Radialpresse

Abstract

The present invention relates to a radial press (1) with a housing (2) comprising a shell section (6) and an annular support disc (7) at its end face. A ring structure (3) is slidably guided along a press axis (X) within the housing (2), and several press jaws (4) are arranged around the press axis (X). The press jaws (4) are supported on the support disc (7) and are guided radially slidably. The ring structure (3) acts on the press jaws (4) by means of control surfaces (15) inclined relative to the press axis (X), the control surfaces (15) bearing against counter surfaces of the press jaws (4) designed as sliding surfaces (27). The inclination angle of the control surfaces (15) changes along their course in the axial direction such that, over the (maximum) movement path of the ring structure (3), the axial movement of the ring structure (3) and the radial movement of the press jaws (4) caused by this are in different ratios to each other.In a projection plane (V) perpendicular to the press axis (X), the control surfaces (15) each have at least one first section (A1S) with a first angle of inclination (W1) and at least one second section (A2F) with a second angle of inclination (W2), wherein the first angle of inclination (W1) is greater than the second angle of inclination (W2).

Description

[0001] The present invention relates to a radial press with a housing comprising a shell section and an annular support disc at its end face. A ring structure is slidably guided along a press axis within the housing, and several press jaws are arranged around the press axis. The press jaws are supported on the support disc and are guided radially slidably. The ring structure acts on the press jaws by means of control surfaces inclined relative to the press axis, the control surfaces bearing against opposing surfaces of the press jaws designed as sliding surfaces. The angle of inclination of the control surfaces changes along their axial path such that, over the (maximum) travel of the ring structure, the axial movement of the ring structure and the resulting radial movement of the press jaws are in different ratios to each other.

[0002] Radial presses of the generic type described above are known from practical application as well as from patent literature (e.g., DE 2 844 475 A1, WO 2005 / 077566 A1, US 2011 / 0185784 A1 and DE 10 2016 106650 A1). By converting the axial movement of the ring structure into a radial movement of the press jaws via the displacement path (trajectory) of the ring structure, radial presses can be realized that can press with comparatively high force despite a comparatively short axial length. This is because the approach movement of the press jaws from the open position of the tool initially occurs 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 – over a relatively short displacement path of the ring structure, whereas in a second phase of the pressing process (during the so-called "delayed traverse")...“Kraftgangs”) then - corresponding to a relatively shallow angle of attack of the control surfaces - the feed movement of the press jaws takes place over a relatively long displacement path of the ring structure.

[0003] During rapid traverse, sections of the control surfaces with a relatively steep angle of attack (large inclination angle) are in contact with corresponding sections of the sliding surfaces of the press jaws, so that an axial movement of the ring structure causes a relatively large radial movement of the press jaws. In force traverse, however, sections of the control surfaces with a relatively shallow angle of attack (small inclination angle) are in contact with corresponding sections of the sliding surfaces of the press jaws, so that an axial movement of the ring structure causes a relatively small radial movement of the press jaws. Between the contacting sections of the control surface and the corresponding sections of the sliding surfaces, radially inward-directed forces are transmitted (radial forces), which move the press jaws radially inward and thus result in the workpiece being compressed.

[0004] Rapid traverse is not only useful because it leaves more displacement space for the ring structure to be used for force pressing; it also contributes to the shortest possible cycle times and thus represents an aspect of efficiency when using the radial press.

[0005] A challenge for radial presses in general, and radial presses of this type in particular, lies in producing workpieces that exhibit a high degree of cylindricity or a low degree of conicity in the pressed area. This is especially true when pressing a short workpiece, when the radial forces are introduced unevenly into the press jaws, and / or when the workpiece is positioned off-center relative to the press jaws, thus significantly increasing the risk of the press jaws tilting.

[0006] In a narrower sense, taper refers to the change in diameter of a cone along its longitudinal axis. In this document, taper is understood more generally as the change in the cross-section of a workpiece along its longitudinal axis. Accordingly, the cross-section of a workpiece with low taper changes very little along its longitudinal axis, while it varies considerably in a workpiece with high taper.

[0007] The present invention is directed to provide a radial press of the generic type that is improved compared to the prior art described above. In particular, the radial press should be suitable for producing workpieces that are characterized by an extremely low degree of taper in the pressed area.

