Radial press

Abstract

Radial press comprising a base, a hollow ring die supported in a rotatable manner relative to a pressing axis on the base, the ring die having an inner contour tapering in the direction of the pressing axis and being rotationally symmetrical relative to the pressing axis, a rolling body unit rotatable relative to the pressing axis, the rolling body unit having a thrust ring surrounding the pressing axis and a plurality of rolling bodies arranged around the pressing axis and being rotationally symmetrical at least locally tapering. The rolling bodies are supported in a rotatable manner on the thrust ring relative to the pressing axis at a variable spacing and are able to roll on the inner contour of the ring die. A rotational drive for rotating the ring die and / or the rolling body unit about the pressing axis acts on the ring die and / or the rolling body unit. Furthermore, a feed drive for causing an axial adjustment of the rolling body unit and the ring die relative to one another along the pressing axis acts on the rolling body unit and / or the ring die.

Description

Technical Field

[0001] The present invention relates to a radial press, that is, a press for radially deforming a workpiece relative to a pressing shaft while reducing the radial dimension of the workpiece. Background Technology

[0002] A typical workpiece radially formed using this type of radial press is a connecting fitting mounted on the hose section at the end of a hydraulic hose line. Here, a sleeve surrounding the hose is pressed radially inward against a "nipple" inserted into the hose, thereby clamping the hose between the nipple and the sleeve and securing the hose to prevent it from being pulled out of the fitting. Other typical components joined by radial pressing include armature elements and high-current insulators. Other practical applications of the radial press type mentioned here involve radial forming of workpieces performed outside of the joining process.

[0003] Different concepts and various technical solutions for radial presses applicable to the above-mentioned types of radial pressing are known. See for example DE 20 2016 100 660 U1, DE 20 2016 008 097 U1, DE 10 2016 106 650 A1, DE 102014 014 585 B3, DE 10 2014 012 485 B3, DE 10 2014 008 613 A1, DE 10 2011 015770 A1, DE 10 2011 015 654 A1, DE 10 2009 057 726 A1, DE 10 2005 041 487 A1, DE10 2005 034 260 B3, DE 601 21 915 T2, DE 298 24 688 U1, DE 199 44 141 C1, DE 19940 744 B4, DE 101 49 924 A1, DE 41 35 465 A1, and DE 35 13 129 A1. Regardless of their individual structures and other technical features, the common feature of known radial presses is that multiple pressing bodies (most commonly eight pressing bodies) arranged uniformly around the pressing axis, with a generally wedge-shaped cross-section, are moved uniformly (and usually simultaneously) radially toward the pressing axis by means of a (usually hydraulic) actuator. In this case, the pressing bodies have a pressing surface (e.g., concave, implemented as a cylinder) on their radially inner side, which contacts the workpiece during forming; the geometry of the pressing surface corresponds substantially regularly to a segment (e.g., one-eighth) of the target geometry of the formed workpiece. In this regard, it should be noted that the radial press mentioned herein is suitable for radial forming of workpieces of different geometries, from (idealized) cylindrical workpieces to other strictly rotationally symmetric workpieces (i.e., workpieces with circular cross-sections having different radii perpendicular to the workpiece axis) and even workpieces with non-circular (e.g., polygonal) cross-sections.

[0004] A pressing device according to another technical concept is known from DE 295 00 338 Ul for radially pressing a pressing fitting onto a tube end. This pressing device includes a split-type pressure ring that can be closed around the pressing fitting, having pressing elements distributed on its inner circumference that are radially inwardly movable by means of a feed device and implemented as rotatable pressure rollers. A pressing device according to DE 200 23 234 Ul is based on a similar functional and structural principle. According to EP 0 916 426 B1, this concept is implemented to form end parts of workpieces (e.g., metal shells) that are otherwise cylindrical, wherein the end part is eccentric with respect to the cylindrical region of the workpiece and has a reduced diameter. Summary of the Invention

[0005] The applicant's known radial press implemented according to the aforementioned prior art (see also www.uniflex.de) has proven highly advantageous in practice. These radial presses can reliably and reproducibly perform radial pressing to meet the highest requirements. However, in certain applications, radial presses are preferable for achieving molding tasks similar to those achieved with conventional radial presses according to the prior art, but using a lower-power drive unit. One reason is the need for radial pressing in a clean air chamber. For this purpose, radial presses with purely electric press drives are more suitable than those with electro-hydraulic press drives, although purely electric drives cannot match the high power density of electro-hydraulic drives.

[0006] The solution of the present invention to achieve the above-mentioned objective lies in the provided radial press. Therefore, the radial press according to the invention is characterized by comprising a base, a hollow ring die having an inner contour tapering towards the press axis and rotationally symmetrical relative to the press axis, supported on the base in a manner rotatable relative to a press axis, and a rolling element unit rotatable relative to the press axis, the rolling element unit having a thrust ring surrounding the press axis and a plurality of rolling elements arranged around the press axis and at least partially tapering and rotationally symmetrical, the rolling element unit being axially supported on the thrust ring in a manner rotatable relative to the press axis by means of variable spacing and capable of rolling on the inner contour of the ring die, wherein a rotary actuator acts on the ring die and / or the rolling element unit, the rotary actuator causing the ring die and / or the rolling element unit to rotate about the press axis, and further wherein a feed actuator acts on the rolling element unit and / or the ring die, the feed actuator causing the rolling element unit and the ring die to axially adjust relative to each other along the press axis. Within the range of reducing the pressing size (which refers to the radial dimension of the workpiece produced by radial forming, especially the workpiece diameter), the rolling element feed is achieved by axially adjusting the rolling element unit relative to the ring die using a feed driver.

