Cutting tool with replaceable cutting insert, cutting insert carrier, method for attaching a replaceable cutting insert, method for replacing a cutting insert

Abstract

Cutting insert carrier (4) with a slot (10) formed on the end face for receiving a replaceable cutting insert (6) and a locking element (38) in order to be able to form an elastically releasable positive connection in a fastening position with a locking element (24) formed on the cutting insert (6) in a correspondingly complementary manner, wherein the locking element (38) is provided on a portion (50) which is elastically deflectable for fastening and releasing the cutting insert (6) substantially perpendicular to the cutting direction (SR) of the cutting insert (6), wherein the cutting insert carrier (4) has at least two cheeks (12) defined by the slot (10), each of which has an inner surface (36) which, in the fastening position, comes into contact with a corresponding side surface (14) of the cutting insert (6), characterized in that each cheek (12) has a slot (46) extending substantially in the cutting direction (SR) of the cutting insert (6), which slot divides the cheek (12) into a larger inner cheek portion (48) and a smaller outer cheek portion (50), wherein the locking element (38) is provided on the outer cheek portion (50).

Description

[0001] The present invention relates to a cutting insert carrier according to the preamble of claim 1, a rotationally driven cutting tool with such a cutting insert carrier and a cutting insert, and an assembly method for this cutting tool.

[0002] Cutting tools with replaceable cutting inserts are known from the prior art, in which the cutting insert is inserted and fastened into a slot on the end face of a cutting insert carrier. The cutting insert can be fastened to the cutting insert carrier in various ways. For example, the cutting insert can be fastened directly to the carrier using a screw connection (EP 0 625 395 A1) or clamped between the cheeks using grub screws (DE 42 39 311 A1, DE 197 36 598 A1). However, the use of fastening screws weakens the cutting tool and is only partially suitable, especially for cutting tools with small diameters. A further disadvantage is that the bores and fastening screws running perpendicular to the axis of rotation obstruct the actual course of the cooling channels, and the coolant supply must be ensured by another means, e.g.through coolant channels exiting laterally in front of the cutting tool tip. This not only requires more manufacturing effort but also leads to poorer cooling performance, so that the tool can overheat, especially at the beginning of the machining process.

[0003] However, fastening methods are also known which do not require the screw connection mentioned above. For example, in the drill described in WO 96 / 11079 A1, the cutting insert is clamped in the carrier slot by means of radially elastically preloaded cheeks, either force-fitting or friction-fitting. A similar clamp fit is known from EP 0 984 841 A1, in which the cutting insert is additionally secured in the axial direction by dovetail-shaped circumferential surfaces. However, such clamp fits require a high level of manufacturing precision in order to enable the clamp fit at all and to avoid the risk of it coming loose over time. In order to achieve the radial preload on the cutting insert, the cheeks are elastically expanded outwards, which can lead to problems with the flushness of the outer circumference of the cutting insert and the cutting insert carrier (WO 98 / 10881 A1).

[0004] Furthermore, US 6,506,003 B1 discloses a cutting insert carrier with a slot on the end face for receiving a cutting insert, wherein a press connection is formed between a locking element of the cutting insert carrier and a complementary locking element of the cutting insert. Furthermore, WO 2008 / 072 840 A2 discloses a cutting insert carrier with a receptacle for a cutting insert. A guide rib is formed on the cutting insert carrier, which interacts with a rotational guide element of the cutting insert, and the cutting insert is pressed into the cutting insert carrier with frictional engagement.

[0005] DE 100 42 990 A1 discloses a cutting tool in which the tool head is also secured to the carrier via clamping surfaces and additionally has a releasable snap connection, which additionally provides fixation in the axial direction. A reversible snap connection between the cutting insert and the tool carrier in the circumferential direction is known from EP 1 273 373 A1. This snap connection is achieved either by radially elastic deflection of the carrier's cheeks or by elastic pins provided in the carrier. The provision of elastic pins in the carrier not only increases the manufacturing effort and the associated complexity of the tool, but can also lead to similar problems to those described above with regard to screw connections, particularly with tools with small diameters.On the other hand, if the snap connection is to be made by radial deflection of the cheeks, these cannot be designed to be too rigid in order to be able to realize the snap connection at all, which means that these cheeks cannot withstand larger torques.

