JP2015137080A - Vehicle body front part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body front part structure that can exert preferable shock absorption performance without making a gusset that transmits a shock load at a small overlap collision to function at a full-lap collision.SOLUTION: A fixed part 102 of a gusset 100 is fastened to the outside in a vehicle width direction of a front side frame 40, a gusset main body 101 extended while being expanded outside in the vehicle width direction from the fixed part 102 is made to face a backside 60a of a bumper beam 60 in a state where an inner front ridge part 101b of a front end face 101a is brought closest to the main body, and in the fixed part 102 is formed a site functioning as an easily deformable part. At a small overlap collision, a shock load is transmitted through the gusset 100 to a front side frame 40. While, at a full-lap collision, when a bumper beam retreats, the inner front ridge part 101b of the gusset main body 101 is pressed by the backside 60a of the bumper beam and then the gusset main body 101 is folded at the easily deformable part, as a starting point, provided in the fixed part 102 so as to be inclined toward outside in the vehicle width direction.

Description

  The present invention relates to a vehicle body front structure capable of guaranteeing shock load absorption performance in both a small overlap collision, a full wrap collision, and an offset collision.

  In recent years, technological development relating to improvement of collision safety of vehicles represented by automobiles has been advanced. For example, in an offset collision, there is a high interest in collision safety against a small overlap collision (small lap collision) with a smaller amount of lap than a conventional offset collision.

  The small overlap collision is an offset collision on the outer side in the vehicle width direction than the pair of left and right front side frames. As a countermeasure, a gusset is fixed on the outer side in the vehicle width direction of the front side frame, and the impact is passed through the gusset. Many techniques that absorb a shock by transmitting a load to a front side frame and bending the front side frame are employed.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2013-203320), a gusset is provided on the outer side in the vehicle width direction of the front portion of the front side frame, and the front side frame behind the gusset is weakened by a bead on the outer side in the vehicle width direction. A technique is disclosed in which a gap is formed between the tip of the gusset and the bumper beam.

  That is, when the impact load at the time of a small overlap collision is input to a bumper beam that is directly connected to the front end of the front side frame or connected to the front end of the front side frame via a crash box, the front end of the front side frame Or the crash box is crushed and the back of the bumper beam is retracted and pressed against the gusset. Then, an impact load is transmitted to the front side frame through the gusset, and the front side frame is bent inward in the vehicle width direction starting from the fragile portion and is made to collide with a power unit such as an engine so as to absorb the impact. I have to.

JP2013-203320A

  By the way, as disclosed in the above-mentioned document, if the front end portion of the gusset is fixed to the front side frame via the stay, the impact load at the time of the small overlap collision is received by the front end surface of the gusset, and this impact The load can be reliably transmitted in the direction of the front side frame.

  However, if the front end of the gusset is fixed to the front side frame via a stay, the front side receives the impact load in the case of an offset collision with a larger lap amount than a full lap collision (full collision) or a small lap collision. If the front end portion of the frame is deformed rearward, the deformation causes the gusset to be called inward in the vehicle width direction via the stay, which may function as a factor that impedes the impact load absorption characteristics. This also occurs when the tip surface of the gusset is connected to the bumper beam.

  In view of the above circumstances, the present invention can transmit the impact load to the front side frame through a gusset in the case of a small overlap collision, and the gusset is in an impact in the case of a full lap collision or an offset collision. It is an object of the present invention to provide a vehicle body front structure that can guarantee good shock absorption performance without functioning as a factor that inhibits absorption.

  The present invention provides a front side frame that is provided on both sides of the vehicle body in the width direction and extends in the front-rear direction of the vehicle body, a front end portion of the front side frame or a crash box provided at the front end portion, and the front side frame. A bumper beam connected to the front end portion of the crash box or the front end portion of the crash box and extending in the vehicle width direction, and a fixing portion formed at the rear portion are fixed to the outer side in the vehicle width direction of the front side frame, and forward from the fixing portion. In the vehicle body front part structure having a gusset for extending the extending main body part outward in the vehicle width direction so that the front end face of the main body part faces the back surface of the bumper beam, the front end face of the main body part and the bumper beam A gap is provided between the back of the body and the main body is tilted outward in the vehicle width direction upon receiving a shock load in the case of a full lap collision. Easily deformable portion as a starting point of time of is provided.