[0007] Thus, this invention completely departs from the concept followed by all established radial presses, which (see above) are characterized by radially moving pressing bodies that, during radial forming, abut against the workpiece with (typically concave) pressing surfaces; in this case, there is usually a relatively static contact between the pressing bodies and the workpiece. Alternatively, according to the invention, radial forming is performed by rolling bodies that roll on the surface of the workpiece and on the inner contour of a ring die, wherein, in order to gradually reduce the pressing size, the radial feed of the rolling body is achieved by axial displacement of the rolling body units relative to the ring die, the inner contour of which tapers along the pressing axis. Instead of the conventional pressing bodies abutting against the workpiece with their concave pressing surfaces over a relatively large area, in the radial press according to the invention, the rolling bodies that form the workpiece, at least partially tapering, contact the workpiece only with a relatively small surface (typically close to line contact), in which case the orientation of the tapering portion of the rolling body is the same relative to the pressing axis as the orientation of the tapering portion of the inner contour of the ring die. In this case, as will be shown in further detail below, the geometry of the contact surface can be influenced, particularly by the geometry of the rolling elements, thereby achieving a rectangular contact surface, but also, for example, a trapezoidal contact surface. Unlike conventional radial presses (see above), the contact surface of the rolling elements "wanders" on the surface of the workpiece; therefore, in the implementation of the invention, radial pressing is not performed in discrete planes (e.g., four planes in the case of an 8-jaw radial press), but rather in a circumferential radial forming. This allows the pressure required for workpiece forming to be provided with a significantly reduced force compared to using a conventional radial press. This, in turn, allows the use of a radial press drive with significantly reduced efficiency compared to using a conventional radial press to complete the predetermined radial press task. Thus, for example, various typical radial pressing forming can be performed using the radial press according to the invention, wherein the rotary drive that rotates the ring die and / or rolling element units about the pressing axis and the feed drive that causes the rolling element units and the ring die to axially adjust relative to each other along the pressing axis are implemented as relatively compact pure electric drives. At least in the case of directly using electric drives, improved efficiency and very good energy efficiency can be achieved because the energy conversion from mechanical energy to hydraulic energy is eliminated, and thus the associated conversion losses are also eliminated.

[0008] In certain cases, another important advantage of the present invention is that it allows for radial forming of workpieces such that they are ideally strictly rotationally symmetric at the end of the radial forming process. This is achieved by having an ideal circular cross-section when using an ideal cylindrical geometry (or, when using another strictly rotationally symmetric geometry, having a different ideal circular cross-section). This is typically impossible to achieve with conventional radial presses because, during the pressing process, connecting plates are formed between two adjacent pressed bodies (through the outwardly extruded material), and even more or less noticeable "tunnels" can form beneath these connecting plates. In extreme cases, this non-uniformity can even cause cracking or other damage. In this respect, the radial press according to the present invention also proves superior to the prior art.

[0009] It should be noted that, in applications of the radial press according to the invention, the radial forming of the workpiece can also be limited to axially spaced regions on the workpiece surface. In this case, the rolling elements do not roll over the entire periphery of the workpiece, but (oscillatingly) only over certain regions. Therefore, if the feed of these rolling elements increases and decreases rhythmically during the rolling process due to the corresponding rhythmic relative axial movement between the ring die and the rolling element units, the radial press according to the invention can be specifically used to manufacture non-circular workpieces.

[0010] In this context, the description indicates that the tapering geometry of the rolling element does not necessarily extend over its entire axial length; according to the description, the rolling element is at least partially tapered. Specifically, the rolling element may, for example, be cylindrical over a portion of its axial length, or even extended as appropriate, as is the case for rolling elements with (symmetrical or asymmetrical) crown or barrel geometries. Importantly, the rolling element makes rolling contact with the inner contour of the ring die, which tapers in the same direction, precisely in the tapering region. Furthermore, as can be seen from the above, within the scope of the invention, the inner contour of the ring die does not necessarily taper over its entire axial extension; precisely, tapering over a portion of the axial length is sufficient, where this tapering region can be used for rolling contact with the rolling element. Therefore, the description according to this application refers to the ring die being designed at least partially precisely in such a way that the ring die has an inner contour that tapers towards the pressing axis and is rotationally symmetrical with respect to the pressing axis.

[0011] To avoid misunderstanding, it should be noted upfront that the descriptive information that the rolling elements “roll” on the inner contour of the ring die—in terms of perfect rolling—does not imply the absence of relative motion between the surfaces of the rolling elements and the ring die relative to each other in the contact area between the respective rolling elements and the inner contour of the ring die. More precisely, such relative motion can be achieved, at least locally and constrainedly (circumferentially) (see below). Furthermore, again to avoid misunderstanding, it should be noted that a rotary actuator (as an alternative or supplement to the rotary actuator of the thrust ring) acting on the rolling element unit and causing it to rotate about the pressing axis can also be implemented as an actuator that primarily rotates the individual rolling elements (or at least a portion thereof), wherein these rolling elements roll on the workpiece due to the inherent rotation thus applied thereto. If the workpiece is held in a rotationally fixed manner, as is applicable to various typical radial press applications, the thrust ring and ring die of the rolling element unit rotate relative to the pressing axis by the rolling elements rolling on the workpiece and on the inner contour of the ring die. However, if the rotation of the workpiece is taken into account, depending on the specific technical solution of the radial press, the thrust ring or ring die of the rolling element unit can be rotationally fixed.

[0012] It should also be clearly stated beforehand that workpieces with localized contractions or similar surface depressions can be manufactured using a radial press according to the invention. For this purpose, the rolling elements can be implemented and / or shaped in a correspondingly shorter manner in the direction of their axis, or have a non-tapering geometry. The surface structure of the workpiece can also be shown through the corresponding structure of the rolling elements; in this regard, the rolling elements can, for example, have smaller surface depressions, thereby forming corresponding surface protrusions (e.g., spherical protrusions) on the workpiece.

