EP3917696B1 - Method and device for producing a rod-shaped element - Google Patents

Description

TECHNICAL FIELD

The present disclosure relates to a method and a device for producing a rod-shaped element and such a rod-shaped element.

TECHNOLOGICAL BACKGROUND

Methods and devices are known from the prior art for producing solid rod-shaped elements made of metal, for example metal rods or metal rods. For this purpose, a prefabricated solid cylindrical billet is formed into a solid rod-shaped element made of metal, ie in particular rolled or drawn. JP 2003-290814 A discloses a cold-formed tube containing a plurality of yarns, the yarns being made of metal (stainless steel).

Rod-shaped elements produced in this way are used, for example, to realize, reinforce and reinforce buildings. In order to enable the absorption of high tensile loads, the diameter of the respective rod-shaped element is adapted to the tensile load to be absorbed. However, an increase in the diameter is accompanied by an increase in the weight of the rod-shaped element. There are therefore limits to the use of such rod-shaped elements, particularly for reinforcing and reinforcing buildings.

SUMMARY

There is therefore a need for a rod-shaped element and for a method and a device for its production, which overcome at least one of the aforementioned disadvantages. Furthermore, there is a need for a rod-shaped element with a high tensile strength and at the same time low weight. The invention is defined by independent claims 1, 11 and 12; other aspects of the invention are set out in the dependent claims.

• Bereitstellen eines Rohres aus einem Metall, wobei das Rohr einen Außendurchmesser und eine Längsrichtung aufweist,
• Bereitstellen mindestens eines Stranges mit einer Mehrzahl von Garnen, wobei zumindest eines der Garne Kohlenstofffasern aufweist,
• Einbringen des mindestens einen Stranges in das Rohr, so dass sich der mindestens eine Strang in der Längsrichtung in dem Rohr erstreckt, und
• Kaltumformen des Rohres mit dem mindestens einen darin eingebrachten Strang mit einem Umformwerkzeug, so dass der Außendurchmesser des Rohres vor dem Kaltumformen größer ist als der Außendurchmesser des Rohres nach dem Kaltumformen.

According to a first aspect of the present disclosure, a method for producing a rod-shaped element is therefore proposed, the method having the steps:

• Providing a tube made of a metal, the tube having an outside diameter and a longitudinal direction,
• Providing at least one strand with a plurality of yarns, at least one of the yarns having carbon fibers,
• Introducing the at least one strand into the tube so that the at least one strand extends in the longitudinal direction in the tube, and
• Cold forming the tube with the at least one strand introduced therein using a forming tool, so that the outside diameter of the tube before cold forming is larger than the outside diameter of the tube after cold forming.

The idea on which this method is based is to provide a structure, i.e. a rod-shaped element, with high tensile strength by introducing the at least one strand into a tube made of metal. In other words, the at least one strand forms the core of the rod-shaped element, with the tube extending around the core like a jacket.

Due to the lower material density of carbon fibers compared to metals, the weight of the rod-shaped element is reduced compared to a solid rod-shaped element made of metal with the same outer diameter, with comparable tensile strength.

The tube forming the jacket of the arrangement also offers the advantage that it protects the internal core, i.e. the at least one strand, from environmental influences, for example from abrasion caused by concrete surrounding the rod-shaped element in the installed state. Such environmental influences could otherwise lead to destruction or impairment of the strand.

In one embodiment, the elongation of the tube is greater than the elongation of the at least one strand, while at the same time the tensile strength of the at least one strand is greater than the tensile strength of the tube.

The production of pipes from metal is known in principle. Essentially, seamless pipes, i.e. pipes without a weld seam in the longitudinal direction, and pipes welded in the longitudinal direction, so-called longitudinally welded pipes, are produced using the known processes.

If a seamless pipe is used, the at least one strand is inserted axially into the opening of the pipe provided. For longitudinally welded pipes, the step of introducing the strand elsewhere is described in detail below.

In addition to the weight reduction, the introduction of the at least one strand also has the advantage that, in one embodiment, the carbon fibers introduced increase the weight Tensile strengths can be achieved compared to a solid rod-shaped element made of metal or a pipe made of metal with the same outside diameter. Thus, by introducing the at least one strand, an advantage can be achieved compared to a comparable pipe made of metal without a core.

In one embodiment, the cold forming of the tube with the at least one strand arranged therein also has a positive effect on the overall tensile strength of the rod-shaped element. Cold forming processes are used, for example, to transform a hollow metallic base body into a finished tube. Through cold forming, the inside and outside diameter of a pipe can be changed and dimensioned very precisely. Cold forming is also suitable for improving the surface properties of the pipe.

In addition, cold forming is accompanied by work hardening, which means that the properties of the pipes produced in this way can be specifically changed. Through work hardening it is possible to increase the material strength and thus also the tensile strength of the formed pipe.

