Automobiles with improved sound transmission systems in the passenger compartment

Abstract

To provide an improved sound transmission assembly that reduces the attenuation of sound transmitted to the crew compartment relative to the original sound, and increases the similarity of sound transmitted to the crew compartment relative to the original sound. [Solution] The automobile is characterized by comprising an engine, an engine compartment, an occupant compartment, a firewall, an interior trim panel, a compartment between the trim panel and the firewall, and a sound transmission duct having an inlet in the engine compartment, extending along a first axis in accordance with at least one distribution portion until it divides at a dividing node to an unconnected branch section, and further comprising lateral ducts having connecting portions that connect to the branch sections, each having a configuration that extends along a second axis parallel to the diverging portion, from a connecting portion to discharge into a second through-opening in the trim panel, which communicates with the occupant compartment.

Description

Technical Field

[0001] Cross-Reference to Related Applications This patent application claims priority from Italian Patent Application No. 102025000006762 and Italian Patent Application No. 102025000006771, both filed on March 31, 2025, the entire disclosures of which are incorporated herein by reference.

[0002] The present invention relates to motor vehicles, and more particularly to a sound transmission assembly for transmitting sound generated inside an engine compartment of a motor vehicle through a firewall of the motor vehicle toward a passenger compartment of the motor vehicle.

Background Art

[0003] As is known, the engine compartment of a motor vehicle is separated from the passenger compartment by a chassis wall referred to as a firewall.

[0004] Generally, in the motor vehicle sector, particularly in the sports car sector, there is a recognized need for the sound generated by the engine installed in the engine compartment to be perceived by the driver as realistically as possible, so as to increase the driving pleasure of the driver.

[0005] The firewall inevitably constitutes an element that impedes the transmission of sound from the engine compartment to the passenger compartment, so that the sound actually perceived in the passenger compartment results in a reduced intensity relative to the original sound, for example across the entire frequency spectrum of the original sound generated by the engine in the engine compartment.

[0006] For this reason, some motor vehicles are provided with a sound transmission assembly or sound transmission system that includes one or more ducts, which start from the engine compartment to receive sound at an inlet and terminate at one or more openings in an interior trim panel that directly faces the passenger compartment on one side and faces the firewall on the other side.

[0007] The interior trim panels and firewalls enclose the compartment between them, and this compartment is further interposed between the engine compartment and the occupant compartment.

[0008] The duct extends within the compartment, passing through the firewall and terminating at an opening in the interior trim panel.

[0009] For example, the applicant's previous solution, shown in Figure 13, provides an inlet pipe 101 that extends through a firewall to terminate inside a compartment 102 defined between a firewall (not shown) and an interior trim panel 103, only the side facing the firewall is visible.

[0010] The inlet pipe 101 has a cross-section with a substantially constant area along its longitudinal axis and discharges into a free volume 104 defined by a single bell-shaped casing 105.

[0011] When the cross section of the inlet pipe 101 is cut at the end where it is discharged in the free volume 104 by the end-intersecting plane, the area of ​​the end cross section of the inlet pipe 101 is much smaller than the area of ​​the free volume 104 belonging to the same end-intersecting plane.

[0012] The free volume 104 communicates with two through-openings 106 in an interior trim panel 103, which are intended to communicate with the passenger compartment of the vehicle.

[0013] In this method, the sound generated in the engine compartment can pass through the inlet pipe 101, the free volume 104, and the through-opening 106 in this sequential order to the crew compartment.

[0014] Nevertheless, while this may allow the sound to bypass the firewall, the sound in the crew compartment arrives at a certain weakened intensity compared to the original sound, and this weakening may be noticeable for certain frequencies in the frequency spectrum of the original sound.

[0015] Therefore, there is a need to provide an improved sound transmission assembly, particularly in terms of reducing the attenuation of sound transmitted to the crew compartment relative to the original sound, and increasing the similarity of the sound transmitted to the crew compartment relative to the original sound. [Overview of the project] [Problems that the invention aims to solve]

[0016] The objective of the present invention is to satisfy the aforementioned needs, preferably in a simple and reproducible manner. [Means for solving the problem]

[0017] The objective is achieved by an automobile as defined in claim 1.

[0018] The dependent claims define specific embodiments of the present invention.

[0019] Embodiments of the present invention are described below with reference to the accompanying drawings, using non-limiting examples, for a better understanding of the invention. [Brief explanation of the drawing]

[0020] [Figure 1] This is a perspective view of an automobile according to the present invention, with parts made transparent for clarity. [Figure 2] This diagram is similar to Figure 1, but with the roof of the car removed for clarity. [Figure 3] This is an enlarged perspective view of the rear window area of ​​a car, on the side of the passenger compartment. [Figure 4] This is a rear perspective view of the region shown in Figure 3, where the sound transmission assembly of the automobile is made visible. [Figure 5] Figure 4 is a perspective cross-sectional view of the sound transmission assembly, following a cutting plane perpendicular to the direction of the vehicle's forward movement. [Figure 6] This is a flat cross-sectional view following the cutting plane of Figure 5. [Figure 7]This is a diagram of a sound transmission assembly arranged in a plan view of a motor vehicle whose outline is almost entirely transparent. [Figure 8] This is a diagram showing a test apparatus for carrying out a sound level experiment, in which the frequency spectrum of sound coming from the same source and passing through respective ducts is measured. [Figure 9] This is a diagram showing a test apparatus for carrying out a sound level experiment, in which the frequency spectrum of sound coming from the same source and passing through respective ducts is measured. [Figure 10] This is a sound frequency-intensity graph representing frequency spectra respectively associated with measurements performed by the test apparatuses of Fig. 8 and Fig. 9. [Figure 11] This is a comparative diagram in a sound frequency-intensity graph between the frequency spectrum of sound perceived in the passenger compartment of a motor vehicle according to the present invention and the frequency spectrum of sound perceived in the passenger compartment of a motor vehicle according to the previous solution by the present applicant. [Figure 12] This is a perspective cutaway view of a portion of the sound transmission assembly of Fig. 4, taken along a horizontal cutting plane. [Figure 13] This is a diagram similar to Fig. 4, but showing a sound transmission assembly for a motor vehicle according to the previous solution by the present applicant. DETAILED DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0021] In Fig. 1, reference numeral 1 is used to designate the motor vehicle as a whole.

