JP2014051206A - Vehicular pedestrian protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently spring up a lower leg part of a pedestrian by return reaction force generated in a pedestrian protection bracket when a vehicle body front part collides with a leg part of the pedestrian.SOLUTION: In a pedestrian protection bracket 21, a surface load reception part 26 receiving an impact by a surface load is made to face the inside of an air dam 3c formed in a bumper fascia 3 lower part, a honeycomb reception part 27 of a honeycomb structure is continuously formed in a rear part thereof, and an arch-shaped reception part 28 of a honeycomb structure is continuously formed in a rear part thereof. When a vehicle body front part 1 collides with a leg part of a pedestrian, striking energy is applied to the surface load reception part 26 from a lower leg part A of the pedestrian, and a collision load thereof is transmitted to the honeycomb reception part 27 from the surface load reception part 26 as the surface load. Then, the honeycomb reception part 27 and the arch-shaped reception part 28 are flexurally deformed, and receive the collision load, and return reaction force generated at that time springs up the lower leg part of the pedestrian forward.

Description

  The present invention relates to a pedestrian protection device for a vehicle that is attached to a lower portion of a front portion of a vehicle body and protects a lower leg portion of a pedestrian at the time of a collision.

  In general, the front bumper of a vehicle, when it collides with a pedestrian's leg, absorbs the impact energy and jumps up the lower leg (near the calf) so that the upper body falls over the front hood. Personnel protection devices are provided.

  For example, a pedestrian protection device disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-76536) has a distal end portion of a pedestrian protection bracket (foot wiper member) in an air dam formed in a lower portion of a front bumper. The technology that was introduced is disclosed. This pedestrian protection bracket is designed to flip the lower leg of the pedestrian forward when the front part of the vehicle collides with the pedestrian's leg. However, the structure has a rigidity (drag) that greatly deforms when subjected to a certain large light impact load.

  That is, the pedestrian protection bracket disclosed in this document has a groove portion with an upper opening formed along the vehicle width direction at the front portion of the bracket forming the outer shape, and the protrusion of the vertical rib facing the groove portion. A predetermined gap is provided between the end portion and the forefront portion of the bracket that receives a collision load, a horizontal rib is formed on the front surface, and a pitch between the forefront portion and the horizontal rib in the first row is further increased. The pitch is narrower than the pitch between the horizontal ribs in the first row and the horizontal ribs in the second row.

  With such a structure, when the front part of the vehicle body collides with a pedestrian's leg part and the load at that time is applied to the pedestrian protection bracket, the foremost part tilts, and the protruding end passes through the foremost part. The part presses the lower leg of the pedestrian.

  According to the technique disclosed in this document, when the front part of the vehicle body collides with the leg part of the pedestrian, the front end surface of the pedestrian protection bracket is tilted and the projecting end part presses the lower leg part. Can be flipped up easily.

JP 2012-76536 A

  However, in the technique disclosed in the above-described document, each cell formed in the pedestrian protection bracket has a grid shape in which vertical ribs and horizontal ribs are arranged in a lattice pattern, so that the pedestrian's legs A load to which a collision load is applied from the portion is transmitted to the rear of the vehicle body mainly through the vertical ribs. For this reason, each rib is locally deformed, and local fracture is likely to occur due to stress concentration, the elastic region is reduced, and the efficiency of the return reaction force that attempts to kick the lower leg part is reduced accordingly. There is an inconvenience.

  In view of the above circumstances, the present invention makes it possible to efficiently receive the impact energy when the front part of the vehicle body collides with the pedestrian's leg part, and efficiently raises the lower leg part by the return reaction force. An object of the present invention is to provide a vehicle pedestrian protection device.

