Clamping system

Abstract

The invention relates relates to a clamping system for clamping an object (1), in particular for clamping a cutting tool in a machine tool, comprising an accommodating bore (4) for accommodating the object (1) to be clamped, a threaded bore, which extends in the wall of the accommodating bore (4) transversely to the longitudinal axis (12) of the accommodating bore (4), and a clamping screw (6), which can be screwed in the threaded bore in order to selectively clamp or release the object (1) in the accommodating bore (4) in accordance with the screwing position of the clamping screw (6). The invention further relates to an intermediate element (9), which is arranged between the clamping screw (6) and the object (1) such that the clamping screw (6) touches the object (1) to be clamped (1) not directly, but rather indirectly by means of the intermediate element (9). According to the invention, the threaded bore is preferably arranged eccentrically in relation to the accommodating bore (4).

Claims

1. A clamping system for clamping an object, comprising: a) an accommodating bore for accommodating the object to be clamped; b) a threaded bore which extends in a wall of the accommodating bore transversely to a longitudinal axis of the accommodating bore; c) a clamping screw which is screwable in the threaded bore in order to optionally clamp or release the object dependent upon a screwed position of the clamping screw in the accommodating bore; d) an intermediate element being arranged between the clamping screw and the object, so that the clamping screw does not directly touch the object to be clamped, but rather indirectly via the intermediate element; and e) the threaded bore being arranged offset eccentrically to a diameter of the accommodating bore, wherein the clamping screw has a cup socket at a free inserting end thereof, and the intermediate element has, on a side of the clamping screw, a ball head which is mounted in the cup socket of the clamping screw, so that the intermediate element is pivotable relative to the clamping screw.

2. The clamping system according to claim 1, wherein a) the intermediate element is pivotable in a first pivot plane relative to the clamping screw wherein the first pivot plane extends transversely to the accommodating bore, and b) the intermediate element is pivotable in a second pivot plane relative to the clamping screw wherein the second pivot plane extends parallel to the accommodating bore.

3. The clamping system according to claim 1, wherein the intermediate element is pivotable in all directions relative to the clamping screw.

4. The clamping system according to claim 3, wherein a) the intermediate element has a flattening on a side of the object to be clamped, b) an outer surface of the object to be clamped has a flattening, and c) in a clamped state of the object, the flattening on the intermediate element then lies in plane-parallel arrangement against the flattening on the object to be clamped.

5. The clamping system according to claim 4, wherein the flattening in the outer surface of the object to be clamped is inclined along the accommodating bore so that the object to be clamped widens along its flattening toward a free end thereof.

6. The clamping system according to claim 1, wherein the threaded bore extends in a plane which lies perpendicularly to the longitudinal axis of the accommodating bore.

7. The clamping system according to claim 6, wherein a longitudinal axis of the threaded bore does not intersect the longitudinal axis of the accommodating bore.

8. The clamping system according to claim 1, wherein perpendicular spacing between a longitudinal axis of the threaded bore and the diameter of the accommodating bore is greater than 1 mm and smaller than 5 mm.

9. The clamping system according to claim 1, wherein the clamping screw fixes the object to be clamped by use of the intermediate element against axial withdrawal from the accommodating bore.

10. The clamping system according to claim 1, wherein the clamping screw fixes the object to be clamped by use of the intermediate element against twisting about a longitudinal axis thereof.

11. The clamping system according to claim 1, wherein a) the accommodating bore is substantially cylindrical, and b) the intermediate element is made of a softer material than the object to be clamped, and c) the intermediate element is made of a softer material than the clamping screw, and d) the clamping screw, the intermediate element and the object to be clamped each consist of steel, and e) the clamping screw is a setscrew.

12. A machine tool having a clamping system according to claim 1 for clamping a cutting tool.

13. The machine according to claim 12, wherein the machine is a milling machine and the cutting tool is a milling tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantageous developments of the invention are disclosed in the subclaims or are described below in greater detail together with the description of the preferred exemplary embodiment of the invention, making reference to the drawings. In the drawings:

(2) FIG. 1 is a clamping system according to the invention in a longitudinal section along the longitudinal axis of the accommodating bore for the cutting tool to be clamped,

(3) FIG. 2A is a cross-sectional view through the inventive clamping system of FIG. 1 along the section line A-A in FIG. 1,

(4) FIG. 2B is another view according to FIG. 2A in another angular position of the clamped cutting tool,

(5) FIG. 3 is an enlarged detail view of FIG. 1, and

(6) FIG. 4 is an enlarged detail view of FIGS. 2A and 2B.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(7) The drawings show a preferred exemplary embodiment of an inventive clamping system for clamping a cutting tool 1 (e.g. milling tool) in a machine tool (e.g. milling machine).

