JP7552302B2 - Vehicle undercarriage - Google Patents

Description

This disclosure relates to the undercarriage of a vehicle.

Patent document 1 discloses an example of a vehicle underbody structure. Specifically, this patent document 1 discloses a vehicle that includes a battery arranged on the vehicle body lower side of a floor panel, a battery frame to which the battery is attached, a protective member that covers the side wall portion of the battery frame, and an energy absorbing member that is arranged on the outer side of the protective member in the vehicle width direction.

Here, the protective member according to Patent Document 1 is configured to be connected to the floor panel via the side frame, and functions as a mounting bracket for connecting the battery and the battery frame to the vehicle body. The energy absorbing member described above is configured integrally with the protective member as a mounting bracket.

According to Patent Document 1, the protective member and the energy absorbing member are formed to extend along the front-rear direction of the vehicle. The energy absorbing member abuts against or is close to the side wall portion of the battery frame and covers the side wall portion.

JP 2014-80116 A

However, as described in the above-mentioned Patent Document 1, if the protective member serving as the mounting bracket, and in turn the energy absorbing member, were to be extended over the entire area in the fore-aft direction of the vehicle, this would increase the weight of the vehicle and lead to increased manufacturing costs, which would be inconvenient.

On the other hand, simply making the energy absorbing member more compact solves issues related to weight and manufacturing costs, but is inconvenient in terms of ensuring safety performance in the event of a collision.

The technology disclosed here has been developed in light of these issues, and its purpose is to reduce weight and manufacturing costs while ensuring the safety performance of a vehicle equipped with an energy absorbing member that is integral with the mounting bracket.

A first aspect of the present disclosure relates to an undercarriage of a vehicle. This vehicle comprises a battery unit arranged on the underside of a floor panel, extending toward the side end of the vehicle in the vehicle width direction while extending so as to pass through the center of gravity of the vehicle in the vehicle fore-and-aft direction, and a mounting bracket attached to an outer surface portion of the battery unit facing outward in the vehicle width direction and connected to the floor panel, wherein a plurality of the mounting brackets are arranged at intervals in the vehicle fore-and-aft direction, and the mounting brackets include at least a first mounting bracket extending along the vehicle fore-and-aft direction so as to pass through the center of gravity of the battery unit in the vehicle fore-and-aft direction, and an energy absorbing member is integrally provided only on the first mounting bracket of the mounting brackets, and the first mounting bracket is fastened to a lower end of the floor side frame so as to be connected to the floor panel via a floor side frame, the floor side frame is adjacent to a side sill in the vehicle width direction, and in the vehicle height direction, the lower end of the floor side frame is arranged at a higher position than the lower end of the side sill, and in the vehicle height direction, the lower end of the energy absorbing member is arranged at the same height as the lower end of the side sill .

According to the first aspect of the present disclosure, the center of gravity of the vehicle is located between the front end and rear end of the battery unit in the vehicle longitudinal direction. In this case, the center of gravity of the battery unit and the center of gravity of the vehicle are close to each other. In addition, the center of gravity of the battery unit is located between the front end and rear end of the first mounting bracket in the vehicle longitudinal direction. In this case, the first mounting bracket is positioned so as to include the center of gravity of the battery unit. The first mounting bracket is required to have relatively high safety performance compared to other mounting brackets.

According to the first aspect of the present disclosure, an energy absorbing member is provided only on the first mounting bracket, which is adjacent to the center of gravity of the battery unit and therefore the center of gravity of the vehicle, among the multiple mounting brackets. While high safety performance is ensured in the first mounting bracket, weight and manufacturing costs can be reduced by not providing an energy absorbing member in the other mounting brackets. This makes it possible to reduce weight and manufacturing costs while ensuring the safety performance of the vehicle.

Furthermore, according to the first aspect, the energy absorbing member can be covered and hidden by the side sill, which is advantageous in terms of improving the design of the vehicle.

Furthermore, according to a second aspect of the present disclosure, the powertrain of the vehicle may be disposed forward in the vehicle longitudinal direction, and the first mounting bracket may be disposed forward in the vehicle longitudinal direction relative to other mounting brackets on the mounting bracket.

According to the second aspect, the vehicle's powertrain is disposed at the front of the vehicle. In this case, the center of gravity of the vehicle, and therefore the center of gravity of the battery unit adjacent to it, is located at the front in the fore-and-aft direction of the vehicle.

According to the second aspect, the energy absorbing member is provided only on the mounting bracket located on the front side. By limiting the mounting brackets on which the energy absorbing member should be provided, the multiple mounting brackets as a whole can be configured more compactly.

Furthermore, according to a third aspect of the present disclosure, the first mounting bracket may have a longer dimension in the fore-and-aft direction of the vehicle than the other mounting brackets.

According to the third aspect, by setting the dimensions of the first mounting bracket to be long, it is possible to set the dimensions of the energy absorbing member to be longer. This is advantageous in ensuring the safety performance of the vehicle. On the other hand, by setting the dimensions of the other mounting brackets to be short, it is advantageous in reducing weight and manufacturing costs.

According to a fourth aspect of the present disclosure, the first mounting bracket of the mounting brackets may be formed from an extrusion material, and the other mounting brackets other than the first mounting bracket may be formed from a press material.

According to the fourth aspect, the first mounting bracket is advantageous in that it can be integrally provided with an energy absorbing member, while the other mounting brackets are advantageous in that they can be made lighter.

Furthermore, according to a fifth aspect of the present disclosure, the first mounting bracket may have a mounting plate fastened to the floor side frame, the mounting plate being formed in a plate shape extending in the fore-and-aft direction of the vehicle, and the mounting plate, together with other portions of the first mounting bracket, may constitute the energy absorbing member having a hollow closed cross-section.

According to the fifth aspect, the entire parts constituting the first mounting bracket constitute the energy absorbing member, which improves the performance of the energy absorbing member and is advantageous in terms of ensuring the safety performance of the vehicle.

Furthermore, according to a sixth aspect of the present disclosure, the vehicle may be provided with piping extending in a fore-and-aft direction of the vehicle, and the piping may be positioned inward of the vehicle width direction tip of the energy absorbing member in the vehicle width direction, and positioned below the mounting plate in the vehicle height direction.

