Abstract: A pin portion in which an introduction orifice leading to a back-pressure chamber is formed is disposed along inner peripheries of a main body, a main valve, and a pilot casing. A nut disposed on the pin portion is rotated relative to the pin portion to fasten the main body, the main valve, and the pilot casing together. This eliminates the necessity of machining a tool engagement portion in the pin portion and represses an increase in man-hours.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In a shock absorber, an extension-side check valve permitting a flow of hydraulic fluid directed from a common passage to a compression-side passage side, and a compression-side orifice establishing communication between the compression-side passage and a compression-side back-pressure chamber are provided in an extension-side discharge passage. A compression-side check valve permitting a flow of hydraulic fluid directed from the common passage to an extension-side passage side, and an extension-side orifice establishing communication between the extension-side passage and an extension-side back-pressure chamber are provided in a compression-side discharge passage. A pilot valve includes a valve body slidably inserted in the common passage, and a valve spring biasing the valve body in a valve-opening direction.

Abstract: 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.

Abstract: In a shock absorber, an extension-side check valve permitting a flow of hydraulic fluid directed from a common passage to a compression-side passage side, and a compression-side orifice establishing communication between the compression-side passage and a compression-side back-pressure chamber are provided in an extension-side discharge passage. A compression-side check valve permitting a flow of hydraulic fluid directed from the common passage to an extension-side passage side, and an extension-side orifice establishing communication between the extension-side passage and an extension-side back-pressure chamber are provided in a compression-side discharge passage. A pilot valve includes a valve body slidably inserted in the common passage, and a valve spring biasing the valve body in a valve-opening direction.

Abstract: Electro-rheological fluid serving as working fluid (2) is filled in a shock absorber (1). The shock absorber (1) is configured to control a generated damping force by generating an electric potential difference in an electrode passage (19) and controlling viscosity of the electro-rheological fluid which passes through the electrode passage (19). An adjusting valve (21) configured to generate a damping force is provided on a downstream side of the electrode passage (19). An orifice area, a spring stiffness, a port area, and the like of the adjusting valve (21) can be adjusted (changed) in accordance with a type, specifications, and the like of a vehicle in which the shock absorber (1) is installed. As a result, the damping force characteristic can be tuned as desired by a method other than adjustment of the damping force through voltage adjustment when the working fluid (2) passes through the electrode passage (19).