EP3525969A1

EP3525969A1 - Hydraulic expansion chuck device

Info

Publication number: EP3525969A1
Application number: EP17793598.8A
Authority: EP
Inventors: Michael Haag
Original assignee: Schunk GmbH and Co KG
Current assignee: Schunk GmbH and Co KG
Priority date: 2016-10-17
Filing date: 2017-10-17
Publication date: 2019-08-21
Also published as: WO2018073265A1; DE102016119752A1

Abstract

The invention relates to an hydraulic expansion chuck device in the form of an expansion chuck, especially for securing a component or tool to a machine tool or a workbench. The device has a main part (2) which defines a clamping axis (X) and at the front end region of which a central recess (5) is provided, which is open towards the front end face (4) of the main part (2) and into which a component (B) to be clamped can be axially inserted. The recess (5) is surrounded by multiple pressure chambers (6) to which hydraulic pressure can be applied and which are evenly distributed across the circumference of the clamping portion and in particular are concentric to the clamping axis. In the regions between the clamping surface and the pressure chambers (6), the side (7) of the recess (5) in the main part (2) is elastic in such a way that when the hydraulic pressure in the pressure chambers (6) rises said side is elastically deformable towards the inside in order to frictionally secure a component inserted into the recess (5).

Description

DESCRIPTION

Hydraulic expansion device

The present invention relates to a hydraulic expansion chuck device, designed as a stretch chuck, in particular for fixing a component or tool to a machine tool or a work table, with a basic body defining a clamping axis, at the front end region of which a central receptacle is open towards the front end face of the main body. in which a component to be clamped is axially slidable, wherein the receptacle defines an axial clamping section and the wall of the receptacle in the region of the clamping section is hydraulically elastically deformable inwardly to fix a frictionally engaged in the receiving component gebobe- nes.

Furthermore, the present invention relates to a hydraulic Dehnspanneinrichtung, which is designed as Dehnspanndorn, in particular for fixing a component or tool on a machine tool or a work table, with a clamping axis defining base body on which a clamping portion is formed, on which a component to be pushed pushed is, wherein the wall of the clamping portion is hydraulically elastically deformed outwardly to fix a pushed onto the clamping portion component frictionally.

Finally, the present invention relates to an intermediate bushing usable with a chuck or a chuck according to the present invention for changing the active chucking diameter of the chuck. Such hydraulic expansion chucks - also known as hydraulic chucks - are known in the prior art in different configurations and serve to fix tools or components to be machined on a machine tool. There are two types of Dehnspanneinrichtungen, namely a so-called. Dehnspanndorne to clamp a component on the outside, and Dehnspannfutter having a central receptacle to clamp a tool shank, a shaft or the like on the inside. The known hydraulic expansion chucks usually comprise a base body defining a chuck or chuck axis, and an expansion sleeve which is inserted into the base body to form a pressure chamber surrounding the expansion sleeve and pressurizable with a hydraulic medium and a central one open to the front face of the base body Recording forms, in which a too exciting tool shank can be inserted. In this case, the wall between the pressure chamber and the receptacle is formed so thin and elastic that it is elastically deformable inwardly by an increase in pressure in the pressure chamber to fix a tool shank used in the recording frictionally.

In Dehnspanndornen the clamping section is provided on the outside of the base body and is formed by a usually cylindrical clamping surface. On the inside of the clamping surface, an annular pressure chamber is formed, wherein the wall between the clamping surface and the pressure chamber is formed elastically so that it is elastically deformable by an increase in pressure in the pressure chamber to the outside to fix a force applied to the clamping surface component. The known Dehnspanneinrichtungen have a defined clamping diameter, so that only components can be clamped, which have a corresponding to exciting diameter. Thus, the diameter of the receptacle in the case of a stretch chuck must correspond to the diameter of the shank to be clamped in such a way that the shank can be inserted into the receptacle and tensioned by the elastic deformation of the stretch bush when the pressure chamber is acted upon. In the same way, with a tensioning mandrel, the clamping diameter must correspond to the inside diameter of a component to be clamped.

If the corresponding diameters do not correspond to one another but, for example, tools with a small diameter are to be clamped with a chuck, intermediate sleeves are used to change the active clamping diameter of the expansion chuck.

Such intermediate sleeve has a barrel body cylindrical basic shape. In the case of using the intermediate sleeve with a Dehnspannfutter the sleeve body defines a central clamping bore whose diameter corresponds to the shaft diameter of the tool to be clamped. The outer diameter of the sleeve body is dimensioned to be insertable into the receptacle of the chuck and to deform the tightening portion of the sleeve body radially inward when the pressure chamber of the expansion chuck is pressurized.

In the case of use with a Dehnspanndorn the can body is formed in such a way that it can be pushed onto the clamping region of a hydraulic Dehnspanndorns and can be tensioned by this. In this case, a clamping surface on the outside of the elastically deformable Formed clamping portion of the sleeve body. The outer diameter of the Dehnspanndorns in the region of the clamping surface and the inner diameter of the intermediate sleeve are chosen so that the sleeve body comes with its clamping portion on the clamping surface of Dehnspann- mandrel in abutment, so that the clamping portion of the intermediate sleeve is deformed radially outward when the Pressure chamber of the expansion mandrel is pressurized.

To achieve the required elasticity, the sleeve bodies generally have a plurality of slots extending in the longitudinal direction of the sleeve body, which slots can extend in particular from the outer circumference of the inner circumference of the sleeve body.

The known expansion chucks or connection systems consisting of expansion chuck and intermediate bushing have proven themselves in practice. However, efforts are being made to make the deployment equipment more flexible.

