Door component with a controllable damping device and method for damping a movement of a door

Abstract

A door component has a controllable damping device containing a magnetorheological fluid as a working fluid. Two connection units can move relative to one another. One of the two connection units can be connected to a support structure and the other of the two connection units can be connected to a moveable door unit of a vehicle in order to damp a movement of the door unit between a closed position and an open position under control of a control device. The damping device has an electrically adjustable magnetorheological damping valve which is current-less in an adjusted state of the damping valve. A damping property of the damping device is continuously adjusted as needed via an electrical adjustment of the damping valve.

1 . A door component for a pivotable door of a motor vehicle, comprising:
 a controllable damper device containing a magnetorheological fluid and having two connector units that are movable relative to one another, said two connector units including a first connector unit connectable to a supporting structure of the vehicle and a second connector unit connectable to the pivotable door;   a control device controlling said damper device to dampen a pivoting movement of the door at least partially between a closed position and an open position;   said damper device including at least one electrically settable magnetorheological damping valve which maintains a set state in an electrically deenergized state, in order, through electrical setting of said damping valve, to set a desired damping characteristic of said damper device in the electrically deenergized state of the damping device; and   a sensor device disposed to detect an angular position of the pivotable door, said sensor device being a friction wheel disposed to detect a relative movement of said two connector units with respect to one another;   said control device being configured to set said damping valve to a low damping action relative to a high damping action, such that said damping valve acts with the low damping action in the electrically deenergized state when the pivotable door is in the closed position, and configured to set said damping valve to the high damping action relative to the low damping action, such that the damping valve acts with the high damping action in the electrically deenergized state when the pivotable door is in the open position.   
     
     
         2 . The door component according to  claim 1 , wherein said damping valve is formed with a flow channel configured to conduct the magnetorheological fluid therethrough, wherein a variable magnetic field is applied to said flow channel to create a second magnetic field which acts on said flow channel to thereby influence a flow resistance of the flow channel and to set the damping characteristic of said damper device. 
     
     
         3 . The door component according to  claim 2 , which further comprises a magnet device configured to generate the variable and second magnetic fields, said magnet device being composed at least partially of a hard magnetic material and at least one electrical coil which is disposed to create said variable magnetic field by way of at least one magnetic pulse generated by said at least one electric coil to set the second magnetic field generated by said hard magnetic material. 
     
     
         4 . The door component according to  claim 1 , wherein:
 said control device is configured to set said damping valve to the low damping action, such that said damping valve acts with the low damping action in the electrically deenergized state during a movement of the pivotable door.   
     
     
         5 . The door component according to  claim 2 , which further comprises an electrical coil configured to modulate the second magnetic field acting in the flow channel. 
     
     
         6 . The door component according to  claim 1 , which further comprises at least two electrical coils, including a first electrical coil for outputting magnetic pulses for setting a magnetization of a magnet device, and a second electrical coil for modulating a magnetic field of the magnet device in a flow channel of the damping valve. 
     
     
         7 . The door component according to  claim 1 , wherein said damping valve of said damper device is a mechanically settable hydraulic valve. 
     
     
         8 . The door component according to  claim 1 , wherein:
 said damper device comprises a piston unit and a cylinder unit surrounding said piston unit, and wherein said piston unit divides a cylinder volume into two chambers;   said piston unit is equipped with a first one-way valve and said two chambers are connected to one another by way of an external return channel that is equipped with at least one controllable magnetorheological damping valve, forming a one-way circuit in which the magnetorheological fluid flows in one given flow direction through said piston unit during a retraction of said piston unit and during a deployment of said piston unit.   
     
     
         9 . The door component according to  claim 8 , wherein said piston unit includes a continuous piston rod having two ends projecting outwardly out of said cylinder unit. 
     
     
         10 . The door component according to  claim 8 , wherein said two chambers include a first chamber connected to said damping valve, and a second chamber connected to said damping valve via a second one-way valve, and further comprising a compensation chamber having a preloaded compensation volume connected to said damping valve and to said second chamber. 
     
     
         11 . The door component according to  claim 8 , wherein said piston unit includes a first piston rod that extends through a first of said two chambers, and a second piston rod that extends through a second of said two chambers, and said first and second piston rods are each led out of said cylinder volume and/or said cylinder unit to the outside. 
     
     
         12 . The door component according to  claim 11 , wherein one of said piston rods is a telescopic rod having a first side fastened to a piston of said piston unit and a second side fixedly connected to said cylinder unit. 
     
     
         13 . The door component according to  claim 11 , wherein one of said two piston rods serves as an electrical connector unit, and wherein at least one connection cable is guided on said piston rod. 
     
     
         14 . The door component according to  claim 11 , wherein at least one of said two piston rods is displaceably received, outside said cylinder unit, in a tube that is formed with at least one slot. 
     
     
         15 . The door component according to  claim 14 , wherein said tube forms a part of one of said connector units. 
     
     
         16 . The door component according to  claim 11 , wherein said damper device comprises at least one measuring device, and wherein a part of said at least one measuring device is fastened to a piston rod of said piston unit. 
     
     
         17 . A method of damping a pivoting movement of a pivotable door of a motor vehicle, the method comprising:
 providing a damper device with a settable and controllable damping action;   damping the pivoting movement of the pivotable door in a controlled process at least partially between a closed position and an open position of the pivotable door;   electrically adjusting a damping valve of the damper device, and maintaining set damping characteristics of the damping valve in an electrically deenergized state of the damping valve;   providing a sensor device being a friction wheel disposed to detect a relative movement between the pivotable door and the motor vehicle and configured to detect an angular position of the pivotable door;   detecting the angular position of the pivotable door to determine whether the pivotable door is in the closed position or in the open position;   when the pivotable door is in the closed position, setting the damping valve to a low damping action relative to a high damping action such that the damper device acts on the pivotable door with the damping valve in the electrically deenergized state; and   when the pivotable door is in the open position, setting the damper device to the high damping action relative to the low damping action such that the damper device acts on the pivotable door with the damping valve in the electrically deenergized state.