Fuel injection control system for an internal combustion engine and method thereof

Claim 5

A fuel injection control system for an internal combustion engine, having a fuel injector for injecting a fuel into said engine, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; setting means for setting a fuel injection pulse width in accordance with said operating conditions of said engine; and generating means for generating a first pulse at an intake stroke of said engine and a second pulse at an exhaust stroke of said engine, when said determining means determines that said engine does not perform stable combustion at the engine start, the total width of said first and second pulses corresponding to said fuel injection pulse width set by said setting means.

Claim 6

A fuel injection control system for an internal combustion engine, having a fuel injector for injecting a fuel into said engine, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; setting means for setting a fuel injection pulse width in accordance with said operating conditions of said engine; and generating means for generating a first pulse at an intake stroke of said engine and a second pulse at an exhaust stroke of said engine, when said determining means determines that said engine does not perform stable combustion at the engine start, the total width of said first and second pulses corresponding to said fuel injection pulse width set by said setting means.

Claim 7

A fuel injection control system for an internal combustion engine, having a temperature sensing means for sensing an engine temperature and for producing a temperature signal and a fuel injector for injecting a fuel into said engine, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; deciding means for deciding a fuel injection finishing timing within an opening period of an intake valve in response to said temperature signal; setting means for setting a fuel injection pulse width for said injector in accordance with said operating conditions of said engine; and generating means for generating a pulse having said fuel injection pulse width so as to finish said pulse at said fuel injection finishing time when said determining means determines that said engine performs stable combustion at the engine start.

Claim 8

A fuel injection control system for an internal combustion engine, having a temperature sensing means for sensing an engine temperature and for producing a temperature signal and a fuel injector for injecting a fuel into said engine, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; deciding means for deciding a fuel injection finishing timing within an opening period of an intake valve in response to said temperature signal; setting means for setting a fuel injection pulse width for said injector in accordance with said operating conditions of said engine; and generating means for generating a pulse having said fuel injection pulse width so as to finish said pulse at said fuel injection finishing time when said determining means determines that said engine performs stable combustion at the engine start.

Claim 9

The method according to claim 1, wherein the width of each of said first pulse and said second pulse is half of said fuel injection pulse width.

Claim 10

The method according to claim 1 further comprising: generating a pulse with said fuel injection pulse width so as to finish said pulse at said fuel injection finishing time when said engine performs stable combustion at the engine start.

Claim 11

The method according to claim 6, wherein said determining step comprises: comparing an engine speed with a predetermined value, thereby determining that said engine does not perform stable combustion when said engine speed is lower than said predetermined value and that said engine performs stable combustion when said engine speed is higher than said predetermined value.

Claim 12

The method according to claim 6, wherein said determining step comprises: comparing a temperature of said engine with a preset value; and comparing an engine speed with a first predetermined value when said temperature is lower than said preset value and with a second predetermined value when said temperature is higher than said preset value, thereby determining that said engine does not perform stable combustion when said engine speed is lower than either one of said first and second predetermined values and that said engine performs stable combustion when said engine speed is higher than either one of said first and second predetermined values.

Claim 13

The method according to claim 8, wherein said determining step further comprises: comparing said engine speed with a third predetermined value after it is once determined that said engine performs stable combustion, said third predetermined value being smaller than said second predetermined value, thereby determining that said engine is back to unstable combustion when said engine speed becomes lower than said third predetermined value.

Claim 14

The method according to claim 2, wherein said generating step comprises: calculating a fuel injection start time based on said fuel injection finishing time and said set fuel injection pulse width.

Claim 15

The method according to claim 2, further comprising: generating a first pulse at an intake stroke of said engine and a second pulse at an exhaust stroke of said engine, when it is determined that said engine does not perform stable combustion at the engine start, the total width of said first and second pulses corresponding to said set fuel injection pulse width.

Claim 16

The method according to claim 11, wherein said determining step comprises: comparing an engine speed with a predetermined value, thereby determining that said engine performs stable combustion when said engine speed is higher than said predetermined value and that said engine does not perform stable combustion when said engine speed is lower than said predetermined value.

Claim 17

The method according to claim 11, wherein said determining step comprises: comparing a temperature of said engine with a preset value; and comparing an engine speed with a first predetermined value when said temperature is lower than said preset value and with a second predetermined value when said temperature is higher than said preset value, said second predetermined value being smaller than said first predetermined value, thereby determining that said engine performs stable combustion when said engine speed is higher than either one of said first and second predetermining values and that said engine does not perform stable combustion when said engine speed is lower than either one of said first and second predetermined values.

Claim 18

The method according to claim 13, wherein said determining step further comprises: comparing said engine speed with a third predetermined value after it is once determined that said engine performs stable combustion, said third predetermined value being smaller than said second predetermined value, thereby determining that said engine is back to unstable combustion when said engine speed becomes lower than said third predetermined value.