According to the sixth aspect, the piping can be protected by the energy absorbing member, which is advantageous in ensuring the safety performance of the vehicle.

As described above, according to the present disclosure, in a vehicle equipped with an energy absorbing member that is integrally configured with a mounting bracket, it is possible to reduce weight and manufacturing costs while ensuring the safety performance of the vehicle.

FIG. 1 is a schematic diagram illustrating a drive system of a vehicle to which a vehicle underbody structure according to the present disclosure is applied. FIG. 2A is a plan view illustrating an example of the configuration of the front side of the vehicle as viewed from above. FIG. 2B is a bottom view illustrating the configuration of the front side of the vehicle as viewed from below. FIG. 3 is a diagram illustrating an example of the configuration inside the floor tunnel as viewed from the right side of the vehicle. FIG. 4 is a plan view illustrating the configuration around the battery unit as viewed from above the vehicle. FIG. 5 is a perspective view illustrating the configuration around the battery unit as viewed obliquely from above. FIG. 6 is a side view illustrating the layout of the outer bracket. FIG. 7 is a cross-sectional view illustrating the I-I cross section of FIG. FIG. 8 is a cross-sectional view illustrating the cross section taken along line II-II of FIG. FIG. 9 is a cross-sectional view illustrating the cross section taken along line III-III in FIG. FIG. 10 is a perspective view illustrating the first left outer bracket as viewed from diagonally above and outside in the vehicle width direction. FIG. 11 is a perspective view illustrating the first left outer bracket as viewed from the outside in the vehicle width direction and obliquely from below. FIG. 12 is a front view illustrating the first left outer bracket as viewed from the front side in the vehicle front-rear direction. FIG. 13 is a perspective view illustrating the second left outer bracket as viewed from the outside in the vehicle width direction and diagonally from above. FIG. 14 is a side view illustrating the second left outer bracket as viewed from the outside in the vehicle width direction.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the following description is merely an example.

Figure 1 is a schematic diagram illustrating the drive system of a vehicle 1 to which the vehicle undercarriage structure according to the present disclosure is applied. Also, Figure 2A is a plan view illustrating the configuration of the front part of the vehicle 1 as viewed from above, and Figure 2B is a bottom view illustrating the configuration of the front part of the vehicle 1 as viewed from below.

In the following description, the terms "front," "rear," "upper," and "lower" are each defined with respect to vehicle 1. That is, in the following description, "front" refers to the front side in the vehicle's fore-and-aft direction, and "rear" refers to the rear side in the vehicle's fore-and-aft direction. Similarly, "upper" refers to the upper side in the vehicle height direction, and "lower" refers to the lower side in the vehicle height direction. In the following description, the vehicle's fore-and-aft direction may be referred to simply as the "fore-and-aft direction," the vehicle height direction may be referred to simply as the "up-and-down direction," and the vehicle width direction may be referred to simply as the "left-and-right direction."

The terms "left" and "right" in the following description are also defined with respect to vehicle 1. That is, in the following description, "left" refers to the left side in the vehicle width direction when vehicle 1 is viewed from the rear to the front, and "right" refers to the right side when vehicle 1 is viewed from the rear to the front.

(Overall composition)
The vehicle 1 illustrated in Fig. 1 is a hybrid vehicle. In detail, as shown in Fig. 1, the vehicle 1 includes an engine 2 and a motor 3 as a driving source (powertrain), and a transmission 4 that changes the speed of the driving force transmitted from at least one of the engine 2 and the motor 3 and transmits it. The engine 2 is accommodated in an engine room that is disposed forward of the passenger compartment. The engine 2 is vertically disposed in the engine room at a position approximately in the center of the vehicle width direction. The motor 3 is disposed behind the engine 2 via a damper 5. The transmission 4 is vertically disposed behind the motor 3.

The engine 2 and motor 3 as the powertrain are positioned at the front of the vehicle in the fore-and-aft direction, but the charger (not shown) for the motor 3 is positioned at the rear of the vehicle in the fore-and-aft direction, so the center of gravity position G1 of the vehicle 1 in the fore-and-aft direction is slightly forward (specifically, near the B-pillar) rather than the middle position of the vehicle 1 in the fore-and-aft direction (see Figure 4).

The vehicle 1 is a vehicle in which at least the left and right rear wheels 7 are drive wheels. More specifically, the vehicle 1 is configured as a four-wheel drive vehicle in which both the left and right front wheels 6 and the left and right rear wheels 7 are drive wheels. The rear of the transmission 4 is a transfer 4a for transmitting the driving force to the front wheels 6 and the rear wheels 7. A front propeller shaft 8 extends forward from the transfer 4a. A rear propeller shaft 9 extends rearward from the transfer 4a. The front propeller shaft 8 is disposed slightly to the right of the center in the vehicle width direction. The rear propeller shaft 9 is disposed approximately in the center in the vehicle width direction. Although details are omitted, the driving force changed by the transmission 4 is transmitted to the front propeller shaft 8 and the rear propeller shaft 9 by the transfer 4a. The front propeller shaft 8 transmits the driving force to the front wheels 6, and the rear propeller shaft 9 transmits the driving force to the rear wheels 7.

As shown in FIG. 2B, the transmission 4 is positioned with at least the rear portion of the vehicle inserted into the floor tunnel 10. More specifically, the transmission 4 is positioned so that it is inclined downward from the front to the rear.

As shown in FIG. 2A, the floor tunnel 10 is formed by a tunnel panel 11. As shown in FIG. 3, the upper end of the tunnel panel 11 is inclined downward from the front to the rear. Therefore, the floor tunnel 10 becomes narrower in the vertical direction toward the rear.

A rear propeller shaft 9 is disposed within the floor tunnel 10. The rear propeller shaft 9 is connected to the transfer 4a via a rubber cup 4b. The rear propeller shaft 9 extends from the position of the rubber cup 4b, slanting downward toward the rear. A universal joint 9a is provided at the midpoint of the rear propeller shaft 9 in the fore-and-aft direction. In the event of a frontal collision, for example, the rear propeller shaft 9 is designed to bend in the vertical and horizontal directions starting from the universal joint 9a.

