Method, apparatus and controller for machining non-circular work pieces

An apparatus for machining of a non-circular profile on a work piece, the work piece having an axis of rotation, said apparatus comprising:

• (a) a plurality of position sensors for deriving a plurality of position signals correlated with a rotational position of said work piece,
• (b) a vibrating tool assembly further comprising;
• (i) a rigid tool block,
• (ii) a tool holder including, first and second ends defining a longitudinal axis, said longitudinal axis being substantially aligned with said axis of rotation, said tool holder mounted to said block at said first end and adapted to receive a machine tool at said second end, said tool holder including an integral spring member for providing relative ease of movement at said second end of said tool holder in a transverse direction generally orthogonal to said longitudinal axis,
• (iii) means for restraining relative movement between said tool holder and said tool block in a direction perpendicular to both said transverse direction and said longitudinal axis, and
• (iv) a solid state actuator arranged to impart vibrational motion to said tool holder at said second end,
• (c) a control system including;
• i) a signal conditioner for generating a square wave from said plurality of position signals,
• ii) means for producing a 2 per rev sinusoidal signal which is phase locked to said square wave signal,
• iii) means for adjusting a magnitude and phase of said 2 per rev sinusoidal signal and producing a magnitude and phase adjusted output signal, and
• iv) an amplifier for amplifying said adjusted output signal,
• whereby a non-circular profile is machined on the work piece with minimum and maximum dimensions precisely located in desired positions and where a desired amount of ovality is achieved.

A method for machining a non-circular profile on a work piece comprising the steps of:

• (a) positioning the work piece within a rotating chuck of a machine in a predetermined orientation, said work piece including an axis of rotation;
• (b) providing a plurality of sensors for deriving a plurality of signal representative of a rotational position of the work piece;
• (c) providing a tool block moveably mounted to the machine;
• (d) mounting a tool holder to said tool block such that a longitudinal axis of said holder is substantially parallel with said axis of rotation, said tool holder including a spring member allowing ease of movement of an end portion of said tool holder in a transverse direction;
• (e) connecting an actuator to said portion of said tool holder;
• (f) providing a control system;
• (g) processing said plurality of input signals within said control system to produce a magnitude and phase adjusted output signal selected to provide a non-circular profile on the work piece, the magnitude being selected to provide the non-circular profile a desired amount of ovality and the phase being selected to provide the non-circular profile a maximum and minimum dimension in desired positions relative to the rotational position of the work piece;
• and
• (h) providing said adjusted output signal to said actuator to produce forces between the tool block and tool holder to machine the non-circular profile on the work piece responsive to said output signal.

An apparatus, comprising:

• (a) a sensor producing a signal correlated with a member's motion,
• (b) a vibrating assembly including;
• (i) a base,
• (ii) a object mounted relative to said base, and
• (iii) an actuator interconnected between said base and said object,
• (c) a control system including:
• (i) means for generating a square wave based upon said signal,
• (ii) a waveform generator for producing a sinusoidal input which is phase locked to said square wave, said generator further comprising a plurality of center adjustable band pass filters, said generator further including feedback means for adjusting a band of each said filter,
• iii) means for adjusting a magnitude and phase of said sinusoidal input and producing a magnitude and phase adjusted output signal, and
• iv) an amplifier for amplifying said magnitude and phase adjusted output signal and producing an amplified output signal
• whereby said amplified output signal is provided to said actuator to vibrate said object.

An apparatus for machining of a non-circular profile on a work piece, the work piece having an axis of rotation, said apparatus comprising:

