防锈切削冷却液

介绍两种冷却液。一种为:聚氧乙烯山梨醇油酸脂—26％;三乙醇油酸皂—30％;亚硝酸钠—10％;聚乙二醇—10％;10~#机油—30％。另一种为:三乙醇胺—0.089％;亚硝酸钠—0.331％;聚乙二醇—0.044％;水——余量。第一种防銹切削冷却液防銹性好,润滑冷却性能和稳定性较好,使用方便,适用于轴承的磨加工、车加工和其它行业的金加工。第二种冷却液防銹性和冷却性能好,质量较稳定,用于切削量小的精磨工件上。但是由于润滑性能较差,不能用于切削量大的机床上加工产品。     

重负荷冷却液后市场测试工具选用的研究

基于柴油机后市场对冷却液检测工具的需求,本文介绍了重负荷冷却液pH、冰点、亚硝酸盐含量等因素对重负荷冷却液的影响,并针对这些参数选用了相关的检测工具,介绍了各种检测工具的检测原理,使用检测工具对冷却液参数进行了测试和结果对比,对于后市场选用冷却液相关检测工具提供了参考,试验表明,试纸对于冷却液pH和亚硝酸盐的测量有一定的局限性,pH计和亚硝酸盐检测仪不受冷却液颜色影响,检测更准确。     

发动机冷却液的监测

简要介绍了发动机冷却液的组成、分类和发动机冷却液监测的内容，并用案例说明了冷却液监测的意义和方法。     

用于磨削加工的冷却液导流装置

磨削加工中 ,由于砂轮高速旋转时产生的气流阻碍了冷却液流入工作界面 ,或在修整砂轮时不能有效地清洁砂轮表面 ,因而会使磨削效率降低 ,并增加砂轮的损耗 ,磨耗比 G低 (工件磨除量与砂轮损耗之比值 )。为此 ,研制了如图 1所示的冷却液导流装置。图 1　磨削导流装置示意图导流装置由多块挡板组成 ,能形成一个冷却液腔 ,在挡板上开有冷却液入口和出口。工作时 ,通过压力为 2 .1 MPa的冷却液泵驱动冷却液进入导流装置 ,冷却液从挡板顶部的入口不断进入冷却液腔 ,然后 ,液腔中的冷却液从冷却液出口流出来 ,不断地向砂轮表面供给冷却液。该导…     

缓进给强力磨削冷却液的研制与探讨

前言 根据我国燃气轮机生产发展的需要,1977年我所进行了In-738合金缓进给强力磨削用冷却液的研制,现将一年来的试验结果介绍如下。 一、试验的冷却液材料 根据叶片材料、缓进给强力磨削的特点,要求采用冷却及清洗性强、磨削效能高的冷却液。合成冷却液或半合成冷却液是冷却性能较强的水基冷却液。其清洗性能可利用加入的表面活性剂来改善。冷却液的磨削效能表现在磨削比的提高,磨削功率的减少,和防止表面缺陷(烧伤,波纹)的产生。研究了添加减摩剂和极压剂的配方材料,配成透明或半透明的合成冷却液,其配方见表1～2。 试验冷却液的评价指标 …     

2种电子设备低冰点冷却液对比研究

为了探明导电的65号冷却液(冰点为-65℃的乙二醇水溶液)和绝缘的PAO(Poly-Alpha-Olefin,聚阿尔法烯烃)冷却液在电子设备冷却中的优缺点,对上述2种冷却液的热物性参数进行了比较,并采用CFD软件对上述2种冷却液应用在某一电子设备冷板中的热性能进行了仿真研究。结果表明,无论是在相同体积流量条件下,还是在相同质量流量的条件下,PAO作为冷却液时在热学性能方面表现均不如65号冷却液,仅在对冷却液的绝缘性能要求高、而对热学性能要求不高的场合下,PAO冷却液具有一定的优势。     

干切割——一个亟需解决的课题

环境保护的立法,日益逼近机械加工中所使用的冷却液.限制冷却液雾化污染,按冷却液种类将冷却液和附有冷却液的切屑当作有毒物质进行善后处理,是冷却液使用者应尽的义务.冷却液一旦流出工厂,就会极大地增加处理难度,殃及环境,成为潜在的隐患.因此,与破坏臭氧层的元凶CFC(含氯氟烃)问题一样,冷却液问题也是所有制造企业无法回避的.     

