Vehicle body structure

Abstract

To provide a vehicle body structure of a vehicle which enables improvement of vibration damping performance while reducing the weight of a vehicle body.SOLUTION: A vehicle body structure includes: a lower plate 5 which is a first member having a vehicle body fixing part 5c fixed to a vehicle body 1 and a first flat surface 5d located at a position different from that of the vehicle body fixing part 5c; an upper plate 6 which is a second member having a second flat surface 6c facing the first flat surface 5d and is disposed in a state where the second flat surface 6c overlaps with the first flat surface 5d; and a vibration damping member 9 provided between the first flat surface 5d and the second flat surface 6c and having adhesiveness. In the lower plate 5, flexural rigidity or twisting rigidity is set so as to be lower than that of the upper plate 6.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] 2. Description of the Related Art In recent years, there has been an increasing demand for suppressing vibrations in a vehicle body in order to improve the ride comfort of the vehicle. For this reason, various vibration suppression structures have been proposed for areas around the passenger compartment of the vehicle body.

[0003] For example, in the lower body structure described in Patent Document 1, a structure including a tunnel portion protruding from the floor panel into the vehicle cabin and a pair of cross members extending in the vehicle width direction across the tunnel portion, a first tunnel member and a second tunnel member are arranged as multiple tunnel members at positions corresponding to the cross members in the fore-and-aft direction of the vehicle, i.e., at the positions between the pair of cross members.

[0004] The first tunnel member is disposed at the lower end of the tunnel section so as to cross the tunnel section in the vehicle width direction. The second tunnel member is disposed along the inner peripheral surface of the tunnel section. These first and second tunnel members suppress vibration of the floor panel and deformation of the tunnel section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-11856 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above structure, in order to improve the vibration suppression effect in a desired part of the vehicle body, it is necessary to improve the rigidity of the multiple reinforcing members such as the first and second tunnel members arranged in the desired part. In order to improve the rigidity of the multiple reinforcing members, it is necessary to increase the dimensions such as the plate thickness of each member, which makes it difficult to suppress an increase in the vehicle weight. Therefore, in a structure having multiple reinforcing members, there is a trade-off between vibration reduction and vehicle weight suppression, making it difficult to achieve both vibration reduction and vehicle weight suppression.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a vehicle body structure that is capable of improving vibration damping performance while suppressing the vehicle weight. [Means for solving the problem]

[0008] In order to solve the above problems, the vehicle body structure of the present invention includes a vehicle body fixing part fixed to a vehicle body, a first member having a first plane at a position different from the vehicle body fixing part, a second member having a second plane opposing the first plane and arranged in a state in which the second plane is superimposed on the first plane, and an adhesive vibration damping member provided between the first plane and the second plane, wherein the first member is: In the entire region of the first member in the longitudinal direction, The bending rigidity or torsional rigidity is set lower than that of the second member.

[0009] According to this configuration, the first member is fixed to the vehicle body at the vehicle body fixing portion, In the entire region of the first member in the longitudinal direction, The first member has a lower bending rigidity or torsional rigidity than the second member. Therefore, when vibration is transmitted from the vehicle body to the first member while the vehicle is running, the first member In the entire region of the first member in the longitudinal direction,The bending and twisting deformation is relatively large compared to the second member, and a large difference occurs between the strain of the first member and the strain of the second member. This results in a large relative displacement between the first plane of the first member and the second plane of the second member. As a result, it becomes possible to accumulate a large amount of strain energy in the adhesive vibration damping member provided between the first plane and the second plane, and it becomes possible to improve the vibration damping performance of the vehicle body. Furthermore, with this configuration, In the entire region of the first member in the longitudinal direction, Since the bending rigidity or torsional rigidity of the first member is set low, it is possible to reduce the weight of the first member. With the above configuration, it is possible to improve vibration damping performance while reducing the vehicle body weight.

[0010] In the above vehicle body structure, it is preferable that the second member is fixed only to the first member.

[0011] With this configuration, the vibration transmission path to the second member is only the first member, and the second member is not constrained to the vehicle body, so the relative displacement between the first plane of the first member and the second plane of the second member is maximized, which makes it possible to maximize the accumulation of strain energy in the vibration damping member between the first plane and the second plane.

[0012] In the above vehicle body structure, it is preferable that the second member is fixed to the first member only by the vibration damping member.

[0013] With this configuration, the second member is fixed to the first member only by the vibration damping member, and is not fixed by any fastening member other than the vibration damping member, so the vibration transmission path from the first member to the second member is only through the vibration damping member, which makes it possible to maximize the accumulation of strain energy in the vibration damping member.

[0014] In the body structure of the above-mentioned vehicle, it is preferable that the body comprises a floor panel that constitutes a floor portion of the body, and a floor tunnel that protrudes from the floor panel into the vehicle cabin, and that one of the first member and the second member is constituted by a lower plate that is arranged at the lower end of the floor tunnel, and the other of the first member and the second member is constituted by an upper plate that is located above the lower plate.

[0015] According to this configuration, since the first member and the second member are composed of a lower plate and an upper plate arranged at the lower end of the floor tunnel, it is possible to improve vibration damping performance in the floor tunnel and its surrounding areas.

[0016] In the above vehicle body structure, it is preferable that at least one of the lower plate and the upper plate has at least one of a convex portion and a concave portion extending in the vehicle width direction.

[0017] According to this configuration, at least one of the lower plate and the upper plate has at least one of a convex portion and a concave portion extending in the vehicle width direction, which improves rigidity in the vehicle width direction, and therefore it is possible to achieve both a function of damping vibration caused by torsion while the vehicle is traveling and a function of transmitting load in the vehicle width direction in the event of a side collision.

