Drilling tool and method for producing a bore in the ground

Abstract

The invention relates to a drilling tool, in particular for discontinuous earth drilling, with a ground removal means which is arranged in a lower region of the drilling tool and is designed for removing ground material, a receiving space which is designed for receiving the removed ground material above the ground removal means on the drilling tool, at least one passageway which is designed for the passage of the removed ground material from the ground removal means into the receiving space during drilling, a closure means for closing the at least one passageway during withdrawal of the drilling tool from the borehole and a connecting means located in the upper region of the drilling tool for releasable connection with a drill rod. In accordance with the invention provision is made in that a tubular central shaft is designed with a compensating channel which extends from at least one lower channel opening which is arranged below or on the closure means up to at least one upper channel opening which is arranged above the receiving space, wherein the compensating channel is designed for the flowthrough of a medium between the lower region and the upper region of the drilling tool during withdrawal and/or lowering of the drilling tool in the borehole.

1 . Drilling tool, in particular for discontinuous earth drilling, with
 a ground removal means ( 20 ) which is arranged in a lower region of the drilling tool ( 10 ) and designed for removing ground material,   a receiving space ( 40 ) which is designed for receiving the removed ground material above the ground removal means ( 20 ) on the drilling tool ( 10 ),   at least one passageway ( 28 ) which is designed for the passage of the removed ground material from the ground removal means ( 20 ) into the receiving space during drilling,   a closure means ( 50 ) for closing the at least one passageway during withdrawal of the drilling tool ( 10 ) from the borehole and   a connecting means ( 45 ) located in the upper region of the drilling tool ( 10 ) for releasable connecting with a drill rod,   
       characterized in that
 a tubular central shaft ( 30 ) is designed with a compensating channel ( 32 ) which extends from at least one lower channel opening ( 34 ) which is arranged below or on the closure means ( 50 ) up to at least one upper channel opening ( 36 ) which is arranged above the receiving space ( 40 ), wherein the compensating channel ( 32 ) is designed for the flowthrough of a medium between the lower region and the upper region of the drilling tool ( 10 ) during withdrawal and/or lowering of the drilling tool ( 10 ) in the borehole. 
 
     
     
         2 . Drilling tool according to  claim 1 ,
 characterized in that   the lower channel opening ( 34 ) and/or the upper channel opening ( 36 ) is closable.   
     
     
         3 . Drilling tool according to  claim 1 ,
 characterized in that   the closure means ( 50 ) for closing the passageway ( 28 ) to the receiving space ( 40 ) is also designed for closing/opening the lower channel opening ( 34 ).   
     
     
         4 . Drilling tool according to  claim 1 ,
 characterized in that   the closure means ( 50 ) has a closure element ( 52 ) which is adjustable between a closure position, in which the passageway ( 28 ) to the receiving space ( 40 ) is closed by the closure element ( 52 ), and a drilling position, in which the passageway ( 28 ) is open for the passage of ground material into the receiving space ( 40 ) during drilling.   
     
     
         5 . Drilling tool according to  claim 4 ,
 characterized in that   in the drilling position of the closure element ( 52 ) the lower channel opening ( 34 ) is closed and   in that in the closure position of the closure element ( 52 ) the lower channel opening ( 34 ) is open.   
     
     
         6 . Drilling tool according to  claim 4 ,
 characterized in that   the closure element ( 52 ) is designed as a rotary bottom which can be rotated between the closure position and the drilling position.   
     
     
         7 . Drilling tool according to  claim 1 ,
 characterized in that   in an upper region of the receiving space ( 40 ) a cover ( 42 ), in particular a cover plate, is arranged which closes off the receiving space ( 40 ) in the upward direction and separates it from the upper channel opening ( 36 ).   
     
     
         8 . Drilling tool according to  claim 1 ,
 characterized in that   the connecting means ( 45 ) has a Kelly connection.   
     
     
         9 . Drilling tool according to  claim 1 ,
 characterized in that   the drilling tool ( 10 ) is designed as a drilling bucket with a circumferential wall which encloses the receiving space ( 40 ) in a housing-like manner.   
     
     
         10 . Drilling tool according  claim 1 ,
 characterized in that   the drilling tool ( 10 ) is designed as a drilling auger with at least one auger flight ( 14 ) which is arranged helically around the central shaft ( 30 ).   
     
     
         11 . Drilling apparatus,
 characterized in that   a drilling tool ( 10 ) according to  claim 1  is arranged.   
     
     
         12 . Method for producing a bore in the ground, in particular for discontinuous drilling,
 characterized in that   a drilling tool ( 10 ) according to  claim 1  is used.   
     
     
         13 . Method according to  claim 12 ,
 characterized in that   when removing ground material during drilling the passageway ( 28 ) to the receiving space ( 40 ) is opened and the lower channel opening ( 34 ) is closed.   
     
     
         14 . Method according to  claim 12 ,
 characterized in that   for withdrawal of the drilling tool ( 10 ) the passageway ( 28 ) to the receiving space ( 40 ) is closed and the lower channel opening ( 34 ) is opened.   
     
     
         15 . Method according to  claim 12 ,
 characterized in that   for the lowering of the drilling tool ( 10 ) into the borehole the compensating channel ( 32 ) is opened.