EP3858512B1 - Folding device for folding a sheet metal assembly - Google Patents

Description

The invention relates to a folding device.

A folding device is, for example, from DE 10 2015 220 540 A1 known and provided for folding a sheet metal assembly of a vehicle body. In the case of such a fold processing, a linear joint at the edge between different sheet metal components of the sheet metal assembly is produced in a manner which is known in principle. The known folding device has a folding bed, on the upper side of which a folding bed contour is formed, which accommodates at least one of the sheet metal components in a positioning manner. The folding device also has a base frame, referred to as the base, on which the folding bed is supported.

More folding devices are also from the WO 2016/152968 A1 and the EP 3 479 920 A1 known. The folding devices shown there each have a support device with several supports, by means of which the folding bed is supported on the base frame. The supports can each be placed against the folding bed from below. This is intended to improve the support of the folding bed on the base frame.

In any case, in the area of car body production, it is common practice for the folding bed contour to be shaped in accordance with a desired target geometry of the sheet metal component to be accommodated on it. This target geometry is usually also referred to as the zero geometry.

Furthermore, it is generally known that in the case of individual drawing production of sheet metal components, springback-related dimensional and shape deviations from the zero geometry can occur. Such springback-related deviations at the level of the individual sheet metal components can lead to problems during seam processing and ultimately to dimensional and shape deviations of the sheet metal assembly assembled from the different sheet metal components by means of the seam processing.

Measures to improve the dimensional and shape accuracy of the sheet metal assembly usually start at the level of individual part production. For this purpose, for example, the drawing tools used in the production of individual parts can be geometrically adjusted using basically known methods to correct the deviations in the sheet metal components caused by springback. This is time-consuming and costly.

The object of the invention is to provide a hemming device of the type mentioned at the outset, which enables improved hemming of the sheet metal assembly with regard to dimensional and shape accuracy that can be achieved.

This object is achieved by providing a folding device with the features of claim 1. The solution according to the invention enables a correction of any dimensional and/or shape deviations caused by springback starting at the level of the fold processing. In this way, in particular, a time-consuming and costly correction at the level of the individual part production of the sheet metal assembly can be avoided. In addition, with the solution according to the invention, an assembly that is intrinsically accurate in terms of dimensions and shape can be adapted to an adjacent assembly in order to obtain an improved joint quality when the assemblies are brought together. Such a procedure can be considered, for example, if it would be significantly more expensive to adapt the neighboring assembly. The correction is made by adjusting the folding bed contour, which can also be referred to as a geometric change or geometric adjustment of the folding bed contour. The fold bed contour can be adjusted, for example, with the aim of improving the mounting and/or positioning of the sheet metal component to its actual geometry. The folding bed contour is preferably set in accordance with a setting specification that is not described in detail in the context of this application and that can be created, for example, on the basis of empirical values, measured values and/or simulation results. The folding bed contour is adjusted by means of a targeted elastic and/or elastic-plastic deformation of the folding bed, with the at least one adjusting device being provided for this purpose according to the invention. The folding bed is deformed under the action of the at least one adjusting element of the adjusting device, which for this purpose engages the underside of the folding bed in a force-transmitting manner and can be displaced between the different adjusting positions relative to the base frame. As a result, the folding bed can be deformed as a function of the adjustment movement of the at least one adjustment element. As a result, the folding bed assumes a first state of deformation, for example in a first setting position of the setting element, and assumes a second state of deformation in a second setting position of the at least one setting element. Depending on the state of deformation of the folding bed, the folding bed contour formed on the upper side of the folding bed changes, as a result of which the said adjustability is ultimately achieved. The folding bed is preferably made of steel or cast iron. Preferably, the folding bed--in the sense of a rigid-body movement--is fastened to the base frame, at least indirectly, so that it cannot be displaced relative to it. Said deformation of the folding bed is therefore not to be confused with a rigid-body movement of the folding bed relative to the base frame, in which a translatory and/or rotational displacement of the entire folding bed takes place. The folding bed contour is formed on the upper side of the folding bed and is used for positioning the at least one sheet metal component of the sheet metal assembly. The folding bed contour can in particular also be referred to as the active surface. In a non-deformed state of the folding bed, the folding bed contour preferably corresponds to the zero geometry of the sheet metal component to be picked up. The folding bed contour is therefore preferably manufactured according to the desired zero geometry of the sheet metal component and can be geometrically adapted, ie adjusted, starting from this zero geometry. The base frame is used for load-bearing support of the folding bed and the at least one adjustment device and, if necessary, other components and/or sections of the folding device. The base frame can be manufactured in particular as a cast component or steel plate construction. The at least one adjusting element is supported at least indirectly on the base frame and at the other end at least indirectly on the underside of the folding bed, preferably firmly attached to the same. The adjusting element can be adjusted in a translatory and/or rotary manner. The adjustment mobility can be provided along and/or around at least one adjustment axis. Depending on the direction of the adjusting movement, the adjusting movement of the at least one adjusting element causes a tensile and/or compressive force to be applied to the folding bed, as a result of which said deformation is brought about. In other words, as a result of such an application of force, the folding bed is pressed upwards and/or pulled downwards at least locally, namely in the area of the folding bed in which the at least one adjusting element acts. Depending on the direction and/or extent of the adjustment movement, different states of deformation and thus folding bed contours can be set as a result.

