Vehicle assembling method and vehicle body structure

Abstract: A vehicle assembling method comprising steps of assembling lower body shell (BL) including underbody portion (BD) having a front floor (1) and front body portion (BF), assembling upper body shell (BU) including roof member, right and left body side panels (11), and assembling the upper body shell (BU) and the lower body shell (BL), moving rearward the lower body shell (BL) relative to the upper body shell (BU), engaging transverse opposite side ends of the lower body shell (BL) with lower end portions of the upper body shell (BU) to join the lower body shell (BL) with the upper body shell (BU). The under body portion (BD) can be readily joined with the upper body shell (BU) improving the workability of the joining. The structure of joint portion thereof can be simplified with a desirable sealing.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a vehicle assembling method in which an upper body shell and lower body shell are assembled separately and thereafter the lower body shell is moved to the upper body shell to be combined with the upper body shell. Description of the Prior Art Generally, a conventional vehicle assembling process includes a pressing process in which a steel plate is processed, a body assembling process in which the body shell is assembled, an application process in which coating material is applied on the vehicle body surface, equipping process in which various fit-in parts are equipped for vehicle structure. Conventionally, an underbody portion including floor member, a front body portion, a rear body portion, a body side panel, roof member and the like are sub-assembled in order to form a body shell. Thereafter, the equipping process is applied on the body. It should however be noted that it is difficult to automate the equipping process because the assembled body shell will hinder the equipping operation. In view of this, it has been proposed that a vehicle assembling process can be done efficiently as much automated as possible. For example, JP-A-63-235174, laid open to the public in 1988, discloses a vehicle assembling process including steps of assembling the front body portion defining engine room, under body portion including the front floor and center floor and rear floor, upper body shell including body side panel and roof member, fit-in parts, assembling the under body portion and front body portion to form lower body shell, mounting the upper body shell on the lower body shell. In JP-U-64-28377, there is disclosed a vehicle assembling process including steps of assembling lower body shell including front body portion and under body portion, and upper body shell including body side panel, roof member and cowl member, equipping these body panels, joining the upper body shell with the lower body shell. Meanwhile, the upper body shell is formed with side sill upper and the lower body shell is formed with the side sill lower. When the side sill upper and the side sill lower are combined, a whole side sill structure is formed. In the above assembling techniques, the floor member is formed at side ends with downwardly extending flange portion which is joined with a flange of the side sill by a plurality of bolts. It is however noted that joining the floor member with the side sill is not easy because a plurality of openings for inserting the bolts must align with each other. Another reason is that as manufacturing error of the floor member and the upper body shell increases, the flange portion of the floor panel is more difficult to be fitted with the flange of the side sill. As a result, it becomes difficult to combine the floor panel and the side sill. Otherwise, the joint of the floor panel and the side sill is less reliable. In the assembling technique as disclosed in JP-U-64-28377, it is necessary to join horizontal flanges of a side sill upper and lower when the upper body shell is combined with the lower body shell. It should be, however, noted that it is difficult to joint the horizontal flanges of the side sills where the upper and lower body shell are not processed accurately. If they are joined by welding, coating of the body shell would be injured. The body shells cannot be smoothly joined by automatic assembling method because of manufacturing error. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle assembling method in which upper body and lower body shells can be readily desirably joined. It is another object of the present invention to provide a vehicle assembling method which can improve workability in equipping the vehicle body. The above and other object of the present invention can be accomplished by a vehicle assembling method comprising steps according to claim 1 and by a vehicle body structure according to claim 18. In a preferred embodiment, the lower body shell including the under body portion and front body portion integrated with the under body portion is equipped with parts. Thereafter, the lower body shell is joined with the upper body shell. In another embodiment, the under body portion and the front body portion which is not joined with the front body portion are equipped with parts respectively. Thereafter, the both body portions are joined with the upper body shell. In further embodiment, the under body portion and the front body portion which is not joined with the under body portion are equipped with parts separately. Thereafter, the front body portion is joined with the upper body shell and the under body portion. In still another embodiment, one of the upper body shell, the under body shell and the front body shell, on which the most burdensome equipping process is needed, is supplied to a main equipping line. In addition, the right and left ends of the front floor is joined with at least the right and left bearing portions of the side sills. In another aspect of the present invention, a vehicle assembling method comprising steps of assembling roof member with upper body shell including body side panel and right and left side sills, assembling lower body shell including under body portion having a front floor and front body portion, and assembling the upper body shell and the lower body shell, the improvement further comprising steps of forming bearing portion on right and left side sills of the upper body shell for bearing right and left ends of the under body portion, carrying forwardly the upper body shell and lower body shell to equipping lines and equipping the upper and lower body shells respectively, carrying the under body portion rearward in longitudinal direction of the vehicle relative to the upper body shell and engage the right and left ends of the under body portion with the right and left bearing portions of the upper body shell and joining the right and left ends of the under body portion with the right and left lower ends of the upper body shell. According to the present invention, the upper body shell and the lower body shell are assembled separately. Thereafter, the upper and lower body shells are joined together. In this process, the upper body shell and the lower body shell are introduced into the respective equipping lines to be equipped with fit-in parts. As a result, the workability and working efficiency can be improved in equipping process of the both body shells. Then, the under body portion is moved rearward relative to the upper body shell so that the right and left ends of the front floor are engaged and joined with the bearing portions of the right and left side sills. It will be understood that the under body is moved rearward to the upper body shell to be readily joined with each other. The front floor can be reliably and desirably engaged and joined with the upper body shell. In another aspect of the present invention, after equipping the lower body shell integral with the front body with fit-in parts, the lower body shell is joined with the upper body shell. The equipping process can be advanced remarkably for the lower body shell. The lower body shell can be transferred by a separate line. In still another embodiment, the front body separate from the under body are combined with each other. Then, the both body portions are joined. The joined body portion is joined with the upper body shell. In this process, the equipping workability can be improved for both the under body portion and the front body portion. The burden in joining the upper body shell with the lower body shell can be reduced. In another aspect of the present invention, after the under body portion and the front body portion which is separated from the under body portion are equipped with parts respectively, the front body portion and the upper body shell are joined with the under body portion. The workability of the equipping