EP1472025B1 - Method for operating a plate feeding system for stamping presses and plate feeding system for carrying out said method - Google Patents

Description

The invention relates to a method for operating a panel system for punching presses according to the preamble of patent claim 1 and a panel system for stamping presses according to the preamble of claim 12.

Panel systems serve to feed sheets of, for example, aluminum, positioned to a punch press which punches a predetermined number of blanks from the sheet. From the generic EP 0 539 669 For example, a panel system has become known in which first gripping means detects a panel in a transient position on opposite sides. In the transition position, the panel is brought by second gripping means which engage the rear edge of the panel. The transfer position corresponds to a position of the panel in which the punch performs a first punching stroke on the panel. The master carriage having the second gripping means brings the panel only in the transfer position when the first gripping means have reached their receiving position along both axes. The first gripping means are adjustable along two orthogonal axes, so that an offset division of the surfaces to be punched can be selected for the purpose of favorable material utilization. The transfer of the panel in the transfer position to the first gripping means takes place, as mentioned, during the first punching cut, during which the panel is fixed by the punching tool. After the end of the processing of the preceding panel, both axes of the feed for the first gripping means and the feed carriage move to the home and pickup positions in which a new board is picked up. With the aid of the panel system described above, the transitional time for the panels can be significantly reduced as the press continues to move. Preceding panel and the first punching step of the following table. This could possibly be avoided by the cutting ring is lowered. The achievable benefit, however, comes with positioning errors by pulling down the panel at the last cut.

At the last stroke of the known system, one of the two feed pliers is directly on one of the outer tools. If you want to ensure that the upper edge of the lower forceps jaw forms a plane with the cutting ring so that the panel is not pulled around during the last stroke, the pliers will be in a specially shaped pocket of the lower cutting ring for smaller cutting diameters (<100 mm). The newly inserted board must be pushed under the feed pliers. However, this can only be done when the pliers have moved back a sufficient distance to leave enough space for the incoming table. The leading edge of the board to be retracted must be raised to the height of the cut ring. Even if larger pockets do not require pockets in the cut rings, it is difficult for the then thicker sheets to pass between pliers and cut ring. The release of the gap between the pliers and cutting ring can also be done by lifting the pliers. However, this process takes time. There is also known a panel system in which the tongs engage the rear panel edge. But even with this constellation, the grippers are the last stroke in an identical position to a cutting ring as in the system described above. A closer look at the attack at the rear edge shows, however, that when feeding diagonally in a row change only the sliding forceps acts. This leads to a punctual initiation of the acceleration and to a diagonal wave formation, which takes a very long time until it has passed through the entire panel. Only when the board is flat again, can be accurately punched. A dynamic operation is from the moment of the beginning of the shaft ends. A dynamic operation is no longer possible from the moment of the start of the wave motion. The problem occurs especially at the beginning of the table processing, when the panel is still full size and the distance between the pliers to the tool is maximum.

The punch press runs as fast as the feed allows. But then there is no time left for the board for extra actions like raising or going away. This time thus leads to a reduction in the possible speed of the press and thus to a reduction in the performance of the entire system. The same applies to all known panel feed systems.

As already mentioned, the known gripping means are formed by pliers. Above all, when operating with panels made of chromed sheet steel, there is a rapid wear of the pliers. The chrome crumbles on the edges of the board and leads to incorporations in the pincer mouths. Wear also takes place in the joints for the pliers. Since the pliers have to build small, only structurally simple bearings can be provided, which further increases the wear.

When punching out the last row, the stability of the residual grid usually collapses because the remaining sheet metal parts only hang in bars and thus are only conditionally connected to the collets. This leads to dimensional deviations with respect to the position of the panel in the tool.

Out EP 0 242 588 A3 a transport and sorting device for a computer-controlled angle scissors has become known, are detected in the metal plates with magnetic or designed as suction cups grippers. The Grippers are attached to overhead conveyors. With the help of such a device sheet plates can not push through a press.

Out DE 0 582 093 A1 is a Platinenzuführeinrichtung for a press become known, in which a transverse conveyor is provided with a carriage and a lifting unit and a suction spider attached thereto. With the latter, the boards are unstacked from the respective stack of boards and transferred in a receiving station to a longitudinal conveyor. The longitudinal conveyor includes two slides movable in opposite directions. The first carriage carries an upwardly directed suction spider and is mounted below the transport plane. The first carriage exceeds the path from the pickup station to a transfer station where the first carriage and the second carriage overlap. The second carriage exceeds the path from the transfer station to a delivery station. He wears a downward suction spider. Even with such a device sheet plates can not move through a press.

The invention has for its object to provide a method for operating a panel system for stamping presses and a panel system for stamping presses, which avoids any idle stroke at high press speed, allows stable guidance of the panel and allows a nearly wear-free operation.

This object is solved by the features of patent claims 1 and 12, respectively.

In the method according to the invention for feeding first connecting means with gripping portions on a bar grasp the panel exclusively from the rear edge portion of a panel, wherein the edge portion between the rear edge and the auszustanzenden surfaces of the last row of surfaces, based on the feed direction is located. The areas to be punched out should be understood here as the last row of surfaces to be punched out, relative to the feed direction.

The detection of the rear edge region by means of the first connecting means can take place in various ways. An embodiment of the invention provides that the connecting means detect the rear edge region by means of vacuum. Another possibility according to the invention is that the connecting means detect the rear edge region electromagnetically.

The detection of the rear edge region with vacuum and / or electromagnetically leads to a frictional connection between the connecting means and the panel. In order to improve the entrainment possibility, an embodiment of the invention provides that the connecting means engage the panel by means of pointed projections which penetrate into the rear edge region of the panel when the connecting means engage the edge region. As a result, a positive connection between the connecting means and the panel is produced.

The projections of the first connecting means may be formed by needle-like domes which penetrate into the panel, wherein according to one embodiment of the invention, the dome may be arranged in suction openings of vacuum nozzles. At the moment when the panel is pressed against the nozzle, a spike of the nozzle completely or partially penetrates into the panel. Even with twice cold-rolled steel, the domes can support the panel of e.g. Penetrate 0.18 mm thickness.

The connecting means are mounted on at least one bar, which engage with the gripping portions in the gusset, which between the rear edge of the panel and the surfaces to be punched are formed. For example, the strip may have one or more suction ports connected to a vacuum source.

To engage connecting means and panel it is necessary that either the connecting means make a lifting movement to be lowered against the panel and then raised again so that the panel is advanced in the cutting plane. Alternatively, it is also possible to keep the connecting means constant in height and instead to lift in the transfer position the panel or the rear end of the panel to make the force or positive engagement with the first connecting means.

In the method according to the invention, areas of the panel which are not punched out are used for the detection with the connection means. Usually, the panels in question are those which leave open spaces between the mostly round or non-rectangular shaped cuts and the rear edge. These open spaces are used in the invention for detecting and moving the panels.

The invention also has the advantage that a panel is not pulled around at the last punching cut, but instead the preceding panel can be withdrawn to the rear and a new panel can be easily inserted thereunder from a feed slide.

The method according to the invention can be used for all known sheet feed systems. It is applicable to panel systems that use a document carriage that transports the panels from an alignment station to a transfer station in which it is detected by the connecting means of the feed carriage and advanced to the punch press. The invention can also be used for so-called four-axle systems in which the feed carriages bring the sheets directly from the alignment station and feed them to the punch press. In this case, two feed slides are provided, which alternately advance the detected sheets to the punch press. It is essential in all template systems, if they use the inventive method that the next following panel is inserted without a free stroke in the punch press without the speed of the press must be reduced compared to their possible punching speed or other precautions are taken to a time delay to avoid when inserting the next panel after punching the last row of openings of the previous panel.

The time required in the inventive method for receiving or taking over a board is extremely short and allows the elimination of any idle stroke, without reducing the speed of the press.

Another advantage of the invention is that better guidance is possible over the way the panel is detected, especially if the panel is large and thin. When fixing the panel according to the invention, the force can be introduced over the entire panel width and wave movements or the like can be avoided in dynamic operation. Thus, considerably larger accelerations and higher powers are possible.

Finally, the advantage is obtained that the stability of the residual lattice is significantly higher than in known processes by the detection of the panel according to the invention. Dimensional deviations that can occur due to the collapse of the skeleton components are avoided.

Fig. 1

zeigt eine Draufsicht auf ein schematisch dargestelltes Tafelanlagesystem mit Mitteln der Erfindung während der Übergabe von einem Vorlageschlitten auf eine Vorschubvorrichtung.

Fig. 2

zeigt eine ähnliche Darstellung wie Fig. 1 mit einer Tafel am Ende der Verarbeitung.

Fig. 3

zeigt einen Schnitt durch die Darstellung nach Fig. 1 entlang der Linie 3-3.

Fig. 4

zeigt die Ansicht 4 gemäß Fig. 1.

Fig. 5

zeigt die Ansicht 5 gemäß Fig. 2.

The invention will be explained in more detail with reference to an embodiment.

Fig. 1

shows a plan view of a schematically illustrated panel system with means of the invention during the transfer of a feed carriage to a feed device.

