JP7107827B2 - vehicle front structure - Google Patents

Description

The present invention relates to a vehicle front structure.

In Patent Document 1, in order to suppress the bending of the bumper reinforcement (hereinafter referred to as bumper RF) at the time of so-called center pole collision and small lap collision, a vehicle width direction central portion and vehicle width direction both end portions of the bumper RF are suppressed. discloses a structure in which a center bulk and a side bulk are arranged respectively. Here, a center pole collision is a frontal collision with a columnar object near the center of the vehicle in the vehicle width direction, and a small lap collision is a collision in which the vehicle width direction edge slightly overlaps the colliding object. This is the case of a frontal collision in a state.

JP 2015-147437 A

By the way, in the above technique, it is conceivable that the bumper RF is bent at a position between the center bulk and the right side bulk or between the center bulk and the left side bulk at the time of collision with the center pole. Here, the above technique does not control the order of which of the left and right positions should be folded first.

However, the structure of the power unit behind the bumper RF and the dash part further behind is not symmetrical, and depending on the structure, it may be possible to reduce the amount of deformation of the passenger compartment by controlling the bending position and bending order of the bumper RF. There is Therefore, the above technique has room for improvement in this respect.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle front structure that reduces the amount of deformation of a passenger compartment by controlling the folding position and folding order of a bumper RF upon collision with a center pole.

A vehicle front structure according to claim 1, comprising a pair of front side members, a bumper reinforcement, a power unit, a dash section, and a support section, wherein the bumper reinforcement comprises the pair of front side members. The power unit is disposed between the pair of front side members and between the bumper reinforcement and the vehicle compartment, and the power unit extends in the first direction in the vehicle width direction. A first device and a second device are provided on the second side in the vehicle width direction, the first device and the second device are connected, and the dash portion is arranged between the power unit and the vehicle. The support portion is arranged between the dash portion and the first device so as to overlap with the first device when viewed from the front side of the vehicle, and the bumper reinforcement is positioned between the first device and the first device. A low-strength portion, a second low-strength portion, and a center portion in the vehicle width direction, wherein the first low-strength portion and the second low-strength portion are arranged on both sides of the center portion in the vehicle width direction, The first low-strength portion overlaps the first device when viewed from the front side of the vehicle, the second low-strength portion overlaps the second device when viewed from the front side of the vehicle, and the first low-strength portion is smaller than the dimension of the second low-strength portion in the longitudinal direction of the vehicle, and the dimension of the second low-strength portion in the longitudinal direction of the vehicle is greater than the dimension of the central portion in the longitudinal direction of the vehicle. small.

In the vehicle front structure according to claim 1, the bumper RF is joined to the vehicle front side end portions of the pair of front side members. A power unit is arranged between the bumper RF and the vehicle compartment between the pair of front side members. This power unit is configured by connecting a first device arranged on the first direction side in the vehicle width direction and a second device arranged on the second direction side in the vehicle width direction to each other. A dash portion is arranged between the power unit and the passenger compartment, and a support portion is arranged between the dash portion and the first device of the power unit. The support portion is arranged so as to overlap the first device of the power unit when viewed from the front side of the vehicle. Therefore, if the first device moves rearward of the vehicle, the first device is supported by the support portion.

The bumper RF is provided with a central portion in the vehicle width direction, and first low-strength portions and second low-strength portions arranged on both sides of the central portion in the vehicle width direction. The first low-strength portion is arranged to overlap the first device of the power unit when viewed from the front of the vehicle, and the second low-strength portion is arranged to overlap the second device of the power unit when viewed from the front of the vehicle. It is Further, the dimension of the first low-strength portion in the longitudinal direction of the vehicle is smaller than the dimension of the second low-strength portion in the longitudinal direction of the vehicle, and the dimension of the second low-strength portion in the longitudinal direction of the vehicle is equal to the dimension of the central portion in the longitudinal direction of the vehicle. It is set smaller than the size.

Here, if the second low-strength portion facing the second device breaks first when the center pole collides, the device to which the second low-strength portion transmits the collision load is the first device facing the support portion. not the second device. As a result, the shear input at the connecting portion between the first device and the second device is greater than in the case where the collision load is transmitted to the first device. Then, the connection between the first device and the second device is released (in other words, the power unit cracks), and only the second device, which receives the collision load from the second low-strength portion, moves toward the passenger compartment. A load may be locally transmitted to the dash portion, increasing the amount of deformation of the dash portion.

