Turning cutting tool with adjustable vibration absorber arrangement for suppressing torsional vibrations

Abstract

Turning cutting tool (10), comprising: a tool body (11) comprising a flute section (18) having a plurality of helical flutes (22) separated from each other by teeth (23); and an adjustable vibration absorber arrangement (60) arranged within a cavity (25) formed in the clamping groove section (18), the adjustable vibration absorber arrangement (60) comprising at least two adjustable absorber masses (62), an elastic material (64) between the at least two absorber masses (62) and the cavity (25), and one or more connecting elements (66) arranged between the at least two absorber masses (62) to prevent a relative angular displacement between the at least two adjustable absorber masses (62) about a central longitudinal axis (12) of the rotary cutting tool (10), wherein the one or more connecting elements (66) are not in contact with the tool body (11) to allow the at least two adjustable absorber masses (62) to be held only by the elastic material (64), which enablesthat the adjustable vibration absorber arrangement (60) is set to a desired frequency in order to suppress torsional vibrations of the rotary cutting tool (10) during a cutting operation.

Description

AREA OF INVENTION

[0001] The invention relates in general to a rotatable cutting tool and in particular to a rotary cutting tool, such as a twist drill, a modular drill or the like, with an adjustable vibration absorber arrangement for suppressing torsional vibrations. GENERAL STATE OF THE ART

[0002] During metal machining, any vibration between a cutting tool and a workpiece can lead to undesirable cutting performance, such as poor surface finish and finished parts exceeding tolerances. Furthermore, these vibrations can damage the cutting tool or the machine tool.

[0003] Torsional vibrations in drills with helical flutes can generate axial oscillations due to the spiral shape of the flutes. These oscillations can, in turn, cause variations in chip thickness, leading to chatter. The natural vibrations caused by (axial) torsional vibrations typically occur at high frequencies and produce an undesirable noise level. This problem is particularly critical with large-diameter modular drills and rotary cutting tools with a large length-to-diameter ratio (L / D).

[0004] Turning cutting tools with vibration dampers are known from DE 601 26 277 T2 and US 3 690 414 A.

[0005] Therefore, there is a need to suppress or eliminate torsional vibrations in a rotatable cutting tool. BRIEF SUMMARY OF THE INVENTION

[0006] The problem is solved by a rotary cutting tool having the features of claim 1. The problem is further solved by a rotary cutting tool having the features of claim 10. The problem is further solved by a method for suppressing torsional vibrations in a rotary cutting tool having the features of claim 16.

[0007] The problem of suppressing torsional vibration in a turning tool is solved by providing an adjustable vibration absorber assembly comprising one or more adjustable absorber masses that conform to the shape of the flute teeth in the turning tool. The adjustable absorber masses are held by elastomer or other elastic support elements. The material properties of the support elements, such as stiffness, viscous damping, or the like, are selected such that the torsional frequency of the adjustable masses is set to be similar to the torsional frequency of the drill body. To increase performance, the adjustable masses are rigidly connected to one another. In one embodiment, the number of adjustable masses corresponds to the number of flutes.

[0008] In one aspect, a turning tool comprises a tool body having a flute section with a plurality of helical flutes separated from one another by serrations; and an adjustable vibration absorber assembly located within a cavity formed in the flute section. The adjustable vibration absorber assembly comprises at least two adjustable absorber masses, an elastic material between the at least two absorber masses and the cavity, and one or more connecting elements arranged between the at least two absorber masses to prevent a relative angular displacement between the at least two adjustable absorber masses about the central longitudinal axis of the turning tool.The one or more connecting elements do not come into contact with the tool body, allowing the at least two adjustable absorber masses to be held only by the elastic material, which enables the adjustable vibration absorber arrangement to be set to a desired frequency in order to suppress torsional vibrations of the rotary cutting tool during a cutting operation.

[0009] In a further aspect of the invention, a rotary cutting tool comprises an interchangeable cutting head; a tool body including a seat section for receiving the interchangeable cutting head and a flute section having a plurality of helical flutes separated by teeth; and an adjustable vibration absorber arrangement located within a cavity formed in the interchangeable cutting head. The adjustable vibration absorber arrangement comprises one or more adjustable absorber masses, an elastic material between the one or more absorber masses and the cavity, and one or more connecting elements for preventing a relative angular displacement between the one or more adjustable absorber masses about the central longitudinal axis of the rotary cutting tool.The one or more connecting elements do not come into contact with the interchangeable cutting head, allowing the one or more adjustable absorber masses to be held only by the elastic material, which enables the adjustable vibration absorber assembly to be set to a desired frequency in order to suppress torsional vibrations of the rotary cutting tool during a cutting operation.

