Apparatus for preparing snow surface and method for controlling a hydraulic circulation between such an apparatus and a tractor

Abstract

The invention relates to an apparatus for snow surface preparation for attachment to a tractor, comprising a vibration plate and a hydraulically driven exciter device for driving the vibration plate, with the exciter device being connectable to a working hydraulic system of the tractor and being driven by the same in such a way that a closed hydraulic circulation is produced between exciter device and working hydraulic system. In order to reduce the risk of overload of the exciter device, a control device is provided which monitors at least one operating parameter of the hydraulic circulation and functionally disconnects the exciter device from the working hydraulic system depending on a predetermined limit value for the at least one operating parameter. The invention further relates to a method for controlling a hydraulic circulation between a working hydraulic system of a tractor and a hydraulically driven exciter device for a vibration plate of an apparatus for preparing the snow surface which can be attached to the tractor.

1 . An apparatus for snow surface preparation for attachment to a tractor, comprising; 
 a vibration plate;    a hydraulically driven exciter device for driving the vibration plate, with the exciter device being connectable to a working hydraulic system of the tractor and being driven by the same in such a way that a closed hydraulic circulation is produced between exciter device and working hydraulic system; and    a control device which monitors at least one operating parameter of the hydraulic circulation and functionally disconnects the exciter device from the working hydraulic system depending on a predetermined limit value for the at least one operating parameter.    
   
   
       2 . An apparatus according to  claim 1 , wherein the control device is configured to disconnect the exciter device from the working hydraulic system directly and without any creeping transition.  
   
   
       3 . An apparatus according to  claim 1 , wherein the control device is arranged to short-circuit the hydraulic circulation for disconnecting the exciter device from the working hydraulic system.  
   
   
       4 . An apparatus according to  claim 1 , wherein the control device comprises a sensor for monitoring the at least one operating parameter and a hydraulic valve for disconnecting the exciter device from the working hydraulic system.  
   
   
       5 . An apparatus according to  claim 4 , characterized in that the monitoring and the disconnection can be performed hydraulically.  
   
   
       6 . An apparatus according to  claim 4 , wherein the monitoring and/or the coupling can be performed electrically or electromagnetically.  
   
   
       7 . An apparatus according to  claim 1 , wherein at least one operating parameter is the hydraulic fluid flow of the hydraulic circulation.  
   
   
       8 . An apparatus according to  claim 1 , wherein the control device is arranged in the device for snow surface preparation.  
   
   
       9 . An apparatus according to  claim 1 , wherein after the disconnection of the exciter device the control device is configured to re-connect the same again to the working hydraulic system as soon as the state of the at least one operating parameter causing the disconnection is no longer present.  
   
   
       10 . An apparatus according to  claim 1 , wherein the working hydraulic system comprises an adjustable hydraulic pump and a display device is provided which displays the output of the hydraulic pump at which the control device disconnects the exciter device from the working hydraulic system.  
   
   
       11 . A method for controlling a hydraulic circulation between a working hydraulic system of a tractor and a hydraulically driven exciter device for a vibration plate of an apparatus for snow surface preparation which can be attached to the tractor, comprising the following steps: 
 monitoring at least one operating parameter of the hydraulic circulation;    verifying whether the value of the at least one operating parameter exceeds a predetermined maximum value; and functionally disconnecting the exciter device from the working hydraulic system when the value of the at least one operating parameter exceeds the predetermined maximum value.    
   
   
       12 . An apparatus according to  claim 2 , wherein the control device is arranged to short-circuit the hydraulic circulation for disconnecting the exciter device from the working hydraulic system.