Ball joint attachment on a vehicle suspension arm

Abstract

The invention relates to a hybrid-mounted suspension arm (20) for a motor vehicle. The suspension arm (20) comprises: a connecting arm (22) with a first end and a second end; a first retaining surface (40); a pivot joint at the first end; a ball joint (32) at the second end, said ball joint (32) comprising a mounting plate (34) with a first mounting surface (44) and a second mounting surface (46), the first mounting surface being fixed to the first retaining surface of the second end by two fixing pins (48). The suspension arm (20) includes a retaining zone (38) with a second retaining surface (42) against the second mounting surface (46) in order to hold the first mounting surface (44) against the first retaining surface (40). Figure to be published with the abbreviation: Figure 3

Description

Title of the invention: Ball joint attachment on a motor vehicle suspension arm

[0001] The invention relates to the suspension system of a motor vehicle. The invention concerns the attachment of a ball joint to a suspension arm of a motor vehicle. The invention relates to a suspension arm of a motor vehicle. The invention also relates to a motor vehicle.

[0002] A motor vehicle comprises a front axle with wheels connected to the structure by means of suspension systems and a steering system. In this context, each wheel is connected to a dedicated support that pivots about a vertical axis. Such a steering support is indirectly connected to the structure via suspension arms; more precisely, to a ball joint mounted on the suspension arm. A suspension arm is also called a suspension triangle.

[0003] To accommodate a predefined kinematic pattern, a suspension arm is equipped with several rotating links distributed at its corners. A sealed bellows protects these links from water, dust, and chemical attack. The durability of a suspension arm linkage is less than that of the vehicle. Therefore, these links must be replaceable during maintenance.

[0004] Suspension arms are mass-produced in the automotive industry. It is therefore relevant to streamline the fastening methods to achieve cost savings. However, the fastening adaptations must remain robust since these connections are subjected to impacts when a wheel encounters an obstacle.

[0005] Document FR3064214B1 describes a motor vehicle suspension assembly comprising a lower suspension arm made of sheet metal and a ball joint including a housing for a ball joint. The suspension arm has a welded-on end plate with a tapped hole. The ball joint housing has an external thread allowing it to be inserted from above and then screwed into the tapped hole. The ball joint plate is secured with three screws. The ball joint plate receives, above the arm, successively a washer and then a nut.

[0006] Document FR3036065B1 describes a method for manufacturing a suspension triangle for a vehicle suspension system. This method comprises the following steps: a layer of continuous fiber composite material is bonded to a stamped sheet metal base to obtain a metal-composite hybrid shell; to reinforce said hybrid shell, a network of Ribs made of a composite material. The ball joint is screwed onto the triangle by the three nuts.

[0007] These solutions allow for secure attachment of the ball joint to the suspension arm. However, there is a need to reduce costs. There is also a need to reinforce this attachment, and therefore to make it more secure.

[0008] The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to simplify the attachment of a ball joint to a suspension arm of a motor vehicle. The invention also aims to optimize the cost, reliability, and strength of the attachment of a ball joint to a suspension arm of a motor vehicle.

[0009] According to a first aspect, the invention provides a suspension arm for a motor vehicle; the suspension arm comprising: a connecting arm with a first end, a second end opposite the first end; a first retaining surface; a pivot joint at the first end; a ball joint at the second end, said ball joint comprising a fixing plate with a first mounting surface, a second mounting surface opposite the first mounting surface, the first mounting surface being fixed to the first retaining surface of the second end by two fixing axes; notable in that the suspension arm includes a retaining area with a second retaining surface against the second mounting surface in order to hold the first mounting surface against the first retaining surface.

[0010] Thus, the retaining zone simplifies the fastening means connecting the ball joint. Furthermore, it uses a portion of the connecting arm to add a surface that retains the ball joint by its mounting plate.

[0011] Preferably, the second retaining surface is between the pivot joint and the fixing axes.

[0012] Preferably, the holding area comprises two vertical partitions against the fixing plate.

[0013] Preferably, the two vertical partitions connect the second mounting surface to the first mounting surface.

