EP4041470B1 - Device for stretching a metal semi-finished product in the form of individual plates along a stretching section with a stretching frame, and method for stretching a metal semi-finished product using the device - Google Patents

Description

The invention relates to a device for stretching a metal semi-finished product in the form of individual plates along a stretching section with a stretching frame, comprising pressure columns extending in the axial direction of the stretching section, a first clamping head in which a first narrow side of the semi-finished product to be stretched can be clamped and by means of stretching cylinders is axially displaceable, and a second clamping head, in which the second narrow side of the semi-finished product to be stretched can be clamped.

The invention further relates to a method for stretching a metal semi-finished product in the form of individual plates along a stretching section using the device described above.

Plate stretchers and plate stretching methods of the type described above are known in the prior art, for example from the publications DE 10 2016 105 306 A1 and DE 10 2015 214 207 A1 or FR 1 538 250 A .

Such plate stretchers generally have two clamping heads directed towards one another, which can be displaced relative to one another in order to apply a clamping force directed along a stretching direction. They are used for stretching and/or straightening rolled or pressed material, in particular for stretching and/or straightening individual sheets or plates that are clamped or wedged in the clamping heads. Depending on the design of the panel connector, both clamping heads can be moved during stretching. However, arrangements are often found in which a fixed clamping head and a opposite one movable clamping head are provided. Such an arrangement is, for example, from DE 10 2015 14 207 A1 known, in which the movable clamping head can be moved via hydraulic stretching cylinders and stretching rods, whereas the fixed clamping head comprises a carriage which can be locked relative to pressure column elements of the stretching frame. Locking in different positions is desirable because when stretching individual plates or sheets, unlike the quasi-continuous straightening of sheets wound into coils, different workpiece lengths or plate lengths or sheet lengths are worked and the stretching frame must be adjustable accordingly. Methods and devices for straightening metal sheets that are wound into coils are, for example, from EP 1 923 150 B1 and the US 2002/0104360 A1 known.

Known plate stretchers are loaded and unloaded with plates from above using a crane system. The clamping heads must first be set to a dimension larger than the plate to be stretched. The clamping heads then move together and feed the plate to the clamping devices integrated into the clamping heads. For unloading, the clamps are opened after the stretching process and the clamping heads are moved back to a size larger than the stretched plate. This procedure has the disadvantage that a relatively large stroke of the stretching cylinder is required since the clamping heads have to be set to a dimension that is greater than the length of the plate to be stretched. In addition, the non-productive times of the stretching process are high compared to the time required for stretching. Overall, the required cycle time is relatively long.

A method and a device for leveling rectangular sheets is, for example, from EP 2 446 979 A1 known.

A stretching device for sheet metal with three clamping heads is from the US 2011/0296898 A1 known. The stretching device described there comprises a fixed clamping head and two movable clamping heads, which can be moved relative to one another and together with respect to the fixed clamping head. The fixed clamping head includes a first window through which the pulling metal sheets can be passed through and in which the metal sheet can be fixed, whereas the second clamping head comprises a second window through which the metal sheet can be passed and in which the metal sheet can be clamped. The stretching device further comprises a receiving structure to which an actuator for the movable clamping head is attached. The receiving structure is passed through the window of the movable clamping head to ensure that the loads on the receiving structure are minimized. The ones in the US 2011/0296898 A1 The stretching device described includes a receiving structure or a frame that is designed to absorb low stretching forces.

The invention is based on the object of providing a plate stretcher of the type mentioned at the beginning and a corresponding method in which the non-productive times are reduced and the overall cycle time is therefore optimized.

The task is solved by a device with the features of claim 1. The object on which the invention is based is further achieved by a method with the features of claim 8. Advantageous embodiments of the invention result from the subclaims.

