WO2017076921A1

WO2017076921A1 - Expansion chuck

Info

Publication number: WO2017076921A1
Application number: PCT/EP2016/076459
Authority: WO
Inventors: André Übele
Original assignee: Schunk Gmbh & Co. Kg Spann- Und Greiftechnik
Priority date: 2015-11-02
Filing date: 2016-11-02
Publication date: 2017-05-11
Also published as: DE102015118758B3

Abstract

The invention relates to an hydraulic chuck for securing a tool to a machine tool, comprising a main part (2) at the front end region of which a central seat (6) for a component to be clamped is provided. The seat (6) is surrounded ring-like by a pressure chamber (7) to which a hydraulic medium can be admitted, and between the seat and the pressure chamber (7) a wall that is closed on the side of the pressure chamber (7) and takes the form of a clamping portion (5a) is configured such that it is elastically deformable towards the inside when a pressure in the pressure chamber (7) increases. An intermediate sleeve (11) is inserted into the seat (6) and defines a central clamping bushing (13). The clamping portion (5a) and the intermediate sleeve (11) are of a single piece or integrally bonded together, although in the axially frontal end portion of the seat (6) there is no such connection between the component (5) defining the seat (6), and the intermediate sleeve (11).

Description

DESCRIPTION

expansion chucking

The present invention relates to a hydraulic tensioning device, in particular for fixing a tool to a machine tool, with a basic body defining a clamping axis, at the front end region of which a clamping region is formed with a central receptacle for a component to be clamped open to the front end surface of the main body, wherein the Recording of a pressurizable with a hydraulic pressure chamber is annularly surrounded and formed between the receptacle and the pressure chamber to the pressure chamber closed wall in the form of a clamping portion such that it is elastically deformable inwardly by an increase in pressure in the pressure chamber, and an intermediate sleeve, which is inserted into the receptacle and defines a central clamping bore. Furthermore, the invention relates to a Dehnspannbüchse and an intermediate sleeve, which are suitable for such a Dehnspanneinrichtung. Furthermore, the invention relates to a Dehnspannbüchsenanordnung consisting of a Dehnbüchse and an intermediate sleeve.

Dehnspanneinrichtungen the aforementioned type are known in different embodiments, for example from DE 20 201 1 103 20341 and DE 91 0982141 and are used in practice to a tool shank such as a drill or cutter shank or another component on the work spindle of a corresponding machine tool to fix. In the known Dehnspanneinrichtungen the clamping path is limited, so that the diameter of the receptacle on the one hand and on the other hand, the component to be clamped must be matched to one another.

In order to clamp with a Dehnspanneinrichtung also tools / components that have a much smaller diameter than the recording of Dehnspanneinrichtung, so-called. Intermediate bushings are often used in practice, which are inserted into the receptacle of the expansion sleeve to reduce the clamping diameter. These intermediate bushes have a cylindrical body with a central clamping bore, which has distributed over the outer periphery a plurality of radial slots which extend over the entire length of the intermediate sleeve. The slots serve to give the intermediate sleeve the required elasticity for transmitting the clamping forces.

Through the use of intermediate bushings, the range of application of the expansion chucks can be increased. However, efforts are being made to further improve the field of application of expansion jigs and, in particular, to securely clamp components of very small diameter.

Object of the present invention is therefore to design a Dehnspanneinrichtung of the type mentioned in such a way that even very small diameter can be stretched safely. Furthermore, a Dehnbüchse and an intermediate sleeve of such a Dehnspanneinrichtung be specified.