for the under body and front body portions can be improved. The upper body shell can be readily joined with the under body portion. In still another aspect of the present invention, the most burdensome one of the upper body shell, under body and front body portions in equipping is introduced into the main equipping line. The main equipping line can be economically automated. Alternatively, the right and left ends of the front floor is attached to at least the right and left bearing portions of the under body shell. In this method, the under body portion can be readily joined with the upper body shell improving the workability of the joining. The structure of joint portion thereof can be simplified with a desirable sealing. In further aspect of the present invention, the upper body shell is formed with the right and left bearings at the lower ends thereof. The right and left ends of the under body portion are engaged with the bearing portions of the upper body shell. For example, the upper body shell is formed with a part of side sills as the bearing portions at the right and left lower ends thereof so as to bear the under body shell. Alternatively, the under body portion is formed with a part of the side sills as the bearing portions at the right and left ends thereof so as to bear the upper body shell. Further objects, features and advantages of the present invention will become apparent from the Detailed Description of Preferred Embodiments which follows when read in light of the accompanying Figures. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow diagram of vehicle assembling process; Figure 2 is exploded perspective view of upper body shell, under body portion and front body portion; Figure 3 is a sectional view of a joint structure of side sill and front floor; Figure 4 is a similar view to Figure 3 but showing another structure; Figure 5 is a similar view to Figure 3 but showing still another structure; Figure 6 is a similar view to Figure 3 but showing further structure; Figure 7 is a similar view to Figure 3 but showing still further structure; Figure 8 is a similar view to Figure 3 but showing yet another structure; Figure 9 is a similar view to Figure 3 but showing another structure; Figure 10 is a similar view to Figure 3 but showing yet further structure; Figure 11 is a similar view to Figure 3 but showing further structure; Figure 12 is a perspective view showing side sill and front floor; Figure 13 is a similar view to Figure 3 but showing another structure; Figure 14 is a perspective view of essential portion of joint structure of the hinge pillar; Figure 15 is a sectional view taken by a line 15-15 in Figure 14; Figure 16 is a similar view to Figure 15 but showing another structure; Figure 17 is a similar view to Figure 15 but showing still another structure; Figure 18 is a similar view to Figure 15 but showing another structure; Figure 19 is a similar view to Figure 15 but showing another structure; Figure 20 is a perspective view showing body assembling line; Figure 21 is a perspective view of assembling fixture; Figure 22 is an elevational view of the assembling fixture; Figure 23 is a plan view of the assembling fixture; Figure 24 is a front view of the assembling fixture; Figure 25 is a perspective view for explaining body assembling process; Figure 26 is another perspective view for explaining body assembling process; Figure 27 is a front view of conveying device; Figure 28 is a perspective view of door supply robot and joining device; Figure 29 is a front view of lift; Figure 30 is a perspective view for explaining the body assembling process; Figure 31 is a diagram showing application process; Figure 32 is a perspective view of under body shell, body member and application fixture; Figure 33 is a perspective view of the fixture of Figure 32; Figure 34 is a perspective view showing retaining mechanism; Figure 35 is a sectional view taken by a line 35-35 in Figure 32; Figure 36 is a perspective view similar to Figure 33 but showing another structure; Figure 37 is a perspective view showing vehicle assembling line; Figure 38 is a perspective view of a conveying truck; Figure 39 is a view similar to Figure 38 but showing another structure; Figure 40 is a perspective view showing equipping line Figure 41 is a perspective view of essential portion of the equipping line; Figure 42 is a perspective view of under body portion and front body portion in joining process; Figure 43 is a perspective view of upper body shell and lower body shell in joining process; Figure 44 is side view of joining station for joining upper and lower body shells; Figure 45 is a front view of joining station; Figure 46 is side view of joining station for mounting lower unit; Figure 47 is a view showing vehicle assembling process of another embodiment; Figure 48 is a perspective view of joining process of upper body shell and under body shell; Figure 49 is a perspective view of upper body shell and lower body shell in the joining process in accordance with another embodiment; Figure 50 is a view similar to Figure 2 but showing another embodiment; Figure 51 is a view similar to Figure 2 but showing another embodiment; Figure 52 is a view of vehicle assembling process in accordance with another embodiment; Figure 53 is a view of joint structure similar to Figure 3 but showing another structure; Figure 54 is exploded perspective view of the vehicle body in accordance with another embodiment; Figure 55 is a perspective view showing a side sill; Figure 56 is a sectional view of joint portion between the floor and the side sill; Figures 57 through 68 are sectional views showing other joint structures between the floor and side sill respectively in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in Figure 1, a vehicle assembling process includes press molding process, body assembling process, application process and vehicle assembling process. In the body assembling process, as shown in Figure 2, upper body shell BU and lower body shell BL including under body portion BD and front body portion BF are assembled in the respective assembling lines. In the application process, application process is made on the upper body shell BU and the lower body shell BL respectively. In the vehicle assembling process, the fit-in or equipping process is made on the upper body shell BU and the lower body shell. Thereafter, the under body portion BD and the front body portion BF are moved rearward in a longitudinal direction of the vehicle relative to the upper body shell BU to be joined with each other to assemble a body shell B on which a unit 160 is mounted. The press molding process is well known to the skilled in the art. Therefore, detailed explanation is omitted. Referring to Figures 2 through 19, the under body portion BD includes front floor 1, right and left front frames, shaft tunnel 2, second cross member 3, right and left seat bracket 4 and the like. As shown in Figure 3, the front floor 1 includes a honeycomb base plate 1a of aluminum or aluminum alloy and upper and lower plates 1b of aluminum or aluminum alloy attached to the upper and lower sides of the base plate 1a. The upper and lower plates 1b can be made of steel. Front body portion BF includes right and left front side frames 7, wheel apron 9, cowl dash structure 10, dash lower panel 5, closed cross-sectioned structure 6A forming a front portion of hinge pillar 6 (see Fig. 15). Upper body shell BU includes body side panel 11 for forming a vehicle side structure, rear body 12 for forming a rear body portion, roof panel 13 for forming a vehicle upper portion. The body side panel 11 includes side outer panel 14 and side inner panel 15 which form a front pillar 16 of a closed cross sectioned structure, a closed cross section 6B forming a front portion of hinge pillar 6, center pillar 18, rear pillar 19, right and left side sills 20 and the like. The rear body 12 includes rear floor, main center floor 40, right and left rear frame 21, third cross member 41, fourth cross member and the like. As shown in Figure 3, inner side of the side sill 20 is formed with bearing member 31 of aluminum or aluminum alloy which is formed by extrusion molding is disposed from front end to rear end of the side sill 20. The bearing member 31 is fixed to the side sill 20 by means of bolt 32 or welding. The bearing member 31 is formed with upper and lower bearing portions 31a, 31b extending inwardly. There is formed engaging groove 33 defined by the bearing portions 31a, 31b and extended across the side sill 20 for receiving right and left ends of the front floor 1. The front floor 1 is slid into the right and left grooves 33 so that the under body portion BD is assembled with lower portion of the upper body shell BU. In this case, adhesive