JP6893385B2 - Vehicle front structure - Google Patents

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 skeleton member of the front part of the vehicle body, and a front suspension is provided below the pair of front side members. Suspension member is installed. This mounting is achieved by connecting both ends of the suspension member in the vehicle width direction to a pair of front side members via a front connecting portion and a rear connecting portion.

In such a structure, when a frontal 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 can be efficiently absorbed at various places in the front part of the vehicle, or the collision energy can be efficiently absorbed. It is desirable that the suspension member does not retreat significantly and enter the passenger compartment. For this reason, conventionally, when the suspension member retracts, an appropriate resistance force is generated at the rear connecting portion, or the connection state between the suspension member and the front side member at the rear connecting portion is released to suspend the suspension. Means such as dropping members downward are 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 value or more is applied to the suspension member, the fastening bolt moves along the groove portion. It is configured as follows.

However, in the above-mentioned prior art, there is a problem to be solved as described below.

That is, in Patent Document 2, the rear connecting portion between the front side member and the suspension member is located inward in the vehicle width direction with respect to the front connecting portion, and correspondingly, the pair of front side members The front connecting portion and the vicinity portion of the rear connecting portion are a pair of inward inclined portions that are inclined so that the mutual distance in the vehicle width direction becomes narrower toward the rear side of the vehicle. When a front collision occurs in a vehicle having such a configuration and the collision load is input to the front side member, a bending moment is likely to be generated in the front side member, and a rear connecting portion of the front side members is provided. There is a risk that the location will 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 on the rear connecting portion between the front side member and the suspension member in the vehicle width direction, and the rear connecting portion differs 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 disconnection operation (retraction operation and disconnection operation of the fastening bolt, etc.) that should originally occur due to the collision load from the front side of the vehicle are applied to the rear connection portion. It may not be possible to cause it properly. From the viewpoint of enhancing the safety performance when the vehicle hits the front, it is desired to appropriately eliminate such a problem.

Japanese Unexamined Patent Publication No. 2004-130827 Japanese Unexamined Patent Publication No. 2005-162144

The present invention has been conceived under the above-mentioned circumstances, and an object of the present invention is to provide a vehicle front structure capable of improving safety performance at the time of a front collision of a vehicle as compared with the conventional case. It is supposed to be.

In order to solve the above problems, the following technical measures are taken in the present invention.

The vehicle front structure provided by the present invention includes a pair of left and right front side members extending in the vehicle front-rear direction in an arrangement spaced apart from each other in the vehicle width direction and a pair of front side members in the lower portion of the vehicle front. Suspension members whose both ends in the vehicle width direction are connected and supported via a front connecting portion and a rear connecting portion are provided, and the rear connecting portion is located inward in the vehicle width direction with respect to the front connecting portion. The front side connecting portion and the peripheral portion of the rear side connecting portion of the pair of front side members are a pair of inwardly inclined portions that are positioned and inclined so that the mutual spacing in the vehicle width direction becomes narrower toward the rear side of the vehicle. In the front structure of the vehicle, in the vicinity of the rear connecting portion inward in the vehicle width direction of the suspension member, the rear connecting portion of the suspension member is inward in the vehicle width direction. A fragile portion capable of causing deformation when a load exceeding a predetermined value is applied is provided, and the suspension member is a hollow shape formed by joining a lower member and an upper member. A reinforcing member for reinforcing a stabilizer mounting location set on the suspension member or a mounting location of another member different from the stabilizer is welded inside the suspension member, and the reinforcing member is connected to the rear side. The suspension member is provided so as to be separated from the portion in the vehicle width direction, and the region between the reinforcing member and the rear side connecting portion is the fragile portion . ..

According to such a configuration, the following effects can be obtained.
That is, when a front collision of the vehicle occurs and the collision load is input to the front side member, the front side member is provided with an inwardly inclined portion in the front side member, so that the front side member is in the vehicle width direction. A load (force in the vehicle width direction) equal to or greater than a predetermined value inward in the vehicle width direction may act on a portion that is deformed or displaced inward and is provided with a rear connecting portion of the suspension member. In this case, of the suspension members, the fragile portion of the rear connecting portion near the inner side in the vehicle width direction is deformed (buckling deformation, etc.) by the force in the vehicle width direction, and the load is absorbed by this deformation. As a result, the structure of the rear connecting portion itself between the suspension member and the front side member can be maintained in the originally intended structure. As a result, at the time of a front collision of the vehicle, the collision energy absorbing operation of the rear connecting portion (for example, the retreating operation of the fastening bolt) or the disconnecting operation of the rear connecting portion caused by the collision load from the front side of the vehicle is appropriate. 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 embodiments of the invention with reference to the accompanying drawings.

