JP7419921B2 - Vehicle front suspension device - Google Patents

Description

The present invention relates to a front suspension device for a vehicle.

As one type of offset frontal collision test, a small overlap collision test (small overlap test) in which the offset rate is about 25% is known. This crash test was conducted and published by the Insurance Institute for Highway Safety (IIHS) in the United States at the end of 2012, and was conducted with a barrier covering 25% of the front driver's side of the car at a speed of 40 mph (approximately 64 km). It is something that causes a collision. In order to increase resistance to this type of collision, a suspension member, a side member extending from the suspension member toward the front in the longitudinal direction of the vehicle and provided with a curved portion, and a fastening at the front end of the side member on the vehicle body side. A vehicle front structure has been proposed that includes a bending starting point part that is formed at the rear of the front end part and buckles the front end part upward in the vertical direction of the vehicle (Patent Document 1).

Japanese Patent Application Publication No. 2018-122766

However, in the case of an offset frontal collision, the above conventional technology generates a lateral force on the vehicle by bringing the buckled portion of the side member provided in front of the suspension member into contact with the drive train, and causes the vehicle to avoid the collision object. It is meant to be moved. Therefore, there is no mention of the ability of the suspension member itself to absorb collision energy, and there is room for improvement.

Incidentally, a lower crash box 30 extending in the longitudinal direction of the vehicle is provided at the front end portion 22A of the side member 22 of the prior art (Patent Document 1). A connecting member 32 is provided which curves forward. However, when the front part of the vehicle hits the barrier in an offset frontal collision, the connecting member 32 spanning the pair of left and right lower crash boxes 30 breaks as shown in FIG. 5 of the prior art (Patent Document 1). It does not control the load path function to the side member 22. Therefore, the connecting member 32 of the prior art is not a member that exhibits an energy absorption function in an offset frontal collision including a small overlap.

The problem to be solved by the present invention is to provide a front suspension device for a vehicle that can absorb the energy of an offset frontal collision.

The present invention provides a front suspension member having a pair of side rails extending in the longitudinal direction of a vehicle on each side, and a front suspension member that is attached to extend across the front ends of the pair of side rails. In a front suspension device for a vehicle equipped with a cross member, the center portion of the front cross member is included in the range of the attachment portion between the front cross member and the front end portions of the pair of side rail portions when viewed from the side of the vehicle. The above problem is solved by creating a shape that allows

According to the present invention, when an offset frontal collision occurs, the collision load due to the barrier is input to the front cross member, but since the center part of the front cross member is shaped to be included in the range of the mounting part, The collision load can be directly transmitted to the front suspension member. As a result, the energy of an offset frontal collision can also be absorbed by the front suspension member.

FIG. 1 is a perspective view showing the front portion of an automobile body to which the vehicle front suspension device of the present invention is applied. FIG. 2 is a side view showing the front portion of the automobile body of FIG. 1; FIG. 2 is a plan view showing the front portion of the automobile body of FIG. 1; 1 is a perspective view showing an embodiment of a vehicle front suspension device of the present invention. FIG. 5 is a perspective view of the vehicle front suspension device of FIG. 4 viewed from the back side. FIG. 5 is a front view (A), a plan view (B), a side view (C), and a sectional view taken along the line DD. FIG. 7 is a perspective view showing the front cross member of FIGS. 4 to 6. FIG. 8 is an exploded perspective view showing the front cross member of FIG. 7. FIG. 8 is a sectional view taken along line IX-IX in FIG. 7. FIG. 8 is a cross-sectional view taken along the line XX in FIG. 7. FIG. It is a graph showing the reaction force when an offset frontal collision test is performed on the automobile body according to the example of the present invention. It is a graph showing the reaction force when an offset frontal collision test is performed on an automobile body according to a comparative example of the present invention. FIG. 2 is a plan view and a side view (part 1) showing the front portion of the automobile body when an offset frontal collision test is performed. FIG. 6 is a plan view and a side view (part 2) showing the front portion of the automobile body when an offset frontal collision test is performed. FIG. 7 is a plan view and a side view (part 3) showing the front portion of the automobile body when an offset frontal collision test is performed. FIG. 6 is a plan view and a side view (part 4) showing the front portion of the automobile body when an offset frontal collision test is performed.

