JP2009073309A - Bumper structure for vehicles - Google Patents

Abstract

Provided is a vehicle bumper structure that can sufficiently reduce damage to a leg of a pedestrian and can ensure a degree of freedom in designing a vehicle body.
A bracket 40 having a central region supported by a radiator support panel 5 below a bumper beam 11 and a bumper face 15 covering the bumper beam 11 and the bracket 40 with an impact absorbing material 19 interposed therebetween are provided. The front cross member 9 facing the vehicle width direction end is provided with a crush box 20 whose top surfaces 23 and 33 are disposed facing the end of the bracket 40. In the event of a collision, the end of the bracket 40 is supported by the front cross member 9 via the crash box 20 to ensure rigidity, the initial impact load is absorbed by the shock absorber 19, and the lower leg Ka is supported by the bracket 40. It is received and scooped up smoothly, and the damage to the leg K can be reduced.
[Selection] Figure 5

Description

  The present invention relates to a vehicle bumper structure, and in particular, a bracket extending in the vehicle width direction below a bumper beam extending in the vehicle width direction, and a bumper that covers the front surface of the bumper beam and the front end surface of the bracket with an impact absorbing material interposed therebetween. The present invention relates to a vehicle bumper structure that includes a face and protects a pedestrian's legs in a collision with a pedestrian.

  In general, a vehicle bumper includes, for example, a bumper beam extending in the vehicle width direction at a front portion of the vehicle, and a bumper face that covers the bumper beam and forms an exterior of the bumper, and the bumper beam is supported by a body frame member such as a side member. The

  In particular, when a vehicle collides with a pedestrian's leg, the bumper face is made of a soft resin to reduce damage to the leg, and a foamed resin such as polyurethane or polypropylene is used between the bumper face and the bumper beam. 2. Description of the Related Art A vehicle bumper is known that includes a shock absorber made of a body.

  Here, in order to protect the pedestrian's legs using a shock absorber made of a resin foam, the rigidity of the shock absorber is lowered and the reaction force applied to the pedestrian in the event of a collision is minimized. It is preferable to reduce. However, if the rigidity is lowered, there is a concern that the impact energy absorption amount against a rigid body such as a wall surface or a vehicle is insufficient and sufficient impact relaxation cannot be obtained. On the other hand, if the impact energy absorption amount is increased by increasing the rigidity of the shock absorbing material, the initial impact load at the time of collision suddenly increases, making it extremely difficult to sufficiently protect the pedestrian's legs. Become.

  As a countermeasure, Patent Document 1 discloses a main bumper portion 103a that forms a front surface 102a of a bumper beam 102 extending in the vehicle width direction and an upper portion of a bumper face 103, as shown in FIG. A shock absorber 104 made of a resin foam such as polyurethane or polypropylene is interposed therebetween, and a lower bumper portion 103b forming a lower portion of the bumper face 103 is made of a synthetic resin having higher rigidity than the shock absorber 104. By fixing to the cross member 106 via the bracket 105, the rigidity of the lower part of the bumper 101 is enhanced, and the shock absorption to a rigid body such as a wall surface or a vehicle is enhanced.

  On the other hand, when the pedestrian collides with a leg part of the pedestrian, the impact absorbing material 104 is greatly plastically deformed through the main bumper part 103 a of the bumper face 103 to absorb the initial impact load, and the bracket 105 is supported by the bumper face 103. The lower leg part 103b of the leg contacts the lower leg part of the leg part. As a result, the impact of the pedestrian's leg near the knee is mitigated by the deformation of the shock absorber 104 having low rigidity, while the bracket 105 set with high rigidity is not greatly deformed, and the reaction force is reduced. It is given to the lower leg.

  As a result, the upper part of the leg part of the pedestrian is inclined to the front hood side of the vehicle body (not shown) due to the deformation of the shock absorber 104, and the lower leg part is scooped up by the reaction force of the bracket 105, so The load on the leg centering on the part is reduced.

JP 2000-264143 A

  According to the bumper structure of Patent Document 1 described above, when the bumper 101 collides with the pedestrian's leg, the initial impact of the impact absorbing material 104 having low rigidity on the vicinity of the knee of the pedestrian's leg is caused by the plastic deformation. Since the lower leg is scooped up by the bracket 105, the pedestrian can be quickly lifted onto the front hood to reduce the load on the leg to some extent.

