Bending press and bending method

Abstract

A forming operation on a workpiece clamps the workpiece between a first clamping jaw with a first shaping edge, and an adjustable second clamping jaw with a second shaping edge so that a portion projects between the shaping edges and afterwards a bending edge of an adjustable bending bar is guided at a distance past the shaping edges, whereby the portion of the workpiece is angled away in relation to the part of the workpiece that is clamped between the clamping jaws. The bending edge is guided on angling along a straight path of movement of the bending edge, and after the bending edge has passed the shaping edges, the shaping edges are adjusted along an adjustment path which approaches the path of movement of the bending edge.

Claims

1. A method for forming a workpiece comprising the steps: clamping the workpiece between a first clamping jaw with a first shaping edge and a second clamping jaw with a second shaping edge so that a portion of the workpiece projects between the shaping edges; and guiding afterwards a bending edge of an adjustable bending bar at a distance past the shaping edges, whereby the portion is angled relative to the part of the workpiece clamped between the clamping jaws; wherein the bending edge of said adjustable bending bar is guided along a straight movement path and wherein after the bending edge has passed the shaping edges, said shaping edges are adjusted along an adjustment path which approaches the movement path of the bending edge.

2. The method as claimed in claim 1, wherein after the bending edge has passed the shaping edges, the movement of the bending edge is substantially or completely stopped and at the same time or immediately after the shaping edges are moved closer at a right angle perpendicular to or perpendicularly over the movement path of the bending edge.

3. The method as claimed in claim 1, wherein once the bending edge has passed the shaping edges, the shaping edges are moved closer at an inclination angle perpendicular to or perpendicularly over the movement path of the bending edge and the movement of the bending edge coupled with the adjusting movement of the shaping edges is continued until the completion of the forming process.

4. The method as claimed in claim 1, wherein the clamping jaws with their shaping edges are guided along a curved adjustment path.

5. The method as claimed in claim 4, wherein the curved adjustment path is circular.

6. The method as claimed in claim 1, wherein the bending edge of said adjustable bending bar is guided along the straight movement path in a vertical oriented direction.

7. The method as claimed in claim 1, wherein the bending edge of said adjustable bending bar is guided along the straight movement path in an orientation different from the vertical orientation.

8. The method as claimed in claim 1, wherein the shaping edges of the clamping jaws are adjusted along the adjustment path at a right angle with respect to the straight movement path of the bending edge of said adjustable bending bar.

9. The method as claimed in claim 1, wherein the shaping edges of the clamping jaws together with the clamped workpiece are adjusted along the adjustment path.

10. The method as claimed in claim 1, wherein the distance in a horizontal direction between clamping beams supporting the clamping jaws and the bending bars can be adjusted.

11. The method as claimed in claim 10, wherein the clamping beams supporting the clamping jaws are each adjusted along a straight adjustment path and the straight adjustment path of each of the clamping beams supporting the clamping jaws run parallel to one another.

12. The method as claimed in claim 11, wherein said adjustment paths of the clamping beams supporting the clamping jaws run at an inclination angle relative to the straight movement path of the bending edge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the invention the latter is explained in more detail with reference to the following Figures.

(2) In a much simplified, schematic representation:

(3) FIG. 1 shows the method for shaping a workpiece prior to beginning the shaping process;

(4) FIG. 2 shows the method for shaping a workpiece at the end of the shaping process;

(5) FIG. 3 shows a view of a possible embodiment of a bending press according to the invention;

(6) FIG. 4 shows a cross-sectional view of a possible embodiment of a bending press;

(7) FIG. 5 shows a cross-sectional view of a further possible embodiment of a bending press;

(8) FIG. 6 shows a cross-sectional view of a further possible embodiment of a bending press.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) FIGS. 1 and 2 show the method according to the invention for shaping a workpiece 1, wherein FIG. 1 shows the state prior to beginning the shaping process and FIG. 2 the state at the end of the shaping process. This is a special embodiment of the shaping method known as swivel bending.

