FRONT STRUCTURAL ARRANGEMENT FOR A MOTOR VEHICLE

Description

[0001] The present invention relates to a front structure assembly for a motor vehicle that ensures controlled deformation during impacts.

[0002] This deformation aims to absorb the maximum amount of energy during impacts in order to protect the equipment and people involved.

[0003] Commonly known motor vehicles typically include a passenger compartment and an engine compartment located at the front of the vehicle and separated from the passenger compartment by a firewall.

[0004] They also include two substantially parallel side members which extend longitudinally at a distance from each other through the bulkhead and into the engine compartment.

[0005] Approximately directly above the apron, the vehicle includes a cradle that extends transversely and from which two extensions run under the engine compartment. These two extensions themselves run approximately directly above the two longitudinal members and are generally suspended from them by means of a suspension component.

[0006] The extensions are respectively extended by shock absorbers commonly called «crash-box "

[0007] The vehicle also includes a technical front end, which notably includes the vehicle's radiator. This technical front end extends significantly to the area of ​​the shock absorbers.

[0008] Therefore, the compression of the front of the motor vehicle in the event of a collision is achieved by the controlled deformation of elements located behind and in front of the technical front face of the vehicle, a part in the upper track in the extension of the two longitudinal members and a part in the lower track by means of the shock absorbers.

[0009] Document FR3009255A1 discloses a front structure assembly for a motor vehicle according to the preamble of claim 1.

[0010] However, the length of the front part of motor vehicles tends to be reduced and the space required for the implementation of deformable elements adapted to absorb shocks decreases accordingly.

[0011] Also, a problem that arises and that the present invention aims to solve is to implement a shorter front structure assembly for a motor vehicle, but whose shock absorption qualities are preserved.

[0012] To this end, a front structure assembly for a motor vehicle is proposed, comprising: a bulkhead separating a passenger compartment from an engine compartment and two upper front longitudinal members extending parallel to each other from said bulkhead and through said engine compartment in a direction opposite to said bulkhead; a subframe extending transversely substantially vertically from said bulkhead; two extensions extending vertically from said two longitudinal members from said subframe to a connecting end, each of said extensions comprising, on the one hand, a rigid rear portion connected to said subframe and a deformable front portion extending to said connecting end, and on the other hand, at least one anchoring point located at a distance from said subframe, said two extensions being respectively suspended from said front longitudinal members by two suspension members, each suspension member being connected to said at least one anchoring point.Said at least one anchor point is located on said connecting end of said extensions.

[0013] Thus, a key feature of the invention lies in the elimination of traditional shock absorbers and the implementation of extensions that incorporate the shock-absorbing function. This allows the deformable elements to be moved further back into the engine compartment without compromising controlled deformation in the event of a collision. Consequently, the front structure of motor vehicles can be shortened without compromising safety in a crash. Moreover, the repairability of the front structure is improved after a collision, as the extension can then be completely replaced.

[0014] According to the invention, the rigid rear and deformable front parts are substantially conical in shape. As will be explained in more detail later in the description, the use of conical elements allows for better control of the deformation along the axial direction of these elements.

[0015] Preferably, the said parts, a rigid rear and a deformable front, respectively having a base and a top, are joined together at their base. In other words, the cradle supports the top of the rigid rear extension, while the top of the deformable front section supports the anchor point of the suspension components, also called drop links, because they are part of the vehicle's front technical face or located nearby. Thus, the smallest section of the rear extension is connected to the cradle, and the smallest section of the front section receives at least one anchor point, while the larger sections of both parts are connected together. For example, two or three anchor points are provided, connected to the drop links.

[0016] Furthermore, and according to a particularly advantageous embodiment of the invention, said rigid rear and deformable front parts are joined together by means of an extended annular plate between their bases.

[0017] As explained in more detail below, the rigid rear and deformable front sections are metallic and are welded to opposite faces of the annular plate. The rear and front sections extend approximately coaxially. In this way, the annular plate stops the deformation stresses propagating through the deformable front section of the extensions.

[0018] Moreover, the annular plate helps to prevent the transfer of rotational forces that the front part experiences in certain cases of impact, to the rear part.

[0019] According to a preferred, but not limiting, embodiment of the invention, the rigid rear and deformable front parts have a rectangular cross-section. This results in improved torsional strength of the extensions.

[0020] Furthermore, the rigid rear and deformable front sections are hollow. Consequently, the extensions offer significant mechanical strength relative to the mass of metal used.

[0021] Furthermore, according to a preferred embodiment, the rigid rear and deformable front sections are produced by stamping closed sheet metal. The two opposing free edges of sheet metal are thus, after stamping, welded together to form both the front and rear sections of the extension.

