共查询到20条相似文献,搜索用时 281 毫秒
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严伟麟 《机械工人(冷加工)》1982,(12)
我厂在固体激光器的生产中,经常遇到加工各种形状和尺寸的椭圆腔体,其材料为黄铜,表面光洁度要求达10。为此,设计制造了一种压光椭圆孔螺旋拉刀。通过使用证明,该刀具具有振动小,工作平稳、加工精度高、光洁度好(可达9~12)、生产效率高、制造简单等特点。刀具结构及参数的确定: 刀具共分两把,粗拉刀用于拉出预加工椭圆孔,担负主要余量的切削加工;精加工拉刀用于压光,保证加工孔的几何精度和光洁度。压光拉刀加工余量一般取0.06~0.2毫米,由于工件产生弹性变形,使孔径收缩,因此,拉刀直径应大于被加工孔的直径,其拉刀长轴2Amax=2 amax δ、短轴2Bmax=2bmax δ。式中:2a-工件的长轴、2b-工件的短轴、δ-工件 相似文献
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于传信 《机械工人(冷加工)》1993,(1):13-13
过去用普通轮切式等齿距圆拉刀拉削齿轮内孔工件,经常产生挖刀、环状痕迹、波纹、喇叭口、鱼鳞斑点等缺陷,质量不易保证。针对这个问题,我们试验用轮切式不等齿距圆拉刀,并对其部分修改补充,实践证明,改进后的轮切式不等齿距圆拉刀是加工齿轮内孔比较理想的刀具。如图1所示,轮切式不等齿距圆拉刀主要是对普通圆拉刀容易造成摆动的结构进行了改进,其结构特点是: 相似文献
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圆拉刀设计时常因拉削余量、齿升量、齿形和分屑槽等参数选用不当,而使拉刀使用寿命降低、工件表面质量变差、拉刀长度增加和制造成本提高。分析了产生这些问题的原因,指出了一些刀具设计资料中某些数据欠妥之处,并提出了相应的修改建议。 相似文献
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圆拉刀设计时常因拉削余量、齿升量、齿形和分屑槽等参数选用不当,而使拉刀使用寿命降低、工件表面质量变差、拉刀长度增加和制造成本提高。分析了产生这些问题的原因,提出了一些刀具设计资料中某些数据欠妥之处,并提出了相应的修改建议。 相似文献
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矩形花键拉刀是拉削内花键的拉刀。按所加工花键定心方式的不同,有大径定心的内花键和小径定心的内花键两种形式。上述两种形式的花键拉刀均可带有拉削圆孔和倒角的刀齿。根据工件被加工表面要求的不同,矩形花键拉刀的刀齿配置也不同,加工内花键的花键刀齿是最基本的刀齿,根据需要,可配置倒角刀齿,对内花键进行倒角;有时为了提高内花键大、小径的同轴度可配置圆孔刀齿。根据一把拉刀配置的刀齿形式不同,矩形花键拉刀也有不同的形式,有仅仅拉削花键的矩形花键拉刀,也有拉削圆孔—花键、倒角—花键、倒角—圆孔—花键等各种型式的复合矩形花键拉刀。当然各种花键拉刀刀齿的排列顺序也会有不同,由于刀齿排列顺序的不同,拉刀的制造和对拉削工件的表面质量也会存在不同。下面就从以下几种不同的结构形式来分析花键拉刀的利弊。(1)只拉削花键的矩形花键拉刀。这种拉刀在设计时,只设计拉削花键键槽的刀齿,因此要求工件预制孔要有适当高的精度,否则很难保证内花键大、小径的同轴度要求。(2)圆孔—花键复合花键拉刀。这种拉刀在设计时,可以将拉刀的圆孔齿放在花键齿之前,这种结构的拉刀在拉削时是先拉削圆孔也就是小径,然后拉削花键,这种拉削形式能保证内花键大、小径有较高的同轴度,同... 相似文献
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陈传颖 《机械工人(热加工)》1955,(11)
用刀具来镗削内孔时,如果同时要求尺寸准确、表面光潔和生产效率高,是很难达到的。如果采用整准拉刀或球形压刀来压光内孔,就可以得到很好的效果。用球形压刀压光工件内孔的情形如图1所示。图中1是球形压刀,2是工件,3是压床床面。球形压刀是一个淬过火的钢球,在压床的压力下挤过工件内孔,而将工件内孔表面压光。用整准拉刀压光工件内孔的方法也和这相似。应用压光的方法,可以加工平滑的圆柱孔,也可以加工具有浅槽、切口及稜面的孔。 相似文献
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Experimental study on operating temperature in laser-assisted milling of silicon nitride ceramics 总被引:1,自引:1,他引:0
Xinwei Shen Shuting Lei 《The International Journal of Advanced Manufacturing Technology》2011,52(1-4):143-154
Operating temperature plays a significant role in laser-assisted milling (LAMill) of silicon nitride ceramics. Understanding the features of temperature variation can improve the performance of LAMill. Based on the analysis of operating temperature, this paper aims to provide guidelines on parameter selection for LAMill from three aspects: laser?Csilicon nitride interaction mechanism, effect of parameters on temperature, and evaluation of surface quality of the machined workpieces. First, the laser?Csilicon nitride interaction mechanism is explored via heating experiments. It is found that the formation of silica bubbles at the thin top layer of the workpiece can slightly increase the temperature of silicon nitride workpieces due to the heat energy released from the oxidation process. Then, the trends of temperature variations in LAMill are obtained through a parametric study. The key parameters such as laser power, laser beam diameter, feed rate, and preheat time are highlighted. At last, the surface quality of the machined workpieces under different operating temperatures is evaluated in terms of edge chipping, surface finish, and surface residual stress. It is shown that high operating temperature leads to low cutting force, good surface finish, small edge chipping, and low residual stress. In addition, the temperature range for brittle-to-ductile transition should be avoided since the cutting force decreases slowly due to the rapid increase of fracture toughness. 相似文献
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YiHang Fan ZhaoPeng Hao MinLi Zheng FengLian Sun ShuCai Yang 《The International Journal of Advanced Manufacturing Technology》2013,69(9-12):2659-2667
In machining operation, the surface quality is one of the most important requirements for many workpieces. Because of the special physical and chemical properties, good-machined surface quality becomes a key issue to solve in machining Inconel 718. In this paper, PVD-TiAlN-coated carbide tools were used to turn Inconel 718. Based on observing the tool wear and machined surface morphology, the main factors affecting surface quality at different cutting speeds were analyzed. The optimal cutting temperature was calculated, according to the above analysis and Archard adhesion wear model, and further cutting parameters optimization was conducted, on the basis of the proposed optimal cutting temperature. The optimized cutting parameters based on optimal cutting temperature can be considered to improve surface quality. 相似文献