  The present invention is arranged at the lower part of the front part of the vehicle body, the rear part is fixed to the vehicle body frame, and when the front part of the vehicle body collides with the lower leg part of the pedestrian, the lower leg part receives the impact and returns. In the pedestrian protection device for vehicles provided with the pedestrian protection means that jumps up the lower leg by a reaction force, the pedestrian protection means extends in the vehicle width direction and receives an impact from the lower leg by a surface load. A surface load receiving portion; and a flexure load receiving portion that is provided at a rear portion of the surface load receiving portion and receives an impact from the surface load receiving portion by bending deformation. The side where the flex load receiving portion is adjacent is shared. It is characterized by being formed of a honeycomb structure having a plurality of hexagonal cells arranged in a row in the vehicle width direction.

  According to the present invention, the bending load receiving portion that receives and deforms the impact from the surface load receiving portion is formed of a honeycomb structure including a plurality of hexagonal cells arranged continuously along the surface load receiving portion. When the front part of the vehicle collides with the pedestrian's leg, the elastic load increases when the surface load receiving part receives the impact energy by the surface load (uniformly distributed load). Since the bending load receiving portion that receives the load is a honeycomb structure, it is possible to efficiently receive impact energy and generate a return reaction force by the bending of the honeycomb structure, and to efficiently jump the lower leg portion by this return reaction force. it can.

Sectional side view equivalent to II in Fig. 2 with the pedestrian protection bracket attached to the front of the vehicle Top perspective view of pedestrian protection bracket Bottom perspective view of pedestrian protection bracket Bottom view of pedestrian protection bracket Part V enlarged view of FIG. Characteristic diagram showing the relationship between drag and deformation stroke against collision load applied to pedestrian protection bracket

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 in FIG. 1 denotes a vehicle body front portion, and a front bumper 2 is disposed at the front end of the vehicle body front portion 1. The front bumper 2 includes a bumper fascia 3, a bumper beam 4, and an impact absorbing member 5. Further, a front grill 6 for guiding outside air from the front to the engine room is provided at the upper part of the front bumper 2, and the front end of an openable front hood (not shown) that closes the upper surface of the engine room is provided at the upper part. Are disposed.

  The bumper fascia 3 is made of synthetic resin such as polypropylene and functions as a part of the shaping of the front end face of the vehicle body, and the upper part thereof is fixed to an upper frame (not shown) of the radiator unit 11 described later. The lower part, that is, the lower part of the air dam 3c described later is connected to the pedestrian protection bracket 21 described later or the tip of the under cover that covers the lower surface of the engine room. The rear portion of the under cover is fixed to a suspension cross member that supports the front suspension.

  Further, a lower outside air inlet 3a is opened at the lower portion of the bumper fascia 3, and a condenser (not shown) of the air conditioner is mainly cooled by the outside air introduced from the lower outside air inlet 3a. Further, a main bumper portion 3b and an air dam 3c that rectifies the air flow in the lower front portion during traveling are formed so as to protrude above and below the lower external air inlet 3a of the bumper fascia 3. The main bumper portion 3b and the air dam 3c have a front end surface protruding forward by substantially the same amount in a side view, and are curved in a bow shape from the center in the width direction to the left and right.

  A radiator unit 11 is disposed behind the bumper fascia 3, that is, at the front of the engine room. The radiator unit 11 has a radiator panel (hereinafter abbreviated as “radio panel”) (not shown). The radiator panel 11 extends in the vehicle width direction on the left and right sides of the radiator panel, and above and below each of the radiator panel sides. And a radiator panel upper 11a serving as a vehicle body frame. The left and right radio panel sides (not shown) are connected to a pair of front side frames (not shown) extending in the longitudinal direction of the vehicle body.

  Further, the radiator unit 11 includes a radiator 11b and a condenser 11c of an air conditioner disposed in front of the radiator 11b, and these are fixed to the above-described radiator panel.

  The bumper beam 4 extends horizontally in the vehicle width direction in a state of being opposed to the rear of the main bumper portion 3b, and both end sides thereof are fixed to the front ends of a pair of front side frames (not shown). Has been. The back surface of the shock absorbing member 5 is fixed to the front surface of the bumper beam 4. The shock absorbing member 5 faces the main bumper portion 3b, and the front surface of the shock absorbing member 5 is opposed to the inner surface of the main bumper portion 3b at a predetermined interval. Further, the vehicle width direction is the shape of the main bumper portion 3b. Along the arc.

