Damping force control type of hydraulic shock absorber
First Claim
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1. A damping force control hydraulic shock absorber comprising:
- a cylinder having a hydraulic fluid sealed therein;
a piston slidably fitted in said cylinder to define two chambers in said cylinder;
a piston rod having one end thereof connected to said piston and the other end thereof extending outside of said cylinder;
a main hydraulic fluid passage placing said two chambers in communication with each other;
a damping force generating mechanism, which dampens the flow of hydraulic fluid passing thereby, provided in said main hydraulic fluid passage;
a bypass passage placing said two chambers in communication with each other and bypassing said damping force generating mechanism;
a pair of first and second check valves provided in series in said bypass passage to allow hydraulic fluid to flow in respective directions which are different from each other through said bypass passage;
a guide member having a generally cylindrical side wall, opposite ends communicating with said bypass passage, and first and second bores extending through the side wall, said check valves covering said opposite ends of the guide member;
a first hydraulic fluid passage bypassing said first check valve, said first hydraulic fluid passage including said first bore and a space defined at the outer surface of said guide member and open to the first bore so as to be in communication with the interior of said guide member;
a second hydraulic fluid passage bypassing said second check valve, said second hydraulic fluid passage including said second bore and a space defined at the outer surface of said guide member and open to the second bore so as to be in communication with the interior of said guide member; and
a shutter disposed within said guide member over said first and said second bores and movable relative to said guide member, said shutter having a configuration that changes the degree to which said bores are open to the interior of said guide member when said shutter is moved relative to said guide member to thereby vary the sectional area of said first and said second hydraulic fluid passages at locations therein defined between said shutter and said guide member, respectively.
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Abstract
A damping force control type of hydraulic shock absorber includes a cylinder in which a piston is fitted to define two chambers. A main hydraulic fluid passage extends between the chambers, and a damping force generating mechanism is provided in the passage. A bypass passage is also provided between the two chambers. Two check valves are provided in the bypass passage and allow hydraulic fluid to flow in opposite directions, respectively, through the bypass passage. A first hydraulic fluid passage bypasses the first check valve and a second hydraulic fluid passage bypasses the second check valve. A control valve is provided to vary the sectional area of each of the first and second hydraulic fluid passages.
41 Citations
4 Claims
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1. A damping force control hydraulic shock absorber comprising:
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a cylinder having a hydraulic fluid sealed therein; a piston slidably fitted in said cylinder to define two chambers in said cylinder; a piston rod having one end thereof connected to said piston and the other end thereof extending outside of said cylinder; a main hydraulic fluid passage placing said two chambers in communication with each other; a damping force generating mechanism, which dampens the flow of hydraulic fluid passing thereby, provided in said main hydraulic fluid passage; a bypass passage placing said two chambers in communication with each other and bypassing said damping force generating mechanism; a pair of first and second check valves provided in series in said bypass passage to allow hydraulic fluid to flow in respective directions which are different from each other through said bypass passage; a guide member having a generally cylindrical side wall, opposite ends communicating with said bypass passage, and first and second bores extending through the side wall, said check valves covering said opposite ends of the guide member; a first hydraulic fluid passage bypassing said first check valve, said first hydraulic fluid passage including said first bore and a space defined at the outer surface of said guide member and open to the first bore so as to be in communication with the interior of said guide member; a second hydraulic fluid passage bypassing said second check valve, said second hydraulic fluid passage including said second bore and a space defined at the outer surface of said guide member and open to the second bore so as to be in communication with the interior of said guide member; and a shutter disposed within said guide member over said first and said second bores and movable relative to said guide member, said shutter having a configuration that changes the degree to which said bores are open to the interior of said guide member when said shutter is moved relative to said guide member to thereby vary the sectional area of said first and said second hydraulic fluid passages at locations therein defined between said shutter and said guide member, respectively. - View Dependent Claims (2, 3, 4)
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Specification
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Current AssigneeHitachi, Ltd.
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Original AssigneeTokico Limited (Hitachi, Ltd.)
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InventorsAshiba, Masahiro, Nakadate, Takao
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Primary Examiner(s)Butler, Douglas C.
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Application NumberUS07/986,036Time in Patent Office725 DaysField of Search188/319, 188/322.15, 188/322.22, 188/299, 188/281, 188/282, 188/322.13, 188/280, 188/317, 188/318, 188/316, 188/320, 188/288, 188/286, 188/285US Class Current188/282.1CPC Class CodesB60G 2500/102 stepwiseF16F 2230/36 Holes, slots or the likeF16F 9/468 controlling at least one by...
