DE102004019869A1 - Lathe tool holder has an axial tensioning assembly exerting a tensioning force and dampener acting on the tool - Google Patents

Abstract

A lathe tool holder (10) rotates about an axis (D) and has a spindle (18) terminating in clamping jaws (14) about a central concentric opening (16). The tool holder is retained in the lathe spindle by a press-fit interface. The tool further has an axial tensioning assembly (20) exerting a tensioning force (Vk) acting on the tool.

Description

The The present invention relates to a tool holder for a a rotary axis rotatable tool, in particular drilling, milling, friction or grinding tool, wherein the tool holder a clamping shaft comprising, which at its one end-side shaft portion a Clamping training for holding the tool and at its other end Shank region a coupling formation for coupling with a machine tool having.

such Tool holders are, for example, as chucks or mandrels for drilling, milling, friction or grinding machines, i. in general for machines for cutting Machining with rotating geometrically determined or indefinite cutting edges, well known. The clamping training can be a centric to the axis of rotation receiving opening for receiving a holding shaft of the tool, wherein the Circumferential casing of the receiving opening at least one clamping surface can be provided for holding a retaining shaft of the tool. The known tool holder usually have a certain axial Length up, what they basically susceptible for strangers Makes vibrations, which can be excited by many sources.

For example have numerous cutting tools, which for clamping in a such tool holder are provided on its outer surface at least a cutting edge or over their extent evenly distributed a plurality of cutting edges, so that during a tool rotation periodically at least one cutting edge enters the workpiece body, to stand out from this one chip. With such a cutting entry in the material is a force reaction connected to the cutting edge, as these more or less abruptly from a non-cutting to a cutting state. The periodicity of such power surges depends of the number of existing blades and the number of revolutions of the Tool and thus the tool holder from. There are, however other vibration influences Known, for example, by one for a particular tool unadjusted Cutting speed can be obtained, for example by rattling a router.

By these influences The tool holder can cause torsional vibrations about its ideal axis of rotation or / and transversal vibrations in a axis containing the axis of rotation Level be stimulated. Also mixed forms of such vibrations are conceivable.

It is therefore an object of the present invention, a tool holder specify the type mentioned, which is generally compared to the state less prone to technology for one undesirable Vibration excitation is associated with higher machining accuracies reached.

The Object of the present invention is achieved by a tool holder of the aforementioned type, which has a tensioning arrangement, at least during operation of the tool holder in an axial Tension portion forming axial portion of the clamping shaft a tensioning force with a tensioning component acting in the axial direction exercises.

According to the present Invention can be the tensioning force in any direction exercised on the tool holder as long as they are in the axial direction, i. in the direction of Has axis of rotation, acting tension component. It will However, it should be understood by those skilled in the art that with a tensioning arrangement according to the invention achievable effect is greater, the bigger the Proportion of the tensioning component acting in the axial direction at the total tension force is.

at The coupling training can be any type of conventional Tool holder coupling, such as a steep taper coupling shaft or a hollow shaft coupling (HSK coupling) act. It can also be in the clamping training also to be any type of tool clamping device, such as e.g. a Shrink feed intake, a tool holder for a cylindrical shank with a clamping screw, for example, the Weldon type or Whistle-Notch type. Also suitable are collet chucks or so-called combi shots or knife head shots.

The axial tension component causes in the axial tension section a mechanical axial stress, which changes the spring characteristics of the tool holder, in particular its spring hardness in the axial section and thus the tool holder as a whole relative to the mechanically unstressed state. By applying the axial stress, the spring rigidity of the tool holder as a whole and, associated therewith, the oscillation forms, which can be excited particularly easily on the tool holder, and their associated resonance frequencies can be purposefully changed. As is well known, the resonant frequency of a component, such as a tool holder, is determined from the square root of the quotient of spring stiffness and mass. By deliberately changing the spring stiffness, both the Torsional vibration behavior, ie regarding a vibration of the tool holder about an axis of rotation, as well as the transversal vibration behavior, ie a vibration of the tool holder in a plane containing the axis of rotation with a vibration deflection of the tool holder orthogonal to the axis of rotation regarding, are selectively influenced.

The mechanical axial stress acting on the tool holder through the Tensioning arrangement is applied, a tensile stress or a Be compressive stress.

If predicated is that the bracing arrangement at least during operation of the tool holder on the tool holder a tensioning force exerts so should not be ruled out that this tension is exercised by the tensioning arrangement in non-operational states. It should only be ensured that the tension then, if the risk of unwanted vibration excitation exists, namely During operation, the tensioning force acts on the tool holder. With "Operation" is the rotating Tool holder referred to, in which an intervention in him clamped tool takes place in a workpiece, imminent or at any time.

For as possible evenly over the entire circumference of the tool holder on this acting tensile force the tensioning arrangement can advantageously be coaxial with the tensioning section be arranged of the tool holder. A simple one can Tension arrangement with respect to be checked on their correct fit, when coaxially surrounding the toolholder, especially when the Tensioning arrangement designed as the clamping shaft enclosing sleeve is.

The Bracing arrangement can be designed in a structurally simple manner Way the tensioning force over two in the axial direction spaced support points in the tool holder initiate. The between the support points located axial portion of the tool holder is then the above-mentioned axial Bracing section. Generally, the axial strain section the section in which the tensioning force on the tool holder acts.

Basically enough it off, if only one of the support points on the tool holder itself is provided. For example, a support point on a permanently connected to the tool holder part, such as a be provided therein clamped tool. This case will continue below in detail described. Advantageously, because of the design of more Parts independently, However, both are support points provided on the tool holder.

As well can basically be thought of the tensioning arrangement once in the production the tool holder to attach to them such that they have a desired Tension on this exercises, or the tensioning arrangement on the tool holder in a predetermined Anbringungsstellung to make attachable, in which they a predetermined Tensioning force on the tool holder exerts. As advantageous, however considered to form the tool holder in such a way that on him acting tensioning force is changeable. Then, depending on the application, the tensing force should be chosen so that in the particular application, i. considering the number of blades present on a cutting tool, the speed the tool holder, etc., an undesirable vibration excitation not or at least to a lesser extent occurs.

According to one first constructive design The tool holder can thereby change the acting on him Tensioning be formed so that it is designed in several parts, wherein at least two tool holder parts in the axial direction relative are mutually displaceable and wherein two tool holder parts each a support point exhibit. In this embodiment can the axial distance between two support points from each other Relocation of at least two tool holder parts relative to each other can be achieved in the axial direction. In this way you can between the two interpolation points braced a tensioning arrangement of predetermined axial dimension become.

Especially simply the displaceability of at least two tool holder parts be achieved when they are parallel to each other along a plane parallel to the axis of rotation Screw axis can be screwed. As a screw axis is the one Axis understood, longitudinal which is achieved by rotation of one of the parts a propulsion. It is express noted that also more than two tool holder parts can be provided it is sufficient if in each case a support point at two of these is provided.

In addition or as an alternative to the embodiment just described, at least one of the support points can be designed for the axial displacement of the section of the bracing arrangement supported on it. If one of the support points defines a portion of the tensioning arrangement supported on it in the axial direction and the other support point allows an axial displacement of the portion of the tensioning arrangement supported on it, this can then be achieved between the support parts len lying axial section are selectively set under tensile or compressive stress. The amount of tension in the bracing section is preferably variable. The bracing of the tensioning section is also possible if both support points are designed for the axial displacement of the sections of the bracing arrangement supported on it.

The Relocation of a portion of the bracing assembly to a support point can be realized in various ways, such as through a slide track on one of the components: tool holder and bracing arrangement, and one of them Projection on the other component. A particularly simple attachment of Tensioning arrangement and a particularly simple displaceability at a support point supported Section of the tensioning arrangement can be obtained thereby that the wengistens a support point a thread with which the supported on the support point section the tensioning arrangement is displaceable in the axial direction.

At This thread can for example attack an adjusting nut, which displaced by rotational movement in the axial direction on the tool holder is, which in turn causes a tension of the tool holder the bracing arrangement can be reached.

A Particularly low number of components of a tool holder according to the invention is achieved when the thread provided on a peripheral surface of the tool holder is, wherein it with a mating thread on a peripheral surface of the Clamping arrangement is engaged or engageable is. Preferably, the peripheral surface of the Tool holder around an outer peripheral surface and at the peripheral surface the tensioning arrangement about an inner circumferential surface, so that the tensioning arrangement simply from the outside can be screwed onto the tool holder. This offers a always good accessibility the tensioning arrangement and thus easy adjustability the tension applied by it to the tool holder.

It However, it may also be thought to the tensioning in the To arrange tool holder so that it surrounds the tensioning arrangement. This solution is advantageous if a particularly small outer diameter of the tool holder required becomes. Then, the previously designated peripheral surface of the tool holder a Inner circumferential surface his and the peripheral surface the tensioning arrangement an outer peripheral surface. The Clamping arrangement can then easily into a recess of the tool holder be screwed in and there with the other support point forming stop in plant.

It However, it can also be thought that the tool holder at least a separate actuator, which on one of the components: Tool holder and bracing assembly, is supported and with each transferring other component force is engaged. By this actuator can then, for example with tool attack, the respective tensioning force can be adjusted. For as possible size Tensioning force can also several actuators over be provided distributed over the circumference of the tool holder, so that each one must carry only a fraction of the total load.

