JP7564992B2 - Bumper absorber - Google Patents

Description

The present invention relates to a bumper absorber used as a cushioning material in vehicle bumpers.

Technology relating to a bumper absorber for a vehicle bumper is described in Patent Document 1. As shown in FIG. 11, the bumper absorber 100 described in Patent Document 1 is a cushioning material that is attached to the front of a beam-shaped bumper reinforcement 103 connected to the front of the vehicle body. The bumper absorber 100 is formed into a horizontal column shape with a roughly rectangular cross section from polystyrene foam or the like, and is disposed on the back side of a bumper cover 105. As a result, when a collision load is applied to the front of the vehicle, the bumper cover 105 and the bumper absorber 100 collapse, absorbing the collision load.

However, because the bumper absorber 100 is formed in a solid horizontal column shape using polystyrene foam or the like, when it receives a collision load and is crushed toward the rear of the vehicle, some of the material remains uncrushed. This causes the bumper absorber 100 to lose its ability to absorb collision loads in the later stages of its crushing process. In order to reduce the amount of uncrushed material remaining in the bumper absorber 100, it has been proposed to form the bumper absorber 100 into a box shape using a thin resin plate.

JP 2019-14461 A

However, when the bumper absorber 100 is formed in a box shape extending in the vehicle width direction, the center in the vehicle width direction is relatively easy to crush, whereas both ends in the vehicle width direction, i.e., the ends of the box, are less likely to be crushed because the side panels are structured to support the front panel and the top and bottom panels. Therefore, when the bumper absorber 100 is formed in a box shape extending in the vehicle width direction, there will be residual crushing at both ends in the vehicle width direction.

The present invention was made to solve the above problems, and the problem that the present invention aims to solve is to reduce the amount of remaining crush of the bumper absorber over the entire range in the vehicle width direction.

The above-mentioned problems are solved by the inventions. The first invention is a bumper absorber used as a cushioning material in a vehicle bumper, comprising an absorber main body that collapses when subjected to a collision load, and an absorber mounting portion for mounting the absorber main body to a frame on the vehicle body side, the absorber main body being formed in a box shape by a vertical plate portion constituting a load receiving surface extending in the vehicle width direction, upper plate portions and lower plate portions provided above and below the vertical plate portion, and side plate portions connecting the ends of the vertical plate portion, upper plate portion, and lower plate portion at both ends in the vehicle width direction, the upper plate portion and/or the lower plate portion near both ends of the absorber main body being provided with an opening or a weak portion that extends in the vehicle front-rear direction and crosses the absorber main body, and the weak portion is configured to break when subjected to the collision load.

According to the present invention, the absorber body is box-shaped and has a space formed inside. Therefore, except for both ends of the absorber body, the amount of remaining crushed can be reduced compared to when the absorber body is formed in a solid state from polystyrene foam or the like. In addition, the upper plate and/or the lower plate at both ends of the absorber body are provided with openings or weak parts that extend in the vehicle front-rear direction and cross the absorber body. Therefore, when a collision load is applied to the end of the absorber body, the upper plate and the side plate and/or the lower plate and the side plate are separated at the openings or weak parts and are crushed individually. In other words, since the side plate no longer supports the upper plate and/or the lower plate, both ends of the absorber body are easily crushed. As a result, the amount of remaining crushed can be reduced even at both ends of the absorber body.

According to the first aspect of the present invention, a horizontal bending line extending in the vehicle width direction is formed in the shape of a ridge at the center in the vehicle front-rear direction between the upper plate portion and the lower plate portion of the absorber body, and a vertical bending line is formed on the side plate portion of the absorber body so as to be continuous with the horizontal bending line between the upper plate portion and the lower plate portion. Therefore, due to a collision load, the upper plate portion and the lower plate portion of the absorber body bend at the horizontal bending line and the side plate portion bend at the vertical bending line, so that the absorber body portion is easily crushed in the vehicle front-rear direction.

According to the second aspect of the present invention, the opening or the weak portion of the absorber body is formed along the side plate portion. That is, the opening or the weak portion can be formed immediately adjacent to the ridge line between the side plate portion and the upper plate portion and/or the ridge line between the side plate portion and the lower plate portion, which makes it easier to bend the side plate portion.

