EP3801940B1 - Facility for producing metal sheets or hollow chamber plates from extruded profiles - Google Patents

Description

The invention relates to a plant for the production of metal sheets from round or approximately round, thin-walled extruded profiles or hollow chamber plates, which are produced in particular from magnesium or magnesium alloys, by means of an extrusion plant. Panel-shaped extruded profiles with inner webs connected to opposite profile walls and at least two mutually adjacent hollow chambers having a common inner web are referred to as hollow chamber plates, which are also referred to as multi-wall or double-wall plates.

It is well known to produce sheet metal by pouring liquid alloy between two rolls, followed by numerous rolling and heat treating processes. Due to the large number of rolling passes from heavy to thin sheet, this process is very cost-intensive. The steps are necessary to achieve a workable wrought structure from a cast structure. The high number of rolling passes is costly.

The DE 43 33 500 C2 discloses a method for producing sheet metal with different wall thicknesses that has a stepped cross-section and a solid profile, in which a semi-finished product is first produced whose cross-section is similar to the cross-section of the sheet metal in the thickness direction, and in which a sheet metal is rolled from the semi-finished product, wherein for the production of the semi-finished product, a hollow profile is extruded with a wall thickness distribution distributed over the circumference and corresponding to the desired wall thickness profile of the semi-finished product, and in doing so Hollow profile is separated along a surface line and formed into the semi-finished product. Furthermore, two complementary profiles are placed one on top of the other, with at least one of the profiled contact sides of the complementary profiles being provided with a separating agent, and the two complementary profiles being rolled out simultaneously with cylindrical, ie non-stepped rolls. Before rolling, the two complementary profiles are separated at two opposing surface lines.

Two parts are made with this method. The manufacturing process is discontinuous and only relatively narrow parts can be manufactured. Another disadvantage is that the production process is relatively expensive due to the production of the semi-finished product with two different wall thicknesses and a stepped roller arrangement.

From the DE 10 2008 048 A1 a method for the production of shaped sheet metal parts and a device for carrying out the method is known. The method comprises the steps of - extrusion or continuous casting of a tubular body, - cutting open the tubular body in its longitudinal direction, - expanding the tubular body into a flat body, - manufacturing the flat body into a component according to the drawing by means of manufacturing technologies known per se. The device essentially consists of a chain of a melting unit, a continuous casting or extrusion unit, a longitudinal cutting device, a roll stand, one or more forming units.

From the DE 10 2007 002 322 A1 discloses a process for the production of sheet metal or sheet metal parts made of light metal, preferably magnesium, in which an extruded profile is produced in an open structure or a closed structure with subsequent slitting to form an open structure in one or more preceding process steps and this is then processed in one or is subjected to several steps of straightening rolling and straightening bending over several rolling and bending stages.

The GB 2469 549A describes a method for producing a support structure, preferably a support structure for a vehicle seat with at least one seat shell for the seat part and/or the backrest of the vehicle seat, with the process steps of producing a metallic semi-finished product and forming it into an essentially flat sheet metal, separating a sheet metal part from the sheet metal and deforming the sheet metal part, the production of the metallic semi-finished product being carried out by extrusion.

The U.S. 2,681,764A describes an apparatus for extruding wide sheet metal comprising a die element having a base portion in the form of an elongated U-shaped slot for producing a U-shaped profile which is subsequently flattened.

The U.S. 1,133,903A describes the conversion of metal tubes into flat strips by cutting the tubes lengthways and expanding them using a double fly share and subsequent rolling.

The U.S. 3,002,255A describes a process for the production of continuous metal strips and the like. Manufacture is accomplished by sequentially extruding a plurality of billets in a shape other than flat, progressively flattening following extrusion and maintaining the shape under tension during the flattening step, and winding up the previously flattened strips during each extrusion step.

The GB 556 061 A describes an improvement in the production of iron and steel sheet from tubes which are continuously cast. After leaving the die of the extrusion press, they are cut lengthwise and expanded and smoothed using shaping rollers.

The US 5,829,298A describes a method and apparatus for the continuous manufacture of metal strip, wherein a workpiece is subjected to a die for forming a tube of circular cross-section and a die formed therein Slit is fed and the tube is opened and flattened by bending outwards in opposite directions in the slit area.

The EP 2 996 825 B1 describes a method and a plant for the production of metal sheets from extruded profiles of small thickness, in particular made of magnesium or magnesium alloys, with the extruded profile emerging from the extrusion die being formed into a metal plate. The system consists of an extrusion press with a die that produces the extruded profile and a forming unit connected to the die. The forming unit consists of a cutting unit for cutting the extruded profile according to the length of the sheet metal to be produced, a bending unit for bending the profile into a U-shape, and a rolling unit for rolling up the U-shaped profile into a metal sheet.

