Sound-absorbing materials for vehicles

Abstract

[Subject] Provide a sound-absorbing material for a vehicle, which can maintain the clarity of conversation between rear seat passengers and front seat passengers, while absorbing unnecessary sounds in the vehicle interior. [Solution] A sound-absorbing material for a vehicle, which has at least a main body formed by integrally molding a fiber material and a surface material and is installed in the vehicle interior, characterized in that the sound-absorbing part provided in at least a part of the main body is installed in the vehicle interior in a manner such that the vertical distance Elh from the lower surface of the headrest of the front seat to the bottom is within the range of 0.1 to 0.4 m, and the ventilation resistance AFR (Ns / m 3 ) and the vertical distance Elh (m) satisfy the relationship of 210<AFR+10 / Elh<3020.

Description

Technical Field

[0001] The present invention relates to a sound absorbing material for a vehicle. Background Art

[0002] In vehicles such as automobiles, it is known to use sound-absorbing materials that improve the aesthetics of the interior of the vehicle while absorbing unnecessary sounds. In addition, a multi-layer decorative part for automobiles is known, which has a breathable intermediate film layer between two fiber layers for sound absorption, and has a total airflow resistance (AFR) of 4 to 12.5 mm in the thickness region. overall : The unit is Ns / m 3 ) and overall density ρ(kg / m 3 ) has 1500<AFR overall The relationship is -10ρ<3800 (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2017-533142 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the conventional front panel heat insulation layer or carpet, the ventilation resistance is set relatively high to improve the sound absorption effect, and the sound absorption effect is also achieved in the frequency band of passenger conversation. Therefore, if the sound absorption material formed of the same material is arranged on the back of the front seat near the ear position of the passenger, when the rear seat passenger talks with the front seat passenger, the voice of the rear seat passenger will be absorbed, and there is a problem that the conversation becomes difficult.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle sound absorbing material that can maintain the clarity of conversation between rear seat passengers and front seat passengers and absorb unnecessary sounds in the vehicle interior.

[0009] Means for solving problems

[0010] In order to solve the above-mentioned problems and achieve the purpose, a vehicle sound absorbing material according to one embodiment of the present invention comprises at least a main body formed by integrally molding a fiber material and a surface material and is installed in a vehicle interior, wherein the sound absorbing portion provided in at least a part of the main body is installed in the vehicle interior in such a manner that a vertical distance Elh downward from a lower surface of a headrest of a front seat is within a range of 0.1 to 0.4 m, and a ventilation resistance AFR (Ns / m 3 ) and the vertical distance Elh (m) satisfy the relationship of 210<AFR+10 / Elh<3020.

[0011] In one aspect of the present invention, a vehicle sound absorbing material is characterized in that the sound absorbing portion is overlapped with a non-air-permeable material on a side of the fiber material opposite to the surface material.

[0012] In addition, a vehicle sound absorbing material according to one aspect of the present invention is characterized in that the non-air-permeable material is an non-air-permeable film.

[0013] In one aspect of the present invention, the vehicle sound absorbing material is characterized in that the sound absorbing portion includes a foaming material such as polyurethane having a thickness of 5 mm to 15 mm between the fiber material and the skin material.

[0014] In one aspect of the present invention, the vehicle sound absorbing material is characterized in that the sound absorbing portion has a sound absorption rate at 1000 Hz or higher that is higher than a sound absorption rate at less than 1000 Hz.

[0015] Effects of the Invention

[0016] According to the present invention, the following effects are achieved: the clarity of conversation between rear seat passengers and front seat passengers is maintained, and unnecessary sound in the vehicle interior can be absorbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a perspective view showing an example of a state where a vehicle sound absorbing material according to one embodiment is viewed from the front side.

[0018] Figure 2 This is a perspective view illustrating a state in which a vehicle sound absorbing material according to one embodiment is attached to the back side of a front seat in a vehicle cabin.

[0019] Figure 3 This is a diagram illustrating the configuration of the back side of the vehicle sound absorbing material.

[0020] Figure 4 It is a diagram schematically showing a cross section of an integrally molded main body portion.

[0021] Figure 5 It is a perspective view schematically illustrating a fixing portion.

