JP6809425B2 - Vehicle crash box - Google Patents

Description

The present invention relates to a vehicle crash box that absorbs an impact at the time of a vehicle collision.

For example, in Patent Document 1, a crash box is provided between a bumper reinforcement (hereinafter, appropriately referred to as a bumper R / F) constituting a vehicle skeleton member and a side member.

For example, as illustrated in FIG. 6, the crash box 100 is a housing member, and the side walls 102A and 102B of the crash box 100 extending in the front-rear direction of the vehicle have a crash that is a starting point of crush deformation at the time of a collision. The bead 103 is formed.

When fixing the crash box 100 to the bumper R / F 104, the opposing walls 106 and 108 of the crash box 100 and the bumper R / F 104 are bolted together.

For example, as illustrated in FIG. 6, when a collision load is transmitted from the bumper R / F 104, the side wall of the crash box 100 sandwiched between the bumper R / F 104 and the side members (not shown) along the vehicle front-rear direction. A compressive load is applied to the 102A and 102B, which causes the side walls 102A and 102B to be crushed and deformed starting from the crash bead 103. For example, the side walls 102A and 102B are crushed and deformed in a bellows shape. As a result, the impact at the time of collision is absorbed.

JP-A-2017-52384

By the way, the contact surfaces of the bumper R / F and the crash box may move relative to each other and rub against each other due to vehicle vibration or the like, resulting in abnormal noise. In order to suppress the abnormal noise, it is conceivable to reduce the contact area between the two. For example, as illustrated in FIG. 7, a part of the facing wall 106 of the crash box 100 may be projected outward to form a protruding portion 109, and the top 110 of the protruding portion 109 may be fastened to the bumper R / F 104. Conceivable.

However, when the projecting portion 109 is provided on the facing wall 106, the crushing deformation mode (crushing method) of the crash box 100 may become unstable. As shown in FIG. 7, slope portions 114A and 114B connected to the flat plate portion 112 are formed on the protruding portion 109 from both ends of the top portion 110. Depending on the processing status of the crash box 100, the slope portions 114A and 114B and the side walls 102A and 102B of the crash box 100 may be offset in the vehicle width direction. In the example of FIG. 7, the slope portions 114A and 114B are arranged so as to be inserted between the side walls 102A and 102B.

FIG. 8 shows an example when the collision load is input to the bumper R / F104. The load input to the bumper R / F 104 is first transmitted to the protruding portion 109 at the tip of the crash box 100, and after the protruding portion 109 is crushed to the rear of the vehicle, the load is transmitted to the rear members such as the side walls 102A and 102B. To.

At this time, in the process of crushing the protruding portion 109 to the rear of the vehicle, a bending load toward the center line C is applied to the side walls 102A and 102B as shown in the figure. By applying a bending load to the side walls 102A and 102B instead of the conventional compressive load, the side walls 102A and 102B are likely to be bent and buckled, and the side walls 102A and 102B are deformed with a load smaller than the conventional or designed value. There is a risk. Therefore, an object of the present invention is to enable stable crush deformation in a crash box provided with a protruding portion as a contact means for the bumper R / F.

The present invention relates to a vehicle crash box. The crash box includes a main body and an facing wall. The main body is formed in a square tube shape by a plurality of side walls extending in the front-rear direction of the vehicle, and a plurality of partition walls extending in the front-rear direction of the vehicle are formed inside the main body portion. The facing wall is arranged at the front end or the rear end of the main body and faces the bumper R / F. The facing wall includes a flat plate portion and a protruding portion projecting from the flat plate portion to the bumper R / F side. The protruding portion includes a contact portion that comes into contact with the bumper R / F and a slope portion that connects the contact portion and the flat plate portion. The abutting portion is provided between the side wall of the main body and the partition wall adjacent thereto, or between the partition walls adjacent to each other. At least a part of the ridge line formed by the slope portion and the flat plate portion overlaps on the extension line of the side wall and the partition wall adjacent thereto, or the partition wall adjacent thereto along the front-rear direction of the vehicle.

According to the present invention, the compressive load is directly transmitted from the slope portion to the side wall and the partition wall, and the input of the bending load to the side wall and the partition wall is avoided in the transmission process. As a result, the side wall and the partition wall can be crushed and deformed with a load as designed, and stable crushing deformation is possible.

