Wednesday, October 31, 2007

成形铣刀斜向铲磨用砂轮截形的计算www.tool-tool.com

Bewise Inc. www.tool-tool.com Reference source from the internet.

1 砂轮截形的计算

加工汽轮机叶片用叶根铣刀要求精度高、耐磨损且能多次重复使用。该铣刀齿形的轴向截形如图1所示。图中A2B及IJ两段直线垂直于X轴,若采用普通铲磨法加工刀具齿形,则在该两段直线处不能形成侧后角,刀具用于切削时将首先在此处磨钝,即产生“勒刀”现象。若采用分段铲磨方法,即先铲磨A2B 和IJ段之外的曲线,再斜向铲磨这两段直线,虽可保证前刃面齿形,但在重磨后齿形将发生改变,影响零件加工精度。若采用整体斜向铲磨法,则HG 直线段的尺寸难以控制。为解决这一问题,在实际生产中可采用修形砂轮辊子对A~G和H~Z两段分别进行斜向铲磨,这种加工方法既可保证刀具重磨后的齿形, 又可节省刀具制造工时。
如图2所示,对铣刀进行径向铲磨时,为计算砂轮截形,需已知以下参数:工件截形深度api,被铲磨铣刀外径处端面前角gfa,被铲磨铣刀半径r0,被铲磨铣刀齿形上任一点A的极角di,铣刀截形宽度li,被铲磨铣刀上任一点A处的矢径ri,被铲磨铣刀齿数z0,铲背量K。铣刀轴向截形A点处的坐标为Ti(计算时将各点轴向齿形的纵坐标代入即可),则径向铲磨时砂轮截形的计算公式为
ri=r0-Ti
di=arcsin[(r0/ri)singfa]-gfa
对于已给定的工件(铣刀),将各段的轴向齿形坐标代入迭代公式,即可计算出q=0°时的砂轮截形GX(I)和GY(I)。

2 影响砂轮截形的因素分析

斜向铲磨时,砂轮既有铲背运动(阿基米德螺旋运动),又有斜向分运动,此时砂轮截形主要受斜铲角度q、砂轮直径D、工件几何参数等因素的影响。
  1. 斜铲角度q的影响
    如图3所示,如采用相同的铲背量K,因为NP1=K/tana1,NP2=K/tana2(a1a2分别为A点处的径向和斜向顶刃后角),又因为NP1=NP2cosq,所以tana2=tana1cosq,即径向和斜向的顶刃后角不同。如径向和斜向顶刃后角相同,即a1=a2,则可得K2=K1/cosq,即K值增大。
    将切削刃上A点的法向后角记为anA,它与铲磨后角的关系为tananA=tana2sinq。因为tana2=tana1cosq,所以tananA=(1/2)tana1sin2q,即sin2q=2tananA/tana1
    在实际生产中,可根据加工需要选择斜铲角度q值,从而确定当量工件直径D1的值。为保证A2B处良好的切削性能,通常选取anA=3°

  2. 砂轮直径D的影响
    如图4所示,设X为下一个刀齿的顶点,则斜向铲磨时要求当砂轮直径上的点尚未到达或刚好到达X点时,凸轮必须回程,否则将会破坏下一个刀齿的轴向截形。根据砂轮结构特点可知,砂轮最小直径的最大值应为Ø75mm,由此可推断出铲背量K值约为2,将D1及K=2代入迭代公式,并重新计算齿形坐标点,即可得到砂轮的实际截形。
    另外,由于对刀不可能十分准确,因此应考虑铲磨时砂轮串位的需要。为此,应对砂轮辊子相应段的尺寸作相应调整。


歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對廠商高品質的刀具需求,我們可以協助廠商滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具、協助客戶設計刀具流程、DIN or JIS 鎢鋼切削刀具設計、NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航 太刀具設計、超高硬度的切削刀具、醫療配件刀具設計、汽車業刀具設計、電子產業鑽石刀具、木工產業鑽石刀具等等。我們的產品涵蓋了從民生刀具到工業級的刀 具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!

BW Bewise Inc. Willy Chen willy@tool-tool.com bw@tool-tool.com www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 TEL:+886 4 24710048 / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end millAerospace cutting toolФрезерыCarbide drillHigh speed steelMilling cutterCVDD(Chemical Vapor Deposition Diamond )PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden Finger’PCD V-Cutter’PCD Wood tools’PCD Cutting tools’PCD Circular Saw Blade’PVDD End Mills’diamond tool Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) FreseElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer.

Bewise Inc. www.tool-tool.com

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт www.tool-tool.com для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web www.tool-tool.com for more info.

No comments: