A repair strategy based on tool path modification for damaged turbine blade

2020 ◽  
Vol 106 (7-8) ◽  
pp. 2995-3006
Author(s):  
Zhu Zheng-Qing ◽  
Zhang Yun ◽  
Chen Zhi-Tong
Keyword(s):  
Turbine Blade ◽  
Tool Path ◽  
Repair Strategy ◽  
Path Modification ◽  
Tool Path Modification

A Tool Path Modification Approach to Cutting Engagement Regulation for the Improvement of Machining Accuracy in 2D Milling With a Straight End Mill

2007 ◽  
Vol 129 (6) ◽  
pp. 1069-1079 ◽  
Author(s):  
M. Sharif Uddin ◽  
Soichi Ibaraki ◽  
Atsushi Matsubara ◽  
Susumu Nishida ◽  
Yoshiaki Kakino
Keyword(s):  
Cutting Force ◽  
Case Studies ◽  
Tool Path ◽  
Free Form ◽  
Geometric Accuracy ◽  
End Mill ◽  
Workpiece Surface ◽  
Engagement Angle ◽  
Path Modification ◽  
Tool Path Modification

In two-dimensional (2D) free-form contour machining by using a straight (flat) end mill, conventional contour parallel paths offer varying cutting engagement with workpiece, which inevitably causes the variation in cutting loads on the tool, resulting in geometric inaccuracy of the machined workpiece surface. This paper presents an algorithm to generate a new offset tool path, such that the cutting engagement is regulated at a desired level over the finishing path. The key idea of the proposed algorithm is that the semi-finish path, the path prior to the finishing path, is modified such that the workpiece surface generated by the semi-finish path gives the desired engagement angle over the finishing path. The expectation with the proposed algorithm is that by regulating the cutting engagement angle along the tool path trajectory, the cutting force can be controlled at any desirable value, which will potentially reduce variation of tool deflection, thus improving geometric accuracy of machined workpiece. In this study, two case studies for 2D contiguous end milling operations with a straight end mill are shown to demonstrate the capability of the proposed algorithm for tool path modification to regulate the cutting engagement. Machining results obtained in both case studies reveal far reduced variation of cutting force, and thus, the improved geometric accuracy of the machined workpiece contour.

scholarly journals Machining Time Reduction by Tool Path Modification to Eliminate Air Cutting Motion for End Milling Operation

2020 ◽  
Vol 14 (3) ◽  
pp. 459-466 ◽  
Author(s):  
Isamu Nishida ◽  
◽  
Keiichi Shirase
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Axial Direction ◽  
Contour Line ◽  
Product Model ◽  
Machining Time ◽  
High Productivity ◽  
Product Surface ◽  
Path Modification ◽  
Tool Path Modification

A method to uniquely calculate the tool path and to modify the tool path during air cutting motion to reduce the machining time is proposed. This study presents a contour line model, in which the product model is minutely divided on a plane along an axial direction, and the contour line of the cross-section of the product is superimposed. A method is then proposed to calculate the tool position according to the degree of interference between the product surface and the tool. Furthermore, this study proposes a technique to reduce the machining time by tool path modification during air cutting motion. This is determined by the geometric relationship between the product surface and the tool, and not based on cutting simulations. A cutting experiment was conducted to validate the effectiveness of the proposed method. Based on the results, it was confirmed that the difference in machining time between the tool path with modification and the tool path without modification was large. Moreover, the machining time was significantly reduced by the tool path modification. The results showed that the proposed method has good potential to perform customized manufacturing, and to realize both high productivity and reliability in machining operation.

Path Planning for Circular Cutter Envelop Milling of Steam Turbine Blade

2014 ◽  
Vol 989-994 ◽  
pp. 2908-2912
Author(s):  
Jian Jun Wang ◽  
Ke Wang ◽  
Qiong Wu
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Tool Path ◽  
Vertical Section ◽  
Surface Matching ◽  
Nurbs Surface ◽  
Processing Efficiency ◽  
Tool Paths ◽  
Blade Machining ◽  
Steam Turbine Blade

In order to solve the problem of poor steam turbine blade processing efficiency, and on the basis of analyzing the turbine blade surface and the existing processing methods, a model of circular cutter turbine blade machining is built. By comparing the tool paths of horizontal and vertical section envelope machining, choosing quasi-vertical cross section envelope machining method and utilizing the original datum and NURBS surface matching mathematic methods, this paper provides an algorithm of residual height calculating, and based on this, the tool path can be planned. Datum show that, the tool path of circular cutter machining blades is much longer than the tool path of ball-end cutter envelop milling machining blades, and the machining efficiency is also highly enhanced.

A Gouge-Free Tool Axis Reorientation Method for Kinematics Compliant Avoidance of Singularity in 5-Axis Machining

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Shuoxue Sun ◽  
Yuwen Sun ◽  
Yuan-Shin Lee
Keyword(s):  
Tool Path ◽  
Rotary Axes ◽  
Rotary Axis ◽  
Tool Axis ◽  
Effective Manner ◽  
Singular Configuration ◽  
The Stability ◽  
Tool Motion ◽  
Path Modification

When a cutter traverses a region local to the singularity in 5-axis machining, the stability of machine tool motion may be violated and inevitably lead to a reduction in machining quality and accuracy. In this paper, the underlying cause of the singular machine behaviors is first investigated by differentiating tool path motions, on the basis of the tool path motion expressions in part and machine coordinate systems. A further investigation indicates abrupt kinematic changes to be inevitable when the rotary axes approach a singularity. To eliminate such possible singular risks in 5-axis machining, a local tool path modification method is proposed by adjusting the two rotary axes out of a singular configuration. The critical kinematics smoothing and the consequent gouging concerns resulting from reorientation are comprehensively incorporated in the process of singularity avoidance, by means of a novel tool orientation optimization model. Specifically, the algorithm starts with the determination of an appropriate adjustment range in a simple yet effective manner, and then the primary rotary axis is adjusted in a constrained region away from zero, so as to avoid singularity. After that, the second rotary axis is accordingly adjusted, with no gouging requirements being violated. In this way, singularity problems in 5-axis machining are solved, and both the machine axes kinematics and surface gouging errors are under control. Machining simulation and laboratory experiments were conducted to validate the effectiveness of the proposed method.

A New One-Side Finish Machining Method for Profile of Globoidal Indexing Cam in High Speed

2009 ◽  
Vol 626-627 ◽  
pp. 611-616
Author(s):  
X.F. Tang ◽  
Wei He ◽  
Y.S. Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
New Method ◽  
Practical Calculation ◽  
Machined Surface ◽  
Finish Machining ◽  
Cam Mechanism ◽  
Cad Cam ◽  
Meshing Characteristics ◽  
Path Modification

A new one-side finish machining method for the profile of globoidal indexing cam in high speed, which modifies the tool path of traditional enveloping method, was put forward. The new method is useful for overcoming the defects caused by traditional enveloping method, can realize one-side machining of globoidal indexing cam, can improve the machined surface quality and the meshing characteristics of the cam mechanism. The practical calculation formulas of tool path modification is given, which can be used in developing the CAD/CAM software of the globoidal indexing cam. The new method has great practical value.

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