Cold forming in the sense of the present disclosure is understood to mean forming at a temperature that is lower than the recrystallization temperature of the metal.

With cold forming and the associated work hardening, not only can the properties of the pipe be changed, but also by "shrinking" the pipe onto the at least one strand and the resulting positive and/or non-positive connection between the at least one strand and the tube the properties of the entire rod-shaped element can be improved.

In one embodiment, the cold forming of the tube with the strand extending therein provides a tight positive fit between the tube and the at least one strand extending therein in the radial direction, so that the at least one strand cannot move in the radial direction relative to the tube .

In one embodiment, the cold forming provides a frictional connection between the tube and the at least one strand extending therein, so that the frictional force between the tube and the at least one strand prevents a relative movement between the tube and the at least one strand in the axial direction. The non-positive connection thus produces a rod-shaped element whose tensile strength in one embodiment is greater than the tensile strength of a solid rod-shaped element made of metal or a pipe made of metal with the same outside diameter.

In one embodiment of the present disclosure, the forming tool for cold forming and the tube are therefore designed and arranged such that after cold forming, the tube and the at least one strand are non-positively connected to one another.

In one embodiment of the present disclosure, after cold forming, the tube and the at least one strand are non-positively connected to one another over the entire extent of the strand in the longitudinal direction of the tube.

It is understood that the pipe can be deformed with the forming tool, depending on how it is set, in such a way that the pipe is pressed onto the at least one strand. As a result of the pressing, the force-fitting connection is created. The non-positive connection of the at least one strand to the pipe ensures that the at least one strand can no longer move in the axial direction relative to the pipe after cold forming. In the radial direction there is then an isotropic positive fit of the at least one strand.

Rubbing a plurality of yarns with carbon fibers against one another or a plurality of carbon fibers against one another can result in at least individual carbon fibers being weakened or destroyed. This permanently changes the properties of the strand formed from the yarns, e.g. its tensile strength is reduced. In an embodiment in which the cold forming causes a frictional connection between the tube and the at least one strand, friction or influence between the individual yarns and/or between individual carbon fibers with one another is therefore reduced. In one embodiment, cold forming can ensure that the yarns and/or, in an embodiment with several strands, the individual strands no longer move against each other or only to a lesser extent. This means that the yarns or strands within the tube are protected by cold forming.

In one embodiment, the step of cold forming is carried out by cold rolling or cold pilger rolling of the tube with the at least one strand extending therein in the longitudinal direction in a cold pilgrim rolling mill. It goes without saying that in this embodiment the forming tool is formed by rollers or rollers.

Cold pilger rolling is a common forming process used to adjust the inside and outside diameters of a pipe. The pipe is gripped by two calibrated rollers or rollers, which define the outside diameter of the tube, and rolled out so that the rollers or rollers reduce the outside diameter of the incoming tube to the outside diameter of the rod-shaped element.

In a further embodiment, the cold forming is carried out by cold drawing the tube together with the at least one strand extending therein in the longitudinal direction through a drawing die. In this embodiment, the forming tool is formed by the drawing die.

When cold drawing pipes, a basic distinction is made between processes without an internal tool, the so-called hollow drawing, and processes with an internal tool, i.e. in particular core drawing and bar drawing. If the cold forming is carried out in one embodiment of the method according to the present disclosure by cold drawing, this basically takes place without an internal tool inside the tube. However, the drawing process of the pipe with the at least one strand extending therein together through the drawing die can be understood in one embodiment as pulling the pipe onto the at least one strand. The at least one strand is understood as an internal tool. In one embodiment, by appropriately dimensioning the tube, the at least one strand and the drawing die, it is important to bring about close contact between the tube and the at least one strand, but without impairing or even damaging the strand by force in the radial direction.

In one embodiment of the disclosure, the cold forming is carried out by cold drawing the tube together with the at least one strand in the longitudinal direction through a drawing die. In this embodiment, the drawing die forms the forming tool in the sense of the present application. In one embodiment, an inner diameter of the drawing die and an outer diameter of the pipe are selected before cold drawing so that after cold drawing the pipe and the at least one strand are non-positively connected.

In one embodiment of the present disclosure, after cold drawing, the tube and the at least one strand are non-positively connected over the entire extent of the strand in the longitudinal direction of the tube.

Carbon fibers in the sense of the present disclosure are also referred to as carbon fibers or carbon fibers. They are manufactured industrially and converted into graphite-like carbon through chemical reactions adapted to the raw material. Carbon fibers have high strength and stiffness combined with low elongation at break in the axial direction.

A number of carbon fibers are combined into a yarn for further processing. Such yarns with carbon fibers are also referred to as multifilament yarns or rovings. According to the present disclosure, the term yarn is understood to mean a long, thin structure. In one embodiment, a yarn in the sense of the present disclosure can also have fibers made of one or more other materials in addition to the carbon fibers. The yarn serves as an intermediate product for producing a strand in the sense of the present disclosure.

