Cutting tool

Abstract

The present invention provides a cutting tool, particularly a saw blade, having a carrier (1) and a cutting insert (3), wherein the carrier (1) forms at least one cylindrical accommodating portion (2) and at least one stop jaw (8) for the cutting insert (3), the cutting insert (3) has a cylindrical cutting base (4) and a cutting edge (5) protruding radially from the cutting base, the cutting edge having at least one stop (6) for the stop jaw (8) on the back side of the cutting edge, the cutting insert (3) being insertable into the accommodating portion (2) transverse to the cutting direction and rotatable between an insertion position and a cutting position in the inserted state, and the cutting insert (3) being fixed in the cutting position by an anti-rotation device. In order to provide a tool of the type mentioned at the outset which, despite simple manufacturing and mounting requirements, ensures sufficient stability and strength of the replaceable cutting insert in the carrier, thereby enabling reliable application to thin slices, particularly when the carrier thickness is less than 6 mm, it is proposed that the cutting insert (3) is inserted into the cylindrical receiving part (2) in a bayonet-locking manner.

Description

Technical Field

[0001] The present invention has a carrier and a cutting insert, and the carrier has for a cutting insert at least one cylindrical receiving portion and constituting at least one stopper jaw, the cutting insert having a cylindrical cutting substrate and a cutting edge protruding radially from the cutting substrate, the cutting edge having on the back side of the cutting edge at least one stopper for the stopper jaw, the cutting insert being insertable laterally into the receiving portion with respect to the cutting direction and being rotatable between an insertion position and a cutting position in the inserted state, and the cutting insert being fixed at the cutting position by a rotation prevention device, relates to a cutting tool, in particular a saw blade.

Background Art

[0002] From US Patent Application Publication No. 20020112590, a circular saw blade having replaceable cutting inserts is known. For this, the circular saw blade forms a carrier having a plurality of cylindrical receiving portions and stopper jaws, whereby each cutting insert is laterally with respect to the cutting direction, in particular axially parallel to the carrier accommodation can be inserted into the portion. When inserted into the cylindrical receiving portion, the cutting insert is rotated from the insertion position to the cutting position about a pivot axis parallel to the carrier axis. At the cutting position, a centering spring arranged to extend substantially radially in the stopper jaw engages a centering groove corresponding to the centering spring of the inserted cutting insert. For anti-rotation, a lock screw for fixing the cutting insert in the receiving portion is provided. However, its drawback is that it is not possible to easily achieve a saw blade thickness of less than 6 mm based on the limitation regarding the minimum screw diameter set from a structural point of view. In addition, when the thickness of the saw blade is small, there is a problem that the stability and strength of the cutting insert on the carrier become very low during operation. For these reasons, such a cutting insert system has not been satisfactorily used for thin cutting applications so far.

Prior Art Documents

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, despite simple manufacturing and mounting conditions, it is necessary to ensure sufficient stability and strength of the replaceable cutting insert in the carrier, thereby enabling reliable application to thin cutting, especially when the carrier thickness is less than 6 mm, for a cutting tool of the type described at the beginning.

Means for Solving the Problems

[0005] The present invention solves the problems raised by the fact that the cutting insert is inserted into a cylindrical receiving part in a bayonet lock manner.