Therefore, in the vehicle front structure of the present invention, the bumper RF is provided with the first low-strength portion and the second low-strength portion having smaller dimensions in the vehicle front-rear direction than the central portion. The dimension is set larger than the dimension of the first low-strength portion in the longitudinal direction of the vehicle. Therefore, the bending strength of the bumper RF against bending in the longitudinal direction of the vehicle decreases in the order of the central portion, the second low-strength portion, and the first low-strength portion. As a result, when the center pole collides, the first low-strength portion is broken first, and then the second low-strength portion is broken. In addition, since the first low-strength portion is arranged so as to overlap the first device when viewed from the front side of the vehicle, the first device, which receives the collision load from the first low-strength portion that breaks first in the event of a center pole collision, It is supported by the support portion when it moves to the rear of the vehicle.

In other words, the device supported by the support portion when the vehicle moves rearward and the device for transmitting the collision load to the first low-strength portion that breaks first are the same device. The shear input generated at the connecting part of the is not increased. As a result, power unit cracking is suppressed.

Furthermore, by suppressing power unit cracking, the reaction force from the power unit to the bumper RF in the first low-strength portion increases. Therefore, the second low-strength portion of the bumper RF is likely to break. When the second low-strength portion is broken, the power unit is pushed rearward in the range (central portion) between the first low-strength portion and the second low-strength portion of the bumper RF, and the collision load is transferred in the vehicle width direction. can be distributed in As a result, it is possible to suppress local input to the dash portion, thereby suppressing deformation of the passenger compartment.

As described above, according to the present invention, it is possible to reduce the amount of deformation of the passenger compartment by controlling the folding position and folding order of the bumper RF at the time of collision with the center pole.

1 is a schematic plan view showing a vehicle front structure of this embodiment; FIG. 2 is a schematic plan view showing a moment when a center pole collision occurs in the vehicle front structure shown in FIG. 1 and the bumper RF is broken at the first low-strength portion; FIG. FIG. 3 is a schematic plan view showing a moment when a bumper RF is broken at a second low-strength portion in the vehicle front structure shown in FIGS. 1 and 2; FIG. 4 is a schematic plan view showing how a bumper RF presses a power unit in the vehicle front structure shown in FIGS. 1 to 3; (A) is a schematic plan view showing a bumper RF. (B) is a schematic diagram showing bending strength characteristics of the bumper RF shown in (A). (A) is a sectional view taken along line 6(A)-6(A) of FIG. 5(A). (B) is a sectional view taken along line 6(B)-6(B) in FIG. 5(A). (C) is a sectional view taken along line 6(C)-6(C) of FIG. 5(A). (A) is a schematic diagram showing bending resistance characteristics of a bumper RF in a vehicle front structure according to a comparative example. (B) is a schematic plan view showing a vehicle front structure according to a comparative example.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. FIG.

An arrow FR, an arrow UP, and an arrow LH shown in each figure indicate the front direction, the upward direction, and the left side of the vehicle, respectively. Further, in the following description, when front-rear, left-right, and up-down directions are used unless otherwise specified, front-rear in the vehicle front-rear direction, left and right in the vehicle width direction, and up and down in the vehicle vertical direction.

As shown in FIG. 1, the vehicle front structure of this embodiment includes a pair of left and right front side members 10 arranged on both sides of the vehicle front. The front side member 10 is a vehicle body frame member whose longitudinal direction is oriented in the vehicle front-rear direction, and is provided symmetrically with respect to the center line in the vehicle width direction of the vehicle.

The front side member 10 includes a deformation portion 12 arranged on the vehicle front side, and a body portion 14 arranged on the vehicle rear side of the deformation portion 12 and extending in the vehicle front-rear direction. The deformable portion 12 has lower compressive strength against a load in the longitudinal direction of the vehicle than the main body portion 14 . Examples of the deformable portion 12 include crash boxes made of aluminum or fiber-reinforced plastic.

In addition, the vehicle front structure includes a bumper RF 20 made of metal (made of steel in this embodiment). The bumper RF 20 is a vehicle body frame member extending along the vehicle width direction, and connects the vehicle front side end portions of the pair of left and right front side members 10 . Specifically, the rear surface of the bumper RF 20 is joined to the vehicle front side end portions of the deformation portions 12 of the pair of left and right front side members 10 . Although the bumper RF 20 that extends uniformly and linearly in the vehicle width direction is schematically illustrated, the bumper RF 20 has a shape in which both sides in the vehicle width direction are obliquely bent toward the rear side of the vehicle, that is, as a whole It may have an arcuate shape that protrudes toward the front side of the vehicle. A more detailed configuration of the bumper RF 20 will be described later.

