JP2018188012A - Vehicle lower part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle lower part structure capable of restraining deformation even with a small number of components by enhancing the strength and stiffness of a side member into which a load from a suspension is input.SOLUTION: On both side parts to which a vehicle lower part structure 1 is applied, a pair of side members 2 are arranged. A cross member 3 is provided between the pair of side members 2. Between the pair of side members 2 and both ends of the cross member 3, a cross member extension 4 is attached. An undersurface 31 of the cross member 3 is positioned above undersurfaces 21 of the pair of side members 2. A pair of trailing arm support parts 5 are fixed on the pair of side members 2. Each cross member extension 4 includes a vertical wall part 44 overlapped on an inner side face 22 of the side member 2 in the vehicle width direction by being bent downward at an end of adjacent side member 2 side and an inclined face part 42 formed by smoothly connecting the undersurface 31 of the cross member 3 with the undersurface 21 of the side member 2.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle lower structure.

  A vehicle lower structure in which a suspension called a “torsion beam suspension” is attached to the rear of the lower part of the vehicle is already known (see, for example, Patent Document 1). In this torsion beam suspension, a pair of trailing arms extending in the vehicle front-rear direction is disposed on both sides of the vehicle, and the pair of trailing arms are connected by a torsion beam extending in the vehicle width direction. The front ends of the pair of trailing arms are attached to side sills and side members disposed on both sides of the vehicle via a trailing arm support portion such as a bracket.

JP 2013-18383 A

  In the vehicle lower structure described above, since a large load is input to the trailing arm support portion and the vicinity thereof, in order to suppress deformation of the part with a small number of parts, the strength and rigidity of the part are well balanced. In this respect, the conventional vehicle substructure has room for improvement.

  The present invention has been made from such a viewpoint, and it is an object to provide a vehicle lower structure capable of suppressing deformation by increasing the strength and rigidity of a side member to which a load from a suspension is input with a small number of parts. To do.

  In the vehicle lower structure of the present invention, a pair of side members extending in the vehicle front-rear direction is disposed on both sides of the vehicle, and a cross member extending in the vehicle width direction is disposed between the pair of side members. In the vehicle lower part structure in which the side member and the both ends of the cross member are respectively connected by a cross member extension, and the lower surface of the cross member is positioned above the lower surfaces of the pair of side members, A pair of cross member extensions, which are bent downward at the end on the side member side adjacent to each other and overlapped with the inner side surface of the side member in the vehicle width direction, the lower surface of the cross member, and the side member It has the inclined surface part which connected the lower surface of this smoothly.

  According to the vehicle lower structure of the present invention, the strength and rigidity of the side member to which the load from the suspension is input can be increased and the deformation of the side member can be suppressed with a small number of parts.

It is a bottom view of the vehicle to which the vehicle lower part structure concerning the Example of this invention was applied. FIG. 2 is an enlarged view of a portion D in FIG. 1 (rear suspension is omitted). It is sectional drawing along the AA line in FIG. It is sectional drawing along the BB line in FIG. It is a perspective view of the D section of Drawing 1 (a rear suspension is omitted). FIG. 6 is a bottom view of the portion of FIG. 5 (rear suspension is omitted).

  In the present invention, a pair of side members extending in the vehicle front-rear direction is disposed on both sides of the vehicle, a cross member extending in the vehicle width direction is disposed between the pair of side members, and the pair of side members and the cross member In the vehicle lower structure in which the two end portions are respectively connected by a cross member extension, and the lower surface of the cross member is positioned above the lower surfaces of the pair of side members, the pair of cross member extensions are connected to adjacent side members. A vertical wall portion bent downward at the end portion on the member side and overlaid on the inner side surface in the vehicle width direction of the side member, and an inclined surface portion smoothly connecting the lower surface of the cross member and the lower surface of the side member. It is the vehicle lower structure characterized by having carried out.

  According to the above configuration, the strength of the side member is increased by overlapping the vertical wall portion on the inner side surface in the vehicle width direction of the side member, and the cross-sectional deformation of the side member due to the vehicle vertical direction load input from the suspension is suppressed. be able to. In addition, since the inclined surface portion smoothly connects the lower surface of the cross member and the lower surface of the side member, the rigidity of the side member is enhanced, and the cross-sectional deformation of the side member due to the vehicle lateral load input from the suspension is suppressed. be able to. As described above, the vehicle lower structure according to the present invention can reinforce the strength and rigidity of the side member to which the load from the suspension is input in a well-balanced manner, so that the deformation of the side member can be suppressed with a small number of parts. .

  Embodiments of the present invention will be described below with reference to the drawings. The vehicle lower structure 1 of the present embodiment shown in FIGS. 1 to 6 is applied to an automobile. In addition, an arrow FRONT in the figure represents the front in the vehicle longitudinal direction, the arrow IN represents the inward in the vehicle width direction, and the arrow UP represents the upper in the vehicle vertical direction.

  FIG. 1 is a bottom view of a vehicle 10 to which a vehicle lower structure 1 according to an embodiment of the present invention is applied. In FIG. 1, reference numeral 2 denotes a side member. Reference numeral 2L denotes a side member arranged on the left side of the vehicle 10, and reference numeral 2R denotes a side member arranged on the right side of the vehicle 10. In the present specification, the “left side of the vehicle 10” means the left side of the vehicle 10 as viewed from the driver. Similarly, the “right side of the vehicle 10” means the right side of the vehicle 10 as viewed from the driver. Reference numeral 3 denotes a cross member. Reference numeral 4 denotes a cross member extension. Reference numeral 4L denotes a cross member extension arranged on the left side of the vehicle 10, and reference numeral 4R denotes a cross member extension arranged on the right side of the vehicle 10.

