Abstract:
A vehicle seat cushion structure whereby even when a steering wheel or other object is pushed closer toward a vehicle occupant after a vehicle is involved in a head-on collision and little space is left in front of the vehicle occupant, the space can be readily enlarged. The cushion structure comprises a supporting member provided on a seat frame and a cushion member disposed in a folded state on the supporting member. The folded cushion member is capable of being withdrawn from a cushion removal opening formed on a side of a seat. Space is provided between the vehicle occupant and the steering wheel or the like when the cushion member is removed via the cushion removal opening.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a seat cushion structure for a vehicle, which is designed to provide a space needed to rescue an occupant of a vehicle or to allow him/her to escape when the vehicle is involved in a collision. 
       BACKGROUND OF THE INVENTION 
       [0002]    A seat apparatus is known from, e.g., JP 09-175243 A wherein a cushion is formed using an airspring, a seat is manually or automatically deflated, and a space needed to facilitate escape is formed. 
         [0003]    Further, a vehicle seat arranged to retract when a vehicle is involved in a head-on collision is disclosed in JP 2007-168703 A. 
         [0004]      FIG. 10  hereof illustrates the seat apparatus of JP 09-175243 A. As shown in  FIG. 10 , the vehicle seat apparatus  201  comprises a cushion  202  formed of an airspring  203 ; and a wire cable  204  that opens a stopcock  205  when a vehicle is involved in a collision and a vehicle body panel collapses, so that the weight of a vehicle occupant or another force causes air to be removed from a discharge opening  206  to cause the airspring  203  to deflate, thereby providing a space needed to rescue the vehicle occupant 
         [0005]    However, the air pressure of the airspring  203  changes in the seat apparatus  201  due to atmospheric pressure or other environmental conditions; therefore, the seat can become less comfortable, and the air pressure can be difficult to control. A control component for opening the stopcock  205  must also be added, making the structure more complex. 
         [0006]      FIG. 11  illustrates the vehicle seat of JP 2007-168703 A. As shown in  FIG. 11 , the vehicle seat apparatus  220  includes a controller  222  that, when a vehicle is involved in a head-on collision, causes, on the basis of information from an acceleration sensor  221 , drive means  223  to retract a sliding piece  224  to the state shown in the Figure, with the result that a locking part  225  is released from the seat. When a load is applied to the seat in a rearward direction, as shown by arrow a 1 , the vehicle seat  220  automatically retracts to allow the vehicle occupant to easily escape. 
         [0007]    However, since the seat is caused to retract automatically when a load is applied to the vehicle seat  221  in a rearward direction (in the direction shown by arrow a 1 ), a problem is presented in vehicles having a rear seat behind the seat  221 , because a passenger occupying the rear seat will serve as a source of interference. Furthermore, a rail that guides the retraction of the seat may deform in the event of a head-on collision. 
       SUMMARY OF THE INVENTION 
       [0008]    An object of the present invention is to provide a structure of a cushion for a vehicle seat that does not require compressed air or rails on which the seat slides longitudinally, and that facilitates the removal of a vehicle occupant from a space that has been reduced immediately after a vehicle is involved in a head-on collision. 
         [0009]    According to a first aspect of the present invention, there is provided a cushion structure for a vehicle seat covered by an outer member and disposed on a seat frame which is attached to a vehicle body, which cushion structure comprises: a supporting member provided on the seat frame; a cushion member in the form of an elongate thick plate disposed on the supporting member in a folded state; and a cushion removal opening formed on one of left and right side portions of the seat and sized to allow the folded cushion member to pass therethrough when the folded cushion member, while being unfolded, is withdrawn from on the supporting member. 
         [0010]    If an arrangement is provided whereby the cushion member is pulled from the cushion-removal opening when the instrument panel or steering wheel press inward in the direction of the vehicle occupant as a result of a head-on collision involving the vehicle, interfering with the vehicle occupant, and making it impossible to carry the vehicle occupant out of the vehicle, then the cushion member will be withdrawn from the space between the supporting member disposed on the seat frame and a pad member covering the cushion member. Therefore, the pad member will be crushed by the weight of the vehicle occupant or other force applied to the seat cushion. As a result, the vehicle occupant will be separated further from the compressed instrument panel and the steering wheel, and a space will be formed. Accordingly, an advantage is presented in that it becomes easier to remove the vehicle occupant from a space that has become cramped after a head-on collision. 
