Side sill

Abstract

To control the transfer route of a side-face collision load and the absorption of a side-face collision energy while suppressing the deformation of a vehicular body when a side-face collision occurs.SOLUTION: A side sill 2 of an automobile includes: a first engagement portion 33a formed at a first vertical wall 33 of a sill-inner first reinforcement member 30; and a second engagement portion 43a formed at a second vertical wall 43 of a sill-inner second reinforcement member 40. The first engagement portion 33a displaces in accordance with the deformation of a side sill outer member 10 due to a side-face collision load F, and is engaged with the second engagement portion 43a.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to automotive side sills. [Background technology]

[0002] In automobiles, side sills are located between the front and rear tires at the bottom of both sides of the vehicle body. When a collision load is applied to the side of the body, the side sills bend and dissipate the energy of the collision to the opposite side sill via the body cross member, which is a reinforcing member of the vehicle's floor structure.

[0003] Patent Document 1 discloses a side sill having a profiled part within the cross section of the side sill for absorbing collision energy. The side sill includes an outer sill member and an inner sill member. The outer sill member bulges outward from the vehicle and has a first profiled part therein. The inner sill member extends in the vertical direction and has an outer profiled part on the vehicle interior side. The outer profiled part bulges outward from the vehicle and has a second profiled part therein. The cross sections of the first profiled part and the inner sill member have convex shapes that protrude toward the vehicle interior side. The convex part of the cross section of the inner sill member is accommodated in the convex part of the cross section of the first profiled part. The cross section of the second profiled part has a convex shape formed so as to protrude toward the vehicle exterior side. The tip of the convex part of the cross section of the second profiled part is arranged to face the tip of the convex part of the cross section of the first profiled part and the inner sill member.

[0004] According to Patent Document 1, the side sill absorbs the energy of a side collision by crushing the profile parts attached to the outer sill member and inner sill member, thereby protecting occupants in the vehicle cabin or the battery pack installed under the floor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2022-531463 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is also a demand for protecting passengers in the vehicle cabin and the drive battery located between the side sills while suppressing deformation of the vehicle body during a side collision. In this regard, according to Patent Document 1, the side sills are actively crushed to absorb the collision energy, so it is unclear whether this is effective enough in suppressing deformation of the vehicle body during a side collision.

[0007] Furthermore, because the side sill has a closed cross section, the internal plates cannot be fixed together. Therefore, when the side sill collapses during a side collision, the inner sill member and the second profile part may shift vertically relative to each other, preventing the load from being transmitted from the outer sill member to the outer profile part, which may result in the load not being absorbed as intended.

[0008] The present disclosure has been made in consideration of the above points, and an object thereof is to control the transmission path of a load received during a side collision. [Means for solving the problem]

[0009] To achieve the above object, one aspect of the present disclosure can be based on a side sill for an automobile, which includes a side sill outer member disposed on the outer side in a vehicle width direction and having an outer upper joint, an outer lower joint, and an outer bulging portion bulging outward in the vehicle width direction from a portion between the outer upper and lower joints, a side sill inner member disposed on the inner side in the vehicle width direction and having an inner upper joint, an inner lower joint, and an inner bulging portion bulging inward in the vehicle width direction from a portion between the inner upper and lower joints, a first in-sill reinforcing member fixed to the inner side of the side sill outer member in the vehicle width direction, and a second in-sill reinforcing member fixed to the outer side of the side sill inner member in the vehicle width direction. The side sill has a closed cross-sectional structure formed by joining an outer upper joint of the side sill outer member to which the first in-sill reinforcing member is fixed and an inner upper joint of the side sill inner member to which the second in-sill reinforcing member is fixed, and by fixing an outer lower joint of the side sill outer member to an inner lower joint of the side sill inner member. At least one of the first in-sill reinforcing member or the second in-sill reinforcing member is formed with an engaging portion that engages with the other, and the cross section of the engaging portion has a protruding shape that protrudes toward the other, and the engaging portion engages with the other as the side sill outer member deforms due to a side collision load.