In one embodiment of the present disclosure, the at least one strand is selected from a rope, a woven fabric, a braid, a knitted fabric, a bundle, and a multiaxial scrim, or any combination thereof.

In one embodiment, the at least one strand, which has a plurality of yarns, also contains one or more yarns made of or with one or more materials other than carbon fibers.

For example, in one embodiment, the strand additionally has a yarn with fibers made of a material with at least one property that is different from the properties of the carbon fibers. Such an additional property can have a positive effect on the characteristics of the rod-shaped element. For example, in one embodiment, a hybrid strand with at least one additional yarn with aramid fibers and / or glass fibers can be introduced, for example to increase the linear yield strength of the rod-shaped element produced in this way.

In one embodiment of the present disclosure, the at least one strand has a proportion of at least 50% carbon fibers.

In one embodiment of the present disclosure, the at least one strand has a content of at least 90% carbon fibers.

In one embodiment of the present disclosure, the at least one strand consists entirely of carbon fibers.

In one embodiment of the present disclosure, after the cold forming step, the rod-shaped element is cut to a desired length.

• Bereitstellen eines Streifens aus einem Metallblech, wobei der Streifen eine Längsrichtung und eine Querrichtung aufweist,
• Biegen des Streifens in der Querrichtung, so dass ein rohrförmiger Hohlkörper mit einer zylindrischen Querschnittsfläche entsteht,
• Zuschweißen des rohrförmigen Hohlkörpers mit einer Längsnaht, wobei sich die Längsnaht in der Längsrichtung erstreckt, so dass ein längsgeschweißtes Rohr entsteht,
• wobei das Einbringen des mindestens einen Stranges in das Rohr durch Aufbringen des Stranges auf den Streifen vor dem Zuschweißen erfolgt.

In one embodiment of the present disclosure, providing the tube includes the steps of:

• Providing a strip made of a metal sheet, the strip having a longitudinal direction and a transverse direction,
• Bending the strip in the transverse direction to form a tubular hollow body with a cylindrical cross-sectional area,
• Welding the tubular hollow body with a longitudinal seam, the longitudinal seam extending in the longitudinal direction, so that a longitudinally welded pipe is created,
• wherein the at least one strand is introduced into the pipe by applying the strand to the strip before welding.

In this embodiment, a longitudinally welded pipe is used as a jacket for the at least one strand. The at least one strand is introduced into the pipe or applied to the strip of sheet metal that will form the pipe before the pipe is welded shut, i.e. before the pipe is actually completed. This embodiment therefore enables the at least one strand to be easily inserted into the pipe. Unlike a seamless pipe, it is not necessary to insert at least one strand axially into the pipe.

In principle, it is irrelevant when the strand is applied to the strip of metal sheet, i.e. brought into engagement with the sheet, as long as it is applied before welding.

• Vorbiegen des Streifens in der Querrichtung, so dass ein rinnenförmiger Hohlkörper mit einer sich in der Längsrichtung erstreckenden Öffnung entsteht, und
• Fertigbiegen des Streifens in der Querrichtung, so dass ein rohrförmiger Hohlkörper mit einer zylindrischen Querschnittsfläche entsteht,
• wobei das Einbringen des mindestens einen Stranges in das Rohr vor dem Fertigbiegen des Streifens und durch die Öffnung in den rinnenförmigen Hohlkörper erfolgt

However, in one embodiment of the present disclosure, bending the strip in the transverse direction includes the steps of:

• Pre-bending the strip in the transverse direction so that a channel-shaped hollow body is created with an opening extending in the longitudinal direction, and
• Finish bending the strip in the transverse direction so that a tubular hollow body with a cylindrical cross-sectional area is created,
• wherein the at least one strand is introduced into the tube before the strip is fully bent and through the opening into the trough-shaped hollow body

Because the strip is pre-bent in the transverse direction and a channel-shaped hollow body is created, the at least one strand is guided in the channel created by the pre-bending when the at least one strand is introduced. When introducing the at least one strand, it is thus ensured that the at least one strand cannot slip in its inserted position on the strip.

In one embodiment of the present disclosure, the at least one strand is introduced into the pipe and the pipe is cold formed with the at least one strand in a production line.

The term "in a production line" as used in the present disclosure means that the introduction of the at least one strand into the pipe and the cold forming take place in the same production facility. In one embodiment, the strand is introduced into the pipe in one section of the pipe, while another section of the same pipe is already being cold-formed. Furthermore, in one embodiment, the pipe is also welded shut between the location at which the at least one strand is introduced and the location at which the pipe is cold-formed.

In one embodiment of the present disclosure, the welding and cold forming occur at a distance in a range of 2 m to 4 m.

