Tool chuck

Abstract

To provide a tool chuck.SOLUTION: There is provided a tool chuck which is used for clamping tools having a tool shank. The tool chuck comprises a sleeve section which is open at a free end of the tool chuck and connected to a tool chuck main body while oriented towards the free end. The sleeve section forms a tool holding section for friction-locking the tool shank in press fitting. The sleeve section is formed of an inner sleeve and an outer sleeve. The outer sleeve, in an operation state, holds the inner sleeve and is joined to the inner sleeve without clearance. The tool chuck is characterized in that there is an expansion gap between the tool chuck main body, the inner sleeve and the outer sleeve, or at least one first intermediate sleeve is disposed between the inner and outer sleeves, or a functional face of at least one of parts joined to one another at the sleeve section is thermochemically heat-treated and / or coated.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] The present invention relates to a tool chuck according to the preambles of the independent claims, to a special use of the tool chuck according to the preambles of the respective corresponding independent claims, and to a chuck system formed therewith. [Background technology]

[0002] Background technology Chucks in the form of shrink-fit chucks have proven to be very effective in practice, since they provide very high holding forces with little effort. Moreover, they offer the possibility to hold the fitted tool with high bending stiffness, so that the holding is performed precisely and also produces high-precision geometries on the workpiece during the machining process. However, at the same time, they often clamp the tool shank very strongly or rigidly, which makes vibration problems more important.

[0003] The quality of the shank tool clamping is very important to the quality of machining achieved by the tool and in many cases also to the tool life.

[0004] This is even more true in high speed metal cutting processes, especially where the cutting speed is greater than 800 meters per minute or even greater than 1,100 meters per minute.

[0005] The quality of the clamping also depends on how well any vibrations that may occur can be damped. One of the main causes of such vibrations can be, for example, a rapid change in the number of teeth of the milling cutter that are actually in contact with the workpiece, which can result in, for example, significant harmful bending vibrations.

[0006] A different, but equally detrimental, vibration can result from the tendency of shank tools, especially end mills, to flex during operation. Deflection refers to the slight elastic deformation of the shank that is repeated with each revolution and varies locally during revolution due to contact with the workpiece under the feed load.

[0007] The document DE 10 05 04 053 A1, which is known from the prior art, takes these requirements into account. DE 10 05 04 053 A1, in so doing, provides a tool chuck for clamping a tool with a tool shank, which has a sleeve part which is open at its free end and which preferably consists of an electrically conductive material, which sleeve part forms a tool holding part for friction locking of the tool shank in a press-fit by shrinkage. In so doing, the sleeve part is preferably composed, at least over the entire axial length of the tool holding part, of an inner sleeve and an outer sleeve, which holds the inner sleeve in the operating state and joins with it without play and which is preferably also made of an electrically conductive material. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent Application Publication No. 102021119935A1 [Patent Document 2] German Patent Application Publication No. 19915412A1 Summary of the Invention [Problem to be solved by the invention]

[0009] assignment The object of the invention is to improve upon the known chucks and to provide a tool chuck which is capable of applying particularly high clamping forces and which is better able to handle the concomitant vibrations. [Means for solving the problem]

[0010] solution This problem is solved by a tool chuck, a use of a tool chuck and a tool clamping system having the features of the respective independent claims.

[0011] Advantageous further developments of the invention are the subject of the dependent claims and the following description and also relate to a tool chuck, a use and a tool clamping system.

[0012] Terms used as the case may be, such as above, below, front, back, left or right, shall be interpreted according to common usage having regard to the drawings, unless expressly defined otherwise. Terms such as radial and axial, shall be interpreted with reference to the drawings, in relation to a central axis or axis of symmetry of a part / component, unless expressly defined otherwise.

[0013] When the term "essentially" is used, it can be understood to mean "to a substantially significant extent" (as understood by the Supreme Court). Possible deviations from the exact value that this term refers to may arise unintentionally (i.e., without functional reason) due to manufacturing or assembly tolerances or the like.

[0014] The tool chuck is for clamping a tool having a tool shank, such as a milling or drilling tool, and is open at a free end of the tool chuck and comprises a sleeve portion towards the free end which is connected to the tool chuck base.

[0015] The sleeve part forms a tool holding part for friction locking of the tool shank by press fitting, in particular by shrink fitting. The sleeve part can preferably consist of an electrically conductive material.

[0016] The sleeve part, preferably over the entire axial length of the tool holder, consists of an inner sleeve and an outer sleeve, the outer sleeve holding the inner sleeve in the operating state and joining it without play.

[0017] The outer sleeve may also preferably be made of a conductive material.

[0018] The tool chuck features an extending gap between a tool chuck base, an inner sleeve, and an outer sleeve.

[0019] In this case, an "extension gap" is understood to be the (narrow) free space between two or more components, in this case between the tool chuck base, the inner sleeve and the outer sleeve.

[0020] Such expansion gaps are preferably used where parts made from different materials and / or having different properties (eg, susceptibility to thermal contraction and expansion) come into contact (joints).

[0021] Where the term "expansion gap" has a functional meaning of relieving stress and preventing cracks in addition to its physical meaning as a gap, the expansion gap provided in the tool chuck may alternatively be called or considered as an undercut.

[0022] The term "undercut" in this case also has a manufacturing-related meaning and may be a cutout with a specific shape and certain dimensions on the surface of a part, in this case the tool chuck base, the inner sleeve and the outer sleeve, which forms a free space there (see extension gap), which is particularly visible / formed when the parts, in this case the tool chuck base, the inner sleeve and the outer sleeve, are joined to one another.

[0023] Briefly and clearly, the tool chuck is characterized by the fact that at the junctions between the tool chuck base, the inner sleeve, and the outer sleeve, the tool chuck base, the inner sleeve, and the outer sleeve are provided with free spaces, i.e., extension gaps or undercuts, which are more appropriately and simply formed by material removal or "missing material" (if the inner sleeve is integral with the tool chuck base, the free spaces are formed accordingly, see below).

