METHOD AND DEVICE FOR PRODUCING A ROD-SHAPED ELEMENT

Abstract

The present disclosure relates to a method for producing a rod-shaped element. In order to provide a method with which it is possible to produce a rod-shaped element which overcomes at least one of the disadvantages of the rod-shaped elements known from the state of the art, it is proposed according to the invention that the method has the steps of providing a tube made of a metal, wherein the tube has a longitudinal direction, providing at least one strand with a plurality of threads, wherein at least one of the threads has carbon fibres, introducing the at least one strand into the tube, with the result that the at least one strand extends in the longitudinal direction in the tube, and cold forming the tube, together with the at least one strand, using a forming tool, with the result that an outside diameter of the tube before the cold forming is larger than the outside diameter of the tube after the cold forming.

Claims

1. A method for producing a rod-shaped element, wherein the method has the steps of: providing a tube made of a metal, wherein the tube has an outside diameter and a longitudinal direction, providing at least one strand with a plurality of threads, wherein at least one of the threads has carbon fibres, introducing the at least one strand into the tube, with the result 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, with the result that the outside diameter of the tube before the cold forming is larger than the outside diameter of the tube after the cold forming.

2. The method according to claim 1, wherein the provision of the tube comprises the steps of: providing a strip of a metal sheet, wherein the strip has a longitudinal direction and a transverse direction, bending the strip in the transverse direction, with the result that a tubular hollow body with the cross-sectional area of a cylinder is formed, and welding closed the tubular hollow body with a longitudinal seam, wherein the longitudinal seam extends in the longitudinal direction, with the result that a longitudinally welded tube is formed, wherein the introduction of the at least one strand into the tube is effected by applying the strand to the strip before the welding closed.

3. The method according to claim 2, characterized in that wherein the bending of the strip in the transverse direction comprises the steps of: prebending the strip in the transverse direction, with the result that a trough-shaped hollow body with an opening extending in the longitudinal direction is formed, and finish bending the strip in the transverse direction, with the result that a tubular hollow body with the cross-sectional area of a cylinder is formed, wherein the introduction of the at least one strand into the tube is effected before the finish bending of the strip and through the opening into the trough-shaped hollow body.

4. The method according to claim 1, wherein the introduction of the at least one strand into the tube and the cold forming of the tube with the at least one strand are effected in one production line.

5. The method according to claim 2, wherein the welding closed and the cold forming are effected at a distance in a range of from 2 m to 4 m.

6. The method according to claim 1, wherein the tube consists of a stainless steel.

7. The method according to claim 1, wherein the at least one strand is selected from a cord, a woven fabric, a mesh, a knitted fabric and a multiaxial fabric or any combination thereof.

8. The method according to claim 1, wherein the at least one strand contains at least 50% carbon fibres.

9. The method according to claim 1, wherein the cold forming is effected by cold drawing of the tube, together with the at least one strand, in the longitudinal direction through a drawing die, and wherein an inside diameter of the drawing die and an outside diameter of the tube before the cold drawing are chosen such that the tube and the at least one strand are connected in a friction-locking manner after the cold drawing.

10. The method according to claim 9, wherein an inside diameter of the drawing die and an outside diameter of the tube before the cold drawing are chosen such that a wall thickness of the tube is smaller before the cold drawing than after the cold drawing.

11. A rod-shaped element obtainable by the method according to claim 1.

12. A rod-shaped element, comprising: a tube made of a metal, wherein the tube has a longitudinal direction, and at least one strand extending in the longitudinal direction in the tube, wherein the at least one strand has a plurality of threads with carbon fibres, and wherein the tube and the at least one strand are connected in a friction-locking manner.

13. A device for producing a rod-shaped element, comprising: a feed apparatus for a tube made of metal, a feed apparatus for at least one strand with a plurality of threads, and a forming apparatus, wherein the forming apparatus has a forming tool, and wherein the feed apparatus for the tube and the feed apparatus for the at least one strand are designed and arranged such that, when the device is in operation, the strand extends in the tube upstream of the forming tool in the material flow direction, and that the tube made of metal with the at least one strand extending therein can be formed using the forming tool.

14. The device according to claim 13, wherein the feed apparatus for the tube includes: a feed apparatus for a strip of a metal sheet, wherein the strip has a longitudinal direction and a transverse direction, a bending apparatus for bending the strip in the transverse direction, with the result that a tubular hollow body with the cross-sectional area of a cylinder is formed, and a welding apparatus for welding closed the tubular hollow body with a longitudinal seam, wherein the longitudinal seam extends in the longitudinal direction, with the result that a longitudinally welded tube is formed, wherein the feed apparatus for the tube and the feed apparatus for the at least one strand are designed and arranged such that the strand can be applied to the strip of the metal sheet upstream of the welding apparatus.

