新型的高速精车刀

本文对我国工人阶级创造的新型大刃倾角精车刀,进行了分析,并以该刀为例,对大刃倾角刀具的实际切削前角、实际切削后角和实际切削楔角进行了理论推导。     

无槽断屑车刀

在切削金属时,为了保证工作安全和提高生户率, 谢兹琅水轮机工厂的工人M.马尔可夫和A.谢水盖耶夫 建议采用无槽断屑车刀(见图);来破断带状切屑。这是 一种简单、经济而可靠的方法。这种车刀在古比雪夫人 民经济委员会的一些工厂企业里得到了广泛地运用。 I 这种车刀是由标准的正偏刀制成。车刀前面的刃磨 是从主切削刃和副切削刃两边进行的。主切削刃的前角 是双重的。宽度为2～4毫米的刃边2与主切削刀直接相 接的前角力3～7°,硬质合金刀片在刃边后的前角为 12°。后角为8°,而刀杆刃磨面与刀片后的后角为12°。 副切削刃的倾角为负16°…     

优选法在大切深粗车刀中的应用

加工条件:工件是较大型的铸铁件,加工余量较多(常达30毫米以上),车削部位为外圆和端面,机床是2米落地车床。原来工艺:使用焊接的硬质合金车刀,前角γ和刃倾角λ均为0°,主偏角=75°存在问题:由于采用焊接车刀,且刃倾角和前角均为0°,故车刀强度较低,切削不轻快,不宜     

可调前角刃倾角外圆车刀

可调前角、刃倾角外圆车刀,可以通过调节获得不同的前角和相应的刃倾角,再刃磨出合适的主偏角(75°～90°)、后角等角度、选择所需牌号刀片,对多种金属材料进行切削加工,提高切削效率和加工质量。结构及工作原理: 刀具结构如图1所示。在刀体10上铣一条宽10毫来、夹角55°、轴向前角25°、刃倾角-4°的通槽。槽后部攻M8螺孔,配圆头调节螺钉2顶在刀垫3底面的圆坑内,随着螺钉2的升降,被顶着的刀垫3、     

水平回转成形车刀的参数计算

1　问题的提出成形车刀的切削刃形状比较复杂 ,如采用正交平面前角γ0 和正交平面后角α0 定义成形车刀角度 ,会使成形车刀的测量、制造和刃磨比较困难。为此 ,可将假定进给平面前角γｆ 和假定进给平面后角αｆ 定义为成形车刀的名义前角和名义后角。由于成形车刀的切削刃为折线或曲线 ,因此切削刃上各点的正交平面后角值与该点的主偏角κｒ 有关 ,即ｔａｎα0 =ｔａｎαｆｓｉｎｋｒ,当ｋｒ=0°时 ,α0 =0°。在图 1所示加工情况下 ,成形车刀的后刀面紧贴工件的端面 (Ｗ面 ) ,摩擦现象严重。为保证加工质量和刀具寿命 ,应使成形车刀切削刃…     

银白屑车刀参数的选取

银白屑车刀的切削,利用了积屑瘤对切削的积极作用,在钢类零件的高速重切削中,可显著提高切削效率。通常这种车刀应具有图1所示刃型,即A-A主截面中具有第一前角为Y_1、第二前角为Y_2的两段前面刃型。为了断屑和增强刀具的强度,刀具上还有前角为Y_3的第三段前面。正确的制造银白屑车刀,可使负倒棱上产生稳定的积屑瘤参加切削,使车刀实际工作前角增大,可达35°～45°,这样,减轻了切削力、切削热,切屑呈银白色。同时,由于硬质合金刀具材料与钢亲和力小,积屑瘤连续地以副切屑的     

用CVD金刚石厚膜车刀加工硬质合金的研究

采用CVD金刚石厚膜车刀对K10硬质合金进行了不同安装前角下的切削加工试验,比较分析了刀具的磨损状况和加工表面粗糙度随前角的变化规律。结果表明,增大车刀安装前角的负值,可以抑制切削刃边缘的破碎及直线刃部的剥离破碎,提高工件的加工表面质量。     

