Sound insulation structure of vehicle framework

Abstract

The purpose of the present invention is to provide a sound insulation structure for a vehicle frame capable of securing an opening in a side member upper surface portion and improving sound insulation performance. A sound insulation structure for a vehicle frame is provided with: a side member (3); a pillar reinforcement (5a) having a closed cross-section and a lower end portion joined to the side member (3); a vertical wall portion (14) extending upward from an upper side surface portion (12) of the side member (3); and a sound insulation plate (15) disposed apart upward from the upper side surface portion (12) and forming a space portion (16) extending in the vertical direction together with the upper side surface portion (12), the vertical wall portion (14), and the pillar reinforcement (5a). An opening portion (17) penetrating through the upper side surface portion (12) is formed in an inner side portion (12a) of the upper side surface portion (12), the inner side portion (12a) being located on the inner side of the space portion (16). The opening area of the opening portion (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 side surface portion (12), is 0.2 or less.

Description

Technical Field

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

[0002] Currently, there is a known structure in which a sound insulation panel is provided inside a hollow structural member of a vehicle skeleton (hereinafter referred to as a vehicle skeleton) in order to block traveling noise transmitted through the skeleton that constitutes a vehicle body in a vehicle such as an automobile.

[0003] For example, in the body structure described in Patent Document 1, inside a side sill that extends in the vehicle front-rear direction in the body, inside a pillar reinforcement that is joined to the upper side surface of the side sill and extends in the vertical direction, etc., a plurality of sound insulation panels are provided so as to partition the respective internal spaces of the side sill and the pillar reinforcement.

[0004] [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-007941. Summary of the Invention

[0005] [Technical Problem to be Solved by the Invention] However, in the above structure, there is sound insulation performance only at the positions where the sound insulation walls are provided in the vehicle skeleton, and the improvement in sound insulation performance is not sufficient compared to the part where the mass increases due to the provision of the sound insulation walls.

[0006] On the other hand, in the vehicle skeleton, there is the following structure: at the joint portion of two constituent members that constitute the vehicle skeleton, for example, at the joint portion of a side sill and a pillar reinforcement that extends above the side sill, an opening formed by penetrating the upper side surface portion of the side sill, such as a circulation hole for allowing an electrodeposition liquid for rust prevention or the like to flow into the side sill or discharge it to the outside of the side sill, is formed. In such a structure, although sound easily passes from the side sill to the pillar reinforcement through the opening in the upper side surface portion of the side sill, it is necessary to provide the opening in order to allow the electrodeposition liquid to flow in and out of the side sill. Therefore, there is an increasing demand for improving the sound insulation performance around the joint portion having the opening.

[0007] In addition, in recent years, in the design, efforts have been made to make the vehicle skeleton high-strength and thin. In a side sill having such a thin structure, not only the sound transmitted from the side sill to the pillar reinforcement through openings such as electrodeposition liquid circulation holes provided in the upper side surface portion of the side sill, but also the influence of penetration sound (so-called panel penetration sound) penetrating the upper side surface portion of the side sill becomes large. Therefore, it is necessary to improve the sound insulation performance of the entire structure of the vehicle skeleton.

[0008] In view of the above circumstances, an object of the present invention is to provide a sound insulation structure for a vehicle frame that can ensure an opening in the upper side surface of a side beam and improve sound insulation performance.

[0009]

Technical means for solving technical problems

[0010] The present invention has the following characteristic points: In order to ensure an opening in the upper side surface of the side beam and improve the sound insulation performance against traveling tones inside the side beam, the sound insulation performance of the double walls of the sound insulation panel and the upper side surface of the side beam is utilized.

[0011] That is, in the above structure, the opening ratio of the opening in the upper side surface of the side beam is set to 0.2 or less. Thus, regarding the traveling tones propagating inside the side beam, as will be described in detail later, the penetrating sound penetrating the upper side surface of the side beam is more dominant than the sound entering the space portion through the opening. Therefore, sufficient sound insulation performance of the double walls can be obtained by the sound insulation panel and the upper side surface of the side beam. Thereby, the holes in the upper side surface of the side beam can be ensured and the sound insulation performance can be improved by providing fewer sound insulation panels.

