Load detection structure for vehicle seat

A load detection structure provided under a bottom side of a seat cushion of a vehicle seat and in at least one support leg member, wherein said at least one support leg member has a pair of mutually opposed vertical walls, a bottom wall defined between said pair of mutually opposed vertical walls, and at least one downwardly-extending securing leg portion integrally formed in at least one end thereof, said support leg member being adapted to be firmly secured to a floor, wherein said load detection structure includes a load detection means for detecting a load applied from an occupant on the vehicle seat, and wherein said load detection means comprises:

• at least one block member having an elongated body extending in the longitudinal direction thereof, said at least one block member having a rigid yet elastically deformable property and including, defined therein, a securing portion, a pivotal end portion, and a thin intermediate portion between said securing portion and said pivotal end portion;
• a strain gauge element fixedly attached to said thin intermediate portion of said at least one block member;
• at least two first holes formed in said bottom wall of said at least one support leg member in vicinity of said at least one downwardly-extending securing leg portion;
• at least two second holes formed respectively in said pair of mutually opposed vertical walls of said support leg member;
• at least two pins provided in said securing portion of the at least one block member, said at least two pins each including a small-diameter portion and a large-diameter portion, wherein said large-diameter portion extends downwardly through one of said at least two first holes, with a small clearance given peripherally thereof to space the large-diameter portion from said each of the at least two first holes, said large-diameter portion having a flat head large in diameter than said each of the at least two first holes;
• at least one pair of flanged collars;
• and
• said block member being interposed between said bottom side of the seat cushion and said at least one support leg member in such a manner that said securing portion of the at least one block member is securely connected, by said small-diameter portions of said at least two pins, with said bottom side of the seat cushion, with said large-diameter portions of said at least two pins extending through said at least first holes, respectively, while said pivotal end portion of the at least one block member is rotatably journalled by a pivot pin between said pair of mutually opposed vertical walls of said at least one support leg member by fitting said at least one pair of flanged collars in the respective said at least two second holes and then inserting said pivot pin through said at least one pair of flanged collars and said at least two second holes;
• wherein, when a downward load is applied to the seat in a vertical direction, said securing portion of the at least one block member is displaced in a generally rectilinear downward direction, while at the same time, said pivotal end portion of the at least one block member is rotated about said pivot pin, whereupon a difference is caused in movement and direction between said securing portion and said pivotal end portion, thereby causing deflection of said thin intermediate portion, and, in response thereto, said strain gauge element detects an amount of said deflection and emits a corresponding value indicative of an amount of said load.

A load detection structure provided under a bottom side of a seat cushion of a vehicle seat and in at least one support leg member, wherein the at least one support leg member has:

• a pair of mutually opposed vertical walls;
• a bottom wall defined between said pair of mutually opposed vertical walls;
• at least one end;
• and at least one downwardly-extending securing leg portion fixed to said bottom wall in vicinity of said at least one end, said support leg member being adapted to be firmly secured to a floor at the at least one downwardly-extending securing leg portion thereof, wherein said load detection structure includes a load detection means for detecting a load applied from an occupant on the vehicle seat, and wherein said load detection means comprises:
• at least one block member having an elongated body extending in the longitudinal direction thereof, said at least one block member having a rigid yet elastically deformable property and including, defined therein, a securing portion, a pivotal end portion and a thin intermediate portion between said securing portion and said pivotal end portion,
• a strain gauge element fixedly attached to said thin intermediate portion of said at least one block member;
• one first hole formed in said bottom wall of said support leg member at a point distant from said at least one downwardly-extending securing leg portion;
• at least two second holes formed respectively in said pair of mutually opposed vertical walls of said support leg member;
• at least two pins provided in said securing portion of the at least one block member, wherein one of said at least two pins comprises a small-diameter portion and a large-diameter portion, wherein said large-diameter portion extends through of said one first hole, with a small clearance given peripherally thereof to space the large-diameter portion from said one first hole, said large-diameter portion having a flat head large in diameter than said one first hole;
• at least one pair of flanged collars;
• and
• said block member being interposed between said bottom side of the seat cushion and said support leg member in such a manner that said securing portion of the at least one block member is securely connected, by said small-diameter portions of said at least two pins, with said bottom side of the seat cushion, with said large-diameter portions of said at least two pins extending through the respective said at least second wholes, while said pivotal end portion of the at least one block member is rotatably journalled by a pivot pin between said pair of mutually opposed vertical walls of said at least one support leg member by fitting said at least one pair of flanged collars in the respective said at least two second holes and then inserting said pivot pin through said at least one pair of flanged collars and said at least two second holes;
• wherein, when a downward load is applied to the seat in a vertical direction, said securing portion of the at least one block member is displaced in a generally rectilinear downward direction, while at the same time, said pivotal end portion of the at least one block member is rotated about said pivot pin, whereupon a difference is caused in movement and direction between said securing portion and said pivotal end portion, thereby causing deflection of said thin intermediate portion, and, in response thereto, said strain gauge element detects an amount of said deflection and emits a corresponding value indicative of an amount of said load.