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a perspective view showing the front portion of an automobile body 1 to which a vehicle front suspension device 5 of the present invention is applied, FIG. 2 is a side view, and FIG. 3 is a plan view. In addition, in the following explanation, terms indicating directions or positional relationships such as "front", "rear", "left", and "right" are assumed to be directions or positional relationships according to the front, rear, left, and right in the normal attitude of the vehicle. , as shown in FIGS. 2 and 3, the front-rear direction of the vehicle is also referred to as the X-axis, the left-right direction of the vehicle as the Y-axis, and the vertical direction of the vehicle as the Z-axis.

The automobile body 1 of a passenger car is generally assembled and fixed by welding or the like using a floor subassembly, left and right side body subassemblies, a roof subassembly, a front deck subassembly, and a rear panel subassembly. It is then constructed by assembling lid parts such as the hood, side doors, and trunk lid.

The engine room 11 (also referred to as an engine compartment) is an outdoor space having a substantially rectangular parallelepiped shape in which various parts (all not shown) such as an engine, its auxiliary equipment, a drive train, and a battery are mounted. The engine room 11 and the interior (cabin) 12 are partitioned by a dash panel 13, and a pair of left and right front side members 14 extending toward the front of the vehicle are welded by spot welding or arc welding on the front of the dash panel 13. It is fixed by etc. Further, in the range from the rear end to the front end of the pair of left and right front side members 14, a pair of left and right front inside panels 15 constituting a tire house in which the left and right front wheels are housed are welded by spot welding, arc welding, etc. Fixed by

Further, a radiator core support 16 is fixed to the front end of the front side member 14 and the front inside panel 15 by spot welding, arc welding, or the like. The dash panel 13, the pair of left and right front side members 14, the pair of left and right front inside panels 15, and the radiator core support 16 constitute the main frame components of the engine room 11. The front side member 14 supports a heavy engine and its auxiliary equipment, and further supports a front suspension member 51 for supporting a front suspension system (not shown).

FIG. 4 is a perspective view showing an embodiment of the vehicle front suspension device 5 of the present invention, FIG. 5 is a perspective view of this vehicle front suspension device 5 seen from the back side, and FIG. 6 is a perspective view of this vehicle front suspension device 5. FIG. 1 is an (A) front view, (B) a plan view, (C) a side view, and (D) a sectional view taken along the line DD, showing the suspension device 5. FIG. The vehicle front suspension device 5 of this embodiment mainly includes a front suspension member 51, a front cross member 52, and a joint reinforcement 55.

As shown in FIG. 6(D), the front suspension member 51 is a steel component in which two parts 511a and 511b having a U-shaped cross section are press-formed from steel plates, and the joints are joined by arc welding or the like. The general cross section is a bag structure. The front suspension member 51 of this embodiment includes a pair of side rail portions 511 extending in the longitudinal direction of the vehicle on each side, a front cross portion 512 spanning these pair of side rail portions 511, and a center cross portion. It is a rigid structure having a section 513 and a rear cross section 514.

The front suspension member 51 includes mount portions 515 provided on the front upper surfaces of the pair of side rail portions 511, and mount portions 516 provided on the rear upper surfaces of the pair of side rail portions 511. , are attached to the lower surface of the front side member 14 via brackets 517 provided at the rear ends of the pair of side rail portions 511, respectively (see FIG. 2). Note that the reference numeral 56 shown in FIG. 4 is a mount bracket for attaching a lower arm (not shown) of the front suspension system, and the reference numeral 57 is a mount bracket for attaching a drive train (not shown).

Returning to FIG. 2, in addition to the radiator core support 16, a front bumper reinforcement upper 17 is attached to the front end of the front side member 14. Further, a crash box 20 is provided between the front bumper reinforcement upper 17 and the front end of the front side member 14 via a gusset 19. The crash box 20 is a member that absorbs collision energy by compressing and deforming in the axial direction when a collision load is input. are provided in each of the spaces. Further, as shown in FIG. 2, a crash box 58 having a similar function is also provided between the left and right ends of the front cross member 52 and the front bumper reinforcement lower 18, which will be described later.