The WO2014/187442 A1 , which forms the basis for the preamble of claim 1, describes a method and a plant for the production of metal sheets from extruded profiles of small thickness, which are produced in particular from magnesium or magnesium alloys, by means of an extrusion plant. The open or closed extruded profile emerging from the extrusion die of an extruder is formed into a flat sheet and then subjected to a defined deformation by stretching. The system for carrying out the process essentially consists of an extrusion press with a die producing the extruded profile and a shaping unit connected to the die, the shaping unit being formed from a separating unit, a bending unit and a winding unit.

The DE 10 2015 118 099 A1 relates to a method for producing a motor vehicle component from a light metal alloy, which comprises the steps of - extruding a profile with at least two different wall thicknesses in cross section, - rolling the extruded profile in sections, - cutting the extruded and rolled section to length into a semi-finished product and - forming, in particular Press forming of the semi-finished product into a motor vehicle component.

The WO2016/012009 A1 relates to a process for the production of a motor vehicle component from extruded aluminum profile by the process steps - extruding a light metal into a profile with an uneven profile cross-section, - cutting the profile to length into profile pieces, - widening the profile pieces, - forming the flattened profile piece into a three-dimensional sheet metal component with areas of different profile thickness (Wall thickness).

The DE 10 2014 008 646 B3 describes a method for the production of closed ring-shaped structural components made of light metal, as well as an arrangement for carrying out the method, in which the profile emerging from the extruder is formed into a helical shape by means of one or more guide tools.

The EP 1 063 443 A1 relates to a method for producing a brake lining, in which a specific amount of friction material is metered onto a carrier plate and pressed under time and temperature control with a predetermined pressure.

The DE 18 04 666 A1 relates to a device for extracting and straightening a strand for arc-shaped continuous metal casting plants. The invention relates to metallurgy.

The object of the invention is to specify a plant for the production of metal sheets from round or approximately round, thin-walled extruded profiles or hollow chamber plates, in particular made of magnesium or magnesium alloys, the preferably open extruded profile emerging from an extrusion tool being expanded to form a metal sheet or a hollow chamber plate and the expansion process is decoupled from the extrusion process.

According to the invention, this object is achieved by the specified embodiment of the characterizing features mentioned in claim 1. Advantageous refinements of the invention are given in the dependent claims.

The open extruded profile emerging from the extrusion tool of an extrusion press is cut according to the length of the metal sheet or twin-wall sheet to be produced, the longitudinal gap of the open extruded profile is widened, preferably to an approximately U-shaped profile, and then transferred to an expanding unit, in which it is formed into a flat Sheet or plate is expanded and then placed in a stacking unit. The system has two expansion units that are arranged parallel to the direction of extrusion. Sheet metal panels with a thickness of <5.0 mm, preferably with a thickness in the range of <2.5 mm, in particular from 1.0 to 1.5 mm, or hollow chamber panels are produced.

In a first step, the extruded profile emerging from the die is separated according to the length of the metal sheet to be produced, and in a second step the longitudinal gap of the open extruded profile is widened, preferably to an approximately U-shaped profile. In the subsequent third step, the U-shaped profile is placed in an expanding unit and gripped by clamping devices on the longitudinal sides of the U-shaped profile and deformed by means of the outwardly moving clamping devices to form a metal sheet or a hollow chamber plate.

Alternatively, the open extruded profile can be deformed into a sheet metal panel or hollow chamber plate by at least one pair of rollers that is moved into the open extruded profile and by moving the individual rollers in the direction of the longitudinal edge areas.

A further possibility of designing the expansion unit is that it is formed from a combination of gripping elements and two movable rollers that can be moved into the U-shaped profile. To protect the surface of the sheet metal to be produced, the rolls can be provided with a heat-resistant, elastic surface coating. The rollers that are used here are designed in such a way that they do not cause any surface damage.

One way to widen an open extruded profile to form a metal sheet or a flat twin-wall sheet is to open the Forming an extruded profile into sheet metal or a twin-wall sheet using a 3-roller unit.

The 3-roller unit of the expanding unit consists of two upper rollers arranged parallel to one another and one lower roller that can be adjusted in the longitudinal direction of the upper rollers. A feed unit, preferably consisting of a pair of rollers, is provided for transporting the profile through the 3-roller unit.

Another way of expanding the open extruded profile is to insert the profile into the expanding unit with its opening pointing upwards and then to retract the 3-roller unit, with the upper rollers inside the profile and the lower roller outside the profile . By moving the 3-roller unit to the left and right, the profile is expanded into a metal sheet or a twin-wall sheet.

