Abstract:
The vehicular seat support mechanism includes a vehicular seat having a seat cushion that forms a sitting portion, the seat cushion having a pivot axis, which is horizontal with respect to the width direction of a vehicle, provided toward the rear thereof, which enables the seat cushion to pivot in a fore-and-aft direction of a vehicle, and a link mechanism that moves the pivot axis of the seat cushion to rear and downward. This support mechanism reduces the height of the pivoting locus of the seat drawn when the seat is placed into storage, thus allowing the seat to be pivoted into storage without requiring a large space.

Description:
[0001]    The disclosure of Japanese Patent Application No. 2000-51602 filed on Feb. 28, 2000 including the specification, drawings and abstract is incorporated herein by reference in its entirety.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to a vehicular seat support structure for supporting a vehicular seat.  
           [0004]    2. Description of Related Art  
           [0005]    One type of existing vehicular seat support mechanism supports a rear end portion of a seat cushion of a vehicular seat at a forward side of a storage recess formed in a compartment floor in such a manner that the seat cushion is pivotal in fore-and-aft directions. This mechanism functions so that the vehicular seat can be placed into the storage recess by pivoting the seat rearwards, with the seatback placed down over the seat cushion.  
           [0006]    This support mechanism, as described in Japanese Utility Model Registration No. 2594404 (U.S. Pat. No. 5,269,581), includes a pair of right and left-side bars and a pair of right and left-side mounting brackets. The right and left-side bars are provided on right and left-side edge portions of a forward portion of the storage recess, which are protruded inwards in the storage recess. The right and left-side bars form a pivot of a seat cushion and a seatback. The right and left-side mounting brackets are provided at right and left-side sites in a rear end portion of the seat cushion. The mounting brackets are supported by the right and left-side bars so that the brackets are pivotal in the fore-and-aft directions. In this manner, the rear end portion of the seat cushion is supported pivotally in the fore-and-aft directions.  
         SUMMARY OF THE INVENTION  
         [0007]    Accordingly, it is an object of the invention to provide a support mechanism for a vehicular seat that has improved operability in placing the vehicular.  
           [0008]    The invention relates to a vehicular seat support mechanism. The vehicular seat support mechanism includes a vehicular seat having a seat cushion that forms a sitting portion, the seat cushion having a pivot axis, which is horizontal with respect to the width direction of a vehicle, provided toward the rear thereof, which enables the seat cushion to pivot in a fore-and-aft direction of a vehicle, and a link mechanism that moves the pivot axis of the seat cushion to rear and downward.  
           [0009]    The support mechanism may support a rear end portion of a seat cushion forming a vehicular seat at a site forward of a storage recess portion provided in the compartment floor, in such a manner that the seat cushion is pivotal in fore-and-aft directions. The support mechanism may further functions to allow the vehicular seat to be placed into the storage recess portion by pivoting the seat rearward. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The foregoing and further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:  
         [0011]    [0011]FIG. 1 is a schematic diagram of a vehicle equipped with a rear seat that is supported by adopting support mechanisms in accordance with an embodiment of the invention;  
         [0012]    [0012]FIG. 2 is a partially cut-away perspective view illustrating a state in which each seat cushion forming the rear seat is supported;  
         [0013]    [0013]FIG. 3 is a perspective view illustrating a seat frame structure of a left-side seat of the rear seat, and support mechanisms attached to the seat frame structure;  
         [0014]    [0014]FIG. 4 is a side view of the rear seat supported on a compartment floor;  
         [0015]    [0015]FIG. 5 is a side view in which the rear seat is being placed into storage; and  
         [0016]    [0016]FIG. 6 is a side view in which the rear seat has been placed into storage. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0017]    The invention will be described hereinafter with reference to the accompanying drawings. FIG. 1 schematically illustrates a vehicle equipped with a rear seat that is supported by adopting a support mechanism in accordance with a preferred embodiment of the invention. The vehicle has a three-row seat arrangement in which three rows of seats are displaced in the fore-and-aft directions. That is, the vehicle has a first-row seat (front seat  10   a ), a second-row seat  10   b , and a third-row seat (rear seat  10   c ). The rear seat  10   c  has three sitting portions that are arranged in the right-and-left direction. As illustrated in FIG. 2, the rear seat  10   c  is divided at a proportion of 6:4 in the right-and-left direction into a left-side seat  10   c   1  and a right-side seat  10   c   2 . The left-side seat  10   c   1  and the right-side seat  10   c   2 , forming the rear seat  10   c , are supported at their rear end portions to a floor F by support mechanisms in accordance with an embodiment of the invention.  