is applied onto the grooves 33 prior to the assembly of the under body portion BD. Sealing effect can be obtained. The adhesive can be applied after insertion of the front floor 1 into the grooves 33. Bolt can be employed for fixing the front floor 1 to the upper body shell BU. The front floor 1 may be made of fiber reinforced synthetic resin. When the front floor 1 is made of steel front floor 1A, as shown in Figure 4, a L-shaped bearing member 31A is fixed to lower and inner portion of the side sill 20 by means of bolt or welding to form a groove 34 between bearing portions 31c and 31d. Alternatively, as shown in Figure 5, upper and lower L-shaped bearing members 31B are fixed to the inner and lower portion of the side sill 20 so as to form engaging groove 34A therebetween to which the front floor 1A is inserted. As shown in Figure 6, the side sill 20A is formed at the inner lower ends of the side sill 20A with a bearing portion 35A projected horizontally and inwardly and extended from front end to rear end for bearing one of the right and left ends of front floor 1. The front floor 1 is inserted into the bearing portion 35A and fixed thereto by means of bolt or welding. In this case, as shown by a phantom line, a reinforcement 35C forming closed-cross sectioned structure may be provided integrally on the side sill 20A. As shown in Figure 7, side sill 20B is formed with a bearing portion 35B on the intermediate portion in parallel with the bearing portion 35A to form engaging groove 33A between the bearing portions 35A and 35B for receiving the front floor 1 which is fixed to the side sill 20B by means of bolt or welding or the like. Polyurethane foam 35E is filled in the inner space of the closed cross sectioned structure defined by the side sill 20B. As shown in Figure 8, adhesive 30 may be filled between bearing portion 35D and the front floor 1. In this case, distance between the two bearing portions 35A and 35D are broadly provided. Alternatively, as shown in Figure 9, side sill 20D is formed at inner lower and middle portions with bearing portions 35F and 35G of closed cross-sectioned structures. Engaging groove 33A is formed between the bearing portions 35F and 35G. The width of the groove 33A becomes gradually broader toward the bottom thereof. Adhesive 30 is filled in the engaging groove 33A. Thereafter, the under body portion BD is joined with the upper body shell BU. As shown in Figure 10, it is also preferable that a plurality of through holes 36a with a certain interval are provided on the bearing portion 35G which communicate with inside of the groove 33A. In this structure, when the front floor 1 is inserted into the engaging groove 33A, the adhesive 30 is introduced into the groove 33A for fixing the upper body shell BU and the under body shell BD through the side sill 20E. As shown in Figures 11 and 12, side sill 20F is formed at inner and lower portion thereof with engaging groove 33B and bearing portion 35H. The side sill 20F is also formed at inner and upper portion thereof with T-shaped engaging groove 38. Engaging portion 37A of the front floor 1 is engaged with the engaging groove 33B so that the bearing portion 35H supports the front floor 1. Outer end of the second cross member is joined with the side sill 20A through engaging member 39 which is received by the engaging groove 38. As shown Figure 13, side sill 20G is formed at middle and lower outer portions thereof with engaging grooves 33C and 33D with which engaging portions 37B and 37C formed at outer end portions of the front floor 1 made of FRP cooperate so that bearing portion 35I supports the front floor 1. The third cross member 41 is formed at front end portion with a flange portion extending in the transverse direction of the vehicle. The front floor 1 which is engaged with the upper body shell BU is engaged with the front flange of the third cross member 41 at rear end portion by means of adhesive or bolt. Alternatively, the third cross member 41 is provided with bearing member constituted by a channel member along the rear end of the front floor 1 so that the rear end of the front floor 1 is engaged and fixed with groove defined by the bearing member through adhesive or bolt. Referring to Figures 14 and 15, there are provided a pair of closed cross sectioned structures 6A and 6B having split surfaces 6a, which form a hinge pillar 6. As shown in Figure 2, the front body portion BF is assembled with the upper body shell BU wherein the closed cross sectioned structures 6A and 6B are joined. The front body portion BF and the upper body shell BU are formed with the closed cross sectioned structures 6A and 6B respectively. This enhances the strength and rigidity of the respective members BF and BU. Reference 17 shows a reinforcement of instrument panel. The reinforcement 17 is joined with the closed cross sectioned structure 6A of the front body portion BF. Alternatively, the hinge pillar 6 can be separated by split surfaces 6b extending transversely to form a pair of closed cross sectioned structures 6C and 6D. As shown in Figures 17 and 14, the hinge pillar 6 is divided by split surfaces 6c into closed cross sectioned structures 6E and 6F in the body structures BF and BU. The split surfaces 6c extends transversely and forwardly downwardly. As shown in Figure 18, the hinge pillar can be formed on the upper body shell BU. Alternatively, as shown in Figure 19, hinge pillar inner 6G is formed on the front body portion and hinge pillar outer 6H is formed on the upper body shell BU so that the hinge pillar 6 is formed when the front body portion BF is joined with the upper body portion BU. Where the side sill as shown in Figures 6 through 11 is used, a lower end of the hinge pillar 6 is fixed to the side sill through bolt and the like. The front body portion BF is formed with transverse flange portion at the rear end portion of the dash lower panel. The front floor 1 is engaged with the flange portion of the front body portion BF and fixed thereto by means of the adhesive and bolt. Alternatively, the front floor 1 is provided with transverse bearing member of a channel structure in section along the front end thereof. The bearing member defines engaging groove with which the front end portion of the front floor 1 is engaged and fixed by means of the adhesive and bolt. Body Assembling Process The upper body shell BU and the under body portion BD and front body portion BF are assembled in respective assembling lines. The upper body shell BU is assembled in upper body shell assembling line BUL. The assembling line BUL includes nine stations S1-S9 to which assembling fixture JU is transferred in order. On the fixture JU are assembled body members with inner panel which is a reference member so that upper body structure BU is assembled. A plurality of fixtures are prepared for respective kinds of vehicle and placed at fixture station ST. Conveyer can be constituted by linear system or lift and carry system which are conventionally known. Referring to Figures 21 through 24, the fixture JU includes pallet P, RF retainer for positioning rear body 12, right and left SP retainer for positioning and fixing side panel 15, RH retainer for positioning and fixing front header 22 and rear header 23 of the roof panel 13. The pallet is provided with a right and left brackets 45 spaced longitudinally from each other at the rear end. The bracket 45 is provided with positioning pin 46 and clamp C1. Right and left rear frames 21 of the rear body 12 is positioned at four points in the front and rear ends by means of four positioning pins 46 so as to be positioned and fixed to the pallet P through the clamp C1. The SP retainer is provided for positioning and fixing right and left side panels 15. The SP retainer is provided at right side and left side. Stationary base 47 is disposed at left side of the pallet P. Supporting plate 48 is disposed on the stationary base 47 for transverse movement. The supporting plate 48 is provided with F-shaped support frame 49 having a pair of front and rear vertical columns 49a on which clamps C2 are mounted for roof rail inner formed at upper end portion of the side inner panel 15. The support plate 48 is provided with positioning device P1 for positioning middle portion of center pillar inner 18A and clamp C3 for fixing the middle portion of the center pillar inner 18A. Horizontal member 49b of the support frame 49 is provided at rear end portion with positioning device P2 for positioning lower end of rear inner 19A of the side inner panel 15 and clamp C4 for fixing the rear pillar inner 19A. On pallet P in front of the stationary base 47 is disposed support base 50 on which a movable plate 51 is disposed for transverse movement. On the movable plate 51 is disposed