Patent Publication Number: US-2023159106-A1

Title: Vehicle body

Description:
TECHNICAL FIELD 
     The present invention relates to a vehicle body including a center pillar that is located at a boundary between a front side door and a rear side door and extends downward from a roof, a side sill that is coupled to a lower end of the center pillar to partition a lower end of a door opening opened and closed by the front side door and the rear side door, and a side outer panel that forms an outer surface with the center pillar and the side sill. 
     BACKGROUND ART 
     Patent Document 1 discloses a side sill that is coupled to a lower end of a center pillar and partitions a lower end of a door opening opened and closed by a front side door and a rear side door. The side sill includes an outer panel including: an upper wall that extends continuously from the center pillar so as to surround an opening for a front side door on a front side and an opening for a rear side door on a rear side; a vertical wall (side wall) that is formed by bending downward from an outer end of the upper wall and spreads along a vertical plane; and a lower wall that is formed by bending inward from a lower end of the vertical wall toward an interior space. 
     Patent Document 1: Japanese Patent No. 6070948 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     The outer panel of the side sill is formed with a step extending in a front-rear direction along an upper ridge of the vertical wall. A plurality of beads are arranged in the front-rear direction on the lower wall. Flexural rigidity of the side sill can be enhanced in the front-rear direction by a behavior of the step and the beads. 
     The side sill thermally expands in the front-rear direction based on heating during drying of electrodeposition painting. In Patent Document 1, since the rigidity of the lower wall is weakened at a central position in the front-rear direction, only the lower wall is exposed to permanent strain at the central position in the front-rear direction. The vertical wall is avoided from deforming in this way, and thus the satisfactory appearance is maintained. On the other hand, in such a structure, when the step of the vertical wall is omitted or the vertical wall extends in an up-down direction (height direction), the permanent strain may not be absorbed in time and the permanent strain may appear on the vertical wall. Therefore, the design of the side sill is limited. 
     An object of the present invention is to provide a vehicle body capable of preventing (avoiding) deformation of the side sill that is visible while allowing a variety of designs of the side sill. 
     Means for Solving the Problems 
     According to a first aspect of the present invention, a vehicle body includes: a center pillar that is located at a boundary between a front side door and a rear side door and extends downward from a roof; a side sill that is coupled to a lower end of the center pillar and partitions a lower end of a door openings opened and closed by the front side door and the rear side door; and a side outer panel that forms an outer surface with the center pillar and the side sill and includes a first ridge that partitions an opening for the front side door and a second ridge that partitions an opening for the rear side door, in which the side outer panel includes: a base portion that swells from the outer surface, enters the side sill from the center pillar, and forms a front ridge extending along the first ridge of the center pillar and crossing an upper edge of the side sill, and a rear ridge extending along the second ridge of the center pillar and crossing an upper edge of the side sill; a front side sill portion that extends in a front-rear direction in front of the base portion and forms a first groove between the front side sill portion and the base portion; and a rear side sill portion that extends in the front-rear direction behind the base portion and forms a second groove between the rear side sill portion and the base portion. 
     According to a second aspect, in addition to the configuration of the first aspect, a side wall of the first groove is continuous from the front ridge, and a side wall of the second groove is continuous from the rear ridge. 
     According to a third aspect, in addition to the configuration of the first or second aspect, the vehicle body further includes a first bead that is formed on the front side sill portion and extends in the front-rear direction and a second bead that is formed on the rear side sill portion and extends in the front-rear direction. 
     According to a fourth aspect, in addition to the configuration of the third aspect, the first bead and the second bead include beads that are recessed inward within beads that swell outward, respectively. 
     According to a fifth aspect, in addition to the configuration of the third aspect, the first bead and the second bead include curved surfaces that have a generating line extending in the front-rear direction and are curved so as to swell outward, respectively. 
     According to a sixth aspect, in addition to the configuration of the third aspect, an upper end and a lower end of the first groove are partitioned by steps that are formed on extension lines of an upper edge and a lower edge of the first bead, respectively, and an upper end and a lower end of the second groove are partitioned by steps that are formed on extension lines of an upper edge and a lower edge of the second bead, respectively. 
     According to a seventh aspect, in addition to the configuration of the first aspect, the side outer panel includes: a front upper wall that extends continuously from the center pillar so as to surround the opening for the front side door; a front vertical wall that is formed by bending downward from an outer end of the front upper wall and spreads along a vertical plane to define the first ridge between the front vertical wall and the front upper wall; and a front lower wall that is formed by bending toward an interior space from a lower end of the front vertical wall to define a third ridge between the front lower wall and the front vertical wall, and the front lower wall includes an electrodeposition hole formed at a front-rear direction position intersecting the first groove. 
