FR3017088A1 - FIXING BRACKET ON APRON WITH IMPROVED ACOUSTIC SEALING - Google Patents

Abstract

The present invention relates to a mounting bracket (20) for equipment intended to be fixed on an interface deck (1) between the engine compartment and the passenger compartment of a vehicle, said support comprising a shaft (21) provided with a fastening means (24) and adapted to be inserted into a cutting hole (2A) made in a soundproofing mat (2) covering said apron (1) to occupy a service configuration in which it is housed in said hole ( 2A) and wherein said fastening means (24) cooperates with a complementary means (1A) of said apron (1) so as to secure said support (20) to said apron (1), said support (20) comprising an annular flange (29). ) rooted on said barrel (21) and from the underside of which a godron (31) circulates over its entire periphery, said flange (29) being shaped so that, in said service configuration, its face lower rests against the upper face of the carpet (2) with said gadroon (31) which has penetrated into the thickness of said belt (2) all around said hole (2A).

Description

FIELD OF THE INVENTION The present invention relates generally to the field of sound comfort inside the passenger compartment of a motor vehicle. It relates in particular to the improvement of acoustic sealing at the interface deck between the engine compartment and the passenger compartment.

BACKGROUND OF THE INVENTION The reduction of the noise level prevailing inside the passenger compartment of motor vehicles is now an unavoidable problem for car manufacturers. The latter seek in particular to improve acoustic sealing at the interface deck between the engine compartment and the passenger compartment of a motor vehicle. It is thus known to house an acoustical sound-absorbing mat made of polyurethane foam between the bottom bracket and the interface deck.

However, such a soundproofing mat never completely covers the deck surface since it has a number of cutting holes intended to allow the subsequent mounting on this deck of a plurality of equipment such as a bottom channel or a electronic management box via mounting brackets each having a shaft intended to be inserted in such a cutting hole to occupy a service configuration in which it is housed and where the fastening means cooperates with a complementary means of the deck to secure the deck support. These portions of the deck not covered by the soundproofing carpet constitute passage zones allowing the sound waves from the engine block to sneak inside the cockpit and cause there aerodynamic noises or whistling harmful to the comfort of the passengers .

OBJECT AND SUMMARY OF THE INVENTION The present invention therefore aims to improve acoustic sealing at this interface deck between the engine compartment and the passenger compartment of a motor vehicle.

It proposes for this purpose a mounting bracket for a motor vehicle equipment intended to be fixed on an interface deck between the engine compartment and the passenger compartment of said vehicle, said support comprising a barrel provided with a fixing means and suitable to be inserted into a cutting hole made in a soundproofing carpet covering said apron to occupy a service configuration in which it is housed in said hole and wherein said fixing means cooperates with a complementary means of said interface deck so as to secure said support to said apron; characterized in that said support comprises an annular flange taking root on said barrel and from the lower face of which a godron circulating on the whole of its periphery protrudes, said annular flange being shaped so that, in said service configuration, its lower face rests against the upper face of said soundproofing carpet with said gadroon which has penetrated into the thickness of said soundproofing carpet all around said cutting hole. The gadroon that comprises the mounting bracket according to the invention constitutes a barrier for the sound waves emitted by the engine compartment of the vehicle in the displacement phase (motor in operation) and which manage to sneak between the underside of the collar and the top of the soundproof carpet to try to reach the cabin. The mounting bracket according to the invention thus makes it possible to improve in a particularly simple and economical way the acoustic insulation of the passenger compartment. According to preferred features of said fixing support: - said gadroon has a height of between 3 and 6 MM; said gadroon has a beveled or pointed profile so as to facilitate its penetration into said soundproofing mat; said godron has a minimum spacing of 6 mm with respect to the outer periphery of said barrel; said fixing support is obtained by molding from a thermoplastic material; said barrel comprises a body having a shape complementary to that of said cutting hole, as well as a flange extending radially inside said body; - Said fixing means consists of an opening formed in the central portion of said soleplate and intended to be traversed by a threaded stud secured to said interface deck and on which is then screwed a nut; and / or - said barrel comprises pre-holding means in position 15 of said support against said interface deck before screwing said nut. The invention also aims, in a second aspect, with a chute for guiding the path of an electric connecting beam along a motor vehicle interface deck, said chute comprising a guiding body which constitutes a reception cradle for said beam, characterized in that it comprises two such mounting brackets. According to preferred features, said bottom channel is molded in one piece. BRIEF DESCRIPTION OF THE DRAWINGS The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but without limitation, with reference to the appended drawings, in which: FIG. 1 shows a perspective view from above of a portion of an interface deck located between the engine compartment and the passenger compartment of a motor vehicle, this deck being covered with an acoustically sound-absorbing mat of polyurethane foam; - Figure 2 shows a view similar to Figure 1 after mounting on this deck of a bottom bracket via two mounting brackets according to the invention integrated in this chute; - Figure 3 shows a bottom view in perspective of the bottom bracket visible in Figure 2; FIG. 4 represents a bottom view in perspective of the first fixing support that comprises the bottom bracket of FIG. 3; - Figure 5 is a sectional and perspective view of the first fixing support in its service configuration, the section being formed along a transverse plane passing through the axis of this support; - Figure 6 shows a bottom view in perspective of the second support bracket that includes the bottom bracket; and - Figure 7 is a sectional and perspective view of the second mounting bracket in its operating configuration, the section being formed in a transverse plane passing through the axis of this support. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 shows a portion of a sheet metal interface deck 1 located between the engine compartment and the passenger compartment of a motor vehicle. As illustrated in this figure, the deck 1 is covered with a mat 2 made of polyurethane foam and intended to isolate the cabin vis-à-vis the noise emitted by the engine compartment of the vehicle. The belt 2 has cut holes 2A, 2B, 2C, 2D, 2E, 2F and 2G so as to allow the assembly on this deck 1 of a number of devices including the bottom chute 10 illustrated in Figures 2 and 3 .

