JP2023022452A - Vehicle front part structure - Google Patents

Abstract

To provide a vehicle front part structure that can appropriately cope with a collision load input into a region above a front side member and that can provide excellent impact absorption performance and load bearing performance increased more than ever before so as to decrease an occupant injury value as much as possible.SOLUTION: A vehicle front part structure A includes: a pair of left and right front side members 3 including compressive deformable portions 30A; subframes 6 disposed on a vehicle back side of a lower portion of a front fixation member 5 in a region below the pair of front side members 3; and rear fixation members 85 fixed on the vehicle back side of an upper portion of the front fixation member 5 in a region above the pair of front side members 3. A connection member 2 for absorbing collision energy, which serves as a bridge between the upper portion of the front fixation member 5 and the rear fixation member 85 to connect therebetween is provided on a predetermined position in the upper region above the front side member 3.SELECTED DRAWING: Figure 1

Description

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

The present applicant has previously proposed the structure described in Patent Document 1 as an example of the vehicle front structure.
In the vehicle front structure described in the document, a pair of left and right front side members are provided as a vehicle body frame member in the front part of the vehicle. It is a part that allows compression deformation when it occurs. A frame-shaped radiator support (front side fixing member) is fixedly attached to the front end region of the pair of front side members. A subframe (cradle) that deforms when a frontal collision of the vehicle occurs is further provided at a position on the vehicle rear side of the lower portion of the radiator support in the lower region of the pair of front side members.

According to such a configuration, when a frontal collision of the vehicle occurs and the collision load is input from the front side of the vehicle to the front portion of the vehicle, the collision load is distributed and transmitted to the front side members and the subframe. . Also, collision energy is absorbed by the deformation of these parts. Therefore, it is possible to improve the shock absorbing performance and the load bearing performance (shock resistance performance) at the time of a frontal collision of the vehicle.

However, the prior art still has problems to be solved as described below.

First, in the event of a frontal collision of the vehicle, the barrier (collision target) not only rushes toward the front side member and the subframe below it, but also rushes into the area above the front side member. However, collision load may be input. On the other hand, in the prior art, it is difficult to effectively receive the impact load applied to the area above the front side member.
Second, when the collision load at the time of the frontal collision of the vehicle is considerably large, both the compressive deformation permissible portion of the front side member and the sub-frame become large in an extremely short period of time at the very beginning of the frontal collision of the vehicle. Since it is crushed, it is difficult to receive the collision load, and the load bearing performance at the very initial stage of the collision may be insufficient. When a vehicle occupant is protected by a seat belt, it is desired that the time required from the start of the occupant restraining action by the seat belt until the vehicle speed becomes zero is as long as possible. . On the other hand, if the load-bearing performance is insufficient at the very early stage of a collision, the required time will be shortened, and there is a risk that occupant injuries such as chest compressions will become worse.

JP 2020-158083 A JP-A-2004-98919 JP 2006-327371 A

SUMMARY OF THE INVENTION The present invention has been devised under the circumstances described above, and is capable of suitably responding to the impact load input to the upper region of the front side member and minimizing the occupant injury value as much as possible. Therefore, it is an object of the present invention to provide a vehicle front structure capable of improving impact absorption performance and load bearing performance even more than before.

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

The vehicle front structure provided by the present invention extends in the front-rear direction of the vehicle at intervals in the vehicle width direction in the front part of the vehicle, and the area near the front end has a predetermined or greater capacity when a front collision of the vehicle occurs. A pair of left and right front side members, which are compression deformation permissible portions that undergo compression deformation due to the input of a collision load, and a pair of front side members whose upper and lower portions protrude upward and downward, respectively, from the pair of front side members. a front side fixing member fixedly attached to a region near the front end of the front side member; a sub-frame that deforms when a front collision of the vehicle occurs and the lower portion of the front side fixing member moves backward; and a rear side fixing member fixedly attached to the pair of front side members so as to be located on the rear side of the vehicle, wherein At least a portion of the upper region is provided so as to overlap with the upper side of the sub-frame when viewed from the side of the vehicle, and bridges and connects an upper portion of the front side fixing member and the rear side fixing member, and It is characterized by further comprising a connecting member for absorbing collision energy, which deforms when the upper portion of the front fixing member retreats due to a frontal collision of the vehicle.

