Automatic stacking system for sheet metal pressings

Abstract

Automatic destacking system for the systematic packaging of component assortments with high variance and very low cycle times after the pressing process into component-specific carriers, characterized in that the components produced by the press are positively interlocked from the transfer, picked up in stacks on pallets, removed and the component stacks are then systematically positioned in carriers.

Description

Technical field:

[0001] The invention relates to a fully automatic destacking system for components manufactured on transfer presses after the pressing process, wherein these components are stacked systematically onto carriers. The application is particularly suitable for production lines with very short cycle times, where the manufactured components can exhibit a high degree of variance in shape and dimensions. State of the art:

[0002] In transfer presses, workpiece transport between the dies is handled by the press transfer system, which often places the finished components at the press exit onto a continuously running conveyor belt system that removes the workpieces individually. The workpieces are not oriented in a form-fitting manner on this belt, making it suitable for a wide variety of components without any changeovers. Furthermore, these belts are often retractable to ensure access to the press during changeovers. The subsequent removal and packaging of the individual components, which can be done manually or automatically, must be synchronized with the press cycle. Manual handling involves high physical strain on the personnel and requires increased staffing. Automated solutions are often equipped with multiple robots that alternately stack the workpieces and are subject to equally high dynamic loads.Furthermore, the changeover to the next workpiece carrier after filling the previous one must also occur in sync with the press cycle. This is often achieved by using double positions for the workpiece carriers. To meet the high demands of single-cycle operation, component stacks are sometimes formed on the discharge conveyors, which then operate in sync with the press cycle. However, the lack of positive-locking orientation often limits the required speed of stack removal or the stack height. Additionally, the fact that the lower components in the stack rest across the entire width of the machine restricts the accessibility of the component stacks.

[0003] Other solutions for such stacking tasks, such as DE 196 22 916 A1, are only of limited use due to the large space requirement and the lack of quick removal of the assemblies at the press outlet. Purpose of the invention:

[0004] The aim of the invention is to provide a fully automatic system which systematically stacks components with high variance in dimensions and shape into component-specific carriers at the outlet of transfer presses in short cycle times (e.g. < 3 s), requires a minimum of space and resources, and enables the necessary accessibility to the press outlet for setup purposes. Solution to the problem:

[0005] The system according to the invention maintains the positive-locking workpiece orientation present in the press transfer until the components are stacked in carriers. The requirements for the cycle-time-compliant, rapid removal and stacking of the workpieces, as well as the exchange of the carriers, are met by stacking directly at the discharge point of the press transfer and by stack handling during the packaging of the components in carriers.

[0006] The system according to the invention is intended for use at the end of the transfer process of transfer presses (1) and essentially consists of: - a 2-tier stacking and decoupling unit (2) installed in a movable and lockable frame (2-1), with an upper driven feed track (2-2) for empty pallets (2-3), a lift (2-4) located at the loading station directly below the last position of the press transfer for lowering filled pallets, a feed unit for empty pallets (2-5) onto the loading station, a lower driven discharge track (2-6) for filled pallets, another lift (2-7) for lifting the filled pallets at the unloading station, and a discharge unit for empty pallets from the unloading station onto the feed conveyor, a number of pallets with fixtures for stacks of various components in a quick-change design - an automatic loading device (3), such as an articulated robot, with quickly or automatically interchangeable grippers for stacks of different components, and possibly carrier-specific lids or intermediate layers - a conveyor belt (4) for various component-specific goods carriers (4-1), installed below floor level, with a transport track flush with the hall floor, accessible by foot and vehicle, with a loading station for empty goods carriers (4-2), a loading station (4-3) for stacks of workpieces into the goods carriers, and a removal station for full goods carriers (4-4)

