04014 - Fuel Injector Drip Sensor Test Stand Jason Chekansky Project Manager, ME Hugh Campbell Lead Engineer, ME Peter Boyer ME Matthew Kubarek ME Brian Crawford ME Richard Peffer III EE Courtney Stout - IE Dr. Alan Nye Faculty Mentor Lee Markle Delphi Representative
Original Set-up and Test LabVIEW based control Single injector testing capabilities 10-20 minute tests Manual system requires constant user input
Problem Statement Research, design, and implement an automated fuel injector drip sensing system. Sensing system to integrate with fuel injector control already in use. Design of a test chamber to house the fuel injectors and sensing system.
Design Objectives Detection and time stamping of drips Sensing function automated after start of test Capability to test 80% of Delphi injectors Set-up time < 10 min per injector Results must be collected in LabVIEW Injectors capable of rotating 0 o to 90 o Test enclosure withstands full vacuum Comply with Delphi standard safety guidelines Payback within 6 months
Developed Concepts: Drip Sensing Accelerometer detects the impulse transferred from the drip falling from the tip of the fuel injector Diaphragm Accelerometer
Developed Concepts: Drip Sensing Natural Frequency -1239 rad/s Damping Ratio 0.0459 Sensor Assembly capable of accurately detecting up to 10 drips per second 1 0.9 0.8 0.7 Decay Envelope Analytical Ideas Expimental 0.6 g 0.5 0.4 0.3 0.2 0.1 0 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 time, s ec
Developed Concepts: LabVIEW Interface LabVIEW program monitors analog channels from each accelerometer Voltage values are compared to a limit that will be surpassed only when a drip excites the sensor When the limit is surpassed, an elapsed time value will be added to an array of drip times Test information and the drip time arrays are imported into an existent, formatted MSExcel sheet A graph of times versus drips is created in a linked MSExcel chart The fuel injectors are driven through a digital pulse frequency resultant from the values the operator enters for the cycle period and injector on time
Developed Concepts: Test Enclosure Test Enclosure Top Lexan Viewing Window
Developed Concepts: Test Enclosure Components Test Enclosure Polycarbonate viewing window Pressure relief system Design for full vacuum load Fuel Injector Positioning System Provides 90 o of rotation Fuel injector tip remains at axis of rotation Quick orientation changes with pin- lock system Fuel Injector Adapter Multiple lengths to accommodate different styles of injectors Fuel rail style attachment Simple installation to positioning system
Implementation: Sensor Accelerometer adhered to bottom of diaphragm Diaphragm securely mounted between clamp-ring and base fixture 7.5 o offset allows fuel drips to run off diaphragm
Implementation: Hardware Input from accelerometers passes through the signal conditioner, external BNC board, and PCI card integrated in the lab computer BNC board relays analog voltage input (0-100mV) to channels read by the LabVIEW software PCI card reads these channels in order at 250 Hz Accelerometer Signal Conditioner BNC Board PCI Card
Implementation: Software
Implementation: Enclosure Test enclosure was tested for air leaks while under vacuum Vacuum was run and gauged at 10 kpa absolute Aluminum grate allows fuel vapors to be evacuated
Financial Analysis Accelerometer Sensor System: $ 5,131 Major Components Accelerometers (6), Signal Conditioner, DAQ Card, Cables, and BNC Connectors Test Enclosure: $ 3,399 Major Components Aluminum Test Enclosure, Injector Positioning System, Polycarbonate Viewing Window, and Buna-N N Seals Minor Components and Hardware: $ 83 Aluminum Stock, Plumbing, and Hardware Target Actual Budget $ 7,000 $ 8,613 Return on Investment 6 months 7 months
Conclusions 1. 2. 3. 4. 5. 6. 7. Fit into assigned workspace Withstand full vacuum Capture entire range of drips @ 45 o injector angle 4 to 6 fuel injectors to be tested at once Setup time less than 10 minutes per test per injector Programming in LabVIEW Adhere to standards and codes pertaining to Delphi considerations s for drip test stand (section 3.9) 8. 9. 10. 11. 12. 13. 14. 15. IPS to accommodate orientation range (0 o 90 o ) Automated drip detection Explosion proof quiescent test chamber All drawings in.dwg. format Under Delphi approved budget of $7000.00 Fuel resilient exposed components Resolvable error detection (distinguish fuel drip from vapor) Sensor repeatability
Implementation Issues Signal Output/ Noise Interference Variables: -Cable noise -Environmental noise -Fuel injector pulse noise Solution 1. Systematic approach to determine source of noise 2. Work will continue throughout the next week to provide a solution to the drip detection problem