Object of the present invention is to provide a hydraulic Dehnspannein- device of the type mentioned in such a way that it can be used flexibly.

This object is achieved in a trained as a chuck hydraulic Dehnspanneinrichtung of the type mentioned above in that the recording of several - especially exactly two, three or four - hydraulically acted upon pressure chambers is surrounded, evenly distributed along the circumference of the recording and in particular are formed concentrically to the clamping axis, and that radially located between the inner surface of the receptacle and the pressure chambers located wall regions are formed so elastically that they are by a Increasing the hydraulic pressure in the pressure chambers are elastically deformable inwardly to fix a component inserted into the receptacle frictionally. Furthermore, the object is achieved according to the invention in a hydraulic expansion chuck designed as a tensioning mandrel of the type mentioned above in that a plurality of - in particular exactly two, three or four - hydraulically loadable pressure chambers are formed in the expansion mandrel of the wall of the clamping portion, evenly distributed arranged along the circumference of the clamping portion and in particular are formed concentrically to the clamping axis, and that the radially located between the outer surface of the clamping portion and the pressure chambers wall portions is formed so elastically that they are elastically deformable by an increase in the hydraulic pressure in the pressure chambers inwardly to fix a pushed onto the clamping portion component frictionally.

The invention is therefore based on the consideration, Dehnspanneinrichtungen not see how to provide in the prior art with an annular pressure chamber over which the clamping portion is uniformly pressurized along its entire circumference with pressure, but rather several offset in the circumferential direction and spaced from each other Provide pressure chambers through which the wall of the clamping portion only locally in those peripheral regions over which the pressure chambers extend, is deformed. This creates the opportunity to load the component only locally, if desired. In this case, the individual pressure chambers are preferably connected to one another via connection channels, so that they can be pressurized together. For example, three pressure chambers may be provided with an angular offset of 120 ° in the circumferential direction. Preferably, the pressure chambers each extend over a circumferential region of 30 ° to 60 °, in particular of about 50 °.

Preferably, the base body with the pressure chambers is at least partially produced in a generative manufacturing process. Alternatively, it is possible in a conventional manner to carry out the basic body in several parts with an expansion sleeve in order to realize the pressure chambers.

According to one embodiment of the invention it is provided that the wall of the clamping portion over its entire axial length by recesses which extend in the longitudinal direction and in particular in the axial direction and which are preferably formed as radial longitudinal slots, forming circumferentially between the recesses Clamping areas over which a component is stretched, is segmented. Due to the segmentation, the wall of the clamping section can be deformed more easily than a closed wall.

In the lying between the recesses clamping areas clamping surface portions are then formed, which come into contact with the component to be clamped. These can be adapted to the shape of a component to be clamped. If, for example, a circular cross section is to be tensioned, the clamping surface sections are preferably also formed in the shape of a circle segment. Alternatively, the clamping regions may each carry a particular radial retaining projection, on which a clamping surface portion is formed, which comes into contact with the component to be clamped. In this embodiment, the contours of the clamping portion can otherwise be selected independently of the shape of the component to be clamped. With the hydraulic expansion chucks according to the invention, components can be actively clamped. In this case, the clamping portion comes locally in those peripheral regions over which the pressure chambers extend, with the component in contact when the pressure chambers are hydraulically acted upon.

By virtue of the fact that, according to the invention, a plurality of separate pressure chambers are provided, over which the tensioning portion is acted on locally only in those peripheral regions over which the pressure chambers extend, the possibility is also created to passively seal components after the tribos or tribos minis. Applicant's technology, which is generally known and described in EP 1 046 455 B1. The reason is that the local deformation of the wall of the clamping section by applying pressure to the pressure chambers leads to a radially inward / outward deformation in the region of the pressure chambers themselves. However, in the circumferential direction between the pressure chambers areas of the wall of the clamping portion is deformed in the reverse direction. In an embodiment as a chuck, pressurization of the pressure chambers thus causes the wall of the clamping section to be deformed outwardly in the area of the pressure chambers and outwards in the areas located therebetween. In the case of the design as Dehnspanndorn an application of the pressure chambers leads to an outward deformation of lying in the region of the pressure chambers Wandungsabschnitte, in the areas between the pressure chambers nen areas, however, to an inwardly directed deformation. Upon relief of the pressure chambers, the wall sections are elastically deformed in the opposite direction. With appropriate design of the clamping sections, this reverse deformation can be used to clamp a component passive. In this case, the actual clamping process does not take place locally in the area of the pressure chambers, as with the active voltage instead, but locally in the peripheral areas located between the pressure chambers. With a corresponding embodiment of the clamping section according to the Tribos or Tribos mini-technology of the application so a passive voltage with the Dehnspanneinrichtungen invention is possible lent.

Based on the tribos-mini-technology, for example, each pressure chamber may be associated with a recess which is positioned centrally of the pressure chamber in the circumferential direction, so that formed by the segmentation between the recesses or radial longitudinal slots clamping areas that are formed between the pressure chambers lie. If an active voltage is to take place, the recesses lie centrally between the pressure chambers in the circumferential direction. Likewise, each pressure chamber may be associated with a cavity which extends over the axial length of the clamping portion radially between the pressure chamber and the clamping surface in the circumferential direction and in particular is connected by the pressure chamber associated with the recess clamping surface. The cavities are positioned in the circumferential direction in each case centrally of the associated pressure chamber or in the circumferential direction in each case centrally between the cavities, preferably extend over a larger peripheral region than the pressure chambers. The cavities may be formed as peripheral slots and / or run concentrically to the clamping axis.

