Abstract:
A vehicle body includes a side sill connected by overlapping a plurality of plates. In an area of the side sill positioned in a door opening, a step garnish covers at least a portion of such area. The step garnish is formed of a hard resin garnish main body and a soft resin garnish end part. The garnish main body covers from the upper surface of the side sill through a lateral surface that includes a sealing contact part. The garnish end part is integrally formed with an end of the garnish main body, and covers at least the sealing contact part. The thickness of the garnish end part gradually decreases from a proximal end formed integrally with the garnish main body towards the distal end. Such arrangement improves appearance of the door opening and sealing characteristics of the area surrounding the door opening.

Description:
TECHNICAL FIELD 
     The present invention relates to an improvement of a technique for covering the lower edge of a door opening, formed in a side section of a vehicle body, with a step garnish. 
     BACKGROUND ART 
     Door openings to be opened and closed by side doors are formed in side sections of ordinary vehicles, such as passenger automobiles. Generally, the lower edge of such a door opening is set at a low height to allow a passenger to get in and out of the vehicle with ease. The lower edge of the door opening is defined, for example, by the upper surface of a side sill. A construction of a side sill is disclosed, for example, in Patent Literature 1. Further, a technique for covering the lower edge of a door opening with a step garnish is disclosed, for example, in Patent Literature 2. 
     A vehicle body disclosed in Patent Literature 1 is constructed of plate materials differing among various portions of the vehicle body and such different plate materials are joined together, in order to achieve an enhanced quality and reduced weight. For example, lower end portions of a center pillar and a rear pillar are lapped over and joined to a side sill. Namely, a part of the side sill is constructed by the plate materials, forming the center pillar and the rear pillar, being lapped over the plate material forming the side sill. Thus, the side sill has a stepped joint section where the plate materials are lapped over and joined to each other. 
     Generally, a seal member is provided on the peripheral edge of the vehicle door. With the door in a closed position, the seal member contacts and seals an outer side surface, located outward in a vehicle width direction, of the side sill. If the side sill has a joint section as in the vehicle body disclosed in Patent Literature 1, the joint section would adversely influence the sealing performance of the sealing member. Further, in the case where the lower edge of the door opening is defined by the upper surface of the side sill and if the joint section is exposed on the upper surface of the side sill, the joint section is undesirably visible from outside. Therefore, a further improvement has to be made in order to enhance the outer appearance of the vehicle body. 
     Further, a vehicle body disclosed in Patent Literature 2 has a step plate (step garnish) provided on the lower edge of the door opening. The step plate is an aluminum plate constructed to allow a foot (or feet) of a passenger to be placed thereon and covered along its outer periphery with a decorative resin cover. Such a decorative resin cover can enhance the outer appearance of the step plate. 
     Further, merely combining the technique disclosed in Patent Literature 2 with the technique disclosed in Patent Literature 1 cannot enhance the sealing performance provided by the seal member in the joint section of the side sill, nor can it enhance the outer appearance of the lower edge of the door opening. 
     PRIOR ART LITERATURE 
     
         
         Patent Literature 1 Japanese Patent Application Laid-Open Publication No. 2011-195107 
         Patent Literature 2: Japanese Patent Application Laid-Open Publication No. H11-310083 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     It is therefore an object to provide a technique which is applied to a vehicle body including a side sill having a joint section where a plurality of plate materials are lapped over and joined to each other and which can enhance sealing performance along the periphery of a door opening. 
     Solution to Problem  
     According to claim  1  of the instant application, there is provided an improved vehicle side body structure including: a side sill provided in a lower portion of a side section of a vehicle body and extending in a front-rear direction of the vehicle body; and a door opening formed in the side section of the vehicle body; the lower edge of the door opening being defined by the upper surface of the side sill, the side sill having a joint section where a plurality of plate materials are lapped over and joined to each other, the door opening being opened and closed by a door having a door seal member on the lower edge portion of the door, wherein, when the door is in a closed position, the door seal member seals the door by contacting a seal contact portion on an upper portion of an outer side surface, located outward in a vehicle with direction, of the side sill, characterized in that a step garnish is provided on a portion of the side sill adjacent to the door opening, the step garnish covering at least a part of the portion of the side sill in such a manner as to allow a foot of a passenger to be placed thereon, the step garnish is an integrally-molded member including a garnish body formed of hard resin and a garnish end section formed of soft resin, the garnish body covers a region from the upper surface of the side sill to the upper portion of the side surface including the seal contact portion and covers the joint section as well, the garnish end section is formed integrally with an end, in the front-rear direction of the vehicle body, of the garnish body and covering at least the seal contact portion, a thickness of the garnish end section gradually decreases from the proximal end thereof formed integrally with the garnish body toward the distal end thereof. 
     Preferably in the invention recited in claim  2 , a thickness of the garnish body gradually decreases in such a manner that the thickness gradually decreases continuously from a middle portion of the garnish body to the distal end of the garnish end section. 
     Preferably, in the invention recited in claim  3 , before being mounted on the side sill, the step garnish is curved in a given direction such that a middle portion thereof is spaced from the upper surface and the side surface of the side sill, so that, when the step garnish is mounted on the side sill, an edge of the step garnish resiliently contacts the upper surface and the side surface of the side sill. 
