Tool holder device

Abstract

Tool holder device A tool holder device (1), comprising a tool holder body (2) extending along a device axis (3), between a front end (4) and an opposite rear end (5), wherein the tool holder body (2) comprises a housing body (6), formed at the front end (4), and an opposite insertion body (7), formed at the rear end (5), wherein the housing body (6) is shaped so as to define a housing seat (8) adapted to accommodate a machining tool (9), wherein the insertion body (7) defines an outer insertion surface (10), coaxial to the device axis (3) and facing away from the device axis (3), wherein the outer insertion surface (10) is frustoconical in shape, and wherein the section of the outer insertion surface (10) is reduced towards the rear end (5), wherein the tool holder device (1) comprises a fastening element (11), comprising a fastening wall (12), wherein the fastening wall (12) is coaxial to the device axis (3) and defines an inner fastening surface (13) facing the device axis (3), which defines a fastening seat (14), wherein the fastening wall (12) of the fastening element (11) is fitted onto the insertion body (7) at the rear end (5), so that the inner fastening surface (13) faces the outer insertion surface (10), and wherein the inner fastening surface (13) has a frustoconical shape consistent with the frustoconical shape of the outer insertion surface (10), and wherein the tool holder device (1) comprises actuation means (15), configured to translate the fastening element (11) relative to the insertion body (7), along the device axis (3).

Description

Tool holder device

[0001] Field of the invention

[0002] The present invention relates to a tool holder device, in particular a tool holder device adapted to be inserted into and connected inside a machine tool for operations of mechanical machining by chip removal.

[0003] Background art

[0004] Machine tools for operations of mechanical machining by chip removal are known, e.g., lathes and cutters, comprising a mandrel or a tool holder to which a machining tool is mountable, such as drilling tips, cutters, reamers, borers, enlargers and the like.

[0005] The machining tool is generally housed in a tool holder device which is fastened to a mandrel or any other bracketing structure (tool holder turrets, etc.), in particular inserted into a suitable cylindrical seat formed at the end of the mandrel or on board the turret.

[0006] Generally, this seat has a cylindrical shape which is coaxial to the symmetry axis of the tool.

[0007] In order to perform correct and accurate mechanical machining, there is a need to firmly fasten the tool holder, with which the machining tool is associated, to the mandrel or tool holder turret.

[0008] Moreover, the need is known to center the machining tool, and therefore the tool holder, so as to ensure the coaxiality between tool, tool holder and mandrel axis. Indeed, a machining tool which is not coaxial with the mandrel would cause a discrepancy between the initial machining project and the final results obtained on the machined item.

[0009] Tool holder devices are known which form a seat for receiving a machining tool, and which are insertable into and fastenable inside a cylindrical seat by means of a plurality of tightening screws inserted transversely to the mandrel axis and configured to abut against the tool holder, pressing it and fastening it against an opposite portion of the inner wall of the mandrel seat.

[0010] Such known devices and tightening means do not ensure a correct concentricity between tool holder device and mandrel seat.

[0011] Hydraulic expansion tool holder devices are also known, configured to expand into a cylindrical seat by means of a compression of a hydraulic fluid contained therein, which achieves the fastening with the seat itself.

[0012] Such known devices allow achieving a correct coaxiality between tool holder device and cylindrical seat of the mandrel or turret due to the axisymmetric expansion of the outer surface of the tool holder device into the cylindrical seat of the mandrel or turret. However, such known devices have increased complexities and costs due to the management of the hydraulic fluid therein.

[0013] Therefore, the need is felt to provide an improved tool holder device adapted to be fastened in a cylindrical seat at the end of a mandrel or on board a tool holder turret, thus achieving a correct coaxiality between the tool holder device and the cylindrical seat of the mandrel or turret.

[0014] The need is also felt to provide an improved tool holder device adapted to ensure the correct concentricity with the mandrel, while having increased operating, production and assembly simplicity, as well as low costs.

[0015] Solution

[0016] It is the object of the present invention to provide an improved tool holder device adapted to solve at least some of the drawbacks of the prior art.

[0017] It is a particular object of the present invention to provide a tool holder device adapted to be connectable to a machine tool for operations of mechanical machining by chip removal, ensuring a correct coaxiality with the cylindrical seat of the mandrel or tool holder turret.

[0018] It is a further object of the present invention to provide a tool holder device adapted to be connectable to a machine tool for operations of mechanical machining by chip removal, and in particular to a mandrel of the machine tool or to a tool holder turret, having increased operating, production and assembly simplicity, as well as low costs.

