Fuel injection control for internal combustion engines

Claim 1

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said control signal supplying step supplies electric control signals for cutting off the injection of fuel to said malfunctioning injector and the injector of at least one of said cylinders has a particular order of arrangement relation with the order of arrangement of the other one of said cylinders associated with said malfunctioning injector from the standpoint of balance in the generation of power output.

Claim 2

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said control signal supplying step supplies electric control signals for cutting off the injection of fuel to said malfunctioning injector and the injector of at least one of said cylinders has a particular order of arrangement relation with the order of arrangement of the other one of said cylinders associated with said malfunctioning injector from the standpoint of balance in the generation of power output.

Claim 3

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said control signal supplying step supplies to said malfunctioning injector electric control signals for cutting off the injection of fuel therefrom and also supplies electric control signals with reduced number of events of fuel injection to the injector of at least one of said cylinders having a particular order of arrangement relation with the order of arrangement of the other one of said cylinders associated with said malfunctioning injector from the standpoint of balance in the generation of power output.

Claim 4

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said control signal supplying step supplies to said malfunctioning injector electric control signals for cutting off the injection of fuel therefrom and also supplies electric control signals with reduced number of events of fuel injection to the injector of at least one of said cylinders having a particular order of arrangement relation with the order of arrangement of the other one of said cylinders associated with said malfunctioning injector from the standpoint of balance in the generation of power output.

Claim 6

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injection of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said malfunctioning injector discriminated by said malfunction discriminating step has a malfunction in the fuel measuring means thereof.

Claim 7

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injection of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said malfunctioning injector discriminated by said malfunction discriminating step has a malfunction in the fuel measuring means thereof.

Claim 8

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said malfunctioning injector discriminated by said malfunction discriminating step has a malfunction in the injection actuating means thereof.

Claim 9

A method of controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors provided one for each cylinder of the engine and each responsive to electric signals to control the injection of fuel therefrom, said method comprising the steps of: detecting an operating condition of said engine by sensor means; discriminating the presence or absence of a malfunction in the injection of fuel from each said injector in accordance with said engine operating condition detected by said sensor means; and supplying, upon discrimination of a malfunction in the injector of any one of said cylinders, to said malfunctioning injector electric control signals which are required for continued operation of said engine but different from those required for a normal operation of said engine, wherein said malfunctioning injector discriminated by said malfunction discriminating step has a malfunction in the injection actuating means thereof.

Claim 10

An apparatus for controlling the injection of fuel into an internal combustion engine comprising: a plurality of unit injector means provided one for each cylinder of said engine, each of said injector means including forced delivery means having a piston and a plunger coupled to said piston to force out fuel in a pump working fluid chamber below said plunger in response to downward movement of said piston, an injection nozzle for injecting said forced-out fuel, valve means for changing a hydraulic pressure in a piston working fluid chamber above said piston to control the vertical movement of said piston and said plunger, and an actuator for measuring the quantity of fuel supplied to said pump working fluid chamber below said plunger corresponding to the quantity of fuel to be injected; and control means for controlling each said injector means by control signals generated in accordance with data applied from sensor means for detecting operating conditions of said engine, so that when a fault occurs in a part of at least one of said injector means with said at least one injector means still capable of supplying fuel, the operation of at least one of the fuel measuring actuator and the valve means of said at least one injector means is controlled so as to operate said at least one injector means in a fault mode of operation and thereby control the quantity of fuel injected.

Claim 11

An apparatus for controlling the injection of fuel into an internal combustion engine comprising: a plurality of unit injector means provided one for each cylinder of said engine, each of said injector means including forced delivery means having a piston and a plunger coupled to said piston to force out fuel in a pump working fluid chamber below said plunger in response to downward movement of said piston, an injection nozzle for injecting said forced-out fuel, valve means for changing a hydraulic pressure in a piston working fluid chamber above said piston to control the vertical movement of said piston and said plunger, and an actuator for measuring the quantity of fuel supplied to said pump working fluid chamber below said plunger corresponding to the quantity of fuel to be injected; and control means for controlling each said injector means by control signals generated in accordance with data applied from sensor means for detecting operating conditions of said engine, so that when a fault occurs in a part of at least one of said injector means with said at least one injector means still capable of supplying fuel, the operation of at least one of the fuel measuring actuator and the valve means of said at least one injector means is controlled so as to operate said at least one injector means in a fault mode of operation and thereby control the quantity of fuel injected.