Patent Application
20250041925
The present invention relates to a radial press with at least six base jaws, which are disposed uniformly and concentrically around a press axis, and which can be moved by means of a drive unit radially toward the press axis and away from it, wherein the base jaws are respectively provided on the radial inside with a contact face as well as with mechanical retaining means for press jaws that can be mounted exchangeably on them.
In particular, the present invention relates to a radial press of the type indicated in the foregoing, in which a cutting tool comprising a plurality of cutting attachments mounted respectively on a base jaw is received in the tool mounting space bounded on the outside by the base jaws, wherein the cutting attachments respectively comprise a base structure and at least one of them further comprises a cutting structure, wherein further the base structure respectively has a bracing face bearing on the contact face of the associated base jaw as well as at least one engaging element cooperating with the mechanical retaining means of the associated base jaw, and wherein beyond that the at least one cutting structure protrudes toward the press axis from the associated base structure and has a cutting edge facing away from the bracing face of the associated base structure.
Radial presses suitable for radially pressed articles of the most diverse type (e.g. the permanent mounting of connecting fittings to the end of a piece of hose for establishment of a hydraulic hose line) are known in various concepts (e.g. hollow-piston press, pressure-plate press and yoke press) and diverse configurations. Examples are disclosed in DE 20 2016 100 660 UI, DE 20 2016 008 097 UI, DE 10 2016 106 650 A1, DE 10 2014 014 585 B3, DE 10 2014 012 485 B3, DE 10 2014 008 613 A1, DE 10 2011 015 770 A1, DE 10 2011 015 654 A1, DE 10 2009 057 726 A1, DE 10 2005 041 487 A1, DE 10 2005 034 260 B3, DE 601 21 915 T2, DE 298 24 688 UI, DE 199 44 141 CI, DE 199 40 744 B4, DE 101 49 924 A1, DE 41 35 465 A1 and DE 35 13 129 A1. Regardless of their respective design type and other technical features, the known radial presses are alike in that a plurality of base jaws of approximately wedge-shaped base cross section—eight base jaws are most common—disposed in a manner distributed uniformly around the press axis are moved uniformly in radial direction relative to the press axis by means of a (typically hydraulic) drive. In this situation, press jaws that have a pressing face matched to the geometry (especially the diameter) of the respective workpieces to be pressed can be mounted on the radial inside of the base jaws.
Radial presses of the type under consideration here are associated with a considerable investment expense. This is the case in particular for modern, highly precise high-performance presses. The costs associated with purchasing them may represent a significant financial burden, especially for workshops and comparable, relatively small facilities, in which the radial presses under consideration here are used.
A radial press of the generic type has become known from EP 3 178 579 B1. Compared with conventional radial presses (see above), an increase of the economic efficiency is possible if, just as according to EP 3 178 579 B1, a radial press of the type under consideration here equipped—to some extent in conflict with the purpose—with a specific cutting tool adapted to the technical characteristics of the radial press can also be used to perform tasks aimed at cutting (to the extent of severing) workpieces. It is precisely workshops and comparable, relatively small facilities, in which radial presses are used, that may benefit in this way from very considerable efficiency-enhancing effects. The workload of the radial press can be increased to a relevant extent, since diverse demanding cutting tasks that can be accomplished with a radial press that is also modified for execution of cutting tasks are encountered in typical workshops. The increased economic efficiency in those situations also benefits from the circumstance that, ideally, there is no need to purchase a specific, explicit cutting mechanism or machine (or even several such machines). Thus the space requirement that would otherwise exist is also not needed and, without a specific, explicit cutting mechanism or machine, maintenance and service expenses otherwise associated with it are also obviated.
Compared with the prior art that can be learned from EP 3 178 579 B1, an object underlying the present invention is to increase the economic efficiency still further, especially by improvements with respect to the useful life of the relevant radial press.
