Cutter chuck

Abstract

The invention relates to a tool chuck, a special use of the tool chuck and a chuck system formed by using the tool chuck. A tool chuck for clamping a tool having a tool shank has a sleeve portion which is open at its free end and which is connected to a tool chuck base body towards the free end. The sleeve part forms a tool receptacle for frictionally securing the tool shank in a press-fit manner. The sleeve part is composed of an inner sleeve and an outer sleeve. In this case, the outer sleeve accommodates the inner sleeve in a ready-to-operate state and engages with the inner sleeve without play. The tool chuck is characterized in that the tool chuck base body, the extension gap between the inner sleeve and the outer sleeve, and at least one first intermediate sleeve between the inner sleeve and the outer sleeve, or in that the active surface of at least one of the components that engage with each other in the sleeve portion is thermally chemically heat-treated and / or coated.

Description

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

[0002] Collets in the form of shrink-fit collets have proven to be very effective in practice, since they can exert very high holding forces with little effort. In addition, these collets offer the possibility of holding the clamped tool with great bending stiffness, so that the clamped tool is guided precisely and highly accurate geometries are produced at the workpiece during the cutting process. However, at the same time, these collets usually clamp the tool shank very rigidly or stiffly, so that vibration problems become non-negligible.

[0003] The quality of the clamping of shank tools is particularly important for the quality of the machining that can be achieved with the tool and is often also important for the tool's service life.

[0004] This is more suitable for high-speed cutting of metals, especially when the cutting speed is greater than 800m / min or even greater than 1,100m / min.

[0005] The clamping quality also depends in particular on the degree of damping of any vibrations that may occur. The main source of such vibrations can be, for example, a rapid change in the number of milling cutter edges that are currently in engagement with the workpiece in a chip-reducing manner. This can lead to, for example, highly influential bending vibrations.

[0006] Different types of vibrations, but equally disadvantageous, can be caused by the tendency of shank tools, and in particular end mills, to roll during operation. “Rolling” is understood to be a slight elastic deformation of the tool shank that occurs repeatedly with each rotation and varies locally during the rotation due to contact with the workpiece under feed load.

[0007] DE 10 2021 119 935 A1 known from the prior art takes these requirements into account by providing a tool chuck for clamping a tool having a tool shank, the tool chuck having a sleeve portion which is open at its free end and is made of a preferably conductive material, the sleeve portion forming a tool receptacle for fixing the tool shank in a friction fit by shrinking in a press fit manner, wherein the sleeve portion is preferably composed of an inner sleeve and an outer sleeve which is preferably also made of a conductive material over at least the entire axial length of the tool receptacle, the outer sleeve accommodating the inner sleeve in a ready-to-operate state and engaging with the inner sleeve without play.

[0008] Purpose of the Invention

[0009] The object of the present invention is to provide a tool chuck which further improves the known chucks and in particular makes it possible to apply greater clamping forces and at the same time better cope with vibrations that occur.

[0010] Solution

[0011] This object is achieved by a tool chuck, a use of a tool chuck and a tool clamping system having the features of the respective independent claims.

[0012] Advantageous developments of the invention are the subject matter of the dependent claims and of the following description and relate both to the tool holder, the use and to the tool clamping system.

[0013] Terms such as "upper", "lower", "front", "rear", "left", or "right" used where necessary should be understood according to common understanding and in consideration of the drawings herein, unless otherwise expressly defined. Terms such as "radial" and "axial", if used but not expressly defined, should be understood with reference to the central axis or axis of symmetry of the member / component described herein and in consideration of the drawings herein.

[0014] Whenever used, the term "substantially" is understood (as understood by the Supreme Court) to mean "still to a substantial degree in practice". Possible deviations from the precision implied by the term may occur unintentionally (i.e. without functional reason) due to manufacturing or assembly tolerances, etc.

[0015] A tool chuck for clamping a tool having a tool shank (eg, a milling tool, a drilling tool) has a sleeve portion which is open at a free end thereof and connected to a tool chuck base body toward the free end.

[0016] The sleeve portion forms a tool receptacle for fixing the tool shank in a friction fit, particularly by shrinking, in a press fit manner. Here, the sleeve portion can preferably be made of an electrically conductive material.

[0017] The sleeve portion is preferably composed of an inner sleeve and an outer sleeve at least on the whole axial length of the tool receptacle. Here, the outer sleeve accommodates the inner sleeve under a ready-to-run state and engages with the inner sleeve without play.

[0018] The outer sleeve may also preferably be made of an electrically conductive material.

[0019] The tool chuck is characterized by the expansion gap between the tool chuck base body, the inner sleeve and the outer sleeve.

[0020] In this context, an “expansion gap” may be understood to mean a (narrow) free space between two or more components, in this case between the tool holder basic body, the inner sleeve and the outer sleeve.

[0021] Preferably, such expansion gaps are used anywhere (eg, at a joint) where components made of different materials and / or having different properties (eg, susceptibility to thermal contraction and expansion) come together.

[0022] The term “expansion gap” may have a functional meaning in addition to its physical meaning as a gap, namely to reduce stresses and prevent cracks, and alternatively, the expansion gap provided in the tool holder may also be referred to as or regarded as an undercut.

[0023] In this case, an “undercut” which also has a production-related significance may be a certain shape and fixed-size removal in the surface of a component (here, the tool chuck base body, the inner sleeve and the outer sleeve) which creates a free space there (see expansion gap). This free space is especially visible / formed when the components there (i.e., here, the tool chuck base body, the inner sleeve and the outer sleeve) are joined to one another.

[0024] Simply and clearly, the tool chuck is characterized in that a free space (i.e., an expansion gap or undercut) is provided at the joint between the tool chuck base body, the inner sleeve and the outer sleeve, and the free space is conveniently and simply formed by removing material or "subtracting" at the tool chuck base body, the inner sleeve and the outer sleeve (when the inner sleeve is integral, the free space is correspondingly formed on the tool chuck base body, see below).

