JP7530573B2 - Front body structure - Google Patents

Description

The present invention relates to a vehicle front structure.

A side frame is provided on the vehicle body side at the front portion in the vehicle longitudinal direction, extending from the outer portion of the dash panel in the vehicle width direction toward the front of the vehicle. The side frame is known to have a structure having an upper member and a lower member, as disclosed in Patent Document 1, for example. In this example, a bent portion that bends toward the front and upper direction is formed at the connection portion between the upper member and the lower member, and a bulkhead is provided in front of the bent portion to separate the closed cross-sectional portion of the lower member.

The above-mentioned configuration is intended to absorb the impact load from a frontal collision, such as a head-on collision (hereafter referred to as a frontal collision) in which an object strikes the vehicle from the front, by deforming the side frame. In this example, the above-mentioned configuration is intended to stabilize the deformed shape.

JP 2019-14342 A

In a structure like the above example, when an impact load due to a frontal collision or the like acts on the front part of the side frame, the weak part provided at the bend acts as the starting point of deformation, and the bend is deformed to absorb the impact load. However, when deformation starts from the weak part at the bend, there is a possibility that deformation will not occur in the intended direction due to the positional relationship between the highly rigid structure and the bend. In this case, there is a possibility that the impact energy due to the impact load will not be effectively absorbed in the intended part. For this reason, with a structure like the above example, there is room for improvement in terms of effectively absorbing impact loads due to frontal collisions, etc.

The present invention has been made to solve the above problems, and its purpose is to provide a vehicle front structure that can efficiently absorb impact energy caused by impact loads due to frontal collisions, etc.

A vehicle front structure according to the present invention for achieving the above object includes an apron side frame provided on a vehicle side, the apron side frame including a rear side frame extending forward from an upper portion of an outer portion in the vehicle width direction of a dash panel provided on the front portion of the vehicle body, and a front side frame joined to a front portion of the rear side frame and extending forward from the front portion of the rear side frame, the rear side frame including an upper rear member and a lower rear member joined to a lower portion of the upper rear member, the upper rear member and the lower rear member form a first closed cross-sectional structure, and the front side frame includes an upper front member and a front side frame joined to the lower portion of the upper front member. and a lower front member joined to the front portion of the front side frame, the upper front member and the lower front member forming a second closed cross-sectional structure, the front portion of the rear side frame and the rear portion of the front side frame being joined by an inclined surface, the inclined surface including a rear inclined surface formed in the front portion of the upper rear member and a front inclined surface formed in the rear portion of the lower front member, the rear inclined surface and the front inclined surface being joined at a plurality of welding points, the welding points being provided on the outer and inner sides in the vehicle width direction of the rear inclined surface and the front inclined surface, and spaced apart from each other in the vehicle fore-and-aft direction .

The present invention makes it possible to efficiently absorb impact energy caused by impact loads such as those from a frontal collision.

1 is a perspective view of a vehicle body front structure according to the present invention; FIG. 2 is a perspective view showing a state in which an upper front member of FIG. 1 has been removed. 2 is an enlarged perspective view showing the periphery of a connection portion between a front side frame and a rear side frame in FIG. 1 . FIG. 3 is an enlarged perspective view showing the periphery of a connection portion between the front side frame and the rear side frame of FIG. 2; FIG. FIG. 4 is a perspective view showing a cross section taken along line AA of FIG. 3. FIG. 4 is a perspective view showing a cross section taken along the line B-B of FIG. 3; FIG. 4 is a perspective view showing a cross section taken along the line CC of FIG. 3 . FIG. 2 is a plan view of the apron side frame and its surroundings in FIG. 1 . FIG. 9 is an enlarged plan view showing the apron side frame of FIG. 8 . 2 is a side view of the vehicle front body structure of FIG. 1 as viewed from the outer side in the vehicle width direction.

Below, an embodiment of a vehicle body front structure according to the present invention will be described with reference to the drawings (Figs. 1 to 10). In the drawings, the direction of the arrow Fr indicates the front in the vehicle longitudinal direction. In the description of the embodiment, the "front (front end) and rear (rear end)" correspond to the front and rear in the vehicle longitudinal direction. The directions of the arrows L and R indicate the left and right in the vehicle width direction. In the description of the embodiment, the "left and right" correspond to the left and right when an occupant in the vehicle cabin faces forward of the vehicle.

