FR2799718A1 - Fabrication method for vehicle passenger and engine compartments, incorporates intervening soundproofing insulation separator - Google Patents

Abstract

Vehicle passenger and engine compartments are fabricated, with an intervening separator (20). The instrument panel (30) is made, and Intervening soundproofing insulation (40/140) is formed and connected to it. This assembly (100) is brought to face the separator, sandwiching the insulation. The resulting assembly is fixed into the vehicle structure.

Description

The field of the invention is that of the embodiment of elements of a vehicle in particular in relation to the insulation of the engine block relative to the passenger compartment of said vehicle.

To isolate the cabin of a vehicle noise and vibration caused the engine, it is common to use an insulating coating is applied against the deck separating the engine compartment cockpit. coating, which may for example be made of felt or foam lined with dense sound-absorbing septum, is typically mounted on said apron before passing cables or other elements necessary for the proper functioning of the vehicle (steering column, air conditioning duct) through of holes provided before coming up over a board board.

this mounting method has drawbacks. In particular, positioning of the dashboard with respect to the insulating coating is not ideal, errors in the positioning elements to pass through the orifices of the coating may exist. moreover, at vehicle manufacturer, there are too many steps to fix the coating and then the dashboard on the apron, which causes time losses on production lines. Thus, the invention aims to solve at least part of these problems.

For this purpose, the invention proposes an assembly method for vehicle manufacturing, in which the following steps are carried out to form a vehicle structure comprising a passenger compartment, an engine compartment and a separation zone between the passenger compartment and the engine compartment, to be realized. a dashboard, realize a soundproofing for the soundproofing of the passenger compartment compared to the engine compartment, characterized in that, before bringing the dashboard opposite the separation zone - it is soundproofing to the board edge, - it brings the assembly thus formed opposite the separation zone by interposing the soundproofing between the dashboard and said separation zone, and - this set to the structure of the vehicle.

to facilitate the connection between the soundproofing and the dashboard, it is expected, during the production of the dashboard, to integrate therewith means for connecting the soundproofing.

In order to prevent the soundproofing from deforming before it is fixed on the vehicle structure, passages will be made through the soundproofing so that the latter is traversed by functional elements that are useful for the operation of the vehicle, and the mechanical strength will be locally reinforced. soundproof at least around these passages and / or between them.

 According to another aspect of the invention, during the realization the soundproofing, we can arrange passages through it and fix substantially tubular studs in these passages before binding the soundproofing instrument panel, then pass through these studs and these passages functional elements useful for the operation of the vehicle.

To obtain the soundproofing, it will be preferable to carry out the following steps - to heat a layer of felt and a layer of dense soundproof septum, - to arrange the felt layer and the dense sound-absorbing septum layer heated in a mold, and - to press the layer of felt and the dense sound-absorbing septum layer together to compress and locally compress the layer of felt to crush it deeply to create a local reinforcement.

Alternatively, a dense sound-absorbing septum layer and reinforcing elements may be provided in a foaming mold, and the foam may be injected into the mold to form an expanded foam layer including the reinforcing elements.

In particular, it is possible to place in the mold substantially tubular studs which will then be included in the foam during its injection in order to create passages passing through said foam layer.

In order to optimize the attachment of the insulation to the dashboard, it is expected that the dense sound-absorbing septum conforms to have male means of said connection with the board.

The invention also relates to a cockpit for driving a motor vehicle which comprises a vehicle structure, a cockpit, an engine compartment and a separation zone between the cockpit and engine compartment, the cockpit including dashboard, soundproofing for soundproofing of the passenger compartment with respect to the engine compartment, and means for fixing the dashboard and the soundproofing to the separation zone, characterized in that the cockpit further comprises means dashboard binding to the soundproofing , regardless of dashboard attachment to the separation area.

