Axle with crossmember having an open profile and gusset
Patent Information
- Application Number
- EP2023837263
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-22
- Filing Date
- 2023-12-20
- Publication Date
- 2025-10-29
AI Technical Summary
Existing vehicle axles with stamped crosspieces and open longitudinal cavities face mechanical stress concentrations at the junctions with gussets, leading to potential arm failure and reduced lifespan, resulting in increased maintenance costs.
The axle design features a gusset with lobes extending beyond the crossmember's width to increase the contact surface area with the arm, reducing mechanical stress concentrations and enhancing torsional resistance, while the gusset's rounded ends and varying lengths further optimize stress distribution.
This design enhances the mechanical resistance and reliability of the axle, increasing its lifespan and reducing maintenance costs by distributing mechanical stresses more evenly across the gusset and arm interface.
Smart Images
Figure 1.1
Abstract
Description
[0001] TITLE: Axle with open profile crossmember and gusset
[0002] Technical field
[0003] The technical field of the invention is suspensions for vehicles such as automobiles, and more specifically concerns axles fitted with a cross member.
[0004] Previous techniques
[0005] In the field of vehicles, particularly automobiles, it is known to use flexible axles. These comprise two arms connected to each other by a crossmember. Each arm has one end designed to be connected to the vehicle body and one end designed to be connected to a wheel of the vehicle. The crossmember, through the link it forms between the arms, contributes to controlling the oscillations on tilt of the vehicle as well as the camber and steering movements induced by this tilt. The crossmember is thus a part subjected to high stresses when driving, and must meet a requirement for large amplitude deformation to perform the function of controlling oscillations and various movements.
[0006] In some cases, the crossmember is a stamped part whose profile defines an open longitudinal cavity. The cross-section of the latter varies according to the longitudinal direction of the crossmember, and therefore according to the transverse direction of the vehicle. The crossmember is connected to the arms at each of its ends. The crossmember is generally provided with a gusset at each arm. The role of the gusset is to contribute to the endurance of the welded axle, to the lateral stiffness and to the anti-roll stiffness of the axle. To do this, each gusset is placed in the open cavity in contact with an arm. In fact, a gusset creates a partially closed section near an arm. The underlying idea is to create a torsion box near the arm, the gusset locally increasing the torsional resistance of the crossmember.
[0007] This structure generally gives satisfaction, particularly on entry-level vehicles where it is often used.
[0008] However, it has nevertheless been observed, particularly during intense use, that stresses during operation are particularly high at the junction between an arm and the adjacent gusset plate. The stresses are sometimes such that the gusset plate tends to transfer its movements and deformations directly onto the arm. This results in a stress mode called punching, which is likely to lead to arm failure. In other words, the material constituting the arm is highly mechanically stressed by the gusset plate, with micro-shocks and micro-deformations. This is a phenomenon which causes, or at least can cause, progressive deterioration through fatigue. In practice, this means that cracks can appear in the structure of the arm, cracks which can develop into a breakage of the arm.
[0009] To summarize the above, a stamped crossmember, whose profile defines an open longitudinal cavity, has the disadvantage of a risk of breakage in the event of intense or prolonged use. Another disadvantage, which results from this, is that linked to a shortening of the axle's lifespan: additional costs must be incurred for vehicle maintenance.
[0010] Statement of the invention
[0011] The invention seeks to overcome the aforementioned drawbacks, with a vehicle axle whose mechanical strength is improved. More specifically, it is a question of obtaining better mechanical strength for an axle which comprises a stamped crossmember and whose profile defines an open longitudinal cavity. The invention also aims to increase the service life of an axle, and to control maintenance costs.
[0012] To do this, the invention proposes an axle for a vehicle, the axle comprising a crossmember whose profile delimits an open longitudinal cavity, the axle comprising an arm connected to one of the ends of the crossmember and an arm connected to the other of the ends of the crossmember, each arm having an end intended to be connected to the body of the vehicle and an end intended to be connected to a wheel of the vehicle, the axle further comprising at least one gusset located in the open cavity in contact with an arm, the gusset extending between a first end and a second end in a longitudinal direction aligned with the crossmember, the gusset extending between a first edge and a second edge in a transverse direction substantially perpendicular to the longitudinal direction.One end of the gusset plate contacts the arm across the width of the crossmember, and the gusset plate includes at least one lobe that extends the end contacting the arm in the transverse direction beyond the width of the crossmember.
[0013] Compared to the prior art, the contact surface between the gusset and the arm is increased. In other words, the invention enlarges the surface area for the passage of mechanical stresses between the gusset and the arm. It follows that the mechanical stresses in the materials constituting the gusset and the arm are lower. A resulting advantage is greater reliability of the axle. Its mechanical resistance is better. Subsequent advantages are an increase in the service life of an axle, and control of maintenance costs.
[0014] In one embodiment, the gusset plate includes two lobes that extend the arm-contacting end in the transverse direction beyond the width of the crossmember. This is to maximize the contact area between a gusset plate and an arm, for optimized efficiency.
