Vehicle front structure

Abstract

To provide a vehicle front part structure capable of suppressing intrusion of noise into a cabin.SOLUTION: The vehicle front portion structure 10 includes a dash lower 22 that is integrally formed with a skeleton portion of a vehicle front portion by casting and has a rib 26 on a vehicle cabin inner side, a soundproof member 60 that is disposed along the rib 26, a dash silencer 40 that is disposed adjacent to a vehicle upper side of the soundproof member 60, a floor silencer 50 that is disposed adjacent to a vehicle rear side of the soundproof member 60, and a pad member 70 that is disposed adjacent to the vehicle cabin inner side of the soundproof member 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle front structure. [Background technology]

[0002] Patent Document 1 discloses a structure in which a pad member is provided at the boundary between the vehicle interior floor and the dash section, thereby forming a flat toe board surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-104242 Summary of the Invention [Problem to be solved by the invention]

[0004] When a vehicle's front module is integrally formed by casting, the dash lower is sometimes integrally formed with the front frame of the vehicle and has reinforcing ribs. In this case, even if the dash silencer that covers the dash panel is extended downward, it cannot ensure conformance to the ribs, and noise generated by the tires and other components while driving may enter the passenger compartment.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a vehicle front structure that can suppress noise from entering the vehicle interior. [Means for solving the problem]

[0006] The vehicle front structure of the first aspect of the present invention is characterized by comprising a dash lower that is integrally molded by casting into the skeleton of the front of the vehicle and has a rib on the interior side of the vehicle, a soundproofing member arranged along the rib, a dash silencer arranged adjacent to the upper side of the soundproofing member on the vehicle, a floor silencer arranged adjacent to the rear side of the soundproofing member on the vehicle, and a pad member arranged adjacent to the interior side of the soundproofing member.

[0007] In the first embodiment of the vehicle front structure, a dash lower is integrally molded with a vehicle front frame by casting. The dash lower has a rib formed on the interior side of the vehicle, and this rib reinforces the integrally molded frame and dash lower.

[0008] A padding member is placed on the interior side of the dash lower to form a toe board on which passengers place their feet. However, when reinforcing ribs are formed on the dash lower, the padding member may not be able to conform to the ribs properly, resulting in unnecessary gaps between the padding members. These gaps allow noise generated outside the vehicle cabin to easily penetrate into the interior.

[0009] In contrast, in the vehicle front structure of the first aspect, a soundproofing member is arranged along the rib on the interior side of the dash lower. Adjacent to this soundproofing member, a dash silencer is arranged on the upper side of the vehicle, a floor silencer is arranged on the rear side of the vehicle, and a pad member is arranged on the interior side of the vehicle. Therefore, the soundproofing member effectively prevents noise from entering the vehicle cabin through the rib. This prevents noise from entering the vehicle cabin.

[0010] A vehicle front structure according to a second aspect of the present invention is the same as the first aspect, in which the soundproofing members are disposed on both sides of the dash lower in the vehicle width direction.

[0011] In the vehicle front structure of the second aspect, soundproofing members are disposed on both sides of the dash lower section in the vehicle width direction, which are located near the wheel housings, thereby effectively suppressing the intrusion of noise generated by tires during driving.

[0012] A third aspect of the vehicle front structure of the present invention is a configuration described in the first or second aspect, in which, in the portion where the soundproofing member and the pad member are adjacent, one of the soundproofing member and the pad member has a convex portion and the other has a concave portion, and the convex portion fits into the concave portion.

[0013] In the vehicle front structure of the third aspect, where the soundproofing member and the padding member are adjacent to each other, a convex portion on one side fits into a concave portion on the other side, which prevents the padding member from shifting position relative to the soundproofing member and stabilizes the toe board surface.

[0014] A fourth aspect of the vehicle front structure of the present invention is a configuration described in the first or second aspect, in which the soundproofing member and the dash silencer are arranged adjacent to each other with portions overlapping in the fore-and-aft direction of the vehicle.

