JP5820663B2 - Bumper structure for vehicles - Google Patents

Description

  The present invention relates to a vehicle bumper structure having a shock absorber at a front end portion of a body of a vehicle body.

  In general, a bumper for a vehicle such as a passenger car has a bumper face exposed on the surface of a vehicle body, and a bumper beam supported by a side member of the vehicle behind the bumper face. In this type of vehicle bumper, generally, the bumper face is made of an elastic body such as a synthetic resin in order to mitigate an impact when the bumper of the traveling vehicle collides with a pedestrian's leg, and further, Measures such as interposing an impact absorber made of a foamed material such as polyurethane or polypropylene between the bumper beam and the like are taken.

  In order to protect the pedestrian's legs using this shock absorber, it is preferable to reduce the rigidity of the shock absorber to a certain extent so that the reaction force at the time of collision hardly acts on the pedestrian. If it is lowered, the amount of collision energy absorbed against a rigid body such as a wall surface or a vehicle will be insufficient. On the other hand, if the impact absorber is increased in rigidity to increase the amount of collision energy absorbed, the initial load at the time of collision will increase, and the pedestrian's legs may not be sufficiently protected. Arise.

  Therefore, in Patent Document 1, the shock absorber is horizontally arranged in two upper and lower stages with respect to the concave portion opened to the rear of the vehicle body of the bumper face, and the rigidity of the lower shock absorber is set to be higher than the rigidity of the upper shock absorber. A bumper structure for vehicles is also proposed. According to such a bumper structure, at the time of a collision with a pedestrian, the upper shock absorber absorbs the damage to the knee, and the lower shock absorber absorbs the foot while the shock absorber is absorbed. Can scoop up. In addition, the rigidity of the entire bumper can be ensured by the lower shock absorber in the event of a collision with a vehicle or the like. The lower-stage shock absorber has a plurality of longitudinal ribs extending in the longitudinal direction of the vehicle body and lateral ribs extending in the vehicle width direction in a lattice shape so as to have predetermined rigidity and shock absorbing performance. It is arranged and configured.

JP 2010-111322 A

  When a pedestrian's leg collides with the front of the vehicle body, it is necessary to absorb impact energy and to raise the lower leg in order to protect the pedestrian's lower leg. However, the conventional lower-stage shock absorber does not have a sufficient function to rebound and raise the lower leg of the colliding pedestrian. For this reason, the conventional lower shock absorber may not be able to protect the lower leg of the pedestrian.

  This invention is made | formed in view of such a subject, and it aims at providing the bumper structure for vehicles provided with the impact absorber which can flip up the lower leg of the colliding pedestrian reliably.

In order to achieve the above object, a vehicle bumper structure according to the present invention includes a plurality of longitudinal ribs extending in the longitudinal direction of the vehicle body and standing at a predetermined interval in the lateral direction of the vehicle body, and the longitudinal direction of the vehicle body extending in the vehicle body width direction. A bumper structure for a vehicle in which a shock absorber in which a plurality of lateral ribs erected with a predetermined interval in a direction are arranged in a lattice shape is attached to a rigid member provided at a front end portion of a vehicle body, The shock absorber is formed by arranging a plurality of horizontal cell groups extending in the vehicle body width direction in a plurality of rows in which the cells defined by the longitudinal ribs and the lateral ribs extend continuously on both sides in the vehicle body width direction. , the vehicle width direction on both sides the central portion of the width direction of the vehicle body is supported movably is freely deformed in the vehicle longitudinal direction and the front side of the vehicle body is curved in a convex shape in plan view, the shock absorber body The center in the width direction moves in the front-rear direction with respect to the rigid member Is supported on the ability, the vehicle widthwise sides is characterized in that it is movable in the vehicle width direction with respect to the rigid member (claim 1).

  The shock absorber of the present invention includes a center of a long hole for attaching the shock absorber to the rigid member via the fastening means extending to the rear side of the vehicle width direction center portion in the vehicle body longitudinal direction, and both sides of the vehicle width direction. A pair of long hole side portions are provided on the rear side for extending the vehicle body width direction and attaching the shock absorber through fastening means.

