| 摘要 |
<p>With an electric water pump that circulates cooling water for an engine mounted in a vehicle or the like, the time interval for switching of the energization phase of the pump motor is set longer than during normal flow volume control (during flow volume control at a flow volume equal to or greater than the flow volume at which the electromotive force generated at the non-energization phase can be detected), and when the pump discharge pressure (or the temperature of the cooling water) repeatedly increases and decreases in this extremely low flow volume state, it is determined that the electric water pump is rotating correctly as required. By means of such a control it is possible to achieve an extremely low flow-volume control which is not possible with conventional control. Thus, with respect to controlling the stopping of the engine cooling system water, it is possible to provide an extremely low flow volume state, between a state in which the water is stopped and a state in which the water is circulating.</p> |
