Vehicle manufacturing method and vehicle

Abstract

This vehicle manufacturing method involves: preparing, on each of a plurality of sub-lines, a sub-module (20) including a structural member of a vehicle body; and coupling, on a main line, the plurality of sub-modules (20) to a center frame (10) in order to construct the vehicle body. The center frame (10) is formed by coupling together a pair of center side members (12) extending in a vehicle front-rear direction and a pair of center cross members (14, 16) extending in a vehicle width direction to form a rectangular shape.

Description

Method for manufacturing vehicle and vehicle

[0001] The present specification discloses a method for manufacturing a vehicle, and a vehicle.

[0002] As is well known, a vehicle is configured by combining a large number of components. In order to simplify the manufacturing process of such a vehicle, a technique has been proposed in which the vehicle is divided into a plurality of parts, each part is modularized, and the plurality of modules are sequentially joined together.

[0003] For example, Patent Document 1 discloses a method for manufacturing a two-wheeled vehicle. In the method disclosed in Patent Document 1, a front fork module, a front frame module, an engine module, and a rear frame module are individually assembled in advance. Then, on a joining module line, the individually assembled modules (hereinafter referred to as "individual modules") are sequentially coupled to constitute a joined module.

[0004] Japanese Unexamined Patent Application Publication No. 11-240475

[0005] However, in Patent Document 1, individual modules are sequentially coupled to other individual modules on the joining module line. In such a configuration, positioning between individual modules and handling on the manufacturing line are difficult.

[0006] For example, consider a case where a second individual module is coupled to a first individual module, and then a third individual module is coupled to the second individual module. In this case, positioning errors of each of the first individual module, the second individual module, and the third individual module are superimposed and exist between the first individual module and the third individual module. In order to reduce such superimposed positioning errors, various adjustments are required in the coupling of each individual module, which complicates the manufacturing process.

[0007] Furthermore, in the example described above, when assembling the third individual module into the second individual module, the first individual module is already assembled into the second individual module. In this case, even if one attempts to change the position and orientation of the second and third individual modules for assembly, the first individual module may get in the way, making it difficult to easily change their position and orientation.

[0008] Therefore, this specification discloses a vehicle manufacturing method and a vehicle that can simplify the manufacturing process.

[0009] A method for manufacturing a vehicle disclosed herein is a method of preparing partial modules including structural members of the vehicle body in each of a plurality of sublines, and connecting the plurality of the partial modules to a center frame in a mainline in order to construct the vehicle body, wherein the center frame is constructed by connecting a pair of center side members extending in the longitudinal direction of the vehicle and a pair of center cross members extending in the width direction of the vehicle in a rectangular shape.

[0010] By configuring partial modules in the sub-line beforehand, the handling of parts in the main line becomes easier. Furthermore, by connecting the partial modules to the center frame, the center frame becomes the reference point for positioning, making the positioning work of the partial modules easier.

[0011] In this case, when the center frame is fed into the main line, the area inside the roughly rectangular space enclosed by the pair of center side members may be an open space into which an operator can enter.

[0012] This configuration allows the empty space inside the center frame to be used as a workspace on the main line. As a result, work can be done from various directions on the vehicle, improving work efficiency.

[0013] Furthermore, the plurality of sub-modules may include end modules that constitute the front or rear of the vehicle body, and the end modules may include a cast part in which a pair of left and right end side members are integrally cast, and element parts assembled to the cast part.

[0014] By integrally casting the left and right side members, the number of parts can be reduced. Large parts such as cast parts are prone to distortion, but by positioning the cast part relative to the center frame, alignment in subsequent processes becomes easier. In addition, by configuring the system so that elemental parts are assembled to the cast part before it is attached to the center frame, the work efficiency of assembling the elemental parts is improved.

[0015] Furthermore, the end module includes a front end module that constitutes the front part of the vehicle body, and the element component includes a sub-module which is a modularized component comprising a skeletal member coupled to the cast component and an on-board component assembled to the skeletal member, and the on-board component may include at least one of a thermal management unit, an air conditioning component, an ECU, and a pedal.

[0016] By further configuring the multiple components to be assembled into a cast part as small modules, the manufacturing of the front end module can be simplified.

[0017] Furthermore, the partial module may include a side module that constitutes the side of the vehicle body, and the side module may include a rocker extending in the longitudinal direction of the vehicle, and the side module may be coupled to the center frame in the main line such that the rocker is aligned with the center side member in the vehicle width direction.

[0018] This configuration allows the center side member and the rocker to be aligned in the width direction of the vehicle, making it easy to construct a vehicle body with high side impact resistance.

[0019] Furthermore, the partial module may further include a front end module that constitutes the front of the vehicle body, and in the main line, after the front end module is coupled to the center frame, and before the side modules are coupled to the center frame, an instrument panel module may be coupled to the front end module.

[0020] By assembling the modules in this order, the side modules do not get in the way during the transport and assembly of the front end module and instrument panel module. As a result, the work efficiency when assembling the front end module and instrument panel module is improved.

