EP3814032A1

EP3814032A1 - Bending tool comprising a spacer element

Info

Publication number: EP3814032A1
Application number: EP19736290.8A
Authority: EP
Inventors: Harald Fenzl; Alfred HASELBÖCK; Heinz Leumüller; Giovanni Vidotto
Original assignee: Trumpf Maschinen Austria GmbH and Co KG
Current assignee: Trumpf Maschinen Austria GmbH and Co KG
Priority date: 2018-06-27
Filing date: 2019-05-29
Publication date: 2021-05-05
Also published as: AT521173B1; AT521173A4; CN112165997A; CN112165997B; WO2020000003A1

Abstract

The invention relates to a cranked bending tool (1) for a bending machine, said tool comprising a tool body (3) which has at least one tool shaft (4) for receiving at least part of the bending tool (1) in a receiving shaft provided therefor, and which tool body (3) has a tool centre of gravity outside a vertical plane of symmetry of the receiving shaft. At least one movement means (8) is provided on the tool shaft (4) for moving the bending tool (1) in the longitudinal direction (22) of the bending machine and for receiving same in a groove, at least one side of said movement means being excellently designed on the tool shaft (4) relative in each case to a tool shaft surface (7). In addition, at least one spacer element (2) is designed which is provided for applying a supporting force (23) which counteracts the tilting moment caused by deviation of the tool centre of gravity from the plane of symmetry in the transverse direction (21). The at least one spacer element (2) comprises at least one rolling body (25) which is mounted with a prestressing force (24), is mounted on or at least partially inside the tool body (3) so as to be movable at least in the direction of the prestressing force (24), and at least part of which is arranged excellently relative to a surface of the tool body (3) which is preferably adjacent to the at least one rolling body (25).

Description

Bending tool with spacer

The invention relates to a cranked bending tool for a bending machine, in particular a die bending machine, which comprises a spacer element that is pretensioned with a pretensioning force to compensate for a tilting moment.

Bending tools, which are used as the upper tool in a bending machine for forming a sheet metal part, can often have a tool body with a complicated geometry. It may happen that the tool body is cranked, that is to say deviated from the bending direction at least simply angled. With such tool geometries, the center of gravity of the tool is often no longer in a vertical plane of symmetry of the tool holder or the tool shank, but offset laterally in a transverse direction.

The lateral offset of the tool center of gravity from the plane of symmetry causes a tilting moment of the cranked tool on and / or in the tool holder. When changing the bending tool, this tilting moment can lead to increased wear of the bending tool and / or the tool holder on the contact surfaces, up to jamming of the bending tool in the tool holder.

In order to prevent damage to the tool, in WO2014 / 007640 Al was struck in the tool shank or on the tool shoulder of a bending tool to attach a rigidly arranged roller, which should facilitate the movement of the bending tool in the receiving shaft. The rigidly mounted roller should be made very stiff in order to be able to support the bending tool on the tool holder.

In future, ever lower manufacturing tolerances and / or very high accuracy of fit of the tool holder and the tool body will be required. This means that the bearing and / or movement of the tool shank in the receiving shaft of the tool holder must be as free of play as possible. Systems known from the prior art, as disclosed, for example, in WO2014 / 007640 A1, are, however, only of limited practical use since they have the disadvantage that the rollers can wear out heavily in part and through a common clamping of the bending tool in the tool holder can be damaged. In addition, an automated changing process of a bending tool by external manipulators and / or robots is very difficult.

The object of the present invention was to overcome the disadvantages of the prior art and to provide a cranked bending tool which enables wear on the bending tool and / or the tool holder to be reduced. A further object of the invention is that the displacement resistance of a bending tool in the tool holder is reduced and jamming of the bending tool in or on the tool holder is prevented. Furthermore, the bending tool according to the invention serves to make it usable on both sides, that is to say essentially independently of the direction of insertion.

This object is achieved by a bending tool according to the claims.

The cranked bending tool according to the invention for a bending machine, in particular a die bending machine, comprises a tool body, at least one moving means and at least one spacer element. The tool body has at least one tool shaft for at least partially receiving the bending tool in a bending direction in a receiving slot provided for the tool holder, the tool body having a tool head adjoining the tool shaft in the bending direction, which has a tool center of gravity outside a vertical plane of symmetry of the receiving shaft and / or the tool shank and has a tool shoulder on at least one side in a transverse direction. At least one moving means is formed on the tool shank for moving the bending tool in the longitudinal direction of the bending machine for receiving in a groove, said moving means being excellently designed at least on one side on the tool shank relative to a respective tool shank surface. At least one spacer element is designed to apply a supporting force that counteracts a tilting moment caused in the transverse direction by the deviation of the center of gravity from the plane of symmetry on at least one surface of the tool holder. The at least one spacer element comprises at least one rolling element mounted with a preloading force, which is movably mounted on or at least partially within the tool body at least in the direction of the preloading force and at least partially relative to one, preferably the surface of the tool body adjacent to the at least one rolling body is arranged in an outstanding manner.

In simple terms, the tilting moment acts around the longitudinal axis of the bending tool or the tool holder and causes the bending tool to be pressed against at least one contact point. By designing the at least one spacer element by means of at least one rolling element, which is directly or indirectly preloaded with a preload force, the at least one spacer element can compensate for the tilting moment by transferring a supporting force from the bending tool to the tool holder. As a result, the friction between the receiving shaft and the tool shaft and / or between the underside of the tool holder and a tool shoulder or the tool shoulder plane can be reduced when the bending tool moves in the tool holder. The reduction in friction enables a reduction in wear on the contact surfaces mentioned. In addition, jamming of the bending tool on and / or within the tool holder can be avoided.

Furthermore, the movable mounting or pretensioning of the at least one rolling body in the direction of the pretensioning force makes it easier to insert the bending tool shaft into the receptacle provided for the tool receptacle. As a result, such a bending tool can be changed relatively easily and quickly, and the compensation of the tilting moment can lead to an increase in safety and reduced wear.

Furthermore, it can be expedient if the at least one rolling body for applying the supporting force, normal to the bending direction or transverse direction on an inside of the receiving shaft and / or in the bending direction on an underside of the tool holder, is arranged on and / or at least partially in the tool body is.

The movable mounting or pretensioning of the at least one rolling element in the direction of the pretensioning force thus brings about an automatic coupling of the rolling element to a corresponding surface of the tool holder. This is particularly advantageous in the case of an automated change of a bending tool, since a robot or the like does not - to _¬ additional mechanism must operate and the at least one spacer element or Rollkör per can at least temporarily completely withdraw behind a surface of the tool body.

