Sound insulation structure of vehicle skeleton

Abstract

To provide a sound insulation structure of a vehicle skeleton which can improve sound insulation performance, while securing an opening in an upper face part of a side sill.SOLUTION: A sound insulation structure of a vehicle skeleton includes: a side sill 3; a pillar reinforcement 5a having a lower end joined to the side sill 3 and a closed cross section; a vertical wall part 14 extending upward from an upper face part 12 of the side sill 3; and a sound insulation plate 15 which is arranged so as to be separated upward from the upper face part 12, and forms a space part 16 extending in a vertical direction together with the upper face part 12, the vertical wall part 14 and the pilar reinforcement 5a. In an inside part 12a positioned inside the space part 16 in the upper face part 12, an opening 17 penetrating through the upper face part 12 is formed. The opening area of the opening 17 is set so that an opening ratio that is a ratio of the opening area to the area of the inside part 12a in the upper face part 12 is 0.2 or less.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sound insulation structure for a vehicle frame. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a structure in which a sound insulating plate is provided inside a hollow component of a vehicle frame (hereinafter referred to as a vehicle frame) in order to block running noise propagating through the frame that constitutes the body of a vehicle such as an automobile.

[0003] For example, in the vehicle body structure described in Patent Document 1, sound-proofing panels are provided in multiple locations inside the side sill that extends in the fore-and-aft direction of the vehicle body and inside the pillar reinforcement (hereinafter referred to as pillar reinforcement) that is joined to the upper surface of the side sill and extends in the up-and-down direction to separate the internal spaces of the side sill and the pillar reinforcement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-007941 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described structure, sound insulation performance is only obtained at the position where the sound insulation wall is provided in the vehicle frame, and the improvement in sound insulation performance is not sufficient relative to the increase in mass caused by the installation of the sound insulation wall.

[0006] On the other hand, in the vehicle frame, at the joint between two components that make up the vehicle frame, for example, at the joint between a side sill and a pillar rain extending above the side sill, there is a structure in which an opening is formed by penetrating the upper surface of the side sill, such as a flow hole that allows an electrolytic solution such as a rust inhibitor to flow into the side sill or to be discharged outside the side sill. In such a structure, sound is easily transmitted from the side sill to the pillar rain through the opening on the upper surface of the side sill, but there are circumstances in which the opening cannot be eliminated in order to allow the electrolytic solution to flow inside and outside the side sill. Therefore, there is an increasing demand for improvement in sound insulation performance around the joint having the opening.

[0007] In recent years, the design of vehicle frames has been progressing with the aim of making them stronger and thinner, but in side sills with such a thin structure, the effects of not only the sound that propagates to the pillar rain through openings such as the electrodeposition liquid flow holes provided on the upper surface of the side sill but also the transmitted sound that penetrates the upper surface of the side sill (so-called panel transmitted sound) become large. Therefore, it is necessary to improve the sound insulation performance of the entire vehicle frame structure.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a sound insulation structure for a vehicle frame that can improve sound insulation performance while ensuring an opening in the upper surface portion of the side sill. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the sound insulation structure of the vehicle frame of the present invention comprises a side sill that is arranged at the outer end of the bottom of the vehicle cabin and has a closed cross section extending in the fore-and-aft direction of the vehicle and an upper surface portion that constitutes an upper surface of the closed cross section, a pillar reinforcement that has a lower end joined to the side sill and a closed cross section extending in the vertical direction above the upper surface portion, a vertical wall portion extending upward from the upper surface portion, and a sound insulation plate that is arranged spaced upward from the upper surface portion and forms a space extending in the vertical direction together with the upper surface portion, the vertical wall portion and the pillar reinforcement, wherein an opening that penetrates the upper surface portion is formed in an inner portion that is located inside the space portion of the upper surface portion, and an opening area of ​​the opening is set so that an opening ratio, which is the ratio of the opening area to the area of ​​the inner portion of the upper surface portion, is 0.2 or less.

[0010] The present invention is characterized by utilizing the sound insulation performance of a double wall formed by a sound insulation plate and the upper surface of the side sill in order to improve the sound insulation performance against driving noise inside the side sill while securing an opening in the upper surface of the side sill.