大刃倾角斜角切削流屑角的实验研究

用测量前刀面划痕的方法对大刃倾角斜角切削的流屑角进行了测量,并且研究了大刃倾角斜角斜角切削流屑角的变化规律。通过实验,得到大刃倾角斜角切削流屑角经验计算公式。     

关于薄壁环氧玻璃钢管切削角度的工艺技术研究

玻璃钢加工是一种特殊的机械加工工艺方法,而绝大多数的玻璃钢零件都离不开车削工序。车刀作为车削过程的重要刀具,其切削角度的选择对玻璃钢切削产品的质量具有极其重要的意义。针对薄壁环氧玻璃钢管加工,分别研究了车刀前角、后角、主偏角和刃倾角等切削角度的选择。     

平刃斜车的几何计算

用平刃斜车代替普通的平刃精车,能够减少加工系统中的微振,提高表面光洁度;能够进行微量切削,有利于提高切削速度,提高刀具的耐用度。因此该原理已普遍应用于精车、精刨和铣削等方面。如辽宁先进刀具推广队介绍的大刃倾角精车刀(图1所示);宝鸡石油机械厂的机夹大刃倾角精车刀;重庆金属切削刀具交流队的大刃倾角精刨刀以及太原重型机器厂使用的70°大螺旋角铣刀(图3所示)等等。     

双曲面麻花钻主刃的形成与方程简化方法的探讨

介绍了以旋转单叶双曲面作麻花钻钻尖后刀面的数学模型。该钻型主刃是双曲面与螺旋前刀面的交线,此交线与钻头端剖面形成的交点是主刃上的点。根据观察由计算机计算出的该交线与一系列端剖面的交点连线,合理简化了主切削刃方程,并将主刃上的特殊点作为锋角测量基点,以解决由于曲线主刃上各点锋角的不断变化造成刃磨参数不确定性的问题。     

基于平面表像法的任意刃形钻头切削角度的建模与测量

根据钻头前刀面的数学模型,应用平面表像法理论建立了计算曲线刃钻头主刃各点在不同参考系下的工作切削角度(包括工作前角、工作刃倾角、工作主偏角等)的像图。以此为基础,提出一种通过测量主刃投影曲线间接测量主刃各点切削角度的新方法,较好地解决了任意刃形钻头切削角度的测量问题。试验证明,该方法正确而有效。     

AN EXPERIMENTAL EVALUATION OF CUTTING TEMPERATURES DURING HIGH SPEED MACHINING OF HARDENED D2 TOOL STEEL

This paper investigates experimentally the effects of different process parameters on the cutting edge temperature during high speed machining of D2 tool steel using polycrystalline cubic boron nitride (PCBN) tools. The cutting edge temperature is measured using thermocouples. The process parameters considered are cutting speed, feed rate, nose radius, rake angle, and tool wear. The effects of different edge preparations including sharp, honed and chamfered are also investigated. The results show that increasing cutting speed and feed rate increases the cutting temperature while increasing nose radius reduces the cutting edge temperature. In addition, there is an optimum rake angle value at which minimum cutting temperature is generated.     

锥基波形前刀面硬齿面插齿刀切削刃几何角度分析

在提出一种硬齿面插齿刀的新构形方法 (锥基波形前刀面硬齿面插齿刀 )的基础上 ,对新构形方法插齿刀的前角、后角及刃倾角进行了分析 ,建立了切削刃几何角度的数学模型 ,并与原构形法插齿刀进行了对比研究。     

前刀面槽型结构对D型刀片车削球墨铸铁性能的影响

通过切削力、磨损和冲击切削试验,研究了前刀面槽型结构对D型刀片车削球墨铸铁切削性能的影响。试验结果显示,刀具的第一前角对切削力的影响最大;在10°~15°范围内,刀具前角越大,切削力越低;棱带宽度大的刀片具有更加优异的耐磨损性能;具有正刃倾角的刀片显示出更优异的耐冲击性能。     

新构形硬质合金插齿刀切削刃几何角度分析

提出了一种硬质合金插齿刀的新构形方法———异形凸曲前刀面硬质合金插齿刀,对新构形插齿刀的前角、后角及刃倾角进行了分析;建立了切削刃几何角度的数学模型,与原构形硬质合金插齿刀进行了比较研究。     

