FR2953442A1 - Method for fabricating structural body part or chassis of motor vehicle, involves forming bore or internal thread opposite to hole for fixation of mechanical element such as engine block and roof of vehicle, to body part or chassis - Google Patents

Abstract

The method involves co-operating shapes of skins with each other in assembling position with partial covering to form a closed hollow body (4). A metal coupler is integrated with an outer skin (2) or with an inner skin (3) at a level of a place of the hollow body during subsequent assembling for permitting the confinement by sandwiching the coupler between the skins. A bore or internal thread (6) of the coupler is formed opposite to a hole (7) of the skins for fixation of a mechanical element such as engine block, suspension and roof of vehicle, to a body part or a chassis. An independent claim is also included for a shell chassis for a motor vehicle comprising two parts.

Description

The present invention relates to a method of manufacturing a structural part of bodywork or chassis of a motor vehicle and a hull frame of a motor vehicle of which at least one of the parts is obtained by carrying out the method.

The use of composite material has developed in recent years in the field of the automotive industry. The advantage of this technology is to be able to have parts that fulfill both the role of structure and dressing room. This results in a simplification of the manufacturing process.

Heretofore, for producing such composite parts, a core of rigid foam is enclosed in a mold between an inner skin and an outer skin made of glass fibers, then resin is injected to impregnate the fibers of the skins and the core, resin. Such an embodiment method is for example described in document FR-2,752,769. However, such a manufacturing method has the disadvantage of requiring the production of a preformed rigid foam core in a specific mold, on the other hand the use of a relatively complex closed mold for the final assembly, which increases the manufacturing cost of the composite part.

Another known method consists in molding by molding an outer skin and an inner skin of polymer material, bringing the inner skin and the outer skin together in their assembly position, the shapes of said skins cooperating between they form a substantially closed hollow body, to inject foam of the thermosetting cellular polymer type in the hollow body to fill the latter and ensure cohesion between the inner skin and the outer skin. In addition to the fact that it is necessary to form holes in the said skins for the injection of the foam, it is found that the final piece obtained does not have sufficient mechanical strength to couple it to another part that can produce on said mechanical part of the important efforts. It is therefore difficult to subsequently assemble said parts together without reinforcing them by providing external reinforcing elements at the coupling zones.

An object of the present invention is therefore to provide a manufacturing method whose implementation allows, in a simple, fast and inexpensive way, obtaining parts with both structure and dressing function with high mechanical strength. .

Another object of the present invention is to provide a shell frame obtained by implementing the method whose design allows easy assembly between said parts.

Another object of the present invention is to provide a hull frame obtained by implementing the method whose design makes it possible to obtain a so-called safety cell, protecting the driver and the passengers of said vehicle.

For this purpose, the subject of the invention is a method for manufacturing a structural component of a bodywork or a vehicle chassis, said method comprising at least: a step, called a molding step, during which molding is carried out at least two skins, one of which is external, the other internal, of a composite material, and a gluing assembly step in which the outer skin and the inner skin are brought together against each other. other, at least partially overlapping, and held together by gluing, the forms of the outer skin and the inner skin cooperating with each other in this overlapping assembly position at least partially to form at least one body substantially closed hollow, characterized in that said method comprises, 3o prior to the step of assembling the outer skin and the inner skin against each other, at least one step of joining at least one coupler metallic to the skin external or to the inner skin at the location of said, or at least one of the hollow body formed during the subsequent assembly step to allow, during the assembly step, the trapping by sandwiching the or each coupler between outer and inner skins, said or each coupler comprising at least one bore or tapping formed opposite a piercing of the outer skin and / or the inner skin for subsequent fixation of a mechanical element, such as engine block, suspension, roof of the vehicle or the like to said bodywork part or chassis.

The integration of a metal coupler between said prefabricated skins makes it possible to have a strong fastening base for coupling said part to a mechanical element.

