JP5249723B2 - Bumper structure for vehicles - Google Patents

Description

  The present invention relates to a vehicle bumper structure in which a shock absorber is provided on a bumper face.

  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. Here, in this type of vehicle bumper, generally, the bumper face is made of an elastic body such as a synthetic resin in order to reduce the impact when the bumper of the traveling vehicle collides with the pedestrian's leg, Countermeasures such as interposing an impact absorber made of a foamed material such as polyurethane or polypropylene between the bumper face and the bumper beam are taken.

  By the way, in order to protect the pedestrian's legs using the shock absorber, it is preferable to reduce the rigidity of the shock absorber to some extent and make it difficult for the reaction force at the time of collision to be applied to the pedestrian. If the rigidity is lowered, the collision energy absorption amount for a rigid body such as a wall surface or a vehicle is insufficient. On the other hand, if the impact absorber is increased in rigidity to increase the amount of collision energy absorption, the initial load at the time of collision will increase, and it will be difficult to sufficiently protect the pedestrian's legs. Become.

As a countermeasure, for example, Patent Document 1 discloses that a shock absorber is provided in two upper and lower stages with respect to a recess opening at the rear of a vehicle body of a bumper fascia (bumper face), and the rigidity of the lower shock absorber is set to the upper stage. A vehicular bumper structure that is set higher than the rigidity of the side shock absorber is disclosed. 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 absorbs the foot. Can scoop up. On the other hand, even in the event of a collision with a vehicle or the like, the rigidity of the entire bumper can be ensured by the shock absorber on the lower side. Further, Patent Document 1 discloses that a plurality of vertical ribs extending in the longitudinal direction of the vehicle body and horizontal ribs extending in the vehicle width direction are provided in order to give the lower-stage shock absorber a predetermined rigidity and shock absorption performance. Has been disclosed in which a shock absorber on the lower stage side is configured by arranging in a grid pattern on a base plate.
JP 2002-274298 A

  By the way, the vehicle bumper is an element that occupies an important role in determining the appearance of the vehicle body. Therefore, for example, when there is a design request for producing a sharp image of the appearance of the vehicle body, it may be necessary to reduce the volume in the front-rear direction at both ends of the bumper in the vehicle width direction.

  However, for example, in the shock absorber having the shock absorbing function by the ribs as described above, reducing the volume in the front-rear direction results in reducing the shock absorbing stroke by the ribs, so that accurate pedestrian protection can be achieved. There is a risk that it will be difficult to implement.

  The present invention has been made in view of the above circumstances, and provides a vehicle bumper structure capable of realizing sufficient pedestrian protection even when it is difficult to ensure a sufficient stroke for absorbing shock. For the purpose.

A bumper structure for a vehicle according to an aspect of the present invention includes a plurality of vertical ribs extending in the longitudinal direction of the vehicle body and a plurality of horizontal ribs extending in the vehicle width direction. A bumper structure for a vehicle, in which a shock absorber arranged on the vehicle body is interposed between a bumper face exposed on the surface of the vehicle body and a rigid member on the vehicle body skeleton side disposed inside the bumper face, In the front part of the longitudinal rib located in the vehicle width direction end region, an inclined part that inclines outward in the vehicle width direction from the rear to the front of the vehicle body is provided, and the front end part of the stiffening rib is provided in the middle of the inclined part. It connects, and the starting point of the said stiffening rib is made to correspond to the starting point of the said other inclination part adjacent to the vehicle width direction outer side, and it connects with the said longitudinal direction rib.

  According to the vehicle bumper structure of the present invention, sufficient pedestrian protection can be realized even when it is difficult to ensure a sufficient stroke for absorbing an impact.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is an exploded perspective view showing the main part of the front part of the vehicle body, FIG. 2 is a cross-sectional view of the main part of the bumper, and FIG. 4A is a cross-sectional view of an essential part taken along line IV-IV in FIG. 3, FIG. 4B is an explanatory view showing an example of the deformation state, and FIG. It is principal part sectional drawing in alignment with a line, (b) is explanatory drawing which shows an example of the deformation | transformation state, FIG. 6 (a) is principal part sectional drawing in alignment with the VI-VI line of FIG. FIG. 7A is an explanatory view showing an example of the deformed state, and FIG. 7A is a cross-sectional view of the main part along the line VII-VII in FIG. 4A, and FIGS. FIG. 8 is a plan view showing a main part of a modified example of the lower shock absorber.

  1 and 2, reference numeral 1 denotes a vehicle body such as an automobile. A frame-shaped radiator core support 5 for holding a radiator core (not shown) is disposed at the front portion of the vehicle body 1, and side members 5a located on the left and right of the radiator core support 5 are arranged in the front-rear direction of the vehicle body. It is fixed to a side beam 6 as a pair of extending body frames.

