EP3041618B1 - Bending machine and method for bending a sheet metal workpiece - Google Patents

Description

The invention relates to a bending machine comprising at least three bending punches, each having mutually parallel working edges, as set forth in claim 1, and a method for bending a sheet metal workpiece on such a bending machine, as specified in claim 11.

From the EP 0 476 092 B1 a bending machine is known in which an upper counter-punch relative to a frame, transverse to the sheet plane, from an upper retracted position to a lower working position and back is movable. This counter-holder stamp are two arranged on the frame, lower punch opposite, the two lower bending punch are mounted pivotably about an axis extending in the region of the bend of the sheet axis in the frame and coupled together by a pivoting mechanism. The fact that the two lower bending punch are coupled in the pivot mechanism, it is achieved that in a deformation of the sheet through the upper counter-punch, the two legs of the sheet are bent symmetrically. Furthermore, the upper counter-holder punch can be pivotally mounted so that sheets with protruding tabs can be bent in a larger bending angle.

At one of the US 8,322,176 B2 known bending machine to be machined sheet metal workpiece is clamped in its edge region by means of a clamping device and then deformed by two freely movable in space bending punch, which are arranged on the two opposite surfaces of the sheet. These two bending punches are each arranged on a hexapod construction. As a result of the fact that the two bending punches in a region of the sheet metal exert a force on the respective opposite side of the sheet metal, the sheet metal can be deformed in this local zone. Disadvantageous in the in the EP 0 476 092 B1 described embodiment of a bending machine, that the two legs of the sheet to be machined can be bent only symmetrically by the coupling of the two lower punch. As in a conventional bending operation on a press brake, both legs thereby lift off from an original starting plane in which the metal sheet was inserted. This is special disadvantageous for large sheet metal workpieces, since both sides of the upper punch a danger area arises in which is at a non-automated bending machine of the operator, which is responsible for inserting the sheet metal workpiece is at risk. Even with a fully automated bending machine is a double-sided pivoting of the sheet metal workpiece disadvantageous because the manipulation device must be carried along with the pivoted sheet metal leg. Another disadvantage is that due to the common axis in which the two bending dies are pivotally mounted on the frame, an adjustment of the distance between the two punch punches and thus changing the die width is not possible.

The present invention has for its object to provide a bending machine, which ensures a variety deformability of the sheet metal workpiece to be machined Furthermore, the possibility should be opened that at least one bending leg of the sheet metal workpiece during the bending process in an initial plane which defines the initial position of the sheet metal workpiece remains. This is intended to minimize the safety risk for the machine operator, since at least on that side of the bending machine, on which the sheet metal workpiece is inserted, the bending leg should remain in a rest position during the bending process. Furthermore, in a further development of the bending machine, the force peaks of the forces acting on the bending machine should be reduced as much as possible during the bending process. Such a bending machine should also not damage the surface of the sheet metal workpiece during the bending process.

This object of the invention is achieved by a bending machine with the features according to claim 1 or by the special bending method with said bending machine according to claim 11. In particular, by the use of at least three bending dies, which each have mutually parallel working edges, a bending machine can be realized in which the sheet to be machined is touched at the three working edges of the three bending punch. Furthermore, by the expression that at least the second bending punch has three degrees of freedom in the reference plane or the third bending punch has at least one rotational and translational degree of freedom with respect to the reference plane, it can be ensured that during the bending process the bending punches are guided flexibly along an arbitrary trajectory can, that a bending leg of the sheet metal workpiece during the bending process in a in the output plane lying position remains. Furthermore, the arbitrary trajectory can be chosen so that the relative movement between the sheet metal workpiece and the bending leg are kept as low as possible during the bending process.

According to the invention, a bending machine for bending a sheet metal work piece, comprising at least three bending punches, each having mutually parallel working edges formed. With respect to an output plane in which a bending section of the sheet metal workpiece to be processed is located, the first and the second bending punch are positioned on one side, and the third bending punch is positioned on the opposite side of the output plane. The working edge of the third bending punch is adjustable between the working edges of the first and second bending punch. The third bending punch has at least one rotational and one translational degree of freedom in a reference plane oriented at right angles to a working edge. The second punch has three degrees of freedom in the reference plane.

An advantage of the design according to the invention is that due to the high number of degrees of freedom, and therefore possibilities of movement of the individual bending dies, a bending process can be realized which combines the advantages of die bending and pivoting bending. For example, the high flexibility of the bending machine, the sheet metal workpiece deforming punch can be performed along a trajectory that the smallest possible relative movement between the punch and sheet metal workpiece is formed, whereby the surface of the sheet metal workpiece is protected from damage. Surprisingly, not only the surface of the sheet metal workpiece can be protected by optimizing the trajectories of the individual bending dies, but also the necessary energy input by the bending machine during the bending process can be minimized. This can be attributed to the fact that a considerable amount of energy is converted into heat by a relative movement between the punch and the sheet metal workpiece, or that further a certain amount of energy is expended to damage the sheet metal workpiece. Thus, not only the quality of the surface of the workpiece to be machined can be positively influenced, but can be reduced during the bending process of the necessary energy input through the bending press in the sheet metal workpiece. Furthermore, can be achieved by the high flexibility of this bending machine that at least one of the two punch can dwell in any output level, whereby it can be easily absorbed and moved by a manipulation unit coupled to the bending machine. A great advantage of this is the possibility of using a simple manipulation device for transporting and removing the sheet metal workpieces, for example by a simple conveyor belt. Another advantage of the bending machine according to the above characteristics is that for very large sheet metal workpieces, the space requirement of the bending machine can be reduced by the fact that the shorter bending leg is bent, and the longer bending leg remains in its initial position. According to the invention, a support body defining the output plane is designed for a sheet metal workpiece. It is advantageous in this case that this support body can be designed either as a simple support table, or as a special construction for the feed and the positioning of sheet metal workpieces. In a manual feed of the sheet metal workpieces to be processed sheet metal workpiece is placed on the support body and positioned with the aid of a stop element. It can be provided that the stop element is integrated directly into the support body. For an automated feed of the sheet metal workpieces, it is conceivable that in the support body, for example, a conveyor is integrated, which is used for Zufördern the workpieces to be processed. Furthermore, it can be provided that the support body is movable and thus can record a workpiece to be machined from a defined transfer position and this can then perform the bending machine. For this purpose, it can also be provided that the support body is designed to pivot about a transverse axis, or about its vertical axis.

