JP2017177863A - Automobile impact absorbing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile impact absorbing device capable of increasing absorbing amount of the impact energy while suppressing mass increase.SOLUTION: An automobile impact absorbing device includes: crash boxes 12 of which axial lines are extending in the forward-backward direction on each of both sides in a vehicle width direction, each of the crash boxes 12 including a cylindrical portion 21 of which axial line extending in the vehicle forward-backward direction and a spiral stepped portion 22 in which the cylindrical portion 21 is displaced in the radial direction so as to gradually reduce the diameter as heading towards the front of the vehicle; and a reinforcement member 13 extending in the vehicle width direction and each of which both end portions is attached to the front end surface of the crash box 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an automobile impact absorbing device.

  Conventionally, as an automobile impact absorbing device, for example, the one described in Patent Document 1 is known. This shock absorber for an automobile has a pair of crash boxes (crash cans) extending in the front-rear direction on both sides in the width direction at the front portion of the vehicle, and extends in the width direction of the vehicle so that both end portions in the direction are both crash boxes. There is a reinforcing member (bumper reinforcement) attached to the front end surface.

  Each crash box includes a cylindrical portion that extends in the front-rear direction of the vehicle, and the cylindrical portion has a plurality of step portions at an intermediate portion in the front-rear direction of the vehicle. The cylindrical portion is shaped so that the reinforcing member side has a relatively small diameter by bending the peripheral wall in a stepped manner at each step portion. In this case, for example, when the automobile collides, the cylindrical portion undergoes axial compression deformation (so-called bellows deformation) sequentially from the front end side (small diameter side), so that the transition of the axial compression deformation is further stabilized and efficient. Impact energy can be absorbed.

JP 2012-166645 A

By the way, in Patent Document 1, the impact energy is absorbed even when the reinforcing member is deformed (deformation in the front-rear direction of the vehicle) at the time of a car collision. In other words, the amount of shock energy absorbed by the automobile shock absorber is an additive amount of shock energy corresponding to the axial compression deformation of each crash box and the deformation of the reinforcing member. Therefore, in order to increase the amount of shock energy absorbed by the automobile impact absorbing device, the following methods can be roughly classified.
・ Reinforcement of each crash box or reinforcing member ・ Increase in size of each crash box or reinforcing member in the longitudinal direction of the vehicle However, no matter which method is used, the mass of each crash box or reinforcing member increases. Problems will arise.

  An object of the present invention is to provide an automobile impact absorbing device capable of increasing the absorption amount of impact energy while suppressing an increase in mass.

  A shock absorber for an automobile that solves the above-described problem is a crash box having an axis extending in the front-rear direction on each of both sides in the width direction of the vehicle, and a cylinder portion extending in the front-rear direction of the vehicle, and one side in the front-rear direction of the vehicle A crush box having a spiral step portion that is displaced in the radial direction so that the diameter of the cylindrical portion is gradually reduced as it goes toward the vehicle, and each of the end portions in the direction extending in the vehicle width direction is the crush box. And a reinforcing member attached to the front end surface in the front-rear direction of the vehicle.

  According to this configuration, for example, at the time of an automobile collision, the cylindrical portion is induced by the spiral step when the shaft is deformed by axial compression, and the crash box is twisted and deformed around the axis. A moment (torque) of the force generated by this torsional deformation is transmitted to the reinforcing member. Accordingly, the reinforcing member absorbs impact energy due to bending deformation in the vertical direction of the vehicle, in addition to absorbing impact energy due to deformation in the longitudinal direction of the vehicle. For this reason, the absorption amount of the impact energy as the whole apparatus can be increased without increasing the mass of each crash box or the reinforcing member.

About the said shock absorber for motor vehicles, it is preferable that the winding direction of the said step part is mutually opposite in the said both crash boxes arrange | positioned at the width direction both sides of a vehicle.
According to this configuration, for example, when the impacts applied to the two crash boxes are substantially equal, such as when an automobile collides, the torsional deformations are transmitted symmetrically to the reinforcing member in the width direction of the vehicle. Therefore, the deformation posture of the reinforcing member can be further stabilized.

  The present invention has an effect of increasing the absorption amount of impact energy while suppressing an increase in mass.

The top view which shows the structure about one Embodiment of the shock absorber for motor vehicles. The perspective view which shows a crash box. The rear view which shows the effect | action about the shock absorber for motor vehicles of the embodiment. The graph which shows the relationship between the deformation | transformation amount and load which simulated with the crash box single-piece | unit compared with the conventional form.

  Hereinafter, an embodiment of an automobile impact absorbing device will be described. In the following, the front-rear direction of the vehicle is referred to as “front-rear direction”, the up-down direction of the vehicle is referred to as “up-down direction”, and the width direction of the vehicle is referred to as “width direction”.

