共查询到20条相似文献,搜索用时 31 毫秒
1.
轮廓周边倒圆角、铣削斜面一般使用球头刀或者平底立铣刀,并编制宏程序完成铣削加工。将SIEMENS系统的T铣削;倒圆;倒角;编程;$TC_DP;R参数 轮廓周边倒圆角、铣削斜面一般使用球头刀或者平底立铣刀,并编制宏程序完成铣削加工。将SIEMENS系统的T$_DP功能和R参数有机地结合起来,分析其程序的编制方法,推导得出了刀具半径补偿值的计算公式,编制了通用的加工宏程序。 相似文献
2.
渐开线齿轮齿根过渡曲线是影响齿根弯曲应力的重要因素.为提高齿轮的弯曲强度,提出了采用椭圆曲线代替延伸渐开线的等距曲线,基于坐标转换原理,求出椭圆曲线方程.并采用30°切线法求出椭圆过渡曲线齿形系数和应力集中系数,与标准刀具加工的齿根曲线进行比较,结果表明采用椭圆过渡曲线可以使弯曲应力降低15%.根据齿形法线法,反求出获得该椭圆曲线的滚刀刀顶曲线,为滚刀刀顶设计和实际加工提供了理论依据. 相似文献
3.
4.
In a given size of symmetric involute gear designed through conventional approach, as the load carrying capacity is restricted at the higher pressure angle due to tipping formation, the use of the asymmetric toothed gear to improve the fillet capacity in bending is examined in this study. Non-standard asymmetric rack cutters with required pressure angles and module are developed to generate the required pinion and gear of a drive with asymmetric involute surfaces and trochoidal fillet profiles. The respective profiles thus generated are optimized for balanced fillet stresses that are equal and possibly the lowest also. For this study of optimization, several non-standard asymmetric rack cutters are designed to accommodate different combinations in the values of pressure angle, top land thickness ratio, profile shift, speed ratio and the asymmetric factors. However for any drive with a given center distance and a speed ratio, only two non-standard asymmetric rack cutters, one for the pinion and other for the gear are used to generate a required numbers of pinion and gear with different cutter shift values for the purpose of optimization. The influence of these parameters on the maximum fillet stress has been analyzed to suggest the optimum values of these parameters that improve the fillet capacity in bending. The optimization of the asymmetric spur gear drive is carried out using an iterative procedure on the calculated maximum fillet stresses through FEM for different rack cutter shifts and finally the optimum values of rack cutter shifts are suggested for the given center distance and the speed ratio of an asymmetric gear drive. Comparisons have also been made successfully with the results of the AGMA and the ISO codes for symmetric gears to justify the results of the finite element method pertaining to this study. 相似文献
5.
6.
变位系数计算是插齿刀设计的重要工作。文章讨论了插齿刀变位系数选取原则以及应当满足不产生齿顶变尖、被切齿轮齿根过渡曲线干涉、根切和顶切等四个约束条件,给出了新刀设计的最大变位系数和根据刃磨到最后刀齿仍有必要强度所允许的最小变位系数计算公式,编制了插齿刀变位系数计算机辅助运算流程,使插齿刀设计简单快速且便于判断设计的可行性。 相似文献
7.
8.
Adaptable geometric patterns for five-axis machining: a survey 总被引:4,自引:3,他引:1
Stanislav S. Makhanov 《The International Journal of Advanced Manufacturing Technology》2010,47(9-12):1167-1208
The paper presents a survey of five-axis computer numerical controlled (CNC) machining optimization methods employing adaptable geometric patterns. First, the survey introduces evolution of CNC interpolators from the simplest Taylor series-based routines to sophisticated procedures based on constraint minimization from dynamic systems control theory. Furthermore, a variety of methods based on spline interpolation, NURBS interpolation and Farouki’s Pythagorean–hodograph curves is presented and analyzed. Next, the survey deals with techniques to optimize the positions and orientations of the tool in a particular neighborhood of the part surface. The most important application of these techniques is cutting by a flat-end or a fillet mill while avoiding local overcuts or undercuts due to the curvature interference and rear gouging. This section is supplemented by detection of global interference using visibility cone schemes and their recent modifications and improvements. Solutions offered by solid modeling are presented as well. Finally, adaptable geometric patterns employed for tool path generation are considered and analyzed. The adaptation is performed using certain criteria of the tool path quality, such as kinematics error, scallops, possible undercuts or overcuts, and the continuity of the path. Also covered are complex pocket milling employing geometric patterns capable of following the boundary, such as the offset methods, regional milling, the potential path methods, and clustering. The chapter also presents tool path optimization based on the adaptable curvilinear grids connecting the cutter location points. Finally, navigation approaches and the shortest-path schemes are considered, along with the adaptive space-filling curve algorithms and their combinations with grid generation. 相似文献
9.
