Inner subframe member with reinforcing protrusion

Abstract

The invention relates to an internal body-body side member comprising a longitudinal U-shaped main section (520) including a vertical web (521) and two upper (522) and lower (523) flanges, said side member also comprising a U-shaped front foot (530) surmounting the front portion of said main section and comprising a vertical web (531) and two front (532) and rear (533) faces, the lower rear portion of said front foot flaring downwards to form an elbow whose free end corresponds in shape to an area of ​​the front portion of said main section; the web of said main section extending vertically upwards, at the level of a front end section (520A) located in front of said area, by means of a projection (521A) fixedly pressed against the web of said front foot by at least one electrical weld (P). Figure to be published with the abstract: Fig. 2

Description

Title of the invention: Inner subframe member with reinforcing protrusion. Technical field

[0001] The present invention relates generally to the body subframes of motor vehicles. More particularly, it relates to an inner longitudinal member of such a body subframe, provided with a reinforcing protrusion. Previous technique

[0002] The body underbody of such a motor vehicle conventionally comprises a front floor extending longitudinally between the front apron and the rear floor, and transversely between two side sill rails formed each by an inner rail and an outer rail welded to each other by their respective attachment grooves to form an elongated hollow body with a substantially square closed cross-section.

[0003] Extending longitudinally between a front wheel arch and a rear wheel arch, each inner side member comprises a main longitudinal part, a rear part commonly referred to as the "rear foot" and partially delimiting the rear wheel arch, and a front part commonly referred to as the "front foot" and partially delimiting the front wheel arch.

[0004] Produced by stamping from a sheet of metal, the front foot of an inner longitudinal member conventionally forms a hollow body with a U-shaped cross-section comprising: - a first portion extending longitudinally in line with the central main part of this inner longitudinal member, and - a second portion forming a bend with the first portion and extending upwards so as to partially delimit a front wheel arch of the vehicle.

[0005] Fixed by several points of electrical welding (PSE) to a corresponding lateral edge of the front apron, such an inner longitudinal front foot constitutes a well-known area of ​​weakness in the event of a frontal impact.

[0006] When such a shock occurs, this front foot is subjected to very strong stresses causing significant deformation of its angled portion which tends to pivot on itself, so as to cause a risk of the front door sliding inside the survival cell of the passenger compartment.

[0007] In order to overcome this problem, it is known from document FR 3 089 190 Al to add a front foot reinforcement comprising a lateral surface to be positioned vertically and, with respect to the vehicle, longitudinally, in the volume of the front foot between the wheel arch and the door recess.

[0008] This lateral surface is bounded by a front side and a rear side, and carries an interface for the passage of lower hinge elements of the front door. It further carries a first and a second rib, below the interface for the passage of lower hinge elements of the door, and extending transversely from the approach of the front side to the approach of the rear side.

[0009] It is also known from document FR 3 096 335 Al to provide a stiffening insert configured to fit the shape of the angled portion of such an inner spar front foot.

[0010] This stiffening insert is intended to be fixed securely to said front foot so as to cover said elbow, so as to lock any rotational mobility of said front foot, on a portion corresponding to said elbow, in a direction oriented towards the inside of the elbow, so as to block the rotation of the front foot in the event of a collision at the front of the vehicle.

[0011] Unfortunately, adding such an insert significantly increases the vehicle's mass. It also leads to increased management and storage costs due to the increased number of part numbers to be managed. Description of the invention

[0012] The present invention aims to improve the situation.

[0013] For this purpose, it proposes an internal underbody longitudinal member of a motor vehicle body comprising a main longitudinal U-section part including a vertical internal lateral web and two upper and lower flanges extending respectively from and along the upper and lower edges of this internal lateral web, said longitudinal member also comprising a front U-section foot surmounting the front portion of said main part and comprising a vertical internal lateral web and two front and rear faces extending respectively from and along the front and rear edges of this internal lateral web, the lower rear portion of said front foot flaring downwards so as to form an elbow whose free end covers by matching shape a surface area covering the front portion of said main part;characterized in that the internal lateral web of said main part extends vertically and upwards, at the level of a front end section located in front of said surface area of ​​overlap, by a reinforcing protrusion fixedly against the internal lateral web of said front foot by at least one electrical weld point.

