Axle for motor vehicle

Abstract

The invention relates to an axle (1) for a motor vehicle comprising: - a first axle arm (2); - a first axle head (8) comprising a mounting flange (13), a rear mounting wing (16) and a front mounting wing (15); and - a reinforcement plate (18) which rests against the first axle arm (2) and is fixed to said first axle arm (2), said reinforcement plate (18) being interposed between an upper portion (19) of the contact edge (17) of the rear mounting wing (16) and the first axle arm (2). Figure to be published with the abbreviation: Fig. 3

Description

Title of the invention: Axle for motor vehicle

[0001] The invention relates to the field of motor vehicles.

[0002] The invention relates more specifically to a flexible axle and in particular to a flexible axle of a motor vehicle.

[0003] A flexible rear axle, also called a deformable axle or semi-rigid axle, is a component commonly used in motor vehicles. The flexible axle is generally associated with coil springs and shock absorbers that work together to absorb shocks and maintain vehicle stability.

[0004] The flexible axle comprises two axle arms, each connecting one of the rear wheels to the body, and a torsion beam connecting the two axle arms to each other. Each axle arm is equipped with an axle head, which is welded to said axle arm and serves as a mounting point for a wheel bearing.

[0005] The axle head comprises a mounting flange having openings for receiving fasteners to secure the wheel bearing to the axle head and two mounting wings, folded perpendicularly to the mounting flange, which allow the axle head to be welded to the axle arm. Each of the mounting wings has a contact edge with a concavity that is complementary to the convexity of the axle arm and along which the axle head is fixed to the axle arm.

[0006] The inventors have found that the forces transferred from the axle head to the axle arm can generate high stress levels in the area of ​​the axle arm where the rear fixing wing of the axle head is welded, which can lead to punching deformation of the axle arm.

[0007] Also, a problem which arises and which the present invention aims to solve is to provide a more resistant axle.

[0008] In order to solve this problem, and according to a first object, an axle for a motor vehicle is proposed comprising: - a first axle arm; - a first axle head comprising a mounting flange, a rear mounting wing, and a front mounting wing; the mounting flange having openings, each intended to receive a fastener for attaching a wheel support to the first axle head; the front mounting wing and the rear mounting wing projecting from the mounting flange and having a bearing edge with a concavity into which the first axle arm is at least partially inserted and along which said bearing edge is welded to the first axle arm; and - a reinforcement plate which rests against the first axle arm and is fixed to said first axle arm, said reinforcement plate being interposed between an upper portion of the landing edge of the rear fixing wing and the first axle arm.

[0009] Thanks to the reinforcement plate, the forces transferred from the rear mounting wing to the axle arm are better distributed over a wider area. This reduces stress levels in this area and thus prevents punching shear deformation of the axle arm.

[0010] According to embodiments, the axle may include one or more of the following characteristics.

[0011] According to one embodiment, the wheel support member is a wheel bearing.

[0012] According to one embodiment, the upper surface of the axle arm is flat, the support plate and axle arm being in flat contact against each other.

[0013] According to one embodiment, the wheel support member is a wheel bearing.

[0014] According to one embodiment, the front mounting wing and the rear mounting wing are perpendicular to the mounting flange.

[0015] According to one embodiment, the reinforcement plate has an outer edge which is in contact against the mounting flange.

[0016] According to one embodiment, the reinforcement plate is welded to the mounting flange by a weld formed along said outer edge.

[0017] According to one embodiment, the reinforcement plate is made of metal.

[0018] According to one embodiment, the reinforcing plate is welded to the first arm axle.

[0019] According to one embodiment, the reinforcement plate has an inner edge, opposite the mounting flange; the reinforcement plate being welded to the first axle arm by means of a weld formed along said inner edge.

[0020] According to one embodiment, the upper portion of the docking edge of the rear mounting wing is welded to the reinforcement plate.

[0021] According to one embodiment, the upper portion of the docking edge extends parallel to the flat upper surface of the reinforcement plate.

[0022] According to one embodiment, the axle includes a weld between the upper portion of the docking edge and the reinforcement plate, said weld being formed straddling the front face of the rear mounting wing and an upper face of the reinforcement plate.

[0023] According to one embodiment, the reinforcement plate has a length greater than 50% of a spacing between the front fixing wing and the rear fixing wing.

[0024] In one embodiment, the reinforcement plate extends beyond the rear mounting wing on both sides. In another embodiment, the reinforcement plate extends mainly between the rear mounting plate and the front mounting plate. In other words, more than 50% of its length, and preferably more than 80% of its length, is located between the two fixing wings.

[0025] According to one embodiment, the axle further comprises: - a second axle arm which is connected to the first axle arm by a cross member; - a second axle head comprising a mounting flange, a rear mounting wing, and a front mounting wing; the mounting flange having openings, each intended to receive a fastener for attaching a wheel support to the second axle head; the front mounting wing and the rear mounting wing projecting from the mounting flange and having a concave edge into which the second axle arm is at least partially inserted and along which said edge is welded to the second axle arm; and - a second reinforcement plate which rests against the second axle arm and is fixed to said second axle arm, said second reinforcement plate being interposed between an upper portion of the docking edge of the rear fixing wing and the second axle arm.