This object may be achieved, in that, in a generic radial press, the cutting tool has linear guide elements, which guide two base structures disposed diametrically opposite one another relative to one another with relative movability perpendicular to the press axis. By means of the linear guide elements implemented in the cutting tool itself, reactive forces or force components (transverse forces) occurring during cutting and acting between the two cutting edges with direction oriented transverse to the cutting direction are fed back within the cutting tool itself. Due to such a direct, closed internal flow of force within the cutting tool, transverse forces acting on the base jaws of the radial press are prevented. This is once again an effect of considerable importance for the useful life of the radial press. The linear guide elements that extend between the two base structures and couple them with one another in linearly guided manner may additionally achieve guidance if necessary of the workpiece or—after it has been severed—of the two workpiece parts.
Within the scope of the present invention, significant configuration latitude exists for constructing the cutting tool, i.e. especially the cutting attachments mounted on the base jaws of the radial press. Their constructive and structural configuration—as will become evident from the following explanations—can be optimized in terms of the respective cutting task while also taking into consideration the functional and structural characteristics of the respective radial press concept, wherein the flexible adaptation of the radial press to the respective cutting task with the least possible expense takes advantage of the circumstance that the radial press is already “innately” constructed, so to speak, in its basic version with a view to being equipped with different press jaws.
In a first preferred configuration of the invention, a cutting attachment facing the press axis and disposed opposite the cutting structure of another cutting attachment is provided with a backing structure having a workpiece contact face. In a specific version of this further development that is structurally particularly simple, the cutting tool inserted in the tool mounting space accordingly comprises precisely two cutting attachments, which are placed on two base jaws disposed diametrically opposite one another. One of those two cutting attachments has a cutting structure and the other, disposed opposite it, has a backing structure. During operation of this radial press, the cutting edge of the cutting structure severs the workpiece braced on the workpiece contact face of the backing structure, wherein the workpiece contact face of the backing structure is typically adapted in terms of its geometry to the geometry of the cutting edge and if necessary also to the workpiece. This backing structure may protrude from the associated base structure toward the press axis. In extreme cases, however, the backing structure may be part of the base structure itself, in that the workpiece contact face is formed by that surface of the base structure of the relevant cutting attachment which faces the press axis.
Another preferred further development of the invention is characterized in that at least two cutting attachments—respectively protruding toward the press axis from the associated base structure—have cutting structures with cutting edges that interact with one another in cutting relationship. Shearing in particular can be considered as such a cutting interaction that brings about severing of the respective workpiece. For this purpose, in a corresponding particularly preferred configuration of this further development, the cutting edges of two cutting attachments are disposed relative to one another—in a direction transverse to the direction of movement of the cutting attachments relative to one another—in parallel offset relationship; if the cutting edges were oriented perpendicular to the press axis, they would therefore be offset parallel to one another in the direction of the press axis. In the course of the closing movement of the radial press, a shearing action would be exerted on the workpiece as a consequence of the said parallel offset of the cutting edges.
For diverse cutting tasks to be performed with precisely the radial press modified according to embodiments of the invention, however, crimping is preferred over shearing as a cutting interaction by means of which the respective workpiece is severed. For this purpose, in a particularly preferred alternative configuration, the cutting structures have cutting edges that correspond to one another and are disposed opposite one another in relative direction of movement of the cutting attachments relative to one another, i.e. in the plane of movement. The cutting edges of the cutting structures of two cutting attachments correspond to one another in this sense when, at the end of the radial movement of the base jaws (idealized) oriented toward the press axis, they come together along a line of contact or become opposite one another along their extent with a minimum spacing (such as 0.2 mm), which depends, for example, on the material of the workpiece to be severed.
In this preferred implementation of the cutting attachments with cutting edges constructed to correspond to one another in such a way that they come together in idealized linear manner when the cutting tool is completely closed, the relevant idealized line of contact may—due to straight construction of the two cutting edges—be straight. However, this is in no way imperative. Depending on the intended use, as will be explained in more detail further on, cutting-edge geometries deviating from a straight line in one or two dimensions may also be considered. Incidentally, this is also true for the two cutting edges—offset from one another and exerting shearing action on the workpiece—of a corresponding cutting tool (see above) for generating a non-planar cut. Due to the construction of the cutting edges of the cutting attachments in such a way that they correspond to one another and become opposite one another in relative direction of movement of the cutting attachments, it is possible—in contrast to the case of cutting edges that are offset from one another and exert a shearing action on the workpiece—to prevent reactive forces offset asymmetrically relative to one another, i.e. especially in the direction of the press axis, from acting on the base jaws carrying the cutting attachments. This may be of considerable practical importance, because various typical radial presses of conventional design type react to such asymmetric load profiles with increased wear and thus shortened useful like. This would be counterproductive in relation to the present object, which is aimed at increased economic efficiency.
