Vibration damper for floor panel and vibration control method

Abstract

The present invention aims to provide a vibration damping function for a conventional bottom plate member. The vibration damper for the floor according to the present invention is a vibration damper for a floor having a polyurethane foam layer.

Description

Technical Field

[0001] The present invention relates to a vibration damping member for a base plate and a vibration control method. Background Art

[0002] Conventionally, various floor panels have been developed (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 9-95169 (Paragraph 0006, Figure 1 wait) Summary of the invention

[0006] Problems to be solved by the invention

[0007] Aiming at improving the vibration reduction function of the existing bottom plate.

[0008] Solutions to Solve Problems

[0009] A first aspect of the invention is a vibration damping member for a floor having a polyurethane foam layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] exist Figure 1 middle, Figure 1 A is a side view of a floor vibration damping member provided in a vehicle. Figure 1 B is a side sectional view of the floor vibration damping member placed on the floor panel.

[0011] exist Figure 2 middle, Figure 2 A is a cross-sectional view of a mold for injecting raw materials of the vibration damping member for the bottom plate. Figure 2 B is the cross-sectional view of the mold after mold closing. Figure 2 C is a cross-sectional view of the polyurethane foam layer that is foamed and formed integrally with the fiber layer in the mold.

[0012] Figure 3 It is a cross-sectional view of a test apparatus for a vibration damping test.

[0013] exist Figure 4 middle, Figure 4 A is a table showing the characteristics of the examples and comparative examples, Figure 4 B is a graph showing stress-strain curves of Examples 2, 4, 6 and Comparative Example 1.

[0014] Figure 5 This is a graph showing the stress-strain curve of the example until the compressive strain reaches 3%.

[0015] exist Figure 6 middle, Figure 6A is a graph showing the resonant frequency and vibration transmissibility of the embodiment and the comparative example, Figure 6 B is a graph showing the resonant frequency and vibration transmissibility of an example using a floor vibration damping member having a polyurethane foam layer. DETAILED DESCRIPTION

[0016] [First embodiment]

[0017] like Figure 1 A and Figure 1 As shown in FIG. 2B , the floor vibration damping member 10 according to the first embodiment of the present invention is used in a motor vehicle 90 and is placed on the bottom surface 90M of the vehicle body (i.e., the upper surface of the floor panel 91). For example, the floor vibration damping member 10 is used as a sound insulation material or a heightening material having a sound insulation and sound absorption function, and has a polyurethane foam layer 11. For example, a fiber layer 20 such as a floor carpet is laid on the polyurethane foam layer 11. It should be noted that, for example, when the upper surface of the floor panel 91 has a concavo-convex shape, the floor vibration damping member 10 is formed to have a concavo-convex shape corresponding thereto.

[0018] like Figure 1 As shown in B, the floor vibration damping material 10 of the present embodiment is in a sheet shape and has a two-layer structure including a urethane foam layer 11 and a fiber layer 20 laminated on the urethane foam layer 11 .

[0019] The polyurethane foam layer 11 can be composed of molded polyurethane obtained by molding (foaming molding in a mold), or it can be composed of slab polyurethane obtained by plate molding (foaming molding on an open continuous production line). The bottom plate vibration damping member 10 requires a certain degree of rigidity and hardness so as not to sink excessively when stepped on by the passengers. Therefore, the polyurethane foam layer 11 is preferably molded polyurethane. Molded polyurethane is foamed in a mold, so the apparent density can be increased. In addition, molded polyurethane forms a skin layer on the surface portion that contacts the molding surface of the mold. Therefore, molding can produce polyurethane foam with excellent hardness and durability. The skin layer is a surface layer with a higher apparent density relative to the inner part of the polyurethane foam layer 11.

