Combined pull rod type axle

Abstract

The invention relates to a combined pull rod type axle which is provided with two side arms (11) and a torsion profile (1). The torsion profile (1) is connected to each side arm (11) by means of a weld seam (18). At least in the region of the welded connection, the torsion profile (1) comprises a wall (4) having a wall thickness (t1) which is greater than the wall thickness (t2) of the wall (12) of the side arm (11). The torsion profile (1) has a joining surface (13) on each end section (5) and the side arms (11) each have a joining surface (14), and the torsion profile (1) and the side arms (11) are connected at their joining surfaces (13, 14) opposite each other by means of a weld seam (18). The joining surface (13) on the end section (5) of the torsion profile (1) has an inclined surface (9) which is produced without cutting. A joining gap (15) formed between mutually opposite joining surfaces (13, 14) of the end section (5) and the side arm (11) is configured in a V-shape. As a result, the penetration depth of the weld seam (18) 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 arms.

[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. Summary of the invention

[0005] Starting from the prior art, the object of the present invention is to improve the load characteristics of a twist-joint axle and to extend the service life of the twist-joint axle without undesirably increasing its weight.

[0006] According to the invention, this object is achieved by a combined tie-rod axle according to the features of claim 1 .

[0007] Advantageous embodiments and developments of the track axle according to the invention are the subject matter of the dependent claims.

[0008] The combined tie rod axle has two side arms and a torsion profile that connects the two side arms in a torsionally flexible manner. The torsion profile is connected to each side arm by a welding connection. The torsion profile includes a wall with a wall thickness, and each side arm includes a wall with a wall thickness. The torsion profile has a joint surface on each end section. Each side arm also has a joint surface. The torsion profile and the side arms are connected by welds on their mutually opposite joint surfaces. The torsion profile is assembled with each side arm at an angle of 90°. The butt surfaces on the end sections of the torsion profile are welded to the surfaces of the side arms to form a "T" shape. In this way, a T-joint is formed between the torsion profile and each side arm.

[0009] The joint surface has a chamfer produced without cutting on the 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 chamfer. The end section of the twisted profile obtains a weld preparation coordinated with the joint according to the welding technology. The joint surface is extended by the section of the chamfer and tapers toward the end of the end section. By the chamfer in the joint surface of the end section, the joint gap between the joint surface on the end section of the twisted profile and the joint surface on the side arm has a V-shaped configuration. The joint gap between the end section of the twisted profile and the side arm is configured in a V-shape. By the chamfer and the V-shaped joint 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). A component-optimized and method-technically improved penetration depth is generated in the twisted profile.

[0010] The penetration depth is usually between 2% and 10%. The invention also foresees higher penetration depths. The side penetration length, i.e. the length of the molten zone in which the welding filler material joins the base material, is 70% to 90% of the wall thickness of the component, in particular the wall thickness of the torsion profile. In particular, the invention enables a process-reliable realization of a penetration depth of up to 30%. Practical tests foresee even higher penetration values, whereby the penetration depth can be increased up to more than 50%.

[0011] By means of the chamfer provided according to the invention, welding filler material can be pushed into the joint gap between the components during welding, so that the weld root is moved further or deeper into the joint gap. As a result, a significantly higher penetration depth is achieved.

[0012] The invention provides a combined tie rod axle with a longer service life without increasing the weight of the components. The welded joint between the torsion profile and the two side arms is highly stable and has optimized static and especially dynamic load characteristics. The driving dynamics-advantageous properties and thus the highest degree of driving stability and comfort are maintained.

[0013] The twist profile and the side arm usually have different wall thicknesses. Usually, the twist profile has a wall thickness that is greater than the wall thickness of the side arm. Due to the difference in wall thickness between the twist profile and the side arm, it is difficult to achieve a high penetration of the weld into the twist profile without causing burn-through on the side arm when joining them by conventional butt welding. Due to the lower penetration, the service life of the combined tie rod axle may be shortened. The present invention provides a remedy for this.

[0014] In a particularly advantageous embodiment of the combined tie rod axle according to the invention, the torsion profile has a greater wall thickness than the side arm. At least in the region of the welded connection, the wall thickness of the torsion profile is greater than the wall thickness of the side arm in the region of the welded connection.