According to a development, it can be provided that the third bending punch has three degrees of freedom. The advantage here is that thereby the variety of applications of the bending machine and thus the variation of the bends of Blechwerkstückenen be further increased. Furthermore, it can be achieved by this measure that the "die width" of the bending machine can be adjusted by adjusting the distance between the first and second bending punch, and the third punch can then be positioned symmetrically between these two punch punches. According to the invention, it is provided that the first bending punch has at least one translational degree of freedom in the reference plane. The advantage here is that thereby the variety of applications of the bending machine and thus the variation of the bends of Blechwerkstückenen can be further increased. For example, in the embodiment with only one translatory degree of freedom in the horizontal direction, the "die width" can be adjusted. When executing the translational degree of freedom in the vertical direction, for example, the attack side of the punch can be moved to the opposite side of the output plane and therefore to the opposite side of the sheet metal. If the first punch has more than one degree of freedom, it can be moved according to the positioning capabilities of the third punch.

Furthermore, it can be provided that the first and the second bending punch are movable independently of each other. It is advantageous in an independent movement of the first and the second punch that during the bending process, for example, the first punch can be left in its position and only the second punch performs a kind of pivotal movement to bend the sheet metal workpiece. This ensures that one leg of the processed sheet metal workpiece can remain in a horizontal position. Furthermore, it is expedient that the three bending punches for positioning according to the number of their degrees of freedom with a drive mechanism selected from a group comprising rotary drive, rotary actuator, linear drive or combinations thereof are connected. The degree of freedom in the reference plane is a possibility of movement of the bending punch in this reference plane. The possibility of movement of the punch is implemented by one of the above drives in a movement and positioning movement of the punch. For the implementation of movement possibilities of a bending punch according to its degrees of freedom there are several different possibilities, which are mentioned here. One degree of freedom in the reference plane, for example, means that the bending punch in this plane can perform a rectilinear motion in one direction. This will be realized by a linear drive which moves the bending punch. However, a degree of freedom in the reference plane can also mean that the bending punch can perform a rotational movement, such as a rotation about its working edge. This rotational movement is implemented either by a rotary drive or by a rotary actuator. Two degrees of freedom in the reference plane mean that the punch has either two translational degrees of freedom, one translational and one rotational degree of freedom, or two rotational degrees of freedom. Two translatory degrees of freedom mean that the punch can be positioned at any point in the plane, but its orientation can not be changed. This can be realized by a combination of two linear drives, which are arranged, for example, in a main direction and in a secondary direction normal to them. Of course, it is not only possible that these linear drives are normal to each other, but it can also be implemented a kind of parallel kinematics, in which the linear drives have a common crosspoint, whereby this point of the punch is freely movable in the reference plane. A translational and a rotational degree of freedom can be implemented, for example, by a swivel arm with a linear drive connected thereto. Another possibility is a linear drive with attached rotary head. The maximum freedom of movement of a punch is achieved by three degrees of freedom and a corresponding combination of the necessary drives. This can be achieved by a bending punch any point in the range of the punch with any orientation of the punch. The possibilities of combinations of drives is very diverse and can be deduced from the above descriptions.

According to an expedient development, provision can be made for at least one of the bending punches to be connected to two drive mechanisms that are distanced in the direction of the working edge, in particular of the same type. It is advantageous here that a bending punch, if it has along its working edge a large length, is supported on both sides of this longitudinal extent by a drive mechanism, whereby the forces introduced into the punch can be optimally absorbed. As a result, the forces acting on the bending punch by the bending process forces can be intercepted symmetrically on the both sides mounted drive mechanisms, whereby no torques occur at the point of a drive mechanism. It seems to make sense if these drive mechanisms mounted on both sides of the punch are designed to be identical, since they have to carry out the same movements for a guide of the punch, in which all the working edges are constantly parallel to each other. Also in the case that it is necessary in a bending process that the working edges are not parallel to each other run, it seems to make sense, if still a same design drive pair is used.

According to a development it can be provided that at least one of the bending punches is adjustable in the direction of its working edge, or is adjustable about a pivot axis parallel to the reference plane. It is advantageous in this development that after completion of the bending process, the bending tool can be swung out, for example, so that a processed sheet metal workpiece can be easily removed from the bending machine. Instead of swinging out a bending punch can also be provided that the punch is extended linearly along its working edge from its working position. In order to keep the installation space of the machine as low as possible, a combination of swinging out and linear extension can also be provided. In this case, for example, the bending punch can be extended linearly in half, and then swung out about its center in order to minimize the space required for this procedure.

