Bidirectional Pump for Fuel Tank Venting and Leak Diagnosis
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Solution Overview
Problem
Conventional fuel tank ventilation systems in motor vehicles, particularly in turbo engines and hybrid vehicles, face challenges in adequately regenerating active carbon filters due to low intake underpressure, and there is a need for a cost-effective solution that also enables on-board fuel tank leak diagnosis without additional components.
Innovation Solution
A venting system with a bidirectional conveying device or pump that can switch directions to regenerate the sorption filter by conveying fluids to the intake manifold and perform leak diagnosis by creating overpressure when switched towards the fuel tank, using a switchover valve and check valves to manage fluid flow and pressure effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fuel tank ventilation system using underpressure in the intake manifold is used, then the system is simple and cost-effective, but the active carbon filter is not adequately regenerated in turbo engines and hybrid vehicles
Solution Approach 1:
The bidirectional conveying device serves multiple functions: it acts as a purge pump for filter regeneration, a pressure source for leak diagnosis, and a flow control element. By integrating these functions into a single device that can operate in two directions, the system achieves effective filter regeneration and leak detection capability without proportionally increasing system complexity
Solution Approach 2:
The conveying device is designed to be bidirectional and switchable, allowing it to dynamically change its operation mode between regeneration (conveying toward engine) and leak diagnosis (creating overpressure toward fuel tank). This dynamic capability enables a single device to adapt to different operational requirements that previously would have required separate components
2Reliability
If additional components are added to enable on-board fuel tank leak diagnosis, then leak detection capability is improved, but manufacturing cost and system complexity increase
Solution Approach 1:
The bidirectional conveying device is designed to perform both filter regeneration and leak diagnosis functions. During leak diagnosis mode, the device creates overpressure in the fuel tank by reversing its flow direction, enabling detection of leaks without requiring separate diagnostic equipment. This multi-functionality eliminates the need for additional dedicated leak detection components
Solution Approach 2:
The venting system performs its own leak diagnosis using its own conveying device and control logic. The system uses its bidirectional conveying capability to create test pressures and monitor flow characteristics to detect leaks, eliminating the need for external or additional specialized diagnostic components that would increase manufacturing cost
3Adaptability or versatility
If a bidirectional conveying device is used for both filter regeneration and leak diagnosis, then system versatility is improved, but device complexity increases
Solution Approach 1:
The bidirectional conveying device integrates multiple functions (purge pump, pressure source, flow control) into a single unit. By designing the device to operate in two directions with switchable flow paths using valves, the system achieves high versatility without proportionally increasing complexity compared to having separate dedicated components for each function
Solution Approach 2:
The patent combines the purge pump function and leak diagnosis pressure source function into a single bidirectional conveying device. By merging these functions and using valve control to direct flow in different directions, the system achieves versatility while managing complexity through integration rather than multiplication of components
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
Ensures effective regeneration of the sorption filter and facilitates on-board fuel tank leak diagnosis, reducing the need for additional components and minimizing power consumption, while being suitable for turbo engines with low intake underpressure.
Implementation Method 1
a sorption filter (14) for temporarily storing fuel evaporating from the fuel tank (12)
Implementation Method 2
the conveying device (24) is a bidirectional conveying device which is switchable in a first conveying direction in the direction of the internal combustion engine (22) for regenerating the sorption filter (14) and in a second conveying direction in the direction of the sorption filter (14) for carrying out a fuel tank leak diagnosis
Data Source
AI summary
In a venting system, in particular for a fuel tank of a motor vehicle, which has a sorption filter for temporarily storing fuel evaporating from the fuel tank and a fluid-conveying conveying device situated between the sorption filter and an air supply or an intake manifold of an internal combustion engine, according to the present system, the conveying device is a bidirectional conveying device which is switchable in a first conveying direction in the direction of the internal combustion engine for regenerating the sorption filter and in a second conveying direction in the direction of the sorption filter for carrying out a fuel tank leak diagnosis.