The rear propeller shaft 9 according to this embodiment is divided in two in the front-rear direction by a universal joint 9a. Specifically, from the front of the vehicle, the rear propeller shaft 9 has a first shaft portion 9b connected to the transmission 4, and a second shaft portion 9c connected to the first shaft portion 9b via the universal joint 9a.

A separate rubber cup is provided in front of the universal joint 9a on the rear propeller shaft 9. A support bracket 9d that supports the rear propeller shaft 9 is provided at the position of the rubber cup. The support bracket 9d has a U-shape that covers the rubber cup from below, and the left and right ends are connected by bolts to the reinforcing upper tunnel rain 12 provided on the tunnel panel 11.

A side tunnel rein 13 extending in the front-rear direction is provided on each of the left and right ends of the tunnel panel 11. Each side tunnel rein 13 is a member for reinforcing the tunnel panel 11. Each side tunnel rein 13 is connected by welding to the inner part of the tunnel panel 11 so as to form a closed cross section between the tunnel panel 11 and the side tunnel rein 13.

A pair of left and right floor panels 30 that constitute the vehicle interior floor are arranged on the left and right sides of the tunnel panel 11. The floor panels 30 extend horizontally in the front-rear and left-right directions. Although not shown in the figure, the right end of the left floor panel 30 is connected to the left end of the tunnel panel 11 by welding. Similarly, the left end of the right floor panel 30 is connected to the right end of the tunnel panel 11 by welding. The left and right floor panels 30 are connected to the left and right by the tunnel panel 11. The connection parts between each floor panel 30 and the tunnel panel 11 are located at the same location as the connection parts between the tunnel panel 11 and the side tunnel rain 13, or are located outside the joint parts in the vehicle width direction.

As shown in FIG. 2B, the left and right toe boards 32 are connected to the front ends of the left and right floor panels 30 by welding, respectively, on the left and right sides. The left and right toe boards 32 extend from the front ends of the left and right floor panels 30 at an upward incline toward the front. The upper ends of the left and right toe boards 32 are joined to the lower end of the dash panel (not shown), which separates the passenger compartment from the engine room. The right end of the left toe board 32 is connected to the left end of the tunnel panel 11 by welding. The left end of the right toe board 32 is connected to the right end of the tunnel panel 11 by welding.

As shown in FIG. 2B, a pair of left and right floor frames (floor side frames) 21 extending in the front-rear direction are connected to the undersides of the left and right floor panels 30 and the undersides of the left and right toe boards 32. The left and right floor frames 21 extend at an angle toward the outside in the vehicle width direction toward the rear so as to be spaced apart from each other in the vehicle width direction, and then extend straight toward the rear so as to be parallel to each other.

As shown in Figures 7 and 8, a pair of left and right side sills 22 extending in the front-rear direction are connected to the outer ends of the left and right floor panels 30 in the vehicle width direction. The left and right side sills 22 are respectively positioned outboard in the vehicle width direction than the left and right floor frames 21. The left side sill 22 is connected to the left end of the left floor panel 30 by welding. The right side sill 22 is connected to the right end of the right floor panel 30 by welding.

As shown in Figures 7 and 8, the left and right floor frames 21 are adjacent to the left and right side sills 22 in the vehicle width direction (only the left floor frame 21 and side sill 22 are shown in the figures). The lower end of the floor frame 21 is positioned higher than the lower end of the side sill 22.

As shown in FIG. 2, the front ends of the left and right floor frames 21 and the front ends of the left and right side sills 22 are connected to each other on the left side and right side by left and right gussets 23, respectively.

As shown in Figures 1 and 2B, in the area behind the transfer 4a, battery units 40L, 40R storing power for driving the motor 3 are arranged separately on the left and right sides of the floor tunnel 10. In particular, the battery units 40L, 40R according to this embodiment are arranged below the vehicle with respect to the floor panels 30 arranged on the left and right sides of the floor tunnel 10, as shown by the dashed lines in Figure 2A.

As shown in FIG. 2, the front ends of the left and right floor frames 21 and the front ends of the left and right side sills 22 are connected to each other on the left side and right side by left and right gussets 23, respectively.

As shown in Figures 1 and 2B, in the area behind the transfer 4a, battery units 40L, 40R storing power for driving the motor 3 are arranged separately on the left and right sides of the floor tunnel 10. In particular, the battery units 40L, 40R according to this embodiment are arranged below the vehicle with respect to the floor panels 30 arranged on the left and right sides of the floor tunnel 10, as shown by the dashed lines in Figure 2A.

Here, the left battery unit 40L is disposed below the passenger seat (seat), and the right battery unit 40R is disposed below the driver's seat (seat). The left and right battery units 40L, 40R are electrically connected to each other by connectors. As shown in FIG. 2A, the right end of the left battery unit 40L and the left end of the right battery unit 40R slightly overlap the floor tunnel 10 when viewed from above or below in the vertical direction.

The left and right battery units 40L, 40R both extend in the vehicle fore-and-aft direction so as to pass through the center of gravity G1 of the vehicle 1. In other words, the center of gravity G1 of the vehicle 1 is located between the front and rear ends of the left and right battery units 40L, 40R in the vehicle fore-and-aft direction (see dashed line L1 in FIG. 4). By arranging them in this manner, the center of gravity G2 of each of the left and right battery units 40L, 40R and the center of gravity G1 of the vehicle 1 are close to each other in the vehicle fore-and-aft direction.

The left and right battery units 40L, 40R both extend in the vehicle fore-and-aft direction so as to pass through the center of gravity G1 of the vehicle 1. More specifically, the center of gravity G1 of the vehicle 1 is configured to be located between the front and rear ends of the left and right battery units 40L, 40R in the vehicle fore-and-aft direction. By arranging them in this manner, the center of gravity G2 of each of the left and right battery units 40L, 40R and the center of gravity G1 of the vehicle 1 are close to each other in the vehicle fore-and-aft direction.

The left and right battery units 40L, 40R both extend in the vehicle width direction toward the side end of the vehicle 1 (side sill 22). The left and right battery units 40L, 40R both extend close to the side end of the vehicle 1. Specifically, the left and right battery units 40L, 40R each face the side sill 22 with the floor frame 21 in between.

