Vehicle front structure

Abstract

This vehicle front structure comprises a suspension support structure, and a vehicle cabin front member connected to a rear part of the suspension support structure. The suspension support structure comprises a damper housing, an upper-side load transmission part, and a lower-side load transmission part. The damper housing has a damper connection part. The upper-side load transmission part connects the damper housing to an upper region of the vehicle cabin front member. The lower-side load transmission part connects the damper housing to a lower region of the vehicle cabin front member. One of the upper-side load transmission part and the lower-side load transmission part is provided with a fracture induction part that fractures when an impact load equal to or greater than a prescribed value is provided.

Description

Vehicle Front Structure

[0001] The present invention relates to a vehicle front structure.

[0002] As a vehicle front structure, a pair of damper housings arranged apart from each other on the left and right of the vehicle are integrally formed by casting an aluminum alloy (see, for example, Patent Document 1).

[0003] In the vehicle front structure described in Patent Document 1, rearward extending portions extending toward the rear side of the vehicle are continuously provided on the left and right damper housings, and the rear portions of the left and right rearward extending portions are continuously provided to a floor connection block extending along the vehicle width direction. The left and right damper housings are integrally formed by casting an aluminum alloy together with the left and right rearward extending portions and the floor connection block.

[0004] The left and right damper housings constitute a suspension support structure, and inside the upper wall and the side wall continuous with the upper wall, dampers, springs, wheel support members, etc., which are suspension members, are arranged. A damper connection portion to which the upper end portion of the damper is connected is provided on the upper wall of the damper housing. Further, since the damper housing is die - cast from the outside in the vehicle width direction during casting, the main wall portion (the side wall continuous with the upper wall) has an open cross - section opened toward the outside in the vehicle width direction.

[0005] During the running of the vehicle, a large suspension load from the wheel is input to the damper housing, and when an impact load is input from the front side of the vehicle, the damper housing also functions as a member that disperses and transmits the input load to the rear side of the vehicle body. Therefore, a plurality of reinforcing ribs are provided at appropriate positions of the suspension support structure including the open cross - section portion of the damper housing to increase the strength and rigidity of the wall portion. The plurality of reinforcing ribs are integrally formed during the casting of the damper housing.

[0006] Chinese Utility Model Patent No. 217649533 Specification

[0007] In the vehicle front structure described in Patent Document 1, floor connecting blocks, which are connected to the rear of the left and right damper housings, are connected to the front passenger compartment member. When an impact load is applied, the load applied to the damper housing is absorbed by the front passenger compartment member at the rear of the damper housing. In this case, in order to reliably absorb the impact load applied to the damper housing, it is advantageous to absorb it over a wide area of ​​the front passenger compartment member.

[0008] Front pillars are located on the left and right sides of the front of the vehicle, extending vertically and connected at their upper ends to the roof frame. The front pillars form the door surround on the front side of the front door and also serve as a load transmission path, transferring the load from the damper housing to the roof panel when an impact load is input from the front of the vehicle. For this reason, the front pillars, being front-end components of the vehicle, need to be reinforced, such as by increasing their thickness, to effectively transmit the load to the rear of the vehicle. However, reinforcing them to withstand excessive impact loads would make the front pillars large and heavy. Therefore, it is desirable that the impact load be received basically over a wide area of ​​the front-end components of the vehicle, and that the load transmission path be appropriately changed according to the impact load.

[0009] The problem to be solved is to appropriately change the transmission path of impact loads in response to the input impact load. By solving this problem, the present invention aims to reduce vehicle weight and cost while maintaining collision safety performance by reducing unnecessary reinforcement.

[0010] A vehicle front structure according to one embodiment of the present invention is a vehicle front structure comprising a suspension support structure and a passenger compartment front member connected to the rear of the suspension support structure, wherein the suspension support structure comprises a damper housing having a damper connecting portion, an upper load transmission portion connecting the damper housing to the upper region of the passenger compartment front member, and a lower load transmission portion connecting the damper housing to the lower region of the passenger compartment front member, and either the upper load transmission portion or the lower load transmission portion is provided with a fracture induction portion that fractures upon input of an impact load exceeding a specified value.

[0011] With the above configuration, if the impact load input from the front of the vehicle is less than the specified value, the load is transmitted from the damper housing to the front passenger compartment member through the upper load transmission section and the lower load transmission section. If the impact load transmitted to the damper housing is greater than the specified value, the fracture induction section will fracture, and the load will be transmitted from the damper housing to the front passenger compartment member through either the upper load transmission section or the lower load transmission section.

[0012] The fracture-inducing portion is provided in the upper load-transmission portion, and the upper load-transmission portion may be formed in a shape in which the vertical width gradually increases from the front of the vehicle to the rear of the vehicle when viewed from the side.

[0013] In this case, the vertical width of the upper load transmission section gradually increases towards the part connected to the front vehicle member, making it possible to distribute and transmit the input load over a wide range in the vertical direction of the front vehicle member through the upper load transmission section. Furthermore, in this configuration, sufficient vertical width can be secured for the part of the upper load transmission section connected to the front vehicle member, so a large support reaction force can be secured for the upper load transmission section from the front vehicle member. Therefore, when this configuration is adopted, it becomes possible to more reliably cause the fracture induction section to fracture when the input impact load exceeds a specified value.

[0014] Multiple fracture-inducing portions are provided on either the upper load-transmission portion or the lower load-transmission portion, spaced apart in the longitudinal direction of the vehicle, and each fracture-inducing portion may extend substantially along the vertical direction of the vehicle.

[0015] In this case, since multiple fracture-inducing sections extending in the vertical direction of the vehicle are provided in the longitudinal direction of the vehicle, it becomes possible to finely fracture one of the load-transmitting sections when the input impact load exceeds a specified value. Therefore, it is possible to avoid the fractured fragments hindering the deformation of surrounding members. Accordingly, when this configuration is adopted, it becomes possible to reliably fracture the desired part when an impact load exceeding a specified value is input, while maintaining a high energy absorption performance at the front of the vehicle.

[0016] Either the upper load transmission section or the lower load transmission section may have a vertical wall section formed by a horizontal cross-section that is bent in a corrugated shape, and each peak of the corrugated bend in the vertical wall section may constitute the fracture induction section.

