Vehicle front structure

Abstract

The vehicle front structure of the present invention comprises: a pair of front side members (11L, 11R) which are arranged on both sides of the front of the vehicle and extend in the vehicle front-rear direction; an engine compartment cross member (20) which is installed between the pair of front side members (11L, 11R); in the vehicle front structure, the engine compartment cross member (20) is an annular member comprising the following members: a pair of side members (21L, 21R) which are respectively installed on the vehicle width direction inner sides of the respective front side members (11L, 11R) and respectively extend in the vehicle front-rear direction; a front cross member (24) which connects the respective front ends of the pair of side members (21L, 21R) in the vehicle width direction; and a rear cross member (27) which connects the respective rear ends of the pair of side members (21L, 21R) in the vehicle width direction, the rear cross member (27) being curved so as to become convex toward the vehicle rear side.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Japanese Patent Application No. 2022-045925 filed on March 22, 2022, the entire contents of which including specification, claims, drawings, and abstract are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a front structure of a vehicle including a front side member and an engine compartment cross member. Background Art

[0004] Traditionally, the engine or hybrid drive unit that drives the vehicle was housed in the engine compartment or front compartment at the front of the vehicle. However, in recent years, vehicles have been using a system where the battery is mounted under the vehicle floor, using the space in front of the vehicle as a cargo area. To improve the frontal collision performance of vehicles with such a cargo area, a structure has been proposed that includes a bow-shaped transverse bar between the front side members and a support bracket connecting the front side members and the transverse bar (see, for example, Japanese Patent Application Laid-Open No. 2021-95114).

[0005] In addition, a structure has been proposed in which, in a vehicle in which a battery and a hydrogen tank are mounted at the rear of the vehicle body, a U-shaped frame projecting toward the rear of the vehicle is installed between the left and right rear side frames in order to improve the impact resistance (for example, refer to Japanese Patent Gazette No. 2010-184574).

[0006] In addition, a structure has been proposed in which a pair of front side members in front of the vehicle are connected using an engine compartment cross beam as an annular structural member, a power control unit is mounted on the upper side of the engine compartment cross beam, and a vehicle driving motor is mounted on the lower side of the engine compartment cross beam (for example, refer to Japanese Patent Gazette No. 2020-37310). Summary of the Invention

[0007] However, electric vehicles increase the weight of the vehicle body due to the increased weight of the battery, which is mounted under the floor. This increases the impact energy during a frontal collision, requiring greater absorption of the collision energy. Furthermore, there is a need to minimize the penetration of obstacles.

[0008] Therefore, an object of the present disclosure is to increase the amount of collision energy absorbed while suppressing the amount of entry of an obstacle during a frontal collision of a vehicle.

[0009] The vehicle front structure disclosed herein includes: a pair of front side members, which are arranged on both sides of the front of the vehicle and extend in the vehicle front-rear direction; an engine compartment cross member, which is installed between the pair of front side members. The vehicle front structure is characterized in that the engine compartment cross member is an annular component including the following components: a pair of side members, which are respectively installed on the vehicle width direction inner sides of each of the front side members and each extend in the vehicle front-rear direction; a front cross member, which connects the front ends of the pair of side members in the vehicle width direction; and a rear cross member, which connects the rear ends of the pair of side members in the vehicle width direction, and the rear cross member is curved so as to convex toward the vehicle rear side.

[0010] In this way, by curving the rear cross member to convexly project toward the vehicle rear, the rigidity of the engine compartment cross member in the vehicle's fore-aft direction is enhanced. This reduces deformation of the engine compartment cross member during a collision, and allows the impact load applied to the engine compartment cross member during a frontal collision to be smoothly transferred to the rear portion of the rear cross member, thereby transmitting the impact load to the stronger portion of the dash panel located behind the rear cross member. This reduces the amount of obstacles that enter the vehicle while increasing the amount of collision energy absorbed.

[0011] In the vehicle front structure disclosed herein, the rear cross member may include a rear center portion extending in the vehicle width direction; and two bent portions bent toward the vehicle front from two end portions of the rear center portion, with respective top ends extending in the direction in which the side members extend and connected to the rear ends of the pair of side members.

[0012] According to this structure, since the rear cross member has a curved shape connected to each side member, the rigidity of the engine room cross member in the vehicle longitudinal direction can be further improved, and the amount of collision energy absorbed can be increased while further suppressing the amount of obstacle entering.

[0013] In the vehicle front structure disclosed herein, the following embodiment may be adopted, namely, comprising: a dash panel, which is provided at the rear of the vehicle of the engine compartment cross beam and constitutes a partition wall between the vehicle and the vehicle compartment; a floor tunnel panel, which is arranged at the center of the floor of the vehicle compartment and has an upwardly protruding channel cross-section shape connected to the dash panel at a front end, the channel cross-section shape of the floor tunnel panel being composed of a top plate and a pair of longitudinal plates connected to both side ends of the top plate, the respective curved portions of the rear cross beam being directed upward toward the vehicle rear, the rear central portion and the rear end portions of the curved portions being located at the height of the ridgeline of the top plate and the longitudinal plates at the front end of the floor tunnel panel.

[0014] As a result, during a frontal collision, the rear center portion or the rear end of the curved portion can contact the ridgeline at the front end of the tunnel panel, transferring the collision load to the ridgeline portion of the tunnel panel, which has higher strength in the vehicle's longitudinal direction. This reduces the amount of obstacle intrusion while increasing the amount of collision energy absorbed.

