5/12钢筋靠模式弯箍机构设计与参数计算

为有效提高钢筋自动弯曲成形精度和效率,引入靠模成型设计方法,提出了一种新型的箍筋模钢筋弯箍设计方案.基于弹塑性变形理论,建立了钢筋弯曲过程中弯箍转盘转角与钢筋弯曲成形角度之间的数模方程,推导了钢筋弯曲过程中弯曲力以及弯箍转盘的转矩和功率与钢筋弯曲角度的函数关系式,并详细分析了它们随弯曲角度的变化规律,较为详细的研究分析了系统的各个参数,提出了确定各系统参数的方法.结果表明,该机构设计合理,满足使用要求,便于实现自动控制.     

模切机后靠规定位机构的修正设计

通过两种方法对模切机后靠规定位机构进行了修正设计,并对设计结果进行了比较,便于厂家根据实际需要进行选择。     

某一维弹道修正机构设计与气动特性分析

根据增阻减速原理设计了某一维弹道修正弹的修正机构,建立了弹体及修正机构的三维模型;结合外弹道理论和修正机构的工作特点,利用流体力学软件FLUENT建立了该一维弹道修正弹的弹道仿真模型,对修正榴弹的绕流流场进行了仿真分析,获得榴弹在不同马赫数下所受阻力、粘性力、阻力系数和粘性系数等参数,对比分析了所设计的修正机构的修正能力,为修正机构的工程设计提供一定的理论参考。     

法兰盘弯卷机构的改进与设计

法兰是一种常用的联接件,弯卷法是法兰最经济的加工方法。本文讨论了一种法兰弯卷机构,并对其进行改进与设计,实现了法兰加工时的连续进料,边弯卷边顶出边剪切,大大提高了法兰的生产效率。     

无钻机钻探机器人推靠支撑机构设计与分析

基于新型无钻机钻探机器人,设计一种推靠支撑机构,对其进行结构设计和工作模型分析。该机构结构上采用两对轴向交错排布的液压缸,既增加了推靠支撑的行程,又增强了径向支撑强度;同时前后支撑机构和牵引机构协调配合,实现井下钻探机器人的径向偏置和轴向导向姿态调整。对关键环节进行力学分析和设计参数校核,保障机构的稳定性。样机的液压系统在30 MPa压力下稳定溢流,为机器人的最大推靠支撑力达到40 kN提供了现实依据。     

鸭舵式二维弹道修正机构设计与动力学分析

提出并设计了一种新型的二维弹道修正机构,建立了动力学分析模型,并通过仿真分析,验证了新型修正机构的可行性及合理性.分析结果表明,该修正机构具有响应时间快、结构简单、同步性好、动作可靠等优点,满足对二维弹道修正能力的要求.这将为二维弹道修正结构的进一步设计和试验奠定良好的基础.     

中,低速包缝机弯针机构的设计理论与方法

本文在定量构造了机针与上、下弯针之间的动作协调关系基础上，提出了一种精确实用的中、低速包缝机弯针机构综合方法，并给出了工程实例。研究成果对促进我国包缝机产品的计算机辅助设计具有一定的指导意义。     

助餐机器人的机构设计与控制模式研究

研究了一种新型机器人-助餐机器人,它通过模拟正常人上肢取食时的动作,帮助手部活动功能丧失的人进食.介绍了它的机械结构和工作原理,利用MATLAB/SimMechanics建立助餐机械臂的运动学模型,分析了其作业空间.设计了机器人自动控制的3种模式.经过实验,样机能够完成对残疾人的饮食护理.     

多模式抓取欠驱动手的机构设计与力学分析

针对机器人末端执行器机械手多功能化的需求,提出了一种多模式抓取欠驱动手.该机械手基于欠驱动理论,解决了传统复合欠驱动手存在的结构复杂、控制元件多、适应能力不强等缺点.介绍了多模式抓取欠驱动机械手的结构组成和运动过程,建立了欠驱动手的数学模型;根据几何关系对机械手进行运动分析与适应性分析,并求得机械手抓取的参数范围;在不...     

基于有限元和响应面近似的卡箍连接处最大弯曲应力估算

在水下航行器壳体连接设计中,卡箍连接设计在实际工程中得到了广泛应用.水下航行器入水过程及其复杂,目前研究对卡箍连接处的力学分析还不够充分.先对水下航行器入水瞬间,卡箍连接处进行力学分析,然后使用有限元和响应面近似法对受力分析加以验证,最后对某型水下航行器卡箍连接处最大弯曲应力进行函数拟合.最后对通过拟合的某型水下航行器...     

Effects of process variables on V-die bending process of steel sheet

This investigation aims to clarify the process conditions of the V-die bending operation of steel sheet. It provides a model which predicts the correct punch load for bending and the precise final shape of products after unloading, in relation to the tensile properties of the material and the geometry of tools. The process variables are punch radius (R_p), die radius (R_d), punch width (W_p), punch speed (V_p), friction coefficient (μ), strain hardening exponent (n) and normal anisotropy (R).This investigation is carried out by performing some experiments and by finite-element simulation. Experiments determine the punch for bending for various process variables, such as punch radius, punch speed and lubrication, were carried out. As a result it was found that punch load increases as punch radius and punch speed increase or lubrication decreases.An elasto-plastic incremental finite-element computer code based on an updated Lagrangian formulation was developed to simulate the V-die bending process of sheet metal under the plane-strain condition. Isotropic and normal anisotropic material behavior was considered including nonlinear work hardening. A modified Coulomb’s friction law was introduced to treat the alternation of sliding–sticking state of friction at the contact interface. Simulation results, such as the punch load of bending and the bend angle of the bent part after unloading, are compared with experimental data; satisfactory agreement was observed. The simulation clearly demonstrates that the code to simulate V-die bending process was efficient.Simulations were made to evaluate the effects of die radius, punch width, strain hardening exponent and normal anisotropy on punch load of bending. The punch load for bending is smaller for materials with a larger strain hardening exponent. The effect of punch width on punch load is limited. The punch load decreases in the early stage and increases in the final stage of the bending process as the die radius increases. The influences of all of the process variables on the final bend angle of the bent parts of sheet after unloading were also evaluated. The effects of process variables except die radius on the bend angle after unloading are also limited. The angle of spring-back is greater for tools with larger die radius.     

