Patent Publication Number: US-11390146-B2

Title: Door sash structure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application of International Application No. PCT/JP2018/039537, filed Oct. 24, 2018, which designates the United States, incorporated herein by reference, and which claims the benefit of priority from Japanese Patent Application No. 2017-212127, filed Nov. 1, 2017, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     Embodiments according to the present invention relate to a door sash structure. 
     BACKGROUND ART 
     A vehicle door sash has been known that includes an upper sash, a rear sash, a lower sash and a mirror bracket. The upper sash, the rear sash and a lower sash guide a door glass for ascending and descending of the door glass. The mirror bracket is disposed between the upper sash and the lower sash. A door mirror is attached to the mirror bracket. 
     A front portion of a belt line reinforcement is attached to the bracket. The belt line reinforcement extends in a front-rear direction of a vehicle to cross the lower sash, and is attached to the bracket provided between the lower sash and a portion near the front end portion of the upper sash (refer to Patent Document 1). 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: Japanese Patent Application Laid-open No. 2015-98247 
     SUMMARY OF INVENTION 
     Problem to be Solved by the Invention 
     The conventional structure, in which the belt line reinforcement extends to cross the lower sash, causes an increase in size of the belt line reinforcement. 
     The invention is made in view of such a circumstance, and an objective of the invention is to provide a door sash structure that can prevent an increase in size of an inner reinforcement. 
     Means for Solving Problem 
     According to embodiments of the present invention, for example, a door sash structure includes: a sash that is configured to guide a front end edge of a door glass of a vehicle for ascending and descending of the door glass; an inner reinforcement that extends along a front-rear direction of the vehicle at a more inner position of the vehicle than the door glass; and an attachment member that is fixed on a side adjacent to the inside of the vehicle of the sash, and includes a mirror attachment portion and an inner reinforcement attachment portion, the mirror attachment portion being configured to allow a door mirror to be attached thereto in front of the sash in the front-rear direction, and the inner reinforcement attachment portion extending from the mirror attachment portion and allowing the inner reinforcement to be fixed thereto in the rear of the sash in the front-rear direction. As an example, it is not necessary to elongate the inner reinforcement to the front side beyond the sash, thereby making it possible to prevent an increase in size of the inner reinforcement. 
     In the door sash structure mentioned above, for example, the inner reinforcement attachment portion is configured to be fixed to a door inner panel in the rear of the sash in the front-rear direction, the door inner panel being located at a more inner position of the vehicle than the inner reinforcement. As an example, the stiffness of the door including the door sash structure and the door inner panel is increased at a portion near the door central portion, thereby preventing the door inner panel from being deformed by a sucked-out phenomenon, for example. 
     In the door sash structure mentioned above, for example, the inner reinforcement is located in the rear of the sash in the front-rear direction, and the mirror attachment portion is configured to be attached to a door inner panel in front of the sash in the front-rear direction, the door inner panel being located at a more inner position of the vehicle than the inner reinforcement. As an example, the inner reinforcement is prevented from covering a portion at which the mirror attachment portion and the door inner panel are attached, thereby making it easy to fix the mirror attachment portion and the door inner panel with a rivet or by welding. 
     In the door sash structure mentioned above, for example, the inner reinforcement attachment portion is located at a position shifted inward from the mirror attachment portion to the inside of the vehicle. 
     As an example, the inner reinforcement can be disposed at a more inner position of the vehicle than the sash guiding the door glass, thereby preventing interference between the inner reinforcement and the door glass. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of a vehicle according to an embodiment; 
         FIG. 2  is a perspective view of a front door in the embodiment; 
         FIG. 3  is a side view of a door sash in the embodiment; 
         FIG. 4  is a side view of a part of the door sash in the embodiment; 
         FIG. 5  is a cross-sectional view of a lower sash in the embodiment which is taken along the line F 5 -F 5  in  FIG. 3 ; 
         FIG. 6  is a cross-sectional view of the lower sash and a mirror bracket in the embodiment which is taken along the line F 6 -F 6  in  FIG. 4 ; 
         FIG. 7  is a cross-sectional view of a part of the door sash in the embodiment which is taken along the line F 7 -F 7  in  FIG. 4 ; and 
         FIG. 8  is a cross-sectional view of a part of the front door in the embodiment which is taken along the line F 8 -F 8  in  FIG. 4 . 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     The following describes an embodiment with reference to  FIGS. 1 to 8 . In the present specification, constituent elements according to the embodiment and descriptions thereof are described with multiple expressions in some cases. The constituent elements and descriptions thereof described with multiple expressions may be described with other expressions other than those described herein. Constituent elements and descriptions thereof that are not described with multiple expressions may also be described with other expressions other than those described herein. 
       FIG. 1  is a side view of a vehicle  1  according to the embodiment. As illustrated in  FIG. 1 , the vehicle  1  is a four-wheel automobile. The vehicle  1  is not limited to this example. The vehicle  1  has front doors  2 , rear doors  3 , and door mirrors  4 . The vehicle  1  may not have the rear doors  3 . 
     As illustrated in each drawing, an X-axis, a Y-axis, and a Z-axis are defined in the specification. The X-axis, the Y-axis, and the Z-axis are orthogonal to one another. The X-axis is along the width of the vehicle  1 . The Y-axis is along the length of the vehicle  1 . The Z-axis is along the height of the vehicle  1 . Hereinafter, the direction along the Y axis is described as a front-rear direction of the vehicle  1 . The direction along the Z axis is described as an upper-lower direction of the vehicle  1 . 