[0015] In the vehicle front structure disclosed herein, the front cross member may be a four-sided closed cross-section structure, with each side end portion widening toward the vehicle rear as it moves outward in the vehicle width direction, and a reinforcing plate being installed on the inner surface of the vehicle rear side.

[0016] With this structure, deformation of the front cross member when a load toward the vehicle width direction inner side is input to the front cross member can be suppressed, and the load can be smoothly transmitted to the other front side member.

[0017] In the vehicle front structure disclosed herein, the following method may also be adopted, namely, each of the side members is a four-sided closed cross-section structure in which two plate parts bent into a crank shape are combined together, and each plate part is combined so that the flange connecting each plate part is in the upward or downward direction.

[0018] This ensures that a clearance required for assembly is maintained between each side member and each front side member.

[0019] In the vehicle front structure of the present disclosure, the bent portion of the rear cross member may include at least one low-strength portion having lower strength than other portions.

[0020] As a result, when the curved portion contacts the stronger portion of the dash panel, it collapses in the vehicle's fore-aft direction, causing the high-voltage equipment mounted on the upper side of the engine compartment cross member to move forward relative to the engine compartment cross member. This prevents contact between the high-voltage cables located between the high-voltage equipment and the rear cross member and the high-voltage equipment.

[0021] In the vehicle front structure of the present disclosure, the front cross member may be arranged at a position overlapping a portion of the front side member where an inward fold occurs during a frontal collision in the vehicle longitudinal direction.

[0022] Thus, when one front side member folds inward, the load applied to the vehicle width direction from one front side member is transferred to the other front side member, thereby preventing the front side member from folding inward and causing the other front side member to fold outward toward the rear of the vehicle. This achieves three-section bending of the front side member, effectively absorbing collision energy.

[0023] In the vehicle front structure disclosed herein, the inward folding portion of the front side member may be located at a position on the vehicle width direction outer side of the front side member where a gusset connecting a crash box mounted on the front portion of the front side member and the vehicle width direction outer side surface of the front side member is connected to the front side member.

[0024] The present disclosure can increase the amount of collision energy absorbed while suppressing the amount of obstacle entering during a frontal collision of a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a perspective view showing the vehicle front structure according to the embodiment.

[0026] Figure 2 It is a plan view showing the vehicle front structure according to the embodiment.

[0027] Figure 3 is a partial cross-sectional side view showing the vehicle front structure according to the embodiment, and is Figure 2 AA view shown.

[0028] Figure 4 This is a plan view of an engine compartment cross member of the vehicle front structure according to an embodiment.

[0029] Figure 5 for Figure 4 A cross-sectional view of the side member of the engine compartment cross member shown in FIG. Figure 4 The BB section is shown, and a sectional view of the front side member adjacent to the side member.

[0030] Figure 6 for Figure 4 A cross-sectional view of the front cross member of the engine compartment cross member is shown, and is Figure 4 CC section shown.

[0031] Figure 7 for Figure 4 The cross-sectional view of the rear cross-member of the engine compartment cross-member is shown. Figure 4 DD section shown.

[0032] Figure 8 It is an elevation view of the vehicle front structure according to the embodiment as viewed from the front of the vehicle.

[0033] Figure 9 It is an enlarged plan view of a connection portion between an engine compartment cross member and a front side member of the vehicle front structure according to the embodiment.

[0034] Figure 10 This is an elevation view of the vehicle front structure according to the embodiment as viewed from the front of the vehicle, and is an explanatory diagram showing the steps of mounting the suspension member, the motor, the engine compartment cross member, and the electric power control device on the front compartment at the front of the vehicle.

[0035] Figure 11 It is a plan view showing deformation of the vehicle front structure including the vehicle front structure according to the embodiment when an offset collision occurs on the left side of the vehicle.

[0036] Figure 12 FIG. 1 is a plan view showing deformation of the vehicle front structure when an offset collision occurs on the left side of a vehicle equipped with the vehicle front structure according to the embodiment, and FIG. Figure 11 The state shown is compared to the state after the obstacle enters the image.

[0037] Figure 13 It is a plan view schematically showing deformation of the engine compartment cross member and movement of the electric control device when an offset collision occurs on the left side of a vehicle equipped with the vehicle front structure according to the embodiment.

[0038] Figure 14 The figure is a plan view schematically showing the backward movement of the engine compartment cross member when an offset collision occurs on the left side of a vehicle equipped with the engine compartment cross member of a comparative example. DETAILED DESCRIPTION

[0039] The following describes the vehicle front structure 100 according to an embodiment with reference to the accompanying drawings. The arrows FR, UP, and RH shown in the various drawings represent the front direction (travel direction), upward direction, and right direction of the vehicle 10, respectively. Furthermore, the directions opposite to the arrows FR, UP, and RH represent the rear direction, downward direction, and left direction of the vehicle. In the following description, when only the front-back, left-right, and up-down directions are used, unless otherwise specified, these directions represent the front-back direction of the vehicle front-back direction, the left-right direction of the vehicle left-right direction (vehicle width direction), and the up-down direction of the vehicle up-down direction.

