Abstract
A tool holder for a machine tool, having a retaining component which can be rotated about an axis of rotation and on which a cutting tool is or can be fastened in a releasable manner, wherein the retaining component has at least two plug-in mounts, which are offset in the circumferential direction about the axis of rotation and are intended for receiving a respective cutting tool, having an elongate plug-in shank and a cutting portion, wherein each cutting tool is or can be fixed in the plug-in mount via a separate retaining device, and wherein the cutting tools delimit between them a receiving space for a workpiece which can be machined by the cutting tools together, the cutting tools having their cutting portions facing toward the receiving space.
Claims
1. A tool holder for a machine tool, having a retaining component which can be rotated about an axis of rotation and on which a cutting tool is or can be fastened in a releasable manner, characterized in that the retaining component has at least two plug-in mounts, which are offset in the circumferential direction about the axis of rotation and are intended for receiving a respective cutting tool, having an elongate plug-in shank and a cutting portion, wherein each cutting tool is or can be fixed in the plug-in mount via a separate retaining means, and wherein the cutting tools delimit between them a receiving space for a workpiece which can be machined by the cutting tools together, the cutting tools having their cutting portions facing toward the receiving space.
2. The tool holder according to claim 1, comprising the provision of three plug-in mounts, which are offset preferably equidistantly by 120 in the circumferential direction, or four plug-in mounts, which are offset preferably equidistantly by 90 in the circumferential direction.
3. The tool holder according to claim 1, wherein each plug-in mount is delimited via at least one clamping portion, against which the plug-in shank of the respective cutting tool is or can be clamped via the retaining means, or in that the plug-in shanks are braced in relation to one another via the retaining means.
4. The tool holder according to claim 1, wherein the plug-in mounts merge into one another in the direction of the axis of rotation to form a common depression.
5. The tool holder according to claim 4, wherein the depression, for the purpose of forming the respective plug-in mount, has a radial widening in the direction of the outer side of the retaining component.
6. The tool holder according to claim 5, wherein the cross section of the widening is shape-compatible in relation to a cross-sectional portion of the cutting tool.
7. The tool holder according to claim 6, wherein each radial widening is formed via a hole portion.
8. The tool holder according to claim 7, wherein each hole portion extends over more than 180 and the end edges of each hole portion form the clamping portions, against which it is possible for the respective plug-in shank, which is cross-sectionally shape-compatible with the hole portion, can be clamped via the retaining means.
9. The tool holder according to claim 4, wherein each plug-in shank has at least one supporting surface, preferably two supporting surfaces which are located at an angle in relation to one another and via which the plug-in shanks are braced and supported radially in relation to one another.
10. The tool holder according to claim 1, comprising the provision, on the retaining component, of a number of threaded holes, this number corresponding to the number of plug-in mounts, which open out in each case on an outer surface of the retaining component and of a plug-in mount and into which a respective retaining means, in the form of a retaining screw which runs against the plug-in shank, is or can be screwed.
11. The tool holder according to claim 10, wherein each threaded hole runs at an angle ()<90 in relation to the axis of rotation.
12. The tool holder according to claim 10, comprising the provision, on each plug-in shank, of a planar run-on surface, against which the retaining screw runs perpendicularly.
13. The tool holder according to claim 12, wherein each threaded hole opens out on the outer surface of a planar screw-in surface.
14. The tool holder according to claim 10, wherein the threaded hole is a countersunk hole.
15. The tool holder according to claim 1, wherein the cutting portions of the cutting tools are designed for the turning of a pin-like workpiece for the purpose of forming a cylindrical workpiece surface.
16. A machine tool comprising a drive device with a receiving means which can be rotated about an axis of rotation, and also comprising a tool holder according to claim 1, the tool holder being received or receivable in the receiving means and the axis of rotation thereof coinciding with the axis of rotation of the receiving means.
