Patent Publication Number: US-2022227269-A1

Title: Conveyance seat

Description:
TECHNICAL FIELD 
     The present invention relates to a conveyance seat, particularly to a conveyance seat capable of absorbing an impact to be applied to a seated occupant when an impact such as a collision is generated. 
     BACKGROUND ART 
     When a traveling vehicle undergoes a frontal collision, a submarine phenomenon may occur in which the body of a seated occupant (occupant) seated in a seat slides forward and downward on the surface of the seat in a state where the body of the seated occupant is constrained by a seat belt. As a measure to suppress the submarine phenomenon, for example, as described in PATENT LITERATURE 1, a vehicle seat is known in which a cross member is placed along a lateral width direction of a seat cushion in a middle portion of a frame part of the seat cushion in a front to back direction, and in which a foldable portion can be stretched to suppress a forward movement of an occupant when the buttocks of the occupant tend to move forward during sudden deceleration. 
     CITATION LIST 
     Patent Literature 
     PATENT LITERATURE 1: JP 2002-46513 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the vehicle seat described in PATENT LITERATURE 1, since the cross member as an impact absorbing member is placed on a seat cushion frame, specifically, on seat cushion side frames, an increase in the width of the seat cushion frame is required. 
     The present invention is conceived in light of the above problem, and an object of the present invention is to provide a conveyance seat in which an increase in size is suppressed while an impact to be applied to a seated occupant when an impact such as a collision is generated is properly absorbed. 
     Solution to Problem 
     In order to solve the above problem, according to an aspect of the present invention, there is provided a conveyance seat including a seat cushion. The seat cushion includes a seat cushion frame including a pair of side frames provided to be separated from each other in a width direction of the conveyance seat, a seat cushion pad placed on the seat cushion frame, and an impact absorbing member provided below the seat cushion pad. The impact absorbing member is disposed between the pair of side frames in the width direction of the conveyance seat. The impact absorbing member is provided with a cavity portion. The impact absorbing member is supported from below by a support member. 
     In the seat cushion of the present invention configured as described above, since the impact absorbing member is supported from below by the support member, an impact absorption effect is stably displayed while an increase in size is suppressed. 
     In addition, in the above configuration, apart of a lower surface of the impact absorbing member may be accommodated in a recessed portion of the support member. 
     In the above configuration, since a part of the lower surface of the impact absorbing member is accommodated in the recessed portion of the support member, the position of the impact absorbing member is stable. 
     In addition, in the above configuration, a lower surface of the impact absorbing member may be disposed at a position clear of a bent portion of the support member. 
     In the above configuration, since the impact absorbing member is disposed at a position clear of the bent portion of the support member, an impact is to be stably absorbed. 
     In addition, in the above configuration, a part of an upper surface of the impact absorbing member may be accommodated in a pad recessed portion of the seat cushion pad. 
     In the above configuration, since a part of the upper surface of the impact absorbing member is accommodated in the pad recessed portion of the seat cushion pad, the position of the impact absorbing member is stable. 
     In addition, in the above configuration, the impact absorbing member may be disposed behind a sinking suppression member extending in the width direction of the conveyance seat. 
     In the above configuration, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the sinking suppression member such as a submarine pipe is suppressed. 
     In addition, in the above configuration, a plate-shaped member may be provided at a position facing an upper surface of the impact absorbing member. 
     In the above configuration, since the plate-shaped member is provided on the upper surface of the impact absorbing member, a load of an occupant is to be stably transmitted to the impact absorbing member. 
     In addition, in the above configuration, a metal member may not be disposed between an upper surface of the impact absorbing member and the seat cushion pad. 
     In the above configuration, since a metal member is not disposed between the impact absorbing member and the seat cushion pad above the impact absorbing member, a load of an occupant is to be stably transmitted to the impact absorbing member. 
     In addition, in the above configuration, the seat cushion pad may be covered with a skin material, and the cavity portion of the impact absorbing member may be disposed at a position clear of a pull-in portion of the skin material. 
     In the above configuration, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the pull-in portion is suppressed. 
     In addition, in the above configuration, the seat cushion may include a sensor member, and the cavity portion of the impact absorbing member may be disposed at a position clear of the sensor member. 
     In the above configuration, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the sensor member is suppressed. 
     In addition, in the above configuration, the cavity portion of the impact absorbing member may be formed as a recessed portion, and the recessed portion may be provided to extend in a vertical direction. 
     In the above configuration, since an extending direction of the recessed portion of the impact absorbing member is aligned along a load input direction from an occupant, an impact absorption effect is much more stably displayed. 
     In addition, in the above configuration, the cavity portion of the impact absorbing member may be formed as a recessed portion, and the recessed portion may have an opening in a lower surface of the impact absorbing member. 
     In the above configuration, since an opening is formed in the lower surface of the impact absorbing member, a load from an upper surface is to be stably received. Hence, the load is to be stably transmitted to the impact absorbing member. 
     In addition, in the above configuration, the cavity portion of the impact absorbing member may be formed as a recessed portion, a part of an upper surface of the impact absorbing member may be accommodated in a pad recessed portion of the seat cushion pad, and at least a part of the cavity portion of the impact absorbing member in an up to down direction of the conveyance seat may be disposed at the same height position as a position of the pad recessed portion. 
     In the above configuration, since the cavity portion of the impact absorbing member is at the same height position (in the same horizontal plane) as the position of the pad recessed portion, a portion of the impact absorbing member surrounded by the pad recessed portion is protected in a horizontal direction. 
     In addition, in the above configuration, the seat cushion frame may be made of a resin material, and the impact absorbing member may be surrounded by the seat cushion frame in a front to back direction of the conveyance seat and in the width direction of the conveyance seat. 
     In the above configuration, since the impact absorbing member is surrounded by the seat cushion frame made of resin, the positioning of the impact absorbing member is facilitated. 
     Advantageous Effects of Invention 
     According to the conveyance seat of the present invention, since the impact absorbing member is supported from below by the support member, an impact absorption effect is stably displayed while an increase in size is suppressed. 
     In addition, according to the conveyance seat of the present invention, since a part of the lower surface of the impact absorbing member is accommodated in the recessed portion of the support member, the position of the impact absorbing member is stable. 
     In addition, according to the conveyance seat of the present invention, since the impact absorbing member is disposed at a position clear of the bent portion of the support member, an impact is to be stably absorbed. 