[0025] The tool chuck achieves stress reduction and crack prevention at the junction of the tool chuck base body, inner sleeve and outer sleeve by means of the expansion gap or undercut on the tool chuck (more precisely here between the tool chuck base body, inner sleeve and outer sleeve). In particular, the service life of the tool chuck and / or the quality of the tool chuck and all its properties, such as, in particular, its damping, can thereby be extended or improved.

[0026] It may be particularly expedient if a recess is formed in the expansion gap or undercut, which provides a free space in the tool holder basic body, or more precisely, this free space.

[0027] The tool holder may further be characterized by at least one first intermediate sleeve between the inner sleeve and the outer sleeve.

[0028] By means of the at least one first intermediate sleeve between the inner sleeve and the outer sleeve, the tool chuck achieves a significant reduction in the tendency of the tool chuck to generate unfavorable vibrations. In short, the damping / vibration behavior of the tool chuck is improved.

[0029] This seems to be achieved by the boundary layer of the intermediate sleeve and the inner sleeve or outer sleeve in contact with each other in the area of ​​the tool receptacle. In particular, if metal touches metal, damping or weakening of the ability to transmit vibrations will occur.

[0030] This applies in particular to the case where the intermediate sleeve, the inner sleeve and the outer sleeve are in non-detachable contact with one another (e.g. pressed against one another) during normal operation, in particular because they are already pressed against one another before clamping of the tool shank and before the resulting strains are prevented, and their pressing is intensified by clamping of the tool shank.

[0031] It may therefore also be particularly expedient if the at least one first intermediate sleeve has an interference fit with the inner sleeve and / or the outer sleeve.

[0032] The tool chuck can be further characterized in that, in particular, on the inner circumference of the outer sleeve or on the outer circumference of the inner sleeve, or on the inner circumference and / or outer circumference of at least one or the first intermediate sleeve arranged between the inner sleeve and the outer sleeve, the active surface of at least one component of the components engaged with each other in the sleeve portion is thermochemically heat treated and / or coated.

[0033] By means of coating, but in particular by means of a thermochemical heat treatment, it is possible to impart a higher surface hardness to the active surfaces of the tool holder, thereby achieving a better resistance to frictional wear, adhesive wear and corrosive wear.

[0034] It may be particularly advantageous if the thermochemical heat treatment is nitriding with diffusion of nitrogen, such as plasma, vacuum or gas nitriding, or nitriding with diffusion of nitrogen and carbon, such as gas, plasma or salt bath nitrocarburizing.

[0035] Thus, during plasma nitriding and plasma nitrocarburizing in an ionized gas atmosphere, it is possible to diffuse nitrogen in a targeted manner into the surface region of an iron-based alloy or other alloy containing nitrides. In particular, plasma nitriding methods or plasma nitrocarburizing methods are used in order to impart a higher surface hardness to the active surface, thereby achieving a better resistance to frictional wear, adhesive wear and corrosive wear.

[0036] Alternatively, it can also be proposed that the tool chuck is also characterized in that a hard material or alloy is sprayed or has been sprayed onto the active surface of at least one of the components that engage with each other in the sleeve portion, in particular, onto the inner circumference of the outer sleeve or the outer circumference of the inner sleeve, or onto the inner circumference and / or outer circumference of at least one intermediate sleeve arranged between the inner sleeve and the outer sleeve or the first intermediate sleeve.

[0037] It can also be proposed that a second intermediate sleeve is arranged between the inner sleeve and the outer sleeve. Here, it is also advantageous in this case that the second intermediate sleeve has a loose fit with the inner sleeve and / or the outer sleeve.

[0038] It can also be proposed that: the intermediate sleeve arranged between the inner sleeve and the outer sleeve or the intermediate sleeve is made of copper-containing material or shape memory material or memory material or carbon fiber material or hard metal material or ceramic material, and / or has Ampco material and / or has a hardness of at least 50HRC; in particular, the intermediate sleeve is harder than the outer sleeve.

[0039] In addition to the improvement in the vibration or damping behavior achieved thereby, better sliding properties are achieved with sufficient hardness, which prevents the intermediate sleeve from getting stuck on the active surface.

[0040] It is also advantageous if the intermediate sleeve arranged between the inner sleeve and the outer sleeve or the intermediate sleeve and / or the outer sleeve and / or the inner sleeve has at least one chamber within the intermediate sleeve or the outer sleeve or the inner sleeve.

[0041] Therefore, as an improvement, it can also be proposed that a damping body, in particular powder or oil, or, ideally, a rolling body held in a cage (in particular a metal or plastic cage), in particular balls, rollers or needles, in particular hard metal or ceramic rolling bodies, or a (heavy metal or rubber) ring or a (hard metal or rubber) insert is arranged in the at least one chamber, and if necessary, the damping body is pre-tightened, in particular by a spring.

[0042] As a result, the damping or vibration behavior of the tool holder can be further improved.

[0043] Furthermore, the outer geometry of the intermediate sleeve can also have free spaces, for example formed by grooves, while providing a corresponding advantageous damping / vibration effect. The same is true for the inner sleeve and the outer sleeve accordingly.

[0044] In another embodiment, the outer sleeve is welded or brazed to the tool holder basic body, ideally in that a collar of the outer sleeve is welded or brazed to a complementary mating collar or a complementary annular shoulder of the tool holder basic body, in particular by electron beam welding.

[0045] Particularly in the case of such welding or soldering, expansion gaps or undercuts have proven to be particularly advantageous, precisely in this case reducing the stresses caused by heat.

[0046] It can also be proposed that (similarly or functionally similarly to the above-mentioned chamber) at least one cavity is arranged between the inner sleeve and the outer sleeve and / or in the inner sleeve and / or the outer sleeve, in which at least one cavity a damping body is arranged in particular, in particular a powder or oil, in particular hydraulic oil, or ideally rolling bodies held in a cage (in particular a metal or plastic cage), in particular balls, rollers or needles, in particular hard metal or ceramic rolling bodies, or (heavy metal or rubber) rings or (hard metal or rubber) inserts, and the damping body is preloaded if necessary, in particular by a spring.