[0020] In the example of the present embodiment, the polyurethane foam layer 11 is made of molded polyurethane and has a skin layer. The skin layer is formed as a surface layer of the first surface 11F on the opposite side of the fiber layer 20 in the front and back of the polyurethane foam layer 11, and also as an outer peripheral surface 11E connecting the front and back surfaces (see Figure 2 In particular, the skin layer of the outer peripheral surface 11E can improve the rigidity in the thickness direction of the polyurethane foam layer 11. When the polyurethane foam layer 11 and the fiber layer 20 are formed separately, the skin layer can also be provided on the fiber layer 20 side of the polyurethane foam layer 11.

[0021] The polyurethane foam layer 11 may be air-permeable (e.g., a continuous cell structure) or non-air-permeable (e.g., a closed cell structure). When the polyurethane foam layer 11 is air-permeable, the entire floor vibration damping member 10 can be air-permeable, thereby improving the sound absorption. It should be noted that in the example of the present embodiment, the polyurethane foam layer 11 is air-permeable and the skin layer is also air-permeable. Thus, the polyurethane foam layer 11 can improve both rigidity and sound absorption.

[0022] It should be noted that the cell membranes (so-called mirror surfaces) between the foamed cells of the foamed body can be removed, for example, by explosion waves of combustion gas, hydrolysis based on alkali, etc., but are preferably not removed and left. Due to the presence of the cell membranes, the vibration damping properties of the foamed body can be improved compared to the case where there is no cell membrane.

[0023] From the viewpoints of the above-mentioned rigidity, hardness, etc., the apparent density of the polyurethane foam layer 11 is preferably, for example, 40 kg / m 3 More preferably 45kg / m 3 In addition, from the viewpoint of weight reduction, the apparent density of the polyurethane foam layer 11 is preferably, for example, 80 kg / m 3 Below, more preferably 75kg / m 3 As described above, by reducing the weight of the polyurethane foam layer 11, when the floor damping member 10 is mounted on a vehicle such as an automobile 90, for example, the fuel consumption or power consumption of the vehicle can be reduced.

[0024] The fiber layer 20 is integrated with the upper surface (second surface 11S) of the polyurethane foam layer 11. The fiber layer 20 is composed of a fiber sheet such as a non-woven fabric, for example. In the example of the present embodiment, the vibration damping member 10 for the floor is an integrally formed product in which the polyurethane foam layer 11 and the fiber layer 20 are foamed and molded into one. For example, an impregnation layer formed by impregnating and curing the raw material of the polyurethane foam layer 11 may be formed in at least the portion of the fiber layer 20 that is opposite to the polyurethane foam layer 11. In the example of the present embodiment, the fiber layer 20 including the impregnation layer has air permeability as a whole.

[0025] It should be noted that the fibers constituting the fiber layer 20 may be either synthetic fibers or natural fibers. Examples of such fibers include polyethylene terephthalate (PET) fibers, polyester fibers, polypropylene fibers, polyamide fibers, acrylic fibers, vinylon fibers, polyurethane fibers (spandex), glass fibers, carbon fibers, and ZYLON (registered trademark). Examples of natural fibers include wool, cotton, and cellulose nanofibers. In addition, the fiber layer 20 is not limited to nonwoven fabrics, and may be textiles, woven fabrics, and the like. Examples of nonwoven fabrics include spunlace nonwoven fabrics, spunbond nonwoven fabrics, and needle-punched nonwoven fabrics.

[0026] However, from the viewpoint of improving quietness, etc., vibration damping is sought for bottom plate members used in the bottom plates of vehicles or buildings, etc. Therefore, vibration damping is also sought for existing bottom plate members such as bottom plate members placed on the bottom panel 91, etc. In view of this, in the bottom plate vibration damping member 10 of the present embodiment, by having a polyurethane foam layer 11, the vibration damping can be improved compared to a bottom plate member having only a fiber layer. Here, in order to further improve the vibration damping, the inventors of the present application conducted a detailed investigation on the relationship between the vibration damping and the characteristics of the foam. And, as a result of the in-depth study, by focusing on the elastic modulus of the foam, the insight that the vibration damping can be further improved was obtained, and thus the bottom plate vibration damping member 10 of the present invention was invented.

