EP4093601B1 - Radial press - Google Patents

Description

The present invention relates, as stated in the preamble of claim 1, to a radial press with a housing having a jacket section and an end-side annular support disk, a ring structure guided therein in a displaceable manner along a press axis and a plurality of press jaws arranged around the press axis, which are located radially on the support disk slidably guided and on which the ring structure acts by means of control surfaces inclined relative to the press axis, which rest on counter surfaces of the press jaws designed as sliding surfaces.

Radial presses of the generic type described above are from the patent literature (e.g. DE 28 44 475 A1 , WO 2005/077566 A1 , US 6,857,305 B2 , US 2011/0185784 A1 , WO 02/07912 A2 and WO 2017/178508 A1 ) known. Also the US 2014/0331734 A1 , which represents the closest prior art, discloses a generic radial press corresponding to the preamble of claim 1. The ring structure, which can be moved in the housing along the press axis, has an annular projection on the front side - limited by a conical outer surface and a conical inner surface, with helical teeth with a sawtooth profile being designed on the conical inner surface, which work in cooperation with corresponding ones on the pressing jaws Gears ensure a gradual rotation of the latter around the press axis.

The US 3,427,036 A discloses a clamping device that works according to a functional principle comparable to generic radial presses. And from the EP 1 302 255 A1 A radial press is known in which a pressure ring acting on the press jaws via wedge bevels has an annular hydraulic cylinder into which an annular piston is immersed, which in turn is connected to an annular support disk on the front via tie rods on which the pressure ring is slidably guided.

These radial presses have also proven themselves in practice for various applications in which the special advantages such as the very compact design come into play. This applies to both single-stage and two-stage radial presses of this design. Single-stage radial presses are those in which the axial movement of the ring structure causes a radial feed movement of the press jaws over the entire displacement path, which is in a fixed relationship to the axial movement of the ring structure. In contrast, in two-stage radial presses there is a translation of the axially directed movement of the ring structure into a radially directed movement of the press jaws, which changes over the displacement path of the ring structure. This makes it possible to realize radial presses that can press with a comparatively high force - on part of the pressing process - with a comparatively small axial length; because the feed movement of the pressing jaws from the open position of the tool takes place in a first phase of the pressing process (during the so-called "rapid traverse") - corresponding to a relatively steep angle of attack of the control surfaces - on a relatively short displacement path of the ring structure, whereas in a second phase of the pressing process (during the so-called "force cycle") - corresponding to a relatively flat angle of attack of the control surfaces - the feed movement of the pressing jaws takes place on a relatively long displacement path of the ring structure. The rapid traverse is not only useful because more displacement path of the ring structure remains for power pressing; it also contributes to the shortest possible cycle times and thus forms a point of efficiency when using the radial press.

The present invention is aimed at providing a radial press of the generic type that is further and further improved in terms of practicality compared to the prior art set out above. One of the relevant aspects concerns a particularly favorable ratio of the three variables: effective pressing force, maximum pressing path (maximum possible radial feed movement of the pressing jaws) and overall length of the radial press. Another aspect of practical suitability is the suitability of the radial press in question for tasks that lie outside of usual standard applications, i.e. H. a wide possible range of applications.

The above problem is solved according to the present invention in that - in a radial press of the generic type - the ring structure is designed in a crown shape on its end face facing the support disk with a number of axial projections corresponding to the number of press jaws, with each control surface in the radial inner surface one such a projection extends into it and furthermore the support disk has recesses assigned to the projections, into which the projections enter when the radial press is closed.

