GB2478656A

GB2478656A - Installation unit positioning for front of vehicle

Info

Publication number: GB2478656A
Application number: GB201104154A
Authority: GB
Inventors: Klaus Labbe
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2010-03-12
Filing date: 2011-03-11
Publication date: 2011-09-14
Anticipated expiration: 2031-03-11
Also published as: GB2478656B; GB201104154D0; CN102190022B; CN102190022A; DE102010011238A1

Abstract

The invention provides an installation unit for a motor vehicle and a method for creating reference positions 3,4 for the installation unit. The installation unit comprises a motor vehicle front section of a vehicle body shell between front regions of two longitudinal members 1, 2. The installation unit is mounted relative to reference positions 3, 4 and the reference positions 3, 4 are disposed on mounting shoes 5, 6. The mounting shoes 5, 6 are disposed and fixed on vertical supporting members 7, 8 of a component group 22 pre-assembled on a tool plate 23 on both sides of an engine bay 10 at front ends 11,12 of each longitudinal member 1, 2. A hole (9 see fig 6) for locating a jig or a robot arm may be provided. The invention seeks to minimize tolerance stack up and adjustment tasks involved in compensating for tolerance stack up, for instance when fitting a lamp housing, front wings and bonnet hinges.

Description

DESCRIPTION

INSTALLATION UNIT FOR A MOTOR VEHICLE AND METHOD FOR

CREATING REFERENCE POSITIONS FOR THE INSTALLATION UNIT

The application relates to an installation unit for a motor vehicle and a method for creating reference positions for the installation unit. The installation unit comprises a motor-vehicle front section of a vehicle body shell between front regions of two longitudinal members.

The document DE 10 2004 011 523 Al discloses a known installation unit for a motor-vehicle front section, wherein this known installation unit is provided for installation in the body shell. The known installation unit in the motor-vehicle front section is used to house built-in fittings, whereby the manufacturing costs and the maintenance expenditure can be reduced with the aid of the known installation unit. To this end, the known installation unit is disposed in front of a bulkhead separating an engine bay and a passenger compartment or * engine bay bulkhead in the engine bay. Further parts of the * ***** * body shell are then mounted in the area of the engine bay until the main components of the motor-vehicle front section of the body shell such as bonnet, wings, lamp carriers and further parts are mounted in a precisely * fitting manner prior to and for painting. S... *5 ** * . . S *

In order to compensate for the cumulative tolerances of a previously observed tolerance chain during the final assembly of the body shell before painting, the main components should be mounted by means of appropriate re-adjustable connecting elements. Such re-adjustable connecting elements can be long-hole screw connections, long-hole clips or clamping disk connections in multi-dimensional re-adjustment openings for compensating for the tolerances of the individual parts added by the tolerance chain of the body shell. This has the disadvantage that on the one hand, the deviations to be compensated have appreciable dimensions and on the other hand, the assembly of the main components of the vehicle front section is cost-intensive.

It is the object of the application to provide new zero tolerance positions for the installation unit of the motor vehicle front section, which simplify the assembly of the motor vehicle front section and make it more cost-effective.

This object is achieved with the subject matter of the independent claims. Advantageous further developments of the solution are obtained from the dependent claims.

*.,... * S

In one embodiment of the application, an installation unit for a motor vehicle and a method for creating reference S. SI * * positions for the installation unit is provided. The installation unit comprises a motor vehicle front section of a vehicle body shell between front regions of two S...

S S

longitudinal members. The installation unit is mounted relative to reference positions and the reference positions are disposed on mounting shoes. The mounting shoes are disposed and fixed on vertical supporting members of a component group pre-assembled on a tool plate on both sides of an engine bay at front ends of each longitudinal member.

In this context, a vehicle body shell is understood as the body shell of the vehicle prepared for painting with mounted vehicle front section which substantially consists of the main components bonnet, front wings, lamp housing and general installation parts to which the main components are fixed, wherein engine and vehicle axles as well as exhaust system are not yet installed.

The installation unit according to the application has the advantage that the tolerances which have already occurred in the pre-assembled component group on the tool plate are compensated with new reference positions upon attachment of mounting shoes which have the reference positions. A hitherto-existing tolerance chain for the motor vehicle front section of the body shell is prematurely broken by the new reference positions of the mounting shoes. For the final assembly of the motor vehicle front section of the vehicle body shell, new reference points are advantageously created so that during the assembly of the main components * of the motor vehicle front section such as bonnet, wings * 4 and lamp housing as well as general installation parts on * S. I*S * 5 which the main components are fixed, a cost-intensive, time-consuming re-adjustment of the main components is * eliminated.