In an advantageous development, it can be provided that at least one of the bending punches has two working edges which are approximately opposite each other. Through the use of two opposing working edges, the versatility of the punch can be increased, which also bends in sections opposing orientations can be performed with this punch without the bending punch must be rotated by 180 ° with respect to its working edge. Here, the punch must be placed only on the opposite side of the sheet metal workpiece to allow an oppositely oriented bend.

Furthermore, it may be expedient that at least one of the three bending dies is assigned a further bending punch, which is arranged on the opposite side of the starting plane, wherein the working edges of these two opposing bending dies are trimmed to one another. It is advantageous in such an embodiment of the bending machine that the versatility of the bending machine can be increased by the use of two opposing bending dies. Such an arrangement is ideal, especially for bends in orientations in opposite directions, since the bending dies do not have to be pivoted or brought to the opposite side of the starting plane in order to bend in the opposite direction of a preceding bend. At a such an arrangement, only one bending punch, which was currently in operation was to be removed from the work area of the sheet metal workpiece to be bent, and the other punch can instead be brought into the labor. By this procedure, a sequence of bends, which are carried out in opposite directions, can be realized very quickly and efficiently.

Furthermore, it may be advantageous that in at least one of the bending punch and / or in the drive device, a force measuring element is integrated. By this measure it can be achieved that the required bending force can be measured, whereby conclusions can be drawn on the material properties of the workpiece to be machined, this information can be incorporated into an active bending angle control. Furthermore, by means of a force sensor in combination with the knowledge of the current position and the geometry of the punch, for example, the sheet thickness can be determined because the force sensor returns a reading of a measured force as soon as the sheet metal workpiece touches all three bending dies, and thus clamped between them , Furthermore, such a force measuring element can detect when the sheet metal workpiece is no longer clamped at the end of a bending operation, while relieving the bending punch, and thus the sheet metal workpiece is fully spring-back and has reached its bending angle, which it is maintained due to the plastic deformation. This can be recalculated on the position of the punch, which bending angle was realized on the sheet metal workpiece. These measurements and calculations can be included in a statistical evaluation in the control unit of the bending machine, whereby an adaptation of the bending parameters for future workpieces to be bent is achieved.

Furthermore, it can be provided that at least one of the bending punches has at least one stop surface. An advantage of the expression of a stop surface in one of the bending punch is that the bending punch can be used as a stop unit to correctly position a sheet metal workpiece to be bent, especially when manually inserting the workpiece. As a result, on the one hand space and on the other hand can be saved cost because no own stop unit must be performed in the bending machine. Furthermore, it is particularly expedient to provide one of the bending punch with a stop surface, since the position, or the geometry of the punch must be determined very accurately anyway for the labor of the bending machine.

In addition, a method may be provided, in which for bending a sheet metal workpiece on a bending machine which has three bending dies with mutually parallel working edges, wherein with respect to an output plane in which a bending section to be processed of the sheet metal workpiece lies on one side of the first and the second Bending punch are positioned, and on the opposite side of the output plane of the third punch is positioned. In this case, the working edge of the third bending punch is adjusted between the working edges of the first and second bending punch, and the third bending punch is moved in at least one rotational and one translational direction in a reference plane oriented at right angles to a working edge. It is further provided that during the bending process, the sheet metal workpiece between the first and third working edge is held substantially in the starting plane, whereby a first bending leg is formed and the working edge of the second punch is guided along a path around the working edge of the third bending punch, whereby at the third Working edge of the bending edge and then a second bending leg is formed on this.

It is advantageous here that a bending machine which has three bending punches can be operated by this method. By such a method, the advantages of Gesenkbiegens and the pivoting bending are combined. The advantages of the Gesenkbiegens are, for example, that by three working edges on which the sheet metal workpiece is touched, a well-defined and very beautiful bending edge can be generated. In addition, by adjusting the die width, the bending force to be applied during the bending operation can be regulated very well. The advantages of the pivoting bending, for example, that during the bending process, one of the two bending legs of a processed sheet metal workpiece remains in a horizontal output plane. Furthermore, it can be achieved by the high flexibility of the bending method described here that the smallest possible relative movement between the punch and sheet metal workpiece is created by a freely definable movement possibility of the punch. As a result, on the one hand the surface of the sheet metal workpiece is protected from damage, and on the other hand, the necessary deformation energy can be minimized during this bending process. Furthermore, by actively guiding the bending punch in the reference plane, the deformation of the sheet metal work piece can be carried out so that either one leg of the sheet metal workpiece remains in a constant position relative to the starting position, or that both legs to a certain extent Angled angles to the starting plane. Through these possibilities, the bending machine is ideal for automation tasks, since the position of the workpiece to be machined should be precisely defined here for the transfer of the sheet metal workpiece to a manipulation unit.

Furthermore, it can be provided that the path of the second working edge is set so that it contacts the sheet metal workpiece with the least possible relative movement during the bending process. A control of the punch with attention to this aspect is particularly advantageous because the sheet metal workpiece is not damaged by largely avoiding relative movement between the punch and sheet metal workpiece. Such damage can be, for example, notches or grinding grooves in the sheet metal workpiece. Furthermore, by reducing relative movements, the necessary forming energy can also be reduced, since a certain amount of energy input is necessary for the unwanted damage of the workpiece surface in the form of damage.

