JP2727680B2 - How to determine bead placement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a bead arrangement determining method for determining an arrangement of beads on a strength member subjected to a crushing load.

2. Description of the Related Art In a vehicle or the like, a bead for absorbing energy caused by a load due to a collision or the like and protecting an occupant is provided on a member constituting a vehicle body. There are various types of arrangements of the beads on the members. For example, regarding the side member 103 forming the skeleton of the engine room portion 101 of the vehicle 100 shown in FIGS. 5 and 6, FIG. As shown in FIGS. 7 (c) to 7 (c), there is a mode in which the bead side member 103 is provided at a corner (corner bead) and / or a wall surface (wall bead). In any case, when the side member 103 is crushed in the axial direction A, the side member 103 is prevented from being bent and the side member 103 is sequentially crushed from the tip in the axial direction A. Can be properly absorbed.

(Problems to be Solved by the Invention) By the way, what kind of bead is to be arranged at which position with respect to the member is determined by trial and error by actually crushing the member repeatedly. For this reason, in addition to taking a lot of time and money for the determination, there is a possibility that an optimum bead and its position may not always be obtained despite the great amount of time and money.

The present invention has been made in view of the above, and an object of the present invention is to provide an optimum bead and a bead arrangement determining method capable of easily determining an optimum bead position.

[Constitution of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention relates to a bead arrangement determining method for determining an arrangement of beads on a strength member subjected to a crushing load. The step of determining the state of occurrence of the buckling waveform immediately after applying a crushing load exceeding the peak load point in the absence of the bead, and the state of occurrence of the buckling waveform determined in the step is the inner surface of the wall surface of the strength member. In the case of a depressed concave portion, a concave wall bead is arranged at the position where the concave portion is generated, and in the case where the state of occurrence of the buckling waveform is a convex portion in which the wall surface of the strength member protrudes outside the surface, the convex portion is formed. Determining that the convex wall bead is arranged at the position where the portion is generated.

(Operation) In the bead arrangement determining method according to the present invention, the strength member on which the bead is to be arranged is formed based on the buckling waveform in the initial stage of crushing without the bead. The placement position is determined.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a processing flowchart according to an embodiment when the present invention is applied to determination of a bead arrangement on a side member 103. As shown in FIG. 2, the bead arranging method according to the present embodiment is characterized in that a square bead has an excellent load reducing effect, and a concave and a convex wall beat have a concave deformation promoting effect and a convex deformation promoting effect on the wall surface, respectively. In consideration of the characteristic of each bead that is excellent in the shape of the buckling waveform 110 formed on the side member 103 (see FIG. 3 (A)), as shown in FIG. The mold wall beads 109 and 111 are arranged (see FIG. 3 (B)), and the square beads 113 are arranged only in the concave portion closest to the collision end side (see FIG. 3 (C)), and the peak load value is reduced. By holding down and maintaining the average crush load value, the side members 103
To promote crushing in the axial direction.

More specifically, a buckling waveform 110 immediately after the peak load without a bead is obtained for the side member 103 for which the following calculation is performed using a computer, for example, by a numerical analysis using a finite element method (step 1). With respect to the obtained buckling waveform 110, a concave wall bead 109 is disposed in the concave portion for depressing the wall surface inward, and a convex wall bead 111 is disposed in the convex portion for protruding the wall surface outward (step 2). ). Further, a corner bead 113 is arranged at the corner of the concave portion on the side of the collision end closest to the side member 103 (step 3). And
The crushing mode and the reaction force characteristics of the side member 103 having the bead arrangement determined as described above are obtained to confirm the crushing promoting effect (step 4).

The side member 103 where the bead arrangement is determined in this way.
As shown in FIG. 4, it can be seen that, as shown in FIG. 4, the peak load is suppressed as compared with the case without the bead, and the transition to the axial crushing is facilitated.

Therefore, according to the present embodiment, compared to the conventional method that is performed by trial and error, it can be performed by calculation using a computer, so that it does not require much time and cost,
An optimum bead and its position can be determined, and thus a strength member such as a side member can be guided to axial crush with high energy absorption efficiency.

[Effects of the Invention] As described above, according to the present invention, the arrangement of the concave and convex wall beads based on the buckling waveform in the initial stage of crushing of the strength member where the beads are to be arranged without the beads. Since the position is determined, an optimum bead and its position can be easily determined as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a diagram showing a processing flowchart of one embodiment of the present invention, FIGS. 2 to 4 are diagrams for explaining the processing of the embodiment, and FIGS. FIG. 100 vehicle 101 engine room 103 side member 105 bead 110 buckling waveform 109 concave wall bead 111 convex wall bead 113 square bead

Claims (1)

(57) [Claims] 1. A method for determining the arrangement of beads on a strength member subjected to a crushing load, wherein the buckling is performed immediately after a crushing load exceeding a peak load point is applied to the strength member without a bead. A step of determining the state of generation of the waveform; and, in a case where the state of generation of the buckling waveform determined in the step is a concave portion in which the wall surface of the strength member is depressed inward, a concave wall bead is arranged at a position where the concave portion is generated. And determining that the buckling waveform is generated such that a convex wall bead is disposed at a position where the convex portion is generated when the buckling waveform is generated by projecting the wall surface of the strength member outward. A method for determining a bead arrangement, comprising: