  
Energy Consumption Model ◽  
Consumption Model ◽  
Workpiece Setup ◽  
Five Axis

Energy consumption in five-axis machining of freeform surfaces can be considerably large for large-size parts. This paper presents a study on how to setup the workpiece in order to minimize the energy consumption without modifying the toolpath itself. For an arbitrary freeform workpiece, the way how it is setup on the working table highly affects the machine's kinematic behavior, which dominates the overall processing time and energy consumption. Taking into account the speed and acceleration limit of each axis of the machine, we first establish the energy consumption model as a function of the workpiece setup. However, this original model involves certain critical physically pertinent coefficients (such as the moment of inertial of a rotary table) which are usually unavailable in practice. Instead, by exploring insightful geometric characteristics of the five-axis machine, an alternative energy consumption model is established which is independent of those hard-to-obtain coefficients. A simple algorithm is then designed to optimize this model. Both computer simulations and physical cutting experiments demonstrate that, when compared with an arbitrary setup, the optimized workpiece setup is able to achieve a significant saving (as much as 50%) in both energy consumption and total machining time, both using a same tool path.

Surface Generation and Machining With Rational B-Splines for Turbomachinery Components

2002 ◽  
Author(s):  
Der Min Tsay ◽  
Chien Wen Chen ◽  
Jiun Ren Chen
Keyword(s):  
Tool Path ◽  
Surface Generation ◽  
Approximation Procedure ◽  
Least Squares Approximation ◽  
Practical Application ◽  
B Splines ◽  
Tool Paths ◽  
Compressor Impeller ◽  
Geometric Deviations ◽  
Five Axis

To five-axis point mill turbomachinery components, a least squares approximation procedure for generating tool paths in terms of parametric rational B-splines is presented. The detailed processes of using the appropriate parameters of rational B-splines that will reduce the amount of geometric deviations between the designed and machined part surfaces are proposed. Compared to a traditional linear tool path, a rational B-spline tool path can substantially reduce the number of blocks on machine controllers without compromising the accuracy. As a result, the machining efficiency and machine dynamic behavior can be improved. Numerical and experimental results are given to show such improvements. A practical application example for machining a centrifugal compressor impeller with 12 blades is also illustrated to demonstrate the reliability and usefulness of the developed procedure.

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