[0027] Specifically, in the vibration damping member 10 for the floor, the average elastic modulus of the polyurethane foam layer 11 in the range of 0 to 3% of the compressive strain (the range of the compressive strain being greater than 0 and less than 0.03) is preferably less than 400 kPa. As a result, as described below, a significant improvement in vibration damping can be achieved. Here, the average elastic modulus in the range of 0 to 3% of the compressive strain is obtained as the slope of an approximate straight line in the range of 0% to 3% of the strain relative to the stress-strain curve when the polyurethane foam layer 11 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).

[0028] It should be noted that in the polyurethane foam layer 11, in the stress-strain curve, the compressive strain corresponding to the proportional limit (the limit at which the stress increases linearly with respect to the increase in strain) is 3% (0.03) or more (that is, within the range of 0 to 3% of the compressive strain below the proportional limit, the stress at least increases linearly with respect to the increase in the compressive strain. For example, refer to Figure 4 B).

[0029] Here, if the average elastic modulus of the polyurethane foam layer 11 is low, it is considered that the above-mentioned rigidity and hardness are reduced. Therefore, the average elastic modulus of the polyurethane foam layer 11 is preferably 170 kPa or more.

[0030] As described later, the floor vibration damper 10 can significantly suppress vibrations of, for example, 100 to 400 Hz. Therefore, according to the vibration control method in which the floor vibration damper 10 is placed on the bottom surface 90M of the vehicle body, the vibration of the floor panel 91 of 100 to 400 Hz can be particularly suppressed. Such a floor vibration damper 10 for controlling vibrations of 100 to 400 Hz or a vibration control method of 100 to 400 Hz using the floor vibration damper 10 has not existed so far, and can produce a significant effect that cannot be predicted based on the existing technical level.

[0031] In addition, the floor vibration damping member 10 can be used for both gasoline vehicles and electric vehicles. In the case of electric vehicles, since there is no engine noise, the sound caused by the vibration of the floor panel 91 may be easily noticeable. However, by using the floor vibration damping member 10 in an electric vehicle, the vibration of the floor panel 91 can be effectively suppressed, and in particular, the quietness can be improved.

[0032] The floor vibration damping member 10 of the present embodiment is manufactured, for example, as follows. First, a raw material 11G of the polyurethane foam layer 11 is prepared (see Figure 2 A) and a fiber sheet as the fiber layer 20. Specifically, as the raw material 11G, a raw material containing a polyol component, a polyisocyanate component, a foaming agent, a catalyst, and the like is prepared.

[0033] exist Figure 2 A shows a mold 50 for foaming and molding the polyurethane foam layer 11. The mold 50 includes a lower mold 51 and an upper mold 52. In an open mold state where the lower mold 51 and the upper mold 52 are separated, a fiber sheet as the fiber layer 20 is arranged on a molding surface 52M of the upper mold 52. A molding concave portion 51U is provided on the molding surface of the lower mold 51 to form a cavity for foaming and molding the polyurethane foam layer 11. Then, the raw material 11G is injected into the molding concave portion 51U, and the lower mold 51 and the upper mold 52 are closed, thereby closing the mold 50 (see Figure 2 B).

[0034] Then, if Figure 2 As shown in C, the raw material 11G is foamed and cured in the cavity of the closed mold 50, thereby forming the polyurethane foam layer 11 integrated with the fiber layer 20. For example, at this time, the raw material 11G is impregnated into the fiber layer 20 and cured to form an impregnated layer.

[0035] By such molding, a skin layer is formed on the surface portion of the polyurethane foam layer 11 other than the second surface 11S integrated with the fiber layer 20. If the skin layer has air permeability, the gas during molding can be easily released to the outside.

