Patent Publication Number: US-2022234655-A1

Title: Vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2021-010497 filed on Jan. 26, 2021, incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The technology disclosed in the present specification relates to a vehicle. 
     2. Description of Related Art 
     Japanese Unexamined Patent Application Publication No. 2015-101218 (JP 2015-101218 A) describes a base structure of a vehicle body. The vehicle body includes a floor panel, a dash panel located at a front end of the floor panel, a dash cross member extending in a right-left direction along the dash panel, and a center tunnel extending rearward from the dash panel along the floor panel. The dash cross member is divided into right and left portions by the center tunnel. On both sides of the center tunnel, a plurality of reinforcements extending rearward from the dash cross member is provided along the floor panel. According to such a configuration, a collision load due to a frontal collision, for example, is dispersed among the center tunnel and the reinforcements, so that unintended deformation of the vehicle body can be reduced. 
     SUMMARY 
     Vehicles with traction motors, which are so-called electric vehicles, are coming into widespread use. This type of vehicle requires a relatively large battery pack, which can, for example, occupy an extra space in a vehicle cabin. Accordingly, a layout in which such a large battery pack is disposed below a floor panel is effective. In some embodiments, when such a layout is employed, the floor panel is flat, for example, from the perspective of lowering the floor panel. Accordingly, providing the aforementioned reinforcements along the floor panel is difficult. However, when the reinforcements are not provided, a collision load due to a frontal collision or the like is primarily applied to a center tunnel. In such a case, a dash cross member and a center tunnel need to be strongly joined. 
     The present specification provides technology for strongly joining a dash cross member and a center tunnel in a vehicle in which a battery pack is disposed below a floor panel. 
     The technology disclosed in the present specification is used in a vehicle including a traction motor. A vehicle according to an aspect disclosed in the present specification includes a vehicle body and a battery pack. The vehicle body includes: a floor panel, a dash panel located at a front end of the floor panel, a first dash cross member and a second dash cross member extending in a right-left direction of the vehicle along the dash panel, a center tunnel extending from the dash panel rearward in the vehicle along the floor panel. The battery pack is disposed below the floor panel and is configured to supply electric power to the traction motor. The first dash cross member includes a right side portion extending from a right side face of the center tunnel to a right end of the dash panel and a left side portion extending from a left side face of the center tunnel to a left end of the dash panel. The second dash cross member is located above the first dash cross member and continues from the right end to the left end of the dash panel, and at least a part of the second dash cross member extends to curve along the right side face, an upper face, and the left side face of the center tunnel. 
     In the above structure, two dash cross members are provided along the dash panel. The first dash cross member located below the second dash cross member is divided into right and left portions by the center tunnel, with the right side portion and the left side portion being connected to the respective side faces of the center tunnel. On the other hand, the second dash cross member located above the first dash cross member continues to extend along the outline of the center tunnel. At least the part of the second dash cross member adjacent to the center tunnel extends to curve along a shape of the center tunnel. According to such a configuration, the two dash cross members are connected to the center tunnel over a long distance, so that the dash cross members and the center tunnel are strongly joined. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: 
         FIG. 1  is a left side view of a vehicle; 
         FIG. 2  is a planar view schematically illustrating a structure of a vehicle body; and 
         FIG. 3  is a perspective view illustrating a joining portion of dash cross members and a center tunnel. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In an embodiment of the present technology, a width dimension of each of a right side portion and a left side portion of a first dash cross member in a front-rear direction of a vehicle may increase toward a center tunnel. According to such a configuration, the right side portion and the left side portion of the first dash cross member each include a large cross-section at a position where each of the right side portion and the left side portion is connected to the center tunnel, so that each of the right side portion and the left side portion is joined more strongly to the center tunnel. 
     In the above embodiment, a second dash cross member extends to curve from a right end to a left end of a dash panel, with at least a part of the second dash cross member coming into contact with the first dash cross member. For example, the second dash cross member may extend to curve along an upper edge of the first dash cross member of which the width dimension changes. According to such a configuration, the unity of the first dash cross member and the second dash cross member can be improved. 