This object is achieved according to the invention in a Dehnspanneinrichtung of the type mentioned in that the clamping portion and the intermediate sleeve integrally formed or materially connected to each other and that in the axially forward end portion of the recording such a connection between the recording defining component and the intermediate sleeve does not exist. By creating a one-piece arrangement of the recording defining component and the intermediate sleeve, the Dehnspanneinrichtung is little dirt sensitive. In addition, a high precision can be achieved by a one-piece design. Furthermore, there are few loose components. Since the recording defining component and the intermediate sleeve integrally formed only in the region of the elastically deformable clamping portion or materially connected to each other, but in the axially forward end portion of the receptacle such a connection between the expansion sleeve and the intermediate sleeve does not exist, receives the intermediate sleeve in her front end portion of increased flexibility, with the result that also their tension travel increases and thus a relatively large torque is transferable. Furthermore, there is a high transverse rigidity. Finally, the required clamping depths of the tools are comparatively low.

Such increased flexibility can also be achieved if an annular gap open towards the front end face of the main body is provided in the axially front end section between the component defining the receptacle and the intermediate sleeve. In this case, a cohesive / firm connection between the component defining the receptacle and the intermediate sleeve in the region of the receptacle need not necessarily be present. It is then sufficient if the intermediate sleeve is used in the usual way in the expansion sleeve and is tightened on the expansion sleeve.

According to one embodiment of the invention, it is provided that the axially front end section of the receptacle extends as far as or into the tensioning section in order to achieve the desired flexibility in the front end section. The clamping section has a predetermined clamping diameter knife, with which the recording defining component comes into contact on the outside of the intermediate sleeve. In this case, the receptacle at its axially front end portion has a diameter which is larger than the clamping diameter to produce the desired annular gap in the region of the front end portion of the receptacle to the intermediate sleeve.

The clamping area with the clamping portion may be formed integrally with the main body. In particular, it is possible to produce the clamping region of the main body with the clamping section by means of a generative production method.

Alternatively, the clamping portion may be formed on a cylindrical expansion sleeve, which is used to form the pressure chamber in the Grundköper and defines the central receptacle. In this case, the clamping portion forms an axial portion of the cylindrical expansion sleeve. In this embodiment, the expansion sleeve may have at its front axial end portion a plan recess, through which the inner diameter is formed, which is greater than the clamping diameter.

In a manner known per se, a plurality of slots extending in the longitudinal direction of the intermediate bushing can be formed in the wall of the intermediate bushing.

According to a further embodiment of the invention, the hydraulic expansion chuck device of the type mentioned above may be characterized in that the intermediate sleeve is divided in its circumferential direction in intermediate sleeve segments which carry on its front side, in particular on its front end face, respectively, a clamping finger extending in the axial direction wherein the clamping fingers are each formed and / or have such a cross-section that their two in circumferential Direction considered ends on opposite sides, in particular on diametrically opposite sides of the clamping axis lie, wherein the one circumferential fixed end of the clamping fingers is connected to the associated intermediate sleeve segment and the opposite free end comes into contact with a component to be clamped.

The fact that the circumferentially opposite ends of the clamping fingers lie on opposite sides of the clamping axis or the clamping bore, the free ends, which come into contact with a component to be clamped, pushed apart when the can body is radially compressed with the result, in that, when the sleeve body is compressed, a component which is placed externally on the clamping fingers is tensioned. Alternatively, it is possible to insert into the enlarged clamping bore a component which is then stretched passively when the pressure chamber is relieved, so that the intermediate sleeve elastically deformed back. Accordingly, in particular part-circular clamping surfaces may be formed on the radially inner side and / or the radial outer side of the free ends of the clamping fingers. In particular, when components are to be clamped on the outside of the clamping finger, it is expedient if the clamping fingers protrude axially from the main body.

It can be provided that the clamping fingers each carry a holding finger at their axially front end surfaces, which are formed such that their outer surfaces and / or their inner surfaces lie on a common circle. The holding fingers can thereby have a smaller cross section relative to the clamping fingers, whereby the possibility is created to clamp very small components.

According to a preferred embodiment of the invention it is provided that the clamping fingers are formed bent, whereby you with the zugehö- Rigid intermediate sleeve segment fixed radially outward than its free end, and that the clamping fingers are arranged such that the free end of a clamping finger is encompassed by the fixed end of a circumferentially adjacent clamping finger. In this case, the cross section of the clamping fingers in the circumferential direction can taper towards the fixed ends and in particular be formed tapered.

