JP5217456B2 - Front side member structure - Google Patents

Description

  The present invention relates to a structure of a front side member disposed along a longitudinal direction of a vehicle body at a lower portion of a front portion of a vehicle body.

  Front side members are disposed along the vehicle front-rear direction on the left and right sides in the vehicle width direction at the lower part of the front part of the vehicle body. In such a front side member, a bead is generally formed on a side surface of the front side member in order to absorb impact energy due to the collision at the front side of the vehicle.

  For example, the front side member has a polygonal cross section, and a plurality of beads oriented in a direction perpendicular to the axis of the front side member are provided at regular intervals along the vehicle body longitudinal direction on the side surface on the engine room side of the side surface. A front side member structure has been proposed (see, for example, Patent Document 1).

If a plurality of beads are provided at regular intervals along the longitudinal direction of the vehicle body as in Patent Document 1, the portion provided with the beads is actively crushed at the time of frontal collision of the vehicle, and the impact force due to the collision is efficiently absorbed. can do.
JP 2001-158377 A

  However, in the above-described conventional technology, a plurality of beats are formed at regular intervals on the side surface of the front side member, and each bead is discontinuous. Therefore, the collapse of the front side member at the time of a frontal collision is controlled as designed. There is a problem that it is difficult to do.

  In the conventional technique, each bead is formed so as to reach the ridgeline of the front side member. Therefore, the ridgeline has a waveform in a portion where a plurality of beats are formed at regular intervals. Thus, if the ridgeline of the front side member is a waveform, it is difficult to predict how much reaction force will be at the ridgeline. In this respect as well, the collapse of the front side member at the time of a vehicle front collision is controlled as designed. There is a problem that it is difficult.

  In addition, there is a possibility that the remaining crush occurs in a portion where a plurality of beats are not formed, and the impact due to the collision cannot be sufficiently absorbed.

  An object of the present invention is to provide a front side member structure that can control the collapse of the front side member at the time of a vehicle front collision as designed, and can sufficiently absorb the impact caused by the collision.

In order to solve the above-described problems, the present invention is provided with a front side member having a rectangular closed cross section with a ridge line in the longitudinal direction of the vehicle body, and two front surfaces of the front side member facing each other. wavy bead in the longitudinal direction of the vehicle body extend continuously without contacting the edge line toward the rear from the front of the side members, are formed side by side in plurality longitudinal direction of the vehicle body, said bead, valley depth of the corrugations However, the front side member is deeper on the front side and gradually becomes shallower as it approaches the rear side .

According to the above configuration, since the front side member is formed with the wavy bead that continuously extends in the front-rear direction of the vehicle body from the front part to the rear part of the front side member on the surface having the ridge line as one side. The depth of the valley of the front side member is set deeper on the front side of the front side member, and gradually becomes shallower as it approaches the rear side, or the interval between the valleys of the wavy portions and the valleys or the interval between the peaks and the peaks is set. By changing the setting in various ways, it is possible to control the collapse of the front side member at the time of a vehicle front collision as designed.

Further, since the bead is formed without contacting the ridge line of the front side member, the ridge line is maintained in a straight line, and as a result, the magnitude of the reaction force at the ridge line at the time of the vehicle front collision can be predicted. In addition, since a plurality of beads are formed side by side in the longitudinal direction of the vehicle body, it is possible to increase the reaction force of the front side member at the time of frontal collision of the vehicle . Also in these respects, the front side member is crushed. It can be controlled as designed.

  Further, since the wavy bead continuously extends in the longitudinal direction of the vehicle body, the front side member is easily crushed at the time of the frontal collision of the vehicle, and as a result, the impact due to the collision can be sufficiently absorbed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the front side member structure which can control the collapse of the front side member at the time of a vehicle front collision as designed value, and can fully absorb the impact by a collision.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an external perspective view of a front side member according to the present invention. FIG. 1 shows a front side member arranged on the right side of the vehicle body, and the front side member arranged on the left side of the vehicle body is symmetrical with respect to the front side member of FIG. It has become a shape. In FIG. 1, FR indicates the vehicle body front side, IN indicates the vehicle width direction inner side, and UP indicates the vehicle body upper side.

  The front side member 1 includes a front side member inner 2 having a hat-shaped cross section and a front side member outer 3 having a hat-shaped cross section.