         [0011]    Preferably, the cushion member has a handle at an end positioned proximately to the cushion-removal opening. Accordingly, the end of the cushion member is readily pulled from the cushion-removal opening, the cushion member is readily removed from the space between the supporting member and pad member that covers the cushion member, and the vehicle occupant becomes easier to remove from a space that has become cramped after the vehicle has been involved in a head-on collision. 
         [0012]    Desirably, the cushion member has a low-friction member on a surface opposite a surface that contacts the supporting member. When the cushion material is folded, the friction coefficient when the two surfaces on the opposite side come into contact and rub against each other thus decreases. Accordingly, the cushion member becomes easier to withdraw, and the operation of removing the cushion member becomes easier. Therefore, it becomes easier to remove the vehicle occupant from a space that has become reduced when a vehicle is involved in a head-on collision. 
         [0013]    In a preferred form, the supporting member has a low-friction member on a surface thereof that contacts the cushion member. The friction coefficient associated with the sliding between the supporting member and cushion member slide decreases, the cushion member can be more readily removed, and the operation of removing the cushion member becomes easier. Therefore, it becomes easier to remove the vehicle occupant from a space that has become reduced when a vehicle is involved in a head-on collision. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Certain preferred embodiments of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which: 
           [0015]      FIG. 1  is a perspective view showing a cushion structure according to a first embodiment of the present invention as applied to a vehicle driver seat; 
           [0016]      FIG. 2  is a perspective view illustrating the cushion structure of  FIG. 1  with a part cut away; 
           [0017]      FIGS. 3A and 3B  are perspective views showing the cushion member of  FIG. 2  in a folded state and an unfolded state; 
           [0018]      FIG. 4  is a schematic view showing a steering wheel and the like moved closer to a vehicle occupant from the position of  FIG. 1  as a result of a head-on collision of the vehicle; 
           [0019]      FIG. 5  is a schematic view illustrating the cushion member withdrawn to provide a space between the vehicle occupant and the steering wheel; 
           [0020]      FIGS. 6A and 6B  are cross-sectional views illustrating the cushion member in a folded state and a withdrawn state; 
           [0021]      FIGS. 7A and 7B  are schematic views showing a cushion structure according to a second embodiment of the present invention; 
           [0022]      FIGS. 8A and 8B  are schematic views showing a cushion structure according to a third embodiment of the present invention; 
           [0023]      FIGS. 9A and 9B  are perspective views showing a cushion structure according to a fourth embodiment of the present invention; 
           [0024]      FIG. 10  is a schematic view showing, partly in cross section, a conventional cushion structure formed using an airspring; and 
           [0025]      FIG. 11  is schematic view showing a separate conventional vehicle seat employing a mechanism for automatically retracting the seat rearward. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Reference is now made to  FIGS. 1 to 6  showing a cushion structure according to a first embodiment of the present invention. 
         [0027]    As shown in  FIG. 1 , a vehicle seat comprises a driver seat  12  of a vehicle  11 . A cushion structure  16  of the driver seat  12  includes a first cushion structure  17  and a second cushion structure  18 . The cushion structure  16  is also applied to a front passenger seat not shown. Since the front passenger seat is substantially identical in construction to the driver seat, its discussion will be omitted. 
         [0028]    The vehicle  11  has a passenger compartment  21  and a vehicle body  22 . The vehicle body  22  comprises an underbody  23  forming a floor, a front body  24 , and a front right door  25 . An instrument panel  28 , a steering column  31 , and a steering wheel  32  are disposed in the front body  24 . 
         [0029]    As can be appreciated from  FIGS. 1 and 2 , the driver seat  12  comprises a seat cushion  34  and a seat back  36  connected to the seat cushion  34  via a reclining device  35 . 
