DE20020855U1 - Transfer device for large press system - Google Patents

Description

GRÜNECKER KljMl^kEj&Y ^TÖgkMjM8!:& SWAN HOUSES

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GKS 5 S MAXIMIUANSTRASSE 58 D-80538 MUNICH GERMANY

Applicant:

BLECHFORMWERKE BERNSBACH GMBH

STREET OF UNITY 45/47 08315 BERNSBACH

YOUR REF.

LAWYERS PATENT ATTORNEYS PATENT ATTORNEYS LAWYERS EUROPEAN PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS MUNICH MUNICH COLOGNE DR. HELMUT EICHMANN OR. HERMANN KINKELDEY DR. MARTIN DROPMANN GERHARD BARTH PETER H. JAKOB DR. ULRICH BLUMENRÖDER, LLM. WOLFHARD MEISTER CHEMNITZ CHRISTA NIKLAS-FALTER HANS HILGERS MANFRED SCHNEIDER DR. MAXIMILIAN KINKELDEY, LLM. DR. HENNING MEYER-PLATH SONJA SCHAEFFLER ANNELIE EHNOLD BERLIN DR. KARSTEN BRANDT THOMAS SCHUSTER DIETER JANOER MICHAEL J. FRANKE, LLM. DR. KLARA GOLDBACH UTE STEPHANI MARTIN AUFENANGER DR. BERND ALLEKOTTE, LLM. GOTTFRIED KLITSCH DR. HEIKE VOGELSANG-WENKE OF COUNSEL REINHARD KNAUER PATENT ATTORNEYS DIETMAR KUHL DR. FRANZ-JOSEF ZIMMER AUGUST GRONECKER BETTINA K. REICHELT DR. GUNTER SEZOLD DR. ANTON K. PFAU DR. WALTER LANGHOFF DR. UDO WEIGELT RAINER BERTRAM JENS KOCH, M.S. (U of PA) M.S. BERND ROTHAEMEL DR. WILFRIED STOCKMAIR OR. DANIELA KINKELDEY (-1996) DR. EN /OUR REF. DATE

G4431-25/SÜ 08.12.00

Transfer device for large press system

GRÜNECKER KINKELDEY STOCKMAIR & SCHWANHÄUSSER MAXIMIUANSTR. 58 D-80538 MUNICH GERMANY

PHONE +49 89 21 23

FAX (GR 3) +49 89 22 02 87 FAX (GR 4) +49 89 21 8&oacgr; 92 93 ^•ktpVA/rww.erwneckef.cle ·· ·» ··

e-*naU: pcstmaÄer@grLme«:kei»de ·· ··

DEUTSCHE BANK MUNICH No. 17 51734
Bank code 700 700 10
. SVV ₁ IFT: pEUT DE MM

Transfer device for large press system

The invention relates to a transfer device of the type specified in the preamble of claim 1.

In high-performance press systems, especially in the automotive industry, automated work processes are state of the art. When pressing outer skin parts, especially parts with low inherent stability, each workpiece is picked up and stabilized from above using suction frames. The workpiece is transferred in press lines with transfer devices that have two- or multi-axis feeders or robots. In suction beam presses, centrally or decentrally driven two-axis transfer devices, possibly with additional axes, are used. When pressing structural parts with high inherent stability, each workpiece is picked up from the side using shovels or grippers. In press lines, transfer devices with three-axis transfer systems are provided for this purpose, which manipulate the workpieces along the press (transfer presses) or across the press (large-part step presses). The transfer devices are specially tailored to the respective type of automation. Feeder devices with at least two axes are arranged approximately in the middle in front of and behind the press. Transfer systems for cross transport each have two drive units to the right and left of the press with support rails that are stored in two support points. The pressing tools for this large number of automated press systems are specially designed or tailor-made. For example, the tool guides and slides are arranged differently, i.e. in automatic feeder systems they are located to the left and right of the workpiece flow, while in three-axis transfer operation the guides are arranged in the middle and free spaces are provided to the right and left of the workpiece flow. The differences in the automatic systems require a large number of systems in the plant for optimal production of the pressed workpieces. For example, if a manufacturer taking over tools from the original manufacturer is taken over by a manufacturer taking over, the manufacturer taking over has to use the type of automation for which the tools were originally developed for the automated production of the workpieces in its plant.

