Vehicle front structure

Abstract

A vehicle front structure S comprises a pair of side members (11L, 11R), a pair of strut towers (21L, 21R), a pair of suspension arm support parts (32L, 32R), a lower cross member 41, a pair of upper brackets (52L, 52R), and a pair of lower brackets (42L, 42R). The pair of side members (11L, 11R) extend in the front-back direction of a vehicle. The pair of strut towers (21L, 21R) are respectively joined to the pair of side members (11L, 11R). The pair of suspension arm support parts (32L, 32R) respectively support suspension arms (31L, 31R) and are respectively fixed to the pair of side members (11L, 11R). The lower cross member 41 is joined to the pair of suspension arm support parts (32L, 32R). The pair of upper brackets (52L, 52R) respectively attach a power train 61, which has at least an engine or a driving motor 62, to the pair of side members (11L, 11R) or to the pair of strut towers (21L, 21R). The pair of lower brackets (42L, 42R) attach the power train 61 to the lower cross member 41.

Description

Vehicle front structure

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

[0002] Patent document 1 discloses a motor unit support device that mounts and supports a motor unit on a cross member, and has a configuration that has an axial fastening member whose axial direction coincides with the fore-and-aft direction of the vehicle in order to ensure mounting rigidity in the fore-and-aft direction of the vehicle.

[0003] JP 2018-114785 A

[0004] However, the motor unit support device of Patent Document 1 has an increased number of parts and a complex structure. When a powertrain including a motor is mounted in the front of a vehicle, a simpler structure for supporting the powertrain is often required. On the other hand, it is necessary to improve the mounting rigidity in the fore-and-aft direction of the vehicle.

[0005] An object of the present invention is to provide a vehicle front structure for supporting a powertrain that can improve mounting rigidity in the vehicle longitudinal direction with a simple configuration.

[0006] A vehicle front structure according to one aspect of the present invention includes a pair of side members, a pair of strut towers, a pair of suspension arm support portions, a lower cross member, a pair of upper brackets, and a pair of lower brackets. The pair of side members are provided at the front of the vehicle and extend in the fore-and-aft direction of the vehicle. The pair of strut towers are provided above the pair of side members and are respectively connected to the pair of side members. The pair of suspension arm support portions are provided below the pair of side members, each support a suspension arm, and are respectively fixed to the pair of side members. The lower cross member is provided between the pair of suspension arm support portions and is connected to the pair of suspension arm support portions. The pair of upper brackets mount a powertrain having at least an engine or a drive motor to the pair of side members or the pair of strut towers, respectively. The pair of lower brackets mount the powertrain to the lower cross member.

[0007] According to the above vehicle front structure, it is possible to provide a vehicle front structure for supporting a powertrain that has a simple configuration and can improve mounting rigidity in the vehicle longitudinal direction.

[0008] Fig. 1 is a perspective view showing a vehicle front structure according to an embodiment. Fig. 2 is a side view showing the vehicle front structure according to an embodiment, illustrating the structures of an upper bracket and a lower bracket on the right side of the vehicle front structure. Fig. 3 is a perspective view showing the structures of a lower cross member and a lower bracket. Fig. 4 is a perspective view showing the structures of a suspension arm and a suspension arm support portion. Fig. 5 is a perspective view showing the structure when an upper cross member is attached to the vehicle front structure according to an embodiment.

[0009] A vehicle front structure S mounted on a vehicle according to an embodiment will be described below with reference to the drawings. In each drawing, FW indicates the front in the vehicle longitudinal direction, UP indicates the upper side in the vehicle vertical direction, and LH and RH indicate the left and right sides in the vehicle width direction, respectively. In the following description, the front, front side, rear side, and rear side in the vehicle longitudinal direction, the upper side, upper side, lower side, and lower side in the vehicle vertical direction, and the left side, left side, right side, and right side in the vehicle width direction will be simply referred to as the front, front side, rear side, rear side, upper side, upper side, lower side, lower side, left side, left side, right, and right side, respectively. Furthermore, components having the same functions as those already described will be designated by the same reference numerals, and description thereof will be omitted.

[0010] The vehicle front structure S includes a pair of side members 11L, 11R, a pair of strut towers 21L, 21R, a pair of suspension arm supports 32L, 32R, and a lower cross member 41 (see FIG. 1). The vehicle front structure S also includes a power train 61 having at least an engine or a drive motor 62. An upper portion of the power train 61 is attached to the pair of side members 11L, 11R or the pair of strut towers 21L, 21R via a pair of upper brackets 52L, 52R. A lower portion of the power train 61 is attached to the lower cross member 41 via a pair of lower brackets 42L, 42R (see FIG. 1).

