EP2086699B1 - Method for obtaining workpiece cutouts from a plate-like workpiece - Google Patents

Abstract

Method for recovering workpiece cut-outs (2) from a plate-like workpiece (1) comprises shortening the connection between the cut-outs and the rest of the workpiece in the direction of the cutting lines (7) by cutting. The remaining residual connection (4) of the workpiece cut-outs lie with the rest of the workpiece in a processing region (5) of a cutting device used for carrying out the cutting step.

Description

The invention relates to a method for obtaining at least two workpiece cutouts from a plate-like workpiece, in particular at least two sheet metal cutouts from a sheet, wherein by preparative cutting with moving workpiece, the connection between the workpiece cutouts and the remainder workpiece by means of a cutting device partially, ie, leaving a residual connection , is cut free, wherein after the preliminary cutting by final cutting on the stationary workpiece, the remaining connection of the workpiece cutouts with the remaining workpiece by means of a cutting device along at least one cut line is cut and the workpiece cutouts are removed after the final cutting of the remaining workpiece.

Such a method for obtaining sheet metal cutouts from a sheet is in DE-C-38 32 215 described. In the context of the previously known method, a plurality of separating cuts are made on a metal sheet by means of a punching or nibbling device. For this purpose, the sheet in question is moved by means of a sheet metal handling device relative to the punching or Nibbelvorrichtung. Due to the separating cuts the connection between several sheet metal cutouts and a remaining workpiece is partially severed. Each of the partially cut-sheet metal cutouts is connected to the remainder of the work piece via a separate remainder connection that exclusively exists for this sheet metal cutout. To finally cut the sheet metal cutouts, the sheet is fed to a sheet metal shears. The maximum cutting length of the sheet metal shears corresponds at least to the length or the width of the sheet to be processed.

The sheet metal scissors created on the stationary sheet a final separation cut, which extends over the entire width or length of the sheet. As a result, several sheet metal cutouts connected along the cutting line of the final separating cut to the remainder of the work piece are completely separated from the remainder of the work piece. Subsequently, the cut-out metal cutouts slide onto a conveyor belt for removal.

A generic procedure is out EP 1 166 915 A2 known. As part of this process, the cutting processing of sheets always takes place with the workpiece stationary. Sealing sheets are produced which are to be cut out of a coil unwound from a coil. For this purpose, the sheet is successively subjected to a free cutting process (preliminary cutting) and a cutting process (final cutting) in a progressive die.

Several gaskets at the same time are only obtained in the case of a special process variant ( EP 1 166 915 A2 , Figure 8). In this case, a sheet metal section from which ultimately two sealing sheets are produced, first provided at a free cutting station with opposite lateral cutouts. Between the side cutouts remains a residual connection of the sheet metal sections with the remaining workpiece. The two to be obtained from the sheet metal section gasket sheets are not yet separated from each other at this time. The separation of the sealing plates from each other and also their separation from the remainder workpiece takes place in the final separation process, which follows the lateral free cutting of the sheet metal section.

Based on the state of the art DE-C-38 32 215 It is an object of the invention to provide a method which is extended in its use compared to the previously known method.

According to the invention, this object is achieved by the method according to claim 1. Accordingly, the connection between the workpiece cutouts and the remaining workpiece in the direction of the cutting line (s) of the final cutting cutting is already shortened by the preliminary cutting. This shortening is dimensioned such that the remaining remnant connection between the workpiece cutouts and the remainder workpiece lies in the processing area of the cutter for the final cutting cut. In this way it is according to the invention It is also possible to machine workpieces which are larger than the working area of the cutting device for the final cutting. As a result, the method according to the invention can be carried out in particular with conventional machine tools whose cutting devices used for the final separating sheath have a machining area which is smaller than the workpiece to be machined.

Particular embodiments of the method according to claim 1 emerge from the dependent claims 2 to 10.

