SHEET METAL PRESS SYSTEM AND METHOD USED IN CONNECTION THEREWITH

Abstract

The invention concerns a sheet metal press system and a method used in connection therewith. The sheet metal press system comprises at least one sheet metal press having an opening through which a tool, which comprises an upper die, a lower die and a tool changer interface, can pass during a tool change performed by means of a tool changer device. The tool changer device comprises at least one automated guided vehicle, running on a shop floor and capable of lifting and lowering a tool by interaction with the tool changer interface of said tool, wherein a guide path for said at least one automated guided vehicle runs from outside and into said at least one sheet metal press through said opening. The method comprises alternating use of a first and a second automated guided vehicle during a tool changing operation.

Claims

1. Sheet metal press system comprising at least one sheet metal press having an opening through which a tool, comprising: an upper die, a lower die and a tool changer interface, can pass during a tool change performed by means of a tool changer device, characterized in that the tool changer device comprises at least one automated guided vehicle, running on a shop floor and capable of lifting and lowering a tool by interaction with the tool changer interface of said tool, and that a guide path for said at least one automated guided vehicle runs from outside and into said at least one sheet metal press through said opening.

2. Sheet metal press system according to claim 1, wherein said tool changer device comprises two alternatingly operated automated guided vehicles for each sheet metal press of the sheet metal press system.

3. Sheet metal press system according to claim 1, wherein each automated guided vehicle comprises a tool docking bay, into which a tool fits.

4. Sheet metal press system according to claim 3, wherein said docking bay comprises two parallel forks, having projecting dogs along sides facing each other, said dogs being capable of interaction with slots running along sides of the tool changer interface of a tool.

5. Sheet metal press system according to claim 4, wherein said dogs are liftable and lowerable in relation to said forks.

6. Sheet metal press system according to claim 1, wherein said tool changer interface forms an integral part of the lower die of a tool.

7. Sheet metal press system according to claim 1, wherein said tool changer interface comprises a bolster on which the lower die of a tool rests.

8. Method used in connection with a sheet metal press system according to claim 1, characterized by the steps of using a first automated guided vehicle in a storage place to pick up a stored first tool, which comprises an upper die, a lower die and a tool changer interface, and to move the picked up first tool to a sheet metal press, of using a second automated guided vehicle in said sheet metal press to pick up a used second tool, which comprises an upper die, a lower die and a tool changer interface, and to move the picked up second tool out of the sheet metal press, of moving the picked up first tool into the sheet metal press by means of the first automated guided vehicle, of putting the picked up first tool down inside said sheet metal press, and of moving the first automated guided vehicle out of said sheet metal press.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the drawings an embodiment of the sheet metal press system and the method according to the present invention is presented in a consecutive series of schematic perspective figures enumerated 1 to 14.

DESCRIPTION OF AN EMBODIMENT

[0014] In FIGS. 1-14 identical reference numbers are used to depict identical features. Further, reference numbers are used only where appropriate for explanatory purposes and are therefore not repeated in every figure.

[0015] In FIGS. 1-14 an identical portion of a pressing plant 1 is shown. It comprises a shop floor 2, on which an arbitrary number of identical sheet metal presses 3-7 are arranged in a row.

[0016] Each sheet metal press 3-7 has side openings, of which only a left side opening 8 and a right side opening 9 of the first sheet metal press 3 are depicted. The remaining sheet metal presses 4-7 have corresponding ones.

[0017] The side openings 8, 9 are used in a well-known manner during production to move work-pieces (not shown) into and out of each sheet metal press 3-7. Besides the side openings 8, 9 each sheet metal press comprises front and rear openings as well, of which only a front opening 10 and a rear opening 11 of the first sheet metal press 3 are depicted.

[0018] Inside each sheet metal press 3-7 there is a press chamber 12 (only the one in sheet metal press 3 is depicted), which is accessible through the side, front and rear openings 8-11. At the bottom the press chamber 12 is limited by a floor 13, which is in level with the shop floor 2, and at the top of a superstructure 14. The superstructure 14 is carried by four pillars, of which only the three visible ones 15-17 of sheet metal press 3 are depicted.

[0019] The superstructure 14 of each sheet metal press 3-7 does in a well-known and therefore not further described and shown way comprise at least one press cylinder, which for instance can be driven hydraulically and moves a press piston up and down during press operation.

[0020] During press operation the press piston is firmly connected to a press tool arranged inside the press chamber 12. In FIGS. 1-14 only press tools related to the press chamber 12 of the first sheet metal press 3 are depicted with reference numbers 18a and 18b and to some extent described, but their general structure is alike. Thus, each press tool 18a, 18b comprises a top die 19, which during press operation is moved up and down by at least one press piston, a bottom die 20 and a bolster 21, which carries the bottom die 20 and during press operation rests on the floor 13 of the press chamber 12.