[0047] The damping or vibration behavior of the tool holder can also be further improved in this way.

[0048] Furthermore, it is also advantageous to flush the at least one cavity with a fluid, in particular water, or with a gas, so that a cooling effect / function can also be achieved in the tool holder. Such a coolant can be in particular water, CO2, oil, air, MMS, etc.

[0049] In one embodiment, a chamber is also provided in the tool chuck base body, in which an object is arranged, in particular a powder or oil, in particular hydraulic oil, or ideally balls, rollers or needles, in particular hard metal or ceramic balls, or (heavy metal or rubber) rings or (hard metal or rubber) inserts, which are retained in a cage (in particular a metal or plastic cage) and which are preloaded, if necessary, in particular by a spring.

[0050] In particular, it is particularly convenient that the outer sleeve and the inner sleeve or the at least one first intermediate sleeve and the inner sleeve and the outer sleeve are connected to each other by a press fit even if the tool chuck has room temperature and does not hold any tool shank in a clamped manner. This type of "preload" in the sleeve part helps to improve the clamping properties, damping and vibration behavior in particular.

[0051] It can also be proposed that the outer sleeve is designed so that after its thermal expansion and after the tool shank to be clamped as intended is inserted into the inner sleeve, in particular by one of the intermediate sleeves or by the intermediate sleeve, the outer sleeve is prevented from shrinking when cooling again and thus contributes to a great extent to creating a press fit that holds the tool shank therein.

[0052] It may also be expedient if the inner sleeve is designed such that it is stressed in the cold state (eg due to a "squeezed" middle sleeve) and opens due to stress relief when the outer sleeve expands thermally.

[0053] It has proven to be particularly advantageous if the inner sleeve and the outer sleeve and the intermediate sleeve are made of different materials, for example different types of steel, for example hardened, in particular case-hardened and therefore preferably wear-resistant steel for the inner sleeve and hot working tool steel for the outer sleeve.

[0054] Particularly in the case of such material differentiation, expansion gaps or undercuts have proven to be particularly advantageous, precisely in this case reducing thermally induced stresses.

[0055] From a production technology perspective, it can also be advantageous if the inner sleeve is an inseparable, preferably integral component of the tool chuck base body (see integral connection above), the tool chuck base body also forming, in particular, a coupling for a machine tool, preferably in cylindrical form or as a short taper coupling or polygonal taper shank coupling or KM4X or HSK coupling, if necessary as a regionally restricted variant MAS-BT (in Asia), ISO / DIN (in Europe) and CAT-V (in America).

[0056] According to a preferred improvement, 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 the 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;

[0057] and / or

[0058] 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 each other by extrusion, wherein, especially when the circumference of these sleeves is implemented as a cylinder, the inner circumference of the outer sleeve has a smaller diameter relative to the outer circumference of the inner sleeve or relative to the outer circumference of the at least one first intermediate sleeve, or the inner circumference of the at least one first intermediate sleeve has a smaller diameter relative to the outer circumference of the inner sleeve.

[0059] It can also be provided that the sleeve part preferably completely, substantially or largely forms the centering region in an outer region of the axial extension of the tool receptacle.

[0060] In this way, the inner sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, and when the inner sleeve and the outer sleeve are pressed against each other, the centering area forms a guide area in the axial direction, in which the inner sleeve and the outer sleeve come into contact with each other for the first time and are not brought into appreciable pressure against each other there, and in particular pressure against each other occurs only outside the guide area during the further pushing toward each other;

[0061] or

[0062] In this way, the inner sleeve has an enlarged outer diameter and the intermediate sleeve, in particular the second intermediate sleeve, has a complementary inner diameter, and when the inner sleeve and the intermediate sleeve, in particular the second intermediate sleeve, are pressed against each other, the centering region forms a guide region in the axial direction, in which the inner sleeve and the intermediate sleeve, in particular the second intermediate sleeve, come into contact with each other for the first time and are not brought into appreciable pressure against each other there, and in particular pressure is only produced outside the guide region during the further pushing toward each other;

[0063] or

[0064] The intermediate sleeve, in particular the second intermediate sleeve, has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, and when the intermediate sleeve, in particular the second intermediate sleeve, and the outer sleeve are pressed against each other, the centering area forms a guide area in the axial direction, in which the intermediate sleeve, in particular the second intermediate sleeve, and the outer sleeve come into contact with each other for the first time and are not subjected to any significant compression against each other at this point, so that compression occurs outside the guide area, in particular only during the further pushing toward each other.

[0065] Here, the guide or centering region can also transition via a preferably conical transition section into the section of the sleeve part assigned to the tool receptacle, wherein in particular in the region of the preferably conical transition section, the active surfaces of the sleeve do not come into contact with one another.

[0066] Furthermore, it may prove to be convenient that the outer sleeve preferably forms a flange with a through hole behind its possible guide area in the pushing direction, toward which a complementary flange or a complementary annular shoulder with a nut threaded hole or a freely protruding stud faces, the complementary flange or the complementary annular shoulder being formed by the tool chuck base body, preferably in such a way that the outer sleeve can be pressed onto the inner sleeve by means of a clamping screw in an ideal situation by being screwed to the tool chuck base body, wherein an extrusion device is preferably provided for extruding the outer sleeve again.

[0067] This form of axial support helps in particular to significantly reduce the tool holder's tendency to generate undesirable vibrations.

[0068] A coolant channel can also be provided, which preferably opens out at the free end of the sleeve portion so as to output coolant to the tool via its opening there, wherein the at least one coolant channel is preferably primarily composed of a circumferentially closed hole passing through the outer sleeve and / or secondarily composed of a circumferentially closed hole passing through the inner sleeve.