[0010] In a further aspect, a method for suppressing torsional vibrations in a rotary cutting tool comprises arranging an adjustable vibration absorber assembly within a cavity formed in the rotary cutting tool, wherein the adjustable vibration absorber assembly comprises at least two adjustable absorber masses, an elastic material between the at least two absorber masses and the cavity, and one or more connecting elements arranged between the at least two absorber masses to prevent a relative angular displacement between the at least two adjustable absorber masses about the central longitudinal axis of the rotary cutting tool, and adjusting the adjustable vibration absorber assembly to a desired frequency by selecting one or more material properties of the at least two adjustable absorber masses, the elastic material, and the one or more connecting elements.which suppresses the torsional vibrations of the rotary cutting tool during a cutting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] While various embodiments of the invention are illustrated, the specific embodiments shown should not be interpreted as limiting the claims. It is anticipated that various changes and modifications can be made without departing from the scope of this invention. Fig. Figure 1 is a perspective view of a rotary cutting tool, such as a modular drill, with an internal adjustable vibration absorber arrangement, according to an embodiment of the invention; Fig. Figure 2 is an enlarged cross-sectional view of the modular drill along line 2-2 of Fig. 1, which shows the adjustable vibration absorber arrangement according to the invention with adjustable absorber masses having a fan-shaped cross-section and arranged within the teeth of the modular drill; Fig. Figure 3 is a graphical representation of a simulated frequency response function illustrating the tangential displacement (in the Y direction) of a modular drill set according to the invention and of a modular drill without the adjustable vibration absorber arrangement according to the invention, which was measured on an outer surface of the modular drill; Fig. Figure 4 is a graphical representation of a simulated frequency response function illustrating the radial displacement (in the Y direction) of a modular drill set according to the invention and of a modular drill without the adjustable vibration absorber arrangement according to the invention, which was measured at a center point of the modular drill. Fig. Figure 5 is a graphical representation of a simulated frequency response function illustrating the axial displacement (in the Z direction) of a modular drill set according to the invention and of a modular drill without the adjustable vibration absorber arrangement according to the invention, which was measured at the center of the tip of the modular drill; Fig. Figure 6 is a graphical representation of a simulated frequency response function illustrating the axial displacement (in the Z direction) of a modular drill set according to the invention and of a modular drill without the adjustable vibration absorber arrangement according to the invention, which was measured on an outer surface of the modular drill. Fig. Figure 7 is an enlarged cross-sectional view of the modular drill along line 2-2 of Fig. 1, which shows the vibration absorber arrangement according to the invention with adjustable absorber masses having a circular cross-section and arranged within the teeth of the modular drill; Fig. Figure 8 is a perspective view of a rotary cutting tool, such as a modular drill, with an internal adjustable vibration absorber arrangement arranged within an interchangeable cutting head, according to an embodiment of the invention; Fig. Figure 9 is an enlarged view of the interchangeable cutting head of the modular drill from Fig. 8 with an adjustable vibration absorber arrangement arranged within the replaceable cutting head according to an embodiment of the invention; Fig. Figure 10 is a side view of the interchangeable cutting head of Fig. 8 with the adjustable vibration absorber arrangement arranged within the replaceable cutting head according to an embodiment of the invention; Fig. Figure 11 is a cross-sectional view of the interchangeable cutting head with the adjustable vibration absorber arrangement located within the interchangeable cutting head along line 11-11 of Fig. 10; Fig. Figure 12 is a top view of the interchangeable cutting head of Fig. 8 with the adjustable vibration absorber arrangement located within the interchangeable cutting head; and Fig. Figure 13 is a cross-sectional view of the interchangeable cutting head of Fig. 8 with the adjustable vibration absorber arrangement located within the interchangeable cutting head along line 13-13 of Fig. 12. DETAILED DESCRIPTION OF THE INVENTION

[0012] The description of specific applications herein should not be a limitation on the scope and extent of the use of the cutting tool.

