Vibration damping structure

Abstract

To provide a vibration control structure capable of improving a vibration reduction effect without excessively increasing a vibration control material.SOLUTION: The damping structure includes a panel member, a damping material 2, and a restriction layer 3. The damping member 2 has a plurality of protruding stripe portions 11 each of which is continuous along a first direction D1 that is a direction in which the damping member 2 is pulled or compressed when a bending load is input to the panel member, and which are arranged apart from each other on a second direction D1 orthogonal to the first direction D2, and a plurality of recessed stripe portions 12 each of which is formed between two adjacent protruding stripe portions 11 of the plurality of protruding stripe portions 11. The constraining layer 3 is impregnated into the recessed portion 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration damping structure for a panel member such as a floor panel of a vehicle. [Background technology]

[0002] Various structures have been proposed to reduce vibrations in floor panels that constitute the floor of a vehicle while the vehicle is running. For example, as described in Patent Document 1, a structure is known in which a vibration-damping material with damping properties, such as asphalt-based resin, is applied to low-rigidity areas of the floor panel that are prone to vibration.

[0003] In such a structure where vibration-damping material is applied to the floor panel, the vibration energy transmitted from the vehicle frame to the floor panel while the vehicle is moving is converted into heat energy by the vibration-damping material, thereby reducing the vibration of the floor panel. As a result, ride comfort and NVH performance (i.e., the ability to reduce noise, vibration, and harshness) are improved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-315627 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above structure, the amount of vibration-damping material must be increased in order to further improve the vibration-reducing effect, so there is room for improvement in terms of manufacturing costs and the vibration-damping effect relative to the mass of the vibration-damping material.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a vibration-damping structure that can improve the vibration-reducing effect without excessively increasing the amount of vibration-damping material. [Means for solving the problem]

[0007] In order to solve the above problem, the vibration-damping structure of the present invention comprises a panel member, a vibration-damping material fixed to at least one surface of the panel member, and a constraining layer that is less likely to deform than the vibration-damping material and is fixed to the surface of the vibration-damping material opposite the panel member, wherein the vibration-damping material has a plurality of convex rib portions that are continuous along a first direction in which the vibration-damping material is pulled or compressed when a bending load is input to the panel member, and are arranged spaced apart from each other in a second direction perpendicular to the first direction, and a plurality of concave rib portions formed between two adjacent convex rib portions of the plurality of convex rib portions, and the constraining layer is impregnated into the concave rib portions.

[0008] According to this configuration, the damping material has multiple ridges. These ridges are each continuous along a first direction, which is the direction in which the damping material is tensile or compressed when a bending load is applied to the panel member, and are spaced apart from each other in a second direction perpendicular to the first direction. Therefore, these ridges increase the moment of inertia of the damping material, thereby improving the bending rigidity of the damping material. Furthermore, the constraint layer impregnated in the grooves of the damping material constrains the two ridges on both sides of the grooves, further improving the bending rigidity of the damping material. Therefore, when a bending load is applied to the panel member, the amount of strain energy stored in the damping material increases in response to the shear input generated in the damping material fixed to the panel member, thereby improving the vibration reduction effect.

[0009] In the above vibration-damping structure, it is preferable that the panel member is a floor panel that constitutes the floor of the vehicle, the floor panel is fixed to a frame extending in the fore-and-aft direction of the vehicle body, the vibration-damping material extends in a transverse direction that intersects the fore-and-aft direction of the vehicle and is fixed to the floor panel, and the multiple convex rib portions are arranged with the transverse direction as a first direction.

[0010] In this configuration, the panel member is a floor panel that constitutes the vehicle floor, and the floor panel is fixed to a frame extending in the vehicle's longitudinal direction. Therefore, the floor panel's bending rigidity in the vehicle's longitudinal direction is strong due to the reinforcing effect of the frame. In contrast, the bending rigidity in a transverse direction intersecting the vehicle's longitudinal direction, particularly the vehicle width direction, is weak due to the low reinforcing effect of the frame. Therefore, the floor panel is most susceptible to bending deformation in the vehicle width direction when subjected to external vibrations. Therefore, in this configuration, the vibration-damping material extends in a transverse direction intersecting the vehicle's longitudinal direction and is fixed to the floor panel, and multiple ridges are continuous in the transverse direction. Furthermore, the continuous ridges in the transverse direction are constrained by a constraining layer. This increases the rigidity of the vibration-damping material, allowing strain energy to be stored in the vibration-damping material. As a result, the vibration-damping effect can be improved.

[0011] In the above vibration damping structure, it is preferable that the vibration damping material extends in a vehicle width direction perpendicular to the vehicle fore-and-aft direction and is fixed to the floor panel, and that the multiple convex rib portions are arranged with the vehicle width direction as a first direction.

[0012] In this configuration, the damping material extends in the vehicle width direction, which is the direction in which the bending stiffness of the floor panel is weakest, and the multiple ridges are continuous in the vehicle width direction, allowing more strain energy to be accumulated in the damping material, thereby further improving the vibration damping effect.

