| 摘要 |
FIELD: electricity.SUBSTANCE: fastening tool (10) comprises an electric motor (12), a control circuit (26), which disconnects it whenever the established specified value of torque is achieved, and a support bracket (18), receiving energy from screwing. In the control circuit (26) there is a unit (46) of voltage limitation, providing for limitation of voltage occurring on the electric motor (12), which in case of energy reduction accumulated in the support bracket (18) operates as a generator and rotates oppositely to direction of driving motion, to the previously established value of limitation voltage. The limitation voltage value is regulated so that on the one had, the electric motor (12) operating as a generator may without an opposing torque rotate oppositely to direction of the drive, and on the other hand, unacceptable overvoltage may not arise.EFFECT: conditions are provided for safe reduction of energy saved in a support bracket after disconnection of a power-operated fastening tool.13 cl, 6 dwg |