     The front doors  2  are provided in front of the rear doors  3  in the front-rear direction of the vehicle  1 . In  FIG. 1 , the direction indicated with the arrow of the Y axis is described as a front direction. The direction opposite the arrow of the Y axis is described as a rear direction. The door mirrors  4  are attached to the respective front doors  2 . 
       FIG. 2  is a perspective view of the front door  2  in the embodiment. As illustrated in  FIG. 2 , the front door  2  has a door sash  11  and a door panel  12 . The front door  2  also has a door glass  13  illustrated in  FIG. 1 . The door sash  11  may also be described as a door sash structure. 
     The door panel  12  is attached to the door sash  11 . The door panel  12  has an outer panel  15  illustrated in  FIG. 1  and an inner panel  16  illustrated in  FIG. 2 . The outer panel  15  is attached to the door sash  11  from the outside (an outdoor side) of the vehicle  1 . The outer panel  15  may also be described as a door outer panel. The inner panel  16  is attached to the door sash  11  from an inside (an indoor side) of the vehicle  1 . The inner panel  16  may also be described as a door inner panel. 
       FIG. 3  is a side view of the door sash  11  in the embodiment. As illustrated in  FIG. 3 , the door sash  11  has an upper frame  21 , a lower sash  22 , a mirror bracket  23 , a reinforcement bracket  24 , and an inner belt line reinforcement (hereinafter described as an inner reinforcement)  25 . 
     The upper frame  21  may also be described as a frame member. The lower sash  22  may also be described as a sash, a sash member, or a channel. The mirror bracket  23  may also be described as a door mirror attachment member, a door constituting member, another member, a mirror attachment member, or an attachment member. The reinforcement bracket  24  may also be described as an outer reinforcement attachment member. 
     The upper frame  21  has a rear sash  31  and an upper sash  32 . The rear sash  31  and the upper sash  32  are each made of aluminum and manufactured by roll forming, for example. The material and the manufacturing method of the rear sash  31  and the upper sash  32  are not limited to this example. 
     The rear sash  31  extends in a substantially upper-lower direction and forms a rear edge portion of the door sash  11 . The upper sash  32  extends in a substantially front-rear direction and forms an upper edge portion and a front edge portion of the door sash  11 . The rear end portion of the upper sash  32  is connected to the upper end portion of the rear sash  31 . 
       FIG. 4  is a side view of a part of the door sash  11  in the embodiment. The lower sash  22  illustrated in  FIG. 4  is made of aluminum and manufactured by roll forming, for example. The material and the manufacturing method of the lower sash  22  is not limited to this example. For example, the lower sash  22  may be manufactured by extrusion molding or pultrusion molding. 
     The lower sash  22  extends in a substantially upper-lower direction. The upper end portion of the lower sash  22  is connected to the front end portion of the upper sash  32 . In other words, the lower sash  22  is fixed to the upper frame  21 . 
     A window hole  35  surrounded by the upper frame  21 , the lower sash  22 , and the outer panel  15  illustrated in  FIG. 1  is provided to the front door  2 . The door glass  13  illustrated in  FIG. 1  is disposed between the lower sash  22  and the rear sash  31  of the upper frame  21 . The lower sash  22  and the rear sash  31  of the upper frame  21  guide the door glass  13  for ascending and descending of the door glass  13  in the window hole  35 . 
       FIG. 5  is a cross-sectional view of the lower sash  22  in the embodiment which is taken along the line F 5 -F 5  in  FIG. 3 . As illustrated in  FIG. 5 , the lower sash  22  has a substantially C-shaped cross section and has a first sidewall  41 , a second sidewall  42 , and an end wall  43 . 
     The first sidewall  41  extends along an outer surface  13   a  of the door glass  13 , the outer surface  13   a  facing the outside of the vehicle  1 , in a cross section perpendicular to a longitudinal direction of the lower sash  22 . The outer surface  13   a  of the door glass  13  faces the first sidewall  41 . The first sidewall  41  has a first end portion  41   a , a second end portion  41   b , a first inner surface  41   c , a first outer surface  41   d , and a first locking portion  41   e.    
     The first end portion  41   a  is the front end portion of the first sidewall  41  in the cross section illustrated in  FIG. 5 . The second end portion  41   b  is located on the side opposite to the first end portion  41   a . The second end portion  41   b  is the rear end portion of the first sidewall  41  in the cross section illustrated in  FIG. 5 . 
     The first inner surface  41   c  faces the outer surface  13   a  of the door glass  13 . The first inner surface  41   c  faces the second sidewall  42  through the door glass  13 . The first outer surface  41   d  is located on the side opposite to the first inner surface  41   c . The first outer surface  41   d  faces the outside of the vehicle  1 . 
     The first locking portion  41   e  is located between the first end portion  41   a  and the second end portion  41   b . The first locking portion  41   e  protrudes from the first inner surface  41   c . The first locking portion  41   e  extends in a direction along which the lower sash  22  extends (the longitudinal direction of the lower sash  22 ) and is provided substantially all over the first sidewall  41  in the longitudinal direction of the lower sash  22 . The first locking portion  41   e  is not limited to this example. 
     The second sidewall  42  extends along an inner surface  13   b  of the door glass  13 , the inner surface  13   b  facing the inside of the vehicle  1 , in the cross section perpendicular to the longitudinal direction of the lower sash  22 . The inner surface  13   b  of the door glass  13  faces the second sidewall  42 . The second sidewall  42  has a third end portion  42   a , a fourth end portion  42   b , a second inner surface  42   c , a second outer surface  42   d , and a second locking portion  42   e.    