Now, in the small overlap collision test (SOL) where the offset rate is about 25%, the overlap rate between the barrier and the body is small, so it is difficult to check whether the main frame members such as the front side members 14 and front suspension members 51 will collide with the barrier. Or even if there is a collision, it is difficult to create a sufficient load path. Therefore, there is a problem in that the amount of cabin deformation is larger than in other crash tests in which the wrap rate is large. Therefore, in this embodiment, a front cross member 52 is provided at the front of the front suspension member 51 to ensure that a sufficient collision load is input to the front suspension member 51 even in a minute lap collision with an offset rate of about 25%. It was configured as follows.

Reference numeral B in the plan view of FIG. 3 indicates a barrier for the micro-wrap collision test with an offset rate of 25%, and reference number R1 in the plan view of FIG. This figure shows a first range that extends by 25% of the vehicle width on both the left and right sides. The outside of this first range R1 is the range that collides with the barrier B in the micro-wrap collision test with an offset rate of 25%, but in the automobile body 1 of this embodiment, the front side member 14 also Since all of the side rail portions 511 are within the first range R1, the collision load due to the barrier B is not directly input.

Therefore, in this embodiment, both ends of the front cross member 52 extend outward in the vehicle width direction, and are attached to the front end of the front suspension member 51 at the attachment portion 53 outside the first range R1. As a result, the barrier B collides with the front cross member 52, so that the front suspension member 51 can be used as a road path during a small lap collision via the front cross member 52. The front cross member 52 will be explained below.

7 is a perspective view and a partially enlarged perspective view showing the front cross member 52 in FIGS. 4 to 6, FIG. 8 is an exploded perspective view showing the front cross member 52 in FIG. 7, and FIG. 9 is a perspective view showing the front cross member 52 in FIG. 10 is a sectional view taken along line IX-IX, and FIG. 10 is a sectional view taken along line XX in FIG. 7. As shown in FIG. 9, the front cross member 52 of this embodiment has two parts, which are also press-molded with a U-shaped cross section, at both ends of a front cross member center 521, which is press-molded with a U-shaped cross section. The front cross member sides 522 are overlapped and these parts are joined by spot welding or the like. Although not particularly limited, it is preferable that the front cross member center 521 is made of a steel plate that has a larger amount of deformation (elongation) when a tensile force is applied than the front cross member side 522. This is to prevent the front cross member center 521 from breaking in the event of a collision.

The end of the front cross member side on the outside of the vehicle is a part that becomes the attachment part 53 to the front suspension member 51, and as shown in the exploded perspective view of FIG. 8, the front suspension reinforcement upper 523 and the front suspension reinforcement This is a section with a bag-shaped cross section, in which the lower part 524 is joined together in a monadic shape, and the bulkhead 525 is attached inside. A plate 526 is interposed between the front suspension member 51 and the joint reinforcement 55 attached to the front end surface of the side rail portion 511. These front suspension reinforcement upper 523, front suspension reinforcement lower 524, bulkhead 525, and plate 526 are all press-molded products of steel plates.

The joint reinforcement 55 is a member that connects the end of the front cross member 52 and the front end of the side rail portion 511 of the front suspension member 51, as shown in FIGS. 4 and 6(B), and is shown in FIG. As shown, the cross section is press-molded into a U-shape. As shown in the plan view of FIG. 6(B), the outer surface 52F of the end of the front cross member 52 and the outer surface 55F of the joint reinforcement 55 extend in the extending direction M of the front end of the side rail portion 511. are connected flush along the

Further, as shown in the cross-sectional view of FIG. 10, with respect to the bag structure cross section of the side rail portion 511 of the front suspension member 51, the front suspension reinforcement upper 523, the front suspension reinforcement lower 524, and the bulkhead 525 shown by dotted lines are Since the bag structure cross sections overlap and the U-shaped cross sections of the joint reinforcement 55 also overlap, the collision load input to the front cross member 52 can be transmitted to the side rail portion 511 of the front suspension member 51.

As shown in FIG. 4, the front cross member 52 is attached so as to extend across the front end portions of the pair of side rail portions 511, but the center portion 54 of the front cross member 52 is attached to the side surface of the vehicle. When viewed from above, the shape is included in the second range R2 of the attachment portion 53 between the front cross member 52 and the front end portions of the pair of side rail portions 511. This second range R2 is between the front end surface of the front cross member side 522, which is the front end surface of the mounting portion 53, and the plate 526, which is the rearmost end surface of the mounting portion 53 (see the enlarged view in FIG. 7). .

