Abstract
The invention relates to a machine tool (1) comprising a clamping holder (10) which extends along a longitudinal axis (3) and a cutting element (20) that can be inserted into an open tool-side recess (40), which passes through the clamping holder (10), transversely to the longitudinal axis (3). The machine tool (1) has a stop (30) which is secured in the recess (40) and against which the cutting element (20) rests in the direction transverse to the longitudinal axis (3).
Claims
1. A machine tool, comprising: a clamping holder, which extends along a longitudinal axis, a cutting body that can be inserted into a recess, which passes through the clamping holder in a direction transversely to the longitudinal axis and which is open on a front side of the tool, and a stop, which is secured in the recess and against which the cutting body abuts in the direction transversely to the longitudinal axis.
2. The machine tool according to claim 1, wherein the stop is formed by means of a stop bolt, which is fastened to the clamping holder and which protrudes into the recess.
3. The machine tool according to claim 1, wherein a bearing surface on the cutting body abutting against the stop is formed in a recess overlapping the stop.
4. The machine tool according to claim 1, wherein the recess receives the cutting body in a positive manner.
5. The machine tool according to claim 1, wherein the recess has a cross section, which tapers in the direction of the front side of the tool.
6. The machine tool according to claim 1, wherein a cross section of the recess is defined by a flat base surface and two flat flank surfaces.
7. The machine tool according to claim 1, wherein the machine tool further comprises a clamping claw, which clamps the cutting body to the clamping holder.
8. The machine tool according to claim 7, wherein the clamping claw is formed from a first flank, which laterally limits the recess.
9. The machine tool according to claim 8, wherein the machine tool further comprises a slot, which separates the clamping claw from a base of the recess.
10. The machine tool according to claim 8, wherein the clamping claw can be tightened against a second flank by means of a clamping screw.
11. The machine tool according to claim 7, wherein a front side of a first flank that forms the clamping claw lies axially behind a front side of a second flank.
12. The machine tool according to claim 1, wherein the cutting body protrudes beyond the clamping holder on the front side of the tool.
13. The machine tool according to claim 1, wherein the clamping holder has an elliptical or symmetrically oval, non-round cross section, which is defined by a longer major axis and a shorter minor axis, at least for a length portion, which lies axially behind the recess, and the cutting body lies parallel or obliquely to a minor axis.
14. The machine tool according to claim 13, wherein compared to the minor axis, the cutting body lies so as to be rotated opposite to a cutting force direction.
15. The machine tool according to claim 1, wherein the machine tool further comprises a coolant/lubricant supply channel, which is guided through the clamping holder to the cutting body, comprising a mouth opening, which is aligned towards a cutting edge or cutting edges on the cutting body.
Description
[0030] A preferred embodiment of a machine tool according to the invention will be described below with the help of the enclosed drawings, in which:
[0031] FIG. 1 shows a top view of a machine tool according to the invention;
[0032] FIG. 2 shows a side view of the machine tool from FIG. 1;
[0033] FIG. 3 shows a front view of the machine tool from FIG. 1;
[0034] FIG. 4a shows a perspective view of a clamping part of the machine tool according to the invention from FIG. 1;
[0035] FIG. 4b shows a further perspective view of the clamping part of the machine tool according to the invention from FIG. 1;
[0036] FIG. 5 shows a side view of the clamping part from FIG. 4a;
[0037] FIG. 5a shows a sectional view along the line D-D from FIG. 5;
[0038] FIG. 6 shows a front view of the clamping part from FIG. 4a;
[0039] FIG. 6a shows a sectional view along the line F-F from FIG. 6;
[0040] FIG. 7 shows a further front view of the clamping part from FIG. 4a;
[0041] FIG. 7a shows a sectional view along the line J-J from FIG. 7;
[0042] FIG. 7b shows a sectional view along the line K-K from FIG. 7;
[0043] FIGS. 8a to 8d show top views of different cutting bodies;
[0044] FIGS. 9a to 9d show top views of the clamping part from FIG. 4a with inserted cutting body according to FIGS. 8a to 8d;
[0045] FIG. 10 shows a top view of the machine tool without cutting body;
[0046] FIG. 11 shows a side view of the machine tool without cutting body; and
[0047] FIG. 12 shows a front view of the machine tool without cutting body
[0048] FIGS. 1 to 3 show a machine tool 1 according to the invention in the form of a stationary, non-rotating grooving tool in different views. The grooving tool 1 has an elongate clamping holder 10, which extends along a longitudinal axis 3, a cutting body 20, which is clamped in the clamping holder 10 and which cuts circumferentially, and a stop 30, which is secured in the clamping holder 10 (see FIG. 6a in combination with 6). The expressions “left” or “front”, respectively, and “right” or “rear”, respectively, used below thereby refer to the top and side view of FIGS. 1 and 2.
