JP6783718B2 - Body lower member and its manufacturing method - Google Patents

Description

The present invention relates to a member constituting a lower portion of a vehicle body of a vehicle such as an automobile, which extends in the front-rear direction on both sides in the width direction of the vehicle body, and a method for manufacturing the same.

The body of a vehicle such as an automobile is generally a member constituting the lower portion thereof, and includes a member called a so-called rocker (or side sill). The members are arranged on both sides in the width direction of the vehicle body and extend in the front-rear direction below the side door.

As described above, as a member constituting the lower part of the vehicle body, for example, a member described as a side frame in Patent Document 1 is known. The side frame is composed of an inner member and an outer member arranged so as to be arranged in a horizontal direction parallel to the width direction of the vehicle body. Each of the inner member and the outer member extends in the front-rear direction of the vehicle body and has a hollow closed cross section surrounding a substantially rectangular internal space when viewed from the front-rear direction. The required bending rigidity is ensured by joining the inner member and the outer member in the lateral direction to each other.

Japanese Unexamined Patent Publication No. 4-293679

In addition to the flexural rigidity, a vehicle body lower member such as the rocker is required to have high impact absorption performance at the time of a side collision. That is, when there is a side collision with the vehicle body, so-called side collision, it is desirable to effectively absorb the impact energy by deformation of the vehicle body lower member, thereby ensuring the safety of the occupant. Is done.

On the other hand, the vehicle body lower member as described in Patent Document 1 is composed of an inner member and an outer member having a simple hollow closed cross section, and therefore efficiently absorbs the impact energy in the side collision. It's difficult. Therefore, in order to absorb the impact energy, there is a possibility that the setting of the wall thickness and the selection of the material are significantly restricted, and the weight of the member is increased or the cost is significantly increased.

In view of the above circumstances, it is an object of the present invention to provide a vehicle body lower member having a lightweight and low-cost structure and capable of effectively absorbing impact energy at the time of a side collision, and a method for manufacturing the same.

Provided are a vehicle body lower member extending in the front-rear direction of the vehicle body to form a lower portion of the vehicle body, a first member extending in the front-rear direction of the vehicle body, and the first member extending in the front-rear direction of the vehicle body. It includes a member and a second member arranged so as to be arranged in a horizontal direction parallel to the width direction of the vehicle body and joined to the first member. The first member includes a first outer vertical wall that extends in the vertical direction in a cross section that is a cross section seen from the front-rear direction of the vehicle body and is arranged at a position that is separated from the second member in the horizontal direction. They are arranged at intervals in the vertical direction, and each has a plurality of first horizontal walls extending in the horizontal direction from the first outer vertical wall toward the second member in the cross section. The plurality of first horizontal walls include a first upper horizontal wall connected to an upper end portion of the first outer vertical wall so as to connect the upper end portion of the first outer vertical wall and the second member, and the first outer vertical wall. Includes a first lower horizontal wall that connects to the lower end of the first outer vertical wall so as to connect the lower end of the wall to the second member. The second member is arranged with a second outer vertical wall extending in the vertical direction in the cross section and arranged at a position separated from the first member in the horizontal direction at a vertical interval. A plurality of second horizontal walls extending from the second outer vertical wall toward the first member in the cross section, and extending in the vertical direction in the cross section and closer to the first member than the second outer vertical wall. It has a second inner vertical wall, which is arranged at a position. The plurality of second horizontal walls include a second upper horizontal wall connected to the upper end of the second outer vertical wall so as to connect the upper end of the second outer vertical wall and the first member, and the second outer vertical wall. It includes a second lower horizontal wall connected to the lower end of the second outer vertical wall so as to connect the lower end of the wall and the first member, and at least one second inner horizontal wall. The second inner vertical wall is connected to the second upper horizontal wall and the second lower horizontal wall so as to connect the second upper horizontal wall and the second lower horizontal wall in the vertical direction. The at least one second inner horizontal wall connects the second outer vertical wall and the second inner vertical wall in the horizontal direction in a region between the second upper horizontal wall and the second lower horizontal wall. In the cross section, the buckling deformation occurs when the second outer vertical wall and the second inner vertical wall are connected to each other in the horizontal direction and a certain amount or more of the horizontal load is applied to the second member. It has a thickness that can be used.

Here, "extending in the vertical direction" for each vertical wall does not mean to limit that the vertical wall is a wall completely parallel to the vertical direction, but to the extent that a load in the vertical direction can be received. The purpose is to include those extending in the vertical direction while tilting with respect to the vertical direction. Similarly, in each lateral wall, "extending in the lateral direction does not mean that the lateral wall is a wall completely parallel to the lateral direction, but in the lateral direction to the extent that a load in the lateral direction can be received. The purpose is to include those that extend in the lateral direction while tilting.

Further, with respect to the first upper horizontal wall, "connecting the upper end portion of the first outer vertical wall and the second member" is limited to those in which the first upper horizontal wall is directly joined to the second member. However, the purpose is to include those in which the first upper lateral wall is indirectly connected to the second member via another part of the first member. This also applies to the first lower horizontal wall, the second upper horizontal wall, and the second lower horizontal wall.

In the vehicle body lower member, the first outer vertical wall, the second outer vertical wall, and the second inner vertical wall included in the first and second members contribute to ensuring bending rigidity in the vertical direction, and the first member In addition to the first upper side wall and the first lower side wall and the second upper side wall and the second lower side wall of the second member, the second member is the second member in the area between the second upper side wall and the second lower side wall. 2 Including at least one second inner horizontal wall connecting the inner vertical wall and the second outer vertical wall in the lateral direction of the vehicle body lower member without significantly increasing the wall thickness of the first and second members. In addition to improving the flexural rigidity of the body, it enables effective absorption of impact energy given to the second member at the time of a side collision. Specifically, the at least one second inner lateral wall can be effectively absorbed by impact energy by buckling and deforming due to the lateral impact load applied to the second member at the time of the side collision. It is possible.

