Tool for machining

Abstract

The present invention relates to a tool for machining, comprising a basic support (10), a carrier box-shaped part (11), a clamping jaw (12) and a clamping support (13), wherein the clamping support includes a receiving opening (25) for releasably clamping a cutting blade (14), the receiving opening being defined by a lower clamping jaw (22), an opposing upper clamping jaw (23) and a rear stop (24), and wherein in the rear region of the receiving opening, next to the rear stop (24), a first slot (28) and a gap (29) are connected, and by virtue of the formation of the first slot and the gap, the upper clamping jaw (23) can be opened relative to the lower clamping jaw (22), characterized in that in the region above the gap, a plurality of second slots formed as arcs or as open polygonal curves are connected, the second slots extending in a leftwardly curved manner at an angle of at least 120° when viewed from the front, and the tool ensuring sufficient stability during machining.

Description

Technical Field

[0001] The present invention relates to a tool, including a basic support, a carrier box-shaped member, a clamping pliers, and a clamping support. The clamping support includes a receiving opening for releasably clamping a cutting blade. The receiving opening is defined by a lower clamping jaw, an upper clamping jaw opposite to the lower clamping jaw, and a rear stop portion. Wherein, in the rear region of the receiving opening, adjacent to the rear stop portion, there is a slot and a widened portion. By the configuration of the slot and the widened portion, the upper clamping jaw can be opened relative to the lower clamping jaw. Background Art

[0002] Such tools are especially needed for cutting blades, which are used for punching and longitudinal turning, as well as for cutting and separating processes on rotating workpieces. The cutting blade that suffers wear during cutting must be replaced at the latest when, due to wear, the manufacturing accuracy required during cutting is no longer ensured. If the cutting edge breaks due to increased wear, this can lead to the workpiece being unusable during continued cutting.

[0003] Therefore, in order to be able to achieve automatic clamping stress of the cutting blade, simple replacement and loading, and on the other hand ensure optimized retention, a grooving tool including a receiving opening is proposed in DE 32 19 150 C3. Wherein, a rear widened gap is provided, and the gap forms a narrow bridge to the upper edge of the upper clamping jaw, so that the cutting pressure causes a proportional increase in the clamping stress through the lever-like deflection of the upper clamping jaw. The clamping surface of the upper clamping jaw should be slightly raised inward relative to the clamping surface of the cutting blade. In order to remove the cutting blade by opening the clamping legs, an elliptical key is inserted into the rear widened gap and the upper clamping jaw is opened by corresponding torsion.

[0004] DE 39 06 822 C3 also describes a support, which includes a receiving opening determined by a lower clamping jaw, an upper clamping jaw, and a rear stop portion. The receiving opening is adjacent to an L-shaped slot. In the bending region of the L-shaped slot, an elliptical shape is selected, which serves as a guiding device for an opening key having a cross-sectional profile for the ellipse when opening the clamping jaws.

[0005] A cutting insert clamping bracket is described in DE 199 55 581 B4, which has a lower base jaw and an elastically expandable upper clamping jaw. The clamping jaws together with a rear stop form a receiving opening for the cutting insert. The upper clamping arm has two clamping surfaces interrupted by a gap. A wide L-shaped opening extends above the rear stop; another opening should be below the rear stop. The upper L-shaped opening is constructed such that it extends in an upward and forward direction, thereby creating on the one hand a narrow bridging section to the upper edge of the upper clamping arm and a narrow second bridging section between the forward extending part and the rear clamping surface. Such a structure has the disadvantage due to the delicate configuration of the bridging section that the cutting insert cannot be held reliably.

[0006] Other known embodiments according to the prior art (wherein a narrow slot extends in the rear region of the receiving opening, which slot should ensure the elasticity of the upper clamping jaw) have the disadvantage that chips adhere in the slot, which can lead to malfunctions of the tool. Summary of the Invention

[0007] The object of the present invention is to provide a tool of the type initially described, which ensures sufficient stability during cutting, high elasticity of the upper clamping jaw, and optimized positioning of the clamped cutting insert. The clamping bracket should moreover be able to be manufactured inexpensively.

