JP6996358B2 - Vehicle undercarriage - Google Patents

Description

The present invention relates to a vehicle lower structure.

Patent Document 1 discloses a structure in which a battery module is arranged inside a center console portion.

JP-A-2017-216058

In Patent Document 1, the battery module is cooled by blowing air from the air conditioner to the inside of the battery pack housing.

By the way, in a vehicle such as an electric vehicle in which a storage battery is arranged under the floor of the vehicle, an exhaust pipe is not required. Therefore, if the undercover is formed in a flat shape, it is advantageous from the viewpoint of aerodynamic characteristics. On the other hand, there is no escape place for the running wind sent from the front part of the vehicle to the storage battery, which may cause resistance during running.

In consideration of the above facts, an object of the present invention is to obtain a vehicle lower structure capable of reducing air resistance during traveling in a vehicle in which a storage battery is arranged under the floor.

The vehicle lower structure according to the present invention according to claim 1 covers a storage battery arranged under the floor of the vehicle and supplying power to a motor for driving the vehicle, and covers the storage battery from the lower side of the vehicle, and the storage battery and the vehicle up and down. An undercover configured to include a flat bottom wall facing in the direction, a side wall extending from both ends of the bottom wall in the vehicle width direction toward the upper side of the vehicle, and the storage battery on the outside in the vehicle width direction. It is formed on the side wall of the undercover and has a slit for discharging the wind sent from the front part of the vehicle to the storage battery side to the outside of the vehicle.

In the vehicle lower structure according to the present invention according to claim 1, a storage battery is arranged under the floor of the vehicle. Then, the vehicle is driven by supplying electric power from the storage battery to the motor. Further, the storage battery is covered from the lower side of the vehicle by an undercover, and the undercover has a flat bottom wall facing the storage battery in the vertical direction of the vehicle and the upper side of the vehicle from both ends of the bottom wall in the vehicle width direction. It is configured to include a side wall extending to. In this way, by making the bottom wall of the undercover flat, it is possible to regulate the air flow between the road surface and the undercover as compared with the configuration where the bottom wall of the undercover is uneven, and aerodynamics. The characteristics can be improved.

Further, a slit is formed in the side wall of the undercover, and the wind sent from the front part of the vehicle to the storage battery side is discharged to the outside of the vehicle by this slit. As a result, it is possible to prevent the running wind from disappearing around the storage battery.
In the vehicle lower structure according to the second aspect of the present invention, in claim 1, a front undercover that covers the power unit chamber from the lower side of the vehicle is provided in front of the vehicle in front of the undercover, and the undercover is provided. A gap is provided between the front undercover and the front undercover.

As described above, according to the vehicle lower structure according to the present invention, there is an excellent effect that the air resistance during traveling can be reduced in the vehicle in which the storage battery is arranged under the floor.

It is a side sectional view of the vehicle to which the vehicle lower structure according to the embodiment is applied. It is an enlarged cross-sectional view which shows the state cut by line 2-2 of FIG. 1 in an enlarged manner. It is a perspective view which looked at the undercover which concerns on embodiment from the lower surface side of a vehicle.

Hereinafter, the vehicle lower structure according to the embodiment will be described with reference to the drawings. The arrow FR appropriately shown in each figure indicates the front side of the vehicle, the arrow UP indicates the upper side of the vehicle, and the arrow RH indicates the right side of the vehicle. In the following description, when the front-rear, up-down, and left-right directions are used without special mention, the front-rear direction of the vehicle front-rear direction, the up-down direction of the vehicle up-down direction, and the left-right direction when facing the traveling direction are used.

As shown in FIG. 1, a power unit room 16 partitioned from a vehicle room 14 by a dash panel 12 is provided in a vehicle front portion of a vehicle 10 to which the vehicle lower structure according to the present embodiment is applied. The power unit chamber 16 is provided with a front side member 18 extending in the front-rear direction of the vehicle.

A pair of front side members 18 are provided on the left and right sides, each of which has a closed cross-sectional structure to form the skeleton of the vehicle 10 (in FIG. 1, only the front side member 18 on the right side of the vehicle is shown). The front end portion of the front side member 18 is joined to the front bumper reinforcement 20 extending in the vehicle width direction, and the rear end portion of the front side member 18 is joined to the dash panel 12.