Furthermore, according to the invention, the at least one adjusting element acts on the underside of the folding bed in a manner that transmits compressive force and tensile force. Accordingly, force is not transmitted for the purpose of deforming the folding bed in just one direction of the adjustment movement. Rather, the folding bed can be both pushed and pulled under the action of the at least one adjusting element.

In a further embodiment of the invention, the at least one adjusting element can be adjusted in a translatory manner at least along an adjusting axis. Such a translational adjustment mobility can be implemented with structurally simple and robust means. The at least one adjustment axis can in particular be aligned perpendicularly or at an angle to the underside and/or the contour of the folding bed.

In a further embodiment of the invention, the at least one adjustment axis is aligned coaxially to a normal direction of the folding bed contour. The inventors have recognized that by a such alignment of the at least one adjustment axis, a particularly advantageous adjustability of the folding bed contour can be achieved. If several adjusting elements act at different points on the underside of the folding bed, these are preferably each aligned coaxially to the normal direction of the folding bed contour at the respective point.

In a further embodiment of the invention, the at least one adjustment device has at least one joint bearing, by means of which the at least one adjusting element is mounted in an articulated manner about at least one joint axis relative to the base frame. The at least one joint bearing counteracts an unwanted state of tension between the base frame and the folding bed. Due to the articulated mounting of the at least one adjusting element, the adjusting element--in terms of an orientation of the adjusting movement--can be tracked as it were to the deformation state of the folding bed that is set, whereby the said tension states are avoided. Such states of tension can have a negative effect on the achievable quality of setting the folding bed contour. The at least one joint axis is preferably aligned perpendicular to the adjustment movement of the at least one adjustment element.

In a further embodiment of the invention, the at least one joint bearing is designed as a ball joint bearing and allows spatial joint mobility of the at least one actuating element. Such a ball joint bearing has a ball-like joint head which interacts with a spherical cap-shaped joint socket. With this configuration of the invention, the above-described undesired tension states can be avoided in a further improved manner. A bearing arrangement is preferably provided which allows both the adjustment mobility and the joint mobility of the at least one adjustment element in a combined manner. Such a bearing arrangement can in particular be designed as a spherical axial bearing, or at least have such a spherical axial bearing.

In a further embodiment of the invention, the at least one adjustment device has a bearing housing which is fixedly connected to the base frame and in which the at least one adjustment element is mounted in an adjustable and/or articulated manner. This enables a particularly simple design and assembly. This is because the at least one adjusting element is not mounted directly on the base frame so that it can be adjusted and/or articulated. Instead, the bearing housing is provided for this purpose. The bearing housing is preferably attached to the base frame by means of at least one screw connection.

In a further embodiment of the invention, the at least one adjusting element is an adjusting cylinder that can be screwed between the different adjusting positions. One end of the actuating cylinder acts on the underside of the folding bed. On a region of the actuating cylinder facing away from the folding bed, the latter is mounted in a screw-movable manner on the base frame or in the bearing housing, if one is provided. The positioning movement of the positioning cylinder takes place along its longitudinal axis and thus in the axial direction. With this embodiment of the invention, a structurally simple and particularly robust design can be achieved.