The invention is based on the object of creating a transfer device that makes it possible to use tool sets that have been specially developed for different types of automation effectively in just one press system, regardless of the type of automation. This is based on two feeder systems arranged in front of and behind the press with three NC axes for automated longitudinal or transverse movement of the workpieces. The desired effective operation of the tool sets requires that the transfer device is able to cope with fast stroke cycles or high stroke cycle frequencies.

Thanks to its lightweight construction made of continuous carbon fiber reinforced plastic (CFRP), each of the feeder beams used in pairs is extremely rigid and therefore resistant to bending and torsion, even with a length of over 3 m and up to 7 m and more, and is extremely light. The feeder beam is deliberately designed with a natural frequency of more than 20 Hz, so that high stroke cycle frequencies or fast stroke cycles are possible and the transfer device is highly efficient. The fact that the feeder beam is only clamped on one side and cantilevers over its course without support not only saves a second linear feeder or additional supports with their motion guides for the other end of the feeder beam. The introduction of force from the transfer tools attached to the feeder beam via the gripper rail is improved by the integrated light metal inserts, so that the required transfer tools can be easily attached to the feeder beam. The transfer device lowers the profitability threshold of the entire press system. Furthermore, the investment costs are significantly lower than with known transfer devices. Another advantage is the flexible adaptation to different tools in conjunction with reduced set-up times and, what is particularly important, fast stroke cycles or high stroke cycle frequencies, where no disturbing vibrations occur due to the high natural frequency of the feeder beam. Despite the fact that each feeder beam is only clamped on one side, these advantages can surprisingly be achieved with the box profile lightweight construction concept made of continuous carbon fiber reinforced plastic with integrated force introduction inserts.

Two alternative embodiments are advantageous. For the automated transfer, two linear feeders are arranged in front of and behind the press, each of which has three

controlled NC axes. If the press tools or the press require longitudinal movement of the workpieces, then a straight, freely cantilevered feeder beam is attached to each linear feeder. If the tools require transverse movements, then a T or TT feeder beam is attached to each linear feeder. The transfer device can be supplemented with further, smaller, flexible feeder systems, for example to feed circuit boards or remove any parts. In one embodiment, the straight feeder beam essentially extends the clamping point on the linear feeder. It extends freely cantilevered lengthwise over the press table. The gripper rail can be specially designed for the respective application. To transport parts between the tool stations of a single press or a press line, both feeder beams are moved synchronously in pairs along the press table by their two linear feeders. In the other embodiment, the feeder beam extends transversely in front of its linear feeder, whereby it is moved transversely in a single press station or in the press line. Thanks to its integrated at least one trunk, this feeder beam forms a T- or TT-shaped structure and extends to both sides starting from the trunk or both trunks.

Particularly with a long feeder beam, it can be useful to provide two adjacent logs to avoid torsion in the log and to secure them at two clamping points or a widened clamping point on the linear feeder. In this way, a π-shaped structure is formed. This enables feeder beam lengths of up to 7 m and more to be achieved, which, despite their length and due to the high natural frequency, can tolerate fast lifting cycles and high lifting cycle frequencies.

In the embodiment with one or two logs, the feeder beam can be set higher or lower than the clamping point on the linear feeder, with a cranking of the log compensating for the height offset.

The high-strength lightweight construction is characterized by vertically spaced, flat upper and lower chords, which are connected to each other in a rectangular cross-section with side walls, with each chord having edge and bending moment-resistant

Correctly designed CFRP strips with longitudinal fibers are provided in the corner areas of the rectangular cross-section, between which there is a sandwich profile, preferably with a light and dent-resistant honeycomb structure. The side walls are formed by C-profiles made of CFRP that extend under the CFRP strips. The high rigidity and torsional strength are achieved with extremely lightweight construction.

The bending moment-appropriate design of the feeder beam with at least essentially constant belt width can be achieved by a horizontal thickness of CFRP strips integrated into the belts that decreases in the direction of the free end of the feeder beam. The decrease in thickness can be gradual or step-by-step. In the feeder beam that extends the clamping point essentially linearly, the thickness of the CFRP strips decreases successively up to the free end of the beam. In the feeder beam that is connected to at least one trunk and the insertion point via a node, the horizontal thickness of the CFRP strips decreases from the node in the direction of each free end of the feeder beam.