The vehicle front structure also includes a power unit 30 arranged between the pair of left and right front side members 10 and behind the bumper RF 20 in the vehicle (between the bumper RF 20 and the passenger compartment (not shown)). The power unit 30 includes a transaxle 30L as a "first device" and an engine 30R as a "second device". Specifically, the transaxle 30L is arranged on the left side in the vehicle width direction (first direction side), and the engine 30R is arranged on the right side in the vehicle width direction (second direction side). A connecting portion 34 connects the vehicle width direction inner side (vehicle width direction right side) of the transaxle 30L and the vehicle width direction inner side (vehicle width direction left side) of the engine 30R. The power unit 30 is supported by the body portions 14 of the pair of left and right front side members 10 via left and right engine mounts 32 . Although not shown, the power unit 30 is also supported from below the vehicle at the transaxle 30L. Further, the width dimension of the engine 30R is larger than the width dimension of the transaxle 30L, and the connecting portion 34 is shifted to the left with respect to the center in the vehicle width direction.

The vehicle front structure also includes a dash portion 40 . Dash portion 40 is arranged between power unit 30 and a vehicle compartment (not shown), and is a portion that separates a space (engine compartment) in which power unit 30 is arranged from the vehicle compartment. That is, the dash portion 40 constitutes the front end of the passenger compartment. The dash portion 40 includes a dash panel 42 and a dash cloth (not shown). Rear ends of a pair of left and right front side members 10 are coupled to the dash panel 42 . A kick-up portion (not shown) may be provided on the vehicle rear side of the front side member 10, and the dash panel 42 may be arranged above the kick-up portion.

A gearbox 44 as a “supporting portion” is provided in front of the dash panel 42 , and the gearbox 44 is arranged so as to protrude toward the front side of the vehicle with respect to the dash panel 42 . Further, the gearbox 44 is arranged so as to overlap the transaxle 30L when viewed from the front side of the vehicle. That is, the gearbox 44 is arranged at a position shifted to the left with respect to the center in the vehicle width direction and behind the transaxle 30L so as to face the rear surface of the transaxle 30L. Therefore, in the present embodiment, if the power unit 30 moves rearward of the vehicle (for example, when it moves parallel), the gearbox 44 supports the transaxle 30L.

Next, a detailed configuration of the bumper RF 20 will be described with reference to FIGS. 5(A) to 6(C).

As shown in FIG. 5A, the bumper RF 20 includes a central portion 46 arranged in the center in the vehicle width direction, and first low-strength bumpers arranged to the left and right of the central portion 46 in the vehicle width direction, respectively. It has a portion 48 and a second reduced strength portion 50 . The bumper RF 20 further includes a left side portion 52 forming a portion on the left side in the vehicle width direction of the first low-strength portion 48, and a right side portion 54 forming a portion on the right side of the vehicle width direction of the second low-strength portion 50. is doing. The rear surfaces of the left side portion 52 and the right side portion 54 are joined to the vehicle front side end portion of the deformed portion 12 of the front side member 10 .

In FIGS. 1 to 5A, the bumper RF 20 is schematically illustrated so that the dimension in the vehicle front-rear direction is constant along the vehicle width direction, but the bumper RF 20 includes the first low-strength portion 48 and the The portion other than the second low-strength portion 50 is configured such that the dimension in the vehicle front-rear direction is greatest at the center in the vehicle width direction and decreases toward the outside in the vehicle width direction.

In addition, as shown in FIG. 5A, the first low-strength portion 48 and the second low-strength portion 50 have smaller dimensions in the longitudinal direction of the vehicle than adjacent portions. That is, the surface of the bumper RF 20 on the rear side in the vehicle front-rear direction is recessed forward in the vehicle front-rear direction in plan view at the first low-strength portion 48 and the second low-strength portion 50 .

As an example, the first low-strength portion 48 and the second low-strength portion 50 are formed by pressing the bumper RF 20 . 1 to 5A show that the dimension of the bumper RF 20 in the longitudinal direction of the vehicle changes suddenly at the boundary between the first low-strength portion 48 and the second low-strength portion 50 and adjacent portions. However, a gradually changing portion (not shown) in which the dimension in the longitudinal direction of the vehicle gradually changes may be provided.

As described above, the bumper RF 20 is configured such that the dimensions in the vehicle front-rear direction of portions other than the first low-strength portion 48 and the second low-strength portion 50 become smaller toward the outside in the vehicle width direction. The dimension of the RF 20 in the vehicle vertical direction is constant or substantially constant along the vehicle width direction. That is, the cross-sectional area of the bumper RF 20 viewed from the vehicle width direction is the largest at the center in the vehicle width direction, except for the first low-strength portion 48 and the second low-strength portion 50, and decreases toward the outside in the vehicle width direction. is configured as

6A to 6C show the first low-strength portion 48, the central portion 46, and the second low-strength portion 50 when the bumper RF 20 shown in FIG. 5A is viewed from the left side in the vehicle width direction. , respectively, are shown in longitudinal section of the central portion of the .

