EP3218145A1

EP3218145A1 - Tool holder

Info

Publication number: EP3218145A1
Application number: EP15787173.2A
Authority: EP
Inventors: Juergen Fronius; Attilio Mandarello; Werner Schneider
Original assignee: Bilz Werkzeugfabrik GmbH and Co KG
Current assignee: Bilz Werkzeugfabrik GmbH and Co KG
Priority date: 2014-11-12
Filing date: 2015-10-23
Publication date: 2017-09-20
Also published as: US10376964B2; WO2016074901A1; JP2017537800A; DE202014105440U1; US20170239733A1; JP6722666B2

Abstract

The invention relates to a tool holder, comprising: a main part (12) for coupling to a drive spindle which can be rotatingly driven, on which main part a chuck (18) for clamping a tool is received; and a damping element (42) between the main part (12) and the chuck (18), said damping element (42) consisting of a material with a modulus of elasticity which differs from the modulus of elasticity of the material of the chuck (18) by at least 50%, and the chuck (18) being connected, preferably bonded, to the main part (12) only via the damping element (42).

Description

tool holder

The invention relates to a tool holder having a base body for coupling with a rotationally drivable drive spindle, on which a chuck is received for clamping a tool, with a damping element between the base body and the chuck, which consists of a material having a modulus of elasticity, the from the modulus of elasticity of the material constituting the chuck, deviates at least by an amount by 50%.

The invention further relates to an apparatus and a method for producing such a tool holder.

When rotating drive tool holders at high speed, such as with milling cutters or drills, vibrations often occur, which can adversely affect the work result and can negatively affect the life of the tools.

It has therefore often tried to construct tool holders with reduced tendency to oscillate.

From DE 10 2013 101 854 A1 discloses a tool holder is known in which a ring-shaped damping element is provided in a cavity between a base body of the tool holder and the associated chuck. The damping element has a small axial extent and is preferably made of a heavy metal and may be accommodated using an intermediate layer of plastic with an axial bias in the cavity. According to US Pat. No. 6,082,236 it is known to introduce tool elements for lathes in a targeted manner into a cylindrical part of the tool holder in order to dampen individual vibration modes, such as torsion about the longitudinal axis of the tool.

[0007] DE 20 2009 010 626 U1 discloses a tool receptacle with a damping ring provided with elastic elements, which is clamped between the machine-side spindle interface and the counterpart of the spindle so as to substantially damp bending oscillations.

Although the known solutions may cause a certain vibration damping in one way or another, but are not sufficiently effective for many applications.

Against this background, the present invention seeks to provide an improved tool holder, which has an improved vibration damping compared to the known from the prior art solutions.

Furthermore, a suitable device and a method for producing such a tool holder should be specified.

This object is achieved in a tool holder according to the type mentioned above in that the chuck is preferably connected via the damping element materially bonded to the base body.

The object of the invention is completely solved in this way. According to the invention, namely, the chuck and the main body are completely decoupled from each other by the damping element, since there is no connection between the chuck and the main body except the damping element.

This allows an effective damping of vibrations via the damping element. The modulus of elasticity of the material of the damping element differs significantly from the modulus of elasticity of the material of which the base body and / or the chuck consists, from. Preferably, the modulus of elasticity of the damping element has a non-linear course, whereby a particularly effective damping in the desired range can be achieved.

In the tool holder according to the invention, regardless of the load direction, the load is passed over the soft, elastic material relative to the feed base material and thus damped. This results in a reduction of the static stiffness of the tool holder.

The damping element consists of a further embodiment of the invention of an elastomeric material. This may be, for example, a damping element of a polyurethane material or of a rubber material.

With such elastomeric materials, a particularly effective damping while still sufficient rigidity of the tool holder can be achieved. In particular, polyurethane-based (PUR) or rubber-based elastomeric materials ensure a sufficiently rigid connection between the chuck and the tool holder and enable a material connection between the base body and the chuck with sufficiently high precision, so that concentricity errors are minimized.

According to a further embodiment of the invention, the damping element consists of a shape memory alloy.

Even with such an embodiment, a particularly effective vibration damping can be achieved.

According to a further embodiment of the invention, the damping element extends in an annular gap between a holding portion of the chuck and the main body. In this way, a continuous cohesive connection between the chuck and the main body is ensured by means of the damping element.

According to a further embodiment of the invention, the damping element forms a positive connection with the base body and the chuck. For this purpose, for example projections may be provided, in particular a polygonal basic shape of the Dämfungselementes.

