Ball-end mill is widely used in workpiece processi ng with free-form surfaces. Such models that can predict processing character istics precisely are very necessary to the aim of cost reducing, quality improvi ng and ...Ball-end mill is widely used in workpiece processi ng with free-form surfaces. Such models that can predict processing character istics precisely are very necessary to the aim of cost reducing, quality improvi ng and productivity progressing, the cutting force prediction is the most import ant among these models. To explore the physical essence of metal cutting, model researchers commonly simplify the geometric conditions in cutting process, and a ssume that the geometric parameters that are needed to solve the physical models have already been predefined, so it results in the separation between model res earch and practical application. In this paper, for the representative cutting f orce models of ball end milling, a new extraction method of geometric parameters is suggested, which makes it possible for physical model to actually serve for the practical manufacturing, and take in the inspection of real production.展开更多
Many small-size precise plastic helical involutes gears are used in electrical appliances to transmit rotary movements con- tinuously and smoothly. Ball-end milling is an effective method for trial manufacture or smal...Many small-size precise plastic helical involutes gears are used in electrical appliances to transmit rotary movements con- tinuously and smoothly. Ball-end milling is an effective method for trial manufacture or small batch production of this type of gear, but the precision of the gear is usually low. In this research, the main sources of the errors of the gear, machining errors of the tooth profile and trace of the gear obtained were analyzed. The correction amounts for these errors are then determined by using a CNC gear tester. They are used to generate a new 3D-CAD model for gear machining with better nrecision.展开更多
Five-axis ball-end milling is commonly used to machine the complex surfaces. Local tool interference phenomenon which often occurs in five-axis milling should be urgently solved. In this paper, a simplified method to ...Five-axis ball-end milling is commonly used to machine the complex surfaces. Local tool interference phenomenon which often occurs in five-axis milling should be urgently solved. In this paper, a simplified method to detect the occurrence of local tool interference and modify tool position is proposed. First, the detection matrix is established to detect local tool interference at all the cutter location points on tool path simultaneously in five-axis ball-end milling of complex surfaces. The algorithm of detection matrix based on point arithmetic is simple. Secondly, the new coordinates of the modified interfering-free points are obtained precisely by using the genetic algorithm. The feasibility of the method is validated by simulation in Matlab. This research is benefit to simplify the calculation of local tool interference detection and tool position modification.展开更多
Machining of carbon/carbon （C/C） composite materials is difficult to carry out due to its high specific stiffness, brittleness, anisotropic, non-homogeneous and low thermal conductivity, which can result in tear, bu...Machining of carbon/carbon （C/C） composite materials is difficult to carry out due to its high specific stiffness, brittleness, anisotropic, non-homogeneous and low thermal conductivity, which can result in tear, burr, poor surface quality and rapid wear of cutters. Accurate and fast pre- diction of cutting forces is important for milling C/C composite materials with high quality. This paper presents an alternative cutting force model involving the influences of the directions of fiber. Based on the calculated and experimental results, the cutting forces＂ coefficients of 2.5D CC com- posites are evaluated using multiple linear regression method. Verification experiment has been car- ried out through a group of orthogonal tests. Results indicate that the proposed nmdel is reliable and can be used to predict the cutting forces in ball-end milling of 2.5D C/C composites.展开更多
Titanium alloy has been applied in the field of aerospace manufacturing for its high specific strength and hardness.Nonetheless,these properties also cause general problems in the machining,such as processing ineffici...Titanium alloy has been applied in the field of aerospace manufacturing for its high specific strength and hardness.Nonetheless,these properties also cause general problems in the machining,such as processing inefficiency,serious wear,poor workpiece face quality,etc.Aiming at the above problems,this paper carried out a comparative experimental study on titanium alloy milling based on the CAMCand BEMC.The variation law of cutting force and wear morphology of the two tools were obtained,and the wear mechanism and the effect of wear on machining quality were analyzed.The conclusion is that in contrast with BEMC,under the action of cutting thickness thinning mechanism,the force of CAMC was less,and its fluctuation was more stable.The flank wear was uniform and near the cutting edge,and the wear rate was slower.In the early period,the wear mechanism of CAMC was mainly adhesion.Gradually,oxidative wear also occurred with milling.Furthermore,the surface residual height of CAMC was lower.There is no obvious peak and trough accompanied by fewer surface defects.展开更多
文摘Ball-end mill is widely used in workpiece processi ng with free-form surfaces. Such models that can predict processing character istics precisely are very necessary to the aim of cost reducing, quality improvi ng and productivity progressing, the cutting force prediction is the most import ant among these models. To explore the physical essence of metal cutting, model researchers commonly simplify the geometric conditions in cutting process, and a ssume that the geometric parameters that are needed to solve the physical models have already been predefined, so it results in the separation between model res earch and practical application. In this paper, for the representative cutting f orce models of ball end milling, a new extraction method of geometric parameters is suggested, which makes it possible for physical model to actually serve for the practical manufacturing, and take in the inspection of real production.
