US 9,068,618 B2Granted

Piston assembly of shock absorber

AssigneeMando Corporation

InventorChun Sung Yu

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Abstract

A piston assembly of a shock absorber is provided. A compression retainer and a rebound retainer are disposed above and under a piston body. A blow-off reducing unit is disposed between the compression retainer and an auxiliary valve and on a bottom surface of the auxiliary valve to form a plurality of blow-off points, so that a rapid variation in a damping force can be considerably reduced even in a low-speed and middle-speed transition period.

Claims8

Dependent claims

A piston assembly of a shock absorber, comprising:

a piston body in which a piston rod reciprocating within a cylinder penetrates a central portion thereof, and a compression passage and a rebound passage alternately penetrating the piston body are formed around the piston rod;
a compression retainer disposed above the piston body and penetrated by a first coupling hole corresponding to the compression passage;
a rebound retainer disposed under the piston body and penetrated by a second coupling hole corresponding to the rebound passage;
an auxiliary valve disposed under the rebound retainer and having a third coupling hole connected from the rebound passage through an outer periphery of the piston rod;
and
a blow-off reducing unit provided between the rebound retainer and the auxiliary valve and under the auxiliary valve, and configured to form a plurality of blow-off points by opening and closing a main passage, which is formed by mutual communication between the rebound passage and the second coupling hole during rebound and compression strokes, and a bypass passage, which is separated from the main passage and is formed by mutual communication with the third coupling hole connected from the rebound passage through the outer periphery of the piston rod,
wherein the piston rod comprises:
a first stepped portion which is formed to have an outer diameter smaller than a diameter of the piston rod and in which the compression retainer, the piston body, and the rebound retainer are sequentially disposed toward an end portion of the piston rod;
a second stepped portion which is formed to have an outer diameter smaller than a diameter of the first stepped portion and extends from the first stepped portion and in which the auxiliary valve is disposed;
and
a communication groove which is formed by recessing an outer periphery of the first stepped portion toward the second stepped portion, such that the rebound passage and the third coupling hole communicate with each other to form the bypass passage.

8 more elements

Dependencies are inferred from the claim text.

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Abstract

A piston assembly of a shock absorber, comprising:

a piston body in which a piston rod reciprocating within a cylinder penetrates a central portion thereof, and a compression passage and a rebound passage alternately penetrating the piston body are formed around the piston rod;
a compression retainer disposed above the piston body and penetrated by a first coupling hole corresponding to the compression passage;
a rebound retainer disposed under the piston body and penetrated by a second coupling hole corresponding to the rebound passage;
an auxiliary valve disposed under the rebound retainer and having a third coupling hole connected from the rebound passage through an outer periphery of the piston rod;
and
a blow-off reducing unit provided between the rebound retainer and the auxiliary valve and under the auxiliary valve, and configured to form a plurality of blow-off points by opening and closing a main passage, which is formed by mutual communication between the rebound passage and the second coupling hole during rebound and compression strokes, and a bypass passage, which is separated from the main passage and is formed by mutual communication with the third coupling hole connected from the rebound passage through the outer periphery of the piston rod,
wherein the piston rod comprises:
a first stepped portion which is formed to have an outer diameter smaller than a diameter of the piston rod and in which the compression retainer, the piston body, and the rebound retainer are sequentially disposed toward an end portion of the piston rod;
a second stepped portion which is formed to have an outer diameter smaller than a diameter of the first stepped portion and extends from the first stepped portion and in which the auxiliary valve is disposed;
and
a communication groove which is formed by recessing an outer periphery of the first stepped portion toward the second stepped portion, such that the rebound passage and the third coupling hole communicate with each other to form the bypass passage.

8 more elements