It is an exploded perspective view which illustrates each member constituting the crash box for a vehicle which concerns on this embodiment. It is a figure when the crash box for a vehicle which concerns on this embodiment is viewed from the front. It is a cross-sectional view of AA plan view which illustrates the crash box for a vehicle which concerns on this embodiment. It is a cross-sectional view of AA plan view which illustrates the state at the time of a collision load input. It is an exploded perspective view which shows another example of the crash box for a vehicle which concerns on this embodiment. It is a top view sectional view which illustrates the conventional crash box for a vehicle. It is a top view sectional view which shows the example which provided the protruding part in the conventional crash box for a vehicle. It is a top view sectional view explaining the state at the time of the collision load input when the protrusion part is provided in the conventional crash box for a vehicle.

FIG. 1 illustrates each member constituting the vehicle crash box 10 according to the present embodiment. Further, FIG. 2 illustrates a front view of the crash box 10, and FIG. 3 illustrates a cross-sectional view taken along the line AA in FIG. 1 when the crash box 10 is assembled to the bumper R / F16.

In FIGS. 1 to 5, the vehicle front-rear direction is indicated by the axis represented by the symbol FR, the vehicle width direction is indicated by the axis represented by the symbol LW, and the vertical direction is indicated by the axis represented by the symbol UP. The symbol FR is an abbreviation for Front, and the front-rear axis FR has the front of the vehicle in the positive direction. The symbol LW is an abbreviation for Left Width, and the width direction axis LW has the left width direction as the positive direction. Further, the height axis UP has an upward direction as a positive direction.

As shown in FIG. 1, these FR axes, LW axes, and UP axes are orthogonal to each other. Hereinafter, when the vehicle crash box according to the present embodiment is described, it will be appropriately described with reference to these three axes. For example, the "front end" refers to the end of any member on the positive direction of the FR axis, and the "rear end" refers to the end of any member on the negative direction of the FR axis. "Inside the width" refers to the inside of the vehicle relative to the width of the vehicle along the LW axis, and "outside the width" refers to the outside of the vehicle relative to the outside of the width of the vehicle along the LW axis. Further, "upper side" relatively refers to the positive direction side of the UP axis, and "lower side" relatively refers to the negative direction side of the UP axis.

The vehicle crash box 10 according to the present embodiment includes a main body portion 12 and an facing wall 14. The vehicle crash box 10 is provided between the bumper R / F16 (see FIG. 3) and the side member (not shown). The crash box 10 may be provided between the front bumper R / F and the front side member, or may be provided between the rear bumper R / F and the rear side member.

As will be described later, when the crash box 10 is provided between the front bumper R / F and the front side member, the facing wall 14 is arranged at the front end of the main body 12. When the crash box 10 is provided between the rear bumper R / F and the rear side member, the facing wall 14 is arranged at the rear end of the main body 12.

The main body 12 is a square tubular member formed by a plurality of side walls 18A to 18D extending in the front-rear direction of the vehicle. Further, a plurality of partition walls 20A to 20C extending in the front-rear direction of the vehicle are formed inside the square cylinder. The main body 12 is formed by extruding a metal material such as aluminum.

The side walls 18A to 18D are formed, for example, having equal lengths in the vehicle front-rear direction. For example, the side walls 18A to 18C (upper side wall, right side wall, and left side wall) are formed in a flat plate shape. Further, in order to maintain consistency with peripheral parts, for example, the side wall 18D (lower side wall) is bent upward at an intermediate portion in the width direction. Further, the side walls 18B and 18C (right side wall and left side wall) facing each other are extended so as to be parallel to each other in the vertical direction.

Further, on the side walls 18A to 18D, a crash bead 23 which is a starting point of crush deformation at the time of a collision is formed. The crash bead 23 is formed in a groove shape extending along the vehicle width direction and the vertical direction, for example. The crush bead 23 is formed, for example, by press working. The crush bead 23 may not be provided in the region (indicated by the broken line) through which the relatively high-strength partition walls 20A to 20C pass.

The partition walls 20A to 20C divide the inside of the main body 12 into a plurality of small rooms. The partition walls 20A and 20B are extended in parallel with, for example, the side walls 18B and 18C (right side wall and left side wall). Further, the side wall 18B and the partition wall 20A, the partition wall 20A and the partition wall 20B, and the partition wall 20B and the side wall 18C are formed at equal intervals (pitch), for example.

The partition walls 20A and 20B extend from the side wall 18A (upper side wall) to the side wall 18D (lower side wall), respectively. Further, the partition walls 20A and 20B are extended from the front end to the rear end of the side wall 18A and the side wall 18D, respectively.