[0014] Preferably, the two vertical partitions, the second mounting surface and the first mounting surface delimit a mounting pocket; the fixing plate being in said mounting pocket.

[0015] Preferably, the fixing plate comprises a triangular shape with a point in the holding area.

[0016] Preferably, the joining arm comprises a first thickness, the fixing plate comprises a second thickness greater than the first thickness.

[0017] Preferably, the joining arm comprises a stamped sheet metal.

[0018] Preferably, the two fixing axes are two rivets.

[0019] Preferably, the pivot joint has a pivot axis; the ball joint is a first ball joint, the suspension arm further comprising a second ball joint; said second ball joint being in the extension of the pivot axis.

[0020] Preferably, the joining branch is profiled.

[0021] Preferably, the joining branch comprises a horizontal wall and two vertical walls extending from the horizontal wall.

[0022] Preferably, the fixing plate is under the joining branch.

[0023] Preferably, the mounting pocket is on the underside of the suspension arm.

[0024] Preferably, the ball joint comprises a housing integral with the fixing plate, a trunnion with one end in the housing; an elastic body connecting said end to the housing.

[0025] Preferably, the trunnion protrudes towards the opposite side of the second mounting surface relative to the joining arm.

[0026] Preferably, the mounting pocket is open towards the opposite of the pivot joint.

[0027] Preferably, the mounting pocket has a shape complementary to the mounting plate.

[0028] Preferably, the mounting plate includes two mounting holes, the connecting arm includes two mounting holes corresponding to the two mounting holes; the two mounting axes passing through the two mounting holes and the two mounting holes.

[0029] Preferably, the fixing plate is fixed to the joining branch by at most two fixing axes.

[0030] Preferably, the thickness of the floor is equal to the first thickness.

[0031] According to another aspect, the invention provides a suspension arm for a motor vehicle; the suspension arm comprises: a connecting arm with a first end and a second end opposite the first end; a first retaining surface; a pivot joint with a pivot axis arranged at the first end; a ball joint comprising a mounting plate fixed to the connecting arm against the first retaining surface via two mounting axes; notable in that the suspension arm includes a mounting pocket; the mounting plate being recessed into said mounting pocket. The mounting pocket allows for simplified attachment of the ball joint mounting plate.

[0032] According to another aspect, the invention proposes a motor vehicle comprising a suspension arm; remarkable in that the suspension arm conforms to the invention.

[0033] Preferably, the suspension arm is a front suspension arm.

[0034] Preferably, the motor vehicle includes a steering system with a wheel support fixed to the ball joint.

[0035] Preferably, the pivot axis of the pivot joint is arranged longitudinally.

[0036] Each feature introduced by the expression "preferably" given in relation to one of the aspects of the invention applies to all other aspects of the invention.

[0037] The invention will be well understood and other aspects and advantages will become clear upon reading the following description, given with reference to the attached figures listed below.

[0038] Fig. 1 is a side view of a motor vehicle according to the invention.

[0039] Fig. 2 shows a motor vehicle suspension arm according to the invention.

[0040] Figure 3 represents a junction between a ball joint and a connecting branch. of motor vehicle suspension arms according to the invention.

[0041] Fig. 4 is a view from below of one end of a suspension arm of a motor vehicle according to the invention.

[0042] Fig. 5 is a schematic cross-section of a motor vehicle suspension arm according to the invention, the cross-section being at the level of a ball joint.

[0043] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements in the motor vehicle or in the suspension arm to which it relates. It is understood that the term "include" includes the terms "consist of". The terms "external" and "internal" shall respectively designate what is oriented towards the outside of the vehicle and towards the inside of the vehicle.

[0044] In this description, the terms "longitudinal," "longitudinally," "transverse," and "transversely" are used with respect to the vehicle's frame of reference in the mounting configuration. The term "longitudinal" refers to the principal direction of travel of the vehicle. The term "transverse" refers to a direction perpendicular to the principal direction of travel of the vehicle. The term "front" refers to the principal direction of travel of the vehicle. The term "rear" refers to the opposite of the front of the vehicle.