• (a) a position sensor that derives a position signal correlated with a rotational position of the work piece;
• (b) a vibrating tool assembly, the vibrating tool assembly comprising;
• (i) a rigid tool block,
• (ii) a tool holder including first and second ends defining a longitudinal axis, said tool holder mounted to said block at said first end and adapted to receive a machine tool at said second end, said tool holder including an integral spring member that allows movement of said second end of said tool holder in a transverse direction, said longitudinal axis of said tool holder being disposed substantially parallel to said axis of rotation, and
• (iii) an actuator positioned to impart vibrational motions to said second end of said tool holder along said transverse direction;
• and
• (c) a control system responsive to the position signal that generates an output signal connected to said actuator, said control system including,
• i) a signal conditioner circuit that generates a square wave responsive to the position signal,
• ii) a sinusoidal signal generation circuit responsive to the square wave that produces a two per revolution sinusoidal input signal, the two per revolution sinusoidal input signal being phase locked to said square wave,
• iii) a magnitude and phase adjusting circuit responsive to the two per revolution sinusoidal input signal that produces a magnitude and phase adjusted output signal, and
• iv) an amplifier circuit that amplifies said magnitude and phase adjusted output signal.

An apparatus for machining of a non-circular profile on a work piece, the work piece having an axis of rotation, said apparatus comprising:

• (a) a position sensor that derives a position signal correlated with a rotational position of the work piece;
• (b) a vibrating tool assembly, the vibrating tool assembly comprising;
• (i) a rigid tool block,
• (ii) a tool holder including first and second ends defining a longitudinal axis, said tool holder mounted to said block at said first end and adapted to receive a machine tool at said second end, said tool holder including an integral spring member that allows movement of said second end of said tool holder in a transverse direction, said longitudinal axis of said tool holder being disposed substantially parallel to said axis of rotation, said integral spring member having a transverse stiffness in the range of between about 5,000 lbf./in and about 9,000 lbf./in, and
• (iii) an actuator positioned to impart vibrational motions to said second end of said tool holder along said transverse direction;
• and
• (c) a control system responsive to the position signal that generates an output signal connected to said actuator, said control system including,
• i) a magnitude and phase adjusting circuit responsive to the position signal that produces a magnitude and phase adjusted output signal, and
• ii) an amplifier circuit that amplifies said magnitude and phase adjusted output signal.

An apparatus for machining of a non-circular profile on a work piece, the work piece having an axis of rotation, said apparatus comprising:

• (a) a plurality of position sensors that derive position signals correlated with a rotational position of the work piece;
• (b) a vibrating tool assembly, the vibrating tool assembly comprising;
• (i) a rigid tool block,
• (ii) a tool holder including first and second ends defining a longitudinal axis, said tool holder mounted to said block at said first end and adapted to receive a machine tool at said second end, said tool holder including an integral spring member that allows movement of said second end of said tool holder in a transverse direction, said longitudinal axis of said tool holder being disposed substantially parallel to said axis of rotation, and
• (iii) an actuator positioned to impart vibrational motions to said second end of said tool holder along said transverse direction;
• and
• (c) a control system responsive to the position signals that generates an output signal connected to said actuator, said control system including,
• i) a magnitude and phase adjusting circuit responsive to the position signals that produces a magnitude and phase adjusted output signal, and
• ii) an amplifier circuit that amplifies said magnitude and phase adjusted output signal.

An apparatus for machining of a non-circular profile on a work piece, the work piece having an axis of rotation, said apparatus comprising:

• (a) a position sensor that derives a position signal correlated with a rotational position of the work piece;
• (b) a vibrating tool assembly, the vibrating tool assembly comprising;
• (i) a rigid tool block,
• (ii) a tool holder including first and second ends defining a longitudinal axis, said tool holder mounted to said block at said first end and adapted to receive a machine tool at said second end, said tool holder including an integral spring member that allows movement of said second end of said tool holder in a transverse direction, said longitudinal axis of said tool holder being disposed substantially parallel to said axis of rotation, and
• (iii) an actuator positioned to impart vibrational motions to said second end of said tool holder along said transverse direction;
• (c) a vertical stiffener spring mounted between said second end of said tool holder and said tool block;
• and
• (d) a control system responsive to the position signal that generates an output signal connected to said actuator, said control system including,
• i) a magnitude and phase adjusting circuit responsive to the position signal that produces a magnitude and phase adjusted output signal, and
• ii) an amplifier circuit that amplifies said magnitude and phase adjusted output signal.