[0010] With this configuration, as the side sill outer member deforms due to a side collision load, the engaging portion formed on at least one of the first reinforcing member within the sill or the second reinforcing member within the sill engages with the other, thereby ensuring that the side collision load is transmitted from the first reinforcing member within the sill to the second reinforcing member within the sill.

[0011] The engaging portion formed on at least one of the reinforcing members may at least partially overlap the other reinforcing member when viewed in the vehicle width direction.

[0012] With this configuration, the transmission path of the side collision load is not interrupted, so that the side collision load can be reliably transmitted from the first in-sill reinforcing member to the second in-sill reinforcing member.

[0013] The first reinforcing member within the sill may have a pair of first upper and first lower joints spaced apart in the vehicle up-down direction and extending along the vehicle front-rear direction, a first vertical wall portion extending along the vehicle up-down direction and extending along the vehicle front-rear direction, and first upper and first lower wall portions provided between the first upper and first lower joints and the first vertical wall portion, while the second reinforcing member within the sill may have a pair of second upper and second lower joints spaced apart in the vehicle up-down direction and extending along the vehicle front-rear direction, a second vertical wall portion extending along the vehicle up-down direction and extending along the vehicle front-rear direction, and second upper and second lower wall portions provided between the second upper and second lower joints and the second vertical wall portion. The engaging portion may be formed on at least one of the first vertical wall portion or the second vertical wall portion, and the second upper wall portion may be disposed between the first upper wall portion and the first lower wall portion in the vehicle up-down direction.

[0014] With this configuration, the side collision load transmitted through the first upper wall portion and the first lower wall portion is transmitted to the second upper wall portion via the first vertical wall portion, thereby ensuring that the side collision load is transmitted from the first reinforcing member within the sill to the second reinforcing member within the sill.

[0015] The engaging portion may include a first engaging portion formed on a first vertical wall portion of the first sill-internal reinforcing member and a second engaging portion formed on a second vertical wall portion of the second sill-internal reinforcing member.

[0016] According to this configuration, the first engagement portion formed on the first vertical wall portion and the second engagement portion formed on the second vertical wall portion engage with each other, so that the side collision load can be reliably transmitted from the first reinforcing member within the sill to the second reinforcing member within the sill.

[0017] The first engaging portion and the second engaging portion may at least partially overlap each other when viewed from the top-bottom direction.

[0018] With this configuration, when the side sill is subjected to a side collision load, even if the first vertical wall portion undergoes deformation and moves up and down relative to the second vertical wall portion, at least a portion of the first engagement portion can engage with the second engagement portion, so the side collision load can be reliably transmitted from the first reinforcing member within the sill to the second reinforcing member within the sill. [Effects of the Invention]

[0019] As described above, as the side sill outer member deforms due to a side collision load, the engaging portion formed on at least one of the first reinforcing member within the sill or the second reinforcing member within the sill engages with the other, thereby ensuring that the side collision load can be transmitted reliably from the first reinforcing member within the sill to the second reinforcing member within the sill. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view showing an automobile lower body structure according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the side sill. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a view equivalent to FIG. 3, showing the side sill disassembled into its constituent parts. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a diagram equivalent to FIG. 5, illustrating how the energy of a collision is absorbed. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0022] FIG. 1 shows an automobile lower body structure U equipped with a side sill according to an embodiment of the present invention. The lower body structure U includes a floor 1. The floor 1 includes left and right side sills 2, 2, a floor panel 3, and body cross members 4, 5. The floor panel 3 extends in the longitudinal direction and the vehicle width direction. The left side sill 2 extends in the longitudinal direction along the left edge of the floor panel 3. The right side sill 2 extends in the longitudinal direction along the right edge of the floor panel 3.

[0023] A plurality of body cross members 4, 5 extending in the vehicle width direction are provided at intervals in the front-rear direction on the upper surface of the floor panel 3. The body cross members 4, 5 are members with a cross section that opens downward, and are joined to the upper surface of the floor panel 3 to form a closed cross section structure.

