Vehicle

A vehicle may include a body including a rear surface defining an opening, a door configured to open and close the opening, and a rear bumper reinforcement fixed to a portion of the body located below the opening via a crash box. The body may include a lower back reinforcement extending in a vehicle widthwise direction along a lower edge of the opening and at least a part of the lower back reinforcement may be located directly above the rear bumper reinforcement in a vehicle height direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2020-072314, filed on Apr. 14, 2020, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The art disclosed herein relates to a vehicle.

BACKGROUND

Japanese Patent Application Publication No. 2011-131695 describes a vehicle. This vehicle incudes a body having a rear surface defining an opening, a door configured to open and close the opening, and a rear bumper reinforcement fixed to a portion of the body located below the opening via a crash box. The crash box is designed to be subjected to compressive deformation when a collision load is exerted on the rear bumper reinforcement due to a rear-end collision to the vehicle. The collision energy is thereby absorbed and deformation of the body is effectively mitigated.

SUMMARY

However, in a rear-end collision to a vehicle, a colliding object, such as a vehicle coming from behind, may collide hard to a relatively high portion of the vehicle. In this case, a collision load exerted on a rear bumper reinforcement includes a downward component of force, as a result of which a crash box may be subjected to bending deformation. When such deformation occurs in the crash box, an amount of collision energy absorbed by the crash box degreases significantly. As a result, deformation of a body cannot be mitigated sufficiently. The disclosure herein provides art that enables reduction in unintended deformation of a crash box as exemplified above.

The present teachings may provide a vehicle. The vehicle may comprise a body comprising a rear surface defining an opening, a door configured to open and close the opening and, a rear bumper reinforcement fixed to a portion of the body located below the opining via a crash box. The body may comprise a lower back reinforcement extending in a vehicle widthwise direction along a lower edge of the opening, and at least a part of the lower back reinforcement may be located directly above the rear bumper reinforcement in a vehicle height direction. In other words, the lower back reinforcement and the rear bumper reinforcement are arranged such that they partially overlap each other in a planar view of the vehicle. It should be noted that the phrase “directly above” merely limits a direction of the lower back reinforcement relative to the rear bumper reinforcement, and does not limit the distance between the lower back reinforcement and the rear bumper reinforcement.

In the above vehicle, the lower back reinforcement of the body is located above the rear bumper reinforcement. In this configuration, when a rear-end collision occurs to the vehicle, both the lower back reinforcement and the rear bumper reinforcement can receive the collision load. Thus, even when a colliding object, such as a vehicle coming from behind, collides to a relatively high portion of the vehicle, a downward collision load is less likely to be exerted on the rear bumper reinforcement, thereby reducing bending deformation of the crash box.

DETAILED DESCRIPTION

In an embodiment of the art disclosed herein, the lower back reinforcement may have a shape that defines an enclosed cavity extending in a vehicle widthwise direction. Such a configuration enables an increase in the strength (or resistance) of the lower back reinforcement while diminishing a weight increase of the body. The shape of the lower back reinforcement is not limited to the shape defining the enclosed cavity, and the lower back reinforcement may have a groove shape (such as a shape of a channel member) in another embodiment.

In the above embodiment, the lower back reinforcement may comprise a bulkhead that extends in the vehicle widthwise direction (that is, in a longitudinal direction of the lower back reinforcement) in the enclosed cavity. In other words, the lower back reinforcement may have a shape that defines two or more enclosed cavities in the vehicle widthwise direction. Such a configuration enables a further increase in the strength (or resistance) of the lower back reinforcement.

In an embodiment of the art disclosed herein, a lowest portion of the lower back reinforcement may be located forward of the rear bumper reinforcement and be located lower than a highest portion of the rear bumper reinforcement. In such a configuration, the lower back reinforcement is disposed proximate to the rear bumper reinforcement, thus a downward collision load is even less likely to be exerted on the rear bumper reinforcement, thereby reducing bending deformation of the crash box further.

In an embodiment of the art disclosed herein, the body may further comprise a rear side member that extends in a vehicle longitudinal direction. In this case, the crash box may extend rearward from a rear end of the rear side member. In such a configuration, a collision load exerted on the rear bumper reinforcement is transmitted to the rear side member through the crash box. When the collision load is relatively large, not only the crash box but also the rear end of the rear side member is subjected to compressive deformation, thereby absorbing a greater amount of collision energy.

In the above embodiment, a height difference between a highest portion of the rear side member and a lowest portion of the lower back reinforcement may be at most 30 millimeters. In such a configuration, the lower back reinforcement is disposed proximate to the rear side member, thus the rear side member can sufficiently receive a collision load exerted on the lower back reinforcement.

In the disclosure herein, terms such as forward, rearward, and a longitudinal direction respectively refer to forward, rearward, and a longitudinal direction with respect to the vehicle. Similarly, terms such as leftward, rightward, and a widthwise direction respectively refer to leftward, rightward, and a widthwise direction with respect to the vehicle, and terms such as upward, downward, and a height direction respectively refer to upward, downward, and a height direction with respect to the vehicle. For example, when the vehicle is placed on a horizontal surface, the height direction of the vehicle matches a vertical direction. Further, the widthwise direction of the vehicle is a direction parallel to an axle of the vehicle, and the longitudinal direction of the vehicle is a direction parallel to the horizontal surface and perpendicular to the axle of the vehicle.