[0008] This problem is solved by the radial press according to claim 1. Preferred embodiments are the subject of the dependent claims.

[0009] Starting from a generic radial press, the invention is characterized in that in a (thoughtful) projection plane perpendicular to the press axis, the control surfaces each have at least one first section with a first angle of inclination and at least one second section with a second angle of inclination, wherein the first angle of inclination is greater than the second angle of inclination.

[0010] The first and second sections of the control surfaces are thus located in the same projection plane perpendicular to the press axis, i.e. at a common position of the ring structure with respect to its axial extent (axial position); however, the first and second sections of the control surfaces are arranged offset from each other in the circumferential direction of the ring structure.

[0011] The first sections of the control surfaces with the first, larger angle of inclination (also called steep sections) are in contact with the sliding surfaces of the press jaws during rapid traverse and transmit the radial forces that move the press jaws inwards; the second sections of the control surfaces with the second, smaller angle of inclination (also called flat sections) function analogously during force traverse. The contours of the press jaws are designed with appropriately arranged recesses such that during rapid traverse, i.e., when the sliding surfaces of the press jaws are in contact with the steep sections of the control surfaces, there is a gap and therefore no contact between the flat sections of the control surfaces and the press jaws.

[0012] Typically, in radial presses of this type - as shown, for example, in DE 10 2016 106 650 A1 - the steep sections of the control surfaces are arranged closer to the support ring or to the press opening than the flat sections of the control surface.

[0013] The invention is based on the finding that by the axial "forward displacement" of the flat sections of the control surface into the projection plane, i.e., into the area where otherwise only the steep sections of the control surface are arranged, it can be achieved that (especially immediately after the transition from rapid traverse to power traverse) the radial forces can be transferred from the ring structure to the press jaws closer to the press opening (or closer to the support ring).

[0014] This allows radial forces to be applied to the press jaws over a larger axial area of ​​the control surfaces, thereby reducing the tendency of the press jaws to tilt and thus the taper of the pressed workpieces. This effect is particularly noticeable when pressing a workpiece that is shorter in the axial direction than the press jaws and / or positioned off-center with respect to the press jaws.

[0015] Furthermore, the inventive "forward displacement" of the flat sections of the control surface into the projection plane increases the size of the control surface that, during force transmission, is in contact with the sliding plane of the press jaws and via which the radial forces are transmitted to the press jaws. This enlargement of the force-transmitting area reduces the pressure acting on the surface, which advantageously reduces wear.

[0016] The angle of inclination of the control surface refers in particular to the angle that spans between a section of the control surface and the press axis.

[0017] According to a first preferred embodiment of the invention, the at least one first section and the at least one second section are each configured as a planar ramp of the control surface. A planar ramp is understood to be a ramp whose ramp surface is configured as a flat surface.

[0018] In this way, a radial press can be provided in which the control surfaces of the ring structure and the corresponding sliding surfaces of the press jaws can be manufactured simply and cost-effectively due to their geometrically simple, flat ramp shape.

[0019] Furthermore, this allows – according to another advantageous embodiment – ​​for the control surfaces of the ring structure and the sliding surfaces of the press jaws to be in contact across their entire width in the area of ​​flat surfaces, at least during certain operating positions. This requires that the sliding surfaces of the press jaws, corresponding to the control surfaces of the ring structure, are also designed as flat ramps with corresponding angles of inclination.

[0020] In particular, compared to control surface geometries where the ring structure and the press jaws only come into contact along contact lines or contact points, this reduces localized pressure or stress peaks, which benefits the sliding behavior of the press jaws on the ring structure and reduces wear.

[0021] Furthermore, this enables - according to a preferred embodiment of the invention - at least during individual operating positions of the ring structure, its control surfaces and the sliding surfaces of the press jaws to lie flat against each other over their entire width in the area of ​​flat surfaces.

[0022] In a particularly advantageous manner, the at least one second section in the area of ​​the projection plane is designed as a projection (as a nose). Furthermore, it can be provided that the at least one second section in the area of ​​the projection plane is designed as a projection centrally between two first sections.

[0023] The contours of the press jaws have corresponding bulges, which are arranged and designed in such a way that the projections formed by the second sections in the area of ​​the projection plane do not come into contact with the press jaws during rapid traverse.