As shown in FIG. 6B, the central portion 46 of the bumper RF 20 includes a rear member 56 located on the rear side of the vehicle and a front member 58 located on the front side of the vehicle. The rear member 56 of the central portion 46 includes a rear main body portion 56A having a substantially U-shaped cross section that opens toward the vehicle front side. A rear upper flange 56B extends upward from the upper end of the rear body portion 56A, and a lower rear flange 56C extends from the lower end of the rear body portion 56A toward the vehicle lower side. there is For this reason, the rear member 56 is formed to have a substantially hat-shaped cross section that is open to the front side of the vehicle.

The front member 58 of the central portion 46 is formed in a flat plate shape whose plate thickness direction is the vehicle front-rear direction. ing. Further, a front upper flange 58B extends upward from the upper end of the front main body portion 58A, and the front upper flange 58B is overlapped with the rear upper flange 56B of the rear member 56, and then spot welding or the like is performed. joined by Furthermore, a front lower flange 58C extends from the lower end portion of the front main body portion 58A toward the vehicle lower side, and the front lower flange 58C is superimposed on the rear lower flange 56C of the rear member 56, and then spot welding or the like is performed. joined by Thereby, the central portion 46 of the bumper RF 20 of the present embodiment has a closed cross-sectional structure (hollow structure).

The cross-sectional area of the central portion 46 when viewed in the vehicle width direction is the largest at the center in the vehicle width direction and decreases toward the outside in the vehicle width direction. Specifically, the dimension in the vehicle front-rear direction of the rear main body portion 56A (indicated by the solid line in FIG. 6B) at the center of the center portion 46 in the vehicle width direction is the rear side at both ends of the center portion 46 in the vehicle width direction. It is larger than the dimension of the main body portion 56A (indicated by a two-dot chain line in FIG. 6B) in the longitudinal direction of the vehicle. Accordingly, the dimension D1 in the vehicle front-rear direction at the center of the center portion 46 in the vehicle width direction is larger than the dimension D2 in the vehicle front-rear direction at both ends of the center portion 46 in the vehicle width direction.

As shown in FIG. 6A, the first low-strength portion 48 of the bumper RF 20 includes a rear member 60 having a substantially hat-shaped cross section located on the vehicle rear side, and a flat plate-shaped front member located on the vehicle front side. 62. The rear member 60 of the first low-strength portion 48 includes a rear main body portion 60A having a substantially U-shaped cross section that is open to the front side of the vehicle, and a rear main body portion 60A that extends upward from the upper end portion of the rear main body portion 60A. It is provided with a rear upper flange 60B and a rear lower flange 60C extending from the lower end portion of the rear main body portion 60A toward the vehicle lower side.

The front member 62 of the first low-strength portion 48 includes a front main body portion 62A that closes the opening of the rear member 60, a front upper flange 62B that extends upward from the upper end of the front main body portion 62A, and a front upper flange 62B. A front-side lower flange 62C extends downward from the lower end of the body portion 62A. The rear upper flange 60B and the front upper flange 62B are overlapped and joined by welding or the like, and the rear lower flange 60C and the front lower flange 62C are overlapped and joined by welding or the like. As a result, the first low-strength portion 48 has a closed cross-sectional structure (hollow structure).

Here, the dimension of the rear main body portion 60A of the rear member 60 in the first low-strength portion 48 in the vehicle front-rear direction is equal to that of the rear main body portion 56A (FIG. 6A) at the left end portion of the central portion 46 in the vehicle width direction. (indicated by a two-dot chain line in )) in the longitudinal direction of the vehicle. Accordingly, the dimension D3 of the first low-strength portion 48 in the longitudinal direction of the vehicle is smaller than the dimension D2 of the left end portion in the lateral direction of the vehicle of the central portion 46 in the longitudinal direction of the vehicle. Therefore, the cross-sectional area of the first low-strength portion 48 is smaller than the cross-sectional area of the adjacent central portion 46 .

