Accumulator fuel injection apparatus compensating for injector individual variability
First Claim
1. An accumulator fuel injection system for an internal combustion engine comprising:
- a common rail working to accumulate fuel at a given pressure;
an injector which injects the fuel supplied from said common rail to an internal combustion engine; and
an injector controller working to output an injection pulse signal to actuate said injector, said injector controller determining a required injection quantity as a function of a given operating condition of the engine to define an effective injection pulse width and adding the effective injection pulse width to an ineffective injection pulse width to determine an injection pulse width that is a width of the injection pulse signal, the effective injection pulse width defining a duration for which the injector actually injects the fuel into the engine, the ineffective injection pulse width being given as a function of a time lag in operation of said injector, wherein said injector controller is designed to perform (a) an injection pulse width changing function to change the injection pulse width from a smaller value at which said injector is insensitive to the injection pulse signal to produce no spray of the fuel to a greater value at which said injector is sensitive to the injection pulse signal to spray the fuel actually, (b) a pressure amplitude measuring function to measure an amplitude of pulsations of pressure of the fuel within said common rail a given period of time after the injection pulse signal, as changed in the injection pulse width by said injection pulse width changing function, is outputted to said injector, and (c) an ineffective injection pulse width determining function to determine the ineffective injection pulse width based on the injection pulse width, as having been changed by said injection pulse width changing function and outputted to said injector when the amplitude measured by said pressure amplitude measuring function has exceeded a preselected level.
1 Assignment
0 Petitions
Accused Products
Abstract
A common rail injection system for internal combustion diesel engines is provided which is designed to correct a limit of width of an ineffective injection command pulse signal which is to be applied to each fuel injector, but causes the injector to produce no spray of fuel in order to minimize a variation in quantity of fuel injected to the engine between the injectors arising from the individual variability or aging of the injectors. The system works to changes the width of a pilot injection command pulse signal to search a value thereof when an engine operation variation such as a change in speed of the engine exceeds or decreases below a threshold at which the injector may be viewed as having sprayed the fuel actually or stopped spraying the fuel actually and determines the limit of width of the ineffective injection command pulse signal using the searched value.
-
Citations
16 Claims
-
1. An accumulator fuel injection system for an internal combustion engine comprising:
-
a common rail working to accumulate fuel at a given pressure;
an injector which injects the fuel supplied from said common rail to an internal combustion engine; and
an injector controller working to output an injection pulse signal to actuate said injector, said injector controller determining a required injection quantity as a function of a given operating condition of the engine to define an effective injection pulse width and adding the effective injection pulse width to an ineffective injection pulse width to determine an injection pulse width that is a width of the injection pulse signal, the effective injection pulse width defining a duration for which the injector actually injects the fuel into the engine, the ineffective injection pulse width being given as a function of a time lag in operation of said injector, wherein said injector controller is designed to perform (a) an injection pulse width changing function to change the injection pulse width from a smaller value at which said injector is insensitive to the injection pulse signal to produce no spray of the fuel to a greater value at which said injector is sensitive to the injection pulse signal to spray the fuel actually, (b) a pressure amplitude measuring function to measure an amplitude of pulsations of pressure of the fuel within said common rail a given period of time after the injection pulse signal, as changed in the injection pulse width by said injection pulse width changing function, is outputted to said injector, and (c) an ineffective injection pulse width determining function to determine the ineffective injection pulse width based on the injection pulse width, as having been changed by said injection pulse width changing function and outputted to said injector when the amplitude measured by said pressure amplitude measuring function has exceeded a preselected level. - View Dependent Claims (2, 3, 4)
-
-
5. An accumulator fuel injection system for an internal combustion engine comprising:
-
a common rail working to accumulate fuel at a given pressure;
an injector which injects the fuel supplied from said common rail to an internal combustion engine; and
an injector controller working to output an injection pulse signal to actuate said injector, said injector controller determining a required injection quantity as a function of a given operating condition of the engine to define an effective injection pulse width and adding the effective injection pulse width to an ineffective injection pulse width to determine an injection pulse width that is a width of the injection pulse signal, the effective injection pulse width defining a duration for which the injector actually injects the fuel into the engine, the ineffective injection pulse width being given as a function of a time lag in operation of said injector, wherein said injector controller is designed to perform (a) an injection pulse width changing function to change the injection pulse width from a greater value at which said injector is sensitive to the injection pulse signal to spray the fuel actually to a smaller value at which said injector is insensitive to the injection pulse signal to produce no spray of the fuel, (b) a pressure amplitude measuring function to measure an amplitude of pulsations of pressure of the fuel within said common rail a given period of time after the injection pulse signal, as changed in the injection pulse width by said injection pulse width changing function, is outputted to said injector, and (c) an ineffective injection pulse width determining function to determine, as the ineffective injection pulse width, the injection pulse width, as having been changed by said injection pulse width changing function and outputted to said injector, when the amplitude measured by said pressure amplitude measuring function has dropped below a preselected level. - View Dependent Claims (6, 7, 8)
