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 damper of shock and vibration. In one embodiment there is a hydraulic damper with a regressive damping characteristic in both compression and extension, such that damping forces decrease with increased stroking velocity within a predetermined range of stroking velocity. Outside of this range, damping forces are progressive, such that the damping force increases with increased stroking velocity. In another embodiment, there is a hydraulic damper with a second, slidable piston within one of the internal chambers defined by the main piston. This secondary piston is spring loaded and hydraulically latchable at either a first position or a second position based on the pressure differential across the main piston.

A damping valve device having a support with a circumferential groove in which a radially expandable annular element together with a flow surface forms a restriction, which restriction transitions from an open position to a restriction position depending on the flow velocity of a damping medium, and the maximum expansion position of the annular element is determined/limited by a stop. The annular element moves in direction of the open position with a delay when the flow velocity decreases by means of a dead time element.

A damping valve device having a support with a circumferential groove in which a radially expandable annular element together with a flow surface forms a restriction, which restriction transitions from an open position to a restriction position depending on the flow velocity of a damping medium, and the maximum expansion position of the annular element is determined/limited by a stop. The annular element moves in direction of the open position with a delay when the flow velocity decreases by means of a dead time element.

A damper of shock and vibration. In one embodiment there is a hydraulic damper with a regressive damping characteristic in both compression and extension, such that damping forces decrease with increased stroking velocity within a predetermined range of stroking velocity. Outside of this range, damping forces are progressive, such that the damping force increases with increased stroking velocity. In another embodiment, there is a hydraulic damper with a second, slidable piston within one of the internal chambers defined by the main piston. This secondary piston is spring loaded and hydraulically latchable at either a first position or a second position based on the pressure differential across the main piston.

An active engine mounting device is provided. The active engine mounting device includes upper and lower liquid chambers partitioned by a valve unit and adjusts a vibration and a load input from an engine in response to a driving condition while a fluid passes through the valve unit and attenuates the vibration and the load. The active engine mounting device includes an insulator that encloses a core integrally formed with a mounting bolt and elastically deformed based on the load applied to the core. A main case is disposed at a circumference of a lower end portion of the insulator. A diaphragm is disposed under the main case. The valve unit is configured to selectively pass the fluid through three channels based on operation of the valve. An actuator is disposed through an auxiliary case to drive the valve in an axial direction.

An active engine mounting device is provided. The active engine mounting device includes upper and lower liquid chambers partitioned by a valve unit and adjusts a vibration and a load input from an engine in response to a driving condition while a fluid passes through the valve unit and attenuates the vibration and the load. The active engine mounting device includes an insulator that encloses a core integrally formed with a mounting bolt and elastically deformed based on the load applied to the core. A main case is disposed at a circumference of a lower end portion of the insulator. A diaphragm is disposed under the main case. The valve unit is configured to selectively pass the fluid through three channels based on operation of the valve. An actuator is disposed through an auxiliary case to drive the valve in an axial direction.

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.