초록 ▼

The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumpi

The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumping element has a delivery at least equal to the maximum draw of each injector, and is activated in phase with at least one of the injectors to minimize the variations in fuel pressure in the rail. Each pumping element may be activated by a cam, which may even have a segmented profile to effect a portion of the travel of the respective pumping element in phase with a corresponding injector.

대표청구항 ▼

The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumpi

The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumping element has a delivery at least equal to the maximum draw of each injector, and is activated in phase with at least one of the injectors to minimize the variations in fuel pressure in the rail. Each pumping element may be activated by a cam, which may even have a segmented profile to effect a portion of the travel of the respective pumping element in phase with a corresponding injector. the actuator; actuating the actuator only when the available vacuum is sufficient; and preventing actuation of the actuator when the available vacuum is insufficient; wherein determining the amount of vacuum available further comprises: determining a manifold pressure; and using the determined manifold pressure to determine a reservoir pressure. 10. The method of claim 9, wherein determining the amount of vacuum available further comprises: determining whether the actuator has been previously actuated; if the actuator has been previously actuated, determining an amount of vacuum lost from the vacuum reservoir during the previous actuation of the actuator; and determining a new reservoir pressure based on the amount of vacuum lost. 11. The method of claim 10, wherein determining whether the available vacuum is sufficient further comprises: determining an absolute pressure difference between the new reservoir pressure and an ambient pressure; and comparing the absolute pressure difference with a pre-determined threshold value. 12. The method of claim 9, wherein determining whether the available vacuum is sufficient further comprises: determining an absolute pressure difference between the reservoir pressure and an ambient pressure; and comparing the absolute pressure difference with a pre-determined threshold value. 13. The method of claim 9, wherein the actuator is a loaded actuator, and wherein determining the actuator is to be actuated further comprises: determining that the loaded actuator requires a vacuum input for a next actuation. 14. An actuator control system in a vehicle, the system comprising: a switching monitor operable to determine when the actuator is to be actuated; a vacuum level module operable to determine an amount of vacuum available to actuate the actuator; a switch operable to actuate the actuator; and a switch controller operable to determine whether the available vacuum is sufficient to actuate the actuator, and to actuate the switch only when the available vacuum is sufficient to actuate the actuator. 15. The system of claim 14, wherein the vehicle includes a vacuum reservoir for storing the available vacuum, and wherein the vacuum level module further comprises: a manifold pressure monitor operable to determine a manifold pressure; an ambient pressure monitor operable to determine an ambient pressure; and a reservoir pressure monitor operable to determine a vacuum reservoir pressure. 16. The system of claim 15, wherein the reservoir pressure monitor determines the vacuum reservoir pressure via mathematical modeling. 17. The system of claim 15, wherein the reservoir pressure monitor further comprises a reservoir pressure sensor. 18. The system of claim 15, wherein the manifold pressure monitor further comprises a manifold pressure sensor. 19. The system of claim 15, wherein the ambient pressure monitor further comprises an ambient pressure sensor. 20. The system of claim 15, wherein the switch controller further comprises: a first comparator operable to find an absolute pressure difference between the ambient pressure and the reservoir vacuum pressure; and a second comparator operable to compare a pre-determined threshold value and the absolute pressure difference.