[0017] In this case, when an impact load exceeding a specified value is applied to the vertical wall, stress concentrates at each peak of the wave-shaped bend in the vertical wall, causing the peak (fracture-inducing point) to fracture. As a result, the vertical wall fractures into small pieces in the longitudinal direction of the vehicle, and the fractured pieces are less likely to hinder the deformation of surrounding members. Therefore, by adopting this configuration, despite its simple structure, it becomes possible to reliably fracture the desired parts when an impact load is applied, while maintaining high energy absorption performance at the front of the vehicle.

[0018] The vertical wall portion may be provided with inclined ribs that slope downward from the front to the rear of the vehicle.

[0019] In this case, when an impact load is applied to the vertical wall from the front, the inclined ribs function as guides that direct the input load downward and rearward. Therefore, when this configuration is adopted, it becomes possible to distribute and transmit the impact load applied from the front to a wider area in the vertical direction of the front member of the vehicle cabin from the rear of the upper load transmission section.

[0020] The protruding height of the inclined rib may be set higher than the height of the wave-shaped bend in the vertical wall portion in the vehicle width direction.

[0021] In this case, the inclined ribs make it easy to prevent the peak of the wavy bend (fracture-inducing portion) in the vertical wall from fracturing due to an impact load smaller than the specified value.

[0022] The rear of the upper load transmission unit may be connected to the front pillar, which is a front component of the passenger compartment, and the rear of the lower load transmission unit may be connected to the dashboard panel, which is a front component of the passenger compartment.

[0023] In this case, if the impact load input from the front of the vehicle is less than the specified value, the load is transmitted from the damper housing to the front pillar and dashboard panel through the upper and lower load transmission sections. If the impact load transmitted to the damper housing is greater than the specified value, the fracture-inducing section of the upper load transmission section fractures, causing the load to be transmitted from the damper housing to the dashboard panel through the lower load transmission section, making it less likely to be transmitted to the front pillar. Therefore, by adopting this configuration, it becomes possible to suppress the input of excessive impact loads to the front pillar when the input impact load is greater than the specified value.

[0024] The damper housing comprises an upper wall having the damper connecting portion and a covering wall extending downward from the edge of the upper wall, wherein the inner surface of the covering wall is provided with an inner reinforcing rib that slopes downward from the front to the rear of the vehicle, and the lower load transmission portion may be provided with a load transmission portion side reinforcing rib whose front end is connected to the rear end of the inner reinforcing rib with the covering wall in between, and which slopes downward from the front end toward the rear of the vehicle.

[0025] In this case, when an impact load is applied to the damper housing from the front, the load is transmitted to the rear along the inner reinforcing rib within the cover wall of the damper housing, and then transmitted to the front end of the load-transmission side reinforcing rib of the lower load-transmission section, sandwiching the rear wall portion of the cover wall. The load transmitted to the front end is then transmitted to the lower region of the front member of the passenger compartment along the extension direction of the load-transmission side reinforcing rib. Therefore, when this configuration is adopted, the impact load applied to the damper housing from the front of the vehicle can be efficiently transmitted to the lower region of the front member of the passenger compartment by the inner reinforcing rib and the load-transmission side reinforcing rib.

[0026] In one aspect of the present invention, the front vehicle structure is provided with a fracture-inducing section in either the upper load transmission section or the lower load transmission section that fractures upon input of an impact load exceeding a specified value. Therefore, depending on the magnitude of the impact load, the load transmission switches between passing through both the upper and lower load transmission sections and passing through either the upper or lower load transmission section. Consequently, when the front vehicle structure according to one aspect of the present invention is adopted, the transmission path of the impact load can be appropriately changed according to the input impact load. Thus, it becomes possible to reduce the weight and cost of the vehicle by reducing unnecessary reinforcement while maintaining collision safety performance.

[0027] A perspective view of the front of the vehicle according to the embodiment. A perspective view of the front of the vehicle showing some of the components of Figure 1 with dashed lines. A side view of the front of the vehicle according to the embodiment, viewed from the outside in the vehicle width direction. A front view of the load-bearing member according to the embodiment, viewed from the front of the vehicle. A plan view of the front of the vehicle according to the embodiment. A front view of the suspension support structure according to the embodiment. A perspective view of a part of the suspension support structure according to the embodiment. A plan view of a part of the suspension support structure according to the embodiment. A cross-sectional view along the line IX-IX in Figure 7. A cross-sectional view along the line X-X in Figure 7. A perspective view of the reinforcing member according to the embodiment. A plan view of the front of the vehicle according to the embodiment. A perspective view of the suspension support structure according to the embodiment, viewed from the passenger compartment side. A perspective view of the suspension support structure according to the embodiment with the dashboard panel attached, viewed from the passenger compartment side.

[0028] Embodiments of the present invention will be described below with reference to the drawings. In the following description, front and rear, up and down, and left and right refer to the front and rear, up and down, and left and right of vehicle 1 unless otherwise specified. Also, in the drawings, arrow FR points to the front of the vehicle, arrow UP points to the top of the vehicle, and arrow LH points to the left side of the vehicle.

[0029] Figure 1 is a perspective view of the front of the vehicle 1 of this embodiment. Figure 2 is a perspective view similar to Figure 1, with dashed lines indicating some of the components (load-receiving members 20, which will be described later) from Figure 1. Figure 3 is a side view of the front of the vehicle 1 as seen from the outside in the vehicle width direction (the left side of the vehicle 1). Reference numeral 10 in Figures 1 and 2 indicates a pair of damper housings spaced apart on both the left and right sides of the front compartment 11 in front of the driver's seat. The damper housing 10 has an upper wall 10a having a damper connecting portion 16, and a covering wall 10b extending downward from the periphery of the upper wall 10a (the front and rear edges and the inner edge in the vehicle width direction). The damper housing 10 is open to the downward side. The horizontal cross-section of the damper housing 10 is open to the outside in the vehicle width direction. Hereinafter, the portion of the damper housing 10 that is open to the outside in the vehicle width direction will be referred to as the "open portion 52". The space enclosed by the upper wall 10a and the covering wall 10b contains the damper 50 and coil spring 51 of the front suspension (see Figure 3). The upper end of the damper 50 is connected to the damper connecting portion 16 of the upper wall 10a.

