Abstract:
Describe is a front wall module for a motor vehicle. The front wall module forms at least one area of a front wall that defines the passenger compartment of a motor vehicle. The front wall module contains functional units, such as the fan for ventilating the passenger compartment or the like. The front wall module has a capping piece that is connected to two longitudinal beams of the motor vehicle.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a front wall module for a motor vehicle as well as to a motor vehicle. 
   BACKGROUND OF THE INVENTION 
   With the manufacture of motor vehicles it is usual for the vehicle to comprise a self-supporting vehicle body, wherein the vehicle body, for delimiting the vehicle interior seen in the direction of travel, comprises a so-called “front wall” which e.g. is designed as a sheet steel piece belonging to the vehicle body. Such a sheet steel piece at its upper end is usually connected to a hollow beam (a so-called “window bow”) which is arranged above the front wall and which represents the lower connection surface for a windscreen of the motor vehicle. 
   This usual constructional shape has the advantage that a vehicle body may be premanufactured in an essentially fluid-tight manner and with a rigid structure. However it is of a disadvantage that the functional units in the region of the front wall, such as a fan for interior ventilation, parts of the vehicles electronics, etc. need to be individually assembled on the front wall in a very expensive manner. Due to this, extensive costs result during manufacture and the exchange of individual functional units is likewise very cost-intensive. 
   The British patent GB 2329363A specifies a front wall module for a motor vehicle. This forms the upper region of a front wall delimiting the interior of the motor vehicle. This front wall module in its inside, as a functional unit, comprises a fan for interior ventilation. 
   This known front wall module specifically has the advantage that it reduces the manufacturing expense, since functional units which are already modularly premanufactured may be incorporated into the motor vehicle. The disadvantage however is the fact that this concept falls short of the high safety demands. Furthermore on assembly, the bringing of the known front wall module through the vehicle interior into the region of the front wall can become somewhat of a problem. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a front wall module for motor vehicle. The present invention allows a motor vehicle to be manufactured and repaired with little expense, while the highest safety demands are met. 
   An inexpensive and secure concept is made available by way of the fact that a front wall module according to the preamble additionally comprises a yoke beam which may be connected to two longitudinal beams of the motor vehicle. 
   Deviating from the previously hardened vehicle concepts, an additional beam is integrated into the front wall module, which significantly increases the stiffness of the vehicle body in the region of the front wall. By way of this, part of the stability task of the previously usual hollow beam may be assumed in the upper as well as lower region of the front wall, so that a greater design freedom for the vehicle as a whole arises. 
   By way of this it is also possible, also with smaller vehicle dimensions, to obtain an as large as possible vehicle interior, which may be fashioned in a practically infinite manner. By way of the attachment of the yoke beam according to the invention to the (usually two) longitudinal beams which run in the longitudinal direction on the outer sides of the vehicle body, an even better passive safety of the motor vehicle is ensured. This on the one hand relates to the side crash behaviour, since the lateral deformability of the motor vehicle (and thus the pressing together of the motor vehicle interior from the side) is reduced due to the yoke beam. Furthermore the frontal crash behaviour is improved, since a penetration of the front wall module into the interior of the motor vehicle is prevented. 
   Furthermore, the yoke beam according to the invention contributes to the torsional stiffness of the motor vehicle about the longitudinal axis, and the travelling comfort and long-term stability of the vehicle body is further improved on account of this. 
   A particularly advantageous embodiment envisages the yoke beam being connectable to the remaining front wall module with a non-positive fit, e.g. via screws. For this, the yoke beam may be manufactured in a simple manner of a very stable material (e.g. a profiled sheet steel) and may be e.g. screwed to the remaining front wall module in a simple manner. This is particularly easily possible on the outer side of the front wall module, thus towards the motor space with front motor vehicles. By way of a possible separation of the yoke beam and the remaining front wall module it is also possible, for various series of vehicles, to couple in each case only the different yoke beams but otherwise unchanged equal front wall modules to one another. By way of the non-positive connection (preferably screw connection, additionally a bonding may be useful under certain circumstances for sealing), it furthermore becomes possible to achieve a simple separability in the case of repair without e.g. having to worry about damage to the paintwork as occurs on welding (with subsequent corrosion problems). It is of course however also possible to envisage any positive-fit or material-fit joining method (in particular bonding). 