[0024] The left end portions of the body cross members 4, 5 are fixed to the interior surface of the left side sill 2 in the vehicle width direction, and the right end portions of the body cross members 4, 5 are fixed to the interior surface of the right side sill 2 in the vehicle width direction. This results in the left and right side sills 2, 2 being connected by the body cross members 4, 5. The upper surfaces of the body cross members 4, 5 are connected by seat rails extending in the fore-and-aft direction, and a seat is attached to the top of the seat rails.

[0025] As shown in Figure 5, in the case of an electric vehicle or hybrid vehicle, a drive battery unit that supplies power to the driving motor is disposed below the floor panel 3. The drive battery unit includes a plurality of battery cells 6 arranged in the front-rear and width directions of the vehicle, and a battery case 7 that houses the battery cells 6. The battery case 7 is fixed to the floor panel 3 or the side sill 2.

[0026] In the description of this embodiment, the front side of the vehicle will be simply referred to as the "front," the rear side of the vehicle will be simply referred to as the "rear," the right side when facing the front of the vehicle will be referred to as the "right side," and the left side will be referred to as the "left side." Furthermore, the outside in the vehicle width direction will be referred to as the "outside side," and the inside in the vehicle width direction will be referred to as the "inside side."

[0027] (Side sill structure) As shown in Figure 2, the side sill 2 includes a side sill outer member 10 that is arranged on the exterior side of the vehicle and has a cross-sectional shape that opens toward the interior side of the vehicle, a side sill inner member 20 that is arranged on the interior side of the vehicle and has a cross-sectional shape that opens toward the exterior side of the vehicle, a first in-sill reinforcing member 30 and a second in-sill reinforcing member 40 that have cross-sectional shapes that open toward the exterior side of the vehicle.

[0028] 3 and 4, the side sill outer member 10 includes a pair of outer upper joints 11 and outer lower joints 12 that are spaced apart in the vehicle up-down direction and extend along the vehicle front-rear direction, and an outer bulging portion 13 that bulges outward from the portion between the outer upper joint 11 and the outer lower joint 12. An outer vertical wall portion 14 is formed at the tip of the outer bulging portion 13. The outer bulging portion 13 includes the outer vertical wall portion 14, an outer upper wall portion 15, and an outer lower wall portion 16.

[0029] The outer upper joint 11 extends in the up-down direction and in the front-rear direction. From the lower end of the outer upper joint 11, an outer upper wall 15 extends toward the exterior of the vehicle, extending in the front-rear direction. From the exterior end of the outer upper wall 15, an outer vertical wall 14 extends downward, extending in the front-rear direction. From the lower end of the outer vertical wall 14, an outer lower wall 16 extends toward the interior of the vehicle, extending in the front-rear direction. From the interior end of the outer lower wall 16, an outer lower joint 12 extends downward, extending in the front-rear direction.

[0030] The side sill inner member 20 includes a pair of inner upper joints 21 and inner lower joints 22 that are spaced apart in the vehicle up-down direction and extend along the vehicle front-rear direction, and an inner bulge 23 that bulges toward the vehicle interior from the portion between the inner upper joint 21 and the inner lower joint 22. An inner vertical wall 24 is formed at the tip of the inner bulge 23. The inner bulge 23 includes the inner vertical wall 24, an inner upper wall 25, and an inner lower wall 26.

[0031] The inner upper joint 21 extends in the up-down direction and in the front-rear direction. From the lower end of the inner upper joint 21, an inner upper wall portion 25 extends toward the vehicle interior and also extends in the front-rear direction. The inner upper wall portion 25 has an inner upper bent portion 25a in its middle portion in the vehicle width direction, an inner upper outer-car wall portion 25b extending in the vehicle width direction from the lower end of the inner upper joint 21 to the inner upper bent portion 25a, and an inner upper inner-car wall portion 25c positioned lower as it moves toward the vehicle interior from the inner upper bent portion 25a. From the vehicle interior end of the inner upper wall portion 25, an inner vertical wall portion 24 extends downward and also extends in the front-rear direction. From the lower end of the inner vertical wall portion 24, an inner lower wall portion 26 extends toward the vehicle exterior and also extends in the front-rear direction. The inner lower joint portion 22 extends downward from the outer end of the inner lower wall portion 26 along the front-rear direction.

