基于DEFORM的轴承钢球冷镦模具优化

对锥鼓形球坯冷镦加工进行分析研究,建立了饱满度、圆化度、冷镦力、体积等评价指标,设计虚拟正交试验,用DEFORM进行仿真分析,最终得出合理的球坯工艺参数以及相应的模具主要尺寸。通过对比,优化后的球坯比原来球坯冷镦力减小35%,模具磨损情况也大有改观。     

耐热钢轴承斜油孔加工方法

分析耐热钢轴承内圈斜油孔加工存在的难点,通过改制钻头、优化切削参数和加工工艺,解决了曲面加工直径1 mm以下深、斜油孔时钻头容易折断的问题。     

实验设计（DOE）技术在PCB微孔钻削工艺参数优化中的应用

针对印刷电路板（PCB）钻孔加工的质量问题，对微钻头的设计和微孔钻削工艺进行了分析。以钻孔质量为优化目标，运用实验设计（DOE）正交分析方法，对钻孔加工中影响钻孔质量的各种工艺参数进行了分析与计算，获得了经过实际生产验证的一组最佳钻孔工艺参数。     

电沉积金刚石钻头工艺研究

本文采用Ni-Co合金电镀液,通过电沉积方法在麻花钻头表面沉积一层或多层金刚石磨料,试验结果表明,所获得的金刚石钻头可以用于玻璃、铁氧体、玛瑙、石材、陶瓷等硬脆性材料的钻削加工.本文对电镀过程中各主要工艺参数的影响进行了试验研究,优化了电沉积工艺参数,并初步分析了加工硬脆性材料的机理.     

GB/T3098.22-2009《紧固件机械性能细晶非调质钢螺栓、螺钉和螺柱》附录B浅析——8.8级细晶非调质钢紧固件应用技术研究

GB/T 3098.22-2009附录B向用户提供一种用非调质冷镦钢线材加工8.8级高强度紧固件的工艺方法.省去冷镦前的退火和冷镦后的调质热处理工序,通过拉拔工艺的调整、稳定化处理技术获得8.8级高强度紧固件各项性能.     

GB／T3098．22--2009《紧固件机械生能细晶非调质钢螺栓、螺钉和螺柱》附录B浅析——8．8级细晶非调质钢紧固件应用技术研究

GB／T3098．22—2009附录B向用户提供一种用非调质冷镦钢线材加工8．8级高强度紧固件的工艺方法。省去冷镦前的退火和冷镦后的调质热处理工序．通过拉拔工艺的调整、稳定化处理技术获得8．8级高强度紧固件各项性能。     

盖板件高效铣削表面粗糙度预测与工艺参数优化

为了保证7075铝合金盖板件铣削表面质量和提高铣削加工效率,进行工艺参数优化,通过响应曲面法(RSM)构建铣削加工表面粗糙度预测模型,分析铣削工艺参数对表面粗糙度的影响规律。基于表面粗糙度预测模型建立高效铣削工艺参数优化目标方程,采用改进的粒子群算法(PSO)对目标方程进行优化,运用优化后的工艺参数对某盖板件进行铣削加工。试验结果表明：采用优化后的工艺参数进行盖板件铣削加工可以满足表面粗糙度要求,验证了预测模型的准确性和改进PSO方法的可行性。     

小深孔光整加工及工艺参数优化

小深孔光整加工是较复杂的工艺难题。本文介绍了在不具备专用深孔加工钻头及设备的情况下,对小直径深孔进行光整加工的方法、刀具结构,并对工艺参数进行优化。     

热处理工艺对工件线切割加工性能的影响

热处理工艺在现代制造业中占有极其重要的地位,为了探究热处理工艺对工件线切割加工性能的影响,运用田口实验设计方法,分析了SKD61热作模具钢在不同热处理工艺下线切割加工的加工性能。实验结果表明,热处理工艺对工件的材料去除率(MRR)和表面粗糙度(Ra)均有较大的影响,在线切割加工中不能忽视这一影响因素且必须予以足够地重视;同时运用主效应分析方法分析了热处理方式及其它加工参数对MRR和Ra的影响规律,实验结论对于进一步指导实际加工具有一定的参考意义。     