     In addition, according to the conveyance seat of the present invention, since a part of the upper surface of the impact absorbing member is accommodated in the pad recessed portion of the seat cushion pad, the position of the impact absorbing member is stable. 
     In addition, according to the conveyance seat of the present invention, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the sinking suppression member such as a submarine pipe is suppressed. 
     In addition, according to the conveyance seat of the present invention, since the plate-shaped member is provided on the upper surface of the impact absorbing member, a load of an occupant is to be stably transmitted to the impact absorbing member. 
     In addition, according to the conveyance seat of the present invention, since a metal member is not disposed between the impact absorbing member and the seat cushion pad above the impact absorbing member, a load of an occupant is to be stably transmitted to the impact absorbing member. 
     In addition, according to the conveyance seat of the present invention, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the pull-in portion is suppressed. 
     In addition, according to the conveyance seat of the present invention, when a load during impact absorption is transmitted to the impact absorbing member, an influence of the sensor member is suppressed. 
     In addition, according to the conveyance seat of the present invention, since the extending direction of the recessed portion of the impact absorbing member is aligned along the load input direction from an occupant, an impact absorption effect is much more stably displayed. 
     In addition, according to the conveyance seat of the present invention, since an opening is formed in the lower surface of the impact absorbing member, a load from the upper surface is to be stably received. Hence, the load is to be stably transmitted to the impact absorbing member. 
     In addition, according to the conveyance seat of the present invention, since the cavity portion of the impact absorbing member is at the same height position (in the same horizontal plane) as the position of the pad recessed portion, the portion of the impact absorbing member surrounded by the pad recessed portion is protected in the horizontal direction. 
     In addition, according to the conveyance seat of the present invention, since the impact absorbing member is surrounded by the seat cushion frame made of resin, the positioning of the impact absorbing member is facilitated. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is an exterior view of a vehicle seat according to first and second embodiments of the present invention. 
         FIG. 1B  is an exterior view of the vehicle seat according to the first embodiment of the present invention. 
         FIG. 2  is a cross-sectional view taken along line A-A in  FIG. 1 , and describing a structure around an impact absorbing member provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 3A  is an exterior view of the impact absorbing member provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 3B  is a schematic view illustrating an internal structure of the impact absorbing member provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 3C  is a schematic view illustrating the internal structure of the impact absorbing member provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 4A  is a schematic view illustrating a positional relationship between the impact absorbing member and a pull-in portion of a skin material provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 4B  is a schematic view illustrating a positional relationship between the impact absorbing member and a sensor member provided in the vehicle seat according to the first embodiment of the present invention. 
         FIG. 5  is an exploded view illustrating a configuration of a seat cushion of the vehicle seat according to the second embodiment of the present invention. 
         FIG. 6A  is an exterior view illustrating a configuration of a seat cushion frame made of resin that is provided in the seat cushion of the vehicle seat according to the second embodiment of the present invention. 
         FIG. 6B  is a cross-sectional view taken along line B-B in  FIG. 6A , and describing the configuration of the seat cushion frame made of resin that is provided in the seat cushion of the vehicle seat according to the second embodiment of the present invention. 
         FIG. 7A  is a top view of the seat cushion of the vehicle seat according to the second embodiment of the present invention. 
         FIG. 7B  is a cross-sectional view taken along line C-C in  FIG. 7A , and describing the configuration of the seat cushion of the vehicle seat according to the second embodiment of the present invention. 
         FIG. 8A  is a schematic cross-sectional view of an impact absorbing member according to a first modification example. 
         FIG. 8B  is a schematic cross-sectional view of the impact absorbing member according to the first modification example. 
         FIG. 8C  is a schematic cross-sectional view of the impact absorbing member according to the first modification example. 
         FIG. 9  is a description view illustrating a structure around the impact absorbing member provided in the vehicle seat according to the first modification example of the present invention, and corresponding to a cross-sectional view taken along line A-A in  FIG. 1 . 
         FIG. 10  is a schematic cross-sectional view illustrating a positional relationship between the impact absorbing member and a seat cushion pad according to the first modification example. 
         FIG. 11  is a schematic cross-sectional view illustrating the impact absorbing member and a support member according to the first modification example. 
         FIG. 12  is a schematic cross-sectional view illustrating a positional relationship between the impact absorbing member and a blower or a wire frame according to the first modification example. 
         FIG. 13  is a schematic view illustrating a positional relationship between the impact absorbing member and a harness or an application region of an abnormal noise inhibitor according to the first modification example. 
         FIG. 14  is a schematic cross-sectional view illustrating the positional relationship between the impact absorbing member and the harness according to the first modification example. 
         FIG. 15  is a schematic partial cross-sectional view of an impact absorbing member according to a second modification example. 
         FIG. 16  is a schematic partial cross-sectional view of the impact absorbing member according to the second modification example. 
         FIG. 17A  is an exterior view of an impact absorbing member according to a third modification example. 
         FIG. 17B  is a schematic view illustrating an internal structure of the impact absorbing member according to the third modification example. 
         FIG. 18A  is an exterior view of the impact absorbing member according to the third modification example. 
         FIG. 18B  is a schematic view illustrating the internal structure of the impact absorbing member according to the third modification example. 
         FIG. 19  is an exploded view illustrating a configuration of an impact absorbing portion according to another embodiment of the present invention. 
         FIG. 20  is a schematic view illustrating a configuration of an impact absorbing device according to another embodiment of the present invention. 
         FIG. 21  is a schematic view illustrating a state where the impact absorbing device according to another embodiment of the present invention is applied to a vehicle seat. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereafter, a conveyance seat according to first and second embodiments of the present invention (hereafter, referred to as the present embodiment) will be described with reference to  FIGS. 1 to 21 . As an example of the conveyance seat according to the present embodiment, a vehicle rear seat to be mounted in vehicles will be described; however, the conveyance seat is not limited to a vehicle rear seat to be mounted in ground travel conveyances with wheels such as automobiles or railway vehicles, and may be a vehicle front seat, a second row seat of a three-row seat, or a seat to be mounted in aircrafts, ships, etc. that move in regions other than the ground. 