   A further advantageous embodiment envisages the yoke beam being able to be connected to the longitudinal beams of the motor vehicle with a non-positive fit, preferably via screws. This is advantageous with the manufacture of the vehicle as well as on exchange of the front wall module. It is possible in a relatively late stage of the motor vehicle production for the front wall module to be completely (and specifically “from above”) inserted from the region of the motor space (with front motors). Here, welding is not necessary and vehicle paintwork is not damaged. At the same time it is particularly favourable that the longitudinal beams of the motor vehicle offer an attachment surface for the yoke beam. Under certain circumstances it is possible to weld suitable attachments on the longitudinal beams during the prior vehicle body manufacture, which offer an additional stability in the connection region. By way of such attachments it furthermore becomes easily possible, e.g. with front wall modules with a uniform yoke beam size, to accommodate one and the same front wall module (with identical yoke beams) in various sized vehicle bodies by way of varying the attachments. It is of course also possible here apart from the non-positive fit connection indicated as being advantageous here, to provide positive-fit or material fit connections, in particular bonding. 
   A particularly advantageous further embodiment envisages several functional units being accommodated in the front wall module. This e.g. may be one (or several) fans for interior ventilation, an interior air filter, a heating body for interior ventilation, an evaporator of an air-conditioning installation, an air channel system, a control unit for the electronic control of elements in the interior of the motor vehicle, a cable loom connected to the control unit, an airbag or likewise. 
   It thus becomes possible to connect these individual functional units to one another within the front wall module already during premanufacture of the vehicle. A particularly advantageous further embodiment envisages the front wall module comprising so-called “collectors” which are connected to the cable loom or to the control unit. These collectors may serve as electrical interfaces between the front wall module and the remaining motor vehicle (thus e.g. with elements of the motor electronics, door locking, lighting etc.). These collectors may e.g. be attached to the lateral outer sides of the front wall module. By way of this a particularly easy connection for standardised data buses to the collectors becomes possible, and by way of a simple exchange of the collectors, an electrical or electronic connection of the front wall module to various model series becomes possible. 
   A further, particularly advantageous further embodiment envisages the front wall module having a cavity construction with an outer casing (covering), wherein the outer casing is formed by a front wall inner part which is directed towards the motor vehicle interior, and a front wall outer part which is distant to the motor vehicle interior. Due to this it becomes possible for the individual functional units to be accommodated in the inside of the front wall module and on the one hand to be protected from damp and moisture influences etc., and on the other hand the passive safety is increased in that these functional units do not represent any danger to the vehicle passengers in the case of a collision. Within the concept of a simple manufacturability or repair ability, one may provide a “layered construction”, wherein individual functional units as “sub-modules” are layered between the front wall outer part and inner part. With such a shell-like cockpit construction the individual functional units such as an air conditioning installation unit may be incorporated into the front wall module already premanufactured. In this manner, with special fittings to the motor vehicle one may also simply realise different customer wishes during manufacture, or these may be retrofitted at a later point in time. 
   Further advantageous embodiments furthermore envisage the front wall module itself contributing to the stiffening and improvement of the safety of the vehicle. Thus e.g. the front wall outer part and/or the front wall inner part may be connected as a hybrid part of metal with plastic connected thereto (e.g. in a honeycomb construction manner). A simple manufacturability is provided on account of this, a separation of the material on reuse is simplified and the manufacturing costs are low. Furthermore it is also possible to provide further supporting parts e.g. a hollow beam in the upper region of the front wall module which here assumes the function of a “window bow”. By way of the fact that in this case the shell of the motor vehicle does not need to contain an already previously fixed window bow, an even simpler assembly of the front wall module is possible (“from above”, thus not necessarily from the vehicle interior). 