[0008] To solve this object, a tool for cutting is proposed according to the invention, which tool comprises a basic support, a carrier box part, clamping jaws, and a clamping bracket having a receiving opening for releasably clamping a cutting insert, the receiving opening being defined by a lower clamping jaw, an upper clamping jaw opposite the lower clamping jaw, and a rear stop, wherein in the rear region of the receiving opening, a first slot and a gap adjoin next to the rear stop, and by forming the first slot and the gap, the upper clamping jaw can be opened relative to the lower clamping jaw, and in the upper region of the gap, a plurality of second slots are formed as arcs or as open polygonal curves, which second slots extend in a leftwardly curved manner at an angle of at least 120° when viewed from the front.

[0009] According to the invention, at least one slot formed as an arc or as an open polygonal curve adjoins a slot formed at a short distance and an enlargement in its upper rear region, which slot extends in a leftwardly curved manner at an angle of at least 120° when viewed from the front. In other words, the slot formed as an arc or as a polygonal curve extends in its continuation in the direction of the front end of the clamping slot.

[0010] Preferably, the angle of the slot designed in the shape of an arc or a polygon extends up to 180°.

[0011] The elasticity of the upper clamping finger can be improved by providing 1 to 20, preferably 3 to 5, arcuate or polygonal curved slots which extend parallel to one another. In the case of a plate-shaped configuration of the clamping support, such arcuate or polygonal curved slots can be easily produced by laser etching, wherein, if necessary, a plurality of clamping supports stacked one on top of the other can be processed simultaneously. By means of the widening behind the stop for the cutting insert, a sufficiently large space is provided through which the chips can be easily discharged, so that the chips do not reach the area where the arcuate or polygonal curved slots are provided at all. A semicircular configuration of the slots which can be easily produced is preferred, which on the one hand enables an optimized elasticity of the upper clamping arm and on the other hand prevents narrow bridges in the area of ​​the upper clamping arm which can lead to unstable holding of the cutting insert during cutting.

[0012] The width of the arcuate or polygonal curved slot or the plurality of arcuate or polygonal curved slots should preferably be between 0.1 mm and 3 mm.

[0013] In particular, the arcuate slot or the uppermost arcuate slot of the plurality of slots should extend partially above a clamping plane defined by the clamping jaws, in particular the upper clamping jaw.

[0014] According to a further development of the present invention, the clamping bracket is plate-shaped and has a plurality of, preferably three, through-holes provided with countersunk holes for guiding through the fastening screw. The clamping bracket is threadedly connected to the carrier box-shaped part in this case, which is fastened to the basic bracket. By this measure, the clamping bracket can be taken out separately, for example, when the clamping bracket is worn and must be replaced due to strong mechanical stress during cutting. The separate configuration of the basic bracket, the carrier box-shaped part and the clamping bracket also provides the possibility that the clamping bracket is manufactured by a wear-resistant material, for example, by high-quality chrome steel. The carrier box-shaped part and the basic bracket can be manufactured by simple, cheaper steel in contrast, which minimizes the total cost as a whole.

[0015] According to another embodiment of the invention, the clamping support can have a coolant channel for a coolant in the upper clamping jaw. The coolant channel opens into the front side of the clamping jaw, which ensures that the coolant can be directed in a targeted manner into the cutting area.

[0016] If necessary, using the same support and the same supporting box, a clamping support with a greater width than shown can also be used. When selecting the clamping support, the width of the slot to be processed should be taken into account.