[0013] According to a first preferred improvement of the invention, the rolling element and the inner contour of the ring die have a substantially frustoconical basic shape, where "substantially" indicates that the important aspect is not a mathematically precise frustoconical geometry. Therefore, within the scope of this improvement, for example, rolling elements that approximate a frustoconical shape but have slightly convex or constricted surfaces can also be used, and in some cases, these rolling elements are even very advantageous. According to this exemplary advantageous embodiment of the rolling element's "substantially frustoconical basic shape," the "cone angle" of the rolling element varies continuously within its extension along its own axis. Particularly preferably in this case, the double cone angle of the rolling element having a substantially frustoconical basic shape is substantially equivalent to half the cone angle of the ring die. This structure of the radial press is particularly suitable for pressing workpieces with fully or at least substantially cylindrical surfaces, where the size of the radial press can be relatively small. Furthermore, rolling elements with a basic frustoconical shape also include those that are strictly frustoconical in the extended portion of their length, but deviate from the aforementioned shape in the lower region (e.g., adjacent to one or both ends) (e.g., circular, cylindrical, chamfered, or similar shapes). The above-described approach applies if the rolling element is not shaped at the ends in a manner deviating from the frustoconical shape, but rather at any position between the two ends; in this case, the rolling element may, for example, have at least one circumferential groove, thereby forming at least one corresponding circumferential rib on the workpiece during the radial forming process. Therefore, within the range of the basically frustoconical basic shape of the rolling element and the inner contour of the ring die, various technical solutions with different details can be employed, which have proven advantageous for different applications of radial presses.

[0014] Therefore, according to the first particularly preferred technical solution, the inner contour of the ring die and the rolling element can be geometrically precisely truncated conical. This results in a precise and well-defined position of the rolling element, thereby achieving particularly high repeatability of the forming process. However, depending on the specific geometric proportions, relative movement of the rolling element with respect to the workpiece and the ring die surfaces (more or less noticeable) is unavoidable; pure rolling motion of the rolling element on the workpiece surface and the inner surface of the ring die cannot be achieved.

[0015] To reduce the associated "scratching" and its adverse effects, in cases where the inner contour of the ring die is, where the configuration is geometrically precise, a truncated cone shape, the rolling element can be slightly crown-shaped according to another particularly preferred technical solution. This results in a non-uniform contact pressure between the rolling element and the workpiece and the ring die across its axial extension; specifically, the contact pressure has a maximum value at approximately half the length of the rolling element and decreases towards its two end faces. This has proven particularly advantageous with this configuration, where, as the pressing diameter gradually decreases, the workpiece moves axially (as needed, forward and backward) relative to the rolling element during forming, causing the instantaneous forming area to "wander" on the workpiece (as needed, forward and backward) to gradually cover the entire forming area of ​​the workpiece. Here, the slightly crown-shaped embodiment of the rolling element accommodates the relative axial movement of the rolling element and the workpiece relative to each other. However, in this configuration, where the rolling elements detect the entire forming area of ​​the workpiece, and the workpiece and rolling element units do not undergo such axial movement relative to each other, a slightly crown-shaped implementation of the rolling elements is also advantageous, i.e., to generate a stress distribution in the workpiece by means of the decreasing stress at the edge of the groove-forming area, which has a positive impact on the service life of the workpiece. Alternatively, the shape of the contact surface between the rolling elements and the workpiece can be influenced by the geometry of the rolling elements (combined with the geometry of the workpiece to be formed): to avoid localized load peaks, a substantially rectangular contact surface is set.

[0016] According to another particularly preferred technical solution, the aforementioned "scratching" or its potential adverse effects can also be reduced by the following method: In cases where the rolling elements are, in some cases, geometrically precise truncated conical embodiments, the inner surface of the ring die is slightly curved at the waist, i.e., slightly constricted inward toward the axis compared to a precise conical surface. This also causes an uneven distribution of contact pressure on the rolling elements (within their axial extension) of the ring die. In this case, in order to axially adjust the rolling element unit relative to the ring die, the feed of the rolling element in the radial direction manifests as a more or less significant change in the angle of attack of the rolling element axis relative to the pressing axis (specifically depending on the degree of curvature of the inner surface of the ring die), and thus manifests as a change in the geometry of the forming area defined by the entire rolling element (e.g., by transitioning from a slightly conical shape to a cylindrical shape). This can be used to specifically influence the radial pressing process, for example, by specifically and gradually moving the instantaneous area of ​​workpiece forming during full radial pressing.

[0017] Regarding the ring die, it can be implemented as a single piece. However, a particularly preferred embodiment of the invention is characterized by a multi-component implementation of the ring die, namely, the ring die comprising a support ring and an insert replaceably housed within the support ring and defining an inner contour. Several particularly practical advantages can be achieved with this embodiment. Thus, in the event of wear (see the “scratching” that may occur with rolling elements discussed above), the radial press can be repaired or refurbished with minimal material and time. This advantage can already be achieved through a replaceable (e.g., more or less funnel-shaped) sliding bearing plate implemented as a deep-drawn piece, in which case an embodiment of the ring die having grooved, drilled, etc. (see below) inner surfaces can be shown particularly simply.

[0018] Furthermore, regarding the applicable multi-part structure of the ring die, the radial press can be adapted to different pressing tasks (e.g., different starting diameters and / or end diameters of the workpiece) with minimal cost by replacing the insert with another insert having a different internal geometry, so that the rolling elements can provide a complete radial feed through the axial mobility of the ring die and the rolling element unit relative to each other for effective radial forming of the workpiece.

[0019] Any device for holding the workpiece during radial pressing can be advantageously mounted on the base of the radial press. If the rolling elements must move axially on the workpiece (as many times as appropriate) during radial pressing (see above), the holding device allows the held workpiece to move axially relative to the base within a predetermined range. For this purpose, two (possibly adjustable) stops can be advantageously provided.

[0020] According to another preferred improvement of the invention, the rolling element is rotatably supported on a bearing member, which is guided on a thrust ring (preferably in an undercut guide of the thrust ring) in a manner movable on a sliding surface. In this case, the aforementioned sliding surface is particularly preferably provided on the surface of a replaceable sliding bearing plate. This ensures a uniform, low-friction feed of the rolling element with minimal cost by replacing the sliding bearing plate, which is reflected in the optimal operating performance of the radial press, i.e., achieving high-quality radial pressing while achieving good repeatability of radial forming. These sliding surfaces can extend perpendicular to the pressing axis, and these sliding surfaces can be flat, but can also be more or less curved. However, it is particularly advantageous that these sliding surfaces are inclined to the pressing axis, i.e., in the opposite direction to the taper of the inner contour of the ring die, but ideally steeper than the latter. Thus, with the semi-cone angle of the substantially frustoconical inner contour of the ring die, for example, between 10° and 20°, the angle of attack of these sliding surfaces relative to the pressing axis can be between 80° and 85°. Within the scope of the present invention's particularly low-friction feed technique with rolling elements, hydrodynamic support of the bearing elements on the thrust ring can also be employed. This "wet" support of the bearing elements on a pressure fluid pad is particularly considered if the workpiece is also subjected to "wet" radial forming, i.e., radial pressing with liquid applied (lubricating and / or cooling) to the forming zone.

