Power tool
AssigneeHitachi Koki Co., Ltd.
InventorsShouichi HIRAI, Kazutaka IWATA
Life of this patent
Estimating the term…
Abstract
An oil pulse tool including: a brushless motor which includes stator windings; a drive circuit configured to apply a driving voltage to any of the stator windings of the brushless motor at a predetermined timing; an oil pulse mechanism portion configured to be rotary driven by the brushless motor; and an output shaft which is connected to the oil pulse mechanism portion, wherein the drive circuit changes an advance angle of the driving voltage in accordance with a rotational position of the oil pulse mechanism portion.
Claims12
An oil pulse tool comprising:
- a brushless motor which includes stator windings;
- a drive circuit configured to apply a driving voltage to any of the stator windings of the brushless motor at a predetermined timing;
- an oil pulse mechanism portion configured to be rotary driven by the brushless motor;
- and
- an output shaft which is connected to the oil pulse mechanism portion,
- wherein the drive circuit changes an advance angle of the driving voltage in accordance with a rotational position of the oil pulse mechanism portion.
An oil pulse tool comprising:
- a brushless motor which includes stator windings;
- a drive circuit configured to apply a driving voltage to any of the stator windings of the brushless motor at a predetermined timing;
- an oil pulse mechanism portion configured to be rotary driven by the brushless motor;
- and
- an output shaft which is connected to the oil pulse mechanism portion,
- wherein the drive circuit controls the driving voltage with a fixed advance angle until a first striking is started, and
- wherein the drive circuit controls the driving voltage with a variable advance angle, in which the advance angle of the driving voltage is changed in accordance with a rotation angle of the oil pulse mechanism portion, after the first striking is started.
A power tool comprising:
- a brushless motor;
- a rotary striking mechanism portion configured to be driven by the brushless motor;
- and
- an output shaft connected to the rotary striking mechanism portion,
- wherein an advance angle of a driving voltage applied to the brushless motor is changed in accordance with a rotational position of the rotary striking mechanism portion.
A power tool comprising:
- a brushless motor;
- a striking mechanism portion configured to be driven by the brushless motor;
- and
- an output shaft connected to the striking mechanism portion,
- wherein an advance angle of a driving voltage applied to the brushless motor is changed in accordance with a position of the striking mechanism portion.
A power tool comprising:
- a brushless motor;
- and
- an output shaft configured to be driven by the brushless motor,
- wherein a load on the output shaft fluctuates periodically,
- wherein, when the load on the output shaft is a low load, an advance angle of a driving voltage applied to the brushless motor is a first advance angle, and
- wherein, when the load on the output shaft is a high load, the advance angle of the driving voltage applied to the brushless motor is a second advance angle which is smaller than the first advance angle.
Dependencies are inferred from the claim text.