FR3142991A1 - Fixing a suspension arm to a motor vehicle structure spar - Google Patents

Abstract

The subject of the invention is a structure (12) of an electric motor vehicle. The structure comprises a suspension arm (26) fixing device (40) and a spar such as a rear spar (16) also called a spar. The fixing device is connected to the spar and comprises suspension arm fixing means (50). The fixing device comprises: a mounting bracket (42) for attaching to a suspension arm pivot link (30); a mounting enclosure (46) between the mounting bracket and the spar; a retaining plate (48) for fixing means in the fixing enclosure. The suspension arm connected to another suspension arm by a deformable crosspiece. Figure to be published with the abstract: Figure 3

Description

Fixing a suspension arm to a motor vehicle structure spar

The invention relates to motor vehicle suspension systems. More specifically, the invention relates to the fixing of a motor vehicle suspension system. The invention relates more precisely to a structure of a motor vehicle. The invention also relates to a motor vehicle with a suspension system connected to a structure. The invention also relates to a method of assembling a motor vehicle structure.

In order to improve comfort and handling, a motor vehicle includes suspension systems connecting each wheel to its structure. Suspension systems include elastic means that deform according to the roughness of the road. This keeps the wheels in contact with the ground. In addition, damping devices absorb the energy from the oscillations of the elastic means; in the direction of compression as well as in the direction of relaxation.

Suspension systems commonly include pivoting control arms or trailing arms. These suspension arms connect the wheels to the vehicle structure by allowing vertical travel. They have pivot connections which are fixed to the side members of the structure of the associated motor vehicle. In the example of a rear axle; the pivot links are fixed to the rear spars which are arranged on either side of the structure. Thus, the suspension arm attachment benefits from the robustness of these rear spars.

Document FR3049920B1 describes a plug-in hybrid motor vehicle having a rear part of an underbody structure. The vehicle has a multi-link suspension system attached to the rear part of the underbody structure. The system includes a rear cradle, which extends across the transverse axis of the rear wheels; and which constitutes a structural part. Furthermore, the rear cradle has a transverse zone on which two profiled arms are fixed, at each end; respectively a front arm and a rear arm. Fixing points are provided at the level of each arm of the rear cradle, so as to ensure its fixing on the one hand, with the body and, on the other hand, with the rear axle.

However, such a suspension system is complex and includes a large number of parts. In addition, the mass and size are detrimental.

Document FR3111319A1 presents a hybrid motor vehicle equipped with a gasoline engine, a rear axle comprising on each side a suspension arm carrying a rear wheel, a traction battery arranged between the two suspension arms. Furthermore, the rear axle is equipped with a deformable crossmember receiving at each end one of the suspension arms arranged in the longitudinal direction of the vehicle, which is fixed on this crossmember. The front end of each suspension arm is fixed to the body of the vehicle by a pivot having a substantially transverse axis, the rear end receiving a hub supporting a rear wheel. Each side of the vehicle body has a rear spar positioned above the rear wheel hub.

The document WO2019043309A1 presents a vehicle which comprises a chassis on which a rear axle with a deformable crossmember is fixed. The rear axle comprises on each side of the deformable crossmember a longitudinal suspension arm comprising an articulation in the front part of the suspension arm. The joint is attached to a rear part of the chassis extending longitudinally and having a clearance to accommodate the front part of the suspension arm.

These solutions provide gains in terms of security; particularly in the event of a collision. However, there is a need to maintain the integrity and tightness of the rear spar. Indeed, in the event of bad weather, there is a probability of water rising in the spar.

The invention aims to respond to at least one of the problems or disadvantages encountered in the prior art. In particular, the invention aims to preserve a spar receiving a suspension arm of a motor vehicle.

According to a first aspect, the invention proposes a motor vehicle structure, the structure comprising a spar and a suspension arm fixing device, said fixing device being connected to the spar and comprising suspension arm fixing means; remarkable in that the fixing device comprises: a mounting bracket intended to be fixed to the suspension arm; a fixing enclosure between the mounting support and the spar; a plate for holding fixing means in the fixing enclosure.

The invention adds at least one entity making it possible to position fixing means at a predefined position relative to the spar. Thus, the fixation is optimal without interfering with the spar.

It will be clearly understood that the invention proposes a motor vehicle structure, such as an electric motor vehicle with an electric battery in the base, remarkable in that the structure comprises a stack successively comprising: a spar, suspension arm fixing means , a plate for holding the fixing means, a suspension arm mounting support, said mounting support connecting the support plate to the spar.