In this embodiment, the clamping fingers are designed in the manner of petals, which partially embrace each other, whereby a compact design is achieved. It is essential that the clamping fingers are spaced from each other in the radial direction, so that sufficient space is available so that the clamping fingers can perform the desired clamping movements.

According to one embodiment of this embodiment, the intermediate sleeve is divided in its circumferential direction into three intermediate sleeve segments, each carrying a clamping finger. In this case, the clamping fingers preferably each extend over a circumferential region of 160 ° to 200 °, in particular of about 180 °.

With regard to further embodiments of the invention, reference is made to the dependent claims and the following description of embodiments with reference to the accompanying drawings. In the drawing shows

1 shows a first embodiment of a Dehnspanneinrichtung according to the present invention perspective view,

2 shows the front end portion of the Dehnspanneinrichtung of Figure 1 in an enlarged view, 3 shows the expansion chuck in front view,

4 shows the central portion of Figure 3 in an enlarged view,

FIG. 5 is a partially sectioned front view of the expansion chuck,

FIG. 6 shows the expansion chuck in section Vl-Vl from FIG. 5 in an enlarged view,

7 shows the front end region of the expansion chuck in section along the line VII-VII from FIG. 4, FIG. 8 shows an arrangement consisting of an expansion bushing with inserted intermediate bushing of the expansion chuck in a perspective view,

FIG. 9 shows the arrangement from FIG. 8 in a perspective view obliquely from the front,

10 shows the arrangement from FIG. 8 in a partially cutaway front view, FIG. 11 shows the arrangement in section along the line X1-X1 from FIG. 10,

12 shows the intermediate bushing of the expansion chuck in a perspective side view, FIG. 13 shows the intermediate bush in a perspective front view, 14 is a perspective view of a second embodiment of a stretching chuck device according to the invention; FIG. 15 is an enlarged view of the front end section of the stretch chuck of FIG. 14;

16 shows the expansion chuck of FIG. 14 in a partially sectioned front view, FIG.

17 shows the expansion chuck in section along the line XVII-XVII of FIG. 16, FIG.

FIG. 18 shows the expansion chuck of FIG. 14 in front view,

FIG. 19 shows the central section of FIG. 18 in an enlarged view,

FIG. 20 is a front view of the expansion chuck of FIG. 14 with the tool tensioned;

FIG. 21 shows the expansion device from FIG. 14 with a tensioned tool in a perspective side view, FIG. 22 shows the front end section of the expansion clamping device from FIG. 21 in a partially sectioned side view,

FIG. 23 shows the expansion chuck in section along the line FF from FIG. 22, FIG. 24 shows a perspective view of an arrangement comprising an expansion bushing with an inserted intermediate bushing of the tensioning tensioning device from FIG. 14, FIG. 25 shows the arrangement from FIG. 24 in a perspective view obliquely from the front,

FIG. 26 shows the arrangement from FIG. 24 in a partially cutaway front view,

FIG. 27 shows the arrangement in section along the line B-B from FIG. 26,

FIG. 28 shows the intermediate bush of the expansion chuck in a perspective side view,

FIG. 29 shows the intermediate sleeve in a perspective front view,

FIG. 30 shows a perspective view of a third embodiment of a tensioning clamping device according to the invention,

FIG. 31 is an enlarged view of the front end section of the expansion chuck of FIG. 30;

FIG. 32 shows a partially sectioned front view of the expansion-tensioning device from FIG. 30,

FIG. 33 shows the expansion chuck in section B-B from FIG. 32,

FIG. 34 the detail X of FIG. 32 in an enlarged view, 35 shows a longitudinal section through the front end region of the expansion chuck device from FIG. 30, FIG.