     The third end portion  42   a  is the front end portion of the second sidewall  42  in the cross section illustrated in  FIG. 5 . The fourth end portion  42   b  is located on the side opposite to the third end portion  42   a . The fourth end portion  42   b  is the rear end portion of the second sidewall  42  in the cross section illustrated in  FIG. 5 . 
     The second inner surface  42   c  faces the inner surface  13   b  of the door glass  13 . The second inner surface  42   c  faces the first sidewall  41  through the door glass  13 . The second outer surface  42   d  is located on the side opposite to the second inner surface  42   c . The second outer surface  42   d  faces the inside of the vehicle  1 . 
     The second locking portion  42   e  is located between the third end portion  42   a  and the fourth end portion  42   b . The second locking portion  42   e  protrudes from the second inner surface  42   c . The second locking portion  42   e  extends in the direction in which the lower sash  22  extends and is provided substantially all over the second sidewall  42  in the longitudinal direction of the lower sash  22 . The second locking portion  42   e  is not limited to this example. 
     The end wall  43  extends along a front end edge  13   c  of the door glass  13 , the front end edge  13   c  substantially facing the front side. In other words, the front end edge  13   c  of the door glass  13  faces the end wall  43 . The front end edge  13   c  may also be described as an end surface. The front end edge  13   c  is the edge of the door glass  13  that substantially faces the front side in the front-rear direction of the vehicle  1 . The front end edge  13   c  is connected to the front end of the outer surface  13   a  and the front end of the inner surface  13   b . The lower sash  22  guides the front end edge  13   c  of the door glass  13  for ascending and descending of the door glass  13 . In the cross section illustrated in  FIG. 5 , the end wall  43  extends in the width direction of the vehicle  1 . 
     The end wall  43  is connected to the first end portion  41   a  of the first sidewall  41  and the third end portion  42   a  of the second sidewall  42 . In other words, the first sidewall  41  and the second sidewall  42  extend from the end wall  43 . 
     The distance between the third end portion  42   a  and the fourth end portion  42   b  is longer than the distance between the first end portion  41   a  and the second end portion  41   b . In other words, the second sidewall  42  extends from the end wall  43  in such a manner that the length of the second sidewall  42  is longer than that of the first sidewall  41 . 
     The second sidewall  42  extends in such a direction that the distance between the first sidewall  41  and the second sidewall  42  increases as the second sidewall  42  extends farther away from the end wall  43 . In the embodiment, the first sidewall  41  extends in the direction orthogonal to the end wall  43  while the second sidewall  42  extends in the direction substantially obliquely intersecting the end wall  43 . The second sidewall  42  may be bent at least one part thereof so long as the second sidewall  42  extends in the direction obliquely intersecting the end wall  43  as a whole. The extending directions of the first sidewall  41  and the second sidewall  42  are not limited to this example. 
     The vehicle  1  also has a glass run  45 , which is illustrated with the two dot chain line in  FIG. 5 . The glass run  45  is made of an elastic material such as elastomer. The glass run  45  is attached to the lower sash  22  and interposed between the lower sash  22  and the door glass  13 . The glass run  45  has a first frame wall  45   a , a second frame wall  45   b , a third frame wall  45   c , a plurality of lips  45   d , and a plurality of protrusions  45   e.    
     The first frame wall  45   a  extends along the first inner surface  41   c  of the first sidewall  41 . The second frame wall  45   b  extends along the second inner surface  42   c  of the second sidewall  42 . The third frame wall  45   c  extends along the end wall  43  and is connected to the first frame wall  45   a  and the second frame wall  45   b.    
     The lips  45   d  are provided to the end portion of the first frame wall  45   a  and the end portion of the second frame wall  45   b . The lips  45   d  may be further provided to other places of the first frame wall  45   a  and the second frame wall  45   b.    
     The door glass  13  is disposed between the first frame wall  45   a  and the second frame wall  45   b . The lips  45   d  each extend toward the door glass  13  and are each in contact with the door glass  13 . As a result, the lips  45   d  are elastically deformed and elastically hold the door glass  13 . The glass run  45  guides the door glass  13  together with the lower sash  22  for ascending and descending of the door glass  13 . 
     One of the protrusions  45   e  protrudes from the first frame wall  45   a  or the third frame wall  45   c  toward the first sidewall  41  and is caught by the first locking portion  41   e . The other of the protrusions  45   e  protrudes from the second frame wall  45   b  or the third frame wall  45   c  toward the second sidewall  42  and is caught by the second locking portion  42   e . As a result, the glass run  45  is locked and held by the first locking portion  41   e  and the second locking portion  42   e.    
     As illustrated in  FIG. 3 , the mirror bracket  23  has a mirror attachment portion  51  formed in a substantially triangle shape and an inner reinforcement attachment portion  52  extending from the mirror attachment portion  51 . The mirror attachment portion  51  and the inner reinforcement attachment portion  52  are integrally formed. 
       FIG. 6  is a cross-sectional view of the lower sash  22  and the mirror bracket  23  in the embodiment which is taken along the line F 6 -F 6  in  FIG. 4 . The mirror attachment portion  51  has a sash support portion  55  illustrated in  FIG. 6 , and a pillar portion  56 , a door mirror attachment portion  57 , a lower portion  58 , and a fixing piece  59  that are illustrated in  FIG. 4 . The pillar portion  56  may also be described as a second extending portion. 
