A damping force generating mechanism includes: a flow passage formation part that forms a flow passage through which a liquid flows; and a valve that is configured to control a flow of the liquid in the flow passage. The flow passage formation part includes a first seat part that is provided radially outward of a flow passage port of the flow passage, protrudes from the flow passage port and contacts the valve, a second seat part that is provided radially outward of the first seat part, protrudes from the flow passage port and contacts the valve, and a circulation part having an orifice that allows the liquid to flow from the flow passage port toward the second seat part in a state in which the valve is in contact with the first seat part.

A shock absorber including a pressure tube, a piston assembly slidably disposed within the pressure tube, and a fluid transfer tube that extends about the pressure tube is provided. The piston assembly divides an inner volume of the pressure tube into first and second working chambers. An intermediate chamber between the pressure tube and the fluid transfer tube is arranged in fluid communication with the first working chamber. A valve assembly is disposed in fluid communication with the intermediate chamber and the second working chamber. The valve assembly controls fluid flow between the intermediate chamber and the second working chamber. At least part of the intermediate chamber is formed by a fluid transfer channel that extends longitudinally within the fluid transfer tube to provide a fluid flow path extending between the first working chamber and the valve assembly.

An electronically controller external damper reservoir assembly (eRESI) can be connected to a passive damper and/or substituted for an existing external reservoir to provide semi-active damping control. The eRESI includes a reservoir and a variable base valve assembly actuated by an actuator. A controller is in communication with the actuator and a sensor providing input signal indicative of vehicle movement and is programmed to generate a damping control signal to the actuator based on the input signal, to dynamically control the damping force outputted by a passive damper hydraulically connected to the eRESI. A P/T sensor can be installed to a gas chamber of a vehicle damper to generate a P/T signal indicative of the pressure and temperature of the gas. The controller is programmed to determine a damper position of the damper based on the P/T signal.

An electronically controller external damper reservoir assembly (eRESI) can be connected to a passive damper and/or substituted for an existing external reservoir to provide semi-active damping control. The eRESI includes a reservoir and a variable base valve assembly actuated by an actuator. A controller is in communication with the actuator and a sensor providing input signal indicative of vehicle movement and is programmed to generate a damping control signal to the actuator based on the input signal, to dynamically control the damping force outputted by a passive damper hydraulically connected to the eRESI. A P/T sensor can be installed to a gas chamber of a vehicle damper to generate a P/T signal indicative of the pressure and temperature of the gas. The controller is programmed to determine a damper position of the damper based on the P/T signal.

A modular active valve system having a reduced footprint for use in a smaller shock platform is disclosed. The modular active valve system includes a multi-stage valve having a first stage and at least a second stage, wherein at least the first stage includes a semi-active valve for electronic damping control.

A vehicle height adjustment device includes a rear suspension, an electromagnetic valve control unit, and a weight estimation unit. The rear suspension includes a support member. The electromagnetic valve control unit determines a target movement based on an interrelation between the target movement and a weight applied to a vehicle, under which the target movement is set to an upper limit when the weight is larger than a predetermined weight, so that an actual movement of the support member reaches the target movement. The electromagnetic valve control unit determines the target movement based on a temporary weight. The weight estimation unit increases the temporary weight, even when the actual movement reached the target movement. The electromagnetic valve control unit decreases the target length, even when the temporary weight increased. The weight estimation unit estimates as the weight the temporary weight when the actual length has finally reached the target length.

A hydraulic damper includes: a cylinder containing liquid; a piston part configured to be connected to a rod moving in an axial direction and configured to move inside the cylinder; a channel forming part including a first channel in which the liquid flows along with movement of the piston part in one direction, and a second channel in which the liquid flows parallel to the first channel along with the movement of the piston part in the one direction; a valve part configured to control flow of the liquid in the first channel and the second channel; and a single advancing/retracting part configured to advance and retract the valve part to and from the first channel and the second channel.

A damping force generating mechanism includes: a flow passage formation part that forms a flow passage through which a liquid flows; a valve configured to control a flow of the liquid in the flow passage; a back pressure control valve configured to control a pressure in a back pressure chamber that provides a back pressure to the valve by inflow of the liquid; and an accommodation part that is in a tubular shape with one side opening end narrower than another side opening end, forms the back pressure chamber, and accommodates at least the valve and the back pressure control valve.

An actuator system for a vehicle suspension system includes: an actuator having a piston and a first fluid chamber separated from a second fluid chamber by the piston; a hydraulic pump having a first port connected by a first hydraulic circuit to the first chamber via a first valve, the first valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the first chamber; a first hydraulic accumulator connected to the first hydraulic circuit between the first port and the first valve; and a second hydraulic accumulator connected to the first port by a second valve, the second valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the first port to the second hydraulic accumulator.

A shock absorber includes: a pressure tube defining a working chamber; a piston assembly slidably disposed within the pressure tube, the piston assembly dividing the working chamber into a first and second chambers; a piston rod including a first end that is attached to the piston assembly and that includes a second end that is configured to be attached to one of a sprung mass and an unsprung mass of a vehicle; an electronic valve that is positioned within the piston rod, the electronic valve including a spool moveable between first and second positions, where: when the spool of the electronic valve is in the first position, the spool allows fluid flow between the first and second chambers through the electronic valve and the piston rod; and when the spool of the electronic valve is in the second position, the spool restricts fluid flow between the first and second chambers.