FR3005297A1 - METHOD FOR ASSEMBLING BODYWORK ELEMENTS WITH USE OF A BILGE DURING THERMAL TREATMENTS - Google Patents

Abstract

The manufacture of a motor vehicle sub-assembly comprises a pre-assembly of a first body element (11) on a second body element (12) in an initial position offset from a final position in one direction ( D) corresponding to the thickness of the first body member (11), a heat treatment applied to the first and second body members (11, 12) during which the first body member (11) is in its initial position so as not to be in the extension of the second bodywork element (12) and to avoid any contact between the first and second bodywork elements (11, 12) under the effect of a thermal expansion of the first bodywork element (11) during said at least one heat treatment step. The pre-assembly provides for placing a shim (100) between the first body member (11) and a support (10) so that the initial position corresponds to an elevated position in the direction (D) corresponding to the thickness of the first body element (11), with respect to the final position, on the opposite side of the support (10).

Description

TECHNICAL FIELD OF THE INVENTION The invention relates to the field of manufacturing a subassembly of a motor vehicle comprising a support belonging to the body. of the vehicle, a first bodywork element, in particular a front lateral wing, mounted on the support and a second bodywork element, in particular a baystand, the first and second bodywork elements occupying at the end of the manufacture of the end positions. respective in which they are side by side and in the extension of each other with interposition of a functional game. The subject of the invention is more particularly such a manufacturing method, a wedge configured so as to implement the manufacturing method, a subassembly of a motor vehicle obtained by implementing the manufacturing method and a motor vehicle comprising at least one such subset. State of the art conventionally, the front side wing and the amount of bay of the bodywork of a motor vehicle occupy, at the end of the manufacture of the vehicle, the respective end positions in which they are side by side and in the extension of one another, with the interposition of a functional assembly game.

During the manufacture of a motor vehicle subassembly comprising a carrier belonging to the vehicle body, the front side wing mounted on the carrier and the bay post, the front side wing and the bay post undergo one or several stages of heat treatment, for example during the entire painting application process, such as the operation of cataphoresis and application of putty or varnish.

The value of the functional assembly game between the lateral front wing and the amount of rack must be sufficient to overcome the risk of contact between these two body parts during heat treatments. Otherwise, a thermal expansion of the lateral front wing during the heat treatments causes a contact during heat treatments, between the front side wing and the amount of bay. This is unsatisfactory, especially since irreversible damage may occur. The use of a lateral front wing and / or a jamb amount of metal material such as aluminum makes it possible to provide a relatively low value of the functional clearance, of the order of 2 mm, which gives a satisfaction aesthetics of the subset at the end of manufacturing. Indeed, such a material has a coefficient of thermal expansion to overcome the risk of contact between the front side wing and the bay amount despite the low value of the functional game. The problem arises from the increased use of plastics for the constitution of the body elements, in particular the front side wings. These materials, which also have certain advantages in terms of weight, manufacturing, safety, have a coefficient of thermal expansion less favorable. This results in a frequent requirement of a higher mounting functional clearance in the case of body elements made of such plastics than in the case of bodywork elements made of metallic materials, for example of the order of 4 mm. . But such relatively high functional assembly play is likely to cause aesthetic inconvenience to the finished body. These problems are not limited to the areas of outcropping between the front lateral wings and the uprights of bay but can affect on the contrary all subassemblies of motor vehicle where two body elements are side-by-side at the end of the manufacture of the subset. OBJECT OF THE INVENTION The object of the present invention is to propose a manufacturing solution that overcomes the disadvantages listed above. In particular, an object of the invention is to provide such a solution that allows the use of plastic body elements while providing a low assembly functional play and at the same time free from risks of deterioration during manufacturing, in particular by contact between the body components during heat treatments.