[0022] Figure 6 In (a), it is shown Figure 1 (b) is a diagram showing the cross-sectional structure at line AA. Figure 1 A diagram of the cross-sectional structure at line BB is shown.

[0023] Figure 7 In (a), they are Figure 6 The first enlarged view of the end portion in (a). (b) Figure 6 A second enlarged view of the terminal portion in (a).

[0024] Figure 8 This is a graph showing the results of experimentally measuring the relationship between the ratio of the actual width to the linear distance width and the strength ratio of the terminal portion of the vehicle sound absorbing material.

[0025] Fig. 9 This is a diagram illustrating the position where the vehicle sound absorbing material is installed in the vehicle interior by arranging the sound absorbing portion.

[0026] Fig.10 This is a graph illustrating the sound absorption characteristics of a member disposed in a vehicle interior.

[0027] Fig.11 This is a diagram showing a configuration example of a first modified example of a vehicle sound absorbing material as viewed from the back side.

[0028] Fig.12 It is a diagram showing a second modified example of the vehicle sound absorbing material.

[0029] Fig.13 , (a) is a diagram showing a first modified example of the sound absorbing portion, and (b) is a diagram showing a second modified example of the sound absorbing portion.

[0030] Fig.14 It is a diagram showing a third modified example of the sound absorbing part.

[0031] Fig.15 It is a diagram showing a fourth modified example of the sound absorbing portion.

[0032] Fig.16 It is a diagram showing characteristics of the first to third modified examples of the sound absorbing portion. DETAILED DESCRIPTION

[0033] Hereinafter, one embodiment of a vehicle sound absorbing material will be described with reference to the drawings. Figure 1 1 is a perspective view showing a state where a vehicle sound absorbing material 1 according to one embodiment is viewed from the front side. Figure 2 This is a perspective view illustrating a state in which the vehicle sound absorbing material 1 according to one embodiment is attached to the back side of a front seat 50 in a vehicle cabin.

[0034] like Figure 1 and Figure 2 As shown, the vehicle sound absorbing material 1 is integrally formed with a main body 10 so that it can be installed in a vehicle interior without providing a mounting hole on the surface side. A sound absorbing part 12 having a predetermined ventilation resistance is provided at the approximate center of the main body 10. Figure 2The thickness of the area indicated by the middle oblique lines may be thicker than other areas to make the sound absorption characteristics different from those of other areas. For example, the sound absorption characteristics of the sound absorbing portion 12 are set so as to suppress the absorption of the sound of the passenger conversation while absorbing other unnecessary sounds in the vehicle interior.

[0035] The main body 10 is formed with a terminal portion 14 by compressing the peripheral terminal. The terminal portion 14 is formed with a bent portion 16 formed at the side and upper portion of the main body 10, for example.

[0036] In the vehicle sound absorbing material 1, the bent portion 16 formed on the side and upper portion of the main body 10 matches the roundness of the back periphery of the front seat 50 and is fixed along the back side of the front seat 50. Here, the terminal portion 14 formed on the lower portion of the main body 10 is bent below the front seat 50.

[0037] Figure 3 2 is a diagram showing an example of the structure of the back side of the vehicle sound absorbing material 1. Figure 3 As shown in FIG. 1 , the sound absorbing portion 12 is disposed approximately in the center of the main body 10 to widen the area having the sound absorbing function. In addition, two or more fixing portions 18 are provided on the back side of the terminal portion 14 at intervals of, for example, 50 to 220 mm to be fixed to the front seat 50. In addition, when the vehicle sound absorbing material 1 is mounted on the front seat 50, a load is generated between the fixing portions 18 and the fixing portions 18. The shape and structure of the fixing portion 18 are determined by using the fixing portion 18. Figure 5 The following will be described. In addition, the terminal portion 14 is compression-molded to be continuous between two or more fixing portions 18, and a bent portion 16 is formed. In addition, the sound absorbing portion 12 is adjacent to the terminal portion 14 with a step difference on the inner side of the terminal portion 14, and is provided between two or more fixing portions 18 to absorb the sound in the vehicle interior. In addition, in order for the bent portion 16 to be continuous between two or more fixing portions 18 roughly along the step difference, at least a portion of the terminal portion 14 is bent.