It has surprisingly been found that a spatial distance of 2 m to 4 m between the location at which the welding step is carried out and the location at which the cold forming step is carried out has a positive effect on the properties of the rod-shaped product produced Element affects. If the welding and cold forming take place at a smaller or further distance from one another, this can lead to problems with the cold forming of the pipe with the at least one strand extending therein.

In one embodiment of the present disclosure, the tube is made of stainless steel. Stainless steel has the advantage of a comparatively high tensile strength compared to other metals and a high level of resistance, for example to environmental influences.

In an embodiment of the method according to the present disclosure, the outside diameter of the tube is larger before cold forming, for example before cold drawing, than after cold forming.

In one embodiment of the present disclosure, the forming tool and an outer diameter of the tube before cold forming are selected such that a wall thickness of the tube before cold forming is smaller than after cold forming. In one embodiment of the present disclosure, an inner diameter of the drawing die and an outer diameter of the tube before cold drawing are selected such that a wall thickness of the tube before cold drawing is smaller than after cold drawing.

By cold forming, in particular by cold drawing, material of the pipe is displaced by the forming tool, for example the drawing die. The drawing die and the tube are expediently chosen so that the material of the tube is displaced concentrically inwards and so the wall thickness of the tube is greater after cold drawing than before cold drawing.

According to a second aspect of the present disclosure, there is proposed a rod-shaped element obtainable by any embodiment of the method according to the present disclosure.

Through each of the previously described embodiments or each combination of the previously described embodiments of the method, a rod-shaped element is produced which has a high tensile strength and a reduced dead weight compared to a solid rod-shaped element made of metal with the same tensile strength. Through cold forming, the associated work hardening of the pipe and the associated close positive fit between the pipe and the at least one strand, the properties of the pipe are changed and its tensile strength is thus increased.

A rod-shaped element produced in this way has at least one strand inside, consisting of a plurality of yarns, at least one of the yarns having carbon fibers, and a metal tube surrounding the strand, which surrounds the at least one strand.

In one embodiment of the present disclosure, the rod-shaped element is obtained with an embodiment of the method in which the cold forming leads to a non-positive connection between the at least one strand and the tube. It is understood that in this embodiment the non-positive connection between the tube and the at least one strand is provided during cold forming by pressing the tube onto the at least one strand. The combination of pressing and work hardening creates a rod-shaped element whose tensile strength exceeds both the tensile strength of a solid rod-shaped element made of metal with the same outside diameter and the tensile strength of a cold-formed tube with the same outside diameter.

According to a further aspect of the present disclosure, a rod-shaped element is proposed which has a tube made of a metal, the tube having a longitudinal direction, and at least one strand extending longitudinally in the tube, the at least one strand having a plurality of yarns Has carbon fibers and wherein the tube and the at least one strand are non-positively connected.

In one embodiment of the present disclosure, the tube and the at least one strand are non-positively connected to one another over the entire extent of the strand in the longitudinal direction of the tube.

• eine Zuführeinrichtung für ein Rohr aus Metall,
• eine Zuführeinrichtung für mindestens einen Strang mit einer Mehrzahl von Garnen,
• eine Umformeinrichtung, wobei die Umformeinrichtung ein Umformwerkzeug aufweist,
• wobei die Zuführeinrichtung für das Rohr und die Zuführeinrichtung für den mindestens einen Strang derart ausgestaltet und angeordnet sind, dass sich in dem Betrieb der Vorrichtung der Strang in Materialflussrichtung vor dem Umformwerkzeug in dem Rohr erstreckt, und dass das Rohr aus Metall mit dem sich darin erstreckenden mindestens einen Strang mit dem Umformwerkzeug umformbar sind.

According to a further aspect, the present disclosure also relates to a device for producing a rod-shaped element, the device comprising:

• a feed device for a metal pipe,
• a feed device for at least one strand with a plurality of yarns,
• a forming device, the forming device having a forming tool,
• wherein the feed device for the tube and the feed device for the at least one strand are designed and arranged such that during operation of the device, the strand extends in the material flow direction in front of the forming tool in the tube, and that the tube made of metal extends with the metal tube extending therein at least one strand can be formed with the forming tool.

Insofar as aspects of the disclosure are described below with regard to a device for producing a rod-shaped element, these also apply to the corresponding previously described method for producing a rod-shaped element and vice versa. To the extent that the method is carried out with a device according to this disclosure, the device has the corresponding facilities and devices for this. In particular, embodiments of the device are suitable for carrying out the previously described embodiments of the method.

In one embodiment of the present disclosure, the feeding devices on the one hand and the forming device on the other hand are implemented in separate, spatially separated production systems. In a further embodiment, the feed devices for the pipe and the at least one strand as well as the forming device are implemented in a single production system, this production system being the claimed device.

In one embodiment of the present disclosure, the forming device is a device for cold forming a metal tube.

In one embodiment of the invention, the forming tool is a tool for performing forming of the pipe in accordance with DIN 8580.

