JP5736943B2 - Vehicle front structure - Google Patents

Description

  The present invention relates to a front structure of a vehicle.

  A vehicle body front structure in which a subframe is disposed across a cross member and a dash panel and a front arm and a rear arm of a suspension arm are attached to the subframe is conventionally known. (For example, refer to Patent Document 1).

  In the vehicle body front part structure described in Patent Document 1, a fragile part is formed at an appropriate position of the subframe, and when the vehicle collides, the subframe is buckled by the fragile part to rotate the front wheel in the vehicle width direction. By making it move, the energy absorption stroke is secured.

JP 2002-127936 A

  However, the vehicle body front structure described in Patent Document 1 is a structure in which the suspension arm, that is, the front wheel is not detached from the subframe, so that it is sufficient for a load input from the front of the vehicle, such as during a vehicle front collision. There is a risk that a sufficient energy absorption stroke is not secured.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to obtain a vehicle front structure that can secure a sufficient energy absorption stroke with respect to a load input from the front of a vehicle body.

In order to achieve the above object, a vehicle front structure according to a first aspect of the present invention is connected to a front side arm connected to a vehicle body front side of a suspension member and to a vehicle body rear side of the suspension member. A rear arm, and a suspension arm to which a front wheel of the vehicle is attached, and a substantially U shape in plan view with an outer side in the vehicle width direction open, and the front arm of the suspension arm and the a connecting member for connecting the rear arm to each of the suspension member, is formed on the vehicle body rear side portion of the connecting member connecting the front arm, the front side to move the load inputted from the vehicle front a weak portion disengaging the front arm from said suspension member by being destroyed by the arm, said Provided on the wall surface facing the fragile portion of Ronto side arm, is characterized by having a frangible means to facilitate breaking the said weakened portion.

According to the first aspect of the present invention , the fragile portion is formed in the vehicle body rear side portion of the connecting member that connects the front side arm of the suspension arm .

And the easy destruction means which promotes destruction of a weak part is provided in the wall surface facing the weak part of a front side arm .

Therefore, when the front arm of the suspension arm moves due to a load input from the front of the vehicle, such as when the vehicle collides, the fragile portion is destroyed by the front arm .

That is, the vehicle body rear side portion of the connecting member is destroyed. As a result, the front arm of the suspension arm, that is, the front wheel is easily detached from the suspension member .

Therefore, a sufficient energy absorption stroke can be ensured for the load input from the front of the vehicle body .

Further, the vehicle front structure according to claim 2 is the vehicle front structure according to claim 1 , wherein the connecting member that connects the front side arm is located outward of the vehicle rear side portion in the vehicle width direction. A protruding length that protrudes is longer than a protruding length that protrudes outward in the vehicle width direction of the front side portion of the vehicle body, and the weakened portion is more than a virtual region of the rear side portion of the vehicle body that projects the front side portion of the vehicle body. It is characterized by being formed outside in the vehicle width direction .

According to the second aspect of the present invention, even if the weakened portion is formed in the vehicle body rear side portion of the connecting member that connects the front side arm, the strength of the vehicle body rear side portion of the connecting member can be reduced. Absent. That is, the rigidity required for normal traveling is ensured in the vehicle body rear side portion of the connecting member .

Further, the vehicle front structure according to claim 3 is the vehicle front structure according to claim 1 or 2 , wherein the vehicle front side end of the front wheel is ahead of the vehicle body front side end of the suspension member. The part is arranged on the front side of the vehicle body.

According to the third aspect of the present invention, the load input from the front of the vehicle body can be transmitted to the front wheels before the suspension member. Therefore, since the load can be effectively transmitted to the suspension arm via the front wheel, the breakage of the fragile portion by the suspension arm can be promoted. That is, this makes it easier to remove the front wheel from the suspension member.

  As described above, according to the present invention, it is possible to provide a vehicle front structure that can secure a sufficient energy absorption stroke with respect to a load input from the front of the vehicle body.