[0017] Preferably, the clamping bracket is threadedly connected to the load-bearing box-shaped part. The front side of the load-bearing box-shaped part forms a bearing surface for the plane of the clamping bracket, and its back side has a toothed profile with grooves. The teeth of the toothed profile are arranged obliquely with respect to the longitudinal axis or the transverse axis, preferably at an angle of 45°. Wherein, the basic bracket has a corresponding toothed profile on the side facing the load-bearing box-shaped part, and the toothed profile of the basic bracket is form-fittingly engaged into the toothed profile of the load-bearing box-shaped part in the assembled state. Through this design, it is possible to better support the forces that occur not only in the vertical direction but also in the transverse direction during the grooving operation.

[0018] In order to ensure an optimized orientation of the tool components with respect to each other, the load-bearing box-shaped part has an intermediate gap on its back side, and the gap is used for releasably receiving a sliding key, and the sliding key serves as a stop for accurately positioning the load-bearing box-shaped part with respect to the basic bracket of the tool. Description of the Drawings

[0019] Other designs and advantages of the present invention are illustrated with the aid of the drawings. Shown in the figures are:

[0020] Figure 1 A schematic view showing a complete tool, which includes a basic bracket, a load-bearing box-shaped part, and a clamping bracket with a clamped cutting blade;

[0021] Figure 2 The same view showing no cutting blade and no clamping pliers;

[0022] Figure 3 A schematic view showing the basic bracket with the assembled load-bearing box-shaped part;

[0023] Figure 4 A schematic view showing the basic bracket with the inserted sliding key;

[0024] Figure 5 A schematic view showing the back side of the load-bearing box-shaped part;

[0025] Figure 6 A schematic view showing the back side of the clamping bracket;

[0026] Figure 7 A perspective view showing the clamping pliers, and

[0027] Figure 8 A exploded view showing the complete tool. Detailed Description of the Invention

[0028] The basic tool holder is known in principle from the prior art and includes a connection on the machine tool, such as an HSK hollow taper shank, and a corresponding coolant supply device. In the present case, the complete tool consists of a basic tool holder 10, a carrier box part 11, and a clamping bracket 13. A clamping jaw 12 is fastened to the carrier box part, and a cutting insert 14 is clamped into the clamping bracket. The clamping bracket has three holes 15, 16, 17 including countersunk holes, through which threaded parts can be inserted with countersunk heads and are used for threaded connection with the carrier box part 11. By a slight misalignment of the holes 15, 16, 17 relative to the threaded holes in the carrier box part, it can be ensured, as known from the principle of the prior art, that the clamping bracket is pulled into the desired end position when operating the clamping threaded parts.

[0029] The other holes 18, 19 (see Figure 6 ) are used to ensure the first positioning of the clamping bracket by means of pins 20, 21 protruding from the carrier box part 11. For this purpose, the holes 18, 19 are selectively larger in diameter than the diameter of the pins 20, 21.

[0030] As can be derived in detail from Figure 1 and Figure 6 , the clamping bracket 13 has a lower clamping jaw 22 and an upper clamping jaw 23, which together with a rear stop 24 form a receiving opening 25 for the cutting insert 14. The clamping surfaces 221, 231 of the clamping jaws are configured arch-shaped or prismatic and are embedded in corresponding gaps of the cutting insert 14 on their upper and lower sides.

[0031] In addition, the upper clamping jaw further has a coolant discharge opening 232 and coolant channels (not shown) that lead from an inlet 233 to the coolant discharge opening 232. Immediately adjacent to the stop 24 or other rounded clearances 26, 27, there is provided a short first slot 28 having a length of 2 mm to 15 mm, preferably a maximum of 5 mm. A widened portion is connected to the slot, and the widened portion extends into a region that extends below the plane formed by the clamping surfaces 231, 221. This region ensures that - while the first slot 28 is configured to be short - the flushed chips can be easily discharged. The length of the widened portion is between 40 mm and 80 mm, and its maximum height is between 10 mm and 25 mm, preferably between 10 mm and 20 mm. Second slots 30 to 33 are respectively connected at the same distance on the upper region of the widened portion at the rear end. These slots have a small width b of 0.1 mm to 3 mm and form an angular range of 180°. The semi-circularly formed slots have a distance a from the upper edge 291 of the widened portion. The second slots 30 to 33 ensure the elasticity of the upper clamping jaw 23 without losing the stability of the clamping bracket. Instead of the semi-circular slots, an open polygonal curve can also be used, which extends at least over an angular size of 120° (or more). In any case, it is important that the slots extend away from the cutting blade and immediately adjacent to the upper region at the rear of the widened portion and, for example, extend in an arc (or polygonal curve shape) such that their ends point in the direction of the widened portion currently configured as the clearance 29. In this case, the plate-shaped clamping bracket can also be configured to be bendable in the longitudinal cross-section for facing grooves radially.