As shown in FIG. 6C, the second low-strength portion 50 of the bumper RF 20 includes a rear member 64 having a substantially hat-shaped cross section located on the vehicle rear side and a flat plate-shaped front member located on the vehicle front side. 66 form a closed cross-sectional structure. The rear member 64 includes a rear body portion 64A, a rear upper flange 64B and a rear lower flange 64C, and the front member 66 includes a front body portion 66A, a front upper flange 66B and a front lower flange 66C. and

Here, the vehicle front-rear direction dimension of the rear main body portion 64A of the rear member 64 in the second low-strength portion 50 is equal to the rear main body portion 56A (Fig. 6(C)) at the vehicle width direction right end portion of the central portion 46. (indicated by a two-dot chain line in )) in the longitudinal direction of the vehicle. Accordingly, the dimension D4 of the second low-strength portion 50 in the vehicle front-rear direction is smaller than the vehicle front-rear direction dimension D2 of the right end portion of the central portion 46 in the vehicle width direction. A dimension D4 of the second low-strength portion 50 in the vehicle front-rear direction is larger than a dimension D3 of the first low-strength portion 48 in the vehicle front-rear direction. Therefore, the cross-sectional area of the second low-strength portion 50 viewed in the vehicle width direction is smaller than the cross-sectional area of the central portion 46 and larger than the cross-sectional area of the first low-strength portion 48 .

Further, as shown in FIG. 5A, the dimension of the first low-strength portion 48 in the longitudinal direction of the vehicle is smaller than the dimension of the portion of the left side portion 52 adjacent to the first low-strength portion 48 in the longitudinal direction of the vehicle. It's becoming Similarly, the dimension of the second low-strength portion 50 in the longitudinal direction of the vehicle is smaller than the dimension of the portion of the right side portion 54 adjacent to the second low-strength portion 50 in the longitudinal direction of the vehicle. 1 to 5A, illustration of the rear members 56, 60, 64 and the front members 58, 62, 66 is omitted. Also, the left side portion 52 and the right side portion 54 are respectively provided with a rear side member and a front side member (not shown). That is, the rear members (not shown) of the left side portion 52 and the right side portion 54 and the rear side members 56, 60, 64 are integrally formed to constitute the rear portion of the bumper RF20. Similarly, the front members (not shown) of the left side portion 52 and the right side portion 54 and the front members 58, 62, 66 are integrally formed to constitute the front portion of the bumper RF20.

As described above, the cross-sectional areas of the central portion 46, the second low-strength portion 50, and the first low-strength portion 48, which constitute a part of the bumper RF 20, viewed from the vehicle width direction are set to decrease in this order. As a result, the bending strength (bending strength against bending in the longitudinal direction of the vehicle, the same shall apply hereinafter) also decreases in the order of the central portion 46 , the second low-strength portion 50 , and the first low-strength portion 48 . The bending strength of each part of the bumper RF20 will be described in detail below.

FIG. 5(B) is a schematic diagram showing the bending strength characteristic with respect to the position of the bumper RF 20 in the vehicle width direction. As shown in this figure, the bending resistance characteristic diagram of the bumper RF 20 is such that the general shape of the portion excluding the first low-strength portion 48 and the second low-strength portion 50 is a gentle mountain shape, and the bending resistance is the vehicle width It is highest in the center of the direction and becomes lower toward the outer side in the vehicle width direction. This is because, as described above, the cross-sectional area of the portion of the bumper RF 20 excluding the first low-strength portion 48 and the second low-strength portion 50 as viewed in the vehicle width direction decreases toward the outside in the vehicle width direction. be. However, in the bending resistance characteristic diagram, the first low-strength portion 48 and the second low-strength portion 50 have a shape that deviates from the entire mountain-shaped curve. Specifically, the bending strength of the first low-strength portion 48 is lower than that of the adjacent central portion 46 and left side portion 52 . In addition, the bending strength of the second low-strength portion 50 is lower than that of the adjacent portions of the central portion 46 and the right side portion 54 . This is because the cross-sectional areas of the first low-strength portion 48 and the second low-strength portion 50 of the bumper RF 20 viewed from the vehicle width direction are smaller than the adjacent portions, as described above.

Also, the bending yield strength of the first low-strength portion 48 is lower than the bending yield strength of the second low-strength portion 50 . That is, a proof stress difference (indicated by arrow D) is set between the first low-strength portion 48 and the second low-strength portion 50 .

With the structure as described above, the first low-strength portion 48 of the bumper RF 20 is the most likely to break, and constitutes the first bending starting portion that is first to break when colliding with the center pole. In addition, the second low-strength portion 50 constitutes a second bending starting portion that is broken next to the first low-strength portion 48 .

In other words, the bumper RF 20 is set so that the cross-sectional area seen from the vehicle width direction decreases in the order of the central portion 46, the second low-strength portion 50, and the first low-strength portion 48. The flexural rigidity also decreases in this order. That is, when the center pole collides, the first low-strength portion 48 is most susceptible to bending deformation, followed by the second low-strength portion 50 .