In the vehicle body lower member, the first member is a first inner vertical wall that extends in the vertical direction in the cross section and is arranged at a position closer to the second member than the first outer vertical wall. The first upper horizontal wall and the first lower horizontal wall are further provided with a first inner vertical wall connected to the first upper horizontal wall and the first lower horizontal wall so as to connect the first upper horizontal wall and the first lower horizontal wall in the vertical direction. The horizontal wall is formed in the horizontal direction in the cross section so as to connect the first outer vertical wall and the first inner vertical wall in the horizontal direction in the region between the first upper horizontal wall and the first lower horizontal wall. A thickness that extends to connect the first outer vertical wall and the first inner vertical wall and can be buckled and deformed when a certain amount or more of the lateral load is applied to the first member. It is preferable to further include at least one first inner side wall having.

The first inner vertical wall of the vehicle body lower member makes it possible to further increase the bending rigidity of the entire vehicle body lower member in the vertical direction. Further, the at least one first inner horizontal wall connecting the first inner vertical wall and the first outer vertical wall in the region between the first upper horizontal wall and the first lower horizontal wall is added at the time of the side collision. By buckling and deforming due to the impact load in the lateral direction, it is possible to more effectively absorb the impact energy in combination with the second inner lateral wall.

The at least one second inner horizontal wall is one of the plurality of first horizontal walls in which at least a part of the inner end portion of the end portion of the second inner horizontal wall connected to the second vertical inner wall is. The second inner horizontal wall is arranged at a height position that overlaps with the inner end of the first horizontal wall, which is one end and is closer to the second member, in the vertical direction. However, it is preferable. This facilitates load transmission between the second inner side wall and any first side wall in the first member and enables more effective absorption of impact energy.

When the at least one second inner side wall includes a plurality of second inner side walls arranged at intervals in the vertical direction, at least one said inner end portion of the plurality of second inner side walls is a plurality of first side walls. It is preferable that the second inner side wall is arranged at a height position that overlaps with the inner end portion of any one of the first side walls in the vertical direction. Further, a height at which at least a part of the inner end portion of each of the plurality of second inner side walls overlaps the inner end portion of the first side wall of any one of the plurality of first side walls in the vertical direction. By arranging each of the plurality of second inner side walls at the vertical position, more effective absorption of impact energy becomes possible.

Here, when the first member includes the at least one first inner side wall, at least a part of the inner end portion of the at least one second inner side wall is the at least one first. 1 It is preferable to arrange the inner side wall at a height position that overlaps with the inner end portion in the vertical direction. The at least one second inner side wall, or at least a part of the inner end of the second inner side wall, is above and below the inner end of any one of the first upper side wall and the first lower side wall. It may be arranged at height positions that overlap with respect to the direction.

In the present invention, the first member constitutes an inner member arranged at a position inside the vehicle body width direction with respect to the second member, and the second member is outside the vehicle body width direction with respect to the first member. It is preferable to configure the outer member arranged at the position of. In this arrangement, the load applied to the lower part member of the vehicle body at the time of a side collision is first transmitted to the at least one second inner side wall of the second member to buckle and deform the second inner side wall, that is, the impact energy is initially set. Allows for large absorption in stages. This allows for more effective absorption of the impact energy.

Here, when the first member includes the at least one first inner side wall, the at least one second inner side wall may have a shape of buckling with a load smaller than that of the at least one first inner side wall. ,preferable. This makes it possible for the second inner side wall located outside the first inner side wall in the vehicle body width direction to buckle and deform in advance of the first inner side wall, whereby the impact energy is more effective. Enables absorption.

The first member and the second member are preferably made of an extruded material made of an aluminum alloy. This makes it possible for each of the first member and the second member to have a uniform and integral cross-sectional shape in the longitudinal direction (front-rear direction of the vehicle body) while reducing the weight of the entire vehicle body lower member. To.

In this case, of the first member and the second member, those constituting the outer member arranged outside in the vehicle body width direction are made of a 6000 series aluminum alloy (Al—Mg—Si based aluminum alloy), and the above. Of the first member and the second member, those constituting the inner member arranged inside in the vehicle body width direction are preferably made of a 7000 series aluminum alloy (for example, Al—Zn—Mg based aluminum alloy). As described above, the outer member is made of a 6000 series aluminum alloy that is less likely to cause stress corrosion cracking, and the inner member is made of a high-strength 7000 series aluminum alloy, which is high in corrosion resistance and weight reduction. It enables both to ensure strength.

In this case, it is preferable that the lower end of the outer member is located below the lower end of the inner member over the entire area in the longitudinal direction of the outer member. This makes it possible to prevent rainwater or the like from entering the inner member through the lower part of the outer member and effectively suppress the corrosion of the inner member.

Similarly, it is preferable that the upper end of the outer member is located above the upper end of the inner member over the entire longitudinal direction of the outer member. This makes it possible to prevent rainwater or the like from entering the inner member through above the outer member and effectively suppress corrosion of the inner member.

In the present invention, a place where fixing is performed for joining the first member and the second member (for example, a place where riveting or welding is performed) can be freely set. Preferably, the first member projects outward in the vertical direction from the inner end of at least one of the first upper horizontal wall and the first lower horizontal wall, which is closer to the second member. It is preferable that the flange portion is provided and the flange portion is fixed to the second member in a state where the flange portion is in surface contact with the second member in the lateral direction. This makes it possible to stably join the first member and the second member, and to facilitate the work for the joining.