[0013] In the above vibration-damping structure, it is preferable that the panel member is a floor panel that constitutes the floor of the vehicle, the floor panel has a curved portion that is curved downward or upward, and the vibration-damping material is fixed to the curved portion.

[0014] When a floor panel has a curved portion that protrudes downward or upward, the curved portion has weaker bending rigidity than other flat portions of the floor panel. Therefore, with the above-described configuration, the vibration-damping material is fixed to the curved portion of the floor panel, which has weak bending rigidity. This allows strain energy to be stored in the vibration-damping material, whose rigidity is increased by the constraining layer between the convex ribs as described above. As a result, it is possible to improve the vibration-damping effect.

[0015] In the above-mentioned vibration-damping structure, it is preferable that the vibration-damping material is fixed to the curved-shaped portion in multiple locations spaced apart from each other around the center so as to extend radially from the center of the curved-shaped portion in the centrifugal direction when viewed from one side in the vertical direction, and that the multiple convex rib portions are arranged with the centrifugal direction as the first direction.

[0016] With this configuration, the bending rigidity in the direction from the center to the periphery of the curved portion is particularly weak, so by configuring it as described above, more strain energy can be accumulated in the vibration-damping material, thereby further improving the vibration-damping effect.

[0017] In the above vibration damping structure, the curved portion is preferably a spare tire pan for accommodating a spare tire.

[0018] According to this configuration, the spare tire pan is a curved portion with a relatively large diameter that can accommodate a spare tire. The bending rigidity of such a spare tire pan is particularly weak compared to the bending rigidity of other portions of the floor panel. Therefore, by affixing the vibration-damping material to the spare tire pan, strain energy can be stored in the vibration-damping material. As a result, the vibration-damping effect of the spare tire pan can be improved.

[0019] In the above vibration control structure, it is preferable that the floor panel is fixed to a plurality of cross members in the vehicle body that are spaced apart in the fore-and-aft direction of the vehicle and extend in the width direction of the vehicle, and that the curved portion is part of the area of ​​the floor panel between the plurality of cross members.

[0020] With this configuration, the bending rigidity of the curved floor panel between the cross members is particularly weak, and by attaching the vibration-damping material to this area, more strain energy can be stored in the vibration-damping material, thereby improving the vibration damping effect in the area between the cross members of the floor panel.

[0021] In the above vibration-damping structure, it is preferable that the vibration-damping material extends in the vehicle width direction in the region between the cross members, and the plurality of convex stripes are provided with the vehicle width direction as a first direction.

[0022] With this configuration, since the bending rigidity in the vehicle width direction is particularly weak in the area between the cross members, the vibration-damping material extends in the vehicle width direction and is fixed to that area, and the multiple convex portions of the vibration-damping material are continuous in the vehicle width direction, so that more strain energy can be accumulated in the vibration-damping material, thereby further improving the vibration-damping effect in the area between the cross members.

[0023] In the above vibration-damping structure, the constraining layer is preferably made of a material for clear coating.

[0024] According to this configuration, it is possible to realize the vibration damping structure described above using conventional vehicle manufacturing equipment that performs clear coating.

[0025] In the above vibration-damping structure, the vibration-damping material is preferably disposed in a region of the floor panel below the seat.

[0026] With this configuration, vibrations that occur in the area of ​​the floor panel below the seat are easily sensed by occupants, so by placing vibration-damping material in this area, the vibrations of the floor panel are less likely to be sensed by occupants, thereby improving comfort.

[0027] In the above vibration-damping structure, the constraining layer preferably covers the entirety of the plurality of ridges and grooves of the vibration-damping material.

[0028] With this configuration, the constraining layer covers the entirety of the multiple ridges and grooves of the damping material, making it possible to firmly constrain the multiple ridges as a whole. This further improves the bending rigidity of the damping material. Therefore, the amount of strain energy stored in the damping material is further improved, making it possible to further improve the vibration reduction effect. [Effects of the Invention]