The vehicle body front structure of this embodiment, as shown in Figs. 1 to 10, has an apron side frame 1 provided on the side of the vehicle body. As shown in Figs. 1 and 2, the apron side frame 1 is a member that extends in the fore-and-aft direction of the vehicle, and is disposed on the vehicle front side of the dash panel 53. The dash panel 53 is a panel material that separates the vehicle cabin from a power unit room or the like in which a drive device such as an engine or electric motor is disposed, and extends in the vehicle width direction.

As shown in Figures 1, 2 and 10, the front body structure of this embodiment has a dash side panel 55, a strut tower 50, and an apron side panel 57.

The dash side panel 55 is provided on the outer side of the dash panel 53 in the vehicle width direction, has a surface facing the vehicle width direction, and extends in the vehicle front-rear direction. The strut tower 50 is provided on the outer side of the front surface of the dash panel 53 in the vehicle width direction, and is disposed on the inner side of the dash side panel 55 in the vehicle width direction. The strut tower 50 is a vehicle body structure for mounting the upper part of a strut (not shown) that extends in the vehicle vertical direction of a strut-type suspension device (not shown), and a front wall 51 that faces the front of the vehicle and extends in the vehicle vertical direction is provided in front of the strut tower 50.

The apron side panel 57 is a panel material that is arranged on the vehicle front side of the dash side panel 55 and the strut tower 50, and the upper part of the apron side panel 57 is joined to the apron side frame 1. In addition, as shown in FIG. 10 etc., the apron side panel 57 is joined to the front side member 61.

The structure of this embodiment also includes a front side member 61, a front end horizontal frame member 63, and a front bumper cross member 65. The front side member 61 is a highly rigid member that constitutes the vehicle body frame, and extends in the vehicle front-rear direction at the lower part of the outer part in the vehicle width direction inside the power unit room. The front end horizontal frame member 63 has horizontal members arranged at intervals from each other in the vehicle vertical direction, and vertical members that extend in the vehicle vertical direction to connect the vehicle width direction ends of the two horizontal members, and the front part of the front side member 61 is joined to the upper horizontal member. In addition, the front part of the apron side frame 1 is joined to the corner formed by the vertical member and the upper horizontal member. The front bumper cross member 65 is a part for supporting the front bumper, and extends in the vehicle width direction. The outer part in the vehicle width direction of the front bumper cross member 65 is joined near the above-mentioned corner.

The structure of the apron side frame 1 of this embodiment will be described. As shown in Figures 1 and 2, the apron side frame 1 has a rear side frame 1B and a front side frame 1A.

The rear side frame 1B extends forward from the upper part of the dash panel 53 on the outer side in the vehicle width direction. In this example, the rear side frame 1B is inclined in the vehicle front-rear direction so that the front end is positioned slightly lower than the rear end of the rear side frame 1B. In addition, as shown in Figures 2 to 7, the rear side frame 1B has an upper rear member 30 and a lower rear member 40, which are joined together.

As shown in Figs. 3 to 7, the upper rear member 30 has an upper surface portion 31 facing the upper side of the vehicle and an inner side surface portion 35 facing the inside in the vehicle width direction. The upper surface portion 31 of the upper rear member 30 extends from the dash side panel 55 toward the front of the vehicle. A rear inclined surface 31a is provided at the front of the upper surface portion 31. The rear inclined surface 31a is continuous with the upper surface portion 31 and inclines downward as it approaches the front of the vehicle. The inner side surface portion 35 of the upper rear member 30 protrudes downward from the inner end of the upper surface portion 31 in the vehicle width direction and extends in the vehicle front-rear direction along the edge of the upper surface portion 31. In the inner side surface portion 35, the length in the vehicle up-down direction of the inner side surface portion 35 corresponding to the rear inclined surface 31a gradually decreases toward the front of the vehicle so as to correspond to the rear inclined surface 31a. In this example, the upper rear member 30 has an L-shaped cross section. The inside of the front inclined surface 31a is joined to the upper part of the apron side panel 57.

