Patent Abstract:
An electronic module for a fan of an internal combustion engine in a motor vehicle comprising at least one deformable element ( 12, 28, 68 ), which when deformed can engage with a part ( 4 ) of the fan in a detachable manner, and at least one rigid projecting retaining element ( 24, 66 ), which can be inserted in a direction of insertion into a receptacle ( 26 ) or opening ( 38, 78 ) of a fan frame ( 4 ) before the deformable element ( 12, 28, 68 ) engages, wherein after the retaining element ( 24, 66 ) is inserted into the receptacle ( 26 ) or opening ( 38, 78 ), the electronic module ( 2 ) is movable with a single degree of freedom different from the direction of insertion in order to bring the deformable element ( 12, 28, 68 ) into engagement with the fan frame.

Full Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an electronic module for a fan of an internal combustion engine in a motor vehicle as well as a fan for cooling an internal combustion engine of a motor vehicle, with an electronic module for controlling the fan. 
     Newer fans for cooling internal combustion engines in motor vehicles are usually equipped with an electronic module for operating and controlling the fan. In this case, it is customary to use a standardized module in the form of an add-on piece, which is suited for several types of fans with different structural designs and which is fastened to the fan after installation of the fan or after installation of said fan in the motor vehicle. The electronic module is fastened to the fan in the intake air flow on a frame of the fan that is designated as the fan frame, which is fastened on its outer circumference in the motor vehicle and bears the fan drive and the rotatably mounted fan wheel in its center, whereby most of the time a plurality of self-cutting screws are used as fastening agents. However, this type of assembly requires an assembly tool in the form of a screwdriver or power screwdriver as well as a certain time commitment both for assembly as well as for any disassembly that may be necessary. 
     SUMMARY OF THE INVENTION 
     The electronic module in accordance with the invention and the fan in accordance with the invention in contrast offer the advantage that the deformable element attached to the electronic module can be engaged manually quickly and without auxiliary agents with the part of the fan serving as a mounting, thereby making time-saving assembly and any disassembly of the electronic module possible. 
     In comparison to mounting a deformable element on a part of the fan, preferably a fan frame being used as a mounting for the electronic module, the advantage of mounting on the electronic module is also that expenses required in the manufacturing of a fan frame for adaptation, adjustment, sampling and testing of the deformable element are eliminated and thereby both the fabrication expense as well as the tool fabrication times in the manufacturing of fan frames are clearly reduced, because the deformable element, whose production normally incurs greater expense, is integrated into the geometrically standardized component, namely into the electronic module, while the fan frame or another part of the motor vehicle being used for fastening the electronic module for engagement of the deformable element only has to be provided with a simple undercut recess or edge. 
     A first embodiment or the invention provides for the deformable element to have an elastically deformable snap-in projecting part of the electronic module, which is preferably embodied as a snap-in or locking hook and can engage with an undercut recess or edge on the fan frame. The function of this snap-in projecting part is that, after engaging with the undercut recess or edge of the fan frame, it restricts the freedom of movement between these two components enough so that a stable fastening of the electronic module to the fan frame that is sufficient for vehicle operation is ensured. 
     A second alternative embodiment of the invention provides for the deformed element to be a partially elastic deformable cable of the electronic module, which is preferably permanently connected to the electronic module and is engaged for example by clipping or looping with deformation to a receptacle that is embodied expediently as a cable guide on the fan frame in order to fasten the electronic module to the fan frame. 
     In order to keep the number of deformable elements required for fastening the electronic module to a minimum, another preferred embodiment of the invention also provides for at least one rigid projecting retaining element attached to the electronic module at a distance from the deformable element, which retaining element can be inserted into a receptacle or an opening of the fan frame before the deformable element engages with said fan frame and, after engagement of the deformable element, together with said element provides for fixation of the electronic module with respect to the fan frame. The retaining element can also serve to equalize tolerances and/or to limit the movement possibilities of the electronic module and can be provided with suitable geometry for this purpose. 