Preferably, the fixing means are vertically between the retaining plate and the spar.

Preferably, the fixing means are vertically at a distance from the spar.

Preferably, the fixing means comprise a nut; the fixing device comprising a part for holding said nut against the holding plate; the retaining part comprises retention tabs extending vertically between the retaining plate and the mounting support.

Preferably, the fixing device comprises a spacer between the retaining plate and the mounting support, the fixing means extending vertically between the spacer and the spar; and the fixing means comprise tightening means, the fixing means being able to tighten the retaining plate towards the mounting support.

Preferably, the mounting support comprises a first horizontal support plate, and the holding plate comprises a second horizontal support plate vertically spaced from the first horizontal support plate.

Preferably, the mounting support comprises a main element with a central opening intended to receive the suspension arm; and a waterproof shell fixed to the main element and sealingly closing said central opening.

Preferably, the fixing means are between the mounting support and the spar.

Preferably, the retaining plate is between the mounting support and the spar.

Preferably, the retention tabs extend from the retaining plate towards the mounting support.

Preferably, the main element is thicker than the waterproof shell.

Preferably, the mounting support has a horizontal fixing surface at a distance from the spar, the spar being inclined relative to said fixing surface.

Preferably, the spar is a rear spar, and the structure further comprises a central spar.

Preferably, the spar is a lateral spar.

According to another aspect, the invention proposes a motor vehicle comprising a structure; remarkable in that the structure conforms to the invention.

Preferably, the motor vehicle comprises a suspension system with a suspension arm comprising a pivot connection fixed to the fixing device under the spar and the spar is a rear spar.

Preferably, the suspension arm is a first suspension arm, and the motor vehicle further comprises a second suspension arm transversely opposite the first suspension arm; and a crossmember connecting the first suspension suspension arm to the second suspension arm.

Preferably, the motor vehicle comprises a transverse direction, the pivot connection comprising a pivot axis inclined relative to the transverse direction.

According to another aspect, the invention proposes a method of assembling a motor vehicle structure, remarkable in that the structure conforms to the invention, and in that the assembly method comprises the following steps: assembly means of fixing to the holding plate; fixing the retaining plate to the mounting support; then fixing the mounting support to the spar so as to position the fixing means in the fixing enclosure at a distance from the spar.

Preferably, the motor vehicle conforms to the invention.

The invention will be well understood and other aspects and advantages will appear clearly on reading the description which follows, given with reference to the appended figures and listed below.

There is a side view of a motor vehicle according to the invention.

There shows from below a structure of a motor vehicle according to the invention.

There represents a section of a motor vehicle structure fixing device according to the invention.

There is an isometric view of a motor vehicle structure fixing device according to the invention.

There is a diagram of a method of assembling a motor vehicle structure according to the invention.

In the description which follows, the term "include" is synonymous with "include" and is not limiting in that it authorizes the presence of other elements in the structure, or the motor vehicle or other steps in the process to which it relates. It is understood that the term “understand” includes the terms “consist of”. The terms “external” and “internal” will respectively designate what is oriented towards the exterior of the vehicle and towards the interior of the vehicle.

In this description, the term “longitudinal”, the term “longitudinal”, the term “transverse”, and the term “transversely” are used according to the reference of the vehicle, in the assembly configuration. The term “longitudinal” corresponds to the main direction of movement of the vehicle. The term “transverse” corresponds to a direction perpendicular to the main direction of movement of the vehicle. The term “front” refers to the main direction of movement of the vehicle. The term “rear” refers to the opposite of the front of the vehicle.

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 trihedron whose orientation is preserved throughout the figures.

In this description, the technical characteristics are defined in the mounting configuration of the structure, unless the contrary is explicitly mentioned.

Through the description, the different figures use the same reference signs to designate identical or similar entities.

There represents a motor vehicle 10 according to the invention. The motor vehicle 10 comprises energy storage means, such as a plurality of electric batteries, and at least one electric drive motor, adapted to drive said motor vehicle 10. The electric batteries comprise a plurality of cells capable of storing energy. electrical energy.

The motor vehicle 10 comprises a structure 12. The structure 12 is adapted to support various components of the motor vehicle 10, including the electric drive motor and side openings. Structure 12 forms a box. It can be made by assembling stamped and welded sheets together. The sheets can be made of steel or aluminum alloy.

