Necking machine for blanking treatment of transmission shaft

The necking machine comprises an equipment body, a conical opening is formed in the equipment body, a plurality of installation plates are installed in the conical opening in a sliding mode, the opposite ends of the installation plates are detachably connected with abutting blocks, the abutting blocks are arranged in a barrel shape, and the abutting blocks are connected with the conical opening in a sliding mode. A pushing mechanism is installed on one side of the equipment body, a moving plate is connected to the pushing mechanism, a sliding part is installed at one end of the installation plate in a sliding mode, a sliding shaft is fixed to the upper end of the sliding part, and the sliding shaft is installed in the moving plate in a sliding mode. According to the utility model, a single power source can be adopted to drive a plurality of parts to synchronously operate, meanwhile, the operation synchronism and stability of each part can be ensured, the necking operation on a transmission shaft is facilitate