DE202011050262U1 - Clamping device for a workpiece or tool - Google Patents

Abstract

Clamping device (2, 3) for clamping a workpiece or tool, a) the clamping device comprising at least one clamping sleeve (5) which surrounds an axis (A) and at least one with respect to the axis (A) coaxial to the clamping sleeve (5) can be arranged, b) wherein the clamping sleeve (5) has a first sleeve section (6) and an axially offset second sleeve section (7) and an axially arranged between the first sleeve section (6) and the second sleeve section (7) has elastic deformation zone (8), c) wherein the clamping sleeve (5) has on a side facing the axis (A) or away from the axis (A) receiving clamping surfaces (51, 52) for receiving a workpiece or tool, the first Sleeve section (6) at least a first receiving clamping surface (51) and at least a second receiving clamping surface (52) are provided on the second sleeve section (7), d) the clamping sleeve (5) being attached to an egg ner at least two sides away from the side with the working clamping surfaces (51, 52) ...

Description

The invention relates to a clamping device for a workpiece or tool.

From the DE 36 03 301 C2 is a clamping device for workpieces or tools known with a provided with a cylindrical bore body and a concentric thereto arranged in diameter changeable cylindrical clamping sleeve with axially offset inner and outer Ringeinstichnuten and axially acting on a front end of the axially supported on the opposite side clamping sleeve clamping nut , The two ends of the clamping sleeve are designed as tapered sleeves with oppositely inclined outer cone surfaces. Each of the conical sleeves is externally associated with a trained as a loose guide ring countercone sleeve with correspondingly inclined inner cone surfaces. The clamping nut remote cone sleeve is slotted and thus softer and its outside associated guide ring is supported on the front side of a shoulder of the body. The clamping nut facing the conical sleeve is not slotted and the associated guide ring is disposed within the thread of the clamping nut and the mating thread on the base body and its inner cone region is axially displaceable relative to the outer cone portion of the associated tapered sleeve. When introducing a clamping force on the clamping screw closes first by the slit softer remote cone sleeve. Subsequently, an exact alignment of the clamped tool (or workpiece) is achieved under stronger axial tension of the clamping sleeve central portion, which is additionally improved by the front unslotted cone sleeve. The guide ring between the clamping nut and unslotted tapered sleeve can absorb inaccuracies in the thread and corresponding distortions in the clamping nut.

The DE 34 06 638 C2 discloses an elastic clamping sleeve for profile clamping a body. The clamping sleeve is formed by meandering groove grooves and composed of two outer coils and a plurality, in particular two, clamping elements, each with an inner stretch ceiling two webs and an outer stretch ceiling, each circulating closed. At the outer stretch ceilings are distributed around the circumference symmetrically distributed several thickened profile elevations formed, which form the clamping surfaces.

The object of the invention is to provide a new clamping device.

This object is achieved according to the invention with the features of claim 1. Advantageous embodiments and further developments according to the invention will become apparent from the dependent claims The clamping device according to claim 1 is provided for clamping a workpiece or tool and comprises at least one clamping sleeve which surrounds an axis (Or: extending through an axis) and at least one with respect to the axis coaxial with the clamping sleeve arranged or arranged (or: also surrounding the axis) counter-clamping body (or: base body, body). The clamping sleeve comprises or is subdivided into a first sleeve section and an axially offset second sleeve section and an axially between the first sleeve section and the second sleeve section disposed elastic deformation zone (or: deformation section, Dehnzone or section, spring section). For receiving a workpiece or a tool, the clamping sleeve has on a side facing away from the axis or on the side facing away from the axis on the first sleeve portion at least a first receiving clamping surface and on the second sleeve portion at least a second receiving clamping surface. On a side facing away from the side with the working clamping surfaces (or: opposite) side, the clamping sleeve on the first sleeve portion at least a first working clamping surface and on the second sleeve portion at least a second working clamping surface, said at least two axially to the axis offset from each other arranged first and second working clamping surfaces are each inclined to the axis in the same direction of inclination by one inclination angle. The counter-clamping body now has at least two corresponding to the working clamping surfaces of the clamping sleeve or associated and axially offset from each other to the axis work counter-clamping surfaces, wherein the counter-work surfaces are each inclined to the axis in the same direction of inclination by the same inclination angle as the corresponding work clamping surfaces and the mutually corresponding work clamping surfaces and the work counter-surfaces in pairs in sliding contact (or: in slide bearing) are brought or can be brought. Thus, the clamping sleeve and the counter-clamping body in an axial clamping movement axially to the axis against each other displaced or movable, wherein at least part of the axial clamping movement, the corresponding work clamping surfaces and work counter-clamping surfaces slide on each other.

An axial travel of the first sleeve section now corresponds (substantially) to the sum of the axial travel of the second sleeve section and an axial deformation path (or deformation length) in the deformation zone during the axial clamping movement. If, therefore, a different axial travel of the first sleeve section to the axial path of the second sleeve section occurs or is set, then this becomes axial path difference is compensated or compensatable by an axial deformation path (or strain length) in the deformation zone.

It should be noted here that the term clamping sleeve is understood here in a general sense and includes any clamping body or each clamping body assembly surrounding the axis in any form or with an arbitrarily shaped wall, the axis at least predominantly, preferably completely or closed or encloses and inside at least partially hollow or is seen with a cavity and axially seen at least on one side, preferably on both sides, at least partially open to the outside. Thus, the term clamping sleeve also includes, without limitation of generality, bodies having at least predominantly cylindrical and / or shouldered and / or tapered and / or threaded inner and / or outer surfaces, and in particular also clamping bushes and collets and sleeve-like clamping inserts. Any interpretations of the term tension sleeve which are limiting in the jargon are therefore irrelevant.

