| 摘要 |
<p>A normally closed line pressure regulator valve (48) has an orifice (72) that is opened and closed as the coil (74) of the solenoid is energized and deenergized. When the valve (48) is opened, the pump (16) outlet is opened to a vent port (82). A line pressure relief valve (54) in parallel with the solenoid valve (48) opens at a predetermined pressure when the solenoid valve (48) is closed and establishes a maximum line pressure. Minimum line pressure is determined by the pressure drops across orifices (38, 72) located between the outlet of the pump and the vent port (82). Line pressure is regulated between the maximum and minimum values by energizing and deenergizing the solenoid coil (74). </p> |
