JP2019104333A - Crash box for vehicle - Google Patents

Abstract

To prevent deforming of a crash box for a vehicle so as to fall inward in a vehicle width direction in an event of a head-on collision of the vehicle.SOLUTION: A vehicle crash box 30 has an outer side vertical wall part 42, an inner side vertical wall part 52 spaced apart from the outer side vertical wall part 42 in an inner side of vehicle width direction, and a bead 54 formed on the inner side vertical wall part 52 and extending in a longitudinal direction of the vehicle in a side view.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crash box for a vehicle.

  In Patent Document 1, a crash can (crash box) having a rigidity lower than that of the side frame is provided between an end of the side frame extending in the front-rear direction of the vehicle and a bumper extending in the vehicle width direction. Discloses a technique for absorbing collision energy at the beginning of a vehicle collision.

  In this prior art, the crush can has a substantially cruciform cross section, and the four projecting portions thereof are disposed to extend in the front-rear direction of the vehicle in a state of being directed in the up, down, left, and right directions of the vehicle.

JP, 2010-70038, A

  The stress applied to the crash box for a vehicle at the time of a frontal collision of the vehicle is larger at the inner side in the vehicle width direction than at the outer side in the vehicle width direction, so the inner side in the vehicle width direction may be bent first. Then, if the vehicle width direction inner side is bent first at the time of a frontal collision of the vehicle, the vehicle crash box deforms so as to fall inward in the vehicle width direction, so energy absorption is achieved as compared with the case of compressive deformation in the ideal axial direction. The amount is reduced.

  An object of the present invention is to suppress deformation such that a crash box for a vehicle falls inward in the vehicle width direction in the event of a frontal collision in consideration of the above fact.

  The invention according to claim 1 is formed on an outer side wall portion formed by a flat surface, an inner side wall portion spaced apart from the outer side wall portion in the vehicle width direction, and the inner side wall portion. A vehicle crash box provided with a bead extending in the longitudinal direction of the vehicle in a side view.

  In the first aspect of the invention, the crash box for the vehicle reduces the buckling load by making the outer longitudinal wall portion with small stress applied at the time of frontal collision of the vehicle flat, and the inner side where the force applied at frontal collision of the vehicle is large. The buckling load is increased by forming a bead on the vertical wall. Therefore, it is suppressed that the inner vertical wall which has a large force applied at the time of a front collision of the vehicle is bent first, and the deformation so as to fall inward in the vehicle width direction is suppressed.

  According to the first aspect of the present invention, it is possible to suppress deformation such that the crash box for a vehicle falls inward in the vehicle width direction at the time of a frontal collision of the vehicle.

FIG. 1 is a perspective view of a front portion of a vehicle provided with a vehicle crash box according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows typically the front part of the vehicle provided with the crash box for vehicles of one Embodiment of this invention. (A) shows the distribution of the compressive load at the time of a front collision of the vehicle, and (B) shows the distribution of the moment at the time of a front collision of the vehicle. C) shows the distribution of stress at the time of a frontal collision of the vehicle.

Embodiment
A crash box for a vehicle according to an embodiment of the present invention will be described using FIGS. 1 to 3. In each of the drawings, arrow FR indicates the front side in the longitudinal direction of the vehicle, arrow UP indicates the upper side in the vertical direction of the vehicle, and arrow OUT indicates the outer side in the vehicle width direction. Further, FIG. 1 illustrates the right side in the vehicle width direction, but the left side in the vehicle width direction is also symmetrical except that it is symmetrical.

[Construction]
The structure of the vehicle crash box of the present embodiment will be described.

  As shown in FIG. 2, bumper reinforcement 12 is disposed at the front end of the vehicle 10 with the vehicle width direction as the longitudinal direction. The bumper reinforcement 12 has a round shape in which a central portion in the vehicle width direction bulges (projects) toward the vehicle front side in plan view. A front bumper cover (not shown) is attached to the vehicle front side of the bumper reinforcement 12.

  At both side portions in the vehicle width direction of the vehicle 10, side members 14 having a pair of left and right closed cross-sectional structures are disposed with the longitudinal direction of the vehicle as a longitudinal direction. The front end portion of the side member 14 is disposed at a position (offset position) separated from the bumper reinforcement 12 by a predetermined distance on the vehicle rear side.

  A pair of left and right vehicle crash boxes 30 is provided between the front end of the side member 14 and the rear surface of the bumper reinforcement 12. The front end of the vehicle crash box 30 is joined to the bumper reinforcement 12 and the rear end is joined to the front end of the side member 14.

  Note that FIG. 2 is a schematic view, and since the bumper reinforcement 12 is a line drawing, the joining portion with the crash box 30 for a vehicle appears to be joined at a point (line), but in reality it is It is joined.

  As shown in FIG. 1 and FIG. 2, the crash box 30 for a vehicle according to the present embodiment includes an outer portion 40 forming a vehicle width direction outer side having a substantially U-shaped cross section orthogonal to the vehicle longitudinal direction, and a vehicle width direction The inner part 50 which comprises an inner side is joined and comprised.

  Both side surfaces in the vehicle width direction of the vehicle crash box 30 are configured by an outer side vertical wall portion 42 and an inner side vertical wall portion 52 opposed to each other with an interval in the vehicle width direction. The outer side vertical wall part 42 which comprises a vehicle width direction outer side is comprised by the flat surface from the upper end of a vehicle up-down direction to a lower end.

