平面螺旋运动包络特性的研究

利用解析几何和条件极值理论研究了用平面 (或圆柱面 )砂轮刃磨钻头时形成的钻尖后刀面的包络特性 ,结果表明 ,刃磨形成的钻尖后刀面由平面螺旋运动包络曲面和位于中心区域的非包络曲面组成。非包络区域面积与螺旋运动导程及砂轮平面与旋转轴的夹角有关 ,导程和夹角越大 ,非包络区域也越大     

面齿轮磨削力建模与工艺影响分析

建立了碟形砂轮磨削面齿轮的理论模型.应用切斜面磨削理论,将不规则的曲面齿面等效转化为平面,结合Gleason点接触椭圆等特征,方便对磨削力进行分析求解.将砂轮上的工作磨粒数均匀划分成单颗磨粒成屑力与滑擦力个体,精确阐述砂轮在磨削面齿轮时的磨削力.经过实验结果与仿真数值的比照分析得到磨削力对磨削用量的影响参数,实验结果表明,砂轮转速与面齿轮磨削力成反比例关系,工件进给速度与磨削速度与面齿轮磨削力成正比例关系.通过磨削力的实验结果与仿真数值对比分析,可得出最大相对误差为１７.９％,此数据证明了建立的模型与实验结果较为契合,能够很好地反映磨削力与磨削用量之间的关系变化,在提高面齿轮磨削精度与工艺上提供了基础的理论依据.     

Distribution of thermal fields in face grinding by slotted abrasive segments

The thermal fields in a workpiece ground by a face tool with discrete abrasive segments are simulated by means of Cosmos Works CAE software. The temperature is considerably reduced in grinding by abrasive segments with longitudinal slots in the base and peripheral planes.     

齿轮磨削装置结构设计

介绍一种能够独立完成粗磨和精磨加工工艺的齿轮磨削工具,在它的磨削面上有一个带有双磨削面的螺旋齿,该螺旋齿通过与齿轮啮合磨削作为齿轮工作面的齿面。磨削面沿着螺旋齿延伸,它包含一个用于进行粗磨过程的粗磨削面和一条用于精磨加工过程的成型线,该成型线延伸至磨削面上。     

提高平面包络环面蜗杆磨削效率的近似加工方法

计算和分析了用锥面砂轮和平面砂轮磨削加工的二次包络环面蜗杆副的啮合性能及蜗杆的根切和齿顶变尖特性,结果表明,当锥形砂轮直径较大时,两种砂轮加工出的蜗杆极为近似,因此可采用大直径锥形砂轮代替平面砂轮近似加工平面包络蜗杆,以提高磨削效率     

采用碟形砂轮的斜齿面齿轮磨齿技术研究

为了制造出高精度硬齿面斜齿面齿轮和获得抛物线传动误差并改善啮合性能,对采用碟形砂轮加工双向修形的斜齿面齿轮的磨齿方法进行了研究。设计了渐开线失配的碟形砂轮齿面,分析了碟形砂轮磨削斜齿面齿轮的展成原理,根据展成原理和用渐开线失配的碟形砂轮并改变砂轮的运动,推导出双向修形斜齿面齿轮的齿面方程。给出了双向修形斜齿面齿轮的齿面计算和接触分析实例,结果表明:理论齿面的最大齿面误差为5.98×10-4μm,采用碟形砂轮加工双向修形斜齿面齿轮的磨齿方法是可行的,获得了斜齿面齿轮抛物线传动误差,避免了边缘接触并改善了斜齿面齿轮的啮合性能。     

Precision cylindrical face grinding

The mathematical models and experimental validations of precision cylindrical face grinding using a narrow ring superabrasive wheel are presented. The high pressure seal in diesel engine fuel systems demands the μm-scale form tolerance specifications and has driven the development of precision face grinding using the superabrasive wheel. Two mathematical models were developed: one was applied to predict the convex or concave face profile and another was used to simulate the abrasive trajectories, which become the cross-hatch grinding marks on the ground face. Cylindrical face grinding experiments were conducted. Experimental measurements of face profile and abrasive trajectories were used to validate the theoretical results. For high-pressure sealing surfaces, the height of face profile and grinding trajectories were two critical characteristics for design and manufacturing. Two design tools, a linear approximate solution for the profile height and an atlas for grinding trajectories, were developed to assist the selection of process parameters for the machine setup.     

