JP2020082858A - Side member unit - Google Patents

Abstract

To provide a side member unit that can include rigidity and rest prevention associated with a connected portion between a first side member and a second side member that are a part of components of the side member unit.SOLUTION: A side member unit (15) includes: a first side member (31) extending in the vehicle front-to-back direction below a vehicle body (3) of a vehicle (1); and a second side member (33) formed connected to a rear portion of the first side member and extending in the vehicle front-to-back direction below the vehicle body. The side member unit includes a connected portion (32) in which the second side member is connected to the inner side of the first side member in an overlapped manner. The second side member is formed with a recessed portion (73) recessed on a side surface (53) of the second side member toward the inner side in the right-to-left direction of the second side member. The recessed portion is formed extending from a front end of the second side member to a location rearward of the connected portion in the vehicle front-to-back direction.SELECTED DRAWING: Figure 3

Description

The present invention relates to a side member unit, and more particularly to a technique for improving the bondability between a front side member and a floor side member.

A pair of left and right side member units extending in the front-rear direction of the vehicle are disposed at the bottom of the body of a typical vehicle.
The side member unit includes a plurality of parts such as a front side member, a floor side member, and a rear side member, and is integrally formed by welding the plurality of parts (Patent Document 1).

JP-A-9-24863

However, since the joint portion that joins the front side member and the floor side member as in the above-mentioned patent document is joined by welding, there is a possibility that the joint portion may be damaged by an impact such as a collision of a vehicle, and there is room for further improvement. It was
By the way, it is conceivable to increase the strength of the joining portion by bringing the mating surfaces of the side members into contact with each other without a gap and joining them against the damage due to the impact such as the collision of the vehicle.

However, if the mating surfaces of the side members are brought into contact with each other without a gap and joined together, the paint may not reach the details inside the side members during electrodeposition coating in the production process.
The present invention has been made in view of the above problems, and an object thereof is rigidity related to a connecting portion between a first side member and a second side member, which is a part of constituent parts of a side member unit. Another object of the present invention is to provide a side member unit that can have rust prevention.

To achieve the above object, a side member unit of the present invention includes a first side member that is formed on a lower side of a vehicle body of a vehicle and extends in the vehicle front-rear direction, and a lower side of the vehicle body that is coupled to a rear portion of the first side member. In a side member unit including a second side member formed to extend in the vehicle front-rear direction on the side, in the side member unit, the second side member is coupled to the inside of the first side member in an overlapping manner. The second side member has a coupling portion, and a concave portion is formed on a side surface of the second side member so as to be concave inward in the left-right direction of the second side member, and the concave portion is the second portion in the vehicle front-rear direction. It is characterized in that it is formed so as to extend from the front end of the side member to the rear of the connecting portion.

Thus, the second side member of the side member unit is formed with a recessed portion that is recessed inward in the left-right direction of the second side member, and the recessed portion extends in the vehicle front-rear direction from the front end of the second side member to the rear of the coupling portion. By being formed as described above, the rigidity of the coupling portion in the side member unit can be increased.
Further, since the communication passage is formed between the first side member and the second side member, the paint for electrodeposition coating in the production process can reach the details inside the side member unit, and the rust prevention can be improved. To be done.

As another aspect, the recess is formed so as to extend to a lower end of the second side member in the vehicle vertical direction on a side surface of the second side member and extend to a lower end of the second side member, and the first side member and the second side member may be formed. It is preferable that at least the side surface is coupled to the upper side in the vehicle vertical direction.
Thus, for example, even when water enters the inside of the side member unit due to the vehicle traveling in a puddle, the side member unit is formed by the communication passage of the recess formed to the lower end of the lower side of the second side member. It is also possible to improve the drainage of the water inside.

As another aspect, a parallel portion that extends in the vehicle front-rear direction from the front end of the second side member to the joint portion in parallel with the vehicle front-rear direction, and inclines outward in the vehicle left-right direction from the joint portion toward the vehicle front-rear direction rear side. It is preferable to have an inclined part.
Accordingly, even if a shock is applied to the connecting portion in the vehicle front-rear direction due to a frontal collision of the vehicle, for example, the inclined portion inclines outward in the vehicle left-right direction, so that the front-rear impact of the side member unit is reduced to the second direction. Since it can be received by the side member, it is possible to suppress stress concentration from occurring in the recess.