This object can be achieved by a method of manufacturing a subassembly of a motor vehicle comprising a support belonging to the body of the vehicle, a first body element, in particular a front lateral wing, mounted on the support and a second element of the body. bodywork, in particular an amount of bay, the first and second body elements occupying at the end of the process the respective end positions in which they are side by side and in the extension of one another, the method comprising a step of pre-mounting the first body member on the second body member in an initial position offset from its final position in a direction corresponding to the thickness of the first body part, then at least one step heat treatment applied to the first and second body members during which the first body element occupies its position initial ion so as not to be in the extension of the second bodywork element and to avoid any contact between the first and second bodywork elements under the effect of a thermal expansion of the first bodywork element during said at least one step of heat treatment, - the pre-assembly step comprising a step of placing a wedge between the first body member and the support so that the initial position corresponds to a raised position in the direction corresponding to the thickness of the first body element, with respect to the final position, on the opposite side of the support.

The location occupied by the shim following said placing step is preferably located in the flush zone between the first and second body members when in their final positions.

The step of placing the wedge may comprise a step of reversibly holding the wedge on the first body member with a step of fixing, on the second body member, the assembly comprising the first body member and the hold held on the first body member.30 The holding step may comprise a reversible wedging step by form conjugation between first positioning elements integral with the shim and second positioning elements integral with the first body member.

The holding step may comprise a reversible clipping step of the shim on a first fastening element, in particular a screw, used during said fixing step and ensuring the attachment of the first bodywork element to the second bodywork element.

Following said at least one heat treatment step, the method may comprise a step of removing the shim between the second bodywork element and the first bodywork element, said removal step comprising a step of applying a force of manual traction on the hold at a gripping element secured to the hold and accessible from outside the subassembly. The shim is preferably configured so that said step of applying force automatically causes the suppression of the wedging by form conjugation between first positioning elements integral with the shim and second positioning elements integral with the first body member and / or the removal of the snap between the shim and the first fixing element.

Following the removal step, the method may comprise a step of positioning the shim between the support and a pre-mounted reinforcement element on the first bodywork element and arranged between the support and the first bodywork element and reinforcing the first element of bodywork against external shocks, the location occupied by the shim with respect to the first bodywork element following said positioning step being different from that occupied following said implementation step. Said positioning step preferably comprises a step 5 of actuation, in particular by loosening, of a second fastening element, in particular a screw, making a local and reversible embedment connection between the shim, the first bodywork element, and the support . The actuating step may comprise a step of contacting the wedge with an angular locking element formed in the reinforcing element in such a manner that the reinforcing element suppresses the degree of rotational freedom of the reinforcement element. the wedge around the screw axis of a screw constituting the second fixing element during said actuating step. A second aspect relates to a shim configured to implement the manufacturing method defined above. A third aspect relates to a motor vehicle subassembly, comprising a carrier belonging to the vehicle body, at least a first plastic body member, in particular a front side wing mounted on the carrier and a second body member. , in particular an amount of bay, obtained by the implementation of the manufacturing method, in which a lower functional clearance of 3 mm is interposed between the first and second bodywork elements in their final positions. A fourth aspect relates to a motor vehicle comprising at least one such subset. Other advantages and features will emerge more clearly from the following description of particular embodiments of the invention given by way of nonlimiting example and represented in the accompanying drawings, in which: FIG. 1 is a perspective view of an example of a subassembly obtained by the implementation of an exemplary manufacturing method according to the invention; FIG. 2 illustrates the subassembly of FIG. section of the flush zone between the two bodywork elements, according to the section plane AA visible in FIG. 1; FIGS. 3 and 4 are views identical to FIGS. 1 and 2 respectively, but during the implementation of FIG. manufacturing method, at the end of the pre-assembly step of the first bodywork element in the initial position and at the end of the step of mounting the second bodywork element in the final position, - the figures 5 and 6 illustrate the result of a step of applying paint layers on the bodywork elements, respectively in the conditions of FIG. 3 and FIG. 1; FIG. 7 represents positioning elements integral with the first bodywork element; FIG. 8 illustrates the situation of holding the shim on the first bodywork element before the latter is mounted on the support; FIGS. 9 and 11 illustrate the situation when the shim is positioned between the support; and a reinforcing member interposed between the support and the first body member, - Figure 10 illustrates the mounting position of the shim on the reinforcing element, - and Figures 12 and 13 are views respectively in perspective and of side of the wedge used in the process illustrated in Figures 1 to 11.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION The description which follows is made with reference to an orthonormal reference (X, Y, Z) conventionally associated with a motor vehicle, in which X is the longitudinal longitudinal direction of the front-rear of the vehicle, Y is the right-to-left transverse direction which is horizontal and perpendicular to X, and Z is the vertical direction jointly perpendicular to the X and Y directions. In general, the invention relates firstly to a method of manufacturing a subassembly motor vehicle comprising a support 10 belonging to the body (also called chassis) of the vehicle, a first body member 11 mounted on the support 10 (Figure 3) and a second body member 12, this method being such that the first and second body elements 11, 12 occupy at the end of the process respective final positions in which they are side by side and in the prolonged from each other. In other words, they are flush against each other in height at their adjacent sides, with the interposition of a functional game noted j (Figure 2) between them. The invention also relates to a shim 100 configured so as to implement the manufacturing method. An object of the invention is to provide a low value, preferably less than 3 mm, despite the use of a first body member 11 of plastic.