[0015] It is also possible that the wall thickness of the twisted profile is smaller than the wall thickness of the side arm. The wall thickness of the twisted profile can be smaller than the wall thickness of the side arm overall. However, the wall thicknesses can also differ from each other only in the region of the welded connection between the twisted profile and the side arm.

[0016] Due to the inventive bevel and the V-shaped joining gap, a high penetration depth is achieved in the first component (ie the component with the thicker or stronger wall) without causing burn-through in the thinner wall of the side arm.

[0017] The bevel can extend along the entire joint surface of the torsion profile. In particular, the bevel is provided in the region of the abutment edge where the greatest loads occur due to external forces. In the case of a torsion profile of a combined tie-rod axle, the bevel is provided in particular on the joint surface of the legs of the torsion profile. In the case of a torsion profile with a U-shaped or V-shaped cross section, the bevel is arranged along the legs on the inside or outside of the cross section, on the outside of the torsion profile of the cross section, on the inside of the torsion profile.

[0018] The inclined surface may also be arranged only on a partial section of the length of the joint surface on the end section of the twisted profile. In particular, the inclined surface is constructed starting from the free end of the wall of the twisted profile on a length section of about 30% to 75%, in particular on a length section of about 50%. The tangential length of the inclined surface is measured in the cross section of the twisted profile along the circumferential direction of the twisted profile and may extend over the entire circumferential length of the end face side of the twisted profile. However, the tangential length of the inclined surface may also extend only over the length of the leg of the twisted profile or be arranged only on a partial section of the length of the leg of the twisted profile.

[0019] The design according to the invention of the joint surface on the end section of the twisted profile with the chamfer produced without cutting makes it possible to achieve a V-shaped arrangement. The chamfer produced without cutting and the V-shaped joint gap make it possible to achieve an optimized high penetration depth. The quality of the welded connection is significantly improved.

[0020] The twist profile and the side arms are aligned transversely at an angle relative to one another, in particular the twist profiles are connected to each side arm in a T-joint.

[0021] 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.

[0022] The inclined surface is a component of the joint surface on the end section of the twisted profile. The inclined surface extends into the end face of the end section. The butt surface adjoins the inclined surface.

[0023] The length of the butt joint surface is greater than the length of the inclined surface. The butt joint surface extends parallel to the joint surface on the side arm.

[0024] Each side arm has a tubular cross section at least in the middle length section and is designed as a hollow profile or is formed by a hollow profile. In the joining area with the torsion profile, each trailing arm has a joining surface that is coordinated with the end-side abutment surface of the torsion profile. The joining surfaces of the torsion profile and the side arm are designed to be consistent with each other.

[0025] The invention provides that the abutment surface has a width, measured perpendicularly to the longitudinal axis of the wall of the twisted profile, which is greater than the wall thickness of the wall of the side arm.

[0026] 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°. An angle in the range of 30° to 45° is particularly advantageous. For practical applications, an angle of about 45° is particularly advantageous.

[0027] The inclined surface has an axial length, wherein the axial length is equal to or less 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 1:1.5. The axial length of the inclined surface is measured in the direction of the longitudinal axis of the wall of the twisted profile.

[0028] The abutment surface on the end face side of the end section of the end profile has a width, which is measured perpendicularly to the longitudinal axis of the wall of the twisted profile. The width of the abutment surface is greater than the wall thickness of the wall of the twisted profile. In particular, the width of the abutment surface is 10% to 50% greater than the wall thickness of the wall of the twisted profile. Therefore, the ratio of the wall thickness of the wall of the twisted profile to the width of the abutment surface is dimensioned to be between 1:1.1 and 1:1.5.

[0029] According to the invention, the bevel is produced without cutting in the joint surface on the end section of the twisted profile. Here, a controlled plastic deformation is performed on the end section of the twisted profile. The end section is formed into the desired shape by applying external forces. This is achieved in particular by bending or shearing.

[0030] 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.

[0031] To produce the twisted profile, a starting plate with a wall having a wall thickness is provided. The end sections of the starting plate are shaped and bevels are formed on the end sections, and then the end sections are cut on the end side and a butt surface is formed on the end face side.

[0032] Initial slab is shaped as twisted profile. In this case, initial slab is particularly shaped around its longitudinal axis and is provided with the cross section of twisted profile, i.e. for example, is shaped as U-shaped or V-shaped in the cross section.