In a further embodiment of the invention, several adjustment devices, in particular structurally identical, are provided, with the adjusting elements of the several adjusting devices acting on different areas of the underside of the folding bed and being adjustable independently of one another. This refinement of the invention makes it possible to achieve improved adjustability of the folding bed contour. This is because the several adjusting elements act on the different areas of the underside, so that the folding bed cannot only be deformed “locally” in one area, but rather “regionally” and/or “globally”. In other words, significantly more different deformation states and thus folding bed contours can be set in comparison to a setting with only one setting device. In this case, each control element forms a “degree of freedom” of adjustability, so to speak. Preferably, the multiple adjustment devices are of identical design, which means that the construction of the folding device can be simplified even further and that it can be constructed in a particularly cost-effective manner.

In a further embodiment of the invention, the folding bed is supported on the base frame exclusively via the multiple adjustment devices. In this embodiment of the invention, additional load-bearing components for supporting the folding bed on the base frame can be dispensed with. Rather, the folding bed is supported solely by the multiple adjustment devices. As a result, a particularly simple construction can be achieved.

In a further embodiment of the invention, the folding bed and the adjustability of the at least one adjusting element are dimensioned in a coordinated manner, so that in the different adjusting positions of the at least one adjusting element an at least largely, preferably completely, reversible deformation of the folding bed is achieved. In principle, the deformations of the folding bed caused by the action of the at least one adjusting element can be elastic and/or elastic-plastic, with this embodiment of the invention providing an at least largely elastic, preferably completely elastic, deformation. For this purpose, the Falzbett are in terms of its flexibility on the one hand and on the other the extent of Adjustability constructively coordinated. This prevents plastic deformation of the folding bed from occurring during a maximum adjustment movement. As a result of such plastic deformations, the folding bed contour can practically only be adjusted once. In addition, plastic deformations of the folding bed contour can lead to a development length of the folding bed contour and a development length of the sheet metal component to be accommodated no longer matching, which can be regarded as fundamentally problematic. Since in this embodiment of the invention an at least largely, preferably completely, reversible deformation of the folding bed is achieved, the folding bed contour can accordingly be adjusted several times and in different ways, if this should be necessary. The coordinated dimensioning of the folding bed and the adjustability can take place, for example, on the basis of empirical values, measured values and/or simulation results. It goes without saying that the structural design of the folding bed also takes into account the process forces occurring during folding. In this regard, it is desirable that the deformations of the folding bed that occur during folding are as small as possible. Nevertheless, there should be sufficient flexibility in shape for the desired adjustability. Accordingly, a type of compromise and/or an optimum must be found here—for example on the basis of the empirical values, measured values and/or simulation results mentioned.

In a further embodiment of the invention, the folding bed has at least one defined weakening, by means of which—compared to an imaginary unweakened state—an increased flexibility of the folding bed is achieved under the action of the at least one adjusting element. Due to the increased dimensional flexibility of the folding bed, the same can be deformed into the different deformation states under the influence of comparatively lower actuating forces of the at least one actuating element. As a result, the construction can be designed to be less massive and thus save material, which ultimately means that costs can be saved. The at least one weakening can be due to the material and/or design. The at least one weakening can be designed, for example, in the form of a bore, recess, notch, cross-sectional reduction or the like.

In a further embodiment of the invention, a hold-down device arranged above the folding bed is provided, which has a hold-down frame supported on the base frame and a plurality of hold-down elements which are provided for holding down the sheet metal assembly and are attached to the hold-down frame, the hold-down elements being moved relative to each other by means of a guide element between different fastening positions are led to the hold-down frame. The function and the basic structure of such a hold-down device are the prior art as such known. However, in this embodiment of the invention it is provided that the hold-down elements can be fastened in different positions on the hold-down frame in a manner coordinated with the folding bed contour set by means of the at least one adjustment device. For this purpose, a guide element is assigned to each hold-down element. The respective hold-down element is guided between the different fastening positions by means of the guide element. The guide elements can each be designed in particular in the form of a guide groove, a slotted hole or the like.

The invention also relates to a method with the features of claim 13.

