Method and apparatus for suppressing regenerative instability and related chatter in machine tools

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873558

Segalman, Daniel J ^[1]; Redmond, James M ^[1]

---

1. Albuquerque, NM

Methods of and apparatuses for mitigating chatter vibrations in machine tools or components thereof. Chatter therein is suppressed by periodically or continuously varying the stiffness of the cutting tool (or some component of the cutting tool), and hence the resonant frequency of the cutting tool (or some component thereof). The varying of resonant frequency of the cutting tool can be accomplished by modulating the stiffness of the cutting tool, the cutting tool holder, or any other component of the support for the cutting tool. By periodically altering the impedance of the cutting tool assembly, chatter is mitigated. In one embodiment, a cyclic electric (or magnetic) field is applied to the spindle quill which contains an electro-rheological (or magneto-rheological) fluid. The variable yield stress in the fluid affects the coupling of the spindle to the machine tool structure, changing the natural frequency of oscillation. Altering the modal characteristics in this fashion disrupts the modulation of current tool vibrations with previous tool vibrations recorded on the workpiece surface.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: Sandia Corporation (Albuquerque, NM)
• Patent Number(s): US 6189426
• OSTI ID: 873558
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
suppressing
regenerative
instability
related
chatter
machine
tools
methods
apparatuses
mitigating
vibrations
components
therein
suppressed
periodically
continuously
varying
stiffness
cutting
tool
component
hence
resonant
frequency
accomplished
modulating
holder
support
altering
impedance
assembly
mitigated
embodiment
cyclic
electric
magnetic
field
applied
spindle
quill
contains
electro-rheological
magneto-rheological
fluid
variable
yield
stress
affects
coupling
structure
changing
natural
oscillation
modal
characteristics
fashion
disrupts
modulation
current
previous
recorded
workpiece
surface
natural frequency
workpiece surface
tool assembly
machine tools
tool holder
resonant frequency
cutting tool
machine tool
continuously varying
related chatter
regenerative instability
chatter vibrations
chatter therein
mitigating chatter
suppressing regenerative
periodically alter
/82/408/409/