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设计研制一种用于成形表面接触式在线测量的超精度测量仪.它的优点如下:①测量力很小,(约0.001~0.0015N),对被测表面不会产生划伤、刮痕;②测量精度高,测量仪测头的倾斜与滑动引起的测量误差很小,且其运动通过极小型的激光干涉差分传感器进行检测,因此,其测量数据的相关性和重复性比传统的传感器要好得多,测量数据的重复性3σ小于0.1μm;③可实时进行测量,从测量仪测得的数据通过电脑同步输出,生产效率高. 相似文献
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Twin roll strip casting can be an effective alternative to produce high manganese TWIP steel, which provides extraordinary mechanical properties. In the work presented, 1.5–3 mm thin hot strips with up to 30 wt% manganese were produced directly from the melt and further processed to cold strip. An adapted thermo-mechanical treatment, consisting of cold rolling with or without subsequent annealing, enables to adjust different material states, such as recrystallised or strengthened state, and thus to tailor the mechanical properties. As an example for the superior crash behaviour of high manganese TWIP steels, dynamic crash tests were carried out using cold rolled Fe–29Mn–0.3C steel in different material states. 相似文献
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Heui Jae Pahk Dong Sung Lee Jong Ho Park 《International Journal of Machine Tools and Manufacture》2001,41(1):51
The ultra precision positioning technique has become one of the important parts in the development of precision machines. For positioning systems having a long stroke with ultra precision, a combined system including a global stage (coarse stage) and a micro stage (fine stage) is designed in this paper. A ball screw based servo motor is used as the global stage and a piezo actuator as the micro stage, in which some design parameters are analysed. To improve positional accuracy and remove the noise components of motion, the digital Chebyshev filter has been designed and implemented. The implemented digital filter has been found to improve accuracy by as much as three times. Positional accuracy has been readily achieved within 10 nm over the typical 200 mm stroke, and therefore this technique can be applied to develop high precision semiconductor equipment such as lithography steppers and probers. 相似文献
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Development of an on-machine profile measurement system in ELID grinding for machining aspheric surface with software compensation 总被引:6,自引:0,他引:6
M. Sazedur Rahman T. Saleh H.S. Lim S.M. Son M. Rahman 《International Journal of Machine Tools and Manufacture》2008,48(7-8):887-895
Efficient manufacture of dimensionally accurate optical surface on hard and brittle materials is a major concern for optoelectronic industry. Electrolytic in process dressing (ELID) grinding is proved as a reliable process to achieve this optical quality nano-surface finish on hard and brittle materials. Besides surface finish it is important to ensure dimensional accuracy by improving profile and form accuracy of the ground aspheric surface. Kinematic factors are commonly considered the reasons for the dimensional inaccuracy in a machined part. Software compensation is a direct and economical method to overcome several kinematic factors and improve the dimensional accuracy. Last, but most important, is the monitoring of achieved surface profile to ensure more accurate profile radius in the finished part. So an on-machine profile measurement system based on coordinate measuring machine (CMM) principle has been developed to check the profile radius of the ground surface. In this study software compensation was applied in ELID grinding of an aspheric surface in order to compensate the wheel wear until the measured surface profile machined on BK7 glass reaches within tolerable limit. 相似文献
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Shun-Tong Chen Zong-Han Jiang Yi-Ying Wu Hong-Ye Yang 《International Journal of Machine Tools and Manufacture》2011,51(2):95-103
This study presents the development of a grinding-drilling technique for an innovative bench-top drill that combines micro-EDM with grinding and drilling to fabricate micro-holes in optical grade glass. Firstly, a novel diamond-tool, made with copper-based sintered alloy, is designed and fabricated on-line into a harbor-shaped structure with a hollow shaft and negative back rake-angles. Constructed reverse co-centric micro-hole EDM-drilling and reverse w-EDM facilitate on-line machining of the diamond-tool, which can then be directly utilized to drill micro-holes in optical glass and quartz. Application of a load-cell that detects the drilling force in real-time, providing feedback for fine tuning the feed-rate of the tool is proposed. Experimental results show that excellent geometric and dimensional accuracy of micro-holes can be achieved. The estimated reasonable tool life is determined at a machining number of 30 times. The proposed grinding-drilling technique is simple, cost effective, and can significantly contribute to the precision micromachining industry. 相似文献
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Jooho Hwang Chun-Hong Park Wei Gao Seung-Woo Kim 《International Journal of Machine Tools and Manufacture》2007,47(7-8):1053-1058