Fig. 1

zeigt in schematischer Perspektivdarstellung eine Ausführungsform einer erfindungsgemäßen Falzvorrichtung,

Fig. 2

die Falzvorrichtung nach Fig. 1 in einer perspektivischen Explosionsdarstellung unter zeichnerischer Ausblendung einzelner Bauteile und/oder Abschnitte,

Fig. 3

in perspektivischer Detaildarstellung ein Falzbett der Falzvorrichtung nach den Fig. 1 und 2, wobei das Falzbett zwei unterschiedliche Deformationszustände einnimmt, die zeichnerisch überlagert und skaliert dargestellt sind,

Fig. 4

eine vergrößerte Detaildarstellung des Falzbetts nach Fig. 3 im Bereich einer mechanischen Schwächung,

Fig. 5, 6

jeweils in einer schematischen Längsschnittdarstellung eine Einstelleinrichtung der Falzvorrichtung nach den Fig. 1 und 2 mit einem stell- und gelenkbeweglichen Stellelement, wobei das Stellelement unterschiedlich gelenkbeweglich verlagert ist, und

Fig. 7

die Falzbettvorrichtung nach den Fig. 1 und 2 in einer weiteren schematischen Perspektivdarstellung unter zeichnerischer Ausblendung einzelner Bauteile und/oder Abschnitte, wobei eine oberhalb des Falzbetts angeordneten Niederhaltereinrichtung vorgesehen ist.

Further advantages and features of the invention emerge from the claims and from the following description of a preferred exemplary embodiment of the invention, which is illustrated with the aid of the drawings.

1

shows a schematic perspective view of an embodiment of a folding device according to the invention,

2

the folding device 1 in a perspective exploded view with graphic blanking out of individual components and/or sections,

3

in a perspective detail view of a folding bed of the folding device according to the 1 and 2 , whereby the folding bed assumes two different states of deformation, which are superimposed and scaled in the drawing,

4

an enlarged detail view of the folding bed 3 in the area of a mechanical weakening,

Figures 5, 6

each in a schematic longitudinal sectional view of an adjusting device of the folding device according to 1 and 2 with an adjusting and articulated adjusting element, wherein the adjusting element is shifted articulated differently, and

7

the folding bed device according to 1 and 2 in a further schematic perspective view with graphic blanking out of individual components and/or sections, a hold-down device arranged above the folding bed being provided.

According to 1 a hemming device 1 is provided for hemming a sheet metal assembly, not shown in the drawing, of a vehicle body and has a folding bed 2, which is supported on a base frame 3 in a manner that will be described in more detail below. The sheet metal assembly is, for example, a hood or a vehicle door. The folding bed 2 has a top O and a bottom U ( 2 , 3 ). A folding bed contour K is formed on the upper side O of the folding bed 2 . For the fold processing of the sheet metal assembly—as is usual in the prior art—a sheet metal component of the sheet metal assembly called the outer part is first placed on the upper side O of the fold bed 2 . In a further step referred to as “boxing”, another sheet metal component, which can be referred to as the inner part, is placed on the outer part that is already positioned on the folding bed 2 . In a further step, the inner part is held down by means of a hold-down device N (cf. 7 ) fixed in a manner known in principle, with the hold-down device N not necessarily having to be part of the folding device 1 in the present case. After this, the outer part and the inner part are joined together in a linear manner at the edge by means of folding. Methods suitable for this are well known in the prior art and are therefore not described in detail at this point.

Furthermore, the folding device 1 has at least one adjustment device 4 assigned to the folding bed contour K. The at least one adjusting device 4 is supported on the base frame 3 and has at least one adjusting element 5 . The at least one adjusting element 5 can be adjusted between different adjusting positions relative to the base frame 3 and acts on the underside U of the folding bed 2 in a force-transmitting manner. As a result, the folding bed 2 can be deformed into different deformation states D1, D2 for setting the folding bed contour K by means of an adjusting movement of the at least one adjusting element 5 (cf. 3 ).

In the embodiment shown, a plurality of adjustment devices 4 are provided, each with an actuating element 5, with such a configuration not being mandatory. In an embodiment that is not shown, only one setting device, a smaller or a greater number than the number of setting devices 4 shown here can be provided instead.

through the basis 3 Illustrated deformation of the folding bed 2 under the action of the at least one adjusting device 4, the folding bed contour K can be adjusted, ie the geometry of the folding bed contour K is changed and/or adjusted. An adjusting movement of the at least one adjusting element 5 that is necessary for this setting of the folding bed contour K preferably takes place according to a predetermined setting specification, which can be based on empirical values, measured values and/or simulation results. By setting the Folding bed contour K, improved dimensional and/or shape stability of the sheet metal assembly can be achieved.