  In FIG. 1, reference numeral 7 denotes a rear suspension. Reference numeral 71 denotes a torsion beam constituting the rear suspension 7. Reference numeral 72 denotes a trailing arm constituting the rear suspension 7. Reference numeral 73 denotes a spring mounting portion for mounting a spring of the rear suspension 7. Reference numeral 74 denotes a bracket for mounting the shock absorber of the rear suspension 7.

  In FIG. 1, reference numeral 5 denotes a trailing arm support portion that supports the front end portion 72 a of the trailing arm 72. Reference numeral 5 </ b> L is a trailing arm support portion disposed on the left side of the vehicle 10, and reference numeral 5 </ b> R is a trailing arm support portion disposed on the right side of the vehicle 10. Reference numeral 6 denotes a reinforcing member for the trailing arm support 5. Reference numeral 6L denotes a reinforcing member arranged on the left side of the vehicle 10, and reference numeral 6R denotes a reinforcing member arranged on the right side of the vehicle 10.

  In FIG. 1, the code | symbol 9 is a side sill. Reference numeral 9 </ b> L is a side sill disposed on the left side of the vehicle 10, and reference numeral 9 </ b> R is a side sill disposed on the right side of the vehicle 10. Reference numeral 11 denotes a main floor panel.

  As shown in FIG. 1, a pair of side sills 9L and 9R extending in the vehicle front-rear direction are disposed on both sides of the vehicle 10, and the vehicle sill extends in the vehicle front-rear direction inside the pair of side sills 9L and 9R. A pair of side members 2L and 2R are arranged. A cross member 3 extending in the vehicle width direction is disposed between the pair of side members 2L and 2R and below the rear floor panel 11. A pair of side members 2L, 2R and both ends of the cross member 3 are connected by cross member extensions 4L, 4R, respectively. The pair of trailing arm support portions 5 </ b> L and 5 </ b> R is disposed on an extension line of both ends of the cross member 3 and is disposed in a space provided between the rear end of the side sill 9 and the side member 2. The reinforcing members 6L and 6R are arranged on the inner side in the vehicle width direction of the trailing arm support portions 5L and 5R. Further, the torsion beam 71 is disposed behind the cross member 3. 3 and 4, the lower surface 31 of the cross member 3 is located above the lower surfaces 21 of the pair of side members 2L and 2R.

  The pair of side members 2L and 2R are formed by pressing a metal plate. As shown in FIGS. 3 and 4, the pair of side members 2 </ b> L and 2 </ b> R includes a lower surface 21, an inner surface 22 bent upward at an inner end in the vehicle width direction of the lower surface 21, and an outer side in the vehicle width direction of the lower surface 21. And an outer surface 23 bent upward at the end, and is formed in a U-shaped cross section. The upper end portion of the inner side surface 22 and the upper end portion of the outer side surface 23 are welded to the floor side panel 13 connected to the side of the rear floor panel 11.

  The cross member 3 is formed by pressing a metal plate. As shown in FIGS. 2 and 5, the cross member 3 includes a lower surface 31 facing the floor panel 11, a front side surface 32 bent upward at the front end portion of the lower surface 31, and an upper portion at the rear end portion of the lower surface 31. The rear side surface 33 is bent and the joint portions 34 and 35 are welded to the floor panel 11.

  Since the pair of cross member extensions 4L and 4R has a bilaterally symmetrical shape, the configuration of the cross member extension 4R will be described as a representative. The cross member extension 4R is formed by pressing a metal plate. As shown in FIGS. 4 and 5, the cross member extension 4 </ b> R includes a cross member joint portion 41, a side member joint portion 45, an inclined surface portion 42, a second inclined surface portion 43, a vertical wall portion 44, and a front side surface 46. And a rear side surface 47 and floor panel joint portions 48 and 49.

  The cross member joint portion 41 is a portion that is overlapped and welded to the outer end portion in the vehicle width direction of the lower surface 31 of the cross member 3. The side member joint portion 45 is a portion that is overlapped and welded to the lower surface 21 of the adjacent side member 2R.

  The inclined surface portion 42 is an inclined surface that smoothly connects the cross member joint portion 41 and the side member joint portion 45. The end of the inclined surface portion 42 on the side member 2R side is located at the inner end in the vehicle width direction on the lower surface 21 of the side member 2R. That is, the inclined surface portion 42 smoothly connects the lower surface 31 of the cross member 3 and the lower surface 21 of the side member 2R.

  The second inclined surface portion 43 is an inclined surface that continues to the cross member joint portion 41 and extends to the inner side surface 22 of the side member 2R. An end of the second inclined surface portion 43 on the side member 2R side is located above the lower surface 21 of the side member 2R. The second inclined surface portion 43 is adjacent to the inclined surface portion 42 in the vehicle front-rear direction, and is located behind the inclined surface portion 42. The inclined surface portion 42 and the second inclined surface portion 43 are inclined in a downward direction as they approach the side member 2R side from the cross member joint portion 41. These inclination angles are different, and the inclination angle of the inclined surface portion 42 is larger than the inclination angle of the second inclined surface portion 43.

  The vertical wall portion 44 is bent downward at the end portion of the second inclined surface portion 43 on the side member 2R side, and extends to the lower surface 21 of the side member 2R. The vertical wall portion 44 is overlapped and welded to the inner side surface 22 of the side member 2R. The vertical wall portion 44 is adjacent to the inclined surface portion 42 in the vehicle front-rear direction, and is located behind the inclined surface portion 42. Further, the vertical wall portion 44 connects the second inclined surface portion 43 and the side member joint portion 45.