     Another advantageous embodiment of the invention provides for the retaining element to also serve as an assembly aid, which after its insertion into the recess of the fan frame permits a single degree of freedom of movement of the electronic module with respect to the fan frame, whereby the snap-in projecting part on the electronic module can be brought into engagement with the undercut recess or edge without additional guidance just via such an assembly movement. The assembly can expediently be either a swiveling movement around an axis of rotation or a translation movement in one direction. 
     According to another advantageous embodiment of the invention, the deformable element and/or the retaining element engages with a clearance fit in the fan frame so that not only an equalization of tolerances of the electronic module and of the fan frame can be provided for, but also an equalization of tolerances of a cable leading to the electronic module. The electronic module is preferably fastened with play in two directions that are perpendicular to one another on the fan frame, whereby the play in one direction is supplied by a displaceability of the retaining elements and of the snap-in projecting parts and in the other direction by the elastic deformability of the snap-in projecting parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained in greater detail in the following in several exemplary embodiments based on the associated drawings. The drawings show: 
         FIG. 1  A perspective view of an electronic module for assembly on a fan frame; 
         FIG. 2  Another perspective view of the electronic module; 
         FIG. 3  A perspective view of the electronic module and the fan frame during assembly of the electronic module; 
         FIG. 4  A view from above of the electronic module and the fan frame after assembly of the electronic module; 
         FIG. 5  A perspective view of a modified electronic module; 
         FIG. 6  A perspective view of the electronic module from  FIG. 5  during assembly to the fan frame; 
         FIGS. 7 through 10  Partial sections of schematic side views of another modified electronic module and a modified fan frame in various assembly steps; 
         FIG. 11  A partial section of a schematic side view of the electronic module from  FIGS. 7 through 10  after assembly on another fan frame; 
         FIG. 12  A partial section of a schematic side view of another modified electronic modules and yet another fan frame. 
     
    
    
     DETAILED DESCRIPTION 
     The electronic modules  2  depicted in the drawings are used to electrically or electronically control the speed and power of an electric fan drive of a cooling blower or fan being used to cool an internal combustion engine in a motor vehicle. The fan includes a frame that is depicted partially in  FIGS. 3 and 4  (designated as a fan frame  4 ), which is used to fasten the fan in the motor vehicle and bears the fan drive and the fan wheel (not shown). 
     The electronic modules  2  are each comprised of a circuit board or printed circuit board or a punched grid with electronic or electrical or electromechanical components (not shown) accommodated in a housing  6 , a temperature sensor  8  projecting beyond the housing  6  on a longitudinal side of said housing and, for electrical connection to the on-board power supply of the motor vehicle, are provided either with a socket  10  ( FIGS. 1 through 6 ) for a plug cable or alternatively with a fixed plug cable  12  with a plug  14  ( FIG. 12 ). 
     As  FIG. 4  shows, the electronic modules  2  are mounted between two struts  16 ,  18  of the fan frame  4 , which connect an inner ring flange  20  that fastens the fan drive and an outer ring flange  22  of the fan frame  4  that surrounds the outer circumference of the fan frame so that electronic modules  2  are located in the intake air flow of the fan wheel. 
     For fastening to the fan frame  4 , the electronic module  2  depicted in  FIGS. 1 through 4  has, firstly, on its narrow side opposite from the plug socket  10 , two rigid projecting retaining tongues  24 , which can each be inserted into a tongue receptacle  26  that is formed on the fan frame  4  in the vicinity of the inner ring flange  20 . Secondly, the electronic module is provided, on each of its opposing longitudinal sides at a distance from the retaining tongues  24 , with a downwardly projecting (in relation to the horizontal alignment of the electronic module  2  in the figures) elastically deformable snap-in or locking hook  28 , which can lock into engagement with an undercut snap-in opening  30  in a hook receptacle  32  formed on the strut  16  or  18 . 
     As best depicted in  FIGS. 1 ,  3  and  12 , the retaining tongues  24  have a flat S-shaped cross section with a convex upwardly curved section  34  adjacent to the housing  6  of the electronic module  2  and a convex downwardly curved end section  36 , whose free end is aligned approx. parallel to the level upper and under side of the housing  6  and with horizontal alignment of the electronic module  2  lies somewhat beneath the convex upwardly curved section  34 . 