It also relates to a subassembly, in which at least the first body element 11 is made of plastic, which is obtained by the implementation of the manufacturing method and in which a functional clearance of less than 3 mm is interposed. between the first and second body members 11, 12 in their final positions. Finally, it relates to a motor vehicle comprising at least one such subassembly. The accompanying figures illustrate the particular case of a first body member 11 consisting of a front side wing and a second body member consisting of a bay jamb. However, the scope of the solution described below may be extended to any bodywork element. Figures 1 and 2 show the situation of the first and second body members 11, 12 when each of them occupies its final position.

In its final position, the first body member 11 is fixedly mounted on the second body member 12. The first and second body members 11, 12 arranged side by side have two adjacent edges separated from each other by the functional clearance j. Their final positions are determined so as to be in line with each other, that is to say that the height shift in a direction D (FIG. 2) corresponding to the thickness of the first element of bodywork 11, is zero or as low as possible. According to an important characteristic, the manufacturing method 25 comprises: - a step of pre-assembly of the first bodywork element 11 on the second bodywork element 12 in a temporary initial position (FIGS. 3 and 4) offset with respect to its final position along the direction D, 30 - then at least one heat treatment step applied to the first and second body members 11, 12 during which the first body member 11 is in its initial position so as not to be an extension of the second element of the body. body 12 and avoid contact between the first and second body members 11, 12 under the effect of thermal expansion of the first body member 11 during said at least one heat treatment step. In other words, the first bodywork element 11, here the front lateral wing, and the second bodywork element 12, here the rack amount, undergo one or more heat treatment steps, for example during the complete process of application of painting, such as the operation of cataphoresis and application of putty or varnish. During said at least one heat treatment step, the first bodywork element is offset in height with respect to the final position that it will occupy at the end of the process. This offset in height denoted H along the direction D is represented in FIG. 4, in the particular case of an upward shift, that is to say on the opposite side of the support 10, so that the first element of body is elevated relative to the second body member 12.

Depending on the nature of the heat treatments, prior to said at least one heat treatment step, the method preferably comprises a step of mounting the second body member 12 on an element belonging to the body, potentially the support 10, so as to occupy its final position and maintain it during said at least one heat treatment step. In this particular mode of implementation, the height offset H between the initial and final positions of the first bodywork element 11 is substantially equal to the height offset along the direction D present between the first bodywork element 11 as a result of said pre-assembly step in the initial position and the second bodywork element following its final position mounting step. The height offset H between the initial and final positions of the first body element 11 is, in this example, contained in a plane oriented along the transverse Y and vertical directions Z. The value of the offset H will therefore be previously chosen so that free from any risk of contact between the first and second body members 11, 12 under the effect of thermal expansion of the first body member 11 during said at least one heat treatment step. An example of an expanded configuration adopted by the first body element 11 under the effect of a thermal expansion during the heat treatment is represented by the dashed lines in FIG. 4. In this expanded and temporary configuration, the edge of the first element of body 11 adjacent to the second body member 12 is at least partly located vertically along the edge D of the second body member 12 adjacent to the first body member 11. Indeed, under the effect of the expansion of the first element body 11, the edge adjacent to the second body member 12 moves relative to its occupied location in the absence of heat treatment, at ambient temperature conditions. This displacement occurs, for example, in a plane oriented along the longitudinal X and vertical Z directions. The value of the offset H is thus pre-selected so as to allow the first bodywork element 11 to come freely to adopt this expanded configuration without coming into contact. with the second bodywork element 12. For this purpose, the value of H is preferably such that the point of the edge of the first body element 11 located closest to the support 10 according to D is located above the point of the edge of the second body element 12 located furthest from the support 10 according to D.

