JPH0365634A - Arrangement position determining method of crushed bead - Google Patents

Abstract

PURPOSE:To easily determine the optimum position of a crushed bead by determining the arrangement position of the crushed bead to a dependent wall surface which is deformed corresponding to the pressing mode of a buckling wall surface, on the basis of a buckling waveform formed on the buckling wall surface subsequent to the press to the crushed bead in the poor state. CONSTITUTION:When it is confirmed that a buckling waveform is formed in a buckling wall surface 109, the buckling waveform is analyzed. Then, a required bead 105 is arranged in a position of a dependent wall surface 107 which is deformed in accordance with the pressing mode of a wall surface 109 opposite to the buckling wall surface 109. The position of the dependent wall surface is determined through analysis. For this analysis, when the buckling waveform represents accordion-like mode, the bead 105 is placed at the belly of a recessed portion of a buckling waveform 110 corresponding to positions (a) and (b). If the buckling waveform shows parallel mode, the bead 105 is placed at the belly of a protruding portion of the waveform 110 which corresponds to positions (c) and (d). The pressing mode and reaction force etc. of a side member provided with the bead 105 are confirmed through analysis of the pressing.

Description

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

(Prior Art) In vehicles and the like, collapsible beads (hereinafter simply referred to as "beads") are provided on members constituting the vehicle body to absorb energy from loads caused by collisions and protect occupants. Allocation of beads to members W1! ! There are various types of vehicles, such as the vehicle 1 shown in FIGS. 7 and 8.
Regarding the side member 103 that forms the skeleton of the engine room section 101 of 00, FIGS. 9(2) to 9(υ
As shown in FIG.
Alternatively, there is a mode in which it is installed on a wall surface. In either case, when the side member 103 is crushed in the axial direction A, bending of the side member 103 is prevented, and the side member 103
By sequentially crushing from the tip in the axial direction A, crushing energy can be appropriately absorbed.

(Problems to be Solved by the Invention) Incidentally, the placement position of the bead on the member is determined by trial and error by actually crushing the member repeatedly.

For this reason, not only does it take a lot of time and money to make the decision, but there is also the possibility that the optimal 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 a method for determining the arrangement position of collapsed beads that can easily determine the optimum position of the beads.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for determining the placement position of a crush bead on a strength member that receives a crushing load, a step of crushing at least until the maximum generated load point is exceeded in a state where there is no bead; a step of confirming the buckling wall surface where a buckling waveform is formed by crushing the strong all material; and analyzing the buckling waveform; The method further comprises the step of determining, based on the buckling waveform, the arrangement of the crushing bead on the dependent wall surface that deforms according to the crushing mode of the buckling wall surface.

(Function) In the method for determining the placement position of a crush bead according to the present invention, a seat is formed on a buckling wall surface by crushing a strength member in which a crush bead is to be placed, in a state 'ta- where there is no crush bead. Based on the bending waveform, the placement position of the crushing bead on the dependent wall surface that deforms according to the crushing mode of the buckling wall surface is determined.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows a flowchart of a process for determining the position of a bead according to an embodiment in which the present invention is applied to determining the position of a bead at a corner of the side member 103. As shown in FIG. 2, the feature of the method for determining the bead arrangement position according to this embodiment is that the bead 105 arranged at the corner of the side member 103 acts to fold the pressed Li wall surface 107 inward, that is, to crush it. Making use of the function of promoting the severe deformation of the wall surface 107, the crushing pitch of the buckling waveform 110 formed on the buckling wall surface 109 and the crushing pitch of the crushing wall surface (subordinate wall surface) 107 that faces it are reconciled. The objective is to guide the side member 103 to circular collapse with high energy absorption efficiency.

Specifically, first, the side member in which no bead is formed is crushed according to the characteristics shown in FIG. 3. According to such crushing occurs maximum.

Since a buckling waveform occurs in the region S beyond the load point P, the buckling wall surface 109 where the eight buckling waves have occurred is confirmed, and the buckling waveform is analyzed (step 1.2).

Then, based on this analysis, the required bead 105 is placed at the position determined in the analysis on the dependent wall surface 107 that is opposite to the buckled wall surface 109 and deforms according to the crushing mode of the buckled wall surface 109 (step 3). In this analysis, the position of the bead 105 is set to a position corresponding to the antinode of the concave portion of the buckling waveform 110 when the buckling waveform is in the so-called accordion-like crush mode, as shown in FIG.
O2υ, and in the case of the so-called parallel crush mode, it corresponds to the antinode of the convex part of the buckling waveform 110 (Fig. 4 (2)
) and (2), respectively. In addition. In FIG. 4, U, 111 is the crushing mode by the bead 105.

For the side member 103 on which the bead 105 is arranged in the manner described above, a crushing analysis is performed to confirm the crushing mode, reaction force, etc. (step 4).

The effect of installing the bead 105 on the side member 103 according to this embodiment is shown in FIGS. 5 and 6.

5 and 6 show the cases of the accordion-like crush mode and the parallel-like crush mode, respectively, and in both figures, (2) is a diagram showing the installation situation of the bead 105,
(0) is a diagram showing the crushing situation of side member 103.
2 is a diagram showing load displacement characteristics with and without a bead 105. FIG. As shown in FIG. 5(b) and FIG. 6(0), by setting the mode 105 according to this embodiment, the side member 103 is prevented from being axially crushed. In addition, as shown in FIG. 5 (2) and FIG. 6 (2), it is recognized that the energy absorption efficiency is higher in the case where the bead 105 according to this embodiment is installed than in the case without the bead.

As described above, according to the present embodiment, it is possible to determine the optimum bead position without spending much time and expense, compared to the conventional method, which was performed by trial and error.

[Effects of the Invention] As explained above, according to the present invention, the strength member on which the crushing bead is arranged (based on the buckling waveform formed on the buckling wall surface due to crushing in the absence of the crushing bead) Since the placement position of the collapse bead on the dependent wall surface that deforms according to the collapse mode of the buckled wall surface is determined, the optimal position of the collapse bead can be determined more easily than in the past.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a processing flowchart of an embodiment of the present invention, Figs. 2 to 44 are diagrams for explaining the processing of the embodiment, and Figs. FIGS. 7 to 9 are diagrams for explaining the effects, and FIGS. 7 to 9 are diagrams for explaining the prior art. 100...Vehicle 101...Engine room part 103...Side member 105...Bead 107...Crushed wall surface (subordinate wall surface) 109...Buckled wall surface 110...Buckled corrugated portion Immediately Patent attorney load Figure 1 Figure 3 Figure 2 Figure 5 (a) Figure 5 (b) Figure 5 (C) Figure 6 (a) Figure 6 (b) Figure 6 (C) 100 / Figure 7 Figure 8 Figure 05 (c) Figure 9

Claims (1)

[Claims] This is a method of determining the placement position of a crush bead on a strength member that receives a crushing load, and includes the steps of crushing the strength member until at least the maximum generated load point is exceeded in a state where there is no collapse bead, and A process of confirming the buckled wall surface where the buckling waveform is formed and analyzing the buckling waveform, and arranging the collapse bead on the dependent wall surface that deforms according to the crushing mode of the buckled wall surface based on the buckling waveform. 1. A method for determining the placement position of a crushed bead, the method comprising the step of: