Engines Exercises

     1. Please answer the following three questions

    1) Identify and locate the major parts of a typical automotive engine.

    2) Describe the four-stroke cycle.

    3) Explain the basic function of the major parts of an automotive engine.

    2. Translate伪e following sentences into Chinese

    1) By definition an automobile or car is a wheeled vehicle that carries its own motorand at some point after the air cleaner, depending on the engine，fuel is added to the air-stream by either a fuel injection system or, in older vehicles, by the carburetor.

    2) As the pistons move up and down, they turn the crankshaft just like your legspump up and down to turn the crank that is connected to the pedals of a bicycle.

    3) The automobile's further development will be determined by already existing andsteadily increasing requirements，by additional further requirements and by the technicalpossibilities for meeting these requirements. The following focal points for developmentand research efforts can be discerned.

    4) Further improvements of the automobile through product innovation in all classicfunctions, i. e.，performance, fuel economy, environmental impact, safety，comfort andreliability.

    5) A car usually has a piston engine. It consists of several moving parts：pistons,connecting rods，crankshaft, camshaft，valve lifters, intake valves and exhaust valves.The cast-iron or aluminum engine block holds the moving parts. The engine block has aseries of holes which are called cylinders. The cylinders can be arranged in line or in a V-shape and in the upper part of the block. Each cylinder holds a piston and connecting rod.A circular ring is used to seal the small gap between the piston and the cylinder wall. Thelower part of the block is called crankcase which holds the crankshaft with bearingmounts. Pistons are connected to the crankshaft by connecting rods.

    6) The cylinder heads are the top covers of the cylinders which are tightly bolted tothe top of the block. The cylinder heads contain combustion chambers. Each combustionchamber contains at least one intake and exhaust valve and one spark plug per cylinder.The valves are opened and closed in a specific sequence with valve lifters controlled by thecamshaft. The camshaft is connected to the crankshaft through a time belt.