[0019] These and other objects are achieved by a tool holder device according to claim 1.

[0020] The dependent claims relate to preferred and advantageous embodiments of the present invention.

[0021] Figures

[0022] In order to better understand the invention and appreciate the advantages thereof, some non-limiting exemplary embodiments thereof will be described below with reference to the accompanying drawings, in which:

[0023] - Figure 1 is a perspective view of a tool holder device, with which a tool is associated, according to an embodiment of the invention;

[0024] - Figure 2 is an exploded perspective view of the tool holder device with whicha tool is associated, depicted in Figure 1 ;

[0025] - Figure 3 is an axial section view of the tool holder device with which a tool is associated, depicted in Figure 1 , in a first operating configuration;

[0026] - Figure 4 is an axial section view of the tool holder device with which a tool is associated, depicted in Figure 1 , in a second operating configuration;

[0027] - Figure 5 is a side view of a tool holder device, according to an embodiment of the invention;

[0028] - Figure 6 is an axial section view of the tool holder device depicted in Figure5;

[0029] - Figure 7 is a front view of the tool holder device depicted in Figure 5;

[0030] - Figure 8 is a rear view of the tool holder device depicted in Figure 5;

[0031] - Figure 9 is a perspective view of a tool holder device, according to an embodiment of the invention;

[0032] - Figure 10 is an exploded perspective view of the tool holder device depicted in Figure 9;

[0033] - Figure 11 is an exploded side view of the tool holder device depicted in Figure9;

[0034] - Figure 12 is an axial section side view of the tool holder device depicted inFigure 9;

[0035] - Figure 13 is a side view of the tool holder device depicted in Figure 9, in a first operating configuration;

[0036] - Figure 14 is a side view of the tool holder device depicted in Figure 9, in a second operating configuration;

[0037] - Figure 15 is an exploded perspective view of a tool holder device, according to a further embodiment of the invention;

[0038] - Figure 16 is a side perspective view of the tool holder device depicted inFigure 15.

[0039] Description of some preferred embodiments

[0040] With reference to the figures, a tool holder device is generally indicated by reference numeral 1 .

[0041] The tool holder device 1 is adapted to be mounted on a machine tool for operations of mechanical machining by chip removal, and in particular inserted into and tightened inside a seat of a tool holder or of the mandrel itself of the machine tool.

[0042] The tool holder device 1 comprises a tool holder body 2.

[0043] The tool holder body 2 extends along a device axis 3, between a front end 4 and an opposite rear end 5. The tool holder body is coaxial to the device axis 3.

[0044] The tool holder body 2 comprises a housing body 6 formed at the front end 4.

[0045] The housing body 6 is shaped so as to define a housing seat 8 adapted to accommodate a machining tool 9. By way of example, the housing seat 8 can be shaped with any shape so as to accommodate any tool or component adapted to ensure or adapt the fastening of the tool under machining to the tool holder device 1 .

[0046] Opposite to the housing body 6, the tool holder body 2 comprises an insertion body 7.

[0047] The insertion body 7 is formed at the rear end 5.

[0048] The insertion body 7 is adapted to be mounted on the machine tool for operations of mechanical machining by chip removal, and in particular to be inserted into a cylindrical seat of a tool holder or of the mandrel itself.

[0049] The insertion body 7 defines an outer insertion surface 10. The outer insertion surface 10 is coaxial to the device axis 3 and faces away from the device axis 3.

[0050] The outer insertion surface 10 is frustoconical in shape. Specifically, the section of the outer insertion surface 10 is reduced towards the rear end 5, i.e., in the direction of the rear end 5. “Section” means a section of the outer insertion surface 10 which is transverse to the device axis 3.

[0051] The tool holder device 1 further comprises a fastening element 1 1 comprising a fastening wall 12.

[0052] The fastening wall 12 is coaxial to the device axis 3. Moreover, the fastening wall 12 defines an inner fastening surface 13 facing the device axis 3.

[0053] Preferably, the fastening wall 12 extends substantially parallel to the device axis 3.

[0054] The inner fastening surface 13 defines a fastening seat 14.

[0055] The fastening wall 12 of the fastening element 11 is fitted onto the insertion body 7, at the rear end 5 of the tool holder body 2.

[0056] The insertion body 7 is thus inserted into the fastening seat 14. Moreover, the inner fastening surface 13 thus faces the outer insertion surface 10.

[0057] The inner fastening surface 13 has a frustoconical shape consistent with the frustoconical shape of the outer insertion surface 10. “Consistent” means that the taper of the inner fastening surface 13 is consistent with the taper of the outer insertion surface 10, i.e., the inner fastening surface 13 and the outer insertion surface 10 aregeometrically couplable.