喷钼涂层与ZL105同平面磨削的实现

某小型航空发动机气缸盖,由于有喷钼涂层,不同材料的同一平面磨削是制约发动机性能的关键工艺。针对该气缸盖的特殊结构及喷涂层特点,采用合理的磨削工艺参数,合适的砂轮及适当的装夹方式,在精密平面磨床上实现了对喷钼涂层与ZL105同一平面的磨削,提高了磨削效率,改善了工件形状精度和表面粗糙度。     

基于正交试验法的平面磨削用量的优选

通过在M7130平面磨床上的试验,采用正交试验方法对平面磨削用量进行分析研究,从而进一步了解平面磨削用量对已加工表面质量的影响规律,及其影响的主次关系,为合理选择平面磨削用量提供可靠的依据.     

A study on the grinding of the major flank face of error-free spur slice cutter

A grinding method for the major flank face of error-free spur slice cutter is proposed according to urgent demand for the slice cutter in practical production. The geometrical characteristic of the major flank face is analyzed based on the surface Gaussian curvature. On this basis, the grinding motion model based on B-type CNC five-axis tool grinding machine is built. The grinding point path planning method according to the accuracy requirement of the major flank face is proposed. The interference checking and avoiding method is also found. The major flank face of a slice cutter is grinded based on the above study result. As a result, the machining error of the major flank face is less than 0.01 mm and the surface roughness is Ra0.3. This result meets the accuracy requirement that the machining error and surface roughness of the major flank face need to be respectively less than 0.01 mm and Ra0.4. The machining example shows that the study result in this paper is valid for the major flank face grinding. This paper provides a technical support for the manufacturing of error-free spur slice cutter.     

电镀小直径CBN环形砂轮端面磨削沟槽底面

在对小直径环形砂轮端面磨削沟槽底面过程中的磨粒切屑厚度进行解析的基础上,设计了电镀小直径ＣＢＮ环形砂轮端部结构尺寸,作为提高砂轮寿命的措施,实验分析磨削冷却液供给方式和倾斜砂轮轴磨削法的效果。     

轴向超声辅助端面磨削金属表面形貌及粗糙度预测

轴向超声辅助端面磨削被广泛应用于难加工材料加工,而磨削后的表面粗糙度对构件摩擦、疲劳等服役性能有重要影响。超声振幅的大小对轴向超声辅助端面磨削金属表面形貌和粗糙度有较大影响,但是现有模型中并未考虑实际加载对振幅的影响,因此提出了一种考虑加载状态下振幅变化的轴向超声辅助端面磨削金属表面形貌及粗糙度预测方法。根据砂轮粒度及尺寸建立了考虑磨粒随机分布的砂轮端面模型,并对轴向超声辅助端面磨削磨粒的三维磨削轨迹进行了数学描述,生成了加工后的表面三维数据矩阵并对表面粗糙数值进行了计算。在此基础上,研究了粗糙度随振幅的变化规律,提出了振幅衰减形貌映射系数这一概念,并给出了其标定方法。通过振幅衰减形貌映射系数近似计算出加载状态下的振幅并代入到所建立的轴向超声辅助端面磨削表面形貌及粗糙度预测模型中,实现了金属表面形貌模拟及粗糙度预测。最后,通过试验对所建模型的正确性进行了验证。     