The deformation into the metal sheet or hollow chamber plate preferably takes place in a temperature range above 200° C. and in a dry, preferably an inert, atmosphere.

The plant for the production of sheet metal from an extruded profile essentially consists of a furnace for heating the extruded billet to extrusion temperature, an extrusion press with a die for extruding a hollow profile that is open in the longitudinal direction, a cutting device for cutting the extruded profile to length, and a bending unit. Expanding units and a subsequent stacking unit are provided parallel to this bending unit.

To calibrate the expanded metal sheets or twin-wall sheets, a calibration and embossing unit can be provided between the expanding unit and the stacking unit, in which the metal sheet is hot-embossed between two heated embossing plates, i.e. flattened. The calibrating and embossing unit can be in the form of a simple hydraulic press.

The metal sheets are preferably deposited in the stacking unit by a robot which, with its suction cups, picks up the metal sheets or twin-wall sheets from either the expanding unit or the calibrating and embossing unit and places them in the stacking unit.

Cutting or non-cutting devices can be used as separating devices for cutting the extruded profile to length according to the length of the metal sheet. Saws, for example, can be used as cutting separating devices, while rotating jet nozzles, laser cutting devices or wedge or bite cutting are used as non-cutting separating devices.

Advantageous developments and refinements of the invention can be seen from the remaining subclaims and from the exemplary embodiment described in principle below.

Fig. 1

- prinzigmäßiger Aufbau der Anlage

Fig. 2

- Ausschnitt aus der Anlage

Fig. 3 a - b

- Ablängen des Hohlprofils

Fig. 4

- Schnitt A-A

Fig. 5, 5 a-c

- Aufweitvorgang des u-förmigen Profils

Fig. 6

- u-förmiges Mehrkammerprofil

Fig. 7

- Kalibrier- und Prägeeinheit

Fig. 8

- Ausführungsform einer Aufweiteinheit

Fig. 9

- Ablauf des Herstellungsprozesses

The invention will be described in more detail using an exemplary embodiment. Show it

1

- Principial structure of the system

2

- Excerpt from the plant

Fig. 3 a - b

- Cutting the hollow profile to length

4

- Section AA

Fig. 5, 5ac

- U-shaped profile expansion process

6

- U-shaped multi-chamber profile

7

- Calibration and embossing unit

8

- Embodiment of an expansion unit

9

- Flow of the manufacturing process

The figure 1 shows the basic structure of the plant for the production of metal sheets from extruded profiles. The system essentially consists of an extrusion press 1 for the production of an extruded profile 7 with an upstream furnace 2 for heating the extruded billet 8 to the extrusion temperature, a bending unit 4 , which is arranged downstream of the extruder 1 in the direction of extrusion, a cutting device 6 for cutting the extruded profile 7 to length - in the following as Hollow profile 7 denotes -, and two expansion unit 3 arranged parallel to the extrusion direction with subsequent stacking unit 5 .

All the facilities of the system are interlinked, with the transfer of the U-shaped profile 7 to the expansion unit 3 and the expanded profile 7 to the stacking unit 5 and, if necessary, to the intermediate calibration and embossing unit by handling devices, preferably by industrial robots. For this purpose, the handling devices are equipped with mechanical or pneumatic gripping systems.

The figure 2 shows a section of the plant for the production of metal sheets from extruded profiles 7. The extruded billet 8 heated in the furnace 2 to an extrusion temperature of between 200 and 520°C, preferably to 470°C, is inserted into the recipient 10 of the extruder 1 and pressurized through the die 9 is pressed out to form an open profile 7 , ie the profile 7 is slotted in the longitudinal direction. The figure 4 shows a section AA through the pressed profile 7.

After a predetermined length of the profile 7 has been pressed out, the extrusion press is stopped and the profile 7 is cut to length by the cutting device 6 according to the length of the sheet metal plate to be produced. The Figure 3a shows a variant of the separating device 6 for cutting the open profile 7 to length. The hollow profile 7 is cut to length from the extruded strand by a wedge cutting device 14 in which one or more wedge cutting wheels 14 circumferentially separate the profile 7 from the strand. The wedge cutting wheel or wheels separate the material that lies on a base and is pushed apart by moving the wedge-shaped cutting edges. The base is formed by extending the piercing mandrel 12 .