  However, the bracket 105 extending to the lower part of the bumper 101 is secured by the cross member 106 in the coupling range with the cross member 106, but desired at both ends in the vehicle width direction not coupled to the cross member 106. Stiffness cannot be secured, and the bracket 105 is greatly deformed when it collides with the portion, making it difficult to scoop up the pedestrian's leg smoothly, and the load on the pedestrian's leg cannot be reduced. There is concern about damage to

  Moreover, since the range in which the rigidity of the bracket 105 is ensured is limited to the range in which the bracket 105 is coupled to the cross member 106, the shape of the bumper 101 is greatly limited, and the degree of freedom in designing the vehicle body is limited.

  Accordingly, an object of the present invention made in view of such a point is to provide a vehicle bumper structure capable of sufficiently reducing damage given to a pedestrian's legs and ensuring a degree of freedom in designing a vehicle body.

  The invention of the vehicle bumper structure according to claim 1, which achieves the above object, includes a bumper beam extending in a vehicle width direction and supported by a vehicle body skeleton member, and a central region below the bumper beam is a vehicle body skeleton member. In a vehicle bumper structure comprising: a bracket that is supported and extends in the vehicle width direction along the front surface of the subframe; and a bumper face that covers a front surface of the bumper beam and a front end surface portion of the bracket via an impact absorber. The top surface is disposed on the front surface of the subframe so as to face the end of the bracket, and includes an impact absorbing member that is crushed and deformed by an impact load from the front to absorb impact energy.

  According to the present invention, the bumper beam that supports the shock absorbing material extends below the bumper beam, and the central region is supported by the vehicle body skeleton member, so that it is crushed and deformed corresponding to the end portion in the vehicle width direction of the bracket that ensures rigidity. Since the impact absorbing member that absorbs impact energy is provided in the subframe, the end of the bracket is supported by the subframe via the impact absorbing member in the event of a collision, and the rigidity of the portion is ensured. As a result, even when the vehicle width direction end of the vehicle collides with a pedestrian's leg, the initial impact load is absorbed by the deformation of the shock absorber, and the lower leg is received by the bracket, so that it is sufficient for the lower leg. Reaction force is given. As a result, the upper part of the leg part of the pedestrian is inclined toward the front hood of the vehicle, and the lower leg part is smoothly scooped up by the bracket, so that damage to the leg part of the pedestrian can be reduced.

  In addition, since the rigidity of the bracket is ensured also at the end in the vehicle width direction, the restriction on the shape of the bumper is eased, the degree of freedom in designing the bumper and the degree of freedom in designing the vehicle body are increased.

  According to a second aspect of the present invention, in the vehicle bumper structure of the first aspect, the bracket regulates a load transmitting portion that transmits a load to a top surface of the shock absorbing member, and a direction in which the shock absorbing member is crushed and deformed. And an impact absorbing member guiding portion.

  According to the present invention, the load is transmitted from the load transmitting portion formed on the bracket to the top surface of the shock absorbing member. At this time, the direction of the collapsing deformation of the shock absorbing member is regulated by the shock absorbing member guiding portion, and the shock absorbing member is folded. The behavior such as bending is prevented, and the absorption of impact energy due to the crushing deformation of the stable impact absorbing member can be obtained. In addition, it is possible to predict in advance the deformation of the impact absorbing member, and it is possible to easily predict the impact absorbing characteristics of the impact absorbing member through experiments, simulations, etc., and the design of the impact absorbing member is facilitated. .

  According to a third aspect of the present invention, in the vehicle bumper structure according to the second aspect, the load transmitting portion is a rib-shaped lateral wall that extends in the vehicle width direction and faces the top surface of the shock absorbing member. The shock absorbing member guiding portion is a rib-like vertical wall extending in the front-rear direction so as to face the side surface of the shock absorbing member with a gap.

  This invention shows the concrete structure of a load transmission part and an impact-absorbing-member guidance | induction part, According to this invention, the rib-shaped side wall which extends a load-transmission part to a vehicle width direction and opposes the top surface of an impact-absorbing member In addition, the shock absorbing member guiding portion can be easily configured by a rib-like vertical wall extending in the front-rear direction so as to face the side surface of the shock absorbing member via a gap.

  According to a fourth aspect of the present invention, in the vehicle bumper structure according to the third aspect, the bracket includes an oblique reinforcing rib extending from the front end surface side toward the vertical wall at the end portion in the vehicle width direction. Features.

  According to the present invention, by providing the skew reinforcing ribs extending from the front end surface side toward the vertical wall at the end portion of the bracket, the impact load acting on the front end surface portion is directly transmitted via the skew reinforcing ribs. Is transmitted to the vertical wall and dispersedly transmitted to the shock absorbing member via the vertical wall to prevent deformation such as bending and bending at the end of the bracket. This ensures a reaction force from the bracket in the event of a collision.