The prefabrication of the skins before their assembly makes it possible to manufacture skins of simplified shape using mold of simple and therefore inexpensive design and finishing of the skins so that the piece obtained is at the same time a piece of structure and shape. dressing.

Preferably, the or each coupler is secured to the inner skin and / or to the outer skin by gluing. Indeed, the skins and the coupler are preferably assembled by gluing so that the piece can be devoid of connecting members visible outside the members which serve to couple the piece to another mechanical element when this mechanical element has not yet been attached to said part. Such bonding assembly reduces the time required to manufacture such a part.

Generally, during the molding step of a skin, at least one fiber web is placed inside said mold, in dry form, the mold is closed and a binder, such as a binder, is injected under vacuum. epoxy resin.

The use of non-impregnated web facilitates the implementation of the manufacturing process.

The invention further relates to a motor vehicle hull frame, of the type comprising at least two parts delimiting, in the assembled state, a passenger compartment having a floor, two side faces, a front face and a rear face. , characterized in that at least one of the parts of the hull frame said coupler part (s) is performed by implementing the method of the aforementioned type.

In other words, at least one of the parts, called the coupler part, of the shell frame is formed of at least two composite material skins assembled at least partially by gluing and having shapes cooperating with one another in this assembly position to form at least one substantially closed hollow body inside which is arranged, in particular imprisoned, by sandwiching between said skins, a coupler, this coupler comprising at least one bore or tapping arranged opposite piercing the outer skin and / or the inner skin for subsequent attachment of a mechanical element.

In the embodiment of the type in which the two or at least two compartments of the passenger compartment compartment are each formed of at least one outer skin and one inner skin, assembled to one another at least partially overlapping by gluing, the inner or outer skin of one or at least one of the parts may form at least part of the outer skin, or inner skin, of the other or of a other room. Similarly, in the embodiment of the type in which two or at least two delimiting parts of the passenger compartment are each formed of at least one outer skin and one inner skin assembled to one another at least partially overlapping by gluing, the inner or outer skin of one or at least one of the parts may have at least one part in overflow of the outer skin, or respectively inner of said piece this overlying portion forming at least a portion of the outer or inner skin of the other or another piece.

In other words, the skin of one of the parts has a portion overflowing from the other skin of said part, this part in overhang forming at least part of the inner or outer skin of the other or of another room. In a particular embodiment of the invention, the or at least one of the coupler parts of said shell frame has shapes of the outer skin and the inner skin which cooperate with each other to form the minus two hollow bodies, at least one of the hollow bodies housing a coupler. The other or the other of said hollow bodies are either coupler-free or equipped with a coupler.

According to a first variant of the invention, the two parts or at least two parts of the shell frame which delimit in the assembled state a cockpit compartment 15 are coupler parts (s) each formed of an outer skin affecting the shape of a box and an internal skin affecting the shape of a half-shell, one of the half-shells being hollowed out centrally, said inner skins being superposable and assembled by a joint plane to form the floor , the side faces, the front face and the rear face of said passenger compartment compartment, said outer skins being capped, one the front face, the other the rear face of the passenger compartment delimited by said half-shells, at least one coupler being trapped between the outer skin and the inner skin of each piece.

According to a second variant of the invention, the two parts or at least two of the parts of the shell frame which delimit in the assembled state a compartment of the passenger compartment are coupler parts (s) each formed of an outer skin affecting the shape of a box and an inner skin in the form of a half-shell, one of the half-shells being recessed centrally, said inner skins being superposable and assembled by a joint plane to form the floor, the two lateral faces, the front face and the rear face of said passenger compartment, said outer skins each cap a side face of said passenger compartment, at least one coupler being trapped between the inner skin and the outer skin of each room. Preferably, the or at least one of the couplers has the shape of a metal block, said block being provided with at least one bore or tapping. The invention will be better understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which:

Figure 1 shows an exploded perspective view of a frame according to the invention according to a first embodiment of the invention;

Figure 2 shows a perspective view of the shell frame of Figure 1 in the assembled state of the constituent elements;

Figure 3 shows a sectional view of the front portion of the shell frame of Figure 1 taken at the couplers;

Fig. 4 is a sectional view of the front portion of a shell frame made similar to that shown in Fig. 1 with a block type coupler type;

Figure 5 shows a partial sectional view of the rear portion of the shell frame of Figure 1 taken at the couplers;

Figure 6 shows a partial sectional view of the shell frame of Figure 1;

FIG. 7 shows an exploded perspective view of a shell frame according to the invention according to a second embodiment of the invention. As mentioned above, the subject of the invention is a part manufacturing process. 1A, 1B structural body or vehicle chassis. The production of such parts comprises a molding step of at least two skins molded independently but selected with shapes that cooperate with each other to form, in an at least partially overlapping assembly position, at least one body 4 substantially closed hollow. The molding of a skin therefore consists in disposing inside a mold, generally of simple shape, a sheet of fibers in dry form. This web of fibers may be formed of multiaxial and unidirectional carbon fabrics which are positioned in the mold in accordance with a predetermined draping plane which defines the number of folds and the orientation of the fibers within said mold. This layer of fibers may also be formed of cut dry fibers.

The mold is closed and a binder, such as resin, preferably epoxy, is injected under vacuum into said mold, said mold being heated to a temperature generally between 50 and 100 ° C. The mold is then opened and the skin is demolded and cut and machined by including drilling to form a finished element. In parallel with the molding of the skins, at least one coupler is made. This metal coupler, generally made of steel or aluminum, may be a molded and / or machined and / or shaped and / or folded part. This coupler 5 is surface treated to prepare its bonding to the skins.

In the example shown in Figure 4, the coupler 5 has the shape of a metal block 25, said block being provided with at least one bore or tapping. This bore or tapped hole is shown at 6 in the figures.

In the example shown in FIGS. 3 and 5, the coupler is a generally omega-shaped profile section, the top of said omega being provided with at least one bore 6 or tapped hole. This bore 6 or tapped hole is intended to receive a fastener 14, such as screw, waiting for the subsequent attachment of a mechanical element to said part. In this case, in the examples shown, the couplers comprise additional bores to allow the subsequent fixation by screwing a plate 13 along one of the faces of the coupler. This plate 13 is in no way required. Once all the components of the part have been completed, the assembly operation can take place. The assembly of the skins and metal couplers is made from a shaper which puts in geometry all the components with respect to the vehicle reference system in the case of the realization of a chassis vehicle shell. The assemblies are made at least by gluing with a two-component epoxy or polyurethane glue. The coupler or couplers are pre-assembled, preferably by gluing, and possibly by screwing, to one of the skins, for example to the outer skin on the face of said skin intended to be turned towards the other skin at the level of the skin. the location of a hollow body 4 to be formed by the subsequent assembly of said skins to enable said coupler to be enclosed between said skins during the assembly of the outer skin with the at least partially overlapped inner skin of said outer skin and assembled by bonding to this outer skin. This assembly between outer skin and coupler is made such that at least the piercing 7 of the outer and / or inner skin is formed opposite the bore 6 or tapping of the coupler. The drilling / tapping assembly 7 receives a fastener, such as a screw 14, which will be used for the subsequent fixing of a mechanical element (not shown).

In the examples shown, the shapes between inner and outer skins cooperate with each other to provide at least two hollow bodies inside which each coupler is trapped. Of course, the number of hollow bodies can vary without departing from the scope of the invention. Similarly, it is possible to have inside the same hollow body one or more couplers. Finally, some hollow bodies formed may be free of couplers.

In the examples shown, each piece further comprises a plate 13 attached to the outer face of one of the skins, that is to say on the face of the skin opposite that facing the other skin. This plate 13 is fixed by screwing to the coupler and allows a better distribution of forces. This plate 13 is in no way required.