In one embodiment of the present disclosure, the forming device is a drawing bench, wherein the drawing bench has a drawing die as a forming tool and wherein, during operation of the device, the strand extends in the material flow direction in front of the drawing die in the tube, so that the tube is made of metal and the at least one Strand can be pulled together through the drawing die.

In one embodiment of the present disclosure, the draw bench is a continuous draw bench.

• eine Zuführeinrichtung für einen Streifen aus einem Metallblech, wobei der Streifen eine Längsrichtung und eine Querrichtung aufweist,
• eine Biegeeinrichtung zum Biegen des Streifens in der Querrichtung, so dass ein rohrförmiger Hohlkörper mit einer zylindrischen Querschnittsfläche entsteht, und
• eine Schweißeinrichtung zum Zuschweißen des rohrförmigen Hohlkörpers mit einer Längsnaht, wobei sich die Längsnaht in der Längsrichtung erstreckt, so dass ein längsgeschweißtes Rohr entsteht, und
• wobei die Zuführeinrichtung für das Rohr und die Zuführeinrichtung für den mindestens einen Strang derart ausgestaltet und angeordnet sind, dass der Strang in Materialflussrichtung vor der Schweißeinrichtung auf den Streifen aus dem Metallblech aufbringbar ist.

In one embodiment of the present disclosure, the tube feeding device comprises:

• a feed device for a strip made of a metal sheet, the strip having a longitudinal direction and a transverse direction,
• a bending device for bending the strip in the transverse direction to form a tubular hollow body with a cylindrical cross-sectional area, and
• a welding device for welding the tubular hollow body with a longitudinal seam, the longitudinal seam extending in the longitudinal direction, so that a longitudinally welded pipe is created, and
• wherein the feed device for the pipe and the feed device for the at least one strand are designed and arranged such that the strand can be applied to the strip of metal sheet in the material flow direction in front of the welding device.

In one embodiment of the present disclosure, the bending device for bending the strip of the metal sheet in the transverse direction has a pre-bending device and a final bending device, the pre-bending device being set up and arranged such that the pre-bending device bends the strip in the transverse direction into a trough-shaped hollow body with a opening extending in the longitudinal direction, and wherein the finishing bending device is set up and arranged in such a way that the finishing bending device finishes bending the strip in the transverse direction into a tubular hollow body with a cylindrical cross-sectional area and wherein the feed device for the at least one strand is designed and arranged in such a way that the feed device applies the at least one strand in the material flow direction between the pre-bending device and the final bending device onto the trough-shaped hollow body made of metal bleach.

In one embodiment of the present disclosure, the device has a control device, the control device being effectively connected to the feed device for the strip, to the feed device for the at least one strand and to the welding device in such a way that the control device has a feed speed during operation of the device the feed device for the strip, a feed speed of the feed device for the at least one strand and a welding speed of the welding device.

In one embodiment, the control device controls the feed speeds and welding speed in such a way that the non-positive connection between the pipe and the at least one strand is influenced. Depending on the control of the In one embodiment, the frictional connection between the pipe and the at least one strand is set at corresponding speeds, so that, for example, the pipe and the at least one strand are uniformly connected to one another in a force-fitting manner over the entire extent of the strand in the longitudinal direction of the pipe.

In one embodiment, the control device also controls the processing speed of the forming device.

In one embodiment, the control of the processing speed can also influence the frictional connection between the pipe and the at least one strand.

It is understood that in one embodiment the control device comprises a computer or a processor and a computer program running on it.

In one embodiment of the present disclosure, the device is designed such that there is a distance of 2 m to 4 m between the welding device and the forming tool of the forming device, for example the drawing die of the drawing bench. In such an embodiment, the welding device and the forming tool are components of a single production system.

BRIEF DESCRIPTION OF THE FIGURES

Figur 1

ist ein Ablaufdiagramm einer Implementierung des Verfahrens gemäß der vorliegenden Offenbarung zum Herstellen eines stabförmigen Elementes gemäß einer Ausführungsform der vorliegenden Offenbarung.

Figur 2

ist ein Ablaufdiagramm einer weiteren Implementierung des Verfahrens gemäß der vorliegenden Offenbarung zum Herstellen eines stabförmigen Elementes gemäß einer anderen Implementierung der vorliegenden Offenbarung.

Figur 3

ist eine schematische Draufsicht auf eine Implementierung der Vorrichtung zum Herstellen eines stabförmigen Elementes zum Realisieren des Verfahrens aus Figur 2.

Figur 4

ist eine schematische Querschnittsansicht einer Implementierung des stabförmigen Elementes, welches es mit dem Verfahren aus Figur 2 bzw. der Vorrichtung aus Figur 3 erhalten wurde.