     Incidentally, the embodiments to be described below are merely one example provided to facilitate understanding of the present invention, and do not limit the present invention. Namely, the shapes, dimensions, dispositions, etc. of members to be described below can be changed or improved without departing from the concept of the present invention, and it goes without saying that the present invention includes equivalents thereof. 
     Regarding terms indicating directions in the specification, each direction is defined as in  FIG. 1 . Specifically, in the following description, a “front to back direction” means a front to back direction when viewed from a seated occupant of a vehicle seat, and is a direction aligned with a travel direction of a vehicle. A “seat width direction” means a lateral width direction of the vehicle seat, and is aligned with a right to left direction when viewed from the seated occupant of the vehicle seat. In addition, an “up to down direction” means a height direction of the vehicle seat, and is aligned with an up to down direction of the vehicle seat when viewed from the front. 
     1. CONFIGURATION OF VEHICLE SEAT S 
     A vehicle seat S according to the present embodiment has an appearance illustrated in  FIG. 1A . Incidentally, in  FIG. 1A , for convenience of illustration, a part of the vehicle seat S (specifically, front end corner of a seat cushion S 1 ) is illustrated with a trim cover S 12  removed therefrom. 
     The vehicle seat S includes, as main components, the seat cushion S 1  serving as a seating portion that supports the buttocks of a seated occupant, a seat back S 2  serving as a backrest portion that supports the back of the seated occupant, and a headrest S 3  that is disposed in an upper portion of the seat back S 2  to support the head of the seated occupant. 
     The seat cushion S 1  is formed by placing a seat cushion pad S 11  on a seat cushion frame that is a skeleton, and covering the seat cushion pad S 11  with the trim cover S 12 . As illustrated in  FIG. 1B , the seat cushion frame includes a seat cushion side frame S 14 . The seat back S 2  is formed by placing a cushion pad (not illustrated) on a seat back frame (not illustrated), and covering the cushion pad with the trim cover S 12 . The headrest S 3  is formed by disposing a pad material (not illustrated) on a core (not illustrated), and covering the pad material with the trim cover S 12 . 
     The seat cushion pad S 11  of the seat cushion S 1  or the seat back pad of the seat back S 2  is a urethane base material molded by foam molding using a urethane foam material. The trim cover S 12  of the seat cushion S 1  is provided with a first pull-in portion T 1  (right pull-in portion) provided on a right side of the seat cushion to extend in the front to back direction, a second pull-in portion T 2  (left pull-in portion) provided on a left side of the seat cushion to extend in the front to back direction, and a third pull-in portion T 3  (rear pull-in portion) provided on a rear side of the seat cushion to extend in the seat width direction. In addition, a thin portion formed to have a thinner thickness than those of regions therearound is provided at a position corresponding to each of the pull-in portions T 1  to T 3  of the seat cushion pad S 11 . 
     2. SEAT CUSHION OF FIRST EMBODIMENT 
     A configuration of the seat cushion S 1  of the vehicle seat S according to the first embodiment of the present invention will be described with reference to  FIGS. 2 to 4B . Incidentally, in  FIG. 2 , the illustration of the trim cover S 12  is omitted. As illustrated in a cross-sectional view of  FIG. 2  taken along line A-A in  FIG. 1A , an impact absorbing member  20  is provided below the seat cushion pad S 11 . As illustrated in  FIGS. 2 to 3B , a cavity portion  23  is provided, as a through-hole, between an upper surface  21  and a lower surface  22  in the impact absorbing member  20 . An inclined surface  21   a  that is inclined downward as extending backward is formed in the upper surface  21  of the impact absorbing member  20 . 
     The impact absorbing member  20  is disposed inward from a pair of the seat cushion side frames S 14  provided to be separated from each other in the seat width direction ( FIG. 1B ). In more detail, the impact absorbing member  20  is disposed below the seat cushion pad S 11  at a substantially center position between the pair of seat cushion side frames S 14  in the seat width direction ( FIG. 1B ). The impact absorbing member  20  is, for example, a urethane molded part, has a higher hardness than that of the seat cushion pad S 11  that is a urethane pad, and includes the cavity portion  23  that is to be crushed to absorb an impact when a certain load value is exceeded. 
     The impact absorbing member  20  is surface supported from below by a plate-shaped member  10  that is a support member. The plate-shaped member  10  is a plate-shaped member forming a floor that supports a vehicle rear seat from below, and a recessed portion  11  that is recessed downward in the vicinity of the thighs of the occupant is formed therein. In addition, a protrusion portion  12  protruding upward with respect to the recessed portion  11  is formed at a front end of the plate-shaped member  10 . 
     Since the lower surface  22  of the impact absorbing member  20  is surface supported from below by the plate-shaped member  10  that is a support member, an impact absorption effect is stably displayed. At this time, since at least a part of the lower surface  22  of the impact absorbing member  20  is accommodate in the recessed portion  11  of the plate-shaped member  10 , the position of the impact absorbing member  20  with respect to the plate-shaped member  10  becomes stable. 
     As illustrated in  FIG. 2 , the impact absorbing member  20  is disposed between a front bent portion  13   a  and a rear bent portion  13   b  in a seat front to back direction. The front bent portion  13   a  is bent upward to form a front end of the recessed portion  11 , and the rear bent portion  13   b  is bent upward to form a rear end of the recessed portion  11 . 
     As illustrated in  FIG. 2 , a pad recessed portion S 11   b  that is recessed upward is formed in a lower surface S 11   a  of the seat cushion pad S 11 . Since at least a part of the upper surface  21  of the impact absorbing member  20  is accommodated in the pad recessed portion S 11   b  of the seat cushion pad S 11 , the position of the impact absorbing member  20  with respect to the seat cushion pad S 11  becomes stable. 
     The protrusion portion  12  protruding upward extends in the seat width direction, and functions as a sinking suppression member that suppresses a submarine phenomenon in which the body of the seated occupant seated in the vehicle seat S slides forward and downward when the vehicle undergoes a frontal collision. Since the impact absorbing member  20  is disposed behind the protrusion portion  12  extending in the seat width direction, an influence of the protrusion portion  12  is suppressed when a load during impact absorption is transmitted to the impact absorbing member  20 . Incidentally, the sinking suppression member may be a pipe member (for example, submarine pipe) extending in the seat width direction in the vicinity of a front end of the seat. 
     In addition, a metal member such as a seat frame member is not disposed between the upper surface  21  of the impact absorbing member  20  and the lower surface S 11   a  of the seat cushion pad S 11 . Since a metal member is not disposed between the impact absorbing member  20  and the seat cushion pad S 11  above the impact absorbing member  20 , a load of the occupant is to be stably transmitted to the impact absorbing member  20 . 
     As illustrated in  FIGS. 3A and 3B , since the cavity portion  23  of the impact absorbing member  20  is formed as a through-hole (recessed portion penetrating through the impact absorbing member  20  from the upper surface  21  to the lower surface  22 ) having a circular cylindrical shape, and has no corners, the modability (shape) of the impact absorbing member  20  is stable. Hence, an impact absorption effect becomes more stable. 
     In this case, in the impact absorbing member  20 , the surface area of an opening of the cavity portion  23  in the upper surface  21  may be larger than ⅓ of the total surface area of the upper surface  21 , and the surface area of an opening of the cavity portion  23  in the lower surface  22  may be larger than ⅓ of the total surface area of the lower surface  22 . As described above, when the cavity portion  23  is formed as a through-hole, and the area of the opening thereof is set larger than ⅓ of the total surface area of the upper surface  21  or the lower surface  22 , the setting of an impact absorption load becomes stable. 