     As depicted best in  FIGS. 3 and 12 , the two tongue receptacles  26  each have a rectangular opening  38  in their upper side facing the electronic module  2 , through which the free end of the associated retaining tongue  24  can be inserted into the receptacle  26 . As  FIG. 12  shows best, the receptacle  26  is limited radially inwardly (in relation to the axis of rotation of the fan wheel) from the opening  38  upwardly by a molding  40 , which projects in the direction of the opening  38  over an adjacent inner limiting wall  42  of the receptacle  26  and with its underside serves as a limit stop for the free end of the concave end section  36  of the retaining tongue  24  when, in the assembly position of the electronic module  2  (see  FIG. 4 ), the convex section  34  rests on an outer limiting wall  44  of the receptacle  26  (see  FIG. 12 ) and the two snap-in hooks  28  are locked into place in the hook receptacles  32 . The width of the opening  38  and the distance between the two limiting walls  42  and  44  is selected so that, after insertion of the retaining tongues  24  into the tongue receptacles  26 , the electronic module  2  can swivel around an assembly axis of rotation running crosswise to the retaining tongues  24  through the tongue receptacles  26  in order to lock the snap-in hooks  28  into engagement with the hook receptacles  32 . 
     Instead of two retaining tongues  24  arranged next to one another at a distance, as depicted in  FIGS. 1 through 3 , a single retaining tongue (not shown) can also be provided, which can be inserted into a corresponding single tongue receptacle in the fan frame. 
     As  FIGS. 1 and 2  depict best, the two snap-in hooks  28  formed of an elastic plastic or bent from steel sheet each have an S-shaped cross section, which consists of a convex upwardly curved section  46  facing the housing  6  and a convex downwardly curved end section  48 . The section  46  is provided on its housing-side end with an anchoring part  50  projecting into the interior of the housing  6 , and, on the sides of the anchoring part  50 , has two extension projections  52  projecting downwardly, whose outer sides that face away from one another are formed as slanted insertion bevels  54 . The insertion bevels  54  make it easier to insert the snap-in hooks  28  into the hook receptacles  32  and serve as longitudinal limit stops in the hook receptacles  32 , which restrict movement parallel to the longitudinal sides of the electronic module  2  to a desired degree or play. The section  46  is widened somewhat above the two extension projections  52 , whereby the level under sides of two shoulders  56  formed on both sides of the extension projections  52  each form fixed limit stops to the left and right of the projections  52 , which limit stops serve to limit the path when inserting the respective snap-in hook  28  in the associated hook receptacle  32  and, to do so, hit against the upper side of adjacent lateral limiting edges of the snap-in opening  30 . 
     When the snap-in hooks  28  penetrate the rectangular snap-in opening  30  in the upper sides of the hook receptacles  32  from above when the electronic module  2  pivots around the assembly axis of rotation, the upwardly pointing legs  58  of their end sections  48  move along the limiting edges  60  of the snap-in openings  30  facing away from the housing  6  of the electronic module  2  into the hook receptacles  32 . In doing so, the snap-in hooks  28  are deformed elastically and compressed against the housing  6  until the free ends of the legs  58  reach under the undercut limiting edges  60  of the snap-in openings  30  and lock into place there. When locking into place, the free ends of the legs  58  grip under the adjacent outer limiting edge  60  of the snap-in openings  30 , whereby they abut the limiting walls of the hook receptacles  32  beneath the snap-in openings  30  with their outer sides with a certain residual stress and thereby hold the electronic module  2  in place with a clearance fit on the fan frame  4  in a direction transverse to its longitudinal sides. Because of the play between the insertion bevels and the adjacent lateral limiting edges of the hook receptacles  32  or snap-in openings  30  and because of an axial play of the retaining tongues  24  in the tongue receptacles  26 , the electronic module  2  can also shift in the direction of its longitudinal sides by a certain degree so that equalization of tolerances is possible in both directions. 
