Evaporative Leak Module with Three-Position Proportional Valve
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Solution Overview
Problem
Existing evaporative emissions systems face challenges in efficiently detecting leaks using conventional two-way and three-way valves, which lack the flexibility to accommodate different diagnostic requirements and pressure modes, leading to inefficiencies in leak detection.
Innovation Solution
A three-position proportional solenoid valve with a longitudinally movable seal that operates in three positions to control fluid flow between a charcoal canister, pump, and atmospheric ports, allowing for precise pressure control and leak detection through distinct operational states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional two-way or three-way valves are used in the LDM, then the device complexity is reduced, but the adaptability for different diagnostic requirements and pressure modes is insufficient
Solution Approach 1:
The patent employs a proportional solenoid valve with a movable seal that can dynamically transition between three distinct positions (first position connecting charcoal canister to atmosphere, second position connecting charcoal canister to pump, third position blocking charcoal canister port) rather than using fixed conventional valves. This dynamic positioning capability enables the system to adapt to different diagnostic requirements and pressure modes while maintaining a relatively compact device structure.
2Measurement precision
If a proportional solenoid valve with three positions is used, then the leak detection accuracy and efficiency are improved, but the device complexity increases
Solution Approach 1:
The proportional solenoid valve is segmented into three distinct operational positions, each serving a specific function in the leak detection process. The seal divides the valve interior into separate flow paths, allowing precise control over fluid communication between ports. This segmentation enables accurate leak detection by creating distinct test conditions while keeping the overall valve structure integrated and manageable.
3Adaptability or versatility
If the seal moves between three positions to control fluid flow, then the flexibility for pressure modes is enhanced, but the manufacturing precision requirements increase
Solution Approach 1:
The movable seal acts as an intermediary element within the proportional solenoid valve, mediating the fluid flow between different ports based on the coil's energization state. The seal's movement between three positions creates distinct flow configurations that enable flexible pressure modes for leak detection. This intermediary mechanism allows the system to achieve multiple operational states while maintaining manageable manufacturing tolerances through the integrated valve design.
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
Enhances leak detection accuracy and efficiency by enabling flexible pressure modes and diagnostic states, ensuring reliable leak detection and system integrity verification.
Implementation Method 1
A rod is disposed in a coil and has a seal. The rod is configured to move longitudinally between first, second and third positions.
Implementation Method 2
The coil is configured to operate with a duty cycle in a range of 80%-100% in the second position, and the coil is configured to operate with the duty cycle in a range of 40%-60% in the third position.
Implementation Method 3
A spring is arranged within the first core and is operatively connected to the end. The spring is configured to bias the rod to the first position with the coil de-energized.
Data Source
AI summary
A leak detection module (LDM) includes a three-position proportional solenoid valve having a charcoal canister port fluidly connected to a charcoal canister connection, a pump port fluidly connected to a first port of a pump, and an atmospheric port fluidly connected to a second port of a pump. The atmospheric port is fluidly connected to atmosphere. A longitudinally movable rod has a seal with first, second and third positions. The seal obstructs the pump port and fluidly connects the charcoal canister port and the atmospheric port in the first position, obstructs the atmospheric portion and fluidly connects the charcoal canister port and the pump port in the second position, and obstructs the charcoal canister port in the third position which fluidly blocks the pump port from the atmospheric port and fluidly separates the first and second ports with the seal.