Vehicle exterior noise reduction structure

Abstract

Provided is a vehicle external noise reduction structure capable of reducing external noise of a vehicle. 【Solution means】The vehicle external noise reduction structure 100 of the vehicle 10 includes reflection members 110, 120, 130, 140 and sound absorption members 112, 122, 132, 142. The reflection members 110, 120, 130, 140 are provided so as to face either the vehicle front direction or the vehicle rear direction with respect to the wheels 31 to 34 of the vehicle 10, and reflect the radiated sound emitted from the tires of the wheels 31 to 34, with the front wheels reflected to the front side and the rear wheels reflected to the rear side. The sound absorption members 112, 122, 132, 142 absorb at least one of the radiated sound and the reflected sound reflected by the reflection members. And it is a method of reducing external noise by separating the sounds radiated from the front and rear wheels in the front and rear directions.

Description

Technical Field

[0001] The present invention relates to a structure for reducing vehicle exterior noise.

Background Art

[0002] Conventionally, there is a structure for reducing vehicle exterior noise described in Patent Document 1 below. The structure for reducing vehicle exterior noise described in Patent Document 1 includes a groove-shaped portion having a side wall portion extending in the front-rear direction of the vehicle and a side wall portion located inside in the vehicle width direction. The side wall portion includes a sound absorption portion formed of a sound absorption member.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the structure for reducing vehicle exterior noise described in Patent Document 1, there is room for improvement regarding the effect of reducing vehicle exterior noise generated due to the rolling of the tire on the road surface.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a structure for reducing vehicle exterior noise that can reduce vehicle exterior noise.

Means for Solving the Problems

[0006] The structure for reducing vehicle exterior noise that solves the above problems includes a front-wheel reflection member and a first sound absorption member. The front-wheel reflection member is provided facing the rear of the vehicle with respect to the front wheels of the vehicle, and reflects the radiated sound generated from the ground contact surface of the front-wheel tire. The first sound absorption member absorbs at least one of the radiated sound and the reflected sound reflected by the front-wheel reflection member.

[0007] Another vehicle exterior noise reduction structure for solving the above problems includes a rear wheel reflecting member and a third sound absorbing member. The rear wheel reflecting member is provided facing the front direction of the vehicle with respect to the rear wheels of the vehicle, and reflects the radiated sound generated from the ground contact surface of the rear wheel tires. The third sound absorbing member absorbs at least one of the radiated sound and the reflected sound reflected by the rear wheel reflecting member.

[0008] According to this configuration, the radiated sound generated from the ground contact surface of the tire can be reflected forward or backward of the vehicle by the front wheel reflecting member or the rear wheel reflecting member. Further, the radiated sound or the reflected sound is absorbed by the first sound absorbing member or the third sound absorbing member. Therefore, it is possible to reduce the vehicle exterior noise.

Effect of the Invention

[0009] According to the vehicle exterior noise reduction structure of the present invention, it is possible to reduce the vehicle exterior noise.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Mode for Carrying Out the Invention

[0011] Hereinafter, the first to seventh embodiments of the vehicle exterior noise reduction structure will be described with reference to the drawings. For ease of understanding the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicate descriptions are omitted.

[0012] <First Embodiment> Prior to describing the vehicle exterior noise reduction structure of the first embodiment, the principle of the vehicle exterior noise reduction structure of this embodiment will be described.

[0013] (Explanation of the principle) The inventors of the present application experimentally measured the noise radiated from each of the front and rear tires of the vehicle by using a so-called indoor pass-by test for measuring the passing noise of the vehicle indoors. FIGS. 1 and 2 show the experimental results obtained by the inventors.

[0014] FIG. 1 maps the vehicle exterior noise when the respective tires of the right front wheel 31, left front wheel 32, right rear wheel 33, and left rear wheel 34 of the vehicle 10 are rotated on a chassis dynamo device and measured by microphone devices M1 to M 13 In FIG. 1, with the position O set in front of the vehicle 10 as the origin (0, 0), the axis parallel to the front-rear direction of the vehicle 10 is indicated by the x-axis, and the axis parallel to the left-right direction of the vehicle 10 is indicated by the y-axis. The positive direction of the x-axis is set to the rear direction of the vehicle 10, and the negative direction of the x-axis is set to the front direction of the vehicle 10. The positive direction of the y-axis is set to the right direction of the vehicle 10, and the negative direction of the y-axis is set to the left direction of the vehicle 10.

[0015] As shown in FIG. 1, the microphone devices M1 to M 13They are arranged side by side on the axis m10. The axis m10 is a line parallel to the x-axis and separated from the center of the vehicle 10 by a predetermined distance L in the y-axis direction. Note that the distance L is set to 7.5 m by regulations. Also, the microphone devices M1 to M 13 are respectively arranged at the positions shown in FIG. 1. Also, the center positions Pt1 to Pt4 of the wheels 31 to 34 of the vehicle 10 are as shown in FIG. 1.

[0016] In FIG. 1, from the tire of the right front wheel 31 to the microphone devices M1 to M 13 The intensity of the noise at the microphone positions radiated in the direction is represented by vectors Va1 to Va 13 shown. Each of the vectors Va1 to Va 13 The direction of the arrow indicates the direction of the noise radiated from the tire of the right front wheel 31. Each of the vectors Va1 to Va 13 The length of the arrow indicates the intensity of the noise at the microphone position radiated from the tire of the right front wheel 31. In FIG. 1, similarly, the intensity of the noise radiated from the tire of the left front wheel 32 is represented by vectors Vb1 to Vb 13 shown, the intensity of the noise radiated from the tire of the right rear wheel 33 is represented by vectors Vc1 to Vc 13 shown, and the intensity of the noise radiated from the tire of the left rear wheel 34 is represented by vectors Vd1 to Vd 13 shown. Note that the unit of the noise intensity is [W / m 2 .