In this way, an effective torque transmission is ensured by the positive connection.

[0024] According to a further embodiment of the invention, at least on the main body or on the chuck, a threaded section is provided, which permits a tensioning of the chuck relative to the main body, preferably by means of a clamping nut.

In this way, a bias between the base body and chuck can be achieved, for example, to ensure a certain damping characteristic.

For this purpose, the threaded portion cooperate with a clamping screw, wherein an elastomeric disc between the clamping screw and threaded portion is arranged, whose hardness is preferably selected.

In this way, the main body and the chuck are decoupled from each other in both directions. By selectively selecting the hardness of the elastomeric disk, a selectable bias voltage can be bi-directionally adjusted.

According to a further embodiment of the invention, the chuck is designed as a thermal shrink chuck. In such an embodiment of the chuck, the present invention is particularly advantageous because it ensures a high-precision tension of tools even with a small shaft diameter.

According to a further embodiment of the invention, in each case a centering collar are provided both on the base body and on the chuck, which is formed for centering the two parts to each other by an enclosing shape in a casting and vulcanization of the damping element.

In this way, a particularly good centering of chuck and body is guaranteed to each other.

The invention is further achieved by a device for producing a tool holder, comprising a base body for coupling with a rotationally drivable drive spindle, on which a chuck is received for clamping a tool, with a damping element between the base body and the chuck, the an elastomeric material having a shape in which a recess is provided in which the chuck and the base are centered relative to each other and secured against axial displacement receivable with at least one channel for supplying elastomeric material under pressure in a gap between the chuck and the base body, and with at least one venting channel in the mold.

With such a device can ensure a precise positioning between the base body and chuck when feeding the elastomeric material under pressure and during vulcanization, so that there is a tool holder with very low concentricity error. This results in a high-precision relative positioning between the base body and chuck.

In a preferred embodiment of this embodiment, a centering body is provided for positioning at the axial end of the chuck, which rests with its outer surface on an inner surface of the base body for centering and the Feed channels to allow a supply of the elastomeric material under pressure in the gap.

By means of the centering in this way, in addition to the centering of the chuck and the base body within the bore of the mold allows further centering in the interior, so that overall results in a further improved precision.

In a preferred development of this embodiment, the centering body has an extension with an external thread which can be screwed into an internal thread at the end of the chuck.

As a result, a direct engagement of the centering on the chuck is made possible for a clean centering, which can be easily solved after a vulcanization of the damping element.

According to a further embodiment of the invention, a pressure connection for supplying the elastomeric material via a pressure line through the base body is provided on the centering body.

By this measure, an immediate supply of the elastomeric material is ensured under pressure in the centering body and from there via the feed channels to the gap.

In a further embodiment of the invention, stops for axial fixation of the base body and chuck are provided on the mold.

In this way, a precise determination of the axial position of the body and chuck is ensured to each other when the elastomeric material is supplied under pressure into the gap. In a further advantageous embodiment of the invention, the mold has an inner surface, which is designed for centering of the base body and chuck by means provided thereon Zentrierbünde.

In this way, a very precise centering of the body and chuck to each other is possible.

The object of the invention is further achieved by a method for producing a tool holder, with a base body for coupling with a rotationally drivable drive spindle, on which a chuck is received for clamping a tool, with a continuous damping element made of an elastomeric material between the body and the chuck, the method comprising the steps of:

(A) providing a mold with a recess;

(B) inserting and centering of the base body and chuck in the recess, wherein a continuous gap between the base body and a holding portion of the chuck remains;

(C) axially locating the base body and chuck in the mold;

(D) supplying elastomeric material under pressure through the body to the gap between the body and the holding portion of the chuck until the gap is filled, with venting at the end of the gap to the outside via at least one venting channel in the mold ;

(E) vulcanizing the elastomeric material;

(F) removing the tool holder from the mold. By such a production, a clean connection between the base body and chuck with a precise centering of the two parts allows each other.

Preferably, in this case a centering collar on the base body and the chuck is used to center the main body and the chuck on the inner surface of the recess in the mold.

In this way, a high-precision centering of the body and chuck to each other from the outside is guaranteed.