  The side member joint portion 45 is bent outward in the vehicle width direction at the end portions of the inclined surface portion 42 and the vertical wall portion 44. The side member joint 45 extends from the inner end in the vehicle width direction on the lower surface 21 of the side member 2R to the center in the vehicle width direction on the lower surface 21.

  The front side surface 46 is a portion bent upward at the front end portions of the cross member joint portion 41 and the inclined surface portion 42. The rear side surface 47 is a portion bent upward at the rear end portions of the cross member joint portion 41 and the second inclined surface portion 43.

  The floor panel joint portion 48 is bent forward at the upper end portion of the front side surface 46 and is overlapped and welded to the floor panel 11. The floor panel joint portion 49 is bent backward at the upper end portion of the rear side surface 47 and is overlapped and welded to the floor panel 11.

  As shown in FIG. 6, the ridge line formed at the front end of the lower surface of the cross member extension 4R is along the inclined surface portion 42 described above, and this ridge line is continuous with the ridge line formed at the front end of the lower surface 31 of the cross member 3. ing. The ridge line at the front end of the lower surface 31 of the continuous cross member 3 and the ridge line at the front end of the lower surface of the cross member extension 4R are denoted by reference symbol L1. The ridge line L1 intersects with the ridge line L2 formed at the inner end in the vehicle width direction on the lower surface 21 of the side member 2R. That is, the lower surface front portion of the cross member extension 4R having the inclined surface portion 42 connects the lower surface 31 of the cross member 3 and the lower surface 21 of the side member 2R. Further, the ridge line formed at the rear end of the lower surface of the cross member extension 4 </ b> R is continuous with the ridge line formed at the rear end of the lower surface 31 of the cross member 3. The ridge line at the rear end of the lower surface 31 of the continuous cross member 3 and the ridge line at the rear end of the lower surface of the cross member extension 4R are denoted by reference numeral L3.

  Since the pair of trailing arm support portions 5L and 5R have a bilaterally symmetrical shape, the configuration of the trailing arm support portion 5R will be described as a representative. As shown in FIG. 4, the trailing arm support portion 5R includes an inner bracket 51 welded to the outer surface 23 of the side member 2R and an outer bracket 54 welded to the side sill 9R. The outer bracket 54 includes a facing portion 52 that faces the inner bracket 51 with a space therebetween, and a connecting portion 53 that combines the facing portion 52 and the inner bracket 51. The trailing arm 72 has a front end portion 72a disposed between the inner bracket 51 and the facing portion 52, and is supported by the trailing arm support portion 5 so as to be slidable.

  Since the pair of reinforcing members 6L and 6R have a symmetrical shape, the configuration of the reinforcing member 6R will be described as a representative. The reinforcing member 6R is formed by pressing a metal plate. As shown in FIG. 5, the reinforcing member 6R includes an inner bracket joint surface 61 welded to an inner portion in the vehicle width direction of the inner bracket 51 of the trailing arm support portion 5R, a flange portion 63, an inner reinforcing portion 62, It has a front reinforcing part 64 and a side member joint part 65.

  The inner bracket joint surface 61 is preferably arranged so that at least a part of the longitudinal wall portion 44 of the cross member extension 4R overlaps with the vehicle front-rear direction when viewed from the side of the vehicle. It is arranged so that almost the whole area overlaps.

  The flange portion 63 is a portion that is overlapped and welded to the vertical wall portion 44 of the cross member extension 4R. That is, at the E portion in FIG. 4, the inner side surface 22 of the side member 2R, the vertical wall portion 44 of the cross member extension 4R, and the flange portion 63 of the reinforcing member 6R are sequentially stacked and welded.

  The inner reinforcing portion 62 is a portion extending from the rear end of the inner bracket joint surface 61 to the flange portion 63. The inner reinforcing portion 62 is disposed in the vicinity of the rear end on the lower surface of the cross member extension 4R. As shown in FIG. 6, the inner reinforcing portion 62 is formed with a ridge line L4 that intersects with the ridge line L2 inside the lower surface 21 of the side member 2R. The ridge line L4 of the inner reinforcing portion 62 is located on the extended line of the ridge line L3 at the rear end of the lower surface of the cross member 3 and the cross member extension 4R when viewed from the bottom surface side of the vehicle 10.

  The front reinforcing portion 64 extends forward from the front end of the inner bracket joint surface 61 to the lower surface 21 of the side member 2R. The front end of the front reinforcing portion 64 is positioned on an extension line of the ridge line L1 at the front end of the lower surface of the cross member 3 and the cross member extension 4R. That is, as shown in FIG. 6, a ridge line L5 that intersects the lower surface 21 of the side member 2R is formed in the front reinforcing portion 64, and the front ends of the ridge line L5 are the lower surface front ends of the cross member 3 and the cross member extension 4R. It is located on the extended line of the ridgeline L1. The front reinforcing portion 64 is preferably arranged so that at least a part of the inclined surface portion 42 of the cross member extension 4R overlaps in the vehicle front-rear direction when viewed from the side of the vehicle. Are arranged to overlap.

  The side member joining portion 65 is continuous with the upper end of the inner bracket joining surface 61, the upper end of the inner reinforcing portion 62, and the upper end of the front reinforcing portion 64. The side member joint 65 is overlapped with and welded to the lower surface 21 of the side member 2R and the side member joint 45 of the cross member extension 4R.

  Further, as shown in FIG. 5, a reinforcing member 8 is provided inside the side member 2R so as to connect the ridge line L1 of the cross member extension 4R and the front reinforcing portion 64 of the reinforcing member 6R. Similarly, the reinforcing member 8 is provided inside the side member 2L so as to connect the ridgeline L1 of the cross member extension 4L and the front side reinforcing portion 64 of the reinforcing member 6L.