BTA深孔钻喉部结构的数值优化研究

针对深孔切削加工进行时,排屑效率低与钻头喉部易堵屑的问题,对BTA冷却系统冷却液出口断面速度,以及冷却液在钻头喉部的流动过程与特性进行了研究,基于计算流体动力学(CFD)与射流卷吸效应,提出了一种新型的BTA深孔钻头喉部结构。对加工时的压强和流量参数进行了分析后,修订了有限元冷却液模型的湍流强度和耗散速率,在此基础上进行了两种钻头喉部结构的排屑能力对比试验,测量了冷却液系统的冷却液出口断面流出平均速度。研究结果表明:实验时,新型喉部结构的直径38 mm BTA深孔钻头所组成的冷却系统,其冷却液出口断面流出的平均速度提高12.6%;同时,冷却液系统整体的排屑能力也得到了提高。     

介绍几款新型刀具冷却技术

肯纳金属公司推出的BeyondBlast冷却液控制系统2010年,肯纳金属通过2010年国际制造技术展览会推出独一无二的Beyond BLAST TM产品.通过在铣刀刀体和刀片的结合部位开冷却液槽,使冷却液从切屑下部通过刀片内部喷出,将冷却液通过刀片直接输送到切屑根部,是目前已知的最接近加工区域的高压冷却方法,保证了冷却液的有效传输.     

冷却液的生态问题

预计,在不久将来,机械加工的生产率至少提高2倍。这样,选择最佳冷却液具有特别重大意义,并且引出环境污染问题。在机械加工过程中,经常要更换冷却液,大约有30％的冷却液经使用后,将会消失或蒸发掉,因而对周围环境造成生态危险。传统采用的冷却液会导致皮肤病,冷却液蒸汽被吸入呼吸道和肺部后可能引起危险病,其中包括肿瘤病。美国General Motors汽车公司对不同程度受到冷却液悬浮微粒作用的工人,进行了专门的综合调查。其中,1042人是经常与一种类型冷却液(矿物油、乳浊液或合成冷却液)接触的金属切削机床操作工,而769人是不直接接触冷却液的装配工,还调查了从未在机床上工作过的239人。研究了患呼吸系统病的普遍性(一般鼻炎、咳嗽、呼吸困难、慢性支气管炎)。     

Study on recycling of waste water from spent water-soluble coolant

We propose a recycling system that can recover the useful water from the spent water soluble coolant by using a surfactant and powdered activated carbon. The processing of about 70 liters of actual spent water soluble coolant yielded about 60 liters of clear water with 6.7 of pH and 0.0 of Brix value. About 120 liters of recycle water-soluble coolant was prepared by diluting an emulsion type cutting fluid 20 times with the recycle water. The recycle coolant has been showing the very similar Brix value and pH changes as those of virgin coolant until 100 days usage. The recycle coolant also showed the same potential to inhibit the progress of flank wear as that of virgin coolant. These facts indicate that the recycled water can be utilized as a dilutor of renewal water-soluble coolant.     