     As illustrated in  FIG. 6 , the sash support portion  55  extends along the second sidewall  42  of the lower sash  22  and is in contact with the second outer surface  42   d . The second sidewall  42  has a plurality of fixing portions  42   f . At the fixing portions  42   f , the second sidewall  42  is fixed to the sash support portion  55  with rivets  61 , for example. The rivets  61  are self-pierce rivets (SPR), for example. The fixing portions  42   f  may be fixed to the sash support portion  55  by other means such as spot welding. 
     The fixing portions  42   f  are located between the fourth end portion  42   b  and the second locking portion  42   e . As illustrated in  FIG. 4 , a plurality of fixing portions  42   f  are arranged in the extending direction of the lower sash  22  at intervals. 
     As illustrated in  FIG. 6 , the sash support portion  55  is fixed to the fixing portions  42   f  while the sash support portion  55  is in contact with the second outer surface  42   d  of the second sidewall  42 . The sash support portion  55  is fixed to the second sidewall  42  from the inside of the vehicle  1 . In other words, the sash support portion  55  is fixed to the lower sash  22  on the side of the lower sash  22  that faces the inside of the vehicle  1 . This fixing direction is not the direction in which the rivets  61  are driven but the direction in which the sash support portion  55  is in contact with the second sidewall  42 . 
     The first sidewall  41  is provided with a plurality of notches  41   f . The notches  41   f  may also be described as openings. Each of the notches  41   f  is a notch depressed from the second end portion  41   b  to have a substantially circular arc shape. The notches  41   f  may have another shape. The first sidewall  41  may be provided with holes serving as openings. The notches  41   f  serving as openings expose the fixing portions  42   f  in a direction normal to the second inner surface  42   c  of the second sidewall  42 . 
     The notches  41   f  are arranged apart from the first locking portion  41   e . In other words, the notches  41   f  are disposed closer to the second end portion  41   b  than the first locking portion  41   e  is. The end portions of the notches  41   f  may be in contact with the first locking portion  41   e . The notches  41   f  may be formed over the first locking portion  41   e.    
     For example, a gun G is inserted through the notch  41   f  and drives the rivet  61  into the fixing portion  42   f  and the sash support portion  55 . The gun G may be inserted through the notch  41   f  and spot-weld the fixing portion  42   f  and the sash support portion  55 . 
     As illustrated in  FIG. 4 , the pillar portion  56  is connected to the front end portion of the upper sash  32  together with the lower sash  22 . The pillar portion  56  extends from the upper sash  32  of the upper frame  21 . The pillar portion  56  forms the front edge portion of the door sash  11  together with the upper sash  32 . A hinge  63  is attached to the front end portion of the pillar portion  56 . The hinge  63  is fixed to the vehicle body of the vehicle  1 . 
     The door mirror attachment portion  57  is provided between the sash support portion  55  and the pillar portion  56 . The door mirror attachment portion  57  is, thus, located on the opposite side of the lower sash  22  from the door glass  13 . In other words, the door mirror attachment portion  57  is located on the front side of the lower sash  22  in the front-rear direction of the vehicle  1 . The door mirror attachment portion  57  is formed to be a substantially flat plate of a triangle shape. The door mirror  4  illustrated in  FIG. 1  is attached to the door mirror attachment portion  57 . 
     The lower portion  58  extends substantially downward from the door mirror attachment portion  57  and is provided between the sash support portion  55  and the pillar portion  56 . The lower portion  58  is, thus, located on the opposite side of the lower sash  22  from the door glass  13 . 
     The lower portion  58  is provided with a plurality of fixing portions  58   a . The fixing portions  58   a  are attached to the inner panel  16  illustrated in  FIG. 2  with rivets  64 , for example. The fixing portions  58   a  may be attached to the inner panel  16  by other means such as spot welding. 
     The fixing piece  59  extends in a substantially front direction from the pillar portion  56 . In the upper-lower direction of the vehicle  1 , the fixing piece  59  is disposed at substantially the same position as the lower end portion of the door mirror attachment portion  57 . The position of the fixing piece  59  is not limited to this example. 
     The inner reinforcement attachment portion  52  extends in the rear direction from the sash support portion  55  of the mirror attachment portion  51 . The inner reinforcement attachment portion  52  is not limited to this example. The inner reinforcement attachment portion  52  is located on the same side of the lower sash  22  as the door glass  13 . 
       FIG. 7  is a cross-sectional view of a part of the door sash  11  in the embodiment which is taken along the line F 7 -F 7  in  FIG. 4 . As illustrated in  FIG. 7 , the inner reinforcement attachment portion  52  is located at (shifted to) a more inner position of the vehicle  1  than the mirror attachment portion  51 . 
     The inner reinforcement attachment portion  52  has a reinforcement attachment wall  65  and two panel attachment walls  66 . The reinforcement attachment wall  65  may also be described as a first portion. The panel attachment wall  66  may also be described as a second portion. 
     The reinforcement attachment wall  65  is disposed at a position slightly shifted to the inside of the vehicle  1  from the sash support portion  55  in the width direction of the vehicle  1 . The reinforcement attachment wall  65  has an outer surface  65   a  and an inner surface  65   b . The outer surface  65   a  faces the outside of the vehicle  1 . The inner surface  65   b  is located on the side opposite to the outer surface  65   a  and faces the inside of the vehicle  1 . The outer surface  65   a  and the inner surface  65   b  are each formed to be substantially flat. 