[0030] The left and right damper housings 10 are connected to each other by a connecting beam 12 that extends along the vehicle width direction. The connecting beam 12 is located on the lower front side of the passenger compartment. The connecting beam 12 is formed in a substantially rectangular shape with a rectangular cross-section that extends along the vehicle width direction. On the lower side of the left and right sides of the connecting beam 12, substantially U-shaped axle insertion blocks 13 are provided through which the axles of the corresponding left and right front wheels W are inserted.

[0031] Furthermore, a load transmission section 53 extending toward the rear of the vehicle is connected to the rear of each left and right damper housing 10. The load transmission section 53 has an upper load transmission section 56 that connects the corresponding left and right damper housings 10 to the front pillars 54 on the same side on both sides, and a lower load transmission section 57 (see Figure 3) that connects the damper housings 10 to the dashboard panel 55. The lower load transmission section 57 is connected to the lower region of the upper load transmission section 56. The front pillars 54 are located at the left and right ends of the front of the passenger compartment and are provided to run along the leading edge of the front door (not shown). The dashboard panel 55 is a panel member that separates the passenger compartment from the front compartment 11, and its left and right ends are connected to the corresponding left and right front pillars 54.

[0032] The left and right damper housings 10, along with the load transmission section 53 and the connecting beam 12, are made of cast aluminum alloy parts. In this embodiment, the cast parts consisting of the damper housings 10, the load transmission section 53, and the connecting beam 12 constitute the suspension support structure 15. In this embodiment, the front pillar 54 constitutes the front passenger compartment member of the upper area of ​​the passenger compartment, while the dashboard panel 55, the underfloor frame member (not shown), and the side sill (not shown) constitute the front passenger compartment member of the lower area of ​​the passenger compartment.

[0033] Furthermore, load-bearing members 20 extending substantially along the vehicle's longitudinal direction are connected to the front sides of each of the left and right damper housings 10. The left and right load-bearing members 20 are formed in a generally symmetrical manner. The load-bearing members 20 are made of cast aluminum alloy parts.

[0034] The left and right side edges of the bumper beam 14, which is located at the front of the vehicle 1, are connected to the front of the lower part of each of the left and right load-bearing members 20. The bumper beam 14 extends horizontally along approximately the width of the vehicle, and the back (rear) sides of the left and right side edges are connected to the front ends of the corresponding load-bearing members 20.

[0035] Figure 4 is a front view of the load-receiving member 20 as seen from the front of the vehicle. As shown in Figures 1 and 4, the load-receiving member 20 comprises a lower load-receiving portion 21, which is a plate-shaped wall portion extending substantially along the longitudinal direction of the vehicle and bent in a crank shape in the vertical and horizontal directions, and an upper load-receiving portion 22, which is similarly a plate-shaped wall portion extending substantially along the longitudinal direction of the vehicle and bent in a crank shape in the vertical and horizontal directions. The upper load-receiving portion 22 is positioned above the lower load-receiving portion 21 and on the outside in the vehicle width direction. The bending shape of the lower load-receiving portion 21 and the upper load-receiving portion 22 may be substantially L-shaped, channel-shaped, or include a curved portion in part.

[0036] The front end of the lower load-receiving section 21 is provided with a plate-shaped load input wall 23 extending in a direction intersecting the vehicle's longitudinal direction (a direction approximately perpendicular to it). The bumper beam 14 is fastened and fixed to the front surface of the load input wall 23. The rear end of the lower load-receiving section 21 is provided with a plate-shaped lower load transmission wall 24 extending in a direction intersecting the vehicle's longitudinal direction (a direction approximately perpendicular to it). The rear surface of the lower load transmission wall 24 is fastened and fixed to the lower front surface of the side of the connecting beam 12 (the front surface of the second load-receiving wall 25, which will be described later). The load input wall 23 is positioned at least in the portion of the front end of the lower load-receiving section 21 that overlaps vertically with the joint portion of the bumper beam 14.

[0037] The upper load-bearing portion 22 is shorter in length than the lower load-bearing portion 21, and its front end is located further rearward than the lower load-bearing portion 21. The lower load-bearing portion 21 and the upper load-bearing portion 22 are connected by a plate-shaped connecting wall portion 28. The connecting wall portion 28 continuously connects the lower load-bearing portion 21, which is located lower and on the inside in the vehicle width direction, and the upper load-bearing portion 22, which is located upper and on the outside in the vehicle width direction, in the longitudinal direction of the vehicle. The connecting wall portion 28 is formed to be approximately the same length as the upper load-bearing portion 22 in the longitudinal direction of the vehicle, and connects the approximately rear half region of the lower load-bearing portion 21 to the upper load-bearing portion 22 in a continuous manner.

[0038] The front end of the connecting wall 28 and the upper load-receiving portion 22 is provided with a plate-shaped front end wall 19 that extends in a direction intersecting the vehicle's longitudinal direction (a direction approximately perpendicular to it). The rear end of the upper load-receiving portion 22 is provided with a plate-shaped upper load-transmitting wall 26 (load-transmitting wall) that extends in a direction intersecting the vehicle's longitudinal direction (a direction approximately perpendicular to it). The rear surface of the upper load-transmitting wall 26 is fastened and fixed to the front surfaces of the corresponding left and right damper housings 10 (the front surfaces of the first load-receiving wall 27, which will be described later). The upper load-transmitting wall 26 (load-transmitting wall) is positioned at the rear end of the upper load-receiving portion 22 in a position that overlaps vertically with at least the connecting portion (first load-receiving wall 27) of the suspension support structure 15. The upper load-receiving portion 22 and the lower load-receiving portion 21, together with the connecting wall 28, constitute a part of the front wheel house that covers the inside of the front wheel W in the vehicle width direction.

[0039] The connecting wall portion 28, like the lower load-receiving portion 21 and the upper load-receiving portion 22, consists of plate-shaped wall portions that extend substantially along the longitudinal direction of the vehicle and are connected in a crank-like manner in the vertical and horizontal directions. In this embodiment, the connecting wall portion 28 also has an open cross-sectional shape that is open in a direction intersecting the longitudinal direction of the vehicle. However, the connecting wall portion 28 may not have a crank-like shape, but may be a flat plate-like shape, or a plate-like shape that is partially bent or curved.

