Vibration-damping members, roof liners, vehicle ceiling structures and vibration-damping structures

Abstract

To provide new vibration damping techniques.SOLUTION: A vibration damping member comprises a foam body which has an average modulus of elasticity of 40 kPa or more and 200 kPa or less under compressive strains ranging from 0 to 3%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vibration damping member. [Background technology]

[0002] Various techniques have been proposed to suppress vibrations (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 10-203267 (Paragraph

[0010] etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] New vibration control technologies are needed. [Means for solving the problem]

[0005] A first aspect of the invention is a vibration-damping member made of a foam having an average elastic modulus of 40 kPa or more and 200 kPa or less in a compression strain range of 0 to 3%. [Brief explanation of the drawings]

[0006] [Figure 1] (A) An upper perspective view of a vibration-damping member attached to a vehicle, (B) a rear cross-sectional view of a roof liner equipped with a vibration-damping member. [Figure 2] Side cross-sectional view of ceiling structure [Figure 3] Exploded perspective view of a vehicle ceiling structure [Figure 4] Cross-sectional view of the test equipment for vibration damping tests [Figure 5] Cross-sectional view of the vibration-damping material and roof liner in the vibration-damping test [Figure 6] (A) A table showing the characteristics of the vibration damping members of the examples and comparative examples, (B) stress-strain curves of the vibration damping members of Example 1 and Comparative Examples 1 and 2, [Figure 7] Stress-strain curves of vibration damping members of Examples and Comparative Examples up to a compressive strain of 3% [Figure 8] (A) Graph showing the resonance frequency and vibration transmissibility of Examples and Comparative Examples, (B) Graph showing the resonance frequency and vibration transmissibility of Examples and Comparative Examples using polyurethane resin foam vibration damping members DETAILED DESCRIPTION OF THE INVENTION

[0007] A vibration-damping member 10 according to one embodiment of the present disclosure is applied to another member to reduce vibration of that member, and is made of foam. FIG. 1(A) shows an example of use of the vibration-damping member 10. In this example, the vibration-damping member 10 is applied to a body panel of a vehicle 90 to dampen vibrations of the body panel. Specifically, the vibration-damping member 10 is provided in a ceiling structure 100 of the vehicle 90 (see FIGS. 1(B) and 2). The ceiling structure 100 includes a roof panel 91 as a body panel, and a roof liner 20 as an interior ceiling material that is layered on 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 liner.

[0008] 2 and 3, a reinforcement 80 may be provided between the roof panel 91 and the roof liner 20. In this case, for example, the vibration-damping member 10 is disposed at a position that avoids the reinforcement 80. In this embodiment, the vibration-damping member 10 is sheet-shaped and extends in the vehicle width direction (left-right direction), with multiple members placed on the roof liner 20 in the front-rear direction (see FIGS. 1(A) and 2).

[0009] The reinforcement 80 is applied to and fixed to the roof panel 91 (see FIG. 2) to reinforce the roof panel 91. For example, as shown in FIG. 3, the reinforcement 80 is provided with a pair of side rail reinforcements 80S that are overlapped on the side edges of the roof panel 91, and is also provided with a cross beam 81 that extends across the side rail reinforcements 80S in the vehicle width direction. The cross beam 81 is applied to the underside of the roof panel 91 (see FIG. 2). In this embodiment, the vibration damping member 10 is disposed between the pair of side rail reinforcements 80S in the vehicle width direction, and is also disposed between the cross beams 81 in the front-rear direction.

[0010] The roof liner 20 is penetrated by components such as an assist grip, a rearview mirror, and a room light that are attached to the roof panel 91, and is fixed to the vehicle body panel by these components. In this case, for example, the vibration damping member 10 is disposed in a position that avoids these components.

[0011] 3, for example, the side edges of a roof panel 91 are supported by pillars of a vehicle 90. In such a configuration, it is thought that the central portion of the roof panel 91 in the vehicle width direction is more susceptible to vibration than the side edges. For this reason, it is preferable that the vibration damping member 10 abuts against at least the central portion of the roof panel 91 in the vehicle width direction.

[0012] The vibration-damping member 10 may be fixed (for example, glued) to the upper surface of the roof liner 20. The vibration-damping member 10 may be fixed to the roof liner 20 during the assembly process to the vehicle 90, or a roof liner 30 with a vibration-damping member (see FIG. 3 ) in which the vibration-damping member 10 is fixed to the upper surface of the roof liner 20 may be formed in advance.

