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利用MasterCAM软件加工变导程螺纹的关键在于绘制变导程螺纹螺旋线的展开图。从运动学的角度对变导程螺旋线及其展开图进行了分析和研究,导出了变导程螺旋线及其展开线的方程,提出了绘制变导程螺旋线展开图的方法,并给出了数控加工的实例。 相似文献
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针对过渡曲面加工表面质量往往比普通曲面更难控制的特殊性,开展与过渡面适应的速度规划、加工轨迹的局部优化等研究来改善过渡面的表面质量,并通过运动参数可视化来预测过渡面的加工质量。在一定变化范围内,使空间曲率、挠率具有连续性的连续程序段属于一个区间,以建立过渡面的刀具轨迹“同速区间”。在同速区间内建立弧长参数化、拟合递推式Akima样条曲线,实现刀具轨迹的局部优化。通过数控模拟软件采集运动参数(速度、加速度及电流等),生成的插补文件导入自主开发的运动参数可视化软件,形成可视化图以此来预估加工表面质量。分别对可乐瓶底与变曲率曲面的过渡面进行同速区间规划与轨迹优化,得到了优化前后的可视化图。进一步,验证预估表面质量的有效性,通过对变曲率过渡面和五指山零件实际加工,验证了加工表面质量提高与否与可视化图好坏的一致性。因此建立过渡面同速区间及运动参数可视化,以实现过渡面的质量预估及提升效果。 相似文献
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<正> 凸轮加工方法中,按切削运动原理可分为成形加工法和包络线加工法。包络线加工法是盘形凸轮的主要加工方法,在实际加工的凸轮轮廓曲线中,大多数是平面螺旋线。这种平面螺旋线,以渐开线平面螺旋线和阿基米德螺旋线为主。平面螺旋线的加工常选用垂直铣削法,即以刀具的包络线作出平面螺旋线,这样就造成了实际包络线与理论平面螺旋线的误差。对这种误差的分析计算是决定凸轮加工方法的前提。 相似文献
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滚齿加工的齿轮齿根过渡曲线 总被引:1,自引:0,他引:1
对滚齿加工出的斜齿轮的端面内齿根过渡曲线的形状和曲线方程进行了研究,指出滚刀齿顶圆弧在齿轮端截面内的廓形已变为椭圆弧,在斜齿轮端截面内刀顶对应部分形成的齿根过渡曲线不能用圆弧代替计算,否则将严重影响齿根过渡曲线描绘的准确度,进而影响到在此基础上的齿根强度、加工干涉性、刀具设计、三维造型等一系列分析、研究工作的结论正确性。重点研究分析了滚刀齿顶端截面椭圆弧方程以及对应形成的齿轮端截面内齿根过渡曲线方程的推导和建立,并将研究成果应用于自编的齿轮加工验算软件予以应用和验证。 相似文献
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利用MasterCAM软件加工变导程螺纹的关键在于绘制变导程螺纹螺旋线的展开图.从运动学的角度对变导程螺旋线及其展开图进行了分析和研究,导出了变导程螺旋线及其展开线的方程,提出了绘制变导程螺旋线展开图的方法,并给出了数控加工的实例. 相似文献
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往复加工常见于磨削和刨削等金属切削中,加工过程的平稳性直接影响到产品的加工质量、能源效率乃至机床的寿命。首先探究往复(冲程)运动速度规划对运动过程平稳性的影响,在分析了常见速度规划运动学性能的基础上,针对磨削冲程运动的特点,提出通过改变急动度空间分布来降低柔性冲击对加工表面质量的影响,并设计了两种基于急动度连续的速度规划算法。在此基础上,研究了速度规划算法和磨削力平稳性、加工表面粗糙度和加工能耗间的关系,提出了通过改变加速度空间分布来降低加工能耗的方法。试验结果表明,往复运动速度规划和磨削力平稳性、加工表面粗糙度以及加工能耗均相关,通过改变急动度和加速度空间分布提高了磨削力平稳性和加工表面质量,降低了加工能耗。所提出的Ⅱ型速度规划综合表现优于其他规划,与梯形速度规划相比,切削力波动、加工表面粗糙度和电机驱动能耗均有较为显著的下降。 相似文献
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三次多项式型微段高速加工速度规划算法研究 总被引:4,自引:1,他引:3
为满足高速数控加工的要求,提出了一种三次多项式加减速控制模型.该模型能保证高速运行过程中加速度的连续,使机床运行平稳,避免产生大的冲击.针对连续微段的高速加工,建立了满足最大速度、最大加速度、几何运动轨迹及长度约束条件下的轨迹速度规划策略,并给出三次多项式型速度规划算法的实现流程图.试验结果表明,该算法能实现连续微段间进给速度的高速衔接,大大缩短加工时间并提高加工效率.该算法已成功应用于多坐标数控高速微细加工系统中. 相似文献
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Yuyao Li Jingchun Feng Yuhan Wang Jianguo Yang 《The International Journal of Advanced Manufacturing Technology》2009,40(7-8):769-775
To alleviate the feed fluctuation and to maintain a smooth feed in conventional five-axis machining, an optimal feed interpolation algorithm (look-ahead) is proposed. However, the problem arises where the segment usually cannot be interpolated exactly in an integer period because of the nonzero joint feed at the junction. To overcome this problem, and to achieve faster machining speed and higher quality parts, this paper presents an optimal feed interpolation algorithm for high-speed, five-axis machining having the function of “look-ahead”, i.e., variable-period linear interpolation algorithm. In real applications, the proposed algorithm results in: (1) constant speed; (2) high machining accuracy. Moreover, in this paper, an efficient method for acceleration and deceleration control is presented to achieve the highest-quality feed profiles and to shorten machining times. The precision and speed of machining is improved greatly. Experimental results verify the effectiveness of the proposed method. 相似文献
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Moncef Hbaieb Radhouane Othmani Wassila Bouzid 《The International Journal of Advanced Manufacturing Technology》2011,53(1-4):113-120