[0006] Insertion of a cutting insert into a bayonet lock type cylindrical receiving portion means that the cutting insert and the cylindrical receiving portion are pushed into the insertion position in the direction of the cylinder axis and rotated to the cutting position in the direction opposite to the cylinder axis in order to generate a connection between the cutting insert and the cylindrical receiving portion. Here, preferably, the cylinder axes of both the receiving portion and the cutting substrate substantially coincide. This not only enables easy attachment or removal of the cutting insert, which can be carried out by hand especially when the cutting tool is already assembled, but also each cutting insert is fixed in the cylindrical receiving portion with sufficient stability at the cutting position. As a result, it is possible to make the corresponding anti-rotation devices, such as bolts or spring steel elements, smaller in size, and in particular, to omit the screw as an anti-rotation device. However, of course, attachment or removal of the cutting insert, which can be automatically carried out by a corresponding mounting machine, is basically possible. In addition, based on the measures according to the present invention, during operation, uniform cutting force is transmitted from the cylindrical receiving portion to the carrier via at least one stop jaw, and for example, the risk of detachment of the cutting insert from the receiving portion caused by the action of a force extending laterally with respect to the cutting direction due to an impact or a blow can be reduced. Overall, the features according to the present invention can reduce the breakage of the cutting insert, thereby achieving the prerequisite for providing a cutting tool for thin cutting applications, especially a saw blade. Therefore, the tool can be easily, preferably automatically, equipped with replaceable cutting inserts despite a carrier thickness of less than 6 mm. Since the cutting insert is inserted into the cylindrical receiving portion in a bayonet lock type, a fitting type fixing of the cutting insert into the cylindrical receiving portion transverse to the cutting direction is carried out. Corresponding locking means of the bayonet lock can be provided over the peripheral region of the cylindrical receiving portion, and these locking means provide the necessary holding of the cutting insert in the receiving portion over a suitable surface. The cutting edge is provided with at least one stop for the stop jaw on the back side of the cutting edge. The back side of the cutting edge particularly means that the stop is provided on the back side of the cutting edge facing the rake face from which the cut chips flow out.For the sake of clarity, it should be noted that in this case, the blade of the cutting insert is called a cutting edge for simplicity.

[0007] Particularly advantageous structural conditions are obtained when at least one nose that can be inserted into an undercut groove of the receiving part is provided around the cylinder of the cutting insert. In this case, the undercut groove has a first insertion guide groove extending parallel to the cylinder axis of the cylindrical receiving part based on a bayonet lock, and a second rotation guide groove is connected to the first insertion guide groove substantially transversely to the first insertion guide groove in the circumferential direction of the cylinder of the receiving part. Therefore, when inserting the cutting insert into the receiving part, first, the nose of the cutting insert can move along the insertion guide groove, so that the cutting insert occupies an insertion position in the receiving part. When the cutting insert and the receiving part are rotated in opposite directions with respect to the cylinder axis, the nose can slide along the rotation guide groove, so that the cutting insert finally occupies a cutting position with respect to the receiving part. The nose can be formed, for example, as a kind of cam whose surfaces are inclined with respect to each other and with respect to the circumference of the cutting insert. Therefore, the cross-section of the insertion guide groove can substantially coincide with the longitudinal cross-section of the nose, while the cross-section of the rotation guide groove can substantially coincide with the cross-section of the nose, and the nose can move along the groove with play.

[0008] Conversely, it is also conceivable that, similar to the above characteristics, at least one nose that can be inserted into an undercut groove of the cutting insert is provided around the inner circumference of the receiving part. For the sake of clarity, it should be noted that the inner circumference of the receiving part around the cylinder means the surface of the receiving part facing the circumference of the cutting insert.

[0009] To enable both simple mounting conditions and uniform support of the cutting insert during operation, the cutting edge of the cutting insert projects radially from the cylindrical cutting substrate of the cutting insert inserted into the cylindrical receiving portion, and the cutting edge has, on the back side of the cutting edge, two stopper surfaces that are preferably inclined to each other at an obtuse angle for centering the cutting insert at the stopper jaws. In this case, the two surfaces arranged inclined to each other are preferably also inclined with respect to both cylindrical base surfaces of the cutting substrate. Due to these features, reliable centering of the cutting insert in the receiving portion can be achieved despite simple manufacturing and mounting conditions, thereby enabling uniform stress loading on all cutting inserts of the tool according to the invention.