[0045] The X-axis represents the longitudinal direction, the Y-axis represents the transverse direction, and the Z-axis represents the vertical direction of the motor vehicle. These three axes define a right-handed trihedron whose orientation is preserved throughout the figures.

[0046] In this description, the ranges of values ​​include the bounds that delimit them.

[0047] In this description, the terms "vertical" and "horizontal" are not to be understood in their strict sense. Indeed, they allow an inclination of at most 20°, preferably at most 10°, more preferably at most 5°, and even more preferably at most 2°; with respect to the strict meaning of these terms.

[0048] In this description, the technical characteristics are defined in the mounting configuration of the suspension arm, unless otherwise explicitly stated.

[0049] Throughout the description, the different figures use the same reference signs to designate identical or similar entities.

[0050] Figure 1 represents a motor vehicle 10, according to an embodiment of the invention. The motor vehicle 10 comprises energy storage means and at least one motor (not shown) adapted to drive said motor vehicle 10.

[0051] The motor vehicle 10 comprises a structure 12. The structure 12 forms an outer body, or the main frame of the motor vehicle 10. The structure 12 delineates different compartments of the motor vehicle 10, including the passenger compartment, the cargo area, and the engine compartment (not shown). The structure 12 may be formed from an assembly of stamped and welded sheet metal parts.

[0052] The structure 12 connects various parts of the motor vehicle 10, including the openings. The structure 12 forms a mounting support for the powertrain, the suspension systems 14, the steering system 16, and the braking systems (not shown). The steering system 16 is coupled to the front suspension systems.

[0053] The steering system 16 includes a wheel support 18. The wheel support 18 may be a steering knuckle. The suspension systems 14 include suspension arms 20, in particular front suspension arms associated with the front axle. Each wheel support 18 is pivotally mounted relative to the associated suspension arm 20, along a vertical pivot axis to allow directional movement.

[0054] Each suspension arm 20 is mounted to pivot relative to the structure 12 about a horizontal pivot axis, preferably a longitudinal pivot axis. When the vehicle is in motion, the suspension arm 20 oscillates vertically. The suspension arm is capable of oscillating by at least 10°; preferably by at least 20°.

[0055] The suspension arm 20 is, for example, a lower arm; the suspension system 14 optionally includes a similar upper arm. The suspension arms may be of different lengths and inclined relative to each other. A suspension spring is associated with each lower arm and is connected to the structure 12. Thus the lower arms support the structure 12. In addition, the suspension systems include shock absorbers connected to the suspension arms, such as gas shock absorbers; which dissipate the energy of the oscillations of the suspension arm 20.

[0056] Hereafter, the lower arm will be referred to as the suspension arm 20. However, this teaching also applies to each upper arm.

[0057] The motor vehicle can, for example, be a private motor vehicle or a commercial motor vehicle.

[0058] According to an alternative embodiment of the invention, the suspension arm is a rear suspension arm. The steering system is associated with the rear axle.

[0059] According to one embodiment, the motor vehicle includes a front steering system and a rear steering system.

[0060] Figure 2 shows a suspension arm 20 of a motor vehicle, according to an embodiment of the invention. The motor vehicle may correspond to the one shown in relation to Figure 1. The present suspension arm 20 is a right front arm.

[0061] The suspension arm 20 is generally horizontal. It extends longitudinally and transversely. The suspension arm 20 has a main body. It includes at least one connecting branch 22. The at least one connecting branch 22 passes through the suspension arm 20. The connecting branch 22 forms a profile, for example a U-shaped profile. It comprises one horizontal wall and two vertical walls. The at least one connecting branch 22 comprises a main branch, for example straight; and an auxiliary branch, for example curved.

[0062] The suspension arm 20 comprises a first end 24, a second end 26 opposite the first end 24; a first retaining surface; a pivot joint 28 with a pivot axis 30 which is disposed at the first end 24; a ball joint 32. The wheel support is rotatably connected to the ball joint 32. The ball joint 32 is a mechanical joint with three degrees of freedom, along three axes of rotation.