This bottom chute 10 is intended to guide the path of the electrical connection beam 3 along the deck 1 so that it can not interfere with the actuation zone, which could deteriorate and cause certain malfunctions in the electrical equipment to which he is connected. To do this, the chute 10 comprises a guide body 11 in the form of a coil which constitutes a reception cradle for the beam 3. The fixing of the chute 10 on the interface deck 1 is ensured by means of two supports 20, 40 which rest against this apron 1 and are fixed (Figure 3). We will now describe in detail the first mounting bracket 20 in support of Figures 4 and 5. This mounting bracket 20 which is located at a first end of the bottom chute 10, has a cylindrical shaft 21 to be inserted during assembly of the bottom chute 10, inside the hole 2A of corresponding shape to be then fixed to the sheet metal deck 1 by means of a nut screwed onto the threaded stud 1A integral with this deck 1 ( this nut is not shown in Figure 5 showing the mounting bracket 20 in the mounted configuration of this chute 10 for ease of reading). The barrel 21 comprises a cylindrical body 22 and a sole 23 which extends radially inside the body 22 and near its circular lower end. A circular opening 24 is further provided in the central part of this sole 23, this opening 24 extending on the lower side by a cylindrical tubular wall 25 concentric with the body 22 (FIG. 4), the respective circular lower ends of the body 22 and this tubular wall 25 being further coplanar. Four radial reinforcing ribs 26 angularly distributed at 90 ° to each other, connect the body 22 and the tubular wall 25. After assembly of the bottom chute 10, the respective lower ends of the cylindrical body 22, the tubular wall 25 and reinforcement ribs 26 rest against the deck 1 (Figure 5). The barrel 21 also comprises means for pre-holding the support 20 in position against the apron 1.

These pre-holding means are constituted by four claws 27 rooted on the inner face of the tubular wall 25 and which are angularly distributed at 90 ° from each other. The four claws 27 extend radially towards the central axis of the body 22 and the tubular wall 25, so that their free inner ends delimit a circle whose diameter is slightly smaller than the diameter of the stud 1A for s' introduce through the opening 24 during the insertion of the barrel 21 inside the cutting hole 2A formed in the soundproofing carpet 2 (Figure 5). These four claws 27 are also slightly inclined upwards, so as to guide the upper end of the stud 1A. When the barrel 21 is inserted into the hole 2A, the operator in charge of mounting the chute 10 must exert an insertion force sufficient to slightly deform the claws 27 and thus allow the bolt 1A to pass through the opening 24. The drum 21 is then pre-held in the plated position against the apron 1 thanks to the retaining claws 27 which exert a clamping force on the stud 1A by wanting to resume their original configuration, the operator therefore has both hands to engage and screw the nut, which greatly facilitates these operations and also improves safety. The fixing support 20 then occupies its operating configuration, illustrated in FIG. 5, in which the drum 21 is housed in the cutting hole 2A and where the opening 24 cooperates with the stud 1A so as to secure this fixing support 20 to the interface apron 1. The fixing support 20 also comprises an annular flange 29 which takes root at the upper end of the cylindrical body 22 of the barrel 21 and extends in a slightly oblique plane with respect to the plane of its sole 23.