FIG. 36 shows the expansion chuck of FIG. 35 in front view,

FIG. 37 shows a representation of the expansion-tensioning device corresponding to FIG. 35 with a tensioned component,

FIG. 38 a perspective view of an arrangement comprising an expansion bushing with an inserted intermediate bushing of the tensioning tensioning device from FIG. 30,

FIG. 39 shows the arrangement from FIG. 38 in a perspective view obliquely from the front,

FIG. 40 shows the intermediate bushing of the expansion chip device in a perspective side view,

FIG. 41 shows the intermediate bushing from FIG. 40 in a perspective front view,

FIG. 42 is a perspective view of a fourth embodiment of a stretch-clamping device according to the invention with a tensioned component;

FIG. 43 is a perspective view of an arrangement comprising an expansion bushing with an inserted intermediate bushing of the tensioning tensioning device from FIG. 42; FIG. 44 shows the expansion chuck from FIG. 42 in a partially sectioned side view and FIG

Figure 45, the Dehnspanneinrichtung of Figure 44 in front view.

FIGS. 1 to 13 show a first embodiment of a hydraulic expansion chuck 1 according to the present invention. The hydraulic Dehnspanneinrichtung 1, which is formed here in the form of a Dehnspannfutters, has a clamping axis X defining body 2 made of a dimensionally stable material, at its left in Figure 1 rear end portion in a conventional manner a mounting cone 2a for clamping on a having rotationally driven work spindle of a machine tool. At the opposite front axial end of the main body 2, a connection shaft 3 is provided with a central axial bore 4, in which an expansion sleeve 5 is inserted. The expansion sleeve 5 defines a front end face of the main body 2 open towards the central receptacle 6 for a component to be clamped, usually the cylindrical shaft of a tool such as a drill or a milling cutter.

Between the expansion sleeve 5 and the main body 2, a pressure chamber 7 forming annular space is formed, which surrounds the receptacle 6 and is aligned coaxially thereto. The pressure chamber 7, whose axial length corresponds approximately to the required clamping portion 5a of the Dehnspanneinrichtung 1, is for receiving 6 out of the relatively thin wall of the expansion sleeve 5 and radially outwardly from the wall of the base body 2, the wall thickness by a multiple greater than the wall thickness the inner wall is limited. The pressure chamber 7 is connected via a Hydraulikmittelzuführkanal 8 with a formed in the base body 2 cylinder chamber 9 with an internal thread in connection, which is closed at its remote from the pressure chamber 7 side by a clamping screw 10.

The pressure chamber 7, the Hydraulikmittelzuführkanal and the cylinder chamber 9 are completely filled with a hydraulic fluid, which is displaced under pressure increase in the direction of the pressure chamber 7 when the clamping screw 10 is screwed into the base body 2.

In order to clamp with the Dehnspanneinrichtung 1 also shafts of tools whose diameter is much smaller than the pressure gauge of the receptacle 6, an intermediate sleeve 1 1 is inserted into the receptacle 6, which defines a clamping bore 13, in which a tool shank is inserted.

As can be seen in particular Figures 12 and 13, the intermediate sleeve 1 1 distributed along its outer periphery slits 14 in the form of grooves or grooves which extend from the outer surface of the intermediate sleeve 1 1 inwardly. The slots 14 extend over the entire length of the intermediate sleeve 1 1 in the longitudinal axis direction.

A total of six slots are provided, which are divided into three slot groups of two slots 14, which extend parallel to each other. At their inner ends, the mutually associated pairs of slots 14 are interconnected by a transverse slot 15, which in turn opens through a radial slot 16 in the clamping bore 13.