[0017] Figure 2 graphs the exterior noise of the vehicle obtained from the experiment shown in Figure 1. In Figure 2, the position [m] on the axis m10 is taken on the horizontal axis, and the noise level [dB] of the tires of each of the wheels 31 to 34 is taken on the vertical axis, and their relationship is shown in a graph. In Figure 2, the solid line L1 indicates the noise level when all of the tires of each of the wheels 31 to 34 are rotated, the dashed-dotted line L2 indicates the noise level when only the tire of the right front wheel 31 is rotated, and the double-dashed-dotted line L3 indicates the noise level when only the tire of the left front wheel 32 is rotated. Also, the short dashed line L4 indicates the noise level when only the tire of the right rear wheel 33 is rotated, and the long dashed line L5 indicates the noise level when only the tire of the left rear wheel 34 is rotated. Hereinafter, the noise when all of the tires of each of the wheels 31 to 34 indicated by the solid line L1 in Figure 2 are rotated is referred to as "exterior noise during all-tire running".

[0018] As shown in FIGS. 1 and 2, the intensity [W / m 2 of the noise at the microphone position radiated from each of the tires of the wheels 31 to 34 and the noise level [dB] are distributed in the front-rear direction of the microphone device installed beside the vehicle 10. For example, as shown by the dashed-dotted line L2 in FIG. 2, the noise level of the tire of the front wheel 31 reaches a maximum value at the position of "+1.3 m". Also, as shown by the short dashed line L4 in FIG. 2, the noise level of the tire of the rear wheel 33 reaches a maximum value at the position of "+6.0 m". Also, as shown by the solid line L1 in FIG. 2, the noise level of the exterior noise during all-tire running reaches a maximum at the position of "+3 to 5 m".

[0019] As shown in FIGS. 1 and 2, when the microphone positions where the intensity of the noise radiated from the tires of the front wheels 31 and 32 is maximum and the microphone positions where the intensity of the noise radiated from the tires of the rear wheels 33 and 34 is maximum are close to each other, there is a possibility that these four noises reinforce each other, and this is considered to be a factor increasing the exterior noise level during all-tire running. Therefore, if the noise radiated from the tires of the front wheels 31 and 32 and the noise radiated from the tires of the rear wheels 33 and 34 can be separated from each other in terms of distance, the exterior noise during all-tire running can be reduced.

[0020] Next, the vehicle exterior noise reduction structure of the first embodiment configured based on this principle will be described.

[0021] (Configuration of Vehicle and Vehicle Exterior Noise Reduction Structure) FIG. 3 is a side view showing the left side structure of the vehicle 10 of the first embodiment. Further, FIG. 4 is a plan view showing the planar structure of the vehicle 10 of the first embodiment. Hereinafter, the vehicle front direction is indicated by the symbol FR, the vehicle rear direction is indicated by the symbol BA, the vehicle right direction is indicated by the symbol RH, and the vehicle left direction is indicated by the symbol LH. Also, the vehicle front-rear direction is indicated by the symbol FB, and the vehicle left-right direction is indicated by the symbol RL.

[0022] As shown in FIGS. 3 and 4, the vehicle 10 includes a vehicle body 20 and wheels 31 to 34. The wheels 31 to 34 are connected to an axle (not shown) and are rotatably supported with respect to the vehicle body 20 via the axle.

[0023] The vehicle exterior noise reduction structure 100 of the vehicle 10 in the present embodiment includes front-wheel reflection members 110 and 120 and rear-wheel reflection members 130 and 140.

[0024] The front-wheel reflection member 110 is provided at a portion of the bottom surface of the vehicle body 20 that corresponds to the vehicle rear direction BA of the right front wheel 31. FIG. 5 shows a cross-sectional structure along the line V-V in FIG. 4. FIG. 6 shows a cross-sectional structure along the line VI-VI in FIG. 4. As shown in FIGS. 3 to 6, the front-wheel reflection member 110 includes a main body member 111 and a sound absorption member 112.

[0025] The body member 111 is made of a material capable of reflecting the noise generated from the tire of the right front wheel 31, for example, resin. Further, the front wheel reflection member 110 is more effective when formed of a material having not only a sound reflection function but also a sound absorption function. As a material having a sound reflection function and a sound absorption function, for example, a glass fiber non-woven fabric can be used. As the glass fiber non-woven fabric, for example, the product name "Sekiso Acoustic Board (SAB)" manufactured by Sekiso Co., Ltd., which is a sound absorption board material obtained by blending glass fiber with olefin fiber as a binder, can be used. As shown in FIGS. 3 and 4, the body member 111 may include an opposing portion 111a and a hanging wall portion 111b for further enhancing the effect.

[0026] The opposing portion 111a is a portion of the body member 111 that is arranged to face the tire of the right front wheel 31 in the vehicle rearward direction BA. The opposing portion 111a is formed to extend parallel to the vehicle left-right direction RL. As shown in FIG. 5, the cross-sectional shape of the opposing portion 111a orthogonal to the vehicle left-right direction RL is V-shaped. The opposing portion 111a has an opening that opens toward the direction of the contact surface of the tire of the right front wheel 31.

[0027] The hanging wall portion 111b is a portion of the body member 111 that is formed to be bent from the end of the opposing portion 111a in the vehicle leftward direction LH toward the vehicle frontward direction FR. As shown in FIG. 6, the cross-sectional structure of the hanging wall portion 111b is V-shaped similar to the opposing portion 111a. The hanging wall portion 111b has an opening that opens toward the left side portion of the tire of the right front wheel 31.

[0028] Note that the rear wheel reflection member 130 may have a function as a spats capable of reducing the resistance of the air flowing into the tire of the right rear wheel 33.

[0029] As shown in FIGS. 5 and 6, the sound absorbing member 112 is provided inside the opposing portion 111a and the hanging wall portion 111b of the main body member 111. The sound absorbing member 112 can be made of a material capable of absorbing noise generated from the tire contact surface of the right front wheel 31, for example, a material made of polyester fiber. As the polyester fiber, the product name "Sekiso Acoustic Fiber (SAF)" manufactured by Sekiso Co., Ltd. can be used.

