Power Tool
To provide a power tool capable of suppressing variations in motor characteristics between external power sources with different voltage while preventing an increase in the size of the power tool. The power tool includes: a motor including a stator on which a plurality of windings are wound and a rotor rotatable relative to the stator; an output unit driven by rotation of the rotor; a power source connection part connectable to an external power source serving as a driving power source of the motor; power source voltage detecting means configured to perform detecting a voltage of the external power source connected to the power source connection part; and connection form changing means configured to perform changing a connection form of the plurality of windings on the basis of the voltage of the external power source.
1 . A power tool comprising:
an n-phase brushless motor including a stator on which a plurality of windings are wound and a rotor rotatable relative to the stator, each phase of the n-phase brushless motor including at least two of the plurality of windings;
an output unit driven by rotation of the rotor;
a power source connection part connectable to an external power source serving as a driving power source of the motor;
a voltage detector configured to perform detecting a voltage of the external power source connected to the power source connection part; and
a controller configured to perform changing a connection form of the at least two windings in each phase on the basis of the voltage of the external power source.
2 . The power tool according to claim 1 , wherein the power source connection part includes:
an AC connection terminal part connectable to an external AC power source; and
a DC connection terminal part connectable to an external DC power source.
3 . A power tool comprising:
a motor including a stator on which a plurality of windings are wound and a rotor rotatable relative to the stator;
an output unit driven by rotation of the rotor;
a power source connection part connectable to an external power source serving as a driving power source of the motor, the power source connection part including:
an AC connection terminal part connectable to an external AC power source; and
a DC connection terminal part connectable to an external DC power source;
a voltage detector configured to perform detecting a voltage of the external power source connected to the power source connection part; and
a controller configured to perform changing a connection form of the plurality of windings on the basis of a voltage of the external AC power source connected to the AC connection terminal part.
4 . A power tool comprising:
a motor including a stator on which a plurality of windings are wound and a rotor rotatable relative to the stator;
an output unit driven by rotation of the rotor;
a power source connection part connectable to an external power source serving as a driving power source of the motor, the power source connection part including:
an AC connection terminal part connectable to an external AC power source; and
a DC connection terminal part connectable to an external DC power source;
a voltage detector configured to perform detecting a voltage of the external power source connected to the power source connection part; and
a controller configured to perform changing a connection form of the plurality of windings on the basis of a voltage of the external DC power source connected to the DC connection terminal part.
5 . (canceled)
6 . The power tool according to claim 1 , wherein the controller performs the changing the connection form by switching the connection form of the at least two windings in each phase between a series connection and a parallel connection.
7 . The power tool according to claim 1 , wherein the controller performs the changing the connection form by switching the connection form of the at least two windings in each phase among a series connection, a parallel connection, and a series-parallel connection.
8 . The power tool according to claim 1 , wherein the controller is further configured to perform:
changing a voltage based on the external power source after performing the changing the connection form; and
applying the changed voltage to the n-phase brushless motor.
9 . The power tool according to claim 8 , wherein the controller performs the changing the voltage by changing a duty ratio.