(10) In this case the workpiece 1 is clamped between a first clamping jaw 2 and a second clamping jaw 3, so that a portion 4 can be angled in a subsequent shaping process relative to the rest of the workpiece 1. The workpiece 1 consists of an at least partly planar material, which is suitable for bending shaping. On the clamping jaw 2 a shaping edge 5 is formed which is effective when the portion 4 is angled downwards, and on the second clamping jaw 3 a second shaping edge 6 is formed which is effective if the portion 4 is angled upwards. In the shown embodiment the clamping jaws 2, 3 have a shoe-like cross-section, whereby a workpiece 1 can be bent over the shaping edges 5, 6 beyond a right angle. The angling of the portion 4 is performed by means of a bending bar 7, which has a bending edge 8. FIGS. 1 and 2 show a bending bar 7 with a bending edge 8 which is provided for angling the portion 4 downwards.

(11) The shaping edges 5, 6 are provided with a radius which also influences the smallest possible inner radius of the bent workpieces at the shaping point.

(12) During the shaping process the bending bar 7 is moved downwards approximately at a right angle to a horizontal workpiece plane 9, the bending edge 8 having a horizontal distance 10 from the shaping edges 5, 6.

(13) The distance 10 is selected to be at least as large as a workpiece thickness 11 and is preferably 1.5 times to 8 times the workpiece thickness 11. In particular with thick workpieces 1 a larger distance 10 can facilitate the introduction of the shaping process by means of a better levering effect.

(14) In the shaping method according to the invention the bending edge 8 is guided along a straight movement path 12, even after it has passed the two shaping edges 5 and 6 and thereby the portion 4 is moved into an angled position. With fixed clamping jaws 2, 3 with such a straight movement path 12 of the bending edge 8 the portion 4 can be angled by a maximum of up to 90°, if a distance 10 is selected which corresponds approximately to the workpiece thickness 11, by an unavoidable springing back after distancing the bending edge 8 in this way with the straight movement of the bending edge 8 only a shaping angle of less than 90° can be achieved. In the shaping methods known from the prior art therefore the bending bar 7 with the bending edge 8 is moved after passing the shaping edges 5, 6 differently from the straight movement path 12 with a movement component parallel to the workpiece plane 9 on the clamping jaws 2, 3, whereby the portion 4 can be shaped beyond a shaping angle of 90°. This requires that the guiding of the bending bar 7 has to allow movement in both vertical direction and horizontal direction.

(15) In contrast to this method known from the prior art with the method according to the invention the bending edge 8 stays even after passing the shaping edge 5, 6 on its straight movement path 12, and an angling of the portion 4 beyond 90° means that the shaping edges 5, 6 of both clamping jaws 2, 3 together with the clamped workpiece 1 are adjusted along an adjustment path 13 which approaches the movement path 12 of the bending edge 8 and is indicated in FIG. 2 by an arrow.

(16) Whereas in the known shaping method of the swivel bending the bending bar 7 has to perform a comparatively complicated movement, in order to achieve an angled movement of the bending edge relative to the shaping edges 5, 6, the method according to the invention is simplified in that the bending bar 7 and the clamping jaws 2, 3 only have to cover straight movement paths, whereby the guides required for this have a structurally simple design.

(17) The workpiece 1 angled downwards by the bending edge 8 prior to the transverse movement of the clamping edges 5, 6 is indicated in Fig. by dashed lines. The following reduction in the distance 10 between the clamping jaws 2, 3 and the bending bar 7 or the shaping edges 5, 6 and the bending edge 8 after passing the shaping edges 5, 6 is achieved accordingly from a relative movement running transversely to the straight movement path 12 between the clamping jaws 2, 3 and the bending bar 7. It is possible in this case that with this relative movement the bending bar 7 is in a stationary position and only the clamping jaws 2, 3 with the clamped workpiece 1 are moved, however it is also possible that the straight movement of the bending edge 8 is continued along the movement path 12 and at the same time the clamping jaws 2, 3 are adjusted along an adjustment path running transversely to the movement path 12, wherein a right-angled or oblique relative movement is performed between the bending bar 7 and clamping jaws 2, 3. The adjustment path 13 of the clamping jaws 2, 3 is thus oriented not necessarily at a right angle to the movement path 12 of the bending edge 8, but can also run obliquely to the latter along a straight line or also along a curved path running obliquely to the movement path 12, for example a circular path. FIG. 2 shows with a dashed arrow such a curved adjustment path 14, which can be produced for example by means of an eccentric bearing of the clamping jaws 2, 3 or the machine parts supporting the latter.