As another aspect, it is preferable that the first side member is provided with a bead formed in a lower surface of the coupling portion so as to be recessed downward in the vehicle vertical direction and extend in the vehicle longitudinal direction.
Thus, the bead is formed at the lower end of the first side member at the position corresponding to the connecting portion, so that the lower end of the first side member at the position corresponding to the connecting portion is reinforced without interfering with the second side member. Is possible.

As another aspect, it is preferable that the bead is formed to extend forward of the vehicle in the vehicle front-rear direction from the coupling portion.
As a result, a bead is formed across the connecting portion of the first side member, that is, the front end portion of the second side member inside the first side member, so that the portion of the first side member to which the impact is applied is reinforced. Is possible.

Further, even when water enters the inside of the side member unit, the drainage of water inside the side member unit is improved by the communication passage of the recess formed to the lower front end of the second side member. Is also possible.
As another aspect, it is preferable that the plurality of beads are formed side by side in the vehicle left-right direction, and the first side member and the second side member are coupled at least at a position sandwiched by the plurality of beads. ..

As a result, by fixing the first side member and the second side member at a position sandwiched by a plurality of beads, the rigidity of the lower end of the first side member in the direction in which the vehicle front-rear direction is twisted about the axis is increased. Thus, it is possible to suppress a force such that the lower end of the first side member and the lower end of the second side member are separated from each other from being applied to the fixed point.
As another aspect, inside the second side member, a plate shape extending along the concave portion and the lower surface of the second side member from the rear of the concave portion of the second side member to the coupling portion in the vehicle front-rear direction. It is preferred that the reinforcing members of (1) are connected.

This makes it possible to favorably increase the rigidity of the joint portion.
As another aspect, it is preferable that at least one point of the reinforcing member is coupled to the first side member via the second side member at the coupling portion.
With this, the force applied to the first side member is transmitted to the reinforcing member via the second side member, so that the rigidity of the coupling portion can be improved more favorably.

According to the side member unit of the present invention, the second side member of the side member unit is formed with a recessed portion that is recessed toward the inner side in the left-right direction of the second side member, thereby increasing the rigidity of the coupling portion in the side member unit. The first side member can be enhanced by forming the recessed portion from the end portion of the second side member on the side of the joint portion when viewed in the vehicle front-rear direction, and extending outward from the joint portion in the vehicle front-rear direction. Since the communication passage is formed between the second side member and the second side member, the electrodeposition coating in the production process can reach the details inside the side member unit, and the rust prevention can be improved.

This makes it possible to provide the rigidity and rustproof property of the connecting portion between the first side member and the second side member.

FIG. 3 is a perspective view of the vehicle body seen from the lower right of the front of the vehicle. It is a perspective view of the side member unit seen from the vehicle front slanting lower right. FIG. 3 is an exploded perspective view of the side member unit as viewed from the front lower right of the vehicle. FIG. 3 is a cross-sectional view taken along the line I-I in FIG. 2.

An embodiment of the present invention will be described below with reference to the drawings.
Referring to FIG. 1, there is shown a perspective view of the vehicle body 3 as seen from the lower right front of the vehicle.
The vehicle body 3 that forms the skeleton of the vehicle 1 is a so-called monocoque body that includes a floor panel 11, a dash panel 13, and a side member unit 15. The floor panel 11 is a panel member that extends in the vehicle front-rear direction and the left-right direction, and the left and right end portions are welded with, for example, a pair of left and right side sills 21 and other frame members. A pillar member such as a center pillar 23 extending in the vehicle vertical direction is welded to the side sill 21.

The dash panel 13 is a panel member welded to the front end of the floor panel 11 in the vehicle front-rear direction, and is formed so as to extend upward from the floor panel 11 in the vehicle up-down direction to form the rear surface of the engine room (not shown). .. Skeleton members such as front pillars 25 are welded to the left and right ends of the dash panel 13, for example. Although not shown, the front pillar 25 extends further upward to form a pillar member.