In addition, in FIG. 5B, which is a schematic diagram, the bending yield strength is shown to change suddenly to the minimum value at the boundary between the first low-strength portion 48 and the second low-strength portion 50 and the adjacent portions. However, when the gradually changing portion (not shown) in which the dimension in the longitudinal direction of the vehicle gradually changes is provided as described above, the bending strength characteristic of the bumper RF 20 is the first low strength portion 48 and the second low strength portion It gradually changes at the boundary portion between 50 and the adjacent portion.

<Effect>
Next, the effect of this embodiment is demonstrated, comparing with the comparative example shown to FIG. 7(A) and FIG. 7(B).

As shown in FIG. 7A, in the vehicle front structure according to the comparative example, the bumper RF 100 has a gently undulating shape in the bending resistance characteristic diagram, and does not have a portion where the bending resistance is lowered. . That is, the bumper RF 100 is not provided with a portion whose dimension in the vehicle front-rear direction is set smaller than that of the adjacent portion. Therefore, in the event of a collision with the center pole, there is a possibility that the portion where the bending resistance is lower than the center portion of the vehicle (the position corresponding to the middle of the mountain in the bending resistance characteristic diagram) may become the starting point of bending.

As shown in FIG. 7(B), if the engine 30R were to break at the breakage starting point 100A when colliding with the pole P, the engine 30R would not be supported by the gearbox 44. The shear input generated at the connecting portion 34 between the engine 30R and the transaxle 30L increases. Then, the connection between the engine 30R and the transaxle 30L is released (in other words, the power unit cracks), and only the engine 30R, which receives the collision load from the bending starting point 100A, moves toward the passenger compartment, thereby causing the dash portion 40 to move. There is a possibility that the load is locally transmitted to the dash portion 40 and the amount of deformation of the dash portion 40 increases.

On the other hand, in the present embodiment, as shown in FIGS. 1 to 4, a pair of left and right front side members 10 extend along the vehicle front-rear direction. A bumper RF 20 extends along the vehicle width direction and is joined to vehicle front side end portions of the pair of left and right front side members 10 . A power unit 30 is arranged between the pair of left and right front side members 10 and behind the bumper RF 20 (between the bumper RF 20 and the vehicle compartment).

The power unit 30 is configured by connecting an engine 30R arranged on the right side in the vehicle width direction and a transaxle 30L arranged on the left side in the vehicle width direction to each other. A gearbox 44 is provided between the dash portion 40 and the transaxle 30L. Further, the gearbox 44 is arranged so as to overlap the transaxle 30L when viewed from the front side of the vehicle. Therefore, if the power unit 30 moves rearward of the vehicle (eg parallel movement), the transaxle 30L of the power unit 30 is supported by the gearbox 44 .

As shown in FIGS. 1 to 5A, the bumper RF 20 includes a central portion 46 arranged in the center in the vehicle width direction, and first low-strength portions 48 arranged on both sides of the central portion 46 in the vehicle width direction. and a second low-strength portion 50 are provided. Here, the first low-strength portion 48 is arranged so as to overlap the transaxle 30L when viewed from the front side of the vehicle. In other words, the first low-strength portion 48 is provided on the left side in the vehicle width direction of the connecting portion 34 and faces the transaxle 30L in the vehicle front-rear direction. Further, the second low-strength portion 50 is arranged so as to overlap with the engine 30R when viewed from the front side of the vehicle. In other words, the second low-strength portion 50 is provided on the vehicle width direction right side of the connecting portion 34 and faces the engine 30R in the vehicle front-rear direction. The dimension in the longitudinal direction of the vehicle is set so as to decrease in the order of the central portion 46, the second low-strength portion 50, and the first low-strength portion 48. As shown in FIG.

2 and 3, in the vehicle front structure of the present embodiment, the first low-strength portion 48 is the side of the engine 30R and the transaxle 30L supported by the gearbox 44 at the time of collision with the center pole. The position of the first low-strength portion 48 is set so as to transmit the impact load to the device. Therefore, in the vehicle front structure of the present embodiment, it is easy to realize the deformation mode described below at the time of collision with the center pole.

