Abstract: A body weight adjustment mechanism for automatic adjustment to a balanced point is provided to improve vibration absorption characteristics and impact absorption characteristics. A torsion angle of a lower frame-side torsion bar when an upper frame is at a balanced point is found in advance, a torsion angle of the lower frame-side torsion bar in a state in which a person is seated is detected, the detected torsion angle is compared with the aforesaid balanced point torsion angle, a control signal is sent to an elastic force adjusting unit, and torsion angles of upper frame-side torsion bars are adjusted so that the torsion angle of the lower frame-side torsion bar becomes equal to the balanced point torsion angle. The upper frame can be set to an appropriate position in an initial state and a static state in which a person is seated and vibration and impact absorption characteristics are improved.

Abstract: There are improved a vibration absorption characteristic and an impact absorption characteristic. A seat suspension mechanism set so that links of a first link mechanism on a base frame side and links of a second link mechanism on a seat support frame side, between which an intermediate frame is put, differ in operating angles, that is, so that the links of the second link mechanism operate in the range of an angle closer to a vertical to a front-rear direction of a vehicle body. This allows front-rear movement of the seat support frame through the second link mechanism to mainly respond to input vibrations of front-rear movement to thereby improve a vibration absorption characteristic and an impact absorption characteristic in the front-rear direction.

Abstract: A body weight adjustment mechanism for automatic adjustment to a balanced point is provided to improve vibration absorption characteristics and impact absorption characteristics. A torsion angle of a lower frame-side torsion bar when an upper frame is at a balanced point is found in advance, a torsion angle of the lower frame-side torsion bar in a state in which a person is seated is detected, the detected torsion angle is compared with the aforesaid balanced point torsion angle, a control signal is sent to an elastic force adjusting unit, and torsion angles of upper frame-side torsion bars are adjusted so that the torsion angle of the lower frame-side torsion bar becomes equal to the balanced point torsion angle. The upper frame can be set to an appropriate position in an initial state and a static state in which a person is seated and vibration and impact absorption characteristics are improved.

Abstract: There are improved a vibration absorption characteristic and an impact absorption characteristic. In a suspension mechanism 1 of the present invention, first and second dampers (150, 160) are suspended in parallel between an upper frame (120) and a lower frame (110) with mounting angles different from each other. For this reason, the smaller mounting angle the damper has, the smaller a vertical component of damping force becomes, and the damping force which acts on the upper frame (120) and the lower frame (110) which move up and down relatively is moderate in effectiveness as compared with a case of disposing all the dampers at the same mounting angle. Thus, a sense of incongruity in which strong damping force acts abruptly is suppressed and the vibration absorption characteristic and the impact absorption characteristic are improved, which leads to improvement in ride comfort.

Abstract: The operation in a closing direction and the operation in an opening direction of a storage rack are performed efficiently with small force. Fixed frames and a storage rack are connected by link mechanisms, and the link mechanism includes fixed-side links linked to the fixed frame and movable-side links linked to the storage rack. When a position of one ends of the movable-side links is located closer to one ends of the fixed-side links than a balanced point, the elastic member biases the storage rack in an open-position direction. In the open position, since the elastic member biases the storage rack in the opening direction, an open state is maintained as long as the position of the one ends of the movable-side links does not return to the change point position. Accordingly, the open position can be held by a simple structure without using electric power.

Abstract: To cause an appropriate damping force to work according to a relative displacement with a simple configuration. A movable inner cylinder 3 slidable in an outer cylinder 2 in an axial direction and having orifices 31 formed in its peripheral wall 31 is provided, a piston 5 around which a linear member 52 that generates a frictional force is wound is further provided in the movable inner cylinder 3, and a viscous liquid 7 is filled in the outer cylinder 2 including the inside of the movable inner cylinder 3. Accordingly, when the piston 5 moves together with the movable inner cylinder 3, a high damping force is not exerted, whereas when the piston 5 relatively moves in the movable inner cylinder 3, the high damping force is exerted owing to viscous friction between the piston 5 and the movable inner cylinder 3 and the viscous resistance of the viscous liquid passing through the orifices.

