Abstract:
A first retainer engages with an exterior side of an interior wall member to retain a lamp unit on an interior side of the interior wall member. A second retainer engages with an exterior side of a panel body to retain the interior wall member, on which the lamp unit is mounted, on an interior side of the panel body. The second retainer includes a flexible arm having a free end portion which is flexible in a first direction parallel with the panel body and a second direction perpendicular to the panel body. The free end portion is abutted against the exterior side of the panel body when the interior wall member is mounted on the panel body. A regulator prevents the free end portion of the flexible arm from being flexed more than a predetermined amount in the second direction when the flexible arm is not flexed in the first direction.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a lamp unit mounting structure in which a lamp unit is fitted to a lamp mounting window provided in an interior wall member and electric wires connected to the lamp unit are arranged on the interior wall member at a side of a vehicle body panel thereby to form a module, and the module is assembled to the vehicle body panel so as to cover the vehicle body panel, whereby the interior wall member and the lamp unit can be simultaneously assembled to the vehicle body panel.  
           [0002]    Heretofore, there have been proposed lamp unit mounting structures in which an interior wall member such as a roof trim or a door trim covering a vehicle body panel and a lamp unit such as a room lamp or a courtesy lamp are simultaneously fixed to a vehicle body panel in order to decrease number of steps of an assembling (fixing) work in an assembly line of vehicles.  
           [0003]    [0003]FIG. 7 is a longitudinal sectional view for explaining a related-art fixing structure of a room lamp which is disclosed in Japanese Patent Publication No. 2001-97112A.  
           [0004]    In the fixing structure, a room lamp  1  and a roof trim  2  are provisionally fixed to each other by a provisional retainer  4 , and at the same time, the room lamp  1  and a roof framework (reinforce)  3  of a vehicle body are plenarily fixed to each other by a plenary retainer  5 , thereby allowing the room lamp  1  and the roof trim  2  to be simultaneously fixed to the roof framework  3 .  
           [0005]    The provisional retainer  4  include an engaging hook  14  provided on a side of the room lamp  1 , and an engaging part  15  provided on a side of the roof trim  2 .  
           [0006]    The plenary retainer  5  provided on the room lamp  1  and the roof framework  3  include a spring  7  and a stopper  9  which are provided in the room lamp  1 , and a fixing part  10  which is provided at an edge of a cut-out  13  formed in the roof framework  3 .  
           [0007]    The spring  7  made of a metal plate includes, as also shown in FIG. 8, an embedded portion  7   a  horizontally embedded in a lamp housing  11  of the room lamp  1 , a first elastically deformable portion  7   b  folded diagonally upwardly from the embedded portion  7   a  in an L-shape, a second elastically deformable portion  7   c  folded diagonally downwardly from the first elastically deformable portion  7   b  in an inverted U-shape, a hook portion  7   d  folded substantially horizontally from the second elastically deformable portion  7   c , and an operating portion  7   e  folded downwardly from the hook portion  7   d  in an L-shape.  
           [0008]    When the room lamp provided with the fixing structure is intended to be fixed in a vehicle, as a first step, the engaging hook  14  at the side of the room lamp  1  is engaged with the engaging part  15  at the side of the roof trim  2  so as to provisionally fix the room lamp  1  and the roof trim  2  by the provisional retainer  4 , prior to bringing them to an assembly line of the vehicle.  
           [0009]    Then, a roof subassembly (a roof module) composed of the room lamp  1  and the roof trim  2  which have been provisionally fixed by the provisional retainer  4  is incorporated into the assembly line of the vehicle.  
           [0010]    In this assembly line of the vehicle, the spring  7  at the side of the room lamp  1  is brought into elastic contact with the fixing part  10  at the side of the roof framework  3  in order to plenarily fix the roof subassembly composed of the room lamp  1  and the roof trim  2  to the roof framework  3  by the plenary retainer  5 . On this occasion, the engaging hook  14  will not interfere with a horizontal part  18  of the roof framework  3 , owing to provision of the cut-out  13  in the roof framework  3 .  
