| 摘要 |
A hydraulically assisted steering system comprises a fixed displacement hydraulic pump fluidly connected to a steering gear to deliver pressurized fluid to the steering gear. The flow of pressurized fluid includes pressure pulses produced by the pump. A bypass valve diverts a portion of the flow of pressurized fluid away from the steering gear before reaching the steering gear. Valve control apparatus electrically connected to the bypass controls operation of the bypass valve. The valve control apparatus includes a piezoelectric element to which the pressure pulses are applied. The piezoelectric element produces electrical signals in response to the applied pressure pulses. The valve control apparatus controls operation of the bypass valve in response to at least one parameter of the electrical signals. |