[0018] In the above-mentioned vehicle body structure, it is preferable that at least one of the lower plate and the upper plate has both the convex portion and the concave portion, and that the convex portion and the concave portion are arranged so as to alternate in the fore-and-aft direction of the vehicle.

[0019] With this configuration, at least one of the lower plate and the upper plate has a structure in which convex portions and concave portions are arranged alternately in the fore-and-aft direction of the vehicle, thereby further improving the rigidity in the vehicle width direction, thereby making it possible to further improve both the vibration damping function due to torsion and the load transmission function in the vehicle width direction.

[0020] In the body structure of the above-mentioned vehicle, it is preferable that at least one of the lower plate and the upper plate has a pair of the convex portions or a pair of the concave portions, and that the pair of convex portions or the pair of concave portions are arranged so that the convex portions or the concave portions intersect with each other when viewed from above the vehicle.

[0021] According to this configuration, at least one of the lower plate and the upper plate has a structure in which the convex portions or the concave portions intersect with each other when viewed from above the vehicle, thereby making it possible to further improve both the vibration damping function due to torsion and the load transmission function in the vehicle width direction.

[0022] In the vehicle body structure described above, it is preferable that the first plane and the second plane are configured by planes formed around the convex portion or the concave portion.

[0023] According to this configuration, the first plane and the second plane are formed by planes formed around the convex portion or the concave portion. This makes it possible to effectively transmit vibrations transmitted along the convex portion or the concave portion to the vibration damping member disposed between the first plane and the second plane around the convex portion or the concave portion. Therefore, even if the area where the vibration damping member is disposed is narrow, it is possible to effectively damp vibrations.

[0024] It is preferable that the above vehicle body structure further comprises a central fixing portion that fixes a central region in a longitudinal direction of the second member to the first member.

[0025] According to this configuration, the second member is fixed to the first member at a central region in the longitudinal direction of the second member by the central fixing part. In this configuration, even if the relative displacement between the first member and the second member is small in the central region in the longitudinal direction of the second member, depending on the vibration mode, the both ends in the longitudinal direction of the second member are not restrained by the central fixing part, so that it is possible to increase the relative displacement between the first member and the second member. Therefore, it becomes possible to accumulate strain energy in the vibration damping member provided between the first plane and the second plane. As a result, it becomes possible to secure vibration damping performance while fixing the second member to the first member by the central fixing part. Effect of the Invention

[0026] According to the vehicle body structure of the present invention, it is possible to improve vibration damping performance while suppressing the vehicle weight. [Brief description of the drawings]

[0027] [Figure 1] 1 is a perspective view of a vehicle body structure of a vehicle according to an embodiment of the present invention, as viewed from the front lower left. [Diagram 2] FIG. 2 is an exploded perspective view of the tunnel member of FIG. 1. [Diagram 3] FIG. 2 is a bottom view of the tunnel member and its surroundings in FIG. 1. [Figure 4] FIG. 4 is a bottom view showing the tunnel member of FIG. 3 with the lower plate removed. [Diagram 5] 4 is a bottom view showing the tunnel rain with all the tunnel members of FIG. 3 removed. FIG. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 3 is a perspective view of the lower plate of FIG. 2. [Figure 10] FIG. 2 is an explanatory diagram illustrating a schematic structure of the tunnel members of an example of the present invention and comparative examples 1 to 3. [Figure 11] 1 is a graph showing frequency characteristics of vibration levels in an example of the present invention and comparative examples 1 to 3. [Figure 12] FIG. 11 is a bottom view of a tunnel member and its surroundings, the tunnel member having a pair of downward protrusions intersecting in an X shape formed on the lower plate, showing a vehicle body structure according to a modified example of the present invention. [Figure 13] FIG. 13 is a bottom view showing the tunnel member of FIG. 12 with the lower plate removed. [Figure 14] 14 is a cross-sectional view taken along line XIV-XIV in FIG. 12. [Figure 15] 13 is a cross-sectional view taken along line XV-XV of FIG. 12. [Figure 16] FIG. 13 is a perspective view of the lower plate of FIG. 12. [Figure 17] FIG. 11 is a schematic perspective view of a vehicle body structure according to another modified example of the present invention, in which a vibration damping member is disposed between a roof panel and a roof rain. [Figure 18] FIG. 11 is a schematic perspective view of a vehicle body structure according to yet another modified example of the present invention, in which a vibration damping member is arranged between the shelf gusset and the rear pillar inner and the rear damper top. [Figure 19] FIG. 11 is a schematic perspective view of a vehicle body structure according to yet another modified example of the present invention, in which a vibration damping member is disposed between a floor panel and a cross member. [Figure 20] FIG. 11 is a schematic perspective view of a vehicle body structure according to yet another modified example of the present invention, in which a vibration damping member is disposed between a floor panel and an additional metal plate. [Figure 21] 21 is a cross-sectional view showing the laminated state of the floor panel, the vibration damping member, and the metal plate in FIG. 20. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0029] The body structure of the vehicle of this embodiment shown in Figure 1 comprises a floor panel 2 that constitutes the floor of the vehicle body 1, a floor tunnel 3 that protrudes from the floor panel 2 into the vehicle cabin, a tunnel member 4 arranged below the floor tunnel 3, and an adhesive vibration damping member 9 (see Figure 2) that is arranged between a lower plate 5 and an upper plate 6 (described below) that constitute the tunnel member 4.