[0011] That is, in the above configuration, the aperture ratio of the openings in the upper surface of the side sill is set to 0.2 or less, so that, as will be described in detail later, the sound transmitted through the upper surface of the side sill becomes dominant over the sound that enters the space through the openings. Therefore, it is possible to obtain sufficient sound insulation performance of the double wall between the sound insulation plate and the upper surface of the side sill. This makes it possible to improve sound insulation performance by installing fewer sound insulation plates while securing holes in the upper surface of the side sill.

[0012] Here, the sound insulation performance of a double wall in the present invention refers to a structure in which two walls are placed at a distance from each other and the mass of the two walls and the elasticity of the air layer between them are utilized to obtain a sound insulation performance that is higher than the sound insulation performance of a single wall having the same mass as the total mass of the two walls.

[0013] In the above vehicle frame sound insulation structure, the opening ratio is preferably set to 0.003 or more.

[0014] With this configuration, it is possible to ensure the flow performance of liquid that seeps into the inside of the side sill through the opening during vehicle manufacture, such as anti-rust electrochemical deposition liquid, between the inside and outside of the side sill.

[0015] In the above-mentioned sound insulation structure for the vehicle frame, it is preferable that the sound insulation panel comprises a plate-shaped base material and a sound-absorbing material having sound-absorbing performance that is arranged on the periphery of the base material, and that the sound-absorbing material fills the gap between the pillar reinforcement and the base material, and the gap between the vertical wall portion and the base material.

[0016] According to this configuration, the sound absorbing material fills the gap between the pillar reinforcement and the base material of the sound insulation plate, and the gap between the vertical wall portion and the base material, thereby making it possible to reliably insulate sound.

[0017] In the above-mentioned sound insulation structure for a vehicle frame, it is preferable that the opening is an electrodeposition liquid flow hole through which the electrodeposition liquid can flow inside and outside the side sill, and that a plurality of the electrodeposition liquid flow holes are formed at a distance from each other in the inner portion of the upper surface portion.

[0018] With this configuration, it is possible to ensure the performance of allowing electrodeposition liquid for rust prevention or the like to flow between the inside and outside of the side sill through the opening (so-called flow performance).

[0019] In the above-mentioned sound insulation structure for the vehicle frame, it is preferable that a height ratio, which is the ratio of the height to the sound insulation plate to the height to the upper end of the vertical wall portion based on the upper surface portion of the side sill, is set to be greater than or equal to 0.2 and less than or equal to 1.

[0020] According to this configuration, by setting the height ratio to 0.2 or more, it is possible to improve the sound insulation gradient compared to when the height ratio is less than 0.2, and it is possible to reliably improve the sound insulation performance.

[0021] In the above vehicle frame sound insulation structure, the height ratio is preferably set to 0.4 or more.

[0022] According to this configuration, it is possible to obtain sound insulation that exceeds the range in which the sound insulation gradient is large in the height ratio range of 0.2 to 0.4, and it is possible to further improve the sound insulation performance.

[0023] In the above-mentioned sound insulation structure for the vehicle frame, it is preferable that the side sill comprises a side sill outer and a side sill inner located inward in the vehicle width direction than the side sill outer, the side sill outer and the side sill inner extend in the fore-and-aft direction of the vehicle and have a hat-shaped cross-sectional shape with flange portions at their upper and lower ends, the side sill is formed by joining the flange portions of the side sill outer and the side sill inner to each other, and the vertical wall portion is formed by the flange portions protruding upward from the side sill outer and the side sill inner.

[0024] According to this configuration, it is possible to adopt a side sill having a conventional hat-shaped cross-sectional side sill outer and side sill inner. Therefore, this sound insulation structure is highly versatile and can reduce manufacturing costs. Effect of the Invention

[0025] As described above, according to the vehicle frame sound insulation structure of the present invention, it is possible to improve the sound insulation performance while ensuring an opening in the upper surface portion of the side sill. [Brief description of the drawings]