[0024] The expansion gaps or undercuts in the tool chuck, in this case between the tool chuck base, the inner sleeve and the outer sleeve, make it possible to relieve stresses and prevent cracks at the joints between the tool chuck base, the inner sleeve and the outer sleeve, in particular, which makes it possible to extend or improve the service life and / or the quality of the tool chuck (in particular all its properties such as damping).

[0025] Advantageously, a groove forming a free space in the extension gap or undercut is formed in the tool chuck base.

[0026] The tool chuck may also feature at least a first intermediate sleeve between the inner sleeve and the outer sleeve.

[0027] By means of at least one first intermediate sleeve between the inner sleeve and the outer sleeve, the tool chuck can be made to have a significantly reduced tendency to harmful vibrations, i.e. the damping / vibration behavior of the tool chuck is also improved.

[0028] This appears to be due to the boundary layer where the intermediate sleeve contacts the inner or outer sleeve in the area of ​​the tool holder, which causes damping or a loss of vibration transmission, especially in the case of metal-to-metal contact.

[0029] This seems to apply in particular when the intermediate sleeve, the inner sleeve and the outer sleeve are in inseparable contact with one another in normal operation, for example when they are pressed against one another, in particular because they are already pressed against one another before the clamping of the tool shank and the associated expansion limitation, and because their pressing is further increased by the clamping of the tool shank.

[0030] In other words, it is particularly useful if the at least one first intermediate sleeve has an interference fit with the inner sleeve and / or the outer sleeve.

[0031] The tool chuck may further be characterized in that the functional surface of at least one of the components joined to one another in the sleeve portion is thermochemically heat treated and / or coated, in particular at the inner circumferential surface of the outer sleeve or at the outer circumferential surface of the inner sleeve or at least at the inner and / or outer circumferential surface of at least a first intermediate sleeve arranged between the inner and outer sleeves.

[0032] The coating, and in particular the thermochemical heat treatment, provides the tool chuck with increased surface hardness on its functional surfaces, which makes them more resistant to abrasive wear, adhesiveness and corrosive wear.

[0033] Thermochemical heat treatments are particularly useful if they are nitriding by diffusion of nitrogen, such as, for example, plasma nitriding, vacuum nitriding, or gas nitriding, or nitriding by diffusion of nitrogen and carbon, such as, for example, gas nitrocarburizing, plasma nitrocarburizing, salt bath nitrocarburizing.

[0034] Therefore, in the plasma nitriding and soft nitriding treatment in an ionized gas atmosphere, Nitrogen can be selectively diffused into the edge zone of iron-based alloys or other alloys that contain nitride formers. Plasma nitriding or plasma nitrocarburizing is used in particular to impart high surface hardness to functional surfaces, thereby improving their wear, adhesion and corrosion resistance.

[0035] Alternatively, a tool chuck can be provided, characterized in that a hard material or alloy is or has been sprayed on the functional surface of at least one of the parts joined to one another in the sleeve portion, in particular on the inner circumferential surface of the outer sleeve or on the outer circumferential surface of the inner sleeve or on the inner and / or outer circumferential surface of at least a first intermediate sleeve arranged between the inner and outer sleeves.

[0036] It may further be provided that a second intermediate sleeve is arranged between the inner sleeve and the outer sleeve, whereby the second intermediate sleeve advantageously has a clearance fit with the inner sleeve and / or with the outer sleeve.

[0037] It may also be provided that the intermediate sleeve, arranged between the inner sleeve and the outer sleeve, is made of a copper-containing material, or a shape memory material, or a memory material, or a carbon fiber material, or a hard metal material, or a ceramic material, and / or an Ampco material, and / or has a hardness of at least 50 HRC, in particular the intermediate sleeve being harder than the outer sleeve.

[0038] Thereby, alongside an improvement in the vibration or damping behavior, the sliding properties are also improved due to a sufficient hardness, which can prevent the intermediate sleeve from eroding at the functional surface.

[0039] It is advantageous if the intermediate sleeve arranged between the inner sleeve and the outer sleeve and / or the outer sleeve and / or the inner sleeve has at least one chamber located inside the intermediate sleeve or the outer sleeve or the inner sleeve.

[0040] In this case, it can further be provided that in at least one chamber a damping body, in particular powder or oil, or rolling bodies, in particular balls, rollers, pins, in particular hard metal or ceramic rolling bodies held in a cage (in particular a metal or plastic cage), or rings (made of heavy metal or rubber) or inserts (made of hard metal or rubber), if necessary, biased in particular by a spring, are arranged.

[0041] This makes it possible to further improve the damping and vibration behavior of the tool chuck.

[0042] With appropriate advantageous effects on damping / vibrations, the outer shape of the intermediate sleeve can also have free spaces, for example through grooves, and correspondingly the inner or outer sleeve too.

[0043] According to a further embodiment, it is provided that the outer sleeve is welded or soldered to the tool chuck base, ideally with a flange of the outer sleeve welded or soldered to a complementary counter flange or a complementary annular shoulder of the tool chuck base, in particular by electron beam welding.

[0044] Particularly in the case of such welding or soldering, the expansion gap or undercut is of great advantage, since the thermally related stresses are relieved exactly here.

[0045] It may also be provided (similar to the above-mentioned chambers or functionally similar) that at least one cavity is arranged between the inner sleeve and the outer sleeve and / or within the inner sleeve and / or within the outer sleeve, in which cavity in particular a damping body, in particular powder or oil, in particular hydraulic oil, or ideally rolling elements, in particular balls, rollers or pins, in particular hard metal or ceramic rolling elements held in a cage (in particular a metallic or plastic cage), or (heavy metal or rubber) rings or (hard metal or rubber) inserts, possibly biased in particular by a spring, are arranged.