     The two panel attachment walls  66  are located at the positions shifted toward the inside of the vehicle  1  from the end portions of the reinforcement attachment wall  65  that are positioned in the upper-lower direction of the vehicle  1 , respectively. In other words, the panel attachment walls  66  protrude from the reinforcement attachment wall  65  to the inside of the vehicle  1 . The panel attachment walls  66  are arranged at a more inner position of the vehicle  1  than the reinforcement attachment wall  65  in the width direction of the vehicle  1 . 
     Each of the panel attachment walls  66  has an outer surface  66   a  and an inner surface  66   b . The outer surfaces  66   a  face the outside of the vehicle  1 . The inner surfaces  66   b  are located on the side opposite to the outer surfaces  66   a  and face the inside of the vehicle  1 . The outer surfaces  66   a  and the inner surfaces  66   b  are each formed to be substantially flat. 
     As illustrated in  FIG. 4 , the reinforcement bracket  24  is a component which is separated from the lower sash  22 , and is not fixed to the lower sash  22  but is fixed to an outer surface  23   a  of the mirror bracket  23 . The outer surface  23   a  of the mirror bracket  23  faces the outside of the vehicle  1 . While the reinforcement bracket  24  is connected to the lower sash  22  via the mirror bracket  23 , the reinforcement bracket  24  is a component which is separated from the lower sash  22 . In other words, the reinforcement bracket  24  is not integrated with the lower sash  22 , and is only connected to the lower sash  22  indirectly but is not connected to the lower sash  22  directly. 
     For example, when the lower sash  22  is elastically deformed, the reinforcement bracket  24  does not directly follow the elastic deformation of the lower sash  22 , and the lower sash  22  and the reinforcement bracket  24  move relatively to each other and slightly. When the mirror bracket  23  is elastically deformed, the reinforcement bracket  24  directly follows the elastic deformation of the mirror bracket  23 , and the lower sash  22  and the reinforcement bracket  24  move relatively to each other and slightly. 
     The reinforcement bracket  24  is located at a more outer position of the vehicle  1  than the mirror bracket  23 . The reinforcement bracket  24  has an extending portion  71 , a first fixing portion  72 , and a second fixing portion  73 . The extending portion  71  may also be described as a first extending portion or an attachment portion. 
     The extending portion  71  is located below the door mirror attachment portion  57  and disposed on the upper end portion side of the lower portion  58 . The extending portion  71  extends in the front-rear direction of the vehicle  1 . The extending direction of the extending portion  71  intersects the extending direction of the lower sash  22 . The door mirror attachment portion  57  is surrounded by the lower sash  22 , the pillar portion  56  of the mirror bracket  23 , and the extending portion  71  of the reinforcement bracket  24 , and depressed to the inside of the vehicle  1  from the lower sash  22 , the pillar portion  56 , and the extending portion  71 . 
     The extending portion  71  has an attachment wall  75 , a first peripheral wall  76 , a second peripheral wall  77 , and a third peripheral wall  78 . The first peripheral wall  76 , the second peripheral wall  77 , and the third peripheral wall  78  extend from the attachment wall  75  and are connected to one another. 
       FIG. 8  is a cross-sectional view of a part of the front door  2  in the embodiment which is taken along the line F 8 -F 8  in  FIG. 4 . As illustrated in  FIG. 8 , the attachment wall  75  is apart from the mirror bracket  23  toward the outside of the vehicle  1 , and extends in the front-rear direction of the vehicle  1 . The attachment wall  75  covers two holes  23   b  provided to the mirror bracket  23 . 
     The attachment wall  75  has an outer surface  75   a  and an inner surface  75   b . The outer surface  75   a  faces the outside of the vehicle  1 . The inner surface  75   b  is located on the side opposite to the outer surface  75   a  and faces the inside of the vehicle  1 . The inner surface  75   b  faces the mirror bracket  23  with a distance therebetween. 
     The first peripheral wall  76  extends toward the mirror bracket  23  from the lower end portion of the attachment wall  75 . The second peripheral wall  77  extends toward the mirror bracket  23  from the upper end portion of the attachment wall  75 . 
     As illustrated in  FIG. 4 , the third peripheral wall  78  extends toward the mirror bracket  23  from the rear end portion of the attachment wall  75 . The third peripheral wall  78  has a side surface  78   a . The side surface  78   a  is closer to the lower sash  22  than any portion of the mirror bracket  23 . 
     The side surface  78   a  faces in a substantially rear direction and faces the lower sash  22 . The side surface  78   a  is, however, apart from the lower sash  22 . In this way, the reinforcement bracket  24  is apart from the lower sash  22 . 
     The first fixing portion  72  extends substantially downward from a substantially central portion of the first peripheral wall  76  in the front-rear direction of the vehicle  1 . The first fixing portion  72  is fixed to the lower portion  58  of the mirror bracket  23  with a rivet  79 , for example. The first fixing portion  72  may be fixed to the lower portion  58  by other means such as spot welding. 
     The second fixing portion  73  extends substantially upward from the front and upper end portion of the attachment wall  75 . The second fixing portion  73  is fixed to the fixing piece  59  of the mirror bracket  23  with the rivet  79 , for example. The second fixing portion  73  may be fixed to the lower portion  58  by other means such as spot welding. 
     The first fixing portion  72  and the second fixing portion  73  are arranged at different positions in the upper-lower direction of the vehicle  1 . The first fixing portion  72  and the second fixing portion  73  are arranged at different positions in the front-rear direction of the vehicle  1 . 