Blend of sharpness and strength on a ball nose endmill geometry for high speed machining of Ti6Al4V

The applications of titanium alloys are increasingly common at marine, aerospace, bio-medical and precision engineering due to its high strength to weight ratio and high temperature-withstanding properties. However, whilst machining the titanium alloys using the solid carbide tools, even with application of high pressure coolant, reduced tool life was widely reported. The generation of high temperatures at the tool–work interface causes adhesion of work material on the cutting edges, and hence, shorter tool life was reported. In order to reduce the high tool–work interface temperature-positive rake angle, higher primary relief and higher secondary relief were configured on the ball nose endmill cutting edges. Despite of careful consideration of tool geometry, after an initial working period, the growth of flank wear accelerates the high cutting forces followed by work material adhesion on the cutting edges. Hence, it is important to blend the strength, sharpness, geometry and surface integrity on the cutting edges so that the ball nose endmill would exhibit an extended tool life. This paper illustrates the effect of ball nose endmill geometry on high speed machining of Ti6Al4V. Three different ball nose endmill geometries were configured, and high speed machining experiments were conducted to study the influence of cutting tool geometry on the metal cutting mechanism of Ti-6Al-4V alloy. The high speed machining results predominantly emphasize the significance of cutting edge features such as K-land, rake angle and cutting edge radius. The ball nose endmills featured with a short negative rake angle of value ?5° for 0.05～0.06 mm, i.e. K-land followed by positive rake angle of value 8°, has produced lower cutting forces signatures for Ti-6Al-4V alloy.     

An empirical survey on the influence of machining parameters on tool wear in diamond turning of large single-crystal silicon optics

We conducted a series of screening experiments to survey the influence of machining parameters on tool wear during ductile regime diamond turning of large single-crystal silicon optics. The machining parameters under investigation were depth-of-cut, feed rate, surface cutting speed, tool radius, tool rake angle and side rake angle, and cutting fluid. Using an experimental design technique, we selected twenty-two screening experiments. For each experiment we measured tool wear by tracing the tool edge with an air bearing linear variable differential transformer before and after cutting and recording the amount of tool edge recession. Using statistical tools, we determined the significance of each cutting parameter within the parameter space investigated. We found that track length, chip size, tool rake angle and surface cutting speed significantly affect tool wear, while cutting fluid and side rake angle do not significantly affect tool wear within the ranges tested. The track length, or machining distance, is the single most influential characteristic that causes tool wear. For a fixed part area, a decrease in track length corresponds to an increase in feed rate. Less tool wear occurred on experiments with negative rake angle tools, larger chip sizes and higher surface velocities. The next step in this research is to perform more experiments in this region to develop a predictive model that can be used to select cutting parameters that minimize tool wear.     

平前刀面球头铣刀的几何角度分析

分析了平前刀面球头铣刀的几何角度,给出了该铣刀的刀刃参数方程,推导了铣刀法向前角、刃倾角和主偏角计算公式。     

Optimizing the geometric parameters of chamfered edge for rough machining Fe–Cr–Ni stainless steel

Geometry of cutting edge has great influence on performance and reliability of modern precision cutting tools. In this study, two-dimensional finite element model of orthogonal cutting of Fe–Cr–Ni stainless steel has been built to optimize the geometric parameters of chamfered edge. A method to measure the chip curl radius has been proposed. The effect of cutting edge geometric parameters on tool stress and chip curl radius has been analyzed. Then, the chamfered edge parameters have been optimized based on numerical simulation results. It finds that, keeping the equal material removal rate, the optimal geometric parameters of chamfered edge for rough machining Fe–Cr–Ni stainless steel are that the rake angle is from 16° to 17°, and the chamfer length is from 60 to 70 μm. Small (large) rake angle combined with small (large) chamfer length is more reasonable to reduce the tool stress. When the length of land is approximately equal to undeformed chip thickness and the rake angle is larger than 15°, the chip curl radius is minimal. The groove type with large radio of width to depth should be used in the chip breaking based on the optimization results.