In a surprisingly simple manner, by implementing the present invention, the relationship between the effective pressing force, maximum pressing path and radial press length can be optimized to one another to an appreciable extent. Because - compared to generic radial presses according to the prior art - the overall length remains unchanged, the effective lengths of the control surfaces can be significantly increased in radial presses according to the invention. Depending on the individual design, the maximum pressing path can be increased - with the angle of inclination of the control surfaces remaining unchanged - and/or - the maximum pressing force can be increased - if the angle of inclination of the control surfaces is reduced. As a result, for certain application situations in which two-stage radial presses were previously required, the use of single-stage radial presses according to the invention can even be considered; Since single-stage radial presses, for example in terms of the design of the sliding partners, are significantly less complex than two-stage radial presses, this is a significant advantage. Viewed from a different perspective, the design of the radial press according to the invention has the advantage that (because of the larger overlap of control surfaces and countersurfaces compared to the prior art) significant pressing forces can be applied to a workpiece even when the tool is wide open, without the danger exists that the pressing jaws tilt radially outwards. This will ensures better dimensional and dimensional stability, namely counteracts conicity of the workpiece; and damage to the tool due to local overloading (due to tilting) is avoided. In implementing the present invention - compared to generic radial presses of known design - an enlarged effective contact area can generally be provided between the control surfaces and the press jaws, which has a wear-reducing effect. In addition to the advantages set out above, the present invention also has the effect of significantly expanding the possible range of applications of the respective radial press compared to the prior art. The novel geometric relationship that can be achieved by the invention between the crown-shaped end face of the ring structure, the support disk of the housing and the pressing jaws causes the latter to be able to apply force during pressing even when the force is strongly off-center, in particular in the direction of the support disk not prone to tipping over. In radial presses according to the invention, the press jaws can be equipped in particular with press attachments, the pressing surfaces of which (possibly particularly short in the axial direction) are particularly close to the workpiece opening - provided in the support disk - without this causing the press jaws to tilt or "rock" during pressing " tend. This makes the radial press according to the invention particularly suitable for use as a so-called “calibration press”, for example.

The fact that the number of axial projections - provided on the end face of the crown-shaped ring structure facing the support disk - corresponds to the number of pressing jaws is important from a static point of view, namely with regard to a favorable flow of force within the housing with particularly uniform removal of the pressure on the support disk of the housing exerted axial force in its jacket structure is particularly advantageous.

In the sense set out above, a first preferred development of the radial press according to the invention is characterized in that press attachments with pressing surfaces offset from the axial center of the counter surfaces are attached to the pressing jaws. This can also be achieved by appropriately shaping press attachments, which are attached more or less centrally radially on the inside of the respective press jaw; However, according to a particularly preferred embodiment, the press attachments are attached to the press jaws in the area of their ends facing the support disk. From the point of view of the size of the radial press, the statics, the precision/reproducibility and the handling when changing the press attachments, it is particularly advantageous if the press attachments are inserted into front-side receptacles of the press jaws formed by corresponding recesses.

Another preferred development of the invention is characterized in that the recesses into which the projections made on the ring structure enter are designed as openings. In this In this case, the advantages set out above can be realized to a particularly pronounced extent. However, within the scope of the invention, it is not at all excluded that the recesses only extend over a significant part (e.g. 70% to 95%) of the axial thickness of the support disk, so that the recesses are closed at the end by a layer of material. This can be advantageous in individual cases, for example if - in order to avoid contamination of the environment due to control surface and/or sliding surface abrasion - a housing surface that is as closed as possible is desired.

For practical application, it is particularly useful if the advantages set out above and associated with the design of the radial press according to the invention are linked in a machine with those resulting from other design features, such as those at least partially taken from the prior art for radial presses of the generic type Type (see above) are known, resulting advantages. In this sense, particularly advantageous developments due to favorable combinatorial effects are specified in the subclaims.

For example, it is particularly favorable if the ring structure comprises a ring structure base body and replaceable sliding plates, with the control surfaces being designed on the surface of the sliding plates. The sliding plates can rest with their back facing away from the respective control surface on a support surface which is designed on the ring structure base body. In an advantageous alternative embodiment, the ring structure further comprises control bodies, which are replaceable on the Ring structure base body are attached and have support surfaces on which the sliding plates rest with their back facing away from the respective control surface. The support surfaces explained above (executed on the ring structure base body or on control bodies interchangeably attached to it) particularly preferably each comprise two support sections, which are delimited from one another by a recess lying between them. Such a defined support for the sliding plates counteracts their wobbling, even - within certain limits - when the sliding plates wear. In the case of such radial presses in which the sliding plates rest (directly) on the ring structure base body and thus also on the - in implementation of the present invention - projections on the front side of this, the recess in question particularly preferably does not extend over the respective entire projection , but ends in front of the end face of the assigned projection; In this case, the two support sections are connected to one another adjacent to the end face of the respective projection or merge into one another there.

