EP1584385B1 - Bending tool for bending workpieces, in particular metal sheets, as well as bending machine with such a bending tool - Google Patents

Abstract

A guide roller (47) and a guide pin (50) are linked with a workpiece support included in a retaining device and positioned on the same side of a workpiece as the guide roller and guide pin. The retaining device, guide roller and guide pin can be moved relative to a swivel lever (23) and a corresponding cam gate (46) in the direction (8) of a bending stroke. An independent claim is also included for a bending machine.

Description

The invention relates to a bending tool for bending workpieces, in particular sheets, along a bending line, with at least one arranged on one side of a workpiece bending member and at least one holding device which has on opposite sides of the workpiece in the workpiece transverse direction holding members, by means of which under relative movement the mutual holding members in the workpiece transverse direction, the workpiece is fixed to the holding device, wherein the holding device with the workpiece fixed thereto and a bending member on the other hand under bending the workpiece with a working movement relative to each other are movable and the working movement of a component in a workpiece transverse direction extending stroke direction and a Component has in a transversely to the plane defined by the direction of the bending line and the stroke direction plane extending transverse stroke direction and wherein for directional control of Arbeitsbewegun g a motion control is provided with at least a motion associated with a bending member control in the form of a backdrop and with at least one provided on the bending member associated workpiece side control in the form of a slotted guide, which is arranged to move with a arranged on the same side of the workpiece, the same holding member of the holding device. The invention further relates to a bending machine with at least one such bending tool.

Generic prior art is known from WO 96/24445 A1 , This document discloses a bending tool, which is provided for generating the workpiece movement to be executed during the working movement of a workpiece on the one hand and a bending member on the other hand with a complex designed deflection gear. Provided are in particular a two-armed lever for implementing the executed in the stroke direction workpiece movement in a counter-movement of the bending member and springs, by means of which a link connected to the bending member and a slide guide are held in contact with each other. The installation space required for the previously known arrangement is correspondingly large.

A bending tool and a bending machine are also known from JP 59 033032 A , The bending tool disclosed in this publication comprises a tool top arranged above a workpiece to be machined, and a tool bottom arranged below the workpiece to be machined. The tool upper part comprises a spring-mounted in the workpiece transverse direction in the initial state holding plate and laterally next to this a punch. The bending punch is mounted pivotably about a pivot axis running parallel to the bending line of the workpiece bend to be created and provided with a control surface inclined towards the workpiece transverse direction. The lower tool part consists essentially of one of the retaining plate of the Tool upper part opposite support block and a laterally spaced from this control block. The control block also has an inclined control surface on its side facing the bending punch of the tool upper part. A sheet to be processed is placed on the support block of the lower tool part. Subsequently, the tool upper part is lowered in the workpiece transverse direction to the lower tool part. In this case, the holding plate of the upper tool part runs on the sheet metal surface facing it. The sheet is now clamped between the holding plate of the upper tool part and the support block of the lower tool part. With continued lowering movement of the upper tool part whose retaining plate remains stationary. The bending punch of the upper tool part, however, is moved further in the direction of the lower tool part. In this case, the bending punch acts with a forming edge on the laterally opposite the holding plate of the upper die and the support block of the lower die part projecting sheet edge. At the same time, the control surface of the punch comes to rest against the control surface on the control block of the lower die part. In interaction, the mutual control surfaces effect a pivoting movement of the lowering punch around its pivot axis. Overall, there is a working movement of the punch with a component in the workpiece transverse direction and with a workpiece-parallel component

EP 0 610 706 A1 discloses a bending machine with a bending tool, which comprises an anvil-shaped tool lower part and a tool upper part with a bending member. The bending member forms a leg of an angle lever which is pivotally mounted on the upper tool part. The pivot axis of the angle lever and thus also of the bending element runs parallel to the bending line of a sheet to be created on a bend. If the tool upper part carries out a working stroke in the direction of the workpiece to be reshaped, the angle lever with its second leg runs against a stop on the workpiece side. As a result of support of the respective angle lever leg on the workpiece-side stop performs the bending member with continued working stroke of the upper tool part a pivoting movement about its pivot axis. In this case, the bending member bends the acted upon by him edge of the sheet to be formed around a bending edge of the anvil-like tool lower part.