At least one fitting hole is provided as a new reference position on each of the mounting shoes. This fitting hole in practice forms a new beginning of a tolerance chain which, however, as a result of the few components which are still missing and to be assembled, is relatively short and therefore relatively small in respect of dimensional deviations so that main components mounted directly with reference to this reference position require no re-adjustment.

The fitting hole in each of the mounting shoes can either be used as an optical reference position or as a mechanical reference position.

In the case of mechanical reference, either an assembling jig having an appropriate dowel pin matched to the fitting hole is used or in production a robot arm is equipped with a corresponding dowel pin so that the components of the installation unit can be mounted exactly in relation to the position of the dowel pin.

In the case of an optical usage of the fitting hole, for example, appropriate optical sensors are disposed on the robot arm which attach the components to be mounted on the already pre-assembled assembly in relation to the fitting hole. * *

S

Furthermore, a mounting plate for respectively one lamp housing is provided on the mounting shoes relative to the * 5 reference position. This mounting plate can also be connected to corresponding servomotors, wherein the servomotors can pivot the lamp housing as a function of the steering lock, for example, when driving round bends.

* Consequently, the mounting plate for respectively one lamp housing can have an extremely complex structure for correspondingly complex kinematics in order, for example, to track the headlamp beam on bends as a function of the steering lock.

The exact positioning, for example, of hinges for the bonnet is also simplified by the new reference positions, wherein at the same time, the hinges for the bonnet can be significantly simplified accompanied by a saving of weight since re-adjustable connecting elements such as for example, screws which cooperate with elongate holes or over-dimensioned adjusting openings, can be dispensed with.

The same applies for wing retainers which can be fixed at a defined distance from the reference positions of the mounting shoes for front wings on an assembly pre-assembled on a tool plate. This fixing is ensured in a precisely fitting manner by the new reference positions.

It is further provided that the front ends of the longitudinal members are connected by means of a forward-mounted lower crossbar structure. In this case, this connection already belongs to the pre-assembled assembly on the tool plate, which has the advantage that the spacing of the front ends of the longitudinal members is defined and S.....

* fixed even before the new reference points are mounted with S.....

* the mounting shoes on the perpendicular supporting members so that manufacturing tolerances in relation to the vehicle width and therefore the spacing of the longitudinal members from one another can be completely compensated by the new reference positions. S... SS *S * . S

All dimension-determining and dimension-modifying production steps take place before the attachment of the mounting shoes which is why it is advantageous, for example, to have installed the lower crossbar structure before the installation of the mounting shoes. At the same time, the lower crossbar structure is not fixed directly at the front ends of the longitudinal members, rather a crashbox as an extension of the longitudinal members is provided in each case between the front ends and the crossbar structure as impact protection and damping. This lower crossbar structure is disposed so deeply that on the one hand it does not impede assembly work of assembly staff in the area of the engine bay and on the other hand, it ensures that during operation of the vehicle the lower crossbar structure damps the effect of a frontal collision and if persons are involved, ensures that they are not affected in the sensitive knee area but with the aid of the lower crossbar structure can be raised from the ground and intercepted by the vehicle front side or the motor vehicle front section and held gently until the vehicle comes to a stop.

A further embodiment of the application provides that in addition to the at least one fitting hole, the mounting shoes have mounting means for mounting further components *:** of the motor vehicle front section. Such mounting means can comprise rivet holes for compression rivets for the non-detachable final mounting of a front-section structural member. Such a front-section structural member is disposed above the lower crossbar structure on the mounting shoes and terminates the engine bay towards the front side. The mounting shoes therefore provide the possibility for detachably fixing such a front-section structural member which blocks access to the engine bay, following the final mounting of the wings and the bonnet on the mounting shoes.

Preferably screw connections are used for the detachable fixing.

In addition, mounting retainers for a front trim can be fixed in the frontal direction on the mounting shoes. These mounting retainers are in turn mounted with reference to the reference positions of the mounting shoes in the frontal direction so that a re-adjustment can be dispensed with when attaching the front trim.

