A suspension system including four dampers is disclosed where each damper includes a compression chamber and a rebound chamber. A first hydraulic circuit includes a front hydraulic line, a rear hydraulic line, and a first longitudinal hydraulic line that extends between and fluidly connects the front and rear hydraulic lines of the first hydraulic circuit. A second hydraulic circuit includes a front hydraulic line, a rear hydraulic line, and a second longitudinal hydraulic line that extends between and fluidly connects the front and rear hydraulic lines of the second hydraulic circuit. First and second longitudinal comfort valves are positioned in the first and second longitudinal hydraulic lines, respectively, between the front and rear hydraulic lines. Both of the first and second longitudinal comfort valves are electromechanical valves and can be actuated to couple and decouple front axle roll control from rear axle roll control.

A suspension system including four dampers where each damper includes compression and rebound chambers. The suspension system has four hydraulic circuits, each including a cross-over hydraulic line that extends between dampers located at opposite corners of the vehicle (i.e., between the front left and back right dampers or between the front right and back left dampers). The suspension system further includes four electromechanical comfort valves that open and close four bridge hydraulic lines that extend between the cross-over hydraulic lines at each corner of the vehicle. Each cross-over hydraulic line is connected to a manifold assembly by a corresponding manifold hydraulic line. The manifold assembly includes four manifold valves that are connected to a pump assembly and two manifold comfort valves. All six comfort valves are electromechanical valves that can be actuated to control the roll and pitch of the vehicle during cornering, braking, and acceleration.

A road surface condition is determined appropriately. A road surface determining section (84) configured to determine a road surface state includes a threshold setting section (845) configured to set a threshold for determining the road surface state, so that a value of a desired control variable is multiplied by a coefficient determined in accordance with a result of the determination by the road surface determining section (84).

A ring circumscribing a moveable rod of a hydraulic damper, the moveable rod defining a central axis, the ring comprising a first circumferential surface, a second circumferential surface, a first finger, a second finger, a first flange, and a second flange. The first finger and the first flange defining a first end of the ring. The second finger and the second flange defining a second end of the ring.

A suspension system for a land vehicle is provided with at least one actuator connected to a chassis and an axle of a land vehicle spaced apart from a pivotal connection of the axle. A suspension circuit is in cooperation with the at least one actuator. A controller is in operable communication with the suspension circuit and is programmed to receive input indicative of a travel speed of the land vehicle. The suspension circuit is closed at a low speed travel range to permit the axle to pivot in response to variations in an underlying support surface. The suspension circuit is opened to permit selective actuation of the at least one actuator at a higher speed travel range in response to variations in the underlying support surface.

An active-passive dual mode switchable vehicle suspension system is provided. The suspension system includes a filter, a hydraulic pump, a one-way valve, a power takeoff, a servo valve, a suspension cylinder, an overflow valve, an energy accumulator, a reversing valve, a first pressure sensor, a second pressure sensor, a controller, an oil tank and a displacement sensor. Further related is a switching method for the active-passive dual mode switchable vehicle suspension system. When the active and passive dual-mode switchable vehicle suspension system is switched between modes, an oil pressure in the rodless cavity of the suspension cylinder and an oil pressure in the energy accumulator are adjusted to be equal in advance, so that the stable switching of the active-passive suspension system can be realized, and the vibration of the vehicle body is eliminated when the existing active-passive suspension system is switched. Moreover, the accumulator and overflow valve can be shared in the active and passive suspension mode, thereby effectively reducing the use number of accumulators and overflow valves, greatly saving the layout space of the vehicle body, effectively reducing the total weight of the vehicle body, which is favorable to the lightweight of the vehicle chassis.

A work vehicle includes a vehicle body, running gear to cause the vehicle body to travel, a height adjuster to change a height of a center of gravity of the vehicle body, and a controller configured or programmed to, in accordance with at least one of a turning radius and an angular velocity of the vehicle body during a turn, control the height adjuster to maintain or lower the height of the center of gravity.

The present disclosure relates to a shock absorber, in more detail, a damping force controlling shock absorber of which a damping force characteristic can be appropriately adjusted. A damping force controlling shock absorber according to the present disclosure includes: a cylinder formed in a double structure of an inside and an outside, having an internal space divided into a compression chamber and a rebound chamber by a piston valve, and having a reservoir chamber in an external space; a compression solenoid valve mounted on the cylinder; a rebound solenoid valve mounted on the cylinder; and a check valve disposed in the rebound solenoid valve, and opening and closing a channel connecting the reservoir chamber and the rebound chamber.

A method of operating an adjustable roll stabilizer for a motor vehicle. The stabilizer has an actuator which can be rotated through a system angle about a rotational axis to apply a system torque and rotate two stabilizer sections relative to one another about the axis. The stabilizer sections are coupled at a radial distance from the axis to a respective wheel suspension, and depending on the system angle and under the external influence of movements of the wheel suspensions, twist relative to one another through a stabilizer angle. In the context of a perturbation magnitude regulation, the actuator is controlled based on the stabilizer angle determined from height levels of the wheels, by virtue of a stored relationship for the roll stabilizer and/or motor vehicle. The plausibility of the stored relationship between the wheel height levels and the stabilizer angle is checked by a model calculation.

Methods, systems, devices and apparatuses for a torsion bar system. The torsion bar system includes a first torsion bar. The first torsion bar is configured to adjust a ride height of a first wheel of a vehicle. The torsion bar system includes a first actuator. The first actuator is coupled to the first torsion bar. The first actuator is configured to control a load on the first torsion bar. The torsion bar system includes an electronic control unit. The electronic control unit is coupled to the first actuator. The electronic control unit is configured to set a position of the first torsion bar using the first actuator and based on the load on the first torsion bar.