[0006] The object of the present invention is therefore to provide a cutting tool with a cutting insert carrier and an interchangeable cutting insert secured against loosening, which allows the cutting insert to be attached and detached in a simple manner and yet withstands high cutting forces.

[0007] This object is achieved with respect to the cutting insert carrier by the features of claim 1 and with respect to the cutting tool by the features of claim 13. A corresponding assembly method is the subject of claims 15 and 17.

[0008] The cutting insert carrier according to the invention has a slot formed on the end face for receiving a replaceable cutting insert as well as a locking element in order to be able to form an elastically releasable positive connection in a fastening position with a locking element formed correspondingly complementarily on the cutting insert. The locking element is provided on a section which can be elastically deflected essentially perpendicular to the cutting direction of the cutting insert for fastening and releasing the cutting insert. Since, according to the invention, only an elastic deflection of a section having the locking element perpendicular to the cutting direction of the cutting insert is required to form or release the elastic positive connection, the connection between the cutting insert and the cutting insert carrier has no effect on the design of both parts with regard to the cutting forces and moments that occur.The cutting insert carrier, in particular the strength of the cheek, can be designed to withstand the cutting forces and moments that occur. In other words, by shifting the deflection of the locking element in a direction perpendicular to the cutting direction, the design of the elastic form fit can be separated from the strength requirements of the cutting process, so that the provision of an elastic snap connection between the cutting insert carrier and the cutting insert does not lead to any weakening of the tool.

[0009] Advantageous further developments of the cutting insert carrier are the subject of the subclaims.

[0010] The cutting insert carrier according to the invention has at least two cheeks defined by the slot, each of which has an inner surface which, in the fastening position, comes into contact with a corresponding side surface of the cutting insert.

[0011] The locking element can be designed in the form of a projection with an undercut step on this inner surface. The positive connection between the cutting insert carrier and the cutting insert is advantageously achieved by means of an undercut step in a correspondingly designed locking element that engages the cutting insert. The cutting insert is thus fixed in the circumferential direction because in one direction the cutting insert rests with a side surface on the inner surface of the cheek and in the other direction is held by the positive connection of the locking elements. Preferably, the side surface of the cutting insert opposite the cutting edge and chip surface rests flat against the cheek so that the positive connection only prevents twisting of the cutting insert in the direction of rotation, i.e. against the cutting forces.

[0012] Advantageously, the slot formed in the cutting insert carrier has a base surface for axial support of the cutting insert. Additionally, the step is angled relative to the rotational axis of the cutting insert carrier and extends inward in the feed direction of the tool carrier. This ensures that the projection with the undercut step secures the cutting insert against loosening not only in the circumferential direction but also in the axial direction, without requiring any additional design measures, which would in turn entail increased manufacturing costs.

[0013] It has been found to be advantageous if the angle enclosing the step and the axis of rotation lies in a range of 5 to 30°, preferably 15 to 25°, in order to achieve the above-mentioned axial securing on the one hand and to have a sufficient lever to elastically deflect the projection perpendicular to the cutting direction or perpendicular to the inner surface of the cheek on the other hand.

[0014] The slot formed on the front side in the cutting insert carrier can be manufactured particularly easily if the inner surface of the cheeks, including the projection surface, runs parallel to the axis of rotation.

[0015] If at least the outer edge of the step is rounded and the locking element formed on the cutting insert also has a rounded edge, it is possible that when the two edges meet, the projection on the carrier side automatically gives way due to the elasticity of the corresponding section, without having to deflect this section of the cutting insert carrier with other means.