-
-
9. An accumulator fuel injection system for an internal combustion engine comprising:
-
a common rail working to accumulate fuel at a given pressure;
an injector which injects the fuel supplied from said common rail to an internal combustion engine; and
an injector controller working to output injection pulse signals to actuate said injector, said injector controller determining a required injection quantity as a function of a given operating condition of the engine to define an effective injection pulse width and adding the effective injection pulse width to an ineffective injection pulse width to determine an injection pulse width that is a width of each of the injection pulse signals, the effective injection pulse width defining a duration for which the injector actually injects the fuel into the engine, the ineffective injection pulse width being given as a function of a time lag in operation of said injector, wherein said injector controller is designed to perform (a) a multi-injection function in each operation cycle of a cylinder of the engine to perform a multi-injection mode in which a main injection of the fuel into the engine is made and a pre-injection of fuel into the engine is made before the main injection and to output one of the injection pulse signals as a main injection pulse signal to said injector to initiate the main injection and one of the injection pulse signals as a pre-injection pulse signal to said injector to initiate the pre-injection, (b) an injection pulse width setting function to set a main injection pulse width that is a width of the main injection pulse signal to a value causing the engine to produce torque required to maintain running of the engine, (c) an injection pulse width changing function to change a pre-injection pulse width that is a width of the pre-injection pulse signal from a smaller value at which said injector is insensitive to the pre-injection pulse signal to produce no spray of the fuel to a greater value at which said injector is sensitive to the pre-injection pulse signal to spray the fuel actually, (d) an engine operation variation measuring function to measure a preselected engine operation variation within a given period of time after the pre-injection pulse signal, as changed in the pre-injection pulse width by said injection pulse width changing function, is outputted to said injector, and (e) an ineffective injection pulse width determining function to determine the ineffective injection pulse width based on the pre-injection pulse width, as having been changed by said injection pulse width changing function and outputted to said injector when the engine operation variation, as measured by the engine operation variation measuring function, has reached a preselected value. - View Dependent Claims (10, 11, 12)
-
-
13. An accumulator fuel injection system for an internal combustion engine comprising:
-
a common rail working to accumulate fuel at a given pressure;
an injector which injects the fuel supplied from said common rail to an internal combustion engine; and
an injector controller working to output injection pulse signals to actuate said injector, said injector controller determining a required injection quantity as a function of a given operating condition of the engine to define an effective injection pulse width and adding the effective injection pulse width to an ineffective injection pulse width to determine an injection pulse width that is a width of each of the injection pulse signals, the effective injection pulse width defining a duration for which the injector actually injects the fuel into the engine, the ineffective injection pulse width being given as a function of a time lag in operation of said injector, wherein said injector controller is designed to perform (a) a multi-injection function in each operation cycle of a cylinder of the engine to perform a multi-injection mode in which a main injection of the fuel into the engine is made and a pre-injection of fuel into the engine is made before the main injection and to output one of the injection pulse signals as a main injection pulse signal to said injector to initiate the main injection and one of the injection pulse signals as a pre-injection pulse signal to said injector to initiate the pre-injection, (b) an injection pulse width setting function to set a main injection pulse width that is a width of the main injection pulse signal to a value causing the engine to produce torque required to maintain running of the engine, (c) an injection pulse width changing function to change a pre-injection pulse width that is a width of the pre-injection pulse signal from a greater value at which said injector is sensitive to the pre-injection pulse signal to spray the fuel actually to a smaller value at which said injector is insensitive to the pre-injection pulse signal to produce no spray of the fuel, (d) an engine operation variation measuring function to measure a preselected engine operation variation within a given period of time after the pre-injection pulse signal, as changed in the pre-injection pulse width by said injection pulse width changing function, is outputted to said injector, and (e) an ineffective injection pulse width determining function to determine the ineffective injection pulse width based on the pre-injection pulse width, as having been changed by said injection pulse width changing function and outputted to said injector when the engine operation variation, as measured by the engine operation variation measuring function, has reached a preselected value. - View Dependent Claims (14, 15, 16)
-
Specification