The flange 29 is shaped so that its lower face rests against the upper face of the soundproofing carpet 2 when the support 20 occupies its service configuration (Figure 5). The fixing support 20 further comprises a cylindrical peripheral wall 30 which takes root along the peripheral edge of the flange 29. It extends from the upper face of this flange 29 and perpendicular thereto, towards the body of the flange 29. chute 11 on which it opens. Opposite this cylindrical peripheral wall 30 and in its extension, the fixing support 20 comprises a gadroon 31 protruding from the lower face of the flange 29, and which circulates over its entire peripheral edge. This peripheral gadget 31, the cross section of which is U-shaped, penetrates into the thickness of the soundproofing mat 2 all around the cutting hole 2A during the insertion of the blank 21 into this hole 2A to bring it into its configuration. service (figure 5). During the vehicle movement phase (engine running), the sound waves coming from the engine compartment that sneak between the underside of the flange 29 and the upper face of the soundproofing mat 2 to reach the passenger compartment, abut against this peripheral gadroot 31 which constitutes a barrier imprisoning them. The presence of this godron 31 thus significantly improves the acoustic insulation of the passenger compartment. The godron 31 preferably has a height of between 3 and 6 mm so that the latter penetrates deep enough into the soundproofing mat to provide excellent acoustic sealing. On the other hand, in order to take into account the centering tolerances between the stud 1A and the cutting hole 2A, and to be sure that the godron 31 is well located on all of its periphery facing a solid zone of the 2 during the insertion of the barrel 21 in the hole 2A, this godron 31 has a minimum spacing of 6 mm from the outer periphery of the body 22 of the barrel 21. The fastening support 20 is obtained by molding from a thermoplastic material such as polypropylene (PP) optionally loaded with mineral fibers (PP-TD type or PP-MD for example). We will now describe in detail the second attachment support 40 in support of Figures 6 and 7.

This mounting bracket 40 which is located near the second end of the bottom chute 10, comprises an oblong cylindrical shaft 41 intended to be inserted, during assembly of the bottom chute 10, inside the hole 2B of corresponding shape to be then fixed to the sheet metal deck 1 by means of a nut screwed onto the threaded stud 1B integral with this deck 1 (this nut not being shown in FIG. 7 representing the fixing support 40 in the mounted configuration of this chute 10 for ease of reading). The shaft 41 which has a height much smaller than the shaft 21, comprises an oblong cylindrical body 42 and a flange 43 which extends radially inside the body 42 from its upper end. A rectangular opening 44 is further provided in the central part of this sole 43, this opening 44 extending from the lower side by a rectangular tubular wall 45 concentric with the body 42 (FIG. 6), the respective lower ends of the body 42 and this tubular wall 45 being further coplanar. Four radial reinforcing ribs 46 connect the body 22 to each of the four corners of the rectangular tubular wall 45.

After assembly of the bottom chute 10, the respective lower ends of the oblong cylindrical body 42, the rectangular tubular wall 45 and the reinforcing ribs 46 rest against the deck 1 (Figure 7). The drum 41 also comprises means for pre-holding the support 40 in position against the apron 1. These pre-holding means consist of two tabs 47 rooted along the inner face of each of the long sides of the tubular wall. rectangular 45, and which extend facing each other towards the median longitudinal plane of this wall 45.

Their free internal ends thus delimit a rectangle whose width is slightly less than the diameter of the pin 1B intended to be introduced through the opening 44 during the insertion of the shaft 41 inside the cutting hole 2B made in the soundproof mat 2 (Figure 7). These two tabs 47 are also slightly inclined upwards, so as to guide the upper end of the stud 1B. It will be noted that the fact that the insertion opening 44 is rectangular makes it possible to overcome the positioning tolerances of the two studs 1A and 1B relative to one another. When the barrel 41 is inserted into the hole 2B, the operator in charge of mounting the chute 10 must exert an insertion force sufficient to slightly deform the tabs 47 and thus allow the bolt 1B to pass through the opening 44. .

The shaft 41 is then pre-held in the plated position against the deck 1 thanks to the tabs 47 which exert a clamping force on the stud 1B in wanting to resume their original configuration, the operator therefore has both hands to engage and screw the nut, which greatly facilitates these operations and also improves safety.

The fixing support 40 then occupies its operating configuration, illustrated in FIG. 7, in which the drum 41 is housed in the cutting hole 2B and in which the opening 44 cooperates with the stud 1B so as to secure this fastening support. 40 to the interface apron 1. The fixing support 40 also comprises an annular flange 49 which takes root at the upper end of the oblong cylindrical body 42 of the barrel 41 and extends in the extension of the sole 43. The flange 49 is shaped so that its lower face rests against the upper face of the soundproofing mat 2 when the fixing support 40 occupies its service configuration (FIG. 7). The fixing support 40 further comprises an oblong cylindrical peripheral wall 50 which takes root along the peripheral edge of the flange 49. It extends from the upper face of this flange 49 and perpendicular thereto, in the direction of the flange 49. chute body 11 on which it opens. Opposite this oblong cylindrical peripheral wall 40 and in its extension, the fixing support 40 comprises a gadroon 51 projecting from the lower face of the flange 49, and which circulates over its entire peripheral edge.