a vertical column 52 on which channel-like support frame 53 is mounted. On the support frame 53 is provided positioning device P3 for positioning hinge pillar inner 17A of the side inner panel 15 and a pair of upper and lower clamps C5. The left side inner panel 15 is positioned through the devices P1 through P3 and fixed by means of the clamps C2 through C5. As for the RH retainer, between the right and left stationary parts are disposed a pair of vertical columns 54. support frame 55 is disposed between the upper portions of the vertical columns 54. At a pair of front arms 55a of the support frame 55 is provided positioning device P4 and clamp C6 for positioning and fixing the both end portions of the front header 22 respectively. At rear end of biforked arm portions 55b of the support frame 55 are provided positioning device P5 and clamp C7 for positioning and fixing transverse end portions of the rear header 23. Front header 22 is positioned and fixed to the pallet P through the pair of positioning device P5 and clamp C6 whereas the rear header 23 is positioned and fixed to the pallet P through positioning device P6 and claim C7. There is provided positioning device P6 and clamp C8 at both ends of a pair of arm portions 55c provided at middle portion of the support frame 55 for positioning and fixing opposite end portions of roof bow 24. As shown Figure 24, the clamps C1 through C8 are constituted by toggle clamps including crank like clamp lever 56, air cylinder 57 for driving clamp lever 56. The positioning devices P1 through P6 are conventionally known and provided with air cylinder 59 for driving positioning pin 58 for reciprocating movement. As shown in Figure 24, the SP retainer inserts the clamp 45 of the clamp C5 through opening 15a of the side inner panel 15 and clamp the side inner panel 15. The clamps C2 through C4 and positioning device P1 and P2 are transferred to assembling station as shown by real line in Figure 23 through the support plate 48 and the support frame 49 and the clamp C5 and positioning device P3 are transferred to assembling station through the vertical column 52 and movable plate 51 when body member is assembled with the fixture JU. After the upper body structure is assembled, the clamps C2 through C4 and positioning device P1 and P2, the clamp C3 and positioning device P3 are moved to a retracted position as shown by phantom lines so as to retract the fixture JU from the opening 1c (see Figure 24). In this case, the front floor is not mounted yet. In the body assembling line BUL, as shown in Figures 20 and 25, the rear body 12 is assembled in first sub-line SL1. The side panel 15 includes inner panel body, roof rail inner, impact bracket, wheel house and suspension reinforcement and is assembled in second sub-line SL2. The front and rear headers 22 and 23 as roof inner member of the roof panel include header inner panels and header outer panels respectively and is assembled in third sub-line SL3. The side outer panel 14 includes outer panel body, front hinge reinforcement, rear hinge reinforcement, center pillar reinforcement, rear striker reinforcement and corner plate and is assembled in fourth sub-line SL4. The roof panel 13 includes outer panel body and roof bow 24 and is assembled in fifth sub-line SL5. Bonnet 25 and trunk lid 26 are assembled in separate sub-lines (not shown). Four side doors 27 includes door inner panel, door outer panel and sash and is assembled in sixth sub-line SL6. Next, there is described assembling process for the upper body shell BU taking reference with Figures 20, 25 through 28. The upper body shell BU is assembled in a manner that body members are mounted on the fixture JU as the fixture JU is transferred around stations S1 through S9 of the body assembling line BUL. In first station S1, as shown in Figure 25, the rear body 12 is supplied from the first sub-line SL1 and fixed to the fixture which is transferred from the fixture storing station ST and positioned. In this case, the rear body 12 is positioned and fixed to the fixture JU through the four positioning pins 46 and four clamps C1 as shown in Figure 21. In second station, as shown in Figure 25, the right and left side panels 15 are supplied from the first station S1 and fixed to the fixture JU which is positioned there. In this case, the right and left side inner panel 15 are positioned and fixed to the fixture JU by means of the positioning devices P1 through P3 and clamps C2 through C5. There is provided a conveyer 60 for conveying the side panel 15 to the second station S2. As shown in Figure 27, across a downstream and upper end of the second supply line SL2 and upper portion of the second station is diposed a guide rail (not shown) which supports a pair of right and left vertical frames 61 for up and down movement. The frames 61 supports lift arm 62 as a cantilever for up and down movement, which is driven by a lift drive mechanism which is provided close to the upper end of the vertical frame. Beside the lift arm 62 is a guide rail 63 which bears a base plate 64 which is moved tranversely by means of cylinder 65. On the base plate 64 is disposed upright cylinder 66 which includes a movable plate 67 at lower end of the piston rod 66a. The movable plate 67 is provided with support arm 68 and stopper arm 69 which can be inserted from door opening of the side inner panel 15 which is held by the support arm 68 and the stopper arm 69. In the third station S3, as shown in Figure 25, the front and rear header 22 and 23 from the third sub line SL3 are positioned and fixed to the fixture JU. In this case, the header 22 and 23 are positoned by the positioning devices P4 and P5 and clamps C6 and C7. Thereafter, opposite ends of the headers 22 and 23 are joined with the right and left inner panels 15 by tack weld utilizing welding robot 70 disposed in the third station S3. The side inner panels 15 are joined with the rear body 12 by tack weld. In the fourth station S4, as shown in Figure 25, aditional welding is applied on joint portions of the side inner panel 15, rear body 12 and headers 22 and 23 by two welding robots 71. In the fifth station S5, as shown in Figure 26, right and left side outer panels 14 from the fourth subline SL4 are supplied, poisitioned and fixed to the right and left side inner panels 15 which are already fixed to the fixture JU. In the sixth station S6, as shown in Figure 26, roof panel 13 from the fifth subline SL5 is supplied, positioned and fixed to the fixture JU. As shown in Figure 22, roof panel 13 is positioned and fixed by means of the positioning device P6 and clamp C8. Thereafter, the side outer panel 14 is welded to the side inner panel 15 by tack weld and the roof panel 13 is welded to the front and rear headers 22 and 23, side outer panel 14 by tack weld. In seventh station S7, as shown in Figure 26, body members welded by tack weld in the sixth station S6 is welded additionally by two welding robots 73. In eighth station S8, as shown in Figures 26, 28, front and rear side doors 27 are supplied by a pair of robots 75 from the sixth subline SL6 in order and provisionally joined with the side outer panel 14 through a pair of upper and lower hinge members 76 by means of nut runner of fastener 78. The door supply robot 75 is well known type of multiple joint robot which includes a hand 75a having a frame 81 for receiving a pair of toggle clamp devices 80. Clamp lever 80a of the clamp 80 is inserted through window opening to hold door sash. In nineth station, as shown in Figures 20 and 29, upper body structure is lifted by the lift 82 and the fixture JU is moved downwardly relative to the upper body structure BU and removed. Then, the fixture JU is transferred to store station ST and the upper body structure is transferred to transfer station of application line. As for the lift 82, as shown in Figure 29, vertical columns 83 stand with a certain distance in conveying direction. Lift arm 84 is supported by the columns 83. Support frame 85 is provided at tip end of the lift arm 84. A guide rail 86 is provided between the front and rear support frames 85. The guide rail is driven by actuator 87. A base plate 88 is movably suspended by the guide rail 86. Four support arms 89 are swinging supported by four corner portions of the base plate 88. The arm 89 is swung by cylinder 90 which is mounted on arm portion of the arm 85 between engaging position shown by one point chain line in Figure 29 and retracted position shown by double point chain line. The upper body shell BU is transferred from the ninth station S9 to the transfer station as the upper body shell BU is lifted. As shown in Figure 32, at the transfer station, the upper body shell BU is lowered and positioned onto application fixture 91. A modified