US 12,269,382 B2
Seat suspension mechanism
Etsunori Fujita, Hiroshima (JP); Soichi Makita, Hiroshima (JP); Shinichiro Maeda, Hiroshima (JP); Shogo Masumura, Hiroshima (JP); and Masaru Oka, Hiroshima (JP)
Assigned to DELTA KOGYO CO., LTD., Aki-Gun (JP)
Appl. No. 17/770,790
Filed by DELTA KOGYO CO., LTD., Hiroshima (JP)
PCT Filed Oct. 22, 2020, PCT No. PCT/JP2020/039739
§ 371(c)(1), (2) Date Apr. 21, 2022,
PCT Pub. No. WO2021/079943, PCT Pub. Date Apr. 29, 2021.
Claims priority of application No. 2019-192370 (JP), filed on Oct. 22, 2019.
Prior Publication US 2022/0371487 A1, Nov. 24, 2022
Int. Cl. B60N 2/54 (2006.01); B60N 2/68 (2006.01); B60N 2/90 (2018.01); F16F 1/06 (2006.01); F16F 6/00 (2006.01); F16F 15/03 (2006.01)
CPC B60N 2/54 (2013.01) [B60N 2/682 (2013.01); B60N 2/90 (2018.02); F16F 1/06 (2013.01); F16F 6/00 (2013.01); F16F 15/03 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A seat suspension mechanism comprising: an upper frame and a lower frame that are supported so as to be capable of a separating and approaching operation relative to each other, with a link mechanism therebetween; and a spring mechanism which elastically biases the upper frame,
wherein the spring mechanism includes:
a first spring part which biases the upper frame in a direction in which the upper frame separates from the lower frame; and
a second spring part which, when the upper frame is in a predetermined up-down movement range including a balanced point, exhibits a spring characteristic of biasing the upper frame in a direction in which the upper frame approaches the lower frame, to create a constant load spring characteristic by being combined with the first spring part,
the seat suspension mechanism further comprising a body weight adjustment mechanism which adjusts a position of the upper frame to the balanced point in a state in which a person is supported,
wherein the first spring part includes a lower frame-side torsion bar which is connected to the lower frame and is twisted by movement of the link mechanism and an upper frame-side torsion bar which is connected to the upper frame and is twisted by the movement of the link mechanism,
wherein the body weight adjustment mechanism includes:
an elastic force adjusting unit which is connected to the upper frame-side torsion bar and adjusts the position of the upper frame by twisting the upper frame-side torsion bar;
a torsion angle detection sensor which detects a torsion angle of the lower frame-side torsion bar; and
a control unit which compares the torsion angle of the lower frame-side torsion bar detected by the torsion angle detection sensor with a balanced point torsion angle that the lower frame-side torsion bar has when the upper frame is at the balanced point, and outputs, to the elastic force adjusting unit, a control signal instructing to twist the upper frame-side torsion bar by a predetermined amount to make the torsion angle of the lower frame-side torsion bar agree with the balanced point torsion angle, and
wherein a damper is suspended between the lower frame and the upper frame, and a movement zone of a piston in a cylinder of the damper corresponding to the predetermined up-down movement range including the balanced point when the upper frame moves up and down relative to the lower frame is free running zone where a damping force in the free running zone is lower compared with a damping force in a zone other than the free running zone.