To further explain the invention, reference will now be made to the drawings, in which embodiments of jigs are illustrated without limitation thereto. In each case show in a schematic representation

1 a part of a first embodiment of a tensioning device in which an elastic stretching zone with a meander spaced from the workpiece, in a longitudinal section,

2 an enlarged portion of the clamping device according to 1 in a top and bottom perspective view,

3 a second embodiment of a tensioning device, in which an elastic stretching zone with a meander is close to the workpiece, in a longitudinal section,

4 a third embodiment of a tensioning device, in which a two-meander elastic expansion zone is spaced from the workpiece, in a longitudinal section,

5 a fourth embodiment of a tensioning device, in which an elastic stretch zone with two meanders is close to the workpiece, in a bottom and top perspective view and

6 a schematic diagram for explaining the operation of the tensioning device in the not yet tensioned state,

7 a further schematic diagram for explaining the operation of the tensioning device in the backward tensioned state,

8th a further schematic diagram for explaining the operation of the tensioning device in the rear and front tensioned state and

9 a further schematic diagram for explaining the operation of the tensioning device in the rear and front tensioned state with further increased clamping force front.

In the 1 to 9 are mutually corresponding parts and sizes provided with the same reference numerals.

All shown, with 2 designated clamping devices have a circumferential axis A around a clamping sleeve 5 and a likewise sleeve-shaped counter-clamping body 4 , which can also be referred to as a base body or body, within the clamping sleeve 5 and one within the counter-clamping body 4 arranged clamping bodies (or: drivers, clamping bolts, tension bolts) 3 on. The axis A forms an axis of rotation of the clamping device 2 with the clamped workpiece or tool, in particular for material processing, preferably in a machine tool.

In the embodiment according to 1 and 2 is the clamping body 3 with a thread 34 in an in 1 only indicated axial traction device 14 screwed in, with a polyhedron 33 at its free end to engage a screwdriver. Through this or another coupling to an axial traction device 14 at a rear side of the tensioner 2 , which is usually the side to the machine or to the rotary drive, is the clamping body 3 axially adjustable by a maximum free axial clamping stroke XS, wherein the pulling direction Z is shown with an arrow from right to left and represents the direction of the axial clamping movement.

The clamping body 3 lies with a shoulder, a flange or an at least partially annular stop surface 38 on a counter-attack surface 58 in a first sleeve section 6 the clamping sleeve 5 and thus takes the clamping sleeve 5 in the first sleeve section 6 in its axial movement in the pulling direction Z with. After axially passing through the maximum clamping stroke XS, the clamping body strikes 3 with a shoulder, a flange or an annular abutment surface 37 on a counter-attack surface 47 of the counter-clamping body 4 at. In the area of the counter-attack surface 47 is outside on the counter-clamping body 4 a feather key 17 introduced, in particular for supporting the Mounting the clamping sleeve 5 , A circlip 23 secures the clamping body 3 opposite the clamping sleeve 5 before pulling out by more than the maximum provided clamping stroke x. An O-ring 24 seals the clamping body 3 against the clamping sleeve 5 from.

The clamping sleeve 5 comprises in preferably one-piece training seen in the pulling direction Z, in 1 and 2 from right to left, the already mentioned first sleeve section 6 and then an axially (with respect to the axis A) offset second sleeve portion 7 on, as well as between the two sleeve sections 6 and 7 arranged elastic deformation zone 8th (or: an elastic intermediate section 8th ).

In the first sleeve section 6 includes the clamping sleeve 5 a radially inwardly (with respect to the axis A) and at a first inclination angle β1 against the pulling direction Z to the axis A inclined towards the first working clamping surface 61 resting on a correspondingly inclined outer work counter-clamping surface 41 of the counter-clamping body 4 is slidably mounted, and an outer first receiving clamping surface 51 at which the workpiece 1 from the outside.

In the second sleeve section 7 includes the clamping sleeve 5 a radially inner lying and at a second inclination angle β2 against the pulling direction Z to the axis A down inclined second working clamping surface 71 resting on a correspondingly inclined outer second counter-clamping surface 42 of the counter-clamping body 4 is slidably mounted, and an outer second receiving clamping surface 52 at which the workpiece 1 from the outside.

Optionally, these inclination angles β1 and β2 of the work clamping surfaces 61 and 71 and the associated work clamping surfaces 41 and 42 be the same, ie β1 = β2.

However, they are preferably different, wherein the angle of inclination β1 of the first working clamping surface 61 preferably smaller than the inclination angle β2 of the second working clamping surface 71 is selected, ie β1 <β2. The difference β2 - β1 of these angles should generally be between 1 to 5 degrees, preferably between 2 to 4 degrees. The values of the angles of inclination β1 and β2 measured relative to the axis A or an axis parallel thereto are expediently between 8 and 20 degrees, preferably between 10 and 17 degrees. According to the illustrated embodiments, the inclination angle β1 is about 12 degrees, while the inclination angle β2 is 15 degrees without loss of generality.

The clamping surfaces 51 and 52 are in their shape to the inner surface of the workpiece 1 adapted and formed in the embodiments at least predominantly as substantially cylindrical surfaces with respect to the axis A without inclination to this.

When viewed axially of the axis A between the two sleeve sections 6 and 7 arranged elastic deformation zone 8th it may in particular be at least one bellows-like or corrugated or meandering or zigzag-shaped structure which is preferably integral with the two sleeve sections 6 and 7 and / or consists of the same material as these.