To increase the deformation elasticity, cavities can be formed in the base body, viewed in the circumferential direction, between the pressure chamber, which extend in the circumferential direction and, in particular, extend concentrically with respect to the clamping axis. In particular, the cavities can be formed as peripheral slots. In this case, the in Circumferentially circumferential ends of the circumferential slots connect end slots which surround the ends of the pressure chambers arcuate. In the case of a hydraulic expansion chuck designed as a stretch chuck, the cavities lie radially outside the cavities and the end slots extend outward from the circumferential slots. In the case of a hydraulic expansion chuck designed as a tensioning mandrel, the cavities lie radially inside the cavities and the end slots extend inwards. Alternatively, it is possible, for the realization of the Tribos- or Tri- bos mini-technology in the inclusion of a Dehnspannfutters use an intermediate sleeve having a central clamping bore for a component to be clamped, wherein the outer surface of the intermediate sleeve is formed such that the Intermediate bushing rests on the inside of the receptacle only in the circumferential regions corresponding to the pressure chambers, but is spaced from the wall of the receptacle in the intermediate circumferential regions, so that the intermediate bushing is elastically inward only in the contact regions when the pressure increases in the pressure chambers the intermediate circumferential regions is elastically deformed outwards, and is elastically deformed back to its original shape at a pressure relief of the pressure chambers. Accordingly, an intermediate sleeve can be pushed onto the clamping portion of a mandrel, on the outside of which a component is clamped, wherein the inner surface of the intermediate sleeve is formed such that it rests on the outside of the wall of the clamping portion only in the peripheral areas corresponding to the pressure chambers, in the intermediate Peripheral areas, however, is spaced from the wall, so that the intermediate sleeve elastically outwardly at an increase in pressure in the pressure chambers only in the contact areas, but in the lying between the investment areas peripheral areas is deformed inside, and is elastically deformed back to its original shape at a pressure relief of the pressure chambers.

In this case, with the Dehnspanneinrichtung invention continue to be actively clamped components and the clamping sections in a conventional manner be cylindrical or hollow cylindrical.

Alternatively, a passive voltage according to the Tribos technology can be realized by the use of an intermediate sleeve. The use of an intermediate sleeve also has the advantage that with a single expansion chuck over the use of intermediate sleeves with different clamping diameters different sized components can be stretched. Also in this case, viewed in the circumferential direction between the pressure chambers cavities may be formed in the body, which extend in the circumferential direction and in particular extend concentrically to the clamping axis. These can be designed as circumferential slots in the manner already described, with end slots then expediently adjoining the circumferential slots of the circumferential slots, which in particular enclose the ends of the pressure chambers in an arcuate manner.

The intermediate bushings can be segmented by corresponding axial recesses or longitudinal slots in the region of the inner or outer surface coming into contact with the component to be clamped. Likewise, in the body of the intermediate sleeve formed as a circumferential slots cavities may be formed, which are connected via the longitudinal slots with the exciting inner or outer surface of the intermediate sleeve, as is known from the Tribos mini-technology. In the end, they are in the subclaims 3 to 12 provided under protection embodiments of the inner contour of a chuck or the outer contour of a mandrel on the embodiment of an intermediate sleeve transferable. Specifically, the intermediate bushings may be formed according to the subclaims 14, 15 and 17 and 18, respectively.

If intermediate bushings are used which come into contact only locally on the wall of the tensioning section of an expansion chuck / expansion mandrel, expansion devices can also be used which have a pressure chamber extending annularly along the tension surface.

In the case of an action on the pressure chamber, the wall of the clamping section is then elastically deformed inwardly or outwardly over the entire handling, but the deformation also leads to a corresponding deformation of the intermediate sleeve only in the region of the contact surface.

Accordingly, according to a further aspect provided under protection, a hydraulic Dehnspanneinrichtung formed as Dehnspannfutter, in particular for fixing a component or tool on a machine tool or a work table, with a clamping axis defining base body, at its front end portion to the front end face of the body towards open central Receiving is formed, in which a component to be clamped axially slidably, wherein the receptacle defines an axial clamping portion with a clamping surface and the wall of the receptacle in the region of the clamping portion is elastically elastically deformable inwardly to fix a pushed into the receptacle member frictionally , wherein the receptacle is surrounded in a ring shape by a hydraulically actuable pressure chamber, which in particular is congruent. is formed centrally to the clamping axis, wherein the Dehnspanneinrichtung which is characterized in that in the receptacle an intermediate sleeve is used which has a central clamping bore for a component to be clamped, wherein the outer surface of the intermediate sleeve is formed such that the intermediate sleeve only in several - in particular exactly in two, three or four - defined, in the circumferential direction, in particular uniformly spaced contact areas on the wall of the receptacle inside abuts, but is spaced in the intermediate peripheral regions of the wall of the receptacle, so that the intermediate sleeve at an increase in pressure in the pressure chamber However, elastically outwardly deformed only in the contact areas in the intermediate peripheral regions and is elastically deformed back to its original position at a pressure relief of the pressure chamber. Furthermore, provided under protection is a hydraulic Dehnspannrichtung configured as Dehnspanndorn, in particular for fixing a component or tool on a machine tool or a work table, with a clamping axis defining base body on which a clamping portion is formed with a clamping surface on which a component to be clamped can be pushed, wherein the wall of the body in the region of the clamping portion is hydraulically elastically deformed outwardly to frictionally fix a pushed onto the clamping member, wherein in the main body on the inside of the clamping portion a hydraulically loadable pressure chamber is formed, the ringför- mig extends along the circumference of the clamping portion and is formed in particular concentric to the clamping axis, wherein the Dehnspanndorn is characterized in that on the clamping portion an intermediate sleeve is pushed, on the outside of a component spa fun nnbar, wherein the inner surface of the intermediate sleeve is formed such that it only in several - especially in exactly two, three or four - defined, spaced along the circumference and in particular evenly distributed positioned peripheral regions on the wall of the clamping portion on the outside but in the intermediate circumferential regions is spaced from the wall, so that the intermediate sleeve at an increase in pressure in the pressure chamber only in the contact areas elastically outward and thus in the lying between the abutment areas peripheral regions is elastically deformed inwardly and is elastically deformed at a pressure relief of the pressure chamber to its original position.