[0015] Each lobe of a gusset plate has a rounded end. This structure helps reduce stress concentrations.
[0016] The end of the gusset in contact with the arm is straight. This structure is simple and easy to make.
[0017] In an alternative embodiment, the end of the gusset plate in contact with the arm has a notch. Here, it is possible to weld the gusset plate to the arm with a longer bead. The connection between the gusset plate and the arm is further reinforced.
[0018] For all embodiments, the first end and the second end of the gusset do not have the same length. One of the ends of the gusset is wider, which gives it the general shape of a trapezoid. By placing the wider end at the arm, the support surface on the latter is larger and the mechanical stresses are reduced.
[0019] The cross member comprises a first side wall and a second side wall connected by a bridge, at least one lobe of the gusset extending between the arm and a portion of at least one side wall. Thus the side wall bears on the arm indirectly, i.e. via the lobe. This preserves the structure of the arm by avoiding a concentration of forces exerted by the wall on the arm.
[0020] The axle includes a gusset located in the open cavity in contact with one arm, and a gusset located in the open cavity in contact with the other arm. This is to optimize the mechanical resistance of the axle at the level of each of the arms.
[0021] The invention also relates as such to a gusset for a vehicle axle, the gusset extending between a first end and a second end in a longitudinal direction, the gusset extending between a first edge and a second edge in a transverse direction substantially perpendicular to the longitudinal direction. The gusset comprises at least one lobe which extends one end in the transverse direction, and the end of the gusset is straight.
[0022] The invention also relates as such, in an alternative embodiment, to a gusset for a vehicle axle, the gusset extending between a first end and a second end in a longitudinal direction, the gusset extending between a first edge and a second edge in a transverse direction substantially perpendicular to the longitudinal direction. The gusset comprises at least one lobe which extends one end in the transverse direction, and the end of the gusset has a notch.
[0023] Brief description of the drawings
[0024] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which:
[0025] - Figure 1 [Fig. 1] is a partial view from above of an axle according to one embodiment of the invention,
[0026] - figure 2 [Fig. 2] is a partial view from below of the axle of figure 1,
[0027] - figure 3 [Fig. 3] is a partial view of figure 2,
[0028] - figure 4 [Fig. 4] is a perspective view of a gusset for the axle of the invention according to the preceding figures,
[0029] - Figure 5 [Fig. 5] is a flat view of a gusset for the axle of the invention according to an alternative embodiment.
[0030] Detailed description
[0031] As follows from Figures 1 and 2, a vehicle axle 1 comprises a crossmember 2, an arm 3 visible in the figures, and another arm not visible. Indeed, the axle 1 is shown partially, without this hindering the description. The visible arm 3 is located at one of the ends of the crossmember 2, while the other arm is located at the other end of the crossmember. The latter is produced, in a non-limiting manner, in the form of a cut and stamped part. It is made of any metal or metal alloy capable of deformation such as steel, a steel-based alloy, an aluminum alloy capable of deformation, or other.
[0032] The crosspiece comprises a first side wall 4, a second side wall 5, and a bridge 6 which connects the walls 4, 5 to each other. According to the embodiment described, the walls 4, 5 and the bridge 6 form a single piece. However, construction alternatives are possible. For example, it may be provided that these elements 4, 5, 6 are produced separately and then secured to each other.
[0033] The crossmember delimits a longitudinal cavity 7 which extends over its entire structure. In other words, the longitudinal cavity 7 is completely delimited by the walls 4, 5 and the bridge 6. This structure, the section of which is here substantially U-shaped, gives the crossmember good torsional capacity along a longitudinal axis.
[0034] At each of its ends, as is the case for the one with reference 3, the crosspiece 2 is secured by any means to an arm. In a non-limiting manner, the securing is carried out by welding, the crosspiece 2 and the arm 3 being made of compatible metals or metal alloys.
[0035] The arm 3 has an end 8 intended to be connected to the body of the vehicle, and an end 9 intended to be connected to a wheel support device of the vehicle. The body and the wheel support are not shown.
[0036] In addition, the axle 1 comprises a cup 10 placed at the junction of the cross member 2 and the arm 3. The cup 10 is intended to receive a portion of a damping device not shown here. The cup 10 is also made from a metal or a metal alloy and attached by welding.
[0037] As best seen in Figure 3, the axle 1 comprises a gusset 15 placed in the longitudinal cavity 7 of the cross member 2, in contact with the arm 3. The gusset 15 extends between a first end 16 and a second end 17 in a longitudinal direction aligned with the cross member 2, and the gusset extends between a first edge 18 and a second edge 19 in a transverse direction substantially perpendicular to the longitudinal direction. The references 16, 17, 18, 19 for the ends and the edges are used for ease of consideration of the figures.
