外文翻譯--半機(jī)電性氣門在一臺單缸火花點(diǎn)火發(fā)動機(jī)排放影響

1、1Effect of a semi electro-mechanical engine valve on performanceand emissions in a single cylinder spark ignited engine(Department of Automotive Education, Karabuk University, Karabuk 78050, Turkey)E-mail: ozdalyan@hotma

2、il.com; dogan_oguzhan@yahoo.co.ukReceived Feb. 25, 2009; Revision accepted July 7, 2009; Crosschecked Nov. 8, 2009Abstract: In this study, an electro-mechanical valve (EMV) system for the intake valve of a four stroke,

3、single cylinder, overhead valve and spark ignition (SI) engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emi

4、ssions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption (BSFC). A 66% decrease in CO emissions was also obtained with the EMV system, but

5、 hydrocarbons (HC) and NOx emissions increased by 12% and 13% respectively. Key words: Semi electro-mechanic, Camless engine, Electro-mechanic engine valve, Engine performance, Emissions doi:10.1631/jzus.A0900119 D

6、ocument code: A CLC number: TH131.Introduction All internal combustion engines (ICE) have mechanically actuated systems for opening intake and exhaust valves. Traditional valve systems have con-stant valve timi

7、ng which restricts engine performance especially at low and at high engine speeds. Control-ling valve operation in ICE’s effective method for improving engine performance and emissions over a range of engine speeds. Para

8、meters such as cam shape, valve timing, valve opening duration and valve lifting have a major impact on engine performance and emissions (Barkan and Dresner, 1989; Krauter et al., 1992; Hatano et al., 1993; Cinar, 1998;

9、Akba, 2000; Pischinger et al., 2000; Stein et al., 1995). To increase torque and reduce fuel consumption in gasoline engines, manufacturers are increasingly using variable valve timing systems in production engines. Most

10、 valve timing systems used for improving engine performance are dependent on the camshaft. The mechanical variable valve timing systems are complex but greatly reduce the limitations of traditional valve systems, especia

11、lly in regard to volumetric efficiency (Barkan and Dresner, 1989). However, except for BMW’s Valvetronic system, they cannot control all parameters such as valve timing, valve lifting and valve opening duration simultane

12、-ously, continuously and completely 3camless engine has not yet been produced.n this study an EMV system was designed based on systems built by other engineers. The EMV engine (a semi electro-mechanical camless engine),

13、which enables electro-mechanical operation of the intake valve, and a standard engine were tested to understand the effect of EMVs on engine performance and emissions at different engine speeds under load. During the eng

14、ine tests engine valve timing, valve opening duration and ignition timing were kept constant to observe the effects of the EMV system alone. 2. Electro-mechanical valve system The components that comprised the electro- m

15、echanic valve actuator (EMVA) were similar to those of other systems (Stubbs, 2000; Boie, 2001; Wang, 2001; Chang et al., 2002; Tai, 2002; Wang et al., 2002; Hoffmann and Stefanopoulou, 2003; Nitu et al., 2004; Peterson

16、and Stefanopoulou, 2004; Kamis and Yuksel, 2005; Copeet al., 2008). They included an engine valve, two electro-magnets, an actuator spring and a valve spring. The diagram of an EMVA that is commonly used is given in Fig.

17、 1. Principally, the actuator is like an oscillating mass-spring combination and is activated by an electro-magnetic force. The potential energy is transferred between two springs via the core and the valve throughout n

18、ormal operation. The voltage is applied to the relevant coil during the transition. The magnetic force formed overcomes the spring, friction and gas flow forces. The upper coil closes the valve and the lower coil opens i