[0015] In the vehicle front structure of the fourth aspect, the soundproofing member and the dash silencer are arranged adjacent to each other with a portion overlapping in the fore-and-aft direction of the vehicle. Therefore, when noise penetrates through a gap between the members, the path length of the penetration can be increased. Therefore, even if a gap occurs between the members, the noise can be attenuated before it penetrates into the passenger compartment. Furthermore, even if variations in the assembly position due to dimensional tolerances or the like occur when assembling the soundproofing member and the dash silencer, the overlap in the fore-and-aft direction of the vehicle can absorb the variations in position. This results in a robust soundproofing effect.

[0016] A fifth aspect of the vehicle front structure of the present invention is a configuration described in the first or second aspect, in which the soundproofing member and the floor silencer are arranged adjacent to each other with portions overlapping in the vertical direction of the vehicle.

[0017] In the vehicle front structure of the fifth aspect, the soundproofing member and the floor silencer are arranged adjacent to each other with a portion of the member overlapping in the vertical direction of the vehicle. Therefore, when noise penetrates through a gap between the members, the path length of the noise can be increased. Therefore, even if a gap occurs between the members, the noise can be attenuated before it penetrates into the passenger compartment. Furthermore, even if variations in the assembly position due to dimensional tolerances or the like occur when assembling the soundproofing member and the floor silencer, the overlap in the longitudinal direction of the vehicle can absorb the variations in position. This results in a robust soundproofing effect. [Effects of the Invention]

[0018] As described above, the vehicle front structure according to the present invention can suppress noise from entering the vehicle interior. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view schematically showing a vehicle to which a vehicle front structure according to an embodiment of the present invention is applied. [Figure 2] 1 is a partially exploded perspective view showing a soundproofing module arranged in the vehicle front structure according to the present embodiment. FIG. [Figure 3] 3 is a cross-sectional view of the front part of the vehicle taken along line 3-3 in FIG. 2. FIG. [Figure 4] 4 is a cross-sectional view of the front part of the vehicle taken along line 4-4 in FIG. 2. [Figure 5] 5 is a cross-sectional view of the soundproofing member and the dash panel lower taken along line 5-5 in FIG. 3. FIG. [Figure 6] FIG. 2 is a cross-sectional view schematically showing a first modified example of the soundproofing member according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] A vehicle front structure 10 according to this embodiment will be described below with reference to Figures 1 to 6. Note that the arrow FR shown as appropriate in each figure indicates the front side of the vehicle, the arrow UP indicates the upper side of the vehicle, and the arrow LH indicates the left side of the vehicle. Furthermore, when the front-rear, up-down, and left-right directions are used in the following description unless otherwise specified, they refer to front-rear in the front-rear direction of the vehicle, up-down in the up-down direction of the vehicle, and left-right when facing the direction of travel.

[0021] Unless otherwise specified in the specification, each element is not limited to one and may be present in plural. Furthermore, in the drawings, substantially identical elements are denoted by the same reference numerals, and redundant explanations in the specification will be omitted.

[0022] (Front view of the vehicle) 1 is a cross-sectional view schematically showing the front of a vehicle 12 to which a vehicle front structure 10 according to this embodiment is applied. The vehicle 12 in this embodiment is, for example, an electric vehicle that runs using the driving force of an electric motor (not shown). Examples of electric vehicles include HEVs (Hybrid Electric Vehicles), PHEVs (Plug-in Hybrid Electric Vehicles), BEVs (Battery Electric Vehicles), and FCEVs (Fuel Cell Electric Vehicles).

[0023] As shown in Fig. 1, a front cross member 14 is disposed as a framework at the front of a vehicle 12. The front cross member 14 extends longitudinally in the vehicle width direction, and both ends in the vehicle width direction are connected to the lower end portions of a pair of left and right pillars 16. The pillars 16 are disposed on both sides in the vehicle width direction as frameworks of the vehicle 12. The left and right pillars 16 extend longitudinally in approximately the vehicle up-down direction, and their upper ends are connected to the front end portions of roof reinforcement (not shown).

[0024] A pair of side members 15, which form the framework of the vehicle 12, are disposed on the vehicle front side of the front cross member 14. The pair of side members 15 extend longitudinally in the vehicle longitudinal direction, and are disposed on both sides in the vehicle width direction. The rear portions of the pair of side members 15 are connected to both ends of the front cross member 14 in the vehicle width direction. Wheel houses (not shown) that house the front wheels (tires) of the vehicle 12 are integrally formed on the rear portions of the pair of side members 15.