In a further preferred embodiment of the method according to the invention, a centering body is used between the base body and the axial end of the chuck over which the holding portion is centered on an associated inner surface of the base body, wherein the elastomeric material is guided via feed channels in the centering in the gap ,

In this way, in addition to the centering of the chuck and the base body on the outside, a centering in the inner region between the base body and chuck is guaranteed, so that overall results in a further improved precision.

Here, the elastomeric Marterial preferably via a pressure line, which opens into the centering, and which can be screwed there about a thread supplied.

As the elastomeric material, a polyurethane or a rubber is preferably used.

Both materials allow a high stiffness, so that the tool holder can transmit sufficiently high torques without the damping element is too yielding. Likewise, these materials have a high temperature turbidity, which also allow use in a thermal shrink chuck, without the thermal shrinkage of the damping element is to be feared by the shrink clamping process.

The elastomeric material is preferably supplied at a pressure of at least 100 bar, preferably at least 500 bar and vulcanized at a temperature of 100 ° C to 280 ° C, preferably from 120 ° C to 200 ° C.

Most of the vulcanization is carried out in a range of about 150 ° C to 200 ° C, preferably about 180 ° C.

In operation, the damping element is sufficiently thermally stable, so that temperatures at the surface of the chuck of about 180 ° C are permanently tolerable, with a short-term increase in temperature up to about 200 ° C is possible without the tool holder takes damage.

It is understood that the features of the invention to be explained below and those to be explained below can be used not only in the respectively indicated combination but also in other combinations or in isolation, without departing from the scope of the invention.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. Show it:

Figure 1 is a perspective view of a tool holder according to the invention, but prior to the introduction of an existing elastomeric material damping element in an annular gap between the chuck and the base body.

2 shows a longitudinal section through the perspective view of FIG. 1. a partially sectioned side view of the tool holder of Figure 1, in which now additionally the damping element made of elastomeric material is shown in the annular gap between the base body and chuck, and a centering at the axial end of the chuck to ensure further centering in the interior. a section through the tool holder of Figure 3 along the line IV-IV ..; a device in longitudinal section, in the base body and chuck are used to ensure a precise centering of the two parts to each other during the manufacture of the damping element by an injection molding process; a section through the device of Figure 5 along the line VV. a partially sectioned partial view of a slightly modified version of the tool holder, which shows only the outer end with the chuck and a union nut; a slightly modified version of the tool holder in partial longitudinal section, wherein only the machine-side end is shown; a side view of the screw of FIG. 8 in a slightly enlarged view and a further modification of the embodiment of FIG. 2, wherein between the chuck and the base body a clamping screw is provided by an elastomer disc selectable hardness. In Figs. 1 and 2, a tool holder according to the invention is shown in perspective or perspective cut and designated overall by the numeral 10.

The tool holder 10 comprises a base body 12 in the known type HSK with a base body 12 for receiving on a machine spindle, on which a flange 14 is provided with an annular groove 15 for handling by a tool changer or the like.

Further, the tool holder 10 comprises a chuck 18 in the form of a thermal shrink chuck, which is shown in Fig. 1 and 2 with a gap 22 between the base body 12 and chuck 18, which is later filled by an elastic damping element. 1 and 2, the base body 12 and the chuck 18 are shown in their desired position to each other, with the representation of the damping element, which fills the gap 22 between the base body 12 and chuck 18, was omitted.

The chuck 18 has a holding portion 23 into which a tool, e.g. a milling tool, can be shrunk by first the chuck is widened by local heating in the region of the holding portion 23 and then the tool is introduced with its shaft, so that after cooling of the chuck 18, the tool is held in the holding portion 23 in a shrink fit. The chuck 18 extends with a holding portion 23 in an associated central bore of the base body 12, wherein an annular gap 22 between the holding portion 23 and the inner surface of the base body 12 remains outwardly between a centering collar 16 at the outer end of the base body 12 and an opposite centering collar 20 on the chuck 18 expires.

In known manner, the base body 12 has a central passage 24 with an inner cylindrical portion 26. At the facing axial end of the holding portion 23, an internal thread 28 is provided, into which an associated screw for minimum quantity lubrication can be screwed in order to cool from there. Lubricant over a subsequent coolant channel 30 to lead directly to the end of the holding portion 23 which is formed for tool holder. From there, the coolant lubricant reaches the work area via the tool shank.

Fig. 3 shows a longitudinal section through the tool holder 10 according to the invention after the generation of a damping element 42, which fills the gap 22 between the base body 12 and the chuck 30, by an injection molding process.

