Fuel Injector Control Chamber Pressure Sensor
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Solution Overview
Problem
Fuel injectors experience wear-related drift in closing times due to series tolerances and component variations, leading to suboptimal engine operation and inconsistent fuel injection quantities.
Innovation Solution
A force or pressure sensor is integrated into the control chamber of the fuel injector to monitor pressure changes during nozzle needle operations, eliminating the need for precise stroke travel detection and allowing accurate determination of operating phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stroke travel detection is used to determine operating phases, then measurement precision can be improved, but device complexity and manufacturing cost increase significantly
Solution Approach 1:
The patent uses control chamber pressure as an intermediary parameter to indirectly determine operating phases. Instead of directly measuring stroke travel, the system measures pressure changes in the control chamber that occur during nozzle needle opening and closing, providing accurate operating phase detection with simpler hardware
Solution Approach 2:
The patent replaces mechanical stroke travel detection mechanisms with a pressure-based sensing system. By substituting mechanical measurement with pressure measurement, the system achieves comparable or superior measurement precision while reducing mechanical complexity and wear
2Ease of manufacture
If series tolerances and component variations are present, then manufacturing ease is improved, but reliability of closing times deteriorates
Solution Approach 1:
The patent implements feedback by continuously monitoring control chamber pressure and using this information to determine actual operating phases. This feedback mechanism compensates for wear and tolerance variations, allowing the system to adapt to changing conditions and maintain reliable operation despite manufacturing variations
Solution Approach 2:
The patent changes the monitoring parameter from mechanical position (stroke travel) to pressure parameter. This parameter change allows the system to account for wear and tolerance variations by measuring pressure changes that naturally occur during operation, thereby maintaining reliability without compromising manufacturing ease
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 solution enables precise monitoring of fuel injector operations, reduces wear-related issues, and allows for redundant pressure detection across multiple injectors, optimizing engine control and eliminating the need for separate high-pressure source monitoring systems.
Implementation Method 1
a force or pressure sensor arrangement (20) is provided in the low-pressure region of the fuel injector, which is coupled to the control chamber pressure
Implementation Method 2
The sleeve-shaped closing body interacts with a seat concentric with the mouth of the outlet duct and is connected to an armature which, for its part, interacts with an electromagnet arrangement coaxial with the guide rod. If the electromagnet arrangement is electrically energized, the armature, together with the sleeve-shaped closing body, is pulled in the direction of the electromagnet arrangement
Data Source
AI summary
The invention relates to a control chamber, the pressure of which determines the strokes or positions of a nozzle needle, and which is assigned to a force or pressure sensor in order to detect the progression of the control chamber pressure. Because the control chamber pressure significantly changes during the closing of the nozzle needle, the operating phases of the injector can be exactly determined from the sensor data and supplied to an engine controller.