The elastic deformation zone 8th the clamping sleeve 5 has in the illustrated embodiments, a bellows or meandering material reduction, wherein in 1 to 3 a simple meander and in 4 and 5 a double meander are shown.

In 1 to 3 are two cylindrical inner webs 83 via an inner slot 82 axially separated from each other, around the one outer web 81 running, in turn, from two outer slots 84 is limited axially on both sides.

An outer surface 54 of the outer walkway 81 is in the embodiment according to 1 and 2 radially inward lying as the two receiving clamping surfaces 51 and 52 arranged and the workpiece 1 is not on this outer jetty 81 on.

In 3 is the outer surface 53 of the outer walkway 81 radially further out and at substantially the same radius as the two receiving clamping surfaces 51 and 52 arranged and as well as this as a further receiving clamping surface from the inside of the workpiece 1 at.

The clamping body 3 is with a cylindrical outer surface 30 on a correspondingly formed cylindrical inner surface 40 of the counter-clamping body 4 axially slidably mounted to reduce influences of tilting moments.

In the 4 is different from 1 and 2 the elastic deformation zone 8th with two parallel outer webs 81 axially between each two outer slots 84 lie and three inner bars 83 , between which each axially an inner slot 82 lies, educated. The outer surfaces 55 the outer bars 81 are here from the workpiece 1 again spaced as in 2 and the workpiece 1 is thus again only on the receiving clamping surfaces 51 and 52 created from the outside.

In 5 are again, as in 3 , the outer bridges 81 displaced radially outwards and form receiving clamping surfaces 54 and 55 for the workpiece 1 out, on which the workpiece 1 rests.

A radius at which the conical first counter-work surface 41 of the counter-clamping body 4 axially as seen from the front, is indicated in the figures with r1 and a radius at which this first work counter-clamping surface 41 stops with r2. The first work clamping surface 41 increases in the pulling direction Z from the radius r1 to the radius r2 in linear dependence on the axial coordinate x according to the inclination angle β1. The cylindrical outer surface 43 of the counter-clamping body 4 then essentially stays on radius r2. When looking at the outside surface 43 axially adjoining second work counter-clamping surface 42 of the counter-clamping body 4 then takes in the pulling direction Z of the radius of the counter-clamping body 4 from the radius r2 back to the larger radius r3 in a linear manner according to the inclination angle β2.

The operation of the clamping device 2 according to the invention in the illustrated embodiments may be described as follows:
By means of the drawbar 14 becomes the clamping body 3 pulled in the pulling direction Z. The clamping body 3 lies with an annular shoulder or a flange or a stop surface 38 at a corresponding counter stop surface 58 at the clamping sleeve 5 on, so that in an axial pulling movement in the pulling direction Z of the clamping body 3 over the stop surfaces 38 and 58 the clamping sleeve 5 axially entrains in the pulling direction Z and the clamping sleeve 5 thus relative to the counter-clamping body 4 moved axially. This axial movement is limited to the maximum clamping stroke XS, in which the stop surface 37 of the clamping body 3 at the counter stop area 47 of the counter-clamping body 4 strikes.

Thus, the clamping body 3 Shearing forces on the first sleeve section 6 exerted in the pulling direction Z, which thrust forces over the elastic deformation zone 8th also in the second sleeve section 7 be transmitted. In each case, a pairing move from a working clamping surface 61 or 71 the clamping sleeve 5 and an opposing work clamping surface 41 or 42 of the counter-clamping body 4 on the according to the inclination angle β1 or β2 inclined planes or cones against each other and the clamping sleeve 5 will be in both the first sleeve section 6 as well as in the second sleeve section 7 pressed radially outwards and thereby expanded. As a result, the receiving clamping surfaces, in particular 51 and 52 , the clamping sleeve 5 under a radial clamping force outwards against the workpiece 1 Press and tension this in stiction on the clamping sleeve 5 ,

The first sleeve section 6 and the second sleeve section 7 are now preferably designed so coordinated that the axial movement of the clamping sleeve 5 in the pulling direction Z relative to the counter-clamping body 4 , which remains axially at rest, causes the clamping sleeve 5 initially in the second sleeve section 7 is stretched radially outward and the second receiving clamping surface 52 in the second sleeve section 7 in frictional or adhesive contact with the workpiece 1 comes and immediately after the clamping sleeve 5 also in the first sleeve section 6 is stretched or stretched outwards and also the first receiving clamping surface 51 of the first sleeve section 6 in frictional contact with the workpiece 1 comes and the workpiece 1 stressed.

However, since in the illustrated embodiments, the second inclination angle β2 is greater than the first inclination angle β1, either by conscious adjustment as in the present case or randomly due to tolerances, the radial path would be greater and the generated radial clamping force in the same axial path second clamping surface pairing of working clamping surface 71 and the counter-work surface 42 with the larger inclination angle β2 smaller than in the first clamping surface pairing of working clamping surface 61 and counter work clamping surface 41 with the smaller inclination angle β1. The first sleeve section 6 would thus be in rigid coupling with the second sleeve portion 7 by the same axial path as the second sleeve section 7 move.

According to the invention, however, now different axial paths of the two sleeve sections 6 and 7 by compressing or compressing the elastic deformation zone 8th specifically approved.

The resulting different path differences (Δx3 in 7 ) can typically be in the range of a few hundredths of a millimeter, while the total maximum clamping stroke XS can be, for example, between 0.5 and 1 mm. So it's only about relatively small deformations in the deformation zone 8th , but still the training of the clamping sleeve 5 allow only with the different inclination angles β1 and β2. It should in particular the adhesion and the clamping action in the rear second sleeve section 7 enter first, ie the workpiece 1 should be stretched from behind first. For this reason too, the angle of inclination β2 is greater than the front inclination angle β1.