[0025] Furthermore, a pair of rockers (not shown) that form the framework of the vehicle 12 are arranged on the vehicle rear side of the front cross member 14. The pair of rockers extend longitudinally in the approximately vehicle fore-and-aft direction and are arranged on both sides in the vehicle width direction. The front portions of the pair of rockers are connected to both ends of the front cross member 14 in the vehicle width direction. In addition, the rear portions of the pair of rockers are connected to both ends of the rear cross member (not shown) in the vehicle width direction.

[0026] In the vehicle 12, a battery case (not shown) that houses multiple battery stacks or multiple battery stacks are directly supported on a substantially rectangular frame formed by the front cross member 14, the rear cross member, and a pair of rockers. The battery stack is a module formed by stacking multiple battery cells.

[0027] Additionally, a plate-shaped floor panel 20 that forms the floor of the passenger compartment 18 is supported on a substantially rectangular frame formed by the front cross member 14, rear cross member, and pair of rockers. The floor panel 20 is disposed above the battery case or battery stack, and its outer periphery is connected to the frame. Note that if the battery case is attached to the frame formed by the front cross member 14, rear cross member, and pair of rockers, the floor panel 20 is not essential and may be omitted. In this case, the upper surface of the battery case may form the floor of the passenger compartment.

[0028] The front cross member 14, the pair of left and right pillars 16, and the pair of left and right side members 15 are formed, for example, from metal materials such as aluminum alloys and magnesium alloys. The front cross member 14, the pair of left and right pillars 16, and the pair of left and right side members 15 are integrally formed by casting. Therefore, these members have an open cross section that is open in at least one of the vehicle longitudinal direction, the vehicle vertical direction, and the vehicle width direction, corresponding to the drawing direction of the casting mold. In this embodiment, the cut surface of the front cross member 14 in the vehicle longitudinal direction has an open cross section that is open to the rear and downward sides of the vehicle.

[0029] It is not essential that the front cross member 14, the pair of left and right pillars 16, and the pair of left and right side members 15 are integrally formed, and some or all of the members may be formed separately. Furthermore, when some or all of the members are formed separately, the cross-sectional shape of each member may be a closed cross section.

[0030] (Dash lower) A dash lower 22 is disposed above the vehicle from the front cross member 14. The dash lower 22 supports a dash panel 24 that separates the passenger compartment 18 at the front of the vehicle from a power unit room (not shown). The power unit room is formed inside the pair of left and right side members 15 and houses a motor and other components that provide driving force during driving.

[0031] The dash lower 22 is a substantially rectangular plate-like member formed of a metal material such as an aluminum alloy or a magnesium alloy. The dash lower 22 is disposed inside a substantially rectangular frame formed by the front cross member 14, a pair of left and right pillars 16, and a cowl panel (not shown) that connects the pair of left and right pillars 16 at their intermediate portions in the vehicle vertical direction. The dash lower 22 has, for example, a substantially U-shaped opening 23 that opens toward the upper side of the vehicle when viewed in the vehicle front-rear direction, and a dash panel 24 is attached to the opening 23. A plurality of on-board devices (not shown) and harnesses extending from each on-board device are attached to the dash panel 24.

[0032] Here, in this embodiment, the dash lower 22 is molded integrally with the front cross member 14 and the pair of left and right pillars 16 by casting. Therefore, the dash lower 22 is molded integrally with the upper surface 14A of the front cross member 14 and stands upright above the vehicle from the upper surface 14A. Furthermore, the ends of the dash lower 22 in the vehicle width direction are molded integrally with the inner side surfaces of the pair of left and right pillars 16 in the vehicle width direction.

[0033] Here, multiple reinforcing ribs 26 are integrally molded on the lower part of the side surface 22A of the dash lower 22 facing the interior of the vehicle. Each rib 26 connects the side surface 22A of the dash lower 22 facing the interior of the vehicle to the upper surface 14A of the front cross member 14, and forms a generally triangular shape when viewed from the vehicle width direction. Therefore, the connection between the front cross member 14 and the dash lower 22 is reinforced by the ribs 26, and the cross-sectional area of ​​the front cross member 14 is effectively increased in the portion where the ribs 26 are located. This mutually increases the rigidity of the dash lower 22 and the front cross member 14.