The lower rear member 40 has a lower surface portion 41 facing the bottom of the vehicle, an outer surface portion 45 facing the outside in the vehicle width direction, an inner flange 42, and an outer flange 46. The lower surface portion 41 of the lower rear member 40 extends from the outside in the vehicle width direction of the dash side panel 55 toward the front of the vehicle, and is disposed on the vehicle lower side of the upper surface portion 31 of the upper rear member 30 with a gap therebetween.

The inner flange 42 of the lower rear member 40 protrudes downward from the inner end of the lower surface portion 41 of the lower rear member 40 in the vehicle width direction and extends in the vehicle front-rear direction along the vehicle width direction end of the lower surface portion 41. The inner flange 42 is joined to the lower part of the inner surface portion 35 of the upper rear member 30 by spot welding or the like.

The outer surface portion 45 of the lower rear member 40 extends upward from the outer end of the lower surface portion 41 in the vehicle width direction, and extends in the vehicle front-rear direction along the outer end of the lower surface portion 41 in the vehicle width direction. The outer flange 46 protrudes outward in the vehicle width direction from the upper end of the outer surface portion 45 of the lower rear member 40, and extends in the vehicle front-rear direction along the upper end of the outer surface portion 45. The outer flange 46 is joined to the outer portion of the upper surface portion 31 of the upper rear member 30 in the vehicle width direction by spot welding or the like. By joining the inner flange 42 and the outer flange 46 of the lower rear member 40 to the upper rear member 30, the rear side frame 1B is configured with a rear closed cross-sectional structure SR that is substantially rectangular when viewed in the vehicle front-rear direction, as shown in Figures 5 and 6.

As shown in Figures 3, 4, 6 and 7, the front side frame 1A is joined to the front of the rear side frame 1B and extends from the front toward the front of the vehicle. In this example, the front side frame 1A is inclined while curving slightly downward toward the front of the vehicle. The inclination of the front side frame 1A is steeper than the inclination of the rear side frame 1B. The front side frame 1A also has an upper front member 10 and a lower front member 20, which are joined to each other.

The upper front member 10 has an upper surface portion 11 facing upward of the vehicle, an outer side surface portion 15 facing the outer side in the vehicle width direction, and an outer flange 16. The upper surface portion 11 of the upper front member 10 extends toward the rear of the vehicle so as to connect to the upper surface portion 31 of the upper rear member 30. In this example, the rear end of the upper surface portion 11 of the upper front member 10 is located further rearward of the vehicle than the rear end of the rear inclined surface 31a. The upper surface portion 31 of the upper front member 10 is provided with an extension portion 17, which is joined to the upper surface portion 11 of the upper rear member 30 via an extension portion 27 of the lower front member 20, which will be described later. The extension portion 17 will be described later.

The outer surface portion 15 of the upper front member 10 protrudes downward from the outer end of the upper surface portion 11 in the vehicle width direction, extends in the front-rear direction of the vehicle along the edge of the upper surface portion 11, and extends toward the rear of the vehicle to connect with the outer surface portion 45 of the lower rear member 40. In this example, the rear end of the outer surface portion 15 corresponds to the position of the front end of the extension portion 17. In addition, the lower end of the outer surface portion 15 is inclined to correspond to the rear inclined portion.

The outer flange 16 of the upper front member 10 protrudes outward in the vehicle width direction from the lower end of the outer surface portion 15 and extends in the vehicle front-rear direction along the lower end of the outer surface portion 15. In addition, the rear of the outer flange 16 is inclined to correspond to the rear inclined surface 31a and is joined to the rear inclined surface 31a by spot welding or the like.

As shown in Figures 4 and 7, the lower front member 20 has a lower surface portion 21 facing the bottom of the vehicle, an inner side surface portion 25 facing the inside in the vehicle width direction, and an inner flange 26. The lower surface portion 21 of the lower front member 20 is disposed on the vehicle bottom side of the upper surface portion 11 of the upper front member 10 with a gap therebetween, and is connected to the lower surface portion 41 of the lower rear member 40 when viewed from below the vehicle. In this example, a front inclined surface 21a is provided at the rear of the lower surface portion 21 (Figure 4). The front inclined surface 21a is inclined downward as it approaches the front of the vehicle.