[0016] Each cheek has a slot running essentially in the cutting direction of the cutting insert, which divides the cheek into a smaller outer cheek section and a larger inner cheek section, with the locking element provided on the outer cheek section. This clever design measure makes it possible to divide the cheek into two sections, the inner of which serves exclusively to absorb the cutting forces and moments, and the outer of which can be designed essentially for locking the cutting insert. Because the slot runs in the cutting direction, the weakening of the cheek is also reduced to a minimum. If the outer cheek section is separated from the inner cheek section, the latter can also be deflected elastically perpendicular to the cutting direction much more easily, so that the force required to fasten and release the form fit can be kept within limits.Since the inner cheek section does not have to be deflected to fasten and loosen the cutting insert, it can be kept so rigid that it can withstand even very high cutting forces and moments.

[0017] The slot should be at least as deep as the axial extension of the projection in order to ensure that the entire locking element can be deflected.

[0018] The inner cheek section can preferably be provided with a coolant channel with a front-side outlet opening in order to guide the coolant to the tool tip and to ensure sufficient cooling of the cutting edges.

[0019] If the inner cheek section is not large enough to accommodate a coolant channel, e.g. because this would lead to a disproportionate weakening of the cheek in the case of cutting insert holders with small diameters, the inner cheek section can only have a coolant groove on its inside, which, in conjunction with the cutting insert resting on the inner surface, forms a cooling channel.

[0020] Furthermore, the base surface can have a cooling channel outlet opening and a recess for establishing a coolant connection between this cooling channel opening and a coolant groove in the inner cheek section. If the cutting insert carrier does not have spiral coolant channels, but only a central coolant channel, this recess ensures the distribution of the coolant to the respective cutting edges when the cutting insert sealingly covers it in the mounting position.

[0021] To ensure that the cutting insert inserted into the slot can be moved from the locking position to the unlocking position or vice versa by rotating about the axis of rotation, the inner cheek section should have a recessed or flattened section on its inner surface.

[0022] Advantageously, the cheek not only serves to secure the cutting insert, but can also form part of the cutting edge geometry. The front face can serve as the tool's clearance surface and be designed to be flush with the cutting insert, both radially and circumferentially.

[0023] The object underlying the invention is achieved with regard to the cutting insert by the features of claim 14. According to the invention, the locking element, which serves to form the elastically releasable positive connection with a correspondingly complementary locking element on the cutting insert carrier, is designed on the side surface in the form of a recess with an undercut step. By providing an undercut on the side surface, which comes into contact with the cutting insert carrier in the fastened state, it is ensured that the cutting insert is fixed in the circumferential direction, namely in one direction via the flat contact of the side surface with a corresponding inner cheek surface of the cutting insert carrier and in the other direction via the positive connection of the undercut step with a correspondingly complementary locking element on the carrier.

[0024] If the step is angled relative to the cutting insert's rotational axis and this extends inward in the feed direction of the cutting insert, the cutting insert is axially secured in the inserted state, both by its base surface and by the projection with the angled step. Thus, the projection with the undercut step provides fixation not only in the circumferential direction but also in the axial direction. The step and rotational axis can form an angle in the range of 5 to 30°, preferably 15 to 25°.

[0025] Since, as described above, the positional fixation can be achieved exclusively through the interaction of the insert-side locking element with the carrier-side locking element, the side surfaces of the cutting insert, including the recess surface, can run parallel to the rotation axis, which can greatly simplify the overall production of the cutting insert. To facilitate the elastically releasable positive locking with the complementary locking element on the cutting insert carrier, it is advantageous if at least the outer edge of the recess is rounded, so that the edges that meet during the fastening process can smoothly avoid each other.

[0026] The cutting insert can be rotationally symmetrical with respect to the rotation axis. In a cutting insert with two cutting edges, the cutting insert can be a plate-shaped drill bit with plane-parallel side surfaces, with the cutting edges offset by 180° with respect to the rotation axis.

[0027] The cutting insert is preferably made of hard metal and has at least a partial coating. Depending on the application, this coating may contain, for example, titanium nitride or titanium aluminum nitride.

[0028] If the cutting insert has an end face which, in the fastening position, is radially and circumferentially flush with a corresponding end face of the cutting insert carrier, the interaction between the cutting insert carrier and the cutting insert can be further improved.

