Fuel Dosing Valve Pressure Oscillation Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel metering devices for internal combustion engine exhaust systems experience pressure fluctuations from the low-pressure fuel system, leading to chattering or buzzing operations in injection valves, which disrupt fuel injection and jet preparation, increasing complexity and reducing reliability.
Innovation Solution
A damping device is hydraulically connected to the fuel inlet to dampen pressure fluctuations, using a low-pressure system from the conventional injection system, eliminating the need for a separate pump and control system, and employing a pressure-controlled injection valve with a metering valve for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel is supplied from a separate pump and control system, then the injection valve can be reliably controlled, but the device complexity and cost increase
Solution Approach 1:
The patent merges the fuel supply function for the exhaust injection valve with the existing low-pressure injection system by integrating a metering valve into the common fuel rail. This eliminates the need for a separate pump and control system, reducing device complexity while maintaining reliable control through the shared fuel delivery infrastructure.
Solution Approach 2:
The low-pressure fuel system is designed to serve dual purposes: supplying fuel to the combustion chambers through the common rail and simultaneously supplying fuel to the exhaust injection valve. This multi-functional approach eliminates redundant components while ensuring reliable fuel delivery to both systems.
2Device complexity
If pressure fluctuations from the low-pressure system are allowed to pass to the injection valve, then the system remains simple, but the injection process is disrupted and jet preparation is impaired
Solution Approach 1:
The patent introduces a metering valve as an intermediary component between the low-pressure fuel system and the injection valve. This metering valve acts as a buffer that filters out pressure fluctuations and oscillations from the common rail, preventing them from reaching the injection valve and disrupting the injection process or jet preparation quality.
3Measurement precision
If a separate pump is used for exhaust fuel injection, then precise fuel metering is achieved, but the cost and system complexity increase
Solution Approach 1:
The patent enables the low-pressure fuel system to serve itself by using the existing common rail and fuel pressure to supply both the combustion chambers and the exhaust injection valve. The metering valve precisely controls the fuel quantity for exhaust injection without requiring external pumping, achieving precise fuel metering while eliminating the need for a separate pump 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
The damping device stabilizes the injection process, maintaining desired jet preparation and reducing the impact of pressure oscillations, enhancing the reliability and cost-effectiveness of the exhaust gas aftertreatment system by integrating with the existing low-pressure fuel system.
Implementation Method 1
The device has a damping device hydraulically connected to the fuel inlet for damping pressure oscillations
Implementation Method 2
When liquid fuel is injected into the comparatively hot exhaust gas, the fuel evaporates and extracts heat from the exhaust gas
Implementation Method 3
If the fuel is injected into an oxidizing exhaust gas atmosphere, chemical reactions can be triggered. So e.g. B. exothermic chemical reactions for heating exhaust gas aftertreatment components
Implementation Method 4
an injection valve arranged in the exhaust system, which is also cooled by a flowing coolant when it is closed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Proposed is a device (10; 40; 50; 60) for dosing fuel into the exhaust system (12) of an internal combustion engine, having an injection valve (14; 42) which is arranged in the exhaust system (12) and which is cooled by means of a flowing cooling liquid even in the closed state and which is supplied with fuel via a fuel inflow (16), from which a first partial flow (j_e) is injected into the exhaust gas and from which a second partial flow (j_r) is recirculated via a fuel collecting return line (32) into a fuel storage tank. The device is characterized in that the fuel inflow (16) is fed from a low-pressure system (18) of an injection system which serves for dosing fuel for combustions which take place in a combustion chamber of the internal combustion engine, and in that the device (10; 40; 50; 60) has a damping device (20), which is hydraulically connected to the fuel inflow (16), for damping pressure oscillations.