The present invention also provides a method for manufacturing the vehicle body lower member. In this method, a step of extruding the first member using an aluminum alloy, a step of extruding the second member using an aluminum alloy, and a step of extruding the first member and the second member in the lateral direction Includes a step of forming the vehicle body lower member by arranging them side by side and joining them to each other.

As described above, according to the present invention, there is provided a vehicle body lower member having a lightweight and low-cost structure and capable of effectively absorbing impact energy at the time of a side collision, and a method for manufacturing the same.

It is a side view which shows the example of the arrangement of the vehicle body lower part member which concerns on embodiment of this invention. It is a cross-sectional view of the lower part member of the vehicle body which concerns on 1st Embodiment of this invention, and is the figure which shows the cross section along the line II-II of FIG. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 2nd Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 3rd Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 4th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 5th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 6th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 7th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 8th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 9th Embodiment of this invention. It is a figure which shows the cross section of the vehicle body lower part member which concerns on 10th Embodiment of this invention.

Preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of arrangement of the locker 2 according to each embodiment described below. The rocker 2 shown in the figure is a vehicle body lower member that constitutes a lower portion of the vehicle body (body) together with a cross member and the like (not shown). The rockers 2 are arranged on the left and right sides in the width direction of the vehicle body (depth direction in FIG. 1), and extend in the front-rear direction (left-right direction in FIG. 1) at a height position below the side door (not shown). The cross member connects the rockers 2 to the left and right. The lower end of the B pillar 4 extending in the vertical direction is connected to an appropriate portion of each rocker 2. In the example shown in FIG. 1, the front end and the rear end of each rocker 2 are connected to the front and rear die-cast members 6 and 8, respectively.

FIG. 2 shows a cross section of the rocker 2 according to the first embodiment of the present invention. The cross section is a cross section of the rocker 2 viewed from the front-rear direction of the vehicle body, and is, for example, a cross section along the line II-II shown in FIG.

The locker 2 includes a first member 10 and a second member 20. Each of the first and second members 10 and 20 is a member that extends in the front-rear direction of the vehicle body and has a uniform cross section in the front-rear direction, and is composed of, for example, an extruded material made of an aluminum alloy.

The first member 10 and the second member 20 are arranged side by side in the lateral direction (left-right direction in FIG. 2) parallel to the width direction of the vehicle body, and are joined to each other to form the rocker 2. In this embodiment, the first member 10 constitutes an inner member arranged inside the second member 20 in the vehicle body width direction, and the second member 20 has a vehicle body width wider than that of the first member. It constitutes an outer member arranged outside in the direction.

The first member 10 integrally includes a first outer vertical wall 12 and a plurality of first horizontal walls.

The first outer vertical wall 12 extends in the vertical direction in the cross section, and is arranged at a position separated from the second member 20 in the horizontal direction (left in FIG. 2).

The plurality of first lateral walls include a first upper lateral wall 16a and a first lower lateral wall 16b in this embodiment. The first upper horizontal wall 16a and the first lower horizontal wall 16b are directed toward the second member 20 (to the right in FIG. 2) from the upper end and the lower end of the first outer vertical wall 12, respectively. Extend to. The first upper horizontal wall 16a is connected to the upper end of the first outer vertical wall 12 so as to connect the upper end of the first outer vertical wall 12 and the second member 20, and similarly, the first lower. The horizontal wall 16b is connected to the lower end of the first outer vertical wall 12 so as to connect the lower end of the first outer vertical wall 12 and the second member 20.

In the cross section, a curved portion that smoothly connects the first outer vertical wall 12, the first upper horizontal wall 16a, and the second lower horizontal wall 16b with an appropriate radius of curvature may be provided. .. This also applies to other embodiments described later.

The second member 20 integrally includes a second outer vertical wall 22, a second inner vertical wall 24, and a plurality of second horizontal walls.

The second outer vertical wall 22 extends in the vertical direction in the cross section and is arranged at a position separated from the second member 20 in the horizontal direction (to the right in FIG. 2). The second inner vertical wall 24 extends in the vertical direction in the cross section and is closer to the first member 10 than the second outer vertical wall 22. In this embodiment, the second inner vertical wall 24 is in contact with the first member 10. It will be placed in possible positions.

The plurality of second side walls include a second upper side wall 26a, a second lower side wall 26b, and a second inner side wall 26c in this embodiment. The second upper horizontal wall 26a, the second lower horizontal wall 26b, and the second inner horizontal wall 26c are directed toward the first member 10 from the upper end portion and the lower end portion of the second outer vertical wall 22, respectively (left in FIG. 2). (Towards) said laterally. The second upper horizontal wall 26a is connected to the upper end of the second outer vertical wall 22 so as to connect the upper end of the second outer vertical wall 22 and the first member 10, and similarly, the second lower. The horizontal wall 26b is connected to the lower end of the second outer vertical wall 22 so as to connect the lower end of the second outer vertical wall 22 and the first member 10.

Also in the second member 20, in the cross section, the second outer vertical wall 22 and the second upper horizontal wall 26a and the second lower horizontal wall 26b are smoothly connected to each other with an appropriate radius of curvature. A curved portion may be given. This also applies to other embodiments described later.

