RU2754916C1 - Cutting insert for modular mill and mill for use - Google Patents

Abstract

FIELD: materials processing.

SUBSTANCE: inventions group relates to the processing of materials by cutting and can be used in the processing of gears with an assembled cutting tool. The cutting plate contains two opposite end surfaces, between which there is a side surface containing a supporting and an opposite rear surface, as well as auxiliary side surfaces located between them. The axis of symmetry of the plate is located perpendicular to the support surface and coincides with the axis of the through fastening hole passing between the support surface and the rear surface. The insert contains at least two main cutting edges at the intersection of the front and rear surfaces. In the top view of the rear surface, the cutting plate has the shape of a rectangle, and on the rear surface, on both sides of the mounting hole along the axis of symmetry of the plate, there are grooves open to the auxiliary side surfaces. The design features of the cutting insert, as well as the modular cutter, containing the cutting inserts of the specified design installed in its nests are disclosed.

EFFECT: invention increases durability of cutting inserts and cutters.

9 cl, 6 dwg

Description

The field of technology.

The present invention relates to the field of machining materials by cutting, in particular to an assembled gear cutting cutting tool, namely to modular cutters and cutting inserts for them, and includes a group of inventions.

State of the art.

For productive milling of gears, modular milling cutters with mechanical fastening of replaceable cutting inserts of various shapes are used.

In addition to the technological requirements due to the shape and size of the gearing, the cutters under consideration are subject to increased requirements for the mechanical strength of their bodies and the main cutting plates, which form the surfaces of the gearing and have large geometric dimensions, including a large length that significantly exceeds their width. This significantly affects the strength of the inserts and the conditions for their fixing in the sockets of the cutter body.

In the process of milling gear parts, especially those with large modules, the cutting inserts are installed with overlap and they are subjected to enhanced thermomechanical action, which leads to a complex stress-strain state of the cutting edges and the cutting inserts themselves. This must be taken into account in the design of both the inserts for fixing the inserts and the cutting inserts themselves.

At the same time, in conditions of significant overall dimensions of the cutting plates and their attachment points, it is necessary to ensure the mechanical strength of these structural elements and the reliability of the fastening of the plates, while maintaining the maximum number of their cutting edges, and also to ensure the possibility of obtaining cutting inserts with different radii of curvature from one workpiece, taking into account the installation them in one overlap cutter body.

Known designs of modular cutters (see, for example, patents RU No. 2465989, No. 70474), containing a housing in the sockets of which indexed tangential cutting inserts are installed. In this case, the main shaping plates are located in the slots on the opposite end sides of the body, and their main cutting edges are located with overlap. Each socket has side reference surfaces and a base that is the reference surface. In this case, the cutting insert in each seat is fixed with a fastening screw through a fastening hole made in the central part of the seat.

The indicated designs of cutters and cutting inserts cannot be effectively used for milling gear elements with large modules. This is due to the insufficient durability of the main replaceable cutting inserts, which have large dimensions and, in particular, a large length in comparison with their width.

The object of the present invention is to provide a design of cutting inserts for modular cutters, which provides their increased efficiency and durability.

It is also an object of the present invention to provide a modular cutter design for using said cutting inserts.

The specified technical result is achieved through a set of features given in the corresponding claims.

Disclosure of the invention.

In accordance with the present invention, the cutting insert for a modular cutter comprises two opposing end faces as rake faces.

Between these surfaces there is a side surface containing a support surface and an opposing rear surface, as well as auxiliary side surfaces located between said surfaces.

The axis of symmetry of the cutting insert is located perpendicular to the support surface and coincides with the axis of the through-hole fastening hole passing between the support surface and the rear surface.

The cutting insert also contains at least two main cutting edges formed at the intersection of the leading and trailing surfaces.

In the top view of the rear surface, the cutting plate has the shape of a rectangle, and on the rear surface, on both sides of the mounting hole along the axis of symmetry of the plate, grooves are made, opening to the auxiliary side surfaces.

