JP7667705B2 - Front body structure - Google Patents

Description

The present invention relates to a vehicle front body structure that efficiently absorbs impact loads caused by small overlap collisions.

Technological development has been progressing to improve the collision safety of vehicles, particularly automobiles. In particular, there has been growing interest in collision safety in small overlap (SOL) collisions, which have a smaller overlap amount than conventional offset collisions.

An SOL collision is an offset collision that occurs on the vehicle widthwise outer side of a pair of left and right main frames (front side frames) that extend in the fore-and-aft direction of the vehicle body. As a countermeasure against this SOL collision, for example, Patent Document 1 (Patent Publication No. 6339838) discloses a technology in which the rear of a gusset is fixed to the outer side of the main frame in the vehicle width direction, the front of the gusset is expanded in diameter outward to the left and right and extends forward, and the front end of the gusset and the front end of a crash box connected to the front end of the main frame are joined to the back of the bumper beam.

According to the technology disclosed in this document, when the bumper beam is subjected to a side-on collision, the impact load is transmitted to the main frame via the gusset, and the main frame is bent and deformed inward in the vehicle width direction to absorb the impact load.

Patent No. 6339838

However, with the technology disclosed in this document, the impact load during an SOL collision is only transmitted to the main frame from the diagonal front via the gusset, making it difficult to efficiently transmit the impact load to the main frame and resulting in a defect in which the impact load cannot be efficiently absorbed.

The present invention aims to provide a vehicle front structure that can efficiently transmit the impact load during a small overlap collision to the main frame and efficiently absorb the impact load.

The present invention relates to a vehicle front structure having a main frame provided on both sides of the vehicle width direction and extending in the front-rear direction of the vehicle body, a crash box provided on the front side of the main frame and having a lower crush strength in at least the front-rear direction of the vehicle body than the main frame, a bumper beam extending in the width direction of the vehicle body and having a front end of the crash box engaged at its back, a gusset whose rear part is fixed to the outer surface of the main frame in the width direction of the vehicle body and whose front part extends forward at an incline outward in the width direction of the vehicle body, and a connecting member that engages with the main frame, the crash box, and the gusset, the connecting member comprising a connecting portion interposed between the front end of the main frame and the rear end of the crash box and engaging both ends, a gusset front member extending from the connecting portion toward the front of the vehicle body and abutting or joining to the back surface of the bumper beam, and an engaging portion that engages the outer surface of the gusset in the width direction of the vehicle body with the connecting portion.

According to the present invention, the connecting member is composed of a connecting portion, a gusset front member, and an engaging portion, the connecting portion engages between the front end of the main frame and the rear end of the crash box, the gusset front member extending from this connecting portion toward the front of the vehicle body is abutted or joined to the back surface of the bumper beam, and further, the engaging portion engages the outer surface of the gusset in the width direction of the vehicle body with the connecting portion, so that the impact load during a small overlap collision can be transmitted from the gusset front member to the main frame via the engaging portion and the gusset, and can also be transmitted from the connecting portion to the main frame. As a result, the impact load can be efficiently transmitted to the main frame and efficiently absorbed by this main frame.

FIG. 1 is a plan view of a front portion of a vehicle body according to a first embodiment; A plan view showing the state in which the bumper beam collided with the barrier in a small overlap manner. Enlarged view of the bumper FIG. 3 is a front perspective view of a main part of the bumper of the first embodiment. FIG. 3 is a rear perspective view of a main portion of the bumper of the first embodiment. FIG. 3 is an upper left perspective view of a main part of the bumper of the first embodiment. FIG. 4 is an enlarged view of a main part according to a second embodiment, which corresponds to FIG.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
[First embodiment]
A first embodiment of the present invention is shown in Figures 1 to 6. Reference numeral 1 in Figure 1 denotes a vehicle body, and in the figure, the front part of the vehicle body 1 is shown. In the front part of this vehicle body 1, a pair of left and right main frames (front side frames) 2 are arranged on both sides of an engine room 4 that houses an engine 3, sandwiching the engine 3 therebetween. Furthermore, the rear part of the main frames 2 extends to the underside of the front half of a floor panel 5.

The engine 3 is a vertically mounted type, and is supported via a pair of engine mounts (neither shown) on a suspension cross member that is installed between the left and right main frames 2.