The second inner vertical wall 24 is the first member 10 of the inner ends of the second upper horizontal wall 26a and the second lower horizontal wall 26b, that is, both ends of the second upper horizontal wall 26a and the second lower horizontal wall 26b. The ends on the side closer to (the left end in FIG. 2) are connected to the inner ends of the second upper side wall 26a and the second lower side wall 26b so as to be connected to each other in the vertical direction. The second inner side wall 26c is located at a height within the region between the second upper side wall 26a and the second lower side wall 26b, preferably just between the second upper side wall 26a and the second lower side wall 26b. At the height position of, the second outer vertical wall 22 and the second inner vertical wall 24 extend in the horizontal direction in the cross section so as to connect the second outer vertical wall 22 and the second inner vertical wall 24 in the horizontal direction. It is connected to the second inner vertical wall 24.

The second inner lateral wall 26c further has a thickness capable of buckling deformation when a certain amount or more of the lateral load P is applied to the second member 20. The thickness can be freely set according to the specifications. Further, the thickness does not necessarily have to be constant in the lateral direction. In the example shown in FIG. 2, substantially equal thickness is set for each of the walls constituting the first and second members 10, 20.

In this first embodiment, the first upper horizontal wall 16a and the second upper horizontal wall 26a are arranged at the same height positions as each other, and the first lower horizontal wall 16b and the second lower horizontal wall 26b have the same height as each other. It is placed in the position. However, the height positions may be different from each other. Further, the respective lateral walls 16a, 16b, 26a to 26c extend completely parallel to the lateral direction as shown in FIG. 1, but in the lateral direction within a range in which the load in the lateral direction can be received. On the other hand, it may extend while tilting to some extent. This also applies to other embodiments described later.

In this first embodiment, the first member 10 is given a width dimension larger than the width dimension (the dimension in the lateral direction) of the second member 20. However, the width dimensions of both members 10 and 20 may be the same, or the width dimension of the first member 10 may be larger than the width dimension of the second member 20. This also applies to other embodiments described later.

The first member 10 according to the first embodiment further includes a first upper flange portion 18a and a first lower flange portion 18b, and similarly, the second member 20 has a second upper flange portion 28a and a first lower flange portion 18b. 2 Further has a lower flange portion 28b. The first upper flange portion 18a protrudes outward (upward in FIG. 2) from the inner end portion (right end portion in FIG. 2) of the first upper horizontal wall 16a, and the first lower flange portion 18b It projects outward (downward in FIG. 2) in the vertical direction from the inner end (right end in FIG. 2) of the first lower horizontal wall 16b. Similarly, the second upper flange portion 28a protrudes outward (upward in FIG. 2) from the inner end portion (left end portion in FIG. 2) of the second upper side wall 26a, and the second lower flange portion 28a. The portion 28b protrudes outward (downward in FIG. 2) in the vertical direction from the inner end portion (left end portion in FIG. 2) of the second lower horizontal wall 26b.

The first upper flange portion 18a and the second upper flange portion 28a are abutted and fixed to each other in the lateral direction, and similarly, the first lower flange portion 18b and the second lower flange portion 28b are abutted to each other in the lateral direction. Is fixed. Then, by fixing these, the first member 10 and the second member 20 are joined to each other to form a rocker 2. For the fixing, for example, a plurality of rivets 30 are struck so as to penetrate the first upper flange portion 18a and the second upper flange portion 28a at a plurality of positions arranged in the longitudinal direction of the rocker 2, and similarly, the first lower side is similarly fixed. This can be done by striking a plurality of rivets 30 so as to penetrate the flange portion 18b and the second lower flange portion 28b. Alternatively, welding may be performed along the longitudinal direction.

According to the rocker 2, the first outer vertical wall 12, the second outer vertical wall 22, and the second inner vertical wall 24 included in the first and second members 10 and 20 contribute to ensuring bending rigidity in the vertical direction. In addition to the first upper horizontal wall 16a and the first lower horizontal wall 16b of the first member 10 and the second upper horizontal wall 26a and the second lower horizontal wall 26b of the second member 20, the second member 20 is the second member. The first and second members include a second inner horizontal wall 26c that connects the second outer vertical wall 22 and the second inner vertical wall 24 in the region between the upper horizontal wall 26a and the second lower horizontal wall 26b. In addition to improving the flexural rigidity of the rocker 2 in the lateral direction, the impact energy given to the second outer vertical wall 22 at the time of a side collision is effectively absorbed without significantly increasing the wall thicknesses of 10 and 20. Makes it possible to ensure the safety of passengers. Specifically, the at least one second inner horizontal wall 26c buckles and deforms due to the lateral impact load P applied to the second outer vertical wall 22 at the time of the side collision, so that the impact energy is effectively applied. It can be absorbed.

Contrary to this embodiment, the first member 10 may form an outer member and the second member 20 may form an inner member. However, the fact that the second member 20 is arranged outside the first member 10 in the vehicle body width direction causes the impact energy applied to the rocker 2 to be applied to the second inside of the second member 20 prior to the first member 10. The lateral wall 26c allows absorption due to its buckling deformation. This allows for more effective energy absorption than when a load is applied to the first member 10 which does not have an internal lateral wall. Further, the fact that the width dimension of the second member 20 is larger than the width dimension of the first member 10 is large for the second inner side wall 26c of the second member 20 while keeping the width dimension of the rocker 2 at a predetermined dimension. It is possible to give lateral dimensions to facilitate the buckling deformation.

The above is the same in other embodiments described later.

FIG. 3 shows a cross section of the rocker 2 according to the second embodiment of the present invention. The locker 2 is obtained by adding a first inner vertical wall 14 to the first member 10 of the locker 2 according to the first embodiment. That is, the locker 2 according to the second embodiment includes the first member 10 to which the first inner vertical wall 14 is added to the first member 10 according to the first embodiment, and the first member 10. It has a second member 20 equivalent to the second member 20 according to the embodiment.