[0032] As can be seen from Figure 2 it follows that the upper clamping jaw 23 has an inclined surface 234, against which the clamping pliers 12 act in the clamped state and thus fix the clamping bracket such that the upper clamping jaw 23 reliably holds the cutting blade 14. The clamping pliers 12, as can be seen from Figure 7 it follows, have a stepped hole 121 for receiving a threaded part (not shown), by means of which the clamping pliers can be fastened to the carrier box-shaped part 11. The clamping pliers are provided at their front end facing the clamping bracket with a protruding clamping lip 122, which acts on the inclined surface 234.

[0033] As can be seen from Figure 3 it follows that the carrier box-shaped part has a substantially planar abutment surface on the side facing the plate-shaped clamping bracket, which is only penetrated by the aforementioned dowels 20, 21 and blind threaded holes 112, 113, 114. The opening 115 is in connection with the inlet 233 (see Figure 6 ) for conveying and further guiding the coolant.

[0034] The box-shaped part furthermore has a cavity 116 which has a threaded hole 117 provided therein for receiving or fastening a clamping jaw or a threaded part for fastening a clamping jaw.

[0035] The visible back side of the load-bearing box-shaped part 11 Figure 5 shows a second profile 118 machined with grooves, the teeth of which extend obliquely. This second profile engages form-locked against the first profile 101 of the basic support 10 (see Figure 8 ). The basic support 10 and the load-bearing box-shaped part 11 also have a central cavity for receiving a feather key 34, which at the same time serves as a stop for the load-bearing box-shaped part during clamping.

[0036] Figure 4 The basic support 10 without the feather key 34 is shown.

[0037] In the assembled tool shown in Figure 1 , first the feather key 34 is inserted into the basic support 10 and then the load-bearing box-shaped part 11 is slipped on, which is fastened to the basic support 10 by a threaded part (not shown). The first profile 101 of the basic support, which is machined with grooves and arranged at 45°, engages here in the second profile 118 of the load-bearing box-shaped part 11 and, based on the selected angular position, serves to better support the vertical and horizontal forces occurring than in known basic supports according to the prior art. After assembling the load-bearing box-shaped part 11, the clamping bracket 13 is slipped on and fastened to the load-bearing box-shaped part 11 by means of a clamping threaded part. Subsequently, if necessary, the upper clamping jaw is lifted with the aid of an opening key and the cutting blade 14, which is designed as a grooving insert, is pushed in until it abuts against the stop 24. Thereafter, the clamping jaw 12 is assembled and tightened by means of a clamping threaded part, thereby ensuring a reliable position fixing of the cutting blade 14 during machining.

[0038] When the cutting blade 14 is worn, the procedure is reversed, i.e. first the clamping jaw 12 is loosened and then, optionally, the cutting blade is released from the fixing with the upper clamping jaw slightly opened and replaced by a new cutting blade. If the clamping bracket is also damaged due to strong stresses during continuous cutting operations, the clamping bracket can be released from the load-bearing box-shaped part and replaced by a new clamping bracket. Usually, replacement of the load-bearing box-shaped part and / or the basic support is not required.

