JP7210104B2 - vehicle front structure - Google Patents

Description

The present invention relates to a vehicle front structure such as an automobile.

As a specific example of the vehicle front structure, there is a structure shown in simplified form in FIG.
In this structure, a pair of left and right front side members 1e extending in the vehicle front-rear direction are provided as vehicle body frame members, positioned on both sides in the vehicle width direction of the front portion of the vehicle. Front end faces 12 (front end faces of the crash box 1B) of the pair of front side members 1e are connected to both ends of a cross member 4e extending in the vehicle width direction as a front bumper reinforcement. is bridge-connected between the front side members 1e of the (see, for example, Patent Document 1).
According to such a configuration, when a frontal collision of the vehicle occurs, the collision load Fa input to the cross member 4e is received by the pair of left and right front side members 1e, respectively, so that the impact can be absorbed. Become.

However, the prior art described above has room for improvement as described below.

That is, the cross member 4e is attached to the front side member 1e in a state in which both ends of the cross member 4e are in contact with the front end surface 12 of the front side member 1e. Here, the front end face 12 has a substantially rectangular shape when viewed from the front of the vehicle, and has two upper and lower corner portions 13e on the inner side in the vehicle width direction and the other two corner portions (no reference numerals) on the outer side in the vehicle width direction. ing. On the other hand, when a collision load Fa is applied to the cross member 4e, the cross member 4e is designed such that the central portion of the cross member 4e in the vehicle width direction is located on the vehicle rear side with respect to the front end surface 12 of the front side member 1e. Bending deformation occurs. As a result, the edge of the corner portion 13e strongly presses against the portion of the cross member 4e corresponding to the corner portion 13e on the inner side in the vehicle width direction, and the cross member 4e is damaged, and this damage progresses. As a result, the cross member 4e may be separated. As a result, the impact absorption performance is degraded.
As means for preventing such a risk, it is conceivable to form the cross member 4e into a highly rigid closed cross-sectional structure by using a plurality of metal plates. However, adopting such a means causes an increase in weight and an increase in manufacturing cost. Therefore, when the cross member 4e as a whole or a main portion thereof is formed using only one sheet of metal plate, the risk of damage to the cross member 4e in the event of a frontal collision of the vehicle as described above should be avoided. is desired.

JP 2009-234336 A

SUMMARY OF THE INVENTION The present invention has been devised in view of the circumstances described above. An object of the present invention is to provide a vehicle front structure capable of appropriately preventing or suppressing the risk of deterioration in shock absorption performance.

In order to solve the above problems, the present invention takes the following technical means.

A vehicle front structure provided by the present invention includes a pair of left and right front side members provided on both sides in the vehicle width direction of a vehicle front portion and extending in the vehicle front-rear direction; a cross member bridge-connected between the pair of front side members in a state where both ends in the vehicle width direction are in contact with each other, and at least each of the ends is formed in a single plate shape, The front end face of each of the front side members has a corner portion on the inner side portion in the vehicle width direction when viewed from the front of the vehicle, and a ridge line on the inner side in the vehicle width direction extends from the corner portion in the vertical height direction . In the vehicle front structure, the cross member is partially provided at a portion corresponding to the corner portion, and the portion corresponding to the corner portion is separated from the corner portion in the vehicle front-rear direction. , the convex bead portion bulges toward the vehicle front side from the peripheral portion, and the convex bead portion extends at an oblique angle with respect to the ridge line when viewed from the front of the vehicle. The middle portion of the convex bead portion in the longitudinal direction overlaps the corner portion, while the one longitudinal end portion of the convex bead portion is positioned inward of the ridgeline in the vehicle width direction. , which is located closer to the center in the vertical height direction of the ridgeline than the corner portion, and the other longitudinal end portion of the convex bead portion is located on the outer side in the vehicle width direction of the ridgeline, and the front end surface It is characterized in that it is arranged to protrude above or below the

