Bit attachment device and tightening module

A tightening module comprising:

• a drive assembly;
• a movable rod capable of moving rotationally and axially under the action of the drive assembly;
• and
• a bit attachment device comprising an attaching sleeve, a disassembling-attaching assembly and an abutting assembly arranged in sequence, wherein:
• a first end of the attaching sleeve is coupled to a movable rod within the tightening module via a buffer assembly, so as to move with rotational and axial movements of the movable rod;
• the disassembling-attaching assembly includes an attaching shaft whose first end forms a tight fit with a second end of the attaching sleeve via a spline structure, and a second end of the attaching shaft configured for attachment to a bit;
• the abutting assembly is movably provided at a position located on an outer periphery of the second end of the attaching sleeve, so that said abutting assembly-it can abut against the attaching shaft in a radial direction, or move toward a direction away from the attaching sleeve to loosen the attaching shaft;
• the first end of the attaching sleeve is sleeved with the buffer assembly for mitigating an impact force generated when the movable rod moves toward the direction of the attaching sleeve, and the second end of the attaching sleeve is formed with an internal spline;
• the second end of the attaching sleeve is sleeved on the first end of the attaching shaft, and an external spline matched with the internal spline of the attaching sleeve is formed on the side of the attaching shaft close to the first end thereof;
• the buffer assembly includes a spring for abutting against the movable rod and a spring sleeve;
• and
• one end of the spring sleeve is open to install the spring, and the other end thereof abuts against the first end of the attaching shaft.