According to the invention, said grooves have a smaller width in the direction from the hole to the auxiliary side surfaces, and their side surfaces are located at sharp internal corners to the support surface of the plate,

In this case, bevels are made on the rear surface of the cutting insert between the main cutting edges and the side surfaces of the grooves, having a smaller width in the direction from the auxiliary side surfaces to the fastening hole.

Moreover, the lines of intersection of the side surfaces of the grooves with the indicated bevels in the top view of the rear surface are located on the sides of the large imaginary rhombus, and the lines of intersection of the grooves with their bottom are located on the sides of the small imaginary rhombus.

In this case, the axes of these rhombuses coincide with the axes of symmetry of the cutting insert, and the large diagonal of the large rhombus is greater than the diameter of the circle described around the plate in its top view on the rear surface, the minor axis of the large rhombus is greater than the diameter of the mounting hole, but less than the circle inscribed in the plate.

Moreover, the large diagonal of the small rhombus is greater than the length of the plate, but less than the diameter of the circle described around the plate in its top view of the rear surface, and the small diagonal of the small rhombus is less than the diameter of the mounting hole.

In accordance with one of the preferred embodiments of the cutting insert, the ratio of the lengths of the large diagonals, respectively, of the large rhombus to the small rhombus is selected from the range 1.1-1.9, and the ratio of the small diagonals of the respectively large rhombus to the small rhombus is selected from the range 2.1-3.1 ...

According to another preferred embodiment of the cutting insert, its rear surface is convex or concave or wavy.

In accordance with another preferred embodiment of the cutting insert, its side surfaces of the grooves are concave or convex.

In accordance with another preferred embodiment of the cutting insert, the ratio of its length to width is selected from the range of 1.4-2.3.

In accordance with another preferred embodiment of the cutting insert, on its rear surface, at least along one auxiliary side surface, a radius curvature is made, and on the supporting surface and at least one auxiliary side surface, a chamfer is made.

In accordance with another preferred embodiment of the cutting insert, its base is made of a hard alloy having a binder phase in a combination of cobalt with at least one of the metals Ir, Pd, Ru, Re, Rh, Os, and a wear-resistant a coating containing at least one layer that contains a phase with at least one of the elements V, Cr, Nb, Ti, Ta, Zr, Hf, B, Al, Si, C, N, O.

In accordance with another preferred embodiment of the cutting insert, its carbide base contains carbon nanotubes, which are randomly located throughout the volume of the insert, or at least some of them are oriented relative to the front and rear surfaces, and at least some of the carbon nanotubes have an outlet on the front and back surfaces and in contact with the wear-resistant coating.

In accordance with the invention, the modular milling cutter comprises a body in the form of a disk, in which slots are made on one and the other side of it for accommodating replaceable cutting inserts.

In this case, according to the invention, at least in several of the said pockets are placed tangentially and fixed by means of screws cutting inserts made according to any of the above items.

Moreover, the supporting surfaces of the cutting plates are in contact with the supporting surfaces of the sockets, their auxiliary side surfaces - with the side surfaces of the sockets, and one of the end surfaces of each cutting plate - with the tangential base of the sockets.

Brief description of the drawings.

For better understanding, but by way of example only, the invention will be described with reference to the accompanying drawings, which show an insert for a modular cutter and a cutter for use. Wherein:

in fig. 1 is a perspective view of a cutting insert for a modular cutter;

in fig. 2 is a top view of the rear surface of the insert of FIG. 1;

FIG. 3 is a sectional view taken along line I-I of the insert shown in FIG. 2;

in fig. 4 shows a section along line II-II of the cutting insert shown in FIG. 2;

in fig. 5 is a perspective view of the modular cutter with the inserts shown in FIG. 1.

in fig. 6 is a perspective view of a socket in a modular cutter body for holding the insert of FIG. 1;

Detailed description of the invention.

Consider the proposed design of the cutting insert 10 for a modular cutter shown in FIG. 1-4.

In this case, the cutting insert 10 for the modular cutter 50 contains two opposite end surfaces 12, which are the front surfaces.

Between the end surfaces there is a side surface containing the support surface 14 and an opposing rear surface 16, and between the said surfaces 14 and 16 there are auxiliary side surfaces 18.