[0029] As described above, the vibration damping structure of the present invention can improve the vibration reduction effect without excessively increasing the amount of vibration damping material. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a partially cutaway perspective view showing the overall configuration of a vibration damping structure according to an embodiment of the present invention. [Figure 2] 2A and 2B are diagrams for explaining shear deformation of the damping material due to bending deformation of the panel member caused by the vibration of FIG. 1, where (a) is a comparative example showing that no shear deformation occurs when there is no constraining layer, and (b) is a diagram showing the present embodiment showing that shear deformation occurs due to the constraint of the damping material by the constraining layer. [Figure 3] 2A and 2B are diagrams showing the distribution of strain energy accumulated in the damping material due to bending deformation of the panel member of FIG. 1, where (a) is a diagram showing, as a comparative example, that the accumulated strain energy is small when there is no constraining layer, and (b) is a diagram showing, as this embodiment, that the accumulated strain energy is large due to the constraint of the damping material by the constraining layer. [Figure 4]1A and 1B are diagrams showing the process by which strain energy accumulates at the corners of the convex rib portion and the corners of the concave rib portion of the vibration-damping material of this embodiment in response to vibration input, where (a) is a diagram of the state before vibration, and (b) is a diagram of the state in which strain energy accumulates at the corners during vibration. [Figure 5] The figures show examples of vibration-damping structures for investigating vibration reduction effects, with I to III showing structures having 1 to 3 layers of vibration-damping material as the present embodiment and a constraining layer fixed to the topmost layer of vibration-damping material, and IV to VI showing structures having only 1 to 3 layers of vibration-damping material and no constraining layer as comparative examples. [Figure 6] FIG. 1 is a diagram schematically illustrating a test specimen in which a vibration-damping material corresponding to this embodiment is applied vertically to a panel member. [Figure 7] 7 is a graph showing the relationship between the frequency of the input vibration wave and the inertance when the vibration control structure in which the structures I to VI in FIG. 5 are applied to the test specimen in FIG. 6 as this embodiment and the structure X consisting only of a panel member are vibrated. [Figure 8] FIG. 10 is a diagram schematically illustrating a structure in which a vibration-damping material is horizontally applied to a panel member as a comparative example. [Figure 9] 9 is a graph showing the relationship between the frequency of the input vibration wave and the inertance when a vibration control structure in which structures I to VI of FIG. 5 are applied to a test body of FIG. 8 as a comparative example, and a structure X consisting only of a panel member are vibrated. [Figure 10] 2 is an explanatory diagram schematically showing the application direction and two bending directions of the vibration-damping material of the present embodiment. FIG. [Figure 11] 1 is a perspective view showing a structure in which the vibration damping structure of the present embodiment is applied to a floor panel of a vehicle. [Figure 12] 1 is an enlarged perspective view showing a structure in which the vibration damping structure of the present embodiment is applied to a spare tire pan, which is a curved portion of a floor panel of a vehicle, and in which a plurality of vibration damping materials extend radially. FIG. [Figure 13] 1 is an enlarged perspective view showing a structure in which the vibration damping structure of the present embodiment is applied to a spare tire pan having an opening that is a curved portion of a floor panel of a vehicle. FIG. [Figure 14]14 is an enlarged plan view showing a plurality of vibration-damping materials extending radially from a ridge line formed around the opening in FIG. 13. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, a vibration damping structure according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0032] As shown in Fig. 1, the vibration-damping structure of this embodiment includes a plate-shaped panel member 1, a vibration-damping material 2 adhered by coating or the like to at least one surface of the panel member 1, in this embodiment, the upper surface 1a, and a constraining layer 3 adhered to the surface of the vibration-damping material 2 opposite the panel member 1, in this embodiment, the upper surface 2c. In this vibration-damping structure, the panel member 1, the vibration-damping material 2, and the constraining layer 3 are stacked in this order and bonded to each other to form a three-layer laminated structure. Note that the vibration-damping material 2 and the constraining layer 3 may be adhered to the lower surface 1c of the panel member 1, or may be adhered to both the upper surface 1a and the lower surface 1c of the panel member 1.

[0033] The panel member 1 is a plate-like member attached to a location that receives external vibrations, and is used, for example, in a floor panel 21 (see FIGS. 11 to 13) that constitutes the floor of a vehicle, which will be described later. The panel member 1 is used with at least both opposing end portions 1b, and preferably the end portions around the entire periphery of the panel member 1, fixed. The present invention does not particularly limit the material of the panel member 1, but when used in a floor panel 21 of an automobile, a thin steel plate or the like is used.

[0034] The damping material 2 is fixed to the upper surface 1a of the panel member 1 by coating or pasting. The damping material 2 is made of a material that has the ability to attenuate vibrations transmitted to the panel member 1, and is made of a material such as acrylic emulsion paint, or more specifically, a material containing various foaming agents that foam when heated, such as acrylic emulsion paint, polyurethane resin paint, epoxy resin paint, or vinyl chloride plastisol paint. The damping material 2 only needs to have sufficient rigidity or elasticity to exhibit vibration damping performance, and for example, a Young's modulus of approximately 400 to 700 MPa is sufficient, and the above-mentioned acrylic emulsion paint has a Young's modulus of approximately 600 MPa.

[0035] The damping material 2 used in this embodiment is made of a resin that foams and hardens on heating, consisting of an acrylic emulsion paint applied in a predetermined first direction D1, as shown in Figure 1. Therefore, the damping material 2 has a layer containing air bubbles deposited on the upper surface 1a of the panel member 1. Because the damping material 2 contains air bubbles, it is able to damp the vibration of the panel member 1 by storing the vibration energy transmitted to the panel member 1 as strain energy.

[0036] The vibration-damping material 2 also has a plurality of ridges 11 and a plurality of grooves 12 on its upper surface 1a.

[0037] The plurality of ridge portions 11 are continuous (i.e., extend) along a first direction D1, which is a direction in which the vibration-damping material 2 is pulled or compressed, when a bending load B is applied to the panel member 1, specifically, when a bending load B caused by external vibration is applied to the panel member 1 to which both opposing end portions 1b are fixed. The plurality of ridge portions 11 are also arranged at intervals from one another in a second direction D2 that is perpendicular to the first direction D1.

[0038] Each of the plurality of recessed streaks 12 is formed between two adjacent protruding streaks 11.