   At the same time it is becomes possible to already accommodate a “water box” for collecting fluid running down from the motor vehicle windscreen, on the front wall module, which e.g. may already contain windscreen wiper motors etc. 
   The front wall module according to the invention may be applied in various vehicle types. For obtaining a particularly large space for the feet for the vehicle passengers, it is useful to attach the front wall module for filling out in the upper region of the front wall, wherein a sheet steel composite which is profiled or provided with cavities is provided only in the lower front wall region. In particular, for future “drive by wire” applications it is useful to provide a receiver for a steering column for controlling the motor vehicle on the inner front wall part of the front wall module. By way of this, the steering unit is de facto separated from the shell. Alone by way of the provision of different front wall modules during manufacture, one may realise a right-hand or left-hand drive vehicle. A later retrofitting is also easily possible. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention is explained by way of several Figures. There are shown in: 
       FIGS. 1   a  to  1   d  several sections through a front wall module according to the invention, in a motor vehicle, 
       FIG. 2  a perspective front view of a part of a motor vehicle according to the invention, 
       FIG. 3  an exploded drawing of the individual parts of the front wall module according to the invention, in a vehicle, 
       FIGS. 4   a  to  4   r  individual parts of a front wall module according to the invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1  a shows a cross section through a motor vehicle, with a front wall module according to the invention. A lateral cross section in the region of the driver seat is shown. 
   In the following the front wall module  1  is dealt with in more detail. 
   This forms the upper region of a motor vehicle front wall which delimits the motor vehicle interior in the travelling direction. A front [wind] screen  22  borders the front wall module  1  to the top, and towards the bottom there connects a vehicle floor  2   c  as well as a reinforcement of the vehicle floor  2   d  which belong to a shell of the motor vehicle and form the lower region of the front wall of the vehicle. The front wall module forms the upper region. The front wall module at its side which is directed towards a motor space and is distant to the motor vehicle interior comprises a yoke beam  20  which by way of screw connections connects two longitudinal beams of the motor vehicle running on the longitudinal sides of the vehicle to one another. The yoke beam  20  is connected with a non-positive fit (screwed) to the remaining front wall module. The remaining front wall module contains a front wall outer part  21  to which the yoke beam  20  is screwed. 
   The front wall outer part  21  as well as a front wall inner part  6  are connected to one another and form a cavity construction with an outer casing, wherein the outer casing is formed by the inner front wall part  6  directed towards the motor vehicle interior, and the outer front wall part  21  distant to the motor vehicle interior. 
   Several functional units are accommodated within the cavity, and their function and arrangement will be dealt with in more detail later. Here it is the case e.g. of a filter  15  in a filter box  16 , a fan  10 , a cable loom  17 , a defroster channel  8 , an air channel system  7 . The fan  10  is arranged in a layer-like construction between an air-conditioning installation front wall  9  and an air-conditioning installation rear wall  11  which will likewise be described in more detail later. To the motor vehicle interior, a steering column  5  via which the motor vehicle may be electrically controlled, connects to the front wall inner part  6 . Alternatively or additionally it is of course also possible to provide a hydraulic or mechanical steering force transmission. 
   A water box (chamber)  19  is attached to the upper side of the front wall module and this water box likewise belongs to the front wall module and collects liquid running down from the front [wind]screen  22  of the motor vehicle. The water box  19  as well as the front wall outer part  21  in the upper region of the front wall module, thus in the connection region to the front [wind]screen  22  form a hollow beam  24  for stabilising the front wall module in the region of the front windscreen of the motor vehicle. In this manner one realises an upper transverse beam, a so-called “window bow”. It is however also possible for the vehicle body in this region to envisage an additional transverse beam for the connection of both A-columns. 
   The front wall module  1  is screwed to the vehicle body  2  of the motor vehicle. Apart from a lateral screwing in the region of the A-columns, amongst other things a screwing in the region  25  towards the vehicle floor is also given. 