  Further, a bumper beam 7 extending in the vehicle width direction is disposed in front of the radiator core support 5, and left and right end portions of the bumper beam 7 are respectively held by left and right side members 5 a via brackets 8. Further, a cross member 10 as a rigid member extending in the vehicle width direction is disposed below the bumper beam 7, and the left and right ends of the cross member 10 are paired with a pair of connections extending downward from the rear portion of the bumper beam 7. Each is held via a member 11.

  Further, as shown in FIG. 2, a bumper face 15 that functions as a part of modeling of the front surface of the vehicle body is disposed in front of the bumper beam 7 and the cross member 10. The bumper face 15 is made of, for example, an elastic material such as synthetic resin. The upper and lower portions of the bumper face 15 are curved and extend rearward, and an upper surface mounting portion 15a and a lower surface mounting portion 15b are formed at the upper edge portion and the lower edge portion of the extended bumper face 15, respectively. Has been. In the present embodiment, the upper surface mounting portion 15 a of the bumper face 15 is fixed via a bracket 7 a fixed to the upper surface of the bumper beam 7, and the lower surface mounting portion 15 b is directly fixed to the lower surface of the cross member 10. Yes.

  Further, in the internal space of the bumper face 15, an upper side shock absorber 20 extending in the vehicle width direction is interposed in an upper space where the inner surface of the bumper face 15 and the bumper beam 7 face each other. A lower-stage impact absorber 21 extending in the vehicle width direction is interposed in a lower space where the inner surface of the member and the cross member 10 face each other.

  In the present embodiment, 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 front surface of the bumper beam 7.

  On the other hand, the lower-stage impact absorber 21 is made of an injection molded product using a thermoplastic resin such as polypropylene or PPO resin, and the cross member 10 is in contact with the front surface of the cross member 10. The upper surface is fixed through a plurality of brackets 10a protruding forward.

  As shown in FIGS. 1 to 3, the lower shock absorber 21 basically has a plurality of longitudinal ribs 25 extending in the front-rear direction of the vehicle body 1 and extending in the vehicle width direction. Thus, a plurality of lateral ribs 26 erected are arranged in a lattice pattern to constitute a main part. The ribs 25 and 26 are arranged in a lattice pattern, whereby a plurality of shock absorbing cells 30 are defined in the lower shock absorber 21.

  Here, for example, as shown in FIG. 3, each lateral rib 26 is curved in an arc shape along the front surface shape of the bumper face 15. Accordingly, in the vehicle width direction end region A of the lower-stage side shock absorber 21, the stroke that can be deformed in the vehicle front-rear direction for absorbing the shock is relatively shorter than the central region. In each vehicle width direction end region A of the lower shock absorber 21 formed in this way, the front portion of the longitudinal rib 25 is inclined outward in the vehicle width direction from the rear to the front of the vehicle body 1. (Hereinafter, the front region on the longitudinal rib 25 inclined in this way is also referred to as an inclined portion 25a). In the present embodiment, more specifically, each longitudinal rib 25 located in the vehicle width direction end region A starts from the intersection with the second-stage lateral rib 26 when viewed from the front, in the vehicle width direction. It is inclined outward. In this case, the inclination angle of the inclined portion 25a of each longitudinal rib 25 can be arbitrarily set. For example, as shown in FIG. 3, the inclined portion formed on one longitudinal rib 25 is provided. The leading end of the one vertical rib and the starting point of the inclined portion 25a of the other vertical rib 25 adjacent to the outside in the vehicle width direction of the one vertical rib may be located on the same straight line Lx along the front-rear direction of the vehicle body 1. desirable.

  Further, in the vehicle width direction end region A, a stiffening rib 31 is provided in each cell 30 defined by the inclined portion 25a of the longitudinal rib 25 and the lateral rib 26. As shown in FIG. 3, the stiffening rib 31 includes a middle portion of the inclined portion 25 a of the one longitudinal rib 25 positioned on the inner side in the vehicle width direction with respect to the cell 30, and the vehicle width of the one longitudinal rib 25. It arrange | positions in the position which connects the starting point of the inclination part 25a of the other vertical direction rib 25 adjacent to a direction outer side. And by arrange | positioning in this way, the stiffening rib 31 transmits also the collision load input into the inclination part 25a also to the adjacent longitudinal direction rib 25. FIG. In this case, in order to disperse the collision load efficiently, for example, as shown in FIG. 3, it is desirable that the stiffening rib 31 is disposed so as to be substantially orthogonal to the middle of the inclined portion 25a.