         [0030]    The seat cushion  34  comprises a seat frame or a seat cushion frame  37  secured to the underbody  23 ; the first cushion structure  17  disposed on the seat cushion frame  37 ; a first pad member  41  covering the first cushion structure  17 ; and a first outer member  42  covering the first pad member  41 . 
         [0031]    The seat cushion frame  37  comprises a slide mechanism  43  secured to the underbody  23 ; and a first frame  44  attached to the slide mechanism  43 . The first cushion structure  17  is provided on a first supporting member  45 , which is attached to the first frame  44 . 
         [0032]    The first pad member  41  has a first cushion-accommodating recess  51  formed to accommodate a first cushion member  47 . The material used for the first pad member  41  is identical to existing materials composed of, e.g., urethane or the like. 
         [0033]    The supporting member  45  has a flat surface, and a layer composed of a fluororesin or other resin with a low friction coefficient is provided on the flat surface as a low-friction layer  52  (see  FIG. 6 ). 
         [0034]    The first cushion structure  17  contains the first supporting member  45 , which is provided to the seat cushion frame  37 ; the first cushion member  47 , which is foldedly disposed on the first supporting member  45 ; a first removal opening  53 , which is formed on the first frame  44  for removing the first cushion member  47 ; a first cushion removal opening  55  (see  FIG. 1 ) formed on a right-side part  54  (see FIG.  1 ) of the seat cushion  34  in substantial alignment with the first removal opening  53 ; and a first handle  56 , which is exposed to the passenger compartment  21  from the first cushion removal opening  55  and is attached to the first cushion member  47 . 
         [0035]    The first cushion removal opening  55  ( FIG. 1 ) is formed on a frame cover  57  of the first frame  44 , which is provided to the right outer part  54 . However, the first cushion removal opening  55  may be formed on the first outer member  42  positioned on the right outer part  54 . 
         [0036]    A seat back  36  comprises a seat back frame  61 , which is a seat frame connected via the reclining device  35  to the seat cushion frame  37 ; a second cushion structure  18 , which is disposed on the seat back frame  61 ; a second pad member  62 , which covers the second cushion structure  18 ; and a second outer member  63 , which covers the second pad member  62 . 
         [0037]    The seat back frame  61  has a second frame  64  that is secured to the reclining device  35 , and the second cushion structure  18  is provided to a second supporting member  65 , which is attached to the second seat frame  64 . 
         [0038]    The second pad member  62  has a second cushion-accommodating recess  67 , which is formed to accommodate a second cushion member  66 . The material used for the second pad member  62  is identical to existing materials composed of, e.g., urethane or the like. 
         [0039]    The second supporting member  65  has a low-friction member  52  processed in a manner identical to that of the first supporting member  45 , and is included in the second cushion structure  18 . 
         [0040]    The second cushion structure  18  comprises the second supporting member  65 , which is provided to the seat back frame  61 ; the second cushion member  66 , which is foldedly disposed on the second supporting member  65 ; a second removal opening  71 , which is formed on the second frame  64  allowing removal of the second cushion member  66 ; a second cushion removal opening  73  (see  FIG. 1 ), which is formed on a back right side part  72  ( FIG. 1 ) of the second outer member  63  to substantially the same size as the second removal opening  71 ; and a second handle  74 , which is exposed to the passenger compartment  21  via the second cushion removal opening  73  and is attached to the second cushion member  66 . 
         [0041]      FIGS. 3A and 3B  show the first cushion member  47  used in the cushion structure of the first embodiment in folded and unfolded states. 
         [0042]    The first cushion member  47  has a first surface  76 , which is formed in the shape of a long and thick plate, and comes into contact with the first supporting member  45 ; a second surface  77 , which is on the side opposite the first surface  76 ; and an end  78 , which communicates with the first surface  76  and the second surface  77 , and is disposed in the first cushion removal opening  55 . 
         [0043]    The first cushion member  47  has a pulling belt  81  comprising a low-friction member joined to the second surface  77 . The first handle  56  is linked to the pulling belt  81 . The symbol t indicates a thickness, W indicates a width, and a total length L is divided in two. In other words, the first cushion member  47  is not only divided into two parts, but is folded five times, as shown by the arrow b 1 , to a length that is one-tenth of the length L, in approximately 5 equal parts. The first cushion member  47  is disposed so as to lie in the longitudinal direction of the vehicle, and the front and rear of the first cushion member  47  are linked by the pulling belt  81 . 
