Method for the production of a closed hollow profile for a vehicle axle

Abstract

A method for the production of a closed hollow profile for a vehicle axle including the following steps: a) provision of a board made out of a sheet of metal, wherein the board has at least a length in a longitudinal direction and at least a width in a transverse direction, b) forming of the board, creating an open profile with a channel running in a longitudinal direction of the board, c) forming the lateral surfaces of the board, creating a hollow profile with a circumference and a longitudinal gap and d) joining together the longitudinal gap.

Claims

1. A method for the production of a closed hollow profile for a vehicle axle comprising the following steps: a) providing a board made of sheet metal, wherein the board has at least a length (L) in a longitudinal direction and at least a width (B) in a transverse direction, wherein lateral surfaces of the board extend in the transverse direction, b) forming the board, wherein an open profile having a channel extending in the longitudinal direction of the board is created, wherein the lateral surfaces remain extending in the transverse direction, c) forming the board, wherein the channel is deformed in an opposite direction from a direction in which the channel is created in step b), wherein the lateral surfaces remain extending in the transverse direction, d) forming the lateral surfaces of the board, wherein a hollow profile having a circumference (U) and having a longitudinal gap is created, and wherein the lateral surfaces of the board are formed to extend in a direction substantially perpendicular to the transverse direction after the channel is deformed in the opposite direction from the direction in which the channel is created in step b); and e) joining of the longitudinal gap, wherein the board is formed such that a compressive stress is generated at least in a region of the longitudinal gap.

2. The method according to claim 1, wherein the width (B) of the board is larger in at least one place than the circumference (U) of a same point on the hollow profile generated during the forming.

3. The method according to claim 1, wherein the board comprises a high-strength or super high-strength steel.

4. The method of claim 1, wherein the board has a thickness in the range from 0.5 mm to 4.0 mm.

5. The method of claim 1, wherein the board has an elongation at break of less than 21%.

6. The method of claim 1, wherein the board is formed by any of the following methods: deep drawing, and/or stretch forming, and/or stamping and raising.

7. The method of claim 1, wherein the board is formed such that a butt joint or a lap joint is created.

8. The method of claim 1, wherein the board is formed such that a cross section on both ends of the open profile is substantially U-formed.

9. The method of claim 1, wherein the board is formed such that a cross section in the centre of the profile which is open on one side is substantially W-formed.

10. The method of claim 1, wherein the longitudinal gap is joined by any of the following methods: welding, soldering, adhesion or a mechanical joining process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in greater detail below using a drawing which merely shows one preferred embodiment of the invention, in which:

(2) FIG. 1A shows a board made of sheet metal with a rectangular shape,

(3) FIG. 1B shows a tailored blank made of sheet metal,

(4) FIG. 1C shows a tailored blank cut near to the end contour,

(5) FIG. 2 shows a perspective view of the production of a closed hollow profile from a board by means of the method in accordance with the invention in seven steps,

(6) FIG. 3 shows a lateral view of the production of a closed hollow profile from a board by means of the method in accordance with the invention in seven steps,

(7) FIG. 4A shows a front view of a closed hollow profile produced by means of the method in accordance with the invention,

(8) FIG. 4B shows a plan view of the closed hollow profile from FIG. 4A,

(9) FIG. 4C shows a lateral view of the closed hollow profile from FIG. 4A,

(10) FIG. 5 shows a schematic view of the progression of a method in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

(11) FIG. 1 shows a board 1 made of a metal sheet which can be formed or shaped into a hollow profile in the method in accordance with the invention. The board 1 initially has a rectangular shape (rectangular board) and has a length L in the longitudinal direction and a width B in a transverse direction (FIG. 1A). After forming step b), the rectangular board is subjected to a forming cut, in particular of the edges running in a longitudinal direction. The board 1 is alternatively a tailored blank (FIG. 1B) having several lengths L transverse in a longitudinal direction and several widths B longitudinal in a transverse direction and a corresponding mould contour. The tailored blank is preferably deep drawn with a distanced hold-down clamp during forming step b), wherein a cut (final cut) is only carried out after joining. A further board 1 is alternatively shown in FIG. 1C, which as a tailored blank cut near to the end contour has several lengths L transverse in a longitudinal direction and several widths B longitudinal in a transverse direction and a corresponding mould contour.

(12) FIG. 2 shows a perspective view of the production of a closed hollow profile from a board 1 by means of the method in accordance with the invention in seven steps. FIG. 3 shows a lateral view of the production of a closed hollow profile 2 from a board 1 by means of the method in accordance with the invention in seven steps. The seven steps are designated I-VII in both FIG. 2 and FIG. 3.

(13) In step I, a flat board 1 made out of sheet metal is provided. The board 1 was cut on the longitudinal edges and corresponds to the board 1 shown in FIG. 1B. In step II the board 1 was formed in the region of the two ends 3 such that an indentation 4 was created in each case. Deep drawing and/or stretch forming is then used to form the board 1 such that an open profile with a channel 5 running in a longitudinal direction of the board 1 is created (step III). In step IV, the channel 5 was deformed in the opposite direction and then had a curved shape. The lateral surfaces 6, 7 of the board 1 running adjacent to the central channel 5 were then formed in the direction of the channel 5 (step V). The lateral surfaces 6, 7 of the board 1 were then further formed to create a hollow profile 8 with a longitudinal gap 9 (step VI). A closed hollow profile 2 is finally generated by means of the welding of the longitudinal gap (edge joint), wherein a welded seam 10 connecting the two lateral surfaces 6, 7 is created (step VII).

(14) FIG. 4A shows a front view of a closed hollow profile produced using the method in accordance with the invention, FIG. 4B shows a plan view of the closed hollow profile 2 from FIG. 4A and FIG. 4C shows a lateral view of the closed hollow profile 2 from FIG. 4A. As can be identified on the two uneven ends of the hollow profile 2 in FIG. 4A and in FIG. 4B in particular, a board 1 with cut transverse edges was used to produce the hollow profile 2. A board 1 of this type is shown by way of an example in FIG. 1C.

(15) Finally, FIG. 5 shows a schematic view of the progression of a method in accordance with the invention. The method comprises the following steps: a) provision of a board 1, b) forming of the board 1 (channel 5), c) forming of the board 1 (lateral surfaces 6, 7) and d) joining the longitudinal gap 9 (edge joint).

LIST OF REFERENCE NUMERALS

(16) 1: Board 2: Closed hollow profile 3: End (of board 1) 4: Indentation 5: Channel 6, 7: Lateral surfaces (of board 1) 8: Hollow profile 9: Longitudinal gap 10: Welded seam L: Length (of board 1) B: Width (of board 1) U: Circumference (of the hollow profile 8)