[0046] This also makes it possible to further improve the damping or vibration behavior of the tool chuck.

[0047] Furthermore, it is also advantageous to flush the at least one cavity with a liquid, in particular water, or a gas, whereby a cooling effect / function can also be achieved in the tool chuck. Such a coolant can in particular be water, CO2, oil, air, MMS or similar.

[0048] In one embodiment, the tool chuck base is provided with a chamber in which is arranged, in particular a damping body, in particular a powder or oil, in particular hydraulic oil, or ideally a ball, roller, pin, in particular a hard metal or ceramic ball, or (heavy metal or rubber) ring, or (hard metal or rubber) insert, held in a cage, in particular a metal or plastic cage, possibly biased in particular by a spring.

[0049] It appears to be particularly useful if the outer sleeve is connected to the inner sleeve or, if the tool chuck has room temperature and does not clamp the tool shank, if at least one first intermediate sleeve is connected to the inner and outer sleeves by press-fitting, since this special "pressurization" aspect of the sleeve parts contributes in particular to improving the clamping ability, the damping behavior and the vibration behavior.

[0050] The outer sleeve is also formed in such a way as to prevent it from shrinking, particularly by the intermediate sleeve, during cooling after its thermal expansion and the insertion of a tool shank to be clamped in a predetermined manner into the inner sleeve, thereby providing a significant contribution to the creation of a press-fit in which the tool shank is held.

[0051] It is also useful if the inner sleeve is configured to be tensioned in the cold state, for example by a "pressed" intermediate sleeve, and to open upon thermal expansion of the outer sleeve through relaxation.

[0052] It is particularly advantageous if the inner sleeve, the outer sleeve and the intermediate sleeve consist of different materials, for example of different types of steel, the inner sleeve consisting of hardened steel, in particular case-hardened steel, thus preferably in the form of a wear-resistant steel, and the outer sleeve consisting of a hot-worked steel.

[0053] Such material differences in particular have a great advantage since thermally induced stresses are attenuated in the stretch gap or undercut.

[0054] It is advantageous if the inner sleeve is not separable and is preferably an integral element of the tool chuck base, which also forms a connection, in particular with the machine tool, and is preferably formed as a cylindrical, or frusto-conical or polygonal conical, or as a KM4X or HSK connection, possibly as regional variants MAS-BT (Asia), ISO / DIN (Europe) and CAT-V (America).

[0055] According to a preferred development, the inner sleeve has a cylindrical or conical outer circumferential surface and the outer sleeve has a complementary cylindrical or conical inner circumferential surface, or the inner sleeve has a cylindrical or conical outer circumferential surface and at least one first intermediate sleeve has a complementary cylindrical or conical inner circumferential surface, or the at least one first intermediate sleeve has a cylindrical or conical outer circumferential surface and the outer sleeve has a complementary cylindrical or conical inner circumferential surface, and / or It is provided that the inner sleeve and the outer sleeve, or the outer sleeve and at least one first intermediate sleeve, or the inner sleeve and at least one first intermediate sleeve are joined to one another by pressing, in which, particularly in the case of a cylindrical configuration of the outer peripheral surfaces of the sleeves, the inner peripheral surface of the outer sleeve is radially undersized relative to the outer peripheral surface of the inner sleeve or relative to the outer peripheral surface of at least one first intermediate sleeve, or the inner peripheral surface of at least one first intermediate sleeve is radially undersized relative to the outer peripheral surface of the inner sleeve.

[0056] The sleeve part also preferably completely, essentially or for the most part forms a centering area in an area outside the axial extent of the tool holder part, the inner sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, which when the inner and outer sleeves are pressed axially together form a guide area in which the inner and outer sleeves first come into contact and are guided relative to one another without significant pressure, in particular when further pressing one against the other, pressure is exerted outside the guide area, Or, the inner sleeve has an enlarged outer diameter and the in particular the second intermediate sleeve has a complementary inner diameter which, when the inner sleeve and, in particular, the second intermediate sleeve are pressed axially, form a guide area in which the inner sleeve and, in particular, the second intermediate sleeve first come into contact and are guided relative to one another without significant pressure, in particular in the course of subsequent further pressing of one against the other, whereupon pressure is exerted outside the guide area, Or, In particular, the second intermediate sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, which inner diameter, in particular when the second intermediate sleeve and the outer sleeve are pressed axially, forms a guide area in which the second intermediate sleeve and the outer sleeve first come into contact and are guided against each other without significant pressure, in particular in the process of subsequently pressing one further against the other, where pressure is applied outside the guide area.

[0057] In this case, it is possible for the guide region or centering region to merge, preferably via a conical transition, into a part of the sleeve part belonging to the tool holder, in particular in the region of this preferably conical transition, such that no contact of the functional surfaces of the sleeve with one another occurs.

[0058] Furthermore, the outer sleeve preferably forms, in front of its guide area in the sliding direction, a flange with a through hole, which is chamfered by a complementary flange or a complementary annular shoulder and is provided with an internal thread hole or a freely protruding stud bolt, and the tool chuck base is preferably formed in such a way that the outer sleeve is pressed onto the inner sleeve by screwing it to the tool chuck base, it is preferably useful if a pressure release device for pressing the outer sleeve is provided, ideally by a pressure screw.

[0059] This form of axial support contributes inter alia to significantly reducing harmful vibrations of the tool chuck.

[0060] It is also possible to provide a coolant passage, preferably opening at the free end of the sleeve portion and supplying coolant to the tool through said opening, wherein at least one coolant passage is formed primarily by a circumferentially closed bore preferably passing through the outer sleeve and / or secondarily by a circumferentially closed bore passing through the inner sleeve.