Further advantages, features and possible applications of the present disclosure will become clear from the following description of an embodiment and the associated figures. The foregoing general description and the following detailed description of an implementation of the present disclosure are better understood when considered in conjunction with the accompanying drawings. The implementations shown are not limited to the embodiments described in detail. In the figures, similar elements are designated with identical reference numerals.

Figure 1

is a flowchart of an implementation of the method according to the present disclosure for producing a rod-shaped element according to an embodiment of the present disclosure.

Figure 2

is a flowchart of another implementation of the method according to the present disclosure for producing a rod-shaped element according to another implementation of the present disclosure.

Figure 3

is a schematic top view of an implementation of the device for producing a rod-shaped element for implementing the method from Figure 2.

Figure 4

is a schematic cross-sectional view of an implementation of the rod-shaped element comprising the method Figure 2 or the device Figure 3 was received.

DETAILED DESCRIPTION

Figure 1 is a flowchart of an implementation of the method for manufacturing a rod-shaped element according to the present disclosure. In a first step 100, a stainless steel tube is provided, the stainless steel tube having a longitudinal direction. In a further step 101, simultaneously with the first step 100, a braid is provided, which is formed from a plurality of yarns made of carbon fibers. In the implementation shown, the strand formed in this way consists of 100% carbon fibers.

In the implementation shown, the stainless steel pipe is a seamless pipe, i.e. without a weld seam in the longitudinal direction, and the strand is inserted axially into the stainless steel pipe in a further step 102 so that the strand extends in the longitudinal direction in the pipe. After introducing 102 the strand into the stainless steel tube, the tube is cold-formed with the strand extending in the longitudinal direction in the tube in step 103 using a forming tool. In the implementation shown, cold forming is carried out by cold rolling in a cold pilgrim mill. After cold pilger rolling 103, the stainless steel tube and the strand are non-positively connected to one another over the entire extent of the strand in the longitudinal direction of the tube.

Figure 2 shows a flowchart of a further implementation of the method for producing a rod-shaped element. The individual steps of the method according to this implementation take place in a production plant, with a strip of stainless steel sheet and the strand being fed to the production plant as starting materials.

When referring to Figure 2 In the method described, the step of providing 100 the stainless steel tube therefore also includes the actual production of the stainless steel tube. For this purpose, the provision 100 of the pipe initially includes, in step 104, the provision of a strip made of a stainless steel sheet. The strip has a longitudinal direction and a transverse direction. In step 105 the strip is bent transversely to the pipe.

To bend the tube, the strip is first pre-bent in step 107, so that a channel-shaped hollow body with an opening extending in the longitudinal direction is created. At the same time, in step 101, a strand containing a plurality of carbon fiber yarns is provided. In the implementation shown, the strand consists of a braid with a proportion of 60% carbon fibers. After pre-bending 107 of the stainless steel sheet, the strand is introduced in step 102 in the longitudinal direction into the trough-shaped hollow body. The channel shape guides the strand on the stainless steel sheet so that the strand cannot slip off the stainless steel sheet. After the strand has been introduced into the channel, the stainless steel sheet is completely bent in the transverse direction in step 108, so that a tubular hollow body with a cylindrical cross-sectional area is created, which wraps around the strand. In step 106, the tubular hollow body, which consists of the stainless steel sheet, is welded with a longitudinal seam to form a longitudinally welded stainless steel tube. This ends step 100 of providing the pipe.

After welding 106, the pipe is cold formed in step 103. In the implementation of the procedure according to Figure 2 Cold forming is carried out by cold drawing. For this purpose, the pipe is pulled together with the strand in the longitudinal direction through a drawing die as a forming tool. After cold drawing 103, the stainless steel tube and the strand are non-positively connected to one another over the entire extent of the strand in the longitudinal direction of the tube.

Figure 3 shows a schematic top view of a device 1 for producing a rod-shaped element 20 in an implementation of the present disclosure. The device 1 for producing the rod-shaped element 20 carries out the method for producing the rod-shaped element 20, as described with reference to Figure 2 was previously described.

Figure 4 additionally shows a cross-sectional view in a sectional plane perpendicular to the longitudinal direction of the rod-shaped element 20, which is connected to the device 1 Figure 3 was produced.

The device 1 has a feed device 2 for the stainless steel tube 3, the feed device 2 being composed of a plurality of devices.

The feed device 2 for the stainless steel tube 3 initially includes a feed device 8 for the strip 9 made of stainless steel sheet. The strip 9 has a longitudinal direction and a transverse direction, with the extent in the longitudinal direction being significantly larger than in the transverse direction.

In addition, the feed device 2 for the stainless steel tube 3 has a bending device 10 for bending the strip 9. The bending device 10 consists of a pre-bending device 11 and a finished bending device 12. The strip is first made with the pre-bending device 11 9 pre-bent so that the trough-shaped hollow body 16 is created. The strand 5 is introduced into the trough-shaped hollow body 16 using a feed device 4. The strand 5 is placed and guided centrally on the strip 9 through the channel of the channel-shaped hollow body 16, so that the strand 5 cannot slip off the strip 9.