[0013] In this embodiment, for example, the roof liner 20 is formed by molding (for example, by hot press molding) a laminated sheet in which multiple sheets are stacked together into a shape that conforms to the roof panel 91. For example, as shown in Fig. 5, this laminated sheet may have a configuration in which a foamed sheet 21 is sandwiched between a pair of fiber sheets 22 (for example, glass fiber sheets), and these are further sandwiched from the outside by a pair of face materials 23, 24. In this configuration, the face materials 23, 24 are formed, for example, from a resin sheet, a nonwoven fabric, or the like.

[0014] In this embodiment, the foam constituting the vibration-damping member 10 is breathable and has an open-cell structure or a semi-open-cell structure. By making the vibration-damping member 10 out of a breathable foam, it is possible to provide the vibration-damping member 10 with sound-absorbing properties. The cell membrane (so-called mirror) between the foam cells can be removed, for example, by a combustion gas blast or hydrolysis with an alkali, but it is preferable to leave it in place. The presence of the cell membrane makes it possible to improve the vibration-damping properties of the foam compared to when the cell membrane is not present. The foam constituting the vibration-damping member 10 may be non-breathable or may have a closed-cell structure.

[0015] In this embodiment, the foam constituting the vibration-damping member 10 is a polyurethane resin foam, but is not limited to this and may be, for example, a polyolefin resin foam such as a polyethylene resin or a polypropylene resin, or a phenolic resin foam. In this embodiment, the vibration-damping member 10 is made of slab urethane and is, for example, cut into a sheet.

[0016] The apparent density of the vibration-damping member 10 is, for example, 40 kg / m from the viewpoint of weight reduction. 3 By reducing the weight of the vibration damping member 10 in this way, for example, when the vibration damping member 10 is mounted on a vehicle such as a car 90, it is possible to improve the fuel efficiency and electricity consumption of the vehicle.

[0017] As described above, the vibration-damping member 10 of this embodiment is made of a foam and can be applied to a vibrating member by, for example, being sandwiched between two other members to damp the vibration of the member. However, further improvements in the vibration-damping properties of such a vibration-damping member are desirable. Therefore, the present inventors have carefully examined the relationship between vibration-damping properties and foam characteristics. As a result of extensive research, they have discovered a configuration that can further improve vibration-damping properties by focusing on the elastic modulus of the foam, and have thus invented the vibration-damping member 10 of the present disclosure.

[0018] Specifically, the vibration-damping member 10 has an average modulus of elasticity of 40 kPa or more and 200 kPa or less in the range of compressive strain of 0 to 3% (the range in which compressive strain is 0 or more and 0.03 or less). This makes it possible to achieve a significant improvement in vibration-damping properties, as will be described later. Here, the average modulus of elasticity in the range of compressive strain of 0 to 3% is determined as the slope of an approximation line in the range of strain of 0% or more and 3% or less, relative to the stress-strain curve when the vibration-damping member 10 is compressively deformed. The approximation line and its slope are calculated by the least squares method and can be obtained, for example, using the spreadsheet software "Microsoft Excel" (manufactured by Microsoft Corporation).

[0019] For example, the vibration-damping member 10 may be sandwiched between two members such as a roof panel 91 and a roof liner 20 so that the compressive strain is within a predetermined range. For example, this range may be a range from a compressive strain of 0% to a compressive strain equal to or less than the proportional limit in a stress-strain curve (for example, a range of compressive strain of 0 to 3%). The range of compressive strain equal to or less than the proportional limit (the limit at which stress increases linearly with an increase in strain) may be, for example, a range of compressive strain equal to or less than the proportional limit (the limit at which stress increases linearly with an increase in strain) in which the coefficient of determination R 2 A range where (the square of the correlation coefficient) is 0.95 or more may be adopted.