In this case, the intermediate bushes in the manner already described according to claims 24 and / or 25 or 27 and / or 28 are formed.

With regard to further advantageous embodiments of the invention, reference is made to the dependent claims and the following description of exemplary embodiments with reference to the drawing.

1 shows a side view of a hydraulic expansion chuck designed as a chuck according to a first embodiment of the present invention;

Figure 2 shows the hydraulic Dehnspanneinrichtung of Figure 1 in section along the line B-B;

Figure 3 is a side view of a hydraulic chuck formed as a chuck according to a second embodiment of the present invention; the hydraulic Dehnspanneinrichtung of Figure 3 in section along the line BB; the Dehnspanneinrichtung of Figure 3 in longitudinal section; the Dehnspanneinrichtung of Figure 3 in front view; a side view of a formed as a chuck hydraulic Dehnspanneinrichtung according to a third embodiment of the present invention; the expansion chuck of Figure 7 along the line BB in Figure 7; the hydraulic Dehnspanneinrichtung of Figure 7 in front view; the Dehnspanneinrichtung of Figure 7 in longitudinal section; a side view of a designed as a chuck hydraulic Dehnspanneinrichtung with an intermediate sleeve according to a fourth embodiment of the present invention; the hydraulic Dehnspanneinrichtung of Figure 1 1 in section along the line DD of Figure 1 1; a corresponding to the fourth embodiment variant of a trained as a chuck hydraulic Dehnspanneinrichtung; a side view of a formed as a mandrel hydraulic Dehnspanneinrichtung according to a fifth embodiment of the present invention; the hydraulic Dehnspanneinrichtung of Figure 14 in section along the line BB; the Dehnspanneinrichtung of Figure 14 in front view; the Dehnspanneinrichtung of Figure 14 in longitudinal section; a side view of a formed as a mandrel hydraulic Dehnspanneinrichtung according to a sixth embodiment of the present invention; the expansion chuck of Figure 18 along the line BB; a side view of the formed as a mandrel hydraulic Dehnspanneinrichtung according to a seventh embodiment of the present invention; the hydraulic Dehnspanneinrichtung of Figure 20 in section along the line BB; the hydraulic Dehnspanneinrichtung of Figure 20 in front view; the expansion chuck in section along the line AA in Figure 22; and FIG. 24 shows a variant of a hydraulic expansion chuck designed as a mandrel, corresponding to the seventh embodiment. Figures 1 and 2 show a hydraulic Dehnspanneinrichtung for clamping a component, in particular a tool shank, according to a first embodiment of the present invention. The hydraulic expansion chuck 1 is designed here as a chuck and comprises a base body 2, which defines a clamping or chuck axis X. At its left end region in FIG. 1, the base body 2 has a machine interface in the form of a clamping flange 2 a for attachment to a machine tool. As can be seen in Figure 2, in the clamping flange 2a a total of three evenly distributed along the circumference axial through holes 3 are formed, via which the Dehnspanneinrichtung 1 can be screwed to a work or machine table.

In the clamping flange 2a opposite the front end face 4 of the base body 2, a central receptacle 5 is formed, which defines a clamping portion with a clamping surface and into which a part to be clamped can be inserted.

The receptacle 5 is surrounded by a total of three pressure chambers 6, which extend over the axial length of the clamping portion. The pressure chambers 6 are formed with an angular offset of 120 ° in the base body 2 and each extend over a circumferential region of about 50 °. They can be acted upon with a hydraulic medium to elastically deform the wall 7 between the central receptacle 5 and the pressure chambers 6 inwards and thus fix a component inserted into the receptacle 5 in a force-fitting manner. For this purpose, located between the receptacle 5 and the pressure chamber 6 sections of the wall 7 are correspondingly thin and elastic. To pressurize the pressure chambers 6 are connected to each other via connecting channels 8 and are connected via a trained in Grundköper 2 hydraulic line 9 with a central source of hydraulic fluid in combination. The entire system with the pressure chambers 6, the connecting channels 8 and the hydraulic medium line 9 are filled in a conventional manner with a hydraulic fluid such as oil.

In the present case, the main body 2 is made with the pressure chambers 6 by a generative manufacturing process. Alternatively, it is possible, in a manner known per se, to construct the basic body in several parts, in particular with an expansion sleeve, in order to produce the closed pressure chambers 6, the connection channels 8 and the hydraulic medium line 9. FIGS. 3 and 4 show a second embodiment of a hydraulic tensioning device 1 according to the present invention designed as a chuck. This has the same basic structure as the first embodiment with a base body 2 which is fixable to a machine tool via a clamping flange 2a, and to the front end face 4 of the main body 2 open towards the central receptacle 5, in which a component to be clamped can be inserted. The receptacle 5 is surrounded by a total of three pressure chambers 6, which can be acted upon hydraulically in order to elastically deform the wall sections of the clamping section located between the receptacle 5 and the pressure chambers 6.