After the strand 5 has been applied to the sheet metal strip 16, the finished bending device 12 is used to bend the trough-shaped hollow body 16 into a tubular hollow body 13 with a circular cross-section, the strand 5 extending within the tubular hollow body 13 in the longitudinal direction. Using a welding device 14, which is also part of the feed device 2 for the pipe 3, the tubular hollow body 13 is then welded with a longitudinal seam 19, so that the longitudinal seam 19 extends in the longitudinal direction and a longitudinally welded stainless steel pipe 3 is created.

The drawing die 7 of a drawing bench 6 is provided behind the welding device 14 at a distance d of 3 m. To carry out the drawing process, the drawing bench 6 has, in addition to the drawing die 7, a motor-driven drawing carriage 17 with a clamping cylinder 18 mounted on it for gripping the tube 3 behind the drawing die 7.

By pulling the tube 3 with the strand 5 arranged therein together through the drawing die 7, the rod-shaped element 20 is created. The inner diameter of the drawing die 7 and the outer diameter of the stainless steel tube 3 before drawing are selected so that after cold drawing the stainless steel tube is like in Figure 4 wall thickness w shown. While the outside diameter of the pipe is reduced after cold drawing, the wall thickness w is larger after cold drawing than before cold drawing. By cold drawing, the tube 3 and the strand 5 are connected to one another in a force-fitting manner in the tube 3 behind the drawing die 7 over the entire extent of the strand 5 in the longitudinal direction. The strand 5 cannot slip within the tube 3 in the axial direction. A rod-shaped element 20 has been created with a tensile strength that exceeds the tensile strength of the cold-drawn tube.

A central control device 15 is electrically connected to the feed device 8 for the sheet metal strip 9, to the feed device 4 for the strand 5, to the welding device 14 and to the drawing bench 6. During operation of the system 1, the control device 15 controls the feed speeds of the strip 9, the strand 5 as well as the welding speed of the welding device 14 and the drawing speed of the drawing bench 6. By controlling the aforementioned speeds, the pipe 3 and the strand are behind the drawing die 7 5 over the entire extent of the strand 5 in the longitudinal direction in the tube 3 evenly connected to one another in a non-positive manner.

For the purposes of the original disclosure, it should be noted that all features as apparent to a person skilled in the art from the present description and the drawings as well as the claims, even if they were specifically described only in connection with certain other features, both individually and in Any combinations can be combined with other features or groups of features disclosed here, unless this has been expressly excluded or technical conditions make such combinations impossible or meaningless. The comprehensive, explicit presentation of all conceivable combinations of features is omitted here only for the sake of brevity and readability of the description.

While the disclosure has been illustrated and described in detail in the drawings and the foregoing description, this illustration and description is given by way of example only and is not intended to limit the scope as defined by the claims. The disclosure is not limited to the disclosed embodiments.

Variations of the disclosed embodiments will be apparent to those skilled in the art from the drawings, description and appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are claimed in different claims does not preclude their combination. Reference numerals in the claims are not intended to limit the scope.

Reference symbol list

1

Device for producing a rod-shaped element

2

Feeding device for a stainless steel tube

3

Stainless steel tube

4

Feeding device for a strand

5

strand

6

draw bench

7

Drawing die

8th

Feeding device for a strip

9

stripes

10

Bending device

11

Pre-bending device

12

Finished bending device

13

Tubular hollow body

14

Welding equipment

15

Control device

16

Channel-shaped hollow body

17

Pull wagon

18

Clamping cylinder

19

Longitudinal seam

20

Rod-shaped element

d

Distance

w

Wall thickness

100

Providing a pipe

101

Providing a strand

102

Insertion of a strand

103

Cold forming

104

Providing a strip

105

Bending a strip

106

Weld shut

107

Pre-bending a strip

108

Finish bending a strip

Claims (13)

1. Method for producing a rod-shaped element (20) wherein the method has the steps of

   providing (100) a pipe (3) made of a metal, wherein the pipe (3) has an outer diameter and a longitudinal direction,

   providing (101) at least one strand (5) having a plurality of yarns,

   wherein at least one of the yarns has carbon fibres,

   introducing (102) the at least one strand (5) into the pipe (3) such that the at least one strand (5) extends in the longitudinal direction in the pipe (3), and cold-forming (103) the pipe (3) having the at least one strand (5) introduced therein using a forming tool, such that the outer diameter of the pipe (3) prior to the cold-forming (103) is greater than the outer diameter of the pipe (3) after the cold-forming.
2. Method according to claim 1, characterised in that

   the providing (100) of the pipe (3) comprises the steps of

   providing (104) a strip (9) from a metal sheet, wherein the strip (9) has a longitudinal direction and a transverse direction,