[0040] Figure 5 is a plan view of the area behind the load-receiving member 20 at the front of the vehicle 1, viewed from above, and Figure 6 is a front view of the suspension support structure 15. As shown in Figures 2 and 6, the front surface of the connecting beam 12 and the front surfaces of the covering walls 10b of the left and right damper housings 10 are continuous flat surfaces facing the front of the vehicle. Part of these flat surfaces constitute the front surface of the first load-receiving wall 27, to which the upper rear load-transmission wall 26 of the load-receiving member 20 is joined in surface contact. In addition, flat surfaces facing the front of the vehicle are formed on the lower front surfaces of the left and right sides of the connecting beam 12. These flat surfaces constitute the front surface of the second load-receiving wall 25, to which the lower rear load-transmission wall 24 of the load-receiving member 20 is joined in surface contact. In this embodiment, the front surface of the connecting beam 12 constitutes the beam front portion 12f, and the front surface of the covering wall 10b of the damper housing 10 constitutes the housing front portion 10f. Both the beam front portion 12f and the housing front portion 10f extend in a direction substantially perpendicular to the vehicle's longitudinal direction. The beam front portion 12f and the housing front portion 10f are formed to be flush with each other, facing the front of the vehicle.

[0041] Furthermore, the upper surface of the connecting beam 12 is formed flat. As shown in Figure 6, the upper surface of the connecting beam 12 is an auxiliary equipment mounting section 61 for mounting auxiliary equipment 60 such as a heat exchanger, compressor, power control unit (ECU), and power unit (a unit integrating the ECU and battery). The connecting beam 12 is positioned between the left and right damper housings 10 and is connected to the inner walls in the vehicle width direction of the covering walls 10b of the left and right damper housings 10. Hereinafter, the inner walls in the vehicle width direction of the covering walls 10b will be referred to as the "vertical wall section 62".

[0042] The accessory mounting portion 61 of the connecting beam 12 is disposed below each damper connecting portion 16 of the left and right damper housings 10. The vertical wall portion 62 of the damper housing 10 extends downward from the vicinity of the inner edge in the vehicle width direction of each damper connecting portion 16 of the left and right damper housings 10 (the inner edge in the vehicle width direction of the upper wall 10a). And the vertical wall portion 62 connects the vicinity of the inner edge in the vehicle width direction of the damper connecting portion 16 and the accessory mounting portion 61. The left and right vertical wall portions 62 are inclined downward inward in the vehicle width direction from the vicinity of the inner edge in the vehicle width direction of the damper connecting portion 16 toward the accessory mounting portion 61.

[0043] As shown in FIG. 5, the connecting beam 12 is disposed so as to overlap at least partially in the vehicle front-rear direction with the belt-like region b that connects the extending portions of each damper connecting portion 16 of the left and right damper housings 10. In the present embodiment, the belt-like region b that connects the extending portions of the left and right damper connecting portions 16 is set to be located inside the front-rear width A of the connecting beam 12 in plan view.

[0044] Also, as shown in FIGS. 2 and 6, axle insertion blocks 13 that extend downward are integrally provided in the vicinity of the connection portion between the left and right damper housings 10 and the connecting beam 12. The second load receiving wall 25 described above is provided on the front surface closer to the bottom of each of the left and right axle insertion blocks 13. Further, a boss portion 63 that extends in the vehicle front-rear direction is provided above the second load receiving wall 25 on the front surface of each axle insertion block 13. A support hole 64 is provided on the front surface of the boss portion 63. A shaft portion 66a for stabilizer support is inserted into this support hole 64. The shaft portion 66a for stabilizer support is provided on a locking block 66 of the stabilizer 65. The locking block 66 is attached to a rod portion that extends along the vehicle width direction of the stabilizer 65. In the present embodiment, the support hole 64 constitutes a stabilizer support portion that supports a part of the stabilizer 65. The support hole 64, which is the stabilizer support portion, is provided in the vicinity of the connection portion between the damper housing 10 and the connecting beam 12.

[0045] Figure 7 is an enlarged perspective view showing a portion of the left side of the suspension support structure 15, and Figure 8 is an enlarged plan view showing a portion of the left side of the suspension support structure 15. As shown in Figures 1, 2, 5 to 8, the upper walls 10a of the left and right damper housings 10 (near the damper connecting portion 16) are connected by a second connecting beam 67. The second connecting beam 67 is formed from an aluminum alloy plate material with a roughly hat-shaped cross-section. The second connecting beam 67 extends substantially along the vehicle width direction, above the auxiliary equipment mounting portion 61 (upper surface) of the connecting beam 12, so as to be substantially parallel to the auxiliary equipment mounting portion 61 (upper surface). As shown in Figure 5, the front-to-rear width of the second connecting beam 67 is narrower than the front-to-rear width A of the connecting beam 12. In a plan view, the second connecting beam 67 is positioned to overlap with the connecting beam 12. As shown in Figure 6, the second connecting beam 67, together with the left and right damper housings 10 and the connecting beam 12, forms a closed cross-section that is approximately rectangular in shape when viewed from the front.

[0046] Furthermore, Figure 9 is a cross-sectional view along the line IX-IX in Figure 7, and Figure 10 is a cross-sectional view along the line X-X in Figure 7. As shown in Figures 9 and 10, the upper wall 10a and the covering wall 10b of the damper housing 10 form an opening 52 that opens outward and downward in the vehicle width direction. The upper region of this opening 52 on the vehicle width direction is covered by a reinforcing member 30. The reinforcing member 30 is made of a metal material such as steel or titanium alloy, which has a higher tensile strength than the aluminum alloy that forms the damper housing 10. The reinforcing member 30 is fixed to the corresponding damper housings 10 on the left and right by bolting or welding. In this embodiment, the reinforcing member 30 is provided to cover only the upper region of the opening 52 on the vehicle width direction, but the reinforcing member 30 may also be provided to cover the intermediate or lower region in the vertical direction on the vehicle width direction of the opening 52. In other words, the reinforcing member 30 only needs to be provided so as to cover at least a portion of the open portion 52 on the outer side in the vehicle width direction of the open cross-section of the damper housing 10.

