JP2020121592A - Vehicle front part structure - Google Patents

Abstract

An object of the present invention is to provide a vehicle front structure that can improve safety performance in the event of a frontal collision of a vehicle compared to conventional structures. [Solution] Both end portions of a suspension member 4 in the vehicle width direction are connected and supported by a pair of front side members 3 provided with an inward inclined portion 33 via a front connecting portion 9A and a rear connecting portion 9B. , in the vehicle front structure A, in the vicinity of the inward side in the vehicle width direction of the rear connection part 9B of the suspension member 4, there is a predetermined inward connection in the rear connection part 9B of the suspension member 4 in the vehicle width direction. A fragile portion 48 is provided that can be deformed when the above load Fa is applied. [Selection diagram] Figure 7

Description

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

As an example of the vehicle front structure, there are those described in Patent Documents 1 and 2.
In the vehicle front structure described in Patent Documents 1 and 2, a pair of left and right front side members are provided as a skeletal member of the vehicle body front part, and a front suspension is provided below the pair of front side members. Suspension member is attached. This attachment is achieved by connecting both ends of the suspension member in the vehicle width direction to the pair of front side members via the front connecting portion and the rear connecting portion.

In such a structure, when a front collision of the vehicle occurs and a collision load is input to the front side member and the suspension member from the front of the vehicle, the collision energy is efficiently absorbed at various parts of the vehicle front part, or It is desirable to prevent the suspension member from retreating significantly and entering the vehicle compartment. For this reason, in the related art, when the suspension member retracts, an appropriate resistance force is generated in the rear connecting portion, or the connection state between the suspension member and the front side member in the rear connecting portion is released to suspend the suspension member. A method of dropping the member downward is often adopted. In Patent Document 1, a groove portion for retracting the fastening bolt of the rear connecting portion is formed, and when a collision load of a predetermined amount or more acts on the suspension member, the fastening bolt moves along the groove portion. Is configured.

However, the above-mentioned conventional technique has a problem to be solved as described below.

That is, in Patent Document 2, the rear side connecting portion between the front side member and the suspension member is located on the inner side in the vehicle width direction with respect to the front side connecting portion. The vicinity of the front connecting portion and the rear connecting portion is formed as a pair of inwardly-inclined portions that are inclined so that the mutual distance in the vehicle width direction becomes narrower toward the vehicle rear side. When a frontal collision occurs in a vehicle having such a structure and the collision load is input to the front side member, a bending moment is easily generated in this front side member, and the rear side connecting portion of the front side member is provided. There is a possibility that the provided portion may be deformed or displaced inward in the vehicle width direction. Such deformation or displacement increases as the inclination angle of the inwardly inclined portion increases.
When the above-mentioned deformation or displacement of the front side member occurs, a large load is generated in the vehicle-width direction on the rear side connecting portion between the front side member and the suspension member, and the rear side connecting portion is different from the original structure. There is a risk of becoming a state. Due to this, at the time of a frontal collision of the vehicle, the collision energy absorption operation and the connection release operation (retracting operation and dropping operation of the fastening bolt) that should originally occur due to the collision load from the front side of the vehicle are applied to the rear connecting portion. It may not be possible to generate it properly. From the viewpoint of enhancing the safety performance at the time of a frontal collision of the vehicle, it is desired to appropriately eliminate such a defect.

JP, 2004-130827, A JP, 2005-162144, A

The present invention has been devised under the circumstances as described above, and it is an object of the present invention to provide a vehicle front structure capable of improving safety performance at the time of a frontal collision of a vehicle as compared with the related art. I am trying.

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

The vehicle front structure provided by the present invention includes a pair of left and right front side members that extend in the vehicle front-rear direction at a lower portion of the vehicle front portion and are spaced apart from each other in the vehicle width direction. A suspension member whose both end portions in the vehicle width direction are connected and supported via a front connecting portion and a rear connecting portion, wherein the rear connecting portion is located more inward in the vehicle width direction than the front connecting portion. The peripheral portions of the front connecting portion and the rear connecting portion of the pair of front side members that are located are a pair of inward and outward inclined portions that are inclined such that the mutual distance in the vehicle width direction becomes narrower toward the vehicle rear side. In the vehicle front structure, in the vicinity of an inner side in the vehicle width direction of the rear connecting portion of the suspension member, the rear connecting portion of the suspension member extends inward in the vehicle width direction. It is characterized in that a fragile portion capable of causing deformation when a load larger than a predetermined value is applied is provided.

