Combined pull rod type axle

Abstract

The invention relates to a combined pull rod type axle which is provided with two side arms (2) and a torsion profile (1). The torsion section bar (1) is connected with one side arm (2) through a welding seam (8). At least in the region of the welded connection, the torsion profile (1) comprises a wall (3) having a wall thickness (t1) which is greater than the wall thickness (t2) of the wall (4) of the side arm (2). The torsion profile (1) has a joining surface (6) on each end section (5) and the side arms (2) each have a joining surface (7), and the torsion profile (1) and the side arms (3) are connected at their joining surfaces (6, 7) opposite each other by means of a weld seam (8). The joining surface (6) on the end section (5) of the torsion profile (1) has an inclined surface (9). A joining gap (11) formed between mutually opposite joining surfaces (6, 7) of the end section (5) and the side arm (2) is configured in a V-shape. As a result, the penetration depth of the weld seam (8) on the torsion profile (1) can be significantly increased.

Description

Technical Field

[0001] The invention relates to a bundled-link axle for a motor vehicle according to the features of the preamble of claim 1 . Background Art

[0002] The combined tie-axle axle has two bending- and torsion-resistant side arms and a torsion profile extending transversely therebetween, which connects the side arms in a torsionally flexible manner. The combined tie-axle axle is characterized by good lateral guidance when cornering, as well as its favorable space requirement and low weight.

[0003] For example, DE 2735939 C2 or EP 0916530 B1 discloses a combined tie rod axle with a torsion profile having a V-shaped cross section. The torsion profile is welded to the side arm.

[0004] Due to the high dynamic and static forces acting during operation, especially the longitudinal forces, the weld between the torsion profile and the side arm is highly loaded. Therefore, the strength and quality of the weld are of particular importance. The penetration depth of the weld is closely related to the joint strength.

[0005] Typically, the torsion profile and the side arm have different wall thicknesses. Typically, the wall thickness of the torsion profile is greater than that of the side arm. When joining by butt welding according to welding technology, it has been found that, due to the difference in wall thickness between the torsion profile and the side arm, it is difficult to achieve a high penetration of the weld seam into the torsion profile without burning through the side arm. Due to the low penetration, the service life of the combined drawbar axle can be shortened. Summary of the invention

[0006] Starting from this prior art, the object of the invention is to improve the load-bearing behavior of a twist-axle and to extend the service life of a twist-axle without undesirably increasing its weight.

[0007] According to the invention, this object is achieved by a combined drawbar axle according to the features of claim 1 .

[0008] Advantageous embodiments and developments of the track axle according to the invention are the subject matter of the dependent claims.

[0009] The combined tie rod axle has two side arms and a torsion profile, which connects the two side arms in a torsionally flexible manner. The torsion profile is respectively connected to the side arms by a welded connection. The torsion profile comprises a wall with a wall thickness, and the side arms respectively comprise a wall with a wall thickness. The wall thickness of the wall of the torsion profile is greater than the wall thickness of the wall of the side arm in the area of ​​the welded connection at least in the area of ​​the welded connection. The torsion profile has a joining surface on each end section. Each side arm also has a joining surface. The torsion profile and the side arms are respectively connected by a weld seam on their mutually opposing joining surfaces.

[0010] The joining surface has a bevel on each end section of the twisted profile. The end section tapers in the direction of the end face side end of the twisted profile by the bevel. The end section of the twisted profile obtains a weld preparation coordinated with the joining according to the welding technology. The joining surface is extended by the section of the bevel and tapers toward the end of the end section. By the bevel in the joining surface of the end section, the joining gap between the joining surface on the end section of the twisted profile and the joining surface on the side arm has a V-shaped configuration. The joining gap between the end section of the twisted profile and the side arm is configured in a V-shape. By the bevel and the V-shaped joining gap, a high penetration depth can be achieved in the twisted profile. The penetration depth refers to the depth of the molten zone in the base material (here, the steel in the end section of the twisted profile).

