Vibration damping member, roof liner, vehicle structure, ceiling structure, and vibration damping structure

Abstract

The present invention seeks for a novel vibration damping technique. This vibration-damping member has a first outer surface on which a plurality of protrusions are arranged, and is provided with a foam body having an average elastic modulus of 3 kPa to 27 kPa (inclusive) at a compressive strain in the range of 0-30%.

Description

Technical Field

[0001] The invention relates to a vibration-damping component. Background Art

[0002] Various techniques have been proposed to suppress vibration (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 10-203267 (paragraph 0010 etc.) Summary of the invention

[0006] Problems to be solved by the invention

[0007] Seeking new vibration reduction technology.

[0008] Solutions to Solve Problems

[0009] A first aspect of the invention is a vibration damping member having a first outer surface having a plurality of protrusions arranged thereon, and comprising a foam having an average elastic modulus of 3 kPa to 27 kPa in a range of a compressive strain of 0 to 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] exist Figure 1 middle, Figure 1 A is a perspective view of a vibration-damping member installed in a vehicle. Figure 1 B is a rear cross-sectional view of the roof lining provided with the vibration damping member.

[0011] Figure 2 It is a side sectional view of the ceiling structure.

[0012] Figure 3 It is an exploded perspective view of the roof structure of the vehicle.

[0013] Figure 4 It is a three-dimensional diagram of the vibration-damping component.

[0014] Figure 5 This is a plan view of the vibration-damping component.

[0015] exist Figure 6 middle, Figure 6 A is the AA line cross-sectional view of the vibration-damping component. Figure 6 B is a cross-sectional view of the vibration damping member taken along line BB.

[0016] exist Figure 7 middle, Figure 7 A is the CC line cross-sectional view of the vibration-damping component. Figure 7 B is a sectional view of the vibration damping member taken along line DD.

[0017] Figure 8 It is a side view of a processing line feeding a sheet to be contoured.

[0018] Fig. 9 It is a side view of the processing line when the sheet is contoured.

[0019] Fig.10 It is a cross-sectional view of a test apparatus for a vibration damping test.

[0020] Fig.11 It is a cross-sectional view of a vibration damping member and a headliner in a vibration damping test.

[0021] exist Fig.12 middle, Fig.12 A is a table showing the characteristics of the vibration damping members of the embodiment and the comparative example, Fig.12 B is a graph showing stress-strain curves of the vibration damping members of Example 1 and Comparative Examples 1 and 2.

[0022] Fig.13 It is a graph showing stress-strain curves of the vibration damping members of the examples and comparative examples until the compressive strain reaches 30%.

[0023] exist Fig.14 middle, Fig.14 A is a graph showing the resonant frequency and vibration transmissibility of the embodiment and the comparative example, Fig.14 B is a graph showing the resonance frequency and vibration transmissibility of the vibration damping member of the example and the comparative example using the polyurethane resin foam.

[0024] exist Fig.15 middle, Fig.15 A is a cross-sectional view of the vibration reduction component, steel plate and sound insulation layer in the transmission loss test. Fig.15 B is a graph showing the transmission loss of Example 1 and Comparative Examples 4 and 5. DETAILED DESCRIPTION

[0025] The vibration damping member 10 according to one embodiment of the present invention is closely attached to another member to reduce the vibration of the member, and is made of a foam. Figure 1 A shows an example of using the vibration damping member 10. In this example, the vibration damping member 10 is installed in a roof structure 100 of a vehicle 90 (see Figure 1 B and Figure 2 The ceiling structure 100 includes a roof panel 91 as a vehicle body panel and a roof lining 20 as an interior material of the ceiling that overlaps the roof panel 91 from below. In the ceiling structure 100, the vibration-damping member 10 is sandwiched between the roof panel 91 and the roof lining 20 to damp vibration of the roof panel 91.

[0026] like Figure 2 as well as Figure 3 As shown in FIG. 1 , a reinforcement member 80 may be provided between the top plate 91 and the headliner 20. In this case, for example, the vibration damping member 10 is provided at a position away from the reinforcement member 80. In the example of the present embodiment, the vibration damping member 10 is in the form of a sheet, extends in the vehicle width direction (left-right direction), and is provided in a plurality of sheets in the front-rear direction of the headliner 20 (see FIG. 1 ). Figure 1 A and Figure 2 ).

[0027] It should be noted that the reinforcement member 80 is closely attached to and fixed to the top plate 91 (see Figure 2 ), the top plate 91 is strengthened. For example, Figure 3 As shown in FIG. 1 , a pair of side beam reinforcements 80S overlapping the side edge portions of the top plate 91 are provided in the reinforcement member 80, and a cross beam 81 is provided which is mounted on the pair of side beam reinforcements 80S and extends in the vehicle width direction. The cross beam 81 is closely attached to the lower surface of the top plate 91 (see FIG. 1 ). Figure 2 In the example of the present embodiment, the vibration damping member 10 is disposed between the pair of side member reinforcements 80S in the vehicle width direction and between the cross members 81 in the front-rear direction.

[0028] The roof lining 20 is penetrated by components such as an auxiliary handle, a room mirror, and a room lamp mounted on the roof panel 91 and fixed to the vehicle body panel by these components. In this case, for example, the vibration damping member 10 is arranged at a position avoiding these components.