  According to the present invention, a gap is provided between the front end surface of the main body provided in the gusset and the back surface of the bumper beam, and the main body is fixed to the fixing portion of the gusset fixed to the front side frame in the case of a full lap collision. Is provided with an easily deformable portion that is inclined outward in the vehicle width direction by an impact load from the bumper beam, so that the impact load can be satisfactorily transmitted to the front side frame via the gusset in the case of a small overlap collision. Also, in the case of full lap collision or offset collision, the bumper beam is installed in the gusset when the crash box (the front side frame tip if the front side frame is directly connected to the bumper beam) is crushed and retracted. By pushing the front end face of the part outward in the vehicle width direction and inclining the gusset outward in the vehicle width direction with the easily deformable part as the base, the gusset is removed from the collision load transmission path. It does not function and can guarantee good shock absorption performance.

  In addition, by providing a gap between the front end surface of the main body provided on the gusset and the back surface of the bumper beam, the gusset and side frame do not transmit the load to the gusset or side frame when the bumper beam retracts during a light collision. Can be prevented from being deformed.

Main part schematic plan view of the front part of the car body The main part schematic perspective view which looked at the front part of the body from the diagonally upper rear side outside the vehicle width direction Main part schematic plan view of the vehicle width direction end of the front of the vehicle body Schematic main part perspective view of the vehicle width direction end of the front part of the vehicle body as viewed from diagonally below Schematic plan view showing the state just before the small overlap collision Schematic plan view showing the behavior at the time of small overlap collision Schematic plan view showing the state just before full lap collision Schematic plan view showing the behavior during full lap collision

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 in the drawing denotes a front portion of the vehicle. The vehicle front portion 1 includes an engine 10, a transmission 20, a cabin 30, a front side frame 40, a radiator panel 50, a bumper beam 60, a front subframe 70, and a front wheel 80. A front suspension 90 and the like are provided.

  The engine 10 and the transmission 20 are accommodated in the engine room 1a. The engine 10 is, for example, a horizontally opposed four-cylinder gasoline or diesel engine mounted vertically, and a cylinder head is provided at the top (end in the vehicle width direction) of the left and right banks arranged across the crankshaft. Yes.

  The transmission 20 is coupled to the rear portion of the engine 10, and a transmission device such as a torque converter or a clutch, a transmission device such as a CVT variator or a transmission gear train, and an AWD transfer that distributes driving force to the front and rear wheels in the transmission case. A final reduction gear, a front differential and the like are accommodated.

  The cabin 30 is a portion that is provided at the center of the vehicle and on which an occupant rides. The cabin 30 includes a floor panel 31, a toe board 32, a floor tunnel 33, an A pillar 34, a side sill 35, and the like. The floor panel 31 is a substantially planar portion that constitutes the floor surface of the cabin 30. The toe board 32 is arranged so as to rise upward from the front end of the floor panel 31, and the cabin 30 and the engine room 1 a are partitioned by the toe board 32.

  The floor tunnel 33 is formed by projecting the center of the floor panel 31 in the vehicle width direction to the cabin 30 side, and accommodates a rear portion of the transmission 20, a propeller shaft, an exhaust pipe, and the like (not shown).

  The A pillar 34 is a columnar structural member arranged to protrude upward from the front end portion at the left and right end portions of the floor panel 31, and the side sill 35 extends from the lower end portion of the A pillar 34 to the vehicle rear side. It is a beam-shaped structural member arranged along the side end of the floor panel 31.