     A vehicle  10  according to the embodiment will be described with reference to the drawings. The vehicle  10  according to the embodiment is a so-called automobile, and is a vehicle that travels on a road surface. Note that the direction FR in the drawings indicates forward in a front-rear direction (vehicle-length direction) of the vehicle  10 , and the direction RR indicates rearward in the front-rear direction of the vehicle  10 . Also, the direction LH indicates leftward in a right-left direction (vehicle-width direction) of the vehicle  10 , and the direction RH indicates rightward in the right-left direction of the vehicle  10 . The direction UP indicates upward in an up-down direction (vehicle-height direction) of the vehicle  10 , and the direction DN indicates downward in the up-down direction of the vehicle  10 . Note that in the present specification, the front-rear direction, the right-left direction, and the up-down direction, of the vehicle  10  may be simply referred to as the front-rear direction, the right-left direction, and the up-down direction, respectively. 
     As illustrated in  FIGS. 1 and 2 , the vehicle  10  is provided with a vehicle body  12  and a plurality of wheels  14   f  and  14   r . The vehicle body  12  is primarily configured using a metal material, although this is not particularly limited. The wheels  14   f  and  14   r  are rotatably attached to the vehicle body  12 . The wheels  14   f  and  14   r  include a pair of front wheels  14   f  and a pair of rear wheels  14   r . Note that the number of wheels  14   f  and  14   r  is not limited to four. The vehicle body  12  can be generally sectioned into a cabin  12   c  in which a user rides, a front portion  12   f  located forward of the cabin  12   c , and a rear portion  12   r  located rearward of the cabin  12   c.    
     The vehicle body  12  is provided with a floor panel  20 , a pair of rockers  22 , a pair of front side members  24 , and a pair of rear side members  26 . The floor panel  20  is a plate-like member that extends in the front-rear direction and the right-left direction, and constitutes a floor of the cabin  12   c . A plurality of floor cross members  28  is provided on an upper face of the floor panel  20 . Each floor cross member  28  has a generally tubular structure, and constitutes a part of a framework of the vehicle body  12 . 
     The rockers  22  (also referred to as side sills) each extend in the front-rear direction along right and left side edges of the floor panel  20 . Each rocker  22  has a generally tubular structure, and constitutes a part of the framework of the vehicle body  12 . Front ends of the rockers  22  are connected to the front side members  24  via dash cross members  32  and  34  described below. Rear ends of the rockers  22  are connected to the rear side members  26 . Inside each rocker  22 , one or a plurality of bulkheads (partitions) may be provided to increase the strength and rigidity of the rocker  22 . 
     The front side members  24  are located at a front portion  12   f  and each extend forward. The front side members  24  have a generally tubular structure extending in the front-rear direction, and constitutes a part of the framework of the vehicle body  12 . A front bumper reinforcement is attached to a front end of each of the front side members  24 , although it is not shown. The rear side members  26  are located at a rear portion  12   r  and extend rearward continuing from the rockers  22 . The rear side members  26  have a generally tubular structure extending in the front-rear direction, and constitutes a part of the framework of the vehicle body  12 . A rear bumper reinforcement is attached to a rear end of each of the rear side members  26 , although it is not shown. 
     The vehicle body  12  is further provided with a dash panel  30 , two dash cross members  32  and  34 , and a center tunnel  36 . The dash panel  30  is located at a front end of the floor panel  20  and constitutes a partition wall that separates the front portion  12   f  and the cabin  12   c . The two dash cross members  32  and  34  extend in the right-left direction along the dash panel  30 . The two dash cross members  32  and  34  include a first dash cross member  32  and a second dash cross member  34 . Each dash cross member  32  and  34  has a generally tubular structure, and constitutes a part of the framework of the vehicle body  12 . Specific configurations of the first dash cross member  32  and the second dash cross member  34  will be described in detail below. The center tunnel  36  extends rearward from the dash panel  30  along the floor panel  20 . The center tunnel  36  is located at the middle of the floor panel  20  in the right-left direction, and protrudes upward with respect to the floor panel  20 . 
     The vehicle  10  is further provided with a traction motor  16  and a battery pack  18 . The traction motor  16  is disposed in the front portion  12   f , although this is not particularly limited. The traction motor  16  is connected to the front wheels  14   f  and drives the front wheels  14   f . Note that the vehicle  10  may be provided with a second traction motor that drives the rear wheels  14   r , in addition to, or instead of, the traction motor  16  that drives the front wheels  14   f . Further, the vehicle  10  may be provided with another prime mover such as an engine, in addition to the traction motor  16 . 
     The battery pack  18  is disposed below the floor panel  20  and is located between the rockers  22 . The battery pack  18  is a power source for the traction motor  16 , and stores electric power to be supplied to the traction motor  16 . The battery pack  18  is electrically connected to the traction motor  16  via a power supply circuit (not shown) such as a direct current-direct current (DC-DC) converter or an inverter. The battery pack  18  in the present embodiment includes a plurality of cell stacks  18   a , although this is not particularly limited. Each cell stack  18   a  includes a plurality of lithium-ion battery cells (or other secondary battery cells), and is configured to be rechargeable. Note that the vehicle  10  may be provided with other power sources, such as a fuel cell unit, a solar cell panel, or the like, in addition to the battery pack  18 . 