         [0044]    The phrase “in the form of a thick plate” refers to a thickness of such a degree that the first cushion member  47  can exhibit a cushioning function. The thickness is not defined in terms of being equal to or greater than several millimeters or being in a range within two values of a certain number of millimeters. Accordingly, other terms that can be used are a “thickness at which a cushioning function is present” or “thickness at which a cushioning function is able to be exhibited.” 
         [0045]    The pulling belt  81  is made from, e.g., a polyamide resin (product name: Nylon). An adhesive or stitches are used to join the pulling belt  81  to the first cushion member  47 . 
         [0046]    A width Wb of the pulling belt  81  is of an arbitrary value, and one belt will be sufficient if the width Wb is large. 
         [0047]    The second cushion member  66  is identical to the first cushion member  47 , for which reason a description thereof has been omitted. 
         [0048]    The cushion member  47  is folded five times, but parts of adjoining folded-over surfaces can be joined using an adhesive with a low adhesive strength or a thread having a low tensile strength. As a result, it is possible to prevent the folded state from collapsing under the weight of the vehicle occupant. 
         [0049]    The thickness t, width W, and total length of the first cushion member  47  may be set as desired. The first cushion member  47  is folded five times in the present embodiment, but the number of folds and the form in which the first cushion member  47  is folded are not defined. 
         [0050]    The low-friction pulling belt  81  is joined to the second surface  77  of the first cushion member  47 ; however, the low-friction pulling belt  81  may be joined to the first surface  76  so that the belt  81  will be joined to both surfaces. 
         [0051]    The low friction pulling belt  81  may also be joined only to the first surface  76 . 
         [0052]    The pulling belt  81  also functions as a low-friction member, but another example that can be cited as a low-friction member is a resin layer that is applied or otherwise joined to the entirety of the first surface  76  and second surface  77 , holding the pulling belt  81  thereunder. 
         [0053]    The action of the cushion structure of the first embodiment will now be described. 
         [0054]    As shown in  FIG. 4 , when a vehicle  11  is involved in a head-on collision, the front body  24  suffers damage, in conjunction with which the instrument panel  28  (shown by the chain double-dashed line), the steering column  31 , and the steering wheel  32  are pushed inwardly within the passenger compartment  21  as shown by arrow b 2 , where they may reach as far as a vehicle occupant M sitting in the driver seat  12 . If conditions are such that the instrument panel  28  (indicated by the solid line), the steering column  31 , and the steering wheel  32  that have been pushed toward the vehicle occupant M prevent the occupant from being carried out of the vehicle, then a rescuer or another person pulls the first handle  56  and the second handle  74  provided to the driver seat  12  toward the front right door  25  (in the direction of arrow b 3 ). 
         [0055]    When the above action is performed, as shown in  FIG. 5 , the first cushion member  47  is withdrawn from the first removal opening  53  and the first cushion removal opening  55  in the direction of arrow b 4 ; and the first cushion material  47  is removed from the space between the first pad member  41  and the first supporting member  45  provided to the seat cushion frame  37  (see  FIG. 2 ). The first pad member  41  will collapse under the weight of the vehicle occupant M or another force applied to the seat cushion  34 . 
         [0056]    When the second handle  74  is pulled toward the front right door  25  (in the direction of arrow b 3 ), the second cushion member  66  is withdrawn from the second removal opening  71  and the second cushion removal opening  73  as shown by arrow b 5 ; and the second cushion member  66  is removed from the space between the second pad material  62  and the second supporting member  65  provided to the seat back frame  61  ( FIG. 2 ). The second pad member  62  will collapse under the weight of the vehicle occupant M or other force applied to the seat back  36 . 
