DE10108239A1 - Expanding tool for expanding pipe ends and pressing device with an expanding tool - Google Patents

Abstract

The invention relates to an expansion tool (1) for expanding tube ends (7). Said expansion tool has an expansion mandrel (8) and a counter-support (9), said expansion mandrel (8) consisting of a tow-bar (10) and an elastic rubber expansion element (11) surrounding it. The counter-support (9) supports the expansion element on the base extremity and radially surrounds it at a distance. In order to improve an expansion tool of the above-described kind, the tow-bar (10) is anchored in a bolt fastening element (20) and the counter-support (9) can be impinged upon via a pressure bar element (25) that projects beyond the bolt fastening element (20) in the longitudinal direction of the tow-bar (10).

Description

The invention first relates to an expanding tool for Expanding pipe ends, using the expanding tool has an expanding mandrel and a counterholder, wherein further the expanding mandrel from a pull rod and one this surrounding, elastic rubber expansion element there is and the counter-holder the expansion element Fußsei supported and radially surrounds at a distance.

Such expanding tools for expanding pipe ends are known. The pipe end to be widened here in an annular space between the expansion element and inserted the counterhold, after which by movement the pull rod in the direction of the expansion element the counter-holding base on the foot side, the expansion ment is compressed, which is a widening of the pipe end has the consequence.

With regard to the prior art described above nik becomes a technical problem of the invention seen in it an expanding tool in question to further develop the type in an advantageous manner.