[0021] Furthermore, the partial module includes a front end module that constitutes the front of the vehicle, a rear end module that constitutes the rear of the vehicle, a side module that constitutes the side of the vehicle, and a battery module that constitutes the bottom of the vehicle. In the main line, at least one of the front end module, the rear end module, and the side module may be coupled to the center frame, and then the battery module may be coupled to the center frame.

[0022] By connecting the modules in this order, the space inside the center frame can be used as a workspace when connecting modules other than the battery module.

[0023] Furthermore, the battery module may include a battery, a seat cross member connecting the pair of center side members above the battery, and a front seat positioned on the seat cross member.

[0024] This configuration allows the battery, seat cross member, and front seat to be treated as a single component on the main line, improving work efficiency. Furthermore, by pre-assembling the seat cross member and front seat to the battery before connecting it to the vehicle, the amount of work that needs to be done in the confined space of the vehicle is reduced, further improving work efficiency.

[0025] Furthermore, vehicles in the process of being manufactured on the main line may be transported while suspended in the air, and the battery module may be transported from the underside of the vehicle toward the center frame by a hand of an articulated robot.

[0026] By using a multi-joint robot, the battery modules can be positioned closer to the factory floor before assembly, compared to using a lifter. Therefore, even if the vehicle's suspension height is kept low, interference between the front seat and the center frame can be prevented.

[0027] Furthermore, the partial module includes a front end module that constitutes the front of the vehicle body and a rear end module that constitutes the rear of the vehicle body. In the main line, the front end module and the rear end module may be connected to the center frame, and then a wide-area component, which is an on-board component that spans from the front to the rear of the vehicle body, may be arranged via the center frame.

[0028] By positioning some of the wide-area components on the center frame, loosening and entanglement of these components during the work process are effectively prevented, improving work efficiency.

[0029] Furthermore, the wide-area component may be pre-configured as a single component, and in the main line, the wide-area component may be assembled to the center frame as a single component connected from the start end to the end end.

[0030] By treating a wide range of components as a single part without dividing them into multiple parts, the need for connecting parts is eliminated, improving work efficiency. Furthermore, since connectors necessary for connecting parts are also eliminated, costs can be reduced.

[0031] In this case, the wide-area component may be a wire harness.

[0032] By arranging the wire harness as a wide-area component, the assembly of the wire harness becomes easier.

[0033] Furthermore, the sub-module may further include a battery module, which includes a battery located under the floor of the vehicle, and the extensive components may be positioned in the main line before the battery module is coupled to the center frame.

[0034] By arranging the components in this order, the space inside the center frame can be used as a workspace when arranging a wide range of parts, improving work efficiency.

[0035] Furthermore, the partial module includes a front end module that constitutes the front of the vehicle, a rear end module that constitutes the rear of the vehicle, a side module that constitutes the side of the vehicle, and a battery module that constitutes the bottom of the vehicle. In the main line, the front end module and the rear end module may be coupled to the center frame, then the side module may be coupled to the center frame, the front end module, and the rear end module, and then the battery module may be coupled to the center frame.

[0036] By following this sequence, the internal space of the center frame can be used as a workspace when joining the end modules and side modules. Furthermore, since there are no members separating the inside and outside of the vehicle before the side modules are joined, the joining of large components (such as end modules and instrument panel modules) can be performed efficiently.

[0037] Furthermore, the sub-module may further include a battery module that includes a battery located under the floor of the vehicle, and in the main line, some of the extensive components may be located on the upper surface of the center frame, and the battery module may be coupled to the lower surface of the center frame.

[0038] This configuration allows the center frame to function as a holder for a wide range of components, as well as a holder for the battery module. This reduces the overall number of parts in the vehicle.

[0039] The vehicle disclosed herein is characterized by comprising a center frame formed by connecting a pair of left and right center side members and a pair of front and rear center cross members to each other in a rectangular shape, and a plurality of partial modules, each including a structural member of the vehicle body, and a plurality of partial modules connected to the center frame.

[0040] This configuration allows multiple sub-modules to be positioned relative to the center frame, making it easier to align them with one another.

[0041] In this case, the plurality of partial modules may include a front end module constituting a front portion of the vehicle and a rear end module constituting a rear portion of the vehicle body, and may further have a wide-range component that spans from the front end module to the rear end module via the center frame.

[0042] By disposing a part of the wide-range component on the center frame, slack and entanglement of the wide-range component are effectively prevented during work processes, and workability is improved.

[0043] According to the technology disclosed in the present specification, the manufacturing process of a vehicle can be further simplified.

[0044] This is a flowchart showing the first half of the vehicle manufacturing flow. This is a flowchart showing the second half of the vehicle manufacturing flow. This is an exploded perspective view of the center frame. This is an exploded perspective view of the front end module. This is a perspective view of the rear end module. This is a perspective view showing a state in which two end modules are coupled to the center frame. This is a schematic side view of the front end module. This is a perspective view showing a state in which side modules are coupled to the center frame. This is a schematic diagram showing a state in which a battery module and a powertrain module are attached to the vehicle body. This is a diagram showing a state in which a Fr absorption module is coupled to the front end module, and is a schematic plan view. This is a diagram showing a technique of a comparative example for attaching a battery module.