     FIG. 1   b  shows a cross section through a motor vehicle according to the invention, which is parallel to that in  FIG. 1   a.  The same reference numerals as drawn in  FIG. 1   a  here show the same elements so that a description is not made again to save repetition. A control unit  3  is shown on the lower side of the front wall module in  FIG. 1   b  and this unit is electrically connected to the cable loom  17 . 
     FIG. 1   c  again shows a parallel section to the  FIGS. 1   a  and  1   b.  A section in the region of the front passenger seat is shown. On the upper side of the front wall inner part  6  there is attached an airbag  4  which is covered towards the motor vehicle interior by way of a dashboard which is not shown. 
     FIG. 1   d  shows a horizontal section through the front wall module according to the invention, at the height of the steering column. 
   Here one may recognise particularly well that the front wall module according to the invention, advancing from the left to the right, has a layered construction. 
   Beginning from the left one may firstly recognise a yoke beam  20 . This, as may already be seen by way of viewing together the  FIGS. 1   a  to  1   c,  has an arch-like course (with the highest point in the middle of the vehicle). In cross section, the yoke beam  20  is essentially “U” shaped and comprises reinforcement webs which are distanced to one another. The yoke beam  20  is screwed to the front wall outer part  21 . This front wall outer part  21  on its outer side has a metal skin which on the inner side is reinforced by a honey-comb-like plastic structure. An insulation  18  connects to this. Proceeding to the right then a filter box  16  with a filter  15  contained therein (in each case on each vehicle side) is attached. Subsequently, but not seen here, a cable loom (indicated at  17  in  FIG. 1   c ) is arranged which is connected to collectors  14  on the left and on the right vehicle side. These collectors represent electrical interfaces between the front wall module and the remaining vehicle. They serve e.g. for the attachment to the electronics of the motor, to a door locking, to a lighting etc. Also a connection, preferably a screwing of the front wall module to the A-columns of the motor vehicle takes place in the region of these collectors. The collectors may be matched in their size or interface definition to individual vehicle types. Thus various collectors may be combined for one and the same front wall outer part. 
   In  FIG. 1   d,  proceeding further to the right, as a next location, the air-conditioning installation rear wall  11  is shown, which forms a cavity with the air-conditioning installation front wall  9  which is incorporated further to the right. A blower  10 , an evaporator for the air-conditioning installation  12  as well as a heating body  13  are attached in this cavity on each vehicle side. On the right, connecting to the air-conditioning installation front wall  9 , are defroster channels  8  (see  FIG. 1   c ) as well as an air channel system  7  for air distribution in the inner space of the motor vehicle. Connecting to this is a front wall inner part  7  on which the steering column  5  is fastened. In  FIG. 3  one may see that the front wall inner part  6  is provided with an outer skin towards the motor vehicle interior, in which discharge [piece]  27 , a middle console  28  and a steering column covering  29  are assembled. 
   It is to be mentioned that by way of the intermediate connection of connection pieces on the front wall module according to the invention it becomes possible to adapt the front wall module according to the invention to different vehicle body widths. 
     FIG. 2  shows perspectively views of an assembled front wall module on a vehicle body  2  of a motor vehicle. 
   The yoke beam  20  is screwed to the front wall part  21  of the front wall module. The yoke beam  20  is again screwed to a longitudinal beam  2   a  of the motor vehicle. For reasons of clarity, in  FIG. 2  only a single longitudinal beam is shown, a longitudinal beam parallel to this is also located on the right vehicle side according to  FIG. 2 , but however is not shown there. The longitudinal beam  2   a  on its upper side comprises an adapter  2   b  which belongs to the longitudinal beam and which serves for the simple joining to the yoke beam  20 . Screw holes  27  are likewise easily recognised in  FIG. 2  which serve for the screwing of the front wall module to the region of the A-columns of a motor vehicle or to the region of the lower front wall formed by the vehicle body parts  2   c  and  2   d.    