As FIG. 7 clearly shows, in the axially front end section of the receptacle 6 between the expansion bushing 5 and the intermediate bushing 11 a radial annular gap 17 which is open towards the front end surface of the main body 2 and which extends approximately over 20% to 30% of the axial length of the expansion sleeve 5 from its front end face approximately to the clamping section 5 a. In the region of this front end section 6, the expansion bushing 5 has an inner diameter which is greater than the inner diameter in the region of the clamping section 5 a. The formation of a radial annular gap 17 gives the intermediate sleeve 1 1 in its front end a high flexibility, with the result that also increases its clamping travel and thus a larger torque is transferable when the pressure chamber 7 by screwing the clamping screw 10 in the cylinder chamber. 9 subjected to a hydraulic pressure and thus the thin wall of the expansion sleeve 5 in the region of the clamping portion 5a is deformed inwardly, with the result that a radially inwardly directed pressure is exerted on the intermediate sleeve 1 1 to this against an inserted into the clamping bore 13 tool Press W and tighten the tool W in this way.

FIGS. 14 to 29 show a second embodiment of a tensioning clamping device according to the invention. This corresponds in its basic structure of the hydraulic expansion device described above. There are only differences in terms of the design of the intermediate sleeve 1 1. This is divided here in the direction of transition into three identically formed intermediate sleeve segments 12, which are each spaced by longitudinal slots 14 from each other. The intermediate sleeve segments 12 are materially connected to the expansion sleeve 5 in the region of the clamping section 5 a. In the front end portion of the receptacle 6, which extends here from the front end face of the expansion sleeve 5 to the clamping portion 5 a, there is no such a material connection in the non. Rather, here is an annular gap 17 between the expansion sleeve 5 and the intermediate sleeve 1 1 available. The intermediate sleeve segments 12 carry at their front end face in each case a clamping finger 12a, which protrudes axially from the front end face of the associated intermediate sleeve segment 12. As can be seen in particular from FIGS. 19 and 29, the clamping fingers 12a have a bow-shaped cross-section in such a way that they surround the central clamping bore 13 of the intermediate sleeve 11 and their circumferentially viewed ends on diametrically opposite sides of the clamping bore 13 / clamping axis X. lie. Here, in the circumferential direction, one fixed end of the clamping fingers 12a is connected to the associated intermediate sleeve segment, and the opposite free end comes into contact with a component to be clamped. For this purpose, a part-circular clamping surface is formed on the radial inner side of the free ends of the clamping fingers 12a.

The arrangement is made such that the clamping fingers 12a protrude axially from the main body 2. Specifically, the clamping fingers carry 12a at their axially front end surfaces in the region of the free ends of each holding fingers 12b of smaller diameter, the inner surfaces are formed as clamping surfaces which lie on a common circle. In the illustrated embodiment, the arcuate clamping fingers 12a engage around each other in the manner of petals, with their fixed end radially outward than their free end and the clamping fingers 12a are arranged such that in each case the free end of a clamping finger 12a from the fixed end of a circumferential direction adjacent clamping finger 12a is encompassed. It is essential that the clamping fingers 12a do not come into abutment in the radial direction, but are spaced apart from one another, so that a movement of the clamping fingers 12a in the radial direction is possible. In this case, the cross section of the clamping fingers 12a tapers towards the fixed ends and runs to a point. If pressure is applied to the pressure chamber 7 in this embodiment, this results in that the intermediate sleeve 1 1 is radially compressed, that is, the intermediate sleeve segments 12 are pressed inward. As a result, also held on the intermediate sleeve segments 12 clamping fingers 12a are pressed inwards with the result that their free ends and thus the retaining fingers 12b, which lie on the opposite side of the clamping bore 13, are pressed apart. If now a tool W is inserted into the clamping bore 13 and the pressure chamber 7 is relieved, so that the expansion sleeve 5 and the intermediate sleeve 1 1 elastically deform radially outward, the workpiece W in the clamping bore 13 by the elastic restoring force of Intermediate sleeve 1 1 - quasi passive - taut.

Alternatively, it is possible to actively tension a component W on the outside of the holding fingers 12b by fitting the component W on the holding fingers 12b and then pushing the holding fingers 12b apart by urging the pressure chamber 7. For this purpose, it makes sense to design the retaining fingers 12b in the manner of cylinder segments whose outer surfaces lie on a common circle, as is the case in the embodiment shown in FIGS. 30 to 44. Incidentally, this expansion chuck is constructed the same as the second embodiment shown in FIGS. 14 to 29. The holding fingers 12b are formed here small and positioned as far as possible at the free ends of the clamping fingers 12a, so that components with small inner diameters can be stretched.