This peripheral gadget 51, the cross section of which is U-shaped, penetrates into the thickness of the soundproofing mat 2 all around the cutting hole 2B when the futon 41 is inserted into this hole 2B to bring it into its configuration. service (Figure 7).

In phase of movement of the vehicle (engine running), the sound waves from the engine compartment and sneaking between the underside of the flange 49 and the upper face of the soundproofing mat 2 to reach the passenger compartment, abut against this peripheral gadroot 51 which constitutes a barrier imprisoning them. The presence of this godron 51 thus significantly improves the acoustic insulation of the passenger compartment. Like the godron 31, the godron 51 preferably has a height of between 3 and 6 mm so that the latter penetrates deep enough in the soundproofing mat to provide excellent acoustic sealing. On the other hand, in order to take into account the centering tolerances between the stud 1B and the cutting hole 2B, and to be sure that the godron 51 is well located on all of its periphery facing a solid zone of 2 during the insertion of the barrel 41 into the hole 2B, this godron 51 has a minimum spacing of 6 mm from the outer periphery of the body 42 of the barrel 41. The fixing bracket 40 is also obtained by molding to from a thermoplastic material such as polypropylene (PP) optionally filled with mineral fibers (of PP-TD or PP-MD type, for example). Preferably, the chute 10 and the two supports 20, 40 that it comprises have integrally molded from this thermoplastic material. According to alternative embodiments not shown, the fastening support according to the invention is associated with other equipment of the vehicle to be fixed to the deck 1, such as the electronic management box. According to other embodiments not shown, the cross section of the godron has a different profile, for example a beveled profile or tip so as to facilitate its penetration into the soundproofing carpet. According to still other embodiments not shown, the shape and dimensions of the various elements constituting these mounting brackets are different. Of course, the present invention is not limited to the embodiments described and shown, but it encompasses any alternative embodiment within the reach of those skilled in the art.

Claims (10)

REVENDICATIONS1. Fixing support for a motor vehicle equipment (10) intended to be fixed on an interface plate (1) between the engine compartment and the passenger compartment of said vehicle, said support comprising a shaft (21; 41) provided with a fastening means (24; 44) and adapted to be inserted into a cutting hole (2A; 2B) formed in a soundproofing mat (2) covering said apron (1) to occupy a service configuration in which it is housed in said hole (2A; 2B) and wherein said fixing means (24; 44) cooperates with complementary means (1A; 1B) of said interface board (1) so as to secure said support to said apron (1); characterized in that said support comprises an annular flange (29; 49) rooted on said barrel (21; 41) and from the lower face of which a godron (31; 51) circulates on the whole of its periphery, said annular flange (29; 49) being shaped so that, in said service configuration, its lower face rests against the upper face of said soundproofing mat (1) with said gadroon (31; 51) which has penetrated into the thickness of said mat soundproofing (2) all around said cutting hole (2A; 2B). 2. Fixing bracket according to claim 1, characterized in that said gadroon (31; 51) has a height of between 3 and 6 mm. 3. Fixing bracket according to one of claims 1 or 2, characterized in that said gadroon (31; 51) has a beveled profile or tip so as to facilitate its penetration into said soundproofing mat (2). 4. Fixing bracket according to one of claims 1 to 3, characterized in that said gadroon (31; 51) has a minimum spacing of 6 mm relative to the outer periphery of said barrel (21; 41). 5. Fixing support according to one of claims 1 to 4, characterized in that said fixing support is obtained by molding from a thermoplastic material. 6. Fixing support according to one of claims 1 to 5, characterized in that said shaft (21; 41) comprises a body (22; 42) having a shape complementary to that of said cutting hole (2A; 2B), and a sole (23; 43) extending radially inside said body (22; 42). 7. Support bracket according to claim 6, characterized in that said fixing means consists of an opening (24; 44) formed in the central portion of said sole (23; 43) and intended to be traversed by a threaded stud (1A 1B) secured to said interface board (1) and on which is then screwed a nut. 8. Support bracket according to claim 7, characterized in that said shaft (21; 41) comprises means for pre-holding in position (27; 47) of said support against said interface deck (1) before screwing said nut. 9. Bottom chute intended to guide the path of an electric connecting beam (3) along an interface deck (1) of a motor vehicle, said chute comprising a guide body (11) which constitutes a cradle reception device for said beam (3), characterized in that it comprises two attachment supports (20, 40) according to one of claims 1 to 8. 10. Bottom chute according to claim 9, characterized in that it came integrally molding.