[0045] Hereinafter, a vehicle and a method for manufacturing the vehicle will be described with reference to the drawings. FIGS. 1 and 2 are flowcharts showing the flow of vehicle manufacturing. Here, in the present specification, a four-wheeled passenger car having a front seat and a rear seat will be described as an example. However, the configuration of the vehicle described below is an example, and may be modified as appropriate.

[0046] The vehicle manufacturing process is broadly divided into processes performed on multiple sub-lines (S10, S12) and processes performed on the main line (S14-S32). The multiple sub-lines include a sub-line for manufacturing the center frame 10 (S10) and a sub-line for manufacturing the partial modules 20 (S12). The center frame 10 is a rectangular skeletal member located in the lower center of the vehicle, as will be explained in detail later. On the main line, multiple partial modules 20 are joined to this center frame 10, which will be described later.

[0047] A partial module 20 is a module that constitutes a part of a vehicle and is composed of multiple parts. The configuration of such a partial module 20 differs depending on its location in the vehicle. For example, as will be explained in detail later, the front end module 22f located at the front of the vehicle, the rear end module 22r located at the rear, the side modules 66 located on the sides, and the battery module 82 located at the bottom all function as partial modules 20. In Figure 1, only one block for manufacturing partial modules 20 is shown. However, in reality, there are multiple sub-lines for manufacturing partial modules 20, depending on the number of types of partial modules 20. Furthermore, these multiple sub-lines operate independently of each other. The center frame 10 and partial modules 20 manufactured on the sub-lines are sequentially fed into the main line.

[0048] FIG. 3 is an exploded perspective view of the center frame 10. Note that Fr, Up, and Rh in the following respective drawings respectively indicate the front, upper, and right sides of the vehicle. The center frame 10 is configured by fastening a pair of center side members 12, a front center cross member 14, and a rear center cross member 16 to each other with bolts. The center side members 12 are frame members elongated in the vehicle front-rear direction. The front center cross member 14 is a frame member that connects the front ends of the pair of center side members 12. The rear center cross member 16 is a frame member that connects the rear ends of the pair of center side members 12. The members 12, 14, 16 constituting such a center frame 10 are manufactured, for example, by extruding aluminum. The center frame 10 is configured by combining these four members 12, 14, 16. In other words, the center frame 10 does not have any other cross member between the front center cross member 14 and the rear center cross member 16. Therefore, a hollow empty space 18 exists inside the center frame 10.

[0049] In the main line, a front end module 22f and a rear end module 22r (hereinafter referred to as "end modules 22" when the two are not distinguished) are coupled to this center frame 10 (S14). FIG. 4 is an exploded perspective view of the front end module 22f. The front end module 22f includes a Fr cast component 28f and a plurality of element components 40 coupled to the Fr cast component 28f. The Fr cast component 28f is manufactured by integrally casting a plurality of structural members disposed at the front portion of the vehicle. For example, the Fr cast component 28f has a substantially bilaterally symmetrical shape. Each of the right half and the left half of the Fr cast component 28f has a wheel house 30, a Fr side member 32 (functioning as an end side member), a Fr suspension tower 34, and a pillar lower portion 36. The right half and the left half of the Fr cast component 28f are connected by a connecting portion 38. Such a Fr cast component 28f is manufactured by a large component integral casting technique called mega casting or giga casting.

[0050] Multiple elemental components 40 are joined to the Fr cast part 28f. The elemental components 40 may also be small modules 42 formed by combining multiple components. For example, the Fr cast part 28f has a dash module 43 and a tower bar module 45 joined to it as small modules 42.

[0051] The tower bar module 45 is constructed by connecting a thermal management unit 48a to a skeletal member called a suspension tower bar 46. The suspension tower bar 46 is a skeletal member that spans between a pair of left and right Fr suspension towers 34 and is bolted to the pair of Fr suspension towers 34. The thermal management unit 48a is a unit for regulating the temperature of heat-generating components (e.g., engine, battery, inverter, etc.) and includes, for example, a heat exchanger, a compressor, and piping through which a refrigerant flows (none of which are shown). Before being introduced into the sub-line, or while in the sub-line, the thermal management unit 48a is connected to the suspension tower bar 46 and modularized.

[0052] The dash module 43 is constructed by combining an on-board component, such as an air conditioning component 48b, an ECU 48c, and a brake pedal 48d, with a dash panel 44. The dash panel 44 is a partition separating the power unit compartment from the passenger compartment. Before being put into the sub-line, or during the sub-line, the on-board component 92, such as the air conditioning component 48b, is combined with the dash panel 44 to form a module.

[0053] In the subline, the suspension tower bar 46 of the tower bar module 45 is connected to the front suspension tower 34 of the front cast part 28f, and the dash panel 44 of the dash module 43 is connected to the connecting portion 38 of the front cast part 28f. Furthermore, a crash box 58 is connected to the front cast part 28f as an element component 40. The crash box 58 absorbs collision energy by breaking when the vehicle is struck head-on. In the subline, the crash box 58 is bolted to the front end of the front side member 32 of the front cast part 28f.