[0069] A particularly preferred development also provides: a tool holder base body, an expansion gap (more precisely the expansion gap) between the inner sleeve and the outer sleeve, at least one first intermediate sleeve (more precisely the first intermediate sleeve) between the inner sleeve and the outer sleeve, and a second intermediate sleeve (more precisely the second intermediate sleeve) between the inner sleeve and the outer sleeve, wherein the first intermediate sleeve is arranged between the inner sleeve and the outer sleeve with an interference fit, and the first intermediate sleeve and the second intermediate sleeve are arranged axially spaced apart from each other in such a way that the first intermediate sleeve is arranged behind the second intermediate sleeve in the direction of the freely open end. In addition, the development also provides for a thermochemically heat-treated, in particular plasma- or gas-nitrided, active surface of at least one of the components that join together in the sleeve part, in particular at the inner circumference (more precisely the inner circumference) of the outer sleeve, or at the outer circumference (more precisely the outer circumference) of the inner sleeve, or at the inner circumference and / or outer circumference (more precisely the inner circumference and / or outer circumference) of at least one intermediate sleeve.

[0070] It is in this context that all the fundamental aspects of the tool holder and all of its above-mentioned advantages come into play.

[0071] The tool chuck or the tool chuck is used for high-speed cutting, especially high-speed milling (HSC), or high-performance milling (HPC) or CAD / CAM optimized trochoidal milling, and high-speed cutting and high-speed milling are both carried out at a cutting speed of more than 800m / min, more preferably more than 1,100m / min.

[0072] The tool clamping system is provided with at least one or the tool chuck and a shank-type tool which is matched to the tool chuck in terms of the nominal shank diameter of the tool chuck.

[0073] Finally, it is established for the invention (all its aspects presented here, such as expansion gap / undercut, intermediate sleeve and thermochemical heat treatment / coating) that the invention and all its aspects are characterized in particular by simplicity, efficiency and effectiveness.

[0074] The above description of the advantageous embodiments of the present invention contains many features, which are presented in the individual dependent claims in a way that they are partially combined into multiple features. However, these features can also be considered individually and combined into other meaningful combinations.

[0075] Even if several terms are used in the specification or in the patent claims in the singular or in combination with quantifiers, the scope of the present invention for these terms should not be limited to the singular or the corresponding quantifiers. In addition, the word "a" or "an" is not understood as a quantifier, but an indefinite article.

[0076] The above-described characteristics, features and advantages of the present invention and the methods and means for realizing them will become clearer and easier to understand in conjunction with the following description of an embodiment of the present invention explained in detail in conjunction with one or more figures / illustrations (the same components / parts and functions have the same figure marks in the figures / illustrations).

[0077] These exemplary embodiments serve to illustrate the invention, and the invention is not limited to the feature combinations given therein, nor is it limited in terms of functional features. In addition, the features suitable for each exemplary embodiment can also be viewed clearly separately, removed from the exemplary embodiment, introduced into another exemplary embodiment in order to supplement another exemplary embodiment, and combined with any one of the claims. DETAILED DESCRIPTION

[0078] In the attached picture:

[0079] Figure 1 a. Figure 1 b. Figure 1 c shows a tool chuck, such as a shrink chuck, having an expansion gap and an intermediate sleeve according to an embodiment of the present invention;

[0080] Figure 2 a. Figure 2 b. Figure 2 c shows a tool chuck, such as a heat shrink chuck, having an intermediate sleeve with a chamber according to an embodiment of the present invention;

[0081] Figure 3 a. Figure 3 b. Figure 3 c shows a tool chuck with balls according to an embodiment of the present invention, such as a heat shrink chuck;

[0082] Figure 4 a. Figure 4 b. Figure 4 c shows a tool chuck with rollers according to an embodiment of the present invention, such as a shrink chuck;

[0083] Figure 5 a. Figure 5 b shows a tool chuck, such as a shrink chuck, having a damping chamber according to an embodiment of the present invention, the damping chamber being located in a tool chuck base body and having an elastically supported damping element;

[0084] Figure 6 a. Figure 6 b shows a tool holder, such as a shrink-fit holder, having a thermochemically heat-treated active surface according to an embodiment of the present invention.

[0085] Figures 1 to 6 Different tool holders 1 are shown in each case in different views and details.

[0086] Tool chuck 1 with expansion gap 11 and intermediate sleeves 13, 14 ( Figure 1 a. Figure 1 b. Figure 1 c)

[0087] The tool chuck 1 (here a shrink chuck) has a tool chuck base body 2. The tool chuck base body has a coupling for connecting to a machine tool at its rear end 3. Figure 1 An HSK coupling is exemplified in the figure.

[0088] However, SK couplings or other systems are also conceivable as an alternative. The terms “HSK” and “SK” for the couplings preferably used here are familiar to the person skilled in the art, since they are used in a standardized manner in many places.

[0089] A sleeve portion 4 is formed at a front free end 9 of the tool holder basic body 1 facing away from the coupling.

[0090] A tool receptacle 5 for holding a tool (not shown), such as a tool shank of an end mill, is implemented in the sleeve part 4 .

[0091] The sleeve part 4 forms an outlet region 6 in the axial direction behind the tool shank, ie facing away from the front free end 9, which is not used by the tool shank or for retaining the tool shank. The coolant can be introduced into the sleeve part 4 via the outlet region 6.

[0092] The sleeve part 4 is designed and used in such a way that it can hold the tool shank in a press-fit manner so that the tool shank can neither rotate relative to the tool holder 1 nor be pulled out or slipped off in the axial direction (at least substantially) during operation of the tool.

[0093] The shrinking process used in this respect and the corresponding design of the tool holder as a shrink chuck are described in detail in the German patent applications DE 199 15 412 A1 and DE 10 2021 199 935 A1, which are hereby fully the subject matter of the present disclosure and whose features can therefore be referred to in order to restrict the claims associated with the subject matter of the application, if necessary.

[0094] With regard to its sleeve part 4, the tool chuck 1 differs from the sleeve part of the aforementioned application in that the sleeve part 4 is constructed in two layers (7, 8) and has an intermediate body (13, 14) arranged respectively between the two layers (7, 8). Figure 1 As shown, at least an axial region of the tool receptacle 5 is formed along the sleeve section, and this can usually even be seen up to a region beyond the outlet 6 .

