A hydraulic vibration damper, in particular for a vehicle chassis, includes a cylinder tube for receiving a hydraulic fluid. A piston is axially movable within the cylinder tube along a cylinder tube axis and subdivides the cylinder tube into two working chambers. A piston rod is oriented parallel to the cylinder tube axis and is connected to the piston. At least one valve assembly for damping the piston movement in a direction of actuation is arranged at a fluid leadthrough. A bypass duct includes a sub-duct provided in addition to the fluid leadthrough between the two working chambers. A valve arrangement with continuously adjustable damping force is provided which regulates the throughflow through the fluid leadthrough and the sub-duct. The sub-duct includes a throttling mechanism, having a throttle, and a non-return valve. The throttle and the non-return valve of the sub-duct are arranged in series.

A hydraulic vibration damper, in particular for a vehicle chassis, includes a cylinder tube for receiving a hydraulic fluid. A piston is axially movable within the cylinder tube along a cylinder tube axis and subdivides the cylinder tube into two working chambers. A piston rod is oriented parallel to the cylinder tube axis and is connected to the piston. At least one valve assembly for damping the piston movement in a direction of actuation is arranged at a fluid leadthrough. A bypass duct includes a sub-duct provided in addition to the fluid leadthrough between the two working chambers. A valve arrangement with continuously adjustable damping force is provided which regulates the throughflow through the fluid leadthrough and the sub-duct. The sub-duct includes a throttling mechanism, having a throttle, and a non-return valve. The throttle and the non-return valve of the sub-duct are arranged in series.

[Problem] The present invention provides a damping force adjustable shock absorber capable of reducing manufacturing cost.

[Means for Solving] A shock absorber 1 is configured in such a manner that a main valve 32 is disposed below a piston valve 5, and a sub valve 68 for variably adjusting a set load of the main valve 32 is provided in a piston case 21 above the piston valve 5, with a first valve body 53 of the sub valve 68 slidably sealed to a case member 60 by a metal seal at only one portion. Due to the configuration, the shock absorber 1 can ease precision of components of the sub valve 68, thereby reducing the manufacturing cost.

[Problem] The present invention provides a damping force adjustable shock absorber capable of reducing manufacturing cost.

[Means for Solving] A shock absorber 1 is configured in such a manner that a main valve 32 is disposed below a piston valve 5, and a sub valve 68 for variably adjusting a set load of the main valve 32 is provided in a piston case 21 above the piston valve 5, with a first valve body 53 of the sub valve 68 slidably sealed to a case member 60 by a metal seal at only one portion. Due to the configuration, the shock absorber 1 can ease precision of components of the sub valve 68, thereby reducing the manufacturing cost.

A controller 10 as a generation mechanism control portion includes a base control portion 15 that determines a lower limit value on an instruction signal (i.e., a base instruction value) that serves as a lower limit on a force to be generated by a variable damper 6 (a force generation mechanism) according to at least a running speed of a vehicle. The base control portion 15 corrects the base instruction value by a base instruction value calculation portion 28 based on a result of a determination about a road surface output from a road surface determination portion 26 (i.e., a result of detection by a road surface state detection portion). A vehicle behavior control apparatus is configured to variably control a damping force characteristic of the variable damper 6 according to a road surface state with use of an instruction value output from the controller 10.

A controller 10 as a generation mechanism control portion includes a base control portion 15 that determines a lower limit value on an instruction signal (i.e., a base instruction value) that serves as a lower limit on a force to be generated by a variable damper 6 (a force generation mechanism) according to at least a running speed of a vehicle. The base control portion 15 corrects the base instruction value by a base instruction value calculation portion 28 based on a result of a determination about a road surface output from a road surface determination portion 26 (i.e., a result of detection by a road surface state detection portion). A vehicle behavior control apparatus is configured to variably control a damping force characteristic of the variable damper 6 according to a road surface state with use of an instruction value output from the controller 10.

Embodiments disclosed herein provide a vehicular active shock absorber in which two variable valves is able to be operated by one solenoid, a tube connecting a damping force-variable valve and the pump is not subjected to a bending force and is not expanded, and a space of a compression chamber is small. According to the embodiments, there is provided a vehicular shock absorber including: a damper including a cylinder, a piston valve disposed inside the cylinder, and a piston rod, of which one end is connected to the piston valve and a remaining end is connected to a vehicle body; a damping force-variable valve assembly attached to an outer portion of the damper and configured to regulate a flow of the working fluid of the damper; a pump fixed to the vehicle body; and a tube configured to make the pump and a piston road flow path provided in the piston rod communicate with each other. The piston rod flow path makes the tube and an extension chamber of the damper communicate with each other.

A hydrostatic drive system is disclosed which allows for simpler and more robust control of hydraulic vibration. The system comprises first and second hydraulic drive units and a variable damping device. At least the first hydraulic drive unit is a variable displacement type and comprises a displacement control. The variable damping device comprises at least one variable element. The system comprises a first linkage apparatus between the displacement control and the variable element and is operable to control the variable element in accordance with the displacement of the displacement control.

A hydrostatic drive system is disclosed which allows for simpler and more robust control of hydraulic vibration. The system comprises first and second hydraulic drive units and a variable damping device. At least the first hydraulic drive unit is a variable displacement type and comprises a displacement control. The variable damping device comprises at least one variable element. The system comprises a first linkage apparatus between the displacement control and the variable element and is operable to control the variable element in accordance with the displacement of the displacement control.

Some examples include a damper having an outer tube with a piston reciprocally mounted on an interior of the outer tube. A dampening force generating mechanism may be mounted on the outer tube within a threshold distance from a first end of the outer tube to control a dampening property of the piston. In addition, a vehicle interface adapter may seal the first end of the outer tube. The vehicle interface adapter may include an insertion portion extending outward from the first end of the outer tube. The insertion portion is able to be inserted into a cup-shaped portion of a vehicle attachment receptacle.