JP6076798B2 - Front body structure of automobile - Google Patents

Description

  The present invention relates to a front body structure of an automobile in which a fender bracket is fixed on a cowl side member constituting a side wall of an engine room, and the fender is attached to the bracket.

  Conventionally, for example, Patent Document 1 discloses a front body structure of this type of automobile. In this conventional structure, a fender bracket having a pair of front and rear mounting flanges on the cowl side member constituting the side wall of the engine room and having a substantially hexagonal shape with the cowl side member in a vehicle side view is disposed. The mounting flange is fixed by welding to the upper wall of the cowl side member, and the fender is attached to the fender bracket.

JP 2006-205806 A

  In the conventional structure, when an impact load due to the entry of a collision object such as a pedestrian is applied during a vehicle collision, the fender bracket buckles and absorbs the impact load. However, in the case of the conventional substantially hexagonal fender bracket, as shown by the broken line in FIG. 7 showing the impact load absorption characteristic, it is easy to buckle at the beginning of the collision, so that the load (reaction force) G1 ′ at the beginning of the collision is increased. Since it is difficult to control the bracket, the bracket bottoms out on the vehicle body member in the late stage of the collision, and the load G2 ′ may become unnecessarily high. As a countermeasure for this problem, if the thickness of the bracket is increased or a simple hat shape is used, it becomes difficult to buckle and a problem that the load becomes too high occurs. On the other hand, when the buckling performance of the bracket is increased, the rigidity (displacement rigidity) against displacement when a person pushes the fender with his / her hand during normal use deteriorates, and the fender is likely to be displaced.

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a front body structure of an automobile in which shock absorption characteristics can be easily controlled.

The present invention is a front body structure of an automobile in which a fender bracket is fixed on a cowl side member constituting a side wall of an engine room, and the fender is attached to the fender bracket.
The fender bracket includes a bracket body having a bent portion in the middle of the front, rear corner, and front and rear vertical sides of the top side and the front and rear vertical sides, and a lower end of the rear vertical side. It has a rear flange that is bent at the rear of the vehicle and a front flange that extends downward as it is from the lower end of the front vertical side, and forms a substantially hexagonal shape with the cowl side member in a side view of the vehicle. The rear flange is fixed to the upper wall surface of the cowl side member, and the front flange is fixed to the front wall surface of the cowl side member.

When a vehicle collides with a pedestrian, the pedestrian usually enters the fender from the upper front of the vehicle, not from directly above the vehicle. In such a case, the fender bracket should buckle toward the rear of the vehicle. And According to the front vehicle body structure of the automobile according to the present invention, the front flange of the fender bracket is formed so as to extend downward from the lower end portion of the front vertical side portion having the bent portion at the top portion and the middle portion. Compared to the conventional structure in which the front flange is bent forward of the vehicle, it is easy to control in the direction of increasing the load at the initial stage of the collision.

On the other hand, since the front flange is fixed to the front wall surface of the cowl side member, a ridgeline is generated in the front flange when the front flange is strongly pressed against the front end corner of the cowl side member in the middle of the collision. Side buckling can be started stably from the ridgeline.

Thus, in the present invention, the buckling load between the initial stage and the end of the collision can be easily controlled in the direction of increasing the initial load of the collision, and the buckling start timing in the middle stage of the collision can be easily controlled by the thickness of the bracket. It is easy to control the waveform, and as a result, pedestrian protection performance can be improved.

Moreover, since the pedestrian protection performance can be improved only by devising the shape of the fender bracket, there is no problem that the structure of the fender bracket is complicated and the weight and cost increase.

Furthermore, the vehicle front side of the fender bracket has a bent portion only at the top and midway, and does not have a bent portion at the front flange portion. Therefore, compared with the conventional structure having a bent portion at the front flange portion. This improves the hand pushing rigidity during normal use.