An extension 27 is provided on the vehicle rear side of the front inclined surface 21a, similar to the upper front member 10. The extension 27 extends from the rear end of the front inclined surface 21a toward the rear of the vehicle and is directly joined to the front part of the upper surface 31 of the rear upper member 30 by spot welding or the like. The front end of the front inclined surface 21a is connected to the rear part of the lower surface 21 of the lower front member 20.

The outer flange 16 of the upper front member 10 is joined to the vehicle width direction outer portion of the lower surface portion 21 of the lower front member 20 by spot welding or the like.

The inner surface portion 25 of the lower front member 20 extends upward from the inner end of the lower surface portion 21 of the lower front member 20 in the vehicle width direction, and extends in the vehicle front-rear direction so as to connect to the inner surface portion 35 of the upper rear member 30. The inner flange 26 protrudes inward in the vehicle width direction from the upper end of the inner surface portion 25 of the lower front member 20, and extends in the vehicle front-rear direction along the upper end. The inner flange 26 is joined to the inner portion of the upper surface portion 11 of the upper front member 10 in the vehicle width direction by spot welding or the like. As shown in Figures 6 and 7, the inner flange 26 and the outer flange 15 are joined as described above, so that the front side frame 1A has a front closed cross-sectional structure SF that is substantially rectangular when viewed in the vehicle front-rear direction.

When the vehicle body receives an impact load due to, for example, a frontal collision and the impact load is input to the front side frame 1A, the impact load is transmitted to the front inclined surface 21a of the front side frame 1A and then to the upper rear member 30 of the rear side frame 1B. At this time, the upper rear member 30 of the rear side frame 1B braces itself against the impact load, causing the front side frame 1A to deform so as to bend or curve downwards on the vehicle. This absorbs the impact energy of the impact load due to the frontal collision and prevents the impact load from being transmitted, for example, to the rear side of the vehicle beyond the dash panel 53.

In addition, in this embodiment, as described above, the rear inclined surface 31a is formed at the front of the upper rear member 30, and the front inclined surface 21a is formed at the rear of the lower front member 20, and the rear inclined surface 31a and the front inclined surface 21a are joined to each other by spot welding or the like. As a result, the rear inclined surface 31a and the front inclined surface 21a form a joint, and a shear stress is generated at the joint due to an impact load from the front side of the vehicle, which can promote the above-mentioned curved or bent deformation.

In this embodiment, the lower front member 20 and the upper rear member 30 are welded by spot welding or the like. In this example, the rear inclined surface 31a and the front inclined surface 21a are welded, and the extension 27 of the lower front member 20 is welded to the upper surface 31 of the upper rear member 30. In this example, the extension 27 of the lower front member 20, the extension 17 of the upper front member 10, and the upper surface 31 of the upper rear member 30 are welded in a three-layered state. This configuration improves the rigidity of the area where the three sheets are welded. Since the load is input along the shape of, for example, the rear inclined surface 31a of the upper rear member 30, the above-mentioned curved or bent deformation is easily caused in the area located forward of the three-layered area.

In addition, in this embodiment, the rear inclined surface 31a is inclined downward toward the front of the vehicle, as shown in Figure 4. By setting the inclination direction in this way, the load from below the front of the vehicle is efficiently transmitted to the rear of the vehicle, and this load transmission acts favorably on the above-mentioned curved or bent deformation.

In addition, in this embodiment, as shown in Figures 4 and 8 to 10, for example, the front end of the rear inclined surface 31a is located further forward of the vehicle than the strut tower 50. In this embodiment, the rigidity of the rear side frame 1B is set higher than the rigidity of the front side frame 1A by adjusting the plate thickness of the portion that constitutes the rear closed cross-sectional structure SR. In addition, the strut tower 50 has a higher rigidity than the rear side frame 1B. Therefore, when an impact load is input to the front side frame 1A, the vicinity of the front end of the rear inclined surface 31a can serve as the starting point for deformation such as the above-mentioned bending, making it easier for deformation to occur.

In addition, in this embodiment, the rear end of the rear inclined surface 31a is positioned to correspond to the front wall 51 of the strut tower 50 in the vehicle fore-and-aft direction, so that the rear side frame 1B can effectively bear the load, facilitating the above-mentioned deformation.