     According to an eighth aspect, in addition to the configuration of the first aspect, the side outer panel includes: a rear upper wall that extends continuously from the center pillar so as to surround the opening for the rear side door; a rear vertical wall that is formed by bending downward from an outer end of the rear upper wall and spreads along a vertical plane to define the second ridge between the rear vertical wall and the rear upper wall; and a rear lower wall that is formed by bending toward an interior space from a lower end of the rear vertical wall to define a fourth ridge between the rear lower wall and the rear vertical wall, and the rear lower wall includes a bead formed at a front-rear direction position intersecting the second groove and extending orthogonally to the fourth ridge. 
     According to a ninth aspect, in addition to the configuration of the first aspect, the side outer panel further includes an auxiliary base portion that swells from the outer surface while continuing upward from the base portion, a door hinge mounting area being arranged between the auxiliary base portion and the base portion. 
     According to a tenth aspect, in addition to the configuration of the first aspect, the base portion forms a receiving body that swells in a truncated cone shape from the outer surface at a position closer to the first groove than the second groove and receives a stopper of the front side door at a closed position of the front side door. 
     According to an eleventh aspect, in addition to the configuration of the first aspect, the vehicle body further includes: a side sill stiffener that is joined to a side sill inner panel to form the side sill while reinforcing a flexural strength of the side sill; and a center pillar stiffener that is joined to a center pillar inner panel to form the center pillar while reinforcing a flexural strength of the center pillar and is coupled to the side sill stiffener at a lower end partitioned in the front-rear direction at the first groove and the second groove. 
     Effects of the Invention 
     According to the first aspect, the front side sill portion and the rear side sill portion of the side outer panel thermally expand in the front-rear direction based on heating during drying of electrodeposition painting. At this time, since the rigidity of the base portion is ensured by the behavior of the swelling forming the front ridge and the rear ridge, the thermal expansion of the front side sill portion and the thermal expansion of the rear side sill portion can be absorbed according to the collapse of the first groove and the second groove. Below the center pillar, the side sill can prevent (avoid) the occurrence of permanent strain of the side outer panel. Since only the first groove and the second groove collapse, the visible side sill is prevented (avoided) from deforming. 
     According to the second aspect, when the side outer panel appears on the exterior of the vehicle, the first groove and the second groove are visually integrated with the base portion, and thus the deterioration of the appearance can be prevented regardless of the formation of the first groove and the second groove. 
     According to the third aspect, since the front side sill portion and the rear side sill portion are enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove and the second groove while preventing the deformation of the front side sill portion and the rear side sill portion. 
     According to the fourth aspect, since the front side sill portion and the rear side sill portion are further enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove and the second groove while preventing the deformation of the front, side sill portion and the rear side sill portion. 
     According to the fifth aspect, since the front side sill portion and the rear side sill portion are enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove and the second groove while preventing the deformation of the front side sill portion and the rear side sill portion. Moreover, since the first bead and the second bead form the curved surface that swells outward, the first bead and the second bead can be satisfactorily visually recognized from a line of sight looking downward of the occupant getting on and off. The existence of the vertical wall can be confirmed. Designability can be ensured. When the vertical wall of the bead is hidden from the line of sight looking downward of the occupant, the occupant misunderstands that the vertical wall is missing. It becomes a design that makes feel instability of the structure. 
     According to the sixth aspect, the depth of the first groove and the second groove can be increased by the behavior of the step. Deformation of the first groove and the second groove can be promoted when the first groove and the second groove are deepened. Moreover, since the step extends in a straight line from the first bead and the second bead, a complicated uneven shape can be reduced and the appearance can be satisfactorily ensured. 
     According to the seventh aspect, since the strength of the front lower wall is weakened at the front-rear direction position intersecting the first groove by the behavior of the electrodeposition hole, the deformation of the bottom wall can be promoted in the first groove in addition to the fall of the side wall. The collapse of the first groove can be further accelerated. In this way, the thermal expansion of the front side sill portion can be absorbed. In the side sill, the occurrence of the permanent strain of the side outer panel can be prevented (avoided). 
     According to the eighth aspect, the beads can prevent spring-back between the rear vertical wall and the rear lower wall at the time of molding the side outer panel. Although these beads are formed on the rear lower wall at the front-rear direction position intersecting the second groove, a stress is concentrated at a central position of the side sill in the front-rear direction, the stress concentrated in this way is absorbed by the first groove, and the second groove on the rear side plays a complementary role, whereby the beads do not hinder the prevention of the thermal expansion. 
     According to the ninth aspect, since the base portion and the auxiliary base portion are continuous so as to surround the door hinge mounting area, it is possible to reduce a complicated uneven shape and further improve the appearance, such simplification of the uneven shape can prevent the occurrence of wrinkles during a pressing process of the side outer panel. Moreover, since the rigidity of the base portion is further increased due to the addition of the auxiliary base portion, the absorption of thermal expansion can be further promoted in the first groove and the second groove. 