Fig. 2

shows a similar representation as Fig. 1 with a blackboard at the end of processing.

Fig. 3

shows a section through the illustration Fig. 1 along the line 3-3.

Fig. 4

shows the view 4 according to Fig. 1 ,

Fig. 5

shows the view 5 according to Fig. 2 ,

In the Figures 1 and 2 is denoted by 10 a punching press of conventional design. It has three punching tools 12 which are moved by means of a plunger perpendicular to the plane of the drawing. A feed carriage 16 is adjustable along a guide 18 in the direction of the double arrow 20. The feed carriage 16 has holders 22, 24 for a gripping bar. 25 as the first connection means. The structure of the strips 25 will be discussed in more detail below. Carriage 16 and holder 22, 24 are actuated by suitable adjustment drives, not shown, which in turn are controlled by a suitable control device.

A master slide 30 (only in Fig. 1 shown) with two collets 32, 34 as the second connecting means is adjustable along a slide guide 36 in the direction of the double arrow 38. The drive for the carriage 30 is also not shown. However, it is a non-positive detection by the master slide conceivable, for example, by magnetic force or vacuum.

The collets 32, 34 may be conventional structure, for example, have a rigid jaw 35 as a lower jaw and a movable jaw 37 as the upper jaw, wherein the movable jaw 37 is actuated by a suitable, not shown drive (see Fig. 3 ).

Like from the Figures 1 and 2 As can be seen, the ledge 25 is contoured such that it engages with portions in the gussets formed between the surfaces to be punched out of the respective rear row and the rear edge. The bar 25 is located above the panel 40a and 40 respectively. In cross section, it is in the FIGS. 4 and 5 shown.

In the FIGS. 4 and 5 can be seen on the underside of the bar a recess 50 to which a line 52 is guided via a suitable connector 54, not shown. The line 52 is connected to a vacuum source, not shown, so that the recess 50 is under negative pressure. With the help of a negative pressure, therefore, the panel 40 or 40a can be held by the bar 25.

Centered in the recess 50, a needle-like mandrel 56 is arranged. If the panel 40 or 40a held against the bar 25, the mandrel 56 penetrates into the material of the panel 40a and 40, so that the panel is also held positively. In this way, the panel 40a or 40 can be advanced in the desired manner to the press 10 with the aid of the feed carriage 16.

The bar 25 may include a plurality of such in the FIGS. 4 and 5 illustrated connecting means to securely grasp the panel 40a and 40 over a large width.

In terms of FIGS. 4 and 5 It should be noted that, in reality, the rear edge of the panel ends much closer to the tool than shown. A measure of 1 mm between edge and cut is common. After that, the fixation shown is then not in front of, but between the upper tools.

Fig. 2 shows a panel 40 to be processed in a position in which the last punching step is carried out. Once the punches 12 are engaged with the panel 40, the ledge 25 can be disengaged from the panel or skeleton, for example, by switching from vacuum to compressed air. The feed carriage 16 returns to a transfer position, as in Fig. 1 is shown. During this time, the collets 32, 34 have already detected a new panel. Has the bar 25 reaches its position along the transverse axis 21, the receiving position on this axis is also reached. Thus, while the document carriage 30 advances the new board 40a along the longitudinal axis 20 in the direction of the punch press 10, the strip 25 moves due to the return movement of the feed carriage 16, the board 40a being pushed freely into the press 10. The transfer position corresponds to the position in which the punching tools 12 perform the first cut. The master slide 30 can easily advance the next succeeding sheet below the processed sheet as shown in FIGS FIGS. 4 and 5 results. One recognizes the tabletop 60 on which the tablet is advanced. Has the board according to Fig. 4 (Table 40a) reaches the transfer position, it is raised by means of at least one lifting ram 62, which is actuated by a lifting drive, not shown in the direction of the double arrow 64, against the underside of the bar 25 so that the mandrel 56 can penetrate the panel 40a. The stamp 62 extends through an opening 66 of the table top and is zurückverstellt immediately after the stroke back to the starting position. Now, the feed carriage 16 in the manner described advancing the board to the punch press to the execution of the last cut, as in Fig. 5 shown. Fig. 5 shows an upper tool 68 and a lower tool 70 of the punching tools 12. The underside of the bar 25 corresponds exactly to the cutting plane of the tools 68, 70th

A lifting of the panel - at least over a partial width - can also take place by means of a lifting of the master carriage.

At the moment in which the punching tools 68, 70 cut the board 40a and thus simultaneously fix, the collets 32, 34 are opened and the punch 62 lifts the board 40a against the strip 25 (FIG. Fig. 4 ), whereby the transfer from the feed carriage 30 to the feed carriage 16 takes place.

