The use of biodiesel fuel is growing in popularity as automakers design their diesel engines and fuel systems to accommodate varying levels of this renewable fuel. High temperature fuel modulation for improved engine. It influences the reduction of fuel consumption, ensures more silent engine operation and lower content of hazardous substances in exhaust fumes. Petrol engines can use gasoline direct injection, where the fuel is directly delivered into the combustion chamber, or indirect injection where the fuel is mixed with air before the intake stroke. Automotive technology update hydrogen fuel cell electric. When the injection is complete, the voltage cuts off, the piezo stack shrinks, and a spring closes the pintle. Fit the injector on a vice and loosen the actuator bolt. In the proposed design, a piezoelectric stack actuator is used to directly control the injection of fuel in order to enhance the injection characteristics by utilizing the fast response time of the. If it starts and runs on three cylinders, you have found the dud injector.
Previous injector designs used electromagnetic solenoids to move the injector needle and feed fuel to the combustion chambers. An effective monitoring system is capable of detecting damage, instability, and even the life of fuel injector. Shaver, ranjit more, peter meckl, douglas memering energy center, herrick labs, school of mechanical engineering, purdue university, w. Fuel injection valve operated by expansion and contraction of piezoelectric element gb2303403a en 199507. New automotive fuel injector actuator technology rivals piezo. This led to the invention of piezoelectric diesel injectors. The bosch piezoelectric crystal injector operates using a crystal stack, usually quartz, that changes size when. Assembled a gasassisted simplex injector for detailed performance evaluation fabricated a prototype piezoelectric injector for evaluation of driver electronics and injector operating parameters analyzed various injector and mixing chamber configurations for.
Furthermore the mechanical control of the varying injection pressures within the unit injector has. Jan 20, 2011 common rail diesel fuel injection is now the state of the art in engine injection. Nov 09, 2019 piezoelectricity is also used, much more crudely, in spark lighters for gas stoves and barbecues. Design and development of a directacting piezoelectric. Hydrogen is considered an attractive clean alternative fuel for automobile and power generation applications.
Operation of piezoelectric common rail injector with diesel. On a piezo injectors the functions of opening and closing are actuated only through the polarity inversion disconnecting an injector on a running engine, the injector may remain open, causing big damages to the engine. Also, hdd fuel injector will be designed and mmercialized by cummins. Three parameters, namely, pulse width at 5, 10, and 15 ms. Piezoelectric and dielectric coefficients d 31 and. In the event of a restricted fuel filter or line blockage, the pump is capable of producing pressures of 700 kpa 100 psi or higher. The piezo actuator is therefore formed by 350 quarz sheets, each one 80. The need for technology to meet fuel economy and exhaust emission challenges drove improvements. Bosch, continental, and delphi, among others, have harnessed this peculiar property of expanding piezo materialrather than the usual electromagnetto open the fuelinjector nozzle and precisely spray fuel into both gasoline and diesel engines. Depending on the injector and control system you would even add cylinder and railpressure into the mix. Where i worked, each individual injector was tested and calibrated, with the chart coded into a 2dbarcode etched on the injector. Abstract in the case of direct injection internal combustion engines, the problem occurs that especially the injection of a minimum amount of fuel depends in particular on different operating parameters such as the speed, the start of the injection or the rail pressure. A piezoelectric injector for fuelinjection systems of internal combustion engines has a piezoactuator guided with spring pretensioning in a valve housing. Us6085990a piezoelectric injector for fuelinjection.
A more recent challenge for fuel injector design is the desire from engine designers to have several fuel injection events per engine cycle, an initial opening, the main opening, and also a post. The fuel injection system includes at least one fuel injector having an axially extending fuel passage therein, a control chamber disposed in the injector, an injector valve axially movable within the fuel passage in accordance with a fuel pressure in. Piezoelectric effect for energy harvesting examples of piezoelectric energy harvesters from raw harvested energy to usable power supply prototypes of batteryless autonomous sensor modules conclusions v. In this study, a test rig on fuel injector using piezoelectric film sensor has been developed. Piezoelectric devices for vibration energy harvesting. Proceedings of the 2009 ifac workshop on engine and powertrain control, simulation and modeling ifp, rueilmalmaison, france, nov 30 dec 2, 2009 dynamic modeling of a piezoelectric actuated fuel injector chris a. Fuel rail port injection the fuel rail or ring acts as a manifold supplying fuel to each injector. Piezoelectricity is also used, much more crudely, in spark lighters for gas stoves and barbecues. As the name says, the solenoid valve has been replaced by a faster and more controllable piezo valve. Automotive technology update hydrogen fuel cell electric vehicles automotive technology update may 2019. Feb 18, 2015 bosch, continental, and delphi, among others, have harnessed this peculiar property of expanding piezo materialrather than the usual electromagnetto open the fuelinjector nozzle and precisely spray fuel into both gasoline and diesel engines. Continental injector has hundreds of little piezo slices on top of each other so that the combined expansion the total motion.