According to claim 2, the residual joint between the workpiece cut-outs and the remainder workpiece is simultaneously cut by the final cut-cutting along the entire cut line (s). For example, a simultaneous free cutting takes place in the case of a punching free cutting by means of a single punching stroke of a punch. In this way it is avoided that an already cut workpiece cut-out slips during the free cutting of a further workpiece cutout in the stationary remainder workpiece. For a process-safe removal of the cut-cut workpiece cutouts is ensured.

In the context of the method according to claim 3, the completely cut workpiece cutouts are removed by gravity from the remainder of the workpiece. Accordingly, the workpiece cutouts fall or slip in the discharge direction. The need for handling the workpiece cutouts by means of complex handling devices is eliminated.

In the case of the method according to claim 4, the cutting according to the invention by the flexibly applicable and process-safe separation process of punching and / or laser cutting takes place.

According to claim 5, the preliminary separation cutting and the final separation cutting are performed by means of one and the same cutter. In particular, therefore, eliminates an additional transfer of the workpiece between the preparatory and the final cutting. The device for carrying out the method can u. U. get along with a single cutter.

According to the invention, the remaining connection between the workpiece cutouts and the remaining workpiece is cut free by the final cutting along cutting lines according to claim 6, which are not arranged in mutual rectilinear extension to each other. Since cuts running in different directions can be made, the workpiece cut-outs to be cut together can be flexibly arranged with respect to each other.

According to claim 7, the workpiece cutouts are arranged at the final cutting across an opening of a workpiece table supporting the workpiece. A fast and reliable removal of the workpiece cutouts is made possible.

A further measure for ensuring a high process reliability of the method according to the invention results from claim 8. Accordingly, the connection between the workpiece cutouts and the remaining workpiece is cut free by the preparatory cutting such that the workpiece cutouts remain surrounded by the remainder of the workpiece. The remaining workpiece thus encloses the workpiece cutouts like a frame. Frame-like remnant workpieces have an increased Stability against unwanted deformations. Such deformations can lead to collisions between the remaining workpiece and machine parts. Due to the increased stability of the residual workpiece such collisions are avoided and process-reliable workpiece machining is ensured.

The claims 9 and 10 relate to measures by which the time required for the final cutting and the removal of the cut-cut workpiece cutouts is reduced. According to claim 9, the residual compound according to the invention between the workpiece cutouts and the remainder of the workpiece is formed by a common connecting web. By free cutting of the common connecting web, the workpiece cutouts are simultaneously completely cut free from the remainder of the workpiece. The thus cut workpiece cutouts are simultaneously removed from the remainder of the workpiece according to claim 10.

Figuren 1a bis 1d:

ein erstes Blech zu unterschiedlichen Zeitpunkten im Laufe eines Verfahrens zur Gewinnung von zwei Blechausschnitten,

Figur 2:

ein zweites Blech mit teilweise freigeschnittenen Blechausschnitten,

Figur 3:

eine perspektivische Darstellung einer Laser- Stanzpresse zur Gewinnung von Blechausschnitten aus einem Blech.

The invention will be explained in more detail below with reference to exemplary schematic illustrations. Show it

FIGS. 1a to 1d:

a first sheet at different times in the course of a process for obtaining two sheet metal cutouts,

FIG. 2:

a second sheet with partly cut-out sheet metal cutouts,

FIG. 3:

a perspective view of a laser stamping press for obtaining sheet metal cutouts from a sheet.

In the FIGS. 1a to 1d is a plate-like workpiece in the form of a sheet 1 in the extraction of two workpiece cutouts, in particular of two sheet metal cutouts 2 shown. To carry out the method is a machine tool, as in FIG. 3 shown and as described in detail below.

FIG. 1a shows the sheet 1 during the preparatory cutting. The preparatory cutting takes place with moving sheet metal.

The two sheet metal cutouts 2, which in each case have three smaller punched holes, are still connected to the remaining workpiece 3 by a residual connection 4 at the time shown. A cutting device of the used machine tool has a processing area 5.

Except in the area of the residual compound 4, the sheet metal cutouts 2 have been separated from the sheet 1 by separating cuts 6 made by the cutting device. The remaining compound 4 between the two sheet metal sections 2 and the remaining workpiece 3 in the direction of aligned, ie rectilinearly extending cutting lines 7 is according to FIG. 1a larger than the processing area 5 of the cutting device. Consequently, the residual compound 4 can not be completely separated from the remainder of the workpiece 3 when the metal sheet 1 is stationary.

