JP2023089643A - vehicle structure - Google Patents

Abstract

To provide a vehicle structure that can improve steering stability easily and properly in comparison with a conventional vehicle structure, and has an excellent function of buffering impact caused at the time of a front collision of a vehicle.SOLUTION: In a vehicle structure A, a suspension member 5 is constituted in a nearly rectangular shape in a planar view, and arm front-side connection parts J1 connecting front portions of base end parts of lower arms 4 to the suspension member 5 are provided at both end parts in a vehicle width direction of a front-side frame member 50 of the suspension member 5 or at front parts of lateral-side frame members 52. In the front-side frame member 50, a portion Sa close to a center in the vehicle width direction is formed in a curved shape or a bent shape in a planar view, which protrudes toward a front side of a vehicle beyond both end parts in the vehicle width direction and the arm front-side connection parts J1.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to the structure of a vehicle such as an automobile, and more particularly to a structure around a mounting location of a front suspension (front suspension) of the vehicle.

BACKGROUND ART As a front suspension structure of a vehicle, a structure in which a suspension member is attached to a pair of left and right front side members as vehicle body constituent members provided in the front part of the vehicle and a lower arm is connected to the suspension member is often adopted. The lower arm is a member that supports the front wheel at its tip (outer end in the vehicle width direction). The front and rear parts of the base end of the lower arm are suspended via an arm connecting part using a rubber bush or the like so that the front end of the lower arm swings in the vertical direction and the front wheel can move up and down. rotatably connected to the member;
Here, as the above-mentioned suspension member, there is means for using a substantially rectangular frame shape (parallel cross shape) in a plan view as described in Patent Documents 1 and 2, for example. If the suspension member has such a shape, it is possible to secure a certain degree of strength while reducing the weight of the entire suspension member.

However, the prior art still has room for improvement as described below.
That is, the suspension member receives a force corresponding to the lateral force of the front wheels from the lower arm while the vehicle is running. On the other hand, if the suspension member cannot adequately bear the force, resulting in insufficient strength, the support of the lower arm becomes unstable and the steering stability deteriorates. Therefore, it is desired to appropriately solve such a problem.
On the other hand, when a frontal collision of a vehicle occurs, it is desired to efficiently absorb the collision energy using a suspension member as a means for mitigating the impact. On the other hand, for example, in Patent Document 1, when a collision load is input, a part of the suspension member is bent and deformed to absorb the collision energy. However, when the vehicle is, for example, a cab-over vehicle, it is difficult to increase the crash stroke of the front portion of the vehicle, and it is difficult to sufficiently absorb the collision energy by the bending deformation of the suspension members.

JP-A-8-85473 JP-A-11-129772

The present invention was conceived under the circumstances as described above, and is capable of easily and appropriately improving steering stability compared with the prior art, while preventing a frontal collision of the vehicle. The challenge is to provide a vehicle structure that is also excellent in terms of the impact mitigation function.

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

In the vehicle structure provided by the present invention, a suspension member attached to a vehicle body structural member at the front of the vehicle and a front portion of a base end portion on the vehicle width direction inner side are connected to the suspension member via an arm front side connecting portion. a pair of left and right lower arms connected with each other, and having a front wheel attached to a front end portion on the outer side in the vehicle width direction, and the attachment point of the front wheel being positioned on the rear side of the vehicle relative to the arm front side connection portion. The suspension members include a front frame member and a rear frame member that are spaced apart in the vehicle front-rear direction and extend in the vehicle width direction, and a suspension member that is spaced in the vehicle width direction and extends in the vehicle front-rear direction, and the front frame member and the rear frame member. It has a substantially rectangular frame shape in a plan view and includes a pair of left and right lateral frame members that connect both ends of the rear frame member in the vehicle width direction. or a front portion of each of the lateral frame members, wherein the front portion of the front frame member is configured such that a portion near the center in the vehicle width direction of the front frame member overlaps both ends in the vehicle width direction and the arm It is characterized in that it has a curved shape or a bent shape in a plan view that protrudes toward the front side of the vehicle from the front connecting portion.