           [0011]    In this manner, with the fixing structure of the room lamp, the room lamp  1  and the roof trim  2  can be simultaneously fixed to the roof framework  3  in the assembly line of the vehicle, and as the results, the number of steps of the assembly work in the assembly line of the vehicle can be decreased.  
           [0012]    However, there has been such an anxiety, in the related-art fixing structure of the room lamp as shown in FIGS. 7 and 8, that when the room lamp  1  and the roof trim  2  are plenarily fixed to the roof framework  3  by the plenary retainer  5 , the hook portion  7   d  of the spring  7  may escape downwardly (toward an interior of the car) before the hook portion  7   d  of the spring  7  is set on the fixing part  10 , as shown in FIG. 9A, and after an inner face (an upper face in the drawings) of the roof trim  2  has been abutted against a face of the roof framework  3  at the room side (a lower face in the drawings), the hook portion  7   d  may be unable to come into contact with the fixing part  10  of the roof framework  3 , thus bringing the spring  7  in a half-fixed state.  
           [0013]    Under the circumstances, in order to prevent the spring  7  from being brought into the half-fixed state as described above, it has been necessary to provide a clearance t, as shown in FIG. 9B, between the fixing part  10  and the hook portion  7   d , when the inner face of the roof trim  2  is in contact with the room side face of the roof framework  3 . However, in case where such a clearance t becomes too large, it is concerned that the subassembly may rattle due to vibration or so of the car while driving, and may generate strange noises.  
           [0014]    Moreover, as far as the spring  7  of the retainer  5  is concerned, when the roof subassembly composed of the room lamp  1  and the roof trim  2  receives a strong external force which is exerted on the roof framework  3  toward the room side (downward in the drawings), there is such an anxiety that the fixation may be disengaged as shown in FIG. 9C, because the hook portion  7   d  is likely to be directed upward so that the holding strength is reduced.  
         SUMMARY OF THE INVENTION  
         [0015]    It is therefore an object of the present invention to provide a favorable lamp unit mounting structure which is capable of assembling both a lamp unit and an interior wall member simultaneously to a vehicle body panel easily and reliably.  
           [0016]    In order to achieve the above object, according to the present invention, there is provided a lamp unit mounting structure, comprising:  
           [0017]    a panel body of a vehicle;  
           [0018]    an interior wall member, which covers an interior side of the panel body; and  
           [0019]    a lamp unit, including:  
           [0020]    a first retainer, which engages with an exterior side of the interior wall member to retain the lamp unit on an interior side of the interior wall member;  
           [0021]    a second retainer, which engages with an exterior side of the panel body to retain the interior wall member, on which the lamp unit is mounted, on the interior side of the panel body, the second retainer including a flexible arm having a free end portion which is flexible in a first direction parallel with the panel body and a second direction perpendicular to the panel body, the free end portion being abutted against the exterior side of the panel body when the interior wall member is mounted on the panel body; and  
           [0022]    a regulator, which prevents the free end portion of the flexible arm from being flexed more than a predetermined amount in the second direction when the flexible arm is not flexed in the first direction.  
           [0023]    According to the structure, when a module composed of the lamp unit mounted to the interior wall member is assembled to the vehicle body panel, the flexible arm is flexed into such a state as the free end portion can be engaged with or disengaged from the mounting part of the vehicle body panel.  
           [0024]    On this occasion, the regulators will restrict the free end portion from being displaced in the direction in which the lamp unit is mounted to or detached from the vehicle body.  
           [0025]    Therefore, when the lamp unit and the interior wall member are simultaneously assembled to the vehicle body panel as the module, the free end portion of the flexible arm will not escape to the interior of the vehicle in the direction in which the lamp unit is mounted to or detached from the vehicle body, before the free end portion is engaged with the mounting part of the vehicle body panel.  