[0021] In particular, it has proven advantageous, according to another preferred improvement of the invention, that the thrust ring is part of a rolling element cage having walls including notches in which the rolling elements are rotatably supported on their two end faces. For feeding the rolling elements, each of the two end face pivot bearing structures here includes a bearing element guided in a corresponding guide within the rolling element cage in a manner movable on the sliding surface.

[0022] Another preferred improvement of the invention is characterized in that the base is implemented in a shell-like manner, wherein the outer sleeve section of the base at least partially surrounds the ring die. In this case, the shell-like base provides protection for the rotating components of the radial press, as well as minimizing the risk of operator injury. Ideally, the shell-like base (where appropriate, by means of a top cover or similar component) is as enclosed as possible or completely, such that all rotating components are completely surrounded or at least covered. Components of the radial press protruding from the shell-like base (e.g., particularly components of the feed drive) are ideally rotationally fixed / anti-rotational. Thus, according to a preferred embodiment, the feed drive may comprise a pressure tube coaxial with the pressing shaft, which acts on a thrust ring via an axial bearing and is guided on the base in a manner movable along the pressing shaft by a rotationally fixed linear guide. Where appropriate, the workpiece may be introduced through the pressure tube into a machining chamber located between these rolling elements. According to a preferred improvement of the invention, an alternative or supplementary method for entering the machining chamber to load the workpiece is that the base has a notch extending around the pressing shaft adjacent to the end face of the ring die corresponding to the smaller diameter of the inner contour. In certain cases, even from the perspective of the quality of the formed product, it is particularly advantageous to load the workpiece through the opening into the processing chamber. If the radial press is part of an automated production line, the accessibility of both sides of the processing chamber may have a particularly significant advantage; because from a process efficiency perspective, the workpiece handling flow of loading tools from one side of the radial press and removing workpieces from the other side is very advantageous.

[0023] According to another preferred improvement of the invention, an odd number of rolling elements are provided, such that two rolling elements are not diametrically opposed to each other. This has proven to be very advantageous in terms of the quality of radial pressing, as it significantly reduces the risk of undefined operating and load conditions. In the same context, it is advantageous that the rolling element unit has preload springs that preload these rolling elements outward to press them against the ring die. For typical applications, it has proven very advantageous to use three, five, or seven rolling elements, with five rolling elements being preferred; and the average (outer) diameter of these rolling elements is preferably between 15% and 30% of the average (inner) diameter of the ring die, particularly preferably between 20% and 25%.

[0024] For various applications, it is advantageous that the surface of the rolling element is more or less ideally smooth, for example, polished. However, this is not always applicable. Specifically, another preferred improvement of the invention is characterized by the surface of the rolling element being shaped. Thus, for the radial forming of workpieces made of a particular material, it is advantageous for the rolling element to have a spherical protrusion-like shape, which ensures that the pressing force is more or less concentrated in a specific location, where flatness is achieved by rolling repeatedly over the surface of the workpiece. In some cases, other shapes may also have a positive effect. For the simplified feed of the rolling element during radial forming, a helical shape of the rolling element has proven advantageous. Axial thrust forces on the workpiece can also be reduced by specifically roughening the surface of the rolling element. Circularly closed micro-tooth extensions within the respective circumference of the relevant rolling element facilitate a press-fit between the rolling element and the ring die and thereby (in the case of a rotary actuator acting on the ring die) prevent the rolling element from locking.

[0025] Regarding the surface of the inner contour of the ring die, an embodiment that is at least close to ideal smoothness (e.g., polished) is advantageous for various conventional applications. However, slightly deviated technical solutions may also prove advantageous in this regard. A particularly preferred improvement in this respect is characterized by the inner contour of the ring die being slotted, specifically in that the inner contour has one or at least one spiral groove. In this case, abrasive debris, contaminants, etc., can be removed from the running area of ​​the rolling element along the groove without affecting the smooth operation of the rolling element, wherein the relevant groove can also be connected to a suction device for this purpose. Removal of abrasive debris, contaminants, etc., not only improves the dimensional accuracy and other production quality of the workpiece, but also has a positive impact on the service life of the radial press. In the above-mentioned aspect, according to another alternative preferred embodiment of the invention, perforation in the inner contour of the ring die may also prove advantageous, wherein the relevant holes are also particularly preferably connected to a suction device. This can be implemented particularly effectively in radial presses, wherein the ring die (as described above) is composed of multiple parts, including a support ring and an insert removably housed in the support ring and defining the inner contour. The insert can be "ventilated from behind" via a suitable annular cavity between the support ring and the insert. A drilled hole in the insert connects to the associated annular cavity to remove abrasive debris or contaminants. Even introducing localized recesses (similar pits) into the surface of the inner contour of the ring die is advantageous, as contaminants will accumulate there; these can then be removed through regular cleaning.

[0026] Within the scope of this invention, several variations can be considered for implementing a rotary actuator that causes rolling elements to roll on a non-rotating workpiece. Structurally, it has proven advantageous for the rotary actuator to act only on the ring die. In this case (similar to the case in a planetary gear transmission), the rolling element units are driven together at a correspondingly reduced rotational speed. However, the rotary actuator can also act only on the rolling element units (i.e., the thrust ring and / or rolling elements), in which case (again similar to the case in a planetary gear transmission), the ring die is driven together at a correspondingly increased rotational speed. Furthermore, it is also possible to consider having the rotary actuator act on both the rolling element units and the ring die simultaneously. In this case, the possible rotation of the workpiece can also be affected by influencing the rotational direction and speed of these two components with the aid of appropriate control devices. While this is an exception in typical applications, it is advantageous in certain cases. If the rotary actuator acts only on, or at least also on, the ring die, it is particularly advantageous from a static and manufacturing precision perspective that the bearing structure of the ring die on the base comprises two spatially separated bearing units, with the point of action of the rotary actuator on the ring die located between the two bearing units.