     As illustrated in  FIG. 4 , a virtual line L connecting the first fixing portion  72  and the second fixing portion  73  intersects the attachment wall  75  when the reinforcement bracket  24  is viewed in the direction normal to the outer surface  75   a  of the attachment wall  75 . The virtual line L connects the position (rivet  79 ) at which the first fixing portion  72  is fixed to the mirror bracket  23  and the position (rivet  79 ) at which the second fixing portion  73  is fixed to the mirror bracket  23 . 
     As illustrated in  FIG. 3 , the inner reinforcement  25  extends in the front-rear direction of the vehicle  1 . The inner reinforcement  25  extends along the inner surface  13   b  of the door glass  13  at a more inner position of the vehicle  1  than the door glass  13 . 
     The inner reinforcement  25  is located on the door glass  13  side of the lower sash  22 . In other words, the inner reinforcement  25  is located on the rear direction side of the lower sash  22  in the front-rear direction of the vehicle  1 . The inner reinforcement  25 , thus, does not cover the mirror attachment portion  51  of the mirror bracket  23  from the inside of the vehicle  1 . The inner reinforcement  25  is not limited to this example. 
     The front end portion of the inner reinforcement  25  is fixed to the inner reinforcement attachment portion  52  of the mirror bracket  23 . The rear end portion of the inner reinforcement  25  is fixed to the rear sash  31 . 
     As illustrated in  FIG. 4 , the inner reinforcement  25  has a bracket attachment wall  81  and two panel attachment walls  82 . The bracket attachment wall  81  extends in the front-rear direction of the vehicle  1  and is disposed at a position closer to the door glass  13  than the panel attachment walls  82 . 
     The bracket attachment wall  81  has a protruding piece  81   a . The protruding piece  81   a  may also be described as a fixing portion. The protruding piece  81   a  protrudes from the front end of the bracket attachment wall  81  in the front direction. The protruding piece  81   a  is formed to be a plate of a substantially triangle shape, for example. The protruding piece  81   a  may be formed in another shape. 
     As illustrated in  FIG. 7 , the protruding piece  81   a  is in contact with the outer surface  65   a  of the reinforcement attachment wall  65  of the inner reinforcement attachment portion  52 . In other words, the protruding piece  81   a  is in contact with the reinforcement attachment wall  65  from the outside of the vehicle  1 . The bracket attachment wall  81  including the protruding piece  81   a  is, thus, disposed at substantially the same position as the sash support portion  55  in the width direction of the vehicle  1 . The inner reinforcement  25  is located at a more inner position of the vehicle  1  than the door glass  13  and the glass run  45 . 
     The protruding piece  81   a  is fixed to the outer surface  65   a  of the reinforcement attachment wall  65  by metal inert gas (MIG) welding, for example. The protruding piece  81   a  may be fixed to the reinforcement attachment wall  65  with other means such as a rivet. 
     As described above, the inner reinforcement  25  is fixed to the inner reinforcement attachment portion  52  of the mirror bracket  23  from the outside of the vehicle  1 . The inner reinforcement  25  is fixed to the rear sash  31  illustrated in  FIG. 3  from the outside of the vehicle  1  by MIG welding, for example. In this way, the inner reinforcement  25  is fixed to the mirror bracket  23  and the rear sash  31  from the same direction in the width direction of the vehicle  1 . 
     As illustrated in  FIG. 4 , the two panel attachment walls  82  are respectively disposed at the positions shifted toward the inside of the vehicle  1  from the corresponding end portions of the bracket attachment wall  81  in the upper-lower direction of the vehicle  1 . In other words, the panel attachment walls  82  protrude to the inside of the vehicle  1  from the bracket attachment wall  81 . The panel attachment walls  82  are disposed at more inner positions of the vehicle  1  than the bracket attachment wall  81  in the width direction of the vehicle  1 . 
     The inner panel  16  illustrated in  FIG. 2  is located at a more inner position of the vehicle  1  than the inner reinforcement  25 . The inner panel  16  is in contact with the panel attachment walls  66  of the inner reinforcement attachment portion  52  of the mirror bracket  23  and the panel attachment walls  82  of the inner reinforcement  25  from the inside of the vehicle  1 . 
     As illustrated in  FIG. 7 , the panel attachment walls  66  of the inner reinforcement attachment portion  52  of the mirror bracket  23  are attached to the inner panel  16  with rivets  85 , for example. As illustrated in  FIG. 4 , the panel attachment walls  82  of the inner reinforcement  25  are attached to the inner panel  16  with rivets  86 , for example. The panel attachment walls  66  and  82  may be attached to the inner panel  16  by other means such as spot welding. 
     As described above, the inner panel  16  is fixed to the panel attachment walls  66  of the mirror bracket  23  and the panel attachment walls  82  of the inner reinforcement  25  on the door glass  13  side of the lower sash  22 . The inner panel  16  is fixed to the lower portion  58  of the mirror bracket  23  on the side opposite to the door glass  13  side of the lower sash  22 . Since the inner panel  16  is fixed to the multiple components at multiple positions, the stiffness of the front door  2  increases. 
     As illustrated in  FIG. 8 , the front door  2  further has an outer waistline reinforcement (hereinafter described as an outer reinforcement)  90 . The outer reinforcement  90  extends in the front-rear direction of the vehicle  1 . The outer reinforcement  90  extends along the outer surface  13   a  of the door glass  13  at a more outer position of the vehicle  1  than the door glass  13 . 
     The front end portion of the outer reinforcement  90  is attached to the reinforcement bracket  24 . The rear end portion of the outer reinforcement  90  is attached to the rear sash  31 . 
