Abstract:
A front-end module for supporting heat exchangers in a vehicle includes a U-shaped assembly support having a horizontally extending base and two downward extending sidepieces, and a connecting support having a horizontal web which supports the heat exchangers. The assembly support is fitted over the heat exchangers, and the horizontal web is attached to the ends of the sidepieces so that the heat exchangers are surrounded and held in place.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a U.S. national stage of International Application No. PCT/EP2006/07535, filed on 29 Jul. 2006. Priority is claimed on German Application No. 10 2005 039 090.0, filed on 6 Aug. 2005. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to an assembly support system, especially a front-end module, for cooling components, especially for at least one heat exchanger and at least one fan frame, the system comprising an assembly support. 
     2. Description of the Related Art 
     A front-end module which comprises a closed assembly frame, to which a fan frame can be attached, is known from U.S. Pat. No. 6,685,258 B2. The fan frame forms the rear wall of an installation space for cooling components. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to create an assembly support system, especially heat exchangers and a fan frame, to form a module which simplifies the preassembly of the cooling components. 
     In an assembly support system, especially in a front-end module, for cooling components, especially for at least one heat exchanger and at least one fan frame, the assembly support is designed essentially in the form of a “U” with a base, from which two sidepieces extend, the ends of which are connected by a separate connecting support. Before assembly, the assembly support is not connected at the ends by the connecting support and thus is open on one side. This greatly simplifies the installation of the cooling components. After assembly, the connecting support completes the assembly support to form a closed assembly support frame, in which the cooling components are installed. The inventive assembly support system makes it possible to preassemble the components outside a motor vehicle assembly line with only one primary assembly direction. The present invention is preferably aimed at the use of all-metal cooling components without any additional soldered-on fastening means within the assembly support system. 
     A preferred exemplary embodiment of the assembly support system is characterized in that, in the installed state of the assembly support system, the two sidepieces of the assembly support extend downward. This directional specification pertains to a motor vehicle, for example, in which the inventive assembly support system has been installed. In this context, therefore, “downward” means vertically toward the bottom of the vehicle. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that the connecting support has an essentially L-shaped cross section with a first arm, especially a short arm, which forms a connecting web between the ends of the two sidepieces, and with a second arm, especially a long arm. The long arm of the connecting support forms a closing wall or rear wall of an installation space for the cooling components. The assembly support closed by the L-shaped rear wall forms a stiff assembly, which, after installation on the vehicle, represents an additional thrust-absorbing assembly for the vehicle. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that the first arm of the connecting support has a support surface for at least one cooling component, especially for at least one heat exchanger. Preferably several heat exchangers are held or supported in the vertical direction by this support surface. 
     Another preferred exemplary embodiment of the invention assembly support system is characterized in that the first arm of the connecting support extends forward from the rear in the longitudinal direction of the vehicle. As a result, it is possible to remove the assembly support in the installed state of the assembly support system without having to remove the connecting support with the cooling components. This offers the advantage that the cooling circuits do not have to be opened when removing the assembly support. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that the support surface for the cooling component, especially for the heat exchanger, has at least one positive-locking area for the positive mounting of an area of complementary design of the cooling component. As a result, the cooling component is secured in position in the longitudinal direction of the vehicle. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that, on the side facing the cooling component, the base of the assembly support has retaining elements, which hold the cooling component in place in the longitudinal direction of the vehicle. The retaining elements are preferably formed by positioning ribs, which rest on the heat exchanger or are arranged between two heat exchangers. 
     Another preferred exemplary embodiment of the inventive assembly support system is characterized in that, on the side facing the cooling component, the base of the assembly support has spring elements, which are spring-loaded against the cooling component. As a result, it is guaranteed that the cooling component is supported without play. 
     Another preferred exemplary embodiment of the invention assembly support system is characterized in that the connecting support is attached to the ends of the sidepieces of the assembly support. The connecting support is fastened preferably in a detachable manner; that is, it can be disconnected from the ends of the sidepieces of the assembly support without being destroyed. Screws, clips, or rivets can be used as fastening elements. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that at least one elastic sealing element is provided along the sides and/or on top of each cooling component, between the cooling component and the assembly support. The sealing element also serves to compensate for manufacturing tolerances. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that the sealing element has an essentially U-shaped cross section, which extends around the cooling component. As a result, tolerances both in the lateral or vertical direction and also in the longitudinal direction of the vehicle can be compensated. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that several heat exchangers are arranged on the first arm of the connecting support, i.e., the arm with the support surface, in such a way that they are enclosed by the assembly support. The preassembly of the inventive assembly support system or of the front end is preferably carried out in sequence from back to front in the longitudinal direction of the vehicle. During preassembly, the connecting support is first laid in an assembly jig. The connecting support preferably has the capacity to accommodate one or more cooling fans and other devices, such as fan shutters which open at high backpressures. The support surface is designed to hold and to support the cooling components. According to one aspect of the invention, formations are provided in the support surface of the connecting support, these being formed during the production of the connecting support by injection-molding. Correspondingly designed complementary opposing pieces of geometrically similar form are provided on the cooling components. After the cooling components have been installed on the support surface of the connecting support, the cooling components are thus held in place by a positive connection both in the downward direction and also in the longitudinal direction of the vehicle. 