The separate actuator may in turn be designed such that the force transmitting intervention is realized by a thread, wherein preferably at least a separate actuator is a screw or a nut. One Thread represents the simplest and easiest to manufacture means for one Force transmitting Intervention with adjustable amount of force. By appropriate choice The thread pitch may be a finer or coarser adjustability the tensioning force can be provided.

to easy transmission a pointing in the axial direction tensioning component can at least one of the interpolation points from a circumferential surface section pointing at least also in the axial direction be formed, with which a mating surface portion of the tensioning arrangement is in investment engagement or can be brought into investment engagement is. Such peripheral surface sections are particularly easy to produce on the tool holder, such as through Turning. This turning process is particularly easy carry out, if it is an outer circumferential surface portion is. For example, the circumferential surface section facing in the axial direction formed on a circumferential on the tool holder in the circumferential collar be. Also protruding from the tool holder in the radial direction Circumferential segments can said peripheral surface portions exhibit. As pointing in the axial direction becomes a peripheral surface portion according to the present Login then viewed when its surface normal one in axial Direction extending normal component has. It will be professionals be obvious that one at least also in the axial direction facing peripheral surface section then the better for transmission a tensioning component acting in the axial direction is suitable, the larger the Proportion of the axial component of the surface normal to the overall standard is. Therefore, the circumferential surface section is particularly preferably orthogonal to Oriented axis of rotation.

Of the Tool holder has at its other, the end area with clamping training opposite axial end a coupling formation for Coupling with a machine tool on. To the functional training: Not to disturb clamping training and coupling training is the bracing section in the axial direction preferably between tension training and tying training.

This But it does not have to be that way. Instead of the previously described rotating Federal can the tensioning arrangement for the transmission of the in the axial direction acting tension component according to an embodiment of the present invention also on an end face of the tool holder, preferably on the tension education side face, attack. The coupling formation side end face is less suitable, since here collisions with the tool holder clamping machine tool may occur.

According to one another embodiment A development of the present invention can be used to reduce the manufacturing cost of the tool holder when the clamping training a in terms of the axis of rotation conical peripheral surface portion has what often the case is when the clamping surfaces the clamping training by screwing on a union nut or by a Clamping training surrounding clamping sleeve be tense, the conical peripheral surface portion than the previously mentioned used at least also in the axial direction facing peripheral surface portion become. In this case, there is the mating surface portion of the tensioning arrangement in abutting engagement with the conical peripheral surface portion or in abutting engagement Can be brought with this. According to one advantageous embodiment of the present invention may also It should be remembered that the aforementioned clamping sleeve or union nut the tension training forms.

For as possible uniform force transmission over the Entire circumference of the tool holder includes the tensioning arrangement preferably a sleeve with at least in an axial section closed cross-section. It is sufficient if the sleeve at least in an axial section a closed cross-section includes, since this for provides a force compensation in the circumferential direction. Preferably lies the closed cross-section in the area of the support points, so that along the entire Circumference of the tool holder at the support points a power transmission between bracing assembly and tool holder with relatively less distributed load can take place.

The Sleeve can for vibration damping a Plural of coaxially arranged on the tool holder, at least in An axial section abutting sleeve shells comprise. At a twist of the tool holder, the coaxial sleeve coats twist differently strong, so that there is a relative movement between them can, which between the adjoining sleeve coats friction generated. The resulting friction has a dampening effect on it undesirable Move.

to Avoiding collisions with a workpiece to be machined the sleeve, if it surrounds the tool holder radially on the outside, be designed in such a way that it has a larger diameter at the coupling formation closer clamping point as at the spinal training closer Support point. It is preferred for reasons a simple manufacture conical.

A good centering of at least one sleeve sheath or the entire Sleeve becomes achieved if at least one sleeve sheath, preferably the entire sleeve, at least one axial end region, preferably at both axial End regions, with an annular collar formed on the tool holder form-fitting is engaged.

Farther the at least one sleeve jacket, preferably the entire sleeve, at least one axial end region, preferably at both axial End regions, with the interposition of a damping piece abut the tool holder. By the investment intervention is again a micro-relative movement between sleeve and damping piece and / or between damper and tool holder allows so that unwanted Relative movements between the tool holder and sleeve are damped. This also prevents the emergence of an undesirable Vibration. About that In addition, the damping piece ensures that beating damped on the tool holder be how they can come from a machining workpiece machining. This is not synonymous with an over a mere one Concerning compound connection of sleeve and damping piece and / or of damping piece and tool holder.

According to the just mentioned, the sleeve can be firmly clamped to the tool holder only in the axial direction for frictional damping, so that a rotation of the sleeve is allowed relative to the tool holder about its axis of rotation. However, a high rigidity, which is advantageous for precise machining, can be obtained by at least one sleeve jacket, preferably the entire sleeve, being firmly connected to the tool holder at at least one axial end region, for example by soldering, welding, gluing or comparable joining methods for permanent bonding dung. The rigidity can be further increased if at least one sleeve jacket, preferably the entire sleeve, is firmly connected to the tool holder at both axial end regions.

The previously explained Further developments of the present invention are suitable for permanent use an acting in the axial direction of the tensioning component to exercise the tool holder.

alternative or additionally However, the tool holder may be configured such that at least a sleeve coat, preferably the entire sleeve, defines a closed volume with the tool holder, such as a chamber, which with a flowable material, preferably one Liquid, and / or with an elastic material, preferably a rubbery one Material filled or fillable is. The material is in the closed volume by centrifugal forces during the Operating the tool holder displaced radially outward, where there is an after directed radially outward Force on the space volume outwardly bounding wall exerts. These from the rotating liquid practiced Centrifugal force leads with a suitable design of the radially outwardly bounding wall of the Cavity to force acting in the axial direction force components at the junction the wall with the tool holder.

Even in a cylindrical or circular cylindrical wall are through Material deformation at high speeds in the axial direction acting force components effective.

Out establish a simple manufacturing is the the completed volume of space radially outward limiting wall through a sleeve jacket or through the entire Sleeve formed. The sleeve surrounds the bracing section radially outward, since the centrifugal force at a predetermined speed, the higher the higher Diameter of the sleeve is. However, it is sufficient if the sleeve only in an axial Section, for example in the area of the coupling-closer support point, a big Diameter.

Farther the tool holder can pressure change means Include the pressure of the flowable material to be able to change in the closed room volume. This can be independent of a speed of the tool holder set a desired bias become. In general, the flowable material, which in the Room volume filled or fillable is to be a non-compressible liquid. Then you can Pressure changing means simply be formed by having means of change of the volume of space, for example at least one in the volume of the room displaceable adjusting screw and / or at least one displaceable Piston. Here, the pressure can be changed as in a piston-cylinder system shift the adjusting screw and / or the piston into the closed position Room volume into or out of this. Since here only short travel paths needed can be at least one seal as the at least one piston be used so that separate to be provided seals can.

As already mentioned above, it is sufficient if a support point is provided on the tool holder. The other support point for transmission a tensioning component acting in the axial direction can on a tool clamped in the tool holder or clamped be provided. In this case, the tool holder is without it clamped tool always relieved. When clamping the tool is then exerted by this a force on the tool holder. These Construction is particularly suitable for axial tension in to generate the bracing section, as a longitudinal end of the bracing arrangement, about the sleeve, on a surface supported on the tool can and then the bracing portion of the tool holder under Tension can be set.

These Effect can be achieved by a tool holder, in which the aforementioned actuator a clamped in the tool holder or clamping tool, with which an axial end portion transmitting force to the tensioning arrangement in investment engagement or in investment engagement can be brought, wherein the Tool, preferably by a clamping thread, in the axial direction is displaceable on the tool holder.

The previously described tension arrangement changes the spring characteristic of the tension shaft exposed during operation both torsional vibrations and bending vibrations and thus its vibration behavior. In individual cases, even the change in the vibration behavior can lead to an improvement in the cutting properties of the tool and thus to an improvement in its service life during operation. However, a substantial improvement in the damping properties of the tool holder can be achieved if energy absorbing or energy-consuming means are assigned to the clamping shaft. In a preferred embodiment of the invention, it is provided that the sleeve which generates the preload force rests on the periphery of the clamping shaft in a frictional engagement, at least over a partial region of its axial length. The only connected at its axial ends with the tool holder sleeve moves relative to torsional or bending oscillations of the clamping shaft to this and dampens by their frictional engagement these vibrations. The frictional engagement can be realized by an oversize design of the abutting peripheral surfaces of the clamping shaft on the one hand and the sleeve on the other hand, for example, in an embodiment in which the sleeve surrounds the clamping shaft by a radial excess of the outer diameter of the clamping shaft relative to the inner diameter of the sleeve. However, the radial forces required for the frictional engagement can also be generated elsewhere, for example by pressing elastic material between the radially opposite peripheral surfaces of the clamping shaft on the one hand and the sleeve on the other hand.