2B, an exhaust pipe 28 through which exhaust gas from the engine 2 passes is disposed on the right side of the transmission support member 33. The exhaust pipe 28 extends from the engine 2 toward the floor tunnel 10, bypassing the right side of the transmission 4 and the transmission support member 33, and then extends through the floor tunnel 10 toward the rear. The exhaust pipe 28 has an exhaust purification device 29 on the right side of the transmission support member 33. The exhaust purification device 29 has a horizontally elongated elliptical shape and has an exhaust purification catalyst 29a inside. The exhaust pipe 28 is configured to enter the floor tunnel 10 at the same height as the front part 43R of the right battery unit 40R and the mission support member 33, passing between the front part 43R of the right battery unit 40R and the mission support member 33.

Next, the peripheral configuration of the left battery unit 40L and the right battery unit 40R will be described in detail.

(Configuration of left battery unit 40L)
First, a description will be given of the peripheral configuration of the left battery unit 40L. As shown in Figure 2B and Figures 4 to 6, the left battery unit 40L is box-shaped and has a substantially rectangular shape when viewed from the bottom.

In detail, the left battery unit 40L has a left front portion 43L, a left outer side portion 44L extending in the fore-and-aft direction from the outer end of the left front portion 43L in the vehicle width direction, a left inner side portion 45L extending in the fore-and-aft direction from the inner end of the left front portion 43L in the vehicle width direction, a left upper side portion 46L extending horizontally from the upper end of the left front portion 43L toward the rear of the vehicle, a left lower side portion 47L extending from the lower end of the left front portion 43L and facing the left upper side portion 46L in the up-down direction, and a left rear side portion 48L facing the left front portion 43L in the fore-and-aft direction.

The edges of each surface portion 43L to 48L of the left battery unit 40L are integral with each other. The left front portion 43L is located with the inner portion in the vehicle width direction rearward relative to the outer portion in the vehicle width direction. This allows the left battery unit 40L to be as large as possible while still providing space for placing the transmission support member 33.

The left battery unit 40L according to this embodiment is constructed by fastening a pair of upper and lower case members. In detail, as shown in Figs. 5, 7, and 8, the left battery unit 40L has a first left case 41L and a second left case 42L that are divided in the vertical direction. The first left case 41L is a case member that includes a left upper surface portion 46L and is located relatively higher. The second left case 42L is a case member that includes a left lower surface portion 47L and is located relatively lower.

The first left case 41L and the second left case 42L are each formed in a box shape that opens toward the upper or lower side of the vehicle, and have flanges 41aL, 42aL provided along the periphery of the opening. In more detail, the first left case 41L has a flange 41aL at its lower end that extends along the edge, and the second left case 42L has a flange 42aL at its upper end that extends along the edge.

The first left case 41L and the second left case 42L as case members can be fastened to each other by inserting bolts (fasteners) into the flanges 41aL and 42aL. In more detail, the first left case 41L and the second left case 42L are connected by bolts with the flanges 41aL and 42aL butted against each other in the vertical direction. A seal member is disposed at the abutting portion between the first left case 41L and the second left case 42L.

The left battery unit 40L is connected to the vehicle body structural components via multiple mounting brackets 51L, 52L. In this embodiment, the mounting brackets 51L, 52L are attached to the left outer side surface 44L of the left battery unit 40L, which faces the outside (left side) in the vehicle width direction, and the left inner side surface 45L of the left battery unit 40L, which faces the inside (right side) in the vehicle width direction.

The left battery unit 40L is connected to the vehicle body structural components via multiple mounting brackets 51L, 52L. In this embodiment, the mounting brackets 51L, 52L are attached to the left outer side surface 44L of the left battery unit 40L, which faces the outside (left side) in the vehicle width direction, and the left inner side surface 45L of the left battery unit 40L, which faces the inside (right side) in the vehicle width direction.

Specifically, a left outer bracket 52L serving as a mounting bracket is attached to the left outer side surface portion 44L of the left battery unit 40L (see Figures 1, 2B, and 4-5). This left outer bracket 52L connects the left battery unit 40L to the floor panel 30. Similarly, a left inner bracket 51L serving as a mounting bracket is attached to the left inner side surface portion 45L of the left battery unit 40L (see Figures 1-6). This left inner bracket 51L connects the left battery unit 40L to the tunnel panel 11.

The left inner brackets 51L are arranged in a multiple number at intervals in the vehicle fore-and-aft direction. Here, the left inner bracket 51L according to this embodiment comprises a first left inner bracket 60L and a second left inner bracket 70L that is arranged alongside the first left inner bracket 60L along the vehicle fore-and-aft direction and is located further rearward on the vehicle than the first left inner bracket 60L.

Of these, the first left inner bracket 60L is disposed closer to the front of the vehicle than the universal joint 9a, and is disposed closer to the transmission 4 than the second left inner bracket 70L. More specifically, the first left inner bracket 60L is disposed closer to the center of gravity G2 of the left battery unit 40L in the vehicle longitudinal direction than the second left inner bracket 70L. In the example shown in FIG. 2, the first left inner bracket 60L is configured to cover the front portion of the left inner side surface portion 45L from the inside in the vehicle width direction.

The first left inner bracket 60L functions not only as a mounting bracket for connecting the left battery unit 40L to vehicle body components, but also as a protector that covers the left inner side surface portion 45L from the inside in the vehicle width direction. The first left inner bracket 60L is a member that prevents the transfer 4a from contacting the left inner side surface portion 45L of the left battery unit 40L when the transmission 4 enters the floor tunnel 10 together with the transfer 4a during a frontal collision. The left inner protector 70L is made of, for example, cast iron.

The first left inner bracket 60L functions as a mounting bracket for connecting the left battery unit 40L to vehicle body components, and also functions as a protector that covers the left inner side surface portion 45L from the inside in the vehicle width direction. The first left inner bracket 60L is a member that prevents the transfer 4a from contacting the left inner side surface portion 45L of the left battery unit 40L when the transmission 4 enters the floor tunnel 10 together with the transfer 4a during a frontal collision. The left inner protector 70L is made of, for example, cast iron.