           [0026]    Therefore, the second retainer will be prevented from being brought into a half-fixed state in which the free end portion of the flexible arm is unable to be engaged with the mounting part of the vehicle body panel, and can securely assemble the module to the vehicle body panel. Further, since the free end portion of the flexible arm will not escape to the interior of the vehicle in the direction in which the lamp unit is mounted to or detached from the vehicle body, there will be no need of providing an excessive clearance with respect to the mounting part of the vehicle body panel taking this escape into account.  
           [0027]    Furthermore, when the module which has been fixed receives a strong external force exerted on the vehicle body panel in a direction to the interior of the vehicle, the flexible arm whose free end portion is restricted from being displaced in the direction in which the lamp unit is mounted to or detached from the vehicle body will not be disengaged from the fixed state, because the distal end portion will be prevented from being directed upward.  
           [0028]    Preferably, the regulator includes a wall portion extending in the first direction, and the flexible arm includes a pair of projections arranged in the second direction such that the wall portion is fitted therebetween.  
           [0029]    Here, it is preferable that the regulator includes a guide slope on which the projections of the flexible arm are slidable so that the free end portion of the flexible arm is allowed to be flexed more than the predetermined amount in the second direction when the flexible arm is flexed in the first direction.  
           [0030]    In this case, when the module is assembled to the vehicle body panel, the free end portion will be flexed by the guide slope having the sliding guide face, into such a state as the free end portion can be engaged with or disengaged from the mounting part of the vehicle body panel, and at the same time displaced toward the vehicle body panel.  
           [0031]    As the results, the free end portion of the flexible arm can be securely engaged with the mounting part of the vehicle body panel, even though there is no clearance provided with respect to the mounting part of the vehicle body panel when the assembly to the vehicle body has been completed. Further, since an elastic repulsive force can be created in the flexible arm when the assembly to the vehicle body has been completed, the module will be prevented from rattling with respect to the vehicle body panel.  
           [0032]    Preferably, the lamp unit includes an elastic piece which is elastically abutted against the interior side of the panel body when the interior wall member is mounted on the panel body.  
           [0033]    In this case, the module will be prevented from rattling with respect to the vehicle body panel. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0034]    In the accompanying drawings:  
         [0035]    [0035]FIG. 1 is an exploded perspective view of a lamp unit mounting structure according to one embodiment of the present invention;  
         [0036]    [0036]FIG. 2 is an enlarged perspective view of an essential part of a retainer shown in FIG. 1;  
         [0037]    [0037]FIGS. 3 and 4 are longitudinal sectional views for explaining a process of mounting a lamp unit shown in FIG. 1 to a vehicle body panel;  
         [0038]    [0038]FIG. 5 is a cross sectional view for explaining the process of mounting the lamp unit shown in FIG. 1 to the vehicle body panel;  
         [0039]    [0039]FIGS. 6A to  6 C are enlarged sectional views of the essential part for explaining action of the retainer shown in FIG. 2;  
         [0040]    [0040]FIG. 7 is a longitudinal sectional view for explaining a related-art lamp unit mounting structure;  
         [0041]    [0041]FIG. 8 is an enlarged sectional view of an essential part of a retainer shown in FIG. 7; and  
         [0042]    [0042]FIGS. 9A to  9 C are enlarged sectional views of the essential part for explaining action of the retainer shown in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]    A lamp unit mounting structure according to one embodiment of the present invention will be described in detail referring to the accompanying drawings.  
         [0044]    As shown in FIG. 1, a room lamp  20  is a lamp unit adapted to be fitted to a lamp mounting window  31  which is formed in a roof trim  30  as an interior wall member covering a roof of a vehicle body panel.  
         [0045]    The room lamp  20  is composed of a mechanical section A including a bulb  24  mounted on a housing  21  and a switch part (not shown), and attached to the roof trim  30  at a roof body side (an upper side in the drawing), and an appearance section B including a cover lens  51  and a holder  41 , and attached to the roof trim  30  at a room side (a lower side in the drawing).  
         [0046]    To the bulb  24  provided in the housing  21  which constitutes the mechanical section A, is connected, via the switch part which is not shown, an FFC  22  which is a group of electric wires constituting a roof harness.  
         [0047]    Specifically, a connecting part of the FFC  22  which is the roof harness to be arranged in advance on the roof trim  30  is electrically connected to a wire connecting part of the mechanical section A. A worker can conduct this connecting work while visually observing and confirming a state of the connection with his face down.  
         [0048]    The cover lens  51  constituting the appearance section B is integrally mounted on the holder  41 , by engaging locking projections  51   a  with engaging parts which are not shown of the holder  41 .  
         [0049]    The holder  41  is provided with engaging hooks  42  which are adapted to be engaged in engaging holes  32  formed in the roof trim  30  so as to fix the room lamp  20  and the roof trim  30  to each other, a housing insertion hole  46  into which the housing  21  is inserted, a retainer  43  for fixing the room lamp  20  and a reinforce  60  of the roof body to each other, and rattle preventive pieces  48  which are adapted to be elastically contacted with the reinforce  60  after the holder  41  has been mounted on the vehicle body.  
         [0050]    The engaging hooks  42  and the retainer  43  are respectively provided in pairs on diagonal lines of the holder  41  which is in a rectangular shape as viewed from the above. The rattle preventive pieces  48  are integrally formed in pairs respectively along shorter edges of the holder  41  so as to extend diagonally upwardly.  
         [0051]    Each of the retainer  43  is provided in a hanging manner on the holder  41  of the room lamp  20  at a side opposed to the reinforce  60  (an upper face side in the drawings), as shown in FIG. 2, and includes a flexible arm  44  whose distal end portion  44   c  is adapted to be engaged with a mounting part  61  of the reinforce  60 , and a pair of regulators  47  which are provided on both sides of the flexible arm  44 . The mounting part  61  is composed of an edge of a cut-out  62  in the reinforce  60 .  
         [0052]    The flexible arm  44  includes a vertical portion  44   a  integrally formed on the holder  41 , a flexible portion  44   b  folded diagonally downwardly from the vertical portion  44   a  in an inverted U-shape, and a support piece  45  which is suspended from a lower face of the flexible portion  44   b . The distal end portion  44   c  of the flexible portion  44   b  is engaged with the mounting part  61  of the reinforce  60 . Pairs of engaging projections  45   a ,  45   b  are respectively provided on opposite side edges of the support piece  45 .  
         [0053]    Each of the regulators  47  which are integrally formed on the holder  41  has a horizontal wall  47   a  which is engaged between a pair of the engaging projections  45   a ,  45   b  so as to restrict the distal end portion  44   c  from being displaced in a direction in which the room lamp  20  is mounted to or detached from the vehicle body (a vertical direction in the drawings).  
         [0054]    The horizontal wall  47   a  includes a guide slope  47   b  adapted to be engaged with the engaging projection  45   a , thereby allowing the distal end portion  44   c  of the flexible arm  44  which is flexed when mounted to or detached from the vehicle body to be displaced toward the reinforce  60 .  
         [0055]    In an event that the room lamp  20  in the present embodiment is mounted to the roof trim  30 , the holder  41  is fitted to the lamp mounting window  31  formed in the roof trim  30  so as to cover the window, as a first step, and the engaging hooks  42  of the holder  41  are engaged in the engaging holes  32  in the roof trim  30 , thereby allowing the holder  41  and the roof trim  30  to be fixed to each other. On this occasion, the retainer  43  and the rattle preventive pieces  48  will not interfere with the roof trim  30 , owing to presence of the openings  33  formed in the roof trim  30  (See FIG. 3).  
         [0056]    By fitting the cover lens  51  to the holder  41  from the vehicle room side (a lower side in FIG. 1) of the roof trim  30 , the appearance section B is mounted to the roof trim  30  in advance.  
         [0057]    Then, the housing  21  constituting the mechanical section A of the room lamp  20  which has been connected to the connecting part of the FFC  22  is inserted into the housing insertion hole  46  in the holder  41  from the side of the reinforce  60  (an upper side in the drawings), and trim mounting parts  23  are engaged with an open edge of the lamp mounting window  31 , so that the mechanical section A can be directly mounted to the roof trim  30 , as shown in FIG. 3.  