[0011] The penetration depth is usually between 2% and 10%. The present invention also contemplates higher penetration depths. The side penetration length, i.e., the length of the molten zone where the welding filler material joins the base material, is 70% to 90% of the wall thickness of the component, especially the wall thickness of the twisted profile.

[0012] The invention provides a combined tie rod axle with a longer service life without increasing the weight of the components. The driving dynamics-advantageous properties and thus the highest degree of driving stability and comfort are maintained.

[0013] The torsion profile and the side arms are aligned at an angle transversely to one another, in particular the torsion profiles each contact a side arm in the form of a T-joint.

[0014] An advantageous design provides that the end section of the twisted profile has a butt joint on the end side, wherein the butt joint extends substantially perpendicularly to the longitudinal axis of the wall of the twisted profile. The butt joint on the end side is a component of the joint surface on the end section of the twisted profile. Via the butt joint, the twisted profile is butt-joined to the joint surface on the side arm.

[0015] The bevel extends into the end face of the end section. The abutment surface adjoins the bevel.

[0016] The butt joint surface is significantly shorter than the length of the inclined surface and extends parallel to the joint surface on the side arm.

[0017] It is particularly advantageous if the bevel is produced by machining. To produce a combined tie rod axle, a torsion profile can be provided with its conventional cross section, ie, for example, with a U-shaped, V-shaped or round cross section. The end section is then machined and the bevel is produced.

[0018] In particular, the bevel is arranged in the area of ​​the butt edge where the maximum load occurs due to external forces. In the torsion profile of the combined tie rod axle, the bevel is arranged in particular on the joint surface of the leg of the torsion profile. In the torsion profile with a U-shaped or V-shaped cross-section, the bevel is arranged on the inner side of the torsion profile along the leg on the inner side of the cross-section or on the outer side of the cross-section on the outer side of the torsion profile. The bevel is arranged on a partial section of the leg length of the torsion profile. According to the present invention, the bevel is arranged in a length section at the lower part of the leg length and extends over 30% to 75%, in particular about 50% of the leg length. The tangential length of the bevel is measured in the cross-section of the torsion profile along the circumferential direction of the torsion profile and can extend over the entire circumferential length of the end face side of the torsion profile. However, the tangential length of the bevel can also extend only over the length of the leg or be arranged on a partial section of the leg length of the torsion profile.

[0019] In regions or sections of the joining surface where no bevel is provided, the joining surface of the torsion profile adjoins the joining surface of the side arm.

[0020] In order to manufacture the inclined surface, the joint surface on the end section of the twisted profile is machined. In this case, the material of the end section is removed. This can be achieved, for example, by milling, turning or grinding.

[0021] In particular, a wedge-shaped edge region is removed at the end of each end section of the twisted profile and the bevel is produced in the joint surface.

[0022] It is also possible that the front side of the sheet steel blank is first processed and provided with a bevel, and then the blank is formed into a twisted profile and provided with its normal cross section.

[0023] The inclined surface extends at an angle relative to the longitudinal axis of the wall of the twisted profile, preferably in the range of 25° to 60°. For practical applications, it is particularly advantageous if the angle is in the range of 30° to 45°.

[0024] The inclined surface has an axial length, wherein the axial length is greater than the wall thickness of the wall of the twisted profile in the end section. In particular, the ratio of the axial length of the inclined surface to the wall thickness of the wall of the twisted profile is dimensioned to be between 1:1 and 2:1. The axial length of the inclined surface is measured in the direction of the longitudinal axis of the wall of the twisted profile.

[0025] The abutment surface on the end face side of the end section of the end profile has a width, wherein the width is measured perpendicularly to the longitudinal axis of the wall of the twisted profile. The width of the abutment surface is significantly smaller than the wall thickness of the wall of the twisted profile, in particular the wall thickness of the wall of the twisted profile is 3 to 6 times the width of the abutment surface. Therefore, the ratio of the width of the abutment surface to the wall thickness of the wall of the twisted profile in the end section is dimensioned to be between 1:3 and 1:6.