[0032] An inner upper plate 250 is fixed to the inner surface of the inner bulge portion 23 of the inner upper wall portion 25 of the side sill inner member 20. The inner upper plate 250 has a bent portion 250a of the inner upper plate 250, and an exterior joint portion 250b and an interior joint portion 250c of the inner upper plate 250 that are bent at the bent portion 250a of the inner upper plate 250 to form a shape along the inner upper wall portion 25. The exterior joint portion 250b of the inner upper plate 250 extends from the lower end of the inner upper joint portion 21 to the inner upper bent portion 25a. The interior joint portion 250c of the inner upper plate 250 extends from the inner upper bent portion 25a to the upper end of the inner vertical wall portion 24. The outer joint 250b of the inner upper plate 250 is fixed to the inner upper outer wall 25b, and the inner joint 250c is fixed to the inner upper inner wall 25c. The bent portion 250a of the inner upper plate 250 overlaps the inside of the inner upper bent portion 25a of the inner bulge 23.

[0033] An inner lower plate 260 is fixed to the inner surface of the inner bulge portion 23 of the inner lower wall portion 26 of the side sill inner member 20. The inner lower plate 260 has a connecting portion 260a of the inner lower plate 260, an upper joint portion 260b of the inner lower plate 260, and a lower joint portion 260c of the inner lower plate 260. The connecting portion 260a of the inner lower plate 260 connects a middle portion of the lower half of the inner vertical wall portion 24 to a middle portion of the inner lower wall portion 26 in the vehicle width direction. The upper joint portion 260b of the inner lower plate 260 extends from a middle portion below the middle of the inner vertical wall portion 24 to the middle of the inner vertical wall portion 24. The lower joint portion 260c of the inner lower plate 260 extends from the middle portion of the inner lower wall portion 26 in the vehicle width direction to the upper end portion of the inner lower joint portion 22. The upper joint portion 260b of the inner lower plate 260 is fixed to the inner vertical wall portion 24, and the lower joint portion 260c of the inner lower plate 260 is fixed to the inner lower wall portion 26.

[0034] The first sill interior reinforcing member 30 includes a pair of first upper and lower joints 31 and 32 extending along the vehicle longitudinal direction and spaced apart in the vehicle vertical direction, a first vertical wall portion 33 extending along the vehicle longitudinal direction, and a pair of first upper and lower wall portions 34 and 35 extending along the vehicle longitudinal direction and spaced apart in the vehicle vertical direction, and disposed between the first upper and lower joints 31 and 32 and the first vertical wall portion 33. The first vertical wall portion 33 is formed with a first engaging portion 33a having a convex cross section that protrudes toward the interior of the vehicle. The first engaging portion 33a has a first engaging surface 33b that engages with the second sill interior reinforcing member 40 (described later). The first upper wall portion 34 is formed so as to be positioned higher from the upper end of the first vertical wall portion 33 toward the exterior of the vehicle. The first upper joint 31 extends upward from the exterior end of the first upper wall portion 34. The first lower wall portion 35 is formed so as to be positioned lower as it moves toward the vehicle exterior from the lower end portion of the first vertical wall portion 33. The first lower joint portion 32 extends downward from the end portion of the first lower wall portion 35 on the vehicle exterior side.

[0035] The first sill interior reinforcement member 30 includes a first backing plate 300. The first backing plate 300 includes a pair of first upper joints 310 and first lower joints 320 of the first backing plate 300 that extend along the vehicle longitudinal direction and are spaced apart in the vehicle vertical direction, a first vertical wall portion 330 of the first backing plate 300 that extends along the vehicle vertical direction and also along the vehicle longitudinal direction, and a pair of first upper wall portions 340 and first lower wall portions 350 of the first backing plate 300 that extend along the vehicle longitudinal direction and are spaced apart in the vehicle vertical direction and are provided between the first upper joints 310 and first lower joints 320 of the first backing plate 300 and the first vertical wall portion 330 of the first backing plate 300. The first backing plate 300 may be formed with a first engagement portion that has a convex shape that protrudes toward the interior of the vehicle. The first backing plate 300 has a shape that follows the outer surface of the first in-sill reinforcing member 30, and is formed integrally with the first in-sill reinforcing member 30. In the following description, when indicating the portion to which the backing plate is fixed, if the reference numeral for the backing plate and the reference numeral for the reinforcing member are the same, the reference numeral for the reinforcing member will be used.

