ASSISTED ASSEMBLY OF A MOTOR VEHICLE UNDERBODIES FLOOR

Abstract

A method allows the assembly of a motor vehicle underbody comprising a central floor with first longitudinal walls, right and left, extended by a first rebate, and a front block comprising two connecting pieces, right and left, fixedly attached to front frame members and each comprising a second longitudinal wall extended by a second rebate and to which a central longitudinal member is attached. This method includes a step (10-40) in which the central floor is brought substantially vertically and relatively closer to the connecting pieces by separating the second longitudinal walls from each other, until the first rebate is in contact with the second rebate, then the separation of the second longitudinal walls is stopped so that they respectively contact the corresponding first longitudinal walls. Figure 5

Description

Title of the invention: ASSISTED ASSEMBLY OF A MOTOR VEHICLE UNDERBODIES FLOOR Technical field of the invention

[0001] The invention relates to the underpinnings of motor vehicles, and in particular the assembly of such underpinnings. State of the art

[0002] Certain motor vehicles include a subframe comprising, in particular, a central floor (above which a passenger compartment is intended to be located) and a front section (intended to support, in particular, at least part of the powertrain). The central floor comprises first longitudinal walls (substantially vertical), right and left, extended by a first rebate (substantially horizontal). The front section comprises two connecting pieces, right and left, fixedly attached to front frame members, and each comprising a second longitudinal wall (substantially vertical) extended by a second rebate (substantially horizontal) and to which a central longitudinal member is attached.

[0003] The assembly of this type of substructure is generally carried out by vertically (relatively) bringing the central floor slab and the two connecting pieces together until the first rebate of the central floor slab contacts the second rebates of the connecting pieces, and the second longitudinal walls of the connecting pieces respectively contact the corresponding first longitudinal walls of the central floor slab. Once these contacts (or abutments) are achieved, the second rebates are welded to the first rebate and the second longitudinal walls to the first longitudinal walls.

[0004] Due to dimensional tolerances of the central floor and connecting pieces, and variations in the positioning of the connecting pieces on the front frame members, it frequently happens that the spacing between the second longitudinal walls of the connecting pieces is less than the spacing between the corresponding first longitudinal walls of the central floor. This prevents the central floor from being inserted between these second longitudinal walls, and consequently, the aforementioned correct alignment. It is then necessary to force the assembly to complete, which can lead to deformations of the second longitudinal walls and / or the first longitudinal walls and / or damage to the upholstery, or even to search for compatible front blocks and central flooring for a stress-free assembly. damage, which wastes time and therefore increases vehicle manufacturing costs.

[0005] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0006] In particular, it proposes for this purpose a method for assembling a base suitable for equipping a motor vehicle and comprising, on the one hand, a central floor having first longitudinal walls, right and left, extended by a first rebate, and, on the other hand, a front block having two connecting pieces, right and left, fixedly attached to front beams and each comprising a second longitudinal wall extended by a second rebate and to which a central longitudinal member is suitable for being attached.

[0007] This method is characterized by the fact that it includes a step in which the central floor of the connecting pieces is brought substantially vertically and relatively closer together by separating the second longitudinal walls from each other, until the first rebate is in contact with the second rebates, then the second longitudinal walls are no longer separated so that they respectively contact the corresponding first longitudinal walls.

[0008] Thanks to the invention, there is no longer a risk that the second longitudinal walls of the connecting pieces interfere with the relative translation of the corresponding first longitudinal walls of the central floor, and therefore there is no longer a risk of deformation of the second longitudinal walls and / or the first longitudinal walls and / or damage to the coating, or even of needing to search for compatible front block and central floor without spacing.

[0009] The method according to the invention may include other features which may be taken separately or in combination, and in particular:

[0010] - in its step, a robot comprising two arms, right and left, can be used, each equipped with an L-shaped rod to separate the second longitudinal walls from each other;

[0011] - in the presence of the first option, in its step, an endpoint can be introduced of each rod in a first corresponding through hole defined on one of the second rebates in order to allow the separation of the second longitudinal walls from each other, during the relative approach of the central floor of the connecting pieces;

[0012] - in the presence of the last sub-option, in its step, one can also introduce the end of each rod in a second corresponding through hole defined on the first rebate in order to allow contact between the first and second rebates during the separation of the second longitudinal walls from each other;

[0013] - in its stage, after the second longitudinal walls have contacted respectively the first corresponding longitudinal walls, the second rebates can be welded to the first rebate, at least in right and left longitudinal parts, and the second longitudinal walls to the first longitudinal walls.