First Embodiment

A vehicle10according to a first embodiment will be described with reference to the drawings. As shown inFIGS.1to3, the vehicle10according to the present embodiment includes a body12, a plurality of wheels14, and a door16. Although not particularly limited, the body12is constituted of metal. The body12is of a hatchback type, and a rear opening13is defined in a mar surface12rthereof. The door16is supported pivotably by the body12and is configured to open and close the rear opening13. The plurality of wheels14includes a pair of rear wheels as shown in the drawings and a pair of front wheels which are not shown in the drawings. The number of the wheels14is not limited to four. Further, a direction in which the door16pivots is not limited to the height direction, but may be a horizontal direction for example.

Although not particularly limited, the vehicle10according to the present embodiment is an electric powered vehicle configured to drive the wheels14by a traction motor (not shown). The electric powered vehicle herein includes a rechargeable electric vehicle configured to be charged by an external power source, a hybrid vehicle including both an engine and a traction motor, and a fuel cell vehicle that uses a fuel cell as its power source, for example. The art disclosed herein can be applied not only to an electric powered vehicle but also to an engine vehicle including only an engine as its prime mover.

In the drawings, a direction FR indicates a forward direction of the longitudinal direction of the vehicle10, and a direction RR indicates a rearward direction of the longitudinal direction of the vehicle10. Further, a direction LH indicates a leftward direction of the widthwise direction of the vehicle10, and a direction RH indicates a rightward direction of the widthwise direction of the vehicle10. Further, a direction UP indicates an upward direction of the height direction of the vehicle10, and a direction DW indicates a downward direction of the height direction of the vehicle10. In the following embodiments as well, the frontward direction, the rearward direction, and the longitudinal direction of the vehicle10may respectively be termed simply the frontward direction, the rearward direction, and the longitudinal direction; the leftward direction, the rightward direction, and the widthwise direction of the vehicle10may respectively be termed simply the leftward direction, the rightward direction, and the widthwise direction; and the upward direction, the downward direction, and the height direction of the vehicle10may respectively be termed simply the upward direction, the downward direction, and the height direction.

The body12includes a pair of rear side members18, a back panel20, and a lower back reinforcement22. The rear side members18are disposed symmetric with respect to the widthwise direction, and each of them extends in the longitudinal direction. The back panel20is a panel member that configures the rear surface12rof the body12and is connected to rear ends18aof the pair of rear side members18. The back panel20extends from the pair of rear side members18toward the rear opening13and defines a lower edge13aof the rear opening13.

The lower back reinforcement22is disposed along the back panel20and extends in the widthwise direction along the lower edge13aof the rear opening13. The lower back reinforcement22is a member for increasing the strength (or resistance) of the back panel20and has a shape that, together with the back panel20, forms a tubular member defining an enclosed cavity23along the widthwise direction. Such a configuration enables an increase in the strength (or resistance) of the lower back reinforcement22while diminishing a weight increase in the body12. The shape of the lower back reinforcement22is not limited to the shape that defines the enclosed cavity23, and the shape may, for example, be a groove shape (such as a shape of a channel member) in another embodiment.

The vehicle10further includes a pair of crash boxes24and a rear bumper reinforcement26. The rear bumper reinforcement26is located below the rear opening13and extends in the widthwise direction. The rear bumper reinforcement26is fixed to a portion of the body12that is located blow the rear opening13via the pair of crash boxes24. Each of the crash boxes24is a member for absorbing collision energy of a rear-end collision and is designed to be subjected to compressive deformation in a predetermined manner when a collision load is exerted thereon. Although not particularly limited, in the vehicle10according to the present embodiment, each of the crash boxes24is connected to the rear end18aof the corresponding one of the rear side members18and extends rearward from the rear end18a.

As clearly shown inFIG.3, at least a part of the lower back reinforcement22is located directly above the rear bumper reinforcement26in the height direction (see a range A inFIG.3). In other words, in a planar view of the vehicle10, the lower back reinforcement22and the rear bumper reinforcement26are arranged such that they at least partially overlap each other. In such a configuration, when a rear-end collision occurs to the vehicle10as shown inFIG.4, both the lower back reinforcement22and the rear bumper reinforcement26can receive the collision load. Thus, even when a colliding object, such as a vehicle100coming from behind, collides to a relatively high portion of the vehicle10, a downward collision load is less likely to be exerted on the rear bumper reinforcement26, thereby reducing bending deformation of the crash boxes24.

Especially in the vehicle10according to the present embodiment, the lower back reinforcement22is disposed proximate to the rear bumper reinforcement26. Specifically, a minimum distance D between the lower back reinforcement22and the rear bumper reinforcement26in the height direction is smaller than a size of the lower back reinforcement22in the height direction and a size of the rear bumper reinforcement26in the height direction. Such a configuration in which the lower back reinforcement22is disposed proximate to the rear bumper reinforcement26can more effectively reduce exertion of a downward collision load on the rear bumper reinforcement26.