According to the third aspect of the present invention, the opening or the weakened portion is formed in the absorber body at a position other than both ends, in the curved portion where the absorber body curves backward. Therefore, the center side and the end side of the curved portion of the absorber body are separated and crushed separately. Therefore, the curved portion is not easily crushed due to the crushing interference between the center side and the end side of the absorber body.

According to the fourth aspect of the present invention, the weakened portion is formed by a plurality of through holes aligned in the vehicle front-rear direction.

According to the fifth aspect of the present invention, the weakened portion is formed by a linear cut extending in the vehicle front-rear direction.

This invention makes it possible to reduce the amount of remaining crushing of the bumper absorber across the entire range in the vehicle width direction.

1 is a side view of a vehicle equipped with a bumper absorber according to a first embodiment of the present invention. 2 is a schematic vertical cross-sectional view of a vehicle bumper including the bumper absorber. FIG. 3 is a plan view of a bumper absorber, a bumper reinforcement, and the like of the vehicle bumper (a plan view taken along an arrow III in FIG. 2 ). FIG. FIG. 2 is a perspective view of the bumper absorber and the bumper reinforcement as viewed from the right front of the vehicle. FIG. 4 is an enlarged plan view of a right end portion of the bumper absorber. FIG. 11 is an enlarged plan view of a right end portion of the bumper absorber according to the first modified example. FIG. 11 is an enlarged plan view of a right end portion of a bumper absorber according to a second modified example. FIG. 13 is an enlarged plan view of a right end portion of a bumper absorber according to a third modified example. 1 is a deformation image (schematic diagram) showing how a right end portion of a bumper absorber is crushed when subjected to a collision load. 4 is a graph showing how a bumper absorber is crushed when subjected to a collision load. FIG. 1 is a vertical cross-sectional view of a conventional vehicle bumper.

[Embodiment 1]
A bumper absorber according to a first embodiment of the present invention will be described below with reference to Figures 1 to 10. The bumper absorber according to this embodiment is a bumper absorber 30 used as a cushioning material for a front bumper 20 of a vehicle 10. Here, the front, rear, left, right, and top and bottom shown in the figures correspond to the front, rear, left, right, and top and bottom of the vehicle 10 equipped with the front bumper 20.

<Overview of the front structure of the vehicle 10>
As shown in Fig. 3, a pair of front side members 14 extending in the longitudinal direction of the vehicle are provided on both the left and right sides of an engine room E at the front of the vehicle body of the vehicle 10. Crash boxes 16 are attached approximately coaxially to the front end positions of the left and right front side members 14. Left and right ends of a bumper reinforcement 40 constituting a front bumper 20 are connected to the left and right crash boxes 16. The crash boxes 16 are configured to absorb a collision load by being crushed between the front bumper 20 and the front side members 14 in the event of a frontal collision of the vehicle 10.

<Configuration of front bumper 20>
As shown in Fig. 2, the front bumper 20 includes the above-mentioned bumper reinforcement 40, the bumper absorber 30, the lower absorber 35, the bumper cover 21, and the bumper grill 23. As shown in Fig. 3, the bumper reinforcement 40 is a beam-shaped member extending in the vehicle width direction, and both left and right ends of the bumper reinforcement 40 are connected to the left and right crash boxes 16 as described above.

As shown in Figs. 2 and 3, the bumper absorber 30 is attached to the front surface 42 of the bumper reinforcement 40. The bumper absorber 30 is a cushioning material that extends in the vehicle width direction along the bumper reinforcement 40, and is formed, for example, in a box shape with an open rear side from a thin resin plate. As shown in Figs. 1 and 2, the bumper cover 21 is a resin member that constitutes the external design of the front bumper 20, and is configured to cover the bumper absorber 30, the lower absorber 35, and the bumper reinforcement 40. The center of the bumper cover 21 in the height direction is supported from the rear side by the front surface of the bumper absorber 30, and the lower end of the bumper cover 21 is supported by the lower absorber 35. Furthermore, a bumper grille 23 that functions as an air intake and is a decorative member is attached to the center position of the bumper cover 21.