For questions of integration and ease of manufacture, the dashboard may include a rigid insert incorporating a means of connection to the soundproofing.

now interested in the soundproofing, it may include a first sound-absorbing layer intended to cover the separation zone, a second sound-absorbing layer bonded to the first layer covering at least partially, orifices passing through the soundproofing for the passage through it functional elements useful for the operation of the vehicle, substantially tubular acoustic absorbent pads surrounding these orifices, and local reinforcement means arranged around these orifices and / or between them, the pads and the reinforcing means being separate from each other or made of a single piece.

in particular, the soundproofing may comprise a first layer of felt, a second layer forming a dense sound-absorbing septum and substantially tubular acoustic absorbent pads disposed around through orifices for the passage of functional elements useful for the operation of the vehicle, each stud being inserted into an orifice the separation zone so as to damp the vibrations undergone by this zone.

so as to stiffen the soundproofing without impairing its functional appearance, felt layer may be compressed locally around the orifices at least between them to define reinforcement zones.

According to another aspect of the invention, the sound-absorbing material may comprise a layer of foam, a layer forming a sound-absorbing septum, and substantially tubular sound-absorbing pads disposed around orifices passing through it for the passage of functional elements that are useful for the operation. of the vehicle.

In particular, the foam layer may include more rigid inserts and arranged around the orifices and at least between some of them to locally define zones of reinforcement.

to improve the acoustic properties of the soundproofing, may provide that each stud is axially surmounted by a soft acoustic absorbent material seal such as an elastomer, said seal can then be inserted into an orifice of the separation zone so as to dampen vibrations circulating in said zone.

For the same purpose the stud may form a single piece of flexible acoustic absorbent material, such as an elastomer.

in order to contribute to the improvement of the acoustic properties of the soundproofing, it is also possible to provide that the inserts are integrally embedded in the foam layer so that they are at a distance and disconnected from the septum layer.

It can also be provided that the pad is distinct acoustically decoupled from the insert while being structurally connected to it by means of a coupler of flexible acoustic absorbent material such as an elastomer.

Finally, in order to facilitate the manufacture of the soundproofing, the foam layer may include a ring more rigid than surrounding each passage of the soundproofing.

In order to improve the acoustic properties of the soundproofing material, the septum layer will preferably be locally acoustically disconnected from the pads so that the vibrations circulating in the separation zone and / or the functional elements passing through the soundproofing are damped before pass into the septum layer.

 The invention and its implementation will appear even more clearly with the aid of the description which follows, refers to the drawings in which - Figure 1 is a perspective view of a vehicle body / frame, - Figure 2 is A perspective view of some of the elements of the invention, - Figure 3 is a front view of a soundproofing according to the invention - Figure 4 is a detail sectional view of Figure 3 of the soundproofing once 5 is a front view of an alternative embodiment of FIG. 3; FIG. 7 is a broken view of the FIG. 6, - Figure 8 is another variant embodiment of Figure 4, and - Figures 9 to 12 are alternative embodiments of Figure 6.

In Figure 1, one can see a body (or a chassis) of a motor vehicle shown in perspective. This body 10 has in particular a passenger compartment 12, a motor compartment 14 and a zone 20 (wall) separation (commonly called apron or apron sheet) between the two. This partition wall serves as insulation (especially thermal phonic) between the engine compartment 12 and the passenger compartment 14 as structural reinforcement of the body can also be noted the presence of pillars A 16 and 18 disposes part and other deck 20 which also serve to stiffen the vehicle body.

Figure 2 shows in exploded perspective the main elements of the invention. We thus see the separation wall which is crossed by multiple openings 22 of different dimensions. These openings 22 serve for the passage of various functional elements necessary for the proper functioning of the vehicle, such as a steering column, many cables (bundled or not in bundles) or ventilation / defrosting lines.

FIG. 2 also shows, in the background, a dashboard 30 of known type, generally made of molded plastic material (s) and on which part of the functional elements already mentioned are mounted (column). steering, various warning lights and indicators, aeration / defrosting system).

Also seen between the dashboard 30 and the deck 20 a soundproofing 40/140 connected to a plate 50 intended in particular to support the steering column (and other functional elements) and to seal at least some of the orifices 22 the type of soundproofing 40/140 used can vary. We will describe here two types in particular, with the realization techniques that allow to obtain them.