[0026] [Figure 1] 1 is a front view showing a main configuration of a vehicle body to which a sound insulation structure for a vehicle frame according to an embodiment of the present invention is applied; [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4]It is a cross-sectional explanatory view of a sound insulation board provided with a base material and a foam material showing an example of the sound insulation board of FIG. 2. [Diagram 5] (a)-(c) are process cross-sectional explanatory views showing the attachment procedure of the sound insulation board of FIG. 4. [Figure 6] (a)-(c) are enlarged plan views showing the attachment procedure of the sound insulation board of FIG. 4. (a) is an enlarged plan view of the periphery of the opening of the upper surface part of the side sill before attaching the sound insulation board, (b) is an enlarged plan view showing the state before foaming of the foam material immediately after attaching the sound insulation board of FIG. 4, and (c) is an enlarged plan view showing the state after the foam material of the sound insulation board in (b) has foamed. [Figure 7] (a) It is a graph showing the change in the sound reduction volume with respect to the opening ratio in four models of (a) single-layer structure S1 without holes, (b) single-layer structure S2 with holes, (c) multi-layer structure S3 without holes, and (d) multi-layer structure S4 with holes. [Figure 8] As a model schematically showing changing the height of the sound insulation board of the present embodiment, it is a view showing a state where the height h of the foam material with respect to the plate having an opening is changed within the range of the flange height H. (a) shows the case where h = 0, (b) shows the case where 0 < h < H, and (c) shows the case where h = H. [Figure 9] It is a graph showing the relationship between the height ratio h / H of the installation of the foam material with respect to the flange height H and the sound reduction volume. [Figure 10] It is a bar graph showing the sound pressure in the sound insulation structure of FIG. 11 as a comparative example and the sound insulation structure of the present embodiment. (I) shows the sound pressure inside the pillar, (II) shows the sound pressure at a position close to the pillar trim, and (III) shows the sound pressure at the position of the ear of the occupant in the vehicle. [Figure 11] It is a cross-sectional view showing a conventional sound insulation structure in which the foam material in the comparative example of the present invention directly closes the opening of the upper surface part of the side sill. [Figure 12] It is an enlarged plan view showing a state where the foam material closes the opening and the inner peripheral surface of the pillar rain on the surface of the upper surface part of the side sill in the conventional sound insulation structure of FIG. 11.

Embodiments for Carrying Out the Invention

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a sound insulation structure for a vehicle frame according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0028] FIG. 1 is a front view showing the main configuration of a vehicle body 1 to which a vehicle frame sound insulation structure according to an embodiment of the present invention is applied.

[0029] The vehicle body 1 includes, on both sides in the vehicle width direction, side sills 3 extending in the vehicle front-rear direction X, front pillars 4 (A-pillars) extending upward Z1 from an end of the side sill 3 on the vehicle front side X1, a center pillar 5 (B-pillar) extending upward Z1 at a midpoint in the vehicle front-rear direction X of the side sill 3, a rear pillar 6 (C-pillar) extending upward Z1 from near an end of the side sill 3 on the vehicle rear side X2, and a roof rail 7 extending in the vehicle front-rear direction X connecting the upper ends of these three pillars 4 to 6. The side sills 3, the three pillars 4 to 6, and the roof rail 7 form both sides in the vehicle width direction of the vehicle frame.

[0030] In the above vehicle body 1, the sound insulation structure of this embodiment is disposed near the joint between the side sill 3 and the lower end of the center pillar 5, as shown in FIG.

[0031] The side sill 3 is a hollow member disposed at the outer end of the bottom of the vehicle interior 2 and extending in the vehicle front-rear direction X. Specifically, as shown in Fig. 2, the side sill 3 includes a side sill outer 3a, a side sill inner 3b located on the inner side Y2 in the vehicle width direction than the side sill outer 3a, and a reinforcing plate 3c interposed between the side sill outer 3a and the side sill inner 3b.

[0032] The side sill outer 3a extends in the vehicle longitudinal direction X and has a hat-shaped cross section with flanges 3a1, 3a2 at the upper and lower ends. Similarly to the side sill outer 3a, the side sill inner 3b also extends in the vehicle longitudinal direction X and has a hat-shaped cross section with flanges 3b1, 3b2 at the upper and lower ends.

[0033] The side sill 3 has a structure having a hollow closed cross section 11 by joining upper and lower flange portions 3a1, 3a2 of the side sill outer 3a and upper and lower flange portions 3b1, 3b2 of the side sill inner 3b to each other. The side sill 3 also has an upper surface portion 12 that constitutes the upper surface of the closed cross section 11. An opening 17 (see FIGS. 2 and 3), which will be described later, is formed in this upper surface portion 12.

