To provide an electric power tool in which vibration generated in use and back electromotive force of a motor generated in braking are electrically and effectively utilized.

A rechargeable battery 23 is housed in an impact driver 1 with a power code 3, a projecting part 2a is provided on an end of a housing 2, and a projecting part 8a is provided also on a hammer case 8. A piezoelectric element 9 is provided between the two projecting parts. Force due to the vibration generated when using the body is applied to the piezoelectric element 9, and power can be generated using the force. The power is stored in the rechargeable battery 23. Further, the back electromotive force generated in an armature 4 when braking is stored in the rechargeable battery 23. The power in the rechargeable battery 23 allows an LED light 11 to be turned on by an attached switch 24 even when no power is supplied through the power code 3.

COPYRIGHT: (C)2010,JPO&INPIT