[0040] like Figure 1As shown, the vehicle front structure 100 of the embodiment includes a pair of front side members 11L, 11R, an engine compartment cross member 20, a frame 40, brackets 51L, 51R, apron connection brackets 53L, 53R, and frame connection brackets 52L, 52R.

[0041] First, referring to Figures 1 to 3 At the same time, the overall structure of the vehicle 10 having the vehicle front structure 100 will be described. The vehicle 10 has a front cabin 10F as a space in front of the front panel 16, and a vehicle interior 10R as a space behind the front panel 16. Figure 3 As shown, the front compartment 10F accommodates a driving motor 80 and a power control device 70 serving as high-voltage equipment.

[0042] First, the structure of the front cabin 10F will be described. Figure 1 、 2 As shown, the front compartment 10F includes a pair of front side members 11L, 11R, a pair of suspension tower members 14L, 14R (hereinafter referred to as suspension towers 14L, 14R), fenders 15L, 15R, a pair of upper members 13L, 13R, a dash panel 16, and a front suspension member 60 (hereinafter referred to as suspension member 60). An engine compartment cross member 20, described later, is mounted between the left and right front side members 11L, 11R, and a frame 40 is mounted on the engine compartment cross member 20.

[0043] The front side members 11L and 11R are structural members with a closed cross section that are provided on both sides of the front cabin 10F at the front of the vehicle 10 and extend in the vehicle front-rear direction. Crash boxes 12L and 12R are respectively attached to the top ends. The vehicle width direction outer sides of the crash boxes 12L and 12R and the front side members 11L and 11R are connected by gussets 11a (see FIG. Figure 2 ) and are connected together. The suspension towers 14L, 14R are cylindrical structures on the upper part of the suspension device on which the front wheels are installed, and the inner side in the vehicle width direction is connected to the outer side in the vehicle width direction of the front side members 11L, 11R. The fender parts 15L, 15R are the front parts of the suspension towers 14L, 14R that accommodate the wheel covers of the front wheels, and are composed of plate parts. A part of the lower end of the fender parts 15L, 15R is connected to the outer side in the vehicle width direction of the front side members 11L, 11R. The upper members 13L, 13R are strength members that are connected to the outer side in the vehicle width direction of the suspension towers 14L, 14R and the fender parts 15L, 15R and extend in the front-rear direction of the vehicle. The front of the upper members 13L, 13R is bent downwardly of the vehicle and bent inwardly in the vehicle width direction, thereby being connected to the outer side in the vehicle width direction in front of the front side members 11L, 11R. In addition, as Figure 2As shown, the rear portions of the upper members 13L and 13R are connected to the front pillars 17L and 17R, respectively. The dash panel 16 is a partition that separates the front cabin 10F from the vehicle interior 10R. The suspension member 60 is a reinforcement component mounted on the underside of the front side members 11L and 11R and carries the front wheel suspension system.

[0044] As described above, the front compartment 10F is a space defined in the vehicle width direction by the front side members 11L, 11R, the upper members 13L, 13R, the suspension towers 14L, 14R, and the fenders 15L, 15R, and is defined by the suspension member 60 at the bottom, the dash panel 16 at the rear, and the radiator support (not shown) at the front. Figure 3 As shown, a motor 80 is mounted on the upper side of the suspension member 60. The front portion of the motor 80 is mounted to the suspension member 60 via two front mounting brackets 81. A rear mounting bracket 82 behind the motor 80 is mounted on a support member 69 extending in the vehicle width direction within the front compartment 10F. Furthermore, the upper portion of the motor 80 extends through the inner periphery of the engine compartment cross member 20 and protrudes to the upper side of the engine compartment cross member 20.

[0045] Next, the structure of the car 10R will be described. Figure 2 As shown, the rear of the dash panel 16 forms the vehicle compartment 10R. A floor panel 18 constituting the floor of the vehicle compartment 10R is provided in the vehicle compartment 10R, and a floor tunnel panel 19 is provided at the center of the floor panel 18 in the vehicle width direction. The floor tunnel panel 19 has a groove-shaped cross-section that is convex upward and is composed of a top plate 19a and a pair of longitudinal plates 19b connected to both side ends of the top plate 19a. The connection between the top plate 19a and the longitudinal plates 19b constitutes the ridgeline 19c of the groove-shaped cross-section of the floor tunnel panel 19. As shown in FIG. Figure 3 As shown, the front end of the floor tunnel panel 19 is connected to the peripheral edge of the cutout portion 16 a provided in the dash panel 16 .

[0046] Next, the engine compartment cross beam 20 will be described. Figure 4 As shown, the engine compartment cross member 20 is an annular member consisting of a pair of left and right side members 21L, 21R, a front cross member 24, and a rear cross member 27. The rear cross member 27 is curved so as to convexly extend toward the rear of the vehicle and has a shape similar to the Latin capital letter D when viewed from above.

[0047] like Figure 2 As shown, the left and right side members 21L, 21R are four-sided closed cross-section members that are mounted on the vehicle width direction inner sides of the left and right front side members 11L, 11R via brackets 51L, 51R, respectively, and extend in the vehicle front-rear direction. Figure 5As shown, the left side member 21L is a four-sided closed cross-section structure composed of two plate members 21a and 21b bent into a crank shape. The plate members 21a and 21b are combined so that the flanges 21c and 21d connecting the plate members 21a and 21b are in the upward or downward direction. The left side member 21L is configured so that a gap S is left between the outer surface in the vehicle width direction and the inner surface in the vehicle width direction of the left front side member 11L. Since the right front side member 11R and the right side member 21R are symmetrical with the left front side member 11L and the left side member 21L, their description is omitted. In addition, Figure 4 The reference numeral 28 in FIG. 1 is a bolt 55 (see FIG. 28 ) which is passed through the brackets 51L and 51R to fix them. Figure 9 、 10 ) bolt holes.