That is, when the center pole collides, as shown in FIG. 2, the bumper RF 20 does not break at the central position in the vehicle width direction where the pole abuts, but breaks at the first low-strength portion 48 having the smallest dimension in the vehicle front-rear direction. Next, as shown in FIG. 3 , first low-strength portion 48 of bumper RF 20 transmits the collision load (indicated by arrow F) to transaxle 30L of power unit 30 . When the power unit 30 moves rearward of the vehicle due to the collision load, the power unit 30 (transaxle 30L) is supported by the gearbox 44 . Here, since the device supported by the gearbox 44 and the device to which the first low-strength portion 48 transmits the collision load are the same device (the transaxle 30L), the connecting portion 34 between the engine 30R and the transaxle 30L does not increase the shear input generated at As a result, power unit cracking is suppressed.

Furthermore, by suppressing power unit cracking, the reaction force from the power unit 30 to the bumper RF 20 (the reaction force against the force indicated by arrow F in FIG. 3) increases in the first low-strength portion 48 . Therefore, as shown in FIG. 3, the bumper RF 20 is likely to be bent at the second point, that is, at the second low-strength portion 50 having a larger dimension in the longitudinal direction of the vehicle than the first low-strength portion 48 . When the second low-strength portion 50 is bent, as shown in FIG. 4, the power unit 30 is pushed rearward in the range between the first low-strength portion 48 and the second low-strength portion 50 of the bumper RF 20 ( (This means surface pressing), and the collision load can be distributed in the vehicle width direction. As a result, it is possible to suppress local input to the dash portion 40, thereby suppressing deformation of the passenger compartment.

Thus, in this embodiment, without increasing the mass and components of the bumper RF20, by reducing the cross-sectional area seen from the vehicle width direction of the bumper RF20 at the desired folding position, the folding position of the bumper RF20 and folding It is possible to reduce the amount of deformation of the passenger compartment by controlling the order.

Further, although simplified in the drawings, the rear surface of the power unit 30 has an uneven shape. In the present embodiment, of the rear surface having the uneven shape, the rearmost portion in the vehicle front-rear direction faces the gear box 44 in the vehicle front-rear direction. That is, the vehicle front-rear direction rear end portion of the power unit 30 is supported by the dash portion 40 first. Therefore, the power unit 30 can be supported from behind in an early stage after the occurrence of the center pole collision.

Although the description is omitted for the sake of simplification, between the bumper RF 20 and the power unit 30, a cooling unit or the like (not shown) is usually arranged. Therefore, when a center pole collision occurs and the first low-strength portion 48 of the bumper RF 20 is bent and displaced toward the power unit 30, the collision load is transmitted from the bumper RF 20 to the power unit 30 via the cooling unit and the like.

[Supplementary explanation of the above embodiment]
In the above embodiment, as shown in FIGS. 1 to 5A, the first low-strength portion 48 and the second low-strength portion 50 having a small cross-sectional area are provided only at the position of the bending starting point of the bumper RF 20. Although examples have been provided, the invention is not so limited. The first low-strength portion 48 and the second low-strength portion 50 may overlap the transaxle 30L and the engine 30R, respectively, when viewed from the front side of the vehicle. For example, the first low-strength portion 48 may extend from the boundary portion (first bending starting point) with the central portion 46 to the left end portion in the vehicle width direction. Similarly, the second low-strength portion 50 may extend from the boundary portion (second bending starting point) with the central portion 46 to the right end portion in the vehicle width direction.

In the above embodiment, the gearbox 44 protrudes toward the front of the vehicle with respect to the dash panel 42, which is a general portion of the dash portion 40, and functions as a "supporting portion." However, the present invention is limited to this. not.

For example, a portion of the power unit 30 protrudes rearward, and this portion is first supported by, for example, the dash panel 42 in the dash portion 40 (in this case, a portion of the dash panel 42 is supported by the “support portion”). equivalent.) may be used. Even in this case (even if part of the dash portion is the support portion), the support portion is arranged between the dash portion and the transaxle 30L so as to overlap the transaxle 30L when viewed from the front side of the vehicle. It can be said that

Further, in the above-described embodiment, the gearbox 44 (supporting portion) is arranged at a position shifted to the left side in the vehicle width direction with respect to the center in the vehicle width direction, that is, at a position overlapping the transaxle 30L when viewed from the front side of the vehicle. Although examples have been provided, the invention is not so limited.

For example, the gearbox 44 may be arranged at a position shifted rightward in the vehicle width direction with respect to the center in the vehicle width direction. In this case, premised on the configuration of the power unit 30 of the above embodiment, the gearbox 44 is arranged at a position overlapping the engine 30R when viewed from the front side of the vehicle, and supports the engine 30R. That is, the engine 30R becomes the "first device". In this case, the first low-strength portion 48 having the lowest bending resistance of the bumper RF 20 is arranged on the right side in the vehicle width direction with respect to the central portion 46, and the right side in the vehicle width direction is the "first direction side". The second low-strength portion 50 having the next lowest bending resistance is arranged on the left side in the vehicle width direction with respect to the central portion 46, and the left side in the vehicle width direction is the "second direction side". Therefore, the first low-strength portion 48, which breaks first upon collision with the center pole, is arranged on the right side, and the second low-strength portion 50, which breaks second, is arranged on the left side.