  In the present embodiment, the lower-stage impact absorber 21 integrally includes a stiffening plate that closes the opening of each cell 30 for the purpose of improving rigidity and the like. This stiffening plate can be constituted by a single member that uniformly closes either the upper opening or the lower opening of all the cells 30, for example. In this embodiment, the upper stiffening plate 33 and the lower stiffening plate 34 are divided to prevent the upper and lower rigidity from being biased and stabilize the behavior during crushing. Specifically, as shown in FIGS. 3, 4 (a), 5 (a), and 6 (a), the lower-stage impact absorber 21 is arranged for each cell row along the longitudinal direction of the vehicle body 1. When viewed, the number of the upper stiffening plate 33 that closes the upper opening of the cell 30 and the number of the lower stiffening plates 34 that close the lower opening of the cell 30 that is not closed by the upper stiffening plate 33 are the same. It is set to be the same number. That is, for example, as shown in FIG. 4A, when two cells 30 exist in the front-rear direction of the vehicle body 1, for example, the lower opening of the first cell 30 is the lower stiffening plate 34. The upper opening of the second cell 30 is closed by the upper stiffening plate 33. For example, as shown in FIG. 5A, when there are four cells 30 in the front-rear direction of the vehicle body 1, for example, the first and third cells 30 are blocked by the lower stiffener plate 34. Then, the second and fourth cells 30 are closed by the upper stiffening plate 33. For example, as shown in FIG. 6A, when there are three cells 30 in the front-rear direction of the vehicle body 1, for example, the first cell 30 is closed by the lower stiffener plate 34, The eyes and the third cell 30 are closed by the upper stiffening plate 33. In the example of FIG. 6A, for example, the upper and lower openings of the third cell 30 can both be opened.

  In such a configuration, for example, when the pedestrian's leg 50 collides with the vehicle width direction end region A of the bumper, the collided leg 50 deforms the bumper face 15 (see FIG. 7A). Then, when the impact from the leg portion 50 is transmitted to the lower shock absorber 21, first, as shown in FIG. 7B, first, the lateral rib 26 located at the front end of the lower shock absorber 21 is formed. Deformed backward. With this deformation, the inclined portion 25a of the longitudinal rib 25 located in the vicinity of the leg portion 50 has a component force F1 in a direction in which the inclined portion 25a is crushed (that is, in a direction along the extending direction of the inclined portion 25a). The component force F1) acts. The component force F1 is transmitted to the base side of the longitudinal rib 25 while being absorbed by the deformation of the inclined portion 25a, and a part thereof is branched and transmitted to the stiffening rib 31 along the way. While being absorbed by the deformation of 31, it is transmitted to the base side of another longitudinal rib 25 adjacent to the outside in the vehicle width direction. At the same time, a component force F2 having a component outside in the vehicle width direction acts on the inclined portion 25a, and the inclined portion 25a is deformed so as to be further inclined outward in the vehicle width direction from the connecting portion with the stiffening rib 31. . As a result, the lateral rib 26 located at the front end is deformed (recessed) rearward of the vehicle body 1 in a state of being largely biased outward in the vehicle width direction. Due to the deformation of the inclined portion 25a and the lateral rib 26, the leg portion 50 is guided outward in the vehicle width direction. By such an operation, the deformation of the lateral rib 26 proceeds further in a state of being biased outward in the vehicle width direction, and the inclined portion 25a adjacent to the outer side in the vehicle width direction is sequentially deformed relative to the currently deformed inclined portion 25a. As a result, the leg portion 50 is guided outward in the vehicle width direction (see FIG. 7C).

  In this way, at least a part of the longitudinal rib 25 arranged in the vehicle width direction end region A of the lower side shock absorber 21 is inclined outwardly in the vehicle width direction from the rear to the front of the vehicle body 1, and this longitudinal direction. By absorbing the impact from the pedestrian's leg 50 by the action of the inclined portion 25a and the like formed on the rib 25, the leg 50 is guided (released) outward in the vehicle width direction, so that the impact absorbing stroke is sufficiently increased. Even when it is difficult to ensure, accurate pedestrian protection can be realized.

  In this case, by adding a stiffening rib 31 connecting the middle of the inclined portion 25a and the starting point of another longitudinal rib 25 adjacent to the outside in the vehicle width direction to the lower-stage impact absorber 21, the longitudinal rib 25 Even when a part of the lower shock absorber 21 is inclined as the inclined portion 25a, the lower-stage shock absorber 21 can be given a predetermined rigidity, and a suitable shock absorbing performance can be realized. At the same time, the action of the stiffening rib 31 can disperse the collision to the other longitudinal ribs 25 located on the outer side in the vehicle width direction, thereby realizing a more suitable shock absorbing performance. Furthermore, by tuning the connecting position of the stiffening rib 31 with respect to the inclined portion 25a, the starting point (folding point) of deformation of the inclined portion 25a at the time of collision can be arbitrarily set.