[0033] 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.

[0034] 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.

[0035] In particular, the end sections of the twisted profile or of the initial sheet metal blank forming the twisted profile are displaced, bent or pressed laterally.

[0036] In order to produce the bevel on the end section, the end section of the initial slab can first be formed into an S-shape. The end section is then cut and the end piece at the free end of the end section is disconnected from it. The cutting is carried out perpendicular to the longitudinal axis of the initial slab or the wall of the initial slab. During the cutting process, a slight chamfer is generated, in particular on the side of the cutting tool facing the support. Therefore, the cutting line does not extend in a straight line, but has a slightly inclined chamfer or surface at the end of the cutting line.

[0037] Before or after the end sections are shaped and cut, the initial sheet can undergo further shaping. In this shaping step, the initial sheet acquires the cross-sectional configuration of a twisted profile at least partially, especially over its length. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention is described in detail below by means of the accompanying drawings. In the accompanying drawings:

[0039] Figure 1a ) to 1d) technically and schematically illustrate a method for manufacturing a twisted profile having a joint surface, wherein the joint surface comprises an inclined surface and a butt surface;

[0040] Figure 2a ) shows a portion of a wall including a twisted profile and a portion of a wall including a side arm before joining according to a welding technique;

[0041] Figure 2b ) shows the connection after welding. Figure 2a ) corresponding to the diagram;

[0042] Figure 3 A combined tie rod axle is shown in perspective;

[0043] Figure 4 A view showing an end-face view of an end section of a torsion profile of a combined tie-rod axle; and

[0044] Figure 5 A view of the end face of an end section of another embodiment of a twisted profile is shown. DETAILED DESCRIPTION

[0045] according to Figure 1a ) to 1d) explain the forming process of the torsion profile 1 for producing a twist-rod axle 2. Figure 2b ) shows a portion of the combined tie-rod axle 2.

[0046] Figure 1a ) shows an initial slab 3. The initial slab 3 comprises a wall 4 having a wall thickness t1.

[0047] The end section 5 of the initial blank 3 is formed without cutting. In this case, the end section 5 is plastically deformed and configured in an S-shape. In this way, a leg 6 with a bevel 7 and an end piece 8 extending parallel to the longitudinal axis L of the wall 4 of the initial blank 3 are formed on the end section 5. This Figure 1b ) is shown in the view of FIG. The end piece 8 is laterally displaced parallel to the longitudinal axis L of the wall 4.

[0048] Figure 1c ) illustrates the cutting operation on the end section 5. An end-side cut is made on the end section 5. The cutting tool is denoted by the reference numeral 9. The cut is made along a cutting line B at an angle perpendicular to the longitudinal axis L of the wall 3 of the initial slab 13.

[0049] The cutting operation takes place in the region of the leg 6 with the bevel 7. During the cutting, the end piece 8 is removed. A butt surface 10 extending perpendicularly to the longitudinal axis L is formed on the end face of the end section 5.

[0050] Figure 1d ) shows the twisted profile 1 after cutting. In order to form the twisted profile 1, the initial plate blank 3 is shaped, for example, around the longitudinal axis L to produce a U-shaped or V-shaped cross-sectional profile.

[0051] The abutment surface 10 has a width b measured perpendicularly to the longitudinal axis L of the wall 4 of the twisted profile 1, which is greater than the wall thickness t1 of the wall 4 of the twisted profile 1. The ratio of the wall thickness t1 of the wall 4 of the twisted profile 1 to the width b of the abutment surface 10 is dimensioned between 1:1.1 and 1:1.5.

[0052] The bevel 7 has an axial length l. The axial length l of the bevel 7 is measured in the direction of the longitudinal axis L of the wall 4 of the twisted profile 1. The axial length l is measured in the area of ​​the subsequent joint connection. The bevel 7 extends at an angle β of 25° to 60°, in particular 30° to 45°, relative to the longitudinal axis L of the wall 4 of the twisted profile 1. The ratio of the axial length l of the bevel 7 to the wall thickness t1 of the wall 4 of the twisted profile 1 is dimensioned to be between 1:1 and 1:5. The bevel 7 is located on the side of the end section 5 of the twisted profile 1 that forms an acute angle β with the side arm 11.