  According to the present invention, the end of the bracket is supported by the subframe via the shock absorbing member in the event of a collision, and the rigidity of the portion is ensured. As a result, even when the vehicle width direction end of the vehicle collides with the pedestrian's leg, the initial impact load is absorbed by the shock absorber, and the lower leg is received by the bracket to provide a sufficient reaction force. It is possible to incline the upper part of the leg part toward the front hood of the vehicle, and to smoothly scoop up the lower leg part by the bracket, thereby reducing damage to the leg part of the pedestrian. In addition, since the rigidity of the bracket is ensured also at the end in the vehicle width direction, the restriction on the shape of the bumper is eased, the degree of freedom in designing the bumper and the degree of freedom in designing the vehicle body are increased.

  An embodiment of a vehicle bumper structure according to the present invention will be described with reference to FIGS. In each figure, the arrow F indicates the vehicle body front direction, the arrow OUT indicates the vehicle outer direction in the vehicle width direction, and the arrow UP indicates the upward direction.

  1 is a perspective view of a vehicle front portion showing a schematic structure of a vehicle bumper according to the present embodiment, FIG. 2 is a cross-sectional view taken along the line II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line II-II in FIG. 4 is an exploded perspective view showing an outline of a crash box which is an impact absorbing member, FIG. 5 is a perspective view showing a main part showing a mounting state of the bracket, and FIG. 6 is a plan view showing a main part showing a mounting state of the bracket. 2, 3, and 6, the imaginary line K schematically indicates the leg portion of the pedestrian, Ka indicates the lower leg portion, and H indicates the knee portion.

  As shown in FIGS. 1 and 2, the upper part of the engine room E disposed at the front part of the vehicle 1 is swingable in the vicinity of the rear end of the engine room E whose rear end forms a vehicle body body via a hinge mechanism. The front hood 2 supported by the front hood 2 is closed, and the front of the engine room E extends in the vehicle width direction along the front grill 3 extending along the front end of the front hood 2 and along the lower edge of the front grill 3. An existing bumper 10 is disposed.

  Further, as shown in FIG. 2, a radiator support panel 5 that holds the radiator 6 is disposed behind the front grill 3 and the bumper 10 so as to extend in the vehicle width direction. The radiator support panel 5 includes a radiator support upper panel 5a and a radiator support lower panel 5b that are formed in a frame shape extending in the vehicle width direction, and the front ends of left and right front side frames (not shown) whose both ends extend in the vehicle longitudinal direction. Combined with The left and right front frames and the radiator support panel 5 constitute a vehicle body skeleton member in which rigidity is ensured.

  The left and right side members 8 extending in the longitudinal direction of the vehicle body along the lower side of the left and right front side frames and the front side of the radiator support lower panel 5b extending in the vehicle width direction and connecting the front ends of the left and right side members 8 to each other. A sub-frame 7 having a cross member 9 is disposed. The sub-frame 7 has a rear end portion and an intermediate portion, etc., of the left and right side members 8 fastened to the left and right front side frames, respectively, and a suspension device for suspending and supporting the front wheels on the sub-frame 7 is disposed. Note that the suspension device and the like are not directly related to the present invention, and thus illustration and description thereof are omitted.

  As shown in FIGS. 1 to 3, the bumper 10 includes a bumper beam 11 made of a sheet metal extending in the vehicle width direction, a bumper face 15 made of a soft resin forming an exterior, and a bumper beam 11 interposed between the bumper beam 11 and the bumper face 15. A shock absorber 19, a crash box 20 that is an impact absorbing member disposed at each end of the front cross member 9, and a bracket 40 that extends in the vehicle width direction along the lower portion of the bumper face 15. .

  The bumper beam 11 includes a front surface 12 extending in the vehicle width direction, a top surface 13 bent rearward from the upper edge of the front surface 12 and having a flange 13a formed at the rear end edge, and a rear surface from the lower edge of the front surface 12. The lower surface 14 which is bent and has a flange 14a formed at the rear end edge is integrally formed and extends in the vehicle width direction with a substantially U-shaped cross section with the rear side open, and the left and right ends are respectively connected via brackets (not shown). Connected to the front end of the front side frame.