     According to the tenth aspect, in the base portion, the rigidity can be increased on the first groove side as compared with the second groove side. Since the stress is concentrated at the central position of the side sill in the front-rear direction, the collapse of the first, groove can be satisfactorily promoted. 
     According to the eleventh aspect, during a side collision, the impact acting on the center pillar stiffener is supported by the side piller coupled to the lower end of the center pillar stiffener. At this time, since the first groove and the second groove are arranged at the edge of the center pillar stiffener, the first groove and the second groove do not affect the collision performance during the side collision. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view showing an appearance of a vehicle according to an embodiment of the present invention; (first embodiment) 
         FIG.  2    is a side view of a side panel according to a first, embodiment of the present invention; (first embodiment) 
         FIG.  3    is an enlarged perspective view showing a shape of a side outer panel; (first embodiment) 
         FIG.  4    is a side view of a side panel according to a second embodiment of the present invention; (second embodiment) 
         FIG.  5    is an enlarged side view showing a shape of a side outer panel; (second embodiment) 
         FIG.  6    is a cross-sectional view taken along a line  6 - 6  in  FIG.  5   ; (second embodiment) 
         FIG.  7    is a cross-sectional view taken along a line  7 - 7  in  FIG.  5   ; (second embodiment) 
         FIG.  8    is a cross-sectional view taken along a line  8 - 8  in  FIG.  5   ; (second embodiment) 
         FIG.  9    is an enlarged perspective view showing a front side sill portion of the side outer panel; (second embodiment) 
         FIG.  10    is an enlarged perspective view showing a rear side sill portion of the side outer panel; (second embodiment) and 
         FIG.  11    is an enlarged side view (A) showing a side sill stiffener and a center pillar stiffener and a cross-sectional view (B) taken along a line  11 B- 11 B. (second embodiment). 
     
    
    
     EXPLANATION OF REFERENCE NUMERALS 
       12  vehicle body 
       13  front side door 
       14  rear side door 
       15  door 
       15   a  (for front side door) opening 
       15   b  (for rear side door) opening 
       18  roof 
       25  side outer panel 
       25   b  front side sill portion 
       25   c : rear side sill portion 
       26  center pillar 
       27  side sill 
       29  first ridge 
       32  second ridge 
       47  (side sill) upper edge 
       48  front ridge 
       49  (side sill) upper edge 
       51  rear ridge 
       52  base portion 
       53  door hinge mounting area 
       54  receiving body 
       55  first groove 
       56  first bead 
       56   a  swelled bead (outer bead) 
       56   b  recessed bead (inner bead) 
       57  second groove 
       58  second bead 
       58   a  swelled bead (outer bead) 
       58   b  recessed bead (inner bead) 
       61  side outer panel 
       61   b  front side sill portion 
       61   c  rear side sill portion 
       62  auxiliary base portion 
       63  (side sill) upper edge 
       64  front ridge 
       65  (side sill) upper edge 
       66  rear ridge 
       67  front upper wall 
       68  front vertical wall 
       69  third ridge 
       71  front lower wall 
       72  rear upper wall 
       73  rear vertical wall 
       74  fourth ridge 
       75  rear lower wall 
       76  first groove 
       77  first bead 
       77   a  curved surface 
       78  second groove 
       79  second bead 
       79   a  curved surface 
       81  (of first groove) step 
       82  (of second groove) step 
       83  electrodeposition hole 
       84  bead 
       85  side sill inner panel 
       86  side sill stiffener 
       87  center pillar inner panel 
       88  center pillar stiffener 
       88   a  lower end 
     Pf (intersecting first groove) front-rear direction position 
     Pr (intersecting second groove) front-rear direction position 
     PREFERRED MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Here, up, down, front, rear, left, and right of a vehicle body are defined based on a line of sight of an occupant who rides on an automobile four-wheeled vehicle. 
     First Embodiment 
       FIG.  1    schematically shows an entire vehicle according to a first embodiment of the present invention. A vehicle (automobile four-wheeled vehicle)  11  includes a vehicle body  12  that is supported so as to travel freely by left and right front wheels FW and left and right rear wheels FW. The vehicle body  12  includes left and right side panels  16  that define door openings  15  opened and closed by a front side door  13  and a rear side door  14  and a roof  18  that partitions an upper edge of the windshield  17  and connects upper ends of the left and right side panels  16 . As will be described below, the side panel  16  is configured by a combination body of a plurality of structures (panels). The side panel  16  includes left and right front side panels  21  that partition side edges of a bonnet  19  spreading forward from a front edge of the windshield  17  to form left and right, outer surfaces above the front wheels FW, front pillars  22  that partition side edges of the windshield  17 , roof side rails  23  that are continuous from rear ends of the front pillars  22  and are coupled to side edges of the roof  18 , and rear side panels  24  that are continuous from rear ends of the roof side rails  23  and partition a side end of a gate opening opened and closed by a rear gate to form left and right outer surfaces above the real wheels RW. When the front side door  13  and the rear side door  14  are opened, an occupant can get on and off the interior space. An outer surface of the front pillar  22 , an outer surface of the roof side rail  23 , and an outer surface of the rear side panel  24  are formed of a side outer panel  25  molded from one steel plate. 