[0022] Furthermore, and particularly advantageously, the deformable front section is planned to be made of thinner sheet metal than the rigid rear section. This will enhance the deformation of the front section in the event of an impact.

[0023] Furthermore, the deformable front section features multiple openings. These openings create preferred deformation zones. For example, openings are made progressively along the four edges of the extended front section. This creates preferred deformation lines with a longitudinal component, allowing the front section to be compressed, for example, in an S-shape and / or an accordion shape.

[0024] Also, the connecting ends of these extensions are joined together by a front crossmember. In this way, in the event of an impact, the front crossmember distributes the deformation forces across the two deformable front sections of the extension.

[0025] Furthermore, the rigid rear section of each of these extensions is removably connected to the cradle. Consequently, in the event of an impact and damage to the deformable front section, the extension can be easily replaced.

[0026] 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 attached drawings in which: [ Fig. 1 ] is a partial schematic three-quarter front perspective cutaway view of a front structure assembly of a motor vehicle according to the invention; [ Fig. 2 ] is a schematic side view showing a detail element illustrated on the [ Fig. 1 ]; [ Fig. 3 ] is a schematic perspective view of the detail element shown on the [ Fig. 2 ]; [ Fig. 4 ] is a partial schematic exploded perspective detail view of the [ Fig. 1 ]; [ Fig. 5A ] is a schematic perspective view of the detail element as shown on the [ Fig. 2 ] in a first state; and, [ Fig. 5B ] is a schematic perspective view of the detail element as shown on the [ Fig. 5A in a second state.

[0027] There [ Fig. 1 ] shows, viewed from three-quarters front right and partially, a front structure assembly 10 of a motor vehicle according to the invention.

[0028] We find the trihedron x,y,z indicating respectively, a first longitudinal direction, from the front to the rear of the vehicle, a second direction, transverse, extending from the left to the right of the vehicle in a driving situation, and a third direction, vertical, upward.

[0029] There [ Fig. 1 Figure 12 shows a front face and, at the rear, an engine compartment 14. It also partially shows a left upper front side member 16 extending along the longitudinal direction of the motor vehicle. Directly above the left upper front side member 16, a left extension 18 extends along the longitudinal direction x of the vehicle. It extends from a subframe 20 to a connecting end 22. The subframe extends transversely along the y direction of the vehicle, as will be explained below.

[0030] The left extension 18 has a rigid rear part 24, connected to the cradle 20 and in the extension, a deformable front part 26 extending to the connecting end 22. Also, the deformable front part 26 has at least one anchorage point 28 located on the connecting end 22 and which will be described in more detail below.

[0031] In addition, a technical front-facing pendant 30 in the form of a plate, extending along the third vertical direction, connects the connecting end 22 of the deformable front part 26 to the upper left front spar 16 via the anchor point 28. In this way, the left extension 18 is suspended from the upper left front spar 16 via the pendant 30.

[0032] It will be observed that the plate in which the pendant 30 is made has two free lateral edges folded back to increase its resistance to deformation.

[0033] The same elements are found symmetrically on the right side of the vehicle. Also, the two connecting ends, left 22 and right, are joined together by a front crossmember 31, partially shown here.

[0034] We will now refer to the [ Fig. 3 ] in order to describe in detail the left extension 18. It will be observed that it is identical to the right extension not shown.

[0035] We find on this [ Fig. 3 ] the rigid rear part 24 and in its extension, the deformable front part 26. Both parts 24, 26 are hollow and are substantially conical in shape with a rectangular base.

[0036] Also, the rigid rear section 24 is made from a metal plate, for example steel, with a thickness of, for example, between 1.5 mm and 2.5 mm. Advantageously, the metal plate is 2 mm thick. It is stamped and folded so that it can be closed upon itself to form the three-dimensional rear section 24.

[0037] Also, the metal plate has two opposing free edges 32, 34 which overlap on top so that they can be welded together by means of first weld beads 36.

[0038] According to another embodiment, not shown, the two opposing free edges are fitted edge to edge and are connected to each other by a single continuous weld bead.

[0039] According to yet another embodiment, not shown, the rigid rear section is made from two longitudinal U-shaped halves. Each of the longitudinal halves has two opposite edges, and the two halves are fitted edge to edge against each other. They are then joined together by weld beads straddling the two opposite edges located on the two opposite faces of the assembly thus formed.

[0040] The rear part 24 thus presents two opposing side walls 35, 37.