  The front side frame 40 is a pair of left and right structural members having a rectangular closed cross section that protrudes from the toe board 32 side of the cabin 30 to the front side of the vehicle, and the opposing surfaces thereof are side portions of the engine 10 (in a horizontally opposed engine). The cylinder head tappet cover) is opposed to the cylinder head with a predetermined interval.

  The radiator panel 50 is a frame-like structure that supports a radiator core that cools the cooling water of the engine 10, a condenser of an air conditioner, and the like, and is disposed in front of the engine 10. Further, the side end portion of the radiator panel 50 is fixed in the vicinity of the front end portion of the front side frame 40.

  The bumper beam 60 is provided inside a bumper face (not shown) that is an exterior part provided at the front end of the vehicle body, and is formed in a beam shape extending substantially along the vehicle width direction. The impact load is transmitted to the rear side of the vehicle body. The bumper beam 60 is formed in a curved arc shape with a convex front side according to the shape of the bumper face. The front end portion of the crash box 61 is connected to the back surface of the bumper beam 60, and the rear end portion of the crash box 61 is connected to the front side. The front end of the side frame 40 is connected. Depending on the type of vehicle, the front end portion of the front side frame 40 may be directly connected to the bumper beam 60. In this case, the crash box 61 may be read as the front end portion 61 of the front side frame 40.

  The front sub frame 70 is disposed below the front side frame 40, and is mounted with an engine mount (not shown) that supports the engine 10, a lower arm 92 of the front suspension 90, and the like. The front subframe 70 is formed in a rectangular frame shape, for example, and fastened to the front side frame 40 or the like by fastening bolts (not shown) provided at the front and rear with bolts (not shown) arranged in the vertical direction. Is attached.

  The front wheel 80 is a front wheel of a vehicle configured by mounting a tire on a rim made of, for example, an aluminum alloy. The front wheel 80 is rotatably supported by a hub bearing housing (not shown), and can be steered by pushing and pulling a tie rod T disposed in front of the axle.

  The tie rod T is coupled to a steering gear box (none of which is shown) connected to a steering wheel via a steering shaft, and is driven substantially along the vehicle width direction in accordance with the steering operation of the driver. 1 and 2, the tire is not shown, and in FIGS. 5 to 8, the rim is not shown.

  The front suspension 90 supports a hub bearing housing that supports the front wheel 80 so as to be swingable with respect to the vehicle body. The front suspension 90 is, for example, a McPherson strut type, and includes a strut 91 and a lower arm. 92 etc.

  The strut 91 (see FIG. 2) is provided between a strut upper mount 93 provided on the upper side of the engine compartment of the vehicle body and a bracket (not shown) provided on the upper portion of the hub bearing housing. The strut 91 is a shock absorber (damper) and a spring unitized.

  The vehicle front portion 1 is provided with a gusset 100 that transmits an impact load at the time of a small overlap collision to the front side frame 40. As shown in FIGS. 1 to 4, the gusset 100 is disposed in a region outside the vehicle width direction in the vicinity of the front end portion of the front side frame 40.

  The gusset 100 includes a main body portion (hereinafter referred to as a “gusset main body”) 101 formed in a rectangular cylindrical cross section, and a flat plate-like fixing portion 102 formed continuously at the rear end of the gusset main body 101. have. The fixing portion 102 has two upper and lower portions predetermined by bolts inserted from the outer side in the vehicle width direction, for example, on the side surface portion on the outer side in the vehicle width direction of the front side frame 40 located on the vehicle front side of the center in the front-rear direction of the engine 10. Fastened and fixed at intervals.

  On the other hand, the gusset 100 is an integrally molded product or made of sheet metal, and the base portion of the gusset body 101 is bent from the front end of the fixed portion 102 and is inclined forwardly outwardly in the vehicle width direction and extends forward. The surface 101 a faces the back surface 60 a of the bumper beam 60.

