folding machine

Abstract

Method for bending a workpiece (W), in particular a sheet, a profile or a tube, about a bending axis by means of a swivel bending machine (1) comprising - a machine frame (2), - a slide device (8) guided in the machine frame (2) and movable linearly along a slide axis (7) with two support slides (6) and - two bending cheeks (10o, 10u) arranged between the support slides (6), which are parallel to each other and in their longitudinal extent perpendicular to the slide axis (7), wherein - the two bending cheeks (10o, 10u) are each pivotably mounted about a rotation axis (12o, 12u) on the carrier slide (6) and are movable together with the slide device (8) along the slide axis (7), - one of the two bending jaws (10o) is designed to bend a workpiece (W) around a first bending axis in the direction of one of the two bending jaws (10u) when rotated about its axis of rotation (12o), - the lower bending jaw (10u) is designed to bend a workpiece (W) around a second bending axis in the direction of the upper bending jaw (10o) when rotated about its axis of rotation (12u), and - the bending cheeks (10o, 10u) are each displaceable relative to their axis of rotation (12o, 12u), in particular translationally, by the following steps: A) Providing a workpiece (W) fixed relative to the machine frame (2), , B) Moving the slide device (8) into a first slide position, wherein in the first slide position the upper bending cheek (10o) touches the workpiece (W), C) Displacement of the lower bending cheek (10u) relative to its axis of rotation (12u, 12o), D) Pivoting the upper bending jaw (10o) about its axis of rotation (12u, 12o) to bend the workpiece (W) about a first bending axis in the direction of the lower bending jaw (10u).

Description

[0001] The present invention relates to a swivel bending machine for bending a workpiece, in particular a sheet metal part, about a bending axis.

[0002] Swivel bending machines typically feature a machine frame that encloses a rotatably mounted, horizontally arranged bending beam. The workpiece to be bent can often be clamped between an upper and a lower beam, thus fixing it relative to the machine frame. The lower beam typically defines a portion of the worktable on which the workpiece can be placed and positioned for processing. By pivoting the bending beam around its axis of rotation, the workpiece is bent along a bending axis (bend line). The bending axis divides the workpiece into a section clamped between the upper and lower beams and a bent (or to-bent) section. The bent section of the workpiece (i.e., the section of the workpiece extending beyond the bending axis) is also referred to as the bending leg of the workpiece.The bending angle refers to the angle by which the bending leg is bent along the bending axis relative to the clamped section of the workpiece.

[0003] Simple swing bending machines can only bend the workpiece in one direction, typically upwards. To enable bending the workpiece in the opposite direction without turning it (counter-rotation bending), swing bending machines with two counter-rotating bending jaws have been proposed in recent years and decades.

[0004] For example, DE 36 05 815 C2 describes such a swivel bending machine. The two counter-rotating bending jaws are mounted together on a support beam, which in turn can be swivelled about a horizontal axis together with the bending jaws. The workpiece to be bent projects with its bending leg between the two bending jaws and is held in position by means of a clamping device. If the bending leg of the workpiece is to be bent upwards, the lower of the two bending jaws is moved towards the workpiece by swiveling the support beam upwards, and then the lower bending jaw is swivelled upwards. If, on the other hand, the bending leg is to be bent downwards, the upper of the two bending jaws is moved towards the workpiece by swiveling the support beam downwards, and then the upper bending jaw is swivelled downwards.The workpiece therefore does not need to be turned to be bent in opposite directions. CH 696 158 A5 also shows a swivel bending machine with two bending jaws that can swivel in opposite directions. The two bending jaws are each mounted on a cam that can be moved at an angle to the horizontal.

[0005] The distance between the two bending jaws determines the so-called bending clearance and limits the maximum possible bending leg length in such swing bending machines. If the maximum bending leg length is exceeded, the workpiece will collide with the bending jaw not currently in use for bending at sufficiently large bending angles.

[0006] To increase the bending clearance, the distance between the pivot axes of the bending dies is increased. This typically involves raising the lower die to provide sufficient space for the lower die to swing out of the way when the upper die is used for bending. Therefore, increasing the bending clearance (by increasing the distance between the pivot axes of the bending dies) is limited, as raising the lower die is equivalent to raising the worktable, which, for ergonomic reasons and accessibility, must not be positioned too high.

[0007] Against this background, the present invention is based on the objective of providing a swivel bending machine for (counter-rotating) bending of a workpiece, which is characterized by improved practicality, in particular with regard to enabling a more compact machine design overall and a larger maximum bending leg length with minimal impact on working ergonomics.