[0030] As shown in FIGS. 3 and 4, the front wheel reflecting member 120 is provided at a portion of the bottom surface of the vehicle body 20 that corresponds to the rear direction BA of the vehicle of the left front wheel 32. The front wheel reflecting member 120 includes a main body member 121 and a sound absorbing member 122. The main body member 121 includes an opposing portion 121a disposed so as to face the tire contact surface of the left front wheel 32 in the rear direction BA of the vehicle, and a hanging wall portion 121b formed so as to be bent from the end portion of the opposing portion 121a in the right hand direction RH of the vehicle toward the front direction FR of the vehicle. Since the configurations of the main body member 121 and the sound absorbing member 122 are the same as or similar to the configurations of the main body member 111 and the sound absorbing member 112 of the front wheel reflecting member 110, the description of their configurations is omitted.

[0031] The rear wheel reflecting member 130 is provided at a portion of the bottom surface of the vehicle body 20 that corresponds to the front direction FR of the vehicle of the right rear wheel 33. The rear wheel reflecting member 130 includes a main body member 131 and a sound absorbing member 132. The main body member 131 includes an opposing portion 131a disposed so as to face the tire of the right rear wheel 33 in the front direction FR of the vehicle, and a hanging wall portion 131b formed so as to be bent from the end portion of the opposing portion 131a in the left hand direction LH of the vehicle toward the rear direction BA of the vehicle. Since the configurations of the main body member 131 and the sound absorbing member 132 are the same as or similar to the configurations of the main body member 111 and the sound absorbing member 112 of the front wheel reflecting member 110, the description of their configurations is omitted.

[0032] At a portion corresponding to the vehicle front direction FR of the left rear wheel 34 on the bottom surface of the vehicle body 20, a rear wheel reflecting member 140 is provided. The rear wheel reflecting member 140 includes a main body member 141 and a sound absorbing member 142. The main body member 141 includes an opposing portion 141a disposed so as to face the tire of the left rear wheel 34 in the vehicle front direction FR, and a hanging wall portion 141b formed so as to be bent from the end of the opposing portion 141a in the vehicle right direction RH toward the vehicle rear direction BA. Since the configurations of the main body member 141 and the sound absorbing member 142 of the rear wheel reflecting member 140 are the same as or similar to the configurations of the main body member 111 and the sound absorbing member 112 of the front wheel reflecting member 110, the description of their configurations is omitted.

[0033] (Operation and Effect of the Vehicle Exterior Noise Reduction Structure of the First Embodiment) As shown in FIG. 7, when the tire 200 rolls, pattern noise in the range of 1 kHz to 2 kHz is generated from the front and rear of the contact portion 230 between the tire 200 and the ground 210, and this forms the vehicle exterior noise. In the case of a single tire, the tire noise spreads in the vehicle front-rear direction FB from the contact portion 230 and then spreads in the vehicle left-right direction RL as it moves away from the ground contact surface. When the tire 200 is mounted on the vehicle together with the wheel, the tire noise basically forms a gourd-shaped spread in the front-rear direction first and then in the 45° diagonal direction from the middle, similar to that of a single tire. However, the tire noise may form different spreads depending on the vehicle body and accessories.

[0034] Therefore, as described above, the vehicle exterior noise reduction structure 100 of the vehicle 10 in the present embodiment includes the reflecting members 110, 120, 130, 140 and the sound absorbing members 112, 122, 132, 142. The reflecting members 110, 120, 130, 140 are provided so as to face either the vehicle front direction FR or the vehicle rear direction BA with respect to the wheels 31 to 34, and reflect the radiated sound radiated from the tires of the wheels 31 to 34. The sound absorbing members 112, 122, 132, 142 are provided inside the reflecting members 110, 120, 130, 140 and absorb the radiated sound. In the present embodiment, the sound absorbing members 112, 122 are examples of the first sound absorbing member, and the sound absorbing members 132, 142 are examples of the third sound absorbing member.

[0035] In the vehicle exterior noise reduction structure 100 of this embodiment, as shown by the dashed arrow n11 in FIG. 4, the noise generated from the tire of the right front wheel 31 is reflected by the front wheel reflection member 110 disposed in the vehicle rearward direction BA of the right front wheel 31 and concentrated in the vehicle forward direction FR. Further, a part of the noise generated from the tire of the right front wheel 31 is absorbed by the sound absorption member 112 provided on the front wheel reflection member 110. Similarly, with respect to the noise generated from the tire of the left front wheel 32, as shown by the dashed arrow n12 in FIGS. 3 and 4, it can be concentrated in the vehicle forward direction FR by the front wheel reflection member 120 and absorbed by the sound absorption member 122.

[0036] Also, the noise generated from the tire of the right rear wheel 33 is reflected by the rear wheel reflection member 130 disposed in the vehicle forward direction FR of the right rear wheel 33 and concentrated in the vehicle rearward direction BA, as shown by the dashed arrow n13 in FIG. 4. Further, a part of the noise generated from the tire of the right rear wheel 33 is absorbed by the sound absorption member 132 provided on the rear wheel reflection member 130. Similarly, with respect to the noise generated from the tire of the left rear wheel 34, it can be concentrated in the vehicle rearward direction BA by the rear wheel reflection member 130 and absorbed by the sound absorption member 142.

[0037] As described above, due to the tire noise of the front wheels 31, 32 diffusing in the vehicle forward direction FR and the tire noise of the rear wheels 33, 34 diffusing in the vehicle rearward direction BA, the position where the tire noise of the front wheels 31, 32 is maximum shifts in the vehicle forward direction FR, and the position where the tire noise of the rear wheels 33, 34 is maximum shifts in the vehicle rearward direction BA. That is, since the position where the tire noise of the front wheels 31, 32 is maximum and the position where the tire noise of the rear wheels 33, 34 is maximum can be separated, the vehicle exterior noise during four-wheel driving can be reduced as a result.

[0038] FIG. 8 shows the results of experimentally measuring the external noise of the vehicle 10 provided with the external noise reduction structure 100 of the present embodiment. In FIG. 8, the experimental results when all of the front wheel reflecting members 110 and 120 and the rear wheel reflecting members 130 and 140 are provided on the vehicle 10 are shown by the solid line L10, and the experimental results when only the front wheel reflecting members 110 and 120 are provided on the vehicle 10 are shown by the alternate long and short dash line L11, and the experimental results when only the rear wheel reflecting members 130 and 140 are provided on the vehicle 10 are shown by the long and short dash double dot line L12.

