Читать книгу Internal Combustion Engines - Allan T. Kirkpatrick - Страница 36

A heavy‐duty truck diesel engine is shown in Figures 1.22. This engine is an inline six‐cylinder turbocharged diesel engine with a 137‐mm bore and 165‐mm stroke for a total displacement of 14.6 L. The rated engine power is 373 kW (500 hp). The compression ratio is 16.5 to 1. The engine has electronically controlled, mechanically actuated fuel injectors, and an overhead camshaft. Note that the cylinder head is flat, with the diesel fuel injector mounted in the center of the combustion chamber. The inlet ports impart a swirl to the air in the combustion chamber to improve mixing with the radial fuel spray.

The top of the piston has a torus‐shaped crater bowl, so that the initial combustion will take place in the piston bowl. The injection nozzles have three to six holes through which the fuel sprays into the piston bowl. The pressure required to spray the diesel fuel into the combustion chamber is of the order of 1000 bar, for adequate spray penetration into the bowl and subsequent atomization of the diesel fuel. The fuel injection pressure is generated by a plunger driven by the camshaft rocker arm.

Figure 1.22 A 5.9 L L6 on‐highway diesel engine. (Courtesy of PriceWebber.)