     Preferably, in the invention recited in claim  4 , of a distal end part of the garnish end section, a portion contacting the upper surface of the side sill has a greater thickness than a portion contacting the seal contact portion. 
     Preferably, in the invention recited in claim  5 , of the outer side surface, located outward in the vehicle with direction, of the side sill, a portion not covered with the garnish body is covered with a side sill garnish, and wherein the garnish body has a lower flange extending outward in the vehicle width direction from the lower end of a side wall, covering the side surface of the side sill, along the upper surface of the side sill garnish, and the lower flange is placed on the upper surface of the side sill garnish. 
     Preferably, in the invention recited in claim  6 , an opening seal member is provided on the lower edge of the door opening, and the opening seal member is a member for sealing the door by the lower edge of the inner surface of the door contacting the opening seal member when the door is in the closed position. The garnish body has an upper flange extending upward from the inner end, in the vehicle width direction, of an upper wall covering the upper surface of the side sill, and the upper end of the upper flange is located near the lower end of the opening seal member. 
     Advantageous Effects of Invention 
     In the invention recited in claim  1 , the step garnish is an integrally-molded member and the garnish end section. The garnish body covers the region from the upper surface of the side sill to the upper portion of the side surface including the seal contact portion and covers the joint section as well. The joint section, where at least two plate materials are lapped over and joined to each other, constitutes a part of the side sill. The joint section of a stepped shape (stepped joint section) located on the lower edge of the door opening is covered with the garnish body, so that the present invention can achieve an enhanced outer appearance of the lower edge of the door opening. Besides, because the garnish body is formed of hard resin, it has rigidity great enough to allow a foot (or feet) of a passenger to be placed on the garnish body. 
     The upper portion of the outer side surface, located outward in the vehicle with direction, of the side sill is covered with the garnish body. A level difference corresponding to the thickness of the garnish body is formed between an end, in the front-rear direction of the vehicle body, of the garnish body and the upper portion of the side surface of the side sill. By contrast, the garnish end section is formed of soft resin and thus has considerable flexibility. Besides, the thickness of the garnish end section gradually decreases from the proximal end, formed integrally with the garnish body, toward the distal end. Namely, the garnish end section is formed integrally with one of the ends, in the front-rear direction of the vehicle body, of the garnish body and covers at least the seal contact portion. Namely, the garnish end section has a gently sloping shape so as to avoid formation of a level difference. Thus, no gap is left between the upper portion of the outer side surface of the side sill and the door seal member. As a result, the present invention can enhance sealing performance between the door opening and the door. 
     With the aforementioned arrangements, the invention of claim  1  can not only enhance the outer appearance of the lower edge of the door opening but also enhance the sealing performance along the periphery of the door opening. 
     In the invention recited in claim  2 , the thickness of the garnish body gradually decreases continuously from the middle portion of the garnish body to the distal end of the garnish end section. Namely, the thickness of the garnish body is smaller at the end in the front-rear direction of the vehicle body than at the middle portion. Thus, the thickness of the proximal end of the garnish end section can be reduced by an amount corresponding to the reduced thickness of that end in the front-rear direction. Further, a length of the garnish end section from the proximal end to the distal end can be reduced by an amount corresponding to the reduced thickness of the proximal end. Because of the reduced length of the garnish end section, it is possible to fill molten resin evenly into a cavity of a mold for forming the garnish end section on the garnish body. Because the molten resin can be filled into the mold cavity in an appropriate manner like this, it is possible to achieve an enhanced quality of the garnish end section. 
     Further, in the invention recited in claim  3 , the step garnish is formed of resin so that it is resiliently deformable. Before being mounted on the side sill, the step garnish is curved in the given direction such that its middle portion is spaced from the upper surface and the side surface of the side sill. The middle portion of the step garnish is lapped over the upper surface and side surface of the side sill by being placed over the upper surface and side surface of the side sill and pressed against the resiliency of the step garnish. The step garnish is mounted on the side sill in the aforementioned state. With the step garnish mounted on the side sill, the distal end of the garnish end portion is resiliently pressed against, the upper surface and side surface of the side sill and thus can be kept in close contact with the upper surface and side surface with no gap left between the distal end of the garnish end section and the upper surface and side surface. With no gap between the distal end of the garnish end section and the upper surface and side surface, it is possible to even further enhance the outer appearance of the lower edge of the door opening and the sealing performance along the periphery of the door opening. 
     Further, in the invention of claim  4 , of the distal end part of the garnish end section, the portion contacting the upper surface of the side sill has a greater thickness than the portion contacting the seal contact portion. Namely, the portion of the garnish end section contacting the seal contact portion has a smaller thickness such that no gap is left between that portion and the door seal member. The potion contacting the upper surface of the side sill, on the other hand, may be formed to have a greater thickness than the portion of the garnish end section contacting the door seal member, because the potion contacting the upper surface of the side sill it is provided only for the purpose of enhancing the outer appearance of the lower edge of the door opening. Because the potion contacting the upper surface of the side sill has a greater thickness, it is possible to fill molten soft resin evenly into a portion, corresponding to the distal end, of the mold cavity. Because the molten resin can be filled into the mold cavity in a more appropriate manner as noted above, the present invention can achieve an enhanced overall quality of the garnish end section. As a result, the present invention can even further enhance an overall rigidity of the garnish end section. 