Further, the gearbox 44 (supporting portion) may be positioned at the center in the vehicle width direction. In this case, premised on the configuration of the power unit 30 of the above-described embodiment, the gearbox 44 is positioned so as to overlap the engine 30R when viewed from the front-rear direction of the vehicle. That is, the engine 30R becomes the "first device". Therefore, the configuration of the bumper RF 20 is such that the first low-strength portion 48 that breaks first when colliding with the center pole is on the right side (first direction side), and the second low-strength portion 50 that breaks second is on the left side (second direction side). have.

Also, the “support” of the present invention is not limited to the gearbox 44 . For example, it may be a master cylinder, or it may be a dash cross, which is a frame member that connects the front ends of a pair of left and right rockers (frame members extending in the vehicle front-rear direction at both ends in the vehicle width direction at the lower part of the vehicle body). good. Further, the support portion is a portion (member) capable of generating a reaction force with respect to the power unit. Therefore, portions (members) such as pipes and brackets that are easily deformed when receiving a collision load via the power unit do not correspond to the support portion.

Further, in the above-described embodiment, the second low-strength portion 50 is provided at a position symmetrical to the first low-strength portion 48 with respect to the center in the vehicle width direction, but the present invention is not limited to this. . Even if the first low-strength portion 48 and the second low-strength portion 50 are not positioned symmetrically with respect to the center in the vehicle width direction, the first low-strength portion 48 is located near the transaxle 30L (the gearbox 44) when viewed from the front side of the vehicle. and the first device facing in the longitudinal direction of the vehicle), and the second low-strength portion 50 may overlap with the engine 30R. In this case, the center portion 46 has a configuration in which the distances from the center point of the bumper RF10 in the vehicle width direction to both ends of the center portion 46 in the vehicle width direction are different on the left and right sides.

Further, in the above-described embodiment, as shown in FIG. 1, the first low-strength portion 48 is set at a position outside the "supporting portion" (gearbox 44) in the vehicle width direction. The invention is not limited to this. The first low-strength portion 48 may be set at a position inside the support portion in the vehicle width direction.

Also, in the above-described embodiment, an example in which the deformable portion 12 constitutes a part of the front side member 10 has been described, but the present invention is not limited to this. The front side member 10 does not have to be provided with the deformation portion 12 . In this case, the vehicle front side end portion of the main body portion 14 is joined to the vehicle rear side surface of the bumper RF 20 .

10 front side member 20 bumper RF (bumper reinforcement)
30 power unit 30R engine (second device)
30L transaxle (first device)
40 dash part 44 gearbox (support part)
46 Central portion 48 First low-strength portion 50 Second low-strength portion D2 Dimensions in the longitudinal direction of the vehicle at both ends of the central portion in the vehicle width direction
(Dimension in the longitudinal direction of the central part of the vehicle)
D3 Dimension of the first low-strength portion in the longitudinal direction of the vehicle D4 Dimension of the second low-strength portion in the longitudinal direction of the vehicle

Claims (1)

a pair of front side members;
Bumpari reinforcement and
power unit and
dash and
a support;
with
The bumper reinforcement is joined to vehicle front end portions of the pair of front side members,
The power unit is arranged between the pair of front side members and between the bumper reinforcement and the vehicle compartment,
The power unit includes a first device arranged on the first direction side in the vehicle width direction and a second device arranged on the second direction side in the vehicle width direction,
the first device and the second device are coupled;
The dash portion is arranged between the power unit and the vehicle compartment,
The support portion is arranged between the dash portion and the first device so as to overlap with the first device when viewed from the front side of the vehicle,
The bumper reinforcement includes a first low-strength portion, a second low-strength portion, and a central portion in the vehicle width direction,
The first low-strength portion and the second low-strength portion are arranged on both sides of the central portion in the vehicle width direction,
The first low-strength portion overlaps the first device when viewed from the front side of the vehicle,
The second low-strength portion overlaps with the second device when viewed from the front side of the vehicle,
The dimension of the first low-strength portion in the vehicle front-rear direction is smaller than the dimension of the second low-strength portion in the vehicle front-rear direction,
The dimension of the second low-strength portion in the vehicle front-rear direction is smaller than the dimension of the central portion in the vehicle front-rear direction,
Vehicle front structure.

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