[0010] To further reduce breakage of the cutting insert, it is recommended that the cutting insert be provided with two stoppers distributed over its circumference for centering the cutting insert at the two stopper jaws, and these stoppers face each other with respect to the cylinder axis of the cylindrical cutting substrate. This enables a compact seating of the cutting insert in the receiving portion, so that particularly advantageous introduction of cutting forces or particularly uniform transmission of cutting forces to the carrier can be achieved. In this case, of course, at least one of the stoppers or the corresponding stopper jaws can be provided with stopper surfaces arranged in a mutually engaging manner as described above.

[0011] Preferably, the carrier is provided with a cavity for an anti-rotation device that connects around the inside of the receiving portion and faces the stopper jaws. Thereby, not only are simple manufacturing conditions obtained despite the tool being strong enough for light cutting applications, but the corresponding anti-rotation device can be easily inserted into or exchanged in the cavity based on easy access to the cavity. Preferably, the insertion direction of the anti-rotation device into the cavity also extends parallel to the cylinder axis or the carrier rotation axis.

[0012] In this context, it is particularly advantageous if the anti-rotation device is constituted by a tension spring which is supported on two sides of the cavity on the one hand and abuts against the cylindrical cutting substrate on the other hand. For reliable tensioning conditions during operation, the corresponding support and abutment directions preferably extend at right angles to each other.

[0013] Additional stability when simple mounting conditions are simultaneously obtained is achieved when a locking catch for preventing rotation at the cutting position is arranged around the cylinder of the cutting insert. Thereby, the tensioning of the tension spring for preventing rotation can be simply carried out only by the rotational movement of the cutting insert and the cutting position of the receiving part.

[0014] Furthermore, in order to fix the tension spring itself so that it cannot be disengaged from the cavity during operation, in particular based on external impacts or shock actions, it is proposed that the tension spring is inserted into a guide receptacle on the side of the cavity. Particularly preferably, the guide receptacle constitutes a stopper in the insertion direction of the tension spring or in the opposite direction of the insertion direction for the part of the tension spring inserted into the guide receptacle.

[0015] The invention also relates to a cutting insert for a cutting tool having a cylindrical cutting substrate and a cutting edge protruding radially from this cutting substrate, this cutting edge being provided on the back side of the cutting edge with at least one stopper for a stop jaw. At least one nose and / or at least one groove is arranged around the cylinder of the cutting insert, and this at least one nose and / or at least one groove is formed such that the cutting insert can be inserted into a tool, in particular a receiving part of a circular saw blade, in a bayonet lock manner. Further embodiments are described in the claims.

[0016] Despite simple manufacturing conditions, on the one hand, particularly advantageous mounting conditions are provided, and on the other hand, to enable stable seating of the cutting insert within the tool receptacle, it is proposed that the lock catch constitutes a semi-kidney-shaped catch guide groove having a lower receiving arc and a higher tensioning arc that extend over the peripheral portion of the cutting substrate. The lower receiving arc of the catch guide groove enables problem-free insertion of the cutting insert into the tool receptacle, and in case the anti-rotation portion, for example the abutting portion of the tensioning spring, engages with the receiving arc with play or non-contact. When the cutting insert or the carrier is rotated to the cutting position, the anti-rotation portion slides along the semi-kidney-shaped catch guide groove until it abuts against the higher tensioning arc, where it is held in a friction-engaging manner and thus fixed.

[0017] The subject matter of the invention is illustrated by way of example in the drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0019] The cutting tool according to the present invention is formed as a circular saw blade, and the carrier 1 of this circular saw blade is provided with a plurality of cylindrical receiving portions 2 arranged on the peripheral side. In these receiving portions, cutting inserts 3 according to the present invention are respectively inserted. Each cutting insert 3 includes one cylindrical cutting substrate 4 and one cutting edge 5 protruding radially from this cutting substrate. Further, the cutting insert 3 is provided with two stoppers 6, 7 distributed over its circumference for centering the cutting insert 3 at two stopper joints 8, 9, and these stoppers 6, 7 face each other with respect to the cylinder axis of the cylindrical cutting substrate 4.