[0026] To produce the combined tie-axle, two side arms and a torsion profile are provided. The components of the combined tie-axle are made of steel. The torsion profile and the side arms have different wall thicknesses at least in the area of ​​the connection according to welding technology. In particular, the wall thickness of the torsion profile is greater than the wall thickness of the side arms. The torsion profile and the side arms are arranged at an angle to one another and are connected by a weld seam.

[0027] In order to produce the twisted profile, a starting plate blank having a wall with a wall thickness is provided. A chamfer is formed on the end section of the starting plate blank and a butt surface is formed on the end section on the end face side.

[0028] The initial sheet is formed into a twisted profile. In this forming step, the initial sheet at least partially acquires the cross-sectional configuration of a twisted profile, in particular over its length. In this case, the initial sheet is formed in particular around its longitudinal axis and is provided with the cross section of a twisted profile, i.e., is formed, for example, U-shaped or V-shaped in cross section.

[0029] Furthermore, the two side arms are provided. The side arms comprise a wall having a wall thickness which is different from the wall thickness of the twisted profile.

[0030] The twisted profile and the side arm are aligned at an angle relative to each other so that the joint surface of the twisted profile and the joint surface of the side arm face each other. Then, the twisted profile and the side arm are joined in a material-locking manner by a weld seam on the joint surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is described in detail below by means of the accompanying drawings. In the accompanying drawings:

[0032] Figure 1 A technically schematic and simplified illustration of a section of a wall including a twisted profile and a section of a wall including a side arm before joining using a welding technique;

[0033] Figure 2 Shown after joining with welding technology Figure 1 The component corresponding to the diagram;

[0034] Figure 3 A combined tie rod axle is shown in perspective;

[0035] Figure 4A view showing an end-face side of an end section of a twisted profile; and

[0036] Figure 5 A view of the end face of an end section of another embodiment of a twisted profile is shown. DETAILED DESCRIPTION

[0037] Figure 1 and Figure 2 A detail of the components of a combined tie rod axle for a motor vehicle is shown. A combined tie rod axle V is shown in a perspective view. Figure 3 The combined tie rod axle V essentially comprises two side arms 2 guiding the wheels and a torsion profile 1 connecting the two side arms 2. The torsion profile is exemplarily indicated by reference numeral 1, and the side arms are indicated by reference numeral 2.

[0038] The twisted profile 1 comprises a wall 3 with a wall thickness t1. The side arms 2 each comprise a wall 4 with a wall thickness t2. The wall thickness t1 of the wall 3 of the twisted profile 1 is greater than the wall thickness t2 of the wall 4 of the side arms 2.

[0039] The twisted profile 1 has a joint surface 6 on each end section 5. The side arms 2 also have joint surfaces 7. The twisted profile 1 and the side arms 2 are connected by weld seams 8 on their mutually opposite joint surfaces 6, 7. The welded connection structure with the weld seams 8 is Figure 2 Shown in.

[0040] The joining surface 6 on the end section 5 of the twisted profile 1 has a chamfer 9. The chamfer 9 is produced by machining the end section 5. The end section 5 tapers in the direction of the end face 10 of the twisted profile 1 by means of the chamfer 9.

[0041] In order to produce the welded connection, the torsion profile 1 and the side arm 2 are positioned relative to each other. Figure 1 The joint surfaces 6 and 7 are opposite to each other. A V-shaped joint gap 11 is formed between the joint surface 5 of the twisted profile 1 and the joint surface 6 of the side arm 2. The material-locked connection is achieved by a weld seam, such as Figure 2 As shown. The bevel 9 makes the weld seam 8 significantly more efficient and, in particular, a component-optimized penetration can be achieved in the twisted profile 1 .