[0020] In the ceiling structure 100 of this embodiment, for example, the vibration-damping members 10 extend in the vehicle width direction, and multiple members are placed on the roof liner 20 in the front-rear direction, abutting at least the central portion of the roof panel 91 in the vehicle width direction. By dividing the vibration-damping members 10 into multiple members, it is possible to arrange the vibration-damping members 10 with thicknesses appropriate to the spacing between the roof panel 91 and the roof liner 20, for example, when the spacing between the roof panel 91 and the roof liner 20 varies depending on the location, thereby widening the contact area between the underside of the roof panel 91 and the vibration-damping members 10. Furthermore, as described above, in a configuration in which the side edges of the roof panel 91 are supported by pillars, it is considered that the central portion of the roof panel 91 in the vehicle width direction is likely to vibrate. In contrast, the vibration-damping members 10 of this embodiment abut at least the central portion of the roof panel 91 in the vehicle width direction, making it easier to damp vibrations in that central portion. It is also possible to configure the vibration-damping members 10 so that they do not abut the central portion of the roof panel in the vehicle width direction.

[0021] The roof liner 20 may be configured such that the vibration-damping member 10 is fixed to the upper surface. In this way, it is possible to provide the roof liner with the function of reducing vibration of the roof panel 91. Furthermore, with this configuration, simply by attaching the roof liner 20 to the vehicle 90, the vibration-damping member 10 is also attached to the vehicle 90, making it possible to easily attach the vibration-damping member 10.

[0022] In the above, the roof panel 91 and the roof liner 20 are shown as examples of the body panel and interior material that sandwich the vibration-damping member 10 in the vehicle 90, but this is not limited to this, and for example, the vibration-damping member 10 may be sandwiched between a body panel other than the roof panel 91 and an interior material, and used to damp the vibration of that body panel.

[0023] The vibration-damping member 10 may also be disposed in vehicles other than automobiles, such as in buildings. For example, a vibration-damping structure may be provided in which the vibration-damping member 10 is sandwiched between two members, and at least one of the members that is assigned to the vibration-damping member 10 may be damped. [Example]

[0024] The above-described embodiment will be described in more detail below with reference to examples and comparative examples, but the vibration damping member of the present disclosure is not limited to the following examples.

[0025] 1. Structure of the vibration damping members of the examples and comparative examples Sheet-shaped vibration-damping members were prepared for Examples 1 to 5 and Comparative Examples 1 to 7 shown in Fig. 6(A). Each vibration-damping member was made of a different material.

[0026] Example 1 The vibration-damping member 10 of Example 1 is a polyurethane resin foam having a thickness of 20 mm and an apparent density of 16.7 kg / m 3 The hardness (based on JIS K6400-2 D method, same below) is 59N. The tensile strength is 91kPa and the elongation is 257%.

[0027] <Example 2> The vibration damping member 10 of Example 2 is a polyurethane resin foam having a thickness of 20 mm and an apparent density of 11.9 kg / m 3 , hardness is 52N. Tensile strength is 47kPa, elongation is 30%.

[0028] Example 3 The vibration damping member 10 of Example 3 is a polyurethane resin foam having a thickness of 20 mm and an apparent density of 34.7 kg / m 3 The hardness is 147N. The tensile strength is 131kPa and the elongation is 176%.

[0029] Example 4 The vibration damping member 10 of Example 4 is a polyurethane resin foam having a thickness of 20 mm and an apparent density of 23.7 kg / m 3 The hardness is 128N. The tensile strength is 135kPa and the elongation is 168%.

[0030] <Example 5> The vibration damping member 10 of Example 5 is a polyurethane resin foam having a thickness of 20 mm and an apparent density of 150.5 kg / m3 , tensile strength is 198kPa and elongation is 295%.

[0031] <Comparative Example 1> The vibration damping member of Comparative Example 1 is a felt made of polyethylene terephthalate resin fiber and has a thickness of 30 mm.

[0032] <Comparative Example 2> The vibration damping member of Comparative Example 2 is Thinsulate TF2300 (manufactured by 3M) and has a thickness of 27 mm.

[0033] <Comparative Examples 3 to 5> The vibration-damping members of Comparative Examples 3 to 5 are polyurethane resin foams, and have a thickness of 20 mm. As will be described later, the vibration-damping members of Comparative Examples 3 to 5 have a higher average elastic modulus in the range of compressive strain of 0 to 3% than the vibration-damping members of Examples 1 to 5. In Comparative Example 3, the apparent density was 28.2 kg / m 3 In Comparative Example 4, the apparent density was 32.2 kg / m 3 In Comparative Example 5, the apparent density was 16.9 kg / m 3 , tensile strength 106kPa, elongation 48%.