[0061] In one particularly preferred development, the tool chuck comprises a tool chuck base, a gap extending between the inner sleeve and the outer sleeve, at least one first intermediate sleeve between the inner sleeve and the outer sleeve, and a second intermediate sleeve between the inner sleeve and the outer sleeve, the first intermediate sleeve being arranged by press-fitting between the inner sleeve and the outer sleeve, the first and second intermediate sleeves being arranged axially spaced apart from each other such that the first intermediate sleeve is arranged after the second intermediate sleeve towards the free open end, and a thermochemically heat-treated, in particular plasma- or gas-nitrided, functional surface of at least one of the components joined together is provided, in particular on the inner circumferential surface of the outer sleeve, or on the outer circumferential surface of the inner sleeve, or on the inner and / or outer circumferential surface of at least one of the intermediate sleeves.

[0062] This is precisely where the important aspect of a tool chuck with all the advantages discussed above comes into play.

[0063] The use of the tool chuck provides for high speed machining, particularly high speed milling (HSC), or high performance milling (HPC) or CAD / CAM optimized trochoidal milling, with cutting speeds of 800 m / min or more, more preferably 1,100 m / min or more.

[0064] The tool clamping system provides at least one tool chuck and a shank tool that fits thereto in terms of its nominal shank diameter.

[0065] In conclusion, it can be said that the present invention (in all its aspects presented herein, such as the extension gap / undercut, intermediate sleeve, and thermochemical heat treatment / coating) is characterized by simplicity, efficiency, and effectiveness, particularly in all its aspects.

[0066] The above description of the preferred embodiments of the invention includes a number of features, which are reproduced in part in a combined manner in the individual subclaims. However, these features can be considered individually and combined into useful further combinations where appropriate.

[0067] Although some terms are used in the specification or claims in combination with a singular form or a numeral, the scope of the invention relating to these terms should not be limited to the singular form or the respective numeral. Furthermore, the word "ein" or "eine" should be construed as an indefinite article, not as a numeral.

[0068] The above-mentioned characteristics, features and advantages of the present invention, as well as the manner in which they are achieved, will become clearer and more easily understood in connection with the following description of embodiments of the invention, which are explained in more detail in conjunction with the drawings / figures in which the same parts / components and functions are designated by the same reference numerals.

[0069] The examples are intended to illustrate the invention and are not intended to limit the invention to the combination of features shown therein, nor to the functional features thereof. Moreover, preferred features of each example may be explicitly considered in isolation, deleted from an example, introduced and supplemented in another example, or combined with any of the claims. [Brief description of the drawings]

[0070] [Figure 1a] 1 illustrates a tool chuck, e.g., a shrink fit chuck, with an extension gap and an intermediate sleeve according to one embodiment of the present invention. [Figure 1b] A portion of FIG. 1a is shown enlarged. [Figure 1c] A portion of FIG. 1b is shown enlarged. [Figure 2a] 1 illustrates a tool chuck, e.g., a shrink fit chuck, with an intermediate sleeve having a chamber according to one embodiment of the present invention. [Figure 2b] A portion of FIG. 2a is shown enlarged. [Figure 2c] A portion of FIG. 2b is shown enlarged. [Figure 3a] 1 illustrates a tool chuck, e.g., a shrink fit chuck, with a sphere according to one embodiment of the present invention. [Figure 3b] A portion of FIG. 3a is shown enlarged. [Figure 3c] A portion of FIG. 3b is shown enlarged. [Figure 4a] 1 illustrates a tool chuck, such as a shrink fit chuck, with rollers according to one embodiment of the present invention. [Figure 4b] A portion of FIG. 4a is shown enlarged. [Figure 4c] A portion of FIG. 4b is shown enlarged. [Figure 5a] 1 illustrates a tool chuck, e.g., a shrink-fit chuck, with a damping chamber having a damping element resiliently attached to a tool chuck base, according to an embodiment of the present invention. [Figure 5b] A portion of FIG. 5a is shown enlarged. [Figure 6a]1 illustrates a tool clamping chuck, e.g., a shrink fit chuck, with a thermochemically heat treated functional surface in accordance with one embodiment of the present invention. [Figure 6b] A portion of FIG. 6a is shown enlarged. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] Working Example 1 to 6 show various tool chucks 1 in different views and details.

[0072] Tool chuck 1 with extension gap 11 and intermediate sleeves 13, 14 (FIGS. 1a, b, c) The tool chuck 1 (as a shrink-fit chuck in this embodiment) includes a tool chuck base 2. The tool chuck base 2 is provided at its rear end 3 with a coupling for connecting to a machine tool, and the coupling portion is, for example, an HSK coupling in FIG.

[0073] Alternatively, SK coupling or other methods are also possible. The terms HSK and SK used in the coupling preferably incorporated in this embodiment are well known to those skilled in the art, since they are standardly used in many places.

[0074] At its front free end 9 facing away from the coupling, the tool chuck 1 forms a sleeve portion 4 .

[0075] Inside the sleeve portion 4, a tool holding portion 5 for holding a tool, for example, the shank of an end mill (not shown), is realized.

[0076] The sleeve part 4 forms, axially at the rear, i.e. opposite the front free end 9, an outflow area 6 relative to the tool shank, which is not used by the tool shank or for holding it. A coolant can be supplied to the sleeve part 4 via this outflow area 6.

[0077] This sleeve portion 4 is formed and used in such a way that it can hold the tool shank in a pressed-in condition relative to the tool chuck 1 so that it does not rotate, pull out axially or slip, at least in a significant manner, during operation of the tool.

[0078] Details of the shrink fit process used in this regard, and the formation of the corresponding tool chuck as a shrink fit chuck, are described in U.S. Pat. No. 5,399,623, and U.S. Pat. No. 5,499,623, both of which are incorporated herein in their entirety and, therefore, their features may be referenced (in some cases for purposes of defining the claims of this application).

[0079] With regard to the sleeve part 4, the tool chuck 1 differs from that of the abovementioned application in that the sleeve part 4 is constituted by two layers (7, 8) between which an intermediate body (13, 14) is correspondingly arranged, which, as can be seen in FIG. 1, forms a tool holding part 5 at least along the axial region and in that region and also up to the outflow region 6.