[0049] As shown in FIGS. 1 and 2, the elongate clamping holder 10 is functionally divided into a shaft part 10c located in the rear, a clamping part 10a located in the front, and a connecting portion 10b, which connects the shaft part 10c and the clamping part 10a in the longitudinal direction. The shaft part 10c serves to connect the machine tool to a turning machine. As shown in FIGS. 4a to 5, the clamping part 10a has the clamped cutting body 20, which sits in a recess 40, which passes through the clamping part 10a and which is open on the front side of the tool (see FIG. 11). The recess 40, which is open on the front side of the tool, passes centrally through the clamping holder 10 or the clamping part 10a, respectively, perpendicularly to the longitudinal axis 3, i.e. beyond the longitudinal axis 3 (see FIG. 3). As shown in the side view in FIG. 11, the recess 40 is defined by means of a flat base surface 41 and two flat flank surfaces 42, 43. The base surface 41 runs perpendicularly to the longitudinal axis 3 of the clamping holder 10. The first flank surface 42 runs parallel to the longitudinal axis 3 and is arranged perpendicularly to the base surface 41. Compared to the base surface 41, the second flank surface 43 has an acute angle. Due to the second flank surface 43, which is arranged at an acute angle to the base surface 41, the recess 40 has a cross section, which tapers in the direction of the front side of the tool, as a result of which the cutting body 20, which is inserted into the recess 40, is secured in a positive manner in the axial direction.
[0050] As shown in particular in FIGS. 4b and 5, the clamping part 10a of the clamping holder 10 is divided into a first flank 13 and a second flank 15 by means of a slot 14. The first flank 13 forms a clamping claw 13, which is formed integrally with the clamping part 10a and which clamps the cutting body 20 in the recess 40 and has the first flank surface 42, which laterally limits the recess 40 (see FIGS. 10 to 12). The second flank 15 has the base surface 41 and the second flank surface 43, which is arranged at the acute angle to the base surface 41. The slot 14 is continuous in a direction transversely to the longitudinal axis 3 of the clamping holder 10, and extends in an axially parallel manner from the base or the base surface 41, respectively, of the recess 40 rearwards in the direction of the shaft part 10c. As shown in FIG. 11, the slot 14 is arranged outside of the base or of the base surface 41 of the recess 40, respectively. In other words, the slot 14 does not lead into the base surface 41 of the recess 40, but represents an “extension” of the first flank surface 42 in the direction of the shaft part 10c. The base or the base surface 41, respectively, of the recess 40 is not separated by the slot 14, as a result of which the cutting body 20 can abut over the entire surface against the base surface 41 and the second flank surface. 43. The base surface 41 and the second flank surface 43, which is arranged at an acute angle to the base surface 41, form a seat, which securely positions the cutting body 20.
[0051] As shown in FIGS. 4a and 4b, the clamping claw 13 can be tensioned against the second flank 14 by means of a clamping screw 16. A clamping of the cutting body 20 in the recess 40 by means of the clamping claw 13 can generally also be attained without the clamping screw 16. The use of the clamping screw 16, however, facilitates the assembly of the cutting body 20 in the recess 40, when clamping claw 13 and slot 14 are dimensioned accordingly. The distance between the two flank surfaces 42, 43 is in particular dimensioned in such a way that the cutting body can be laterally inserted into the recess 40 without canting when the clamping screw 16 is loosened. A subsequent tightening of the clamping screw 16 has the effect that the clamping claw 13 pushes with its first flank surface 42 against the cutting body 20 and fixes the latter in the recess 40.