  According to the vehicle lower structure 1 configured as described above, the vehicle vertical load input to the trailing arm support portions 5L and 5R is received by the inner side surfaces 22 of the side members 2L and 2R via the reinforcing members 6L and 6R. Can do. The strength of the inner side surface 22 is increased by overlapping the vertical wall portions 44 of the cross member extensions 4L and 4R and the flange portions 63 of the reinforcing members 6L and 6R in the vicinity of the trailing arm support portions 5L and 5R. . Therefore, it is possible to suppress the cross-sectional deformation of the side members 2L and 2R due to the vehicle vertical load input to the trailing arm support portions 5L and 5R. Further, the inclined surface portions 42 of the cross member extensions 4L and 4R smoothly connect the lower surface 31 of the cross member 3 and the lower surface 21 of the side members 2L and 2R. As a result, the rigidity of the side members 2L and 2R can be increased, and the cross-sectional deformation of the side members 2L and 2R due to the vehicle left-right load input to the trailing arm support portions 5L and 5R can be suppressed.

  Thus, according to the vehicle lower structure 1, the strength of the side members 2L and 2R can be increased with a small number of parts while increasing the rigidity of the side members 2L and 2R, that is, the rigidity of the vehicle body. Therefore, it is possible to effectively suppress the side members 2L and 2R from being deformed by the load in the vehicle up-down direction or the vehicle left-right direction input to the trailing arm support portions 5L, 5R during traveling.

  Further, as described above, in the vehicle lower structure 1, the reinforcing members 6L and 6R are coupled to the inside of the trailing arm support portions 5L and 5R in the vehicle width direction, and the reinforcing members 6L and 6R are connected to the side members 2L and 2R. A flange portion 63 is provided on the side wall 22 and the vertical wall portions 44 of the cross member extensions 4L and 4R. Thus, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the vertical wall portion 44. That is, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the portion whose strength is increased by the vertical wall portion 44 of the inner side surface 22, and the side members 2L and 2R are deformed. It can be effectively suppressed.

  Further, in the vehicle lower structure 1, as described above, the reinforcing members 6L and 6R have the inner reinforcing portion 62 extending from the inner bracket joint surface 61 to the flange portion 63, and the inner reinforcing portion 62 is the cross member extension 4L. , 4R is disposed near the rear end of the lower surface of 4R. The vertical wall portion 44 described above is provided at the rear end of the lower surface of the cross member extensions 4L and 4R. As a result, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the portion whose strength is increased by the vertical wall portion 44 of the inner side surface 22, and the side members 2L and 2R are deformed. This can be effectively suppressed.

  In the vehicle lower structure 1, as described above, the reinforcing members 6L and 6R have the front reinforcing portion 64 that extends forward from the inner bracket joint surface 61 to the lower surface 21 of the side members 2L and 2R. And the front end of the front side reinforcement part 64 is located on the extension line of the ridgeline L1 formed in the front end in the lower surface of cross member extension 4L, 4R. As a result, the rigidity of the side members 2L and 2R can be increased, and the cross-sectional deformation of the side members 2L and 2R due to the vehicle left-right load input to the trailing arm support portions 5L and 5R can be suppressed. Furthermore, the rigidity of the side members 2L and 2R, that is, the rigidity of the vehicle body can be increased, and the rigidity of the trailing arm support portions 5L and 5R can be increased, so that the operability can be improved.

  In the embodiment described above, the vertical wall portion 44 of the cross member extensions 4L and 4R and the flange portion 63 of the reinforcing members 6L and 6R are provided in the vicinity of the trailing arm support portions 5L and 5R on the inner surface 22 of the side members 2L and 2R. It was piled up. In the present invention, it is more preferable that the three sheet metals of the inner side surface 22, the vertical wall portion 44, and the flange portion 63 are overlapped as described above, but the flange portion 63 is overlapped on the vertical wall portion 44. Is not an essential configuration, and it is sufficient that at least the vertical wall portion 44 overlaps the inner side surface 22. Even in this case, the strength of the inner side surface 22 can be increased, and the cross-sectional deformation of the side members 2L and 2R can be suppressed.

  Further, in the above-described embodiment, the inclined surface portion 42 and the vertical wall portion 44 are adjacent to each other in the vehicle front-rear direction, and the vertical wall portion 44 is located behind the inclined surface portion 42. The wall portion 44 may be positioned in front of the inclined surface portion 42. In that case, the positional relationship between the inner reinforcing portion 62 and the front reinforcing portion 64 may be reversed, and the inner reinforcing portion 62 may be disposed near the front end on the lower surface of the cross member extension 4R.

  The best configuration, method, and the like for carrying out the present invention have been disclosed above, but the present invention is not limited to this. That is, although the present invention has been particularly illustrated and described with respect to particular embodiments, it will be understood that the present invention is not limited in shape to the embodiments described above without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations. Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

DESCRIPTION OF SYMBOLS 1 Vehicle lower structure 2 Side member 3 Cross member 4 Cross member extension 5 Trailing arm support part 21 Lower surface of side member 22 Inner side surface of sad member 31 Lower surface of cross member 42 Inclined surface part 44 Vertical wall part

  The present invention relates to a vehicle lower structure.

  A vehicle lower structure in which a suspension called a “torsion beam suspension” is attached to the rear of the lower part of the vehicle is already known (see, for example, Patent Document 1). In this torsion beam suspension, a pair of trailing arms extending in the vehicle front-rear direction is disposed on both sides of the vehicle, and the pair of trailing arms are connected by a torsion beam extending in the vehicle width direction. The front ends of the pair of trailing arms are attached to side sills and side members disposed on both sides of the vehicle via a trailing arm support portion such as a bracket.