Study of reasons of increased active force using coolant with uncut chip thickness

The use of coolant usually leads to a decrease in active force. However, it is well known that when cutting with small uncut chip thickness while using a coolant, the active force may be greater than when cutting without a coolant. For this reason, finish turning with very small uncut chip thickness and manual scraping is carried out without a coolant. The current explanation of this phenomenon is that the coolant increases the plowing force. The aim of this research is to study the impact of the coolant on the plowing force and to explain the reasons for the increase in active force at small uncut chip thickness. In the chipping process, a new reason was found that explains the increase in the active force when using coolant. It was established that the coolant prevents the buildup. Due to this phenomenon, cutting is performed with the radius of the cutting tool at a negative rake angle and with greater active force than when cutting without a coolant. When cutting without a coolant, a buildup is formed on the radius of the cutting tool; the geometry of the cutting part is improved. This is the real reason for decrease in active force when cutting without a coolant. When using the method of extrapolation on a zero uncut chip thickness under the same conditions without buildup, it was found that using a coolant does not increase, but decrease the plowing force.     

Analysis of cutting properties with reference to amount of coolant used in an environment-conscious turning process

In the recent years, environmentally conscious design and manufacturing technologies have attracted considerable attention. The coolants, lubricants, solvents, metallic chips and discarded tools from manufacturing operations will harm our environment and the earth’s ecosystem. In the present work, the Tukey method of multiple comparisons is used to select the minimum level of coolant required in a turning process. The amount of coolant is varied in 270 designed experiments and the parameters cutting temperature, surface roughness, and specific cutting energy are carefully evaluated. The effects of coolant mix ratio as well as the amount of coolant on the turning process are studied in the present work. The cutting temperature and surface roughness for different quantity of coolant are investigated by analysis of variance (ANOVA)-test and a multiple comparison method. ANOVA-test results signify that the average tool temperature and surface roughness depend on the amount of coolant. Based on Tukey’s Honestly Significant Difference (HSD) method, one of the multiple comparison methods, the minimum level of coolant is 1.0 L/min with 2% mix ratio in the aspect of controlling tool temperature. F-test concludes that the amount of coolant used does not have any significant effect on specific cutting energy. Finally, Tukey method ascertains that 0.5 L/min with 6% mix ratio is the minimum level of coolant required in turning process without any serious degradation of the surface finish. Considering all aspects of cutting, the minimum coolant required is 1.0 L/min with 6% mix ratio. It is merely half the coolant currently used i.e. 2.0 L/min with 10% mix ratio. Minimal use of coolant not only economically desirable for reducing manufacturing cost but also it imparts fewer hazards to human health. Also, sparing use of coolant will eventually transform the turning process into a more environment-conscious manufacturing process.     

Effect of High-Pressure Coolant Supplies when Machining Nickel-Base,Inconel 718, Alloy with Ceramic Tools

Chip breakability is significantly improved with the use of high pressure coolant supply. This is a result of the reduction in the tool-chip contact length during machining as the coolant under high pressure lifts the chip up after passing the deformation zone. Increasing the coolant pressure results in shorter ceramic tool life when machining Inconel 718 suggesting that the high pressure coolant supply reduces temperature at the cutting zone below a critical level where ceramic tools can perform satisfactorily. The inadequate fracture toughness of ceramic tools makes them more susceptible to failure by mechanical action such as notching at the depth of cut line and premature fracture. The notch wear rate increases with higher coolant supply pressure due to significant erosion of the tool material by the high pressure coolant jet. This mechanically related failure mode occurs on a random basis leading to inconsistency in tool performance, accelerated by fluctuations in thermal and mechanical properties when machining under high pressure coolant supplies.     

虚拟切削加工过程中冷却液三维模拟仿真技术研究

通过对冷却液进行分类、归纳总结，建立其类的数据结构，描述其性质和行为，并对流动过程中的相关因素进行分析，建立冷却液流动过程中合理的数学模型，对虚拟车削加工中的冷却液进行了动态模拟，描述了不同冷却液的真实形态，为虚拟加工仿真环境的构建增加了功能模块。此外，对冷却液与零件、刀具、床身等的碰撞也进行了深入分析与描述，达到了喷溅效果，从而为虚拟制造提供了技术支撑。     

Finish Machining of Nickel-Base Inconel 718 Alloy with Coated Carbide Tool under Conventional and High-Pressure Coolant Supplies