Starting from the prior art according to WO 96/24445 A1 The object of the invention is to provide a structurally simplified and compact bending tool and a bending machine provided with such a bending tool.

This object is achieved according to the invention by the bending tool according to claim 1 and by the bending machine according to claim 10.

The controls for directional control of the working movement between the workpiece to be machined on the one hand and a bending member provided for workpiece machining on the other hand are arranged on one and the same side of the workpiece. The overall arrangement has a compact design. In this sense, the feature also has an effect, according to which the holding device with the workpiece and a control device assigned to the holding device is moved in the lifting direction relative to a bending member and a control connected thereto in the said working movement. To generate the working movement is resorted to a movement axis of the holding device, which is also used to set the workpiece to be machined on the holding device. Accordingly, there is no provision for constructive measures for generating a movement of a bending member relative to the workpiece to be machined.

Particular embodiments of the bending tool according to claim 1 and the bending machine according to claim 10 will become apparent from the dependent claims 2 to 9 and 11th

As shown in claim 2, the bending tool according to the invention has a tool base, on which at least one bending member and a motion-connected linkage are supported in the stroke direction and against the side of a similar holding member and a movement associated link guide are movable in the stroke direction.

The provided in accordance with claim 3 leadership of the holding member and the movement associated link guide on the tool base ensures defined conditions in the movement of said tool components relative to the tool base.

In the case of Erfindungsbauart according to claim 4, an automatic and collective provision of retaining member and associated slotted guide is provided in the starting position following the working movement.

According to claim 5 serves for the provision of retainer and associated control in development of the invention, a gas spring. With a gas spring according to the invention, a machine element is provided, regardless of a relatively Small construction volume is able to act on the workpiece with great force in the direction of or arranged on the opposite side of the workpiece holding members and thereby exert a very high clamping force on the workpiece.

As shown in claim 6, a side-equal holding member and a movement associated therewith link guide are provided as parts of a unit. Due to the structural design of said holding member and the associated slotted guide, the bending tool according to the invention can be assembled and disassembled in a simple manner. For example, with appropriate structural design, the retaining member and the associated slotted guide in case of need can be removed jointly from the tool base. The bending member and its control are therefore accessible with little effort.

In the case of the embodiment of the bending tool according to the invention described in claim 7, the support of at least one bending member and a motion-connected linkage on the tool base in position is adjustable. By this setting, for example, assembly and / or manufacturing tolerances on the bending tool can be compensated. Of particular importance is the adjustability of the bending member in cases where a plurality of bending tools according to the invention are arranged side by side and operated jointly. By appropriate adjustment, the bending elements of the individual bending tools can be positioned as needed to each other.

Claim 8 describes a preferred measure according to the invention for the realization of an adjustable support of bending member and thus motion-connected link to the tool base.

In a further preferred embodiment of the invention, a bending member is designed as a pivot lever which is supported on the tool base in the stroke direction and movable by means of a pivot bearing in Hubquerrichtung (claim 9).

Claim 11 relates to a preferred bending machine design according to the invention. At least one inventive bending tool is arranged in the tool holders of the machine base unit of a conventional press brake. One of the tool holders is provided with at least one bending member, at least one side-holding member and at least one of the bending member associated link and at least one side-equal holding member associated link guide. The tool holder on the opposite side of the workpiece supports at least one holding member of the holding device. The required relative to the workpiece machining relative movement of the workpiece fixed on the holding device on the one hand and at least one bending member on the other hand is generated by the usual relative movement of the tool holders on the press brake. As an alternative to bending tools according to the invention, conventional bending tools can be loaded into the tool holders of the machine base unit become. Multiple use of the machine base unit is therefore possible.

Fig. 1

eine stark schematisierte Darstellung einer Biegemaschine mit einer Bearbeitungseinheit aus mehreren Biegewerkzeugen,

Fign. 2 und 3

aufgebrochene Seitenansichten eines Biegewerkzeuges nach Fig. 1 in unterschiedlichen Phasen einer Werkstückbearbeitung,

Fign. 4 bis 6

Seitenansichten eines Biegewerkzeuges nach den Fign. 1 bis 3 in unterschiedlichen Phasen einer Werkstückbearbeitung,

Fig. 7

eine perspektivische Gesamtansicht des Biegewerkzeuges nach den Fign. 2 und 4,

Fig. 8

das als Schwenkhebel ausgebildete Biegeorgan eines Biegewerkzeuges nach den Fign. 1 bis 7.