[0014] The invention also provides a base, suitable for equipping a motor vehicle, and:

[0015] - comprising, on the one hand, a central floor having first walls longitudinal members, right and left, extended by a first rebate, and, on the other hand, a front block comprising two connecting pieces, right and left, fixedly attached to front beams and each comprising a second longitudinal wall extended by a second rebate and to which a central longeron is attached, and

[0016] - the first rebate being in contact with the second rebates, and the second walls longitudinals being in contact with the first corresponding longitudinal walls.

[0017] This base is characterized by the fact that the second rebates respectively include first through holes defined in first right and left sub-parts and suitable for receiving respectively the ends of two rods, equipping respectively two arms of a robot and suitable for acting respectively on these first right and left sub-parts to separate the second longitudinal walls from each other, during a phase of relative approach of the central floor of the connecting parts.

[0018] The base according to the invention may include other features which may be taken separately or in combination, and in particular:

[0019] - the first rebate includes second through holes defined in second sub-parts right and left and suitable to be crossed respectively by the ends of the two rods while allowing their translations during the approach phase;

[0020] - the second rebates can be welded to the first rebate at least in right and left longitudinal sections, and the second longitudinal walls can be welded to the corresponding first longitudinal walls;

[0021] - it may also include the two central longitudinal members, right and left, welded each to one of the right and left connecting pieces.

[0022] The invention also proposes a motor vehicle comprising a base of the type presented above.

[0023] For example, this motor vehicle may also include a rechargeable battery installed in a battery box fixedly attached to the underbody so that the central floor defines a cover protecting this battery. Brief description of the figures

[0024] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings (obtained using CAD / CAM (“Computer-Aided Design / Computer-Aided Manufacturing”)), in which:

[0025] [Fig-1] schematically illustrates, in a perspective view of the side of the face lower, part of an example of the realization of a chassis according to the invention of a motor vehicle, after assembly of some of its components by implementing an assembly process according to the invention, and before the installation of a battery tray,

[0026] [Fig.2] schematically illustrates, in a perspective view from above, the front block and central floor of the subframe of [Fig.1], before they are assembled together by implementing an assembly method according to the invention,

[0027] [Fig.3] schematically illustrates, in a perspective view from below, the left rod passing through the first through hole of the first sub-part of the left connecting piece of the front block of the [Fig.1] at the beginning of the spreading phase of the assembly method according to the invention,

[0028] [Fig.4] schematically illustrates, in a side perspective view, the left rod passing through the first and second through holes respectively of the first and second left sub-parts of the base of the [Fig.1] just before the end of the spreading phase of the assembly method according to the invention, and

[0029] [Fig.5] schematically illustrates an example of an algorithm implementing an assembly process according to the invention. Detailed description of the invention

[0030] The invention aims in particular to provide an SV underbody intended to equip a motor vehicle, and a method of assisted assembly of a part of such an SV underbody.

[0031] In what follows, a motor vehicle is considered, by way of non-limiting example, to be a car. However, the invention is not limited to this type of motor vehicle. It relates in fact to any motor vehicle comprising a chassis.

[0032] In Figures 1 to 4, the X direction is intended to be parallel to the longitudinal direction of the vehicle (automobile), which is substantially parallel to the lateral (or longitudinal) sides comprising the side doors; the Y direction is intended to be parallel to the transverse direction of the vehicle, which is perpendicular to the longitudinal direction X; and the Z direction is intended to be parallel to the vertical direction of the vehicle, which is perpendicular to the longitudinal X and transverse Y directions.

[0033] Figures 1 and 2 schematically illustrate at least partially an example of an SV underbody according to the invention, intended to equip a vehicle (automobile), once assembled by implementing at least one assembly method according to the invention.

