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给出了凸轮机机构等在各种情况下多项式运动规律的通用方程式及边界条件,开发了适用于各种情况的可以任意增加局部控制条件多项式运动规律的通用设计软件。 相似文献
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对于平面直动和摆动从动件凸轮(连杆)机构,当把复杂的从动件运动规律应用于凸轮机构的合成设计或简化设计时,本文给出了精确计算凸轮机构最大压力角及其作用位置,以及根据允许压力确定基本尺寸的一般方法。本文给出的计算公式,适用于计算器的手算和电算。本文末给出了几个计算实例,并由这些实例中的已知条件,分析了各种不同的从动件运动规律对最大压力角及其作用位置的影响。 相似文献
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本文根据凸轮基圆半径的解析计算公式,分析推导了凸轮机构基本尺寸优化设计的数学模型。由此编制的设计计算程序,不仅适用于无约束条件时凸轮机构基本尺寸的优化设计,同时也适用于有约束条件时凸轮机构基本尺寸的优化设计,并且从动件运动规律可以是各种运动规律的任意组合或改进型。 相似文献
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粉柱成型凸轮机构在高速运转时,会引起从动件较大的弹性变形,机构会出现严重振动,从动件输出端运动将偏离预期运动,产生无法忽视的动态误差。此时采用传统方法所设计的凸轮机构运动规律无法完全满足工作需求,为此本文提出一种基于动力学性能的高速凸轮运动规律设计方法。首先建立凸轮传动系统的动力学模型,对其进行动力学分析。然后根据所得凸轮系统动力学特性建立动力学性能评价指标,再将样条曲线作为过渡曲线,建立优化目标函数,并通过遗传算法实现目标函数的求解。在以动力学指标为主的同时,本文还综合考虑了其它运动学指标,保证了高速凸轮机构从动件输出端的运动和动力稳定性,为高速凸轮机构运动规律的设计提供了一个实用的基于动力学性能的设计方法。 相似文献
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设计平面凸轮轮廓的新方法 总被引:10,自引:0,他引:10
提出了设计平面凸轮轮廓的相对运动法,这是一种适用于各种平面凸轮轮廓设计的通用方法。利用从动件相对凸轮运动的相对速度、相对加速度和从动件的表面法线确定平面凸轮的轮廓方程、压力角和曲率半径是该方法的基本原理。通过建立基于反转原理的通用模型、坐标系和齐次坐标变换技术,导出了平面凸轮的轮廓方程、压力角和曲率半径的一般表达式。该推导过程不仅适用于手工完成,而且为平面凸轮轮廓设计的智能化、自动化打下了基础。根据设计的自动推导和求解策略,用C++和OpenGL语言开发了计算机辅助设计程序实现了平面凸轮轮廓设计和机构运动仿真的自动化。最后,给出了设计和仿真实例。 相似文献
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针对当前配气机构在高速运动过程中存在噪声大、精度低等问题,采用改进B样条曲线设计凸轮轮廓.创建了配气机构模型简图,采用B样条曲线函数设计凸轮轮廓.确定凸轮轮廓控制的设计变量,构造优化目标函数,对凸轮运动条件进行约束,引入了改进粒子群算法优化B样条曲线.采用Matlab软件对优化后配气机构动力学性能进行仿真,并与优化前动力学性能进行对比和分析.仿真曲线显示:优化前,挺柱产生的最大加速度值为2.34mm/deg~2,运动误差为0.5mm,凸轮与挺柱接触力值出现零的情况;优化后,挺柱产生的最大加速度值为2.04mm/deg~2,运动误差为0.1mm,凸轮与挺柱接触力值没有出现零的情况.配气机构凸轮采用改进粒子群算法优化B样条曲线,提高了凸轮运动精度,降低了机构振动幅度,避免了凸轮与挺柱产生脱落现象. 相似文献
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Metal flowing of involute spline cold roll-beating forming 总被引:3,自引:2,他引:1
CUI Fengkui WANG Xiaoqiang ZHANG Fengshou XU Hongyu QUAN Jianhui LI Yan 《机械工程学报(英文版)》2013,26(5):1056-1062
The present research on involute spline cold roll-beating forming is mainly about the principles and motion relations of cold roll-beating,the theory of roller design,and the stress and strain field analysis of cold roll-beating,etc.However,the research on law of metal flow in the forming process of involute spline cold roll-beating is rare.According to the principle of involute spline cold roll-beating,the contact model between the rollers and the spline shaft blank in the process of cold roll-beating forming is established,and the theoretical analysis of metal flow in the cold roll-beating deforming region is proceeded.A finite element model of the spline cold roll-beating process is established,the formation mechanism of the involute spline tooth profile in cold roll-beating forming process is studied,and the node flow tracks of the deformation area are analyzed.The experimental research on the metal flow of cold roll-beating spline is conducted,and the metallographic structure variation,grain characteristics and metal flow line of the different tooth profile area are analyzed.The experimental results show that the particle flow directions of the