In the embodiment shown, a total of 27 identical adjustment devices 4 are provided. To avoid repetition, the specific design selected here and the functioning of the adjustment devices 4 are only based on the figure 5 and 6 described in detail visible adjustment device 4. The other adjustment devices 4 have a corresponding design.

In the present embodiment, the adjustment device 4 has a bearing housing 6 which is firmly connected to the base frame 3 . For this purpose, the bearing housing 6 is firmly joined to an unspecified upper side of the base frame 3 by means of a plurality of screw connections S. The bearing housing 6 has a pot-shaped basic shape with a circumferential flange 7 at the edge, which is provided with through bores, not designated in any more detail, for the said screw connections S.

The actuating element 5 is movably mounted in the bearing housing 6 in a manner that will be described in more detail below. The adjusting element 5 can be adjusted relative to the base frame 3 along an adjusting axis 8 in a translatory manner between the different adjusting positions. The adjusting axis 8 is oriented coaxially to a longitudinal axis (not designated in more detail) of the adjusting element 5 , which is designed as an adjusting cylinder 9 in the embodiment shown. The actuating cylinder 9 engages at its end region 10 facing the folding bed 2 in a force-transmitting manner on the underside U of the folding bed crown 2 . In the embodiment shown, it is provided that the actuating element 5 or the actuating cylinder 9 acts on the underside U in a manner that transmits both tensile force and compressive force. For this purpose, a screw connection between the adjusting element 5 and the folding bed 2 is provided here. For this purpose, the folding bed 2 has at least one threaded hole 11 on its underside U ( 4 ), into which the front end area 10 of the actuating element 5 is screwed. For this purpose, the front end region 10 is provided with a thread G which is complementary to the threaded bore 11 . In the embodiment shown, the folding bed 2 has a number of threaded holes 11 corresponding to the total number of adjusting elements 5 provided ( 3 ). To fix the adjusting element 5, for example, a lock nut can be screwed onto the thread G, which is locked on the underside U after the folding bed contour K has been set. Alternatively, the front end area 10 can be welded to the underside U.

To set the folding bed contour K, the adjusting element 5 is displaced along the adjusting axis 8, as a result of which the folding bed 2 is subjected to pressure or tension under the action of the adjusting element 5 becomes. Accordingly, the folding bed 2 is pushed upwards or pulled downwards along the actuating axis 8 in the region of the respective force application of the actuating element 5 and is thereby deformed at least locally elastically and/or elastically-plastically. The based 3 The different states of deformation D1, D2 illustrated by way of example are accordingly achieved by a different and coordinated infeed of the plurality of adjusting elements 5. In this case, a stepless adjustment of the different states of deformation is possible through the respective screw-movable displaceability of the actuating elements 5, so that - unlike 3 possibly suggests - any number of different deformation states and not just the exemplary deformation states D1, D2 can be set.

With such an adjustment of the folding bed contour K, it is advantageous if a type of fixed point is defined at which the folding bed 2 is firmly positioned relative to the base frame 3 . Such a fixed point can be formed, for example, by the folding bed 2 being firmly connected to the base frame 3 at at least one point. In the embodiment shown, said fixed point for setting the folding bed contour K is formed by providing a device 4' that is designed differently from the other setting devices 4 ( 1 ). The device 4 ′ as such has a structure which is fundamentally similar to that of the setting devices 4 . However, no adjustability is provided, so that the folding bed 2 is firmly positioned relative to the base frame 3 and is fixed to this extent by means of the device 4′—at the point of application of the device 4′.

