双转轴平板绘图机设计与实现

本文介绍了双转轴绘图仪的结构设计和控制系统的设计,重点讨论了结构设计中的方案选择和控制算法并给出了影响绘图仪精度几种误差因素,实际证明了绘图仪能够满足理想的精度。     

双转轴支撑机构的虚拟样机设计及其运动学仿真

基于虚拟样机技术及仿真软件平台Pro/E,设计开发了风洞试验模型的双转轴支撑机构,建立了角度控制的数学模型,实现了机构的虚拟样机设计和运动学仿真,荻取了被测试验模型运动情况的运动参数曲线,并对双转轴机构实施了干涉的动态检查,为双转轴机构设计方案的交流与评估,以及双转轴机构的制造与应用奠定了基础.     

虚拟样机技术在双转轴支撑机构设计中的应用

基于虚拟样机技术及仿真软件平台Pro/E,设计开发了风洞试验模型的双转轴支撑机构,建立了角度控制的数学模型,实现了机构的虚拟样机设计和运动学仿真,获取了被测试验模型运动情况的运动参数曲线,并对双转轴机构实施了干涉的动态检查,为双转轴机构设计方案的交流与评估以及双转轴机构的制造与应用奠定了基础.     

转轴疲劳强度的可靠性设计

提出了采用复合应力法建立转轴的疲劳强度可靠性设计的理论,该方法与安全系数法相比计算简便,易于转轴工程可靠性设计与应用。     

断路器转轴焊夹具的设计与制造

以ZW8-12转轴焊夹具为例来介绍一种通用的断路器转轴焊夹具的设计方法及制造工艺，对高压开关行业其他断路器转轴焊夹具的设计及制造具有参考作用。     

对转轴流泵的设计与数值分析

对转轴流泵是由2个叶轮串联在一起,以相反的方向绕同一轴心旋转的轴流泵.与常规前、后导叶式轴流泵相比,在同样设计参数条件下,对转式轴流泵具有相对体积小、运转速度低、抗空化性能好和推重比高等特点.为探究对转轴流泵的设计理论和方法,设计了一对转轴流泵的前、后置叶轮,应用Matlab软件实现参数化设计,搭建了自动分析优化平台,...     

行星轮转轴等宽曲线泵设计与仿真实验分析

目前国内大部分微型泵都是进口国外的,微型泵的设计技术被垄断,为了解决工程机械、海洋船舶、航空航天、医疗等行业的需求,设计了一种微型大排量的等宽曲线泵.依据莱洛三角形在等边正方形内旋转运动时,每时刻都有四个位置与正方形相交且交点不断变化原理,分析运动过程轨迹,设计出了行星轮传动机构,并应用ADMAS软件创建模型分析机构运...     

双泵供油同步回路设计与研究

本文介绍一种用于液压泵向三个液压缸供油，使三个液压缸以互成120度角的关系进行同步运动的液压回路。     

双楔角斜楔机构的设计

通过对斜楔机构的运动分析和受力分析，提出对双楔角斜楔机构设计的具体方法。     

Type synthesis of two-degrees-of-freedom rotational parallel mechanism with two continuous rotational axes

The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model. It is therefore easy to implement trajectory planning, parameter calibration, and motion control, which allows for a variety of application prospects. However, no systematic analysis on structural constraints of the 2R-PM with two CRAs has been performed, and there are only a few types of 2R-PM with two CRAs. Thus, a theory regarding the type synthesis of the 2R-PM with two CRAs is systematically established. First, combining the theories of reciprocal screw and space geometry, the spatial arrangement relationships of the constraint forces applied to the moving platform by the branches are explored, which give the 2R-PM two CRAs. The different distributions of the constraint forces in each branch are also studied. On the basis of the obtained structural constraints of branches, and considering the geometric relationships of constraint forces in each branch, the appropriate kinematic chains are constructed. Through the reasonable configuration of branch kinematic chains corresponding to every structural constraint, a series of new 2R-PMs with two CRAs are finally obtained.     

硬质合金刀片圆角数控磨削的程序算法

提出一种用三坐标数控磨床对硬质合金刀片圆角进行磨削的程序算法。在算法中 ,将待加工的曲面离散为一系列小平面 ,然后通过建立瞬态坐标系以及对相关节点和矢量进行坐标变换 ,可以计算出机床的三个轴在相应位置的位移增量     

Design and analysis of a class of redundant collaborative manipulators with 2D large rotational angles

The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to construct 2D rotational degrees of freedom (DOFs), a platform with 2D revolute joints is proposed first. Based on the constraint screw theory, the feasible limbs that can be connected in the platform are synthesized. In order to provide constant rotational axis for the platform, a class of redundant limbs are designed. A class of redundant 2R1T parallel spindle heads is obtained by connecting the redundant limbs with the platform and the redundant characteristics are verified by the modified Grübler-Kutzbach criterion. The corresponding 5-axis collaborative manipulators are presented by constructing a 2-DOF series translational bottom moving platform. The inverse kinematics and the orientation workspace as well as the decoupling characteristics of this type of 2R1T parallel spindle heads are analyzed. The results show that these manipulators have large 2D rotational angles than the traditional A3/Z3 heads and can be potentially used in the application of multi-axis machine tools and the 3D printers.     