In further use of the knowledge (already explained above) that the present invention can be used particularly advantageously in single-stage radial presses, a preferred development of the invention is characterized in that the control surfaces are flat. Particularly preferably, in planes perpendicular to the pressing axis, the control surfaces each lie on a polygon with corners arranged between two adjacent pressing jaws.

To guide the press jaws, press jaw guide ribs are particularly preferably provided on the ring structure, which laterally enclose or limit the control surfaces (at least locally). If the ring structure has separate control bodies (see above) which are interchangeably attached to a ring structure base body, press jaw guide ribs, each designed on the ring structure base body, can be provided between two such control bodies, so that the control bodies are each inserted between two press jaw guide ribs, which protrude radially inwards (at least locally) over the control bodies, ie over the control surfaces designed on them, in order to guide the pressing jaws. According to another particularly advantageous embodiment, first guide elements (e.g. in the form of guide grooves) are designed on the press jaw guide ribs explained above, into which corresponding second guide elements (e.g. in the form of guide projections) designed on the press jaws engage. In this way, a forced guidance of the pressing jaws on the ring structure can be realized in the sense that during the return stroke of the ring structure, their movement (without the support of return springs) forces the opening of the pressing jaws. Such positive guidance of the press jaws in turn counteracts their tilting in the event of a strongly eccentric load, in particular when force is introduced very close to the support disk, and in this way supports the positive effects of the design of the radial press according to the invention (see above).

According to yet another preferred development of the invention, the ring structure comprises an annular piston which is sealingly guided in a press cylinder section designed in the jacket section of the housing and, together with this, delimits an annular press working space. At its end opposite the annular piston, the press working space can be delimited by a housing closure ring arranged opposite the support disk, in particular if - according to a preferred development of the invention - the support disk and the jacket section are part of a one-piece housing base structure, in which a sleeve-shaped extension of the ring structure - which delimits the press working space radially on the inside - is guided in a sealing manner. In the interest of a fully hydraulic drive for the movement of the ring structure, an annular return stroke working space is particularly preferably arranged between the press working space and the support disk. This can be limited with particular advantage by a cylinder surface arranged on the outer circumference of the ring structure and guided in a sealing collar fixed to the housing.

With particular advantage, the return stroke working space is delimited by the press cylinder section and an annular zone formed on the annular piston on its end face facing away from the press working space. This means that only a single, continuous cylinder surface is required on the housing for both hydraulic work spaces, which facilitates simple and cost-effective production of the radial press.

Fig. 1

einen Axialschnitt durch eine nach der Erfindung ausgeführte einstufigen Radialpresse bei vollständig geöffnetem Werkzeug,

Fig. 2

einen Axialschnitt durch die Radialpresse nach Fig. 1 bei vollständig geschlossenem Werkzeug und

Fig. 3

eine perspektivische Ansicht des Ringstruktur-Grundkörpers der Radialpresse nach den Figuren 1 und 2.

The present invention is explained in more detail below using an exemplary embodiment illustrated in the drawing. This shows

Fig. 1

an axial section through a single-stage radial press designed according to the invention with the tool completely open,

Fig. 2

an axial section through the radial press Fig. 1 with the tool completely closed and

Fig. 3

a perspective view of the ring structure base body of the radial press according to the Figures 1 and 2 .

The hydraulic radial press shown in the drawing comprises, as its main components, a substantially rotationally symmetrical housing 1, a ring structure 2 which is displaceably guided therein along the axis Basic structure 5 with a jacket section 6 and an end-side annular support disk 7 as well as a housing locking ring 8 arranged opposite the support disk 7 in the jacket structure and fixed there. The pressing jaws 3 are supported by means of two screws 9 attached to the support disk 7 Guide grooves 10 provided on the press jaws 3 are guided in a radially displaceable manner - on the support disk 7, with a friction-reducing bearing plate 12 being arranged between the end faces of the press jaws 3 and the support disk 7. The pressing jaws 3 have sliding surfaces 13 on the radial outside. These form countersurfaces to the ring structure 2, which are inclined relative to the press axis .