According to such a configuration, the following effects are obtained.
First, a portion of the cross member corresponding to the corner portion of the vehicle width direction inner side portion of the front end surface of each front side member is provided with a convex bead portion. Since it is in a non-contact state separated in the longitudinal direction of the vehicle, when a frontal collision of the vehicle occurs and the collision load is input to the cross member, the cross member strongly presses against the edge of the corner portion, unlike the conventional technology. It is possible to avoid it. As a result, even though both ends of the cross member are in the form of a single plate, the portions corresponding to the corner portions of the cross member are prevented from being easily damaged, thereby preventing the cross member from being broken. Therefore, it is possible to appropriately obtain impact absorption performance using the cross member.
Secondly, the presence of the convex bead portion can increase the rigidity of the cross member at the portion corresponding to the corner portion. As a result, it is possible to more effectively prevent damage to predetermined portions of the cross member in the event of a frontal collision of the vehicle.
Thirdly, at least both ends of the cross member in the vehicle width direction are formed in a single plate shape, so that the number and weight of the entire cross member can be reduced. In addition, the convex bead portion may be of small size and can be easily formed on the cross member by press working. Therefore, it is possible to favorably promote reduction in vehicle weight, reduction in manufacturing cost, and the like.

Other features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.

1(a) is a schematic perspective view of a main part showing an example of a vehicle front structure according to the present invention, and FIG. 1(b) is an exploded schematic perspective view of a main part of FIG. 2(a) is a schematic front view of a main part showing front end surfaces (crash boxes) of a cross member and a front side member of the vehicle front structure shown in FIG. 1, and (b) is a IIb-IIb cross section of (a). FIG. 4C is a cross-sectional view taken along line IIc-IIc of FIG. FIG. 2 is a schematic plan view of essential parts of a cross member and a pair of front side members of the vehicle front structure shown in FIG. 1; (a) and (b) are schematic front views of essential parts showing another example of the present invention, and (c) is a schematic front view of essential parts showing another example of the vehicle front structure . (a) is a principal part plan view which shows an example of a prior art typically, (b) is a principal part front view of (a).

Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

A vehicle front structure A shown in FIG. The cross member 4 is provided with a pair of convex bead portions 42, which will be described later.

The pair of front side members 1 are vehicle body constituent members that are provided on both sides in the vehicle width direction of the front portion of the vehicle and extend in the vehicle front-rear direction so as to be positioned on both left and right sides of the engine room. Each front side member 1 has a configuration in which a crash box 1B is joined to a front portion of a side member main body portion 1A. In this embodiment, the crash box 1B is a constituent member of the front side member 1, It corresponds to the front end of the side member 1 . The side member main body portion 1A has a closed cross-section structure in which a flat plate-like member 11 is welded to the side surface of a cross-sectional hat-shaped member 10 extending in the longitudinal direction of the vehicle, for example. The crash box 1B has a substantially rectangular parallelepiped shape with a hollow interior, and a front end face 12 thereof has a substantially rectangular shape when viewed from the front, and serves as a mounting surface for the cross member 4 .

The radiator support 3 is arranged between the front ends of the pair of front side members 1 . This radiator support 3 is the same as the one known in the prior art, and includes a pair of outer supports 30 which are welded or bolted to the pair of front side members 1 and stand up in the vertical direction. A lower support 31 for mounting the radiator 5 mounted thereon, and an upper support 32 connected to bridge the upper ends of the pair of outer supports 30 and for fixing the upper part of the radiator 5 are provided.

The cross member 4 is a reinforcement for the front bumper, and has a single-plate shape formed entirely by pressing a single metal plate. ing. However, in the present embodiment, as shown in FIG. 3, the cross member 4 is bent or curved in a plan view, and the cross member 4 is attached to the front side member 1 at both ends 40 in the vehicle width direction. These intermediate portions 41 (portions near the center) protrude toward the front of the vehicle by an appropriate dimension La.

As indicated by reference numeral Na in FIG. 1(b), the cross member 4 has a hat-shaped cross section at each portion in the vehicle width direction to increase rigidity. An intermediate portion 41 of the cross member 4 in the vehicle width direction has a vertical width smaller than that of both end portions 40. This prevents the cross member 4 from obstructing the area of the radiator 5 in front of the vehicle to a large extent. This is effective in increasing the amount of air blown to the radiator 5 .
The cross member 4 is attached to the front side member 1 so that the rear surfaces of both ends 40 of the cross member 4 are in contact with the front end surface 12 of the crash box 1B. Both ends 40 are fastened to the crash box 1B using holes 48 and 18 and fastening members 9 such as bolts inserted through them (see also FIGS. 2(b) and 2(c)). .