[0080] It is formed in two layers with an intermediate layer, which consists of an inner sleeve 7 (here see the imaginary connection point 17 of the inner sleeve 7 to the tool chuck base body 2 (marked in FIG. 1a) due to its one-piece construction), an outer sleeve 8 and two intermediate sleeves 13, 14 arranged between them and positioned axially relative to one another.

[0081] Between the two intermediate sleeves 13, 14, i.e. between the front intermediate sleeve 13 and the rear intermediate sleeve 14, a (ring-shaped) free space or transition 12 is formed, in which a radial gap remains between the outer sleeve 8 and the inner sleeve 7 even when they are fully assembled and ready for use (see below for the coolant passage 15).

[0082] While the inner sleeve 7 is integrally joined to the tool chuck base 2, the outer sleeve 8 is welded (21) to the tool chuck base 2 by electrowelding (at corresponding joining points 18 (marked in FIG. 1a) of the tool chuck base 2), ideally by welding a flange of the outer sleeve 8 to a complementary mating flange or complementary annular shoulder of the tool chuck base 2 (not shown).

[0083] All parts are preferably made of metal or steel, preferably different types of steel.

[0084] In one embodiment, the tool chuck base 2 may be made of different materials, so that the rear end 3 may be made of, for example, steel, and the inner sleeve 7, which is assembled to the rear end 3 using, for example, an additive process, may be made of a different material, such as another material, for example aluminum.

[0085] At a common joint 22 where the tool chuck base 2, the (one-piece, therefore, only conceptually) inner sleeve 7, and the outer sleeve 8 meet, there is an extension gap 11, or undercut 11 (see especially FIG. 1c). Ideally, by removing material from the tool chuck base 2, the inner sleeve 7, and the outer sleeve 8, a not insignificant, appreciable free space (i.e., the extension gap / undercut 11) is formed between the parts 2, 7, 8 (at the joint 22).

[0086] For example, material can be removed from the inner surface of the outer sleeve 8 (see markings 23 in Figures 1b, c), while material can be removed through grooves 16 in the tool chuck base 2, as shown here.

[0087] The extension gap 11 or undercut 11 of the tool chuck 1, in this case between the tool chuck base 2, the inner sleeve 7 and the outer sleeve 8, enables the tool chuck 1 to relieve stresses, particularly caused by heat (see electron beam welding), and prevent cracks at the joints 22 between the tool chuck base 2, the inner sleeve 7 and the outer sleeve 8.

[0088] The inner sleeve 7 and the outer sleeve 8 are connected to each other without play via the front (i.e. towards or located at the free end 9) intermediate sleeve 13, such that at least the front intermediate sleeve 13 is located in a press fit between the inner sleeve 7 and the outer sleeve 8, while the rear (i.e. towards the rear end 3 facing away from the free end 9 or located opposite the free end) intermediate sleeve 14 can be located in a clearance fit between at least one of the inner sleeve 7 and the outer sleeve 8.

[0089] This rear intermediate sleeve 14 can be easily pressed onto the inner sleeve 7 when the parts are fitted if the (in this case cylindrical) functional surfaces of the inner sleeve 7, the outer sleeve 8 and the rear intermediate sleeve 14 have corresponding undersizes.

[0090] This play at this point is usually present even when the tool chuck 1 has not yet clamped a shank and is sitting unused at room temperature waiting for the next use.

[0091] However, the "clamping system" consisting of the inner sleeve 7, the outer sleeve 8 and the front intermediate sleeve 13 therebetween is under tension due to the press fit (at its functional surfaces), which generates strong vibration-damping friction, especially when "closely fitted".

[0092] These press-ins can be produced in particular by the inner sleeve 7 having a conical outer peripheral surface, at least along the main axial length of the tool holder 5. The front intermediate sleeve 13 has a complementary corresponding conical inner peripheral surface.

[0093] Furthermore, the front intermediate sleeve 13 has, at least along the main axial length of the tool holder 5, a similarly conical outer peripheral surface, and the outer sleeve 8 has a complementary correspondingly conical inner peripheral surface.

[0094] The cone angle will be the same for all (pressure forming) functional surfaces, but this does not necessarily have to be the case: it is also possible, for example, to realize different cone angles by means of a front intermediate sleeve 13 with different inner and outer cone angles (the complementary functional surfaces of the inner sleeve 7 and outer sleeve 8 then corresponding to these cone angles).

[0095] The front intermediate sleeve 13 is forced axially open or pressed against the inner sleeve 7 and the outer sleeve 8 is forced axially open or pressed against the front intermediate sleeve 13, creating the desired pressure.

[0096] This is possible by a shrinkage operation with the above-mentioned parts, in this case without the need for a conical functional surface, which can be achieved in this case by a corresponding oversizing of the functional surface, which is for example cylindrical.

[0097] Furthermore, the tool chuck forms a (coolant) flow path, which runs from the outflow area 6 via a first cooling passage 15a formed in the inner sleeve to the intermediate space 12 between the inner sleeve 7 and the outer sleeve 8 and there between the rear intermediate sleeve 14 and the front intermediate sleeve 13, i.e. at the transition 12, and via a second cooling channel 15b formed in the outer sleeve 8 from the intermediate space / transition 12 to the front free end 9 of the outer sleeve 8, by which the coolant is guided to the end face 24 of the tool chuck 1.

[0098] The two abovementioned channels 15a,b are then essentially made as elongated bores.

[0099] The tool chuck 1 shown in Figures 2 to 6 is constructed / formed according to the tool chuck 1 of Figure 1, but further / other, similarly advantageous details (only) are described in more detail in relation to the respective Figures 2, 3, 4, 5 and 6. Details shown in Figures 2 to 6 but not mentioned can be inferred (from the description of) Figure 1.