[0058] Moreover, the tool holder device 1 comprises actuation means 15.

[0059] The actuation means 15 are configured to translate the fastening element 1 1 relative to the insertion body 7, along the device axis 3.

[0060] Advantageously, a tool holder device 1 thus configured ensures a strong connection which is correctly concentric with the machine tool mandrel. With added advantage, the tool holder device 1 thus configured has increased operating, production and assembly simplicity as compared to the prior art, as well as low costs.

[0061] According to an embodiment, the fastening element 1 1 fitted on the insertion body 7 is further translatable along the device axis 3 towards the front end 4 of the tool holder body 2 so as to generate an interference coupling with the outer insertion surface 10 of the insertion body 7.

[0062] Specifically, the actuation means 15 are configured to translate the fastening element 1 1 relatively to the insertion body 7, along the device axis 3, so as to wedge with interference the insertion body 7 within the fastening wall 12.

[0063] According to an embodiment, the fastening wall 1 1 extends between a first end 16 and an opposite second end 17.

[0064] In the configuration in which the fastening element 1 1 is fitted on the insertion body 7, the first end 16 faces the front end 4 of the tool holder body 2, while the second end 17 is opposite to the front end 4.

[0065] According to an embodiment, the fastening wall 12 is configured to be translatable relative to the insertion body 7 over a length x of the insertion body 7, measured along the device axis 3, without undergoing a plastic deformation.

[0066] Preferably, length x is shorter than the total length L of the insertion body 7.

[0067] According to an embodiment, the fastening wall 12 is configured to be translatable relative to the insertion body 7 over a first length x1 of the insertion body 7, where x1 < x, without undergoing a substantial elastic deformation.

[0068] Moreover, the fastening wall 12 is configured to be translatable relative to the insertion body 7 by a second length x2 of the insertion body 7, further and subsequent to the first length x1 , undergoing an elastic deformation.

[0069] Preferably, such an elastic deformation of the fastening wall 12 consists of an axial elastic compression and a radial bulging, or consists of a radial expansion, with reference to the device axis 3.

[0070] Advantageously, such an elastic deformation is substantially axisymmetric.With added advantage, such an axisymmetric elastic deformation of the fastening wall 12, when caused inside a cylindrical seat, generates a coupling by interference with the seat itself and adapts geometrically to the inner shape of the seat, generally cylindrical, thus creating a strong and concentric fastening of the tool holder device 1 to the seat of the tool holder or of a mandrel.

[0071] According to an embodiment, the fastening wall 12 is configured to be translatable relative to the insertion body 7 by a first length x1 of the insertion body 7, where x1 < x, without a reduction of the distance between the first end 16 and the second end 17 of the fastening wall 12, along an axis parallel to the device axis 3, causable by an elastic deformation of the fastening wall 12.

[0072] Moreover, the fastening wall 12 is configured to be translatable relative to the insertion body 7 by a second length x2 of the insertion body 7, further and subsequent to the first length x1 , undergoing an elastic deformation which generates a reduction of the distance between the first end 16 and the second end 17 of the fastening wall 12, i.e., a nearing between the first end 16 and the second end 17 along a direction parallel to the device axis 3.

[0073] Such a reduction of the distance of the first end 16 and the second end 17, caused by the elastic deformation of the fastening wall 12, generates a bulging of the fastening wall 12.

[0074] Accordingly, during the translation along the second length x2, the fastening wall 12 takes a bulging, convex shape, with reference to the device axis 3.

[0075] Advantageously, such a bulging is substantially axisymmetric. With added advantage, such an axisymmetric bulging of the fastening wall 12, when caused inside a cylindrical seat, generates a coupling by interference with the seat itself and adapts geometrically to the inner shape, generally cylindrical, thus creating a strong and concentric fastening of the tool holder device 1 to the seat of the tool holder or of a mandrel.

[0076] In particular, the reduction of the distance between the first end 16 and the second end 17 is caused by the interference between the outer insertion surface 10 of the insertion body 7 and the inner fastening surface 13 of the fastening wall 12, which tends to cause a jamming of the first end 16 of the fastening wall 12 against the insertion body 7.

[0077] With added advantage, the bulging allows obtaining a greater deformation than a radial expansion, and a consequent increased tightening force between the tool holder device 1 and the tightening system, in particular the tool holder machine.

