GB2378157A

GB2378157A - Vehicle construction

Info

Publication number: GB2378157A
Application number: GB0118731A
Authority: GB
Inventors: Neil John Pitchford; Michael David Shergold
Original assignee: Land Rover UK Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2001-08-01
Filing date: 2001-08-01
Publication date: 2003-02-05
Also published as: GB0118731D0

Abstract

A method of constructing a motor vehicle body, the first stage of construction is to produce a module 11 comprising the front end portion forward of the vehicle door frames 13. The front end module 11 typically includes the front end floor pan 12, front side members 14, door frames 13 and bulkhead. At the next stage a rearward extension to the floor pan 22, 23 may be added to the front module, this construction will vary depending on whether it is a long or short wheel base vehicle. Rear doors 31 are fitted and then the vehicle roof 32. This type of modular production can be used for the construction of 4 x 4 off road vehicles and helps to better utilise assembly line and manpower facilities.

Description

Vehicle Construction Field This invention relates to motor vehicle construction and in particular to the construction of vehicles having a number of variants.

Background of the Invention Some vehicles, in particular 4 X 4 off-road vehicles, are produced as a basic vehicle having a large number of variants. These vehicles may be presently built on assembly lines in which body components are either built onto a separate chassis frame or body of unitary construction.

Since different variants require different body parts, the work content in building the different variants can differ greatly from variant to variant. This leads to poor utilisation of the assembly line facility and manpower.

It is not a simple matter to replace the build method of such vehicle with the conventional unitary (or monocoque) body construction since the conventional underbody and bodysides sub-assemblies would require different body panels and different modes of assembly. Such diversity requires large numbers of press tools leading to high tooling costs and requires assembly lines having a high degree of flexibility.

The present invention provides for a method of assembly of

a multi-variant vehicle and seeks to maximize the use of common assembly cells or areas and common components.

I Statements of Invention According to the present invention there is provided a method of construction of a motor vehicle body which comprises as a first stage the construction of a module comprising the front end portion of the body forward of the vehicle front door frames.

The front end portion module is common to all variants and may comprise at least the front end floor pan, front side members, front door frames, dash, and bulkhead. The module may optionally include at least one of cross members, the bonnet, fenders, and windscreen.

At the next stage a rearward extension to the floor pan may added to the front module. Alternatively the front module may have a front cab back module added thereto.

The rearward extension may comprise a rear floor pan module for shorter wheel base vehicle, or a mid-floor section module for longer wheel base vehicles. In the case of the latter either a cab back module or the rear floor module is added to the mid-floor section.

The longer wheel base vehicle having side modules added to the mid-floor section. Common rear quarter modules may be

added to the rear floor pan modules for both short wheel base versions and longer wheel base versions.

I Rear door modules may then be fitted to the rear floor pan modules of either version, with the roof modules also being fitted to the respective vehicle types.

Another aspect of the invention provides a motor vehicle body construction made by a method according to the present invention.

Yet another aspect provides a motor vehicle body construction formed from a plurality modules, one of said modules comprising the front end portion of the body forward the vehicle B post.

Preferably, said one module comprises at least the front end floor pan, front side members, front door frames, dash, and bulkhead.

The construction may further include a rear floor pan module, rear quarter modules, and roof modules.

Description of the Drawings The invention will be described by way of example and with reference to the accompanying drawings in which: Fig 1. is a schematic drawing showing the different stages in the build of multiple variants of

a vehicle using modular construction according to the present invention, and Fig. 2 is a flow diagram showing the assembly cells for handling the modules for the different variants.

'"'" Detailed Description of the Invention With reference to Figs. 1 & 2, there is shown an assembly process for the building of vehicle bodies for a vehicle having a number of variants for example long wheel base, short wheel base, Pick-up, hard top, soft top, Station Wagon etc. The system seeks to utilise modular components which are built and assembled together so as to maximise the use of particular modules and allow the different volume modules to be built at separate stations without too much disruption to the overall flow of the main assembly lines.

At stage 1, there is built a front end portion module 11 which is subsequently used in all other variants. At this stage the front floor pan 12, door frames 13 including A & B posts, dash (not shown) side members 14, bulkhead (not shown), front cross members 15, and roof cross members 16 are assembled together to form the front module 11. It may also be desirable at this stage to add the front screen 17, fenders 18, and bonnet 19. This module 11 is built on a high volume line, Front End Assembly Cell 101 in Fig 2, and now passes onto three different lower volume processes,

Stage 2A, Stage 2B or Stage 2C.

At stage 2A a cab back module 21 is added to the front end module 11 to form a cab which is assembled to a pick-up bed for manufacture of a pick-up variant. This occurs in Cab Back Assembly Cell 201. About 20% of the production volume passes into Cell 201.