[0054] In a later step, the Fr absorption module 96 is placed on top of the crash box 58. Figure 7 is a schematic side view of the front end module 22f. This Fr absorption module 96 is an impact absorbing member, and its placement height is calculated to effectively absorb impact. Therefore, the Fr absorption module 96 is required to be placed at the height designed. And in order to place the Fr absorption module 96 at the height designed, the upper surface of the crash box 58 must be appropriately positioned. In this example, when fastening the crash box 58 to the Fr cast part 28f, the Fr cast part 28f is placed on a dedicated trolley 200 beforehand. This trolley 200 has a support projection 202 that supports a part of the crash box 58. The worker fastens the crash box 58 to the Fr cast part 28f while it is placed on this support projection 202. This fastens the crash box 58, and consequently the Fr absorption module 96, to the appropriate height.

[0055] Figure 5 is a perspective view of the rear end module 22r. The rear end module 22r is a module located at the rear of the vehicle. The rear end module 22r, manufactured on a sub-line, is fed into the main line and coupled to the center frame 10. The rear end module 22r includes an Rr cast part 28r and a plurality of elemental parts 40 that are arranged on the Rr cast part 28r. The Rr cast part 28r is manufactured by integrally casting a plurality of structural members located at the rear of the vehicle. For example, the right half and left half of the Rr cast part 28r each have a wheelhouse 50, an Rr side member 52 (which functions as an "end side member"), and an Rr suspension tower 54. The right half and left half of the Rr cast part 28r are connected by a connecting part 56. Such an Rr cast part 28r, like the Fr cast part 28f, is manufactured using a large-part integral casting technology called megacast or gigacast. The rear floor side member 59 is bolted to the rear side member 52 of the front cast part 28f as an element part 40. The rear floor side member 59 is part of the skeletal structure at the rear of the vehicle.

[0056] The front end module 22f and rear end module 22r, manufactured on the sub-line, are both fed into the main line and coupled to the center frame 10 (S14). Figure 6 is a perspective view showing the two end modules 22 coupled to the center frame 10. Note that in Figure 6, only the cast parts 28f and 28r are shown for clarity. In reality, the center frame 10 is coupled to the end modules 22f and 22r, which are modularized versions of the cast part 28 and the element part 40.

[0057] As shown in Figure 6, the front module 22f is connected to the front end of the center frame 10. The rear module 22r is connected to the rear end of the center frame 10. These connections are achieved, for example, by bolt fastening.

[0058] At this time, the inside of the center frame 10 is a hollow space 18. Therefore, when fastening the end module 22 to the center frame 10, the worker can use the inside of the center frame 10 as a workspace. As a result, the worker can access the end module 22 from the front, back, left, or right, making the fastening work easier.

[0059] Furthermore, elemental components 40 are pre-attached to the front and rear cast parts 28f and 28r, creating a modular design. This allows multiple elemental components 40 and cast parts 28f and 28r to be treated as a single part, making it easier to handle parts on the main line. Also, large parts such as cast parts 28f and 28r are prone to distortion. By connecting these cast parts 28f and 28r to the center frame 10 and positioning them relative to the center frame 10, the alignment of parts in subsequent processes becomes easier.

[0060] Once the two end modules 22 are connected to the center frame 10, the wide-area component 60 is then attached to the vehicle body (S16). The wide-area component 60 is an on-board component 92 that spans the front end module 22f, the center frame 10, and the rear end module 22r. The type of such wide-area component 60 is not particularly limited, but in this example, a wire harness 62 functions as the wide-area component 60. In Figure 6, the wire harness 62 is shown as a single line, but in reality, it has a main line that serves as the trunk and multiple branch lines that branch off from the main line. The main line of the wire harness 62 is a single line that extends from the lower part of the right pillar 36, as shown by the thick line in Figure 6, through the right center side member 12, the right rear wheelhouse 50, the left rear wheelhouse 50, the left center side member 12, and back to the lower part of the left pillar 36. In other words, the wire harness 62 is arranged in a roughly U-shape that opens forward. When these wire harnesses 62 are introduced into the main line, they are configured as a single unit, connected from start to finish. In the main line, the wire harnesses 62 are assembled to the center frame 10 in their single-unit form without being divided.

[0061] In this way, by configuring the wire harness 62 as a continuous single component, the cost of the component can be reduced and the assembly work can be simplified. This will be explained in comparison with a comparative example. For example, it is conceivable to pre-assemble the wire harness 62 into the end module 22. That is, the wire harness 62 is divided at the white circle portion in Figure 6, and multiple partial harnesses are prepared. Then, in the sub-line, the partial harnesses can be assembled into the cast parts 28f, 28r and the center frame 10. However, in this case, in the main line, after the end module 22 is connected to the center frame 10, the partial harnesses will need to be connected to each other separately. Also, connectors will naturally be required at the connection points, which will lead to an increase in the number of parts and, consequently, an increase in cost.