Therefore, by providing the floor panel 11, the center pillar 23, and the skeletal members such as the front pillar 25 on the upper side of the floor panel 11, it is possible to dispose windows, doors, and the like (not shown). In this way, the vehicle interior is formed on the upper side of the floor panel 11 so as to be partitioned from the engine room and the outside of the vehicle 1 by disposing the dash panel 13, windows, doors, and the like.

Referring to FIG. 2, a perspective view of the side member unit 15 is shown as viewed obliquely from the lower right of the front of the vehicle, and FIG. 3 is an exploded perspective view of the side member unit 15 in FIG. Further, referring to FIG. 4, a cross-sectional view of the II cross section in FIG. 2 is shown.
The side member units 15 are a pair of left and right skeleton members that are formed on both sides of the floor panel 11 on the lower side in the vehicle left-right direction and extend in the vehicle front-rear direction. The side member unit 15 has a front side member (first side member) 31 and a floor side member (second side member) 33. Hereinafter, the side member unit 15 on the right side in the vehicle left-right direction will be described, but the left side member has the same configuration, and a description thereof will be omitted here.

The front side member 31 is a skeletal member whose front end is attached to a front cross member (not shown) located on the vehicle front side and whose rear end is connected to the front end of the floor side member 33. The front side member 31 is formed in a hat shape when viewed in cross section. Specifically, a lower outer wall portion 41 forming the lower end of the front side member 31, a right outer wall portion 43 extending upward from a right end portion of the lower outer wall portion 41, and an upper portion extending from a left end portion of the lower outer wall portion 41. The left outer wall portion 45, the right outer wall portion 43, and the welding surface 47 formed on the upper ends of the left outer wall portion 45 are formed.

The floor side member 33 is attached to a rear side member (not shown) whose rear end is located on the rear side of the vehicle, and its front end extends from the rear end of the front side member 31 forward to a position separated by a first distance and overlaps with the front side member 31. It is a skeleton member that is bonded as described above. Hereinafter, a portion where the front side member 31 and the floor side member 33 overlap each other is referred to as a coupling portion 32. The floor side member 33, like the front side member 31, is formed in a hat shape when viewed in cross section.

Specifically, a lower inner wall portion 51 forming the lower end of the floor side member 33, a right inner wall portion (side surface) 53 extending upward from a right end portion of the lower inner wall portion 51, and a left inner end portion of the lower inner wall portion 51 upward. The left inner wall portion (side surface) 55 extending toward the right inner wall portion 53 and the welding surface 57 formed on the upper ends of the left inner wall portion 55 are formed. In the floor side member 33, the lower inner wall portion 51 contacts the upper surface of the lower outer wall portion 41, the right inner wall portion 53 contacts the left surface of the right outer wall portion 43, and the left inner wall portion 55 contacts the right surface of the left outer wall portion 45. Positioned to abut.

Here, the front side member 31 is formed with a first position defining hole 61 and a bead 63. The first position defining hole 61 is a round hole provided in the lower outer wall portion 41, and in the step of welding the welding surface 47 of the front side member 31 to the lower surface of the floor panel 11, for example, by inserting a jig, the floor This is a so-called location hole for defining the relative positional relationship between the panel 11 and the front side member 31.

The bead 63 is formed by lining the lower outer wall portion 41 downward and arranging two beads side by side. The bead 63 extends from the rear of the first position defining hole 61 of the lower outer wall portion 41 toward the rear end of the lower outer wall portion 41 and is open. That is, the bead 63 is formed from the front end to the rear end of the coupling portion 32. Thereby, the bead 63 can increase the rigidity of the lower outer wall portion 41 of the front side member 31. In particular, since the bead 63 is formed to extend in the vehicle front-rear direction, it is possible to increase the rigidity in a direction in which the lower outer wall portion 41 is twisted about the vehicle front-rear direction, for example.