典型零件的机械加工工艺探讨

阐述了典型零件加工工艺,从时间、工具两个方面分析了典型零件的机械加工工艺的局限,基于此,提出了典型零件加工工艺的优化方式,即挑选特性优越的Φ8.5 mm钻头,避免钻头裂开并且利用先进的精加工技术缩短典型零件的加工时间。分析认为,通过对典型零件的机械加工工艺进行优化,加快了加工进度,减少了成本,从而提高了生产效率。     

地质钻杆镦头过程中产生裂纹的原因分析与解决方法

钻杆在加工过程中需要对两头进行镦头加厚处理,但经处理后的钻杆头部在后续加工中成批出现裂纹.通过对钻杆材质采用化学成分分析、光学显微镜金相组织检查以及力学性能测试等方法,对出现裂纹的部位进行了分析.结果表明,材料原始组织铁素体和珠光体呈带状分布,导致材料出现各向异性.在镦头过程中,应力在镦头变径处造成集中,超过了材料的抗弯极限,导致其发生脆性开裂,从而出现裂纹.经试验,合理选择加热速度和冷却时间,可以减缓材料带状组织的影响,降低镦头部位出现裂纹.     

Optimization of cutting parameters on drill bit temperature in drilling by Taguchi method

In this study, the optimization of the cutting parameters on drill bit temperature in drilling was performed. Al 7075 work piece and the uncoated and Firex® coated carbide drills in the experimental were used. The optimization of the cutting parameters was evaluated by Taguchi method. The control factors were considered as the cutting speed, feed rate and cutting tool. Taguchi method was used to determining the settings of cutting parameters. The L₁₈ orthogonal array was used in experimental planning. The most significant control factors affected on drill bit temperature measurements was obtained by using analysis of variance (ANOVA). Taguchi design method exhibit a good performance in the optimization of cutting parameters on drill bit temperature measurements. In addition, the empirical equations of drill bit temperatures were derived by using regression analysis. The obtained equations results compared with the drill bit temperature measurement results. The empirical equations results indicated a good agreement with experimental results.     

Analysis of temperature changes on the twist drill under different drilling conditions based on Taguchi method during dry drilling of Al 7075-T651

In this work, effects of drilling parameters (drilling depth, feed rate, and spindle speed) on the twist drill bit temperature and thrust force in the dry drilling of Al 7075-T651 material were experimentally investigated. During dry drilling experiments, drill bit temperature and thrust forces were measured. Drill temperatures were measured by inserting standard thermocouples through the coolant (oil) hole of TiN/TiAlN- coated carbide drills. The settings of drilling parameters were determined by using the Taguchi experimental design method. An orthogonal array, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) are employed to analyze the effect of drilling parameters. The objective was to establish a model using multiple regression analysis between spindle speed, drilling depth, feed rate, and drilling method with the drill bit temperature and thrust force in a Al 7075-T651 alloy material. The study shows that the Taguchi method is suitable to solve the problems with a minimum number of trials as compared with a full factorial design .     

硬地层单牙轮-PDC钻扩联合钻头破岩特性

提出了新型单牙轮-PDC钻扩联合钻头,先依靠单牙轮破岩钻孔,释放地应力,产生岩石损伤,再助推PDC钻头刮切破岩。运用有限元法,建立钻扩联合钻头、双级PDC和常规PDC钻头破岩的非线性动力学模型。通过对岩石本构关系进行D-P准则描述以及确定岩石破碎的判据,分析钻扩联合钻头钻进硬地层的破岩机理,开展了3种钻头动态破岩过程的对比研究。结果表明：钻扩联合钻头在钻进过程中井底井壁的岩石应力得到明显释放,大大提高了岩层可钻性;在硬地层中钻扩联合钻头钻进速度提高的主要原因是拉应力破岩;钻扩联合钻头在硬地层钻进过程中的扭转振动大大降低,破岩效率更高,钻头寿命更长;由于单牙轮领眼破碎岩石的作用,钻扩联合钻头对井底岩石的冲击破碎能力更强,在硬地层中钻进更快。研究结果为新型单牙轮-PDC钻扩联合钻头的研发提供了参考。     