In addition, by means of the suitable positioning of the at least one spacer element on the tool body, an optimum can be found with regard to the required supporting or prestressing force and the space requirement on and / or within the tool body. For example, the relatively short lever arm when positioning a spacer on or within the tool shank requires a higher pretensioning force to apply the required supporting force to the inside of the receiving shaft than if the spacer is arranged on or within a tool shoulder, since a size may be present here lever arm can be used.

There may also be more than one spacer element on the tool body, in particular in the longitudinal direction. It is also conceivable that a spacer element for applying a part of the supporting force on the tool shaft relative to the inner surface of the receiving shaft, and a further spacing element for a part of the supporting force on the tool head in the direction of the underside of the tool holder. In this way, the required partial pretensioning forces can be selected to be relatively low, which makes insertion of the bending tool particularly easy to accomplish.

Furthermore, it can be provided that the at least one spacer element has an adjusting device for adjusting the amount of the pretensioning force.

The advantage of a United adjusting device is that a simple adaptation to different tool geometries and / or tool weights and the associated supporting forces or pretensioning forces can be carried out. This can e.g. after repairing a bending tool can be used to adjust the supporting force to a changed position of the tool center of gravity.

Such an adjustment device can be formed, for example, by a spring element, preferably a screw, which can apply a predeterminable spring force or pretensioning force by means of an adjustable spring travel. Likewise, a Ver adjusting device, for example An adjustable support from a spring element, such as a bending rod, forms out and include adjusting screw. An adjusting device is advantageously accessible from the outside, so that in the limit case, even with a bending tool taken up in the tool holder, an adjustment or setting of the pretensioning force can be carried out.

In addition, it can be provided that the spacer element comprises at least two rolling elements, which are preferably arranged next to one another in a rolling element receptacle.

In this way, an improved transmission of the supporting force can take place at several contact points, which enables a lower local surface pressure of the respective rolling elements in contact with a surface of the tool holder. On the one hand, this lowers the resistance or force when inserting the bending tool into the

Receiving shaft and can also reduce wear.

Also advantageous is a configuration according to which it can be provided that the at least one spacer element comprises a rolling element receptacle and at least one limiting element, which limiting element for limiting deflection of the rolling element receptacle or of the rolling element by means of at least one fastening means with the tool body in the direction of Preload is movably connected.

At least one rolling element is rotatably supported in the rolling element receptacle, the limiting element on the rolling element receptacle being able to be arranged laterally and internally in such a way that limited movement of the rolling element receptacle and thus of the rolling element is made possible. Such a limiting element can, for example, be movably connected to and / or in the tool body by or in a spacer element housing, as a result of which the respective spacer element is secured against loss by, for example, falling out and / or falling. In addition, such a delimitation element serves to ensure that the spacer element or the rolling body does not protrude beyond the surface of the tool body by a predeterminable height, which is particularly advantageous for easier insertion. A limiting element can be formed, for example, by a groove or an appropriately designed extension of the rolling body receptacle in order to accommodate the fastening means at least partially. In the simplest case, the fastening means can be a screw, the head of which serves as loss protection and whose thread and / or shaft or threadless part serves as a guide and stop for the limiting element in the direction of the pretensioning force.

According to a further development, it is possible for the at least one spacer element to be arranged in a spacer element housing, which is designed to accommodate at least one of the rolling element receptacles and the at least one limiting element, and to support the adjusting device with respect to the rolling element receptacle.

Such a spacer element can be regarded as a functional unit, which is relatively easy to manufacture and also enables the adjusting device to be supported within the spacer element housing and not necessarily on the tool body. In this way, a type of “retrofit element” can be created in a simple manner, which can be attached and / or exchanged relatively easily on and / or within an existing tool body.

Furthermore, it may be expedient if the at least one spacer element on the outside of the tool head is arranged to support the bending tool on the underside of the tool holder.

Such an arrangement is advantageous because good external accessibility for e.g. the setting of the preload is given. In addition, a comparatively large lever arm between the rolling body and the plane of symmetry is used, as a result of which the required supporting force or pretensioning force can be selected to be relatively low.

In addition, it can be provided that the spacer element is designed as a bending rod such that the at least one rolling element is arranged at a free end of the bending rod and a fixed end of the bending rod is fixed in the tool body, preferably the tool head, normal to the bending direction and / or in the bending direction is. The bending rod has a predeterminable flexibility in at least one direction, as a result of which the prestressing force can be adjusted essentially by the geometry of the bending rod, in particular the local cross section of the bending rod, the rolling body diameter and the available bending length. A bending rod is relatively simple and inexpensive to manufacture. The bending rod can be received in a receiving opening provided for this purpose, which can also be designed as a bore, for example, within the tool body. The receiving opening advantageously does not penetrate the tool body and has a larger diameter than the bending rod or the rolling body in order to enable the spacer element to move at least in the direction of the prestressing force. The fixed end is advantageously screwed into the tool body and the at least one rolling body is rotatably attached by the free end.

Furthermore, it can be provided that the at least one rolling element is at least partially arranged in an outstanding manner opposite the upper side of the tool shoulder and the rolling element is fastened in the tool head with the fixed end of the bending rod in the bending direction relative to the tool holder in order to apply the supporting force in the bending direction.

In this way, a particularly large bending length of the bending rod can be realized with stiffness or resilience that can be easily set or predefined. The rolling element can be arranged in such a way that it protrudes transversely over the surface of the tool shoulder. The free end and / or the rolling element is preferably aligned in the transverse direction or even set back behind the surface of the tool head which is adjacent in the longitudinal direction. In this way, protruding elements over the tool body are avoided, which can hinder handling of the bending tool. Among other things, this favors the use of automated tool changing devices.

According to a particular embodiment, it is possible that the bending rod comprises at least one threaded section for receiving the bending rod in the tool head and / or tool shank, a bending section with a predeterminable bending length, and a rolling body section, and the adjusting device for adjusting the pretensioning force by adjusting a predeterminable one Support distance between the threaded section and the rolling body section, the bending section is arranged at least partially supporting. The threaded section is provided as a fixed end for receiving in the tool body, while the rolling body section for receiving the at least one rolling body is arranged at the free end of the bending rod. Between these sections, the bending length available for exercising and / or adjusting the pretensioning force extends along the bending section. The adjusting device of this embodiment preferably comprises an adjusting screw and / or a spindle drive which is rotatably mounted in the tool body. The Ver adjusting device can also have a support element which is movable parallel to the bending rod and is designed to cooperate with the adjusting screw or the spindle drive. In this way, a two-point mounting of the bending rod can be formed by means of the adjusting device. The free bending length of the bending rod can be set relatively easily by adjusting the support distance from the threaded section, as a result of which the prestressing force can be adjusted. The support element can, for example, be a sleeve or a C- or V-shaped profile in order to support the bending rod at least on one side, preferably with a covering.