     Next, the configurations of the two dash cross members  32  and  34  will be described. As illustrated in  FIGS. 2 and 3 , the first dash cross member  32  is located below the second dash cross member  34 , and is divided into right and left portions by the center tunnel  36 . That is to say, the first dash cross member  32  includes a right side portion  32   a  extending from a right side face  36   a  of the center tunnel  36  to the right end of the dash panel  30 , and a left side portion  32   b  extending from a left side face  36   b  of the center tunnel  36  to the left end of the dash panel  30 . 
     The second dash cross member  34  is located above the first dash cross member  32 , and extends to continue from the right end to the left end of the dash panel  30 . An intermediate portion  34   a  of the second dash cross member  34  extends to curve along the right side face  36   a , an upper face  36   c , and the left side face  36   b  of the center tunnel  36 . That is to say, the second dash cross member  34  is not divided by the center tunnel  36 , and extends above the center tunnel  36  to circumvent the center tunnel  36 . 
     As described above, in the vehicle  10  according to the present embodiment, the two dash cross members  32  and  34  are provided along the dash panel  30 . The first dash cross member  32  located below the second dash cross member  34  is divided into the right and left portions by the center tunnel  36 , with the right side portion  32   a  and the left side portion  32   b  being connected to the side faces  36   a  and  36   b  of the center tunnel  36 , respectively. On the other hand, the second dash cross member  34  located above the first dash cross member  32  continues to extend along the outline of the center tunnel  36 . The intermediate portion  34   a  of the second dash cross member  34  adjacent to the center tunnel  36  extends to curve along the shape of the center tunnel  36 . According to such a configuration, the two dash cross members  32  and  34  are connected to the center tunnel  36  over a long distance, so that the dash cross members  32  and  34  and the center tunnel  36  are strongly joined. 
     When the dash cross members  32  and  34  and the center tunnel  36  are strongly joined, a collision load due to a frontal collision or the like, for example, can be primarily applied to the center tunnel  36 . Accordingly, providing a great number of reinforcements on the floor panel  20  is unnecessary, and the shape of the floor panel  20  can be made to be relatively flat. Thus, it is possible to reduce a possibility that the position of the floor panel  20  is high even in a layout in which the battery pack  18  is disposed below the floor panel  20 , and the floor of the vehicle  10  can be lowered. 
     In the vehicle  10  according to the present embodiment, the right side portion  32   a  and the left side portion  32   b  of the first dash cross member  32  each have a shape in which the width dimension W of each of the right side portion  32   a  and the left side portion  32   b  in the front-rear direction of the vehicle increases toward the center tunnel  36  (See  FIG. 3 ), although this is not particularly limited. According to such a configuration, the right side portion  32   a  and the left side portion  32   b  of the first dash cross member  32  each include a large cross-section at a position where each of the right side portion  32   a  and the left side portion  32   b  is connected to the center tunnel  36 , so that the first dash cross member  32  and the center tunnel  36  are joined more strongly. Additionally, the second dash cross member  34  extends to curve from the right end to the left end of the dash panel  30 , with at least a part of the second dash cross member  34  coming into contact with the first dash cross member  32 . For example, the second dash cross member  34  extends to curve along an upper edge  32   c  of the first dash cross member  32  of which the width dimension W changes. According to such a configuration, the unity of the first dash cross member  32  and the second dash cross member  34  can be improved, and the strength and rigidity required of the vehicle body  12  can be realized more readily. 
     In the vehicle  10  according to the present embodiment, specific configurations of the two dash cross members  32  and  34  can be changed as appropriate. As described above, each of the dash cross members  32  and  34  is a structural member having a tubular structure that forms a closed space extending in the right-left direction. With regard to this point, the shapes of the closed spaces formed by the dash cross members  32  and  34  (that is to say, the cross-sectional shapes of the dash cross members  32  and  34 ) are not particularly limited. Also, one or both of the two dash cross members  32  and  34  may have a shape in which two or more closed spaces extending in the right-left direction are formed. Further, the closed spaces formed by the dash cross members  32  and  34  may be formed by the dash cross members  32  and  34  alone, or may be formed in conjunction with the dash panel and other members.