[0014] The invention thus makes it possible to improve the mechanical strength of the front foot in the event of a frontal impact without the addition of an extra part and by limiting the addition of mass.

[0015] According to preferred characteristics of said inner spar according to the invention: - said reinforcement protrusion is fixed to the inner lateral web of said front foot by means of at least two said longitudinally spaced electrical welding points; - said main part and said front foot are each obtained by stamping from a sheet of metal sheet; - said upper and lower soles of said main part extend opposite the internal lateral web of this main part, respectively by an upper joining rebate folded vertically upwards and by a lower joining rebate folded vertically downwards; - said front end section of the main part lacks a top plate; and / or - the free front end of said main part is closed by a sheet metal closing piece welded via joining rebates to the internal lateral web and the lower base of this main part.

[0016] The invention also relates in a second aspect to a sheet metal body base of a motor vehicle, comprising a front floor extending longitudinally between a front apron and a rear floor, and transversely between two such internal lateral longitudinal members.

[0017] According to preferred characteristics of said body subframe according to the invention: - the internal lateral web of the front foot of each said inner longitudinal member is fixed to a corresponding lateral joining rebate of said front bulkhead; and / or - each said electrical welding point also passes through a said lateral junction groove of said front apron.

[0018] The invention finally aims, in a third aspect, at a motor vehicle comprising such a body underbody. Brief description of the drawings

[0019] The description of the invention will now be continued by a detailed description of an example embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.l] represents a perspective view from above of a body underbody of a motor vehicle comprising two internal longitudinal members according to the invention; - [Fig.2] is an enlarged perspective view taken from outside the vehicle of the junction area between the main longitudinal part and the front foot of the inner side member located on the right side of the body underbody of [Fig.1]; - [Fig.3] represents an enlarged perspective view taken from inside the passenger compartment of the junction area between the main longitudinal section and the front foot of the inner side member located on the right side of the body underbody of [Fig.1]; and - [Fig.4] is a perspective view of section along a horizontal cutting plane of the junction area between the main longitudinal part and the front foot of the inner side member located on the right side of the body underbody of [Fig.1]. Description of the implementation methods

[0020] Fig. 1 represents a top perspective view of a body underbody according to invention 1 of a motor vehicle.

[0021] An orthogonal frame XYZ comprising three axes perpendicular in pairs is defined with respect to this body base 1, namely: - an X-axis, defining a longitudinal, horizontal direction, parallel to the ground and coinciding with the general direction of movement of the vehicle - a Y-axis, defining a transverse, horizontal direction, also parallel to the ground, which, together with the X-axis, defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the ground as well as to the horizontal XY plane.

[0022] In the remainder of the description and with reference to the frame defined above, the terms "longitudinal" or "longitudinally" shall refer to a direction parallel to the X axis, the terms "transverse" or "transversely" shall refer to a direction parallel to the Y axis, and the terms "vertical" or "vertically" shall refer to a direction parallel to the Z axis.

[0023] Furthermore, and by convention, the terms "lower," "upper," "front," and "rear" shall be understood in relation to the overall orientation of the vehicle. The terms "lower" and "low" shall indicate a closer proximity to the ground in the vertical direction than the terms "upper" or "high." The term "front" shall indicate a forward-facing position of a vehicle in the horizontal direction, and the term "rear" shall indicate a rear-facing position of a vehicle in the same horizontal direction.

[0024] The terms "external" and "internal" will be used to define the relative position of an element with reference to the vehicle's median vertical longitudinal plane. The element closest to this plane will thus be described as internal, as opposed to the other element further from this same plane, which will be described as external.

[0025] With reference to this [Fig. 1], the body underbody 1 comprises a front floor 100 extending longitudinally between a front bulkhead 200 and a rear floor 300 intended to support the rear seats (also called "2nd row seats"), and transversely between two side rails 400, 500.