Claim 19

The system according to claim 3, wherein said generating means is adapted to set a width of each of said first pulse and said second pulse as half of said fuel injection pulse width.

Claim 20

The system according to claim 3 wherein said generating means is adapted to generate a pulse having said fuel injection pulse width so as to finish said pulse at said fuel injection finishing timing when said engine performs stable combustion at the engine start.

Claim 21

The system according to claim 16, further comprising: engine speed sensing means for sensing an engine speed and producing an engine speed signal; said determining means including comparing means responsive to said engine speed signal for comparing said engine speed with a predetermined value and for determining that said engine does not perform stable combustion when said engine speed is lower than said predetermined value and that said engine performs stable combustion when said engine speed is higher than said predetermined value.

Claim 22

The system according to claim 16, further comprising: engine temperature sensing means for sensing an engine temperature and for producing a temperature signal; and engine speed sensing means for sensing an engine speed and for producing an engine speed signal; said determining means including first comparing means responsive to said temperature signal for comparing said engine temperature with a preset value and second comparing means responsive to said engine speed signal for comparing said engine speed with a first predetermined value when said engine temperature is lower than said preset value and with a second predetermined value when said engine temperature is higher than said preset value, and for determining that said engine does not perform stable combustion when said engine speed is lower than either one of said first and second predetermining values and that said engine performs stable combustion when said engine speed is higher than either one of said first and second predetermined values.

Claim 23

The system according to claim 18, wherein said determining means further comprises third comparing means for comparing said engine speed with a third predetermined value after it is once determined that said engine performs stable combustion, said third predetermined value being smaller than said second predetermined value, and for determining that said engine is back to unstable combustion when said engine speed becomes lower than said third predetermined value.

Claim 24

The system according to claim 4, wherein said deciding means includes a map indicating the variation of said fuel injection finishing time depending on the magnitude of said engine temperature, in which the lower said engine temperature is, the later said fuel injection finishing time is set.

Claim 25

The system according to claim 4, wherein said generating means comprises calculating means for calculating a fuel injection start timebased on said fuel injection finishing time and said set fuel injection pulse width.

Claim 26

The system according to claim 4, wherein said generating means is adapted to generate a first pulse at an intake stroke of said engine and a second pulse at an exhaust stroke of said engine, when said engine does not perform stable combustion at the engine start, a total width of said first and second pulses corresponding to said set fuel injection pulse width.

Claim 27

The system according to claim 22, further comprising: engine speed sensing means for sensing an engine speed and for producing engine speed signal; said determining means including comparing means responsive to said engine speed signal for comparing said engine speed with a predetermined value and for determining that said engine performs stable combustion when said engine speed is higher than said predetermined value and that said engine does not perform stable combustion when said engine speed is lower than said predetermined value.

Claim 28

The system according to claim 22, further comprising; engine speed sensing means for sensing an engine speed and for producing an engine speed signal; said determining means including first comparing means responsive to said temperature signal for comparing said engine temperature with a preset value and second comparing means responsive to said engine speed signal for comparing said engine speed with a first predetermined value when said engine temperature is lower than said preset value and with a second predetermined value when said engine temperature is higher than said preset value, said second predetermined value being smaller than said first predetermined value, and for determining that said engine performs stable combustion when said engine speed is higher than either one of said first and second predetermined values and that said engine does not perform stable combustion when said engine speed is lower than either one of said first and second predetermined values.

Claim 29

The system according to claim 24, wherein said determining means further includes third comparing means for comparing said engine speed with a third predetermined value after it is once determined that said engine performs stable combustion, said third predetermined value being smaller than said second predetermined value, and for determining that said engine is back to unstable combustion when said engine speed becomes lower than said third predetermined value.

Claim 32

A fuel injection control system for an internal combustion engine, having a fuel injector for injecting fuel into said engine in response to a fuel injection pulse, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; calculating means for calculating a width of the fuel injection pulse based on said operating conditions of said engine; and generating means responsive to a combustion state at the engine start determined by said determining means, for generating to said injector either a pulse with said calculated fuel injection width or a first pulse and second pulse at an intake stroke and exhaust stroke of said engine, respectively, the total width of said first pulse and second pulse corresponding to said calculated fuel injection pulse width.

Claim 33

A fuel injection control system for an internal combustion engine, having a fuel injector for injecting fuel into said engine in response to a fuel injection pulse, the system comprising: determining means for determining whether said engine performs stable combustion at the engine start depending on operating conditions of said engine; calculating means for calculating a width of the fuel injection pulse based on said operating conditions of said engine; and generating means responsive to a combustion state at the engine start determined by said determining means, for generating to said injector either a pulse with said calculated fuel injection width or a first pulse and second pulse at an intake stroke and exhaust stroke of said engine, respectively, the total width of said first pulse and second pulse corresponding to said calculated fuel injection pulse width.