A further advantage of this configuration having great practical relevance is that, for severing the workpiece, not only two cutting structures may be used, as in shearing, but especially also three cutting structures, as in a radial press equipped with six base jaws for example, or four cutting structures, as in a radial press equipped with eight base jaws for example. In such cases the cutting edges may preferably be respectively angled, with a pronounced pointed tip. By way of example, this would actually have an angle of 120° in the case of three cutting structures and an angle of 90° in the case of four cutting structures. In these configurations characterized by the existence of more than two cutting structures, not only is it a positive consequence that ejection of the workpiece during severing is prevented and that penetration of the cutting edges—forming a pointed tip—into the workpiece is facilitated, but also it is advantageous that the transmission of force is more uniform and the flow of force in the radial press is more favorable, especially in radial presses of hollow-piston or pressure-plate design style.
To prevent misconceptions, it must be pointed out once again as a precaution that the cutting edges explained in the foregoing and disposed opposite one another in a cutting plane are in no way absolutely required to be in contact with one another at the end of the cutting movement, certainly not over the entire length. To the contrary, such configurations are advantageous for various cutting tasks, such as severing of various workpieces, in which the cutting edges maintain a distance from one another or define between one another an open space—if necessary over part of their length—that has a shape (such as round, oval or polygonal) appropriate for the respective workpiece. Furthermore, it must be pointed out that the base jaws equipped with cutting attachments are in no way absolutely required to move synchronously; although this is actually appropriate for most applications of embodiments of the invention, individual cases are also entirely possible in which a radial movement of the base jaws relative to one another takes place in a presettable sequence in time relative to one another (and if necessary overlapping one another), provided the configuration of the drive unit is suitable (e.g. by means of independently controlled individual drives).
According to another preferred further development of the invention, the contact faces of the base jaws as well as the bracing faces of the base structures of the cutting attachments are cylindrically curved in a manner corresponding to one another. This may favor self-adjusting or self-securing mounting of the cutting attachments on the associated base jaws in the sense that lateral forces generated during the cutting process may be diverted better into the base jaws, possibly contributing to lightening of the load on the pair comprising retaining means and engaging elements used for securing the cutting attachments in position. In addition, this configuration contributes to a favorable flow of force while reducing harmful stress peaks. Particularly preferably, the base structures of the cutting attachments project over the associated base jaws in circumferential direction. Such projections form (at least partly) covers for the gaps present between the relevant base jaws and the two neighboring base jaws. Thus the danger is reduced that workpiece splinters or other fragments formed during the cutting process will travel into the relevant gaps.
The effect considered in detail in the foregoing is particularly noticeable when, according to yet another preferred configuration of the invention, the two cutting attachments are mounted on base jaws disposed vertically one above the other. Handling during use of the radial press modified according to embodiments of the invention also benefits from such an arrangement of the cutting attachments, since the workpiece to be cut may be deposited if necessary on the cutting edge of the lower cutting attachment, thus reducing the load on the user and permitting particularly precise executing of cuts.
In connection with the arrangement of the cutting attachments disposed vertically one above the other in the manner explained in the foregoing, and furthermore also because of the inherent statics of the relevant machine concept and of the flow of force specifically characteristic to it, the present invention is preferably implemented in radial presses constructed as so-called yoke presses, i.e. in such radial presses that have a lower yoke and an upper yoke, the vertical spacing between which can be varied by means of at least one drive element (e.g. designed as a hydraulic cylinder). In this case, particularly high cutting forces can be achieved by implementation of the present invention. This is true in particular when the cutting attachments are placed on those two base jaws which are disposed in fixed position relative to the lower yoke or to the upper yoke.