[0022] The motor vehicle 1 has a roll axis X or a longitudinal axis extending along the forward traveling direction of the motor vehicle 1.

[0023] Furthermore, the motor vehicle 1 has a horizontal pitch axis Y orthogonal to the roll axis X.

[0024] Furthermore, the motor vehicle 1 has a yaw axis Z orthogonal to both axes X and Y. The yaw axis Z has at least one vertical component, that is, at least one component oriented in the direction of gravity.

[0025] Automobile 1 comprises a main body 2, which further comprises a chassis 3 that defines the load-bearing structure or frame of automobile 1, and a body 4 supported by the chassis 3 that defines the outer surface of automobile 1.

[0026] The main body 2 defines the passenger compartment 5, which can be used by the driver and, optionally, one or more passengers.

[0027] The occupant compartment 5 is preferably positioned between two compartments, at least one of which is the engine compartment 6 of the vehicle, along a roll axis X, where the engine compartment 6 is specifically positioned later than the occupant compartment 5. The other compartment, which is optional and therefore not shown, may be a trunk for containing objects of various natures.

[0028] Automobile 1 is equipped with at least two wheels 7, which are drive wheels aligned according to axis Y. More precisely, although not mandatory, of the wheels 7, the two rearmost wheels aligned with the roll axis X are the drive wheels.

[0029] Automobile 1 generally comprises a propulsion assembly with at least one engine 8, specifically an endothermic or internal combustion engine, and a mechanical transmission (not shown) configured to transmit the output from the engine 8 to the drive wheels among the wheels 7.

[0030] The engine 8 is housed in the engine compartment 6. For example, the engine 8 is supported within the engine compartment 6 by the chassis 3, more specifically by being suspended from the chassis 3, and more specifically by using suspension elements of a known type, which are therefore not shown.

[0031] More specifically, the engine 8 comprises an intake manifold 9 and an exhaust manifold 10.

[0032] The propulsion assembly may include intake piping 11 to supply, for example, air, specifically compressed air, to the intake manifold 9, and similarly, it may include exhaust piping 12 to discharge exhaust gas from the exhaust manifold 10.

[0033] The propulsion assembly may include a turbocharger 13 that not only forms part of the exhaust piping 12 and has a turbine adapted to extract work from the exhaust gas, but also forms part of the intake piping 11 and has a compressor that is operated by the work extracted from the turbine to compress the air supplied to the intake manifold 9.

[0034] The intake piping 11 is configured to carry air from the environment outside the vehicle toward the compressor inlet so that the compressor provides compressed air at the outlet and to provide compressed air from the compressor toward the intake manifold 9.

[0035] The exhaust piping 12 is configured to carry exhaust gas from the exhaust manifold 10 to the turbine inlet so that the turbine can extract work from the exhaust gas in order to operate the compressor.

[0036] Downstream of the turbine, the exhaust piping 12 may include an aftertreatment device 14 configured to process the exhaust gases leaving the turbine before releasing them into the external environment.

[0037] Automobile 1 is provided with a firewall 15, that is, a wall defining the longitudinal (according to axis X) end region of the engine compartment 6, which in this case is the front longitudinal end region.

[0038] Furthermore, the automobile 1 includes, for example, an interior trim panel 16 positioned to cover the firewall 15 from the inside of the passenger compartment 5.

[0039] The interior trim panel 16 specifically has a first surface 17 that faces directly toward the occupant compartment 5 (in other words, the surface 17 is exposed to the inside of the occupant compartment 5).

[0040] Furthermore, the interior trim panel 16 specifically has a thickness along axis X, and the degree of thickness of the interior trim panel 16 is more preferably much smaller than the degree of the same interior trim panel 16 according to the dimensions of width (along axis Y) and height (along axis Z).

[0041] The interior trim panel 16 also has a second surface 18 opposite to the first surface 17, in the direction of its thickness, specifically along axis X.

[0042] The second surface 18 faces the firewall 15.

[0043] Therefore, the firewall 15 is specifically positioned between the engine compartment 6 and the interior trim panel 16 (more precisely, the second surface 18) along axis X.

[0044] Therefore, the automobile 1 has a compartment 21 that is at least partially defined or demarcated between the interior trim panel 16 (more precisely, the second surface 18) and the firewall 15, specifically according to axis X.

[0045] The compartment 21 is defined or demarcated by the interior trim panel 16, or more precisely by the second surface 18, and / or by the firewall 15 (specifically, on one side along axis X), at least partially (specifically, on the other side along axis X).

[0046] In this method, the firewall 15 specifically separates or divides compartment 21 from engine compartment 6 along axis X. The separation along axis X may be merely conceptual, that is, not necessarily whole or sealed; in other words, compartment 21 can communicate with engine compartment 6 not only using holes or openings passing through the firewall 15, but also using slits at the edges of the firewall 15.

[0047] Preferably, the interior trim panel 16 defines the occupant compartment 5 at the rear.

[0048] Specifically, the interior trim panel 16 is positioned below the rear window 19 of the automobile 1, and further positioned below the roof 20 of the automobile 1.

[0049] Similar to the interior trim panel 16, the rear window 19 defines the occupant compartment 5 at the rear.