[0012] Here, the sound insulation performance of the double walls in the present invention means that: two walls are disposed separately, and higher sound insulation performance is obtained by utilizing the mass of the two walls and the elasticity of the air layer between them compared to the sound insulation performance of one wall having the same total mass as the two walls.

[0013] Preferably, in the sound insulation structure of the vehicle frame described above, the opening ratio is set to 0.003 or more.

[0014] According to the above solution, the circulation performance can be ensured such that liquids entering the inside of the side beam through the opening during vehicle manufacturing, such as electrodeposition liquid for rust prevention, can flow inside and outside the side beam.

[0015] Preferably, in the sound insulation structure of the vehicle frame, the sound insulation panel includes a plate-shaped base material and a sound absorption material having sound absorption performance disposed on the periphery of the base material, and the sound absorption material closes the gap between the pillar reinforcement and the base material, and the gap between the longitudinal wall portion and the base material.

[0016] According to the above solution, by closing the gap between the pillar reinforcement and the base material of the sound insulation panel and the gap between the longitudinal wall portion and the base material with the sound absorption material, sound insulation can be effectively achieved.

[0017] Preferably, in the sound insulation structure of the vehicle frame, the opening is an electrodeposition liquid circulation hole that allows the electrodeposition liquid to flow in and out of the side beam, and in the inner part of the upper side surface portion, a plurality of the electrodeposition liquid circulation holes are separated from each other.

[0018] In the above solution, the performance (so-called circulation performance) of allowing the electrodeposition liquid used for rust prevention and the like to flow in and out of the side beam through the opening can be ensured.

[0019] Preferably, in the sound insulation structure of the vehicle frame, the height ratio is set to be 0.2 or more and 1 or less, and this height ratio is the ratio of the height to the sound insulation panel to the height to the upper end of the longitudinal wall portion based on the upper side surface portion of the side beam.

[0020] According to the above solution, compared with when the height ratio is less than 0.2, by setting the above height ratio to 0.2 or more, the gradient of the sound insulation amount can be increased, and the sound insulation performance can be effectively improved.

[0021] Preferably, in the sound insulation structure of the vehicle frame, the height ratio is set to be 0.4 or more.

[0022] According to the above solution, the obtained sound insulation amount exceeds the range with a large gradient of the sound insulation amount in the range of 0.2 to 0.4 of the height ratio, and the sound insulation performance can be further improved.

[0023] Preferably, in the sound insulation structure of the vehicle frame, the side beam includes an outer side beam and an inner side beam located on the inner side in the vehicle width direction compared to the outer side beam. The outer side beam and the inner side beam extend in the vehicle front-rear direction, have flange portions at their upper and lower ends, and have a hat-shaped cross section. The side beam is formed by joining the flange portions of the outer side beam and the inner side beam to each other, and the longitudinal wall portion is formed by the flange portions that protrude upward in the outer side beam and the inner side beam.

[0024] According to the above solution, it is possible to adopt an existing side beam having an outer side beam and an inner side beam with a hat-shaped cross section. Therefore, the versatility of this sound insulation structure is high, and the manufacturing cost can be suppressed.