Abstract: There are improved a vibration absorption characteristic and an impact absorption characteristic. In a suspension mechanism 1 of the present invention, first and second dampers (150, 160) are suspended in parallel between an upper frame (120) and a lower frame (110) with mounting angles different from each other. For this reason, the smaller mounting angle the damper has, the smaller a vertical component of damping force becomes, and the damping force which acts on the upper frame (120) and the lower frame (110) which move up and down relatively is moderate in effectiveness as compared with a case of disposing all the dampers at the same mounting angle. Thus, a sense of incongruity in which strong damping force acts abruptly is suppressed and the vibration absorption characteristic and the impact absorption characteristic are improved, which leads to improvement in ride comfort.

Abstract: A vehicle seat includes a tension structure extended on a back frame with a configuration in which a natural frequency in the right-and-left direction of the back frame is set lower than the natural frequency in the front-and-rear direction. Thereby, the structure can easily deflect in the right-and-left direction. Therefore, since an impact load larger than a predetermined level inputted in the front-and-rear direction due to front-and-rear/pitching vibration or a rear collision and the like becomes a force of deflecting the back frame in the right-and-left direction, the vibration/impact energy is consumed by that, and moreover, rearward displacement of the back frame consumes vibration/impact energy. Thus, absorbing performances of the vibration/impact energy are higher than before.

Abstract: To achieve weight reduction while providing elasticity sufficient in a cushioning member for a vehicle seat, an elastic member made of expanded resin beads includes an elastic covering material having stretching properties stuck to an outer face of an expanded bead body. Therefore, when the elastic member made of expanded resin beads is bent or compressed, the respective beads themselves configuring the expanded bead body are elastically deformed according to stretching or compressing of the elastic covering material, and since the elastic deformation is not such deformation that a gap between beads of the expanded bead body largely expands, a crack occurring between beads or permanent deformation does not occur so that bending or compressing becomes possible. Accordingly, the elastic member made of expanded resin beads is suitable as a cushioning member utilizing an elastic recovering force in a bending direction and a thickness direction thereof.

Abstract: A structural material is provided, the strength and toughness of which are well-balanced at a high level, suitable in particular for seat frames in automobiles, aircrafts and the like. Specifically disclosed is a structural material produced by integrally joining thin steel members in a part thereof and, after joining, thermally heating a part thereof so that the heat-treated part differs from the other parts in strength and toughness. Unlike a structural material, the strength of which as a whole has been uniformly improved by heat treatment, the above-described structural material consists of a part having a high strength and a part having low strength. Thus, a structural material, the strength and toughness of which are well-balanced at a high level can be obtained. Since the strength and toughness are well-balanced at a high level, the structural material is suitable particularly for seat frames in automobiles, aircrafts and the like.

Abstract: To provide a technique suitable for elevating strength and toughness of a thin low-carbon steel. By performing rapid heating and rapid cooling to a thin low-carbon steel which is an ordinary steel with a thickness of 1.2 mm or less, a steel where a microstructure becomes a duplex grain size structure mixed with crystal grains having different grain diameters, which is not homogeneous, preferably, hard phase structures are contained in addition to the duplex grain size structure is obtained, and a high-strength and high-toughness thin low-carbon steel is obtained. Further, by performing a heat treatment process involving rapid heating and rapid cooling multiple times, a duplex grain size structure of crystal grains with smaller grain diameters or a hard phase structure contained therein is obtained, so that a thin low-carbon steel with higher strength and higher toughness is obtained.

