Fuel Injection Control Device Cylinder-Specific Pulse Width Correction
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Solution Overview
Problem
Fuel injection valves in internal combustion engines exhibit variations in injection performance, leading to differences in air-fuel ratios and combustion performance among cylinders, especially during split injection, where the number of injections can differ due to varying pulse widths.
Innovation Solution
A fuel injection control device and method that adjusts the pulse width for each cylinder based on specific correction values to maintain consistent air-fuel ratios and prevent variations in split numbers among cylinders by determining a basic pulse width, applying cylinder-specific corrections, and modifying the split number based on acceptance determinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pulse width correction is applied based on injection variations among fuel injection valves, then air-fuel ratio variations among cylinders are suppressed, but split numbers may differ among cylinders due to varying pulse widths
Solution Approach 1:
The patent applies dynamics by making the split number determination adaptive rather than fixed. The control device dynamically adjusts the determination reference value for split number acceptance based on the actual pulse widths after correction, allowing the split number assignment to respond to individual cylinder characteristics while maintaining overall consistency.
Solution Approach 2:
The patent changes the parameter used for split number determination from a fixed value to a dynamically adjusted reference value. By modifying the determination reference value based on corrected pulse widths, the system accommodates pulse width variations while ensuring consistent split numbers across cylinders.
2Manufacturing precision
If split injection is conducted with corrected pulse widths for each cylinder, then air-fuel ratio variations are reduced, but the complexity of the control system increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing determination reference values for split number acceptance before actual fuel injection control. This preliminary setup simplifies the real-time control process by having reference values ready for comparison, reducing the computational complexity during active operation.
Solution Approach 2:
The patent implements feedback by using the actual pulse widths after correction to adjust the split number determination reference values. This feedback mechanism allows the system to adapt to actual injection characteristics while maintaining a relatively simple control structure by adjusting parameters rather than complex control logic.
3Reliability
If the minimum pulse width is strictly enforced for each injection, then reliable fuel injection is ensured, but the flexibility in setting split numbers is reduced
Solution Approach 1:
The patent changes the minimum pulse width parameter from a fixed strict limit to a flexible reference value that can be adjusted based on cylinder-specific characteristics. By modifying the determination reference value for split number acceptance, the system maintains injection reliability while allowing greater flexibility in split number assignment.
Solution Approach 2:
The patent applies dynamics by making the pulse width constraint adaptive rather than rigid. The control device dynamically determines acceptable split numbers based on actual pulse widths and adjusted reference values, allowing the system to maintain reliability while adapting to different operating conditions and cylinder characteristics.
Data Source
AI summary
A fuel injection control device and a fuel injection control method for an internal combustion engine according to the present invention correct a basic pulse width by a cylinder-specific correction value that is based on injection variations among fuel injection valves to specify a cylinder-specific pulse width, determine whether or not a split number is acceptable based on a minimum pulse width and a pulse width per one injection calculated from the cylinder-specific pulse width and the split number to modify the split number based on a result of the acceptance determination, modify an acceptance determination reference value which is used in the acceptance determination based on the correction value for each cylinder, and execute split injection based on the split number, the basic pulse width, and the correction value for each cylinder.