[0025] Advantages of the Invention As described above, the sound insulation structure of the vehicle frame according to the present invention can ensure the opening in the upper side surface of the side beam and improve the sound insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Front view of the main components of a vehicle body to which the sound insulation structure of the vehicle frame according to an embodiment of the present invention is applied; Figure 2 Along Figure 1 Cross-sectional view taken along line II-II; Figure 3 Along Figure 1 Cross-sectional view taken along line III-III; Figure 4 For Figure 2 Cross-sectional explanatory view of a sound insulation panel including a base material and a foaming material, illustrating an example of the sound insulation panel; Figure 5 (a) to (c) of Figure 4 Cross-sectional process explanatory view showing the installation process of the sound insulation panel; Figure 6 (a) to (c) of Figure 4 Enlarged top view showing the installation process of the sound insulation panel, (a) is an enlarged top view of the periphery of the opening in the upper side surface of the side beam before installing the sound insulation panel, (b) is an enlarged top view of the state before the foaming material foams after just installing Figure 4 the sound insulation panel, and (c) is an enlarged top view of the state after the foaming material of the sound insulation panel in (b) foams; Figure 7 Graph showing the change in sound reduction volume with respect to the opening ratio in four models: (a) non-porous single-layer structure S1, (b) porous single-layer structure S2, (c) non-porous multi-layer structure S3, and (d) porous multi-layer structure S4; Figure 8 As a model schematically showing the change in the height of the sound insulation panel of this embodiment, the state of changing the height h of the foaming material with respect to the plate having an opening within the flange height H is illustrated in the figure, (a) illustrates the case where h = 0, (b) illustrates the case where 0 < h < H, and (c) illustrates the case where h = H; Figure 9 Graph showing the relationship between the height ratio h / H of the foaming material setting with respect to the flange height H and the sound reduction volume; Figure 10 Showing Figure 11 Column graph of the sound pressure in the sound insulation structure of the comparative example and the sound insulation structure of this embodiment, respectively showing the sound pressure at (I) inside the pillar, (II) near the pillar trim, and (III) the position of the passenger's ear in the vehicle; Figure 11Cross-sectional view of an existing sound insulation structure in which a foaming material directly closes the opening at the upper side surface of a side beam, which is a comparative example of the present invention; Figure 12 In Figure 11 the existing sound insulation structure, a magnified top view of the state in which the foaming material closes the opening at the surface of the upper side surface of the side beam and the inner peripheral surface of the strut reinforcement. Detailed Description of the Invention

[0027] The sound insulation structure of a vehicle frame according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] Figure 1 Front view of the main components of a vehicle body 1 to which the sound insulation structure of a vehicle frame according to an embodiment of the present invention is applied.

[0029] The vehicle body 1 has, on both side portions in the vehicle width direction: side beams 3 extending in the vehicle front-rear direction X, a front pillar 4 (A pillar) extending upward Z1 from the end portion on the vehicle front side X1 of the side beam 3, a center pillar 5 (B pillar) extending upward Z1 at an intermediate position in the vehicle front-rear direction X of the side beam 3, a rear pillar 6 (C pillar) extending upward Z1 from near the end portion on the vehicle rear side X2 of the side beam 3, and a roof rail 7 extending in the vehicle front-rear direction X connecting the upper end portions of these three pillars 4 to 6. A part of the vehicle frame on both side portions in the vehicle width direction is constituted by the above side beams 3, the three pillars 4 to 6, and the roof rail 7.

[0030] In the above vehicle body 1, as Figure 2 shown, the sound insulation structure of the present embodiment is disposed near the joint portion of the lower end portions of the side beam 3 and the center pillar 5.

[0031] The side beam 3 is disposed at the outer side end portion at the bottom of the vehicle cabin 2 of the vehicle and is a hollow member extending in the vehicle front-rear direction X. Specifically, as Figure 2 shown, the side beam 3 includes an outer side beam 3a, an inner side beam 3b located on the inner side Y2 in the vehicle width direction with respect to the outer side beam 3a, and a reinforcing plate 3c between the outer side beam 3a and the inner side beam 3b.

[0032] The outer side beam 3a extends in the vehicle front-rear direction X and has flange portions 3a1, 3a2 at the upper end portion and the lower end portion, and has a hat-shaped cross section. Similarly, the inner side beam 3b also extends in the vehicle front-rear direction X and has flange portions 3b1, 3b2 at the upper end portion and the lower end portion, and has a hat-shaped cross section.

[0033] The side beam 3 has the following structure: the flange portions 3a1, 3a2 on the upper and lower sides of the outer side beam 3a and the flange portions 3b1, 3b2 on the upper and lower sides of the inner side beam 3b are respectively joined to each other, thereby having a hollow closed cross-section 11. The side beam 3 also has an upper side surface portion 12 that constitutes the upper side surface of the closed cross-section 11. An opening portion 17 (refer to Figures 2 - 3 ) is formed in the upper side surface portion 12.

[0034] The longitudinal wall portion 14 extends upward in the Z1 direction from the upper side surface portion 12 of the side beam 3. The longitudinal wall portion 14 of the present embodiment is formed by joining the flange portions 3a1, 3b1 that project upward in the outer side beam 3a and the inner side beam 3b.