Further, the floor side member 33 is formed with a second position defining hole 71 and an inner recess (recess) 73. The second position defining hole 71 is a round hole provided in the lower inner wall portion 51, and in the step of welding the welding surface 57 of the floor side member 33 to the lower surface of the floor panel 11, for example, by inserting a jig, the floor This is a so-called location hole for defining the relative positional relationship between the panel 11 and the floor side member 33.

The inner recess 73 is a recess having a side surface 75 and an upper surface 77, and is formed below the right inner wall portion 53 and the left inner wall portion 55 of the floor side member 33 in the vehicle front-rear direction to extend to the lower end of the floor side member 33. There is. The inner recess 73 is also formed in the left inner wall 55 of the floor side member 33 in the same manner, and the description of the inner recess 73 formed in the left inner wall 55 will be omitted.

The side surface 75 has a parallel portion 75a and an inclined portion 75b. The parallel portion 75a is formed so as to extend in parallel from the position corresponding to the rear end of the front side member 31 toward the front end of the floor side member 33 from the rear side while being separated from the right outer wall portion 43 by the second distance. The inclined portion 75b is formed to extend toward the right outer wall portion 43 from the rear end of the parallel portion 75a toward the rear.

The upper surface 77 is a surface that is located at the upper ends of the parallel portion 75a and the inclined portion 75b and constitutes the upper surface of the inner recessed portion 73, and is parallel to the lower inner wall portion 51 at a position separated from the lower inner wall portion 51 by a third distance. It is formed to extend.
That is, the inner concave portion 73 is formed in the front-rear direction so as to include the positions corresponding to the front end and the rear end of the coupling portion 32. Thereby, the rigidity of the coupling portion 32 can be increased. Further, since the inner recess 73 has the parallel portion 75a extending parallel to the right outer wall portion 43 and the upper surface 77 extending parallel to the lower inner wall portion 51, the right inner wall portion 53 and the lower inner wall of the floor side member 33 are formed. The rigidity of the front end portion of the portion 51 can be increased.

Furthermore, since the inner concave portion 73 is formed with the inclined portion 75b, the inclined portion 75b can be moved to the left and right of the vehicle even when the vehicle 1 is subjected to a frontal collision and a shock is applied to the coupling portion 32 in the vehicle front-rear direction. Since the front side member 31 receives an impact in the front-rear direction on the side member unit 15 since it is inclined outward in the direction, it is possible to suppress stress concentration from occurring in the inner concave portion 73.

In particular, the bead 63 and the inner recess 73 are positioned so as to overlap with each other at the joint portion 32. Thereby, the rigidity of the joint portion 32 of the front side member 31 and the floor side member 33 can be further increased.
A reinforcing member 80 is attached to the floor side member 33. The reinforcing member 80 is a flat plate member including a lower end wall 81 facing in the vertical direction, a right end wall 82 extending upward from the right end of the lower end wall 81, and a left end wall 83 extending upward from the left end of the lower end wall 81. Further, the reinforcing member 80 has a third position defining hole 84 in the lower end wall 81. Furthermore, in the reinforcing member 80, the lower projection 81 is formed on the lower end wall 81, the right projection 86 is formed on the right end wall 82, and the left projection 87 is formed on the left end wall 83.

The third position defining hole 84 is a round hole provided in the lower end wall 81, and is a so-called location hole for defining a relative positional relationship between the front side member 31 and the third position defining hole 84.
The lower convex portion 85 is formed at each of the front end portion and the rear end portion of the lower end wall 81 by being recessed downward by a fourth distance so as to have a semicircular shape when viewed from above. The lower convex portion 85 has a contact surface at the lower end that comes into surface contact with the upper surface of the lower inner wall portion 51 of the floor side member 33.

The right convex portion 86 is formed at the center and the rear end of the right end wall 82 in the vehicle front-rear direction so as to protrude in the right direction (outward direction of the cross section) by the fourth distance. The right convex portion 86 has a contact surface at the right end that makes surface contact with the left surface of the right inner wall portion 53 of the floor side member 33. Similar to the right convex portion 86, the left convex portion 87 is formed at the center of the left end wall 83 in the vehicle front-rear direction and the rear end portion so as to project leftward by the fourth distance, and is in surface contact with the right surface of the left inner wall portion 55. Has a contact surface.

