SCREWLESS ASSEMBLY METHOD BETWEEN THE UNDERBody AND SUPERSTRUCTURE OF A VEHICLE BODY

Abstract

The invention relates to a method of joining at least one rear wheel arch (1) and at least one rear seat latch reinforcement (2) of the vehicle, characterized in that it comprises the following steps: a) welding a connecting piece to a rear wheel arch (1), said piece being fixed on one side only and having one degree of rotational freedom; b) positioning the superstructure above the underbody by resting a rear seat latch reinforcement (2) on at least one free side of the connecting piece; c) welding the rear seat latch reinforcement (2) to the connecting piece attached in step a); d) welding a reinforcement piece for a rear seat latch wire support (15) to the connecting piece attached in step a) and to the rear seat latch reinforcement (2). The invention also relates to a vehicle assembled according to such a method.Figure to be published with the abbreviation: Fig. 2.

Description

Title of the invention: METHOD FOR SCREWLESS ASSEMBLY BETWEEN THE UNDERBody AND SUPERSTRUCTURE OF A VEHICLE BODY

[0001] The invention relates to a method of screwless assembly between the underbody and the superstructure of a vehicle body.

[0002] Here the term vehicle refers to a car, a van, a truck, a public transport vehicle, a piece of public works or agricultural machinery, regardless of the type of engine, thermal, hybrid or electric.

[0003] As a reminder, the body superstructure refers to the upper part of a vehicle's body, and the underbody forms the lower part. During the assembly process known as body fitting, after certain components have been placed on the underbody, the latter is permanently and securely connected to the body superstructure before other equipment is installed inside the vehicle body. To achieve this, a connection must be made between these two sub-assemblies that meets the dynamic and static stiffness requirements of the assembly and ensures a fit within the tolerance ranges. In particular, the tolerance ranges must be respected when connecting the underbody at the rear wheel arch to the rear seat latch reinforcement, this reinforcement being fixed to the superstructure.To achieve such an assembly, it is known to use screw connections and / or add-on connecting parts with a given geometric configuration in order to adjust the tolerance of the connection between the elements to be assembled. Such solutions are relatively complex to implement due to the geometric constraints that impose a loading angle when the elements are screwed together. FR-B-3 102 437 describes a connection between a rear wheel arch and a seat belt retractor comprising an elongated part with at least one mounting hole for the retractor and reinforcing ribs, and having an external edge intended to be welded to a portion of the wheel arch. This solution is specifically designed for attaching a seat belt retractor to the rear wheel arch. It does not allow for optimizing the connection between the underbody and the superstructure while respecting tolerance intervals.Therefore, there is a need for an assembly process that respects tolerance intervals while limiting costs.

[0004] The invention aims to provide an assembly solution between the underbody and the superstructure of a vehicle body without geometric constraints imposing a loading angle and respecting the constraints of dynamic stiffness and static while reducing the associated costs.

[0005] To this end, the invention relates to an assembly method called "ferrage" between the underbody and the superstructure of the body of a vehicle, said assembly taking place between at least one rear wheel arch and at least one reinforcement for fixing the latch of a rear seat of the vehicle, characterized in that it comprises at least the following steps: a) to fix by welding at least one connecting piece to one face of at least one rear wheel arch, said piece being fixed on one of its sides and having at least one degree of rotational freedom around an axis of rotation materialized by the fixing line of the side of the connecting piece on the rear wheel arch equipped with a reinforcement piece of a latch wire support, b) to position the superstructure above the underbody by resting a rear seat latch fixing reinforcement on at least one free side of the connecting piece fixed in step a) and on the reinforcement piece of a latch wire support, respecting the rotational tolerance intervals of said connecting piece around its axis of rotation, c) weld the rear seat latch fixing reinforcement to the connecting piece fixed in step a), d) to fix by welding a reinforcement piece of a rear seat latch wire support on one side to the connecting piece fixed in step a) and on the other side to the rear seat latch fixing reinforcement.

[0006] Thus, thanks to the invention, without screwing and solely by welding, the bodywork of a vehicle is ensured while respecting the constraints due to the assembly process and the tolerance intervals thanks to the rotational degree of freedom of the connecting part, which allows for precise positioning of the elements to be assembled. The invention makes it possible to overcome the geometric constraints imposing a loading angle when positioning the superstructure above the underbody. According to the invention, it is possible, by welding in double or triple thickness depending on the welded areas, to create a load path in all directions when the bodywork of the superstructure is attached to the underbody. Such an operation makes it possible to limit costs compared to screwing operations, while being quick and easily automated.