To the extent set out above, the radial press corresponds to the Figures 1 to 4 the well-known state of the art disclosed in the documents presented in the introduction to which reference is made, so that further explanations are not required.

The ring structure 2 has a ring-shaped, closed ring structure base body 15 and eight flat sliding plates 16 which are replaceably attached to it. The sliding plates 16 are fixed to the ring structure base body 15 by means of a clamping ring 18 acting on the end edges 17 of the sliding plates 16. The sliding plates 16 each lie - with their back facing away from the respective control surface 13 - on an assigned, also essentially flat support surface 19 of the ring structure base body 15. The support surfaces 19 each include two support sections 20, 21, which are delimited from one another by a recess 22 between them.

On its end face 23 facing the support disk 7, the ring structure base body 15 is crown-shaped in that it has eight axial projections 24 there. The support surfaces 19 serving to support the sliding plates each extend into the radial inner surface 25 of such a projection 24; and The sliding plates 16 resting on the support surfaces 19 also extend accordingly, so that as a result each control surface 14 also extends into the radial inner surface 25 of the respectively assigned projection 24. The depressions 22 can, in a modification to that in Fig. 3 shown embodiment, each end in front of the end face 26 of the associated projection 24. Can be seen in Fig. 3 the press jaw guide ribs 27, which are designed on the ring structure base body 15 - each between two mutually adjacent support surfaces 19 - with the guide grooves 39 provided on them, which are intended to cooperate with corresponding guide projections provided laterally on the press jaws.

The support disk 7 has eight recesses 28 corresponding to the projections 24 of the ring structure 2 and assigned to them, into which the projections 24 enter when the radial press is closed (cf. Fig. 2 ). The recesses 28 are designed as openings 29, which each open into an opening 31 on the free end face 30 of the support disk 7.

A double-acting hydraulic drive is used to move the ring structure 2. For this purpose, the ring structure 2 comprises an annular piston 32, which is sealingly guided in a cylinder section 33 designed in the jacket section 6 of the housing 1. The cylinder section 33, the annular piston 32, the housing closure ring 8 and a sleeve-shaped extension 34 of the ring structure base body 15, which is guided sealingly therein, together delimit an annular press working space 35. This is via a press connection 40 actuable. An annular return stroke working space 36 is arranged between the press work space 35 and the support disk 7. This is limited by the cylinder section 33 - which also delimits the press working space 35, an annular zone formed on the annular piston 32 on its end face facing away from the press working space 35, a sealing collar 37 fixed to the housing and a sealing collar 37 guided in this on the outer circumference of the ring structure base body 15 arranged cylinder surface 38. The return stroke working space 36 can be acted upon via a return stroke connection 41.

The exemplary embodiment illustrated in the drawing is a so-called calibration press. For this purpose, the pressing jaws 3 are designed in a specific manner in that they each have a recess 42 on their end face facing the support disk 7. This forms a receptacle 43 for a press attachment 45 inserted into it and fixed by means of the screw 44. On the press attachment 45, a press surface 47 - intended for interaction with the workpiece to be pressed - is provided radially on the inside on a narrow, inwardly directed collar 46. The arrangement of the pressing surfaces 47 is clearly visible immediately adjacent to the support disk 7 and is therefore particularly offset from the axial center M of the counter surfaces 13 of the pressing jaws 3.

However, it can also be seen that a modification of the radial press shown is easily possible in such a way that the (modified) press jaws 3 can be replaced radially on the inside in a conventional manner known as such - to change the press diameter Press attachment (with a differently designed pressing surface depending on the pressing task) is attached.