[0100] Tool chuck 1 with intermediate sleeve having chambers 27a,b (Fig. 2a,b,c) In this tool chuck 1, the front intermediate sleeve 13 and possibly also the rear intermediate sleeve 14, as shown here, each have an internal (annular) chamber 27 or 27b. The two (annular) chambers 27a,b of the intermediate sleeves 13, 14 are in this embodiment unfilled, thus providing free spaces or cavities 28a,b respectively (see also Figures 3 and 4).

[0101] This free space / cavity 28a or 28b or such a “hollow, annular” chamber 27a or 27b contributes in particular to improving the vibration and damping behavior in the tool chuck 1.

[0102] Tool chuck 1 with ball 19 (Fig. 3a, b, c) The tool chuck 1 shown in this embodiment comprises a sphere 19 ("3-dimensional sphere") held / guided in a sphere cage 20, instead of the front intermediate sleeve 13 described above.

[0103] Here too, the ball 19 is under pressure (from the outer sleeve 8 and the inner sleeve 7), so that the "clamping system" consisting of the inner sleeve 7, the outer sleeve 8 and, in this case, the "ball" between them, is under tension and thereby particularly "tight", which generates strong vibration-damping friction.

[0104] The balls 19 are arranged here by a press fit, but this does not have to be the case for the cage 20. The cage 20 may also be arranged with play between the inner sleeve 7 and the outer sleeve 8. Alternatively, a press fit is also possible for the cage 20.

[0105] The sphere, or these spheres 19 (distributed in a hollow cylinder), also contribute to improving the vibration and damping behavior in the tool chuck 1 .

[0106] Tool chuck 1 with rollers 19 (Fig. 4a, b, c) The tool chuck 1 shown in this embodiment (similar to that of FIG. 3) has, instead of the front intermediate sleeve 13 described above, a (cylindrical) roller 19 (a "three-dimensional roller body") held / guided in a roller cage 20.

[0107] Here too, the roller 19 is under pressure (from the inner sleeve 7 and the outer sleeve 8) so that the "clamping system" consisting of the inner sleeve 7, the outer sleeve 8 and, in this case, the "roller body" between them, is under tension and therefore particularly "tight", which generates strong vibration-damping friction.

[0108] Although the rollers 19 are arranged here by a press fit, this does not have to be the case for the cage 20. The cage 20 may also be arranged with play between the inner sleeve 7 and the outer sleeve 8. Alternatively, a press fit is also possible for the cage 20.

[0109] This roller body or these (hollow cylindrically distributed) rollers 19 also contribute to improving the vibration and damping behavior in the tool chuck 1 .

[0110] Tool chuck 1 with damping chamber having spring-mounted damping element 19 in tool chuck base 2 (FIGS. 5a, b) The tool chuck 1 is disposed within a tool chuck base 2 and includes an annular chamber 29 .

[0111] In this annular chamber 29 a hollow cylindrical damping body 19, in this case made of hard rubber, is resiliently mounted.

[0112] This influences the vibration behavior and thus the damping behavior of the tool chuck 1 in a particularly advantageous and improved manner.

[0113] Tool chuck 1 with chemically heat-treated functional surface 26 (FIG. 6a, b) In this tool chuck 1, the functional surface 26 of the "clamping system" consisting of the inner sleeve 7 (outer), the outer sleeve 8 (inner) and the front intermediate sleeve 13 (inner and outer) is thermochemically heat treated, in this case by plasma nitriding or plasma soft nitriding, to give the functional surface 26 a high surface hardness which thereby enhances its wear resistance, adhesion resistance and corrosion wear resistance.

[0114] Moreover, the functional surface 26 thus treated may preferably act in a vibration reducing manner.

[0115] If all functional surfaces 26 of the "clamping system" consisting of the inner sleeve 7 (outside), the outer sleeve 8 (inside) and the front intermediate sleeve 13 (inside and outside) are thermochemically heat-treated, it is also possible to (thermochemically) treat only individual functional surfaces 26, for example the outside and inside of the front intermediate sleeve 13 or the inside of the outer sleeve 8 and the outside of the inner sleeve 7, so that at least one functional surface of each press-fit is treated.

[0116] The tool chuck 1, in this embodiment shown outside the tool chuck base 2, also comprises various (balance (screw)) holes 10, into which masses, in this case balance screws, can be filled during balancing.

[0117] Although the present invention has been illustrated and described in more detail by means of preferred embodiments, the invention is not limited to the disclosed embodiments, and other variations can be derived therefrom without departing from the scope of protection of the invention.

[0118] Furthermore, all features shown in the figures may, individually or in combination, be essential to the invention or at least beneficial to the invention and may therefore also be claimed individually or in combination (in the claims). [Explanation of symbols]

[0119] 1 Tool chuck 2 Tool chuck base 3 Rear end 4 Sleeve section 5 Tool holding part 6 Outflow area 7 Inner Sleeve 8 Outer Sleeve 9 Front, free end 10 Balance screw (balance (screw)) holes 11 Extension gap, undercut 12 Transition 13 Front middle sleeve 14 Rear intermediate sleeve 15a, b Coolant passage, coolant hole 16 Groove (inside 2) 17 Joint 18 Welding and joining points 19 Damping bodies, damping elements, balls, rollers 20 (ball / roller) cage 21 Welding / soldering, electron beam welding 22 Joints 23 Marking for material removal (8 places) 24 End face 26 Thermochemically heat treated areas / functional surfaces, coatings 27a,b Chamber 28a,b Free space / cavity within the chamber 29 (Damping) Chamber (in 2)

Claims

1. 1. A tool chuck for clamping a tool having a tool shank, comprising: a sleeve part, preferably made of an electrically conductive material, which is open at a free end of the tool chuck and connected to the tool chuck base towards the free end, said sleeve part forming a tool holding part for friction locking of the tool shank by press-fitting, in particular by shrink-fitting, A tool chuck, in which the sleeve part preferably comprises, at least over the entire axial length of the tool holder, an inner sleeve and an outer sleeve which holds the inner sleeve in an operating state and which is joined without play, the outer sleeve preferably being made of an electrically conductive material, A tool chuck characterized by an extending gap between said tool chuck base, said inner sleeve, and said outer sleeve.