According to such a configuration, the following effects are obtained.
First, when a frontal collision of the vehicle occurs, the collision load can be received by the front side members and the sub-frame positioned below them, as in Patent Document 1, and in addition, the region above the front side members. The collision load input (barrier plunge) at 2 can be transmitted from the upper part of the front side fixing member to the rear side fixing member via the connection member for absorbing the collision energy and received. At that time, the collision energy can be absorbed by deforming the connecting member. Thus, according to the present invention, it is possible to effectively receive the input of the collision load to the area above the front side member. impact performance) can be improved.
Secondly, at the very early stage of a frontal collision of the vehicle, it is possible to effectively receive the collision loads of different heights by the front side members, the sub-frames, and the connecting members for absorbing collision energy. Therefore, it is possible to appropriately avoid insufficient load bearing performance at the very early stage of the frontal collision of the vehicle. As a result, the time from when a frontal collision occurs (when the occupant is restrained by the seatbelt) to when the vehicle speed drops to zero is longer than before, preventing or suppressing the worsening of occupant injury values due to chest compression, etc. It is possible to

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 is a schematic side view of a main part showing an example of a vehicle front structure according to the present invention; FIG. FIG. 2 is an enlarged schematic side view of a main portion of the vehicle front structure shown in FIG. 1; FIG. 2 is a schematic plan view of a main part of FIG. 1; FIG. 2 is a schematic bottom view of a main part of FIG. 1; FIG. 2 is a schematic perspective view of a main part of FIG. 1; (a) is a main part side view which shows typically the effect|action of the vehicle front part structure shown in FIG. 1, (b) is a main part top view of (a). FIG. 3 is a plan view of a main part showing another example of the operation of the vehicle front structure shown in FIG. 1;

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

A vehicle front structure A shown in FIGS. ), a radiator support 5, a suspension member 4, a pair of left and right subframes (cradles) 6, a moment canceller 85, and a connecting member 2 for absorbing collision energy.
Here, the radiator support 5 and the moment canceller 85 correspond to specific examples of the "front fixing member" and the "rear fixing member", respectively, in the present invention.

The vehicle front structure A of the present embodiment is characterized by a connection member 2 for absorbing collision energy and a configuration related to this, and the configuration other than this is the same as that of Patent Document 1. The description of the configuration similar to that of Patent Document 1 will be simplified.

The pair of front side members 3 has a pair of front portions 30 positioned on both sides in the vehicle width direction of the engine room 10 and extending in the vehicle front-rear direction. The portion 31 and the substantially horizontal rear extension portion 32 are connected in order. Although illustration is omitted, each front side member 3 is configured by using an inner hollow closed cross-section structural member having a hollow rectangular tubular shape or similar shape, for example.
In FIG. 1, reference numeral 12 denotes a dash panel that partitions the engine room 10 and the passenger compartment 11, and reference numeral 13 denotes a floor panel.

A region near the front end of the front portion 30 serves as a compression deformation allowance portion 30A that undergoes compression deformation when a frontal collision of the vehicle 1 occurs and a collision load exceeding a predetermined level is input. The compressive deformation allowance portion 30A has a structure in which a plurality of recessed grooves 33 (crash beads) extending in the vertical direction, for example, are provided at appropriate intervals on the side surface of the front portion 30, and the front collision of the vehicle 1 is prevented. When it occurs, it is compressed and deformed in a so-called bellows shape, and is more likely to be compressed and deformed than other regions of the front portion 30 .
A front bumper reinforcement 80 extending in the vehicle width direction is attached between the front ends of the pair of front portions 30 in a bridging manner.