This problem is first and foremost with Subject of claim 1 solved, being abge is that the tie rod is in a bolt fastener is anchored and that the counter-holder can be acted upon via a push rod element, which in Longitudinal direction of the pull rod up to the bolt fastening protruding element. As a result of this beneficial The expansion tool according to the invention is designed Can be used in the simplest way on conventional hydraulic Devices, in particular pressing devices, which roll  on the expanding tool, especially on the printing press gene element, act. The expansion according to the invention tool is designed so that by pressurization supply to the push rod elements, e.g. via the roller len a pressing device, the counter-holder relative to the tie rod anchored in the bolt fastener is shifting what is the widening of the tie rod surrounding and on the foot side against the counterholder supporting rubber expansion element. The up Wide tool is over the bolt fastener with the device acting on the push rod element rigid, but preferably connected interchangeably. here it is intended that the bolt fastener a transverse to the axial direction of the drawbar Has bolt receiving bore. That's how it's fictional appropriate expanding tool in the simplest way via a Bolt connection with which the push rod element is actuated striking, as well as the bolt fastener hal pressing device by means of a bolt or the like connectable. It is further suggested that that Push rod element is fastened in the counter holder. For example, a screw connection can be provided here his. However, a welded connection is also conceivable. It is also proposed that the push rod element penetrates the bolt fastener. Therefore the pressure rod element is pressurized tes upstream in the direction of actuation thereof Fastening area of the expanding tool, the Push rod element freely in its longitudinal axis direction in the fastener is slidable. Prefers becomes an embodiment in which the push rods element is designed like a plunger. So that's it Do not attach the push rod element with the counter holder increases, but only works closely with it together, with pressurization of the pressurizer  Genelementes on the press device to be arranged on the Counterholder is transferred. The provision of the Expanding tool takes place automatically via the back positioning properties of the elastic expansion element, which is at one end on the anchored tie rod supporting the counterholder and only the Leave the plunger in the starting position siege. As particularly advantageous, especially with regard to Uniform power transmission proves itself an embodiment in which more than two printing presses gene elements or plunger are provided. So is special preferred an embodiment in which four in a cross section through the push rod elements in push rod elements arranged in a rectangle or Push through the bolt fastener and act on the counterhold. With an expansion unit witness of the kind in question, in which the opposite holder is cup-shaped, is further provided hen that in the bottom of the pot a step out which is a foot area of the expanding element takes up. As a result of this configuration Critical bulges at the base of the expansion element avoided in the course of the expansion process. Also serves to expand the step on the top as a stop for one of the tube, which is related to the inside out formed stage has the advantageous effect that one to the end of the pipe to be expanded uniform expansion is achieved. For difference Pipes of different sizes can be used for different expansion tools ge be provided, which in the respective bolt befe Verification element with the press or the like is binding. Alternatively, it is suggested that in the bolt fastener for fastening the A screw-in adapter part is provided, to adapt to different tie rod diameters  ser. This configuration is particularly evident in Connection with the arrangement of only that Plunger plunger as advantageous. So can fasten the same bolt in the simplest way different pull rods and counterholders be assigned. In a further training of the Erfin subject matter is provided that in Beaufschla direction in front of the counter holder a pressure plate is arranged, on which the push rod elements act and that between the pressure plate and the Bracket arranged a force limiting device is not. The strength limit is preferably present tion device made of a plastic part, the Plastic part has a higher rigidity than the expansion element. This expansion element can also be a be flexible plastic, which is very hard from, for example, 90 to 100 Shore, preferably about 95 Shore having. This is preferably a Polyurethane plastic, over what pressures up to about 200 bar can be generated. To in the area of the Free end of the expanding flange facing away from the counter holder base Counteracting critical formations is in a further development of the subject matter of the invention hen that downstream in the direction of exposure the expanding element, but also caught through the tie rod an expansion transition element is arranged. The latter preferably consists of one stop-compression-limited plastic part. As a result of this configuration, possible Ausfor in the end area of the expansion element, which are can set at high pressures by yourself resulting bead of the expansion transition element be borders. In this regard, it is further provided that the Stroke compression by a counter, the expansion ment-limiting stop disc, movable stop sleeve  exists, with the stop sleeve one, by a tie rod head loaded sleeve bottom points in a tube surrounding the drawbar cut passes. According to this, the widening-over aisle element gripped between two sleeve elements, which sleeve elements for a given compression have moved together and so another compri Do not allow expansion of the expansion transition element. To ensure an exact widening of the pipe end is in a further development of the invention counter provided that within the counterhold Matrix element is added. The latter forms in In the course of the expansion process, a negative form into which the pipe end is inserted by means of the rubber expansion element is pressed. This also prevents that Elastomer element in the course of the expansion over the waistband at the end of the drawbar into a gap between Inflates the collar and tube end and thereby an uncon trolled further expansion of the pipe end causes becomes. The die element can be in the form of manually screwing half shells, which the end of the support to be expanded pipe, be shaped. before on the other hand, a configuration is added in which the die element divided in the longitudinal direction from several other sub-matrices, so on, for example four, each with a 90 ° circular segment bil ending quarter shells. That recorded in the counterholder mene matrix element or the recorded submatri zen are relative to the counter holder in the axial direction displaced. In this regard, it is proposed that the die element the elastic rubber expansion element engages, preferably further provided that the die element with radially aligned Collar in the area of the tie rod between the rubber Expanding element and one in the area of a counter neck  terboden supporting compression spring is caught. As It proves particularly advantageous that a partial matrix ze in the course of pressing from a removal position for the pipe end to be widened by axial displacement in a pressing position while reducing the radia len distance to the drawbar is displaceable. according to In this embodiment, the sub-matrices of the Matri zenelementes radially in the course of the expansion process Shifted towards the pipe end to be expanded, after which partial axial sections of the partial matrices backward supported by the counter holder on the outer wall of the pipe to be expanded. As a result no ring gap can arise between the tie rod and the pipe hen in which the elastomeric material of the expansion element tes can flow in uncontrolled. The expansion of the The end of the pipe is in its geometry, especially in its Axial extension clearly defined. With regard to the Radial displacement of the sub-matrices in the course of the expansion process is in an advantageous development of the Subject of the invention provided that on the counter a guide slope is formed on the inside, with a guide projection of the die element interacts. For an axially parallel publishing house tion of the matrix element or its submatrices secure, it can be further provided that in axial direction two distant guide slopes in different radial distance to the tie rod are arranged.

