IPC분류정보
국가/구분 |
United States(US) Patent
등록
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국제특허분류(IPC7판) |
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출원번호 |
US-0980813
(2004-11-04)
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우선권정보 |
JP-0386428 (2003-11-17) |
발명자
/ 주소 |
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출원인 / 주소 |
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
19 인용 특허 :
7 |
초록
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A fuel injection system for an internal combustion engine includes a fuel supply pump, a fuel pressure detector, and a control unit. The fuel supply pump supplies pressurized fuel to a fuel injection valve in the internal combustion engine. The fuel pressure detector detects the pressure of the fuel
A fuel injection system for an internal combustion engine includes a fuel supply pump, a fuel pressure detector, and a control unit. The fuel supply pump supplies pressurized fuel to a fuel injection valve in the internal combustion engine. The fuel pressure detector detects the pressure of the fuel supplied. The control unit controls the amount of the fuel supplied based on a deviation between an actual fuel pressure and a target fuel pressure. The control unit includes an integral term calculator and an integral term holder. The integral term calculator adds an integral compensation quantity and a last-time integral term to calculate a this-time integral term based on an integral compensation quantity that is updated according to the deviation. The integral term holder stops the updating of the integral compensation quantity and retains the last-time integral term when a defect in the fuel supply pump is detected.
대표청구항
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1. A fuel injection system for an internal combustion engine, comprising:A a fuel supply pump for supplying fuel under pressure to a fuel injection valve in the internal combustion engine;B a fuel pressure detector for detecting the pressure of the fuel supplied under pressure from the fuel supply p
1. A fuel injection system for an internal combustion engine, comprising:A a fuel supply pump for supplying fuel under pressure to a fuel injection valve in the internal combustion engine;B a fuel pressure detector for detecting the pressure of the fuel supplied under pressure from the fuel supply pump to the fuel injection valve; andC a fuel pressure control unit for controlling the amount of the fuel supplied under pressure from the fuel supply pump based on a deviation between an actual fuel pressure detected by the fuel pressure detector and a target fuel pressure which is set in accordance with an operating condition of the internal combustion engine,wherein the fuel pressure control unit comprises:an integral term calculator for adding an integral compensation quantity and a last-time integral term to calculate a this-time integral term, the integral compensation quantity being updated in accordance with the deviation between the actual fuel pressure and the target fuel pressure; andan integral term holder that stops updating of the integral compensation quantity and retains the last-time integral term when a pressure-supply defect of the fuel supply pump is detected, andwherein the time when a pressure-supply defect of the fuel supply pump is detected indicates any of the period in which a failure or a control defect of the fuel supply pump is detected, the period until the lapse of a predetermined time after a failure or a control defect of the fuel supply pump is no longer detected from the time when the failure or the control defect has been detected, and the period until the operation of the internal combustion engine is stopped from the time when a failure or a control defect of the fuel supply pump has been detected.2. The fuel injection system according to claim 1, wherein the fuel pressure control unit comprises:a fuel pressure determiner for calculating a target fuel pressure in accordance with an operating condition of the internal combustion engine;a proportional term calculator for calculating a this-time proportional term in accordance with a deviation between the actual fuel pressure and the target fuel pressure; anda feedback correction quantity calculator for calculating a feedback correction quantity based on the this-time integral term and the this-time proportional term.3. A fuel injection system for an internal combustion engine, comprising:A a fuel supply pump for supplying fuel under pressure to a fuel injection valve in the internal combustion engine;B a fuel pressure detector for detecting the pressure of the fuel supplied under pressure from the fuel supply pump to the fuel injection valve; andC a fuel pressure control unit for controlling the amount of the fuel supplied under pressure from the fuel supply pump based on a deviation between an actual fuel pressure detected by the fuel pressure detector and a target fuel pressure which is set in accordance with an operating condition of the internal combustion engine,wherein the fuel pressure control unit comprises:an integral term calculator for adding an integral compensation quantity and a last-time integral term to calculate a this-time integral term, the integral compensation quantity being updated in accordance with the deviation between the actual fuel pressure and the target fuel pressure; andan integral term clearer that eliminates the integral compensation quantity and the last-time integral term and calculates a this-time integral term when a pressure-supply defect of the fuel supply pump is detected,wherein the time when a pressure-supply defect of the fuel supply pump is detected indicates any of the period in which a failure or a control defect of the fuel supply pump is detected, the period until the lapse of a predetermined time after a failure or a control defect of the fuel supply pump is no longer detected from the time when the failure or the control defect has been detected, and the period until the operation of the internal combustion engine is stopped from the time when a failure or a control defect of the fuel supply pump has been detected.4. The fuel injection system according to claim 3, wherein the fuel pressure control unit comprises:an injection quantity determiner for calculating a target injection quantity in accordance with an operating condition of the internal combustion engine;a fuel pressure determiner for calculating a target fuel pressure in accordance with an operating condition of the internal combustion engine;a reference control quantity determiner for calculating a reference control quantity for the fuel supply pump based on the target injection quantity set by the injection quantity determiner and the target fuel pressure set by the fuel pressure