     In addition, since the cavity portion  23  (recessed portion penetrating through the impact absorbing member  20  from the upper surface  21  to the lower surface  22 ) of the impact absorbing member  20  is provided to extend in a vertical direction, and is aligned along a load input direction (namely, an up to down direction of the vehicle seat S) from the occupant, an impact absorption effect is much more stably displayed. 
     Incidentally, as illustrated in  FIG. 3C , the cavity portion  23  of the impact absorbing member  20  may be provided to extend in a state where the cavity portion  23  is inclined from the vertical direction and to extend. Specifically, the cavity portion  23  may be inclined from a rear side toward a front side as extending from an upper side toward a lower side. According to such a configuration, the cavity portion  23  is much more aligned with the load input direction from the occupant, so that an impact absorption effect is more stably displayed. 
     In addition, the cavity portion  23  of the impact absorbing member  20  is a circular cylindrical through-hole. The shape of an end portion of the cavity portion  23  in the upper surface  21  or the lower surface  22  is preferably a circular shape, and may be a perfect circular shape or an elliptical shape. 
     The seat cushion pad S 11  is covered with the trim cover S 12  as a skin material, and as illustrated in  FIG. 4A , the impact absorbing member  20  and the cavity portion  23  are disposed at a position clear of each of the pull-in portions T 1  to T 3  of the trim cover S 12 . Specifically, in a top view of the seat cushion S 1 , the impact absorbing member  20  and the cavity portion  23  are disposed between the first pull-in portion T 1  (right pull-in portion) and the second pull-in portion T 2  (left pull-in portion) in the seat width direction, and are disposed in front of the third pull-in portion T 3  (rear pull-in portion) in the seat front to back direction. According to such a configuration, when a load during impact absorption is transmitted to the impact absorbing member  20 , an influence of each of the pull-in portions T 1  to T 3  is suppressed. 
     In addition, as illustrated in  FIG. 4B , the seat cushion S 1  includes a sensor member S 13  that detects a state of the seated occupant, and the cavity portion  23  of the impact absorbing member  20  is disposed at a position clear of the sensor member S 13 . Specifically, in a top view of the seat cushion S 1 , the impact absorbing member  20  and the cavity portion  23  are disposed between a first sensor portion S 13   a  (right sensor portion) and a second sensor portion S 13   b  (left sensor portion) in the seat width direction, and are disposed in front of a rear portion of a third sensor portion S 13   c  (rear sensor portion) in the seat front to back direction. According to such a configuration, when a load during impact absorption is transmitted to the impact absorbing member  20 , an influence of the sensor member S 13  (each of the sensor portions S 13   a  to S 13   c ) is suppressed. 
     3. SEAT CUSHION OF SECOND EMBODIMENT 
     A configuration of a seat cushion S 1 X of the vehicle seat according to the second embodiment of the present invention will be described with reference to  FIGS. 5 to 7B . As illustrated in  FIG. 5 , the seat cushion S 1 X is formed by placing a seat cushion pad S 11 X on a seat cushion frame S 14 X made of resin that is a skeleton, and covering the seat cushion pad S 11 X with a trim cover S 12 X. 
     As illustrated in  FIGS. 6A and 6B , the seat cushion frame S 14 X includes a recessed portion S 14 Xa recessed downward. The recessed portion S 14 Xa is formed such that the height in the up to down direction decreases gradually from the front side as the recessed portion S 14 Xa extends backward (the depth of the recessed portion decreases gradually). 
     The recessed portion S 14 Xa includes a bottom surface S 14 Xb. As illustrated in  FIG. 6A , the recessed portion S 14 Xa has a width for one occupant, and is disposed between a pair of seat cushion side frames S 14 Xc provided to be separated from each other in the seat width direction. 
     As illustrated in  FIGS. 7A and 7B , the recessed portion S 14 Xa accommodates an impact absorbing member  20 X, and a lower surface  22 X of the impact absorbing member  20 X is surface supported from below by the bottom surface S 14 Xb. Namely, the seat cushion frame S 14 X has the role of a support member that surface supports the impact absorbing member from below. 
     As illustrated in  FIGS. 7A and 7B , the impact absorbing member  20 X is surrounded by the seat cushion frame S 14 X in the seat front to back direction and in the seat width direction. Therefore, the positioning of the impact absorbing member  20 X in the seat cushion SIX (in other words, the positioning of the impact absorbing member  20 X with respect to the seat cushion frame S 14 X) is facilitated. 
     In the seat cushion SIX of the vehicle seat according to the second embodiment, the entirety of the seat cushion frame S 14 X may be fabricated as a blow molded part and the recessed portion S 14 Xa is provided in a region in which an impact is desired to be absorbed. In addition, the outer shape of the seat cushion frame S 14 X may be formed from foamed polypropylene (EPP), and the impact absorbing member  20 X that is a blow molded part maybe disposed in the recessed portion S 14 Xa. In addition, the outer shape of the seat cushion frame S 14 X as a blow molded part may be formed, and the impact absorbing member  20 X that is a urethane molded part maybe disposed in the recessed portion S 14 Xa. 
     4. FIRST MODIFICATION EXAMPLE 
     The present invention is not limited to the above embodiments. Hereinafter, a first modification example of the impact absorbing member and the seat cushion according to the present embodiment will be described with reference to  FIGS. 8A to 14 . 
     An impact absorbing member  20 A illustrated in  FIG. 8A  is a urethane molded part, and a cavity portion  23 A is formed as recessed portion including a closed surface in a direction of an upper surface  21 A. In the impact absorbing member  20 A, since an opening of the cavity portion  23 A is not provided in the upper surface  21 A, and an opening thereof is formed in a lower surface  22 A, a load from the upper surface  21 A is to be stably received. Hence, the load from the occupant is to be stably transmitted to the impact absorbing member  20 A. In addition, since the cavity portion  23 A is provided to extend in the vertical direction, and an extending direction of the recessed portion is aligned along the load input direction from the occupant, an impact absorption effect is much more stably displayed. 
     In addition, contrary to the example illustrated in  FIG. 8A , the cavity portion  23 A may be formed as a recessed portion including a closed surface in a direction of the lower surface  22 A, and in such a case, the lower surface  22 A of the impact absorbing member  20  is stably disposed with respect to a support member such as the plate-shaped member  10 . 
     An impact absorbing member  20 B and an impact absorbing member  20 C illustrated in  FIGS. 8B and 8C  are blow molded parts made of resin, and the outer shape thereof or the numbers or disposition of recessed portions  23 B and  23 C can be appropriately set to adjust a load value when the impact absorbing members  20 B and  20 C are crushed to absorb an impact. 
     In addition, a plate-shaped member (not illustrated) may be provided at a position facing each of upper surfaces  21 A,  21 B, and  21 C of the impact absorbing members  20 A,  20 B, and  20 C. According to such a configuration, a load of the occupant is to be stably transmitted to each of the impact absorbing members  20 A,  20 B, and  20 C via the plate-shaped member. 
     In addition, as illustrated in  FIG. 9 , the plate-shaped member  10  may include the rear bent portion  13   b  that is bent gradually downward from the front side toward the rear side. In this case, the lower surface  22  of the impact absorbing member  20  may be disposed at a position clear of the bent portions (the front bent portion  13   a  and the rear bent portion  13   b ). Specifically, the lower surface  22  of the impact absorbing member  20  may be disposed behind the front bent portion  13   a  and in front of the rear bent portion  13   b  in the seat front to back direction. Since the impact absorbing member  20  is disposed at a position clear of the bent portions (the front bent portion  13   a  and the rear bent portion  13   b ) of the plate-shaped member  10  as a support member, an impact is to be stably absorbed. 