     Further, in the invention of claim  5 , of the outer side surface, located outward in the vehicle with direction, of the side sill, the portion not covered with the garnish body is covered with the side sill garnish. The garnish body has the lower flange extending outward in the vehicle width direction from the lower end of the side wall, covering the side surface of the side sill, along the upper surface of the side sill garnish, and the lower flange is placed on the upper surface of the side sill garnish. Because frictional resistance is produced between the lower flange and the upper surface of the side sill garnish, the side wall of the garnish body can be prevented from deforming laterally outwardly in the vehicle width direction. Besides, because the lower, flange extends outward in the vehicle width direction from the lower end of the side wall and is placed on the upper surface of the side sill garnish, a gap, if any, between the lower end of the side wall and the upper surface of the side sill garnish is hardly visible, and thus, the present invention can even further enhance the outer appearance of the lower edge of the door opening. 
     Further, in the invention of claim  6 , the garnish body has the upper flange extending upward from the inner end, in the vehicle width direction, of the upper wall covering the upper surface of the side sill, and the upper end of the upper flange is located near the lower end of the opening seal member provided on the lower edge of the door opening. When the door is closed, the opening seal member contacts the upper end of the upper flange while elastically deforming to collapse. Because the opening seal member is prevented from deforming downward by contacting the upper end of the upper flange, contact pressure between the opening seal member and the lower edge of the inner surface of the door increases. As a consequence, sealability between the lower edge of the inner surface of the door and the opening seal member increases so that waterproofness and sound insulation can be significantly increased. Particularly, when the door is in the closed position, it is possible to sufficiently secure double sealing by the door seal member and the opening seal member and thereby achieve a further increased waterproofness and sound insulation. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view showing a door and other components around the door in a side section of a vehicle body of an automobile according to an embodiment of the present invention; 
         FIG. 2  is a side view of the vehicle body shown in  FIG. 1 ; 
         FIG. 3  is a sectional view taken along line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a perspective view of a construction where a side sill garnish and a step garnish are mounted on a side sill shown in  FIG. 2 ; 
         FIG. 5  is an enlarged view showing principal sections of the step garnish shown in  FIG. 4 ; 
         FIG. 6  is a view taken in the direction of arrow  6  of  FIG. 4 ; 
         FIG. 7  is a view showing a construction with the side sill garnish removed from the side sill shown in  FIG. 6 ; 
         FIG. 8  is a view showing a construction with the step garnish removed from the side sill shown in  FIG. 7 ; 
         FIG. 9  is a view taken in the direction of arrow  9  of  FIG. 4 ; 
         FIG. 10  is a bottom view of the step garnish shown in  FIG. 9 ; 
         FIG. 11  is a sectional view taken along line  11 - 11  of  FIG. 7 ; 
         FIG. 12  is a sectional view taken along line  12 - 12  of  FIG. 3 ; and 
         FIG. 13  is a sectional view taken along line  13 - 13  of  FIG. 9 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Now, preferred embodiments of a structure for vehicle body lateral section (i.e., vehicle side body structure) of the present invention will be described hereinbelow with reference to the accompanying drawings. 
     As shown in  FIGS. 1 and 2 , an automobile  10  (vehicle  10 ) is a so-called four-door automobile or vehicle including left and right front doors  21  and left and right rear doors  22  on a vehicle body  11 . 
     The vehicle body  11  includes left and right side sills  12 , left and right front pillars  13 , left and right center pillars  14 , left and right rear pillars  15 , and left and right roof side rails  16 . The left and right side sills  12  are provided on left and right side sections of the vehicle body  11  and extend in a front-rear direction of the vehicle body  11 . The left and right front pillars  13  extend upward from front end portions of the left and right side sills  12 . The left and right center pillars  14  extend upward from longitudinal halfway portions of the left and right side sills  12 . The left and right rear pillars  15  extend upward from rear end portions of the left and right side sills  12 . The left and right roof side rails  16  are secured to and extend between the upper ends of the left and right front pillars  13 , the left and right center pillars  14  and the left and right rear pillars  15 . 
     As shown in  FIG. 2 , the vehicle body  11  is constructed of plate materials differing among various portions of the vehicle body  11  and such different plate materials are joined together, in order to achieve an enhanced quality and reduced weight of the vehicle body. For example, lower end portions of the left and right center pillars  14  and lower end portions of the left and right rear panels  17  are lapped over and joined to the left and right side sills  12 . Namely, parts of the left and right side sills  12  are constructed by the plate materials, forming the left and right center pillars  14  and the left and right rear pillars  15 , being lapped over the plate materials forming the left and right side sills  12 . Thus, the left and right side sills  12  have stepped joint sections  31  where the plate materials are lapped over and joined to each other. 
     The following describe the left side sill  12 . Because the right side sill  12  is of the same construction as the left side sill  12  except that it is shaped in left-right symmetric relation to the left side sill  12 , description about the right side sill  12  is omitted here. 
     As shown in  FIGS. 2 and 3 , the left side sill  12  has a substantially rectangular closed sectional shape uniform throughout its length in the front-rear direction of the vehicle body  11 . Namely, the side sill  12  is a closed-sectional member having an inner side sill element  32  disposed inward in a vehicle width direction and an outer side sill element  33  disposed outward in the vehicle width direction. 
