Abstract:
A wall unit forms a part of the outer wall of a vehicle cab. In order to simplify the accommodation of electrical components in the vehicle cab and to reduce the cost of wiring, the wall unit is configured as a pre-assembled module, which includes a support structure on which electrical components, such as vehicle function controllers, fuses and relays, are fastened. The electrical components are at least partially covered by enclosure elements. The electrical components can be electrically connected with corresponding vehicle component groups via connectors.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a wall unit which forms one part of the exterior wall of a vehicle cab.  
         BACKGROUND OF THE INVENTION  
         [0002]    Vehicle cabs generally contain a cab frame to which, among other items, wall components, doors, flaps and windows are fastened. Cabs for industrial or agricultural vehicles, frequently include a rollover protection frame that is fastened to a rigid floor plate to whose rear side regions fenders are fastened. Such cabs normally pre-assembled completely, in that all necessary wall components, doors and windows are installed between the posts of the cab frame, so that the interior of the cab is enclosed on all sides. Furthermore, the operator&#39;s seat, as well as all operating elements and fittings, are installed. During the final assembly of the vehicle the complete pre-assembled cab is mounted on the vehicle body. Following this the necessary mechanical, electrical and hydraulic connections between the vehicle and the cab are established.  
           [0003]    Many electrical components that are not actuated constantly by the operator, such as fuses, relays and controllers, that perform various vehicle control tasks are accommodated at various locations within the cab. The positioning of these components is normally difficult, since the interior of the cab should be cramped as little as possible and because many regions of the cab are already occupied by various components. With the increasing automation and numbers of associated electrical control elements, it becomes ever more difficult to find appropriate room for the electrical components. Since the electrical components are scattered about the cab a costly wiring process is required that reduces the ability to scan, makes maintenance operations more difficult and is accompanied by safety risks.  
         SUMMARY OF THE INVENTION  
         [0004]    An object of the present invention is to provide a wall unit which simply accommodates electrical components.  
           [0005]    Another object of the present invention is to provide a wall unit which reduces wiring costs.  
           [0006]    Another object of the present invention is to provide a wall unit for which electrical components can be easily scanned for maintenance operations.  
           [0007]    These and other objects are achieved by the present wall unit, which is a pre-assembled module and forms a part of the outer wall of a vehicle cab. The module includes a support structure to which electrical control components are fastened, which are covered at least in part by wall elements. The electrical components are, for example, controllers for control of the vehicle steering, fuses and relays. Furthermore, the electrical components may be connected and disconnected with corresponding vehicle component groups via corresponding connectors.  
           [0008]    The pre-assembled wall unit can therefore close an opening in the cab wall. The electrical components can be fastened to the support structure on the inner or outer side of the cab. The connectors of the wall unit can engage corresponding connectors configured as multiple connectors for the cab wiring harness, engine wiring harness and gearbox wiring harness. An appropriate sealing arrangement on the outer contour of the wall unit is provided to seal the cab against undesirable environmental hazards.  
           [0009]    The wall unit can combine in a common space the electrical components, in particular the controllers, that were previously scatted about the vehicle cab. The wall unit can be a pre-assembled module that can be assembled completely, independent of the remaining cab, and that can be tested for proper operation. For the testing, the connectors of the module can be connected with connectors of a test rig. The assembly of the electrical components need therefore not be performed on the cab assembly line, hence the time of the process on that assembly line can be reduced and the testing or a search for errors can be simplified. The combined and easily scanned arrangement of the electrical components and their wiring simplifies maintenance and repair operations. Errors that can be attributed to a poorly scanned arrangement of the components and that carry safety risks, can be avoided.  
           [0010]    Preferably, the wall unit is mounted at the rear of the vehicle, for example, is located between the rear wheel fenders. Thus, the rear side of the cab underneath the rear window is initially open and is closed by the installation of the wall unit.  
           [0011]    Preferably, support structure for the wall unit is arranged between the two rear wheel fenders of the vehicle and has an outer contour which conforms to the structure of the fenders, so that no further wall components are required.  
           [0012]    If filter housings are arranged on the inner side of the fenders, as is described in EP-A-0 438 076, the side edges of the support structure will conform to the contour of these filter housings, in order to create a sealed transition. At its upper edge the support structure engages a window sealing arrangement, which supports the rear window and seals it.  