[0013] The directional terms used herein, such as left, right, front, back, top, bottom, and derivatives thereof, refer to the orientation of the elements shown in the drawings and do not limit the claims unless expressly stated herein. Identical parts are identified by the same reference number in all drawings.

[0014] The approximation language used throughout this description and the claims may be applied to modify any quantitative representation that could permissibly vary without resulting in a change to the fundamental function to which it relates. Accordingly, a value modified by a term or terms such as "about," "approximately," and "essentially" is not intended to be limited to the exact value stated. At least in some cases, the approximation language may correspond to the precision of an instrument for measuring the value. Here, and throughout this patent and the claims, range boundaries may be combined and / or interchanged, and such ranges are identified and include all subranges contained therein unless context or language indicates otherwise.

[0015] Throughout the text and claims, the use of the word "approximately" in relation to a range of values ​​(e.g., "approximately 22 to 35 wt.%) is intended to modify both the specified high and low values ​​and reflects the penumbra of variation associated with measurement, significant places, and interchangeability, all as understood by an average person skilled in the art to whom this invention relates.

[0016] For the purposes of this patent specification (except in the operational examples), unless otherwise stated, all numbers expressing quantities and ranges of components, process conditions, etc., are to be understood in all cases as modified by the term "approximately". Accordingly, the numerical parameters specified in this specification and the appended claims are approximations that may vary depending on the desired results to be obtained with the present invention. At the very least, and not as an attempt to limit the application of the equivalence doctrine to the scope of the claims, each numerical parameter should be interpreted at least in view of the number of significant figures indicated and by applying ordinary rounding techniques.As used in this specification and the attached claims, the singular forms “ein”, “eine” and “der / die / das” shall furthermore include the plural forms unless they are expressly and unambiguously limited to one form.

[0017] Notwithstanding the fact that the numerical ranges and parameters that define the broad scope of the invention are approximations, the numerical values ​​presented in the specific examples are reported as precisely as possible. However, every numerical value inherently contains certain errors that inevitably arise from the standard deviation found in the respective corresponding test measurements, including those found in the measuring instrument. It is also understood that each numerical range listed herein is intended to encompass all subranges summarized therein. For example, a range of "1 to 10" is intended to encompass all subranges in between, including the listed minimum value of 1 and the listed maximum value of 10; that is, a range with a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.Since the disclosed numerical ranges are continuous, they encompass every value between the minimum and maximum values. Unless explicitly stated otherwise, the various numerical ranges specified in this application are approximations.

[0018] In the following patent specification and claims, reference is made to a number of terms which have the following meanings.

[0019] The singular forms “ein”, “eine” and “der / die / das” include the plural unless the context clearly dictates otherwise.

[0020] “Optional” means that the event or circumstance described below may or may not occur, and that the description includes examples where the event occurs and examples where it does not.

[0021] The term "helical," as used herein, is defined as relating to or having the shape of a helix or spiral. A "helix" or "spiral" is defined as a curve in three-dimensional space formed by a straight line drawn on a plane, when that plane is enveloped around a cylindrical surface of any kind, and in particular a right circular cylinder, as the curve of a screw. A circular spiral with radius a and a pitch b / a (or division 2πb) is described by the following parameterization: x(θ)=a sinθ, y(θ)=a cosθ, z(θ)=bθ.

[0022] The term "angle of helix," as used herein, is defined as the angle between any helix and an axial line on its right circular cylinder or cone. The angle of helix is ​​relative to the axis of the cylinder and differs from the angle of helix, which is relative to a line perpendicular to the axis. The angle of helix is ​​therefore the geometric complement of the angle of helix. The angle of helix is ​​measured in degrees.

[0023] As used here, the helix of a groove can rotate in two possible directions, a phenomenon known as handedness. Most grooves are oriented such that, when rotated clockwise, the cutting tool moves away from the viewer from a point on the axis through the center of the helix, and toward the viewer when rotated counterclockwise. This is known as right-handed (RH) groove geometry because it follows the right-hand grip rule. Grooves oriented in the opposite direction are referred to as left-handed (LH).