基于无线通讯开放式数控系统双轴同动的研究

利用PC、PLC以及无线通讯模块搭建了具有无线通讯功能的开放式数控系统的硬件平台,阐述了PC与PLC之间无线通讯的协议和实现原理。针对目前多轴联动数控插补存在的不足,提出了双轴同动新的数控插补方法,说明了双轴同动的控制原理。设计了PLC实现双轴同动的控制程序;利用Visual C++6.0开发了上位机PC机的通讯与控制软件。最后在立式铣床上进行了加工实验,实验结果表明双轴同动方法可行,在双轴同动模式下机床加工速度快,加工出来的产品表面粗糙度小。     

回转式飞剪机的设计和结构分析

介绍了回转式飞剪机的工作原理与剪切过程,进行了回转式飞剪的结构分析,该飞剪机采用曲柄传动、机械同步定位轴,保证了上下剪刃的定向、定位,使上下剪刃作回转运动,当上下剪刃相遇时完成剪切.     

一种新型旋转伸缩机构的设计与分析

通过空间剪叉机构与旋转机构的运动特征分析,组合二者提出了一种新型的旋转伸缩机构,并阐述了其工作原理与驱动原理。根据空间剪叉机构的运动特点,采用坐标变换方法,分析了杆件节点的运动变换关系,建立了该旋转伸缩机构展开过程运动学模型。通过计算,可得到展开过程中结构上节点位置、速度和加速度的变化规律。研究结果为其动力学研究和机构运动控制提供了理论指导和技术支持。     

An experimental study on the axial collapse characteristics of hat and double hat shaped section members at various velocities

In this study, the axial collapse tests were performed under either static (or quasi-static) or impact loads with several collapse velocities based on the expectation that para-closed sections of the front-end side members (spot welded hat and double hat shaped section members) would show quite different collapse characteristics from those for seamless section. The test results showed that both of the hat and double hat shaped section members failed in the stable sequential collapse mode in the static or quasi-static collapse tests, while the double hat shaped section members underwent the unstable collapse mode especially when the impact velocity is high. The mean collapse loads in the hat shaped section members increase with collapse velocity for all the cases of the static, quasi-static, and impact collapse tests. In the double hat shaped section members, however, the mean collapse loads decrease with increase in collapse velocity in the impact tests.     

双四杆机构的运动分析及其优化

双四杆机构因其数学模型复杂,其速度和加速度曲线一直是研究的难点。以啤酒装箱机为例,探讨了啤酒装箱机双四杆机构的运动分析及其优化问题。将数学建模的专用软件Mathematica引入到啤酒装箱机双四杆机构的运动分析中,得到了速度与加速度特性曲线,并在此基础上进一步对双四杆机构进行优化。最后用参数化T-FLEX CAD软件对优化结果的运动轨迹进行仿真验证,获得了令人满意的效果。     

Design and experimental study of a passive power-source-free stiffness-self-adjustable mechanism

Passive variable stiffness joints have unique advantages over active variable stiffness joints and are currently eliciting increased attention. Existing passive variable stiffness joints rely mainly on sensors and special control algorithms, resulting in a bandwidth-limited response speed of the joint. We propose a new passive power-source-free stiffness-self-adjustable mechanism that can be used as the elbow joint of a robot arm. The new mechanism does not require special stiffness regulating motors or sensors and can realize large-range self-adaptive adjustment of stiffness in a purely mechanical manner. The variable stiffness mechanism can automatically adjust joint stiffness in accordance with the magnitude of the payload, and this adjustment is a successful imitation of the stiffness adjustment characteristics of the human elbow. The response speed is high because sensors and control algorithms are not needed. The variable stiffness principle is explained, and the design of the variable stiffness mechanism is analyzed. A prototype is fabricated, and the associated hardware is set up to validate the analytical stiffness model and design experimentally.     

基于功率键合图的IC芯片粘片机并联焊头机构的动力学分析

这里基于功率键合图的原理和特点,建立了IC芯片粘片机并联焊头机构的功率键合图模型和动力学方程,并用Matlab/Simulink进行了仿真。结果表明:使用该方法可以用简明的图形方式直观揭示出机构的动力学特征,动力学方程建立的规则化便于计算机自动生成。