초록 ▼

An engine ECU performs a program including the steps of calculating an amount of the fuel required to be discharged from high-pressure fuel pumps (the required discharge amount), determining whether one high-pressure fuel pump can be stopped, and if not, determining whether the required discharge am

An engine ECU performs a program including the steps of calculating an amount of the fuel required to be discharged from high-pressure fuel pumps (the required discharge amount), determining whether one high-pressure fuel pump can be stopped, and if not, determining whether the required discharge amount exceeds a maximum possible discharge amount of one high-pressure fuel pump of smaller capability, and if not, causing the two high-pressure fuel pumps to discharge the fuel in approximately equal amount, or if so, causing the high-pressure fuel pump of smaller capability to discharge the fuel of the maximum possible discharge amount and causing the high-pressure fuel pump of larger capability to discharge the fuel of the amount obtained by subtracting the discharge amount of the high-pressure fuel pump of smaller capability from the required discharge amount.

대표청구항 ▼

What is claimed is: 1. A control device of a high-pressure fuel system of an internal combustion engine having a fuel injection mechanism for injecting a fuel into a cylinder, the high-pressure fuel system including a plurality of high-pressure fuel pumps driven by the internal combustion engine, t

What is claimed is: 1. A control device of a high-pressure fuel system of an internal combustion engine having a fuel injection mechanism for injecting a fuel into a cylinder, the high-pressure fuel system including a plurality of high-pressure fuel pumps driven by the internal combustion engine, the control device comprising: a detection unit for detecting an amount of the fuel required to be discharged from said high-pressure fuel pumps; and a control unit for controlling said plurality of high-pressure fuel pumps such that the fuel discharged from said plurality of high-pressure fuel pumps is supplied to a plurality of such fuel injection mechanisms, said control unit including a discharge ratio determination portion that determines a fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged. 2. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1, further comprising a storage unit for storing a characteristic of each of said high-pressure fuel pumps, wherein said discharge ratio determination portion determines the fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged, based on said characteristics. 3. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1, wherein said discharge ratio determination portion calculates an amount of the fuel to be discharged from each of said high-pressure fuel pumps based on said fuel discharge ratio, and calculates a drive duty of each of said high-pressure fuel pumps based on said amount of the fuel to be discharged therefrom. 4. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1, wherein said discharge ratio determination portion determines the fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged, with an amount of the fuel relieved from said high-pressure fuel pumps being taken into account. 5. The control device of a high-pressure fuel system of an internal combustion engine according to claim 4, wherein said control unit determines whether it is possible to stop discharge of the fuel from at least one of said high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged. 6. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1, wherein said control unit controls said high-pressure fuel pumps such that discharge of the fuel from at least one of said high-pressure fuel pumps is stopped when fuel injection from said fuel injection mechanism is stopped. 7. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1, wherein when said plurality of high-pressure fuel pumps include a high-pressure fuel pump having a different discharge characteristic, said discharge ratio determination portion determines the fuel discharge ratio among said plurality of high-pressure fuel pumps such that the amount of the fuel discharged from the high-pressure fuel pump having the different discharge characteristic is approximately equal to the amount of the fuel discharged from another one of said high-pressure fuel pumps. 8. The control device of a high-pressure fuel system of an internal combustion engine according to any of claims 1-7, wherein when at least one of said plurality of high-pressure fuel pumps has a maximum possible discharge amount that is smaller than said amount of the fuel required to be discharged, said discharge ratio determination portion determines the fuel discharge ratio among said plurality of high-pressure fuel pumps such that the high-pressure fuel pump having its maximum possible discharge amount smaller than said amount of the fuel required to be discharged will discharge the fuel of the maximum possible discharge amount and that another one of said high-pressure fuel pumps will discharge the fuel of the amount corresponding to a difference between said amount of the fuel required to be discharged and said maximum possible discharge amount. 9. The control device of a high-pressure fuel system of an internal combustion engine according to claim 1. further comprising: an operation unit for activating said plurality of high-pressure fuel pumps one by one using a predetermined drive duty; and a determination unit for determining whether the pump is faulty or not based on a change in fuel pressure as a result of said activation. 10. The control device of a high-pressure fuel system of an internal combustion engine according to claim 9, wherein said determination unit determines whether the pump is faulty or not based on a degree of increase of said fuel pressure. 11. A control device of a high-pressure fuel system of an internal combustion engine having fuel injection means for injecting a fuel into a cylinder, the high-pressure fuel system including a plurality of high-pressure fuel pumps driven by the internal combustion engine, the control device comprising: detection means for detecting an amount of the fuel required to be discharged from said high-pressure fuel pumps; and control means for controlling said plurality of high-pressure fuel pumps such that the fuel discharged from said plurality of high-pressure fuel pumps is supplied to a plurality of such fuel injection means, said control means including discharge ratio determination means for determining a fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged. 12. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, further comprising storage means for storing a characteristic of each of said high-pressure fuel pumps, wherein said discharge ratio determination means includes means for determining the fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged, based on said characteristics. 13. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, wherein said discharge ratio determination means includes p1 means for calculating an amount of the fuel to be discharged from each of said high-pressure fuel pumps based on said fuel discharge ratio, and means for calculating a drive duty of each of said high-pressure fuel pumps based on said amount of the fuel to be discharged therefrom. 14. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, wherein said discharge ratio determination means includes means for determining the fuel discharge ratio among said plurality of high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged, with an amount of the fuel relieved from said high-pressure fuel pumps being taken into account. 15. The control device of a high-pressure fuel system of an internal combustion engine according to claim 14, wherein said control means further includes means for determining whether it is possible to stop discharge of the fuel from at least one of said high-pressure fuel pumps in accordance with said amount of the fuel required to be discharged. 16. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, wherein said control means further includes means for controlling said high-pressure fuel pumps such that discharge of the fuel from at least one of said high-pressure fuel pumps is stopped when fuel injection from said fuel injection means is stopped. 17. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, wherein said discharge ratio determination means includes means for determining the fuel discharge ratio among said plurality of high-pressure fuel pumps such that, when said plurality of high-pressure fuel pumps include a high-pressure fuel pump having a different discharge characteristic, the amount of the fuel discharged from the high-pressure fuel pump having the different discharge characteristic is approximately equal to the amount of the fuel discharged from another one of said high-pressure fuel pumps. 18. The control device of a high-pressure fuel system of an internal combustion engine according to any of claims 1-7, wherein said discharge ratio determination means includes means for determining the fuel discharge ratio among said plurality of high-pressure fuel pumps such that, when at least one of said plurality of high-pressure fuel pumps has a maximum possible discharge amount that is smaller than said amount of the fuel required to be discharged, the high-pressure fuel pump having its maximum possible discharge amount smaller than said amount of the fuel required to be discharged will discharge the fuel of the maximum possible discharge amount and that another one of said high-pressure fuel pumps will discharge the fuel of the amount corresponding to a difference between said amount of the fuel required to be discharged and said maximum possible discharge amount. 19. The control device of a high-pressure fuel system of an internal combustion engine according to claim 11, further comprising: operation means for activating said plurality of high-pressure fuel pumps one by one using a predetermined drive duty; and determination means for determining whether the pump is faulty or not based on a change in fuel pressure as a result of said activation. 20. The control device of a high-pressure fuel system of an internal combustion engine according to claim 19, wherein said determination means includes means for determining whether the pump is faulty or not based on a degree of increase of said fuel pressure.