         [0018]    The left-side seat  10   c   1  has a seat cushion  11  and a seatback  12 . As shown in FIG. 3, a seatback frame  12   a  of the seatback  12  is connected at its lower end portion to a rear end portion of a cushion frame  11   a  of the seat cushion  11  via a reclining mechanism  13 . During a normal state, the seatback  12  is set in an upright position. At the time of storage, the locking of the seat cushion  11  and the seatback  12  established by the reclining mechanism  13  is removed (unlocked), and the seatback  12  is pivoted down until a front surface of the seatback  12  contacts an upper surface of the seat cushion  11 . Thus, the seatback  12  assumes a state where the seatback  12  is placed over the seat cushion  11 . The right-side seat  10   c   2  has a seat cushion  14  and a seatback (not shown), and is constructed similarly to the left-side seat  10   c   1 . Each of the seat cushion  11  forming the left-side seat  10   c   1  and the seat cushion  14  forming the right-side seat  10   c   2  is supported to the floor F by a forward lock mechanism  20   a , a side lock mechanism  20   b , and a pair of right and left-side rearward support mechanisms  20   c.    
         [0019]    The forward lock mechanisms  20   a  are attached to forward end portions of inner lower arms  11   b ,  14   b  of the seat cushions  11 ,  14  via connecting portions so that the forward lock mechanisms  20   a  are pivotal in the right-and-left directions. As shown in FIG. 3, the seatback  12  is held to the seat cushion  11  in an upright state by the reclining mechanism  13 . The forward lock mechanism  20   a  is able to establish the seat cushion  11  in a locked state on the floor F by engaging with a corresponding one of strikers  21  provided on the floor F. Furthermore, the forward lock mechanisms  20   a  are designed so that the forward lock mechanisms  20   a  can be folded toward a lower-surface side of the seat cushions  11 ,  14  when the locked state is removed. The side lock mechanisms  20   b  are attached to forward end portions of outer lower arms  11   c ,  14   c  of the seat cushions  11 ,  14 . Each side lock mechanism  20   b  is positioned on an outer side of a corresponding one of the outer lower arms  11   c ,  14   c  as shown in FIG. 2. Each side lock mechanism  20   b  is designed so as to establish a locked state or an unlocked state by detachably engaging or disengaging with a striker  22  provided on an inward side wall of an adjacent tire housing (not shown) of the vehicle body. Each rearward support mechanism  20   c  is made up of a mounting bracket  23 , a first link  24 , and a second link  25 .  
         [0020]    As shown in FIGS.  4  to  6 , the compartment floor F has a storage recess f 2  that is formed rearward of a main floor portion f 1  on which the rear seat  10   c  is disposed. Mounting recess portions f 3  that are lower than the main floor portion f 1  are formed at sites forward of the storage recess f 2  that correspond to right and left sites in rear end portions of the seat cushions  11 ,  14 . The rearward support mechanisms  20   c  are disposed on the mounting recess portions f 3 , respectively. The left-side seat  10   c   1  and the right-side seat  10   c   2  are disposed on the main floor portion f 1  forward of the storage recess f 2 . Each of the left-side seat  10   c   1  and the right-side seat  10   c   2  is supported by the forward lock mechanism  20   a , the side lock mechanism  20   b , and the right and left-side rearward support mechanisms  20   c . With regard to each rearward support mechanism  20   c , the mounting bracket  23  is attached onto the corresponding mounting recess portion f 3  of the compartment floor F. In addition, the first link  24  and the second link  25  are connected to the mounting bracket  23  and to the corresponding one of the lower arms  11   b ,  11   c ,  14   b ,  14   c  of the seat cushion  11 ,  14 . In this vehicle, a carpet C is laid substantially over the enter surface of the compartment floor F.  
         [0021]    With regard to the left-side seat  10   c   1 , the mounting bracket  23  of each rearward support mechanism  20   c  is positioned under a corresponding one of right and left-side sites in a rear end portion of the seat cushion  11 . The first link  24  is connected at its lower end portion to a forward portion of the mounting bracket  23  in such a manner that the first link  24  is pivotal in the fore-and-aft directions. The first link  24  extends rearwardly upwards in an inclined state. An upper end portion of the first link  24  is connected to the corresponding one of the lower arms  11   b ,  11   c  of the seat cushion  11  in such a manner that the first link  24  is pivotal in the fore-and-aft directions. The second link  25  is connected at its lower end portion to a site of the mounting bracket  23  that is rearward of the site of connection to the first link  24 , in such a manner that the second link  25  is pivotal in the fore-and-aft directions. The second link  25  extends forwardly upwards in an inclined state, crossing the first link  24 . An upper end portion of the second link  25  is connected to a site in the rear end portion of the corresponding one of the lower arms  11   b ,  11   c  of the seat cushion  11  that is forward of the site at which the first link  24  is connected to the rear end portion of the lower arm, in such a manner that the second link  25  is pivotal in the fore-and-aft directions. In the above-described state, the right and left-side rearward support mechanisms  20   c  support the rear end portions of the seat cushion  11  at the right and left-side sites.  