A front bumper cover 29 is provided on the front side of the vehicle with respect to the front bumper information 20, and an opening 29A is formed in the front bumper cover 29. Then, the traveling wind or the like is taken into the power unit chamber 16 from the opening 29A.

A motor 22 is arranged below the front side member 18 of the vehicle, and the front wheels 24 are rotated by driving the motor 22. That is, in the present embodiment, it is a so-called electric vehicle in which the vehicle 10 is driven by the motor 22. Here, the motor 22 is supported by the subframe 23 via a motor mount (not shown) arranged at the lower part of the vehicle.

An inverter 26 is provided above the front side member 18 of the vehicle, and the inverter 26 modulates the electric power of the battery 54 as a storage battery, which will be described later, to generate a voltage applied to the motor 22. Further, a charger (not shown) is provided adjacent to the inverter 26.

A heat exchanger 28 is fixed to the front portion of the front side member 18 by a frame (not shown), and a fan 30 is attached to the rear side of the vehicle of the heat exchanger 28. The heat exchanger 28 is a device for exchanging heat with the cooling water circulating between the motor 22 and rotating the fan 30 to blow air from the opening 29A of the front bumper cover 29 to the heat exchanger 28. The cooling water is cooled by letting it cool.

Here, a front undercover 32 is provided at the lower part of the power unit chamber 16. The front undercover 32 is formed in a substantially flat plate shape with the vertical direction of the vehicle as the plate thickness direction, and the power unit chamber 16 is covered from the lower side of the vehicle by attaching the front undercover 32 to the vehicle body.

A floor panel 34 constituting a floor surface is provided in the vehicle interior 14. The floor panel 34 is formed in a substantially flat plate shape with the vertical direction of the vehicle as the plate thickness direction, and as shown in FIG. 2, the end portion of the floor panel 34 in the vehicle width direction is bent toward the upper side of the vehicle to form the rocker 36. It is joined.

The rocker 36 extends in the front-rear direction of the vehicle and has a closed cross-sectional structure to form the skeleton of the vehicle 10. Further, the rocker 36 is configured to include a rocker inner panel 38 inside in the vehicle width direction and a rocker outer panel 40 outside in the vehicle width direction. The rocker inner panel 38 is formed in a substantially hat-shaped cross section open to the outside in the vehicle width direction, and the rocker outer panel 40 is formed in a substantially hat-like cross section open to the inside in the vehicle width direction. The upper flange 38A of the rocker inner panel 38 and the upper flange 40A of the rocker outer panel 40 are joined in a superposed state. Further, the lower flange 38B of the rocker inner panel 38 and the lower flange 40B of the rocker outer panel 40 are joined in a superposed state.

A resin rocker molding 42 is provided along the rocker 36 on the outside of the rocker outer panel 40 in the vehicle width direction, and the rocker 36 is covered from the outside in the vehicle width direction by the rocker molding 42.

Here, a battery module 44 is arranged on the lower side (under the floor) of the floor panel 34, and the battery module 44 includes a module case 46 and a battery 54.

The module case 46 includes an upper panel 48, a lower panel 50, and a side wall portion 52, and the upper panel 48 is arranged on the vehicle upper side of the battery 54. Further, the upper panel 48 is formed in a substantially plate shape with the vertical direction of the vehicle as the plate thickness direction, and both ends of the upper panel 48 in the vehicle width direction extend beyond the battery 54 to the outside in the vehicle width direction. The portion of the upper panel 48 outside the vehicle width direction from the battery 54 is located on the lower side of the vehicle with respect to the general portion, and is referred to as the upper side flange 48A. Although only the upper flange 48A on the right side of the vehicle is shown in FIG. 2, a similar upper flange is provided on the left side of the vehicle.

The lower panel 50 is arranged on the lower side of the vehicle of the battery 54, and the battery 54 is supported from the lower side of the vehicle by the lower panel 50. Further, the lower panel 50 is formed in a substantially plate shape with the vertical direction of the vehicle as the plate thickness direction, and both ends of the lower panel 50 in the vehicle width direction extend beyond the battery 54 to the outside in the vehicle width direction. The portion of the lower panel 50 outside the vehicle width direction from the battery 54 is located on the upper side of the vehicle with respect to the general portion, and is referred to as the lower side flange 50A. Although only the upper flange 48A on the right side of the vehicle is shown in FIG. 2, a similar upper flange is provided on the left side of the vehicle.