[0034] As illustrated in Figures 1 and 2, a subframe SV, according to the invention, comprises at least one pre-assembled front BLV block, a central PC floor, and right (j = 1) and left (j = 2) central longitudinal members Lj.

[0035] The central floor PC comprises first longitudinal walls PLlj right (j = 1) and left (j = 2) which are extended by a first rebate Fl (here substantially perpendicular). These first longitudinal walls PLlj are intended here to be substantially vertical (vertical and longitudinal plane XZ), and the first rebate Fl is intended here to be substantially horizontal (horizontal plane XY).

[0036] It should be noted that the central floor PC also includes transverse walls PTj, right (j = 1) and left (j = 2), which are extended by the first rebate Fl and join the front or rear ends of the first longitudinal walls PLlj. It should also be noted that the central floor PC also includes an upper wall PS, which is extended downwards by the first longitudinal walls PLlj and transverse walls PTj, and which is here substantially contained in a horizontal plane XY. These transverse walls PTj are here intended to be substantially vertical (vertical and transverse plane YZ).

[0037] In the preceding and following text, the terms front and rear refer to the front and rear extremities of the underbody SV (and therefore of the vehicle). Consequently, the front of an element is closer to the front extremity of the underbody SV than to its rear extremity (SV), and the rear of an element is closer to the rear extremity of the underbody SV than to its front extremity (SV).

[0038] The front BLV block comprises two connecting pieces PDLj, right (j = 1) and left (j = 2), which are fixedly attached to front frame members BRVj, right (j = 1) and left (j = 2), and which each comprise a second longitudinal wall PL2j extended by a second rebate F2 (here substantially perpendicular), and to which a central longitudinal member LCj is attached. These second longitudinal walls PL2j are intended to be substantially vertical (vertical and longitudinal plane XZ), and the second rebates F2 are intended to be substantially horizontal (horizontal plane XY).

[0039] The assembly of the central floor PC to the connecting parts PDLj (and more generally to the front block BLV) is carried out by means of the implementation of the assembly process according to the invention.

[0040] As illustrated non-limitingly in [Fig.5], the (assembly) method according to the invention includes a step 10-40 which is implemented each time a central floor PC is to be fixedly attached to the connecting parts PDLj of a front BLV block (relatively).

[0041] Step 10-40 of the process includes a substep 10 in which the central floor PC of the connecting pieces PDLj is brought substantially vertically (along the vertical direction Z (arrow F0 of figures 2 and 3)) and relatively close together by moving the second longitudinal walls PL2j (arrow Fia) apart, until the first rebate Fl is in contact with the second rebates F2.

[0042] Step 10-40 of the process also includes a substep 20 in which the second longitudinal walls PL2j are no longer separated so that they respectively contact the corresponding first longitudinal walls PL1j.

[0043] By separating the second longitudinal walls PL2j from each other, there is no longer any risk that they (PL2j) will interfere with the relative translation (here vertical (arrow F0)) of the first longitudinal walls PL1j of the central floor PC. Consequently, there is no longer any risk of deformation of the second longitudinal walls PL2j and / or the first longitudinal walls PL1j and / or damage to the coating, or even the need to find compatible front BLV blocks and central floor PCs without damage. This avoids wasting time and increasing vehicle manufacturing costs.

[0044] It should be noted that the relative movement (arrow F0) of the central floor PC with respect to the connecting parts PDLj can be automated by means of a first robot (not shown) on an assembly line. However, it could be carried out by at least one operator (possibly assisted by an exoskeleton).

[0045] For example, in substep 10 of step 10-40, a second robot (not shown) can be used, comprising two arms, right and left, each equipped with an L-shaped rod TE (see Figures 3 and 4) to separate (arrow Fia) the second longitudinal walls PL2j of the connecting parts PDLj. It will be understood that in this case, the two arms of the second robot have opposing actions (here, pulls in opposite directions of the transverse Y direction). For example, the second robot can be arranged so that each of its arms can induce a separation of between 1 mm and 3 mm.

