共查询到20条相似文献,搜索用时 93 毫秒
1.
2.
对用于铜箔和铜管连续缝焊的超声波焊接机的气动和控制系统进行了设计分析。根据焊接工艺,拟定了气动回路,进行了气动元件的选择计算,确定了管道直径,验算了压力损失。拟定了PLC控制流程并对控制端口进行了分析,编写了控制程序,实现了铜箔和铜管的自动焊接。 相似文献
3.
用三维CAD手段优化螺旋离心式叶轮动平衡问题 总被引:2,自引:0,他引:2
本文叙述了根据动平衡的力学原理,借助于三维CAD软件的功能,优化设计了螺旋离心式潜水排污泵叶轮,较好地解决了螺旋式叶轮的动平衡问题。在减少了加工去重量、降低了叶轮制作成本的同时,还改善了产品的质量、提高了泵的工作效率,达到了较好的综合实效。 相似文献
4.
5.
建立了某硅微陀螺仪的等效电路,分析了寄生电容对接口电路的影响。结果表明,合理的接口电路不仅消除了大部分寄生电容的影响,而且减小了信号的衰减幅度,抑制了大部分的耦合信号和噪声信号。最后对接口电路进行了改进,保留了以上的优点,减小了载波信号的变化和电源变化对分辨率的影响,提高了整个电路的分辨率。 相似文献
6.
7.
本文讨论了轴的可靠性设计CAD 方法。文中提出了轴的疲劳强度可靠性设计CAD 程序的编制原则,并给出了相应的CAD 程序和应用例子。这种可靠性CAD程序简化了计算,节省了时间,提高了设计质量,减少了轴的尺寸。 相似文献
8.
分析了四齿短轴的冷挤压工艺,设计了冷挤压件图,计算及选用了毛坯尺寸及形状,验算了许可变形程度,选择了变形用的设备,拟订了冷挤压前的毛坯处理及设计了冷挤压模具结构。 相似文献
9.
通过工艺分析与研究,改进了铁路客车底架牵引梁的结构,选取了优质材料,优化了制造方法,降低了成本,提高了工作效率,产品精度有了很大提高,同时提高了车辆的承载能力,延长了使用寿命,现已广泛用于国内及出口车辆的制造,并获得了国家发明专利. 相似文献
10.
液压万能材料试验机油路部分改造和数据库联网功能实现 总被引:1,自引:0,他引:1
本文提出了液压万能材料试验机的油路改造办法,引入了比例溢流阀,并分析了其PID控制算法,建立了系统的总体组成,实现了数据库联网的功能,达到了改造的性能目标。 相似文献
11.
An indirect measurement method based on recording the phase difference of resonance vibrations of two symmetrical halves of the flow-carrying tube is used to quantify the mass flow rate of the current fluid in Coriolis mass flowmeters (CMFs). A variant of modeling the CMF vibration system is analyzed, which allows taking into account the influence of the dissipation of oscillations of a measuring tube with fluid flowing through it on the dependence between the mass flow rate of the fluid and the phase difference recorded by the sensor. The steady-state CMF vibration mode is considered as the result of the superposition of two principal vibrations of the measuring tube. The first principal coordinate corresponds to the deformation of the measuring tube along the lowest natural mode excited by an external driving force in the resonance mode. Vibrations of the other principal coordinate correspond to deformation in a natural mode corresponding to a higher natural frequency than the frequency of the exciting force. The relationship of the amplitudes of the principal coordinates is established on the basis of the gyroscopic coupling of the principal vibrations that occurs when a fluid flows through a tube. The coefficients of gyroscopic coupling are determined as a result of 3D finite-element simulation of the steady-state vibration mode of the measuring tube with a flowing fluid. The simulation is performed for five variants of the shape of the axis of the measuring tube, taking into account the distribution of the gyroscopic forces of the flowing fluid. Quantitative estimates of the influence of dissipative forces on the flowmeter readings are obtained on the example of dissipative forces of linear viscous friction. A comparison of the CMF simulation results for different tube axis shapes demonstrates how the phase shift arising in the vibration system is affected by the dissipation level and the proximity of the natural frequencies of the flowmeter measuring tube at a fixed mass flow rate of the fluid. 相似文献
12.
