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CMC INTERNATIONAL
Changzhou Cranes Mechanical Electrical Engineering Co., Ltd. Sandy(Manager) Mobile no. 0086-18001505166 Tel: +86-519-81886887 Fax: +86-519-85163887 Add: No.8-20 Shunyuan road, Xinchen industrial park, Xuejia town, Xinbei district, Changzhou city, Jiangsu province, P.R.China. Postalcode: 213125 Email: kaison1110@qq.com craneschina@gmail.com info@craneschina.cn |
The actions taking place in the four stroke engine can be divided into four strokes. The four strokes are intake stroke, compression stroke, power stroke, and exhaust stroke. Then do you know what the stroke is£¿ ¡°Strokes¡± refer to piston movements. A stroke occurs when the piston moves from TDC to BDC or from BDC to TDC. Here TDC means top dead center, the upper limit of piston movement. BDC means bottom dead center, the lower limit of piston movement.
Intake stroke: On the intake stroke, the inlet valve is opened, the exhaust valve is closed. The piston goes downward. The fresh charge is drawn into the cylinders through the open inlet valve. For the gasoline engine, on this stroke, the fresh charge is a mixture of air and vaporized gasoline. While for the diesel engine, the fresh charge is the pure air. Compression stroke: On this stroke, both valves are closed. The piston goes upward. During this stroke, the charge is compressed. Temperature and pressure increase. At the end of this stroke, ignition occurs. In the gasoline engine, it is the electric spark that ignites the mixture of air and gasoline. In the diesel engine, the source of heat for igniting the charge is created within the engine by compressing pure air to a degree that will initiate combustion and then injecting the fuel at the right time. Power stroke: On this stroke, both valves are still closed. The piston goes downward. The fuel begins to burn rapidly. And the temperature and pressure increase sharply. The force of the piston is transferred to the torque of the crankshaft. Exhaust stroke: On this stroke, the inlet valve is closed, the exhaust valve is opened. The piston goes upward. The remaining gases are expelled from the open exhaust valve. |