(8) On the side of the machine tool, the inventive clamping system has a standard chuck 2 which can be mechanically connected to a spindle mount of the machine tool. The mechanical connection of the clamping system to the machine tool is however not essential to the invention and can also take place in another way than with the standard chuck 2.

(9) On the side opposite to the standard chuck 2, the inventive clamping system has an accommodating connecting piece 3 with an accommodating bore 4, wherein the cutting tool 1 is introduced axially into the accommodating bore 4 of the accommodating connecting piece 3 for clamping.

(10) Situated in the wall of the accommodating connecting piece 3 is a threaded bore 5 (see FIG. 3) into which a clamping screw 6 is screwed. In the exemplary embodiment shown, the clamping screw 6 has a hexagonal socket in its screw head, although the clamping screw 6 can also be constructed differently.

(11) At its free inserting end, the clamping screw 6 has a cup socket 7 (see FIG. 3), the cup socket 7 in the clamping screw 6 forming a pivot joint together with a ball head 8 of an intermediate element 9. The intermediate element 9 can thus be pivoted universally relative to the clamping screw 6.

(12) On the side facing away from the clamping screw 6, the intermediate element 9 has a flattening 10 which, in the clamped state lies in plane-parallel arrangement against a corresponding flattening 11 in the outer surface of the cutting tool 1.

(13) It is apparent from FIG. 1 that the flattening 11 in the outer surface of the cutting tool 1 is inclined relative to the longitudinal axis 12 of the accommodating bore 4, specifically in such a way that in the region of the flattening 11, the cutting tool 1 widens toward its free end. By means of this inclination of the flattening 11, it is achieved that the cutting tool 1 is securely fixed against an axial withdrawal.

(14) From FIGS. 2A, 2B and 4 it is also apparent that the threaded bore 5 for the clamping screw 6 has a longitudinal axis 13 which is eccentrically offset relative to a central diameter 14 of the accommodating bore 4. The perpendicular spacing between the longitudinal axis 13 of the threaded bore 5 and the central diameter 14 of the accommodating bore 4 in this exemplary embodiment amounts to d=2 mm. This eccentric arrangement of the clamping screw 6 has the result that the intermediate element 9 pivots relative to the clamping screw 6 on screwing in the clamping screw 6, wherein the plane-parallel contact of the flattening 10 of the intermediate element 9 against the flattening 11 in the outer surface of the cutting tool 1 is retained.

(15) In the angular position according to FIG. 2A, the cutting tool 1 has a value of 1=2. In this angular position, the spacing between the midpoint of the intermediate element 9 and the midpoint of the accommodating bore 4 a1=10.55 mm.

(16) In the angular position of the cutting tool 1 according to FIG. 2B, however, the corresponding angle 2=8, which corresponds to a spacing a2=10.44 mm.

(17) It is evident therefrom that a twisting of the cutting tool 1 about its longitudinal axis is only possible if the clamping screw 6 is loosened again. The inventive clamping system therefore fixes the cutting tool 1 not only against an axial withdrawal, but also against a rotation about the longitudinal axis 12.

(18) The invention is not restricted to the above-described preferred exemplary embodiment. Rather a plurality of variants and derivations is possible which also make use of the inventive concepts and therefore fall within the protective scope. In particular, the invention also claims protection for the subject matter and the features of the subclaims separately from the claims to which they each refer. For example, the invention also claims protection for the concept of an eccentric arrangement of the clamping screw separately from the intermediate element.

REFERENCE SIGNS

(19) 1 Cutting tool 2 Standard chuck 3 Accommodating connecting piece 4 Accommodating bore 5 Threaded bore 6 Clamping screw 7 Cup socket of the clamping screw 8 Ball head of the intermediate element 9 Intermediate element 10 Flattening on the intermediate element 11 Flattening in the outer surface of the cutting tool 12 Longitudinal axis of the accommodating bore 13 Longitudinal axis of the threaded bore 14 Diameter of the accommodating bore 1, 2 Angular position of the cutting tool d Offset between the longitudinal axis of the threaded bore and the diameter of the accommodating bore a1, a2 Spacing between central plane of the accommodating bore and the central point of the clamping ball