1 is a front perspective view of an automobile in which a front body structure according to Embodiment 1 of the present invention is adopted. FIG. 2 is a sectional front view of the front vehicle body structure (sectional view taken along line II-II in FIG. 1). It is a front perspective view of the front body structure. It is a side view of the front body structure. FIG. 5 is a cross-sectional front view (cross-sectional view taken along the line V-V in FIG. 4) of the front body structure. It is explanatory drawing of the shock absorption process of the said front body structure. It is a figure which shows the shock absorption characteristic of the said front-body structure.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 7 are views for explaining a front body structure of an automobile according to Embodiment 1 of the present invention. In this embodiment, front, rear, left, and right refer to the front from the passenger compartment. It means front, back, left and right as seen.

  In the figure, reference numeral 1 denotes a front vehicle body of an automobile. The front vehicle body 1 is fixed on the cowl side members 3 and 3 constituting the left and right walls of the engine room 2 and the cowl side members 3 and 3. The left and right fenders 11 and 11 attached to the fender brackets 4 and 4 and the hood hinges 12 and 12 fixed on the left and right cowl side members 3 are attached to the upper opening of the engine room 2. And a hood 13 for opening and closing.

  Each cowl side member 3 is fixed on the cowl side 8 constituting the most part of the engine compartment side wall and the cowl side 8, and the height position of the hood hinge 6 is set to a height corresponding to the vehicle type. And a hinge rein hose 10 fixed on the raising member 9 to which the hood hinge 6 is fixed.

The cowl side 8 has a closed cross-section structure in which a cowl side outer 8a and a cowl side inner 8b are joined to each other by spot welding of flanges 8c and 8d.

The raising member 9 has a hat shape in cross section, a flange portion 9a is joined to the upper wall of the cowl side outer 8a by spot welding, and forms a closed sectional structure with the cowl side outer 8a.

  The hinge rein hose 10 includes a hinge attachment portion 10a fixed to the raising member 9 by welding and a fender bracket attachment portion 10b extending forward from the hinge attachment portion 10a. The hinge mounting portion 10a has a U-shaped cross section, the vertical side portion 10d is welded and fixed to the side wall portion 9c of the raising member 9, and a closed cross section structure is formed with the upper wall portion 9b. The hood hinge 12 is fastened and fixed to the hinge mounting portion 10a by a bolt 12a.

  A vertical wall portion 10c is bent downward at the front end portion of the fender bracket mounting portion 10b so as to form a front end corner portion 10b '. Both the vertical wall portion 10c and the fender bracket mounting portion 10b have a shallow cross section. It has a U shape.

  The fender bracket 4 includes a bracket body 5 having a top side portion 5a and front and rear vertical side portions 5b and 5c, a rear flange 6 bent from the lower end portion of the rear vertical side portion 5c to the rear of the vehicle, A front flange 7 extending downward from the lower end of the front side 5b.

The corner portions of the top side 5a and the front and rear vertical sides 5b and 5c are front and rear upper bent portions 5d and 5e, and the front and rear vertical sides 5b and 5c have a front portion in the middle. , Rear bent portions 5f and 5g are formed.

Furthermore, the corner portion between the rear vertical side portion 5c and the rear flange 6 is a rear lower bent portion 6a, while the boundary portion 7a between the front vertical side portion 5b and the front flange 7 is linear, The bent part is not formed. The boundary portion 7 a is in contact with the front end corner portion 10 b ′ of the hinge rein hose 10.

The rear flange 6 is fixed to the fender bracket mounting portion 10b of the hinge rein hose 10 by spot welding, and the front flange 7 is fixed to the vertical wall portion 10c of the hinge rein hose 10 by spot welding.

  The impact load absorption process in this embodiment will be described with reference to FIGS. FIG. 6 conceptually shows the buckling process of the fender bracket 4 in this embodiment, and does not represent the actual dimensional relationship of each part.

As described above, at the time of a collision with a pedestrian, usually, the pedestrian tends to enter the fender not from right above the vehicle but obliquely upward from the front of the vehicle, and this impact load causes the fender bracket to buckle toward the rear of the vehicle. try to. Therefore, in the conventional structure in which the front flange is bent forward at the lower end of the front vertical side of the fender bracket and the front flange is welded and fixed to the upper surface of the cowl side member, the front vertical side easily buckles and collides. It was difficult to increase the initial load (reaction force) G1 ′, and eventually there was a problem that the load in the latter half of the collision became higher than necessary.