  Further, according to the present invention, there is provided a lateral hole portion penetrating in the vertical direction between the lateral cell groups disposed adjacent to each other in the front-rear direction of the vehicle body in front of the pair of long hole side portions. It is characterized (Claim 3).

  Further, the present invention is characterized in that a central hole portion penetrating in the vertical direction is provided between the horizontal cell groups disposed adjacent to each other in the longitudinal direction of the vehicle body in front of the center of the long hole. Item 4).

  Further, according to the present invention, among the horizontal cell groups disposed on the rear side of the vehicle body, the horizontal cell group that connects between the central hole portion and the horizontal side hole portion is formed in an arch shape in which the front side of the vehicle body is curved in a convex shape. (Claim 5).

  As described above, according to the bumper structure for a vehicle according to the present invention, it is possible to provide a bumper structure for a vehicle having an impact absorber capable of jumping up the lower leg of a pedestrian that has collided. it can.

The principal part top view of the lower stage side shock absorber of the bumper structure for vehicles concerning one embodiment of this invention is shown. The principal part sectional view of the bumper structure for vehicles of the present invention is shown. The schematic partial perspective view of the lower stage side shock absorber concerning this invention is shown. It is an operation explanatory view for explaining a deformation of the impact stage side impact absorber when an impact load is applied to the impact absorber, and FIG. 9 (a) shows the center part in the vehicle width direction of the lower stage impact absorber. FIG. 4B shows the case where the impact load acts on the outer side portion of the lower-stage side impact absorber in the vehicle body width direction. The principal part top view of the lower stage side shock absorber concerning other embodiment of this invention is shown.

  Hereinafter, a preferred embodiment of a vehicle bumper structure of the present invention will be described with reference to FIGS. First, with reference to FIG. 2, the outline of the front part of the vehicle provided with the vehicle bumper structure will be described.

  An engine room 3 is provided at the front of the vehicle body 1, and a hood 5 that covers the engine room 3 is provided above the engine room 3. On the front side of the engine room 3, a grill 7 through which air passes is disposed, and a radiator core 9 is fixed to the rear of the grill 7 via a frame provided on the vehicle body 1. Bumper beams 11 extending in the vehicle body width direction are disposed below the grille 7 in front of the radiator core 9, and both ends of the bumper beam 11 in the vehicle body width direction are connected to and held by the vehicle body 1. A cross member 13 as a rigid member extending in the vehicle body width direction is disposed below the bumper beam 11, and both end portions of the cross member 13 in the vehicle width direction extend downward from the rear part of the bumper beam 11 (not shown). Z) is held through.

  In front of the bumper beam 11, a bumper face 15 that functions as a part of modeling of the front surface of the vehicle body is disposed. The bumper face 15 is made of an elastic material such as synthetic resin. The upper and lower portions of the bumper face 15 are curved and extend rearward, and are fixed to the bumper beam 11 and the cross member 13.

  On the inner side of the upper part of the bumper face 15, an upper stage shock absorber 20 extending in the vehicle body width direction is disposed. The upper-stage impact absorber 20 is formed of a foam having a predetermined foaming rate, such as a polyurethane foam or a polypropylene foam, and its rear surface is fixed to the bumper beam 11.

  Further, the lower portion of the bumper face 15 described above is disposed in front of the cross member 13. The bumper face 15 disposed in front of the bumper beam 11 and the bumper face 15 disposed in front of the cross member 13 are connected and integrated.

  In a lower space where the lower inner surface of the bumper face 15 and the cross member 13 face each other, a lower-stage impact absorber 30 extending in the vehicle body width direction is provided. The lower-stage impact absorber 30 is made of, for example, an injection-molded product using a thermoplastic resin such as polypropylene or PPO resin, and is supported in a state where its rear part is in contact with the front part of the cross member 13. . In addition, the attachment method to the cross member 13 of the lower stage side shock absorber 30 is mentioned later.