[0029] like Figure 3 As shown, for example, in the top plate 91, the side edge portions are supported by the pillars of the vehicle 90. In such a structure, it is considered that the center portion in the vehicle width direction of the top plate 91 is more likely to vibrate than the side edge portions thereof. Therefore, the vibration damping member 10 is preferably in contact with at least the center portion in the vehicle width direction of the top plate 91.

[0030] The vibration damping member 10 may also be fixed (for example, bonded) to the upper surface of the roof lining 20. It should be noted that the vibration damping member 10 may be fixed to the roof lining 20 during the assembly process to the vehicle 90, or a roof lining 30 with a vibration damping member in which the vibration damping member 10 is fixed to the upper surface of the roof lining 20 may be formed in advance (see Figure 3 ).

[0031] In the present embodiment, for example, the headliner 20 is formed by forming (for example, hot press forming) a laminated sheet obtained by laminating a plurality of sheets into a shape along the top plate 91. For example, Fig.11As shown, the laminated sheet can be structured as follows: a pair of fiber sheets 22 (e.g., glass fiber sheets) are used to clamp the foam sheet 21, and further clamp them from the outside using a pair of face materials 23, 24. In this structure, for example, the face materials 23, 24 are composed of resin sheets or nonwoven fabrics.

[0032] In the example of the present embodiment, the foam constituting the vibration-damping component 10 is air-permeable and has a continuous bubble structure or a semi-continuous bubble structure. Since the vibration-damping component 10 is composed of an air-permeable foam, the vibration-damping component 10 can be made sound-absorbing. It should be noted that the pore membrane (so-called mirror surface) between the foam cells of the foam can be removed by, for example, the explosion wave of the combustion gas, alkali-based hydrolysis, etc., but it is preferably not removed and remains. Due to the presence of the pore membrane, the vibration-damping property of the foam can be improved compared to the case where the pore membrane does not exist. It should be noted that the foam constituting the vibration-damping component 10 can also be a non-air-permeable structure, or an independent bubble structure.

[0033] In the present embodiment, the foamed body constituting the vibration-damping member 10 is a foamed body of a polyurethane resin, but is not limited thereto, and for example, it may be a foamed body of a polyolefin resin such as a polyethylene resin or a polypropylene resin, or a foamed body of a phenolic resin. In the example of the present embodiment, the vibration-damping member 10 is composed of a slab polyurethane, for example, cut into sheets.

[0034] The apparent density of the vibration damping member 10 is preferably 40 kg / m 3 As described below, by reducing the weight of the vibration damping member 10, when the vibration damping member 10 is mounted on a vehicle such as the vehicle 90, for example, the fuel consumption or power consumption of the vehicle can be reduced.

[0035] As described above, the vibration damping member 10 of the present embodiment includes a foam body, and is closely attached to the vibrating member by being sandwiched between two members, for example (see Figure 1 B and Figure 2 ), vibration reduction of the component can be achieved. Here, the interval between the vehicle body panel such as the top plate 91 and the interior material such as the roof lining 20 is usually not uniform due to the shape of the vehicle body panel and the interior material, or the deviation of the forming. Therefore, for example, at a position where the interval is narrow, there will be a problem that the vibration reduction component 10 is clamped strongly and the rebound force of the vibration reduction component 10 becomes too strong. As a result, for example, in the example of the present embodiment, when the roof lining 20 is assembled to the top plate 91, due to the rebound force of the vibration reduction component 10, the roof lining 20 is pushed back to the lower side (so-called large assembly load), and the fixing of the roof lining 20 by components such as the auxiliary handle or the interior mirror and the interior lamp sometimes becomes difficult.

[0036] In this regard, in the vibration-damping component 10 of the present embodiment, the surface in close contact with other components becomes a concave-convex surface with a plurality of protrusions 14 arranged thereon. Thus, compared with a vibration-damping component with a uniform thickness, it is possible to suppress the situation where the rebound force of the vibration-damping component 10 sandwiched between components becomes too strong (the compression load becomes too high). Specifically, in the vibration-damping component 10 of the present embodiment, the first surface 11 on one side of the front and back surfaces becomes the above-mentioned concave-convex surface. It should be noted that, in the present embodiment, the second surface 12 on the opposite side of the first surface 11 on the front and back surfaces of the vibration-damping component 10 becomes a flat surface.