[0030] As shown in Figures 3 to 8, the floor tunnel 3 is a semi-cylindrical member extending in the vehicle front-rear direction X at the center of the vehicle width direction Y of the vehicle body 1, and forms a space portion 3b (see Figures 6 to 8) that bulges upward Z1 and extends in the vehicle front-rear direction X. The space portion 3b is open to the lower side Z2 of the vehicle body 1, and can accommodate a drive shaft and an exhaust pipe (not shown). The floor tunnel 3 also has a pair of bolt attachment portions 3a (see Figures 3 to 4) that extend in the vehicle front-rear direction X on both sides of the space portion 3b in the vehicle width direction Y.

[0031] As shown in Figures 1 to 3, the tunnel member 4 is a flat member extending in the vehicle width direction Y, is disposed so as to cross the floor tunnel 3, and is fixed by bolts 7 to a pair of bolt attachment portions 3a (see Figures 3 and 6) at the lower end of the floor tunnel 3. The structure in which the tunnel member 4 is fixed to the lower end of the floor tunnel 3 contributes to improving the rigidity of the floor tunnel 3 and the central portion of the vehicle front-rear direction X of the vehicle body 1. The position of the tunnel member 4 in the vehicle front-rear direction X is not particularly limited in the present invention, but for example, the tunnel member 4 is disposed at a position in the vehicle front-rear direction X corresponding to a pair of cross members (not shown) that extend in the vehicle width direction Y across the floor tunnel 3.

[0032] 2 to 4 and 6 to 9, the tunnel member 4 includes a lower plate 5 disposed at the lower end of the floor tunnel 3, and an upper plate 6 located above the lower plate 5. In this embodiment, the lower plate 5 corresponds to the first member of the present invention, and the upper plate 6 corresponds to the second member.

[0033] The lower plate 5 has a plurality of flat plate portions 5a extending in the vehicle width direction Y, and a plurality of downward protruding portions 5b extending in the vehicle width direction Y. Each downward protruding portion 5b protrudes downward Z2 from between two flat plate portions 5a. Therefore, when the lower plate 5 is viewed in a cross section cut in the vehicle front-rear direction X as shown in Fig. 8, the flat plate portions 5a serving as convex portions protruding upward Z1 and the downward protruding portions 5b serving as concave portions protruding downward Z2 are arranged alternately in the vehicle front-rear direction X (i.e., a bellows structure).

[0034] As shown in Figs. 2 and 6, each flat plate portion 5a has a pair of vehicle body fixing portions 5c fixed to the vehicle body 1, and a first flat surface 5d.

[0035] The pair of vehicle body fixing portions 5c are disposed at both ends of the flat plate portion 5a in the vehicle width direction Y. A through hole 5e through which the bolt 7 passes is formed in the vehicle body fixing portion 5c. Note that the through hole 5e may be a slit that opens outward from an edge of the flat plate portion 5a in the vehicle width direction Y, as shown in FIG.

[0036] The first plane 5d is formed at a position different from the vehicle body fixing portion 5c, specifically, in an area sandwiched between the pair of vehicle body fixing portions 5c. The first plane 5d is formed by the upper surface of the flat plate portion 5a. In other words, the first plane 5d is formed by a plane formed around the downward protruding portion 5b.

[0037] 2, 4, and 6 to 8, the upper plate 6 has a plurality of flat plate portions 6a extending in the vehicle width direction Y, and a plurality of upward protruding portions 6b extending in the vehicle width direction Y. Each upward protruding portion 6b protrudes upward Z1 from between two flat plate portions 6a. Therefore, when the upper plate 6 is viewed in a cross section cut in the vehicle front-rear direction X as shown in FIG. 8, the flat plate portions 6a serving as recesses protruding downward Z2 and the upward protruding portions 6b serving as protrusions protruding upward Z1 are arranged alternately in the vehicle front-rear direction X (i.e., a bellows structure).

[0038] Each flat plate portion 6a has a second flat surface 6c facing the first flat surface 5d. The second flat surface 6c is formed by the lower surface of the flat plate portion 6a. In other words, the second flat surface 6c is formed by a flat surface formed around the upper protrusion 6b.

[0039] The length of the upper plate 6 in the vehicle width direction Y is set to be approximately the same as the length of the first plane 5d in the vehicle width direction Y. The upper plate 6 is disposed on the upper surface side of the lower plate 5 with the first plane 5d and the second plane 6c overlapping each other. In this state, the vehicle body fixing portions 5c of the lower plate 5 protrude on both sides of the upper plate 6 in the vehicle width direction Y. As a result, as shown in FIG. 2 and FIG. 6 to FIG. 8, with the lower plate 5 and the upper plate 6 of the tunnel member 4 overlapping each other, the pair of vehicle body fixing portions 5c are brought into contact with the pair of bolt attachment portions 3a of the floor tunnel 3, and the bolts 7 are passed through the through holes 5e of the vehicle body fixing portions 5c, thereby making it possible to fix the tunnel member 4 to the lower end of the floor tunnel 3 with the bolts 7.

[0040] In terms of the rigidity of the lower plate 5 and the upper plate 6, the lower plate 5 is set to have a lower bending rigidity or torsional rigidity than the upper plate 6. For example, the bending rigidity or torsional rigidity of the lower plate 5 can be set lower than that of the upper plate 6 by setting the plate thickness of the lower plate 5 thinner than that of the upper plate 6, or by using a material for the lower plate 5 that has a lower rigidity than the material for the upper plate 6.