Claims

1. A tool for machining, comprising a basic support (10), a carrier box part (11), a clamping jaw (12) and a clamping support (13), the clamping support having a receiving opening (25) for releasably clamping a cutting insert (14), the receiving opening being defined by a lower clamping jaw (22), an upper clamping jaw (23) opposite the lower clamping jaw, and a rear stop (24), wherein, In the rear region of the receiving opening (25), adjacent to the stop (24) at the rear, a first slot (28) and a gap (29) are provided. By forming the first slot and the gap, the upper clamping jaw (23) can be opened relative to the lower clamping jaw (22). It is characterized in that in the upper region of the gap (29), a plurality of second slots (30, 31, 32, 33) configured as arcs or as open polygonal curves are adjacent. The second slots extend at least at an angle of 120° in a left-bending manner when viewed from the front.

2. The tool for cutting machining according to claim 1, characterized in that, The second slots (30, 31, 32, 33) configured as arcs or as polygonal curves extend at an angle of up to 180°.

3. The tool for cutting machining according to claim 1 or 2, characterized in that, There are 3 to 20 second slots (30, 31, 32, 33) extending parallel to each other and configured as arcs or polygonal curves.

4. The tool for cutting machining according to claim 1, characterized in that, The width (b) of the second slots (30, 31, 32, 33) configured as arcs or polygonal curves is 0.1 mm to 3 mm.

5. The tool for cutting machining according to claim 1, characterized in that, The uppermost arc-shaped second slot in the arc-shaped second slots extends partially above the clamping plane defined by the lower clamping jaw (22) and the upper clamping jaw (23).

6. The tool for cutting machining according to claim 1, characterized in that, The clamping bracket is configured as plate-shaped and has a plurality of through-parts (15, 16, 17) provided with additional gaps for guiding through fastening threaded elements.

7. The tool for cutting machining according to claim 1, characterized in that, A coolant channel for coolant extends in the upper clamping jaw (23), and the coolant is introduced into the front face of the upper clamping jaw.

8. The tool for machining according to claim 1, characterized in that, The clamping bracket (13) is screwed to the carrier box-shaped part (11). The front face of the carrier box-shaped part forms a planar abutment surface for the clamping bracket, and the back face of the carrier box-shaped part has a second profile (118) with grooves machined thereon. The teeth of the second profile are arranged inclined with respect to the longitudinal axis or the transverse axis. Wherein, the basic bracket (10) has a first profile (101) on the side facing the carrier box-shaped part (11), and the first profile is form-locked and fitted into the second profile (118) of the carrier box-shaped part in the assembled state.

9. The tool for cutting machining according to claim 1, characterized in that, The carrier box-shaped part (11) has an intermediate gap on its back face for releasably receiving a sliding key (34), and the sliding key serves as a stop for accurately positioning the carrier box-shaped part (11) with respect to the basic bracket (10).

10. The tool for cutting machining according to claim 1, characterized in that, The clamping bracket (13) is made of high-quality steel.

11. The tool for cutting machining according to claim 1, characterized in that, There are 3 to 5 second slots (30, 31, 32, 33) extending parallel to each other and configured as arcs or polygonal curves.

12. The tool for cutting machining according to claim 1, characterized in that, The clamping bracket is configured as plate-shaped and has three through-parts (15, 16, 17) provided with additional gaps for guiding through fastening threaded elements.

13. The tool for cutting machining according to claim 1, characterized in that, The clamping bracket (13) is threadedly connected to the load-bearing box-shaped part (11). The front side of the load-bearing box-shaped part forms a planar abutment surface for the clamping bracket, and the back side of the load-bearing box-shaped part has a second contour (118) with grooves machined therein. The teeth of the second contour are inclined at an angle of 45° relative to the longitudinal axis or the transverse axis. The basic bracket (10) has a first contour (101) on the side facing the load-bearing box-shaped part (11). In the assembled state, the first contour is form-fittingly engaged in the second contour (118) of the load-bearing box-shaped part.

14. The tool for cutting machining according to claim 1, characterized in that, The clamping bracket (13) is made of 100CR6.

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