[0063] The ball joint 32 comprises a mounting plate 34 with a first mounting surface and a second mounting surface opposite the first mounting surface. The first mounting surface is fixed to the first retaining surface of the second end 26 via two fixing pins.

[0064] The ball joint 32 is a first ball joint. The suspension arm 20 further comprises a second ball joint 36; said second ball joint 36 is in line with the pivot axis 30 of the pivot joint 28.

[0065] The suspension arm 20 includes a retaining area 38. The retaining area 38 is a mounting area for the mounting plate 34. The retaining area 38 includes a second retaining surface for the mounting plate 34 against the A second mounting surface is used to hold the first mounting surface against the first retaining surface. The suspension arm 20 also has mounting pins for the mounting plate 34. The pivot pin 30 of the pivot joint 28 is arranged longitudinally. Alternatively, it is arranged transversely.

[0066] The suspension arm 20 comprises a stamped metal sheet. The metal sheet is cut and shaped by stamping. According to an alternative embodiment of the invention, the suspension arm comprises at least one sheet of fiber-reinforced composite material. According to another alternative embodiment of the invention, the suspension arm comprises a metal body machined from a solid block.

[0067] Figure 3 shows a retaining area 38 for a suspension arm 20 of a motor vehicle, according to an embodiment of the invention. The motor vehicle may correspond to the one shown in relation to one of Figures 1 to 2. The ball joint 32 has a trunnion oriented upwards and intended to be fixed to the wheel support.

[0068] The suspension arm 20 has a profiled body; such as a connecting arm 22. The suspension arm 20, in particular the connecting arm 22, comprises a retaining area 38 with a first retaining surface 40 and a second retaining surface 42. These surfaces are flat and parallel. The mounting plate 34 for the ball joint 32 comprises a first mounting surface 44 and a second mounting surface 46 opposite the first mounting surface 44, depending on the thickness of the mounting plate 34.

[0069] The first mounting surface 44 is against the first retaining surface 40. The second mounting surface 46 is against the second retaining surface 42. This configuration allows the mounting plate 34 to be locked against the connecting arm 22. It allows the first mounting surface 44 to be locked against the first retaining surface 40. Generally, the second retaining surface 42 is against the second mounting surface 46 in order to hold the mounting plate 34 against the connecting arm 22.

[0070] The suspension arm 20 includes two mounting pins 48. The mounting pins are oriented vertically. The mounting pins 48 pass through the mounting plate 34 and the connecting arm 22. They allow for tightening according to the thickness. The two mounting pins 48 are rivets. Alternatively, the two mounting pins include screws.

[0071] The mounting plate 34 comprises a triangular shape with a point in the retaining area 38. However, the mounting plate may have any other shape. It may be square or round.

[0072] The holding zone 38 comprises two vertical partitions 50 against the mounting plate 34. The two vertical partitions 50 connect the second holding surface 42 to the first holding surface 40. The two vertical partitions 50, the second The mounting surface 46 and the first retaining surface 40 define a mounting pocket 52. The fixing plate 34 is embedded in the mounting pocket 52. It is fitted into said mounting pocket 52. This aspect allows the fixing plate 34 to be locked.

[0073] The second retaining surface 42 is arranged between the pivot joint and the fixing axes 48. The second retaining surface 42 is transverse between them. The second retaining surface 42 allows for locking one end of the fixing plate 34 that is opposite the fixing axes 48. This counteracts the leverage effect and thus limits the mechanical stresses experienced by the fixing axes 48.

[0074] In the present embodiment, the fixing plate 34 is below the connecting branch 22. According to an alternative of the invention, the fixing plate is above the connecting branch.

[0075] Figure 4 shows a second end 26 of a suspension arm 20 of a motor vehicle, according to an embodiment of the invention. The motor vehicle may correspond to the one shown in relation to one of Figures 1 to 3. The connecting arm 22 is shown without the ball joint for clarity.

[0076] The connecting arm 22 comprises a horizontal wall 54 and two vertical walls 56 extending upwards from the horizontal wall. They project upwards. The underside of the horizontal wall 54 forms the first retaining surface 40. The horizontal wall 54 forms a base. It has stiffening bosses. These walls define a channel. The vertical walls 56 stiffen the suspension arm 20.