Furthermore, it may be expedient that before or during the bending process, the distance between the first and the second working edge is set and / or adjusted as a function of workpiece properties. It is particularly advantageous that the "Gesenkweite" can be adjusted by changing the distance between the first and second working edge. As a result, the force peaks of the bending forces acting on the bending machine forces can be adjusted because a greater distance between the first and second working edge has the consequence that the introduced by the punch in the sheet metal workpiece bending moment at the same effective force of the punch becomes larger. This allows the sheet metal workpiece to be bent more easily. Especially with different sheet thicknesses, the free adjustability of the "Gesenkweite" is very advantageous because for sheet metal workpieces, which have a higher sheet thickness, simply the "Gesenkweite" can be increased. This possibility can also be used to sheet thickness fluctuations, which occur due to the manufacturing tolerances for rolled sheets. In addition to these properties of the bending force regulation can be made flexible by changing the "Gesenkweite" and the bending radius, or the shape of the area of the sheet metal workpiece, which lies between the working edges of the punch. Of particular advantage here is that through the years of experience of the applicant in the press brake area, the calculation programs, or the knowledge in connection with the three-point bending and variable Gesenkweite is present. It can thereby be achieved that the calculation programs on which such a bending process is based can be designed with the aid of years of know-how.

Furthermore, it can be provided that the distances between the third and first working edge and the third and second working edge are kept approximately the same during the bending process. The advantage here is that act by adjusting an approximately equal distance between the working edges of the individual bending punch, the forces acting symmetrically on the two bending legs of the sheet metal workpiece. As a result, a sheet metal workpiece can be produced, in which on the one hand, the bending radius has a uniform course, and also the two bending legs of the sheet metal workpiece are formed symmetrically in the vicinity of the bending edge.

Furthermore, it may be advantageous that during the bending process, the bending punches are guided oriented substantially at right angles to the workpiece surface. That a punch is oriented perpendicular to the workpiece surface means that essentially the vertical axis of the punch, on which also the working edge of the punch and the point of force application of a drive mechanism is oriented at right angles to the workpiece surface. By this measure can be achieved that in the punch no bending moment is initiated, which could be caused by a distance between the point of application of the drive mechanism and force vector of the force exerted on the sheet metal workpiece to be bent force.

Furthermore, it can be provided that for bending the sheet metal workpiece in sections opposing orientations before the respective bending operation of the first and / or second bending punch are required, positioned on the one or on the opposite side of the output plane. The advantage here is that by the ability to position the punch on both sides of the output level to increase the variety of possible bends on the sheet metal workpiece. The positioning of the bending punch is always carried out so that the first and the second bending punch are placed on one side of the output plane, and placed on the opposite side of the output plane of the third punch with its working edge between the first and second bending die lying. Now for a bend in the opposite direction, the punch on the opposite side of the Output level are placed, so the orientation of the punch must be adjusted. This ensures that the working edge of the punch is always aligned so that it is oriented in the direction of the sheet metal workpiece to be processed.

Furthermore, it may be appropriate that for bending the sheet metal workpiece in sections opposing orientations another bending punch is used, which is arranged opposite one of the three punch, with only three bending punches are always working during the bending process. It is advantageous here that by using further bending punches, which essentially represent a reflection of one of the three bending punches about the starting plane, one of the three bending punches does not have to be brought to the other side of the starting plane for bending in the opposite direction, but rather that for a bend in the opposite orientation of the other punch is used instead of one of the three punch. As a result, the machine time can be reduced because the positioning of the punch can be shortened.

Furthermore, it is advantageous for at least one of the bending punches in the direction of its working edge, or for a pivot axis parallel to the reference plane, to be removed from the working area for feeding or removal of a sheet metal workpiece. As a result, it is also possible to produce sheet metal workpieces whose bending legs have a large length and which can only be produced with difficulty using the conventional method of swivel bending or bending. Furthermore, it can be achieved that, in connection with the sheet metal manipulation, complicated Ausfädelvorgänge sheet metal workpiece are largely avoided.

Finally, it can be provided that the sheet thickness and / or the bending angle can be calculated by determining the position of a punch and the measurement of the force exerted on the sheet metal workpiece to be bent force. It is advantageous here that the position of the punch is known anyway, or is specified by the control unit of the bending machine. The geometry of the punch is known. By measuring the force exerted on the bending workpiece force, the sheet thickness and / or the bending angle can be calculated. Furthermore, it is possible by the measurement of the bending force during the bending process already to integrate the expected springback of the sheet metal workpiece in the calculations for the intended bending angle, creating a possible Bending can be omitted. Especially by the detection of the sheet thickness and the force to be applied in the bending process, it is possible to predict the bending behavior of the sheet metal workpiece on the basis of statistical records, whereby the final bending angle can be well precalculated.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

eine Übersichtsdarstellung einer Biegemaschine mit drei Biegestempel;

Fig. 2

eine perspektivische Ansicht eines Schnittes durch einen Biegestempel mit zwei einander gegenüber liegenden Arbeitskanten;

Fig. 3

eine perspektivische Ansicht eines Biegestempels mit Antriebsmechanismus;

Fig. 4

Kombinationsmöglichkeiten zur Realisierung eines Antriebsmechanismus welcher einen Freiheitsgrad eines Biegestempels in einer Ebene gewährleistet