The axis of symmetry 20 of the cutting insert 10 is located perpendicular to the bearing surface 14 and coincides with the axis of the through-fixing hole 22 passing between the bearing surface 14 and the rear surface 16.

The cutting insert contains at least two major cutting edges 24 formed at the intersection of the front 12 and rear 16 surfaces.

In this case, in a top view of the rear surface 16, the cutting insert has the shape of a rectangle, and grooves 26 are made on the rear surface 16 on both sides of the fastening hole 22 along the axis of symmetry of the plate 10, opening onto the auxiliary side surfaces 18.

According to the invention, said grooves 26 have a smaller width in the direction from the hole to the minor side surfaces 18, and their side surfaces 28 are located at sharp internal angles α to the support surface 14.

In this case, on the rear surface 16 between the main cutting edges 24 and the side surfaces of the grooves 26, bevels 28a and 28b are made, having a smaller width in the direction from the auxiliary side surfaces 18 to the fastening hole 22.

Moreover, the lines of intersection of the side surfaces of the grooves 26 with the indicated bevels 28a and 28b in a top view of the rear surface 16 are located on the sides of the large imaginary rhombus 30, and the lines of intersection of the grooves 26 with their bottom 32 are located on the sides of the small imaginary rhombus 34.

In this case, the axes of the above rhombuses coincide with the axes of symmetry of the cutting insert 10, and the large diagonal 36 of the large rhombus 30 is greater than the diameter of the circle 38 described around the insert 10 in its top view on the rear surface 16.

The minor axis 40 of the large rhombus 30 is larger than the diameter of the fastening hole 22, but less than the circle 42 inscribed in the plate 10.

In this case, the large diagonal 44 of the small rhombus 34 is greater than the length of the plate 10, but less than the diameter of the circle 38 described around the plate 10 in its top view of the rear surface 16, and the small diagonal 46 of the small rhombus 34 is less than the diameter of the fastening hole 22.

The above design features of the cutting insert 10 for a modular cutter can significantly improve its stress-strain state that occurs when milling teeth in gear parts. This makes it possible to increase the durability of these cutting inserts, especially when milling teeth in gear parts with large modules.

In addition, the shape and dimensions of the grooves 26, made on the side of the rear surface 16, make it possible to obtain from one workpiece cutting inserts with a different radius of curvature of the rear surface adjacent to the auxiliary side surfaces 18. At the same time, the reinforced section of the cutting insert in the rounding zone is maintained, which in its turn helps to increase the life of the cutting insert.

In accordance with one of the preferred embodiments of the cutting insert 10, the ratio of the lengths of the large diagonals 36 and 44, respectively, of the large rhombus 30 to the small rhombus 34 is selected from the range (1.1-1.9), and the ratio of the small diagonals 40 and 46, respectively, of the large rhombus 30 to small rhombus 34 is selected from the range 2.1-3.1.

In accordance with another preferred embodiment of the cutting insert 10, the ratio of its length to width is selected from the range of 1.4-2.3.

The above ranges of variation of the ratios of the diagonals of the imaginary rhombuses and the sizes of the cutting inserts are selected from the conditions for ensuring the milled profile of the teeth, as well as the strength and wear resistance of the cutting insert, both as a whole and its individual sections, including individual sections of the main cutting edges.

For example, increasing the upper limits of these ratios significantly increases the length of the cutting insert in relation to its width. At the same time, its strength characteristics are reduced, its durability and reliability of basing in the sockets of the modular cutter body also decreases, including taking into account the diameter of the mounting hole.

The above lower limits for changing the ratio of the diagonals of the imaginary rhombuses are also dictated primarily by the technological reasons for the use of cutting inserts.

In accordance with another preferred embodiment of the cutting insert, its rear surface 16 is convex or concave or wavy.

The profiling of the rear surface 16 of the cutting insert allows you to obtain the required profile of the cutting part of the insert and to place the inserts on the cutting part of a modular cutter for processing gear parts of a particular module. This further improves the performance properties of the proposed insert design.

In accordance with another preferred embodiment of the cutting insert, the side surfaces 28 of its grooves 26 are concave or convex.