  The inner vertical wall portion 52 constituting the inner side in the vehicle width direction is inclined at an angle θ inwardly in the vehicle width direction toward the rear side in the vehicle longitudinal direction with respect to the outer vertical wall portion 42 in plan view. A bead 54 convex inward in the vehicle width direction is formed on the inside vertical wall 52 along the vehicle longitudinal direction in a side view.

  That is, the bead 54 is not formed on the outer longitudinal wall 42 of the crash box 30 for a vehicle, but is formed only on the inner longitudinal wall 52.

[Action and effect]
Next, the operation and effects of the present embodiment will be described.

  FIG. 2 schematically shows a front collision of a vehicle in which a collision load F is input to an intermediate portion in the vehicle width direction of the crash boxes 30 on the left and right of the bumper reinforcement 12. 3A is a view showing the distribution of the compressive load at the time of a front collision of the vehicle in the cross section A-A of FIG. 2 of the crash box 30 for a vehicle, and FIG. 3B is a view showing the distribution of the moment. FIG. 3C is a view showing the distribution of stress.

  In addition,-direction in FIG. 3 shows the vehicle front-back direction rear side, and + direction has shown the vehicle front-back direction front side. In addition, the mark x in FIG. 3B indicates the position of the neutral axis in the cross section AA of FIG. 2 of the crash box 30 for a vehicle.

  Then, as shown in FIGS. 3A and 3B, a moment acts on the outer side in the vehicle width direction of the crash box 30 for the vehicle in the direction opposite to the compressive load (+ direction (front side in the vehicle longitudinal direction)). A moment acts on the inner side in the vehicle width direction in the same direction as the compression load (− direction (rear side in the vehicle longitudinal direction)). Therefore, the stress shown in FIG. 3C, which is the sum of the compressive load of FIG. 3A and the moment of FIG. 3B, is larger on the inner side in the vehicle width direction than on the outer side in the vehicle width direction.

  As shown in FIGS. 1 and 2, in the vehicle crash box 30 of the present embodiment, the outer longitudinal wall portion 42 on the outer side in the vehicle width direction is a flat surface on which no bead is formed, and the inner longitudinal inward in the vehicle width direction The wall 52 is formed with a bead 54. Therefore, in the crash box 30 for a vehicle, a buckling load (a load that starts buckling) of the inner longitudinal wall 52 having a large stress applied at the frontal collision of the vehicle has a smaller stress applied at the frontal collision of the vehicle. Larger than 42 buckling load.

  Therefore, in the crash box 30 for the vehicle, the inner longitudinal wall 52 having a large stress applied at the time of a frontal collision of the vehicle is restrained from being bent first, and the inner longitudinal wall 52 and the outer longitudinal wall 42 buckle substantially simultaneously. Start. Therefore, deformation in such a way as to fall inward in the vehicle width direction is suppressed, and it is close to compressive deformation (collapsing) in an ideal axial direction (in the present embodiment, the vehicle longitudinal direction). Therefore, the energy absorption amount of the crash box 30 at the time of a front collision of the vehicle is improved as compared with the case where the crash box 30 for vehicle is deformed so as to fall inward in the vehicle width direction.

  Further, the inclination of the inner vertical wall portion 52 and the inner convex bead 54 receive and regulate the deformation of the bumper reinforcement 12 due to the moment load acting on the bumper reinforcement 12 at the time of the frontal collision of the vehicle. Therefore, since the buckling of the bumper reinforcement 12 at the time of the frontal collision of the vehicle is suppressed, the collision load F input to the bumper reinforcement 12 is effectively transmitted to the crash box 30 for the vehicle.

  Thus, the collision load F input to the bumper reinforcement 12 is effectively transmitted to the vehicle crash box 30 by suppressing the buckling of the bumper reinforcement 12 at the time of a frontal collision of the vehicle, and the vehicle crash box Since the deformation that falls down inward in the vehicle width direction of 30 is suppressed and it becomes close to the ideal compressive deformation in the longitudinal direction of the vehicle, the collision load F is effectively absorbed by the crash box 30 for a vehicle.

<Others>
The present invention is not limited to the above embodiment.

  For example, although the bead 54 formed in the inner vertical wall part 52 of the crash box 30 for vehicles was one in the said embodiment, it is not limited to this. A plurality of beads may be formed at intervals in the vertical direction.

  Further, for example, in the above embodiment, the bead 54 formed on the inner vertical wall portion 52 of the crash box 30 for vehicle is convex inward in the vehicle width direction, but may be convex outward in the vehicle width direction .

  The point is that depending on the shape and number of the beads 54, the crash box 30 for the vehicle starts buckling at substantially the same time as the inner vertical wall 52 and the outer vertical wall 42 at the time of a frontal collision of the vehicle. It is sufficient to control the buckling load.

  Furthermore, the present invention can be implemented in various aspects without departing from the scope of the present invention.

30 Crash Box for Vehicles 42 Outer Vertical Wall 52 Inner Vertical Wall 54 Beads

Claims (1)

An outer longitudinal wall composed of a flat surface,
An inner longitudinal wall portion spaced at an inner side in the vehicle width direction of the outer longitudinal wall portion;
A bead formed on the inner longitudinal wall and extending in the longitudinal direction of the vehicle in a side view;
Crash box for vehicles with.