电火花内圆磨削伺服阀阀套及表面质量分析

主要论述电火花内圆磨削加工的机理、加工特点,并通过实验和使用所取得的数据,较全面地分析了电火花内圆磨削加工阀套内孔、内环槽的电参数对表面质量的影响。     

砂轮浸石墨溶液处理效果显著

据四三○厂访英报告称,英国工厂中砂轮常采用浸石墨处理,效果很好。因此,我们也作了浸石墨试验,并先后在刃具磨床、内圆磨床、螺旋刃具磨床、车刀磨床、丝锥铲背磨床、拉刀磨床上进行了广泛的磨削试验,收到了显著效果,得到磨工的普遍欢迎。我们还对     

电火花磨床成型加工工艺研究

通过对专用于航空发动机蜂窝加工的电火花蜂窝磨床的功能开发和工艺研究,实现对环形件外型面的电火花成型加工。该方法是一种独创的新型加工工艺,突破了传统电火花磨床只能磨削加工环形蜂窝件内径的束缚,实现了实体工件外型面低成本、高效能的大余量去除和成型加工,有效地解决了难加工材料、特殊结构表面余量去除困难,刀具悬臂梁加工振动大,刀具损耗大的技术难题。     

在内圆磨床上成批加工坐标孔

在精密机械产品中,表面硬度高、又有位置度要求的坐标孔,常规方法是热处理后在坐标磨床上进行加工。但坐标磨床价格昂贵,也不适合批生产要求,且许多工厂尚无此种设备。 我们在生产一种液压伺服阀时,就遇到如图1所示的一组孔。其表面渗碳淬火后硬度为HRC55～60。我厂无坐标磨床,只得在普通内圆磨床上加工。     

达诺巴特集团外圆磨床系列

达诺巴特集团生产的外圆磨床系列专门应用于航空航天领域.设备配置高刚性组件,在一次装卡条件下完成高精度外圆、内圆和端面磨削.     

三相变流机定子内孔加工的探索

探讨了形状较复杂的薄壁零组件的切削加工；三立往夹具的设计、制造、使用与加工件的质量问题．以及内圆磨床的改造利用，指出了抽风设备在磨削加工中的作用．     

谈谈内圆磨具的润滑

磨床上的内圆磨具,一般多采用滚动轴承结构。如M131W、MG1432A等,就是在内圆磨具的套筒两端各安装一对精密向心推力轴承。通常使用的内圆磨具主轴转速在10000～20000转/分之间。怎样使高速旋转的主轴系统保持噪音小、寿命长以及足够的刚性,滚动轴承的润滑是个主要问题,     

磨削解决方案还得斯来福临

斯来福临集团的磨削设备和磨削方案 受到很多用户的关注斯来福临集团由多个知名厂家组成,拥有多种名牌产品,不但有很多能适合批量生产的数控磨床、数控专用磨床,而且还有许多优质的数控复合磨床、高效专用数控磨床、精密数控磨床。使用斯来福临精密磨床,零件在一次装卡下可以完成内圆、端面和外圆加工,效率高、精度好。在加工技术方面,斯来福临的技术研究人员已对高速加工的机理、机床机构、机床刚性及精度的影响等方面有系列的研究。多轴加工技术,已被广泛地应用于各种类型的磨床上,并且     

沟槽节流动静压轴承在内圆磨具上的应用

产品YB20的转子内孔和端面要求光洁度▽9、椭圆度0.003毫米。原有M2110内圆磨床加工产品只能达到光洁度▽7、椭圆度0.007毫米,磨头是滚动轴承的,不能满足产品要求。为此,对磨头进行改装。考虑如采用小孔节流结构,由于转速高、温升大,不能保证磨头精度。     

电火花加工最新技术进展

介绍了近年来日本电火花加工研究的最新进展 ,其中包括弯曲孔电火花加工 ,液中放电表面改性处理 ,绝缘陶瓷电火花加工 ,单次放电微细电极加工 ,放电堆积造型加工 ,气体中放电电火花加工 ,扫描创成电火花加工 ,钛合金电火花线切割表面着色及反复拷贝法微细电极电火花加工等电火花加工最新技术 ,可为我国的电加工研究提供借鉴     

叶片型面砂带磨削技术的现状和发展趋势

叙述了国内外叶片型面砂带磨削的各种技术,分析了一些叶片材料的砂带磨削性能,并介绍了一些典型的叶片砂带磨床.     

Modelling of grinding mechanics: A review

Grinding is one of the most widely used material removal methods at the end of many process chains. Grinding force is related to almost all grinding parameters, which has a great influence on material removal rate, dimensional and shape accuracy, surface and subsurface integrity, thermodynamics, dynamics, wheel durability, and machining system deformation. Considering that grinding force is related to almost all grinding parameters, grinding force can be used to detect grinding wheel wear, energy calculation, chatter suppression, force control and grinding process simulation. Accurate prediction of grinding forces is important for optimizing grinding parameters and the structure of grinding machines and fixtures. Although there are substantial research papers on grinding mechanics, a comprehensive review on the modeling of grinding mechanics is still absent from the literature. To fill this gap, this work reviews and introduces theoretical methods and applications of mechanics in grinding from the aspects of modeling principles, limitations and possible future trendencies.     

基于LabVIEW的超精密磨床嵌入式监控系统

针对超精密磨削机床的监控需求,基于NI–sbRIO硬件平台开发了一套应用于超精密磨床状态监测和数据采集的嵌入式监控系统,使用FPGA对温度、振动、声发射等信息进行实时数据采集,并使用实时处理器对数据进行分析和处理,实现对机床的实时状态监测和数据存储。通过FPGA编程取代硬件数据采集卡,成本低,灵活性强。试验表明,该系统能够胜任超精密磨床的监控任务。     

Thermomechanical coupling effect on characteristics of oxide film during ultrasonic vibration-assisted ELID grinding ZTA ceramics

Ultrasonic vibration-assisted ELID (UVA-ELID) grinding is utilized as a novel and highly efficient processing method for hard and brittle materials such as ceramics. In this study, the UVA-ELID grinding ZTA ceramics is employed to investigate the influence of thermomechanical loading on the characteristics of oxide film. Based on the fracture mechanics of material, the model of internal stress for oxide film damage is proposed. The thermomechanical loading is composed of mechanical force and the thermal stress generating from grinding temperature. The theoretical model is established for the mechanical force, thermal stress and internal stress respectively. Then the finite element analysis method is used to simulate the theoretical model. The mechanical force and grinding temperature is measured during the actual grinding test. During the grinding process, the effect of grinding wheel speed and grinding depth on the thermomechanical force and the characteristics of oxide film is analyzed. Compared with the conventional ELID (C-ELID) grinding, the mechanical force decreased by 25.6% and 22.4% with the increase of grinding wheel speed and grinding depth respectively, and the grinding temperature declined by 10.7% and 12.8% during the UVA-ELID grinding. The thermal stress in the latter decreased by 16.3% and 20.8% respectively, and internal stress reduced by 12.3% and 15.6%. It was experimentally found that the topographies of oxide layer on the surface of the wheel and the machined surface in the latter was better than that in the former. The results indicate that the action of ultrasonic vibration establish a significant effect on the processing. Subsequently, it should be well considered for future reference when processing the ZTA ceramics.     

Suppression of Surface Burn in Grinding of Titanium Alloy TC4 Using a Self-inhaling Internal Cooling Wheel

Based on analysis of surface average temperature and burn degree, this article obtains the threshold temperature of surface burn in grinding titanium alloy with cup wheels. Meanwhile, the impact of the burn degree on the metallographic structure of workpiece surface and metallurgical phase transformations is investigated. In order to reduce the grinding temperature and improve the grinding efficiency, a self-inhaling structure cup segmented wheel is developed to generate internal cooling effect. The internal cooling technology is compared with traditional cooling conditions in the grinding experiments on TC4 (Ti-6Al-4V). The results indicate that the self-inhaling internal cooling wheel can reduce the grinding surface temperature by 30% or more, and the grinding efficiency doubles. Utilizing water-based semi-synthetic coolant, the segmented wheel with the self-inhaling structure can further reduce the grinding temperature by about 50%.     

Design and experimental study of a micro-groove grinding wheel with spray cooling effect

The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl- shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200℃, which means the developed grinding wheel makes cooling high efficient and low energy consuming.     

Peculiarities of Mixture Formation and Ignition of the Fuel Mixture in the Metal Sprayer Chamber

The paper presents a device for spraying the low-melting metal coating, based on the rocket chamber operation principle. The design of the fuel nozzle, pre-mixing chamber, and radial combustion chamber is considered. The processes of electro-spark ignition of the fuel mixture and the flame front stabilization are described. The choice of the critical section area as a place of the coating material feeding in the high-temperature combustion products flow is substantiated.     

AHPSO-SVM预测超声内圆磨削ZTA陶瓷的边界损伤

为解决普通加工方式易出现工程陶瓷边缘碎裂的问题,本文对超声内圆磨削工程陶瓷边界损伤预测系统进行了研究。在35 kHz轴向超声磨削与普通磨削两种条件下独立进行试验,运用支持向量机研究工艺参数与边界损伤影响规律,采用改进的粒子群算法优化支持向量机,建立采用混合核函数的AHPSO-SVM预测模型。研究结果表明,超声激励下试件边界损伤降幅为10.05%～21.23%,AHPSO-SVM预测模型MSE为0.378 4、平均相对误差为1.369 0%、30次适应度值标准差为0.020 2。相比于普通磨削,超声磨削可使ZTA陶瓷边界损伤值显著降低;建立的AHPSO-SVM模型具有较好的学习能力、泛化性能与良好的稳定性。     

Interference and grinding characteristics in ultra-precision grinding of thin-walled complex structural component using a ball-end grinding wheel

As for ultra-precision grinding of difficult-to-process thin-walled complex components with ball-end grinding wheels, interference is easy to occur. According to screw theory and grinding kinematics, a mathematical model is established to investigate the interference and grinding characteristics of the ball-end wheel. The relationship between grinding wheel inclination angle, C axis rotation angle, grinding position angle and grinding wheel wear are analyzed. As the grinding wheel inclination angle increases, the C axis rotatable range decreases and the grinding position angle increases. The grinding position angle and wheel radius wear show a negative correlation with the C axis rotation angle. Therefore, a trajectory planning criteria for increasing grinding speed as much as possible under the premise of avoiding interference is proposed to design the grinding trajectory. Then grinding point distribution on the ball-end wheel is calculated, and the grinding characteristics, grinding speed and maximum undeformed chip thickness, are investigated. Finally, a complex structural component can be ground without interference, and surface roughness and profile accuracy are improved to 40.2 nm and 0.399 μm, compared with 556 nm and 3.427 μm before ultra-precision grinding. The mathematical model can provide theoretical guidance for the analysis of interference and grinding characteristics in complex components grinding to improve its grinding quality.