[0048] like Figure 4 As shown, the front cross member 24 is a member having a four-sided closed cross-section structure that connects the front ends 21Lf, 21Rf of the left and right side members 21L, 21R in the vehicle width direction, and is composed of a front center portion 22 of a fixed cross-section and left and right side ends 23L, 23R whose widths widen toward the rear of the vehicle as they approach the outer sides in the vehicle width direction. The rear portions 23Lr, 23Rr of the left and right side ends 23L, 23R on the outer sides in the vehicle width direction are connected to the front ends 21Lf, 21Rf of the left and right side members 21L, 21R. Figure 6 As shown, the front center portion 22 of the front cross member 24 is a four-sided closed cross-section structure composed of two plate members 22a and 22b bent into a crank shape, and each plate member 22a and 22b is combined so that the flanges 22c and 22d connecting the plate members 22a and 22b are in the upward or downward direction. The side end portions 23L and 23R also have a four-sided closed cross-section structure of the same structure. A reinforcing plate 31 bent into a mountain shape is installed on the inner surface of the plate member 22a of the front center portion 22 on the rear side and the lower side of the vehicle. As shown in FIG. Figure 4 As shown, the reinforcing plate 31 extends from the front center portion 22 to the inside of the left and right side ends 23L, 23R. The reinforcing plate 31 disposed in the side ends 23L, 23R is wider than the reinforcing plate 31 disposed in the front center portion 22.

[0049] At the front portion of the left and right side ends 23L, 23R on the outside in the vehicle width direction, there is provided an inclined portion 23a whose upper surface height decreases toward the front and the outside in the vehicle width direction. In addition, near the rear portions 23Lr, 23Rr of the left and right side ends 23L, 23R, there is provided a bolt 55 (see FIG. 1 ) for passing through and fixing the brackets 51L, 51R. Figure 9 、10 ) bolt holes 29, the left and right side ends 23L, 23R and the side members 21L, 21R are mounted on the left and right front side members 11L, 11R through brackets 51L, 51R.

[0050] As will be described below, when an offset collision occurs on the left side of the vehicle 10 equipped with the vehicle front structure 100 of the embodiment, the left front side member 11L folds inward in the vehicle width direction at the initial stage of the collision. The front cross member 24 is arranged at a position overlapping with the folding portion of the front side member 11L in the vehicle front-rear direction. The folded portion of the left front side member 11L collides with the end surface 23Lg of the left side end portion 23L of the front cross member 24, thereby causing the front cross member 24 to fold inward. Figure 4 At the position indicated by arrow 99, a load F directed inward in the vehicle width direction is applied to the front cross member 24. The vehicle rearward surface of the plate member 22a of the front center portion 22 of the front cross member 24 is positioned so as to be offset forward of the vehicle by a distance d relative to the position where the load F is applied. Furthermore, in the event of an offset collision on the right side of the vehicle 10, the right front side member 11R folds inward, colliding with the end surface 23Rg of the right side end portion 23R of the front cross member 24.

[0051] like Figure 4 As shown, the rear cross member 27 is composed of a rear center portion 25 extending in the vehicle width direction, and two bent portions 26L and 26R connecting the left and right end portions 25Ls and 25Rs of the rear center portion 25 to the rear ends 21Lr and 21Rr of the left and right side members 21L and 21R, respectively. The left and right bent portions 26L and 26R are curved toward the vehicle front from the left and right end portions 25Ls and 25Rs of the rear center portion 25, respectively. The respective top ends 26Lf and 26Rf extend in the extending direction of the left and right side members 21L and 21R, respectively, and are connected to the rear ends 21Lr and 21Rr of the left and right side members 21L and 21R, respectively. As a result, the top ends 26Lf and 26Rf of the curved portions 26L and 26R of the rear cross member 27 and the rear ends 21Lr and 21Rr of the side members 21L and 21R are continuous, and the rear cross member 27 and the side members 21L and 21R are continuous in a curved shape, thereby improving the rigidity of the engine compartment cross member 20 in the vehicle front-rear direction.

[0052] like Figure 7As shown, the rear center portion 25 of the rear cross member 27 has a four-sided closed cross-section structure composed of a plate member 25a bent into a mountain shape and a plate member 25b bent into a crank shape. The plate members 25a and 25b are assembled so that the flange 25c connecting the plate members 25a and 25b extends upward, and the flange 25e on the rear side extends toward the rear of the vehicle. A reinforcing plate 32, bent into a mountain shape, is attached to the rearward inner surface of the plate member 25b of the rear center portion 25 and the inner surface of the underside of the plate member 25a.

[0053] Similar to the side members 21L and 21R described previously, the left and right curved portions 26L and 26R have a four-sided closed cross-section structure formed by combining two plate members bent into a crank shape. Rigid reinforcement plates 33L and 33R, similar to the reinforcement plate 31, are attached to the inner surface of each curved portion 26L and 26R, along the longitudinal center of the vehicle rear side. The areas near the rear ends 26Lr and 26Rr and near the top ends 26Lf and 26Rf of the curved portions 26L and 26R, where the reinforcement plates 33L and 33R are not provided, form low-strength portions, which are lower in strength than the areas where the reinforcement plates 33L and 33R are provided.