  Next, the lower shock absorber 30 will be described with reference to FIGS. 1 and 3. As shown in FIG. 1, the lower-stage impact absorber 30 includes a plurality of longitudinal ribs 31 that extend in the longitudinal direction of the vehicle body and stand up at a predetermined interval in the vehicle body width direction, and extend in the vehicle body width direction. A plurality of lateral ribs 33 erected with a predetermined interval in the direction are arranged in a lattice shape to constitute a main part. The ribs 31 and 33 are arranged in a lattice pattern, whereby a plurality of shock absorbing cells 35 are defined inside the lower shock absorber 30. These cells 35 form a horizontal cell group 37 extending continuously on both sides in the vehicle body width direction, and the horizontal cell groups 37 are arranged in two rows in the vehicle body longitudinal direction. Hereinafter, the horizontal cell group disposed on the front side of the vehicle body is referred to as the front side of the horizontal cell group 38, and the horizontal cell group disposed on the rear side of the vehicle body is referred to as the rear side of the horizontal cell group 40.

  In the front side of the horizontal cell group 38, a central portion 38a in the vehicle body width direction is integrally connected to a central portion 40a in the rear side of the horizontal cell group 40, and outer portions 38b connected to both ends of the central portion 38a extend outward in the vehicle width direction. Yes. The horizontal ribs 33 of the cells 35 constituting the front side of the horizontal cell group 38 are curved and formed in an arcuate shape having a convex front side along the front surface shape of the bumper face 15.

  The lateral cell group rear 40 is curved and formed in an arcuate shape in which the central portion 40a in the vehicle body width direction has a smaller curvature than the central portion 38a of the lateral cell group front 38 and is convex toward the front of the vehicle body. Further, the outer portion 40b extending outward in the vehicle body width direction after the lateral cell group 40 is connected to the outer portion 38b of the front side of the horizontal cell group 38 via a connecting portion 40c extending from the center portion 40a to the outer side 38b of the front side of the horizontal cell group 38. Are connected together. The rear end of the connecting portion 40c is connected to one outer end of the central portion 40a, and the front side of the connecting portion 40c extends obliquely outward and is connected to the outer portion 40b.

  As shown in FIGS. 1 and 3, a central mounting portion 41 extending rearward is provided on the rear side of the center portion 40 a of the center portion 40 a of the rear cell group 40, as shown in FIGS. 1 and 3. A pair of lateral attachment portions 42 extending rearward are provided at both ends of the portion 40a. The center mounting portion 41 is provided with a long hole center 41a extending in the front-rear direction and penetrating in the up-down direction. The lateral attachment portion 42 is provided with a long hole side portion 42a extending in the vehicle body width direction and penetrating in the vertical direction. Fastening means such as bolts are inserted into the long holes 41a and 42a, and the lower shock absorber 30 is movably attached to the cross member 13 (see FIG. 2). Details of the movement of the lower side shock absorber 30 with respect to the cross member 13 will be described later.

  A pair of lateral hole portions 44 penetrating in the vertical direction are provided between the front side lateral cell group 38 and the rear side lateral cell group 40 in front of the pair of long hole side portions 42a. The lateral hole 44 is formed in a triangular shape in plan view, the rear surface of the front side of the horizontal cell group 38 is a bottom side 44a, the front surface of the central portion 40a of the rear side of the horizontal cell group 40 is an oblique side 44b on one side, and the horizontal cell group The front surface of the connecting portion 40c of the rear 40 is formed as the oblique side 44c on the other side.

  Next, an operation when an impact load directed to the rear side acts on the front surface of the lower-stage impact absorber 30 will be described with reference to FIGS. 1, 4A, and 4B. First, the case where an impact load is applied to the vicinity of the center of the lower side impact absorber 30 in the vehicle width direction will be described. When an impact load Fa in the rearward direction acts near the center of the lower side shock absorber 30 in the vehicle body width direction, as shown in the lower side shock absorber 30 ′ of FIG. The central portion 38a of the front cell 38 and the central portion 40a of the rear side of the horizontal cell group 40 are bent backward with the bolts inserted through the pair of long hole side portions 42a as fulcrums, and the outer side portion 38b and the horizontal side of the front side of the horizontal cell group 38 The outer portion 40b of the rear cell group 40 moves outward. That is, the entire central portion 38a of the front side of the horizontal cell group 38 and the central portion 40a of the rear side of the horizontal cell group 40 are bent backward.