[0034] In this embodiment, multiple ribs 26 are provided on both the right and left sides of the dash lower 22 in the vehicle width direction, thereby reinforcing both sides of the front cross member 14 in the vehicle width direction. Both sides of the front cross member 14 in the vehicle width direction are connected to the vehicle rear portions of the pair of left and right side members 15 and are located near wheel houses integrally molded with the side members 15. Therefore, by reinforcing both sides of the front cross member 14 and the dash lower 22 in the vehicle width direction with ribs 26, when vibrations of the front wheels (tires) during driving are transmitted to the front cross member 14 via the wheel houses and the pair of side members 15, the transmission of the vibrations to the dash lower 22 is suppressed. This also suppresses noise caused by vibrations of the front wheels (tires) during driving.

[0035] The above-described configuration of the dash lower 22 is merely an example and is not essential. For example, the dash lower 22 may be integrally molded with the front cross member 14, with the pillars 16 configured as separate pieces. Also, the placement of the reinforcing rib 26 is merely an example, and the rib 26 may be provided in the center of the dash lower 22 in the vehicle width direction.

[0036] (soundproof module) As shown in FIG. 1, a soundproofing module 30 is disposed on the interior side of the dash panel 24, dash lower 22, and floor panel 20 to block noise generated outside the vehicle compartment.

[0037] 2 is an exploded perspective view showing a part of the soundproofing module 30. As shown in FIG. 2, the soundproofing module 30 is configured to include a dash silencer 40, a floor silencer 50, a soundproofing member 60, and a pad member 70. The upper surface of the soundproofing module 30 is covered with a separate floor carpet 32 ​​(covering material) that forms the design surface of the floor of the vehicle interior 18. The floor carpet 32 ​​is made of, for example, a carpet covering or a rubber material. The floor carpet 32 ​​may be joined to the floor silencer 50 and configured integrally with the floor silencer 50, or may be configured separately and placed on top of the floor silencer 50 as in this embodiment.

[0038] (Dash silencer) The dash silencer 40 is a sheet-like member that has sound-insulating and sound-absorbing properties, and is mainly attached to the entire side surface of the dash panel 24 facing the interior of the vehicle (covering the side surface of the dash panel 24 facing the interior of the vehicle).

[0039] More specifically, dash silencer 40 has, as an example, a substantially T-shape when viewed from the vehicle longitudinal direction, and extends in the vehicle width direction and the vehicle vertical direction. This dash silencer 40 is composed of, as an example, a substantially rectangular base portion 42 that forms a portion on the upper side of the vehicle, and an extension portion 44 that extends downward from the center of base portion 42 in the vehicle width direction.

[0040] Base portion 42 is disposed across dash panel 24 and the upper portion of dash lower 22, covering the entire cabin-side side surface of dash panel 24 and the upper portion of cabin-side side surface 22A of dash lower 22. The lower ends of both sides of base portion 42 in the vehicle width direction are adjacent to the upper side of soundproofing member 60, which will be described later.

[0041] The extension 44 covers the center in the vehicle width direction of the vehicle lower portion of the dash lower 22. The lower end of the extension 44 is adjacent to the front end of a floor silencer 50, which will be described later. In addition, both ends of the extension 44 in the vehicle width direction are adjacent to the inner sides in the vehicle width direction of soundproofing members 60, which will be described later.

[0042] (Floor silencer) The floor silencer 50 is a sheet-like member with sound-insulating and sound-absorbing properties, and is primarily attached to the entire side (top) of the floor panel 20 facing the interior of the vehicle (covering the side of the floor panel 20 facing the interior of the vehicle).

[0043] More specifically, floor silencer 50 has a generally rectangular shape when viewed from the vertical direction of the vehicle. As an example, floor silencer 50 is composed of a generally rectangular base portion 52 that covers the entire side surface of floor panel 20 facing the interior of the vehicle, and an extension portion 54 that extends from the center of base portion 52 in the vehicle width direction toward the front and upper sides of the vehicle at the front end side of base portion 52.

