Abstract:
A front end module assembly structure for a vehicle, including: a first bracket plate provided on either a front end module or a side member, which is provided with a through hole and a slit extending upward therefrom; a second bracket plate provided on the other of the front end module and the side member to be mated to the first bracket plate, which has an insertion hole formed thereon at a position corresponding to the slit of the first bracket plate; and a locator piece attached to the second bracket plate. The locator piece has a portion configured to be inserted into the slit from a position inside the through hole and held in the slit, and a bottom face configured to be set on a periphery of the insertion hole when the locator piece is inserted into the insertion hole.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to an assembly structure of side members of a vehicle and a front end module thereof assembled to the front ends of the side members.  
         [0003]     2. Description of Related Art  
         [0004]     Formerly, headlamps and heat-exchanger equipment such as a radiator are attached to or installed on a pre-assembled vehicle body in a former assembly line, specifically to a radiator core support connected to body side members. Therefore, increase in the number of parts to be attached or installed complicates the work performed on the assembly line, lowering the work efficiency.  
         [0005]     Recently, in order to improve the work efficiency in the final assembly line, headlamps and heat-exchanger equipment such as a radiator and a capacitor are preliminarily attached to or installed on a radiator core support to form a front end module in a line other than the final assembly line, for example, a line of a parts manufacturing company, and the front end module is fed to the final assembly line, as disclosed in Japanese Patent publications Nos. 2848666, 2898339, and 2907502.  
         [0006]     As the number of equipment to be mounted onto the front end module increases, the weight thereof becomes substantially heavy, which makes it difficult for a worker to handle the front end module.  
         [0007]     A loading jig for assisting the worker to lift the front end module is therefore provided on the final assembly line. The worker fastens rear ends of both sides of the front end module to the front ends of the side members with bolts and nuts, while lifting the front end module with the loading jig.  
         [0008]     In this case, the rear ends of both sides of the front end module and the front ends of the side members have to be positioned accurately.  
         [0009]     FIGS.  9  to  12  show a comparative example of a front end module assembly structure. As shown in  FIG. 10 , a bracket plate  7  is fixed to each of the rear ends of both sides of the front end module  5 . As shown in  FIG. 11 , a C-shaped cut is made in the center of the bracket plate  7 , and the cut portion is folded rearward so as to form an insert piece  8  in substantially a right triangular shape.  
         [0010]     Meanwhile, an insertion hole  10  is formed in a bracket plate  9  on the front end of a side member  6  so as to allow the insert piece  8  to be inserted thereinto. When the front end module  5  is connected to the side member  6 , the insert piece  8  is inserted into the insertion hole  10 , and a vertical positioning of the front end module  5  relative to the side member  6  is performed. Then the bracket plate  7  of the front end module  5  and the bracket plate  9  of the side member  6  are fixed with bolts and nuts.  
         [0011]     After fastening of the bracket plates  7  and  9 , the front portion of the front end module  5  is fixed to the side member  6  with fourteen (14) bolts (seven (7) bolts for each side), and the upper rear end portions are fixed to the side member  6  with four (4) bolts (two (2) bolts for each side) as shown in  FIG. 12 .  
       SUMMARY OF THE INVENTION  
       [0012]     In the case where the aforementioned loading jig is used for fixing the front end module  5  to the side member  6 , the level of the front end module  5  lifted by the loading jig varies between, for example, −3 mm and +3 mm. This lowers the accuracy in positioning of the front end module  5 .  
         [0013]     In the structure of the comparative example as described above, the positioning of the front end module  5  relative to the side member  6  is performed by inserting the insert piece  8  into the insertion hole  10 . Since the insert piece  8  is formed to be slightly smaller than the insertion hole  10  so as to allow easy insertion of the insert piece  8 , the aforementioned structure thus cannot improve the accuracy in positioning.  
         [0014]     It is an object of the invention to provide a front end module assembly structure that improves the accuracy in positioning of the front end module.  