[0024] The term “3D printing,” as used herein, refers to one of several processes in which material is assembled or solidified under computer control to create a three-dimensional object, typically by fusing materials such as liquid molecules or powdered grains together, layer by layer. In the 1990s, 3D printing techniques were considered suitable only for producing functional or aesthetic prototypes, and at that time, rapid prototyping was a broader term for 3D printing. Today, precision, repeatability, and the range of materials available have improved to such an extent that 3D printing is considered an industrial production technology, officially termed “additive manufacturing.”

[0025] The term “torsional vibration”, as used herein, is the angular vibration of an object, such as the shaft of a rotatable cutting tool, along its axis of rotation.

[0026] The term “axial vibration”, as used herein, is the vibration of an object, such as the shaft of a rotatable cutting tool, along its axis of rotation.

[0027] Fig. Figure 1 shows a rotary cutting tool 10 for performing cutting operations on a workpiece (not shown) when the rotary cutting tool 10 is rotated about a central longitudinal axis 12 according to an exemplary embodiment of the invention. Although a modular drill is shown in the embodiment described here, it is understood that the principles of the invention described herein are also applicable to other rotary cutting tools, such as, without limitation, a solid carbide drill, a milling tool, a reamer, a tap, an end mill, or the like.

[0028] The turning tool 10 is generally cylindrical and comprises a first or front end 14 and an opposing second or rear end 16. The turning tool 10 has a tool body 11 that includes a seat section 17 near the first end 14 for securely receiving a replaceable cutting insert 50 and a flute section 18 with one or more internal adjustable absorber masses, as described in more detail below. The tool body 11 may be made of tool steel, carbide, or another suitable material. The replaceable cutting insert 50 may, for example, be made of solid carbide or another suitable material. The tool body 11 also includes a mounting section 20 near the second end 16 for securing the turning tool 10 in a chuck mechanism of a machine tool (not shown).

[0029] The flute section 18 further comprises several helical flutes 22 separated by teeth 23, extending from the first end 14 of the flute section 18 rearward to the mounting section 20. Each flute 22 allows chips formed by the turning tool 10 to exit the flute section 18 during a cutting operation. Each flute 22 has a helical geometry or pattern and is arranged with a helix angle 24 relative to the central longitudinal axis 12. In one embodiment, the helix angle 24 is approximately 30 degrees (+ / - 2 degrees). However, it is understood that the invention is not limited by the size of the helix angle 24 and that the invention can be implemented with any desired helix angle 24 in a range between approximately greater than 0° and approximately 75°.

[0030] In the illustrated embodiment, the rotary cutting tool 10 includes two grooves 22 (in Fig. (1 shows only one groove 22) and two teeth 23. However, it is understood that the invention is not limited by the number of grooves 22 and teeth 23, and that the invention can be practiced with a rotary cutting tool having any desirable number of grooves 22 and teeth 23, such as three, four, five, six, seven, eight or the like.

[0031] Fig. Figure 2 is a cross-sectional view of the flute section 18 of the cutting tool 10 from a plane orthogonal to a plane running along the central longitudinal axis 12. The use of the turning and cutting tool 10 in a metalworking operation generates vibrations that propagate through the cutting tool 10 and thereby affect the stability of the cutting process. For this reason, the flute section 18 of the turning and cutting tool 10 incorporates an adjustable vibration damper arrangement, generally shown at 60°, to suppress torsional and axial vibrations of the cutting tool. Fig. 2 illustrated rotary cutting tool 10.

[0032] In general, the adjustable vibration absorber assembly 60 is arranged within a cavity 25 in each tooth 23 of the flute section 18 and has a length L along the central longitudinal axis 12 of the cutting tool 10. The adjustable vibration absorber assembly 60 comprises one or more adjustable absorber masses 62, an elastic material 64 arranged between the respective adjustable absorber masses 62 and the cavity 25, and one or more connecting elements 66 for rigidly fastening the respective absorber masses 62 to one another. The adjustable vibration absorber assembly 60 has a front end 63 and a rear end 65. In the illustrated embodiment, the modular drill 10 has two grooves 22 and teeth 23.Thus, the adjustable vibration absorber arrangement 60 has two adjustable absorber masses 62, wherein one adjustable absorber mass 62 follows the twisted, helical path of one tooth 23 and another adjustable absorber mass 62 follows the twisted, helical path of the other tooth 23.