  Further, by setting the tip of the inclined portion 25a and the starting point of the inclined portion 25a in the other longitudinal rib 25 adjacent to the outside in the vehicle width direction on the same straight line Lx along the front-rear direction of the vehicle body 1, the inclined portion 25a Can be distributed in a well-balanced manner on the base side of the adjacent longitudinal ribs 25.

  By the way, when the lower shock absorber 21 is deformed, the stiffening plates 33 and 34 are also deformed simultaneously with the deformation of the ribs 25, 26, 31 and the like. Here, in the present embodiment, the upper stiffening plate 33 and the lower stiffening plate 34 are provided in each cell row along the front-rear direction of the vehicle body 1 in order to ensure the rigidity balance in the vertical direction of the lower shock absorber 21. They are arranged alternately so as to have the same number. Therefore, for example, as shown in FIG. 4B, the lower shock absorber 21 is crushed rearward of the vehicle body 1 without being greatly bent or bent upward or downward during deformation. It is possible to accurately realize the shock absorbing performance. For example, as shown in FIGS. 5 (b) and 6 (b), the same effect can be obtained by disposing the upper stiffening plate 33 and the lower stiffening plate 34 in areas other than the vehicle width direction end region A. It is possible to play.

  Here, for example, as shown in FIG. 8, in the present embodiment having the stiffening rib 31, a part of the lateral rib 26 in the vehicle width direction end region A can be omitted. In this case, as shown in the drawing, the upper stiffening plate 33 or the lower stiffening plate 34 can be arranged in a cell unit defined by the stiffening rib 31 in the portion where the lateral rib 26 is omitted. It is.

An exploded perspective view showing the main part of the front part of the vehicle body Bumper main part sectional view The top view which shows the principal part of a lower stage side shock absorber (A) is principal part sectional drawing which follows the IV-IV line of FIG. 3, (b) is explanatory drawing which shows an example of the deformation | transformation state (A) is principal part sectional drawing in alignment with the VV line of FIG. 3, (b) is explanatory drawing which shows an example of the deformation | transformation state (A) is principal part sectional drawing which follows the VI-VI line of FIG. 3, (b) is explanatory drawing which shows an example of the deformation | transformation state (A) It is principal part sectional drawing in alignment with the VII-VII line of Fig.4 (a), (b), (c) is explanatory drawing which shows an example of the deformation | transformation state at the time of the collision The top view which shows the principal part of the modification of a lower stage side shock absorber

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Car body 5 ... Radiator core support 5a ... Side member 6 ... Side beam 7 ... Bumper beam 7a ... Bracket 8 ... Bracket 10 ... Cross member 10a ... Bracket 11 ... Connecting member 15 ... Bumper face 15a ... Upper surface attaching part 15b ... Lower surface attaching part DESCRIPTION OF SYMBOLS 20 ... Upper stage side shock absorber 21 ... Lower stage side shock absorber 25 ... Longitudinal rib 25a ... Inclined part 26 ... Lateral rib 30 ... Cell 31 ... Stiffening rib 33 ... Upper stiffening plate 34 ... Lower stiffening plate 50 ... Leg A ... Vehicle width direction end area

Claims (3)

A shock absorber in which a plurality of vertical ribs extending in the longitudinal direction of the vehicle body and standing and a plurality of lateral ribs extending in the vehicle width direction are arranged in a grid is provided on the surface of the vehicle body. A vehicle bumper structure interposed between a bumper face exposed to the vehicle body and a rigid member on the vehicle body skeleton side disposed inside the bumper face,
In the front portion of the longitudinal rib located in the vehicle width direction end region, an inclined portion that is inclined outward in the vehicle width direction from the rear to the front of the vehicle body is provided.
Connecting the front end of the stiffening rib in the middle of the inclined part,
A vehicular bumper structure characterized in that the starting point of the stiffening rib is connected to the vertical rib so as to coincide with the starting point of the other inclined portion adjacent to the outside in the vehicle width direction .   The tip of the inclined portion of the longitudinal rib and the starting point of the inclined portion of another longitudinal rib adjacent to the outside in the vehicle width direction are located on the same straight line along the vehicle body longitudinal direction. Item 2. A bumper structure for a vehicle according to Item 1.   The shock absorber includes a plurality of cells defined by the ribs in the longitudinal direction of the vehicle body, the upper stiffening plate closing the upper opening of the cell, and the upper stiffening plate not closed by the upper stiffening plate. The vehicular bumper structure according to claim 1 or 2, wherein the same number of lower stiffening plates for closing the lower openings of the cells are provided for each row along the longitudinal direction of the vehicle body.

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