[0039] The multiple convex ribs 11 are formed by applying an acrylic emulsion paint or the like that will become the vibration-damping material 2 from multiple nozzles to the upper surface 1a of the panel member 1 so that it extends in the first direction D1, and then heating the paint to foam and harden the surface. Therefore, each convex rib 11 is a continuous body extending in the first direction D1 and having a substantially semicircular or substantially rectangular cross section. Meanwhile, the concave rib 12 formed between two adjacent convex ribs 11 is a groove extending in the first direction D1 and having a shape that corresponds to the opposing surfaces of the two adjacent convex ribs 11.

[0040] The constraining layer 3 is fixed by coating or the like to the surface of the damping material 2 opposite to the panel member 1, that is, to the upper surface 2c in this embodiment.

[0041] The constraining layer 3 is made of a material that is less prone to deformation than the damping material 2, such as an acrylic resin that is used for clear coating the surface of a vehicle during vehicle manufacture. The constraining layer 3 only needs to have properties that make it less prone to deformation than the damping material 2 (for example, high rigidity and high elasticity), and for example, a Young's modulus of approximately 1300 to 2000 MPa is sufficient, and the above-mentioned acrylic resins have a high Young's modulus of approximately 1650 MPa. Therefore, the constraining layer 3 has higher elasticity than the damping material 2, and is therefore less prone to bending deformation or tensile / compressive deformation.

[0042] The constraining layer 3 needs to be impregnated into at least the groove portion 12. This makes it possible to constrain the protrusions 11 on both sides of the groove portion 12 by the constraining layer 3 impregnated into the groove portion 12.

[0043] In this embodiment, as shown in FIG. 1, the constraining layer 3 entirely covers the plurality of ridges 11 and grooves 12 of the vibration-damping material 2 .

[0044] (Explanation of the vibration damping mechanism of the vibration control structure) The vibration damping mechanism of the vibration damping structure of this embodiment will be described below.

[0045] First, the mechanism by which the constraining layer 3 in the vibration-damping structure of this embodiment increases the strain energy of the vibration-damping material 2 will be described.

[0046] As a comparative example, in the structure shown in Figure 2(a) in which only the damping material 2 is laminated on the panel member 1, when a bending load B is input to the panel member 1 and the damping material 2 is pulled in the first direction D1, the entire damping material 2 undergoes tensile deformation following the panel member 1, and it is therefore thought that the accumulation of strain energy in the damping material 2 is low. Looking at Figure 3(a), which shows the distribution of strain energy accumulated in the damping material 2 of Figure 2(a), it can be seen that the strain energy accumulated in the damping material 2 is small, as there are few dark areas indicating areas with large strain energy.

[0047] On the other hand, as shown in Figure 2(b), in a structure in which the damping material 2 and the constraining layer 3 are laminated on the panel member 1, which is a schematic illustration of this embodiment, the constraining layer 3 constrains the damping material 2 so that it does not undergo tensile deformation in the first direction D1, thereby making it possible to generate shear deformation, i.e., large shear deformation, at both ends of the damping material 2. This makes it possible to accumulate large strain energy in the damping material 2. Looking at Figure 3(b), which shows the distribution of strain energy accumulated in the damping material 2 of Figure 2(b), we can see that there are many areas with darker colors indicating areas with large strain energy compared to Figure 3(a), and the color is particularly dark in part P, which indicates that a large amount of strain energy is accumulated in the damping material 2.

[0048] 1, the multiple convex rib portions 11 of the damping material 2 are continuous in a first direction D1, which is the direction in which the damping material 2 is tensilely deformed when a bending load B is input. Therefore, when the schematic cross-sectional views of the damping material 2 and the constraining layer 3 are viewed as in FIGS. 4(a) and 4(b), strain energy is not accumulated in the damping material 2 in the pre-vibration state of FIG. 4(a), but strain energy accumulates in the damping material 2 in the vibrating state of FIG. 4(b), with strain energy E being most accumulated in the corners 11a of the convex rib portions 11 and the corners 12a of the concave rib portions 12 of the damping material 2. Therefore, it can be seen that a damping structure in which the multiple convex rib portions 11 are constrained by the constraining layer 3 as shown in FIG. 1 has a high vibration damping effect.

[0049] Next, the vibration damping effect of the vibration damping structure of this embodiment will be verified with reference to FIGS.

[0050] Figure 5 shows examples of vibration-damping structures for investigating the vibration reduction effect, where I to III show structures having one to three layers of vibration-damping material 2 as the present embodiment and a constraining layer 3 fixed to the uppermost layer of vibration-damping material 2, and IV to VI show structures having only one to three layers of vibration-damping material 2 and no constraining layer 3 as comparative examples.

[0051] Fig. 6 is a diagram schematically illustrating a test specimen in which the damping material 2 corresponding to this example is applied vertically to a panel member 1. That is, in the vertically applied test specimen shown in Fig. 6, the damping material 2 is applied in a first direction D1, which is the direction in which the panel member 1 is tensile or compressive when a bending load is applied to the panel member 1, and multiple convex rib portions 11 are continuous in the first direction D1.