         [0058]    On this occasion, the cover lens  51  may be mounted to the holder  41 , after the housing  21  has been inserted into the housing insertion hole  46  in the holder  41 .  
         [0059]    After that, by arranging the FFC  22  to the roof trim  30  at the side of the reinforce  60 , and at the same time, by mounting roof attachments such as a back mirror and sun visors which are not shown to the roof trim  30  beforehand, a roof module in which the room lamp  20  is integrated with the roof trim  30  together with these roof attachments is composed, as shown in FIG. 3.  
         [0060]    Then, as shown in FIGS. 4 and 5, the roof module in which the room lamp  20  and the roof trim  30  have been integrated is mounted to the roof body. On this occasion, the room lamp  20  and the roof trim  30  are fixed to the reinforce  60  by the retainer  43 , by engaging the distal end portions  44   c  of the flexible arms  44  provided on the room lamp  20  with the mounting parts  61  of the reinforce  60 .  
         [0061]    In this manner, according to the mounting structure of the lamp unit in the present embodiment, the assembly work will be simplified, because the assembly work will be completed by simply mounting the roof module in which the room lamp  20  and the roof trim  30  have been integrated to the reinforce  60  of the roof body, and the mounting work of the roof attachments can be omitted when the roof trim is mounted.  
         [0062]    Particularly, the retainer  43  in the present embodiment can easily and reliably assemble the room lamp  20  and the roof trim  30  at the same time to the reinforce  60  of the roof body owing to the flexible arm  44  and the regulators  47 .  
         [0063]    More specifically, in the retainer  43  in the present embodiment, an edge of the horizontal wall  47   a  of each of the regulators  47  which are integrally formed on the holder  41  is engaged between a pair of the engaging projections  45   a ,  45   b  which are provided on opposite side edges of the support piece  45  of the flexible arm  44 , as shown in FIG. 6A, thereby to restrict the distal end portion  44   c  from being displaced more than predetermined amount in the direction in which the room lamp  20  is mounted to or detached from the vehicle body (in a vertical direction in the drawings).  
         [0064]    On occasion of mounting the roof module to the reinforce  60 , when the flexible portion  44   b  of the flexible arm  44  has come into contact with the edge  61   a  of the mounting part  61 , the distal end portion  44   c  rides over the edge  61  a and the flexible portion  44   b  is flexed, until the flexible arm  44  can be engaged or disengaged with respect to the mounting part  61 .  
         [0065]    At this instance, because the engaging projection  45   a  provided on the support piece  45  of the flexible arm  44  comes into contact with an upper face of the horizontal wall  47   a  of the regulator  47 , the flexible portion  44   b  can be displaced only in a direction in which the distal end portion  44   c  is brought near the vertical portion  44   a , but can be hardly displaced downwardly in the direction in which the room lamp  20  is mounted to or detached from the vehicle body (in a vertical direction in the drawings).  
         [0066]    Accordingly, when the room lamp  20  and the roof trim  30  are simultaneously mounted to the reinforce  60  as the module, the distal end portion  44   c  will not escape toward the vehicle room side (downwardly) in the direction in which the room lamp  20  is mounted to or detached from the vehicle body, before the distal end portion  44   c  of the flexible arm  44  is engaged with the mounting part  61  of the reinforce  60 .  
         [0067]    As the results, the distal end portion  44   c  of the flexible arm  44  will be prevented from coming into a half-fixed state without being engaged with the mounting part  61  of the reinforce  60 , and the retainer  43  will be able to securely assemble the module to the reinforce  60 .  
         [0068]    Further, since the distal end portion  44   c  of the flexible arm  44  will not escape toward the vehicle room side in the direction in which the room lamp  20  is mounted to or detached from the vehicle body, when mounted to the vehicle body as described above, there is no need of providing an excessive clearance with respect to the mounting part  61  of the reinforce  60  taking this escape into account.  
