Fuel injection control method and fuel-injection control device

• US 7,273,038 B2
• Filed: 12/09/2003
• Issued: 09/25/2007
• Est. Priority Date: 12/10/2002
• Status: Expired due to Fees

• Current Assignee: Mikuni Corporation
• Original Assignee: Mikuni Corporation
• Inventors: Hayakawa, Kunihiko
• Primary Examiner(s): MOULIS, THOMAS N
• Application Number:
  US10/538,235
• Publication Number:
  US 20060137661A1
• Time in Patent Office: 1,386 Days
• Field of Search: 123/478, 123/479, 361/160, 361/187
• US Class Current: 123/478
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 2041/2065 the control being related to the coil temperature
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils

Abstract

In order to perform accurate fuel injection control in response to fuel injection requests from the engine side without being affected by variations in power supply voltage and in coil temperature of a fuel injection solenoid and by other external factors, driving of the fuel injection solenoid is controlled based on the actual current integral of the coil current flowing through the solenoid after starting driving the solenoid. More specifically, the present invention provides a fuel injection control method having the steps of starting driving of a fuel injection solenoid, detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid, comparing the actual current integral with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount, and correcting the driving pulse width for the solenoid based on comparison between the actual current integral and the reference current integral, where the driving of the solenoid is controlled based on the corrected driving pulse width.

Claims

1. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

comparing the actual current integral with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount; and

correcting the driving pulse width for the solenoid based on comparison between the actual current integral and the reference current integral,

wherein the driving of the solenoid is controlled based on the driving pulse width corrected.

7. The fuel injection control method according to claim 1, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

2. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

comparing the actual current integral with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount; and

halting the driving of the solenoid at the time the actual current integral reaches the reference current integral.

15. The fuel injection control method according to claim 2, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

3. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

comparing the actual current integral with a target current integral beforehand set in relation to a required fuel injection amount; and

correcting a driving pulse width for the solenoid based on comparison between the actual current integral and the target current integral,

wherein the driving of the solenoid is controlled based on the driving pulse width corrected.

16. The fuel injection control method according to claim 3, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

4. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

comparing the actual current integral with a target current integral beforehand set in relation to a required fuel injection amount; and

halting the driving of the solenoid at the time the actual current integral reaches the target current integral.

17. The fuel injection control method according to claim 4, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

5. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

calculating an estimated fuel injection amount corresponding to the actual current integral;

comparing the estimated fuel injection amount with a required fuel injection amount; and

correcting a driving pulse width for the solenoid based on comparison between the estimated fuel injection amount and the required fuel injection amount,

wherein the driving of the solenoid is controlled based on the driving pulse width corrected.

18. The fuel injection control method according to claim 5, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

6. A fuel injection control method comprising the steps of:

starting driving of a fuel injection solenoid;

detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid;

calculating an estimated fuel injection amount corresponding to the actual current integral;

comparing the estimated fuel injection amount with a required fuel injection amount; and

halting the driving of the solenoid at the time the estimated fuel injection amount reaches the required fuel injection amount.

19. The fuel injection control method according to claim 6, further comprising the step of:

resetting the actual current integral every driving cycle of the fuel injection solenoid.

8. A fuel injection control apparatus comprising:

driving means for driving a fuel injection solenoid;

detecting means for detecting an actual current integral of a coil current flowing through the solenoid; and

control means for controlling driving of the solenoid based on the actual current integral, wherein the control means comprises;

comparing means for comparing the actual current integral obtained after starting driving of the solenoid detected in the detecting means with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount; and

correcting means for correcting the driving pulse width for the solenoid based on a result of comparison in the comparing means.

9. The fuel injection control apparatus according to claim 8, wherein the control means comprises comparing means for comparing the actual current integral obtained after starting driving of the solenoid detected in the detecting means with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount, and halts the driving of the solenoid by the driving means at the time the actual current integral reaches the reference current integral.

10. The fuel injection control apparatus according to claim 8, wherein the control means comprises:

comparing means for comparing the actual current integral obtained after starting driving of the solenoid detected in the detecting means with a target current integral beforehand set in relation to a required fuel injection amount; and

correcting means for correcting a driving pulse width for the solenoid based on comparison between the actual current integral and the target current integral.

11. The fuel injection control apparatus according to claim 8, wherein the control means comprises comparing means for comparing the actual current integral obtained after starting driving of the solenoid detected in the detecting means with a target current integral beforehand set in relation to a required fuel injection amount, and halts the driving of the solenoid by the driving means at the time the actual current integral reaches the target current integral.

12. The fuel injection control apparatus according to claim 8, wherein the control means comprising:

calculating means for calculating an estimated fuel injection amount corresponding to the actual current integral obtained after starting driving of the solenoid;

comparing means for comparing the estimated fuel injection amount with a required fuel injection amount; and

correcting means for correcting a driving pulse width for the solenoid based on comparison between the estimated fuel injection amount and the required fuel injection amount.

13. The fuel injection control apparatus according to claim 8, wherein the control means comprises:

calculating means for calculating an estimated fuel injection amount corresponding to the actual current integral obtained after starting driving of the solenoid; and

comparing means for comparing the estimated fuel injection amount with a required fuel injection amount, and

halts the driving of the solenoid by the driving means at the time the estimated fuel injection amount reaches the required fuel injection amount.

14. The fuel injection control apparatus according to claim 8, wherein the detecting means for detecting the actual current integral is an analog detecting circuit that detects a cumulative current value of the coil current or a digital detecting circuit that measures a value of the coil current at predetermined intervals to calculate.