[0033] It should be noted that the one or more connecting elements 66 are not in contact with the tool body 11, thus allowing the absorber masses 62 to be held or supported only by the elastic element 64. This allows the absorber arrangement 60 to be tuned to the desired frequency, such as the first natural frequency of a torsional vibration mode of the cutting tool 10, by selecting one or more material properties of the adjustable vibration absorber arrangement 60. It should be noted that the adjustable vibration absorber arrangement 60 can be manufactured using a 3D printing process (i.e., by additive manufacturing).

[0034] The material for the absorber masses 62 is selected with regard to its material properties, such as stiffness, density, or the like. In one embodiment, the absorber masses 62 are made of the same material as the tool body 11. For example, the absorber masses 62 can be made of tool steel, cemented carbide, or the like. In another embodiment, the absorber masses 62 can be made of a different material than the tool body 11. Typically, the absorber masses 62 are made of a material having a density greater than or equal to that of the tool body 11. For example, the absorber masses 62 can be made of lead, heavy metal, bronze, or the like, and the tool body 11 can be made of tool steel, cemented carbide, or the like.

[0035] Similar to the absorber masses 62, the elastic element 64 is selected with respect to its material properties, such as stiffness, viscous damping, density, and the like. In one embodiment, the elastic element 64 is made of a viscoelastic polymer (i.e., exhibiting both viscosity and elasticity) with a generally low modulus of elasticity and high failure stress compared to other materials. In another embodiment, the elastic element 64 can be made of a commercially available fluoropolymer elastomer marketed under the trade name VITON®, a registered trademark of The Chemours Company, located in Wilmington, Delaware.

[0036] Similar to the adjustable absorber masses 62 and the elastic element 64, the one or more connecting elements 66 are selected with respect to their material properties, such as stiffness, density, or the like. For example, the material of the one or more connecting elements 66 has sufficient stiffness to prevent a relative angular displacement between the one or more adjustable absorber masses 62 about the central longitudinal axis 12 of the cutting tool 10. In the illustrated embodiment, the adjustable vibration absorber assembly 60 includes two connecting elements 66, one connecting element 66 near the front end 63 and the other connecting element 66 near the rear end 65 of the adjustable vibration absorber assembly 60.The connecting elements 66 can have any desirable cross-sectional shape, such as circular, polygonal, or the like, as long as the connecting element 66 prevents a relative angular displacement between the absorber masses 62 about the central longitudinal axis 12 of the cutting tool 10. The invention can be implemented without the connecting elements 66. However, it has been shown that preventing the relative angular movement between the absorber masses 62 with respect to the central longitudinal axis 12 of the cutting tool 10 improves the adjustability of the vibration absorber arrangement 60, since the connecting elements 66 limit the size of the swivel range of the adjustable absorber masses 62. Furthermore, it has been shown that connecting the masses allows each of the absorber masses 62 to vibrate at the same frequency and to act as one large mass, rather than several independent masses, thus increasing the damping effect on the drill.

[0037] As in Fig. As shown in Figure 2, the cross-sectional shape of the cavity 25 is not circular. Specifically, the cavity 25 has a geometry that maximizes the cross-sectional area of ​​the absorber masses 62 without significantly affecting the overall stiffness of the cutting tool 10. In the illustrated embodiment, the cavity 25 has a fan-shaped cross-section defined by a flat front wall 25a, which extends radially along the front side of the cutting tool 10 in a direction of rotation RD. The cavity 25 also includes a flat rear wall 25b, which extends radially along the rear side of the cutting tool 10 in a direction of rotation RD and circumferentially around the cutting tool 10 relative to the flat front wall 25a. The flat front wall 25a and the flat back wall 25b form an angle A. The angle A can lie in a range between approximately 15° and approximately 40°.The cavity 25 also has a radially outer curved wall 25c, which consists of a partially cylindrical surface whose center point lies on a central longitudinal axis 12 of the cutting tool 10, and a radially inner curved wall 25d, which consists of a partially cylindrical surface whose center point lies on the central longitudinal axis 12 of the cutting tool.