  Further, a predetermined gap 110 is provided between the front end surface 101 a of the gusset body 101 and the back surface 60 a of the bumper beam 60. As shown in FIGS. 1 to 3, the gap 110 has a wedge shape that expands from the inner side to the outer side in the vehicle width direction. In other words, the front end face 101a of the gusset body 101 is opposed to the back face 60a of the bumper beam 60, and therefore, the ridge part on the inner side in the vehicle width direction of the front end face 101a (hereinafter referred to as the inner front end ridge part). 101b) is closest to the back surface 60a of the bumper beam 60.

  The guide members 120, 130, and 140 are provided on the back surface 60a of the bumper beam 60 and on the side surfaces of the gusset body 101 facing the front end surface 101a, that is, the upper side, the lower side, the vehicle width direction outer side, and the vehicle width direction inner side. , 150 are arranged so as to surround the front end face 101a of the gusset body 101, respectively. Each of these guide members 120, 130, 140, 150 regulates the relative movement of the front end surface 101 a of the gusset body 101 in the vertical and horizontal directions. By these respective guide members 120, 130, 140, 150, the bumper beam 60 is retracted in a state of being guided by the respective guide members 120, 130, 140, 150 in the initial behavior at the time of the small overlap collision, and the gap 110 is moved. After being reduced and pressed against the gusset body 101, the impact load can be reliably transmitted to the gusset 100.

  Further, at least the vehicle width direction outer side guide member (hereinafter referred to as “outer side guide member”) 140 is formed with a plate thickness thinner than the vehicle width direction inner side guide member (hereinafter referred to as “inner side guide member”) 150. Has been. By forming the outer guide member 140 with a thin plate thickness, a load on the outer side in the vehicle width direction is applied to the gusset body 101 in the case of a full wrap collision described later or an offset collision having a larger wrap amount than a small wrap collision. The outer guide member 140 can be easily broken or bent by the pressing force, and the gusset body 101 can be released to the outside in the vehicle width direction. Each guide member 120, 130, 140, 150 may be fastened and fixed to the back surface 60a of the bumper beam 60 using a bolt or the like, or may be fixed by welding. Alternatively, the bumper beam 60 may be integrally formed.

  In addition, a separator 41 (see FIG. 1) that substantially closes the internal cross section of the front side frame 40 is provided near the fixing portion 102 of the gusset 100 in the front side frame 40.

  Furthermore, two beads 42 are formed at predetermined intervals in the front-rear direction in a side surface portion of the front side frame 40 on the outer side in the vehicle width direction and adjacent to the rear of the fixed portion 102 of the gusset 100. The bead 42 locally decreases the rigidity of the front side frame 40 and serves as a starting point when the front side frame 40 is bent inward in the vehicle width direction in the case of a small overlap collision.

  Next, the behavior of the gusset 100 at the time of a small overlap collision and a full lap collision will be described with reference to FIGS. In addition, since each school part is typically represented in FIGS. 5-8, there exists a part slightly different from the positional relationship of each part shown in FIGS. For example, the front end surface 101a of the gusset body 101 is described as facing the back surface 60a of the bumper beam 60 substantially in parallel, but in reality, the gusset body 101 faces in the inclined state as shown in FIGS. Has been. For ease of explanation, the upper guide member 120 and the lower guide member 130 are omitted.

[Small overlap collision]
First, the behavior at the time of a small overlap collision will be described. Symbol Bo in FIGS. 5 and 6 is an offset barrier, which imitates an opponent vehicle, standing tree, utility pole, or the like. As shown in FIG. 5, the bumper beam 60 on the outer side (side end portion) in the vehicle width direction than the front side frame 40 of the vehicle is close to the offset barrier Bo.

  Then, as shown in FIG. 6, when the bumper beam 60 of the vehicle collides with the offset barrier Bo with a load Ft (small overlap collision), the impact load, which is the reaction force, is applied to the crash box 61 (or via the bumper beam 60). The axial compression load is transmitted from the crash box 61 (or the front end portion 61 of the front side frame 40) to the front side frame 40.