[0037] like Figure 4 As shown, in the example of this embodiment, a plurality of protrusions 14 are arranged two-dimensionally within the entire range of the first surface 11. For example, the concave-convex pattern including the plurality of protrusions 14 on the first surface 11 is repeated two-dimensionally in a constant pattern, and the plurality of protrusions 14 are arranged in a lattice at a constant interval (see Figure 5 In the example of the present embodiment, the plurality of protrusions 14 are arranged in a staggered manner. For example, the vibration damping member 10 is formed into a rectangular sheet when viewed from above, and a row of a plurality of protrusions 14 arranged at a constant pitch in the long side direction of the vibration damping member 10 is arranged so as to be staggered by half the pitch in the long side direction relative to a row of a plurality of protrusions 14 adjacent to the row in the short side direction of the vibration damping member 10 (see Figure 5 as well as Figure 6 ). In addition, in the longitudinal direction and the lateral direction of the vibration damping member 10, a valley bottom 15 closest to the second surface 12 in the first surface 11 is provided between the protrusions 14 (see Figure 6 A and Figure 6 B), for example, the top of the protrusion 14 and the valley bottom 15 are repeated at a constant interval, and the valley bottom 15 is also arranged in a staggered manner. In addition, in the example of this embodiment, the concave-convex pattern of the first surface 11 is symmetrical in the long side direction and the short side direction of the vibration damping member 10. It should be noted that Figure 6 A is a cross-sectional view of the vibration damping member 10 at a section (AA section) passing through the tops and valley bottoms 15 of the protrusions 14 alternately arranged in the longitudinal direction. Figure 6 B is a cross-sectional view of the vibration damping member 10 at a cross section (BB cross section) passing through the tops and valley bottoms 15 of the protrusions 14 alternately arranged in the short-side direction. Figure 7 A is a cross-sectional view of the vibration damping member 10 at a cross section (CC cross section) passing through the top of the protrusion 14 connected in a direction inclined (for example, a direction inclined at 45 degrees) with respect to the above-mentioned long side direction and short side direction. Figure 7 B is a cross-sectional view of the vibration damping member 10 at a cross section (DD cross section) passing through the valley bottoms 15 arranged in the above-mentioned inclined direction. In the example of the present embodiment, the shapes and dimensions of the protrusions 14 are the same.

[0038] In the example of this embodiment, Figure 6 as well as Figure 7 As shown, the protrusion 14 is formed into a shape whose cross-sectional area decreases as it approaches its protruding front end (for example, a mountain shape), and the first surface 11 is formed into a curved surface that is wavy when viewed in cross section. The protrusion 14 is formed into a shape whose slope gradually increases from its base end side to the midway position P as it approaches the protruding front end, and whose slope gradually decreases as it approaches the protruding front end from the midway position P (that is, the midway position P becomes an inflection point). The protruding front end of the protrusion 14 has rounded corners. It should be noted that, for example, the valley bottom 15 is arranged at approximately the center in the thickness direction of the vibration damping member 10 (that is, as shown in FIG. 1 ). Figure 6 as well as Figure 7 As shown, the distance L1 from the protruding front end of the protrusion 14 to the valley bottom 15 is substantially the same as the distance L2 from the valley bottom 15 to the second surface 12).

[0039] In the present embodiment, the first surface 11 (i.e., the plurality of protrusions 14) of the vibration damping member 10 is in close contact with the top plate 91 (i.e., the first surface 11 faces upward). In the vibration damping member 10 of the present embodiment, when the vibration damping member 10 is pressed against the top plate 91 (especially when it is compressed to a height less than the protrusion height of the protrusion 14, etc.), it is possible to suppress the rebound force of the vibration damping member 10 from becoming too strong when compressed, compared with a vibration damping member having a constant thickness. In addition, since the protrusion 14 is formed in a shape in which the cross-sectional area decreases toward the protruding front end, when the compression amount of the protrusion 14 is small, the rebound force of the vibration damping member 10 can be further reduced, thereby making it easier to fix the vibration damping member 10.

[0040] In the example of the present embodiment, the first surface 11 is a contoured surface formed by contour processing. Therefore, the concavo-convex pattern of the first surface 11 can be easily formed.

[0041] However, it is also desired to further improve the vibration damping performance of a vibration damping component having a foam body. Therefore, the inventors of the present application conducted a detailed investigation on the relationship between the vibration damping performance and the characteristics of the foam body. Furthermore, as a result of the in-depth study, by focusing on the elastic modulus of the foam body, they obtained insights into the structure that can further improve the vibration damping performance, thereby inventing the vibration damping component 10 of the present invention.

[0042] Specifically, in the vibration damping member 10, the average elastic modulus in the range of 0 to 30% of the compressive strain (the range of the compressive strain being greater than 0 and less than 0.3) is greater than 3 kPa and less than 27 kPa. As a result, as described later, a significant improvement in vibration damping performance can be achieved. Here, the average elastic modulus in the range of 0 to 30% of the compressive strain is obtained as the slope of an approximate straight line in the range of 0% to 30% relative to a stress-strain curve when the vibration damping member 10 is compressively deformed. The approximate straight line and its slope are calculated by the least squares method, for example, and can be obtained using the spreadsheet software "Microsoft Excel" (manufactured by Microsoft Corporation).

[0043] It should be noted that, for example, the vibration damping member 10 can be used by being sandwiched between two members such as the top plate 91 and the roof lining 20 in a manner that is within a specified range of compressive strain. For example, as this range, a range in which the concave-convex pattern of the first surface 11 is not completely destroyed can be adopted (in the example of the present embodiment, it is greater than 0% and less than 50%). And, as this range, in the stress-strain curve, a range from a compressive strain of 0% to a compressive strain below the proportional limit (for example, a range of 0 to 30% of compressive strain) can also be adopted. It should be noted that as a range of compressive strain below the proportional limit, for example, a range in which the determination coefficient R2 (square of the correlation coefficient) of the approximate straight line of the stress-strain curve is greater than 0.95 can also be adopted.

