JP2015189406A - Bumper device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively absorb collision energy by a common crash box even if a vehicle body is shared between a vehicle which is low in a ground height and a vehicle which is high in the ground height.SOLUTION: A front end side of a flange part 30b of an upper stay member 30 is made to ride on an upper face of a bumper beam, a protrusion 30a is formed while protruding from the upper face of the bumper beam, flange parts 31c, 31d of a lower stay member 31 are joined to a side face and a lower face of the bumper beam, ridge lines which are formed of flange parts 30b, 31b being vertical joining faces between the upper stay member 30 and the lower stay member 31 extend in parallel with an axial core of a side member, and a box structure is attached so as to be inclined downwardly between the bumper beam and the side member. By this constitution, even in vehicles which are different in vehicle heights, a crush box can be crushed in order from the front without escaping to a vertical direction, and collision energy can be effectively absorbed.

Description

  The present invention relates to a vehicle bumper device that absorbs collision energy by interposing a crash box between a bumper beam and a side member.

  In general, a bumper device for a vehicle is configured by connecting a bumper beam (reinhose) arranged in the vehicle width direction inside a bumper exterior to a vehicle body frame via a pair of left and right crash boxes, and the impact at the time of a vehicle collision. The crush box is plastically deformed by the load and absorbs the collision energy.

  In this case, the mounting height of the bumper beam varies depending on the type of vehicle, and the mounting height of the bumper beam and the height of the side member may be offset. For this reason, the crash box and the bumper beam are mounted with an offset, and the bumper beam may be twisted at the time of collision, or an eccentric load may be input to the crash box, and the collision energy may not be sufficiently absorbed. .

  For this reason, for example, in Patent Document 1, when the heights of both the bumper beam and the side member are offset, a crash box inclined in the vertical direction is attached between the bumper beam and the side member. Thus, a technique for ensuring the energy absorption performance of the crash box is disclosed.

JP 2012-30624 A

  Compared to the conventional crash box as disclosed in Patent Document 1, the vehicle body is made common to low-height vehicles with low ground height and high-height vehicles with high ground height to reduce costs. When trying to do so, since the difference in relative height between the bumper beam and the side member is constant, the crash box is also mounted between the bumper beam and the side member at a fixed position.

  For this reason, even if the crash load input position disclosed in Patent Document 1 is applied to a vehicle with a low vehicle height and a vehicle with a high vehicle height, the input position of the collision load increases and decreases. The force acts and the crash box escapes in the vertical direction and falls easily. As a result, the crush box is prevented from collapsing in the axial direction sequentially from the front, and it becomes difficult to effectively absorb the collision energy.

  The present invention has been made in view of the above circumstances, and even when a vehicle body is shared by a vehicle having a low ground clearance and a vehicle having a high ground clearance, collision energy can be effectively absorbed by a common crash box. An object of the present invention is to provide a bumper device for a vehicle.

  A bumper device for a vehicle according to the present invention is a bumper device that absorbs collision energy by interposing a crash box between a bumper beam and a side member of the vehicle. Joined and formed as a cylindrical box structure inclined from the bumper beam side toward the side member side, and one split member of the box structure is arranged to protrude vertically from the bumper beam, The ridge line in the front-rear direction formed by the joint surface between the upper split member and the lower split member is arranged so as to be parallel to the axial direction of the side member.

  According to the present invention, even when a vehicle body is shared by a vehicle having a low ground clearance and a vehicle having a high ground clearance, collision energy can be effectively absorbed by the common crash box.

Explanatory drawing which shows the structure of the bumper apparatus of a vehicle Top view showing the crash box between the bumper beam and the side member A perspective view of the crash box as seen from inside the engine chamber Crash box perspective view Crash box side view AA line sectional view of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a bumper device for a vehicle such as an automobile. In the present embodiment, reference numeral 1 denotes a front bumper device disposed at the front of the vehicle. The bumper device 1 is disposed between a bumper beam 2 extending in the vehicle width direction and a pair of side members 10 that form a skeleton at the bottom of the vehicle body and extend in the vehicle front-rear direction. A pair of crash boxes 3 is provided as a main component.

  The bumper beam 2 is formed of, for example, a hollow metal material having a rectangular cross section, and extends linearly in the vehicle width direction, and a predetermined angle along the corners of the front part of the vehicle body on both sides of the linear portion 2a. And an offset portion 2b bent at the end. The front end side of the crash box 3 is fixed inside the offset portion 2 b, and the rear end side of the crash box 3 is connected to the front end side of the side member 10.