     In addition, as illustrated in a schematic cross-sectional view of  FIG. 10  (vertical cross-sectional view of the seat cushion S 1 ), at least a part of the upper surface  21  of the impact absorbing member  20  may be accommodated in the pad recessed portion S 11   b  of the seat cushion pad S 11 , and at least a part of the cavity portion  23  of the impact absorbing member  20  in a seat up to down direction may be disposed at the same height position as the position of the pad recessed portion S 11   b  (illustrated by an alternate long and short dash line in  FIG. 10 ). According to such a configuration, a portion of the impact absorbing member  20  surrounded by the pad recessed portion S 11   b  is protected in a horizontal direction. 
     In addition, the pad recessed portion S 11   b  of the seat cushion pad S 11  and the cavity portion  23  of the impact absorbing member  20  are disposed clear of a position at which the pad recessed portion S 11   b  and the cavity portion  23  are in the same plane, in other words, the cavity portion  23  of the impact absorbing member  20  may be disposed at a height position different from that of the pad recessed portion S 11   b  in the seat up to down direction. According to such a configuration, a load can be more stably received inside the pad recessed portion S 11   b.    
     In the above embodiments, the case where the support member is the plate-shaped member  10  forming the floor that supports the vehicle rear seat from below, or the case where the support member is the seat cushion frame S 14 X made of resin has been illustrated as an example; however, the support member may be a pan frame provided in the seat cushion frame. 
     In addition, in the above embodiments, when the cavity portion of the impact absorbing member is formed as a recessed portion, an inclination angle may be given to form a wide opening in the lower surface. Since the inclination angle is given to form a wide opening in the lower surface, the area of an upper surface which receives a load increases. Hence, the load can be stably received. 
     In addition, in the above embodiments, when the cavity portion of the impact absorbing member is formed as a recessed portion, an inclination angle may be given to form a wide opening in the upper surface. Since the inclination angle is given to form a wide opening in the upper surface, the lower surface of the impact absorbing member is stably disposed on a support member such as a plate-shaped member. 
     In addition, in the above embodiments, the cavity portion  23  of the impact absorbing member  20  is formed as a circular cylindrical through-hole ( FIGS. 3A and 3B ), but the through-hole can also have a square cylindrical shape. When the shape of the through-hole is a square cylindrical shape, the surface area of the opening in the upper surface  21  or the lower surface  22  can be set wider than in the case of a circular cylindrical shape. 
     In the above embodiments and the modification example, since a urethane molded part or a blow molded part made of resin that is lighter than one made of metal is used as the impact absorbing member, impact absorbability is improved while the weight is reduced. 
     In the above embodiments and the modification example, the support member is the plate-shaped member  10  or the seat cushion frame S 14 X; however, the support member is not limited as long as the support member is capable of supporting the impact absorbing member  20  from below. For example, when the support member is the plate-shaped member  10 , a pan frame provided in the seat cushion frame, a resin plate as a pressure-receiving member, a wooden plate, etc. can be used as the support member. 
     In addition, as long as the support member is capable of supporting the impact absorbing member  20  from below, the support member is not limited to a plate-shaped member that surface supports the impact absorbing member  20  from below. For example, as illustrated in  FIG. 11 , a support member  10 Y that supports the impact absorbing member  20  from below may be a pressure-receiving member formed of a linear member such as an S spring or a wire, or may be a cloth-shaped support member. 
     A metal member is not disposed between the upper surface  21  of the impact absorbing member  20  and the seat cushion pad S 11 . Specifically, as illustrated in  FIG. 12 , the impact absorbing member  20  is disposed clear of a wire frame WF as a metal member. In detail, the impact absorbing member  20  is disposed at a position different from that of the wire frame WF in the seat front to back direction. Namely, the wire frame WF is not disposed above the impact absorbing member  20 . 
     In addition, as illustrated in  FIG. 12 , the impact absorbing member  20  maybe disposed clear of a position at which the impact absorbing member  20  overlaps a blower B in the seat up to down direction, the blower B being an air blowing device provided below the plate-shaped member  10  (protrusion portion  12  as a pan frame). Specifically, as illustrated in  FIG. 12 , the impact absorbing member  20  is disposed clear of the blower B. In detail, the impact absorbing member  20  is disposed at a position different from that of the blower B in the seat front to back direction. Namely, the blower B is not disposed above or below the impact absorbing member  20 . A space at a location where the blower B is disposed is narrowed in the seat up to down direction (height direction), and according to such a configuration, a space in which the impact absorbing member  20  is disposed can be widened. 
     In addition, as illustrated in  FIGS. 13 and 14 , the impact absorbing member  20  maybe disposed clear of a harness H disposed in the lower surface S 11   a  of the seat cushion pad S 11 . Namely, the harness His not disposed above or below the impact absorbing member  20 . Here, the harness H is to be connected to a seat heater, a sensor, etc. (not illustrated). According to such a configuration, interference of the impact absorbing member  20  with the harness H is suppressed. 
     In addition, as illustrated in  FIG. 13 , the impact absorbing member  20  may be disposed clear of an application region N of an abnormal noise inhibitor in the lower surface S 11   a  (back surface) of the seat cushion pad S 11 . Here, the abnormal noise inhibitor is a material that suppresses sound to be generated when a urethane form forming the seat cushion pad S 11  and a metal frame member come into contact with each other to rub against each other. According to such a configuration, an influence of the application region N of the abnormal noise inhibitor on the impact absorbing member  20  is suppressed, the abnormal noise inhibitor facilitating slippage. 
     5. SECOND MODIFICATION EXAMPLE 
     The present invention is not limited to the above embodiments. Hereinafter, a second modification example of the impact absorbing member and the seat cushion according to the present embodiment will be described with reference to  FIGS. 15 and 16 . In the following description, differences from the above embodiments will be mainly described. 
     An impact absorbing member  220  and an impact absorbing member  220 X are blow molded parts made of resin, and the outer shape thereof or the number or disposition of recessed portions (cavity portions) can be appropriately set to adjust a load value when the impact absorbing members  220  and  220 X are crushed to absorb an impact. 
     As illustrated in  FIG. 15 , the impact absorbing member  220  includes a first recessed portion  221   b  provided to have an opening in an upper surface  221 , and a second recessed portion  222   b  provided to have an opening in a lower surface  222 . Here, the first recessed portion  221   b  and the second recessed portion  222   b  has a shape having rounded corners. 
     In addition, the first recessed portion  221   b  and the second recessed portion  222   b  are provided at positions clear of an outer wall portion of the impact absorbing member  220 . In other words, the first recessed portion  221   b  and the second recessed portion  222   b  are provided at positions between a front end and a rear end of the impact absorbing member  220  and between right and left end portions (side walls) in the seat width direction. 