[0024] The present invention can be implemented with particular advantage in radial presses in which the control surfaces each have a third section that is arranged parallel to the at least one first section and a fourth section that is arranged parallel to the at least one second section.

[0025] In this way, the press jaws can be doubly supported in two axially offset planes (or sections), which significantly reduces the risk of the press jaws tilting, especially when the workpiece is positioned off-center. Adjacent flat sections can transition seamlessly into one another, i.e., via transition radii.

[0026] Naturally, the sliding surfaces of the press jaws must be designed accordingly, so that in rapid traverse not only the first sections but also the third sections of the control surface are in contact with the sliding surfaces of the press jaws, and so that in power traverse not only the second sections but also the fourth sections of the control surfaces are in contact with the sliding surfaces of the press jaws.

[0027] According to a further advantageous embodiment of the radial press according to the invention, the ring structure has a base structure and interchangeable control bodies included therein, wherein the control surfaces are provided on the control bodies.

[0028] A particular advantage of this design lies in the easy and straightforward adaptability of the press jaws' feed movement characteristics to the specific pressing task. By replacing the control elements (possibly while simultaneously replacing the press jaws), it is possible, for example, to influence the distribution of the total press jaw feed between rapid traverse and pressing stroke, as well as (via the inclination angle of the control surfaces) the maximum pressing force.

[0029] Furthermore, the design of the ring structure, comprising a base structure and interchangeable control bodies with control surfaces mounted thereon, offers manufacturing advantages. The control bodies are preferably positioned along a flat support surface on the base structure (particularly from a manufacturing perspective). These flat support surfaces can be inclined or extend parallel to the press axis, with the latter case the control bodies being, in principle, more or less wedge-shaped.

[0030] According to another preferred embodiment, the control elements, however, lie flat against a convex support surface of the base structure. Here, too, the support surfaces can converge in the axial direction, for example by being formed on the surface of a truncated cone, or they can be non-convergent, for example by forming the support surfaces on the surface of a cylinder.

[0031] Yet another preferred embodiment of the invention, particularly advantageous from a manufacturing perspective, is characterized in that the control bodies each have a base plate abutting the base structure and a hump mounted thereon in sections. This applies at least to the embodiment already described above, in which the control surfaces have four sections offset from each other in pairs.

[0032] In this embodiment, it is particularly advantageous if the control surfaces are located on the surface of replaceable sliding plates. These sliding plates can be made of a material ideally suited to their specific function. Furthermore, in the event of advanced wear or damage (by a foreign object), the individual sliding plates can be replaced with minimal effort. Since increased wear is to be expected, especially in the initial sections of the control surfaces, this embodiment of the invention offers particular advantages.

[0033] An embodiment of the invention will now be explained in more detail with reference to the drawing. The drawing shows Fig. 1 an axial section through a radial press according to the invention with the tool open at the beginning of rapid traverse, Fig. 2A - 2C each have a radial press according to the invention during different operating phases, wherein the radial press is in Fig. 2A at the beginning of the rapid traverse, in Fig. 2B during the course of the power transmission and in Fig. 2C is shown towards the end of the power cycle, Fig. 3 a perspective view of a previously known control body of a generic radial press, and Fig. 4A & 4B a control body of a radial press according to the invention in a perspective oblique view ( Fig. 4A) and a side view ( Fig. 4B).

[0034] The Fig. Figures 1 to 2C each show the same embodiment of a radial press according to the invention in a side sectional view. Fig. 1 and Fig. 2A are identical except for the scale of representation. Fig. Figures 2A to 2C show the radial press according to the invention during various operating phases, wherein the radial press is in Fig. 2A at the beginning of the rapid traverse, in Fig. 2B during the course of the power transmission and in Fig. 2C is shown towards the end of the power cycle.

[0035] The in the Fig. The radial press 1 according to the invention, shown in a sectional view in sections 1 to 2C of the drawing, comprises as its main components a substantially rotationally symmetrical housing 2, a ring structure 3 which is slidably guided therein along the axis X and a press tool 5 having eight press jaws 4 arranged around the press axis X.

[0036] The housing 2 comprises a shell section 6, an annular support disc 7 arranged at the end face, and a housing locking ring 8 arranged opposite the support disc 7 in the shell section 6 and fixed there.