Similarly, the partition wall 20C extends parallel to, for example, the side wall 18A (upper side wall). The partition wall 20C extends from the side wall 18B (right side wall) to the side wall 18C (left side wall). Further, the partition wall 20C extends from the front end to the rear end of the side walls 18B and 18C.

The facing wall 14 is a wall member arranged at the front end or the rear end of the main body portion 12 and facing the bumper R / F 16 (see FIG. 3). For example, when the crash box 10 is a front crash box provided between the front bumper R / F and the front side member, the facing wall 14 is arranged at the front end of the main body 12 facing the front bumper R / F. Similarly, when the crash box 10 is a rear crash box provided between the rear bumper R / F and the rear side member, the facing wall 14 is arranged at the rear end of the main body 12 facing the rear bumper R / F. In addition, in FIGS. 1 to 5, an example in which the crash box 10 is used as a front crash box is shown.

For example, the area of the UP-LW surface of the facing wall 14 is formed so as to be one size larger than the same area (opening area) of the main body portion 12. The facing wall 14 is joined to the main body 12 so as to cover the end opening of the main body 12. For example, the facing wall 14 and the main body 12 are butted against each other and joined by fillet welding, spot welding, or the like. As will be described later, in this joining, the protruding portion 22 of the facing wall, the side walls 18A to 18D, and the partition walls 20A to 20C are aligned.

The facing wall 14 includes a flat plate portion 24 and protrusions 22A to 22C. The flat plate portion 24 is a portion serving as a reference surface of the facing wall 14, and has a function of a lid covering the end opening of the main body portion 12.

The protruding portions 22A to 22C are respectively projected from the flat plate portion 24 to the bumper R / F16 side by press working or the like. The protruding portions 22A to 22C include contact portions 26A to 26C and slope portions 28A to 28C. The contact portions 26A to 26C are the tip portions of the protruding portions 22A to 22C, and are formed in parallel with the facing portion 30 so as to be able to contact the facing portion 30 (see FIG. 3) of the bumper R / F16. The contact portions 26A to 26C are formed, for example, in a circular shape.

Further, a bolt hole 32 is formed at the center of the contact portions 26A to 26C. Further, the nut 35 is joined to the back surface of the contact portions 26A to 26C, that is, the surface on the main body portion 12 side so as to be concentric with the bolt hole 32. As illustrated in FIG. 3, the bolt 36 is screwed into the bolt hole 32 and the nut 35 via the insertion hole 37 opened on the front surface of the bumper R / F16, so that the facing portion 30 and the contact portion 26A Is concluded. That is, the crash box 10 is fastened to the bumper R / F16.

The slope portions 28A to 28C are inclined portions connecting the contact portions 26A to 26C and the flat plate portion 24. When the abutting portions 26A to 26C are formed in a circular shape, the slope portions 28A to 28C extend concentrically from the circular abutting portions 26A to 26C and their skirts are connected to the flat plate portion 24.

FIG. 2 exemplifies the positional relationship between the front view of the main body 12 in the crash box 10 and the corresponding protrusions 22A to 22C of the facing wall 14. In order to avoid overlapping lines, the protruding portions 22A to 22C are indicated by broken lines. Further, the flat plate portion 24 is not shown.

As shown in FIG. 2, the contact portion 26A is arranged between the side wall 18C of the main body portion 12 and the partition wall 20B. The contact portion 26B is arranged between the side wall 18B and the partition wall 20A. The contact portion 26C is arranged between the adjacent partition walls 20A and 20B.

In addition, the slope portions 28A to 28C extending from the contact portions 26A to 26C have their roots, that is, when the connecting portion with the flat plate portion 24 is viewed from the side walls 18A to 18D and the partition walls 20A to 20C in the vehicle front-rear direction. Arranged so that they partially overlap. That is, a ridge line 34 is formed at the base of the slope portions 28A to 28C by the slope portions 28A to 28C and the flat plate portion 24. In the crash box 10 according to the present embodiment, as illustrated in FIGS. 2 and 3, at least a part of the ridge line 34 is an extension line of the side walls 18A to 18D and the partition walls 20A to 20C along the front-rear direction (FIG. The main body 12 and the facing wall 14 are formed so as to overlap with each other (indicated by a broken line in 3).