The feeder beams can be manufactured cost-effectively and tailor-made from prefabricated individual parts, e.g. the belts and the side walls, whereby thermosetting adhesive areas and/or inserts can be used for connection.

The feeder beam, which essentially extends the clamping point in a straight line, has reinforcements in the area of the clamping point. The reaction forces of the feeder beam with the transfer tools arranged on it are thus transferred to the linear feeder without local stress concentrations.

In the embodiment with a transverse feeder beam and at least one trunk, an upper light metal clamping plate should be provided at least in the clamping area for fastening to the linear feeder, in conjunction with internal reinforcements of the trunk.

For practical purposes, internal reinforcements are also provided in each node.

In order to be able to transfer the forces from the transfer tools over a large area into the load-bearing rectangular box structure of the feeder beam, the inserts are integrated into the side wall of the rectangular profile of the feeder beam and connected to the side wall and the belts.

Embodiments of the subject matter of the invention are explained with reference to the drawing. They show:

Fig. 1 schematically shows a first embodiment of a transfer device on

a press system, in front view,

Fig. 2 is a plan view of Fig. 1, partly in section,

Fig. 3 is a plan view, partly in section, of another embodiment,

Fig. 4 shows a perspective and isolated detail of the embodiment of Fig.

and 2,

Fig. 5 + 6 a side view and a plan view, partly in section, of a detail of the embodiment of Fig. 3,

Fig. 7 shows in perspective and enlarged one end of a feeder beam as shown in

shown in Figs. 3, 5 and 6,

Fig. 8 is a side view of Fig. 4, and

Fig. 9 is an enlarged schematic perspective view of the cross section of the

feeder bar.

A press system P in Fig. 1 and 2 comprises several press tools 1, 2 and can be a single press or a section of a press line. In order to move workpieces between the press tools in cycles and, if necessary, also into and/or out of the press system P, a transfer device T with two three-axis linear feeders L is provided, which work in pairs synchronously across the press table. The linear feeders L move in the transverse direction on stationary guide devices 6. The linear feeders L can be controlled vertically via vertical guides 7. Longitudinal guides 8 are used for control across the longitudinal direction of the press system. (Three NC axes).

Each linear feeder L has a connection 3 for a clamping point 4 for a feeder beam B. The feeder beam B extends parallel to the transverse direction of the press, is freely cantilevered and fixed to a trunk 5 in the clamping point 4, and forms a T-shaped structure with its trunk 5. On the feeder beam B, which has a length of between at least 3.0 m and 7 m or more, transfer tools W for handling the workpieces are attached to at least one interchangeably attached gripper rail M. The feeder beam B is constructed as a box profile with a rectangular cross-section made of continuous carbon fiber reinforced plastic, as will be explained later, and has a natural frequency greater than 20 Hz with high rigidity and torsional strength. A node is provided between the spring beam B and its trunk 5.

The dashed line in the plan view of Fig. 2 indicates that the feeder beam B is π-shaped here and is fastened with two trunks 5' in two clamping points 4' to devices 3' of the linear feeder L. This π-shape reduces torsions in the trunks and is useful, for example, for a feeder beam B of great length, e.g. 7 m or more.

In the embodiment of Fig. 3, each feeder beam B is oriented linearly as an extension of the clamping point 4 along the press table and the pressing tools 2. This straight feeder beam B is similar in its box profile structure to the feeder beam B in Fig. 1 and 2. The design of the feeder beam in the area of the clamping point 4 and the bending moment-appropriate design of the inner

structure from the clamping point to the free end. Each straight feeder beam B in Fig. 3 has a length of at least 3 m at a natural frequency of 20 Hz and can be up to 7 m or longer. The pair of feeder beams is moved synchronously and mainly in the longitudinal direction.

Fig. 4 shows in perspective the feeder beam B of Fig. 1 and 2 with the T-shape and the trunk 5. The dashed line at 5" indicates that the trunk 5 can be cranked in the vertical direction, for example for reasons of better accessibility of the pressing tools or the like. The trunk 5 has a box profile (made of continuous carbon fiber reinforced plastic CFRP) that tapers towards the feeder beam B and is connected to the feeder beam B in a node. The node between the feeder beam B and the trunk 5 does not necessarily have to be exactly in the longitudinal center of the feeder beam B, but can also be placed outside the longitudinal center, as shown. Starting from the node, the feeder beam B is designed to accommodate the bending moment towards both free ends.

