The utility model discloses a self -locking card formula nut mechanism, including nut body, joint piece and stop device, joint piece is by side wall and located the baffle and
fender of both ends constitute, and the cavity is formed among three, and nut body is along the axial sliding of screw hole in the
accommodation cavity, and baffle sets up the perforation corresponding with screw hole, and the
accommodation cavity has the starting end and the terminal end, and nut body is in the starting end with baffle abuts, in the terminal end with
fender abuts, limit device is located in the side wall of
accommodation cavity. In this mechanism, the joint piece can act as a
wrench, limiting the nut body rotation, without the traditional tool screw, overcome the obstruction of limited space to installation, improve the installation efficiency in the limited space, avoid affecting production progress and equipment
assembly. When the bolt is screwed into the nut body, the nut body moves from the starting end to the terminal end under stress until it contacts with the limiting device. Because the joint piece cannot be deformed due to environmental influence, it can lock and fix the nut body, effectively preventing it from loosening in vibration,
impact and other environments.