Alp sehirlioglu case western reserve university purpose project goal is to develop high temperature piezoelectric fuel injector technology that can be integrated in turbo engine to achieve lean fuel combustion lfc. Piezoelectric fuel injector for a diesel engine 1600. Thirdgeneration common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up. Design optimization of piezoceramic multilayer actuators for. A piezoelectric injector for fuel injection systems of internal combustion engines has a piezoactuator guided with spring pretensioning in a valve housing. Common rail systems crs3 with 1,800 to 2,000 bar and piezo. Design optimization of piezoceramic multilayer actuators. Nov 26, 2012 this dissertation summarizes the stages in the design, prototyping and experimental analysis of a directacting piezoelectric fuel injector concept. For example, if the enginecontrol computer calls for an injectoropening time of 0. Marren fuel injection stocks a large inventory of fuel injection components, including fuel pumps, sensors, etc. Design and development of a directacting piezoelectric fuel injector hirmand nouraei masters of applied science department of mechanical and industrial engineering university of toronto 2012 abstract manufacturers face the challenge of enhancing fuel efficiency, engine performance, and reducing harmful emissions.
Emissions, operating noise and engine power characteristics are also important. This dissertation summarizes the stages in the design, prototyping and experimental analysis of a directacting piezoelectric fuel injector concept. These injectors are used in both petrol and diesel engines to improve their persformance and efficiency. In the proposed design, a piezoelectric stack actuator is used to directly control the injection of fuel in order to enhance the injection characteristics by utilizing the fast response time of the actuator. Piezo electricity results from squeezing or applying pressure from.
Common rail direct fuel injection is a direct fuel injection system for diesel engines it features a highpressure over 2,000 bar or 200 mpa or 29,000 psi fuel rail feeding solenoid valves, as opposed to a lowpressure fuel pump feeding unit injectors or pump nozzles. Design and development of a directacting piezoelectric fuel. It consists of multiple hydraulic and mechanical components for the modeling. Although the experimental study of the static and dynamic behavior of piezoelectric stack actuators has received some attention i. Injectors principle of operation turbotec united kingdom.
Selfheat generation in piezoelectric stack actuators used. Press a lighter switch and youll hear a clicking sound and see sparks appear. Therefore, a method or a device is suggested in which a control unit. Piezo injectors use piezoelectric technology to open and close fuel injectors at extremely high speeds and precision to inject fuel into an internal combustion engine. Piezo wafers expand when voltage is applied to them. A common rail fuel injector utilizes a piezoelectric actuator 8 to open and close the injector valve 3. Shaver energy center, herrick labs, school of mechanical engineering, purdue university, w. The commonrail system with piezo injectors by bosch enables the flexible injection of fuel at pressures up to 2,700 bar. Manufacturers face the challenge of enhancing fuel efficiency, engine performance, and reducing harmful emissions. Diesel engines equipped with piezoelectric and solenoid.
Often limits of knowledge, technology or manufacturing capability governed the chain of improvements. High precision from the rail to the combustion chamber. Piezoelectric actuators are increasingly used for the electronic control of fuel injector opening valves. A fuel injection system is provided for controlling fuel pressure in a common rail through the use of a piezoelectric actuated fuel injector. Finally, since the fuel pressure tends to close the pilotvalve in piezoelectric injectors, but. This paper outlines the development of an 11 state simulation model for a piezoelectric fuel injector and associated driver that can be used for injector design and control system verification.
The injection process is initiated by the control unit via the electrical connection. What are piezo diesel injectors and how do they work. The actuator presses a sealing piece onto its valve seat through an actuating part, with the actuating part consisting of a pressure pin passing through the piezoactuator and having a head part resting on piezoactuator. Piezo fuel injectors cri4, which use piezo crystals as part of a rapid actuator, are helping manufacturers to meet their euro 6 target. Monitoring system of fuel injector using piezoelectric. Selfheat generation in piezoelectric stack actuators used in. Utilizing these noted characteristics of piezoelectric crystals, piezo crystals thus found its use as a critical component in the piezoelectric injector. The injector is permanently supplied with fuel from the rail via the highpressure connection. New automotive fuel injector actuator technology rivals. Piezo injectors have a few key benefits that justify all of this bother. Current understanding of the performance of piezoelectric actuators in a hydrogen environment is very limited. On the verge of liquidation, delphi intros new direct piezo.