To separating cuts 6 in a at the position of the sheet 1 according to FIG. 1a To create sheet metal area lying outside of the processing area 5, the sheet metal 1 is moved or repositioned relative to the cutting device such that the sheet metal area to be processed enters the processing area 5 of the cutting device.

Based on the conditions according to FIG. 1a the residual compound 4 is shortened between the sheet metal cutouts 2 and the remaining workpiece 3 in the direction of the cutting lines 7. For this purpose, the sheet metal areas to be processed are brought into the processing area 5 of the cutting device while moving the sheet 1 relative to the cutting device. By means of the cutting device, the separating cuts 6 are lengthened in the direction of the cutting lines 7. Upon completion of the preparatory separation, the conditions are in accordance FIG. 1b one.

In FIG. 1b the sheet 1 is shown after the preliminary cutting and immediately before the final cutting. The sheet metal cutouts 2 are still connected to the surrounding frame-like remaining workpiece 3. The remaining compound 4 is now in the processing area 5 of the cutting device. The following final cutting of the sheet metal cutouts 2 is carried out along the cutting lines 7 with resting sheet 1.

Figure 1c shows the sheet 1 with completely of the frame-like remnant workpiece 3 cut-sheet metal sections 2. Based on the situation according to Figure 1c the cut-sheet metal cutouts 2 are simultaneously removed from the frame-like residual workpiece 3. In Figure 1d the remainder of the workpiece 3 is shown after removal of the sheet metal cutouts 2.

The sheet metal cutouts 2 are cut free by the final cutting without intermediate movement of the sheet 1 of the remainder of the workpiece 3 and at the same time with unchanged position of the sheet 1 or remainder workpiece 3 discharged. Due to the joint production of two sheet metal sections 2, the production time per sheet metal section 2 is shortened compared to a single part production. The final free cutting and removal of the sheet metal cutouts 2 takes place at rest Sheet 1, in order to avoid undesired slipping of the completely cut-sheet metal cutouts 2 relative to the residual workpiece 3.

Other ways to cut sheet metal cutouts from a sheet 10 shows FIG. 2 , All illustrated cut-outs are in the condition immediately before the final cut-off. They are therefore still partially connected to the remainder of work 11. In the case of the sheet 10, the remaining work piece 11 of sheet metal cutouts assigned to each other not only includes unprocessed sheet metal areas, but also each other, partially cut sheet metal cutouts.

Sheet metal cutouts 12 have been cut free during preparatory cutting in such a way from the remainder of the work piece 11 that they remain connected to the remainder of the work piece 11 via a common connecting web 13. By final cutting, the joint connecting web 13 of the sheet metal cutouts 12 is cut free with the remaining workpiece 11 by means of the cutting device along the cutting lines 14. The cutting lines 14 are arranged in this case parallel to each other.

In addition to rectangular sheet metal cutouts, sheet metal cutouts with other contours can also be cut free. This is exemplified by circular sheet metal cutouts 15. Cut lines 16, along which the circular sheet metal cutouts 15 are cut free by the final cutting cut, have a curved course and consequently run in different directions. The same applies to cutting lines 17 of sheet metal cutouts 18th

With the help of sheet metal cutouts 19 it can be seen how four sheet metal cutouts are to be cut free by preparatory cutting, so that they can be finally cut free when the sheet 10 is stationary. Sheet metal cutouts 20 can each pair completely from the remaining work piece 11 are cut free, wherein between the final cutting edge of a pair and another pair, the sheet 10 must be moved linearly relative to the cutter only in its transverse direction.

In the case of in FIG. 2 Sheet metal cutouts 12, 15, 18, 19 and 20, which are shown by way of example, each have an identical shape in each case cut together sheet metal cutouts. In principle, however, it is also possible to cut open cut-outs of different shapes together.