[0050] The automobile 1 further includes a sound transmission assembly to transmit sound generated inside the engine compartment 6 to the occupant compartment 5 through the firewall 15. The sound transmission assembly includes a sound transmission duct 22 having an inlet 23 in the engine compartment 6 to receive one or more sound pressure waves, i.e., one or more sounds.

[0051] Sound is a pressure wave that propagates in the air, and therefore can be guided through the air present in the sound transmission duct 22.

[0052] In the illustrated embodiment, the inlet 23 is conveniently connected to two sound transmission pipes 24, 25, which are configured to supply sound pressure waves to the inlet 23 by generating sound pressure waves starting from harmonic forces generated by the operation of the engine 8 or propulsion assembly, and / or by transmitting sound pressure waves directly generated by the operation of the engine 8 or propulsion assembly.

[0053] For example, more specifically, the sound transmission piping 24 includes a duct 26 that communicates with the intake piping 11 downstream of the compressor to guide compressed air to a resonant device 27 of the sound transmission piping 24. Furthermore, the sound transmission piping 24 includes a further duct 28 that connects the resonant device 27 to the inlet 23. The resonant device 27 includes a deformable element (not shown) that fluidly isolates the ducts 26 and 28 from each other, the deformable element comprising, for example, a membrane or diaphragm, and is arranged to vibrate with respect to the compressed air in the duct 26, thereby stimulating the generation of sound pressure waves in the duct 28 so that sound pressure waves propagate through the duct 28 and reach the inlet 23. Thus, the harmonic force here consists of the pressure in the air compressed by the compressor.

[0054] In a similar approach, for example, the sound transmission piping 25 includes a duct 29 communicating with the exhaust piping 12 downstream of the turbine and upstream of the aftertreatment device 14, so as to guide the expanded exhaust gas from the turbine to the resonant device 30 of the sound transmission piping 25. Thus, the sound transmission piping 25 includes a further duct 31 connecting the resonant device 30 to the inlet 23. The resonant device 30 includes a deformable element (not shown) that fluidly isolates the ducts 31 and 29 from each other, the deformable element being, for example, a membrane or diaphragm, which vibrates due to the turbulence of the exhaust gas in the duct 29, thereby stimulating the generation of sound pressure waves in the duct 31 so that sound pressure waves propagate through the duct 31 and reach the inlet 23. Thus, the harmonic force here consists of the turbulence of the exhaust gas in the duct 29.

[0055] The sound transmission pipes 24 and 25 may have structures different from those described using non-limiting examples, and for the purposes of the present invention, the inlet 23 is configured to receive such sound pressure waves regardless of the source of the sound pressure waves, so the sound transmission pipes 24 and 25 may be omitted. In other words, the inlet 23 can pick up sound from inside the engine compartment 6, that is, it can receive sound pressure waves generated in the engine compartment 6.

[0056] The sound transmission duct 22 generally has the function of transmitting sound pressure waves received from the inlet 23 to the crew compartment 5.

[0057] The sound transmission duct 22 has at least one distribution portion 32 that extends along axis K, starting from the inlet 23, for example, in a curve or straight line.

[0058] Preferably, the distribution portion 32 starts from the inlet 23, extends partially along the axis K inside the engine compartment 6, extends partially within the compartment 21, and thus passes through the firewall 15 in a penetrating manner, i.e., passes through the firewall 15.

[0059] Axis K has at least one longitudinal component, that is, a non-zero projection in the roll axis X. For example, within section 21, axis K may have a straight section, and more specifically, a section parallel to axis X. More broadly, axis K in section 21 has at least one longitudinal extension following axis X, that is, it extends longitudinally along axis X. This does not mean that axis K is perfectly straight and / or perfectly parallel to axis X in section 21, but rather that axis K has at least one component parallel to axis X, that is, a non-zero projection in axis X.

[0060] The sound transmission duct 22 divides into several (i.e., at least two) uncoupled branch sections 34 at or just downstream of the end of the distribution section 32. Thus, along axis K, the end of the distribution section 32 opposite the inlet 23 defines division nodes where the branch sections 34 extend or unfold along or parallel to each other and parallel to the respective branch axes W.

[0061] For example, the expression "unconnected" means that there is no common volume, and therefore the intersection of the unconnected branch 34 is empty. In other words, for example, if the branch 34 are not connected to each other using the distribution section 32, they are essentially not in communication or are essentially isolated from each other.

[0062] Downstream of the division node, or more precisely, immediately downstream of the division node, the inner and / or outer walls (more broadly, each wall) of the branch 34 separate from each other so as to be completely separated or unconnected from one another.

[0063] In reality, the branch section 34 is either another pipe that connects or merges at the division node, or forms a connection in place, for example, as defined by the division node. In practice, the pipes separate from each other at the division node and form or follow a curve that moves away from the distribution section 32 in a different direction, and are further defined by yet another pipe.

[0064] From this point forward, expressions such as "upstream of ~" and "downstream of ~" are understood to refer to the direction of propagation of sound pressure waves along the sound transmission duct 22 from the entrance 23 to the crew compartment 5.

[0065] The branch section 34 extends at least partially, and more preferably, throughout the entire section 21, along the branch axis W.

[0066] More specifically, for example, the sound transmission duct 22 branches into two branching sections 34.

[0067] The branching portion 34 begins at the dividing node, terminates at the diverging portion 35, and further extends along axis W to discharge into one or more through-openings 36, specifically two through-openings 36, of the interior trim panel 16.

[0068] The through-opening 36 communicates (specifically, directly) with the crew compartment 5. In other words, the through-opening 36 may be exposed inside the crew compartment 5.

[0069] Preferably, the through-opening 36 faces upward (according to the yaw axis) and / or is obtained at the upper end 37 of the interior trim panel 16. Specifically, the through-opening 36 is positioned in a manner symmetrical with respect to the vertical central plane (plane of axes X, Z) of the automobile 1. In an example not shown, the through-openings 36 may be continuous with each other along axis Y so as to form a single opening resulting from the joining of the through-openings 36 together. Optionally, the through-opening 36 is engaged by a grille (not shown) or similar interior trim element that has the function of occupying the area of ​​the through-opening 36 while allowing air evaporation.