[0029] With regard to a cutting tool assembly comprising a cutting insert carrier and an interchangeable cutting insert secured against loosening, the object underlying the invention is achieved by the features of claim 24. According to the invention, for fastening and releasing the cutting insert, a section comprising the locking element on the cutting insert carrier is elastically deflected substantially perpendicular to the cutting direction of the cutting insert. Since the interaction of the cutting insert carrier and the cutting insert is designed such that the carrier-side locking element is only deflected perpendicular to the cutting direction, the cutting tool can be designed in the cutting direction so that it can absorb high torques.Furthermore, this positive connection enables the cutting insert to be fastened in the cutting insert carrier, which is practical even for cutting tools with small diameters and allows unhindered coolant supply to the tool tip.

[0030] The subject matter of claims 25 and 26 is a method for fastening an interchangeable cutting insert in a cutting insert carrier and a method for exchanging such a cutting insert, respectively. Short description of the characters

[0031] They show: Fig. 1 a cutting tool with a cutting insert carrier and a cutting insert to be inserted therein according to a first embodiment of the invention; Fig. 2 the cutting tool with inserted cutting insert according to the first embodiment of the invention; Fig. 3 is a side view of the cutting insert according to the first embodiment of the invention; Fig. 4 a side view of the Fig. 3 shown cutting insert; Fig. 5A a plan view of the Fig. 3 shown cutting insert; Fig. 5B is a sectional view along the line BB in Fig. 3; Fig. 6 a sectional view along the line AA in Fig. 3; Fig. 7 is a cross-sectional view of the upper portion of a cutting insert carrier according to the first embodiment of the invention; Fig. 8 a plan view of the Fig. 7 shown cutting insert carrier; Fig. 9 a side view of the cutting insert carrier with inserted cutting insert; Fig. 10 a plan view of the Fig. 9 shown cutting insert carrier with inserted cutting insert; Fig. 11 is a plan view of a cutting insert carrier with inserted cutting insert according to a second embodiment of the invention; and Fig. 12 is a perspective view of the cutting tool according to the second embodiment. Detailed description of preferred embodiments

[0032] In the Fig. 1 and Fig. 2 shows a cutting tool 2 according to the invention with a cutting insert carrier 4 and a cutting insert 6 to be fastened therein. The cutting insert 6 is an interchangeable plate with two cutting edges 8 offset by 180° to the axis of rotation. To fasten the cutting insert 6 in the cutting insert carrier 4, the cutting insert 6 is inserted axially into a slot 10 formed on the front side of the cutting insert carrier 4 and then counter to the direction of rotation (ie clockwise in Fig. 1) is rotated until the cutting insert 6 comes into contact with the inside of the cheek 12 defined by the slot 10. Furthermore, Fig. 1 shows that a feed tube 13 is connected between the cutting insert 6 and the cutting insert carrier. Fig. 2 shows the cutting tool 2 according to the invention with the cutting insert 6 fastened in the cutting insert carrier 4 and the feed tube 13 received therebetween. How the cutting insert is fastened in detail to the cutting insert carrier 4 and the feed tube 13 is received therebetween will be described in detail below.

[0033] In the following, with reference to the Fig. 3 to 6, the cutting insert according to the invention is described in detail. The cutting insert is a plate-shaped body 6, rotationally symmetrical with respect to the rotation axis A, each having plane-parallel side surfaces 14 and outer surfaces 16. The cutting insert further comprises a base surface 18 extending perpendicular to the rotation axis A and serving for axial support in the slot 10 of the cutting insert carrier 4, and two flank surfaces 20 opposite the base surface 18, which enclose a tip angle σ of approximately 150° and define a transverse cutting edge 22. The side surfaces 14 have, on the side opposite the respective cutting edge 8, a recess 24 with a surface 26 plane-parallel to the side surface 14. The surfaces 14 and 26 are separated by an undercut step 28 ( Fig. 6). The straight step 28 is set at an angle α of approximately 20° with respect to the rotational axis and extends inwards in the feed direction of the cutting insert 6. The recess 24 is located on the radially outer section of the cutting insert 4 defined by the step 28. As already mentioned above, the step 28 has an undercut in order to form a positive connection with a complementarily formed step on the cutting insert carrier 4. The step 28 has an outer edge 30 and an inner edge 32, which, as can be seen from Fig. 6 are rounded.