From the manufacture of parts, as described above, a motor vehicle hull frame can be realized. Figures 1 and 2 illustrate an embodiment of a first shell frame according to the invention. This hull frame is formed of at least two coupler parts which delimit, in the assembled state, a passenger compartment. These two coupler parts are each formed of an outer skin affecting the shape of a box and an inner skin 3 having the shape of a half-shell, one of the half-shells being hollowed out centrally. These half-shells are half-shells called flat bottom. In particular, these half-shells of parallelepipedal general shape, have a substantially flat bottom hollowed out for one of the half-shells and not hollowed out for the other half-shell, two transverse sides adjacent said bottom and two longitudinal flanks, said flanks longitudinals being intended to form the side faces 9 of the passenger compartment, the transverse sides being able to form the front face 10 and the rear face 11 of the passenger compartment. It should be noted that each skin can be made of one or more elements each formed by molding. In the examples shown, each skin is made in one piece. Preferably, each skin is free of undercut to facilitate the manufacture of the mold.

The inner skins 3 are stackable and assembled by a glued joint plane to form the floor 8, the side faces 9, the front face 10 and the rear face 11 of said passenger compartment. The outer skins 2 come to cap one on the front face 10, the other the rear face 11 of the passenger compartment delimited by said half-shells. Prior to the establishment of external skins and their bonding to the inner skin, at least one coupler is pre-assembled to the inner or outer skin preferably at least by gluing. In the examples shown, four couplers are pre-assembled to each inner skin in the form of a half-shell. Each coupler is disposed near an end of a longitudinal flank of the half-shell. Each outer skin, because of its open-box shape on one of its faces, comes, through the walls of the box, to cap one of the front or rear faces of the compartment 2953442 i0 formed by the two half shells and a portion of the longitudinal flanks of said half-shells, part in which are arranged the couplers. Each coupler is thus trapped between two skins. In the example shown, it is noted that the outer skin of each of the 5 pieces has a portion protruding from the inner skin of said piece to form at least a portion of the outer skin of the other piece. Once the cabin compartment of the hull frame thus formed, it can be attached to said hull frame by gluing, at least one reinforcing element. This reinforcing element may be in the form of an additional composite part capable of cooperating with the base frame to delimit by cooperation of shapes between the composite part and the base of the shell frame at least one hollow stiffening body of the assembly. Such an additional composite reinforcing element is shown at 15 in FIG.

Figure 7 illustrates another embodiment of a shell frame according to the invention. In this second embodiment, the shell frame is formed again of at least two coupler parts which define in the assembled state a passenger compartment. These two coupler parts are each formed of an outer skin 2 which is in the form of a box and an inner skin 3 which is in the form of a half-shell. The half-shells have the same shape as that described in the first embodiment. One of the half-shells is hollowed out centrally. Said inner skins 3 are stackable and assembled by a glued joint plane to form the floor 8, the two lateral faces 9, the front face 10 and the rear face 11 of the passenger compartment. The outer skins 2 each cap a side face 9 of the passenger compartment or in other words each is applied to a longitudinal sidewall of each of the half-shells and come, through the other walls of the box, overlap part of the front or the rear face of the passenger compartment delimited by said half-shells. The couplers are here arranged at the level of the inner skins on the front face or respectively the rear face of the passenger compartment delimited by said inner skins so as to be covered and locked inside the compartment during the establishment of the skins. external parts that partially overlap the front face and the rear face of said passenger compartment. Again, the outer skin of one, in this case each, of the parts has an overhang portion adapted to form at least a portion of the outer skin of another room.

Claims (10)