[0078] According to an alternative embodiment, the fastening wall 12 is configured to be translatable relative to the insertion body 7 by a first length x1 of the insertion body 7, where x1 < x, without undergoing a substantial elastic deformation and without undergoing a reduction in the distance between the first end 16 and the second end 17 of the fastening wall 12, along an axis parallel to the device axis 3.

[0079] Moreover, the fastening wall 12 is configured to be translatable relative to the insertion body 7 by a second length x2 of the insertion body 7, further and subsequent to the first length x1 , undergoing an elastic deformation which generates a radial expansion of the fastening wall 12, but without undergoing a reduction in the distance between the first end 16 and the second end 17 of the fastening wall 12, i.e., without undergoing a nearing between the first end 16 and the second end 17 along a direction parallel to the device axis 3.

[0080] Accordingly, during the translation along the second length x2, the fastening wall 12 expands in radial direction to the device axis 3.

[0081] Advantageously, such an expansion is substantially axisymmetric. With added advantage, such an axisymmetric expansion of the fastening wall 12, when caused inside a cylindrical seat, generates a coupling by interference with the seat itself and adapts geometrically to the inner shape, generally cylindrical, thus creating a strong and concentric fastening of the tool holder device 1 to the seat of the tool holder or of a mandrel.

[0082] With added advantage, the radial expansion allows obtaining improved coaxiality and concentricity as compared to a bulging, between the tool holder device 1 and the tightening system, in particular the tool holder machine.

[0083] According to an embodiment, the translation of the fastening wall 12 along the second length x2 is operable by the actuation means 15.

[0084] Preferably, x2 < x1 .

[0085] According to an embodiment, x1 + x2 = x.

[0086] According to an embodiment, x1 is of between 80-90% of L. Preferably, x1 is of between 80-85% of L.

[0087] According to an embodiment, x2 is of between 10-19% of L. Preferably, x2 is of between 10-15% of L.

[0088] According to an embodiment, x1 +x2 is of between 90-99% of L. Preferably, x1 +x2 is of between 90-95% of L.

[0089] According to an embodiment, the fastening wall 12 defines an outer fasteningsurface 18, opposite to the inner fastening surface 13. Specifically, the outer fastening surface 18 faces away from the device axis 3.

[0090] According to an embodiment, the outer fastening surface 18 is cylindrical in shape. Specifically, the outer fastening surface 18 extends coaxial and parallel to the device axis 3.

[0091] Advantageously, the outer fastening surface 18 thus configured facilitates inserting the fastening wall 12 into a cylindrical seat.

[0092] According to this embodiment, the thickness of the fastening wall 12, in a direction transverse to the device axis 3, increases towards the second end 17 of the fastening wall 12.

[0093] According to an embodiment, the thickness of the fastening wall 12, in a direction transverse to the device axis 3, is minimal at the first end 16 of the fastening wall 12.

[0094] According to an embodiment, the thickness of the fastening wall 12, in a direction transverse to the device axis 3, is maximum at the second end 17 of the fastening wall 12.

[0095] According to an embodiment, the taper angle of the outer insertion surface 10 is substantially identical to and matches the taper angle of the inner fastening surface 13, which are measured with reference to the device axis 3.

[0096] According to an embodiment, the fastening wall 12 defines a plurality of notches 19.

[0097] Each notch 19 extends passing through the fastening wall 12. Therefore, each notch 19 extends between the inner fastening surface 13 and the opposite outer fastening surface 18.

[0098] According to an embodiment, each notch 19 extends along a direction parallel to the device axis 3.

[0099] Advantageously, the notches 19 facilitate the elastic deformation of the fastening wall 12 and guides the elastic deformation of the fastening wall 12, creating a guided, controlled, foreseeable and axisymmetric expansion or bulging of the fastening wall 12.

[0100] According to an embodiment, each notch 19 extends between a first notch end 20 and a second notch end 21 , included within the fastening wall 12. According to this embodiment, the notches 19 are included in the axial extension of the fastening wall 12, not opening at the first or second end 16, 17 of the fastening wall 12.

[0101] According to an embodiment, each notch 19 forms a linear slot extending between the first notch end 20 and the second notch end 21 . Moreover, notch 19 forms an enlarged notch portion at the second notch end 21 . According to an embodiment, the enlarged notch portion is substantially circular in shape. According to an embodiment, the first notch end 20 is not enlarged with respect to the linear slot enclosed between the first notch end 20 and the second notch end 21 .

[0102] According to an embodiment, the first notch ends 20 are positioned at the first end 16 of the fastening wall 12, while the second notch ends 21 are positioned at the first end 17 of the fastening wall 12. Accordingly, the notches 19 mutually mirror one another in a direction which is circumferential to the device axis 3 (Figures 1-14).