The suspension member 4 extends in the vehicle width direction near the lower portion of the rearwardly downward inclined portion 31 of the front side member 3 as viewed from the side of the vehicle, and is supported by the front side member 3 . A lower arm 18 for supporting the front wheel 19 is attached to both ends of the suspension member 4 in the vehicle width direction, and a front side mounting portion J1 and a rear side mounting portion J2 are set for connection with the front side member 3. It is

Here, the front mounting portion J1 is configured such that the upper portion of an upright arm portion 41 provided in a region near the front portion of the suspension member 4 is fixedly connected to the front side member 3 via a support member 91 such as a bolt. configuration.
The rear attachment portion J2 is a portion where the rear portion of the suspension member 4 is fastened with bolts 92 to the lower wall portion of the bracket portion 35 welded to the lower surface side of the rear descending slope portion 31 . The rear attachment portion J2 also serves as a portion for connecting the rear portion of the suspension member 4 to the front portion of the bracket portion 36 whose rear portion is fixed to the rear extension portion 32 using the bolt 95. The two bracket portions 35 and 36, the rear portion of the suspension member 4, and the rubber bush 18a at the base end portion of the lower arm 18 are fastened together by bolts 92. As shown in FIG.
In FIG. 4 , reference numeral 17 denotes an outer torque box that bridges and connects the rocker 16 and the front side member 3 . Reference numeral 15 indicates a reinforcing member corresponding to the inner torque box.

The radiator support 5 includes a pair of left and right outer supports 50 that are joined to the front portions of the pair of front side members 3 and extend in the vertical direction, and an upper support 52 that is connected to the upper and lower ends of the pair of outer supports 50 in a bridging manner. and a lower support 51. A radiator 55 (not shown in the drawing) is mounted on the lower support 51 . Under the outer support 50, a flat block-shaped crash box 53 is provided which is compressed and deformed when a frontal collision of the vehicle 1 occurs and a predetermined or more compressive load is applied from the front side of the vehicle.

The sub-frame 6 is constructed using, for example, a rectangular pipe-shaped member, and is arranged directly below the front portion 30 of the front side member 3 and sandwiched between the crash box 53 and the suspension member 4 . provided and extending in the longitudinal direction of the vehicle. A rear end portion of the sub-frame 6 is connected to a front portion of the suspension member 4 via a connecting portion J3. The connecting portion J3 is configured such that the rear end portion of the sub-frame 6 enters an extension portion 44 projecting from the front portion of the suspension member 4 and has a U-shape when viewed from the side of the vehicle, and is fixed using bolts 93 . is.

The sub-frame 6 is formed in a V-shape when viewed from the side of the vehicle, and has a midway portion in the longitudinal direction of the vehicle supported by the front side member 3 via a bracket 7 and a connecting portion J4. The connecting portion J4 is a portion where the upper surface portion of the sub-frame 6 is fastened to the lower portion of the bracket portion 7 using bolts 94 . The upper portion of the bracket 7 is welded to the front side member 3, and is preferably located closer to the rear side of the vehicle than the compression deformation allowance portion 30A.

A front end portion 60 of the subframe 6 is set to face and approach the crash box 53 with a gap therebetween. Therefore, when a frontal collision of the vehicle 1 occurs and the crash box 53 retreats by a predetermined distance or more, the subframe 6 receives a pushing force (collision force) from the crash box 53 toward the rear side of the vehicle and deforms. Note that the sub-frame 6 is not limited to having a V-shape when viewed from the side, and may have a shape extending substantially straight in the horizontal direction, for example. In this embodiment, the front end portion 60 is a free end that is not connected to any part of the radiator support 5, but unlike this, for example, the front end portion 60 is connected to the crash box 53 by contacting it. can also be configured.

The moment canceller 85 essentially cancels the moment that tends to bend the front side member 3 upward when a front collision of the vehicle 1 occurs and a load is input from the front side of the vehicle. It is a part for improving the impact absorption performance of the vehicle 1 by promoting the compressive deformation of the member 3 (the compressive deformation permitting portion 30A). The moment canceller 85 is a panel-shaped member whose lower portion is connected to the vehicle rear side portion of the compression deformation allowance portion 30A of the front side member 3 and which stands up in the vertical direction. It is joined to a vehicle body component such as a cowl side panel (not shown). A suspension tower 88 (see FIG. 3) is provided inside the moment canceller 85 in the vehicle width direction.