[0007] According to advantageous but not mandatory aspects of the invention, such an assembly method may comprise one or more of the following steps:

[0008] The step of fixing by welding the reinforcement piece of a wire support of a latch is carried out before the step of fixing the connecting piece to the latch fixing reinforcement of the rear seat.

[0009] During step a), the attachment is achieved by at least two weld points between a tab oriented angularly with respect to the main body of the connecting part and one side of the rear wheel arch.

[0010] During step c) the fixing is achieved by at least two weld points between an edge oriented angularly with respect to the main body of the connecting piece and an edge of the rear seat latch fixing reinforcement.

[0011] During step c) the fixing is achieved by four weld points between an edge oriented angularly with respect to the main body of the connecting piece and an edge of the rear seat latch fixing reinforcement.

[0012] During step d), the fixing is achieved by at least one weld point between the reinforcement piece of a rear seat latch wire support and a folded edge of the main body of the connecting piece.

[0013] During step d), the fixing is achieved by two weld points between the reinforcement piece of a wire support for the rear seat latch and a folded edge of the main body of the connecting piece.

[0014] During step a), the reinforcement piece of a wire support for a strike plate is welded onto a piece attached to the rear wheel arch.

[0015] During step a), the reinforcement piece of a wire support for a strike plate is one piece with a piece attached to the rear wheel arch.

[0016] During step d), the fixing is achieved by at least one weld point between a free end of the reinforcement piece of a wire support for the rear seat latch and, on the one hand, a folded edge of the main body of the connecting piece and, on the other hand, a lateral area of ​​a relief provided on the edge of the rear seat latch fixing reinforcement.

[0017] The invention also relates to a vehicle whose shoeing is carried out according to a process conforming to at least one of the preceding steps.

[0018] The invention will be better understood and other advantages thereof will become more apparent upon reading the following description, given solely by way of non-limiting example and with reference to the accompanying drawings in which:

[0019] [Fig-1] is a partial perspective view of a so-called "ferrage" assembly between the underbody and the superstructure of the body of a vehicle at the level of a rear wheel arch and a reinforcement for fixing a latch of a rear seat of the vehicle according to a method in accordance with an embodiment of the invention,

[0020] [Fig.2] is a perspective view from another angle, partial and on a larger scale of the assembly of [Fig.1], only the rear wheel arch and the latch fixing reinforcement of a rear seat of the vehicle being illustrated,

[0021] [Fig.3] is a view similar to [Fig.2], at a different scale, illustrating the freedom of rotation of the single connecting piece put in place in step a) of the process illustrated in Figures 1 and 2 and

[0022] [Fig.4] is a perspective view, at a different scale and from a different angle, of the posi assembly of the superstructure above the substructure, in accordance with step b) of the assembly process which is the subject of the invention.

[0023] Figure 1 illustrates the superstructure of a vehicle in place on the underbody, following the assembly operation, referred to as "seat fitting," according to one embodiment of the invention. Only the parts of the underbody and superstructure of the vehicle relevant to the invention are shown here. This is a rear wheel arch 1 of a vehicle to which a reinforcement for the mounting of a rear seat 2 is attached. The term "reinforcement for the mounting of the rear seat 2" will also be used hereafter for ease of reading. It is understood that the invention relates equally to both rear wheel arches and the two reinforcements for the mounting of the rear seat 2s of the vehicle.As a reminder, the rear seat latch mounting reinforcement 2 is a metal part that permanently attaches the rear seat latch to a section of the vehicle's body structure. The latch is the mechanism located primarily in the seat backrest that holds it in position, in a removable manner, when the seat backrest is in its usable configuration, i.e., when the seat is ready to accommodate a seated passenger. A U-shaped latch wire 3, to which part of the latch mechanism is removablely attached, is welded to the latch reinforcement 2. The latch wire 3 is positioned near a free edge 4 of the latch reinforcement 2. This edge 4 is the one located closest to the rear wheel arch 1 when the metalwork is complete.

[0024] The rear wheel arch 1 comprises, in its upper part when viewed from [Fig. 1], a generally flat face 5 oriented towards the latch reinforcement 2. The face 5 is generally parallel to a principal plane P of the underbody 6, a part of which is visible in Figures 1 and 4. A connecting piece 7, particularly visible in [Fig. 3], provides the connection between the face 5 of the rear wheel arch 1 and the edge 4 of the latch reinforcement 2.