  On the other hand, the side end portion of the bumper beam 60 is deformed by receiving an impact load, presses the front end surface 101a of the gusset body 101 facing the back surface 60a, and transmits an axial compressive load to the gusset body 101. At that time, the gusset body 101 is only cantilevered by the fixed portion 102, and the front end surface 101a is a free end, so that it can easily move relative to the back surface 60a of the bumper beam 60 in the vertical and horizontal directions. There is a possibility that the impact load is not efficiently transmitted to the gusset body 101 as an axial load. Therefore, in the present embodiment, the outer periphery of the front end surface 101a of the gusset body 101 is surrounded by the guide members 120, 130, 140, and 150, and the relative movement in the vertical and horizontal directions is regulated by the guide members. An axial load can be efficiently transmitted to 101.

  The collision load transmitted to the gusset body 101 is applied to the side surface on the outer side in the vehicle width direction of the front side frame 40 via the fixed portion 102 in a direction of pushing obliquely forward inward in the vehicle width direction. Then, the front side frame 40 is bent and deformed to the inner side in the vehicle width direction from the periphery of the bead 42 formed on the side surface with the pushing load as a starting point of the folding. And when this bending deformation amount becomes more than predetermined, it collides with the cylinder head (tuppet cover) of the engine 10 facing this.

  Thereafter, when the amount of relative retreat of the offset barrier Bo with respect to the vehicle body (the amount of relative advance of the vehicle body with respect to the offset barrier Bo) further increases, the front side frame 40 causes the engine 10 to collide with the opposite side in the vehicle width direction (offset barrier Bo). Press to the side not to be displaced. At this time, the uncrushed region at the front end portion of the front side frame 40 functions as a pressing member that pushes further outward in the vehicle width direction of the engine 10 with an axial impact force.

  As described above, the heavy engine 10 is pressed to the opposite side in the vehicle width direction, so that the vehicle changes its direction to avoid the offset barrier Bo, and the A pillar 34 and the side sill 35 of the cabin 30. The transmission load to etc. is reduced. Further, the front side frame 40 functions as an energy absorber that itself absorbs energy by the bending deformation described above.

[Full lap collision]
Next, the behavior at the time of a full lap collision will be described. 7 and 8 is a flat barrier, which simulates an oncoming vehicle or the like at the time of a full lap collision. As shown in FIG. 7, when the vehicle approaches the flat barrier Bf and a full lap collision (full collision) occurs with the load Ft, the reaction force is applied to the front surface of the bumper beam 60.

  As a result, the bumper beam 60 is bent, and as shown by a one-dot chain line in FIG. 7, the side end portion thereof is temporarily elastically deformed linearly and extended outward in the vehicle width direction. At that time, the inward guide member 150 facing the inner side in the vehicle width direction of the front end surface 101a of the gusset body 101 presses the front end of the gusset body 101 outward in the vehicle width direction as indicated by an arrow.

  Then, the gusset body 101 is inclined outward in the vehicle width direction with the fixed portion 102 as a starting point. At this time, the gusset body 101 may collide with the outer guide member 140, but the outer guide member 140 is formed with a thinner plate thickness than the inner guide member 150, and the impact from the gusset body 101. It is easily bent or broken by a load. Accordingly, the outer guide member 140 does not hinder the gusset body 101 from tilting outward in the vehicle width direction.

  At the same time, the bumper beam 60 is retracted by receiving an impact load at the time of a full lap collision. When the front side frame 40 is directly connected to the bumper beam 60, the tip of the front side frame 40 is crushed or crashed. When the box 61 is interposed, the crush box 61 is crushed. At this time, the front end surface 101a of the gusset body 101 is opposed to the back surface 60a of the bumper beam 60, so The front edge ridge 101b is pressed first. Then, since an impact load is applied to the gusset body 101 from an oblique front inside in the vehicle width direction, the gusset body 101 is inclined outward in the vehicle width direction from the fixed portion 102 by the pressing force.