[0044] The front ends of both sides of the base portion 52 in the vehicle width direction are adjacent to the vehicle rear side of a soundproofing member 60, which will be described later. In addition, both ends of the extension portion 54 in the vehicle width direction are adjacent to the vehicle width direction inner sides of the soundproofing member 60. In addition, the upper end (front end) of the extension portion 54 is adjacent to the vehicle lower side of the base portion 42 of the dash silencer 40.

[0045] (soundproofing materials) The soundproofing members 60 are tile-shaped members that have sound-insulating and sound-absorbing properties, and are primarily arranged so as to cover the plurality of ribs 26 provided on the dash lower 22 from the inside of the vehicle compartment (covering the plurality of ribs 26). Therefore, in this embodiment, a pair of left and right soundproofing members 60 are arranged on both sides of the dash lower 22 in the vehicle width direction.

[0046] More specifically, the soundproofing member 60 has a generally rectangular shape when viewed from the front-rear direction of the vehicle, and extends in the vehicle width direction and the vehicle up-down direction. The soundproofing member 60 has a plurality of protrusions 62 formed on a side surface 60A facing the interior of the vehicle. The plurality of protrusions 62 protrude into the interior of the vehicle and are configured to fit into a plurality of recesses 72 formed on the opposing surface of a pad member 70, which will be described later. The number of protrusions 62 can be changed as appropriate and may be, for example, one.

[0047] As an example, each of the protrusions 62 has a substantially triangular shape and tapers toward the upper side of the vehicle. By tapering each of the protrusions 62, the tapered end can be inserted into the recess 72, improving workability and positioning accuracy during assembly.

[0048] Furthermore, the side surface 60B of the soundproofing member 60 facing the dash lower section 22 has a three-dimensional shape that conforms to the rib 26. In other words, the side surface 60B of the soundproofing member 60 facing the dash lower section 22 is disposed along the rib 26. More specifically, as will be described later, the bag body 64 that constitutes the intermediate layer 602 of the soundproofing member 60 deforms to follow the shape of the rib 26. As a result, the side surface 60B (bag body 64) facing the dash lower section 22 is disposed along the rib 26.

[0049] In this embodiment, the dash silencer 40 is disposed adjacent to the vehicle upper side (upper end) of the soundproofing member 60. Furthermore, the floor silencer 50 is disposed adjacent to the vehicle rear side (lower end) of the soundproofing member 60. Furthermore, the dash silencer 40 and a portion of the floor silencer 50 are disposed adjacent to the soundproofing member 60 on the inner side in the vehicle width direction.

[0050] (Pad material) The pad members 70 are tile-shaped members with shock-absorbing properties, and are made of, for example, a foamed resin molding obtained by mixing a foaming agent with a resin material such as polypropylene resin or polystyrene resin and then hot-molding the mixture. The pad members 70 are mainly disposed adjacent to the soundproofing members 60 on the interior side of the vehicle. In this embodiment, a pair of left and right pad members 70 are disposed so as to cover each of the pair of soundproofing members 60 from the interior side of the vehicle.

[0051] The side surface of the pad member 70 facing the interior of the vehicle compartment is a flat surface that forms a toe board surface on which the feet of an occupant seated in the seat S that constitutes the driver's seat or passenger seat of the vehicle 12 are placed. In addition, the thickness of each portion of the pad member 70 is adjusted so as to form a surface that is continuous with the dash silencer 40 and floor silencer 50 that are adjacent to each other.

[0052] Furthermore, the pad member 70 has a side surface facing the soundproofing member 60 (the side surface facing the outside of the vehicle cabin) formed with a plurality of recesses 72 that correspond to the plurality of protrusions 62 provided on the soundproofing member 60. The shape of the recesses 72 is a substantially triangular shape that corresponds to the shape of the protrusions 62 of the soundproofing member 60. The plurality of protrusions 62 provided on the soundproofing member 60 fit into the plurality of recesses 72 of the pad member 70, thereby suppressing misalignment of the pad member 70 with respect to the soundproofing member 60.

[0053] [Soundproof module transmission loss] Next, we will explain the transmission loss (TL) of the soundproofing module 30. The transmission loss is a value measured using the difference in volume (difference in sound pressure level) between the sound incident on a material layer such as a wall and the sound that passes through the material layer and enters the room. Therefore, in terms of improving the soundproofing of the vehicle interior 18, the larger the transmission loss of the soundproofing module 30, the better.