 According to a first embodiment shown in Figures 4 the soundproofing 40 is composed of a felt layer 42 and a layer 44 of more dense septum and soundproofing (also called heavy mass).

felt layer can be made of polyester or phenolic resin. septum leaf is made of a thermoplastic material incorporating fillers and denser than the felt layer.

septum may in particular consist of a plastic resin containing a high level of inorganic fillers (chalk or barium sulfate) with a high molecular weight, a polyolefin mixture (ethylene vinyl acetate, low density polyethylene) or EPDM polymers (Ethylene Propylene Diene Monomer) or be presented as a heavy mass as described in FR-A-2,733,933.

In some places (see also FIGS. 2 and 3), soundproofing 40 has openings 45 for the passage of functional elements such as those already mentioned (mainly cables and air ducts). Some openings are blocked by the plate 50 (see figure while others remain open and are masked by dashboard to achieve all this soundproofing 40, a layer 42 of felt and layer 44 of dense soundproof septum as described previously, these heated layers are placed in a mold (not shown) and the layer 42 of felt and the dense sound-absorbing septum layer 42 are pressed together to form a unitary assembly. Soundproofing in the mold so that it has the three-dimensional shapes adapted to marry those generally quite complex apron 20. Preferably, septum completely covers the felt layer, although this is necessary everywhere.

passage orifices 45 arranged through the sound-absorbing material 40 are made either in the mold at the time of the pressing step, layered against one another with the aid of cores or punches, or before heating and placing the two layers in the mold, for example piercing.

In the solution shown, substantially tubular studs 46 of plastic material are inserted in the passages 45 before binding the soundproofing to the dashboard. They can be used in particular to facilitate the passage, through the soundproofing, of functional elements such as cables 90.

As the sound absorbing 40 has a fairly flexible structure, it is expected to strengthen locally its mechanical strength at least around these passages 45 and / or between them. For this, it is expected to locally compress layer 42 of felt to crush it deeply to create reinforcing areas 48 shown in Figures 4 and 5 and schematized in dashed lines in Figure 3. It is best not to too much crush the layer 42 felt to avoid creating reinforcing zones 48 too rigid may transmit noise too easily, these reinforcement areas being in direct contact with the septum layer. It is also necessary to maintain a certain flexibility in the soundproofing device 40 to prevent any breakage of the latter openings 45.

Another alternative embodiment is illustrated in Figures 6 to 7. In this variant, the soundproofing 140 is composed of a layer 142 of foam (typically polyurethane or having the same acoustic mechanical properties) and a layer 144 of septum plus dense and sound-absorbing (a heavy mass as already described) which preferably covers the entire layer of foam, except possibly in some places where it is not necessary.

In certain places (see also FIGS. 2 and 3), soundproofing 140 has openings 145 for the passage of functional elements such as those already mentioned (cables 90 for example).

For the same reasons as those mentioned above, it is preferable locally to strengthen the mechanical strength of the soundproofing 140 because it is relatively flexible. Thus, the foam layer 142 contains reinforcing inserts typically made of rigid acoustic dampening plastic material such as polypropylene or the like. As can be seen dashed in Figure 3, in section in Figure 6 and front in Figure 7, these inserts 148 are arranged around the orifices 145 passage functional elements, as well as between them. In Figures 6 and 7, the pads are integrated inserts 148 which facilitates their installation.

To achieve this sound-absorbing 140, the dense sound-absorbing septum layer 144 and the reinforcing elements 148 are placed in a foaming mold (not shown) and foam is injected into the mold including reinforcing elements 148 forming a layer 142 of expanded foam .

Making orifices 145 passing through the soundproofing can be done in two ways.

According to a first embodiment, before introducing the septum layer, it is pierced locally where the holes are desired. The septum layer 144 is placed in the mold which then has protuberances (cores) coinciding with these holes projecting the thickness of the septum layer 144 molded inwardly. The foaming operation is then carried out which causes the formation of the foam layer 142 and completes the formation of the orifices 145 around the protuberances. It then remains to place tubular studs (similar to those of Figures 4 and 5) inside the orifices 145 thus formed once the part demolded.