This, on the one hand, makes it possible to improve the strength characteristics of the plates, and on the other hand, to make the plates more technological.

In accordance with another preferred embodiment of the cutting insert, on its rear surface 16, at least along one auxiliary side surface 18, a radius curvature 18a is made, and a chamfer 18b is made on the support surface 14 and at least one auxiliary side surface 18.

This design feature contributes to the achievement of the planned technical result, and also allows the manufacture of cutting inserts with a wide range of radii of corner cutting edges using one mold, which significantly increases the efficiency of the proposed design. In this case, cutting inserts can be used not only for processing the main surfaces of the teeth, but also for milling cavities, in particular on finishing mills.

The chamfers made on the supporting surface make it possible to ensure the unambiguity of the positioning of the cutting inserts in the sockets of the modular cutter body, and thereby further increase the operational properties of the proposed cutting inserts.

In accordance with another preferred embodiment of the cutting insert, its base is made of a hard alloy having a binder phase in a combination of cobalt with at least one of the metals Ir, Pd, Ru, Re, Rh, Os, and a wear-resistant a coating containing at least one layer that contains a phase with at least one of the elements V, Cr, Nb, Ti, Ta, Zr, Hf, B, Al, Si, C, N, O.

In accordance with another preferred embodiment of the cutting insert, the carbide base contains carbon nanotubes that are randomly located throughout the volume of the plate, or at least some of them are oriented relative to the front and rear surfaces, and at least part of the carbon nanotubes have an exit to the front and the back surface and contacts the wear-resistant coating.

The above preferred designs of the cutting insert can further increase their operational properties and, taking into account the proposed design features, to achieve the planned technical result of a higher level.

In accordance with the invention, there is provided a modular cutter 50, in particular shown in FIG. 5-6. It contains a housing in the form of a disc 52, in which on one and the other side of it there are slots 54 for accommodating replaceable cutting inserts.

According to the invention, at least in several of the said pockets 54 are placed tangentially and fixed by means of screws 56 cutting inserts 10 made according to any of the mentioned designs.

In this case, the abutment surfaces 14 of the cutting inserts 10 contact the abutment surfaces 58 of the nests 54, their auxiliary side surfaces 18 with the side surfaces 60 of the nests 54, and one of the end surfaces 12 of each cutting insert with the tangential base 62 of the nests 54.

In particular, in FIG. 5 shows a modular cutter 50, on which the cutting inserts 10 are installed, forming the main profile of the gearing and experiencing the greatest stress. At the same time, for processing the surfaces of the cavities between the teeth on the specified milling cutter, cutting inserts of a conventional design can be used, which does not reduce the effect of using cutting inserts of the proposed design and allows achieving the planned technical result, which also manifests itself in increasing the efficiency and durability of the proposed modular cutter.

It should also be understood that the proposed cutting inserts can be used, including on finishing modular cutters, both for processing the surfaces of the teeth and depressions.

Execution of the invention and description of its operation.

As an example, consider the use of a carbide cutting insert with a wear-resistant coating 24 mm long, 12.7 mm wide, 6.0 mm thick and the ratio of large and small diagonals of small and large rhombuses, respectively, equal to 1.7 and 2.7 and characterizing the dimensions of the grooves 26 ...

The indicated cutting inserts were mounted on finishing disk modular cutters with a diameter of 450 mm and the teeth of gear wheels with module m36, z = 12, were milled. The modular cutter as a whole showed good performance and productivity in obtaining the required profile of the gearing, while the cutting inserts showed high durability. At the same time, the cutting inserts and the cutter as a whole showed good performance and durability in a wide range of cutting speeds from 80 to 250 m / min. and feeds per tooth from 0.15 to 0.4 mm, thereby achieving the planned technical result.

Although the present invention has been described with a certain degree of detail, it should be understood that various changes and modifications can be made without departing from the spirit and scope of the invention set forth in the following claims.