Preferably, the pre-assembly step of the first bodywork element 11 comprises a step of placing the shim 100 between the first bodywork element 11 and the second bodywork element 12 so that the temporary initial position corresponds to a raised position relative to the final position, the side opposite the support 10. In Figure 4, the shim 100 used is not shown. FIG. 5 represents an additional advantage of this solution during a heat treatment corresponding to a phase of application of paint, such as the operation of cataphoresis and the application of putty, primer, base and varnish. With the local uplift of the first body member 11 induced by the presence of the shim 100, the edge of the first body member 11 adjacent to the second body member 12 is very well covered with paint, so that the first body member 11 is coated with a paint layer 18 (shown in dotted lines) homogeneous even at the edge adjacent to the second body member 12. Similarly, the edge of the second body member 12 adjacent to the first body member 11 is very well covered of paint, so that the second body member 12 is coated with a paint layer 19 (shown in dotted lines) homogeneous even at the edge adjacent the first body member 11. In Figure 5, the shim 100 used n is not represented.

As shown in Figure 3 for example, the location occupied by the shim 100 following its implementation step is located in the flush zone between the first and second body members 11, 12 when they are in their final positions.

In other words, the shim 100 is then placed close to the zone of tangency between the adjacent edges of the first and second body members 11, 12. This does not exclude any other possibility of setting up the shim 100. during the pre-assembly step of the first bodywork element 11, in particular as a function of the ease of access and handling of the shim 100, itself dependent on the spatial organization of the first and second body members 11 12. Preferably, the step of placing the shim 100 comprises a reversible holding step of the shim 100 on the first bodywork element 11 with a fixing step, by means of the screw 13, on the 10 second body member 12, the assembly comprising the first body member 11 and the shim 100 held on the first body member 11. To simplify its implementation, the step of reversibly holding the shim 100 on the first bodywork element 11 preferably comprises: a reversible wedging step of the shim 100 by cooperation by shape conjugation between first positioning elements 101 (FIG. 12) integral with the shim 100 and second positioning elements 110 (FIG. 7) integral with the first bodywork element 11, and a reversible clipping step of the shim 100 on a first fastening element 13 (FIG. 3), in particular a screw, used during said fixing step and ensuring the attachment of the first body member 11 to the second body member 12. As illustrated in FIGS. 7 and 12, the second positioning elements 110 are for example formed by a notch in which a shape conjugation is male part 30 secured to the shim 100 and constituting the first positioning elements 101.

For the implementation of the detent step, the first bodywork element 11 may comprise a passage opening 111 (FIG. 7) passing through the thickness of the first bodywork element 11 and allowing the passage of a first element. for fixing 13 formed by a screw, coming for example to screw into the bodywork element 12, through the thickness of the first bodywork element 11. The shim 100 also comprises latching elements 102 (FIG. example comprising a through hole 104 to be traversed by the first fastening element 13 in the thickness of the shim 100 and having a profile having the shape of a horseshoe arc in which is housed the section of the screw constituting the first Fastening element 13. The detent elements 102 have, for example, generally a U-shape whose two branches 105 delimit between them the orifice 104 and whose internal faces are each provided with a retaining projection 106 disposed at one end of the horseshoe arc. The screw axis of the first fastening element 13 is for example oriented substantially in the transverse direction Y.

It will however be noted that the latching elements 102 and / or the first positioning elements 101 may be of any other nature as long as they are adapted to the desired functions. It is the same for the first fastening element 13.

Following said at least one heat treatment step, the manufacturing method comprises a step of removing the shim 100, by partially unscrewing the screw 13, between the second bodywork element 12 and the first bodywork element 11. simply screw the screw 13 so that the first body member 11 is in the final position on this attachment.