According to an advantageous development, it can be provided that the bending bar is designed as a waisted bending bar, the bending section being designed as a first waist section and the rolling body section being designed as a second waist section and at least one waist section diameter of the first and / or second waist section being smaller than a threaded section diameter is.

It has been shown that a decrease in cross section of the bending rod from the threaded section to the free end, preferably as two waist sections, can lead to an increase in the fatigue strength of the bending rod. In addition, the smaller diameter of the bending section and / or rolling body section enables a lighter construction of the bending rod. The smaller waist section diameters can also be used to optimize the rigidity or the prestressing force of the bending rod in a relatively simple manner.

The waist section diameters, in particular of the first waist section or of the bending section, can also not be designed to be continuous, that is to say following a mathematical function. This can be used by the person skilled in the art to provide different local waist section diameters which optimize the rigidity requirements along the bending rod with regard to the necessary prestressing force and / or fatigue strength. In particular, it can be advantageous if the adjustment device for adjusting a predeterminable support distance comprises a preferably sleeve-shaped support element that at least partially surrounds the bending section.

This measure enables a two-point mounting of the bending rod at the fixed end and on the support element of the adjusting device to be designed relatively simply and stably. The at least partial sheathing and, in particular, a sleeve-shaped support element can prevent local deflection of the bending rod in the direction of the prestressing force to be applied to the support element, so that improved and more stable storage can be achieved.

Furthermore, it can be provided that at least two movement means in the longitudinal direction are formed next to one another as a sliding element or preferably as a rolling element.

This measure allows the local friction and / or the local surface pressure to be reduced to the respective movement means, as a result of which the risk of wear and the tendency to wedge the bending tool in the tool holder can be reduced. The sliding elements are advantageously formed from a material with a low coefficient of friction compared to the tool holder and high mechanical strength. Polymers such as PTFE, PEEK, PPSU, PAEK or the like are preferably used because they can also have a high resistance to solvents and / or lubricants. The use of rolling elements, which are similar to the rolling element as e.g. ball-bearing rollers can be formed. The advantage of the rolling elements is the very low rolling friction and high mechanical stability.

In addition, it can be provided that at least two movement means in the transverse direction are formed on opposite sides of the tool shank, preferably symmetrically opposite one another.

This allows an improved load transfer of the weight of the bending tool into the tool holder and can be used in particular in combination with at least one spacer element Compensation of the tilting moment cause a significant reduction in the wear of the moving means.

In a special embodiment, the at least one movement means can be formed in one piece with the tool shank as an extension.

Such a movement means acts as a sliding element and is designed as an integral extension of the tool shank. Such sliding elements can be taken into account in the manufacture or machining of the tool shank and can thus be easily manufactured. It is particularly advantageous here if at least this movement means, formed as an extension of the tool shank, is coated and / or coated with a surface layer with a low coefficient of friction, such as PTFE. Carbon-based low friction layers, such as amorphous carbon (DLC), are particularly suitable as the surface layer, as a result of which the friction of the at least one extension can be efficiently reduced.

All of the design options according to the invention also have the effect that the tool shank or the bending tool can be inserted into the tool holder on both sides, since the compensation of the tilting moment by the at least one spacer element can be carried out essentially without additional changes to the tool holder.

Furthermore, for temporary fastening of the bending tool in the tool holder, clamping or clamping systems are generally used, which clamp the bending tool on the tool shaft in one or more clamping grooves provided for this purpose. In the best case, the top of the tool shank is pressed against the receiving shaft and any existing tool shoulders are pressed against the underside of the tool holder. According to the invention, in the case of a tool clamping or clamping, the at least one spacer element moves back behind the respective surface of the tool body, as a result of which the clamping process can take place unimpeded and a crooked “clamping” of the bending tool can be efficiently avoided. In addition, damage to the clamping or clamping systems, the tool holder and / or the bending tool can be avoided. The present invention can also be applied analogously to bending tools with a tool center of gravity in the plane of symmetry. It is in the sense of the present invention that the above-mentioned embodiments of cranked bending tools with spacer elements designed according to the invention also for compensating for tilting moments also in the transverse and / or longitudinal direction in the case of non-cranked bending tools or cranked tools whose tool center of gravity lies in the plane of symmetry can be. The tilting moments of such bending tools can occur due to a displacement of the bending tools in the longitudinal direction and can cause oscillating movements and / or jamming. The spacer elements can be arranged, for example, on both sides in the transverse direction on the tool body in order to minimize oscillating movements and / or jams during the insertion process into the tool holder, as a result of which the running-in speed can be increased and the set-up time can be reduced.

According to an advantageous development, it can be provided that the at least one movement means comprises a rolling pin, which rolling pin is rotatably mounted relative to the tool body by means of at least one rotary bearing element within the tool shaft. This allows cranked bending tools, which act as upper tools, when the clamping device is inactive, particularly process-stable, in particular smoothly and without jamming, displaced relative to their rail-like tool holder and positioned as required.

In particular, it can be advantageous if the at least one rotary bearing element is formed by at least one slide bearing element or roller bearing element which is held, in particular pressed in, in a receiving bore of the tool shaft. This enables the bending tool to be constructed in a robust and, at the same time, as economical as possible.

Furthermore, it can be provided that the at least one rolling pin is formed in one piece and passes through the tool shank with the interposition of the at least one rotary bearing element in such a way that its opposite end sections each protrude relative to the opposite tool shank surfaces. The one-piece rolling pin offers a high level of robustness, while the at least one rotary bearing element high storage stability guaranteed. In addition, reliable, slidably movable guidance of the bending tool relative to the tool holder and / or relative to guide rails away from the bending machine can thereby be achieved.

In addition, it can be provided that the at least one spacer element comprises a roller body, in which roller body at least one roller body designed as a cylindrical roller body is rotatably mounted. This creates a particularly robust and at the same time inexpensive to implement spacer element. In particular, this forms a functionally combined sliding and rolling element, the “sliding block” of which acts as a receiving body for the at least one rolling element.