[0034] The vertical wall portion 14 extends upward Z1 from the upper surface portion 12 of the side sill 3. The vertical wall portion 14 in this embodiment is formed by joining upwardly protruding flange portions 3a1, 3b1 of the side sill outer member 3a and the side sill inner member 3b.

[0035] The reinforcing plate 3c has an upper end sandwiched between the two upper flange portions 3a1, 3b1 and a lower end sandwiched between the two lower flange portions 3a2, 3b2, thereby reinforcing the closed cross section 11 of the side sill 3 from the inside and suppressing deformation of the closed cross section 11. Although the side sill 3 of this embodiment has the reinforcing plate 3c, it may be omitted.

[0036] The center pillar 5 includes a pillar rain 5a having a closed cross section 13, and an outer panel (not shown) that covers the outer side Y1 of the pillar rain 5a in the vehicle width direction.

[0037] 2, the pillar rain 5a is a member extending in the up-down direction Z. A lower end 5c of the pillar rain 5a is joined to the side sill 3. The pillar rain 5a has a closed cross section 13 extending in the up-down direction Z above the upper surface portion 12 of the side sill 3. In this embodiment, the pillar rain 5a forms the closed cross section 13 by joining and integrating the pillar rain outer 5a1 and the inner panel 5a2 on the vehicle width direction inner side Y2 thereof.

[0038] The sound insulation plate 15 is disposed at a distance upward Z1 from the upper surface portion 12 of the side sill 3. As a result, the sound insulation plate 15, together with the upper surface portion 12, the vertical wall portion 14, and the pillar rain 5a, forms a space portion 16 (see FIGS. 2 and 3) extending in the up-down direction Z. As a result, the sound generated inside the side sill 3 while the vehicle is traveling can be reduced by the sound insulation performance of the double wall formed by the upper surface portion 12 of the side sill 3, the sound insulation plate 15, and the space portion 16 sandwiched between them, which passes through the sound insulation plate 15 and travels upward Z1 inside the pillar rain 5a.

[0039] The sound insulation plate 15 only needs to have a configuration that closes the upper end of the space 16 and blocks or suppresses the transmission of sound upward through the space 16, and any structure and material may be used as long as it has such a configuration.

[0040] Specifically, as shown in Figures 4 to 6, the sound-proofing panel 15 of this embodiment comprises a plate-shaped base material 15a having an area sufficient to close the upper end of the space portion 16, and a sound-absorbing material 15b having sound-absorbing properties, such as a foam material, that is arranged on the periphery of the base material 15a.

[0041] The base material 15a has a plate-shaped main body portion 15a1 and an annular flange portion 15a2 that surrounds the main body portion 15a1 at a position one step lower than the outer periphery of the main body portion 15a1.

[0042] The sound absorbing material 15b is made of a foam material having sound absorbing properties and is disposed on the entire circumference of the annular flange portion 15a2. Any material having sound absorbing properties can be used for the sound absorbing material 15b, and may be an elastic material such as rubber other than foam material.

[0043] 5(a)-(c) and 6(b) and (c), the sound absorbing material 15b made of a foam material in this embodiment closes the gap between the pillar rain 5a and the base material 15a and the gap between the vertical wall portion 14 and the base material 15a when the sound insulation plate 15 is disposed at a distance Z1 above the upper surface portion 12 of the side sill 3. The foam material foams and expands in volume due to heat received when the vehicle body 1 is heated to dry the electrodeposition liquid described later, and is thereby able to close these gaps.

[0044] The sound insulation plate 15 may be configured to be fixed at a predetermined height position spaced upward Z1 from the upper surface portion 12 of the side sill 3, for example, it may have a convex portion that can engage with a concave portion formed in the pillar rain 5a.

[0045] (Explanation of opening 17) In this embodiment, as shown in Figures 2-3 and Figure 6(a), an opening 17 penetrating the upper surface portion 12 is formed in an inner portion 12a located inside the space portion 16 in the upper surface portion 12 of the side sill 3.

[0046] The opening 17 in this embodiment is an electrodeposition liquid flow hole through which the electrodeposition liquid A (see FIG. 5(b)) can flow (that is, flow in and out) into and out of the side sill 3.