(18) FIGS. 1 and 2 also show with a double arrow the clamping movement 15 of the clamping jaw 3 relative to the clamping jaw 2. An alternative embodiment of the method is also indicated in FIG. 2, in which the bending bar 7 is moved along a movement path 16 different from the vertical direction but indicated straight by a dashed arrow and the clamping jaws 2, 3 together with the clamped workpiece 1 follow an oblique adjustment path 17 relative to the vertical direction. The adjusting movements of the bending bars 7 and the clamping jaws 2, 3 can thus be coupled by a control device so that a relative movement is performed which is optimal for the shaping process.

(19) FIG. 3 shows a rear view of a bending press 18 according to the invention by means of which the shaping method can be performed described with reference to FIGS. 1 and 2.

(20) The bending press 18 comprises a machine frame 19, in which the adjustable bending bar already described by FIGS. 1 and 2 and the two clamping beams supporting the clamping jaws 2, 3 can be mounted adjustably. The shown machine frame 19 comprises on its front side 20 a plate-like O-frame 21 and on its rear side 22 also a plate-like O-frame 23. The recesses in the O-frame 21 and 23 form a through opening 24, which extends through the bending press 18 and enables the feeding of a workpiece 1 to the clamping beam or the bending bar 7 and for example also enables the removal of the bent workpiece on the rear side 22.

(21) On the front side 20 of the bending press 18 in the shown embodiment a support device 25 is arranged which can support the part of a workpiece 1 located outside the bending press 18 and optionally also in addition performs the movements executed by the clamping jaws 2, 3 with the clamped workpiece 1 synchronously in order to avoid unwanted workpiece deformations. This adjustability of the support device 25 is indicted in FIG. 3 by double arrows in the main coordinate directions.

(22) The machine frame 19 also comprises side stands, which in the shown embodiment connect the two O-frames 21, 23. Intermediate spaces between supporting components of the machine frame 19 can be closed by covers, whereby a largely closed machine exterior is provided.

(23) FIG. 4 shows a cross section of a further embodiment of a bending press 18, by means of which a workpiece 1 can be angled.

(24) A workpiece 1 can be inserted through a through opening 24 in the machine frame 19 into the inside of the bending press 18, where it is held for performing the shaping process by means of a clamping device 26. The clamping device 26 comprises a first clamping beam 27 which supports the first clamping jaw 2 and a second clamping beam 28 which supports the second clamping jaw 3. The second clamping beam 28 can be adjusted by means of a clamping beam guide 29 and a clamping beam drive 30 relative to the first clamping beam 27. The first lower clamping beam 27 is widened in this embodiment to an O-frame 31 which extends into the upper half of the bending press 21 and supports the fixed part of the clamping beam guide 29. The latter comprises for example a linear guide rail, by means of which the upper second clamping beam 28 is guided in vertical direction in the machine frame 19. The clamping beam drive 30 is formed in the shown embodiment by a hydraulic cylinder 32, but can also be designed as a spindle drive with an electric motor.

(25) The adjustable bending bar 7 is mounted adjustably by means of a bending bar guide 33 in the form of a linear guide 34 on the machine frame 19 and is driven by a bending bar drive 35, here in the form of a hydraulic cylinder 36. The bending edge 8 at the lower end of the bending bar describes a straight movement path 12 (see FIG. 1, 2), which in the shown embodiment runs in vertical direction. By means of an oblique bending bar guide 33 a different movement path 12 is possible than the vertical direction. As also shown in FIG. 4, the bending edge 8 can also be formed by a bending tool 37 fixed replaceably onto the bending bar 7. Furthermore, the bending edge 8 can be adjusted in length for the required bending task by arranging such bending tools 37 in a row.

(26) In FIG. 4 it is also shown by dashed lines that underneath the first bending bar 7 an additional bending bar 38 with an additional bending edge 39 can be provided by means of which a workpiece 1 can also be angled upwards. A view of the bending bar guide and the bending bar drive is omitted for a better overview at this point.