Also advantageous is a configuration according to which it can be provided that the at least one cylindrical rolling element is held in at least one bore formed in the rolling element receptacle, a longitudinal axis of the at least one bore being positioned such that a partial section of the lateral surface of the cylindrical one Rolling body protrudes towards an outer surface of the rolling body receptacle. This results in a wear-free and at the same time high-strength rotary bearing for the cylindrical rolling element. Furthermore, a highly stable and mechanically reliable rotary bearing can be achieved for the at least one rolling element designed as a rolling element.

According to a development, it is possible for the rolling body receptacle to be accommodated in sections in a recess in the at least one tool shoulder or in the at least one tool shaft surface and to be resiliently mounted relative to this recess by applying the prestressing force. This creates a distance element which on the one hand enables the cranked bending tool to move easily when the clamping device is inactive and on the other hand ensures exact or planned alignment relative to the tool holder when the Klemmvor direction on or in the tool holder is activated. In addition, punctual load peaks or damage risks for the bending tool and / or the tool holder can be kept aside. Furthermore, it may be expedient if the rolling body receptacle has a run-up slope in at least one of its end sections related to the longitudinal direction or at least in its central section has a convex surface. As a result, the reliability and smooth operation of a bending tool changing process and / or a bending tool positioning process can be further improved.

In addition, it can be provided that the at least one cylindrical rolling element is formed from metal and the rolling element receptacle is formed from a different material, in particular from plastic. Good long-term stability of the rolling element can thereby be achieved. In addition, a wear-free or friction-minimized rotary bearing can be achieved for the rolling element.

Furthermore, it can be provided that the pretensioning force acting on the rolling body receptacle and the at least one rolling body is provided by at least two spring elements spaced apart from one another in the longitudinal direction and preferably acting on the end sections of the rolling body receptacle. As a result, the roll body receptacle can be stored in a manner that is as tilt-free as possible and thus also functionally reliable.

Finally, it can also be expedient if the at least one rolling body has a rolling surface that increases friction with respect to metallic surfaces, in particular made of a plastic, preferably of an elastomeric plastic. It can thereby be achieved that the rolling body is reliably rotated or rolls relative to the bending tool when supporting forces and displacement forces are present. Undesired grinding movements of the rolling body with respect to the tool holder or with respect to other holding or guide rails can thereby be avoided. In addition, a relatively quiet moving or changing process of bending tools can be achieved. This is particularly the case when the bending tools are moved at relatively high speeds via transitions, transverse gaps or slightly offset guide elements.

The invention can also be defined by a bending machine or by a tool holder of a bending machine which holds the bending tool described herein. For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Each show in a highly simplified, schematic representation:

Fig. 1 schematic overview representation in an oblique view of a cranked bending tool in the tool holder;

2 shows schematic sectional views of a bending tool with differently arranged spacer elements on or within the tool body (a-f);

3 shows a schematic representation of an exemplary embodiment of a bending tool with a spacer element on or in the tool shank with a rolling element (a) or two rolling elements (b);

Fig. 4 is a schematic sectional view of an embodiment of a bending tool with a spacer with a spacer housing;

Fig. 5 is a schematic sectional view of an embodiment of a bending tool with a spacer which is designed as a bending rod (a) or waisted bending rod and adjusting device (b);

Fig. 6 is a perspective view of a cranked bending tool with several

Spacer elements, each of which comprises spring-mounted flexible rods;

FIG. 7 shows a cross section through the bending tool according to FIG. 6 in the region of a spacing element;

Fig. 8 is a perspective view of a cranked bending tool with several

Spacer elements, which include spring-loaded roller body receptacles;

9 shows a cross section through the bending tool according to FIG. 8 in the region of a spacing element; Fig. 10 shows an alternative embodiment to the distance element illustrated in Fig. 9.

In the introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component designations, and the disclosures contained in the entire description can be analogously applied to the same parts with the same reference numerals or the same component designations. The location information selected in the description, e.g. above, below, laterally, etc. based on the immediately described and illustrated figure and this position information is to be transferred to the new position in the event of a change of position.

1 shows a schematic illustration of a cranked bending tool 1. The bending tool 1 comprises a tool body 3, which has at least one tool shaft 4 and a tool head 9. The tool shank 4 is provided for receiving in a receiving shaft 15 on the tool holder 14. The tool head 9 is subsequently formed on the tool shank 4 in the bending direction. As can be seen from FIG. 1, the tool center of gravity 10 lies outside or laterally offset to a vertical symmetry plane 17 of the receiving shaft 15. The eccentric tool center of gravity 10 leads to the formation of a tilting moment 13. In FIG. 1, a situation is shown schematically , in which the bending tool 1 is supported with its tool shank 4 via a moving means 8 in the tool holder 14 in a groove 16. Through this support on the movement means 8, the tilting moment 13 causes the tool body 3 to touch the tool holder 14 at at least one contact position. In the illustrated case, such contact positions can occur between the tool shank surface 7 and an inside 18 of the receiving shaft 15 or between a tool shoulder top 12 and a bottom 19 of the tool holder 14. Likewise, contact positions between the movement means 8 and the groove 16 are formed. When the bending tool 1 is displaced in the longitudinal direction 22, increased wear can occur at these contact positions. It can also be seen from FIG. 1 that at least one clamping groove 6 is formed on the tool shaft 4, which is provided for tensioning the bending tool 1 by means of a clamping or clamping system, not shown.

2 to 5 different embodiments of spacer elements 2 are presented and shown schematically. The spacer elements 2 shown exert a supporting force 23 on at least one surface, such as an inside 18 and / or underside

19, the tool holder 14, whereby a compensation of the tilting moment 13 will be effective. The at least one spacer element 2 comprises, according to the invention, a rolling element 25 which is mounted with a prestressing force 24 and which is arranged on or at least partially inside the tool element 3. The spacer element 2 and / or the rolling element 25 are movably mounted at least in the direction of the pretensioning force 24. The at least one rolling element 25 is at least partially arranged in an outstanding manner relative to a surface adjacent to the at least one rolling element, such as the tool shaft surface 7 or the tool shoulder top 12, of the tool body 3.

In Fig. 2 different arrangements and possible positions of a distant element 2 on and / or within a tool body 3 are shown schematically.