外球面球轴承外圈装配倒角的控制

外球面球轴承外圈端面厚度较小,在端面及外球面均留有磨削余量的情况下,其装配倒角较难控制,在车加工外球面球轴承外圈球面倒角时,常常由于车加工后留磨余量不合理,到磨加工后,或由于外球面与端面处成锋利尖角,造成轴承碰伤和入座困难;或使端面厚度减小,影响磨加工时工件吸不稳及成品套圈硬度检查。本文提供一种控制方法,很好地解决了这个问题,经过多年实际应用,效果很好。     

硬齿面齿轮精加工技术的现状与展望

硬齿面精加工在加工精度和加工效率上取得了一些进步,出现了一些新的工艺方法。本文对国内外硬齿面的滚齿、插齿、剃齿、珩齿以及磨齿的最新工艺方法及装备进行了介绍,尤其是对磨齿加工的成形法和展成法工艺现状进行了详细介绍,指出了硬齿面精加工方法的发展方向。     

磁研法在模具曲面中的抛光机理与技术研究

针对目前模具自由曲面抛光过程的难加工问题.按照模具曲面抛光要求,结合电磁场理论,提出采取磁性的磨料,通过磁场中磁力的作用实现对模具自由曲面型腔抛光加工的新工艺.从磁力研磨的加工特点着手,对抛光工艺过程的主要参数进行分析,并对磁力研磨运动轨迹的规划和生成进行探讨,提出自由曲面磁力研磨时获取均匀表面去除的方法.     

砂轮磨损对锥度球头立铣刀前角的影响研究

基于直柄球头立铣刀前后刀面的磨削加工运动关系,推导出锥度球头立铣刀前刀面的磨削加工运动关系,以SolidWorks软件为开发平台,利用Visual Basic 6.0进行二次开发,开发出锥度球头立铣刀前刀面的磨削加工仿真系统和刀具参数分析系统,从而模拟加工出锥度球头立铣刀的前刀面,得出较为理想的刃形曲线。然后分析了砂轮直径磨损对锥度球头立铣刀球刃前角和周刃前角的影响,用以指导锥度球头立铣刀的实际生产。     

APPLICATION OF VECTOR ROTATING METHOD IN GRINDING INVOLUTE WORM WITH PLANE ENVELOPE METHOD

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大型对数凸形圆柱滚子磨削加工结果分析

为满足客户需求,开展了大型圆柱滚子对数凸度成形磨削加工试验,阐述了加工原理,确定了磨削加工工艺.根据圆柱滚子凸度轮廓的已知数据,结合Solidworks样条曲线拟合,得到砂轮工作面内凹曲线上相应点的修整量占比.采用直线插补原理控制金刚石笔修整轨迹,将砂轮工作面修整成内凹的对数曲线廓形,加工时将砂轮工作面形状复映到滚子素...     

轴承套圈贯穿式双端面磨削及质量控制

通过对双端面磨削过程的分析和实践,总结出适当的调整砂轮和安排磨削量及控制产品质量的方法。     

Diamond face grinding of WC-Co composite with spark assistance: Experimental study and parameter optimization

Electro-discharge machining (EDM) characteristics of tungsten carbide-cobalt composite are accompanied by a number of problems such as the presence of resolidified layer, large tool wear rate and thermal cracks. Use of combination of conventional grinding and EDM (a new hybrid feature) has potential to overcome these problems. This article presents the face grinding of tungsten carbide-cobalt composite (WC-Co) with electrical spark discharge incorporated within face of wheel and flat surface of cylindrical workpiece. A face grinding setup for electro- discharge diamond grinding (EDDG) process is developed. The effect of input parameters such as wheel speed, current, pulse on-time and duty factor on output parameters such as material removal rate (MRR), wheel wear rate (WWR) and average surface roughness (ASR), are investigated. The present study shows that MRR increases with increase in current and wheel speed while it decreases with increase in pulse on-time for higher pulse on-time (above 100 μs). The most significant factor has been found as wheel speed affecting the robustness of electro- discharge diamond face grinding (EDDFG) process.