The invention further relates to a pressing device an expanding tool for expanding pipe ends, wherein the expanding tool is an expanding mandrel that consists of a pull rod and a surrounding elastic There is a rubber expansion element, a counter holder, which supports the expansion element on the foot side and radially  surrounds at a distance. To a press device of the Advantage of the type in question it is suggested that the tie rod with the Press device is firmly connected while the counter holder is acted upon by a push rod element. last res is used to actuate the press relative to Drawbar shifted. Furthermore, it is provided that induce the tie rod in a bolt fastener kert is what the latter of the attachment of the expansion tool on the press device. As a result the tie rod rigid with the fastener connected to the pressing device. It is also provided that the push rod element in the longitudinal direction of the pull rod protrudes beyond the bolt fastener. In A preferred embodiment provides that the bolt fastener is transverse to the axis direction of the drawbar bolt hole has, for bolt connection of the expanding tool with the pressing device, it being further preferred that the push rod element the bolt fastener interspersed. As a result of this configuration, the pressure rod element in the longitudinal direction of the tie rod freely in the bolt fastener displaceable. Further advantageous, especially with regard to an improvement th power transmission, it turns out if more than two push rod elements are provided. So be preferably arranged four push rod elements, which the bolt fastener outside of the bolt-on Push through the bore and more preferably in one Cross section through the push rod elements of a right corner shape are arranged. The push rod angel ment can continue to be connected to the counter holder be that, for example screw or welded. An embodiment is preferred in which the Push rod element as a mere, with  the plunger not connected plunger is. Finally, it is proposed that the Pressge advises to act on the plunger via rollers.

The invention is based on the attached Drawing, which is only three embodiments represents, explained in more detail. It shows:

Fig. 1 is a view showing a press device having disposed, according to the invention expansion tool in a basic position;

Fig. 2 is a detail view of the expansion tool in a top view;

Fig. 3 is a side view of the expansion tool;

Figure 4 shows the section along the line IV-IV in Figure 2, the basic position of the expanding tool concerning fend.

FIG. 5 shows a sectional illustration according to FIG. 4, but relating to the working position;

. Fig. 6 is a representation corresponding to Figure 2, but showing a second embodiment of the expander tool on;

Fig. 7 is a side view thereof;

. Fig. 8 shows the section line VIII-VIII in Fig 6, the basic position Pursuant;

FIG. 9 is a sectional representation corresponding to FIG. 8, but relating to the working position;

FIG. 10 shows an enlargement of area XX in FIG. 9;

FIG. 11 is an exploded perspective view of the expansion tool of the second embodiment;

12 shows the expansion tool in perspective can be arranged to a hydraulic pressing apparatus.

Fig. 13 is a further perspective view, advises after arranging the expanding tool to a Pressge;

Figure 14 is a partially sectioned, perspective view of an expansion tool in a third embodiment, an unloaded initial position on.

FIG. 15 is a longitudinal section through the expansion tool according to Fig. 14;

FIG. 16 is an exploded perspective view of the expansion tool;

FIG. 17 shows a representation corresponding to FIG. 14, relating to the pressing position;

. FIG. 18 is the longitudinal section according to Figure 15, but the position shown in Figure 17 on.

FIG. 19 shows another representation corresponding to FIG. 14 after expanding a pipe end; FIG.

Fig. 20 is a longitudinal section to Fig. 19.

First shown and described with reference to FIG. 1 is an expanding tool 1 for connection to a hydraulic pressing device 2 . The latter has a Bol zen fixed part 3 for fixing the expanding tool 1 and also has a hydraulically via a piston 4 relative to the bolt fixed part 3 displaceable movement part 5 , which is approximately U-shaped in a cross section in the illustrated embodiment is and two juxtaposed Nete traversing rollers 6 rotatably mounted.

The expanding tool 1 serves to expand pipe ends 7 , for which purpose the expanding tool 1 has an expanding mandrel 8 and a counter-holder 9 .

In a first embodiment according to the illustrations in FIGS . 1 to 5, the expanding mandrel 8 consists essentially of a pull rod 10 and surrounds the elastic expanding element 11 , the latter preferably being a polyurethane plastic. The Zugstan ge 11 has at one end, the expanding element 11 supporting tie rod head 12 , the diameter of which corresponds to that of the expanding element 11 in the unloaded position according to FIG. 4.

The counter-holder 9 surrounding the expanding mandrel 8 is pot-shaped, with a rod-shaped head end pointing in the direction of the train, which is free in cross-section ring-shaped receiving opening 13 , which is delimited radially on the inside by the expanding element 11 and radially on the outside by the counter-holder wall 14 . The counter holder 9 is movable relative to the pull rod 11 in the longitudinal extension thereof.