     The first recessed portion  221   b  is provided with a first bottom surface  221   c  between the upper surface  221  and the lower surface  222 . The second recessed portion  222   b  is provided with a second bottom surface  222   c  between the upper surface  221  and the lower surface  222 . As illustrated in  FIG. 15 , the first bottom surface  221   c  and the second bottom surface  222   c  are in contact with each other in the up to down direction. Since the first bottom surface  221   c  and the second bottom surface  222   c  are in contact with each other, the thickness of a bottom surface portion in the recessed portion is increased, and rigidity is improved. Hence, an impact absorption efficiency is improved. 
     Incidentally, as illustrated in  FIG. 16 , the first bottom surface  221   c  and the second bottom surface  222   c  may be separated from each other in the up to down direction, and a gap  223   c  (space portion) may be formed between the first bottom surface  221   c  and the second bottom surface  222   c.  Since the first bottom surface  221   c  and the second bottom surface  222   c  are separated from each other in the up to down direction to form the gap  223   c  (space portion), the gap  223   c  as a space portion functions as an elastic deformable region to facilitate the adjustment of impact absorption. 
     As illustrated in  FIGS. 15 and 16 , the impact absorbing member  220  has a hollow structure. A front space  223   a  is formed on a front side, and a rear space  223   b  is formed on a rear side. In this case, when the rear space  223   b  is formed to have a larger volume than that of the front space  223   a,  impact absorbability is increased on the rear side on which an impact to be applied increases, which is preferable. Incidentally, the rear space  223   b  may be formed to have a smaller volume than that of the front space  223   a.    
     Similarly to the impact absorbing member  20  in  FIG. 1B , the impact absorbing member  220  is disposed between the pair of seat cushion side frames S 14  in the seat width direction. Namely, the first recessed portion  221   b  and the second recessed portion  222   b  are provided in a seating portion of the occupant. 
     It is preferable that the impact absorbing member  220  is disposed at the same position as that of the impact absorbing member  20  in  FIG. 4A , and that the first recessed portion  221   b  and the second recessed portion  222   b  are provided between a center of the seating portion and a skin pull-in portion (the first pull-in portion T 1  or the second pull-in portion T 2 ) in the seat width direction. 
     As described above, the second modification example of the impact absorbing member and the seat cushion according to the present embodiment includes the following technical concept. 
     [1] The vehicle seat S (conveyance seat) includes the seat cushion S 1 . The seat cushion S 1  includes a seat cushion frame including the pair of seat cushion side frames S 14  (side frames) provided to be separated from each other in a width direction of the vehicle seat S, the seat cushion pad S 11  placed on the seat cushion frame, and the impact absorbing member  220  provided below the seat cushion pad S 11 . The impact absorbing member  220  is disposed between the pair of seat cushion side frames S 14  (side frames) in the width direction of the vehicle seat S. The impact absorbing member  220  includes a recessed portion. The recessed portion is provided in a seating portion of an occupant. 
     According to such a configuration, the recessed portion of the impact absorbing member  220  is disposed between a center of the vehicle seat S (seating portion of the occupant) and the pair of side frames. Hence, an impact can be stably absorbed. 
     [2] In the conveyance seat described in [1], the recessed portion is the first recessed portion  221   b  provided to have an opening on an upper surface  221  side of the impact absorbing member  220 , and the first recessed portion  221   b  has a shape having rounded corners. 
     According to such a configuration, the first recessed portion  221   b  has a shape having rounded corners, and is provided in the upper surface  221  of the impact absorbing member  220 , so that impact absorbability is stable. 
     [3]In the conveyance seat described in [1] or [2], the recessed portion is the second recessed portion  222   b  provided to have an opening on a lower surface  222  side of the impact absorbing member  220 , and the second recessed portion  222   b  has a shape having rounded corners. 
     According to such a configuration, the second recessed portion  222   b  has a shape having rounded corners, and is provided in the lower surface  222  of the impact absorbing member  220 , so that impact absorbability is stable. 
     [4] In the conveyance seat described in [2], the first recessed portion  221   b  is provided with the first bottom surface  221   c  between the upper surface  221  and the lower surface  222  of the impact absorbing member  220 . 
     According to such a configuration, the rigidity of the first recessed portion  221   b  is improved, so that an impact absorption efficiency is improved. 
     [5] In the conveyance seat described in [3], the second recessed portion  222   b  is provided with the second bottom surface  222   c  between the upper surface  221  and the lower surface  222  of the impact absorbing member  220 . 
     According to such a configuration, the rigidity of the second recessed portion  222   b  is improved, so that an impact absorption efficiency is improved. 
     [6] In the conveyance seat described in any one of [1] to [5], the recessed portion includes the first recessed portion  221   b  provided to have an opening on an upper surface  221  side of the impact absorbing member  220 , and the second recessed portion  222   b  provided to have an opening on a lower surface  222  side of the impact absorbing member  220 . The first recessed portion  221   b  is provided with the first bottom surface  221   c.  The second recessed portion  222   b  is provided with the second bottom surface  222   c.  The first bottom surface  221   c  and the second bottom surface  222   c  are separated from each other in the up to down direction of the vehicle seat S, and the gap  223   c  (space portion) is formed between the first bottom surface  221   c  and the second bottom surface  222   c.    
     According to such a configuration, the gap  223   c  (space portion) functions as an elastic deformable region, so that the adjustment of impact absorption is facilitated. 
     [7] In the conveyance seat described in any one of [1] to [5], the recessed portion includes the first recessed portion  221   b  provided to have an opening on an upper surface  221  side of the impact absorbing member  220 , and the second recessed portion  222   b  provided to have an opening on a lower surface  222  side of the impact absorbing member  220 . The first recessed portion  221   b  is provided with the first bottom surface  221   c.  The second recessed portion  222   b  is provided with the second bottom surface  222   c.  The first bottom surface  221   c  and the second bottom surface  222   c  are in contact with each other in the up to down direction of the vehicle seat S. 
     According to such a configuration, the thickness of the bottom surface portion is increased and rigidity is improved by the first bottom surface  221   c  and the second bottom surface  222   c,  so that an impact absorption efficiency is improved. 
     [8] In the conveyance seat described in any one of [1] to [7], a plurality of the recessed portions are provided at a center of the impact absorbing member  220 . 
     According to such a configuration, the recessed portions are provided at the center of the impact absorbing member  220 , so that an impact can be stably absorbed. 
     [9] In the conveyance seat described in any one of [1] to [8], the recessed portion is provided between a center of the seating portion and a skin pull-in portion in the width direction of the vehicle seat S. 
     According to such a configuration, the recessed portion is provided between the center of the seating portion of the occupant and the skin pull-in portion, so that an impact can be stably absorbed. 
     [10] In the conveyance seat described in any one of [1] to [9], the recessed portion is provided at a position clear of an outer wall portion of the impact absorbing member  220 . 