Description
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIG. 1 shows a perspective view of a tool holder according to the invention comprising a retaining component and also cutting tools secured thereon,
[0023] FIG. 2 shows a side view of the retaining component,
[0024] FIG. 3 shows a front-side view in the direction of arrow III from FIG. 2,
[0025] FIG. 4 shows a sectional view in the direction of line IV-IV from FIG. 3,
[0026] FIG. 5 shows a sectional view through the retaining component along line V-V from FIG. 2, with cutting tools inserted,
[0027] FIG. 6 shows a side view of a cutting tool,
[0028] FIG. 7 shows a view of the cutting tool from FIG. 6 in the direction of arrow VII,
[0029] FIG. 8 shows a plan view of three cutting tools located in the insertion position, but without a retaining component,
[0030] FIG. 9 shows a perspective detail-form view of three cutting tools, with an illustration given of the retaining screws,
[0031] FIG. 10 shows a schematic diagram of the arrangement of two cutting tools, each in respect of their plug-in shanks,
[0032] FIG. 11 shows a schematic diagram of four cutting tools, each in respect of their plug-in shanks, and
[0033] FIG. 12 shows a schematic diagram of five cutting tools, each in respect of their plug-in shanks.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1 shows a tool holder 1 according to the invention which can be connected in a manner known per se via a correspondingly designed fastening interface 2, for example a hollow shank taper interface or steep taper interface, to a holder mount of a drive unit of a machine tool. The tool holder 1 comprises a retaining component 3, on which the installation interface 2 is provided. In the example shown, a total of four separate plug-in mounts 4 are provided on the retaining component 3, whichsee FIG. 3can be rotated, in the installed position, about a central axis of rotation R, and a respective cutting tool 5 is inserted into the plug-in mounts by way of a plug-in shank 6 (see, in this respect, also FIGS. 5, 6 and 9) and is fixed via a suitable retaining means. The retaining mounts 4 are located on an identical pitch circle in the circumferential direction and are distributedin the example shownequidistantly about the axis of rotation R, to give a separation of 120. Each cutting tool 5 here has a cutting extension 7, which adjoins the plug-in portion and on which a respective cutting portion 8 in the form of a cutting edge is formed. The cutting portions 8, that is to say the cutting edges, are spaced apart from one another and delimit between them an accommodating space 9, into which a pin-like or stud-like workpiece to be machined is introduced, so that it can be machined, in particular turned, via the cutting portions 8, that is to say the cutting edges.
[0035] As FIGS. 2 and 3 show, the end side of the retaining component 3 is provided with a corresponding depression 10, wherein this depression 10 is formed by means of three separate holes, wherein these holes, which are offset equidistantly by 120 about the axis of rotation R, overlap to give the shape of depression shown in FIG. 3. The plug-in mounts 4 here are formed in part via corresponding radial widenings and, as they result from the respective hole, they are inevitably rounded in cross section. A plug-in shank 6, which, as far as the rounded shape of the radial widenings is concerned, is of correspondingly shape-compatible design, is plugged into each of these rounded plug-in mounts 4, and a type of form fit is achieved as a result. In the direction of the center of the common depression 10, the plug-in portions are of appropriately planar-surface design, which will be discussed in more detail hereinbelow, and this also results more or less in a form fit there.
[0036] Opening out in each plug-in mount 4 is a threaded hole 11, which opens out on the outer side of the retaining component 3, specifically on a planar screw-in surface 12 there. Each threaded hole 11 heresee, in particular, FIG. 4runs at an angle in relation to the axis of rotation R, which is only indicated in FIG. 4, where is <90. This means that the longitudinal axis of each threaded hole 11 is inclined slightly and runs in each case in the direction of a base 13 of each plug-in mount 4, as a result of which each plug-in shank 6, and therefore each cutting tool 5, is braced axially in relation to the respective base 13 of the respective plug-in mount 4 as a result of the retaining screws, which will be described in more detail hereinbelow, being screwed in.
[0037] FIG. 5 shows a sectional view through the retaining component 3 in the direction of line V-V in FIG. 2, an illustration being given here of the inserted cutting tools 5 or plug-in shanks 6. On the one hand, the figure shows the common depression 10 and also the corresponding plug-in mounts 4, each defined via the respective radial widenings. It can be seen that the plug-in mounts 4 are formed via separate, axially running holes, which overlap one another to form the common depression 10. In addition, the figure shows the respective plug-in shanks 6 of the three cutting tools 5 received, and it can be seen that this results in a respective form-fit geometry in relation to the rounded widenings. In the direction of the axis of rotation R, each plug-in shank 6 has two corresponding surfaces 14, which enclose between them an angle of 120, as is indicated in FIG. 5.
[0038] FIG. 5 also shows that each plug-in mount 4 has its rounded widening surrounding the respective plug-in shank 6 by an angle>180. This means that the respective hole wall of the respective plug-in mount 4 engages by more than 180 around each plug-in shank 6 by more than 180. Accordingly, each plug-in mount 4, which is formed via a corresponding hole portion 15 (corresponding to a widening), has two end edges 16 serving as clamping portions, against which each plug-in shank 6 is clamped radially via the respective retaining screw. This means that the end edges 16 form corresponding clamping portions, resulting from the surround by more than 180, via which radial clamping portions can be realized in a straightforward manner. Each plug-in shank 6 is received in the respective plug-in mount 4 with a minimal amount of play of preferably a few hundredths of a millimeter, so that straightforward axial insertion is possible on account of the small amount of play, but at the same time it is also the case that complete, fixed-position bracing via a respective retaining screw is possible in a very straightforward manner since all that is required for bracing purposes is for a minimal amount of play in relation to the respective end edges 15, that is to say the clamping portions, to be bridged.
[0039] FIGS. 6 and 7 respectively show a side view and a front-side view of a cutting tool 5. It is possible to see the respective plug-in shank 6 and also the adjoining cutting extension 7. As the figures show, each plug-in shank 6 is designed, on one side, with a corresponding partially cylindrical shank surface 17, which corresponds to the geometry of the hole portions 15 of the plug-in mounts 4. The respective partially cylindrical shank surfaces 17 are adjoined by the two planar shank surfaces 14, which form between them the angle , as already described in relation to FIG. 5.