According to one aspect of the invention, a device is provided for stretching a metal semi-finished product in the form of individual plates along a stretching section with a stretching frame. The device comprises pressure columns extending in the axial direction of the stretching section, a first clamping head in which a first narrow side of the semi-finished product to be stretched can be clamped and which can be axially displaced by means of stretching cylinders, and a second clamping head in which the second narrow side of the semi-finished product to be stretched can be clamped is. The device according to the invention or the plate stretcher according to the invention is characterized in particular by the fact that at least one axial feed and one axial outlet of the stretching frame are provided and that the clamping heads are designed in such a way that the semi-finished product to be stretched is axially passed through at least one of the clamping heads , can preferably be carried out by both clamping heads. The plates can therefore be fed in and removed in the direction of the force applied during stretching.

This eliminates the need for loading and unloading the device from above using a crane. The feeding and removal of the individual plates can be fully automated. The cycle time required to stretch a single panel is drastically reduced. In addition, the length of the stretching cylinders is reduced, whereby the plate stretcher according to the invention can have smaller overall dimensions.

Preferably, at least one clamping head has at least one clamping head mouth which is open in the stretching direction, so that the plate to be stretched can be inserted from the outside in the axial direction into the relevant clamping head mouth. The clamping head mouths are preferably facing away from one another in the stretching frame in the axial direction of the stretching section and at least one clamping head is designed such that a plate can be passed through the clamping head in question, so that the plate can be positioned between the clamping heads.

In the plate stretcher according to the invention, it can be provided that both clamping heads can be moved while a plate is being stretched. It is preferably provided that the second or the first clamping head is locked or lockable relative to pressure column elements of the stretching frame. For this purpose, the stretching frame can have a locking device which, for example, corresponds to the one in the DE 10 2015 214 207 A1 is described.

The clamping heads can have means for clamping and/or wedging the workpiece or plate in a known manner.

The axial feed expediently comprises a feed roller table and the axial outlet includes an outlet roller table. The feed roller table and/or the outlet roller table can comprise driven rollers, so that the feeding of the plate and the exit of the plate can be accomplished in the axial direction of the stretching section.

Preferably, the feed roller table and/or the outlet roller table are height-adjustable in order to be able to position the plate at the average height level of the plate connector or the route level during loading or unloading. The panels to be stretched are usually provided on roller conveyors above the floor. The feed roller table can take over the plate to be stretched at the height level at which it is provided. The feed roller table is then brought up to the relevant clamping head and adjusted to the appropriate height level. The stretched plate is transported away in a similar manner using the exit roller table.

Preferably, a first and a second loading device are provided, the first loading device being arranged on the first clamping head and the second loading device being arranged on the second clamping head, the loading devices each comprising driven rollers. The loading devices enable the height of the plate to be stretched to be positioned, the plate to be centered in the longitudinal axis and the plate to be driven.

The plate is preferably conveyed from below by means of driven rollers and with pressure rollers acting from above. The loading devices can each have a centering unit. These can, for example, according to the DE 10 2016 105 306 A1 be carried out in the manner described.

In an advantageous variant of the device according to the invention it is provided that at least one transverse straightening press is provided between the first and the second clamping head. The transverse straightening press can be designed so that it applies a force acting perpendicular to the clamping force or stretching force to the plate. This allows the plate in question to be aligned transversely during stretching, so that the plate is prevented from buckling during stretching. Preferably, several mobile transverse straightening presses are provided, which can be moved along in the stretching direction of the plate during stretching.

Alternatively or additionally, a centering device can be provided on at least one transverse straightening press, which takes over the centering of the plate when it is fed to the second clamping head.

• Zuführen einer einzelnen Platte mit ihrer ersten Schmalseite in axialer Richtung der Reckstrecke an den ersten Spannkopf,
• Durchführen der Platte durch den ersten Spannkopf und Zuführen der Platte mit der ersten Schmalseite an den zweiten Spannkopf in axialer Richtung der Reckstrecke,
• Festlegen der Platte in dem ersten und dem zweiten Spannkopf,
• Strecken der Platte mit einem vorgegebenen Hub auf eine vorgegebene Länge und
• Fördern der gestreckten Platte in axialer Richtung der Reckstrecke durch den zweiten Spannkopf hindurch.