determiner;a proportional term calculator for calculating a this-time proportional term in accordance with a deviation between the actual fuel pressure and the target fuel pressure; anda feedback correction quantity calculator for calculating a feedback correction quantity relative to the reference control quantity based on the this-time integral term and the this-time proportional term.5. A fuel injection system for an internal combustion engine, comprising:A a fuel supply pump for supplying fuel under pressure to a fuel injection valve in the internal combustion engine;B a fuel pressure detector for detecting the pressure of the fuel supplied under pressure from the fuel supply pump to the fuel injection valve; andC a fuel pressure control unit for calculating a control command value for the fuel supply pump in accordance with an operating condition of the internal combustion engine and applying the control command value to the fuel supply pump to control the amount of the fuel to be supplied under pressure from the fuel supply pump,the fuel pressure control unit comprising:a learning control executioner for making a learning control to learn variations in the amount of fuel supplied under pressure relative to the control command value for the fuel supply pump which variations correspond to a mechanical individual difference or a physical change of the fuel supply pump; anda learning control stopper that stops or inhibits the learning control when a pressure-supply defect of the fuel supply pump is detected,wherein the time when a pressure-supply defect of the fuel supply pump is detected indicates any of the period in which a failure or a control defect of the fuel supply pump is detected, the period until the lapse of a predetermined time after a failure or a control defect of the fuel supply pump is no longer detected from the time when the failure or the control defect has been detected, and the period until the operation of the internal combustion engine is stopped from the time when a failure or a control defect of the fuel supply pump has been detected.6. The fuel injection system according to claim 5, wherein the fuel supply pump is a suction metering type fuel supply pump provided with a suction metering valve for changing the amount of the fuel to be introduced into a pressure chamber in accordance with a drive current value, the suction metering type fuel supply pump pressurizing the fuel to a high-pressure level, which fuel is introduced into the pressure chamber through the suction metering valve, and supplying the high-pressure fuel to the fuel injection valve, andthe learning control executioner makes a learning control to learn variations in an actual pump suction quantity or pump discharge quantity relative to a pump command suction quantity or pump command discharge quantity.7. The fuel injection system according to claim 5,wherein the fuel injection valve is mounted correspondingly to each of cylinders of the internal combustion engine,the fuel supply pump is a high-pressure supply pump having a plurality of pressure-supply systems, the pressure-supply systems being connected respectively to the fuel injection valves through a fuel pipe to supply the fuel under a high-pressure toward the interior of the fuel pipe, anda common rail for temporarily storing the high-pressure fuel discharged from the plurality of pressure-supply systems of the high-pressure supply pump is connected to a certain position of the fuel pipe.8. The fuel injection system according to claim 7, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a failure detector that compares the estimated amount of the fuel supplied for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator, with a first decision value and a second decision value smaller than the first decision value and, when the amount of the fuel supplied under pressure is larger or smaller than the first decision value in only a specific one of the pressure-supply systems, detects a failure of the specific pressure-supply system; anda control defect detector that detects a control defect of the specific pressure-supply system when the amount of the fuel supplied under pressure is larger or smaller than the second decision value in only a specific one of the pressure-supply systems.9. The fuel injection system according to claim 8, wherein, the failure detector defines a state as a complete shortage of fuel and excludes the state from detection when the amount of the fuel supplied under pressure is smaller than the first or the second decision value in all of the pressure-supply systems, andthe failure detector detects a surplus pressure-supply with respect to all of the pressure-supply systems when the amount of the fuel supplied under pressure is larger than the first decision value in all of the pressure-supply systems.10. The fuel injection system according to claim 7, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a pressure-supply quantity difference detector for detecting a difference between a last-time pressure-supply quantity and a this-time pressure-supply quantity with respect to the estimated amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator;a pump failure detector that compares the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems after the calculation by the pressure-supply quantity difference detector with a first decision value and a second decision value smaller than the first decision value anddetects a failure of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the first decision value; anda control defect detector that detects a control defect of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the second decision value.11. The fuel injection system according to claim 8, wherein one of the first and the second decision value is set based on a fuel pressure-supply quantity or a fuel discharge quantity or a fuel discharge pressure for each of the plurality of pressure-supply systems in the case where all the pressure-supply systems in the high-pressure supply pump are normal.12. The fuel injection system according to claim 8,wherein the first or the second decision value is set based on at least one of an engine speed, a fuel injection quantity, and a fuel injection pressure.13. The fuel injection system according to claim 1,wherein the fuel injection valve is mounted correspondingly to each of cylinders of the internal combustion engine,the fuel supply pump is a high-pressure supply pump having a plurality of pressure-supply systems, the pressure-supply systems being connected respectively to the fuel injection valves through a fuel pipe to supply the fuel under a high-pressure toward the interior of the fuel pipe, anda common rail for temporarily storing the high-pressure fuel discharged from the plurality