[0027] Regarding the implementation of the feed driver, several variations can be considered within the scope of this invention. Structurally, it has proven advantageous that the feed driver acts only on the rolling element unit, wherein the ring die is axially fixed relative to the base. However, in certain cases, it may also prove advantageous that the feed driver acts only on the reverse rotation of the ring die, wherein in this case, the rolling element unit is axially fixed relative to the base. Finally, a technical solution can also be adopted in which both the rolling element unit and the ring die are axially movable relative to the base, wherein the feed driver acts on both the rolling element unit and the ring die simultaneously.

[0028] According to an improvement of the invention described above, a rolling element that is substantially cylindrical or at least partially extended can be used instead of a rolling element that is at least partially tapered. A radial press thus implemented is suitable for manufacturing radially shaped workpieces that should not acquire a cylindrical geometry in the radially shaped region, but rather, more precisely, a tapered geometry. This will also be explained in the accompanying drawings (see [reference to...]). Figure 4 and Figure 5 The following is a detailed description of the invention. This point also applies to another improvement of the invention described above, specifically: the ring mold is not rotating, but is fixed relative to the base. Compared to the basic concept described above, the various preferred technical solutions detailed in this application have proven advantageous for both improvements of the invention.

[0029] In a further improved form, the basic concept of the invention, which has similar advantages and is based within the scope set forth above, can be improved in the following manner (see [reference]). Figure 5 The inner contour of the ring die, tapering towards the pressing axis, is not rotationally symmetric, but has multiple bag-shaped accommodating portions for rolling elements. These accommodating portions are evenly arranged around and inclined to the pressing axis. The rolling elements do not roll on the inner contour of the ring die, but are slidably supported in the accommodating portions in a manner that allows them to rotate about their own axes and move along the axes of the relevant bag-shaped accommodating portions. Here, fluid support has proven advantageous. In this case, these bag-shaped accommodating portions can in particular have partially cylindrical surfaces, with their cylindrical axes inclined to the pressing axis. In this case, these cylindrical axes intersect each other at a common intersection point on the pressing axis. In this case, these rolling elements can also be implemented in a manner that is at least partially tapered. However, this is not mandatory. These rolling elements can also be cylindrical, for example, if the workpiece in the radial forming zone should not have a cylindrical geometry but rather a conical geometry, which is particularly advantageous. Compared with the basic concept further elaborated above, the various preferred technical solutions given in detailed description for improved embodiments of the invention have proven advantageous. Independently and explicitly, the aforementioned related implementations of the present invention can be defined as a radial press, which includes... - Base - A hollow ring die supported on the base in a manner rotatable relative to the pressing shaft, the ring die having an inner contour tapering towards the pressing shaft and implemented in a non-rotationally symmetrical manner, the inner contour having a plurality of pouch-like accommodating portions for rolling elements, the accommodating portions being evenly arranged around the pressing shaft and inclined to the pressing shaft, and - A rolling element unit rotatable relative to the pressing shaft, the rolling element unit having a thrust ring surrounding the pressing shaft and a plurality of rolling elements arranged around the pressing shaft and, where appropriate, tapering in a manner at least partially, the rolling elements being axially supported on the thrust ring by means of variable spacing in a rotatable manner relative to the pressing shaft and slidably supported in the receiving portion in a manner rotatable about their own axes and movable along the axis of the associated bag-shaped receiving portion. A rotary driver that rotates the ring die and / or the rolling element unit about the pressing shaft acts on the ring die and / or the rolling element unit. In addition, a feed driver that causes the rolling element unit and the ring die to adjust axially relative to each other along the pressing shaft acts on the rolling element unit and / or the ring die. Attached Figure Description

[0030] The present invention will now be described in detail with reference to several embodiments shown in the accompanying drawings. Figure 1 This is an axial cross-sectional perspective view of the first radial press according to the present invention. Figure 2 A partial view of a radial press according to a second embodiment of the present invention; Figure 3 This is an improved implementation of the present invention. Figure 4 This is an improved version of another implementation of the present invention. Figure 5 This is an improved form of another implementation of the present invention. Figure 6 This is yet another preferred embodiment of the present invention. Figure 7 In another embodiment of the present invention, Figure 8 for Figure 7 An enlarged view of a portion of the radial press shown. Figure 8a for Figure 8 Detailed cross-sectional view. Detailed Implementation

[0031] Figure 1 The diagram shows a radial press for radially forming a workpiece W (exemplarily shown via ring 1). It comprises a base 2, implemented as a housing, having a bottom 3, an outer sleeve section 4, and a top cover 5. A hollow ring die 8, rotatable relative to the pressing axis X, is supported on the base 2 by means of a first rolling bearing 6 and a second rolling bearing 7. Rolling element units 9, rotatable relative to the pressing axis X, are also present as main components. In this case, the ring die 8 has a frustoconical (half-cone angle approximately 15°) geometry with a tapered inner contour 10 that tapers in the direction of the pressing axis X and is rotationally symmetrical relative to the pressing axis X. The rolling element units 9 include a thrust ring 11 surrounding the pressing axis X and five frustoconical rolling elements 12 (rolling cones 13 with double cone angles approximately 15°) arranged around the pressing axis X, which can roll on the inner contour 10 of the ring die 8.

[0032] In this configuration, the rolling cone 13 is rotatably supported on the thrust ring 11, meaning its distance from the pressing shaft X is variable. For this purpose, each rolling cone 13 is rotatably supported on a bearing member 15 by means of a corresponding bearing 14, which is guided on the thrust ring 11 in a manner movable on a sliding surface 16. In this configuration, a sliding surface 16, located at the bottom of the guide member 17 that laterally surrounds the bearing member 15 and inclined towards the pressing shaft X, is implemented on the surface of a replaceable U-shaped sliding bearing plate 18.