[0054] It is known that the transmission loss value increases with increasing mass per unit area and increasing frequency in the case of a homogeneous single-layer material. Therefore, in the soundproofing module 30 of this embodiment, if the dash silencer 40, floor silencer 50, and soundproofing member 60 are made of a single-layer material, it is preferable to increase the mass of each member in order to ensure transmission loss. However, in this case, prioritizing ensuring transmission loss poses a problem of increasing the weight of the soundproofing module.

[0055] On the other hand, when the material has a multi-layer structure that includes air layers, the transmission loss changes due to the "spring-mass model" that is made up of a material layer with a large mass (mass layer) and an air layer with a small mass. In other words, the air layer acts as a spring, causing resonance at a specific frequency, and the transmission loss increases above this frequency band.

[0056] Furthermore, when the vibration of a two-layered material is calculated using the surface vibration in the known spring-mass model, it is known that the resonant frequency [f0] is proportional to the square root of the ratio of the spring constant [k] of the inner middle layer (air layer) to the mass [m] of the surface layer (mass layer), as shown in the following equation (1).

[0057] (Formula 1) JPEG2026013743000002.jpg1521

[0058] Therefore, in the case of a two-layer structure material, in terms of improving the soundproofing of the vehicle interior 18, it is preferable that the mass of the surface layer (mass layer) is as large as possible, and the spring constant of the intermediate layer (air layer) is as small as possible.

[0059] Due to the characteristics of the multilayer structure material described above, in the soundproof module 30 of this embodiment, the dash silencer 40 and the soundproof member 60 are made of a multilayer structure (two-layer structure in this embodiment) material in order to reduce weight and improve soundproofing. Note that the floor silencer 50 of this embodiment, together with the floor carpet 32, constitutes a "spring-mass model" of a multilayer structure (two-layer structure).

[0060] 3, the dash silencer 40 and the floor silencer 50 have surface layers 401, 501 made of, for example, a rubber material, and inner intermediate layers 402, 502 made of a fiber material or a urethane material. The surface layer 501 of the floor silencer 50 is made of the floor carpet 32. There are no particular restrictions on the material of the intermediate layers 402, 502, but if they are made of a fiber material, air is trapped between the fibers, resulting in a layer that has springiness like an air layer in relation to the surface layers 401, 501. Examples of fiber materials include felt and nonwoven fabric, and in this embodiment, felt is used.

[0061] As shown in FIGS. 3 to 5, the soundproofing member 60 has a surface layer 601 made of a rubber material, and a convex portion 62 is integrally formed on a side surface 60A facing the interior of the vehicle. The intermediate layer 602 of the soundproofing member 60 is formed by housing granular cushioning material 66 inside a bag 64 formed of a thin-film material (e.g., polyvinyl chloride). The type of cushioning material 66 is not particularly limited as long as it has a smaller mass per unit volume than the material of the surface layer 601. For example, the cushioning material 66 may be made of resin, wood, foam, or the like, or a mixture of granular cushioning materials made from a plurality of these materials. Alternatively, the intermediate layer 602 may be made by finely powdering waste material and forming it into granules. By containing air between the particles, the intermediate layer 602 becomes a layer with springiness similar to that of an air layer in relation to the surface layer 601.

[0062] In this embodiment, in order to improve the conformability of the dash lower 22 to the rib 26, the intermediate layer 602 of the soundproofing member 60 is softer than the intermediate layers 402, 502 of the dash silencer 40 and the floor silencer 50.

[0063] [On the robustness of soundproofing modules] Next, we will explain the robustness of the soundproofing module 30. In terms of blocking noise generated outside the vehicle cabin, it is preferable that no gaps occur between the components that make up the soundproofing module 30. However, when assembling multiple components, variations in the assembly positions occur due to dimensional tolerances of each component, and gaps may occur between the components.

[0064] Therefore, in the soundproofing module 30 of this embodiment, the adjacent soundproofing members 60 and the dash silencer 40 are configured to partially overlap in the area where the soundproofing member 60 and the floor silencer 50 are adjacent.