REVENDICATIONS1. A method of manufacturing a structural part (1A, 1B) of bodywork or vehicle chassis, said method comprising at least: - a step, called molding, during which is produced by molding at least two skins called the one, external (2), the other, internal (3), of a composite material, and - a gluing assembly step during which the outer skin (2) and the inner skin (3) are brought against each other, at least partially overlapping, and held together by gluing, the forms of the outer skin (2) and the inner skin (3) cooperating with each other in this assembly position to at least partial overlap for forming at least one substantially closed hollow body (4), characterized in that said method comprises, prior to the step of assembling the outer skin (2) and the inner skin (3), against one another, at least one step of joining at least one coupler (5) metal to the skin external (2) or to the inner skin (3) at the location of said, or at least one of, hollow body (4) formed during the subsequent assembly step to allow, during the assembling step, sandwiching of the or each coupler (5) between outer (2) and inner (3) skins, said or each coupler (5) comprising at least one bore or tapping (6). ) arranged opposite a piercing (7) of the outer skin (2) and / or the inner skin (3) for subsequent attachment of a mechanical element, such as engine block, suspension, roof of the vehicle or other to said body part or chassis. 2. Method according to claim 1, characterized in that secures the or each coupler (5) to the inner skin (3) and / or the outer skin (2) by gluing. 3. Method according to one of claims 1 and 2, characterized in that, during the molding step of a skin is disposed inside said mold, in dry form at least one layer of fibers, the mold is closed and a binder, such as an epoxy resin, is injected under vacuum. 12 4. Motor vehicle hull, of the type comprising at least two parts (1A, 1B) defining, in the assembled state, a passenger compartment comprising a floor (8), two lateral faces (9), one face front (10) and a rear face (11), characterized in that at least one of the parts (1A, 1B) of the hull frame called coupler part (s) is formed by implementing the method according to the one of claims 1 to 3. 5. hull according to claim 4, the type of which the two or at least two parts (1A, 1B) delimiting the passenger compartment are each formed of at least one outer skin (2) and a skin internal (3), assembled to each other at least partially overlapping by gluing, characterized in that the inner or outer skin of one or at least one of the pieces forms at least part of the outer skin, or inner skin, of the other or of another room. 6. Hull according to one of claims 4 and 5, the type of which two or at least two parts (1A, 1B) delimiting the passenger compartment are each formed of at least one outer skin (2) and an inner skin (3) assembled to each other at least partially overlapping by gluing, characterized in that the inner skin (3), or outer skin (2), of one or to at least one of the parts (1A, 1B) has at least one part in overflow of the outer skin (2), or respectively inner (3) of said part, this part in overhang forming at least part of the outer skin or internal of the other or another room. 7. Hull according to one of claims 4 to 6, characterized in that the, or at least one of the parts (1A, 1B) coupler (s) of said shell frame has forms of the outer skin ( 2) and the inner skin (3) which cooperate with one another to form at least two hollow bodies (4), at least one of the hollow bodies (4) housing a coupler (5). 8. hull according to one of claims 4 to 7, characterized in that the two parts (1A, 1B) or at least two parts of the hull frame which define in the assembled state a compartment of the cabin are parts with coupler (s) each formed of an outer skin (2) affecting the shape of a box and an inner skin (3) affecting the shape of a half-shell, one of the half-shells being hollowed out centrally, said inner skins (3) being superimposable and assemblable by a joint plane to form the floor (8), the side faces (9), the front face (10) and the rear face (11) of said cockpit compartment , said outer skins (2) coming to cap it, one the front face (10), the other the rear face (11) of the passenger compartment delimited by said half-shells, at least one coupler (5) being trapped between the outer skin (2) and the inner skin (3) of each piece (1A, 1B). 15 9. Hull according to one of claims 4 to 7, characterized in that the two parts (1A, 1B) or at least two parts of the hull frame which define in the assembled state a compartment of the cabin are parts with coupler (s) each formed of an outer skin (2) affecting the shape of a box and an inner skin (3) affecting the shape of a half-shell, one of the half-shells being centrally recessed, said inner skins (3) being superposable and assemblable by a joint plane to form the floor (8), the two lateral faces (9), the front face (10) and the rear face (11) of said compartment the passenger compartment, said outer skins (2) each capping a side face of said compartment compartment, at least one coupler (5) being trapped between the inner skin (3) and the outer skin (2) of each piece. 10. Hull according to one of claims 4 to 9, characterized in that the or at least one of the couplers (5) has the shape of a metal block, said block being provided with at least one bore or tapping (6).