The upper rear member 30 or lower rear member 40 of the rear side frame 1B is joined to the front side member 61 via the lower front member 20 of the front side frame 1A. This ensures the rigidity of the vehicle body with a simple structure. The welding points between the rear inclined surface 31a and the front inclined surface 21a are spaced apart in the fore-and-aft direction of the vehicle on both the outside and inside of the inclined surfaces. This allows the load acting at the welding points to be balanced inside and outside (left and right), allowing the load to be transmitted effectively.

The description of this embodiment is merely an example for explaining the present invention, and does not limit the invention described in the claims. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

In this embodiment, the rear inclined surface is configured to face upward on the vehicle, but this is not limited thereto. It may be configured to face the outer or inner side in the vehicle width direction. Furthermore, the inclined surface may be set to face downward.

In addition, the vehicle body framework of this embodiment can be formed even without the front side frame 1A and the front end horizontal frame member 63. In this case, for example, the upper part of the apron side panel 57 can be joined to the upper surface portion 31, the rear inclined surface 31a, and the inner surface portion 35 of the upper rear member 30. In such a vehicle body framework, when an impact load is transmitted from the upper part of the apron side panel 57 to the rear inclined surface 31a, the upper rear member 30 of the rear side frame 1B braces itself against the impact load, thereby deforming the apron side panel 57.

In addition, the vehicle body front structure and its effects of this embodiment can be obtained by adding the front side frame 1A and the front end horizontal frame member 63 to a vehicle body frame different from this embodiment that does not have the front side frame 1A and the front end horizontal frame member 63. Therefore, the vehicle body front structure of this embodiment can be easily produced into different models depending on whether or not the front side frame 1A and the front end horizontal frame member 63 are included.

1 Apron side frame 1A Front side frame 1B Rear side frame 10 Upper front member 11 Upper surface portion 15 Outer side surface portion 16 Outer flange 17 Extension portion 20 Lower front member 21 Lower surface portion 21a Front inclined surface 25 Inner side surface portion 26 Inner flange 27 Extension portion 30 Upper rear member 31 Upper surface portion 31a Rear inclined surface 35 Inner side surface portion 40 Lower rear member 41 Lower surface portion 42 Inner flange 45 Outer side surface portion 46 Outer flange 50 Strut tower 51 Front wall 53 Dash panel 55 Dash side panel 57 Apron side panel 61 Front side member 63 Front end horizontal frame member 65 Front bumper cross member SF Front closed cross section structure (second closed cross section structure)
SR Rear closed section structure (first closed section structure)

Claims (4)

A vehicle body front structure having an apron side frame provided on a vehicle body side,
the apron side frame includes a rear side frame extending forward of the vehicle from an upper portion of an outer portion in a vehicle width direction of a dash panel provided at a front portion of the vehicle body, and a front side frame joined to a front portion of the rear side frame and extending forward of the vehicle from the front portion,
the rear side frame has an upper rear member and a lower rear member joined to a lower portion of the upper rear member, the upper rear member and the lower rear member forming a first closed cross-sectional structure,
the front side frame has an upper front member and a lower front member joined to a lower part of the upper front member, the upper front member and the lower front member forming a second closed cross-sectional structure,
The front portion of the rear side frame and the rear portion of the front side frame are joined to each other by an inclined surface,
the inclined surface includes a rear inclined surface formed in a front portion of the upper rear member and a front inclined surface formed in a rear portion of the lower front member, the rear inclined surface and the front inclined surface being joined at a plurality of welding points;
A vehicle body front structure, characterized in that the weld points are provided on the outer and inner sides in the vehicle width direction of the rear inclined surface and the front inclined surface, and are spaced apart from each other in the vehicle fore-and-aft direction . 2. The vehicle front body structure according to claim 1 , wherein the rear inclined surface is inclined downwardly toward the front of the vehicle. 2. The vehicle front structure according to claim 1 , wherein a front end of the rear inclined surface is disposed further forward of a strut tower provided on a side of the vehicle body. 4. The vehicle front body structure according to claim 3 , wherein a rear end of the rear inclined surface is disposed so as to correspond to a front wall of the strut tower in the vehicle front-rear direction.