[0065] Specifically, in the portion where the soundproofing member 60 and the dash silencer 40 are adjacent to each other, the soundproofing member 60 and the dash silencer 40 are arranged adjacent to each other with a portion overlapping in the vehicle longitudinal direction. Here, the dash silencer 40 is adjacent to the soundproofing member 60 at the lower end portions of both sides in the vehicle width direction of the base portion 42 adjacent to the soundproofing member 60 and at the end portion in the vehicle width direction of the extension portion 44. These end portions of the dash silencer 40 are formed with step portions 46 facing the interior of the vehicle, and the plate thickness of the end portions is thin (see FIGS. 3 and 4 ). The adjacent end portions of the soundproofing member 60 are overlapped on the step portions 46 from the interior side (front side), so that the end portions overlap in the vehicle longitudinal direction. At this time, the middle layer 602 of the soundproofing member 60 deforms to follow the step portions 46 of the dash silencer 40 and is arranged along the step portions 46. As a result, in this embodiment, the side surface of the dash silencer 40 facing the interior of the vehicle and the side surface 60A (surface layers 401, 601) of the soundproofing member 60 facing the interior of the vehicle are continuous surfaces.

[0066] The same applies to the portion where the soundproofing member 60 and the floor silencer 50 are adjacent to each other. The soundproofing member 60 and the floor silencer 50 are arranged adjacent to each other with portions overlapping in the vehicle vertical direction. Here, the front ends of both sides in the vehicle width direction of the base portion 52 adjacent to the soundproofing member 60 and the end portions in the vehicle width direction of the extension portion 54 are adjacent to the soundproofing member 60. These ends of the floor silencer 50 are formed with step portions 56 facing the interior of the vehicle, and the plate thickness of the end portions is thin (see FIG. 3 ). The adjacent ends of the soundproofing member 60 are overlapped on these step portions 56 from the interior side (upper side) of the vehicle, so that the ends are overlapped in the vehicle vertical direction. At this time, the middle layer 602 of the soundproofing member 60 deforms to follow the step portions 56 of the floor silencer 50 and is arranged along the step portions 56. In this embodiment, when the surface of the soundproofing member 60 is covered with the pad member 70, the side surface (intermediate layer 502) of the floor silencer 50 facing the interior of the vehicle and the side surface of the pad member 70 facing the interior of the vehicle form a continuous surface.

[0067] As described above, because adjacent components are configured to partially overlap, the path length of noise that penetrates through gaps between components can be increased. That is, in this embodiment, the path length is along the stepped portions 46, 56, which is longer than the path length that would be achieved if noise passed through a gap between linear end faces without a stepped portion. Therefore, even if a gap occurs between components, the noise can be attenuated before it penetrates into the vehicle cabin. Furthermore, even if variations in the assembly positions of the components occur due to dimensional tolerances or the like, the overlapping portions between the end portions absorb the variations in position, making it less likely for gaps to occur. This results in a robust soundproofing effect.

[0068] (Action and effect) As described above, in the vehicle front structure 10 of this embodiment, the dash lower 22 is integrally molded with the framework of the vehicle front by casting. The dash lower 22 is formed with a rib 26 on the passenger compartment side, and this rib 26 reinforces the framework and the dash lower 22 that are integrally molded.

[0069] Typically, a padding member is provided on the interior side of the dash lower to form a toe board on which passengers place their feet. However, when the dash lower 22 is provided with reinforcing ribs 26, as in this embodiment, the padding member may not conform to the ribs 26 sufficiently, resulting in unnecessary gaps between the components. These gaps allow noise generated outside the vehicle cabin to easily enter the interior.

[0070] In contrast, in the vehicle front structure 10, a soundproofing member 60 is arranged along the rib 26 on the interior side of the dash lower 22. Adjacent to this soundproofing member 60, a dash silencer 40 is arranged on the upper side of the vehicle, a floor silencer 50 is arranged on the rear side of the vehicle, and a pad member 70 is arranged on the interior side of the vehicle. Therefore, the soundproofing member 60 effectively prevents noise from entering the vehicle interior via the rib 26. This prevents noise from entering the vehicle interior.

[0071] In this embodiment, soundproofing members 60 are disposed on both sides of the dash lower 22 in the vehicle width direction, which are located near the wheelhouses. This effectively prevents noise generated by the tires during driving from entering the vehicle.