13.
韧性材料的几种断裂形式及判据讨论 总被引:13,自引:3,他引:13
考察几种韧性材料的复合型断裂试验过程,用传统强度理论思想认定启裂位置与启裂方向,通过对不同物理机制的断裂形式变化规律的研究,判定韧性材料的主要断裂形式有三类,以空穴成核、扩张、聚合为主导机制的正拉断,和以局部剪切带形成、发展为主导机制的两种不同类型的剪切断裂。局部大塑性变形的出现在材料内引起损伤,空穴的聚合或局部剪切带的出现仅发生在载荷达到某一临界值时。导致材料断裂发生的根本因素,是危险点上某应力参数达到了材料的断裂临界值,以此对不同断裂形式的断裂判据进行讨论,提出新的韧性断裂判据。 相似文献
14.
减振器的主要功能是提供阻尼力以衰减和抑制车辆系统振动,对高速动车组动力性能有十分重要的影响。既有研究主要将减振器处理为阻尼力以研究车辆系统动力性能,极少从动力学和结构可靠性角度关注减振器自身承受的载荷。制作某型高速动车组转向架抗蛇行减振器、轴箱减振器、二系横向和垂向减振器测力元件,在大同-西安高速线路上测试并获得该型动车组运行过程中四种减振器载荷引起的应变信号。对测试数据进行处理和分析,获得高速动车组运行工况下四种减振器载荷的时间历程,分析减振器载荷的时域和频域特征。采用雨流计数法统计减振器载荷峰谷值和频次,获得不同速度等级下载荷分布。结果表明,高速动车组抗蛇行减振器载荷最大、二系横向减振器载荷最小。轴箱减振器相对速度最大、二系横向减振器相对速度最小。减振器载荷总体上呈正态分布,而且一般有列车运行速度越高减振器载荷越大。列车正线行驶时曲线半径对轴箱减振器、二系垂向减振器以及二系横向减振器载荷影响不明显,列车速度和线路小半径曲线对抗蛇行减振器载荷影响明显。 相似文献
15.
Zygmunt Towarek 《International Journal of Mechanical Sciences》1998,40(6):557-574
In this work the influence of flexible soil foundation on the dynamic stability of the boom crane is presented. This analysis was made during the rotation of the boom, such that variable pressure on the soil and other deformations could be taken into account. The rheological deformation of the soil as a function of the changing strain in time has been described by an equation, which is the Duhamel integral. After accepting the discrete model of the considered system dynamic equations of motion were elaborated, which because of their nonlinearity and complexity were solved numerically. Appointed were the dynamic displacements of each of the supports for different rotational speeds of the boom, showing the influence of the rheological deformation of the soil on the behaviour of the whole crane. As well the trajectories of the motion of the weight hoisted were presented for different rotational speeds of the boom, which enabled the analysis of the precision of the positioning of the weight being hoisted (minimization of oscillation). 相似文献
16.
17.
18.
为解决包装机抱袋装置运动过程中产生机械振动及减小末端执行构件冲击的问题,首先根据运动要求建立机构模型,通过对装置运动中约束条件进行分析,得到摆臂转轴处角位移、角速度及角加速度,以及摆臂末端位移、速度及加速度的数学表达式。其次对数值计算与运动算例分析,以摆臂转轴处角加速度与末端加速度峰值为优化目标,对机构结构参数进行优化。结果表明:通过改变机构结构参数可以降低摆臂转轴处与末端加速度峰值,装置运动过程中摆臂转轴处角加速度峰值降低25.89%,抱袋口末端加速度峰值降低20.46%,抱袋身末端加速度峰值降低24.87%,在一定程度提高运动平稳性。相关结论可为后续动力学分析与设计提供理论依据。 相似文献
19.