     Each of the inner side sill element  32  and the outer side sill element  33  has a generally hat-like sectional shape. More specifically, the inner side sill element  32  is formed in a substantially U shape opening outward in the vehicle width direction, and it integrally has an upper flange  34  extending upward from the upper end of the U-shape opening and a lower flange  35  extending downward from the lower end of the U-shape opening. The outer side sill element  33  is formed in a substantially U shape opening inward in the vehicle width direction, and it integrally has an upper flange  34  extending upward from the upper end of the opening and a lower flange  35  extending downward from the lower end of the opening. The side sill  12  is constructed by the upper flanges  34  of the inner and outer elements  32  and  33  being joined to each other and the lower flanges  35  of the inner and outer elements  32  and  33  being joined to each other. 
     The outer surface of the side sill  12  of a substantially rectangular closed sectional shape constructed in the aforementioned manner comprises four surfaces: a substantially horizontal, flat upper surface  36 ; a substantially horizontal, flat lower surface  37 ; a side surface  38  (outer surface  38 ) located outward in the vehicle width direction and extending substantially flatly and perpendicularly to the upper surface  36 ; and a side surface  39  (inner surface  39 ) located inward in the vehicle width direction and extending substantially flatly and perpendicularly to the upper surface  36 . The lower flanges  35  extend downward from a widthwise middle portion of the lower surface  37 . 
     As shown in  FIG. 2 , left and right front door openings  41  and left and right rear door openings  42  are formed in the left and right side sections of the vehicle body  11 . These door openings  41  and  42  are each an entrance/exit opening for a passenger to get in and out of the vehicle. The lower edge of each of the door openings  41  and  42  is set at a low height to allow the passenger to get in and out of the vehicle with ease. More specifically the lower edge of each of the door openings  41  and  42  (opening&#39;s lower edge) is defined by the upper surface  36  of the left or right side sill  12 . 
     Namely, the left and right front door openings  41  are each an opening surrounded by the left or right side sill  12 , the left or right front pillar  13 , the left or right center pillar  14  and the left or right roof side rail  16 . Further, the left and right rear door openings  42  are each an opening surrounded by the left or right side sill  12 , the left or right center pillar  14 , the left or right rear pillar  15  and the left or right roof side rail  16 . 
     Further, as shown in  FIGS. 1 ,  2  and  3 , an opening seal member (i.e., door opening seal)  43  is provided on and along the peripheral edge of each of the left and right front door openings  41 , and each of the left and right front door openings  41  is opened and closed by a left or right front door  21 . Further, an opening seal member (door opening seal)  44  is provided on and along the peripheral edge of each of the left and right rear door openings  42 , and each of the left and right rear door openings  42  is opened and closed by a left or right rear door  22 . These opening seal members  43  and  44  are each an annular rubber-made member. Namely, the opening seal members  43  and  44  are each an elastic member which, with the corresponding left or right door opening  41  or  42  closed, seals the interior of the vehicle body  11  from the outside by the inner peripheral edge (sealing surface) of the door  21  or  22  contacting the opening seal member  43  or  44 . 
     Further, a seal contact portion (seal surface)  45  is formed along the peripheral edge of each of the left and right front door openings  41  so as to surround the outer periphery of the opening seal member  43 . Similarly, a seal contact portion (seal surface)  46  is formed along the peripheral edge of each of the left and right rear door openings  42  so as to surround the outer periphery of the opening seal member  43 . These seal contact portions  45  and  46  are each in the form of an annular flat surface formed along the peripheral edge of the corresponding door opening  41  or  42 . 
     Each of the left and right front doors  21  is openably/closably mounted on the corresponding left or right front pillar  13  via not-shown hinges, and each of the left and right rear doors  22  is openably/closably mounted on the corresponding left or right center pillar  14  via not-shown hinges. 
     The following describe in detail the left rear door (side door)  22 . Because the right rear door  22  is of the same construction as the left rear door  22  except that it is shaped in left-right symmetric relation to the left rear door  22 , description about the right rear door  22  is omitted here. Further, because the left and right front doors (side doors)  21  are of generally the same construction as the left rear door  22  except that they differ in overall shape from the left rear door  22 , description of the left and right front doors  22  is omitted here. 
     As shown in  FIG. 3 , the left door  22  is a hollow member comprising an outer door panel  23  and an inner door panel  24 . A peripheral edge section  25  of the door  22  is formed by the edges of the outer and inner door panels  23  and  24  being joined to each other. A door seal member  26  is provided in the peripheral edge section  25  of the door  22 . 
     The door seal member  26  is a rubber-made member formed in an annular shape along the peripheral edge of the door opening  42 , and it is slightly greater in diameter than the opening seal member  44 . Namely, the door seal member  26  is disposed so as to surround the outer periphery of the opening seal member  44 , and this door seal member  26  is an elastic member which, with the door opening  42  closed with the door  22 , seals the door by contacting a sealing contact portion  46  of the door opening  42 . With the door opening  42  closed with the door  22 , the peripheral edge of the door opening  42  is sealed doubly with the opening seal member  44  and the door seal member  26 . 