Like the second inner vertical wall 24, the first inner vertical wall 14 extends in the vertical direction in the cross section and is closer to the second member 20 than the first outer vertical wall 12. In the second embodiment, the second member 20 is arranged at a position where it can come into contact with the second inner vertical wall 24. The first inner vertical wall 14 is the second member 20 of the inner ends of the first upper horizontal wall 16a and the second lower horizontal wall 16b, that is, both ends of the first upper horizontal wall 16a and the second lower horizontal wall 16b. The ends on the side closer to (the right end in FIG. 3) are connected to the inner ends of the first upper side wall 16a and the first lower side wall 16b so as to be connected to each other in the vertical direction. The addition of the first inner vertical wall 14 makes it possible to further improve the bending rigidity of the entire rocker 2 in the vertical direction.

FIG. 4 shows a cross section of the rocker 2 according to the third embodiment of the present invention. The locker 2 according to the third embodiment is obtained by further adding a first internal horizontal wall 16c as the first horizontal wall to the first member 10 of the locker 2 according to the second embodiment. That is, the locker 2 according to the second embodiment includes the first member 10 to which the first internal lateral wall 16c is added to the first member 10 according to the second embodiment, and the first and first members. It has a second member 20 equivalent to the second member 20 according to the second embodiment.

The first inner side wall 16c, like the second inner side wall 26c, is located at a height within the region between the first upper side wall 16a and the first lower side wall 16b, preferably the first upper side wall 16a and the above. At a height position just intermediate to the first lower horizontal wall 16b, the first outer vertical wall 12 and the first inner vertical wall 14 extend in the horizontal direction in the cross section so as to connect the first inner vertical wall 14 in the horizontal direction. It is connected to the first outer vertical wall 12 and the first inner vertical wall 14.

The first inner lateral wall 16c further has a thickness capable of buckling deformation when a certain amount or more of the lateral load P is applied to the first member 10. The thickness of the first inner lateral wall 16c can also be freely set according to the specifications, and does not necessarily have to be constant in the lateral direction. In the example shown in FIG. 3, the first inner lateral wall 16c is provided with a thickness equivalent to the thickness of the other walls constituting the first and second members 10 and 20.

In the third embodiment, the first inner horizontal wall 16c that connects the first outer vertical wall 12 and the first inner vertical wall 14 in the lateral direction is seated by the impact load in the lateral direction applied at the time of the side collision. By bending and deforming, in combination with the second inner side wall 26c, it is possible to absorb impact energy more effectively.

The height positions (positions in the vertical direction) of the first inner side wall 16c and the second inner side wall 26c may be deviated from each other, but the inner end portion (left end in FIG. 4) of the second inner side wall 26c. It is preferable that the inner side walls 16c and 26c are aligned with each other so that at least a part of the first inner side wall 16c overlaps the inner end (right end in FIG. 4) in the vertical direction. This facilitates load transmission between the two inner side walls 16c and 26c (when the second member 20 is an outer member, the load is transmitted from the second inner side wall 26c to the first inner side wall 16c). Allows effective absorption of impact energy.

In the third embodiment, when the first member 10 and the second member 20 constitute an inner member and an outer member, respectively, that is, the second member 20 is on the outer side of the first member 10 in the vehicle body width direction. When arranged, the second inner side wall 26c preferably has a shape that buckles with a load smaller than that of the first inner side wall 16c. This makes it possible for the second inner side wall 26c located outside the first inner side wall 16c in the vehicle body width direction to buckle and deform in advance of the first inner side wall 16c, thereby causing an impact. Allows for more effective absorption of energy. Specifically, as shown in FIG. 4, the second member 20 is given a width dimension larger than the width dimension of the first member 10, and the second inner horizontal wall 26c is laterally larger than the first inner horizontal wall 16c. The dimensions in the direction may be given, or the second inner side wall 26c may be given a thickness smaller than the thickness of the first inner side wall 16c. Alternatively, the second member 20 may be composed of a material having a strength lower than that of the material constituting the first member 10.

The effect of improving the energy absorption performance by the overlap between the second inner side wall 26c and the first inner side wall 16c in the vertical direction is also obtained by the second inner side wall 26c overlapping with the other first side wall. It is possible to obtain. 5 to 7 show cross sections of the rocker 2 according to the fourth to sixth embodiments, which are examples thereof.

The first member 10 according to the fourth embodiment shown in FIG. 5 does not include the first vertical inner wall and the first inner horizontal wall as in the first embodiment, but the first member 10 1 By arranging the upper side wall 16a at a height equivalent to the second inner side wall 26c of the second member 20, at least a part of the inner end portion of the second inner side wall 26c is formed on the first upper side wall 16a. It overlaps the inner edge in the vertical direction. The overlap enables smooth load transmission between the second inner side wall 26c and the first upper side wall 16a. In the fourth embodiment, the second upper flange portion 28a of the second member 20 is omitted, and the first upper flange portion 18a of the first member 10 is lateral to the second inner vertical wall 24 of the second member 20. It is fixed to the second inner vertical wall 24 by a rivet 30 or other means in a state of being butted in the direction.

In the fifth embodiment shown in FIG. 6, the first inner vertical wall 14 is added to the first member 10 according to the fourth embodiment. Also in the fifth embodiment, at least a part of the inner end portion of the second inner side wall 26c overlaps with the inner end part of the first upper side wall 16a in the vertical direction, so that the second inner side wall 26c and the second inner side wall 26c It enables smooth load transmission to and from the first upper lateral wall 16a.