[0103] Advantageously, such a configuration facilitates the radial expansion of the fastening wall 12.

[0104] According to an embodiment, the notches 19 are positioned in an alternating and inverted manner in a direction which is circumferential to the device axis 3. Accordingly, the first notch ends 20 and the second notch ends 21 are positioned in alternating manner at the first end 16 or at the second end 17 (Figures 15-16). Specifically, the first notch end 20 of a first notch 19 is positioned between two second notch ends 21 of two adjacent notches 19 opposite to the first notch 19, and vice versa.

[0105] Advantageously, such a configuration facilitates the bulging of the fastening wall 12.

[0106] The notches 19 mutually define a plurality of wall bands 22, each enclosed between two respective notches 19.

[0107] Moreover, the fastening wall 12 defines a contact portion 23 enclosed between the first end 16 of the fastening wall 12 and the first notch ends 20 of the notches 19. Accordingly, the contact portion 23 is circumferentially continuous, without notches.

[0108] According to an embodiment, the fastening wall 12 defines a contact portion 23 also enclosed between the second end 17 of the fastening wall 12 and the second notch ends 21 of the notches 19.

[0109] Advantageously, such a configuration concentrates most of the elastic deformation of the fastening wall 12 at the wall bands 22. Accordingly, such a configuration facilitates an outwards expansion or bulging of the wall bands 22, creating a strong and concentric fastening between the fastening body 1 1 and the mandrel seat. Moreover, the failed or in any case smaller elastic deformation of the contact portion 23 of the fastening wall 12, of negligible extent with respect to the expansion or bulging of the wall bands 22, creates and preserves a strong and coaxial fastening between thefastening body 11 and the insertion body 7.

[0110] According to an embodiment, the fastening body 11 comprises a bottom wall24.

[0111] The bottom wall 24 is connected to the fastening wall 12 at the second end 17 of the fastening wall 12.

[0112] According to an embodiment, the bottom wall 24 extends transverse to the device axis 3, coaxial to the device axis 3.

[0113] The bottom wall 24 closes the fastening seat 14 of the fastening body 11 .

[0114] According to an embodiment, the actuation means 15 are connected to the fastening wall 24.

[0115] The fastening means 15 can thus actuate a translation of the fastening body 11 with respect to the insertion body 7, along the device axis 3.

[0116] According to an embodiment, the actuation means 15 comprise a drive screw25.

[0117] The drive screw 25 extends along the device axis 3.

[0118] The drive screw 25 extends between a head end 26 and an opposite tail end 27.

[0119] The head end 26 is positioned at the front end 4 of the tool holder body 2, while the tail end 27 is positioned at the rear end 5 of the tool holder body 2.

[0120] According to an embodiment, the tool holder body 2 comprises a through duct 28 extending along the device axis 3.

[0121] Specifically, the through duct 28 extends passing through the tool holder body 2, opening into the housing seat 8 and opening externally onto the rear end 5.

[0122] According to an embodiment, the drive screw 25 is positioned to be inserted into the through duct 28.

[0123] According to an embodiment, the tail end 27 is connected to the fastening element 1 1 .

[0124] Advantageously, the drive screw 25 can thus actuate the translation of the fastening element 1 1 along the tool holder body 2.

[0125] According to an embodiment, the tail end 27 is connected to the bottom wall 24 of the fastening element 11 .

[0126] According to an embodiment, the tail end 27 and the bottom wall 24 are constrained in translation, but not in rotation. By way of example, the tail end 27 and the bottom wall 24 are connectable by means of a pin, or an interlocking element configuredto constrain in translation the tail end 27 and the bottom wall 24, but to allow a relative rotation between the tail end 27 and the bottom wall 24.

[0127] According to an alternative embodiment, the tail end 27 and the bottom wall24 are constrained in translation and in rotation. By way of example, the tail end 27 and the bottom wall 24 are connectable by cold or hot keying so as to prevent both a translation and a relative rotation between the tail end 27 and the bottom wall 24.

[0128] According to an embodiment, the drive screw 25 comprises an outer thread 29.

[0129] The through duct 28 comprises an internally threaded nut portion 30.

[0130] According to this embodiment, the outer thread 29 of the drive screw 25 is meshed with the nut portion 30 of the tool holder body 2.

[0131] Advantageously, a screwing of the outer thread 29 with the nut portion 30 corresponds to a relative translation between the drive screw 25 and the tool holder body 2.