     Another preferred exemplary embodiment of the assembly support system is characterized in that the second arm of the connecting support forms a rear wall, which comprises a fan frame. Preferably the rear wall also comprises a fan motor and other devices such as fan shutters. 
     Another preferred exemplary embodiment of the inventive assembly support system is characterized in that the assembly support and the connecting support are produced by injection-molding. The assembly support is preferably produced by a hybrid form of the injection-molding process. The connecting support is also preferably produced by injection-molding. The assembly support and the connecting support are preferably made of plastic; and, if necessary, a metal reinforcing piece can be provided in the area of the first arm of the connecting support. 
     Additional advantages, features, and details of the invention can be derived from the following description, in which, with reference to the drawings, various exemplary embodiments are described in detail. The features mentioned in the claims and in the description can be essential to the invention either individually or in any desired combination: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exploded view, in perspective, of an inventive assembly support system; 
         FIG. 2  shows a longitudinal cross section through the assembly support system of  FIG. 1  before assembly; 
         FIG. 3  shows a longitudinal cross section, on an enlarged scale, through part of the assembly support system of  FIG. 1  in the assembled state; 
         FIG. 4   a  shows a longitudinal cross section through the assembly support system of  FIG. 1  in the assembled state; 
         FIG. 4   b  shows a cross section through a heat exchanger of the assembly support system of  FIG. 1 ; and 
         FIG. 5  shows a cross section through a heat exchanger different from that of  FIG. 4   b  of the assembly system according to  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows an exploded perspective view of the inventive assembly support system  1 . The assembly support system  1  comprises an assembly support  2 , which is designed essentially in the form of a “U”. The assembly support  2  comprises a base  5 , from which two sidepieces  6 ,  7  extend downward. The free ends  8 ,  9  of the sidepieces  6 ,  7  can be connected by a connecting support  10 . The connecting support  10  has an essentially L-shaped cross section with a first, short arm  11  and a second, long arm  12 . At each of the lateral ends of the first arm  11 , the connecting support  10  has a fastening element  13 ,  14 . The fastening elements  13 ,  14  are used to attach the connecting support  10  to the ends  8 ,  9  of the sidepieces  6 ,  7  of the assembly support  2 . In the assembled state, the first, short arm  11  of the connecting support  10  forms a connecting web  11  between the free ends  8 ,  9  of the sidepieces  6 ,  7  of the assembly support  2 . 
     The second, long arm  12  of the connecting support  10  forms a rear wall of a cooling component installation space, which is also bounded by the assembly support  2  extending between the sidepieces  6 ,  7 . The rear wall formed by the second, long arm  12  of the connecting support  10  comprises a fan frame  15  with a fan rotor  16  and an associated fan motor. The rear wall also comprises fan shutters  18 . 
     The first, short arm  11  of the connecting support  10  forming the connecting web has a support surface  20  for three heat exchangers  21 ,  22 , and  23 . Heat exchanger  21  is a water cooler. Heat exchanger  22  is a low-temperature cooler. Heat exchanger  23  is an air-conditioning condenser. Heat exchangers  21 - 23 , which are also called cooling components, are, according to an essential aspect of the present invention, premounted on the support surface  20  of the connecting support  10 . The preassembled system consisting of the connecting support  10  and the three heat exchangers  21 - 23  is closed by the attachment of the assembly support  2 . Attaching the assembly support  2  to the connecting support  10  has the effect of holding the cooling components  21 - 23  securely in place in the assembly system  1 . 
       FIG. 2  shows a longitudinal cross section through the assembly support system  1  of  FIG. 1 . In the longitudinal cross section, we can see that, at the front end of the assembly support  2 , there is a stop strip  25  for the top edge of the heat exchanger  23 . In addition, there is an upward-curving retaining finger  26  at the top edge of the second, long arm  12  of the connecting support  10 . In the assembled state of the assembly support  2  and the connecting support  10 , this retaining finger grips a projection  27  on the assembly support  2 . 
