Prevention of Chatter Vibration in Ball End-Milling Operation of Curved Surfaces with Cutting Edge of Reduced Tool-Chip Contact Length

减少刀切接触长度的切削刃防止曲面球头铣削加工中的颤振

• 批准号: 08650154
• 负责人: USUI Eiji
• 金额: $ 1.34万
• 依托单位: Tokyo Denki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650154/
• 关键词: Ball End-Mill; Cutting Edge of Reduced Tool-Chip Contact Length; Chatter Vibration; Cutting Mechanism

The etrects of ball end-mill with cutting edge of reduced tool-chip contact length upon prevention of chatter vibration are examined experimentally in die sinking operation. The operation is performed in the manner of x - z axs control with y axis pick feed for a die cross-section having circular parts, slant parts and flat bottom. It is verified that the reduced contact edge is always effective, regardless of cutting conditions used, radius of the circular part, inclination of the slant, and up or down pass of the end-mill. The threshold depth of cut for chatter occurrence is made 1.5-3 times as much as conventional cutting edge.An analytical system is developed, which enables us to predict three components of cutting force (without chatter) during the end-milling of any cutting conditions by only using orthogonal cutting data as data-base. The predicted force components are proved to be in good agreement with experimental results.This system is further developed to be adapted for dynamic cutting process with chatter vibration, and computer simulation of chatter occurrence is made possible. Through the simulation, it is revealed that the reduced contact length suppresses the cutting force variation when some disturbance is introduced in undeformed chip thickness, hence it would reduce excitation of the vibration system. The simulation system, however, has some deficiencies at present and is not able to predict the stability threshold which agrees with experimental results. The improving trials are still going on.

在开模操作中对具有减少刀具与切屑接触长度的切削刃的球头立铣刀的结构进行了实验检验，以防止颤振。对于具有圆形部分、倾斜部分和平底的模具横截面，以x-z轴控制、y轴拾取进给的方式进行操作。经验证，无论使用的切削条件、圆形零件的半径、斜面的倾斜度以及立铣刀的上走刀还是下走刀，减小的接触刃总是有效的。颤振发生的切削深度阈值是传统切削刃的1.5-3倍。开发了一种分析系统，使我们能够仅使用正交切削数据作为数据库来预测任何切削条件下的立铣削过程中切削力的三个分量（无颤振）。预测的力分量与实验结果吻合良好。该系统进一步发展以适应具有颤振的动态切削过程，并使得颤振发生的计算机模拟成为可能。通过仿真表明，当未变形切屑厚度引入一些扰动时，接触长度的减小抑制了切削力的变化，从而减少了对振动系统的激励。然而，该仿真系统目前存在一些缺陷，无法预测与实验结果相符的稳定性阈值。改进试验仍在继续。