It has been found that the frictional engagement section does not have the total axial length the sleeve must extend, that it is sufficient, the friction on one Partial section of the sleeve, especially in the area of one of its axial ends, so that the remaining axial length of the sleeve is utilized for the resilient axial clamping can be. In a preferred, structurally particularly simple embodiment is the latter principle at the same time for the axial support of the Sleeve on exploited the clamping shaft. The with its two ends axially biased sleeve supported on the tool holder with her the clamping formation axially near end preferably in one Frictionally engaged friction fit in the press fit frictionally held on the clamping shaft. The axial length of the frictional engagement portion is dimensioned so that it also the axial Preload force of the sleeve can absorb, but towards the other end of the sleeve its friction-damping properties can unfold.

at the mounting of the sleeve on the clamping shaft of the tool holder, the sleeve for Example in a pressing device overcoming the interference fit preloaded on pressure. To the sleeve no over the entire axial height of the frictional engagement section under press-fit conditions to have to, have the sleeve and the clamping shaft at least in a part of the frictionally engaging portion matched slightly conical Shape, for example, at a slope of about 0.1. Such Cone shape is self-locking. It is understood, however, that the frictional engagement section for themselves, but even if it meets Presssitzbedingungen, be formed by cylindrical surfaces can.

With supports their other end the thus under pressure bias on the tension shaft mounted sleeve on an annular shoulder of the Tool holder, in particular on an annular shoulder of the coupling training axially. In this context, it has proved expedient the end supported on the annular shoulder the sleeve to form as a cone section, away from the ring shoulder axially tapered and so in addition for one Stiffening of the coupling training adjacent foot of the Spannschafts ensures.

As already mentioned extends the axially preloaded on pressure sleeve expediently axially between the Reibschlussabschnitt and the axially facing the coupling formation, supported on the tool holder another end at a radial distance from the clamping shaft to the sleeve in her to make the bias generating section movable. axial between the frictional engagement portion and the other supported on the toolholder End can be at least one damping ring of an elastically compressible material between the periphery be arranged the clamping shaft and the inner shell of the sleeve, so that too this area of the pod be exploited for energy-absorbing vibration damping with can. For example, such a damping ring in the above mentioned Cone section of the sleeve be housed.

In Another preferred embodiment provides that the Tensile tensile axial ends of the sleeve and tightly connected to the tool holder, in particular friction welded, the sleeve surrounds the clamping shaft with a radial distance, so that between the sleeve and the clamping shaft one outwards sealed annular chamber is formed. For the axial tension is in this chamber under pressure a deformable and in deformation Vibrational energy absorbing material introduced, for example injected, which at least during the filling process flowable or is deformable and then maintaining its pressure Consistency changes. Suitable, for example, flowable rubber compounds that are in vulcanising the annular chamber or curable plastic substances, harden in the ring chamber to a stiff-elastic ring body. Suitable are also in the annular chamber sinterable materials, such as Ceramic materials. The above-described damping materials may fillers contain the mechanical strength or stiffness of the damping material increase.

In a further variant, which is based on the principle of hydraulic pressure generation for the axial clamping of the tensioning arrangement, it is provided that the sleeve is axially supported at both ends on the tool holder, wherein in Abstützweg one of the two ends of the sleeve a relative to the tool holder axially movable support means is arranged, which has at least one support piston, in an associated with him, a flowable or plastically deformable pressure medium containing pressure chamber is guided axially displaceable, wherein the pressure chamber is associated with an adjustment for changing the pressure in the pressure medium. The pressure chamber is preferably located on the side of the coupling formation of the tool holder for space requirements, and may comprise a plurality of circumferentially distributed, axially movable piston, which distributed on the circumference of the adjacent end of the sleeve act. The pistons are expediently arranged in separate, but communicating for the pressure medium pressure chambers. Preferably, however, the support piston is an annular piston which is centric to the axis of rotation and which is axially displaceable in an annular space forming the pressure chamber. The annular piston may be separate from the sleeve; but he can also be one-piece connected with her.

at The pressure medium may be hydraulic oil or not compressible liquid act. Also suitable are flowable, plastic materials, such as rubbery or flowable plastics or visco-elastic Masses.

at The adjusting element may be a force acting on the printing medium Piston screw or the like act.

The another of the two ends of the sleeve can be firmly connected to the clamping shank, for example, welded or be glued on. Preferably, however, is on the annular collar for the support of the other end of the sleeve a solvable provided on the clamping shaft held circlip. In which Circlip can be a screwed onto the clamping shaft Nut or around a radially elastic in an annular groove of the clamping shaft Snap snapped spring ring.

It is understood that by a suitable choice of the wall thickness of the Sleeve whose Spring properties can be optimized. Also by suitable Shape of the sleeve can the spring properties are influenced. For example, the Sleeve one comprising axially resilient corrugated spring portion.

to Reduction of undesirable occurring Vibrations may be provided on the tool holder a vibrating mass piece, which by destructive resonance an undesirable vibration on the tool holder reduces or even extinguishes. Preferably, the oscillating mass piece in the axial direction on the tool holder is displaceable arranged so that its resonant frequency to the resonant frequency the tool holder is tunable. The oscillating mass piece is preferred provided on the shank of the tool holder, since this is the undesirable Forming vibration modes preferred. In addition, the vibrating mass piece through the previously mentioned Sleeve encapsulated be, if it surrounds the shaft radially outward. As a result, the vibrating mass piece of external influences, such as swarf and coolants, protected. The present invention is described below with reference to drawings be explained in more detail. For a tool holder with oscillating mass piece becomes more independent Protection sought.

In the 1 to 29 Embodiments of the present invention are illustrated.

In 1 is a first embodiment of a tool holder according to the invention generally with 10 designated. The tool holder 10 indicates his in 1 left end a coupling training 12 for coupling the tool holder 10 with a machine tool, not shown, in a conventional manner. By coupled with the machine tool coupling training 12 finds a torque transfer from the rotary drive of the machine tool to the tool holder 10 instead of.

At his coupling education 12 opposite longitudinal end, the tool holder 10 a tension training 14 on, which in the example shown cylindrical clamping recess 16 has, in which a shank of a tool can be inserted and tightened there. In the in 1 example shown is a tool holder 10 for shrinking. The clamping training 14 will do so on its outer peripheral surface 14a in the area of the clamping recess 16 heated, so that the clamping formation thermally expands and the diameter of the clamping recess 16 gets bigger. In this heated state, the shank of a tool is in the clamping space 16 introduced, whereupon the tool holder 10 cools in the area of the clamping training or can be cooled, so that between tool shank and the clamping training 14 due to the cooling-related shrinkage of the clamping formation 14 the tool holder with press fit in the clamping recess 16 is fixed. Such tool holders are well known in the art.

The tool holder 10 is rotatable about a rotation axis D and, moreover, is substantially symmetrical with respect to this rotation axis D. All directions in this application, which relate to an axis are related to the axis of rotation D. This applies to an axial direction, a circumferential direction and a radial direction.

In one between the coupling training 12 and the tension training 14 located axial shaft portion 18 is the tool holder 10 from a sleeve 20 surrounded coaxially. The sleeve 20 is at two spaced apart in the axial direction of support points 22 and 24 on the tool holder 10 supported. The support point 22 in 1 is the coupling training 12 closer support point, while the support point 24 the tension training 14 closer. The Stüttstellen 22 and 24 run around the tool holder 10 around. At her in 1 right longitudinal end 26 has the sleeve 20 a circumferential radial projection 28 on which of the sleeve body 20a projects radially inward.

This radial projection 28 is along the circumference of the tool holder 10 in abutting engagement with one on the tool holder 10 circumferential shoulder or waistband 30 , which starting from the substantially cylindrical shaft surface 18a protrudes radially outward. More specifically, a substantially orthogonal to the axis of rotation D oriented, in the mounted state of the sleeve 20 for coupling training 12 indicative contact surface 28a of the radial projection 28 the sleeve 20 at a likewise substantially orthogonal to the rotation axis D, for clamping formation 14 indicative face 30a of the circulating federal government 30 at. About this contact of the surfaces 28a and 30a is at the support point 24 one acting in the axial direction and for coupling training 12 directed tensioning force VK on the tool holder 10 transferable.

At his coupling education 12 closer longitudinal end 32 has the sleeve 20 a radially outwardly extending radial flange 34 on. The radial flange 34 is in the circumferential direction with a plurality of equiangularly spaced through holes 36 Mistake. Through these through holes 36 are screws 38 passed, the screw head on a substantially orthogonal to the axis of rotation D and the other longitudinal end 26 indicative bearing surface 34c of the radial flange 34 rests.

The screws 38 are in the through holes 36 associated blind holes 40 with internal thread in the tool holder 10 screwed.

By tightening the screws 38 as well as by its support on the radial flange 34 the sleeve 20 is at the support point 22 over the internal thread of the blind holes 40 an acting in the axial direction and for clamping training 14 directed tensioning force VK transferable. By selecting the tightening torque of the screws 38 The amount of the tensioning force VK can be adjusted. For this purpose, a gap between the axis of rotation D substantially orthogonal and clamping formation 14 indicative bearing surface 12a and to the rotation axis D also orthogonal and coupling formation 12 indicative face 34a of the radial flange 34 the sleeve 20 be left.

However, according to an embodiment of the invention, two abutment surfaces may be provided on the tool holder such that the axial distance between them is greater than an axial distance between abutment surfaces of the sleeve associated with the abutment surfaces when viewing the unmounted state of the sleeve. In the example of 1 is the axial distance between the contact surfaces 30a and 12a about 0.3 to 0.5 millimeters larger than the distance of the counter-bearing surfaces 28a respectively. 34a , The screws 38 are then simply tightened until the surfaces 12a and 34a abut each other. Due to the thus achieved material expansion of the sleeve, a predetermined tightening force is exerted on the tensioning portion VA.

The above described at the support point 24 occurring tensioning force VK is a bearing reaction force by tightening the screws 38 caused tensioning force VK, whereby the tension forces occurring at the respective support points VK are equal in magnitude and oppositely directed. This is the between the support points 22 and 24 set tension section VA set under an increased axial compressive stress. The increased axial compressive stress acting in the bracing section VA is higher than an axial stress load in the axial sections of the tool holder adjacent to the bracing section in the axial direction 10 , By this section VA increased axial compressive stress is the spring stiffness of the tool holder 10 changed in relation to an unstrained condition, so that also on the tool holder 10 particularly easy excitable vibration modes and the associated resonance frequencies with the changed spring stiffness change. This applies both to the resonance frequency of the tool holder 10 stimulable torsional vibrations about the axis of rotation D and of transversal oscillations in a plane containing the axis of rotation D. By forming a bracing assembly components sleeve 20 and screws 38 can thus the spring stiffness of the tool holder 10 be influenced such that unwanted vibrations in the operation of the tool holder 10 , for example, with a known number of blades one in the tool holder 10 clamped tool and known operating speed of the tool holder 10 , are more difficult to stimulate or are less likely to occur. This eventually becomes the one with the tool holder 10 achievable machining accuracy and also the Tool life increased.

In 2 and all the following figures, the same components are always provided with the same reference numerals, but increased by a multiple of the number 100 , Components are explained in detail only in connection with the figure in which they are shown for the first time. With respect to these components, reference is expressly made to their description in the figure in which they first appear.

The embodiment of 2 is essentially the same as 1 , Only the screws 138 are at the in 2 shown embodiment through through holes 136 in the tool holder 110 put through and in holes 140 with internal thread in the radial flange 134 screwed.

The longitudinal axis of the screws 138 is inclined with respect to the rotation axis D. The screws 138 are arranged such that their elongated imaginary longitudinal axes ideally intersect at a point on the axis of rotation D. This is from the screws 138 a force F acting in the direction of its longitudinal axes on the tool holder 110 transmitted, this force F has a Verspannungskraftkomponente VK in the axial direction and a force component VR in the radial direction. The tension force components VK, which at the support point 124 causes a corresponding bearing reaction force, in turn, sets the tensioning portion VA of the tool holder 110 under axial compressive stress with the above effects.

The in 3 illustrated tool holder 210 is not suitable for shrinking tool shanks, but is due to its clamping training 214 with resilient clamping segments 242 provided, which integral with the tool holder shank 218 are formed. The clamping segments 242 are displaceable by bending against their material elasticity to the axis of rotation D. The necessary bending force for clamping tool shanks in the clamping space 216 is through a cap sleeve 220 applied. This is the outer circumference 214a the clamping formation of the tool holder 210 conical to the clamping training near the longitudinal end of the tool holder 210 formed tapering. A surface normal of the truncated cone surface 214a the tension training 214 Therefore, it has a component in the direction of the rotation axis D and a component in the radial direction.

The cap sleeve 220 indicates at its Spannausbildungsnäheren longitudinal end 226 a conical inner surface 228a on. The conical inner surface 228a has substantially the same inclination as the conical outer surface 214a , This shows the conical inner surface 228a at least in the axial direction. Specifically, the surface (in the mounted state of the cap sleeve 220 ) due to their conicity on the one hand in the radial direction to the axis of rotation D and on the other in the axial direction to the coupling formation 212 out. The flat layout of the surfaces 214a and 228a together form the spine-like support point 224 ,

In the axial direction of the clamping training 214 away, near the coupling training 212 , is on the outer circumference 218a of the shaft area 218 an external thread 244 intended. With this external thread 244 is an internal thread 246 at the longitudinal end 232 the cap sleeve 220 engaged. The thread engagement of external thread 244 of the tool holder 210 and internal thread 246 the cap sleeve 220 forms the coupling training closer support point 222 , By screwing on the union nut 220 on the tool holder 210 So on the one hand, the necessary clamping force in the radial direction on the clamping segments 242 transferred, as well as the axial compressive stress in the bracing portion VA of the tool holder 210 causing axial stress component VK.

For better centering of the cap sleeve 220 is at this in the axial direction between the support points 222 and 224 a circumferential radial collar 248 formed, which projects radially inward and flat on the jacket 218a of the shaft area 218 of the tool holder 210 is applied.

In 4 is again a tool holder 310 with clamping arrangement 314 shown for shrinking clamping tool shanks, as in the 1 and 2 , Therefore, it is not necessary that the union nut 320 a force in the radial direction on the clamping arrangement 314 exercises. The cap sleeve 320 is therefore not designed to rest on a conical lateral surface. Rather, the cap sleeve 320 at her of tension training 314 associated longitudinal end 326 a radial projection 328 on, which with a mounted state of the cap sleeve 320 for coupling training 312 indicative and orthogonal to the rotation axis D contact surface 328a on an axis of rotation D also substantially orthogonal end face 314b of the tool holder 310 is applied. The investment engagement of the surfaces 328a and 314b forms a support point 324 , The other support point is as in 3 , by the thread engagement of external thread 344 of the tool holder 310 and internal thread 346 the cap sleeve 320 educated.

In the in 3 and 4 shown embodiments is the clamping training 214 respectively. 314 at least partially in the tensioning section VA.

In the 5 shown embodiment of the toolholder 410 is essentially a combination of the embodiments of 4 and the 1 and 2 : The coupling training closer support point 422 is how in 4 , formed by a threaded engagement of an external thread 444 on the tool holder 410 with an internal thread 446 a sleeve 420 ,

The tension training closer support point 324 is, however, according to the embodiments of the 1 and 2 educated. For a more detailed explanation of the design of the support points 422 and 424 is expressly based on the description of 1 and 2 respectively. 4 directed.

In the area of the support point 422 in which the one axial clamping of the clamping portion VA of the tool holder 410 causing tension together with the support point 424 is generated, are recesses 449 designed for a tool engagement. This can affect the tool holder 410 applied tensing force can be set very accurately.

In 6 is the sleeve 520 at her coupling education 512 closer longitudinal end 532 in engagement with the tool holder 510 , A plane orthogonal to the axis of rotation D. 534a of the radial flange 534 is in abutment with a surface orthogonal to the axis of rotation D. 512a at the coupling training 512 of the tool holder 510 , In addition, it is near the contact surface 512a the coupling training 512 a radial flange 534 radially surrounding outer centering collar 552 on the tool holder 510 educated. This centering collar 552 ensures a correct coaxial position of the sleeve 520 with respect to the tool holder 510 , A radially inwardly facing centering surface 552a of the centering collar 552 is in abutting engagement with a radially outwardly facing surface 534b of the radial flange 534 , To a displacement of the sleeve at the support point thus formed 522 to avoid are the radial flange 534 and the centering collar 552 through a weld 554 , which rotates about the tool holder, inextricably linked together.

At the headquarters 524 is at the Mantefläche 518a of the shaft area 518 of the tool holder 510 an external thread 544 provided, on which an adjusting nut 538 is screwed on. The adjusting nut 538 pushes in the direction of the axis of rotation D on the axis of rotation D substantially orthogonal end face 526a the sleeve 520 , By selecting the tightening torque of the adjusting screw 538 Can the on the sleeve 520 applied compressive force can be adjusted. The bracing portion VA of the tool holder 510 is thus set specifically under Axialzugspannung. The on the sleeve 520 acting compressive forces act in the tensioning section VA as a reaction train forces on the tool holder 510 ,

In 7 is a two-part tool holder 610 shown. The tool holder 610 includes a coupling-side tool holder part 610a at which the coupling training 612 is provided, and a tension-side tool holder part 610b at which the clamping training 614 is provided. The two tool holder parts 610a and 610b are bolted together, with a pin 656 with external thread on the tension training tool holder part 610b in an opening 658 at the coupling training side tool holder part 610a is screwed.

The tool holder parts 610a and 610b are in the process against a conical sleeve that tapers to form a stress 620 tightened. With an orthogonal to the rotation axis D end face end face 626a is the sleeve 620 at an axis of rotation D also orthogonal contact surface 612a the tension training 612 at. Radially outward is the coupling training nearer longitudinal end 632 the sleeve 620 from a covenant 652 at the coupling training 612 surrounded and thereby centered with respect to the axis of rotation D. At its tension training nearer longitudinal end 626 is the sleeve through the tool holder part 610b centered on its inner circumference with respect to the axis of rotation D, wherein the end face 626a the tension training closer longitudinal end 626 the sleeve 620 on a damping ring 659 is present, which between the frontal longitudinal end 626 the sleeve 620 and the tool holder part 610b with the tension training 614 is interposed in the axial direction. The damping ring 659 may be made of ceramic, for example, and has a different material elasticity than the tool holder 610 and / or as the sleeve 620 on. It may be thought that the damping ring 659 unwanted movements of the tool holder 610 damped by internal friction, or that the sleeve 620 and / or the tool holder 610 , here the tool holder part 610b , relative to the sealing ring 659 move and this unwanted movement is damped by friction.

At the in 7 illustrated embodiment, the sleeve 620 due to the screw connection of the tool holder parts 610a and 610b set under compressive stress in the axial direction, so that the clamping portion VA of the tool holder 610 is under mechanical tension. This tension can in their amount by applying a certain torque in the screwing of the two tool holder parts 610a and 610b be selected suitable. An additional option for fine adjustment of the desired Axialverspannung is the use of a thread with very little pitch on the pin 656 and at the opening 658 ,

In the 8th embodiment shown corresponds essentially to that of 7 , In the embodiment of 8th only the coupling training closer longitudinal end 726 the sleeve 720 through the covenant 752 centered on its inner circumference and not on its outer periphery.

In 9 is again a two-piece tool holder 810 with the tool holder parts 810a and 810b shown. Unlike in the 7 and 8th are the tool holder parts 810a and 810b not screwed together. Rather, the pin is 856 of the tool holder part 810b only in the opening 858 of the tool holder part 810a plugged in.

In the manufacture of the tool holder 810 this is after the mating of the two tool holder parts 810a and 810b in the axial direction is subjected to a compressive force, so that its one length is shortened under the action of the pressing force corresponding to the respective material elasticities. The tool holder 810 can be shortened until the two end faces 826a 832a the sleeve 820 at the respective associated mating surfaces on the tool holder parts 810a respectively. 810b issue. Then the sleeve 820 at its two longitudinal ends 826 and 832 unsolvable by welding with the respective tool holder parts 810a and 810b connected. This is done by applying a weld around running 854 at the coupling training closer longitudinal end 832 and a circumferential weld 855 at the tension training nearer longitudinal end 826 the sleeve 820 , After applying the weld, the force exerted by a press or a clamping device on the tool holder axial mounting pressure load is released, so that the previously shortened tool holder 810 against the material elasticity of the sleeve 820 relaxed. This is the sleeve 820 put under tension, so that between the welds 854 and 855 located axial tensioning section is under compressive stress.

The embodiment of 10 is essentially the same as 9 , Only the coupling training closer longitudinal end 932 the sleeve 920 is no longer from the federal government 952 centered on its outer or inner circumference. Rather, the longitudinal end meet 932 the sleeve 920 and a face of the covenant 952 frontally to each other. A centering can be done here during assembly, for example by a connection point between the federal government 952 and longitudinal end 932 encompassing outer sleeve.

The embodiment of 11 is essentially the same as 10 , In the embodiment of 11 is for better centering of the coupling formation closer longitudinal end 1032 the sleeve 1020 this longitudinal end 1032 graduated, so that the federal government 1052 an axial projection 1033 at the longitudinal end 1032 the sleeve 1020 radially surrounds the outside and so the sleeve at its longitudinal end 1032 centered.

In the 12 illustrated embodiment corresponds in its state of tension of the embodiment of 11 , Additionally is on the outer jacket 1118a a vibrating mass piece 1160 provided displaceable in the axial direction, as indicated by the double arrow P.

The oscillating mass piece 1160 acts in addition to the axial strain of an undesirable vibration excitation of the tool holder 1110 opposite. This applies to both torsional and transverse vibrations.

Should the tool holder 1110 are excited to vibrate, thereby also the slender shaft section 1118 set in motion. By a suitable choice of the axial mounting location of the oscillating mass piece 1160 can be achieved that the vibrating mass and the shaft section carrying it 1118 out of phase is excited to a vibration of the same frequency, so that it is on the overall system tool holder 1110 destructive interference leads to an overall vibration of lesser or even vanishing amplitude.

The oscillating mass piece 1160 can be moved, rotated, screwed and the like on the shaft portion 1118 be arranged. The oscillating mass piece 1160 is formed by a simple ring, through its inner opening 1160a the shaft section 1118 is guided. Determining the axial position of the oscillating mass piece 1160 on the shaft section 1118 this is additionally secured in the radial direction, such as by pinning.

The embodiment of 13 is different from that of 12 on the one hand, that the tool holder part 1210b with the clamping training 1214 only over the sleeve 1220 with the tool holder part 1210a with the coupling training 1212 connected is. The shaft section 1218 , which integrally on the tool holder part 1210b is formed, with its free longitudinal end is not enough for tool holder part 1210a but ends up cantilevered in the sleeve 1220 surrounded space.

On the other hand, the embodiment differs from 13 from the of 12 in that the sleeve 1220 by two sleeve coats arranged coaxially over a large common axial section 1220b and 1220c is formed.

The freely projecting longitudinal end of the shaft portion 1218 allows the excitation of other forms of vibration than the bilaterally clamped shaft 1118 in the embodiment of 12 ,

The axial strain is in the embodiment of 13 by a tension of the two sleeve coats 1220b and 1220c achieved relative to each other. Every sleeve coat 1220b and 1220c is separately at each of its longitudinal ends with the tool holder parts associated with these longitudinal ends 1210a and 1210b welded. A centering is achieved for example by the fact that the circumferential collar 1252 on tool holder part 1210a the radially inner sleeve jacket 1220c surrounds on the outer periphery, so that a centering of the sleeve sheath 1220c concerning the tool holder part 1210a is reached. The radially inner sleeve jacket 1220c in turn surrounds radially outside a step portion of the tool holder part 1210b so that this through the inner sleeve jacket 1220c is centered. The connection situation of the sleeve jacket 1220c with the individual tool holder parts 1210a and 1210b essentially corresponds to the connection situation of the sleeve 820 in the embodiment of 9 , whose description is expressly referred to here.

After attaching the inner sleeve sheath 1220c becomes the tool holder 1210 as related to the embodiment of FIG 9 has been described, applied in the axial direction with a compressive force, so that the axial length of the tool holder 1210 is shortened. In this shortened under external force state, the longitudinal ends of the outer sleeve sheath 1220b with the respective tool holder parts 1210a and 1210b connected by welding inextricably. Subsequently, the externally applied axial compressive force is released, so that the inner sleeve casing is under axial compressive stress, while the outer sleeve casing is under axial tension.

The following 14 to 16 serve to illustrate further embodiments of oscillating mass pieces, which can cooperate with the tool holder. The formation and connection of the sleeve with the tool holder parts, which comprise the coupling formation or the clamping formation corresponds to that in 12 . described

In 14 is on a running in the axial direction shank approach 1318 a vibrating rod 1362 Shrunk, screwed on, soldered on, welded on, glued on or otherwise firmly attached to it. On the swinging rod 1362 is in the axial direction, ie in the direction of the double arrow P, displaceable a vibrating mass piece 1360 arranged. The free end of the vibrating rod 1362 is, as indicated by the double arrows A, deflected around the location of the fixed clamping of the vibrating rod to the transverse vibration. The frequencies that can be excited on the vibrating rod, are determined by the axial position of the vibrating mass piece 1360 certainly.

In the 15 embodiment shown corresponds essentially to that of 14 , only the vibrating rod 1462 is for lubricant supply to the clamping space 1416 pierced and with a sealing ring 1464 in an opening 1458 sealed. Although this point of the seal does not form a real bearing point, the freedom of movement of the free end of the vibrating rod is still 1462 over the embodiment of 14 limited. On the vibrating rod can therefore form vibration modes, which is a hybrid form of the vibration modes of the embodiments of 13 and 14 on the one hand and of 12 on the other hand.

In the embodiment of 16 is the sleeve 1520 with the tool holder parts 1510a and 1510b connected in the same way as in the embodiment of 10 the description of which was expressly referred to.

The tool holder parts 1510a . 1510b and the sleeve 1520 define a volume of space 1566 , The sleeve 1520 also has one to the vibrating bar 1562 reaching, substantially orthogonal to the axis of rotation D extending partition 1568 on which the volume of space 1566 in two sub-volumes 1566a and 1566b divided.

The closer to the tool holder part 1510a with the coupling training 1512 lying partial volume 1566a is with a viscous or viscoelastic mass 1570 filled. During operation, ie during rotation of the tool holder 1510 , exerts the viscous or viscoelastic material 1570 due to the centrifugal action in the radial direction, a force on the wall of the sleeve 1520 out. Due to the taper of the sleeve 1520 as well as due to the tight clamping of the sleeve 1520 at their longitudinal ends 1526 and 1532 this force acting radially outward on the sleeve wall causes a force component acting in the axial direction in the sleeve wall.

In the viscous or viscoelastic mass is additionally a vibrating mass piece 1560 provided, which according to a variant fixed to the vibrating rod 1562 may be connected and which according to another embodiment floating in the viscoelastic mass 1570 may be included, allowing a power transmission from the tool holder 1510 on the swing mass piece 1560 takes place only through the intermediary of the vibrating mass surrounding viscous or viscoelastic material. In this latter case, it is preferable to use tough materials, such as Bingham fluids, which begin to flow only from a predetermined mechanical threshold stress, or elastomeric materials and the like may be used.

In 17 is, as in 1 to 6 , a one-piece tool holder 1610 shown. A conical sleeve 1620 which the tool holder 1610 radially outwardly surrounds, is at the radially outer end of its radial flange 1634 at the longitudinal end 1632 with the tool holder 1610 welded. Likewise, the sleeve 1620 at her the tension training 1614 facing longitudinal end 1626 with the tool holder 1610 be welded, as in the upper half of the in 17 illustrated tool holder 1610 is shown.

The one from the sleeve 1620 surrounded axial portion of the tool holder 1610 is provided over a predetermined axial portion with a circumferential recess, so that the tool holder 1610 together with the sleeve 1620 a volume of space 1666 defined, in which in the present example the 17 oil 1670 filled so that the entire volume of space 1666 with the oil 1670 is filled.

Upon rotation of the tool holder 1610 practice the oil 1670 due to centrifugal force, a force radially outward on the inner wall of the sleeve 1620 out. Due to the taper of the sleeve 1620 as well as by their fixed clamping at the longitudinal ends 1626 and 1632 this radially outwardly acting force causes a force acting in the axial direction on the sleeve, so that a clamping portion of the tool holder 1610 is under mechanical compressive stress.

Instead of a welded joint, the conical sleeve in the region of its span training near the longitudinal end 1626 only flat with its conical inner surface 1620d on a corresponding conical outer surface 1618a of the shaft portion 1618 abut, as in the lower half of the tool holder 1610 in 17 is shown. The upon rotation of the tool holder in the radial direction of the sleeve 1620 acting force calls in the direction of the sleeve wall running and coupling training 1612 pointing force component through which the region of the longitudinal end 1626 slightly to the coupling training 1612 is shifted towards. This causes a sealing concern of the conical inner surface 1620d the sleeve 1620 and the conical outer surface 1618a of the shaft portion 1618 together.

In addition, there is a radial flange 1634 a pressurizing device 1672 provided, comprising one with its radially inner side in wetting contact with the oil 1670 standing circumferential rubber 1674 as well as around the circumference of the radial flange 1634 at equal intervals distributed adjusting screws 1676 , With the screws 1676 can the stretch rubber 1674 radially inward into the volume of the room 1666 be adjusted into it. This will cause the pressure in the oil 1670 increases, resulting in additional axial clamping of the tool holder 1610 about the force of the oil 1670 on the sleeve 1620 leads. Instead of a circumferential expansion rubber and the screws each associated piston made of ceramic, metal, etc. may be provided.

At the in 18 shown embodiment, which extends the tool holder 1710 radially outside surrounding sleeve 1720 about the clamping training 1714 in the axial direction.

At his coupling education 1712 closer longitudinal end 1732 is the sleeve 1720 with its axis of rotation D substantially orthogonal end face 1732a at a substantially orthogonal to the axis of rotation bearing surface 1712a at.

The clamping training 1714 has an internal thread, which at the clamping space 1716 is formed bounding inner wall. In this internal thread of the clamping training is a clamping thread 1778 a milling head 1780 screwed. The tension training 1714 associated longitudinal end 1726 the sleeve 1720 comes with its to the axis of rotation D substantially orthogonal end face 1726A to a to the rotation axis D substantially also orthogonal rear surface 1780a of the milling head 1780 to the plant. By screwing in the milling head 1780 in the clamping space 1716 against the outer sleeve 1720 becomes the outer sleeve 1720 placed under compressive stress during the surrounded by the outer sleeve bracing portion VA of the tool holder 1710 is put under tension. Instead of a milling head 1780 can be any other tool with clamping thread in the clamping space 1716 be screwed.

In 19 an embodiment is shown, which is essentially that of 18 equivalent. Instead of the milling head 1780 is a shrinking attachment 1880 in the clamping space 1816 against the sleeve 1820 screwed. The shrinking attachment 1880 again has a clamping space 1816 ' in which tool shanks can be clamped, as in connection with the clamping training 14 the embodiment of 1 has been described.

In 20 is the sleeve 1920 from the tool holder 1910 surrounded radially on the outside. At her the tension training 1914 closer longitudinal end 1926 is the sleeve 1920 with intermediate arrangement of a compensation element 1982 at a projection 1984 the tension training 1914 at.

From the side of the coupling training 1912 here is a tensioning element 1938 in the tool holder 1910 screwed. An external thread on the clamping element 1938 is with an internal thread in the coupling section 1912 of the tool holder 1910 in screw engagement. Between the clamping element 1938 and the coupling training 1912 facing longitudinal end 1932 the sleeve 1920 is a previously described damping element 1959 axially interposed. The aforementioned compensation element 1982 Among other things, it serves the purpose of heat shrinkage training 1914 starting to prevent.

The sleeve 1920 is hollow for the passage of cooling fluid and has at its longitudinal end 1926 an adjustable in the axial direction stop unit 1985 on, with which an axial end stop for a in the clamping space 1916 aufeinegenden tool shank on.

In 21 is a tool holder 2010 shown on which of the coupling training 2012 up to its clamping training near the longitudinal end of a one of the material of the tool holder 2010 different material 2087 applied to this, preferably shrunk. This also causes an axial tension of an axial section of the tool holder 2010 reached. The material may be metal, ceramic, or an electrostrictive material which changes its longitudinal dimension in at least one spatial direction by applying an electrical voltage. Thus, by applying an electrical voltage to the material applied to the material from this on the tool holder 2010 applied force to be changed.

In 22 is another tool holder 2110 shown, which in its basic structure the tool holder 1310 out 14 equivalent. However, the tool holder points 2110 no oscillating body. The sleeve 2120 as well as the tool holder parts 2110a and 2110b define together a closed volume of space 2166 , In this is a liquid, such as an oil, 2170 filled, in such a way that only a part of the closed volume of space of the liquid 2170 is taken.

Upon rotation of the tool holder 2110 around its axis of rotation D, a centrifugal force acts radially outward on the oil 2170 , which thereby on the sleeve 2120 comes to the plant. This condition is in 22 shown. Due to the centrifugal force exerts the oil 2170 in the closed room volume 2166 a force VR radially outward on the sleeve 2120 out. Due to the taper of the sleeve 2120 a component VT of the force VR acts in the direction of the sleeve wall. This force component VT in turn causes an axial stress in the sleeve 2120 ,

23 shows a tool holder 2210 shrink-holder type with a clamping shank 2218 who at one end of one through the coupling education 2212 formed, achsnormale shoulder 2288 protrudes axially and at its coupling training 2212 axially facing away from its clamping training 2214 a centric clamping recess 2216 for shrinking the shaft of the tool, not shown, as shown by 1 was explained in more detail. Between the coupling training 2212 and the tension training 2214 is the span shaft 2218 from a sleeve forming the tensioning arrangement 2220 Enclosed with her the coupling training 2212 adjacent end in a support point 2222 at the annular end face 2288 axially supported. With her other, the Spannausbildung 2214 axially adjacent support end 2224 the sleeve sits 2220 in a frictional region 2289 in a press fit on the circumference of the shaft portion 2218 , Axial between the frictional engagement area 2289 and the support point 2222 the sleeve runs 2220 forming an annular gap 2290 at a radial distance from the shaft portion 2218 , The in friction section 2289 in interference fit superimposed peripheral surfaces on the inner surface of the sleeve 2220 on the one hand and the shaft portion 2218 on the other hand have the shape of a steep cone 2291 extending over the predetermined axial length with a slope of about 0.1 to the clamping formation 2214 axially tapered so that the cone of the shaft portion 2218 based on the end position of the patch sleeve 2220 has an excess to produce the press fit. It is understood, however, that in the friction section 2289 adjacent surfaces can also be designed as cylindrical surfaces. To generate the biasing force of the clamping training 2214 facing forehead 2292 the sleeve with a force of several tons, for example 10 tons against the annular surface 2288 pressed, resulting in a resilient tension of the sleeve 2220 leads. The press fit in the area 2289 produces a total of a holding force, the thus biased sleeve 2220 in its pre-stressed position. At the same time, however, in the coupling training 2212 axially facing portions of the Reibschlussabschnitts 2289 a relative movement between the sleeve 2220 and the power shaft 2218 allowed against the frictional engagement force, whereby the rotational and bending vibrations of the shaft portion 2218 be steamed.

To improve the rigidity of the shaft portion 2218 is the one for coupling training 2212 adjacent end portion of the sleeve 2218 as axial to the clamping training 2214 tapered cone section 2293 trained, one the clamping shaft 2218 enclosing damping ring 2294 Covered from stiff-elastic material.

24 shows a variant of a tool holder 2310 of the shrinking type, different from the variant of 23 only differs in that the friction section 2389 in which the shaft portion 2318 radial oversize relative to the inner diameter of the sleeve 2320 has primarily for the friction damping of the tool holder 2310 is measured while the support point 2324 on which the sleeve 2320 with the biasing force FK supported by a nut 2395 is formed on an external thread of the clamping shaft 2318 is screwed on. Again, the biasing force with which the sleeve 2320 between their bases 2322 and 2324 clamped is several tons, for example 10 tons. The shape of the sleeve 2320 otherwise corresponds to the shape of the sleeve 2220 in 23 , but in addition in the field of clamping training 2314 facing end another damping ring 2396 between the sleeve 2320 and the power shaft 2318 is provided.

The design after 25 is different from the variant of 24 essentially only in that part of the axial length of the sleeve 2420 as a sleeve-shaped wave spring 2497 is formed, which generates both axial and radial spring forces at axial and radial tension.

26 shows a variant in which the principles of the variant of 23 in an embodiment similar to the variant of 1 are realized. For axial clamping of the sleeve 2520 is to form the support point 2524 at their coupling training 2514 adjacent end an inwardly projecting radial projection 2528 Molded on one shoulder 2530 of the shaft portion 2518 supported. At the other, the coupling training 2512 adjacent end wears the sleeve 2520 a radially outward radial flange 2534 used to produce the biasing force VK with screws 2538 against the ring shoulder 2588 the coupling training 2512 is curious. Also in this embodiment is a frictional engagement section 2589 provided in which the optionally conical (section 2591 ) Outer circumference of the flange portion 2518 radially against the in this area also conical inner shell of the sleeve 2520 is stretched to form a frictional connection. In the area of the support point 2522 is the inner jacket of the sleeve 2520 formed conically and in turn covers a damping ring 94 , Axial between the flange 2534 and the frictional engagement section 2589 the sleeve runs 2520 forming an annular gap 2590 at a radial distance to the shaft portion 2518 ,

27 shows a tool holder 2610 of the shrinking type, which the principles of the variant of 23 in an embodiment according to 5 realized. During the tension training 2614 adjacent support point 2624 by a radially inwardly projecting radial projection 2628 which is on an annular shoulder 2630 of the tension shaft 2618 is applied, is formed, the sleeve 2620 on the side of the coupling training 2612 for the formation of the support point 2624 with an internal thread on an external thread 2644 of the tension shaft 2618 screwed. The support point 2624 adjacent encloses the sleeve 2620 in a frictional engagement section 2689 the circumference of the shaft section 2618 , The shaft section 2618 has in this area radial excess and can, as well as the inner shell of the sleeve 2620 be slightly conical. the sleeve 2620 extends in the other with radial distance (annular gap 2690 ) from the shaft portion 2618 , Damping rings are included 2694 and 2696 recognizable.

28 shows a tool holder 2710 of the shrinking type similar to the variant of 17 , On the here cone-shaped clamping shaft 2718 is a likewise cone-shaped sleeve 2720 forming an annular chamber 2766 put on and at both support points 2722 and 2724 over the entire circumference tight and firm with the tool holder 2710 connected, welded here. In the illustrated embodiment, the sleeve sits 2720 with its one end on an annular face 2788 the coupling training 2712 on that the foot of the shaft section 2718 encloses. At the other, the support point 2724 forming end is the sleeve with a radially inwardly projecting annular flange 2728 provided on an axially in the same direction as the shoulder 2788 pointing ring shoulder 2730 the shaft portion 2718 is applied. The sleeve 2720 can therefore at both nodes 2722 and 2724 in one operation, in particular by friction welding with the shaft portion 2718 get connected.

The annular chamber 2766 between the shaft portion 2718 and the sleeve 2720 is via a supply channel 2797 accessible from the outside, here via a centric channel 2798 of the tool holder 2710 , To generate a biasing force is via the channels 2798 and 2797 in the manufacture of the tool holder 2710 flowable material in the annular chamber 2766 pressed, which in the annular chamber 2766 subsequent solidifies its consistency. The material may be a rubber compound that is in the chamber 2766 is vulcanized. It can be too to be a curable plastic material, such as a resin or the like, which in the annulus 2766 cures. Also suitable are sinterable materials. That in the annulus 2766 introduced material puffs the sleeve 2720 and thereby generates the axial biasing force VK. The introduced material must be able to solidify under the increased application pressure, so that it can maintain the increased pressure even in the solidified state. The material may have elastic properties and / or on the sleeve 2720 or the shaft portion 2718 in a frictional engagement. It is understood that the material optionally also from the outside through an opening of the sleeve 2720 can be introduced, as with 17 is indicated.

29 shows a further variant of a tool holder 2810 of the shrinking type, in which similar to the variant of 23 that of the clamping training 2814 axially adjacent end of the tensioning arrangement forming sleeve 2820 in a frictional engagement section 2889 on the clamping shaft 2818 is applied. The frictional engagement section 2889 does not need axial fixation forces for a press-fit fixation of the sleeve 2820 muster. The sleeve is supported by its clamping training 2814 adjacent end to a radially elastic locking ring 2895 detachable in an annular groove on the circumference of the clamping shaft 2818 is snapped. Instead of the circlip 2895 can be similar to the variant of 24 if necessary, also one on the Spannschaft 2818 be screwed nut provided. The circumferential contour of the clamping shaft 2818 and the sleeve adjacent to it 2820 can in the friction section 2889 again the shape of a self-locking, steep cone 2891 have as the basis of the 23 was explained. It is understood that here as well, as with all the previously described variants, a cylindrical frictional engagement region can be provided instead of the cone. The frictional engagement is in turn due to a certain excess of the diameter of the shaft portion 2818 based on the inner diameter of the sleeve 2820 reached.

The tension training 2812 axially adjacent end of the sleeve 2820 is on a hydraulic support assembly 2899 axially supported. The support arrangement 2899 has one with a hydraulic pressure medium 2899a filled, to the axis of rotation D centric annular chamber 2899b in which sealed an annular piston 2899c is guided axially displaceable. The sleeve 2820 rests on the ring piston 2899c in the area at the foot of the shaft section 2818 formed annular surface 2888 from. One with the print medium 2899a in the annulus 2899b communicating piston screw 2899d allows a variable pressure load of the pressure medium 2899a and thus over the ring piston 2899c an axial tension of the sleeve 2820 ,

The pressure medium may be hydraulic oil or the like. Also suitable are flowable and / or rubber-elastic materials or visco-elastic compositions. It is understood that the ring piston 2899c also integral and integral with the sleeve 2820 can be formed.

Not shown in detail are embodiments which are kinematically inverse installation position of the support device 2899 also a tensile load of the sleeve 2820 allow. It is further understood that the support means 2899 can be used in all other previously explained tool holders for the axial clamping of the bracing.

The in the 1 to 29 illustrated features of the tool holder can be combined with each other as desired.

Claims (42)

