Evaporated Fuel Processing Device Leak Diagnosis
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Solution Overview
Problem
Existing evaporated fuel processing devices for internal combustion engines require multiple pressure sensors to diagnose leaks, increasing component count and complexity, whereas a single differential pressure sensor can effectively detect system pressure differences between the fuel tank and canister to diagnose leaks, reducing the number of components needed.
Innovation Solution
An evaporated fuel processing device incorporating a differential pressure sensor to detect system differential pressure between the fuel tank and canister, along with a pump and valves, allows for leak diagnosis by controlling the system pressure and using software to interpret sensor data for leak detection in both the canister and tank sides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple pressure sensors are used to diagnose leaks, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple pressure sensing functions into a single differential pressure sensor that measures the pressure difference between the fuel tank and canister simultaneously. This merging approach maintains leak detection capability while reducing the number of components from multiple pressure sensors to one differential pressure sensor.
Solution Approach 2:
The differential pressure sensor serves multiple diagnostic functions: it detects leaks in both the fuel tank and canister, monitors system pressure differences, and enables comprehensive evaporated fuel system diagnosis. This multi-functionality replaces what would traditionally require multiple dedicated sensors for each diagnostic purpose.
2Reliability
If multiple pressure sensors are installed, then reliability of leak diagnosis is improved, but manufacturing cost increases
Solution Approach 1:
By merging multiple pressure sensing roles into a single differential pressure sensor, the patent reduces component count and assembly complexity, directly lowering manufacturing costs while maintaining diagnostic reliability through the sensor's ability to monitor pressure differences across the entire evaporated fuel system.
Solution Approach 2:
The differential pressure sensor provides universal monitoring capability for the entire evaporated fuel system, enabling reliable leak detection in both the fuel tank and canister with a single component, thereby reducing manufacturing expenses associated with multiple specialized sensors and their installation.
3Device complexity
If a single differential pressure sensor is used, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The differential pressure sensor acts as an intermediary measurement device that indirectly detects leaks by measuring the pressure difference between the fuel tank and canister. This indirect measurement approach maintains diagnostic accuracy while using a single sensor, as the pressure differential provides sufficient information to identify leaks in either component.
Solution Approach 2:
The patent replaces the mechanical approach of using multiple independent pressure sensors with a differential pressure measurement system that uses a single sensor to measure pressure differences. This substitution maintains measurement capability while simplifying the overall sensing system.
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 configuration reduces the number of components, enables efficient leak diagnosis with a single sensor, and quickly determines the presence of leaks, thereby improving diagnostic efficiency and reducing fuel consumption by maintaining atmospheric pressure in the fuel tank.
Implementation Method 1
a differential pressure sensor configured to detect a system differential pressure of a detection target system including the canister and the fuel tank, the system differential pressure being a pressure difference between a pressure on the canister side of the tank sealing valve and a pressure on the fuel tank side of the tank sealing valve
Implementation Method 2
a canister that adsorbs the evaporated fuel generated in the fuel tank
Implementation Method 3
a pump that pressurizes or depressurizes the detection target system
Data Source
AI summary
An evaporated fuel processing device is configured to collect evaporated fuel from a fuel tank of an internal combustion engine. The evaporated fuel processing device includes the fuel tank, a canister, a tank sealing valve, a switching valve, and a differential pressure sensor. The fuel tank stores fuel for the internal combustion engine. The canister adsorbs evaporated fuel generated in the fuel tank. The switching valve switches between allowing and blocking off communication between the canister and open air. The differential pressure sensor detects a system differential pressure between the pressure on the canister side of the tank sealing valve and the pressure on the fuel tank side of the tank sealing valve in the detection target system.