Fig. 5

Kombinationsmöglichkeiten zur Realisierung eines Antriebsmechanismus welcher zwei Freiheitsgrade eines Biegestempels in einer Ebene gewährleistet;

Fig. 6

Kombinationsmöglichkeiten zur Realisierung eines Antriebsmechanismus welcher einen Freiheitsgrad eines Biegestempels gewährleistet;

Fig. 7

eine Darstellung der Bewegungsabläufe der Biegestempel während eines Biegevorganges;

Fig. 8

eine Darstellung der Bewegungsabläufe der Biegestempel während eines Biegevorganges in gegensinnige Richtung;

Fig. 9

eine perspektivische Ansicht eines Schnittes einer möglichen Ausführungsvariante zur Umsetzung einer Biegemaschine mit drei Biegestempel;

Fig. 10

eine perspektivische Ansicht einer möglichen Ausführungsvariante zur Umsetzung einer Biegemaschine mit drei Biegestempel;

Fig. 11

eine schematische Darstellung der Möglichkeiten zur Blechdickenmessung, beziehungsweise zur Biegewinkelbestimmung an einem Blechwerkstück;

Fig. 12

einen Biegestempel mit einer integrierten Anschlagfläche

In each case, in a highly simplified, schematic representation:

Fig. 1

an overview of a bending machine with three bending punch;

Fig. 2

a perspective view of a section through a bending punch with two opposing working edges;

Fig. 3

a perspective view of a punch with drive mechanism;

Fig. 4

Combination possibilities for the realization of a drive mechanism which ensures a degree of freedom of a punch in a plane

Fig. 5

Combination options for the realization of a drive mechanism which ensures two degrees of freedom of a punch in a plane;

Fig. 6

Possible combinations for the realization of a drive mechanism which ensures a degree of freedom of a punch;

Fig. 7

a representation of the movements of the punch during a bending process;

Fig. 8

a representation of the movements of the punch during a bending operation in the opposite direction;

Fig. 9

a perspective view of a section of a possible embodiment for implementing a bending machine with three bending punch;

Fig. 10

a perspective view of a possible embodiment for implementing a bending machine with three bending punch;

Fig. 11

a schematic representation of the possibilities for sheet thickness measurement, or for bending angle determination on a sheet metal workpiece;

Fig. 12

a bending punch with an integrated stop surface

By way of 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 names, the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and these position information in a change in position mutatis mutandis to transfer to the new location.

Fig. 1 shows in an exemplary representation of the section through a bending machine 1 and to be processed sheet metal workpiece 2, which is oriented in an output plane 3. In this case, the sheet metal workpiece 2 is essentially located on a first bending punch 4 and on a second punch 5. A third bending punch 6 is positioned on the opposite side of the starting plane 3. The three bending punches 4, 5, 6 touch the sheet metal workpiece 2 to be bent essentially at its working edges 7, 8, 9. Between the working edges 7 and 8 of the first and second bending punch 4 and 5 is the bending section 10, in which the essential transformation of the sheet metal workpiece 2 takes place. The bending punch 4, 5 act here similar to the die of a press brake as a lower tool, and the third punch 6 acts like an upper tool of a press brake. Upon contact of all three bending punches 4, 5, 6 with the sheet metal workpiece 2 to be machined, the largest bending moment in the sheet metal workpiece 2 is introduced at the bending edge 11. This bending edge 11 is almost coherent with the third working edge 9 of the third bending punch 6. By the bending edge 11, the sheet metal workpiece 2 within the bending portion 10 in a first Bending leg 12 and a second bending leg 13 divided. These two bending legs 12, 13 are deformed during the bending process only in their lying within the bending portion 10 part. As shown in this schematic diagram, the sheet metal workpiece 2 to be machined can also rest on a support body 14 in addition to the first bending punch 4 and the second bending punch 5. The support body 14 may be formed as a simple support table, which only serves to support the sheet metal workpiece 2. This is particularly advantageous if the sheet metal workpiece is very large. It is also possible that the support body 14 comprises a conveyor 15, which is responsible for the manipulation of the sheet metal workpiece 2. Such a conveyor 15 may for example be a conveyor belt integrated in the support body 14, which is used for the transport of the sheet metal workpiece 2.

For particularly long sheet metal workpieces 2 with long bending legs 12, 13, it is also conceivable that a further support body 16 is formed, on which the sheet metal workpiece 2 can rest. Furthermore, it is possible that a stop unit 17 is formed, which serves for positioning of the sheet metal workpiece 2. This stop unit 17 can either be designed as a stand-alone element or it can also be integrated in a support body 14, 16. Of course, it is possible that the stop unit 17 not only takes over positioning tasks, but that this is also used simultaneously for the sheet metal manipulation.

By adjusting the first bending punch 4 and / or the second bending punch 5, the distance 18 between the two bending dies 4, 5, which essentially defines the bending portion 10, can be adjusted. In this case, it is advantageous if the third bending punch 6 is positioned between the first bending punch 4 and the second punch 5 in such a way that it comes to rest symmetrically between the two punching dies 4, 5.

Fig. 2 shows a perspective view of a punch 4, 5, 6, which is shown in a reference plane 19 cut. The bending punch 4, 5, 6 shown in this view has at both ends of its high expansion a working edge 7, 8, 9. Thereby, it can be used so that it lying on both sides of the output plane 3, the sheet metal workpiece 2 with its working edge 7, 8, 9 can touch, causing him to use on the opposite Side of the output level 3 does not have to be pivoted. Thus, a bending of a sheet metal workpiece 2 in the opposite direction with such a punch 4, 5, 6 realized well.