This paper describes a three-probe system that can be used to measure the parallelism and straightness of a pair of rails simultaneously. The parallelism is measured using a modified reversal method, while the straightness is measured using a sequential two-point method. The measurement algorithms were analyzed numerically using a pair of functionally defined rails to validate the three-probe system. Tests were also performed on a pair of straightedge rails with a length of 250 mm and a maximum straightness deviation of 0.05 μm, as certified by the supplier. The experimental results demonstrated that the parallelism measurement algorithm had a cancellation effect on the probe stage motion error. They also confirmed that the proposed system could measure the slope of a pair of rails with an accuracy of about 0.06 μrad. Therefore, by combining this technique with a sequential differential method to measure the straightness of the rails simultaneously, the surface profiles can be determined accurately and the stage error eliminated. The measured straightness deviation of each straightedge was less than 0.05 μm, consistent with the certified value. 相似文献
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Medical screws are a common mass-produced implantable medical component made of Titanium. To machine the threads of these types of components, thread whirling with carbide tools is typically used. However, tool wear and low cutting speed limit the productivity and increase the manufacturing cost of such medical parts. In this study, a direct motor driven thread whirling unit for an advanced Swiss-type CNC lathe was developed and it was used with advanced tool materials such as low binder content Cubic boron nitride (CBN) and Polycrystalline diamond (PCD) to find a cost-effective and more productive alternative to carbide tools. 相似文献
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C. Scheffer H. Kratz P. S. Heyns F. Klocke 《International Journal of Machine Tools and Manufacture》2003,43(10):76
This paper describes an in-depth study on the development of a system for monitoring tool wear in hard turning. Hard turning is used in the manufacturing industry as an economic alternative to grinding, but the reliability of hard turning processes is often unpredictable. One of the main factors affecting the reliability of hard turning is tool wear. Conventional wear-monitoring systems for turning operations cannot be used for monitoring tools used in hard turning because a conglomeration of phenomena, such as chip formation, tool wear and surface finish during hard turning, exhibits unique behavior not found in regular turning operations. In this study, various aspects associated with hard turning were investigated with the aim of designing an accurate tool wear-monitoring system for hard turning. The findings of the investigation showed that the best method to monitor tool wear during hard turning would be by means of force-based monitoring with an Artificial Intelligence (AI) model. The novel formulation of the proposed AI model enables it to provide an accurate solution for monitoring crater and flank wear during hard turning. The suggested wear-monitoring system is simple and flexible enough for online implementation, which will allow more reliable hard turning in industry. 相似文献
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Chloride‐induced damage of reinforcing steel is especially for parking garages and bridges often very severe as large amounts of chlorides act on horizontal surfaces which could lead to fast ingress of these detrimental ions up to the level of the reinforcement and subsequently to high rates of corrosion. In order to avoid the disadvantages of conventional rehabilitation (unreliable prognosis with patch repair or high costs and regular maintenance with cathodic protection using impressed current) a new combined protection system was developed where the principle of drying out the concrete (by means of a surface protection system) is combined with a temporary cathodic protection (by means of a sprayed zinc layer) during the transitional period of the drying out process. This new system was tested both in the laboratory and on‐site at a pilot application. Based on the results obtained the possibilities and limitations of the new system are discussed in this paper. 相似文献
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The disassembly of used goods is characterized by strongly varying quantities and a wide range of different kinds and states of products. Furthermore, the requirements of a disassembly system are determined by the disassembly object, by the process as well as by the disassembly system itself. As a result of the high labor costs in industrial countries and the huge amount of used goods, an automated disassembly is favored for the industrial disassembly. New methods for the programming of industrial robots have to be developed because the costs for a programming of small lot sizes are a key factor of the economic efficiency of small and medium sized enterprises (SME). In this paper an off-line programming environment for programming of industrial robots in the field of automated disassembly is presented. The exemplary implementation is realized at a pilot disassembly system, which was built up at the Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) of the Technische Universität Berlin. 相似文献
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漏磁检测是目前最常用的管道缺陷检测方法之一,它针对管道壁变薄、有腐蚀或者凹坑等缺陷有很好的检测效果。漏磁检测系统通常分为管内检测、管外定位、数据处理三个部分,其中地面标记器是管外定位的核心设备。文章根据油气管道漏磁检测的实际需要,研制出一种操作简洁、定位精度高的地面标记器。在对地面标记器的工作特性和性能要求进行较全面分析的基础上,完成了地面标记器系统的硬件电路设计和制作,其中包括充电电路、供电电路、信号调理电路和MCU控制电路;完成了数据采集和计时程序的编写,并进行了试验验证。试验结果表明,标记器能够有效监测到强度相当于地表以下3m处的管道中经过的检测机器人发出的漏磁信号。 相似文献