[0041] Also, the rear part 24 has a first base 38, opposite a first vertex 40. Through the vertex 40, two transverse cylindrical members 42, 44 are engaged. These transverse cylindrical members pass through one 37 of the two lateral walls 35, 37 and are welded against the inside of the other 35 transverse wall, respectively at the right of two orifices spaced apart from each other 46, 48. These two transverse cylindrical members 42, 44 make it possible to connect the vertex 40 to the cradle 20 as will be explained below.

[0042] The deformable front part 26, is, in the same way as the rear part 24 shown on the [ Fig. 3 ], made from a metal plate, of a significantly lower thickness, for example between 0.8 mm and 1.6 mm. Preferably, the thickness of the metal plate is 1.2 mm.

[0043] Similarly, it is stamped and folded to form the front part 26. Also, the plate has two second opposing free edges 50, 52 which overlap on the top to be welded together by means of second weld beads 54. The front part 26 has a rectangular cross-section and it also has two second opposing side walls 55, 57.

[0044] According to another embodiment of the invention, not shown, the two opposing free edges of the deformable front section are fitted edge to edge and joined together by a single continuous weld bead, similarly to the first embodiment of the rigid rear section. According to yet another embodiment, the deformable front section is constructed similarly to the rigid rear section of said other embodiment. It will be noted that the relative thickness of the metal plates used for the deformable front section 26 and for the rigid rear section 24 can be adjusted according to the desired mechanical strength of these different elements.

[0045] The deformable front part 26 has a second base 58, opposite a second vertex 60 and four longitudinal edges, three of which 62, 64, 66 appear on the [ Fig. 3 [], the last one being hidden. The second vertex 60 thus forms the connecting end of the left extension 18. Also, the second vertex 60 is connected by welding to an anchoring plate 65 extending substantially perpendicularly to the front part 26. The anchoring plate 65 thus has at least one anchoring point 28 and in this case at least two, and for example three. And its method of connection to the pendant 30 and to the front crossbar 31 will be explained in more detail below.

[0046] Also, each of the edges 62, 64, 66 has a plurality of notches 68 regularly spaced from each other and forming openings through the front part 26 of the extension. These openings aim to reduce the mechanical resistance of the front part 26 and to favor its deformation kinematics as will be explained below.

[0047] In addition, the two parts 24, 26 are joined together by their bases 38, 58 by means of an intermediate annular plate 70.

[0048] The annular plate 70, or connecting piece, is made of metal and has a thickness, for example, between 2.5 mm and 3.5 mm. According to a particularly advantageous manufacturing method, it has a thickness of 3 mm.

[0049] It also has a width and length greater than the width and length of the two bases 38, 58 of the rear parts 24 and front parts 26. And it defines a central light whose length and width are less than the length and width of the two bases 38, 58. It also has two opposite faces 72, 74 against which the two bases 38, 58 of the rear parts 24 and front parts 26 are respectively applied.

[0050] The rear parts 24 and front parts 26 and the annular plate 70 are then welded together by creating third weld beads 76 at the joint between the two. Thus, the two rear parts 24 and front parts 26 extend along two coaxial mean directions coinciding with a longitudinal axis A of the extension 18.

[0051] We will now refer to the [ Fig. 4 ] on which we find, on the one hand, the left extension 18 and its deformable front part 26 with its anchoring plate 65 at the second vertex 60, and on the other hand, the front crossbar 31 and the pendant 30.

[0052] The cross member 31 is fitted on its inner face with a counter plate 75 whose shape corresponds approximately to the shape of the anchor plate 65 reflected in a mirror. Thus, the pendant 30 is adapted to extend between the anchor plate 65 and the counter plate 75 and to be sandwiched between them. Fixing screws are then adapted to be installed through the plate 65, the pendant 30, and the counter plate 75, to form the anchor points 28 and to connect them together. We find on the [ Fig. 2 The left extension 18 consists of its rear 24 and front 26 parts connected together by the annular plate 70. Also shown in this figure is the cradle 20, which has a U-shaped fixing member 78 receiving the first vertex 40 of the rear part 24 of the extension 18. The first vertex 40 thus engages between the two opposing wings of the U-shaped fixing member 78, while two fixing screws 80, 82 pass through said two opposing wings and the first vertex 40 through the two openings 46, 48 of said other lateral wall 35 and the transverse cylindrical members 42, 44 shown in the [ Fig. 3 In this way, the first vertex 40 is rigidly connected to the cradle 20.

[0053] Furthermore, the upper left front longitudinal member 16 is shown schematically in dashed lines, extending through the engine compartment 14 from a bulkhead 84 located opposite the subframe 20, and along the longitudinal direction of the vehicle. The bulkhead 84 separates the engine compartment 14 from a passenger compartment 85.