[0062] On the other hand, in this example, as described above, the wire harness 62 is not incorporated into the end module 22, but is fed into the main line as a single continuous component. Therefore, in this example, the work of joining the partial harness is unnecessary, and connectors for joining are also unnecessary. As a result, the work of assembling the wire harness 62 to the vehicle body can be simplified, and the cost of parts can be reduced. Also, as described above, the assembly of the wire harness 62 is performed after joining the end modules 22f and 22r to the center frame 10, and before joining the side module 66 and battery module 82, which will be described later, to the center frame 10. In this case, the worker can be positioned either on the outside of the vehicle body or on the inside of the center frame 10, and there are almost no parts that obstruct the work or view. Therefore, the worker can easily access the assembly location of the wire harness 62 from any position.

[0063] Once the wire harness 62 is connected, the worker then connects the instrument panel module 64 to the vehicle body (S18). The instrument panel module 64 is a modularized component formed by connecting multiple elemental components 40 to the instrument panel reinforcement 65. The instrument panel reinforcement 65 is a skeletal member that extends in the vehicle width direction behind the instrument panel. The elemental components 40 incorporated into the instrument panel module 64 include, for example, the instrument panel, steering wheel, and gauges. These elemental components 40 are connected to the instrument panel reinforcement 65 in a sub-line and modularized.

[0064] The worker fastens the instrument panel module 64 to the front end module 22f after fastening the front end module 22f to the center frame 10, but before fastening the side modules 66 and battery module 82 to the center frame 10. More specifically, both ends of the instrument panel reinforcement 65 are attached to the lower part 36 of the left and right pillars. By installing the instrument panel module 64 at this timing, the worker can work inside the center frame 10. Also, the instrument panel module 64 is a relatively large part. By installing the instrument panel module 64 before installing the side modules 66, the large instrument panel module 64 can be easily carried from outside the vehicle into the vehicle body. Furthermore, by pre-modularizing the parts related to the instrument panel, the handling of parts on the main line can be simplified.

[0065] In this example, the instrument panel module 64 is treated as a separate component from the front end module 22f. This is to avoid making the front end module 22f excessively large. However, depending on the vehicle's form and the manufacturing plant's equipment, the instrument panel module 64 may be incorporated into the front end module 22f on a sub-line. Alternatively, the instrument panel module 64 may be treated as part of the front end module 22f on the main line.

[0066] Once the instrument panel module 64 is connected, the worker then connects the side module 66 to the center frame 10 (S20). Figure 8 is a perspective view showing the connection of the side module 66 to the center frame 10. The side module 66 is a module that constitutes the side of the vehicle body. The side module 66 is constructed by joining multiple sheet metal members in a subline. Painting is also applied to the side module 66 in the subline. The lower edge of the side module 66 functions as a rocker 68, which is a skeletal member extending in the longitudinal direction of the vehicle. Arc-shaped wheel arches are formed on both the front and rear sides of the rocker 68, following the periphery of the wheel house 50.

[0067] Furthermore, the upper edge of the side module 66 functions as the upper pillar 72 and the roof side rail 74. The upper pillar 72 is a skeletal member positioned on both sides of the windshield glass (not shown). The lower end of the upper pillar 72 is located near the upper end of the lower pillar 36 of the Fr cast part 28f. The roof side rail 74 is a skeletal member positioned on both sides of the roof and extending in the longitudinal direction of the vehicle. A door opening 70 is formed between the roof side rail 74 and the rocker 68. In the illustrated example, a total of four door openings 70 are formed, two on each side. In addition to the sheet metal member, the side module 66 may also include other elemental parts 40. For example, the side module 66 may include a resin decorative part called a trim panel or electrical components such as lighting equipment.

[0068] In the main line, with the rocker 68 aligned with the center side member 12 in the vehicle width direction, the lower edge of the side module 66 is connected to the center frame 10 and the cast parts 28f, 28r (S20). For example, the lower edge of the side module 66 may be fastened to the center side member 12 and the cast parts 28f, 28r by bolts.

[0069] Once a pair of side modules 66 can be attached to the vehicle body, a roof cross member is attached to this pair of side modules 66 (S22). The roof cross member is a skeletal member that connects a pair of roof side rails 74. In this example, a header reinforcement 76 located in the middle of the roof and a back frame 78 located near the rear end of the roof function as the roof cross member. Of these, the back frame 78 is modularized in a subline by being attached to an antenna 80. By modularizing the back frame 78 and the antenna 80 in this way, workability around the roof can be improved.

[0070] In other words, when the back frame 78 and antenna 80 are separate, the antenna 80 must be attached to the main line after the back frame 78 has been connected to the roof side rail 74. When attaching the antenna 80, the worker must carry the antenna 80 into the vehicle and attach it to the back frame 78 while looking upwards in the cramped interior. This work was burdensome and time-consuming for the worker.

[0071] On the other hand, in the sub-line, if the antenna 80 is attached to the back frame 78 in advance, the worker can work in a spacious area, looking down on the back frame 78 and antenna 80 from above. Furthermore, in the main line, since it is only necessary to attach the modularized back frame 78 to the roof side rail 74, work efficiency is greatly improved. In addition, since the assembly work of the modularized back frame 78 is relatively simple, it can be automated by robots.

[0072] In this example, the header reinforcement 76 is treated as a single component, but the header reinforcement 76 may also be modularized with other component parts 40 (for example, lighting units or air conditioning components). Similar to the back frame 78, the header reinforcement 76 is located on the roof of the vehicle, so attaching the component parts 40 to them is a burden on the worker. By modularizing the header reinforcement 76 and component parts 40 in advance on a sub-line, the attachment work of these component parts 40 can be simplified, and automation by robots can be easily performed.

[0073] Next, in the main line, the back door, rear seats, glass roof, and trim (none of which are shown) are assembled to the vehicle body (S24). In other words, as many parts as possible that can be assembled are installed on the vehicle at this time, before the battery module 82, which will be described later, is installed. This is because at this time, the empty space 18 inside the center frame 10 can be used, making it easier to transport parts and perform the work.

[0074] Next, in the main line, the battery module 82 and the powertrain module 94 are connected to the vehicle body (S26, S28). Figure 9 is a schematic diagram showing how the battery module 82 and the powertrain module 94 are attached to the vehicle body.

[0075] The battery module 82 and the powertrain module 94 are pre-configured in a sub-line. The battery module 82 is a modularized unit formed by combining a battery pack 84 with elemental components 40 such as a seat cross member 86, a front seat 88, a console unit 90, and on-board components 92. The battery pack 84 is a unitized component in which multiple battery cells (not shown) are housed in a battery case. In this example, as shown in Figure 9, the battery pack 84 has a flat shape that spreads across the entire floor surface of the passenger compartment. A seat cross member 86 is attached to the upper side of the battery pack 84. The seat cross member 86 is a skeletal member that extends in the vehicle width direction and connects a pair of center side members 12. In the illustrated example, two seat cross members 86 are arranged side by side in the front-to-rear direction. Two front seats 88 are arranged side by side in the vehicle width direction on top of the seat cross member 86. A console unit 90 is also arranged between the two front seats 88. Furthermore, on-board components 92 such as an auxiliary battery are also arranged at the rear of the battery pack.

[0076] On the main line, the battery module 82 is fastened to the center frame 10. During this fastening, the vehicle in the process of being manufactured, including the center frame 10, is suspended and held in the air. That is, as shown in Figure 11, a transport rail 230 for transporting the vehicle body is located near the ceiling of the manufacturing plant. A crane 231 incorporated into this transport rail 230 lifts and holds the vehicle body while moving it along the transport rail 230.

[0077] In the main line, the battery module 82 is raised from the underside of the vehicle body and fastened to the center frame 10. Specifically, the flanges protruding from around the battery pack 84 are screwed to the underside of the center side member 12, and both ends of the seat cross member 86 are screwed to the sides of the center side member 12. In addition, electrical connections are made to the onboard components 92 and the components of the console unit 90 as needed.

[0078] As is clear from the explanation above, in this example, large components such as the Fr seat 88 are pre-assembled onto the battery pack 84. This configuration reduces the time required to assemble the large components. In other words, if the Fr seat 88 and seat cross member 86 were to be attached after the battery pack 84 had been assembled onto the center frame 10, these large components would have had to be brought in through the door opening 70, which would have taken time. Furthermore, even after bringing them in, much of the work would have to be done in the cramped space inside the vehicle, which would have prolonged the assembly time. On the other hand, as in this example, if large components such as the Fr seat 88 are pre-assembled onto the battery pack 84 on a sub-line, the delivery of the large components can be completed simultaneously with the assembly of the battery pack 84. In addition, the assembly work of large components such as the Fr seat 88 and on-board components 92 is performed in a spacious area outside the vehicle. Therefore, the time required for the work can be significantly reduced.

[0079] In this example, a multi-joint robot 210 (see Figure 9) is used to raise the battery module 82. The multi-joint robot 210 has multiple arms connected by joints and a fork hand 212 on which the battery module 82 can be mounted. The multi-joint robot 210 moves the fork hand 212, and by extension the battery module 82 mounted on the fork hand 212, in the horizontal and vertical directions by changing the posture of each of the multiple arms.

[0080] By using the articulated robot 210 to raise the battery module 82 in this way, the height at which the vehicle is positioned, and consequently the overall ceiling height of the factory, can be kept low. This will be explained in comparison with the comparative example shown in Figure 11. In the comparative example shown in Figure 11, the battery module 82 is placed on the lifting table 222 of the movable lifter 220. The movable lifter 220 moves to the underside of the vehicle in the process of being manufactured as needed, and raises the battery module 82.

[0081] Here, a drive mechanism 224 for raising and lowering the lifting table 222 is provided on the underside of the lifting table 222. As a result, the lifting table 222 is located several tens of centimeters above the factory floor. In this case, the battery module 82 placed on the lifting table 222 is naturally also located above it. This makes it easier for the upper part of the Fr seat 88 incorporated into the battery module 82 to interfere with the vehicle. To avoid such interference, it is conceivable to raise the transport rail 230 and, consequently, the factory ceiling, or to partially lower the floor only around the movable lifter 220. However, such measures are costly. Also, if the transport rail 230 is made excessively high, the work efficiency in the processes before and after the assembly of the battery module 82 will be reduced.