[0047] Figure 11 is a perspective view of the reinforcing member 30 as seen from above. The reinforcing member 30 extends along the side edge of the upper wall 10a of the damper housing 10 and includes an upper wall portion 30a that is coupled to the lower surface of the upper wall 10a. The upper wall portion 30a has a side edge 30as that extends in the vehicle longitudinal direction at the outer end in the vehicle width direction, a front edge 30af that extends in the vehicle width direction at the front end in the vehicle longitudinal direction, and an inclined edge 30ai that connects the side edge 30as and the front edge 30af. The inclined edge 30ai is inclined from the outer end in the vehicle width direction of the front edge 30af toward the front end portion of the side edge 30as. The inclined edge 30ai is inclined outward in the vehicle width direction toward the rear side of the vehicle. Note that, in the upper wall portion 30a of the reinforcing member 30, the region on the front side of the connection portion of the side edge 30as and the inclined edge 30ai is inclined downward toward the front side of the vehicle.

[0048] Further, the reinforcing member 30 includes a side wall portion 30b that bends or curves downward from the side edge 30as (outer position in the vehicle width direction) of the upper wall portion 30a, a front wall portion 30c that bends or curves downward from the front edge 30af (front side position in the vehicle) of the upper wall portion 30a, and an inclined wall 30d that bends or curves downward from the inclined edge 30ai of the upper wall portion 30a. The front end portion of the inclined wall 30d is connected to the end portion on the outer side in the vehicle width direction of the front wall portion 30c, and the rear end portion of the inclined wall 30d is connected to the front end of the side wall portion 30b. As shown in FIG. 8, the inclined wall 30d is inclined outward in the vehicle width direction from a position in front of the damper connection portion 16 toward the rear of the vehicle. Further, the reinforcing member 30 includes a lower wall portion 30e (see FIG. 9) that is connected to the lower ends of the side wall portion 30b, the inclined wall 30d, and the front wall portion 30c. The lower wall portion 30e extends below the upper wall portion 30a so as to be substantially parallel to the upper wall portion 30a. The upper end portion of the inclined wall 30d is inclined downward toward the front side of the vehicle along the inclination of the front side region of the upper wall portion 30a as shown in FIG. 3.

[0049] Here, as shown in Figures 3 and 7, the upper walls 10a of the left and right damper housings 10 are provided with a damper connecting portion 16 to which the upper end of the damper 50 is connected, and a forward-sloping portion 70 that slopes downward toward the front of the vehicle from the front end of the damper connecting portion 16. The damper connecting portion 16 connected to the rear end of the forward-sloping portion 70 slopes downward toward the rear of the vehicle. The upper wall portion 30a of the reinforcing member 30 is connected to the lower surface of the outer edge in the vehicle width direction of the damper connecting portion 16 and the forward-sloping portion 70 of the upper wall 10a of the damper housing 10.

[0050] As shown in Figure 10, the reinforcing member 30 has a front wall portion 30c and a side wall portion 30b that are connected to the front and rear edges of the opening 52 of the damper housing 10. As a result, the opening 52 of the damper housing 10 is closed by the reinforcing member 30 in a horizontal cross-section that includes the inclined wall 30d.

[0051] Furthermore, as shown in Figures 7 and 8, the forward-sloping portion 70 connected to the front of the damper connecting portion 16 of the damper housing 10 has an outward-facing side in the vehicle width direction that is inclined in a plan view. The side of the forward-sloping portion 70 is inclined outward in the vehicle width direction from the front end toward the rear of the vehicle. This inclined side of the forward-sloping portion 70 will be hereinafter referred to as the "upper wall inclined portion 70i". As shown in Figure 8, the inclined wall 30d of the reinforcing member 30 is positioned to protrude outward and forward in the vehicle width direction compared to the upper wall inclined portion 70i in a plan view. In other words, the inclined wall 30d of the reinforcing member 30 protrudes outward and forward in the vehicle width direction relative to the upper wall inclined portion 70i of the damper housing 10.

[0052] Figure 12 is a plan view of the front of vehicle 1. In Figure 12, the object to which the load is applied 100 when an impact load is applied from the front of the vehicle is shown as a schematic cross-section. The object to which the load is applied 100 is located at a position offset to one side in the vehicle width direction relative to the front of the vehicle (a position offset to one side from the center in the vehicle width direction). As shown in Figure 12, the reinforcing member 30 is positioned such that at least a part of the inclined wall 30d overlaps with the front and rear of the vehicle in a plan view with respect to the connection portion 31 between the load receiving member 20 (lower load receiving portion 21) connected to the front of the damper housing 10 and the bumper beam 14 at the front of the vehicle. Also, as shown in Figures 7 and 12, the upper load transmission wall 26 (load transmission wall) provided at the rear end of the upper load receiving portion 22 is positioned so that at least a part of it overlaps with the front wall portion 30c of the reinforcing member 30 in the vehicle longitudinal direction. The upper load-transmitting wall 26 (load-transmitting wall) is superimposed on the front surface of the covering wall 10b of the damper housing 10, and is connected to the damper housing 10 and the front wall portion 30c of the reinforcing member 30.

[0053] As shown in Figures 5 and 8, connecting beams 12 extending along the vehicle width direction are connected to the inner ends of the left and right damper housings 10 in the vehicle width direction. The reinforcing members 30 fixed to each of the left and right damper housings 10 are positioned so that their respective inclined walls 30d overlap with the vehicle longitudinal extension region of the connecting beam 12 (the region indicated by the arrow representing the longitudinal width A in Figure 5) in the vehicle longitudinal direction. In this embodiment, the entire inclined wall 30d of each reinforcing member 30 is positioned to overlap with the vehicle longitudinal extension region of the connecting beam 12, but the inclined wall 30d of each reinforcing member 30 may be positioned so that only a portion of it overlaps with the vehicle longitudinal extension region of the connecting beam 12.

[0054] Figure 13 is a perspective view of the suspension support structure 15 as seen from the passenger compartment side. Figure 14 is a perspective view of the suspension support structure 15 with the dashboard panel 55 attached as seen from the passenger compartment side. The upper load transmission section 56, which is connected to the rear of each of the left and right damper housings 10, includes, as shown in Figures 3, 7, 13, and 14, a strip-shaped upper frame section 35 extending toward the rear of the vehicle from the outer edge in the vehicle width direction of the upper wall 10a of the damper housing 10, a rear frame section 36 that bends downward from the rear end of the upper frame section 35, and a vertical wall section 37 connected to the inner edges in the vehicle width direction of the upper frame section 35 and the rear frame section 36. The rear frame section 36 is connected to the corresponding left and right front pillars 54.