           [0013]    Preferably, wings in the upper region of the support structure project outwardly on both sides. These wings close areas of the cab located between each of the vehicle fenders or filter housings on the one hand and the rear window of the cab on the other hand. Thus, the rear region of the cab can be completely closed by the wall unit and the rear window of the cab.  
           [0014]    Preferably, the wall unit is configured in a cassette-like or drawer-like form so that it can be inserted over skids or the like into the opening of the vehicle cab, if necessary by means of an assembly robot. For this purpose, the support structure is provided with an essentially vertical cab side wall and an essentially horizontal cab floor plate. Thereby, alongside a cab side wall, a part of the cab floor is integrated into the support structure.  
           [0015]    Preferably, the support structure includes openings for the routing of lines and wiring harnesses in order to simplify their routing. These openings can be closed by the assembly of the connectors or the electrical components, or by appropriate sealing elements.  
           [0016]    Bordering walls project vertically from the plane of the support structure and are integrated into the support structure, through which housing-like chambers are formed to accommodate the electrical components. The bordering walls provide stiffening of the support structure. One or more of the chambers formed by the bordering walls located on the outside of the support structure can be closed by a cover which forms part of the outer enclosure and protects the electrical components against harmful environmental hazards. The interior side of the support structure is covered by a cab enclosure that protects the interior electrical components on the one hand and on the other hand complies with the interior equipment.  
           [0017]    Preferably, the cab enclosure is configured as a cover which projects to the side over the support structure for a cab configuration in which air filter housings are integrated into the cab wall and which are provided with ventilation ducts open to the interior of the cab. With the projecting regions the cab enclosure covers the ventilation ducts and includes air flow slots through which air can be drawn from the interior of the cab for a ventilation circuit.  
           [0018]    Preferably, a fuse panel is supported in bearings on the support structure so as to pivot in the form of a service flap, so that it can be pivoted away from the support structure. Vehicle fuses, relays and the like can be arranged on one side or on both sides of the plate-shaped fuse panel. The pivoted fuse panel simplifies the access to the components arranged on the fuse panel and to the components located behind the fuse panel. The fuse panel is preferably located on the inside of the cab structure and is covered by an element of the cab enclosure.  
           [0019]    The wall unit provides a place for the vehicle controllers. For their various applications, modern utility vehicles require multiple controllers. These can all be combined on the wall unit. Such controllers may include, for example, an engine controller for the control of the main drive engine, a gearbox controller for the control of the gearbox, a lifting arrangement controller for the control of the attachment arrangement, an implement controller for the control of one or more attached implements and further controllers that are provided for further control functions. The controllers are accommodated in metal housings, which seal the electronics hermetically against environmental hazards and that contain sealed outlet openings for the electrical supply and control lines that are combined into wiring harnesses.  
           [0020]    Preferably the controllers are accommodated in chambers in the support structure fitted specifically for them. Each chamber can be closed, for example, individually by a cover. However it is advantageous to close several chambers with a single cover, in order to simplify the assembly operation and to reduce sealing problems. The enclosure with covers is particularly appropriate for the outside of the cab. A save space, two or more controllers may be arranged one above the other in a single chamber.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a rear perspective view of a tractor cab which includes a pre-assembled wall unit according to the invention; and  
         [0022]    [0022]FIG. 2 is an interior view of a wall unit according to the invention; and  
         [0023]    [0023]FIG. 3 is an exterior view of the wall unit according to the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    [0024]FIG. 1 shows a complete pre-assembled tractor cab unit  10  which can be mounted on and connected to a vehicle body during the final assembly. The tractor cab  10  includes essentially of a four-post rollover frame to whose four corner posts  12 ,  14 ,  16  enclosure components are fastened, that engage, among other items, the doors and cab windows. The tractor cab  10  has a cab roof  18  and a floor plate (not shown). In its rear region a fender  20  is fastened to each side. On the inner side each fender  20  is followed by an air filter housing  22 , of which only the left one is shown. These air filter housings  22  are connected with air channels extending vertically in the region of the rear corner posts  14 ,  16  and are accessible from the outside through rectangular covers as was described in EP-A-0 438 076.  