FIG. 6 represents an additional advantage of this solution during a heat treatment corresponding to a paint application phase. The paint layers 18 and 19 are directly adjacent to the interior of the functional game j, conferring good aesthetics and good protection. To facilitate its implementation of the method by an operator, this step of removing the shim 100 preferably comprises a step of applying a manual traction force on the shim 100 at a gripping element 103 integral with the wedge 100 and accessible by the operator from outside the subassembly. With reference to FIGS. 12 and 13, the male part constituting the first positioning elements 101 is for example formed on a part of the shim 100 connecting the gripping element 103 and the detent elements 102, 106. Preferably, the shim 100 is configured so that this force application step automatically causes the removal of the wedge by shape conjugation between the first positioning elements 101 integral with the shim 100 and the second positioning elements 110 integral with the first body member 11 and the suppression of the snap between the shim 100 and the first fastening element 13. For this reason, for example, the latching elements 102 have two panels 105 delimiting between them an insertion slot 108 allowing the placing the first fastening element 13 in the detent elements 102, and then withdrawing it, by simple relative movement of the 100 with respect to the first fastening element 13. The elastic flexibility of the branches 105 allows the first fastening element 13 to pass from one side of the retaining protrusions 106, that is to say of the insertion slot 108 to the through hole 104 and vice versa. The provision of thinned zones 109 at the base of the branches 105 makes it possible to avoid the retention of cataphoresis surface treatment products.

Optionally but preferentially to limit the cost of the solution and to limit the number of parts necessary for the implementation of the method of manufacturing the subassembly, the method comprises, following the step of withdrawal, a step of positioning the the shim 100 between the support 10 and a reinforcing element 14 preassembled on the first bodywork element 11 and reinforcing the first bodywork element 11 against external shocks, in particular oriented in a plane (Y, Z). The location occupied by the shim 100 relative to the first bodywork element 11 following this positioning step is different from that occupied following its implementation step described above to place the first bodywork element 11 in the initial position. For example, they are offset in the longitudinal direction X. To facilitate the establishment of the shim 100 between the support 10 and the reinforcing element 14, the end of each branch 105 is refined in approaching the distal edge and comprises bevelled faces 107, for example in the form of a V (Figure 13). The positioning step preferably comprises a step of actuating, in particular by loosening, a second fastening element 15, in particular a screw, providing a local and reversible embedment connection between the shim 100, the first bodywork element 11. , 14 (preassembled together) and the support 10. Such a screw can cooperate with a nut 16 disposed on the inner side of the support 10. Furthermore, the actuating step preferably comprises a step of contacting 30 between the wedge 100 and an angular locking element 141 (Figure 10), for example in the form of a wall delimiting a slot, formed in the reinforcing element 14 in such a way that the reinforcing element 14 suppresses the degree of freedom in rotation of the shim 100 around the screw axis of a screw constituting the second fastener element 15 during this actuation step. Furthermore, the reinforcing element 14 may comprise a material clearance 142 (FIG. 10) allowing the shim 100 to be placed in such a way as to cooperate by contact with the angular locking element 141. Similarly, the first body member 11 may include a clearance of material 17 (Figure 11) to avoid interference with the shim 100.

The solution described above allows the use of bodywork elements 11, made of plastics while providing a functional play j of low value, especially less than 3 mm. Despite these characteristics, there is no risk of deterioration during contact manufacturing between the body members 11, 12 during heat treatments. An additional advantage is that the shim 100 is used during the heat treatments, including the paint application phase on the body elements, and then is reused on the vehicle for fixing one of the body elements. In other words, the shim 100 is temporarily used at a first location during the heat treatments to avoid any contact between the body elements during the heat treatments, then it is used at a second location as a part participating in the removable attachment. of one of the body components, including the lateral front wing, on the vehicle body. Therefore, the shim used during the manufacture of the subassembly is then a part sold to the customer purchasing the vehicle at the same time as the vehicle. This allows cost optimization. This financial aspect is reinforced by having provided that the shim 100 can be implemented indifferently on a right side or a left side of the body, for example for the attachment of the right front wing or the right side. left front wing. A single mold is then necessary for the manufacture of shims 100.