         [0015]     An aspect of the present invention is a front end module assembly structure for a vehicle, comprising: a first bracket plate provided on either a front end module or a side member to which the front end module is assembled, the first bracket plate having thereon a through hole and a slit extending upward from the through hole; a second bracket plate provided on the other of the front end module and the side member to be mated to the first bracket plate, the second bracket plate having an insertion hole formed thereon at a position corresponding to the slit of the first bracket plate; and a locator piece attached to the second bracket plate, the locator piece having a portion configured to be inserted into the slit from a position inside the through hole and held in the slit, and a bottom face configured to be set on a periphery of the insertion hole when the locator piece is inserted into the insertion hole. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The invention will now be described with reference to the accompanying drawings wherein:  
         [0017]      FIG. 1  is a perspective view of a bracket plate attached to a front end module according to a front end module assembly structure of the present invention.  
         [0018]      FIG. 2  is a perspective view of a bracket plate of the front end module, and a locator piece fixed thereto.  
         [0019]      FIG. 3  is a perspective view of a front end of a vehicle in which the front end module assembly structure of the present invention is employed, showing a front end module and a side member thereof.  
         [0020]      FIG. 4  is an enlarged perspective view showing a part IV in  FIG. 3 .  
         [0021]      FIG. 5  is a perspective view of an insertion hole formed in the bracket plate of the side member and the locator piece.  
         [0022]      FIG. 6  is a sectional view of the locator piece fixed to the bracket plate of the front end module, and the insertion hole formed in the bracket plate of the side member.  
         [0023]      FIG. 7  is a sectional view taken along line VII-VII in  FIG. 6 .  
         [0024]      FIG. 8  is a perspective view of the front end module fixed to the side member.  
         [0025]      FIG. 9  is a perspective view of a front end module and a side member as a comparative example.  
         [0026]      FIG. 10  is an enlarged perspective view showing a part X in  FIG. 9 .  
         [0027]      FIG. 11  is a perspective view of the bracket plate attached to the front end module of the comparative example.  
         [0028]      FIG. 12  is a perspective view of the front end module fixed to the side member of the comparative example. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     An embodiment of the present invention will be explained below with reference to the drawings, wherein like members are designated by like reference characters.  
         [0030]     In a front section of a vehicle where a front end module assembly structure of the present invention is employed, an engine compartment  11  is, as shown in  FIG. 3 , defined by a pair of side members  13  extending in the vehicle longitudinal direction at both ends of the vehicle in the vehicle transverse direction, a front end module  12  that connects front ends of the side members  13 , a dash panel (not shown) provided to the rear parts of the side members  13 , and the like.  
         [0031]     The front end module  12  includes a radiator core support  14  that extends in the vehicle transverse direction, a radiator  15  as one of heat-exchanger equipment provided on the rear side of the central portion of the radiator core support  14 , a capacitor  16  as another heat-exchanger equipment provided on the front side of the central portion, and a pair of headlamps  17  attached to both ends of the radiator core support  14  in the vehicle transverse direction. In addition to those radiator  15 , capacitor  16 , and headlamps  17 , a bumper may be fixed to the front end module  12 .  
         [0032]     Each front end of the side members  13  is provided with a bracket plate  18  to which the front end module  12  is fixed.  
         [0033]     Referring to  FIG. 4 , the front end of the side member  13  is provided with the flat and vertically extending bracket plate  18  with its face directed frontward. A rectangular insertion hole  19  is formed in the center of the bracket plate  18 . The insertion hole  19  serves as a drain hole through which a coating material that resides in the side member  13  is drained outside.  
         [0034]     Referring to  FIG. 5 , a tongue piece  20  as a flat plate is formed at the lower periphery of the insertion hole  19 , which extends in substantially a horizontal direction inward of the side member  13  (rearward) with its flat top face directed upward. The insertion hole  19  is formed in the bracket plate  18  by making a C-shaped cut with its opening directed downward. Then the inner portion of the cut is folded rearward so as to form the tongue piece  20  integrally with the bracket plate  18 .  
         [0035]     Each rear end of both end portions of the front end module  12  in the vehicle transverse direction is provided with a flat vertically extending bracket plate  21  having its face directed rearward and formed to conform to the bracket plate  18 . A rectangular through hole  22  and a slit  23  provided at a position corresponding to the insertion hole  19  of the bracket plate  18 , which continuously extends from the upper portion of the through hole  22 , are formed in the center of the bracket plate  21 . A rectangular small hole  24  is formed on the upper periphery of the slit  23  on its extended axis.  