(A) is a side view of a main part showing an example of a vehicle front structure according to the present invention, and (b) is an enlarged side sectional view of a main part of (a). It is the bottom view of the main part of FIG. It is an enlarged view of the main part of FIG. FIG. 2 is a sectional view taken along line IV-IV of FIG. It is sectional drawing of the main part of FIG. It is a schematic perspective view of the main part of the suspension member in the vehicle front structure shown in FIG. FIG. 6 is a schematic plan view of a main part of FIG. It is a side view of the partial fracture main part which shows the operation of the vehicle front structure shown in FIG.

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 is a suspension member 4 (sub) for suspending the front wheels 19 via a pair of left and right front side members 3 and lower arms 7 provided in the lower part of the front portion of the vehicle 1. It also includes 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 a pair of front portions 32 that are located on both sides of the engine room 10 in which the power plant 2 composed of an engine, a transmission, and the like is arranged in the vehicle width direction and extend in the vehicle front-rear direction. have. As shown in FIG. 1, a pair of rear-down inclined portions 30 and a substantially horizontal portion 31 are sequentially connected to the rear end side of the pair of front portions 32. However, in the bottom view shown in FIG. 2 (the same applies to the plan view), a pair of inward inclined portions 33 (range indicated by reference numeral Sa in FIG. 2) and a rear side extension are placed on the rear end side of the pair of front portions 32. The structure is such that the installation units 34 are sequentially connected. The pair of inwardly inclined portions 33 are inclined in the bottom view so that the mutual distance in the vehicle width direction becomes narrower toward the rear side of the vehicle.

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

The suspension member 4 is a member that rotatably supports the base end portion of the lower arm 7, and is located below the rear-down inclined portion 30 of the front side member 3 in a vehicle side view. The details of the suspension member 4 will be described later, but it 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 side connecting portion 9A, the upper portion of the front side bracket portion 41 provided upright on the upper surface portion of the front side region of the suspension member 4 is attached to the front side member 3 via the support member 39. It is a fixedly connected part. Reinforce 39a for increasing the mounting strength of the support member 39 is appropriately provided in the front side member 3.

The rear connecting portion 9B is a portion where the rear portion of the suspension member 4 is fastened to the lower wall portion 38a of the bracket portion 38 welded to the lower surface side of the rear lowering inclined portion 30 by using bolts 90. In the rear connecting portion 9B, when a front collision of the vehicle 1 occurs and a large load is received from the front side of the vehicle, the bolt 90 is placed under the bracket portion 38 as described later with reference to FIG. If the wall portion 38a is retracted while being broken and the load is continuously received even after the wall portion 38a is retracted more than a predetermined value, the wall portion 38a can be detached from the bracket portion 38. On the other hand, the front side connecting portion 9A has a higher connecting strength between the front side member 3 and the suspension member 4 as compared with the rear side connecting portion 9B, and is considered to be a portion where the connection is difficult to be released.
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 a portion below the bracket portion 38 of the rear lowering inclined portion 30 by using a bolt 91.

The base end of the lower arm 7 is rotatably connected to the suspension member 4 so that the front wheel 19 supported by the tip and the suspension member 4 can move up and down 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 in a posture in which the central axis extends in a substantially horizontal direction, and the rear rotation support portion 8B is a rubber bush in an upright posture in which the central axis extends in the vertical height direction. It is configured using 82. The rubber bush 82, the stay 42, the suspension member 4, and the bracket portion 38 are jointly fastened using bolts 90.

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

As shown in FIG. 6, the suspension member 4 has a hollow shape formed by joining the upper member 40b onto the lower member 40a. As shown in FIGS. 7 and 7, a bracket 66 for 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 portion 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 defined as the fragile portion 48.

More specifically, in FIGS. 6 and 7, the pair of upper and lower holes 47 provided in the suspension member 4 are portions through which the bolts 90 shown in FIG. 1 and the like are inserted, and the upper and lower parts of the suspension member 4 are inserted. The peripheral edge of the pair of holes 47 corresponds 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 separated from the rear connecting portion 9B inward in the vehicle width direction, and the upper plate portion 50, the seat plate portion 51, and the tip portion of the protruding portion 52 of the reinforcing member 5 are arranged. The 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 mounting portion of the reinforcing member 5, that is, the range indicated by the reference numeral Sb in FIG. 7, is a fragile portion having low rigidity relative to the portion reinforced by the reinforcing member 5. It is 48. As will be described later, at the time of the front collision of the vehicle 1, a force Fa inward in the vehicle width direction acts on the rear connecting portion 9B, but the fragile portion 48 buckles when it receives a force Fa equal to or more than a predetermined value. It is said to be a part 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 of the rear side connecting portion 9B by an appropriate dimension La, or the vehicle rear connecting portion 9B in the vehicle front-rear direction. It is provided at the position corresponding to (that is, La = 0).