assembling line BUL will be explained hereinafter. As shown in Figure 30, there is provided sub-line SL 20 from where right and left side panel 11 are supplied to second station S20. Then, the right and left body side panel 11 is transferred from the first station S1 to second station S2A and positioned and fixed to the fixture JU. Next, in the second sub-line SL21, roof panel assembly 13A which is formed by sub-assembling the front and rear headers 22 and 23 with roof panel 13 is supplied, positioned and fixed to the fixture JU. Then the body member is joined by the tack weld. The body member is transferred to the eighth station S8 after making additional welding on the body member. Application process will be explained in reference with Figures 31-36. In the application process, the upper body shell BU, front fender 28, bonnet 25 are mounted on application fixture 91. On the upper body shell are temporarily mounted side door and trunk lid 26. Under body portion BD and front body portion BF are also subjected to application process. As shown in Figures 32, 33, there is provided movable rectangular base frames 93 having four wheels. A pair of retainers 94 is provided for holding the rear frame 21 of upper body shell BU at rear portion of the base frame 93. Another pair of retainers 94 are provided at middle portion of the base frame 93 in the longitudinal direction thereof for holding rear frame 21 of the upper body shell BU. As shown in Figure 34, the transverse fastening pin 96 mounted on the support bracket 95 is moved outwardly to be engaged with positioning opening (not shown) of the rear frame or the closed cross structure 6B at the outer end. Then, the lever 97 is engaged with engaging member 98 to fix the body shell BU to the base plate 93. In order to fix front fender 28 and bonnet 25 to the base frame 93, pins 100 of support frame is inserted into three bolt openings of front fender 28 and bonnet hinge 25a of the bonnet 25 is fixed to a pair of blocks 101 of the frame 99 provisionally. Referring to Figure 31, application process will be explained. On application fixture 91 are mounted four side doors, upper body shell, bonnet and front fender 28 which are hung by 102 together with the fixture 91 and are transferred to stations of application line. In formation treatment process, the upper body shell BU and the body member is subjected to degreasing treatment, forming zinc phosphate base coating by continuous spraying and rinsing. In base coating process, upper body shell BU and the body member with the fixture 91 are dipped into coating bath of epoxy resin for electro-coating wherein electro-coating is made on the body member as a cathode with 200-400V, thereafter, rinsing and drying with 170 centigrade for 25 minutes. In undercoating process, anti-chipping compound such as urethane or PVC base compound are sprayed on lower outer surface of the upper body shell BU, side door 27 and rear portion of front fender 28 and dried to form under-coating of 100-200 µm. In inter-coating process, the upper body shell BU, body member are grounded and subjected to electrostatic-coating by charging epoxy ester base coating compound with -60 from -90kV. Thereafter, the solvent is vaporized for 5 to 10 minutes. In drying process, the upper body shell BU and the body member are dried at 140 to 150 degree centigrade for 25 minutes. In over coating process, the upper body shell BU, body member are grounded and subjected to electrostatic-coating by charging melamine-alkyd resin, or acrylic resin base paint with -60 from -90kV. Thereafter, the solvent is vaporized for 5 to 10 minutes. In drying process, the upper body shell BU and the body member are dried at 140 to 150 degree centigrade for 25 minutes. Thus, in the formation treatment process to the over coating process, the side door 27, upper body shell BU, front fender 28 and bonnet 25 are mounted on the single fixture 91 and treated together so that uniform coating in color can be obtained. The line for the application can be simplified and thus not costly as well. In addition, the number of the hanger 102 can be reduced so that deposition of the electro -coating material can be reduced and thus the consumption of the coating material can be reduced. Light lid and garnish may be attached to the fixture 91 by means of support frame 99 to be coated together with the body member and the upper body shell BU. Prior to the application of the underbody portion BD, the underbody portion BD is subjected to application of sealing material and mounting of hole cover and melt sheet. In undercoating process, anti-chipping compound such as urethane or PVC base compound are sprayed on lower surface of the under body shell BD and dried in common drying chamber to the upper body shell BU to form under-coating of 100-200 µm. When the under body portion BD is made of steel, the under body portion and upper body portion can be treated together on the fixture 91 before the inter-coating process. Front body portion BF is treated similar to the upper body shell in the formation treatment, base coating, under coating and drying in the same drying chamber as the upper body shell BU. Thus, efficiency of the drying process can be improved. Running and installation cost can be reduced. As shown in Figure 36, retainer 94A at the front portion of base frame 93A is provided on the fixture 91 instead of the support frame 99 for holding the front body portion BF which is to be treated together with the side door 27, upper body shell BU. After the application process, the upper body shell BU, front fender 28 and bonnet 25 are removed from the fixture 91. Right and left side doors 27 and trunk lid 26 are removed from the upper body shell BU. The body member and both body members BD are transferred to separate equipping lines therefor in the body assembling process. Vehicle Assembling Process There will be described a vehicle assembling process referring to Figures 37 to 46. Main equipping line includes one for the upper body shell BU. As shown in Figure 37, body portions BD and BF and body members such as lid members are supplied to the main line in order to be mounted on the upper body shell BU to assembly the upper body shell BU. As shown in Figure 38, as the upper body shell BU is transferred in the equipping line, screw grommet, fastener, harness, interior unit including top sealing, sun visor, room mirror and the like, rear strut, rear combination lamp, package unit including package trim, speaker, high mount lamp and the like, rear bumper, rear floor mat, rear seat, trunk room unit, rear windshield and the like are equipped on the upper body shell BU by means of equipping robot 115 disposed on truck 110. Transfer truck 114 with own driving mechanism is provided with a plurality of support brackets 116 for positioning and holding the upper body shell BU, robot 115 on the center portion and sub-pallets 117 at the opposite sides of the robot 115. On the sub-pallet 117 are provided a plurality of fit-in parts of a predetermined arrangement. Left side of the robot and outside of the upper body shell BU is disposed tool base 118 on which a plurality of tools to be removably mounted on the robot 115 are arranged in a predetermined order. The robot 115 is of a multiple joint which is commonly known. Control box 119 is provided for controlling the robot 115. As the truck 114 is moved, the control box 119 produces signals for equipping. Thus, the parts is equipped for the upper body shell BU which is separated from the under body portion. In this process, as understood, the robot can be disposed through floor opening 1c. Therefore, the fit-in parts can be equipped for the inside of the upper body shell effectively by disposing the robot 115 in passenger compartment 29. Equipping process can be automated without great difficulty. The equipping process is applied while the upper body shell is conveyed so that time loss can be reduced. The truck 114 can be moved intermittently as well. Alternatively, conveying truck 112 can be provided with rotatable support mechanism for rotatably supporting the upper body shell BU. In this case, top sealing TP and the like are assembled on the upper body shell which is rotated by a certain angle by means of the automatic device 113 disposed beside of the line. As aforementioned, the upper body shell BU is assembled based on inner panel so that assembling accuracy can be improved. The robot 115 is mounted on the truck 114 so that the upper body shell can be accurately positioned against the robot. Thus, the equipping process can be effectively automated. If the robot 115 and/or the truck 114 malfunction, the malfunctioned devices can be removed from the line without stopping the line and without reducing operating