The pot base 15 facing away from the tie rod head 12 of the counter-holder 9 forms on the inside a step 16 which receives a foot region 17 of the expansion element 11 , the diameter of the step 16 being adapted to the diameter of the expansion element.

The pot base 15 delimited by the counter-holder wall 14 serves as a stop for the pipe end 7 to be expanded . The edge in the transition area between Topfbo 15 and level 16 is provided with a phase 18 .

The pull rod 10 passes through the counterholder 9 in the area of a correspondingly adapted bore 19 of the pot base 15 and is anchored at the end, opposite the pull rod head 12 , in a bolt fastening element 20 . The latter is cuboid in the exemplary embodiment shown and has a threaded bore 21 for anchoring the tie rod 10 , into which an end threaded portion 22 of the tie rod 10 engages.

This bolt fastening element 20 serves to hold the expansion tool 1 on the pressing device 2 , for which purpose the bolt fastening element has a bolt receiving bore 23 extending transversely to the axial direction of the pull rod 10 . Through the latter, the fixed bolt part 3 of the pressing device 2 .

Furthermore, the bolt fastening element 20 has on both sides of the bolt receiving bore 23 two superposed guide bores 24 aligned in the axial direction of the pull rod 10 , for the passage of push rod elements 25 in the form of plungers 26 . The latter protrude on both sides of the bolt-fastening element 20 beyond this, the ends 28 , each provided with a retaining ring 27 in the region of the pot base 15 on the counter-holder 9, act on the latter. These ends 28 abge facing ends 29 are provided with radial thickenings 30 against which the traversing rollers 6 of the Pressge device 2 are present for pressurization.

To widen a tube end 7 inserted into the receiving opening 13 , the pressing device 2 is actuated, which causes the displacement rollers 6 to be displaced forward via the piston 4 . The latter in this case act on the plunger 26 , which results in the counter-holder 9 being displaced relative to the pull rod 10 in the direction of movement r. In the course of this shifting of the counter holder, the expansion element 11 , which is gripped between the pot base 15 or the step 16 and the anchored tie rod head 12 , is compressed, which results in a radial expansion of the same and a radial expansion of the pipe end 7 according to FIG. 5 has the consequence. This radial expansion is limited by the counter-holder wall 14 .

After exceeding a predetermined force, the piston 4 of the pressing device 2 automatically returns to its initial position shown in FIG. 1, whereby the backward support of the plunger 26 is canceled. The expanding tool 1 , due to the elastic properties of the expanding element 11 , automatically returns to the starting position, after which the expanded pipe end 7 can be removed from the receiving opening 13 of the retainer 9 .

FIGS. 6 to 10 show a second Ausführungsbei play an expansion tool 1 which can be acted upon as the previously described embodiment by a pressing apparatus 2. Here, the bolt-fastening element 20 is of the same design as the first embodiment, with a screw-in adapter part 31 being screwed into the threaded bore 21 for the arrangement of a pull rod 10 for pipe ends 7 of smaller diameter. This allows tie rods 10 with different diameters to be fastened to one and the same bolt fastening element 20 . For this purpose, it is only necessary to screw the appropriate screw-in adapter part 31 into the threaded bore 21 .

This screw-in adapter part 31 in turn has a threaded bore 32 for receiving the end threaded portion 22 of the tie rod 10 , the latter being secured by a lock nut 33 .

The counter-holder 9 of this second embodiment has a pressure plate 34 arranged in front of it in the direction of action r. Between this and the counter holder 9 , a force limiting device 35 consisting of a plastic part is arranged. This plastic part has a higher rigidity than the expansion element 11 .

The stud fastener 20 passing through the push rod member 25 and plunger 26 apply in this embodiment, the printing plate 34 on the side facing away from the counter-holder 9.

Furthermore, in this second exemplary embodiment, an expansion transition element 36 is arranged downstream of the expansion element 11 in the direction of action r, but nevertheless trapped by the pull rod 10 . The latter consists of a stop-compression-limited plastic part 37 , which is held between a stop disc 38 and a stop sleeve 39 , the pipe section 40 surrounding the pull rod 10 carrying the cross-sectionally plastic part 37 .