[0070] Preferably, the upper end 37 of the interior trim panel 16 constitutes or provides a base for the rear window 19, so that the through-opening 36 is positioned in the rear window 19 (specifically, along axis Z), i.e., more precisely, at the height of the lower end of the rear window 19 along axis Z.

[0071] Alternatively, the through-opening 36 faces the roof 20 and / or the rear window 19.

[0072] Preferably, the axis W in the through-opening 36 is perpendicular or parallel to the axis Z. In other words, the axis W points upward in the through-opening 36.

[0073] Preferably, axis W has at least two segments that extend laterally with respect to axis K, that is, along axis Y, or in a plane parallel to the planes of axes Y and Z.

[0074] Conveniently, along axis Y, the through-opening 36 is positioned at least partially, or more preferably entirely, within the first quarter of the total width of the interior trim panel 16 (along axis Y) from the vertical central plane.

[0075] The diverging portion 35 has a configuration that diverges progressively along the associated axis W toward or until it terminates at the through-opening 36, and specifically has a configuration that diverges in the narrow sense (a configuration that does not diverge in the narrow sense but diverges in some way can provide a region with a certain area, excluding at least one or more regions that diverge in the narrow sense, for example, between regions that diverge in the narrow sense).

[0076] Upstream of the divergent portion 35, the branching portion 34 preferably has no further divergent portions, or in other words, the remaining portion of the branching portion 34 has a convergent configuration toward the divergent portion 35 according to the relevant axis W (the convergent configuration can provide a region with a certain area except for at least one or more strictly converged regions, such as between strictly converged regions), and / or with a certain area overall.

[0077] Here, the expression "a certain area" as mentioned above refers to the area of ​​the cross-sectional area or orthogonal area relating to the axis W.

[0078] In the divergent configuration, the area of ​​the cross-section of the axis W or the area orthogonal to the axis W increases or increases, while in the convergent configuration, the area of ​​the cross-section of the axis W or the area orthogonal to the axis W decreases or decreases.

[0079] The expression "gradual" refers to the fact that the area of ​​the cross-section of the axis W related to the axis W, or the area perpendicular to the axis W related to the axis W, increases gradually, that is, without abrupt changes, meaning that the increase in area mathematically satisfies the leadability condition.

[0080] The presence of the divergent portion 35 is advantageous for reducing sound intensity loss in the crew compartment.

[0081] The graph in Figure 10 relates to an experiment conducted by the applicant to demonstrate what is stated in the paragraph above. Figure 10 is a graph plot of the frequency spectrum (sound frequency-intensity graph) measured using microphones M downstream of ducts C and V, respectively, as shown in the relevant Figures 8 and 9, for sounds emitted with specific properties from sound sources S immediately upstream of ducts C and V.

[0082] In Figure 10, the horizontal axis (frequency axis) of the graph represents the frequency value in Hertz (Hz), while the vertical axis (sound intensity or amplitude A-axis) of the graph in Figure 10 represents the sound intensity or amplitude value in decibels (dB) associated with the corresponding frequency.

[0083] In Figure 10, the piping associated with higher intensities (expressed in dB) starting at frequencies above 200 Hz represents the frequency spectrum of sound transmitted through duct V, while the other piping associated with considerably lower intensities across most frequencies represents sound transmitted through duct C.

[0084] Duct C has a configuration that includes a certain area, and therefore, the change in cross-section at the outlet position where microphone M is located is more abrupt than in the case of duct V with a divergent configuration, specifically in the case of duct V that is divergent in the narrow sense.

[0085] Therefore, the configuration of duct C generates greater sound intensity loss downstream of duct C compared to the case of duct V.

[0086] The branch section 34 has a connecting end 38 that connects to the distribution section 32 at the division node, and therefore, more specifically, the diverging section 35 determines the opposite end of the branch section 34 relative to the connecting end 38 according to the relevant axis W.

[0087] The connecting end 38 (Figure 12) begins at a dividing node with a cross section or orthogonal region relating to axis W. In other words, the latter cross section is the first region of the connecting end 38, i.e., the entrance region of the connecting end 38 or branch 34.

[0088] Therefore, such areas, which can be called branching areas, are in direct communication with the distribution section 32, or also form a part of the distribution section 32, that is, they define a common boundary or limit between the distribution section 32 and the branching section 34.

[0089] The branching area, and preferably all cross-sections of the connecting end 38, or more broadly, all cross-sections of the branching portion 34 with respect to the associated axis W, are, for example, circular or rectangular, that is, more broadly, elliptical or polygonal, and are preferably closed.

[0090] Conveniently, such branching areas intersect with the cross-section or orthogonal area of ​​the distribution portion 32 with respect to axis K, or more specifically, are coplanar with the cross-section or orthogonal area of ​​the distribution portion 32.

[0091] The distribution portion 32 is interrupted at the dividing node, and therefore the cross-section of the distribution portion 32 at the dividing node determines the end area of ​​the distribution portion 32.

[0092] The branching area is defined by the area of ​​each branch.

[0093] For example, the branch area is coplanar with the terminal area; that is, the branch area and the terminal area belong to the same cutting plane that is perpendicular to axis K (crossing or perpendicular to axis X), and specifically perpendicular to the end position of axis W. In other words, the branch area or branch region is each a subset of the terminal area or cross-section of the distribution portion 32 at the division node. Similarly, in other words, the branch region is each included by the terminal area, or specifically forms a part of the terminal area in the region plane.

[0094] Advantageously, the branching area (i.e., the dimensions of the area of ​​the branching region) is smaller than or nearly equal to the terminal area (i.e., the dimensions of the cross-sectional area of ​​the distribution portion 32 at the branching node with respect to axis K).