     As shown in  FIG.  2   , the side panel  16  further includes a center pillar  26  that is located at a boundary between the front side door  13  and the rear side door  14  and extends downward from the roof  18  and a side sill  27  that extends linearly in a front-rear direction (in a horizontal direction) and partitions a lower end of the door opening  15  opened and closed by the front side door  13  and the rear side door  14 . A lower end of the center pillar  26  is coupled to the side sill  27 . The side outer panel  25  is continuous to the outer surface of the front pillar  22 , the outer surface of the roof side rail  23 , and the outer surface of the rear side panels  24  to form an outer surface of the center pillar  26  and an outer surface of the side sill  27 . 
     A center pillar portion  25   a  of the side outer panel  25  includes; a side wall  28  that extends in an up-down direction from the roof side rail  23  to the side sill  27  at a position facing the outer face of the side inner panel; a front wall  31  that is formed by bending from a front end of the side wall  28  to form a first ridge  29  between the front wall  31  and the side wall  28 ; and a rear wall  33  that is formed by bending from a rear end of the side wall  28  to form a second ridge  32  between the rear wall  33  and the side wall  28 . An inner end of the front wall  31  is connected with a front, overlap space  34  that is formed by bending forward from the inner end of the front wall  31  to form a ridge with the front wall  31  and is overlapped with the side inner panel. In this way, the front wall  31  is joined to the side inner panel with the front overlap space  34 . For example, welding can be used for joining. Similarly, an inner end of the rear wall  33  is connected with a rear overlap space  35  that is formed by bending rearward from the inner end of the rear wall  33  to form a ridge with the rear wall  33  and is overlapped with the side inner panel. In this way, the rear wall  33  is joined to the side inner panel with the rear overlap space  35 . For example, welding can be used for joining. 
     The side outer panel  25  includes: a front side sill portion  25   b  that extends forward in the horizontal direction from the center pillar portion  25   a  and forms an outer surface of the side sill  27  in front of the center pillar  26 ; and a rear side sill portion  25   c  that extends rearward in the horizontal direction from the center pillar portion  25   a  and forms an outer surface of the side sill  27  behind the center pillar  26 . The first ridge  29  is continuous with a ridge of the front side sill portion  25   b  while being curved from the center pillar  26  and extends linearly in the front-rear direction (horizontal direction) at the front side sill portion  25   b . An opening  15   a  for the front side door  13  is partitioned by the first ridge  29 . The second ridge  32  is continuous with a ridge of the rear side sill portion  25   c  while being curved from the center pillar  26  and extends linearly in the front-rear direction (horizontal direction) at the rear side sill portion  25   c . An opening  15   b  for the rear side door  14  is partitioned by the second ridge  32 . 
     The front side sill portion  25   b  includes: a front upper wall  41  that extends continuously from the front wall  31  of the center pillar portion  25   a  to surround the opening  15   a  for the front side door  13 ; a front vertical wall  42  that spreads along a vertical plane by being bent downward from an outer end of the front upper wall  41  and defines the first ridge  29  between the front vertical wall  42  and the front upper wall  41 ; and a front lower wall  43  that is bent toward the interior space from a lower end of the front vertical wall  42  and defines the ridge between the front lower wall  43  and the front vertical wall  42 . 
     The rear side sill portion  25   c  includes: a rear upper wall  44  that extends continuously from the rear wall  33  of the center pillar portion  25   a  to surround the opening  15   b  for the rear side door  14 ; a rear vertical wall  45  that spreads along a vertical plane by being bent downward from an outer end of the rear upper wall  44  and defines the second ridge  32  between the rear vertical wall  45  and the rear upper wall  44 ; and a rear lower wall  46  that is bent toward the interior space from a lower end of the rear vertical wall  45  and defines the ridge between the rear lower wall  46  and the rear vertical wall  45 . The rear lower wall  46  and the front lower wall  43  are continuous as one lower wall of the side sill  27 . 
     As shown in  FIG.  3   , the side outer panel  25  includes a base portion  52  that swells from the outer surface, enters the side sill  27  from the center pillar  26 , and forms the front ridge  43  extending along the first ridge  29  of the center pillar portion  25   a  and crossing an upper edge  47  of the front side sill portion  25   b  and the rear ridge  51  extending along the second ridge  32  of the center pillar portion  25   a  and crossing an upper edge  49  of the rear side sill portion  25   c . The upper edge  47  of the front side sill portion  25   b  corresponds to the upper end of the front vertical wall  42 . The upper edge  49  of the rear side sill portion  25   c  corresponds to the upper end of the rear vertical wall  45 . Here, the base portion  52  is partitioned by a contour line  52   a  extending in the horizontal direction below the door hinge area  53  to which a door hinge of the rear side door  14  is mounted. The base portion  52  forms a receiving body  54  that swells in a truncated cone shape from the outer surface at a position closer to the front ridge  43  than the rear ridge  51  and receives a stopper (not shown) of the front side door  13  at a closed position of the front side door  13 . The stopper is formed from an elastic body such as rubber. The receiving body  54  is covered with the front side door  13  at the closed position. 