[0035] The upper end portion of the reinforcing plate 3c is sandwiched between the two upper flange portions 3a1, 3b1, and the lower end portion is sandwiched between the two lower flange portions 3a2, 3b2, thereby suppressing the deformation of the closed cross-section 11 of the side beam 3 by strengthening it from the inside. Although the side beam 3 of the present embodiment has the reinforcing plate 3c, it may be omitted.

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

[0037] As Figure 2 shown, the pillar reinforcing member 5a is a member that extends in the vertical direction Z. The lower end portion 5c of the pillar reinforcing member 5a is joined to the side beam 3. The pillar reinforcing member 5a has a closed cross-section 13 that extends in the vertical direction Z above the upper side surface portion 12 of the side beam 3. In the present embodiment, in the pillar reinforcing member 5a, the pillar reinforcing member outer member 5a1 and the inner plate 5a2 on the inner side Y2 in the vehicle width direction are joined and integrated, thereby forming the closed cross-section 13.

[0038] The sound insulation panel 15 is disposed separately from the upper side surface portion 12 of the side beam 3 in the upward Z1 direction. Thus, the sound insulation panel 15, together with the upper side surface portion 12, the longitudinal wall portion 14, and the pillar reinforcing member 5a, forms a space portion 16 that extends in the vertical direction Z (refer to Figures 2 - 3 ). Thus, regarding the sound inside the side beam 3 generated when the vehicle is running, through the sound insulation performance of the double walls of the upper side surface portion 12 of the side beam 3, the sound insulation panel 15, and the space portion 16 sandwiched by the above components, the sound that passes through the sound insulation panel 15 and travels upward in the Z1 direction inside the pillar reinforcing member 5a can be reduced.

[0039] The sound insulation panel 15 only needs to close the upper end of the space portion 16 to block or suppress the transmission of sound upward to the space portion 16, and any structure and material can be adopted as long as it has the above structure.

[0040] Specifically, as Figures 4 - 6As shown in the figure, the sound insulation board 15 of the present embodiment includes: a plate-shaped base material 15a having a width capable of closing the upper end of the space portion 16, and a sound absorption material 15b having sound absorption performance such as a foaming material disposed 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 surrounding the main body portion 15a1 at a position one step lower than the outer peripheral edge of the main body portion 15a1.

[0042] The sound absorption material 15b is composed of a foaming material or the like having sound absorption performance, and is disposed around the entire circumference above the annular flange portion 15a2. The sound absorption material 15b only needs to have sound absorption performance, and any material can be used. In addition to the foaming material, it can also be an elastic material such as rubber.

[0043] As shown in Figure 5 Figs. (a) to (c) and Figure 6 Figs. (b), (c), in a state where the sound insulation board 15 is separated and disposed upward Z1 from the upper side surface portion 12 of the side beam 3, in the present embodiment, the sound absorption material 15b including the foaming material closes the gap between the pillar reinforcement 5a and the base material 15a, and the gap between the longitudinal wall portion 14 and the base material 15a. When the vehicle body 1 or the like is heated to dry the electrodeposition liquid described later, the foaming material is heated and foamed, and the volume expands, thereby being able to close the above-mentioned gap.

[0044] The sound insulation board 15 may also have a structure that can be fixed at a certain height position separated upward Z1 from the upper side surface portion 12 of the side beam 3, for example, a convex portion that can be engaged with a concave portion formed in the pillar reinforcement 5a or the like.

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

[0046] The opening portion 17 of the present embodiment is an electrodeposition liquid flow hole that can supply the electrodeposition liquid A (refer to Figure 5 Fig. (b)) to flow in and out (that is, flow in and out) inside and outside the side beam 3.

[0047] As the electrodeposition liquid flow hole, a plurality of opening portions 17 are formed on the inner side portion 12a of the upper side surface portion 12 of the side beam 3 and are separated from each other. For example, as shown in Figure 6 Fig. (a), on the inner side portion 12a, three opening portions 17 are formed separately in the vehicle front-rear direction X.