[0052] FIG. 7 is a graph showing the relationship between the frequency of the input vibration wave and the inertance (i.e., the ratio of the force and acceleration input to the object) when the vibration control structure in which the structures I to VI in FIG. 5 are applied to the test specimen in FIG. 6 as this embodiment and the structure X consisting only of the panel member 1 are vibrated.

[0053] Looking at the graph in Figure 7, when the vibration-damping material 2 is applied vertically to the panel member 1, both curves I to III, which show the inertance of the structure in this embodiment in which 1 to 3 layers of vibration-damping material 2 and constraining layer 3 are fixed, and curves IV to VI, which show the inertance of the structure in the comparative example in which only 1 to 3 layers of vibration-damping material 2 are used, have a greater effect in reducing the inertance peak than the inertance of structure X in which only the panel member 1 is used, and the peaks are more gentle.

[0054] Furthermore, in the graph of Figure 7, the peaks of curves I to III, which show the inertance of the structure having the damping material 2 of this embodiment together with the constraining layer 3, are clearly lower than the peaks of curves IV to VI, which show the inertance of the structure of the comparative example having only the damping material 2 without the constraining layer 3, and it can be seen that the constraining layer 3 greatly contributes to improving the vibration damping effect.

[0055] On the other hand, as a comparative example, we also verify the vibration damping effect of a structure in which the vibration-damping material 2 is applied horizontally to a panel member 1, as shown in Fig. 8. In this horizontally applied test specimen shown in Fig. 8, the vibration-damping material 2 is applied in a second direction D2 that is perpendicular to a first direction D1, which is the direction in which the panel member 1 is tensile or compressed when a bending load is input, and multiple convex rib portions 11 are continuous in the second direction D2.

[0056] FIG. 9 is a graph showing the relationship between the frequency of the input vibration wave and the inertance when a vibration control structure in which structures I to VI in FIG. 5 are applied to the test body in FIG. 8 as a comparative example, and a structure X consisting of only the panel member 1 are vibrated.

[0057] 9, when the damping material 2 is applied horizontally to the panel member 1, both curves I to III, which show the inertance of the structure of this example in which one to three layers of damping material 2 and constraining layer 3 are fixed, and curves IV to VI, which show the inertance of the comparative example structure with only one to three layers of damping material 2, are less effective at reducing the inertance peaks than the graph of this example in which the damping material 2 is applied vertically, as shown in Fig. 7, and the peaks are not very gentle. Also, in the graph of Fig. 9, the peaks of curves I to III, which show the inertance of the structure with constraining layer 3, are not nearly as low as the peaks of curves IV to VI, which show the inertance of the comparative example structure without constraining layer 3, indicating that the constraining layer 3 contributes little to vibration damping.

[0058] A comparison of the graphs in Figures 7 and 9 shows that the peaks of inertance for curves I to III in Figure 7 are significantly lower than the peaks for curves I to III in Figure 9, and therefore it can be seen that the test specimen in which the vibration-damping material 2 corresponding to this embodiment shown in Figure 6 is applied vertically to the panel member 1 has a higher vibration reduction effect than the test specimen in which the material is applied horizontally, which is the comparative example shown in Figure 8.

[0059] Here, with reference to Figure 10, we will further compare and consider the vibration damping effects of vertically applied damping material 2 and horizontally applied damping material 2. As shown in the schematic model in Figure 10, it can be seen that damping material 2 applied vertically along the first direction D1 with respect to the bending direction B1 has high bending rigidity and a high vibration damping effect. On the other hand, when considering a structure in which damping material 2 is applied horizontally with respect to the bending direction B2 (i.e., a structure in which damping material 2 is applied in the first direction D1 that is perpendicular to the second direction D2 along the bending direction B2), it can be seen that the bending rigidity of damping material 2 with respect to the bending direction B2 is low and the vibration damping effect is low.

[0060] (Application example of the vibration control structure of this embodiment) Next, application examples of the vibration damping structure of this embodiment will be described with reference to FIGS.

[0061] The vibration damping structure of this embodiment shown in Fig. 1 above can be used to damp vibrations in a floor panel 21 that constitutes the floor of a vehicle, as shown in Fig. 11. That is, the panel member 1 of Fig. 1 is applied to the floor panel 21 of Fig. 11. The vibration damping material 2 of Fig. 1 is applied to the upper surface of the floor panel 21 in the vehicle width direction Y as a first direction D1. Although not shown in Fig. 11, the vibration damping material 2 has a plurality of ridges 11 extending in the first direction D1, and a constraining layer 3 covers the top of the vibration damping material 2, as shown in Fig. 1.

[0062] As shown in FIG. 11, the lower part of the vehicle body 20 has a center frame 22 such as a floor tunnel extending in the vehicle fore-and-aft direction X at a middle position in the vehicle width direction Y, and a pair of side frames 23 such as side sills extending in the vehicle fore-and-aft direction X at both ends in the vehicle width direction Y.

[0063] 11 are fixed at both ends to a center frame 22 and a side frame 23 that extend in the vehicle front-rear direction X of the vehicle body. Note that it is sufficient that the floor panel 21 is fixed to at least one frame that extends in the front-rear direction. Furthermore, portions of the floor panel 21 other than the ends may be fixed to the frames.