[0036] The skin layer having air permeability can be easily formed by using a straight-chain hydrocarbon wax as a mold release agent of the mold 50. The mold release agent is applied to the molding surface of the mold 50 before injecting the raw material 11G.

[0037] As the above-mentioned straight-chain hydrocarbon wax, for example, paraffin wax, Fischer-Tropsch wax, Sasol wax, etc. can be listed, for example, a solvent-based release agent dispersed in an organic solvent, a water-based release agent dispersed in water using an emulsifier, etc. can be used. In addition, in order to form a skin layer, a branched hydrocarbon wax can also be used as a release agent. As the branched hydrocarbon wax, for example, microcrystalline wax, modified polyethylene wax, etc. can be listed, for example, a solvent-based release agent or a water-based release agent can be used.

[0038] When from Figure 2 When the integrated polyurethane foam layer 11 and fiber layer 20 are removed from the mold 50 shown in C, the floor vibration damping member 10 is obtained. It should be noted that, when the polyurethane foam layer 11 is obtained by plate molding, for example, the fiber layer 20 can be bonded to the polyurethane foam layer 11 to obtain the floor vibration damping member 10.

[0039] [Other embodiments]

[0040] In the above embodiment, the polyurethane foam layer 11 and the fiber layer 20 are integrally formed, but only the polyurethane foam layer 11 may be formed and a fiber layer such as a carpet may be placed on the polyurethane foam layer 11 .

[0041] In the above embodiment, the floor vibration damping member 10 is used in the automobile 90, but it can also be used in vehicles such as railway vehicles or ships and placed on the bottom surface of the vehicle. In addition, the floor vibration damping member 10 can also be used in buildings, for example, and can also be placed on the bottom surface of a building.

[0042] In the above-described embodiment, the floor vibration damping member 10 is placed on the bottom surface, but it may be brought into close contact with the bottom surface material from below.

[0043] In the above embodiment, the skin layer of the polyurethane foam layer 11 is provided on the first surface 11F side of the front and back of the polyurethane foam layer 11, but it may be provided on the second surface 11S side opposite to the first surface 11F. In this case, for example, the polyurethane foam layer 11 having the skin layer on both sides of the front and back is foam-molded in the mold 50, and then the fiber layer 20 is bonded or placed on the polyurethane foam layer 11 using an adhesive material, thereby obtaining the vibration damping member 10 for the floor. It should be noted that the skin layer of the polyurethane foam layer 11 obtained by molding can also be sliced ​​and cut off appropriately. It is also possible to make the polyurethane foam layer 11 have a structure in which the skin layer is not provided on at least a part of the first surface 11F, the second surface 11S or the outer peripheral surface 11E.

[0044] The floor vibration damping member 10 has a double-layer structure in the above embodiment, but it may also have a stacked structure of three or more layers. For example, the fiber layer 20 may not form a stacked structure, for example, it may also be composed of a plurality of stacked fiber sheets. In addition, other layers may be stacked between the polyurethane foam layer 11 and the fiber layer 20, and other layers may be provided below the polyurethane foam layer 11 or above the fiber layer 20. It should be noted that the floor vibration damping member 10 may also be a single-layer structure of the polyurethane foam layer 11.

[0045] In the above-described embodiment, a foam layer of a polyolefin resin such as polyethylene foam or polypropylene foam, or a foam layer of a phenolic resin may be provided instead of the polyurethane foam layer 11 of the floor vibration damping member 10 .

[0046] In the above-mentioned embodiment, a skin layer not containing fibers may be provided instead of the fiber layer 20. As such a skin layer, for example, a skin layer composed of an air-permeable or air-impermeable resin sheet can be cited.

[0047] [Example]

[0048] Hereinafter, the above-mentioned embodiment will be described in more detail with reference to Examples and Comparative Examples. However, the vibration damping material for a floor of the present invention is not limited to the following Examples.