[0132] Accordingly, a screwing of the outer thread 29 with the nut portion 30 corresponds to a relative translation between the fastening element 1 1 , connected to the drive screw 25, and the tool holder body 2.

[0133] According to an embodiment, the outer thread 29 is formed at the head end 26 of the drive screw 25.

[0134] According to an embodiment, the nut portion 30 is formed at an end of the through duct 28 facing the housing seat 8.

[0135] According to an embodiment, the outer thread 29 has an axial extension between 30% and 10% of the axial extension of the entire drive screw 25.

[0136] Preferably, the outer thread 29 has an axial extension between 20% and 15% of the axial extension of the entire drive screw 25.

[0137] According to an embodiment, the nut portion 30 has an axial extension between 30% and 10% of the axial extension of the entire through duct 28.

[0138] Preferably, the nut portion 30 has an axial extension between 20% and 15% of the axial extension of the entire through duct 28.

[0139] According to an embodiment, the drive screw 25 comprises screwing means 31 formed at the head end 26.

[0140] The head screwing means 31 are configured to allow screwing the drive screw25 to the nut portion 30, acting on the head end 26.

[0141] According to an embodiment, the head screwing means 31 consist of a shapedhollow formed in the head end 26, e.g., a hexagonal hollow, extending along the device axis 3.

[0142] Advantageously, the drive screw 25 thus configured is connectable to the fastening element 11 at the tail end 27 of the drive screw 25. The drive screw 25 is thus insertable into the through duct 28, through the rear end 5 of the tool holder body 2, and then screwed to the tool holder body 2, by means of a first screwing of the outer thread 29 to the nut portion 30.

[0143] The insertion and such a first screwing of the drive screw 25 relative to the tool holder body 2 corresponds to a translation of the fastening element 11 relative to the tool holder body 2, for example, to a translation along the first length x1 .

[0144] Preferably, such a first screwing does not result in an elastic deformation, and in particular an expansion or bulging, of the fastening wall 12 of the fastening element 11 . The tool holder device 1 thus assembled is so mountable on a machine tool, in particular is insertable into a mandrel seat of the machine tool.

[0145] After being mounted on the machine tool, for example after the insertion into the mandrel seat, the drive screw 25 is further screwable to the tool holder body 2 by means of the head screwing means 31 .

[0146] Advantageously, the head screwing means 31 are accessible from the housing seat 8, therefore they are accessible also following the mounting of the drive screw 25 in the mandrel seat.

[0147] Such a second further screwing of the outer thread 29 to the nut portion 30 corresponds to a further fastening translation 1 1 relative to the tool holder body 2, for example to a translation along the second length x2.

[0148] Preferably, such a second screwing generates the elastic deformation of the fastening wall 12 of the fastening element 11 , which is in particular an axial elastic compression and a bulging of the fastening wall 12 or a radial expansion of the fastening wall 12.

[0149] After the second screwing, the tool holder device 1 is firmly tightened to the machine tool and positioned concentric with the mandrel seat, thus ensuring highly accurate machining operations.

[0150] Obviously, those skilled in the art will be able to make changes or adaptations to the present invention, without however departing from the scope of the following claims.LIST OF REFERENCE SIGNS1. Tool holder device2. Tool holder body3. Device axis4. Front end5. Rear end6. Housing body7. Insertion body8. Housing seat9. Machining tool10. Outer insertion surface11 . Fastening element12. Fastening wall13. Inner fastening surface14. Fastening seat15. Actuation means16. First end17. Second end18. Outer fastening surface19. Notch20. First notch end21 . Second notch end22. Wall bands23. Contact portion24. Bottom wall25. Drive screw26. Head end27. Tail end28. Through duct29. Outer thread30. Nut portion31 . Head screwing meansL: Total length of the insertion body x: Translation length along the insertion body x1 : First translation length along the insertion bodyx2: Second translation length along the insertion body

Claims

Claims1. A tool holder device (1 ), comprising a tool holder body (2) extending along a device axis (3), between a front end (4) and an opposite rear end (5), wherein the tool holder body (2) comprises a housing body (6), formed at the front end (4), and an opposite insertion body (7), formed at the rear end (5), wherein the housing body (6) is shaped so as to define a housing seat (8) adapted to accommodate a machining tool (9), wherein the insertion body (7) defines an outer insertion surface (10), coaxial to the device axis (3) and facing away from the device axis (3), wherein the outer insertion surface (10) is frustoconical in shape, and wherein the section of the outer insertion surface (10) is reduced towards the rear end (5), wherein the tool holder device (1 ) comprises a fastening element (1 1 ), comprising a fastening wall (12), wherein the fastening wall (12) is coaxial to the device axis (3) and defines an inner fastening surface (13) facing the device axis (3), which defines a fastening seat (14), wherein the fastening wall (12) of the fastening element (1 1 ) is fitted onto the insertion body (7) at the rear end (5), so that the inner fastening surface (13) faces the outer insertion surface (10), and wherein the inner fastening surface (13) has a frustoconical shape consistent with the frustoconical shape of the outer insertion surface (10), and wherein the tool holder device (1 ) comprises actuation means (15), configured to translate the fastening element (1 1 ) relative to the insertion body (7), along the device axis (3).