[0095] Alternatively or additionally, the branch 34 may extend along axis W in a fixed area, i.e., a fixed area of ​​the cross-section or orthogonal area of ​​the branch 34 with respect to axis W, from the dividing node to the beginning of the diverging portion 35 (i.e., to the first cross-section or orthogonal area with respect to axis W), or to the cross-section immediately upstream of the diverging portion 35, or more broadly, in a converging configuration along axis W (from the dividing node toward the beginning of the diverging portion 35), and optionally, in a narrowly converging configuration (the converging configuration may provide a region with a fixed area, excluding at least one or more narrowly converging regions).

[0096] More broadly, each branch 34 can extend, with a certain cross-section or convergent configuration, to the beginning of the main branch portion of the branch 34 (specifically, the diverging portion 35), that is, to the downstream portion with a configuration that diverges (for example, in the narrow sense) along the axis W toward the through opening 36. In fact, according to embodiments not shown, each branch 34 may independently have further branch portions with a configuration that diverges (for example, in the narrow sense) upstream of the diverging portion 35, that is, between the division node and the diverging portion 35. Here, each branch 34 has a certain area or section with a convergent configuration that connects the relevant branch portions with diverging configurations to the division node.

[0097] In this method, the sound pressure wave transmitted through the dividing node at the branching section 34 does not undergo free expansion at least up to the diverging section 35 or the aforementioned branching section, so as to minimize sound intensity loss.

[0098] Specifically, the connection terminal 38 extends in a certain area or in a convergent configuration.

[0099] Preferably, the axis W has a chamfered arc W' at the connecting end 38. In other words, the connecting end 38 extends along the chamfered arc W', that is, it has the chamfered arc W' as its own axis. The chamfered arcs W' are connected at their endpoints on the axis K. In other words, all the chamfered arcs W' begin tangentially to the axis K from the endpoints of the axis K (actually, the endpoints that define the division nodes), and divide from each other at the division nodes, specifically ending with each end transverse or perpendicular to the axis K. At the division nodes, the chamfered arcs W' are tangent to the axis K.

[0100] Specifically, the chamfered arc W' creates curves in section 21, more specifically in the planes of axes X and Y, i.e., planes parallel to the horizontal plane. For example, the curves created by the chamfered arc W' are directed at least initially from the division node along axis X, or starting from axis K and proceeding along axis Y, or transverse to axis K (i.e., moving away from axis K in each direction transverse to axis K), specifically toward the respective lateral ends 16a, 16b of the interior trim panel 16, more specifically toward the opposite lateral ends along axis Y.

[0101] More precisely, the inner wall of the connecting portion 38, that is, the wall that actually defines the inside of the connecting portion 38, follows the contour of the chamfered arc W' in the axial direction.

[0102] Downstream of the chamfered arc W', axis W preferably continues in a plane parallel to the plane of axes Y and Z, i.e., a perpendicular plane.

[0103] The branch 34 may preferably extend in a certain or more broadly converging area, and optionally in a narrowly converging area, at least along the chamfered arc W'.

[0104] Preferably, the axis W (or possibly just one of the axes W) is curved and has one or more inflection points F, i.e., points where a change occurs in the orientation of the curvature of axis W.

[0105] For example, the first inflection point F (Figure 12) may be the opposite end of one of the chamfered arcs W' with respect to the division node. At least one or two other inflection points F (Figure 6) may be downstream of the chamfered arc W'.

[0106] By using the inflection point F, the branching section 34 unfolds in a wavy or meandering manner along the axis W, while maintaining a small bulkiness along the axis Y, so that the length of the branching section 34 along the axis W can be increased.

[0107] Conveniently, the lateral ends 16a and 16b are provided with lateral through-openings 40 that communicate with the occupant compartment 5, specifically with their respective lateral end regions. The lateral openings 40 communicate with the occupant compartment 5 (specifically, directly). In other words, the lateral openings 40 may be exposed inside the occupant compartment 5. The fact that the openings 40 are lateral and belong to the lateral ends 16a and 16b is not strictly necessary in some embodiments, and therefore, more broadly, the openings 40 may be merely additional to the through-openings 36 (essentially a second through-opening 40 excluding the first through-opening 36), communicating with the occupant compartment 5 in some way, specifically directly, while more broadly forming part of the interior trim panel 16.

[0108] For example, the lateral opening 40 is defined at least in part by the lateral limit edges of the lateral ends 16a and 16b, which follow the axis Y.

[0109] The through-opening 36 is positioned between the lateral openings 40 (specifically, completely or as a whole) according to the pitch axis Y.

[0110] For example, the lateral openings 40 are aligned with each other along axis Y.

[0111] More precisely, along axis Y, the lateral opening 40 is positioned at least partially, or more preferably entirely, in the last quarter of the total width of the interior trim panel 16 (along axis Y) from the vertical central plane.

[0112] Preferably, the lateral opening 40 is positioned further down along axis Z than the through opening 36. Specifically, the lateral opening 40 is positioned symmetrically with respect to the vertical central plane. Optionally, the lateral opening 40 is engaged by a grille (not shown) or similar interior trim element that has the function of occupying the area of ​​the lateral opening 40 while allowing air evaporation.

[0113] Each vehicle 1 specifically includes a lateral duct 41 having a connection portion 42 that connects to a branching portion 34, with a configuration parallel to the diverging portion 35.

[0114] In other words, the lateral duct 41 connects to the branch section 34 upstream of the diverging section 35, for example at a connection node, and from there, the diverging section 35 and the connection section 42 start parallel to each other.

[0115] The lateral ducts 41 extend along their respective axes H, starting from the connection portion 42 or from the connection portion 42, until they are discharged at the lateral openings 40.