[0021] Depending on a product to be produced by means of a sheet metal press 3-7, different press tools 18a, 18b are used. Hence, from time to time production has to be stopped and a tool change has to be performed. That situation is illustrated in FIGS. 1-14, which is why in these figures the at least one press piston mentioned above is disconnected from the upper die 19 of any press tool 18a, 18b inside any press chamber 12 and therefore not visible.

[0022] From a production point of view it is important both to minimize time of a tool change and to render tool change as flexible as possible in order to be able to cope with unexpected situations, such as a production change at short notice. Against that background, according to the present invention automated guided vehicles, so-called AGVs, come into play. In the figures two such AGVs are shown, a first one enumerated 22a and a second one enumerated 22b.

[0023] An AGV 22, 22b is self-propelled and usually runs directly on a shop floor. It is electronically controlled to follow a guide path exactly to an indicated destination. A guide path is usually not visible as it is defined by means of GPS-signals, optical way points, such as mirrors, and/or inductive means, such as an electrical cable embedded in a floor, which is why no paths are visible or depicted in FIGS. 1-14. The technique, however, is well known, and a person skilled in the art would therefore have no difficulties to apply the technique in the pressing plant 1 at hand.

[0024] The AGVs 22a, 22b shown in the figures are identical, which is why details of them are described in connection with appropriate figures only and unnecessary iterations of reference numbers are avoided generally.

[0025] In FIG. 1 all sheet metal presses 3-7 have been stopped and their press tools, such as press tool 18a of press 3, have their upper die 19 disconnected from the at least one press piston and resting directly on the lower die 20, whereas the lower die 20 in its turn is resting on the bolster 21 on the floor 13 of the press chamber 12. In front of the row of sheet metal presses 3-7 two AGSs 22a, 22b are shown on their way towards the first sheet metal press 3. The first AGV 22a carries a press tool 18b, which is a new or second tool intended to replace the old or first press tool 18a inside the first sheet metal press 3. The second AGV 22b is empty and does, as shown, preferably run in reverse compared to the first AGV 22a in order to shorten the distance travelled during a tool change.

[0026] In FIG. 2 the first AGV 22a has just passed the first sheet metal press 3 and the second AGV 22b arrived at it. The second AGV 22b, clearly shown in the center of FIG. 2, comprises two parallel forks 23, 24, which in-between define a tool docking bay 25. Both forks 23, 24 have on their sides facing each other dogs 26 (only the ones of fork 23 are visible, but the ones of fork 24 are alike), which are liftable and lowerable in relation to the forks 23, 24. The dogs 26 are capable of interaction with corresponding slots 27 running along sides of the bolster 21 of a press tool 18a, 18b. One such slot 27 is depicted on the bolster 21 of tool 18a in FIG. 1. A parallel one, however hidden in the figure, is arranged on the bolster 21 on the other side of the tool 18a.

[0027] Now, as shown in FIG. 3, the second AGV 22b has turned towards the first sheet metal press 3 and is aligned with the front opening 10 of the sheet metal press 3. In the next step shown in FIG. 4, the second AGV 22b has moved into the first sheet metal press 3 through the front opening 10 and has run its forks 23, 24 along sides of the bolster 21 of tool 18a such that dogs 26 are inserted into the slots 27 of the bolster 21.

[0028] The next operational step is shown in FIG. 5 and comprises only of lifting tool 18a off the floor 13 of the press chamber 12 by lifting the dogs 26, which are engaged with said slots 27.

[0029] In FIG. 6 the second AGV 22b has moved the first press tool 18a through the front opening 10 out of the first sheet metal press 3. In FIG. 7 the second AGV 22b has turned away from the first sheet metal press 3 and the first AGV 22a, which is still waiting.

[0030] In FIG. 8 the second AGV 22b has moved further away and is on its way for instance towards a maintenance station, whereas the first AGV 22a has started to approach the first sheet metal press 3.

[0031] In FIG. 9 the first AGV 22a has turned towards the first sheet metal press 3 and has aligned itself with the front opening 10 of the sheet metal press 3.

[0032] In the next step shown in FIG. 10, the first AGV 22a has moved into the first sheet metal press 3 through the front opening 10.

[0033] In FIG. 11 the first AGV 22a has by lowering its dogs 26 let the second press tool 18b down on the floor 13 inside the first sheet metal press 3.

[0034] And, finally, in FIGS. 12-14 a sequence is shown in which the first AGV 22a in an empty state moves out of the first sheet metal press 3 and runs off along the row of sheet metal presses 3-7 for instance towards a press tool deposit.

[0035] A person skilled in the art realizes that the preferred embodiment described above can be altered in different ways within the scope of the appendant claims and that for instance the layouts of a sheet metal press, a tool or an AGV can differ. However, the number of AGVs may differ as well. Thus, in order to maximize tool change speed, it is preferred to provide two AGVs per sheet metal press.