[0095] The sleeve part is constructed in two layers and has an intermediate layer in that the sleeve part consists of an inner sleeve 7 which is connected in one piece to the tool holder base body 2 (in this case, due to the integral nature, only the inner sleeve 7 is connected to the tool holder base body 2 in one piece). Figure 1 In a, an imaginary connection point 17 of the inner sleeve 7 to the tool holder basic body 2 and the outer sleeve 8 as well as two intermediate sleeves 13, 14 arranged one behind the other in the axial direction are indicated.

[0096] A (annular) free space or transition section 12 is formed between the two intermediate sleeves 13, 14 (i.e., the front intermediate sleeve 13 and the rear intermediate sleeve 14), on which the radial distance between the outer sleeve 8 and the inner sleeve 7 is retained, even if the outer sleeve and the inner sleeve are fully assembled and ready for use (see cooling channel 15 below).

[0097] Unlike the inner sleeve 7 which is integrally connected to the tool holder base body 2, the outer sleeve 8 is connected by electron beam welding ( Figure 1 a) is welded (21) to the tool chuck base body 2 in an ideal manner (not shown) such that the flange of the outer sleeve 8 is welded to a complementary mating flange or a complementary annular shoulder of the tool chuck base body 2.

[0098] All components themselves are preferably made of metal or steel, but preferably of different types of steel.

[0099] In one embodiment, the tool holder basic body 2 can also be made of different materials. Thus, the rear end 3 can be made of steel, for example, and the inner sleeve 7, which is formed on the end 3 by additive manufacturing, can be made of another material, such as aluminum.

[0100] At the common joint 22 where the tool holder basic body 2, the inner sleeve 7 and the outer sleeve 8 (only imaginary due to their integration) meet, an expansion gap 11 or undercut 11 is formed (see in particular Figure 1 c) which ideally involves removing material from the tool chuck base body 2, the inner sleeve 7 and the outer sleeve 8 and thereby creating a subtle, noticeable free space (i.e., expansion gap / undercut 11) between the aforementioned components 2, 7, 8 (at their joint 22).

[0101] Although, for example, material removal of the outer sleeve 8 can be carried out on its inner surface (see Figure 1 b. Figure 1 c), but as shown, the material removal of the tool holder basic body 2 can be carried out through the groove 16.

[0102] By means of the expansion gap 11 or undercut 11 on the tool chuck 1 (to be precise here between the tool chuck base body 2, the inner sleeve 7 and the outer sleeve 8), the tool chuck 1 achieves a reduction of stresses, in particular heat-induced (see electron beam welding), and prevention of cracks at the joint 22 between the tool chuck base body 2, the inner sleeve 7 and the outer sleeve 8.

[0103] The inner sleeve 7 and the outer sleeve 8 are connected without clearance via a front intermediate sleeve 13 (i.e., toward the free end 9 or located at the free end 9), in such a way that at least the front intermediate sleeve 8 is in an interference fit with the inner sleeve 7 and the outer sleeve 8, while the rear intermediate sleeve 14 (i.e., toward the end 3 away from the free end 9 or away from the free end) can be in a loose fit with at least one of the inner sleeve 7 and the outer sleeve 8.

[0104] Due to the correspondingly small dimensions of the associated, here cylindrical, active surfaces on the inner sleeve 7 , the outer sleeve 8 and the rear intermediate sleeve 14 , the rear intermediate sleeve 14 can then be pushed onto the inner sleeve 7 when these components are joined.

[0105] The play here usually also exists when the tool holder 1 has not yet clamped any tool holder, but is unused at room temperature and is waiting for its next use.

[0106] However, if the "clamping system" consisting of the inner sleeve 7, the outer sleeve 8 and the front intermediate sleeve 13 located therebetween is stressed due to the interference fit of these sleeves there (on their active surfaces) and is therefore in particular in "close contact", this produces a higher damping friction.

[0107] These press fits can be achieved in particular by virtue of the inner sleeve 7 having a conical outer circumference at least along the main axial length of the tool receptacle 5. The front intermediate sleeve 13 then has a complementary, correspondingly conical inner circumference.

[0108] Then, furthermore, again at least along a major axial length of the tool receptacle 5, the front intermediate sleeve 13 is provided with a tapered outer circumference, and furthermore, the outer sleeve 8 has a complementary, correspondingly tapered inner circumference.

[0109] The taper may be equal for all active surfaces (forming an interference fit), but this is not mandatory. Different tapers may also be achieved, for example by having a front intermediate sleeve 13 with different inner and outer cones (the complementary active surfaces on the inner sleeve 7 and the outer sleeve 8 may then correspond to these cone angles).

[0110] If the front intermediate sleeve 13 is subsequently pushed or pressed onto the inner sleeve 7 in the axial direction and furthermore the outer sleeve 8 is subsequently pushed or pressed onto the front intermediate sleeve 13 , this results in the desired (multiple) pressing.

[0111] This can also be achieved by a contraction operation of the above-mentioned components, in which case a conical active surface would not be necessary and this can be achieved in this case by a correspondingly larger dimension on the active surface (here, for example, cylindrical).

[0112] Furthermore, the tool chuck forms a (coolant) channel route, i.e., via a first cooling channel 15a formed in the inner sleeve from the outlet area 6 to the gap 12 between the inner sleeve 7 and the outer sleeve 8 and thereafter between the intermediate sleeve 14 and the front intermediate sleeve 13, i.e., leading to the transition section 12, and via a second cooling channel 15b formed in the outer sleeve 8 from the gap / transition section 12 to the front free end 9 of the outer sleeve 8, by means of which the coolant is guided to the end side 24 of the tool chuck 1.

[0113] In this case, the two channels 15 a, b are substantially embodied as elongated holes.

[0114] ( Figures 2 to 6 The tool holder 1 shown in FIG. Figure 1 The tool holder 1 is constructed / designed in accordance with the present invention, except for some other / further equally advantageous details, which (only) should be subsequently combined with the corresponding Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 to describe in detail. Figures 2 to 6 For content not mentioned, please refer to Figure 1 (description).

