DE102021127807A1 - Process for the area-wise forming of slender workpieces, workpiece and device - Google Patents

Abstract

Method for regionally forming slender workpieces, comprising the steps of:- providing a workpiece which extends along a longitudinal direction;- holding the workpiece at a first clamping point with a first tool;- holding the workpiece at a second clamping point with a second tool, which along the longitudinal direction at a distance from the first clamping point, whereby a forming area is formed between the clamping points;- moving the first tool from a first position to a second position for plastically deforming the forming area, the workpiece being at the first clamping point or the second clamping point can move translationally relative to the respective tool.

Description

The present invention relates to a method for regionally forming slender workpieces, a workpiece and a device.

It is known from the prior art to bend profiles or rails in order to realize desired curves. Depending on the geometry of the starting material and its material, however, this is often relatively complex or is subject to many limiting boundary conditions. The DE 10 2018 217 785 A1 relates, for example, to a method for producing a two-dimensional or three-dimensional flat conductor made of metal. Here, a piece of wire of the appropriate length is provided and bent to create a two-dimensional shape. The bent piece of wire is then pressed flat, with a correspondingly two-dimensionally shaped flat profile being produced from the two-dimensionally shaped piece of wire. In a further step, the flat profile can be bent, with a three-dimensional flat profile being produced from the two-dimensionally shaped flat profile. A die bending tool is used for this. In addition to the disadvantages mentioned above, such an approach is also problematic if the component geometry is to change.

It is therefore an object of the present invention to specify a method for regionally forming slim workpieces, a workpiece and a device for forming, with complex geometries and free-form curves being able to be represented efficiently, process-reliably and quickly.

This object is achieved by a method according to claim 1, by a workpiece according to claim 12 and by a device according to claim 13. Further advantages and features emerge from the subclaims and the description and the attached figures.

• - Bereitstellen eines Werkstücks, welches sich entlang einer Längsrichtung erstreckt;
• - Halten des Werkstücks an einer ersten Einspannstelle mit einem ersten Werkzeug;
• - Halten des Werkstücks an einer zweiten Einspannstelle mit einem zweiten Werkzeug, welches entlang der Längsrichtung um einen Abstand zu der ersten Einspannstelle beabstandet angeordnet ist, wodurch zwischen den Einspannstellen ein Umformbereich gebildet wird;
• - Verlagern des ersten Werkzeugs von einer ersten Position in eine zweite Position zum plastischen Verformen des Umformbereichs, wobei sich das Werkstück an der ersten Einspannstelle oder der zweiten Einspannstelle relativ zum jeweiligen Werkzeug translatorisch bewegen kann.

According to the invention, a method for regionally forming slender workpieces comprises the steps:

• - providing a workpiece which extends along a longitudinal direction;
• - Holding the workpiece at a first clamping point with a first tool;
• - holding the workpiece at a second clamping point with a second tool which is arranged along the longitudinal direction at a distance from the first clamping point, whereby a forming area is formed between the clamping points;
• - Shifting the first tool from a first position to a second position for plastic deformation of the forming area, wherein the workpiece can move translationally at the first clamping point or the second clamping point relative to the respective tool.

The holding is to be understood in particular as a positive and/or non-positive holding. The positive and/or frictional connection is formed via the tools in each case. The holding expediently takes place in such a way that the tool can move translationally relative to the tool at one of the clamping points. This relative movement ensures that thinning of the workpiece is avoided or compensated for. In the forming area, the material can automatically seek the optimal course during plastic deformation. Advantageously, the geometry of the workpiece is not specified in the forming area. Rather, it results automatically from the positions of the clamping points after forming and the material properties of the workpiece. This exploits the fact that the course of the curve when bending is automatically oriented towards the lowest bending resistance.

The translational movement or the extent of the movement is controlled via the geometry and/or the force with which the workpiece is held in the area of the respective clamping point.

It should be noted that certain boundary conditions should also be observed with this method. For example, the curvature during bending must not be too great to ensure that the cross section of the workpiece in the forming area does not taper in an unacceptable manner.

