A quick-release structure, comprising a fork, a clamping unit, and a quick-release unit;
- an outer side of one end of the fork having a receiving space, a horizontal circular through hole being defined in the receiving space;
- the clamping unit including a base, a plurality of arc-shaped clamping members, an elastic ring, and a shaft cover;
- the base being fixed in the receiving space, an outer side of the base having a circular cavity, a circular perforation corresponding in position to the circular through hole being defined in a center of the circular cavity, the circular cavity being provided with a plurality of elongated grooves arranged radially at equal intervals around the circular perforation;
- the plurality of arc-shaped clamping members being arranged equidistantly in the circular cavity, the arc-shaped clamping members each having a first axle to slide in a corresponding one of the elongated grooves, the arc-shaped clamping members each having a second axle extending in a direction opposite to the first axle;
- the elastic ring being buckled on an outer periphery of each arc-shaped clamping member, a center of the arc-shaped clamping members arranged in a ring being formed with an adjustable clamping opening;
- an inner side of the shaft cover being formed with a plurality of axle grooves arranged annularly, the second axles of the arc-shaped clamping members being pivotally connected to the respective axle grooves, the shaft cover being rotably connected to the base;
- wherein when the shaft cover is rotated, the arc-shaped clamping members are synchronously driven, the arc-shaped clamping members each have the second axle as an axis for the first axle to slide toward an outer end of the corresponding elongated groove, and the arc-shaped clamping members counteract an elastic force of the elastic ring to expand the adjustable clamping opening;
- the quick-release unit having a shaft, one end of the shaft being sequentially formed with a neck section and an enlarged end, the enlarged end having a diameter greater than that of the adjustable clamping opening in a retracted state, another end of the shaft being provided with a locking member;
- wherein the shaft of the quick-release unit is inserted through two ends of the fork, the enlarged end of the shaft is inserted in the circular perforation from an inner side of the fork to counteract the elastic force of the elastic ring, so that the first axles of the arc-shaped clamping members slide toward the outer ends of the respective elongated grooves and the arc-shaped clamping members each having the second axle as the axis are expanded outwardly for the enlarged end to pass through the adjustable clamping opening;
- after the enlarged end passes through the adjustable clamping opening, the adjustable clamping opening subjected to the elastic force of the elastic ring is retracted to clamp the neck section, and the shaft is tightened by the locking member.