[0025] The connecting piece 7, which is metallic, is substantially rectangular in shape. Alternatively, it may be of a different shape, for example, square. The connecting piece 7 comprises a rectangular central body 8 bordered, on one of its edges defining the lengths, by a tab 9 arranged angularly with respect to the principal plane P8 of the body 8 and extending towards the front of the vehicle. The tab 9 is also rectangular but smaller than the body 8. The opposite edge 10 of the body 8 is also oriented angularly with respect to the plane P8 of the central body 8. The edge 10 of the connecting piece 7 has a geometric configuration complementary to that of the edge 4 of the strike plate reinforcement 2. Here, the edge 10 includes a cutout 11 whose shape and dimensions correspond to those of a relief 12 formed on the edge 4 of the strike plate reinforcement 2.

[0026] The connecting piece 7 includes a folded edge 13 formed by folding an edge of the body central 8 defining its width and edge 10 extending said edge of the body 8. Edge 13 is substantially bent at 90° and includes a cutout 14. It thus defines a bearing surface oriented angularly with respect to the body 8 and with respect to the leg 9 and the edge 10, this with different angles.

[0027] A reinforcement piece for the wire support of the latch 15, hereafter referred to as the "reinforcement piece" for ease of reading, is permanently fixed to the rear wheel arch 1.

[0028] As shown in Figures 1, 2, and 4, the reinforcing piece 15 extends upwards when viewed from Figures 1, 2, and 4. It is fixed to a lateral face 16 of the rear wheel arch 1. Face 16 is oriented towards the interior of the vehicle body. The reinforcing piece 15 is a flat tab, generally triangular in shape. It extends outwards from face 16 above face 5 of the rear wheel arch 1. Hereafter, the terms "reinforcing piece" and "reinforcing tab" will be used interchangeably. In one embodiment, the reinforcing tab 15 is attached and fixed by welding to the face 16. Alternatively, the reinforcing tab 15 is a single piece with a part 17 which is fixed to the face 16. The reinforcing part 15, when the assembly is completed, rests on, on the one hand, the folded edge 13 of the connecting part 7 and, on the other hand, on a lateral area 22 of the relief 12 of the edge 4 of the strike plate reinforcement 2.The reinforcing tab 15, once welded onto the relief 12 and the edge 13, ensures locking in position and reinforces the holding in position of the various linked parts.

[0029] As illustrated in [Fig. 2], all connections between the various parts are made by welding, advantageously in an automated manner. The tab 9 is welded by at least one spot weld 18, preferably by two spot welds 18, to the flat face 5 of the rear wheel arch 1. The edge 10 of the connecting piece 7 is welded to the edge 4 of the strike plate reinforcement 2 by at least two spot welds 19, advantageously by four spot welds 19. At least one spot weld 20, preferably two spot welds 20, provides the connection between a portion of the reinforcement piece 15 and the edge 13 of the connecting piece 7. In all cases, the spot welds 18, 19, and 20 are double-thickness welds.At least one weld point 21 made on a free end of the reinforcing piece 15 allows this end to be secured, on the one hand, to an area of ​​the folded edge 13 and, on the other hand, to the lateral area 22 of the relief 12 of the strike plate reinforcement 2. Such double and triple thickness welded connections between several parts of the underbody and superstructure make it possible to create a load path in three orthogonal directions, thus guaranteeing the stiffness and strength of the connection between the rear wheel arch 1 and the strike plate reinforcement 2. The use of only welded connections makes it possible to reduce assembly costs.

[0030] The method of fitting between the rear wheel arch 1 and the fixing reinforcement of The latch of a rear seat 2 is now described with reference in particular to Figures 3 and 4. This assembly method makes it possible to obtain the connections between the various elements 1, 2, 7, and 15 as described previously. The first step consists of placing the tab 9 of the connecting piece 7 on the face 5 of the wheel arch 1. This creates a support between two flat areas. The tab 9 is held in place on the face 5 by at least two weld points 18. The fact that the connecting piece 7 is fixed to the face 5 only by the tab 9, which is positioned angularly with respect to the body 8 and the opposite edge 10, defines an axis of rotation A, represented by a straight line connecting the weld points 18. This allows a certain degree of rotational freedom of the connecting piece 7, as indicated by the double arrow F, around this axis A.

[0031] Such freedom of rotation, even if limited, allows, in a second step, for the edge 10 to be positioned correctly in relation to the edge 4 of the strike plate reinforcement 2, respecting the tolerance intervals when fitting the superstructure to the base, as illustrated in [Fig.4]. It should be noted that, because the connecting piece 7 and the reinforcing piece 15 are each positioned on, respectively, the face 5 and the face 16 of the rear wheel arch 1, the superstructure can easily be placed above the underbody by playing on the degree of freedom of the connecting piece 7 and by bringing the latch reinforcement 2 against the reinforcing piece 15. At the end of this step, the edge 10 of the connecting piece 7 is in contact with the edge 4 of the latch reinforcement 2 and the reinforcing piece 15 is in contact with the folded edge 13 of the connecting piece 7 and, by its free end, in contact with the edge 22 of the relief 12 of the latch reinforcement 2.Thus, the reinforcement of the strike plate 2 is positioned and locked in position on the rear wheel arch 1.