For the movable mounting of the actuating element 5 , the setting device 4 has a bearing arrangement L, which is accommodated in a receiving recess 12 in the bearing housing 6 . The bearing arrangement L ensures an axial mounting of the adjusting element 5 for the purpose of adjusting mobility along the adjusting axis 8. At the same time, the bearing arrangement L ensures an articulated pivotable mounting relative to the base frame 3 (cf. figure 5 , 6 ). For this purpose, the bearing arrangement L has a joint bearing in the form of a ball joint bearing 13, 14, 15, 16, which comprises two bearing elements 13, 15 that are spaced apart from one another in the axial direction of the actuating element 5 and are spherically shaped and two bearing shells 14, 16 that are designed to complement them. The bearing shells 14, 16 are fitted into a cylindrical bearing bushing 17 in the radial direction and are arranged at opposite ends of the same. The bearing bush 17 is held in the receiving recess 12 in the axial direction. The bearing bushing 17 is held in the bearing housing 6 so that it can move to a limited extent in the radial direction of the receiving recess 12 . Accordingly, the actuating element 5 is mounted in the bearing housing 6 so that it can move to a limited extent in the radial direction by means of the bearing arrangement L. As a result of this radially movable Storage are both the adjusting axis 8 and the unspecified pivot axis or the spatial pivot axes of the ball joint bearing 13, 14, 15, 16 in the radial direction relative to the bearing housing 6 - and thus relative to the base frame 3 - limited mobility. The actuating element 5 has a circular-cylindrical bearing section 18 which is arranged approximately centrally in relation to its longitudinal extension and on the outer circumference of which the bearing elements 13, 15 are fixed radially, with the bearing section 18 and thus the actuating element 5 being able to slide in the bearing elements in relation to the actuating axis 8 13, 15 is guided. In addition, a spacer bushing 19 is provided, which is arranged between the bearing elements 13, 15 in the axial direction. The thread G arranged at one end interacts with a first threaded nut 20 and a second threaded nut 21 for the adjusting mobility of the adjusting element 5 . In addition, the adjusting element 5 is provided with a further thread G′ on a lower end region 25 facing away from the folding bed 2 , which thread interacts with a third threaded nut 22 and a fourth threaded nut 23 . In the axial direction between the second nut 21 and the - with respect to the plane of the figure 5 - Upper bearing element 13 is an upper spacer sleeve 24 is arranged. Accordingly, a lower spacer sleeve 26 is arranged between the third threaded nut 22 and the lower bearing element 15 .

Starting from the basis figure 5 For the purpose of setting the folding bed contour K, the adjustability of the adjusting element 5 for the application of tensile and compressive forces to the folding bed 2 is explained below in the apparent state.

For the application of compressive force, the third threaded nut 22 and the fourth threaded nut 23 are first loosened. After this, the second threaded nut 21 is screw-actuated using a corresponding screwing tool, so that the actuating element 5 is moved upwards along the actuating axis 8 . As a result of this adjustment movement, the front end 10 acts via the threaded hole 11 on the underside U of the folding bed 2, so that the same is locally pressed upwards in the area of the force application point of the adjustment element 5 relative to the base frame 3 and is thus elastically and/or elastically-plastically deformed becomes. As soon as a predetermined setting position of the setting element 5 has been reached, this can be fixed by tightening the third threaded nut 22 and the fourth threaded nut 23 as well as the first threaded nut 20 .

For the application of tensile force, first the first threaded nut 20 and the second threaded nut 21 are loosened. Thereafter, the actuating element 5 is displaced downwards along the actuating axis 8 by actuating the third threaded nut 22 . Accordingly, the folding bed 2 is pulled downwards, as it were, along the adjustment axis 8 by means of the adjustment element 5 and elastically and/or elastically-plastically deformed. The setting position of the setting element 5 assumed here can be fixed by tightening the threaded nuts 20, 21, 23.

Depending on which deformation of the folding bed 2 is required to set the folding bed contour K, such an actuating actuation takes place on only one, several or all of the setting devices 4 provided. The setting devices 4 can be actuated successively and/or repeatedly until the desired deformation state is reached. In this way, a "local", "regional" or "global" deformation of the folding bed 2 is possible.

How to continue with the 1 and 2 As can be seen, the adjusting axes 8 of the adjusting elements 5 are each oriented coaxially to a normal direction of the folding bed contour K. In this case, the folding bed contour K in the present case is not flat, but shaped spatially curved, so that the direction of the normal is locally variable over the extent of the folding bed contour K. Accordingly, there are different alignments of the respective adjustment axes 8.

In the embodiment shown, the underside U is designed at least in sections parallel to the surface of the upper side O, on which in turn the folding bed contour K is formed. Accordingly, the actuating elements 5 act perpendicularly on the underside U at least at a few points. The above-described articulated mounting of the adjusting elements 5 relative to the base frame 3 ensures that the adjusting axes 8 always remain aligned in the direction normal to the folding bed contour K, even in different states of deformation. In other words, the articulated mounting allows the adjusting axis 8 to follow the deformation that occurs. In the embodiment shown, the mounting of the bearing arrangement L, which is movable to a limited extent in the radial direction of the bearing housing 6, simultaneously enables a translatory tracking movement.