2a, 2b and 2f show exemplary embodiments in which the spacer element 2 transmits the supporting force 23 in the transverse direction 21 to the tool holder 14. The respective spacer elements 2 are arranged on or within the tool shank 4 of the tool body 3. In Fig. 2a, the spacer 2 is arranged in the tool shank 4 such that it is flush with the top 5 of the tool shank 4. In Fig. 2b, the dance element 2 is accommodated within the tool shank 4 in such a way that the top 5 of the tool shank 4 can be formed essentially continuously in the longitudinal direction 22 and transverse direction 21. Analogously, these arrangements are to be transferred to the spacer element 2, which is shown schematically in FIG. 2f as a bending rod 31.

2c, 2d and 2e show examples in which the spacer element 2 is arranged on or inside the tool head 9 or the tool shoulder 11. The support force 23 is applied essentially in or opposite to the bending direction

20. In FIG. 2c, the spacer element 2 is positioned in the tool shoulder 11 in such a way that the at least one rolling element 25 can at least partially protrude the upper side of the tool shoulder. Analogously to this, the arrangement of a spacer element 2 is indicated schematically in FIG. 2d, the spacer element 2 being attached laterally to the tool shoulder 11 by means of a spacer element housing 30 in the transverse direction 21. 2e shows an exemplary embodiment, wherein the spacer element 2 comprises a bending rod 31 and is accommodated within the tool head 9 in such a way that a rolling element 25 can at least partially protrude above the tool shoulder top 12.

The arrangements shown schematically in FIGS. 2a to f can be combined with one another or used individually.

3a and 3b and FIG. 4 show examples of spacer elements 2 in which the at least one rolling element 25 is arranged in a rolling element receptacle 27. The supply of the biasing force 24 can be formed directly between the tool body 3 and the rolling body 27 by, for example, one or more spring elements. The spring elements are exemplified as a coil spring, although plate, Blattfe and the like may be suitable for carrying out the invention. In a Dar position of this direct support of the rolling body receptacle 27 on the tool body 3 is dispensed with, since such an embodiment is easily imaginable for a person skilled in the art. In the following, the description of an adjusting device 26 for the adjustable amount of the preload force 24 is discussed in more detail.

As can be seen in Fig. 3a, the rolling body 25 is rotatably arranged in the rolling body receptacle 27. The application of the support force 23 is carried out by transferring the biasing force 24 to the rolling body receptacle 27. The rolling body receptacle 27 can have at least one limitation element 28. The fastening means 29 shown as screws are connected to the tool body 3 or tool shank 4. The limiting element 28 may have a recess or groove, which allows a limited deflection of the rolling body 27 or the spacer 2 in the direction of the biasing force 24. Be the fastening means 29 thus serves on the one hand as a stop in the transverse direction 21 and projects in the longitudinal and / or transverse direction 22, 21 at least parts of the limiting element 28, whereby the spacer element 2 can be prevented from accidentally falling out. Furthermore is 3a shows an adjusting device 26. The illustrated embodiment of the adjusting device 26 comprises at least one spring element for applying the prestressing force 24, which is formed from, for example, two coil springs and a supporting counter plate. Furthermore, the spring travel of the spring element can be set by, for example, an adjusting screw 47 or the like. Such an adjusting screw 47 can be rotatably mounted in the tool body 3 or the tool shank 4 and configured for easy adjustment of the counter plate, and thus the spring travel. Advantageously, the adjusting device 26 is arranged within the tool shank 4 such that no component emerges from the tool shank surface 7.

With reference to the description of FIGS. 2 and 3a, a further exemplary embodiment is shown schematically in FIG. 3b, the spacer element 2 having two rolling elements 25 arranged next to one another in the longitudinal direction 22. A repetition of the function is dispensed with, in particular with reference to the description of FIG. 3a.

FIG. 4 shows a further and possibly independent embodiment of a spacer element 2, the same reference numerals being used for the same parts as in the previous FIGS. 1 to 3. The mode of operation for applying the supporting force 23 while exerting a predeterminable pretensioning force 24 on the rolling element 25 is analogous to the description of FIGS. 3a and 3b. In Fig. 4a, a spacer 2 is shown ge, which is arranged in a spacer housing 30. The Spacer element housing 30 serves to accommodate the rolling element receptacle 27 of the at least one limiting element 28 and to support the Ver adjusting device 26 with respect to the rolling element receptacle 27. This protects the rolling element receptacle 27 and the Ver adjusting device 26 against contamination and / or mechanical influences from outside , In the selected th representation, two limiting elements 28 are formed in the rolling body receptacle 27 as partially recesses. For this purpose, the spacer element housing 30 has formally complementary passage openings, which are not visible in the sectional view, but nevertheless allow the fastening means 29 to be installed from the outside. The fastening means 29 in turn allow a limited deflection of the rolling body receptacle 27 in the direction of the biasing force 24. This arrangement is particularly space-saving. Likewise, the adjusting device 26 or the adjusting screw 47 is very easy to reach from the outside. The illustrated exemplary embodiments of the spacer element 2 of FIGS. 3a, 3b and FIG. 4 can also be arranged differently in conjunction with FIG. 2 on or at least partially within the tool body 3. On a detailed description of alternative positions and / or combinations of such spacer elements 2 is clearly apparent to those skilled in the art and is therefore not explained in detail.

In Fig. 5, exemplary embodiments are shown schematically, the spacer 2 being designed as a bending rod 31 such that the at least one rolling element 25 is arranged at a free end 32 and a fixed end 33 is normal and / or in the bending direction 20 in the tool head 9 is attached.

In Fig. 5a, the bending rod 31 is screwed ver with a threaded portion 34 in the tool head 9. It is also conceivable that the bending rod 31 is fastened at its fixed end 33 outside the tool head 9. As can be seen in Fig. 5a, the bending rod 31 is deflected when the bending tool 1 is received in the tool holder 14 in the bending direction 20, as indicated schematically by a movement arrow. The stiffness of the bending rod 31 is adjustable by the material and the diameter and / or the bending length 36 of the bending rod 31. When the rolling body 25 comes into contact with the underside 19 of the tool holder 14, the bending rod 31 is bent, as a result of which the prestressing force 24 is applied to the rolling body 25. In order to enable a limited deflection of the free end 32 of the bending rod 31, a receiving opening 46 is provided in the tool body 3. In such an embodiment, the rolling body 25 is thus at least partially movable in the bending direction 20 and / or longitudinal direction 22.