[0054] like Figure 3 As shown, the curved portions 26L and 26R of the rear cross member 27 face upward toward the vehicle rearward, and the rear center portion 25 and the rear end portions 26Lr and 26Rr of the left and right curved portions 26L and 26R are positioned at the height of the top plate 19a and the ridgeline 19c of the longitudinal plate 19b at the front end of the floor tunnel panel 19. Furthermore, the rear center portion 25 of the rear cross member 27 and the rear end portions 26Lr and 26Rr of the left and right curved portions 26L and 26R may be positioned so as to overlap the top plate 19a at the front end of the floor tunnel panel 19 when viewed from the front of the vehicle.

[0055] Next, the frame 40 will be described. Figure 2 As shown, the frame 40 is composed of a frame cross member 41 extending in the vehicle width direction, and frame members 42 and 43 extending from the frame cross member 41 toward the rear of the vehicle. Figure 3 As shown, the frame cross member 41 is connected to the upper ends of the respective brackets 51L, 51R via the frame connection brackets 52L, 52R. Figure 2 、 3As shown, frame members 42 and 43 are fastened to frame member connecting brackets 44 and 45, respectively, provided on curved portions 26R and 26L of the engine compartment cross member 20, by bolts 44a and 45a. A power control unit 70 is mounted on the frame 40. High-voltage cables 75, 76, and 77 are connected to the power control unit 70 for connection to a battery (not shown). The high-voltage cables 75, 76, and 77 are arranged inside the floor tunnel panel 19, which has an upwardly projecting channel-shaped cross-section. They pass through the cutout 16a of the dash panel 16 and into the front cabin 10F. They then pass through the vehicle front side of the rear center portion 25 of the rear cross member 27 and are connected to the terminals of the power control unit 70, which are arranged on the upper side of the frame 40.

[0056] Next, the connection structure between the engine compartment cross member 20 and the left and right front side members 11L, 11R and the left and right apron portions 15L, 15R, and the connection structure of the frame 40 to the engine compartment cross member 20 will be described.

[0057] like Figure 8 、 9 As shown, the left and right side members 21L, 21R of the engine compartment cross member 20 and the left and right end portions 23L, 23R of the front cross member 24 are connected to the left and right front side members 11L, 11R via brackets 51L, 51R. The brackets 51L, 51R have roughly trapezoidal plates 51La, 51Ra, with their inner lengths in the vehicle width direction slightly longer than their outer lengths, and two protrusions 51Lb, 51Lc, 51Rb, and 51Rc projecting upward from the plates 51La, 51Ra. The inner sides of the plates 51La, 51Ra in the vehicle width direction are fastened to the left and right side members 21L, 21R and the left and right end portions 23L, 23R of the front cross member 24 via three bolts 55. The outer sides of the plates 51La, 51Ra in the vehicle width direction are connected to the left and right front side members 11L, 11R via two bolts 54.

[0058] At the upper ends of the protrusions 51Lb, 51Rb arranged on the outside in the vehicle width direction, the ends of the baffle portion connecting brackets 53L, 53R on the inside in the vehicle width direction are connected by two bolts 58, and the ends on the opposite sides of the baffle portion connecting brackets 53L, 53R are connected to the baffle portions 15L, 15R by bolts 57.

[0059] The vehicle width direction outer ends of left and right frame connecting brackets 52L and 52R are connected to the upper portions of the protrusions 51Lc and 51Rc, which are arranged on the vehicle width direction inner side, by two bolts 59a. The opposite ends of the frame connecting brackets 52L and 52R are connected to the left and right ends of the frame cross member 41 by bolts 59b.

[0060] Next, in reference Figure 10 At the same time, the process of mounting the motor 80, the electric power control device 70, the engine compartment cross member 20, and the suspension member 60 in the front compartment 10F will be described.

[0061] like Figure 10 As shown, the motor 80 is mounted on the upper portion of the suspension member 60 via the left and right front mounting members 81. Next, the temporary member 65 is mounted on the suspension member 60, and the engine compartment cross member 20 is mounted thereon. The temporary member 66 is mounted on the upper portion of the engine compartment cross member 20, and the frame 40 is mounted thereon. At this time, the frame members 42 and 43 of the frame 40 (see Figure 2 ) are pre-mounted on the frame member connecting brackets 44, 45 mounted on the engine compartment cross beam 20 (refer to Figure 2 Then, the electric power control device 70 is mounted on the frame 40, thereby assembling the motor 80, the electric power control device 70, the engine compartment cross beam 20, the frame 40 and the suspension member 60 into an integrated assembly 85.

[0062] Next, a gap S for installation is provided between the vehicle width direction outer surfaces of the left and right side members 21L, 21R of the engine compartment cross member 20 and the vehicle width direction inner surfaces of the left and right front side members 11L, 11R (see FIG. Figure 5 ) to align the assembly 85, and push the assembly 85 from the lower side of the vehicle 10 to between the left and right front side members 11L, 11R.