[0082] On the other hand, in this example, as described above, the battery module 82 is transported by the articulated robot 210. With the articulated robot 210, the battery module 82 can be received at a height close to the floor and raised. As a result, even if the lifting height of the vehicle is low, interference between the battery module 82 and the vehicle is less likely to occur. Consequently, there is no need to raise the ceiling of the factory or partially lower the floor. In addition, since the lifting height of the vehicle can be lowered, the work efficiency in other processes is also improved.

[0083] The powertrain module 94 is also attached to the vehicle from underneath by the articulated robot 210. The powertrain module 94 is a device that transmits the driving force of the power source to the tires. Typically, the powertrain module 94 includes a suspension, gearbox, drive shaft, and differential gear, and may also include at least one of a traction motor, inverter, and controller. Such powertrain modules 94 are also pre-assembled on a sub-line. Once placed on the main line, the powertrain modules 94 are transported and attached to the vehicle by the articulated robot 210, similar to the battery module 82.

[0084] Subsequently, various body shell parts, decorative parts, and fitting parts are attached to the vehicle (S30). The parts attached here include, for example, the under cover, windshield glass, side doors, hood, fenders, headlights, and the Fr absorption module 96. Of these parts, the attachment of the Fr absorption module 96 (S32) will be explained with reference to Figure 10. Figure 10 is a schematic plan view showing how the Fr absorption module 96 is connected to the front end module 22f. The Fr absorption module 96 is a module that includes the Fr bumper 100 and the bumper reinforcement 98, and is located at the front end of the vehicle. More specifically, the left and right ends of the bumper reinforcement 98 are fastened to the left and right ends of the cast part 28.

[0085] The center of the Fr absorption module 96 in the vehicle width direction is required to coincide with the center of the hood (not shown) in the vehicle width direction, which will be assembled later. Here, when assembling the Fr absorption module 96, it is conceivable to position the Fr absorption module 96 relative to the front end module 22f using either the left or right side of the bumper reinforcement 98 as a reference. However, the Fr cast part 28f, which is usually a large cast part, is prone to relatively large shape errors, and the vehicle width direction position of its right front and left front parts tends to vary. If the Fr absorption module 96 is assembled using either the right front or left front part as a reference, the center of the Fr absorption module 96 in the vehicle width direction may be significantly misaligned with the vehicle width direction center of the hood.

[0086] Therefore, in this example, prior to assembling the Fr absorption module 96, a positioning jig 240 is attached to the Fr cast part 28f so that the center of the Fr cast part 28f can be determined. The positioning jig 240 has fixing members 242 that are screwed into the right and left portions of the Fr cast part 28f, a connecting bar 244 that is connected to the left and right fixing members 242, and an alignment part 246 that is positioned at the center of the connecting bar 244. The worker aligns the center position of the bumper reinforcement 98 in the vehicle width direction with the alignment part 246 of the positioning jig 240 and fastens the bumper reinforcement 98 to the Fr cast part 28f. As a result, the vehicle width direction centers of the Fr absorption module 96, the front end module 22f, and the hood are aligned. As a result, the build quality can be improved.

[0087] As is clear from the above explanation, in this example, the front module 22f, rear module 22r, side module 66, and battery module 82 are constructed on the sub-line, and these are connected to the center frame 10 on the main line. With this configuration, the multiple modules 22f, 22r, 66, and 82 are positioned relative to the center frame 10. As a result, positional errors between modules can be kept to a minimum. In addition, by modularizing the multiple parts that are arranged on the front, rear, sides, and bottom of the vehicle in advance on the sub-line, the handling of parts on the main line becomes easier. It should be noted that the configurations described above are all examples, and other configurations may be changed as appropriate as long as they have the configuration described in claim 1.

[0088] For example, in the above description, the end module 22, wide-area component 60, side module 66, and battery module 82 are connected in that order, but this order may be changed as appropriate. Also, the configuration of each sub-module 20 may be changed as appropriate. That is, the configuration of a sub-module is not limited as long as it is modularized in a sub-line and includes structural members of the vehicle body. Therefore, for example, the front end module 22f may have a configuration that does not include at least one of the dash module 43 and the tower bar module 45. Also, in the above-described cast parts 28f and 28r, the right wheelhouse and the left wheelhouse are cast as a single unit, but these may be made of separate parts.

[0089] 10 Center frame, 12 Center side member, 14 Front center cross member, 16 Rear center cross member, 18 Empty space, 20 Partial module, 22 End module, 22f Front end module, 22r Rear end module, 28 Cast parts, 28f Front cast parts, 28r Rear cast parts, 30, 50 Wheelhouse, 32 Front side member, 34 Front suspension tower, 36 Lower pillar, 38 Connecting section, 40 Element parts, 42 Small module, 43 Dash module, 44 Dash panel, 45 Tower bar module, 46 Suspension tower bar, 52 Rear side member, 54 Rear suspension tower, 56 Connecting section, 58 Crash box, 59 Rear floor side member, 60 Wide area parts, 62 Wire harness, 64 Instrument panel module, 65 Instrument panel reinforcement, 66 Side module, 68 Rocker, 70 Door opening, 72 Upper pillar, 74 Roof side rail, 76 Header reinforcement, 78 Back frame, 80 Antenna, 82 Battery module, 84 Battery pack, 86 Seat cross member, 88 Front seat, 90 Console unit, 92 Onboard components, 94 Powertrain module, 96 Front absorption module, 98 Bumper reinforcement, 100 Front bumper, 200 Bogie, 202 Support protrusion, 210 Articulated robot, 212 Fork hand, 220 Movable lifter, 222 Lifting table, 224 Drive mechanism, 230 Transport rail, 231 Crane, 240 Positioning jig, 242 Fixing member, 244 Connecting bar, 246 Alignment part.

