Variable Valve Opening Control for Smooth Refueling
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Solution Overview
Problem
The existing refueling control systems for internal combustion engines face difficulties in smooth refueling when the opening speed of the shut-off valve is low, leading to increased pressure in the fuel tank and hindered fuel flow due to insufficient valve opening, resulting in inefficient refueling.
Innovation Solution
The system includes an electronic control unit that sets a target opening degree for the shut-off valve based on its opening speed, ensuring the valve is opened to a greater extent when the speed is low and closed when excessive, thereby facilitating smooth refueling regardless of the opening speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the shut-off valve opening speed is low, then the valve can be controlled precisely, but the valve opening degree is insufficient leading to pressure buildup and poor refueling
Solution Approach 1:
The patent applies dynamics by making the target opening degree variable rather than fixed. The control unit adjusts the target opening degree based on the detected opening speed of the shut-off valve. When opening speed is low, a larger target opening degree is set to ensure sufficient gas flow; when opening speed is high, a smaller target opening degree is set to prevent excessive pressure drop. This dynamic adjustment resolves the contradiction between precise control and refueling efficiency.
Solution Approach 2:
The patent changes the parameter of target opening degree based on the opening speed condition. By detecting the opening speed and selecting different target opening degree values from a map or table, the system adapts to different valve performance conditions. This parameter change strategy ensures that the valve opening is always appropriate for the current speed condition, preventing both insufficient opening (causing pressure buildup) and excessive opening (causing pressure drop).
2Speed
If the shut-off valve opens too quickly, then refueling can start faster, but the pressure in the fuel tank drops excessively preventing smooth refueling
Solution Approach 1:
The patent changes the target opening degree parameter based on opening speed to prevent excessive pressure drop. When the opening speed is high, the control unit selects a smaller target opening degree from the pre-stored map, which limits the maximum opening extent and prevents the pressure from dropping too much. This ensures refueling smoothness while still allowing fast opening when appropriate.
Solution Approach 2:
The patent uses feedback by detecting the actual opening speed of the shut-off valve and using this information to determine the appropriate target opening degree. The control unit continuously monitors the opening speed and adjusts the target opening degree accordingly, creating a closed-loop control system that maintains refueling reliability regardless of valve speed variations.
3Device complexity
If a fixed target opening degree is used, then the control system is simple, but it cannot adapt to different opening speeds causing refueling problems
Solution Approach 1:
The patent applies preliminary action by pre-storing a map or table of target opening degree values corresponding to different opening speed conditions. Instead of using complex real-time calculations, the control unit simply looks up the appropriate target opening degree from the pre-prepared data based on the detected opening speed. This approach provides adaptability to different opening speeds while keeping the control system relatively simple.
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 approach ensures smooth refueling operations by adjusting the shut-off valve's opening degree according to its speed, preventing pressure buildup and ensuring efficient fuel flow into the tank, regardless of whether the opening speed is high or low.
Implementation Method 1
a shut-off valve (24) disposed in the vapor passage (16), the shut-off valve (24) being configured to be driven by a step motor (24m)
Implementation Method 2
a fuel filler lid (29) configured to be opened and closed by an actuator (30)
Implementation Method 3
the electronic control unit (40) is configured to set the set opening degree such that the set opening degree when an opening speed of the shut-off valve (24) is low is greater than the set opening degree when the opening speed of the shut-off valve (24) is high
Data Source
AI summary
A refueling control system for an internal combustion engine includes a fuel tank; a vapor pipe; a step motor-driven shut-off valve; a fuel filler lid; and an electronic control unit configured to, when the fuel filler lid is to be opened, i) drive the shut-off valve such that the shut-off valve is opened, ii) close the fuel filler lid when an opening degree of the shut-off valve is less than a set opening degree, and iii) open the fuel filler lid when the opening degree of the shut-off valve is greater than or equal to the set opening degree. The electronic control unit sets the set opening degree such that the set opening degree when an opening speed of the shut-off valve is low is greater than the set opening degree when the opening speed of the shut-off valve is high.