     The outer reinforcement  90  is in contact with the outer surface  75   a  of the attachment wall  75  of the reinforcement bracket  24 . The attachment wall  75  extends along the outer reinforcement  90 . The outer reinforcement  90  is attached to the attachment wall  75  of the reinforcement bracket  24  with rivets  91 , for example. 
     The hole  23   b  of the mirror bracket  23  exposes the rivet  91  provided to the attachment wall  75  to the inside of the vehicle  1 . For example, the gun G is inserted through the hole  23   b  and drives the rivet  91  into the attachment wall  75  and the outer reinforcement  90 . The gun G may be inserted through the hole  23   b  and spot weld the attachment wall  75  and the outer reinforcement  90 . 
     The outer panel  15  is attached to the outer reinforcement  90  by hemming bending, for example. The outer panel  15  is, thus, attached to the reinforcement bracket  24  with the outer reinforcement  90  interposed therebetween. The outer panel  15  may be directly attached to the reinforcement bracket  24 . 
     In a certain situation, during running of the vehicle  1  at a high speed, what is called a sucked-out phenomenon, in which the front door  2  is sucked out to the outside of the vehicle  1  due to a negative pressure, occurs. The front door  2  is fixed to the vehicle body at the front end portion and rear end portion thereof with the hinge  63  illustrated in  FIG. 3  and other members. A larger load acts on the substantially central portion of the front door  2  in the front-rear direction of the vehicle  1  and the substantially upper end portions of the door sash  11  and the door glass  13 . 
     The sucked-out phenomenon causes the outer panel  15  connected to the door sash  11  to be sucked out to the outside of the vehicle  1 . The load due to the sucked-out phenomenon acts on the mirror bracket  23  via the outer panel  15 , the outer reinforcement  90 , and the reinforcement bracket  24 . 
     As a result of action of the load on the mirror bracket  23 , the sash support portion  55  of the mirror bracket  23  pushes the lower sash  22  toward the outside of the vehicle  1 . However, since the mirror bracket  23  is fixed to the vehicle body by the hinge  63 , the load acting on the lower sash  22  from the mirror bracket  23  is reduced. 
     The reinforcement bracket  24  is apart from the lower sash  22 . This structure prevents the reinforcement bracket  24  from directly applying a load to the lower sash  22 . 
     The outer reinforcement  90 , the reinforcement bracket  24 , and the mirror bracket  23  each have ridges and valleys that are formed by bending and form what is called a channel structure. With this structure, the load applied to the lower sash  22  is reduced when the load acts via the outer panel  15 , the outer reinforcement  90 , the reinforcement bracket  24 , and the mirror bracket  23  on the lower sash  22 . 
     As described above, even when the sucked-out phenomenon occurs, the load due to the sucked-out phenomenon acting on the lower sash  22  is reduced. As a result, the lower sash  22  is prevented from being deformed. 
     In the door sash  11  according to the embodiment, the reinforcement bracket  24  is separated from the lower sash  22  while the reinforcement bracket  24  is fixed to the mirror bracket  23 . The reinforcement bracket  24  is not fixed to the lower sash  22 . When the sucked-out phenomenon occurs, the outer reinforcement  90 , the reinforcement bracket  24  to which the outer reinforcement  90  is attached, and the mirror bracket  23  to which the reinforcement bracket  24  is fixed are sucked out to the outside of the vehicle  1 . Since the lower sash  22  and the reinforcement bracket  24  are separated, they can relatively move. As a result, the load due to the sucked-out phenomenon is applied to the lower sash  22  via the outer panel  15 , the outer reinforcement  90 , the reinforcement bracket  24 , and the mirror bracket  23 . When the load is applied from the outer panel  15  to the lower sash  22 , the load is reduced by the outer panel  15 , the outer reinforcement  90 , the reinforcement bracket  24 , and the mirror bracket  23 . As a result, the load acting on the lower sash  22  is reduced. 
     The reinforcement bracket  24  is apart from the lower sash  22 . When the reinforcement bracket  24  moves toward the lower sash  22 , the reinforcement bracket  24  is prevented from contacting the lower sash  22  and from directly applying the load to the lower sash  22 . As a result, the load acting on the lower sash  22  is reduced. 
     The mirror bracket  23  is fixed to the second sidewall  42  of the lower sash  22 , the second sidewall  42  extending along the inner surface  13   b  of the door glass  13 . When the sucked-out phenomenon occurs, the mirror bracket  23  sucked out to the outside of the vehicle  1  pushes the lower sash  22  toward the outside of the vehicle  1 . The end wall  43  of the lower sash  22  extends along the front end edge  13   c  of the door glass  13 . Since the end wall  43  extends in substantially the same direction as the mirror bracket  23  pushes the lower sash  22  in the cross section of the lower sash  22 , the end wall  43  has a high stiffness in the direction. As a result, the lower sash  22  is prevented from being deformed as if its substantially C-shaped cross section collapses when the mirror bracket  23  is sucked out to the outside of the vehicle  1 . 
     The reinforcement bracket  24  has the extending portion  71 , and the first fixing portion  72  and the second fixing portion  73  that extend from the extending portion  71  and are fixed to the mirror bracket  23 . When the reinforcement bracket  24  is viewed in the direction normal to the outer surface  75   a  of the extending portion  71 , the virtual line L connecting the first fixing portion  72  and the second fixing portion  73  intersects the extending portion  71 . When the outer panel  15  and the outer reinforcement  90  are sucked out to the outside of the vehicle  1 , this structure prevents the reinforcement bracket  24  from being bent with the first fixing portion  72  or the second fixing portion  73  as a fulcrum. 