Specifically, a part of the ridge line 34 of the slope portion 28A overlaps the extension line of the side wall 18C and the partition walls 20B and 20C. A part of the ridge line 34 of the slope portion 28B overlaps the side wall 18B and the extension lines of the partition walls 20A and 20C. Further, a part of the ridge line 34 of the slope portion 28C overlaps with the extension lines of the side wall 18A and the partition walls 20A and 20B.

FIG. 4 illustrates the behavior of the crash box 10 at the time of a forward collision. Although only the behavior of the protruding portion 22A is illustrated in FIG. 4, the other protruding portions 22B and 22C also have the same behavior. At the time of a forward collision, a collision load is input from the bumper R / F 16 to the crash box 10. This collision load acts mainly in the front-rear direction of the vehicle. At this time, in the crash box 10, first, a load is input so that the protruding portion 22A in contact with the bumper R / F 16 is crushed to the rear of the vehicle. Here, since the slope portion 28A of the protruding portion 22A is sandwiched between the bumper R / F16, the side wall 18C, and the partition wall 20B in the front-rear direction of the vehicle, it receives a compressive load and bends in the width direction.

Further, the compressive stress of the slope portion 28A is transmitted to the side wall 18C and the partition wall 20B. Here, as described above, since the root (ridge line) of the slope portion 28A, the side wall 18C, and the partition wall 20B are arranged linearly in the vehicle front-rear direction, the compressive stress of the slope portion 28A is the side wall 18C and the partition wall. It is transmitted directly to 20B. In this way, when the load is transmitted from the slope portion 28A to the side wall 18C and the partition wall 20B, the input of the bending load to the side wall 18C and the partition wall 20B is avoided, so that the side wall 18C and the partition wall 20B are as designed ( It can be crushed and deformed (stable).

<Another example of this embodiment>
FIG. 5 shows another example (modification example) of the crash box 10 according to the present embodiment. The difference from the embodiment of FIGS. 1 to 4 lies in the shape of the protrusions 22A to 22C formed on the facing wall 14. The abutting portions 26A to 26C are formed along a rectangular shape partitioned by the side walls 18A to 18D and the partition walls 20A to 20C.

Further, in the slope portions 28A to 28C extending from the contact portions 26A to 26C, the ridge line 34 at the base (base) thereof extends along the entire circumference along the side walls 18A to 18D and the partition walls 20A to 20C along the front of the vehicle (FR axis). Overlap on an extension (along). Specifically, the ridge line 34 of the slope portion 28A overlaps the extension lines of the side walls 18C and 18D and the partition walls 20B and 20C over the entire circumference. The ridge line 34 of the slope portion 28B overlaps the side walls 18B and 18D and the extension lines of the partition walls 20A and 20C over the entire circumference. Further, the ridge line 34 of the slope portion 28C overlaps the side wall 18A and the extension lines of the partition walls 20A to 20C over the entire circumference.

In this way, the ridge lines 34 of the slope portions 28A to 28C overlap on the extension lines of the side walls 18A to 18D and the partition walls 20A to 20C along the front of the vehicle (along the FR axis) over the entire circumference. The load is reliably transmitted from the slope portions 28A to 28C to the side walls 18A to 18D and the partition walls 20A to 20C.

10 Crash box for vehicles, 12 Main body, 14 Opposing wall, 18 Side wall, 20 Partition wall, 22 Protruding part, 23 Crash bead, 24 Flat plate part, 26 Abutment part, 28 Slope part, 30 Bumper R / F facing part , 32 bolt holes, 34 ridges, 35 nuts, 36 bolts.

Claims (1)

The main body, which is formed in a square tube shape by a plurality of side walls extending in the front-rear direction of the vehicle, and a plurality of partition walls extending in the front-rear direction of the vehicle are formed therein.
An opposing wall that is arranged at the front end or the rear end of the main body and faces the bumper R / F.
It is a crash box for vehicles equipped with
The facing wall includes a flat plate portion separated from the bumper R / F and a projecting portion protruding from the flat plate portion toward the bumper R / F.
The protruding portion includes a contact portion provided at the protruding end of the protruding portion and having a contact surface that contacts the bumper R / F, and a slope portion that connects the contact portion and the flat plate portion.
The contact portion is provided between the side wall of the main body portion and the partition wall adjacent thereto, or between the partition walls adjacent to each other.
At least a part of the ridge line formed by the slope portion and the flat plate portion overlaps on the extension line of the side wall and the partition wall adjacent thereto, or the partition wall adjacent thereto along the vehicle front-rear direction.
Crash box for vehicles.