[0047] A plurality of openings 17 as electrodeposition liquid flow holes are formed spaced apart from one another in the inner portion 12a of the upper surface portion 12 of the side sill 3. For example, as shown in Fig. 6(a) , three openings 17 are formed spaced apart from one another in the vehicle front-rear direction X in the inner portion 12a.

[0048] The electrochemical solution A is applied to the entire vehicle body 1 for rust prevention after painting the vehicle body 1 by, for example, immersing the vehicle body 1 in an electrolyte tank. When electrochemical solution A is to be introduced into the side sill 3 through the opening 17, as shown in FIG. 5(a), the sound insulation plate 15 is fixed at a predetermined height position spaced apart from the inner portion 12a of the upper surface portion 12 of the side sill 3 between the pillar rain 5a of the center pillar 5 and the vertical wall portion 14, and then, as shown in FIG. 5(b), the sound insulation plate 15 is slightly tilted to form a gap 20 between the vertical wall portion 14 and the sound insulation plate 15 in advance. The electrochemical solution A can be introduced into the side sill 3 through the opening 17 via the gap 20.

[0049] After applying the electrodeposition liquid A to the entire vehicle body 1, the inclination of the sound insulation board 15 is corrected and the vehicle body 1 is dried in a drying oven to dry the electrodeposition liquid A. At this time, the sound absorbing material 15b made of a foam material of the sound insulation board 15 foams and expands, thereby making it possible to close the gap between the sound insulation board 15 and the pillar rain 5a and between the sound insulation board 15 and the vertical wall portion 14.

[0050] Incidentally, excess electrolytic solution A may be discharged from inside side sill 4 through opening 17 before electrolytic solution A is dried.

[0051] In order to obtain the sound insulation performance of a double wall formed by the upper surface portion 12, the sound insulation panel 15 and the space portion 16, it is preferable that the opening area of ​​the opening 17 is set so that the opening ratio, which is the ratio of the opening area to the area of ​​the inner portion 12a of the upper surface portion 12, is greater than 0 and is not greater than 0.2.

[0052] Here, in order to verify the setting range of the above-mentioned aperture ratio, the relationship between the aperture ratio and the sound volume reduction will be examined with reference to FIG.

[0053] FIG. 7 is a graph showing the change in sound volume reduction versus the aperture ratio in four models: (a) a single-layer structure S1 without holes, (b) a single-layer structure S2 with holes, (c) a multi-layer structure S3 without holes, and (d) a multi-layer structure S4 with holes.

[0054] Here, (a) the non-perforated single-layer structure S1 is a structure in which a first layer 32 and a second layer 33 of the same material, thickness and mass are stacked together to form a single layer within a tube 31 through which sound passes, dividing the space within the tube 31. (b) A single layer structure S2 with a hole is a structure in which a through hole 34 is formed penetrating the overlapping first layer 32 and second layer 33 of (a). (c) The non-hole multi-layer structure S3 is a structure in which the first layer 32 and the second layer 33 of (a) are spaced apart in the extension direction of the tube 31. (d) A multi-layer structure S4 with holes is a structure in which through-holes 36 are formed penetrating the first layer 32 of (c).

[0055] According to the graph in FIG. 7, it can be seen that in the single-layer structure S2 with holes, the sound reduction increases as the opening ratio of the through-holes 34 decreases, and when the opening ratio becomes 0.2 or less, the gradient of the sound reduction increases and the sound reduction effect increases further, eventually reaching the sound reduction of the single-layer structure S1 without holes.

[0056] Also, in the perforated multi-layer structure S4, the sound reduction increases as the opening ratio of the through holes 36 penetrating the first layer 32 decreases, but when the opening ratio becomes 0.2 or less, the gradient of the sound reduction becomes much steeper than that in the perforated single-layer structure S2, and the sound reduction effect increases further, eventually reaching the sound reduction of the non-perforated multi-layer structure S3.

[0057] From the results of the graph in Figure 7, it can be considered that in the perforated multi-layer structure S4, when the opening ratio is 0.2 or less, the sound reduction effect is further increased due to the sound insulation performance of the double wall that was not achieved in the perforated single-layer structure S2.

[0058] In order to ensure the flow performance of the electrodeposition solution A passing through the openings 17 between the inside and outside of the side sill 3, it is preferable that the opening ratio of the openings 17 is set to 0.003 or more.