Another variant of cutting the hollow profile 7 to length from the strand is in Figure 3b shown. On the outside of the profile 7 is an annular counter bearing. The wedge cutting device 14 is moved into the interior. At the end, there are two opposite, hydraulically movable wedge cutting wheels, which cut the material while rotating at the same time. The pressurization and the rotation of the wedge cutting device 14 is carried out by the drive and hydraulic device 15.

Wedge or bite cutting has the advantage that, as a non-cutting cutting process, it does not form any chips or splinters, which would otherwise have to be laboriously removed from the surface in the cutting area.

After the profile 7 has been cut to length, it is released in the extrusion device, ie the profile 7 slit in the longitudinal direction and placed on the angle rails 11 of the bending unit 4 is moved out of the area of the separating device 6 . The profile 7 is then bent up into a U-shape ( figure 5 ) by moving the angle rails 11 apart.

The profile 7 bent up in a U-shape is grasped by means of a handling device (not shown in detail) and brought into the expansion unit 3 . Here the U-shaped profile 7 is completely widened. For this purpose, the profile 7 is inserted with its longitudinal sides into the rotatably mounted clamping units 16 , the profile 7 being deformed into a flat sheet by moving the clamping units 16 apart. The Figures 5a to 5c show the individual sections of the widening of the profile 7 to form a flat sheet metal panel 19.

The profile 7 bent up in a U-shape and inserted into the clamping units 14 of the expansion unit 3 is clamped in the clamping unit 16 by the clamping rail 18 . The clamping takes place by applying pressure to the clamping rail 18. For this purpose, at least two hydraulic cylinders 17 are arranged along the outer side of the clamping rails over their length.

By opening the clamping units 16, the U-shaped profile 7 becomes a flat sheet metal panel 19 ( Figure 5 c) flared. The sheet metal panel 19 is then grasped by a handling device, preferably by means of suction grippers, and placed in the stacking unit 5 .

If the metal sheets 19 still have bumps after the expansion process, they are before they are stored in the stacking unit 5 to a calibration or hand over embossing unit. For this purpose, the metal plate 19 is clamped on the transverse side and moved into the calibrating and embossing station by means of a linear drive. In the calibrating and embossing unit, the metal sheet 19 is hot embossed, which eliminates any unevenness that may be present.

The calibrating and embossing unit is formed by two heated embossing plates 24 that can be moved relative to one another, it being possible for the embossing plates 24 to be opened and closed by a simple hydraulic press.

After the calibration and embossing process, the metal sheet is picked up by a handling device with a suction gripper and placed in the stacking unit 5 .

In a further exemplary embodiment, the production of twin-wall sheets 20 is described. The figure 6 shows the extruded profile 7 produced by means of the extruder 1 , which forms the basis for a hollow comb plate 20 .

The extruded profile 7 is designed in such a way that it assumes the shape of a flat hollow chamber plate 20 after it has been expanded. The underside 22 of the hollow comb plate 20 is the extruded profile 7 designed such that the sections of the underside 22 and top 21 between the inner webs 23 have the same length, whereby the sections of the underside 22 between the inner webs 23 are arcuate. After the expansion process, the sections between the inner webs 23 on the bottom 22 and the top 21 then have the same length.

The extruded profile 7 emerging from the die of the extruder 1 in a first step is separated according to the hollow chamber panel 20 to be produced. As a separating device 6 is preferably a metal-cutting separating device, z. B. a saw, for use. This is connected to a suction device for the chips.

Subsequently, the extruded profile 7 is bent up into a U-shaped profile 7 by means of the bending unit 4 and then brought into an expanding unit 3 . Bending up into a U-shaped profile 7 takes place by moving apart the angle rails 11 of the bending-up unit 4.

In the expansion unit 3, the U-shaped profile 7 is expanded to form a flat hollow chamber plate 20 . After the expansion process, the twin-wall sheet 20 is placed in a calibrating and embossing unit.

The calibration and embossing unit is shown schematically in figure 7 shown. It consists essentially of two mutually movable heated embossing plates 24 between which the hollow chamber plate 20 is arranged during the calibration and embossing process. As a result, the hollow comb plates 20 are brought to a uniform dimension with regard to the distance between the top and bottom sides 21 , 22 and are also straightened at the same time.

The figure 8 shows a further embodiment of the expansion unit. This essentially consists of a 3-roller unit 25 , the two upper rollers 26 and a lower roller 27 that can be moved in the direction of the upper rollers 26 -Unit 25 and is transported by this.

After the longitudinal side (front edge) of the profile 7 has been gripped by the pair of rollers 28 , it is pushed in the direction of the 3-roller unit. When the front edge of the profile 7 reaches the second upper roller 26 , the lower roller 27 is moved in the direction of the upper rollers 26 . With the further pushing of the profile 7 through the 3-roller unit 25 , it is formed into a flat metal plate 19 , ie it is widened from the U-shaped profile 7 to the metal plate 19 . This can be followed by a calibration or embossing step, or the metal sheet 19 can be placed in the stacking unit 5 right away.