While in the first embodiment, a component to be clamped by applying pressure to the pressure chambers 6 is actively stretched, here a passively exciting system is provided, which spans accordingly when the pressure chambers 6 are pressure relieved. For this purpose, the wall of the Spannab- Sectionally segmented over its axial length by recesses 10 in the form of radial longitudinal slots. Specifically, each pressure chamber 6 is associated with a longitudinal slot 10 which is positioned centrally of the pressure chamber 6 in the circumferential direction. Between the three radial longitudinal slots 10 clamping regions 1 1 are defined, over which a component is tensioned. In the illustrated embodiment, the clamping areas each carry a radial retaining projection 12 on which a clamping surface portion is formed. Furthermore, each pressure chamber 6 is associated with a cavity 13 in the form of a concentric with the clamping axis X extending circumferential slot which extends over the axial length of the clamping portion between the pressure chamber 6 and the clamping surface in the circumferential direction. The circumferential slots 13 are positioned in the circumferential direction in each case centrally of the associated pressure chamber 6 and connected by the pressure chamber 6 associated longitudinal slot 10 with the clamping surface. As FIG. 4 clearly shows, the peripheral slots 13 extend over a larger circumferential area than the pressure chambers 6, here over an angular range of approximately 100 °.

In this embodiment, when the pressure chambers 6 are hydraulically loaded, the wall located between the pressure chambers 6 and the associated peripheral slots 13 is pushed inwardly. At the same time, the wall sections lying in the circumferential direction between the pressure chambers 6 are moved radially outwardly with the clamping regions 11, so that a component to be clamped can be inserted into the receptacle 5. If the pressure chambers 6 subsequently relieved again, return the clamping areas 1 1 by the elastic restoring force in its initial form and fix the inserted into the receptacle 5 component. In order to increase the elasticity, cavities 14 in the form of circumferential slots, which extend in the circumferential direction and extend concentrically to the clamping axis X, are formed in the circumferential direction between the pressure chambers 6. The circumferentially located ends of the circumferential slots 14 are adjoined by outwardly extending end slots 15 which extend arcuately around the ends of the pressure chambers 6.

FIGS. 7 to 10 show a third embodiment of a tensioning device according to the invention, which is designed as a chuck. This embodiment corresponds to the previously described second embodiment with the proviso that the expansion chuck is designed as an actively exciting expansion chuck 1. For this purpose, the three radial longitudinal slots 10 and the three provided between the receptacle 5 and the pressure chambers 6 circumferential slots 13 are rotated relative to the second embodiment by 60 °, so that the circumferential slots 13 as well as the cavities 14 substantially between the pressure chambers 6 extend while the clamping regions 1 1 radially lie directly within the pressure chambers 6, so that they are actively pressed inwards when the pressure chambers 6 are acted upon hydraulically.

FIGS. 11 and 12 show a fourth embodiment of a hydraulic tensioning device 1 according to the present invention designed as a chuck. This hydraulic expansion chuck 1 corresponds to the first embodiment, but here an intermediate sleeve 16 is inserted into the receptacle 5. Furthermore, cavities 14 in the form of circumferential slots with end slots 15 adjoining on the end side are provided between the pressure chambers 6, as in the third embodiment. The intermediate sleeve 16 is provided in order to be able to passively clamp components in a central clamping bore 17 of the intermediate sleeve 16 with the expansion clamping device 1. For this purpose, the outer surface of the intermediate sleeve 16 is designed and positioned so that it rests against the inner wall of the receptacle 5 only in the circumferential regions corresponding to the pressure chambers 6, ie in the circumferential direction of the central position of the pressure chambers 6 However, the intermediate sleeve 16 is spaced apart from the wall 7 at an increase in pressure in the pressure chambers 6 elastically outwards only in the contact areas and thus elastically deformed in the peripheral areas in between to form a component in the insert central clamping bore 17. As can be seen from FIG. 12, the intermediate sleeve 16 has for this purpose an outer cross-section of approximately triangular basic shape with rounded corner regions 18 which have a radius corresponding to the receptacle 5 and flattenings lying therebetween. With these rounded corner regions 18, the intermediate sleeve 16 abuts against the inner wall of the receptacle 5. It can also be seen in FIG. 12 that three radial retaining projections 19 are provided on the inner wall of the intermediate sleeve 16, which define clamping surface sections with which the intermediate sleeve 16 comes into abutment against a component to be clamped. It is also possible to segment the inner surface of the intermediate sleeve 16 by radial longitudinal slots.

In the case of using an intermediate sleeve 16, it is also possible, instead of several - in this case, three - discrete pressure chambers 6, to provide a single pressure chamber 6 extending annularly along the receiver 5. If this is subjected to a hydraulic pressure, although the wall 7 of the receptacle 5 is deformed inwardly along the entire circumference, however, the deformation only in the contact areas of the intermediate bushing 16 to a corresponding deformation thereof (see Figure 13).

In the figures 14 to 23 further three embodiments of hydraulic see Dehnspanneinrichtungen are shown according to the present invention, which are designed as Dehnspanndorn and have the same basic structure. Specifically, the hydraulic Dehnspanneinrichtungen 1 have a base body 2, which defines a clamping or chuck axis X. At its one end region, the main body 2 has a machine interface in the form of a clamping flange 2 for attachment to a machine tool. In the clamping flange 2a a total of three evenly distributed along the circumference arranged axial through holes 3 are formed, via which the Dehnspanneinrichtung 1 can be screwed to a work or machine table.