[0034] A bore 70 extending from the base surface 18 and coaxial with the rotational axis A extends to a branch channel bore 72 running essentially perpendicular to the rotational axis A, which opens into the side surfaces 14 on both sides of the cutting insert 6. The branch channel bore 72 does not run along a transverse axis B, but is set at an angle □ of approximately 20° to it, as can be seen from Fig. 5B can be seen.

[0035] In order to avoid radial play between the axial bore 70 and the feed tube 13 to be inserted therein, the diameters of both components are correspondingly closely tolerated.

[0036] Furthermore, the diameter d a the axial bore 70 is approximately the wall thickness w of the feed tube 13 to be used larger than the diameter d rthe branch channel bore 72, so that the flow cross-section of the coolant remains the same at the transition from the feed tube 13 to the branch channel bore 72.

[0037] The cutting insert is made of solid carbide and, depending on the application, has a corresponding coating, e.g., titanium nitride or aluminum titanium nitride or similar.

[0038] In the following, the cutting insert carrier 4 according to the invention is described in detail with reference to the Fig. 7 and Fig. 8. The cutting insert carrier 4 has a slot 10 on its front side, as best seen from Fig. 1, which runs transversely to the rotational axis A. The cutting insert carrier 4 further comprises two cheeks 12, which, in addition to the slot 10, are defined by spiral-shaped chip grooves 34 and the outer diameter of the cutting insert carrier 4. Each cheek 12 has an inner surface 36 running parallel to the rotational axis A and a projection 38 plane-parallel to this inner surface 36. The step 40 running between the projection 38 and the inner surface 36 is set at the same angle α with respect to the rotational axis A as the previously described step 28 of the cutting insert 6.

[0039] Furthermore, the carrier-side step 40 also has an undercut and rounded edges 42 and 44. Each cheek 12 has a continuous slot 46 running perpendicular to the inner surface 36, which runs parallel to the axis of rotation and has a slot depth T that is at least the length L of the axial extension of the projection 38. The slot 46 divides each cheek into an inner cheek section 48 and an outer cheek section 50, with the projection 38 being formed on the outer cheek section 50. The end faces 52 of the cheek 12 form the flanks of the cutting tool 2 according to the invention.

[0040] The slot 10 has a base surface 54 extending perpendicular to the rotational axis, which serves to axially support the cutting insert 6 in the cutting insert carrier 4. Furthermore, the cutting insert carrier 4 has a central coolant channel 56 with an enlarged end section 57, into which the feed tube 13 can be precisely inserted.

[0041] To avoid radial play between the end section 57 and the feed tube 13 to be inserted therein, the diameters of both components are correspondingly closely tolerated.

[0042] The diameter d e of the end section is approximately the wall thickness w of the feed tube 13 to be used larger than the diameter d k of the coolant channel 56, so that the flow cross-section of the coolant remains the same at the transition from the coolant channel 56 to the feed tube 13 and their inner surfaces lie flush against one another.

[0043] Semi-circular coolant grooves 60 are provided in the cheeks 12, via which the coolant, which is guided radially outwards via the cutting insert 6, ie via the bores 70 and 72, is guided in the direction of the tip of the cutting tool 2 (see Fig. 7).

[0044] Cutting insert carrier 4 and cutting insert 6 are adapted to each other so that the branch channel bore 72 of the cutting insert 6 also opens into the coolant grooves 60 of the cutting insert carrier 4. Ideally, the diameter of the openings corresponds to the width of the coolant grooves 60.

