Effects of needle response on spray characteristics in high pressure injector driven by piezo actuator for common-rail injection system |
| |
Authors: | Jinwook Lee Kyoungdoug Min |
| |
Affiliation: | (1) School of Mechanical and Aerospace Engineering, College of Engineering, Seoul National University, San 56-1 Shinlim-Dong, Kwanak-Ku, 151-742 Seoul, Korea |
| |
Abstract: | The common-rail injection systems, as a new diesel injection system for passenger car, have more degrees of freedom in controlling
both the injection timing and injection rate with the high pressure. In this study, a piezo-driven injector was applied to
a high pressure common-rail type fuel injection system for the control capability of the high pressure injector’s needle and
firstly examined the piezo-electric characteristics of a piezo-driven injector. Also in order to analyze the effect of injector’s
needle response driven by different driving method on the injection, we investigated the diesel spray characteristics in a
constant volume chamber pressurized by nitrogen gas for two injectors, a solenoid-driven injector and a piezo-driven injector,
both equipped with the same injection nozzle with sac type and 5-injection hole. The experimental method for spray visualization
was based on back-light photography technique by utilizing a high speed framing camera. The macroscopic spray propagation
was geometrically measured and characterized in term of the spray tip penetration, spray cone angle and spray tip speed. For
the evaluation of the needle response of the above two injectors, we indirectly estimated the needle’s behavior with an accelerometer
and injection rate measurement employing Bosch’s method was conducted. The experimental results show that the spray tip penetrations
of piezodriven injector were longer, on the whole, than that of the solenoid-driven injector. Besides we found that the piezo-driven
injector have a higher injection flow rate by a fast needle response and it was possible to control the injection rate slope
in piezo-driven injector by altering the induced current. |
| |
Keywords: | Piezo Actuator Injector Diesel Spray Common-rail Type Fuel Injection System |
本文献已被 SpringerLink 等数据库收录! |
|