[0116] Specifically, the lateral duct 41 extends along axis H until it terminates at the diverging portion 43, and further extends along axis H until it is discharged at the lateral opening 40.

[0117] The diverging portion 43 has a diverging configuration that follows the associated axis H, and specifically diverges in the narrow sense toward or until it terminates at the lateral opening 40.

[0118] Preferably, in the lateral opening 40, axis H has at least one component parallel to axis X, that is, it has a non-zero projection in axis X.

[0119] For example, each diverging portion 43 is preceded by a portion 44 having a certain area, and further preceded by a further diverging portion 45 having a configuration that diverges (specifically, in a narrow sense) toward each portion 44.

[0120] Conveniently, the length of the lateral duct 41 along axis H is different from (specifically, smaller than) the length of the branch section 34 along axis W, and more specifically, it is not a multiple or divisor of the length of the branch section 34.

[0121] The lateral duct 41 is actually advantageous because it acts as a resonator that enhances certain frequencies of sound pressure waves as a function of length along axis H. More precisely, a portion of the sound pressure waves exiting the lateral opening 40 in the crew compartment 5 has a frequency spectrum with increased intensity with respect to sound pressure waves entering through the inlet 23 at certain frequencies that are related (directly, inversely proportional) to the length of the lateral duct 41 along axis H.

[0122] Furthermore, the lateral duct 41 is advantageous because it allows a portion of the sound pressure wave to enter the occupant compartment 5 substantially in the center through the through-opening 36 and laterally through the lateral opening 40, thereby providing binaural perception of sound in the occupant compartment 5.

[0123] The lateral duct 41 may be considered to form part of the sound transmission duct 22.

[0124] The lateral duct 41 may be independent of the configuration of the branch section 34, and therefore may be applied to the solution in Figure 13 using innovative methods.

[0125] Preferably, the automobile 1 or the sound transmission duct 22 includes a divider or divider wall 47 that divides the diverging portion 35 and the connecting portion 42 laterally (according to axis Y). In other words, the divider 47 directly separates the diverging portion 35 and the connecting portion 42. That is, the divider 47 has a surface 47a that partially defines the diverging portion 35 and an opposite surface 47b that partially defines the connecting portion 42.

[0126] In the illustrated embodiment, specifically in Figure 5, the dividing partition 47 creates a narrowing or constriction of the area in the branching portion 34 at the beginning of the diverging portion 35 or just upstream of it.

[0127] Similarly, though unrelated, the dividing partition 47 is associated with the fact that at the connection node, that is, in the region where the connecting portion 42 connects to the branching portion 34, the cross-section or orthogonal area with respect to axis H is reduced with respect to the cross-section of the branching portion 34 with respect to axis W.

[0128] More specifically, the automobile 1 or the sound transmission duct 22 has an expansion box 50 for each branch 34. The diverging portion 35 of the branch 34 and the connecting portion 42 connected to the same branch 34 are the respective internal volumes of the expansion box 50, and therefore the expansion box 50 has an outlet at one end of the through-opening 36, an inlet communicating with the rest of the branch 34 excluding the diverging portion 35, and another outlet communicating with the rest of the lateral duct 41 excluding the connecting portion 42.

[0129] The expansion box 50 includes one of the dividing partitions 47, which are arranged inside or within the expansion box 50 to divide the internal volume of the expansion box 50.

[0130] Based on the foregoing, the advantages of the automobile 1 according to the present invention are clear.

[0131] The configuration of the branching section 34 and its connection to the distribution section 32 is designed to prevent sound intensity loss in the transmission of sound pressure waves due to free expansion during passage from the distribution section 32 to the branching section 34.

[0132] This is evident in Figure 11, which shows the frequency spectrum (frequency-intensity diagram) experimentally measured in the crew compartment 5, for example using a microphone, downstream of the sound transmission duct 22, starting from an upstream sound emitted with the same characteristics, according to the present invention and the previous solution depicted in Figure 13.

[0133] In Figure 11, the horizontal axis (frequency axis) of the graph represents the frequency value in Hertz (Hz), while the vertical axis (sound intensity or amplitude A-axis) of the graph in Figure 11 represents the sound intensity or amplitude value in decibels (dB) associated with the corresponding frequency.

[0134] Figure 11 clearly shows how the thick lines representing the sound downstream of the sound transmission duct 22 according to the present invention have a higher intensity than the thin lines associated with the solution depicted in Figure 13, for substantially all frequencies, specifically at multiples of the fundamental frequency or carrier frequency of the emitted sound. The dashed lines in Figure 11 represent the frequency spectrum measured after the firewall 15 facing the engine compartment 6. The thick lines are particularly close to the dashed lines, which demonstrates the effectiveness of the present invention.

[0135] The lateral duct 41 further enables certain frequency surges that would not be perceptible in the occupant compartment 5 in the absence of the lateral duct 41, due to intensity losses clearly associated with such frequencies. For example, Figure 11 shows the original frequency surge symbolically identified by the value F4, which was not possible using the previous solution in Figure 13.

[0136] Finally, it is clear that modifications and changes that do not deviate from the scope of protection defined by the claims may be made to the automobile 1 according to the present invention.

[0137] Specifically, the number and shape of each component described and illustrated may vary, particularly with reference to the branch 34, the lateral opening 40, the through opening 36, and so on.

[0138] The firewall 15 is clearly positioned at the rear of the vehicle 1, since the vehicle 1 is clearly a rear-wheel-drive vehicle in this case. However, this is not limiting, as the present invention can also be applied to a front-wheel-drive vehicle, and therefore the firewall is positioned at the front of the vehicle.

[0139] Furthermore, various embodiments or examples described herein can be estimated, without limitation, and combined individually with each other, with particular reference to the various characteristics described individually in various paragraphs of this specification.

[0140] Herein, several possible embodiments of this description may be considered, either independently of or in combination with those described above.

