Patent Publication Number: US-2016236545-A1

Title: Vehicle door structure

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2015-029593 filed on Feb. 18, 2015, the disclosure of which is incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a vehicle door structure. 
     2. Related Art 
     Conventional vehicle door structures are known in which a door sash (door frame) is formed bent into a substantially rectangular shape in cross-section orthogonal to the length direction, thus improving the rigidity of the door sash (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2012-101563). 
     However, when the door is manufactured by forming the door frame bent into a substantially rectangular shape in cross-section orthogonal to the length direction, there is a concern that the manufacturing process of this door becomes complicated. 
     SUMMARY 
     An object of the present invention is to obtain a vehicle door structure capable of increasing the productivity for manufacturing a door, while securing the rigidity of a door frame. 
     In order to realize the above object, a vehicle door structure of a first aspect of the present invention includes: a frame inner that is formed in an “L” shape in cross-section orthogonal to a length direction and that configures an inner wall portion at a door thickness direction inside of a door frame and an upper wall portion at a door up-down direction upper side of the door frame; and a frame outer that is formed in an “L” shape in cross-section orthogonal to the length direction, that configures an outer wall portion at the door thickness direction outside of the door frame and a lower wall portion at the door up-down direction lower side of the door frame, wherein a door up-down direction upper side end portion of the outer wall portion is welded to a door thickness direction outside end portion of the upper wall portion, and a door thickness direction inside end portion of the lower wall portion is welded to a door up-down direction lower side end portion of the inner wall portion, so as to configure a closed cross-section profile together with the frame inner. 
     In the first aspect of the present invention, the frame inner formed in an “L” shape in cross-section orthogonal to the length direction and the frame outer formed in an “L” shape in cross-section orthogonal to the length direction are welded together, thereby forming the door frame with a closed cross-section profile. Productivity of manufacturing the door is thereby increased while securing the rigidity of the door frame, compared to a configuration in which a door frame is formed by being bent into a rectangular shape in cross-section orthogonal to the length direction to form a closed cross-section profile. Note that the “L” shape of the present invention also includes substantially “L” shapes. 
     A vehicle door structure of a second aspect of the present invention is the vehicle door structure of the first aspect, wherein the door up-down direction upper side end portion of the outer wall portion is in face-to-face contact with the door thickness direction outside end portion of the upper wall portion, and the door thickness direction inside end portion of the lower wall portion is in face-to-face contact with the door up-down direction lower side end portion of the inner wall portion. 
     In the second aspect of the present invention, the end portions of the frame inner and the end portions of the frame outer are respectively welded together in face-to-face contact. Positional misalignment when the end portions of the frame inner and the end portions of the frame outer are welded together is thereby suppressed, and the assembly accuracy is improved. 
     A vehicle door structure of a third aspect of the present invention is the vehicle door structure of the first aspect or the second aspect, wherein a weld location of the door up-down direction upper side end portion of the outer wall portion welded to the door thickness direction outside end portion of the upper wall portion, and a weld location of the door thickness direction inside end portion of the lower wall portion welded to the door up-down direction lower side end portion of the inner wall portion, are both locations that are furthest away from the centroid of the closed cross-section profile. 
     In the third aspect of the present invention, the end portions of the frame inner and the end portions of the frame outer are respectively welded together at locations that are furthest away from the centroid of the closed cross-section profile. This enables the rigidity of the door frame to be improved compared to a configuration in which the end portions of the frame inner and the end portions of the frame outer are not welded together at locations that are furthest away from the centroid of the closed cross-section profile. 
     A vehicle door structure of a fourth aspect of the present invention is the vehicle door structure of any one of the first aspect to the third aspect, wherein the door thickness direction outside end portion of the upper wall portion projects out further toward the door thickness direction outside than the door up-down direction upper side end portion of the outer wall portion, and the door up-down direction lower side end portion of the inner wall portion projects out further toward the door up-down direction lower side than the door thickness direction inside end portion of the lower wall portion. 
     In the fourth aspect of the present invention, the end portions of the frame inner are formed longer than the end portions of the frame outer (the end portions of the frame outer are formed shorter than the end portions of the frame inner). The end portions of the frame inner and the end portions of the frame outer are thereby easily joined together by laser welding with filler wire. 
     A vehicle door structure of a fifth aspect of the present invention is the vehicle door structure of any one of the first aspect to the fourth aspect, wherein a frame garnish is disposed in close proximity to the door up-down direction lower side end portion of the inner wall portion and to a bent portion of the frame outer. 
     In the fifth aspect of the present invention, the frame garnish is disposed in close proximity to the door up-down direction lower side end portion of the inner wall portion and to the bent portion of the frame outer. This enables the visibility from a vehicle cabin side to be improved by widening. 