Abstract: A seat has a configuration in which, in each side frame of a cushion frame, an inner frame and an outer frame which have flanges extending along peripheral edges thereof are faced to each other with a space therebetween at least partially, and the flanges are fixed by hemming process along the entire peripheral edges thereof. Since the entire peripheral edges are hemmed, the inner frame and the outer frame are securely fixed. Additionally, since the inner frame and the outer frame which are thin-plate-shaped are used, reduction in weight of each side frame can be achieved. Further, since the inner frame and the outer frame are faced to each other with a space therebetween at least partially, a compressive/tensile strength required as a side frame can be secured by inserting an expanded bead body into the space.

Abstract: A vehicle seat includes a tension structure extended on a back frame with a configuration in which a natural frequency in the right-and-left direction of the back frame is set lower than the natural frequency in the front-and-rear direction. Thereby, the structure can easily deflect in the right-and-left direction. Therefore, since an impact load larger than a predetermined level inputted in the front-and-rear direction due to front-and-rear/pitching vibration or a rear collision and the like becomes a force of deflecting the back frame in the right-and-left direction, the vibration/impact energy is consumed by that, and moreover, rearward displacement of the back frame consumes vibration/impact energy. Thus, absorbing performances of the vibration/impact energy are higher than before.

Abstract: To provide a technique suitable for elevating strength and toughness of a thin low-carbon steel. By performing rapid heating and rapid cooling to a thin low-carbon steel which is an ordinary steel with a thickness of 1.2 mm or less, a steel where a microstructure becomes a duplex grain size structure mixed with crystal grains having different grain diameters, which is not homogeneous, preferably, hard phase structures are contained in addition to the duplex grain size structure is obtained, and a high-strength and high-toughness thin low-carbon steel is obtained. Further, by performing a heat treatment process involving rapid heating and rapid cooling multiple times, a duplex grain size structure of crystal grains with smaller grain diameters or a hard phase structure contained therein is obtained, so that a thin low-carbon steel with higher strength and higher toughness is obtained.

Abstract: A structural material is provided, the strength and toughness of which are well-balanced at a high level, suitable in particular for seat frames in automobiles, aircrafts and the like. Specifically disclosed is a structural material produced by integrally joining thin steel members in a part thereof and, after joining, thermally heating a part thereof so that the heat-treated part differs from the other parts in strength and toughness. Unlike a structural material, the strength of which as a whole has been uniformly improved by heat treatment, the above-described structural material consists of a part having a high strength and a part having low strength. Thus, a structural material, the strength and toughness of which are well-balanced at a high level can be obtained. Since the strength and toughness are well-balanced at a high level, the structural material is suitable particularly for seat frames in automobiles, aircrafts and the like.

Abstract: A seat has a configuration in which, in each side frame of a cushion frame, an inner frame and an outer frame which have flanges extending along peripheral edges thereof are faced to each other with a space therebetween at least partially, and the flanges are fixed by hemming process along the entire peripheral edges thereof. Since the entire peripheral edges are hemmed, the inner frame and the outer frame are securely fixed. Additionally, since the inner frame and the outer frame which are thin-plate-shaped are used, reduction in weight of each side frame can be achieved. Further, since the inner frame and the outer frame are faced to each other with a space therebetween at least partially, a compressive/tensile strength required as a side frame can be secured by inserting an expanded bead body into the space.

Abstract: To achieve weight reduction while providing elasticity sufficient in a cushioning member for a vehicle seat, an elastic member made of expanded resin beads includes an elastic covering material having stretching properties stuck to an outer face of an expanded bead body. Therefore, when the elastic member made of expanded resin beads is bent or compressed, the respective beads themselves configuring the expanded bead body are elastically deformed according to stretching or compressing of the elastic covering material, and since the elastic deformation is not such deformation that a gap between beads of the expanded bead body largely expands, a crack occurring between beads or permanent deformation does not occur so that bending or compressing becomes possible. Accordingly, the elastic member made of expanded resin beads is suitable as a cushioning member utilizing an elastic recovering force in a bending direction and a thickness direction thereof.