       FIGS. 5 and 6  show another electronic module  2 , in which the two retaining tongues  24  are attached on the longitudinal side of the electronic module  2  opposite from the temperature sensor  8 , while a single snap-in hook  28  is arranged next to the temperature sensor  8  and said snap-in hook can engage with a snap-in opening  30  of a hook receptacle  32  of the fan frame  4 . In this connection,  FIG. 6  shows the status after the retaining tongues  24  have been inserted into the adjacent tongue receptacles  26  of the fan frame  4 , when, as the arrow indicates, the electronic module  2  is swiveled around the assembly axis of rotation located in this area in order to insert the snap-in hook  28  into the snap-in opening  30  and engage with the hook receptacle  32 . 
     In order to facilitate detachment of the snap-in hook for possible disassembly of the electronic module  2 , the snap-in hook  28  of the electronic module from  FIGS. 5 and 6  has a narrow extension part  62  projecting over the free end of the end section  48  or of the leg  58 , and said extension part projects upwardly through the snap-in opening  30  and can be acted upon with force in order to compress the snap-in hook  28  manually. 
     Instead of the retaining tongues  24  and the snap-in hook  28 , the electronic module  2  depicted in  FIGS. 7 through 10  has two hook projections  66  on one side at a distance from one another that project beyond a fastening element  64  of the electronic module  2  and an elastically deformable snap-in tongue  68  arranged between the two hook projections  66 . 
     The fastening element  64  that is partially embedded in the housing  6  of the electronic module  2  has, for improved cooling, an edge part  70  that projects beyond a wide side of the housing  6  and has a level bearing surface  72 . Said bearing surface can be brought to bear with a neighboring level wide side surface  74  of the fan frame  4 , after the ends  76  of the two hook projections  66 , which ends are bent parallel to the bearing surface  72 , have been moved through complementary locking openings  78  having a slightly larger opening cross section in the fan frame  4 , as shown in  FIG. 8 . Then the electronic module  2  is shifted parallel to the wide side surface  74  of the fan frame  4  or rotated around an axis of rotation perpendicular to the wide side surface  74  of the fan frame  4 , as the arrow in  FIG. 9  indicates, in order to move the free ends  76  of the hook projections  66  (that project on one side) under the wide side surface  80  of the fan frame  4  that faces away from the electronic module  2 . In doing so, when elastically deformed, the snap-in tongue  68  moves over a projecting part  82  on the wide side surface  74  of the fan frame  4  and locks into place behind the projecting part  82 , when the parts  84  of the hook projections  66  perpendicular to the wide side surface  74  of the fan frame  4  that are above their bent free ends  76  hit against an adjacent limiting edge  86  of the locking openings  78 , as depicted in  FIG. 10 . 
     After it locks into place behind the projecting part  82 , the flexible elastic snap-in tongue  68  that is integrated into the fastening element  64  prevents undesired displacement or disassembly of the electronic module  2  due to vibrations caused by driving. 
       FIG. 11  shows a modification of the fan frame  4  depicted in  FIG. 10 , in which, instead of the projecting part  82  on the wide side surface  74  of the fan frame  4 , a snap-in opening  88  has been left free in the fan frame  4 , with which the snap-in tongue  68  can engage in the assembly position of the electronic module  2 . 
     The electronic module  2  depicted in  FIG. 12  is provided on one side with one or more retaining tongues  24 , whose embodiment corresponds to that of the retaining tongues  24  of the electronic module  2  in  FIGS. 1 through 6  and, just like the hook receptacles  26  in connection with these, have already been already described. However, in this case, instead of snap-in hooks  28  or snap-in tongues  68 , the cable  12  leading from the electronic module  2  to the on-board power supply of the motor vehicle and whose one end is permanently connected to the electronic module  2  is used to fasten the electronic module  2  on the fan frame  4 . To fasten the electronic module  2 , the cable  12  when partially elastically deformed is brought into engagement with a cable receptacle  90  formed on the fan frame  4 . 
     The cable receptacle  90  is comprised of two hook-like cable guide elements  94  formed on the fan frame  4  and projecting beyond a wide side surface  92  of the fan frame  4 , under which the cable  12  is fed, as well as a bar-shaped cable guide element  96  arranged between the elements  94 , over which the cable  12  is fed. Other embodiments are also conceivable, however.

Technology Classification (CPC): 5