Boundary-conformed machining of turbine blades

2005 ◽  
Vol 219 (3) ◽  
pp. 255-263 ◽  
Author(s):  
S Ding ◽  
D C H Yang ◽  
Z Han
Keyword(s):  
Computer Aided Design ◽  
Tool Path ◽  
Flow Line ◽  
Turbine Blades ◽  
Free Form ◽  
Implementation Processes ◽  
Tool Marks ◽  
Tool Paths ◽  
Continuous Boundary ◽  
Free Form Surfaces

Boundary-conformed machining is a new method to mill free-form surfaces with tool paths that reflect the natural shapes of the surfaces. It is suitable for the machining of turbine blades taking into account the direction of tool marks left on the vanes. To facilitate this type of machining, this paper introduces an application of the ‘boundary-conformed algorithm’ to generate continuous boundary-conformed flow line tool paths for the milling of blade surfaces. With this approach, the initial segment of the flow line tool paths is along the top edges of the blade while the final segment follows the intersection curves between the blade and the hub surface. The intermediate segments cover the surface by changing smoothly from the initial tool path to the final tool path. The two opposite sides of the blade, which are two trimmed surfaces, are machined together continuously from top to bottom with these continuous boundary-conformed tool paths. This method has been successfully integrated into an industrial computer-aided design and manufacture system (Pro/Engineer) by using Pro/Toolkit. A detailed algorithm and implementation processes have been introduced.

Adaptive Tool Path Planning Strategy for 5-Axis CNC Machining of Free Form Surfaces

2019 ◽  
Author(s):  
Hrishikesh Mane ◽  
S. S. Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Memory Storage ◽  
Free Form ◽  
Cnc Machine ◽  
Planning Strategy ◽  
Part Quality ◽  
Tool Paths ◽  
Path Topology ◽  
Free Form Surfaces

Abstract This paper presents a curvature based adaptive iso-parametric strategy for the efficient machining of free form surfaces on 5-axis CNC machine using the flat end mill tool. One iso-parametric boundary of the surface is selected as the initial tool path. Set of cutter contact (CC) points are chosen adaptively on the initial tool path considering desired profile tolerance. Adjacent iso-parametric tool paths are computed adaptively based on the scallop height constraint unlike the traditional iso-parametric approach. The path topology is post-processed to generate the part program for 5-axis CNC machine in ISO format. The system was rigorously tested for various case studies by comparing the results with the traditional 5-axis iso-parametric tool path strategy, iso-scallop strategy and iso-planar strategy of a commercial software. Our system was found to generate efficient tool paths in terms of part quality, productivity and memory storage compared to the conventional strategies.

Spiral Tool Path Planning Using Eccentric Parameters

2014 ◽  
Author(s):  
Baosu Guo ◽  
Qingjin Peng ◽  
Xiaosheng Cheng ◽  
Ning Dai
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Free Form ◽  
Tool Path Planning ◽  
Inverse Mapping ◽  
Machined Surface ◽  
Tool Paths ◽  
Spiral Tool Path ◽  
Free Form Surfaces ◽  
The Relationship

Free-form surfaces can be machined continuously with minimum tool retractions and at the high speed by following a spiral tool path. This paper presents an improved planning method of the spiral tool path using eccentric parameters for machining free-form surfaces. The relationship between a 3D machined surface and the 2D circular region is established through the conformal mapping. In order to generate an even path, eccentric parameters are used in 2D parametric circular regions to optimize the path interval. The proposed method produces planar spiral segments as a diagonal curve between every two adjacent parametric tool paths. A 2D spiral tool path is gained by linking spiral segments in sequence. Inverse mapping of the 2D spiral tool path onto the machined surface generates the 3D spiral tool path. The main processes of the proposed method include reducing dimensions of free-form surfaces, calculating the eccentric parametric tool path, and generating the planar diagonal spiral tool path. Some applications are used to verify the proposed methods. The proposed method allows the start point to be arbitrary and generates more even tool paths than the existing methods by introducing the mapping distortion.