The stop disk 38 limits the expansion element 11 in the end region facing away from the pot bottom 15 of the counter-holder 9 and can be displaced relative to the pull rod 10 .

The stop sleeve 39 is supported against the tie rod head 12 .

The measured in the longitudinal extent of the tie rod 10 width of the plastic part 37 is chosen larger than the length of the pipe section 40 measured in the same direction, so that between the free Rohrab cutting end and the stop plate 38 a between the plastic part 37 and the tie rod 10 he stretching free annular space remains.

In order to expand a pipe end 7 inserted into the expanding mandrel 8 , the push rod elements 25 or plunger 26 are also subjected to rolling 6 in the direction of movement r in this exemplary embodiment, which results in a displacement of the counter-holder 9 together with the pressure plate 34 and the force limiting device 35 in motion direction r against the anchored tie rod 10 results. The force introduced is limited here by the plastic part between the counter-holder 9 and the pressure plate 34 .

In the course of this shift, the expansion element 11 is also compressed here, with the same radial expansion. As a result, the pipe end 7 is limited limited widened against the counter-holder wall 14 .

In addition, the introduced via the plunger 26 force causes axial displacement of, the expander member 11 endsei tig confining pressure stop disc 38 in the direction of the stop sleeve 39, until the stop washer 38 limited by a stop against the pipe section 40 of the of impact sleeve 39 occurs. This is a compression of the caught between the stop plate 38 and stop sleeve 39 se plastic part 37th

As a result of this configuration, any formation 41 that may occur in the end region of the expansion element 11 facing the tie rod head 12 , which formation can occur at high pressures, is limited by a resulting bead 42 of the expansion transition element 36 .

In the foot region 17 , a critical bulge of the expansion element 11 - as in the first embodiment, too - is counteracted by the bordering in stage 16 .

Figs. 14 to 20 show a third embodiment of the expansion tool 1, wherein according to 9 in Beauf r deposition direction before this arranged printing plate 34 has the second embodiment of a counter-holder. Here too, a force limiting device 35 is arranged between the pressure plate 34 and the counter-holder 9 , which has a higher rigidity than the expansion element 11 .

Within the counter-support 9, a stamper 43 is received in this execution example, which - as shown - extends in the axial direction over the open end of the cup-shaped holder. 9

The matrix element 43 is divided in the longitudinal direction and is composed of four sub-matrices 44 with cross-sectional sectors.

The matrix element 43 or its partial matrices 44 are shaped towards the expansion area, ie toward the tube 7 to be expanded, in accordance with the desired expansion geometry. Accordingly, each partial die 44 has an expansion section 49 and a contact section 50 , the transition between expansion section 49 and contact section 50 extending at an acute angle of approximately 30 ° to the longitudinal axis.

On the inside of the wall, the counter-holder 9 is provided with two guide bevels 45 , 46 spaced apart from one another in the axial direction, which run at an angle of approximately 45 ° to the longitudinal axis of the expanding tool 1 . Here, the pot base 15 facing guide slope 45 is arranged with a smaller radial distance to the tie rod 10 than the pot bottom 15 lying guide bevel 46 .

The matrix element 43 or the partial matrices 44 have in the area encompassed by the counter-holder 9 , wall-shaped and positioned guide projections 47 , 48 corresponding to the guide bevels 45 , 46 . In an unloaded initial position shown in FIGS. 14 and 15, the guide projections 47, 48 of sub-arrays 44 on the guide slopes 45, 46 of the counter holder 9 abut.

Each sub-die 44 also has, in the end region facing the pot bottom 15 of the counter-holder 9, a driving section 51 which projects radially inward in the direction of the pull rod 10 and which, with the interposition of disks 52 which can be freely displaced in the axial direction on the pull rod 10 , in the axial direction on the one hand through the expansion element 11 and on the other hand is acted upon by a compression spring 53 supported on the pot base 15 .

The arrangement of the partial matrices 44 in the starting position according to FIGS. 14 and 15 is selected such that the side surfaces of the partial matrices 44 to be facing one another leave a gap between them at a distance from one another. Furthermore, the radially inner end edge of the entrainment sections 51 is also spaced apart from the pull rod 10 .