全局力平衡PDC钻头布齿优化设计

针对聚晶金刚石复合片(PDC)钻头在钻井破岩过程中因受力不平衡,导致钻井倾斜、井径扩大、钻头产生横向振动和涡动,造成钻头早期失效的问题,基于已有PDC钻头切削力学知识,构建了PDC钻头弯曲力矩及全局力平衡布齿优化设计模型,并提出模型求解方法。布齿设计实例结果表明,采用全局力平衡布齿设计方法得到的布齿结构可使PDC钻头在不同进尺条件下均能保持全局力平衡状态,尤其低进尺（小于1 mm）时的力平衡状态得到极大改善,提高了PDC钻头的钻井稳定性,对于改善钻头受力、提升钻头使用寿命、提高钻井质量与效率具有重要意义。     

麻花钻锥面刃磨参数电子封闭图的研究

基于锥面刃磨法的工作原理,设计了麻花钻内锥面刃磨的虚拟样机,并基于LabVIEW开发环境,编制了锥顶距A和偏距e的封闭图,当设定钻头公称直径、半锥角等参数后,即可获得后角和横刃斜角临界值范围内的4、e值及其对应的后角、横刃斜角值,此封闭图适合于内、外锥面刃磨法参数的选取,为高质量后刀面刃磨参数的确定提供了一种简捷高效的方法.     

基于MATLAB和ABAQUS的螺旋钻杆参数优化与数值模拟

以螺旋钻杆输煤生产率为目标函数,利用MATLAB软件进行了螺旋钻杆结构参数的优化设计,使得优化后螺旋钻杆的输送能力显著提高,并在优化结果的基础上,应用ABAQUS软件建立了钻头钻进系统有限元仿真模型,并进行了钻孔成形模拟,获得了在最优转速钻孔时需要施加在钻头上的最大轴向压力及最大扭矩,为螺旋钻杆后续研究奠定了基础.从轴压及扭矩变化图线可知,轴压及扭矩的大小随钻头与煤体接触面的变化而变化,轴压及扭转力矩产生的急剧波动是钻进过程中煤体不连续性破碎造成的.     

钻尖直线刃后刀面的砂轮磨削轨迹算法研究

为了提高钻尖后刀面的加工精度和保证砂轮磨削姿态的灵活性,研究了钻尖直线刃后刀面数控磨削过程中的砂轮轨迹计算方法。定义了钻尖直线刃后刀面的结构参数,建立了钻尖直线刃线及后刀面的数学模型;定义了钻尖直线刃后刀面的坐标系和砂轮基准磨削姿态;在此基础上,采用坐标变换矩阵描述砂轮运动方式,借助运动学原理推导了基于工件坐标系的砂轮磨削位置和姿态的计算方法。该方法保证了钻尖直线刃后刀面的精度,可灵活调整砂轮磨削姿态。基于VC++环境开发了计算程序,并进行仿真加工验证,验证了算法的有效性。     

Effects of different cooling conditions on twist drill temperature

In the past, many researchers have studied wear developed on drilling tools mainly due to the high temperatures generated which accelerate thermally related wear mechanisms and thereby reducing tool life. This paper deals with an experimental investigation on the effect of an internal coolant approach (for different air pressure) on drill bit temperature, comparing it with an external coolant approach and dry cutting. Drill temperatures were measured by inserting standard thermocouples through the coolant (oil) hole of TiN/TiAlN-coated carbide drills. Experimental studies have been conducted using Al 2014 alloy materials. In the drilling tests, cutting conditions had different spindle speeds, coolant approaches and feed rate values. The settings of drilling parameters were determined by using the Taguchi experimental design method. An orthogonal array, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) were employed to analyse the effect of coolant approaches and drilling parameters. The objective was to establish a model using multiple regression analysis between spindle speed, coolant (air) pressure and feed rate with the drill bit temperature. Mathematical models for drill bit temperature are proposed that agree well with the experiments.     

麻花钻的数学建模及钻削过程有限元分析

为预测麻花钻的几何参数及钻削用量对钻削力和钻削温度的影响,通过对标准麻花钻的几何造型及锥面磨法的研究,用UG做了3D实体模型,基于Deform3D建立了有限元模型,并对钻削过程的钻削力和钻削温度的分布做了仿真研究。结果表明,扭矩、轴向力和切削温度均随麻花钻的直径增加而增大,随进给量的减小而降低。