[0038] Figure 4 Schematically shows a cross section of the integrally formed main body 10. Figure 4 As shown, the main body 10 is formed by, for example, stacking and integrally molding a first fiber material 100 , a second fiber material 102 , a PE powder 104 , and a skin 106 .

[0039] The first fiber material 100 is, for example, 900 g / m 2 The second fiber material 102 is made of, for example, 200 g / m 2 PE powder 104 is, for example, 100 g / m 2 The surface 106 is, for example, 150 g / m 2The surface material of tricot warp knitted fabric etc.

[0040] Figure 5 1 is a perspective view showing an outline of the fixing portion 18. The fixing portion 18 is formed of, for example, plastic, and has an adhesive surface 182 provided on the lower surface of a joint protrusion 180. The joint protrusion 180 can be mechanically coupled to two or more joint portions (not shown) provided on the back side of the front seat 50 by utilizing the elasticity of the material without using an adhesive. The adhesive surface 182 is provided for the purpose of fixing the fixing portion 18 to the terminal portion 14 of the vehicle sound absorbing material 1 by utilizing an adhesive.

[0041] Next, the structure of the main body 10 will be described in detail.

[0042] Figure 6 2 is a diagram showing a cross-sectional structure of the main body 10 . Figure 6 (a) shows Figure 1 A diagram of the cross-sectional structure at line AA is shown. Figure 6 (b) shows Figure 1 The cross-sectional structure at line BB is shown. Figure 7 (a) and (b) are Figure 6 (a) is an enlarged view of the terminal portion 14.

[0043] like Figure 6 As shown in (a), the sound absorbing part 12 is not compressed like the terminal part 14, but is disposed substantially in the center of the main body 10 and has a predetermined ventilation resistance. Figure 6 As shown in (b), the sound absorbing portion 12 is not compressed like the terminal portion 14, and the thickness of the main body 10 is approximately the same as that of the terminal portion 14. Figure 6 The part shown in (a) is thick, and the sound absorption characteristics are Figure 6 The part shown in (a) has changed.

[0044] In addition, the terminal portion 14 is bent at the position X and the position Y, and the end portion is bent, thereby forming a bent portion 16. Figure 7 As shown in (a), the portion of the bent portion 16 bent at position X makes the ratio of the actual width (actual length) L2 to the linear distance width L1 greater than 1 and less than 1.3. That is, in the bent portion 16, the ratio of the actual width from the step to the outer end of the terminal portion 14 to the linear distance width is greater than 1 and less than 1.3. There are two or more steps, and the step on the sound absorbing portion 12 side is higher than the step on the terminal portion 14 side.

[0045] In addition, if Figure 7As shown in (b), the parts of the bent portion 16 bent at the position X and the position Y make the ratio of the actual width L2 to the linear distance width L1 greater than 1 and less than 1.3. That is, when the bent portion 16 is bent multiple times in the width direction, the ratio of each actual width L2 to the linear distance width L1 and the ratio of the overall actual width L2 to the linear distance width L1 are greater than 1 and less than 1.3.

[0046] Figure 8 Graph showing the relationship between the ratio of the actual width L2 to the linear distance width L1 and the strength ratio of the terminal portion 14 in the vehicle sound absorbing material 1, as measured by experiments. Figure 8 In the figure, the interval between the fixing parts 18 and the fixing parts 18 provided at the terminal part 14 is set to 58 mm, and the 58 mm is used as the interval of the fulcrum, and the displacement amount when the load is applied to the terminal part 14 is measured, and the strength when the ratio of the actual width L2 to the linear distance width L1 in this case is 1 is used as a reference (strength = 1), and the strength ratio of the terminal part 14 is shown. Here, when the ratio of the actual width L2 to the linear distance width L1 is 1, it means that the terminal part 14 is not bent and is flat.