   bending (105) the strip (9) in the transverse direction, such that a pipe-shaped hollow body (13) with a cylindrical cross-sectional area results,

   welding-shut (106) the pipe-shaped hollow body (13) with a longitudinal seam (19), wherein the longitudinal seam (19) extends in the longitudinal direction, such that a longitudinally-welded pipe (3) results,

   wherein the introduction (102) of the at least one strand (5) into the pipe (3) is carried out by mounting the strand (5) onto the strip (9) prior to the welding-shut (106).
3. Method according to claim 2, characterised in that the bending (105) of the strip (9) in transverse direction comprises the steps of

   pre-bending (107) the strip (9) in the transverse direction, such that a channel-shaped hollow body (16) results having an opening extending in the longitudinal direction, and

   finish-bending (108) the strip (9) in the transverse direction, such that a pipe-shaped hollow body (13) having a cylindrical cross-sectional area results,

   wherein the introduction (102) of the at least one strand (5) into the pipe (3) is carried out prior to the finish-bending (108) of the strip (9) and through the opening into the channel-shaped hollow body (16).
4. Method according to any of the preceding claims, characterised in that the introduction (102) of the at least one strand (5) into the pipe (3) and the cold-forming (103) of the pipe (3) with the at least one strand (5) takes place in a production line.
5. Method according to claim 2 or 3, characterised in that the welding-shut (106) and the cold-forming (103) take place at a distance (d) in a range from 2 m to 4 m.
6. Method according to any of the preceding claims, characterised in that the pipe (3) consists of a stainless steel.
7. Method according to any of the preceding claims, characterised in that the at least one strand (5) is selected from a rope, a fabric, a braid, a knitted wire and a multiaxial scrim or any combination thereof.
8. Method according to any of the preceding claims, characterised in that the at least one strand (5) has a proportion of at least 50% carbon fibres.
9. Method according to any of the preceding claims, characterised in that the cold-forming (103) is carried out by cold-drawing the pipe (3) together with the at least one strand (5) in the longitudinal direction through a drawing die (7), wherein an inner diameter of the drawing die (7) and an outer diameter of the pipe (3) prior to the cold-drawing are selected such that after the cold-drawing the pipe (3) and the at least one strand (5) are force-fittingly joined.
10. Method according to any of the preceding claims, characterised in that an inner diameter of the drawing die (7) and an outer diameter of the pipe (3) prior to the cold-drawing are selected such that a wall thickness (w) of the pipe (3) prior to the cold-drawing is smaller than after the cold-drawing.
11. Rod-shaped element (20) which has a pipe (3) made of a metal, wherein the pipe (3) has a longitudinal direction, at least one strand (5) extending in the longitudinal direction in the pipe (3), wherein the at least one strand (5) has a plurality of yarns having carbon fibres and wherein the pipe (3) and the at least one strand (5) are force-fittingly joined by means of a cold-forming process.
12. Device (1) for producing a rod-shaped element (20), wherein the device (1) has a supply apparatus (2) for a pipe (3) made of metal,

    a supply apparatus (4) for at least one strand (5) with a plurality of yarns, a forming apparatus, wherein the forming apparatus has a forming tool, wherein the forming apparatus is a cold-forming apparatus;

    wherein the supply apparatus (2) for the pipe (3) and the supply apparatus (4) for the at least one strand (5) are designed and arranged such that in the operation of the device (1) the strand (5) extends in the pipe (3) in material flow direction prior to the forming tool, and that the pipe (3) made of metal with the at least one strand (5) extending therein can be formed using the forming tool and

    that the supply apparatus (2) for the pipe (3) has

    a supply apparatus (8) for a strip (9) made from a metal sheet, wherein the strip (9) has a longitudinal direction and a transverse direction,

    a bending apparatus (10) for bending the strip (9) in the transverse direction, such that a pipe-shaped hollow body (13) with a cylindrical cross-sectional area results, and a welding apparatus (14) for welding-shut the pipe-shaped hollow body (13) with a longitudinal seam (19), wherein the longitudinal seam (19) extends in the longitudinal direction, such that a longitudinally-welded pipe (3) results, and

    that the supply apparatus (2) for the pipe (3) and the supply apparatus (4) for the at least one strand (5) are designed and arranged such that the strand (5) can be mounted onto the strip (9) made from the metal sheet prior to the welding apparatus (14).
13. Device (1) according to the previous claim, characterised in that the device (1) has a control apparatus (15), wherein the control apparatus (15) is connected actively to the supply apparatus (8) for the strip (9), to the supply apparatus (4) for the at least one strand (5), and to the welding apparatus (14), such that the control apparatus (15) in an operation of the device (1) controls a supply speed of the supply apparatus (8) for the strip (9), a supply speed of the supply apparatus (4) for the at least one strand (5), and a welding speed of the welding apparatus (14).

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