  The front side member inner 2 is provided with a convex portion 4 having a U-shaped cross section provided at the center in the vertical direction of the vehicle body, an upper flange portion 5 formed by bending the upper end of the convex portion 4 upward, The lower end portion of the portion 4 has a lower flange portion 6 formed by bending downward. The convex portion 4 is provided so as to protrude inward in the vehicle width direction, and is formed of a vertical wall 4A, an upper wall 4B above the vertical wall 4A, and a lower wall 4C below the vertical wall 4A.

  The front side member outer 3 is provided with a convex portion 7 having a U-shaped cross section provided at the center in the vertical direction of the vehicle body, an upper flange portion 8 formed by bending the upper end portion of the convex portion 7 upward, The lower end portion of the portion 7 has a lower flange portion 9 formed by bending downward. The convex portion 7 is provided so as to protrude outward in the vehicle width direction, and is formed of a vertical wall 7A, an upper wall 7B above the vertical wall 7A, and a lower wall 7C below the vertical wall 7A. The vertical wall 7A and the vertical wall 4A of the front side member inner 2 are disposed to face each other.

  The upper flange portion 5 of the front side member inner 2 and the upper flange portion 8 of the front side member outer 3 are joined to each other by spot welding or the like. Further, the lower flange portion 6 of the front side member inner 2 and the lower flange portion 9 of the front side member outer 3 are also joined to each other by spot welding or the like. Thereby, the front side member 1 forms the rectangular closed cross section.

  In the present embodiment, a wavy bead that continuously extends in the longitudinal direction of the vehicle body from the front part to the rear part of the front side member 1 is formed on the vertical wall 4A of the convex part 4 of the front side member inner 2, which is the side surface of the front side member 1. 10 is formed. Further, a wave-like bead 11 continuously extending in the longitudinal direction of the vehicle body from the front part to the rear part of the front side member 1 is also provided on the vertical wall 7A of the convex part 7 of the front side member outer 3 which is the side surface of the front side member 1. Is formed.

  FIG. 2 is a cross-sectional view taken along line SA-SA in FIG. As shown in FIG. 2, the bead 10 has valleys 10 </ b> A, 10 </ b> B, 10 </ b> C protruding from the inside of the closed cross section of the front side member 1, and the tops of the peaks 10 </ b> D, 10 </ b> E of the bead 10 are It substantially coincides with the outer surface of the vertical wall 4A. Further, the bead 11 is formed such that each trough portion 11A, 11B, 11C protrudes to the inside of the closed cross section of the front side member 1, and each peak portion 11D, 11E of the bead 11 is outside the vertical wall 7A. It almost matches the surface.

  As shown in FIG. 1, the bead 10 is not in contact with the upper ridge line 12 of the front side member inner 2, and a vertical wall 4 </ b> A exists between the upper ridge line 12 and the bead 10. Further, the bead 10 is not in contact with the lower ridge line 13 of the front side member inner 2, and the vertical wall 4 </ b> A exists between the lower ridge line 13 and the bead 10. Similarly, the bead 11 is not in contact with the upper ridge line 14 of the front side member outer 3, and the vertical wall 7 </ b> A exists between the upper ridge line 14 and the bead 11. Further, the bead 11 is not in contact with the lower ridge line 15 of the front side member outer 3, and the vertical wall 7 </ b> A exists between the lower ridge line 15 and the bead 11.

  The bead 10 is not in contact with the front end edge 16 and the rear end edge 17 of the front side member inner 2, and is between the front end edge 16 and the bead 10 and between the rear end edge 17 and the bead 10. There is a vertical wall 4A. The bead 11 is not in contact with the front end edge 18 and the rear end edge 19 (see FIG. 2) of the front side member 1, but between the front end edge 18 and the bead 11 and between the rear end edge 19 and the bead. A vertical wall 7 </ b> A exists between 11 and 11.

  The beads 10 and 11 are formed in a range W along the vertical direction of the vehicle body. In this range W, the same shape is obtained when the beads 10 and 11 are cut along a plane parallel to the horizontal plane including the SA-SA line. .

  As shown in FIG. 2, in the bead 10, the depth of the trough portions 10 </ b> A, 10 </ b> B, and 10 </ b> C of the wavy portion is deep on the front side of the front side member 1 and approaches the rear side. It has become shallower. That is, the depth of the valley portion 10A> the depth of the valley portion 10B> the depth of the valley portion 10C is set. Similarly, in the bead 11, the depth of the trough portions 11A, 11B, and 11C (the depth inward in the vehicle width direction) of the wavy portion is the depth of the trough portion 11A> the depth of the trough portion 11B> the depth of the trough portion 11C. It is set like this.