[0026] According to a second object, the invention also relates to a motor vehicle comprising an axle of the aforementioned type.

[0027] Other features and advantages of the invention will become apparent from the following description of particular embodiments of the invention, given by way of example but not limitation, with reference to the accompanying drawings in which:

[0028] [Fig-1] is a top view of a flexible rear axle of a motor vehicle according to the state of the art.

[0029] [Fig.2] is a detailed rear perspective view of the axle of the [Fig.1] representing in particular an axle head and its attachment to the axle arm.

[0030] [Fig.3] is a side view, from the inside out, of a left rear portion of an axle equipped with a reinforcement plate.

[0031] The orientations expressed in the description are given with reference to an orthonormal XYZ frame, shown in the figures, in which X represents the longitudinal direction, oriented from the front to the rear of the vehicle, Y the transverse direction oriented towards the right of the vehicle, and Z the vertical direction oriented towards the top of the vehicle in usual position, resting on its wheels.

[0032] Fig. 1 represents a flexible axle 1 of a rear axle of a motor vehicle. It has an H-shaped structure.

[0033] The axle 1 comprises two axle arms 2, 3. One end of each axle arm 2, 3, namely its front end 4, is articulated to the vehicle body via a flexible joint 5. Such a flexible joint 5 comprises, for example, an elastomer ring mounted radially between two metal rings. It This allows limited rotation of axle arms 2, 3 relative to the body while filtering vibrations and shocks.

[0034] The axle arms 2 and 3 are connected to each other by a cross member 6. The cross member 6 is designed to deform in torsion, particularly when the vehicle encounters irregularities in the road, which allows for limited relative movement of the rear wheels with respect to each other. This improves driving comfort by reducing the impact of bumps and potholes.

[0035] Each axle arm 2, 3 is equipped with a suspension cup 7 which is welded to said axle arm 2, 3 and which supports one end of one of the suspension springs. Each axle arm 2, 3 is also attached to one end of a suspension damper, not shown.

[0036] Each of the axle arms 2, 3 is also equipped with an axle head 8 which is intended to secure said axle arm 2, 3 a wheel bearing 9 and a braking device 10.

[0037] The wheel bearings 9 are advantageously of the third generation. Such wheel bearings 9 integrate the wheel bearing and the hub into a single compact unit. In addition, one of the rings of the wheel bearing 9 is equipped with a flange having holes for the passage of the fasteners 11 for attaching the wheel bearing 9 and the stator 12, i.e., the fixed part, of the braking device 10 to the axle head. The other ring of the wheel bearing 9 is equipped with a flange ensuring the attachment of the rim and the rotor, i.e., the moving part, of the braking device.

[0038] The axle head 8 is made of metal, preferably steel, and is attached and welded to the axle arm 2, at a rear end of said axle arm 2.

[0039] The axle head 8 has a mounting flange 13 which serves as a fixing point for the wheel bearing 9 and has, for this purpose, openings, here four in number, intended to receive the fixing members 11.

[0040] The mounting flange 13 further includes a central opening 14 which is provided between the holes receiving the fixing members 11. This central opening 14 makes it possible to lighten the axle head 8. It can also allow the passage of a cable connected to a sensor, such as a wheel speed sensor.

[0041] The mounting flange 13 extends in a longitudinal plane, perpendicular to the geometric axis of rotation of the wheel. The axle head 8 also includes, on each side of the mounting flange 13, two mounting wings: a front mounting wing 15 and a rear mounting wing 16, meaning that the rear mounting wing 16 is located behind the front mounting wing 15 in the longitudinal direction X of the vehicle.

[0042] The two mounting flanges 15, 16 allow the axle head 8 to be welded to the axle arm 2. The two mounting flanges 15, 16 extend along substantially perpendicular to the plane of the mounting flange 13. The mounting wings 15, 16 each have a concave edge 17. This concavity allows a portion of the axle arm 2 cross-section to fit into the mounting wings 15, 16. The mounting wings 15, 16 are welded to the axle arm 2 along the concavity of the edge 17, for example by arc welding.

[0043] To reinforce it and prevent deformations in the area where the axle head 8 is welded, each axle arm 2, 3 is equipped with a reinforcing plate 18, as shown in [Fig. 3]. The reinforcing plate 18 is made of metal and advantageously of steel.

[0044] The reinforcement plate 18 is interposed between an upper portion 19 of the docking edge 17 of the rear fixing wing 16 and the upper surface of the axle arm 2, 3. The forces transferred from the rear fixing wing 16 to the axle arm 2, 3 are therefore distributed over a larger area of ​​the axle arm 2, 3, which reduces the stress levels in this area and thus prevents its deformation.

[0045] The reinforcing plate 18 extends along the axle arm 2, 3 and rests against it, and more particularly against its upper surface. The upper surface of the axle arm 2, 3 is advantageously flat, which ensures a planar contact between the reinforcing plate 18 and the axle arm 2, 3 and further reduces the stress levels.