[0141] According to a possible first embodiment, the automobile 1 is - Engine 8 and, - Engine compartment 6 housing engine 8, - Crew compartment 5 and, - Firewall 15 and, - An interior trim panel 16 having a thickness, a first surface 17 facing the crew compartment 5, and a second surface 18 opposite to the first surface 17 in the direction of the thickness and facing the firewall 15, thereby at least partially defining the compartment 21 between itself and the firewall 15, the firewall 15 separating the compartment 21 from the engine compartment 6, the interior trim panel 16 and - A sound transmission duct 22 having an inlet 23 in the engine compartment 6 to receive one or more sound pressure waves, and extending along a first axis K to at least one distribution portion 32 until it divides at a dividing node into at least two unconnected branch portions 34 that extend at least partially in the compartment 21 along each branch axis W until it discharges at one or more first through-openings 36 of the trim panel 16 with each diverging portion 35, wherein each diverging portion 35 is configured to gradually diverge toward the first through-opening 36 along the associated branch axis W, and the first through-opening 36 communicates with the occupant compartment 5, Equipped with, The branch section 34 is connected to the distribution section 32 at the division node and has connecting ends 38 that start from the division node and have respective branch cross-sections with respect to the associated branch axis W, wherein the branch cross-sections define a branch section area that is smaller than, or at most equal to, the terminal area of ​​the cross-section of the distribution section 32 with respect to the first axis K at the division node, and / or The branch portion 34 extends along the branch axis W from the dividing node to the beginning of the diverging portion 35, or to the beginning of the branch portion of the branch portion 34, respectively, with a divergent configuration toward the first through-opening 36, which follows the associated branch axis W, with a constant area of ​​the cross-section of the branch portion 34 with respect to the branch axis W, or with a converging configuration toward the beginning of the diverging portion 35, which follows the associated branch axis W. It is characterized by the following.

[0142] In a possible second preferred embodiment following the first embodiment, the branch area and the terminal area belong to the same cutting plane perpendicular to the first axis K.

[0143] In a third preferred embodiment that may follow the first or second embodiment, the branching axis W has chamfered arcs W' at the connecting end 38, the chamfered arcs W' split from each other and begin tangentially from the first axis K at the splitting nodes.

[0144] In a fourth preferred embodiment that may follow any of the embodiments of the first to third embodiments, the distribution portion 35 extends partially in the engine compartment 6, starting from the inlet 23, and extends partially in the compartment 21, passing through the firewall 15, thereby positioning the distribution node in the compartment 21.

[0145] In a possible fifth preferred embodiment following the fourth embodiment, the first axis K extends substantially longitudinally in section 21 along the roll axis X of the vehicle, and the branch axis W has sections that extend laterally relative to the first axis K.

[0146] In a sixth preferred embodiment that may follow any of the embodiments of the first to fifth embodiments, the branching axis W points upward in the first opening 36.

[0147] In a seventh preferred embodiment that may follow any of the embodiments of the first to sixth embodiments, at least one of the branching axes W is a curve and is provided with one or more inflection points F, preferably at least two or at least three inflection points F.

[0148] In an eighth preferred embodiment, which may follow any of the embodiments of the first to seventh embodiments, the interior trim panel 16 has two lateral ends 16a, 16b opposite to each other according to the pitch axis Y of the vehicle, and the lateral ends 16a, 16b are provided with lateral through-openings 40 communicating with the respective lateral end regions of the occupant compartment 5, the first opening 36 is positioned between the lateral openings 40 according to the pitch axis Y, and the vehicle 1 further comprises a lateral duct 41 having connecting portions 42 that connect to branch portions 34, each with a configuration that is parallel to the diverging portion 35 and extends along the respective second axis H from the connecting portion 42 to discharge at the respective lateral openings 40, and each further diverging portion 43 has a configuration that progressively diverges toward the lateral openings 40 according to the associated second axis H.

[0149] In a possible ninth preferred embodiment according to the eighth embodiment, the automobile 1 further comprises, from a further connecting portion 42 of the lateral duct 41, each dividing partition 47 that laterally divides the diverging portion 35 of the branch 34.

[0150] In a possible tenth preferred embodiment according to the ninth embodiment, each of the diverging portions 35 and each of the further connecting portions 42 of the lateral duct 41 are defined by the internal volume of each expansion box 50 having a first outlet in one of the first openings 36, a second outlet in the remaining part of the lateral duct 41 that is related to the further connecting portions 42, and an inlet that communicates with the remaining part of the branch 34 that is related to the diverging portions 35, the expansion box 50 further comprises internally one of a dividing partition 47 arranged to divide the internal volumes from each other.

[0151] In an eleventh preferred embodiment that may follow any of the embodiments of the first to tenth embodiments, the first opening 36 is positioned in the rear window 19 of the vehicle or faces the roof 20 and / or rear window 19 of the vehicle 1. [Explanation of Symbols]

[0152] 1. Automobile 2 Main unit 3 Chassis 4 car bodies 5. Crew compartment 6. Engine compartment 7 wheels 8 engines 9. Intake manifold 10 Exhaust manifold 11 Intake piping 12 Exhaust piping 13 Turbocharger 15 Firewall 16 Interior trim panels 17. The first side 18. Second side 19 Rear window 20 Roof 21 plots 22 Sound transmission duct 23 Entrance 24 Sound transmission piping 25 Sound transmission piping 26 ducts 27 Resonance Devices 28 ducts 29 Duct 30 Resonance Devices 31 Duct 32 Distribution part 34 Non-connected branch section 35 Divergent portion, distribution portion 36 First through-opening 37 Top 38 Connection terminal, connection part 40 Second through-opening 41. Side duct 42 Connection part 43 Divergent portion 44 part 45 Divergent portion 47. Dividing partitions, dividing walls 47a, 47b side C, V duct F inflection point H Second axis K First axis M Microphone W branching axis W' Chamfered arc X-roll axis Y pitch axis Z-Yaw Axis