FIG. 3 shows the trained as a laser punch press 30 machine tool on which the above method for obtaining sheet metal cutouts is carried out of a metal sheet. The laser punch press 30 has a conventional punching device 31 and a conventional laser cutting device 32 as cutting devices. A sheet metal 33 to be processed is supported on a workpiece table 34 during workpiece machining. By means of a conventional coordinate guide 35, the sheet 33 is displaced in the sheet metal plane with respect to the punching device 31 and the laser cutting device 32. As a result of the movement of the sheet metal 33 relative to the punching device 31 and the laser cutting device 32, the sheet metal area to be processed in each case is displaced into the processing region of the punching device 31 or the laser cutting device 32.

First of all, sheet metal cutouts 36, as described above, are partially separated from a remaining work piece 37 by preliminary cutting, ie, the connection of the sheet metal cutouts 36 with the remaining work piece 37 is cut free, leaving a remaining joint 38. For preparatory cutting, the punching device 31 serves, alternatively or additionally, the laser cutting device 32.

Both the punching device 31 and the laser cutting device 32 can also be used for the final cutting. In this case, the processing area of the punching device 31 is defined by the size of punching tools 39 inserted on it. The processing region of the laser cutting device 32 is essentially determined by the maximum travel paths of a movement unit, not shown, of the laser cutting device 32. By means of the movement unit of the laser cutting device 32, a laser cutting nozzle 40 is moved together with a laser cutting beam, not shown, in the sheet plane with respect to the sheet metal 33 along the cutting lines over relatively small travel paths.

The partially cut-away sheet metal cutouts 36 are positioned for final cutting by means of the coordinate guide 35 in such a way with respect to the punching device 31 or the laser cutting device 32 that their residual connection 38 is located in the processing region of the relevant cutting device.

In the final cutting by punching cutting cuts are created by a cutting edge on a punch on a punching stroke on one of the remaining compounds 38 acts. In this case, the relevant residual connection 38 is severed substantially simultaneously along all the cutting lines. In the case of punching cutting by means of a cutting edge inclined in the stroke direction of the working stroke on a sheared cutting punch, the severing cut is indeed produced along all the cutting lines during a single punching stroke. The severing of the remaining connection 38 between the sheet 33 and the sheet metal cutouts 36 takes place but temporally stretched.

In the final cutting by laser cutting, a cutting cut is made by continuously moving the laser cutting beam along the cutting lines by means of the moving unit, not shown. Consequently, the sheet 33, similar to the punching cut by means of a sheared cutting punch, cut at different locations along the cutting lines offset in time.

The remainder of the connection 38 is positioned in such a way and the sheet cutouts 36 are cut free from the remainder of the work piece 37 by the preliminary cutting so that the sheet cutouts 36, when their remainder connection 38 lies in the working area of one of the cutters, are themselves largely arranged above an opening 41 in the work table 34 ,

The opening 41 can be opened and closed by means of a flap 42. When the flap 42 is open, after the final cutting cut, the completely cut-out sheet metal cutouts 36 fall under gravity from the remaining workpiece 37. The sheet cutouts 36 are removed from the working area of the laser punch press 30 via a flap 42 and a chute 43. A particularly rapid removal of the sheet metal cutouts 36 takes place when the final cutting is performed with the flap 42 open.

As an alternative to the discharge through the opening 41 of the workpiece table 34, the cut-sheet metal cutouts 36 can also be removed from the remaining workpiece 37 by handling devices, not shown, for example by means of a suction frame. Since the final cutting takes place on the stationary sheet, the cut-sheet metal cut-outs can be set before the final cutting on the handling device. For example, nipples of a nipple frame become just before the final one Cutting edges created on the cut-to-cut sheet metal cutouts. Thus, a process-safe removal of sheet metal cutouts is ensured.
Frequently, cut-sheet metal cutouts are also removed manually. For safety reasons, the machine must be stopped completely with every single manual removal. By at least two sheet metal cutouts are cut and removed together, the downtime of the machine can be reduced.