偏曲轴少齿差行星传动机构优化数学模型的建立

通过对偏曲轴少齿差行星传动机构设计参数的分析,指出啮合角是影响机构传动性能的一个关键因素。在工程设计寻求结构体积最小方案时,应同时考虑啮合角的优化问题。考虑到设计中一些因素所具有的模糊性,建立了模糊多目标优化数学模型。此模型较好地处理了优化目标与关键设计参数的优化问题。并通过实例对优化方法及结果进行了分析。     

Modified mathematic model of a parallel two-dimensional piston flowmeter

The parallel two-dimensional piston (2D piston) flowmeter is a novel kind of positive displacement flowmeter that has been recently invented and proposed by our research group. Following an overview of the working principle of this flowmeter, a modified mathematic model was carefully established in this paper based on the analysis of the shortcomings of the presented primary model. The churning loss, as the first of two ignored parts in the previous research, is caused by the rollers rotation in oil, and it is considered a part of the torque balance equation in the pressure loss model. Besides, the flow rate of the transient leakage, which comes from the change in the leakage flow rate equation when the 2D piston rotates at a specific angle, was analytically modeled and added to the flow rate distribution equation. By comparing the experimental results from the last study, the modified mathematical model showed to be precise and became more suitable for predicting the flowmeter's performance and enhancing its measuring accuracy.     

机械构件的弯曲变形与弯曲刚度

分析了影响构件弯曲变形的主要因素及弯曲刚度与弯曲变形的联系和区别。对其在概念上的不同进行论述,并分析影响机械构件弯曲的主要因素,找出提高构件刚度的有效措施是零件结构设计的主要内容。     

硫酸风机装置性能的数值模拟及扩能

根据硫酸工序中风机系统的配置及风机能力不能满足生产需求的实际状况,对装置性能建立了数学模型,找出了影响性能发挥的因素,为硫酸风机装置性能满足使用要求提供了具有良好性价比的技术处置途径。     

三维无模弯管机器人的设计与控制

为了避免弯管作业对于模具的依赖,设计了一种不需要模具的三维弯管机器人,其主体包括机械机构和控制系统.弯管机构设计简单、结构紧凑,可对管件连续加工,完成三维无模弯管加工.从结构设计、工作原理方面进行了分析,并对关键机构进行了设计和运动学分析.根据三维无模弯管的控制要求,对机器人控制系统的硬件、软件进行了设计,利用触摸屏、...     

长臂式仿生软体机器人及其主动弯曲模型

针对软体机器人结构化分析困难的问题,对软体机器人气腔耦合结构、嵌入式加强材料以及充气状态下的弯曲变形等方面进行了研究,提出了一种新型的长臂式仿生软体机器人结构,该结构为多腔、多节耦合,可以实现任意方向的大范围弯曲。通过力矩平衡方程建立了长臂式仿生软体机器人的静态模型及主动弯曲数学模型,并实现了基节的各个力矩的数值化近似求解。采用上、下位机控制思想,基于ITV气压比例阀搭建了实验平台并设计、制作了软体机器人样机进行测试。研究结果表明,弯曲运动实验结果与仿真曲线基本一致,由此验证了理论模型的正确性。     

基于主应力线的软体气动弯曲驱动器设计

软体驱动器是软体机器人的重要组成部分.针对传统的设计方法难以设计具有特定功能的软体驱动器问题,提出一种基于主应力线的软体驱动器的设计方法,可以实现基于目标功能的设计.该方法基于给定的目标功能参数,通过预仿真计算主应力线方向,并沿着主应力线方向环绕气动腔室生成框架约束结构.最后,使用启发式的方法调节框架约束结构的材质参数...     

Establishment of a 3D FE model for the bending of a titanium alloy tube

Establishing and developing a finite element (FE) model is key to the effective study of the complex bending of a titanium alloy tube. This paper focuses on the establishment of a three-dimensional (3D) FE model for the numerically controlled (NC) bending of a titanium alloy tube that considers both bending and springback. The key procedures for establishment of the model are described in detail, including the choice of elements, mesh density control, the choice of single- or double-precision computation, and the choice of the mass scaling factor. Combining explicit and implicit FE methods, a significant amount of springback can be modeled for the bending, which is in good agreement with what is observed in practice. Single-precision computation tends to provide increasingly inadequate results as the mass scaling factor decreases. Analyses performed using double-precision computation can improve the accuracy of the results. A decrease in the mass scaling factor when double-precision computation is used leads to improved results to some degree, but also to an increase in computation time. Taking accuracy and efficiency into consideration, a mass scaling factor of 1600 is considered reasonable. Using our 3D FE model, results for the distributions and variations of the tangential stress, tangential strain, wall thickness, and springback angle for the bending of a TA18 M tube were obtained.