With such a configuration, the following effects can be obtained.
That is, when a frontal collision of the vehicle occurs and the collision load is input to the front side member, the front side member is provided with the inwardly inclined portion, so that the front side member is in the vehicle width direction. It may be deformed or displaced inward, and a load (force in the vehicle width direction) inward in the vehicle width direction may be applied to a portion where the rear connecting portion of the suspension member is provided inward. In this case, the fragile portion of the suspension member near the inner side in the vehicle width direction of the rear connecting portion is deformed (buckling deformation, etc.) by the force in the vehicle width direction, so that the load absorbs the load. It is possible to maintain the structure of the rear connecting portion itself between the suspension member and the front side member as originally intended. As a result, at the time of a frontal collision of the vehicle, the collision energy absorption operation of the rear coupling part (for example, the backward movement of the fastening bolt) or the decoupling operation of the rear coupling part caused by the collision load from the vehicle front side is appropriately performed. It is possible to improve the safety performance at the time of a frontal collision of the vehicle.

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

(A) is a principal part side view which shows an example of the vehicle front part structure which concerns on this invention, (b) is an enlarged principal part side sectional view of (a). FIG. 2 is a bottom view of a main part of FIG. 1. It is a principal part enlarged view of FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. It is a principal part cross-section perspective view of FIG. FIG. 2 is a schematic perspective view of a main part of a suspension member in the vehicle front structure shown in FIG. 1. FIG. 7 is a schematic plan view of a main part of FIG. 6. FIG. 3 is a side view of a partly broken main part showing the operation of the vehicle front structure shown in FIG. 1.

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

The vehicle front structure A shown in FIGS. 1 to 4 includes a suspension member 4 (sub) for suspending a front wheel 19 via a pair of left and right front side members 3 and a lower arm 7 provided at a lower portion of a front portion of a vehicle 1. (Also referred to as a frame), and a front connecting portion 9A for attaching the suspension member 4 to the pair of front side members 3 and rear connecting portions 9B and 9B'.
The suspension member 4 is provided with a fragile portion 48 which will be described later with reference to FIGS. 6 and 7.

The pair of front side members 3 are located on both sides in the vehicle width direction of the engine room 10 in which the power plant 2 including an engine, a transmission, and the like is arranged, and extend in the vehicle front-rear direction. have. As shown in FIG. 1, a pair of rearward descending inclined portions 30 and a substantially horizontal portion 31 are sequentially connected to the rear ends of the pair of front portions 32. However, in the bottom view shown in FIG. 2 (similarly in a plan view), a pair of inwardly-inclined portions 33 (range shown by reference symbol Sa in FIG. 2) and a rearward extension are provided on the rear end side of the pair of front portions 32. The installation portion 34 is configured to be sequentially connected. The pair of inwardly-inclined portions 33 are inclined in a bottom view so that the mutual distance in the vehicle width direction becomes narrower toward the vehicle rear side.

As shown in FIG. 4 and FIG. 5, each front side member 3 is configured by using a member having a hat-shaped cross section, for example, and at a place where the floor portion 11 of the vehicle 1 is provided, this floor portion is provided. It is welded to the lower surface of 11. The floor portion 11 is configured by joining the lower end portion of the dash panel 11a and the front end portion of the front floor panel 11b.

The suspension member 4 is a member that rotatably supports the base end portion of the lower arm 7, and is located below the rearwardly descending inclined portion 30 of the front side member 3 in a vehicle side view. Although details of the suspension member 4 will be described later, the suspension member 4 has a form extending in the vehicle width direction and is attached to the front side member 3 via the front side connecting portion 9A and the rear side connecting portions 9B and 9B'.

As shown in FIG. 1, in the front connecting portion 9A, an upper portion of a front bracket portion 41 standingly provided on an upper surface portion of a front-side region of the suspension member 4 is attached to the front side member 3 via a support member 39. It is a fixedly connected part. Inside the front side member 3, a reinforcement 39a for increasing the mounting strength of the support member 39 is appropriately provided.

The rear connecting portion 9B is a portion where the rear portion of the suspension member 4 is fastened with a bolt 90 to the lower wall portion 38a of the bracket portion 38 welded to the lower surface side of the rearwardly descending inclined portion 30. In the rear connecting portion 9B, when a front collision of the vehicle 1 occurs and a large load is applied from the front side of the vehicle, the bolt 90 is located below the bracket portion 38, as described later with reference to FIG. The wall portion 38a is retracted while being broken, and can be detached from the bracket portion 38 when the load is continued even after the wall portion 38a is retracted by a predetermined amount or more. On the other hand, the front connecting portion 9A has a higher connecting strength between the front side member 3 and the suspension member 4 than the rear connecting portion 9B, and is a portion that is difficult to be disconnected.
The rear connecting portion 9B′ is a portion where the stay 42 fixed to the rear portion of the suspension member 4 is fastened to the portion of the rearwardly descending inclined portion 30 below the bracket portion 38 using a bolt 91.