In the illustrated embodiments, the clamping body 3 designed as a mandrel or clamping bolt, but he can also in a not shown embodiment as a clamping nut or other Means for axial entrainment of clamping sleeve 5 be educated. Furthermore, also the clamping sleeve 5 be axially stationary and the counter-clamping body 4 from the clamping body 3 taken along and axially relative to the clamping sleeve 5 to be moved.

Axial or longitudinal is the clamping sleeve 5 from several longitudinal slots 13 pulled through to facilitate their radial expansion, the longitudinal slots 13 relief wells 12 assigned.

The operation of the clamping device will be described below with reference to the graphs in 6 to 8th will be explained further. In 6 to 8th are the radius r of the axis of rotation A with an upwardly extending coordinate axis shown perpendicular to the axis of rotation A and the axial coordinate x with a parallel or coaxial to the axis of rotation A from right to left in the direction Z extending coordinate axis. The deformation zone 8th is in 6 to 8th schematically shown as a spring as an equivalent circuit diagram.

6 shows a not yet tensioned state of the tensioning device. Both sleeve sections 6 and 7 are still in this starting position of the workpiece to exciting 1 radially spaced. Thus, neither of the two sleeve sections yet 6 and 7 the clamping sleeve a clamping force to the outside on the workpiece 1 exercised.

The radius of the inner surface of the workpiece serving as a clamping surface 1 is again denoted by r4. In the 6 unsigned serving as receiving clamping surface outer surface of the first sleeve portion 6 is at a radius r60 and also not designated as a receiving clamping surface serving outer surface of the second sleeve portion 7 is located at a radius r70, where r60 <r70 <r4. That is, the first sleeve section 6 is with its receiving clamping surface in the untensioned state radially further from the workpiece 1 removed as the second sleeve portion 7 , because r4 - r60> r4 - r70 (1).

Inside is the first sleeve section 6 with its work clamping surface 61 on the work counter-clamping surface 41 of the counter-clamping body 4 slidably supported at the angle of inclination β1, wherein an exemplified lower point of the first sleeve portion 6 at the working clamping surface 61 according to 6 at an axial position x10 and an associated radius r10 = r (x10). The second sleeve section 7 on the other hand lies with its work clamping surface 71 at the angle of inclination β2 on the counter-work surface 42 of the counter-clamping body 4 up and sliding sliding. An example again picked out lower point of the second sleeve section 7 has according to 6 an axial position x20 and an associated radius r20 = r (x20). The difference between the inclination angles β2 and β1 is exaggerated for illustrative purposes.

Now acting in the pulling direction Z tensile force FZ on the first sleeve section 6 exercised. The tensile force FZ is over the elastic deformation zone 8th from the first sleeve section 6 practically without weakening in the second sleeve section 7 transferred, with the deformation zone 8th deformed or compressed. The tensile force FZ thus acts within the clamping sleeve as a compressive force and moves the second sleeve section 7 axially in the x direction or pulling direction Z, until the outer surface of the second sleeve section 7 on the workpiece 1 comes to rest and the workpiece 1 begins to tension, so a clamping force on the workpiece 1 from the inside, the first sleeve section 6 but not yet the workpiece 1 stressed. Then the second sleeve section moves 7 axially practically no longer. With a correspondingly increased tensile force FZ '> FZ, the first sleeve section moves 6 after, until the first sleeve section 6 the workpiece 1 stressed. A further increase in the tensile force to a value FZ ''> FZ 'only causes a stronger clamping force F1'> F1 on the first sleeve section 6 ,

7 shows now starting from the unstressed initial state of 6 a next state in which the second sleeve portion 7 the workpiece 1 already tense, the first sleeve section 6 but not yet the workpiece 1 spans, so it is not yet attached to this.

There is a tensile force FZ as axial clamping force on the first sleeve section 6 exercised in the direction of pull Z. The lower point of the first sleeve section 6 has moved due to the tensile force FZ of the axial position x10 with the radius r10, so the coordinate point (x10, r10) to a new point (x11, r11) with the axial position x11 and the radius r (x11) = r11.

The axial path difference Δx1 = x11-x10 thus leads to the radial difference (or: deflection or infeed) Δr1 = r11-r10, wherein owing to the oblique plane or wedge surfaces at the angle of inclination β1: Δr1 = Δx1 · tanβ1 (2)

By the same radial difference Δr1 has according to 7 the outer surface of the first sleeve portion 6 across from 6 Moves from a radius r60 to a radius r61 with Δr1 = r61 - r60. However, the radius r61 does not yet correspond to the radius r4 of the workpiece 1 ie the first sleeve section 6 is not yet in contact with the workpiece 1 and thus can not stretch it.

The tensile force FZ also causes an elastic deformation or compression of the deformation zone 8th by an axial distance Δx3 until the elastic restoring force in the deformation zone 8th , which according to Hooke's law, is the product of spring constant K of the elastic deformation zone 8th and axial deflection, equal to the tensile force FZ is, ie balance of forces in the deformation zone 8th prevails according to: FZ = K · Δx3 (3)

The second sleeve section 7 Therefore, by the tensile force FZ only a smaller axial path Δx2 = Δx1 - Δx3 <Δx1 (4) moved axially, as in 7 you can see.

The lower point of the second sleeve section 7 was thus, as in 7 shown from the original point (x20, r20) according to FIG 6 to a new point (x21, r21) according to 7 with the axial position x11 and the radius r (x21) = r21, where for the axial distance Δx2 = x21 - x20.