     As stated above, the lower edge of each of the door openings  41  and  42  (opening&#39;s lower edge) is defined by the upper surface  36  of the left or right side sill  12 . The left and right side sills  12  each have the stepped joint section  31  where the plate materials are lapped over and joined to each other. Thus, regions where such joint sections  31  overlap or traverse the seal contact portions  46  have level differences. Further, the stepped joint sections  31  on the side sills  12  would adversely influence the sealing performance of the door seal members  26 . Furthermore, because the lower edges of the door openings  42  are defined by the upper surfaces  36  of the side sills  12 , the joint sections  31  are visible from the outside if exposed on the upper surfaces  36 , thus adversely influencing the sealing performance 
     To avoid such inconveniences, the instant embodiment includes a step garnish  50  provided on a portion of each of the side sills  12  adjacent to the corresponding door opening and covering at least, a part of the portion of the side sill  12 . The passenger can put its foot (feet) on the step garnish  50 . The following describe in more detail the step garnish  50 . 
     As shown in  FIG. 4 , the step garnish  50  is provided in such a manner as to cover the upper surface  36  of the side sill  12  and an upper portion of the outer side surface  38  located outward in the vehicle width direction. The step garnish  50  is an integrally-molded member that comprises a garnish body  51  and garnish end portions formed of soft resin. The step garnish  50  extends along the lower edge of the door opening  42  and covers the joint section  31  on the upper surface  36  of the side sill  12  and the joint section  31  on the side surface  38 . Because these joint sections  31  are invisible from the outside by being covered with the step garnish  50 , the outer appearance of the vehicle body  11  can be enhanced. 
     The side surface  38  of the side sill  12  beneath the step garnish  50  is covered with a side sill garnish  70  laterally from outside in the vehicle width direction. The side sill garnish  70  is a member extending along the side sill  12  beneath the door opening  41  or  42  to a portion beneath the center pillar  14 . 
     Further, as shown in  FIGS. 3 and 4 , the garnish body  51  includes: an upper wall  53  covering the upper surface  36  of the side sill  12 ; a side wall  54  extending from the outer end, in the vehicle width direction, of the upper wall  53 ; a lower flange  55  extending outward in the vehicle width direction from the lower end of the side wall  54 ; and an upper flange  56  extending upward from the inner end, in the vehicle width direction, of the upper wall  53 . The upper flange  56  has an upper bent portion  57  bent inward, in the vehicle width direction, from its upper end portion. 
     When the door  22  is in the closed position, the opening seal member  44  also contacts the upper bent portion  57  of the upper flange  56  to elastically deform and thereby seals between the door  22  and the step garnish  50 , which can achieve an even further enhanced sealability. 
     The side wall  54  covers an upper portion of the side wall  38  of the side sill  12 . The lower flange  55  is placed on and extends along the upper surface  71  of the side sill garnish  70 . With the lower flange  55  placed on the upper surface  71  of the side sill garnish  70  like this, a gap between the side sill garnish  70  and the side sill  12  can be concealed, which can achieve an enhanced outer appearance. Further, because frictional resistance is produced between the lower flange  55  and the upper surface  71  of the side sill garnish  70 , the side wall  54  can be prevented from deforming laterally outwardly in the vehicle width direction due to external force applied to the garnish body  51 , for example, as the door is closed 
     The door seal member  26  is provided in the peripheral edge section  25  of the door  22 . When the door  22  is in the closed position, the door seal member  26  is pressed against and seals the seal contact portion  46  of the side surface  38  located outward in the vehicle width direction, of the side sill  12  and the seal contact portion of the side wall  54  of the step garnish  50 . 
     Whereas the instant embodiment has been described above in relation to the case where the step garnish  50  is provided adjacent to the left rear door opening  42  of the vehicle body  11 , the present invention is not so limited, and such a step garnish  50  may be provided adjacent to all of the left and right front door openings  41  and left and right rear door openings  42  of the vehicle body  11 . 
     Further, as shown in  FIG. 5 , the side sill  12  includes the joint section  31  where two plate materials of the outer side sill element  33  and the rear panel  17  are lapped over and joined to each other. The step garnish  50  is disposed so as to cover the joint section  31 . The garnish body  51  has a plurality of grooves  58  formed in the upper wall  53  and extending in a longitudinal direction of the garnish body  51 . With such grooves  58 , the garnish body  51  can have an increased rigidity. 
     The lower flange  55  is formed at the lower end of the garnish end section  52 , i.e. below the seal contact portion  46 , and integrally with the lower flange  55  of the garnish body  51 . Such a lower flange  55  on the garnish end section  52  has a large thickness although the garnish end section  52  gets smaller and smaller in thickness toward the distal end, and formability of resin can be increased. Further, even though molded of soft resin, a lower end portion of the garnish end section  52  can be increased in rigidity. 
     Further, the upper flange  56  is formed on an upper portion of the garnish end section  52  and integrally with the upper flange  56  of the garnish body  51 , and the upper bent portion  57  is formed at the upper end of the garnish end section  52  and integrally with the upper bent portion  57  of the garnish body  51 . Such an upper flange  56  and upper bent portion  57  on the garnish end section  52  have a large thickness although they get smaller and smaller in thickness toward the distal end of the garnish end section  52 , and formability of resin can be increased. Further, even though molded of soft resin, an upper end portion of the garnish end section  52  can be increased in rigidity. 