     A vehicle door structure of a sixth aspect of the present invention is the vehicle door structure of any one of the first aspect to the fifth aspect, wherein the frame inner and the frame outer are each made of an aluminum alloy. 
     In the sixth aspect of the present invention, the frame inner and the frame outer are each made of an aluminum alloy. Note that the manufacturing process of an aluminum alloy door frame formed by being bent becomes complicated; however, the manufacturing process of the door frame formed by welding together the frame inner and the frame outer does not become complicated. Productivity of manufacturing the door made of an aluminum alloy is thereby increased. 
     The first aspect of the present invention enables productivity of manufacturing the door to be increased, while securing the rigidity of the door frame. 
     The second aspect of the present invention enables positional misalignment when respectively welding together the end portions of the frame inner and the end portions of the frame outer to be suppressed, enabling the assembly accuracy to be improved. 
     The third aspect of the present invention enables the rigidity of the door frame to be improved. 
     The fourth aspect of the present invention enables the end portions of the frame inner and the end portions of the frame outer to be easily joined together by laser welding with filler wire. 
     The fifth aspect of the present invention enables the visibility from the vehicle cabin side to be improved by widening. 
     The sixth aspect of the present invention enables the productivity of manufacturing the door made of an aluminum alloy to be increased. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a side view illustrating a door including a vehicle door structure according to an exemplary embodiment; 
         FIG. 2  is a cross-section along arrow line X-X in  FIG. 1 ; and 
         FIG. 3  is a cross-section illustrating a vehicle door structure according to a comparative example superimposed on a vehicle door structure according to the present exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed explanation follows regarding an exemplary embodiment of the present invention, based on the drawings. Note that for ease of explanation, in each of the drawings, the arrow UP indicates the door upper direction, the arrow FR indicates the door front direction, and the arrow OUT indicates the door thickness direction outside as appropriate. In the below explanation, unless specifically stated otherwise, reference to the up-down, front-rear, and inside-outside directions indicates up-down in the door up-down direction, front-rear in the door front-rear direction, and inside-outside in the door thickness direction. 
     As illustrated in  FIG. 1 , a door frame  14  (door sash) configuring a window frame is provided at an upper portion side of a door  12  including a vehicle door structure  10  according to the present exemplary embodiment. As illustrated in  FIG. 2 , the door frame  14  is configured with a closed cross-section profile by joining together an aluminum alloy frame inner  20  formed in a substantially “L” shape in cross-section orthogonal to the length direction, and an aluminum alloy frame outer  30  formed in a substantially “L” shape in cross-section orthogonal to the length direction. 
     To explain in detail, the frame inner  20  includes an inner wall portion  22  that configures the door thickness direction inside of the door frame  14 , and an upper wall portion  24  that configures the door up-down direction upper side of the door frame  14 . A boundary portion between the inner wall portion  22  and the upper wall portion  24  forms a bent portion  26  that is bent in an obtuse angle in cross-section view orthogonal to the length direction. 
     The frame outer  30  includes an outer wall portion  32  that configures the door thickness direction outside of the door frame  14 , and a lower wall portion  34  that configures the door up-down direction lower side of the door frame  14 . A boundary portion between the outer wall portion  32  and the lower wall portion  34  forms a bent portion  36  that is bent in substantially a right angle in cross-section view orthogonal to the length direction. Note that the outer wall portion  32  is bent in a substantially “S” shape in the cross-section view illustrated in  FIG. 2 . 
     An upper flange portion  32 A serving as a door up-down direction upper side end portion of the outer wall portion  32  is in face-to-face contact with, and joined by laser welding with filler wire to, an outer flange portion  24 A serving as a door thickness direction outside end portion of the upper wall portion  24 . An inner flange portion  34 A serving as a door thickness direction inside end portion of the lower wall portion  34  is in face-to-face contact with, and joined by laser welding with filler wire to, a lower flange portion  22 A serving as a door up-down direction lower side end portion of the inner wall portion  22 . The door frame  14  is thereby formed with a substantially rectangular shaped closed cross-section profile. 
     The outer flange portion  24 A of the upper wall portion  24  projects out further toward the door thickness direction outside than the upper flange portion  32 A of the outer wall portion  32 . The lower flange portion  22 A of the inner wall portion  22  projects out further toward the door up-down direction lower side than the inner flange portion  34 A of the lower wall portion  34 . The configuration thereby enables laser welding with filler wire to be performed. Note that laser welding with filler wire is a method of laser welding performed while supplying a filler wire serving as a weld material from the exterior. 