Claims

1. A method for manufacturing a vehicle, comprising: preparing partial modules including structural members for the vehicle body in each of a plurality of sublines; and connecting the plurality of partial modules to a center frame in a mainline in order to construct the vehicle body, wherein the center frame is constructed by connecting a pair of center side members extending in the longitudinal direction of the vehicle and a pair of center cross members extending in the width direction of the vehicle in a rectangular shape.

2. A method for manufacturing a vehicle according to claim 1, characterized in that, at the time the center frame is fed into the main line, the inside of the substantially rectangular area enclosed by the pair of center side members is an open space into which a worker can enter.

3. A method for manufacturing a vehicle according to claim 1, wherein the plurality of sub-modules include end modules that constitute the front or rear of the vehicle body, and the end module includes a cast part in which a pair of left and right end side members are integrally cast, and element parts assembled to the cast part.

4. A method for manufacturing a vehicle according to claim 3, wherein the end module includes a front end module that constitutes the front part of the vehicle body, the element component includes a sub-module which is a modularized component comprising a skeletal member coupled to the cast component and an on-board component assembled to the skeletal member, and the on-board component includes at least one of a thermal management unit, an air conditioning component, an ECU, and a pedal.

5. A method for manufacturing a vehicle according to claim 1, wherein the partial module includes a side module that constitutes the side of the vehicle body, the side module includes a rocker extending in the longitudinal direction of the vehicle, and the side module is coupled to the center frame in the main line such that the rocker is aligned with the center side member in the vehicle width direction.

6. A method for manufacturing a vehicle according to claim 5, wherein the partial module further includes a front end module that constitutes the front part of the vehicle body, and in the main line, after the front end module is coupled to the center frame and before the side module is coupled to the center frame, an instrument panel module is coupled to the front end module.

7. A method for manufacturing a vehicle according to claim 1, wherein the partial module includes a front end module constituting the front of the vehicle, a rear end module constituting the rear of the vehicle, a side module constituting the side of the vehicle, and a battery module constituting the bottom of the vehicle, and wherein, in the main line, at least one of the front end module, the rear end module, and the side module is coupled to the center frame, and then the battery module is coupled to the center frame.

8. A method for manufacturing a vehicle according to claim 7, characterized in that the battery module includes a battery, a seat cross member connecting the pair of center side members above the battery, and a front seat disposed on the seat cross member.

9. A method for manufacturing a vehicle according to claim 8, characterized in that, on the main line, the vehicle being manufactured is transported while suspended and held in the air, and the battery module is transported from the underside of the vehicle toward the center frame by a hand of an articulated robot.

10. A method for manufacturing a vehicle according to claim 1, wherein the partial module includes a front end module that constitutes the front part of the vehicle body and a rear end module that constitutes the rear part of the vehicle body, and in the main line, the front end module and the rear end module are connected to the center frame, and thereafter, a wide-area component which is an on-board component that spans from the front to the rear of the vehicle body is arranged via the center frame.

11. A method for manufacturing a vehicle according to claim 10, characterized in that the wide-area component is pre-configured as a single component, and in the main line, the wide-area component is assembled to the center frame in a state where it is a single component connected from the start end to the end end.

12. A method for manufacturing a vehicle according to claim 10, characterized in that the wide-area component is a wire harness.

13. A method for manufacturing a vehicle according to claim 10, wherein the partial module further includes a battery module which includes a battery located under the floor of the vehicle, and the wide-area components are arranged in the main line before the battery module is coupled to the center frame.

14. A method for manufacturing a vehicle according to claim 1, wherein the partial module includes a front end module constituting the front of the vehicle, a rear end module constituting the rear of the vehicle, a side module constituting the side of the vehicle, and a battery module constituting the bottom of the vehicle, and in the main line, the front end module and the rear end module are coupled to the center frame, then the side module is coupled to the center frame, the front end module, and the rear end module, and then the battery module is coupled to the center frame.

15. A method for manufacturing a vehicle according to claim 1, wherein the partial module further includes a battery module which includes a battery disposed under the floor of the vehicle, and in the main line, a portion of the wide-area component is disposed on the upper surface of the center frame, and the battery module is coupled to the lower surface of the center frame.

16. A vehicle characterized by comprising: a center frame formed by connecting a pair of left and right center side members and a pair of front and rear center cross members to each other in a rectangular shape; and a plurality of partial modules, each including a structural member of the vehicle body, and connected to the center frame.

17. A vehicle according to claim 16, wherein the plurality of submodules include a front end module constituting the front of the vehicle and a rear end module constituting the rear of the vehicle body, and further comprises a wide-area component that spans from the front end module through the center frame to the rear end module.

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