[0064] The vibration-damping material 2 may be fixed to the floor panel 21 by being applied in a direction intersecting the vehicle longitudinal direction X, preferably extending in the vehicle width direction Y (first direction D1) perpendicular to the vehicle longitudinal direction X.

[0065] In addition, the multiple convex portions 11 (see Figure 1) of the vibration-damping material 2 may be arranged so as to be continuous in a direction that intersects the above-mentioned first direction D1 in which the vibration-damping material 2 is pulled or compressed when a bending load is input to the floor panel 21, which is fixed at both ends to the frames 22, 23, preferably in the vehicle width direction Y.

[0066] The vibration-damping material 2 shown in Fig. 11 extends in a vehicle width direction Y that is perpendicular to the vehicle longitudinal direction X and is fixed to a floor panel 21. The multiple convex stripes 11 shown in Fig. 1 are provided so as to be continuous in the vehicle width direction Y as a first direction D1.

[0067] The floor panel 21 is fixed to a plurality of cross members 24 that are spaced apart from each other in the vehicle longitudinal direction X and extend in the vehicle width direction Y in the vehicle body.

[0068] The floor panel 21 has a region 25 between the multiple cross members 24 in the floor panel 21 as a curved portion that curves downward.

[0069] The vibration-damping material 2 is fixed by coating or the like to at least a portion, and preferably the entire inner portion, of the curved region 25. This makes it possible to effectively damp vibrations in the downwardly curved region 25 of the floor panel 21, which has weak bending rigidity, by the vibration-damping material 2 constrained by the constraining layer 3 shown in Figure 1. The curved region may be a portion that is curved either upward or downward.

[0070] In order to provide more effective vibration damping, the vibration-damping material 2 extends in the vehicle width direction Y in the region 25 between the cross members 24, and it is preferable that the multiple convex strip portions 11 shown in Figure 1 are arranged so as to be continuous in the vehicle width direction Y as the first direction D1.

[0071] As shown in FIG. 11, the vibration-damping material 2 is preferably arranged in an area R below the seats on the floor panel 21, for example, in the area R where the driver's seat, passenger seat, and rear seats are located.

[0072] 12-13, the rear portion of the floor panel 21 is provided with spare tire pans 26, 28 for accommodating a spare tire, as another example of a curved portion that curves downward. The vibration-damping material 2 is fixed to at least a portion, preferably the entire inner portion, of the spare tire pans 26, 28, which are curved portions with low bending rigidity, thereby enabling vibration damping in the spare tire pans 26, 28. Although not shown in FIGS. 12-3, as shown in FIG. 1, the vibration-damping material 2 has a plurality of ridges 11 extending in the first direction D1, and the constraining layer 3 covers the top of the vibration-damping material 2. The curved portion may be a portion that curves either upward or downward.

[0073] The downwardly curved spare tire pans 26, 28 have particularly low bending rigidity in the centrifugal direction from the center of the spare tire pans 26, 28 toward the periphery. Therefore, the vibration-damping materials 2 shown in FIGS. 12-13 are fixed to the spare tire pans 26, 28 in a manner spaced apart from one another around the center so as to extend radially in the centrifugal direction (the same direction as the first direction D1 in FIGS. 12-14) from the center of the curved spare tire pans 26, 28 toward the periphery, when viewed from above, which is one side in the vertical direction. The multiple protruding ribs 11 are continuous in the centrifugal direction, which is the first direction D1. This makes it possible to achieve a high vibration-damping effect.

[0074] Here, when the spare tire pan 28 has an opening 27 in the center, as in the case of the spare tire pan 28 shown in Figure 13, multiple vibration-damping materials 2 can be made to extend radially from a ridge 29 formed around the opening 27, as shown in the enlarged view of Figure 14.

[0075] (Features of this embodiment)

[0076] (1) As shown in FIG. 1, the vibration damping structure of this embodiment includes a vibration damping material 2 fixed to an upper surface 1a of a panel member 1 by coating or the like, and a constraining layer 3 fixed to an upper surface 2c of the vibration damping material 2.

[0077] The damping material 2 has a plurality of convex rib portions 11 that are continuous along a first direction D1, which is the direction in which the damping material 2 is pulled or compressed when a bending load B is input to the panel member 1, and that are spaced apart from each other in a second direction D2 that is perpendicular to the first direction D1, and a plurality of concave rib portions 12 that are formed between two adjacent convex rib portions 11 of the plurality of convex rib portions 11. Therefore, the convex rib portions 11 increase the second moment of area of ​​the damping material 2, thereby improving the bending rigidity of the damping material 2.

[0078] Furthermore, the constraining layer 3 impregnated in the groove 12 of the damping material 2 constrains the two protrusions 11 on both sides of the groove 12, thereby further improving the bending rigidity of the damping material 2. Therefore, when a bending load B is input to the panel member 1, the amount of strain energy accumulated in the damping material 2 against the shear input generated in the damping material 2 fixed to the panel member 1 is improved, making it possible to improve the vibration reduction effect.