A method for creating new reference positions for an installation unit comprising a motor vehicle front section of a vehicle body shell begins with an alignment of mounting shoes into the new reference positions on vertical supporting members of front ends of longitudinal members on both sides of an engine bay of a component group pre-assembled on a tool plate whilst compensating for previous manufacturing tolerances of the pre-assembled component group. At the same time, the mounting shoes together with an upper crossbar structure of an engine bay bulkhead relative to a previous zero position of the tool plate with the pre-assernbled component group are brought by an assembly robot into a mounting position of the new reference positions and fixed. S. S. * S *

* This method has the advantage that the previous tolerance chain can be broken with the aid of a three-point detection *..* and a new zero tolerance starting position is created with the reference positions. Subsequent assembly work can therefore be carried out more precisely and with a lower tolerance play, which saves assembly time and assembly costs since the fit-determining operations of the per-assembled component group are already carried out before fixing the mounting shoes with new reference positions.

Previous tolerances are compensated by attaching the mounting positions and new reference positions are created for the further assembly.

With the aid of these new reference positions, wing retainers of the installation unit can be mounted relative to the reference positions of the mounting shoes and the front wings can then be fixed on the wing retainers without re-alignment. The same applies for the mounting of the bonnet hinges or the bonnet with hinges for the cover of the engine bay and for the mounting of retainers for lamp carriers.

The subject matter of the application is now explained in detail with reference to the appended figures.

Figure 1 shows a schematic perspective partial view of a component group on a tool plate with mounting shoes of an installation unit for a motor * vehicle; **S** * * * S.....

* Figure 2 shows a schematic perspective partial view of a mounting shoe mounted on a component group with attached mounting retainer for a front trim; *..* * S *. S. * . S S *

Figure 3 shows a schematic perspective partial view of a pre-assembled component group with attached upper front-section structural member; Figure 4 shows a schematic perspective partial view of a mounting shoe with attached upper front-section structural member and a mounting retainer for a lamp housing; Figure 5 shows a schematic perspective partial view of a pre-assembled component group with mounted front-section structural member and a crossbar of the front trim; Figure 6 shows a schematic perspective view of a mounting shoe on a vertical supporting member with attached wing retainer; Figure 7 shows a schematic perspective partial view of a mounting unit with attached front wings.

Figure 1 shows a schematic perspective partial view of a pre-assembled component group 22 on a tool plate 23 with mounting shoes 5 and 6 of an installation unit for a motor vehicle. The installation unit for the motor vehicle comprises a motor vehicle front section of the vehicle body shell. The body shell comprises all the pre-assembled : * * components of the vehicle body shell to be painted together by dip or spray painting including the bonnet, the front wings and the lamp housings as well as general parts used for fixing main components of the motor vehicle front -10 -section or provided for the attachment of further separately painted components such as, for example, a plastic front trim.

In this case, the assembly 22 pre-assembled on the tool plate 23 comprises two longitudinal members 1 and 2 which have supporting members 7 and B arranged vertically at the front ends 11 and 12 thereof. The longitudinal members 1 and 2 are interconnected via a lower crossbar structure 15, the lower crossbar structure 15 being connected via crashboxes 31 and 32 to the front ends 11 and 12 of the longitudinal members 1 and 2. The longitudinal members 1 and 2 are fixed by means of this lower crossbar 15 in relation to a vehicle width in the front region of the vehicle.

In the regions of this pre-assembled assembly 22 marked by circles 33 and 34, mounting shoes 5 and 6 with reference positions 3 and 4 are attached at the upper ends of the supporting members 7 and 8, the mounting shoes 5 and 6 being at the same time connected to an upper crossbar structure 24 which forms the termination and upper region of an engine bulkhead 25. In this case, these three components, i.e., the mounting shoes 5 and 6, and the upper crossbar structure 24 of the engine bay bulkhead 25 are arranged by a production robot relative to the zero position of the component group 22 pre-assembled on the tool plate 23.

The tolerances which have occurred so far during assembly of the pre-assembled assembly 22 are therefore compensated and these three components can now be fixed on the -11 -component group relative to the initial zero position on the tool plate 23. The mounting shoes 4 and 5 are thereby connected detachably or in a firmly bonded manner to the supporting members 7 and 8. The reference positions 3 and 4 can thus be reference points for the installation unit of the motor vehicle front section, where all previous tolerances are compensated with fitting holes 9 and therefore the previous tolerance chain of the pre-assembled assembly is broken or is returned to a zero reference by the reference positions 3 and 4 of the mounting shoes 5 and 6.