The object on which the invention is based is further achieved by a method for stretching a metal semi-finished product in the form of individual plates along a stretching section using the plate stretcher described above according to the invention. The process is characterized by the following process steps:

• Feeding a single plate with its first narrow side in the axial direction of the stretching section to the first clamping head,
• Passing the plate through the first clamping head and feeding the plate with the first narrow side to the second clamping head in the axial direction of the stretching section,
• Fixing the plate in the first and second clamping heads,
• Stretching the plate with a predetermined stroke to a predetermined length and
• Conveying the stretched plate in the axial direction of the stretching section through the second clamping head.

Passing the plate through the first clamping head and feeding the plate to the second clamping head as well as conveying the stretched plate through the second clamping head can be done by means of the first and second loading devices.

The plate is expediently directed transversely during stretching by means of at least one transverse straightening press, i.e. H. transverse to the axial extent or transverse to the stretching force acting in the axial direction. At least one transverse straightening press can be moved along in the stretching direction of the plate during stretching.

Before being fixed in the clamping heads by means of the first and/or the second loading device, the plate is preferably automatically positioned in a predetermined position within the stretching frame by means of at least one position measuring system. For example, light barriers can be installed in the clamping heads to detect the position of the plate. With the position information obtained in this way, the drive of the loading device can position the plate precisely within the stretching frame.

The invention is explained below with reference to the accompanying drawings using an exemplary embodiment.

Figur 1

eine Seitenansicht des Plattensteckers gemäß der Erfindung und

Figur 2

eine Draufsicht auf den Plattenstrecker gemäß Figur 1

Show it:

Figure 1

a side view of the panel connector according to the invention and

Figure 2

a top view of the plate stretcher according to Figure 1

The plate stretcher 1 according to the invention comprises a stretching frame 2 with a first and a second clamping head 3, 4 which can be moved within the stretching frame 2. The stretching frame 2 comprises a first and a second stretching cylinder 5, 6, the first stretching cylinder being located on a first pressure column 7 and the second stretching cylinder 6 is supported on a second pressure column 8. The first and second pressure columns 7, 8 each form the abutment for first and second stretching rods 9, 10 of the first and second stretching cylinders 5, 6. The first and second stretching rods 9, 10 are each aligned with the first and second pressure columns 7, 8 arranged and form the stretching frame 2. The first clamping head can be moved along the stretching rods 9, 10 with the help of the stretching cylinders 5, 6. With a hydraulic drive, the stretching cylinders 5, 6 are subjected to a pressure medium, which causes movement of the first clamping head 3 in the axial direction of the stretching section formed by the stretching frame 2 relative to the second clamping head 4. In the exemplary embodiment described, the second clamping head 4 is locked relative to the pressure columns 7, 8, i.e. fixed, whereas the first clamping head 3 is movable relative to the second clamping head 4.

The clamping heads 3, 4 each have a clamping head mouth 11. The clamping head mouths face away from one another within the stretching frame 2. The clamping head mouth 11 of the first clamping head 3 is opened in the direction of a feed roller table 12, the clamping head mouth 11 of the second clamping head 4 is opened in the direction of an outlet roller table 13. The clamping heads 3, 4 each include clamping jaws 16, which wedge the plate in the stretching direction and which can be opened to pass the plate or the semi-finished product through. Both the feed roller table 12 and the outlet roller table 13 include driven rollers.

The first clamping head 3 is assigned a first loading device 14, which is arranged on the side facing the clamping head mouth 11, whereas the second clamping head 4 is assigned a second loading device 15, which is arranged on the side facing away from the clamping head mouth 11. The loading device 14, 15 include driven rollers and effect positioning and centering of the plate within the stretching frame 2.

A plate, not shown, is fed from the right to the stretching frame 2 via the feed roller table 12 in the drawings. This plate is then taken over by the first loading device 14 and guided through the clamping head mouth 11 of the first clamping head 3 in a correspondingly centered manner. A first narrow side of the plate (narrow side leading in the conveying direction) is fed to the second clamping head 4 and inserted and fixed in it. The second narrow side of the plate (narrow side lagging in the conveying direction) is or is fixed in the first clamping head 3. The first clamping head 3 is then moved relative to the second clamping head 4, the plate being stretched between the first and the second clamping heads 3, 4. After the stretching process has ended, the clamping or wedging of the plate is released and the plate is moved further through the second Clamping head 4 is conveyed through to the outlet roller table 13. Immediately afterwards, another plate can be loaded via the feed roller table 12.