[0052] As shown in FIG. 6a, the grooving tool 1 has a stop 30 according to the invention in the form of a stop bolt. The stop bolt 30 is axially secured in a rotationally fixed manner by means of a tight fit in a blind hole 31, which is formed in the base surface 41 (see FIG. 12) and which extends parallel to the longitudinal axis 3, and protrudes into the recess 40. When the cutting body 20 is laterally inserted into the into the recess 40, a bearing surface 22, which is formed in a recess 21 of the cutting body 20 overlapping the stop bolt 30 (see FIGS. 8a to 8d) bears against the stop bolt 30, so that the cutting body 20 is secured in a positionally accurate manner in the recess 40 in a direction transversely to the longitudinal axis 3.
[0053] In spite of the stop bolt 30, which protrudes into the recess 40, the recess 40 can be used over its entire length in its direction of extension to clamp the cutting body 20 by means of the clamping claw 13.
[0054] As shown in FIGS. 4a and 5, the clamping part 10a of the clamping holder 10 is formed in such a way that a front side 13a of the first flank 13 forming the clamping claw 13 lies axially behind a front side 15a of the second flank 15. In other words, the cutting body 20, which is inserted into the recess 40, protrudes axially beyond the front side 13a of the clamping claw 13. On its top side, the cutting body 20, which cuts circumferentially, thus keeps free a chip surface for the chips resulting during the workpiece machining. An obstruction of the chip flow by means of the clamping claw 13 can thus be prevented for the most part.
[0055] As shown in FIG. 5a, a length portion of the clamping part 10a located axially behind the recess 40 has an elliptical cross section, which is defined by a longer major axis HA and a shorter minor axis NA. Compared to the minor axis NA, the cutting body 20 lies so as to be rotated opposite to the cutting force direction of the cutting body 20 (see FIGS. 3, 6, and 7). Compared to a clamping holder or clamping part, respectively, with a round cross section, the diameter of which corresponds to the length of the minor axis NA of the clamping part 10a, which has an elliptical cross section, the clamping part 10a with elliptical cross section has more material for supporting the cutting body 20 in the region supporting the cutting body 10 in FIG. 11 below the second flank surface 43, due to the elliptical shape. The stability of the clamping part 10a is thus increased. Due to the rotation of the cutting body 20 in a direction opposite to the cutting force direction of the cutting body 20 with respect to the minor axis NA, the bearing surface of the cutting body 20 at the second flank 15 is increased, which leads to a further increase of the stability. The torque acting on the cutting body 20 and thus the stress thereto can furthermore be reduced. The cross sections of the connecting portion 10b and of the shaft part 10c are essentially round in terms of a simple manufacturing.
[0056] As shown in the sectional views in FIGS. 7a and 7b, the grooving tool 1 has a coolant/lubricant supply channel 50, which is guided through the clamping holder 10 to the cutting body 20, comprising a mouth opening 51, which is aligned towards the cutting edge on the cutting body 20. The coolant/lubricant supply channel 50 runs within the clamping claws 13 in the clamping part 10a.
[0057] FIGS. 8a to 8d show different circumferentially cutting cutting bodies 20 comprising recess 21 and bearing surface 22 for bearing against the stop bolt 30 in the recess 40 of the clamping part 10a. FIGS. 9a to 9d show top views of the clamping part 10a comprising inserted cutting bodies 20 according to FIGS. 8a to 8d. Cutting bodies 20 with different shapes and geometries can be inserted into the recess 40 of the clamping part 10a of the grooving tool 1 according to the invention, and can be positioned in a positionally accurate manner in a direction transversely to the longitudinal axis 3 by means of the stop 30 according to the invention.
[0058] It goes without saying that modifications of the above-described exemplary embodiment are possible, without leaving the basic idea of the invention defined by the claims.