15. The device according to claim 14, wherein the device has a control apparatus, and wherein the control apparatus is operatively connected to the feed apparatus for the strip, to the feed apparatus for the at least one strand and to the welding apparatus such that the control apparatus, when the device is in operation, controls a feeding speed of the feed apparatus for the strip, a feeding speed of the feed apparatus for the at least one strand and a welding speed of the welding apparatus.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0091] Further advantages, features and possible applications of the present disclosure will become clear with the aid of the following description of an embodiment and the associated figures. The above general description and the following detailed description of an implementation of the present disclosure can be better understood if they are considered in conjunction with the attached drawings. The implementations shown are not limited to the designs described in detail. In the figures similar elements are denoted by identical reference numbers.

[0092] FIG. 1 is a flow diagram 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.

[0093] FIG. 2 is a flow diagram of a further implementation of the method according to the present disclosure for producing a rod-shaped element according to another implementation of the present disclosure.

[0094] FIG. 3 is a schematic top view of an implementation of the device for producing a rod-shaped element for carrying out the method from FIG. 2.

[0095] FIG. 4 is a schematic cross-sectional view of an implementation of the rod-shaped element, which it has been obtained with the method from FIG. 2 or the device from FIG. 3.

DETAILED DESCRIPTION

[0096] FIG. 1 is a flow diagram of an implementation of the method for producing a rod-shaped element according to the present disclosure. In a first step 100 a stainless steel tube is provided, wherein the stainless steel tube has a longitudinal direction. In a further step 101, at the same time as the first step 100, a mesh is provided which is formed of a plurality of threads made of carbon fibres. In the implementation shown, 100% of the thus-formed strand consists of carbon fibres.

[0097] In the implementation shown, the stainless steel tube is a seamless tube, i.e. without a weld seam in the longitudinal direction, and the strand is pushed into the stainless steel tube axially in a further step 102, with the result that the strand extends in the longitudinal direction in the tube. After the introduction 102 of the strand into the stainless steel tube, the tube with the strand extending in the longitudinal direction in the tube is cold formed using a forming tool in step 103. In the implementation shown, the cold forming is carried out by cold rolling in a cold pilger rolling mill. After the cold pilger rolling 103, the stainless steel tube and the strand are connected to each other in a friction-locking manner over the entire extent of the strand in the longitudinal direction of the tube.

[0098] FIG. 2 shows a flow diagram of a further implementation of the method for producing a rod-shaped element. Here, the individual steps of the method according to this implementation take place in one production line, wherein a strip of stainless steel sheet and the strand are fed to the production line as starting materials.

[0099] In the case of the method described with reference to FIG. 2, the step of providing 100 the stainless steel tube thus also comprises the actual manufacture of the stainless steel tube. For this, the provision 100 of the tube first comprises, in step 104, providing a strip of a stainless steel sheet. The strip has a longitudinal direction and a transverse direction. In step 105, the strip is bent in the transverse direction to give the tube.

[0100] To bend the tube, the strip is first prebent in step 107, with the result that a trough-shaped hollow body with an opening extending in the longitudinal direction is formed. At the same time, in step 101, a strand with a plurality of threads with carbon fibres is provided. In the implementation shown, the strand consists of a mesh containing 60% carbon fibres. After the prebending 107 of the stainless steel sheet, the strand is introduced into the trough-shaped hollow body in the longitudinal direction in step 102. Through the trough shape, the strand is guided on the stainless steel sheet, with the result that the strand cannot slide off the stainless steel sheet. Once the strand has been introduced into the trough, the stainless steel sheet is finish bent in the transverse direction in step 108, with the result that a tubular hollow body with the cross-sectional area of a cylinder is formed, which wraps around the strand. In step 106, the tubular hollow body, which consists of the stainless steel sheet, is welded closed with a longitudinal seam to form a longitudinally welded stainless steel tube. This ends step 100 of providing the tube.

[0101] After being welded closed 106, the tube is cold formed in step 103. In the implementation of the method according to FIG. 2, the cold forming is effected by cold drawing. For this, the tube is drawn, together with the strand, in the longitudinal direction through a drawing die as forming tool. After the cold drawing 103, the stainless steel tube and the strand are connected to each other in a friction-locking manner over the entire extent of the strand in the longitudinal direction of the tube.

[0102] FIG. 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 has been described above with reference to FIG. 2.

[0103] In addition to this, FIG. 4 shows a cross-sectional view in a section plane perpendicular to the longitudinal direction of the rod-shaped element 20, which has been produced with the device 1 from FIG. 3.

[0104] The device 1 has a feed apparatus 2 for the stainless steel tube 3, wherein the feed apparatus 2 is made up of a plurality of apparatuses.

[0105] The feed apparatus 2 for the stainless steel tube 3 first of all comprises a feed apparatus 8 for the strip 9 of stainless steel sheet. The strip 9 has a longitudinal direction and a transverse direction, wherein the extension is much greater in the longitudinal direction than in the transverse direction.