[0055] As shown in Figure 3, the vertical wall portion 37 is formed in a substantially trapezoidal shape in a side view, with its vertical width gradually increasing from the front to the rear of the vehicle. Furthermore, as shown in Figure 10, the horizontal cross-section of the vertical wall portion 37 is formed with a wavy curve. Each of the vertices 38 of this wavy curve extends linearly in the vertical direction. In addition, each of the vertices 38 of the wavy curve is arranged at substantially constant intervals in the longitudinal direction of the vehicle. The vertices 38 of the wavy curve constitute fracture-inducing portions that induce fracture (or deformation) of the upper load transmission portion 56 when an impact load exceeding a specified value is input to the upper load transmission portion 56. Hereinafter, the vertices 38 of the wavy curve will be referred to as "fracture-inducing portions 38".

[0056] The fracture-inducing portion 38 of the vertical wall portion 37 is configured to induce fracture of the vertical wall portion 37 on the side where the load is applied when an impact load is applied from the front of the vehicle and biased to one side in the vehicle width direction, but to prevent fracture of the vertical wall portion 37 when an impact load is applied from the front of the vehicle and not biased to the vehicle width direction. In other words, the upper load transmission portion 56 (vertical wall portion 37) on the side where the large load is applied is configured to fracture at the fracture-inducing portion 38 only when an impact load is applied from the front of the vehicle with an offset in the vehicle width direction.

[0057] As shown in Figures 3 and 7, the lower edge of the vertical wall portion 37 slopes downward from the front end toward the rear of the vehicle. Slightly above this lower edge of the vertical wall portion 37, an inclined rib 39 is provided that slopes downward from the front end toward the rear of the vehicle, following the lower edge. The inclined rib 39 protrudes outward from the vertical wall portion 37 in the vehicle width direction. The protruding height of the inclined rib 39 is higher than the height of the wavy bend of the vertical wall portion 37 in the vehicle width direction (the height from the top protruding inward in the vehicle width direction to the top protruding outward in the vehicle width direction).

[0058] Furthermore, the lower load transmission section 57, which is connected to the rear of each of the left and right damper housings 10, includes, as shown in Figures 13 and 14, a curved wall 40 connected to the lower edge of the vertical wall 37 of the upper load transmission section 56 and the rear surface of the covering wall 10b of the damper housing 10, and a lower block 41 connected to the lower end of the curved wall 40. The curved wall 40 is formed by curving three-dimensionally so that its upper surface forms a spherical shape that is convex upward. Multiple outer reinforcing ribs 42a, 42b, and 42c are provided on the upper surface of the curved wall 40, extending to connect the rear surface of the covering wall 10b of the damper housing 10 and the upper surface of the lower block 41. All of these outer reinforcing ribs 42a, 42b, and 42c extend downward from their front ends toward the rear of the vehicle.

[0059] As shown in Figure 9, a plurality of inner reinforcing ribs 43a, 43b, and 43c are provided on the inside of the cover wall 10b of the damper housing 10, extending from the front wall portion to the side wall portion and across the rear wall portion of the cover wall 10b. Two of these inner reinforcing ribs 43b and 43c are inclined downward from the front portion to the rear portion. As shown in Figure 13, the rear ends of the two inner reinforcing ribs 43b and 43c are connected to the front ends of two outer reinforcing ribs 42b and 42c, with the rear wall portion of the cover wall 10b of the damper housing 10 in between. In Figure 13, the reference numeral b indicates the connection portion between the inner reinforcing rib 43b and the outer reinforcing rib 42b on the rear wall portion of the cover wall 10b, and the reference numeral c indicates the connection portion between the inner reinforcing rib 43c and the outer reinforcing rib 42c on the rear wall portion of the cover wall 10b. In this embodiment, the two outer reinforcing ribs 42b and 42c that protrude from the upper surface side of the curved wall 40 constitute the load transmission side reinforcing ribs.

[0060] The lower block 41 bulges out from the rear of the axle insertion block 13 toward the rear of the vehicle. The lower block 41 is positioned behind the second load-receiving wall 25 on the front side of the axle insertion block 13. The lower block 41 has a flat upper surface 41u that connects to the lower end of the curved wall 40 and the covering wall 10b of the damper housing 10, and a connecting surface 41c that faces toward the rear of the vehicle. As shown in Figure 14, the connecting surface 41c is connected to the front of the dashboard panel 55.

[0061] The lower load transmission section 57 of the load transmission section 53 is positioned behind the lower load receiving section 21 of the corresponding left and right load receiving members 20, and in a position where they overlap in the vertical direction. The upper load transmission section 56 of the load transmission section 53 is positioned behind the upper load receiving section 22 of the corresponding left and right load receiving members 20, and in a position where they overlap in the vertical direction.

[0062] Furthermore, in this embodiment, the fracture strengths of the damper housing 10, the upper load transmission section 56, and the lower load transmission section 57 against input loads are set as follows. Hereinafter, the fracture strength of the damper housing 10 will be referred to as the housing fracture strength, the fracture strength of the upper load transmission section 56 will be referred to as the upper transmission section fracture strength, and the fracture strength of the lower load transmission section 57 against input loads will be referred to as the lower transmission section fracture strength. Upper transmission section fracture strength < housing fracture strength, lower transmission section fracture strength In other words, the fracture strength of the upper load transmission section 56, which is equipped with a fracture induction section 38, is set to be smaller than that of the damper housing 10 and the lower load transmission section 57. Also, the fracture strength of the front pillar 54 against input loads is set to be larger than that of the upper load transmission section 56 (upper transmission section fracture strength).

[0063] In this embodiment, when an impact load is applied, only the upper load transmission section 56 (fracture induction section 38) of the suspension support structure 15 is set to fracture. However, for example, the fracture strengths of each section may be set such that upper transmission section fracture strength < lower transmission section fracture strength < housing fracture strength, and then each fracture strength is set to a value less than or equal to the maximum impact load applied, thereby determining the order of fracture and causing almost the entire suspension support structure 15 to fracture.