The structure 12 comprises a plurality of spars 15, including a central spar 14 and a rear spar 16 on each side. The central spars 14 and the rear spars 16 partially form the base 18 of the structure 12. Each central spar 14 extends between the front axle 20 and the rear axle 22. Each central spar 14 can be a main spar. Each rear spar 16 is also called a “spar”. Each rear spar 16 extends longitudinally at the level of the rear axle 22, and is connected at its rear end to the central spar 14.

The motor vehicle 10 comprises a suspension system 24. The suspension system 24 comprises a suspension arm 26, for example associated with the rear axle 22. The suspension arm 26 is capable of pivoting between a low position and a high position. It is generally horizontal. At rest, the inclination between the suspension arm 26 and the longitudinal direction 28 of the structure is less than or equal to 20°.

The suspension arm 26 comprises a pivot connection 30. The pivot connection 30 is a rotating mechanical joint. The pivot connection 30 is fixed to one of the spars; for example the rear spars 16. The pivot connection 30 is at the front end of the suspension arm 26.

The motor vehicle 10 may include a suspension arm 26 associated with each wheel, in particular the rear axle 22. According to one option, two suspension arms 26 of the same axle are fixed to a crosspiece not shown.

There has a base 18 of a motor vehicle. The motor vehicle may correspond to that presented in relation to the . The central beams 14 are partially shown. The axles are not shown for the sake of clarity.

The base 18 has an electric battery 32 housed between the central longitudinal members 14. The electric battery 32 is advantageously a battery capable of driving the motor vehicle. It can be covered with an aerodynamic deflector, or be housed in a battery tray protecting its electrical cells. The motor vehicle is advantageously an electric vehicle in the sense that the energy used for its propulsion is essentially electric.

The rear spars 16 are transversely between the central spars 14. They extend the structure 12 towards the rear. They are arranged above the pivot links 30 of the suspension arms 26. A crossmember 34 connects the suspension arms 26 of the rear axle. The suspension arms 26 comprise a first suspension arm and a second suspension arm; in this case a left suspension arm and a right suspension arm.

The crosspiece 34 forms a beam extending transversely and is fixed to the suspension arms 26. The crosspiece 34 is a deformable crosspiece. It comprises a central portion 36 having a thickness less than its lateral ends and/or a thickness less than the suspension arms 26. The central portion 36 can be a portion of lesser thickness or a flexible portion.

Each suspension arm 26 comprises a cup 38. Each cup 38 is intended to receive elastic means such as helical springs or gas springs. The cups 38 are at a distance from the pivot connections 30.

The structure 12 comprises at least one fixing device 40 for suspension arm 26; preferably a fixing device 40 associated with each suspension arm 26. Each fixing device 40 comprises a mounting support 42. Each mounting support 42 is fixed under the associated spar, in this case one of the rear spars 16. The fixing devices 40 are arranged at the front end of the rear spars 16, for example where they are attached to the central spars 14.

The structure 12 has a transverse direction 44. The transverse direction 44 is perpendicular to the longitudinal direction 28. The pivot connections 30 each have a pivot axis 45. The pivot axes 45 are inclined relative to each other. They are each inclined relative to the transverse direction 44, for example by at least 15°, preferably at least 30°. The pivot axes 45 can intersect in front of the pivot links 30. This arrangement increases the stability of the motor vehicle.

There presents a section of a fixing device 40 for suspension arm 26 of a motor vehicle according to the invention. The motor vehicle may correspond to that presented in relation to one of Figures 1 to 2. In the present , only the rear spar 16 is shown.

The fixing device 40 comprises a mounting bracket 42 attached to a pivot link 30 of suspension arm 26. The fixing device 40 defines a fixing enclosure 46 between the mounting bracket 42 and the rear spar 16. The fixing device 40 further comprises a plate 48 for holding the fixing means 50 in the fixing enclosure 46. The fixing enclosure houses the fixing means. The fixing means 50 are vertically between the retaining plate 48 and the rear spar 16. The retaining plate 48 is arranged vertically between the fixing means 50 and the mounting support 42. The fixing means 50 are vertically at a distance from the rear spar 16.

The fixing means 50 comprise a nut 52 and a fixing axis 54 such as a screw. The fixing pin 54 passes through the mounting support 42 and the retaining plate 48. The fixing pins 54 cooperate with the nut 52. The nut 52 is arranged between the retaining plate 48 and the rear spar 16. L The nut 52 is vertically at a distance from the rear spar 16 and the mounting support 42, just like the tip of the fixing axis 54. The fixing means 50 are capable of tightening the retaining plate towards the mounting support thanks to the fixing pin 54 and the nut 52 which form clamping means, in particular reversible.