By the way, between the lower side wall 33 of the floor side member 33 and the lower surface of the lower inner wall portion 51, the above-mentioned bead 63 dents the lower outer wall portion 41 downward, and extends toward the rear end of the lower outer wall portion 41 to open. Therefore, the first communication passage 63a is formed. Further, between the lower outer wall portion 41 and the right outer wall portion 43 and the inner recess portion 73, the parallel portion 75a of the side surface 75 is separated from the right outer wall portion 43 by the second distance, and the upper surface 77 is separated from the lower outer wall portion 41 by the second distance. Since they are separated by 3 distances, the second communication passage 73a is formed. Furthermore, since the lower convex portion 85, the right convex portion 86, and the left convex portion 87 are formed between the reinforcing member 80 and the floor side member 33 by being recessed by the fourth distance, the third communicating passage 80a is formed. Has been formed.

That is, in the first communication passage 63a, the front end of the bead 63 is opened inside the side member unit 15 and the rear end is opened outside the vehicle, and the second communication passage 73a is opened in the front end of the inner recess 73. To the inside of the side member unit 15 and the rear side to the outside of the vehicle, respectively, and the third communicating path 80a is inside the side member unit 15 between the lower convex portion 85, the right convex portion 86, and the left convex portion 87, respectively. By opening the second position defining holes 71 to the outside of the vehicle, the inside and the outside of the front side member 31 and the floor side member 33 communicate with each other in a drainable manner.

Therefore, even in the case where the vehicle 1 travels in a puddle, for example, water rolled up by a wheel (not shown) enters the inside of the side member unit 15 through the first position defining hole 61 and the second position defining hole 71. The first communication passage 63a, the second communication passage 73a, and the third communication passage 80a can discharge water from the inside of the side member unit 15. As a result, it is possible to prevent the floor panel 11 and the side member unit 15 from rusting due to long-term water accumulation and high humidity inside the side member unit 15.

According to FIGS. 2 and 4, the front side member 31, the floor side member 33, and the reinforcing member 80 are fixed by spot welding so as to include the first welding point wp1 to the tenth welding portion wp10. Specifically, the reinforcing member 80 includes the front end of the right end wall 82 and the right convex portion 86 and the right inner wall portion 53, the front end of the left end wall 83 and the left convex portion 87, the left inner wall portion 55, and the lower convex portion 85 on the vehicle front-rear direction rear side. And the lower inner wall portion 51 are welded to each other (wp1 to wp4 in FIG. 2).

The front side member 31 includes a rear end of the lower outer wall portion 41, a lower inner wall portion 51, a lower convex portion 85 on the front side in the vehicle front-rear direction, a right outer wall portion 43 and a right inner wall portion 53, a left outer wall portion 45 and a left inner wall portion 55. Each is welded (wp5 to wp10 in FIGS. 2 and 4). Further, the fifth welding point wp5, the sixth welding point wp6, and the seventh welding point wp7 in FIG. It is a position sandwiched between them.

Accordingly, the front side member 31, the floor side member 33, and the reinforcing member 80 can be attached by welding without blocking the first communication passage 63a, the second communication passage 73a, and the third communication passage 80a. Further, the front side member 31, the floor side member 33, and the reinforcing member 80 are provided with fifth welding points wp5, sixth welding points wp6, and seventh welding points wp7 at positions sandwiched between the beads 63 arranged in the vehicle left-right direction. Thus, it is possible to prevent the stress concentration from occurring at each welding point by providing each welding point at a position in the lower outer wall portion 41 where rigidity is increased by the bead 63 and bending of the lower outer wall portion 41 is unlikely to occur. ..