     The following describe a state of the vehicle side body structure with the step garnish and the side sill garnish mounted on the side sill. 
     As shown in  FIG. 6 , the side sill garnish  70  is mounted on a side surface of the side sill  12 , and the step garnish  50  is provided on an upper portion of the side sill  12  adjacent to the door opening  42 . The joint sections  31  of the side sill  12  each have an L shape as viewed from a lateral side of the vehicle. An upper portion of each of the joint sections  31  is covered with the step garnish  50  and the opening seal member  44  while a lower portion of each of the joint sections  31  is covered with the side sill garnish  70 , so that the joint sections  31  can be concealed from the outside. 
     The lower flange  55  of the step garnish  50  is placed on the upper surface  71  of the side sill garnish  70  along a longitudinal direction of the side sill garnish  70 . The lower portion of each of the joint sections  31  of the side sill  12  is covered with the side sill garnish  70 . The upper end of the upper flange  56  of the step garnish  50  is located close to the lower end of the opening seal member  44 . 
     The following describe a state of the vehicle side body structure with the side sill garnish removed from the side sill. 
     As shown in  FIG. 7 , the upper portion of each of the joint sections  31  is covered with the step garnish  50 . The side wall  54  of the step garnish  50  is disposed so as to extend continuously with the seal contact portion  46  of the center pillar  14  and the seal contact portion  46  of the rear panel  17 . 
     The following describe a state of the vehicle body structure with the step garnish removed from the side sill. 
     As shown in  FIG. 8 , the side sill  12  has the joint section  31  where the outer side sill element  33  and the center pillar  14  are joined to each other, and the joint section  31  where the outer side sill element  33  and the rear panel  17  are joined to each other. The seal contact portions  46 , which the door seal member  26  contacts when the door  22  ( FIG. 2 ) is closed, are provided on the center pillar  14 , outer side sill element  33  and rear panel  17 , and these seal contact portions  46  extend substantively continuously with one another. 
     The following describe, with reference to a top plan view, a state of the vehicle side body structure with the step garnish mounted on the side sill. 
     As shown in  FIG. 9 , a portion of the upper surface  36  is covered with the upper wall  53  of the step garnish  50 , and a portion of the side surface  38  is covered with the side wall  54  of the step garnish  50 . Further, the inner end, in the vehicle width direction, of the step garnish  50 , is concealed by the opening seal member  44  as viewed in top plan. With such arrangements, dust etc. can be prevented from entering from above a gap between the inner end of the step garnish  50  and the side sill  12 . Further, because the step garnish  50  has substantially the same width, in the vehicle width direction, as the upper surface  36  of the side sill  12 , the passenger can easily place its foot (feet) on the step garnish  50 , which thereby allows the passenger to get in and out of the vehicle with an increased ease. 
     Next, with reference to a bottom plan view, a description will be given about a manner in which the step garnish is mounted. 
     As shown in  FIG. 10 , a seating surface  62  is provided on the reverse surface  61  of the upper wall  53  of the step garnish  50 , and clips  63  are provided on the seating surface  62 . The seating surface  62  has a greater thickness than a portion surrounding the seating surface  62 , so that it has an increased supporting rigidity. Mounting holes (not shown) are formed in the upper surface  36  of the side sill  12  ( FIG. 9 ), and the clips  63  are inserted into these mounting holes so that the step garnish  50  is fixed to the side sill  12 . 
     Note that the reverse surface  61  of the step garnish  50  and the upper surface  36  of the side sill  12  may be bonded together by adhesive. 
     The following describe, with reference to a sectional side view of the side sill, a thickness of the step garnish  50 . 
     As shown in  FIG. 11 , the center pillar  14  is welded to the outer side sill element  33 . The garnish end section  52  is formed integrally with an end  62  of the garnish body  51 . The joint section  31  is hollowed inwardly and covered with the garnish body  51 . 
     The garnish body  51  has a thickness L 0  at a middle portion thereof, a thickness L 1  at a portion thereof near the joint section  31 , and a thickness L 2  at the end  62  of the garnish end section  52 . Further, the garnish end section  52  has a thickness L 3  at a portion thereof near the end  62  and a thickness L 4  at its distal end. 
     The thickness of the garnish end section  52  gradually decreases from the end  62  of the garnish end section  52  toward the distal end, and the thickness of the garnish body  51  gradually decreases continuously from a middle portion of the garnish body  51  toward the distal end of the garnish end section  52 , namely, L 4 &lt;L 3 , L 3 =L 2 , L 2 &lt;L 1 &lt;L 0 . 
     Because not only the garnish end section  52  but also the garnish body  51  is formed to gradually decrease in thickness toward the distal end, the thickness of the end  62  of the garnish body  51  can be made smaller than the thickness of the middle portion of the garnish body  51 , and the thickness L 3  of a proximal end portion of the garnish end section  52  can be made small. Thus, it is possible to reduce a length S from the end  62  to the distal end of the garnish end section  52 . 
     Further, the step garnish  50  depicted by imaginary line in  FIG. 11  is in a state before being mounted on the side sill  12 , and it is curved in a given direction such that a longitudinally middle portion thereof is spaced apart from the side surface  38  of the side sill  12 . The step garnish  50  depicted by solid line in  FIG. 11 , on the other hand, is in a state having been duly mounted on the side sill  12 , and its edge is kept in resilient contact with the side surface  38  of the side sill  12 . Thus, the garnish end section  52  can be kept in close contact with the side surface  38  of the side sill  12 . 
