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71.
TC4钛合金全髋关节机械压力机恒载荷精密模锻技术 总被引:3,自引:0,他引:3
本文介绍了机械压力机恒载荷精密模锻技术的原理;研究了TC4钛合金全髋关节的精密模锻技术。经试验验证,采用机械压力机恒载荷精密模锻技术生产的锻件尺寸精度高、表面光洁、锻造流线不外露。符合美国标准ASTM F620与中国医药标准YY0117.1—93的要求。 相似文献
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电镀金刚石砂轮精密修磨天线罩内廓型的工艺参数研究 总被引:1,自引:0,他引:1
由熔融石英材料制造的天线罩属于典型的复杂曲面硬脆材料工件:其内廓型精加工的加工精度要求很高,只能通过专用设备采用电镀金刚石砂轮进行干磨削。本文通过实验,研究了在天线罩CNC修磨机床上磨削天线罩内廓型的工艺参数,确定了磨削加工时的砂轮进给量和工件转速的合理范围,并据此进行了磨削实验验证、结果表明用60#电镀金刚石砂轮转速为10800r/m时,当取进给量,≤0.03mm,工件速度vm≤1mm/s情况下.加工精度和表面质量最好,可以满足天线罩内廓型的精加工要求。 相似文献
74.
针对多缸柴油机机体缸套孔及离合器壳定位销孔精加工中存在的问题。应用经济型数控系统对专用机床实行机、电、液一体化控制的改造。对应用CNC技术精确设定开环控制系统的机械原点。提高传动精度及专用机床加工柔性化的方法进行了研究。 相似文献
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Ultrasonic elliptical vibration cutting of titanium alloy Ti–6Al–4V is investigated in this research. Because products made of Ti–6Al–4V alloy are usually designed for possessing low-rigidity structures or good-quality cut surfaces, machining requirements such as low cutting forces and slow rate of tool wear need to be fulfilled for realization of their precision machining. Therefore, the ultrasonic elliptical vibration cutting is applied as a novel machining method for those products. Machinability of Ti–6Al–4V alloy by the ultrasonic elliptical vibration cutting with cemented carbide tools is examined to figure out suitable cutting conditions for precision machining of Ti–6Al–4V alloy. As experimental results, generated chips, cutting forces, and profiles of cut surfaces are indicated. A forced vibration problem occurred due to the segmented chip formation, which is also well-known in the ordinary non-vibration cutting. Therefore, characteristics of the forced vibration due to the chip segmentation are investigated in this research. Through the experiments, it is found that the frequency and magnitude of the forced vibration have relation with the average uncut chip thickness and cutting width. Especially, it is found that the averaging effect can suppress the forced vibration, i.e. the chip segmentation tends to occur randomly over the large cutting width, and hence the force fluctuations with random phases tend to cancel each other as the cutting width increases relatively against the average uncut chip thickness. Based on the investigations, a new practical strategy to suppress the forced vibration due to chip segmentation is proposed and verified. Using the proposed method significantly decreased cutting forces and good quality of surfaces are obtained when the forced vibration is suppressed compared to the ordinary non-vibration cutting results. Therefore, the results suggest that the precision machining can be realized without sacrificing the machining efficiency by increasing the width of cut and decreasing the average uncut chip thickness. 相似文献
77.
Multiphase flowmeters have an important role to play in the industry and any attempts that lead to improvements in this field are of great interest. In the current study, group method of data handling (GMDH) technique was applied in order to increase measuring precision of a simple photon attenuation based two-phase flowmeter that has the ability to estimate the gas volumetric percentage in a two-phase flow without any dependency to flow regime pattern. The simple photon attenuation based system is comprised of a cobalt-60 radioisotope and only one 25.4 mm × 25.4 mm sodium iodide crystal detector. Four extracted features from recorded photon spectrum in sodium iodide crystal detector were used as the inputs of GMDH neural network. Equations related to the combination of the features and the error rate of each approximation is also reported in this paper. Applying the mentioned technique, the gas volumetric percentage in an oil-gas two phase flow was determined with the root mean square error of less than 2.71 without any dependency to the flow pattern. The obtained measuring precision in this study is at least 2.1 times better than reported in previous studies. 相似文献
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基于田口质量观的机械产品选配方法 总被引:2,自引:0,他引:2
为减少选配后的机械产品由于功能波动而造成的损失,将田口博士提出的质量损失函数运用到机械产品选配活动中。分析Artiles多变量损失函数的局限性,提出基于信噪比(sNR)的多元质量特性损失函数来定量表达零部件多个质量特性的损失权重及损失成本,以及把配合偏差的质量损失函数作为衡量配合精度的有效指标。在综合考虑机械产品多处配合精度与各零部件多元质量特性下,利用整数规划思想,建立面向选配的产品质量损失成本模型(P-QLC),在保证产品质量损失成本最小化的情况下,达到最优选配组合的目的。实例验证该方法的有效性。 相似文献