Here, in the production process, after the front side member 31, the floor side member 33, and the reinforcing member 80 are welded in this manner, the welding surfaces 47 and 57 are welded and attached to the floor panel 11 or the like to attach the side surface to the vehicle body 3. Mount the member unit 15.
After that, in the production process, after the side member unit 15 and other members such as a frame member constituting the vehicle body 3 are attached to the vehicle body 3, the vehicle body 3 is put into a paint tank in which the paint is stored, and The so-called electro-deposition coating is performed in which the anti-corrosion paint is sufficiently adhered to energize. At this time, since the first communication passage 63a, the second communication passage 73a, and the third communication passage 80a are provided, the paint can be infiltrated into the details inside the side member unit 15.

As described above, in the side member unit according to the present invention, the front side member 31 formed to extend in the vehicle front-rear direction on the lower side of the vehicle body 3 in the vehicle 1 and the vehicle body 3 lower side coupled to the rear portion of the front side member 31. In the side member unit 15 including a floor side member 33 formed to extend in the vehicle front-rear direction on the side, the side member unit 15 has a joint portion in which the floor side member 33 is overlapped and coupled inside the front side member 31. The floor side member 33 has an inner recess 73 that is recessed inward in the left-right direction of the floor side member 33 in the right inner wall portion 53 and the left inner wall portion 55 of the floor side member 33. It is characterized in that it is formed so as to extend from the front end of the floor side member 33 to the rear of the joint portion 32 in the vehicle front-rear direction.

Therefore, the floor side member 33 of the side member unit 15 is formed with an inner recess 73 that is recessed inward in the left-right direction of the floor side member 33, and the inner recess 73 extends from the front end of the floor side member 33 in the vehicle front-rear direction. By being formed to extend rearward from 32, the rigidity of the coupling portion 32 in the side member unit 15 can be increased.
Further, since the second communication passage 73a is formed between the front side member 31 and the floor side member 33, the paint for electrodeposition coating in the production process reaches the details inside the side member unit 15 and enhances rust prevention. be able to.

The inner recess 73 is formed below the right inner wall portion 53 and the left inner wall portion 55 of the floor side member 33 in the vehicle vertical direction and extends to the lower inner wall portion 51 of the floor side member 33. The side member 33 is joined at least above the right inner wall portion 53 and the left inner wall portion 55 in the vehicle vertical direction.
Therefore, for example, even when water enters the inside of the side member unit 15 as the vehicle 1 travels in a puddle, the inner concave portion 73 formed up to the lower inner wall portion 51 on the lower side of the floor side member 33. The drainage of water inside the side member unit 15 can be enhanced by the communication passage.

Further, a parallel portion 75a extending in the vehicle front-rear direction from the front end of the floor side member 33 to the joint portion 32 in parallel with the vehicle front-rear direction, and an inclined portion 75b inclined toward the vehicle left-right direction outer side from the joint portion 32 rearward in the vehicle front-rear direction. And have.
Therefore, for example, even when a shock is applied to the coupling portion 32 in the vehicle front-rear direction due to the front collision of the vehicle 1, the inclined portion 75b inclines outward in the vehicle left-right direction, so that the side member unit 15 impacts in the front-rear direction. Since the floor side member 33 can receive the stress, it is possible to prevent stress concentration from occurring in the inner concave portion 73.

A bead 63 is formed on the lower surface of the coupling portion 32 of the front side member 31 so as to extend downward in the vehicle vertical direction and extend in the vehicle longitudinal direction.
Therefore, the bead 63 is formed on the lower inner wall portion 51 of the front side member 31 at a position corresponding to the joint portion 32, so that the position corresponding to the joint portion 32 of the front side member 31 does not interfere with the floor side member 33. The lower inner wall 51 can be reinforced.

Further, the bead 63 is formed to extend forward of the vehicle front-rear direction from the joint portion 32, so that the bead 63 is formed straddling the front end portion of the floor side member 33 inside the front side member 31, so that an impact is generated. The part of the front side member 31 to be added can be reinforced.
Further, even when water enters the inside of the side member unit 15, the inside of the side member unit 15 is formed by the first communication passage 63a of the bead 63 formed to the front end of the lower inner wall portion 51 of the floor side member 33. It is also possible to further improve the drainage of water.