Another possibility for executing a spacer element 2 as a bending rod 31 is shown schematically in FIG. 5b. In the illustration shown, an adjusting device 26 is indicated. The adjusting device 26 corresponding to a bending rod 31 can comprise an adjusting screw 47 which is accessible from the outside and which is used to adjust the support distance

42 between the threaded portion 34 and a transverse to the bending direction 20 movable gela gerte support element 43 is formed. In this way, the available bending length 36 can be adjusted by means of the adjusting device 26, whereby the prestressing force 24 or supporting force 23 can be adjusted. It can also be seen from FIG. 5b that the support element

43 supports the bending section 35 to form a two-point support. Is preferred the support element 43 is formed as a sleeve which at least partially encases the bending rod 31 on a part of the bending section 35.

Furthermore, a further exemplary embodiment can be seen from FIG. 5b, in which the bending rod 31 is designed as a waisted bending rod 31. Here, the bending section 35 is indicated as a first waist section 38 and the rolling body section 37 as a second waist section 39. At least one waist section diameter 40 of the first and / or second waist section 38, 39 is smaller than a thread section diameter 41. Analogous to the description of FIG. 5a, the rigidity of the waisted bending rod 31 can be set relatively easily by the local diameter and / or material etc. of the bending rod 31.

From Fig. 1 to 5, the formation of at least one movement means 8 he is visible, which is at least on one side on the tool shank 4 relative to a respective tool shaft surface 7 is excellent. Such movement means 8 serve for receiving in a groove 16 of the tool holder 14 and enable movement of the bending tool 1 in the longitudinal direction 22. It has proven to be particularly advantageous to design at least two movement means 8 in the longitudinal direction 22 next to one another as a sliding element 44 or rolling element 45. Such a sliding element 44 is preferably connected as an elongated sliding body to the tool shaft 4 and arranged at least on the side of the bending tool on which the center of gravity 10 is mounted. Analogously, the at least one movement means 8 can be designed as a rolling element 45. Schematic representations for this are shown in FIGS. 1 to 5.

In a further embodiment, at least two movement means 8 are formed in the transverse direction 21 on opposite sides of the tool shank 4, as can be seen from the combination and discussions of FIGS. 1 to 5 can be derived easily.

In a special embodiment, the movement means 8 or sliding element 44 can also be designed as an integral extension of the tool shank 4 and thus be produced in one piece with the tool shank 4. Such movement means can preferably have a greater extension in the longitudinal direction 22 than in the bending direction 20, which makes a good Load transfer can be achieved. A designed as an extension of the tool shank 4 moving means 8 is preferably provided with a surface layer, not shown, with a low coefficient of friction.

6 and 7, a further and possibly independent embodiment of a cranked bending tool 1 is shown, again using the same reference numerals for the same parts as in the previous FIGS. 1 to 5. Be previous parts of the description are transferable to the same parts with the same reference numerals. Due to its relatively large catch extension, this bending tool 1 comprises a total of three spaced-apart movement means 8, which are held on or in the tool shank 4. Each of these movement means 8 each has a rolling pin 48, which is preferably formed in one piece and passes through the tool shank 4 in the transverse direction 21 via a receiving bore 50. This bore 50 is continuously cylindrical and thus easy to manufacture. The rolling pin 48 is freely rotatable relative to the tool shank 4 by at least one rotary bearing element 49, preferably by two axially spaced rotary bearing elements 49. The at least one rotary bearing element 49 is preferably formed by a slide bearing element 51, but can alternatively also be formed by a roller bearing element, in particular by a cylindrical roller bearing or needle bearing. The preferably executed in pairs rotary bearing elements 49 can be pressed into the receiving bore 50 and / or glued. A holding flange 48 'arranged on such a pair of rotary bearing elements 49 on the rolling pin 48 can act in an advantageous manner as an axial securing device for the rotatably mounted rolling pin 48.

The mutually opposite end sections 52, 53 of the roller pin 48 each protrude from the tool shaft surfaces 7 and can thus roll in grooves 16 (FIG. 1) of the receiving shaft 15 of a tool holder 14 when the bending tool 1 is received in the tool holder 14 in a load-bearing manner, but therein is not clamped, son is held displaceably in the direction of capture 22. Only when necessary, activation of a known clamping device on or in the tool holder 14 (FIG. 1) does the at least one bending tool 1 be held or clamped in a fixed position and generally with its at least one tool shoulder top 12 against the at least one side formed bottom 19 of the tool holder 14 pushed. Such a clamping device can - as known per se - comprise a plurality of pairs or oppositely arranged wedge-shaped clamping pistons which can interact with the cross-sectionally wedge-shaped or trapezoidal clamping grooves 6 on the tool shank 4.

A spacer element 2 is preferably formed in each case in the region of the longitudinal ends of the bending tool 1, based on the longitudinal direction 22. These spacer elements 2 are designed accordingly to the embodiment according to Lig. 5a or Lig. 5b. To avoid repetition, reference is made to the respective reference numerals and to the preceding descriptive parts.

In FIGS. 8 and 9, a further embodiment of a cranked bending tool 1, which may be independent, is shown, again using the same reference numerals for the same parts as in the previous Lig. 1 to 7. Be previous parts of the description are transferable to the same parts with the same reference numerals. Two spacing elements 2 spaced apart from one another in the longitudinal direction 22 are provided, which are formed on one of the two tool schools 11 or in one of the two tool shoulders 12. Each spacer element 2 has a block or strip-shaped roll body receptacle 27 for the roll body 25 held thereon. The rolling body 25 is cylindrical or roller-shaped and rotatably mounted directly in the rolling body receptacle 27. The rolling element 25 can thus also be referred to as rolling element 54 who the.

The rolling element 54, which is preferably made of metal, in particular steel, is rotatably inserted into a receiving bore 55 which is formed in the rolling element receptacle 27. A rotational or longitudinal axis 56 of the rolling element 54 extends in transverse direction 21 to the bending tool 1. A partial section of the lateral surface of the cylindrical rolling element 54 protrudes from an outer surface 57 of the rolling element receptacle 27. This is accomplished by suitable positioning of the longitudinal axis 56 of the bore 55 relative to the rolling body receptacle 27. An axial length of the rolling element 54 is preferably a multiple of its diameter. The roll body receptacle 27 is arranged partially or in sections within a recess 58, which recess 58 is formed in the at least one tool shoulder 11, or is received in the at least one tool shaft surface 7. The rolling body receptacle 27 is relatively movable by means of wall surfaces of the recess 58, in particular under the action of the biasing force 24 resiliently resilient ge. Preferably, there is a spring-loaded sliding mobility between the Rollkörperauf measure 27 and the recess 58. The corresponding spacer element 2 is thus at least partially, in particular for the most part, integrated in the tool shoulder 11, thereby creating a robust and at the same time cost-optimized design.