         [0057]    When the seat cushion  34  and seat back  36  collapse, the vehicle occupant M descends toward the seat cushion frame  37  by a distance Z 1  as shown by arrow b 6 , and moves back towards the seat back frame  61  by a distance of Y 1  as shown by arrow b 7 , using as a reference the position of the vehicle occupant M (chain double-dashed line) sitting in the driver seat  12  before the seat cushion  34  and seat back  36  have collapsed. Accordingly, the vehicle occupant M moves back from the inwardly pushed instrument panel  38 , steering column  31 , and steering wheel  32 ; and a space is formed between the occupant and the instrument panel  38 , steering column  31 , and steering wheel  32 . The removing of the vehicle occupant M from a space that has become cramped when a vehicle is involved in a head-on collision is accordingly facilitated. 
         [0058]    Reference is made next to  FIGS. 6A and 6B  showing the cushion member used in the cushion structure in states of being folded and partially withdrawn. 
         [0059]    In the first cushion structure  17 , when the first handle  56  is pulled toward the front right door  25  ( FIG. 1 ; in the direction of arrow b 3 ), the low-friction member (pulling belt)  81  joined to the second surface  77  of the first cushion member  47  causes the friction coefficient of the second surfaces  77  rubbing against one another to decrease. The first cushion member  47  becomes easier to withdraw, and the vehicle occupant M becomes easier to remove from a space that has become cramped after a head-on collision has occurred. 
         [0060]    The second cushion structure  18  has the same action and effect as the first cushion structure  17 . Specifically, when the second handle  74  is pulled toward the front right door  25  (in the direction of arrow b 3 ), the second cushion member  66  becomes easier to withdraw, and the operation of removing the second cushion member  66  becomes easier. 
         [0061]    In the first cushion structure  17 , the low-friction layer  52  is applied to a surface of the first supporting member  45 , which is provided to the seat cushion frame  37 , and which has the first cushion member  47  mounted thereon. Therefore, the friction coefficient of the rubbing of the first supporting member  45  and second cushion member  47  decreases, the first cushion member  47  becomes easier to withdraw, and it becomes easier to remove the vehicle occupant M from a space that has become reduced after a head-on collision. 
         [0062]    With the second cushion structure  18  as well, the low-friction member  52  applied to the second supporting member  65  makes the second cushion member  66  easier to withdraw, and facilitates the operation of removing the second cushion member  66 . 
         [0063]    The low-friction member (pulling belt)  81  can be joined to both surfaces (the first surface  76  and the second surface  77 ) of the first cushion member  47 . As a result, the friction coefficient when the first surfaces  76  rub together decreases, the first cushion member  47  becomes easier to withdraw, and the operation of removing the first cushion member  47  becomes easier still. 
         [0064]    The second cushion structure has the same action and effect as the as the first cushion structure  17 . 
         [0065]    Reference is now made to  FIGS. 7A and 7B  showing a cushion structure according to a second embodiment of the present invention. Members that are the same as in the cushion structure of the first embodiment shown in  FIGS. 1 and 2  have been given the same reference symbols, and descriptions thereof are omitted. 
         [0066]    A cushion structure  16 B of a second embodiment has a first cushion removal opening  55 B and a second cushion removal opening  73 B. 
         [0067]    The first cushion removal opening  55 B has a first fastener  91 , which is provided to the first outer member  42 , as shown in  FIG. 7A . The first fastener  91  is opened and the first handle  56  is pulled, as shown in  FIG. 7B . 
         [0068]    The second cushion removal opening  73 B has a second fastener  92 , which is provided to the second outer member  63 . The second fastener  92  is opened and the second handle  74  is pulled, as shown in  FIG. 7B . 
         [0069]    The cushion structure  16 B of the second embodiment has the same action and effect as the cushion structure of the first embodiment  16 . 
         [0070]    In the cushion structure of the second embodiment  16 B, the first cushion removal opening  55 B has the first fastener  91 ; therefore, when the first fastener  91  is closed, the first handle  56  can be stored and concealed inside the first outer member  42 . 
         [0071]    Similarly, when the second fastener  92  is closed, the second handle  74  can be stored and concealed inside the second outer member  63 . 
         [0072]    Reference is made next to  FIGS. 8A and 8B  showing a cushion structure according to a third embodiment of the present invention. Members that are the same as in the cushion structure of the first embodiment shown in  FIGS. 1 and 2  have been given the same reference symbols, and descriptions thereof have been omitted. 