         [0069]    Furthermore, the horizontal wall  47   a  of the regulator  47  in the present embodiment is provided with the guide slope  47   b  having the sliding guide face which is adapted to be engaged with the engaging projections  45   a  and  45   b , as shown in FIG. 6B, to displace the distal end portion  44   c  of the flexible arm  44  which is flexed while mounted to or detached from the vehicle body toward the reinforce  60 .  
         [0070]    When the module is assembled to the reinforce  60  of the roof body, the flexible portion  44   b  is flexed in such a direction that the distal end portion  44   c  may be brought near the vertical portion  44   a  and displaced into a detachable state with respect to the mounting part  61 . At the same time, the flexible portion  44   b  is displaced also toward the reinforce  60  (upwardly), so that the distal end portion  44   c  can be displaced upwardly more than in an ordinary state and can reliably ride over an edge  61  a of the mounting part  61 .  
         [0071]    Accordingly, the distal end portion  44   c  of the flexible arm  44  can be securely engaged with the mounting part  61 , even though such a clearance as the clearance t in the related-art fixing structure of the room lamp as shown in FIG. 9B is not provided with respect to the mounting part  61 , when the assembly to the vehicle body has been completed.  
         [0072]    Further, as shown in FIG. 6C, when the distal end portion  44   c  has ridden over the edge  61  a, an upward force of the guide slope  47   b  exerted on the flexible portion  44   b  is removed, and the distal end portion  44   c  will be restored to the ordinary state. Then, an elastic repulsive force can be created in the flexible arm  44  when the assembly to the vehicle body has been completed, and the flexible portion  44   b  is elastically abutted against the mounting part  61 , thus preventing the module from rattling with respect to the reinforce  60 .  
         [0073]    In addition, there are provided rattle preventive pieces  48  in the holder  41  of the room lamp  20  in the present embodiment. The rattle preventive pieces  48  are elastically abutted against the reinforce  60  after the room lamp has been assembled to the vehicle body, as shown in FIGS. 5 and 6C. As the results, in case where a gap has been created between the distal end portion  44   c  and the mounting part  61  due to molding errors or assembling tolerances for example, rattling of the module with respect to the reinforce  60  can be reliably prevented by the rattle preventive pieces  48 .  
         [0074]    Consequently, the module will not rattle due to vibration of the car while driving, and occurrence of strange noises will not be incurred.  
         [0075]    Moreover, as shown in FIGS. 4 and 6C, when the module fixed to the reinforce  60  of the roof body has received a strong external force exerted on the reinforce  60  toward the interior of the room (downwardly in the drawings), the engaging projection  45   b  projected from the support piece  45  of the flexible arm  44  is abutted against a lower face of the horizontal wall  47   a  of the regulator  47 , and the distal end portion  44   c  of the flexible portion  44   b  can hardly be displaced upwardly in the direction in which the room lamp  20  is mounted to or detached from the vehicle body (in a vertical direction in the drawings).  
         [0076]    In this manner, the distal end portion  44   c  of the flexible arm  44  will be prevented from being directed upward, the holding strength will be enhanced, and accordingly, the distal end portion  44   c  will not be disengaged from the fixed state.  
         [0077]    It is needless to say that the constitution of the vehicle body panel, the interior wall member, the lamp unit, the wire connecting part and the electric wires, etc. in the mounting structure of the lamp unit according to the present invention is not restricted to the above embodiment, but various modifications can be employed based on concept of the present invention.  
         [0078]    For example, although in the embodiment, the description has been made in case that the room lamp which is the room unit is mounted to the roof trim which is the interior wall member, the present invention can be applied to such cases as a map lamp to be mounted to the roof trim, a lamp unit such as a courtesy lamp to be mounted to a door trim as the interior wall member covering the vehicle body panel such as a door panel, etc.  
         [0079]    As the electric wires to be arranged in the interior wall member, not only the FFC in the embodiment, but also an FPC (a flexible printed wiring board) and a flat circuit such as ribbon type electric wires, a wire harness, and so on can be employed.