According to yet another preferred further development of the invention, the cutting tool comprises two wall elements that extend substantially parallel to the press axis and laterally bound the (temporary) space between the two base structures when the cutting tool is closed. Thus—at least over a partial range of cutting movement of the two cutting attachments relative to one another—the region in which the workpiece to be cut will be severed is closed off at the sides. This likewise contributes—see above—to reducing the danger that workpiece splinters or other fragments formed during the cutting process will travel into the gaps present between the relevant base jaw and the two neighboring base jaws. In the case of a vertical cutting direction, the said wall elements are mounted particularly preferably on the base structure of the lower cutting attachment or form a part thereof.
Regardless of their detailed geometry (straight or else deviating therefrom in one or two dimensions; see above), the two cutting edges are particularly preferably oriented at least substantially transverse to the press axis for diverse typical applications of the present invention. Hereby, loads leading to asymmetric stress profiles—which are potentially detrimental to the useful life of the radial press—are prevented as much as possible. In addition, this configuration of the cutting tool makes it possible to sever workpieces (such as hoses, bars, tubes, rods, chain links, etc.) inserted therein with orientation parallel to the press axis in a way that achieves the smallest area of cut and thus optimized force. For an optimum result during other applications (e.g. blasting of tubes, sleeves, nuts, etc.), however, it proves favorable when the two cutting edges—again regardless of their detailed geometry (straight or else deviating therefrom in one or two dimensions; see above)—are oriented at least substantially parallel to the press axis. For yet other applications, cutting edges oriented obliquely relative to the press axis prove to be favorable. Against this background, a particularly preferred configuration of the invention is characterized in that the cutting structures are mounted—with respect to the orientation of the respective cutting edge—adjustably on the associated base structure.
For handling of the radial press modified according to embodiments of the invention, namely the execution of cutting tasks with good reproducibility, it is of particular advantage when the cutting tool, according to yet another further development of the invention, has at least one workpiece holder provided in the region of a front side of a base structure. Such a workpiece holder may be mounted, especially exchangeably, on the associated base structure, which with little expense—promoting reproducibility—permits specific adaptation of the cutting tool to the most diverse cutting tasks and workpieces. According to a particularly preferred configuration, the workpiece holder (if necessary mounted exchangeably on the associated base structure) has the form of a mandrel; this proves to be very advantageous, for example, for severing of chains, when a link of the chain to be severed is suspended on the mandrel. If the mandrel is spaced so far apart from the two cutting edges that the chain link to be severed is itself not suspended but instead a link spaced away from it is, the mandrel contributes after cutting to retaining the relevant portion of the severed chain and preventing it from dropping downward. This is also advantageous from the viewpoint of industrial safety.
A largely comparably positive result—according to an alternative preferred embodiment—can be achieved when the workpiece holder (if necessary mounted exchangeably on the associated base structure) has the form of a metal sheet provided with a cutout, wherein the cutout is dimensioned such that the chain link next to the chain link to be severed is introduced therein.
According to yet another very advantageous further development of the invention, centering and/or retaining attachments are mounted on at least two further base jaws of the radial press and have workpiece holders offset axially relative to the cutting structures of the cutting tool. Particularly preferably, these centering and/or retaining attachments are sufficiently flexible that workpiece contact faces of the workpiece holders are able to shorten their spacing from the associated base jaws against a preload. During closing of the radial press, i.e. when the base jaws move radially (and preferably synchronously) toward the press axis, the workpiece holders of the centering and/or retaining attachments on the workpiece to be severed come into contact before or shortly after the blades of the cutting tool are placed on the workpiece; in this way they retain the workpiece in position during the (further) severing process and prevent it from being ejected or slipping, thus contributing to neat execution of the cut. A further very advantageous effect of the centering and/or retaining attachments may exist in that, even after cutting has taken place, they still retain the relevant portion(s) of the workpiece that is to be severed or has been severed and prevent it or them from dropping downward and/or from being catapulted out of the cutting tool. This is again very advantageous from the viewpoint of industrial safety.
Several preferred exemplary embodiments of the present invention will be explained in more detail hereinafter on the basis of the drawing, wherein
The radial press underlying the various exemplary embodiments of the invention presented in the drawing and constructed conceptionally as a kind of yoke press corresponds to the pertinent prior art with which the authoritative person skilled in the art is familiar. In this context, the invention is specifically illustrated on the basis of the HM 325 radial press of Uniflex-Hydraulik GmbH, 61184 Karben (Germany).