In contrast, in the present embodiment, as shown in FIG. 6A, the front vertical side portion 5b located on the vehicle front side of the fender bracket 4 is provided with bent portions 5d and 5f at the top and midway thereof. The front flange 7 extending downward from the lower end of the front vertical side 5b is formed. Therefore, when the impact load F due to the colliding object W acts, the front vertical piece 5b does not buckle immediately (see FIG. 6B), and as shown by the solid line in FIG. Reaction force) Easy to control in the direction of increasing G1.

On the other hand, since the front flange 7 is fixed to the vertical wall portion 10c of the hinge rein hose 10 constituting a part of the cowl side member 3, in the middle of the collision, the boundary portion with the front vertical side portion 5b of the front flange 7 7a is strongly pressed against the front end corner portion 10b 'of the hinge rein hose 10, whereby a ridge line 7a' is generated in the front flange 7, and buckling starts stably from the ridge line 7a '(FIG. 6 ( In the later stage of the collision, the fender bracket 4 is completely buckled (see FIG. 4D). As a result, the late load G2 is lower than the conventional load G2 ′.

In this way, in this embodiment, it is easy to control in the direction of increasing the load at the initial stage of collision, and the buckling start timing in the middle of the collision is easy to control by the thickness of the bracket, etc., so as shown by the solid line in FIG. The initial load G1 can be increased, and the late load G2 can be decreased. As a result, the pedestrian protection performance can be improved.

Further, since the pedestrian protection performance can be improved simply by extending the front flange 7 of the fender bracket 4 as it is from the front vertical side portion 5b, there is no problem that the structure becomes complicated and the weight and cost increase. .

Furthermore, the front vertical side portion 5b located on the vehicle front side of the fender bracket 4 has the bent portions 5d and 5f only at the top portion and the middle portion, and has no bent portion at the front flange portion. Compared with the conventional structure which also has a bending part in a part, the hand pushing rigidity at the time of normal use can be improved.

  In the above-described embodiment, the vertical wall portion 10c of the hinge rein hose 10 is bent substantially vertically downward from the fender bracket mounting portion 10b, and the front flange 7 of the fender bracket 4 also extends substantially vertically downward. The present invention can also be applied to the case where the vertical wall portion 10c forms an acute angle or an obtuse angle with respect to the fender bracket mounting portion 10b. In short, the front flange 7 is the lower end portion of the front vertical side portion 5a of the fender bracket 4. It may be formed so as to extend as it is along the vertical wall portion.

DESCRIPTION OF SYMBOLS 1 Front vehicle body 2 Engine room 3 Cowl side member 4 Fender bracket 5a Top side part 5b, 5c Front, rear vertical side part 5d, 5e Front, rear corner bending part 5f, 5g Middle bending part 5 Bracket body 6 Rear flange 7 Front flange 10b Fender bracket mounting part (upper wall surface of cowl side member)
10c Vertical wall (front wall)
11 Fender

Claims (1)

In the front body structure of an automobile in which a fender bracket is fixed on a cowl side member constituting the side wall of the engine room, and the fender is attached to the fender bracket.
The fender bracket has a top side portion, front and rear vertical side portions, and a bent portion in the middle of the front side, front corner portion and front and rear vertical side portions between the top side portion and the front and rear vertical side portions. A bracket body having a rear flange bent from the lower end portion of the rear vertical side portion to the rear of the vehicle, and a front flange extending downward from the lower end portion of the front vertical side portion as viewed from the side of the vehicle. The cowl side member has a substantially hexagonal shape,
2. The vehicle body structure according to claim 1, wherein the rear flange is fixed to the upper wall surface of the cowl side member, and the front flange is fixed to the front wall surface of the cowl side member.

Images