Ignition Advance Control via Fuel Micro-Injection for Catalyst Priming
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Solution Overview
Problem
Internal combustion engines face challenges in maintaining combustion stability and meeting emission standards, particularly when catalysts are not activated at lower operating temperatures, requiring adjustments in ignition timing that impact engine performance and emissions.
Innovation Solution
A process for determining the ignition advance setpoint in internal combustion engines, which involves calculating a micro-injection yield and using it to adjust the ignition timing, thereby optimizing engine torque and efficiency while ensuring catalyst activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the ignition advance is delayed to prime the catalyst at lower operating temperatures, then the catalyst becomes activated and can treat pollutants effectively, but the combustion stability deteriorates and engine performance is reduced
Solution Approach 1:
The fuel injection is divided into two separate quantities: a main quantity injected at the conventional timing and an auxiliary quantity injected in micro-injection mode around the combustion Top Dead Center. This segmentation allows the main fuel quantity to maintain stable combustion while the auxiliary quantity provides additional calories to prime the catalyst, thereby resolving the contradiction between combustion stability and catalyst activation.
Solution Approach 2:
The auxiliary fuel quantity is injected in advance around the combustion Top Dead Center, before the main combustion event completes. This preliminary action ensures that the additional fuel is available to boost the exhaust temperature and activate the catalyst without disrupting the main combustion stability, as the auxiliary injection occurs after the ignition of the air/main fuel mixture.
2Temperature
If the ignition advance is delayed to add calories to the exhaust line, then the catalyst priming temperature is reached, but the engine torque and overall efficiency are reduced
Solution Approach 1:
By segmenting the fuel injection into main and auxiliary quantities with different timing, the patent achieves exhaust temperature increase through the auxiliary micro-injection without requiring a global delay of the ignition advance. The main fuel quantity maintains the optimal ignition timing for engine torque, while the auxiliary quantity adds the necessary calories to the exhaust line.
Solution Approach 2:
The auxiliary fuel injection creates a secondary combustion event that copies the energy release function but at a different timing (around TDC). This copied combustion event specifically targets exhaust temperature increase for catalyst priming, while the main combustion event maintains optimal ignition timing for engine power output.
3Object-generated harmful factors
If micro-injection is activated to improve combustion stability and catalyst priming, then pollutant treatment is enhanced, but the device complexity increases
Solution Approach 1:
The existing fuel injection system is made multi-functional by enabling it to operate in two modes: conventional injection for main fuel delivery and micro-injection for auxiliary fuel delivery. This universality allows the same injection hardware to perform both catalyst priming and normal fuel injection functions, avoiding the need for separate dedicated micro-injection hardware and thereby minimizing the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process allows for precise management of engine torque and improved combustion stability, optimizing engine performance and reducing pollutant emissions by ensuring effective catalyst operation across a range of temperatures.
Implementation Method 1
spark-ignition internal combustion engine
Implementation Method 2
injection of a quantity of auxiliary fuel, referred to as micro-injection, into the cylinder
Data Source
Figure 1~2
AI summary
The present invention relates to a method for determining an ignition-advance setpoint (CAA) for a controlled-ignition internal combustion engine, comprising the steps of determining a torque setpoint (Cc), an effective torque (Ce), a first ignition-advance efficiency (RAAsmi) which is a function of the torque setpoint (Cc) and of the effective torque (Ce), in the case of a mode in which fuel is injected without microinjection, and a status, activated or non-activated, of a fuel-injection mode for which some of this fuel is intended to be injected by microinjection (Smi), characterized in that it further comprises the steps of determining a microinjection efficiency (Rmi), of determining the efficiency of ignition advance with microinjection (RAAami), from the microinjection efficiency (Rmi) and from the first ignition-advance efficiency (RAAsmi), of determining and applying the ignition-advance setpoint (CAA) as a function of the previously determined efficiency of the ignition advance with microinjection (RAAami).