立方氮化硼磨具修整技术研究

本文论述了CBN磨具修整机理,建立了修整过程中整形和修锐的数学模型及公式并从理论上分析了各种整形方法和修锐方法,并给出了优选工具及方法。     

Form crush dressing of diamond grinding wheels

Form crush dressing is a method to profile diamond grinding wheels. Especially for complex profiles with intricate details and high accuracy an improved form crush profiling system has been developed. The system consists of a hydrostatically supported form crushing disc embedded in a swiveling axis. Form disc wear, which forms a major bottleneck in reaching high accuracy, has been minimized through the development of an advanced wheel synchronization control strategy. Various vitrified grinding wheels and a crushable metal bonded wheel have been tested to show the general applicability of the method to grinding wheels with brittle bond systems.     

陶瓷结合剂金刚石砂轮修整的研究(Ⅲ)——杯形砂轮修整器的修整机理

在前两篇文章中,笔者提出了一种以杯形砂轮为工具的金刚石砂轮修整方法。本文探讨了以该方法修整陶瓷结合剂金刚石砂轮的机理。主要结论如下:(1)杯形砂轮的修整作用主要取决于从GC砂轮上脱落下来的磨粒对金刚石磨粒和结合剂桥的冲击。(2)杯形砂轮越软,其上脱落下来的磨粒越大,修整效率越高,但金刚石砂轮表面越粗糙。(3)用烧结体多点金刚石笔修整时,从最外表面开始,金刚石砂轮表层磨粒依次被金刚石笔削去。(4)作为添加材料加入到陶瓷结合剂金刚石砂轮中的碳化硅磨粒,其顶端在磨削初期即被磨平。(5)磨削难磨材料时,最好使用无添加材料的陶瓷结合剂金刚石砂轮。     

Wear of diamond dresser in laser assisted truing and dressing of vitrified CBN wheels

The rapid wear of diamond dressers in truing and dressing of vitrified CBN wheels remains an unsolved problem, and significantly affects the grinding performance of dressed wheels. Through combining laser-induced thermal effects into the process, laser assisted truing and dressing opened a new avenue for reducing the wear rates of diamond dressers. In this study a systematical investigation on the wear properties of diamond dressers in the novel laser assisted truing and dressing has been conducted, including (1) a theoretical analysis of some underlying items in the process of laser irradiation, (2) an experimental investigation of wear rates in the laser assisted truing and dressing, and (3) influences of the HAZ (heat affected zone) left by the last pass of laser assisted dressing. Experimental results show that the wear ratios of diamond dressers in the laser assisted dressing depend on laser power, depth of cut, and feed rate. Moreover, the heating history also has some impact on the wear ratios of diamond dressers.     

NURBS在微机控制球面轴承内套双沟一次磨削加工中的应用

球面内套双沟道一次磨削加工技术对保证对称球面加工精度、提高粗糙度水平和磨不镁粗利,是提高球面轴承等机械产品质量和生产效率的先进技术手段。本文介绍应用ＮＵＲＢＳ技术实现在对砂轮修整中的数字插补控制方法。     

三坐标数控磨轮修整器的无累积误差插补控制方法

本文从成型磨削特点出发,引出新型计算机数控成型磨轮修整概念,提出了平面三座标数控修整方法,为了提高修整精度,从原理上详细介绍和分析了无累积误差插补计算机控制方法。     

螺杆转子成形磨削砂轮的修整

成形砂轮的修整质量直接影响着螺杆转子的齿形精度和表面质量。根据空间啮合原理,建立了螺杆转子磨削加工的数学模型,推导了成形砂轮与转子的接触线方程。针对转子端面齿形为离散点的情况,通过三次样条插值法、追赶法和MATLAB内置fsolve函数的衔接使用求解出了砂轮的轴向截形。介绍了CNC砂轮修整器的工作原理,根据计算结果设计了砂轮的修整方案,研究了砂轮截形与中心距的变化规律并提出了数控程序编制的简化方法。该修整方法简单可靠、精度高,适合复杂曲线廓形的加工。     

金刚石砂轮修整新技术的研究

通过一系列试验，研究了适用于MK9025数控光学曲线磨床上金刚石砂轮修整的3种新技术：激光修整法、气中电火花放电修整法、激光辅助机械修整法，实验结果表明3种金刚石砂轮修整技术都是可行的，是很有前途的新技术。     

金属结合剂金刚石砂轮的修整研究(Ⅱ)——修整金属结合剂金刚石砂轮的机理

在上一篇文章中。笔者提出了一种新的测量磨粒突出高度的方法,并就磨粒突出高度同砂轮磨削性能的关系进行了研究。本文探讨了结合剂密实型金刚石砂轮的修整机理,着重讨论修整时磨粒周围结合剂的会除过程。证明了去除结合剂的机制是杯形砂轮上脱落下来的GC磨粒的研磨作用。主要结论如下:(1)修整时,GC磨粒从杯形砂轮上脱落并研磨结合剂,从而产生修整效果。因此,杯形砂轮修整器在对金属结合剂金刚石砂轮进行整形的同时,也对其进行修锐。(2)控制冷却液流量使GC砂轮表面附有一层游离磨粒,可以使修整比最高。(3)只要修整次数足够多,平均磨粒突出高度只取决于修整条件。(4)游离GC磨粒的尺寸越大,研磨作用越强,因此修整比越高,平均磨粉突出高度越大。     

金刚石微粉砂轮软弹性修整研究（Ⅰ）：——软弹性修整法及其机理

金属结合剂金刚石砂轮，尤其是金属结合剂金刚石微粉砂轮，很难采用磨削法修整。针对磨削修整法的不足发明了软弹性修整法。本文讨论了软弹性修整法的修整机理，介绍了软弹性修整方法的修整装置。     

成形砂轮高精度修整技术研究

介绍成形磨齿的原理与现状.分析数控插补修正砂轮中金刚石工具自身形状误差对砂轮修整精度的影响;并提出相应的解决措施,即在修整过程中,通过工具的旋转,以保持工具与砂轮间实际修整作用点不变,从而消除工具误差对砂轮修整精度的影响.并设计出具体修整装置.实践表明:采用该方法不仅可以保持高的工作精度,而且可以延长工具的使用寿命.     