The radial difference (or: deflection or infeed) Δr2 = r21-r20 is with the axial path Δx2 = x21-x20 of the second sleeve section 7 about the relationship Δr2 = Δx2 · tanβ2 (5) connected.

So if according to 6 the first sleeve section 6 at the lower point (x10, r10) is the second sleeve section 7 at the lower point (x20, r20) and when the first sleeve section 6 to the lower point (x11, r11) has moved, there is the second sleeve portion 7 at the point (x21, r21).

The tensile force FZ is now in 7 chosen so large that the second sleeve section 7 outside in contact with the workpiece 1 comes, so outside the radius of the second sleeve section 7 from the radius r70 in 6 has grown to the radius r71, which in turn is the radius r4 of the workpiece 1 equivalent. It therefore applies to the radial difference Δr2 = r71 - r70 = r4 - r70 (6) as an outer radial stroke. As you can approximate the second sleeve section 7 can emanate from a rigid body, deforms this radially imperceptible and it builds due to the plant to the workpiece 1 a clamping force - F2, which in the parallelogram in 7 is illustrated.

As a result of the tensile force FZ arises when planting the second sleeve section 7 on the workpiece 1 to the outside and at the same time on the counter-clamping body 4 inward in rigid coupling to the inclined working clamping surface 71 a radially directed force F2, which in 7 to 9 is shown as radially inwardly acting force, but because of the third Newton's axiom actio = reactio also on the outer surface of the second sleeve portion 7 outward as a clamping force - F2 (the minus sign vectorically illustrates the direction reversal) on the workpiece 1 acts.

The radial clamping force F2 of the second sleeve section 7 is linked in terms of amount with the tensile force FZ as follows: F2 = FZ / tanβ2 (7)

In 8th a state is shown in which the tensile force on the first sleeve section 6 was further increased to a clamping force FZ '> FZ, in which the first sleeve section 6 has been moved axially and radially so far that it is just on the workpiece 1 is present and this begins to tighten.

The first sleeve section 6 was thus moved by the clamping force FZ 'by an additional axial displacement .DELTA.x1', which corresponds to an additional radial delivery .DELTA.r3, so that now the radius of the receiving clamping surface assumes the value r62, the radius r4 of the workpiece 1 corresponds, so r62 = r4. It applies again: Δr3 = Δx1 '· tanβ1 (8) for the additional paths Δx1 'and Δr3 of 7 to 8th ,

The lower point of the first sleeve section 6 has moved from the coordinate point (x11, r11) to the new coordinate point (x12, r12), where x12 - x11 = Δx1 'and r12 - r11 = Δr3.

For the entire paths x12 - x10 = Δx1 '' = Δx1 + Δx1 'and r12- r10 = Δr1 + Δr3 from the position of the first sleeve section 6 in 6 to the position in 8th applies: Δr1 + Δr3 = r4 - r60 (9) and Δr1 + Δr3 = Δx1 "'tanβ1 = = (Δx1 + Δx1') · tanβ1 (9 ')

It builds now with fitting first sleeve section 6 also in this a clamping force F1, which in 8th is again shown in a parallelogram of forces with the tensile force FZ '. F1 = FZ '/ tanβ1 (10)

Since the second sleeve section 7 can not move axially in his cocked state, this remains according to 8th at his already in 7 reached axial and radial position (x21, r21) and r71 = r4 stand.

The two sleeve section 6 and 7 have therefore moved closer to each other, wherein the axial path difference Δx1 'of the deformation zone 8th is recorded, so this is further pressed together elastically or compressed.

The axial shortening or the axial deformation path of the deformation zone 8th is now total Δx3 '= Δx1 "-Δx2 (11)

For those on the deformation zone 8th transferred, acting as a compressive force tensile force FZ 'applies: FZ '= K · Δx3' = K · Δx3 + K · Δx1 '= FZ + K · Δx1' (12)

Since the axial force FZ 'relative to the force FZ in 7 ie the additional elastic force K · Δx1 'due to the additional elastic deformation Δx1' of the deformation zone 8th has increased, also the clamping force F2 'in the second sleeve portion 7 increased compared to the original clamping force F2, namely according to F2 '= FZ' / tanβ2 = (K * Δx3 ') / tanβ2 = FZ / tanβ2 + (K * Δx1') / tanβ2 = F2 + (K * Δx1 ') / tanβ2 (13)

The clamping force on the second sleeve section 6 now remains at this value F2 'and is no longer increased, since both sleeve sections 6 and 7 on the workpiece 1 abut and axially unable to move and thus also the deformation zone 8th can not be further compressed and / or no further force increase more of the first sleeve section 6 on the second sleeve section 7 transfers. The of the deformation zone 8th absorbed force FZ '(and correspondingly the mechanical potential energy) is practically in the deformation zone 8th elastically stored and holds the clamping force F2 'on the second sleeve portion 7 upright, which also increases the tensile force on the first sleeve section 6 not increased anymore.

Because of the smaller angle β1 <β2 and the sequence of tensioning effects in the sleeve sections 6 and 7 is the clamping force F1 in the first sleeve section 6 greater than the clamping force F2 'in the second sleeve section 7 , wherein the angular difference and thus the force difference between F1 and F2 'in 8th is shown slightly exaggerated.