of pressure-supply systems of the high-pressure supply pump is connected to a certain position of the fuel pipe.14. The fuel injection system according to claim 13, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a failure detector that compares the estimated amount of the fuel supplied for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator, with a first decision value and a second decision value smaller than the first decision value and, when the amount of the fuel supplied under pressure is larger or smaller than the first decision value in only a specific one of the pressure-supply systems, detects a failure of the specific pressure-supply system; anda control defect detector that detects a control defect of the specific pressure-supply system when the amount of the fuel supplied under pressure is larger or smaller than the second decision value in only a specific one of the pressure-supply systems.15. The fuel injection system according to claim 14, wherein, the failure detector defines a state as a complete shortage of fuel and excludes the state from detection when the amount of the fuel supplied under pressure is smaller than the first or the second decision value in all of the pressure-supply systems, andthe failure detector detects a surplus pressure-supply with respect to all of the pressure-supply systems when the amount of the fuel supplied under pressure is larger than the first decision value in all of the pressure-supply systems.16. The fuel injection system according to claim 13, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a pressure-supply quantity difference detector for detecting a difference between a last-time pressure-supply quantity and a this-time pressure-supply quantity with respect to the estimated amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator;a pump failure detector that compares the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems after the calculation by the pressure-supply quantity difference detector with a first decision value and a second decision value smaller than the first decision value anddetects a failure of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the first decision value; anda control defect detector that detects a control defect of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the second decision value.17. The fuel injection system according to claim 14, wherein one of the first and the second decision value is set based on a fuel pressure-supply quantity or a fuel discharge quantity or a fuel discharge quantity or a fuel discharge pressure for each of the plurality of pressure-supply systems in the case where all the pressure-supply systems in the high-pressure supply pump are normal.18. The fuel injection system according to claim 14,wherein the first or the second decision value is set based on at least one of an engine speed, a fuel injection quantity, and a fuel injection pressure.19. The fuel injection system according to claim 3,wherein the fuel injection valve is mounted correspondingly to each of cylinders of the internal combustion engine,the fuel supply pump is a high-pressure supply pump having a plurality of pressure-supply systems, the pressure-supply systems being connected respectively to the fuel injection valves through a fuel pipe to supply the fuel under a high-pressure toward the interior of the fuel pipe, anda common rail for temporarily storing the high-pressure fuel discharged from the plurality of pressure-supply systems of the high-pressure supply pump is connected to a certain position of the fuel pipe.20. The fuel injection system according to claim 19, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a failure detector that compares the estimated amount of the fuel supplied for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator, with a first decision value and a second decision value smaller than the first decision value and, when the amount of the fuel supplied under pressure is larger or smaller than the first decision value in only a specific one of the pressure-supply systems, detects a failure of the specific pressure-supply system; anda control defect detector that detects a control defect of the specific pressure-supply system when the amount of the fuel supplied under pressure is larger or smaller than the second decision value in only a specific one of the pressure-supply systems.21. The fuel injection system according to claim 20, wherein, the failure detector defines a state as a complete shortage of fuel and excludes the state from detection when the amount of the fuel supplied under pressure is smaller than the first or the second decision value in all of the pressure-supply systems, andthe failure detector detects a surplus pressure-supply with respect to all of the pressure-supply systems when the amount of the fuel supplied under pressure is larger than the first decision value in all of the pressure-supply systems.22. The fuel injection system according to claim 19, wherein the fuel pressure control unit comprises:a pressure-supply quantity estimator for estimating the amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems;a pressure-supply quantity difference detector for detecting a difference between a last-time pressure-supply quantity and a this-time pressure-supply quantity with respect to the estimated amount of the fuel supplied under pressure for each of the plurality of pressure-supply systems after the estimation by the pressure-supply quantity estimator;a pump failure detector that compares the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems after the calculation by the pressure-supply quantity difference detector with a first decision value and a second decision value smaller than the first decision value anddetects a failure of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the first decision value; anda control defect detector that detects a control defect of the pressure-supply system concerned when the difference between the last-time pressure-supply quantity and the this-time pressure-supply quantity for each of the plurality of pressure-supply systems is larger or smaller than the second decision value.23. The fuel injection system according to claim 20, wherein one of the first and the second decision value is set based on a fuel pressure-supply quantity or a fuel discharge quantity or a fuel discharge pressure for each of the plurality of pressure-supply systems in the case where all the pressure-supply systems in the high-pressure supply pump are normal.24. The fuel injection system according to claim 20,wherein the first or the second decision value is set based on at least one of an engine speed, a fuel injection quantity, and a fuel injection pressure.
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