[0049] 1. Configuration of Examples and Comparative Examples

[0050] against Figure 4 Examples 1 to 8 and Comparative Examples 1 and 2 shown in A were evaluated. The vibration damping members for the respective bottom plates were made of different materials. It should be noted that in Examples 1 to 8, Figure 4 The apparent density, hardness, and average elastic modulus in A were measured in a state where only the polyurethane foam layer 11 was present.

[0051] <Examples 1 to 5>

[0052] The floor vibration damping members 10 of Examples 1 to 5 are formed by molding a single body of a polyurethane foam layer 11 , a first surface 11F and a second surface 11S opposite thereto and an outer peripheral surface 11E, and have air permeability.

[0053] <Examples 6 to 8>

[0054] The vibration damping members for floors of Examples 6 to 8 are polyurethane foam layers 11 obtained by plate molding, and no skin layer is formed on the polyurethane foam layer 11 .

[0055] <Comparative Example 1>

[0056] Comparative Example 1 is mixed felt (recycled fiber product).

[0057] <Comparative Example 2>

[0058] Comparative Example 2 is a body without the vibration damping member for the bottom plate.

[0059] 2. Evaluation

[0060] The vibration damping properties of the examples and comparative examples were evaluated (see Figure 4 A) The evaluation methods of various properties of Examples and Comparative Examples are as follows.

[0061] <Evaluation method>

[0062] (1) Apparent density

[0063] The density of the floor vibration damping member is measured in accordance with JIS K7222.

[0064] (2) Average elastic modulus

[0065] The samples of Examples 1 to 8 and Comparative Example 1 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% of the compression strain. In Examples 1 to 8, only the polyurethane foam layer 11 was used as the measurement sample. The size of each measurement sample was 100 mm × 100 mm × 20 mm (thickness). In addition, the pressure member (the pressing surface was a circle with a diameter of 50 mm) was pressed against the center of the plane shape of the measurement sample and compressed at a speed of 50 mm / min until the compression strain of the measurement sample became 70% (the thickness became 30% 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 3% 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 3%.

[0066] (3) Hardness

[0067] Regarding the hardness of the floor vibration damping member, in the compression test for calculating the above average elastic modulus, the stresses applied to the pressurizing member when the compressive strain of the measurement sample becomes 25% and 50% are defined as 25% compression hardness and 50% compression hardness, respectively.

[0068] Here, if the weight of a person sitting on the floor vibration damping member is 65 kg and the area of ​​both feet is 0.05 m 2 , the vibration damping member on the floor is applied with 12.740 kPa (1300 kg / m 2 ) stress. And, if the polyurethane foam layer 11 is compressed by more than 25% and sinks when subjected to such stress, it is considered that it is not suitable as a vibration damping member for the base plate. Therefore, the 25% compression hardness of the polyurethane foam layer 11 is particularly preferably 13 kPa or more. In addition, if the vibration damping member for the base plate is too hard, the cushioning property and the like become unsuitable, so the 25% compression hardness of the polyurethane foam layer 11 is preferably 30 kPa or less. From this point of view, in the evaluation of hardness, when the 25% compression hardness of the polyurethane foam layer 11 is more than 13 kPa and less than 30 kPa, it is evaluated as ◎, when the 25% compression hardness of the polyurethane foam layer 11 is more than 10 kPa and less than 13 kPa, it is evaluated as ○, and when the 25% compression hardness of the polyurethane foam layer 11 is less than 10 kPa or greater than 30 kPa, it is evaluated as ×.

