Mechatronic design and analysis of a solenoid based injector

Abstract

Injectors are devices for producing spray, namely, for creating small liquid droplets. In the automotive industry, generally, the injectors are used to inject fuel into the combustion chamber. In recent years, systems are developed to clean the exhaust gases produced by the diesel engines. In these systems, injectors are also used to reduce the NOx emissions, which are harmful to the environment, by spraying urea solution to the exhaust gas. Injectors are compact systems with parts like atomizer, actuator, plunger, spring, needle, and seat. The design process of each component is separate, but they must be designed together. Once assembled, replacing parts of the system can be quite challenging. The aim of this thesis is to design a modular solenoid-actuated injector mechanism so that tests with a variety of subsystem components could be conducted. In this thesis, the working principles of solenoid actuators used in injectors have been studied. An injector mechanism which is modular in all parts has been designed, produced and tested. The components of this modular design can be changed independently, and the e ciency of the updated system can be investigated. This mechanism has shortened the injector development and testing process. The prototype was tested in demanding conditions similar to commercial injectors and successfully opened in 1.2 milliseconds at 80-micrometer displacement under 5 bars liquid pressure.

Enjekt orler, k u c uk s v damlac klar olu sturmak i cin kullan lan cihazlard r. Otomotiv end ustrisinde, genel olarak enjekt orler yanma odas na yak t p usk urtmek i cin kullan l r. Son y llarda, dizel motorlar n n uretti gi egzoz gazlar n temizlemek i cin, baz sistemler geli stirilmi stir. Bu sistemlerde, enjekt orler ayr ca cevreye zararl olan NOx emisyonlar n azaltmak amac yla egzoz gaz na ure c ozeltisi p usk urtmek i cin de kullan lmaktad r. Enjekt orler; atomizer, akt uat or, piston, yay, i gne ve oturak gibi par calara sahip kompakt sistemlerdir. Her bir bile senin tasar m s ureci ayr d r, ancak birlikte tasarlanmalar gerekir. T um enjekt or bir kez monte edildi ginde, sistemin par calar n de gi stirmek olduk ca zor olabilir. Bu tezin amac , mod uler olarak enjekt or mekanizmas tasarlamakt r, b oylece her bir par can n farkl modelleri ile testleri yap labilir. Bu tez cal smas nda, enjekt orlerde kullan lan solenoid akt uat orlerin cal sma prensipleri incelenmi stir. T um par calar mod uler olan bir enjekt or mekanizmas tasarlanm s, uretilmi s ve test edilmi stir. Bu mod uler tasar m n bile senleri, ba g ms z olarak de gi stirilebilir ve g uncellenmi s sistemin verimlili gi ara st r labilir. Bu mekanizma, enjekt or geli stirme ve test s urecini k saltmaktad r. Prototip, ticari enjekt orlere benzer zorlu ko sullarda test edildi ve enjekt or i gnesini 1.2 milisaniyede, 5 bar s v bas nc alt nda, 80 mikrometre yer de gi stirerek ba sar yla a c ld .