In the Fig. 2 are the possible movement possibilities, also called degrees of freedom, located in which the bending punch 4, 5, 6 can be moved in the reference plane 19. The movement possibilities consist in a transverse direction 20, which corresponds to a guide direction along the output plane 3, a vertical direction 21, which corresponds to a guide along a direction normal to the output plane 3 and a direction of rotation 22, which rotation of the bending punch 4, 5, 6 in the reference plane 19 corresponds. By combining the guiding possibility along a transverse direction 20 and a vertical direction 21, in principle any point in the reference plane 19 can be achieved with the bending punch 4, 5, 6. By a further possibility of movement of the direction of rotation 22 not only each point in the reference plane 19 can be achieved, but also the orientation of the punch 4, 5, 6 are set at this arbitrary point.

Fig. 3 shows a schematic structure of a combination of different drive mechanisms 23 in order to position a bending punch 4, 5, 6 in the reference plane 19 can arbitrarily. In order to move a bending punch 4, 5, 6, it is necessary to couple it to a drive mechanism 23. This drive mechanism is responsible for the positioning of the punch 4, 5, 6 in the reference plane 19. According to the number of degrees of freedom of a punch 4, 5, 6, there are various ways to implement the drive mechanism 23 by combining various rotary actuators 24, pivot drives 25 and linear drives 26.

Fig. 4a and 4b , such as Fig. 5a to 5e show several possible combinations of drives to a bending punch 4, 5, 6 to move in the reference plane 19.

Fig. 4a and 4b show the simplest embodiment of a drive combination in which a degree of freedom is given by a drive mechanism 23. This can either be like in Fig. 4a represented by a linear drive 26 can be accomplished or by a in Fig. 4b shown rotary drive 24 or rotary actuator 25. In this case, either the position a bending punch 4, 5, 6 are changed in one direction, or the position of the punch 4, 5, 6 are changed in the reference plane 19.

Fig. 5a to Fig. 5e shows various arrangements by the bending punch 4, 5, 6 given two degrees of freedom to move, which are realized by appropriate drives. On the one hand, as in Fig. 5a shown two degrees of freedom are made possible by a combination of two linear actuators 26, which is not required that they are necessarily at right angles to each other. In this case, the bending punch 4, 5, 6 can be brought into any position in the reference plane 19, however, its orientation is not changeable. Another possibility is a combination of rotary or rotary actuator 24, 25 and linear drive 26. Here, as in Fig. 5b represented by a machine frame from the linear drive 26 the rotary or rotary actuator 24, 25 upstream or be as in Fig. 5c illustrated the rotary or rotary actuator 24, 25 upstream of the linear drive. Another possibility is as in Fig. 5d and 5e shown to combine two rotary or rotary actuators 24, 25, which may be installed at different positions of the drive mechanism 23. Also, a combination of these drives results in either the position or the position of the punch 4, 5, 6 are not arbitrary.

According to the examples shown here, a combination of the drive mechanism can be realized in which three drives are used to arbitrarily position and orient the bending punch 4, 5, 6 in the reference plane 19. Due to the diversity of the embodiments, however, an exact description of the possibilities and / or graphic design is dispensed with here, since the individual execution options are in any case made up of a combination of the in 4 and 5 assembled embodiments shown.

Fig. 6 shows a schematic diagram of a sequence of a bending process. Here, the sheet metal workpiece 2, which was clamped between the punch punches 4, 5, 6, bent by the movement of the punch 5 along a path 27. The third bending punch 6 can be tilted during the bending process in order to achieve an optimum bending result.

The trajectory 27 of the second punch 5, in particular the working edge 7 should be chosen so that the least possible relative movement between the punch 5 and the sheet metal workpiece 2 occurs. As a result, not only is the workpiece surface 28 protected, but also the energy required for the bending process can be minimized. Also, the third punch 6 should be moved with the sheet metal workpiece 2, that no relative movement between this and the sheet metal workpiece 2 occurs. In the bending process, as in Fig. 6 is shown, the first bending leg 12 remains horizontal and the second bending leg 13 is pressed by the second bending punch 5 upwards. The transformation of the sheet metal workpiece 2 takes place mainly in the bending edge 11.

Fig. 7 shows the same schematic diagram of a bending process as in Fig. 6 is shown, but here the second bending leg 13 is not bent upwards, but the second bending leg 13 is bent in the opposite direction down. For this purpose, it is necessary that all three bending punches 4, 5, 6 are brought to the respective opposite side of the starting plane. On the second side of the starting plane, the bending dies 4, 5, 6 must then each be pivoted by 180 ° so that their working edges 7, 8, 9 again face the sheet metal workpiece 2 to be machined. To avoid this pivoting process, can also be considered that a punch as in Fig. 2 is shown, which has two opposing working edges 7, 8, 9.

Fig. 8 shows a similar schematic diagram of the arrangement of bending dies 4, 5, 6, as shown in Fig. 6 is shown, but here is for a bend to be executed in the opposite direction, not provided that, as in Fig. 7 shown, the bending punch 4, 5, 6 are moved to the other side of the output level 3, but at least one further punch 29 is provided, which is not engaged in the bending operation in one side and in a bending operation in the other side than Replacement for the respective punch 4, 5, 6 is used, so that these bending punch 4, 5, 6 need not be brought to the other side of the reference plane 19 and also their orientation does not need to be changed.