[0037] The ring structure 3 can be displaced within the housing 2 along the press axis X. If the first piston ring chamber 9 is pressurized with hydraulic fluid via the first inlet 10, the ring structure 3 moves towards the support disc 7. Conversely, if the second piston ring chamber 11 is pressurized with hydraulic fluid via the second inlet 12, the ring structure 3 moves in the opposite direction towards the housing locking ring 8.

[0038] The ring structure 3 has a ring-shaped closed base structure 13 and eight interchangeably mounted control bodies 14 on which control surfaces 15 are provided.

[0039] The control bodies 14 - see also the Fig. 4A and Fig. 4B - are themselves multi-part, each comprising a (in this case essentially flat) base plate 17 and a sectionally mounted hump 18 as well as two - interchangeably mounted on the base plate 17 or the hump 18 - sliding plates 19, on which the control surfaces 15 are designed.

[0040] The inclination angles of the control surfaces 15 (i.e., the angle between a section of the control surface 15 and the press axis X) change along their course in the axial direction, so that flat sections 15F of the control surface 15 and steep sections 15S of the control surface 15 are formed.

[0041] The (angled) sliding plates 19 are attached to the base plate 17 and the hump 18 respectively by means of laterally arranged, angled fixing tabs 20 and screws 21. The humps 18 are fixed to the associated base plate 17 by means of centering pins and screws.

[0042] The press jaws 4 are supported on the support disc 7 by means of guide elements 24 (scroll blocks) which are interchangeably attached to the support disc 7 by means of two screws 22 and which cooperate with guide grooves 23 provided on the press jaws 4, and are guided radially displaceably on the support disc 7, wherein a friction-reducing bearing plate 25 is arranged between the end faces of the press jaws 4 and the support disc 7.

[0043] Radially on their outer sides, the press jaws 4 have sliding surfaces 27. These form mating surfaces with control surfaces 15 provided on the ring structure 3, which are inclined relative to the press axis X. These control surfaces interact with the sliding surfaces 27 in such a way that an axial displacement (arrow A) of the ring structure 3 towards the support disk 7 causes a radially inward movement (arrow B) of the press jaws 4. The press jaws 4 are designed such that their sliding surfaces 27 correspond to the control surfaces 15 of the control bodies 14, resulting in flat sections 27F and steep sections 27S on the sliding surfaces 27.

[0044] Over the entire possible range of motion (maximum range of motion / maximum displacement path) of the ring structure 3, the ratio of the axial movement of the ring structure 3 to the radial movement of the press jaws 4 changes, because the inclination angle of the control surfaces 15 changes along their course in the axial direction.

[0045] At the beginning and during the Fig. 1 and Fig. In the rapid traverse shown in 2A, the steep sections 15S of the control surfaces 15 of the control bodies 14 are in contact with the corresponding steep sections 27S of the sliding surfaces 27 of the press jaws 4, so that a relatively small axial displacement of the ring structure 3 causes a relatively large radial displacement of the press jaws 4.

[0046] During the Fig. 2B and Fig. In contrast, in the force path shown in 2C, the flat sections 15F of the control surfaces 15 of the control bodies 14 are in contact with the corresponding flat sections 27F of the sliding surfaces 27 of the press jaws 4, so that a relatively large axial displacement of the ring structure 3 only causes a relatively small, but all the more powerful, radial displacement of the press jaws 4.

[0047] To the extent set out above, the radial press corresponds to the well-known state of the art disclosed in the documents cited in the introduction, so that no further explanation is necessary.

[0048] The essential difference of the invention compared to the prior art becomes particularly apparent when comparing the control elements 14 of a radial press 1 according to the invention. Fig. 4A and Fig. 4B with previously known control bodies 28 of a radial press according to the state of the art according to Fig. 3 clearly: In the radial press 1 according to the invention Fig. 4A and Fig. 4B has a control surface 15 of the control body 14 in a projection plane V (perpendicular to the press axis X) two first steep sections A1S with a first (large) angle of inclination W1 and a second flat section A2F with a second (small) angle of inclination W2, wherein the first angle of inclination W1 is larger than the second angle of inclination W2.

[0049] The control surfaces 15 also have a third steep section A3S, which is arranged parallel to the two first sections A1S, and a fourth flat section A4F, which is arranged parallel to the second section A2F.