<Configuration of bumper absorber 30>
2 to 4, the bumper absorber 30 is an injection-molded resin product, and includes an absorber main body 320 that collapses when subjected to a collision load, and an absorber attachment portion 340 for attaching the absorber main body 320 to the bumper reinforcement 40. The bumper absorber 30 is molded from, for example, polypropylene (PP) resin.

<Regarding absorber attachment portion 340>
2 to 4, the absorber mounting portion 340 is formed in a cover shape so as to cover the front surface 42, the upper surface 43, and the lower surface 44 of the bumper reinforcement 40. That is, as shown in Fig. 2, the absorber mounting portion 340 includes an upper front plate portion 341 and a lower front plate portion 342 which respectively cover the upper side and the lower side of the front surface 42 of the bumper reinforcement 40, and an upper plate portion 343 and a lower plate portion 344 which respectively cover the upper surface 43 and the lower surface 44 of the bumper reinforcement 40. Also, as shown in Fig. 4, the absorber mounting portion 340 includes side plate portions 345 which cover the left and right end surfaces (numbers omitted) of the bumper reinforcement 40.

Connecting means (not shown), such as clips, are provided on the backside of the upper front plate 341 and the lower front plate 342 of the absorber mounting portion 340. As shown in FIG. 4, a connecting hole 42h is formed on the front surface 42 of the bumper reinforcement 40 at a position corresponding to the clip of the absorber mounting portion 340. As a result, the clip of the absorber mounting portion 340 is inserted into the connecting hole 42h of the bumper reinforcement 40, thereby fixing the absorber mounting portion 340 to the bumper reinforcement 40.

<Regarding the absorber main body 320>
As shown in FIG. 2 and other figures, the absorber body 320 is formed so as to protrude forward from the absorber mounting portion 340. That is, the absorber body 320 is formed in a box shape with a cross section that is substantially a horizontal U-shape and an open rear side. As shown in FIG. 2 and FIG. 4, the absorber body 320 includes a front vertical plate 321 that constitutes a load receiving surface extending in the vehicle width direction, and an upper plate 323 and a lower plate 324 that are provided above and below the front vertical plate 321. As shown in FIG. 4, the absorber body 320 includes side plate portions 325 that connect the ends of the front vertical plate 321, the upper plate 323, and the lower plate 324 to each other at both ends in the vehicle width direction (only the right end is shown in FIG. 4). As a result, the absorber body 320 is formed in a box shape with an open rear side. The side plate portion 325 of the absorber main body portion 320 is integrated with the side plate portion 345 of the absorber attachment portion 340 .

As shown in FIG. 3, the absorber body 320 is gently curved such that the central portion other than both ends (left end and right end) in the vehicle width direction is convex toward the front. The right and left ends of the absorber body 320 are curved backward at the position of the curved portion W with respect to the central portion, as shown in FIG. 3 and FIG. 4. In addition, horizontal bending lines 323x, 324x extending in the vehicle width direction parallel to the front vertical plate portion 321 are formed in the center of the upper plate portion 323 and the lower plate portion 324 of the absorber body 320 in the vehicle front-rear direction (width direction) in the ridge line shape. Furthermore, in the side plate portion 325 of the absorber body 320, as shown in FIG. 4, a vertical bending line 325y is formed so as to cross the side plate portion 325 from top to bottom at a position continuous with the horizontal bending lines 323x, 324x of the upper plate portion 323 and the lower plate portion 324.

Furthermore, as shown in Figs. 4 and 5, the upper plate 323 and the lower plate 324 at the right end (left end) of the absorber body 320 are provided with an opening 50 that extends in the vehicle front-rear direction near the side plate 325 and crosses the upper plate 323 and the lower plate 324. Note that the left end of the absorber body 320 is not shown in Figs. 4 and 5. The opening 50 is formed in a slit shape that is wide at the front and narrow at the rear, and is formed from the front end to the rear end of the upper plate 323 and the lower plate 324. As a result, the bending horizontal lines 323x, 324x formed in the upper plate 323 and the lower plate 324 are cut at the position of the opening 50.