[0041] The upper plate 6 is fixed only to the lower plate 5. That is, in this embodiment, the upper plate 6 is fixed to the lower plate 5 by a vibration damping member 9 and a central fixing portion 10.

[0042] Specifically, as shown in Figures 2, 6 and 8, an adhesive vibration damping material 9 is applied between the first plane 5d of the lower plate 5 and the second plane 6c of the upper plate 6, thereby bonding the lower plate 5 and the upper plate 6.

[0043] 3 to 4, the lower plate 5 and the upper plate 6 are fixed by a central fixing part 10 in a central region in the longitudinal direction of the lower plate 5 and the upper plate 6 (vehicle width direction Y in Figs. 3 to 4). The central fixing part 10 is formed by a fastening part such as spot welding, riveting, or bolt fastening. In this embodiment, the central fixing part 10 is provided in three places at a middle position in the longitudinal direction (vehicle width direction Y) of the lower plate 5 and the upper plate 6 and at positions on both sides of the middle position in the vehicle width direction Y, but may be provided in one place or four or more places in the central region in the longitudinal direction.

[0044] Furthermore, if the adhesive strength of the vibration damping member 9 is sufficient, the upper plate 6 may be fixed to the lower plate 5 by the vibration damping member 9 alone.

[0045] The vibration damping member 9 is provided between the first plane 5d of the lower plate 5 (first member) and the second plane 6c of the upper plate 6 (second member). The vibration damping member 9 has adhesive properties, and for example, a damping adhesive such as AD sealer is applied.

[0046] It is preferable that the vibration damping member 9 has viscoelasticity in order to reliably produce a vibration damping effect. Such a vibration damping member 9 having viscoelasticity is composed of, for example, an epoxy-based, urethane-based, or acrylic-based adhesive, and an additive (for example, a hardener, an inorganic or organic filler, or a moisture absorbent) added to the adhesive.

[0047] The vibration damping member does not have to be in the form of a paste adhesive, and any material or form may be used as long as it has adhesiveness and viscoelasticity.

[0048] Furthermore, if the vibration-damping member 9 has a loss factor of 0.2 or more and a storage modulus of 100 MPa or more under conditions of 20°C and 60 Hz, it can achieve a more significant vibration-damping effect than a structural adhesive. More preferably, if the loss factor is 0.3 to 0.4 and the storage modulus is 1000 MPa or more, it can achieve a more significant vibration-damping effect.

[0049] In the vehicle body 1 of this embodiment, as shown in Fig. 5 and Figs. 6 to 8, a tunnel rain 8 is disposed on the inner peripheral surface of the floor tunnel 3 at the same position as the tunnel member 4 in the vehicle front-rear direction X. The tunnel rain 8 is fixed so as to extend circumferentially along the inner peripheral surface of the floor tunnel 3, thereby reinforcing the floor tunnel 3. The tunnel rain 8 extends in the width direction of the floor tunnel 3 (i.e., the vehicle width direction Y) along the inner surface of the floor tunnel 3, and has a curved shape that protrudes upward.

[0050] (Features of this embodiment) (1) The vehicle body structure of this embodiment includes a lower plate 5 as a first member having a vehicle body fixing portion 5c fixed to the vehicle body 1 and a first plane 5d at a position different from the vehicle body fixing portion 5c, an upper plate 6 as a second member having a second plane 6c facing the first plane 5d and arranged with the second plane 6c overlapping the first plane 5d, and an adhesive vibration damping member 9 provided between the first plane 5d and the second plane 6c. The lower plate 5 is set to have a lower bending rigidity or torsional rigidity than the upper plate 6.

[0051] According to this configuration, the lower plate 5 is fixed to the vehicle body 1 at the vehicle body fixing portion 5c, and is set to have a lower bending rigidity or torsional rigidity than the upper plate 6. Therefore, when vibration is transmitted from the vehicle body to the lower plate 5 during vehicle travel, the lower plate 5 undergoes relatively larger bending and torsional deformation than the upper plate 6, and a large difference occurs between the distortion of the lower plate 5 and the distortion of the upper plate 6. Therefore, the relative displacement between the first plane 5d of the lower plate 5 and the second plane 6c of the upper plate 6 becomes large. As a result, it becomes possible to accumulate a large amount of strain energy in the adhesive vibration damping member 9 provided between the first plane 5d and the second plane 6c, and it becomes possible to improve the vibration damping performance of the vehicle body 1. In addition, in this configuration, since the bending rigidity or torsional rigidity of the lower plate 5 is set low, it becomes possible to suppress the weight of the lower plate 5. With the above configuration, it becomes possible to improve the vibration damping performance while suppressing the vehicle weight. This improves the handling stability and ride comfort of the vehicle.

[0052] (2) In the vehicle body structure of this embodiment, the upper plate 6 is fixed only to the lower plate 5. With this configuration, the vibration transmission path to the upper plate 6 is only the lower plate 5, and the upper plate 6 is not constrained to the vehicle body 1, so that the relative displacement between the first plane 5d of the lower plate 5 and the second plane 6c of the upper plate 6 is maximized. This makes it possible to maximize the accumulation of strain energy in the vibration damping member 9 between the first plane 5d and the second plane 6c.

[0053] (3) In the vehicle body structure of this embodiment, a vehicle body 1 includes a floor panel 2 that constitutes the floor of the vehicle body 1, and a floor tunnel 3 that protrudes from the floor panel 2 into the vehicle cabin. One of the first member and the second member (the first member in this embodiment) is composed of a lower plate 5 that is disposed at the lower end of the floor tunnel 3. The other of the first member and the second member (the second member in this embodiment) is composed of an upper plate 6 that is located above the lower plate 5.

