Method for producing spring strut forks

Abstract

An efficient method for producing spring strut forks for motor vehicles is presented. In each case two spring strut forks are produced from a metallic extruded profile as a starting product. The extruded profile has a central, middle main chamber and four longitudinal chambers which are arranged offset with respect to one another over the circumference of the main chamber. Wall portions of the main chamber which are situated between the longitudinal chambers are removed, and the extruded profile is severed into two semifinished parts. Each semifinished part has one cylinder portion and two oppositely situated arm portions which project relative to the cylinder portions. The semifinished parts are subsequently mechanically machined, and one spring strut fork is produced from each semifinished part.

Claims

1. Method for producing spring strut forks for motor vehicles, wherein a spring strut fork has a spring strut receptacle and fork arms and is produced from a metallic extruded profile which has a central, middle main chamber and longitudinal chambers on an outside of the extruded profile, the method comprising: providing an extruded profile having at least four longitudinal chambers which are arranged offset with respect to one another over the circumference of the main chamber; removing wall portions of the main chamber which are situated between the longitudinal chambers, and severing the extruded profile into two semifinished parts which have in each case one cylinder portion and two oppositely situated arm portions which project relative to the cylinder portion; and mechanically machining the semifinished parts to form in each case one spring strut fork.

2. Method according to claim 1, wherein two identical semifinished parts are produced from the extruded profile.

3. Method according to claim 1, wherein the longitudinal chambers are arranged offset with respect to one another by 90° +/−15° on a pitch circle.

4. Method according to claim 1, wherein, during the mechanical machining of the semifinished parts, the cylinder portions are provided with a longitudinal slot.

5. Method according to claim 4, wherein the longitudinal slot is made along a truncated longitudinal chamber.

6. Method according to claim 1, wherein, during the mechanical machining of the semifinished parts, the arm portions are bent, flattened at the ends, and provided with attachment points in the flattened end portion.

7. Method according to claim 6, wherein, during the mechanical machining of the semifinished parts, the attachment points are aligned parallel to one another.

8. Method according to claim 1, wherein the extruded profile comprises aluminum or an aluminum alloy.

9. Method according to claim 1, wherein a wall thickness of the main chamber and a wall thickness of the longitudinal chambers differ from one another.

10. Method according to claim 9, wherein the wall thickness of the main chamber is greater than the wall thickness of a longitudinal chamber.

Description

(1) The invention will be described in more detail below on the basis of drawings, in which, in each case in a perspective view:

(2) FIG. 1 shows an extruded profile as a starting product for the production of spring strut forks;

(3) FIG. 2 shows the extruded profile in an intermediate stage of the machining;

(4) FIG. 3 shows a semifinished part produced from the extruded profile, and

(5) FIG. 4 shows a spring strut fork produced in accordance with the invention.

(6) FIG. 4 shows a spring strut fork 1. The spring strut fork 1 has a spring strut receptacle 2 and two fork arms 3, 4 extending away from the spring strut receptacle 2 at one side. The fork arms 3, 4 run in arcuately curved fashion and are flattened at the ends. The flattened end portions 5, 6 are aligned parallel to one another and are provided with attachment points 7, 8. The attachment points 7, 8 are in each case bearing seats produced by means of a punched hole arrangement in the end portions 5, 6. The attachment points 7, 8 have a common axis A directed transversely with respect to the longitudinal extent of the spring strut fork 1.

(7) The spring strut fork 1 is composed of light metal, in particular of aluminum or of an aluminum alloy, and is produced from an extruded profile 9.

(8) An extruded profile 9 that is used as a starting product for the production of in each case two spring forks 1 is illustrated in FIG. 1.

(9) The extruded profile 1 has a central, middle main chamber 10. The main chamber 10 is of cylindrical configuration. On the outside, four longitudinal chambers 11, 12 are arranged offset with respect to one another over the circumference. The four longitudinal chambers 11, 12 have, in cross section, an approximately U-shaped contour with in each case two longitudinal webs 13, 14 and a rear wall 15 which connects the longitudinal webs 13, 14. The longitudinal chambers 13, 14 extend over the entire length L of the main chamber 10.

(10) The main chamber 10 of the extruded profile 9 has a wall thickness s1. Said wall thickness s1 of the main chamber 10 is greater than the wall thickness s2 of a longitudinal chamber 11 or 12. The wall thickness s1 of the main chamber 10 and the wall thickness s2 of the longitudinal chambers 11, 12 consequently differ from one another.

(11) To produce the spring strut forks 1, wall portions 17 of the main chamber 10 which are situated between the longitudinal chambers 11, 12 in a middle region 16 of the extruded profile 9 are removed along the longitudinal chambers 11, 12. Cylinder portions 20 remain at the two ends 18, 19 of the extruded profile 9. Subsequently, the extruded profile 9 is severed into two semifinished parts 21. For this purpose, in each case two opposite longitudinal chambers 11, 12 are severed directly behind or parallel to the inner edge 22 of a cylinder portion 20, on the one hand at the end 18, and at the other end 19.

(12) In this way, two identical semifinished parts 21 are created, one of which is illustrated in FIG. 3. The semifinished part 21 has the cylinder portion 20 and two arm portions 11′, 12′ which are formed from the longitudinal chambers 11, 12, are situated opposite one another and project relative to the cylinder portion 20. Of the longitudinal chambers 11, 12 that previously ran so as to be offset in each case by 90°, the truncated longitudinal chambers 11″, 12″ have remained on the cylinder portion 20.

(13) During the mechanical machining of the semifinished parts 21, the cylinder portions 20 have each been provided with a longitudinal slot 23. The longitudinal slot 23 extends through one of the truncated longitudinal chambers 11″ and severs the wall 24 of the cylinder portion 20 and the rear wall 15 of the longitudinal chamber 11.

(14) Then, a spring strut fork 1 is produced from each semifinished part 21 by mechanical machining. During the mechanical machining, the fork arms 3, 4 are produced. For this purpose, the arm portions 11′, 12′ are bent outward and are directed inward again at the ends, and the free ends 25 thereof are flattened and are provided with the attachment points 7, 8 in the flattened end portions 5, 6. In this way, the bearing seats are formed in the end portions 5, 6 of the fork arms 3, 4, as illustrated in FIG. 4. Each fork arm 3, 4 extends from the outer end side of the spring strut receptacle 2 along the cylinder portion 20 and projects relative to the cylinder portion 20.

(15) At the inner end of the cylinder portion 20 at the fork arm side, said cylinder portion has a projection 26. The projection 26 has been formed out of the cylinder portion 20 and has been deformed in an inwardly directed manner. The projection 26 forms a mechanical end stop for the damper installation. This is intended to prevent the damper tube from sliding further during the installation process until the damper tube has been firmly clamped and the damper is held by a clamping force applied to the webs 13, 14 of the longitudinal chamber 11″ provided with the longitudinal cut 23.