Now if you put the traction on the first sleeve section 6 further increased, only increases the clamping force on the first sleeve section 6 but not on the second sleeve section 7 ,

9 shows, starting from 8th , am on the workpiece 1 tense first sleeve section 6 such a situation with one opposite 8th again increased tensile force FZ ''> FZ 'or FZ''=FZ' + .DELTA.FZ 'with a not shown additional force .DELTA.FZ', the greater clamping force F1 '= FZ''/ tanβ1 = FZ' / tanβ1 + ΔFZ '/ tanβ1 (14) zeitigt. As in 9 shown, but remains the clamping force F2 '= FZ' / tanβ2 on the second sleeve section 7 same as in 8th , In addition, change in 9 across from 8th the axial paths no longer, so it is still the equation (11). In the second sleeve section 7 the clamping force is not increased, since both sleeve sections 6 and 7 on the workpiece 1 abut and no longer move axially and thus also the deformation zone 8th can not be squeezed any further. The of the deformation zone 8th absorbed force FZ '(and correspondingly the mechanical potential energy) is practically in the deformation zone 8th stored elastically and holds the clamping force on the second sleeve portion 7 upright, even after striking or concern also the first sleeve section 6 ,

From the above relations or equations (2) to (14), the following equations for the radial tension forces in the finished or finally tensioned state of the tensioning device can be obtained 9 put up:

The final tension F2 'in the second sleeve section 7 results as: F2 '= (K / tanβ2) · ((r4-r60) / tanβ1- (r4-r70) / tanβ2) (15)

For the final tensioning force F1 'in the first sleeve section 6 gives the derivation: F1 '= (K / tanβ1) * ((r4-r60) / tanβ1- (r4-r70) / tanβ2) + ΔFZ' / tanβ1 (16)

A few special cases will shed light on these equations (15) and (16):

Special case 1:

Equal tilt angle β1 = β2 = β F2 '= (K / tan ² β) * (r70-r60) (15') F1 '= (K / tan ² β) * (r70-r60) + ΔFZ' / tanβ (16 ')

It can also be seen here in comparison with the equations (15) and (16) that by an appropriate adaptation of r60 and r70 and / or K intentional or even unintentional deviations or tolerances of the two inclination angles β1 and β2 can be at least partially compensated.

Special case 2:

Same radial distances r4 - r60 = r4 - r70 = Δr0 F2 '= (K / tanβ2) · Δr0 · (1 / tanβ1-1 / tanβ2) (15 ") F1 '= (K / tanβ1) · Δr0 · (1 / tanβ1-1 / tanβ2) + + ΔFZ' / tanβ1 (16 '')

For a workpiece 1 with different inner radii, z. B. r4 at the first sleeve portion 6 and r5 in the second sleeve portion, in equations (15) to (15 '') and (16) to (16 ''), the term r4-r70 must be replaced with r5-r70, and if necessary, the external radii r60 and r70 in the untensioned state or to adjust the clamping strokes accordingly. But there is no fundamentally different view.

• – anfänglicher radialer Abstand r4 – r60 des ersten Hülsenabschnitt 6 vom Werkstück 1
• – anfänglicher radialer Abstand r4 – r70 oder r5 – r70 des zweiten Hülsenabschnitts 7 vom Werkstück 1
• – Federkonstante K der Verformungszone 8
• – Neigungswinkel β1 am ersten Hülsenabschnitt 6
• – Neigungswinkel β2 am zweiten Hülsenabschnitt 7

The relationships (2) to (16 '') set out here thus permit adjustment of the clamping sequence and the radial clamping forces and axial clamping strokes in the two sleeve sections of the clamping sleeve for a workpiece or tool to be clamped by defining the five most important input parameters:

• - Initial radial distance r4 - R60 of the first sleeve portion 6 from the workpiece 1
• - Initial radial distance r4 - r70 or r5 - r70 of the second sleeve portion 7 from the workpiece 1
• - Spring constant K of the deformation zone 8th
• Inclination angle β1 at the first sleeve section 6
• Inclination angle β2 at the second sleeve section 7

In particular, different angles of inclination β1 and β2 can also pass through the deformation zone 8th be practically balanced. In other words, a larger axial travel in the first sleeve section 6 nevertheless only leads to a smaller axial travel in the second sleeve section 7 because the deformation zone 8th receives a portion of the axial path, so that the second sleeve portion 7 axially not moved as far as the first sleeve section 6 and thus, despite the different inclination angles β1 and β2, the second sleeve portion 7 before the first sleeve section 6 with the workpiece 1 comes into contact and this tension.

The parts of the clamping device are preferably made of steel materials. The clamping device is suitable for clamping inside hollow workpieces or tools for rotation in material processing, in particular machining. But it is also possible in principle to reverse the clamping direction radially and clamp a workpiece or tool inside, for example, instead of the clamping body 3 , in which case, for example, a clamping nut can be used for clamping inwards.

Furthermore, at least the clamping surfaces can be provided with a sliding friction-reducing layer. For this layer, a material can be chosen which acts as a diffusion protection and / or a protection against Kaltpressverschweißung between the adjacent parts.

LIST OF REFERENCE NUMBERS

1

workpiece

2

jig

3

tensioning body

4

Against tension body

5

clamping sleeve

6

first sleeve section

7

second sleeve section

8th

elastic deformation zone (meander)

11

ring groove

12

relief well

13

longitudinal slot

14

drawbar

15

stop part

16

stop surface

17

Adjusting spring

18

fixing screw

23

circlip

24

O-ring

30

outer surface

33

Internal polygon

34

thread

37, 38

stop surface

40

palm

41, 42

Working against clamping surfaces

43

outer surface

47

Thrust face

51, 52, 53

Recording clamping surfaces

54

outer surface

58

Thrust face

61

Work clamping surface

71

Work clamping surface

81

outer web

82

interior slot

83

inner web

84

outside slot

A

axis of rotation

r1, r2

radius

r3, r4

radius

XS

clamping stroke

Z

tensile direction

β1

first inclination angle

β2

second inclination angle

x10, x11

axial position

x20, x21

axial position

Δx1, Δx1 '

axial way

Δx1 ", Δx2

axial way

Δx3, Δx3 '

axial way

Δr1, Δr2

radial deflection

Δr3

radial deflection

r10, r11

radius

r20, r21

radius

r60, r61

radius

r70, r71

radius

F1, F1 '

tension

F2, F2 '

tension

FZ, FZ ', FZ' '

traction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3603301 C2 [0002]
• DE 3406638 C2 [0003]