It is a sectional side view which shows the schematic structure of the vehicle front part side. It is a top view which shows the vehicle front part structure which concerns on this embodiment. It is a top view which expands and shows the vehicle front part structure which concerns on this embodiment. It is a perspective view of the mounting bracket which comprises the vehicle front part structure which concerns on this embodiment. FIG. 5 is a cross-sectional view taken along line X-X in FIG. 4. (A) It is a perspective view which shows the mounting bracket which comprises the vehicle front part structure which concerns on this embodiment, and the front side arm of a suspension arm. (B) It is a perspective view which shows the front side arm of a suspension arm. It is a top view which shows the effect | action of the vehicle front part structure which concerns on this embodiment when a load is input from the vehicle body front. It is a top view which shows the effect | action of the vehicle front part structure which concerns on the comparative example when a load is input from the vehicle body front.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In each figure, the arrow UP indicates the vehicle body upward direction, the arrow FR indicates the vehicle body front direction, and the arrow OUT indicates the vehicle width direction outer side. In the following description, both sides in the vehicle width direction may be simply referred to as left and right.

  As shown in FIG. 1, the vehicle according to the present embodiment has a resin body structure, and a resin underbody 12 provided on the vehicle body lower side and a front suspension provided on the vehicle body front side of the underbody 12. The module 14 includes a resin-made front energy absorbing member (hereinafter referred to as “front EA member”) 16 provided on the front side of the vehicle body of the front suspension module 14.

  The underbody 12 has a substantially rectangular shape in plan view, and has a floor portion 20 having a flat (flat) lower wall 18 along a substantially horizontal plane, and is erected from the vehicle body front side end portion of the floor portion 20 toward the vehicle body upper side. The dash lower portion 22 is configured. The length of the dash lower portion 22 in the vehicle width direction is substantially the same as the length of the floor portion 20 in the vehicle width direction, and has a substantially rectangular shape that is long in the vehicle width direction.

  Further, the dash lower portion 22 has a closed cross-sectional structure, and is erected on the left and right rockers (not shown) and the front end portion of the center skeleton forming portion. Specifically, the dash lower portion 22 includes a front wall 24 and a rear wall 26 that oppose the vehicle body longitudinal direction, and an upper wall 28 that opposes the lower wall 18. 18, the front wall 24, the rear wall 26, and the upper wall 28 constitute a closed cross-sectional structure.

  And the lower part of the rear wall 26 which comprises this dash lower part 22 is made into the inclined wall 26S. The inclined wall 26S is inclined with respect to the front and rear (horizontal) direction of the vehicle body so that the rear end side is located on the vehicle body lower side from the front end side, and the front upper end thereof is substantially along the vehicle vertical direction of the rear wall 26. The upper and lower walls 26U are continuous with the lower end portion. The rear lower end portion of the inclined wall 26 </ b> S is continuous with the front end portion of the upper wall 28.

  As shown in FIG. 2, the front suspension module 14 includes at least a metal suspension member 30 and a pair of left and right metal suspension arms 40. The suspension member 30 is elongated in the vehicle width direction and has a closed cross-sectional structure in a side sectional view (see FIG. 1). The suspension member 30 supports the front wheel 50 via the suspension arm 40 so as to be steerable.

  As shown in FIGS. 1 and 2, the front EA member 16 is a large component that is elongated in the vehicle width direction. Specifically, the front EA member 16 has a length in the vehicle width direction that is substantially the same as the length in the vehicle width direction of the vehicle body front side wall surface of the suspension member 30.

  Further, the front EA member 16 is configured in a box shape (substantially rectangular box shape) that is open on the rear side of the vehicle body, and a flange portion 16A that protrudes outward from the vehicle rear side end portion in the vehicle width direction. A flange portion 32 (described later) of the suspension member 30 is fixed to a wall surface 36 on the front side of the vehicle body.

