An object is to provide the numerical control device of a machine tool which can achieve both a reduction in heat generation and stability in heavy cutting. A numerical control device includes a command transmission portion which transmits a speed command value and a magnetic flux command value to the spindle control portion of a machine tool and a storage portion which stores magnetic flux amounts corresponding to tools that may be used in the machine tool. The numerical control device also includes a tool detection portion which detects a tool selected in the machine tool and a magnetic flux amount setting portion which commands the command transmission portion to read, from the storage portion, a magnetic flux amount corresponding to the tool detected by the tool detection portion and to output the magnetic flux amount to the spindle control portion of the machine tool.

To provide a numerical controller for a machine tool capable of reducing heat generation and realizing stable heavy cutting, and also capable of realizing efficient light cutting. A numerical controller comprises: first speed change means which changes the feed speed of a feed axis drive motor at the start of cutting to an initial speed lower than a command speed, based on magnetic flux content at the start of cutting; and second speed change means which changes the feed speed from the initial speed to the command speed continuously or intermittently based on time elapsed from the start of cutting and a time constant for change in the magnetic flux content.

A numerical controller for controlling a machine tool including a spindle motor formed of an induction motor includes: a storage unit that stores a maximum acceleration at which the spindle motor can operate when a magnetic flux amount of the spindle motor reaches its maximum; a magnetic flux amount acquisition unit that acquires a present magnetic flux amount of the spindle motor; and an acceleration change unit that changes an acceleration of a position command based on a maximum acceleration of the spindle motor stored in the storage unit according to a magnetic flux amount at the start of movement of the spindle motor acquired by the magnetic flux amount acquisition unit when the spindle motor is operated by position control using a position command.

A controller of a machine tool capable of suppressing heat generation and realizing a stable cutting operation during deep cutting is provided. A numerical controller for controlling a machine tool including a spindle motor formed of an induction motor and a feed axis driving motor includes: a magnetic flux amount acquisition means that acquires a present magnetic flux amount of the spindle motor; and a speed change means that changes a speed of the feed axis driving motor on the basis of the magnetic flux amount.

A mobile phone includes an acceleration sensor for detecting acceleration, a magnetic sensor for detecting magnetism, and a controller for determining a type of moving state based on the acceleration detected by the acceleration sensor and the magnetism detected by the magnetic sensor.

An object is to provide the numerical control device of a machine tool which can achieve both a reduction in heat generation and stability in heavy cutting. A numerical control device includes a command transmission portion which transmits a speed command value and a magnetic flux command value to the spindle control portion of a machine tool and a storage portion which stores magnetic flux amounts corresponding to tools that may be used in the machine tool. The numerical control device also includes a tool detection portion which detects a tool selected in the machine tool and a magnetic flux amount setting portion which commands the command transmission portion to read, from the storage portion, a magnetic flux amount corresponding to the tool detected by the tool detection portion and to output the magnetic flux amount to the spindle control portion of the machine tool.

A numerical controller for controlling a machine tool including a spindle motor formed of an induction motor includes: a storage unit that stores a maximum acceleration at which the spindle motor can operate when a magnetic flux amount of the spindle motor reaches its maximum; a magnetic flux amount acquisition unit that acquires a present magnetic flux amount of the spindle motor; and an acceleration change unit that changes an acceleration of a position command based on a maximum acceleration of the spindle motor stored in the storage unit according to a magnetic flux amount at the start of movement of the spindle motor acquired by the magnetic flux amount acquisition unit when the spindle motor is operated by position control using a position command.

To provide a numerical controller for a machine tool capable of reducing heat generation and realizing stable heavy cutting, and also capable of realizing efficient light cutting. A numerical controller comprises: first speed change means which changes the feed speed of a feed axis drive motor at the start of cutting to an initial speed lower than a command speed, based on magnetic flux content at the start of cutting; and second speed change means which changes the feed speed from the initial speed to the command speed continuously or intermittently based on time elapsed from the start of cutting and a time constant for change in the magnetic flux content.

A controller of a machine tool capable of suppressing heat generation and realizing a stable cutting operation during deep cutting is provided. A numerical controller for controlling a machine tool including a spindle motor formed of an induction motor and a feed axis driving motor includes: a magnetic flux amount acquisition means that acquires a present magnetic flux amount of the spindle motor; and a speed change means that changes a speed of the feed axis driving motor on the basis of the magnetic flux amount.