     According to such a configuration, the shape of the recessed portion can be stably formed, so that an impact can be stably absorbed. 
     6. THIRD MODIFICATION EXAMPLE 
     The present invention is not limited to the above embodiments. Hereinafter, a third modification example of the impact absorbing member and the seat cushion according to the present embodiment will be described with reference to  FIGS. 17A to 18B . In the following description, differences from the above embodiments will be mainly described. 
     As illustrated in  FIGS. 17A to 18B , an impact absorbing member  320  is formed in a box shape including an internal space  320   a.  A plurality of rib members  320   b  having a plate shape are disposed side by side in the seat width direction in the internal space  320   a.  In other words, the plurality of rib members  320   b  having a plate shape and extending in the front to back direction and the up to down direction are disposed in the internal space  320   a.    
     In addition, the impact absorbing member  320  is configured to have an upper surface  321  and a lower surface  322  in the up to down direction, a front surface  323  and a rear surface  324  in the front to back direction, and a first side surface  325   a  and a second side surface  325   b  in the seat width direction. 
     The upper surface  321  of the impact absorbing member  320  is mainly formed of the rib members  320   b.  The upper surface  321  has an inclined surface  321   a  that is inclined downward as extending backward. 
     Then, a plate-shaped member  326  is disposed to cover the inclined surface  321   a.    
     The plate-shaped member  326  is insert-molded in the lower surface S 11   a  corresponding to the back surface of the seat cushion pad S 11  made of urethane at a position facing the inclined surface  321   a  of the impact absorbing member  320 . The plate-shaped member  326  is made of a resin material (polypropylene, high-hardness urethane, etc.) or a metal material (iron, steel, etc.). 
     Similarly to the impact absorbing member  20  in  FIG. 1B , the impact absorbing member  320  is disposed between the pair of seat cushion side frames S 14  in the seat width direction. Namely, each of the rib members  320   b  is provided in the seating portion of the occupant. 
     In the impact absorbing member  320 , the rib members  320   b  are disposed in the internal space  320   a  so as to be crushed to absorb an impact when a certain load value is exceeded during input of a load from the occupant. In the impact absorbing member  320 , an impact is to be absorbed mainly by the rib members  320   b.  An impact absorption load in the impact absorbing member  320  can be adjusted by changing the thickness of the rib members  320   b,  connecting the rib members  320   b  to each other in the seat width direction, providing a fragile portion in the rib members  320   b,  etc. 
     7. IMPACT ABSORBING DEVICE ACCORDING TO ANOTHER EMBODIMENT 
     A configuration of an impact absorbing device  50  according to another embodiment provided in the vehicle seat S ( FIGS. 1A and 1B ) of the present invention will be described with reference to  FIGS. 19 to 21 . 
       FIG. 19  is an exploded view illustrating a configuration of an impact absorbing portion  51 . The impact absorbing portion  51  is configured such that an energy absorbing plate  52  configured to be deformed to absorb an impact when a certain load value is exceeded is interposed between a pair of guide members  53 . Two grooves are formed in a side surface of the energy absorbing plate  52 , and the energy absorbing plate  52  is to be deformed easily when a load is applied thereto. In addition, a cutout  53   a  that accommodates a protrusion shaft  54   a  of an impact absorbing member  54  to be described later is formed in each of the guide members  53 . 
       FIG. 20  is a schematic view illustrating the configuration of the impact absorbing device  50 . The impact absorbing device  50  includes a pair of the impact absorbing portions  51  disposed to be separated from each other in the seat width direction, and the impact absorbing member  54  to which a load from the occupant is to be applied. The impact absorbing member  54  extends in the seat width direction, and includes the protrusion shafts  54   a  in both end portions thereof, the protrusion shafts  54   a  protruding outward. 
     The protrusion shaft  54   a  is accommodated in the cutouts  53   a  provided in the pair of guide members  53  of the impact absorbing portion  51 , and is placed on an upper surface of the energy absorbing plate  52  (energy absorbing member) from above. When a load from above is applied from a state illustrated in  FIG. 20 , the impact absorbing member  54  moves downward, and the protrusion shaft  54   a  deforms (breaks off) the energy absorbing plate  52 . At this time, an impact is to be absorbed with the deformation of the energy absorbing plate  52 . 
       FIG. 21  is a schematic view illustrating a state where the impact absorbing device  50  is applied to the vehicle seat S illustrated in  FIGS. 1A and 1B . As illustrated in  FIG. 21 , the impact absorbing device  50  is attached to an upper surface of a plate-shaped member  60  (support member) provided below the seat cushion pad S 11  of the seat cushion S 1 . As examples of the plate-shaped member  60 , although not particularly limited, a plate-shaped member forming the floor that supports the vehicle rear seat from below, a pan frame provided in a seat cushion frame, etc. are provided. Incidentally, the impact absorbing device  50  is disposed inward from a pair of seat cushion side frames (not illustrated) provided to be separated from each other in the seat width direction. 
     The impact absorbing member  54  includes a load-receiving surface  54   b  that receives a load from the occupant, and is configured to be rotatable downward around a rotation axis  55 . The impact absorbing portion  51  is a mechanism in which the protrusion shaft  54   a  slides downward, and easily adjusts a load value when an impact is absorbed. 
     The impact absorbing device  50  has a structure in which a load from the occupant is to be received by the load-receiving surface  54   b  (flat surface). The impact absorbing portions  51  are disposed at two locations in both end portions in the seat width direction to interpose the load-receiving surface  54   b  therebetween, and an impact is to be stably absorbed. 
     The rotation axis  55  of the impact absorbing member  54  is set as a rotation axis separate from a reclining rotation axis provided in the vehicle seat S. According to the impact absorbing device  50 , an impact can be effectively absorbed, so that space saving is realized. In addition, since the mechanism is such that the protrusion shaft  54   a  of the impact absorbing member  54  slides downward, operation stability during impact absorption is good. Further, since the impact absorbing device  50  is attached to the upper surface of the plate-shaped member  60  provided below the seat cushion pad S 11  of the seat cushion S 1 , assemblability or maintainability is good. 
     The vehicle seat S including the impact absorbing device  50  according to another embodiment is the vehicle seat S (conveyance seat) including the seat cushion S 1 . The seat cushion S 1  includes the seat cushion frame (seat cushion side frames S 14 ), the seat cushion pad S 11  placed on the seat cushion frame, and the impact absorbing device  50  provided below the seat cushion pad S 11 . The impact absorbing device  50  includes the impact absorbing member  54  extending in the width direction of the conveyance seat S, and the energy absorbing member (energy absorbing plate  52 ) that absorbs a load to be applied to the impact absorbing member  54  from above. The impact absorbing device  50  is supported from below by the support member (plate-shaped member  60 ). 
     The conveyance seat according to the present embodiment has been described above as an example of the vehicle seat. The seat cushion according to the present embodiment is not particularly limited in terms of application as long as the seat cushion is applicable to a seat in which an impact on a seated occupant can be generated, particularly, to a seat in which sinking of the waist of a seated occupant can occur when an impact is generated. For example, the seat cushion of the present invention can also be used as a seat cushion of a conveyance seat to be used in conveyances other than vehicles. 
     