[0033] A feed driver acts on the rolling element unit 9, causing axial adjustment of the rolling element unit along the pressing shaft X. The feed driver includes a pressure tube 19 coaxial with the pressing shaft X, a thrust ring 11 supported on the pressure tube by a tapered roller bearing 20, and the pressure tube is guided on the top cover 5 of the base 2 by a linear guide 21 in a manner movable (but rotationally fixed) along the pressing shaft X. A linear actuator (not shown, for example, implemented as a flange-mounted electric spindle drive on the top cover 5 of the base 2) acts on the pressure tube 19.

[0034] A rotary actuator acts on the ring die 8, causing it to rotate about the pressing shaft X. The rotary actuator includes a rotary actuator (not shown, for example, implemented as a flange-mounted motor on the outer sleeve section 4 of the base 2) and a drive belt 22 coupling the rotary actuator to the ring die 8, wherein the outer sleeve section 4 of the base 2 has a notch (not shown) for the drive belt 22. In this case, the drive belt 22 surrounds the ring die 8 between a first rolling bearing 6 and a second rolling bearing 7, the first rolling bearing forming radial support for the ring die 8 and implemented as a ball bearing 23, and the second rolling bearing forming axial / radial support for the ring die 8 and implemented as a tapered roller bearing 24. In this case, the inner ring 25 of the second rolling bearing 7 is arranged on an annular protrusion 27 on the bottom 3 of the base 2, which surrounds the central notch 26 of the base 2 extending about the pressing shaft X.

[0035] Figure 2 Within the relevant local scope, the rolling element unit 9 is shown relative to... Figure 1 An improved implementation is described below. Here, the thrust ring 11 is part of the rolling element cage 28, which has an annular wall 29 with a number of notches 30 corresponding to the number of rolling elements 12. In each of these notches 30, the rolling element 12 is rotatably supported on its two end faces. For this purpose, the rolling element 12, which is generally frustoconical, has a journal 31 at its end face, which engages in the inner ring of the tapered roller bearing 32, the outer ring of which is housed in the bearing housing 33. A replaceable cylindrical sliding bearing plate 34 is placed on the bearing housing, and the sliding bearing plate slides on the sliding surface 16 that defines the corresponding notch 30 of the rolling element cage 28. In this case, the cup-shaped cylindrical sliding bearing plate 34 is sized to match the notch 30 so as to achieve lateral, i.e., circumferential, displacement along the sliding surface 16 in the direction of the pressing axis X, away from the pressing axis.

[0036] according to Figure 2 All further aspects of the embodiments can be derived by those skilled in the art from the above description. Figure 1 As described in the first embodiment shown, therefore, to avoid repetition, please refer to the above description of... Figure 1The first embodiment shown is described below. It should be emphasized that... Figure 2 and Figure 1 It can be clearly shown that although the forces acting on the rolling cones are balanced, the surface pressure in the corresponding contact area of ​​the rolling cones 13, which are relatively close to the (concave) inner contour 10 of the ring die 8, is significantly lower than the surface pressure in the corresponding contact area of ​​the rolling cones 13 on the (convex) outer contour of the workpiece W. In other words, the geometric proportions of the workpiece W generate a correspondingly increased radial pressure relative to the pressure between the ring die 8 and the rolling cones 13, thereby achieving a correspondingly higher forming effect. In this case, similar to the contact area of ​​the rolling cones 13 on the ring die 8, the contact area of ​​the rolling cones 13 on the workpiece W also typically tapers slightly towards the tip of the rolling cones 13, a point that can be used to increase pressure in that direction if necessary.

[0037] according to Figure 3 In relation to the present invention Figure 1 and Figure 2 In the improved embodiment shown, the rotary actuator acts not on the ring die 8.1, but on the rolling element unit 9.1. In this regard, the drive belt 22 is wound around a sleeve 35 formed on the thrust ring 11.1 of the rolling element unit 9.1, which also serves to support the rolling element unit 9.1 in a rotatable manner relative to the pressing shaft X via two rolling bearings 36. Conversely, in relation to the present invention... Figure 1 and Figure 2 In the improved embodiment shown, the feed driver acts not on the rolling element unit 9.1, but on the ring die 8.1. In an exemplary embodiment, the feed driver is hydraulically implemented, specifically, an annular flange 37 disposed on the outer periphery of the ring die 8.1 is guided in a cylindrical bore 38 of the base 2.1 and divided into two opposing hydraulic working chambers 40, which can be supplied by a fluid connector 39. In this respect, the ring die 8.1 is not designed to rotate about the pressing axis X, thereby causing the workpiece W to rotate due to the action of the rolling elements 12.1 rolling on the inner contour 10.1 of the workpiece and the ring die 8.1. However, it is obvious that rotation of the ring die 8.1 about the pressing axis X is easily achieved to avoid rotation of the workpiece W, specifically in (see...) Figure 5 The ring die 8.1 is rotatably housed in a bearing sleeve, which is in turn housed in a base 2.1 along the pressing axis X in a manner adjustable by means of a feed driver.

[0038] according to Figure 3 All further aspects of the radial press can be derived by those skilled in the art from the above description. Figure 1 and Figure 2As can be seen from the description of the illustrated embodiments, therefore, to avoid repetition, please refer to the above description of... Figure 1 and Figure 2 Description of the illustrated embodiment.

[0039] Figure 4 The improvement scheme shown is the same as Figure 3 The difference in the illustrated improvement is essentially only in the shape of the rolling element 12.2. Because the rolling element is cylindrical in this case, the radially deformed workpiece W does not have a cylindrical shape in the forming zone, but rather a tapered shape corresponding to the tapered inner contour of the ring die 8.2. Furthermore, particularly regarding other aspects of the rolling element unit 9.2, together with the thrust ring 11.2 and the base 2.2, refer to the above-described improvements... Figure 1-3 Explanation.