The connecting member 2 for absorbing collision energy is, for example, a bar-shaped member made of metal, and bridges and connects the upper portion of the outer support 50 and the front portion of the moment canceller 85 in the upper region of each front side member 3 . is provided. Moreover, at least a portion of the connecting member 2 is arranged to overlap the upper side of the sub-frame 6 when viewed from the side of the vehicle. Front and rear brackets 25 and 26 are joined to the front and rear ends of the connecting member 2 (see also FIG. 5). The connection member 2 is attached by being bolted or welded to the moment canceller 85 .

The connecting member 2 is straight when viewed from the side of the vehicle. However, when viewed from above, the connecting member 2 has a straight front region 20a and a rear region 20b extending in the longitudinal direction of the vehicle, and an intermediate region 20c extending obliquely and straight. , a bending bar having two front and rear bending portions 21a and 21b (see FIG. 5). Therefore, when a frontal collision of the vehicle 1 occurs and the collision load is received from the front side of the vehicle, the connecting member 2 generates a resistance force against the collision load (strut force against the backward movement of the upper portion of the outer support 50). At the same time, bending deformation is generated starting from the positions of the bent portions 21a and 21b, thereby exhibiting an energy absorbing function. Preferably, the above-described bending deformation of the connecting member 2 ends at the same timing as the end of the compression deformation of the compression deformation permitting portion 30A of the front side member 3 when the front collision of the vehicle 1 occurs. It is said that

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

Since the upper part of the radiator support 5 and the moment canceller 85 are connected via the connecting member 2 during normal times when the front collision of the vehicle 1 does not occur, the rigidity of these series of parts is increased. In addition, since the sub-frame 6 supported by the front side member 3 is connected to the front side of the suspension member 4 via the bracket 7, the rigidity of these series of parts is also increased, and the suspension member 4 is stabilized. can be done.

When a frontal collision of the vehicle 1 occurs and a collision load larger than a predetermined amount is input to the front portion of the vehicle 1 from the front side of the vehicle, part of this collision load is input to the front side members 3. Received, the compression deformation permitting portion 30A is compressed and deformed. Further, another part of the collision load is input to and received by the sub-frame 6 through the crash box 53 of the radiator support 5, and the sub-frame 6 is also deformed. Further, another portion of the collision load is input to and received by the connecting member 2 from the upper portion of the radiator support 5, and the connecting member 2 is also deformed.

FIG. 6 shows an example of a case where the compressive deformation allowance portion 30A, the subframe 6, and the connecting member 2 are greatly deformed due to the collision load (corresponding to the middle and latter stages of the collision). ing. Such deformation of each part appropriately absorbs the collision energy and mitigates the impact received by the occupant. According to the vehicle front structure A of the present embodiment, it is possible to cause the connecting member 2 to receive the collision load acting on the region above the front side member 3 and to absorb the energy appropriately. Also, load transmission to the moment canceller 85 can occur. Therefore, it is possible to improve impact absorption performance and load bearing performance (shock resistance performance).

On the other hand, even at the very initial stage of the frontal collision of the vehicle 1, the front side member 3, the subframe 6, and the connecting member 2 can appropriately receive collision loads having different heights. Therefore, it is possible to appropriately avoid insufficient load bearing performance at the very early stage of the frontal collision of the vehicle 1 . As a result, it is possible to take a relatively long time from when the frontal collision of the vehicle 1 occurs and when the occupant restraint operation is started by the seat belt until the vehicle speed becomes zero. As a result, it is possible to prevent or suppress deterioration of the injury value due to compression of the passenger's chest or the like.