[0063] After the assembly 85 is raised to a predetermined height relative to the engine compartment cross member 20, the plate portions 51La and 51Ra of the brackets 51L and 51R are aligned from above with the upper surfaces of the front side members 11L and 11R, the side members 21L and 21R, and the left and right end portions 23L and 23R of the front cross member 24. Bolts 54 and 55 are then inserted from above to fasten the plate portions 51La and 51Ra, the left and right front side members 11L and 11R, the left and right side members 21L and 21R, and the left and right end portions 23L and 23R together. Furthermore, the fastening member 62 is inserted from below the suspension member 60 to fasten the suspension member 60 to the suspension member support 11b extending below the front side members 11L and 11R.

[0064] Next, the baffle connecting brackets 53L and 53R are aligned with the upper surfaces of the baffles 15L and 15R and the upper portions of the protrusions 51Lb and 51Rb from above, and bolts 57 and 58 are passed through from above to fasten the baffle connecting brackets 53L and 53R to the upper surfaces of the baffles 15L and 15R and the upper portions of the protrusions 51Lb and 51Rb using the bolts 57 and 58. Furthermore, the upper ends of the frame connecting brackets 52L and 52R and the protrusions 51Lc and 51Rc are connected to the left and right ends of the frame cross member 41 from above using bolts 59a and 59b.

[0065] After assembly 85 is attached to left and right front side members 11L, 11R, suspension member 60, and fenders 15L, 15R, temporary components 65, 66 are removed. In this manner, in the vehicle front structure 100 of the embodiment, assembly 85, which includes motor 80, power control unit 70, engine compartment cross member 20, frame 40, and suspension member 60, can be assembled from the bottom side of vehicle 10 in an integrated manner.

[0066] Next, in reference Figures 11 to 13 The following also describes the deformation of various components of a vehicle 10 equipped with a vehicle front structure 100 according to an embodiment when an offset collision occurs on the left side. In the following description, an offset collision refers to a head-on collision of the aluminum honeycomb barrier 90 with a portion that is 40% of the width of the vehicle.

[0067] Initially, obstacle 90 collides with bumper reinforcement 68, which is mounted forward of left and right front side members 11L and 11R via crash boxes 12L and 12R. Bumper reinforcement 68 bends to follow the shape of obstacle 90. At this point, the left side of bumper reinforcement 68 bears the greater rearward impact load, causing the left crash box 12L, located behind it, to undergo plastic deformation in the compression direction, absorbing the impact. The impact load is then transmitted from the left crash box 12L to the front end of the left front side member 11L.

[0068] The left front side member 11L receives a rearward impact load and a load input inward in the vehicle width direction from the left crash box 12L through the left gusset plate 11a. Consequently, the left front side member 11L bends inward at position 111 where the left gusset plate 11a connects to the left front side member 11L, while receiving the rearward load and causing it to fold inward. Consequently, position 111 becomes the location where the left front side member 11L folds inward.

[0069] The left front side member 11L folds inwardly, and the folded portion collides with the end face 23Lg of the left side end portion 23L of the front cross member 24, thereby causing the left side end portion 23L to be deformed as shown in FIG. Figure 4 As described above, a load F is inputted inward in the vehicle width direction. This load F is transmitted to the right front side member 11R on the opposite side via the front cross member 24. Consequently, the inward folding of the left front side member 11L stops, and the left front side member 11L bends outward at position 112 and further bends inward again at position 113, thereby deforming in a three-step bending manner.

[0070] In this way, the left side of the engine compartment cross beam 20 is moved toward the rear of the vehicle by performing three-section bending deformation of the left front side member 11L. On the other hand, the right front side member 11R has not moved much from its original position, and the right side of the engine compartment cross beam 20 has not retreated much. Therefore, the engine compartment cross beam 20 rotates in a manner of retreating to the left toward the rear of the vehicle, so that the left end 25Ls of the rear center portion 25 and the vicinity of the rear end 26Lr of the left curved portion 26L come into contact with the front panel 16. The front end of the floor tunnel panel 19 is connected to the vehicle compartment 10R side of the front panel 16. Therefore, the left end 25Ls of the rear center portion 25 and the vicinity of the rear end 26Lr of the left curved portion 26L are located near the ridgeline 19c of the connection between the top plate 19a of the floor tunnel panel 19 and the left longitudinal plate 19b when viewed from above. In addition, as shown in FIG. Figure 3 As previously described, the left end 25Ls of the rear center portion 25 and the rear end 26Lr of the left curved portion 26L are located at the level of the ridgeline 19c of the floor tunnel panel 19. Therefore, even when viewed from the side, the vicinity of the left end 25Ls of the rear center portion 25 and the rear end 26Lr of the left curved portion 26L are located forward of the ridgeline 19c of the floor tunnel panel 19. Consequently, the rear center portion 25 and the rear end 26Lr of the left curved portion 26L of the rear cross member 27 contact the dash panel 16 forward of the ridgeline 19c of the floor tunnel panel 19, transmitting the collision load to the ridgeline 19c of the floor tunnel panel 19.