[0039] As shown by the solid line L10 in FIG. 8, when all of the front wheel reflecting members 110 and 120 and the rear wheel reflecting members 130 and 140 are provided on the vehicle 10 as in the external noise reduction structure 100 of the present embodiment, the external noise level can be suppressed to 69 dB or less. Therefore, compared with the vehicle 10 of the reference example shown in FIG. 2, it is possible to reduce the external noise by about 2 dB.

[0040] Note that, as shown by the alternate long and short dash line L11 and the long and short dash double dot line L12 in FIG. 8, even when only the front wheel reflecting members 110 and 120 are provided on the vehicle 10, or when only the rear wheel reflecting members 130 and 140 are provided on the vehicle 10, the external noise level can be suppressed to 70 dB or less, and it is possible to reduce the external noise by about 1 dB. This is because, for example, even when only the front wheel reflecting members 110 and 120 are provided on the vehicle 10, the position where the tire noise of the front wheels 31 and 32 is maximum can be shifted forward in the vehicle direction FR, so that the position where the tire noise of the front wheels 31 and 32 is maximum and the position where the tire noise of the rear wheels 33 and 34 is maximum can be separated. The same applies when only the rear wheel reflecting members 130 and 140 are provided on the vehicle 10.

[0041] In addition, the front-wheel reflection members 110 and 120 include opposing portions 111a and 121a provided to face the front wheels 31 and 32 in the vehicle rearward direction BA, and hanging wall portions 111b and 121b formed to extend in the vehicle forward direction FR along the respective side surfaces of the front wheels 31 and 32 from the opposing portions 111a and 121a. In the present embodiment, the opposing portions 111a and 121a are examples of the first opposing portion, and the hanging wall portions 111b and 121b are examples of the first hanging wall portion. Further, the rear-wheel reflection members 130 and 140 include opposing portions 131a and 141a provided to face the rear wheels 33 and 34 in the vehicle forward direction FR, and hanging wall portions 131b and 141b formed to extend in the vehicle rearward direction BA along the respective side surfaces of the rear wheels 33 and 34 from the opposing portions 131a and 141a. In the present embodiment, the opposing portions 131a and 141a are examples of the second opposing portion, and the hanging wall portions 131b and 141b are examples of the second hanging wall portion.

[0042] According to this configuration, the radiated sound emitted from each tire of the front wheels 31 and 32 can be more effectively reflected in the vehicle forward direction FR by the front-wheel reflection members 110 and 120, and the radiated sound emitted from each tire of the rear wheels 33 and 34 can be more effectively reflected in the vehicle rearward direction BA by the rear-wheel reflection members 130 and 140. Therefore, it is possible to more accurately reduce the noise level outside the vehicle. Here, when only the reflection member (such as 110) is used, the noise on the side where the tire noise is reflected simply increases because the tire noise is merely reflected. When a sound-absorbing material (such as 112) is placed in the reflection member, the noise can be gently pushed back, and there is an effect of inverting the noise without increasing the sound on the opposite side.

[0043] (Modification example) Next, a modification example of the vehicle exterior noise reduction structure 100 of the first embodiment will be described.

[0044] The vehicle exterior noise reduction structure 100 of this modification example, as shown in FIGS. 9 and 10, only includes the front wheel reflection members 110 and 120, and is different from the vehicle exterior noise reduction structure 100 of the above embodiment in that it does not include the rear wheel reflection members 130 and 140. The front wheel reflection member 110 is fixed to the lower part of the fender liner at the portion of the right front wheel 31's tire in the vehicle rear direction BA in the right front fender liner of the vehicle 10. The front wheel reflection member 120 is fixed to the lower part of the fender liner at the portion of the left front wheel 32's tire in the vehicle rear direction BA in the left front fender liner. The front wheel reflection members 110 and 120 are, for example, mud guards, and are formed of a plate-like material capable of reflecting and absorbing the radiated sound radiated from the tires of the front wheels 31 and 32. As such a material, for example, a combination of a glass fiber non-woven fabric such as SAB and a polyester fiber such as SAF can be used.

[0045] Even with such a configuration, since the positions where the tire noise of the front wheels 31 and 32 is maximized can be shifted forward in the vehicle direction FR, it is possible to reduce the noise level outside the vehicle.

[0046] <Second Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 in the second embodiment will be described. Hereinafter, the description will focus on the differences from the vehicle exterior noise reduction structure 100 of the above embodiment.

[0047] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIGS. 11 and 12, the vehicle exterior noise reduction structure 100 of this embodiment is provided in the fender liners 41 to 44 respectively.

[0048] The left front fender liner 42 is composed of a reflection member 420 and a sound absorption member 421.

[0049] The reflecting member 420 is provided at a portion of the fender liner 42 that corresponds to the rearward direction BA of the vehicle of the left front wheel 32. The reflecting member 420 is formed of a material capable of softly reflecting the radiated sound radiated from the tire contact surface of the left front wheel 32 while absorbing it, for example, a glass fiber non-woven fabric such as SAB.

[0050] The sound absorbing member 421 is provided at a portion of the fender liner 42 that corresponds to the upper side of the left front wheel 32 and the forward direction FR of the vehicle. The sound absorbing member 421 is formed of a material capable of absorbing the reflected sound reflected by the reflecting member 420, for example, a polyester fiber such as SAF.

[0051] The right front fender liner 41 is similarly constituted by a reflecting member 410 and a sound absorbing member 411. Since the configurations of the reflecting member 410 and the sound absorbing member 411 are the same as or similar to the configurations of the reflecting member 420 and the sound absorbing member 421 of the left front fender liner 42, respectively, detailed descriptions thereof are omitted.

[0052] The left rear fender liner 44 is constituted by a reflecting member 440 and a sound absorbing member 441. The reflecting member 440 is provided at a portion of the fender liner 44 that corresponds to the forward direction FR of the vehicle of the left rear wheel 34. The sound absorbing member 441 is provided at a portion of the fender liner 44 that corresponds to the upper side of the left rear wheel 34 and the rearward direction BA of the vehicle. As the materials of the reflecting member 440 and the sound absorbing member 441, respectively, the same or similar materials as those of the reflecting member 420 and the sound absorbing member 421 of the left front fender liner 42 can be used.