[0011] The pair of side members 11L, 11R are skeletal structural members disposed on the left and right sides of the vehicle. The pair of side members 11L, 11R extend in the longitudinal direction of the vehicle. Support brackets 13L, 13R are joined to the front portions of the pair of side members 11L, 11R, and connect to the lower suspension arm support portions 32L, 32R. Support arms 14L, 14R are joined to the rear portions of the pair of side members 11L, 11R, and connect to the lower suspension arm support portions 32L, 32R (see FIGS. 1 and 2).

[0012] A pair of strut towers 21L, 21R are provided above the pair of side members 11L, 11R (see FIG. 1 ). A powertrain 61, which includes at least an engine or a drive motor for propelling the vehicle, is disposed between the left strut tower 21L and the right strut tower 21R. In the configuration illustrated in FIG. 1 , the powertrain 61 includes a drive motor 62, an inverter 63, which is a power conversion component, disposed rearward of the drive motor 62, and a differential 64 disposed below the drive motor 62. Note that the components constituting the powertrain 61 and their arrangement are not limited to those described above.

[0013] Upper fixed shafts 65L, 65R are provided on the upper portion of the powertrain 61, extending outward in the vehicle width direction from the left and right ends of the powertrain 61. The left and right upper fixed shafts 65L, 65R are supported by being inserted into upper brackets 52L, 52R, respectively, and are fixed to the side members 11L, 11R or the strut towers 21L, 21R. In the configuration illustrated in FIG. 1 , the upper brackets 52L, 52R are fixed to the side members 11L, 11R and the strut towers 21L, 21R, respectively.

[0014] The upper bracket 52R may have two front and rear upper legs 53RU and two front and rear lower legs 53RD provided at the right end (see FIGS. 1 and 2). The upper legs 53RU are fastened to the right side surface of the strut tower 21R with bolts. Meanwhile, the lower legs 53RD are fastened to the right side surface of the right side member 11R extending in the vehicle longitudinal direction with bolts. The front fastening point of the upper legs 53RU with the bolts is the upper attachment point P1R1 of the upper bracket 52R, and the rear fastening point of the upper legs 53RU with the bolts is the upper attachment point P1R2. The front fastening point of the lower legs 53RD with the bolts is the lower attachment point P2R1 of the upper bracket 52R, and the rear fastening point of the lower legs 53RD with the bolts is the lower attachment point P2R2. The left upper bracket 52L has the same configuration as the right upper bracket 52R, and therefore its description will be omitted. The upper portion of the powertrain 61 is fastened to the upper brackets 52L and 52R in a direction parallel to the vehicle width direction by upper fixed shafts 65L and 65R, respectively (see FIGS. 1 and 2).

[0015] The upper portions of the strut towers 21L, 21R are provided with fixing points 23L, 23R to which suspension struts are fixed. The upper brackets 52L, 52R may be provided on the side surfaces of the strut towers 21L, 21R in positions that overlap with the fixing points 23L, 23R to which the suspension struts on the strut towers 21L, 21R are fixed in the vehicle longitudinal direction (see FIG. 2). More specifically, the fixing point 23L to which the left suspension strut is fixed may be located between the upper attachment points P1L1, P1L2, which are the two front and rear fastening points of the upper bracket 52L, in the vehicle longitudinal direction. Furthermore, the fixing point 23L to which the left suspension strut is fixed may be located between the lower attachment points P2L1, P2L2 in the vehicle longitudinal direction (see FIG. 2). The positional relationship between the fixed point 23R to which the strut of the right suspension is fixed and the upper bracket 52R may be the same as the positional relationship between the fixed point 23L to which the strut of the left suspension is fixed and the upper bracket 52L, so explanation will be omitted.

[0016] The left suspension arm 31L has a V-shape and supports a wheel (not shown). The suspension arm 31L is connected to the strut tower 21L. A suspension strut is disposed at the tip of the V-shape of the suspension arm 31L. The suspension arm 31L is fixed to the lower cross member 41 via a suspension arm support portion 32L (see FIG. 3).

[0017] The suspension arm support portions 32L, 32R are respectively connected to the front and rear ends of the left and right ends of the lower cross member 41. A V-shaped suspension arm 31L is connected to each of the front and rear suspension arm support portions 32L. The suspension arm support portion 32L is fixed to the upper side member 11L via a support bracket 13L and a support arm 14L. The configuration of the right suspension arm 31R is similar to that of the left suspension arm 31L, so a description thereof will be omitted.

