Z8025射芯机制作气缸体曲轴箱砂芯热芯盒的优化设计

分析评述了Z8025射芯机用热覆膜砂制作气缸体曲轴箱砂芯的两种不同结构方案。着重比较分析了其芯盒本体、漏模板、底座、射砂口结构,热覆膜砂挡砂帽等结构及附件的优缺点;提出了应用人类工效学、美学及绩效理论等对其优化设计的理念。     

基于形态滤波的发动机气缸压力信号处理

在信号预处理中采用了多项式最小二乘法去除信号的趋势项,并采用数学形态学的不同组合结构形式对二冲程发动机的缸内压力信号进行分析处理,可以去除受采集所引起的零漂的影响,滤除受点火脉冲等干扰的噪声。在滤波过程中,采用广义的不同结构元素组合顺序的形态滤波方式对实验数据进行处理,结果表明：此方法能有效地对发动机气缸压力信号进行趋势项去除处理并降噪。     

Cyclic moving average control approach to cylinder pressure and its experimental validation

Cyclic variability is a factor adversely affecting engine performance. In this paper a cyclic moving average regulation approach to cylinder pressure at top dead center （TDC） is proposed, where the ignition time is adopted as the control input. The dynamics from ignition time to the moving average index is described by ARMA model. With this model, a one-step ahead prediction-based minimum variance controller （MVC） is developed for regulation. The performance of the proposed controller is illustrated by experiments with a commercial car engine and experimental results show that the controller has a reliable effect on index regulation when the engine works under different fuel injection strategies, load changing and throttle opening disturbance.     

Numerical investigation of drag force on flow through circular array of cylinders

A 2-D model for flow through a circular patch with an array of vertical circular cylinders in a channel is established using the Navier-Stokes equations with a hybrid RANS/LES turbulence model–the Scale Adaptive Simulation (SAS) model. The applicability of the model is first validated by test cases where experimental data are available for comparison with the computed results. It is verified that the present model can predict well the average velocity and turbulence structure. The drag force and drag coefficient are then calculated using the present model for a number of cases with different solid volume fractions, cylinder Reynolds numbers and patch diameters. It is shown that the drag coefficient increases with increasing solid volume fraction, but decreases with increasing Reynolds number. However, the drag coefficient is independent of the diameter of circular batch when the solid volume fraction and Reynolds number are kept constant.     

内燃机气缸压力故障阈值制定方法研究

确定精确的诊断阈值是故障诊断工作中的重要环节。为减少内燃机故障诊断中的漏诊或误诊现象,通过内燃机失火、死火工况下各缸峰值压力数据分析,针对各缸工作的不均匀性,提出了基于单缸峰值压力的3σ阈值制定法和基于单缸峰值压力偏差的阈值制定法。试验结果表明,这2种方法制定的阈值能准确地诊断出内燃机气缸的故障。     

4M16—111．5／29-Ⅰ型活塞式氧压机改造

4M16—111．5／29-Ⅰ型氧压机作变型设计，改用4M16—116／20-Ⅲ型对机组二三级气缸、活塞杆进行改造。结果一级排气温度降低，氧气产量增加，实际运行情况良好，取得了较好的经济效益。     

空调器双气缸旋转式压缩机的特点及抱轴故障解救办法

压缩机是空调器的心脏，由于昼夜运转，使得压缩机内油膜受损，冷冻油失去润滑作用，在冬季制热时压缩机不起动，抱轴现象经常出现。其功率在0．75KW～4KW，制冷量在2．2KW左右。     

气缸头模具叶片电极设计加工新方法

一、摩托车发动机气缸头模具的特点气缸头是摩托车发动机的一个非常重要的关键零件,其作用是形成气缸的工作容积和为活塞运动导向,在高温、高压、润滑不良、交变载荷和腐蚀等条件下工作。为增加冷却面积,保证散热充分,在其外表面铸有许多散热片,并有大量的支撑筋。叶片、筋等在     

专用半自动铣床的设计

为了大批量加工铝合金小轴的花键槽，设计了专用半自动铣床。利用控制电路自动控制三个气缸的协调动作，实现了手工装上工件后的自动铣削、自动分度和完工后自动停机，使生产效率比万能铣床提高7～8倍。端面具有防转凸棱的复合顶尖实现了一个顶尖定心和防滑转的双重功能，从而简化了机床的结构，减少了工件装卸的时间。     

介绍一种气液转换高推力气缸

介绍一种气液转换高推力气缸宋慧生（天水轴承仪器厂天水７４１００１）在引进、消化某国自动线时，接触到一气液转换高推力气缸。该缸用来铆压密封轴承金属卷边防尘盖，具有动作平稳柔和，控制操纵简便及节能的特点。１气缸原理见图：图１气缸原理图整个气缸由大气缸Ａ、...