[0007] Mode of action: - At the end of the press transfer (1-1), a single workpiece (1-2) or a set of workpieces (1-3) is dropped into the receptacles of a pallet (2-8) waiting at the loading station of the destacking and decoupling unit per work cycle, while maintaining the positive-locking orientation of the components. This process is repeated in the press cycle until the pallet cassette is full. - In the next work cycle, the filled pallet is lowered onto the discharge track (2-6), an empty pallet is pushed from the feed track to the loading station, and the next component or component set is dropped onto it by the press transfer. - On the lower discharge track, the filled pallets are buffered and finally reach the lift (2-7) at the removal point. - If required, a filled pallet is moved from the lift to the upper level of the unloading area. - The loading device / articulated robot (3) uses its component-specific gripper to pick up a stack of components from the pallet and place them at the designated position in a workpiece carrier located at the loading station (4-3) of the conveyor belt. Meanwhile, the lift (2-7) descends, the empty pallet is conveyed to the upper infeed conveyor (2-3), and the next full pallet is moved to the lift position on the lower discharge track (2-6), where it is picked up by the lift (2-7) and lifted into the unloading position. - Once the carrier is filled, it is conveyed away by the conveyor belt (4) and an empty one is provided at the loading station (4-3) of the conveyor belt.

[0008] Advantages: • No need for manual and physically demanding destacking tasks or highly dynamic, possibly doubled, automatic solutions for this, since the component cycle time multiplied by the number of parts in the stack is available, which also applies to the exchange of the goods carriers on the conveyor belt and the pallets at the cassetteting unloading station. • Significantly higher buffer capacity for finished parts before stacking, with the same footprint as in the described state of the art of conveyor systems. • Improved component traceability (e.g., through memory chips on the pallets) and component loading and unloading for testing tasks without affecting the machine cycle time • Due to the form-fitting orientation of the component stacks at the unloading point of the destacking and decoupling unit, no position detection is necessary for component pickup by the robot. • The possibility of designing the mounting for the component stacks on the pallets in a component-dependent manner enables gripping concepts with underhand gripping, which also allows adjacent sets of components to be removed in stacks.

[0009] An embodiment of the invention is described with reference to the Fig. 1, Fig. 2 to Fig. 3 explained.

[0010] They show: Fig. 1 Automatic stacking system in top view Fig. 2 Stacking and decoupling unit in side view Fig. 3 Stacking and decoupling unit in top view Reference symbol list 1 Transfer press 1-1 Press Transfer 1-2 individual workpieces 1-3 workpiece set 2 2-tier stacking and decoupling unit 2-1 mobile frame 2-2 overhead driven feed track for empty pallets 2-3 empty pallets 2-4 Lift for lowering filled pallets at the loading station 2-5 Feed unit for empty pallets 2-6 bottom discharge lane for filled pallets 2-7 Lift for lifting the filled pallets at the unloading point 3 Automatic charging device / articulated robot 4 Conveyor belt for goods carriers 4-1 component-specific product carrier 4-2 Loading station for empty goods carriers 4-3 Loading station for workpiece stacks in goods carrier 4-4 Picking station for full product carriers QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 196 22 916 A1

[0003]

Claims

[1] Automatic stacking system for the systematic packaging of component assortments with high variance and very low cycle times after the pressing process into component-specific carriers, characterized by , that the components produced by the press are transferred in a form-fitting manner, picked up in stacks on pallets, removed and the component stacks are then systematically positioned in goods carriers. [2] Stacking and decoupling unit, 2-tier, mobile and lockable, with an upper infeed track for empty pallets, pallets with quick-change fixtures for stacks of various components, a lower discharge track for filled pallets, a lift for lowering filled pallets at the loading station via the press transfer, another lift for raising the filled pallets at the unloading station, as well as a feed unit for empty pallets to the loading station and a discharge unit for empty pallets onto the infeed track at the unloading station. The unit is in particular characterized by , that the feed unit and lift at the loading station work together in such a way that the filled pallets are exchanged for empty pallets in the press cycle. [3] Stacking and decoupling unit according to claim 2, but with a lower feed track and an upper discharge track and a correspondingly adapted operating principle [4] Stacking and decoupling unit according to claim 2, but with feed and discharge tracks arranged side by side on one plane, transverse displacement tracks instead of lifts and a correspondingly adapted operating principle

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