  Further, in the bead 10, the interval between the valleys of the wave-like portions or the interval between the peaks and the peaks is short on the front side of the front side member 1 and becomes longer as it approaches the rear side. That is, the interval between the valley portion 10A and the valley portion 10B <the interval between the peak portion 10D and the peak portion 10E <the interval between the valley portion 10B and the valley portion 10C is set. Similarly, the bead 11 is also set such that the interval between the valley 11A and the valley 11B <the interval between the peaks 11D and 11E <the interval between the valley 11B and the valley 11C.

  Next, the operation of this embodiment will be described.

  As described above, in the front side member 1 in the present embodiment, the depths of the valley portions 10A, 10B, 10C and 11A, 11B, 11C of the wavy portions are deep on the front side of the front side member 1 and on the rear side. It is set shallower as it approaches, and also, among the valleys 10A, 10B, 10C and 11A, 11B, 11C of the wavy portions, the interval between adjacent valleys, or the interval between the peaks 10D, 10E and the peaks 11D, 11E. Since the interval between the front side members 1 is set to be shorter on the front side and closer to the rear side, the front side of the front side member 1 is less resistant to impact force than the rear side. ing.

  Therefore, at the time of a vehicle collision (at the time of a front collision), first, the valley portions 10A and 11A are crushed, then the valley portions 10B and 11B are crushed, and then the valley portions 10C and 11C are crushed. The front side member 1 is compressed and deformed into a bellows shape as shown in FIG. When being compressed and deformed, the front side member 1 absorbs an impact force caused by a collision. In FIG. 3, a two-dot chain line indicates the front side member 1 before being compressed and deformed.

  According to the present embodiment, the wavy beads 10 and 11 that continuously extend in the longitudinal direction of the vehicle body from the front part to the rear part of the front side member 1 are formed on the vertical walls 4A and 7A that are the side surfaces of the front side member 1, respectively. Therefore, the depth of the troughs 10A, 10B, 10C and 11A, 11B, 11C of the wavy portions, and between the troughs adjacent to each other among the troughs 10A, 10B, 10C and 11A, 11B, 11C of the wavy portions By setting the interval or the interval between the peaks 10D and 10E and the interval between the peaks 11D and 11E in various ways, it is possible to control the collapse of the front side member 1 at the time of the vehicle front collision as designed. it can.

  Further, since the bead 10 is arranged without contacting the ridge lines 12 and 13 of the front side member 1 and the bead 11 is arranged without contacting the ridge lines 14 and 15 of the front side member 1, the ridge lines 12, 13, 14, 15 is maintained in a straight line shape, and as a result, it is possible to easily predict how large the reaction force at the ridgelines 12, 13, 14, and 15 at the time of a vehicle front collision is.

  FIG. 4 shows a second embodiment. In the present embodiment, a wavy bead 20 is provided on the upper wall 4B of the front side member inner 2, and a wavy bead 21 is provided on the lower wall 4C of the front side member inner 2. These beads 20 and 21 are set so that the depth of the trough portion of the wave-like portion is deep on the front side of the front side member 1 and shallow as it approaches the rear side, as with the beads 10 and 11 in the first embodiment. The interval between the troughs and the troughs of the wavy portion or the interval between the crests and the crests is set shorter on the front side of the front side member 1 and longer as it approaches the rear side. The beads 20 and 21 are formed without contacting the ridge lines 12 and 13 of the front side member inner 2.

  The front side member 1 in the present embodiment can also obtain the same effects as the first embodiment. Further, according to the present embodiment, the bead processing is performed only on the front side member inner 2, and the bead processing is not required on the front side member outer 3, so that the processing becomes easy.

  FIG. 5 shows a third embodiment. In this embodiment, the first embodiment and the second embodiment are combined, and a bead 10 is provided on the vertical wall 4A of the front side member inner 2 and a bead 11 is provided on the vertical wall 7A of the front side member outer 3, Further, a bead 20 is provided on the upper wall 4A of the front side member inner 2, and a bead 21 is provided on the lower wall 4C of the front side member inner 2.

  The front side member 1 in the present embodiment can also obtain the same operational effects as the first and second embodiments. Further, according to the present embodiment, the beads 10, 11, 20, and 21 are provided at four locations of the front side member 1 in the vertical wall portion along the vehicle body vertical direction and the left and right wall portions along the vehicle width direction. Therefore, it is possible to efficiently absorb the collision energy at the time of the vehicle front collision.