Finally, FIGS. 42 to 45 show a fourth embodiment of a tensioning clamping device according to the invention. This differs from the previous embodiments in that the intermediate sleeve 1 1 is formed as a substantially cylindrical member, which in the region of the clamping portion 5 a is integrally connected to the expansion sleeve 5. In the front end portion of the receptacle 6 is provided between the expansion sleeve 5 and the intermediate sleeve 1 1 unlike the embodiments described above, no annular gap, but there is no material connection between the intermediate sleeve 1 1 and the expansion sleeve 5, but the components are here from each other separated.

LIST OF REFERENCE NUMBERS

1 expansion fixture

2 main body

2a fixing cone

3 connection shaft

4 axial bore

5 expansion sleeve

5a clamping section

6 recording

7 pressure chamber

8 hydraulic fluid supply channel

9 cylinder space

10 clamping screw

1 1 intermediate liner

1 1 a clamping section

1 1 b end section

12 pan bodies

12a bushes body segments

12b clamping fingers

12c holding fingers

13 clamping hole

14 slots

15 transverse slot

16 radial slot

17 Annular gap w Tool / component

X clamping axis

Claims

1. Hydraulic clamping device, in particular for fixing a tool to a machine tool, with a clamping axis (X) defining the base body (2), at its front end a clamping area with a front end face of the base body (2) open central receptacle (6) a component to be clamped is formed, the receptacle (6) being annularly surrounded by a pressure chamber (7) which can be acted upon by a hydraulic medium and a wall closed in the form of the pressure chamber (7) between the receptacle (6) and the pressure chamber (7) a clamping portion (5a) is formed such that it is elastically deformable inwardly by an increase in pressure in the pressure chamber (7), and an intermediate sleeve (1 1) which is inserted into the receptacle (6) and a central clamping bore (13) defined, characterized in that the clamping portion (5a) and the intermediate sleeve (1 1) are integrally formed or materially connected to each other and that in the axially front end portion of the receptacle (6) such a connection between the receiving member (6) defining the component (5) and the intermediate sleeve (1 1) does not exist.

2. Hydraulic clamping device, in particular for fixing a tool to a machine tool, with a clamping axis (X) defining the base body (2), at its front end a clamping area with a front end face of the base body (2) open central receptacle (6) a component to be clamped is formed, the receptacle (6) being annularly surrounded by a pressure chamber (7) which can be acted upon by a hydraulic medium and a wall closed in the form of the pressure chamber (7) between the receptacle (6) and the pressure chamber (7) a clamping portion (5 a) is formed such that they by a Pressure increase in the pressure chamber (7) is elastically deformable inwardly, and an intermediate sleeve (1 1) which in the receptacle (6) is inserted and a central clamping bore (13) defined, in particular according to claim 1, characterized in that in axially front end portion of the receptacle (6) between the receiving member (6) defining the component (5) and the intermediate sleeve (1 1) to the front end face of the Grundköpers (2) open annular gap (17) is present.

3. Hydraulic Dehnspanneinrichtung according to claim 1 or 2, characterized in that extending the axially front end portion of the receptacle (6) to the clamping portion (5 a).

4. Hydraulic Dehnspanneinrichtung (1) according to one of the preceding claims, characterized in that in the wall of the intermediate sleeve (1 1) a plurality in the longitudinal direction of the intermediate sleeve (1 1) extending slots (14) are formed.

5. Hydraulic clamping device, in particular for fixing a tool to a machine tool, with a clamping axis (X) defining base body (2), at the front end portion of a clamping area with a front end face of the base body (2) open central receptacle (6) a component to be clamped is formed, the receptacle (6) being annularly surrounded by a pressure chamber (7) which can be acted upon by a hydraulic medium and a wall closed in the form of the pressure chamber (7) between the receptacle (6) and the pressure chamber (7) a clamping portion (5a) is formed such that it is elastically deformable inwardly by an increase in pressure in the pressure chamber (7), and an intermediate sleeve (1 1) which is inserted into the receptacle (6) and a central clamping bore (13) defined, in particular according to one of the preceding claims, characterized in that the intermediate sleeve (1 1) is subdivided in its circumferential direction into intermediate sleeve segments (12), each of which carries on its front side, in particular on its front end face, a clamping finger (12a) extending in the axial direction, wherein the clamping fingers (12a) are each formed in such a way are and / or have such a cross-section that they are their two circumferentially considered ends on opposite sides, in particular on diametrically opposite sides of the clamping axis (X), wherein the circumferentially one, fixed end of the clamping fingers (12a) with the associated Zwischenbüchsensegment (12) is connected and the opposite free end comes into contact with a component to be clamped (W).

6. Hydraulic Dehnspanneinrichtung (1) according to claim 5, characterized in that on the radial inner side and / or the radial outer side of the free ends of the clamping fingers (12a) is formed in particular a part-circular clamping surface.

7. Hydraulic Dehnspanneinrichtung (1) according to claim 5 or 6, characterized in that the clamping fingers (12 a) at their axially front end surfaces each have a holding finger (12 b) and the holding fingers (12 b) are formed such that their outer surfaces and / or their inner surfaces lie on a common circle.

8. Hydraulic Dehnspanneinrichtung (1) according to one of claims 5 to 7, characterized in that the clamping fingers (12a) and / or holding fingers (12b) protrude axially from the base body (2).

9. Hydraulic Dehnspanneinrichtung (1) according to any one of claims 5 to 8, characterized in that the clamping fingers (12 a) are formed bent, with its associated with the intermediate sleeve segment (12) fixed end radially further out than its free end, and in that the clamping fingers (12a) are arranged such that the free end of a clamping finger (12a) is encompassed by the fixed end of a circumferentially adjacent clamping finger (12a).

10. Hydraulic Dehnspanneinrichtung (1) according to one of claims 5 to 9, characterized in that the cross section of the clamping fingers (12 a) tapers in the circumferential direction to the fixed ends and in particular is formed tapered.

11. Hydraulic Dehnspanneinrichtung (1) according to one of claims 5 to 10, characterized in that the intermediate sleeve (1 1) is divided in its circumferential direction in three intermediate sleeve segments (12), each carrying a clamping fingers (12a).

12. Hydraulic Dehnspanneinrichtung (1) according to claim 1 1, characterized in that the clamping fingers (12a) each extend over a circumferential range of 160 to 200 °, in particular of about 180 °.

13. Hydraulic Dehnspanneinrichtung according to one of the preceding claims, characterized in that the clamping portion (5a) formed integrally with the base body (2) and in particular the clamping region of the base body (2) with the clamping portion (5a) is made by a generative manufacturing process ,

14. Hydraulic Dehnspanneinrichtung according to one of claims 1 to 12, characterized in that the clamping portion (5a) forms an axial portion of a cylindrical expansion sleeve (5), which is used to form the pressure chamber (7) in the base body (2) and the central recording (6) defined.

15. intermediate bushing (1 1) in particular for use in a hydraulic Dehnspanneinrichtung (1) according to one of claims 1 to 14, which defines a central clamping bore (13), and in this wall several in the longitudinal direction of the intermediate sleeve (1 1) ersteckende slots (14), characterized in that the intermediate bushing (11) is subdivided in particular by the slots (14) in its circumferential direction into intermediate bushing segments (12), each having a clamping finger (12a) on its front side, in particular on its front end surface. carry, which extends in the axial direction, wherein the clamping fingers (12a) are each formed and / or have such a cross-section that their two circumferentially considered ends lie on opposite sides, in particular on diametrically opposite sides of the clamping axis (X) , wherein in the circumferential direction, a fixed end of the clamping fingers (12a) with the associated Zwischenbüchsensens Egment (12) is connected and the opposite free end comes into contact with a too-exciting component (W).