(27) In order to perform the bending method already described with reference to FIGS. 1 and 2, the clamping beams 27 and 28 supporting the clamping jaws 2, 3 are mounted adjustably by means of a transverse guide 40 and an adjusting drive 41 relative to the machine frame 19 in horizontal direction. By means of this adjustability a portion of the workpiece 1 angled by means of the bending bar 7 or the bending edge 8 can be angled over a shaping angle of more than 90°.

(28) The adjusting drive 41 is supported on the one hand on the machine frame 19 and on the other hand on the O-frame 31 which is connected to the lower clamping beam 27 and via the clamping beam guide 29 to the upper clamping beam 28. The O-frame 31 is guided on its lower side and its upper side over the transverse guide 40 on the machine frame 19, whereby a linear guide is provided as the transverse guide 40 in the shown embodiment. An alternative to this embodiment would also be a transverse guide 40 by means of bearing eccentrically on the machine frame 19, whereby a circular arc-shaped adjustment path, already shown in FIG. 2 for moving the clamping jaws 2, 3 close to the movement path of the bending edge 8 is possible.

(29) The adjusting drive 41 is formed in the shown embodiment by two hydraulic cylinders 42, which perform synchronized movements and thereby ensure an even horizontal adjustment. In this embodiment of a bending press 18 it is an advantage that the lower clamping jaw 2 during the shaping process has no vertical movement component and thereby also a clamped workpiece 1 only has to be moved in horizontal direction. A vertical adjustment of a support device 25 is not necessary in this case.

(30) FIG. 4 also shows that the clamping jaws 2, 3 can be composed of clamping tools 43 secured onto the clamping beam 27, 28.

(31) FIG. 5 shows a further and possibly independent embodiment of a bending press 18, wherein the same reference numerals and component names have been used as in the preceding FIGS. 1 to 4.

(32) In the embodiment shown in FIG. 5 the machine frame 19 comprises two spaced apart O-frames 21 and 23, between which cooperating clamping beams 27 and 28 and the alternatively used bending bars 7 and 38 are mounted adjustably.

(33) The bending bars 7, 38 support, as already described with reference to FIG. 4, bending tools 37, with which a bending edge 8 or 39 is formed adapted to the respective bending task. The bending tools 37 can be guided adjustably, for example by means of movement spindles 44, automatically along the bending bars 7, 38.

(34) The bending bars 7 and 38 are mounted adjustably by means of linear guides 34 on the inside of the O-frame 23 and are also drive-connected by means of not-shown bending bar drives 35, for example in the form of hydraulic cylinders or spindle drives by electric motor.

(35) The clamping beams 27 and 28 supporting the clamping jaws 2, 3 are mounted on the inside of the additional O-frame 21, wherein the clamping beam guide 29 of the upper clamping beam 28 is arranged obliquely relative to the bending bar guide 33 in the form of the linear guide 34.

(36) The obliquely arranged clamping beam guide 29 is in this embodiment a component of the transverse guide 40, which also comprises a clamping beam guide 45 of the lower clamping beam 27. The latter is aligned to be parallel to the clamping beam guide 29 of the upper clamping beam 28, for which reason the clamping beams 2 and 3 clamping a workpiece 1 can be adjusted precisely synchronously with one another. For this purpose clamping beam drives are provided, not shown in FIG. 5, which comprise for example hydraulic cylinders or spindle drives with electric motors. The adjusting drive 41 for the clamping beams 27 and 28 is formed in this embodiment by the two synchronized bar frame drives. Alternatively, it is also possible to lock the two clamping beams 27 and 28 mechanically with a workpiece 1 clamped in between and to adjust both clamping beams 27, 28 by means of only one clamping beam drive, whereby also an adjusting drive 41 can be formed for the transverse movement of the clamping beam 27 and 28 relative to the bending bar movement. As also shown in FIG. 5 on the bottom clamping beam 27 a support element 46 can be provided which forms part of a support device 25 for a workpiece 1. The two O-frames 21 and 23 are connected to one another by side stands 47 or other transverse connectors, whereby the flow of force is established between the two O-frames 21 and 23.