The second left inner bracket 70L is disposed rearward of the universal joint 9a. As shown in FIG. 3, the second left inner bracket 70L is closer to the universal joint 9a than the first left inner bracket 60L in the vehicle front-rear direction.

The second left inner bracket 70L is configured as a plate-shaped protector that covers the portion of the left inner side surface 45L that is located rearward of the universal joint 9a. The second left inner bracket 70L functions when the transmission 4 together with the transfer 4a enters the floor tunnel 10 during a frontal collision and is bent left and right starting from the universal joint 9a. In this case, the second left inner bracket 70L exerts its function as a member for suppressing contact between the universal joint 9a and the left inner side surface 45L of the left battery unit 40L. The left inner protector 70L is configured, for example, from a high-tensile steel plate part.

The left outer bracket 52L is arranged in a multiple number at intervals in the vehicle fore-and-aft direction. Here, the left outer bracket 52L according to this embodiment includes at least a first left outer bracket 80L that extends along the vehicle fore-and-aft direction.

The first left outer bracket 80L extends along the vehicle longitudinal direction so as to pass through the center of gravity G2 of the left battery unit 40L in the vehicle longitudinal direction. In particular, as shown in FIG. 1, the front end of the first left outer bracket 80L is disposed on the vehicle front side of the center of gravity G2 of the left battery unit 40L, and the rear end of the first left outer bracket 80L is disposed on the vehicle rear side of the center of gravity G2 of the left battery unit 40L (see the dashed line L2 in FIG. 4). In the example shown in FIG. 2, the first left outer bracket 80L is attached to the left outer side surface portion 44L at a midpoint in the longitudinal direction.

Specifically, the first left outer bracket 80L is positioned further forward in the vehicle fore-and-aft direction than the other left outer brackets in the multiple left outer brackets 52L. The multiple left outer brackets 52L according to this embodiment include the first left outer bracket 80L described above and a second left outer bracket 90L positioned further rearward in the vehicle fore-and-aft direction than the first left outer bracket 80L.

As shown in Figures 4 and 5, the first left outer bracket 80L is longer in the vehicle front-rear direction than the second left outer bracket 90L. In addition, the first left outer bracket 80L is formed from an extrusion material, and the second left outer bracket 90L is formed from a press material.

In this embodiment, an energy absorbing member 85 is provided integrally only to the first left outer bracket 80L among the multiple left outer brackets 52L (see FIG. 8). This energy absorbing member 85 defines a closed cross section in a cross section perpendicular to the vehicle front-rear direction. The energy absorbing member 85 is provided integrally from the front end to the rear end of the first left outer bracket 80L.

The vehicle 1 according to this embodiment also includes a pipe 24 that extends in the front-rear direction of the vehicle. Fluid flows through this pipe 24 to cool the charger located at the rear of the vehicle. In this embodiment, the pipe 24 is arranged below the left outer bracket 52L.

The configuration of the first left outer bracket 80L is described in detail below.

As shown in Figures 7-8 and 10-12, the first left outer bracket 80L has a side plate portion 81 that is fastened to the second left case 42L, a top plate portion 82 that serves as a mounting plate that is connected to the floor panel 30 via the floor frame 21, a bottom plate portion 83 that extends from the top plate portion 82 toward the outside in the vehicle width direction, and a connecting plate portion 84 that connects the top plate portion 82 and the bottom plate portion 83. These elements are formed integrally with each other.

The side plate portion 81 is formed in a rectangular plate shape with short sides extending along the vehicle height direction and long sides extending along the vehicle longitudinal direction. The lower half of the side plate portion 81 is provided with a plurality of through holes along the vehicle longitudinal direction. The first left outer bracket 80L can be attached to the second left case 42L by inserting bolts 108 into the through holes and fastening each bolt 109 to the left upper surface portion 46L of the second left case 42L. The upper half of the side plate portion 81, together with the top plate portion 82, bottom plate portion 83, and connection plate portion 84, constitutes an energy absorbing member 85 having a hollow closed cross section.

The top plate portion 82 is formed in a plate shape that protrudes outward in the vehicle width direction from the upper end of the side plate portion 81 and extends in the vehicle front-rear direction. The top plate portion 82, together with other portions of the first left outer bracket 80L (specifically, the side plate portion 81, the bottom plate portion 83, and the connecting plate portion 84), constitutes an energy absorbing member 85.

Specifically, the top plate portion 82 is formed in a rectangular plate shape having short sides extending along the vehicle width direction and long sides extending along the vehicle front-rear direction. The top plate portion 82 is provided with a plurality of through holes 82a aligned along the vehicle front-rear direction. A bolt 109 can be inserted into each through hole 82a. With the bolt 109 inserted into each through hole 82a, the top plate portion 82 is fastened to the lower surface (lower end) of the left floor frame 21, so that the first left outer bracket 80L is connected to the floor panel 30 via the floor frame 21. Each through hole 82a also contributes to promoting the crushing deformation (particularly the crushing deformation in the vehicle width direction) of the energy absorbing member 85 during a side collision.

The bottom plate portion 83 is formed in a plate shape that protrudes outward in the vehicle width direction from the middle position in the vehicle height direction of the side plate portion 81 and extends in the vehicle front-rear direction. The bottom plate portion 83, together with other portions of the first left outer bracket 80L (specifically, the upper half of the side plate portion 81, the top plate portion 82, and the connecting plate portion 84), constitutes an energy absorbing member 85.

Specifically, the bottom plate portion 83 is formed in a rectangular plate shape having short sides extending along the vehicle width direction and long sides extending along the vehicle front-rear direction. The bottom plate portion 83 faces the top plate portion 82 in the vehicle height direction. The bottom plate portion 83 also protrudes outward in the vehicle width direction beyond the top plate portion 82. When the first left outer bracket 80L is fastened to the floor frame 21, the bottom plate portion 83 is arranged to be at the same height position as the lower end of the side sill 22 in the vehicle height direction.