Claims

1. Automobile (1), Engine (8) and The engine compartment (6) housing the engine (8), Crew compartment (5) and, Firewall (15) and An interior trim panel (16) having a thickness, a first surface (17) facing the occupant compartment (5), and a second surface (18) opposite to the first surface (17) in the direction of the thickness and facing the firewall (15), thereby at least partially defining a compartment (21) between itself and the firewall (15), wherein the firewall (15) separates the compartment (21) from the engine compartment (6), and the interior trim panel (16) A sound transmission duct (22) having an inlet (23) in the engine compartment (6) to receive one or more sound pressure waves, and extending along a first axis (K) to at least one distribution portion (32) until it divides at a dividing node into at least two unconnected branch portions (34) that extend at least partially in the compartment (21) along each branch axis (W) until it discharges at one or more first through-openings (36) of the trim panel (16) at each diverging portion (35), wherein each of the diverging portions (35) is configured to gradually diverge toward the first through-opening (36) along the associated branch axis (W), and the first through-opening (36) communicates with the occupant compartment (5), Equipped with, The automobile (1) is further characterized by comprising a lateral duct (41) having connecting portions (42) that connect to the branch portions (34), with each connecting portion (42) extending along the respective second axis (H) from the connecting portion (42) to the second through-opening (40) of the trim panel (16), which communicates with the occupant compartment (5), parallel to the diverging portion (35).

2. The automobile according to claim 1, wherein the lateral duct (41) discharges at the second through-opening (40), and each further diverging portion (43) is configured to diverge progressively toward the second through-opening (40) according to the associated second axis (H).

3. The automobile according to claim 1 or 2, wherein the first through-opening (36) is perfectly positioned between the second through-openings (40) according to the pitch axis (Y) of the automobile (1).

4. The automobile according to any one of claims 1 to 3, wherein the interior trim panel (16) has two lateral ends (16a, 16b) opposite to each other according to the pitch axis (Y) of the automobile (1), and the lateral ends (16a, 16b) are defined by the second through-opening (40), each of which is provided with a lateral through-opening (40) that communicates with the respective lateral end regions of the occupant compartment (5).

5. The automobile according to claim 4, wherein the lateral through-opening (40) is at least partially defined by the lateral extreme edges of the lateral ends (16a, 16b) in accordance with the pitch axis (Y).

6. The automobile according to any one of claims 1 to 5, wherein the length of the lateral duct (41) along the second axis (H) is different from the length of the branch section (34) along the branch axis (W).

7. The automobile according to any one of claims 1 to 6, wherein the length of the lateral duct (41) along the second axis (H) is less than the length of the branch section (34) along the branch axis (W).

8. The automobile according to any one of claims 1 to 7, wherein the length of the lateral duct (41) along the second axis (H) is not a multiple or divisor of the length of the branch section (34) along the branch axis (W).

9. Automobile (1), Engine (8) and The engine compartment (6) housing the engine (8), Crew compartment (5) and, Firewall (15) and An interior trim panel (16) having a thickness, a first surface (17) facing the occupant compartment (5), and a second surface (18) opposite to the first surface (17) in the direction of the thickness and facing the firewall (15), thereby at least partially defining a compartment (21) between itself and the firewall (15), wherein the firewall (15) separates the compartment (21) from the engine compartment (6), and the interior trim panel (16) A sound transmission duct (22) having an inlet (23) in the engine compartment (6) to receive one or more sound pressure waves, and extending along a first axis (K) to at least one distribution portion (32) until it divides at a dividing node into at least two unconnected branch portions (34) that extend at least partially in the compartment (21) along each branch axis (W) until it discharges at one or more first through-openings (36) of the trim panel (16) at each diverging portion (35), wherein each of the diverging portions (35) is configured to gradually diverge toward the first through-opening (36) along the associated branch axis (W), and the first through-opening (36) communicates with the occupant compartment (5), Equipped with, The branch section (34) is connected to the distribution section (32) at the division node and has a connecting end (38) that starts from the division node and has a branch cross section with respect to the associated branch axis (W), wherein the branch cross section has a branch area that is smaller than, or at most equal to, the terminal area of ​​the cross section of the distribution section (32) with respect to the first axis (K) at the division node, and / or The branch portion (34) extends along the branch axis (W) from the dividing node to the beginning of the diverging portion (35) or to the beginning of the branch portion of the branch portion (34), respectively, with a diverging configuration toward the first through-opening (36) with respect to the branch axis (W), or with a converging configuration toward the beginning of the diverging portion (35) with respect to the branch axis (W), respectively. A car (1) characterized by the following.

10. The automobile according to claim 9, wherein the branch area and the terminal area belong to the same cutting plane perpendicular to the first axis (K).

11. The automobile according to claim 9 or 10, wherein the branch shaft (W) has a chamfered arc (W') at the connecting end (38), the chamfered arcs (W') divide from each other, and at the dividing node, the division begins tangentially from the first shaft (K).

12. The automobile according to any one of claims 9 to 11, wherein the distribution portion (35) extends in part in the engine compartment (6) and begins at the inlet (23), and extends in part in the compartment (21) and passes through the firewall (15), thereby positioning the dividing node in the compartment (21).

13. The automobile according to claim 12, wherein the first axis (K) extends substantially longitudinally in the section (21) according to the roll axis (X) of the automobile, and the branch axis (W) has sections that extend laterally with respect to the first axis (K).

14. The automobile according to any one of claims 9 to 13, wherein the branch shaft (W) points upward in the first opening (36).

15. The automobile according to any one of claims 9 to 14, wherein at least one of the branching shafts (W) is a curve and is provided with one or more inflection points (F), preferably at least two or at least three inflection points (F).

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