[0115] Tool chuck 1 (having an intermediate sleeve with chambers (27a, b) Figure 2 a. Figure 2 b. Figure 2 c)

[0116] In the tool chuck 1, the front intermediate sleeve 13 and, if applicable, the rear intermediate sleeve 14 shown here each have an internal (annular) chamber 27a or 27b. In this case, the two (annular) chambers 27a, b in the intermediate sleeves 13, 14 are not filled and therefore are respectively provided with free spaces or cavities 28a, b (see also Figure 3 and Figure 4 ).

[0117] The free space / cavity 28 a or 28 b or such a “hollow, annular” chamber 27 a or 27 b contributes in particular to better vibration and damping behavior in the tool holder 1 .

[0118] Tool chuck 1 with ball 19 ( Figure 3 a. Figure 3 b. Figure 3 c)

[0119] The tool holder 1 shown here provides that, instead of the above-described front intermediate sleeve 13 , balls 19 (“three-dimensional ball bodies”) which are held / guided in a ball cage 20 are provided there.

[0120] Here, the ball 19 is also subjected to pressure (from the outer sleeve 8 and the inner sleeve 7), so that the "clamping system" composed of the inner sleeve 7, the outer sleeve 8 and the "ball body" located therebetween is stressed and is thus in particular in "close contact", and this produces a stronger vibration-damping friction.

[0121] Unlike the balls 19, which are arranged here in a press fit, this is not necessarily the case with the cage 20. The cage can be arranged with play between the inner sleeve 7 and the outer sleeve 8. Alternatively, however, the cage 20 can also be press-fitted.

[0122] The ball bodies or balls 19 (distributed in the form of hollow cylinders) also contribute to better vibration and damping behavior in the tool holder.

[0123] Tool chuck with roller 19 ( Figure 4 a. Figure 4 b. Figure 4 c)

[0124] The tool holder 1 shown here (similar to Figure 3 ) proposes that, instead of the above-mentioned front intermediate sleeve 13, there are (cylindrical) rollers 19 (“three-dimensional roller bodies”) which are held / guided in a roller cage 20.

[0125] Here, the roller 19 is also subjected to pressure (from the inner sleeve 7 and the outer sleeve 8), so that the "clamping system" composed of the inner sleeve 7, the outer sleeve 8 and the "roller body" located therebetween is stressed and is thus in particular in "close contact", and this produces a stronger vibration-damping friction.

[0126] Unlike the rollers 19, which are arranged here with a press fit, this is not necessarily the case with the cage 20. The cage can be arranged with play between the inner sleeve 7 and the outer sleeve 8. Alternatively, however, the cage 20 can also achieve a press fit.

[0127] The roller bodies or rollers 19 (distributed in the form of hollow cylinders) also contribute to better vibration and damping behavior in the tool holder 1 .

[0128] Tool chuck 1 having a damping chamber with a resiliently mounted damping element 19 in a tool chuck base body 2 ( Figure 5 a. Figure 5 b)

[0129] The tool clamping chuck 1 is provided with a chamber 29 which is arranged in the tool clamping chuck basic body 2 and which is circumferentially arranged in an annular manner.

[0130] A damping body 19 , which in this case is in the form of a hollow cylinder made of hard rubber, is elastically mounted in the annular space 29 .

[0131] The damping element or damping body influences the vibration behavior and thus the damping behavior of the tool holder 1 in a particularly advantageous manner (because it is improved).

[0132] Tool holder with thermochemically heat-treated active surface 26 ( Figure 6 a. Figure 6 b)

[0133] In the tool chuck 1, the active surface 26 of the "clamping system" composed of the inner sleeve 7 (outside), the outer sleeve 8 (inside) and the front intermediate sleeve 13 (inside and outside) is thermochemically heat treated (in this case by means of a plasma nitriding method or a plasma nitrocarburizing method) in order to give the active surface 26 a higher surface hardness, thereby making it better resistant to friction wear, adhesive wear and corrosive wear.

[0134] Furthermore, the active surface 26 treated in this way can preferably also have a vibration-damping effect.

[0135] Even though all active 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, individual active 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) can also be (thermochemically) treated, thereby correspondingly treating at least one active surface in the corresponding press fit.

[0136] Furthermore, the tool holder 1 is provided here on the outside of the tool holder basic body 2 with different (balancing (threaded)) holes 10 which, if necessary, can be filled with masses, here balancing screws, for balancing purposes.

[0137] Although the details of the present invention have been shown and described in detail by means of a preferred embodiment, the invention is not restricted to the disclosed examples and other variants may be derived therefrom without departing from the scope of protection of the invention.

[0138] All features shown in the drawings may also be essential to the invention individually or in combination or at least advantageous for the invention and can therefore also be claimed for protection individually or in combination (in the claims).

[0139] List of Reference Numerals

[0140] 1 Tool chuck

[0141] 2 Tool chuck base

[0142] 3 Backend

[0143] 4 Sleeve

[0144] 5 Tool holder

[0145] 6. Exit Area

[0146] 7 Inner sleeve

[0147] 8 Outer sleeve

[0148] 9 Free front end

[0149] 10 (Balancing (threaded)) hole with balancing screw

[0150] 11 Extension gap, undercut

[0151] 12 Transition section

[0152] 13 front middle sleeve

[0153] 14 Rear intermediate sleeve

[0154] 15a, b Coolant channel, coolant hole

[0155] 16 (2 in) groove

[0156] 17Connection

[0157] 18 welding parts, connection parts

[0158] 19 Damping body, damping element, ball, roller

[0159] 20(Ball / Roller) Cage

[0160] 21 Welding / brazing connections, electron beam welding

[0161] 22Jointing parts

[0162] 23(8) Material removal mark

[0163] 24 side

[0164] 26 Thermochemical heat treatment areas / active surfaces, coatings

[0165] Chamber 27a, b

[0166] 28a, b Free space / cavity in 27a, b

[0167] 29(2 in) (damping) cavity.