The front end region of the main body 2 is formed as a cylindrical mandrel 2b, which defines on the outside a clamping portion with a cylindrical clamping surface. On the clamping section, a component to be clamped can be pushed. In the mandrel 2b a total of three pressure chambers 6 are formed on the inside of the Spannab- cut, which are evenly distributed along the circumference of the clamping portion and spaced from each other. The wall of the main body 2 is formed elastically in the areas located between the clamping surface of the clamping section and the pressure chambers 6 in such a way that it is elastically deformed outward by an increase in the hydraulic pressure in the pressure chambers 6 in order to force fit a component pushed onto the clamping section to fix.

As can be seen in Figures 17 and 18, the clamping portion does not have to be cylindrical over the entire circumference. It is also sufficient if the clamping surface is only in the peripheral areas in which the pressure chambers 6 are formed, are formed according to the cylinder section.

The fifth and sixth embodiments of the expansion chuck device shown in FIGS. 13 to 18 operate as actively exciting systems with which a component is tensioned by pressurization of the pressure chambers 6.

Alternatively, the actively exciting systems can also be used for passive voltage in previously described manner by a corresponding intermediate sleeve 16 is pushed onto the mandrel-shaped clamping portion of the Dehnspanneinrichtung 1, as shown in Figures 19 to 22. For this purpose, the inner surface of the intermediate sleeve 16 is formed such that it rests only in the peripheral areas corresponding to the pressure chambers 6, ie approximately centrally in the direction of extension of the pressure chambers 6, on the outside of the wall of the clamping section, in the intermediate circumferential regions of the Wall is spaced, so that the intermediate sleeve 16 is elastically deformed at an increase in pressure in the pressure chambers 6 only in the contact areas elastically outward and thus in the lying between the abutment areas peripheral areas inwardly. In the illustrated embodiment, the intermediate sleeve 16 has an inner diameter that is larger than the outer diameter of the mandrel-shaped clamping portion of the Dehnspanneinrichtung 1. On the inner surface of the intermediate sleeve 16, however, three radially inwardly projecting retaining projections 20 are formed, with which the intermediate sleeve 16 comes to rest on the outer surface of the clamping portion of the Dehnspanneinrichtung 1. The outer surface of the intermediate sleeve 1 1 has a polygonal configuration with three protruding portions 21, which are positioned substantially between the pressure chambers 6, and located therebetween flats 22. The projecting portions 21st have a radius of curvature corresponding to the inner diameter of a component to be clamped.

For clamping a component, the pressure chambers 6 are subjected to pressure, so that the wall 7 of the clamping portion in the peripheral areas of the pressure chambers 6 are locally elastically deformed outwardly. As a result, the portions of the intermediate sleeve 16 in contact therewith are also deformed outwardly, and the wall portions located between the abutment portions, i. the projecting portions of the polygonal shape are simultaneously elastically deformed inwardly, so that a component can be pushed onto the intermediate sleeve 16. At a pressure relief of the pressure chambers 6, the wall 7 of the Dehnspanneinrichtung 1 and the intermediate sleeve 16 deform elastically back to its original shape, i. the protruding portions of the polygon shape are moved outwardly to tension the component.

Again, it is alternatively possible, instead of the three discrete pressure chambers 6, a single pressure chamber 6 'provide, which extends along the entire circumference of the clamping portion and is concentric with the clamping axis X, since an application of this pressure chamber 6' only in the investment areas to the Intermediate sleeve 16 also leads to a corresponding deformation thereof (see Figure 24).

The intermediate sleeve 16 can also be formed in one piece with the base body 2 or connected to it in a materially bonded manner. LIST OF REFERENCE NUMBERS

1 expansion chuck

2 main body

2a clamping flange

2b cylindrical mandrel

3 through hole

4 face

5 recording

6 pressure chambers

7 wall

8 connection channels

9 hydraulic fluid line

10 recess

1 1 clamping ranges

12 retaining projection

13 cavity

14 cavities

15 end slots

16 intermediate rifle

17 clamping hole

18 corner areas

19, 20 retaining projections

21 above range

22 flattenings

X clamping or chuck axis

Claims

1. Hydraulic Dehnspanneinrichtung, designed as Dehnspannfutter, in particular for fixing a component or tool on a machine tool or a work table, with a clamping axis (X) defining the base body (2), at its front end portion to the front end face (4) of the body ( 2) towards open central receptacle (5) is formed, in which a component to be clamped (B) is axially slidable, wherein the receptacle (5) defines an axial clamping portion and the wall (7) of the receptacle (5) in the region of the clamping portion is hydraulically elastically deformable inwardly to frictionally fix a pushed into the receptacle (5) component, characterized in that the receptacle (5) of several - especially exactly two, three or four - hydraulically acted upon pressure chambers (6) is surrounded , which are arranged distributed uniformly along the circumference of the receptacle (5) and in particular formed concentrically to the clamping axis, and in that the wall regions situated radially between the inner surface of the receptacle (5) and the pressure chambers (6) are designed to be elastically deformable inwardly by an increase of the hydraulic pressure in the pressure chambers (6), in order to form a receptacle (5) ) fixed component frictionally to fix.