2. 2. The tool chuck according to claim 1, wherein a poked groove or groove forming a free space in the extension gap is formed in the tool chuck base.

3. 1. A tool chuck for clamping a tool having a tool shank, comprising: a sleeve part, preferably made of an electrically conductive material, which is open at a free end of the tool chuck and connected to the tool chuck base towards the free end, said sleeve part forming a tool holding part for friction locking of the tool shank by press-fitting, in particular by shrink-fitting, A tool chuck, in which the sleeve part preferably comprises, at least over the entire axial length of the tool holder, an inner sleeve and an outer sleeve which holds the inner sleeve in an operating state and which is joined without play, the outer sleeve preferably being made of an electrically conductive material, The tool chuck of claim 1 , characterized by at least a first intermediate sleeve between said inner sleeve and said outer sleeve.

4. A tool chuck according to any one of claims 1 to 3, characterized in that the at least one first intermediate sleeve has an interference fit with the inner sleeve and / or the outer sleeve.

5. Tool chuck according to any one of the preceding claims, characterized by a second intermediate sleeve between the inner sleeve and the outer sleeve.

6. A tool chuck according to any one of the preceding claims, characterized in that the second intermediate sleeve has a clearance fit with the inner sleeve and / or the outer sleeve.

7. 7. A tool chuck according to claim 1, characterized in that an intermediate sleeve arranged between the inner sleeve and the outer sleeve consists of a copper-containing material, or a shape memory material, or a memory material, or a carbon fiber material, or a hard metal material, or a ceramic material and / or an Ampco material, and / or has a hardness of at least 50 HRC, in particular the intermediate sleeve being harder than the outer sleeve.

8. 8. A tool chuck according to claim 1, characterized in that an intermediate sleeve arranged between the inner sleeve and the outer sleeve and / or the outer sleeve and / or the inner sleeve has at least one chamber located inside the intermediate sleeve or the outer sleeve or the inner sleeve.

9. A tool chuck according to any one of claims 1 to 8, characterised in that in at least one chamber a damping body, in particular powder or oil, or in particular or ideally rolling bodies, in particular balls, rollers, pins, in particular hard metal or ceramic rolling bodies held in a cage, in particular a metal or plastic cage, or rings (made of heavy metal or rubber) or inserts (made of hard metal or rubber), if necessary, in particular biased by a spring, are arranged.

10. 1. A tool chuck for clamping a tool having a tool shank, comprising: a sleeve part, preferably made of an electrically conductive material, which is open at a free end of the tool chuck and connected to the tool chuck base towards the free end, said sleeve part forming a tool holding part for friction locking of the tool shank by press-fitting, in particular by shrink-fitting, A tool chuck, in which the sleeve part preferably comprises, at least over the entire axial length of the tool holder, an inner sleeve and an outer sleeve which holds the inner sleeve in an operating state and which is joined without play, the outer sleeve preferably being made of an electrically conductive material, or the functional surface of at least one of the components joined together in the sleeve section is thermochemically heat treated and / or coated, in particular on the inner circumferential surface of the outer sleeve or on the outer circumferential surface of the inner sleeve or on the inner and / or outer circumferential surface of at least a first intermediate sleeve arranged between the inner and outer sleeves, or 4. A tool chuck according to claim 1 or 3, characterized in that a hard material or alloy is or has been sprayed on the functional surface of at least one component joined to one another in the sleeve portion, in particular on the inner circumferential surface of the outer sleeve or on the outer circumferential surface of the inner sleeve or on the inner and / or outer circumferential surface of at least a first intermediate sleeve arranged between the inner sleeve and the outer sleeve.

11. A tool chuck according to any one of claims 1 to 10, characterized in that the thermochemical heat treatment is nitriding by diffusion of nitrogen, such as for example plasma nitriding, vacuum nitriding or gas nitriding, or nitriding by diffusion of nitrogen and carbon, such as for example gas soft nitriding, plasma soft nitriding or salt bath soft nitriding.

12. A tool chuck according to any one of claims 1 to 11, characterised in that the outer sleeve is welded or soldered to the tool chuck base, ideally a flange of the outer sleeve is welded, in particular electron beam welded or soldered to a complementary counter flange or to a complementary annular shoulder of the tool chuck base.

13. 13. A tool chuck according to any one of claims 1 to 12, characterised in that at least one cavity is arranged between the inner sleeve and the outer sleeve and / or within the inner sleeve and / or within the outer sleeve, in which cavity in particular a dampening body, in particular powder or oil, in particular hydraulic oil, or ideally rolling elements, in particular balls, pins, in particular hard metal or ceramic rolling elements held in a cage (in particular a metallic or plastic cage), or (heavy metal or rubber) rings or (hard metal or rubber) inserts, if necessary biased in particular by a spring, are arranged.

14. Tool chuck according to any one of the preceding claims, characterized in that the at least one cavity is flushed with a liquid, in particular water, or with a gas.

15. A tool chuck according to any one of claims 1 to 14, characterised in that the tool chuck base is provided with a chamber in which is arranged in particular a damping body, in particular a powder or an oil, in particular hydraulic oil, or ideally balls held in a cage (in particular a metal or plastic cage), in particular hard metal or ceramic balls, or (heavy metal or rubber) rings or (hard metal or rubber) inserts, possibly biased in particular by a spring.

16. 16. A tool chuck according to claim 1, characterized in that the outer sleeve is connected to the inner sleeve or, when the tool chuck has room temperature and is not clamping the tool shank, at least a first intermediate sleeve is connected to the inner sleeve and to the outer sleeve by press-fitting.

