Purge Valve Opening Speed Control for Stable Air-Fuel Ratio
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Solution Overview
Problem
The existing valve speed type purge control systems for vehicles face challenges in stabilizing the air-fuel ratio and ensuring compliance with hydrocarbon emission regulations due to difficulties in reflecting hydrocarbon concentration models and external conditions, leading to unstable air-fuel ratio behavior and limited purge rates.
Innovation Solution
A method and system that dualize the opening speed of the purge valve based on an ambient air temperature-based gas concentration model, using low and high concentration rate coefficients, coolant temperature rate coefficients, and ambient air temperature rate coefficients to control the purge valve opening speed, thereby stabilizing the air-fuel ratio and securing a suitable purge rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed valve opening speed is applied to the purge control, then the purge rate is secured, but the air-fuel ratio becomes unstable when hydrocarbon concentration is high
Solution Approach 1:
The patent applies dynamics by making the valve opening speed variable rather than fixed. The control unit adjusts the purge valve opening speed dynamically based on the hydrocarbon concentration detected by the concentration sensor. When hydrocarbon concentration is high, the opening speed is reduced to prevent air-fuel ratio instability; when concentration is low, the opening speed increases to maintain adequate purge rate. This dynamic adaptation resolves the contradiction between maintaining stable air-fuel ratio and ensuring sufficient purge rate under varying conditions.
Solution Approach 2:
The patent changes the operational parameter of valve opening speed based on hydrocarbon concentration levels. The control unit receives concentration information from the sensor and modifies the valve opening speed parameter accordingly. This parameter change allows the system to adapt to different purge conditions, preventing air-fuel ratio instability during high concentration purges while maintaining effective purge rates during low concentration conditions.
2Reliability
If the purge valve opening speed is reduced to stabilize air-fuel ratio, then air-fuel ratio stability improves, but the purge rate becomes insufficient
Solution Approach 1:
The system dynamically adjusts the valve opening speed based on real-time hydrocarbon concentration measurements. When the concentration sensor detects low hydrocarbon levels, the control unit increases the valve opening speed to maintain adequate purge rate. When high concentration is detected, the opening speed is reduced to stabilize air-fuel ratio. This dynamic response ensures that the system achieves both sufficient purge rate and air-fuel ratio stability under different operating conditions.
Solution Approach 2:
The patent implements feedback control by using the hydrocarbon concentration sensor to monitor purge gas composition and adjusting the valve opening speed accordingly. The control unit receives concentration feedback and modifies the valve operation to achieve both adequate purge rate and stable air-fuel ratio. This closed-loop feedback mechanism allows the system to self-regulate and balance the conflicting requirements of purge rate and air-fuel ratio stability.
3Device complexity
If existing purge control methods are used, then the system structure remains simple, but the system cannot comply with hydrocarbon emission regulations due to unstable air-fuel ratio behavior
Solution Approach 1:
The patent introduces a concentration sensor and control unit that form a feedback control loop. The sensor detects hydrocarbon concentration in the purge gas and provides feedback to the control unit, which adjusts the purge valve opening speed to maintain stable air-fuel ratio behavior. This feedback mechanism ensures compliance with hydrocarbon emission regulations by preventing air-fuel ratio instability, while adding only moderate complexity to the existing purge control system.
Solution Approach 2:
The patent replaces simple mechanical purge control with an electronically controlled system that uses sensor feedback and electronic control units to regulate valve opening speed. This substitution of mechanical control with electronic control and feedback mechanisms enables precise regulation of purge parameters to ensure emission compliance, while the added complexity remains manageable through modern electronic control architecture.
Data Source
AI summary
A method controls an opening speed of a purge valve according to the purge gas concentration implemented by an active purge system (APS). A purge controller varies, when a valve opening speed of a purge control solenoid valve (PCSV) is controlled, the valve opening speed of the PCSV using any one among a low concentration rate coefficient, a high concentration rate coefficient, a coolant temperature rate coefficient, and an ambient air temperature rate coefficient, and performs the purge control using a difference between the valve opening speeds, and thus dualizes the valve opening speed of the PCSV according to a hydrocarbon (HC) concentration, thereby stably controlling the air-fuel ratio, and simultaneously, securing the purge rate and relatively stably control an air-fuel ratio in a state of high concentration purge execution.