[0038] Fig. Figure 3 is a graphical representation of a simulated frequency response function measured on an outer surface of the modular drill, illustrating the displacement in the tangential direction (in the Y-direction) of a modular drill according to the invention with the adjustable vibration absorber arrangement 60 according to the invention and of the same modular drill without the adjustable vibration absorber arrangement according to the invention. As shown in Fig. As shown in Figure 3, the displacement in the tangential direction (i.e., Y-direction) on the outer surface of the modular drill was reduced by a factor of about thirteen (13) at a frequency of about 4100 Hz using the adjustable vibration absorber arrangement 60 according to the invention.

[0039] Fig. Figure 4 is a graphical representation of a simulated frequency response function measured at a midpoint (i.e., at the central longitudinal axis 12) of the drill, illustrating the radial (Y-direction) displacement of a modular drill according to the invention with the adjustable vibration absorber arrangement 60 according to the invention and of the same modular drill without the adjustable vibration absorber arrangement according to the invention. As shown in Fig. As shown in Figure 4, the radial displacement at a bending frequency of approximately 3200 Hz on the central longitudinal axis 12 of a modular drill was reduced by a factor of more than 4.5 using the adjustable vibration absorber arrangement 60 according to the invention.

[0040] Fig. Figure 5 is a graphical representation of a simulated frequency response function measured at the center of the cutting tip of the modular drill, illustrating the axial displacement (in the Z-direction) of a modular drill according to the invention with the adjustable vibration absorber arrangement 60 according to the invention and of the same modular drill without the adjustable vibration absorber arrangement according to the invention. As shown in Fig. As shown in Figure 5, the axial displacement (i.e., the displacement in the Z-direction) was reduced by a factor of about eight (8) at a frequency of about 4100 Hz using the adjustable vibration absorber arrangement 60 according to the invention. It is known that the axial and angular displacements are related due to the helical shape of the clamping grooves. The reduction in the amplitude of the angular displacement due to the damping of the torsional mode by the adjustable vibration absorber arrangement ( Fig. 3) also causes a reduction in the amplitude of the axial displacement.

[0041] Fig. Figure 6 is a graphical representation of a simulated frequency response function measured on an outer surface of the modular drill, illustrating the axial displacement (in the Z-direction) of a modular drill according to the invention with the adjustable vibration absorber arrangement 60 according to the invention and of the same modular drill without the adjustable vibration absorber arrangement according to the invention. As shown in Fig. As shown in Figure 6, the axial displacement (i.e., Z-direction) of the modular drill was reduced by a factor of about eight (8) at a frequency of about 4100 Hz using the adjustable vibration absorber arrangement 60 according to the invention.

[0042] In summary, the rotary cutting tool 10, such as a modular drill, which includes the adjustable vibration absorber arrangement 60 according to the invention, has yielded the unexpected result of significantly reducing the tangential, axial and radial displacement of the modular drill compared to the same modular drill without the adjustable vibration absorber arrangement 60 according to the invention.

[0043] As mentioned above, the absorber masses 62 and the elastic element 64 have a non-circular cross-sectional shape that adapts to the shape of the cavity 25. However, it is understood that the invention is not limited to the cross-sectional shape of the absorber masses 62 and the elastic element 64 and that the invention can be implemented with absorber masses and elastic elements of any desirable cross-sectional shape.

[0044] Fig. Figure 7 shows an adjustable vibration absorber arrangement 70 according to a further aspect of the invention. In this aspect, the adjustable vibration absorber arrangement 70 has a substantially circular cross-sectional shape instead of a fan-shaped cross-sectional shape of the adjustable vibration absorber arrangement 60. Thus, the cavity 25 has a substantially circular cross-sectional shape. Furthermore, the connecting elements 76 also have a substantially circular cross-sectional shape, in contrast to the connecting elements 66, which have a substantially non-circular cross-sectional shape. In the illustrated embodiment, the adjustable vibration absorber arrangement 70 has two connecting elements 76, one connecting element 76 near the front end 73 and the other connecting element 76 near the rear end 75 of the adjustable vibration absorber arrangement 70.Similar to the connecting elements 66, the connecting elements 76 are not in contact with the tool body 11, which allows the absorber masses 72 to be held or supported only by the elastomer element 74.

[0045] As described above, the vibration absorber arrangement 60, 70 is arranged within the flute section 18 of the modular drill 10. Specifically, the adjustable absorber masses 62, 72 are arranged within the respective teeth 23 of the modular drill 10. It is understood, however, that the invention is not limited to the location of the adjustable vibration absorber arrangement 60, 70 within the flute section 18 of the modular drill 10 and that the invention can be implemented with the adjustable vibration absorber arrangement 60, 70 at any desirable location.

