Variable damping force damper

摘要

A first hydraulic fluid passage includes an annular fluid passage, an inlet hole and a notch of a magnetic passage forming ring, another notch and a communication hole of a non-magnetic passage forming ring, an outlet hole and a discharge hole of a valve plate, another discharge hole of a valve plate retainer, and a first fluid passage of a one-way valve retainer. On the other hand, a second hydraulic fluid passage includes a second fluid passage of the one-way valve retainer, and the annular fluid passage.

主权项

1. A variable damping-force damper comprising:
a cylinder including a hydraulic fluid sealed therein; a piston reciprocatably disposed in the cylinder and configured to partition the cylinder into a first fluid chamber and a second fluid chamber, the piston including a sliding contact portion configured to come into sliding contact with an inner circumferential surface of the cylinder; and a piston rod secured to the piston at one end thereof, the piston comprising: an inner yoke including a magnetic material, a magnetic coil disposed along an outer circumference of the inner yoke, an outer yoke including a magnetic material and surrounding the magnetic coil, a valve seat being formed integrally with the inner yoke or the outer yoke, a valve plate including a magnetic material, pressed to and brought into contact with the valve seat and configured to form an opening between the valve seat and the valve plate at a time of valve opening operation, valve holder configured to support the valve plate and having the sliding contact portion on an outer circumferential surface thereof, and an annular fluid passage formed between an outer circumferential surface of the outer yoke and the inner circumferential surface of the cylinder to communicate with the first fluid chamber, and partitioned from the second fluid chamber by the sliding contact portion, wherein the variable damping-force damper controls a damping force by supplying a current to the magnetic coil, the damping force being generated when the hydraulic fluid passes from the first fluid chamber to the second fluid chamber, wherein a first hydraulic fluid passage and a second hydraulic fluid passage are separately provided, the first hydraulic fluid passage extending from the first fluid chamber to the second fluid chamber through the annular fluid passage, an inlet hole formed at the outer circumference of the outer yoke, the opening formed between the valve seat and the valve plate, and a first fluid passage formed in the valve holder, and the second hydraulic fluid passage extending to the first fluid chamber through a second fluid passage formed in the valve holder and the annular fluid passage, the second hydraulic fluid passage being provided with a first one-way valve configured to pass a hydraulic fluid from the second fluid chamber to the annular fluid passage only.