Furthermore, when viewed from the side of the vehicle, the front end surface of the center portion 54 of the front cross member 52 is lower than the front end surface of the attachment portion 53 between the front cross member 52 and the front end portions of the pair of side rail portions 511. It is said to have a concave shape at the back. Note that the front end surface of the central portion 54 of the front cross member 52 is flush with the front end surface of the attachment portion 53 between the front cross member 52 and the front end portions of the pair of side rail portions 511 when viewed from the side of the vehicle. It may be in the shape of However, it is not preferable that the front end surface of the central portion 54 of the front cross member 52 be shaped to be more convex toward the front of the vehicle than the front end surface of the attachment portion 53 beyond the second range R2. This is because the front cross member 52 is likely to break during a collision.

Further, the front end surface of the front cross member 52 is located at the rear of the vehicle than the front end surface of the front bumper reinforcement upper 17 and further forward of the vehicle than the front end of the front side member 14 when viewed from the side of the vehicle. It is installed so that it is located in the section. The left diagram in FIG. 11 is a schematic diagram of the front bumper reinforcement upper 17, the front side member 14, the front cross member 52, and the side rail portion 511 of the front suspension member 51 when the automobile body 1 is viewed from the side. It is. Symbol P indicates the planned buckling position. As shown in the left diagram of FIG. 11, the front end surface of the front cross member 52 is attached between the front end surface of the front bumper reinforcement upper 17 and the front end portion of the front side member 14.

The right diagram in FIG. 11 shows the reaction force F1 of the front cross member 52 and side rail portion 511 at the time of collision, the reaction force F2 of the front side member 14 at the time of collision, their resultant force F3, and the reaction force of the interior (cabin) 2. This is a graph showing F4 (the horizontal axis is time). When the settings are as shown in the left diagram of FIG. 11, when a collision load is input, the peak of the reaction force F1 caused by the front cross member 52 and the side rail portion 511 appears first, and then, after a short delay, the front side member 14 A peak of reaction force F2 appears at the time of collision. Therefore, the efficiency of the impact absorption energy, which is the resultant force F3, becomes high, and each member buckles at the initially planned buckling position P.

On the other hand, FIG. 12 is a schematic diagram and a graph showing a comparative example of this embodiment. As shown in the left diagram of FIG. 11, in the comparative example, the front end surface of the front cross member 52 is behind the front end surface of the front bumper reinforcement upper 17, but is the same as the front end surface of the front side member 14. mounted in position. With this setting, when a collision load is input, the peak of the reaction force F1 caused by the front cross member 52 and side rail section 511 at the time of a collision, and the peak of the reaction force F2 at the time of a collision of the front side member 14 appear simultaneously. , there is a risk that the front suspension member 51 may buckle at a position P1 that is not the planned buckling position P.

13 to 16 are a plan view and a side view showing the front portion of the automobile body 1 when an offset frontal crash test is conducted. FIG. 13 shows the state when the collision load from barrier B is input to the front bumper reinforcement upper 17 at the initial stage of the collision, and FIG. 14 shows the state when the collision load from barrier B is input to the front cross member 52 at the next point in time. FIG. 15 shows the state when the collision load from barrier B is input to the front suspension member 51 at the next time point, and FIG. 16 shows the state at the next time point. In the state shown in FIG. 14, the collision load from the barrier B is input to the mounting portion 53 of the front cross member 52, and this collision load is transmitted to the side rail portion 511 of the front suspension member 51 via the joint reinforcement 55. It is understood that this causes the side rail portion 511 to buckle, as shown in FIGS. 15 and 16.

As described above, according to the vehicle front suspension device 5 of the present embodiment, the front suspension member 51 is attached to the front side member 14 and supports the suspension device, and the front suspension member 51 is attached to the front end of the front suspension member 51. The front suspension member 51 has a pair of side rail portions 511 extending in the longitudinal direction of the vehicle on each side, and the front cross member 52 has a pair of side rail portions 511 extending in the longitudinal direction of the vehicle. The center portion 54 of the front cross member 52 is attached to extend across the front end portions, and the center portion 54 of the front cross member 52 is attached to the front end portions of the front cross member 52 and the pair of side rail portions 511 when the automobile body 1 is viewed from the side. The shape is included in the second range R2 of the attachment portion 53. Thereby, the collision load can be transmitted to the front suspension member 51 without causing the front cross member 52 to break due to the collision load. As a result, the energy of an offset frontal collision can also be absorbed by the front suspension member.

