Damper valve and a hydraulic power steering device using the same
AssigneeKoyo Seiko Co., Ltd.
InventorOsamu Miyazaki
Life of this patent
Estimating the term…
Abstract
A casing accommodates therein a movable valve adapted to be moved away from a valve seat by a hydraulic oil flowing through an oil-hydraulic circuit from a hydraulic cylinder to an oil-hydraulic pump. In an event of oscillatory hydraulic pressures in the hydraulic cylinder, the hydraulic oil is returned through the oil-hydraulic circuit from the hydraulic cylinder to the oil-hydraulic pump via a second port, a communication path, a minor gap between the movable valve and the valve seat, and a first port. In this process, the communication path allows for a smooth flow of the hydraulic oil from the second port into the movable valve.
Claims4
A damper valve disposed on an oil-hydraulic circuit extended between an oil-hydraulic pump and a hydraulic actuator operated by a hydraulic oil supplied by the oil-hydraulic pump, the valve comprising:
- a hollow casing having a first port connected to the oil-hydraulic circuit at place on an oil-hydraulic-pump side, and a second port connected to the oil-hydraulic circuit at place on a hydraulic-actuator side;
- a cylindrical movable valve disposed in the casing as allowed to move along an oil passage therethrough;
- a valve sleeve disposed in the casing and having a valve seat allowing the movable valve to be seated on one end surface thereof;
- a spring for urging the movable valve thereby bringing one end surface of the movable valve into intimate contact with the valve seat of the valve sleeve;
- a check valve disposed in the valve sleeve and operative to permit the hydraulic oil delivered by the oil-hydraulic pump to flow from the first port through the movable valve and the valve sleeve to the second port but to restrict the reversed flow of the hydraulic oil;
- and
- a communication path formed in the valve sleeve and opening into the valve seat for the movable valve at one end thereof thereby allowing for a smooth flow of the hydraulic oil from the second port into the movable valve moved away from the valve seat.
Dependencies are inferred from the claim text.