  In addition, as a resin material which comprises the underbody 12 and the front EA member 16, the fiber reinforced resin containing reinforcement fibers, such as carbon fiber, glass fiber, an aramid fiber, etc. are mentioned, for example. As shown in FIG. 2, a front bumper cover 38 made of the same resin is disposed on the front side of the vehicle body of the front EA member 16.

  Next, the front structure 10 of the vehicle having the resin body structure as described above will be described in detail. As shown in FIGS. 2 and 3, a flange portion 32 that projects to the front side of the vehicle body and a flange portion 34 that projects to the rear side of the vehicle body are integrally formed at the outer end in the vehicle width direction of the suspension member 30. ing. Then, fixing portions 55 and 65 of metal mounting brackets 52 and 62, which will be described later, are fixed to the flange portions 32 and 34, respectively, by welding or the like.

  The suspension arm 40 includes a front side arm 42 connected to a flange portion 32 on the vehicle body front side of the suspension member 30 via a mounting bracket 52, and a mounting bracket 62 on a flange portion 34 on the vehicle body rear side of the suspension member 30. A so-called A-arm having a rear-side arm 44 connected thereto.

  Cylindrical portions 46 and 48 having through holes 46A and 48A (see FIG. 3) penetrating in the longitudinal direction of the vehicle body are integrally formed at the inner ends in the vehicle width direction of the front arm 42 and the rear arm 44, respectively. . And the vehicle width direction outer side edge part of the front side arm 42 and the rear side arm 44 is integrally connected, and the front wheel 50 is attached.

  Further, metal mounting brackets 52 and 62 as connecting members fixed to the flange portions 32 and 34 of the suspension member 30 are each formed in a substantially “U” shape in plan view with the vehicle width direction outer side opened. ing.

  That is, each of the mounting brackets 52 and 62 extends in the longitudinal direction of the vehicle body and is fixed to the flange portions 32 and 34 from the flat plate-like fixing portions 55 and 65 and the vehicle body front side edge portion of the fixing portions 55 and 65. A flat front wall portion 54, 64 as a vehicle body front side portion integrally extending outward in the vehicle width direction and a vehicle body rear side edge portion of the fixing portions 55, 65 are integrally extended outward in the vehicle width direction. Plate-like rear wall portions 56 and 66 as rear side portions of the vehicle body.

  Through holes 58 and 68 for inserting bolts 72 are formed in the front wall portions 54 and 64 and the rear wall portions 56 and 66 of the mounting brackets 52 and 62, respectively. Accordingly, the cylindrical portion 46 of the front arm 42 is disposed in the mounting bracket 52, and for example, the bolt 72 is inserted into the through holes 58, 46 </ b> A, 58 from the rear side of the vehicle body, and the tip thereof is screwed into the nut 74. The cylinder portion 46 of the front arm 42 is coupled to the suspension member 30 via the mounting bracket 52.

  Similarly, the cylinder portion 48 of the rear side arm 44 is disposed in the mounting bracket 62, and for example, the bolt 72 is inserted into the through holes 68, 48 </ b> A, 68 from the front side of the vehicle body, and the tip thereof is screwed into the nut 74. Thus, the cylinder portion 48 of the rear arm 44 is connected to the suspension member 30 via the mounting bracket 62. In other words, this is a configuration in which the suspension member 30 is connected to the inner end of the suspension arm 40 in the vehicle width direction.

  A rubber bush (not shown) is provided between the front wall portion 54 and the cylindrical portion 46 of the mounting bracket 52 and between the rear wall portion 56 and the cylindrical portion 46. Similarly, rubber bushes (not shown) are provided between the front wall portion 64 and the cylindrical portion 48 of the mounting bracket 62 and between the rear wall portion 66 and the cylindrical portion 48.

  As shown in FIGS. 3 and 4, the protruding length of the rear wall portion 56 of the mounting bracket 52 that connects the front arm 42 to the suspension member 30 in the vehicle width direction outside is the vehicle width of the front wall portion 54. It is formed longer than the protruding length to the outside in the direction. Specifically, the rear wall portion 56 is formed longer than the virtual region K on which the front wall portion 54 is projected outward in the vehicle width direction (projection direction side) (see FIG. 4). Even if the front side arm 42 swings, the length does not interfere with the front side arm 42 (see FIG. 3).