[0008] The problem is solved by a swivel bending machine according to claim 1 and the corresponding method for bending a workpiece according to claim 9.

[0009] The swivel bending machine for (counter-rotating) bending of a workpiece, in particular a sheet metal, a profile or a tube, about a bending axis comprises - a machine frame (machine rack), - a slide device guided in the machine frame, movable linearly (especially vertically) along a slide axis, with two support slides and - two bending cheeks arranged between the support slides, which are parallel to each other and aligned perpendicular to the slide axis (in particular horizontally) in their longitudinal extent, wherein - the two bending jaws are each pivotably (rotatably) mounted on the carrier slide about an axis of rotation and can be moved along the slide axis together with the slide device, - one of the two bending jaws is designed to bend a workpiece around a first bending axis in the direction of one of the two bending jaws when rotated about its axis of rotation, - the lower bending jaw is designed to bend a workpiece around a second bending axis in the direction of the upper bending jaw when rotated about its axis of rotation, and - the bending jaws are each displaceable relative to their axis of rotation, in particular translationally, in order to change the position of the respective bending jaw relative to its axis of rotation, thereby enabling an increase or decrease in the distance between the two bending jaws.

[0010] The invention is based primarily on the realization that a unique combination of advantages can be achieved through the synergistic interaction of the features according to the invention: Firstly, the linear (especially vertical) movement of the slide device along the slide axis enables an exceptionally compact machine design, in which both the guide section of the machine frame and the associated slide drives can be arranged in a column-like configuration on both sides of the bending jaws. This advantageously minimizes the machine's footprint and facilitates access from both sides.

[0011] Furthermore, this compact machine design also improves lateral accessibility to the machine's worktable. Typically, the worktable is rectangular with a front and rear edge, each parallel to the bending axis and connected by two side edges. Machine components typically enclose the worktable at these side edges, restricting lateral access. The compact machine design minimizes these restrictions, thus improving operator ergonomics.

[0012] On the other hand, the movableness of the bending jaws relative to their respective axis of rotation allows for an increase in the bending clearance with only minimal or even no need to raise the worktable.

[0013] For this purpose, if, for example, a workpiece is to be bent around the second bending axis towards the upper bending beam using the lower bending die, the upper bending die, which is not currently being used for bending, is pivoted upwards and moved linearly upwards relative to its axis of rotation from a bending position to an offset position (translationally) in order to increase the distance between the two bending dies. The bending dies can therefore each be moved relative to their axis of rotation and thus moved towards or away from it. This movement of the bending die from the bending position to the offset position is also referred to as (bench die) offset.

[0014] This allows the distance between the two bending dies, and thus the bending clearance, to be increased without having to increase the distance between the axes of rotation of the two bending dies. This enables the processing of workpieces with longer bending legs and large bending angles without the bending leg colliding with the bending die not currently in use. Therefore, greater maximum bending leg lengths can be achieved.

[0015] According to the invention, the maximum possible distance between the two bending jaws (i.e., the bending clearance) is determined on the one hand by the distance between the axes of rotation and on the other hand by the maximum possible offset of the bending jaw when moved (from the bending position to the escape position).

[0016] By reducing the distance between the axes of rotation (while simultaneously increasing the maximum possible offset of the bending dies), a particularly energy-efficient swing bending machine can be realized while maintaining the same bending clearance. This is because reducing the distance between the axes of rotation means the carriage assembly needs to travel a shorter distance when changing the bending direction. Given the considerable weight of the carriage assembly, which is equipped with the bending dies, this approach reduces energy consumption and setup time.

[0017] According to a first preferred embodiment of the swivel bending machine, it comprises four bending cheek guides, wherein - the bending cheek guides are assigned in pairs to a bending cheek and are each arranged between the bending cheek assigned to them and one of the beam slides, - the bending cheek guides are each mounted on the beam slide together with the associated bending cheek so as to be pivotable about its axis of rotation, and - the bending jaws are each translationally displaceable relative to their associated bending jaw guides.

[0018] In this way, the distance of each bending beam to its axis of rotation – and thus the bending clearance – can be changed by moving the respective bending beam translationally relative to its associated bending beam guides. The mobility of the bending beams relative to their associated bending beam guides can therefore be achieved using a small number of components.

[0019] Particularly preferred are the bending cheeks guided linearly in the associated bending cheek guides by means of tongue and groove connections.

[0020] The tongue and groove connections enable robust, simple and precise linear guidance of the bending jaws in the associated bending jaw guides.