According to a preferred embodiment, the workpiece is a flat material or flat strip. Structures of this type are often used as current conductors in partially or fully electrified motor vehicles.

According to a preferred embodiment, the position of the second tool is not changed. In other words, for example, the second clamping point remains in its original position. The position of the first tool is expediently changed in this case. According to a preferred embodiment, the workpiece can move relative to the first tool at the first clamping point. Alternatively, the method can also be designed in such a way that the workpiece can move relative to the second tool at the second clamping point.

According to a preferred embodiment, shifting from the first position to the second position includes a number of partial movements.

According to a preferred embodiment, the partial movements include at least one of the following: bending, rotating, shifting. There are no restrictions with regard to the position and orientation of the bending or rotation axes. This can be freely positioned. Here, the advantage is used that the forming area can deform freely. Its end geometry is therefore advantageously not "designed", but results from the end position of the clamping points after forming. As already mentioned, material-specific and geometric boundary conditions should be taken into account.

According to a preferred embodiment, the movement of the workpiece relative to the respective tool is a translation in at least one spatial direction. The translation can be specified via the shape of the respective tool. According to one embodiment, the translation is possible along or in particular only along the longitudinal direction. Alternatively, the translation can also be possible in several spatial directions, preferably also simultaneously.

According to one embodiment, the clamping point forms a clamping plane. This applies in particular when a flat strip is used as the workpiece. According to one embodiment, within the plane or a movement/displacement of the workpiece in the respective clamping point is possible.

At this point it should be mentioned that the workpiece or the starting material can also be a profile, such as is produced by means of extrusion, for example.

According to a preferred embodiment, the workpiece is a profile, in particular an extruded profile, which can have the most varied of shapes in cross section. According to a preferred embodiment, the profile has a cross-section that is rectangular in cross-section. The workpiece is preferably a flat material or a flat strip. Preferred materials here are, in particular, metals such as steel, aluminum or copper.

According to a preferred embodiment, the tools for holding or in particular for holding the workpiece in a positive and non-positive manner have holding sections. The shape of the holding sections is advantageously based on the shape of the workpieces. In the case of a flat strip or flat material, tools in the form of clamps are expediently used. These enable the workpiece to be held preferably flat. The holding sections preferably have contact surfaces, which enable the workpiece to be held flat.

• - Verwenden von Werkzeugen, welche unterschiedlich lange Halteabschnitte aufweisen, wodurch unterschiedlich lange Einspannstellen geformt werden können.

According to a preferred embodiment, the method comprises the step:

• - Use of tools which have holding sections of different lengths, whereby clamping points of different lengths can be formed.

Depending on the material thickness or the material properties of the workpiece, it can be advantageous to vary the size of the clamping points or to adjust them accordingly. Large, especially long, clamping points can be effective if the material strength/thickness is relatively high. If more than two tools are to be used at the same time, as will be described later, the use of smaller/shorter tools can be advantageous, etc. However, this is easily possible due to the simple tool shape.

• - Formen des Werkstücks an einer Vielzahl von Umformbereichen.

According to one embodiment, the method comprises the step:

• - Forming of the workpiece at a variety of forming areas.

This means that the workpiece can have a number of forming areas, for example two, three, four, five, etc.

• - Verwenden, insbesondere auch gleichzeitiges oder sequenzielles Verwenden, von mehr als zwei Werkzeugen.

In addition, this also means simultaneous deformation of the workpiece in a large number of deformation areas. According to one embodiment, the method comprises the step:

• - Use, especially simultaneous or sequential use, of more than two tools.

The workpiece can be formed in several places at the same time. Alternatively, several forming areas are processed one after the other in order to realize the final geometry of the workpiece.

• - Ansetzen der Werkzeuge derart, dass unterschiedlich lange Umformbereiche gebildet werden.

According to one embodiment, the method comprises the step:

• - Attaching the tools in such a way that forming areas of different lengths are formed.

The length of the forming areas can be easily adjusted via the size of the distance. For example, it is also easily possible to increase the distance somewhat if the deformation in the forming area involves impermissible geometries would require. The forming areas can expediently be designed with different lengths and as required along the workpiece.

