Fuel Tank Pressure Sensor Malfunction Detection via Atmospheric Venting
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Solution Overview
Problem
Existing pressure sensor malfunction determination devices for fuel tanks require additional pressure sensors, increasing component count and cost, whereas the goal is to detect malfunctions without additional sensors.
Innovation Solution
A pressure sensor malfunction determination device that uses the fuel tank pressure sensor to detect predetermined pressure states and performs valve-opening control on the tank on-off solenoid valve to determine if the sensor output corresponds to atmospheric pressure, allowing for malfunction detection without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional pressure sensors are installed to determine malfunction, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The existing fuel tank pressure sensor is made to serve dual functions: monitoring fuel tank pressure during normal operation and detecting sensor malfunction by comparing readings during controlled atmospheric pressure conditions. This eliminates the need for separate malfunction detection sensors.
Solution Approach 2:
The system uses its own existing pressure sensor to detect its own malfunction by creating a self-test condition where the sensor reading is compared against a known reference (atmospheric pressure) during a controlled state, allowing the sensor to verify its own functionality without external assistance.
2Object-affected harmful factors
If the fuel tank is sealed to prevent evaporation leakage, then environmental protection is improved, but pressure control difficulty increases
Solution Approach 1:
The sealed fuel tank system incorporates a dynamically controllable valve that can switch between closed (sealed) and open (ventilated) states. This dynamic element allows the system to maintain sealing during normal operation while providing a controlled pathway for pressure equalization when needed, managing pressure without requiring complex active control mechanisms.
3Reliability
If the tank on-off solenoid valve is opened to equalize pressure, then pressure control is improved, but fuel feeding time increases
Solution Approach 1:
The system performs preliminary pressure equalization by opening the tank on-off solenoid valve before the fuel feeding operation begins. This ensures that the fuel tank pressure is already equalized with atmospheric pressure when fuel feeding starts, eliminating delays during the actual fuel transfer operation.
Solution Approach 2:
The tank on-off solenoid valve is opened periodically or in discrete steps during the fuel feeding process to maintain pressure equalization. This periodic ventilation allows pressure to be equalized in controlled intervals rather than requiring continuous valve opening, minimizing the impact on fuel feeding time while ensuring pressure control is maintained.
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
Accurately detects pressure sensor malfunctions in both positive and negative pressure states, enabling fuel feeding only when the sensor output matches atmospheric pressure, thus eliminating the need for extra sensors and reducing costs.
Implementation Method 1
The canister is configured to absorb an evaporated fuel gas in the fuel tank
Implementation Method 2
a fuel tank pressure sensor configured to detect a pressure in the fuel tank
Data Source
AI summary
A pressure sensor malfunction determination device for a fuel tank includes a fuel tank that stores fuel, a canister that absorbs an evaporated fuel gas and includes a drain port opened to atmosphere, an evaporation path communicating with the canister and fuel tank, a purge gas path communicating with an engine inlet system and the canister, a pressure sensor that detects a pressure, a solenoid valve that opens/closes the evaporation path, and a control unit that controls an opening/closing state of the solenoid valve. When the fuel tank pressure is one of predetermined positive and negative pressure states, the control unit performs valve-opening control on the solenoid valve. The control unit includes a pressure sensor malfunction determination unit that, when an output value of the pressure sensor detected under an atmospheric pressure condition corresponds to a pressure other than the atmospheric pressure, determines that the pressure sensor is malfunctioning.