  As a result, the gusset body 101 is inclined outward in the vehicle width direction from the fixed portion 102 by the pressing force received from the outer guide member 140 and the bumper beam 60 in the process in which the impact load is applied to the bumper beam 60. It deviates from the path where the impact load at the time of full flap collision is transmitted. Therefore, it does not function as a factor that inhibits shock absorption, and good shock absorption performance can be ensured in a full-wrap collision.

  By the way, when the inner front edge ridge 101b of the gusset body 101 receives a pressing force from the inner guide member 150 and the back surface 60a of the bumper beam 60 and is inclined outward in the vehicle width direction, the inclination of the gusset body 101 is cylindrical. Therefore, the fixed portion 102 side is the starting point. In the present embodiment, the fixing portion 102 is fastened and fixed to the front side frame 40 at two upper and lower portions with bolts or the like.

  Therefore, since the gusset body 101 is inclined by bending at least the front end side of the fastening portion of the fixing member 102, the front end side of the fastening member 102 functions as the easily deformable portion of the present invention. Become. Further, for example, when the gusset 100 is made of sheet metal and the boundary between the base portion of the gusset body 101 and the front end portion of the fixed portion 102 is bent and inclined, it is easy to be inclined from the bent portion. The bent portion functions as the easily deformable portion of the invention.

  By the way, an easily deformable part forms a weak part by a notch, a round hole, a long hole, or a bottleneck part in the front end direction rather than the fastening part of fixed part 102, and makes this weak part function as an easily deformable part. Thus, the easily deformable portion can be set at a desired position.

  As described above, according to the present embodiment, the impact load can be satisfactorily transmitted to the front side frame through the gusset in the case of the small overlap collision, and the gusset is attached to the vehicle in the case of the full wrap collision. By tilting outward in the width direction so as to deviate from the path through which the impact load is transmitted, good shock absorption can be obtained.

  Note that the present invention is not limited to the above-described embodiment. For example, the action at the time of a full-lap collision can be applied as it is to an offset collision having a larger overlap amount than the above-described small overlap collision.

1 ... Vehicle front,
10 ... Engine,
40 ... Front side frame,
42 ... Bead,
60 ... Bumper Beam,
60a ... the back,
61 ... Crash box (or front end of front side frame),
100 ... Guset,
101 ... gusset body,
101a ... front end face,
101b ... Inner front edge ridge,
102 ... fixed part,
110 ... the gap,
150 ... inner guide member,
Bf ... Flat barrier,
Bo ... Offset barrier,
Ft ... Load

Claims (6)

A front side frame provided on both sides in the width direction of the vehicle body and extending in the front-rear direction of the vehicle body;
A front end of the front side frame or a crash box provided at the front end;
A bumper beam connected to the front end of the front side frame or the front end of the crash box and extending in the vehicle width direction;
A fixing part formed at the rear part is fixed to the outer side in the vehicle width direction of the front side frame, a main body part extending forward from the fixing part is expanded outward in the vehicle width direction, and the front end surface of the main body part is In the vehicle body front structure having a gusset facing the back of the bumper beam,
A gap is provided between the front end surface of the main body and the back surface of the bumper beam;
A vehicle body front structure characterized in that an easy-to-deform portion is provided on the fixed portion as a starting point when the main body portion is inclined outward in the vehicle width direction under an impact load at the time of a full lap collision. The vehicle body front structure according to claim 1, wherein the fixing portion is fastened to the front side frame, and functions between the fixing portion and the main body portion as the easily deformable portion. The vehicle body front part structure according to claim 1, wherein the easily deformable portion is provided in a bent portion formed around the fixed portion and at a boundary with the main body portion. The vehicle body front part structure according to claim 1, wherein the easily deformable portion functions by forming a weak portion in the fixed portion. The said main-body part is formed in the cylindrical cross section, and this main-body part has the vehicle width direction inner side ridge part of the said front end surface closest to the back surface of the said bumper beam. The vehicle body front structure according to claim 1. The vehicle body front part structure according to any one of claims 1 to 5, wherein a guide part provided on the bumper beam is opposed to a side surface of the front end part in the vehicle width direction of the main body part.

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