The convex bead portion 42 is a part of the cross member 4 that is press-formed so as to bulge forward of the vehicle from its peripheral portion. In the vehicle front view shown in a), of the two upper and lower corner portions 13a and 13b on the vehicle width direction inner side of the front end surface 12 of the crash box 1B, the upper corner portion 13a is located on the vehicle front side. As shown in FIG. 4(b), the convex bead portion 42 is formed at a portion of the cross member 4 corresponding to the corner portion 13a (at the corner portion 13a) so that the cross member 4 does not come into contact with the corner portion 13a. The facing area and its neighboring area) bulge toward the front of the vehicle. In addition, the convex bead portion 42 is a substantially elongated obliquely inclined portion 42b so that the vehicle width direction inner portion 42b is lower in height than the vehicle width direction outer portion 42a when viewed from the front of the vehicle in FIG. It is considered to be a shape. As a result, the convex bead portion 42 extends in an oblique direction with respect to the ridgeline 12a (longitudinal piece) on the inner side in the vehicle width direction of the front end face 12 of the crash box 1B.

In this embodiment, the convex bead portion 42 is provided only at a portion corresponding to the upper corner portion 13a, and is not provided at a portion corresponding to the lower corner portion 13b. This is because, as shown in FIG. 2(a), the intermediate portion 41 of the cross member 4 of this embodiment is biased to a position higher than the mounting center line CL of the crash box 1B by an appropriate dimension Ha. When a load is applied to the intermediate portion 41, the portion of the cross member 4 corresponding to the lower corner portion 13b is subjected to a greater stress than the portion corresponding to the upper corner portion 13a. because there is no

Next, the operation of the vehicle front structure A will be described.

When a frontal collision of the vehicle occurs and a collision load is input to the intermediate portion 41 of the cross member 4 from the front side of the vehicle, as shown in FIG. A force Fb is generated which tends to deform a region on the vehicle width direction inner side of the portion attached to the vehicle toward the vehicle rear side. On the other hand, since the cross member 4 is provided with the convex bead portion 42 and the corner portion 13a and the cross member 4 are separated from each other, the bending deformation of the cross member 4 starts from the point corresponding to the corner portion 13a. This prevents the edge of the corner portion 13a from coming into strong pressure contact with the cross member 4. As shown in FIG. Therefore, it is possible to prevent the portion of the cross member 4 corresponding to the corner portion 13a from being easily damaged. In addition, since the convex bead portion 42 is provided at the portion corresponding to the corner portion 13a of the cross member 4 to increase the rigidity, the risk of damage to that portion is more appropriately prevented. .

Furthermore, in this embodiment, as described with reference to FIG. It also produces an effect of changing the direction of the stress generated in the portion corresponding to the convex bead portion 42 of the cross member 4 . As a result, the edge of the convex bead portion 42 is more thoroughly prevented from coming into strong pressure contact with the cross member 4 .

In the present embodiment, as described with reference to FIG. 3, the intermediate portion 41 of the cross member 4 is positioned closer to the front side of the vehicle than the both end portions 40, and originally, the front collision of the vehicle is prevented. When generated, the force Fb shown in FIG. 2(b) tends to increase. In addition, since the cross member 4 has a single plate shape, it has a lower overall strength than a cross member of a type that employs a closed cross-section structure using a plurality of plate materials.
In contrast, according to the present embodiment, it is possible to appropriately prevent a portion (both ends 40) of the cross member 4 from being easily damaged in the event of a frontal collision of the vehicle. It is possible to appropriately prevent the problem that the cross member 4 is divided due to breakage. As a result, it is possible to appropriately transmit the load from the cross member 4 to the front side member 1 and obtain excellent impact absorption performance.

Regarding the portion of the cross member 4 corresponding to the corner portion 13b on the lower side of the front end surface 12 of the crash box 1B, as described above, the intermediate portion 41 is located above the mounting center line CL of the crash box 1B by the dimension Ha. Due to the biased arrangement in the higher position, the stress is not as large as that on the upper corner portion 13a side. Therefore, in this embodiment, the portion corresponding to the lower corner portion 13b is not easily damaged.

Since the cross member 4 is made entirely of a single plate, it is possible to reduce the number of constituent members of the cross member 4 as a whole, thereby reducing the weight of the vehicle and the manufacturing cost. Moreover, since the projecting bead portion 42 may be of a small size and can be easily formed on the cross member 4 by press working, it does not hinder vehicle weight reduction and manufacturing cost reduction.