According to such a configuration, the following effects are obtained.
First, since the attachment point of the front wheel on the lower arm is located on the rear side of the vehicle with respect to the arm front side connecting portion that connects the front portion of the base end portion of the lower arm and the suspension member to the suspension member, when the vehicle is running, The lateral force of the front wheel acts on the suspension member as a pressing force directed inward and obliquely forward in the vehicle width direction from the lower arm to the suspension member via the arm front side connecting portion. On the other hand, the shape of the front frame member of the suspension member in plan view is curved or bent in the direction in which the pressing force acts or in a direction close thereto. Therefore, the pressing force is effectively received by the front frame member (it is possible to suppress the generation of a large bending moment in the front frame member due to the pressing force). As a result, it is possible to stably support the lower arm and improve the steering stability of the vehicle.
Secondly, when a frontal collision of the vehicle occurs and the collision load is input to the front portion of the suspension member, the front frame member, which had previously protruded toward the front of the vehicle, deforms into a non-protruding state. Thereby, a collision energy absorption function is obtained. Therefore, the collision energy can be absorbed and the shock absorbing function can be improved without greatly deforming the entire suspension member. This is the best effect for cab-over vehicles where it is difficult to secure a large crash stroke at the front of the vehicle.
Thirdly, the above effect is obtained by devising the shape of the front frame member of the suspension member. No need to use. Therefore, the productivity is good, and it helps to reduce the cost and weight of the vehicle.

In the present invention, it is preferable that the front frame member of the suspension member is mounted on the vehicle width direction outer side with respect to each of the lateral frame members when receiving a first load of a predetermined or more from the front side of the vehicle. In addition, a second load directed toward the obliquely rearward side of the vehicle can be input, and when the second load is input to each of the lateral frame members at a midway position in the vehicle front-rear direction of each of the lateral frame members, A rigid breaking point is provided as a starting point for bending deformation of each of the lateral frame members so as to displace the intermediate portion outward in the vehicle width direction.

According to this configuration, when a frontal collision of the vehicle occurs, not only is the front frame member of the suspension member deformed by the input of the first load, but also the second load from the front frame member to the lateral frame member is deformed. can be generated, and the lateral frame member can be actively bent and deformed starting from the rigid breaking point. Therefore, it is possible to increase the amount of collision energy absorption and improve the impact cushioning function, load bearing performance, and the like. The bending deformation of the lateral frame member is a deformation in which the intermediate portion of the lateral frame member is displaced outward in the vehicle width direction. Unfair interference can also be avoided appropriately.

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 bottom view of a main part showing an example of a vehicle structure according to the present invention; FIG. FIG. 2 is a schematic side view of a main part of the vehicle structure shown in FIG. 1; FIG. 3 is a schematic perspective view of a suspension member that constitutes the vehicle structure shown in FIGS. 1 and 2; FIG. FIG. 4 is a schematic plan view of the suspension member shown in FIG. 3; 4 is a schematic front view of the suspension member shown in FIG. 3; FIG. 4 is a schematic bottom view of the suspension member shown in FIG. 3; FIG. FIG. 2 is an operation explanatory view of the vehicle structure shown in FIG. 1;

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

A vehicle structure A shown in FIGS. 1 and 2 is applied to a cab-over type vehicle 1 . A front floor portion 2 of the vehicle 1 is provided with an opening 20 for a power plant (not shown) mounted under the floor, and a seat riser and a seat portion (not shown) are provided above the opening 20 .

The vehicle structure A includes a pair of left and right front side members 3 (indicated by dots in FIG. 1), a pair of left and right lower arms 4 that form a front suspension FS and suspend front wheels 9, and a suspension. It has members 5 (also called subframes).