JP 2013-18383 A

  In the vehicle lower structure described above, since a large load is input to the trailing arm support portion and the vicinity thereof, in order to suppress deformation of the part with a small number of parts, the strength and rigidity of the part are well balanced. In this respect, the conventional vehicle substructure has room for improvement.

  The present invention has been made from such a viewpoint, and it is an object to provide a vehicle lower structure capable of suppressing deformation by increasing the strength and rigidity of a side member to which a load from a suspension is input with a small number of parts. To do.

  In the vehicle lower structure of the present invention, a pair of side members extending in the vehicle front-rear direction is disposed on both sides of the vehicle, and a cross member extending in the vehicle width direction is disposed between the pair of side members. In the vehicle lower part structure in which the side member and the both ends of the cross member are respectively connected by a cross member extension, and the lower surface of the cross member is positioned above the lower surfaces of the pair of side members, A pair of cross member extensions, which are bent downward at the end on the side member side adjacent to each other and overlapped with the inner side surface of the side member in the vehicle width direction, the lower surface of the cross member, and the side member It has the inclined surface part which connected the lower surface of this smoothly.

  According to the vehicle lower structure of the present invention, the strength and rigidity of the side member to which the load from the suspension is input can be increased and the deformation of the side member can be suppressed with a small number of parts.

It is a bottom view of the vehicle to which the vehicle lower part structure concerning the Example of this invention was applied. FIG. 2 is an enlarged view of a portion D in FIG. 1 (rear suspension is omitted). It is sectional drawing along the AA line in FIG. It is sectional drawing along the BB line in FIG. It is a perspective view of the D section of Drawing 1 (a rear suspension is omitted). FIG. 6 is a bottom view of the portion of FIG. 5 (rear suspension is omitted).

  In the present invention, a pair of side members extending in the vehicle front-rear direction is disposed on both sides of the vehicle, a cross member extending in the vehicle width direction is disposed between the pair of side members, and the pair of side members and the cross member In the vehicle lower structure in which the two end portions are respectively connected by a cross member extension, and the lower surface of the cross member is positioned above the lower surfaces of the pair of side members, the pair of cross member extensions are connected to adjacent side members. A vertical wall portion bent downward at the end portion on the member side and overlaid on the inner side surface in the vehicle width direction of the side member, and an inclined surface portion smoothly connecting the lower surface of the cross member and the lower surface of the side member. It is the vehicle lower structure characterized by having carried out.

  According to the above configuration, the strength of the side member is increased by overlapping the vertical wall portion on the inner side surface in the vehicle width direction of the side member, and the cross-sectional deformation of the side member due to the vehicle vertical direction load input from the suspension is suppressed. be able to. In addition, since the inclined surface portion smoothly connects the lower surface of the cross member and the lower surface of the side member, the rigidity of the side member is enhanced, and the cross-sectional deformation of the side member due to the vehicle lateral load input from the suspension is suppressed. be able to. As described above, the vehicle lower structure according to the present invention can reinforce the strength and rigidity of the side member to which the load from the suspension is input in a well-balanced manner, so that the deformation of the side member can be suppressed with a small number of parts. .

  Embodiments of the present invention will be described below with reference to the drawings. The vehicle lower structure 1 of the present embodiment shown in FIGS. 1 to 6 is applied to an automobile. In addition, an arrow FRONT in the figure represents the front in the vehicle longitudinal direction, the arrow IN represents the inward in the vehicle width direction, and the arrow UP represents the upper in the vehicle vertical direction.

  FIG. 1 is a bottom view of a vehicle 10 to which a vehicle lower structure 1 according to an embodiment of the present invention is applied. In FIG. 1, reference numeral 2 denotes a side member. Reference numeral 2L denotes a side member arranged on the left side of the vehicle 10, and reference numeral 2R denotes a side member arranged on the right side of the vehicle 10. In the present specification, the “left side of the vehicle 10” means the left side of the vehicle 10 as viewed from the driver. Similarly, the “right side of the vehicle 10” means the right side of the vehicle 10 as viewed from the driver. Reference numeral 3 denotes a cross member. Reference numeral 4 denotes a cross member extension. Reference numeral 4L denotes a cross member extension arranged on the left side of the vehicle 10, and reference numeral 4R denotes a cross member extension arranged on the right side of the vehicle 10.

  In FIG. 1, reference numeral 7 denotes a rear suspension. Reference numeral 71 denotes a torsion beam constituting the rear suspension 7. Reference numeral 72 denotes a trailing arm constituting the rear suspension 7. Reference numeral 73 denotes a spring mounting portion for mounting a spring of the rear suspension 7. Reference numeral 74 denotes a bracket for mounting the shock absorber of the rear suspension 7.

  In FIG. 1, reference numeral 5 denotes a trailing arm support portion that supports the front end portion 72 a of the trailing arm 72. Reference numeral 5 </ b> L is a trailing arm support portion disposed on the left side of the vehicle 10, and reference numeral 5 </ b> R is a trailing arm support portion disposed on the right side of the vehicle 10. Reference numeral 6 denotes a reinforcing member for the trailing arm support 5. Reference numeral 6L denotes a reinforcing member arranged on the left side of the vehicle 10, and reference numeral 6R denotes a reinforcing member arranged on the right side of the vehicle 10.

In FIG. 1, the code | symbol 9 is a side sill. Reference numeral 9 </ b> L is a side sill disposed on the left side of the vehicle 10, and reference numeral 9 </ b> R is a side sill disposed on the right side of the vehicle 10. Reference numeral 11 denotes a rear floor panel.