[0047] thus, Figure 8 The curve shown in A in the middle shows the relationship between the ratio of the actual width L2 to the linear distance width L1 and the strength of the terminal portion 14 when the interval between the fulcrums (the interval between the fixing portions 18 and the fixing portions 18) is set to 58 mm. Figure 8 The curve shown in B shows the relationship between the ratio of the actual width L2 to the linear distance width L1 and the strength of the terminal portion 14 when the interval between the fulcrums is set to 40 mm. Figure 8 The curve indicated by C in the middle shows the relationship between the ratio of the actual width L2 to the linear distance width L1 and the strength of the terminal portion 14 when the interval between the fulcrums is set to 200 mm.

[0048] like Figure 8 As shown, it was confirmed that the terminal portion 14 has a tendency to have the highest strength when the ratio of the actual width L2 to the linear distance width L1 is about 1.3, regardless of the length of the interval between the fulcrums (the interval between the fixing portions 18 and the fixing portions 18). Therefore, the terminal portion 14 is formed in such a manner that the ratio of the actual width L2 to the linear distance width L1 is greater than 1 and less than 1.3.

[0049] Next, the position where the vehicle sound absorbing material 1 is installed in the vehicle interior and the sound absorbing characteristics of the vehicle sound absorbing material 1 will be described.

[0050] Fig. 9 This is a diagram showing the position of the vehicle sound absorbing material installed in the vehicle interior by arranging the sound absorbing part. Figure 1The vehicle sound absorbing material 1 shown is formed such that the sound absorbing portion 12 is provided substantially at the center of the main body portion 10 so as to be mounted in the vehicle interior within a range of 0.1 to 0.4 m from the lower surface of the headrest 500 of the front seat 50 to the bottom of the vehicle.

[0051] In addition, when a vehicle sound absorbing material is provided between the front seat 50 and the rear seat 52, on the inner side of the door or the like on the rear seat 52 side, the sound absorbing portion 20 of the vehicle sound absorbing material is also provided so as to be installed in the vehicle interior within a range of a vertical distance Elh of 0.1 to 0.4 m from the lower surface of the headrest 500 of the front seat 50. In addition, when a vehicle sound absorbing material is provided between the instrument panel 54 and the front seat 50, on the inner side of the door or the like of the front seat 50 or on the surface of the instrument panel 54, as Fig. 9 As shown, the sound absorbing parts 20 and 30 of the vehicle sound absorbing material are also installed in the vehicle interior within a range of 0.1 to 0.4 m from the lower surface of the headrest 500 of the front seat 50 to the bottom of the vertical distance Elh.

[0052] Furthermore, even if the positions of the headrests 500 and 520 are changed by vertically raising or lowering the backrests of the front seat 50 and the rear seat 52, for example, by changing the slope within a range of about 0 to 30 degrees, the vertical distance Elh can be within a range of 0.1 to 0.4 m.

[0053] In addition, the sound absorbing part 12 has a ventilation resistance AFR (Ns / m 3 ) and the vertical distance Elh(m) are constructed in a manner that satisfies the following formula (1).

[0054] 210<AFR+10 / Elh<3020···(1)

[0055] It should be noted that the vehicle sound absorbing material 1 in the present application does not include the dash panel sound insulation pad 40 and the carpet 42. This is because the dash panel sound insulation pad 40 is provided between the passenger space and the engine room in the vehicle interior, and does not have a surface 106 in order to not easily attract the attention of the passengers, and is arranged at a position away from the ears and mouth of a general adult passenger. In addition, the carpet 42 is also arranged at a position away from the ears and mouth of a general adult passenger. That is, it is believed that the dash panel sound insulation pad 40 and the carpet 42 have a relatively low impact on the clarity of the conversation of the passengers.

[0056] Fig.10 This is a graph illustrating the sound absorption characteristics of a member disposed in a vehicle interior. Fig.10 The curve of A shows that the vertical distance Elh is small and the ventilation resistance AFR is 200 (Ns / m 3) is set to the sound absorption characteristics of the sound absorption part 12. In addition, the curve B shows that the vertical distance Elh is large and the ventilation resistance AFR is 3000 (Ns / m 3 ) is set to the sound absorption characteristics of the sound absorption portion 12. In addition, the curve C shows that the air flow resistance AFR of the carpet 42 as a comparative example is 1500 (Ns / m 3 ) and above.