Reference character list

1

Plate stretcher

2

Stretching rack

3

first clamping head

4

second clamping head

5

first stretching cylinder

6

second stretching cylinder

7

first pressure column

8th

second pressure column

9

first horizontal bar

10

second horizontal bar

11

clamping head mouth

12

Feed roller table

13

Outfeed roller table

14

first loading device

15

second loading device

16

Jaws

Claims (12)

1. Device for stretching a metal semi-finished product in the form of individual plates along a stretching path with a stretching frame (2), comprising pressure columns (7, 8) extending in axial direction of the stretching path, a first and a second clamping head (3, 4) movable within the stretching frame (2), wherein the first clamping head (3) in which a first narrow side of the semi-finished product to be stretched can be clamped [and which] is axially displaceable by means of stretching cylinders (5, 6), and in the second clamping head (4) a second narrow side of the semi-finished product to be stretched can be clamped, characterised in that the stretching frame (2) comprises a first and a second stretching cylinder (5, 6), wherein the first stretching cylinder is supported on the first pressure column (7) and the second stretching cylinder (6) on the second pressure column (8), wherein the first and the second pressure columns (7, 8) respectively form the counter-bearing for first and second stretching rods (9, 10) of the first and second stretching cylinders (5, 6) and are respectively arranged in alignment with the first second pressure columns (7, 8) as well as form the stretching frame (2), and that at least one axial feed and axial outlet of the stretching frame (2) are provided and that the clamping heads (3, 4) are so constructed that the semi-finished product to be stretched can axially pass through at least one, preferably through both, of the clamping heads (3, 4).
2. Device according to claim 1, characterised in that the axial feed comprises a feed roller path (12) and the axial outlet an outlet roller path (13).
3. Device according to claim 2, characterised in that the feed roller path (12) and/or the outlet roller path (13) comprises or comprise driven rollers.
4. Device according to one of claims 2 and 3, characterised in that the feed roller path (12) and/or the outlet roller path (13) is or are adjustable in height.
5. Device according to any one of claims 1 to 4, characterised by a first and a second loading device (14, 15), wherein the first loading device (14) is associated with the first clamping head (13) and the second loading device (15) is associated with the second clamping head (4), wherein the loading devices (14, 15) preferably each comprise driven rollers.
6. Device according to claim 5, characterised in that the loading devices (14, 15) each comprise at least one centring unit.
7. Device according to any one of claims 1 to 6, characterised in that at least one preferably movable transverse straightening press is provided between the first and the second clamping heads (3, 4).
8. Method for stretching a metal semi-finished product in the form of individual plates along a stretching path with use of a device according to any one of claims 1 to 7, characterised by the following method steps:

   - feeding an individual plate with its second narrow side in axial direction of the stretching path to the first clamping head,

   - passing the plate through the first clamping head and feeding the second narrow side of the plate to the second clamping head in axial direction of the stretching path,

   - fixing the plate in the first and the second clamping heads,

   - stretching the plate by a predetermined stroke to a predetermined length and

   - conveying the stretched plate in axial direction of the stretching path through the second clamping head.
9. Method according to claim 8, characterised in that the passing of the plate through the first clamping head and the feeding of the plate with the second narrow side to the second clamping head as well as the conveying of the stretched plate through the second clamping head are carried out by means of the first and second loading devices.
10. Method according to claim 9, characterised in that the plate is straightened transversely during the stretching.
11. Method according to any one of claims 8 to 10, characterised in that at least one transverse straightening press co-travels in stretching direction of the plate during the stretching.
12. Method according to any one of claims 8 to 11, characterised in that the plate prior to fixing in the clamping heads is automatically positioned in a predetermined position within the stretching frame by means of the first and/or second loading device by way of at least one position measuring system.

Images