   In the following, the individual components of the subject matters according to the invention are dealt with taking reference to the exploded drawing according to  FIG. 3 , which are specified in  FIGS. 4   a  to  4   r.    
   In  FIG. 3  there is shown a vehicle body  2  with a vehicle floor  2   c  as well as a reinforcement of the vehicle floor  2   d  and a longitudinal beam  2   a  projecting to the front. A more detailed view with regard to this is to be deduced from  FIG. 4   a  (in  FIG. 4   a  in particular also the adapter  2   b  belonging to the longitudinal beam  2   a  is shown, which later may be screwed to the yoke beam  20 ). The upper front wall region which is open in  FIG. 4   a  (indicated in  FIG. 4   a  by the circled reference numeral  33 ) is closed by the front wall module  1 . This front wall module  1  whilst forming the front wall, on its side distant to the motor vehicle interior comprises a front wall outer part  21  (see  FIG. 3 ). The front wall outer part  21  is constructed as a hybrid part. It consists of a sheet metal wall  21   a  which is attached on the side distant to the vehicle inner space, and of a plastic part  21   b  with cross-struts or a honey-comb-like structure, which is arranged towards the vehicle interior. Details of the front wall outer part are to be seen in  FIGS. 4   b  and  4   c,  wherein the screw holes  27  may also be recognised. At the same time,  FIG. 4   b  shows a view of the front wall outer part  21  from the vehicle interior,  FIG. 4   c  shows a view from the opposite direction. A reinforcement in the form of a yoke beam  20  with an essentially U-shaped cross section is screwed to that side of the front wall outer part  21  which is distant to the motor vehicle interior. This is screwed to the longitudinal beams  2   a  (see also  FIG. 4   d  with regard to the details of the yoke beam). A water box  19  is screwed to the front wall outer part  21 , which contains wiper motors  30  (see  FIG. 4   e  for the water box). 
   As a further layering, towards the vehicle interior, an insulation piece  18  for sound and thermal insulation is provided which is joined into the front wall outer part (see  FIG. 4   f ) Proceeding from this further towards the vehicle interior are filter boxes  16  with filters  15  contained therein (see  FIGS. 4   h  and  4   i ) for each vehicle side. 
   A cable loom  17  (see  FIG. 4   g ) is also connected, which with its lateral run-outs on the right side and on the left side in the region of the A-columns of the vehicle body  2  is connected to the collectors  14  (see  FIG. 4   j,  here the collector on the right side is shown). As a next layer, a sub-module for the air-conditioning is connected. An air-conditioning installation rear wall  11  (see  FIG. 4   k ) as well as an air-conditioning front wall  9  (see  FIG. 4   o ) include various parts for air-conditioning the vehicle inner space. These are (separated in each case on the left and right side for each vehicle half): an evaporator  12  (see  FIG. 41 ), a heating body  13  (see  FIG. 4   m ) as well as a fan  10  (see  FIG. 4   n ). Due to the grouping together of all air-conditioning apparatus into a single sub module, this may be very easily exchanged or may be realised individually depending on the desires of the customer (alternatives, no air-conditioning installation, air-conditioning installation, air-conditioning automatic [device]). Then, defroster channels  8  are connected on the left and right side to the air-conditioning installation front wall  9  as well as an air channel system  7  (see  FIG. 4   p ) for air distribution in the inner space. Finally, the front wall inner part  6  is joined which is connected to the front wall outer part  21  and thus encompasses all those components which have just been mentioned. The inner and outer parts of the front wall may at the same time consists of practically any material, preferably plastics or sheet metal [pieces]. 
   On the left and right side, reinforcement profiles  31  for accommodating the steering column  5  are attached to the front wall inner part. A control unit  3  may be attached below the front wall module  1 . On the side of the interior, an outer skin  26  for the trim connects to the front wall inner part  6  (see also  FIG. 4   q ). This comprises a discharge  27 , a middle console  28  as well as a covering [panelling]  29  of the steering column  5 . 
   Then a steering wheel  32  connects to the steering column  5  (see also  FIG. 4   r ).