[0020] The cutting insert 3 can be inserted transversely into the receiving portion 2 with respect to the cutting direction, and in the inserted state, as exemplary shown in FIG. 2, it can rotate between the insertion position and the cutting position. The cutting insert 3 is fixed at the cutting position shown on the left side in FIG. 2 by a rotation prevention device formed as a tension spring 10 in this embodiment. The tension spring 10 is inserted into the cavity 11 of the carrier 1, supported by two side surfaces 12 of the cavity 11, and abuts against the cylindrical cutting substrate 4.

[0021] Furthermore, a lock catch for the tension spring 10 at the cutting position is arranged around the cylinder of the cutting insert 3. In this case, the lock catch constitutes a semi-kidney-shaped catch guide groove 13 having a lower receiving arc 14 and a higher tensioning arc 15 extending over the peripheral portion of the cutting substrate 4. At the insertion position shown on the right side in FIG. 2, the tension spring 10 engages with the lower receiving arc with play at its abutting portion 16. When the cutting insert 3 or the carrier 1 is rotated to the cutting position shown on the left side in FIG. 2, the abutting portion 16 slides to the higher tensioning arc 15 while abutting against the semi-kidney-shaped catch guide groove 13 and is frictionally engaged and thus fixed there.

[0022] Referring to FIGS. 3 and 4, according to this embodiment, it can be seen that a nose 18 that can be inserted into the undercut groove 17 of the receiving portion 2 is provided around the cylinder of the cutting insert 3. In this case, the undercut groove 17 includes a first insertion guide groove 19 that extends parallel to the cylinder axis of the receiving portion 2 based on a bayonet lock. A second rotation guide groove 20 is connected to the first insertion guide groove in the circumferential direction of the cylinder of the receiving portion 2 transverse to the first insertion guide groove. Therefore, when inserting the cutting insert 3 into the receiving portion 2, first, the nose 18 can move along the insertion guide groove 19, so that the cutting insert 3 occupies an insertion position in the receiving portion 2. When the cutting insert 3 and the receiving portion 2 are rotated in opposite directions with respect to the cylinder axis, the nose 18 can slide along the rotation guide groove 20, so that the cutting insert 3 occupies a cutting position with respect to the receiving portion 2. As can be seen from FIG. 4, the nose 18 is formed, for example, as a kind of cam whose surfaces are inclined with respect to each other and around the cylinder of the cutting insert 3. Therefore, the cross-section of the insertion guide groove 19 substantially coincides with the longitudinal cross-section of the nose 18 formed in a cam shape typically, while the cross-section of the rotation guide groove 20 substantially coincides with the cross-section of the nose 18, and the nose 18 has play and can move along the grooves 19 and 20.

[0023] Similarly, as can be seen from FIGS. 3 and 4, the stopper 6 on the back side of the cutting edge includes two stopper surfaces 21 that are inclined with respect to each other for centering the cutting insert 2 at the stopper jaw 8. Therefore, the stopper jaw also has two inclined stopper surfaces 22. The corresponding stopper jaw 9 that faces the stopper 6 with respect to the cylinder axis of the cutting substrate 4 also includes stopper surfaces 23 or 24 that are inclined with respect to each other.

[0024] Furthermore, in FIGS. 3 and 4, it can be observed that the tensioning spring 10 is inserted into the guide receiving portion 25 on the side surface 12 of the cavity 11.