The damping element 42 fills the gap 22 between the main body 12 and the chuck 18 completely, thus ensuring a material connection between the base body 12 and chuck 18. The gap 22 is formed as a continuous annular gap, which extends from the machine-side axial end of the Holding portion 23 initially extends in a hollow cylindrical shape until shortly before the centering collar 20 and ends at the end radially outwardly between the two centering collars 16 and 20, so that there is an outer region 44 is formed.

Apart from a here in Fig. 3 additionally shown centering body 32 which is screwed into the internal thread 28 at the axial end of the holding portion 23, the base body 12 and the chuck 18 are connected to each other only via the damping element 42, which the annular gap 22 completely filled.

Although the damping element 42 may in principle also consist of a shape memory alloy, it preferably consists in the embodiment shown here of an elastomeric material, in particular of a polyurethane or a rubber material.

In contrast to the prior art, in which there is always a direct connection by welding or the like between the chuck and the base body at any point, according to the invention only a connection through the damping element 42 is provided. This is preferably a cohesive connection, which, however, additionally uses a positive connection, as can be seen from the cross section of FIG. 4.

In cross-section, the damping element 42 is thus not circular, but deviates from the circular shape, so that there is a positive connection. For example, projections 46 may be provided, so that the overall result is a polygonal basic shape with rounded edges. By a positive connection thus produced, the torque transmission between the base body 12 and chuck 30 is improved.

As already mentioned above, a centering body 32 is additionally shown in FIG. 3 on the machine-side axial end of the holding section 23.

This centering body 32 has an extension 34 which can be screwed with an external thread 36 into the internal thread 28 at the end of the holding section 23. The centering body 32 allows a precise centering between the holding portion 23 and the base body 12, since the centering body 32 engages with its cylindrical outer periphery in the inner cylindrical portion 26 of the base body 12. The inner cylindrical portion 26 is closely tolerated, e.g. ground so as to ensure a precise position of the centering body 32 and thus the end of the chuck 18, since the centering body is screwed with its extension 34 into the internal thread 28 at the axial end of the shrinking spindle 18.

The centering body 32 has at the machine end a central recess 40 with an internal thread 41 in order to screw a pressure line for supplying elastomeric material. An associated pressure line for the supply of elastomeric material which is screwed into the internal thread 41 is indicated by dashed lines at 43.

The central recess 40 is connected via a plurality of feed channels 38 with the axial end of the gap 22. The supply lines 38 are arranged distributed in a circle at the end of the central recess 40 and extend obliquely outwards toward the end of the gap 22. Preferably, the damping element 42 is made of an elastomeric material, such as a polyurethane or a rubber. Both materials can be conveyed in unvulcanized state under high pressure of several 100 bar, usually in the order of about 500 bar or more, into the gap 22 and then vulcanized.

Since the tool holder must have a high concentricity and as small centering errors between the base body 12 and the chuck 18 may occur, it is expedient to carry out the supply of the elastomeric material in the gap 22 in a device suitable for this purpose.

Such a device is shown in FIG.

For this purpose, a mold 50 is provided, which is formed as a solid tube and which has a central recess 52 which is designed for use of the base body 12 and the chuck 18. The inner surface of the central recess 52 is adapted in shape corresponding to the outer surface of the base body 12 and the chuck 18 and correspondingly tight tolerances, e.g. through a grinding process. The base body 12 is thus positioned with its flange 14 on the inner surface of the recess 52 and additionally precisely positioned by abutment of the centering collar 16 on the inner surface of the recess 52.

The chuck 18 is held centered by abutment of its centering collar 20 on the inner surface of the recess 52.

Further, axial stops are provided to fix the axial position of the base body 12 and the chuck 18 to each other when supplying the elastomeric material under pressure. For this purpose, a stop 54 is provided at the outer end of the chuck 18, which serves as a stop for abutment of the end face 56 of the chuck 18. At the opposite end of the mold 50, an axial stop 58 is provided, which serves for the axial abutment of the base body 12 with its flange 14. In the mold 50 further radial venting channels 62 are provided, which extend from the outer region 44 of the gap 12 to the outside.

Such a device makes it possible to supply elastomeric material via the pressure line 43 from the outside and to convey via the feed channels 38 directly into the end of the gap 22. From here, the material passes under high pressure into the outer region 44 of the gap 22 until it is completely filled and the material optionally exits into the venting channels 32. This process takes place at a pressure usually of about 500 bar or more and at elevated temperature of e.g. about 100 ° C.

