A vehicle height adjustment device includes: a pressure tank capable of storing air in a compression state; a plurality of vehicle height adjustment units that are provided in correspondence with wheels of a vehicle and individually adjust vehicle heights at the respective wheels by supplying the air from the pressure tank or returning the air to the pressure tank; an information acquisition unit that acquires turn route information during travel of the vehicle; and a control unit that raises the vehicle height at the vehicle height adjustment unit on a turn outer side more than the vehicle height at the vehicle height adjustment unit on a turn inner side such that the vehicle takes a tilt posture on the basis of the turn route information when the vehicle turns.

An air-ride axle/suspension system for a heavy-duty vehicle. A frame and at least a pair of suspension assemblies support opposite ends of an axle for movement relative to the frame. An air spring is associated with one of the suspension assemblies that establishes a first relative position between the axle and the frame as a function of fluid pressure in the air spring. A tire and wheel assembly is operatively mounted to an end portion of the axle associated with the air spring. A sensor detects an inflation condition of the tire and wheel assembly. A venting system exhausts fluid pressure from the air spring to establish a second relative position between the axle and the frame that is different than the first relative position in response to detecting a predetermined inflation condition of the tire and wheel assembly.

The disclosure relates to a leveling system useful for self-leveling casters on suspension systems of harvesters, such as self-propelled windrowers. The suspension system utilizes position sensors and hydraulic actuators operably linked to each caster, the hydraulic actuators responding to a rotational position of the caster as detected by the respective position sensor to level the caster.

A pet mode door and suspension control system and method includes determining whether a door control action has occurred with respect to a door on the vehicle. When determined that the door control action has occurred, the system and method further includes determining whether a pet mode control action is needed. When determined that the pet mode control action is needed, a suspension control command is sent to suspension control system for raising and/or lowering at least one side of the vehicle and a door control command is sent to a power control unit for opening or closing the door in accord with the door control action.

A concurrent leveling system includes a pressurized air source. A manifold block, having a body defining an air feed inlet, is disposed between air springs and the pressurized air source. The body includes front and rear suspension valves. Each of the suspension valves defines a suspension valve orifice having a first predetermined diameter. The body includes at least one restrictor valve parallel to and in fluid communication with the front suspension valves. The at least one restrictor valve includes a first check valve and a first blocker valve orifice defining a first orifice diameter. The first check valve and the first blocker valve orifice are disposed parallel to one another and in series with the front suspension valves and in fluid communication with the air feed inlet and the front suspension valves for reducing fluid back flow to allow the vehicle to be lowered in nominal loading conditions.

An air suspension system capable of raising both the vehicle front wheel side and the vehicle rear wheel side by using a single tank. The air suspension system (1) includes a front wheel-side air suspension (2) and a rear wheel-side air suspension (7) which are interposed between a vehicle body and associated axles to perform vehicle height adjustment in response to supply and discharge of air, a compressor (17) for compressing air, and a tank (27) for storing air compressed by the compressor. When the vehicle height is to be raised by the air suspensions, the front wheel-side air suspension is supplied with compressed air from the tank, and the rear wheel-side air suspension is supplied with compressed air from the tank after the compressed air has been pressurized by the compressor.

Provided is a closed type air suspension apparatus requiring no complicated control and capable of simplifying the overall structure. The air suspension apparatus includes a tank storing air, a return valve returning compressed air in an air suspension to the tank, a discharge valve discharging compressed air in the tank to the outside through an intake-discharge port when the compressed air between the intake side of a compressor body and the tank reaches a first value or more, and an intake valve opening when the pressure of the air between the intake side of the compressor body and the tank is at a second value less than the first value, thereby allowing the atmosphere (air) to be taken in from the intake-discharge port. The compressor body of a compressor compresses air including the compressed air in the tank.

A levelling valve assembly for an air suspension system of a heavy vehicle is provided, including an air valve configured to allow air to either enter or escape from an air spring based on a position of a control arm of the air valve, and including a linkage rod assembly configured to translate movement between a sprung and unsprung mass of the vehicle into a rotation of the control arm to regulate a ride height of the vehicle. The linkage rod assembly further includes a spring and damper arrangement configured to dampen or block movement of the control arm not caused by a change in a mass loading of the vehicle.

A shock absorber with a vehicle height adjustment function according to the present invention includes a shock absorber main body that includes a cylinder filled with liquid, a piston that partitions inside of the cylinder into an extension side chamber and a compression side chamber, a piston rod coupled to the piston, a suspension spring that biases the shock absorber main body in an extending direction, a reservoir that accumulates liquid, a damper circuit that is connected to the extension side chamber, the compression side chamber, and the reservoir and generates a damping force in the shock absorber main body at the time when the shock absorber main body expands/contracts, a pump that is able to suck liquid from the reservoir and discharge the liquid, and a switching valve that is installed between the shock absorber main body and the damper circuit and the pump and switches a damper mode in which the shock absorber main body is connected to the damper circuit so as to generate a damping force in the shock absorber main body and a vehicle height adjustment mode in which the shock absorber main body is connected to the pump.

A compressed-air feed system for operating a pneumatic system includes a compressed-air supply, a compressed-air connection to the pneumatic system, a ventilation connection to surroundings, and a pneumatic main line between the compressed-air supply and the compressed-air connection. The pneumatic main line has an air dryer and a regeneration throttle. The compressed-air feed system further includes a ventilation line between the pneumatic main line and the ventilation connection. The ventilation line has a ventilation valve and a ventilation throttle. The compressed-air feed system further includes a bypass line between the compressed-air connection and the air dryer. The bypass line has a bypass valve formed as a 2/2 directional valve configured to permit an air flow conducted via the air dryer, and bypassing the regeneration throttle, for filling and ventilating the pneumatic system.