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基于制造企业滚刀CAD的研制 总被引:1,自引:0,他引:1
介绍开发面向制造企业的滚刀CAD系统及可视化设计 ,通过ADS VB应用程序设计和数据库管理 ,实现滚刀CAD。用该系统设计制造了花键滚刀和齿轮滚刀。结果表明滚刀系统集成化设计可大大缩短产品的设计制造周期 相似文献
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T. V. Sreerama Reddy M. Venkatarama Reddy R. Venkatram A. Senthilkumar 《Machining Science and Technology》2013,17(2):269-281
In the present work, coated tungsten carbide tool inserts of ISO P-40 grade were subjected to deep cryogenic treatment at ?176°C. Turning studies were conducted on AISI 1040 workpieces using both untreated and deep cryogenic treated tungsten carbide cutting tool inserts. The turning performance was evaluated in terms of flank wear of the cutting tool inserts, main cutting force and surface finish of the machined workpieces. The flank wear of deep cryogenic treated carbide tools was observed to be lower than that of untreated carbide tools in machining of AISI 1040 steel. The cutting force during machining of AISI 1040 steel was lower with the deep cryogenic treated carbide tools when compared with the untreated carbide tools. The surface finish produced on machined AISI 1040 steel workpieces was superior with the deep cryogenic treated carbide tools as compared to the untreated carbide tools. 相似文献
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During the electrochemical machining (ECM), the cathodes designed by the existing methods are mainly unitary cathodes, which can be only used to produce the workpieces with the same shapes. However, there are few researches on designing cathodes for machining the different workpieces with the different surfaces. This paper presents the grid cathode composed of the square cells to produce the workpieces with different shapes. Three types of the square cells, 2.5 mm′2.5 mm, 3 mm′3 mm, and 4 mm′4 mm, are utilized to construct the plane, the slant, and the blade cathode. The material of the cathode and the anode is CrNi 18 Ti 9 , and the ingredient of electrolyte is 15% NaCl and 15% NaNO 3 . The machining equilibrium machining current and time are acquired and analyzed, the machining process and the workpiece quality are compared between using the grid cathode and the unitary cathode. Moreover, the machining errors on the workpiece surface are measured and analyzed, and the error reasons are traced and discussed to obtain the better surface quality of the workpiece. The experiment and analysis results show that the grid cathode can be used to manufacture the workpieces with complex shapes in certain range of the error. The workpiece quality improves with the size of the square cell being reduced, and if the square element is small enough, the workpiece quality is almost equal to the one machined by the unitary cathode. The proposed research realizes a single cathode machining the different workpieces with the different surfaces. 相似文献
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H. H. Shahabi M. M. Ratnam 《The International Journal of Advanced Manufacturing Technology》2010,48(1-4):213-226
In the past, roughness values measured directly on machined surfaces were used to develop mathematical models that are used in predicting surface roughness in turning. This approach is slow and tedious because of the large number of workpieces required to obtain the roughness data. In this study, 2-D images of cutting tools were used to generate simulated workpieces from which surface roughness and dimensional deviation data were determined. Compared to existing vision-based methods that use features extracted from a real workpiece to represent roughness parameters, in the proposed method, only simulated profiles of the workpiece are needed to obtain the roughness data. The average surface roughness R a, as well as dimensional deviation data extracted from the simulated profiles for various feed rates, depths of cut, and cutting speeds were used as the output of response surface methodology (RSM) models. The predictions of the models were verified experimentally using data obtained from measurements made on the real workpieces using conventional methods, i.e., surface roughness tester and a micrometer, and good correlation between the two methods was observed. 相似文献