In the present embodiment, a torque box 14 (outer torque box), an inner torque box 13a, and a cross member 6 are provided as means for increasing the rigidity in the vicinity of the rear connecting portions 9B and 9B'of the front side member 3. ing. The torque box 14 is a member that bridges and connects the front end portion of the rocker 15 and the front side member 3. The inner torque box 13a is a portion where the front portion of the inner torque member 13 for reinforcing the base portion of the floor tunnel portion 12 formed on 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 is clearly shown in FIGS. 4 and 5, the cross member 6 bridges and 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 to be used.

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

When a front collision occurs in the vehicle 1 and a load is input to the front portion of the vehicle 1, the front portion 32 of the front side member 3 and the like are compressed and deformed, and the suspension member 4 also changes due to the retreat of the power plant 2. fall back. Therefore, as shown in FIG. 8, a load Fb (shearing force on the bolt 90) acts on the rear connecting portion 9B to the rear side of the vehicle, and the bolt 90 breaks the lower wall portion 38a of the bracket portion 38. The energy of the load Fb is absorbed at that time. If the load Fb continues to act after the bolt 90 is retracted by a predetermined amount, the amount of breakage of the lower wall portion 38a becomes large, 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 greatly deformed by the collision load.

Since the front side member 3 has an inwardly inclined portion 33, a bending moment is likely to be generated when a collision load is received from the front side of the vehicle, and the peripheral portions of the rear side connecting portions 9B and 9B'are the vehicles. It 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 a large force equal to or 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 The relative structure of the connecting portion 9B is maintained at 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 hindered by the force Fa. As a result, the safety performance of the vehicle 1 at the time of a front collision 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 front side of the vehicle with respect to the rear side connecting portion 9B, or is provided in the same arrangement in the vehicle front-rear direction. Therefore, at the time of the front collision of the vehicle 1, as shown in FIG. 8, the suspension member is located at a position on the front side of the vehicle from the rear connecting portion 9B or at a position coincident with the rear connecting portion 9B in the side view of the vehicle. It is also possible to buckle and deform 4. Such buckling deformation causes a shearing force to be generated in the bolt 90, which 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 vicinity of the rear connecting portions 9B and 9B'of the front side member 3 is provided. The rigidity of is increased. Therefore, the torsional rigidity of the vehicle body is increased, the support state of the suspension member 4 can be stabilized, and the front side member 3 is deformed inward in the vehicle width direction when the vehicle 1 collides with the front. 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 more reliably generated.

The present invention is not limited to the contents of the above-described embodiments. The specific configuration of each part of the vehicle front structure according to the present invention can be variously redesigned 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 mounting portion of the stabilizer 65 at a position separated from the rear connecting portion 9B. Not limited. As the reinforcing member, for example, a reinforcing member at a mounting location of another member such as a steering gear box may be used .
From the viewpoint of improving the maneuverability 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 inward in the vehicle width direction from the center P1 of the front rotation support portion 8A. Although it is preferable, a configuration different from this is also possible.
The rear connecting portion may be configured to include, for example, only the rear connecting portion 9B and not the rear connecting portion 9B'.
Of course, the vehicle front structure of the present invention can be applied not only to an engine vehicle but also to a hybrid vehicle and an electric vehicle.

A Vehicle front structure 1 Vehicle 11 Floor part 11a Dash panel 11b Front floor panel 12 Floor tunnel part 3 Front side member 33 Inward inclined part (of front side member)
4 Suspension member 48 Vulnerable part

Claims (1)

At the bottom of the front part of the vehicle, a pair of left and right front side members extending in the front-rear direction of the vehicle in an arrangement spaced apart from each other in the vehicle width direction.
A suspension member in which both ends in the vehicle width direction are connected and supported to these pair of front side members via a front connecting portion and a rear connecting portion.
Is equipped with
The rear connecting portion is located inward 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 rear side of the vehicle. It is a vehicle front structure that is a pair of inwardly inclined portions that are inclined so that the mutual spacing in the vehicle width direction becomes narrow.
Of the suspension members, the vicinity of the rear connecting portion on the inward side in the vehicle width direction is deformed when a predetermined or greater load is applied to the rear connecting portion of the suspension member in the vehicle width direction. There are vulnerable parts that can be created ,
The suspension member has a hollow shape formed by joining a lower member and an upper member, and inside the suspension member, a stabilizer mounting location set on the suspension member or another member different from the stabilizer is used. Reinforcing members for reinforcing the mounting location are welded,
The reinforcing member is provided so as to be separated from the rear connecting portion inward in the vehicle width direction, and among the suspension members, a region between the reinforcing member and the rear side connecting portion is formed as described above. The front structure of the vehicle, which is characterized by being a fragile part.

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