[0048] After painting the vehicle body 1 for rust prevention purposes, the electrodeposition liquid A is applied to the entire vehicle body 1 by immersing the vehicle body 1 in an electrolyte bath or the like. When the electrodeposition liquid A is to flow into the side beam 3 through the opening 17, as Figure 5 shown in (a), after fixing the sound insulation panel 15 at a certain height position separated from the inner part 12a of the upper side surface portion 12 of the side beam 3 between the pillar reinforcement 5a of the center pillar 5 and the longitudinal wall portion 14, as Figure 5 shown in (b), the sound insulation panel 15 is slightly inclined to form a gap 20 in advance between the sound insulation panel 15 and the longitudinal wall portion 14. Through this gap 20, the electrodeposition liquid A can flow into the side beam 3 through the opening 17.

[0049] After applying the electrodeposition liquid A to the entire vehicle body 1, the inclination of the sound insulation panel 15 is corrected and then the vehicle body 1 is dried in a drying furnace, thereby drying the electrodeposition liquid A. At this time, the sound absorption material 15b including the foaming material of the sound insulation panel 15 foams and expands, thereby being able to close the gaps between the sound insulation panel 15 and the pillar reinforcement 5a, and between the sound insulation panel 15 and the longitudinal wall portion 14.

[0050] Before drying the electrodeposition liquid A, the excess electrodeposition liquid A can also be discharged from the inside of the side beam 3 through the opening 17.

[0051] In order to obtain the sound insulation performance of the double walls of the above upper side surface portion 12, sound insulation panel 15 and space portion 16, it is preferable that the opening area of the opening 17 is set such that the ratio of the opening area to the area of the inner part 12a in the upper side surface portion 12, that is, the opening ratio, is greater than 0 and 0.2 or less.

[0052] Here, in order to verify the above-mentioned set range of the opening ratio, refer to Figure 7 Study the relationship between the opening ratio and the sound reduction volume.

[0053] Figure 7 It is a graph showing the change of the sound reduction volume with respect to the opening ratio in the four models of (a) non-porous single-layer structure S1, (b) porous single-layer structure S2, (c) non-porous multi-layer structure S3, and (d) porous multi-layer structure S4 shown in the figure.

[0054] Here, (a) the non-porous single-layer structure S1 is a structure in which the first layer 32 and the second layer 33 of the same material, the same thickness, and the same mass overlap and are made into a single layer in the cylinder 31 through which sound passes, and the space in the cylinder 31 is separated by it.

[0055] (b) The porous single-layer structure S2 is a structure in which through holes 34 are formed through the overlapping first layer 32 and second layer 33 in (a).

[0056] (c) The non-porous multi-layer structure S3 is a structure in which the first layer 32 and the second layer 33 in (a) are separated in the extending direction of the cylinder 31.

[0057] (d) The perforated multi-layer structure S4 is a structure in which a through-hole 36 penetrating the first layer 32 of (c) is formed.

[0058] According to Figure 7 the chart, in the perforated single-layer structure S2, as the opening ratio of the through-hole 34 decreases, the sound reduction volume increases. After it reaches below 0.2, the gradient of the sound reduction volume becomes larger, and the sound reduction effect further increases, and finally reaches the sound reduction volume of the non-perforated single-layer structure S1.

[0059] It is also known that in the perforated multi-layer structure S4, as the opening ratio of the through-hole 36 penetrating the first layer 32 decreases, the sound reduction volume increases. However, after it reaches below 0.2, the gradient of the sound reduction volume increases sharply compared with that of the perforated single-layer structure S2, and the sound reduction effect further increases, and finally reaches the sound reduction volume of the non-perforated multi-layer structure S3.

[0060] From Figure 7 the results of the chart, it can be seen that in the perforated multi-layer structure S4, if the opening ratio is below 0.2, the sound insulation performance of the double wall that cannot be achieved in the perforated single-layer structure S2 can be exerted, and thus the sound reduction effect further increases.

[0061] In order to ensure the flow performance of the electroplating solution A flowing inside and outside the side beam 3 through the opening 17, it is preferable to set the opening ratio of the above-mentioned opening 17 to 0.003 or more.