  The upper end of the bumper face 15 is fixed to a vehicle body member or the like by screws and brackets (not shown), the bumper face 15 extends in the vehicle width direction so as to face the front surface 12 of the bumper beam 11, and the vehicle width direction end portion curves backward. A main bumper portion 16 is formed, and a lower bumper portion 17 serving as an air dam portion is opposed to the front surface 9a of the front cross member 9 and extends in the vehicle width direction slightly behind the main bumper portion 16 on the vehicle body rear side. An end portion in the vehicle width direction is curved backward, and an opening 18 for introducing outside air into the engine room E is formed between the main bumper portion 16 and the lower bumper portion 17.

  An impact absorbing member 19 extending in the vehicle width direction is interposed between the front surface 12 of the bumper beam 11 and the main bumper portion 16 of the bumper face 15. The shock absorbing material 19 is formed of a resin foam having a predetermined foaming rate, such as polyurethane or polypropylene.

  The left and right crash boxes 20 have a symmetrical shape, and one of them will be described. The crash box 20 is composed of two sheet metal members, an upper box member 21 and a lower box member 31, as shown in an exploded perspective view in FIG. 4 and an assembled state in FIG.

  The upper box member 21 has a substantially rectangular plate-shaped upper surface 22 that extends in the front-rear direction, which is a predetermined crushing direction of the crash box 20, and gradually becomes wider as it moves from the front side to the rear side. The top surface 23 is bent downward along the front edge of the upper surface 22, and the lower side including the inner surface 24 and the outer surface 25 bent downward along the inner edge and the outer edge of the upper surface 22, respectively. The inner coupling flange 26 and the outer coupling flange 27 are bent along the lower end edges of the inner side surface 24 and the outer side surface 25 respectively. A plurality of concave crush beads 24a, 25a extending in the vertical direction perpendicular to the crushing direction are formed on the inner side surface 24 and the outer side surface 25 at intervals in the front-rear direction. A mounting portion 28 facing the front surface 9a of the front cross member 9 is bent at the rear end of the upper surface 22 on the base end side.

  On the other hand, the lower box member 31 has a substantially rectangular plate-like lower surface 32 that gradually increases in width as it moves from the front side to the rear side so as to face the upper surface 22 of the upper box member 21. A cross section in which the top surface 33 is bent upward along the inner side 34 and the outer side surface 35 that are bent upward along the inner edge and the outer edge of the lower surface 32, respectively. An inner coupling flange 36 and an outer coupling flange 38 that extend in the front-rear direction in a substantially U-shape and are opposed to the inner coupling flange 26 and the outer coupling flange 27 of the upper box member 21 respectively at the upper end edges of the inner side surface 34 and the outer side surface 35. A bend is formed. On the inner side surface 34 and the outer side surface 35, a plurality of concave crush beads 34a, 35a extending in the vertical direction are formed at intervals in the front-rear direction. A mounting portion 38 that is opposed to the front surface 9a of the front cross member 9 is bent at the rear end of the lower surface 32 on the base end side. The upper box member 21 and the lower box member 31 formed by these sheet metal members can be easily and inexpensively manufactured by pressing or the like.

  The upper box member 21 and the lower box member 31 are formed by welding the inner coupling flanges 26 and 36 and the outer coupling flanges 27 and 37 facing each other to form an upper surface 22, a lower surface 32, inner surfaces 24 and 34, The outer side surfaces 25 and 35 form a rectangular cylindrical crash box 20 that extends in the front-rear direction, which is the crushing direction. The crash box 20 has mounting portions 28 and 38 formed at the base end thereof attached to the front surface 9a at the end of the front cross member 9 by welding or bolting.

  In this way, the crash box 20 formed in a rectangular cylindrical shape has a resistance against an impact load acting on the top surfaces 23 and 33 from the front, so-called crushing rigidity is set higher than the rigidity of the shock absorber 19 formed of the resin foam. When a predetermined impact load is input to the top surfaces 23 and 33 from the front, the crash beads 24a and 34a formed on the inner side surfaces 24 and 34 and the crash beads 25a and 35a formed on the outer surfaces 25 and 35, respectively. In accordance with the crushing deformation, the crushing direction from the top surface 23, 33 side toward the rear base end side is followed by crushing deformation from the front side to the rear side to absorb the impact energy.

  Next, the bracket 40 will be described with reference to FIGS. 2 and 3, FIG. 5 showing a perspective view of a main part in an attached state, FIG. 6 showing a plan view of the main part, and FIG. 7 showing a cross section taken along line III-III in FIG. To do.