  For this reason, since stress is distributed to each center part 38a, 40a of the horizontal cell group front 38 and the horizontal cell group back 40, the intensity | strength and rigidity of the lower stage side shock absorber 30 are securable. In addition, since the entire central portions 38a and 40a of the front side cell group 38 and the rear side cell group 40 are bent, the central portions 38a and 40a can be bent within the elastic deformation range of the central portions 38a and 40a. . Therefore, it is possible to prevent the cells 35 constituting the front side cell group 38 and the rear side cell group 40 from being crushed, and to surely generate a reaction force against the impact load Fa and to jump up the lower leg of the colliding pedestrian. Can do. Moreover, since the long hole center 41a shown in FIG. 1 extends in the front-rear direction, the long hole center 41a extends in the same direction as the bending direction of the central portions 38a, 40a. For this reason, the stroke of the deformation when the central portions 38a and 40a are bent and deformed can be increased, and the reaction force can be further increased. For this reason, it is possible to more reliably raise the lower leg of the colliding pedestrian.

  Next, the case where the impact load Fb is applied to the outer portion of the lower-stage side shock absorber 30 in the vehicle width direction will be described. When an impact load Fb in the rearward direction acts on the outer portion of the lower-stage side shock absorber 30 in the vehicle body width direction, as shown in the lower-stage side shock absorber 30 ′ of FIG. The outer portion 38b of the front side of the horizontal cell group 38 and the outer side portion 40b of the rear side of the horizontal cell group 40 are bent rearward with the bolt inserted into the bolt 42a as a fulcrum, and the center portion in the vehicle body width direction of the lower side shock absorber 30 is a long hole. It moves to the front side with respect to the bolt inserted through the center 41a. Then, with this bolt as a fulcrum, the entire central portion 38a and outer portion 38b of the front side of the horizontal cell group 38 are further bent rearward and moved outward. That is, when the impact load Fb acts on the outer portion of the lower-stage side impact absorber 30 in the vehicle body width direction, the outer portion 40b of the rear side of the horizontal cell group 40 and the central portion 38a and the outer side portion 38b of the front side of the horizontal cell group 38 bend. .

  Accordingly, since stress is distributed to the central portion 38a and the outer portion 38b of the front side of the horizontal cell group 38 and the outer side portion 40b of the rear side of the horizontal cell group 40, the strength and rigidity of the lower shock absorber 30 can be ensured. . Moreover, since the substantially whole one side of the lower stage side shock absorber 30 except the center part 40b of the back side 40 is bent, it can be bent within these elastic deformation ranges. For this reason, crushing of the cell 35 can be prevented, a reaction force against the impact load Fb is surely generated, and the lower leg of the colliding pedestrian can be flipped up.

  Next, the case where the impact load Fc acts on the lower shock absorber 30 from the front of the long hole side portion 42a will be described with reference to FIG. When an impact load Fc acts from the front of the long hole side portion 42a, the central portion 38a of the front side of the horizontal cell group 38 disposed in front of the long hole side portion 42a bends toward the long hole side portion 42a. Accordingly, it is possible to prevent the drag force Fc from acting on the bolt inserted into the elongated hole side portion 42a through the connecting portion 40c by collapsing the cell 35 of the central portion 38a, thereby preventing the drag from being excessively increased. Can do.

  Further, by providing the side hole 44 in front of the long hole side 42a, as described above, when the impact load Fb acts on the outer side in the vehicle width direction of the lower stage side shock absorber 30, this load causes the lateral cell. Since the outer portions 38b and 40b of the front group 38 and the rear cell group rear 40 can be bent, it is possible to prevent excessive drag.

