Frame connecting structure of folding bicycle

A folding bicycle frame connecting structure is mainly composed of a center shaft tube (2), a limiting buckle ring (3) buckled above the center shaft tube (2), a tail seat (4) installed at the rear end of a main bicycle frame (1) outside the center shaft tube (2), a fixing seat (5) and a rear wheel fork (9) installed at the rear end of the fixing seat (5). The bicycle frame is characterized in that the buckle ring (3) is buckled on a buckle ring installation groove (10) above the middle shaft tube (2), the lower portion of the middle shaft tube (2) penetrates through a vertical through hole (12) of a tail seat (4) at the rear end of the main bicycle frame (1) to be connected to a fixed seat vertical through hole (13) of the fixed seat (5), and installation is fast and convenient. In addition, the structure is simple, parts can be modularly produced, the material cost is reduced, the weight of the whole vehicle is reduced, the productivity is improved, and the cost of the whole vehicle is reduced. 一种折叠自行车车架连接结