[0044] As described above, in the example of the present embodiment, the vibration damping member 10 is arranged so that the first surface 11 faces upward, and the first surface 11 is in close contact with the top plate 91 (see Figure 1 B and Figure 2 ). By making the first surface 11 provided with a plurality of protrusions 14 close to the top plate 91 in this way, it is easy to compress the vibration damping member 10 according to the shape of the lower surface of the top plate 91 (it is easy to make it follow the shape of the lower surface of the top plate 91). For example, for the purpose of improving strength, a rib processing portion extending in the front-to-back direction is sometimes provided on the top plate 91. The rib processing portion forms a protrusion or a recess on the lower surface of the top plate 91, so that the lower surface of the top plate 91 is formed into a concave-convex shape. With such a structure, in the vibration damping member 10 of the present embodiment, it is also possible to make it easy to follow the shape of the lower surface of the top plate 91. It should be noted that in the example of the present embodiment, the surface of the vibration damping member 10 that is in close contact with the vehicle body panel (top plate 91) is the first surface 11, but it can also be the second surface 12.

[0045] The roof lining 20 may also be configured to fix the vibration damping member 10 to the upper surface. In this way, the roof lining can have the function of reducing the vibration of the roof plate 91. In addition, according to this configuration, the vibration damping member 10 is also mounted on the vehicle 90 simply by mounting the roof lining 20 on the vehicle 90, so that the vibration damping member 10 can be easily mounted.

[0046] It should be noted that, in the ceiling structure 100 of the present embodiment, for example, the vibration damping member 10 extends in the vehicle width direction, and a plurality of vibration damping members 10 are placed in the front-rear direction of the roof lining 20, and abut against at least the center portion of the roof panel 91 in the vehicle width direction. In this way, the vibration damping member 10 is divided into a plurality of vibration damping members, and when the interval between the roof panel 91 and the roof lining 20 varies depending on the location, the vibration damping member 10 having a thickness corresponding to the interval can be arranged, so that the contact portion between the lower surface of the roof panel 91 and the vibration damping member 10 can be expanded. In the case where a plurality of vibration damping members 10 are provided in this way, the first surface 11 of some of the vibration damping members 10 may be in close contact with the roof panel 91, and the first surface 11 of the remaining vibration damping members 10 may be in close contact with the roof lining 20. In addition, in the configuration in which the side edge portion of the roof panel 91 is supported by the pillar as described above, it is considered that the center portion of the roof panel 91 in the vehicle width direction is easy to vibrate. In contrast, the vibration damping member 10 of the present embodiment contacts at least the center portion of the roof panel 91 in the vehicle width direction, so vibration of the center portion can be easily damped. It should be noted that the vibration damping member 10 may not contact the center portion of the roof panel in the vehicle width direction.

[0047] It should be noted that the vibration damping member 10 in which the first surface 11 is a contoured surface can be manufactured, for example, as follows. Figure 8 As shown, a sheet 10A of slab polyurethane is fed between a pair of rollers 41 of a processing line 40. The sheet 10A is clamped by the pair of rollers 41 and fed while being elastically compressed, and is sliced ​​by a cutter 42 between the pair of rollers 41. Here, the pair of rollers 41 have a plurality of peripheral protrusions 43 arranged at a predetermined interval on the outer peripheral surface, and are arranged opposite to each other in such a manner that the peripheral protrusions 43 of each other are staggered. Therefore, the portion of the sheet 10A that has passed between the pair of rollers 41 that is sunk into the peripheral protrusion 43 of one roller 41 from one side of the front and back does not dock with the peripheral protrusion 43 of the other roller 41 from the other side of the front and back, and becomes a portion that is not sunk into the peripheral protrusion 43, so that the sheet 10A is elastically compressed asymmetrically in the thickness direction. Therefore, the sheet 10A is separated from the state of being sandwiched by the pair of rollers 41 toward the downstream side in the feeding direction, and when the sheet 10A is elastically restored in a manner that the front and back surfaces become flat, the sliced ​​surface of the sheet 10A changes from a flat surface to a curved surface with projections and depressions, thereby forming the first surface 11. In this way, two vibration-damping members 10 are obtained. It should be noted that the sheet 10A is cut into a predetermined plane size before or after slicing.

[0048] In this way, by forming the first surface 11 by contour processing, two vibration damping members 10 can be formed at one time, and the vibration damping member 10 can be easily formed. It should be noted that in the configuration in which the valley bottom 15 is arranged substantially at the center in the thickness direction of the vibration damping member 10, the thickness of the sheet 10A before contour processing is approximately 1.5 times that of the vibration damping member 10.

[0049] [Other embodiments]

[0050] In the above-mentioned embodiment, the vibration damping member 10 is provided in the ceiling structure 100 of the vehicle 90, but the present invention is not limited thereto, and the vibration damping member 10 can also be used in a vehicle structure in which the first surface 11 is in close contact with at least one of the vehicle body panel and the interior material. In addition, the vibration damping member 10 is not limited to being provided in a vehicle structure, and the vibration damping member 10 can be provided in a vibration damping structure in which the first surface 11 is in close contact with a vibrating member, or in a vibration damping structure in which the vibration damping member 10 is sandwiched between members and the first surface 11 is in close contact with at least one of the members.