[0025] The cutting inserts 3 can each be easily inserted by hand or removed again with a suitable insertion tool in a state of being incorporated in the cylindrical receiving part 2 in the cutting tool. In Fig. 2, a driver profile 26 for an exemplary insertion tool is schematically shown. Note that although this application relates to the invention described in the claims, the following may also be included as other aspects. 1. A cutting tool, particularly a saw blade, having a carrier (1) and a cutting insert (3), wherein the carrier (1) constitutes at least one cylindrical accommodation part (2) and at least one stopper jaw (8) for the cutting insert (3), the cutting insert (3) has a cylindrical cutting substrate (4) and a cutting edge (5) protruding radially from this cutting substrate, this cutting edge has at least one stopper (6) for the stopper jaw (8) on the back side of the cutting edge, the cutting insert (3) can be inserted horizontally into the accommodation part (2) with respect to the cutting direction and can rotate between the insertion position and the cutting position in the inserted state, and the cutting insert (3) is fixed at the cutting position by a rotation prevention device. A cutting tool, characterized in that the cutting insert (3) is inserted into the cylindrical accommodation part (2) in a bayonet lock manner. 2. The cutting tool according to item 1 above, characterized in that at least one nose (18) that can be inserted into the undercut groove (17) of the accommodation part (2) is provided around the cylinder of the cutting insert (3). 3. The cutting tool according to item 1 above, characterized in that at least one nose that can be inserted into the undercut groove of the cutting insert (3) is provided around the cylinder inside the accommodation part (2). 4. The cutting tool according to any one of items 1 to 3 above, characterized in that the cutting edge (5) has two stopper surfaces (21) arranged obliquely to each other for centering the cutting insert (3) at the stopper jaw (8) on the back side of the cutting edge. 5. The cutting tool according to item 4 above, characterized in that the cutting insert (3) has two stoppers (6, 7) distributed over its cylinder circumference for centering the cutting insert (3) at two stopper jaws (8, 9), and these stoppers (6, 7) face each other with respect to the cylinder axis of the cylindrical cutting substrate (4). 6. The cutting tool according to any one of items 1 to 5 above, characterized in that the carrier (1) has a space (11) for a rotation prevention device that connects around the cylinder inside the accommodation part (2) and faces the stopper jaw (8). 7. The anti-rotation device is constituted by a tension spring (10) which is supported on two side surfaces (12) of a cavity (11) on one hand and abuts against a cylindrical cutting substrate (4) on the other hand, the cutting tool according to item 6 above, characterized in that. 8. A locking catch for preventing rotation at the cutting position is arranged around the cylinder of the cutting insert (3), the cutting tool according to item 6 or 7 above, characterized in that. 9. The tension spring (10) is inserted into a guide housing portion (25) on the side surface (12) of the cavity (11), the cutting tool according to item 7 or 8 above, characterized in that. 10. In a cutting insert (3) for a cutting tool, having a cylindrical cutting substrate (4) and a cutting edge (5) protruding radially from this cutting substrate, and this cutting edge having at least one stopper (6) for a stopper jaw (8) on the back side of the cutting edge. At least one nose (18) and / or at least one groove (17) are arranged around the cylinder of the cutting insert (3), and this at least one nose (18) and / or at least one groove (17) are formed such that the cutting insert (3) can be inserted into the housing portion (2) of the tool in a bayonet lock manner, a cutting insert characterized in that. 11. The cutting edge (5) has two stopper surfaces (21) arranged obliquely to each other on the back side of the cutting edge for centering the cutting insert (3) in the cylindrical housing portion (2) of the tool, the cutting insert according to item 10 above, characterized in that. 12. The cutting insert (3) has two stoppers (6, 7) distributed around the cylinder of the cutting substrate (4) for centering the cutting insert (3) in the cylindrical housing portion (2) of the tool, and these stoppers (6, 7) face each other with respect to the cylinder axis of the cutting substrate (4), the cutting insert according to item 10 or 11 above, characterized in that. 13. A locking catch for preventing rotation at the cutting position is arranged around the cylinder of the cutting substrate (4), the cutting insert according to any one of items 10 to 12 above, characterized in that. 14. The locking catch constitutes a semi-kidney-shaped catch guide groove (13) having a lower accommodation arc (14) and a higher tension arc (15) extending over a peripheral portion of the cutting substrate (4), the cutting insert according to item 13 above, characterized in that.