[0053] The right rear fender liner 43 is similarly constituted by a reflecting member 430 and a sound absorbing member 431. Since the configurations of the reflecting member 430 and the sound absorbing member 431 are the same as or similar to the configurations of the reflecting member 440 and the sound absorbing member 441 of the left rear fender liner 44, respectively, detailed descriptions thereof are omitted.

[0054] (Operation and Effect of the Vehicle Exterior Noise Reduction Structure of the Second Embodiment) As described above, the vehicle exterior noise reduction structure 100 of the vehicle 10 according to this embodiment includes reflection members 410, 420, 430, 440 and sound absorption members 411, 421, 431, 441. The reflection members 410, 420 are provided in the vehicle rear direction BA so as to face the front wheels 31, 32, and the reflection members 430, 440 are provided in the vehicle front direction FR so as to face the rear wheels 33, 34, and reflect the radiated sound radiated from the tires of the wheels 31 to 34 forward and backward respectively. The sound absorption members 411, 421, 431, 441 are provided on the opposite sides of the reflection members 410, 420, 430, 440 and absorb the reflected sound. The sound absorption members 411, 421 are an example of the first sound absorption member, and the sound absorption members 431, 441 are an example of the third sound absorption member.

[0055] Even with this configuration, it is possible to achieve the same or similar operations and effects as the vehicle exterior noise reduction structure 100 of the first embodiment.

[0056] <Third Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the third embodiment will be described. Hereinafter, the description will focus on the differences from the vehicle exterior noise reduction structure 100 of each of the above embodiments.

[0057] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIGS. 13 and 14, openings OR and OL as boarding and alighting openings are respectively provided in the right side surface portion and the left side surface portion of the vehicle body 20. The vehicle body 20 includes a pair of left and right rocker portions 21, 22 formed to extend in the vehicle front-rear direction FB along the lower sides of the openings OR and OL respectively. The rocker portion 21 reinforces the lower portion of the opening OR while being joined to the floor panel, and the rocker portion 22 reinforces the lower portion of the opening OL while being joined to the flow panel.

[0058] FIG. 15 is a cross-sectional view showing a cross-sectional structure along line XV-XV of FIG. 14. As shown in FIG. 15, the vehicle exterior noise reduction structure 100 of the present embodiment includes a sound absorbing member 150 disposed adjacent to the lower surface of the rocker portion 21. The cross-sectional shape of the sound absorbing member 150 perpendicular to the vehicle front-rear direction FB is a shape close to a concave shape. As shown in FIGS. 13 and 14, the sound absorbing member 150 is formed to extend in the vehicle front-rear direction FB along the lower surface of the rocker portion 21. The sound absorbing member 150 is made of a material capable of absorbing noise radiated from each of the tires of the wheels 31 to 34, for example, a sound absorbing plate material such as SAB + SAF and polyester fibers.

[0059] The vehicle exterior noise reduction structure 100 further includes a sound absorbing member 160 disposed adjacent to the lower surface of the rocker portion 22. Since the structure of the sound absorbing member 160 is the same as or similar to that of the sound absorbing member 150, its description is omitted.

[0060] (Function and Effect of Vehicle Exterior Noise Reduction Structure of the Third Embodiment) As described above, the vehicle exterior noise reduction structure 100 of the vehicle 10 of the present embodiment includes the sound absorbing members 150 and 160 provided adjacent to the lower surfaces of the rocker portions 21 and 22 of the vehicle. The sound absorbing member 150 absorbs the radiated sound radiated from the right front wheel 31 in the vehicle rear direction BA and the radiated sound radiated from the right rear wheel 33 in the vehicle front direction FR. The sound absorbing member 160 absorbs the radiated sound radiated from the left front wheel 32 in the vehicle rear direction BA and the radiated sound radiated from the left rear wheel 34 in the vehicle front direction FR. In the present embodiment, the sound absorbing members 150 and 160 are an example of the fifth sound absorbing member.

[0061] According to this configuration, the radiated sound radiated from the wheels 31 to 34 can be absorbed by the sound absorbing members 150 and 160, the noise in front of the rear wheels and behind the front wheels is reduced, and the main directions of the noise of the front and rear wheels are separated front and rear, so that the vehicle exterior noise level can be further reduced.

[0062] <Fourth Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the fourth embodiment will be described. Hereinafter, the description will focus on the differences from the vehicle exterior noise reduction structure 100 of each of the above embodiments.

[0063] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIGS. 16 and 17, the vehicle exterior noise reduction structure 100 of the present embodiment includes sound absorption boxes 170 and 180. In the present embodiment, the sound absorption box 170 is an example of the second sound absorption member, and the sound absorption box 180 is an example of the fourth sound absorption member.

[0064] The sound absorption box 170 is provided at a portion corresponding to the lower part of the center of the front end of the vehicle 10 in front of the front wheel tire. As shown in FIG. 18, the sound absorption box 170 is a cylindrical body formed to extend in the vehicle left - right direction RL. The sound absorption box 170 has an opening 171 at its center. As shown in FIG. 17, the opening 171 is located on the vehicle body center line m20. The opening 171 is formed to open toward the front wheel direction in the vehicle rear direction BA.

[0065] As shown in FIGS. 16 and 17, the sound absorption box 180 is provided at a portion corresponding to the lower part of the center of the rear end of the vehicle 10 behind the rear wheel tire. The sound absorption box 180 has the same or a similar structure as the sound absorption box 170. However, the opening 181 of the sound absorption box 180 is formed to open toward the rear wheel direction in the vehicle front direction FR.

[0066] Note that internal sound absorption members such as SAF that can absorb noise may be packed inside each of the sound absorption boxes 170 and 180.