efficiency. Teaching and testing for the robot 115 can be made out of the line. This is convenient when a model change of the vehicle is made. In the equipping line for the underbody portion BD, as shown in Figure 40, the underbody portion BD is positioned and fixed to pallet (not shown) and transferred to a plurality of stations in order. Change lever 150, parking brake lever 151, floor mat 152, rear seat belt 153 and rear console 154 as fit-in parts are mounted on the underbody portion BD. Then, small things such as fastener and bolt is mounted on the underbody portion BD by robot (not shown). Next, four seal protectors 156 for covering passenger's feet on front seat 155 are provided. Thus, equipping process is applied on the underbody portion BD on the separate equipping line so that working efficiency can be improved. In the equipping line for the front body portion BF, as shown in Figure 42, the front body portion BF positioned and fixed on the truck 120 is conveyed on the equipping line. Acceleration pedal, brake pedal, wiper motor, dash unit 157 including inner panel assembly, air conditioner unit are mounted on the front body portion BF. The truck 120 is provided with support mechanism 123 which changes attitude of the front body portion BF between the vertical position and the horizontal position. The equipping process is applied on the front body portion BF while changing the attitude of the front body by means of automatic device 122 disposed beside of the line. The dash unit 157 and the like are supplied, positioned on the front body portion BF which is made up side down by supply device 121 and mounted thereon by the automatic device 122. Since attitude of the front body portion BF is switched while equipped with fit-in parts, the equipping efficiency can be improved. In addition, it is not necessary to use devices for holding the parts against the body portion BF prior to the equipping. In equipping lines for lid like members such as the side door 27, front fender 28, bonnet 25 and trunk lid 26, black painting, application of the secondary corrosion protection oil, mounting of molding and rubber are made. Then, fit-in part such as harness, lamp, wind regulator are mounted thereon. Thus, these lid like members which are separated from the upper body shell BU are equipped in the respective equipping lines. The equipping efficiency can be improved. As shown in Figure 42, front body portion BF is moved toward the underbody portion BD rearward and mounted onto underbody portion BD from the front of the underbody portion BD to form integrated lower body shell BL. In this case, the two body portion BD, BF are joined by bolt and nut, adhesive, welding, combination thereof and the like. Next, lower body shell BL is positioned and mounted on movable truck 125 in joint station CS1. Upper body shell BU is hung by hanger 127 and fixed to right and left stationary bases 126 of the joint station CS1. The movable truck 125 is moved rearward under the upper body shell BU and mounted thereon. In this case, opposite side ends of the front floor are moved rearward and engaged with bearing portions 31b of engaging grooves 33 of the side sills 20. The front floor 1 is fixed to the side sill 20 by adhesive applied on the grooves 33. Concurrently, cross sectioned structures 6A and 6B forming the hinge pillar 6 are engaged and joined together by joint robot 128 between the stationary bases 126. Other portions such as rear end of the front floor 1 are also joined by the robot 128. Thus, the lower body shell BL is assembled with the upper body shell BU to form body shell. When the upper body shell includes cowl member 10A, seatback of the front seat 155 is fell down rearward to take a reclined position to avoid interference of the cowl member 10A and upper end portion of the seatback. In a modification of the joining process, as shown in Figures 47 to 49, the underbody portion BD is moved rearward and mounted to the upper body shell BU at first. Then, the front body portion BF is moved rearward and mounted to the integrated structure of the upper body shell BU and the underbody portion BD. Next, the body shell B hung by conveying hanger (not shown) is transferred to a plurality of stations in order wherein lid like members such as side door 27, trunk lid 26 and front windshield glass are positioned and mounted on the body shell B. The process is carried out before lower body unit 160 which is heavy is mounted thereto so that the hanger can be simplified. The lid like members can be mounted easily. In the above process, the front windshield glass is mounted after the joint of the upper body shell and lower body shell so that lower end portion of glass does not interfere with the upper end of the front seat 155. The side door 27 is mounted on the body shell by means of devices similar to the door supply robot 75, joint device 78 which is employed in the body assembling process. In mounting the lower unit 160, as shown in Figure 46, the lower unit 160 including engine 161, transmission (not shown), front and rear suspension 162 and exhaust manifold 163 and fuel tank which is positioned and mounted on pallet 129 is transferred to conveyer 130 of joint station CS2. The body shell B is hung by support arm 131 and transferred to the joint station CS2. Then, the body shell B is lowered to engaged with the lower unit 160 and joined with the lower unit 160 by means of bolt and the like. Next, right and left fenders 28 and bonnet 25 are positioned and mounted on the body shell B. Since the lower unit 160 is mounted on the body shell B before the bonnet 25 is mounted, the lower unit 160 does not interfere with the bonnet 25. Operating efficiency can be improved in mounting the lower unit 160. In the vehicle assembling process, equipment of the upper body shell BU takes about 39 minutes, about 9 minutes for underbody portion BD, about 25 minutes of front body portion BF. Equipment for the upper body shell which takes the longest time is provided as main line. As a result, the body portions BD and BF can be supplied smoothly. Another preferred embodiment will be explained hereinafter. Referring to Figure 50, in the vehicle assembling process, lower body shell BL and upper body shell are assembled in respective assembling lines. Cowl member 10A can be attached to the upper body shell BU as shown in Figure 50. As shown in Figure 51, the main center floor 40 and third cross member 41 can be included in the lower body shell BL. In the application process, the upper body shell BL is treated as well as the former embodiment. The lower body shell BL is subjected to application treatment after necessary treatment in separate application line. Thereafter, the lower body is dried in the same drying chamber as that for the upper body shell BU after inter and over coating. In vehicle assembling process, as shown in Figure 52, fit-in parts are mounted on the upper body shell BU as well as the former embodiment. Fit-in parts are also mounted on the lower body shell BL as well as under body portion BD and front body portion BF in the former embodiment. As shown in Figures 43 to 45, the lower body shell BL is moved rearward and mounted on the upper body shell BU and join together. In another embodiment of joint structure of the upper body shell BU and underbody portion BD: As shown in Figure 53, side sill 20H of steel includes cross sectioned inner side sill portion 20a formed on opposite side ends of the front floor 1A, cross sectioned outer side sill portion 20b integrated into the lower end of the body side panel of the upper body shell BU. A bearing portion 35J extended horizontally is formed on the inner and lower end portion of the outer side sill portion 20b. The under body portion BD is moved rearward to the upper body shell so that right and left ends portion of the under body portion BD are engaged with the bearing portions to be supported. Then, inner side sill portion 20a is fixed to the outer side sill portion 20b by means of adhesive. This structure enables the contact area thereof to be expanded to obtain enhanced joint strength. Alternatively, as shown in Figure 54, side sill 20I includes cross sectioned inner side sill portion 20c of aluminum or aluminum alloy which is integrated with opposite ends of the front floor 1 having honeycomb base 1a and upper and lower reinforcing plates 1b, cross sectioned outer side sill portion 20d integrated with the lower end of the body side panel of the upper body shell BU. The outer side sill portion 20d is formed at inner and lower end thereof with bearing portion 35K extending horizontally. As the under body portion BD is moved rearward relative to the upper body shell BU, right and left bearing portions 35K are engaged to support right and left of the