Fuel Injection Control Device for Use With an Internal Combustion Engine

1. A fuel injection control system for an internal combustion engine having a fuel injection valve, comprising: a crank angle sensor for producing a crank angle signal for each predetermined angle of crank revolution of said engine; a driving circuit associated with said fuel injection valve for controlling the operation of said fuel injection valve for performing fuel injections in controlled amounts and at controlled timing; a microcomputer adapted to distinguish a first crank angle signal produced immediately after cranking action starts and subsequent crank angle signals, said microcomputer being operative for counting said crank angle signals and comparing said counted crank angle signals with a preset value and producing a driving signal for operating said driving circuit when said counted value reaches said preset value, and said microcomputer being operative to set said preset value at one prior to receipt of said first crank angle signal so that a first fuel injection is performed in response to said first crank angle signal and operative to set said preset value to a given normal value before receipt of subsequent crank angle signals so that subsequent fuel injections are performed when a given number of crank angle signals are inputed.

2. A fuel injection control system as defined in claim 1, wherein said microcomputer executes a program organized so as to effect said first fuel injection when said first crank angle signal is received, and to effect subsequent fuel injections whenever said given number of crank angle signals are received.

3. A fuel injection control system as defined in claim 1 or 2, wherein said microcomputer includes a memory for storing fuel injection values in a form of a table to be read out in terms of an engine temperature and being associated with an engine temperature sensor producing an engine temperature signal indicative of the engine temperature, said microcomputer being responsive to said engine temperature signal to read out a value corresponding to the fuel injection amount to be injected based on the engine temperature from the table in said memory.

4. A fuel injection control system as defined in claim 3, wherein said microcomputer is programmed to calculate a fuel injection amount for the first fuel injection to be approximately one and a half times the usual fuel amount to be injected during said subsequent fuel injections which correspond to the same engine temperature.

5. A fuel injection control device for an internal combustion engine for controlling fuel injection timing and fuel injection amount based on various engine operation parameters, which control device includes a microcomputer controlled by a central processing unit, and memory unit, a crank angle sensor for detecting crank angle and generating a crank angle signal per each given crank revolution angle and a fuel injection valve with an actuator for operating the fuel injection valve responsive to a fuel injection signal generated and fed from the microcomputer, wherein the improvement comprises: said microcomputer further including a counter means for counting up the crank angle signals and generating a fuel injection signal when the count of crank angle signals becomes equal to a preset value, said microcomputer being operative to discriminate between a first crank angle signal and subsequent crank angle signals, and to set said preset value to a first value prior to said first crank angle signal and to a given value prior to said subsequent crank angle signals, wherein said preset value for the first fuel injection is less then that for subsequent fuel injections for reducing lag of response from start-up operation.

6. A fuel injection control device as defined in claim 5, wherein said memory unit contains a table storing various predetermined values of fuel injection amount and said central processing unit reads out one of said predetermined values based on an engine temperature measured by an engine temperature sensor.

7. A fuel injection control device as defined in claim 6, wherein said microcomputer further comprises a means for generating clock signals, means for generating a count of the clock signals, means for comparing said count of clock signals with the predetermined value corresponding to the determined fuel injection amount, and means for generating a command signal for making said actuator inoperative, whereby said command signal defines the duration of opening of said fuel injection valve in cooperation with said fuel injection signal.

8. A fuel injection control system as defined in claim 5, wherein said preset value for determining the fuel injection timing is set in said memory unit, said microcomputer being operative to discriminate between said first fuel injection and subsequent fuel injections based on an engine starter switch position and engine inoperative conditions, and wherein said microcomputer is operative to set said preset value to 1 in order to effect said first fuel injection in response to the first crank angle signal.

9. A fuel injection control device as defined in claim 5 or 8, wherein said subsequent fuel injections following the first fuel injection are effected per one cycle of crank shaft revolution.

10. A fuel injection control system for a fuel injection type internal combustion engine comprising: a crank angle sensor for determining crank revolution angle and generating a crank angle signal per each given crank revolution angle; an engine temperature sensor for determining engine temperature; a fuel injection valve with an actuator for controlling opening and closing of said valve; a control means for counting up said crank angle signals and comparing the count of crank angle signals with a preset value to determine fuel injection timing, said control means generating a fuel injection signal when said count of crank angle signals becomes equal to said preset value, said control means being operative to distinguish between a first crank angle signal and subsequent crank angle signals, said control means being operative to set said preset value at 1 prior to said first crank angle signal, and to set said preset value at a given value prior to said subsequent crank angle signals; and control means for storing fuel injection amounts corresponding to engine operation parameters in a form of a table, said control means determining the fuel injection amount from said table, and setting the fuel injection amount for the first fuel injection to an initial preset value independent from said table, but based on engine temperature.

11. A fuel injection control device as defined in claim 10, wherein said control means determine the fuel injection amount based, at least in part, on the engine temperature determined by said engine temperature sensor for said subsequent fuel injections.

12. A fuel injection control device as defined in claim 10 or 11, wherein said fuel injection amount for the first fuel injection is approximately one and a half times the fuel injection amount to be injected in subsequent fuel injections based on similar operation parameters.

13. A fuel injection control device as defined in claim 10 or 11, wherein said control means comprises a microcomputer system.

14. In a fuel injection control device for an internal combustion engine for controlling fuel injection amount and fuel injection timing based on various engine operation parameters, which control device includes a microcomputer controlled by a central processing unit, memory unit, and counters, a crank angle sensor for detecting crank angle and generating a crank angle signal per each given crank revolution angle and a fuel injection valve responsive to a fuel injection pulse generated and fed from the microcomputer, a method for controlling fuel injection comprising the steps of: detecting a first crank angle signal produced immediately after cranking action starts; producing a first fuel injection pulse for performing a first fuel injection in response to said first crank angle signal; and counting said crank angle signals produced subsequent to said first crank angle signal and comparing the counted crank angle signal number with a first preset value to determine fuel injection timing for subsequent fuel injections.