With the principle shown, the feed of the panels without empty strokes of the punch press can accomplish. The panels 40 and 40a are reliably detected by the bar 25 with the connecting means shown, so that deformations of the panels due to the feed movements do not occur. Due to the wide-area detection of the panels in the rear edge area, stabilization of the residual grid also takes place during the last punching step.

The skeleton may be removed from the ledge 25 e.g. be solved in that on the nozzles 50, a pressure surge is generated, which moves the skeleton grid down.

Claims (17)

1. A method for the operation of a panel placement system for punching presses (10) wherein a feed slide (16) is moved between the punching die (12) of the punching press (10) and a transfer position located in front of the punching press (10), wherein first connection means of the feed slide (16), in the transfer position, seize a panel (40, 40a) in the rear area to advance it stepwise through said punching press in response to the cycle of said punching press (10), which punches out a respective row of spaced surfaces, characterized in that said first connection means, with gripping portions (50, 56) at a ledge (25), engage in a wide area and seize said panel (40, 40a) exclusively from above in gores of the rear edge area of a panel, wherein the edge area is located between the rear edge and the surfaces to be punched out in the respective last row with respect to the advance direction.
2. The method according to claim 1, characterized in that said feed slide (16) is guided by a slide guideway (18) and is moved along a first axis (20) towards said punching die (12) and away therefrom to a pick-up position, wherein said first connection means further are guided by the feed slide (16) and are preferably dislocated along a second axis (21) perpendicular to the first axis (20), and wherein an advancement slide (30) having releasable second connection means is dislocated along the first axis (20) to feed a panel (40, 40a) to a transfer position for a take-over by said first connection means with one panel (40, 40a) being seized by said first connection means from above at the rear edge area during a punching step of the punching press (10) in the transfer position which corresponds to the panel position for the first punching step of said punching press (10) and the advancement slide (30) brings a succeeding panel into the transfer position when said first connection means have reached their take-over position along the two axes (20, 21).
3. The method according to claim 1, characterized in that two feed slides (16) are guided by a slide guideway (18) each and are dislocated along a first axis (20) between said punching die (12) of said punching press (10) and a transfer position, wherein said first connection means further are guided by the respective feed slide and are preferably dislocated along a second axis (21) perpendicular to the first axis (20).
4. The method according to any one of claims 1 to 3, characterized in that said connection means seize the rear edge area via a vacuum.
5. The method according to any one of claims 1 to 3, characterized in that said connection means seize the rear edge area electromagnetically.
6. The method according to claim 2, characterized in that by means of said second connection means each succeeding panel is advanced below said first panel (40, 40a).
7. The method according to any one of claims 1 to 6, characterized in that the rear edge area of the panel (40, 40a), when received, is lifted against said connection means.
8. The method according to any one of claims 1 to 6, characterized in that said first connection means carry out a lowering and lifting motion to seize the rear edge area of the panel (40, 40a).
9. The method according to claim 7, characterized in that said panel or said rear edge area of the panel (40, 40a) is lifted by separate lifting means against said first connection means.
10. The method according to any one of claims 1 to 9, characterized in that said first connection means seize the panel in a positive fit by means of pointed projections (56) which penetrate into the rear edge area of the panel (40, 40a) when said connection means have seized said edge area.
11. The method according to any one of claims 1 to 10, characterized in that said connection means and the remaining grid are separated from each other by means of a gas beam.
12. Panel placement system for punching presses having a feed slide (16) being moved between a punching die (12) of the punching press (10) and a transfer position located in front of the punching press (10), first connection means of the feed slide (16) for seizing a panel (40, 40a) in the rear area, a drive means for the feed slide (16) and a control means for the drive means and the first connection means, characterized in that the first connection means comprise at least one ledge (25) with gripping portions (50, 56) being configured and arranged to engage gores of said rear edge area of a panel (40, 40a) from above which are defined between the panel surfaces to be punched out and said rear edge.
13. Panel placement system according to claim 12, characterized in that said ledge (25) is coupled to a vacuum source and has at least one suction port (50) at the underside.
14. Panel placement system according to claim 12, characterized in that said ledge (25) has one or more electromagnets to seize the panel from above.
15. Panel placement system according to any one of claims 12 to 14, characterized in that said ledge (25) has relatively sharp projections (56) at the underside, which penetrate into the material of said panel or a coat covering said panel when said connection means are in engagement with said rear edge area.
16. Panel placement system according to claim 15, characterized in that pin-like spikes are provided as projections (56) which penetrate through said panel.
17. Panel placement system according to claim 16, characterized in that said spikes are disposed within the suction ports (50) of vacuum nozzles.

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