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.

A New Method of Torque Compensation for High Speed Indexing Cam Mechanism

1999 ◽  
Vol 121 (2) ◽  
pp. 319-323 ◽  
Author(s):  
Teng Guilan ◽  
Fu Haibo ◽  
Zhou Weiyi
Keyword(s):  
Kinetic Energy ◽  
High Speed ◽  
Output Shaft ◽  
New Method ◽  
Linkage Mechanism ◽  
Energy Fluctuation ◽  
Positioning Accuracy ◽  
Input Shaft ◽  
Cam Mechanism

Severe vibration and poor positioning accuracy may occur in an indexing cam mechanism operating at a high speed. Torque fluctuation of the input shaft and the resulting fluctuation of kinetic energy of the mechanism may be the major cause of the vibration. In this paper a method is proposed to minimize the fluctuation by using a so-called “speed-varying flywheel” that produces an opposite kinetic energy fluctuation that can counteract the effect of the energy fluctuation. The flywheel is installed on the output shaft of an additional cam-linkage mechanism. The parameter of the cam-linkage mechanism is optimized. An example is given to demonstrate the effectiveness of this method.

Development of Real-Time Look-Ahead Methodology Based on Quintic PH Curve with G2 Continuity for High-Speed Machining

2013 ◽  
Vol 464 ◽  
pp. 258-264 ◽  
Author(s):  
Jing Shi ◽  
Qing Zhen Bi ◽  
Yu Han Wang ◽  
Gang Liu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Tool Path ◽  
Approximation Error ◽  
Machining Process ◽  
Transition Curve ◽  
Look Ahead ◽  
Cad Cam ◽  
Feedrate Fluctuation ◽  
Ph Curve

Curving tool paths composed of straight lines, which are often represented as G01 blocks, are still the most widespread format form in the machining process chain of CAD/CAM/CNC. At the junctions between consecutive segments, the tangency and curvature discontinuities may lead to feedrate fluctuation and acceleration oscillation, which would deteriorate the machining efficiency and quality. In this paper, a real-time look-ahead interpolation methodology is proposed, which adopts a curvature-continuous PH curve as a transition to blend corner at the junction of adjacent lines in the tool path. The blending algorithm can guarantee the approximation error exactly, and the control points of the curve can be calculated analytically. On the other hand, the arc length and the curvature of the transition curve, which are important items in speed planning, also have analytical expressions. All the advantages are the guarantee of calculation efficiency during the interpolation. Except for a curvature-continuous tool path, our look-ahead algorithm adopts a speed planning window strategy to achieve a balance between the calculation capabilities and the real-time interpolation requirements. In this window, the corner transition algorithm and speed planning are implemented simultaneously and dynamically during the interpolation. By defining the width of this window, which is actually the number of linear segments contained in this window, can adjust the time consuming of speed planning. Simulation and experiments on our own developed CNC platform are conducted. The results demonstrate the feasibility and efficiency of the proposed algorithms.

HSM Strategies of CAD/CAM Systems — Part I Tool Path Generation

2010 ◽  
Vol 426-427 ◽  
pp. 520-524 ◽  
Author(s):  
Song Lin Ding ◽  
John Mo ◽  
D. Yang
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Tool Path ◽  
Tool Path Generation ◽  
Path Generation ◽  
Cnc Machine ◽  
Technical Requirements ◽  
Cad Cam ◽  
High Feed ◽  
Cutting Processes

Owning to the ultra high feed rate and spindle speed, tool path patterns which are less important in conventional metal cutting processes becomes critical in High Speed Machining (HSM). Without an appropriate tool path strategy HSM can not be fully implemented even though the CNC machine has HSM potentials. In practice attentions are usually drawn to advanced hardware components; tool path pattern catering to HSM is often overlooked. This paper introduces the principles of tool path generation for HSM. Essential properties of HSM and its technical requirements on the CAD/CAM system are summarized. The state-of-the-art technologies and practice-oriented tool path generation methodologies are presented.

Cutter Location Generation Via Development of UG/OPEN API for Turbine Blades Machining

2006 ◽  
Vol 532-533 ◽  
pp. 785-788
Author(s):  
Tian Li ◽  
Wu Yi Chen ◽  
Rui Qiu Wang
Keyword(s):  
Tool Path ◽  
Turbine Blades ◽  
Cnc Milling ◽  
Machined Surface ◽  
Tool Positioning ◽  
Positioning Strategy ◽  
New Strategy ◽  
Cad Cam ◽  
Open Api ◽  
Matching Strategy

The CAD/CAM software UGNX3 was used to implement tool positioning strategy in CNC milling. The Sturz strategy embedded in UG was replaced by curvature matching strategy using the interface of the UG/OPEN API. The feed direction was constrained along u direction of the machined surface. An extra angle was added to eliminate the interference between the cutter and the surface and some additional cutter locations were calculated to ensure the whole face to be machined. After the previous algorithms applied in computer program, an optimized tool path was generated. By the method of ZIG-ZAG mode, the efficiency was increased. The new strategy was verified by the simulation and machining experiment. It showed that combining the new strategy in UG was feasible. The precision and efficiency could thus be improved.

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.