  The bracket 40 is an injection molded product formed of a thermoplastic resin such as polypropylene and can absorb shocks alone. The bracket 40 extends in the vehicle body width direction along the inner surface of the lower bumper portion 17 having the front end surface portion 41 formed on the bumper face 15. And the rear end of the upper surface portion 42 and the upper surface portion 42 are curved to the rear in a vehicle width direction and smoothly extend rearward from the upper end edge of the front end surface portion 41 along the lower surface of the radiator support lower panel 5b. The rear surface 43 extends in the vehicle width direction along the front surface 9 a of the front cross member 9, with the lower portion having the rear surface portion 43 extending downward from the edge being opened. Both ends of the bracket 40 protrude further outward in the vehicle width direction from the end portion of the front cross member 9, and the end portions of the front end surface portion 41, the upper surface portion 42, and the rear surface portion 43 are closed by the side end surface portion 44.

  A rectangular opening 45 into which the crush box 20 disposed on the front cross member 9 is inserted is formed in the rear surface portion 43. An inner vertical wall 46 and an outer vertical wall that project downward from the upper surface portion 42 across the opening 45 and extend in the front-rear direction between the rear surface portion 43 and the front end surface portion 41 and serve as a rib-shaped shock absorbing member guiding portion. Walls 47 are formed facing each other. In other words, as shown in FIGS. 6 and 7, the inner vertical wall 46 and the outer vertical wall 47 have a width in the vehicle width direction of the crush box 21, that is, from the tips 26a, 36a of the inner coupling flanges 26 and 36 to the outer coupling flange 27. The inner vertical wall 46 faces the inner side surfaces 24 and 34 of the crash box 20, while the outer vertical wall 47 faces the outer side surfaces 25 and 35.

  Between the inner vertical wall 46 and the outer vertical wall 47, a rib shape that protrudes downward from the upper surface portion 42 and extends in the vehicle width direction and abuts or approaches the top surfaces 23, 33 of the crash box 21. A horizontal wall 48 serving as a load transmitting portion is constructed.

  Further, an inner lower wall 49 that is bent and extended outward in the vehicle width direction along the lower end of the inner vertical wall 46 is formed as a shock absorbing member guiding portion. The inner lower wall 49 has a tip 49a facing the inner surface 34 of the lower box member 31 forming the crash box 20 via a gap, and an upper surface 49b facing the lower surface 36b of the inner coupling flange 36 via a gap.

  Similarly, an outer lower wall 50 that is bent and extended inward in the vehicle width direction along the lower end of the outer vertical wall 47 to serve as a shock absorbing member guiding portion is formed. The outer lower wall 50 has a tip 50a opposed to the outer surface 35 of the lower component 31 forming the crash box 20 via a gap, and the upper surface 50b opposed to the lower surface 37b of the outer lower wall 37 via a gap.

  Further, the bracket 40 extends downward in the front-rear direction between the rear surface portion 43 and the front end surface portion 41 and between the lateral wall 48 and the front end surface portion 41 so as to protrude downward from the upper surface portion 42 over the entire width. A plurality of vertical ribs 51a are provided. Furthermore, a horizontal rib 51b that intersects with the vertical rib 51a and extends in the vehicle width direction, and a skewed rib 51c that inclines in an oblique direction with respect to the longitudinal direction of the vehicle body and extends across the vertical rib 51a are provided. . In particular, at the end portion of the bracket 40 that is on the outer side in the vehicle width direction from the outer vertical wall 47, the inner surface shifts inward in the vehicle width direction toward the outer vertical wall 47 side as it shifts from the end range 41a of the front end surface portion 41 to the rear side. In this manner, a plurality of oblique reinforcing ribs 52 extending between the end range 41a of the front end surface portion 41 and the outer vertical wall 47 and the rear surface portion 43 are disposed so as to be inclined with respect to the longitudinal direction of the vehicle body. The

  The bracket 41 thus formed is inserted into the front surface of the front cross member 9 in a state where the top surfaces 23 and 33 of the crash box 20 attached to the end of the front cross member 9 are inserted from the opening 45 of the rear surface portion 43. As shown in FIG. 3, the center portion in the vehicle width direction of the upper surface portion 42 is attached to the lower surface of the radiator support lower panel 5b with bolts 55 or the like.

  In the state where the bracket 40 is attached to the radiator support lower panel 5b, as shown in FIGS. 6 and 7, the lateral wall 48 is in contact with or close to the top surfaces 23 and 33 of the crash box 20, and the upper surface portion 42 is The crush box 20 is opposed to the upper surface 22 via a gap, the inner vertical wall 46 is opposed to the inner side surfaces 24 and 34 via the gap, and the outer vertical wall 47 is opposed to the outer side surfaces 25 and 35 via the gap.