deformable bodies in cold roll-beating deformation area are determined by the minimum moving resistance.There are five types of metal flow rules of the deforming region in the process of cold roll-beating forming.The characteristics of involute spline cold roll-beating forming are given,and the forming mechanism of involute spline cold roll-beating is revealed.This paper researches the law of metal flow in the forming process of involute spline cold roll-beating,which provides theoretical supports for solving the tooth profile forming quality problem. 相似文献
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基于样条函数法的机器人运动轨迹规划 总被引:3,自引:1,他引:3
利用样条函数法开发了一种机器人运动轨迹的规划方法,即各关节的运动采用样条函数来拟合。该法使用简便、计算量小,而且不会出现机构奇异点问题,可生成光滑平稳的无噪音机器人运动轨迹 相似文献
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Lin Zhu Shuang-Shuang Peng Cheng-Long Yin Tien-Chien Jen Xi Cheng Yi-Hsin Yen 《The International Journal of Advanced Manufacturing Technology》2014,70(5-8):995-1007
In this paper, using the specifications of nodal points on a nonuniform rational B-spline (NURBS) curve of three degrees with respect to NURBS curve parameter and defining the coefficients for the velocity and acceleration vectors on these points, a new method is presented to design a tool path via C2 PH spline curves. Values of the velocity/acceleration vector coefficients corresponding to the nodal points on the original NURBS curve are computed by pattern search algorithm. To this end, the normal distance between the constructed C2 PH spline curve and its corresponding original NURBS curve is considered as the objective function. Using combination of the time-dependent feed rate interpolation in the acceleration/deceleration phase of the motion and the constant feed rate interpolation in the middle region of the motion, the position commands of the designed NURBS-based C2 PH spline curve are generated. Several improved NURBS-based C2 PH spline curve following tasks were implemented with pseudo-derivative feedback feed forward (PDFF) controller. The experimental and simulation results confirm that the devised interpolator with designed PDFF controller is not only feasible for machining the complicated tool path represented in the improved NURBS-based C2 PH spline form but also yields satisfactory contouring performance under variable feed rate. 相似文献
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Based on investigation of the process of transformation of primary energy into mechanical work, criteria and laws general for the dynamics of different drives have been found. The control function is the basis for formation of dimensionless criteria. For electric, hydraulic, and pneumatic drives, function expressions have been obtained. A general procedure of use of the control function for selecting rational drive parameters according to the conditions of control in response to the prescribed law of motion of the output link is suggested. 相似文献
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本文对斜针刺布机构--离散点凸轮与11杆连杆组合机构进行运动模拟,提出用三次样条函数模拟凸轮机构的运动,研讨建立三回路复矢量与一维搜逼近相结合的方法,有效地解决了多连杆机构中斜杆复合运动问题,为圆头锁眼机的改进设计提供了依据。 相似文献