A side wall portion 52 is provided between the upper panel 48 and the lower panel 50. The side wall portion 52 is a metal member having a closed cross-sectional structure formed by extrusion molding or the like, and is formed in the shape of a "sun" when viewed from the front-rear direction of the vehicle. The upper flange 48A of the upper panel 48 is overlapped and joined to the upper surface 52A of the side wall portion 52. On the other hand, the lower side flange 50A of the lower panel 50 is overlapped and joined to the lower surface 52B of the side wall portion 52. Further, a partition portion 52C is provided between the upper surface 52A and the lower surface 52B, and the structure is such that the impact resistance performance of the side wall portion 52 against a side collision is enhanced. A side wall portion similar to the side wall portion 52 is also provided on the left side of the vehicle.

A battery 54 is housed inside the module case 46. The battery 54 includes a plurality of cells, and the battery 54 stores electric power for supplying the motor 22.

Here, on the lower side of the vehicle of the battery module 44, a center undercover 56 that covers the battery module 44 from the lower side of the vehicle is provided. As shown in FIG. 1, the center undercover 56 is formed in a substantially flat plate shape like the front undercover 32, and is provided with a gap on the rear side of the front undercover 32. In addition, a configuration may be configured in which a gap is not provided between the front undercover 32 and the center undercover 56.

As shown in FIGS. 2 and 3, the center undercover 56 includes a bottom wall 56A and a side wall 56B. The bottom wall 56A is arranged so as to face the battery 54 (battery module 44) in the vertical direction of the vehicle and is formed in a substantially planar shape, and extends in the vehicle width direction and the vehicle front-rear direction with the vehicle vertical direction as the plate thickness direction. Has been done.

The side wall 56B extends from both ends of the bottom wall 56A in the vehicle width direction toward the upper side of the vehicle. More specifically, the side wall 56B extends diagonally from both ends of the bottom wall 56A in the vehicle width direction to the upper side of the vehicle and the outer side in the vehicle width direction, and the upper end portion of the side wall 56B is rockered by a fixing means (not shown). It is fixed at 36.

Here, a plurality of slits 58 are formed on the side wall 56B. Four slits 58 are formed on each of the left and right side walls 56B at intervals in the vehicle front-rear direction with the vehicle vertical direction as the longitudinal direction. Then, as shown by the arrows W1, W2, and W3 in FIG. 3, the slit 58 has a structure in which the wind sent from the front portion of the vehicle to the battery 54 side is discharged to the outside of the vehicle.

(Action and effect)
Next, the operation and effect of this embodiment will be described.

In the vehicle lower structure according to the present embodiment, the battery 54 is arranged under the floor of the vehicle 10, and the vehicle 10 is driven by supplying electric power from the battery 54 to the motor 22. Further, the battery 54 is covered from the lower side of the vehicle by the center under cover 56, and the center under cover 56 extends from both ends of the flat bottom wall 56A and the bottom wall 56A in the vehicle width direction to the upper side of the vehicle. It is configured to include the ejected side wall 56B. By making the bottom wall 56A of the center undercover 56 flat in this way, the air between the road surface and the center undercover 56 is compared with the configuration in which the bottom wall 56A of the center undercover 56 has an uneven shape. The flow can be adjusted and the aerodynamic characteristics can be improved.

Further, a slit 58 is formed in the side wall 56B of the center undercover 56, and the wind sent from the front portion of the vehicle to the battery 54 side is discharged to the outside of the vehicle by the slit 58. As a result, it is possible to prevent the running wind from disappearing around the battery 54, and it is possible to reduce the air resistance during running. As a result, the trailing distance of the vehicle 10 can be extended.

The above effect will be described in detail. As shown in FIG. 1, the front bumper cover 29 is provided with an opening 29A, and is configured to allow traveling wind to enter the power unit chamber 16 from the opening 29A. Then, the traveling wind that has entered the power unit chamber 16 passes through the heat exchanger 28, so that heat can be exchanged between the cooling water in the heat exchanger 28 and the traveling wind. In other words, the traveling wind is taken into the power unit chamber 16 in order to exchange the heat of the cooling water, and the heat exchange of the cooling water can effectively cool the motor 22. It is configured to maintain the temperature of the motor 22 in an appropriate temperature range.