For vulcanization, a short-term increase in temperature is generally carried out to more than 120 ° C, preferably to about 180 ° C.

The vulcanization takes only a relatively short time, which is less than ten minutes, usually 4 to 6 minutes are sufficient.

Subsequently, the thus completed tool holder 10 can be removed from the mold 50 and cooled. The centering body 32 is then unscrewed from the internal thread 28 and excess material that protrudes from the outer region 44 of the gap 22 via the adjacent centering collars 16, 20 is removed.

A tool holder 10 thus produced has a very high concentricity and has a highly effective vibration damping due to the damping element 42 which extends continuously over the entire annular gap 22 between the base body 12 and chuck 18.

Fig. 7 shows a modification of a tool holder, which is designated overall by 10a. In Fig. 7, only the outer end of the chuck 18 is shown together with a union nut 64 which engages over the centering collar 20 from the outside and which is screwed with an internal thread 68 in an associated external thread 66 on the outer surface of the base body 12. By the nut 64 thus an adjustable bias between the base body 12 and chuck 18 can be generated.

8 and 9, a further modification of the tool holder is shown and designated overall by the numeral 10b.

In Fig. 8, only the machine-side end of the tool holder 10b is shown. The only change compared to the previously described embodiment is that at the axial end of the damping element 42 in addition a paragraph 74 is provided in the base body 12, which allows a screw 70 which is screwed to the lubricant supply for minimal quantity lubrication in the internal thread 28, in addition with a formed on the screw 70 disc 76 abuts the shoulder 74.

Common in the prior art and provided according to the relevant DIN standard, a screw which is screwed into the internal thread 28 for the purpose of lubricant transfer to lubricant which is supplied on the machine side via the central passage 24 of the base body 12, directly into the Supply coolant channel 30.

Notwithstanding the DIN standard, a disc 76 is formed on the screw used here according to FIG. 9, which protrudes laterally and rests against the associated shoulder 74 of the base body 12.

Should be due to incorrect operation during thermal shrinkage clamping for clamping or unclamping of tools in the holding section 23 of the shrink chuck 18, a significant thermal overload occur, so that the maximum temperature of 180 ° C is exceeded not only in the short term, but for a longer time a higher Temperature of 200 ° C or more is reached, this can ultimately lead to disintegration of the damping element 42. In order to avoid in any case that in such a case, the chuck 18 can be detached from the base body 12, the screw 70 described above is used.

FIG. 10 shows a modification of the tool holder according to FIG. 2 and designated overall by 10c. Here, corresponding reference numerals are used for corresponding parts. As in the embodiment of FIG. 2, the tool holder 10c is shown with a gap 22 between the base body 12 and chuck 18, which is later filled by an elastic damping element.

Here, a threaded portion 78 is provided at the inner end of the holding portion 23 of the chuck 18, in which a clamping screw 80 is screwed, which is provided with a central coolant passage 30 for a minimum quantity lubrication. The clamping screw 80 rests with a collar 86 against an elastomeric ring 82, which is braced against a shoulder 88 at the end of the central passage 24 of the main body 12. The hardness of the elastomeric ring 82 may be selectively selected to provide a particular bidirectional bias. In addition, at the end of the receiving bore 30, an adjusting screw 84 is shown, which is adjustable in a threaded portion 86 of the chuck 18 to specify after vulcanizing the gap 22 with elastomeric material, the axial end position for a tool shank to be clamped precisely.

Claims

claims

Tool holder, comprising a base body (12) for coupling with a rotationally drivable drive spindle, on which a chuck (18) is received for clamping a tool, with a damping element (42) between the base body (12) and the chuck (18) the damping element (42) of a material having a modulus of elasticity, which differs from the modulus of elasticity of the material of which the chuck (18), at least by an amount of 50%, characterized in that the chuck (18) exclusively via the damping element (42) is preferably materially connected to the base body (12).

Tool holder according to claim 1, characterized in that the damping element (42) consists of an elastomeric material.

Tool holder according to claim 2, characterized in that the damping element (42) consists of a polyurethane material or of a rubber material.

Tool holder according to claim 1, characterized in that the damping element (42) consists of a shape memory alloy.

Tool holder according to one of the preceding claims, characterized in that the damping element (42) extends in an annular gap (22) between a holding portion (23) of the chuck (18) and the base body (12).