Tool holder for a tool rotatable about a rotation axis (D), in particular a drilling, milling, friction or grinding tool, comprising a clamping shank ( 18 ; 118 ; ...), which at its end shaft region a clamping training ( 14 ; 114 ; ...) for holding the tool and at its other end-side shaft portion a coupling formation ( 12 ; 112 ; ...) for coupling with a machine tool, characterized in that the tool holder ( 10 ; 110 ; ...) a tensioning arrangement ( 20 ; 120 ; ...), which at least during operation of the tool holder ( 10 ; 110 ; ...) in an axial tension section (VA) forming axial portion of the clamping shaft ( 18 ; 118 ; ...) exerts a tensioning force with a tensioning component (VK) acting in the axial direction. Tool holder according to claim 1, characterized in that the tensioning arrangement ( 20 ; 120 ; ...) coaxial with the tensioning section (VA) of the tool holder (( 10 ; 110 ; ...) is arranged. Tool holder according to claim 2, characterized in that the tensioning arrangement as a sleeve ( 20 ; 120 ; ...) is formed, the axial tensioning section (VA) of the clamping shaft ( 18 ; 118 ; ...) surrounds coaxially. Tool holder according to one of claims 1 to 3, characterized in that the tensioning arrangement ( 20 ) at two support points spaced apart in the axial direction ( 22 . 24 ; 122 . 124 ; ...) of the tool holder is supported. Tool holder according to claim 4, characterized in that the clamping section (VA) in the axial direction between the clamping formation ( 14 ; 114 ; ...) and the coupling training ( 12 ; 112 ; ...) is located. Tool holder according to claim 5, characterized in that the clamping training ( 12 ; 112 ; 412 ; ...) axially over the sleeve ( 20 ; 120 ; 420 ; ...) protrudes and is designed for a shrink fit position of the tool. Tool holder according to one of claims 1 to 6, characterized in that the tensioning arrangement ( 20 ; 120 ; ...) for the change of the team ( 18 ; 118 ; ...) acting tension (VK) is formed. Tool holder according to claim 7, characterized in that the tool holder ( 610 ; 710 ; ...) is made of several parts, wherein at least two tool holder parts ( 610a . 610b ; 710a . 710b ; ...) are displaceable in the axial direction relative to each other and wherein two tool holder parts ( 610a . 610b ; 710a . 710b ; ...) one support point each ( 622 . 624 ; 722 . 724 ; ...) exhibit. Tool holder according to claim 8, characterized in that the at least two tool holder parts ( 610a . 610b ; 710a . 710b ; ...) can be screwed together with a screw axis parallel to the axis of rotation. Tool holder according to one of claims 7 to 9, characterized in that at least one of the support points ( 22 ; 122 ; ...) for the axial displacement of a section supported on it ( 32 ; 132 ; ...) of the tensioning arrangement ( 20 ; 120 ; ...) is trained. Tool holder according to claim 10, characterized in that the at least one support point ( 222 ; 322 ; ...) a thread ( 244 ; 344 ; ...), with which the at the support point ( 222 ; 322 ; ...) supported section ( 232 ; 332 ; ...) of the tensioning arrangement ( 220 ; 320 ; ...) is displaceable in the axial direction. Tool holder according to one of claims 4 to 11, characterized in that at least one of the support points ( 24 ; 124 ; 224 ; ...) of an at least in axial Richtun contact engagement g facing peripheral surface portion ( 30a ; 130a ; 214a ; ...), preferably outer peripheral surface portion, is formed, with which a mating surface portion ( 28a ; 128a ; 228a ; ...) of the tensioning arrangement ( 20 ; 120 ; 220 ; ...) is in investment engagement or can be brought into investment engagement. Tool holder according to claim 12, characterized in that the clamping training ( 212 ) with respect to the axis of rotation (D) conical peripheral surface portion ( 214a ), preferably outer peripheral surface portion ( 214a ), wherein the mating surface portion ( 228a ) of the tensioning arrangement ( 220 ) with the conical peripheral surface portion ( 214a ) is in investment engagement or can be brought into investment engagement. Tool holder according to one of claims 3 to 13, characterized in that the sleeve ( 20 ; 120 ; ...) has a closed cross section at least in an axial section. Tool holder according to claim 14, characterized in that the sleeve ( 1220 ) a plurality of coaxial with the tool holder ( 1210 ), at least in an axial section adjacent to each other sleeve shells ( 1220b . 1220c ). Tool holder according to claim 14 or 15, characterized in that at least one sleeve casing ( 1220b . 1220c ), preferably the entire sleeve ( 1220 ), at least one axial end region ( 1226 . 1232 ), preferably at both axial end regions ( 1226 . 1232 ), with a collar formed on the tool holder ( 1248 . 1252 ) is positively engaged. Tool holder according to one of claims 14 to 16, characterized in that at least one sleeve jacket, preferably the entire sleeve ( 620 ), at least one axial end region ( 626 ) with interposition of a damping piece ( 659 ) on the tool holder ( 610 ) or is connected to this. Tool holder according to one of claims 14 to 17, characterized in that at least one sleeve casing ( 1220b . 1220c ), preferably the entire sleeve ( 1220 ), at least one axial end region ( 1226 . 1232 ), such as by soldering, welding, in particular friction welding, gluing or similar joining methods for permanent connection, with the tool holder ( 1210 ) connected is. Tool holder according to claim 18, characterized in that at least one sleeve casing ( 1220b . 1220c ), preferably the entire sleeve ( 1220 ), at both axial end regions ( 1226 . 1232 ) firmly with the tool holder ( 1210 ) connected is. Tool holder according to claim 19, characterized in that at least one sleeve jacket, preferably the entire sleeve ( 1620 ), with the tool holder ( 1610 ) a closed volume ( 1666 ), about a chamber ( 1666 ) defined with a flowable material ( 1670 ); in front preferably a liquid ( 1670 ), or / and with an elastic material, preferably a rubber-like material, filled or fillable. Tool holder according to claim 20, characterized in that pressure changing means ( 1672 ) are provided to the pressure of the flowable material ( 1670 ) to change. Tool holder according to claim 21, characterized in that the pressure changing means ( 1672 ) Medium ( 1674 . 1676 ) for changing the closed volume ( 1666 ), such as at least one set screw ( 1676 ) and / or at least one displaceable piston ( 1674 ), preferably at least one piston ( 1674 ) acting seal ( 1674 ). Tool holder according to claim 4, optionally incorporating at least one of claims 7 to 12 and 14 to 18, characterized in that the one support point ( 1722 ; 1822 ; ...) on the tool holder ( 1710 ; 1810 ; ...) and the other support point ( 1724 ; 1824 ; ...) on one in the tool holder ( 1710 ; 1810 ; ...) clamped or clamped tool is provided. Tool holder according to claim 23, characterized in that the actuator ( 1780 ; 1880 ; ...) one in the tool holder ( 1710 ; 1810 ) is clamped or clamped tool with which an axial end portion ( 1726 ; 1826 ) of the tensioning arrangement ( 1720 ; 1820 ; ...) can be brought into contact with the force of engagement or in contact with the machine, preferably by a tensioning thread ( 1778 ; 1878 ), in the axial direction on the tool holder ( 1710 ; 1810 ; ...) is relocatable. Tool holder according to one of claims 1, 2 and 4 to 23, characterized in that the tool holder ( 1910 ) the tension arrangement ( 1920 ) coaxially surrounds. Tool holder according to one of claims 3 to 24, characterized in that the sleeve ( 2220 ; 2320 ; ...) at least in one subarea ( 2289 ; 2389 ; ...) of its axial length frictionally engaged on the circumference of the clamping shaft ( 2218 ; 2318 ; ...) is present. Tool holder according to claim 26, characterized in that the sleeve ( 2220 ) with its two ends axially biased on the tool holder ( 2210 ), whereby that of the clamping training ( 2214 ) axially near the end of the sleeve ( 2220 ) in a frictional engagement section ( 2289 ) in the press fit frictionally axially fixed to the clamping shaft ( 2218 ) is held. Tool holder according to claim 26 or 27, characterized in that the sleeve ( 2220 ; 2320 ; ...) and the Spannschaft ( 2218 ; 2318 ; ...) at least in a part of the frictional engagement section ( 2289 ; 2389 ; ...) adapted to one another have a slightly conical shape. Tool holder according to claim 27 or 28, characterized in that the sleeve ( 2220 ; 2320 ) axially biased to pressure on the tool holder ( 2210 ; 2310 ; ...) is supported and axially between the Reibschlussabschnitt ( 2289 ; 2389 ; ...) and the axial of the coupling training ( 2212 ; 2312 ; ...), on the tool holder ( 2210 ; 2310 ) supported end the clamping shaft ( 2218 ; 2318 ; ...) encloses with radial distance. Tool holder according to claim 29, characterized in that axially between the frictionally engaging portion ( 2289 ; 2389 ; ...) and the tool holder ( 2210 ; 2310 ; ...) supported at the other end at least one damping ring ( 2294 ; 2394 ; ...) of an elastically compressible material between the circumference of the clamping shaft ( 2218 ; 2318 ; ...) and the inner shell of the sleeve ( 2220 ; 2320 ; ...) is arranged. Tool holder according to one of claims 3 to 30, characterized in that the clamping shaft ( 18 ; 118 ; ...) in an annular shoulder ( 12a ; 2288 ; ...) of the coupling training ( 12 ; 112 ; ...) passes over and the sleeve ( 20 ; 120 ; ...) at the ring shoulder ( 12a ; 2288 ; ...) is axially supported. Tool holder according to claim 31, characterized in that the at the annular shoulder ( 2288 ; ...) supported end of the sleeve ( 2220 ; ...) as a cone section ( 2293 ; ...), which extends from the annular shoulder ( 2288 ; ...) tapered away axially. Tool holder according to claim 32, characterized in that the cone section ( 2293 ; ...) a damping ring ( 2294 ; ...) covered. Tool holder according to one of claims 31 to 33, characterized in that the sleeve ( 520 ; 620 ; ...) is biased axially to pressure. Tool holder according to one of claims 3 to 6, characterized in that the axial ends of the sleeve ( 2720 ) tensile strength and tight with the tool holder 82710 ), in particular friction-welded, that the sleeve ( 2720 ) the span shaft ( 2718 ) encloses with radial spacing and for generating an axial tensile stress of the sleeve ( 2720 ) between the clamping shaft ( 2718 ) and the sleeve ( 2720 ) under pressure material, in particular elastic material is inserted. Tool holder according to one of claims 3 to 35, characterized in that the sleeve ( 2420 ) an axially resilient wave spring section ( 2497 ). Tool holder according to one of claims 3 to 36, characterized in that the sleeve ( 2820 ) with its two ends axially on the tool holder ( 2810 ) is supported, wherein in Abstützweg one of the two ends of the sleeve ( 2820 ) a relative to the tool holder ( 2810 ) axially movable support device ( 2899 ) is arranged, the at least one support piston ( 2899c ), which in an associated, a flowable or plastically deformable pressure medium ( 2899a ) containing pressure chamber ( 2899b ) is guided axially displaceable, wherein the pressure chamber ( 2899b ) an adjustment element ( 2899d ) for changing the pressure in the pressure medium ( 2899a ) assigned. Tool holder according to claim 37, characterized in that the support piston ( 2899c ) than in a pressure chamber ( 2899b ) forming annular space axially displaceable annular piston is formed, on which one of the two ends of the sleeve ( 2820 ) or to which it is connected. Tool holder according to claim 37 or 38, characterized in that the adjusting element ( 2899d ) one on the print medium ( 2899a ) acting piston screw is. Tool holder according to one of claims 37 to 39, characterized in that the other of the two ends of the sleeve ( 2820 ) firmly with the clamping shaft ( 2818 ) or on the collar of the Spannschafts ( 2818 ), in particular a detachable on the clamping shaft ( 2818 ) retaining ring ( 2895 ) is axially supported. Tool holder according to the preamble of claim 1, optionally incorporating further features of at least one of the preceding claims, characterized in that on the tool holder ( 1110 ; 1210 ; ...), preferably displaceable in the axial direction, a vibrating mass piece ( 1160 ; 1260 ; ...) is provided. Tool holder according to claim 41, characterized in that the oscillating mass piece ( 1160 ; 1260 ; .. :) on the shaft ( 1118 ; 1218 ; ...) of the tool holder is provided.