The invention will be explained in more detail with reference to schematic representations of an embodiment. Show it:

Fig. 1

a highly schematic representation of a bending machine with a processing unit of a plurality of bending tools,

FIGS. 2 and 3

broken side views of a bending tool according to FIG. 1 in different phases of a workpiece machining,

FIGS. 4 to 6

Side views of a bending tool according to FIGS. 1 to 3 in different phases of a workpiece machining,

Fig. 7

an overall perspective view of the bending tool according to FIGS. 2 and 4,

Fig. 8

trained as a pivot lever bending member of a bending tool according to FIGS. 1 to 7.

As shown in FIG. 1, a bending machine 1 as machine base unit 2 has the machine base unit of a conventional press brake and also a processing unit 3. As usual, the machine base unit 2 comprises a machine frame 4 and a press beam 5. The machine frame 4 forms a support table 6 with a lower tool holder 7. The press beam 5 is movably guided on the machine frame 4 in a stroke direction 8 and in a return stroke direction 9. Hydraulic piston-cylinder arrangements 10 serve to drive the press beam 5. The press beam 5 is provided with an upper tool receptacle 11 on its side facing the support table 6.

In the lower tool holder 7 and the upper tool holder 11 conventional lower and upper tools of press brakes can be installed. In the example shown, the tool holders 7, 11 of the bending machine 1 but store the processing unit 3, which is shown in Fig. 1 of a total of four bending tools 12 assembled. The bending tools 12 are strung together along a dash-dotted lines in Fig. 1 indicated bending line 13 without gaps. By adding or removing one or more bending tools 12, the total width of the processing unit 3 and thus the maximum Abkantlänge be varied.

Each of the bending tools 12 comprises an upper tool in the form of a hold-down 14 and a lower tool 15, which in turn has a tool base 16 and an upper part 17. The hold-downs 14 of the bending tools 12 are mounted in the upper tool holder 11 of the press bar 5, the lower tools 15 in the lower tool holder 7 of the support table 6. Alternatively, with appropriate design of the tool holders 7, 11, the hold-down 14 of the bending tools 12 in the lower tool holder 7 and the lower tools 15, then be mounted as upper tools in the upper tool holder 11.

In detail, the structural design of the bending tools 12 results in particular from FIGS. 2 and 3.

Accordingly, the hold-down 14 of a bending tool 12 extends with an overhang relative to the vertical. At its end remote from the lower tool 15, the hold-down 14 has a fastening lug 18 with which it is held in the upper tool holder 11 on the pressing bar 5 of the bending machine 1. At its lower tool-side end of the hold-down 14 is provided with a contact surface 19. At a forming edge 20, the contact surface 19 merges into a side surface of the hold-down 14.

The lower tool 15 of each bending tool 12 rests with the tool base 16 on the support table 6 on the machine frame 4 of the bending machine 1. In this case, a projection 21 projecting on the tool base 16 engages in the lower tool holder 7 of the support table 6. At the same time the tool base 16 engages behind the support table 6 laterally with a holding projection 22. By means of the nose 21, the tool base 16 is clamped in the lower tool holder 7.

In the stroke direction 8 and in the return stroke direction 9, a bending member in the form of a pivoting lever 23 is supported on the tool base 16. As a support of the pivot lever 23 is a bearing block 24, on which the pivot lever 23 is pivotally mounted about a pivot pin 26 formed by a pivot pin 26. The bearing block 24 is in turn pivotally supported on the tool base 16 about a pivot axis 27. For performing pivotal movements of the bearing block 24 about the pivot axis 27 is an adjusting screw 28 for adjusting the position of the bearing block 24. In the respectively set position of the bearing block 24 is fixed by means of a locking screw 29.

In addition to a receptacle 30 for the bearing block 24 which is open toward the upper part 17, the tool base 16 has receptacles 31, 32 for guide columns 33, 34 and a receptacle 35 for a gas pressure spring 36.