A transmission 6 is connected to the rear of the engine 3, and the rear of the transmission 6 is housed in a floor tunnel 5a formed in the floor panel 5. Furthermore, the lower parts of the A-pillars 7 are joined to both sides of the floor panel 5 in the vehicle width direction, and front wheels 8 are disposed in wheel houses (not shown) provided on both outer sides of the main frame 2 in the vehicle width direction.

A bumper beam 11 extending in the vehicle width direction is disposed at the front end of the vehicle body 1. Furthermore, the front end of a crash box 12, which is in front of the main frame 2 and has a lower crush strength in the front-rear direction of the vehicle body 1 than the main frame 2, is fixed to the back of the bumper beam 11. A plate-shaped connecting portion 13a provided on a connecting member 13 is interposed between the rear end of the crash box 12 and the front end of the main frame 2, and the rear end of the crash box 12, the front end of the main frame 2, and the connecting portion 13a are fastened together via a bolt. These may also be joined by welding.

The bumper beam 11 is formed with an offset portion 11a that protrudes outward in the vehicle width direction beyond the main frame 2, and the end direction of this offset portion 11a is curved toward the rear of the vehicle body 1. Although not shown, an impact absorbing member is disposed in front of this bumper beam 11, and this impact absorbing member is covered by the bumper face.

A gusset 14 is disposed on the outer side of the main frame 2 in the vehicle width direction. This gusset 14 directly transmits the impact load during a SOL collision to the main frame 2, and has a fixed portion 14b formed at the rear end of a main body portion (hereinafter referred to as the "gusset body") 14a formed with a square cylindrical cross section. This fixed portion 14b is fixed by bolting or welding to the outer side of the vehicle width direction of the main frame 2 located forward of the center of the engine 3 in the fore-and-aft direction. Since this gusset body 14a directly transmits the impact load F to the main frame 2, its crush strength in the extension direction is set to be relatively high.

As shown in FIG. 3, the base of the gusset body 14a is inclined from the fixed portion 14b toward the outside in the vehicle width direction, and the front end of the gusset body 14a is almost flush with the front end of the main frame 2 or extends to a position slightly set back, and is formed in a surface parallel to the front end of the main frame 2. Furthermore, a lateral stop surface 14c is formed on the outside of the front end of the gusset body 14a. This lateral stop surface 14c has a predetermined opening angle θg with respect to the inclination of the gusset body 14a.

The connecting portion 13a of the connecting member 13, which is fastened together between the main frame 2 and the crash box 12, extends from the front end of the gusset body 14a. As shown in FIG. 1, the connecting member 13 is composed of the connecting portion 13a, the plate-shaped engaging portion 13b, and the gusset front member 13c.

The engaging portion 13b extends from the outer end of the connecting portion 13a in the vehicle width direction to the outside of the gusset body 14a at a substantially right angle, abuts against the lateral stop surface 14c, and is fixed to this lateral stop surface 14c by bolting or welding. Therefore, the opening angle θg of the lateral stop surface 14c is formed at an angle at which the engaging portion 13b abuts (an angle perpendicular to the front end).

Furthermore, the gusset front member 13c has a plate-shaped front frame portion 13d and a frame reinforcement member 13e. The front frame portion 13d extends from the outer end of the connecting portion 13a almost on an extension line of the outer surface of the gusset body 14a. The rear end of the frame reinforcement member 13e abuts against the connecting portion 13a, and the outer surface in the vehicle width direction is integrally fixed to the front frame portion 13d by bolting or welding.

The rear end of the frame reinforcement member 13e is formed in approximately the same shape as the gusset body 14a. The front end has a contact surface that is wider than the rear end and is formed flush with the front end face of the front frame portion 13d, and the front end of the front frame portion 13d and the front end of the frame reinforcement member 13e form the front end 13f of the gusset front member 13c. This front end 13f is then abutted against or joined to the back surface of the bumper beam 11.

The connecting portion 13a, the engaging portion 13b, and the front frame portion 13d, which are formed in a roughly Y-shape in plan view, may be integrally formed by bending or welding a steel plate or other plate material, or may be extrusion molded products.

The frame reinforcement member 13e is a molded part made of, for example, an aluminum alloy, and its strength in the front-rear direction is adjusted in advance by forming a hollow portion (not shown). The symbol Bo is an offset barrier that imitates an object of a single-side collision, such as an opposing vehicle, a standing tree, or a utility pole.