         [0036]     A locator piece  25  formed of a resin material and deformable to a slight degree is fixed to the bracket plate  21  of the front end module. The locator piece  25  has a substantially pentagon-shaped side view as shown in  FIG. 6 , which includes a flat bottom face  25 A that is horizontally arranged upon fixation, a back face  25 B and a front face  25 C both perpendicular to the bottom face  25 A, an upper inclined face  25 D with its height at the side of the back face  25 B greater than that at the side of the front face  25 C, each end of which intersects with the back face  25 B and the front face  25 C, and a lower inclined face  25 E with its height at the front face  25 C greater than that at the side of the front face  25 C, each end of which intersects with the bottom face  25 A and the front face  25 C, respectively.  
         [0037]     The distance between right and left side faces of the locator piece  25 , that is,  25 F and  25 G is gradually decreased from the back face  25 B to the front face  25 C as shown in  FIG. 7  such that a wedge shape is defined in section by the side faces  25 F,  25 G, and the front face  25 C. Note that each description of the bottom face  25 A, back face  25 B, front face  25 C, and side faces  25 F,  25 G is determined irrespective of the longitudinal or the transverse direction of the vehicle.  
         [0038]     Referring to  FIGS. 5 and 7 , vertical grooves  25 H,  25 I are formed in the side faces  25 F,  25 G of the locator piece  25  around the back face  25 B in parallel therewith, which extend in the vertical direction. The portion around the back face  25 B of the locator piece  25  is formed as an attachment portion thereof having an H-like horizontal cross section. Each length L 1  of bottom portions  25 Ha,  25 Ia of the vertical grooves  25 H,  25 I is made slightly shorter than the length L 2  of the slit  23 . Each width W of the vertical grooves  25 H,  25 I is made slightly smaller than the thickness T 1  of the peripheral portion of the slit  23 . The thickness T 2  of the distance between the bottom portions  25 Ha and  25 Ia of the vertical grooves  25 H,  25 I of the attachment portion is made slightly greater than the width W 2  of the slit  23 .  
         [0039]     A protrusion  25 J is formed as an engaging portion on the top of the locator piece  25 . The protrusion  25 J has a substantially triangular vertical cross section with its top end directed outward (to the upper side of the front face  25 C). The lower portion of the protrusion  25 J is formed as a neck portion  25 K with its width reduced. The protrusion  25 J is elastically swingable around the neck portion  25 K in the direction B as shown in  FIG. 6 . The end portion of the back face  25 B behind the upper inclined face  25 D downward of the protrusion  25 J is provided with a lateral groove  25 L that horizontally extends (in the vertical direction of  FIG. 6 ). The width W 3  of the lateral groove  25 L is made slightly smaller than the thickness T 3  of the upper periphery of the slit  23 .  
         [0040]     Operations of the above-structured front end module assembly structure will be described.  
         [0041]     The locator piece  25  is inserted from its back face  25 B into the through hole  22  formed in the bracket plate  21  of the front end module as indicated by arrow A of  FIG. 1 , and the portion between the bottom portions  25 Ha and  25 Ia of the vertical grooves  25 H and  25 I (web portion of the H-shaped cross section) is aligned with the center axis of the slip  23  before fixation of the front end module  12  to the side member  13 . As the locator piece  25  is moved upward, both peripheral portions of the slit  23  are fit with the vertical grooves  25 H,  25 I of the locator piece  25 . Each of the vertical grooves  25 H,  25 I has a width W 1  slightly smaller than the thickness T 1  of the peripheral portion of the slit  23 . The locator piece  25  may be elastically deformed such that each width W 1  of the vertical grooves  25 H,  25 I can be easily widened. This may allow both peripheries of the slit  23  to be easily fit with the vertical grooves  25 H,  25 I, respectively.  
         [0042]     As the locator piece  25  is further moved upward, the protrusion  25 J formed at the upper portion of the locator piece  25  swings by the deformation of the neck portion  25 K so as to be positioned over the upper periphery of the slit  23 . When the tip of the neck portion  25 K is moved over the upper periphery of the slit  23 , it is elastically deformed such that the tip of the protrusion  25 J is fit with the small hole  24 . At this time, a lower face  23   a  of the upper periphery of the slit  23  is brought into abutment on a bottom portion  25 La of the lateral groove  25 L of the locator piece  25 . This may regulate the upward movement of the locator piece  25 , thus tightly fixing the locator piece  25  to the bracket plate  21  of the front end module.  