Claims

1. A cutting tool having a carrier (1) and a cutting insert (3), wherein the carrier (1) forms at least one receiving portion (2) and at least one stopper jaw (8) for the cutting insert (3), the cutting insert (3) having a cutting substrate (4) and a cutting edge (5) protruding radially from the cutting substrate, the cutting edge having at least one stopper (6) for the stopper jaw (8) on the back side of the cutting edge, the receiving portion (2) having an inner peripheral portion formed in a cylindrical shape for rotatably receiving the cutting insert (3), the cutting substrate (4) having an outer peripheral portion formed in a cylindrical shape corresponding to the receiving portion (2), the cutting insert (3) being insertable into the receiving portion (2) transversely to the cutting direction, i.e., parallel to the carrier rotation axis, and being rotatable between the insertion position and the cutting position in the inserted state, the cutting insert (3) being fixed at the cutting position by a rotation prevention device, and the cutting insert (3) being inserted into the receiving portion (2) in a bayonet lock manner, particularly in a saw blade. The carrier (1) is provided with a space (11) for a rotation prevention device facing the stopper jaw (8) and connecting around the cylinder inside the receiving portion (2), and the rotation prevention device is constituted by a tension spring (10) supported on two side surfaces (12) of the space (11) on one hand and abutting against the cutting substrate (4) on the other hand. A cutting tool characterized by this.

2. At least one nose (18) insertable into an undercut groove (17) of the receiving portion (2) is provided around the cylinder of the cutting insert (3). The cutting tool according to claim 1, characterized by this.

3. At least one nose insertable into an undercut groove of the cutting insert (3) is provided around the cylinder inside the receiving portion (2). The cutting tool according to claim 1, characterized by this.

4. The cutting edge (5) has two stopper surfaces (21) arranged obliquely to each other for centering the cutting insert (3) at the stopper jaw (8) on the back side of the cutting edge. The cutting tool according to any one of claims 1 to 3, characterized by this.

5. The cutting insert (3) comprises two stoppers (6, 7) distributed over its cylinder circumference for centering the cutting insert (3) at two stopper jaws (8, 9), and these stoppers (6, 7) face each other with respect to the cylinder axis of the cutting substrate (4). The cutting tool according to claim 4, characterized in that.

6. A locking catch for preventing rotation at the cutting position is arranged around the cylinder of the cutting insert (3). The cutting tool according to any one of claims 1 to 5, characterized in that.

7. The tensioning spring (10) is inserted into the guide receiving part (25) at the side surface (12) of the cavity (11). The cutting tool according to any one of claims 1 to 6, characterized in that.

8. A cutting substrate (4) having a cutting edge (5) protruding radially from this cutting substrate, and this cutting edge has at least one stopper (6) for a stopper jaw (8) on the back side of the cutting edge. The cutting substrate (4) is provided with an outer peripheral portion formed in a cylindrical shape so as to correspond to a tool receiving portion (2) having an inner peripheral portion formed in a cylindrical shape for rotatably receiving the cutting insert (3). At least one nose (18) and / or at least one groove (17) are arranged around the cylinder of the cutting insert (3), and this at least one nose (18) and / or at least one groove (17) are formed so that the cutting insert (3) can be inserted into the tool receiving portion (2) in a bayonet lock manner. In the cutting insert (3) for a cutting tool, A locking catch for preventing rotation at the cutting position is arranged around the cylinder of the cutting substrate (4), and the locking catch constitutes a catch guide groove (13) having an inner receiving arc (14) and an outer tensioning arc (15) extending over the peripheral portion of the cutting substrate (4). A cutting insert characterized by that.

9. The cutting edge (5) is provided with two stopper surfaces (21) arranged obliquely to each other on the back side of the cutting edge for centering the cutting insert (3) in the tool receiving portion (2). The cutting insert according to claim 8, characterized in that.

10. The cutting insert (3) comprises two stoppers (6, 7) distributed over the circumference of the cylinder of the cutting substrate (4) for centering the cutting insert (3) within the receiving part (2) of the tool, these stoppers (6, 7) being opposed to each other with respect to the cylinder axis of the cutting substrate (4), the cutting insert according to claim 8 or 9, characterized in that.

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