Next, we will explain the behavior of the vehicle body 1 with this configuration when it experiences a side-on collision. When the offset portion 11a of the bumper beam 11 provided at the front end of the vehicle body 1 approaches the offset barrier Bo (see Figure 1) and a side-on collision occurs, an impact load F, which is the reaction force, is applied to the offset portion 11a.

Then, this impact load F causes the offset portion 11a to deform toward the rear of the vehicle body 1, pressing against the front end 13f of the gusset front member 13c, which is a component of the connecting member 13. The front end 13f has a wider contact surface than the rear end, so it can more effectively withstand the impact load F. In addition, because the gusset front member 13c is formed by fastening the frame reinforcing member 13e to the plate-shaped front frame portion 13d, the area of the front end 13f and its strength in the fore-and-aft direction can be freely adjusted by shaping the frame reinforcing member 13e.

The impact load F applied to the gusset front member 13c is transmitted to the connecting portion 13a. This connecting portion 13a is fixed to the front end of the main frame 2, and the engaging portion 13b formed at its end is fixed to the lateral stop surface 14c (see Figures 3 and 5) formed on the outer surface of the gusset body 14a. Therefore, the impact load F from the gusset front member 13c is branched and transmitted in two directions, to the main frame 2 and the gusset body 14a, via the connecting portion 13a and the engaging portion 13b.

Furthermore, the front frame portion 13d of the gusset front member 13c is disposed on a line extending from the outer surface of the gusset body 14a. Therefore, the vector direction of the impact load F from the gusset front member 13c to the gusset body 14a is approximately the same as the extension direction of the gusset body 14a. Therefore, the impact load F can be efficiently transmitted to the gusset body 14a. The impact load applied to the gusset body 14a is transmitted from the fixing portion 14b formed at the base to the main frame 2, and presses the main frame 2 diagonally from the outside to the inside in the vehicle width direction.

At that time, because the engagement portion 13b is fixed to the lateral stop surface 14c of the gusset body 14a, the front end side of the gusset body 14a does not open outward when subjected to the impact load F, and the impact load F can be reliably transmitted to the main frame 2.

As a result, as shown in FIG. 2, in the event of a collision at the rear, the load transmitted obliquely from the gusset 14 to the outside of the main frame 2 presses the main frame 2 toward the engine 3, and the load from the front end of the main frame 2 causes it to be further curved and deformed, allowing the impact load F to be efficiently absorbed.

In this manner, in this embodiment, the impact load F at the time of an SOL collision is branched and transmitted in two directions, to the main frame 2 side and the gusset 14 side, by the connecting member 13. This not only enables the load F to be transmitted efficiently to the main frame 2, but also enables the impact load F to be efficiently absorbed by the deformation of the main frame 2.
[Second embodiment]
A second embodiment of the present invention is shown in Fig. 7. Since the components other than the connecting member 21 are the same as those in the first embodiment, the same reference numerals are used and the description will be omitted or simplified.

In the first embodiment described above, the gusset front member 13c formed on the connecting member 13 is composed of a front frame portion 13d and a frame reinforcing member 13e, which are formed separately. In contrast, in this embodiment, the entire connecting member 21 is an integrally molded product formed by extrusion molding, die casting, casting, or the like. Metal materials such as aluminum alloys and steel are used as the material.

The connecting member 21 in this embodiment is composed of a connecting portion 21a, an engaging portion 21b, and a gusset front member 21c, and the connecting portion 21a is fastened together with the front end of the main frame (front side frame) 2 and the rear end of the crash box 12 by a bolt.

The engagement portion 21b extends from the outer end of the connecting portion 21a toward the rear of the vehicle body 1 at a substantially right angle and is fixed to the lateral stop surface 14c formed on the gusset body 14a by bolting or welding. Furthermore, the gusset front member 21c extends forward from the outer end of the connecting portion 21a.

The front end 21d of the gusset front member 21c abuts or is joined to the back surface of the bumper beam 11. Furthermore, a line connecting the center of the width between the rear end and the front end 21d of the gusset front member 21c is disposed on a line extending from the outer surface of the gusset body 14a. In addition, the front end 21d of the gusset front member 21c has a contact surface that is wider than the rear end.

Furthermore, a hollow portion 21f is formed in the gusset front member 21c, penetrating the vehicle body 1 in the vertical direction. This hollow portion 21f is for adjusting the resistance of the gusset front member 21c when a SOL collision occurs, and providing the hollow portion 21f makes it possible to reduce weight. In addition, a hollow portion 21g for adjusting resistance is also formed in the connecting portion 21a, penetrating the vehicle body 1 in the vertical direction.

