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1、太原理工大学硕士学位论文 电镀单层CBN磨具的研究及其结构优化设计 姓名：王典国申请学位级别：硕士 专业：机械制造及其自动化 指导教师：吕明20080501太原理工大学硕士研究生学位论文电镀单层CBN磨具的研究及其结构优化设计摘要CBN磨料的出现和应用引发了20世纪磨具行业的一次重大革命，由 CBN所制作的磨具已经深入磨削加工的各个领域。高精度窄深槽加工一直 是机械加工的难题，研究开发新型电镀单层CBN磨具，将会为传统机械精 加工工艺的发展提供有力的支持。对于许多由难加工材料制造的航空、汽车、液压泵等零件上有高精度 要求窄深槽加工，特别是宽度为2mm以上的窄深槽加工，采用传统粘结、 烧结的砂轮
2、缓进给磨削工艺，可以通过一次磨削加工出较高精度的窄深槽。 但对于宽度不大于2mm的窄深槽，采用普通砂轮缓进给磨削时，磨料很容 易脱落使砂轮的精度和寿命降低，为了保证加工精度，必须在加工的过程 中对磨具进行修形；由于砂轮工作部位的厚度很薄，在磨削和修整时极易 破碎，而且加工成本很高。因此开发出一种具有更新换代意义的新型磨具 (电镀单层CBN磨料磨削工具)已迫在眉睫。与传统磨具相比，电镀单层 CBN磨具在制作工艺、加工精度和使用寿命等方面都显出了很大的优势。 近几年，国内有关电镀CBN磨具的研究已经取得了很大的进展，但在电镀 CBN薄片砂轮工艺研究上还处于开发阶段，制作成功的高精度电镀CBN薄 片
3、砂轮寿命低，生产成本过高。本文根据电镀理论及窄深槽的磨削特点， 对电镀CBN薄片砂轮的基体设计、制造及其电镀工艺进行了分析研究，并 进行了简单的电镀实验和磨削试验。太原理J：人学硕十研究生学位论文目前电镀CBN薄片砂轮存在的主要问题是磨粒的等高性、均匀性差。 本文从分析影响磨粒等高性和均匀性的原因入手，对落砂法和埋砂法的工 艺特点进行了比较，提出电镀CBN薄片砂轮的置砂工艺采用悬一埋结合的新工艺方法。然后对置砂方案进行了设计，提出镀底镍、置砂、加厚镀分 开进行，置砂时砂轮基体竖放，整个过程分六个区域依次完成，每个区域 同时完成两侧和圆周三个型面的置砂的工艺方案。根据置砂要求设计制造 了一套电镀
4、夹具，从根本上解决了CBN磨粒分布的等高性和均匀性问题。 依据电镀理论、技术分析及掌握的经验，并进行了电镀实验。磨削温度高、砂轮易变形是电镀CBN薄片砂轮磨削窄深槽的主要问题， 本文从改善散热条件和磨削表面的冷却效果、利于减少砂轮内应力和纠正 基体变形出发。专门设计了砂轮夹具，并对砂轮的整体结构进行优化；考 虑到磨削时线速度较大，容易发生振动。为此，通过实验对砂轮做了动平 衡和静平衡配平以及应用有限元法计算砂轮的固有频率，避开了共振区， 降低了磨削加工过程中的振动。为了验证电镀砂轮的磨削性能和使用的可靠性，本文设计了正交实验 进行磨削加工，先采用极差分析得出磨削用量(线速度，进给量，磨削深度)
5、 的影响程度。在通过磨削速度、进给量、磨削深度与粗糙度关系的直观图 得出较优磨削用量组合。考虑到加工效率又对极差分析的结果通过作磨削 速度对粗糙度影响的单因素实验来进一步验证，最后得出了磨削用量最优 组合为v=375ms、ap=4mmmin、h=15mm时，加工表面粗糙度值凡=O046um。 另外，实验也验证了所制作的电镀CBN薄片砂轮当以较高的切削速度缓进 给磨削高速钢时，能加工出宽约为185ram、深15mm窄深槽。这表证明了本太原理工大学硕士研究生学位论文电镀工艺能够满足加工工艺要求，因此，电镀工艺悬一埋结合的方案是可行的。关键词：CBN，-砂轮结构，电镀工艺，悬一埋置砂，磨削实验太原理
6、工大学硕士研究生学位论文RESEACH oF GRINDlNG TooL oF SlNGLELAYER ELECTRoPLATED CBN AND oPTIMlZATIoN DESIGN FoR lTS STRUCTUREABSTRACTThe emergence and applications of CBN abrasive have triggered a great abrasive industry revolution in the 20th century,The abrasive made of CBN have widely applied in all areas of g
7、rindingDeep narrow highprecision machining process has always been a problem，Therefore research and development of new singlelayer plating CBN abrasive will be the strong support for the traditional mechanical finishing processFor many high precision of narrow deep socket machining in the parts made
8、 of difficulttomachine materials from the aerospace，automotive， hydraulic pumps and other highprecision pans，especially the narrow deepsocket with width more than 2 mm，High precision narrow and deep socket can be machined with traditional bond or sinteringBut when machining the socket with width les
9、s than 2mm with traditional process，The abrasive easily sheds，Which lead to the wheelS short expectancy and low precisionToguarantee the precision，The abrasive must be dressed during the machining；But the abrasive are easily broken during the machining and dressi ng because the thickness ofthe machi
10、ning part is very thinMoreover the costs are usually high Therefore the development of new abrasive(abrasive plated with CBN)is urgentV太原理J人学硕十研究生学位论文Compared with the traditional abrasives，abrasives plated with singlelayer CBN have many advantages in production process，working accuracy and lifeIn r
11、ecent years，electroplating CBN abrasive related research has been made a great deal of progress，but in thin electroplating CBN Grinding Wheel Technology isalso in the development stage，the successful production of highprecision thin electroplating CBN grinding wheelslife is low and production costs
12、are too highBased on the theory and electroplating Deep narrow grinding characteristics，the thin electroplating CBN grinding wheel matrix design， manufacture and electroplating process has been analyzed，and simple grinding plating experiments and tests have been doneCurrently the main problems of th
13、in electroplating CBN grinding wheel are poor contour and uniformityDebris from the impact of reasons of contour and uniformity,This article draws a comparison of craft characteristic of falling sand and burying sand，and proposes the new technology methods，That is the combination of suspending sand
14、and burying sandthen this article design sets at the granulating substance plan，and proposes that nickel plating，granulating substance and thicker plating are separately done，substance is granulated at the wheel matrix，the whole process are completed in six regions，and substance is granulated on bot
15、h sides and three circumferential surfaces of each region at the same time，Clamp is designed according tO granulating substance design and manufacturing requirements，Which fundamental ly solves the CBN abrasivecontours and the distribution of uniform issuesBase on the theory ofV1太原理工大学硕士研究生学位论文elect
16、roplating，technical analysis，and the mastered experience，electroplating experiments have been doneHigh grinding temperature，and wheel deforming easily are key issues of grinding narrow and deep socket，This article from the improvement radiation condition and the grinding surfaceS cooling performance，favors the reducedgrinding wheel internal stress and the correction substrate distortion embarks