     The extending portion  71  extends in the direction intersecting the extending direction of the lower sash  22 . The pillar portion  56  extends from the upper frame  21 . The door mirror attachment portion  57  is, thus, surrounded by the extending portion  71 , the pillar portion  56 , and the lower sash  22 , each of which extends in the certain direction. This structure makes it easier to seal respective gaps between the door mirror  4 , and the extending portion  71 , the pillar portion  56 , and the lower sash  22  than a case where the members surrounding the door mirror attachment portion  57  have complicated shapes. As a result, sealing property of the door mirror attachment portion  57  is improved. 
     The fixing portion  42   f  of the second sidewall  42  is located farther away from the first sidewall  41  as the fixing portion  42   f  is located farther away from the end wall  43 . With this structure, since the gun G can be easily set on the second sidewall  42  even when the length of the second sidewall  42  protruding from the end wall  43  is short, the second sidewall  42  can be easily fixed to the member that constitutes at least a part of the front door  2  (door constituting member) such as the mirror bracket  23 , and an increase in size of the lower sash  22  is prevented. In the embodiment, the fixing portions  42   f  are fixed to the mirror bracket  23 . The fixing portions  42   f  may be fixed to another door constituting member such as a door frame (cover) covering the lower sash  22 . The rear sash  31  or the upper sash  32  of the upper frame  21  may have the first sidewall  41 , the second sidewall  42 , and the end wall  43 . The channel may be the rear sash  31  or the upper sash  32 . The door constituting member may be another member such as the door frame. 
     The first sidewall  41  is provided with the notches  41   f  each of which exposes the fixing portion  42   f  in the direction normal to the second inner surface  42   c  of the second sidewall  42 . This structure makes it easy for the gun G to be inserted through the notch  41   f  and to be set on the second inner surface  42   c . This makes it easier to fix the second sidewall  42  to the mirror bracket  23 . 
     The notches  41   f  are provided closer to the second end portion  41   b  than the first locking portion  41   e  is. This structure prevents the first locking portion  41   e  from being chipped by the notches  41   f , thereby making it possible for the first locking portion  41   e  to more reliably hold the glass run  45 . 
     The distance between the third end portion  42   a  and the fourth end portion  42   b  of the second sidewall  42  is longer than the distance between the first end portion  41   a  and the second end portion  41   b  of the first sidewall  41 . In the second sidewall  42  formed in this way, the fixing portions  42   f  configured to be fixed to the mirror bracket  23  are provided between the fourth end portion  42   b  and the second locking portion  42   e . The lower sash  22  is fixed to the mirror bracket  23  on the tip side of the second sidewall  42  having the length longer than that of the first sidewall  41 . This structure prevents the fixing portions  42   f  from being hidden by the first sidewall  41 , thereby making it possible to fix the second sidewall  42  easier to the mirror bracket  23 . 
     The mirror bracket  23  has the mirror attachment portion  51  and the inner reinforcement attachment portion  52 . The mirror attachment portion  51  is configured to be fixed to the lower sash  22  and to allow the door mirror  4  to be attached thereto on the front side of the lower sash  22  in the front-rear direction. The inner reinforcement attachment portion  52  extends from the mirror attachment portion  51  and to which the inner reinforcement  25  is fixed on the rear side of the lower sash  22  in the front-rear direction. With this structure, it is not necessary to elongate the inner reinforcement  25  toward the front side beyond the lower sash  22 , thereby making it possible to prevent an increase in size of the inner reinforcement  25 . As a result, the door sash  11  can be reduced in weight. 
     The inner reinforcement attachment portion  52  is configured to be attached to the inner panel  16  on the rear side of the lower sash  22  in the front-rear direction. For example, a load which is generated by suction due to the sucked-out phenomenon, side collision, and door opening and closing and acts on the inner panel  16  becomes larger at the door central portion that is apart from the door front end and the door rear end where the front door  2  is fixed to the vehicle body. The position at which the inner reinforcement attachment portion  52  is attached to the inner panel  16  is located on the rear side of the lower sash  22 , and thus close to the door central portion. With this structure, the stiffness of the front door  2  including the door sash  11  and the inner panel  16  increases at a portion near the door central portion, thereby preventing the inner panel  16  from being deformed. 
     The inner reinforcement  25  is located on the rear side of the lower sash  22  in the front-rear direction. The mirror attachment portion  51  is configured to be attached to the inner panel  16  on the front side of the lower sash  22  in the front-rear direction. This structure prevents the inner reinforcement  25  from covering the fixing portions  58   a  at which the mirror attachment portion  51  and the inner panel  16  are attached, thereby making it easy to fix the mirror attachment portion  51  and the inner panel  16  with the rivets  64  or by welding. 
     The inner reinforcement attachment portion  52  to which the inner reinforcement  25  is fixed is located at a more inner position of the vehicle  1  than the mirror attachment portion  51  fixed to the lower sash  22 . With this structure, the inner reinforcement  25  can be disposed at a more inner position of the vehicle  1  than the lower sash  22  guiding the door glass  13 , thereby preventing interference between the inner reinforcement  25  and the door glass  13 . 
     The embodiment of the invention is exemplified as described above. The embodiment and modifications described above are provided by way of example only and not intended to limit the scope of the invention. The embodiment and the modifications can be implemented by other various forms, and can be omitted, replaced, or modified in various ways without departing from the scope of the invention. The structures and shapes of the respective embodiments and modifications can also be implemented by partially replacing them.