[0071] Although in this state, the engine compartment cross beam 20 Figure 13 From the initial state shown by the dotted line in FIG. 1 , the vehicle rotates in a manner of retreating to the left side of the vehicle as shown by the arrows 95 and 96, but Figure 13As shown by the dashed line in the figure, the D-shaped planar shape remains unchanged when viewed from above. Furthermore, the relative positional relationship between the engine compartment cross member 20 and the frame 40, the relative positional relationship between the engine compartment cross member 20 and the power control unit 70 mounted on the frame 40, and the relative position of the high-voltage cables 75-77 running vertically between the power control unit 70 and the rear cross member 27 remain unchanged. Therefore, the high-voltage cables 75-77 reside in the space between the rear cross member 27 and the power control unit 70 and do not come into contact with the engine compartment cross member 20 or the power control unit 70.

[0072] When the obstacle is 90 degrees from Figure 11 As the vehicle moves further from the state of the rear center 25, the load in the vehicle front-rear direction applied to the left end 25Ls of the rear center 25 and the rear end 26Lr of the left curved portion 26L increases. As a result, the reaction force toward the front of the vehicle received by the left end 25Ls of the rear center 25 and the rear end 26Lr of the left curved portion 26L from the ridge line 19c of the floor tunnel panel 19 with high strength also increases. Figure 12 as well as Figure 13 As shown by the solid line and arrow mark 97, the left end portion 25Ls of the rear center portion 25 and the rear end portion 26Lr of the left curved portion 26L are deformed in a manner of being crushed toward the front of the vehicle. This is caused by the following situation, that is, as shown in FIG. Figure 4 As described above, the bent portion 26L has a low-strength portion near the rear end 26Lr and the tip 26Lf where no reinforcing plate 33L is provided, and has a small bending radius, making it easy to deform.

[0073] By this transformation, Figure 12 as well as Figure 13 As indicated by the solid line and arrow 98, the frame 40 deforms relative to the engine compartment cross member 20 and rotates so that the left side of the power control unit 70 moves toward the front of the vehicle, thereby causing the left side of the power control unit 70 to move forward relative to the engine compartment cross member 20. This creates space for the high-voltage cables 75-77 to pass vertically between the rear center portion 25, the left curved portion 26, and the power control unit 70, thereby maintaining a state in which the high-voltage cables 75-77 do not contact the engine compartment cross member 20 or the power control unit 70.

[0074] Although the deformation of the left side of the vehicle 10 during an offset collision has been described above, the deformation of the right side of the vehicle 10 during an offset collision is bilaterally symmetrical to the deformation of the left side of the vehicle 10 , and thus the description thereof will be omitted.

[0075] As described above, in the vehicle front structure 100 of the embodiment, by curving the rear cross member 27 to convexly project toward the vehicle rear, the vehicle front-rear rigidity of the engine compartment cross member 20 can be enhanced. In particular, the adoption of a curved shape that connects the top ends 26Lf, 26Rf of the curved portions 26L, 26R of the rear cross member 27 to the rear ends 21Lr, 21Rr of the side members 21L, 21R, and further connects the rear cross member 27 and the side members 21L, 21R, further enhances the vehicle front-rear rigidity of the engine compartment cross member 20. This prevents deformation of the engine compartment cross member 20 due to a frontal collision load, and allows for smooth transmission of the collision load from the rear cross member 27 to rearward components.

[0076] Furthermore, in the event of an offset collision on the left side of the vehicle 10, the engine compartment cross member 20 rotates, causing the left end portion 25Ls of the rear center portion 25 and the vicinity of the rear end portion 26Lr of the left curved portion 26L to collide with the dash panel 16. In this way, since the curved portion collides with the dash panel 16, it is possible to suppress the collision. Figure 14 The corner portion 202 of the engine compartment cross member 201 of the comparative example shown collides with the dash panel 16 and damages the dash panel 16. Figure 14 In FIG. 1 , the solid line represents the engine compartment cross beam 201 before the offset collision, the dotted line represents the engine compartment cross beam 201 during the offset collision, and the arrow mark 209 represents the backward movement of the engine compartment cross beam 201 during the offset collision.

[0077] Furthermore, since deformation of the engine compartment cross beam 20 can be suppressed by bending the rear cross beam 27 in a convex manner toward the rear, the relative positions of the engine compartment cross beam 20, the power control device 70 and the high-voltage cables 75 to 77 will not change in the initial state in which the engine compartment cross beam 20 collides with the front panel 16 due to an offset collision, thereby suppressing contact between the high-voltage cables 75 to 77 and the engine compartment cross beam 20 and the power control device 70.

[0078] Furthermore, in the vehicle front structure 100 of the embodiment, the rear center portion 25 of the rear cross member 27 and the rear end portions 26Lr and 26Rr of the respective curved portions 26L and 26R are positioned at the same height as the ridgeline 19c at the front end of the floor tunnel panel 19. This allows the curved portions 26L and 26R of the rear cross member 27 to face upward toward the vehicle rear. Therefore, during an offset collision, the collision load can be transferred from the engine compartment cross member 20 to the ridgeline 19c of the floor tunnel panel 19, which has greater strength. This allows the absorption of collision energy to be increased while suppressing the amount of intrusion of the obstacle 90.