(37) The oblique position of the clamping beam guides 29 and 45 can be produced for example by wedge-shaped spacers 48, onto which bearing rails can be secured for the linear guides of the clamping beam guides 29, 45. An inclination angle 49 between the linear guide 34 of the bending bar 7, 38 and the clamping beam guides 29, 45 is in particular between 10° and 30°.

(38) FIG. 6 shows a further and possibly independent embodiment of the bending press 18, wherein the same reference numerals and component names have been used for the same parts as in the preceding FIGS. 1 to 5. To avoid unnecessary repetition reference is made to the detailed description of the preceding FIGS. 1 to 5.

(39) The embodiment according to FIG. 6 has a similar kinematics for the bar frame movement as the embodiment according to FIG. 5, but unlike FIG. 5 a central, plate-like frame part 50 is provided on the opposite outsides 51 and 52 of which the bending bar guides 33, 34 or the clamping beam guides 29 and 45 are arranged. The flow of force from the shaping edges to the bending edge is performed in this embodiment directly via the central frame part 50 and in this embodiment the side stands 47 can be dimensioned to be weaker owing to the smaller load. In this embodiment the central frame part 50 is designed for example as an O-frame and this results in a very large bending clearance both in front of and behind the bending tools.

(40) In the described embodiments it is also possible that two spaced apart and opposite oriented bending bars 7, 38 are arranged on a common bar frame, in particular an O-frame, and the latter can be adjusted linearly by means of the bending bar guide 33 in the form of the linear guide 34.

(41) Finally, as a point of formality, it should be noted that for a better understanding of the structure of the bending press 18, the latter and its components have not been represented true to scale in part and/or have been enlarged and/or reduced in size.

(42) The exemplary embodiments show possible embodiment variants of the bending press 18, whereby it should be noted at this point that the invention is not restricted to the embodiment variants shown in particular, but rather various different combinations of the individual embodiment variants are also possible and this variability, due to the teaching on technical procedure, lies within the ability of a person skilled in the art in this technical field.

(43) Furthermore, individual features or combinations of features from the shown and described different example embodiments can in themselves represent independent solutions according to the invention.

(44) The problem addressed by the independent solutions according to the invention can be taken from the description.

(45) Lastly, it should be noted that in the variously described exemplary embodiments the same parts have been given the same reference numerals and the same component names, whereby the disclosures contained throughout the entire description can be applied to the same parts with the same reference numerals and same component names. Also details relating to position used in the description, such as e.g. top, bottom, side etc. relate to the currently described and represented figure and in case of a change in position should be adjusted to the new position.

(46) All of the details relating to value ranges in the present description are defined such that the latter include any and all part ranges, e.g. a range of 1 to 10 means that all part ranges, starting from the lower limit of 1 to the upper limit 10 are included, i.e. the whole part range beginning with a lower limit of 1 or above and ending 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.

(47) Mainly the individual embodiments shown in FIGS. 1, 2; 3; 4; 5; 6 can form the subject matter of independent solutions according to the invention. The objectives and solutions according to the invention relating thereto can be taken from the detailed descriptions of these figures.

LIST OF REFERENCE NUMERALS

(48) 1 workpiece 2 clamping jaw 3 clamping jaw 4 portion 5 shaping edge 6 shaping edge 7 bending bar 8 bending edge 9 workpiece plane 10 distance 11 workpiece thickness 12 movement path 13 adjustment path 14 adjustment path 15 clamping movement 16 movement path 17 adjustment path 18 bending press 19 machine frame 20 front side 21 O-frame 22 rear side 23 O-frame 24 through opening 25 support device 26 clamping device 27 clamping beam 28 clamping beam 29 clamping beam guide 30 clamping beam drive 31 O-frame 32 hydraulic cylinder 33 bending bar guide 34 linear guide 35 bending bar drive 36 hydraulic cylinder 37 bending tool 38 bending bar 39 bending edge 40 transverse guide 41 adjusting drive 42 hydraulic cylinder 43 clamping tool 44 spindle 45 clamping beam guide 46 support element 47 side stand 48 spacer 49 inclination angle 50 frame part 51 outside 52 outside