[0040] Figure 5 The improvement scheme shown is based on the following concept. Figure 4 The improved design is shown. The key difference relates to the ring die 8.3, specifically as follows: the inner contour 10.3 of the ring die 8.3 is not rotationally symmetrical; rather, it has bag-shaped receiving portions 41 for the rolling elements 12.3, which are evenly arranged around the pressing axis X and inclined relative to the pressing axis X. Therefore, the cylindrical rolling elements 12.3 do not roll on the inner contour 10.3 of the ring die 8.3, but rotate about their own axis in the corresponding receiving portions 41, for which the inner surface of the receiving portion is relative to the cylindrical segment that partially surrounds the corresponding rolling element 12.3. The ring die 8.3 is rotatably housed in a bearing sleeve 43 by two rolling bearings 42, which in turn are housed in a base 2.3 in a manner movable along the pressing axis X. The feed actuator is also exemplarily implemented hydraulically, specifically in that an annular flange 44 disposed on the outer periphery of the bearing sleeve 43 is guided in a sealed manner within a cylindrical bore 45 of the base 2.3 and divided into two opposing hydraulic working chambers 47, which can be supplied via a fluid connector 46. However, it is obvious that it can also be implemented as in accordance with Figure 3 and Figure 4 As shown in the radial press, electric feed drive (e.g., via an electric spindle drive) can be easily implemented. In this radial press, the rolling element unit 9.3 and the ring die 8.3 rotate about the pressing axis X in the same direction of rotation and at the same speed, provided, of course, that the workpiece W is held in a support that prevents it from rotating about the pressing axis X.

[0041] according to Figure 6 and Figure 7Both improved embodiments can be derived by those skilled in the art from the above detailed description of other embodiments, in which the workpiece to be formed is typically fixed in a position and rotationally fixed relative to the (also housing-type) base 2. Unnecessary repetition regarding the operation of the radial press and the function of the various components is omitted. However, particular attention should be paid to the rotatable, radially and axially neutralized support on the hollow journal 48 mounted on the lower top cover 5 of the base 2, which allows the rolling element unit 9, which can be rotated about the pressing shaft X by means of a belt drive (see belt 22) via a motor M. Figure 2 As illustrated, a portion of the rolling element unit 9 is a rolling element cage 28 with notches. Within these notches, two bearing members 49 are supported on corresponding sliding guides in a manner movable toward and away from the pressing shaft X, and corresponding rolling cones 13 are supported on these two bearing members in a manner rotatable about their axis A. The two-part structure of the rolling element cage 28, consisting of a lower portion 50 and an upper portion 51 fixed thereon, can be clearly seen, wherein the end face of the lower portion 50, where the sliding guide is disposed, serves as a thrust ring 11.

[0042] In this regard, it should be emphasized that the illustrated embodiment of the driver with an (external) motor is only one possible technical solution, with the motor coupled to the driven component via a belt drive. Other drive concepts can also be considered in the same way. For example, an (integrated) hollow shaft driver implemented with a torque motor can be used, with its output directly coupled to a thrust ring or ring die. Direct rotational drive of rolling elements can also be used.

[0043] according to Figure 5 As illustrated, the ring die 8 is supported in a hollow piston-shaped bearing sleeve 43, which can rotate freely about the pressing axis X. This bearing sleeve can be axially adjusted by corresponding supplies from two hydraulic working chambers 47 in the cylindrical bore 45 of the base 2 to achieve radial feed of the rolling cone 13. In this case, the outer and inner rings of the (upper) bearing structure of the ring die 8, which is implemented as a tapered roller bearing 52, are supported by diagonally acting shoulders, enabling the transmission of particularly large axial forces from the bearing sleeve 43 to the ring die 8. This is correspondingly applicable to the support of the rolling element unit 9 on the hollow journal 48 with the same axial load.

[0044] In this case Figure 6 and Figure 7 Two design features are also shown. According to Figure 6 The inner contour 10 of the ring mold 8 is not mathematically a precise truncated cone, but rather (see radius R) slightly crown-shaped. According to Figure 7The inner contour 10 of the ring die 8 has a spiral or spirally arranged groove 53, which is used to discharge grinding debris, dirt, etc.

[0045] According to the enlarged diagram Figure 7 Partial area of ​​the radial press Figure 8 and Figure 8a The guidance of the rolling cone 13 within the rolling element cage 28 can be seen particularly clearly. The sliding support of the bearing element 49 on the sliding bearing plate 60 can also be seen. Similarly, it is shown how the bearing element is radially preloaded outward by two return springs 54, which are in the form of helical compression springs, so that the rolling cone 13 remains continuously against the inner contour 10 of the ring die 8. In this case, the return springs 54 (for illustration purposes, in...) Figure 8a (Only partially shown) The bearings are housed in generally cylindrical cavities 55, each defined by a two-cylinder shape. A first semi-cylinder 56 is provided on the side of each bearing member 49 and is radially defined externally by a bottom 57; a corresponding semi-cylinder 58 is provided on the rolling bearing cage 28 and is radially defined internally by a bottom 59. Therefore, the return spring 54, housed in the respective cavity 55, is supported on both the bottom 57 of the corresponding semi-cylinder 56 and the bottom 59 of the corresponding semi-cylinder 58. Furthermore, those skilled in the art will understand from the above description of other figures. Figure 8 and Figure 8a Details.

Claims

1. A radial press, comprising: - Base (2), - A hollow ring mold (8) supported on the base in a manner rotatable relative to the pressing axis (X), the ring mold having an inner contour (10) that tapers toward the pressing axis (X) and is rotationally symmetrical relative to the pressing axis (X), and - A rolling element unit (9) rotatable relative to the pressing shaft (X), the rolling element unit having a thrust ring (11) surrounding the pressing shaft (X) and a plurality of rolling elements (12) arranged around the pressing shaft (X) and at least partially tapering and rotationally symmetrical, the rolling elements being axially supported on the thrust ring (11) in a rotatable manner relative to the pressing shaft (X) with variable spacing and capable of rolling on the inner contour (10) of the ring die (8). The rotary drive acts on the ring die (8) and / or the rolling element unit (9) to rotate the ring die (8) and / or the rolling element unit (9) about the pressing axis (X), and the feed drive acts on the rolling element unit (9) and / or the ring die (8) to cause the rolling element unit (9) and the ring die (8) to adjust axially relative to each other along the pressing axis.

