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基于微分几何理论,对复杂曲面环形刀无干涉刀具路径生成算法进行研究,对复杂曲面进行曲面划分,在此基础上建立环形刀五轴加工模型,进行走刀步长、加工行距和相邻刀触点等的计算,并提出通过选择最佳刀具尺寸和改变刀具姿态进行干涉避免的方法.与其它环形刀刀具路径生成算法相比,本文提出的算法具有更高的准确性和可靠性. 相似文献
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换刀机构中的复合凸轮完成刀具的插拔、转位动作,旋转动作通过弧面凸轮实现,直进运动由平面沟槽凸轮和正弦型从动件来实现.因为平面沟槽凸轮是加工在弧面凸轮的端面上,所以这种凸轮则成为复合凸轮.想要深入研究凸轮副的动力学性能,需要使用CAE技术,而前提是复合凸轮的精确建模,本文拟采用改进正弦加速度规律,使用Solidworks软件对圆弧凸轮的三维轮廓进行准确建模. 相似文献
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《机床与液压》2015,(18)
热柱冷凝端的表面结构对其传热性能的影响起着至关重要的作用,粗糙的微沟槽表面形貌有利于强化冷凝。提出了热柱冷凝端表面加工微沟槽的实验加工方法,建立了犁切挤压刀具加工热柱冷凝端的有限元模型。利用deform软件模拟犁切挤压刀具加工热柱冷凝端微沟槽,分析了微沟槽的成形过程及机理。有限元模拟结果表明:在加工环状沟槽时冷凝端表面形成了V形沟槽,两V形沟槽之间形成U形沟槽,V形沟槽两端有鼓包,形成沟槽翅。在轴向沟槽加工时,表面形成了相互正交的微沟槽,呈现许多U形微沟槽。进给量和犁切挤压深度对热柱冷凝端微沟槽形貌起着重要作用,犁切挤压深度越大,微沟槽表面形貌越粗糙,但是受刀具强度和刚度的影响,犁切挤压深度不能过大。进给量过大和过小,都不利于微沟槽表面形貌,只有当进给量恰当,才能形成最优的微沟槽表面形貌。 相似文献
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爆破片是安全阀内部气压控制的关键零部件,其爆破压力由表面预制的缺陷特征控制,影响因素多、加工精度要求高.根据环形沟槽截面轮廓的周向一致性和旋转对称性,提出采用薄壁圆筒电极旋转放电加工预制缺陷特征,解决了几何特征可控性问题;在此基础上,进一步提取沟槽截面轮廓特征,通过模型仿真和实验测试确定了决定零件爆破压力的最主要几何特征,并进一步确定了满足目标爆破压力的加工流程.基于以上工作,定量给出了满足目标爆破压力范围的关键几何特征容许区间,并在后续验证实验中取得了良好的加工效果,实现了特定爆破压力的平板圆形爆破片零件的高效高质量加工. 相似文献
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热柱冷凝端的表面结构对其传热性能的影响起着至关重要的作用,粗糙的微沟槽表面形貌有利于强化冷凝。提出了热柱冷凝端表面加工微沟槽的实验加工方法,建立了犁切挤压刀具加工热柱冷凝端的有限元模型。利用deform软件模拟犁切挤压刀具加工热柱冷凝端微沟槽,分析了微沟槽的成形过程及机理。有限元模拟结果表明:在加工环状沟槽时冷凝端表面形成了V形沟槽,两V形沟槽之间形成U形沟槽,V形沟槽两端有鼓包,形成沟槽翅。在轴向沟槽加工时,表面形成了相互正交的微沟槽,呈现许多U形微沟槽。进给量和犁切挤压深度对热柱冷凝端微沟槽形貌起着重要作用,犁切挤压深度越大,微沟槽表面形貌越粗糙,但是受刀具强度和刚度的影响,犁切挤压深度不能过大。进给量过大和过小,都不利于微沟槽表面形貌,只有当进给量恰当,才能形成最优的微沟槽表面形貌。 相似文献
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圆周分布孔系的加工在生产中比较常见,根据孔系分布的环数、射线数、孔距等的不同,走刀路线的长度不同。在保证质量的条件下,应以最短的走刀路线进行编程加工,以提高加工的效率,降低成本。以沿环形走刀和沿射线走刀两种方式为例,分别建立了走刀路线长度计算的数学模型,编制出能自动选择最短走刀路线进行加工的宏程序,实现对走刀路线及加工程序的优化设计,提高了加工效率。 相似文献
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为消除PCD刀具孔加工过程中出现的划痕,通过分析划痕的类型和出现的原因,设计试验验证优化刀具角度和增加喷淋手段等方式对内孔表面质量的影响。结果显示:入口划痕产生的原因是粗加工刀具产生的铝环切屑残留在工件内,被精加工刀具再次切削时划伤工件内表面。优化喷淋方式对改善入口划痕效果较差;通过调整加工工艺,并优化精加工刀具刃口主偏角(从85°减小到48°),可以减小铝环厚度并遏制铝环的形成。实际生产显示该方法可消除阀体成品中残留铝环的现象,提高内孔表面质量。 相似文献
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3- and 4-Contact Point Spindle Bearings - a new Approach for High Speed Spindle Systems 总被引:1,自引:0,他引:1
One important demand on spindle systems in modem machine tools is to realise higher rotational speeds in order to increase the machining efficiency. In conventional spindle bearings the contact angles on inner and outer ring deviate extremely from one another with rising rotational speeds due to centrifugal forces. Axial shift of trie inner ring (elastic mounted bearing) and increasing normal forces in the contact zones on the outer ring are typical consequences leading to high internal bearing loads and a reduced life span. Based on these problems bearings with a new inner geometry are studied. Instead of two contact zones these bearings have three or four contact zones to ensure constant contact angles and reduced normal forces on the outer ring. In this paper analytic operation studies and first experimental tests are presented. 相似文献