All the following components of the vehicle front section can therefore be attached to the pre-assembled assembly 22 without complex compensation for tolerances in relation to the reference positions 3 and 4 of the mounting shoes 5 and 6 fixed on the vertical supporting members.

Figure 2 shows a schematic perspective partial view of a mounting shoe 6 mounted on a component group 22 with attached mounting retainer 17 for a front trim. Two reference positions 3 and 4 are shown on the mounting shoe 6 which are critical for the attachment of the mounting retainer 17 for a front trim. In addition, Figure 2 shows a mounting plate 14 for a lamp housing. This mounting plate 14 for a lamp housing in turn has a reference position 13 which is disposed in relation to the reference position 4 of the mounting shoe 6, which is marked by a direction * 1 arrow A in Figure 2. The mounting retainer 17 is flange-mounted to the mounting shoe 6 and carries, as will be shown subsequently, a crossbar for a front trim. * I **** 0* *l * * * *

-12 -Figure 3 shows a schematic perspective partial view of a pre-assembled component group 22 with attached upper front-section structural member 16. This front-section structural member 16 terminates the engine bay 10 in the front upper region and is fixed on the mounting shoes 5 and 6 by means of screw connections 35. The width of the vehicle is therefore defined at the sametime. A bonnet lock 26 is disposed at the centre of the front-section structural member. The bonnet lock 26 is mounted together with the front-section structural member 16 after all the general components such as retainers for the engine and for engine units have been disposed in the engine bay.

Figure 4 shows a schematic perspective partial view of a mounting shoe 6 with attached upper front-section structural member 16 and a mounting retainer 14 for a lamp housing in detail. This partial view clearly shows that the mounting shoe 6 is fixed on the vertical supporting member 8 and despite the mounted front-section structural member 16, has at least one reference position 4 which is not covered by the front-section structural member 16 and is therefore available as a reference point for the installation unit of the motor vehicle front section. The mounting plate 14 for a lamp housing projects beyond the mounting shoe 6 and is disposed thereon in such a manner that a lamp housing can be attached with reference to a further reference position 13 for the lamp housing. *. ..

* Figure 5 shows a schematic perspective partial view of a pre-assembled component group 22 with the pre-assembled upper front-section structural member 16 and with an additional crossbar 27 which is disposed in the direction -13 -of travel in front of the front-section structural member 16 and supports a front trim. As has already been mentioned briefly above, this crossbar 27 is disposed and fixed on the mounting retainers 17 for a front trim.

Figure 6 shows a schematic perspective partial view of a mounting shoe 6 on a vertical supporting member 8 with attached wing retainer 18 from a different viewing angle compared with the previous Figures 1 to 5. The reference positions 3 and 4 on the mounting shoe 6 can again be seen and the transition to the vertical support 8. Adjoining this at an angle is the wing retainer 18 with further reference positions 28 and 29 which for their part also have fixing openings 36 in some cases in order to fix the wing onto the wing retainer 18 which is aligned relative to the reference positions 3 and 4.

Figure 7 shows a schematic perspective partial view of an installation unit 30 with attached front wings 20 and 21 in the region of the wing retainers 18 and 19. Merely the front-section structural member 16 can be seen in this diagram and in addition to the mounting shoes 5 and 6, the upper crossbar structure 24 of the engine bay bulkhead 25 mounted with these can be seen.

*0**** * . * .0000 * * *. *0 * S 0 * 0 * S *I*s 0. *S *. S * S -14 -

REFERENCE LIST

1 Longitudinal member 2 Longitudinal member 3 Reference position 4 Reference position Mounting shoe 6 Mounting shoe 7 Supporting member (vertical) 8 Supporting member (vertical) 9 Fitting hole Engine bay 11 Front end of a longitudinal member 12 Front end of a longitudinal member 13 Reference position of the lamp housing 14 Mounting plate for the lamp housing Lower crossbar structure 16 Front section structural member 17 Mounting retainer for a front trim 18 Wing retainer 19 Wing retainer Front wing 21 Front wing b S 22 Pre-assembled assembly 23 Tool plate S. *a * 24 Upper crossbar structure Engine bay bulkhead *5sS * . 26 Bonnet lock 27 Crossbar for front trim -15 - 28 Reference position of a wing retainer 29 Reference position of a wing retainer Installation unit 31 Crashbox 32 Crashbox 33 Circle 34 Circle Screw connection 36 Fixing opening for front wing A Direction arrow S* .* * S

S

* S. S SS * S S. *. *S S * . S... * . S. *w S. ** SS *