Fuel Injector Needle Position Detection via Flexible Contactor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fuel injector systems face challenges in accurately detecting the needle position due to alignment issues and play in the needle seat, leading to false contacts and inefficiencies, particularly in high-speed operations.
Innovation Solution
A fuel injector with a detection device featuring a contactor element actuated by the needle, which forms a switch-like detection circuit, eliminating the need for insulating and resistive layers, and utilizing a flexible contactor element that changes configuration with the needle's movement to maintain reliable contact detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor or insulating surface measurement device is used to detect needle position, then measurement capability is provided, but device complexity and cost increase significantly
Solution Approach 1:
The invention extracts the detection function from complex sensor systems and insulating surface measurements, removing these complicated components while retaining the essential position detection capability through a simplified mechanical contact approach
Solution Approach 2:
Instead of using complex sensors to detect position, the invention inverts the approach by using a simple electrical contact system where the needle itself acts as part of the detection circuit, eliminating the need for separate sensing components
2Ease of manufacture
If needle tolerances are relaxed for easier manufacture, then manufacturing precision decreases, but manufacturing ease improves
Solution Approach 1:
The invention performs preliminary action by detecting needle position through electrical contact before injection occurs, allowing verification of proper alignment and positioning in advance, which compensates for manufacturing tolerances
Solution Approach 2:
The invention introduces an electrical contact system as an intermediary between the needle and detection circuitry, providing a reliable detection mechanism that is tolerant of manufacturing variations in the needle itself
3Reliability
If the contactor element is rigid for stable contact, then contact reliability improves, but adaptability to needle movement decreases
Solution Approach 1:
The invention applies dynamics by making the contactor element flexible rather than rigid, allowing it to adapt its shape and position dynamically in response to needle movement while maintaining reliable electrical contact throughout the range of motion
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 solution provides a reliable and efficient method for detecting the needle's position, reducing false contacts and improving alignment, thereby enhancing the accuracy and quality of fuel injection operations.
Implementation Method 1
The contacting element includes a flexible part which is configured in the closed position of the needle so as to be in electrical contact with the terminal; the configuration of the flexible part changes when the needle leaves the closed position so as to interrupt the electrical contact with the terminal
Data Source
Figure 1a
Figure 1b~1c
Figure 2~3
AI summary
A fuel injector for an internal combustion engine, comprising: an injection nozzle (12) with a body (16) in which a needle (14) is arranged; a control chamber (46) collaborating with a control valve driven by an actuator. A device for detecting the position of the needle comprises a contactor element (62) actuated by the upper part of the needle (42), the device being designed so that the contactor element is in contact, in the closed position, with terminal-forming element (64) of the position detection device, and so that the lifting of the needle causes a break in contact. The contactor element may be a spring, installed in the control chamber (46) and which is deformed radially in the closed position so as to touch an end of a rod and thus close the detection circuit.