Claims (21)

1. A radial press with a housing (1) having a jacket portion (6) and an end-face annular bracing disk (7), an annular structure (2) guided displaceably therein along a press axis (X) and several press jaws (3), which are disposed around the press axis (X) and which are braced in radially displaceably guided manner on the bracing disk (7) and on which the annular structure (2) acts by means of control faces (14), which are inclined relative to the press axis (X) and bear against mating faces of the press jaws (3) constructed as sliding faces (13), characterized in that
   the annular structure (2) is constructed in crown-shaped manner on its end face (23) turned toward the bracing disk (7) and has a number of axial projections (24) corresponding to the number of press jaws (3), wherein each control face (14) extends into the radial inner face (25) of such a projection (24) and wherein further the bracing disk (7) has recesses (28), which are associated with the projections (24) and into which the projections (24) are inserted during closing of the radial press.
2. The radial press of claim 1, characterized in that the recesses (28) are constructed as through holes (29).
3. The radial press of one of claims 1 or 2, characterized in that press attachments (45) having pressing faces (47) offset relative to the axial center (M) of the mating faces (13) are mounted on the press jaws (3).
4. The radial press of claim 3, characterized in that the press attachments (45) are mounted on the press jaws (3) in the region of their ends turned toward the bracing disk (7).
5. The radial press of claim 4, characterized in that the press attachments (45) are inserted into end-face receptacles (43) of the press jaws (3).
6. The radial press of one of claims 1 to 5, characterized in that the annular structure (2) comprises an annular-structure base body (15) and exchangeable sliding plates (16), wherein the control faces (14) are constructed on the surface of the sliding plates (16).
7. The radial press of claim 6, characterized in that the sliding plates (16) bear with their rear side turned away from the respective control face (14) on a bracing face (19), which is constructed on the annular-structure base body (15).
8. The radial press of claim 6, characterized in that the annular structure (2) further comprises control bodies, which are mounted exchangeably on the annular-structure base body (15) and have bracing faces, on which the sliding plates (16) bear with their rear side turned away from the respective control face (14).
9. The radial press of claim 7 or claim 8, characterized in that the bracing faces (19) respectively comprise two support portions (20, 21), which are separated from one another by a depression (22) situated between them.
10. The radial press of claim 9, characterized in that the depression (22) tapers out respectively before the end face (26) of the associated projection (24).
11. The radial press of one of claims 1 to 10, characterized in that the control faces (14) bear, in planes perpendicular to the press axis (X), respectively on a polygon having corners disposed respectively between two mutually adjacent press jaws (3).
12. The radial press of claim 11, characterized in that the radial press is a one-stage radial press, wherein the control faces (14) are of flat construction.
13. The radial press of claim 11, characterized in that the radial press is a two-stage radial press, wherein the control faces (14) are of stepped construction.
14. The radial press of one of claims 1 to 13, characterized in that press jaw guide ribs (27) constructed respectively on the annular structure (2) are provided between two press jaws (3).
15. The radial press of claim 14, characterized in that first guide elements, preferably guide slots (39), in which corresponding second guide elements constructed on the press jaws (3) engage, are constructed on the press jaw guide ribs (27).
16. The radial press of one of claims 1 to 15, characterized in that the annular structure (2) comprises an annular piston (32), which is guided sealingly in a press-cylinder portion (33) constructed in the jacket portion (6) of the housing (1) and together with this bounds an annular press working chamber (35).
17. The radial press of claim 16, characterized in that an annular return-stroke working chamber (36) is disposed between the press working chamber (35) and the bracing disk (7), and is bounded by a cylindrical face (38) disposed on the outer circumference of the annular structure (2) and guided in a sealing shoulder (37) integral with the housing.
18. The radial press of claim 17, characterized in that the jacket portion (6) of the housing (1) has a debris discharge opening between the sealing shoulder (44) and the bracing disk (7).
19. The radial press of one of claims 16 to 18, characterized in that the press working chamber (35) is bounded by a housing-closure ring (8) disposed opposite the bracing disk (7) and a sleeve-like extension (34) of the annular structure (2) guided sealingly in it.
20. The radial press of one of claims 1 to 19, characterized in that the bracing disk (7) and the jacket portion (6) are part of a one-piece housing base structure (5).
21. The radial press of one of claims 1 to 20, characterized in that exchangeable guide elements (11) cooperating with the press jaws (3) are mounted on the bracing disk (7).

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