[0036] The first in-sill reinforcing member 30 is housed in the side sill outer member 10. The first upper joint 31 is fixed to the vehicle interior surface 14a of the side sill outer member 10 above the middle of the outer vertical wall portion 14. The first lower joint 32 is fixed to the vehicle interior surface 14a of the side sill outer member 10 below the middle of the outer vertical wall portion 14.

[0037] The first reinforcing member 30 within the sill may have a strength difference between the first vertical wall portion 33 and the first engaging portion 33a, and the strength of the first vertical wall portion 33 may be greater than the strength of the first engaging portion 33a. The strength difference can be achieved by changing the plate thickness or material. When the strength difference is achieved by changing the plate thickness, a stacked structure or a tailored blank may be used. When the strength difference is achieved by changing the material, high-tensile steel, ultra-high-tensile steel, or hot-stamped steel may be used, or heat treatment may be performed. Furthermore, these may be used in combination.

[0038] The second sill inner reinforcement member 40 includes a pair of second upper joints 41 and second lower joints 420 that extend along the vehicle longitudinal direction and are spaced apart in the vehicle vertical direction, a second vertical wall portion 43 that extends along the vehicle vertical direction and also along the vehicle longitudinal direction, and a pair of second upper wall portions 44 and second lower wall portions 450 that extend along the vehicle longitudinal direction and are spaced apart in the vehicle vertical direction and are provided between the second upper joints 41 and second lower joints 420 and the second vertical wall portion 43. The second lower joints 420 are located between the outer lower joint 12 of the side sill outer member 10 and the inner lower joint 22 of the side sill inner member 20. The second vertical wall portion 43 faces the first vertical wall portion 33. The second vertical wall portion 43 is formed with a second engagement portion 43a that has a convex cross section that protrudes toward the vehicle exterior. The second engagement portion 43a has a second engagement surface 43b that engages with the first in-sill reinforcing member 30. The second lower wall portion 450 is provided between the lower end of the second vertical wall portion 43 and the upper end of the second lower joint portion 420. The second lower wall portion 450 is located approximately as far outboard as the second engagement portion 43a from the second vertical wall portion 43.

[0039] The second in-sill reinforcement member 40 includes a second backing plate 400. The second backing plate 400 includes a second lower joint portion 420 of the second backing plate 400 extending in the vehicle longitudinal direction, a second vertical wall portion 430 of the second backing plate 400 extending in the vehicle up-down direction and also extending in the vehicle longitudinal direction, a second upper wall portion 440 of the second backing plate 400 disposed along the vehicle width direction from the upper end of the second vertical wall portion 430 of the second backing plate 400 and extending in the vehicle longitudinal direction, and a second lower wall portion 450 of the second backing plate 400 extending in the vehicle longitudinal direction and provided between the second lower joint portion 420 of the second backing plate 400 and the second vertical wall portion 430 of the second backing plate 400. A second engagement portion 430a of the second backing plate 400 having a convex shape that protrudes toward the vehicle exterior is formed on the second vertical wall portion 430 of the second backing plate 400. The second engagement portion 430a of the second backing plate 400 has a second engagement surface 430b of the second backing plate 400. The second backing plate 400 has a shape that follows the interior surface of the second in-sill reinforcing member 40, and is formed integrally with the second in-sill reinforcing member 40.

[0040] The second in-sill reinforcing member 40 is housed within the side sill inner member 20. The second upper joint 41 is fixed to the surface 24a of the side sill inner member 20 on the vehicle exterior side, above the middle of the inner vertical wall portion 24, and on the inside of the inner bulge portion 23. The second lower joint 420 is fixed to the surface 22a of the inner lower joint 22 on the vehicle exterior side of the side sill inner member 20.