The pair of front side members 3 correspond to an example of the vehicle structural member according to the present invention, and extend in the vehicle front-rear direction while being spaced apart in the vehicle width direction at the front portion of the vehicle. Each front side member 3 is in the shape of a square pipe made of, for example, a metal member having a hat-shaped cross section. Cross members 80a to 80d for reinforcement extending in the vehicle width direction are bridged and connected between the pair of front side members 3. As shown in FIG. A front bumper reinforcement 81 is bridgingly connected to the front ends of the pair of front side members 3 .

The lower arm 4 is a member that supports the front wheel 9 and that is rotatably supported by the suspension member 5 at its base end, which is the inner portion in the vehicle width direction (see also FIGS. 3 to 6, FIGS. 4 to 6). In the figure, the lower arm 4 is marked with light ink). More specifically, a mounting hole portion 48 for a joint member 49 (not shown in FIG. 3) such as a ball joint is provided at the front end portion of the lower arm 4, which is the outer portion in the vehicle width direction. A knuckle (not shown) for the front wheel 9 is attached to support the front wheel 9 . The mounting hole portion 48 corresponds to an example of the "mounting portion of the front wheel" in the present invention.

An arm front connecting portion J1 and an arm rear connecting portion J2 for connecting the lower arm 4 to the suspension member 5 are provided at the front and rear portions of the base end portion of the lower arm 4 . These two connecting portions J1 and J2 are constructed using, for example, rubber bushes 47a and 47b, and the tip portion side of the lower arm 4 is swung vertically about these two connecting portions J1 and J2. The base end portion of the lower arm 4 is rotatably connected to the suspension member 5 so as to enable this.

As shown in FIG. 6, the mounting hole 48 for the front wheel of the lower arm 4 is located on the rear side of the vehicle by an appropriate dimension La relative to the front connecting portion J1 of the arm. Therefore, the lateral force LF acting on the front wheel 9 acts as a pressing force LF' directed inward and obliquely forward in the vehicle width direction at the arm front side connecting portion J1.

The suspension member 5 has a substantially rectangular frame shape in plan view, and includes a front frame member 50 , a rear frame member 51 , and a pair of left and right lateral frame members 52 . The front frame member 50 and the rear frame member 51 are members that extend in the vehicle width direction while being spaced apart in the vehicle front-rear direction. and connects both end portions of the front frame member 50 and the rear frame member 51 in the vehicle width direction. These members are connected to each other by welding, for example. A steering gear box (not shown) is attached to the front frame member 50 .

The suspension member 5 is attached to the lower surfaces of the pair of front side members 3 in a fixed state. As this mounting means, for example, a means is adopted in which an upwardly projecting bracket portion 53 is provided on the upper surface of the front frame member 50, and a bolt fastening portion 54 having a bolt insertion hole is provided in the rear frame member 51. there is As shown in FIG. 2, the upper portion of the bracket portion 53 and the bolt fastening portion 54 are fastened to the lower surface portion of the front side member 3 using bolts 88a and 88b.

Arm front connecting portions J1 are provided at both ends of the front frame member 50 in the vehicle width direction. Therefore, the above-described pressing force LF′ acting on the arm front connecting portion J1 is input to the front frame member 50 . On the other hand, the front frame member 50 has a curved shape in a plan view in which a portion Sa (see FIG. 6) near the center in the vehicle width direction protrudes further toward the front side of the vehicle than both ends in the vehicle width direction (and the arm front side connecting portion J1). or curved. In this embodiment, inclined portions Sb inclined at an appropriate angle α1 with respect to the vehicle width direction are provided on both outer sides of the portion Sa near the center in the vehicle width direction. It substantially matches the tilt angle of LF'.
Reference numeral 18 in FIG. 2 denotes a dash panel that defines the front part of the passenger compartment. A portion Sa of the front frame member 50 near the center in the vehicle width direction protrudes forward of the vehicle beyond the lower end portion of the dash panel 18 .