  FIG. 6 shows a fourth embodiment. In the present embodiment, two wavy beads 30 and 31 are provided in parallel in the longitudinal direction of the vehicle body on the vertical wall 4A of the front side member inner 2. Similarly, two wavy beads 32 and 33 are provided in parallel with the longitudinal wall 7A of the front side member outer 3 in the front-rear direction of the vehicle body.

  These beads 30, 31, 32, and 33 are also set like the beads 10 and 11 in the first embodiment, where the depth of the trough portion of the wavy portion is deep on the front side of the front side member 1 and becomes shallower as it approaches the rear side. In addition, the interval between the troughs and the troughs of the wavy portions or the interval between the crests and the crests is set to be shorter on the front side of the front side member 1 and longer as it approaches the rear side. The beads 30 and 31 are formed without contacting the ridge lines 12 and 13 of the front side member inner 2, and the beads 32 and 33 are formed without contacting the ridge lines 14 and 15 of the front side member outer 3.

  The front side member 1 in the present embodiment can also obtain the same effects as the first embodiment. Further, since the vertical wall 4A of the front side member inner 2 exists between the beads 30 and 31, and the vertical wall 7A of the front side member outer 3 exists between the beads 32 and 33, the vertical walls 4A and 7A The reaction force can be increased.

  7 to 10 show modified examples of the wavy portions of the beads formed on the vertical wall 4A of the front side member inner 2 and the vertical wall 7A of the front side member outer 3. FIG.

  In FIG. 7, the wave-like portion 40 is formed by combining a plurality of valleys and peaks that form a straight line. In FIG. 8, a wave-like member 41 having a saw blade shape is formed. Further, in FIG. 9, a wave-like member 42 having a saw blade shape opposite to that in FIG. 8 (the front and rear along the vehicle body longitudinal direction is reversed) is formed. In FIG. 10, a wave-like portion 43 is formed by combining a plurality of convex arcs on the outside.

  7 to 10, each of the wavy portions 40, 41, 42, 43 is set such that the depth of the valley is deeper on the front side of the front side member 1 and shallower as it approaches the rear side. The interval between the ridges and the valleys or the interval between the ridges and the ridges is set shorter on the front side of the front side member 1 and longer as it approaches the rear side.

  In the case of FIGS. 7 to 10 as well, the same effect as that of the first embodiment can be obtained.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, each of the above embodiments is only an example of the present invention, and the present invention is not limited only to the configuration of each of the above embodiments. . Needless to say, changes in design and the like within the scope of the present invention are included in the present invention.

  For example, the peak portion of the wave-like portion may not protrude from the outer surface of the vertical wall 4A of the front side member inner 2 or the vertical wall 7A of the front side member outer 3, and may protrude outward from the outer surface.

1 is an external perspective view of a front side member according to Embodiment 1. FIG. It is sectional drawing along the SA-SA line of FIG. It is a figure which shows a mode that the front side member was compressively deformed by the bellows shape. 6 is an external perspective view of a front side member according to Embodiment 2. FIG. FIG. 10 is an external perspective view of a front side member according to a third embodiment. FIG. 10 is an external perspective view of a front side member according to a fourth embodiment. It is a figure which shows the modification of the wavy part by Example 5. FIG. It is a figure which shows the other modification of the wavelike part by Example 5. FIG. It is a figure which shows the further another modification of the wavelike part by Example 5. FIG. It is a figure which shows the wavelike part by Example 5, and shows another modification.

Explanation of symbols

1 Front Side Member 2 Front Side Member Inner 3 Front Side Member Outer 4A, 7A Vertical Wall 4B Upper Wall 4C Lower Wall 10, 11 Bead 10A, 10B, 10C Valley 10D, 10E Mountain 11A, 11B, 11C Valley 11D, 11E Yamabe 20,21 Bead 30,31 Bead

Claims (2)

A front side member having a rectangular closed cross section with a ridge line in the longitudinal direction of the vehicle body is disposed,
A plurality of wavy beads extending continuously in the longitudinal direction of the vehicle body without contacting the ridge line from the front part to the rear part of the front side member are provided on two opposite surfaces of the front side member in the longitudinal direction of the vehicle body. Formed side by side ,
The bead has a front side member structure characterized in that the depth of the valley portion of the wave-like portion is deeper on the front side of the front side member and gradually becomes shallower toward the rear side . The bead is characterized in that the interval between the valleys and valleys of the wavy portion or the interval between the peaks and the peaks is short on the front side of the front side member, and gradually increases as it approaches the rear side. The front side member structure according to claim 1.

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