Claims (19)

Clamping device ( 2 . 3 ) for clamping a workpiece or tool, a) wherein the clamping device at least one clamping sleeve ( 5 ), which surrounds an axis (A), and at least one with respect to the axis (A) coaxial with the clamping sleeve ( 5 ) arranged or arranged counter-clamping body ( 4 ), b) wherein the clamping sleeve ( 5 ) a first sleeve section ( 6 ) and an axially offset second sleeve section (( 7 ) and an axially between the first sleeve section ( 6 ) and the second sleeve section ( 7 ) arranged elastic deformation zone ( 8th ), c) wherein the clamping sleeve ( 5 ) on one of the axis (A) facing away or from the axis (A) facing away receiving clamping surfaces ( 51 . 52 ) for receiving a workpiece or tool, wherein at the first sleeve portion ( 6 ) at least a first receiving clamping surface ( 51 ) and at the second sleeve section ( 7 ) at least one second receiving clamping surface ( 52 ) are provided, d) wherein the clamping sleeve ( 5 ) on one side of the working clamping surfaces ( 51 . 52 ) opposite side at least two axially to the axis (A) offset from each other arranged work clamping surfaces ( 61 . 71 ) each inclined to the axis (A) in the same direction of inclination by a respective inclination angle (β1, β2), wherein at the first sleeve portion ( 6 ) at least a first working clamping surface ( 61 ) and at the second sleeve section ( 7 ) at least one second working clamping surface ( 71 ) are provided, c) wherein the counter-clamping body ( 4 ) at least two axially to the axis (A) offset from each other, to the working clamping surfaces ( 61 . 71 ) of the clamping sleeve ( 5 ) corresponding work counter-surfaces ( 41 . 42 ), wherein the counter-work surfaces ( 41 . 42 ) in each case to the axis (A) in the same direction of inclination by the same inclination angle (β1, β2) as the corresponding work clamping surfaces ( 61 . 71 ) are inclined and the mutually corresponding work clamping surfaces ( 61 . 71 ) and the work counter-surfaces ( 41 . 42 ) are brought into sliding contact with each other in pairs or can be brought, d) wherein the clamping sleeve ( 5 ) and the counter-clamping body ( 4 ) in an axial clamping movement under the action of an axial clamping force axially relative to the axis (A) are mutually displaceable, wherein at least a portion of the axial clamping movement, the corresponding work clamping surfaces ( 61 . 71 ) and work counter-surfaces ( 41 . 42 ) on the axial clamping movement of the axial path (.DELTA.x1, .DELTA.x1 ', .DELTA.x1'') of the first sleeve portion ( 6 ) substantially the sum of the axial distance (Δx2) of the second sleeve portion ( 7 ) and an axial deformation path (Δx3, Δx3 ') in the deformation zone (FIG. 8th ) corresponds. Clamping device according to Claim 1, in which, during the axial clamping movement, a radial infeed (Δr1, Δr2) of the first sleeve section (FIG. 6 ) and the second sleeve section ( 7 ) to the workpiece ( 1 ) or tool, wherein the radial feed (.DELTA.r1, .DELTA.r2) of the first sleeve portion ( 6 ) or the second sleeve section ( 7 ) to the workpiece ( 1 ) or tool corresponds to the product of its axial travel (Δx1, Δx2) and the tangent of the associated inclination angle (β1, β2). Clamping device according to claim 2, in which the radial feed of the first sleeve section ( 6 ) to the workpiece ( 1 ) or tool in the axial clamping movement is greater than the radial delivery of the second sleeve portion ( 7 ). Clamping device according to one of the preceding claims, wherein the radial on the workpiece ( 1 ) or tool-acting clamping force (F2 ') of the second sleeve section ( 7 ) equals the quotient of the product of the axial spring constant (K) of the deformation zone ( 8th ) corresponds to the axial deformation path (Δx3 ') on the one hand and the tangent of the second inclination angle (β2) on the other hand. Clamping device according to one of the preceding claims, wherein the radial on the workpiece ( 1 ) or tool-acting clamping force (F1 ') of the first sleeve section (FIG. 6 ) at least as large or larger than the quotient of the product of the axial spring constant (K) of the deformation zone ( 8th ) with the axial deformation path (Δx3 ') on the one hand and the tangent of the first inclination angle (β1) on the other hand. Clamping device according to one of the preceding claims, wherein the radial on the workpiece ( 1 ) or tool-acting clamping force (F1 ') of the first sleeve section (FIG. 6 ) the sum of, firstly, the quotient of the product of the axial spring constant (K) of the deformation zone ( 8th ) corresponds to the axial deformation path (Δx3 ') on the one hand and the tangent of the first inclination angle (β1) on the other hand, and secondly to a quotient of an additional axial force (ΔFZ) and the tangent of the first inclination angle (β1). Clamping device according to one of the preceding claims, wherein the clamping force (F2 ') in the second sleeve section ( 7 ) is given by the following formula: F2 '= (K / tanβ2) · ((r4-r60) / tanβ1 - (r4-r70) / tanβ2) where K is the axial spring constant of the deformation zone ( 8th ), β1 is the first inclination angle at first sleeve section ( 6 ), β2 is the second inclination angle at the second sleeve section (FIG. 7 ), r4 - r60 is the radial distance between working clamping surface ( 61 ) at the first sleeve section ( 6 ) to the corresponding work counter-clamping surface ( 41 ) before tensioning or at the beginning of the axial movement or the axial travel and r4 - r70 is the radial distance of the working clamping surface ( 71 ) on the second sleeve section ( 7 ) to the corresponding work counter-clamping surface ( 42 ) before tensioning or at the beginning of the axial movement or the axial travel. Clamping device according to one of the preceding claims, wherein the clamping force (F1 ') in the first sleeve section ( 6 ) is given by the following formula: F1 '= (K / tanβ1) · ((r4-r60) / tanβ1- (r4-r70) / tanβ2) + + ΔFZ / tanβ1 where K is the axial spring constant of the deformation zone ( 8th ), β1 is the first inclination angle at the first sleeve section (FIG. 6 ), β2 is the second inclination angle at the second sleeve section (FIG. 7 ), r4 - r60 is the radial distance between working clamping surface ( 61 ) at the first sleeve section ( 6 ) to the corresponding work counter-clamping surface ( 41 ) before tensioning or at the beginning of the axial movement or the axial travel and r4 - r70 is the radial distance of the working clamping surface ( 71 ) on the second sleeve section ( 7 ) to the corresponding work counter-clamping surface ( 42 ) before tensioning or at the beginning of the axial movement or the axial travel and .DELTA.FZ is an additional axial force acting on the first sleeve portion ( 6 ) in the case of an already adjacent work clamping surface ( 61 ) and counter-work surface ( 41 ) acts. Clamping device according to one of the preceding claims, in which the angles of inclination (β1, β2) of the axially displaced working clamping surfaces ( 61 . 71 ) or work counter-surfaces ( 41 . 42 ) are the same. Clamping device according to one of the preceding claims, in which the angles of inclination (β1, β2) of the axially displaced working clamping surfaces ( 61 . 71 ) or work counter-surfaces ( 41 . 42 ) are different from each other. Clamping device according to Claim 10, in which the first inclination angle (β1) of the first working clamping surface (β1) 61 ) is smaller than the second inclination angle (β2) of the second work clamping surface ( 71 ), in particular by 1 to 5 degrees, preferably by 2 to 4 degrees. Clamping device according to one of the preceding claims, in which the angles of inclination (β1, β2) of the axially displaced working clamping surfaces ( 61 . 71 ) or work counter-surfaces ( 41 . 42 ) are between 8 and 20 degrees, preferably between 10 and 17 degrees. Tensioning device according to one of the preceding claims, in which the elastic deformation zone ( 8th ) has at least one bellows-like or corrugated or meandering or zigzag-shaped structure. Tensioning device according to one of the preceding claims, in which the elastic deformation zone is integral with the two sleeve sections ( 6 and 7 ) is formed and / or made of the same material as this. Clamping device according to one of the preceding claims, in which the axial clamping force (FZ, FZ ', FZ'') on the first sleeve portion ( 6 ) of the clamping sleeve ( 5 ) acts. Clamping device according to one of the preceding claims, in which, preferably within the counter-clamping body ( 4 ), a clamping body ( 3 ) is arranged, which in a pulling direction (Z) in an axial movement, the clamping sleeve ( 5 ) against the counter-clamping body ( 4 ) or the counter-clamping body ( 4 ) with respect to the clamping sleeve ( 5 ) and / or the axial clamping force (FZ, FZ ', FZ'') on the first sleeve portion ( 6 ) of the clamping sleeve ( 5 ) exercises. Clamping device according to one of the preceding claims, wherein in the axial clamping movement, the first receiving clamping surface ( 51 ) of the first sleeve section ( 6 ) temporally after the second receiving clamping surface ( 52 ) of the second sleeve section ( 7 ) on the workpiece ( 1 ) or tool comes to rest and / or a radial clamping force on the workpiece ( 1 ) or exercise tool. Clamping device according to one of the preceding claims, wherein in the axial clamping movement and / or under the action of the axial clamping force first after passing through the maximum axial travel of the second sleeve portion ( 7 ) the second receiving clamping surface ( 52 ) of the second sleeve section ( 7 ) on the workpiece ( 1 ) or tool comes to rest or a dependent on the axial clamping force radial clamping force on the workpiece ( 1 ) or tool and then after passing through the maximum axial path of the first sleeve portion ( 6 ), the sum of the maximum axial travel of the second sleeve section ( 7 ) and the axial deformation path in the deformation zone ( 8th ), also the first receiving clamping surface ( 51 ) of the first sleeve section ( 6 ) on the workpiece ( 1 ) or tool comes to rest or a radial clamping force on the workpiece ( 1 ) or exercise tool. Clamping device according to one of the preceding claims, in which after the axial clamping movement and / or after passing through the maximum axial travel of the second sleeve portion ( 7 ) and after passing through the maximum axial path of the first sleeve portion ( 6 ) and / or if both the first receiving clamping surface ( 51 ) of the first sleeve section ( 6 ) as well as the second receiving clamping surface ( 52 ) of the second sleeve section ( 7 ) on the workpiece ( 1 ) or tool comes to rest or a radial clamping force on the workpiece ( 1 ) or tool exerts an additional increase (ΔFZ) on the first sleeve section ( 6 ) acting axial clamping force only the radial clamping force (F1 ') on the first sleeve portion ( 6 ), but not at the second sleeve section ( 7 ).

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