 According to another preferred embodiment shown in FIGS. 6 to 12, the septum 144 is still pierced, but substantially tubular studs 146 are inserted (see FIGS. 6 and 7) in the inserts 148. Once the inserts 148 have been placed on the layer septum with the pads projecting from the septum layer 144 towards the molded interior, the foaming operation is carried out so as to form the foam layer 142 which includes said pads 146 so as to form the passages Previously, one may be inserted above the pad 146 a seal 141 made of flexible material such as elastomer to improve the acoustic properties soundproofing and facilitate future connection with the sheet of the deck. For this purpose, a metal seal 143 may serve as a junction with said sheet and locally stiffen the soundproofing.

Other variants will now be described only in their structure.

Thus, in FIG. 8, the septum layer 44 of the sound absorbing material 40 is not included in the stud 46 at its end as in the figure. In this case, it stops before this stud 46 to avoid being in contact. contact with him (and therefore indirectly with the sheet of the apron). This solution thus improves the acoustic properties of the soundproofing 40 (better soundproofing) because the vibrations are not transmitted directly from the apron to the septum. But it is a little more expensive to realize than that in FIG. 4 because instead of a single cutting operation of the two layers to make the orifice 45, there is a cutting operation for the felt one for the septum 44.

Figures 9 to 12 represent a few other embodiments of Figure 6 which improve the acoustic properties and / or to facilitate the design and manufacture of the soundproofing. Thus, in FIG. 9, the insert 148 made of rigid plastic material is totally embedded in the layer 142 of foam that is on either side of the insert so that the latter is not in contact with the layer 144 of septum. In addition, the rubber seal 141 surrounding the stud and inserted into the sheet of the deck is oversized (thickness and diameter in particular) to further improve the acoustic properties of the soundproofing 140 and reduce the transmission of vibration undergone apron sheet.

In FIG. 10, a coupler 147 is integrated in the middle of the insert so as to separate an elongate portion 148a from the insert of the decoupler stud 147, made of a softer material than the insert (an elastomer for example), reduces the vibrations transmitted sheet metal deck to the insert 148 of rigid plastic material. It therefore improves the acoustic properties of soundproofing 140.

In FIG. 11, a further rigid seal 149 is integrated into the foam layer 142 between the pad 146 of the insert 148 and the septum layer. This solution makes it possible to better position the stud 146 during foaming, but it tends to slightly degrade the acoustic properties of the soundproofing 140 because of the material used and because of contact with the septum and the stud.

Finally, in FIG. 12, the seal 141 and the pad 146 form a single piece of flexible acoustic absorbent material such as an elastomer so as to improve the acoustic properties of the soundproofing element 140.

All these alternative embodiments make it possible to attenuate more or less strongly the vibrations and the sounds coming from the engine block transmitted to the apron sheet. They are made and use the same materials as the soundproofing of Figures 4 to 7.

We will now describe an assembly method according to the invention for the manufacture of a vehicle and in particular for the assembly of a car cockpit 100 to its chassis 10. This method involves the steps below in the order in which they are quoted.

Firstly, a vehicle structure (for example a box 10) comprising a passenger compartment 12, an engine compartment 14 and a separation zone 20 between the passenger compartment and the engine compartment, as shown in FIG. The techniques used are known and often automated, in particular via the use of a welding robot.

A dashboard 20 made of plastic material is also produced separately, also using a known technique such as injection molding. During the production of this dashboard 20, it is possible to integrate therewith connecting means 60 of the soundproofing such as hooks or equivalent means (lugs). This integration of the connecting means 60 can be done either directly molding or post-mold release, for example on a mechanically reinforced portion of the dashboard such as a cross or a rigid insert. These hooks 60 cooperate with slots 49/149 provided in the upper part the soundproofing during its shaping (inside the mold out of the mold).

40/140 soundproofing is carried out for the soundproofing of the passenger compartment 14 with respect to the engine compartment 12, using one of the techniques described above according to the type of soundproofing it is desired to install.

Before bringing the dashboard opposite the separation zone, the soundproofing is connected to the dashboard by means of the connecting means 60 and the slots 49/149 of the soundproofing so as to form a unitary transportable unit called cockpit, referenced 100.