  Then, the front end of the rear wall portion 56 of the mounting bracket 52 is protruded toward the rear side of the vehicle body due to a load (excessive load) input from the front of the vehicle body, such as during a frontal collision of the vehicle. A fragile portion 60 is formed which is broken by the front side arm 42 moving toward the front side and allows the front side arm 42 to be detached from the suspension member 30.

  Specifically, as shown in FIGS. 4 and 5, the fragile portion 60 has a substantially arc-shaped cross section that extends in a direction parallel to the protruding direction (vehicle width direction) of the rear wall portion 56 of the mounting bracket 52. It is a thin-walled part. And the extension length of this weak part 60 is formed in the area | region of the protrusion direction side (vehicle width direction outer side) rather than the virtual area K of the rear wall part 56 which projected the front wall part 54 (virtual area | region). (Not reaching K) (see FIG. 4).

  As described above, when the region where the fragile portion 60 is formed is outside the virtual region K, the strength (rigidity) of the mounting bracket 52 during normal traveling can be secured (maintained). That is, by this, even if the weak part 60 is formed in the rear wall part 56 of the mounting bracket 52, it is the structure which can prevent a trouble at the time of normal driving | running | working.

  As shown in detail in FIGS. 3 and 6, a protrusion 70 as an easy-breaking means for making the fragile portion 60 easy to break is integrated with the wall surface 42 </ b> A of the front arm 42 facing the fragile portion 60. Is formed. The protrusion 70 has a triangular cross section. When the front side arm 42 is moved to the rear side of the vehicle body by a load input from the front of the vehicle body, the tip of the protrusion 70 presses the fragile portion 60. Thus, the rear wall portion 56 is broken (the rear wall portion 56 is cut using the fragile portion 60 as a trigger).

  Further, in the plan view shown in FIG. 2, the vehicle body front side end portion 50 </ b> A of the front wheel 50 is located on the vehicle body front side rather than the vehicle body front side end portion 32 </ b> A of the flange member 32. Are arranged (indicated by a one-dot chain line in FIG. 2). As a result, when a load is input from the front of the vehicle body, such as during a frontal collision of the vehicle, the load is input to the front wheels 50 before the suspension member 30.

  Next, the operation of the vehicle front structure 10 having the above configuration will be described. When a load is input from the front of the vehicle body, such as during a frontal collision of the vehicle, first, the front EA member 16 receives the load and absorbs energy. Further, when the load is input to the front wheel 50, the front side arm 42 of the suspension arm 40 to which the front wheel 50 is attached moves to the rear side of the vehicle body.

  When the front arm 42 moves to the rear side of the vehicle body, the projecting portion 70 presses the fragile portion 60 and destroys the fragile portion 60. Thereby, the rear wall portion 56 is cut by the weakened portion 60 from the front end portion in the protruding direction (vehicle width direction outer side) until reaching the through hole 58, and the bolt 72 is detached from the inside of the through hole 58 of the rear wall portion 56. Is done.

  Here, when the front side arm 42 moves to the rear side of the vehicle body, a pressing force is applied to the rear wall portion 56 toward the inner side in the vehicle width direction by the bolt 72. Therefore, the front end portion of the rear wall portion 56 in the protruding direction is not cut by the bolt 72. Therefore, the fragile portion 60 is formed at the projecting direction side front end portion of the rear wall portion 56, and the front end portion of the rear wall portion 56 in the projecting direction side is cut using the fragile portion 60 as a trigger. I am trying to leave.

  On the other hand, at this time, a pressing force is applied to the front wall portion 54 of the mounting bracket 52 by the bolt 72 toward the outside in the vehicle width direction. As a result, the front end portion of the front wall portion 54 is cut by the bolt 72 in the protruding direction side (vehicle width direction outer side) from the through hole 58. That is, as a result, the bolt 72 is detached from the inside of the through hole 58 of the front wall portion 54.