The paper is devoted to the theoretical and experimental analysis of the piezoelectric injector of a modern common rail system. Innovative injection and mixing systems for diesel fuel. Feb 02, 2011 for example, if the enginecontrol computer calls for an injector opening time of 0. In piezo injectors, a stack of piezo crystals expand when an. A detailed onedimensional dynamic model of the injector is created using avl software hydsim. With their ability to expand rapidly when in contact with an electrical charge, piezoelectric crystals serve as efficient actuators in diesel fuel injectors. Fuel system pressures must be released and the fuel tank cap removed before loosening filter lines. High temperature fuel modulation for improved engine performance investigators. Intermediate the piezoelectric actuator and the injector valve are a large diameter first piston 9 in fluid communication with a smaller diameter second piston to multiply the actuation extension of the piezoelectric actuator. What youre doing, when you press the switch, is squeezing a piezoelectric crystal, generating a voltage, and making a spark fly across a small gap.
Pull the connector off an injector and start the engine. Even so, the total expansion of many wafers stacked together is only a few thousandths of an inch. High temperature fuel modulation for improved engine performance. Instead of forcing open the fuel injector nozzle, the wafer stack is used to control fuel flow inside the injector. The main focus of this master thesis work was to model a piezoelectric injector in gtfuel. An increasing desire for flexibility in a diesel engines fuel. Different controlling parameters were employed to obtain a better understanding of the heating mechanisms of the actuators. If you require a fuel system component at the time of your injector service, please let us know and we will provide you with a price quote and availability.
Measure and compare piezoelectric and mechanical reliabilities of tapecast and pressed pzt piezoceramics. How bosch piezoelectric diesel injector works youtube. Fuel injection systems diesel ruimanuelvieirapinto 1090039 sistemas automoveis anolectivo20092010 fuel injectionsystems diesel sistemas automoveis anolectivo20092010 1 basic diesel fuel systems 2 injection pumps 3 injectors 4 inline injection pump 5 radial rotary injection pump 6 electronic injection systems 7 bibliography. Novel fuel injection technologies can assist in meeting such demands. Injecting fuel in smaller volumes, more frequently and more highly atomised produces less unburned fuel and, in turn, a cleaner burn with less emissions. Furthermore, a piezoelectric injector consumes less power and requires a lower current than a solenoid injector, because a solenoid injector is operated by the peak and hold method, which needs a boosted high operating current for a fast response. Pressurized fuel can spray for a long distance, causing personal injury or a fire. A piezoelectric diesel injector delivers atomized fuel directly to the engine combustion chamber when signaled to do so by the engine control module ecm. On the verge of liquidation, delphi intros new direct. Dynamic modeling of a piezoelectric actuated fuel injector. Jan 22, 2011 common rail diesel fuel injection is now the state of the art in engine injection. The injected fuel quantity is proportional to the injector duration opening time, fuel rail pressure, fuel temperature and fluid viscosity. A fuel injection system for controlling fuel pressure in a common rail through the use of a piezoelectric actuated fuel injector, comprising.
Design of a dynamic fuel flow estimator for a piezoelectric. The digital rate shaping strategy drs contributes to a very small delay between preinjection and main injection. Common rail diesel fuel injection is now the state of the art in engine injection. The main focus of this master thesis work was to model a piezoelectric injector in gt fuel. An excess pressure valve relief valve is built into the pump gasoline and diesel fuel injection. Common rail systems crs3 with 1,800 to 2,000 bar and piezo injectors fuel consumption is an important economic factor for the market success of a vehicle. With common rail systems of third generation, piezoelectric injectors have appeared. Calibration and then you basically get a chart that matches delivered fuel amount with control impulse time. The performance of a fuel injector greatly influences the performance of a vehicle engine. Pull off, test and replace connectors until you find the dud injector.
1412 265 1316 1511 833 869 428 873 138 524 280 308 633 1379 682 244 1381 1454 418 267 1000 1361 1228 961 1105 429 1282 758 490 1117 846 238 559