In the figure 9 the flow of the manufacturing process is shown in simplified form. Starting from the extruded billet 8, a tubular, open extruded profile 7 is produced by means of an extruder 1 and correspondingly by means of a separating device 6 the length of the metal sheet 19 or the hollow panel 20 separated from the strand. The extruded profile 7 is then bent up in a U-shape. After being transferred to an expanding unit 3 , the extruded profile 7 is expanded to form a sheet metal panel 19 or a hollow comb plate 20 .

All parts of the system that come into contact with the U-shaped profile 7 or the sheet metal plate 19 or the hollow comb plate 20 are provided with a coating, preferably with a ceramic material, or made of a magnesium-compatible material in order to avoid direct contact with to prevent a ferrous material.

The system according to the invention for the production of metal sheets or hollow chamber plates from extruded profiles has the advantage that the expansion process to form a flat metal sheet or a hollow chamber plate is decoupled from the extrusion process, which means that the number of cycles for production can be significantly increased.

The extrusion of magnesium sheets also has the advantage of being able to produce very small sheet thicknesses in a single process step and thus represents an alternative to rolling or cast-rolling.

Not only can sheet metal thicknesses be very small, but also very wide sheets can be produced by extruding hollow profiles, for example pipes. Very wide twin-wall sheets can also be produced using the extrusion process. The width results from the circumference of the extruded profiles according to the formula u = d * n. For example, with a tube diameter of 300 mm, a sheet with a width of approx. 942 mm can be produced.

List of reference numbers:

1 -

extruder

2 -

Oven

3 -

expansion unit

4 -

bending unit

5 -

stacking unit

6 -

separator

7 -

Extruded profile / profile

8th -

extrusion billet

9 -

die

10 -

recipient

11 -

angle rail

12 -

piercer

13 -

counter bearing

14 -

wedge cutting device

15 -

Drive and hydraulic unit

16 -

clamping unit

17 -

hydraulic cylinder

18 -

clamping rail

19 -

sheet metal

20 -

twin wall panel

21 -

top

22 -

bottom

23 -

inner bar

24 -

embossing plates

25 -

3 reel unit

26 -

top roller

27 -

bottom roller

28 -

pair of rollers

Claims (5)

1. Production line for the production of metal sheets (19) from round or approximately round thin-walled extruded profiles or hollow chamber plates (20) made from extruded profiles, all of which are made of light metals, preferably magnesium or magnesium alloys, comprising an extrusion press (1) for producing an extruded profile (7) open along its surface line, a separating device (6) for cutting the extruded profile (7) to length according to the length of the metal sheet (19) or hollow chamber plate (20), a bending unit (4) for widening the longitudinal gap of the open extruded profile (7), an expanding unit (3) for expanding the open extruded profile (7) into a flat sheet (18) or hollow chamber plate (20), and a stacking unit (5),
   characterized in that
   two expanding units (3) are arranged in parallel to the extrusion line and connected to the same extrusion press (1), the extrusion press (1) and the expanding units (3) being connected to one another by means of a handling device for transferring the U-shaped profile (7) to the expanding units (3) to keep the extrusion and expanding processes independent from one another.
2. Production line according to claim 1,
   characterized in that
   the expanding unit (3) is formed by two movable and rotatable clamping devices (16), the latter consisting of a U-shaped rail and a clamping rail (18) arranged therein and acted upon by at least two hydraulic cylinders (17).
3. Production line according to claim 1,
   characterized in that
   the expanding unit (3) is formed by a 3-roller unit (25), wherein the 3-roller unit (25) consists of two upper rollers (26) arranged parallel to one another and a lower roller (27) movable in the direction of the upper rollers (26), and a feed or transport unit being associated with the 3-roller unit.
4. Production line according to claims 1 to 3,
   characterized in that
   all parts of the line coming into contact with the hollow chamber profile, the open extruded profile (7) or the metal sheet (19) are fitted with a coating or consist of a magnesium-compatible material to prevent direct contact with a ferrous material.
5. Production line according to claims 1 to 4,
   characterized in that
   all components of the line are interlinked, the transfer of the U-shaped hollow profile (7) to the expanding unit (3) as well as the transfer of the expanded flat metal sheet (19) to the stacking unit (5) and, if necessary, to the interposed calibrating and embossing device, being effected by means of handling devices equipped with mechanical or pneumatic gripping systems.

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