[0051] The vibration-damping member 10 may be disposed in a vehicle other than a motor vehicle, and may also be disposed in a building, for example. For example, a vibration-damping structure in which the vibration-damping member 10 is sandwiched between two members may be provided to damp vibration of at least one of the two members that is in close contact with the vibration-damping member 10 (for example, a concave-convex surface having a plurality of protrusions 14).

[0052] The shape of the concavo-convex surface having the protrusion 14 in the vibration damping member 10 is not limited to the above-mentioned embodiment, and the protrusion 14 may be hemispherical, cone-shaped, such as a cone or a pyramid, truncated cone-shaped, such as a truncated cone-shaped, truncated cone-shaped, or column-shaped, such as a cylindrical or prism-shaped. In addition, the protrusion 14 may be, for example, a protrusion extending in the long side direction or the short side direction of the vibration damping member 10, and the first surface 11 may be a concavo-convex surface formed by arranging a plurality of such protrusions in approximately parallel. Such a protrusion may have a triangular cross-section or a semicircular cross-section.

[0053] In the above embodiment, all the protrusions 14 have the same shape, but some of the protrusions 14 may have a shape different from the remaining protrusions 14. The shapes or arrangements of the protrusions 14 may be random.

[0054] In the above-described embodiment, the second surface 12 may be a concave-convex surface having a plurality of protrusions 14 .

[0055] The vibration damping member 10 may be formed into a laminated structure. For example, the vibration damping member 10 may be a laminated structure in which another sheet is laminated on the second surface 12 (for example, a flat surface) of the foam in the above embodiment.

[0056] The concavoconvex surface including the plurality of protrusions 14 of the vibration damping member 10 may be a concavoconvex surface (laser processed surface) obtained by laser processing instead of a contour processed surface. In addition, the foamed body of the vibration damping member 10 may be a molded product formed with a concavoconvex surface including the plurality of protrusions 14 by foaming in a mold, or may be a stamped product formed with a concavoconvex surface by stamping a foamed sheet.

[0057] The vibration damping member 10 is in the form of a sheet in the above embodiment, but it may also be in the form of a block such as a rectangular parallelepiped. In this case, the concave-convex surface (e.g., a surface having a plurality of protrusions 14) may be included in at least one surface of the vibration damping member 10. In this case, for example, by bringing the surface into close contact with a vibrating member, the vibration of the member can be suppressed.

[0058] [Example]

[0059] Hereinafter, the above-mentioned embodiment will be described in more detail by way of examples and comparative examples, but the vibration damping member of the present invention is not limited to the following examples.

[0060] 1. Structure of vibration damping member of Example and Comparative Example

[0061] As Figure 6 The vibration damping members of Examples 1 to 6 and Comparative Examples 1 to 4 shown in A were prepared in the form of sheets. The vibration damping members were made of different materials.

[0062] <Examples 1 to 6>

[0063] The vibration damping members 10 of Examples 1 to 6 are foamed polyurethane resins, which are slab polyurethanes. In the vibration damping members 10 of Examples 1 to 6, the first surface 11 is Figures 4 to 7 The second surface 12 is a flat surface. Figure 6 ) is located at the center of the thickness (30 mm) of the vibration damping member 10 (ie, the distance L1 is the same as the distance L2). The distance between the tops of the protrusions 14 (the distance between the valley bottoms 15) in the long and short directions of the vibration damping member 10 is 31 mm.

[0064] <Comparative Example 1>

[0065] The vibration damping member of Comparative Example 1 is a felt of polyethylene terephthalate resin fibers.

[0066] <Comparative Example 2>

[0067] In Comparative Example 2, the vibration damping member was Thinsulate TF2300 (manufactured by 3M Co.).

[0068] <Comparative Example 3>

[0069] The vibration damping member of Comparative Example 3 is a foam of polyurethane resin, i.e., a slab polyurethane. As described below, the vibration damping member of Comparative Example 3 has a higher average elastic modulus in the range of 0 to 30% of compressive strain than the vibration damping members of Examples 1 to 6.

[0070] <Comparative Example 4>

[0071] In the vibration damping member of Comparative Example 4, first surface 11 is a flat surface (that is, both the front and back surfaces are flat surfaces). The other structures are the same as those of vibration damping member 10 of Example 1.

[0072] <Comparative Example 5>

[0073] Comparative Example 5 is a body without a vibration damping member.

[0074] 2. Evaluation

[0075] The vibration damping properties of the embodiments and comparative examples (see Fig.12 A) Evaluation was performed. The measuring methods of the various properties of Examples and Comparative Examples are as follows.

[0076] <Measurement method>

[0077] (1) Apparent density

[0078] The density of the vibration damping member is measured in accordance with JIS K7222.

[0079] (2) Hardness

[0080] The hardness of the vibration damping member was measured in accordance with JIS K6400-2 D method.