<Operation of the bumper absorber 30>
When a collision load is applied to the right end (left end) of the front bumper 20, the right end (left end) of the absorber main body 320 of the bumper absorber 30 sandwiched between the bumper cover 21 and the bumper reinforcement 40 will be crushed toward the rear of the vehicle as shown in Fig. 2. Since an opening 50 is formed in the right end (left end) of the absorber main body 320 near the side plate 325 as shown in Fig. 5, the opening 50 separates the upper plate 323 and the lower plate 324 from the portions close to the side plate 325 and the portions close to the center. As a result, the side plate 325 of the absorber main body 320 and the portions close to the center of the upper plate 323 and the lower plate 324 will be crushed independently and individually.

That is, as shown in FIG. 9, the side plate portion 325 of the absorber main body portion 320 is crushed so as to protrude outward in the vehicle width direction at the position of the vertical bending line 325y. The upper plate portion 323 of the absorber main body portion 320 is crushed so as to protrude upward at the position of the horizontal bending line 323x. Furthermore, the lower plate portion 324 of the absorber main body portion 320 is crushed so as to protrude downward at the position of the horizontal bending line 324x. In this way, because the side plate portion 325 of the absorber main body portion 320 does not support the upper plate portion 323 and the lower plate portion 324, the right end portion (left end portion) of the absorber main body portion 320 is easily crushed, and only a small portion remains uncrushed.

Characteristic I (solid line) in FIG. 10 is a graph showing the relationship between the collision load F applied to the absorber body 320 according to this embodiment and the collapse stroke. Characteristic II (dotted line) is a graph showing the relationship between the collision load F applied to the absorber body 320 when the opening 50 is not provided and the collapse stroke. As is clear from FIG. 10, by providing the opening 50 at the end of the absorber body 320, the end of the absorber body 320 becomes easier to collapse, and less remains crushed when the shock load F is applied. Note that in the center of the absorber body 320 in the vehicle width direction, the upper plate 323 and the lower plate 324 are separated from the side plate 325, so they are not affected by the side plate 325 and are easier to collapse.

<Correspondence between terms used in this embodiment and terms used in the present invention>
The front bumper 20 in this embodiment corresponds to the vehicle bumper in the present invention, and the bumper reinforcement 40 corresponds to the frame on the vehicle body side in the present invention. Also, the front vertical plate portion 321 of the absorber main body portion 320 in this embodiment corresponds to the vertical plate portion constituting the load receiving surface in the present invention.

Advantages of the bumper absorber 30 according to this embodiment
According to the bumper absorber 30 of this embodiment, the absorber body 320 is box-shaped and has a space formed inside. Therefore, the amount of remaining crush can be reduced at the portions other than both ends of the absorber body 320 compared to the case where the absorber body 320 is formed in a solid state with polystyrene foam or the like. In addition, the upper plate portion 323 and the lower plate portion 324 at both ends of the absorber body 320 are provided with openings 50 that extend in the vehicle front-rear direction and cross the absorber body 320. Therefore, when a collision load is applied to the end of the absorber body 320, the upper plate portion 323 and the side plate portion 325, and the lower plate portion 324 and the side plate portion 325 are separated at the position of the openings 50 and are crushed individually. In other words, the side plate portion 325 no longer supports the upper plate portion 323 and the lower plate portion 324, so that both ends of the absorber body 320 are easily crushed. As a result, the amount of residual crushing at both ends of the absorber body 320 can be reduced.

[Example of change]
The present invention is not limited to the above embodiment, and modifications are possible within the scope of the present invention. For example, in the present embodiment, as shown in Fig. 5, an example is shown in which slit-shaped openings 50, which are wide at the front and narrow at the rear, are provided in the upper plate 323 and the lower plate 324 of the absorber body 320 in positions near the side plate 325. However, as shown in Fig. 6, slit-shaped openings 51 of equal width can also be provided in the upper plate 323 and the lower plate 324 of the absorber body 320 along the side plate 325. In this way, the openings 51 can be formed immediately adjacent to the ridge between the side plate 325 and the upper plate 323 and the ridge between the side plate 325 and the lower plate 324, making it easier to bend the side plate 325.

