气缸套半自动珩磨机电气系统的改造

本文介绍大河产MB4215型半自动立式珩磨机电气系统的技术改造，提出了设计应用方案，其目的是降低设备维修率，最大限度的利用该设备提高珩磨平台网纹质量。     

MB4215珩磨机试验平台网纹珩磨

气缸套内孔珩磨平台网纹,要着重考虑四个主要的技术参数:1)网纹沟槽深度,2)网纹沟槽宽度,3)平台面积,4)网纹角度,同时还要求网纹纹路要清晰、无乱纹。对于沟槽深度、宽度、平台面积主要是选用合适的金刚石砂条和选择合适的加工量;对于网纹角度,主要是选择合适的主轴转速及磨头的往复速度;但是要在MB4215珩磨机上获得清晰、无乱纹的平台网纹,则需要采取一些特殊的工艺措施。     

珩磨机改造及珩磨液性能试验

本文叙述了对发动机气缸套平台网纹的加工机床的改造,使其达到优异的性能,珩磨出优质的平台网纹：珩磨液的性能及对珩磨平台网纹磨削的影响。     

卧式珩磨机在偶件生产中的应用

本文从应用的角度阐述了善能公司ＭＢＣ－１８０５、国产ＳＣＹ６０１６两种卧式珩磨机在柱塞套、阀座中孔加工中的状况,介绍了卧珩的优点及其切削机理。通过多年生产实践,摸索出卧珩加工柱塞套及阀座中孔的技术参数、加工质量水平以及与研磨的成本、效率对比。并对机床进行了一些改进;以及对机床的认识、结论等。     

缸套内孔珩磨网纹参数含义的探讨

随着近几年发动机技术的发展，尤其是国家对发动机排放要求的提高，带动了发动机核心摩擦副配件中缸套生产技术的提高，内孔平台珩磨网纹就是其中一个重要的发展趋势。经研究表明：平台珩磨加工出的缸套内孔表面的轮廓曲线形状已非常接近发动机正常工作时的轮廓曲线形状，因此大大缩短了磨合时间，另外工作表面存在一定深度的深沟槽，在发动机工作过程中深沟槽储存的润滑油能及时供给工作表面，重建油膜的速度大于挤出去的速度，保证了发动机工作中油膜的稳定。可以说，     

缸套珩磨平台网纹工艺探讨

内孔经珩磨平台网纹的气缸套,以其理想的储油构造、优良的滑动摩擦性能和良好的经济性,愈来愈被众多的发动机制造厂家所接受。珩磨平台网纹加工工艺作为一项新兴技术已在气缸套行业得到了初步推广和运用。然而,由于珩磨平台网纹是一种二次复合珩磨工艺,工艺过程较为复杂,对加工质量的影响因素较多。反映在批量生产时;内孔表面加工质量不稳定,甚至一只缸套同一横截面内各测点珩磨平台网纹参数值差异很大。为了能稳定生产出合格的珩磨平台网纹缸套和使其加工工艺能适应不同用户的需要,探索其加工过程中平台网纹参数的变化规律,很有必要。1 加工过程中表面轮廓及网纹沟槽形状的变化规律     

干式气缸套平台网纹加工技术

论述气缸套平台网纹表面的优越性能，介绍了干式气缸套平台珩磨加工的关键技术。     

柴油机气缸套内表面平台珩磨网纹技术的探讨

概述了气缸套内表面采用的平台珩磨网纹技术,介绍了国内外概况及国内外平台珩磨网纹技术水平的对照,并进一步陈述了平台珩磨网纹成形的机理.在实际推广于S195、上柴6135、重发NH康明斯、奥地利斯太尔、机车280、机车240C、机车240D等柴油机上,获得了成功.该技术在提高气缸套使用寿命、降低机油消耗量及排放指标方面均有重大意义.     

气缸套内孔磨削加工技术

气缸套是发动机的心脏部件之一，其圆度、圆柱度对密封性、油耗有很大影响，缸套珩磨网纹的分布情况，角度、表面特性对油耗、串气量及磨合期的长短有集中的影响。因此，发达国家对气缸套内孔加工进行了深入研究，发明了许多加工方法，现综述如下：     

平台珩磨网纹Rk参数集及其正确的定义描述

本文介绍了我国内燃机气缸孔平台珩磨网纹表面控制参数的进步过程,分析了多种控制方法及参数的优缺点,指出了GB/T18778.2—2003《产品几何量技术规范(GPS)表面结构轮廓法具有复合加工特征的表面第2部分:用线性化的支承率曲线表征高度特性》的理解难点及表达作者观点的定义描述。     

浅析毛刺缸套铸态纹理表面的控制

本文介绍了什么是毛刺缸套、铸态纹理表面的要求及这种缸套的优点及良好的市场前景.重点分析了毛刺缸套的铸态纹理的控制,对同行业想做这种缸套的客户,具有借鉴意义.     

Improvement options for a former water-driven-mill building now used as a theatre

After investigating the financial feasibility (and so abandoning the idea) of providing self-generated electricity using hydro-power, it was recommended that the top priority should be the direct connection of an electricity supply, from the mains grid to the building; this would cost £8800. Thereby, the theatre would receive a relatively unrestricted supply of electricity at cheaper unit tariffs. This improvement should be followed by the most urgent repairs being carried out to the building fabric, at an estimated cost of £6990. These repairs are necessary to ensure the continued integrity of the building's structure, thereby inhibiting the on-going deterioration.