In the vehicle10according to the present embodiment, as described, each of the crash boxes24is connected to the rear end18aof the corresponding one of the rear side members18and extends rearward from the rear end18a. In such a configuration, a collision load exerted on the rear bumper reinforcement26is transmitted to the pair of rear side members18through the pair of crash boxes24. When the collision load is relatively large, rear end portions of the rear side members18as well as the crash boxes24are subjected to compressive deformation, thereby absorbing a greater amount of the collision energy.

In addition, in the vehicle10according to the present embodiment, the lower back reinforcement22is connected to the rear ends18aof the pair of rear side members18via the back panel20. In such a configuration, a collision load exerted on the lower back reinforcement22is also transmitted to the pair of rear side members18through the back panel20. As such, the collision energy inputted to the lower back reinforcement22can also be absorbed by the rear end portions of the rear side members18being subjected to compressive deformation.

In the vehicle10according to the present embodiment, a height difference H between a highest portion18xof each of the rear side members18and a lowest portion22xof the lower back reinforcement22is designed to be 10 millimeters. In such a configuration, the lower back reinforcement22is disposed proximate to the rear side members18, thus the rear side members18can sufficiently receive a collision load exerted on the lower back reinforcement22. The aforementioned height difference H is not limited to 10 millimeters, and may, for example, be 30 mm at most, and more preferably 20 mm at most.

Second Embodiment

A vehicle110according to a second embodiment will be described with reference toFIG.5. The configuration of a lower back reinforcement122of the vehicle110according to the present embodiment is different from the configuration of the lower back reinforcement22of the vehicle10according to the first embodiment. Hereinbelow, differences from the first embodiment will be mainly explained, and the same reference signs are given to configurations that are the same as or corresponding to those of the first embodiment and descriptions thereof will be omitted.FIG.5is a cross-sectional view corresponding toFIG.3of the first embodiment.

As shown inFIG.5, the lower back reinforcement122according to the second embodiment includes a bulkhead124inside its enclosed cavity123. The bulkhead124extends in the widthwise direction (that is, in a longitudinal direction of the lower back reinforcement122) and at least partially divides the enclosed cavity123into two. Such a configuration enables a further increase in the strength (or resistance) of the lower back reinforcement122. A structure having such a bulkhead124is especially advantageous when a cross-sectional area of the lower back reinforcement122, that is, a cross-sectional area of the enclosed cavity123is large, and two or more bulkheads124may be provided based on the cross-sectional area of the enclosed cavity123.

In the vehicle110according to the second embodiment as well, at least a part of the lower back reinforcement122is located directly above the rear bumper reinforcement26in the height direction. Further, the lower back reinforcement122is connected to the rear ends18aof the pair of rear side members18via the back panel20. Further, a height difference H between the highest portion18xof each of the pair of rear side members18and a lowest portion122xof the lower back reinforcement122is designed to be 30 millimeters at most (for example, 10 millimeters). As described above, the lower back reinforcement122according to the second embodiment has major features of the lower back reinforcement22according to the first embodiment, and thus similarly can reduce the bending deformation of the crash boxes24.

Third Embodiment

A vehicle210according to a third embodiment will be described with reference toFIGS.6and7. The configuration of a lower back reinforcement222of the vehicle210according to the present embodiment is different from the configuration of the lower back reinforcement22of the vehicle10according to the first embodiment. Hereinbelow, differences from the first embodiment will be explained mainly, and the same reference signs are given to configurations that are the same as or corresponding to those of the first embodiment and descriptions thereof will be omitted.FIG.6is a cross-sectional view corresponding toFIG.3of the first embodiment.FIG.7is a cross-sectional view parallel to the one shown inFIG.6, and shows a cross section at a center of the vehicle210in the widthwise direction.

As shown inFIGS.6and7, the lower back reinforcement222according to the third embodiment has a shape of which height changes along the widthwise direction, and the height is the lowest at the center of the vehicle210in the widthwise direction. Further, at the center of the vehicle210in the widthwise direction (that is, inFIG.7), a lowest portion222xof the lower back reinforcement222is located forward of the rear bumper reinforcement26and below the highest portion26xof the rear bumper reinforcement26. In such a configuration, the lower back reinforcement222is disposed proximate to the rear bumper reinforcement26, thus a downward collision load is even less likely to be exerted on the rear bumper reinforcement26and the bending deformation of the crash boxes24can thereby further be reduced.

In the vehicle210according to the third embodiment as well, at least a part of the lower back reinforcement222is located directly above the rear bumper reinforcement26in the height direction. Further, the lower back reinforcement222has a shape that defines an enclosed cavity223and is connected to the rear ends18aof the pair of rear side members18via the back panel20. As described above, the lower back reinforcement222according to the third embodiment also has the major features of the lower back reinforcement22according to the first embodiment and similarly can reduce the bending deformation of the crash boxes24.