[0045] In the Fig. 9 and Fig. 10 shows the upper section of the cutting insert carrier 4 with the inserted cutting insert 6. As can be seen from Fig. 10, the side surfaces 14 of the cutting insert 6 come into flat contact with the corresponding inner surfaces 36 of the cheeks 12. The side surfaces 14 cover the coolant grooves 60 of the cutting insert carrier 4, so that closed coolant channels are created.

[0046] Furthermore, the projections 38 engage with the undercut steps 40 in the corresponding recesses 24 and steps 28 formed in the cutting insert 6, thereby forming a positive connection. How this positive connection is achieved is illustrated with reference to a second embodiment, which is shown in the Fig. 11 and Fig. 12 is shown.

[0047] The fastening principle of the second embodiment of the cutting tool according to the invention is identical to that of the first embodiment. The differences between the second embodiment and the first embodiment lie solely in the design of the cutting edge geometry, which will be discussed in detail below.

[0048] Fig. 11 shows a plan view of the front side of a cutting tool 2 according to the invention with a cutting insert carrier 4 and a cutting insert 6. To attach the cutting insert 6 to the cutting insert carrier 4, proceed as follows:

[0049] First, the feed tube 13 is inserted into the end section 57 of the coolant channel 56 of the cutting insert carrier 4. The feed tube 13 is of such a length that it protrudes approximately halfway from the base area 58 of the slot 10. Subsequently, the cutting insert 6 is inserted axially into the slot 10 provided for this purpose in the cutting insert carrier 4. Fig. 11 shows the state in which the cutting insert 6 is already inserted, but not yet positively connected to the cutting insert carrier 4. To form this positive connection, the cutting insert 6 must be Fig. 11, indicated by arrows, are rotated against the direction of rotation of the cutting insert carrier 4. In doing so, the rounded outer edges 30 and 42 of the cutting insert 6 and the cutting insert carrier 4 meet. Since the projections 38 are each formed on the outer cheek section 50, and this cheek section is separated from the inner cheek section 48 by the slot 46, the outer cheek section 50 deviates briefly perpendicular to the course of the slot, as indicated by the arrows and the dashed line, in order to then return to its original position once the outer edges 30 and 42 have slid past one another and the side surfaces 14 of the cutting insert 6 come into contact with the inner surfaces 36 of the cutting insert carrier 4, and to form an elastically releasable positive connection via the mutual engagement of the undercut steps 28 and 40.

[0050] In this process, the feed tube 13 plays a crucial role, as it fixes the central position of the cutting insert 6 and prevents the cutting insert 6 from deflecting in a radial direction when twisting against the preload of the outer cheek sections 50.

[0051] Since the slot 46 runs perpendicular to the inner surface 36 of the cheek 12 and thus perpendicular to the side surface 14 of the cutting insert 6, and the cutting direction SR of the cutting insert 6 runs approximately perpendicular to the side surface 14, the outer cheek section 50 with the projection 38 formed thereon is elastically deflected essentially perpendicular to the cutting direction SR of the cutting insert 6. Therefore, the outer cheek section 50 can be designed such that it is rigid in the cutting direction SR, but allows the elastic deflection necessary for the positive connection in a direction perpendicular thereto. Since in the fastening position both outer cheek sections 50 want to return to their original position and move in opposite directions, this creates an elastic positive connection. However, due to friction and differences in the radial restoring forces, radial deviations could occur.However, since the cutting insert 6 is coupled to the cutting insert carrier 4 via the feed tube 13, the feed tube 13 counteracts any radial forces occurring on the cutting insert 6 and centers the cutting insert 6 with respect to the cutting insert carrier 4.

[0052] To replace the cutting insert 6 with a new one, proceed in the reverse order. The cutting insert 6 is rotated against the elastic resistance of the outer cheek sections 50 relative to the cutting insert carrier 4 in the direction of rotation (counterclockwise in Fig. 11) is rotated so that the outer cheek sections 50 briefly deflect outwards and then release the cutting insert 6. Here, too, the feed tube 13 prevents radial deflection of the cutting insert 6. The cutting insert 6 can then be axially removed from the slot 10 in the cutting insert carrier 4 and a new cutting insert 6 can be inserted and locked as described above.