[0064] In the embodiment described above, a fracture induction part 38 is provided in the upper load transmission part 56 of the suspension support structure 15. However, the fracture induction part 38 can also be provided in the lower load transmission part 57 instead of the upper load transmission part 56. In this case, when the impact load input from the front exceeds a specified value, the fracture induction part 38 of the lower load transmission part 57 fractures, and the transmission of load from the lower load transmission part 57 to the dashboard panel 55 is interrupted. In this embodiment, the fracture strengths of the damper housing 10, the upper load transmission part 56, and the lower load transmission part 57 against input loads are set as follows: Lower transmission part fracture strength < Housing fracture strength, Upper transmission part fracture strength. In this case, the fracture strength of the load input part of the dashboard panel 55 against input loads is set to be larger than the fracture strength of the lower load transmission part 57 (lower transmission part fracture strength).

[0065] As described above, in the vehicle front structure of the embodiment described above, a fracture-inducing part 38 that breaks when an impact load exceeding a specified value is input is provided in either the upper load transmission part 56 or the lower load transmission part 57 of the suspension support structure 15. Therefore, if the impact load input from the front of the vehicle is less than the specified value, the fracture-inducing part 38 does not break, and the impact load is transmitted to the front passenger compartment member (front pillar 54 and dashboard panel 55) through the upper load transmission part 56 and the lower load transmission part 57. Also, if the impact load input from the front of the vehicle is greater than the specified value, the fracture-inducing part 38 breaks, and the impact load is transmitted to the front passenger compartment member (dashboard panel 55 or front pillar 54) through either the upper load transmission part 56 or the lower load transmission part 57. In the vehicle front structure of this embodiment, load transmission can be switched between transmission through the upper load transmission section 56 and the lower load transmission section 57, and transmission through either the upper load transmission section 56 or the lower load transmission section 57, depending on the magnitude of the impact load input from the front of the vehicle. Therefore, when the vehicle front structure of this embodiment is adopted, the transmission path of the impact load can be appropriately changed according to the input impact load. Thus, when the vehicle front structure of this embodiment is adopted, it is possible to reduce the weight and cost of the vehicle by reducing unnecessary reinforcement while maintaining collision safety performance.

[0066] Furthermore, in the vehicle front structure of this embodiment, the fracture induction portion 38 is provided in the upper load transmission portion 56, and the upper load transmission portion 56 has a shape in which the vertical width gradually increases from the front side to the rear side of the vehicle when viewed from the side. In this configuration, since the vertical width of the upper load transmission portion 56 gradually increases toward the portion connected to the front pillar 54 (front passenger compartment member), it becomes possible to distribute and transmit the input load over a wide range in the vertical direction of the front pillar 54 through the upper load transmission portion 56. In addition, in this configuration, since sufficient vertical width can be secured in the portion of the upper load transmission portion 56 that is connected to the front pillar 54, a large support reaction force can be secured on the upper load transmission portion 56 from the front pillar 54. Therefore, when the vehicle front structure of this configuration is adopted, it becomes possible to more reliably fracture the fracture induction portion 38 of the upper load transmission portion 56 when the input impact load is greater than a specified value.

[0067] Furthermore, in the vehicle front structure of this embodiment, a plurality of fracture-inducing portions 38 are provided on the upper load transmission portion 56 so as to be spaced apart in the longitudinal direction of the vehicle, and each fracture-inducing portion 38 extends substantially along the vertical direction of the vehicle. In this configuration, since a plurality of fracture-inducing portions 38 extending substantially along the vertical direction are provided on the upper load transmission portion 56 spaced apart in the longitudinal direction, when an impact load exceeding a specified value is input to the upper load transmission portion 56, the upper load transmission portion 56 can be finely fractured in the longitudinal direction. Therefore, it is possible to avoid the fractured fragments of the upper load transmission portion 56 hindering the deformation of surrounding members. Accordingly, when a vehicle front structure of this configuration is adopted, it is possible to reliably fracture a desired part when an impact load exceeding a specified value is input, while maintaining a high energy absorption performance of the front of the vehicle.

[0068] In particular, in this embodiment, the vehicle front structure is formed such that the horizontal cross-section of the vertical wall portion 37 of the upper load transmission section 56 is bent in a wave shape, and the peaks of the wave-shaped bends of the vertical wall portion 37 are designated as fracture-inducing portions 38. Therefore, when an impact load exceeding a specified value is applied to the vertical wall portion 37 of the upper load transmission section 56, stress concentrates at each peak of the wave-shaped bend of the vertical wall portion 37, causing the peaks (fracture-inducing portions 38) to fracture. As a result, the vertical wall portion 37 fractures into small pieces in the longitudinal direction of the vehicle, and the fractured pieces of the vertical wall portion 37 are less likely to hinder the deformation of surrounding members. Therefore, when this vehicle front structure is adopted, despite its simple configuration, it is possible to reliably fracture the desired parts when an impact load exceeding a specified load is applied, while maintaining a high energy absorption performance of the vehicle front.

[0069] Furthermore, in the vehicle front structure of this embodiment, the vertical wall portion 37 of the upper load transmission portion 56 is provided with an inclined rib 39 that slopes downward from the front of the vehicle toward the rear. As a result, when an impact load is applied to the vertical wall portion 37 from the front, the inclined rib 39 functions as a guide that directs the applied load toward the rear and lower side of the vehicle. Therefore, when this vehicle front structure is adopted, it becomes possible to distribute and transmit the impact load applied from the front from the rear of the upper load transmission portion 56 to a wide area in the vertical direction of the front pillar 54.

[0070] In the vehicle front structure of this embodiment, the protruding height of the inclined rib 39 is set higher than the height in the vehicle width direction of the wavy bend of the vertical wall portion 37. Therefore, when an impact load smaller than a specified value is applied to the vertical wall portion 37 from the front, the inclined rib 39 can easily prevent the peak of the wavy bend (fracture-inducing portion 38) of the vertical wall portion 37 from fracturing.