  The impact absorbing member 5 is made of a foamed material such as polyurethane foam or polypropylene foam, and the foaming rate is set to be relatively high. By setting the foaming rate of the impact absorbing member 5 high, the impact absorbing member 5 is plastically deformed when the front surface of the bumper collides with the leg part of the pedestrian, thereby reducing the impact applied to the leg part.

  Moreover, the front-end | tip part of the pedestrian protection bracket 21 as a pedestrian protection means faces in the bag-shaped air dam 3c formed in the lower part of the bumper fascia 3 and opening the back. This pedestrian protection bracket 21 lies on the front hood (not shown) by flipping up the lower leg of the pedestrian forward and upward when the vehicle body front 1 collides with the pedestrian. It is intended to make it. Therefore, the pedestrian protection bracket 21 has a rigidity (drag) that is not greatly deformed to the extent that the lower leg portion of the pedestrian collides, and is greatly deformed by a light collision load that does not deform the bumper beam 4. Incidentally, the pedestrian protection bracket 21 is a molded product made of a thermoplastic resin such as polypropylene.

  As shown in FIGS. 2 and 3, the outer surface portion 22 that forms the outer shape of the pedestrian protection bracket 21 is formed in a box shape that opens downward, and faces the inside of the air dam 3 c on the front surface. A load receiving surface 22a extending in the vehicle width direction along the front surface is formed, and a mounting portion 22b protruding rearward is formed at the rear portion. The mounting portion 22b is formed at predetermined intervals at the center in the vehicle width direction and at three positions on the left and right sides thereof, and the upper surface of the mounting portion 22b is bolted to the bottom of the radiator panel 11a.

  The pedestrian protection bracket 21 has offset receiving portions 24 formed on both sides in the vehicle width direction, and a center receiving portion 25 formed in the center. The offset receiving portion 24 is divided into two front and rear sides with the curved rib 24a interposed therebetween, and the oblique ribs 24b are disposed in the divided regions in a state of being directed in the direction of the left and right attachment portions 22b. . By directing the oblique ribs 24b toward the left and right attachment portions 22b, when the vicinity of the left and right end portions in the vehicle width direction of the front part of the vehicle body collides, the load at that time is transmitted in the direction of the attachment portion 22b and supported. it can.

  On the other hand, as shown in FIGS. 4 and 5, the center receiving portion 25 has a multi-stage (three-stage) structure including a surface load receiving portion 26, a honeycomb receiving portion 27, and an arched receiving portion 28 from the front. The honeycomb receiving portion 27 and the arched receiving portion 28 constitute a bending load receiving portion of the present invention.

  The surface load receiving portion 26 has the above-described load receiving surface 22a on the front surface, and the first beam-shaped rib 29 formed in the front portion of the load receiving surface 22a and the honeycomb receiving portion 27 and extending in the vehicle width direction. The vertical ribs 26a are formed at regular intervals. Further, angle ribs 26b are formed between the vertical ribs 26a.

  Each of the chevron ribs 26b is connected to the base part of the vertical rib 26a on the honeycomb receiving part 27 side, and the top part is connected to the inner surface of the load receiving surface 22a substantially at the center between the vertical ribs 26a. The entire surface load receiving portion 26 forms a truss structure. Further, the interval P1 between the vertical ribs 26a is set to about half the diameter of the lower leg A of the pedestrian (about 35 to 40 [mm] when the diameter of the lower leg A is 70 [mm]). Yes.

  Since this surface load receiving portion 26 is a truss structure and the interval between the vertical ribs 26a is about half of the diameter of the lower leg portion A, even if a load is applied to the load receiving surface 22a from the front, Only the vicinity does not bend locally, and the impact load is received by the deflection of the entire surface load receiving portion 26, so that the elastic region when the lower leg portion A collides can be increased.