[0041] The second reinforcing member 40 within the sill may have a strength difference between the second vertical wall portion 43 and the second upper wall portion 44 and the second upper joint portion 41, the second lower wall portion 450 of the second backing plate 400, and the second lower joint portion 420. The strength of the second vertical wall portion 43 and the second upper wall portion 44 may be greater than the strength of the second upper joint portion 41, the second lower wall portion 450 of the second backing plate 400, and the second lower joint portion 420. The strength difference can be achieved by changing the plate thickness or material. When the strength difference is achieved by changing the plate thickness, a stacked structure or a tailored blank may be used. When the strength difference is achieved by changing the material, high-tensile steel, ultra-high-tensile steel, or hot-stamped steel may be used, and heat treatment may be performed. Furthermore, these may be used in combination.

[0042] The strength of the first upper wall portion 34 and the first lower wall portion 35 of the first reinforcing member 30 within the sill may be greater than the strength of the second upper wall portion 44 of the second reinforcing member 40 within the sill, and the strength of the second upper wall portion 44 of the second reinforcing member 40 within the sill may be greater than the strength of the outer upper wall portion 15 and the outer lower wall portion 16 of the side sill outer member 10.

[0043] The side sill 2 has a closed cross-sectional structure formed by joining the outer upper joint 11 of the side sill outer member 10, to which the first in-sill reinforcing member 30 is fixed, and the inner upper joint 21 of the side sill inner member 20, to which the second in-sill reinforcing member 40 is fixed, and by joining the outer lower joint 12 of the side sill outer member 10 and the inner lower joint 22 of the side sill inner member 20. At least one of the first engagement portion 33a and the second engagement portion 43a is positioned so that at least a portion of the first engagement portion 33a overlaps with the other vertical wall portion 33, 43 when viewed from the vehicle width direction. The first engagement surface 33b of the first engagement portion 33a and the second engagement surface 43b of the second engagement portion 43a at least partially overlap with each other when viewed from the vertical direction. The second upper wall portion 44 is positioned between the first upper wall portion 34 and the first lower wall portion 35 in the vehicle vertical direction.

[0044] (Side sill manufacturing method) The side sill 2 is manufactured as follows.

[0045] The side sill outer member 10, the first in-sill reinforcing member 30, the first backing plate 300, the side sill inner member 20, the inner upper plate 250, the inner lower plate 260, the second in-sill reinforcing member 40, and the second backing plate 400 are each obtained by press molding. The material and plate thickness are selected appropriately.

[0046] The first reinforcing member 30 within the sill and the first backing plate 300 are overlapped, and the first upper joint 31 and the first upper joint 310 of the first backing plate 300, the first lower joint 32 and the first lower joint 320 of the first backing plate 300, the first vertical wall portion 33 and the first vertical wall portion 330 of the first backing plate 300, the first upper wall portion 34 and the first upper wall portion 340 of the first backing plate 300, and the first lower wall portion 35 and the first lower wall portion 350 of the first backing plate 300 are each joined by resistance spot welding. The first reinforcing member 30 within the sill is accommodated inside the outer bulge 13 of the side sill outer member 10, and the first upper joint 31 is joined above the middle of the interior surface 14a of the outer vertical wall portion 14, and the first lower joint 32 is joined below the middle of the interior surface 14a of the outer vertical wall portion 14, by resistance spot welding.

[0047] The second in-sill reinforcing member 40 and the second backing plate 400 are overlapped, and the second vertical wall portion 43 and the second vertical wall portion 430 of the second backing plate 400, as well as the second upper wall portion 44 and the second upper wall portion 440 of the second backing plate 400, are each joined by resistance spot welding. The second in-sill reinforcing member 40 is housed inside the inner bulge portion 23 of the side sill inner member 20, and the second upper joint portion 41 is joined above the middle of the inside surface 24a of the inner vertical wall portion 24, and the second lower joint portion 42 is joined to the vehicle exterior surface 22a of the inner lower joint portion 22, each by resistance spot welding.

[0048] The outer upper joint 11 of the side sill outer member 10 and the inner upper joint 21 of the side sill inner member 20, as well as the outer lower joint 12 of the side sill outer member 10 and the inner lower joint 22 of the side sill inner member 20, are joined by resistance spot welding.