[0062] In addition, in order to improve the sound insulation performance, the ratio of the height h of the sound insulation panel 15 to the height H (refer to Figure 5 (c)) of the upper side surface portion 12 of the side beam 3 to the upper end of the longitudinal wall portion 14, that is, the height ratio h / H is preferably set to 0.2 or more and 1 or less, and more preferably set to 0.4 or more.

[0063] Here, in order to verify the set range of the height ratio h / H of the above-mentioned sound insulation panel 15, refer to Figures 8 - 9 to study the relationship between the height ratio and the sound reduction volume.

[0064] In Figure 8 (a) to (c): As a model schematically showing the change in the height of the sound insulation panel 15 of the present embodiment, a model including the following components is illustrated: a first wall 41 corresponding to the strut reinforcement 5a, a second wall 42 having a flange height H corresponding to the longitudinal wall portion 14, a reference plate 43 having an opening 45 corresponding to the inner portion 12a of the upper side surface portion 12 of the side beam 3, and a foaming material 44 separated from the reference plate 43 upward by a height h. Figure 8 In (a) to (c), the state in which the height h of the foaming material 44 relative to the reference plate 43 is changed within the range of the flange height H is illustrated. Specifically, Figure 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, Figure 8 The flange height H in (c) is the distance from the lower side surface of the foaming material 44 to the upper side surface of the reference plate 43 when the upper side surface of the foaming 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 foaming material 44.

[0065] Figure 9 The graph shows the relationship between the height ratio h / H of the foaming material 44 with respect to Figure 8 the flange height H of the second wall 42 and the sound reduction volume.

[0066] From Figure 9 the graph, it can be seen that compared with when the height ratio h / H is less than 0.2, by setting the height ratio h / H to 0.2 or more, the gradient of the sound insulation amount can be increased. Therefore, as long as the height ratio h / H is set to 0.2 or more, the sound insulation performance can be effectively improved.

[0067] Moreover, by setting the height ratio h / H to 0.4 or more, the obtained sound insulation amount exceeds the range with a large sound insulation amount gradient in the range of 0.2 - 0.4, so the sound insulation performance can be further improved.

[0068] Next, using Figure 10 the graph, compare Figure 2 the sound insulation performance of the sound insulation structure of the present embodiment shown in Figures 11 - 12 and the sound insulation structure of the comparative example shown in

[0069] Figures 11 - 12 The sound insulation structure of the comparative example shown in Figure 7 is an existing sound insulation structure in which the foaming material 21 directly closes the opening 17 of the inner part 12a of the upper side surface portion 12 of the side beam 3 (a structure corresponding to the non - porous single - layer structure S1 in Figure 12 (a)). Specifically, as shown in

[0070] Figure 10 the columnar diagram, the foaming material 21 closes the three openings 17 and the inner peripheral surface of the strut reinforcement 5a on the surface of the inner part 12a of the upper side surface portion 12 of the side beam 3. Figure 11 The columnar diagram shows the sound pressure in the sound insulation structure of the comparative example Figure 2 and the sound insulation structure of the present embodiment shown in

[0071] The position close to the pillar trim is close to Figure 6The position on the cabin side of the pillar trim 22 that is located on the inner side Y2 in the vehicle width direction with respect to the longitudinal wall portion 14 as shown in (a).

[0072] From Figure 10 The chart shows that at all positions of (I) inside the pillar, (II) near the pillar trim position, and (III) the position of the ears of the occupants in the vehicle, the sound pressure in the sound insulation structure of the present embodiment is significantly reduced compared to the sound pressure in the sound insulation structure of the comparative example.

[0073] (Features of the present embodiment) (1) The sound insulation structure of the vehicle frame of the present embodiment includes: a side beam 3 having a closed cross-section 11; a pillar reinforcement 5a having a closed cross-section 13 and a lower end portion 5c joined to the side beam 3; a longitudinal wall portion 14 extending upward Z1 from the upper side surface portion 12 of the side beam 3; and a sound insulation panel 15 that is separately disposed upward Z1 from the upper side surface portion 12 and forms a space portion 16 extending in the vertical direction Z together with the upper side surface portion 12, the longitudinal wall portion 14, and the pillar reinforcement 5a. An opening portion 17 penetrating the upper side surface portion 12 is formed in the inner portion 12a of the upper side surface portion 12 that is located inside the space portion 16.