Platinum 50 is also fixed to the soundproofing, before or after having fixed the soundproofing to the dashboard, this plate supporting at least some of the functional elements described which are then passed through the orifices 45/145 of the soundproofing 40/140. then brings the assembly thus formed facing deck 20 by interposing soundproofing 40/140 between the dashboard said apron 20, this set is fixed to the vehicle structure by known means (including screws) may or may not cross the soundproofing to ensure better attachment of it to the deck. For the lower part of the soundproofing, inserts may also be used.

cockpit 100 thus comprises means of connecting the board to the soundproofing independently of the fixing the board to the vehicle structure.

Thus, the cabin is well soundproofed engine compartment, and the assembly method described saves time while improving the positioning of the soundproof compared to the dashboard and apron. The passage of the functional elements is also facilitated by the presence of the studs and the structure of the soundproofing is reinforced locally to facilitate its implementation.

The invention is in no way limited to the preferred embodiments illustrated solely by way of example.

Thus, in the two types of soundproofing described, the dense sound-absorbing septum layer may be shaped so that it has means (shown in dashed lines and referenced 70 in FIG. 3) for connecting the dashboard. may be hooks, pawns, staples or other equivalent means likely to ensure a good connection with dashboard and adapted to support the weight of the soundproofing.

To reinforce the soundproofing around the orifices, it is also possible to provide protrusions on the apron 20 and arranged directly opposite these orifices 45/145 so as, for example, to fit in or around the seals 46/146.

Claims (10)