[0034] <Comparative Examples 6 and 7> The vibration-damping members of Comparative Examples 6 and 7 were polyurethane resin foams, and had a thickness of 20 mm. As will be described later, the vibration-damping members of Comparative Examples 6 and 7 had a lower average elastic modulus in the range of compressive strain of 0 to 3% than the vibration-damping members of Examples 1 to 5. In Comparative Example 6, the apparent density was 21.7 kg / m 3 In Comparative Example 7, the apparent density was 29.4 kg / m 3 , hardness 66N, tensile strength 38kPa, elongation 131%.

[0035] <Comparative Example 8> Comparative Example 8 is a blank without a vibration damping member.

[0036] 2. Evaluation The vibration damping properties of the examples and comparative examples were evaluated. The methods for measuring the various properties of the examples and comparative examples are as follows.

[0037] <Measurement method> (1) Apparent density The density of the vibration-damping member was measured in accordance with JIS K7222.

[0038] (2) Hardness The hardness of the vibration-damping member was measured in accordance with JIS K6400-2 D method.

[0039] (3) Average elastic modulus The vibration-damping members of Examples 1 to 5 and Comparative Examples 1 to 7 were compressed at 23°C using an Autograph AG-X / R (Shimadzu Corporation), and the average elastic modulus was determined in the range of compressive strain of 0 to 3%. The vibration-damping members measured 100 mm × 100 mm × 20 mm (thickness). A pressure tool (a circular pressing surface with a diameter of 50 mm) was applied to the center of the planar shape of the vibration-damping member, and the vibration-damping member was compressed at a speed of 50 mm / min until the compressive strain of the vibration-damping member reached 75% (until the thickness reached 25% of the original thickness), thereby obtaining a stress-strain curve. Furthermore, an approximation line for the stress-strain curve in the range of compressive strain between 0% and 3% was obtained using the spreadsheet software "Microsoft Excel" (Microsoft Corporation), and the slope of the approximation line was calculated (the y-axis intercept was not fixed). The stress data for the stress-strain curve was plotted every 0.01 seconds from the start of compression until the strain reached 3%.

[0040] (4) Vibration damping The vibration-damping properties of each example and each comparative example were compared. The test fixture for evaluating vibration-damping properties is shown in FIG. 4 . This test fixture fixes the vibration-damping member 10 to a steel plate 91A serving as a roof panel 91, applies vibration to the steel plate 91A, and evaluates the vibration-damping properties of the vibration-damping member 10. Specifically, this test fixture includes a frame 60 that fixes the outer edge of the steel plate 91A. The frame 60 includes an upper frame 61 and a lower frame 62 that are screwed together while sandwiching the outer edge of the steel plate 91A from above and below, and also includes a base 63 that supports the lower frame 62 from below. The base 63 has a plate-shaped bottom 64 with sidewalls 65 extending upward from the outer edge of the bottom 64, and the lower frame 62 is fixed to the upper end of the sidewalls 65 (for example, formed integrally with the lower frame 62). The frame 60 is supported at its four corners by springs suspended from supports (not shown). An acceleration sensor 67 is attached to the center of the lower surface of the steel plate 91A. The frequency of the vibration of the spring is much lower than the frequency of the resonance peak, which will be described later.

[0041] The vibration-damping members of each example and comparative example (vibration-damping members 10 of Examples 1 to 4 are shown in FIG. 4) are placed on the steel plate 91A, and then the roof liner 20 is placed on top of them. The planar size of the vibration-damping members is 500 mm x 400 mm. The steel plate 91A is 600 mm x 500 mm x 0.8 mm (thickness), and the roof liner 20 is 500 mm x 400 mm x 6.5 mm (thickness) with a basis weight of 580 g / m 2 The steel plate 91A, the vibration-damping member, and the roof liner 20 are arranged so that their longitudinal directions are the same.

[0042] The roof liner 20 is made of laminated sheets, and as shown in FIG. 5, has a configuration in which a foam sheet 21 is sandwiched between a pair of glass fiber sheets, which are then sandwiched from the outside by a pair of face materials 23, 24. These sheets are laminated together by hot press molding and bonded with a thermosetting binder. In this test, the steel plate 91A (roof panel), vibration damping member, and roof liner 20 are arranged upside down from when they are installed in the vehicle 90. In other words, the face material 24, which is arranged at the top in this test, is arranged at the bottom (toward the passenger compartment) when the roof liner 20 is installed in the vehicle.