[0032] It is then necessary to secure these supports by welding parts 7 and 15 onto the strike plate reinforcement 2. First, for example, the edge 10 of the connecting part 7 is welded to the edge 4 of the strike plate reinforcement 2, then the reinforcement part 15 is welded to the edge 13 of the connecting part 7 and to the edge 22 of the relief 12 of the strike plate reinforcement 2. Thus, the double-thickness welds are made first, and then the triple-thickness weld is made between the edges 13, 22 and 15. Alternatively, the order of the welds is reversed, with the triple-thickness weld being made first.

[0033] In all cases, thanks to the invention, the fitting between the superstructure and the underbody of a vehicle is facilitated by creating, in a simple way and at a reduced cost, a load path in all directions, which makes it possible to comply with the stiffness constraints of such fitting.

Claims

Claims

1. Assembly method called fitting between the underbody and the superstructure of the body of a vehicle, said assembly taking place between at least one rear wheel arch (1) and at least one striker fixing reinforcement of a rear seat (2) of the vehicle, characterized in that it comprises at least the following steps: - a) fixing by welding (18) at least one connecting piece (7) on a face (5) of at least one rear wheel arch (1), said piece (7) being fixed by only one (9) of its sides and having at least one degree of freedom in rotation (F) around an axis of rotation (A) materialized by the fixing line of the side (9) of the connecting piece (7) on the rear wheel arch (1) equipped with a piece reinforcing a striker wire support (15),- b) positioning the superstructure above the underbody by resting a rear seat striker fixing reinforcement (2) on at least one free side (10) of the connecting piece (7) fixed in step a) and on the reinforcing piece of a striker wire support (15) while respecting the rotation tolerance intervals (F) of said connecting piece (7) around its axis of rotation (A), - c) fixing by welding (19) the rear seat striker fixing reinforcement (2) to the connecting piece (7) fixed in step a), - d) fixing by welding (20, 21) a reinforcing piece of a rear seat striker wire support (15) on the one hand to the connecting piece (7) fixed in step a) and on the other hand to the rear seat striker fixing reinforcement (2).,

2. Method according to claim 1, characterized in that the step of fixing by welding (20, 21) the reinforcement part of a striker wire support (15) is carried out before the step of fixing the connecting part (7) to the striker fixing reinforcement of the rear seat (2).

3. Method according to claim 1, characterized in that during step a), the fixing is carried out by at least two welding points (18) between a tab (9) oriented angularly relative to the main body (8) of the connecting piece (7) and a face (5) of the rear wheel arch (1).

4. Method according to claim 1, characterized in that during step c) the fixing is carried out by at least two welding points (19) between an edge (10) oriented angularly relative to the main body (8) of the connecting part (7) and an edge (4) of the rear seat striker fixing reinforcement (2).

5. Method according to claim 4, characterized in that during step c) the fixing is carried out by four welding points (19) between an edge (10) oriented angularly relative to the main body (8) of the connecting piece and an edge (4) of the rear seat striker fixing reinforcement (2).

6. Method according to claim 1, characterized in that during step d), the fixing is carried out by at least one welding point (20) between the reinforcing part of a rear seat striker wire support (15) and a folded edge (13) of the main body (8) of the connecting part (7).

7. Method according to claim 6, characterized in that during step d), the fixing is carried out by two welding points (20) between the reinforcing part of a rear seat striker wire support (15) and a folded edge (13) of the main body (8) of the connecting part (7).

8. Method according to claim 1, characterized in that during step a), the reinforcing part of a striker wire support (15) is in one piece with a part (17) secured to the rear wheel arch (1).

9. Method according to one of claims 6 or 7, characterized in that during step d), the fixing is carried out by at least one welding point (21) between a free end of the reinforcing part of a rear seat striker wire support (15) and, on the one hand, a folded edge (13) of the main body (8) of the connecting part (7) and, on the other hand, a lateral zone (22) of a relief (12) provided on the edge (4) of the rear seat striker fixing reinforcement (2).

10. The invention also relates to a vehicle whose fitting is carried out according to a method in accordance with at least one of the preceding steps.

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