The lower arm 7 is rotatably connected to the suspension member 4 at its base end so that the front wheel 19 supported at the tip and the suspension member 4 can be vertically moved relative to each other. More specifically, the base end portion of the lower arm 7 is branched into a front portion and a rear portion, and is attached to the suspension member 4 via the front rotation support portion 8A and the rear rotation support portion 8B. The front rotation support portion 8A is configured by using a rubber bush 81 having a central axis extending in a substantially horizontal direction, and the rear rotation support portion 8B has a standing rubber bush having a central axis extending in a vertical height direction. It is configured by using 82. The rubber bush 82, stay 42, suspension member 4, and bracket portion 38 are fastened together using bolts 90.

As shown in FIG. 3, the center P2 of the rear rotation support portion 8B of the lower arm 7 is offset from the center P1 of the front rotation support portion 8A by an appropriate dimension L1 inward in the vehicle width direction, and It is located directly below the front side member 3. Therefore, while simplifying the configuration, it is possible to enhance the building rigidity of the rear rotation support portion 8B and its peripheral portion and further improve the maneuverability.
Corresponding to the above-described configuration, the rear connecting portions 9B and 9B' are offset from the front connecting portion 9A inward in the vehicle width direction by an appropriate dimension L2. The inwardly inclined portion 33 helps to realize such a configuration easily and accurately.

As shown in FIG. 6, the suspension member 4 has a hollow shape formed by joining the upper member 40b to the lower member 40a. As shown in the figure and FIG. 7, a bracket 66 supporting the stabilizer 65 is welded to the upper surface of the suspension member 4, and a reinforcing member 5 (bulk) for reinforcing the mounting position of the bracket 66 is provided. It is welded to the inside of the suspension member 4. As a result, the vicinity of the rear connecting portion 9B on the inner side in the vehicle width direction is a weak portion 48.

More specifically, in FIG. 6 and FIG. 7, the pair of upper and lower hole portions 47 provided in the suspension member 4 is a portion into which the bolt 90 shown in FIG. The peripheral portions of the pair of holes 47 correspond to the rear connecting portion 9B of the suspension member 4. On the other hand, the reinforcing member 5 is arranged so as to be spaced inward of the rear connecting portion 9B in the vehicle width direction, and the top plate portion 50, the seat plate portion 51, and the tip end portion of the protruding portion 52 of the reinforcing member 5 are arranged. 52a is welded to the upper wall portion, the lower wall portion, and the side wall portion of the suspension member 4, respectively, and the rigidity of the portion where the reinforcing member 5 is provided is increased. Therefore, the range from the rear connecting portion 9B to the attachment position of the reinforcing member 5, that is, the range indicated by reference symbol Sb in FIG. 7, is a fragile portion having low rigidity relative to the place reinforced by the reinforcing member 5. It is 48. As will be described later, when the vehicle 1 collides with the front, a force Fa inward in the vehicle width direction acts on the rear connecting portion 9B, but the fragile portion 48 buckles when the force Fa of a predetermined value or more is received. It is considered to be a site that causes compression deformation such as.
Preferably, the rear end of the main portion (upper plate portion 50) of the reinforcing member 5 is located on the vehicle front side with respect to the rear connecting portion 9B by an appropriate dimension La, or in the vehicle front-rear direction, the vehicle rear connecting portion 9B. It is provided at a position that coincides with (that is, La=0).

In this embodiment, the torque box 14 (outer torque box), the inner torque box 13a, and the cross member 6 are provided as means for increasing the rigidity in the vicinity of the rear connecting portions 9B, 9B′ of the front side member 3. ing. The torque box 14 is a member that bridges and connects the front end of the rocker 15 and the front side member 3. The inner torque box 13a is a portion in which the front portion of the inner torque member 13 for reinforcing the base portion of the floor tunnel portion 12 formed in the floor portion 11 is bent or curved outward in the vehicle width direction, and one end thereof is It is joined to the front side member 3. As well shown in FIGS. 4 and 5, the cross member 6 connects the upper member 3A joined to the upper side of the front side member 3 with the floor portion 11 interposed therebetween and the floor tunnel portion 12 in the vehicle width direction. It is a member that does.

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

When a frontal collision occurs in the vehicle 1 and a load is applied to the front portion of the vehicle 1, the front portion 32 of the front side member 3 is compressed and deformed, and the suspension member 4 is also deformed as the power plant 2 retracts. fall back. Therefore, as shown in FIG. 8, a load Fb (shearing force on the bolt 90) toward the vehicle rear side acts on the rear connecting portion 9B, and the bolt 90 breaks the lower wall portion 38a of the bracket portion 38. While moving backward, the load Fb absorbs energy. If the load Fb continues to act after the bolt 90 retracts by a predetermined amount, the amount of breakage of the lower wall portion 38a increases, and the bolt 90 falls off from the bracket portion 38. As a result, the suspension member 4 can be dropped from the front side member 3, and it is possible to prevent the suspension member 4 from retreating significantly and entering the vehicle interior. In the rear connecting portion 9B', the stay 42 is relatively easily and largely deformed by the collision load.