[0049] Here, the first vertical wall portion 33 including the first engaging portion 33a and the second vertical wall portion 43 including the second engaging portion 43a are not joined and are spaced apart in the vehicle width direction, thereby preventing the rigidity of the vehicle body from becoming too high. This reduces unpleasant vibrations or high-frequency noise transmitted from the road surface and engine to the occupants through the vehicle body, and allows the vehicle body to deform appropriately during driving operations, thereby providing the driver with an appropriate operating feel.

[0050] The joining method is not limited to resistance spot welding, and laser spot welding, arc welding, or adhesive may also be used, or these may be used in combination.

[0051] (Transmission path of side collision load) The transmission path of a side collision load F is shown in Figure 5. When a side impact object P collides with the exterior side of the right side sill 2, the side collision load F deflects the side sill outer member 10 toward the interior of the vehicle, and is transmitted from the side sill outer member 10 through the first upper wall portion 34 and the first lower wall portion 35 of the first in-sill reinforcing member 30 to the first vertical wall portion 33. The side collision load F is transmitted from the first vertical wall portion 33 to the second vertical wall portion 43 of the second in-sill reinforcing member 40 when the first engagement surface 33b of the first engagement portion 33a engages with the second engagement surface 43b of the second engagement portion 43a. The side collision load F transmitted to the second vertical wall portion 43 of the second in-sill reinforcing member 40 is then transmitted from the second upper wall portion 44 to the side sill inner member 20. Finally, the force is transmitted from the side sill inner member 20 to the body cross member 4 and floor panel 3, and acts on the left side sill 2 (not shown).

[0052] As explained above, the side collision load F is transmitted to the left side sill 2 via the body cross members 4 and 5, deflecting the right side sill 2 toward the interior of the vehicle. The side collision object P may be a vehicle, a pole specified in various side collision tests, or an aluminum honeycomb.

[0053] When a load F' greater than the side collision load F is applied, the first in-sill reinforcing member 30 and the second in-sill reinforcing member 40 engage with each other, causing the side sill 2 to collapse while absorbing the collision energy. The manner in which the side sill 2 collapses will be described with reference to FIGS. 6A to 6D. As shown in FIG. 6A, when a side collision load F is input to the side sill 2, the side sill outer member 10 deforms. When viewed from the vehicle width direction, at least a portion of at least one of the first engagement portion 33a and the second engagement portion 43a overlaps with the other vertical wall portion 33, 43. Therefore, the first engagement portion 33a formed on the first vertical wall portion 33 of the first in-sill reinforcing member 30 engages with the second engagement surface 43b of the second engagement portion 43a formed on the second vertical wall portion 43 of the second in-sill reinforcing member 40. The side collision load is transmitted to the sill inner second reinforcing member 40 via the sill inner first reinforcing member 30, causing the outer upper wall portion 15 and the outer lower wall portion 16 of the side sill outer member 10 to buckle. When the outer upper wall portion 15 and the outer lower wall portion 16 of the side sill outer member 10 buckle, the collision energy is absorbed.

[0054] Once the walls 15, 16 of the side sill outer member 10 have finished absorbing the collision energy, the second upper wall portion 44 of the second in-sill reinforcing member 40 buckles and transmits the side collision load F, as shown in Fig. 6B. Next, as shown in Fig. 6C, the battery case holding member 70 also helps to absorb the collision energy, and finally, as shown in Fig. 6D, the first upper wall portions 34, 35 of the first in-sill reinforcing member 30 absorb the collision energy, protecting the drive battery unit from the side collision load F.