How to continue with the 1 and 2 As can be seen, in the embodiment shown, the folding bed 2 is supported on the base frame 3 exclusively by means of the adjustment devices 4 and the device 4'. However, such a design is not mandatory. In an embodiment that is not shown, the folding bed 2 can only be supported in sections by means of one or more adjustment devices 4 in a load-bearing manner on the base frame 3, so that apart from the one or more adjustment devices 4, there is a direct or at least non-adjustable, i.e. rigidly spaced, support for the folding bed 2 the base frame 3 is provided.

It is also provided here that the folding bed 2 and the above-described adjustability of the adjusting elements 5 are dimensioned in a coordinated manner, so that in the different adjusting positions—and thus in the different deformation states D1, D2—there is a purely elastic deformation of the folding bed 2 in each case . As a result, the fold bed contour K is reversible and can thus be adjusted multiple times—without loss of quality in terms of surface quality of the fold contour and/or the sheet metal assembly to be folded. The design dimensioning of the folding bed 2 required for this and the adjustability can be based on empirical values, measured values and/or simulation results.

How further based 4 is shown, the folding bed 2 in the present case has at least one defined mechanical weakening M, which is designed in the present case in the form of a sectional reduction in the cross section of the folding bed 2 . As a result of this weakening M, the folding bed 2 has increased dimensional flexibility under the action of the at least one actuating element 5—compared to an imaginary unweakened state. The design of the weakening M shown here is to be understood as purely exemplary and can differ from this in the embodiments that are not shown.

In the embodiment shown, the folding bed 2 has a design in the manner of a frame that is closed all the way around, but this is not mandatory. The adjusting elements 5 act on the underside U at a distance from one another along a circumferential direction of the frame (not designated in any more detail).

Furthermore, in the embodiment shown, it is provided that the folding bed contour K is manufactured according to a so-called zero geometry of the sheet metal component to be accommodated. Correspondingly, the folding bed contour K—at least in a state that is not deformed by means of the setting devices 4—corresponds to the zero geometry. Based on this zero geometry, the above-described geometric adjustment then takes place, i. H. Setting using the setting devices 4.

In an embodiment that is not shown, the folding bed contour is manufactured in a geometry that deviates from the zero geometry of the sheet metal component to be accommodated and can be set in particular in the direction of the zero geometry by means of the geometric adaptation described above.

In the embodiment shown, the base frame 3 is manufactured as a cast component. In an embodiment not shown, the base frame 3 as a steel plate construction or be made of solid material. The base frame 3 has a number of flange surfaces 27 corresponding to the number of adjustment devices 4 , which are provided for flange connection with the flange 7 of the respective adjustment device 4 . The flange surfaces 27 are oriented parallel to its underside U with respect to an undeformed state of the folding bed 2 . The flange surfaces 27 each have a central through hole 28 which, starting from an upper side of the base frame 3 (not designated in any more detail), opens into a respective lateral recess 29 . The lower front ends 25 of the actuating elements 5 protrude through the through-holes 28 into the recesses 29 in the fully assembled state. As a result, the third threaded nut 22 and the fourth threaded nut 23 in particular are freely accessible and ergonomically accessible with an appropriate screwing tool.

As mentioned at the outset, the folding device 1 in the embodiment shown also has a hold-down device N ( 7 ), which is arranged in a manner known in principle above the folding bed 2 for holding down the sheet metal assembly during the folding process. The hold-down device N has a hold-down frame 30, which is supported by means of a plurality of support arms on centering devices 31 provided for this purpose on the base frame 3, with reference to FIG 7 only one support arm 32 is shown in the drawing. The hold-down device N also has a plurality of hold-down elements 33 which rest on the sheet metal assembly during the fold processing and are arranged spaced apart from one another along a circumferential direction of the hold-down frame 30 , which is not designated in any more detail.

The hold-down elements 33 are each fastened to the hold-down frame 30, in the present case each of the hold-down elements 33 being assigned a guide element in the form of an angle plate 34 provided with elongated holes. The angle plates 34 are screwed at one end to the hold-down element 33 in question. At the other end, the angle plates 34 are screwed to the hold-down frame 30 via the slotted holes. As a result, the hold-down elements 33 are each guided in different fastening positions relative to the hold-down frame 30 between different fastening positions. In other words, due to the present design, the hold-down elements 33 can be positioned and attached to the hold-down frame 30 in a way that is matched to the contour K of the folding bed that has been set.