Single-point turning of Inconel 718 alloy with commercially available Physical Vapour Deposition (PVD)-coated carbide tools under conventional and high-pressure coolant supplies up to 20.3 MPa was carried out. Tool life, surface roughness (Ra), tool wear, and component forces were recorded and analyzed. The test results show that acceptable surface finish and improved tool life can be achieved when machining Inconel 718 with high coolant pressures. The highest improvement in tool life (349%) was achieved when machining with 11 MPa coolant supply pressure at higher speed conditions of 60 m · min^?1. Machining with coolant pressures in excess of 11 MPa at cutting speeds up to 40 m · min^?1 lowered tool life more than when machining under conventional coolant flow at a feed rate of 0.1 mm · rev^?1. This suggests that there is a critical coolant pressure under which the cutting tools performed better under high-pressure coolant supplies.

Cutting forces increased with increasing cutting speed due probably to reactive forces introduced by the high-pressure coolant jet. Tool wear/wear rate increased gradually with prolonged machining with high coolant pressures due to improved coolant access to the cutting interface, hence lowering cutting temperature. Nose wear was the dominant tool failure mode when machining with coated carbide tools due probably to a reduction in the chip-tool and tool-workpiece contact length/area.     

Effect of High-Pressure Coolant on Machining Performance

Machining of hardened steel and other difficult-to-cut materials requires instant heat transfer from the cutting edge of the tool to improve tool life. Supply of high-volume and high-pressure coolant often provides the best answer. This paper deals with an experimental investigation on the effect of high-pressure coolant on workpiece hardness, comparing it with dry cut and conventional coolant. The effectiveness of high-pressure coolant is evaluated in terms of improvement of surface finish, reduction in tool wear and cutting forces, and control of chip shape. It is found that the cutting force is reduced, surface finish improved, and chip width is reduced with the use of high-pressure coolant.     

大型有源相控阵雷达阵面管网仿真及优化

采用一维流体仿真分析软件对大型有源相控阵雷达阵面的液冷管网系统进行了仿真分析及优化。首先建立管网模型,利用试验数据确定阻力元件的性能参数,对阵面管网进行了仿真分析,计算得出在额定流量下,各种管径对流量分配差异的影响,从而确定管网的最佳管径。同时,也得出了管网的阻力特性。通过管网的仿真及优化,可释放液冷系统研发风险,节约研发成本,其优化方法和优化结果对其他阵面管网设计也可起到重要的指导作用。     

波纹结构对纵向波纹隔热屏冷却特性影响的数值研究

针对冲压发动机燃烧室纵向波纹隔热屏热防护技术，通过改变波纹的几何结构，开展了隔热屏近壁流场结构调控的研究，采用数值模拟获得了波形对纵向波纹隔热屏流场结构和冷却特性的影响规律。研究结果表明，增加单周期内的冷流迎风侧长度占比更有利于冷流动压进气，充分利用火焰筒内外压差，同时减小了入射冷气流与热流的夹角，减小近壁卷吸涡尺度，降低近壁区的湍流强度，削弱冷、热流掺混，显著增强波谷冷气对下游波峰的保护作用；随着迎风侧长度占比增加，隔热屏的平均综合冷效显著提高。     

AP1000反应堆冷却剂泵“3s供电”问题分析

针对AP1000核电技术中反应堆冷却剂泵因所采用的屏蔽泵转动惯量小、泵的惰走时间短,在汽轮机跳机后,如何保持反应堆冷却剂泵电机3s供电时间的问题,结合AP1000核电厂系统固有特点,分析了“孤岛运行”、“机组满功率运行”、“机组满功率运行＋ 500 kV外电网失去”、“机组满功率运行＋外电网失去”4种极限工况特点.根据电网稳定性和堆芯偏离核态沸腾仿真结果,分析了汽轮机跳机后的电气系统响应和反应堆冷却剂系统响应.研究结果表明,在汽轮机跳机后系统能满足反应堆冷却剂泵3s供电时间要求,以增加冷却剂强迫循环时间,实现安全停堆.