Engine Control Device Cylinder Knock Timing Variation
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Solution Overview
Problem
Existing engine control systems face challenges in managing variation in ignition timing across multiple cylinders, leading to reduced output and torque variation, while attempting to suppress knocking, as they cannot effectively adjust fuel injection ratios between direct and port injection valves to account for individual cylinder conditions.
Innovation Solution
An engine control device with a ratio determination unit, knock detection unit, and ignition timing adjustment unit that dynamically adjusts the fuel injection ratio between direct and port injection valves to maintain ignition timing variation within a predetermined range, using information from knock detection and operating conditions to optimize fuel delivery and ignition timing for each cylinder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the ignition timing is delayed (retarded) for the cylinder where knocking occurs, then the occurrence of knocking is suppressed, but variation in torque is caused and deterioration of driveability and engine noise is caused
Solution Approach 1:
The patent applies local quality by adjusting the fuel injection ratio specifically for cylinders experiencing knocking, rather than uniformly across all cylinders. The control device identifies individual cylinders with knocking issues and modifies their fuel injection characteristics (increasing port injection ratio) to suppress knocking locally, while maintaining optimal ignition timing for other cylinders, thus avoiding overall torque variation and driveability deterioration.
Solution Approach 2:
The patent changes the fuel injection parameters (ratio between direct injection and port injection) as a control variable to suppress knocking. Instead of changing ignition timing directly, the system adjusts the fuel injection ratio parameter, which indirectly affects combustion characteristics and suppresses knocking while preserving torque consistency across cylinders.
2Object-affected harmful factors
If the ignition timing of all cylinders is set to coincide with the ignition timing of the cylinder where the largest retard quantity is applied, then knocking suppression is achieved, but reduction in output for high-load region is caused
Solution Approach 1:
The patent applies local quality by allowing different ignition timing settings for different cylinders based on their individual knocking characteristics. Only cylinders experiencing knocking receive timing retardation through fuel injection ratio adjustment, while other cylinders maintain their optimal ignition timing for maximum power output, thus avoiding overall output reduction.
Solution Approach 2:
The patent implements dynamic control by continuously monitoring knocking conditions and adjusting fuel injection ratios in real-time. The system dynamically adapts ignition timing and fuel injection parameters based on actual knocking detection, allowing optimal power output when knocking is absent and targeted suppression when knocking occurs, rather than using a static retarded timing for all conditions.
3Object-affected harmful factors
If the ratio adjustment between direct injection and port injection is performed without exception, then knocking suppression is achieved, but it is not possible to correspond to variation in combustion state or variation in knocking occurrence for respective cylinders
Solution Approach 1:
The patent applies local quality by implementing cylinder-specific fuel injection ratio control based on individual knocking detection. Each cylinder's fuel injection ratio is independently adjusted according to its own combustion characteristics and knocking tendency, enabling the system to respond to variations in combustion state and knocking occurrence across different cylinders rather than applying a uniform adjustment to all.
Solution Approach 2:
The patent segments the fuel injection control into individual cylinder channels, with separate control logic for each cylinder based on its knocking detection results. This segmentation allows the system to tailor fuel injection ratios to specific cylinder conditions, improving adaptability to combustion variations and knocking patterns across the engine's multiple cylinders.
Data Source
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AI summary
An engine control device includes a plurality of cylinders, a direct injection valve that directly injects fuel into the cylinders, a port injection valve that injects fuel into an intake port, a ratio determination unit that determines a ratio between a fuel injection quantity by the direct injection valve and a fuel injection quantity by the port injection valve, for respective cylinders, a knock detection unit that detects knocking that occurs in the respective cylinders, and an ignition timing adjustment unit that sets ignition timing of the respective cylinders based on information on occurrence of the knocking by the knock detection unit. The ratio determination unit adjusts, for the respective cylinders, a ratio of the injection quantity between the fuel injection by the direct injection valve and the fuel injection by the port injection valve so that variation in the ignition timing among the cylinders which is determined by the ignition timing adjustment unit falls within a predetermined range.