Abstract:
A vehicle subassembly includes a cooling cassette provided with at least one cassette element and a frame provided with at least one frame element which cooperates with the cassette element to fix the cassette to the frame. A thrust force applied to a face of the cassette that faces toward the front when mounted in the vehicle causes the cassette element to separate from the frame element.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to subassemblies for automobile vehicles including a cooling cassette and a support frame for the cassette.  
           [0003]    2. Description of the Prior Art  
           [0004]    Subassemblies for automobile vehicles including a cooling cassette supporting a motorized fan unit and a frame supporting the cassette are known in the art. The subassembly constitutes what is sometimes referred to as the technical front bulkhead of the vehicle. At present, the cassette is generally fixed to the frame by means of positive fasteners such as screws. This has drawbacks, however. If the vehicle suffers a frontal impact (such as a standard DANNER impact), causing pressure to be applied to the cooling cassette, the subassembly often fractures, damaging the cassette and the frame.  
           [0005]    One object of the invention is to provide a subassembly of the above kind which improves the chances of the cassette and/or the frame remaining undamaged if the vehicle suffers a frontal impact.  
         SUMMARY OF THE INVENTION  
         [0006]    To achieve the above object, the invention provides a vehicle subassembly including a cooling cassette provided with at least one cassette element and a frame provided with at least one frame element adapted to cooperate with the cassette element to fix the cassette to the frame, which elements are adapted so that a thrust force applied to a face of the cassette that faces toward the front when mounted in the vehicle causes the cassette element to separate from the frame element.  
           [0007]    Accordingly, in many circumstances, if the impact applies a force toward the rear on the cassette, it separates the cassette from the frame without damaging either of them. It is therefore possible either to refit the cassette to the frame or to replace only the cassette or only the frame with an identical component.  
           [0008]    The subassembly according to the invention can further have at least one of the following features:  
           [0009]    it includes an elastomer stud adapted to be interposed between the cassette element and the frame element;  
           [0010]    the cassette element is adapted to come into contact with the frame element to fix the cassette to the frame;  
           [0011]    one of the two elements of the pair consisting of the cassette element and the frame element is conformed as a male part and the other element of that pair is conformed as a female part adapted to receive the male part;  
           [0012]    the cassette element is conformed as a male part;  
           [0013]    one of the two elements of the pair consisting of the cassette element and the frame element is conformed as a lug and the other element of that pair is conformed to retain the lug with a clipping action;  
           [0014]    the cassette element is conformed as a lug;  
           [0015]    it includes a rib projecting from the face of the cassette that faces toward the front when mounted in the vehicle;  
           [0016]    it includes a motorized fan unit fixed to the cassette, the cassette having a raised portion projecting from the face of the cassette that faces toward the front when mounted in the vehicle and projecting farther toward the front than the motorized fan unit.  
           [0017]    The invention also provides a vehicle including a cooling cassette provided with at least one cassette element and a frame provided with at least one frame element cooperating with the cassette element to fix the cassette to the frame, which elements are adapted so that a thrust force applied to a face of the cassette that faces toward the front when mounted in the vehicle causes the cassette element to separate from the frame element.  
           [0018]    Other features and advantages of the invention will become more apparent in the course of the following description of a preferred embodiment, which description is given by way of non-limiting example and with reference to the accompanying drawing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0019]    [0019]FIG. 1 is an exploded perspective view of a preferred embodiment of a subassembly in accordance with the invention without the motorized fan unit.  
         [0020]    [0020]FIG. 2 is a view in cross section of the frame and the cassette of the subassembly shown in FIG. 1, at the location of a pair of fasteners.  
         [0021]    [0021]FIG. 3 is a view in horizontal section of the subassembly shown in FIG. 1 taken along the line III-III. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]    FIGS.  1  to  3  show a preferred embodiment of a subassembly in accordance with the invention.  
         [0023]    The subassembly  2  comprises a cooling cassette  4 , a support frame  6  and a motorized fan unit  8 .  