[0072] Furthermore, in this embodiment, in the portion where the soundproofing member 60 and the pad member 70 are adjacent to each other, the convex portion 62 provided on the soundproofing member 60 fits into the concave portion 72 provided on the pad member 70. This makes it possible to prevent the pad member 70 from shifting in position relative to the soundproofing member 60, thereby stabilizing the toe board surface. Note that a configuration in which the convex portion provided on the pad member fits into the concave portion provided on the soundproofing member may also be used.

[0073] In this embodiment, the soundproofing member 60 and the dash silencer 40 are disposed adjacent to each other with a portion overlapping in the longitudinal direction of the vehicle, and the soundproofing member 60 and the floor silencer 50 are disposed adjacent to each other with a portion overlapping in the vertical direction of the vehicle. Therefore, when noise penetrates through a gap between the members, the path length at the time of penetration is increased, and the noise can be attenuated before it penetrates through the gap. Furthermore, even if variations in assembly position occur due to dimensional tolerances or the like, the positional variations can be absorbed by the overlapping portions between the members, resulting in excellent robustness in the soundproofing effect.

[0074] (First modified example of soundproofing member) In the above embodiment, the intermediate layer 602 of the soundproofing member 60 is configured by accommodating the granular cushioning material 66 in the bag body 64, but this is not limiting. A configuration of the soundproofing member 80 according to a first modified example shown in FIG. 6 may also be applied. Similar to the dash silencer 40 and the floor silencer 50, the soundproofing member 80 has a surface layer 801 facing the interior of the vehicle made of a rubber material or the like, and an inner intermediate layer 802 made of a fiber material such as felt or a urethane material. Even in this case, when the intermediate layer 802 is made of a fiber material or a urethane material, air is trapped between the fibers and between the foam cells, and thus the intermediate layer 802 has a springy property similar to an air layer in relation to the surface layer 801, thereby ensuring transmission loss.

[0075] Furthermore, in this first modified example, a plurality of notches 82 (cuts) are formed on the side surface of intermediate layer 802 of soundproofing member 60 that faces rib 26. This makes it possible to prevent the portion of soundproofing member 80 that follows rib 26 from being attracted to the surrounding fibers when attaching soundproofing member 80 to side surface 22A of dash lower 22, thereby improving the ability of soundproofing member 60 to follow rib 26.

[0076] (Second modified example of soundproofing member) Although not shown, when the soundproofing member is made of a two-layer material, the surface layer may be made of rubber and the middle layer may be made of a sponge material such as urethane or a granular sponge material. In this case, the soundproofing member can be formed by molding using a mold, so it can be easily formed into a shape that follows the ribs 26.

[0077] In the above embodiment, the dash silencer 40, the floor silencer 50, and the soundproofing member 60 are made of a multi-layered material, but this is not limitative and they may be made of a single-layered material. [Explanation of symbols]

[0078] 10 Vehicle front structure 12 vehicles 14 Front cross member (framework) 16 Pillar (framework) 22 Dash Lower 26 Ribs 40 Dash silencer 50 Floor silencer 60 Soundproofing materials 62 Convex part 70 Pad material 72 recess

Claims

1. a dash lower that is integrally formed with the vehicle front frame by casting and has a rib on the passenger compartment side; a soundproofing member disposed along the rib; a dash silencer disposed adjacent to the soundproofing member on an upper side of the vehicle; a floor silencer disposed adjacent to the soundproofing member on the vehicle rear side; a pad member disposed adjacent to the soundproofing member on the interior side of the vehicle.

2. The soundproofing members are disposed on both sides of the dash lower in the vehicle width direction. The vehicle front structure according to claim 1 .

3. In a portion where the soundproofing member and the pad member are adjacent to each other, one of the soundproofing member and the pad member has a convex portion and the other has a concave portion, and the convex portion is fitted into the concave portion. The vehicle front structure according to claim 1 or 2.

4. The soundproofing member and the dash silencer are disposed adjacent to each other with portions overlapping in the vehicle longitudinal direction. The vehicle front structure according to claim 1 or 2.

5. The soundproofing member and the floor silencer are arranged adjacent to each other with portions overlapping in the vehicle vertical direction. The vehicle front structure according to claim 1 or 2.

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