[0046] In Fig. Figures 8-13 show a modular cutting tool 100 according to a further embodiment of the invention. In the illustrated embodiment, the modular cutting tool 100 has an interchangeable cutting head 150 with an adjustable vibration absorber arrangement 80 arranged therein. The adjustable vibration absorber arrangement 80 is essentially similar in design to the adjustable vibration absorber 60, wherein the absorber masses have a fan-shaped cross-section, as shown in Figure 8-13. Fig. 2 shown. However, it should be noted that the adjustable vibration absorber arrangement 80 can be designed similarly to the adjustable vibration absorber arrangement 70, wherein the adjustable absorber masses 82 have a substantially circular cross-section, as shown in Fig. 7 shown.

[0047] In general, the adjustable vibration absorber assembly 80 is arranged within a cavity 125 in the replaceable cutting head 150 and has a length L along the central longitudinal axis 12 of the modular drill 100. Similar to the adjustable vibration absorber assemblies 60, 70, the adjustable vibration absorber assembly 80 comprises one or more adjustable absorber masses 82, an elastic material 84 arranged between the respective adjustable absorber masses 82 and the cavity 125, and one or more connecting elements 86 for rigidly fastening the respective absorber masses 82 to one another. In the illustrated embodiment, the modular drill 100 has two flutes 22 and teeth 23.Thus, the adjustable vibration absorber arrangement 80 has two adjustable absorber masses 82, wherein one adjustable absorber mass 82 follows the twisted, helical path of one tooth 23 and another adjustable absorber mass 82 follows the twisted, helical path of the other tooth 23.

[0048] It should be noted that the one or more connecting elements 86 are not in contact with the cutting head body 11, thus allowing the absorber masses 82 to be held or supported only by the elastic element 84. This allows the absorber assembly 80 to be tuned to the desired frequency, such as the first natural frequency of the torsional vibration mode of the cutting tool 100, by selecting one or more material properties of the adjustable vibration absorber assembly 80. It should be noted that the adjustable vibration absorber assembly 80 can be manufactured using a 3D printing process (i.e., by additive manufacturing). It is assumed that placing the absorber masses 82 closer to the cutting edges of the interchangeable cutting head 150 improves the effectiveness of the adjustable vibration absorber assembly 80.

[0049] Although the rotary cutting tool 10 comprises a modular drill, it is understood that the principles of the invention can be practiced with a solid drill, such as a solid carbide drill, in which the adjustable absorber masses are located in the teeth of the solid carbide drill, similar to the design described in Fig. 2 adjustable vibration absorber arrangement shown 60.

[0050] While the currently preferred embodiments are described, the invention may be embodied in other ways within the scope of the attached claims.