A. Senthil kumar F. K. Salim Professor A. Y. C. Nee 《The International Journal of Advanced Manufacturing Technology》1996,11(2):136-145
Prismatic parts usually comprise basic features, such as slots, steps, holes, bosses, which may intersect with one another. In general, automatic recognition of intersecting features is difficult and may present bottlenecks when automating the design procedures which make use of features for downstream operations.This paper presents a novel approach to recognising intersecting features and auxiliary features due to tool movements and cutter radii. Since no cutting edges can be perfectly sharp, corner fillets on machined features are invariably created by end mills and other cutters. Fillets, on the other hand, could very well be features which have been designed to increase strength and reduce stress concentration of certain features. A feature recognition system is proposed to recognise features having fillets which may be either design or manufacturing features. This information will be useful to the product designer as it would be possible to distinguish between the intended and unintended features of a part. The developed system has been implemented on an HP-ME30 Solid Modeler. 相似文献
10.
11.
以广州数控系统980T为例,阐述了数控车床中刀补的建立及其应用.在数控机床上使用多把丰刀加工工件时,除了基准刀外,其他的几把刀具一般都要设置刀具补偿.刀补设置的正确与否,不但影响到工件的加工精度,还对其他方面诸如加工生产率等产生影响.正确并巧妙地设置刀具补偿,不但有效保证工件的加工精度,还可以简化加工编程,提高生产率. 相似文献
12.
F. Y. Han D. H. Zhang M. Luo B. H. Wu 《The International Journal of Advanced Manufacturing Technology》2014,71(9-12):1801-1810
Plunge milling is the most effective way for rough machining of impeller parts, but previous research had not considered the optimization of plunge cutter selection and tool path. In this paper, a new method for optimizing the plunge cutter selection and tool path generation in multi-axis plunge milling of free-form surface impeller channel is proposed in order to improve the efficiency in rough machining. Firstly, in the case of fixing a rotation axis at a certain angle in five-axis machine, a mathematical representation is formulated for the geometric model of the cutter interfering the impeller, and an optimization model of the cutter size is established at a cutter contact point on the impeller channel surface, so the largest tool could be determined. Secondly, by analyzing the machine tool movement characteristics, the geometric constraint model of the plunge tool path which relative to the largest tool, step distance, and row space is established, and a tool orientation calculation method of impeller channel machining is given, and then, the plunge tool path and tool orientation could be obtained. Finally, the generated tool path and tool orientation are simulated and verified in practical processing. Simulation and experimental result shows that the rough machining efficiency of the impeller part is improved up to 40 % with this method. 相似文献
13.
Aqeel Ahmed Zezhong C. Chen 《The International Journal of Advanced Manufacturing Technology》2017,90(5-8):1235-1252
Interference detection and avoidance by the shortest cutter for the five-axis milling machining is a critical task. Short tool length increases the rigidity and chatter stability of the cutter. In this research, a new and efficient method of interference detection and avoidance by the shortest cutter is developed. For the specific five-axis machine configuration, first possible candidate parts for the collision are found, which are complete cutting system (spindle, tool holder, and cutter), the work in process model, and the fixture. Spindle, tool holder, and tool are represented by the solid geometry identity of the cylinder, truncated cone, and cylinder, respectively, with the length and diameter as parameters. The surfaces of the work in process model and the fixture model are represented as the point cloud data of the suitable density. The Kd-tree data structure is employed on point cloud data which gives an efficient searching of the potential candidate points for the interference detection with the complete cutting system. All existing methods are able to detect the collision, but they are not capable to remove it with the optimum cutter length. The proposed algorithm has not only the capability of collision detection; it can also remove the collision with the optimum tool length. Other scope of the proposed algorithm is the selection of the tool holder to minimize the overhang tool length. 相似文献
14.
Wei Li Beizhi Li Jianguo Yang 《The International Journal of Advanced Manufacturing Technology》2017,91(9-12):3135-3143
The influences of tool setting errors on skiving accuracy are discussed in this paper. Firstly, a method for the calculation of error-free cutting edge of skiving cutter is proposed. Based on the theories of cutter enveloping gear, the gear profile deviations, which are affected by the tool position and orientation errors in skiving, are analyzed. Results show that the profile deviations are insensitive to this kind of setting error of the cutter. Then, the effects of tool eccentricity error on skiving accuracy are analyzed. Results show that the waves on the tooth flanks, which are caused by the tool eccentricity error, have obvious influences on the helix deviations and the profile deviations of the workpiece. The waves on the tooth flanks are periodic ones and can be obviously affected by the number of teeth of the cutter. 相似文献
15.
