Abstract: The present invention relates to a quick change structure for multi-functional saws and a quick change method. The quick change structure has a head housing, an output shaft and a quick change device. On the quick change device, a quick change handle can be pulled to drive an eccentric block, a movable rod, a small cylindrical compression spring and a movable bracket in turn such that the second cylindrical pin at the lower part of the movable bracket moves downward in the guide slot of each one of locking pins, driving the locking pins to rotate around a third cylindrical pin to fold together. After a saw blade is placed, the locking pins will unfold when an upward force is applied, and then the locking pins lock the saw blade to realize quick change of the saw blade.

Abstract: The present invention relates to a rapid-replacing structure of multifunctional saw, including a head housing, a tool rest and an output device, wherein the output device comprises an output shaft. It also includes a quick-change device that consists of a rapid-replacing buckle, an eccentric block, a movable rod, a collet chuck, a tensioning rod and a compression spring. The rapid-replacing buckle and the eccentric block are connected with the top of the head housing through a straight pin. The movable rod is arranged in the output shaft, with its top end closely connected to the eccentric block and its bottom end connected to the tensioning rod by screw thread. The rapid-replacing structure of the multifunctional saw can realize the purpose of blade removal and replacement simply by shifting the rapid-replacing buckle on the upper side of the head housing, without using other auxiliary means, so it is simple and fast to operate.