  Furthermore, the front end 49a of the inner lower wall 49 faces the inner side surface 34 via a gap, and the upper surface 49b faces the lower surface 36b of the inner coupling flange 36 via a gap. Further, the tip 50a of the outer lower wall 50 faces the outer surface 35 via a gap, and the upper surface 50b faces the lower surface 37b of the outer coupling flange 37 via a gap.

  Next, the operation of the vehicle bumper 10 in the present embodiment will be described.

  For example, when the leg K of the vehicle 1 collides with the leg K of the pedestrian as shown by the phantom line K 1 in FIG. 6, the vicinity of the knee H of the leg K is the main part of the bumper face 15. The central portion in the vehicle width direction of the shock absorber 19 that is in contact with the bumper portion 16 and is interposed between the main bumper portion 16 and the bumper beam 11 is mainly plastically deformed to absorb impact energy, particularly the initial impact load.

  On the other hand, the lower leg part Ka below the knee part H comes into contact with the lower bumper part 17 of the bumper face 15, and the lower leg part Ka is received by the plastic center of the bracket 40 being mainly plastically deformed. The bracket 40 is formed of a resin injection molded body having higher rigidity than the shock absorber 19 and the center in the vehicle width direction extends along the front side of the front surface 9a of the front cross member 9 and is attached to the radiator support lower panel 5b. As a result, the amount of deformation is suppressed when it is stiffened and supported by the radiator support lower panel 5b and the front surface 9a of the front cross member 9 and receives an impact. Therefore, the impact load received by the bracket 40 can be received by the radiator support lower panel 5b or further by the front chrome member 9, and a sufficient reaction force can be applied to the lower leg Ka of the pedestrian.

  As a result, the pedestrian's leg K is received near the knee H with plastic deformation of the shock absorber 19 and the upper part is inclined toward the front hood 2 of the vehicle 1, and the lower leg Ka is the bracket 40. Received and scooped up. Thereby, the bending angle given to the leg part K centering on the knee part H of a pedestrian can be made small, and the damage to the leg part K containing the knee part H can be reduced.

  Further, the reaction force by the bracket 40 to the crus Ka at the time of the collision and the shock absorption characteristics due to the rigidity and plastic deformation of the bracket 40 are the vertical rib 51a, the horizontal rib 51b and the diagonal reinforcement at the center in the vehicle width direction of the bracket 40. It can be easily set by increasing / decreasing the ribs 51c, and the damage to the pedestrian's leg K can be more efficiently reduced by appropriately changing according to the required impact characteristics that vary depending on the specifications of the vehicle 1 and the like.

  Further, as shown in FIG. 6, when the leg K is indicated by an imaginary line K <b> 2, when a vehicle width direction end of the vehicle 1, for example, a part outside the crash box 20 collides with the pedestrian's leg K, the leg The vicinity of the knee portion H of K is in contact with the main bumper portion 16 of the bumper face 15, and the vicinity of the end portion in the vehicle width direction of the shock absorber 19 interposed between the main bumper portion 16 and the bumper beam 11 is mainly plastically deformed. To absorb impact energy including initial impact load at the time of collision.

  On the other hand, the lower leg part Ka below the knee part H abuts on the lower bumper part 17 of the bumper face 15, and the lower leg part Ka is plastically deformed in the range of the end part in the vehicle width direction of the bracket 40 and the crush box 20 is crushed. By absorbing impact energy and receiving it.

  That is, the end portion of the bracket 40 in the vehicle width direction has an inner vertical wall 46 that extends from the front end surface portion 41 to the rear surface portion 43 and a horizontal wall 48 that extends from the outer vertical wall 47 to the top surface of the crash box 20. 23 and 33 are pressed against each other, and an impact load is input to the top surfaces 23 and 34 from the front. As a result, the crush beads 24a and 34a formed on the inner side surfaces 24 and 34 of the crash box 20 and the crush beads 25a and 35a formed on the outer side surfaces 25 and 35 are gradually crushed and deformed sequentially from the front side to the rear side. Then, the impact energy is absorbed, and the backward movement of the bracket 40 is regulated by the absorption of the impact energy.

  Here, when an impact load in a load direction that is unevenly distributed with respect to the crushing deformation direction of the crash box 20 is input, the inner vertical wall 46, the outer vertical wall 47, the upper surface portion 43, the inner lower wall 49, and the outer lower portion of the bracket 40 are input. The behavior direction is regulated by the wall 50 or the like, and the crash box 20 is crushed and deformed in order from the top surfaces 23 and 33 side to absorb and receive the impact energy. That is, the inner side surfaces 24 and 34 of the crash box 20 are in contact with the inner vertical wall 46 or the inner side surface 34 is in contact with the tip 49a of the inner lower wall 49, and the crash box 20 is excessively bent and deformed inward in the vehicle width direction. Behavior is prevented. Similarly, when the outer surfaces 25 and 35 of the crash box 20 are in contact with the outer vertical wall 47 or the outer surface 35 is in contact with the tip 50a of the outer lower wall 50, the crash box 20 is bent excessively outward in the vehicle width direction. Behavior is prevented. Further, when the upper surface 22 of the crash box 20 abuts against the upper surface portion 43 of the bracket 40, the behavior of excessive bending deformation to the upper side of the crash box 20 is prevented. Similarly, the lower surface 36b of the inner coupling flange 36 and the lower surface 36b of the outer coupling flange 37 of the crash box 20 abut against the upper surface 49b of the inner lower flange 49 and the upper surface 50b of the outer lower flange 50, respectively. The behavior of bending downward is prevented.

  Therefore, when the crush box 20 is crushed and deformed, the crush box 20 is prevented from bending excessively in the left and right and up and down directions, and the base surface side from the top surfaces 23 and 33 along the predetermined crush deformation direction. Then, the shock energy is stably crushed and deformed sequentially from the front to stably absorb the impact energy.

  Further, the bracket 40 extends obliquely with respect to the longitudinal direction of the vehicle body on the outer side in the vehicle width direction from the outer vertical wall 47 and is disposed from the end range 41a of the front end surface portion 41 toward the outer vertical wall 47 side. The oblique reinforcing rib 52 transmits the impact load from the front acting on the end region 41 a of the front end surface 41 directly to the outer vertical wall 47, and the outer vertical wall 47 faces the outer surface 25 of the crush box 20 facing the outer vertical wall 47. Further, the distal end 50a of the outer lower wall 50 is received by the opposing outer surface 35, and the deformation of the end portion of the bracket 40 is prevented, so that the leg portion K of the pedestrian, particularly the lower leg portion Ka, can be reliably received. it can.

  As a result, the pedestrian's leg K is received near the knee H with plastic deformation of the shock absorber 19, the upper part is inclined toward the front hood 2 of the vehicle 1, and the lower leg Ka is the bracket. It is possible to reduce damage to the leg K including the knee H by reducing the bending angle applied to the leg K centered on the pedestrian's knee H by being received by 40 and scooped up.

  Further, the reaction force by the bracket 40 to the crus Ka at the time of the collision and the shock absorption characteristics due to the rigidity and deformation of the bracket 40 are adjusted by the shape and thickness of the crash box 20, the slant reinforcement rib 52, etc. By appropriately changing according to the required impact characteristics that vary depending on the specifications of the vehicle 1 and the like, the impact characteristics can be appropriately set, and damage to the pedestrian's leg K can be reduced more efficiently.

  On the other hand, when the central portion in the vehicle width direction of the bumper 10 collides with a rigid body such as a wall surface or a vehicle, the central portion in the vehicle width direction extends along the front side of the front surface 9a of the front cross member 9 and the radiator support lower panel. The bracket 40 is attached to 5b, and is firmly supported and supported by the radiator support lower panel 5b and the front surface 9a of the front cross member 9, and is reliably received at the center in the vehicle width direction of the bracket 40 made of a resin injection molded body having high rigidity.

  Further, when the vicinity of the vehicle width direction end of the bumper 10 collides with a wall or a rigid body such as a vehicle, plastic deformation near the vehicle width direction end of the bracket 40 and the inner vertical wall 46, the outer vertical wall 47 of the bracket 40, The behavior direction is regulated by the upper surface portion 43, the inner lower wall 49, the outer lower wall 50, and the like, and the crash box 20 is crushed and deformed in order from the top surfaces 23 and 33 to efficiently absorb and receive impact energy.

  Therefore, according to the present embodiment, the central region is supported by the radiator support panel 5 below the bumper beam 11 that supports the shock absorber 19 and corresponds to the end of the bracket 40 that extends in the vehicle width direction. Since the crash box 20 is supported by the frame 7 and is crushed and deformed by an impact load acting on the top surfaces 23 and 33 from the front and absorbs the impact energy, the end of the bracket 40 in the event of a collision causes the crash box 20 to The rigidity of the end portion of the bracket 40 is ensured by being supported by the sub-frame 7, so that even when the vehicle width direction end portion of the vehicle 10 collides with the leg portion K of the pedestrian, the shock absorber 19 can The impact load is absorbed, and the lower leg Ka is received by the bracket 40 so that a sufficient reaction force can be applied to the lower leg Ka. The upper part of the leg part K of the pedestrian is inclined toward the front hood 2 side of the vehicle, and the lower leg Ka is smoothly scooped up by the bracket 40 so that damage to the leg part K of the pedestrian can be reduced. The obstacle value can be greatly reduced.