Claims (13)

1. Hemming device (1) for hemming a sheet-metal assembly, having a hemming die (2) on whose upper side (O) a hemming die contour (K) is formed and is intended for receiving at least one sheet-metal component of the sheet-metal assembly, and having a base frame (3) on which the hemming die (2) is supported, wherein at least one adjusting device (4) associated with the hemming die contour (K) is provided which is supported on the base frame (3) and has at least one setting element (5) which is settably movable relative to the base frame (3) between different setting positions and acts in a force-transmitting manner on the underside (U) of the hemming die (2), wherein the hemming die (2) is deformable into different deformation states (D1, D2) for adjustment of the hemming die contour (K) by means of a setting movement of the setting element (5), characterized in that the at least one setting element (5) acts on the underside (U) of the hemming die (2) in a tensile force-transmitting and compressive force-transmitting manner.
2. Hemming device (1) according to claim 1, characterized in that the at least one setting element (5) is settably movable translationally along at least one setting axis (8).
3. Hemming device (1) according to claim 2, characterized in that the at least one setting axis (8) is aligned coaxially with a normal direction of the hemming die contour (K).
4. Hemming device (1) according to any of the preceding claims, characterized in that the at least one adjusting device (4) has at least one pivoting bearing (13, 14, 15, 16) by means of which the at least one setting element (5) is mounted pivotably movable about at least one joint axis relative to the base frame (3).
5. Hemming device (1) according to claim 4, characterized in that the at least one pivoting bearing (13, 14, 15, 16) is designed as a pivoting ball bearing and permits a spatial pivotable movability of the at least one setting element (5).
6. Hemming device (1) according to any of the preceding claims, characterized in that the at least one adjusting device (4) has a bearing housing (6) firmly connected to the base frame (3) and in which the at least one setting element (5) is mounted settably movable and/or pivotably movable.
7. Hemming device (1) according to any of the preceding claims, characterized in that the at least one setting element (5) is a setting cylinder (9) screwably movable between the different setting positions.
8. Hemming device (1) according to any of the preceding claims, characterized in that several in particular identically designed adjusting devices (4) are provided, wherein the setting elements (5) of the several adjusting devices (4) act in different areas on the underside (U) of the hemming die (2) and are settably movable independently of one another.
9. Hemming device (1) according to claim 8, characterized in that the hemming die (2) is supported on the base frame (3) exclusively by the several adjusting devices (4).
10. Hemming device (1) according to any of the preceding claims, characterized in that the hemming die (2) and the settable movability of the at least one setting element (5) are dimensioned in a coordinated way, such that an at least largely and preferably completely reversible deformation of the hemming die (2) is achieved in each of the different setting positions of the at least one setting element (5).
11. Hemming device (1) according to any of the preceding claims, characterized in that the hemming die (2) has at least one defined attenuation (M), by means of which - in comparison to a theoretical unattenuated state - an increased flexibility in shape of the hemming die (2) is achieved under the effect of the at least one setting element (5).
12. Hemming device (1) according to any of the preceding claims, characterized in that a hold-down device (N) arranged above the hemming die (2) is provided that has a hold-down frame (30) supported on the base frame (3) and several hold-down elements 33) provided for holding down the sheet-metal assembly and fastened to the hold-down frame (30), wherein the hold-down elements (33) are each guided relative to the hold-down frame (30) between different fastening positions by means of one guide element (34).
13. Method for setting a hemming die contour (K) of a hemming device (1), wherein the hemming device (1) has a hemming die (2) on whose upper side (O) the hemming die contour (K) is formed and is intended for receiving at least one sheet-metal component, a base frame (3) on which the hemming die (2) is supported, and an adjusting device (4) associated with the hemming die contour (K) which is supported on the base frame (3) and has at least one setting element (5) which is settably movable relative to the base frame (3) between different setting positions along a setting axis (8) and acts on the underside (U) of the hemming die (2) in a tensile force-transmitting and compressive force-transmitting manner, wherein the method includes the step:
    moving the at least one setting element (5) between the different setting positions, whereby the hemming die (2) is subjected to compression or tension under the effect of the setting element (5) and the hemming die contour (K) is deformed into different deformation states (D1, D2) and consequently adjusted.

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