[0077] The retaining area 38 includes a mounting pocket 52. The mounting pocket 52 is open opposite the pivot joint. The mounting pocket 52 is located on the underside of the suspension arm 20. When replacing the ball joint, it is removed by taking out the mounting pins and then removing the mounting plate from the mounting pocket 52. A new ball joint is installed by reversing these steps. This makes the replacement operation quick and ergonomic.

[0078] A floor 60 connects the vertical partitions 50. The floor 60 forms the second retaining surface 42. The first retaining surface 40 and the second retaining surface 42 are opposite each other. In one embodiment, the floor 60 and the vertical partitions 50 are welded to the connecting branch 22.

[0079] According to one embodiment, the mounting pocket 52 is closed by a back panel 62. The back panel 62 extends vertically. It connects the vertical partitions 50 and the floor 60. The back panel 62 optimizes the locking of the fixing plate. It provides transverse support.

[0080] According to an alternative embodiment of the invention, the mounting pocket is free of a bottom partition. Thus, the mounting pocket has a through passage. This simplifies its construction. The retention area then forms a bridge.

[0081] The retaining zone 38 comprises two vertical partitions 50 designed to abut against the mounting plate. The two vertical partitions 50 physically join the second retaining surface 42 to the first retaining surface 40. Thus, the retaining zone 38 forms a box whose interior space accommodates the mounting plate in order to immobilize one end of it.

[0082] At the second end 26, the connecting arm 22 includes two fixing holes 58. Depending on the main elongation of the connecting arm 22, the second retaining surface 42 is at a distance from the two fixing holes 58 and / or the two fixing axes.

[0083] Figure 5 shows a cross-section of a second end of a suspension arm 20 of a motor vehicle, according to an embodiment of the invention. The motor vehicle may correspond to the one shown in relation to one of Figures 1 to 4.

[0084] The suspension arm 20 comprises a connecting arm 22 with a first end, a second end 26 opposite the first end; a first retaining surface 40, a second retaining surface 42 opposite the first retaining surface 40. The suspension arm 20 further comprises a pivot joint; a ball joint 32 at the second end 26. The ball joint 32 is equipped with a mounting plate 34 with a first mounting surface 44, a second mounting surface 46. The mounting plate 34 forms a plate. It provides the basic assembly function. The first mounting surface 44 is held against the first retaining surface 40 by means of two mounting pins 48 (only one shown).

[0085] The first retaining surface 40 and the second retaining surface 42 define a retaining zone 38. They enclose the mounting plate 34. They fit respectively with the first mounting surface 44 and the second mounting surface 46 in order to retain the mounting plate 34. The mounting pocket 52 has a shape complementary to the mounting plate 34. The mounting plate includes a point 76 in the retaining zone 38, in particular in the mounting pocket 52.

[0086] Thus, the suspension arm 20 provides a hybrid fixing of the fixing plate 34 since the latter is held both by fixing pins 48, and by the retaining zone 38 which provides additional locking to the fixing pins 48. This solution provides a robust fixing, and saves one fixing pin at the second retaining surface 42. In this way the invention contributes to safety and simplicity.

[0087] According to one embodiment, the retaining area forms a retaining hook whose hollow includes the second retaining surface.

[0088] According to an alternative embodiment of the invention, the retaining zone comprises a strip cut into the first retaining surface and vertically separated from the joining branch by stamping. The first retaining surface then has an opening aligned with the second retaining surface. The retaining area forms a closed loop.

[0089] The connecting arm 22 comprises a first thickness 64. The fixing plate 34 comprises a second thickness 66 greater than the first thickness 64. The second thickness 66 represents from 110% to 350%, preferably from 150% to 250%, of the first thickness 64. The thicknesses are average thicknesses. The first thickness 64 corresponds to the thickness of the horizontal wall 54. These thicknesses optimize mechanical strength and weight.