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阀套是液压伺服系统中的一重要零件,圆柱面上方孔电火花加工及内环槽电磨削精度要求很高,加工难度大,加工合格率通常不足60%.通过对加工过程进行优化,稳定了环槽加工尺寸,设计了与设备相连接带油路的组合夹具之后,有效地改善了电火花加工方孔时的“烧伤”缺陷,一次加工合格率能达到92%.由于组合夹具一次装夹,能同时加工六个阀套零件,单件加工时间也缩短了30min.该电火花加工方法和组合夹具的结构对类似零件的加工具有一定的借鉴作用. 相似文献
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本文以纺织配件钢领为例,对普通内圆表面和小孔径(〈20mm)内圆表面磁性研磨加工进行了试验研究。分析了不同加工参数对被加工内圆表面粗糙度和研磨量的影响。加工小孔内圆时,采用了轴向开圆槽的研磨棒,以改善磁场中磨料流的均匀性。得出了内圆表面磁性研磨加工的优化参数为:磁感应强度B〈1.2T,加工间隙△=1mm,研磨时间t=4min,工作轴向振动频率f=10Hg。 相似文献
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全自动CNC镗削活塞销孔专机的研究开发 总被引:4,自引:0,他引:4
所研制的全自动CNC镗削活塞销孔专用机床可以实现工件的自动上、下料和自动定位、夹紧,并且在一次安装、不停机、不换工位的情况下,高效地完成活塞销孔的镗孔、镗外口、切挡圈槽、倒内角和倒外角。该机床已在上海活塞厂投入生产,并取得了良好的加工效果。 相似文献
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T. Aoyama 《CIRP Annals》2002,51(1):289-292
The minimal quantity lubrication (MQL) technique is used in cutting processes in order to reduce the environmental pollution caused by cooling lubricants. However, there can be problems with the MQL technique in high-speed machining. In high-speed machining, a spindle-through coolant supply method can effectively supply an oil mist to the cutting area. However, the centrifugal force from the high-speed rotation of the spindle causes the oil mist to separate. As a result, there is a decrease in the oil mist supplied to the cutting area. In this study, a new oil-mist supply mechanism was developed and installed in a high-speed spindle system. The performance of this proposed mechanism was evaluated by numerical simulation and an actual cutting test. 相似文献
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K.A. Desai Piyush K. Agarwal P.V.M. Rao 《International Journal of Machine Tools and Manufacture》2009,49(12-13):1015-1028
Prediction of cutting forces and machined surface error in peripheral milling of curved geometries is non-trivial due to varying workpiece curvature along tool path. The complexity in this case, arises due to continuously changing process geometry as workpiece curvature varies along tool path. In the presence of cutter runout, the situation is further complicated owing to changing radii of cutting points. The present work attempts to model process geometry in machining of curved geometries and in the presence of cutter runout. A mathematical model computing process geometry parameters which include cutter/workpiece engagements and instantaneous uncut chip thickness in the presence of cutter runout is presented. The developed model is more realistic as it accounts for interaction of cutting tooth trajectory with that of preceding teeth trajectories in computing process geometry. Computer simulation studies carried for this purpose has shown that it is essential to account for teeth trajectory interactions for accurate prediction of process geometry parameters. This aspect is further confirmed with machining experiments, which were conducted to validate this aspect. From the outcomes of present work, it is clearly seen that the computation of process geometry during machining of curved geometries and in presence of cutter runout is not straightforward and requires a systematic approach as presented in this paper. 相似文献