[0069] (4) Vibration reduction

[0070] The vibration damping properties of the embodiments and comparative examples were compared. Figure 3 As shown in . In the test device, the evaluation sample 11A (the polyurethane foam layer 11 in Examples 1 to 8 and the mixed felt in Comparative Example 1) is fixed on the steel plate 91A as the bottom plate 91, and the steel plate 91A is given vibration, and the vibration damping property brought by the evaluation sample 11A 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 upward from the outer edge of the plate-shaped bottom 64, and the lower frame 62 is fixed to the upper end of the side wall portion 65 (for example, formed integrally 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 attached to the center portion of the lower surface of the steel plate 91A. It should be noted that the frequency of the vibration of the spring is much lower than the frequency of a resonance peak described later.

[0071] The evaluation samples 11A of the embodiments and comparative examples were placed on the steel plate 91A, and the fiber layer 20 was stacked from above. The plane size of the evaluation sample 11A was 500 mm × 400 mm and the thickness was 20 mm. The steel plate 91A was 600 mm × 500 mm × 0.8 mm (thickness), and the fiber layer 20 was 500 mm × 400 mm × 1.0 mm (thickness) and the unit area weight was 1600 g / m 2 The steel plate 91A, the bottom plate vibration damping member, and the fiber layer 20 are arranged so that the long side directions are the same.

[0072] 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.

[0073] 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 Figure 6 A and Figure 6 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. Figure 6The peak indicated by the arrow in B) was used to evaluate the vibration transmissibility (the height of the resonance peak).

[0074] Regarding the vibration damping property, when the average value of the vibration transmissibility of the above four peaks is 13 dB or less, it is evaluated as ◎, when the average value of the vibration transmissibility of the above four peaks is more than 13 dB and less than 16 dB, it is evaluated as ○, and when the average value of the vibration transmissibility of the above four peaks is more than 16 dB, it is evaluated as ×. It should be noted that the lower the vibration transmissibility, the better the vibration damping property.

[0075] (5) Comprehensive evaluation

[0076] When both the vibration damping evaluation and the hardness evaluation were ○ or higher, the comprehensive evaluation was ◎. When the vibration damping evaluation was ○ or higher but the hardness evaluation was ×, the comprehensive evaluation was ○. If the vibration damping evaluation was ×, the comprehensive evaluation was ×.

[0077] <Evaluation Results>

[0078] like Figure 4 As shown in A, in the vibration damping parts for the floor of Examples 1 to 3, 5, and 6 having the polyurethane foam layer 11, it can be confirmed that the vibration damping property is greatly improved (the vibration damping property evaluation is ○ or more) compared with Comparative Example 1 composed of non-woven fabric and Comparative Example 2 without the vibration damping part for the floor. In addition, the average elastic modulus (the slope of the approximate straight line. Refer to Figure 5 ) is less than 400 kPa, it can be confirmed that the vibration damping parts for the bottom plate of Examples 1 to 3 and 6 can exert particularly excellent vibration damping performance compared with the vibration damping parts for the bottom plate of Example 5 in which the average elastic modulus exceeds 400 kPa. It should be noted that in Examples 1 to 8, in the stress-strain curve, the compressive strain corresponding to the proportional limit is 3% (0.03) or more (that is, the stress increases linearly with respect to the increase in strain up to at least 3%. Refer to, for example Figure 4 B).

[0079] In Example 6, the vibration damping performance was evaluated as good, but the 25% compression hardness of the polyurethane foam layer 11 was 10 kPa or less (hardness evaluation ×). In contrast, from the results of Examples 1 to 3 and 8, it can be seen that when the average elastic modulus is 170 kPa or more, the 25% compression hardness is also 13 kPa or more, and the hardness is also good in addition to the vibration damping performance of the floor vibration damping member. In Examples 1 to 3, the 50% compression hardness is preferably 20 kPa or more and 50 kPa or less.

[0080] As described above, it was confirmed that the floor vibration damping members of Examples 1 to 3 having the average elastic modulus of 170 kPa or more and less than 400 kPa exhibited excellent effects in terms of both vibration damping properties and hardness with respect to vibrations of 100 to 400 Hz.

[0081] <Notes>

[0082] Hereinafter, a feature group extracted from the above-described embodiment and examples will be described while showing effects and the like as necessary.

