When a damping force adjustable shock absorber operates in a soft mode, a piston is performing a compression stroke, and a piston speed falls within an ultra low speed range, communication between an upper cylinder chamber and a reservoir is interrupted by an ultra low speed valve provided in a pilot passage. The interruption of communication enables expansion of an oil liquid in the upper cylinder chamber when the piston is performing the compression stroke and the piston speed falls within the ultra low speed range. A differential pressure is generated between an upper cylinder chamber side and a lower cylinder chamber side of a compression-side ultra low speed valve. As a result, when the piston speed falls within the ultra low speed range, the compression-side ultra low speed valve is opened, and a damping force having a valve characteristic achieved by the ultra low speed valve can be generated.

A damping force adjustable shock absorber including a compression-side ultra low speed valve that allows passage of an oil liquid from a lower cylinder chamber to an upper cylinder chamber. The compression-side ultra low speed valve is provided in a third passage and arranged in parallel to an extension-side ultra low speed valve. Thus, when a piston is performing a compression stroke and a piston speed falls within an ultra low speed range, oil liquid in the upper cylinder chamber can be expanded, resulting in a differential pressure between the upper cylinder chamber side and the lower cylinder chamber side of the compression-side ultra low speed valve (fifth low speed valve). As a result, when the piston speed falls within the ultra low speed range, the compression-side ultra low speed valve is opened, enabling generation of a damping force having a valve characteristic achieved by the ultra low speed valve.

A valve assembly includes a valve body defining an inner volume, a flow controller positioned within the inner volume, a plug positioned within the inner volume, and a biasing element. The plug is spaced from the flow controller such that an intermediate chamber is defined between the plug and the flow controller. The biasing element is positioned in the intermediate chamber between the plug and the flow controller. The plug is repositionable within the inner volume. As the plug moves within the inner volume, the plug interacts with the biasing element such that the biasing element provides a biasing force to the flow controller.

A shock absorber includes a cylinder in which oil is sealed, a piston slidably fitted into the cylinder, a piston rod connected to the piston and extending to the outside of the cylinder, and a damping force generating apparatus controlling a flow of the oil generated by the sliding of the piston inside the cylinder. The damping force generating apparatus includes a valve body generating a damping force by being opened and closed on a flow path in which the oil flows, a valve seat closing the flow path when the valve body is seated, and an actuator generating thrust to the valve body in a valve closing direction. The valve seat has a first elastic body which is elastically deformable in the valve closing direction of the valve body.

A controller of a shock absorber has a differential path configured to perform derivative compensation on the basis of a difference between a target pressure and a detected pressure or on the basis of the detected pressure, multiply the compensated value by a negative gain, and output a resulting value of the multiplication, and obtains an electric current instruction applied to a pressure control solenoid valve.

A valve arrangement comprising a main valve member being axially movably arranged in a valve housing and arranged to interact with a main valve seat of the valve housing in order to restrict or regulate a pressure in a main fluid flow in response to a pilot pressure acting on the main valve member. A control valve member is axially movable within the main valve member in response to an actuating force acting on the control valve member. A pilot valve member is axially movable within the control valve member, and is arranged to interact with a pilot valve seat of the control valve member to restrict a pilot fluid flow out from a pilot chamber. The pilot valve member is resiliently loaded towards the pilot valve seat relative the main valve member or the valve housing, such that the resilient loading on the pilot valve member is adjustable in response to the actuating force.

A shock absorber includes a cylinder-side member having an inner cylinder, a piston-side member having a piston and a piston rod that move relative to the inner cylinder, and a phase correction communication passage. The phase correction communication passage is provided between a bottom-side oil chamber, which is one side chamber, and a rod-side oil chamber, which is the other side chamber. That is, the phase correction communication passage is provided in the inner cylinder which is the cylinder-side member and communicates the bottom-side oil chamber and rod-side chamber with each other. By having a spiral conduit that advances in the axial direction while spiraling (orbiting) multiple times at the same diameter, the phase correction communication passage is configured as a second damping mechanism which generates a force (an axial force) that advances the phase of the damping force.

The present invention provides a shock absorber capable of improving responsiveness during an extension stroke without leading to an increase in an axial length. A shock absorber includes a chamber provided on a one-side end of a pilot valve and disposed in communication with a cylinder upper chamber, a communication passage configured to establish communication between the chamber and a cylinder lower chamber via a compression-side passage, and a check valve configured to permit hydraulic fluid in the communication passage to flow into the cylinder lower chamber during an extension stroke.

A hydraulic shock absorber includes: an expansion-side passage and a contraction-side passage that connect an expansion-side chamber with a contraction-side chamber; an expansion-side valve body configured to open or close the expansion-side passage; a contraction-side valve body configured to open or close the contraction-side passage; an expansion-side back-pressure chamber configured to bias the expansion-side valve body; a contraction-side back-pressure chamber configured to bias the contraction-side valve body; a communicating channel communicating with the expansion-side back-pressure chamber through an expansion-side resistance element, and with the contraction-side back-pressure chamber through a contraction-side resistance element; an expansion-side pressure introduction passage connecting the expansion-side chamber with the contraction-side back-pressure chamber; a contraction-side pressure introduction passage connecting the contraction-side chamber with the expansion-side back-pressure chamber; a regulating passage connected to the communicating channel; and a solenoid pressure control valve in the regulating passage to control a pressure in the upstream of the regulating passage.

A valve arrangement comprising a valve housing, a pilot chamber, a main valve member and a control valve member. The main valve member is axially movably arranged in the valve housing and is arranged to restrict a main fluid flow. The control valve member is movable in an axial direction relative the main valve member in response to an actuating force acting on the control valve member. The control valve member is arranged to interact with the main valve member to define axially separated pilot and bypass fluid restrictions. The pilot restriction restricts a pilot fluid flow out from the pilot chamber. The bypass restriction restricts a bypass flow bypassing the main fluid flow. The bypass flow is separate from the pilot fluid flow. The pilot and bypass restrictions are adjustable in response to the actuating force, thereby allowing simultaneous adjustment of the pilot pressure and the bypass fluid flow.