文摘Many small-size precise plastic helical involutes gears are used in electrical appliances to transmit rotary movements con- tinuously and smoothly. Ball-end milling is an effective method for trial manufacture or small batch production of this type of gear, but the precision of the gear is usually low. In this research, the main sources of the errors of the gear, machining errors of the tooth profile and trace of the gear obtained were analyzed. The correction amounts for these errors are then determined by using a CNC gear tester. They are used to generate a new 3D-CAD model for gear machining with better nrecision.
基金Funded by the National Natural Science Foundation of China (No.51575321)the Major Science and Technology Innovation Project of Shandong Province (No.2018CXGC0804)Taishan Scholars Program of Shandong Province (No.ts201712002)
文摘Five-axis ball-end milling is commonly used to machine the complex surfaces. Local tool interference phenomenon which often occurs in five-axis milling should be urgently solved. In this paper, a simplified method to detect the occurrence of local tool interference and modify tool position is proposed. First, the detection matrix is established to detect local tool interference at all the cutter location points on tool path simultaneously in five-axis ball-end milling of complex surfaces. The algorithm of detection matrix based on point arithmetic is simple. Secondly, the new coordinates of the modified interfering-free points are obtained precisely by using the genetic algorithm. The feasibility of the method is validated by simulation in Matlab. This research is benefit to simplify the calculation of local tool interference detection and tool position modification.
基金supported by the National Natural Science Foundation of China(No.51105312)the Fundamental Research Funds for the Central University of China(No.3102015JCS05005)
文摘Machining of carbon/carbon （C/C） composite materials is difficult to carry out due to its high specific stiffness, brittleness, anisotropic, non-homogeneous and low thermal conductivity, which can result in tear, burr, poor surface quality and rapid wear of cutters. Accurate and fast pre- diction of cutting forces is important for milling C/C composite materials with high quality. This paper presents an alternative cutting force model involving the influences of the directions of fiber. Based on the calculated and experimental results, the cutting forces＂ coefficients of 2.5D CC com- posites are evaluated using multiple linear regression method. Verification experiment has been car- ried out through a group of orthogonal tests. Results indicate that the proposed nmdel is reliable and can be used to predict the cutting forces in ball-end milling of 2.5D C/C composites.
基金Supported by National Natural Science Foundation of China(Grant No.51975168).
文摘Titanium alloy has been applied in the field of aerospace manufacturing for its high specific strength and hardness.Nonetheless,these properties also cause general problems in the machining,such as processing inefficiency,serious wear,poor workpiece face quality,etc.Aiming at the above problems,this paper carried out a comparative experimental study on titanium alloy milling based on the CAMCand BEMC.The variation law of cutting force and wear morphology of the two tools were obtained,and the wear mechanism and the effect of wear on machining quality were analyzed.The conclusion is that in contrast with BEMC,under the action of cutting thickness thinning mechanism,the force of CAMC was less,and its fluctuation was more stable.The flank wear was uniform and near the cutting edge,and the wear rate was slower.In the early period,the wear mechanism of CAMC was mainly adhesion.Gradually,oxidative wear also occurred with milling.Furthermore,the surface residual height of CAMC was lower.There is no obvious peak and trough accompanied by fewer surface defects.