[0054] According to this configuration, since the first member and the second member are composed of a lower plate 5 and an upper plate 6 arranged at the lower end of the floor tunnel 3, it is possible to improve vibration damping performance in the floor tunnel 3 and its surrounding areas.

[0055] In the present invention, it is sufficient that either the first member or the second member is composed of a lower plate 5 arranged at the lower end of the floor tunnel 3, and the other is composed of an upper plate 6 located above the lower plate 5. Therefore, the configuration may be reversed from that of the above embodiment, and specifically, the lower plate 5 may correspond to the second member of the present invention, and the upper plate 6 may correspond to the first member.

[0056] (4) In the vehicle body structure of this embodiment, at least one of the lower plate 5 and the upper plate 6 (both in this embodiment) has at least one of a convex portion and a concave portion extending in the vehicle width direction Y (both in this embodiment).

[0057] 2 and 8, the lower plate 5 has a flat plate portion 5a which is a convex portion protruding upward Z1 and a downward protruding portion 5b which is a concave portion protruding downward Z2, as a convex portion and a concave portion extending in the vehicle width direction Y. The upper plate 6 has a flat plate portion 6a which is a concave portion protruding downward Z2 and an upward protruding portion 6b which is a convex portion protruding upward Z1, as a convex portion and a concave portion extending in the vehicle width direction Y.

[0058] According to this configuration, at least one of the lower plate 5 and the upper plate 6 has at least one of a convex portion and a concave portion extending in the vehicle width direction Y. This improves the rigidity in the vehicle width direction Y. As a result, it is possible to achieve both a function of damping vibration caused by torsion while the vehicle is traveling and a function of transmitting load in the vehicle width direction Y during a vehicle side collision.

[0059] In addition, even if either one of the lower plate 5 and the upper plate 6 has either a convex portion or a concave portion extending in the vehicle width direction Y, it is possible to achieve the above-mentioned operational effect.

[0060] (5) In the vehicle body structure of this embodiment, at least one of the lower plate 5 and the upper plate 6 (both in this embodiment) has both a convex portion and a concave portion, and the convex portions and the concave portions are arranged so as to alternate in the vehicle fore-and-aft direction X. Specifically, as shown in Fig. 2 and Fig. 8, the lower plate 5 has an arrangement in which flat plate portions 5a that form convex portions and downward protruding portions 5b that form concave portions are arranged alternately in the vehicle fore-and-aft direction X (i.e., a bellows structure). The upper plate 6 has an arrangement in which flat plate portions 6a that form concave portions and upward protruding portions 6b that form convex portions are arranged alternately in the vehicle fore-and-aft direction X (i.e., a bellows structure).

[0061] According to this configuration, at least one of the lower plate 5 and the upper plate 6 has a structure in which the convex portions and the concave portions are alternately arranged in the vehicle fore-and-aft direction X, thereby further improving the rigidity in the vehicle width direction Y, thereby making it possible to further improve both the vibration damping function due to torsion and the load transmission function in the vehicle width direction Y.

[0062] The above-mentioned advantageous effects can be achieved even if either one of the lower plate 5 and the upper plate 6 has a structure in which convex portions and concave portions are alternately arranged in the vehicle front-rear direction X.

[0063] (6) In the vehicle body structure of the present embodiment, the first plane 5d and the second plane 6c are formed by planes formed around the convex or concave portions. Specifically, the first plane 5d is formed by a plane formed around the downward protruding portion 5b that becomes the concave portion. The second plane 6c is formed by a plane formed around the upward protruding portion 6b that becomes the convex portion.

[0064] As described above, the first plane 5d and the second plane 6c are configured by planes formed around the convex or concave portions, so that vibration transmitted along the convex or concave portion can be effectively transmitted to the vibration damping member 9 arranged between the first plane 5d and the second plane 6c around the convex or concave portion. Therefore, even if the area where the vibration damping member 9 is arranged is narrow, it is possible to effectively damp vibration.

[0065] (7) 3, the vehicle body structure of the present embodiment further includes a central fixing portion 10 that fixes the upper plate 6 to the lower plate 5. The central fixing portion 10 fixes the central region of the upper plate 6 in the longitudinal direction to the lower plate 5.

[0066] According to this configuration, the upper plate 6 is fixed to the lower plate 5 only in the central region in the longitudinal direction of the upper plate 6 by the central fixing part 10, and both ends in the longitudinal direction of the upper plate 6 are free ends. In this configuration, even if the relative displacement between the lower plate 5 and the upper plate 6 is small in the central region in the longitudinal direction of the upper plate 6, depending on the vibration mode, since both ends in the longitudinal direction of the upper plate 6 are not restrained by the central fixing part 10, it is possible to increase the relative displacement between the lower plate 5 and the upper plate 6. Therefore, it is possible to accumulate strain energy in the vibration damping member 9 provided between the first plane 5d and the second plane 6c. As a result, it is possible to ensure vibration damping performance while fixing the upper plate 6 to the lower plate 5 by the central fixing part 10.

[0067] For example, in the case of the floor membrane mode (a mode in which the floor panel 2 vibrates as a membrane) when vibration is input to the vehicle body 1, the deformation mode of the tunnel member 4 is primary bending, so even if the central fixing part 10 is welded or mechanically joined near the center of the tunnel member 4, where the strain energy is small, the vibration damping effect of the vibration damping member 9 is not hindered.