Claims

[1] Rotary cutting tool (10), comprising: a tool body (11) comprising a flute section (18) having a plurality of helical flutes (22) separated from each other by teeth (23); and an adjustable vibration absorber arrangement (60) arranged within a cavity (25) formed in the clamping groove section (18), the adjustable vibration absorber arrangement (60) comprising at least two adjustable absorber masses (62), an elastic material (64) between the at least two absorber masses (62) and the cavity (25), and one or more connecting elements (66) arranged between the at least two absorber masses (62) to prevent a relative angular displacement between the at least two adjustable absorber masses (62) about a central longitudinal axis (12) of the rotary cutting tool (10), wherein the one or more connecting elements (66) are not in contact with the tool body (11) to allow the at least two adjustable absorber masses (62) to be held only by the elastic material (64), which enablesthat the adjustable vibration absorber arrangement (60) is set to a desired frequency in order to suppress torsional vibrations of the rotary cutting tool (10) during a cutting operation. [2] Rotary cutting tool (10) according to claim 1, wherein the at least two adjustable absorber masses (62) have a fan-shaped cross-section. [3] Rotary cutting tool (10) according to claim 1 or 2, wherein the at least two adjustable absorber masses (62) have a circular cross-section. [4] Rotary cutting tool (10) according to one of the preceding claims, wherein the at least two adjustable absorber masses (62) are arranged within all teeth (23) of the flute section (18). [5] Rotary cutting tool (10) according to one of the preceding claims, wherein the at least two adjustable absorber masses (62) are made of a material having a density greater than or equal to that of the tool body (11). [6] Rotary cutting tool (10) according to one of the preceding claims, wherein the desired frequency corresponds to a first natural frequency of a torsional vibration mode of the rotary cutting tool (10). [7] Rotary cutting tool (10) according to one of the preceding claims, wherein the adjustable vibration absorber arrangement (60) is formed by additive manufacturing. [8] Rotary cutting tool (10) according to one of the preceding claims, wherein the rotary cutting tool (10) comprises a modular drill having an interchangeable cutting head (150) and a seat section (17) for receiving the interchangeable cutting head (150). [9] Rotary cutting tool (10) according to one of the preceding claims, wherein the rotary cutting tool (10) comprises a modular drill comprising a replaceable cutting insert (50) and a seat section (17) for receiving the replaceable cutting insert (50). [10] Rotary cutting tool (100), comprising: an interchangeable cutting head (150); a tool body (11) with a seat section (17) for receiving the replaceable cutting head (150); and an adjustable vibration absorber arrangement (80) arranged within a cavity (125) formed in the interchangeable cutting head (150), the adjustable vibration absorber arrangement (80) comprising one or more adjustable absorber masses (82), an elastic material (84) between the one or more absorber masses (82) and the cavity (125), and one or more connecting elements (86) for preventing a relative angular displacement between the one or more adjustable absorber masses (82) about the central longitudinal axis (12) of the rotary cutting tool (100), wherein the one or more connecting elements (86) are not in contact with the interchangeable cutting head (150) in order to allow the one or more adjustable absorber masses (82) to be held only by the elastic material (84), which enablesthat the adjustable vibration absorber arrangement (80) is set to a desired frequency in order to suppress torsional vibrations of the rotary cutting tool (100) during a cutting operation. [11] Rotary cutting tool (100) according to claim 10, wherein the one or more adjustable absorber masses (82) have a fan-shaped cross-section. [12] Rotary cutting tool (100) according to claim 10 or 11, wherein the one or more adjustable absorber masses (82) have a circular cross-section. [13] Rotary cutting tool (100) according to one of claims 10 to 12, wherein the one or more adjustable absorber masses (82) are made of a material having a density greater than or equal to that of the tool body (11). [14] Rotary cutting tool (100) according to one of claims 10 to 13, wherein the desired frequency corresponds to a first natural frequency of a torsional vibration mode of the rotary cutting tool (100). [15] Rotary cutting tool (100) according to one of claims 10 to 14, wherein the adjustable vibration absorber arrangement (80) is formed by additive manufacturing. [16] Method for suppressing torsional vibrations in a rotary cutting tool (10, 100), comprising: Arranging an adjustable vibration absorber arrangement (60, 80) within a cavity (25, 125) formed in the rotary cutting tool (10, 100), wherein the adjustable vibration absorber arrangement (60, 80) comprises at least two adjustable absorber masses (62, 82), an elastic material (64, 84) between the at least two absorber masses (62, 82) and the cavity (25, 125), and one or more connecting elements (66, 86) arranged between the at least two absorber masses (62, 82) to prevent a relative angular displacement between the at least two adjustable absorber masses (62, 82) about a central longitudinal axis (12) of the rotary cutting tool (10, 100); and Adjusting the adjustable vibration absorber arrangement (60, 80) to a desired frequency by selecting one or more material properties of the at least two adjustable absorber masses (62, 82), the elastic material (64, 84) and the one or more connecting elements (66, 86), which suppresses the torsional vibrations of the rotary cutting tool (10, 100) during a cutting operation. [17] Method according to claim 16, wherein the desired frequency corresponds to a first natural frequency of a torsional vibration mode of the rotary cutting tool (10, 100). [18] Method according to claim 16 or 17, wherein the adjustable vibration absorber arrangement (60, 80) is formed by additive manufacturing. [19] Method according to any one of claims 16 to 18, wherein the rotary cutting tool (100) comprises a modular drill having an interchangeable cutting head (150) and a seat section (17) for receiving the interchangeable cutting head (150) and wherein the adjustable vibration absorber arrangement (80) is arranged within the interchangeable cutting head (150).

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