  As shown in FIG. 1, a pair of side members 11 that extend in the front-rear direction on both sides in the width direction and constitute a part of the body are disposed at the front portion of the automobile. A pair of metal crush boxes 12 are attached to the front ends of the side members 11 so as to be substantially concentric with them. As shown in FIG. 2, the crash box 12R on one side (right side toward the front of the vehicle) includes a substantially cylindrical tube portion 21 having an axial line extending in the front-rear direction and the front (one side in the front-rear direction of the vehicle). It has a spiral step portion 22 that is displaced in the radial direction so that the diameter of the cylindrical portion 21 is gradually reduced as it goes toward.

  The winding direction of the stepped portion 22 is set so as to rotate clockwise from the center side toward the radially outer side when viewed from the front. The crash box 12 </ b> R has a substantially disk-shaped lid wall 23 that closes the opening in front of the cylindrical portion 21. The crash box 12R is attached to the side member 11 directly or via an appropriate bracket in the opening at the rear of the cylindrical portion 21.

  Note that the crash box 12L on one side (left side toward the front of the vehicle) has the same structure as that except that it is symmetric (laterally symmetric) with the crash box 12R in the width direction. Accordingly, the winding direction of the step portion 22 of the crash box 12L is set so as to rotate counterclockwise from the center side toward the radially outer side as viewed from the front.

  As shown in FIG. 1, both end portions of the substantially elongated reinforcing member 13 made of a metal material extending in the width direction are attached to the front end surfaces (front and rear end surfaces of the vehicle) of both crash boxes 12. It is worn.

Next, the effect of this embodiment will be described.
(1) For example, when an impact is applied from the front during an automobile collision, the impact is transmitted from the reinforcing member 13 to the body (side member 11) via each crash box 12. At this time, as shown in FIG. 3, when the cylindrical portion 21 of each crash box 12 is axially compressed and deformed, it is induced by the spiral step portion 22, and the crash box 12 is twisted and deformed around its axis. Needless to say, the direction of the twist deformation correlates with the winding direction of the stepped portion 22. A moment (torque) of the force generated by this torsional deformation is transmitted to the reinforcing member 13. Thereby, the reinforcing member 13 absorbs impact energy by bending deformation in the vertical direction in addition to absorption of impact energy by deformation in the front-rear direction. For this reason, the absorption amount of the impact energy as the whole apparatus can be increased without increasing the mass of each crash box 12 or the reinforcing member 13. And the impact added to a body and a passenger | crew can be relieved.

  (2) In the present embodiment, in both the crash boxes 12R and 12L, the winding directions of the stepped portions 22 are opposite to each other. Therefore, if the impact applied to both the crash boxes 12R and 12L is approximately equal, for example, when the car is in a forward collision, their torsional deformation is transmitted to the reinforcing member 13 symmetrically (laterally symmetrical) in the width direction. Therefore, the deformation posture of the reinforcing member 13 can be further stabilized.

  (3) The step portion 22 of the crash box 12 is spirally continuous over substantially the entire length of the tube portion 21 in the front-rear direction, so that, for example, the tube portion compared to the conventional form (the crash box of Patent Document 1). 21 stepwise axial compression deformation can be further smoothed. Therefore, as shown in FIG. 4, in the crash box 12 of this embodiment, the fluctuation range of the load with respect to the deformation amount can be reduced as compared with the conventional embodiment, and even the crash box 12 alone absorbs the impact energy more efficiently. it can.

  (4) In the present embodiment, each of the crash boxes 12 can lie down on the side member 11 side so that the crash box 12 starts from the coupling position with the side member 11 because the diameter of the cylindrical portion 21 is increased on the side member 11 side. Property can be further reduced, and as a result, more stable impact energy can be absorbed.

In addition, you may change the said embodiment as follows.
-In the above-mentioned embodiment, both crush boxes 12R and 12L may have the winding direction of step part 22 the same direction mutually.

In the above-described embodiment, each crash box 12 may be attached so that the diameter of the cylindrical portion 21 is increased on the reinforcing member 13 side.
In the embodiment, the cylindrical portion 21 is substantially cylindrical, but may be, for example, a substantially polygonal cylindrical shape or a substantially long cylindrical shape. Moreover, although the step part 22 was made into the substantially circular spiral shape following the cylinder part 21, it may be a substantially polygonal spiral shape or a substantially oval spiral shape according to the above-mentioned cylinder part.

  12, 12L, 12R ... crush box, 13 ... reinforcing member, 21 ... cylinder part, 22 ... step part.

Claims (2)

A crash box having an axial line extending in the front-rear direction on each of both sides in the width direction of the vehicle, and the diameter of the cylindrical part is gradually reduced toward the one side in the front-rear direction of the vehicle. A crush box having a spiral step that is displaced in the radial direction so that
An automobile impact absorbing device comprising: a reinforcing member that extends in a width direction of the vehicle, and each of both end portions in the direction is attached to a front end surface of the crash box in the front-rear direction. The shock absorber for an automobile according to claim 1,
The impact absorbing device for an automobile, wherein the two crash boxes disposed on both sides in the width direction of the vehicle have the steps wound in opposite directions.

Images