     The door  22  depicted by imaginary line in  FIG. 11  is closed by being moved as indicated by an arrow. Note that the door seal member  26  depicted by imaginary line closely contacts the rear seal contact portion  46 . 
     Next, a description will be given about a state of the vehicle side body structure when the door is the closed position. 
     As shown in  FIG. 12 , the step garnish  50  and the side sill  12  are connected smoothly; namely, the seal contact portions  46  extend continuously smoothly with no steps between the seal contact portions  46 . The door seal member  26  closely contacts the garnish body  51 , the garnish end section  52  and the side sill  12  with no gap therebetween. Thus, it is possible to secure an enhanced sealability between the door  22  and the side sill  12 . 
     The following describe the thickness of the step garnish with reference to a sectional view of an upper portion of the side sill. 
     As shown in  FIG. 13 , the garnish end section  52  is formed integrally with the end  62  of the garnish body  51 , and the joint section  31  is covered with the garnish body  51 . 
     The thickness of the garnish end section  52  gradually decreases from the end  62  of the garnish body  51  toward the distal end, and the thickness of the garnish body  51  gradually decreases continuously from the middle portion of the garnish body  51  to the distal end of the garnish end section  52 . 
     The garnish end section  52  extending continuously from the upper wall  53  of the garnish body  51  has a thickness L 5  at its distal end. The thickness L 5  is greater than the thickness IA of the garnish end section  52  extending continuously from the side wall  54 , i.e. L 4 &lt;L 5 . Namely, if the thickness L 5  is set relatively great, it is possible to not only increase mold-filling property of soft resin forming the garnish end section  52  but also increase overall rigidity of the garnish end section  52 . 
     Further, because the garnish body  51  of hard resin is disposed over the joint section  31 , the step garnish  50  would not deform along a hollow of the joint section  31 , so that the step garnish  50  can be maintained in a predetermined shape. 
     Now, the above-described side vehicle body structure will be summarized below. 
     As shown in  FIGS. 2 to 4 ,  11  and  12 , the step garnish  50  is an integrally-molded member that comprises the garnish body  51  and the garnish end portions  52 . The garnish body  51  covers a region from the upper surface  36  of the side sill  12  to an upper portion of the side surface  38  including the seal contact portions  46  and covers the joint sections  31  as well. Each of the joint sections  31  is where at least two plate materials are lapped over and joined to each other to constitute a part of the side sill  12 . With the garnish body  51  covering such stepped joint sections  31  located on the lower edge of the door opening  42 , it is possible to enhance the outer appearance of the lower edge of the door opening  42 . Besides, because the garnish body  51  is formed of hard resin, it has rigidity great enough to allow a passenger&#39;s foot (feet) to be placed thereon. 
     The upper portion of the side surface, located outward in the vehicle width direction, is covered with the garnish body  51 . A level difference corresponding to the thickness of the garnish body  51  is formed between each of the opposite ends, in the front-rear direction of the vehicle body, of the garnish body  51 . By contrast, the garnish end section  52  formed of soft resin has considerable flexibility. Besides, the thickness of the garnish end section  52  gradually decreases from the proximal end, formed integrally with the garnish body  51 , toward the distal end. Namely, the garnish end section  52  is formed integrally with one of the ends, in the front-rear direction of the vehicle body, of the garnish body  51  and covers at least the seal contact portions  42 . In other words, the garnish end section  52  has a gently sloping shape so as to avoid formation of a level difference. Thus, no gap is formed between the upper portion of the outer side surface of the side sill  12  and the door seal member  26 , which can enhance the sealability between the door opening  42  and the door  22 . 
     In the aforementioned manner, it is possible to improve the outer appearance of the lower edge of the door opening  42  and the sealability along the door opening  42 . 
     As shown in  FIG. 11 , the thickness of the garnish body  51  decreases gradually and continuously from its middle portion toward its distal end; namely, the thickness of the garnish body  51  is smaller at the end in the front-rear direction of the vehicle body than at the middle portion. The thickness of the proximal end of the garnish end section  52  can be reduced by an amount corresponding to the reduced thickness of the end in the front-rear direction. Further, a length of the garnish end section  52  from the proximal end to the distal end can be reduced by an amount corresponding to the reduced thickness of the proximal end. Because of the reduced length of the garnish end section  52 , it is possible to fill molten resin evenly into a cavity of a mold for forming the garnish end section  52  on the garnish body  51 . Because the molten resin can be filled into the mold cavity in an appropriate manner as noted above, it is possible to achieve an enhance quality of the garnish end section  52 . 