Further, according to the vehicle front suspension device 5 of the present embodiment, the front end surface of the central portion 54 of the front cross member 52 is connected to the front cross member 52 and the pair of side rails when the automobile body 1 is viewed from the side. The front end surface of the attachment part 53 with the front end of the part 511 is recessed toward the rear of the vehicle. Thereby, the collision load can be transmitted to the front suspension member 51 without causing the front cross member 52 to break due to the collision load. As a result, the energy of an offset frontal collision can also be absorbed by the front suspension member.

Further, according to the vehicle front suspension device 5 of the present embodiment, the front end surface of the central portion 54 of the front cross member 52 is connected to the front cross member 52 and the pair of side rails when the automobile body 1 is viewed from the side. The front end of the portion 511 and the front end surface of the attachment portion 53 are flush with each other. Thereby, the collision load can be transmitted to the front suspension member 51 without causing the front cross member 52 to break due to the collision load. As a result, the energy of an offset frontal collision can also be absorbed by the front suspension member.

Further, according to the vehicle front suspension device 5 of the present embodiment, the front end surface of the front cross member 52 is located at the front bumper reinforcement upper 17 or the front bumper reinforcement lower when the automobile body 1 is viewed from the side. The front side member 18 is attached so as to be located at the rear of the vehicle than the front end surface of the front side member 18 and at the front of the vehicle than the front end of the front side member 14 . As a result, when a collision load is input, as shown in FIG. 11, the peak of the reaction force F1 caused by the front cross member 52 and the side rail portion 511 appears first, and then the front side member 14 collides a little later. The peak of the reaction force F2 appears. Therefore, the efficiency of the shock absorption energy, which is the resultant force F3, becomes high, and each member buckles at the initially planned buckling position P.

Further, according to the vehicle front suspension device 5 of the present embodiment, the attachment portion 53 between the front cross member 52 and the front end portions of the pair of side rail portions 511 is provided with a As shown in FIG. 6(B), the outer surface 52F of the end of the front cross member 52 and the outer surface 55F of the joint reinforcement 55 are connected to the front end of the side rail. The front end of the portion 511 is connected flush with the extending direction M. Thereby, the collision load input to the mounting portion 53 of the front cross member 52 can be efficiently transmitted to the side rail portion 511 of the front suspension member 51.

Further, according to the vehicle front suspension device 5 of the present embodiment, the end portion of the front cross member 52 has a bag structure in cross section, and the bulkhead 525 is located between the top and bottom surfaces of the inside of the bag structure. Fixed. As a result, the strength of the attachment portion 53 of the front cross member 52 is increased, and the collision load input to the attachment portion 53 of the front cross member 52 can be efficiently transmitted to the side rail portion 511 of the front suspension member 51.

Further, according to the vehicle front suspension device 5 of the present embodiment, the pair of side rail portions 511 are attached to the first range R1 extending from the center line CL in the vehicle width direction by a length of 25% of the vehicle width on each side. , both ends of the front cross member 52 are mounted outside the first range R1. As a result, even in a small lap collision with an offset rate of 25%, the collision load will be input to the front cross member 52, so the front suspension member 51 will be loaded via the front cross member 52 to the load at the time of a small lap collision. It can be a pass.

Further, according to the vehicle front suspension device 5 of the present embodiment, the front suspension member 51 includes a rear cross portion 514 spanning the rear end portions of the pair of side rail portions 511 and a center portion of the pair of side rail portions 511. a center cross section 513 that spans over the front cross member 52; is attached to the front side member 14. Thereby, the front suspension member 51 can be used as a load path during a small lap collision.

Further, according to the vehicle front suspension device 5 of the present embodiment, there is a gap between the front end surface of the attachment portion 53 of the front cross member 52 and the front end portions of the pair of side rail portions 511 and the front bumper reinforcement lower 18. A crash box 58 is provided. Thereby, when a collision load is input to the front bumper reinforcement lower 18, the crash box 58 is compressively deformed in the axial direction, thereby absorbing the collision energy.