Constant Scallop-height Machining of Free-form Surfaces

1994 ◽  
Vol 116 (2) ◽  
pp. 253-259 ◽  
Author(s):  
K. Suresh ◽  
D. C. H. Yang
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Free Form ◽  
Machining Time ◽  
Scallop Height ◽  
Location Data ◽  
Tool Paths ◽  
Novel Approach ◽  
Constant Scallop Height ◽  
Free Form Surfaces

A novel approach for the NC tool-path generation of free-form surfaces is presented. Traditionally, the distance between adjacent tool-paths in either the Euclidean space or in the parametric space is kept constant. Instead, in this work, the scallop-height is kept constant. This leads to a significant reduction in the size of the CL (cutter location) data accompanied by a reduction in the machining time. This work focuses on the zig-zag (meander) finishing using a ball-end milling cutter.

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.

Tool-Path Scheduling for Free-Form Surface Based on MasterCAM

2014 ◽  
Vol 556-562 ◽  
pp. 1400-1403 ◽  
Author(s):  
Wen Jing Ren ◽  
Jian Yun He ◽  
Yuan Yu
Keyword(s):  
Tool Path ◽  
Flow Line ◽  
Freeform Surface ◽  
Free Form ◽  
Milling Machine ◽  
Tool Paths ◽  
Nc Milling ◽  
Free Form Surface ◽  
Path Scheduling

The tool-path generating methods of roughing and finishing provided by MasterCAM were systematically analyzed including their features and applications. Then a blade with freeform surface milled by different tool-paths was simulated. According to the comparison of simulation effects and information, the flow-line tool-path was proposed to be optimal for machining blade with freeform surface. Finally, the blade was finished with optimal tool-path using a 3-axis NC milling machine.

Iso-phote Based Tool-path Generation for Machining Free-form Surfaces

1999 ◽  
Vol 121 (4) ◽  
pp. 656-664 ◽  
Author(s):  
Zhonglin Han ◽  
Daniel C. H. Yang
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Free Form ◽  
Normal Vector ◽  
Path Generation ◽  
Reference Vector ◽  
Tool Paths ◽  
Offset Curves ◽  
Fixed Reference ◽  
Free Form Surfaces

This paper presents a novel approach for generating efficient tool paths in machining free-form surfaces. Concept of iso-phote is used to facilitate tool-path generation. An iso-phote is defined as a region on a surface where the normal vector does not differ by more than a prescribed angle from a fixed reference vector. The boundary curves of the iso-phote, called iso-inclination curves, are numerically generated and are served as the initial master tool paths. These iso-inclination curves are then projected to a 2D plane which is perpendicular to the fixed reference vector. 2D curve offsetting of the projected iso-inclination curve is then performed. The resulted 2D offset curves are projected back to 3D surface to form final tool paths. The resulted tool paths can guarantee the satisfaction of machining tolerance requirements. A comparison study of this iso-phote based machining with the conventional iso-parametric machining and the iso-planar machining shows favorite result for the new approach.

An Effective Approach to Approximating 2-D Free-Form Curve Offsets for B-Spline NC Tool Paths With Offset Error Globally Bounded

2010 ◽  
Author(s):  
Maqsood A. Khan ◽  
Zezhong C. Chen
Keyword(s):  
Computer Aided Design ◽  
Tool Path ◽  
Error Function ◽  
Industrial Applications ◽  
Cnc Machining ◽  
Free Form ◽  
Control Points ◽  
Base Function ◽  
B Spline ◽  
Tool Paths

The topic of representing the offset of a 2-D B-spline curve in the same form has been under research for a long time, and it has many industrial applications, especially, in NC tool path generation for pocketing. For B-spline tool paths, it is often required that the tool paths have fewer control points, lower base function degree, and higher geometric accuracy. However, the existing methods often generate the offsets of 2-D free-form curves in the form of B-spline curves with high function degree and many control points. Although these offsets are useful in computer-aided design, they are inappropriate for the use of CNC machining. To address the problems in order to generate high quality B-spline tool paths, this original work formulates an error function of the offset approximation and then constructs a NURBS curve to globally bound the errors. By checking the maximum coefficient of the bounding curve, the upper bound of all the approximated offset errors is found and the errors can be reduced by adding more offset points at the appropriate locations. The proposed new approach is more efficient, and the resulting offsets in B-spline are more accurate with fewer control points and lower function degree. It is useful to generate B-spline tool paths for CNC pocketing, and has potential for other applications in industry.

