The piston moves up and down in the cylinder, the lowest point where the piston goes down is called bottom dead center, and the position where it goes up to the top is called top dead center. The distance between top dead center and bottom dead center is called the stroke. When the piston is at top dead center, the space at the top of the piston is called the combustion chamber.
Intake stroke
When the piston descends from top to bottom dead center in the cylinder, the intake valve is opened and the exhaust valve is closed, a partial vacuum can be generated in the cylinder, and the mixture of fresh air and gasoline is sucked into the cylinder.
compression stroke
Both the intake valve and the exhaust valve are closed, and the piston moves upward from the bottom dead center to the point, compressing the air mixture in the cylinder. The more air mixture enters the cylinder, the closer the piston is to the dead center position, the greater the compression force. During the compression stroke, the maximum pressure of the mixture in the cylinder is called the compression force. The mixed gas pressure is programmed to make the mixed gas more uniform, and to increase the temperature to be easy to burn, so as to obtain greater power.
work stroke
After the intake valve and exhaust valve are closed, the spark plug jumps out of the high-voltage electric spark to ignite the mixture in time, so that the combustion well explodes with strong excitation, and pushes the piston from the top dead center to the bottom dead center. The high-voltage spark of the spark plug comes from the high-voltage coil, which can amplify the spark energy, and then the electronic control unit (ECU) distributes the high-voltage spark to each cylinder in order, thereby igniting the compressed mixture.
Exhaust stroke
The piston goes up from the bottom dead center to the address point, at this time the intake valve is closed, the exhaust valve is opened, and the exhaust gas that has been burned by the cylinder moves upwards from the piston, and is discharged into the atmosphere through the exhaust valve and the exhaust manifold. After the burnt exhaust gas is muffled by the muffler, the bad shovel generates too much noise.