[0053] In order to be able to pivot the cutting insert 6 for fastening or releasing in the slot 10, the cheeks 12 must have a recessed or flattened section 62.

[0054] The differences between the two versions are discussed in more detail below. Fig. 11, the cutting insert 6 does not have straight cutting edges 8 as in the first embodiment, but curved cutting edges 8. Furthermore, the cutting insert 6 has a chip surface 64 which merges flush into the chip groove 34 of the cutting insert carrier 4, as in Fig. 12 is clearly visible.

[0055] The cutting tool according to the invention has been described with reference to a drilling tool with an interchangeable insert having two cutting edges. However, the inventive fastening of an interchangeable cutting insert in a cutting insert holder is not limited to the described embodiments. Thus, cutting inserts with three or more cutting edges can be used in cutting insert holders with three or more cheeks according to the invention. Naturally, the cutting insert can have any desired point angle and / or point grind. Furthermore, the material of the cutting insert can be adapted to the respective application. Furthermore, it is at the discretion of the person skilled in the art to change the aforementioned angle specifications within a certain range.The angle of attack α of the undercut steps should be selected in such a way that the step simultaneously ensures axial securing of the cutting insert and, on the other hand, still allows sufficient leverage for radially elastic deflection of the outer cheek section.

[0056] Furthermore, the axial coolant grooves can be provided not only on the cutting insert carrier, but additionally or instead on the side surfaces of the cutting insert, which in cooperation with the cheeks of the cutting insert carrier form closed coolant channels to guide the coolant to the tool tip. For the sake of completeness, it should be mentioned that the cutting tool according to the invention is suitable for minimum quantity lubrication (MQL) use.