       FIG. 3  shows an enlarged longitudinal cross section of part of the assembly support system of  FIG. 1 . We see in  FIG. 3  that there are downward-pointing positioning ribs  31 ,  32  on the base  5  of the assembly support  2 . The positioning rib  31  is located between the heat exchangers  23  and  22  and serves to hold the two heat exchangers  23 ,  22  in place in the longitudinal direction of the vehicle. 
       FIGS. 4   a  and  4   b  show various cross-sectional views of the inventive assembly support system in the assembled state. The heat exchangers  21 - 23  are enclosed by the assembly support  2  and the connecting support  10 , which form a closed frame around the periphery. Spring elements  41 ,  42 , which hold the heat exchanger  23  in place in the vertical direction, are provided on the base  5  of the assembly support  2 . 
       FIG. 5  shows a cross section similar to that of  FIG. 4   b  but through a different point. In  FIG. 5  we see that spring elements  51 ,  52 , which proceed from the base  5  of the assembly support  2 , are also resting on the top edge of the heat exchanger  22 . In addition, the heat exchanger  22  is held in position laterally by the ribs  55 ,  56  formed on the sidepiece  6  and by the ribs  57 ,  58  formed on the sidepiece  7  of the assembly support  2 . The ribs  55 ,  58  are preferably oriented in the main mold-removal direction of the injection mold used to produce the assembly support  2 . Depending on the shape and arrangement of the ribs or spring elements, extractor can be used to ensure that the part can be removed from the mold. 
     The inventive assembly support system  1  is assembled in sequence from back to front, looking in the direction of vehicle travel. First, the L-shaped rear wall with the mounting openings for one or more cooling fans and for other devices such as fan shutters which open at high backpressure is placed in an assembly jig. The first, short arm  11  of the connecting support  10  forms the support surface  20  for the cooling components  21 - 23 . According to one aspect of the present invention, positive-locking areas for the positive attachment of areas of the cooling components of complementary design are provided in the support surface  20 . 
     To increase the thermal efficiency of the mounted cooling components  21 - 23 , a sealing profile can be used around the sides and/or on the top. This profile is preferably U-shaped, so that it can extend around the sides in one piece and thus enclose the individual cooling components. Such a profile also makes it possible to compensate for manufacturing tolerances. 
     After all the cooling components  21 - 23  have been mounted on the support surface  20 , proceeding from back to front, the assembly support  2  can then be placed on the connecting support  10  with the cooling components  21 - 23  and thus complete the enclosure. Similar to the way in which the cooling components  21 - 23  are supported from underneath in the support surface  20  of the connecting support  10 , comparable retaining elements of the cooling components also engage in the assembly support  2 , which has been placed on top from the front. The U-shaped assembly support  2 , which is open toward the bottom, is designed to fit the cooling components on which it rests in such a way that a play-free connection is guaranteed between the cooling components and the connecting support. 
     For the play-free support of the cooling components in the vertical direction, the bottom side of the base  5  of the assembly support  2  is equipped with molded-on spring elements  41 ,  42 ,  51 ,  52 . The lower area of the assembly support  2  is connected by screws, clips, rivets, etc., to the connecting support  10 ; this can be done from the front, which facilitates the assembly process. Connecting the assembly support  2  positively or nonpositively to the connecting support  10  completes the closure and forms a sealed box around the cooling components  21 - 13 , at the same time providing the desired flow-exposed surface at the front and the intended venting surfaces at the rear. The assembly support  2 , which has been closed off by the connecting support, forms a stiff assembly, which, after installation in the vehicle, represents and additional thrust-absorbing assembly for the vehicle. 
     The inventive assembly support system can be easily adapted to the number and capacity of the various cooling components used within a design series comprising motors of different ratings or different sets of vehicle equipment without the need to invest heavily in molds. 
     The assembly support  2  and the connecting support  10  are preferably produced out of plastic by a hybrid method with inlaid metal parts by the injection-molding process. As a result of the inventive assembly support system, a uniform assembly direction, beginning from the back and proceeding to the front or top, is made possible. There is no need for any assembly jigs for attaching the cooling components. The cooling components  21 ,  22 ,  23  are held in place by ribs on the assembly support and by the recesses in the support surface for the cooling components in the assembly support system. The L-shaped rear wall  12  with the fan frame cooperates with the assembly support  2  to form a closed installation space for the cooling components with predetermined guidance of the air flow.