细纱机锭杆CBN砂轮成形磨削及修整方法研究

本研究采用CBN砂轮代替传统的棕刚玉砂轮,进行了细纱机锭杆表面成形磨削实验研究.锭杆材料选用热轧轴承钢GCr15.磨削在无锡产M11100专用磨床上进行,CBN砂轮为CBN-850磨料、粒度160#、浓度100%、硬度为J-K.砂轮主轴转速提高到2000 r/min,采用英国产泰勒索夫5对加工表面进行测量,结果表明锭杆表面粗糙度由Ra 0.8降低到Ra0.4 μm.精度由IT8提高到IT6.用酸蚀法检测锭杆表面,结果显示完全克服了磨削烧伤现象;采用金相显微镜测定表面变质层达到0.035 mm以下.由于CBN砂轮磨粒耐磨、锋利,使得砂轮修整次数大大减少,生产效率提高20倍以上.文中还阐述了采用计算机数控系统修整砂轮成形面的原理.     

放电参数对电火花修整金刚石砂轮效率的影响

利用电火花工艺对金刚石砂轮进行修整具有明显的技术优势。为了提高其修整效率,探究电气参数对砂轮修整效率的影响,采用控制变量法设计了试验流程,在专用数控机床上利用电火花工艺对金刚石砂轮进行修整。在测量砂轮的修整量时,由于砂轮去除量微小,分别计量砂轮的去除厚度和去除质量,两种方法互相印证,说明结果的正确性。试验结果表明:在一定范围内提高脉冲电源的输出功率,可以提高其修整效率,在一定范围内增加脉冲间隔,反而会提高砂轮修整效率。分析结果可以为提高电火花修整金刚砂轮的效率提供参考。     

CIB—D砂轮磨削性能、磨损机理及电解修整的试验研究

探讨了铸铁结合剂金刚石（CIB—D）砂轮磨削时的磨削比、磨削力、砂轮使用寿命、磨损机理以及电解修整的方法。研究表明,用这种砂轮磨削难加工材料时具有很高的效率和很长的刀具使用寿命,而且,通过对切削力的研究,探讨了这种砂轮的磨钝标准。最后,对这种砂轮的电解修整方法进行了初步研究,基本摸清了电解修整基本规律及其参数。     

A study on laser touch dressing of electroplated diamond wheels using pulsed picosecond laser sources

An investigation to explore the possibility of touch dressing of electroplated diamond wheels using a pulsed picosecond laser (ps-laser) beam (Yb:YAG) is presented. The laser beam is irradiated on the wheel to cut the diamond grains within a defined grain protrusion without any thermal damage on the nickel bond. The laser parameters were systematically varied to achieve a reliable touch dressing process. The microscopic investigations prove thermal damages neither on the diamond grain nor on the bond. Series of SiC wheel dressing experiments were carried out to compare mechanical touch dressing of the electroplated diamond wheel with laser dressed wheels.     

先进光学磨削中杯形修整技术开发及应用

对于金刚石砂轮修整,尤其是有高精度要求的圆弧金刚石砂轮,杯形砂轮修整技术可以获得较好的砂轮磨削性能以及修整效率。本文开发了配套超精密平面磨床使用的杯形修整器,分析了其机械误差影响,并完成了修整实验及砂轮表面测量及半径拟合处理,从宏观上考察了该修整器对砂轮磨削性能的提高,结果证明该修整器可以进行有效修整,提高了加工工具精度,能满足金刚石砂轮修整使用要求。     

Characterization and modelling of the grinding process of metal matrix composites

In this paper, some relationships for modelling force components, cutting energy and workpiece surface roughness in grinding of metal matrix composites, are proposed. To this end, experimental data obtained from tests carried out on a horizontal surface grinder are employed. Grinding wheels based upon alumina abrasive were used and aluminium alloy samples reinforced with silicon carbide were ground. The empirical models obtained could be utilised to predict how the cutting parameters affect the grinding process and the machining quality of these non-traditional materials. The influence of shape, orientation and content of the reinforcement on material grindability is taken into consideration.     

Precision surface grinding of Mn–Zn ferrite with in-process electro-discharge dressing (IEDD)

Ferrite is widely used as a material for hard disk magnetic heads, but is difficult to grind because of its high hardness and brittleness. Therefore, a superabrasive (diamond) wheel is used for precision surface grinding of this material. But the conventional dressing method cannot be applied to the diamond wheel. This study describes a newly proposed method for carrying out effective in-process electro-discharge dressing (IEDD) of a diamond wheel. Using IEDD, the surface roughness of Mn–Zn ferrite was improved and the grinding force was reduced. IEDD is a good method to obtain efficient grinding and surface grinding of ferrite.