Claims

[1] Cutting insert carrier (4) with a slot (10) formed on the end face for receiving an exchangeable cutting insert (6) and a locking element (38) in order to be able to form an elastically releasable positive connection in a fastening position with a locking element (24) formed on the cutting insert (6) in a correspondingly complementary manner, wherein the locking element (38) is provided on a portion (50) which is elastically deflectable for fastening and releasing the cutting insert (6) substantially perpendicular to the cutting direction (SR) of the cutting insert (6), wherein the cutting insert carrier (4) has at least two cheeks (12) defined by the slot (10), each of which has an inner surface (36) which, in the fastening position, comes into contact with a corresponding side surface (14) of the cutting insert (6), characterized bythat each cheek (12) has a slot (46) running substantially in the cutting direction (SR) of the cutting insert (6), which slot divides the cheek (12) into a larger inner cheek portion (48) and a smaller outer cheek portion (50), wherein the locking element (38) is provided on the outer cheek portion (50). [2] Cutting insert carrier (4) according to claim 1, characterized by that the locking element (38) on the inner surface (36) is formed in the form of a projection (38) with an undercut step (40). [3] Cutting insert carrier (4) according to claim 2, characterized by , that the slot (10) has a base surface (54) for axially supporting the cutting insert (6), and the step (40) is set relative to the axis of rotation (A) of the cutting insert carrier (4) and extends inwards in the feed direction of the cutting insert carrier (6). [4] Cutting insert carrier (4) according to claim 2 or 3, characterized by that the inner surface (36) runs parallel to the axis of rotation (A) and the projection (38) has a contact surface that is plane-parallel to the inner surface (36). [5] Cutting insert carrier (4) according to claim 4, characterized by that the step (40) and the axis of rotation (A) enclose an angle (α) in a range of 5° to 30°. [6] Cutting insert carrier (4) according to one of claims 2 to 5, characterized by that the step (40) has at least one rounded outer edge (42). [7] Cutting insert carrier (4) according to one of claims 1 to 6, characterized by that the slot (46) has at least the axial extension (L) of the locking element. [8] Cutting insert carrier (4) according to one of claims 1 to 7, characterized bythat the inner cheek section (48) has a coolant groove (60) formed on its inner surface (36), running substantially axially and opening at the end face of the cutting insert carrier (4) in order to guide coolant guided over the inserted cutting insert (6) and radially emerging therefrom to the end face. [9] Cutting insert carrier (4) according to one of claims 1 to 8, further characterized by a coolant channel (56) exiting centrally in the slot, wherein the coolant channel (56) has an end section (57) for the precise reception of a feed tube (13) centering the cutting insert (6) and supplying it with coolant. [10] Cutting insert carrier (4) according to claim 9, characterized bythat the end section (57) is a cylindrical recess enlarged by the wall thickness of the feed tube (13) to be inserted, so that in the inserted state of the feed tube (13) its inner surface adjoins the upstream section of the coolant channel (56) flush. [11] Cutting insert carrier (4) according to one of claims 1 to 10, characterized by that the inner cheek portion (48) has a recessed or flattened portion (62) on its inner surface (36) to allow pivoting of the cutting insert (6) inserted into the slot (10) about the rotation axis (A) from the locking to the unlocking position and vice versa. [12] Cutting insert carrier (4) according to one of claims 1 to 11, characterized by that the end face (52) of the cheeks (12) serves as a free surface and is designed such that it is flush radially and circumferentially with the cutting insert (6) to be used. [13] Rotary driven cutting tool (2) with a cutting insert carrier (4) according to one of claims 1 to 12; and a replaceable cutting insert (6) secured against loosening, which is received in a slot (10) formed on the end face of the cutting insert carrier (4), wherein the cutting insert (6) and the cutting insert carrier (4) have complementary locking elements (24, 38) which form an elastically releasable positive connection in the fastening position, characterized by , that for fastening and releasing the cutting insert (6), a section (50) having the locking element (38) on the cutting insert carrier (4) can be deflected radially elastically substantially perpendicular to the cutting direction (SR) of the cutting insert (6). [14] A rotary driven cutting tool (2) according to claim 13, further characterized byan intermediate feed tube (13) which is partially received in an end section (57) of the coolant channel (56) of the cutting insert carrier (4) and partially in the axial bore (70) provided in the cutting insert (6) in order to center the cutting insert (6) with respect to the cutting insert carrier (4) and to transfer coolant guided centrally in the cutting insert carrier (4) to the cutting insert (6). [15] Method for fastening an exchangeable cutting insert (6) in a cutting insert carrier (4) according to one of claims 1 to 12, characterized by the steps: axial insertion of the cutting insert (6) into a slot (10) formed on the end face in the cutting insert carrier (4); and Rotating the cutting insert (6) against the direction of rotation of the cutting insert carrier (4) and against the resistance of a locking element (38) provided on an elastically deflectable section (50) of the cutting insert carrier (4), so that the locking element briefly deflects perpendicular to the cutting direction (SR) of the cutting insert (6) and then forms a positive connection with the cutting insert (6). [16] Method according to claim 15, characterized by that before inserting the cutting insert, a feed tube (13) is inserted with a precise fit into an end section (57) of a central coolant channel (56), so that after subsequent axial insertion of the cutting insert (6), a projecting section of the feed tube (13) is received with a precise fit in an axial bore (70) of the cutting insert (6). [17] Method for replacing a cutting insert (6) in a cutting insert carrier (4) according to one of claims 1 to 12, characterized by the steps: Rotating the cutting insert (6) to be replaced in the direction of rotation of the cutting insert carrier (4) and against the resistance of a locking element (38) provided on an elastically deflectable section (50) of the cutting insert carrier (4), so that the locking element deflects perpendicularly to the cutting direction (SR) of the cutting insert (6) and subsequently releases the cutting insert (6); axial removal of the cutting insert (6) from a slot (10) formed on the end face in the cutting insert carrier (4); axial insertion of the cutting insert (6) into the front-face slot (10) in the cutting insert carrier (4); and Rotating the cutting insert (6) against the direction of rotation of the cutting insert carrier (4) and against the resistance of an elastically deflectable section (50) of the cutting insert carrier (4), so that it briefly deviates perpendicular to the cutting direction (SR) of the cutting insert (6) and then forms a positive connection with the cutting insert (6).

Images