The feeder beam B (in each embodiment) consists of an upper belt O and a lower belt U of at least essentially the same structure and constant belt width and belt thickness, which are connected to one another via side walls S. At least in the side wall S facing away from the trunk 5, abutments 9 are positioned for the replaceable attachment of the gripper rail G (Fig. 1) for the transfer tools W. For connection to the linear feeder L in the clamping point 4, reinforcing bands 11 and an upper aluminum clamping plate 10 are provided in the trunk end, which is integrated into the trunk 5 by clamping elements 16. Fastening points for connection to the device part 3 of the linear feeder L are not shown in the clamping plate 10.

Fig. 5 and 6 belong to the feeder beam B of Fig. 3, which has upper and lower aluminum clamping plates 12 on the upper and lower chords O, U as well as lateral aluminum plate elements 13 on the outside of the side walls S for connection in the clamping point 4. These plates 12, 13 are clamped together (Fig. 7) by clamping elements 16 and can, if necessary, also be connected to the feeder beam

t ft ft # fc · · · · 9ft ·

t · ·· · · ft ft ft ft ft ·

■ ft ft ft ·· ···*

B glued, e.g. with thermosetting resin. They form an external reinforcement for the clamping area.

Fig. 5 is a view of the feeder beam B onto the side wall S and shows two sections of gripper rails G which are interchangeably attached to the abutments 9.

The lower half of Fig. 6 is a plan view of the feeder beam B of Fig. 5 with the clamping plate 12. The upper half of Fig. 6 shows a horizontal section of a solid continuous carbon fiber reinforced strip D, which is integrated into the flanges O, U at the edge as a stiffening element and is designed with a cross-sectional profile that is appropriate for the bending moment. This means that, for example, the horizontal thickness of the strip D decreases gradually or in stages (at 14) in the direction from the clamping point 4 to the free end of the feeder beam B.

In the feeder beam B in Fig. 1 and 2, the strips D (not shown) are also designed to accommodate the bending moment. Due to the trunk 5, this means that the strips D gradually or gradually decrease in thickness from the node to the free ends of the feeder beam.

Fig. 8 belongs to the feeder beam B of Fig. 1, 2 and 4, the trunk 5 of which has the upper clamping plate 10 and internal reinforcements not shown.

Fig. 9 shows the detailed structure of the feeder beam B, from Fig. 2 or Fig. 3. The belts O ₁ U contain the solid CFRP strips D in the edge areas, the cross-section of which is indicated by 22. The bending moment-correct cross-section with the thickness gradations 14 is indicated by dashed lines. Between the strips D there is a lightweight laminate structure with, for example, a honeycomb structure 23 and top and bottom cover layers 24 made of solid CFRP. The strips D are glued to the laminate structure 23, 24 with thermosetting resin. The belt width is a multiple of the belt thickness. The vertical distance between the belts O, U corresponds approximately to the belt width. The side walls S are formed by fully glued or welded C-profiles 26, which reach under the strips D with their outward-facing C-legs 27. The C-profiles are made using

made of carbon fibers. The adhesive connection areas in the rectangular profile are indicated at 31.

Furthermore, force introduction inserts K for the gripper rail G are integrated into the feeder beam B, e.g. with light metal elements 32. These are firmly connected to the back of the side wall S and the upper and lower chords O, U, e.g. by gluing. The inserts K form the abutments 9 for the respective gripper rail G.

In order to achieve the highest possible stroke rates, the feeder beams B are very light and stiff so that they have a high natural frequency greater than 20 Hz.

Since only a single linear feeder L is required for a feeder beam B and the feeder beam in the press or on the opposite linear feeder does not require any support but cantilevers without support, minimal equipment is required and the transfer device is very flexible, can be quickly converted, high stroke rates can be processed and a low profitability threshold results due to low investment costs.