The radial press in question comprises a base 1, a lower yoke 2 that is stationary relative to it and an upper yoke 3, which can be moved vertically up and down relative to lower yoke 2. For this purpose, upper yoke 3 is guided displaceably in two guides 4 projecting from base 1. Also shown are upper end portions 5 of two hydraulic drive cylinders 6, which in known manner are part of the drive unit that brings about the relative movement of upper yoke 3 and lower yoke 2 relative to one another. And operator control unit 7, which among other purposes functions to set up the radial press by calling up a press program that runs in the machine control system and to adapt it for specific procedures, is also shown.
The radial press is equipped in known manner with base jaws 8, which are disposed uniformly and concentrically around a press axis X and which, by virtue of the relative movement of upper yoke 3 and lower yoke 2 relative to one another, can be moved synchronously in radial direction toward press axis X while upper yoke 3 is being lowered and in radial direction away from press axis X while upper yoke 3 is being raised. Base jaws 8 are respectively provided on the radial inside with a cylindrically curved contact face 9 for press jaws that can be mounted exchangeably on them. Furthermore, base jaws 8 comprise—in their interior—mechanical retaining means in the form respectively of a spring-loaded retaining pin which, when a press jaw is placed on the relevant base jaw 8, engages interlockingly in a corresponding groove of a retaining peg provided on the radial outside of the relevant press jaw and inserted into bore 10 of base jaw 8. Since the radial press used in the exemplary embodiments corresponds in the foregoing scope to the sufficiently known prior art, to which reference is made, more extensive explanations are unnecessary.
According to
Each of the two cutting attachments 12.1, 12.2 comprises a base structure 13 and a cutting structure 14. This base structure 13 is provided respectively with a cylindrically curved bracing face 15 (see
Cutting structure 14 protrudes respectively toward press axis X from base structure 13 of the relevant cutting attachment 12. This is constructed in the form of a prism with a base region 14A (having wall portions 18A oriented parallel to one another) and a cutting region 14B (having wall portions 18B intersecting one another at an acute angle). The cutting edge 19 of the last-mentioned wall portion 18B then defines a blade—like cutting edge 20. Cutting edges 20 of the two cutting attachments 12 are then disposed opposite one another in relative direction of movement B of cutting attachments 12, i.e. in the plane of movement of cutting structures 14. They correspond to one another, in that they are in contact with one another (in idealized manner) along a line of contact when the radial press is closed (
Cutting structures 14 consist of hardened steel. They are mounted—via conventional dowel pin connections—on the respectively associated base structure 13. This makes it possible to post-machine cutting structures 14 when they are removed from base structures 13 or to replace them in case of wear and tear. In addition, given suitable construction of base structures 13, this permits adjustable mounting of cutting structures 14 thereon in different angular arrangements, e.g. such as angles of 30°, 45° and/or 60 relative to press axis X or parallel to it.
In the exemplary embodiment according to
In the modification, illustrated in
According to the second exemplary embodiment illustrated—only within the scope of cutting tool 11—in
For application of this cutting tool 11, one consideration is mounting of the four cutting attachments 12 on the base jaws 8 in 12 o'clock, 3 o'clock, 6 o'clock and 9 o'clock positions, as is also mounting turned by 45° relative to press axis X.
The third exemplary embodiment illustrated—again only within the scope of cutting tool 11—in
The fourth exemplary embodiment illustrated—again only within the scope of cutting tool 11—in
The fifth exemplary embodiment illustrated—again only within the scope of cutting tool 11—in
Unlike the cutting tools according to the five exemplary embodiments explained in the foregoing, those according to
In the sixth exemplary embodiment of the invention illustrated—again only within the scope of the cutting tool—in
In contrast, in the seventh exemplary embodiment of the invention illustrated in
It is further evident in
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2022 102 074.4 | Apr 2022 | DE | national |
This application is a continuation under 35 U.S.C. § 120 of International Application PCT/EP2023/059885, filed Apr. 17, 2023, which claims priority to German Application No. 20 2022 102 074.4, filed Apr. 19, 2022, the contents of each of which are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2023/059885 | Apr 2023 | WO |
| Child | 18921136 | US |