     The front side sill portion  25   b  includes a first bead  56  that extends in the front-rear direction in front of the base portion  52  and forms a first groove  55  between the first bead  56  and the base portion  52  along the front ridge  48 . A side wall of the first groove  55  is continuous from the front ridge  48 . The first bead  56  includes an inner bead  56   b  that is recessed inward within a bead  56   a  that swells outward. 
     The rear side sill portion  25   c  includes a second bead  58  that extends in the front-rear direction behind the base portion  52  and forms a second groove  57  between the second bead  58  and the base portion  52  along the rear ridge  51 . A side wall of the second groove  57  is continuous from the rear ridge  51 . The second bead  58  includes an inner bead  58   b  that is recessed inward within a bead  58   a  that swells outward. 
     The side outer panel  25  is subjected to painting when the vehicle  11  is manufactured. For example, electrodeposition painting is used for the painting. Since the side outer panel  25  appears on the outer surface of the vehicle  11 , the aesthetic appearance of the vehicle  11  can be established by the behavior of the painting. In the electrodeposition painting, the side outer panel  25  pulled up from a painting liquid is heated. A painting film of the side outer panel  25  is dried by the heating. At this time, the front side sill portion  25   b  and the rear side sill portion  25   c  of the side outer panel  25  are thermally expanded in the front-rear direction based on the heating. Since rigidity of the base portion  52  is ensured by the behavior of the swelling forming the front ridge  48  and the rear ridge  51 , the thermal expansion of the front side sill portion  25   b  and the thermal expansion of the rear side sill portion  25   c  can be absorbed according to the collapse of the first groove  55  and the second groove  57 . Here, when the first groove  55  collapses, the side wall on the base portion continuous from the front ridge  48  and the side wall on the first bead facing the side wall fall down with respect to the bottom wall of the first groove  55 . When the second groove  57  collapses, the side wall on the base portion continuous from the rear ridge  51  and the side wall on the second bead  58  facing the side wall fall down with respect to the bottom wall of the second groove  57 . In this way, the occurrence of permanent strain of the side outer panel  25  can be prevented (avoided) in the side sill  27  below the center pillar  26 . Since only the first groove  55  and the second groove  57  collapse, the visible deformation of the side sill  27  can be prevented (avoided). 
     In the present embodiment, the side wall of the first groove  55  is continuous from the front ridge  48 , and the side wall of the second groove  57  is continuous from the rear ridge  51 . Therefore, when the side outer panel  25  appears on the exterior of the vehicle  11 , the first groove  55  and the second groove  57  are visually integrated with the base portion  52 , and thus the deterioration of the appearance can be prevented regardless of the formation of the first groove  55  and the second groove  57 . 
     In the side outer panel  25  according to the present embodiment, the front side sill portion  25   b  is formed with the first bead  56  extending in the front-rear direction, and the rear side sill portion  25   c  is formed with the second bead  58  extending in the front-rear direction. Thus, since the front side sill portion  25   b  and the rear side sill portion  25   c  are enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove  55  and the second groove  57  while preventing the deformation of the front side sill portion  25   b  and the rear side sill portion  25   c.    
     The first bead  56  and the second bead  53  include the inner beads  56   b  and  53   b  that are recessed inward within the beads  56   a  and  53   a  that swell outward, respectively. Thus, since the front side sill portion  25   b  and the rear side sill portion  25   c  are further enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove  55  and the second groove  57  while preventing the deformation of the front side sill portion  25   b  and the rear side sill portion  25   c.    
     In the present embodiment, the base portion  52  forms the receiving body  54  that swells in the truncated cone shape from the outer surface at the position closer to the first groove  55  than the second groove  57  and receives the stopper of the front side door  13  at the closed position of the front side door  13 . In the base portion  52 , the rigidity can be increased on the side of the first groove  55  as compared with the side of the second groove  57 . Since the stress is concentrated at the central position CT of the side sill  27  in the front-rear direction, the collapse of the first groove  55  can be satisfactorily promoted. 