Fig. 9 shows a possible construction of such a bending machine with three bending dies. Here, the first punch 4 and the second punch 5 are each coupled to a drive mechanism 23, which two linear actuators and a rotary actuator includes. By this drive mechanism 23, the bending punch 4, 5 in a certain work area 30 of the bending machine, which is within the reference plane 19, freely positionable. The drive mechanism 23 connects the bending punches 4, 5 to the machine frame 31. Further connected to the machine frame 31 is a drive mechanism 23 for the third bending punch 6, which comprises a rotary drive and a linear drive. Thus, the third punch 6 is pivotable with respect to its working edge 9 and further zubewegbar on the sheet metal workpiece 2 or removable from this. The illustrated bending machine was cut in the reference plane 19, which is located exactly in the middle of the bending machine. The second half of the bending machine not shown here is a symmetrical illustration of the in Fig. 9 illustrated half of the bending machine. To thread out the sheet metal workpiece after a bending operation, it makes sense if the bending punch 4, 5, 6 can each be swung out of the working area 30 about a pivot axis 32, so that the sheet can be easily removed from the bending machine. This Ausschwenkvorgang the bending punch 4, 5, 6 may also be necessary if they must be positioned for a bend in the opposite bending direction on the opposite side of the output level 3.

In Fig. 10 will be in the Fig. 9 shown bending machine shown in a non-cut state. The drive mechanisms 23 of the respective punch 4, 5, 6 are shown on both sides of the punch 4, 5, 6. At these drive mechanisms 23, the bending punch 4, 5, 6 are attached.

Fig. 11 shows a schematic diagram in which a force measuring element 33 is mounted on the third bending punch 6, by which force measuring element 33 and by determining the position of the bending punch 4, 5, 6, the sheet thickness 34 and the bending angle 35 can be determined. The sheet thickness 34 can be determined by bringing all the bending punch 4, 5, 6 in an upright position. Thereafter, the sheet metal workpiece 2 is placed on the first punch 4 and the second punch 5. Subsequently, the third punch 6 is moved so far down until the force measuring element 33 returns a value to the machine control, thus it is registered when the third punch 6 touches the sheet metal workpiece 2. The fact that the position of the individual punch 4, 5, 6 is specified by the machine control highly accurate, and is retrievable at any time, can now be recalculated to the plate thickness 34.

The procedure for determining the bending angle is as follows. Here, the sheet metal workpiece 2 is bent, wherein a plastic, as well as an elastic deformation occurs during the bending process. If the sheet metal workpiece 2 is now bent over by its elastic component, that is to say it is bent too much, then the sheet metal workpiece 2 will spring back by its elastic component when the bending punch 4,5,6 retracts. Now, if the force on the force measuring element 33 is zero, the bending angle 35 is reached, which is maintained by plastic deformation resistant. Due to the geometry and the position of the individual bending punch 4, 5, 6 can now be calculated back to the reached bending angle.

The force measuring element 33 may be, for example, a piezo element which is integrated in the bending punch 4, 5, 6. However, it can also be switched between bending punch 4,5,6 and drive mechanism 23 so as to detect the force acting on the punch 4,5,6 forces.

Fig. 12 shows a further embodiment of a bending punch 4, 5, 6 in the bending punch 4, 5, 6, a stop surface 36 is formed, on which the sheet metal workpiece 2 can be posted.

In the Fig. 1-12 are independent and possibly independent embodiments of the bending machine 1 shown, again with the same parts the same reference numerals or component names are used. The representation and the description of the embodiments are limited to the exemplary embodiments and arrangement examples of the bending punch 4, 5, 6. As a basis for the description of the individual arrangements existing press brakes, or folding machines were used. It is therefore to be understood that certain components of a bending machine, such as press beams, in which the bending punches 4, 5, 6 are integrated, or a control device have not been explicitly described, since these are well-known components, which of course in the present bending machine for Use can come.

The embodiments show possible embodiments of the bending machine 1 wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather also various combinations of individual variants are mutually possible and this variation possibility due to the doctrine of technical action by objective invention in the skill of those working in this technical field is the expert.

Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

The task underlying the independent inventive solutions can be taken from the description.

All statements of value ranges in the present description should be understood to include any and all sub-ranges thereof, e.g. is the statement 1 to 10 to be understood that all sub-areas, starting from the lower limit 1 and the upper limit 10 are included, ie. all sub-areas begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the bending machine 1, these or their components have been shown partially unevenly and / or enlarged and / or reduced in size. <B> Reference Numbers </ b> 1 bending machine 31 machine frame 2 Sheet metal work 32 swivel axis 3 output level 33 Force measuring element 4 first bending punch 34 sheet thickness 5 second bending punch 35 bending angle 6 third bending punch 36 stop surface 7 first working edge 8th second working edge 9 third working edge 10 bending section 11 bending edge 12 first bending leg 13 second bending leg 14 support body 15 Conveyor 16 additional support body 17 stop unit 18 distance 19 reference plane 20 transversely 21 vertical direction 22 direction of rotation 23 drive mechanism 24 rotary drive 25 Rotary actuator 26 linear actuator 27 train 28 Workpiece surface 29 another bending punch 30 Workspace

Claims (19)

