Pressure-Dependent Suction Intake Valve for Jet Pump Vacuum Integrity
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Solution Overview
Problem
Existing suction jet pumps in fuel tanks suffer from vacuum loss and leak-tightness issues due to the use of non-return valves, which are inefficient and prone to fouling, especially when opening and closing to manage the fluid connection between the suction jet pump and the vapor bubble extraction vessel.
Innovation Solution
A pressure-dependent device with a valve body and spring element that opens and closes the suction intake based on feed line pressure, minimizing vacuum loss and ensuring fluid-tight sealing, featuring a valve body with an effective area exposed to feed pressure and a spring element opposing this pressure, with optional sealing elements and a nozzle for enhanced efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-return valve is used between the suction jet pump and the vapor bubble extraction vessel, then fuel backflow is prevented, but vacuum loss occurs due to valve opening
Solution Approach 1:
The invention extracts the non-return valve function from the suction line by placing it in the feed line instead. This allows the suction intake to remain open during pump operation without causing fuel backflow, as the check valve now protects the suction side indirectly through feed line control.
Solution Approach 2:
The invention introduces a mediator mechanism (check valve in feed line combined with pressure-dependent suction intake control) that indirectly achieves backflow prevention without directly blocking the suction path, thereby maintaining vacuum integrity while preventing fuel return.
2Loss of energy
If the closing force of the non-return valve is limited, then vacuum loss is reduced, but leak-tightness deteriorates
Solution Approach 1:
The invention removes the conflicting requirements by extracting the check valve from the suction path where it caused both vacuum loss and sealing issues. The new configuration places the check valve in the feed line, eliminating the trade-off between opening force and seal integrity.
Solution Approach 2:
Instead of controlling valve opening through suction pressure (which caused the contradiction), the invention inverts the control mechanism by using feed line pressure to actuate the suction intake, allowing independent optimization of both vacuum maintenance and sealing force.
3Productivity
If the suction intake remains open during pump operation, then suction efficiency is improved, but fuel can enter the vapor bubble extraction vessel when pump is off
Solution Approach 1:
The invention makes the suction intake dynamically controllable through feed line pressure actuation. The intake opens automatically when pump pressure builds up (improving efficiency) and closes when pressure drops (preventing fuel entry), creating a responsive system that adapts to operational states.
Solution Approach 2:
The system uses feed line pressure as feedback to automatically control suction intake opening. The pressure-dependent actuation creates a closed-loop control where the pump's own operating pressure regulates the intake state, ensuring efficiency during operation and containment at rest.
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 device effectively maintains low pressure loss between the suction jet pump and the separating device, enhancing the suction jet pump's efficiency and leak-tightness, while allowing for adjustable opening forces and optimal nozzle positioning for maximum suction effect.
Implementation Method 1
a spring element, arranged between the feed line and the valve body, for applying a force in opposition to the feed pressure inside the feed line
Implementation Method 2
The suction jet pumps generally used in motor vehicles nowadays generate a vacuum of 100 mbar, for example. The suction jet pump comprises a feed line (12), an outlet line (13) and the suction intake (10)
Implementation Method 3
a valve body (15), displaceably arranged inside the feed line (12) in the delivery direction (14) of the suction jet pump and having an effective area (16) exposed to the feed pressure of the suction jet pump
Data Source
AI summary
The invention relates to a device (6) for pressure-dependent opening of a suction intake (10), comprising a suction jet pump (11), comprising a feed line (12), an outlet line (13) and the suction intake (10); a valve body (15), displaceably arranged inside the feed line (12) in the delivery direction (14) of the suction jet pump (11) and having an effective area (16) exposed to the feed pressure of the suction jet pump (11); and a spring element (17), arranged between the feed line (12) and the valve body (15), for applying a force in opposition to the feed pressure inside the feed line (12); wherein the effective area (16) of the valve body (15), and the spring element (17) are designed so that the valve body (15) closes the suction intake (10) so that it is fluid-tight below a predefined pressure inside the feed line (12) and opens said intake when the predefined pressure inside the feed line (12) is exceeded. The invention further relates to a fuel tank, comprising a device (6) for pressure-dependent opening of a suction intake (10).