[0059] In addition, in order to improve the sound insulation performance, the height ratio h / H of the height h to the sound insulation board 15 with respect to the height H (see Fig. 5(c)) from the upper surface portion 12 of the side sill 3 to the upper end of the vertical wall portion 14 is preferably set to be 0.2 or more and 1 or less, more preferably 0.4 or more.

[0060] Here, in order to verify the setting range of the height ratio h / H of the sound insulation board 15, the relationship between the height ratio and the sound reduction volume is examined with reference to Figs. 8 to 9.

[0061] Figs. 8(a) to (c) show a model schematically showing changing the height of the sound insulation board 15 of the present embodiment, including a first wall 41 corresponding to the pillar lane 5a, a second wall 42 having a flange height H corresponding to the vertical wall portion 14, a reference plate 43 having an opening 45 corresponding to the inner portion 12a of the upper surface portion 12 of the side sill 3, and a foam material 44 spaced upward from the reference plate 43 by a height h. Figs. 8(a) to (c) show the state where the height h of the foam material 44 with respect to the reference plate 43 is changed within the range of the flange height H. Specifically, Fig. 8(a) shows the case where h = 0, (b) shows the case where 0 < h < H, and (c) shows the case where h = H. Here, the flange height H in Fig. 8(c) is the distance from the upper surface of the reference plate 43 to the lower surface of the foam material 44 when the upper surface of the foam material 44 is at the height of the upper end 42a of the second wall 42, that is, the maximum height of the space between the reference plate 43 and the foam material 44.

[0062] Fig. 9 shows a graph showing the relationship between the height ratio h / H of the foam material 44 to the flange height H of the second wall 42 in Fig. 8 and the sound reduction volume.

[0063] Looking at the graph in Fig. 9, it can be seen that by setting the height ratio h / H to 0.2 or more, the gradient of the sound insulation volume is improved compared to the case where the height ratio h / H is less than 0.2. Therefore, if the height ratio h / H is set to 0.2 or more, it is considered that the sound insulation performance can be surely improved.

[0064] Furthermore, by setting the height ratio h / H to 0.4 or more, it is possible to obtain sound insulation that exceeds the range of 0.2 to 0.4 in which the sound insulation gradient is large, and therefore it is believed that sound insulation performance can be further improved.

[0065] Next, the sound insulation performance of the sound insulation structure of this embodiment shown in FIG. 2 will be compared with that of the sound insulation structure of the comparative example shown in FIGS. 11 and 12 using the graph in FIG.

[0066] 11 and 12 is a conventional sound insulation structure (corresponding to the holeless single layer structure S1 in FIG. 7(a)) in which the foam material 21 directly covers the openings 17 in the inner portion 12a of the upper surface portion 12 of the side sill 3. Specifically, as shown in FIG. 12, the foam material 21 covers three openings 17 on the surface of the inner portion 12a of the upper surface portion 12 of the side sill 3 and the inner peripheral surface of the pillar rain 5a.

[0067] FIG. 10 shows bar graphs indicating sound pressure in the sound insulation structure of FIG. 11 as a comparative example and the sound insulation structure of this embodiment shown in FIG. 2, and respectively shows sound pressures at (I) inside the pillar, (II) a position close to the pillar trim, and (III) the position of the occupant's ear in the vehicle (specifically, on the left window side of the front seat).

[0068] The position close to the pillar trim is a position on the vehicle interior side close to the pillar trim 22 located on the inner side Y2 in the vehicle width direction than the vertical wall portion 14 shown in FIG. 6(a).

[0069] The graph in FIG. 10 shows that the sound pressure in the sound insulation structure of this embodiment is significantly reduced compared to the sound pressure in the sound insulation structure of the comparative example in all three locations: (I) inside the pillar, (II) near the pillar trim, and (III) at the ears of the occupants in the vehicle.

[0070] (Features of this embodiment) (1) The vehicle frame sound insulation structure of this embodiment includes a side sill 3 having a closed cross section 11, a pillar rain 5a having a closed cross section 13 and a lower end 5c joined to the side sill 3, a vertical wall portion 14 extending upward Z1 from an upper surface portion 12 of the side sill 3, and a sound insulation plate 15 arranged spaced upward Z1 from the upper surface portion 12 and forming a space portion 16 extending in the up-down direction Z together with the upper surface portion 12, the vertical wall portion 14 and the pillar rain 5a. An opening 17 penetrating the upper surface portion 12 is formed in an inner portion 12a located inside the space portion 16 in the upper surface portion 12.