[0050] During the express run according to the Fig. 1 and Fig. 2A the steep sections (i.e. the third section A3S and the first sections A1S) of the control surfaces 15 are in contact with the corresponding sliding surfaces 27 of the press jaws 4.

[0051] During the power transmission according to the Fig. 2B and Fig. In 2C, however, the flat sections (i.e., the fourth section A4F and the second sections A2F) are in contact with the corresponding sliding surfaces 27 of the press jaws 4.

[0052] The second flat sections A2F each form a projection which is framed in the middle by two first steep sections A1S and protrudes forward (cf. Fig. 4A).

[0053] This design is not found in the prior art according to Fig. 3. This “forward displacement” of the flat sections of the control surface 15 according to the invention by means of the projection causes the radial forces to be transferred from the ring structure 3 to the press jaws 4 in an advantageous manner (especially immediately after the transition from rapid traverse to power traverse). Reference symbol list 1 radial press 2 cases 3 ring structure 4 pressing jaws 5 Press tool 6 Mantle section 7 Support disc 8 Housing locking ring 9 first piston ring chamber 10 first arrival 11 second piston ring space 12 second approach 13 Basic structure 14 Control bodies 15 Control area 15F flat section of a control surface 15S steep section of a control surface A1S first section of a control surface A2F second section of a control surface A3S third section of a control surface A4F fourth section of a control surface 17 Base plate 18 humps 19 sliding plates 20 fixing tabs 21 screws 22 screws 23 guide grooves 24 guide elements 25 bearing plates 27 sliding surfaces 27F flat section of a sliding surface 27S steep section of a sliding surface 28 previously known control bodies V Advanced Level W1 First tilt angle W2 Second tilt angle X Press axle

Claims

[1] Radial press (1) with a housing (2) having a shell section (6) and an end-face annular support disc (7), - a ring structure (3) slidably guided therein along a press axis (X) and several press jaws (4) arranged around the press axis (X), which are supported radially slidably on the support disc (7) and on which the ring structure (3) acts by means of control surfaces (15) inclined relative to the press axis (X), which bear against counter surfaces of the press jaws (4) designed as sliding surfaces (27), - wherein the inclination angle of the control surfaces (15) changes along their course in the axial direction such that, over the path of movement of the ring structure (3), its axial movement and the resulting radial movement of the press jaws (4) are in different ratios to each other, characterized by , that - in a projection plane (V) perpendicular to the press axis (X) the control surfaces (15) each have at least one first section (A1S) with a first angle of inclination (W1) and at least one second section (A2F) with a second angle of inclination (W2), wherein the first angle of inclination (W1) is greater than the second angle of inclination (W2). [2] Radial press (1) according to claim 1, characterized by , that the at least one first section (A1S) and the at least one second section (A2F) are each, at least section by section, designed as a planar ramp of the control surface (15). [3] Radial press (1) according to any one of the preceding claims, characterized by , that at least during individual operating positions of the ring structure (3) its control surfaces (15) and the sliding surfaces (27) of the press jaws (4) lie flat against each other. [4] Radial press (1) according to any one of the preceding claims, characterized by, that at least one second section (A2F) in the area of ​​the projection level (V) is designed as a projection. [5] Radial press (1) according to claim 4, characterized by , that at least one second section (A2F) in the area of ​​the projection level (V) is designed as a projection in the middle between two first sections (A1S). [6] Radial press (1) according to any one of the preceding claims, characterized by , that the control surfaces (15) each - have a third section (A3S) which is arranged parallel to the at least one first section (A1S), and - have a fourth section (A4F) that is arranged parallel to at least one second section (A2F). [7] Radial press (1) according to any of the preceding claims, characterized by, that the ring structure (3) has a base structure (13) and interchangeable control bodies (14) incorporated therein, wherein the control surfaces (15) are provided on the control bodies (14). [8] Radial press (1) according to any one of the preceding claims, characterized by , that the control surfaces (15) are provided on the surface of replaceable sliding plates (19). [9] Radial press (1) according to any of the preceding claims, characterized by , that the press jaws (4) have replaceable sliding plates (19) on which the sliding surfaces (27) are provided. [10] Radial press (1) according to any one of the preceding claims, characterized by , that in planes perpendicular to the press axis (X) the control surfaces (15) each lie on a polygon with corners arranged between two adjacent press jaws (4).

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