As shown in FIG. 5, the base end of the lower arm 4 is positioned higher than the tip end in a normal state, and is set so as to be inclined at an appropriate angle α2 when viewed from the front. there is On the other hand, at least the lower surface portion 50a of the front side frame member 50 near both ends in the vehicle width direction is inclined at an angle substantially matching the angle α2 in a front view.

The arm rear joint J2 of the lower arm 4 is provided at the rear end of the lateral frame member 52, and the rear frame member 51 is mounted on the lateral frame so as to avoid interference with the arm rear joint J2. It is located on the upper surface of the rear end of member 52 .

A rigid breaking point R is set at a midpoint of the lateral frame member 52 in the longitudinal direction of the vehicle. The rigidity breaking point R is a portion where the rigidity (bending strength) of the lateral frame member 52 changes suddenly, and serves as a starting point for causing bending deformation in the lateral frame member 52 when a load is input, which will be described later with reference to FIG. Become. In this embodiment, a substantially rectangular plate-shaped reinforcing member 6 made of metal is joined to the inner side of the front region of the lateral frame member 52. A boundary position between a portion where is provided and a portion where is not provided is defined as a rigid breaking point R. At the position of the rigid breakpoint R, the width dimension Lb of the lateral frame member 52 abruptly changes, and such a sudden change in the dimension also helps to set the rigid breakpoint R. It should be noted that, unlike the present embodiment, it is also possible to set the rigid breaking point R only by the abrupt change in the width dimension Lb without using the reinforcing member 6 .

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

First, when the vehicle 1 is running, as described above, the pressing force LF' caused by the lateral force LF of the front wheels 9 is applied to both ends of the front frame member 50 of the suspension member 5 via the arm front connecting portion J1. acts on The direction in which this pressing force LF' acts is inward and obliquely forward in the vehicle width direction, and the front frame member 50 is curved or bent so as to substantially match the direction in which the pressing force LF' acts. . Therefore, it is possible for the front frame member 50 to effectively receive the pressing force LF' while preventing a large bending moment or the like due to the pressing force LF' from being generated in the front frame member 50. FIG. As a result, the lower arm 4 can be stably supported, and the steering stability of the vehicle 1 can be improved.

Further, as described with reference to FIG. 5, at least the lower surface portion 50a of the front side frame member 50 near both ends in the vehicle width direction has an angle that substantially matches the inclination angle α2 of the lower arm 4 when viewed from the front. Inclined. Therefore, it is possible for the front frame member 50 to more effectively receive the pressing force LF′ acting on the front frame member 50 from the lower arm 4 .

On the other hand, when a frontal collision of the vehicle 1 occurs, as shown in FIG. 7, the front frame member 50 of the suspension member 5 may receive a first load F1 greater than or equal to a predetermined amount from the front side of the vehicle. be. On the other hand, since the front frame member 50 originally protrudes toward the front side of the vehicle, when the first load F1 is applied, the front frame member 50 is deformed into a non-protruding state. This deformation makes it possible to obtain a collision energy absorption function. According to such deformation of the front frame member 50, the entire suspension member 5 is not greatly deformed unnecessarily, and it is possible to preferably obtain a shock absorbing function. This is the optimum effect for cab-over vehicles where it is difficult to secure a large crash stroke at the front of the vehicle.

At the time of a frontal collision of the vehicle 1, when the first load F1 is input to the front frame member 50, a force is applied from the front frame member 50 to the front end portion of the lateral frame member 52 outwardly and obliquely rearward in the vehicle width direction. 2nd load F2 which goes will act. The second load F2 increases as the first load F1 increases, and when the value is greater than or equal to a predetermined value, the lateral frame member 52 undergoes bending deformation with the rigidity breaking point R as a starting point. This bending deformation is a bending deformation in a direction in which the position of the rigidity breaking point R is displaced outward in the vehicle width direction. When such bending deformation occurs, the amount of impact energy absorbed increases, making it possible to further improve impact relaxation performance and impact resistance performance.