[0046] In addition, the upper portion 19 of the docking edge 17 of the rear attachment wing 16 extends parallel to the upper surface of the reinforcement plate 18, which is flat, thus limiting the stress concentrations in the reinforcement plate 18.

[0047] The reinforcement plate 18 extends on either side of the rear mounting wing 16 along the longitudinal axis of the axle arm 2, 3. The reinforcement plate 18 advantageously has a length greater than 50%, preferably greater than 70% and for example between 80 and 95% of the width of the axle head 8, i.e. of the spacing between the two mounting wings 15, 16.

[0048] The reinforcement plate 18 is welded to the axle arm 2, 3, more particularly via a weld 21 formed along the inner edge 20 of said reinforcement plate 18, i.e. the one opposite the mounting flange 13. Furthermore, the upper portion 19 of the landing edge 17 is welded to the reinforcement plate 18. In [Fig.3], a weld 22 is made against the front face of the rear mounting wing 16 along the upper portion 19 of the landing edge 17.

[0049] Furthermore, the reinforcing plate 18 is supported, via its outer edge 24, against the inner face of the mounting flange 13, which prevents deformation of this flange. In addition, in the embodiment shown, the reinforcing plate 18 is also welded to the mounting flange 13, via a weld 23 formed along said outer edge 24 of the reinforcing plate 18. Since it can be difficult, or even impossible, to weld the outer edge 24 of the reinforcement plate 18 to the inner face of the mounting flange 13 at the level of the fasteners 11, the weld 23 is here formed only in the area between the fasteners 11. According to an unrepresented variant, the outer edge 24 of the reinforcement plate 18 has cutouts on either side of the weld 23, which makes it possible to reduce the mass of the reinforcement plate 18 by limiting the contact surfaces to the areas that can be welded.

[0050] Furthermore, it is observed that the reinforcing bracket 18 has two holes 25, 26 which allow its positioning during its welding to the axle arm 2, 3 and to the axle head 8.

[0051] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention, as defined by the claims.

[0052] The use of the verb "comprise", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0053] In the claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Axle (1) for a motor vehicle comprising: - a first axle arm (2); - a first axle head (8) comprising a mounting flange (13), a rear mounting wing (16) and a front mounting wing (15); the mounting flange (13) having openings which are each intended to receive a fastener (11) for attaching a wheel support member to the first axle head (8); the front mounting wing (15) and the rear mounting wing (16) projecting from the mounting flange (13) and comprising a berthing edge (17) having a concavity in which the first axle arm (2) is at least partially inserted and along which said berthing edge (17) is welded to the first axle arm (2);and - a reinforcing plate (18) which rests against the first axle arm (2) and is fixed to said first axle arm (2), said reinforcing plate (18) being interposed between an upper portion (19) of the docking edge (17) of the rear fixing wing (16) and the first axle arm (2).;

2. Axle (1) according to claim 1, wherein the reinforcement plate (18) has an outer edge (24) which is in contact against the mounting flange (13).

3. Axle (1) according to claim 2, wherein the reinforcing plate (18) is welded to the mounting flange (13) by a weld (23) formed along said outer edge (24).

4. Axle (1) according to claim 1 to 3, wherein the reinforcing plate (18) is made of metal.

5. Axle (1) according to any one of claims 1 to 4, wherein the reinforcing plate (18) is welded to the first axle arm (2).

6. Axle (1) according to claim 5, wherein the reinforcing plate (18) has an inner edge (20), opposite the mounting flange (13); the reinforcing plate (18) being welded to the first axle arm (2) by means of a weld (21) formed along said inner edge (20).

7. Axle (1) according to any one of claims 1 to 6, wherein the upper portion (19) of the docking edge (17) of the rear mounting wing (16) is welded to the reinforcement plate (18).

8. Axle (1) according to any one of claims 1 to 7, wherein the reinforcement plate (18) has a length greater than 50% of a spacing between the front mounting wing (15) and the rear mounting wing (16).

9. Axle (1) according to any one of claims 1 to 8, further comprising: - a second axle arm (3) which is connected to the first axle arm (2) by a cross member (6); - a second axle head (8) comprising a mounting flange (13), a rear fixing wing (16) and a front fixing wing (15); the mounting flange (13) having openings which are each intended to receive a fixing member (11) for fixing a wheel support member to the second axle head (8); the front mounting wing (15) and the rear mounting wing (16) projecting from the mounting flange (13) and having a docking edge (17) having a concavity in which the second axle arm (3) is at least partially inserted and along which said docking edge (17) is welded to the second axle arm (3);and - a second reinforcing plate (18) which rests against the second axle arm (2) and is fixed to said second axle arm (2), said second reinforcing plate (18) being interposed between an upper portion (19) of the docking edge (17) of the rear fixing wing (16) and the second axle arm.;

10. Motor vehicle comprising one axle (1) according to any one of claims 1 to 9.

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