Download
1 / 28
310 likes | 462 Vues
Ag Science and Tech. Small Gas Engines. Understand correct safety procedures when working with small gas engines in the shop. Identify tools used when working with small gas engines. Describe the strokes of 2-stroke and 4-stroke engines.
E N D
Ag Science and Tech Small Gas Engines
Understand correct safety procedures when working with small gas engines in the shop. Identify tools used when working with small gas engines. Describe the strokes of 2-stroke and 4-stroke engines. Define the components of a small gas engine and their functions. Objectives
Engine Internal combustion engine Piston Piston rings Connecting rod Crankshaft Crankcase Valves Terms • Intake valve • Exhaust valve • Valve lifters • Cylinder head • Camshaft • Carburetor • Flywheel • Spark plug
Engine • A device for converting chemical energy into mechanical energy. • Internal combustion engine • Device that burns fuel inside a cylinder to create a force that drives a piston. Function of engines
Safety glasses must be worn at all times. Keep hands and feet away from all moving parts during operation. Keep all ignition sources away from the work area. Stop engine and allow it to cool before refueling. Handle gasoline outdoors if possible. Disconnect the spark plug lead when making adjustment to prevent accidental start-up. Never disengage any of the safety equipment or devices. Safety
Keep all shields in place. Do not operate engines above the specified speed. Never overload engines or force equipment beyond it the designed capacity. Never use gasoline as a solvent to clean parts. Only start and run engines where ventilation is adequate, preferably outdoors. Never pour gasoline or oil on the ground or down a drain, dispose of it in the correct container to be recycled. Safety
Piston Crankshaft Crankcase Valves Camshaft Cylinder Cylinder head Carburetor Flywheel Spark plug Engine components
Located in the cylinder Piston rings- an expanding ring placed in the grooves of the piston to seal it against the passage of fluid or gas. piston
Piston is connected to the crankshaft by the connecting rod. Connecting rod
Holds the crankshaft in place. Also houses the camshaft and oil. crankcase
Intake valve • Allows air/fuel mixture to enter the combustion chamber. • Exhaust valve • Allows fumes to exit the cylinder. • Valve lifters • Moves the valves up and down • Powered by the camshaft Valves
Operates opening and closing of the valves. Rotated by a gear on the crankshaft. Camshaft
Combustion chamber Where the piston is located Cylinder head- seals the cylinder cylinder
Mixes air and fuel before it is pulled into the combustion chamber. Carburetor
Turned by crankshaft to induce electrical current with magnet through the magneto. Momentum flywheel
Supplies spark. Spark plug
Combustion Compression 2-stroke engines
Intake Compression Power Exhaust 4-stroke engines
2- or 4-stroke • Amount of power they produce • <25 hp = small engine • >25 hp = large engine • Number of cylinders • Single-cylinder • Multi-cylinder Classifying engines
Engine displacement • Total swept volume of the engine cylinders as the piston completes one stroke. • Cylinder arrangement • In-line • Vee-block • Fuel • Gasoline • Diesel Classifying engines
