System for opening and closing a flap

Abstract

A system for opening and closing a motor vehicle, the flap is swivalably mounted along one of its edge areas at a stationary structural component part about a horizontal swiveling axis. A first drive device and a second drive device act in parallel to more like flap from a closed position into an open position. The first drive device is a non-self-locking drive device, and the second drive device comprises a cylinder filled with a fluid under pressure. An interior of the second drive device is divided by a piston into a first work chamber and a second work chamber, wherein a piston rod of the piston is guided outward through the first work chamber. A valve arrangement in the piston closes a flow connection between the first work chamber and the second work chamber in a stationary operating state of the flap.

1 . A system for opening and closing a flap for a motor vehicle, the flap being mounted along one of its edges at a stationary structural component of the motor vehicle so as to be swivelable around a swiveling axis so as to be movable between a closed position and an open position, the system comprising:
 a first non-self-locking drive device coupled between the flap and the stationary structural component, the first drive device being an electromechanical drive device; and   a second drive device acting in parallel with the first drive device, the second drive device being one of a hydraulic, pneumatic, and hydropneumatic drive device, the second drive device comprising:
 a cylinder having a first closed end articulated at one of the stationary structural component part and the flap at a distance from the swiveling axis, the cylinder being at least partially filled with a fluid under pressure; 
 a piston that divides an interior of the cylinder into a first work chamber and a second work chamber; 
 a piston rod coupled to the piston, the piston rod being guided outward through and out of the first work chamber articulated at the other of the flap or the stationary structural component part at a distance from the swiveling axis; 
 a sealing and guiding package adapted to guide the piston rod through and out of the first work chamber; and 
 a valve arrangement forming a flow connection between the first work chamber and the second work chamber, 
 wherein the valve arrangement is closed when the flap is stationary. 
   
   
   
       2 . The system for opening and closing a flap according to  claim 1 , wherein the first drive device is arranged at a first edge area of the flap and the second drive device is arranged at a second edge area of the flap, each edge extending at substantially a right angle from the swiveling axis. 
   
   
       3 . The system for opening and closing a flap according to  claim 1 , wherein the flap is one of a hatchback, a trunk hood, and an engine hood. 
   
   
       4 . The system for opening and closing a flap according  claim 1 , wherein the flap is supported along an edge area so as to be substantially vertical in the closed position and substantially horizontally in the open position. 
   
   
       5 . The system for opening and closing a flap according  claim 1 , wherein the first drive device comprises:
 a rotary drive;   a threaded spindle coupled to the rotary drive and adapted to rotatably drive the threaded spindle, the threaded spindle coupled to one of the flap and the stationary structural component part; and   a spindle nut arranged on the threaded spindle coupled to the other of the stationary structural component part and the flap.   
   
   
       6 . The system for opening and closing a flap according to  claim 5 , further comprising a non-self-locking gear unit coupled between the threaded spindle and the rotary drive. 
   
   
       7 . The system for opening and closing a flap according to  claim 5 , wherein the rotary drive is an electric motor. 
   
   
       8 . The system for opening and closing a flap according to  claim 5 , further comprising a tubular housing in which at least the rotary drive, the threaded spindle, and the spindle nut are arranged. 
   
   
       9 . The system for opening and closing a flap according to  claim 5 , further comprising a spindle tube adapted to enclose the threaded spindle, the spindle tube being connected to the spindle nut at its axial end closer to the rotary drive and is coupled to one of the stationary structural component part and the flap at its axial end remote of the rotary drive. 
   
   
       10 . The system for opening and closing a flap according to  claim 8 , further comprising a protective tube connected to the spindle nut on the end area of the tubular housing remote of the rotary drive coupled to the stationary structural component part or flap by its end remote of the rotary drive. 
   
   
       11 . The system for opening and closing a flap according to  claim 1 , wherein the second drive device is a gas spring, the first work chamber and second work chamber being filled with a gas under pressure. 
   
   
       12 . The system for opening and closing a flap according to  claim 11 , further comprising a piston rod extension extending from the end of the piston rod, wherein the piston, the piston rod, and the piston rod extension are arranged coaxial to the cylinder. 
   
   
       13 . The system for opening and closing a flap according to  claim 12 , further comprising a second piston arranged at the end of the piston rod extension. 
   
   
       14 . The system for opening and closing a flap according to  claim 13 , wherein the piston has a closing spring and the second piston has a second closing spring, wherein the closing springs having substantially identical or different spring forces. 
   
   
       15 . The system for opening and closing a flap according to  claims 1 , wherein the cylinder of the second drive device has a dividing piston, the dividing piston being axially displaceable in the cylinder defining a partial space between the closed end of the cylinder and the second work chamber in the cylinder,
 wherein the partial space is filled with a gas under pressure.   
   
   
       16 . The system for opening and closing a flap according to  claims 15 , wherein the first work chamber and second work chamber are filled with an incompressible fluid. 
   
   
       17 . The system for opening and closing a flap according to  claims 16 , wherein the incompressible fluid is an oil. 
   
   
       18 . The system for opening and closing a flap according to  claim 1 , wherein the valve arrangement includes a closing valve having a valve element by which three switching positions can be occupied, wherein, proceeding from a middle closed switching position, a first opening position can be occupied by the valve element in one direction and a second open position can be occupied by the valve element in the other direction. 
   
   
       19 . The system for opening and closing a flap according to  claim 1 , wherein the valve arrangement is an electrically controllable magnetic valve. 
   
   
       20 . The system for opening and closing a flap according to  claim 19 , wherein the magnetic valve is powered on so as to open the flow connection between the first work chamber and the second work chamber by controlling the first drive device for the flap adjustment. 
   
   
       21 . The system for opening and closing a flap according to  claim 20 , wherein the valve arrangement is arranged in the piston.