15. A method as defined in claim 14, wherein said method further comprises the steps of: generating clock signal pulses, counting up said clock signal pulses to produce a counted clock signal, comparing the counted clock signal with a value corresponding to a determined fuel injection amount, and, when the counted clock signal becomes equal to said value indicative of the fuel injection amount, generating a command to close said fuel injection valve.

16. A method as defined in claim 14 or 15, wherein said first preset value is set to 1 prior to detecting the first crank angle signal and is set to 3 prior to detecting subsequent crank angle signals, and wherein said crank angle signal is generated per every 120.degree. of crank revolution.

17. In an electronically controlled single-point fuel injection device for an internal combustion engine, said fuel injection device being of the type wherein fuel injection is effected simultaneously to all cylinders, including a fuel injection valve, a microcomputer and means for generating a crank angle signal at given crank revolution angles, said microcomputer receiving and being responsive to said crank angle signals for effecting fuel injection whenever the number of crank angle signals is more than that of a predetermined number; the improvement comprising: said microcomputer being operative for discriminating between the first fuel injection effected immediately after cranking action starts and subsequent fuel injections being effected thereafter, said microcomputer comparing the number of received crank angle signals to a preset value, said preset value having a first value for effecting the first fuel injection and a second, greater value, for effecting subsequent fuel injections, said microcomputer generating a driving signal when the number of received crank angle signals equals said preset value; and a driving circuit for controlling opening and closing of a fuel injection value, said driving circuit being responsive to said driving signal generated by said microcomputer to open said fuel injection valve, whereby said microcomputer effects said first fuel injection when the number of crank angle signals is equal to said first value and effects subsequent fuel injections whenever a predetermined number of crank angle signals are received, equal to said second value.

18. A fuel injection control device for an internal combustion engine for controlling fuel injection timing and fuel injection amount based on various engine operation parameters, which control device includes a microcomputer controlled by a central processing unit, and memory unit, a crank angle sensor for detecting crank angle and generating a crank angle signal per each given crank revolution angle and a fuel injection valve with an actuator for operating the fuel injection valve responsive to a fuel injection signal generated and fed from the microcomputer, wherein the improvement comprises: said microcomputer being operative for counting up the crank angle signals and generating a fuel injection signal when the count of crank angle signals becomes equal to a preset value and being responsive to the first crank angle signal to produce the first fuel injection signal and being operative for discriminating between a first fuel injection and subsequent fuel injections, wherein the first fuel injection is effected in response to the first crank angle signal and the subsequent fuel injections are effected whenever counted crank angle signals become equal to a preset value.

19. A fuel injection control system of the type wherein fuel injection is effected simultaneously for all cylinders of an internal combustion engine, comprising: a crank angle sensor for determining crank revolution angle and generating a crank angle signal per each given crank revolution angle; an engine temperature sensor for determining engine temperature; a fuel injection valve with an actuator for controlling opening and closing of said valve; a control means for counting up said crank angle signals and comparing the counted crank angle signal with a first preset value to determine fuel injection timing, said control means generating a fuel injection signal when said counted crank angle signal becomes equal to said first preset value and said control means discriminating between a first fuel injection at engine cranking and subsequent fuel injections, and setting a different preset value when the first fuel injection is effected to reduce the first preset value in relation to that for the subsequent fuel injections so that the first fuel injection is effected in response to the first crank angle signal.

20. A fuel injection control system for an internal combustion engine, comprising: a fuel injection valve for injecting a controlled amount of a fuel at a controlled timing; a crank angle sensor for producing a crank angle signal for each predetermined angle of crank revolution of said engine; an engine temperature sensor for detecting temperature of said engine and producing an engine temperature signal having a value representative of said detected engine temperature; a controller for producing fuel injection signals having a value representative of fuel injection amount to be injected at a given timing, said controller including: a flag register having set and reset states, said flag register assuming said set state responsive to the first crank angle signal produced immediately after cranking action starts; a preset value register for storing a preset value defining fuel injection timing in relation to engine revolution, said preset value register being associated with said flag register, said preset value register being preset to a first value when said flag register is in said reset state and being preset to a second value when said flag register is in said set state; a counter for counting up crank angle signals and producing a counter signal having a value indicative of said counted crank angle signals; a comparator for comparing said set value of said preset value register and said counter signal value to produce a comparator signal when said counter signal value is equal to said preset value; and a signal generator for producing said fuel injection signal in response to said comparator signal, said signal generator being responsive to said engine temperature signal to determine said fuel injection signal value dependent on said engine temperature signal value.

21. The fuel injection control system as set forth in claim 1, further comprising a memory incorporated in said controller and adapted to store values respectively indicative of fuel injection amounts in a form of a table which is to be read out in terms of the engine temperature signal value, and said signal generator being associated with said memory for reading out the stored values according to the engine temperature signal values inputted.

22. The fuel injection control system as set forth in claim 20 or 21, wherein said counter is associated with said signal generator and is responsive to said fuel injection signal to clear said counter value.

23. The fuel injection control system as set forth in claim 22, wherein said signal generator determines a fuel injection amount for the first fuel injection, said first fuel injection amount being approximately one and a half times that of the usual fuel injection amount to be injected which corresponds to the engine temperature.

24. The fuel injection control system as set forth in claim 20, wherein said engine includes a starter having an ON position and an OFF position, wherein said flag register is maintained in said set state as long as said starter switch is held in said OFF position and is placed in said reset state in response to said first crank angle signal.