     A weld location  38  of the upper flange portion  32 A of the outer wall portion  32  to the outer flange portion  24 A of the upper wall portion  24  by laser welding with filler wire is a location that is furthest away from the centroid P of the closed cross-section profile. Similarly, a weld location  28  of the inner flange portion  34 A of the lower wall portion  34  to the lower flange portion  22 A of the inner wall portion  22  by laser welding with filler wire is a location that is furthest away from the centroid P of the closed cross-section profile. 
     Namely, locations that are furthest away from the centroid P of the closed cross-section profile configure the weld locations  28 ,  38 . Note that the shape of the frame outer  30  is determined from the perspectives of improving the rigidity of the door frame  14 , and improving visibility, described later. A frame garnish  40  is provided to the inner wall portion  22  and the lower wall portion  34  that face a vehicle cabin side of the door frame  14 , so as to cover at least the inner wall portion  22  and the lower wall portion  34 . 
     The frame garnish  40  includes an inner wall portion  42  that is disposed alongside the inner wall portion  22  of the frame inner  20 , and that covers the inner wall portion  22  as far as and including the bent portion  26 , and a flat plate shaped lower wall portion  44  that is disposed in close proximity to a leading end face of the lower flange portion  22 A of the inner wall portion  22  of the frame inner  20 , and an outer face of the bent portion  36  of the frame outer  30 . A boundary portion between the inner wall portion  42  and the lower wall portion  44  configures a bent portion  46  that is bent in an acute angle in cross-section view orthogonal to the length direction. 
     A first weather strip  52 , serving as a main weather strip, is provided at an inside upper face of the upper wall portion  24  of the frame inner  20 . A door thickness direction inside end portion of the first weather strip  52  covers a door thickness direction outside end portion  42 A of the inner wall portion  42  of the frame garnish  40  from above. 
     A second weather strip  54  is provided at an outer face side of the outer wall portion  32  of the frame outer  30  by fitting respective groove portions  54 A together with a door thickness direction outside end portion  44 A of the lower wall portion  44  of the frame garnish  40 , and the outer flange portion  24 A of the upper wall portion  24  of the frame inner  20 . 
     The first weather strip  52  and the second weather strip  54  are contiguously joined together by a third weather strip  56  provided at an outside upper face of the upper wall portion  24 . Note that, when side window glass  48  is closed, an upper end portion  48 A thereof is inserted inside an insertion portion  54 B formed to the second weather strip  54 . 
     An opening weather strip  50  is provided by being fitted together with a panel  16  that configures the vehicle cabin. Thus, when the door  12  is closed, the inner wall portion  42  of the frame garnish  40  abuts the opening weather strip  50  with a specific pressure. When the door  12  is closed, the first weather strip  52  and the third weather strip  56  abut a panel  18  configuring the roof of the vehicle with a specific pressure. 
     Explanation follows regarding operation of the vehicle door structure  10  according to the present exemplary embodiment configured as described above. 
     First, explanation follows regarding a door frame  60  according to a comparative example, illustrated by the hypothetical lines in  FIG. 3 . The door frame  60  is configured by a frame inner  62  formed by being bent into a substantially “C” shape in cross-section orthogonal to the length direction, and a frame outer  64  that closes off an open side of the frame inner  62 . Namely, the door frame  60  is formed with a substantially rectangular shaped closed cross-section profile by respectively welding an upper flange portion  64 A and a lower flange portion  64 B of the frame outer  64  to an upper wall portion  62 A and a lower wall portion  62 B of the frame inner  62 . 
     In contrast thereto, the door frame  14  according to the present exemplary embodiment is formed with a substantially rectangular shaped closed cross-section profile by respectively welding the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20  formed in a substantially “L” shape in cross-section orthogonal to the length direction, to the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30  formed in a substantially “L” shape in cross-section orthogonal to the length direction. Thus the door frame  14  according to the present exemplary embodiment has higher rigidity than the door frame  60  according to the comparative example. 
     Moreover, when the door frame  60  according to the comparative example is made of an aluminum alloy, and the frame inner  62  is formed bent into a substantially “C” shape in cross-section orthogonal to the length direction, a bending process performed by a roller or the like, not illustrated in the drawings, is required, such that the manufacturing process becomes complicated. 
     In contrast thereto, the frame inner  20  and the frame outer  30  that configure the door frame  14  according to the present exemplary embodiment and each have a substantially “L” shaped cross-section can be easily manufactured by press forming, such that the above-described bending process using a roller or the like is not required. Namely, in the case of the door frame  14  according to the present exemplary embodiment, the manufacturing process is not complicated, even when made of an aluminum alloy. 
     The door frame  14  according to the present exemplary embodiment accordingly enables the productivity of manufacturing a door  12  made of an aluminum alloy to be increased, compared to the door frame  60  according to the comparative example. Namely, the vehicle door structure  10  according to the present exemplary embodiment can be particularly effectively applied in cases in which the door  12  is made of an aluminum alloy. 
