Power tool

Abstract

The invention relates to a power tool which comprises a casing, a driving motor, an output shaft, a clutch structure and a torque adjusting mechanism. The torque adjusting mechanism comprises a torsion cover, a screw cap and an elastic device. The elastic device comprises a plurality of elastic parts installed between the screw cap and the clutch structure in parallel, a plurality of first matching portions matched with one end of each elastic part are arranged on the screw cap, a plurality of second matching portions corresponding to the first matching portions one by one are arranged on the clutch structure, two ends of each elastic part abut against a corresponding first matching portion and a corresponding second matching portion respectively, and different distances are formed between the plurality of first matching portions and the plurality of second matching portions to enable the plurality of elastic parts to provide different elasticity. The power tool meets the requirement that a high gear has high output torque and a low gear has low output torque and is simple in structure and convenient to implement.

Description

technical field [0001] The invention belongs to the field of gun drill power tools, and in particular relates to a torque adjustment mechanism of a power tool. Background technique [0002] The current gun drill power tools include electric drills, electric screwdrivers, impact drills, impact wrenches, etc. Among them, the electric drill is used to drill holes on the workpiece; the electric screwdriver is used to tighten the screw to the workpiece; the impact drill is mainly used to punch holes in the workpiece of brittle materials; The power tools mentioned above all have a torque adjusting mechanism. [0003] For example, Chinese invention patent ZL20051012869.5 discloses a torque limiting unit, which includes a compression spring device, which is composed of a plurality of compression springs, the compression springs are parallel to the axis of the output shaft, and along the circumference of the torque cover The direction is evenly distributed, and the length and stiff...

AI Technical Summary

Problems solved by technology

However, at the moment of switching from the first stroke to the second stroke, the elastic force of the elastic device will produce a step-like jump change, causing the torque value of the torque adjustment mechanism to be discontinuous during the entire adjustment process, and the requirement for a specific torque value Under this condition, the torque limiting unit cannot meet the torque requirements, nor can it be fine-tuned

[0004]However, in order to solve the problem that the above-mentioned torque limiting unit can perform torque adjustment, Chinese patent application number 200910262037.3 discloses a power tool, the torque adjustment mechanism of which includes Torque cover, screw cap, and elastic device, wherein one end of the elastic device is against the screw cap, and the other end is against the clutch structure. By rotating the screw cap, the elastic device is compressed to generate elastic force, thereby realizing the adjustment of the torque, and at the same time A number of compression spring devices with different parameters are also used, so that within the adjustable stroke range of the screw cover, the elastic force of the elastic device and the compressed displacement of the compression spring device present a parabolic compression spring characteristic curve, and the torque value is continuously adjustable. In order to achieve higher output torque in the high gear, a higher spring coefficient is required, which leads to too much output torque in the low gear, and cannot be used in the working condition that requires small torque

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