[0021] In a particularly advantageous way, the bending jaws are transversely displaceable relative to their associated bending jaw guides by means of at least one (in particular hydraulic or electrical) bending jaw linear actuator.

[0022] A linear actuator is a drive system capable of moving a machine element along a straight line. A linear actuator that incorporates a hydraulic cylinder is called a hydraulic linear actuator. In contrast, an electric linear actuator converts the rotational motion of an electric motor into linear motion using a gearbox.

[0023] According to a further advantageous embodiment of the invention, the slide device can be moved along the slide axis by means of a slide linear actuator, in particular a hydraulic or electric one.

[0024] Particularly preferably, the at least one slide linear actuator is designed as an electric slide linear actuator and comprises a threaded spindle and a locking device, wherein - the threaded spindle is guided in the slide device in such a way that the slide device can be moved along the slide axis by rotating the threaded spindle, and - rotation of the threaded spindle can be prevented by activating the blocking device.

[0025] If the locking device is not activated, the slide can be moved to the desired position by rotating the threaded spindle using the electric motor of the linear drive. Once in position, the locking device can be activated, preventing further rotation of the threaded spindle. When bending a workpiece, if large forces are introduced into the linear drive via the slide and generate a torque acting on the threaded rod around the slide axis, this torque can be (at least largely) absorbed or counteracted by the activated locking device. In this way, the electric motor of the linear drive, as well as any gearbox located between the electric motor and the threaded spindle, can be isolated from this torque. This advantageously increases the service life of these components and allows for a more compact design.

[0026] Particularly preferred is the locking device designed as a disc brake device and comprising a brake disc connected to the threaded spindle and a brake caliper connected to the machine frame.

[0027] Furthermore, it can be advantageously provided that the bending cheeks can each be pivoted about their axis of rotation relative to the slide device by means of at least one, in particular electric, rotary actuator.

[0028] A rotary actuator is a drive system capable of rotating one machine element relative to another. An electric rotary actuator comprises an electric motor and a gearbox, which is typically a worm gear, spur gear, planetary gear, or bevel gear.

[0029] Particularly advantageous is the provision that - the swivel bending machine has an upper jaw and a lower jaw and a workpiece to be bent, in particular a sheet, a profile or a tube, can be fixed between the upper jaw and the lower jaw, and optionally - the lower jaw forms part of a worktable on which the workpiece to be bent can be positioned.

[0030] Furthermore, the invention manifests itself in the inventive method for bending a workpiece, in particular a sheet, a profile or a tube, about a bending axis by means of a swivel bending machine according to the invention, comprising the following steps: A) Providing a workpiece fixed relative to the machine frame, wherein the workpiece is fixed in particular between the upper jaw and the lower jaw, B) Method of moving the slide device into a first slide position, wherein, in particular, in the first slide position the upper bending beam (or alternatively the lower bending beam) touches the workpiece, C) Moving the lower bending beam (or alternatively the upper bending beam) relative to its axis of rotation (to increase the distance to its axis of rotation), D) Pivoting the upper bending jaw (or alternatively the lower bending jaw) about its axis of rotation to bend the workpiece about a first bending axis in the direction of the lower bending jaw (or alternatively about a second bending axis in the direction of the upper bending jaw).

[0031] An embodiment of the invention will now be explained in more detail with reference to the drawing. The drawing shows Fig. 1 a swivel bending machine according to the invention in an oblique view, Fig. 2 the swivel bending machine according to the invention Fig. 1 in a front view, Fig. 3 the swivel bending machine according to the invention Fig. 1 in a side view, Fig. 4A - 4C schematic diagrams to illustrate the translational displacement of the bending cheeks relative to the respective axis of rotation, Fig. Figures 5A - 5C show a swivel bending machine according to the invention, each in a side sectional view, wherein the upper bending jaw and the lower bending jaw are in different positions. Fig. Figures 6A - 6C show a swivel bending machine according to the invention, each in a lateral sectional view at different times during a bending process.

[0032] First, in connection with the Fig. 1 to 3 on the basic structure of the illustrated embodiment of the swivel bending machine according to the invention, then with reference to the Fig. 4A to 6C will discuss their functionality.

[0033] The Fig. Figures 1 to 3 show a swivel bending machine 1 according to the invention in an oblique, front and side view respectively. The swivel bending machine 1 has a machine frame 2 which comprises two vertically extending guide columns 3 and two horizontally extending cross braces 4 connecting the two guide columns 3 to each other.

[0034] The guide columns 3 each have a guide groove 5 within which a support carriage 6 is guided linearly and vertically along a carriage axis 7. The two support carriages 6 are part of a carriage device 8 and are each movable by means of a carriage linear actuator 9.