[0038] Arbitrarily, the first end 16 of the gusset is in contact with the arm 3, and secured to it by any means such as a weld. The second end 17 of the gusset is connected to the bridge 6 of the crosspiece 2, again by any means such as a weld. In the same spirit, the first edge 18 and the second edge 19 of the gusset 15 are respectively connected to the first side wall 4 and to the second side wall 5 of the crosspiece 2, again by any means such as a weld. The gusset 15 closes the longitudinal cavity 7 near the arm 3. The association of the gusset 15 with the crosspiece 2 forms, at the relevant end of the latter, a torsion box. This means that the torsional resistance of the crosspiece 2 is increased at its end, near the arm 3. Consequently, the mechanical forces which pass between the crosspiece 2 and the arm 3 are intense.
[0039] This is why the gusset 15 comprises at least one lobe 20, 21 which extends the end 16 in contact with the arm 3 in the transverse direction beyond the width of the crosspiece 2. In a non-limiting manner, a first lobe 20 and a second lobe 21 are provided here. The width of the crosspiece 2 is the distance which goes from the first side wall 4 to the second side wall 5. Consequently the first lobe 20 extends in a direction away from the first wall 4, and the second lobe 21 extends in a direction away from the second wall 5.
[0040] The lobes 20, 21 increase the surface area of the gusset 15 at its first end 16. This surface is secured to the arm 3 again by welding or any equivalent means. It follows that the mechanical stresses exerted by the gusset 15 on the arm 3 are moderate. As a result, the reliability of the axle 1 is better.
[0041] It can be clearly seen in Figures 3 and 4 that the end 22 of the first lobe 20 is rounded, and that the end 23 of the second lobe 21 is rounded. These curved shapes promote the reduction of stress concentrations.
[0042] It is also observed that the first end 16 of the gusset 15 is straight. This helps to simplify manufacturing.
[0043] Alternatively, as can be seen in Figure 5, the first end 16 of the gusset 15 has a notch 25. This allows the creation of a longer weld bead between the arm 3 and the gusset 15, for increased mechanical strength.
[0044] The invention is not limited to the embodiments described, and includes all equivalents which may fall within the scope of the claims which follow.
[0045] In particular, various variant shapes may be provided for the first end 16 of the gusset 15.
Claims
CLAIMS 1. Axle (1) for a vehicle, the axle (1) comprising a cross member (2) whose profile delimits an open longitudinal cavity (7), the axle (1) comprising an arm (3) connected to one of the ends of the cross member (2) and an arm connected to the other of the ends of the cross member (2), each arm (3) having an end (8) intended to be connected to the body of the vehicle and an end (9) intended to be connected to a wheel of the vehicle, the axle (1) further comprising at least one gusset (15) located in the open cavity (7) in contact with an arm (3), the gusset (15) extending between a first end (16) and a second end (17) in a longitudinal direction aligned with the cross member (2), the gusset (15) extending between a first edge (18) and a second edge (19) in a transverse direction substantially perpendicular to the longitudinal direction,characterized by the fact that one end (16) of the gusset (15) is in contact with the arm (3) along the width of the crosspiece (2), and by the fact that the gusset (15) comprises at least one lobe (20, 21) which extends the end (16) in contact with the arm (3) in the transverse direction beyond the width of the crosspiece (2)., 2. Axle (1) for a vehicle according to claim 1, wherein the gusset (15) comprises two lobes (20, 21) which extend the end (16) in contact with the arm (3) in the transverse direction beyond the width of the crossmember (2).
3. Axle (1) for a vehicle according to claim 1 or 2, in which each lobe (20, 21) of a gusset (15) has a rounded end (22, 23).
4. Axle (1) for a vehicle according to one of claims 1 to 3, in which the end (16) of the gusset (15) in contact with the arm (3) is straight.
5. Axle (1) for a vehicle according to one of claims 1 to 3, in which the end (16) of the gusset (15) in contact with the arm (3) has a notch (25).
6. Axle (1) for a vehicle according to one of claims 1 to 5, in which the first end (16) and the second end (17) of the gusset (15) do not have the same length.
7. Axle (1) for a vehicle according to one of claims 1 to 6, in which the crossmember (2) comprises a first side wall (4) and a second side wall (5) connected by a bridge (6), at least one lobe (20, 21) of the gusset (15) extending between the arm (3) and a portion of at least one side wall (4, 5).
8. Axle (1) for a vehicle according to one of claims 1 to 7, which comprises a gusset (15) located in the open cavity (7) in contact with one arm (3), and a gusset located in the open cavity (7) in contact with the other arm.
9. Gusset (15) for a vehicle axle (1), the gusset (15) extending between a first end (16) and a second end (17) in a longitudinal direction, the gusset (15) extending between a first edge (18) and a second edge (19) in a transverse direction substantially perpendicular to the longitudinal direction, the gusset (15) comprising at least one lobe (20, 21) which extends one end (16) in the transverse direction, the end (16) of the gusset (15) being straight.
10. Gusset (15) for a vehicle axle (1), the gusset (15) extending between a first end (16) and a second end (17) in a longitudinal direction, the gusset (15) extending between a first edge (18) and a second edge (19) in a transverse direction substantially perpendicular to the longitudinal direction, the gusset (15) comprising at least one lobe (20, 21) which extends one end (16) in the transverse direction, the end (16) of the gusset (15) having a notch (25).