  The crash box 3 absorbs impact energy at the time of a light collision by performing plastic buckling deformation and crushing in the axial direction by an impact load input via the bumper beam 2 at the time of collision. As shown in FIG. 6, it is formed as a cylindrical box structure formed by, for example, welding two split members formed by pressing a thin steel plate. This box structure is formed by vertically joining a pair of upper stay members 30 and a lower stay member 31 as a pair of split members having a substantially hat-shaped cross section perpendicular to the longitudinal direction.

  In addition, a rectangular plate-like plate member 32 having a plane perpendicular to the longitudinal direction is joined to the rear end side of the box structure formed by the upper stay member 30 and the lower stay member 31 by abutting welding or the like. A part of the front side of the upper stay member 30 is overlapped on the upper surface of the bumper beam 2 and joined by spot welding or the like, and the rear plate member 32 is bolted to the plate member 11 of the same shape provided at the front end of the side member 10. Etc. are concluded through.

  In FIG. 2 and subsequent figures, the crash box 3 disposed on the left side in the vehicle traveling direction is illustrated, but the crash box 3 disposed on the right side is also functionally equivalent and symmetrical with respect to the vehicle center. It is the shape.

  Specifically, the upper stay member 30 and the lower stay member 31 are formed in a shape as shown in FIG. In the present embodiment, the upper stay member 30 is formed in a shape inclined from the front end side (bumper beam 2 side) to the rear end side (side member 10 side). By attaching it so as to protrude from the top surface, the allowable input range of the collision load is expanded, and the influence of the difference in vehicle height is eliminated.

  In the present embodiment, an example in which the front end side of the upper stay member 30 protrudes from the upper surface of the bumper beam 2 will be described. However, either the upper stay member 30 or the lower stay member 31 is attached to the bumper beam 2. The front end side of the lower stay member 31 may protrude from the lower surface of the bumper beam 2 and may be attached. In that case, the relationship between the upper stay member 30 and the lower stay member 31 is reversed.

  In detail, the upper stay member 30 in the present embodiment is formed on the convex portions 30a projecting in a narrow ridge shape in the upward direction on both sides of the convex portions 30a, as shown in FIG. 4A. An upper hat portion (upper split member) of the box structure is formed by the flat plate-like flange portion 30b. The convex portion 30a is formed with an inclination so that the height from the flange portion 30b gradually decreases from the front (bumper beam 2 side) to the rear (side member 10).

  The upper stay member 30 and the lower stay member 31 are formed to have different strengths. In the present embodiment, the upper stay member 30 and the lower stay member 31 are formed of a sheet metal material of the same material such as a steel plate, and the plate thickness of the upper stay member 30 is made thinner than the plate thickness of the lower stay member 31. The strength of the upper stay member 30 is lower than the strength of the lower stay member 31.

  It should be noted that the upper stay member 30 and the lower stay member 31 may be formed of different materials so that the strength of the upper stay member 30 is lower than that of the lower stay member 31.

  On the other hand, as shown in FIG. 4 (b), the lower stay member 31 has a recess 31a formed in a downwardly wide groove shape and a flat flange portion 31b formed on both sides of the recess 31a. A lower hat portion (lower split member) of the structure is formed. The concave portion 31a is set so that the depth from the flange portion 30b reaches the substantially lower surface of the bumper beam 2 on the front side, and is formed so as to be inclined slightly downward toward the rear side (side member 10 side). . Further, on the front side of the lower stay member 31, left and right flange portions 31 c and a bottom flange portion 31 d are provided for fixing to the bumper beam 2.

  In the upper stay member 30 and the lower stay member 31, the flange portions 30b on both sides of the protrusion 30a and the flange portions 31b on both sides of the recess 31a are brought into contact with each other as upper and lower joint surfaces, and are joined by spot welding or the like. A box structure is formed. A plate member 32 is abutted against and fixed to the rear end portion of the box structure formed by joining the upper stay member 30 and the lower stay member 31 to form the crash box 3.

  The convex portion 30a of the upper stay member 30 and the concave portion 31a of the lower stay member 31 are joined with the bumper beam 2 side such that the axial center of the concave portion 30a is offset from the axial center of the concave portion 30a to the vehicle inner side ( 6), it is possible to input the collision load to the crash box 3 installed inside the offset portion 2b of the bumper beam 2 at an early stage.