[0043] Then, as described above, with the steel plate 91A fixed to the frame portion 60, the central portion of the bottom portion 64 of the base portion 63 is struck from below with the impulse hammer 68, thereby vibrating the steel plate 91A through the frame portion 60. Note that the vibration of the frame portion 60 when the bottom portion 64 is struck with the impulse hammer 68 is negligible compared to the vibration of the steel plate 91A.

[0044] The impulse hammer 68 and the acceleration sensor 67 are connected to an FFT analyzer. The vibration transmissibility [dB] for each frequency is obtained from the excitation force of the impulse hammer 68 and the detection result of the acceleration sensor 67 (see FIGS. 8(A) and 8(B)). Of the obtained resonance peaks, the vibration transmissibility (height of the resonance peaks) of four resonance peaks (approximately 160 Hz, approximately 220 Hz, approximately 240 Hz, and approximately 370 Hz; the peaks indicated by arrows in FIG. 8(B)) found in the vicinity of 125 to 400 Hz, which are considered to have a particularly large contribution to road noise, were evaluated.

[0045] The vibration damping was evaluated as ◯ when the average value of the vibration transmissibility at the above four peaks was 16 dB or less, and x when it exceeded 16 dB. The lower the vibration transmissibility, the better the vibration damping.

[0046] (5) Tensile strength and elongation The tensile strength and elongation of the vibration-damping member were measured in accordance with JIS K6400-5.

[0047] <Evaluation results> As shown in Figure 6(A), it was confirmed that Examples 1 to 5 had significantly improved vibration-damping properties (evaluation of vibration-damping properties was ◯) compared to Comparative Examples 1 and 2, in which the vibration-damping member was made of a nonwoven fabric, and Comparative Example 8, which was a blank without a vibration-damping member. It was also confirmed that, among the vibration-damping members made of polyurethane resin foam, the vibration-damping members of Examples 1 to 5 were able to exhibit superior vibration-damping properties compared to the vibration-damping members of Comparative Examples 3 to 7. Here, the vibration-damping members of Examples 1 to 5 had a lower average modulus of elasticity in the range of 0 to 3% compressive strain compared to the vibration-damping members of Comparative Examples 3 to 5 (evaluation of vibration-damping properties was ×), while the average modulus of elasticity was higher compared to the vibration-damping members of Comparative Examples 6 and 7 (evaluation of vibration-damping properties was ×). Specifically, as shown in Figures 6(A) and 7, the average elastic modulus (slope of the approximate straight line) of the vibration-damping member is 40 kPa or more and 200 kPa or less in Examples 1 to 5, but exceeds 200 kPa in Comparative Examples 3 to 5, and is lower than 40 kPa in Comparative Examples 6 and 7.

[0048] In Examples 1 to 5, the compressive strain corresponding to the proportional limit in the stress-strain curve is 3% (0.03) or more (i.e., the stress increases linearly with an increase in strain of at least 3%. For example, see FIG. 6(B)). In addition, in the vibration-damping test, the basis weight of the roof liner 20 placed on the vibration-damping member was 580 g / m2 as described above. 2 (equivalent to approximately 5.7 Pa), however, as can be seen from FIG. 7, in the vibration-damping members of Examples 1 to 5 and Comparative Examples 3 to 7, the stress corresponding to a compressive strain of 1% (0.01) is approximately 780 Pa (Comparative Example 6) or more, and therefore it is believed that these vibration-damping members were hardly compressed in this test.

[0049] As described above, it was confirmed that Examples 1 to 5, which were foams and had an average elastic modulus of 40 kPa or more and 200 kPa or less at a compression strain of 0 to 3%, were able to exhibit particularly excellent vibration-damping properties. 3or less, which is particularly preferable from the viewpoint of weight reduction. Here, from the results of Example 5, it is considered that vibration-damping members with a high apparent density generally tend to have better vibration-damping properties. In contrast to this, it can be seen that the vibration-damping members of Examples 1 and 2, for example, have particularly excellent vibration-damping properties, even compared to the vibration-damping members of Comparative Examples 3 to 5, which have the same or higher apparent densities. In this way, it has been confirmed that a vibration-damping member with an average elastic modulus of 40 kPa or more and 200 kPa or less exhibits an excellent effect that could not be predicted from the conventional state of the art, in that the vibration-damping properties are particularly good, even compared to vibration-damping members with the same or higher apparent densities.

[0050] <Additional Notes> The following describes the features extracted from the above-described embodiments and examples, highlighting their effects as necessary.