[0067] (Operation and Effect of Vehicle Exterior Noise Reduction Structure of Fourth Embodiment) In the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the present embodiment, as shown by arrows n21 and n22 in FIG. 17, the reflected sound reflected from the portions of the front wheels 31 and 32 in the vehicle rearward direction BA is collected inside the sound absorption box 170 through the openings 171, and thus is absorbed or silenced. Similarly, as shown by arrows n23 and n24 in FIG. 17, the reflected sound reflected from the portions of the rear wheels 33 and 34 in the vehicle forward direction FR is collected inside the sound absorption box 180 through the openings 181, and thus is absorbed or silenced. Thereby, since the reflected sound can be suppressed from diffusing outside the vehicle, it is possible to more accurately reduce the vehicle exterior noise level.

[0068] (Modification example) Next, a modification example of the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the fourth embodiment will be described.

[0069] In this modification example, as shown in FIG. 19, openings 172 and 173 are formed in the sound absorption box 170. As shown in FIG. 20, the openings 172 and 173 are respectively open toward the right front wheel 31 and the left front wheel 32.

[0070] Similarly, as shown in FIG. 20, openings 182 and 183 are formed in the sound absorption box 180. The openings 182 and 183 are respectively open toward the right rear wheel 33 and the left rear wheel 34.

[0071] According to this configuration, as shown by arrows n25 and n26 in FIG. 20, the radiated sound radiated from the respective tires of the front wheels 31 and 32 toward the vehicle forward direction FR is collected inside the sound absorption box 170 through the openings 172 and 173, and thus is absorbed or silenced. Similarly, as shown by arrows n27 and n28 in FIG. 20, the radiated sound radiated from the respective tires of the rear wheels 33 and 34 toward the vehicle rearward direction BA is collected inside the sound absorption box 180 through the openings 182 and 183, and thus is absorbed or silenced. Thereby, since the radiated sound can be suppressed from diffusing outside the vehicle, it is possible to more accurately reduce the vehicle exterior noise level.

[0072] <Fifth Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the fifth embodiment will be described. Hereinafter, the description will focus on the differences from the vehicle exterior noise reduction structure 100 of each of the above embodiments.

[0073] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIGS. 21 and 22, the vehicle exterior noise reduction structure 100 of the present embodiment includes front wheel fairing structures 310 and 320, and rear wheel fairing structures 330 and 340.

[0074] The front wheel fairing structure 320 is provided at a portion corresponding to the front of the left front wheel 32 on the bottom surface of the vehicle body 20. The front wheel fairing structure 320 is formed of a material capable of absorbing noise radiated from the tire of the left front wheel 32 in the vehicle front direction FR, for example, a sound absorbing plate material such as SAB + SAF and polyester fibers. The front wheel fairing structures 310 and the rear wheel fairing structures 330 and 340 also have the same or similar shapes as the front wheel fairing structure 320.

[0075] (Operation and Effect of Vehicle Exterior Noise Reduction Structure of Fifth Embodiment) In the vehicle exterior noise reduction structure 100 of the present embodiment, since the front wheel fairing structures 310 and 320 are formed of a noise-absorbing material, acoustically, it is possible to widen the passage through which the radiated sound radiated from the front wheels 31 and 32 can pass, as compared with the case where the front wheel fairing structures 310 and 320 are not provided. As a result, the radiated sound radiated from the front wheels 31 and 32 easily diffuses in the vehicle front direction FR through the front wheel fairing structures 310 and 320. Similarly, since the rear wheel fairing structures 330 and 340 are formed of a noise-absorbing material, the radiated sound radiated from the rear wheels 33 and 34 easily diffuses in the vehicle rear direction BA through the rear wheel fairing structures 330 and 340. Thereby, for example, it is possible to reduce the sound in the wheelhouse, and since the spread of the tire noise of the front and rear wheels is separated front and rear, it is possible to more accurately reduce the vehicle exterior noise.

[0076] (Modification Example) Next, a modification example of the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the fifth embodiment will be described.

[0077] In the vehicle exterior noise reduction structure 100 of this modification example, as shown in FIGS. 23 and 24, the front wheel fairing structure 320 is configured such that the portion on the vehicle front direction FR side of the left front fender liner and the portion on the bottom surface of the vehicle body 20 corresponding to the front of the left front wheel 32 are formed in a net shape or a lattice shape. The front wheel fairing structure 310 also has the same or a similar shape.

[0078] The rear wheel fairing structure 340 is configured such that the portion on the vehicle rear direction BA of the left rear wheel 34 in the rear bumper 45 of the vehicle 10 is formed in a net shape or a lattice shape. The rear wheel fairing structure 330 also has the same or a similar shape.

[0079] According to such a configuration, the radiated sound radiated from the front wheels 31, 32 easily diffuses in the vehicle front direction FR through the front wheel fairing structures 310, 320 and passes through the front grille of the vehicle. Further, the radiated sound radiated from the rear wheels 33, 34 easily diffuses in the vehicle rear direction BA through the rear wheel fairing structures 330, 340. Thereby, for example, it is possible to reduce the sound inside the wheelhouse, and since the spread of the tire noise of the front and rear wheels is separated front and rear, it is possible to more accurately reduce the vehicle exterior noise.

[0080] <Sixth Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 according to the sixth embodiment will be described. Hereinafter, the description will be centered on the differences from the vehicle exterior noise reduction structure 100 of each of the above embodiments.

[0081] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIGS. 25 and 26, the vehicle exterior noise reduction structure 100 of the present embodiment includes sound absorbing members 710, 720, 730, 740 respectively attached to the wheels 31 to 34.

[0082] The sound absorption member 720 is used as the wheel cap of the left front wheel 32. The sound absorption member 720 is formed of a material capable of absorbing sound, such as a glass fiber impregnated sound absorption plate material such as SAB, a polyester fiber such as SAF, and combinations thereof. The sound absorption members 710, 730, and 740 are formed of the same or similar materials as the sound absorption member 720, and are used as the wheel caps of the right front wheel 31, the wheel cap of the right rear wheel 33, and the wheel cap of the left rear wheel 34, respectively. In the present embodiment, the sound absorption members 710, 720, 730, and 740 are an example of the sixth sound absorption member.