  With the above action, when a load is input from the front of the vehicle body, the bolt 72 is completely detached from the through holes 58 of the front wall portion 54 and the rear wall portion 56 of the mounting bracket 52 as shown in FIG. The Therefore, the front arm 42 of the suspension arm 40 is completely detached from the mounting bracket 52.

  Therefore, as in the comparative example shown in FIG. 8, the energy absorption stroke can be increased as compared with the structure in which the front arm 42 of the suspension arm 40 is not detached from the mounting bracket 52 (a sufficient energy absorption stroke is obtained). be able to).

  That is, in the structure according to this comparative example, the rear wall portion 56 of the mounting bracket 52 is not cut by the bolt 72, so the front arm 42 of the suspension arm 40 is not detached from the mounting bracket 52.

  Therefore, the energy absorption stroke can only be gained by deformation of the flange portion 32 of the suspension member 30 to which the mounting bracket 52 is fixed, but the front wheel 50 is difficult to move to the rear side of the vehicle body only by the deformation amount of the flange portion 32. A sufficient energy absorption stroke cannot be obtained (the front wheel 50 hinders the energy absorption stroke with respect to the input load).

  However, in the case of the vehicle front structure 10 according to the present embodiment, the front wheel 50 can move to the rear side of the vehicle more greatly than the structure according to the comparative example due to the load input from the front of the vehicle. 50 does not interfere with the energy absorption stroke for the input load. Therefore, a sufficient energy absorption stroke can be obtained for the input load.

  As mentioned above, although the vehicle front part structure 10 which concerns on this embodiment was demonstrated based on drawing, the vehicle front part structure 10 which concerns on this embodiment is not limited to the thing of illustration, The summary of this invention The design can be changed as appropriate without departing from the scope.

  For example, the front arm 42 of the suspension arm 40 is configured to be completely detached from the mounting bracket 52 when a load is input from the front of the vehicle body (energy due to deformation of the flange portion 32 of the suspension member 30). Since the absorption stroke is not obtained), the fixed portion of the suspension member 30 to which the fixing portion 55 of the mounting bracket 52 is fixed may not be the flange portion 32.

DESCRIPTION OF SYMBOLS 10 Vehicle front part structure 30 Suspension member 40 Suspension arm 42 Front side arm 42A Wall surface 44 Rear side arm 50 Front wheel 52 Mounting bracket (connection member)
54 Front wall (front side of vehicle body)
56 Rear wall (rear side)
60 vulnerable parts 70 protrusions (easy to break)
K virtual region

Claims (3)

A suspension arm having a front side arm connected to the vehicle body front side of the suspension member and a rear side arm connected to the vehicle body rear side of the suspension member, to which a front wheel of the vehicle is attached;
A connecting member for connecting the front side arm and the rear side arm of the suspension arm to the suspension member, each being formed in a substantially “U” shape in plan view with the vehicle width direction outer side opened ;
The formed a front-side arm to the vehicle body rear side portion of the connecting member connecting, disengaging the front arm from said suspension member by being broken by the front-side arm is moved by the load inputted from the vehicle front Vulnerable areas,
Easily breakable means for facilitating breakage of the fragile portion, provided on a wall surface facing the fragile portion of the front side arm,
A vehicle front structure characterized by comprising: The connecting member that connects the front side arm is formed such that a protruding length that protrudes outward in the vehicle width direction of the vehicle rear side portion is longer than a protruding length that protrudes outward in the vehicle width direction of the vehicle front side portion,
2. The vehicle front structure according to claim 1, wherein the fragile portion is formed on an outer side in a vehicle width direction with respect to a virtual region of the vehicle body rear side portion projected from the vehicle body front side portion . The vehicle front part structure according to claim 1 or 2, wherein a vehicle body front side end portion of the front wheel is disposed on a vehicle body front side with respect to a vehicle body front side end portion of the suspension member .

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