Claims (9)

1. A cutting insert (10) for a modular cutter (50), containing two opposite end surfaces (12), which are front surfaces, between which there is a side surface containing a support surface (14) and an opposing back surface (16) located between by said surfaces (14, 16), auxiliary side surfaces (18), an axis of symmetry (20) located perpendicular to the support surface (14) and coinciding with the axis of the through fastening hole (22) passing between the support surface (14) and the rear surface (16 ), and at least two main cutting edges (24) formed at the intersection of the front (12) and rear (16) surfaces, while in the top view of the rear surface (16) the cutting insert has the shape of a rectangle, and on the rear surface ( 16) on both sides of the fastening hole (22) along the axis of symmetry of the plate (10), grooves (26) are made, open to the auxiliary side surfaces (18), characterized in that the the grooves (26) have a smaller width in the direction from the specified hole to the auxiliary side surfaces (18), and their side surfaces (28) are located at sharp internal angles (α) to the support surface (14), while on the rear surface (16 ) between the main cutting edges (24) and the side surfaces of the grooves (26), bevels (28a, 28b) are made, having a smaller width in the direction from the auxiliary side surfaces (18) to the fastening hole (22), and the lines of intersection of the side surfaces of the grooves (26 ) with the indicated bevels (28a, 28b) in the top view of the back surface (16) are located on the sides of the large imaginary rhombus (30), and the lines of intersection of the grooves (26) with their bottom (32) are located on the sides of the small imaginary rhombus (34) , and the axes of these rhombuses coincide with the axes of symmetry of the cutting insert (10), and the large diagonal (36) of the large rhombus (30) is greater than the diameter of the circle (38) described around the plate (10) in its top view of the rear surface (16), minor axis (40) of the large rhombus (30) is larger than the diameter of the mounting hole (22), but less than the circle (42) inscribed in the plate (10), while the large diagonal (44) of the small rhombus (34) is greater than the length of the plate (10), but less than the diameter of the circle (38) described around the plate (10) in its top view on the rear surface (16), and the small diagonal (46) of the small rhombus (34) is less than the diameter of the fastening hole (22). 2. A cutting insert (10) according to claim 1, characterized in that the ratio of the lengths of the large diagonals (36, 44), respectively, of the large rhombus (30) to the small rhombus (34) is selected from the range 1.1-1.9, and the ratio small diagonals (40, 46), respectively, of the large rhombus (30) to the small rhombus (34) is selected from the range 2.1-3.1. 3. A cutting insert (10) according to claim 1, characterized in that its rear surface (16) is convex, concave or wavy. 4. A cutting insert (10) according to claim 1, characterized in that the lateral surfaces (28) of the grooves (26) are concave or convex. 5. The cutting insert (10) according to claim 1, characterized in that the ratio of its length and width is selected from the range 1.4-2.3. 6. A cutting insert (10) according to claim 1, characterized in that on the rear surface (16) at least along one auxiliary side surface (18) a radius rounding (18a) is made, and on the support surface (14) and at least at least one auxiliary side surface (18) is chamfered (18b). 7. The cutting insert (10) according to any one of paragraphs. 1-6, characterized in that its base is made of a hard alloy having a binder phase in a combination of cobalt with at least one of the metals Ir, Pd, Ru, Re, Rh, Os, and a wear-resistant coating is additionally applied to its working surfaces, containing at least one layer that contains a phase with at least one of the elements V, Cr, Nb, Ti, Ta, Zr, Hf, B, Al, Si, C, N, O. 8. A cutting insert (10) according to claim 7, characterized in that its hard-alloy base contains carbon nanotubes, which are randomly arranged throughout the volume of the plate, or at least some of them are oriented relative to the front and rear surfaces, while at least part of the carbon The nanotubes have an exit to the front and back surfaces and are in contact with a wear-resistant coating. 9. Modular cutter (50), containing a body in the form of a disk (52), in which on one and the other sides of it there are nests (54) for accommodating replaceable cutting inserts, characterized in that at least several of these nests (54) placed tangentially and fixed by means of screws (56) cutting plates (10), made according to one of paragraphs. 1-8, while the supporting surfaces (14) of the cutting inserts (10) are in contact with the supporting surfaces (58) of the slots (54), their auxiliary side surfaces (18) - with the side surfaces (60) of the slots (54), and one of end surfaces (12) of each cutting insert - with tangential base (62) sockets (54).

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