  Such a crash box 3 is joined in a state where the front end side of the flange portion 30b of the upper stay member 30 is placed on the upper surface of the bumper beam 2 and the convex portion 30a is disposed so as to protrude from the upper surface of the bumper beam 2. The flange portion 31 c and the flange portion 31 d of the member 31 are joined to the side surface and the lower surface of the bumper beam 2. Further, the plate member 32 on the rear end side of the crash box 3 is brought into contact with the plate member 11 of the side member 10 and coupled by fastening with bolts.

  At this time, as shown in FIG. 5, the crush box 3 has a ridge line formed in the longitudinal direction by the flange portions 30 b and 31 b which are upper and lower joint surfaces of the upper stay member 30 and the lower stay member 31. It is attached between the bumper beam 2 and the side member 10 so as to extend parallel to the heart. Accordingly, when the box structure of the upper stay member 30 and the lower stay member 31 is viewed from the side, the front side protrudes from the upper surface of the bumper beam 2 with respect to the axial center of the side member 10, and extends toward the rear side (side member 10 side). The box structure extends so as to incline in parallel at the rear end.

  That is, when a barrier (obstacle) at a certain height collides with a vehicle equipped with the crash box 3, in a vehicle with a low ground height, the cross section is mainly upward due to the convex portion 30 a of the upper stay member 30. In a vehicle that receives a collision load at the upper part of the enlarged box structure and has a high ground clearance, the concave load 31a of the lower stay member 31 can mainly receive the collision load. At this time, in the box structure including the upper stay member 30 and the lower stay member 31, the ratio of the cross-sectional area occupied by the upper stay member 30 decreases and the ratio of the cross-sectional area occupied by the lower stay member 31 increases from the front to the rear. .

  As described above, the upper stay member 30 is formed of a member having a thinner plate thickness than the lower stay member 31 (see FIG. 6; in FIG. 6, the difference in plate thickness is emphasized). Due to the difference in plate thickness between the upper stay member 30 and the lower stay member 31 and the ratio of the cross-sectional areas (inclination angles and widths of the protrusions 30a and the recesses 31a), the drag force against the collision load increases toward the rear. Is set. For this reason, even if the vehicle height is different, the crash box 3 can be crushed sequentially from the front without escaping up and down, and the collision energy can be effectively absorbed.

  As described above, in this embodiment, the crash box 3 can be used in common for a high vehicle height with a high ground clearance and a low vehicle height with a low ground clearance, and even if there is a difference in vehicle height, The box 3 can be effectively crushed in the axial direction without escaping in the vertical direction. Thereby, the impact energy can be effectively absorbed to prevent the body shell from being damaged, and the impact energy can be effectively absorbed in cooperation with the bumper beam 2 to protect the occupant.

  In addition, since the crash box 3 has a simple configuration of a two-divided box structure of the upper stay member 30 and the lower stay member 31, an increase in cost can be suppressed. In addition, a box structure is formed by the upper stick member 30 and the lower stick member 31 having different plate thicknesses, and while maintaining the necessary cross-sectional area while changing the ratio of the two, the upper stick member having a thinner plate thickness toward the rear. By reducing the ratio of the cross-sectional area of 30, it is possible to realize an optimum characteristic that collapses sequentially in the axial direction.

DESCRIPTION OF SYMBOLS 1 Bumper apparatus 2 Bumper beam 3 Crash box 10 Side member 11 Plate member 30 Upper stay member (upper split member)
30a Convex 30b Flange 31 Lower stay member (lower split member)
31a Recessed part 31b Flange part 31c Flange part 31d Flange part 32 Plate member

Claims (4)

A bumper device that absorbs collision energy by interposing a crash box between a bumper beam and a side member of a vehicle,
The crash box is formed as a cylindrical box structure in which two split members are joined up and down and inclined from the bumper beam side toward the side member side,
One split member of the box structure is arranged so as to protrude vertically from the bumper beam, and a ridge line in the front-rear direction formed by a joint surface between the upper split member and the lower split member is the side A bumper device for a vehicle, wherein the bumper device is arranged so as to be parallel to an axial direction of the member.   The box structure is formed so that a ratio of a cross-sectional area between the lower split member and the upper split member changes from the bumper beam side toward the side member side. Vehicle bumper device.   The upper split member is disposed so as to protrude from the upper surface of the bumper beam, and the ratio of the cross-sectional area of the upper split member to the lower split member decreases from the bumper beam side toward the side member side. The vehicle bumper device according to claim 1, wherein the box structure is formed as described above.   The vehicle bumper device according to any one of claims 1 to 3, wherein the upper split member and the lower split member are formed with different strengths.

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