In this configuration, as in the first embodiment, when the offset portion 11a of the bumper beam 11 collides with the offset barrier Bo, the reaction force, the impact load F, is applied to the offset portion 11a, and the front end portion 21d of the gusset front member 21c formed on the connecting member 21, which is in contact with or joined to the back surface of the offset portion 11a, is pressed. This front end portion 21d is in contact with or joined to the back surface of the bumper beam 11 with a wide contact surface, so it can more effectively receive the impact load F.

The impact load F applied to the gusset front member 21c is branched and transmitted in two directions, to the main frame 2 side and the gusset body 14a side, by the connecting portion 21a and the engaging portion 21b. At that time, the center of the gusset front member 21c in the vehicle width direction is disposed on an extension line of the outer surface of the gusset body 14a. Therefore, the vector direction of the impact load F from the gusset front member 21c is the extension direction of the gusset body 14a, so that the impact load can be transmitted efficiently. Then, as in the first embodiment described above, the impact load applied to this gusset body 14a and the impact load applied to the front end of the main frame 2 bend the main frame 2 toward the engine 3 to absorb the impact.

In this way, in this embodiment, by making the connecting member 21 a molded product, in addition to the effects of the first embodiment described above, it is possible to easily manufacture it, and the hollow portions 21f and 21g can achieve weight reduction.

The present invention is not limited to the above-described embodiment. For example, in the second embodiment, the hollow portions 21f and 21g of the connecting member 21 may be formed with temporary holes during manufacturing, and the opening area of the hollow portions 21f and 21g may be adjusted by post-processing.

1...Vehicle body,
2...Main frame (front side frame),
3…Engine,
4. Engine room,
5...Floor panel,
5a…Floor tunnel,
6...Transmission,
7...A pillar,
8…Front wheel,
11...Bumper beam,
11a...offset portion,
12...Crash box,
13, 21 ... connecting member,
13a, 21a...connection part,
13b, 21b...engaging portion,
13c, 21c... gusset front member,
13d...Front frame part,
13e...frame reinforcing member,
13f, 21d...front end,
14... Gusset,
14a... gusset body,
14b...fixed portion,
14c...side stop surface,
21f, 21g...Hollow part,
Bo: offset barrier,
F: Impact load,
θg…Opening angle

Claims (5)

a main frame provided on each side of a vehicle body in a width direction and extending in a front-rear direction of the vehicle body;
a crash box provided on the main frame on the vehicle body front side and having a crush strength weaker than that of the main frame in at least the vehicle body front-rear direction;
a bumper beam extending in a width direction of the vehicle body and having a rear surface to which a front end of the crash box is engaged;
a gusset having a rear portion fixed to an outer surface of the main frame in the width direction of the vehicle body and a front portion extending forward while being inclined toward the outer side in the width direction of the vehicle body;
A vehicle body front structure having a connecting member that engages with the main frame, the crash box, and the gusset,
The connecting member is
a connecting portion interposed between a front end portion of the main frame and a rear end portion of the crash box and engaging the two ends;
a gusset front member extending from the connecting portion toward the front of the vehicle body and abutting or joining to a back surface of the bumper beam;
a gusset having a widthwise outer surface of the vehicle body and an engagement portion that engages with the connecting portion; The connecting member is
The connecting portion and the engaging portion are integrally formed,
2. The vehicle front structure according to claim 1, wherein the engagement portion is angled with respect to an extending direction of the gusset. The front end of the gusset is disposed on the rear surface of the bumper beam and extends along an extension line of the gusset on the outer side of the width of the vehicle body, and the front end of the gusset has a contact surface that is wider than the rear end of the gusset and is in contact with or joined to the rear surface of the bumper beam. the gusset front member is formed by a frame portion extending substantially on an extension line of a wall portion of the gusset on the outer side in the width direction of the vehicle body, and a reinforcing member provided integrally with the frame portion on the inner side in the width direction of the vehicle body,
3. A vehicle front body structure according to claim 1, wherein the front end of the reinforcing member has a contact surface wider than the rear end thereof and is in contact with or joined to the rear surface of the bumper beam. 5. The vehicle front structure according to claim 1, wherein at least the gusset front member is formed with a hollow portion for adjusting drag that penetrates the vehicle body in the vertical direction.

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