In FIG. 6(b), the connecting member 2 is bent in a substantially Z-shape. The amount of deformation is large, which is desirable. However, more preferably, when the compression deformation of the compression deformation permissive portion 30A of the front side member 3 over substantially the entire length region is completed by the collision load, the connection member 2 is in the state shown by the phantom lines in FIG. Configured.
7, the bent portions 21a and 21b of the connecting member 2 are substantially aligned in the vehicle front-rear direction, and the intermediate region 20c extends in the vehicle width direction. The connecting member 2 generates a thrust force against the collision load from the front side of the vehicle. It is possible to effectively generate a thrusting force against the collision load (the intermediate region 20c and the bent portion 21a of the connecting member 2 are located further to the rear of the vehicle than the positions indicated by the virtual lines in FIG. 7 (right side in the same figure). , it is difficult for an effective thrusting force against the collision load to occur during that period).

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.

The connection member for absorbing collision energy is not limited to the bent bar-shaped one having the two bent portions 21a and 21b of the above-described embodiment. For example, a straight bar shape, a curved bar shape, or the like may be used, and a shape other than the bar shape (plate shape, etc.) is also possible. Further, instead of or in addition to the configuration of forming a bent portion at a midpoint in the longitudinal direction of the connecting member, a rigid breaking point provided with a through hole, a weak portion, or the like is set so that when a collision load is input, the breaking point is set. can also be configured to cause bending deformation in the connecting member with the rigid breaking point as a starting point.

A pair of left and right front side members may be provided in the front portion of the vehicle, spaced apart in the vehicle width direction, and each extending in the front-rear direction of the vehicle. The compressive deformation permitting portion provided in the region near the front end of each front side member may be constructed so as to generate compressive deformation when a collision load greater than or equal to a predetermined amount is input when a frontal collision of the vehicle occurs. Its specific configuration is not limited.

The front fixing member is not limited to the radiator support, and may be, for example, a front bulkhead. However, the front fixing member is preferably a frame-like body. Here, the frame-like body means a pair of left and right columnar portions which are joined to the front portions of the pair of left and right front side members and stand upright, and a pair of columnar portions extending in the vehicle width direction so as to bridge the pair of columnar portions. A member with at least one extending member (cross member) is relevant.
Unlike the embodiments described above, the crash box may not be provided in the lower portion of the front fixing member.
The rear fixing member is not limited to the moment canceller of the above-described embodiment, and may be a member other than this.
The sub-frame is not limited to a V-shape when viewed from the side, and may be, for example, straight without a bent portion, or may have a bent shape different from the V-shape.

It goes without saying that the vehicle front structure of the present invention can be applied not only to engine vehicles but also to hybrid vehicles and electric vehicles.

A Vehicle front structure 1 Vehicle 2 Connection member 3 Front side member 30A Compression deformation allowance part 4 Suspension member 5 Radiator support (front side fixing member)
6 Subframe 85 Moment canceller (rear fixing member)

Claims (1)

In the front part of the vehicle, compression deformation that extends in the vehicle front-rear direction at intervals in the vehicle width direction, and in which a region near the front end undergoes compression deformation when a collision load exceeding a predetermined level is input when a frontal collision of the vehicle occurs. A pair of left and right front side members serving as an allowance,
a front side fixing member fixedly attached to regions near the front ends of the pair of front side members such that upper and lower portions protrude upward and downward, respectively, from the pair of front side members;
When the lower portion of the front side fixing member is fixed to the vehicle rear side of the lower portion of the front side fixing member in the region below the pair of front side members and the lower portion of the front side fixing member retreats due to a frontal collision of the vehicle. a subframe that causes deformation in the
a rear fixing member fixedly attached to the pair of front side members so as to be located on the rear side of the vehicle relative to the upper portion of the front fixing member in the region above the pair of front side members; ,
A vehicle front structure comprising:
At least a portion of the region above the pair of front side members is provided so as to overlap with the upper side of the sub-frame when viewed from the side of the vehicle, and the upper portion of the front side fixing member and the rear side fixing member are separated from each other. A vehicle front part characterized by further comprising a connection member for absorbing collision energy, which is bridge-connected and deforms when a vehicle front collision occurs and the upper part of the front side fixing member retreats. structure.

Images