球头铣刀刀具磨损建模与误差补偿 总被引:3,自引:0,他引:3
针对刀具磨损度量方式和模型建立的问题,以球头刀具为研究对象,提出球头铣刀刀具磨损的度量方式,建立球头刀具磨损模型.以复映磨损在硬度较软加工材料上的方式测量球头刀具磨损,确定刀具磨损模型系数,给出刀具磨损模型系数确定的具体实现方法.加工试验验证球头刀具磨损度量方式的合理性和所建立刀具磨损模型的正确性,同时针对数控铣削加工中球头铣刀刀具磨损引起的误差提出离线仿真误差补偿算法,给出离线仿真误差补偿算法的具体实现步骤,通过建立的刀具磨损引起的加工误差模型仿真获得加工走刀步的误差.对于误差超差的走刀步,预先修改数控加工(Numerical control,NC)程序,保证实际加工零件满足精度要求.误差补偿验证试验表明所提出的离线仿真误差补偿算法的正确性和有效性. 相似文献
16.
A theoretical cutting force model for helical end milling with cutter runout is developed using a predictive machining theory, which predicts cutting forces from the input data of workpiece material properties, tool geometry and cutting conditions. In the model, a helical end milling cutter is discretized into a number of slices along the cutter axis to account for the helix angle effect. The cutting action for a tooth segment in the first slice is modelled as oblique cutting with end cutting edge effect and tool nose radius effect, whereas the cutting actions of other slices are modelled as oblique cutting without end cutting edge effect and tool nose radius effect. The influence of cutter runout on chip load is considered based on the true tooth trajectories. The total cutting force is the sum of the forces at all the cutting slices of the cutter. The model is verified with experimental milling tests. 相似文献
17.
Y. S. Tarng Y. W. Hseih S. T. Hwang 《The International Journal of Advanced Manufacturing Technology》1994,9(3):141-146
A new intelligent sensor system using neural networks to separate tool breakage clearly from the cutter run-out or cutting transients in milling is proposed. The features of the spindle displacement signal are fed into the input layer of the neural network. With the back propagation training algorithm, the output of the neural network can be used to identify the milling cutter with or without tool breakage. Experiments show that this new approach can monitor tool breakage in milling operations successfully. 相似文献
18.
为了提高三角网格曲面五轴加工的加工效率,提出了基于最大材料去除率(maximal materialremoval rate,MMR)的平底刀五轴加工刀轨生成算法。首先计算无曲率干涉且具有最大材料去除率的网格曲面五轴加工的刀具方位角;然后在确定网格曲面可能干涉区域的基础上,提出刀触点处干涉性假设,并以最大材料去除率、刀具无曲率干涉和全局干涉为约束条件,采用二分法确定具有最大材料去除率的无干涉刀具方位角;最后采用截面线法生成三角网格曲面MMR平底刀五轴加工刀轨。通过实验验证了采用文中算法生成的刀轨进行加工能够获得较高的加工效率和表面质量。 相似文献
19.
提出了一种分段产生共轭齿廓的方法,此方法是用三次曲线函数来描述刀具方程,然后根据啮合方程求出共轭的齿廓方程.与传统方法不一样的是,它是分段产生共轭齿廓的,是一种离散的方法,此方法的前提是要求出刀具上的一系列点,通过这些点的坐标来确定三次曲线函数.刀具上点的获得有两种方法:一是从刀具方程中直接获得,二是用坐标测量机械来测出刀具上的点.此方法还可以用于检验刀具使用一段时间后所产生的齿廓,通过与原始加工齿廓的比较来判断刀具的磨损程度. 相似文献
20.
刀具在加工过程中的变形和振动直接关系到加工精度,是衡量刀具的重要性能指标。本文针对木材用高速螺旋式玉米铣刀,采用有限元分析的方法,对其进行了切削过程的变形分析和振动变形分析,根据分析结果所发现的不足,提出了将刀具体内壁加厚后成台阶状和将配重拉杆截断后加粗的优化方案。研究结果表明:优化后的刀具在加工中的变形由原来的2.2-3.7μm降低到1.8-2.5μm,降低了因刀具设计而导致的加工精度误差;刀具共振频率由262Hz左右增加到1000Hz以上,避免了低频激振;刀具拉杆的共振变形由原来的1.5-2.0m降低到0.22-0.24m,提高了刀具整体刚性。本文的分析与优化工作为木材用玉米铣刀的设计与样板试验提供了重要的技术数据。 相似文献