[0054] We also find the pendant 30 connecting together the connecting end 22 of the deformable front part 26 and the upper left front spar 16. We will observe that the anchor plate 65 and the counter plate 75 sandwich the pendant 30. The whole assembly is held together by means of the anchor points 28.

[0055] Obviously, we find symmetrically with respect to a median plane parallel to the plane defined by the x and z directions the same elements in the right part of the structure, that is to say a right upper front longitudinal member extending through the engine compartment from the apron and the pendant 30 connecting together the right extension and the right upper front longitudinal member.

[0056] It will be observed that the plane defined by the annular plate 70 has a normal N substantially parallel to the longitudinal direction x and that the longitudinal axis A of the extension 18 is inclined with respect to the normal N along a negative component of the third direction z.

[0057] Thus, we find the deformable front part 26 presenting its notches 68 regularly spaced from each other along its edges 62, 64 and forming openwork.

[0058] Therefore, it is understood that the deformable front part 26 of the extension 18, which extends substantially over a distance equal to one third of the length of the extension 18, plays the role of shock absorber during a front impact.

[0059] We find on the [ Fig. 5A ] following another angle, the extension 18 connected to the cradle 20 via the U-shaped fixing element 78.

[0060] Thus, when the moving vehicle encounters an obstacle that strikes the front crossmember 31 as indicated by arrow F, the deformable front section 26 deforms in a controlled manner, essentially in an accordion shape, along the longitudinal direction A. We find on the [ Fig. 5B ] the deformable front part 26 thus compressed axially.

[0061] Thanks to the annular plate 70, only the front part 26 deforms. The annular plate 70 partially blocks this deformation, preventing it from being transmitted to the rear part 24.

[0062] In addition, the rear part 24 is inherently more rigid due to the thickness of the sheet metal which constitutes it and the absence of openings, unlike the front part 26.

[0063] In addition, the annular plate 70 provides stable support which also prevents the transmission of torsional forces into the rear part 24 of the extension 18.

[0064] Thus, by preserving the integrity of the rear section 24, some elements of the engine compartment and the vehicle's passengers are protected to a certain extent. However, thanks to the way the rear section 24 of the extension 18 is attached to the cradle 20, it is easy to replace it when damaged.

Claims

1. Front structural assembly (10) of a motor vehicle, comprising: - a bulkhead (84) separating a passenger compartment (85) from an engine compartment (14) and two upper front longitudinal members (16) extending parallel to and at a distance from one another from said bulkhead (84) and through said engine compartment (14) in a direction opposite to said bulkhead; - a cradle (20) extending transversely substantially vertically in line with said bulkhead (84); - two extensions (18) extending respectively vertically in line with said two longitudinal members (16) from said cradle (20) up to a connecting end (22), each of said extensions comprising, on the one hand, a rigid rear part (24) connected to said cradle (20) and a deformable front part (26) extending up to said connecting end (22), and, on the other hand, at least one anchoring point (28) located at a distance from said cradle, said two extensions (18) being respectively suspended from said front longitudinal members (16) by two suspension members (30), each suspension member (30) being connected to said at least one anchoring point (28); said at least one anchoring point (28) being located on said connecting end (22) of each of said extensions (18); characterized in that said rigid rear part (24) and deformable front part (26) have a conical shape.

2. Structural assembly according to Claim 1, characterized in that said rigid rear part (24) and deformable front part (26) respectively have a base (38; 58) and an apex (40; 60), and in that they are joined together by their base (38, 58).

3. Structural assembly according to Claim 2, characterized in that said rigid rear part (24) and deformable front part (26) are joined together via an annular plate (70) extended between their bases.

4. Structural assembly according to any one of Claims 1 to 3, characterized in that said rigid rear part (24) and deformable front part (26) have a rectangular cross section.

5. Structural assembly according to any one of Claims 1 to 4, characterized in that said rigid rear part (24) and deformable front part (26) are hollow.

6. Structural assembly according to Claim 5, characterized in that said rigid rear part (24) and deformable front part (26) are produced by stamping metal sheets closed on themselves.

7. Structural assembly according to Claim 5 or 6, characterized in that said deformable front part (26) has a plurality of apertures (68).

8. Structural assembly according to any one of Claims 1 to 7, characterized in that the connecting ends (22) of said extensions (18) are connected together by a front crossmember (31).

9. Structural assembly according to any one of Claims 1 to 8, characterized in that said rigid rear part (24) of each of said extensions (18) is connected to said cradle (20) in a removable manner.