under body portion BD so that the inner side sill portion 20c is fixed to the outer side sill portion 20 by means of adhesive. The same effect as the former embodiment can be obtained. Referring to Figures 54-56, there is shown another embodiment of the vehicle body structure in accordance with present invention. The floor member 1 is formed with first horizontal portion 172 on which the front seat is mounted, upright portion 173 extending upwardly from the rear end of the horizontal portion 172, second horizontal portion 174 extending from the upper end portion of the upright portion 173 on which the rear seat is mounted. The first and second horizontal portions 173 and 174 are of honeycomb structures. The upright portion 173 is made of thin plate. The upper body shell BU is provided with side sill 20 which is formed with first groove 175 for receiving opposite side end portions of the first horizontal portion 172, and horizontal portion 176 extending inward of passenger compartment. The horizontal portion 176 is formed with first groove 177 at the front end portion thereof for slidably receiving opposite ends of the second horizontal portion 174. When the lower body shell BL is moved rearward to the upper body shell BU to assemble them together, the opposite side end portions of the first horizontal portion is inserted to the groove 175 to be engaged and the second horizontal portion 174 is inserted into the second groove 177 to be engaged. The rearward movement of the floor 1 of the lower body shell BL is guided by the two grooves 175 and 177. Referring to Figures 57 to 67, there are shown further joint structures of side sill 20 and floor panel 1. The floor member 1 is formed with groove 181 extending longitudinally on the lower surface thereof. The side sill 20 is formed with extension 183 having hook 182 which is brought into slidable engagement with the groove 181 so that the rearward movement of the lower body shell BL is guided and the lower body shell BL is supported when the insertion is finished. Opposite side ends of the floor member 21 is inserted into the groove 184. Brackets 185 and 186 are provided on the upper surface of the floor member 1 for mounting the cross member and seat belt. The brackets 185 and 186 are formed with T-shaped hook portion 186a at opposite ends. The side sill 20 is formed with groove 187 with which the hook portion 186a is slidably engaged. When the lower body shell BL is moved rearward and engaged with the upper body shell BU, the hook portion 186a is brought into engagement with the groove 187. If the front floor 1 is of honeycomb structure, it is difficult to form the groove 181 of the front floor 1. In this case, aluminum member 188b formed with the groove 181 is attached to opposite side ends of the front floor 1 of honey comb structure. As shown in Figure 59, the front floor 1 is formed with engaging portion 191 which is greater than the front floor 1 in thickness. The side sill 20 is formed at inner surface with groove 192 for engaging with the engaging portion 191. Prior to joining the lower and upper body shells BL and BU, adhesive 193 is supplied to the groove 192 as shown in Figure 59 (a). Then, engaging portion 191 of the front floor 1 is inserted rearward into the groove 192 of the side sill 20. When inserted, the adhesive 193 is intervened between the groove 192 and the engaging portion 191 to fix them. Referring to Figure 60, there is shown another joint structure between the front floor 1 and side sill 20. The side end portion of the front floor 1 is formed with thick portion 201 extending downward, which is engaged with groove 202 of the side sill 20. Prior to insertion of the front floor 1, adhesive 204 with beads 203 is applied on bottom surface of the groove 202. As the front floor 1 is moved rearward, the thick portion 201 is brought into rolling engagement with the groove 202. Assembling force can be reduced. Referring to Figure 61, side sill 20 is formed with groove 211 which slidably receives the side end 1a of the front floor 1. Prior to insertion of front floor 1, thermoplastic adhesive is applied on inner surface of the groove 211 as shown in Figure 61 (a). Then, the front floor 1 is engaged with the front end of the side sill 20 and moved rearward in a manner that the side end of the front floor 1 is engaged with the groove 211. After full engagement between the side end 1a and groove 211, steam 214 is introduced into inner surface 212 of channel like configuration formed surrounding the groove 211 to harden the adhesive 213 to fix the floor 1 and side sill 20. Referring to Figure 62, after adhesive 222 is applied on groove 221 of the side sill 20, the front floor 1 is moved rearward with extension 223 being engaged with groove 221. In this case, the front floor 1 is formed with projection 224 engaged with groove 225 of support member 226 which supports the front floor 1 as it is moved rearward. According to this embodiment, positioning of the front floor 1 can be easily accomplished. Referring to Figure 63, the side sill 20 is provided with groove 231 for receiving side end 1a and swinging cover member 232 which can swing around the upper end thereof. Prior to the insertion of the front floor 1, adhesive 233 is applied on the side end of the front floor 1. Then, the cover member 232 is swung away from the inner surface of the side sill. The front floor 1 is moved rearward with the side end being engaged with the groove 231. Next, the cover member 232 is swung toward the inner surface of the side sill 20 to contact with it as the cover member 232 introduces the adhesive into space between the side sill 20 and side end of the front floor 1 as shown in Figure 63 (b). As a result, hook portion 232a of the tip end of the cover member 232 is fixed to the floor 1. Referring to Figure 65, the side sill 20 is formed with groove 241. In this embodiment, adhesive of urethane foam 243 is introduced into the groove 241 through the passage 242 to fix the front floor 1 with the side sill 20 after the insertion of the front floor 1. Thus, the front floor 1 is not subjected to resistance of the adhesive when inserted. This ensures the introduction of the adhesive between the front floor 1 and the side sill 20. When the front floor 1 is of honeycomb structure, it is desirable to form air bent on the floor 1. Referring to Figure 65, the front floor 1 is formed with a side frame portion 251 extending upwardly, which forms a groove 252 extending along the side sill 20. The side sill 20 is formed with projected structure 253 which is brought into slidable engagement with the front floor 1 through the groove 252. In this structure, the brackets 185 and 185 can be fixed to the side frame portion 251. Referring to Figure 66, the side sill 20 is formed with first groove 261 opened downwardly at bottom outer surface and second groove 262 opened outward at side outer surface, which are extended longitudinally. The front floor 1 is formed with first extension 263, which extends upwardly, for slidably engaging with the first groove 261 and extended portion 264, which extends along the outer surface of the side sill 20. The extended portion 264 is formed with second extension 265 for slidably engaging with the second groove 262. When the front floor is inserted, adhesive 166 is applied on surfaces of grooves 261 and 262 as shown in Figure 66(a). Then the front floor 1 is inserted and moved rearward with the grooves 261 and 262 being engaged with the extensions 263 and 264 as shown in Figure 66(b). In this structure, the outer side of the front floor 1 forms a lower portion of the side sill to provide fresh appearance. Referring to Figure 67, the front floor 1 is formed with lower side sill portion 271, which extends upward, at the side end. The lower side sill portion 271 is formed with a groove 272, which extends longitudinally, at the top end thereof. The side sill 20 is formed with extension 273, which is brought into slidable engagement with the groove 272, at the lower end. In assembling the body shells, the front floor is moved rearward with the extension 273 being engaged with the groove 272. In this embodiment, the lower side sill portion 271 of the front floor forms a lower part of the side sill 20. In this case, the bracket 186 for mounting the seat belt can be mounted onto the lower body shell BL before the floor 1 is inserted into the side sill 20 of the upper body shell BU. Although the present invention has been explained with reference to a specific, preferred embodiment, one of ordinary skill in the art will recognize that modifications and improvements can be made while remaining within the scope of the present invention. The scope of the present invention is determined solely by the appended claims.

