On-off device of spiral vehicle door

The utility model relates to a helix vehicle door open and close device, which belongs to an automatic open and close system for vehicle door and is designed for the purposes of resolving the problems as complex structure, large bulk and high cost of the existing automatic open and close device for vehicle door. The utility model is characterized in that: a screw rod with the helix of small lead is input and an internal thread with small lead and spiraled in the middle arranged on the screw rod is combined with the input screw rod in rotation; an external thread with big lead is arranged on external column, which is jointed with an output helix on it in rotation; a guide bar is positioned inside a guiding groove spiraled in the middle and is in parallel with its axes to make the helix in the middle only conduct the axial displacement; a vehicle door swiveling jib is arranged the output helix to control the open and close of the vehicle door. The utility model is mainly composed of three pre-designed in helix, so features simple structure, small bulk, big reduction ratio, low cost and free of noise and waste gas pollution, which is mainly applied for automatic vehicle door open and close system for vehicles with air-conditioners.