The cylindrical rolling element 54 is preferably formed from metal, while the rolling body receptacle 27 can be formed from a different material, in particular from plastic. If necessary, the block-shaped or strip-shaped roll body receptacle 27 can also be formed from a metallic slide bearing material, in particular with brass components.

In order to keep undesired jamming or tilting of the spacer element 2 and subsequently the bending tool 1 in manual and / or automated displacements of the bending tool 1, provision can also be made for the rolling body receptacle 27 to have a run-up slope in at least one of its distal end sections 59 or at least has a convex surface 57 in the central portion thereof. The Endab sections of the rolling body receptacle 27 relate to the longitudinal direction 22 of the bending tool 1 and the bending machine equipped with it.

The exertable by the spacer element 2, resiliently flexible supporting force 23 of the bending tool 1 is provided by the biasing force 24 acting on the rolling body receptacle 27. In the embodiment according to FIG. 9, the pretensioning force 24 acting on the roll body receptacle 27 and the at least one roll body 25 is provided by exactly two spring elements 60, 61 supported on the roll body receptacle 27 by at least two spaced apart in the longitudinal direction 22. These spring elements 60, 61, which can be designed as helical springs, preferably act on the end sections of the rolling body receptacle 27. The rolling element 54 is arranged in the region of the longitudinal center of the rolling element receptacle 27, that is to say in a section between the two Spring elements 60, 61 positioned. As a result, mechanically stable conditions can be achieved for the distance element 2, in particular for the block-shaped or strip-like, resiliently flexible roller bearing seat 27.

As an alternative to the embodiment according to FIG. 9, it is also possible to provide two rotatably mounted rolling bodies 54 on the rolling body receptacle 27, as is illustrated by way of example in FIG. 10. The two cylindrical rolling elements 54 are each arranged in the region of the longitudinal ends of the rolling element receptacle 27, while the limiting element 28 is positioned in the central portion thereof. In particular, here only a single fastening means 29 is provided, with which the spacer element 2 or its roll body is captively fastened or fastened to the bending tool 1. This fastening means 29, in particular a single screw, can be used starting from the factory tool shoulder top 12 in a central bore in the rolling body receptacle 27, whereby a quick and easy installation or maintenance of this spacer element 2 can be achieved bar.

As can best be seen from FIG. 7, the at least one rolling element 25 can have a rolling surface 62 that increases friction with respect to metallic surfaces, in particular made of a plastic, preferably of an elastomeric plastic. The rolling body 25 may be coated on its rolling surface accordingly, or may be formed for the most part from a corresponding plastic. This can be useful in particular when designing the spacer element 2 in combination with a cantilevered bending rod 31.

The exemplary embodiments show possible design variants, it being noted at this point that the invention is not restricted to the specially illustrated design variants of the same, but rather also various combinations of the individual design variants with one another are possible and this variation possibility is based on the teaching of the technical Acting through the subject invention lies in the ability of the person skilled in the art in this technical field. The scope of protection is determined by the claims. However, the description and drawings are to be used to interpret the claims. Individual features or combinations of features from the different exemplary embodiments shown and described can represent independent inventive solutions. The task underlying the independent inventive solutions can be found in the description of who.

All information on value ranges in the present description is to be understood in such a way that it includes any and all sub-areas from it, for example, the information 1 to 10 is to be understood such that all sub-areas, starting from the lower limit 1 and the upper limit 10, are included are, ie all sub-areas begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10. The order For the sake of convenience, it should finally be pointed out that, for a better understanding of the structure, elements have been shown sometimes to scale and / or enlarged and / or reduced.

B e z u g s z e i c h e n a u f s t e l l u n g Bending tool 31 Bending bar

Spacer 32 free end

Tool body 33 fixed end

Tool shank 34 threaded section

Top of the tool shank 35 bending section

Clamping groove 36 bending length

Tool shaft surface 37 Rollkörperab section

Movement means 38 first waist section

Tool head 39 second waist section Tool center of gravity 40 Waist section diameter Tool shoulder 41 Thread section diameter Tool shoulder top 42 Support spacing

Tilting moment 43 support element

Tool holder 44 sliding element

Receiving shaft 45 rolling element

Groove 46 receiving opening

Plane of symmetry 47 adjusting screw

Inside of the receiving shaft 48 rolling pin

Underside of the tool holder 48 'holding flange

Bending direction 49 Pivoting element transverse direction 50 Location hole

Longitudinal direction 51 plain bearing element

Supporting force 52 end section

Preload 53 end section

Rolling element 54 cylindrical roller adjusting device 55 bore

Roll body mount 56 longitudinal axis

Boundary element 57 surface

Fastening means 58 recess

Spacer housing 59 Sloping start Spring element spring element roll-off surface

Claims

P a t e n t a n s r u c h e

1. cranked bending tool (1) for a bending machine, in particular a die bending machine, comprising

- A tool body (3) which has at least one tool shank (4) for at least partially receiving the bending tool (1) in a bending direction (20) in a receiving shaft (15) provided therefor, one on the tool shank (4) in the bending direction (20) then has a tool head (9) which has a tool center of gravity (10) outside a vertical plane of symmetry (17) of the receiving shaft (15) and has a tool shoulder (11) at least on one side in a transverse direction (21),

- And at least one on the tool shaft (4) for moving the bending tool (1) in the longitudinal direction (22) of the bending machine for receiving in a groove (16) provided movement means (8), which at least on one side on the tool shaft (4) relative to a respective tool shank surface (7) is excellently designed,

- And at least one spacer element, for applying a counteracting supporting force (23) to at least one surface (18, 19) of the tilting moment (13) caused by deviation of the tool center of gravity (10) from the plane of symmetry (17) in the transverse direction (21) Tool holder (14),

characterized in that

the at least one spacer element (2) comprises at least one roller body (25) mounted with a preload force (24), which is movably mounted on or at least partially within the tool body (3) at least in the direction of the preload force (24) and at least at least partially outstandingly arranged relative to a surface of the tool body (3), preferably adjacent to the at least one rolling body (25).