Claims: A vehicle assembling method comprising steps of assembling lower body shell (BL) including underbody portion (BD) having a front floor (1) and front body portion (BF), assembling upper body shell (BU) including roof member (13), right and left body side panels (11), and assembling the upper body shell (BU) and the lower body shell (BL), moving rearward the lower body shell (BL) relative to the upper body shell (BU), engaging transverse opposite side ends of the lower body shell (BL) with lower end portions of the upper body shell (BU) to join the lower body shell with the upper body shell. A method as recited in claim 1 wherein the lower body shell is formed with extensions (1) at the opposite end portions, the upper body shell is formed at the lower portions with grooves (33) engaged with the extensions. A method as recited in claim 1 wherein the lower body shell (BL) is formed with grooves at the opposite end portions, the upper body shell is formed at the lower portions with extensions engaged with the gooves, and the groove and extension facilitates relative movement of the upper body shell and lower body shell. A method as recited in claim 2 or 3 wherein adhesive is applied on a surface of the groove prior to the engagement of the lower body shell (BL) and the upper body shell (BU). A method as recited in claim 1 further comprising steps of forming bearing portion (31) on right and left side sills (20) of the upper body shell for bearing right and left ends of the front floor (1), conveying the upper body shell and lower body shell to equipping lines and equipping the upper and lower body shells respectively, moving under body portion (BD) of the lower body shell rearward relative to the upper body shell to engage transverse opposite side ends of the front floor with the bearing portions (31) of the right and left side sills (20) and joining the lower body shell with the upper body shell. A method as recited in claim 1 wherein the lower body shell (BL) including the under body portion (BD) and front body portion (BF) integrated with the under body portion (BD) is equipped with parts, thereafter, the lower body shell is joined with the upper body shell. A method as recited in claim 1 wherein the under body portion (BD) and the front body portion (BF) which is not joined with the front body portion are equipped with parts respectively, thereafter, the both body portions are joined with the upper body shell. A method as recited in claim 1 wherein the under body portion (BD) and the front body portion (BF) which is not joined with the under body portion are equipped with parts separately, thereafter, the front body portion is joined with the upper body shell and the under body portion. A method as recited in claim 1 wherein one of the upper body shell, the under body portion and the front body portion, on which the most burdensome equipping process is needed, is supplied to a main equipping line (BUL). A method as recited in claim 1 wherein the right and left ends of the front floor are joined with at least the right and left bearing portions (31) of the side sills (20). A method as recited in claim 1 further comprising steps of forming bearing portion (31) on right and left side sills (20) of the upper body shell (BU) for bearing right and left ends of the under body portion, conveying the upper body shell and lower body shell to equipping lines and equipping the upper and lower body shells respectively, moving the under body portion rearward in longitudinal direction of the vehicle relative to the upper body shell to engage the right and left ends of the under body portion with the right and left bearing portions of the upper body shell and joining the right and left ends of the underbody portion with the right and left lower ends of the upper body shell. A method as recited in claim 1 further comprising steps of forming bearing portion (31, 35a) on right and left side sills (20, 20a) of the upper body shell for bearing right and left ends of the front floor, moving under body portion of the lower body shell rearward relative to the upper body shell to engage transverse opposite side ends of the front floor with the bearing portions (31, 35a) of the right and left side sills (20, 20a) and joining the lower body shell with the upper body shell. A method as recited in claim 12 wherein the upper body shell and the under body shell including the under body portion and the front body portion are assembled in separate lines. A method as recited in claim 12 wherein the upper body shell (BU), the under body portion (BD) and the front body portion (BF) are assembled in separate lines, the under and front body portions are joined with the upper body shell after the underbody portion is joined with the front body portion. A method as recited in claim 12 wherein the upper body shell (BU), the under body portion (BD) and the front body portion (BF) are assembled in separate lines, the front body portion is joined with the upper body shell and the underbody portion after the underbody portion is joined with the upper body shell. A method as recited in claim 12 wherein the upper body shell are assembled in separate lines, then, the both body shells are subjected to application treatment, thereafter, the both body shells are equipped with fit-in parts and joined with each other. A method as recited in claim 12 wherein the upper body shell, the under body portion and the front body portion are assembled together, then subjected to application treatment, equipped with fit-in parts and fixed together. A vehicle body structure comprising lower body shell (BL) including floor member (1), upper body shell (BU) including roof member (13) and right and left body side panels (11), transverse opposite side end portions of the lower body shell being engaged with the lower end portions of the body side panels of the upper body shell by moving rearward the lower body shell relative to the upper body shell and inserting the lower body shell (BL) into the upper body shell (BU), the opposite side end portion having a complemental configuration to the lower end portion so that the relative movement of the lower body shell to the upper body shell is facilitated after engagement of the opposite side end portion and the lower end portion. A vehicle body structure as recited in claim 18 wherein engaging portion (1, 33, 35a) of the lower end portion is formed at inner surface of the body side panel. A vehicle body structure as recited in claim 18 wherein engaging portion (1, 33, 35a) of the lower end portion is formed at outer side of the body side panel, and engaging portion (1, 33, 35a) of the side end portion extends surrounding a part of the outer surface of the body side panel.

Inventors: INOUE HIROAKI, KATSUKI HISAAKI, KIHARA NOBUO, KOGAI MASAMITI, MURAKAMI TETSUYA, NISHIMOTO SYUJI, OHSUGI MASAKATSU, OSUMI MASAHIRO, INOUE, HIROAKI, KATSUKI, HISAAKI, KIHARA, NOBUO, KOGAI, MASAMITI, MURAKAMI, TETSUYA, NISHIMOTO, SYUJI, OHSUGI, MASAKATSU, OSUMI, MASAHIRO
Applicants: MAZDA MOTOR, MAZDA MOTOR CORPORATION
Application year: 1992
Main classification: B62D65
IPC codes: B62D65