  In the honeycomb receiving portion 27, a plurality of hexagonal cells 27a are continuously formed between the first beam-shaped rib 29 and the second beam-shaped rib 30 formed on the arch-shaped receiving portion 28 side. Furthermore, one top of each hexagonal cell 27a is connected to the base of the above-described vertical rib 26a, the left and right sides are shared and extend in the vehicle width direction, and are on the diagonal line of the above-mentioned vertex. The other apex is connected to the second beam-shaped rib 30. Accordingly, the entire honeycomb receiving portion 27 forms a honeycomb structure, and the interval between the apexes of each hexagonal cell 27a is P1.

  The collision load received by the central receiving portion 25 is transmitted to the apexes of the hexagonal cells 27a connected to the first beam-like ribs 29 of the honeycomb receiving portion 27, and the other apexes on the diagonal line through the left and right sides. To the second beam-like rib 30 side.

  As shown in FIGS. 2 to 4, the arch-shaped receiving portion 28 has an inverted U-shape that protrudes forward between the mounting portions 22 b with the three mounting portions 22 b described above as projecting ends. The first arch portion 32 is continuously provided, and the left and right attachment portions 22b and the offset receiving portion 24 and the end portion of the honeycomb receiving portion 27 are continuously provided via the second arch portion 33. Has been. Accordingly, the left and right second arch portions 33 and the two first arch portions 32 therebetween are formed in a continuous wave shape with the attachment portions 22b interposed therebetween.

  Further, each of the arch portions 32 and 33 is disposed on the outer periphery of the rear portion thereof, and faces the arch outer wall portion 34a forming a part of the outer surface portion 22 with a predetermined interval from the arch outer wall portion 34a. An arch inner wall portion 34b, and a plurality of hexagonal cells 35 share a side adjacent to each other between the wall portions 34a and 34b, and follow the shape between the wall portions 34a and 34b in the vehicle width direction. Has been extended. Each hexagonal cell 35 has a vertex on a side orthogonal to a side shared by the walls 34a and 34b. The arch-shaped receiving part 28 forms a corrugated arch structure as a whole by the arch parts 32 and 33, and the inside thereof has a honeycomb structure in which hexagonal cells 35 are continuously formed between the arch outer wall part 34a and the arch inner wall part 34b. It is a body.

  Furthermore, the central part 34c of the arch inner wall part 34b of each second arch part 33 is connected to the second beam-like rib 30 on the honeycomb receiving part 27 side. Further, due to the shape of the first and second arch portions 32 and 33, the arch inner wall portion 34b of each of the arch portions 32 and 33 and the second beam-shaped rib 30 have a substantially triangular shape with the mounting portion 22b side as a vertex. A hole 36 is formed. Therefore, the second beam-shaped rib 30 and the arch inner wall 34b are continuously provided in a closed loop on the inner periphery of the punch hole 36. By this punching hole part 36, the weight reduction of the pedestrian protection bracket 21 and the improvement of the bending property to the vehicle body front-back direction are realizable.

  Further, as shown in FIG. 2, rectangular long holes 37a and 37b are formed in the load receiving surface 22a located in the central receiving portion 25 and the upper surface of the outer surface portion 22 located in the surface load receiving portion 26. . By forming the long holes 37a and 37b on the front surface and the upper surface of the center receiving portion 25, the collision load from the front is directly transmitted to the vertical ribs 26a and the chevron ribs 26b.

  Next, the operation of the present embodiment having such a configuration will be described. When the bumper fascia 3 provided on the front bumper 2 of the front part 1 of the vehicle body collides with the pedestrian's leg, the upper leg (near the thigh) comes into contact with the main bumper 3b, and the lower leg (near the calf) A (see FIGS. 4 and 5) contacts an air dam 3c formed below the main bumper portion 3b.

  Then, the main bumper portion 3b in contact with the upper leg portion is deformed, and the impact absorbing member 5 interposed between the main bumper portion 3b and the bumper beam 4 is plastically deformed. Impact energy to the part is reduced.