[0018] A lower cross member 41 is disposed below the pair of side members 11L, 11R. The lower cross member 41 is a framework structural member that extends in the front-rear direction and the vehicle width direction (see FIGS. 1 and 2). The lower cross member 41 is also referred to as a suspension member.

[0019] The lower cross member 41 is provided between the suspension arm support portions 32L and 32R and is made up of side beams 41L and 41R, a rear cross beam 41B, and a front cross beam 41F (see FIG. 3).

[0020] The side beams 41L, 41R extend forward from both ends of the rear cross beam 41B at an upward incline. The front ends of the side beams 41L, 41R are connected by a front cross beam 41F that extends in the vehicle width direction (see FIG. 3).

[0021] The lower portion of the powertrain 61 is supported by left and right lower brackets 42L, 42R, respectively, and fixed to the lower cross member 41 (see FIG. 1-4). More specifically, lower fixed shafts 66L, 66R are provided at the left and right ends of the lower portion of the powertrain 61, respectively, and extend outward in the vehicle width direction from those ends. The left and right lower fixed shafts 66L, 66R are supported by being inserted into the lower brackets 42L, 42R, respectively, and fixed to the lower cross member 41. The lower portion of the powertrain 61 is fastened to the lower brackets 42L, 42R by the lower fixed shafts 66L, 66R in a direction parallel to the vehicle width direction (see FIG. 1-4).

[0022] The left and right lower brackets 42L, 42R each have a through hole H into which the lower fixed shaft 66L, 66R is inserted, a cylindrical bearing portion 43L, 43R extending in the vehicle width direction centered on the through hole H, and a main body portion 44L, 44R that accommodates and fixes the cylindrical outer peripheral surface of the bearing portion 43L, 43R (see Figures 3 and 4).

[0023] The left and right main body portions 44L, 44R each have a front fixing portion 45F extending forward and a rear fixing portion 45B extending rearward and having two fastening points on the left and right (see FIGS. 3 and 4). The left lower bracket 42L is fixed to the left portion of the rear cross beam 41B by fastening the front fixing portion 45F and the rear fixing portion 45B with bolts. The fastening point for the bolt on the front fixing portion 45F is the front fixing point 47F. The fastening point for the bolt on the rear fixing portion 45B is the rear fixing point 47B (see FIG. 4). The structure in which the right lower bracket 42R is fixed to the right portion of the rear cross beam 41B is the same as described above, so a description thereof will be omitted.

[0024] The left and right portions of the rear cross beam 41B of the lower cross member 41 may be provided with holes 46L, 46R extending vertically therethrough (see FIGS. 3 and 4). The holes 46L, 46R are provided at positions corresponding to the lower brackets 42L, 42R, respectively. When the lower brackets 42L, 42R are fastened to the lower cross member 41, the main bodies 44L, 44R and bearings 43L, 43R of the lower brackets 42L, 42R are attached by being partially received in the holes 46L, 46R. That is, when the lower brackets 42L, 42R are fixed to the lower cross member 41, the main bodies 44L, 44R and bearings 43L, 43R are partially received in the holes 46L, 46R, and the lower brackets 42L, 42R are positioned lower in the vertical direction than when the holes 46L, 46R are not provided. Therefore, the positions of the lower fixed shafts 66L, 66R in the vertical direction are positioned lower than when the holes 46L, 46R are not provided. As a result, a predetermined distance can be provided between the pair of upper brackets 52L, 52R and the pair of lower brackets 42L, 42R without moving the positions of the pair of upper brackets 52L, 52R upward in the vehicle vertical direction. This ensures the sound and vibration performance of the powertrain 61.

[0025] The front fixing portion 45F and the rear fixing portion 45B extending from the main body portions 44L, 44R of the lower brackets 42L, 42R may be attached to the lower cross member 41 so as to straddle the hole portions 46L, 46R in the vehicle longitudinal direction (see FIGS. 3 and 4). That is, the front fixing portion 45F and the rear fixing portion 45B are arranged to bridge the hole portions 46L, 46R and are fixed to the lower cross member 41 in front of and behind the hole portions 46L, 46R, respectively. Note that the hole portions 46L, 46R do not have to penetrate the lower cross member 41 in the vertical direction, and may, for example, have a shape recessed downward from the surface of the lower cross member 41.