The bottom plate portion 83 is provided with a number of through holes 83a aligned along the vehicle longitudinal direction. As shown by comparing FIG. 10 with FIG. 11, the plurality of through holes 83a in the bottom plate portion 83 are arranged at the same positions in the vehicle longitudinal direction as the plurality of through holes 82a in the top plate portion 82. In other words, in this embodiment, the former through holes 83a and the latter through holes 82a are set to the same number. Each through hole 83a assists in the insertion of the bolt 109 for fastening the top plate portion 82. Each through hole 83a also contributes to promoting the crushing deformation (particularly the crushing deformation in the vehicle width direction) of the energy absorbing member 85 during a side collision.

The connecting plate portion 84 is formed in a plate shape that connects the tip portion (the end portion on the outer side in the vehicle width direction) of the top plate portion 82 and the tip portion (the end portion on the outer side in the vehicle width direction) of the bottom plate portion 83. The connecting plate portion 84, together with other portions of the first left outer bracket 80L (specifically, the upper half of the side plate portion 81, the top plate portion 82, and the bottom plate portion 83), constitutes an energy absorbing member 85.

Specifically, the connection plate portion 84 is formed in a plate shape that extends at an angle relative to the vehicle width direction and along the vehicle front-rear direction. The connection plate portion 84 extends downward from the tip portion (the outer end portion in the vehicle width direction) of the top plate portion 82 substantially parallel to the vehicle height direction, and then reaches the tip portion (the outer end portion in the vehicle width direction) of the bottom plate portion 83 while being slightly inclined relative to the vehicle width direction. As shown in FIG. 8, the connection plate portion 84 according to this embodiment extends from the inner surface portion of the side sill 22 so as to surround the underside portion.

When viewed in a vertical cross section in the vehicle longitudinal direction, the energy absorbing member 85 has a closed cross section defined by the upper half of the side plate portion 81, the top plate portion 82, the bottom plate portion 83, and the connecting plate portion 84. The closed cross section of the energy absorbing member 85 has a form that reflects the shape and arrangement of each of the plate portions 81 to 84.

Specifically, the lower end of the energy absorbing member 85 formed by the bottom plate portion 83 is disposed at the same height as the lower end of the side sill 22 in the vehicle height direction. In addition, the portion of the energy absorbing member 85 located on the outer side in the vehicle width direction (more specifically, the portion formed by the top plate portion 82 and the bottom plate portion 83) is tapered compared to the portion located on the inner side in the vehicle width direction (more specifically, the portion formed by the connection plate portion 84 and the bottom plate portion 83).

The aforementioned piping 24 is arranged inward in the vehicle width direction from the vehicle width end of the energy absorbing member 85 (the vehicle width outer end of the bottom plate portion 83), and is arranged below the top plate portion 82 in the vehicle height direction.

On the other hand, the second left outer bracket 90L is attached to the rear end position of the left outer side surface portion 44L. Specifically, the second left outer bracket 90L has a first fastening portion 91 that is fastened to the second left case 42L and a second fastening portion 92 that is connected to the underside of the left floor frame 21. As shown in FIG. 9, the first fastening portion 91 can be attached to the left battery unit 40L by inserting a bolt 110 into the first fastening portion 91. Also, the second fastening portion 92 can be fastened to the underside of the left floor frame 21 by inserting a bolt 111 into the second fastening portion 92. Through these fastenings, the rear end of the left battery unit 40L is connected to the floor frame 21 via the second left outer bracket.

(Configuration of right battery unit 40R)
Next, the peripheral configuration of the right-side battery unit 40R will be described. Although the peripheral configuration of the right-side battery unit 40R differs from that of the left-side battery unit 40L in detailed shape, the basic configuration is configured to be symmetrical to the left-side battery unit 40L. Therefore, only the parts of the peripheral configuration of the right-side battery unit 40R that differ from the peripheral configuration of the left-side battery unit 40L will be described in detail, and the parts that are common to the peripheral configuration of the left-side battery unit 40L will be omitted from detailed description as appropriate.

4 and 6, the right battery unit 40R is box-shaped and has a substantially rectangular shape when viewed from the bottom. In detail, the right battery unit 40R has a right front portion 43R, a right outer side portion 44R extending in the front-rear direction from the outer end of the right front portion 43R in the vehicle width direction, a right inner side portion 45R extending in the front-rear direction from the inner end of the right front portion 43R in the vehicle width direction, a right upper side portion 46R extending horizontally from the upper end of the right front portion 43R toward the rear of the vehicle, a right lower side portion 47R extending from the lower end of the right front portion 43R and facing the right upper side portion 46R in the up-down direction, and a right rear side portion 48R facing the right front portion 43R in the front-rear direction.

The edges of the faces 43R to 48R of the right battery unit 40R are integral with each other. The right front face 43R has an inner portion in the vehicle width direction that is located rearward of the outer portion in the vehicle width direction.

The right-side battery unit 40R according to this embodiment is constructed by fastening a pair of upper and lower case members. In detail, as shown in FIG. 5, the right-side battery unit 40R has a first right-side case 41R and a second right-side case 42R that are divided in the vertical direction. The first right-side case 41R is a case member that includes a right-side upper surface portion 46R and is located relatively higher. The second right-side case 42R is a case member that includes a right-side lower surface portion 47R and is located relatively lower.

The first right case 41R and the second right case 42R are each formed in a box shape that opens toward the upper or lower side of the vehicle, and have a flange (not shown) provided along the periphery of the opening. In detail, the first right case 41R has a flange that extends along the edge at its lower end, and the second right case 42R has a flange that extends along the edge at its upper end. By inserting a bolt (fastener) into the flange, the first right case 41R and the second right case 42R as case members can be fastened to each other.

The right battery unit 40R is connected to the vehicle body structural components via multiple mounting brackets 51R, 52R. In this embodiment, the mounting brackets 51R, 52R are attached to the right outer side surface portion 44R of the right battery unit 40R, which faces the outside (right side) in the vehicle width direction, and the right inner side surface portion 45R of the right battery unit 40R, which faces the inside (left side) in the vehicle width direction.