         [0024]    The cassette  4  is thin and generally rectangular. It has in the vicinity of its center a circular opening  10  adapted to receive the motorized fan unit  8 . The cassette  4  also has various raised and recessed portions adapted to receive items that are known in the art and that are not described in detail here. The cassette  4  is vertical when fixed to the vehicle. In this position, the longitudinal sides  12  of the rectangle are horizontal and transverse to the direction of movement of the vehicle. The short sides  14  of the rectangle are vertical.  
         [0025]    The cassette has lugs  20 , of which there are eight in this example, for fixing it to the frame  6 . Each of the four edges  12 ,  14  of the cassette carries two of the eight lugs. The lugs extend from the edge of the cassette toward the front, projecting from the face  22  of the cassette that faces toward the front when fixed to the vehicle. Each lug has a generally flat shape and is essentially parallel to the edge that carries it. It also has a boss  24  on one side of the lug, near its free end, for retaining the lug in a fixing orifice described below.  
         [0026]    The frame  6  includes a generally rectangular housing  26  which receives the cassette  4 . The frame also has two horizontal longitudinal sides and two vertical short sides. The top left-hand and right-hand corners of the frame are extended laterally by two extension  28 . The ends of the extensions  28  are adapted to be fixed to the inner wings of the vehicle. Also, the frame  26  has half way up its vertical sides locations  30  for fixing the frame to two longitudinal members of the vehicle.  
         [0027]    The frame includes the same number of tabs  32  as there are lugs  20 , extending from the four sides of the frame into the opening intended to receive the cassette. Each tab  32  is vertical and has a generally flat shape with a rectangular contour. It has an orifice  34  at its center. In this example, the orifice is occupied by an elastomer material stud or shoe  38  having an opening at its center and an annular groove at its periphery adapted to envelop the edges of the opening  34  in the tab to receive and locate the shoe in the opening. The opening  34  in each tab  32  and the central opening in the corresponding shoe are elongate. The opening is adapted to receive one of the lugs  20 . The lugs  20  therefore constitute male parts and the tabs  32  constitute respective female parts which receive them from behind. Consequently, the cassette  4  is mounted on the frame  6  by inserting it into the opening  26  of the frame from behind.  
         [0028]    When the cassette is correctly positioned in the opening, the eight lugs  20  are engaged in the openings  8  in the shoes and are received in the respective tabs. When the lugs are inserted into the shoes  38 , the boss  24  of each lug defines a sticking point that has to be overcome before the lug is properly received in the tab. This sticking point limits the risk of unintentional withdrawal of the lug from the tab on rearward movement of the cassette out of the frame. The lugs are retained firmly in the tabs by the compression force applied to the lugs by the elastomer material shoes. Also, the bosses  24  on the lugs have an additional retaining effect. The cassette is therefore properly fixed into the frame that supports it.  
         [0029]    The cassette  4  carries the motorized fan unit  8 , which is received in its opening  10 , as shown in FIG. 3. The cassette has a raised portion  40 , which takes the form of a vertical rib in this example, projecting from the face  22  of the cassette that faces toward the front when fitted to the vehicle. The rib extends farther toward the front than the motorized fan unit  8 . Accordingly, if the vehicle suffers a frontal impact, for example at a low speed, generating temporary or permanent deformation of the bumper beam  42 , in many circumstances the bumper beam  42  will strike the rib  40  on the cassette before reaching the motorized fan unit. This impact causes the cassette to move toward the rear relative to the frame, extracting the lugs from the tabs. The impact therefore causes localized or total demounting of the cassette from the frame. In many cases neither the cassette nor the frame will be damaged. In particular, the fastenings formed by the lugs and the tabs are protected from any damage. It is therefore possible either to refit the cassette directly to the frame or to replace either the cassette or the frame with a new component. This reduces the cost of repair.  
         [0030]    Moreover, the subassembly in accordance with the invention facilitates standardizing the fixing of the cooling cassettes to the frames.  
         [0031]    The function of the shoes  38  is essentially to damp vibration. In a different embodiment, these shoes could be dispensed with and the lugs clipped directly into the tabs by virtue of the bosses  24  and the ends of the lugs coming into elastic bearing engagement against an edge of the orifice in each tab.  
         [0032]    The invention is particularly suitable for the circumstances of the kind of impact usually referred to as DANNER impact.  
         [0033]    Of course, many modifications can be made to the invention without departing from the scope of the invention.