Fuel Tank Vent Valve Control to Prevent Overfill and Canister Damage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing evaporated fuel treatment apparatuses often result in additional fuel supply beyond the fuel tank capacity, leading to fuel overflow and canister deterioration, as the full-tank control valve is opened and closed, causing internal pressure fluctuations.
Innovation Solution
An evaporated fuel treatment apparatus with an electrically-operated valve and a control unit that monitors fuel volume and pressure to prevent excessive fuel supply by fully closing the valve when predetermined conditions are met, ensuring the fuel level in the supply pipe is maintained, thus preventing additional fuel from exceeding the tank capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the full-tank control valve is used to control fuel supply, then the fuel tank can be filled to capacity, but additional fuel supply beyond capacity occurs due to valve opening/closing delays
Solution Approach 1:
The patent divides the fuel supply control function into two independent parts: the full-tank control valve (mechanical float-type) for basic on/off control, and a newly added electronically-controlled valve for precise timing control. This segmentation allows each valve to specialize - the mechanical valve handles bulk flow control while the electronic valve provides precise shut-off timing based on sensor feedback, eliminating the reliability issue of manual valve timing delays
Solution Approach 2:
The patent introduces a fuel level sensor that provides real-time feedback on the fuel level in the supply pipe. This feedback signal is sent to the control unit, which automatically controls the electronic valve to close at the precise moment when the fuel level reaches the predetermined position. This closed-loop feedback system eliminates the timing delays and inaccuracies inherent in mechanical float-based control alone
2Object-affected harmful factors
If the full-tank control valve closes to stop fuel supply, then fuel overflow is prevented, but fuel may still infiltrate the canister due to pressure fluctuations
Solution Approach 1:
The patent uses the fuel level sensor to detect the fuel level in advance before it reaches the canister inlet. When the sensor detects that the fuel level is approaching the critical position, it sends a signal to the control unit, which then closes the electronic valve in advance. This preliminary action prevents fuel from ever reaching the canister, eliminating the risk of canister deterioration from fuel infiltration while still allowing the full-tank control valve to perform its overflow prevention function
Solution Approach 2:
The electronic valve acts as an intermediary between the fuel supply system and the canister. It provides an additional control layer that can shut off fuel flow before it reaches the canister, independent of the mechanical full-tank control valve. This intermediary valve ensures that even if pressure fluctuations occur or the mechanical valve responds slowly, fuel will not infiltrate the canister
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
The solution effectively prevents additional fuel supply beyond the fuel tank capacity, maintaining the fuel level and internal pressure within safe limits, thereby protecting the canister and ensuring efficient fuel treatment.
Implementation Method 1
a pressure sensor for detecting an internal pressure of the fuel tank
Implementation Method 2
a fuel volume measurement unit for measuring a fuel volume in the fuel tank
Implementation Method 3
an electrically-operated valve placed between the full-tank control valve and the atmosphere open port
Implementation Method 4
a canister for storing an evaporated fuel fed from the fuel tank through the vapor passage
Data Source
AI summary
An evaporated fuel treatment apparatus includes an electrically-operated valve disposed between a full tank control valve and an atmosphere open port and a control unit that controls the electrically-operated valve, and the control unit performs valve-closing control that fully closes the electrically-operated valve when a valve-closing condition is satisfied after the start of fuel supply, in which a value measured by a fuel volume measurement unit is equal to or greater than a first predetermined value determined in advance and a value detected by a pressure sensor is equal to or greater than a second predetermined value determined in advance.