The fixing device 40 comprises a holding part 56 for the nut 52 in the structure 12. The holding part 56 may be made of plastic material and can form a clip for holding the nut 52. The holding part 56 positions the nut 52 against the holding plate 48, more precisely against its upper face.

According to one option, the retaining part 56 comprises retention lugs 58 extending between the retaining plate 48 and the mounting support 42. The retention lugs 58 comprise vertical stops configured to retain the fixing means 50 relative to each other. to the retaining plate 48. The retention tabs 58 pass through the retaining plate 48.

The retention tabs 58 extend vertically from the retaining plate towards the mounting support 42 against which the pivot connection 30 is fixed. In particular, the pivot connection 30 comprises side branches 60 (only one visible). The side branches extend outside the suspension arm 26. The side branches 60 bear vertically against the mounting support 42, under the retention lugs 58. Thus, the spacing between the retaining plate 48 and the support mounting 42 allows the integration of the retention tabs 58 despite the presence of the side branches 60 plumb.

The fixing device 40 comprises a spacer 62 between the retaining plate 48 and the mounting support 42. The spacer 62 forms a tubular body. The spacer 62 is arranged around the fixing means 50, in particular the fixing axis 54. The fixing means 50 extend vertically between the spacer 62 and the rear spar 16.

The mounting support 42 comprises a first horizontal support plate 64, and the holding plate 48 comprises a second horizontal support plate 66 vertically spaced from the first horizontal support plate 64. The horizontal support plates ( 64; 66) are parallel. Spacer 62 separates them. They are arranged under the rear spar 16. The retaining plate 48 comprises a vertical plate 68 connecting the second horizontal support plate 66 to the second horizontal support plate 66.

The mounting bracket 42 includes a main member 70 with a central opening 72 receiving one end of the suspension arm 26. The central opening 72 is generally open horizontally. The pivot connection 30 is inside the central opening 72. The mounting support 42 further comprises a waterproof shell 74 attached to the main element 70 and sealingly closing the central opening 72. The main element 70 is thicker than the 74 waterproof shell.

The mounting support 42, in particular thanks to the main element 70, makes it possible to distribute the forces coming from the main element 70 over an extended surface of the rear spar 16. This limits the deformations generated by the suspension arm. The robustness of the structure is optimized.

Furthermore, the fixing means 50 remain at a distance from the rear spar 16; and avoid drilling. So the latter remains waterproof. In the event of crossing a ford, the impurities remain on the outside. The risk of filling is diminishing. The risk of corrosion decreases. In the event of smoke emitted by the batteries, the probability of these fumes reaching the passenger compartment decreases.

The mounting bracket 42 has a horizontal fixing surface spaced from the rear spar 16. The rear spar 16 has a lower surface inclined relative to said fixing surface.

The structure 12 therefore forms a stack presenting, from top to bottom: a spar, suspension arm fixing means, a plate for holding the fixing means, a suspension arm mounting support. The stack is above the suspension arm 26 and in particular its pivot connection 30.

There presents a suspension arm fixing device 40 for a motor vehicle structure according to the invention. The motor vehicle may correspond to that presented in relation to one of Figures 1 to 3. The rear spar is not shown for the sake of clarity.

The fixing device 40 includes a mounting bracket 42. The mounting bracket 42 is a junction bracket between the rear spar and the suspension arm (not shown). The mounting support 42 forms a housing open on two faces intended to be closed by the rear spar. The mounting support 42 delimits the fixing enclosure 46.

The retaining plate 48 is attached to the mounting bracket 42 using electric point welding 76 (PSE). For this purpose, the retaining plate 48 has fixing flanges 78 matching the interior surface of the mounting support 42, and therefore of the fixing enclosure 46.

The waterproof shell 74 engages in the central opening 72 which passes through both the retaining plate 48 and the mounting support 42. The waterproof shell 74 seals the fixing enclosure 46.

The fixing device 40 has fixing means 50 on each side; particularly on each side of the suspension arm. The retaining parts 56 are on the upper face of the retaining plate 48 and in the fixing enclosure 46. The retention lugs 58 extend vertically along the spacers 62 (only one visible) which prevent them from being crushed. The mounting support 42 and the retaining plate 48 delimit a subspace 80 of the fixing enclosure 46. This subspace 80 receives the spacers 62 and the retention lugs 58.