[0074] The opening area of the opening portion 17 is set such that the ratio of the opening area to the area of the inner portion 12a of the upper side surface portion 12, that is, the opening ratio, is 0.2 or less (greater than 0).

[0075] In the above structure, the opening ratio of the opening portion 17 of the upper side surface portion 12 of the side beam 3 is set to 0.2 or less. Thus, regarding the running sound propagating in the side beam 3, the penetrating sound penetrating the upper side surface portion 12 of the side beam 3 is more dominant than the sound entering the space portion 16 through the opening portion 17. Therefore, sufficient double-wall sound insulation performance can be obtained through the sound insulation panel 15 and the upper side surface portion 12 of the side beam 3. Thus, the holes in the upper side surface portion 12 of the side beam 3 can be ensured and the sound insulation performance can be improved by providing fewer sound insulation panels 15. (2) In the sound insulation structure of the vehicle frame of the present embodiment, the opening ratio is set to 0.003 or more. Thus, the circulation performance that allows the electrodeposition liquid entering the inside of the side beam 3 through the opening portion 17 during vehicle manufacturing to flow inside and outside the side beam 3 can be ensured. (3) In the sound insulation structure of the vehicle frame according to this embodiment, the sound insulation panel 15 includes a plate-shaped base material 15a and a sound absorption material 15b having sound absorption performance, such as a foaming material, disposed on the periphery of the base material 15a. The sound absorption material 15b closes the gap between the pillar reinforcing member 5a and the base material 15a, and the gap between the longitudinal wall portion 14 and the base material 15a. By closing the gap between the pillar reinforcing member 5a and the base material 15a, and the gap between the longitudinal wall portion 14 and the base material 15a with the sound absorption material 15b, sound insulation can be effectively achieved. (4) In the sound insulation structure of the vehicle frame according to this embodiment, the opening 17 is an electrodeposition liquid circulation hole that allows the electrodeposition liquid to flow inside and outside the side beam 3. A plurality of openings 17 serving as electrodeposition liquid circulation holes are formed separately from each other in the inner portion 12a of the upper side face portion 12. In this structure, the performance (so-called circulation performance) that allows the electrodeposition liquid used for rust prevention, etc. to flow inside and outside the side beam 3 through the opening 17 can be ensured. (5) In the sound insulation structure of the vehicle frame according to this embodiment, the height ratio h / H is set to 0.2 or more and 1 or less. This height ratio h / H is the ratio of the height h to the height H from the upper side face portion 12 of the side beam 3 to the upper end of the longitudinal wall portion 14. Thus, compared with when the height ratio h / H is less than 0.2, the gradient of the sound insulation amount can be increased, and the sound insulation performance can be effectively improved. (6) In the sound insulation structure of the vehicle frame according to this embodiment, the height ratio h / H is set to 0.4 or more. According to this structure, the obtained sound insulation amount exceeds the range where the sound insulation amount gradient is large in the range of the height ratio h / H of 0.2 to 0.4, and the sound insulation performance can be further improved. (7) In the sound insulation structure of the vehicle frame according to this embodiment, the side beam 3 includes an outer side beam 3a and an inner side beam 3b located on the inner side Y2 in the vehicle width direction with respect to the outer side beam 3a. The outer side beam 3a and the inner side beam 3b extend in the vehicle front-rear direction X, and have flange portions 3a1, 3b1, 3a2, 3b2 at their respective upper and lower ends, and the cross section is in a hat shape. The side beam 3 is formed by joining the flange portions 3a1, 3b1, 3a2, 3b2 of the outer side beam 3a and the inner side beam 3b to each other. The longitudinal wall portion 14 is formed by the flange portions 3a1, 3b1 that project upward in the outer side beam 3a and the inner side beam 3b.

[0082] In this structure, it is possible to adopt an existing side beam 3 having an outer side beam 3a and an inner side beam 3b with a hat-shaped cross section. Therefore, the versatility of this sound insulation structure is high, and the manufacturing cost can be suppressed.