The two beads 63 are formed side by side in the vehicle left-right direction, and the front side member 31 and the floor side member 33 are joined at a position sandwiched by the beads 63, whereby the lower outer wall of the front side member 31 is joined. The welding force wp5 is a force that enhances the rigidity of the portion 41 in a direction in which the vehicle front-rear direction is twisted about the axis and separates the lower outer wall portion 41 of the front side member 31 from the lower inner wall portion 51 of the floor side member 33. 7 can be suppressed.

Then, inside the floor side member 33, a plate-shaped reinforcing member 80 extending along the inner recess 73 of the floor side member 33 and the lower surface from the rear of the inner recess 73 of the floor side member 33 to the coupling portion 32 in the vehicle front-rear direction. By coupling the, the rigidity of the coupling portion 32 can be satisfactorily enhanced.
Further, at least one point of the reinforcing member 80 is connected to the front side member 31 via the floor side member 33 at the connecting portion 32, so that the force applied to the front side member 31 is increased via the floor side member 33. Since it is transmitted to 80, the rigidity of the coupling part 32 can be improved more favorably.

Although the side member unit according to the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be modified without departing from the gist of the invention.
For example, in the present embodiment, the connection between the front side member 31 and the floor side member 33 has been described, but it may be applied to the connection between the floor side member 33 and a rear side member (not shown).

Further, in the present embodiment, the inner concave portion 73 is formed in the right inner wall portion 53 and the left inner wall portion 55 so as to extend to the lower inner wall portion 51, but a bead-shaped concave portion is formed in the right inner wall portion 53 or the left inner wall portion 55. Alternatively, it may not be formed so as to extend to the lower inner wall portion 51.
In addition, although the welding points wp1 to wp10 have been described in the present embodiment, the positions thereof may be appropriately changed, may not be spot welding, and may be fixed by bolt fastening or the like.

1 vehicle 3 vehicle body 15 side member unit 31 front side member (first side member)
32 coupling part 33 floor side member (second side member)
53 Right inner wall (side)
55 Left inner wall (side)
63 bead 73 inner recess (recess)
75 side surface 77 upper surface 80 reinforcing member

Claims (8)

A first side member formed below the vehicle body of the vehicle and extending in the vehicle front-rear direction;
A side member unit, comprising: a second side member, which is connected to a rear portion of the first side member and extends in the vehicle front-rear direction on the lower side of the vehicle body,
The side member unit has a coupling part in which the second side member is overlapped and coupled inside the first side member,
The second side member has a recess formed on a side surface of the second side member, the recess being recessed inward in the left-right direction of the second side member.
The recess is a side member unit formed to extend from the front end of the second side member to the rear of the coupling portion in the vehicle front-rear direction. The recess is formed below the side surface of the second side member in the vehicle up-down direction and extends to the lower end of the second side member, and the first side member and the second side member are at least the side surface vehicle. The side member unit according to claim 1, wherein the side member unit is coupled on the upper side in the vertical direction. The recess includes a parallel portion that extends in the vehicle front-rear direction from the front end of the second side member to the coupling portion in parallel with the vehicle front-rear direction, and an inclination that is inclined outward in the vehicle left-right direction from the coupling portion toward the vehicle front-rear direction rear side. The side member unit according to claim 1 or 2, further comprising: The side member unit according to any one of claims 1 to 3, wherein a bead that is recessed downward in the vehicle vertical direction and extends in the vehicle front-rear direction is formed on the lower surface of the coupling portion of the first side member. The side member unit according to claim 4, wherein the bead is formed so as to extend forward of the vehicle front-rear direction from the coupling portion. The said bead is formed in parallel in the vehicle left-right direction, and the said 1st side member and the said 2nd side member are couple|bonded at the position pinched|interposed by the said bead at least, The Claim 4 or 5 is described. Side member unit. Inside the second side member, a plate-shaped reinforcing member that extends along the concave portion and the lower surface of the second side member from the rear of the concave portion of the second side member to the coupling portion in the vehicle front-rear direction is coupled. The side member unit according to any one of claims 2 to 6. The side member unit according to claim 7, wherein at least one point of the reinforcing member is coupled to the first side member via the second side member at the coupling portion.

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