  In the lower shock absorber 30 of the above-described embodiment, the lateral hole 44 is provided in front of the pair of elongated holes 42a. However, as shown in FIG. A central hole 46 similar to the side hole 44 may be provided. The lower shock absorber 30 ′ provided with the central hole portion 46 is provided between the front side of the horizontal cell group 38 and the rear side of the horizontal cell group 40 in front of the long hole center 41a, and is formed in a substantially triangular shape in plan view. ing. Therefore, when an impact load Fd is applied from the front of the long hole center 41a, the central portion 38a of the front side of the horizontal cell group 38 disposed in front of the long hole center 41a bends toward the central hole 46 side, and the lower side The central portion 38a of the shock absorber 30 moves rearward along the long hole center 41a. For this reason, it is possible to more reliably prevent the cell 35 of the central portion 38a from being crushed, to surely generate a reaction force against the impact load Fd, and to jump up the lower leg of the colliding pedestrian, and excessive drag. Can be prevented in advance.

  Further, the lower stage side shock absorber 30 'has a center part 40a of the rear side 40 of the transverse cell group between the long hole center 41a and the long hole side parts 42a disposed on both sides in the vehicle body width direction. It is formed in an arch shape that is convexly curved to the side. Therefore, when an impact load directed to the rear side acts on the lower shock absorber 30 ′, the central portion 40a of the rear cell group 40 formed in the arch shape supports the impact load, and the front cell group 38 is A reaction force is generated by bending due to the impact load. Therefore, the lower leg of the colliding pedestrian can be flipped up.

1 Car body 13 Cross member (rigid member)
30, 30 'Lower side shock absorber (shock absorber)
31 Longitudinal rib 33 Lateral rib 35 Cell 37 Horizontal cell group 38 In front of horizontal cell group (horizontal cell group)
40 After horizontal cell group (horizontal cell group)
41a long hole center 42a long hole side part 44 side hole part (hole part)
46 Central hole (hole)

Claims (5)

A plurality of longitudinal ribs extending in the longitudinal direction of the vehicle body and standing at a predetermined interval in the vehicle body width direction, and a plurality of lateral ribs extending in the vehicle body width direction and standing at a predetermined interval in the vehicle body longitudinal direction And a bumper structure for a vehicle in which shock absorbers arranged in a grid pattern are attached to a rigid member provided at the front end of the vehicle body,
The shock absorber is formed by arranging a plurality of horizontal cell groups extending in a longitudinal direction of the vehicle body in which cells defined by the vertical ribs and the horizontal ribs extend on both sides in the vehicle body width direction.
Each lateral cell group is movably supported at the center in the width direction of the vehicle body, and both sides of the width direction of the vehicle body can be bent and deformed in the longitudinal direction of the vehicle body, and the front side of the vehicle body is convexly curved in plan view .
The shock absorber is supported so that the center in the vehicle width direction can move in the front-rear direction with respect to the rigid member, and both sides in the vehicle width direction are supported so as to be movable in the vehicle width direction with respect to the rigid member. A bumper structure for vehicles. The shock absorber extends in the longitudinal direction of the vehicle body at the rear side of the vehicle width direction center portion, and has a center of a long hole for attaching the shock absorber to the rigid member via fastening means, and rear portions of both sides of the vehicle width direction. The vehicular bumper structure according to claim 1, further comprising a pair of elongated hole side portions that extend in a vehicle body width direction and are attached to the shock absorber via fastening means. The lateral side hole portion penetrating in the vertical direction is provided between the lateral cell groups disposed adjacent to each other in the front-rear direction of the vehicle body in front of each of the pair of long hole side portions. The bumper structure for vehicles as described in 2. 4. The vehicle according to claim 3 , wherein a center hole portion penetrating in the vertical direction is provided between the horizontal cell groups disposed adjacent to each other in the longitudinal direction of the vehicle body in front of the center of the long hole. Bumper structure. Among the horizontal cell groups disposed on the rear side of the vehicle body, the horizontal cell group connecting the central hole portion and the horizontal hole portion is formed in an arch shape in which the front side of the vehicle body is curved in a convex shape. The bumper structure for vehicles according to claim 4 characterized by things.

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