  On the other hand, in the air dam 3c positioned below the main bumper portion 3b, a load receiving surface 22a formed on the front surface of the pedestrian protection bracket 21 is exposed, and the pressing load from the lower leg portion A is applied to the air dam 3c. To the load receiving surface 22a of the pedestrian protection bracket 21. When the central receiving portion 25 of the pedestrian protection bracket 21 comes into contact with the lower leg portion A, the central receiving portion 25 is divided into three parts, that is, a surface load receiving portion 26, a honeycomb receiving portion 27, and an arched receiving portion 28 from the front. The collision load from the lower leg portion A is first applied to the surface load receiving portion 26.

  As shown in FIG. 3 to FIG. 5, the surface load receiving portion 26 includes a vertical rib 26 a and a chevron rib 26 b formed between the vertical ribs 26 a in the vehicle width direction, and the entire structure is a truss structure. In addition, since the interval P1 between the vertical ribs 26a is set to about half the diameter of the lower leg portion A, even if a collision load from the lower leg portion A is applied to the surface load receiving portion 26, this surface The load receiving portion 26 is not locally bent, and the collision load is received by the bending of the entire surface load receiving portion 26 as shown by hatching in FIG. Therefore, the elastic region of the surface load receiving portion 26 can be increased.

  As a result, the entire surface load receiving portion 26 becomes a flexible rigid body, and the collision load from the surface load receiving portion 26 is applied to the honeycomb receiving portion 27 connected to the rear portion (surface load (equally distributed load)). ). The honeycomb receiving portion 27 has a honeycomb structure as a whole, and the apex on the side orthogonal to the side shared by the adjacent hexagonal cells 27a is the first beam-like rib 29 on the surface load receiving portion 26 side. And the second beam-shaped rib 30 on the arch-shaped receiving portion 28 side. For this reason, the collision load from the surface load receiving portion 26 is distributed and transmitted to each hexagonal cell 27 a via the apex continuously provided on the first beam-shaped rib 29.

  Then, the collision load distributed and inputted to the vertices of each hexagonal cell 27a passes through the sides shared by the adjacent hexagonal cells 27a from the left and right sides of this vertex as shown by arrows in FIG. The light is transmitted to the second beam-shaped rib 30 through the left and right sides collected at the upper vertex. Each of the beam-like cells 29 and 30 and the hexagonal cell 27a connected thereto are formed into a truss structure because the adjacent hexagonal cells 27a share a side, and are not easily crushed in the longitudinal direction of the vehicle body. It becomes a rigid body having Accordingly, the surface load receiving portion 26 and the honeycomb receiving portion 27 can transmit the collision load from the lower leg portion A to the arched receiving portion 28 without being crushed.

  As shown in FIG. 4, in the arch-shaped receiving portion 28, the central portion 34 c of the arch inner wall portion 34 b of the first arch portion 32 linking the three attachment portions 22 b is connected to the second beam-shaped rib 30. In addition, the left and right second arch portions 33 in the vehicle width direction are connected to the end portion of the honeycomb receiving portion 27. Further, each of the arch portions 32 and 33 is a rigid body having flexibility by a honeycomb structure in which a plurality of hexagonal cells 35 are continuously provided.

  Therefore, when a collision load from the honeycomb receiving portion 27 is applied to the arch-shaped receiving portion 28 from the central portion 34c as shown by an arrow in FIG. 5, the first arch portion 32 and the second arch portion 33 are crushed. Without bending.

  As a result, when the load receiving portion 26, the honeycomb receiving portion 27, and the arch-shaped receiving portion 28 described above are subjected to a collision load from the lower leg portion A, the central receiving portion 25 as a whole constituted by these members is not crushed. Bends to receive a collision load. Thereafter, the lower leg A is flipped forward by the return reaction force and return amount generated by the deflection of the central receiving portion 25 as a whole. As a result, the upper body of the pedestrian is laid down on the front hood to protect the pedestrian.