  In addition, since the rigidity of the bracket 40 is ensured also at the end portion in the vehicle width direction, restrictions on the formation of the bumper 10 are relaxed, and the degree of freedom in designing the bumper 10 is increased and the degree of freedom in designing the vehicle body is also increased.

  Furthermore, the crushing deformation direction of the crush box 20 is restricted, the behavior of the crush box 20 is prevented from being bent, and the crush box 20 can be crushed and deformed in a preset direction. The shock absorption characteristics of the crash box 20 can be predicted in advance through experiments, simulations, and the like, and the design of the crash box 20 becomes easy.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above embodiment, the shock absorber 19 interposed between the bumper beam 11 and the main bumper portion 16 of the bumper face 15 is formed of a resin foam such as polyurethane or polypropylene. It can also be formed by a body or the like.

  Further, FIG. 8 shows an outline, and parts corresponding to those in FIG. 4 are denoted by the same reference numerals and detailed description thereof is omitted, but the top surface 22 and the lower box member 31 formed on the upper box member 21 of the crash box 20. The top surface 33 may be extended and the top surface coupling flanges 29 and 39 may be formed and coupled to each other by the top surface coupling flanges 29 and 39.

  Furthermore, in the above embodiment, the crash box 20 is formed in a cylindrical shape having a rectangular cross section. However, the crush box 20 is not limited to the rectangular cross section, and is continuous from the top surface to the base end side in another polygonal cross sectional shape and has a crushing deformation direction. It can also be formed into a polygonal cylindrical body in which crush beads extending perpendicularly are formed.

It is a perspective view of the vehicle front part which shows the schematic structure of the bumper for vehicles which concerns on this Embodiment. It is the II sectional view taken on the line of FIG. It is the II-II sectional view taken on the line of FIG. It is a disassembled perspective view which shows the outline | summary of a crash box. It is a principal part perspective view which shows the attachment state of a bracket. It is a principal part top view which shows the attachment state of a bracket. It is the III-III sectional view taken on the line of FIG. It is a perspective view which shows another crash box. It is a figure which shows schematic structure of the conventional vehicle bumper.

Explanation of symbols

1 Vehicle 5 Radiator support panel (body frame)
7 Subframe 8 Side member 9 Front cross member 9a Front face 10 Bumper 11 Bumper beam 12 Front face 15 Bumper face 19 Shock absorber 20 Crash box (shock absorbing member)
21 Upper box member 23 Top surface 24 Inner side surface (side surface)
25 Outside (side)
31 Lower box member 33 Top surface 34 Inner side surface (side surface)
35 Outside (side)
40 Bracket 41 Front end surface portion 42 Upper surface portion 43 Rear surface portion 44 End surface portion 46 Inner vertical wall (impact absorbing member guiding portion)
47 Outside vertical wall (impact absorbing member guiding part)
48 Side wall (load transmission part)
49 Inner lower wall (impact absorbing member guiding part)
50 Outer lower wall (impact absorbing member guiding part)
52 Skew reinforcement rib

Claims (4)

A bumper beam extending in the vehicle width direction and supported by the vehicle body frame member; and a bracket extending in the vehicle width direction along the front surface of the subframe with the central region supported by the vehicle body frame member below the bumper beam. In the vehicle bumper structure comprising a bumper face that covers the front surface of the bumper beam and the front end surface of the bracket via an impact absorbing material,
A vehicular bumper comprising a shock absorbing member that has a top surface opposed to an end of the bracket and is disposed on the front surface of the sub-frame and that is crushed and deformed by a shock load from the front to absorb shock energy. Construction. The bracket is
A load transmitting portion for transmitting a load to the top surface of the shock absorbing member;
An impact absorbing member guiding portion for regulating the direction of deformation of the impact absorbing member;
The vehicle bumper structure according to claim 1, further comprising: The load transmission part is
A rib-like lateral wall extending in the vehicle width direction and facing the top surface of the shock absorbing member,
The shock absorbing member guiding portion is
The vehicular bumper structure according to claim 2, wherein the bumper structure is a rib-like vertical wall facing the side surface of the shock absorbing member with a gap therebetween and extending in the front-rear direction. The bracket is
The vehicular bumper structure according to claim 3, further comprising a diagonal reinforcing rib extending from the front end surface side toward the vertical wall at an end in the vehicle width direction.

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