Method for suppressing chatter vibrations in a machine tool

Method for suppressing self-excited chatter vibrations at a frequency in the vicinity of the natural frequency of the workpiece in a machine tool having a non-rotating tool comprising the steps of:

• putting an auxiliary holder comprising a revolving body and an associated retainer, on the tool at a given constant load, the tool being fixed to a tool mount by an associated main tool holder;
• shifting the auxiliary holder on the tool until the vibration in the tool system is brought in dynamic balance with the vibration in the workpiece;
• and reciprocating the auxiliary holder on the tool to either side of the so-determined null point, thus continuously changing the natural frequency of the tool system.

In a method of machining a workpiece in which a tool has a first portion secured to a support, an intermediate portion freely projecting from said support in a predetermined direction, and a terminal portion connected to said first portion by said intermediate portion, said terminal portion engages a workpiece and removes material from said workpiece during relative movement of said tool and of said workpiece, whereby vibration may be induced in said tool, the improvement which comprises:

• a. holding an inert mass in contact with said intermediate portion under a force applied in a direction transverse to said predetermined direction;
• and
• b. continuously shifting the contact of said mass with said intermediate portion in said predetermined direction during said relative movement, said applied force being sufficient to impede said vibration.