Two-part drilling tool for the percussive or rotary percussive drilling of holes in soil material or rock material

Abstract

In a two-part drilling tool for the percussive or rotary percussive drilling of holes in soil material or rock material, including a drill head ( 1 ) and an adapter part ( 7 ), which is fixed in an interior of the drill head ( 1 ) by way of interacting, complementary threads ( 11, 14 ) and is intended for providing the coupling to a drill string, wherein an end face ( 3 ) of the drill head ( 1 ) that is remote from a borehole interior rests on a complementarily formed stop or support surface of the adapter part ( 7 ), the end face ( 3 ) of the drill head ( 1 ) that is remote from the borehole interior and the stop or support surface of the adapter part ( 7 ) interacting therewith comprise complementarily formed wedge-shaped surfaces ( 4, 6 ) with end teeth ( 5, 8 ), and a lead angle (α 1 ) of the wedge-shaped surfaces ( 4, 6 ) is smaller than a lead angle (α 2 ) of an internal thread of the drill head ( 1 ) or the external thread interacting therewith of the adapter part ( 7 ) or of the drill string.

1 . A two-part drilling tool for the percussive or rotary percussive drilling of holes in soil material or rock material, including a drill head and an adapter part, which is fixed in an interior of the drill head by way of interacting, complementary threads and is intended for providing the coupling to a drill string, wherein an end face of the drill head that is remote from a borehole interior rests on a complementarily formed stop or support surface of the adapter part, characterized in that the end face of the drill head that is remote from the borehole interior and the stop or support surface of the adapter part interacting therewith are configured as complementarily formed wedge-shaped surfaces with end teeth, wherein, in the main, the wedge-shaped surfaces take up the impact stress and the end faces take up the torques, and that the lead angle of the wedge-shaped surfaces is smaller than the lead angle of the internal thread of the drill head, or the external thread interacting therewith of the adapter part. 
     
     
         2 . The two-part drilling tool according to  claim 1 , characterized in that the lead angle of the wedge-shaped surfaces is at least 10% and at most 50%, in particular about 25%, smaller than the lead angle of the internal and external threads. 
     
     
         3 . The two-part drilling tool according to  claim 1 , characterized in that thread roots of the complementary threads of the drill head and the adapter, or the drill rod, each extending in the axial direction of the two-part drilling tool in the axial direction of the two-part drilling tool have dimensions exceeding those of the thread heads. 
     
     
         4 . The two-part drilling tool according to  claim 3 , characterized in that the thread root exceeds the dimension of the thread head in the axial direction of the two-part drilling tool by at least one third of the height of the end teeth. 
     
     
         5 . The two-part drilling tool according to  claim 1 , characterized in that the end faces of the adapter and the stop or support surface of the drill head each comprise at least one, in particular at least three, wedge-shaped surface(s) with end teeth. 
     
     
         6 . The two-part drilling tool according to  claim 1 , characterized in that at least the wedge-shaped surfaces of the adapter are case-hardened. 
     
     
         7 . The two-part drilling tool according to  claim 6 , characterized in that the wedge-shaped surfaces and the end teeth of the adapter are case-hardened. 
     
     
         8 . The two-part drilling tool according to  claim 1 , characterized in that approximately semicircular recesses are each formed in the region of the end teeth, both in the adapter and in the stop or support surface of the drill head. 
     
     
         9 . The two-part drilling tool according to  claim 1 , characterized in that the internal thread and the complementary external thread interacting therewith are designed as single-flight threads. 
     
     
         10 . The two-part drilling tool according to  claim 1 , characterized in that the respective turns of the threads of the drill head and the adapter extend over at least 75% and at most 99% of the circumferences of the adapter and the drill head. 
     
     
         11 . The two-part drilling tool according to  claim 10 , characterized in that the complementary threads are designed as flat threads or trapezoidal threads having flank angles smaller than 25°.