     Second Embodiment 
       FIG.  4    shows a side panel  16  of a vehicle according to a second embodiment of the present invention. A side outer panel  61  includes a front side sill portion  61   b  that extends forward in a horizontal direction from a center pillar portion  61   a  and forms an outer surface of a side sill  27  in front of a center pillar  26 , and a rear side sill portion  61   c  that extends rearward in the horizontal direction from the center pillar portion  61   a  and forms an outer surface of the side sill  27  behind the center pillar  26 . A first ridge  29  is continuous with a ridge of the front side sill portion  61   b  while being curved from the center pillar  26  and extends linearly in a front-rear direction (horizontal direction) at the front side sill portion  61   b . An opening  15   a  for a front side door  13  is partitioned by the first ridge  29 . A second ridge  32  is continuous with a ridge of the rear side sill portion  61   c  while being curved from the center pillar  26  and extends linearly in the front-rear direction (horizontal direction) at the rear side sill portion  61   c . An opening  15   b  for a rear side door  14  is partitioned by the second ridge  32 . 
     In addition to the above-described base portion  52 , the side outer panel  61  further includes an auxiliary base portion  62  that swells from the outer surface while continuing upward from the base portion  52 , a door hinge area  53  being arranged between the auxiliary base portion  62  and the base portion  52 . As shown in  FIG.  5   , the base portion  52  and the auxiliary base portion  62  form a front ridge  64  extending along the first ridge  23  of the center pillar portion  61   a  and crossing an upper edge  63  of the front side sill portion  61   b . The front ridge  64  is linearly continuous with the base portion  52  and the auxiliary base portion  62 . The base portion  52  and the auxiliary base portion  62  form a rear ridge  66  extending along the second ridge  32  of the center pillar portion  61   a  while bypassing the door hinge area  53  and crossing an upper edge  65  of the rear side sill portion  61   c . The rear ridge  66  is linearly continuous with the base portion  52  and the auxiliary base portion  62 . As described above, the base portion  52  forms a receiving body  54  that swells in a truncated cone shape from the outer surface at a position closer to the front ridge  64  than the rear ridge  66  and receives a stopper (not shown) of the front side door  13  at a closed position of the front side door  13 . 
     The front side sill portion  61   b  includes: a front upper wall  67  that extends continuously from a front wall  31  of the center pillar portion  61   a  to surround the opening  15   a  for the front side door  13 ; a front vertical wall  68  that spreads along a vertical plane by being bent downward from an outer end of the front upper wall  67 ; and defines the first ridge  29  between the front vertical wall  68  and the front upper wall  67 , and a front lower wall  71  that is bent toward the interior space from a lower end of the front vertical wall  68  and defines a third ridge  69  between the front lower wall  71  and the front vertical wall  68 . 
     The rear side sill portion  61   c  includes: a rear upper wall  72  that extends continuously from a rear wall  33  of the center pillar portion  61   a  to surround the opening  15   b  for the rear side door  14 ; a rear vertical wall  73  that spreads along a vertical plane by being bent downward from an outer end of the rear upper wall  72  and defines a second ridge  32  between the rear vertical wall  73  and the rear upper wall  72 ; and a rear lower wall  75  that is bent toward the interior space from a lower end of the rear vertical wall  73  and defines a fourth ridge  74  between the rear lower wall  75  and the rear vertical wall  73 . The rear lower wall  75  and the front lower wall  71  are continuous as one lower wall of the side sill  27 . 
     The front side sill portion  61   b  includes a first bead  77  that extends in the front-rear direction in front of the base portion  52  and forms a first groove  76  between the first bead  77  and the base portion  52  along the front ridge  64 . A side wall of the first groove  76  is continuous from the front ridge  64 . As shown in  FIG.  6   , the first bead  77  includes a curved surface  77   a  that has a generating line extending in a front-rear direction and is curved so as to swell outward. 
     The rear side sill portion  61   c  includes a second bead  79  that extends in the front-rear direction behind the base portion  52  and forms a second groove  78  between the second bead  79  and the base portion  52  along the rear ridge  66 . A side wall of the second groove  78  is continuous from the rear ridge  66 . Like the first bead  77 , the second bead  79  includes a curved surface  79   a  that has a generating line extending in a front-rear direction and is curved so as to swell outward. Here, a structure of the second bead  79  is schematically shown in  FIG.  6    with reference numerals in parentheses. 
     An upper end and a lower end of the first groove  76  are partitioned by steps  81  that are formed on extension lines of an upper edge and a lower edge of the first bead  77 . As shown in  FIG.  7   , the step  81  defines an upper step on the outer surface of the front vertical wall  68  and defines a lower step on the bottom of the first groove  76 . The step  81  may be formed in a plurality of steps, and may define an uppermost step on the outer surface of the front vertical wall  68  and define a lowermost step on the bottom of the first groove  76 . 
     An upper end and a lower end of the second groove  78  are partitioned by steps  82  that are formed on extension lines of an upper edge and a lower edge of the second bead  79 . As shown in  FIG.  8   , the step  82  defines an upper step on the outer surface of the rear vertical wall  73  and defines a lower step on the bottom of the second groove  78 . The step  82  may be formed in a plurality of steps, and may define an uppermost step on the outer surface of the rear vertical wall  73  and define a lowermost step on the bottom of the second groove  78 . 
