HYDRAULIC POWER STEERING SYSTEM
First Claim
1. A hydraulic power steering system that includes:
- a hydraulic cylinder in which an interior is partitioned into a first hydraulic chamber and a second hydraulic chamber by a piston provided on a steered shaft; and
a variable displacement electric pump that supplies a hydraulic fluid to the hydraulic cylinder, and the hydraulic power steering system assisting a steering operation for steering a vehicle by moving the steered shaft together with the piston using a force produced due to a difference between a hydraulic pressure in the first hydraulic chamber and a hydraulic pressure in the second hydraulic chamber, the hydraulic power steering system comprising;
a selector valve that is selectively set in an operation mode in which the hydraulic fluid is supplied to the first hydraulic chamber while the hydraulic fluid is drained from the second hydraulic chamber or in an operation mode in which the hydraulic fluid is supplied to the second hydraulic chamber while the hydraulic fluid is drained from the first hydraulic chamber;
a detector that detects an operation state of the vehicle; and
a controller that sets, based on the operation state detected by the detector, a fluid supply-drain manner in which the hydraulic fluid is supplied to and drained from the hydraulic cylinder, and controls the operation mode of the selector valve and an amount of hydraulic fluid that is supplied from the electric pump based on the set fluid supply-drain manner.
1 Assignment
0 Petitions
Accused Products
Abstract
A hydraulic power steering system includes: a hydraulic cylinder in which an interior is partitioned into first and second hydraulic chambers by a piston on a steered shaft; a variable displacement electric pump that supplies hydraulic fluid to the hydraulic cylinder; a selector valve selectively set in a mode in which the hydraulic fluid is supplied to the first hydraulic chamber and drained from the second hydraulic chamber or in a mode in which the hydraulic fluid is supplied to the second hydraulic chamber and drained from the first hydraulic chamber; a detector that detects torque, steering angle, and/or vehicle speed; and a controller.
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Citations
18 Claims
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1. A hydraulic power steering system that includes:
- a hydraulic cylinder in which an interior is partitioned into a first hydraulic chamber and a second hydraulic chamber by a piston provided on a steered shaft; and
a variable displacement electric pump that supplies a hydraulic fluid to the hydraulic cylinder, and the hydraulic power steering system assisting a steering operation for steering a vehicle by moving the steered shaft together with the piston using a force produced due to a difference between a hydraulic pressure in the first hydraulic chamber and a hydraulic pressure in the second hydraulic chamber, the hydraulic power steering system comprising;a selector valve that is selectively set in an operation mode in which the hydraulic fluid is supplied to the first hydraulic chamber while the hydraulic fluid is drained from the second hydraulic chamber or in an operation mode in which the hydraulic fluid is supplied to the second hydraulic chamber while the hydraulic fluid is drained from the first hydraulic chamber; a detector that detects an operation state of the vehicle; and a controller that sets, based on the operation state detected by the detector, a fluid supply-drain manner in which the hydraulic fluid is supplied to and drained from the hydraulic cylinder, and controls the operation mode of the selector valve and an amount of hydraulic fluid that is supplied from the electric pump based on the set fluid supply-drain manner. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- a hydraulic cylinder in which an interior is partitioned into a first hydraulic chamber and a second hydraulic chamber by a piston provided on a steered shaft; and
Specification