The first member 10 according to the sixth embodiment shown in FIG. 7 does not include the first vertical inner wall and the first inner horizontal wall, but the first lower horizontal wall 16b of the first member 10 is the second member 20. By arranging at the same height position as the second inner side wall 26c, at least a part of the inner end of the second inner side wall 26c overlaps with the inner end of the first lower side wall 16b in the vertical direction. doing. The overlap enables smooth load transmission between the second inner side wall 26c and the first lower side wall 16b. In the sixth embodiment, the second lower flange portion 28b of the second member 20 is omitted, and the first lower flange portion 18b of the first member 10 is the second inner vertical wall 24 of the second member 20. It is fixed to the second inner vertical wall 24 by a rivet 30 or other means in a state of being butted in the lateral direction.

The phrase "connecting the upper end of the second outer vertical wall and the first member" according to the second upper horizontal wall according to the present invention is not limited to the case where the first upper horizontal wall is directly joined to the second member. The second upper horizontal wall is indirectly connected to the second member via another part of the second member, for example, the second upper horizontal wall connected to the second upper horizontal wall 22 as shown in FIGS. 5 and 6. The purpose is to include those in which the horizontal wall 26a is connected to the first member 10 via the upper half of the second inner vertical wall 24. Similarly, when the second lower horizontal wall "connects the lower end of the second outer vertical wall and the first member", for example, as shown in FIG. 7, the second lower horizontal wall 26b connected to the second upper horizontal wall 22 Is intended to include those connected to the first member 10 via the lower half of the second inner vertical wall 24. This also applies to the first upper horizontal wall and the first lower horizontal wall.

The "at least one second inner side wall" of the second member according to the present invention may include a plurality of second inner side walls. In this case, the second inner side wall is arranged at a height position where at least one inner end of the plurality of second inner side walls overlaps the inner end of any of the first side walls in the vertical direction. However, it is preferable. Further, each of the plurality of second inner side walls is located at a height position at which at least a part of each inner end of the plurality of second inner side walls overlaps the inner end of any first side wall in the vertical direction. By arranging, more effective absorption of impact energy becomes possible.

FIG. 8 shows a cross section of the rocker 2 according to the seventh embodiment, which is an example of the latter. The first member 10 of the locker 2 according to the seventh embodiment is equivalent to the first member 10 according to the third embodiment shown in FIG. 4, but relates to the seventh embodiment. The second member 20 has a height dimension larger than the height dimension of the first member 10, and has a second upper inner side wall 26d and a second lower inner side wall 26e as "at least one second inner side wall". have. The second upper side wall 26a of the second member 20 is arranged at a position higher than the first upper side wall 16a of the first member 10, and the second upper inner side wall 26d and the second lower inner side wall 26e are the first. By arranging the member 10 at the same height as the first upper horizontal wall 16a and the first inner horizontal wall 16c, at least a part of the inner end portion (left end portion in FIG. 8) of the second upper inner horizontal wall 26d. Overlaps in the vertical direction with respect to at least a part of the inner end portion (right end portion in FIG. 8) of the first upper horizontal wall 16a, and the inner end portion (in FIG. 8) of the second lower inner horizontal wall 26e. At least a part of the left end portion) overlaps with at least a part of the inner end portion (right end portion in FIG. 8) of the first inner side wall 16c in the vertical direction.

In the rocker 2 according to the seventh embodiment, smooth load transmission between the second upper inner side wall 26d and the first upper side wall 16a, and the second lower inner side wall 26e and the first one. It is possible to simultaneously achieve smooth load transfer to and from the inner side wall 16c.

In the present invention, an internal vertical wall extending in the vertical direction may be appropriately added to at least one of the first and second members in order to further increase the bending rigidity in the vertical direction. FIG. 9 shows a cross section of the rocker 2 according to the eighth embodiment, which is an example thereof. The locker 2 has a first internal vertical wall 15 and a second internal vertical wall 25 added to the first member 10 and the second member 20 of the locker 2 according to the seventh embodiment, respectively. The first inner vertical wall 15 extends in the vertical direction while intersecting with the first inner horizontal wall 16c in the region between the first outer vertical wall 12 and the first inner vertical wall 14 in the cross section, whereby the first upper horizontal wall 15 is formed. The 16a and the first lower horizontal wall 16b are connected. Similarly, the second inner vertical wall 25 extends in the vertical direction while intersecting with the first inner horizontal walls 26d and 26e in the region between the second outer vertical wall 22 and the second inner vertical wall 24 in the cross section. Connects the second upper horizontal wall 26a and the second lower horizontal wall 26b.

The effect of the vertical overlap is that the inner end of the second inner lateral wall is slightly separated from the first member, that is, the second member as shown in FIG. 10 as the ninth embodiment. Also obtained when the second inner vertical wall 24 of 20 is displaced to the outside (right side in FIG. 10) from the inner end (left end in the figure) of the second upper horizontal wall 26a and the second lower horizontal wall 26b. Is possible. Alternatively, even if the first inner vertical wall 14 of the first member 10 is displaced to the outside (left side in FIG. 10) from the inner end portion (right end portion in the figure) of the first upper horizontal wall 16a and the first lower horizontal wall 16b. Good.

In the present invention, the specific form for joining the first member and the second member to each other is not limited. For example, the locker 2 according to the third embodiment shown in FIG. 4 can be modified as in the tenth embodiment shown in FIG. In the tenth embodiment, the first and second lower flange portions 18b and 28b according to the third embodiment are omitted, and the second lower horizontal wall 26b is thicker than the first lower horizontal wall 16b. The extension portion 28c is extended from the second lower horizontal wall 26b toward the first member 10, and the upper surface of the extension portion 28c is overlapped with the lower surface of the first lower horizontal wall 16 to extend the extension portion 28c. The portion 28c and the first lower lateral wall 16 are fixed to each other by rivets 30 in the vertical direction.

