Oscillation controller for an oscillating body capable of adjusting acceleration thereof

An oscillation controller for an oscillating body, for setting an acceleration of said oscillating body when the oscillating body is oscillated by a drive motor about an axis of rotation that extends in a horizontal direction, wherein

• if said oscillating body is accelerating, a load torque due to gravity acting on the drive motor is obtained at an angular position about said axis of rotation at the start of acceleration of said oscillating body, and
• if said oscillating body is decelerating, a load torque due to gravity acting on the drive motor is obtained at an angular position about said axis of rotation at the end of deceleration of said oscillating body,
• if said load torque acts in a direction in which it hinders acceleration or deceleration of said drive motor, a specified maximum acceleration is calculated by subtracting said load torque from an output torque of said drive motor and further dividing a resultant value of the subtraction by inertia about said axis of rotation,
• if said load torque acts in a direction in which it assists acceleration or deceleration of said drive motor, a specified maximum acceleration is calculated by adding said load torque to an output torque of said drive motor and further dividing a resultant value of the addition by the inertia about said axis of rotation, and
• an acceleration for the oscillating body at the time of accelerating or decelerating is set so as not to be greater than the calculated specified maximum acceleration.

A machine tool comprising:

• an oscillating body capable of oscillating about an axis of rotation that extends in a horizontal direction;
• a drive motor for oscillating said oscillating body about said axis of rotation;
• and
• a control unit for setting an acceleration of said oscillating body at the time of accelerating or decelerating so as not to be greater than a specified maximum acceleration;
• wherein said control unit obtains a load torque due to gravity acting on said drive motor at at least one angular position defined about said axis of rotation,
• if said load torque acts in a direction in which it hinders acceleration or deceleration of said drive motor, the specified maximum acceleration is calculated by subtracting said load torque from an output torque of said drive motor and further dividing a resultant value of the subtraction by inertia about said axis of rotation, said load torque being a maximum load torque within a range of angles at which the oscillating body is accelerated or decelerated,
• if said load torque acts in a direction in which it assists acceleration or deceleration of said drive motor, the specified maximum acceleration is calculated by adding said load torque to an output torque of said drive motor and further dividing a resultant value of the addition by the inertia about said axis of rotation, said load torque being a minimum load torque within a range of angles at which the oscillating body is accelerated or decelerated, and
• an acceleration for the oscillating body at the time of accelerating or decelerating is set so as not to be greater than the calculated specified maximum acceleration.

A machine tool comprising:

• an oscillating body capable of oscillating about an axis of rotation that extends in a horizontal direction;
• a drive motor for oscillating said oscillating body about said axis of rotation;
• and
• a control unit for setting an acceleration of said oscillating body at the time of accelerating or decelerating so as not to be greater than a specified maximum acceleration;
• wherein said control unit obtains a load torque due to gravity acting on said drive motor at at least one angular position defined about said axis of rotation,
• if said oscillating body is accelerating, a load torque due to gravity acting on the drive motor is obtained at an angular position about said axis of rotation at the start of acceleration of said oscillating body, and
• if said oscillating body is decelerating, a load torque due to gravity acting on the drive motor is obtained at an angular position about said axis of rotation at the end of deceleration of said oscillating body,
• if said load torque acts in a direction in which it hinders acceleration or deceleration of said drive motor, a specified maximum acceleration is calculated by subtracting said load torque from an output torque of said drive motor and further dividing a resultant value of the subtraction by inertia about said axis of rotation,
• if said load torque acts in a direction in which it assists acceleration or deceleration of said drive motor, a specified maximum acceleration is calculated by adding said load torque to an output torque of said drive motor and further dividing a resultant value of the addition by the inertia about said axis of rotation, and
• an acceleration for the oscillating body at the time of accelerating or decelerating is set so as not to be greater than the calculated specified maximum acceleration.