[0053] To produce the combined tie rod axle 2, a side arm 11 made of steel is provided. The side arm 11 comprises a wall 12 with a wall thickness t2. The wall thickness t1 of the wall 4 of the torsion profile 1 is greater than the wall thickness t2 of the wall 12 of the side arm 11.

[0054] The twisted profile 1 has a joining surface 13 on the end section 5. The joining surface 13 comprises the chamfer 7 and the end-side abutment surface 10.

[0055] The side arm 11 has a joining surface 14 .

[0056] The torsion profile 1 and the side arm 11 are joined in a material-locking manner by means of a welded connection. In order to produce the welded connection, the torsion profile 1 and the side arm 11 are positioned relative to one another. Figure 2a The twisted profile 1 and the side arm 11 are arranged at an angle α relative to each other, in particular the twisted profile 1 is joined to the side arm 11 in a T-joint at a right angle α.

[0057] The joint surface 13 of the twisted profile 1 and the joint surface 14 of the side arm 11 are opposite to each other. The joint surface 10 extends perpendicularly to the longitudinal axis L of the wall 4 of the twisted profile 1. The joint surface 10 is oriented parallel to the joint surface 14 of the side arm 11. A V-shaped joint gap 15 is formed between the joint surface 13 of the twisted profile 1 and the joint surface 14 of the side arm 11. A gap section 16 formed parallel to the joint surface 14 of the side arm 11 is connected to the deepest part of the V-shaped joint gap 15. The inclined surface 7 extends at an acute angle toward the end face 17. The inclined surface 7 ends on the end face 17. The joint surface 10 is connected to the inclined surface 7 at an obtuse angle.

[0058] The integrally bonded joint is achieved by means of a weld seam 18, such as Figure 2b ). The bevel 7 and the V-shaped joint gap 15 make the weld 18 highly efficient, wherein a high penetration depth is achieved in the twisted profile 1.

[0059] By means of the weld preparation and the formation of the bevel 7 in the joint surface 13 on the twisted profile 1 and the V-shaped configuration of the joint gap 15, a welded connection with satisfactory quality and service life is formed between the twisted profile 1 and the side arm 2. The penetration depth of the weld 18 on the twisted profile 1 can be significantly increased without burning through on the side arm 11. The weld 18 meets the highest strength requirements, so that the service life of the combined tie rod axle 2 can be increased overall without increasing its overall weight.

[0060] Figure 3 A combined tie-rod axle 2 is shown having a torsion profile 1 and two side arms 11. The torsion profile 1 connects the two side arms 11 and is welded thereto. The torsion profile 1 comprises a wall 4 having a wall thickness t1. Each side arm 11 comprises a wall 12 having a wall thickness t2. The wall thickness t1 of the wall 4 of the torsion profile 1 can be greater than the wall thickness t2 of the side arm. See the illustrations of FIGS. 1 and 2 for explanation. The torsion profile 1 has a U-shaped cross section comprising two side legs 19 connected by an apex section 20. The torsion profile is butt-jointed to the wall 12 of the side arm with an end section 5. The joining surface 13 on the end section 5 of the torsion profile 1 is adapted to the outer contour of the wall 12 of the side arm 11.

[0061] Through the arrow P1 Figure 3 Schematically shown in FIG is the length of the side leg 19, with which the end section 5 of the twisted profile abuts the outer circumference of the side arm 11. This is approximately 180°+ / −15° relative to the circumference of the side arm, which is circular in cross section.

[0062] The length of the length section 21 of the lateral leg 19, in which the bevel 7 is arranged on the inner side of the lateral leg 19, is indicated by the arrow P2. The bevel 7 is arranged in the lower length section 21 of the lateral leg 19. In particular, the bevel 7 extends over two thirds, in particular approximately half, of the length of the lateral leg 19. The bevel 7 extends over a circumferential section of approximately 90°+ / -15° relative to the cross section of the side arm 11. The bevel 7 is arranged in the lower length section 21 of the lateral leg 19 starting from the free leg end.

[0063] Figure 4 The front view of the joint surface 13 on the end section 5 of the twisted profile 1 is shown. The twisted profile 1 comprises a wall 4 with a wall thickness t1. The chamfer 7 produced according to the invention is arranged in the joint surface 13 on the end section 5 of the twisted profile 1. The chamfer 7 extends on the inside of the lateral leg 19 of the twisted profile 1.