With their arranged outside the receptacles 31, 32 longitudinal sections, the guide columns 33, 34 engage in receptacles 37, 38 on the upper part 17 of the lower tool 15 a. For the gas spring 36, a receptacle 39 is provided on the upper part 17 of the lower tool 15.

The receptacle 39 for the gas spring 36 is located on the upper part 17 of the lower tool 15 below a groove 40. The groove 40 receives a support body 41 of a workpiece support 42 of the upper part 17. Manually operable fasteners 43 hold the support body 41 in the groove 40th

The pivot lever 23 passes through the upper part 17 of the lower tool 15 at a penetration 44. Within the penetration 44, the pivoting lever 23 is pivotable about the pivot axis 26 over a limited pivoting angle and thereby movable in the lifting transverse direction, ie perpendicular to the plane, from the direction of the bending line 13 and the stroke direction 8 and the return stroke 9 is clamped. Formed on the pivot lever 23 is designed as a gate 46 control. The gate 46 on the pivoting lever 23 is assigned to the upper part 17 of the lower tool 15 also serving as a control link guide, which in turn is formed by a control roller 47 and a control pin 50.

The control roller 47 is rotatably mounted about a rotation axis 48 on a base body 49 of the upper part 17. On the main body 49 of the upper part 17 and the control pin 50 is mounted, which engages in a guide slot 51 on the pivot lever 23. In an enlarged view, the structural details of the pivot lever 23 Fig. 8 can be seen.

The sequence of processing a strip-shaped metal sheet 52 by means of a bending tool 12 results from FIGS. 2 to 7.

Before the workpiece machining, the pressing beam 5 is raised so far relative to the support table 6 of the bending machine 1 that results in a gap between the free end of the mounted on the press bar 5 blank holder 14 and the upper part 17 of the lower tool 15, in detail the workpiece support 42 , In this space, the flat plate 52 is to be inserted. The insertion depth determines the later position of the bend. The flat plate 52 is mounted on the workpiece support 42.

Now, if the press bar 5 of the bending machine 1 is lowered by means of the hydraulic piston-cylinder assemblies 10, the hold-down 14 of the bending tool 12 runs on the top side of the sheet 52 facing it and the results in the Fign. 2, 4 and 7 shown ratios. In this operating state the upper part 17 of the lower tool 15 is in the stroke direction 8 and in the return stroke 9 in its starting position relative to the tool base 16. The upper part 17 is spaced from the tool base 16 in the mentioned direction. The support of the upper part 17 on the tool base 16 via the gas pressure spring 36. The pivot lever 23 is aligned approximately vertically. The plate 52 is clamped between the blank holder 14 and the workpiece support 42 on the upper part 17 of the lower tool 15 with little force.

If now the holding-down device 14 is lowered further in the stroke direction 8 by corresponding movement of the pressing bar 5 of the bending machine 1, then the gas-pressure spring 36 exerts a comparatively large counterforce. As a result of this counterforce, the clamping of the plate 52 between the hold-down 14 and the workpiece support 42 of the lower part 14 lowering upper part 17 of the lower tool 15 is reinforced. The hold-down 14 and the workpiece support 42 accordingly assume the function of holding members for fixing the plate 52nd Increases the force exerted on the plate 52 holding force even by a friction-increasing coating of the sheet 52 overlapping surface of the support body 41 of the workpiece support 42nd

In assembly with the workpiece support 42, the control roller 47 and the control pin 50 lower on the upper part 17 of the lower tool 15 in the lifting direction 8 from. As a result of the stroke direction 8 effective support of the pivot lever 23 on the tool base 16, this results in a relative movement between the control roller 47 and the control pin 50 on the one hand and attached to the pivot lever 23 link 46 on the other. Due to the selected in the example, the shape of the gate 46 while the pivot lever 23 does not change its approximately upright starting position initially. Rather, between the pivot lever 23 and the plate 52 initially results in an approximately rectilinear vertical movement. Upon being subjected to the underside of the plate 52 with the pivot lever tip, the edge of the plate 52 projecting laterally on the hold-down 14 and the workpiece support 42 is bent upward (FIG. 5).