  As shown in FIG. 1, a pair of side sills 9L and 9R extending in the vehicle front-rear direction are disposed on both sides of the vehicle 10, and the vehicle sill extends in the vehicle front-rear direction inside the pair of side sills 9L and 9R. A pair of side members 2L and 2R are arranged. A cross member 3 extending in the vehicle width direction is disposed between the pair of side members 2L and 2R and below the rear floor panel 11. A pair of side members 2L, 2R and both ends of the cross member 3 are connected by cross member extensions 4L, 4R, respectively. The pair of trailing arm support portions 5 </ b> L and 5 </ b> R is disposed on an extension line of both ends of the cross member 3 and is disposed in a space provided between the rear end of the side sill 9 and the side member 2. The reinforcing members 6L and 6R are arranged on the inner side in the vehicle width direction of the trailing arm support portions 5L and 5R. Further, the torsion beam 71 is disposed behind the cross member 3. 3 and 4, the lower surface 31 of the cross member 3 is located above the lower surfaces 21 of the pair of side members 2L and 2R.

  The pair of side members 2L and 2R are formed by pressing a metal plate. As shown in FIGS. 3 and 4, the pair of side members 2 </ b> L and 2 </ b> R includes a lower surface 21, an inner surface 22 bent upward at an inner end in the vehicle width direction of the lower surface 21, and an outer side in the vehicle width direction of the lower surface 21. And an outer surface 23 bent upward at the end, and is formed in a U-shaped cross section. The upper end portion of the inner side surface 22 and the upper end portion of the outer side surface 23 are welded to the floor side panel 13 connected to the side of the rear floor panel 11.

The cross member 3 is formed by pressing a metal plate. Cross member 3, as shown in FIG. 2 and 5, a rear floor panel 11 and the opposing lower surface 31, a side surface 32 before the bent upwards at a front end portion of the lower surface 31 at the rear end portion of the lower surface 31 the side surface 33 after being bent upward, and a joint portion 34, 35 welded to the rear floor panel 11.

  Since the pair of cross member extensions 4L and 4R has a bilaterally symmetrical shape, the configuration of the cross member extension 4R will be described as a representative. The cross member extension 4R is formed by pressing a metal plate. As shown in FIGS. 4 and 5, the cross member extension 4 </ b> R includes a cross member joint portion 41, a side member joint portion 45, an inclined surface portion 42, a second inclined surface portion 43, a vertical wall portion 44, and a front side surface 46. And a rear side surface 47 and floor panel joint portions 48 and 49.

  The cross member joint portion 41 is a portion that is overlapped and welded to the outer end portion in the vehicle width direction of the lower surface 31 of the cross member 3. The side member joint portion 45 is a portion that is overlapped and welded to the lower surface 21 of the adjacent side member 2R.

  The inclined surface portion 42 is an inclined surface that smoothly connects the cross member joint portion 41 and the side member joint portion 45. The end of the inclined surface portion 42 on the side member 2R side is located at the inner end in the vehicle width direction on the lower surface 21 of the side member 2R. That is, the inclined surface portion 42 smoothly connects the lower surface 31 of the cross member 3 and the lower surface 21 of the side member 2R.

  The second inclined surface portion 43 is an inclined surface that continues to the cross member joint portion 41 and extends to the inner side surface 22 of the side member 2R. An end of the second inclined surface portion 43 on the side member 2R side is located above the lower surface 21 of the side member 2R. The second inclined surface portion 43 is adjacent to the inclined surface portion 42 in the vehicle front-rear direction, and is located behind the inclined surface portion 42. The inclined surface portion 42 and the second inclined surface portion 43 are inclined in a downward direction as they approach the side member 2R side from the cross member joint portion 41. These inclination angles are different, and the inclination angle of the inclined surface portion 42 is larger than the inclination angle of the second inclined surface portion 43.

  The vertical wall portion 44 is bent downward at the end portion of the second inclined surface portion 43 on the side member 2R side, and extends to the lower surface 21 of the side member 2R. The vertical wall portion 44 is overlapped and welded to the inner side surface 22 of the side member 2R. The vertical wall portion 44 is adjacent to the inclined surface portion 42 in the vehicle front-rear direction, and is located behind the inclined surface portion 42. Further, the vertical wall portion 44 connects the second inclined surface portion 43 and the side member joint portion 45.

  The side member joint portion 45 is bent outward in the vehicle width direction at the end portions of the inclined surface portion 42 and the vertical wall portion 44. The side member joint 45 extends from the inner end in the vehicle width direction on the lower surface 21 of the side member 2R to the center in the vehicle width direction on the lower surface 21.

  The front side surface 46 is a portion bent upward at the front end portions of the cross member joint portion 41 and the inclined surface portion 42. The rear side surface 47 is a portion bent upward at the rear end portions of the cross member joint portion 41 and the second inclined surface portion 43.

Floor panel joint 48 is bent forward at the upper end portion of the front side surface 46, are welded are overlapped on the rear floor panel 11. Floor panel joint 49 is bent backward at the upper end of the rear side 47, are welded are overlapped on the rear floor panel 11.