     In the configuration of the door frame  60  according to the comparative example, there is a concern that weld positions of the frame outer  64  to the frame inner  62  may be misaligned in the door thickness direction. However, in the door frame  14  according to the present exemplary embodiment, the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30  are respectively welded in face-to-face contact with the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20 , such that the weld positions are unambiguously determined, and there is no concern of misalignment. 
     Namely, in the case of the door frame  14  according to the present exemplary embodiment, position misalignment of the weld positions can be prevented or suppressed when respectively welding together the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20 , and the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30 , enabling the assembly (weld position) accuracy to be improved. 
     In the door frame  14  according to the present exemplary embodiment, the lower flange portion  22 A of the frame inner  20  and the inner flange portion  34 A of the frame outer  30  are welded together at the weld location  28  that is furthest away from the centroid P of the closed cross-section profile. Furthermore, the outer flange portion  24 A of the frame inner  20  and the upper flange portion  32 A of the frame outer  30  are welded together at the weld location  38  that is furthest away from the centroid P of the closed cross-section profile. 
     Namely, the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20 , and the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30 , are respectively welded together at the weld locations  28 ,  38  that are furthest away from the centroid P of the closed cross-section profile. This enables the rigidity of the door frame  14  to be improved, compared to configurations in which welding is not performed at locations that are furthest away from the centroid P of the closed cross-section profile. 
     In the door frame  14  according to the present exemplary embodiment, the outer flange portion  24 A of the upper wall portion  24  of the frame inner  20  projects out further toward the door thickness direction outside than the upper flange portion  32 A of the outer wall portion  32  of the frame outer  30 , and the lower flange portion  22 A of the inner wall portion  22  of the frame inner  20  projects out further toward the door up-down direction lower side than the inner flange portion  34 A of the lower wall portion  34  of the frame outer  30 . 
     In other words, the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20  are formed longer than the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30  (the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30  are formed shorter than the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20 ). 
     This enables the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30  to be easily respectively joined by laser welding with filler wire to the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20 . 
     In the door frame  14  according to the present exemplary embodiment, the lower wall portion  44  of the frame garnish  40  is disposed in close proximity to the lower flange portion  22 A of the inner wall portion  22  of the frame inner  20 , and to the bent portion  36  of the frame outer  30 . Namely, in cross-section view orthogonal to the length direction, the lower wall portion  44  is disposed bent in an acute angle with respect to the inner wall portion  42  of the frame garnish  40  disposed alongside the inner wall portion  22  of the frame inner  20 . 
     As illustrated in  FIG. 3 , in the frame inner  62  of the door frame  60  according to the comparative example, an angle formed by an inner wall portion  62 C and the lower wall portion  62 B configures substantially a right angle in cross-section view orthogonal to the length direction. The closed cross-section profile of the door frame  60  according to the comparative example is thereby larger than the closed cross-section profile of the door frame  14  according to the present exemplary embodiment. 
     In other words, when the cross-section of the inner wall portion  62 C and the upper wall portion  62 A of the frame inner  62  is illustrated superimposed on the cross-section of the inner wall portion  22  and the upper wall portion  24  of the frame inner  20 , the lower wall portion  62 B of the frame inner  62  juts out further toward the door up-down direction lower side than the lower wall portion  34  of the frame outer  30 . 
     A frame garnish  66  of the door frame  60  according to the comparative example is thereby disposed further toward the door up-down direction lower side than the lower wall portion  62 B of the frame inner  62 , and blocks visibility from the vehicle cabin side more than the frame garnish  40  according to the present exemplary embodiment. Namely, the door frame  14  according to the present exemplary embodiment enables the visibility from the vehicle cabin side to be widened by at least the amount of a width W compared to the door frame  60  according to the comparative example, and enables impairment to visibility from the vehicle cabin side to be ameliorated. 
     The vehicle door structure  10  according to the present exemplary embodiment has been explained above based on the drawings; however, the vehicle door structure  10  according to the present exemplary embodiment is not limited to that illustrated, and suitable design modifications may be implemented within a range not departing from the spirit of the present invention. For example, the door frame  14  according to the present exemplary embodiment is not limited to being made of an aluminum alloy, and may be made of steel or resin. When made of resin, the frame inner  20  and the frame outer  30  may be joined together by adhesive. 
     The door frame  14  according to the present exemplary embodiment is not limited to a configuration that is joined together by laser welding with filler wire, and may be a configuration that is joined together by normal laser welding, spot welding, or the like. There is accordingly no limitation to a configuration in which the lower flange portion  22 A and the outer flange portion  24 A of the frame inner  20  are formed longer than the inner flange portion  34 A and the upper flange portion  32 A of the frame outer  30 .