[0079] (2) In the vibration damping structure of this embodiment, as shown in Fig. 11, the panel member 1 is used in a floor panel 21 that constitutes the floor of a vehicle. Both end portions of the floor panel 21 are fixed to frames 22, 23 that extend in the vehicle longitudinal direction X of the vehicle body. The vibration damping material 2 extends in an intersecting direction that intersects with the vehicle longitudinal direction X and is fixed to the floor panel 21. The multiple protruding strip portions 11 are provided such that the intersecting direction is a first direction D1.

[0080] In this configuration, the panel member 1 is a floor panel 21 that constitutes the floor of the vehicle, and both ends of the floor panel 21 are fixed to frames 22, 23 that extend in the vehicle longitudinal direction X. Therefore, the bending rigidity of the floor panel 21 in the vehicle longitudinal direction X is increased by the reinforcing effect of the frames 22, 23.

[0081] On the other hand, the bending rigidity in the transverse direction intersecting the vehicle longitudinal direction X, particularly in the vehicle width direction Y, is weak because the reinforcing effect of frames 22, 23 is low. Therefore, floor panel 21 is most susceptible to bending deformation in the vehicle width direction Y when subjected to external vibrations.

[0082] Therefore, in this configuration, the damping material 2 extends in a direction intersecting the vehicle longitudinal direction X and is fixed to the floor panel 21, and the multiple convex ribs 11 are continuous in the intersecting direction. Furthermore, the constraining layer 3 constrains the spaces between the convex ribs 11 that are continuous in the intersecting direction. This increases the rigidity of the damping material 2, allowing strain energy to be accumulated in the damping material 2. As a result, it is possible to improve the vibration damping effect.

[0083] (3) In the vibration damping structure of this embodiment, the vibration damping material 2 extends in a vehicle width direction Y that is perpendicular to the vehicle longitudinal direction X and is fixed to the floor panel 21. The plurality of convex stripes 11 are provided with the vehicle width direction Y as a first direction D1.

[0084] In this configuration, the damping material 2 extends in the vehicle width direction Y, which is the direction in which the bending rigidity of the floor panel 21 is weakest, and the multiple protruding stripes 11 are continuous in the vehicle width direction Y, allowing more strain energy to be accumulated in the damping material 2. As a result, it is possible to further improve the vibration damping effect.

[0085] (4) In the vibration-damping structure of this embodiment, the floor panel 21 has downwardly curved spare tire pans 26, 28 shown in Figures 12 to 14 as an example of a curved portion curved downward or upward. The vibration-damping material 2 is fixed to the spare tire pans 26, 28.

[0086] When the floor panel 21 has curved portions such as spare tire pans 26, 28, the curved portions have weaker bending rigidity than other flat portions of the floor panel 21. In particular, the bending rigidity is extremely weak compared to the flat portions reinforced by the frames 22, 23. Therefore, with the above-described configuration, the vibration-damping material 2 is fixed to the curved portions (spare tire pans 26, 28) of the floor panel 21, which have weak bending rigidity. This allows strain energy to be stored in the vibration-damping material 2, whose rigidity has been increased by the constraining layer 3 restraining the ridge portions 11 as described above. As a result, it is possible to improve the vibration damping effect.

[0087] (5) 12 to 14, in the vibration-damping structure of this embodiment, the vibration-damping material 2 is fixed to the spare tire pans 26, 28 in a plurality of curved portions spaced apart from each other around the center so as to extend radially in a centrifugal direction (the same direction as the first direction D1 in FIGS. 12 to 14) from the center toward the periphery of the spare tire pans 26, 28 when viewed from one side in the vertical direction, for example, from above. The plurality of protruding ribs 11 are provided with the centrifugal direction as the first direction D1.

[0088] With this configuration, the bending rigidity in the direction from the center toward the periphery of the spare tire pans 26, 28 is particularly weak, so by configuring as described above, more strain energy can be accumulated in the vibration-damping material 2. As a result, it is possible to further improve the vibration damping effect.

[0089] (6) In the vibration-damping structure of this embodiment, the curved portions are spare tire pans 26, 28 that accommodate a spare tire. In this configuration, the spare tire pans 26, 28 are curved portions with a relatively large diameter that can accommodate a spare tire. The bending rigidity of such spare tire pans 26, 28 is particularly weak compared to the bending rigidity of other portions of the floor panel 21. Therefore, by affixing the vibration-damping material 2 to the spare tire pans 26, 28, strain energy can be accumulated in the vibration-damping material 2. As a result, the vibration-damping effect of the spare tire pans 26, 28 can be improved.

[0090] (7) In the vibration damping structure of this embodiment, the floor panel 21 is fixed to a plurality of cross members 24 that are spaced apart from each other in the vehicle longitudinal direction X and extend in the vehicle width direction Y in the vehicle body.

[0091] The curved portion is a portion of the area 25 between the multiple cross members 24 in the floor panel 21.

[0092] With this configuration, the bending rigidity of the curved portion of floor panel 21 in region 25 between multiple cross members 24 is particularly weak, and therefore, by fixing damping material 2 to this region 25, more strain energy can be accumulated in damping material 2. As a result, it is possible to improve the vibration damping effect in region 25 between cross members 24 of floor panel 21.