[0057] like Fig.10 As shown, the sound absorbing part 12 is set to have a higher sound absorption rate above 1000 Hz than below 1000 Hz. This is because the frequency band that has a great influence on the clarity of passenger conversation is below 1000 Hz. In addition, the frequency band above 1000 Hz contains a large amount of unnecessary sound in the vehicle interior, which improves the sound absorption rate.

[0058] In this way, the sound absorbing part 12, the sound absorbing part 20 and the sound absorbing part 30 are respectively arranged in the vehicle interior in a manner such that the vertical distance Elh is within the range of 0.1 to 0.4 m. They are thus arranged at a lower position within the specified range that is closer to the ears and mouth of a general adult passenger. The above-mentioned sound absorbing characteristics can suppress the absorption of the sound of the passenger conversation and can absorb other unnecessary sounds in the vehicle interior.

[0059] Next, a modification of the vehicle sound absorbing material 1 will be described. Fig.11 1 is a diagram showing a configuration example of a first modified example (vehicle sound absorbing material 1a) of the vehicle sound absorbing material 1 as viewed from the back side. Hereinafter, substantially the same configuration is denoted by the same reference numerals.

[0060] like Fig.11 As shown, the vehicle sound absorbing material 1a is provided with a fastener 19 at the end of the bent portion 16. The fastener 19 can attach and detach any or a predetermined member to each part constituting the vehicle sound absorbing material 1a. For example, the fastener 19 can be configured to attach and detach the skin 106 in a replaceable manner.

[0061] Fig.12 FIG. 2 is a diagram showing a second modified example (vehicle sound absorbing material 2) of the vehicle sound absorbing material 1. Fig.12 As shown, the vehicle sound absorbing material 2 is configured to be mounted on the door 60 on the side of the rear seat 52, for example, and has Fig. 9 The sound absorbing part 20 is shown.

[0062] Next, a modification of the sound absorbing portion 12 will be described.

[0063] Fig.13 It is a diagram showing a modified example of the sound absorbing portion 12 . Fig.13 (a) is a diagram showing a first modification example (sound absorbing portion 12a) of the sound absorbing portion 12. Fig.13(b) is a diagram showing a second modification example (sound absorbing portion 12b) of the sound absorbing portion 12.

[0064] like Fig.13 As shown in (a) of FIG. 1 , the sound absorbing portion 12 a is formed by, for example, overlapping and integrally molding a third fiber material 108 , a rigid polyurethane 110 as a foaming layer, a PE powder 104 , and a skin 106 .

[0065] The third fiber material 108 is, for example, 1200 g / m 2 The hard polyurethane 110 is sandwiched between the third fiber material 108 and the skin 106, and has a thickness of 5 mm to 15 mm. For example, the thickness of the hard polyurethane 110 is 10 mm.

[0066] like Fig.13 As shown in (b), the sound absorbing portion 12b is formed by, for example, overlapping and integrally molding a fourth fiber material 112, a soft polyurethane 114 as a foaming layer, a PE powder 104, and a skin 106.

[0067] The fourth fiber material 112 is, for example, 600 g / m 2 The soft polyurethane 114 is sandwiched between the fourth fiber material 112 and the skin 106, and has a thickness of 5 mm to 15 mm. For example, the thickness of the soft polyurethane 114 is 10 mm.

[0068] It should be noted that both the sound absorbing part 12a and the sound absorbing part 12b have polyurethane as a foam layer with a thickness of 5 mm or more as a member other than the fiber, and the ventilation resistance is set to be greater than a specified value. This is because, for example, when the thickness of the polyurethane is 1 to 2 mm, which is less than 5 mm, the ventilation resistance is small and the effect on the acoustic characteristics is small. It should be noted that the foam layer is not limited to polyurethane, as long as it can be formed using a known foaming material.

[0069] Fig.14 1 is a diagram showing a third modified example (sound absorbing portion 12c) of the sound absorbing portion 12. Fig.14 As shown, the sound absorbing portion 12c is formed by, for example, overlapping and integrally molding the fourth fiber material 112, the PE powder 104, and the skin 106.