[0068] (Example) Next, the attenuation characteristics of the tunnel members of the example of the present invention and comparative examples 1 to 3 will be compared with each other with reference to FIGS.

[0069] 10, tunnel members 74 of comparative examples 1 to 3 are all configured by overlapping lower plate 75 and upper plate 76 having a bellows structure with concave and convex portions aligned in the vehicle width direction, which is common to the overlapping structure of tunnel member 4 of the embodiment. However, tunnel members 74 of comparative examples 1 to 3 are significantly different from the structure of the embodiment in that both lower plate 75 and upper plate 76 are fastened to the lower end of floor tunnel 3 with bolts 7, in that only lower plate 5 is fastened to the lower end of floor tunnel 3 with bolts 7.

[0070] In addition, in the tunnel member 74 of Comparative Example 1 (I in FIG. 10: base (SW)), a flat portion 75a of a lower plate 75 and a flat portion 76a of an upper plate 76 are spot welded (see spot welded portion 80).

[0071] In tunnel member 74 of Comparative Example 2 (II in FIG. 10: SW+damping member), flat plate portion 75a of lower plate 75 and flat plate portion 76a of upper plate 76 are bonded with damping adhesive 79 and spot welded (see spot welds 80).

[0072] In a tunnel member 74 of Comparative Example 3 (III in FIG. 10: damping member), a flat portion 75a of a lower plate 75 and a flat portion 76a of an upper plate 76 are bonded with a damping adhesive 79, but are not spot-welded.

[0073] In the tunnel member 74 of the example (IV in FIG. 10: damping member), the flat plate portion 5a of the lower plate 5 and the flat plate portion 6a of the upper plate 6 are bonded with an adhesive vibration damping member 9 as in the above embodiment. A common damping adhesive such as AD sealer is used as the vibration damping member 9 of the example and the damping adhesive 79 of Comparative Examples 2 and 3.

[0074] FIG. 11 is a graph showing frequency characteristics of vibration levels when vibration is applied to a vehicle body provided with the tunnel member 4 of the embodiment and the tunnel members 74 of the comparative examples 1 to 3 as described above.

[0075] According to the graph in Fig. 11, in torsion mode M2 ​​(deformation mode in which the vehicle body 1 is twisted around a central axis extending in the vehicle longitudinal direction X as the axis of rotation) where the input vibration frequency is around 40 Hz, Comparative Examples 1 to 3 (curves I to III in Fig. 11) and the Example (curve IV in Fig. 11) have almost the same vibration level. However, in the floor membrane mode (mode in which the floor panel 2 vibrates) where the input vibration frequency is around 70 Hz, although Comparative Examples 1 to 3 (curves I to III) have similar vibration levels, only the Example (curve IV) has a lower vibration level than Comparative Examples 1 to 3, indicating that the vibration damping function is improved.

[0076] 11, in the tunnel member 4 of the embodiment, only the lower plate 5 is fastened to the lower end of the floor tunnel 3 with the bolts 7, and the lower plate 5 is not restrained from the floor tunnel 3, so that the strain energy absorbed by the vibration damping member 9 increases with an increase in the relative displacement between the lower plate 5 and the upper plate 6, and it is clear that the vibration damping function is improved. On the other hand, in the comparative examples 1 to 3, in the structure in which both the lower plate 75 and the upper plate 76 are fastened to the lower end of the floor tunnel 3 with the bolts 7, the relative displacement between the lower plate 75 and the upper plate 76 remains almost unchanged, so that the absorption of the strain energy absorbed by the damping adhesive 79 between the lower plate 75 and the upper plate 76 is also small, and it is understood that the vibration damping function is not as improved as in the embodiment.

[0077] (Modification) (A) In the vehicle body structure of the above embodiment, the upper plate 6 is fixed to the lower plate 5 by both the vibration damping member 9 (see Figures 2, 6, 8-9) and the central fixing part 10 (see Figure 3), but the upper plate 6 may be fixed to the lower plate 5 only by the vibration damping member 9.

[0078] According to this configuration, the upper plate 6 is fixed to the lower plate 5 only by the vibration damping member 9, and is not fixed by any fastening member other than the vibration damping member 9, so that the vibration transmission path from the lower plate 5 to the upper plate 6 is only through the vibration damping member 9. Therefore, it is possible to maximize the accumulation of strain energy in the vibration damping member 9.

[0079] (B) In the vehicle body structure of the above embodiment, the lower plate 5 is attached to the lower end of the floor tunnel 3 of the vehicle body 1, but the present invention is not limited to this, and the reverse structure may also be used. That is, the upper plate 6 may be attached to the lower end of the floor tunnel 3 of the vehicle body 1, and the lower plate 5 may be fixed only to the upper plate 6 (for example, fixed only by the vibration damping member 9, or fixed by both the vibration damping member 9 and the central fixing part 10). That is, the upper plate 6 may correspond to the first member of the present invention, and the lower plate 5 may correspond to the second member. In this case, it is possible to achieve the same effects as those of (1) to (7) of the above embodiment.

[0080] (C) In addition, the vehicle body structure of the present invention may be such that the first member is fixed to the vehicle body, the second member is arranged overlapping the first member, an adhesive vibration damping member is arranged between the first plane of the first member and the second plane of the second member, and the first member is set to have a lower bending rigidity or torsional rigidity than the second member. Therefore, the present invention is not limited to a structure in which the second member is fixed only to the first member (i.e., a structure in which the upper plate 6 is fixed only to the lower plate 5 as in the above embodiment), and the second member may be fixed to any part of the vehicle body at a part other than the first member and by a different fixing means, as long as the relative displacement between the first plane and the second plane can be ensured. For example, the lower plate 5, which is the first member, may be fastened to the lower end of the floor tunnel 3 with a bolt 7, while the upper plate 6, which is the second member, may be weakly connected to the inner surface of the floor tunnel 3 with an elastic member.