Claims (13)

REVENDICATIONS1. A method of manufacturing a subassembly of a motor vehicle comprising a support (10) belonging to the vehicle body, a first body element (11), in particular a front lateral wing, mounted on the support (10) and a second body element (12), in particular a bogie, the first and second body elements (11, 12) occupying at the end of the process respective end positions in which they are side-by-side and in the extension l one of the other, characterized in that it comprises: - a pre-assembly step of the first bodywork element (11) on the second bodywork element (12) in an initial position offset from its final position in a direction (D) corresponding to the thickness of the first bodywork element (11), and then at least one heat treatment step applied to the first and second bodywork elements (11, 12) during which the first element bodywork (11) is in its initial position so as not to be an extension of the second bodywork element (12) and to avoid any contact between the first and second bodywork elements (11, 12) under the effect of thermal expansion of the first body member (11) during said at least one heat treatment step, - the pre-assembly step comprising a step of placing a shim (100) between the first body member (11) and the support (10) so that the initial position corresponds to a raised position in the direction (D) corresponding to the thickness of the first body member (11), with respect to the final position, on the opposite side to the support (10). 2. Manufacturing method according to the preceding claim, characterized in that the location occupied by the wedge (100) following said placing step is located in the flush zone between the first and second body members (11). , 12) when they are 5 in their final positions. 3. Manufacturing process according to one of claims 1 or 2, characterized in that the step of placing the shim (100) comprises a step of reversibly holding the shim (100) on the first body member (11) with a step of fixing, on the second body member (12), the assembly comprising the first body member (11) and the shim (100) held on the first body member (11). 4. Manufacturing process according to claim 3, characterized in that the holding step comprises a step of reversible wedging 15 by form conjugation between first integral positioning elements (101) of the shim (100) and second elements. positioning device (110) integral with the first body element (11). 5. Manufacturing process according to one of claims 3 or 4, characterized in that the holding step comprises a reversible clipping step of the shim (100) on a first fastening element (13), in particular a screw, used during said fixing step and ensuring the attachment of the first body member (11) on the second body member (12). 6. Manufacturing process according to one of claims 1 to 5, characterized in that, following said at least one heat treatment step, it comprises a step of removing the shim (100) between the second body element (12). ) and the first bodywork element (11), said removing step comprising a step of applying a manual traction force on the shim (100) at a gripping element (103) integral with the shim ( 100) and accessible from outside the subassembly. 7. Manufacturing method according to claim 6, characterized in that the wedge (100) is configured so that said effort applying step automatically causes the suppression of the wedging by form conjugation between first integral positioning elements (101) of the shim (100) and second positioning members (110) integral with the first body member (11) and / or the suppression of the detent between the shim (100) and the first attachment member (13). ). 8. Manufacturing process according to one of claims 6 and 7, characterized in that following the removal step, the method comprises a step of positioning the shim (100) between the support (10) and a component of reinforcement (14) pre-mounted on the first body member (11) and arranged between the support (10) and the first body member (11) and reinforcing the first body member (11) against external impacts, the occupied position by the shim (100) relative to the first bodywork element (11) following said positioning step being different from that occupied following said placing step. 9. Manufacturing method according to claim 8, characterized in that said positioning step comprises a step of actuating, in particular by loosening, a second fastening element (15), in particular a screw, forming a local embedding connection and reversible between the shim (100), the first body element (11, 14), and the support (10). 10. The manufacturing method according to claim 9, characterized in that the actuating step comprises a step of contacting the shim with an angular locking element (141) formed in the reinforcing element (14). in such a way that the reinforcement element (14) suppresses the degree of freedom in rotation of the wedge (100) around the screw axis of a screw constituting the second fastening element (15) during said actuation step. 11. Wedge (100) configured to implement the manufacturing method according to one of claims 1 to 10. 12. A motor vehicle subassembly, comprising a support belonging to the vehicle body, at least a first plastic body element (11), in particular a front lateral wing, mounted on the support (10) and a second body element (12), in particular a rack jamb, obtained by the implementation of the manufacturing method according to any one of claims 1 to 10 wherein a functional clearance (j) of less than 3 mm is interposed between 20 first and second body members (11, 12) in their final positions. Motor vehicle comprising at least one subassembly according to claim 12.