[0079] Furthermore, in the vehicle front structure 100 of the embodiment, the front cross member 24 is formed by a front center portion 22 of constant width and left and right side ends 23L and 23R that widen toward the vehicle rear in the vehicle width direction. A reinforcing plate 31 is disposed within the front cross member 24. Consequently, even if the rear side surface of the front center portion 22 is offset by a distance d toward the vehicle front-to-back direction relative to the vehicle front-to-back direction position of a load F applied to the front cross member 24 from the left side toward the vehicle rear in an offset collision on the left side of the vehicle, deformation of the front cross member 24 due to the applied load F is suppressed, and the load F is smoothly transmitted to the opposite right front side member 11R. Consequently, the left front side member 11L is deformed in a three-section bend pattern, thereby absorbing impact energy. Furthermore, since the rear side surface of the front center portion 22 is offset by a distance d toward the vehicle front, the inner circumference of the engine compartment cross member 20 can be increased. The motor 80 mounted on the suspension member 60 has its upper portion extending through the inner periphery of the engine compartment cross beam 20 and protruding to the upper side of the engine compartment cross beam 20 . Therefore, by increasing the inner periphery of the engine compartment cross beam 20 , a larger motor 80 can be mounted on the suspension member 60 .

[0080] Furthermore, in the vehicle front structure 100 of the embodiment, the left and right side members 21L and 21R have a four-sided closed cross-section structure formed by combining two crank-shaped plate members 21a and 21b. Each plate member 21a and 21b is assembled so that the flanges 21c and 21d connecting the plate members 21a and 21b face upward or downward. This ensures the required clearance S between the left and right side members 21L and 21R and the left and right front side members 11L and 11R during assembly. Furthermore, the assembly 85 comprising the motor 80, power control unit 70, engine compartment cross member 20, frame 40, and suspension member 60 can be integrated and assembled from the bottom of the vehicle 10. This allows for quick installation of the assembly 85. Furthermore, since the vehicle's engine can be installed from the bottom of the vehicle using the same equipment, no new equipment investment is required.

[0081] Furthermore, in the vehicle front structure 100 of the embodiment, the top ends 26Lf, 26Rf and rear ends 26Lr, 26Rr of the curved portions 26L, 26R of the rear cross member 27 form low-strength portions, which are weaker than the rest of the structure. Therefore, in the later stages of an offset collision on the left side of the vehicle 10, if the left curved portion 26L receives a significant reaction force from the front end of the ridgeline 19c of the floor tunnel panel 19, the left curved portion 26L will collapse in the vehicle front-rear direction, causing the left side of the power control unit 70 to move forward relative to the engine compartment cross member 20. This prevents the high-voltage cables 75-77 disposed between the power control unit 70 and the rear cross member 27 from contacting the power control unit 70 or the rear cross member 27.

[0082] In the vehicle front structure 100 of the embodiment, each of the curved portions 26L and 26R has two low-strength portions. However, the present invention is not limited thereto. For example, only the rear end portions 26Lr and 26Rr may be low-strength portions.

[0083] As described above, the vehicle front structure 100 according to the embodiment can increase the amount of collision energy absorbed while suppressing the amount of entry of the obstacle 90 during a frontal collision of the vehicle 10 .

Claims

1. A vehicle front structure comprising: a pair of front side members provided on both sides of the front of the vehicle and extending in the front-rear direction of the vehicle; an engine compartment cross member mounted between a pair of said front side members; a dash panel disposed at the vehicle rear of the engine compartment cross member and constituting a partition wall between the vehicle and the vehicle compartment; A floor tunnel panel is arranged at the center of the floor of the vehicle compartment and has an upwardly protruding channel cross-section shape with a front end connected to the front panel. The vehicle front structure is characterized in that: The engine compartment cross beam is an annular component having the following components: a pair of side members, each of which is attached to the vehicle width direction inner side of each of the front side members and each extends in the vehicle front-rear direction; a front cross member connecting respective front ends of the pair of side members in the vehicle width direction; a rear cross member connecting the rear ends of the pair of side members in the vehicle width direction, The rear cross member is curved so as to be convex toward the rear side of the vehicle. The rear crossbeam has: a rear center portion extending in the vehicle width direction; Two curved portions, each curved from both ends of the rear center portion toward the front of the vehicle, with each top end extending in the direction in which each of the side members extends and connected to each of the rear ends of the pair of side members, The channel-shaped cross-section of the floor channel panel is composed of a top plate and a pair of longitudinal plates connected to both side ends of the top plate. Each of the curved portions of the rear cross member is directed upward toward the vehicle as it moves toward the rear of the vehicle. The rear center portion and the rear end portion of the curved portion are located at the height of a ridgeline between the top plate and the vertical plates at the front end of the floor tunnel panel.

2. The vehicle front structure according to claim 1, wherein: The front crossbeam is a four-sided closed cross-section structure. The width of each side end portion becomes wider toward the rear of the vehicle as it moves toward the outer side in the vehicle width direction. A reinforcement plate is attached to the inner surface on the rear side of the vehicle.

3. The vehicle front structure according to claim 1, wherein: Each of the side members has a four-sided closed cross-section structure formed by combining two plate members bent into a crank shape, and the plate members are combined so that the flange connecting the plate members faces upward or downward.

4. The vehicle front structure according to claim 1, wherein: The bent portion of the rear cross member has at least one low-strength portion having lower strength than other portions.

5. The vehicle front structure according to claim 1, wherein: The front cross member is arranged at a position overlapping with a portion of the front side member where an inward fold occurs during a frontal collision in the vehicle front-rear direction.

6. The vehicle front structure according to claim 5, wherein: The inward folding portion of the front side member is a position where a gusset connecting a crash box attached to a front portion of the front side member and a vehicle widthwise outer surface of the front side member is connected to the front side member.

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