Fuel Injector Valve Force Transmission Element
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Solution Overview
Problem
Piezo-controlled servo valves in fuel injection systems face challenges in detecting the end of injection due to parasitic decoupling from the force flow line, leading to a less robust and more fault-prone detection method compared to electromagnetically actuated valves, with a limited functional range for fuel pressure-load levels.
Innovation Solution
A fuel injection valve configuration that uses a force transmission element, such as a rigid or fuel-resistant elastic plastic pin, to transmit pressure-induced forces to a piezoelectric actuator via a mechanical or hydraulic transmission device, allowing for improved detection of valve chamber pressure and enhanced resolution in vibration detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezoelectric actuator is used in a servo valve for fuel injection, then the valve can be controlled with high precision, but the detection of the end of injection becomes less robust and more fault-prone due to parasitic decoupling from the force flow line
Solution Approach 1:
A force transmission element is introduced as an intermediary component that directly transmits the force from the piezoelectric actuator. This element serves as a mechanical bridge that maintains the connection to the force flow line, allowing the piezoelectric actuator to function both as a control element and as a sensor for detecting the end of injection through the force it experiences during operation.
Solution Approach 2:
The piezoelectric actuator is designed to perform multiple functions: it acts as both the actuating element for controlling the valve and as a sensor for detecting the end of injection. The force transmission element enables this dual functionality by transmitting both the control force and the detection-relevant force information back to the actuator.
2Use of energy by stationary object
If the piezoelectric actuator is installed far from the force flow line, then the valve chamber pressure can be transmitted to the actuator, but only a narrow frequency signal can be detected with significantly reduced gain
Solution Approach 1:
The force transmission element acts as a mechanical intermediary that directly connects the valve chamber pressure source to the piezoelectric actuator. This direct mechanical connection preserves the full frequency spectrum of the pressure variations, including DC components, and transmits them to the actuator without the signal loss and frequency filtering that occurs with parasitic decoupling arrangements.
3Measurement precision
If a guide rod is used to transfer control chamber pressure to the electromagnet arrangement, then the closing times of the nozzle needle can be detected, but the field of application is limited and certain basic conditions must be met
Solution Approach 1:
The force transmission element serves as a universal intermediary that can transmit force information from various pressure sources (valve chamber pressure, control chamber pressure) to the piezoelectric actuator. This makes the system adaptable to different injection valve designs and pressure measurement points, extending the field of application beyond the specific conditions required by the guide rod approach.
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 configuration enables more accurate detection of the end of injection with a broader frequency band, including DC components, and a larger fuel pressure-load range, while reducing the actuator's voltage requirements and prestress, thus improving the robustness and reliability of the detection method.
Implementation Method 1
an actuator (6), in particular a piezoelectric actuator, which actuates the valve closing body (31)
Implementation Method 2
a force transmission element (37), in particular a rigid force transmission element or a force transmission element based on a fuel-resistant, elastic plastic, by which the valve chamber pressure (pV) can be coupled into a prestressing force of the actuator (6)
Implementation Method 3
The control valve arrangement has a sleeve-shaped closing body which is tensioned against a concentric seat by a closing spring
Data Source
Figure 1
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Figure 3
AI summary
A fuel injection valve (1), which is designed in particular as an injector for fuel injection systems of air-compressing, self-igniting internal combustion engines, comprises an actuator (6) and a control valve (30). A valve closing element (31) of the control valve (30) can be actuated by the actuator (6). Furthermore, a force transmission element (37) is provided, which is arranged in the valve closing element (31). The valve closing element (31) is further configured such that an end face (31) of the force transmission element (37) is subjected to a pressure (pv) in a valve chamber (32) of the control valve (30). The force transmission element (37) transmits a force to the actuator (6) that results from the pressure (pv) in the valve chamber (32) being applied to the end face (31) of the force transmission element (37).