  FIG. 6 shows the measurement results of the drag (return reaction force) F and the deformation stroke S made of vocabulary when the pedestrian protection bracket 21 receives a collision load from the lower leg portion A of the pedestrian. The conventional pedestrian protection bracket 21 disclosed in Japanese Patent Application Laid-Open No. 2012-76536 has ribs formed in a grid pattern. Therefore, when a collision load is received from the lower leg portion A of the pedestrian, the collision load is locally generated. However, this deformation increases the deformation stroke S but reduces the return energy. As a result, it becomes difficult to obtain a sufficient return amount as indicated by the alternate long and short dash line in FIG.

  On the other hand, in the present embodiment, the collision load from the lower leg portion A is transmitted by the surface load receiving portion 26 to the honeycomb receiving portion 27 with a surface load (uniformly distributed load), and the honeycomb receiving portion 27 and its rear portion are transmitted. Since the arch-shaped receiving portion 28 is configured to receive a collision load by bending and deforming without being crushed, the initial drag is larger than the conventional drag as shown by the solid line in FIG. However, since the return energy is stored, the return amount increases. Therefore, the lower leg portion A can be efficiently flipped up accordingly.

  In addition, this invention is not restricted to embodiment mentioned above, For example, the offset receiving part 24 of the pedestrian protection bracket 21 is good also as a honeycomb structure. Moreover, the attachment part 22b may be two places, or four or more places. Furthermore, the vehicle body frame for fixing the pedestrian protection bracket 21 is not limited to the radiator panel 11a, but may be a cross member or the like provided at the lower part of the vehicle body.

DESCRIPTION OF SYMBOLS 1 ... Vehicle body front part 2 ... Front bumper 3 ... Bumper fascia 11a ... Radiant panel lower 21 ... Pedestrian protection bracket 22a ... Load receiving surface 22b ... Mounting part 24a ... Curved rib 24b ... Diagonal rib 25 ... Center receiving part 26 ... Surface load receiving part 26a ... vertical ribs 27 ... honeycomb receiving portions 27a, 35 ... hexagonal cells 28 ... arched receiving portions 29 ... first beam-like ribs 30 ... second beam-like ribs 32 ... first arch portion 33 ... second arch portion 34a ... Arch outer wall 34b ... Arch inner wall 34c ... Center A ... Lower leg P1 ... Spacing

Claims (6)

Located at the lower part of the front part of the car body, the rear part is fixed to the car body frame, and when the front part of the car body collides with the lower leg part of the pedestrian, the impact received by the lower leg part is reduced and the return reaction force In a vehicle pedestrian protection device comprising pedestrian protection means for jumping up the lower leg part,
The pedestrian protection means includes
A surface load receiving portion that extends in the vehicle width direction and receives an impact from the lower leg portion by a surface load;
A bending load receiving portion provided at the rear portion of the surface load receiving portion and receiving an impact from the surface load receiving portion by bending deformation;
The vehicular pedestrian protection device according to claim 1, wherein the bending load receiving portion is formed of a honeycomb structure having a plurality of hexagonal cells that are arranged adjacent to each other in the vehicle width direction. The bending load receiving portion is
A honeycomb receiving portion in which the honeycomb structure is disposed along the surface load receiving portion;
2. The vehicle pedestrian protection device according to claim 1, further comprising: an arch-shaped receiving portion that forms the honeycomb structure in an arch shape, and a central portion that protrudes forward of the vehicle body is provided continuously to the honeycomb receiving portion. . The pedestrian protection for a vehicle according to claim 2, wherein an interval between apexes of each hexagonal cell constituting the honeycomb structure of the honeycomb receiving portion is set to about half of a diameter of the lower leg portion. apparatus. 4. The pedestrian protection device for a vehicle according to claim 2, wherein the arch-shaped receiving portion is fixed to the vehicle body frame at a rear portion protruding rearward of the arch portion. The pedestrian protection device for a vehicle according to claim 1, wherein the surface load receiving portion is formed of a truss structure. The surface load receiving portion is formed of a truss structure;
The longitudinal rib which forms the said truss structure of the said surface load receiving part is connected with the vertex of each said hexagonal cell which forms the said honeycomb receiving part, The any one of Claims 2-5 characterized by the above-mentioned. The vehicle pedestrian protection device according to item.

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