[0042] The end section 5 of the twisted profile 1 has a butt surface 12 on the end face side. The butt surface 12 extends substantially perpendicularly to the longitudinal axis L of the wall 3 of the twisted profile 1. The butt surface 12 is oriented parallel to the joint surface 6 of the side arm 2. A gap section formed parallel to the butt surface 12 and the joint surface 6 adjoins the deepest part of the V-shaped joint gap 11.

[0043] The end section 5 tapers at an acute angle α to the end face 10 via the bevel 9. The bevel 9 ends at the end face 10. The abutment surface 12 adjoins the bevel 9 at an obtuse angle.

[0044] The inclined surface 9 extends at an angle α relative to the longitudinal axis L of the wall 3 of the twisted profile 1. In the exemplary embodiment shown, the angle α is approximately 30°.

[0045] The inclined surface has an axial length l. The axial length l is greater than the wall thickness t1 of the wall 3 of the twisted profile 1. The ratio of the axial length l of the inclined surface 9 to the wall thickness t1 of the wall 3 of the twisted profile 1 can be dimensioned between 1:1 and 2:1.

[0046] Compared to the wall thickness t1 of the wall 3 of the twisted profile 1, the abutment surface 12 has a significantly smaller width b. The width b of the abutment surface 12 is measured perpendicularly to the longitudinal axis L of the wall 3 of the twisted profile 1. The ratio of the width b of the abutment surface 12 to the wall thickness t1 of the wall 3 of the twisted profile 1 can be dimensioned between 1:3 and 1:6. In a particularly advantageous practical embodiment of the combined tie rod axle according to the invention, the width b of the abutment surface 12 is 1 mm to 3 mm, respectively inclusive.

[0047] By means of the weld preparation and the formation of the bevel 9 in the joint surface 6 on the end section 5 of the twisted profile 1 and the V-shaped configuration of the joint gap 11, a welded connection of satisfactory quality is produced between the twisted profile 1 and the side arm 2. The penetration depth of the weld seam 8 on the twisted profile 1 can be significantly increased without burn-through on the side arm 2. The weld seam 8 meets the highest strength requirements, as a result of which the service life of the combined tie rod axle can be increased without a disadvantageous increase in weight.

[0048] Figure 3 A combined tie rod axle V is shown. The torsion profile 1 is connected to the side arms 2 in each case in a T-joint. The torsion profile 1 has a wall 3 (see Figure 1 and Figure 2 ), and has a U-shaped cross-sectional profile with two side legs 13 connected by a vertex section 14. The twisted profile 1 contacts the wall 4 of the side arm 2 via the end section 5. The joining surface 6 on the end section 5 of the twisted profile 1 is adapted to the outer contour of the side arm 2 and extends in an arc-shaped manner.

[0049] Arrow P1 schematically shows the tangential length of the side leg 13, with which the end section 5 of the twisted profile 1 contacts the outer circumference of the side arm 2. This is approximately 180°+ / −15° relative to the circumference of the side arm 2, which is circular in cross section.

[0050] The length of the length section 15 in which the bevel 9 is arranged on the inner side of the side leg 13 of the twisted profile 1 is indicated by the arrow P2. The bevel 9 is arranged in the lower length section 15 of the side leg 13. The bevel 9 extends over 30% to 75% of the length of the side leg 13, in particular approximately half of the length. The bevel 9 extends over a circumferential section of approximately 90°+ / -15° relative to the cross section of the side arm 2. The bevel 9 is arranged in the lower length section 15 of the side leg 13 starting from the free leg end.

[0051] Figure 4 The front view shows a joint surface 6 on the end section 5 of the twisted profile 1. The twisted profile 1 comprises a wall 3 with a wall thickness t1. An inclined surface 9 is provided in the joint surface 6 on the end section 5 of the twisted profile 1. The inclined surface 9 extends inside the lateral leg 13 of the twisted profile 1.