2. Hydraulic Dehnspanneinrichtung formed as Dehnspanndorn, in particular for fixing a component or tool to a machine tool or a work table, with a clamping axis (X) defining base body (2) on which a clamping portion is formed, on which a component to be clamped axially is slidable, wherein the wall of the clamping portion is hydraulically elastically deformed outwardly to fix a pushed onto the clamping portion component frictionally, characterized in that in the Dehnspanndorn inside of the wall of the clamping section a plurality - in particular exactly two, three or four - hydraulically loadable pressure chambers (6) are formed evenly distributed along the circumference of the clamping portion arranged and in particular concentric to the clamping axis (X ) are formed, and that the radially located between the outer surface of the clamping portion and the pressure chambers (6) wall portions are formed so elastically that they by an increase in the hydraulic pressure in the pressure chambers (6) are elastically deformable inwardly to one on the clamping portion to secure the pushed component frictionally.

3. Hydraulic Dehnspanneinrichtung according to claim 1 or 2, characterized in that the wall of the clamping portion over its axial length by recesses (IO) which extend in the longitudinal direction and in particular in the axial direction and which are preferably formed as radial longitudinal slots, with the formation of in the circumferential direction between the recesses (10) lying clamping regions (1 1), over which a component is stretched, is segmented.

4. Hydraulic Dehnspanneinrichtung according to claim 3, characterized in that each pressure chamber (6) is associated with a recess (10), wherein the recesses are centrally positioned in the circumferential direction of the associated pressure chambers (6) or centrally between the pressure chambers.

5. Hydraulic Dehnspanneinrichtung according to claim 3 or 4, characterized in that the clamping regions (1 1) each carrying a particular radial retaining projection (12) on which a clamping surface portion is formed.

6. Hydraulic Dehnspanneinrichtung according to any one of the preceding claims, characterized in that each pressure chamber (6) is associated with a cavity (13) extending over the axial length of the clamping portion radially between the pressure chamber (6) and the inner surface of the Dehnspannfutterters recording ( 5) or the outer surface of the Dehnspann- mandrel extends along a peripheral region and in particular by the pressure chamber (6) associated with recess (10) is connected to the inner surface, wherein the cavities (13) in the circumferential direction in each case centrally of the associated pressure chamber (6) or in the circumferential direction are each positioned centrally between the cavities (13).

7. Hydraulic Dehnspanneinrichtung according to claim 6, characterized indicates that the cavities (13) extend over a larger peripheral area than the pressure chambers (6).

8. Hydraulic Dehnspanneinrichtung according to claim 6 or 7, characterized in that the cavities (13) are formed as circumferential slots and / or concentric to the clamping axis (X).

9. Hydraulic Dehnspanneinrichtung formed as a stretch chuck according to claim 1 and according to one of claims 6 to 8, characterized in that viewed in the circumferential direction between the pressure chambers (6) radially outside the cavities (13) cavities (14) in the base body (2) are formed, which extend in the circumferential direction and in particular run concentrically to the clamping axis (X).

10. Hydraulic Dehnspanneinrichtung according to claim 9, characterized in that the cavities (14) are formed as peripheral slots, wherein the ends lying in the circumferential direction of the circumferential slots connect outwardly extending, in particular the ends of the pressure chambers (6) arcuately surrounding end slots (15).

11. Hydraulic Dehnspanneinrichtung formed as Dehnspanndorn according to claim 2 and one of claims 6 to 8, characterized in that viewed in the circumferential direction between the pressure chambers (6) radially within the cavities (13) cavities (14) formed in the base body (2) are, which extend in the circumferential direction and in particular concentric to the clamping axis (X).

12. Hydraulic Dehnspanneinrichtung according to claim 1 1, characterized in that the cavities (14) are formed as circumferential slots, wherein extending circumferentially to the circumferential slots inwardly extending, in particular the ends of the pressure chambers (6) arcuately enclosing end slots (15 ) connect.

13. Hydraulic Dehnspanneinrichtung according to claim 1, characterized in that in the receptacle (5) an intermediate sleeve (16) is inserted, which has a central clamping bore (17) for a component to be clamped, wherein the outer surface of the intermediate sleeve (16) is formed is that the intermediate sleeve (16) only in the pressure chambers (6) corresponding peripheral regions on the wall (7) of the receptacle (5) inside abuts, but in the intermediate peripheral regions of the wall (7) of the receptacle (5) spaced is so that the intermediate bushing (16) is elastically deformed outwardly elastically inward only in the abutment areas when the pressure increases in the pressure chambers (6), but elastically outwardly in the intermediate circumferential areas, and elastically when the pressure chambers (6) are depressurized their original form is deformed back.

14. Hydraulic Dehnspanneinrichtung according to claim 13, characterized in that the intermediate sleeve (16) has an outer cross-section polygonal, in particular triangular basic shapes with rounded corner regions (18) and flattenings located therebetween, wherein the corner regions (18) to the receptacle (5) corresponding radius own and abut the inner wall of the receptacle (5).

15. Hydraulic Dehnspanneinrichtung according to any one of claims 13 or 14, characterized in that on the inner wall of the intermediate bush (16) a plurality, in particular three radial holding projections (19) are provided, which define clamping surface portions with which the intermediate sleeve (16) on a comes to exciting component in plant.

16. Hydraulic Dehnspanneinrichtung according to claim 2, character- ized in that on the clamping portion an intermediate sleeve (16) is pushed, on the outside of a component is clamped, wherein the inner surface of the intermediate sleeve (16) is formed such that it only in the However, in the intermediate circumferential regions of the wall of the clamping portion on the outside abuts the peripheral walls of the clamping chamber (6), so that the intermediate sleeve (16) at an increase in pressure in the pressure chambers (6) only in the contact areas elastically outward, but is elastically deformed inwardly in the peripheral regions lying between the abutment areas, and is elastically deformed back to its original shape at a pressure relief of the pressure chambers (6).