• - Temperieren, insbesondere Erwärmen des Umformbereichs. Damit kann der Widerstand beim Umformen reduziert werden.

According to one embodiment, the method comprises the step:

• - Tempering, in particular heating of the forming area. The resistance during forming can thus be reduced.

The process can be done before or after a coating is applied to the workpiece. In particular, the method can be used before and/or after the application of any insulation that may be required. In order to avoid detachment of the coating/insulation that may have been applied before the bending or forming, the aforementioned heating of the forming area can be particularly helpful.

According to one embodiment, for example, an infrared radiation source is used to heat the forming area.

The invention also relates to a workpiece, in particular a conductor element, which has been manufactured or processed using the method according to the invention. According to a preferred embodiment, the conductive element is a conductive element such as is used as a current conductor in partially or fully electrically operated motor vehicles. According to one embodiment, it is a conductor element, for example, as is used in the area of a high-voltage storage device and/or an electrical machine of a partially or fully electrically operated motor vehicle. Such a conductor element is also referred to as a conductor rail or flat conductor. Typical cross-sectional shapes are in particular rectangular, with the short side of the rectangle having a length of 1-4 mm, for example, and the long side having a length of 5-30 mm, for example. The present method makes it possible to use existing installation space efficiently. Vehicle-specific, expensive tools can be saved and replaced by cheaper and reusable, because they are adaptable.

The invention also relates to a device for forming, in particular for carrying out a method according to the invention, comprising at least two clamping points designed to be displaceable relative to one another, which are designed for clamping a workpiece, a first clamping point being designed as a floating bearing and a second clamping point being designed as a fixed bearing is. It has been found that with the aforementioned combination of floating bearing and fixed bearing, gentle and flexible forming with regard to the degree of forming that can be achieved can be made possible. The clamping points are implemented using tools, which expediently have holding sections which bear geometrically, preferably over an area, on the respective workpiece to be formed. The shape of the tools or holding sections is expediently based on the shape of the respective workpiece. If the workpiece or the starting material is a flat strip/flat material that extends in a longitudinal direction, the holding sections are designed as clamping sections, for example. In this case, one of the tools is designed in such a way that a translational movement of the workpiece during forming is made possible in at least one spatial direction.

According to one embodiment, the device includes an industrial robot, wherein the industrial robot includes at least one of the tools or at least one tool. Alternatively, two or more industrial robots are used, with each of the industrial robots having a tool. The industrial robot is in particular a multi-axis robot arm which is designed to guide the tools accordingly in order to achieve the desired deformations. Alternatively, at least the tool, which is designed as a fixed bearing, can be designed as a rigid, non-displaceable tool, or alternatively vice versa.

Further advantages and features result from the following description of an embodiment of the method or a workpiece and a device with reference to the attached figures.

• 1: eine Ausführungsform eines Werkstücks beim Anordnen zweier Werkzeuge;
• 2: das aus der 1 bekannte Werkzeug nach einem ersten Umformvorgang;
• 3: das aus der 2 bekannte Werkzeug nach einem weiteren Umformvorgang;
• 4: das aus der 3 bekannte Werkstück nach einem weiteren Umformvorgang.

Show it:

• 1 1: an embodiment of a workpiece when arranging two tools;
• 2 : that from the 1 known tool after a first forming process;
• 3 : that from the 2 known tool after a further forming process;
• 4 : that from the 3 known workpiece after a further forming process.

1 shows a workpiece 10 schematically, which is, for example, an elongate workpiece, in particular a flat strip or flat material, which extends along a longitudinal direction L. Numeral 21 designates a first tool, and numeral 22 designates a second tool. In the present case, the tools 21 and 22 are designed as clamps, adapted to the geometry of the workpiece 10 . To hold the workpiece 10, the clamps can be folded shut as outlined by the arrows. Here, the workpiece 10 at a first clamping point 11 and held at a second clamping point 12. The clamping points 11 and 12 are spaced apart from one another along the longitudinal direction L, so that a deforming region 40 is or will be shaped or formed between them. By moving the first tool 21 from a first position to a second position, the forming area 40 can be plastically deformed, with the workpiece 10 being able to move translationally at the first clamping point 11 or the second clamping point 12 relative to the respective tool 21 or 22. Advantageously, the deformation area 40 can deform freely. The final geometry of the forming area 40 is expediently obtained from the end position of the clamping points 11 and 12 to one another or the material of the workpiece 10. The shift from the first position to the second position suitably includes several partial movements, with these partial movements in the 2 , 3 and 4 are shown schematically.