[0046] Also, for example, and as illustrated without limitation in Figures 3 and 4, each rod TE may include an end ET which is suitable for insertion into a corresponding first through hole TT1 defined on one of the second rebates F2. It will be understood that the second rebates F2 respectively include two first through holes TT1 defined respectively in first right and left sub-parts and suitable for receiving respectively the ends ET of the two rods TE. In this case, in sub-step 10 of step 10-40 one (for example the second robot) can introduce the ends ET of the two rods TE into the first through holes TT1 corresponding and defined on the second rebates F2 in order to allow the separation of the second longitudinal walls PL2j from each other, during the relative approach of the central floor PC of the connecting pieces PDLj.

[0047] Also, for example, and as illustrated non-limitingly in [Fig.4], the end ET of each rod TE can also be suitable for being inserted into a second through hole TT2 corresponding and defined on the first rebate Fl. It will be understood that the first rebate Fl comprises two second through holes TT2 defined respectively in second sub-parts right and left, intended to be placed under the first through holes TT1 corresponding of the second rebates F2, and suitable for receiving respectively a part of the ends ET of the two rods TE.In this case, in substep 10 of step 10-40, one (for example, the second robot) can introduce the ends ET of the two rods TE not only into the corresponding first through holes TT1, but also into the corresponding second through holes TT2 in order to allow contact between the first Fl and second F2 rebates during the separation of the second longitudinal walls PL2j.

[0048] It will be understood that thanks to these second through holes TT2 defined in the first rebate Fl where the ends ET of the rods TE are to be positioned, the relative translation of the central floor PC towards the connecting pieces PDLj (arrow F0) is not interrupted by the temporary presence of the ends ET of the rods TE, and therefore in substep 10 the first rebate Fl of the central floor PC can come into contact with the corresponding second rebates F2 of the connecting pieces PDLj.

[0049] It will also be understood that the cessation of the separation carried out in substep 20 results here from an action of the two arms of the second robot in opposite directions to the previous ones (i.e., oriented towards each other) in order to allow the respective contacts between the second longitudinal walls PL2j and the first longitudinal walls PL1j, followed by a separation of the two arms from the front block BLV. It should be noted that the bringing together of the second longitudinal walls PL2j requires here that at least the extension of each second hole passing through TT2 along the transverse direction Y be strictly greater than the extension of each first hole passing through TT1 along the transverse direction Y, because it is necessary to allow the ends ET of the two rods TE to translate (here along the transverse direction Y) respectively into the second holes passing through TT2 during the bringing together phase.

[0050] For example, when the extensions along the longitudinal X and transverse Y directions of each first hole through TT1 are approximately equal to 24 mm and 24 mm respectively, the extensions along the longitudinal X and transverse Y directions of each second hole through TT2 can be approximately equal to 28 mm and 34 mm respectively.

[0051] Also, for example, and as illustrated non-limitingly in [Fig.5], step 10-40 may also include a substep 30 in which, after the second longitudinal walls PL2j have respectively contacted the corresponding first longitudinal walls PL1j, the second rebates F2 can be welded to the first rebate Fl, at least in right and left longitudinal parts, and the second longitudinal walls PL2j to the first longitudinal walls PL1j.

[0052] Also, for example, and as illustrated non-limitingly in [Fig. 5], step 10-40 may also include a substep 40 in which, after the welding carried out in substep 30, the two central longitudinal members LCj, right (j = 1) and left (j = 2), can be welded respectively to the connecting pieces PDLj right and left (and preferably to their second longitudinal walls PL2j and their second rebates F2), so as to reinforce the strength of the underbody SV. These central longitudinal members LCj are illustrated in [Fig. 1].

[0053] It should also be noted, although not shown in Figures 1 to 4, that the SV underbody can subsequently accommodate, beneath its central floor PC, a battery tray housing a rechargeable battery with its control electronics. In this case, the central floor PC acts as a protective cover for the battery tray, and the battery tray, the rechargeable battery with its control electronics, and the central floor PC constitute a battery assembly (or pack). This cover thus protects at least the rechargeable battery.