In the course of the further lowering movement of hold-down 14 and upper part 17 of the lower tool 15 in the stroke direction 8 causes the link 46 on the pivot lever 23 in conjunction with the control roller 47 and the control pin 50 on the upper part 17 pivotal movement of the pivot lever 23 in the figures in the counterclockwise direction. The pivot lever tip shifts accordingly with the acted upon by her edge of the plate 52 in Hubquerrichtung to the hold 14 down. In this case, the pivot lever 23 passes through a pivotal position, in which the bent edge of the sheet 52 vertically upward (Fig. 6). At the end of the lowering movement of hold-down 14 and upper part 17 of the lower tool 15, the edge of the sheet 52 by means of the pivot lever tip on the vertical position beyond the Downholder 14 bent out (Fig. 3). The upper part 17 of the lower tool 15 is now located with its underside on top of the tool base 16. The working stroke and the associated bending processing of the plate 52 are completed.

Now, if the press bar 5 moves with the hold-down 14 in the return direction 9, the upper part 17 of the lower tool 15 follows this movement initially due to its application by the prestressed gas spring 36. Also in this return stroke, the upper part 17 by means of the guide columns 33, 34 on the Tool base 16 of the lower tool 15 out.

If the gas spring 36 has reached its maximum extension length, a continued movement of the press beam 5 and hold-down 14 in the return direction 9 causes the hold-down 14 to lift off the bent plate 52. The bent plate 52 can now be removed from the bending tool 12.

Accompanied by the return stroke of the hold-down 14 is a raising of the control roller 47 and the control pin 50 on the upper part 17 relative to the pivot lever 23 and provided on this backdrop 46. Thus, the pivot lever 23, starting from the proportions of FIG. 3 in a clockwise direction in his Starting position according to FIGS. 2, 4 and 7 swung back.

To compensate for assembly and / or manufacturing tolerances, for varying the path of movement of the pivot lever tip and also for mutual adjustment of the pivot lever 23 juxtaposed bending tools 12, the position of the support of the pivot lever 23 to the tool base 16 can change. For this purpose, first the locking screw 29 is to be solved on the bearing block 24. Subsequently, by turning the adjusting screw 28, the pivotal position of the bearing block 24 with respect to the pivot axis 27 and thus the position of the pivot axis 26 of the pivot lever 23 can be changed. In the changed position, the bearing block 24 is then to be fixed again by means of the locking screw 29. As in particular the Fign. 4 to 7 can be seen, the adjusting mechanism of the bearing block 24 on the bending tool 12 in befindlicher in installation upper part 17 of the lower tool 15 is accessible.

But even for disassembly of the upper part 17 only a few handles are required.

First, the fastening elements 43 are to be solved, by means of which the support body 41 of the workpiece support 42 is fixed in the groove 40. If subsequently the support body 41 is removed from the groove 40, the attachment of the gas pressure spring 36 to the upper part 17 is accessible. After loosening this attachment, the upper part 17 can be removed as a unit from the tool base 16. The control pin 50 on the upper part 17 can thereby exit from the guide slot 51 of the pivot lever 23 through the mouth lying in the direction of withdrawal. Accordingly, the assembly of the upper part 17 on the tool base 16 of the lower tool 15 is simple.

With the upper part 17 removed, for example, the existing pivoting lever 23 can be exchanged with link 46 against another pivot lever link unit. A changed link geometry requires a change of the maximum bend angle that can be realized with the respective pivot lever. In addition, an adjustment of the bending tool 12 can be made to changed thicknesses and workpiece materials by using a backdrop with modified backdrop geometry.

It is also conceivable replacement of the pivot lever 23 shown in the figures against a pivot lever with a 13 wider in the direction of the bending line pivot lever tip. In particular, it may be advisable, instead of the illustrated pivot lever 23 to use a pivoting lever whose pivot lever tip is aligned at its side walls with the side walls of the lower tool 15. If a plurality of bending tools 12 provided with such a pivoting lever are lined up without gaps in the direction of the bending line 13, then a forming edge, which is continuous in the direction of the bending line 13, results at the lower tools 15 of the bending tools 12.