     Further, as shown in  FIGS. 11 to 13 , the step garnish  50  formed of resin is resiliently deformable, and before the step garnish  50  is mounted on the side sill  12 , it is curved in the given direction such that the middle portion of the step garnish  50  is spaced apart from the upper surface  36  and side surface  38  of the side sill  12 . The middle portion of the step garnish  50  is lapped over the upper surface  36  and side surface  38  of the side sill  12  by being placed over and pressed against the upper surface  36  and side surface  38  against the resiliency of the step garnish  50 , so that the step garnish  50  is mounted on the side sill  12 . In the state mounted on the side sill  12 , the distal end of the garnish end portion is resiliently pressed against the upper surface  36  and side surface  38  of the side sill  12  and thus kept in close contact with the upper surface  36  and side surface  38  with no gap formed between the distal end and the upper surface  36  and side surface  38 . With no gap formed between the distal end and the upper surface  36  and side surface  38 , it is possible to even further enhance the outer appearance of the lower edge of the door opening  42  (see  FIG. 6 ) and the sealing performance along the periphery of the door opening  42 . 
     As further shown in  FIGS. 11 to 13 , of a distal end part of the garnish end section  52 , a potion contacting the upper surface  36  of the side sill  12  has a greater thickness than a portion contacting the seal contact portion  46 . Namely, the portion of the garnish end section  52  contacting the door seal portion  26  has a smaller thickness such that no gap is left between that portion and the door seal portion  26 . The portion of the garnish end section  52  contacting the upper surface  36  of the side sill  12 , on the other hand, may be formed to have a greater thickness than the portion of the garnish end section  52  contacting the seal contact portion  46 , because it is provided only for the purpose of enhancing the outer appearance of the lower edge of the door opening  46 . Because the portion of the distal end part of the garnish end section  52  has a greater thickness as noted above, it is possible to fill molten soft resin evenly into a portion, corresponding to the distal end part, of the cavity of the mold. Because the molten resin can be filled into the mold cavity in an appropriate manner as noted above, it is possible to achieve an enhanced overall quality of the garnish end section  52 . As a result, it is possible to enhance an overall rigidity of the garnish end section  52 . 
     Further, as shown in  FIG. 3 , a portion of the outer side surface  38 , in the vehicle width direction, of the side sill  12 , which is not covered with the garnish body  51 , is covered with the side sill garnish  70 . The garnish body  51  includes the lower flange  55  extending outward in the vehicle width direction from the lower end of the side wall  54  along the upper surface  71  of the side sill garnish  70 , and this lower flange  55  is placed on the upper surface  71  of the side sill garnish  70 . Because frictional resistance is produced between the lower flange  55  and the upper surface  71  of the side sill garnish  70 , the side wall  54  of the garnish body  51  can be prevented or restrained from deforming laterally outwardly in the vehicle width direction. Besides, because the lower flange  55  extends outward in the vehicle width direction from the lower end of the side wall  54  and is placed on the upper surface  71  of the side sill garnish  70 , a gap, if any, between the lower end of the side wall  54  and the upper surface  71  of the side sill garnish  70  is hardly visible, and thus, it is possible to even further enhance the outer appearance of the lower edge of the door opening  42 . 
     As further shown in  FIG. 3 , the garnish body  51  includes the upper flange  56  extending upward from the inner end, in the vehicle width direction, of the upper wall  53  covering the upper surface of the side sill  12 . The upper end of the upper flange  56  is located close to the lower end of the opening seal member  44  provided on the lower edge of the door opening  42 . As the door  22  is closed, the door opening seal  44  contacts the upper end of the upper flange  56  while elastically deforming to collapse. Because the door opening seal  44  is prevented or restrained from deforming downward by contacting the upper end of the upper flange  56 , contact pressure between the door opening seal  44  and the lower edge of the inner surface of the door  22  increases. As a consequence, sealability between the lower edge of the inner surface of the door  22  and the door opening seal  44  increases so that waterproofness and sound insulation can be significantly increased. Particularly, when the door  22  is in the closed position, it is possible to sufficiently secure double sealing by the door seal member  26  and the opening seal member  44 . 
     Note that, whereas the instant embodiment has been described above in relation to the case where the garnish body  51  and the garnish end section  52  are curved relative to the side sill  12 , the present invention is not so limited, and only the garnish end section  52  may be curved relative to the side sill  12  with the garnish body  51  formed in a straight shape. 
     INDUSTRIAL APPLICABILITY  
     The vehicle body of the present invention is well suited for application to automobiles which include a door opening formed in a side section of the vehicle body with the lower edge thereof defined by the upper surface of a side sill and a door for opening and closing the door opening. 
     REFERENCE SIGNS LIST 
       10  . . . automobile (vehicle),  11  . . . vehicle body,  12  . . . left and right, side sills,  14  . . . left and right center pillars (plate materials), . . .  17  left and right rear panels (plate materials),  21  . . . front door (door),  22  . . . rear door (door),  26  . . . door seal member,  31  . . . joint section,  33  . . . outer side sill element (plate material),  36  . . . upper surface of the side sill,  38  . . . side surface (outer surface) of the side sill,  41  . . . left and right front door openings,  42  . . . left and right rear door openings,  43  . . . front opening seal member (door opening seal),  44  . . . rear opening seal member (door opening seal),  45  . . . front seal contact portion (seal surface),  46  . . . rear seal contact portion (seal surface),  50  . . . step garnish,  51  . . . garnish body,  52  . . . garnish end section,  53  . . . upper wall,  54  . . . side wall,  55  . . . lower flange,  56  . . . upper flange,  62  . . . end of the garnish body,  70  . . . side sill garnish,  71  . . . upper surface of the side sill garnish