Wiper tools are revered for their capacity to simultaneously achieve high-quality and high-efficient machining.Nonetheless,the cutting mechanism of wiper tools remains unclear,and the cutting force prediction model of...Wiper tools are revered for their capacity to simultaneously achieve high-quality and high-efficient machining.Nonetheless,the cutting mechanism of wiper tools remains unclear,and the cutting force prediction model of wiper tools has not been reported,leading to severe wear of the bottom wiper edge and unstable cutting in machining processes.In this study,the cutting mechanism of wiper tools is systematically analyzed,and the mechanistic cutting force model considering the wiper edge cutting effect was established.The cutting force coefficients were calibrated by the cutting force separation method,which can quickly calibrate the cutting force coefficients for the flank cutting region dominated by the shear effect,the bottom cutting region dominated by the shear effect,and the bottom wiper region dominated by plough effect.Compared with measured cutting forces,the maximum average absolute errors in the predicted forces are 9.2%,7.6%,and 9.3%in the x,y,and z directions,respectively.Furthermore,the feed rate and the length of the wiper edge were primary determinants of the bottom-edge cutting forces.This study provides theoretical guidance and technical support for the wear mechanism and design of wiper tools.展开更多
The equipment used in various fields contains an increasing number of parts with curved surfaces of increasing size.Five-axis computer numerical control(CNC)milling is the main parts machining method,while dynamics an...The equipment used in various fields contains an increasing number of parts with curved surfaces of increasing size.Five-axis computer numerical control(CNC)milling is the main parts machining method,while dynamics analysis has always been a research hotspot.The cutting conditions determined by the cutter axis,tool path,and workpiece geometry are complex and changeable,which has made dynamics research a major challenge.For this reason,this paper introduces the innovative idea of applying dimension reduction and mapping to the five-axis machining of curved surfaces,and proposes an efficient dynamics analysis model.To simplify the research object,the cutter position points along the tool path were discretized into inclined plane five-axis machining.The cutter dip angle and feed deflection angle were used to define the spatial position relationship in five-axis machining.These were then taken as the new base variables to construct an abstract two-dimensional space and establish the mapping relationship between the cutter position point and space point sets to further simplify the dimensions of the research object.Based on the in-cut cutting edge solved by the space limitation method,the dynamics of the inclined plane five-axis machining unit were studied,and the results were uniformly stored in the abstract space to produce a database.Finally,the prediction of the milling force and vibration state along the tool path became a data extraction process that significantly improved efficiency.Two experiments were also conducted which proved the accuracy and efficiency of the proposed dynamics analysis model.This study has great potential for the online synchronization of intelligent machining of large surfaces.展开更多
When ultrasonically cutting honeycomb core curved parts,the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface.How...When ultrasonically cutting honeycomb core curved parts,the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface.However,given that the straight blade is a nonstandard tool,the existing computer-aided manufacturing technology cannot directly realize the above action requirement.To solve this problem,this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file,which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade.At the same time,for the multi-solution problem of the rotation axis,the dependent axis rotation minimization algorithm was introduced,and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part.Finally,on the basis of the MATLAB platform,the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled,and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed.The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software,and the simulation machining of the equivalent entity of the honeycomb core can then be realized.The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features.Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition,and the workpieces obtained by machining also meet the corresponding accuracy requirements.Therefore,the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.展开更多
基金Supported by National Key Research and Development Program of China(Grant No.2018YFA0702900)National Natural Science Foundation of China(Grant Nos.52075076,U1908231)。
文摘Wiper tools are revered for their capacity to simultaneously achieve high-quality and high-efficient machining.Nonetheless,the cutting mechanism of wiper tools remains unclear,and the cutting force prediction model of wiper tools has not been reported,leading to severe wear of the bottom wiper edge and unstable cutting in machining processes.In this study,the cutting mechanism of wiper tools is systematically analyzed,and the mechanistic cutting force model considering the wiper edge cutting effect was established.The cutting force coefficients were calibrated by the cutting force separation method,which can quickly calibrate the cutting force coefficients for the flank cutting region dominated by the shear effect,the bottom cutting region dominated by the shear effect,and the bottom wiper region dominated by plough effect.Compared with measured cutting forces,the maximum average absolute errors in the predicted forces are 9.2%,7.6%,and 9.3%in the x,y,and z directions,respectively.Furthermore,the feed rate and the length of the wiper edge were primary determinants of the bottom-edge cutting forces.This study provides theoretical guidance and technical support for the wear mechanism and design of wiper tools.
基金Supported by National Natural Science Foundation of China(Grant Nos.52005078,U1908231,52075076).
文摘The equipment used in various fields contains an increasing number of parts with curved surfaces of increasing size.Five-axis computer numerical control(CNC)milling is the main parts machining method,while dynamics analysis has always been a research hotspot.The cutting conditions determined by the cutter axis,tool path,and workpiece geometry are complex and changeable,which has made dynamics research a major challenge.For this reason,this paper introduces the innovative idea of applying dimension reduction and mapping to the five-axis machining of curved surfaces,and proposes an efficient dynamics analysis model.To simplify the research object,the cutter position points along the tool path were discretized into inclined plane five-axis machining.The cutter dip angle and feed deflection angle were used to define the spatial position relationship in five-axis machining.These were then taken as the new base variables to construct an abstract two-dimensional space and establish the mapping relationship between the cutter position point and space point sets to further simplify the dimensions of the research object.Based on the in-cut cutting edge solved by the space limitation method,the dynamics of the inclined plane five-axis machining unit were studied,and the results were uniformly stored in the abstract space to produce a database.Finally,the prediction of the milling force and vibration state along the tool path became a data extraction process that significantly improved efficiency.Two experiments were also conducted which proved the accuracy and efficiency of the proposed dynamics analysis model.This study has great potential for the online synchronization of intelligent machining of large surfaces.
基金support from the National Natural Science Foundation of China (Grant No.U20A20291).
文摘When ultrasonically cutting honeycomb core curved parts,the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface.However,given that the straight blade is a nonstandard tool,the existing computer-aided manufacturing technology cannot directly realize the above action requirement.To solve this problem,this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file,which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade.At the same time,for the multi-solution problem of the rotation axis,the dependent axis rotation minimization algorithm was introduced,and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part.Finally,on the basis of the MATLAB platform,the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled,and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed.The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software,and the simulation machining of the equivalent entity of the honeycomb core can then be realized.The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features.Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition,and the workpieces obtained by machining also meet the corresponding accuracy requirements.Therefore,the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.