[0081] (3) Average elastic modulus

[0082] The vibration-damping components of Examples 1 to 6 and Comparative Examples 1 to 3 were compressed at 23°C using Autograph AG-X / R (manufactured by Shimadzu Corporation) to obtain the average elastic modulus in the range of 0 to 30% compression strain. The size of the vibration-damping component is 100 mm×100 mm×30 mm (thickness). In addition, a pressure member with a diameter of 200 mm was placed in close contact with the entire surface of one of the front and back surfaces of the vibration-damping component (the entire surface of the first surface 11 in Examples 1 to 6), and compressed at a speed of 50 mm / mmin until the compression strain of the vibration-damping component was 75% (the thickness became 25% of the original), thereby obtaining a stress-strain curve. In addition, the spreadsheet software "Microsoft Excel" (manufactured by Microsoft Corporation) was used to obtain an approximate straight line in the range of 0% to 30% of the compression strain relative to the stress-strain curve, and the slope of the approximate straight line was calculated (the y-axis intercept was not fixed). It should be noted that the stress data of the above stress-strain curve were plotted every 0.01 seconds from the start of pressurization until the strain reached 30%.

[0083] (4) Vibration reduction

[0084] The vibration damping properties of the embodiments and comparative examples were compared. Fig.10 . In the test device, the vibration-damping member 10 is fixed on the steel plate 91A as the top plate 91, and the steel plate 91A is given vibration, and the vibration-damping property brought by the vibration-damping member 10 is evaluated. Specifically, the test device includes a frame portion 60 that fixes the outer edge of the steel plate 91A. The frame portion 60 includes an upper frame 61 and a lower frame 62 that are screwed in a state of clamping the outer edge of the steel plate 91A from top to bottom, and includes a base portion 63 that supports the lower frame 62 from the bottom. The base portion 63 is provided with a side wall portion 65 that stands up from the outer edge of the plate-shaped bottom 64 to the upper side, and the lower frame 62 is fixed to the upper end of the side wall portion 65 (for example, formed as a whole with the lower frame 62). In addition, the frame portion 60 is suspended from the four corners of the spring support of the support portion not shown in the figure. An acceleration sensor 67 is installed in the central part of the lower surface of the steel plate 91A. It should be noted that the frequency of the vibration of the above-mentioned spring is much lower than the frequency of the resonance peak described later.

[0085] The vibration damping members of each embodiment and each comparative example are placed on the steel plate 91A. Fig.10The vibration-damping member 10 of Examples 1 to 6 is shown in FIG. ), and a roof lining 20 is placed from above. In Examples 1 to 6, the first surface 11 is arranged to face upward (i.e., toward the side of the roof lining 20). The plane size of the vibration-damping member is 500 mm×400 mm. The steel plate 91A has a size of 600 mm×500 mm×0.8 mm (thickness), the roof lining 20 has a size of 500 mm×400 mm×6.5 mm (thickness), and the unit area weight is 580 g / m 2 The steel plate 91A, the vibration damping member, and the roof lining 20 are arranged so that their longitudinal directions are the same.

[0086] It should be noted that the roof lining 20 is composed of laminated sheets, such as Fig.11 As shown, it has a structure in which a foam sheet 2 is clamped by a pair of glass fiber sheets and further clamped from the outside by a pair of face materials 23 and 24. The above-mentioned sheets are stacked and integrated by hot pressing and bonded by a thermosetting adhesive. It should be noted that in this test, the overlapping order of the steel plate 91A (top plate), the vibration-damping member, and the roof lining 20 is reversed when it is set in the vehicle 90. That is, when the roof lining 20 is arranged in the vehicle, the face material 24 arranged on the uppermost side in this test is arranged on the lowermost side (the vehicle compartment side).

[0087] As described above, in a state where the steel plate 91A is fixed to the frame portion 60, the center portion of the bottom portion 64 of the base portion 63 is struck from below by the hammer 68, thereby imparting vibration to the steel plate 91A through the frame portion 60. It should be noted that the vibration of the frame portion 60 when the bottom portion 64 is struck by the hammer 68 is negligible compared to the vibration of the steel plate 91A.

[0088] The impact hammer 68 and the acceleration sensor 67 are connected to the FFT analyzer. And, the vibration transmission rate [dB] of each frequency is obtained based on the vibration force of the impact hammer 68 and the detection result of the acceleration sensor 67 (refer to Fig.14 A and Fig.14 B) Among the obtained resonance peaks, four resonance peaks (about 160 Hz, about 220 Hz, about 240 Hz, and about 370 Hz) were observed near 125 to 400 Hz, which are particularly conducive to road noise. Fig.14 The peak indicated by the arrow in B) was used to evaluate the vibration transmissibility (the height of the resonance peak).

[0089] The vibration damping property was evaluated as ○ when the average value of the vibration transmissibility of the four peaks was 22 dB or less, and evaluated as × when the average value of the vibration transmissibility of the four peaks exceeded 22 dB. It should be noted that the lower the vibration transmissibility, the better the vibration damping property.