[0051] For example, the following group of features can be considered to have been conceived in response to the problem that "new vibration control technology is required" in relation to the background technology that "various technologies for suppressing vibration have been proposed (for example, JP 10-203267 A (paragraph

[0010] , etc.)") regarding vibration control members.

[0052] [Feature 1] A vibration-damping member made of a foam having an average elastic modulus of 40 kPa or more and 200 kPa or less in the range of compressive strain of 0 to 3%.

[0053] A vibration-damping member having this characteristic can improve vibration-damping properties.The average elastic modulus of the vibration-damping member in the range of compressive strain of 0 to 3% is more preferably 50 kPa or more and 180 kPa or less.

[0054] [Feature 2] Apparent density: 40 kg / m 3 A vibration damping member according to feature 1, which is as follows:

[0055] According to this feature, it is possible to reduce the weight of the vibration-damping member. For example, when the vibration-damping member is mounted on a vehicle, it is possible to improve the fuel efficiency and electric power efficiency of the vehicle.

[0056] [Feature 3] 3. The vibration-damping member according to Feature 1 or 2, having a hardness of 40 N or more in accordance with JIS K6400-2 D method.

[0057] [Feature 4] Apparent density is 10 kg / m 3 The vibration damping member according to any one of the above features 1 to 3.

[0058] [Feature 5] A roof liner for a vehicle having a vibration-damping member according to any one of features 1 to 4 fixed to its upper surface.

[0059] This feature allows the roof liner to have the function of reducing vibrations of the roof panel. Also, this feature makes it possible to easily install the vibration-damping member since simply installing the roof liner on the vehicle also installs the vibration-damping member on the vehicle.

[0060] [Feature 6] A vehicle ceiling structure in which the vibration-damping member according to any one of features 1 to 4 is sandwiched between a roof liner and a roof panel.

[0061] According to this feature, vibration of the roof panel can be reduced.

[0062] [Feature 7] The vehicle ceiling structure described in Feature 6, wherein the vibration-damping members extend in the vehicle width direction, are placed on the roof liner in the front-to-rear direction, and abut at least the center of the roof panel in the vehicle width direction.

[0063] In this feature, because the vibration-damping member is divided into multiple pieces, it is possible to arrange a vibration-damping member of a thickness appropriate to the gap between the roof panel and the roof liner, for example, when the gap varies depending on the location, and it is possible to widen the contact area between the underside of the roof panel and the vibration-damping member. Furthermore, since the side edges of a vehicle's roof panel are supported by pillars, it is thought that the central portion in the vehicle width direction is prone to vibration. In contrast, in this feature, the vibration-damping member abuts at least the central portion in the vehicle width direction of the roof panel, making it easier to damp vibrations in that central portion.

[0064] [Feature 8] A vibration-damping structure in which the vibration-damping member according to any one of features 1 to 4 is sandwiched between members.

[0065] According to this feature, it is possible to damp vibrations of the member to which the damping member is applied.

[0066] [Feature 9] A vibration-damping member according to any one of Features 1 to 4; a member to which the vibration-damping member is applied.

[0067] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone. [Explanation of symbols]

[0068] 10. Vibration-damping member 20 Roof liner 90 vehicles 91 Roof panel 100 Ceiling structure

Claims

1. A vibration-damping member made of a slab urethane foam having an average elastic modulus of 40 kPa or more and 200 kPa or less in a compression strain range of 0 to 3%, A vibration-damping member characterized in that the average elastic modulus is a value calculated as the slope of an approximate straight line obtained for the range of compressive strain of 0 to 3%, based on a stress-strain curve obtained by compressing the vibration-damping member at a speed of 50 mm / min until the compressive strain becomes 75%.

2. Apparent density: 40 kg / m ３ 2. The vibration damping member according to claim 1, wherein:

3. A roof liner for a vehicle having the vibration damping member according to claim 1 or 2 fixed to an upper surface thereof.

4. A ceiling structure for a vehicle, wherein the vibration-damping member according to claim 1 or 2 is sandwiched between a roof liner and a roof panel.

5. 5. The vehicle ceiling structure according to claim 4, wherein the vibration-damping members extend in the vehicle width direction, are placed on the roof liner in the front-rear direction, and are in contact with at least a central portion of the roof panel in the vehicle width direction.

6. A vibration-damping structure in which the vibration-damping member according to claim 1 or 2 is sandwiched between members.

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