Tool holder according to claim 5, characterized in that the damping element (42) forms a positive connection with the base body (12) and the chuck (18), to which the damping element may be provided with projections (46), in particular may have a polygonal basic shape.

7. Tool holder according to one of the preceding claims, characterized in that at least on the base body (12) or on the chuck (18) has a threaded portion (66) is provided, which allows a clamping of the chuck (18) relative to the base body (12), preferably by means of a clamping nut (64).

8. tool holder according to claim 7, characterized in that the threaded portion (78) cooperates with a clamping screw (80), and that preferably an elastomeric disc (82) between the clamping screw (80) and threaded portion (78) is arranged, whose hardness is preferably selected ,

9. Tool holder according to one of the preceding claims, characterized in that the chuck (18) is designed as a thermal shrink chuck.

10. Tool holder according to one of the preceding claims, characterized in that both on the base body (12) and on the chuck (18) each have a centering collar (16, 20) is provided, for a centering of the two parts (12, 18) to each other is formed by an enclosing mold (50) during casting and vulcanization of the damping element (42).

1 1. Apparatus for producing a tool holder (10), having a base body (12) for coupling to a drive spindle which can be driven in rotation, on which a chuck (18) for clamping a tool is received, with a damping element (42) between the base body (12) and the chuck (18), wherein the damping element (42) consists of an elastomeric material, with a mold (50) in which a recess (52) is provided, in which the chuck (18) and the base body (12) centered one another and secured against axial displacement, having at least one feed channel (38) for supplying elastomeric material under pressure into a gap (22) between the chuck (18) and the base body (12), and having at least one vent channel (62). in the form (50).

12. The apparatus of claim 1 1, comprising a centering body (32) for positioning at the axial end of the chuck, which abuts with its outer surface on an inner surface of the base body for centering and the feed channels to a supply of the elastomeric material under pressure in the gap to enable.

13. The apparatus of claim 12, wherein the centering body (32) has an extension (34) with an external thread (36) in an internal thread (28) at the end of the chuck (18) can be screwed.

14. The apparatus of claim 12 or 13, wherein the centering body (32) has a

Compression connection (40) for supplying the elastomeric material via a pressure line (43) through the base body (19).

15. Device according to one of claims 1 1 to 14, wherein on the mold (50) stops (54, 58) for the axial fixation of the base body (12) and chuck (18) are provided.

16. Device according to one of claims 1 1 to 15, wherein the mold (50) a

Inner surface (52), which is designed for centering of the base body (12) and chuck (18) by means provided thereon Zentrierbunde (16, 20).

17. A method for producing a tool holder (10), comprising a base body (12) for coupling with a rotationally drivable drive spindle, on which a chuck (18) is received for clamping a tool, with a continuous damping element (42) made of an elastomeric material between the base body (12) and the chuck (18), with the following steps:

(a) providing a mold (50) having a recess (52); (B) inserting and centering of the base body (12) and chuck (18) in the recess (52), wherein a continuous gap (22) between the base body (12) and a holding portion (23) of the chuck (18) remains;

(c) Axially securing base (12) and chuck (18) in the mold (50);

(D) feeding elastomeric material under pressure through the base body (12) in the gap (22) between the base body (12) and the holding portion (23) of the chuck (18) until the gap (22) is filled, wherein a Ventilation at the end of the gap (22) to the outside via at least one venting channel (62) in the mold (50);

(e) vulcanizing the elastomeric material;

(f) removing the tool holder (10) from the mold (50).

18. The method according to claim 17, wherein in each case a centering collar (16, 20) on the base body (12) and on the chuck (18) is used to the main body (12) and the chuck (18) on the inner surface of the recess (52 ) in the mold (50).

19. The method of claim 17 or 18, wherein between the base body (12) and the axial end of the chuck (18) a centering body is used, via which the holding portion (23) on an associated inner surface (26) of the base body (12). is centered, wherein the elastomeric material via feed channels (38) in the centering body (32) in the gap (22) is guided.

20. The method of claim 19, wherein the elastomeric material via a pressure line (43) which opens into the centering body (32) is supplied.

21. Method according to one of claims 17 to 20, wherein a polyurethane or a rubber is used as the elastomeric material.

22. The method according to any one of claims 17 to 21, wherein the elastomeric material is supplied at a pressure of at least 100 bar, preferably of at least 500 bar and at a temperature of 100 ° C to 280 ° C, preferably from 120 ° C to 200 ° C is vulcanized.