The right battery unit 40R is connected to the vehicle body structural components via multiple mounting brackets 51R, 52R. In this embodiment, the mounting brackets 51R, 52R are attached to the right outer side surface portion 44R of the right battery unit 40R, which faces the outside (right side) in the vehicle width direction, and the right inner side surface portion 45R of the right battery unit 40R, which faces the inside (left side) in the vehicle width direction.

Specifically, a right outer bracket 52R serving as a mounting bracket is attached to the right outer side surface portion 44R of the right battery unit 40R (see Figures 1, 2B, and 4-5). This right outer bracket 52R connects the right battery unit 40R to the floor panel 30. Similarly, a right inner bracket 51R serving as a mounting bracket is attached to the right inner side surface portion 45R of the right battery unit 40R (see Figures 1-6). This right inner bracket 51R connects the right battery unit 40R to the tunnel panel 11.

The right inner bracket 51R is arranged in a multiple number at intervals in the vehicle fore-and-aft direction. Here, the right inner bracket 51R according to this embodiment comprises a first right inner bracket 60R and a second right inner bracket 70R arranged alongside the first right inner bracket 60R along the vehicle fore-and-aft direction and positioned further rearward on the vehicle than the first right inner bracket 60R. The right inner bracket 51R has a configuration that is the left-right inverted version of the left inner bracket 51L, and performs the same function as the left inner bracket 51L.

On the other hand, multiple right outer brackets 52R are arranged at intervals in the vehicle fore-and-aft direction. Here, the right outer bracket 52R according to this embodiment includes at least a first right outer bracket 80R that extends along the vehicle fore-and-aft direction.

The first right outer bracket 80R extends along the vehicle front-rear direction so as to pass through the center of gravity G2 of the right battery unit 40R in the vehicle front-rear direction. In more detail, as shown in FIG. 1, the front end of the first right outer bracket 80R is disposed on the vehicle front side of the center of gravity G2 of the right battery unit 40R, and the rear end of the first right outer bracket 80R is disposed on the vehicle rear side of the center of gravity G2 of the right battery unit 40R. In the example shown in FIG. 2, the first right outer bracket 80R is attached to the right outer surface portion 44R at a midpoint in the front-rear direction.

Specifically, the first right outer bracket 80R is positioned further forward in the vehicle fore-and-aft direction than the other right outer brackets in the multiple right outer brackets 52R. The multiple right outer brackets 52R according to this embodiment include the first right outer bracket 80R described above and a second right outer bracket 90R positioned further rearward in the vehicle fore-and-aft direction than the first right outer bracket 80R.

As shown in Figures 4 and 5, the first right outer bracket 80R is longer in the vehicle front-rear direction than the second right outer bracket 90R. In addition, the first right outer bracket 80R is made of extrusion material, and the second right outer bracket 90R is made of press material.

In this embodiment, an energy absorbing member is provided integrally only on the first right outer bracket 80R among the multiple right outer brackets 52R. The configuration of the energy absorbing member in the first right outer bracket 80R and the first right outer bracket 80R is equivalent to the configuration of the energy absorbing member 85 in the first left outer bracket 80L and the first left outer bracket 80L, reversed from left to right. The same is true for the second right outer bracket 90R.

(Deformation of energy absorbing members during side collisions)
For example, when a side impact occurs from the left side of the vehicle 1, a load acts on the side sill 22 from the side. This load causes the side sill 22 to deform so as to be crushed in the vehicle width direction, and to come into contact with the energy absorbing member 85. At that time, the tapered lower end of the energy absorbing member 85 protrudes outward in the vehicle width direction more than the upper end, and therefore comes into contact with the side sill 22 at an earlier timing than the upper end. Due to this contact, the tapered tip of the energy absorbing member 85 is crushed in the vehicle width direction and at the same time, is deformed so as to expand in the vehicle height direction. This deformation propagates to the base end side portion (the inner portion of the top plate portion 82 and the bottom plate portion 83), and the entire energy absorbing member 85 is deformed so as to be crushed. Here, by providing the through holes 82a, 83a in the top plate portion 82 and the bottom plate portion 83, bending of the energy absorbing member 85 starting from the base end side portion is suppressed, and the entire energy absorbing member 85 can be crushed well. By crushing the entire energy absorbing member 85, the load applied to the left battery unit 40L can be alleviated.

(Protection of the battery unit during a side collision)
Although a side collision from the left side of the vehicle will be described below, the following description is also applicable to a side collision from the right side of the vehicle.

As described above, according to this embodiment, the center of gravity G1 of the vehicle 1 is located between the front end and rear end of the left battery unit 40L in the vehicle longitudinal direction. In this case, the center of gravity G2 of the left battery unit 40L and the center of gravity G1 of the vehicle 1 are close to each other. In addition, the center of gravity G2 of the left battery unit 40L is located between the front end and rear end of the first left outer bracket 80L as the first mounting bracket in the vehicle longitudinal direction. In this case, the first left outer bracket 80L is located so as to include the center of gravity G2 of the left battery unit 40L. The first left outer bracket 80L is required to have relatively high safety performance compared to other mounting brackets.

As shown in Figures 4 and 7-8, of the multiple mounting brackets, an energy absorbing member 85 is provided only on the first left outer bracket 80L, which is close to the center of gravity G2 of the left battery unit 40L, and therefore the center of gravity G1 of the vehicle 1. While high safety performance is ensured in the first left outer bracket 80L, the weight and manufacturing costs can be reduced by the amount that the energy absorbing member 85 is not provided in the other mounting bracket, the second left outer bracket 90L. This makes it possible to reduce weight and manufacturing costs while ensuring the safety performance of the vehicle 1.

As shown in FIG. 1 etc., the power train, including the engine 2 and motor 3, is located at the front of the vehicle. In this case, the center of gravity G1 of the vehicle 1, and therefore the center of gravity G2 of the left battery unit 40L adjacent thereto, are located at the front in the fore-and-aft direction of the vehicle, as shown in FIG. 4. Therefore, of the multiple mounting brackets, the energy absorbing member 85 is provided only on the first left outer bracket 80L, which is located forward of the second left outer bracket 90L. By limiting the mounting brackets on which the energy absorbing member 85 should be provided, the multiple mounting brackets as a whole can be configured more compactly.