[0090] (5) Transmission loss

[0091] The transmission loss of Example 1 and Comparative Examples 4 and 5 was measured in accordance with JIS A1441-1:2007. Fig.15 As shown in FIG. 1A, in Example 1 and Comparative Example 4, the vibration damping member is sandwiched between a steel plate 91A (thickness 0.8 mm) and a sound insulation layer 96, and sound is incident from the steel plate 91A side. As the sound insulation layer 96, a PVB (polyvinyl butyral) plate (weight per unit area 3600 g / m 2 ). In Example 1, measurements were performed for an example in which the first surface 11 of the vibration damping member 10 was directed toward the steel plate 91A side and an example in which the first surface 11 of the vibration damping member 10 was directed toward the sound insulation layer 96 side. In Comparative Example 5, measurements were performed using only the steel plate 91A. It should be noted that the plane dimensions of the vibration damping member, the steel plate 91A, and the sound insulation layer 96 are 500 mm×500 mm.

[0092] (6) Tensile strength and elongation

[0093] The tensile strength and elongation of the vibration damping member were measured in accordance with JIS K6400-5.

[0094] <Evaluation Results>

[0095] like Fig.12 As shown in B, it can be seen that in Example 1 having a plurality of protrusions 14 on the first surface 11, the stress can be reduced relative to the same strain compared to Comparative Example 4 in which the first surface 11 is flat. In particular, in the range of strain of 0 to 30%, the stress can be greatly reduced relative to the same strain. For example, in Comparative Example 4, the range (proportional limit) in which the stress increases linearly relative to the strain is up to a strain of about 3% (0.03), while in Example 1, the range (proportional limit) in which the stress increases linearly relative to the strain is a strain of 30% (0.3) or more.

[0096] like Fig.12 As shown in A, in Examples 1 to 6, it can be confirmed that the vibration damping property is greatly improved (the vibration damping property is evaluated as ○) compared with Comparative Examples 1 and 2 in which the vibration damping member is composed of a non-woven fabric and Comparative Example 5 in which there is no vibration damping member. In addition, in the vibration damping member composed of a foamed body of a polyurethane resin, it can be confirmed that the vibration damping member of Examples 1 to 6 can exhibit excellent vibration damping property compared with the vibration damping member of Comparative Example 3. Here, in the vibration damping members of Examples 1 to 6, the average elastic modulus in the range of compression strain of 0 to 30% is lower than that of the vibration damping member of Comparative Example 3 (the vibration damping property is evaluated as ×), and on the other hand, the above average elastic modulus is higher than that of the vibration damping members of Comparative Examples 1 and 2 (the vibration damping property is evaluated as ×). Specifically, as Fig.12 A and Fig.13As shown, in Examples 1 to 6, the average elastic modulus (slope of the approximate straight line) of the vibration damping member is 3 kPa or more and 27 kPa or less, in Comparative Example 3, the average elastic modulus of the vibration damping member exceeds 27 kPa, and in Comparative Examples 1 and 2, the average elastic modulus of the vibration damping member is less than 3 kPa. In Examples 1 to 6, in the stress-strain curve, the compressive strain corresponding to the proportional limit is 30% (0.3) or more (for example, refer to Fig.12 B) It should be noted that, in addition to Example 1 in which the spacing between the tops of the protrusions 41 of the first surface 11 was 31 mm, tests were also conducted on examples in which the spacing was 16 mm and the average elastic modulus was calculated, and it was confirmed that there was almost no difference in the average elastic modulus caused by the difference in the spacing.

[0097] As described above, it can be confirmed that Examples 1 to 6, which are foams and have an average elastic modulus of 3 kPa or more and 27 kPa or less with a compression strain of 0 to 30%, can exhibit particularly excellent vibration damping properties. 3 The following is particularly preferred from the viewpoint of lightweighting. Here, generally speaking, in a vibration-damping component having a higher apparent density, it is believed that there is a tendency for the vibration-damping property to be better. In this regard, for example, in the vibration-damping component of Example 6, it can be seen that the vibration-damping property is particularly excellent compared with the vibration-damping component of Comparative Example 3 having an apparent density equal to or higher than that. In this way, according to the vibration-damping component having an average elastic modulus of 3 kPa or more and 27 kPa or less, it can be confirmed that the vibration-damping property is particularly good compared with the vibration-damping component having an apparent density equal to or higher than that, which is an excellent effect that cannot be predicted based on the existing technical level.

[0098] In addition, if Fig.15 As shown in FIG. 1B, in the vibration damping member 10 of Example 1 having a contoured surface, it can be confirmed that the transmission loss can be increased compared with the vibration damping member of Comparative Example 5 of the blank or Comparative Example 4 without a contoured surface. In particular, the transmission loss of 4 to 5 dB at the maximum is increased at 1000 Hz to 3150 Hz, which greatly contributes to the clarity of conversation in the vehicle interior (ease of hearing speech). It should be noted that it can be confirmed that the contoured surface (first surface) in Example 1 is equally good regardless of the orientation.

[0099] <Notes>

[0100] Hereinafter, the feature groups extracted from the above-mentioned embodiments and examples will be described while showing effects etc. as needed. It should be noted that, in order to facilitate understanding, the corresponding configurations in the above-mentioned embodiments are appropriately shown using brackets etc., but these feature groups are not limited to the specific configurations shown by the brackets etc.

[0101] For example, the following feature group can be considered to be a result of the subject of "seeking a new vibration reduction technology" in response to the background art that "various technologies have been proposed to suppress vibration (for example, Japanese Patent Application Laid-Open No. 10-203267 (paragraph 0010, etc.)" regarding vibration reduction components.