[0106] In addition, the feed apparatus 2 for the stainless steel tube 3 has a bending apparatus 10 for bending the strip 9. The bending apparatus 10 consists of a prebending apparatus 11 and a finish-bending apparatus 12. The strip 9 is first prebent with the prebending apparatus 11, with the result that the trough-shaped hollow body 16 is formed. The strand 5 is introduced into this trough-shaped hollow body 16 into the trough-shaped hollow body with a feed apparatus 4. Through the trough of the trough-shaped hollow body 16, the strand 5 is placed and guided centrally on the strip 9, with the result that the strand 5 cannot slide off the strip 9.

[0107] After the strand 5 has been applied to the sheet metal strip 16, the trough-shaped hollow body 16 is bent with the finish-bending apparatus 12 to give a tubular hollow body 13 with a circular cross section, wherein the strand 5 extends inside the tubular hollow body 13 in the longitudinal direction. The tubular hollow body 13 is then welded with a longitudinal seam 19 with a welding apparatus 14, which is likewise part of the feed apparatus 2 for the tube 3, with the result that the longitudinal seam 19 extends in the longitudinal direction and a longitudinally welded stainless steel tube 3 is formed.

[0108] The drawing die 7 of a draw bench 6 is provided at a distance d of 3 m downstream of the welding apparatus 14. To carry out the drawing process, the draw bench 6 has, in addition to the drawing die 7, a motor-driven carriage 17 with a clamping cylinder 18 installed on it for gripping the tube 3 downstream of the drawing die 7.

[0109] By drawing the tube 3, together with the strand 5 arranged therein, through the drawing die 7 the rod-shaped element 20 is formed. The inside diameter of the drawing die 7 and the outside diameter of the stainless steel tube 3 before the drawing are chosen such that, after the cold drawing, the stainless steel tube has a wall thickness w as represented in FIG. 4. Whereas the outside diameter of the tube is reduced after the cold drawing, the wall thickness w is larger after the cold drawing than before the cold drawing. Through the cold drawing, the tube 3 and the strand 5 are connected to each other in a friction-locking manner over the entire extent of the strand 5 in the longitudinal direction in the tube 3 downstream of the drawing die 7. The strand 5 cannot slip out of place inside the tube 3 in the axial direction. A rod-shaped element 20 with a tensile strength exceeding the tensile strength of the cold-drawn tube has been formed.

[0110] A central control apparatus 15 is electrically connected to the feed apparatus 8 for the sheet metal strip 9, to the feed apparatus 4 for the strand 5. to the welding apparatus 14 and to the draw bench 6. During operation of the line 1, the control apparatus 15 controls the feeding speeds of the strip 9, of the strand 5, as well as the welding speed of the welding apparatus 14 and the drawing speed of the draw bench 6. By controlling the above-named speeds the tube 3 and the strand 5 are connected to each other in a friction-locking manner uniformly over the entire extent of the strand 5 in the longitudinal direction in the tube 3 downstream of the drawing die 7.

[0111] For the purpose of original disclosure, it is pointed out that all features, as revealed to a person skilled in the art from the present description and the drawing, as well as the claims, even if they have been described specifically only in connection with particular further features, can be combined both individually and in any desired combinations with others of the features or groups of features disclosed here, unless this has been explicitly ruled out or technical circumstances make such combinations impossible or meaningless. Merely for the sake of brevity and readability of the description, the comprehensive, explicit representation of all conceivable combinations of features is dispensed with here.

[0112] While the disclosure has been represented and described in detail in the drawings and the preceding description, this representation and description is effected merely by way of example and is not intended to limit the scope of protection, as defined by the claims. The disclosure is not limited to the disclosed embodiments.

[0113] Modifications of the disclosed embodiments are obvious to a person skilled in the art from the drawings, the description and the attached claims. In the claims the word “have” does not rule out other elements or steps, and the indefinite article “a” or “an” does not rule out a plurality. The mere fact that particular features are claimed in different claims does not rule out combining them. Reference numbers in the claims are not intended to limit the scope of protection.

LIST OF REFERENCE NUMBERS

[0114] 1 device for producing a rod-shaped element [0115] 2 feed apparatus for a stainless steel tube [0116] 3 stainless steel tube [0117] 4 feed apparatus for a strand [0118] 5 strand [0119] 6 draw bench [0120] 7 drawing die [0121] 8 feed apparatus for a strip [0122] 9 strip [0123] 10 bending apparatus [0124] 11 prebending apparatus [0125] 12 finish-bending apparatus [0126] 13 tubular hollow body [0127] 14 welding apparatus [0128] 15 control apparatus [0129] 16 trough-shaped hollow body [0130] 17 carriage [0131] 18 clamping cylinder [0132] 19 longitudinal seam [0133] 20 rod-shaped element [0134] d distance [0135] w wall thickness [0136] 100 providing a tube [0137] 101 providing a strand [0138] 102 introducing a strand [0139] 103 cold forming [0140] 104 providing a strip [0141] 105 bending a strip [0142] 106 welding closed [0143] 107 prebending a strip [0144] 108 finish bending a strip