How to protect the high-speed rotary wrench and the motor used for the high-speed rotary wrench

摘要

An electric wrench, which is operated in an electric mode and a manual mode, includes a wrench body (10) having a head portion (11) having a ratchet device (13) and a handle portion (12); a motor (20) disposed in the handle portion (12); a current sensor (30) connected with the motor (20) for detecting an operation current value (21) of the motor (20); a controller (40) connected with the current sensor (30), the controller (40) having a setting unit (41) and a comparing unit (42), the setting unit (41) setting a threshold current value (411), the comparing unit (42) comparing the operation current value (21) and the threshold current value (411); a switch (80) activating and deactivating an operation of the motor (20); and a warning device (60) connected with the controller (40). In the electric mode, when the operation current value (21) is greater than the threshold current value (411), the warning device (60) is triggered for user to switch to the manual mode.