HSM Strategies of CAD/CAM Systems — Part II Industrial Application

2010 ◽  
Vol 426-427 ◽  
pp. 559-563 ◽  
Author(s):  
Song Lin Ding ◽  
John Mo ◽  
D. Yang
Keyword(s):  
Industrial Application ◽  
High Speed ◽  
Tool Path ◽  
State Of The Art ◽  
High Speed Machining ◽  
Advantages And Disadvantages ◽  
Software Packages ◽  
Cad Cam ◽  
Increasing Demand ◽  
Cam Systems

Over one hundred types of commercial CAD/CAM systems are currently used in various industries. To meet the increasing demand for high speed machining (HSM) from shop floors most of these systems have integrated functions for the generation of HSM tool path. However, the strategies they adopted and the qualities of HSM tool path generated by these packages differ significantly from system to system. This paper reviews the state-of-the-art HSM strategies adopted by industrial CAD/CAM systems. The review is based on sixteen widely used software packages which include both advanced systems and the relatively concise packages. HSM features of each system are summarized; HSM strategies adopted by those systems are presented; the advantages and disadvantages are discussed as well.

Geometrical Feature Analysis of the Movement of the New Type of Double-Hemisphere Rolling Gear Globoidal Cam Indexing Mechanism

2013 ◽  
Vol 706-708 ◽  
pp. 1379-1384 ◽  
Author(s):  
Xue Heng Tao ◽  
Hui Hui Wang ◽  
Jin Shi Cheng ◽  
Ji Xin Yang ◽  
Xue Jun Wang
Keyword(s):  
High Speed ◽  
Fundamental Principle ◽  
Feature Analysis ◽  
Geometrical Feature ◽  
Cam Mechanism ◽  
Pure Rolling ◽  
New Type ◽  
Meshing Characteristics ◽  
Indexing Mechanism ◽  
Precision Motion

A novel kind of double-hemisphere rolling gear globoidal indexing cam mechanism was proposed，which can satisfy high speed and precision motion requirement. Fundamental principle and meshing characteristics were studied based on conjugate surface principle. Pure rolling of the transmision mechanism was applicated in engineering，and combination property was improved.

scholarly journals Enabling Advanced CNC Programming with openNC Controllers for HSM Machines Tools

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Jean-Yves Hascoet ◽  
Matthieu Rauch
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Control Algorithms ◽  
Process Data ◽  
Path Control ◽  
Test Platform ◽  
Cad Cam ◽  
Cnc Programming ◽  
Advanced Tool ◽  
Online Process

AbstractThe manufacturing area has benefited from various progresses over the last decades, such as High Speed Machining (HSM), but CNC programming is still based on dated practices and habits with a segmented unidirectional CAD/CAM/CNC data chain. Decision power is limited at the NC controller stage and online process optimization is difficult. In contrast, advanced programming approaches, such as STEP-NC [9], aim to unify the product/ process data within a consistent environment from design to machining. Hence, openNC controller solutions which allow access to their internal algorithms, have emerged. It is consequently possible to implement new tool path control algorithms that respond directly to the actual machining condition. This paper focuses on the interest of openNC controllers to develop advanced programming approaches forHSMprocesses. Themajor drawbacks of legacy controllers in the implementation of advanced tool path generation methods are discussed and the most significant openNC projects are reviewed. An integrated test platform has been developed. The advanced HSM programming methods enabled by this openNC controller are discussed.

Advanced CNC Programming Methods for Multi-Axis Precision Machining

2013 ◽  
Vol 581 ◽  
pp. 478-484 ◽  
Author(s):  
Sergey N. Grigoriev ◽  
Andrey A. Kutin ◽  
Mikhail Turkin
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Turbine Blades ◽  
Machining Accuracy ◽  
Machining Time ◽  
High Speed Cutting ◽  
Nc Programming ◽  
Custom Made ◽  
Cad Cam ◽  
Cnc Programming

This paper presents a method to simultaneously increase the accuracy and decrease the calculation time for complex tool path programming in multi-axis machining centers. Examples of complex parts requiring such complex tool paths include various kinds of turbine blades, pump-forcing augers, teeth surfaces, etc. It explains the creation of topological structures on the basis of analytical spline curves with floating range definitions. The method for tool path calculation accommodates the specific requirements for multi-axis milling. The algorithms developed are the foundation for the CAD/CAM software that allows for NC programming and machining on 5-axis centers employing any design model. Industrial tests reveal a 70-80% reduction of NC programming time of parts with complex surfaces, reduced machining time of approximately 40-50% using basic high-speed cutting methods and custom-made tools. The advanced methods of NC programming result in substantially increasing machining accuracy.

Effect of Tool Path Strategies in Pocket Milling of Aluminium Epoxy

2014 ◽  
Vol 903 ◽  
pp. 15-20 ◽  
Author(s):  
Rusdi Mat Song ◽  
Safian Sharif ◽  
Ahmad Yasir Md Said ◽  
Mohd Tanwyn Mohd Khushairi
Keyword(s):  
Computer Aided Design ◽  
High Speed ◽  
Tool Path ◽  
High Speed Steel ◽  
Cutting Parameters ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Time ◽  
Pocket Milling ◽  
Cad Cam

Selection of the most suitable tool path strategy is very essential during machining especially in computer aided design and manufacture (CAD/CAM) as well as computer numerical control (CNC) machining. Existence of various tool path strategies to be applied on advanced composite materials such as aluminium epoxy required extensive researches in determining the best combination of tool path and cutting parameters for better machinability performance. Pocket milling of aluminium epoxy specimen via CAD/CAM was conducted in this study to investigate the effect of three types of tool path strategies namely Inward Helical, Outward Helical and Back and Forth. Uncoated high speed steel (HSS-Co8) ball end mill was used throughout the experiments. The machining responses that were evaluated include machining time, tool wear rate, tool life and surface finish of the machined pockets. In general, the effect of tool path strategy was highly significant on the machining responses and results showed that Back and Forth strategy offered the best machinability results when compared to the other strategies.

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