17. Hydraulic Dehnspanneinrichtung according to claim 13, characterized in that the intermediate bushing (16) has an outer cross-section of polygonal, in particular triangular basic shapes with rounded Eckenbe- rich (18) and located therebetween flats, with which the intermediate sleeve (16) comes into contact with a component to be clamped.

18. Hydraulic Dehnspanneinrichtung according to any one of claims 13 or 14, characterized in that on the inner wall of the intermediate sleeve (16) a plurality, in particular three radial retaining projections (19) are provided, with which the intermediate sleeve (16) on the outside of the wall of the clamping portion.

19. Hydraulic Dehnspanneinrichtung according to one of claims 13 to 18, characterized in that viewed in the circumferential direction between the pressure chambers (6) cavities (14) in the base body (2) are formed which extend in the circumferential direction and in particular concentric to the clamping axis ( X).

20. Hydraulic Dehnspanneinrichtung according to claim 19, characterized in that the cavities (14) are formed as circumferential slots, which adjoin the circumferentially extending ends of the circumferential slots end slots (15), which in particular the ends of the pressure chambers (6) arcuate enclose.

21. Hydraulic Dehnspanneinrichtung according to one of the preceding claims, characterized in that a total of three pressure chambers (6) are provided with an offset of 120 ° in the circumferential direction.

22. Hydraulic Dehnspanneinrichtung according to any one of the preceding claims, characterized in that the pressure chambers (6) each extend over a peripheral region of 30 ° to 60 °, in particular of 50 °.

23. Hydraulic Dehnspanneinrichtung, designed as Dehnspannfutter, in particular for fixing a component or tool on a machine tool or a work table, with a clamping axis (X) defining the base body (2), at the front end portion of a front end face (4) of the Base body (2) towards open central receptacle (5) is formed, in which a component to be clamped (B) is axially slidable, wherein the receptacle (5) defines an axial clamping portion and the wall (7) of the receptacle (5) in the area the clamping section is elastically elastically deformable inwards in order to frictionally fix a component pushed into the receptacle (5), the receptacle (5) being annularly surrounded by a hydraulically loadable pressure chamber (6 ') which is in particular concentric with the clamping axis (X) is formed, characterized in that in the receptacle (5) has an intermediate sleeve (16) is inserted, which has a central clamping bore (17) for egg n to exciting component, wherein the outer surface of the intermediate sleeve (16) is formed such that the intermediate sleeve (16) only in several - especially in exactly two, three or four - defined, circumferentially, in particular evenly spaced investment areas on the wall ( 7) of the receptacle (5) rests on the inside, but in the intermediate circumferential regions of the wall (7) of the receptacle (5) is spaced, so that the intermediate sleeve (16) at a pressure increase in the pressure chamber (6 ') only is deformed elastically outwards in the contact areas elastically inwards, but in the intermediate circumferential areas, and is elastically deformed back to its starting position when the pressure chamber (6 ') is depressurized.

24. Hydraulic Dehnspanneinrichtung according to claim 23, characterized in that the intermediate sleeve (16) has an outer cross-section polygonal, in particular triangular basic shapes with rounded Eckenbe- areas (18) and located therebetween flats (22), wherein the Corner regions (18) have a radius corresponding to the receptacle (5) and abut against the inner wall of the receptacle (5).

25. Hydraulic Dehnspanneinrichtung according to any one of claims 23 or 24, characterized in that on the inner wall of the intermediate sleeve (16) a plurality, in particular three radial holding projections (19) are provided, which define clamping surface sections with which the intermediate sleeve (16) at one exciting component comes into plant.

26. Hydraulic Dehnspanneinrichtung formed as Dehnspanndorn, in particular for fixing a component or tool to a machine tool or a work table, with a clamping axis (X) defining the base body (2) on which a clamping portion is formed, on which a to exciting component pushed is, wherein the wall of the clamping portion is elastically elastically elastically deformed outwardly to frictionally fix a pushed onto the clamping portion component, and wherein on the inside of the wall of the clamping portion a hydraulically loadable pressure chamber (6 ') is formed, which is annular along the circumference extends the clamping portion and in particular concentric to the clamping axis (X) is formed, characterized in that on the clamping portion an intermediate sleeve (16) is pushed, on the outside of a component is clamped, wherein the inner surface of the intermediate sleeve (16) is formed such that she only in meh Reren - in particular in exactly two, three or four - defined, spaced along the circumference and in particular evenly distributed peripheral regions on the outside of the wall of the clamping portion, however, in the intermediate circumferential regions of the wall (7) is spaced, so that the intermediate sleeve (16) at an increase in pressure in the pressure chamber (6 ') elastically outwards only in the contact areas, but elastically in the peripheral areas lying between the contact areas is deformed inside and at a pressure relief of the pressure chamber (6 ') is elastically deformed back to its original position.

27. Hydraulic Dehnspanneinrichtung, according to claim 26, character- ized in that the intermediate sleeve (16) has an outer cross-section polygonal, in particular triangular basic shapes with rounded corners (18) and flats lying between them, with which the intermediate sleeve (16) to be clamped Component comes into plant.

28. Hydraulic Dehnspanneinrichtung, according to any one of claims 26 or 27, characterized in that on the inner wall of the intermediate sleeve (16) a plurality, in particular three radial holding projections (19) are provided, with which the intermediate sleeve (16) on the wall of the clamping portion on the outside is applied.

29. Hydraulic Dehnspanneinrichtung according to one of the preceding claims, characterized in that the base body (2) with the pressure chambers (6) is at least partially made in a generative manufacturing process.