[0040] FIG. 8 shows a plan view of the arrangement of the three cutting tools according to the exemplary embodiment from FIG. 5. Also illustrated are the respective cutting portions 8 in the form of the respective cutting edges, which delimit between them the receiving space 9.
[0041] FIG. 9 shows a detail-form view of the three cuttings tools 5 with their plug-in shanks 6 in the installed position, wherein, to aid clarity, the retaining component has not been shown. Each plug-in shank 6 has a planar run-on surface 18, adjacent to which, in the insertion position, the respective threaded hole 11 opens out. Also shown are the respective retaining screws 19, which are screwed into the respective threaded holes 11 and which run against the run-on surfaces 18. The run-on surfaces 18 likewise run at an angle in relation to the axis of rotation R, wherein the corresponding angle ultimately corresponds to the angle , at which the threaded holes 11 are inclined, so that each retaining screw 19 runs vertically onto the respective run-on surface 18. On the one hand, this provides for locking in the axial direction, that is to say that axial movement is completely ruled out by the abutting retaining screws 19. In addition, these oblique positions both of the threaded holes 11 and of the run-on surfaces 18 give rise to an axial force component in the direction of the respective base 13 of the plug-in mounts 4 and also a radial force component in the direction of the end edges 16, so that the screwing action clamps the plug-in shanks 6 both axially against the base surfaces 13 and radially against the end edges 16.
[0042] In order for the retaining component 3 to be fitted out, all that is required is for the three cutting tools 5 to be plugged, by way of their plug-in shanks 6, into the corresponding plug-in mounts 4. Incorrect positioning is ruled out as a result of the cross sections of the plug-in shanks 6 and the cross sections of the plug-in mounts 4 being shape-compatible. The plug-in shanks 6, which are received with a minimal amount of play in the plug-in mounts 4, are then braced by virtue of the respective retaining screws 19 being straightforwardly screwed into the threaded holes 11 and screwed against the plug-in shanks 6, which simultaneously achieves both radial bracing, in the direction of the axis of rotation, against the end edges 16 of the plug-in mounts 4 and/or of the hole portions 15 and axial bracing against the respective base 13 of the plug-in mounts 4. Since all the plug-in mounts 4, as well as the geometries thereof, are rotationally symmetrical and distributed preferably equidistantly in relation to the axis of rotation, it is therefore the case that the cutting portions 8, that is to say the respective cutting edges which subject the workpiece to machining action, are automatically positioned precisely in relation to one another by the cutting tools 5 being braced. The planar surfaces 14 of the plug-in shanks 6 do not come into contact with one another here since, as described, the plug-in shanks 6 are supported radially on the end edges 16, that is to say the corresponding clamping portions of each plug-in mount 4 or of each hole portion 15. A minimal amount of play of only a few hundredths of a millimeter remains.
[0043] In the example shown, three plug-in mounts 4, for the purpose of retaining three cutting tools 5, are provided on the retaining component 3. FIGS. 10, 11 and 12 show embodiments which illustrate, in principle, different numbers of plug-in mounts 4, and therefore of cutting tools 5. These figures each show the plug-in shanks 6, and also the geometry thereof, in cross section, wherein this cross-sectional geometry is the same cross-sectional geometry as that of the respectively associated plug-in mount 4.
[0044] In the example according to FIG. 10, two plug-in mounts 4, and accordingly two cutting tools 5, can be positioned on the retaining component 3. The plug-in mounts 4 are located on the same pitch circle, offset by 180 about the axis of rotation R. Each plug-in shank 6 is essentially cylindrical; here too, the mutually facing surfaces are planar. Here too, the plug-in mounts 4 or the hole portions 15 have a surround angle of more than 180, so that the respective end edges 16 of the respective hole portions 15, once again, form the clamping portions, against which the plug-in shanks 6 are clamped.
[0045] Four plug-in mounts 4 for four cutting tools 5 are shown for the exemplary embodiment according to FIG. 11. The plug-in shanks 6, once again, have corresponding, shape-compatible, partially cylindrical shank surfaces, each merging into two supporting surfaces, which are located at an angle of 90 in relation to one another and by way of which, in the example shown, the plug-in shanks 6 are supported in relation to one another, since in this case there is a surround angle of less than 180. It is therefore the case here that the plug-in shanks 6 support one another directly. It is also the case here that the extremely small amount of play of only a few hundredths of a millimeter readily provides for precise positioning of all the cutting tools 5 in relation to one another.
[0046] Finally, FIG. 12 shows a variant with five plug-in mounts 4 for five cutting tools 5, in the case of which, once again, there is a corresponding, shape-compatible geometry in relation to the respective plug-in mounts 4 on the plug-in shank 6. The planar supporting surfaces here are at an angle of 72 in relation to one another and, here too, supported one another, since the smaller surround angle means that there are no end edges serving as clamping surfaces.
[0047] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