[0064] The bevel 7 is arranged in a lower length section 21 of the side leg 19 starting from the free leg end. The tangential length of this length section 21 is indicated by the arrow P2. In the embodiment shown, the bevel 7 extends approximately over half of the length of the side leg 19.

[0065] Figure 5 The front view of the joint surface 13 in an alternative design of the end section 5 of the twisted profile 1 is shown. Figure 4 Unlike the embodiment of the present invention, the bevel 7 is arranged on the outside of the side leg 19 of the twisted profile. The bevel 7 is produced by cutting as in the other embodiments. The bevel 9 extends in the lower length section 21 of each side leg 13 starting from the free leg end. In other respects, this embodiment is different from Figure 4 And corresponding to the implementation methods described in the related description.

[0066] List of reference numerals:

[0067] 1Twisted profile

[0068] 2 combined tie rod axle

[0069] 3 Initial slab

[0070] Wall 41

[0071] 5 End section

[0072] 6 legs

[0073] 7 bevel

[0074] 8-terminal parts

[0075] 9- Cutting tools

[0076] 10. Docking surface

[0077] 11 Side Arm

[0078] 1211 Wall

[0079] 13 Joint surface

[0080] 14Joint surface

[0081] 15Joint gap

[0082] 16 Gap Segments

[0083] 17 End face side

[0084] 18 Welds

[0085] 19 side legs

[0086] 20 Vertex Segments

[0087] Length segment of 2119

[0088] bWidth

[0089] B cutting line

[0090] L longitudinal axis

[0091] t1 wall thickness

[0092] t2 wall thickness

[0093] α angle

[0094] β angle

[0095] The length of l7

Claims

1. A combined tie-rod axle, comprising two side arms (11) and a torsion profile (1), wherein the torsion profile (1) comprises a wall (4) having a wall thickness (t1) and the side arms (11) each comprise a wall (12) having a wall thickness (t2), and the torsion profile (1) has a joining surface (13) on each end section (5) and the side arms (11) each have a joining surface (14), the torsion profile (1) and the side arms (11) being connected at their mutually opposite joining surfaces (13, 14) by means of a weld seam (18), characterized in that: The joining surface (13) on the end section (5) of the twisted profile (1) has a chamfer (7) produced without cutting, and the end section (5) of the twisted profile (1) has a butt surface (10) on the end side, the butt surface (10) having a width (b) measured perpendicularly to the longitudinal axis (L) of the wall (3) of the side arm (2), which is greater than the wall thickness (t1) of the wall (3) of the side arm (2).

2. The combined tie rod axle according to claim 1, characterized in that: The wall thickness (t1) of the wall (4) of the twisted profile (1) is greater than the wall thickness (t2) of the wall (12) of the side arm (11).

3. The combined tie rod axle according to claim 1, characterized in that: The wall thickness (t1) of the wall (4) of the twisted profile (1) is smaller than the wall thickness (t2) of the wall (12) of the side arm (11).

4. The combined tie rod axle according to any one of claims 1 to 3, characterized in that: The abutment surface (10) extends substantially perpendicularly to the longitudinal axis (L) of the wall (34) of the torsion profile (1).

5. The combined tie rod type axle according to claim 4, characterized in that: The docking surface (10) is connected to the inclined surface (7).

6. The combined tie rod axle according to any one of claims 1 to 5, characterized in that: The bevel (7) extends at an angle (β) of 25° to 60°, in particular 30° to 45°, relative to the longitudinal axis (L) of the wall (4) of the twisted profile (1).

7. The combined tie rod axle according to any one of claims 1 to 6, characterized in that: The inclined surface (7) has an axial length (l), and the ratio of the axial length (l) of the inclined surface (7) to the wall thickness (t1) of the wall (4) of the twisted profile (1) is dimensioned to be between 1:1 and 1:1.

5.

8. The combined tie rod type axle according to claim 7, characterized in that: The ratio of the wall thickness (t1) of the wall (4) of the twisted profile (1) to the width (b) of the abutment surface (10) is dimensioned to be between 1:1.1 and 1:1.

5.

9. The motor vehicle component according to any one of claims 1 to 8, characterized in that The bevel (7) is arranged in a longitudinal section (21) starting from a free end of the wall (4) of the first component (1).

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