Abstract: A damping force control device 10 comprises vary damping shock absorbers, a detector, and a controller. Each of the shock absorbers sets damping coefficient from a minimum value to a maximum value in order to adjust damping force. The detector detects vertical vibration state quantity relating to vibration of the sprung mass. The controller performs an ordinary control for setting the damping coefficient based on the vertical vibration state quantity and according to a predetermined control law suitable for an assumption that all of the wheels touch ground. The controller performs, when at least one of the wheels is an ungrounded wheel which does not touch the ground and each of the other wheels is a grounded wheel which touches the ground, a specific control for setting the damping coefficient of the shock absorber corresponding to the grounded wheel to a first specific value greater than the minimum value.

Abstract: A damping force control device 10 comprises vary damping shock absorbers, a detector, and a controller. Each of the shock absorbers sets damping coefficient from a minimum value to a maximum value in order to adjust damping force. The detector detects vertical vibration state quantity relating to vibration of the sprung mass. The controller performs an ordinary control for setting the damping coefficient based on the vertical vibration state quantity and according to a predetermined control law suitable for an assumption that all of the wheels touch ground. The controller performs, when at least one of the wheels is an ungrounded wheel which does not touch the ground and each of the other wheels is a grounded wheel which touches the ground, a specific control for setting the damping coefficient of the shock absorber corresponding to the grounded wheel to a first specific value greater than the minimum value.

Abstract: A valve control device is configured to execute a specific valve control when a valve switching condition at high pressure is satisfied. The specific valve control switches the spring constant change valves for front wheel to a blocking state and switches a spring constant change valves for rear wheel to a communication permission state. The valve switching condition at high pressure is satisfied when oil pressure of hydraulic oil of rear wheel side oil hydraulic cylinders, which is detected by rear wheel side oil pressure detection means, is more than or equal to a predetermined oil pressure threshold and the traveling state determination means determines that a vehicle is in a predetermined traveling state.

Abstract: To improve off-road travel performance, ECU is configured to: set one of front left and right wheels and rear left and right wheels as roll stiffness decrease subject wheels and set another as non-roll stiffness decrease subject wheels; bring a spring switching valve and a leveling valve into an open state for each of the roll stiffness decrease subject wheels, causing left and right hydraulic cylinders to communicate to each other for the roll stiffness decrease subject wheels; and bring the spring switching valve and the leveling valve into a closed state and bring a bypass valve into the open state for one of the left and right wheels of the non-roll stiffness decrease subject wheels, to cause a second gas spring for one of the left and right wheels of the non-roll stiffness decrease subject wheels to communicate to the hydraulic cylinders of the roll stiffness decrease subject wheels.

Abstract: An air source device includes: a tank; a compressor; an intake valve; and an ECU configured to acquire an intake amount, which is an amount of air sucked from an outside and supplied to the tank by the compressor, based on an increasing amount of a tank pressure, which is a pressure of the air accommodated in the tank, the increasing amount being an increasing amount from a time point when the intake valve is estimated to be changed from a closed state to an opened state.

Abstract: A suspension system includes: suspensions that respectively include vehicle height control actuators; a pressure medium supply-discharge device; and a vehicle height controller configured to control the pressure medium supply-discharge device to control vehicle height, wherein a magnitude of resistance that is generated during a change in the vehicle height at one or more of the suspensions is larger than a magnitude of resistance at another one or more of the suspensions, and the vehicle height controller is configured to execute vehicle height control for the wheel that corresponds to the one or more of the suspensions with the large magnitude of the resistance prior to vehicle height control for the wheel that corresponds to the other one or more of the suspensions with the small magnitude of the resistance.

Abstract: A valve control device is configured to execute a specific valve control when a valve switching condition at high pressure is satisfied. The specific valve control switches the spring constant change valves for front wheel to a blocking state and switches a spring constant change valves for rear wheel to a communication permission state. The valve switching condition at high pressure is satisfied when oil pressure of hydraulic oil of rear wheel side oil hydraulic cylinders, which is detected by rear wheel side oil pressure detection means, is more than or equal to a predetermined oil pressure threshold and the traveling state determination means determines that a vehicle is in a predetermined traveling state.

Abstract: A vehicle-height adjusting system includes: vehicle-height adjusting actuators each for adjusting a vehicle height for a corresponding one of wheels; a pressure medium supplier for supplying a pressure medium from a tank to each of the vehicle-height adjusting actuators; and a vehicle height adjuster for adjusting the vehicle height for each wheel. The vehicle-height adjusting actuators include a left vehicle-height adjusting actuator and a right vehicle-height adjusting actuator. The vehicle height adjuster includes a supply amount controller configured to control the pressure medium supplier such that substantially the same amount of the pressure medium is to be supplied from the tank to the left vehicle-height adjusting actuator and the right vehicle-height adjusting actuator, when at least one of the wheels is in contact with an uneven road surface.

Abstract: To improve off-road travel performance, ECU is configured to: set one of front left and right wheels and rear left and right wheels as roll stiffness decrease subject wheels and set another as non-roll stiffness decrease subject wheels; bring a spring switching valve and a leveling valve into an open state for each of the roll stiffness decrease subject wheels, causing left and right hydraulic cylinders to communicate to each other for the roll stiffness decrease subject wheels; and bring the spring switching valve and the leveling valve into a closed state and bring a bypass valve into the open state for one of the left and right wheels of the non-roll stiffness decrease subject wheels, to cause a second gas spring for one of the left and right wheels of the non-roll stiffness decrease subject wheels to communicate to the hydraulic cylinders of the roll stiffness decrease subject wheels.

Abstract: A vehicle-height adjusting system includes: vehicle-height adjusting actuators each for adjusting a vehicle height for a corresponding one of wheels; a pressure medium supplier for supplying a pressure medium from a tank to each of the vehicle-height adjusting actuators; and a vehicle height adjuster for adjusting the vehicle height for each wheel. The vehicle-height adjusting actuators include a left vehicle-height adjusting actuator and a right vehicle-height adjusting actuator. The vehicle height adjuster includes a supply amount controller configured to control the pressure medium supplier such that substantially the same amount of the pressure medium is to be supplied from the tank to the left vehicle-height adjusting actuator and the right vehicle-height adjusting actuator, when at least one of the wheels is in contact with an uneven road surface.

Abstract: An air source device includes: a tank; a compressor; an intake valve; and an ECU configured to acquire an intake amount, which is an amount of air sucked from an outside and supplied to the tank by the compressor, based on an increasing amount of a tank pressure, which is a pressure of the air accommodated in the tank, the increasing amount being an increasing amount from a time point when the intake valve is estimated to be changed from a closed state to an opened state.

Abstract: A suspension system includes: suspensions that respectively include vehicle height control actuators; a pressure medium supply-discharge device; and a vehicle height controller configured to control the pressure medium supply-discharge device to control vehicle height, wherein a magnitude of resistance that is generated during a change in the vehicle height at one or more of the suspensions is larger than a magnitude of resistance at another one or more of the suspensions, and the vehicle height controller is configured to execute vehicle height control for the wheel that corresponds to the one or more of the suspensions with the large magnitude of the resistance prior to vehicle height control for the wheel that corresponds to the other one or more of the suspensions with the small magnitude of the resistance.