In order to insert a pipe end 7 inserted into the free annular space between the tie rod 10 and the partial matrices 44 , the push rod elements 25 or plunger 26 are also acted upon in the direction of movement r in this exemplary embodiment. Accordingly, the counter-holder 9 is displaced via the pressure plate 34 and the force limiting device 35 against the anchored tie rod 10 .

In the course of this shift, sections 51 of the partial matrices 44 entrained via the counter-holder 9 compress the expansion element 11 , this entrainment of the partial matrices 44 taking place to a point in which the force of the expansion element 11 acting on the driving portions 51 is greater than the sections 51 acting in the opposite direction on the entrainment force of the compression spring 53rd This has a relative displacement of the partial dies 44 relative to the counter-holder 9 , with the guide projections 47 , 48 and the guide bevels 45 , 46 causing an axially parallel radial displacement of the partial dies 44 in the direction of the pull rod 10 . This displacement of the partial matrices 44 radially inward is limited by the abutment of the contact sections 50 on the outer wall of the pipe to be expanded and / or by the application of the side surfaces of the submatrices 44 facing one another.

In the course of the forward displacement of the counter-holder 9 , the expansion element 11 is further compressed. As a result, the pipe end 7 is pressed into the contact sections 50 of the submatrices 44 and expanded.

As can be seen in particular from the sectional view in FIG. 18, the partial matrices 44 are supported radially outward on the flat pot wall of the counter-holder 9 formed between the guide bevels 45 and 46 , so that a radial evasion of the pipe end 7 is outside of the desired expansion zone is counteracted. As a result, a controlled widening of the tube end 7 , which is predefined by the shaping of the partial dies 44, is made possible.

After the expansion, the pressing device 2 automatically moves back to its starting position, the counter-holder 9 is moved back into the starting position via the driving sections 51 of the partial dies 44 , due to the elastic return properties of the expanding element 11 . Subsequently, the sub-matrices 44 are initially still in their radially inward position, but this is done without any radially outer support by the cup wall of the counter-holder 9 . The pipe end 7 can then be pulled in a technical manner in the axial direction from the expansion tool 1 , this with displacement of the part dies 44 radially outward, due to the bevels between the expansion portions 49 and contact portions 50 formed, which is also shown in the Set the pipe end 7 . It turns hereinafter the starting position according to FIG. 14 and 15 of the tool 1 a Aufweitwerk.

Advantageously, the expansion tool described 1 can be arranged on a conventional pressing device 2 .

All features disclosed are (by themselves) fiction sentlich. In the disclosure of the application is here with also the disclosure content of the associated / attached priority documents (copy of the pre-registration) fully included, also for the purpose, Merk times of these documents in claims of the present application to include.

Claims (30)