       
         
           
               
             
               
                   
               
               
                 REFERENCE SIGNS LIST 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 S: 
                 vehicle seat (conveyance seat) 
               
               
                 S1: 
                 seat cushion 
               
               
                 S11: 
                 seat cushion pad 
               
               
                 S11a: 
                 lower surface 
               
               
                 S11b: 
                 pad recessed portion 
               
               
                 S12: 
                 trim cover 
               
               
                 T1: 
                 first pull-in portion (right pull-in portion) 
               
               
                 T2: 
                 second pull-in portion (left pull-in portion) 
               
               
                 T3: 
                 third pull-in portion (rear pull-in portion) 
               
               
                 S13: 
                 sensor member 
               
               
                 S13a: 
                 first sensor portion (right sensor portion) 
               
               
                 S13b: 
                 second sensor portion (left sensor portion) 
               
               
                 S13c: 
                 third sensor portion (rear sensor portion) 
               
               
                 S14: 
                 seat cushion side frame 
               
               
                   
                 (side frame, seat cushion frame) 
               
               
                 S2: 
                 seat back 
               
               
                 S3: 
                 headrest 
               
               
                  10: 
                 plate-shaped member (support member) 
               
               
                  11: 
                 recessed portion 
               
               
                  12: 
                 protrusion portion (sinking suppression member) 
               
               
                  13a: 
                 front bent portion (bent portion) 
               
               
                  13b: 
                 front bent portion (bent portion) 
               
               
                 20, 20X, 20A, 
                 impact absorbing member 
               
               
                 20B, 20C: 
               
               
                 21, 21X, 21A, 
                 upper surface 
               
               
                 21B, 21C: 
               
               
                  21a: 
                 inclined surface 
               
               
                 22, 22X, 22A, 
                 lower surface 
               
               
                 22B, 22C: 
               
               
                 23, 23X, 23A, 
                 cavity portion 
               
               
                 23B, 23C: 
               
               
                 S1X: 
                 seat cushion 
               
               
                 S11X: 
                 seat cushion pad 
               
               
                 S11Xa: 
                 lower surface 
               
               
                 S11Xb: 
                 pad recessed portion 
               
               
                 S12X: 
                 trim cover 
               
               
                 S14X: 
                 seat cushion frame (support member) 
               
               
                 S14Xa: 
                 recessed portion 
               
               
                 S14Xb: 
                 bottom surface 
               
               
                 S14Xc: 
                 seat cushion side frame 
               
               
                  10Y: 
                 support member 
               
               
                 WF: 
                 wire frame 
               
               
                 B: 
                 blower 
               
               
                 H: 
                 harness 
               
               
                 N: 
                 application region of abnormal noise inhibitor 
               
               
                 220: 
                 impact absorbing member 
               
               
                 221: 
                 upper surface 
               
               
                 221b: 
                 first recessed portion 
               
               
                 221c: 
                 first bottom surface 
               
               
                 222: 
                 lower surface 
               
               
                 222b: 
                 second recessed portion 
               
               
                 222c: 
                 second bottom surface 
               
               
                 223a: 
                 front space 
               
               
                 223b: 
                 rear space 
               
               
                 223c: 
                 gap (space portion) 
               
               
                 320: 
                 impact absorbing member 
               
               
                 320a: 
                 internal space 
               
               
                 320b: 
                 rib member 
               
               
                 321: 
                 upper surface 
               
               
                 321a: 
                 inclined surface 
               
               
                 322: 
                 lower surface 
               
               
                 323: 
                 front surface 
               
               
                 324: 
                 rear surface 
               
               
                 325a: 
                 first side surface 
               
               
                 325b: 
                 second side surface 
               
               
                 326: 
                 plate-shaped member 
               
               
                  50: 
                 impact absorbing device 
               
               
                  51: 
                 impact absorbing portion 
               
               
                  52: 
                 energy absorbing plate 
               
               
                  52a: 
                 groove 
               
               
                  53: 
                 guide member 
               
               
                  53a: 
                 cutout 
               
               
                  54: 
                 impact absorbing member 
               
               
                  54a: 
                 protrusion shaft 
               
               
                  54b: 
                 load-receiving surface 
               
               
                  55: 
                 rotation axis 
               
               
                  60: 
                 plate-shaped member