[0090] The ball joint 32 comprises a housing 68 integral with the mounting plate 34, a trunnion 70 with an end 72 in the housing 68; and a flexible body 74 connecting said end 72 to the housing 68. The flexible body 74 is made of rubber or elastomer. It fills the housing 68 around the end 72. The end 72 forms a spherical head. The trunnion 70 projects away from the second mounting surface 46 relative to the connecting arm 22.

[0091] The mounting plate 34 includes two mounting holes (not shown), the connecting arm 22 includes two mounting holes corresponding to the two mounting holes. The two mounting shafts 48 pass through the two mounting holes and the two mounting holes.

[0092] According to one embodiment, the joining arm comprises steel or aluminum.

[0093] According to a preferred embodiment, the suspension arm is made of a plastic or composite material. The plastic material may include a thermoplastic or thermosetting material. According to a preferred embodiment, the plastic material is selected from the group comprising polypropylene, polyamide, polyphthalamide, polyetheretherketone, polyphenylene sulfide, polyamide-imide, polyetherimide, polyarylamide, polyepoxide, unsaturated polyester, vinyl ester, or polyester-vinylester resins. For example, the composite material comprises a matrix of a plastic material as described above with reinforcement. For example, the reinforcement comprises glass or carbon fibers.

[0094] The suspension arm comprises at least 10% by weight of recycled plastic material based on the total weight of the plastic material; preferably from 10 to 80% by weight; more preferably from 20 to 60% by weight or from 30 to 40% by weight. The use of recycled plastic material reduces the vehicle's environmental footprint.

[0095] The invention comprises the combination of all the embodiments illustrated by all the figures.

[0096] Figures 2 to 4 are isometric views. They each respect a specific scale, real angles and real proportions.

Claims

Demands

1. Suspension arm (20) for a motor vehicle (10); the suspension arm (20) comprising: a connecting arm (22) with a first end (24), a second end (26) opposite the first end (24); a first retaining surface (40); a pivot joint (28) at the first end (24); a ball joint (32) at the second end (26), said ball joint (32) comprising a mounting plate (34) with a first mounting surface (44), a second mounting surface (46) opposite the first mounting surface (44), the first mounting surface (44) being fixed to the first retaining surface (40) of the second end (26) by two fixing pins (48);characterized in that the suspension arm (20) comprises a retaining area (38) with a second retaining surface (42) against the second mounting surface (46) in order to retain the first mounting surface (44) against the first retaining surface (40).

2. Suspension arm (20) according to claim 1, characterized in that the second retaining surface (42) is between the pivot joint (28) and the fixing axes (48).

3. Suspension arm (20) according to any one of claims 1 to 2, characterized in that the holding area (38) comprises two vertical partitions (50) against the mounting plate (34); preferably, the two vertical partitions (50) connect the second mounting surface (46) to the first mounting surface (44).

4. Suspension arm (20) according to claim 3, characterized in that the two vertical partitions (50), the second mounting surface (46) and the first mounting surface (44) delimit a mounting pocket (52); the fixing plate (34) being in said mounting pocket (52).

5. Suspension arm (20) according to any one of claims 1 to 4, characterized in that the fixing plate (34) comprises a triangular shape with a point (76) in the holding area (38).

6. Suspension arm (20) according to any one of claims 1 to 5, characterized in that the connecting arm (22) comprises a first thickness (64), the fixing plate (34) comprises a second thickness (66) greater than the first thickness (64).

7. Suspension arm (20) according to any one of claims 1 to 6, characterized in that the connecting arm (22) comprises a stamped sheet metal, and / or the two fixing axes (48) are two rivets.

8. Suspension arm (20) according to any one of claims 1 to 7, characterized in that the pivot joint (28) has a pivot axis (30); the ball joint (32) is a first ball joint, the suspension arm (20) further comprising a second ball joint (36); said second ball joint (36) being in the extension of the pivot axis (30).

9. Motor vehicle (10) comprising a suspension arm (20); characterized in that the suspension arm (20) conforms to any one of claims 1 to 8; preferably, the suspension arm (20) is a front suspension arm.

10. Motor vehicle (10) according to claim 9, characterized in that the motor vehicle (10) comprises a steering system (16) with a wheel support (18) fixed to the ball joint (32).