Claims (11)

1. Bending tool for bending workpieces, especially metal sheets (52), along a bending line (13), having at least one bending element (23) disposed on one side of a workpiece and having at least one locating device which has locating elements (14, 42) on mutually opposite sides of the workpiece in the transverse direction of the workpiece, by means of which, with relative movement of the locating elements (14, 42) on both sides in the transverse direction of the workpiece, the workpiece can be immobilised on the locating device, wherein the locating device with the workpiece immobilised thereon, on the one hand, and a bending element (23), on the other hand, are movable relative to each other with a working movement, with the workpiece being bent, and the working movement has a component in a stroke direction (8) extending in the transverse direction of the workpiece and a component in a cross-stroke direction extending transversely to the plane bounded by the direction of the bending line (13) and the stroke direction (8), and wherein, for directional control of the working movement, a movement control is provided, having at least one control element in the form of a motion link (46) which is coupled in motion with a bending element (23) and having at least one control element in the form of a motion link guide (47, 50) which is provided on the workpiece side associated with the bending element (23) and which is coupled in motion with a laterally identical locating element (42), disposed on the same side of the workpiece, of the locating device, characterised in that the motion link guide (47, 50) which is coupled in motion with the laterally identical locating element (42) of the locating device is formed by a control roller (47) on the one side and by a control pin (50) on the other side of the motion link (46) coupled in motion with the bending element (23), and in the working movement the laterally identical locating element (42) of the locating device is movable relative to the bending element (23), which is supported to be stationary in the stroke direction (8), and at the same time the control roller (47) and the control pin (50) are movable relative to the motion link (46) in the stroke direction (8).
2. Bending tool according to claim 1, characterised in that a bending element (23) and a motion link (46) which is coupled in motion therewith are supported in the stroke direction (8) on a tool base (16), and the locating device is movable, by a laterally identical locating element (42) and a motion link guide (47, 50) which is coupled in motion therewith, in the stroke direction (8) relative to the bending element (23) supported on the tool base (16) and to the motion link (46) which is coupled in motion with the bending element (23).
3. Bending tool according to either of the preceding claims, characterised in that a laterally identical locating element (42) and a motion link guide (47, 50) which is coupled in motion therewith are guided on the tool base (16) in the stroke direction (8).
4. Bending tool according to any one of the preceding claims, characterised in that a laterally identical locating element (42) supports the workpiece in the stroke direction (8) and is movably supported on the tool base (16) in the stroke direction (8), jointly with a motion-coupled motion link guide (47, 50), via a device for producing a restoring force, and the workpiece is acted upon in the stroke direction (8) on the opposite side by means of at least one locating element (14) of the locating device.
5. Bending tool according to any one of the preceding claims, characterised in that a gas spring (36) is provided as the device for producing a restoring force.
6. Bending tool according to any one of the preceding claims, characterised in that a laterally identical locating element (42) and a motion link guide (47, 50) which is connected in motion therewith are provided as an assembly unit.
7. Bending tool according to any one of the preceding claims, characterised in that the support on the tool base (16) of a bending element (23) and of a motion link (46) coupled in motion therewith is adjustable in its position.
8. Bending tool according to any one of the preceding claims, characterised in that the support on the tool base (16) of a bending element (23) and of a motion link (46) coupled in motion therewith includes a bearing block (24) which supports the bending element (23) and the motion link (46) coupled in motion therewith and which is provided in a positionally adjustable manner on a base body of the tool base (16).
9. Bending tool according to any one of the preceding claims, characterised in that a bending element (23) is in the form of a pivoted lever which, combined as an assembly unit with a motion link (46) coupled in motion therewith, is supported on the tool base (16) in the stroke direction (8) and is movably supported in the cross-stroke direction by means of a pivot bearing having a pivot axis (27) extending in the direction of the bending line (13).
10. Bending machine having at least one bending tool (12) according to any one of the preceding claims.
11. Bending machine according to claim 10, having a machine base unit (2) and tool holders (7, 11) provided thereon on both sides of a workpiece to be processed, characterised in that the machine base unit (2) of a bending press is provided as the machine base unit (2), having tool holders (7, 11) which are movable in a controlled manner relative to each other in the transverse direction of the workpiece to be processed, and at least one bending element (23) with at least one motion link (46) coupled in motion therewith and also at least one laterally identical locating element (42) with at least one motion link guide (47, 50) coupled in motion therewith are arranged in the tool holder (7) on the one side of the workpiece, and at least one locating element (14) is arranged in the workpiece holder (11) on the other side of the workpiece.

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