Note that, as shown in FIG. 2, the lateral frame member 52 of the suspension member 5 is inclined forward downward. Therefore, when the second load F2 acts on the lateral frame member 52 at the time of a frontal collision of the vehicle 1, the position of the rigidity breaking point R not only displaces outward in the vehicle width direction but also descends. Bending deformation may be controlled as follows.

In the vehicle structure A of this embodiment, although the front frame member 50 and the lateral frame member 52 of the suspension member 5 are devised, neither special and expensive members nor large additional members are used, and the entire structure is configuration can be simplified. Therefore, the productivity is good, and it is preferable for promoting the reduction of the manufacturing cost and the weight reduction of the vehicle.

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

In the above-described embodiment, the arm front connecting portions J1 for connecting the front portion of the base end portion of the lower arm 4 to the suspension member 5 are provided at both ends of the front frame member 50 in the vehicle width direction. , and may be provided at the front portion of the lateral frame member 52 .
A pressing force directed inward in the vehicle width direction from the arm rear connecting portion J2 of the lower arm 4 to the rear frame member 51 of the suspension member 5 does not act so large. However, like the front frame member 50, the rear frame member 51 can also have a curved or bent shape corresponding to the pressing force.
As a means for setting the rigidity breaking point in the lateral frame member of the suspension member, in addition to or instead of the above-described means for partially providing the reinforcing member and the means for changing the width dimension of the lateral frame member, thin It is also possible to use means such as making a portion of the lateral frame member a partially weakened portion by providing a spot or a hole.
The vehicle body constituent members referred to in the present invention are not limited to the pair of left and right front side members. The suspension member may be attached to a vehicle body component other than the front side member.
The vehicle structure of the present invention is suitable for a cab-over vehicle, but the specific type and model of the vehicle are not limited. It goes without saying that the present invention can also be applied to hybrid vehicles, electric vehicles, and the like.

A Vehicle structure R Rigidity breaking point J1 Arm front side connecting portion 1 Vehicle 3 Front side member (body component)
4 Lower arm 48 mounting hole (front wheel mounting location)
5 Suspension member 50 Front frame member 51 Rear frame member 52 Lateral frame member 9 Front wheel

Claims (2)

a suspension member attached to a vehicle body component at the front of the vehicle;
A front portion of the base end portion on the vehicle width direction inner side is connected to the suspension member via an arm front side connecting portion, and a front wheel is attached to a tip portion on the vehicle width direction outer side. a pair of left and right lower arms whose mounting locations are located on the vehicle rear side of the arm front side connecting portion;
and
The suspension members include a front frame member and a rear frame member that extend in the vehicle width direction while being spaced apart in the vehicle front-rear direction, and a suspension member that extends in the vehicle front-rear direction while being spaced apart in the vehicle width direction. It has a substantially rectangular frame shape in a plan view and includes a pair of left and right lateral side frame members that connect both ends of the side frame members in the vehicle width direction,
In the vehicle structure, the arm front connecting portions are provided at both ends of the front frame member in the vehicle width direction or at front portions of the lateral frame members,
The front frame member has a curved or bent shape in a plan view such that a portion near the center in the vehicle width direction of the front frame member protrudes further toward the front side of the vehicle than both ends in the vehicle width direction and the front connecting portion of the arm. A vehicle structure characterized by: A vehicle structure according to claim 1,
The front frame member of the suspension member moves outward in the vehicle width direction and obliquely rearward of the vehicle with respect to each of the lateral frame members when receiving a first load of a predetermined amount or more from the front side of the vehicle. a second load is inputtable;
Each of the lateral frame members is provided at a midway position in the vehicle front-rear direction so as to displace the midway position outward in the vehicle width direction when the second load is applied to the lateral frame member. A vehicle structure provided with a rigid breaking point that serves as a starting point for bending deformation of a lateral frame member.

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