         [0022]    With regard to the right-side seat  10   c   2 , the mounting bracket  23  of each rearward support mechanism  20   c  is positioned under a corresponding one of right and left-side sites in a rear end portion of the seat cushion  14 . The first link  24  is connected at its lower end portion to a forward portion of the mounting bracket  23  in such a manner that the first link  24  is pivotal in the fore-and-aft directions. The first link  24  extends rearwardly upwards in an inclined state. An upper end portion of the first link  24  is connected to the corresponding one of the lower arms  14   b ,  14   c  of the seat cushion  14  in such a manner that the first link  24  is pivotal in the fore-and-aft directions. The second link  25  is connected at its lower end portion to a site in the mounting bracket  23  that is rearward of the site of connection to the first link  24 , in such a manner that the second link  25  is pivotal in the fore-and-aft directions. The second link  25  extends forwardly upwards in an inclined state, crossing the first link  24 . An upper end portion of the second link  25  is connected to a site in the rear end portion of the corresponding one of the lower arms  14   b ,  14   c  of the seat cushion  14  that is forward of the site at which the first link  24  is connected to the rear end portion of the lower arm, in such a manner that the second link  25  is pivotal in the fore-and-aft directions. In the above-described state, the right and left-side support mechanisms  20  support the rear end portions of the seat cushion  14  at the right and left-side sites.  
         [0023]    The left-side seat  10   c   1  and the right-side seat  10   c   2  supported to the compartment floor F as described above can be placed into the storage recess f 2  independently of each other when necessary. When placed into storage recess f 2 , a space is formed, which can be used as a luggage compartment, over the site on the main floor portion f 1  for disposing the left-side seat  10   c   1  and the right-side seat  10   c   2  and over the storage recess f 2 , thereby forming a large luggage compartment rearward of the second-row seat  10   b . It should be noted that the manner of placing the left-side seat  10   c   1  into the storage recess f 2  and the manner of placing the right-side seat  10   c   2  into the storage recess f 2  are substantially the same. Therefore, the following description of the manner of placing the seats into the storage recess f 2  will be made by referring to the left-side seat  10   c   1  and the right-side seat  10   c   2  collectively as the rear seat  10   c  for the sake of convenience in description.  
         [0024]    FIGS.  4  to  6  illustrate a process of placing the rear seat  10   c  (the left-side seat  10   c   1  and/or the right-side seat  10   c   2 ) into the storage recess f 2 . During a normal seat state of the rear seat  10   c  as shown in FIG. 4, each seat cushion  11 ,  14  is supported on the compartment floor F by the forward lock mechanism  20   a  and the right and left-side rearward support mechanisms  20   c , and the seat cushion is further supported on the inner side wall of the adjacent tire housing (not shown) by the side lock mechanism  20   b.    
         [0025]    To place the rear seat  10   c  from this state into the storage recess f 2 , the locked state of each seat cushion  11 ,  14  retained by the forward lock mechanism  20   a  and the side lock mechanism  20   b  with respect to the compartment floor F and the inner side wall of the tire housing, respectively, is removed. Furthermore, the locked state of the seatback  12  retained by the reclining mechanism  13  with respect to the seat cushion  11 ,  14  is removed (unlocked), and then the seatback  12  is placed down over the seat cushion  11 ,  14 . Thus, the rear seat  10   c  is set in a folded state.  
         [0026]    Then, the rear seat  10   c  is pivoted rearward as indicated in FIG. 5 by raising a forward end portion of the rear seat  10   c  while maintaining the folded state where the seatback  12  is placed on the seat cushion  11 ,  14 . The rear seat  10   c  is thus placed into the storage recess f 2  rearward of the site for disposing the rear seat  10   c . When the rear seat  10   c  has been placed into the storage recess f 2  while the folded state is maintained, the lower surface of the seat cushions  11 ,  14  is at an upper position and the forward lock mechanisms  20   a  are protruded upwards. Therefore, the forward lock mechanisms  20   a  are subsequently pivoted down onto the seat cushions  11 ,  14 . Thus, the rear seat  10   c  is stored as shown in FIG. 6, so that the site in the compartment floor F for disposing the rear seat  10   c  and the opening portion of the storage recess form an integral flat surface, thereby forming a large luggage compartment in the vehicle. The rear seat  10   c  can be returned from the storage recess f 2 -stored state to the normal seat state by reversing the above-described procedure.  