[0026] Extending longitudinally between a front wheel arch and a rear wheel arch, each inner side member 400, 500 comprises a rear portion 410, 510 commonly referred to as the "rear foot" and partially delimiting the rear wheel arch, a main longitudinal portion 420, 520, and a front portion 430, 530 commonly referred to as the "front foot" and partially delimiting the front wheel arch.

[0027] The rear part or "rear foot" 410, 510, the main part 420, 520 and the front part or "front foot" 430, 530 forming an inner longitudinal member 400, 500 are each obtained by stamping from a sheet of metal, preferably in double-phase steel and advantageously having a thickness of between 1.2 and 1.4 millimeters.

[0028] We will now describe in more detail and with reference to figures 2 to 4, the main part 520 and the front foot 530 of the right inner longitudinal member 500 bordering laterally the right part of the front floor 100, knowing that the left inner longitudinal member 400 bordering laterally the left part of this front floor 100 is symmetrically identical to it.

[0029] Oriented longitudinally, the main part 520 of the inner side member 500 has in section a profile substantially in the shape of a horizontal U whose concavity is turned towards the outside of the vehicle.

[0030] This main part 520 includes a vertical internal lateral web 521 fixed via electrical spot welding (ESW) to a non-visible lateral joining rebate of the front floor 100, as well as two upper 522 and lower 523 flanges extending transversely opposite this front floor 100 respectively from and along the upper and lower edges of this internal lateral web 521.

[0031] The upper 522 and lower 523 flanges each extend opposite the lateral web 521 respectively by an upper joining rebate 524 folded vertically upwards and by a lower joining rebate 525 folded vertically downwards.

[0032] Surmounting the front portion of the main part 520 to which it is fixed by welding, the front foot 530 of the inner longitudinal member 500 also has in section a profile substantially in the shape of a horizontal U whose concavity is turned towards the outside of the vehicle.

[0033] This front foot 530 comprises a vertical internal lateral web 531 fixed via spot electric welding (SEW) to a vertical lateral joining rebate 201 of the front apron 200 from and along a lateral edge of the rear portion of the apron 200, as well as two front 532 and rear 533 faces extending transversely opposite the front apron 200 respectively from and along the front and rear edges of this internal lateral core 531.

[0034] The front 532 and rear 533 panels each extend, opposite the lateral web 531, respectively by a front joining rebate 534 folded forward and by a rear joining rebate 535 folded backward.

[0035] As illustrated in particular by [Fig.3], the lower rear portion of this front foot 530 flares downwards so as to form an elbow whose free end 530A comes to cover by corresponding shape a surface area covering the front portion of the main part 520 of the longitudinal member 500 to which it is fixed by several electrical weld points (ESP).

[0036] As can be seen in [Fig.2], the front end section 520A of the main part 520 of the spar 500, located in front of this overlapping surface area, is devoid of a top flange 522 and a top joining rebate 524.

[0037] Still with reference to [Fig.2], the free front end of this main part (520) is further advantageously closed by a sheet metal closing piece 540 welded via connecting rebates 541, 542 to the internal lateral web 521 and to the lower flange 523 of this main part 520.

[0038] According to the invention and in order to improve the mechanical strength of the front foot 530 in the event of a frontal impact, the internal lateral web 521 of the main part 520 of the longitudinal member 500 extends vertically and upwards, at the level of this front end section 520A, by means of a reinforcing protrusion 521A fixedly pressed against the internal lateral web 531 of the front foot 530.

[0039] Advantageously and as illustrated by figures 2 to 4, this reinforcing protrusion 521A is fixed to the internal lateral web 531 of the front foot 530 by means of at least two longitudinally spaced electrical weld points P.

[0040] As can be seen in [Fig.4], these weld points P also pass through the lateral joining rebate 201 of the front apron 200.