[0081] (D) In the vehicle body structure of the above embodiment, as shown in Figs. 2 and 8, the lower plate 5 and the upper plate 6 have a bellows structure in which convex portions and concave portions are alternately arranged in the vehicle fore-and-aft direction X. However, the present invention is not limited to this.

[0082] As a modified example of the present invention, at least one of the lower plate 5 and the upper plate 6 may have a pair of convex portions or a pair of concave portions, and the pair of convex portions or the pair of concave portions may be arranged so that the convex portions or the concave portions intersect with each other when viewed from above the vehicle.

[0083] Specifically, a tunnel member 24 shown in Fig. 12, which is a modified example of the present invention, includes a lower plate 25 (see Figs. 12 and 15-16) that is substantially X-shaped when viewed from the bottom of the vehicle body, and an upper plate 26 (see Figs. 13-15) that has a shape corresponding to the lower plate 25. The lower plate 25 corresponds to the first member of the present invention, and the upper plate 26 corresponds to the second member.

[0084] The lower plate 25 has a pair of downward protruding portions 25b extending in the vehicle width direction Y and intersecting each other in a plan view of the vehicle, and flat plate portions 25a arranged on both sides of the downward protruding portions 25b in the vehicle front-rear direction X. The downward protruding portions 25b are convex portions that protrude downward Z2 between the flat plate portions 25a. The flat plate portion 25a has four vehicle body fixing portions 25c arranged at both ends in the vehicle width direction Y, and a first flat surface 25d arranged in an area other than the four vehicle body fixing portions 25c. The four vehicle body fixing portions 25c are fixed to the bolt mounting portions 3a of the floor tunnel 3 with bolts 7.

[0085] The upper plate 26 is a member having a flat plate portion 26a that is substantially X-shaped or rectangular with parts of the four sides cut out and that can cover the entire lower plate 25 that is substantially X-shaped when viewed from the bottom of the vehicle body. The flat plate portion 26a has a second flat surface 26c that faces the first flat surface 25d of the lower plate 25.

[0086] The vibration damping member 9 is disposed between the first plane 25d and the second plane 26c, similarly to the above embodiment.

[0087] 12 to 16, at least one of the lower plate 25 and the upper plate 26 (lower plate 25 in this modification) has a structure in which the convex portions or the concave portions (the downward protruding portions 25b which are convex portions in this modification) intersect with each other in a plan view of the vehicle. This makes it possible to further improve both the vibration damping function due to torsion and the load transmission function in the vehicle width direction Y.

[0088] Also in this modified example, the upper plate 26 is adhered to the lower plate 25 by the vibration damping member 9, and is fixed to the lower plate 25 only in the central region in the longitudinal direction of the upper plate 26 (vehicle width direction Y in FIG. 12) by the central fixing part 30 (see FIG. 12). As a result, it is possible to ensure vibration damping performance while fixing the upper plate 26 to the lower plate 25 by the central fixing part 30.

[0089] (E) In the above embodiment and variant examples, a structure in which tunnel members 4, 24 having lower plates 5, 25 and upper plates 6, 26, which are the first members, are arranged at the lower end of a floor tunnel 3 has been described as an example of a body structure of a vehicle of the present invention, but the present invention is not limited to this.

[0090] As shown in Figs. 17 to 21, the vehicle body structure of the present invention can be applied to various parts other than the tunnel member, and in that case too, it becomes possible to improve vibration damping performance while suppressing the vehicle body weight.

[0091] For example, in the modified example shown in FIG. 17, the present invention can be applied to a structure having a roof member 31 (first member) constituting a roof portion of a vehicle interior and a plurality of roof rains 32 (second members) arranged so as to extend in the vehicle width direction Y on the lower surface of the roof member 31, as described below. In this configuration, the periphery of the roof member 31 is fixed to the frame of the vehicle body. A pair of flange portions 32a provided on each roof rain 32 faces the lower surface of the roof member 31. An adhesive vibration damping member 33 such as AD sealer is arranged between the lower surface (first plane) of the roof member 31 and the upper surface (second plane) of the flange portions 32a. The roof member 31 is set to have a lower bending rigidity or torsional rigidity than the roof rain 32. In the configuration of FIG. 17, the roof rain 32 is bonded to the roof member 31 only by the vibration damping member 33. As a result, the relative displacement between the roof rain 32 and the roof member 31 becomes large when vibration is input, so that it is possible to improve the vibration damping performance while suppressing the vehicle weight.