1. expanding tool ( 1 ) for expanding pipe ends ( 7 ), the expanding tool ( 1 ) having an expanding mandrel ( 8 ) and a counter-holder ( 9 ), the expanding mandrel ( 8 ) comprising a pull rod ( 10 ) and one of these surrounding elastic rubber expansion element is (11) be, and the counter-holder (9) on the foot side supporting the expansion element (11) and radially spaced surrounding, characterized in that the pull rod (10) in a bolt-fastening element is anchored (20) and that the counter-holder ( 9 ) via a push rod element ( 25 ) can be acted upon, the rod in the longitudinal direction of the train ( 10 ) protrudes beyond the bolt fastening element ( 20 ). 2. Expanding tool according to claim 1 or in particular according thereto, characterized in that the bolt fastening supply element ( 20 ) has a transverse to the axial direction of the train rod ( 10 ) extending bolt receiving bore ( 23 ). 3. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the push rod element ( 25 ) is fastened in the counter-holder ( 9 ). 4. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the push rod element ( 25 ) passes through the bolt fastening element ( 20 ). 5. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the push rod element ( 25 ) is designed like a plunger. 6. expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that more than two Dnickel rod elements ( 25 ) are provided. 7. expanding tool according to one or more of the preceding claims or in particular according thereto, wherein the counter-holder ( 9 ) is cup-shaped, characterized in that in the pot bottom ( 15 ) on the inside a step ( 16 ) is formed which a Fußbe rich ( 17th ) of the expansion element ( 11 ). 8. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the step ( 16 ) serves on the upper side as a stop for a pipe to be expanded. 9. expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that in the bolt fastening element ( 20 ) for fastening the pull rod ( 10 ) a screw-in adapter part ( 31 ) is provided for adaptation to under different pull rods -Diameter. 10. expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that in the direction of action (r) in front of the counter-holder ( 9 ) a pressure plate ( 34 ) is arranged, on which the push rod elements ( 25 ) act and that between the Pressure plate ( 34 ) and the Gegenhal ter ( 9 ) a force limiting device ( 35 ) is net angeord. 11. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the force limiting device ( 35 ) consists of a plastic part. 12. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the plastic part has a higher rigidity than the expanding element ( 11 ). 13. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that an expansion transition element ( 36 ) is arranged downstream in the direction of action (r) to the expansion element ( 11 ), but nevertheless also caught by the pull rod ( 10 ) is. 14. expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the expanding transition element ( 36 ) consists of a stop-compression-limited plastic part ( 37 ). 15. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the stop compression consists of a stop sleeve ( 39 ) which can be moved against a widening element ( 11 ) limiting the stop disk ( 38 ). 16. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the stop sleeve ( 39 ) has a sleeve base which is acted upon by a tie rod head ( 12 ) and which surrounds the tubular section ( 40 ) in a tie rod ( 10 ) ) transforms. 17. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that a matrix element ( 43 ) is received within the counter-holder ( 9 ). 18. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the die element ( 43 ) divided in the longitudinal direction is composed of a plurality of sub-dies ( 44 ). 19. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that the die element ( 43 ) engages under the elastic elastic expander element ( 11 ). 20. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that a partial die ( 44 ) in the course of pressing from a removal position for the pipe end to be expanded ( 7 ) by axial displacement into a pressing position while reducing the radial distance is shiftable to the tie rod ( 10 ). 21. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that a guide bevel ( 45 , 46 ) is formed on the inside on the counter-holder ( 9 ), which is provided with a guide projection ( 47 , 48 ) of the die element ( 43 ) interacts. 22. Expanding tool according to one or more of the preceding claims or in particular according thereto, characterized in that two mutually spaced guide bevels ( 45 , 46 ) are arranged in the radial direction at differing radial distances from the pull rod ( 10 ). 23. Press device ( 2 ) with an expanding tool ( 1 ) for expanding pipe ends ( 7 ), the expanding tool ( 1 ) having an expanding mandrel ( 8 ), which consists of a pull rod ( 10 ) and an elastic rubber expanding element surrounding it ( 11), further comprising a counter-holder (9) which supports the expansion element (11) on the foot side and radially surrounds at a distance, characterized in that the pull rod (10) is fixedly connected to the pressing device (2), while the counter-holder ( 9 ) is acted upon by a push rod element ( 25 ). 24. Press device according to claim 23 or in particular since, characterized in that the pull rod ( 10 ) is anchored in a bolt fastening element ( 20 ). 25. Press device according to one or more of claims 23 to 24 or in particular according thereto, characterized in that the push rod element ( 25 ) in the longitudinal direction of the pull rod ( 10 ) protrudes beyond the bolt fastening element ( 20 ). 26. Press device according to one or more of claims 23 to 25 or in particular according thereto, characterized in that the bolt fastening element ( 20 ) has a bolt receiving bore ( 23 ) extending transversely to the axial direction of the pull rod ( 10 ). 27. Press device according to one or more of claims 23 to 26 or in particular according thereto, characterized in that the push rod element ( 25 ) passes through the bolt fastening element ( 20 ). 28. Press device according to one or more of claims 23 to 27 or in particular according thereto, characterized in that more than two push rod elements ( 25 ) are provided. 29. Press device according to one or more of claims 23 to 28 or in particular according thereto, characterized in that the push rod element ( 25 ) is designed as a single-lying, with the counter-holder ( 9 ) not connected plunger ( 26 ). 30. Press device according to one or more of claims 23 to 29 or in particular according thereto, characterized in that the press device ( 2 ) acts on the plunger ( 26 ) via rollers ( 6 ).