2. cranked bending tool (1) according to claim 1, characterized in that the at least one rolling element (25) for applying the supporting force (23), normal to the bending direction (20) or transverse direction (21) on an inside (18) of the receiving shaft (15) and / o which is arranged in the bending direction (20) on an underside (19) of the tool holder (14), on and / or at least partially in the tool body (3).

3. cranked bending tool (1) according to one of the preceding claims, characterized in that the at least one spacer element (2) a Ver adjusting device

(26) to adjust the amount of biasing force (24).

4. cranked bending tool (1) according to one of the preceding claims, characterized in that the spacer element (2) comprises at least two rolling elements (25), which are preferably arranged side by side in a rolling element holder (27).

5. cranked bending tool (1) according to any one of the preceding claims, characterized in that the at least one spacer element (2) comprises a rolling element receptacle (27) and at least one limiting element (28), which limiting element (28) for limiting a deflection of the rolling element receptacle (27) or the Rollkör pers (25) by at least one fastening means (29) with the tool body (3) in the direction of the biasing force (24) is movably connected.

6. cranked bending tool (1) according to one of the preceding claims, characterized in that the at least one spacer element (2) is arranged in a distant element housing (30), which at least for receiving the rolling body receptacle

(27) and the at least one limiting element (28), and for supporting the adjusting device (26) with respect to the rolling body receptacle (27).

7. cranked bending tool (1) according to claim 6, characterized in that the at least one spacer element (2) on the outside of the tool head (9) for supporting the bending tool (1) on the underside (19) of the tool holder (14) is arranged.

8. cranked bending tool (1) according to one of claims 1 to 5, characterized in that the spacer element (2) is designed as a bending rod (31) such that the at least one rolling element (25) at a free end (32) of the bending rod (31) is arranged and a fixed end (33) of the bending rod (31) normal to the bending direction (20) and / or in the bending direction (20) in the tool body (3), preferably tool head (9), is attached.

9. cranked bending tool (1) according to claim 8, characterized in that the at least one rolling body (25) is at least partially arranged opposite to a tool shoulder top (12) and the rolling body (25) for applying the supporting force (23) in the bending direction (20) opposite the tool holder (14) with the fixed end (33) of the bending rod (31) normal to the bending direction (20) in the tool head (9).

10. cranked bending tool (1) according to one of claims 8 or 9, characterized in that the bending rod (31) at least one threaded portion (34) for receiving the bending rod (31) in the tool head (9) and / or tool shank (4) , comprises a bending section (35) with a predeterminable bending length (36) and a rolling body section (37), and the adjusting device (26) for adjusting the pretensioning force (24) by adjusting a predeterminable support distance (42) between the threaded section (34) and Rollkörperab section (37), the bending section (35) is arranged at least partially supporting.

11. cranked bending tool (1) according to one of claims 8 to 10, characterized in that the bending rod (31) is designed as a waisted bending rod (31), the bending section (35) as a first waist section (38) and the rolling body section ( 37) is designed as a second waist section (39) and at least one waist section diameter (40) of the first and / or second waist section (38, 39) is smaller than a threaded section diameter (41).

12. cranked bending tool (1) according to one of claims 8 to 11, characterized in that the Ver adjusting device (26) for adjusting a predeterminable Ab Stützab stand (42), the bending section (35) at least partially encased, preferably sleeve-shaped support element (43).

13. cranked bending tool (1) according to any one of the preceding claims, characterized in that at least two movement means (8) in the longitudinal direction (22) ne side by side as a sliding element (44) or preferably as a rolling element (45) are formed.

14. cranked bending tool (1) according to one of the preceding claims, characterized in that at least two movement means (8) in the transverse direction (21) opposite sides of the tool shank (4), preferably symmetrically opposite lying, are formed.

15. cranked bending tool (1) according to one of the preceding claims, characterized in that the at least one movement means (8) is formed in one piece with the tool shaft (4) as an extension.

16. cranked bending tool (1) according to one of claims 1 to 14, characterized in that the at least one movement means (8) comprises a rolling pin (48), which cher rolling pin (48) by means of at least one rotary bearing element (49) within the factory Tool shank (4) is rotatably mounted relative to the tool body (3).

17. cranked bending tool (1) according to claim 16, characterized in that the at least one rotary bearing element (49) is formed by at least one in a receiving bore (50) of the tool shaft (4) held slide bearing element (51) or roller bearing element.

18. cranked bending tool (1) according to claim 16 or 17, characterized in that the at least one rolling pin (48) is formed in one piece and thereby the tool shaft (4) with the interposition of the at least one rotary bearing element (49) penetrates such that its mutually opposite end portions (52, 53) protrude relative to the opposite tool shaft surfaces (7).

19. The cranked bending tool (1) according to one of the preceding claims, characterized in that the at least one spacer element (2) comprises a rolling element receptacle (27), in which rolling element receptacle (27) at least one rolling element (25) designed as a cylindrical rolling element (54) ) is rotatably mounted.

20. Angled bending tool (1) according to claim 19, characterized in that the at least one cylindrical rolling element (54) is held in at least one bore (55) formed in the rolling element receptacle (27), a longitudinal axis (56) of the at least least a bore (55) is positioned such that a portion of the lateral surface of the cylindrical rolling element (54) protrudes from an outer surface (57) of the rolling element holder (27).

21. The cranked bending tool (1) according to claim 19 or 20, characterized in that the rolling body receptacle (27) is accommodated in sections within a recess (58) in the at least one tool shoulder (11) or the at least one tool shaft surface (7) is and is resiliently resilient relative to this recess (58) by applying the pre-tensioning force (24).

22. cranked bending tool (1) according to one of claims 19 to 21, characterized in that the rolling body receptacle (27) in at least one of its longitudinal sections (22) related end sections a run-up slope (59) or at least in the middle section has a convex surface (57).

23 cranked bending tool (1) according to any one of claims 19 to 22, characterized in that the at least one cylindrical rolling element (54) is made of metal and the rolling body receptacle (27) is made of a different material, in particular plastic ,

24. The cranked bending tool (1) according to one of the preceding claims, characterized in that the prestressing force (24) acting on the rolling body receptacle (27) and the at least one rolling body (25) is spaced apart from one another by at least two in the longitudinal direction (22) Rolling element receptacle (27) acting spring elements (60, 61) is provided.

25. cranked bending tool (1) according to one of the preceding claims, characterized in that the at least one rolling element (25) has a rolling-surface surface (62) which increases friction with respect to metallic surfaces, in particular made of a plastic, preferably of an elastomeric plastic, having.