It is also possible to provide a slit-shaped opening 52 extending forward and backward at the position of the curved portion W between the upper plate portion 323 and the lower plate portion 324 of the absorber main body portion 320. This allows the upper plate portion 323 and the lower plate portion 324 on the center side and the upper plate portion 323 and the lower plate portion 324 on the end side to be separated and crushed separately with respect to the curved portion W of the absorber main body portion 320. Therefore, there is no interference between the crushing of the center side and the end side of the absorber main body portion 320, and the curved portion W is not easily crushed.

In addition, instead of providing slit-shaped openings 50, 51, 52 in the upper plate portion 323 and the lower plate portion 324 as shown in Figures 5 and 6, it is also possible to provide weak parts 53, 54 in which multiple through holes are arranged in a front-to-back manner as shown in Figure 7. The weak parts 53, 54 are structured so that they can be broken linearly in the front-to-back direction when subjected to a collision load. It is also possible to provide weak parts 55, 56 consisting of linear cuts as shown in Figure 8.

In addition, in this embodiment, an example is shown in which the openings 50, 51, 52 or the weak parts 53, 54, 55, 56 are provided on both the upper plate part 323 and the lower plate part 324 of the absorber main body part 320. However, it is also possible to provide the openings 50, 51, 52 or the weak parts 53, 54, 55, 56 on either the upper plate part 323 or the lower plate part 324. In addition, in this embodiment, the front bumper 20 is shown as an example of a vehicle bumper, but the bumper absorber 30 according to the present invention can also be applied to a rear bumper.

20. Front bumper (vehicle bumper)
30: Bumper absorber 40: Bumper reinforcement (frame on the vehicle body side)
50: Opening 51: Opening 52: Opening 53: Weak portion 54: Weak portion 55: Weak portion 56: Weak portion 320: Absorber main body 321: Front vertical plate portion (vertical plate portion constituting the load receiving surface)
323: Upper plate portion 323x: Horizontal bending line 324: Lower plate portion 324x: Horizontal bending line 325: Side plate portion 325y: Vertical bending line 340: Absorber attachment portion W: Curved portion

Claims (5)

A bumper absorber used as a cushioning material in a vehicle bumper,
an absorber main body that is crushed by a collision load;
an absorber mounting portion for mounting the absorber main body portion to a frame on a vehicle body side;
Equipped with
the absorber main body is formed in a box shape and includes a vertical plate portion constituting a load receiving surface extending in the vehicle width direction, an upper plate portion and a lower plate portion provided above and below the vertical plate portion, and side plate portions connecting ends of the vertical plate portion, the upper plate portion, and the lower plate portion to each other at both ends in the vehicle width direction,
an opening or a fragile portion is provided in the upper plate portion and/or the lower plate portion near both ends of the absorber main body portion, the opening or fragile portion being formed to extend in the vehicle front-rear direction and cross the absorber main body portion,
The fragile portion is configured to break when subjected to the collision load,
a horizontal bend line extending in a vehicle width direction is formed in a ridge shape at a central portion in a vehicle front-rear direction between the upper plate portion and the lower plate portion of the absorber main body,
A bumper absorber , in which a vertical bending line is formed on the side plate portion of the absorber body portion so as to be continuous with the horizontal bending line between the upper plate portion and the lower plate portion . 2. The bumper absorber according to claim 1,
The opening or the weakened portion of the absorber body is formed along the side plate portion . A bumper absorber according to claim 1 or 2,
A bumper absorber in which the opening or weak portion is formed in the absorber body at a position other than the two end portions, at a curved portion where the absorber body curves rearward . A bumper absorber according to any one of claims 1 to 3,
The fragile portion is a bumper absorber formed by a plurality of through holes aligned in the front-rear direction of the vehicle . A bumper absorber according to any one of claims 1 to 3 ,
The fragile portion is a linear cut extending in the front-rear direction of the vehicle .

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