         [0025]    On the rear side of the tractor cab  10  a wall unit  24  is mounted. Wall unit  24  is a pre-assembled module which can be formed independent of the remaining tractor cab  10  and which includes a support structure  26 . The support structure  26  is essentially L-shaped and is provided with a cab side wall  28  extending vertically and a cab floor plate  30  extending horizontally formed onto it at the bottom. The support structure  26  has a bulge  32  extending into the interior of the cab that contains a free space for, among other items, a hydraulic pump (not shown) mounted on the vehicle differential housing. On each side of the upper region of the cab side wall  28  a wing  34  projects outward. The outside contour of the support structure  26  conforms to an opening in the rear side of the tractor cab  10  in such a way that the side edges of the cab side wall  28  are in contact with the air filter housings  22 , the wings  34  enclose a free space between the air filter housings  22  and the rear window  36 , and the cab floor plate  30  is in contact with the remaining floor plate of the tractor cab  10  and is a part of the cab floor. Conventional sealing elements (not shown) are used to seal the wall unit  24  against the remaining tractor cab  10 .  
         [0026]    Sliding rails (not shown) are provided in the region of the cab floor for engaging skids (not shown) positioned on the cab floor plate  30  of the support structure  26 . This permits a simple assembly of the wall unit  24 , that can be set upon the sliding rails with their skids and then slid forward into the tractor cab  10  until the opening in the rear of the cab is closed by the support structure  26 .  
         [0027]    As best seen in FIG. 2, bordering walls  38 ,  40  are formed on the inner side of the wall unit  24 . The walls  38 ,  40  project perpendicularly from the cab side wall  28  of the support structure  26  and provide stiffening for the support structure  26 , and border a chamber in which a fuse panel  42  is arranged.  
         [0028]    A fuse panel  42  is supported in bearings on the bordering walls  40  at the side in its lower region over a horizontally extending hinge axis (not shown in any further detail), and may be pivoted forward as a flap from the position shown, so that its upper edge moves forward in the direction of the arrow A and opens an access to the rear side of the panel and to the space behind the fuse panel  42 . On the forward side of the panel and, if necessary, on the rear side as well, fuses, relays and other electrical components are arranged, each of which may be combined into pre-assembled component groups, which are provided with plug-in contacts, in order to be able to plug them into corresponding connectors fastened to the fuse panel  42 . These electrical components are connected over one or more wiring harnesses  44  with one or more connectors. The connectors can be connected with corresponding cab wiring harness connectors, engine wiring harness connectors, gearbox wiring harness connectors or other connectors, in order to establish connections to corresponding electrical component groups of the vehicle.  
         [0029]    Two controllers  48 ,  50  are mounted, one above the other, on the inner side of the support structure  26  of the wall unit  24  on both sides alongside the bulge  32 . These may be commercially available electronic control units, which typically have generally slab-shaped metal housings and which can perform different control functions of the vehicle. The electric lines  52  of the controllers  48 ,  50  are connected with connectors  54  that are inserted into openings  56  in the cab side wall  28  of the support structure  26 . These connectors  54  can be connected with a corresponding plurality of connectors  58 , which establish connections with the corresponding vehicle component groups (not shown).  
         [0030]    The inner side of the support structure with the fuse panel  42  and the controllers  48 ,  50  is covered by an upper enclosure element  59  and a lower enclosure element  60  whose shape and visual appearance conforms to the interior equipment of the cab. The enclosure elements  59 ,  60  can be assembled and disassembled in a simple manner and permit rapid access to the fuse panel  42  or the controllers  48 ,  50 . The enclosure elements  59 ,  60  project to the side beyond the cab side wall  28  of the support structure  26  and extends over ventilation outlet channels (not shown) of the air filter housing  22 . In its projecting regions  62  the upper enclosure element  59  contains air flow slots  63  which permit an air flow from the interior of the cab into the air filter housing  22 . On the rear side of the projecting regions  62 , not visible in FIG. 2, circulating air filter elements are fastened over the air flow slots  63 , such as, for example, by an applied adhesive.  
         [0031]    On the outside of the wall unit  24 , as best seen in FIG. 3, bordering walls  64  are also formed onto the cab side wall  28  of the support structure  26  projecting vertically. Walls  64  provide stiffening of the support structure  26  and border upon a chamber  66 . Chamber  66  receives two controllers  68 ,  70  which are arranged one above the other, and which are electrically connected with one of the aforementioned connectors  54 . The chamber  66  formed by the bordering walls  64  can be closed by a cover  72 , so that the controllers  68 ,  70  are protected against environmental hazards. Furthermore, the connectors  54  and  58  are protected by covers  74 , of which one is shown, which are fastened above the connectors  54  and  58 .  
         [0032]    Although the invention has been described in terms of only one embodiment, anyone skilled in the art will perceive many varied alternatives, modifications and variations in the light of the above description as well as the drawing, all of which fall under the present invention.