2. The radial press according to claim 1, characterized in that, The inner contour (10) of the ring die (8) and the rolling element (12) are truncated cones.

3. The radial press according to claim 2, characterized in that, The double cone angle of the rolling element (12) is equivalent to half the cone angle of the inner contour (10) of the ring die (8).

4. The radial press according to claim 2 or 3, characterized in that, The rolling element (12) protrudes slightly, and the cone angle of the rolling element varies continuously within the range of the extension of the rolling element along its own axis.

5. The radial press according to claim 1, characterized in that, The thrust ring (11) has a sliding surface (16), and the rolling element (12) is rotatably supported on a bearing (15), which is guided on the thrust ring (11) in a manner that allows it to move on the sliding surface (16).

6. The radial press according to claim 5, characterized in that, The sliding surface (16) is implemented through the surface of a replaceable sliding bearing plate (18).

7. The radial press according to claim 5 or 6, characterized in that, The sliding surface (16) is inclined to the pressing axis (X).

8. The radial press according to claim 5, characterized in that, The bearing component (15) is guided in the guide (17) of the thrust ring (11) in an anti-dislodgement manner.

9. The radial press according to claim 1, characterized in that, The base (2) is implemented as a shell, wherein the outer sleeve section (4) of the base at least partially surrounds the ring mold (8).

10. The radial press according to claim 1, characterized in that, The feed driver includes a pressure tube (19) coaxial with the pressing shaft (X).

11. The radial press according to claim 10, characterized in that, The pressure tube (19) is guided on the base by a linear guide (21) in a manner that allows it to move along the pressure axis (X).

12. The radial press according to claim 1, characterized in that, There is an odd number of rolling bodies (12).

13. The radial press according to claim 1, characterized in that, The rolling element unit (9) has a preload spring that preloads the rolling element (12) outward to abut against the inner contour (10) of the ring die (8).

14. The radial press according to claim 1, characterized in that, The surface of the rolling element (12) is shaped.

15. The radial press according to claim 14, characterized in that, It features a spiral-shaped design.

16. The radial press according to claim 14, characterized in that, The rolling element (12) has a spherical protrusion surface.

17. The radial press according to claim 14, characterized in that, The rolling element (12) has micro-teeth that extend in a closed annular shape within the corresponding circumference.

18. The radial press according to claim 1, characterized in that, The rotary actuator operates only on the ring mold (8).

19. The radial press according to claim 1, characterized in that, The feed driver operates only on the rolling element unit (9).

20. The radial press according to claim 1, characterized in that, The bearing structure of the ring mold (8) on the base (2) includes two spatially separated bearings (6, 7), wherein the point of action of the rotary actuator on the ring mold (8) is located between the two bearings (6, 7).

21. The radial press according to claim 1, characterized in that, The base (2) has a first notch (26) extending around the pressing axis (X), which is adjacent to the end face of the ring mold (8) corresponding to the smaller diameter of the inner contour (10).

22. The radial press according to claim 1, characterized in that, The ring mold is constructed of multiple components, in such a way that the ring mold includes a support ring and an insert that is replaceably received in the support ring and defines the inner contour.

23. The radial press according to claim 1, characterized in that, The thrust ring (11) is part of a rolling element cage (28) having a wall (29) including a second notch (30) in which the rolling element (12) is rotatably supported on its two end faces.

24. The radial press according to claim 1, characterized in that, Use cylindrical rolling elements or at least partially extended rolling elements instead of at least partially tapered rolling elements (12).

25. A radial press comprising: - Base (2), - A hollow ring mold (8) is supported on the base in a manner that fixes it to rotation relative to the base. The ring mold has an inner contour (10) that tapers toward the pressing axis (X) and is rotationally symmetrical with respect to the pressing axis (X). - A rolling element unit (9) rotatable relative to the pressing shaft (X), the rolling element unit having a thrust ring (11) surrounding the pressing shaft (X) and a plurality of rolling elements (12) arranged around the pressing shaft (X) and at least partially tapering and rotationally symmetrical, the rolling elements being axially supported on the thrust ring (11) in a rotatable manner relative to the pressing shaft (X) with variable spacing and capable of rolling on the inner contour (10) of the ring die (8). The rotary drive acts on the ring die (8) and / or the rolling element unit (9) to rotate the ring die (8) and / or the rolling element unit (9) about the pressing axis (X), and the feed drive acts on the rolling element unit (9) and / or the ring die (8) to cause the rolling element unit (9) and the ring die (8) to adjust axially relative to each other along the pressing axis.

26. A radial press comprising: - Base (2), - A hollow ring die (8) supported on the base in a manner rotatable relative to the pressing shaft (X), the ring die having an inner contour (10) tapering toward the pressing shaft (X), the inner contour of the ring die not being rotationally symmetrical, but having a plurality of bag-shaped accommodating portions (41) for rolling elements, the accommodating portions being evenly arranged around the pressing shaft (X) and inclined toward the pressing shaft (X), and - A rolling element unit (9) rotatable relative to the pressing shaft (X), the rolling element unit having a thrust ring (11) surrounding the pressing shaft (X) and a plurality of rotationally symmetrical rolling elements (12) arranged around the pressing shaft (X), the rolling elements being axially supported on the thrust ring (11) in a rotatable manner relative to the pressing shaft (X) with variable spacing and slidably supported in the bag-shaped receiving portion (41) in a manner rotatable about their own axis and movable along the axis of the associated bag-shaped receiving portion (41). The rotary drive acts on the ring die (8) and / or the rolling element unit (9) to rotate the ring die (8) and / or the rolling element unit (9) about the pressing axis (X), and the feed drive acts on the rolling element unit (9) and / or the ring die (8) to cause the rolling element unit (9) and the ring die (8) to adjust axially relative to each other along the pressing axis.

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