Claims

1. A tool chuck for clamping a tool having a tool shank, the tool chuck having a sleeve portion which is open at its free end and connected to a tool chuck base body towards the free end, the sleeve portion being made of a preferably electrically conductive material, the sleeve portion forming a tool receptacle for fixing the tool shank in a friction fit, in particular by shrinking, in a press fit manner, wherein the sleeve portion is preferably composed of an inner sleeve and an outer sleeve, which is preferably also made of an electrically conductive material, at least over the entire axial length of the tool receptacle, the outer sleeve accommodating the inner sleeve in a ready-to-operate state and engaging with the inner sleeve without play, Features An expansion gap between the tool chuck base, the inner sleeve and the outer sleeve.

2. The tool holder according to at least one of the preceding claims, It is characterized in that In the expansion gap, a recess or groove is formed which provides a free space in the tool holder basic body.

3. A tool chuck for clamping a tool having a tool shank, the tool chuck having a sleeve portion which is open at its free end and connected to the tool chuck base body towards the free end, the sleeve portion being made of a preferably electrically conductive material, the sleeve portion forming a tool receptacle for fixing the tool shank in a friction fit, in particular by shrinking, in a press-fit manner, wherein the sleeve portion is preferably composed of an inner sleeve and an outer sleeve which is preferably also made of an electrically conductive material over at least the entire axial length of the tool receptacle, the outer sleeve accommodating the inner sleeve in a ready-to-run state and engaging with the inner sleeve without play, preferably according to claim 1 or claim 10, Features At least one first intermediate sleeve between the inner sleeve and the outer sleeve.

4. Tool holder according to at least one of the preceding claims, It is 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 holder according to at least one of the preceding claims, Features A second intermediate sleeve between the inner sleeve and the outer sleeve.

6. Tool holder according to at least one of the preceding claims, It is characterized in that The second intermediate sleeve has a loose fit with the inner sleeve and / or the outer sleeve.

7. Tool holder according to at least one of the preceding claims, It is characterized in that The intermediate sleeve arranged between the inner sleeve and the outer sleeve is made of copper-containing material or shape memory material or memory material or carbon fiber material or hard metal material or ceramic material, and / or has Ampco material and / or has a hardness of at least 50HRC; in particular, the intermediate sleeve is harder than the outer sleeve.

8. Tool holder according to at least one of the preceding claims, It is 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 within the intermediate sleeve or the outer sleeve or the inner sleeve.

9. Tool holder according to at least one of the preceding claims, It is characterized in that A damping body, in particular a powder or oil, or in particular or ideally a rolling body, in particular a ball, roller or needle roller, in particular a hard metal or ceramic rolling body, or a (heavy metal or rubber) ring or a (hard metal or rubber) insert, is arranged in at least one chamber and the damping body is preloaded, in particular by a spring, if necessary.

10. A tool chuck for clamping a tool having a tool shank, the tool chuck having a sleeve portion which is open at its free end and connected to the tool chuck base body towards the free end, the sleeve portion being made of a preferably electrically conductive material, the sleeve portion forming a tool receptacle for fixing the tool shank in a friction fit, in particular by shrinking, in a press-fit manner, wherein the sleeve portion is preferably composed of an inner sleeve and an outer sleeve which is preferably also made of an electrically conductive material over at least the entire axial length of the tool receptacle, the outer sleeve accommodating the inner sleeve in a ready-to-run state and engaging with the inner sleeve without play, preferably according to claim 1 or claim 3, It is characterized in that In particular, on the inner circumference of the outer sleeve or the outer circumference of the inner sleeve, or on the inner circumference and / or outer circumference of at least one first intermediate sleeve arranged between the inner sleeve and the outer sleeve, the active surface of at least one of the components joined to each other in the sleeve portion is thermochemically heat treated and / or coated; or the active surface of at least one of the components joined to each other in the sleeve portion, in particular, on the inner circumference of the outer sleeve or the outer circumference of the inner sleeve, or on the inner circumference and / or outer circumference of at least one intermediate sleeve arranged between the inner sleeve and the outer sleeve or the first intermediate sleeve, is sprayed with a hard material or alloy or has been sprayed with them.

11. Tool holder according to at least one of the preceding claims, It is characterized in that The thermochemical heat treatment is nitriding with diffusion of nitrogen, such as plasma, vacuum or gas nitriding, or nitriding with diffusion of nitrogen and carbon, such as gas, plasma or salt bath nitrocarburizing.

12. Tool holder according to at least one of the preceding claims, It is characterized in that The outer sleeve is welded or brazed to the tool holder basic body, ideally in that a collar of the outer sleeve is welded or brazed to a complementary mating collar or a complementary annular shoulder of the tool holder basic body, in particular by electron beam welding.

13. Tool holder according to at least one of the preceding claims, It is characterized in that At least one cavity is arranged between the inner sleeve and the outer sleeve and / or in the inner sleeve and / or the outer sleeve, in which a damping body, in particular powder or oil, in particular hydraulic oil, or ideally rolling bodies, in particular balls or needles, in particular hard metal or ceramic rolling bodies, or (heavy metal or rubber) rings or (hard metal or rubber) inserts held in a cage (in particular a metal or plastic cage) are arranged, and the damping body is preloaded, if necessary, in particular by a spring.

14. Tool holder according to at least one of the preceding claims, It is characterized in that The at least one cavity is flushed with a fluid, in particular water, or with a gas.

15. Tool holder according to at least one of the preceding claims, Features A chamber in the tool chuck base body in which an object is arranged, in particular a powder or 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 a (heavy metal or rubber) ring or a (hard metal or rubber) insert, which is preloaded, if necessary, in particular by a spring.

16. Tool holder according to at least one of the preceding claims, It is characterized in that Even if the tool chuck has room temperature and does not clamp any tool shank, the outer sleeve and the inner sleeve or the at least one intermediate sleeve and the inner sleeve and the outer sleeve are connected to each other by a press fit.

