Drilling tool

1. A drilling tool comprising:

a shaft having a longitudinal axis;

a seat disposed toward an axial end of the shaft;

a drill bit accommodated at the seat;

a clamping section, which is disposed on the shaft and interacts with the drill bit; and

a tensioning element which is disposed in the shaft and is axially displaceable with respect to the shaft, the tensioning element comprising an expanding section and a contact section, the expanding section being connected to the contact section;

wherein the expanding section interacts with the clamping section, and the contact section interacts with the drill bit;

the clamping section comprising a frustoconical inner surface;

the frustoconical inner surface expanding toward an axial end of the shaft;

the expanding section of the tensioning element comprising a frustoconical shape which is complementary to the inner surface of the clamping section.

2. The drilling tool according to claim 1 wherein:

the shaft comprises a bore which accommodates the tensioning element; and

upon axial displacement of the tensioning element with respect to the bore, the clamping section provides a radial clamping effect and an axial clamping effect with respect to the drill bit.

3. The drilling tool according to claim 1 , wherein the clamping section comprises a cylindrical outer surface which engages with the drill bit in a radial direction of the shaft.

4. The drilling tool according to claim 3 , wherein:

the clamping section comprises a frustoconical inner surface;

wherein the frustoconical inner surface expands toward an axial end of the shaft.

5. The drilling tool according to claim 1 , wherein:

the clamping section includes a cylindrical inner surface disposed axially adjacent to the frustoconical inner surface; and

the tensioning element includes a cylindrical outer surface disposed axially adjacent to the frustoconical shape of the expanding section.

6. The drilling tool according to claim 5 , wherein, upon axial displacement of the tensioning element with respect to the bore, the frustoconical shape of the expanding section clamping section is displaced past the frustoconical inner surface of the clamping section such that the cylindrical outer surface of the tensioning element abuts the cylindrical inner surface of the clamping section.

7. The drilling tool according to claim 1 , wherein the contact section is configured as a circumferentially extending collar.

8. The drilling tool according to claim 7 , wherein the circumferentially extending collar protrudes radially away from an axial end portion of the expanding section.

9. The drilling tool according to claim 8 , wherein the circumferentially extending collar is generally circular in cross-sectional shape.

10. The drilling tool according to claim 1 , wherein the drill bit includes a recess, within which the contact section comes to rest.

11. The drilling tool according to claim 10 , wherein the recess is generally circular in cross-sectional shape.

12. The drilling tool according to claim 10 , wherein the recess has an axial depth dimension which is greater than an axial thickness dimension of the contact section.

13. The drilling tool according to claim 1 , wherein:

the drill bit comprises a first entraining element; and

the shaft comprises a second entraining element;

wherein the first entraining element interacts with the second entraining element in a form-fitting manner.

14. The drilling tool according to claim 13 , wherein:

the first entraining element comprises a protrusion of the drill bit and extends in an axial direction; and

the second entraining element comprises a recess in the seat of the shaft;

wherein the protrusion engages with the recess.

15. The drilling tool according to claim 1 , wherein the drill bit has a generally annular shape.

16. The drilling tool according to claim 1 , comprising a coolant bore extending through the shaft and a coolant bore extending through the tensioning element, wherein the coolant bore of the shaft and the coolant bore of the tensioning element are in fluid communication with one another.

17. The drilling tool according to claim 1 , wherein the tensioning element comprises a tensioning screw which is screwed into the shaft.

18. A drilling tool comprising:

a shaft having a longitudinal axis;

a seat disposed toward an axial end of the shaft;

a drill bit accommodated at the seat;

a clamping section, which is disposed on the shaft and interacts with the drill bit; and

a tensioning element, which is disposed in the shaft and comprises an expanding section and a contact section;

wherein the expanding section interacts with the clamping section, and the contact section interacts with the drill bit;

the clamping section comprises a frustoconical inner surface;

wherein the frustoconical inner surface expands toward an axial end of the shaft;

the expanding section of the tensioning element comprises a frustoconical shape which is complementary to the inner surface of the clamping section;

the clamping section includes a cylindrical inner surface disposed axially adjacent to the frustoconical inner surface; and

the tensioning element includes a cylindrical outer surface disposed axially adjacent to the frustoconical shape of the expanding section;

wherein, upon axial displacement of the tensioning element with respect to the bore, the frustoconical shape of the expanding section clamping section is displaced past the frustoconical inner surface of the clamping section such that the cylindrical outer surface of the tensioning element abuts the cylindrical inner surface of the clamping section.