Regardless of the manner of discharging the sheet metal cutouts 36, all sheet cutouts 36 cut free during a final cutting operation are removed from the remaining work piece 37 before the sheet 33 is moved again for subsequent workpiece processing by means of the coordinate guide 35. As a result, an undesired slipping of the cut-sheet metal cutouts 36 with respect to the remaining workpiece 37 is avoided.

The processes described above on the laser stamping press 30 are controlled in a coordinated manner by means of a numerical control unit 44. For this purpose, a stored in the numerical control unit 44 control program is processed.

The control program is created using a programming system. During the generation of the control program, a programming software on which the programming system is based causes later workpiece machining to take place in accordance with the above method. The programming software automatically detects or influences the mutual arrangement of the sheet metal cutouts, the separating cuts in the preparatory and final cutting and the removal process of the sheet metal cutouts, so that sheet metal cutouts are cut and removed together.

Claims (10)

1. A method for obtaining at least two workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) from a plate-like workpiece (1, 10, 33), especially at least two sheet metal cut-outs from a sheet metal panel, wherein by preparatory severance cutting with the workpiece (1, 10, 33) moving, the connection between the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) and the remaining workpiece (3, 11, 37) is partially cut free, i.e. with a residual connection (4, 13, 38) being left, by means of a cutting device (31, 32), wherein after the preparatory severance cutting the residual connection (4, 13, 38) of the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) to the remaining workpiece (3, 11, 37) is cut free along at least one cutting line (7, 14, 16, 17) by means of a cutting device (31, 32) by final severance cutting performed on the stationary workpiece (1, 10, 33), and wherein after the final severance cutting the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) are removed from the remaining workpiece (3, 11, 37), characterised in that the connection between the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) and the remaining workpiece (3, 11, 37) is shortened in the direction of the cutting line(s) (7, 14, 16, 17) of the final severance cutting to a common residual connection (4, 13, 38) by the preparatory severance cutting in such a manner that the remaining common residual connection (4, 13, 38) of the otherwise completely cut-free workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) to the remaining workpiece (3, 11, 37) lies in a working area (5) of the cutting device (31, 32) by means of which the final severance cutting is performed.
2. A method according to claim 1, characterised in that the residual connection (4, 13, 38) of the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) to the remaining workpiece (3, 11, 37) is cut free along the entire cutting line(s) (7, 14, 16, 17) simultaneously by the final severance cutting.
3. A method according to either of the preceding claims, characterised in that the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) are removed from the remaining workpiece (3, 11, 37) by gravity after the final severance cutting.
4. A method according to any one of the preceding claims, characterised in that the preparatory severance cutting and/or the final severance cutting is carried out by punching and/or by laser cutting.
5. A method according to any one of the preceding claims, characterised in that the preparatory severance cutting and the final severance cutting are carried out by means of one and the same cutting device (31, 32).
6. A method according to any one of the preceding claims, characterised in that the residual connection is cut free by the final severance cutting along cutting lines (14, 16, 17) that extend in different directions.
7. A method according to any one of the preceding claims, characterised in that in the final severance cutting operation the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) are disposed over an opening (41) in a workpiece table (34) supporting the workpiece.
8. A method according to any one of the preceding claims, characterised in that the connection between the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) and the remaining workpiece is cut free by the preparatory severance cutting in such a manner that the workpiece cut-outs (2, 12, 15, 17, 19, 20, 36) remain surrounded by the remaining workpiece (3, 11, 37).
9. A method according to any one of the preceding claims, characterised in that the connection between the workpiece cut-outs (12, 20) and the remaining workpiece is cut free by the preparatory severance cutting with a common connecting web (13) being left between the workpiece cut-outs (12, 20) and the remaining workpiece (11), which connecting web (13) forms the residual connection between a plurality of workpiece cut-outs (12, 20) and the remaining workpiece (11).
10. A method according to claim 9, characterised in that the common connecting web (13) between the workpiece cut-outs (12, 20) and the remaining workpiece (11) is cut free by the final severance cutting, and the workpiece cut-outs (12, 20) which have been entirely cut free in that manner are removed from the remaining workpiece (11) simultaneously.

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