1...Car body 11...Engine room 12...Interior 13...Dash panel 14...Front side member 15...Front inside panel 16...Radiator core support 17...Front bumper reinforcement upper 18...Front bumper reinforcement lower 19...Gusset 20...Crash Box 5...Front suspension device for vehicle 51...Front suspension member 511...Side rail part 512...Front cross part 513...Center cross part 514...Rear cross part 515, 516...Mount part 517...Bracket 52...Front cross member 521...Front cross Member center 522...Front cross member side 523...Front suspension reinforcement upper 524...Front suspension reinforcement lower 525...Bulkhead 526...Plate 53...Attachment part between the front cross member and the tip of the side rail portion 54...Front cross member Central part 55...Joint reinforcement 56, 57...Mount bracket 58...Crash box B...Barrier (barrier)
CL...Central line in the vehicle width direction R1...First range R2...Second range

Claims (8)

a front suspension member that is attached to at least a front side member of an engine compartment of an automobile body and supports a suspension device;
A front suspension device for a vehicle, comprising: a front cross member attached to a front end of the front suspension member;
The front suspension member has a pair of side rail portions extending in the longitudinal direction of the vehicle on each of both side portions,
The front cross member is attached to extend so as to bridge the front end portions of the pair of side rail portions,
The central portion of the front cross member has a shape that is included in the range of the attachment portion between the front cross member and the front end portions of the pair of side rail portions when the automobile body is viewed from the side ,
A joint reinforcement is provided at a mounting portion between the front cross member and the front end portions of the pair of side rail portions to connect the end portion of the front cross member and the front end portion of the side rail portion,
In the vehicle front suspension device, an outer surface of an end of the front cross member and an outer surface of the joint reinforcement are connected flush with each other along an extending direction of a front end of the side rail portion . a front suspension member that is attached to at least a front side member of an engine room of an automobile body and supports a suspension device;
A front suspension device for a vehicle, comprising: a front cross member attached to a front end of the front suspension member;
The front suspension member has a pair of side rail portions extending in the longitudinal direction of the vehicle on each of both side portions,
The front cross member is attached to extend so as to bridge the front end portions of the pair of side rail portions,
The central portion of the front cross member has a shape that is included in the range of the attachment portion between the front cross member and the front end portions of the pair of side rail portions when the automobile body is viewed from the side ,
The front suspension member includes a front cross portion that is a front end portion of the pair of side rail portions and extends rearward from the front cross member,
A front suspension device for a vehicle , wherein the pair of side rail portions are attached to the front side member . The front end surface of the central portion of the front cross member is located at the rear of the vehicle from the front end surface of the attachment portion between the front cross member and the front ends of the pair of side rails when the automobile body is viewed from the side. The front suspension device for a vehicle according to claim 1 or 2, wherein the front suspension device has a shape concave to the side. The front end surface of the central portion of the front cross member is flush with the front end surface of the attachment portion of the front cross member and the front end portions of the pair of side rail portions, when the automobile body is viewed from the side. The vehicle front suspension device according to claim 1 or 2, wherein the vehicle front suspension device has a shape. The frontmost end surface of the front cross member is located at the rear of the vehicle relative to the frontmost end surface of the front bumper reinforcement and further forward of the vehicle than the front end of the front side member when the automobile body is viewed from the side. The front suspension device for a vehicle according to any one of claims 1 to 4 , wherein the vehicle front suspension device is installed so as to be located at the front suspension device. 6. The end portion of the front cross member has a bag structure in cross section, and a bulkhead is fixed between an upper surface and a lower surface inside the bag structure. Front suspension device for vehicles. The pair of side rail portions are attached to a first range extending from the center line in the vehicle width direction by a length of 25% of the vehicle width on each side,
7. The front suspension device for a vehicle according to claim 1, wherein both ends of the front cross member are mounted outside the first range. Any one of claims 1 to 7 , wherein a crash box is provided between the front end surface of the attachment portion of the front cross member to the front end portions of the pair of side rail portions and the front bumper reinforcement lower. A front suspension device for a vehicle as described in 2.