[0026] The upper brackets 52L, 52R and the lower brackets 42L, 42R may be positioned so as to at least partially overlap in the vehicle longitudinal direction (see FIG. 2). That is, in the vehicle longitudinal direction, either the upper attachment point P1L1, P1L2 or the lower attachment point P2L1, P2L2 of the left upper bracket 52L may be positioned between the front fixing point 47F and the rear fixing point 47B of the left lower bracket 42L. The positional relationship between either the upper attachment point P1R1, P1R2 or the lower attachment point P2R1, P2R2 of the right upper bracket 52R and the front fixing point 47F and the rear fixing point 47B of the right lower bracket 42R may be similar to the above. Furthermore, the lower brackets 42L, 42R may be positioned rearward of the output shaft 62A of the drive motor 62. That is, in the vehicle longitudinal direction, the through holes H in the lower brackets 42L, 42R, into which the lower fixed shafts 66L, 66R are inserted, may be located rearward of the output shaft 62A of the drive motor 62. Because the powertrain 61 according to this embodiment has the inverter 63 on the rear side, the center of gravity of the powertrain 61 is located rearward of the drive motor 62. With this arrangement, the lower brackets 42L, 42R can stably support the above structure at a position closer to the center of gravity.

[0027] The upper cross member 71 may be disposed above the powertrain 61 between the strut towers 21L and 21R (see FIG. 5). The upper cross member 71 is connected to the strut towers 21L and 21R and has a mounting surface 71A between the strut towers 21L and 21R on which various vehicle components can be placed. The left edge 71L of the upper cross member 71 is fastened to the front and rear sides of the strut tower 21L with bolts. Similarly, the right edge 71R of the upper cross member 71 is fastened to the front and rear sides of the strut tower 21R with bolts.

[0028] (1) The vehicle front structure S includes a pair of side members 11L, 11R, a pair of strut towers 21L, 21R, a pair of suspension arm support portions 32L, 32R, a lower cross member 41, a pair of upper brackets 52L, 52R, and a pair of lower brackets 42L, 42R. The pair of side members 11L, 11R are provided at the front of the vehicle and extend in the fore-and-aft direction of the vehicle. The pair of strut towers 21L, 21R are provided above the pair of side members 11L, 11R and are respectively connected to the pair of side members 11L, 11R. The pair of suspension arm support portions 32L, 32R are provided below the pair of side members 11L, 11R, support the respective suspension arms 31L, 31R, and are respectively fixed to the pair of side members 11L, 11R. The lower cross member 41 is provided between and connected to the pair of suspension arm supports 32L, 32R. The pair of upper brackets 52L, 52R attach a power train 61, which includes at least an engine or a drive motor, to the pair of side members 11L, 11R or the pair of strut towers 21L, 21R, respectively. The pair of lower brackets 42L, 42R attach the power train 61 to the lower cross member 41.

[0029] In the above configuration, by providing the upper brackets 52L, 52R to one or both of the side members 11L, 11R and the strut towers 21L, 21R, which have a relatively high rigidity in the vehicle fore-and-aft direction, and by providing the lower brackets 42L, 42R to the lower cross member 41, which has a relatively high rigidity in the vehicle fore-and-aft direction, it is possible to improve the mounting rigidity of the powertrain 61 in the vehicle fore-and-aft direction. Therefore, there is no need to add new parts or the like to improve the rigidity for mounting the powertrain 61.

[0030] (2) Furthermore, according to the embodiment, the upper portions of the pair of strut towers 21L, 21R have fixing points 23L, 23R to which suspension struts are fixed, and the pair of upper brackets 52L, 52R are provided in positions that overlap with the fixing points 23L, 23R in the vehicle longitudinal direction. By providing the pair of upper brackets 52L, 52R in positions in the vehicle longitudinal direction that correspond to the fixing points 23L, 23R of the strut towers 21L, 21R, which have relatively high rigidity, the mounting rigidity of the powertrain 61 in the vehicle longitudinal direction can be further improved.

[0031] (3) Furthermore, according to the embodiment, the pair of upper brackets 52L, 52R are respectively positioned so as to at least partially overlap the pair of lower brackets 42L, 42R in the vehicle longitudinal direction. This configuration ensures a wide crush area in the vehicle longitudinal direction when a load is input to the vehicle body from the front, thereby enabling the load from the front to be more absorbed. Furthermore, without this configuration, the crush area in the vehicle longitudinal direction may be ensured by increasing the size of the vehicle front structure in the vehicle longitudinal direction. By adopting this configuration, it is possible to avoid increasing the size of the vehicle front structure in the vehicle longitudinal direction.