         [0043]     Upon fixation of the front end module  12  to the side member  13 , the front end module  12  is lifted by the loading jig (not shown) and the bracket plate  21  of the front end module  12  is aligned with the bracket plate  18  of the side member  13  such that the locator piece  25  is inserted into the insertion hole  19  as indicated by arrow C of  FIG. 6 . As the locator piece  25  and the insertion hole  19  are respectively formed in the center of the bracket plate  21  of the front end module and in the center of the bracket plate  18  of the side member, it is difficult for the operator to confirm locations of the locator piece  25  and the insertion hole  19  upon the alignment. However, the upper inclined face  25 D and the lower inclined face  25 E of the locator piece  25 , and the wedge-shaped horizontal cross section of the locator piece  25  allow the operator to insert the locator piece  25  into the insertion hole  19  easily.  
         [0044]     When the locator piece  25  is inserted into the insertion hole  19 , the force that supports the loading jig that has been lifting the front end module  12  is slightly decreased. The front end module  12  then moves downward by its own weight such that the bottom face  25 A of the locator piece  25  is brought into abutment on the top face of the tongue piece  20  of the insertion hole  19 . In this case, keeping the level of the upper face of the tongue piece  20  with respect to the side member  13 , the level of the bottom face  23   a  of the upper periphery of the slit  23  with respect to the front end module  12 , and the height of the lateral groove  25 L from the bottom portion  25 La to the bottom face  25 A in the accurate conditions makes it possible to maintain the assembly position of the front end module  12  to the side member  13  with great accuracy.  
         [0045]     When the locator piece  25  is completely inserted into the insertion hole  19 , the loading jig is removed from the front end module  12 .  
         [0046]     According to the embodiment of the invention, the locator piece  25  is inserted into the insertion hole  19  so as to temporarily hold the front end module  12  to be fixed to the side member  13 . If the front end module  12  is assembled with the side member  13  in the aforementioned temporarily fixed state, the positioning accuracy in fixation of the front end module  12  may be improved.  
         [0047]     According to the embodiment, the locator piece  25  inserted into the insertion hole  19  supports part of the weight of the front end module  12 . The upper portion of the rear end portion of the front end module  12  is fixed to the side member  13  with two bolts (one for left and right) such that the front end module  12  is temporarily fixed to the side member  13 . Accordingly the process for fastening the front portion of the front end module  12  with bolts (see  FIG. 12 ) may be performed subsequently. This makes it possible to reduce the operation time for the process of fixing the front end module  12  to the side member  13 .  
         [0048]     According to the embodiment, the locator piece  25  is fixed to the bracket plate  21  of the front end module. This may increase the area of the contact between the bracket plate  21  and the locator piece  25  (as indicated by the shaded area). In the case where the contact area is 225 mm 2 , for example, it is confirmed that the locator piece  25  is capable of bearing the load of 30 kgf. Meanwhile, in the comparative example, as shown in  FIG. 11 , the cross section area (corresponding to the contact area) of the folded portion of the insert piece  8  is 60 mm 2  at most, which cannot bear the load of 30 kgf.  
         [0049]     The preferred embodiment described herein is illustrative and not restrictive, and the invention may be practiced or embodied in other ways without departing from the spirit or essential character thereof.  
         [0050]     In the embodiment as aforementioned, the locator piece  25  is fixed to the bracket plate  21  of the front end module. However, it is possible to form the locator portion corresponding to the locator piece  25  on the bracket plate  18  of the side member, and a hole corresponding to the insertion hole  19  formed in the bracket plate  21  of the front end module. Then a portion corresponding to the tongue piece  20  may be formed on the upper periphery of the hole corresponding to the insertion hole  19  such that the top face of the locator portion that has been inserted into the hole may abut on the lower face of the portion corresponding to the tongue piece.  
         [0051]     The scope of the invention being indicated by the claims, and all variations which come within the meaning of claims are intended to be embraced herein.  
         [0052]     The present disclosure relates to subject matters contained in Japanese Patent Application No. 2004-082289, filed on Mar. 22, 2004, the disclosure of which is expressly incorporated herein by reference in its entirety.