Since the front side member 3 has the inwardly-inclined portion 33, when a collision load is applied from the front side of the vehicle, a bending moment is likely to be generated, and the peripheral portion of the rear side connecting portions 9B and 9B′ is a vehicle. The vehicle body is deformed or displaced inward in the width direction, and a force Fa inward in the vehicle width direction due to the deformation or displacement acts on the rear connecting portion 9B of the suspension member 4. On the other hand, when the force Fa is larger than a predetermined value, the fragile portion 48 of the suspension member 4 is deformed such as buckling to absorb energy, and the rear side of the suspension member 4 and the front side member 3 is absorbed. The relative structure of the connecting portion 9B is maintained to be an originally intended structure, that is, an appropriate structure capable of appropriately applying a load as a shearing force to the bolt 90. Therefore, it is possible to prevent the operation of the rear connecting portion 9B described above with reference to FIG. 8 from being unduly disturbed by the force Fa. As a result, the safety performance at the time of a frontal collision of the vehicle 1 can be improved.

In the present embodiment, as described with reference to FIG. 7, the rear end portion of the reinforcing member 5 is located on the vehicle front side with respect to the rear connecting portion 9B, or is provided in the same arrangement in the vehicle front-rear direction. Therefore, at the time of a frontal collision of the vehicle 1, as shown in FIG. 8, the suspension member is located at a position on the vehicle front side of the rear connecting portion 9B or at a position corresponding to the rear connecting portion 9B in a vehicle side view. It is also possible to deform 4 by buckling. Such buckling deformation generates a shearing force on the bolt 90 and is effective in applying a twisting load to the bolt 90.

In the present embodiment, as described above, the torque box 14 (outer torque box), the inner torque box 13a, and the cross member 6 are provided, and the rear side connecting portions 9B and 9B' of the front side member 3 are provided. The rigidity of is increased. For this reason, the torsional rigidity of the vehicle body can be enhanced, and the support state of the suspension member 4 can be stabilized. In addition, when the vehicle 1 collides with the front side member 3, the front side member 3 is deformed inward in the vehicle width direction or It is also possible to suppress the displacement. Therefore, the operation in the rear connecting portion 9B described with reference to FIG. 8 can be caused more reliably.

The present invention is not limited to the contents of the above-mentioned embodiment. The specific configuration of each part of the vehicle front structure according to the present invention can be modified in various ways within the scope intended by the present invention.

In the above-described embodiment, the fragile portion 48 is provided by providing the reinforcing member 5 for reinforcing the attachment portion of the stabilizer 65 in a position separated from the rear connecting portion 9B, but the present invention is not limited to this. Not limited. As the reinforcing member, for example, a reinforcing member at a mounting position of another member such as a steering gear box may be used, or may be a dedicated reinforcing member for providing the weakened portion 48.
The fragile portion can also be configured by providing a through hole on the vehicle width direction inner side of the rear connecting portion of the suspension member.
From the viewpoint of improving the steerability of the vehicle 1, the center P2 of the rear rotation support portion 8B of the lower arm 7 of the front suspension is offset more inward in the vehicle width direction than the center P1 of the front rotation support portion 8A. However, it is also possible to adopt a different configuration.
As the rear connecting portion, for example, only the rear connecting portion 9B may be provided and the rear connecting portion 9B' may not be provided.
It goes without saying that the vehicle front structure of the present invention is applicable not only to engine vehicles but also to hybrid vehicles and electric vehicles.

A vehicle front structure 1 vehicle 11 floor 11a dash panel 11b front floor panel 12 floor tunnel 3 front side member 33 inward slope (of front side member)
4 Suspension member 48 Weak section

Claims (1)

A pair of left and right front side members that extend in the vehicle front-rear direction in a vehicle width direction at a lower portion of the vehicle front portion, and are arranged at a distance from each other
A suspension member in which both end portions in the vehicle width direction are connected and supported to the pair of front side members via a front connecting portion and a rear connecting portion,
Is equipped with
The rear connecting portion is located on the inner side in the vehicle width direction with respect to the front connecting portion, and the peripheral portions of the front connecting portion and the rear connecting portion of the pair of front side members are closer to the vehicle rear side. A vehicle front structure, which is a pair of inwardly-inclined portions that are inclined so that a mutual interval in the vehicle width direction is narrowed,
Among the suspension members, near the inner side in the vehicle width direction of the rear connecting portion, deformation is caused when a load inward in the vehicle width direction is applied to the rear connecting portion of the suspension member. Vehicle front structure, characterized in that it is provided with a weakened part that can be generated.

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