Five-Axis-Grinding With Toric Tools: A Status Review

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Berend Denkena ◽  
Anke Turger ◽  
Leif Behrens ◽  
Thomas Krawczyk
Keyword(s):  
Computer Aided Design ◽  
Tool Path ◽  
Free Form ◽  
Aviation Industry ◽  
Tool Geometry ◽  
Curved Surfaces ◽  
Shape Accuracy ◽  
Computer Aided ◽  
Five Axis ◽  
Free Form Surfaces

Free form surfaces are used in various applications, such as in the aviation industry, in the medicine, or for tool and die making. Compressor blades as well as knee prostheses and dies have complex curved surfaces. Five-axis grinding is a possibility to machine such curved surfaces in a high shape accuracy and surface quality. The use of this technology depends on a high degree of the operational background. Furthermore, the complexity of the tool path generation requires the use of computer-aided design/computer aided manufacturing (CAD/CAM) systems. This technical review gives an overview about state of the art of five-axis grinding and presents results, which can close some scientific lacks. Models were developed to predict the surface roughness and material removal dependent on the process parameters. Additionally, the relationship between tool geometry, shape accuracy as well as contact conditions is discussed.

Automatic Generation of Anisotropic Patterns of Geometric Features for Industrial Design

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Diego Andrade ◽  
Ved Vyas ◽  
Kenji Shimada
Keyword(s):  
Boundary Conditions ◽  
Computer Aided Design ◽  
Industrial Design ◽  
Automatic Generation ◽  
Free Form ◽  
Geometric Features ◽  
Target Domain ◽  
Metric Tensor ◽  
Target Region ◽  
Free Form Surfaces

While modern computer aided design (CAD) systems currently offer tools for generating simple patterns, such as uniformly spaced rectangular or radial patterns, these tools are limited in several ways: (1) They cannot be applied to free-form geometries used in industrial design, (2) patterning of these features happens within a single working plane and is not applicable to highly curved surfaces, and (3) created features lack anisotropy and spatial variations, such as changes in the size and orientation of geometric features within a given region. In this paper, we introduce a novel approach for creating anisotropic patterns of geometric features on free-form surfaces. Complex patterns are generated automatically, such that they conform to the boundary of any specified target region. Furthermore, user input of a small number of geometric features (called “seed features”) of desired size and orientation in preferred locations could be specified within the target domain. These geometric seed features are then transformed into tensors and used as boundary conditions to generate a Riemannian metric tensor field. A form of Laplace's heat equation is used to produce the field over the target domain, subject to specified boundary conditions. The field represents the anisotropic pattern of geometric features. This procedure is implemented as an add-on for a commercial CAD package to add geometric features to a target region of a three-dimensional model using two set operations: union and subtraction. This method facilitates the creation of a complex pattern of hundreds of geometric features in less than 5 min. All the features are accessible from the CAD system, and if required, they are manipulable individually by the user.

Application of Convex Hull for Tool Interference Avoidance in 5-Axis CNC Machining

1996 ◽  
Author(s):  
Yuan-Shin Lee ◽  
Tien-Chien Chang
Keyword(s):  
Convex Hull ◽  
Tool Path ◽  
Correction Method ◽  
Nc Machining ◽  
Cnc Machining ◽  
Free Form ◽  
Interference Avoidance ◽  
Tool Interference ◽  
Free Form Surface ◽  
Free Form Surfaces

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.

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