[0071] The opening area of ​​the opening 17 is set so that the opening ratio, which is the ratio of the opening area to the area of ​​the inner portion 12a of the upper surface portion 12, is 0.2 or less (greater than 0).

[0072] In the above configuration, the aperture ratio of the opening 17 in the upper surface 12 of the side sill 3 is set to 0.2 or less, so that with respect to the driving noise propagating within the side sill 3, the transmitted sound that passes through the upper surface 12 of the side sill 3 becomes dominant over the sound that enters the space 16 through the opening 17, making it possible to obtain sufficient sound insulation performance of the double wall between the sound insulation plate 15 and the upper surface 12 of the side sill 3. This makes it possible to improve the sound insulation performance by installing fewer sound insulation plates 15 while securing holes in the upper surface 12 of the side sill 3.

[0073] (2) In the sound insulation structure for a vehicle frame of this embodiment, the opening ratio is set to be equal to or greater than 0.003, which makes it possible to ensure a flow performance that allows the electrodeposition liquid that has entered the inside of the side sill 3 through the opening 17 during vehicle manufacture to flow between the inside and outside of the side sill 3.

[0074] (3) In the vehicle frame sound insulation structure of this embodiment, the sound insulation plate 15 includes a plate-shaped base material 15a and a sound absorbing material 15b having sound absorbing properties, such as a foam material, arranged on the periphery of the base material 15a. The sound absorbing material 15b fills the gap between the pillar rain 5a and the base material 15a, and the gap between the vertical wall portion 14 and the base material 15a. By filling the gap between the pillar rain 5a and the base material 15a, and the gap between the vertical wall portion 14 and the base material 15a with the sound absorbing material 15b, it is possible to reliably insulate noise.

[0075] (4) In the sound insulation structure for a vehicle frame of this embodiment, the openings 17 are electrodeposition liquid flow holes that allow the electrodeposition liquid to flow inside and outside the side sill 3. The openings 17 as a plurality of electrodeposition liquid flow holes are formed spaced apart from one another in the inner portion 12a of the upper surface portion 12. With this configuration, it is possible to ensure the performance of allowing the electrodeposition liquid for rust prevention or the like to flow inside and outside the side sill 3 through the openings 17 (so-called flow performance).

[0076] (5) In the vehicle frame sound insulation structure of this embodiment, the height ratio h / H, which is the ratio of the height h to the sound insulation plate 15 to the height H to the top end of the vertical wall portion 14 based on the top surface portion 12 of the side sill 3, is set to be 0.2 or more and 1 or less. This makes it possible to improve the gradient of sound insulation compared to a case where the height ratio h / H is less than 0.2, and makes it possible to reliably improve sound insulation performance.

[0077] (6) In the vehicle frame sound insulation structure of this embodiment, the height ratio h / H is set to 0.4 or more. With this configuration, sound insulation exceeding the range where the sound insulation gradient is large in the height ratio h / H range of 0.2 to 0.4 can be obtained, and sound insulation performance can be further improved.

[0078] (7) In the vehicle frame sound insulation structure of this embodiment, the side sill 3 includes a side sill outer 3a and a side sill inner 3b located on the vehicle width direction inner side Y2 of the side sill outer 3a. The side sill outer 3a and the side sill inner 3b extend in the vehicle front-rear direction X and have a hat-shaped cross section with flange portions 3a1, 3b1, 3a2, and 3b2 at their upper and lower ends. The side sill 3 is formed by joining the flange portions 3a1, 3b1, 3a2, and 3b2 of the side sill outer 3a and the side sill inner 3b to each other. The vertical wall portion 14 is formed by the flange portions 3a1 and 3b1 protruding upward from the side sill outer 3a and the side sill inner 3b.

[0079] In this configuration, it is possible to adopt a side sill 3 equipped with a side sill outer 3a and a side sill inner 3b having a conventional hat-shaped cross section. Therefore, this sound insulation structure is highly versatile and can reduce manufacturing costs.