[0093] (8) In the vibration damping structure of this embodiment, the vibration damping material 2 extends in the vehicle width direction Y in the region 25 between the cross members 24. The multiple convex streak portions 11 are provided with the vehicle width direction Y as the first direction D1. With this configuration, the bending rigidity in the vehicle width direction Y is particularly weak in the region 25 between the cross members 24, so that the vibration damping material 2 extends in the vehicle width direction Y and is fixed to the region 25, and the multiple convex streak portions 11 of the vibration damping material 2 are continuous in the vehicle width direction Y, thereby allowing for even greater accumulation of strain energy in the vibration damping material 2. As a result, it is possible to further improve the vibration damping effect in the region 25 between the cross members 24.

[0094] (9) In the vibration-damping structure of this embodiment, the constraining layer 3 is made of a clear coating material, which makes it possible to realize the above-described vibration-damping structure using conventional vehicle manufacturing equipment that performs clear coating.

[0095] (10) In the vibration damping structure of this embodiment, the vibration damping material 2 is arranged in area R below the seat on the floor panel 21. According to this configuration, vibrations occurring in area R below the seat on the floor panel 21 are easily sensed by occupants, so by arranging the vibration damping material 2 in this area 25, vibrations of the floor panel 21 are less likely to be sensed by occupants, improving comfort.

[0096] (11) In the vibration-damping structure of this embodiment, the constraining layer 3 entirely covers the multiple ridge portions 11 and groove portions 12 of the vibration-damping material 2. This allows the multiple ridge portions 11 to be tightly and integrally constrained by the constraining layer 3. This further improves the bending rigidity of the vibration-damping material 2. This further improves the amount of strain energy stored in the vibration-damping material 2, making it possible to further improve the vibration reduction effect. [Explanation of symbols]

[0097] 1 Panel member 2 Damping material 3 restraint layer 11 Convex portion 12 Concave section 21 Floor Panel 22 Center Frame 23 Side frame 24 Cross member 25 Area (Curved Shape) 26, 28 Spare tire pan (curved section) D1 1st direction D2 2nd direction

Claims

1. A panel member; a vibration-damping material fixed to at least one surface of the panel member; a constraint layer that is less likely to deform than the vibration-damping material and is fixed to the surface of the vibration-damping material opposite to the panel member; Equipped with The vibration-damping material is a plurality of convex ridges each extending continuously along a first direction, which is a direction in which the vibration-damping material is pulled or compressed when a bending load is input to the panel member, and spaced apart from each other in a second direction perpendicular to the first direction; a plurality of recessed portions formed between adjacent two of the plurality of protruding portions; and The constraining layer is impregnated in the groove portion. A vibration-damping structure characterized by:

2. 2. The vibration damping structure according to claim 1, the panel member is a floor panel that constitutes a floor of a vehicle, The floor panel is fixed to a frame of the vehicle body that extends in the vehicle front-rear direction, The vibration-damping material extends in a direction intersecting the vehicle front-rear direction and is fixed to the floor panel, The plurality of convex stripes are provided with the intersecting direction as a first direction. A vibration-damping structure characterized by:

3. 3. The vibration damping structure according to claim 2, The vibration-damping material extends in a vehicle width direction perpendicular to the vehicle front-rear direction and is fixed to the floor panel, The plurality of convex stripes are provided with the vehicle width direction as a first direction. A vibration-damping structure characterized by:

4. The vibration damping structure according to claim 1, the panel member is a floor panel that constitutes a floor of a vehicle, The floor panel has a curved portion that is curved downward or upward, The vibration-damping material is fixed to the curved portion. A vibration-damping structure characterized by:

5. The vibration damping structure according to claim 4, the vibration-damping materials are fixed to the curved portion at intervals around the center of the curved portion so as to extend radially from the center in a centrifugal direction when viewed from one side in the up-down direction, The plurality of convex ridge portions are provided with the centrifugal direction as the first direction. A vibration-damping structure characterized by:

6. The vibration damping structure according to claim 4, The curved portion is a spare tire pan that accommodates a spare tire. A vibration-damping structure characterized by:

7. The vibration damping structure according to claim 4, The floor panel is fixed to a plurality of cross members in the vehicle body that are spaced apart from each other in the vehicle longitudinal direction and extend in the vehicle width direction, The curved portion is a portion of the floor panel in a region between the plurality of cross members. A vibration-damping structure characterized by:

8. The vibration damping structure according to claim 7, The vibration-damping material extends in the vehicle width direction in the region between the cross members, The plurality of convex stripes are provided with the vehicle width direction as a first direction. A vibration-damping structure characterized by:

9. The vibration damping structure according to claim 1 or 2, The constraint layer is made of a clear coating material. A vibration-damping structure characterized by:

10. The vibration damping structure according to claim 1 or 2, The vibration-damping material is disposed in a region below the seat in the floor panel. A vibration-damping structure characterized by:

11. The vibration damping structure according to claim 1 or 2, The constraining layer entirely covers the plurality of ridges and grooves of the vibration-damping material. A vibration-damping structure characterized by:

Images