[0083] (Deformation example) (A) In the above-described embodiment, as an example of the longitudinal wall portion extending upward from the side beam, it is illustrated that the longitudinal wall portion 14 is constituted by flange portions 3a1 and 3b1 protruding upward in the outer side beam 3a and the inner side beam 3b having a hat-shaped cross section, respectively. However, the present invention is not limited thereto, and any longitudinal wall portion extending upward from the side beam may be used. For example, the present invention also includes a method of installing a longitudinal wall portion extending upward on the upper side surface of a side beam having a closed cross section by welding or the like, or a method of integrally forming a side beam having a longitudinal wall portion.

[0084] (B) In the above-described embodiment, as an example of the opening portion of the present invention, the opening portion 17 used as an electrolyte flow hole is illustrated, but the present invention is not limited thereto. The opening portion of the present invention may be any opening portion formed in the inner portion of the space portion between the pillar reinforcing member and the longitudinal wall portion in the upper side surface of the side beam, and may be used for any purpose. For example, a hole through which a cable or the like passes is also included in the opening portion of the present invention.

[0085] (C) In the above-described embodiment, as an example of the pillar reinforcing member, the pillar reinforcing member 5a of the center pillar 5 is illustrated, but the present invention is not limited thereto, and any pillar having a pillar reinforcing member that is joined to the side beam and has a closed cross section extending upward from the side beam may be used, and it may also be a pillar reinforcing member in the front pillar or the rear pillar.

[0086]

Number Explanation

Claims

1. A sound insulation structure for a vehicle frame, characterized in that have: A side member disposed at an outer side end portion of a bottom portion of a cabin of the vehicle and having a closed section extending in the front-rear direction of the vehicle and an upper side portion constituting an upper side of the closed section; a pillar reinforcement having a lower end portion joined to the side member and a closed cross section extending in the up-down direction above the upper side portion; A longitudinal wall portion extending upward from the upper side portion; The sound insulation board is separated and arranged upward from the upper side portion, and forms a space portion extending in the up-down direction together with the upper side portion, the vertical wall portion and the pillar reinforcement member; wherein, An opening portion penetrating the upper side portion is formed in an inner portion of the upper side portion located inside the space portion. The opening area of ​​the opening portion is set to be a ratio of the opening area to the area of ​​the inner portion of the upper side portion, that is, an opening ratio of 0.2 or less.

2. The sound insulation structure of the vehicle frame according to claim 1, characterized in that: The aperture ratio is set to be greater than or equal to 0.

003.

3. The sound insulation structure of a vehicle frame according to claim 1, characterized in that: The sound insulation board comprises a plate-shaped base material and a sound absorbing material having sound absorbing performance arranged on the periphery of the base material. The sound absorbing material closes a gap between the pillar reinforcement and the base material, and a gap between the vertical wall portion and the base material.

4. The sound insulation structure of a vehicle frame according to claim 1, characterized in that: The opening is an electrodeposition liquid flow hole that allows the electrodeposition liquid to flow into and out of the side beam. In the inner portion of the upper side portion, a plurality of the electrodeposition liquid flow holes are formed to be separated from each other.

5. The sound insulation structure of a vehicle frame according to any one of claims 1 to 4, characterized in that: The height ratio is set to be not less than 0.2 and not more than 1, and the height ratio is a ratio of the height to the soundproof board to the height to the upper end of the vertical wall portion based on the upper side portion of the side member.

6. The sound insulation structure of a vehicle frame according to claim 5, characterized in that: The height ratio is set to be greater than 0.

4.

7. The sound insulation structure of a vehicle frame according to any one of claims 1 to 4, characterized in that: The side beam includes an outer beam and an inner beam located inward in the vehicle width direction relative to the outer beam. The outer beam and the inner beam extend in the front-rear direction of the vehicle, have flanges at their upper and lower ends, and have a hat-shaped cross section. The side beam is formed by mutually joining flange portions of the outer beam and the inner beam. The vertical wall portion is constituted by the flange portion protruding upward in the outer beam and the inner beam.

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