There presents a diagram of a process for assembling a motor vehicle structure. The motor vehicle may correspond to that presented in relation to one of Figures 1 to 4.

The process may comprise the following steps, in particular carried out in the following order:

mounting 100 of the fixing means to the holding plate;

fixing 102 of the waterproof shell to the main element;

fixing 104 of the retaining plate to the mounting support; Then

fixing 106 of the mounting support to the spar so as to position the fixing means in the fixing enclosure at a distance from the spar;

mounting 108 of the suspension arm to the mounting support using the fixing means.

At the end of the fixing step 106 of the mounting support, the fixing means are enclosed and at a distance from the spar. They are arranged in the fixing enclosure which is essentially closed by the spar.

The fixing step 104 of the holding plate and the fixing step 106 of the mounting support can be carried out using electric welding points.

According to an alternative of the invention, the step of fixing the waterproof shell can be carried out after the step of fixing the mounting support to the spar.

In the previous figures, the characteristics defined in relation to the rear spar can also be applied to the central spar; unless explicitly stated otherwise. In particular, the fixing device can be fixed against the central spar.

The structure is optionally symmetrical and includes a fixing device associated with the left spar and the right spar.

Claims (10)

Structure (12) of a motor vehicle (10), the structure (12) comprising a spar (15) and a fixing device (40) for a suspension arm (26), said fixing device (40) being connected to the spar ( 15) and comprising means (50) for fixing the suspension arm (26); characterized in that the fixing device (40) comprises: a mounting bracket (42) intended to be fixed to the suspension arm (26); a fixing enclosure (46) between the mounting support (42) and the spar (15); a retaining plate (48) for fixing means (50) in the fixing enclosure (46). Structure (12) according to claim 1, characterized in that the fixing means (50) are vertically between the retaining plate (48) and the spar (15), preferably the fixing means (50) are vertically at a distance from the spar (15). Structure (12) according to one of claims 1 to 2, characterized in that the fixing means (50) comprise a nut (52); the fixing device (40) comprising a holding part (56) of said nut (52) against the holding plate (48); the retaining part (56) comprises retention tabs (58) extending vertically between the retaining plate (48) and the mounting support (42). Structure (12) according to one of claims 1 to 3, characterized in that the fixing device (40) comprises a spacer (62) between the retaining plate (48) and the mounting support (42), the means fixing bracket (50) extending vertically between the spacer (62) and the spar (15); and the fixing means (50) comprise tightening means, the fixing means (50) being able to tighten the retaining plate (48) towards the mounting support (42). Structure (12) according to one of claims 1 to 4, characterized in that the mounting support (42) comprises a first horizontal support plate (64), and the retaining plate (48) comprises a second plate horizontal support (66) vertically at a distance from the first horizontal support plate (64). Structure (12) according to one of claims 1 to 5, characterized in that the mounting support (42) comprises a main element (70) with a central opening (72) intended to receive the suspension arm (26); and a waterproof shell (74) attached to the main element (70) and sealingly closing said central opening (72). Motor vehicle (10) comprising a structure (12); characterized in that the structure (12) conforms to one of claims 1 to 6; preferably the motor vehicle (10) comprises suspension system (24) with a suspension arm (26) comprising a pivot connection (30) fixed to the fixing device (40) under the spar (15) and the spar (15) is a rear spar (16). Motor vehicle (10) according to claim 7, characterized in that the suspension arm (26) is a first suspension arm, and the motor vehicle (10) further comprises a second suspension arm transversely opposite the first suspension arm ; and a crossmember (34) connecting the first suspension suspension arm to the second suspension arm. Motor vehicle (10) according to one of claims 7 to 8, characterized in that the motor vehicle (10) comprises a transverse direction (44), the pivot connection (30) comprising a pivot axis (45) inclined relative to in the transverse direction (44). Method of assembling a structure (12) of a motor vehicle (10), characterized in that the structure (12) conforms to one of claims 1 to 6, and in that the assembly method comprises the following steps: mounting (100) of the fixing means (50) to the holding plate (48); fixing (104) of the retaining plate (48) to the mounting support (42); then fixing (106) the mounting support (42) to the spar (15) so as to position the fixing means (50) in the fixing enclosure (46) at a distance from the spar (15).