17. Tool holder according to at least one of the preceding claims, It is characterized in that The outer sleeve is designed such that after its thermal expansion and after the tool shank to be clamped as intended has been inserted into the inner sleeve, it is prevented from shrinking when cooling again and thus contributes greatly to producing the press fit which holds the tool shank therein.

18. Tool holder according to at least one of the preceding claims, It is characterized in that The inner sleeve is designed so that it is stressed in a cold state and opens due to stress relief when the outer sleeve thermally expands.

19. Tool holder according to at least one of the preceding claims, It is characterized 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, for example steel in the form of hardened, in particular surface-hardened and therefore preferably wear-resistant steel for the inner sleeve and steel in the form of hot working tool steel for the outer sleeve.

20. The tool holder according to at least one of the preceding claims, It is characterized in that The inner sleeve is an inseparable, preferably integral component of the tool chuck base body, which in particular also forms a coupling for a machine tool, preferably in the form of a cylindrical coupling or as a short taper coupling or a polygonal taper coupling or a KM4X or HSK coupling, if necessary as a regionally restricted variant MAS-BT (in Asia), ISO / DIN (in Europe) and CAT-V (in America).

21. The tool holder according to at least one of the preceding claims, It is characterized in that The inner sleeve has a cylindrical or conical outer circumference and the outer sleeve has a complementary cylindrical or conical inner circumference, or the inner sleeve has a cylindrical or conical outer circumference and the at least one first intermediate sleeve has a complementary cylindrical or conical inner circumference, or the at least one first intermediate sleeve has a cylindrical or conical outer circumference and the outer sleeve has a complementary cylindrical or conical inner circumference; and / or 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 each other by extrusion, wherein, especially when the circumference of the sleeve is implemented as a cylinder, the inner circumference of the outer sleeve has a smaller diameter relative to the outer circumference of the inner sleeve or relative to the outer circumference of the at least one first intermediate sleeve, or the inner circumference of the at least one first intermediate sleeve has a smaller diameter relative to the outer circumference of the inner sleeve.

22. Tool holder according to at least one of the preceding claims, It is characterized in that The sleeve part preferably forms the centering region completely, substantially or to a large extent in an outer region of the axial extension of the tool receptacle. In this way, the inner sleeve has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, and when the inner sleeve and the outer sleeve are pressed against each other, the centering area forms a guide area in the axial direction, in which the inner sleeve and the outer sleeve come into contact with each other for the first time and are not brought into appreciable pressure against each other there, and in particular only during the further pushing toward each other a pressure is brought into place outside the guide area; or In this way, the inner sleeve has an enlarged outer diameter and the intermediate sleeve, in particular the second intermediate sleeve, has a complementary inner diameter, and when the inner sleeve and the intermediate sleeve, in particular the second intermediate sleeve, are pressed against each other, the centering region forms a guide region in the axial direction, in which the inner sleeve and the intermediate sleeve, in particular the second intermediate sleeve, come into contact with each other for the first time and are not brought into appreciable pressure against each other there, and in particular pressure is only produced outside the guide region during further pushing towards each other; or The method is that the intermediate sleeve, in particular the second intermediate sleeve, has an enlarged outer diameter and the outer sleeve has a complementary inner diameter, and when the intermediate sleeve, in particular the second intermediate sleeve and the outer sleeve are pressed against each other, the centering area forms a guide area in the axial direction, in which the intermediate sleeve, in particular the second intermediate sleeve and the outer sleeve come into contact with each other for the first time and are not subjected to any significant pressure on each other at this point, and in particular pressure is only produced outside the guide area during further pushing towards each other.

23. Tool holder according to at least one of the preceding claims, It is characterized in that The guide or centering region transitions via a preferably conical transition section into a section of the sleeve part assigned to the tool receptacle, wherein in particular in the region of the preferably conical transition section the active surfaces of the sleeve do not come into contact with one another.

24. Tool holder according to at least one of the preceding claims, It is characterized in that The outer sleeve preferably forms a flange with a through hole in front of its possible guiding area in the pushing direction, and a complementary flange or a complementary annular shoulder with a nut threaded hole or a freely protruding column bolt faces the flange, and the complementary flange or the complementary annular shoulder is formed by the tool chuck base body, and is preferably formed in such a way that the outer sleeve can be pressed onto the inner sleeve by means of a clamping screw through screwing with the tool chuck base body under ideal conditions, wherein an extrusion device is preferably provided for extruding the outer sleeve again.

25. Tool holder according to at least one of the preceding claims, Features A coolant channel, which preferably opens out at the free end of the sleeve portion so as to output coolant to the tool via its opening there, wherein the at least one coolant channel is preferably primarily composed of a circumferentially closed hole passing through the outer sleeve and / or secondarily composed of a circumferentially closed hole passing through the inner sleeve.

26. Tool holder according to at least one of the preceding claims, Features: An expansion gap between the tool chuck base, the inner sleeve and the outer sleeve; and 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, wherein the first intermediate sleeve is arranged between the inner sleeve and the outer sleeve with an interference fit, and the first intermediate sleeve and the second intermediate sleeve are arranged axially spaced apart from each other in such a way that the first intermediate sleeve is arranged behind the second intermediate sleeve in the direction toward the freely open end; and active surfaces of at least one of the components joined to each other that have been subjected to thermochemical heat treatment, in particular plasma or gas nitriding, in particular the inner periphery of the outer sleeve or the outer periphery of the inner sleeve or the inner periphery and / or outer periphery of at least one of the intermediate sleeves are subjected to the above-mentioned treatment.

27. The tool chuck according to one of the preceding claims is used for high-speed cutting, in particular for high-speed milling (HSC) or CAD / CAM optimized trochoidal milling, or for high-performance milling (HPC), preferably, high-speed cutting and high-speed milling are both carried out at a cutting speed greater than 800m / min, more preferably greater than 1,100m / min.

28. A tool clamping system comprising at least one tool chuck according to one of the preceding claims and a shank-type tool which is matched to the tool chuck with respect to the nominal shank diameter of the tool chuck.

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