[0054] Preferably, the battery tray is fixedly secured by screwing to the first rebate Fl of the central floor PC.

[0055] Also, for example, the rechargeable battery may include at least one cell module comprising at least two electrical energy storage cells. Here, "electrical energy storage cell" means a rechargeable cell and possibly an electrochemical cell (for example, of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type).

Claims

Demands

1. Method of assembling a subframe (SV) suitable for equipping a motor vehicle and comprising i) a central floor (PC) having first longitudinal walls (PL1j), right and left, extended by a first rebate (F1), and ii) a front block (BLV) having two connecting pieces (PDLj), right and left, fixedly attached to front frame members (BRVj) and each comprising a second longitudinal wall (PL2j) extended by a second rebate (F2) and to which a central longitudinal member (LCj) is suitable for being attached, characterized in that it comprises a step (10-40) in which said central floor (PC) is brought substantially vertically and relatively closer to said connecting pieces (PDLj) by separating said second longitudinal walls (PL2j) from each other, until said first rebate (F1) is in contact with said second rebates (F2),then we cease to separate the said second longitudinal walls (PL2j) so that they respectively contact the corresponding said first longitudinal walls (PL1j).

2. Method according to claim 1, characterized in that in said step (10-40) a robot comprising two arms, right and left, each equipped with an L-shaped rod (TE) to separate said second longitudinal walls (PL2j) from each other.

3. Method according to claim 2, characterized in that in said step (10-40) one end (ET) of each rod (TE) is introduced into a first corresponding through hole (TT1) defined on one of said second rebates (F2) in order to allow the separation of said second longitudinal walls (PL2j) from each other, during the relative approach of said central floor (PC) of said connecting pieces (PDLj).

4. Method according to claim 3, characterized in that in said step (10-40) said end (ET) of each rod (TE) is introduced into a second through hole (TT2) corresponding and defined on said first rebate (Fl) in order to permit said contact between said first (Fl) and second (F2) rebates during said separation of said second longitudinal walls (PL2j) from each other.

5. A method according to any one of claims 1 to 4, characterized in that in said step (10-40), after said second longitudinal walls (PL2j) have respectively contacted said corresponding first longitudinal walls (PL1j), said second rebates (F2) are welded to said first rebate (F1), at least in right and left longitudinal parts, and said second longitudinal walls (PL2j) to said first longitudinal walls (PL1j).

6. Underbody (SV) suitable for equipping a motor vehicle and comprising i) a central floor (PC) having first longitudinal walls (PL1j), right and left, extended by a first rebate (F1), and ii) a front block (BLV) having two connecting pieces (PDLj), right and left, fixedly attached to front frame members (BRVj) and each comprising a second longitudinal wall (PL2j) extended by a second rebate (F2) and to which a central longitudinal member (LCj) is suitable for being attached, said first rebate (F1) being in contact with said second rebates (F2) and said second longitudinal walls (PL2j) being in contact with said corresponding first longitudinal walls (PL1j),characterized in that said second rebates (F2) respectively comprise first through holes (TT1) defined in first right and left sub-parts and adapted to receive respectively the ends (ET) of two rods (TE), respectively equipping two arms of a robot and adapted to act respectively on said first right and left sub-parts to separate said second longitudinal walls (PL2j) from each other, during a phase of relative rapprochement of said central floor (PC) of said connecting parts (PDLj).

7. Base according to claim 6, characterized in that said first rebate (Fl) comprises second through holes (TT2) defined in second right and left sub-parts and adapted to be traversed respectively by said ends (ET) of the two rods (TE) while allowing their translations during said approach phase.

8. Base according to claim 6 or 7, characterized in that said second rebates (F2) are welded to said first rebate (Fl) at least in right and left longitudinal parts, and said second longitudinal walls (PL2j) 11 are welded to the corresponding first longitudinal walls (PLlj).

9. Motor vehicle, characterized in that it comprises a subframe (SV) according to any one of claims 6 to 8.

10. Vehicle according to claim 9, characterized in that it comprises a rechargeable battery installed in a battery tray fixedly attached to said underbody (SV) so that said central floor (PC) defines a cover protecting said battery.

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