1. A bending machine (1) for bending a sheet metal workpiece (2), comprising at least three bending punches (4,5,6), which respectively have working edges (7,8,9) which are aligned parallel to one another, wherein relative to an initial plane (3) in which a bend section (10) to be made in the sheet metal workpiece (2) lies, the first and the second bending punch (4,5) are positioned on one side and the third bending punch (6) is positioned on the opposite side of the initial plane (3) and the working edge (9) of the third bending punch (6) is displaceable between the working edges (7,8) of the first and second bending punches (4,5), wherein the third bending punch (6) has at least one rotary and one translatory degree of freedom in a reference plane (19) oriented at a right angle to a working edge (7,8,9), wherein the second bending punch (5) has three degrees of freedom in the reference plane (19), characterized in that a supporting body (14) defining the initial plane (3) and structurally separate from the first bending punch (4) is provided for a sheet metal workpiece (2) and that the first bending punch (4) has at least one translatory degree of freedom in the reference plane (19).
2. The bending machine according to claim 1 or 2, characterized in that the third bending punch (6) has three degrees of freedom.
3. The bending machine according to one of the preceding claims, characterized in that the first and the second bending punch (4,5) can be moved independently of one another.
4. The bending machine according to one of the preceding claims, characterized in that to enable positioning and depending on the number of their degrees of freedom, the three bending punches (4,5,6) are connected to a driving mechanism (23) selected from a group comprising rotary drives (24), swivel drives (25), linear actuators (26) or combinations thereof.
5. The bending machine according to claim 4, characterized in that at least one of the bending punches (4,5,6,29) is connected to two driving mechanisms (23), in particular of identical construction, spaced apart from one another in the direction of the working edge (7,8,9).
6. The bending machine according to claim 4 or 5, characterized in that at least one of the bending punches (4,5,6) is displaceable in the direction of its working edge (7,8,9) or is displaceable about a pivot axis (32) parallel to the reference plane (19).
7. The bending machine according to one of the preceding claims, characterized in that at least one of the bending punches (4,5,6) has two working edges (7,8,9) lying approximately opposite one another.
8. The bending machine according to one of the preceding claims, characterized in that at least one of the three bending punches (4,5,6) co-operates with an additional bending punch (29) which is disposed on the opposite side of the initial plane (3), wherein the working edges (7,8,9) of these two oppositely lying bending punches (4,5,6;29) are directed towards one another.
9. The bending machine according to one of the preceding claims, characterized in that a force-measuring element (33) is integrated in at least one of the bending punches (4,5,6,29) and/or in the driving mechanism (23) thereof.
10. The bending machine according to one of the preceding claims, characterized in that at least one of the bending punches (4,5,6,29) has at least one stop face (36).
11. A method of bending a sheet metal workpiece (2) on a bending machine having three bending punches (4,5,6) which respectively have working edges (7,8,9) which are aligned parallel to one another, wherein relative to an initial plane (3) in which a bend section (10) to be made in a sheet metal workpiece (2) lies, the first and second bending punch (4,5) are positioned on one side and the third bending punch (6) is positioned on the opposite side of the initial plane (3), wherein the working edge (9) of the third bending punch (6) is displaced between the working edges (7,8) of the first and second bending punch (4,5) and the third bending punch (6) is moved in at least one rotary and one translatory direction in a reference plane (19) oriented at a right angle to a working edge (7,8,9), characterized in that during the bending operation, the sheet metal workpiece (2) is retained between the first and third working edges (7,9) essentially in the initial plane (3) so that a first bend leg (12) is formed, and the working edge (8) of the second bending punch (5) is directed along a path (27) about the working edge (9) of the third bending punch (6), so that the bend edge (11) and a second bend leg (13) adjoining it is formed at the third working edge (6).
12. The method according to claim 11, characterized in that the path (27) of the second working edge (8) is set so that it makes contact with the sheet metal workpiece (2) with as little relative movement as possible during the bending operation.
13. The method according to one of claims 11 or 12, characterized in that before or during the bending operation, the distance (18) between the first and the second working edge (7,8) is set and/or adjusted depending on workpiece properties.
14. The method according to one of claims 11 to 13, characterized in that during the bending operation, the distances (18) between the third and first working edge (7,9) and the third and second working edge (8,9) may be kept more or less the same size.
15. The method according to one of claims 11 to 14, characterized in that the bending punches (4,5,6,29) are directed onto the workpiece surface (28) oriented essentially at a right angle during the bending operation.
16. The method according to one of claims 11 to 15, characterized in that in order to bend the sheet metal workpiece (2) in partially opposite directions, the first and/or second bending punches (4,5) is or are positioned on one side or on the opposite side of the initial plane (3), if necessary, before the respective bending operation.
17. The method according to one of claims 11 to 16, characterized in that in order to bend the sheet metal workpiece (2) in partially opposite directions, an additional bending punch (29) is used which is disposed lying opposite one of the three bending punches (4,5,6), wherein only three bending punches (4,5,6;29) are ever active use during the bending operation.
18. The method according to one of claims 11 to 17, characterized in that in order to introduce or remove a sheet metal workpiece (2), at least one of the bending punches (4,5,6,29) is removed from the working area (30) in the direction of its working edge (7,8,9) or about a pivot axis (32) parallel to the reference plane (19).
19. The method according to one of claims 11 to 18, characterized in that the sheet thickness (34) and/or the bend angle (35) can be calculated by determining the position of a bending punch (4,5,6,29) and measuring the force applied to the sheet metal workpiece to be bent (2).

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