The energy and financial appraisal also suggested a priority listing of overall improvements to the building in order to achieve a significant, economically justifiable reduction in energy demand; the recommended options are estimated to cost in total £39819. However, the capital cost of such an upgrading would only be recouped, and the theatre achieve a sustainable future, if the building were to be used more intensively and for a wider range of activities than at present in order to increase its revenue significantly.

All prices as stated are those at August 1991.     

X6170ZD-3A柴油机断活塞破缸套问题分析及改进

X6170ZD－3A是新研发的一款大功率闭式循环发电用柴油机,自投放市场以来多次出现活塞从销孔处破裂,气缸套从支承肩处断裂问题。同时,该机型在生产中烟度超出标准要求、呼吸器处窜蓝烟现象较突出,另外燃油消耗率以及排气温度等性能指标也接近技术要求的上限,经常出现难以试车现象,影响生产效率。从活塞的受热面积及机体水腔机构人手,分析X6170ZD－3A柴油机活塞热负荷大的原因,以及缸套、活塞环的冷却情况,寻找问题的根本原因,并结合生产现状提出了改进建议,为尽快解决当前X6170ZD－3A柴油机存在的质量隐患提供一定的参考。     

气缸套安装及断台原因分析

目前气缸套失效模式主要表现为"严重早期磨损"及"支承肩断裂"等两种,为防止此类问题的发生,用户在安装、使用缸套产品前请注意如下几点事项:     

松孔镀铬气缸套在我段东风7D型机车上运用的研究

介绍松孔镀铬气缸套的特点、工艺过程及其在金城江机务段东风7D型机车上的运用效果.与传统的气缸套相比,松孔镀铬气缸套保油性好、耐磨、摩擦系数低;生产工艺简单,适于在机务段内进行;运用效果良好,经济效益和社会效益可观.     

Improvement of thermal management of proton exchange membrane fuel cell stack used for portable devices by integrating the ultrathin vapor chamber

UVC (ultrathin vapor chamber) simultaneously has a high heat-conducting property, excellent temperature uniformity and simple structure. These advantages are very suitable for thermal management of the open-cathode PEMFC (proton exchange membrane fuel cell) stack. In this work, two-type UVCs with different appearances are integrated into a conventional PEMFC stack respectively. The effect of UVC on the output performance, thermal management and operating stability is investigated by the experiment combined with simulation. The results show that UVC can significantly increase the output voltage under high current density. In 35 A, the output voltage of the stack integrated the vertical UVC increases by 20.25% relative to the conventional stack. Thermal management is also improved by UVC. The highest temperature inside the stack decrease by 9 °C in 35 A, and the membrane temperature is decreased obviously. But it still exceeds the optimal operating temperature of open-cathode PEMFC stack due to the poor cooling type in the condensation side of UVC. UVC improves the operation stability of the stack and slows the deteriorative speed of output performance. This work hopes to attract more attention to the application of UVC on the thermal management of portable power sources used open-cathode PEMFC stack.     

活塞环-气缸套纳米润滑油强化传热的机理研究

内燃机活塞环-气缸套之间润滑油膜存在流体润滑、薄膜润滑以及干摩擦状态共存的现象。针对其中的流体润滑状态,采用Euler-Lagrange算法考察了加入纳米颗粒后对基础润滑油传热性能的影响。结果表明,由于纳米颗粒的加入对流场产生扰动,表现为速度边界层减薄,加速了润滑油与壁面热量传递过程,显著提高了润滑油的换热能力。以体积分数为0.5%、1.0%和1.5%、粒径为50nm的金刚石纳米润滑油为例,相对于基础润滑油,平均对流传热系数分别提高了2.5%、5.4%和7.3%。     

微隙技术简介

微隙技术是一项已获得美国专利的高新技术。微隙技术是香港高富动力有限公司资深专家周芝山和周继华先生经过多年精心研究、认真实践的成果。该技术曾在1993年由国家科委列为国家科技成果重点推广项目。1994年向美国专利局申请发明专利,并于1995年12月被批准授与发明专利（专利号码：5476076）,其名称为＂内燃机无隙过盈动配合活塞＂（又称微隙技术）。     

Fracture analysis of hydrogen storage composite cylinders with liner crack accounting for autofrettage effect

An understanding of fracture behavior is crucial to the safe installation and operation of high-pressure composite cylinders for hydrogen storage. This work has developed a comprehensive finite element model to investigate axial surface flaws in cylinder liners using the fracture mechanics and a global–local finite element technique. Since the autofrettage process has a strong influence on cylinder fracture behavior, it is also considered in this analysis. The simulation process is broken down into three steps in order to precisely extract fracture parameters and incorporate the autofrettage effect. In the first step, the global model performs the autofrettage simulation to study the residual stress with consideration of both material hardening and the Bauschinger effect. In the second step, the global model uses residual stress to compute displacement for the local model. Finally, in the third step, the local model extracts the values of stress intensity factor and J-integral. Comparison is conducted on the fracture parameters with various autofrettage levels and crack shapes. The vicinity of the crack front is also studied by the size and shape of the plastic zone, and the validity of stress intensity factor and J-integral dominances is examined.