  As shown in FIG. 6, the ridge line formed at the front end of the lower surface of the cross member extension 4R is along the inclined surface portion 42 described above, and this ridge line is continuous with the ridge line formed at the front end of the lower surface 31 of the cross member 3. ing. The ridge line at the front end of the lower surface 31 of the continuous cross member 3 and the ridge line at the front end of the lower surface of the cross member extension 4R are denoted by reference symbol L1. The ridge line L1 intersects with the ridge line L2 formed at the inner end in the vehicle width direction on the lower surface 21 of the side member 2R. That is, the lower surface front portion of the cross member extension 4R having the inclined surface portion 42 connects the lower surface 31 of the cross member 3 and the lower surface 21 of the side member 2R. Further, the ridge line formed at the rear end of the lower surface of the cross member extension 4 </ b> R is continuous with the ridge line formed at the rear end of the lower surface 31 of the cross member 3. The ridge line at the rear end of the lower surface 31 of the continuous cross member 3 and the ridge line at the rear end of the lower surface of the cross member extension 4R are denoted by reference numeral L3.

  Since the pair of trailing arm support portions 5L and 5R have a bilaterally symmetrical shape, the configuration of the trailing arm support portion 5R will be described as a representative. As shown in FIG. 4, the trailing arm support portion 5R includes an inner bracket 51 welded to the outer surface 23 of the side member 2R and an outer bracket 54 welded to the side sill 9R. The outer bracket 54 includes a facing portion 52 that faces the inner bracket 51 with a space therebetween, and a connecting portion 53 that combines the facing portion 52 and the inner bracket 51. The trailing arm 72 has a front end portion 72a disposed between the inner bracket 51 and the facing portion 52, and is supported by the trailing arm support portion 5 so as to be slidable.

  Since the pair of reinforcing members 6L and 6R have a symmetrical shape, the configuration of the reinforcing member 6R will be described as a representative. The reinforcing member 6R is formed by pressing a metal plate. As shown in FIG. 5, the reinforcing member 6R includes an inner bracket joint surface 61 welded to an inner portion in the vehicle width direction of the inner bracket 51 of the trailing arm support portion 5R, a flange portion 63, an inner reinforcing portion 62, It has a front reinforcing part 64 and a side member joint part 65.

  The inner bracket joint surface 61 is preferably arranged so that at least a part of the longitudinal wall portion 44 of the cross member extension 4R overlaps with the vehicle front-rear direction when viewed from the side of the vehicle. It is arranged so that almost the whole area overlaps.

  The flange portion 63 is a portion that is overlapped and welded to the vertical wall portion 44 of the cross member extension 4R. That is, at the E portion in FIG. 4, the inner side surface 22 of the side member 2R, the vertical wall portion 44 of the cross member extension 4R, and the flange portion 63 of the reinforcing member 6R are sequentially stacked and welded.

  The inner reinforcing portion 62 is a portion extending from the rear end of the inner bracket joint surface 61 to the flange portion 63. The inner reinforcing portion 62 is disposed in the vicinity of the rear end on the lower surface of the cross member extension 4R. As shown in FIG. 6, the inner reinforcing portion 62 is formed with a ridge line L4 that intersects with the ridge line L2 inside the lower surface 21 of the side member 2R. The ridge line L4 of the inner reinforcing portion 62 is located on the extended line of the ridge line L3 at the rear end of the lower surface of the cross member 3 and the cross member extension 4R when viewed from the bottom surface side of the vehicle 10.

  The front reinforcing portion 64 extends forward from the front end of the inner bracket joint surface 61 to the lower surface 21 of the side member 2R. The front end of the front reinforcing portion 64 is positioned on an extension line of the ridge line L1 at the front end of the lower surface of the cross member 3 and the cross member extension 4R. That is, as shown in FIG. 6, a ridge line L5 that intersects the lower surface 21 of the side member 2R is formed in the front reinforcing portion 64, and the front ends of the ridge line L5 are the lower surface front ends of the cross member 3 and the cross member extension 4R. It is located on the extended line of the ridgeline L1. The front reinforcing portion 64 is preferably arranged so that at least a part of the inclined surface portion 42 of the cross member extension 4R overlaps in the vehicle front-rear direction when viewed from the side of the vehicle. Are arranged to overlap.

  The side member joining portion 65 is continuous with the upper end of the inner bracket joining surface 61, the upper end of the inner reinforcing portion 62, and the upper end of the front reinforcing portion 64. The side member joint 65 is overlapped with and welded to the lower surface 21 of the side member 2R and the side member joint 45 of the cross member extension 4R.

  Further, as shown in FIG. 5, a reinforcing member 8 is provided inside the side member 2R so as to connect the ridge line L1 of the cross member extension 4R and the front reinforcing portion 64 of the reinforcing member 6R. Similarly, the reinforcing member 8 is provided inside the side member 2L so as to connect the ridgeline L1 of the cross member extension 4L and the front side reinforcing portion 64 of the reinforcing member 6L.

  According to the vehicle lower structure 1 configured as described above, the vehicle vertical load input to the trailing arm support portions 5L and 5R is received by the inner side surfaces 22 of the side members 2L and 2R via the reinforcing members 6L and 6R. Can do. The strength of the inner side surface 22 is increased by overlapping the vertical wall portions 44 of the cross member extensions 4L and 4R and the flange portions 63 of the reinforcing members 6L and 6R in the vicinity of the trailing arm support portions 5L and 5R. . Therefore, it is possible to suppress the cross-sectional deformation of the side members 2L and 2R due to the vehicle vertical load input to the trailing arm support portions 5L and 5R. Further, the inclined surface portions 42 of the cross member extensions 4L and 4R smoothly connect the lower surface 31 of the cross member 3 and the lower surface 21 of the side members 2L and 2R. As a result, the rigidity of the side members 2L and 2R can be increased, and the cross-sectional deformation of the side members 2L and 2R due to the vehicle left-right load input to the trailing arm support portions 5L and 5R can be suppressed.

