Electric screw driver having magnetic force overload protector

Abstract

The invention discloses an electric screw driver having a magnetic force overload protector. The screw driver comprises a shell, a motion delivering mechanism which comprises a motor, a motor gear, a driving shaft gear and a driving shaft, and a screw driver component which comprises a screw driver head, an output shaft and a head cover connected to a mounting slot, wherein a sleeve is arranged on one end of the driving shaft close to the screw driver head; more than two big permanent magnets are arranged outside the sleeve at equal intervals; small permanent magnets having a same number of the big permanent magnets are arranged on the output shaft in the sleeve at equal intervals; a U-shaped shifting fork is fixedly connected to two end faces of the sleeve after being inserted from the exterior of the shell; and the U-shaped shifting fork drives the sleeve to axially slide on the driving shaft. The magnetic force overload protector has simple structure, is capable of efficiently performing the overload protection function, generates no friction and noise, is environment-friendly, and can be set with different limited torques by regulating the shifting fork on the shell.

Description

technical field [0001] The invention relates to a hand-held electric tool, in particular to an electric screwdriver with a magnetic overload protector. Background technique [0002] At present, although there are many types of electric screwdrivers on the market, most of the overload protectors they use are still mechanical control methods, that is, tooth-embedded overload protectors. Driven by the parts to rotate accordingly. For example, in the patent number: 200710070176.4, the mechanical ratchet clutch is used, the biggest disadvantage is that it will generate noise, and the life of the overload protector will be greatly reduced due to repeated friction and impact between the teeth, and the use of electric screwdrivers will also be reduced. life. For example, the overload clutch structures in patent numbers: 99229360.X, 200620106541.3 and 200720112276.4 are very complicated, and there are problems such as difficulty in manufacturing and assembling, and high cost. Con...

AI Technical Summary

Problems solved by technology

For example, in the patent number: 200710070176.4, the mechanical ratchet clutch is used, the biggest disadvantage is that it will generate noise, and the life of the overload protector will be greatly reduced due to repeated friction and impact between the teeth, and the use of electric screwdrivers will also be reduced. life

For example, the overload clutch structures in patent numbers: 99229360.X, 200620106541.3 and 200720112276.4 are very complicated, and there are problems such as difficult manufacturing and assembly, and high cost.

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