[0083] (Function and Effect of the Vehicle Exterior Noise Reduction Structure of the Sixth Embodiment) In the vehicle exterior noise reduction structure 100 of the present embodiment, for example, the reflected sound reflected at the portion on the vehicle rear direction BA side in the wheel house of the left front wheel 32 and the tire radiation sound flowing into the wheel house are absorbed by the sound absorption member 720, whereby the sound pressure in the wheel house of the left front wheel 32 can be reduced. Similarly, the sound pressure of each of the wheel houses of the right front wheel 31, the right rear wheel 33, and the left rear wheel 34 can also be reduced, whereby it is possible to more accurately reduce the vehicle exterior noise.

[0084] (First Modification Example) Next, a first modification example of the vehicle exterior noise reduction structure 100 of the vehicle 10 of the sixth embodiment will be described.

[0085] In the vehicle exterior noise reduction structure 100 of this modification example, as shown in FIGS. 27 and 28, the sound absorption member 720 is provided on the tire side of the inner panel 52 on the vehicle right direction RH side of the wheel house of the left front wheel 32. Similarly, the sound absorption member 710 is provided on the tire side of the inner panel 51 on the vehicle left direction LH side of the wheel house of the right front wheel 31. Further, the sound absorption member 730 is provided on the tire side of the inner panel 53 on the vehicle left direction LH side of the wheel house of the right rear wheel 33. Furthermore, the sound absorption member 740 is provided on the tire side of the inner panel 54 on the vehicle right direction RH side of the wheel house of the left rear wheel 34.

[0086] Even with such a configuration, it is possible to obtain the same or similar actions and effects as those of the vehicle exterior noise reduction structure 100 of the sixth embodiment.

[0087] (Second Modification Example) Next, a second modification example of the vehicle exterior noise reduction structure 100 of the vehicle 10 of the sixth embodiment will be described.

[0088] In the vehicle exterior noise reduction structure 100 of this modification example, as shown in FIGS. 29 and 30, sound absorption members 710, 720, 730, and 740 are respectively provided inside the tire wheels of the wheels 31 to 34.

[0089] Even with such a configuration, it is possible to obtain the same or similar actions and effects as those of the vehicle exterior noise reduction structure 100 of the sixth embodiment.

[0090] <Seventh Embodiment> Next, the vehicle exterior noise reduction structure 100 of the vehicle 10 of the seventh embodiment will be described. Hereinafter, the description will focus on the differences from the vehicle exterior noise reduction structure 100 of each of the above embodiments.

[0091] (Configuration of Vehicle Exterior Noise Reduction Structure) As shown in FIG. 31, the vehicle exterior noise reduction structure 100 of the present embodiment includes scooping members 520, 540 and sound absorption boxes 620, 640.

[0092] The scooping member 520 is formed so as to project from the bottom surface of the vehicle body 20 toward the ground 210 in the vehicle rear direction BA of the left front wheel 32. The scooping member 520 is made of a material capable of guiding the radiated sound radiated from the tire of the left front wheel 32 toward the vehicle rear direction BA to the sound absorption box 620, for example, a glass fiber impregnated sound absorption plate material such as SAB.

[0093] The suction sound box 620 is provided at a portion that is in the vehicle rear direction BA of the left front fender liner 42 and above the vehicle of the scooping member 520. The left front fender liner 42 is provided with a perforated structure 42a for communicating the wheel house of the left front wheel 32 and the suction sound box 620. The suction sound box 620 may contain a material capable of absorbing the radiated sound guided by the scooping member 520, for example, polyester fiber such as SAF.

[0094] Note that a scooping member 510 and a suction sound box 610 are similarly provided for the right front wheel 31 of the vehicle 10.

[0095] The scooping member 540 is formed so as to protrude from the bottom surface of the vehicle body 20 toward the ground 210 in the vehicle front direction FR of the left rear wheel 34. The scooping member 540 is also formed of, for example, a glass fiber impregnated sound absorbing plate material such as SAB. The suction sound box 640 is provided at a portion that is in the vehicle front direction FR of the left rear fender liner 44 and above the vehicle of the scooping member 540. The left rear fender liner 44 is provided with a perforated structure (not shown) for communicating the wheel house of the left rear wheel 34 and the suction sound box 640.

[0096] Note that a scooping member 530 and a suction sound box 630 are similarly provided for the right rear wheel 33 of the vehicle 10.

[0097] (Operation and Effect of the Vehicle Exterior Noise Reduction Structure of the Seventh Embodiment) In the vehicle exterior noise reduction structure 100 of the present embodiment, for example, as indicated by an arrow n42 in FIG. 31, the radiated sound radiated from the tire of the left front wheel 32 in the vehicle rear direction BA is collected along the scooping member 520 to the suction sound box 620 and absorbed by the suction sound box 620. Similarly, the radiated sound radiated from the tire of the left rear wheel 34 in the vehicle front direction FR is collected along the scooping member 540 to the suction sound box 640 and absorbed by the suction sound box 640. Thus, in the vehicle exterior noise reduction structure 100 of the present embodiment, since the radiated sound radiated from each of the wheels 31 to 34 can be efficiently absorbed, it is possible to more accurately reduce the vehicle exterior noise level.

[0098] (Modification example) Next, a modification example of the vehicle exterior noise reduction structure 100 of the seventh embodiment will be described.

[0099] In this embodiment, as shown in FIG. 32, the scooping member 520 may have the same or a similar shape as a spats that can reduce the resistance of the air flowing into the tire of the left front wheel 32. Although not shown, the same or a similar structure is provided for the right front wheel 31, the right rear wheel 33, and the left rear wheel 34.

[0100] Even with such a configuration, the same or similar operations and effects as those of the vehicle exterior noise reduction structure 100 of the seventh embodiment can be obtained.

[0101] <Other embodiments> The present disclosure is not limited to the above specific examples.

[0102] For example, the configurations of the vehicle exterior noise reduction structures 100 of the respective embodiments and modification examples can be used in combination with each other.

[0103] The shape, material, etc. of each element constituting the vehicle exterior noise reduction structure 100 can be changed as appropriate.

[0104] In order to further reduce the radiated noise radiated from the tires of the respective wheels 31 to 34, wheel skirts may be provided for the respective wheels 31 to 34.