[0052] The bevel 9 is arranged in a lower length section 15 of the side leg 13 starting from the free leg end. The tangential length of the length section 15 is indicated by the arrow P2. In the embodiment shown, the bevel 9 extends approximately over half the length of the side leg 13.

[0053] Figure 5 A front view of an alternative design of the joining surface 6 at the end section 5 of the twisted profile 1 is shown. Figure 4 Unlike the embodiment of the present invention, the bevel 9 is arranged on the outside of the side legs 13 of the twisted profile. The bevel 9 is produced by cutting as in the other embodiments. The bevel 9 extends in the lower length section 15 of each side leg 13 starting from the free leg end. In other respects, this embodiment is different from the Figure 4 And corresponding to the implementation methods described in the related description.

[0054] Reference numerals list

[0055] 1Twisted profile

[0056] 2 side arms

[0057] 3. Twisting the wall of the profile

[0058] 4 side arm wall

[0059] 5 End section

[0060] 6Joint surface

[0061] 7Joint surface

[0062] 8. Welding Seams

[0063] 9 bevel

[0064] 10 End side

[0065] 11Joint gap

[0066] 12 docking surface

[0067] 13 side legs

[0068] 14 Vertex Segment

[0069] Length segment of 1513

[0070] bWidth

[0071] L longitudinal axis

[0072] Length

[0073] Wall thickness of t13

[0074] Wall thickness of t24

[0075] α angle

[0076] P1 Arrow

[0077] P2 Arrow

Claims

1. A combined tie-rod axle, comprising two side arms (2) and a torsion profile (1), wherein the torsion profile (1) comprises a wall (3) having a wall thickness (t1), and the side arms (2) each comprise a wall (4) having a wall thickness (t2), the wall thickness (t1) of the wall (3) of the torsion profile (1) being greater than the wall thickness (t2) of the wall (4) of the side arms (2), and the torsion profile (1) having a joint surface (6) on each end section (5), and the side arms (2) each having a joint surface (7), the torsion profile (1) and the side arms (2) being connected at their mutually opposite joint surfaces (6, 7) by welds (8), characterized in that: The twisted profile (1) has two side legs (13) connected by a vertex section (14), and the joining surface (6) on the end section (5) of the twisted profile (1) has a bevel (9), which is arranged in a lower length section (15) of the side legs (13) and extends over 30% to 75% of the length of the side legs (13).

2. The combined tie rod axle according to claim 1, characterized in that: The end section (5) of the twisted profile (1) has a contact surface (12) on the end side, which extends essentially perpendicularly to the longitudinal axis (L) of the wall (3) of the twisted profile (1).

3. The combined tie rod type axle according to claim 2, characterized in that: The abutment surface (12) is connected to the inclined surface (9).

4. The combined tie rod axle according to any one of claims 1 to 3, characterized in that: The bevel (9) is produced by cutting.

5. The combined tie rod axle according to any one of claims 1 to 4, characterized in that: The bevel (9) extends at an angle (α) of 25° to 60°, in particular 30° to 45°, relative to the longitudinal axis (L) of the wall (3) of the twisted profile (1).

6. The combined tie rod axle according to any one of claims 1 to 5, characterized in that: The inclined surface (9) has an axial length (l), and the ratio of the axial length (l) of the inclined surface (9) to the wall thickness (t1) of the wall (3) of the twisted profile (1) is dimensioned to be between 1:1 and 2:

1.

7. The combined tie rod axle according to any one of claims 2 to 6, characterized in that: The abutment surface (12) has a width (b) measured perpendicularly to the longitudinal axis (L) of the wall (3) of the twisted profile (1), and the ratio of the width (b) of the abutment surface (12) to the wall thickness (t1) of the wall (3) of the twisted profile (1) is dimensioned to be between 1:3 and 1:

6.

8. The combined tie rod axle according to any one of claims 1 to 7, characterized in that: The inclined surface (9) is arranged in a length section (15) starting from the free leg end of the leg (13) of the torsion profile (1).

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