Method for the drilling, in particular percussion or rotary percussion drilling, of holes in soil or rock material and device therefor

Abstract

In a method for drilling holes in soil or rock material, wherein a borehole is formed by a drill bit by a percussive and/or rotational movement, a casing adjoining the drill bit is introduced into the borehole and material that is removed is introduced into the annular space formed between the outer circumference of the drill rod and the inner circumference of the casing via at least one passage opening formed between the drill bit and the casing, and is discharged from the borehole, the impact energy of the drill rod is applied to the drill bit via an adapter cooperating with the drill bit and a drill rod, and that the impact energy is applied to the drill bit partially via an impact shoulder of the adapter and partially via a threaded connection between the adapter and the drill bit.

1 . A method for drilling, in particular percussion or rotary percussion drilling, holes in soil or rock material, wherein a borehole is formed by a drill bit mounted on a drill rod assembly by a percussive and/or rotational movement, a casing adjoining the drill bit is introduced into the borehole by being pulled and/or struck, and material that is removed is introduced into the annular space formed between the outer circumference of the drill rod assembly and the inner circumference of the casing via at least one passage opening formed between the drill bit and the casing, and is discharged from the borehole, wherein that the impact energy of the drill rod assembly is applied to the drill bit via an adapter cooperating with the drill bit and the drill rod assembly, and that the impact energy is applied to the drill bit at least partially via an impact shoulder of the adapter and at least partially via a threaded connection between the adapter and the drill bit. 
     
     
         2 . The method according to  claim 1 , wherein that the adapter is coupled to the drill bit by screwing via a quick-acting screw thread connection. 
     
     
         3 . The method according to  claim 1 , wherein that the adapter is coupled to the drill rod assembly by screwing via a thread, in particular a thread having a smaller pitch than the threaded connection between the drill bit and the adapter. 
     
     
         4 . The method according to  claim 1 , wherein that flushing fluid is discharged during drilling through the tubular adapter and through cooperating openings provided in the drill bit. 
     
     
         5 . The method according to  claim 4 , wherein that flushing fluid is intermittently discharged during an engagement of the drill bit with the soil or rock material via a flush valve disposed in the adapter and controlled as a function of said engagement. 
     
     
         6 . The method according to  claim 1 , wherein that the impact energy, in addition, is at least partially applied to the casing via an impact shoulder formed on the drill bit. 
     
     
         7 . A device for drilling, in particular percussion or rotary percussion drilling, holes in soil or rock material, wherein a borehole is formed by a drill bit mounted on a drill rod assembly by a percussive and/or rotational movement, a casing adjoining the drill bit is introducible into the borehole by pulling and/or striking, and removed material is introducible into an annular space formed between the outer circumference of the drill rod assembly and the inner circumference of the casing via at least one passage opening formed between the drill bit and the casing, and is dischargeable from the borehole, wherein that an adapter cooperating with the drill rod assembly and the drill bit is provided, and that the adapter cooperates with the drill bit via an impact shoulder of the adapter and via a threaded connection provided between the adapter and the drill bit. 
     
     
         8 . The device according to  claim 7 , wherein that the adapter is coupled to the drill bit via a quick-acting screw thread connection. 
     
     
         9 . The device according to  claim 7 , wherein that the adapter is coupled to the drill rod assembly via a further thread having a pitch differing from that of the thread connection between the adapter and the drill bit, in particular a smaller pitch. 
     
     
         10 . The device according to  claim 7 , wherein the end face of the adapter facing the interior of the borehole is designed to be at least partially chamfered. 
     
     
         11 . The device according to  claim 7 , wherein the tubular adapter is formed with a passage opening for flushing fluid facing the interior of the borehole, and that the passage opening cooperates with openings for discharging flushing fluid, that are provided in the drill bit. 
     
     
         12 . The device according to  claim 7 , wherein an engagement-controlled flush valve is provided in the adapter. 
     
     
         13 . The device according to  claim 7 , wherein the drill bit comprises at least one impact shoulder for cooperating with the casing and, in particular, applying an impact stress on the casing. 
     
     
         14 . The device according to  claim 7 , wherein the casing is thickened in its end region facing the interior of the borehole and the thickened portion, in its end region facing away from the interior of the borehole, is designed complementary to an impact shoulder of the drill bit. 
     
     
         15 . The device according to  claim 7 , wherein the end region of the casing facing the interior of the borehole is designed with a depression, in particular an asymmetrically shaped depression.