[0035] Between the two support carriages 6, two horizontally extending bending beams 10o, 10u are arranged parallel to each other: an upper bending beam 10o and a lower bending beam 10u. A bending beam guide 11 is arranged between each of the bending beams 10o, 10u and the support carriages 6 that enclose them on both sides. Two bending beam guides 11 are thus assigned to the upper bending beam 10o, and two bending beam guides 11 to the lower bending beam 10u.

[0036] The bending die guides 11 are each pivotably mounted on the beam slide together with the associated bending die 10o, 10u about a rotation axis 12o, 12u. Each beam slide 6 is provided with an upper rotary actuator 13o and a lower rotary actuator 13u. The two upper rotary actuators 13o are configured to pivot the upper bending die 10o together with the associated bending die guides 11 about the rotation axis 12o of the upper bending die 10o (upper rotation axis 12o). The two lower rotary actuators 13u are configured to pivot the lower bending die 10u together with the associated bending die guides 11 about the rotation axis 12u of the lower bending die 10u (lower rotation axis 12u).

[0037] The bending cheeks 10o, 10u are guided linearly displaceable in the associated bending cheek guides 11 by means of tongue and groove connections 14 (see figure). Fig. 4C). The bending jaw guides 11 each have an electric bending jaw linear actuator 15 for this purpose. The bending jaws 10o, 10u can be translationally displaced relative to their axis of rotation 12o, 12u by means of this linear displacement. In this way, the position of the bending jaws 10o, 10u relative to their axis of rotation 12o, 12u can be changed and thus the distance between the two bending jaws 10o, 10u (bending clearance) can be increased or decreased.

[0038] The swivel bending machine 1 further comprises an upper beam 16 and a lower beam 17, which extend horizontally parallel to each other and between which a workpiece W to be bent (in particular a sheet, a profile or a tube) can be fixed. The lower beam 17 is rigidly connected to the lower of the two cross braces 4. The upper beam 16 is guided linearly and vertically within the machine frame 2 and can be moved by means of an upper beam linear actuator. The upper beam 16 includes a plurality of punch-like tools 18.

[0039] The Fig. 4A and Fig. Figures 4B show a schematic representation of the slide device 8 together with the bending jaws 10o, 10u of a swivel bending machine 1 according to the invention in a front view and a side view. Fig. 4A and Fig. The 4B differ only in that the upper bending cheek 100 is in a bending position ( Fig. 4A) and once in an evasive position ( Fig. 4B) (while the lower bending jaw 10u is always in its bending position). The upper bending jaw 10o was linearly displaced from its bending position relative to its associated bending jaw guides 11 and thus moved upwards away from the axis of rotation 12o of the upper bending jaw 10o. The distance between the two bending jaws 10o, 10u is referred to as the bending clearance. According to Fig. 4A With both bending jaws in the bending position, the bending clearance is B_4A. If, however, the upper bending jaw is bent according to Fig. When 4A is moved into its escape position, the bending clearance is increased by the offset V. The bending clearance B_4B is therefore larger than the bending clearance B_4A.

[0040] The Fig. Figures 5A to 5C illustrate the mobility of the bending jaws 10o and 10u again in lateral sectional views. The upper bending jaw 10o is in each case fully pivoted upwards, and the lower bending jaw 10u is in each case fully pivoted downwards. According to Fig. At 5A, both bending jaws 10o, 10u are in their bending positions. Fig. 5B the upper bending cheek 10° is shifted by the offset V into its escape position, in Fig. 5C the lower bending cheek 10u.

[0041] The Fig. Figures 6A to 6C illustrate the inventive method for bending a workpiece W made of sheet metal using the swivel bending machine 1 described above according to the invention.

[0042] First, as in Fig. Figure 6A shows the workpiece W fixed relative to the machine frame 2 between the upper jaw 16 and the lower jaw 17. The upper bending jaw 10o is fully pivoted upwards, and the lower bending jaw 10u is fully pivoted downwards. Both bending jaws 10o and 10u are in their bending position.

[0043] The slide device 8 is then moved into a first slide position in which the lower bending cheek 10u just touches the workpiece W.

[0044] Furthermore, the upper bending cheek 10o is moved from its bending position relative to its axis of rotation 12o into its escape position in order to increase the bending clearance.

[0045] The lower bending jaw 10u is then pivoted upwards around its axis of rotation in order to bend the workpiece W around the second bending axis in the direction of the upper bending jaw 10o.