In the present invention, the materials constituting the first and second members are not particularly limited. However, in the embodiment described above, the fact that the first member 10 and the second member 20 are made of an extruded material made of an aluminum alloy means that the first member 10 and the second member 20 are the first member 10 and the second member 20 while reducing the weight of the entire rocker 2. It is possible for each of the two members 10 to have a uniform and integral cross-sectional shape in the longitudinal direction (front-rear direction of the vehicle body). Further, such a rocker 2 includes a step of extruding the first member 10 using an aluminum alloy, a step of extruding the second member 20 using an aluminum alloy, and the first member 10 and the said. It can be easily manufactured by a method including a step of arranging the second members 20 in the horizontal direction and joining them to each other by the rivet 30 or welding.

Of the first member 10 and the second member 20, those constituting the outer member arranged outside in the vehicle body width direction are made of a 6000 series aluminum alloy (Al—Mg—Si based aluminum alloy), and the first member. Of the 1 member 10 and the second member 20, those constituting the inner member arranged inside in the vehicle body width direction are preferably made of a 7000 series aluminum alloy (for example, Al—Zn—Mg based aluminum alloy). .. As described above, the outer member is made of a 6000 series aluminum alloy that is less likely to cause stress corrosion cracking, and the inner member is made of a high-strength 7000 series aluminum alloy, which is high in corrosion resistance and weight reduction. It enables both to ensure strength.

In this case, it is preferable that the lower end of the outer member is located below the lower end of the inner member over the entire longitudinal direction of the outer member. This prevents rainwater or the like from entering the first member 10 made of a 7000 series aluminum alloy through the lower part of the outer member, thereby effectively suppressing the corrosion of the first member 10. To. For example, in each of the rockers 2 shown in FIGS. 2 to 11, when the second member 20 constitutes the outer member, the lower end of the second member 20 is the first member 10 over the entire area in the longitudinal direction thereof. By being located below the lower end, the second member 20 completely covers the lower end of the first member 10 which is an inner member when viewed from the outside in the vehicle body width direction (left side in each drawing). Specifically, in the rockers 2 shown in FIGS. 2 to 6 and 8 to 10, the lower flange portion 28b of the second member 20 has a larger protrusion amount than the lower flange portion 18b of the first member 10. The lower end of the lower flange portion 28b is located below the lower end of the lower flange portion 18b over the entire length of the second member 20 in the longitudinal direction. Further, in the rocker 2 shown in FIG. 7, the lower surface of the second lower horizontal wall 26b of the second member 20 is located below the lower end of the lower flange portion 18b of the first member 10, and is shown in FIG. In the embodiment, the lower surface of the second lower horizontal wall 26b of the second member 20 and the lower surface of the extension portion 28c following the lower surface of the second lower horizontal wall 26b are located below the lower surface of the first lower horizontal wall 16b of the first member 10.

Similarly, it is preferable that the upper end of the outer member is located above the upper end of the inner member over the entire longitudinal direction of the outer member. This makes it possible to prevent rainwater or the like from entering the first member 10 made of the 7000 series aluminum alloy through above the outer member. In each of the rockers 2 shown in FIGS. 2 to 11, when the second member 20 constitutes the outer member, the upper end of the second member 20 extends from the upper end of the first member 10 over the entire area in the longitudinal direction thereof. The second member 20 completely covers the upper end of the first member 10 which is an inner member when viewed from the outside in the vehicle body width direction. Specifically, in the embodiments shown in FIGS. 2 to 4, 7, 7, 10 and 11, the upper flange portion 28a of the second member 20 is larger than the upper flange portion 18a of the first member 10. Due to the protrusion amount, the upper end of the upper flange portion 28a is located above the upper end of the upper flange portion 18a over the entire longitudinal direction of the second member 20. Further, in each of the embodiments shown in FIGS. 5, 6, 8 and 9, the upper surface of the second upper lateral wall 26a of the second member 20 is larger than the upper end of the upper flange portion 18a of the first member 10. It is located on the upper side.

2 Rocker 10 1st member 12 1st outer vertical wall 14 1st inner vertical wall 16 1st lower horizontal wall 16a 1st upper horizontal wall 16b 1st lower horizontal wall 16c 1st inner horizontal wall 18a 1st upper flange portion 18b 1st lower flange Part 20 2nd member 22 2nd outer vertical wall 24 2nd inner vertical wall 26a 2nd upper horizontal wall 26b 2nd lower horizontal wall 26c 2nd inner horizontal wall 26d 2nd upper inner horizontal wall 26e 2nd lower inner horizontal wall 28a 2nd upper flange Part 28b 2nd lower flange part

Claims (14)