[0070] Fig.15 1 is a diagram showing a fourth modified example (sound absorbing portion 12d) of the sound absorbing portion 12. Fig.15 As shown, the sound absorbing portion 12d is formed by overlapping the non-air-permeable material 120 with respect to the sound absorbing portion 12c on the side opposite to the surface 106 of the fourth fiber material 112. For example, the non-air-permeable material 120 is a non-air-permeable film.

[0071] It should be noted that the sound absorbing part 12a, the sound absorbing part 12b, and the sound absorbing part 12c may also be provided with a non-air-permeable material 120.

[0072] Next, the characteristics of the first to third modified examples (the sound absorbing section 12a, the sound absorbing section 12b, and the sound absorbing section 12c) of the sound absorbing section 12 will be described.

[0073] Fig.16 1 is a diagram showing the characteristics of the first to third modified examples (sound absorbing part 12a, sound absorbing part 12b, sound absorbing part 12c) of the sound absorbing part 12. Fig.16 As shown, the surface density of the sound absorbing portion 12a is 1671 g / m 2 , thickness is 24.1mm, ventilation resistance AFR is 900Ns / m 3 The surface density of the sound absorbing part 12b is 1323 g / m 2 , thickness is 23.1mm, ventilation resistance AFR is 270Ns / m 3 The surface density of the sound absorbing part 12c is 1065 g / m 2 , thickness is 12.1mm, ventilation resistance AFR is 240Ns / m 3 .

[0074] In this way, according to an embodiment of the vehicle sound absorbing material, while utilizing the aesthetics of the vehicle sound absorbing material, the clarity of conversations between a driver sitting in a front seat and a passenger sitting in a front seat next to him, and between a passenger sitting in a front seat and a passenger sitting in a rear seat can be improved, and unnecessary sounds in the vehicle interior can be reduced.

[0075] Explanation of symbols

[0076] 1,1a,2···Sound absorbing material for vehicle, 10···Main body, 12, 12a, 12b, 12c, 12d, 20, 22, 30···Sound absorbing part, 14···Tip part, 16···Bending part, 18···Fixing part, 19···Fasteners, 50···Front seat, 52···Rear seat, 54···Instrument panel, 100···First fiber material, 102···Second fiber material, 104···PE powder, 106···Surface, 108···Third fiber material, 110···Hard polyurethane, 112···Fourth fiber material, 114···Soft polyurethane, 120···Non-breathable material, 180···Joint protrusion, 182···Adhesive surface, 500, 520···Headrest

Claims

1. A vehicle sound absorbing material installed in a vehicle interior, the vehicle sound absorbing material comprising a main body formed by at least a fiber material and a skin material being integrally formed and assembled in the vehicle interior, characterized in that: The main body has a sound absorbing portion provided on at least a portion of the main body, the sound absorbing portion being installed in a vehicle interior in a range of a vertical distance Elh of 0.1 to 0.4 m downward from a horizontal plane including a lower surface of a headrest of a front seat, and a ventilation resistance AFR and a vertical distance Elh satisfy a relationship of 210<AFR+10 / Elh<3020, wherein the unit of the ventilation resistance AFR is Ns / m 3 , the unit of the vertical distance Elh is m, The sound absorbing portion is thicker than other regions of the main body, and the air flow resistance AFR satisfying the above relationship is set by the difference in thickness between the sound absorbing portion and other regions of the main body.

2. The vehicle sound absorbing material according to claim 1, wherein: The sound absorbing portion includes a non-air-permeable material stacked on the side of the fiber material opposite to the skin material.

3. The vehicle sound absorbing material according to claim 1, wherein: The sound absorbing portion includes a foam layer having a thickness of 5 mm to 15 mm between the fiber material and the skin material.

4. The vehicle sound absorbing material according to claim 1, wherein: The sound absorption rate of the sound absorbing part above 1000 Hz is higher than the sound absorption rate below 1000 Hz.

5. The vehicle sound absorbing material according to claim 1, wherein: At least the main body portion is assembled so as to constitute a part of the vehicle interior.

6. The vehicle sound absorbing material according to claim 1, wherein: The thickness of the lower portion of the sound absorbing part is set to be thicker than the thickness of the upper portion.

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