         [0027]    Thus, the rear seat  10   c , in which each seat cushion  11 ,  14  is supported at the right and left-side sites in the rear end portion thereof by the right and left-side rearward support mechanisms  20   c , is placed into the storage recess f 2  as described above, so that the rear seat disposing site in the main floor portion f 1  in the compartment floor F and the opening portion of the storage recess f 2  form an integral flat surface, thereby forming a large luggage compartment. During the process of placing the folded rear seat  10   c  into storage, each rearward support mechanism  20   c  turns along arc-shaped loci indicated by one-dot chain lines in FIG. 4 from the normal seat state shown in FIG. 4 to the stored state shown in FIG. 6.  
         [0028]    More specifically, the first link  24  of each rearward support mechanism  20   c  pivots rearwards and downwards about a lower end connecting portion a at which the first link  24  is connected to the mounting bracket  23 , so that an upper end connecting portion a 1  at which the first link  24  is connected to a corresponding one of the seat cushions  11 ,  14  is moved to a rearward and downward position a 2 . The second link  25  pivots rearwards and downwards about a lower end connecting portion b at which the second link  25  is connected to the mounting bracket  23 , so that an upper end connecting portion b 1  at which the second link  25  is connected to the corresponding one of the seat cushions  11 ,  14  is moved to a rearward and downward position b 2 .  
         [0029]    Therefore, during the operation of placing the rear seat  10   c  into storage, the folded rear seat  10   c  pivots rearward while a rear end portion of the rear seat  10   c  moves downward gradually, due to the pivoting motion of the first link  24  and the pivoting motion of the second link  25  that follows the pivoting motion of the first link  24 . Therefore, the pivoting locus of a distal end portion of the folded rear seat  10   c  forms an elliptic shape whose pivot center is lower than that of a circular locus of a pivoting motion (circular motion) about a single pivot, and whose height is less than that of the circular locus.  
         [0030]    The rear end portion of the rear seat  10   c  moves to the rear and downward gradually because the pivoting motion of the support mechanisms  20   c  is not the pivoting motion forming circular motion about a single pivot like the conventional support mechanism. Therefor, an area of the pivoting motion is small in comparison with the conventional support mechanism. Furthermore, the pivot axis of the rear seat  10   c  becomes lower so that the up-down movements of the center of gravity of the rear seat  10   c  becomes less. Therefore, the labor required for the storing operating is reduced. Furthermore, since each support mechanism  20   c  supports the rear end portion of a corresponding one of the seat cushions  11 ,  14  using the first link  24  and the second link  25  crossing each other, the supporting mechanism  20   c  has a sufficient effect of anchor when a seat belt is adopted to the rear seat. Furthermore, the support mechanisms  20   c  have sufficient support strength enough to absorb an impactive force in a fore-and-aft directions of the vehicle.  
         [0031]    Thus, the support mechanisms  20   c  are effective at supporting the rear seat  10   c  made up of a plurality of seats divided in the right-and-left directions (the left-side seat  10   c   1  and the right-side seat  10   c   2 ). The rearward support mechanisms  20   c  can be adopted not only as support mechanisms for supporting an elongated bench type seat having a plurality of sitting portions arranged in the right-and-left directions, but also as support mechanisms for supporting a seat having a single sitting portion.  
         [0032]    Although in the foregoing embodiment, the support mechanism of the invention is adopted for the rearmost seat (third-row seat) in a vehicle having a three-row seat arrangement, the support mechanism of the invention is not limited to that embodiment, but may also be adopted for the second-row seat in a vehicle having a two-row seat arrangement. In such a case, the support mechanism of the invention achieves substantially the same advantages as those achieved by the foregoing embodiment.  
         [0033]    Furthermore, the mounting bracket  23  of each rearward support mechanism  20   c  is disposed in the mounting recess portion f 3  that is lower than the main floor portion f 1  of the compartment floor F. Therefore, when the rear seat  10   c  is placed into storage, no component member of the rearward support mechanisms  20   c  protrudes above from the main floor portion f 1 , so that the site for disposing the rear seat  10   c  and the storage site altogether form a substantially flat surface, thereby providing a large luggage compartment.  
         [0034]    Although in the foregoing embodiment, the support mechanism including two links, for example the first link  24  and the second link  25 , is adopted as the vehicular seat support mechanism of the present invention, the vehicular seat support mechanism may be a mechanism such as that the pivot axis moves to either front or rear and downward. The support mechanism of the invention is not limited to that mechanism including two links. If a link mechanism including only the first link  24  is adopted to the support mechanism, the invention achieves substantially the same advantages as those achieved by the foregoing embodiment.  
         [0035]    Further, although in the foregoing embodiment, the storage recess f 2  is provided toward the rear of the rear seat  10   c , the storage recess f 2  may be provided toward the front of the rear seat  10   c.    
         [0036]    While the invention has been described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the preferred embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the preferred embodiments are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.