<U> Claims </ U> 1. A method of assembly for the manufacture of a vehicle, wherein the following steps are carried out: - producing a vehicle structure (10) comprising a passenger compartment (12), an engine compartment (14) and a zone (20) of separation between the passenger compartment and the engine compartment, - make dashboard (30), - realize sound-absorbing (40/140) for the soundproofing of the passenger compartment (12) relative to the engine compartment (14), characterized by what, before bringing the dashboard (30) opposite the separation zone (20) - the soundproofing (40/140) is connected to the dashboard (30), - the assembly (100) is brought formed opposite the separation zone (20) by interposing the soundproofing (40/140) between the dashboard (30) and said separation zone (20), and - is fixed together with the structure (10) of the vehicle. 2. Method according to claim 1, characterized in that during the production of the dashboard (30), there is incorporated therein means (60) for connecting the soundproofing (20). 3. Method according to any one of the preceding claims, characterized in that - passages (145/145) are made through the soundproofing (40/140) so that the latter is traversed by functional elements useful for vehicle operation, and - locally reinforcing the mechanical strength of the soundproofing at least around these passages and / or between them. 4. Method according to claim 1, characterized in that - during the realization of the soundproofing (40/140), it provides passages (45/145) through it, and - fixed pads (46/146) substantially tubular in these passages before binding the soundproofing (40/140) to the dashboard (30), then is passed through these pads (46/146) and these passages (45/145) useful functional elements. vehicle operation. 5. Method according to any one of the preceding claims, characterized in that to obtain the soundproofing (40), the following steps are performed to heat a layer (42) of felt and a layer (44) dense soundproofing septum, arrange the layer (42) of felt and the layer (44) of dense sound-absorbing septum heated in a mold, and pressing the layer (42) of felt and the dense sound-absorbing septum layer (44) together to assemble them and locally compressing the felt layer to crush it deeply to create a local reinforcement (48). 6. Method according to any one of the preceding claims 1 to 3, characterized in that to obtain the sound-absorbing material (140) there is a layer (144) of dense sound-absorbing septum and reinforcing elements (148) in a mold of foaming, and foam is injected into the mold to form an expanded foam layer (142) including the reinforcing members (148). 7. A method according to claim 6, characterized in that during the production of soundproofing (140), there are in the mold substantially tubular studs (146) which are then incorporated in the foam during its injection so that creating passages (145) through said foam layer (142). 8. A method according to any one of claims 5 to 7, characterized in that the dense sound-absorbing septum layer (44/144) is conformed to have male means (70) for said connection with the board. edge (30). 9. Method according to any one of the claims, characterized in that, before bringing the dashboard (30) facing the separation zone (20), is fixed to the soundproofing (40/140) a platinum (50) supporting at least some of the functional elements useful for the operation of the vehicle, and these elements are passed through the soundproofing 40/140. Cockpit (100) for driving a motor vehicle comprises a vehicle structure (10), a cockpit (12), an engine compartment (14) and a separation zone (20) between the cockpit (12) and the engine compartment (14), the cockpit (100) comprising - a dashboard (30), - a soundproofing (40/140) for the soundproofing of the cockpit (12) relative to the engine compartment (14), and means (60) for attaching the dashboard (30) and soundproofing (40/140) to the separation zone (20), characterized in that the cockpit (100) further comprises means <B> (60; </ B> 49/149) connecting the dashboard (30) to the soundproofing (40/140), independently of the attachment of the dashboard (30) to the separation (20). Cockpit according to claim 10, characterized in that the board edge (30) comprises a rigid insert (35) incorporating part of the connection means (60) to the soundproofing (40/140). Cockpit according to any one of Claims 10 to 11, characterized in that the soundproofing element (40/140) comprises a first sound-absorbing layer (42/142) intended to cover the separation zone (20), a second layer sound absorbing element (44/144) connected to the first layer (42/142) and covering it at least partially, orifices (45/145) passing through the sound-absorbing material (40/140) for the passage therethrough of useful functional elements to the operation of the vehicle, substantially tubular acoustic absorbent pads (46/146) surrounding these orifices, and local reinforcement means (48/148) disposed around orifices (45/145) and / or therebetween, studs (46/146) and the reinforcement means (48/148) being separate from each other or made of the same one-piece piece. 13. Cockpit according to any one of claims 10 to 12, characterized in that the soundproofing (40) comprises a first layer (42) of felt, a second layer (44) forming a dense sound absorbing septum and sound absorbing pads (46) substantially tubular disposed around orifices (45) passing for the passage of functional elements useful for the operation of the vehicle, each stud (46) being inserted into an orifice (22) of the separation zone (20) so as to to dampen the vibrations suffered by this zone. 14. A cockpit according to claim 13, characterized in that the layer (42) felt is compressed locally around the orifices (45) at the point pads (46) and between at least some of these orifices (45) to define zones (48). ) reinforcement. A cockpit according to any one of claims 12, characterized in that the soundproofing (140) comprises a layer (142) of foam, a layer (144) forming a dense sound absorbing septum and substantially tubular acoustic absorbing pads (146) disposed around orifices (145) passing through it for the passage of functional elements that are useful for the operation of the vehicle. Cockpit according to claims 12 and 15, characterized in that the foam layer (142) includes inserts (148) which are stiffer and arranged around the orifices (145) and between at least some of them to define said means. reinforcement. 17. Cockpit according to any one of claims 16, characterized in that each stud (146) is axially surmounted joint (143) of flexible acoustic absorbent material such as an elastomer, said seal (143) being inserted into an orifice (22) of the separation zone (20) so as to damp the vibrations circulating in said zone. Cockpit according to claim 17, characterized in that the seal (143) and the pad (146) form a single piece of flexible acoustic absorbent material, an elastomer. A cockpit according to any one of claims 18, characterized in that the inserts (148) are embedded in the foam layer (142) so that they are remote and disconnected from the septum layer (144). Cockpit according to claim 19, characterized in that the stud (146) is distinct and acoustically decoupled from the insert (148) while being structurally connected thereto via a coupler (147). ) of soft acoustic absorbing material such as elastomer. 21. Cockpit according to any one of claims 20, characterized in that the layer (142) foam includes a ring (149) more rigid than surrounding each passage opening (145) of the soundproofing. 22. Cockpit according to any one of claims 21 to 21, characterized in that the septum layer (44) is acoustically disconnected from the pads (46) so that the vibrations circulating in the separation zone (20) and / or in functional elements (90) passing through the sound absorbing material (40) are damped before passing into the septum layer (44).