[0041] Resulting from the localized fusion of the three sheets forming respectively the front apron 200, the front foot 530 and the main part 510 of the longitudinal member 510, these triple-thickness electric weld points P thus make it possible to obtain excellent mechanical strength of the front foot 530 in the event of a frontal impact.

[0042] As illustrated in this [Fig.1], the body underframe 1 also includes, in a conventional manner, two sheet metal apron reinforcements 210, 220 fixed by electric spot welding (ESW) against the upper face of the front apron 200, and arranged symmetrically on either side of the median longitudinal axis of this underframe 1.

[0043] With reference to [Fig.3], each apron reinforcement 210, 220 comprises a main longitudinal branch 221 and a secondary branch 222 extending obliquely backwards and outwards from the front free end of this main branch 221 to a lateral edge of the rear portion of the apron 200.

[0044] The distal rear end of this secondary branch 222 includes a vertical joining rebate 223 fixed via electrical spot welding (ESW) to a corresponding lateral joining rebate 201 of the front apron 200.

[0045] As illustrated by [Fig.4] and in order to prevent the weld points P from passing through it (which would result in an excessive weld thickness affecting the quality of the electrical weld points P), it will be noted that this vertical joining rebate 223 advantageously has notches 223A at the level of the implantation areas of these electrical weld bridges P.

Claims

Demands

1. Inner side member (400, 500) of underbody of motor vehicle body (1) comprising a main longitudinal U-section portion (420, 520) comprising a vertical internal lateral web (521) and two upper (522) and lower (523) flanges extending respectively from and along the upper and lower edges of this internal lateral web (521), said side member also comprising a front U-section foot (430, 530) surmounting the front portion of said main portion (420, 520) and comprising a vertical internal lateral web (531) and two front (532) and rear (533) flanges extending respectively from and along the front and rear edges of this internal lateral web (531),the lower rear portion of said front foot (530) flaring downwards to form an elbow, the free end of which (530A) corresponds in shape to cover a surface area of ​​the front portion of said main part (520); characterized in that the internal lateral web (521) of said main part (520) extends vertically and upwards, at the level of a front end section (520A) located in front of said surface area of ​​the cover, by a reinforcing protrusion (521A) fixedly pressed against the internal lateral web (531) of said front foot (530) by at least one electrical weld point (P).

2. Inner stringer (400, 500) according to claim 1, characterized in that said reinforcement protrusion (521A) is fixed to the inner lateral web (531) of said front foot (530) by means of at least two said longitudinally spaced electrical weld points (P).

3. Inner side member (400, 500) according to any one of claims 1 or 2, characterized in that said main part (520) and said front foot (530) are each obtained by stamping from a sheet of metal.

4. Inner stringer (400, 500) according to any one of claims 1 to 3, characterized in that said upper (522) and lower (523) flanges of said main part (520) extend opposite the inner lateral web (521) of this main part (520), respectively, by means of a folded upper joining rebate (524) vertically upwards and by a lower joining rebate (525) folded vertically downwards.

5. Inner stringer (400, 500) according to any one of claims 1 to 4, characterized in that said front end section (520A) of the main part (520) is devoid of top flange (522).

6. Inner side member (400, 500) according to any one of claims 1 to 5, characterized in that the front free end of said main part (520) is closed by a sheet metal closing piece (540) welded via joining rebates (541, 542) to the inner side web (521) and to the bottom flange (523) of this main part (520).

7. Body underbody (1) made of sheet metal for a motor vehicle, comprising a front floor (100) extending longitudinally between a front apron (200) and a rear floor (300), and transversely between two inner side members (400, 500); characterized in that said inner side members (400, 500) conform to any one of claims 1 to 6.

8. Body base (1) according to claim 7, characterized in that the inner lateral web (531) of the front foot (530) of each said inner longitudinal member (400, 500) is fixed to a corresponding lateral joining rebate (201) of said front apron (200).

9. Body base (1) according to claim 8, characterized in that each said electrical welding point (P) also passes through a said lateral joining rebate (210) of said front apron (200).

10. Motor vehicle comprising a body underbody according to any one of claims 7 to 9.