As shown in FIG. 4, by setting the dimension of the first left outer bracket 80L to be long, it is possible to set the dimension of the energy absorbing member 85 to be longer. This is advantageous in ensuring the safety performance of the vehicle 1. On the other hand, by setting the dimension of the second left outer bracket 90L to be short, it is advantageous in reducing weight and manufacturing costs.

In addition, by forming the first left outer bracket 80L from an extruded material and the second left outer bracket 90L from a pressed material, it is advantageous for the first left outer bracket 80L to be integrally provided with the energy absorbing member 85, while it is advantageous for the second left outer bracket 90L to be lightweight.

In addition, as shown in Figures 7 and 8, the energy absorbing member 85 can be covered and hidden from the side by the side sill 22. This is advantageous in terms of improving the design of the vehicle 1.

As described with reference to Figures 10 and 11, each part constituting the first left outer bracket 80L constitutes the energy absorbing member 85. This improves the performance of the energy absorbing member 85, which is advantageous in ensuring the safety performance of the vehicle 1.

In addition, as shown in Figures 7 and 8, the pipe 24 can be protected from above by the energy absorbing member 85. This is advantageous in ensuring the safety performance of the vehicle 1.

In addition, as shown in Figures 10 and 11, by providing through holes 82a, 83a in the top plate portion 82 and the bottom plate portion 83, it is possible to crush the entire energy absorbing member 85 well. This makes it possible to improve the performance of the energy absorbing member 85.

In addition, as shown in Figures 7 and 8, the portion of the energy absorbing member 85 located on the outer side in the vehicle width direction (more specifically, the portion formed by the top plate portion 82 and the bottom plate portion 83) is tapered compared to the portion located on the inner side in the vehicle width direction (more specifically, the portion formed by the connecting plate portion 84 and the bottom plate portion 83), which allows the energy absorbing member 85 to function at an earlier timing in the event of a side collision of the vehicle. This is advantageous in improving the safety of the vehicle 1.

Other Embodiments
The technology disclosed herein is not limited to the above-described embodiment, and may be substituted without departing from the spirit and scope of the claims.

For example, in the above embodiment, the vehicle 1 was a four-wheel drive vehicle. However, the present invention is not limited to this, and may be, for example, a front-wheel drive (FR) type vehicle. If the vehicle 1 is a front-wheel drive type vehicle, the transfer 4a and the front propeller shaft 8 are omitted. The vehicle 1 may also be an electric vehicle that does not have an engine 2 and has only a motor 3 as a drive source.

The above-described embodiments are merely examples and should not be interpreted as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and variations that fall within the scope of equivalence of the claims are within the scope of the present disclosure.

1 Vehicle 2 Engine (powertrain)
3 Motor (power train)
4. Transmission
4a Transfer (transmission)
7 Rear wheels 9 Rear propeller shaft (propeller shaft)
10 Floor tunnel 11 Tunnel panel 12 Floor panel 21 Floor frame (floor side frame)
22 Side sill 24 Pipe 30 Floor panel 40L Left side battery unit (battery unit)
40R Right side battery unit (battery unit)
41L First left case (case member)
41R First right case (case member)
41aL Flange 42L Second left case (case member)
42R Second right case (case member)
42aL Flange 44L Left outer surface portion 44R Right outer surface portion 52L Left outer bracket (multiple mounting brackets)
52R Right side outer bracket (multiple mounting brackets)
80L First left outer bracket (first mounting bracket)
80R First right outer bracket (first mounting bracket)
82 Top plate (mounting plate)
85 Energy absorbing member 90L Second left outer bracket (another mounting bracket)
90R Second right outer bracket (other mounting bracket)
G1: Position of center of gravity of vehicle in the longitudinal direction of the vehicle G2: Position of center of gravity of battery unit in the longitudinal direction of the vehicle

Claims (6)

1. A vehicle undercarriage, comprising:
a battery unit that is disposed under a floor panel and extends toward a side end of the vehicle in a vehicle width direction and passes through a center of gravity of the vehicle in a vehicle front-rear direction;
a mounting bracket attached to an outer surface portion of the battery unit facing outward in a vehicle width direction and connected to the floor panel;
The mounting brackets are arranged at intervals in the front-rear direction of the vehicle,
The mounting bracket includes at least a first mounting bracket extending along a vehicle front-rear direction so as to pass through a center of gravity of the battery unit in the vehicle front-rear direction,
An energy absorbing member is integrally provided only on the first mounting bracket among the mounting brackets ,
the first mounting bracket is fastened to a lower end of the floor side frame so as to be connected to the floor panel via the floor side frame;
The floor side frame is adjacent to the side sill in the vehicle width direction,
In a vehicle height direction, a lower end portion of the floor side frame is disposed at a position higher than a lower end portion of the side sill,
In the vehicle height direction, a lower end of the energy absorbing member is disposed at the same height as a lower end of the side sill.
1. A vehicle undercarriage comprising: The vehicle underbody structure according to claim 1,
a power train of the vehicle is disposed at a front side in a vehicle front-rear direction;
11. A vehicle underbody structure, comprising: a first mounting bracket disposed forward in a longitudinal direction of the vehicle relative to the other mounting brackets of the mounting brackets. The vehicle underbody structure according to claim 2,
A vehicle underbody structure, wherein the first mounting bracket has a longer dimension in a front-to-rear direction of the vehicle than the other mounting brackets. The vehicle underbody structure according to any one of claims 1 to 3,
Of the mounting brackets,
the first mounting bracket is formed of an extrusion material;
13. A vehicle underbody structure, comprising: a first mounting bracket and a second mounting bracket; The vehicle underbody structure according to claim 1 ,
the first mounting bracket has a mounting plate fastened to the floor side frame,
The mounting plate is formed in a plate shape extending in the front-rear direction of the vehicle,
The mounting plate, together with other portions of the first mounting bracket, constitutes the energy absorbing member having a hollow closed cross section. The vehicle underbody structure according to claim 5 ,
The vehicle includes a pipe extending in a front-rear direction of the vehicle,
A vehicle underbody structure, characterized in that the piping is positioned inside the vehicle width direction tip of the energy absorbing member and is positioned below the mounting plate in the vehicle height direction.

Images