[0071] Furthermore, in the vehicle front structure of this embodiment, the rear of the upper load transmission unit 56 is connected to the front pillar 54, and the rear of the lower load transmission unit 57 is connected to the dashboard panel 55. Therefore, when the input impact load is smaller than a specified value, the input load can be distributed and transmitted to the front pillar 54 and the dashboard panel 55 through the upper load transmission unit 56 and the lower load transmission unit 57. Also, when the input impact load is greater than or equal to a specified value, the fracture induction unit 38 can break, thereby blocking the transmission of load to the front pillar 54 through the upper load transmission unit 56. Thus, when this vehicle front structure is adopted, it becomes possible to suppress the input of excessive impact load to the front pillar 54 when the input impact load is greater than or equal to a specified value.

[0072] Furthermore, in the vehicle front structure of this embodiment, the inner surface of the covering wall 10b of the damper housing 10 is provided with inner reinforcing ribs 43b and 43c that slope downward from the front to the rear of the vehicle, and the lower load transmission section 57 is provided with outer reinforcing ribs 42b and 42c (load transmission section side reinforcing ribs) that extend downward from the front end toward the rear of the vehicle. The front ends of the outer reinforcing ribs 42b and 42c are connected to the rear ends of the inner reinforcing ribs 43b and 43c, sandwiching the covering wall 10b of the damper housing 10. Therefore, when an impact load is input to the damper housing 10 from the front, the load is transmitted to the rear along the inner reinforcing ribs 43b and 43c within the covering wall 10b of the damper housing 10, and transmitted to the front ends of the outer reinforcing ribs 42b and 42c of the lower load transmission section 57, sandwiching the rear wall portion of the covering wall 10b. The impact load transmitted to the front ends of the outer reinforcing ribs 42b and 42c is transmitted to the dashboard panel 55 (the lower region of the front passenger compartment member) along the extension direction of the outer reinforcing ribs 42b and 42c. Therefore, when this vehicle front structure is adopted, the impact load input to the damper housing 10 from the front of the vehicle can be efficiently transmitted to the dashboard panel 55 by the inner reinforcing ribs 43b and 43c and the outer reinforcing ribs 42b and 42c.

[0073] It should be noted that the present invention is not limited to the embodiments described above, and various design modifications are possible without departing from the spirit of the invention. For example, in the above embodiment, the rear of the lower load transmission unit 57 is connected to the dashboard panel 55, but the member to which the rear of the lower load transmission unit 57 is connected is not limited to the dashboard panel 55. The rear of the lower load transmission unit 57 may be any member located on the front side of the passenger compartment, such as a frame member under the floor or a side sill.

[0074] Furthermore, in the above embodiment, the fracture induction portion 38 provided in the upper load transmission portion 56 is composed of the peaks of the bent portions of the wave shape, but the configuration of the fracture induction portion 38 is not limited to this. The fracture induction portion 38 may be, for example, a slit or notch extending in the vertical direction, a thin-walled shape, etc., as long as it can induce fracture of a part of the upper load transmission portion 56 when an impact load is applied.

[0075] Furthermore, in the above embodiment, outer reinforcing ribs 42b and 42c are provided protruding from the upper surface of the curved wall 40 of the lower load transmission section 57, and these outer reinforcing ribs 42b and 42c constitute the load transmission section side reinforcing ribs. However, the load transmission section side reinforcing ribs provided on the lower load transmission section 57 are not limited to this configuration. For example, if the height of the upper end of the curved wall 40 (the height of the connection with the covering wall 10b of the damper housing 10) is sufficiently high, similar reinforcing ribs may be provided protruding from the lower surface of the curved wall 40, and these reinforcing ribs may also be used as the load transmission section side reinforcing ribs.

[0076] 10... Damper housing 10a... Upper wall 10b... Covering wall 15... Suspension support structure 16... Damper connection part 37... Vertical wall part 38... Fracture induction part (top) 39... Inclined rib 42b, 42c... Outer reinforcing rib (reinforcing rib on load transmission side) 43b, 43c... Inner reinforcing rib 54... Front pillar (front part of the passenger compartment) 55... Dashboard panel (front part of the passenger compartment) 56... Upper load transmission part 57... Lower load transmission part

Claims

1. A vehicle front structure comprising a suspension support structure and a front passenger compartment member connected to the rear of the suspension support structure, wherein the suspension support structure comprises a damper housing having a damper connecting portion, an upper load transmission portion connecting the damper housing to the upper region of the front passenger compartment member, and a lower load transmission portion connecting the damper housing to the lower region of the front passenger compartment member, and either the upper load transmission portion or the lower load transmission portion is provided with a fracture induction portion that fractures upon input of an impact load exceeding a specified value.

2. The vehicle front structure according to claim 1, wherein the fracture-inducing portion is provided in the upper load-transmission portion, and the upper load-transmission portion is formed in a shape in which the vertical width gradually increases from the front of the vehicle to the rear of the vehicle when viewed from the side.

3. The vehicle front structure according to claim 1, characterized in that a plurality of fracture-inducing portions are provided on either the upper load-transmission portion or the lower load-transmission portion, spaced apart in the longitudinal direction of the vehicle, and each fracture-inducing portion extends substantially along the vertical direction of the vehicle.

4. The vehicle front structure according to claim 3, characterized in that either the upper load transmission section or the lower load transmission section has a vertical wall section formed by a horizontal cross-section that is bent in a corrugated shape, and each peak of the corrugated bend of the vertical wall section constitutes the fracture induction section.

5. The vehicle front structure according to claim 4, characterized in that the vertical wall portion is provided with inclined ribs that slope downward from the front of the vehicle toward the rear.

6. The vehicle front structure according to claim 5, characterized in that the protruding height of the inclined rib is set higher than the height of the wave-shaped bend of the vertical wall portion in the vehicle width direction.

7. The front vehicle structure according to claim 2, characterized in that the rear of the upper load transmission unit is connected to the front pillar, which is a front member of the passenger compartment, and the rear of the lower load transmission unit is connected to the dashboard panel, which is a front member of the passenger compartment.

8. The front vehicle structure according to claim 1, wherein the damper housing comprises an upper wall having the damper connecting portion and a covering wall extending downward from the edge of the upper wall, the inner surface of the covering wall is provided with an inner reinforcing rib that slopes downward from the front to the rear of the vehicle, and the lower load transmission portion is provided with a load transmission portion side reinforcing rib whose front end is connected to the rear end of the inner reinforcing rib with the covering wall in between, and which slopes downward from the front end toward the rear of the vehicle.

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