[0083] For example, the following feature group is about a vibration damping member for a floor and a vibration control method and is aimed at "In the past, various floor members have been developed (for example, see Japanese Patent Laid-Open No. 9-95169 (Paragraphs 0006, Figure 1 Such background technology as "seeking a vibration reduction function for existing floor members" is conceived as a subject. In addition, new floor vibration reduction members or vibration control methods have always been sought.

[0084] [Feature 1]

[0085] A vibration damping member for a floor, comprising a polyurethane foam layer.

[0086] According to this feature, the vibration damping function of the floor vibration damping member can be exerted.

[0087] [Feature 2]

[0088] In the floor vibration damping member according to feature 1, the average elastic modulus of the polyurethane foam layer in the range of a compressive strain of 0 to 3% is 170 kPa to 400 kPa.

[0089] According to this feature, the vibration damping property of the base plate vibration damper can be further improved. In addition, by setting the average elastic modulus to 170 kPa or more (e.g., 180 kPa or more) as in this feature, it is possible to prevent the base plate vibration damper from being compressed and sinking excessively when pressed from above, such as when stepped on by a foot.

[0090] [Feature 3]

[0091] In the floor vibration damping member according to feature 1 or 2, the floor vibration damping member includes a fiber layer laminated on the polyurethane foam layer.

[0092] [Feature 4]

[0093] In addition to the floor vibration damping member described in any one of Features 1 to 3, the floor vibration damping member is used in an electric vehicle.

[0094] [Feature 5]

[0095] In addition to the floor vibration damping member described in any one of Features 1 to 4, the floor vibration damping member is used to control vibrations of 100 to 400 Hz.

[0096] [Feature 6]

[0097] In the floor vibration damping member according to any one of Features 1 to 5, the 25% compression hardness of the polyurethane foam layer is 10 kPa or more and 30 kPa or less.

[0098] According to this feature, it is possible to suppress the bottom plate vibration damping member from being compressed and excessively sinking when pressed from above, for example, when stepped on by a foot, and to allow the bottom plate vibration damping member to have an appropriate hardness.

[0099] [Feature 7]

[0100] A method for controlling vibrations of 100 to 400 Hz, characterized in that the floor vibration damping member described in any one of features 1 to 6 is placed on the bottom surface of a vehicle body.

[0101] [Feature 8]

[0102] A floor structure, wherein the floor vibration damping member described in any one of features 1 to 6 is mounted on the bottom surface of a vehicle body.

[0103] According to this feature, the vibration of the floor panel of the vehicle body can be reduced.

[0104] 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.

[0105] Description of Reference Numerals

[0106] 10 vibration-damping member for the base plate; 11 polyurethane foam layer; 20 fiber layer.

Claims

1. A vibration damping member for a base plate, wherein: The floor vibration damping member has a polyurethane foam layer.

2. The vibration damping member for a floor according to claim 1, wherein: The average elastic modulus of the polyurethane foam layer within a range of a compressive strain of 0 to 3% is 170 kPa or more and 400 kPa or less.

3. The vibration damping member for a floor according to claim 1 or 2, wherein: The floor vibration damping member has a fiber layer laminated on the polyurethane foam layer.

4. The vibration damping member for a floor according to claim 1 or 2, wherein: The vibration damping member for a floor panel is used in an electric vehicle.

5. The vibration damping member for a floor according to claim 1 or 2, wherein: The vibration damping member for the bottom plate is used to control vibrations of 100 to 400 Hz.

6. The vibration damping member for a floor according to claim 1 or 2, wherein: The polyurethane foam layer has a 25% compression hardness of 10 kPa or more and 30 kPa or less.

7. A method for controlling vibration of 100 to 400 Hz, characterized in that: The floor vibration damping member according to claim 1 or 2 is mounted on the bottom surface of a vehicle body.

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