     As shown in  FIG.  9   , the front lower wall  71  of the front side sill portion  61   b  includes an electrodeposition hole  83  formed at a front-rear direction position Pf intersecting the first groove  76 . The front-rear direction position Pf may be set based on an intersection of the extension line of the first groove  76  and the third ridge  69 . The electrodeposition hole  83  may be arranged at least partially at the front-rear direction position Pf. The electrodeposition hole  83  may be formed so as to cross the front-rear direction position Pf. 
     As shown in  FIG.  10   , the rear lower wall  75  of the rear side sill portion  61   c  includes a bead  84  formed at the front-rear direction position Pr intersecting the second groove  78  and extending orthogonally to the fourth ridge  74 . The bead  84  is formed so as to swell downward from the rear lower wall  75 , for example. The front-rear direction position Pr may be set based on an intersection of the extension line of the second groove  78  and the fourth ridge  74 . The bead  34  may be arranged at least partially at the front-rear direction position Pr. 
     As shown in  FIG.  11   , the side panel  16  includes a side sill stiffener  86  that is joined to the side sill inner panel  85  to form the side sill  27  and a center pillar stiffener  88  that is joined to the center pillar inner panel  37  to form the center pillar  26 . The side sill stiffener  36  is joined to the side sill inner panel  85  to form a tubular hollow structure. Thus, the flexural strength of the side sill  27  is reinforced. The side sill stiffener  86  is covered with the front side sill portion  61   b  and the rear side sill portion  61   c  of the side outer panel  61  joined to the side sill inner panel  85 . The side sill  27  of the side panel  16  is formed by the side sill inner panel  85 , the side sill stiffener  86 , and the side outer panel  61 . 
     The center pillar stiffener  88  is joined to the center pillar inner panel  87  to form a tubular hollow structure. Thus, the flexural strength of the center pillar  26  is reinforced. The center pillar stiffener  88  is covered with the center pillar portion  61   a  of the side outer panel  61  joined to the center pillar inner panel  87 . The center pillar  26  is formed by the center pillar inner panel  87 , the center pillar stiffener  88 , and the side outer panel  62 . The center pillar inner panel  87  and the side sill inner panel  85  may be formed from one continuous steel plate. 
     The center pillar stiffener  88  includes a lower end  83   a  partitioned in the front-rear direction at the first groove  76  and the second groove  78 . The center pillar stiffener  88  is coupled to the side sill stiffener  86  at the lower end  88   a . For example, welding can be used for coupling. The center pillar stiffener  88  overlaps with the side sill stiffener  86 , and thus the flexural strength of the side sill  27  can be further increased in the front-rear direction. 
     The side outer panel  61  is subjected to painting when the vehicle  11  is manufactured. For example, electrodeposition painting is used for the painting. In the electrodeposition painting, the side outer panel  61  pulled up from a painting liquid is heated. A painting film of the side outer panel  61  is dried by the heating. At this time, the front side sill portion  61   b  and the rear side sill portion  61   c  of the side outer panel  61  are thermally expanded in the front-rear direction based on the heating. Since rigidity of the base portion  52  and the auxiliary base portion  62  is ensured by the behavior of the swelling forming the front ridge  64  and the rear ridge  66 , the thermal expansion of the front side sill portion  61   b  and the thermal expansion of the rear side sill portion  61   c  can be absorbed according to the collapse of the first groove  76  and the second groove  78 . Here, when the first groove  76  collapses, the side wall on the base portion continuous from the front ridge  64  and the side wall on the first bead facing the side wall fall down with respect to the bottom wall of the first groove  76 . When the second groove  78  collapses, the side wall on the base portion continuous from the rear ridge  66  and the side wall on the second bead facing the side wall fall down with respect to the bottom wall of the second groove  78 . In this way, the occurrence of permanent strain of the side outer panel  61  can be prevented (avoided) in the side sill  27  below the center pillar  26 . Since only the first groove  76  and the second groove  78  collapse, the visible deformation of the side sill  27  can be prevented (avoided). 
     In the present embodiment, the side wall of the first groove  76  is continuous from the front ridge  64 , and the side wall of the second groove  73  is continuous from the rear ridge  66 . Therefore, when the side otter panel  61  appears on the exterior of the vehicle  11 , the first groove  76  and the second groove  73  are visually integrated with the base portion  52 , and thus the deterioration of the appearance can be prevented regardless of the formation of the first groove  76  and the second groove  78 . 
     In the side outer panel  61  according to the present embodiment, the front side sill portion  61   b  is formed with the first bead  77  extending in the front-rear direction, and the rear side sill portion  61   c  is formed with the second bead  79  extending in the front-rear direction. Thus, since the front side sill portion  61   b  and the rear side sill portion  61   c  are enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove  76  and the second groove  78  while preventing the deformation of the front side sill portion  61   b  and the rear side sill portion  61   c.    