At Stage 2B a mid-section floor pan module 22 is added to the front end module 11. This now used in most long wheel base variants. This occurs in the Mid-Floor Cell 202. About 50% of production volume passes into Cell 202.

At stage 2C a rear section floor pan module 23 is added to the front end module 11. This is now used in most short wheel base variants say about one third of the production volume. This occurs in Rear Floor Assembly Cell 203.

The bodies for the short wheel base variants then pass from stage 2C in Cell 203 to Stage 3C where dependant upon the variant required, modules comprising at least some of the upper and lower rear quarter panels 35,36, rear frames 37 and roof supports 38 are added to the vehicle body. This occurs in the Rear Quarter Assembly Cell 303.

The vehicle bodies for the long wheel based variants leaving stage 2B pass into Stage 3B where rear door modules 31 and associated roof supports 32 are added. This occurs

in the Rear Door Ring Cell 302.

From Stage 3B, the vehicle body may be passed to stage 4A to receive a cab back module 21 to form a enlarged cab for assembly to a pick-up bed for manufacture of a pick up variant. This occurs when the body is moved from Cell 302 to Cab Back Cell 201 and may account for about 16% of the production.

From Stage 3B the vehicle body may also be passed to Stage 4B where a rear floor pan module 23 is added to form some of the long wheel base variants. This occurs when the vehicle body is moved from the Rear Door Ring Assembly Cell 302 into the Rear Floor Assembly Cell 203 and accounts for about 31% of the production.

The bodies for the long wheel base variants then pass from stage 4B in Cell 203 to Stage 5, where dependant upon the variant required, modules comprising at least some of the upper and lower rear quarter panels 35,36, rear frames 37 and roof supports 38 are added to the vehicle body. This occurs in the Rear Quarter Assembly Cell 303.

It can be seen that by setting up particular assembly cells most cells handle about half or more of the production volume, and the least used cell handles about one third of the production volume, even though particular variants may account for as little as 2-5% of the total volume.

The part assembled bodies from stages 2A, 3C, 4A, & 5 may all pass down a common assembly line Stage 6 for the fitting of roof modules, side door modules, and rear door modules.

From stage 6, the completed bodies for the different variants are then transported for painting.

The variant bodies are then assembled to either rolling chassis frames, or in the case of a unitary body construction have engines, power trains etc. assembled thereto. The front end bodies for the pick up variants are diverted to a dedicated area for the assembly to pick-up beds.

By using common parts e. g. front door frames and doors, the above assembly method allows for a balanced work content for a large number of variants and minimum costs.

The assembly facility can be utilised to support a wide range of different production volumes for each variant and which may differ in proportions from those disclosed above.

The system also allows for part complete vehicle bodies to be removed at convenient work stages for specially built variants.

Claims

Claims 1. A method of construction of a motor vehicle body which comprises as a first stage the construction of a module comprising the front end portion of the body forward of the vehicle front door frames.
2. A method as claimed in Claim 1 wherein the front end portion module comprises at least the front end floor pan, front side members, door frames, dash, and bulkhead.
3. A method as claimed in Claim 2 wherein the module further includes at least one of cross-members, the bonnet, fenders, and windscreen.
4. A method as claimed in any one of Claims 1 to 3 wherein at the next stage a rearward extension to the floor pan is added to the front module.
5. A method as claimed in Claim 4 wherein the rearward extension comprises a rear floor pan module.
6. A method as claimed in Claim 4 wherein the rearward extension comprises a mid floor section module.
7. A method as claimed in Claim 6, wherein a rear floor pan module is added to the mid floor section module.

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8. A method as claimed in Claim 6 or Claim 7, wherein side members are added to the front end module and mid-floor section module.
9. A method as claimed in any one of Claims 1, 2, 3, and 8 wherein a cab back module is added to the front module or the mid section module respectively.
10. A method as claimed in Claim 5 or Claim 8 wherein rear quarter modules are added to the rear floor pan modules.
11. A method as claimed in Claim 10 wherein rear doors are added to the rear floor pan module.
12. A method as claimed in Claim 10 or Claim 11 wherein roof modules are added to the front modules etc..
13. A motor vehicle body construction made by a method as claimed in any one of claims 1 to 12.
14. A motor vehicle body construction which comprises a plurality modules, one of said modules comprising the front end portion of the body forward of the vehicle B post.
15. A construction as claimed in Claim 14 wherein said one module comprises at least the front end floor pan, front side members, door frames, dash, and bulkhead.

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16. A construction as claimed in Claims 14 & 15 and further including a rear floor pan module, rear quarter modules, and roof modules.
17. A construction as claimed in Claim 16 and further including a mid-section floor module and associated side members.