2. A tool holder device (1 ) according to claim 1 , wherein the fastening element (1 1 ) fitted onto the insertion body (7) is translatable along the device axis (3) towards the front end (4) of the tool holder body (2), so as to generate an interference coupling with the outer insertion surface (10) of the insertion body (7).

3. A tool holder device (1 ) according to claim 1 or 2, wherein the fastening wall (1 1 ) extends between a first end (16) and an opposite second end (17), wherein the first end (16) faces the front end (4) of the tool holder body (2), and the second end (17) is opposite to the front end (4), wherein the fastening wall (12) is configured to be translatable relative to the insertion body (7) over a length (x) of the insertion body (7), measured along the device axis (3),without undergoing a plastic deformation, preferably wherein the length (x) is shorter than the total length (L) of the insertion body (7), and wherein the fastening wall (12) is configured to be translatable relative to the insertion body (7):- over a first length (x1 ) of the insertion body (7), where (x1 ) < (x), without undergoing a substantial elastic deformation;- over a second length (x2) of the insertion body (7), further and subsequent to the first length (x1), undergoing an elastic deformation, and wherein, preferably, the translation of the fastening wall (12) along the second length (x2) is operable by the actuation means (15).

4. A tool holder device (1 ) according to claim 1 or 2, wherein the fastening wall (1 1 ) extends between a first end (16) and an opposite second end (17), wherein the first end (16) faces the front end (4) of the tool holder body (2), and the second end (17) is opposite to the front end (4), wherein the fastening wall (12) is configured to be translatable relative to the insertion body (7) over a length (x) of the insertion body (7), measured along the device axis (3), without undergoing a plastic deformation, preferably wherein the length (x) is shorter than the total length (L) of the insertion body (7), and wherein the fastening wall (12) is configured to be translatable relative to the insertion body (7):- over a first length (x1 ) of the insertion body (7), where (x1 ) < (x), without a reduction in the distance between the first end (16) and the second end (17) of the fastening wall (12), along an axis parallel to the device axis (3),- over a second length (x2) of the insertion body (7), further and subsequent to the first length (x1 ), undergoing an elastic deformation which consists of axial elastic compression and bulging, with reference to the device axis (3), and wherein, preferably, the translation of the fastening wall (12) along the second length (x2) is operable by the actuation means (15).

5. A tool holder device (1 ) according to claim 1 or 2, wherein the fastening wall (1 1 ) extends between a first end (16) and an opposite second end (17), wherein the first end (16) faces the front end (4) of the tool holder body (2), and the second end (17) is opposite to the front end (4), wherein the fastening wall (12) is configured to be translatable relative to the insertionbody (7) over a length (x) of the insertion body (7), measured along the device axis (3), without undergoing a plastic deformation, preferably wherein the length (x) is shorter than the total length (L) of the insertion body (7), and wherein the fastening wall (12) is configured to be translatable relative to the insertion body (7):- over a first length (x1 ) of the insertion body (7), where (x1 ) < (x), without a reduction in the distance between the first end (16) and the second end (17) of the fastening wall (12), along an axis parallel to the device axis (3),- over a second length (x2) of the insertion body (7), further and subsequent to the first length (x1 ), undergoing an elastic deformation which consists of radial expansion, without undergoing an axial elastic compression, with reference to the device axis (3), and wherein, preferably, the translation of the fastening wall (12) along the second length (x2) is operable by the actuation means (15).

6. A tool holder device (1 ) according to any one of claims 3 to 5, wherein (x1 ) + (x2) = (x), and / or wherein (x1 ) is of between 80-90% of (L), or wherein (x1 ) is of between 80-85% of (L), and / or wherein (x2) is of between 10-19% of (L), or wherein (x2) is of between 10-15% of (L), and / or wherein (x1 ) + (x2) is of between 90-99% of (L), or wherein (x1 ) + (x2) is of between 90-95% of (L).