[0032] (4) According to the embodiment, the powertrain 61 includes a drive motor 62 and an inverter 63, which is a power conversion device, located rearward of the drive motor 62, and the pair of lower brackets 42L, 42R are disposed rearward of the output shaft 62A of the drive motor 62. Because the inverter 63 is located rearward, the center of gravity of the vehicle front structure is shifted rearward of the powertrain 61. This arrangement allows the structure to be stably supported at a position closer to the center of gravity.

[0033] (5) Furthermore, according to the embodiment, the powertrain 61 is fastened in the vehicle width direction to each of the pair of upper brackets 52L, 52R and the pair of lower brackets 42L, 42R. This configuration allows the powertrain 61 to preferably bear loads due to its own weight, road input, and driving reaction force. Furthermore, the loads can be distributed among four locations, reducing the load per location. Therefore, for example, more flexible insulators can be used for the upper brackets 52L, 52R and the lower brackets 42L, 42R, thereby improving noise and vibration performance.

[0034] (6) According to the embodiment, the lower cross member 41 has holes 46L, 46R at positions corresponding to the pair of lower brackets 42L, 42R, respectively. The holes 46L, 46R accommodate at least a portion of the lower brackets 42L, 42R, and the pair of lower brackets 42L, 42R are attached to the lower cross member 41 so as to straddle the holes 46L, 46R. This configuration allows a predetermined distance to be provided between the pair of upper brackets 52L, 52R and the pair of lower brackets 42L, 42R in the vehicle vertical direction without raising the positions of the pair of upper brackets 52L, 52R. This ensures the sound and vibration performance of the powertrain 61. Furthermore, by attaching the pair of lower brackets 42L, 42R to the lower cross member 41 so as to straddle the holes 46L, 46R, a decrease in bracket support rigidity can be prevented.

[0035] The above-described embodiments are merely examples described to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the above-described embodiments, but also includes various modifications, changes, alternative technologies, etc. that can be easily derived therefrom.

[0036] In the above embodiment, the differential 64 is provided directly below the drive motor 62, but the differential 64 may be located in a different position. In this case, by locating the pair of lower brackets 42L, 42R rearward of the output shaft 62A, a space can be provided directly below the output shaft 62A. This makes it easier to design the layout of the front axle.

[0037] 11L, 11R Side member 21L, 21R Strut tower 23L, 23R Fixed point 31L, 31R Suspension arm 32L, 32R Suspension arm support portion 41 Lower cross member 42L, 42R Lower bracket 46L, 46R Hole portion 52L, 52R Upper bracket 61 Power train 62 Drive motor 62A Output shaft 63 Inverter (power conversion device) S vehicle front structure

Claims

1. A vehicle front structure comprising: a pair of side members provided at a front of a vehicle and extending in the fore-and-aft direction of the vehicle; a pair of strut towers provided above the pair of side members and each connected to the pair of side members; a pair of suspension arm support parts provided below the pair of side members, each supporting a suspension arm and each fixed to the pair of side members; a lower cross member provided between the pair of suspension arm support parts and connected to the pair of suspension arm support parts; a pair of upper brackets attaching a powertrain having at least an engine or a drive motor to the pair of side members or the pair of strut towers, respectively; and a pair of lower brackets attaching the powertrain to the lower cross member.

2. A vehicle front structure as described in claim 1, wherein the upper portions of the pair of strut towers each have a fixing point to which a suspension strut is fixed, and the pair of upper brackets are each provided at a position overlapping with the fixing point in the fore-and-aft direction of the vehicle.

3. A vehicle front structure according to claim 1 or 2, wherein the pair of upper brackets are respectively arranged at positions at which they at least partially overlap the pair of lower brackets in the vehicle fore-and-aft direction.

4. The vehicle front structure according to claim 3, wherein the power train has the drive motor and a power conversion device provided rearward of the drive motor, and the pair of lower brackets are disposed rearward of the output shaft of the drive motor.

5. The vehicle front structure according to any one of claims 1 to 4, wherein the power train is fastened in the vehicle width direction to each of the pair of upper brackets and the pair of lower brackets.

6. A vehicle front structure as described in any one of claims 1 to 5, wherein the lower cross member has hole portions at positions corresponding to each of the pair of lower brackets, the hole portions each accommodate at least a portion of the lower bracket, and the pair of lower brackets are attached to the lower cross member so as to straddle the hole portions.

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