These advantages are based on the CFRP lightweight construction of the feeder beam B and its clamping on one side only, so that the greatest possible flexibility is achieved with just one linear feeder to drive the feeder beam. Depending on the dimensions of the press tables, which are usually between 3 m and 5 m (3 m, 3.5 m, 4 m, 4.5 m, 5 m) for body suppliers in the automotive industry, the feeder beam B should be at least 3.0 m long, preferably at least 3.5 m, although it can have a length I of even 7 m and more. To prevent disturbing vibrations from occurring even at high stroke rates, the natural frequency of the beam should be greater than 20 Hz. The geometry can be rod-shaped or C- or Π-shaped. The transfer tools W (grippers, tongs, shovels, etc.) are attached to the gripper rails G, which are interchangeably attached to the feeder beam, depending on the application, to the force introduction inserts K.

Claims (13)

1. Transfer device (T) for a large press system with several pressing tools (1, 2) and one linear feeder (L) arranged in front of and one behind a press for moving workpiece transfer tools (W) in relation to the pressing tools in the longitudinal or transverse direction of the press system, characterized in that a pair of essentially horizontal feeder beams (B) designed as a box profile are provided, each of which is made of continuous carbon fiber reinforced plastic (CFRP) with a length greater than 3.0 m and a natural frequency greater than 20 Hz and additionally has integrated force introduction inserts (K) for at least one gripper rail (G) for the transfer tools (W), and that each feeder beam (B) is attached on one side to a clamping point (4) of the linear feeder (L) and cantilevers without support to the free end. 2. Transfer device according to claim 1, characterized in that the feeder beam (B) forms a straight rod-shaped extension of the clamping point (4) of the linear feeder (L) oriented in the longitudinal direction of the press system. 3. Transfer device according to claim 1, characterized in that the feeder beam (B) runs at least approximately perpendicularly and at a distance from the clamping point (4) on the linear feeder (L) in the transverse direction of the press system and is fixed in the clamping point (4) oriented transversely to the transverse direction of the press system via at least one trunk (5, 5', 5") integrated in a T-shape. 4. Transfer device according to claim 3, characterized in that two clamping points (4') are provided on the linear feeder (L) which are located next to one another in the longitudinal direction of the feeder beam and are oriented transversely to the transverse direction, and that the feeder beam (B) has a π-shape with two trunks (5') in plan view and is connected to both clamping points (4'). 5. Transfer device according to claim 3 or 4, characterized in that the feeder beam (B) is higher or lower than the clamping point (4, 4'), and that the trunk (5") is bent in the vertical direction between the clamping point and the feeder beam. 6. Transfer device according to at least one of the preceding claims, characterized in that the feeder beam (B) has parallel upper and lower belts (O, U) which are spaced apart in the vertical direction and which are connected to side walls (S) within a rectangular cross-section, that each belt (O, U) has CFRP strips (D) on the edge, designed to accommodate the bending moment, with longitudinal fibers (F) at least in the corner regions of the rectangular cross-section and a sandwich profile (23, 24) in between, preferably with a honeycomb structure (23), that the belts (O, U) have flat CFRP layers (24) on the top and bottom, which extend over the CFRP strips (D), cover the honeycomb structure (23), and that the side walls (S) are formed by C-profiles (26) made of CFRP. 7. Transfer device according to claim 6, characterized in that, with a substantially constant belt width, the horizontally viewed thickness of the CFRP strips (D) decreases gradually or stepwise (14) from the clamping point (4) or a node between the feeder beam (B) and the respective trunk (5) in the direction of the respective free end of the feeder beam (B). 8. Transfer device according to claim 6, characterized in that the belts (O, U) and the side walls (S) are prefabricated individual parts and are connected to one another via thermosetting adhesive areas (31) and/or the inserts (K). 9. Transfer device according to claim 2, characterized in that the feeder beam (B) is reinforced in the clamping point connection area by externally arranged light metal clamping plates (13, 12, 15). 10. Transfer device according to claim 3 or 4, characterized in that the trunk (5, 5', 5") is a closed CFRP box profile which has an upper light metal clamping plate (10) and internal reinforcements in the clamping point connection area. 11. Transfer device according to claim 3 or 4, characterized in that the node between the trunk (5) and the feeder beam (B) has inner and/or outer reinforcements. 12. Transfer device according to claim 1, characterized in that the inserts (K) are connected with intermediate distances to the side wall (S) and to the belts (O, U). 13. Transfer device according to claim 12, characterized in that the inserts (K) form abutments (9) for at least one gripper rail (G) for the transfer tools (W).