7. A tool holder device (1 ) according to any one of the preceding claims, wherein the fastening wall (12) defines an outer fastening surface (18), opposite to the inner fastening surface (13), wherein the outer fastening surface (18) is cylindrical in shape, and wherein the thickness of the fastening wall (12), in a direction transverse to the device axis (3), increases towards a second end (17) of the fastening wall (12) opposite to the front end (4).

8. A tool holder device (1 ) according to claim 6, wherein the thickness of the fastening wall (12), in a direction transverse to the device axis (3), is minimum at a first end (16) of the fastening wall (12) facing the front end (4), and is maximum at the second end (17) of the fastening wall (12).

9. A tool holder device (1) according to any one of the preceding claims, wherein the fastening wall (12) defines a plurality of notches (19), wherein each notch (19) extends passing through the fastening wall (12) and extends along a direction parallel to the device axis (3), between a first notch end (20) and a second notch end (21), included within the fastening wall (12).

10. A tool holder device (1 ) according to claim 9, wherein each notch (19) forms a linear slot extending between the first notch end (20) and the second notch end (21 ), wherein the notch (19) forms an enlarged notch portion at the second notch end (21 ), preferably being substantially circular in shape, and wherein the first notch ends (20) are positioned at the first end (16) of the fastening wall (12), while the second notch ends (21) are positioned at the first end (17) of the fastening wall (12).

11. A tool holder device (1 ) according to claim 9, wherein each notch (19) forms a linear slot extending between the first notch end (20) and the second notch end (21 ), wherein the notch (19) forms an enlarged notch portion at the second notch end (21 ), preferably being substantially circular in shape, and wherein the notches (19) are positioned in an alternating and inverted manner in a circumferential direction with respect to the device axis (3), so that the first notch ends (20) and the second notch ends (21 ) are positioned in an alternating manner at the first end (16) or at the second end (17).

12. A tool holder device (1) according to any one of the preceding claims, wherein the fastening body (11) comprises a bottom wall (24) connected to the fastening wall (12) at a second end (17) of the fastening wall (12), wherein the bottom wall (24) extends transverse to the device axis (3), coaxial to the device axis (3), wherein the actuation means (15) are connected to the fastening wall (24).

13. A tool holder device (1) according to any one of the preceding claims, wherein the actuation means (15) comprise a drive screw (25) extending along the device axis (3), between a head end (26) and an opposite tail end (27), wherein the head end (26) is positioned at the front end (4) of the tool holder body (2), and the tail end (27) is positioned at the rear end (5) of the tool holder body (2),wherein the tool holder body (2) comprises a through duct (28) extending along the device axis (3) and extending to pass through the tool holder body (2), opening into the housing seat (8) and opening externally onto the rear end (5), and wherein the drive screw (25) is positioned to be inserted into the through duct (28), and wherein the tail end (27) is connected to the fastening element (11 ), preferably to a bottom wall (24) of the fastening element (11), and wherein, optionally, the tail end (27) and the bottom wall (24) are constrained in translation, but not in rotation, or wherein the tail end (27) and the bottom wall (24 ) are constrained in translation and in rotation.

14. A tool holder device (1 ) according to claim 13, wherein the drive screw (25) comprises an outer thread (29), wherein the through duct (28) comprises an internally threaded nut portion (30), wherein the outer thread (29) of the drive screw (25) is meshed with the nut portion (30) of the tool holder body (2), and wherein a screwing of the outer thread (29) with the nut portion (30) corresponds to a relative translation between the fastening element (11 ), connected to the drive screw (25), and the tool holder body (2).

15. A tool holder device (1 ) according to claim 14, wherein the outer thread (29) is formed at the head end (26) of the drive screw (25), and wherein the nut portion (30) is formed at an end of the through duct (28) facing the housing seat (8), and / or wherein the outer thread (29) has an axial extension between 30% and 10% of the axial extension of the entire drive screw (25), preferably between 20% and 15% of the axial extension of the entire drive screw (25), and / or wherein the nut portion (30) has an axial extension between 30% and 10% of the axial extension of the entire through duct (28), preferably between 20% and 15% of the axial extension of the entire through duct (28).

16. A tool holder device (1 ) according to one of claims 13 to 15, wherein the drive screw (25) comprises screwing means (31 ) formed at the head end (26), wherein the head screwing means (31) are configured to allow screwing the drive screw (25) to the nut portion (30), acting on the head end (26), and wherein, optionally, the head screwing means (31 ) consist of a shaped hollow formed in the head end (26), preferably a hexagonal hollow, extending along the device axis (3).

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