A vehicle body lower member that extends in the front-rear direction of the vehicle body and constitutes the lower part of the vehicle body.
The first member extending in the front-rear direction of the vehicle body and
A second member extending in the front-rear direction of the vehicle body, arranged so as to be arranged in a lateral direction parallel to the width direction of the vehicle body, and joined to the first member is provided.
The first member includes a first outer vertical wall that extends in the vertical direction in a cross section that is a cross section seen from the front-rear direction of the vehicle body and is arranged at a position that is separated from the second member in the horizontal direction. They are arranged at intervals in the vertical direction, and each has a plurality of first horizontal walls extending in the horizontal direction from the first outer vertical wall toward the second member in the cross section.
The plurality of first horizontal walls include a first upper horizontal wall connected to an upper end portion of the first outer vertical wall so as to connect the upper end portion of the first outer vertical wall and the second member, and the first outer vertical wall. Including a first lower horizontal wall connected to the lower end of the first outer vertical wall so as to connect the lower end of the wall and the second member.
The second member is arranged with a second outer vertical wall extending in the vertical direction in the cross section and arranged at a position separated from the first member in the horizontal direction at a vertical interval. A plurality of second horizontal walls extending from the second outer vertical wall toward the first member in the cross section, and extending in the vertical direction in the cross section and closer to the first member than the second outer vertical wall. Has a second inner vertical wall, which is placed at the position,
The plurality of second horizontal walls include a second upper horizontal wall connected to the upper end of the second outer vertical wall so as to connect the upper end of the second outer vertical wall and the first member, and the second outer vertical wall. A second lower horizontal wall connected to the lower end of the second outer vertical wall so as to connect the lower end of the wall and the first member, and at least one second inner horizontal wall are included.
The second inner vertical wall is connected to the second upper horizontal wall and the second lower horizontal wall so as to connect the second upper horizontal wall and the second lower horizontal wall in the vertical direction.
The at least one second inner horizontal wall connects the second outer vertical wall and the second inner vertical wall in the horizontal direction in a region between the second upper horizontal wall and the second lower horizontal wall. In the cross section, it extends in the lateral direction to connect to the second outer vertical wall and the second inner vertical wall, and buckling deformation occurs when a certain amount or more of the lateral load is applied to the second member. have a thickness that is capable of,
The first member is a first inner vertical wall extending in the vertical direction in the cross section and arranged at a position closer to the second member than the first outer vertical wall, and is the first upper horizontal wall. Further has a first inner vertical wall connected to the first upper horizontal wall and the first lower horizontal wall so as to connect the first lower horizontal wall in the vertical direction, and the plurality of first horizontal walls are the first. In the region between the upper horizontal wall and the first lower horizontal wall, the first outer vertical wall and the first inner vertical wall extend in the horizontal direction in the cross section so as to connect the first inner vertical wall in the horizontal direction. At least one first one that is connected to the outer vertical wall and the first inner vertical wall and has a thickness capable of buckling deformation when a certain amount or more of the lateral load is applied to the first member. The lower part of the car body, including the inner side wall . A vehicle body lower member of claim 1 Symbol placement, wherein the at least one second inner lateral wall of at least one said inner end portion is an end portion connected to the inner second longitudinal inner wall of the second inner lateral wall of the end portion The portion overlaps the inner end portion of the first lateral wall, which is the end portion of the first lateral wall of any one of the plurality of first lateral walls and is the end portion on the side closer to the second member, in the vertical direction. A lower member of the vehicle body in which the second inner side wall is arranged at a height position. The vehicle body lower member according to claim 2 , wherein the at least one second inner side wall includes a plurality of second inner side walls arranged at intervals in the vertical direction, and at least one of the plurality of second inner side walls. A vehicle body lower member in which the second inner side wall is arranged at a height position where the inner end portion overlaps the inner end part of the first side wall of any one of the plurality of first side walls in the vertical direction. The inner side of the first lateral wall of any one of the plurality of first lateral walls, wherein at least a part of the inner end portion of each of the plurality of second internal lateral walls is the vehicle body lower member according to claim 3. A vehicle body lower member in which each of the plurality of second internal side walls is arranged at a height position that overlaps the end portion in the vertical direction. The vehicle body lower member according to claim 1 , wherein at least a part of the inner end portion of the at least one second inner side wall is any one of the at least one first inner side wall. A lower part of the vehicle body that is placed at a height that overlaps the inner edge in the vertical direction. The vehicle body lower member according to claim 2 , wherein at least a part of the inner end portion of the at least one second inner side wall is the first upper side wall and the first lower side wall. A vehicle body lower member arranged at a height position that overlaps with any of the inner ends in the vertical direction. The second member of the vehicle body according to any one of claims 1 to 6 , wherein the first member constitutes an inner member arranged at a position inside the vehicle body width direction with respect to the second member. A vehicle body lower member, wherein the member constitutes an outer member arranged at a position outside the vehicle body width direction with respect to the first member. The vehicle body lower member according to claim 1 , wherein the first member constitutes an inner member arranged at a position inside the vehicle body width direction with respect to the second member, and the second member is the first member. The vehicle body comprises an outer member arranged at a position outside the vehicle body width direction, and the at least one second inner side wall has a shape of buckling with a load smaller than that of the at least one first inner side wall. Lower member. The second member according to any one of claims 1 to 8 , wherein the first member is an inner end portion of at least one of the first upper side wall and the first lower side wall. It has a flange portion that protrudes outward in the vertical direction from the end portion on the side close to the second member, and is fixed to the second member in a state where the flange portion is in surface contact with the second member in the lateral direction. Lower body member. The vehicle body lower member according to any one of claims 1 to 9 , wherein the first member and the second member are made of an extruded material made of an aluminum alloy. The lower member of the vehicle body according to claim 10 , wherein of the first member and the second member, which constitutes an outer member arranged outside in the width direction of the vehicle body, is made of a 6000 series aluminum alloy, and the first member. Of the 1 member and the 2nd member, the inner member arranged inside in the vehicle body width direction is a vehicle body lower member made of a 7000 series aluminum alloy. The vehicle body lower member according to claim 11 , wherein the lower end of the outer member is located below the lower end of the inner member over the entire longitudinal direction of the outer member. The vehicle body lower member according to claim 11 or 12 , wherein the upper end of the outer member is located above the upper end of the inner member over the entire longitudinal direction of the outer member. The method for manufacturing a vehicle body lower member according to any one of claims 10 to 13 , wherein the first member is extruded and molded using an aluminum alloy, and the second member is formed by using an aluminum alloy. A method for manufacturing a vehicle body lower member, which includes a step of extruding and a step of forming the vehicle body lower member by arranging the first member and the second member in the lateral direction and joining them to each other.

Images