16. intermediate bushing (1 1) according to claim 15, characterized in that the clamping fingers (12 a) at their axial front end surface in each case a holding finger (12 b) wear and the retaining fingers (12 b) are formed such that their outer surfaces and / or their inner surfaces lie on a common circle.

17 intermediate bush (1 1) according to claim 15 or 16, characterized in that the clamping fingers (12 a) and / or holding fingers (12 b) protrude axially from the base body (2).

18. intermediate bushing (1 1) according to one of claims 15 to 17, characterized in that the clamping fingers (12 a) are formed bent, with her associated with the associated intermediate sleeve segment (12) fixed end is radially outward than its free end, and that the clamping fingers (12a) are arranged such that the free end of a clamping finger (12a) by the fixed end of a circumferentially adjacent clamping finger (12a) is encompassed.

19 intermediate bushing (1 1) according to claim 17, characterized in that the clamping fingers (12 a) at their axially front end surfaces each have a retaining finger (12 b) and the retaining fingers (12 b) are formed such that their outer surfaces and / or their inner surfaces lie on a common circle.

20. intermediate bushing (1 1) according to any one of claims 15 to 19, characterized in that the cross section of the clamping fingers (12 a) tapers in the circumferential direction to the fixed ends and is formed in particular tapered.

21 intermediate bush (1 1) according to one of claims 15 to 20, characterized in that it is divided in its circumferential direction in three intermediate sleeve segments (12), each carrying a clamping finger (12 a).

22 intermediate bushing (1 1) according to claim 21, characterized in that the clamping fingers (12 a) each extend over a peripheral region of 160 to 180 °, in particular of about 190 °.

An expansion sleeve (5) for use in a hydraulic expansion jig (1) according to any one of claims 1 to 14, comprising a central receptacle (6) defining an elastically deformable tensioning portion (5a) with a predetermined tensioning diameter, characterized in that the expansion bushing (5) at its axially front end Section (5b) has a flat undercut, in the region of the inner diameter of the expansion sleeve (5) is greater than the clamping diameter.

24. expansion bushing arrangement with an expansion bushing (5) which has a front end face open towards a central receptacle (6) which comprises an elastically deformable clamping portion (5a) and a clamping axis (X) defines, and an intermediate sleeve (1 1), which is inserted into the receptacle (6) of the expansion bushing (5) and defines a central clamping bore (13), characterized in that the expansion bushing (5) and the intermediate bushing (11) are integrally formed in the region of the tensioning section (5a) or materially bonded are connected to each other and that in the axially front end portion of the receptacle (6) such a connection between the expansion sleeve (5) and the intermediate sleeve (1 1) does not exist.

25 stretch sleeve assembly with a Dehnbüchse (5), which forms a front end face towards a central receptacle (6) defining a clamping axis (X), and an intermediate sleeve (1 1), in the receptacle (6) of the expansion sleeve (5) is inserted and defines a central clamping bore (13), in particular according to claim 24, characterized in that between the axially front end portion of the expansion sleeve (5) and the intermediate sleeve (1 1) one to the front end face of the Grundköpers (2) out open annular gap (17) is present.

26. Dehnbüchsenanordnung according to claim 24 or 25, characterized in that extending the axially front end portion of the receptacle (6) from the front end face to the clamping portion (5a) of the expansion sleeve (5).

27. Dehnbüchsenanordnung according to any one of claims 24 to 26, characterized in that in the wall of the intermediate sleeve (1 1) several in the longitudinal direction of the intermediate sleeve (1 1) extending

Slots (14) are formed.

28. Dehnbüchsenanordnung according to one of claims 24 to 27, characterized in that the intermediate sleeve (1 1) according to one of claims 14 to 21 is formed.