2 shows that from the 1 known workpiece 10. In a first partial movement, this was rotated or twisted about the longitudinal axis L, see the shape of the forming area 40. In the present embodiment, the workpiece 10 is held at the first clamping point 11 in such a way that it can move in a translatory manner. In particular, a movement or displacement, as indicated by the arrow provided with the letter V, is made possible in the present case. In this way, among other things, it can be achieved that the material in the forming region 40 does not taper or thin in an impermissible manner, which would be problematic in particular if the workpiece is used for conducting electricity.

3 shows the workpiece 10 known from the previous figures, this being bent about an axis of rotation D. Here, as outlined, the deformed area 40 is deformed further.

4 12 shows a further partial movement, which leads to a further deformation of the forming region 40. It is also sketched that a movement or displacement occurs along the direction V in the area of the first clamping point 11 . This is oriented transversely to the longitudinal direction L of the workpiece 10 .

What is not shown here is that several tools can also be used simultaneously or one after the other. A workpiece can also have a large number of deformed areas, which means that, for example, flat conductors with complex three-dimensional geometries can be produced.

Reference List

10

workpiece

11

first place/clamping point

12

second place/clamping place

21

first tool

22

second tool

22

jaw

40

forming area

a

Distance

D

axis of rotation

L

longitudinal direction

V

shift

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102018217785 A1 [0002]

Claims (14)

Method for regionally forming slender workpieces (10), comprising the steps: - Providing a workpiece (10) which extends along a longitudinal direction (L); - Holding the workpiece (10) at a first clamping point (11) with a first tool (21); - Holding the workpiece (10) at a second clamping point (12) with a second tool (22) which is arranged along the longitudinal direction (L) at a distance from the first clamping point (11), whereby between the clamping points (11, 12) a reforming area (40) is formed; - Moving the first tool (21) from a first position to a second position for plastic deformation of the forming area (40), the workpiece (10) being at the first clamping point (11) or the second clamping point (12) relative to the respective tool (21, 22) can move translationally. procedure after claim 1 , wherein the position of the second tool (22) is not changed, and wherein the workpiece (10) can move relative to the first tool (21) at the first clamping point (11). procedure after claim 1 or 2 , wherein the shifting from the first position to the second position comprises a plurality of partial movements. procedure after claim 3 , wherein the partial movements include at least one of the following: bending, rotating, shifting. Method according to one of the preceding claims, in which the movement of the workpiece (10) relative to the respective tool (21, 22) is a translation in at least one spatial direction. Method according to one of the preceding claims, in which the tools (21, 22) for holding the workpiece (10) have holding sections (23). procedure after claim 6 , comprising the step of: - using tools (21, 22) which have holding sections (23) of different lengths, as a result of which clamping points (21, 22) of different lengths are formed. Method according to one of the preceding claims, comprising the step: - Deforming the workpiece (10) in a plurality of forming areas (40). Method according to one of the preceding claims, comprising the step: - Use, in particular simultaneous or sequential use, of more than two tools (21, 22). procedure after claim 9 , comprising the step of: - applying the tools (21, 22) in such a way that forming regions (40) of different lengths are formed. Method according to one of the preceding claims, comprising the step: - Tempering, in particular heating, the forming area (40). Workpiece, in particular conductor element, produced by a method according to one of the preceding claims. Device for forming, in particular for carrying out a method according to one of Claims 1 until 11 , comprising at least two clamping points (11, 12) designed to be displaceable relative to one another, which are designed for clamping a workpiece (10), a first clamping point (11) being designed as a floating bearing, and a second clamping point (12) being designed as a fixed bearing . device after Claim 13 , comprising at least one industrial robot, wherein the industrial robot comprises at least one tool (21, 22).

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