     The first bead  77  and the second bead  79  according to the present embodiment include the curved surfaces  77   a  and  79   a  that have a generating line extending in the front-rear direction and are curved so as to swell outward, respectively. Since the front side sill portion  61   b  and the rear side sill portion  61   c  are enhanced in flexural rigidity in the front-rear direction, it is possible to promote the collapse of the first groove  76  and the second groove  78  while preventing the deformation of the front side sill portion  61   b  and the rear side sill portion  61   c . Moreover, since the first bead  77  and the second bead  79  form the curved surfaces  77   a  and  79   a  that swell outward, respectively, the first bead  77  and the second bead  79  can be satisfactorily visually recognized from a line of sight looking downward of the occupant getting on and off. The existence of the vertical wall can be confirmed. Designability can be ensured. When the vertical wall of the bead is hidden from the line of sight looking downward of the occupant, the occupant misunderstands that the vertical wall is missing. It becomes a design that makes feel instability of the structure. 
     In the side outer panel  61  according to the present embodiment, the upper end and the lower end of the first groove  76  are partitioned by the steps  81  that are formed on the extension lines of the upper edge and the lower edge of the first bead  77 , respectively, and the upper end and the lower end of the second groove  78  are partitioned by the steps  82  that are formed on the extension lines of the upper edge and the lower edge of the second bead  79 , respectively. The depth of the first groove  76  and the second groove  78  can be increased by the behavior of the steps  81  and  82 . Deformation of the first groove  76  and the second groove  78  can be promoted when the first groove  76  and the second groove  78  are deepened. Moreover, since the steps  81  and  82  extend in the straight line from the first bead  77  and the second bead  79 , a complicated uneven shape can be reduced and the appearance can be satisfactorily ensured. 
     In the present embodiment, the front lower wall  71  of the front side sill portion  61   b  includes the electrodeposition hole  83  formed at the front-rear direction position Pf intersecting the first groove  76 . Since the strength of the front lower wall  71  is weakened at the front-rear direction position Pf intersecting the first groove  76  by the behavior of the electrodeposition hole  83 , the deformation of the bottom wall can be promoted in the first groove  76  in addition to the fall of the side wall. The collapse of the first groove  76  can be further accelerated. In this way, the thermal expansion of the front side sill portion  61   b  can be absorbed. In the side sill  27 , the occurrence of the permanent strain of the side outer panel  61  can be prevented (avoided). 
     In the present embodiment, the rear lower wall  75  of the rear side sill portion  61   c  includes the bead  84  that is formed at the front-rear direction position Pr intersecting the second groove  78  and extends orthogonally to the fourth ridge  74 . The bead  84  can prevent spring-back between the rear vertical wall  73  and the rear lower wall  75  at the time of molding the side outer panel  61 . Although the bead  84  is formed on the rear lower wall  75  at the front-rear direction position Pr intersecting the second groove  78 , a stress is concentrated at a central position of the side sill  27  in the front-rear direction, the stress concentrated in this way is absorbed by the first groove  76 , and the second groove  78  on the rear side plays a complementary role, whereby the bead  84  does not hinder the prevention of the thermal expansion. 
     The side outer panel  61  includes the auxiliary base portion  62  that swells from the outer surface while continuing upward from the base portion  52 , the door hinge area  53  being arranged between the auxiliary base portion  62  and the base portion  52 . Since the base portion  52  and the auxiliary base portion  62  are continuous so as to surround the door hinge area  53 , it is possible to reduce a complicated uneven shape and further improve the appearance. Such simplification of the uneven shape can prevent the occurrence of wrinkles during a pressing process of the side outer panel  61 . Moreover, since the rigidity of the base portion  52  is further increased due to the addition of the auxiliary base portion  62 , the absorption of thermal expansion can be further promoted in the first groove  76  and the second groove  78 . 
     In the present embodiment, the base portion  52  forms the receiving body  54  that swells in the truncated cone shape from the outer surface at the position closer to the first groove  76  than the second groove  78  and receives the stopper of the front side door at the closed position of the front side door. In the base portion  52 , the rigidity can be increased on the side of the first groove  76  as compared with the side of the second groove  78 . Since the stress is concentrated at the central position of the side sill  27  in the front-rear direction, the collapse of the first groove  76  can be satisfactorily promoted. 
     The center pillar stiffener  88  according to the present embodiment is coupled to the side sill stiffener  86  at the lower end  88   a  partitioned in the front-rear direction at the first groove  76  and the second groove  78 . During a side collision, the impact acting on the center pillar stiffener  88  is supported by the side sill  27  coupled to the lower end  88   a  of the center pillar stiffener  88 . At this time, since the first groove  76  and the second groove  78  are arranged at the edge of the center pillar stiffener  88 , the first groove  76  and the second groove  78  do not affect the collision performance during the side collision.