汽车发动机喷油、点火控制系统信号模拟与故障诊断仪器的设计

论述汽车发动机喷油、点火控制系统信号模拟与故障诊断仪器的设计原理、设计路线及仪器控制面板调试过程.诊断仪器可以实现离车诊断,同时也可以随车进行诊断,判断汽车运行过程中的故障信号.     

Accelerated testing of on‐board diagnostics

Modern products frequently feature monitors designed to detect actual or impending malfunctions. False alarms (Type I errors) or excessive delays in detecting real malfunctions (Type II errors) can seriously reduce monitor utility. Sound engineering practice includes physical evaluation of error rates. Type II error rates are relatively easy to evaluate empirically. However, adequate evaluation of a low Type I error rate is difficult without using accelerated testing concepts, inducing false alarms using artificially low thresholds and then selecting production thresholds by appropriate extrapolation, as outlined here. This acceleration methodology allows for informed determination of detection thresholds and confidence in monitor performance with substantial reductions over current alternatives in time and cost required for monitor development. Copyright © 2006 John Wiley & Sons, Ltd.     

液压启闭机常见故障及应急处理措施

本文针对岗南水库工程液压启闭机出现的常见问题，详细分析了问题产生的原因及常规检修内容、养护要求，提出了故障排除方法。     

Approach into the use of probabilistic neural networks for automated classification of tool malfunctions in broaching

The condition of broaching tools has crucial importance for the surface quality of the machined components. If undetected, tool malfunctions such as wear, chipping and breakage of cutting teeth can result in severe damage or even scrapping expensive components, with direct implications on increasing the overall manufacturing costs. In contrast with other machining operations, broaching is characterised by non-symmetric distributions of cutting forces vs. time, making more difficult the task of recognising tool malfunctions. The paper reports on a methodology to automatically detect and classify tool malfunctions in broaching. The method was demonstrated through the use of time domain distribution of the push-off cutting force as a key sensory signal to monitor broaching tool condition when machining a nickel-based aerospace alloy. The characteristic features of the sensory signals have been extracted using in-house-developed programs and, afterwards, used to train and test a probabilistic neural network that enables automated classification of tools with fresh, worn, chipped and broken teeth. Inputting new pattern characteristics to the main categories of tool malfunctions, the system successfully classified them even when variations of signal amplitude and ranking of malfunctioned teeth occurred.     

电机真空干燥罐液压系统故障分析排除实例及防治对策

分析并排除电机真空干燥罐液压系统常见的技术故障,制订了防治措施,达到了满意效果.     

An integrated monitoring method to supervise waterjet machining

The paper reports on development, calibration and exploitation of an integrated energy-based monitoring method for waterjet machining. The main advantage of the method resides in its ability to simultaneously monitor the level of output (at nozzle), active (cutting through) and passive (not cutting) waterjet energy thus enabling its budgeting. Relying on multiple acoustic emission sensors, the monitoring solution was implemented on the harsh waterjet environment to detect process malfunctions (e.g. jet penetration, nozzle clogging) and by adjust cutting conditions (e.g. feed speed) to result in improved accuracy and quality of machined surfaces.     

国内空分低温填料精馏塔故障分析

对过去20年国内空分低温填料精馏塔的故障进行了分析,超过70％的故障案例源于液体分布器与填料问题.空分设备企业应加强研发以杜绝填料塔故障.     

多绳摩擦提升机故障分析方法探讨

针对多绳摩擦提升机运行中典型的过卷和打滑故障,根据矿井提升实际运行情况,重点分析了多绳摩擦提升机制动器工作参数及其对提升机过卷与打滑故障的影响,提出了多绳摩擦提升机过卷和打滑故障的主要原因及处置办法。     

问题意识及其培养探究

创新始于＂问题＂,即问题意识是创新思维的关键和前提。从对问题意识的理解着手,阐明问题意识的重要性,分析问题意识薄弱的表现和原因,论述问题意识培养的意义,探讨问题意识培养的有效途径,归纳问题意识培养过程中所存在的问题。     

LUV55/4FQ20-605锅炉强制循环泵电机主要故障及改进措施

阐述了LUV55/4FQ20-605锅炉强制循环泵电机的主要故障及其原因。说明了提高绝缘系统质量,加强运行维护是消除其故障隐患的关键。通过对电机的绕组线、引出线绝缘结构、中性点连接密封绝缘结构进行了改进,降低了电机的电压等级等措施,提高了电机运行可靠性。对电机的日常运行维护提出了建议。