[0080] (Modification) (A) In the above embodiment, as an example of a vertical wall portion extending upward from the side sill, an example is shown in which the vertical wall portion 14 is formed by the flange portions 3a1, 3b1 protruding upward from the side sill outer 3a and the side sill inner 3b, each having a hat-shaped cross section. However, the present invention is not limited to this, and any vertical wall portion extending upward from the side sill is sufficient. For example, the present invention also includes a form in which a vertical wall portion extending upward is attached by welding or the like to the upper surface portion of a side sill having a closed cross section, and a form in which a side sill having a vertical wall portion is integrally molded.

[0081] (B) In the above embodiment, the opening 17 used as an electrolyte flow hole is described as an example of the opening of the present invention, but the present invention is not limited thereto. The opening of the present invention may be an opening for any purpose as long as it is an opening formed in the inner part of the space between the pillar rain and the vertical wall part of the upper surface part of the side sill. For example, a hole for passing an electric cable or the like is also included in the opening of the present invention.

[0082] (C) In the above embodiment, the pillar rain 5a of the center pillar 5 is used as an example of a pillar rain, but the present invention is not limited to this, and the pillar rain may be a front pillar or a rear pillar as long as it is a pillar having a pillar rain that is joined to the side sill and has a closed cross section that extends above the side sill. [Explanation of symbols]

[0083] 1. Vehicle body 2 Cabin 3 Side sill 3a Side sill outer 3b Side sill inner 4 Front pillar 5 Center pillar 5a Pillar Rain 6 Rear pillar 7 Roof rails 11 Closed section 12 Top part 12a Inner part 13 Closed section 14 Vertical wall section 15 Soundproofing board 15a Base material 15b Foam material 16 Space section 17 Opening

Claims

1. a side sill disposed at an outer end of a vehicle interior bottom of the vehicle, the side sill having a closed cross section extending in a vehicle front-rear direction and an upper surface portion constituting an upper surface of the closed cross section; a pillar reinforcement having a closed cross section extending in a vertical direction above a lower end portion joined to the side sill and above the upper surface portion; A vertical wall portion extending upward from the upper surface portion; a sound insulation plate disposed above and spaced apart from the upper surface portion, the sound insulation plate forming a space portion extending in a vertical direction together with the upper surface portion, the vertical wall portion, and the pillar reinforcement; Equipped with an opening penetrating the upper surface portion is formed in an inner portion located inside the space portion in the upper surface portion, The opening area of ​​the opening is set so that an opening ratio, which is a ratio of the opening area to an area of ​​the inner portion of the upper surface portion, is 0.2 or less. A sound insulation structure for a vehicle frame.

2. The sound insulation structure for a vehicle frame according to claim 1, The aperture ratio is set to 0.003 or more. A sound insulation structure for a vehicle frame.

3. The sound insulation structure for a vehicle frame according to claim 1, The sound insulation plate is A plate-shaped substrate; A sound-absorbing material having sound-absorbing properties and arranged on the periphery of the base material, The sound absorbing material fills a gap between the pillar reinforcement and the base material, and a gap between the vertical wall portion and the base material. A sound insulation structure for a vehicle frame.

4. The sound insulation structure for a vehicle frame according to claim 1, the opening is an electrodeposition liquid flow hole through which the electrodeposition liquid can flow inside and outside the side sill, a plurality of the electrodeposition liquid flow holes are formed in the inner portion of the upper surface portion and spaced apart from each other; A sound insulation structure for a vehicle frame.

5. The sound insulation structure for a vehicle frame according to any one of claims 1 to 4, A sound insulation structure for a vehicle frame, wherein a height ratio, which is a ratio of a height to the sound insulation plate to a height to the upper end of the vertical wall portion based on the upper surface portion of the side sill, is set to 0.2 or more and 1 or less.

6. The sound insulation structure for a vehicle frame according to claim 5, The height ratio is set to 0.4 or more. Sound insulation structure of vehicle frame.

7. The sound insulation structure for a vehicle frame according to any one of claims 1 to 4, The side sill includes a side sill outer and a side sill inner located on the inner side of the side sill outer in a vehicle width direction, The side sill outer and the side sill inner extend in a vehicle front-rear direction and have a hat-shaped cross section with flange portions at upper and lower ends, The side sill is formed by joining flange portions of the side sill outer and the side sill inner to each other, The vertical wall portion is constituted by the side sill outer and the flange portion protruding upward from the side sill inner. Sound insulation structure of vehicle frame.

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