17. A tool chuck according to any one of claims 1 to 16, characterized in that the outer sleeve is formed in such a way as to prevent it from shrinking during cooling after its thermal expansion and insertion of the tool shank to be clamped in a defined manner into the inner sleeve, thereby contributing significantly to the formation of a press-fit in which the tool shank is held.

18. 18. A tool chuck as claimed in any one of claims 1 to 17, characterized in that the inner sleeve is in tension in a cold state and is configured to open when the outer sleeve thermally expands due to relaxation.

19. 19. A tool chuck according to any one of the preceding claims, characterised in that the inner sleeve and / or the outer sleeve and / or the intermediate sleeve are made of different materials, for example different types of steel, the inner sleeve being made of hardened steel, in particular case-hardened steel, thus preferably in the form of a wear-resistant steel, and the outer sleeve being made of hot-work steel.

20. 20. A tool chuck according to any one of claims 1 to 19, characterized in that the inner sleeve is not separable, preferably is an integral element of the tool chuck base body, which integral element also forms a connection, in particular with a machine tool, and is preferably formed as a cylindrical, or steep-conical, or polygonal-conical, or KM4X or HSK connection, possibly as regional variants MAS-BT (Asia), ISO / DIN (Europe) and CAT-V (America).

21. the inner sleeve has a cylindrical or conical outer circumferential surface and the outer sleeve has a complementary cylindrical or conical inner circumferential surface, or the inner sleeve has a cylindrical or conical outer circumferential surface and at least one first intermediate sleeve has a complementary cylindrical or conical inner circumferential surface, or the at least one first intermediate sleeve has a cylindrical or conical outer circumferential surface and the outer sleeve has a complementary cylindrical or conical inner circumferential surface, and / or 21. A tool chuck according to claim 1, characterized in that the inner sleeve and the outer sleeve, or the outer sleeve and the at least one first intermediate sleeve, or the inner sleeve and the at least one first intermediate sleeve, are joined to one another by pressing, in which, in particular in the case of a cylindrical configuration of the outer peripheral surfaces of the sleeves, the inner peripheral surface of the outer sleeve is radially undersized relative to the outer peripheral surface of the inner sleeve, or relative to the outer peripheral surface of the at least one first intermediate sleeve, or the inner peripheral surface of the at least one first intermediate sleeve is radially undersized relative to the outer peripheral surface of the inner sleeve.

22. the sleeve part preferably completely, essentially or for the most part forms a centering area in an area outside the axial extent of the tool holder part, the inner sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, which when the inner and outer sleeves are pressed axially together form a guide area in which the inner and outer sleeves first come into contact and are guided relative to one another without significant pressure, in particular in the course of further pressing one against the other, whereupon pressure is exerted outside the guide area, Or, the inner sleeve has an enlarged outer diameter and the second intermediate sleeve in particular has a complementary inner diameter, which inner diameter, when the inner sleeve and in particular the second intermediate sleeve are pressed axially, forms a guide area in which the inner sleeve and in particular the second intermediate sleeve first come into contact and are guided relative to one another without significant pressure, in particular in the course of subsequent further pressing of one against the other, whereupon pressure is exerted outside the guide area, Or, A tool chuck according to any one of claims 1 to 21, characterized in that in particular the second intermediate sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter which, in particular when the second intermediate sleeve and the outer sleeve are pressed axially, forms a guide area in which the second intermediate sleeve and the outer sleeve first come into contact and are guided against each other therein without significant pressure, in particular in the course of subsequent further pressing of one against the other, where pressure is applied outside the guide area.

23. 23. A tool chuck according to claim 1, characterized in that the guide region or centering region merges into a part of the sleeve part belonging to the tool holder via a preferably conical transition, in particular in the region of this preferably conical transition, whereby no contact of the functional surfaces of the sleeve parts with one another occurs.

24. A tool chuck according to any one of claims 1 to 23, wherein the outer sleeve preferably forms, in front of its guidable area, in the sliding direction, a flange with a through hole, which is chamfered by a complementary flange or a complementary annular shoulder and is provided with an internal threaded hole or a freely protruding stud bolt, and the tool chuck is preferably formed in such a way that the outer sleeve is pressed onto the inner sleeve by screwing it onto the tool chuck base, and preferably a pressure release device for pressing the outer sleeve is provided, ideally by a pressure screw.

25. 25. A tool chuck according to any one of claims 1 to 24, comprising a coolant passage, preferably opening at a free end of the sleeve part and supplying coolant to the tool by means of said opening, characterised in that at least one coolant passage is formed primarily by a circumferentially closed bore, preferably through the outer sleeve, and / or secondarily by a circumferentially closed bore through the inner sleeve.

26. a gap extending between the tool chuck base, the inner sleeve, and the outer sleeve; at least one first intermediate sleeve between the inner sleeve and the outer sleeve; a second intermediate sleeve between the inner sleeve and the outer sleeve, wherein the first intermediate sleeve is disposed between the inner sleeve and the outer sleeve by press fitting, and the first and second intermediate sleeves are axially spaced from each other such that the first intermediate sleeve is disposed after the second intermediate sleeve toward a free open end; 26. A tool chuck according to claim 1, characterized in that it comprises a thermochemically heat-treated, in particular plasma- or gas-nitrided, functional surface of at least one of the parts joined together, in particular on the inner circumferential surface of the outer sleeve, or on the outer circumferential surface of the inner sleeve, or on the inner and / or outer circumferential surface of at least one of the intermediate sleeves.

27. Use of a tool chuck according to any one of claims 1 to 26 for high speed machining, in particular for High Speed ​​Milling (HSC) or CAD / CAM optimised trochoidal milling, preferably with cutting speeds of 800 m / min or more, more preferably 1,100 m / min or more, or for High Performance Milling (HPC).

28. At least a tool chuck according to any one of claims 1 to 26, and a tool shank that is adapted thereto in terms of its nominal shank diameter.

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