The utility model relates to the field of
needle valve type hot runners, and discloses a
needle valve double-cylinder structure which comprises a shell, an
electromagnetic valve, a main
nozzle, a splitter plate, a hot
nozzle dragging position and a
junction box, the
electromagnetic valve is fixedly connected to the upper surface of the shell, the main
nozzle is fixedly connected to the front surface of the shell, the splitter plate is fixedly connected to the middle of the inner surface of the shell, and the hot nozzle dragging position is fixedly connected to the
junction box. The upper portion and the lower portion of the splitter plate are each fixedly connected with a set of hot nozzle dragging positions. According to the automatic fastening
butt joint device, through the arrangement of the connecting shaft, the connecting frame, the transmission wheel, the motor, the driving wheel, the driven wheel, the rotating shaft, the
ring block and the sleeve rod, after a connecting piece and the automatic fastening
butt joint device are in
butt joint, the sleeve rod is driven by the motor to start to rotate, and the bolt is driven to rotate under the condition that the sleeve rod sleeves the inside hexagonal bolt, so that automatic fastening butt joint is completed; and a motor rotation program is synchronously started and stopped, so that the connection tightness of each connection point of the device and the feeding device can be ensured to be the same, and the risk of leakage at the interface is reduced.