Here, as shown by the arrow W1 in FIG. 3, the wind is taken into the power unit chamber 16 from the front side of the vehicle by the vehicle 10 traveling or the fan 30 operating. As shown by the arrow W2, the wind taken into the power unit chamber 16 flows from the front side of the vehicle to the rear side of the vehicle on the upper side of the vehicle with respect to the front undercover 32.

Next, the wind flowing from the front undercover 32 to the center undercover 56 is blocked by the battery module 44 (see FIG. 2), so that the wind flows around the battery module 44 on both sides in the vehicle width direction. That is, the wind flows along the side wall 56B of the center undercover 56.

Since the plurality of slits 58 are formed in the side wall 56B, at least a part of the wind flowing along the center undercover 56 can be discharged to the outside of the vehicle 10 through the slits 58. At this time, since the wind is discharged to the outside in the vehicle width direction, it is possible to suppress a decrease in steering stability as compared with a configuration in which the wind is positively discharged to the lower surface side of the vehicle 10.

Further, in the present embodiment, since a gap is provided between the front undercover 32 and the center undercover 56, a part of the wind in the power unit chamber 16 is discharged to the outside of the vehicle 10 through this gap. As a result, the air resistance during traveling can be suppressed as compared with the configuration in which the traveling wind is discharged only from the slit 58.

Although the vehicle lower structure according to the embodiment and the modified example has been described above, it is needless to say that the vehicle lower structure can be implemented in various embodiments without departing from the gist of the present invention. For example, in the above embodiment, four slits 58 are formed on the side wall 56B of the center undercover 56, but the number and shape of the slits 58 are not particularly limited. That is, five or more slits 58 may be formed on each of the left and right side walls 56B, and conversely, one to three slits 58 may be formed on the left and right side walls 56B.

Further, each slit 58 may be formed diagonally with respect to the vertical direction of the vehicle. For example, the slit 58 may be formed diagonally so as to incline toward the rear side of the vehicle from the upper side of the vehicle toward the lower side of the vehicle. On the contrary, the slit 58 may be formed diagonally so as to incline toward the front side of the vehicle as it goes from the upper side of the vehicle to the lower side of the vehicle.

Further, in the above embodiment, the power unit chamber 16 is provided in the front part of the vehicle, and the front wheels 24 are driven by the motor 22, but the present invention is not limited to this. For example, a motor 22 may be provided at the rear of the vehicle to drive the rear wheels, or both the front wheels 24 and the rear wheels may be driven by the motor 22.

Furthermore, in the above embodiment, the center undercover 56 is formed in a full flat shape without an opening, but the present invention is not limited to this. For example, if the air resistance cannot be sufficiently reduced only by discharging the running wind from the slit 58, an opening may be formed in the center undercover 56 so that the running wind is also discharged from the lower surface side of the vehicle through the opening. Even in this case, it is possible to suppress a decrease in steering stability of the vehicle as compared with a configuration in which all of the traveling wind is discharged to the lower surface side of the vehicle.

10 Vehicle 22 Motor 54 Battery (storage battery)
56 Center undercover (undercover)
56A Bottom wall 56B Side wall 58 Slit

Claims (2)

A storage battery that is placed under the floor of the vehicle and supplies electric power to the motor that drives the vehicle,
The storage battery is covered from the lower side of the vehicle, and includes a flat bottom wall facing the storage battery in the vertical direction of the vehicle and a side wall extending from both ends of the bottom wall in the vehicle width direction toward the upper side of the vehicle. Undercover and
A vehicle lower structure having a slit formed on the side wall of the undercover on the outer side of the storage battery in the vehicle width direction and for discharging the wind sent from the front portion of the vehicle to the storage battery side to the outside of the vehicle. A front undercover that covers the power unit chamber from the lower side of the vehicle is provided in front of the vehicle from the undercover.
The vehicle lower structure according to claim 1, wherein a gap is provided between the undercover and the front undercover.

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