[0105] Those obtained by appropriately making design changes by those skilled in the art to the above specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element, and its arrangement, conditions, shape, etc. included in the above-described specific examples are not limited to those illustrated and can be changed as appropriate. Each element included in the above-described specific examples can be changed in combination as appropriate as long as no technical contradiction occurs.

Description of reference numerals

[0106] 10: Vehicle, 20: Vehicle body, 21, 22: Locker part, 31 - 34: Wheels, 100: Vehicle exterior noise reduction structure, 110, 120: Front wheel reflection members, 111a, 121a: Opposing parts (first opposing parts), 111b, 121b: Drip wall parts (first drip wall parts), 112, 122, 411, 421: Sound absorption members (first sound absorption members), 132, 142, 431, 441: Sound absorption members (third sound absorption members), 620, 640: Sound absorption boxes, 130, 140: Rear wheel reflection members, 131a, 141a: Second opposing parts, 131b, 141b: Second drip wall parts, 150, 160: Fifth sound absorption members, 170: Sound absorption box (second sound absorption member), 180: Sound absorption box (fourth sound absorption member), 410, 420: Reflection members (front wheel reflection members), 430, 440: Reflection members (rear wheel reflection members), 520, 540: Scooping members, 710, 720, 730, 740: Sound absorption members (sixth sound absorption members).

Claims

1. A front-wheel reflecting member that is provided facing the rear direction of the vehicle with respect to the front wheels of the vehicle and reflects the radiated sound generated from the ground contact surface of the tires of the front wheels, and a first sound absorbing member that absorbs at least one of the radiated sound and the reflected sound reflected by the front-wheel reflecting member, wherein the first sound absorbing member is provided facing the front wheels of the vehicle in the vehicle front direction and absorbs the reflected sound reflected by the front-wheel reflecting member An external noise reduction structure for a vehicle.

2. The first sound absorbing member has a front-wheel rectifying structure configured such that the reflected sound reflected by the front-wheel reflecting member is diffused in the vehicle front direction The external noise reduction structure for a vehicle according to Claim 1.

3. A front-wheel reflecting member that is provided facing the rear direction of the vehicle with respect to the front wheels of the vehicle and reflects the radiated sound generated from the ground contact surface of the tires of the front wheels, and a first sound absorbing member that absorbs at least one of the radiated sound and the reflected sound reflected by the front-wheel reflecting member, and a second sound absorbing member that is provided below the center of the front end portion of the vehicle and absorbs the reflected sound reflected by the front-wheel reflecting member An external noise reduction structure for a vehicle.

4. The second sound absorbing member is a cylindrical member formed to extend in the vehicle left-right direction and having an opening that opens in the vehicle rear direction at a portion on the vehicle body center line of the vehicle. The external noise reduction structure for a vehicle according to Claim 3.

5. The second sound absorbing member is a cylindrical member formed to extend in the vehicle left-right direction and having an opening that opens toward the front wheels of the vehicle. The external noise reduction structure for a vehicle according to Claim 3.

6. The front-wheel reflecting member has a first facing portion provided facing the front wheels of the vehicle in the vehicle rear direction, and a first hanging wall portion formed to extend in the vehicle front direction along the side surface of the front wheel from the first facing portion. The external noise reduction structure for a vehicle according to any one of Claims 1 to 5.

7. Further provided is a first guiding member that guides the sound passing between the bottom surface of the vehicle body and the ground among the radiated sounds to the first sound absorbing member. The external noise reduction structure for a vehicle according to any one of Claims 1 to 5.

8. A rear-wheel reflecting member that is provided facing the front direction of the vehicle with respect to the rear wheels of the vehicle and reflects the radiated sound generated from the ground contact surface of the tires of the rear wheels, and a third sound absorbing member that absorbs at least one of the radiated sound and the reflected sound reflected by the rear-wheel reflecting member. The third sound absorbing member is provided to face the rear wheels of the vehicle in the vehicle rear direction, and absorbs the reflected sound reflected by the rear wheel reflecting member. Vehicle exterior noise reduction structure.

9. The third sound absorbing member has a rear wheel rectifying structure configured such that the reflected sound reflected by the rear wheel reflecting member is diffused in the vehicle rear direction. The vehicle exterior noise reduction structure of the vehicle according to claim 8.

10. A rear wheel reflecting member provided to face the rear wheels of the vehicle in the vehicle front direction and reflecting the radiated sound generated from the ground contact surface of the tires of the rear wheels, A third sound absorbing member that absorbs at least one of the radiated sound and the reflected sound reflected by the rear wheel reflecting member, A fourth sound absorbing member provided below the center of the rear end portion of the vehicle and absorbing the reflected sound reflected by the rear wheel reflecting member. Vehicle exterior noise reduction structure.

11. The fourth sound absorbing member is a cylindrical member formed to extend in the vehicle left-right direction and having an opening that opens in the vehicle front direction at a portion on the vehicle body center line. The vehicle exterior noise reduction structure of the vehicle according to claim 10.

12. The fourth sound absorbing member is a cylindrical member formed to extend in the vehicle left-right direction and having an opening that opens toward the rear wheels of the vehicle. The vehicle exterior noise reduction structure of the vehicle according to claim 10.

13. The rear wheel reflecting member A second facing portion provided to face the rear wheels of the vehicle in the vehicle front direction, A second hanging wall portion formed to extend from the second facing portion along the side surface of the rear wheel in the vehicle rear direction. The vehicle exterior noise reduction structure of the vehicle according to any one of claims 8 to 12.

14. Further provided with a second guiding member that guides the sound passing between the bottom surface of the vehicle body and the ground among the radiated sound to the third sound absorbing member. The vehicle exterior noise reduction structure of the vehicle according to any one of claims 8 to 12.

15. Further provided with a fifth sound absorbing member provided adjacent to the lower surface of a rocker portion that reinforces the lower side of a side door provided on a side portion of the vehicle and absorbing the radiated sound. The vehicle exterior noise reduction structure of the vehicle according to any one of claims 1, 3, 8, and 10.

16. Further provided with a sixth sound absorbing member provided inside the wheels of the front wheels or rear wheels of the vehicle. The vehicle exterior noise reduction structure of the vehicle according to any one of claims 1, 3, 8, and 10.

Images