[0102] [Feature 1]

[0103] A vibration-damping component, wherein:

[0104] The vibration-damping member has a first outer surface (11) on which a plurality of protrusions are arranged.

[0105] The vibration damping member includes a foam having an average elastic modulus of 3 kPa or more and 27 kPa or less in a range of a compressive strain of 0 to 30%.

[0106] According to the vibration-damping component of this feature, the vibration-damping property can be improved. In addition, for example, when the vibration-damping component is sandwiched between components, by making the first outer surface having a plurality of protrusions closely attached to at least one of the components, it is possible to prevent the rebound force of the foam from becoming too strong, thereby preventing the vibration-damping component from being difficult to fix.

[0107] [Feature 2]

[0108] In the vibration damping member according to feature 1, the first outer surface is a contoured surface.

[0109] According to this feature, the concavo-convex pattern of the first outer surface can be easily formed, and the first outer surfaces of the pair of vibration damping members can be formed at one time.

[0110] [Feature 3]

[0111] The vibration damping member according to feature 1 or 2, wherein the apparent density is 40 kg / m 3 the following.

[0112] According to this feature, the vibration damping member can be made lighter. For example, when the vibration damping member is mounted on a vehicle, the fuel consumption or power consumption of the vehicle can be reduced.

[0113] [Feature 4]

[0114] In the vibration damping member according to any one of Features 1 to 3, the plurality of protrusions are two-dimensionally arranged on the first outer surface.

[0115] [Feature 5]

[0116] In the vibration damping member according to any one of features 1 to 4, the plurality of protrusions are arranged so as to be repeated in a constant pattern on the first outer surface.

[0117] [Feature 6]

[0118] In the vibration damping member according to any one of features 1 to 5, the protrusion is formed in a shape whose cross-sectional area decreases toward a protruding front end thereof.

[0119] [Feature 7]

[0120] A roof lining for a vehicle includes the vibration damping member according to any one of Features 1 to 6 on its upper surface and has the first outer surface facing upward.

[0121] According to this feature, the roof lining can have the function of reducing the vibration of the roof panel. In addition, according to this feature, the vibration damping member is also installed on the vehicle by simply installing the roof lining on the vehicle, so the vibration damping member can be easily installed.

[0122] [Feature 8]

[0123] A vehicle structure, wherein the vibration damping member described in any one of features 1 to 6 is sandwiched between a vehicle body panel and an interior material, and the first outer surface is in close contact with at least one of the vehicle body panel and the interior material.

[0124] [Feature 9]

[0125] A vehicle ceiling structure, wherein the vibration damping member described in any one of features 1 to 6 is sandwiched between a roof lining and a roof panel, and the first outer surface is in close contact with at least one of the roof lining and the roof panel.

[0126] According to this feature, the vibration of the top plate can be reduced.

[0127] [Feature 10]

[0128] A vibration damping structure, wherein the vibration damping component described in any one of features 1 to 6 is sandwiched between components, and the first outer surface is in close contact with at least one of the components.

[0129] [Feature 11]

[0130] A vibration reduction structure, wherein:

[0131] The vibration damping structure includes: the vibration damping member described in any one of features 1 to 6, and a member with which the first outer surface of the vibration damping member is in close contact.

[0132] According to features 10 and 11, it is possible to achieve vibration reduction of a member to which the vibration reduction member is in close contact.

[0133] It should be noted that, while specific examples of the technology included in the technical solution are disclosed in this specification and the accompanying drawings, the technology recorded in the technical solution is not limited to these specific examples, but also includes various deformation and alteration methods of the specific examples, and also includes methods of taking out a part from the specific example separately.

[0134] Description of Reference Numerals

[0135] 10 vibration-damping member; 11 first surface; 14 protrusion; 20 roof lining; 90 vehicle; 91 roof panel; 100 roof structure.

Claims

1. A vibration-damping component, wherein: The vibration damping member comprises a foam body, The foam body has a first outer surface on which a plurality of protrusions are arranged, The average elastic modulus of the foamed body within a range of a compressive strain of 0 to 30% is 3 kPa or more and 27 kPa or less.

2. The vibration-damping member according to claim 1, wherein: The first outer surface is a contoured surface.

3. The vibration damping member according to claim 1 or 2, wherein: The apparent density is 40kg / m 3 the following.

4. A roof lining for a vehicle, wherein: The vehicle roof lining includes the vibration damping member according to claim 1 or 2 on an upper surface, and has the first outer surface facing upward.

5. A vehicle structure, in, The vibration damping member according to claim 1 or 2 is sandwiched between a vehicle body panel and an interior material, and the first outer surface is in close contact with at least one of the vehicle body panel and the interior material.

6. A roof structure of a vehicle, in, The vibration damping member according to claim 1 or 2 is sandwiched between a roof lining and a roof panel, and the first outer surface is in close contact with at least one of the roof lining and the roof panel.

7. A vibration reduction structure, wherein: The vibration damping member according to claim 1 or 2 is sandwiched between members, and the first outer surface is in close contact with at least one of the members.

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