FIG. 4 shows another embodiment of the present invention (except for FIG. 4(c)) . In the figure, elements identical or similar to those in the above embodiment are denoted by the same reference numerals as those in the above embodiment, and repeated explanations are omitted.

In the embodiment shown in FIG. 4A, convex bead portions 42 and 42A are formed on the cross member 4 at locations corresponding to the upper and lower corner portions 13a and 13b of the front end face 12 of the crash box 1B. are provided respectively. Such a configuration is preferable when the height of the intermediate portion 41 of the cross member 4 in the vehicle width direction is substantially aligned with the center line CL of attachment to the crash box 1B.

In the embodiment shown in FIG. 4(b), a convex bead portion 42A is provided only at a portion of the cross member 4 corresponding to the lower corner portion 13b of the front end surface 12 of the crash box 1B. Such a configuration is preferable when the height of the intermediate portion 41 of the cross member 4 in the vehicle width direction is lower than the attachment center line CL to the crash box 1B by an appropriate dimension Hb.

In the embodiment shown in FIG. 4C, the longitudinal direction of the convex bead portion 42 is substantially horizontal. By tilting the convex bead portion 42 obliquely, as described above, it is possible to change the direction of the stress generated at the formation location of the convex bead portion 42 and its peripheral portion .

The invention is not limited to the content of the embodiments described above. The specific configuration of each part of the vehicle front structure according to the present invention can be modified in various ways within the intended scope of the present invention.

As can be understood from the embodiment shown in FIGS. 1 to 3 and FIGS. 4(a) and (b), in the present invention, the corner portion of the front end face 12 of the front side member 1 on the inner side in the vehicle width direction is , When there are two upper and lower corner portions 13a and 13b, it is preferable to provide the convex bead portion 42 or 42A corresponding to the corner portion on the side where a large stress is likely to be generated in the event of a frontal collision of the vehicle, but the present invention is not limited to this. . According to the configuration in which the convex bead portion 42 or 42A is provided so as to correspond to either one of the upper and lower corner portions 13a and 13b, compared with a configuration in which such a convex bead portion 42 or 42A is not provided. , the effect of suppressing damage to the cross member 4 can be obtained.

The cross member may have a single plate shape at least at both ends in the vehicle width direction, and other portions, such as the intermediate portion, may have a multi-layer structure (including, for example, a closed cross-section structure) of plate materials. may In addition, it is of course possible to adopt a configuration in which accessory parts other than the plate material are additionally provided.
A crash box is preferably provided in the front portion of the front side member, but instead of the crash box, another member may be provided, or such a member may not be provided. For example, in the front end portion of the side member body portion 1A of the front side member 1 of the above-described embodiment, a suitable member different from the crash box is used to provide a front end surface 12 as a mounting surface, and the cross member 4 is attached to this portion. A direct-mounted configuration is also possible.

A Vehicle front structure 1 Front side member 12 Front end faces 13a, 13b Corner part (front end face)
4 cross member 42 convex bead portion

Claims (1)

a pair of left and right front side members provided on both sides in the vehicle width direction of the vehicle front portion and extending in the vehicle front-rear direction;
Both ends in the vehicle width direction are in contact with the front end faces of the pair of front side members, and are bridged between the pair of front side members, and at least each of the ends is formed in a single plate shape. and a cross member
and
The front end face of each of the front side members has a corner portion on the inner side portion in the vehicle width direction when viewed from the front of the vehicle, and a ridge line on the inner side in the vehicle width direction extends from the corner portion in the vertical height direction . A vehicle front structure,
The cross member is partially provided at a portion corresponding to the corner portion, and is located on the front side of the vehicle relative to the peripheral portion so as to separate the portion corresponding to the corner portion from the corner portion in the vehicle front-rear direction. It further comprises a convex bead portion that bulges to the
When viewed from the front of the vehicle, the convex bead portion extends at an oblique angle with respect to the ridgeline, and a longitudinal middle portion of the convex bead portion overlaps the corner portion. One end in the longitudinal direction of the convex bead portion is positioned inward of the ridgeline in the vehicle width direction and closer to the center of the ridgeline in the vertical height direction than the corner portion, and the convex bead portion The other end in the longitudinal direction of the is located on the outer side in the vehicle width direction of the ridgeline and protrudes above or below the front end face .

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