         [0073]    A cushion structure  16 C of the third embodiment has a removal opening cover  94  for covering the first cushion removal opening  55 . 
         [0074]    The removal opening cover  94  is detachably latched on the seat cushion frame  37  (see  FIG. 2 ) using latching means (not shown). Using the removal opening cover  94  to cover the first cushion removal opening  55  allows the first handle  56  to be concealed. 
         [0075]    The cushion structure  16 C of the third embodiment has the same action and effect as the as the first embodiment  16 . 
         [0076]    In the cushion structure of the third embodiment, the cushion structure of the present invention is not provided to the seat back  36 ; however, the second cushion structure  18  of the first embodiment may be provided to the seat back  36 . 
         [0077]      FIGS. 9A and 9B  show a cushion structure of a fourth embodiment. Members that are the same as in the cushion structure of the first embodiment shown in  FIGS. 1 and 2  have been given the same reference symbols, and descriptions thereof have been omitted. 
         [0078]    In the cushion structure  16 D of the fourth embodiment, a second cushion removal opening  73 D is provided to a seat back  36 D of the driver seat  12 . 
         [0079]    The seat back  36 D has a side air bag  96 . The side airbag  96  is of an existing type; and comprises an inflator (gas generator; not shown) for filling an airbag  97  ( FIG. 9B ) with gas, a control unit (not shown) for operating the inflator, a storage part  101  in which the airbag  97  is folded and stored, and a cover part  102  for closing the storage part  101 . 
         [0080]    The inflator operates in the same manner as existing inflators; however, an operating switch  103  is provided on the driver seat  12 . The inflator is operated via the control unit based on information that the operating switch  103  has been activated, and the airbag  97  deploys. 
         [0081]    The control unit performs a control to activate the inflator based on two types of information: information that the operating switch  103  has been activated and information that a head-on collision has occurred. In other words, it is only when the air bag provided to the steering wheel  32  ( FIG. 1 ) has already been activated (when a head-on collision is judged to have occurred) that the control device activates the inflator based on information that the operating switch  103  has been activated. 
         [0082]    The second cushion removal opening  73 D is formed from a bursting part  104  of the second outer member  63 , the bursting part  104  being burst by the cover part  102  of the side airbag  96 . The second handle  74  is disposed on the outer side of the storage part  101 . 
         [0083]    The cushion structure  16 D of the fourth embodiment has the same action and effect as the as the cushion structure of the first embodiment  16 . 
         [0084]    When the vehicle  11  shown in  FIG. 1  is involved in a head-on collision, the control unit performs a control to activate the airbag of the steering wheel  32  based on information that a head-on collision has occurred, as received from an existing vehicle state detecting sensor (not shown). When the vehicle  11  is in the state shown in  FIG. 4 , and a rescuer turns on the operating switch  103  provided to the driver seat  12 , the inflator is activated, and the airbag  97  starts to fill with gas, opening the cover part  102 . The second outer member  63  is burst by the cover part  102 , and the burst part  104  (second cushion removal opening  73 D) is formed. As a result, the second handle  74  can be withdrawn via the burst part  104  (second cushion removal opening  73 D). 
         [0085]    In other words, in a normal mode, the second handle  74  is stored inside the second outer member  63  and is concealed so as to be invisible from the outside. 
         [0086]    The cushion structure  16  of the first embodiment comprises the first cushion structure  17  and the second cushion structure  18 , but may comprise merely the cushion structure  17  or the second cushion structure  18 . 
         [0087]    The first through fourth embodiments may be combined unrestrictedly in the cushion structure. For example, the first cushion removal opening  55 B (see  FIG. 7A ) of the second embodiment can be provided to the seat cushion  34 , and the second cushion removal opening  73 B (see  FIG. 9A ) of the fourth embodiment can be provided to the seat back  36 . 
         [0088]    The first supporting member  45  and the second supporting member  65  both have flat surfaces in the vehicle seat cushion structure of the present invention, but may also have a slatted, latticed, or net-shaped form. 
         [0089]    Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.