Machining-features of the workplace are described by using of the object-oriented （O-O） technology. Geometrical machining-features are recognized in the given cut region by using the maximum membership priciple abou...Machining-features of the workplace are described by using of the object-oriented （O-O） technology. Geometrical machining-features are recognized in the given cut region by using the maximum membership priciple about the fuzzy set. Depending on the IF-THEN rule and the fuzzy matching method, the rough information of the machining-process for high-speed milling （HSM） is extracted based on the database of machining-process for HSM. The optimization model of machining-process scheme is established to obtain shorter cut time, lower cost or higher surface quality. It is helpful to form successful cases for HSM. NC programming for HSM is realized according to optimized machining-process data from HSM cases selected by the optimization model and the extracted information of machining-process.展开更多
Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC verti...Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC vertical milling machine. A unique method is used for simulating the cutting process and displaying the three dimensional images. This method not only simplifies greatly the treatment of the hidden line but also creates a “photograph effect” image. The program is written in Visual B.展开更多
Tool path generated by space-filling curve always turns frequently causing trembling to machine,reducing toollife and affecting workpiece quality. Length and generation time of tool paths are both relatively long. In ...Tool path generated by space-filling curve always turns frequently causing trembling to machine,reducing toollife and affecting workpiece quality. Length and generation time of tool paths are both relatively long. In order to solve these problems,a toolpath generation method of NC milling based on space-filling curve is proposed. First,T-spline surface is regarded as the modeling surface,the grid,which is based on the limited scallop-height,can be got in the parameter space,and the influence value of grid node is determined. Second,a box is defined and planned,and the tool paths are got preliminarily,which is based on minimal spanning tree; Finally,based on an improved chamfering algorithm,the whole tool paths are got. A simulation system is developed for computer simulation,and an experiment is carried out to verify the method. The results of simulation and experiment show that the method is effective and feasible,and length and time of the tool paths are reduced.展开更多
The methods for reducing interface aperture inconsistency are studied in NC orbital milling(NCOM)of CFRP/Ti6Al4V laminates with coarse pitch.Comparative experiments show burr,aperture inconsistency and error are typic...The methods for reducing interface aperture inconsistency are studied in NC orbital milling(NCOM)of CFRP/Ti6Al4V laminates with coarse pitch.Comparative experiments show burr,aperture inconsistency and error are typical interface defects.Meanwhile,aperture inconsistency and error are more serious than burr in NCOM with coarse pitch.As one of the major causes of interface defects,axial force and radial force are intensively studied.Based upon the machining principle of orbital milling(OM)and the actual hole-making condition in laminated structures,NCOM experiments with coarse pitch are conducted on CFRP/Ti6Al4V laminates under different cutting conditions.Then,the effects of interlayer clamping,minimal quantity lubrication(MQL),twice milling instead of reaming,and interlayer speed change on interface aperture are analyzed.Research shows that interlayer clamping,interlayer speed change and MQL can effectively reduce out-of-tolerance of interface aperture.When making holes of different diameters with one cutter,axial feed has a greater effect on interface aperture precision than tangential feed.When making holes of the same diameter with different cutters,small diameter cutter will reduce interface aperture precision in a single processing.But the method of“twice milling instead of reaming”can improve the aperture precision effectively.展开更多
How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Mot...How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.展开更多
Based on the principles of differential geometry,the basic equations are derived for generating gouging free tool path in 5-axis NC face milling,the influence of surface's local geometry is discussed,and the condi...Based on the principles of differential geometry,the basic equations are derived for generating gouging free tool path in 5-axis NC face milling,the influence of surface's local geometry is discussed,and the conditions of using cutter with reasonable diameter are presented.展开更多
Presents the division of non developable ruled surface into divided small areas and flank milling in these divided areas to improve machining efficiency and machined surface quality by controlling the machining error ...Presents the division of non developable ruled surface into divided small areas and flank milling in these divided areas to improve machining efficiency and machined surface quality by controlling the machining error for each area, and the algorithms developed for generation of tool path and calculation of errors, and concludes from computer simulation results that the algorithms are correct.展开更多
文摘Machining-features of the workplace are described by using of the object-oriented （O-O） technology. Geometrical machining-features are recognized in the given cut region by using the maximum membership priciple about the fuzzy set. Depending on the IF-THEN rule and the fuzzy matching method, the rough information of the machining-process for high-speed milling （HSM） is extracted based on the database of machining-process for HSM. The optimization model of machining-process scheme is established to obtain shorter cut time, lower cost or higher surface quality. It is helpful to form successful cases for HSM. NC programming for HSM is realized according to optimized machining-process data from HSM cases selected by the optimization model and the extracted information of machining-process.
文摘Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC vertical milling machine. A unique method is used for simulating the cutting process and displaying the three dimensional images. This method not only simplifies greatly the treatment of the hidden line but also creates a “photograph effect” image. The program is written in Visual B.
基金Supported by the National Natural Science Foundation of China(No.51575143)
文摘Tool path generated by space-filling curve always turns frequently causing trembling to machine,reducing toollife and affecting workpiece quality. Length and generation time of tool paths are both relatively long. In order to solve these problems,a toolpath generation method of NC milling based on space-filling curve is proposed. First,T-spline surface is regarded as the modeling surface,the grid,which is based on the limited scallop-height,can be got in the parameter space,and the influence value of grid node is determined. Second,a box is defined and planned,and the tool paths are got preliminarily,which is based on minimal spanning tree; Finally,based on an improved chamfering algorithm,the whole tool paths are got. A simulation system is developed for computer simulation,and an experiment is carried out to verify the method. The results of simulation and experiment show that the method is effective and feasible,and length and time of the tool paths are reduced.
基金Natural Science Research in Jiangsu Province(No.17KJB460008)the 333 Project Research Funding Project in Jiangsu Province(No.BRA2018310)the Innovation Project of Jiangsu Province.
文摘The methods for reducing interface aperture inconsistency are studied in NC orbital milling(NCOM)of CFRP/Ti6Al4V laminates with coarse pitch.Comparative experiments show burr,aperture inconsistency and error are typical interface defects.Meanwhile,aperture inconsistency and error are more serious than burr in NCOM with coarse pitch.As one of the major causes of interface defects,axial force and radial force are intensively studied.Based upon the machining principle of orbital milling(OM)and the actual hole-making condition in laminated structures,NCOM experiments with coarse pitch are conducted on CFRP/Ti6Al4V laminates under different cutting conditions.Then,the effects of interlayer clamping,minimal quantity lubrication(MQL),twice milling instead of reaming,and interlayer speed change on interface aperture are analyzed.Research shows that interlayer clamping,interlayer speed change and MQL can effectively reduce out-of-tolerance of interface aperture.When making holes of different diameters with one cutter,axial feed has a greater effect on interface aperture precision than tangential feed.When making holes of the same diameter with different cutters,small diameter cutter will reduce interface aperture precision in a single processing.But the method of“twice milling instead of reaming”can improve the aperture precision effectively.
文摘How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.
文摘Based on the principles of differential geometry,the basic equations are derived for generating gouging free tool path in 5-axis NC face milling,the influence of surface's local geometry is discussed,and the conditions of using cutter with reasonable diameter are presented.
文摘Presents the division of non developable ruled surface into divided small areas and flank milling in these divided areas to improve machining efficiency and machined surface quality by controlling the machining error for each area, and the algorithms developed for generation of tool path and calculation of errors, and concludes from computer simulation results that the algorithms are correct.