Numerical control milling (NCM) at high speed is the most used machining process in the manufacture of molds because it offers high productivity and workpiece surface quality. The aim of this work is to establish a methodology to evaluate the rough machining time, during high speed milling. In pocket machining, a 2.5D milling has been considered. The proposed approach considers the roughing cutting time as the ratio of the pocket volume by the removed material rate. The pocket is divided into volumes distributed according to the real radial depth. Since the radial depth varies during machining, the removed material rate is not constant. In this paper, an experimental study is carried out to validate models of machining time calculation. The obtained results show that the proposed method offers fast and easy calculation of the machining time of pocket roughing. 相似文献
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高速数控加工速度的自适应控制 总被引:8,自引:1,他引:7
为了满足高速加工的要求,提出了一种基于最小冲击的多程序段运动速度控制自适应算法。该算法根据两相邻的运动矢量之夹角和两程序段运动的速度,计算出拐角处冲击的大小,并根据对机床产生最小冲击原理,计算出拐角处的速度值,实现进给速度提前自适应地减速,从而防止刀具在拐角处发生过载,并有效地减少了工件形状在拐角处,或小半径圆弧处的伺服跟踪误差;在高速加工时获得了高的加工精度与良好的表面光洁度。该算法简单、有效,已在最新开发的高速铣床上得到应用。 相似文献
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《Measurement》2016
Milling is the most feasible machining operation for producing slots and keyways with a well defined and high quality surface. Milling of composite materials is a complex task owing to its heterogeneity and the associated problems such as surface delamination, fiber pullout, burning, fuzzing and surface roughness. The machining process is dependent on the material characteristics and the cutting parameters. An attempt is made in this work to investigate the influencing cutting parameters affecting milling of composite laminates. Carbon and glass fibers were used to fabricate laminates for experimentations. The milling operation was performed with different feed rates, cutting velocity and speed. Numerically controlled vertical machining canter was used to mill slots on the laminates with different cutting speed and feed combinations. A milling tool dynamo meter was used to record the three orthogonal components of the machining force. From the experimental investigations, it was noticed that the machining force increases with increase in speed. For the same feed rate the machining force of GFRP laminates was observed to be very minimal, when compared to machining force of CFRP laminates. It is proposed to perform milling operation with lower feed rate at higher speeds for optimal milling operation. 相似文献
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Optimization of multi-pass face milling using a fuzzy particle swarm optimization algorithm 总被引:1,自引:1,他引:0
Wen-an Yang Yu Guo Wen-he Liao 《The International Journal of Advanced Manufacturing Technology》2011,54(1-4):45-57
In this paper, a simple methodology to distribute the total stock removal in each of the rough passes and the final finish pass and a fuzzy particle swarm optimization (FPSO) algorithm based on fuzzy velocity updating strategy to optimize the machining parameters are proposed and implemented for multi-pass face milling. The optimum value of machining parameters including number of passes, depth of cut in each pass, speed, and feed is obtained to achieve minimum production cost while considering technological constraints such as allowable machine power, machining force, machining speed, tool life, feed rate, and surface roughness. The proposed FPSO algorithm is first tested on few benchmark problems taken from the literature. Upon achieving good results for test cases, the algorithm was employed to two illustrative case studies of multi-pass face milling. Significant improvement is also obtained in comparison to the results reported in the literatures, which reveals that the proposed methodology for distribution of the total stock removal in each of passes is effective, and the proposed FPSO algorithm does not have any difficulty in converging towards the true optimum. From the given results, the proposed schemes may be a promising tool for the optimization of machining parameters. 相似文献