[0046] The Fig. 6B and Fig. Figure 6C shows this pivoting of the lower bending cheek 10u at two successive times with different bending angles BW. In particular, from Fig. 6C shows that the bending leg Wb of the workpiece W would have collided with the upper bending cheek 10o if the latter had not been moved from its bending position to the avoidance position beforehand in order to increase the bending clearance. Reference symbol list 1 swivel bending machine 2 machine frames 3 guiding pillars 4 cross braces 5 guide channel 6 carrier sleds 7 Slide axis 8 Sled device 9 Sled Linear Actuators 10o upper bending cheek 10u lower bending cheek 11 Bending cheek guide 12° upper axis of rotation 12u lower axis of rotation 130 upper rotary actuator 13u lower rotary actuator 14 tongue and groove joints 15 Bending cheek linear actuator 16 Upper cheek 17 Lower cheek 18 tools B_4A, B4_B Bending clearance V offset W workpiece BW bending angle

Claims

[1] Method for bending a workpiece (W), in particular a sheet, a profile or a tube, about a bending axis by means of a swivel bending machine (1) comprising - a machine frame (2), - a slide device (8) guided in the machine frame (2) and movable linearly along a slide axis (7) with two support slides (6) and - two bending cheeks (10o, 10u) arranged between the support slides (6), which are parallel to each other and in their longitudinal extent perpendicular to the slide axis (7), wherein - the two bending cheeks (10o, 10u) are each pivotably mounted about a rotation axis (12o, 12u) on the carrier slide (6) and are movable together with the slide device (8) along the slide axis (7), - one of the two bending jaws (10o) is designed to bend a workpiece (W) around a first bending axis in the direction of one of the two bending jaws (10u) when rotated about its axis of rotation (12o), - the lower bending jaw (10u) is designed to bend a workpiece (W) around a second bending axis in the direction of the upper bending jaw (10o) when rotated about its axis of rotation (12u), and - the bending cheeks (10o, 10u) are each displaceable relative to their axis of rotation (12o, 12u), in particular translationally, by the following steps: A) Providing a workpiece (W) fixed relative to the machine frame (2), , B) Moving the slide device (8) into a first slide position, wherein in the first slide position the upper bending cheek (10o) touches the workpiece (W), C) Displacement of the lower bending cheek (10u) relative to its axis of rotation (12u, 12o), D) Pivoting the upper bending jaw (10o) about its axis of rotation (12u, 12o) to bend the workpiece (W) about a first bending axis in the direction of the lower bending jaw (10u). [2] Method according to claim 1, wherein - the swivel bending machine (1) comprises four bending jaw guides (11), - the bending cheek guides (11) are assigned in pairs to a bending cheek (10o, 10u) and are each arranged between the bending cheek (10o, 10u) assigned to them and one of the beam slides (6), - the bending cheek guides (11) are each mounted together with the associated bending cheek (10o, 10u) pivotably about its axis of rotation (12o, 12u) on the beam slide (6), and - the bending cheeks (10o, 10u) are each translationally displaceable relative to their associated bending cheek guides (11). [3] Method according to claim 2, wherein the bending cheeks (10o, 10u) are guided linearly displaceably in the associated bending cheek guides (11) by means of tongue and groove connections (14). [4] Method according to one of claims 2 or 3, wherein the bending cheeks (10o, 10u) are translationally displaceable relative to the bending cheek guides (11) associated with them by means of at least one, in particular hydraulic or electrical, bending cheek linear actuator (15). [5] Method according to one of the preceding claims, wherein the slide device (8) is movable along the slide axis (7) by means of a slide linear actuator (9), in particular a hydraulic or electric one. [6] Method according to claim 5, wherein the at least one slide linear actuator (9) is designed as an electric slide linear actuator and comprises a threaded spindle and a locking device, wherein - the threaded spindle is guided in the slide device in such a way that the slide device can be moved along the slide axis by rotating the threaded spindle, and - rotation of the threaded spindle can be prevented by activating the blocking device. [7] Method according to one of the preceding claims, wherein the bending cheeks (10o, 10u) can each be pivoted about their axis of rotation (12o, 12u) relative to the slide device (8) by means of at least one, in particular electric, rotary actuator (13o, 13u). [8] Method according to any one of the preceding claims, wherein - the swivel bending machine (1) has an upper jaw (16) and a lower jaw (17) and a workpiece (W) to be bent, in particular a sheet, a profile or a tube, can be fixed between the upper jaw (16) and the lower jaw (17), and optionally - the lower cheek (17) forms part of a worktable on which the workpiece (W) to be bent can be positioned.

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