[0092] (F) In addition, in the modified example shown in FIG. 18, the present invention can also be applied to a structure on the inner surface of the rear part of the vehicle body, which has a rear pillar inner 41 (first member), a rear damper top 42 (first member) arranged on the rear side of the rear pillar inner 41, and a shelf gusset 43 (second member) which is a reinforcing member connecting the rear pillar inner 41 and the rear damper top 42. In this configuration, the rear pillar inner 41 and the rear damper top 42 are fixed to the frame of the vehicle body. A pair of flange parts 43a provided on the shelf gusset 43 face the inner surfaces of the rear pillar inner 41 and the rear damper top 42. An adhesive vibration damping member 44 such as an AD sealer is arranged between the inner surfaces (first planes) of the rear pillar inner 41 and the rear damper top 42 and the surfaces (second planes) of the pair of flange parts 43a facing the inner surfaces. The rear pillar inner 41 and the rear damper top 42 are set to have lower bending rigidity or torsional rigidity than the shelf gusset 43. In the configuration in Fig. 18, the shelf gusset 43 is adhered to the rear pillar inner 41 and the rear damper top 42 only by the vibration damping member 44. This increases the relative displacement between the shelf gusset 43 and the rear pillar inner 41 and the rear damper top 42 when vibration is input, making it possible to improve vibration damping performance while suppressing the vehicle body weight.

[0093] (G) Furthermore, in the modified example shown in FIG. 19, the present invention can be applied to a structure having a floor panel 51 (first member) constituting the floor portion of the vehicle compartment, and a pair of cross members 52 (second members) arranged so as to extend in the vehicle width direction Y on the upper surface of the floor panel 51. In this configuration, the periphery of the floor panel 51 is fixed to the frame of the vehicle body. A pair of flange portions 52a provided on each cross member 52 faces the upper surface of the floor panel 51. An adhesive vibration damping member 53 such as AD sealer is arranged between the upper surface (first plane) of the floor panel 51 and the lower surface (second plane) of the flange portion 52a of the cross member 52. The bending rigidity or torsional rigidity of the floor panel 51 is set lower than that of the cross member 52. In the configuration of FIG. 19, the cross member 52 is bonded to the floor panel 51 only by the vibration damping member 53. As a result, the relative displacement between the cross member 52 and the floor panel 51 becomes large when vibration is input, so that it is possible to improve the vibration damping performance while suppressing the vehicle weight.

[0094] In addition, the cross member 52 and the patch inside the cross member 52 may also be bonded with a vibration damping member 53 to further improve the vibration damping performance.

[0095] (H) Furthermore, in the modified example shown in Figs. 20-21, the present invention can be applied to a structure having a floor panel 61 (first member) constituting the floor portion of the vehicle compartment, and an additional metal plate 62 (second member) arranged on the upper surface side of the floor panel 61. In this configuration, the periphery of the floor panel 61 is fixed to the frame of the vehicle body. An adhesive vibration damping member 63 such as AD sealer is arranged between the upper surface (first plane) of the floor panel 61 and the lower surface (second plane) of the additional metal plate 62. The bending rigidity or torsional rigidity of the floor panel 61 is set to be lower than that of the additional metal plate 62.

[0096] 20-21, additional metal plate 62 is adhered to floor panel 61 only by vibration damping member 63. This increases the relative displacement between additional metal plate 62 and floor panel 61 when vibration is input, making it possible to improve vibration damping performance while suppressing the vehicle weight. [Explanation of symbols]

[0097] 1. Vehicle body 2 Floor Panel 3 Floor Tunnel 4 Tunnel Members 5, 25 Lower plate (first component) 5a Flat plate part (convex part) 5b, 25b Downward protrusion (recess) 5c Body fixing part 5d, 25d 1st plane 6, 26 Upper plate (second member) 6a, 26a Flat plate portion (recess) 6b Upper protrusion (convex part) 6c, 26c 2nd plane 7 Volts 9. Vibration damping material 10, 30 Central fixed part

Claims

1. A vehicle body structure, a first member having a vehicle body fixing portion fixed to a vehicle body and a first flat surface at a position different from the vehicle body fixing portion; a second member having a second plane opposite to the first plane and disposed in a state in which the second plane is superimposed on the first plane; a vibration damping member having adhesive properties and provided between the first plane and the second plane; Equipped with The first member has a bending rigidity or a torsional rigidity set lower than that of the second member in the entire region of the first member in the longitudinal direction. A vehicle body structure comprising:

2. The vehicle body structure according to claim 1, The second member is fixed only to the first member. A vehicle body structure comprising:

3. The vehicle body structure according to claim 1, The second member is fixed to the first member only by the vibration damping member. A vehicle body structure comprising:

4. The vehicle body structure according to any one of claims 1 to 3, The vehicle body includes a floor panel that configures a floor portion of the vehicle body; a floor tunnel protruding from the floor panel into the vehicle interior; Equipped with One of the first member and the second member is composed of a lower plate arranged at a lower end of the floor tunnel, The other of the first member and the second member is configured with an upper plate located above the lower plate. A vehicle body structure comprising:

5. The vehicle body structure according to claim 4, At least one of the lower plate and the upper plate has at least one of a convex portion and a concave portion extending in the vehicle width direction, A vehicle body structure comprising:

6. The vehicle body structure according to claim 5, At least one of the lower plate and the upper plate has both the protrusion and the recess; The protruding portions and the recessed portions are arranged alternately in the front-rear direction of the vehicle. A vehicle body structure comprising:

7. The vehicle body structure according to claim 5, At least one of the lower plate and the upper plate has a pair of the protruding portions or a pair of the recessed portions, The pair of convex portions or the pair of concave portions are arranged so that the convex portions or the concave portions intersect with each other in a plan view of the vehicle. A vehicle body structure comprising:

8. The vehicle body structure according to any one of claims 5 to 6, The first plane and the second plane are configured by planes formed around the convex portion or the concave portion. A vehicle body structure comprising:

9. In the vehicle body structure according to any one of claims 1 to 2 and claims 4 to 7, The second member further includes a central fixing portion that fixes a central region in a longitudinal direction of the second member to the first member. A vehicle body structure comprising:

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