  Thus, according to the vehicle lower structure 1, the strength of the side members 2L and 2R can be increased with a small number of parts while increasing the rigidity of the side members 2L and 2R, that is, the rigidity of the vehicle body. Therefore, it is possible to effectively suppress the side members 2L and 2R from being deformed by the load in the vehicle up-down direction or the vehicle left-right direction input to the trailing arm support portions 5L, 5R during traveling.

  Further, as described above, in the vehicle lower structure 1, the reinforcing members 6L and 6R are coupled to the inside of the trailing arm support portions 5L and 5R in the vehicle width direction, and the reinforcing members 6L and 6R are connected to the side members 2L and 2R. A flange portion 63 is provided on the side wall 22 and the vertical wall portions 44 of the cross member extensions 4L and 4R. Thus, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the vertical wall portion 44. That is, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the portion whose strength is increased by the vertical wall portion 44 of the inner side surface 22, and the side members 2L and 2R are deformed. It can be effectively suppressed.

  Further, in the vehicle lower structure 1, as described above, the reinforcing members 6L and 6R have the inner reinforcing portion 62 extending from the inner bracket joint surface 61 to the flange portion 63, and the inner reinforcing portion 62 is the cross member extension 4L. , 4R is disposed near the rear end of the lower surface of 4R. The vertical wall portion 44 described above is provided at the rear end of the lower surface of the cross member extensions 4L and 4R. As a result, the load input to the trailing arm support portions 5L and 5R can be reliably guided to the portion whose strength is increased by the vertical wall portion 44 of the inner side surface 22, and the side members 2L and 2R are deformed. This can be effectively suppressed.

  In the vehicle lower structure 1, as described above, the reinforcing members 6L and 6R have the front reinforcing portion 64 that extends forward from the inner bracket joint surface 61 to the lower surface 21 of the side members 2L and 2R. And the front end of the front side reinforcement part 64 is located on the extension line of the ridgeline L1 formed in the front end in the lower surface of cross member extension 4L, 4R. As a result, the rigidity of the side members 2L and 2R can be increased, and the cross-sectional deformation of the side members 2L and 2R due to the vehicle left-right load input to the trailing arm support portions 5L and 5R can be suppressed. Furthermore, the rigidity of the side members 2L and 2R, that is, the rigidity of the vehicle body can be increased, and the rigidity of the trailing arm support portions 5L and 5R can be increased, so that the operability can be improved.

  In the embodiment described above, the vertical wall portion 44 of the cross member extensions 4L and 4R and the flange portion 63 of the reinforcing members 6L and 6R are provided in the vicinity of the trailing arm support portions 5L and 5R on the inner surface 22 of the side members 2L and 2R. It was piled up. In the present invention, it is more preferable that the three sheet metals of the inner side surface 22, the vertical wall portion 44, and the flange portion 63 are overlapped as described above, but the flange portion 63 is overlapped on the vertical wall portion 44. Is not an essential configuration, and it is sufficient that at least the vertical wall portion 44 overlaps the inner side surface 22. Even in this case, the strength of the inner side surface 22 can be increased, and the cross-sectional deformation of the side members 2L and 2R can be suppressed.

  Further, in the above-described embodiment, the inclined surface portion 42 and the vertical wall portion 44 are adjacent to each other in the vehicle front-rear direction, and the vertical wall portion 44 is located behind the inclined surface portion 42. The wall portion 44 may be positioned in front of the inclined surface portion 42. In that case, the positional relationship between the inner reinforcing portion 62 and the front reinforcing portion 64 may be reversed, and the inner reinforcing portion 62 may be disposed near the front end on the lower surface of the cross member extension 4R.

  The best configuration, method, and the like for carrying out the present invention have been disclosed above, but the present invention is not limited to this. That is, although the present invention has been particularly illustrated and described with respect to particular embodiments, it will be understood that the present invention is not limited in shape to the embodiments described above without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations. Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

DESCRIPTION OF SYMBOLS 1 Vehicle lower structure 2 Side member 3 Cross member 4 Cross member extension 5 Trailing arm support part 21 Lower surface of side member 22 Inner side surface of sad member 31 Lower surface of cross member 42 Inclined surface part 44 Vertical wall part

Claims (4)

A pair of side members extending in the vehicle front-rear direction are arranged on both sides of the vehicle,
A cross member extending in the vehicle width direction is disposed between the pair of side members,
Between the pair of side members and both ends of the cross member, each is connected by a cross member extension,
In the vehicle lower structure in which the lower surface of the cross member is positioned above the lower surfaces of the pair of side members,
The pair of cross member extensions are vertically bent at the end on the side member side adjacent to each other and overlapped with the inner side surface in the vehicle width direction of the side member, the lower surface of the cross member, and the side A vehicle lower structure characterized by having an inclined surface portion that smoothly connects the lower surface of the member. A pair of trailing arm support portions are respectively fixed to the pair of side members,
The pair of trailing arm support portions are disposed on an extension line of both ends of the cross member,
A reinforcing member is coupled to the inside of the trailing arm support portion in the vehicle width direction, and the reinforcing member is fixed to the side member.
The vehicle lower part structure according to claim 1, wherein the reinforcing member has a flange portion overlapped with an inner side surface of the side member and the vertical wall portion of the cross member extension. The reinforcing member has an inner reinforcing portion extending from a joint surface with the trailing arm support portion to the flange portion;
The vehicle lower structure according to claim 2, wherein the inner reinforcing portion is disposed in the vicinity of a front end or a rear end on a lower surface of the cross member extension. The reinforcing member has a front reinforcing portion that extends forward from the joint surface with the trailing arm support portion to the lower surface of the side member;
The vehicle lower part structure according to claim 3, wherein a front end of the front reinforcing portion is located on an extension line of a ridge line formed at a front end of the lower surface of the cross member extension.

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