[0055] (Effects of the embodiment) As described above, with the side sill 2 according to this embodiment, the side collision load F deflects the side sill outer member 10 toward the vehicle interior, and is transmitted from the side sill outer member 10 to the first vertical wall portion 33 of the first intra-sill reinforcing member 30 through the first upper wall portion 34 and the first lower wall portion 35. When the side collision load F is transmitted from the first intra-sill reinforcing member 30 to the second intra-sill reinforcing member 40, the first engagement surface 33b of the first engagement portion 33a provided on the first vertical wall portion 33 and the second engagement surface 43b of the second engagement portion 43a provided on the second vertical wall portion 43 engage with each other. This ensures that the side collision load F is transmitted from the first intra-sill reinforcing member 30 to the second intra-sill reinforcing member 40. [Industrial Applicability]

[0056] As described above, the side sill according to the present invention can be used to control the transmission path of a side collision load received during a side collision. [Explanation of symbols]

[0057] 2 Side sill 10 Side sill outer member 11 Outer upper joint 12 Outer lower joint 13 Outer bulge 20 Side sill inner member 21 Inner upper joint 22 Inner lower joint 23 Inner bulge 30 First reinforcing member inside sill 31 1st upper joint 32 1st lower joint 33 First vertical wall section 33a First engaging part 34 1st upper wall section 35 1st lower wall section 40 Second reinforcing member inside sill 41 2nd upper joint 420 2nd lower joint 43 Second vertical wall section 43a second engagement portion 44 Second upper wall section 450 2nd lower wall section

Claims

1. A side sill of a motor vehicle, a side sill outer member disposed on the outer side in the vehicle width direction and having an outer upper joint portion, an outer lower joint portion, and an outer bulging portion bulging outward in the vehicle width direction from a portion between the outer upper and lower joint portions; a side sill inner member disposed on the inner side in the vehicle width direction and having an inner upper joint portion, an inner lower joint portion, and an inner bulge portion bulging inward in the vehicle width direction from a portion between the inner upper and lower joint portions; a first reinforcing member in the side sill fixed to an inner side of the side sill outer member in the vehicle width direction within the side sill; and a second reinforcing member in the side sill fixed to an outer side of the side sill inner member in the vehicle width direction within the side sill, the side sill has a closed cross-sectional structure in which the outer upper joint of the side sill outer member to which the first sill internal reinforcing member is fixed and the inner upper joint of the side sill inner member to which the second sill internal reinforcing member is fixed are joined together, and the outer lower joint of the side sill outer member and the inner lower joint of the side sill inner member are fixed together; At least one of the first reinforcing member within the sill and the second reinforcing member within the sill is formed with an engaging portion that engages with the other, a cross section of the engaging portion having a convex shape that protrudes toward the other; The engaging portion engages with the other portion in response to deformation of the side sill outer member due to a side collision load.

2. 2. The side sill of the automobile according to claim 1, A side sill for an automobile, wherein an engaging portion formed on at least one of the reinforcing members at least partially overlaps the other reinforcing member when viewed in the vehicle width direction.

3. 2. The side sill of the automobile according to claim 1, The first reinforcing member within the sill has a pair of first upper joints and first lower joints that are spaced apart in the vehicle up-down direction and extend along the vehicle front-rear direction, a first vertical wall portion that extends along the vehicle up-down direction and also along the vehicle front-rear direction, and a first upper wall portion and a first lower wall portion that are provided between the first upper joints and the first vertical wall portion, and between the first upper joints and the first lower joints and the first vertical wall portion, the second reinforcing member within the sill includes a pair of second upper joints and second lower joints spaced apart in the vehicle up-down direction and extending along the vehicle longitudinal direction, a second vertical wall portion extending along the vehicle up-down direction and also along the vehicle longitudinal direction, and a second upper wall portion and a second lower wall portion provided between the second upper joints and the second vertical wall portion, and the engaging portion is formed on at least one of the first vertical wall portion and the second vertical wall portion, A side sill of an automobile, wherein the second upper wall portion is disposed between the first upper wall portion and the first lower wall portion in the vehicle vertical direction.

4. 2. The side sill of the automobile according to claim 1, A side sill of an automobile, wherein the engagement portion includes a first engagement portion formed on the first vertical wall portion of the first reinforcing member within the sill and a second engagement portion formed on the second vertical wall portion of the second reinforcing member within the sill.

5. 5. The side sill of an automobile according to claim 4, A side sill for an automobile, wherein the first engagement portion and the second engagement portion at least partially overlap each other when viewed from above and below.

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