What happens when the piston in the compression chamber moves down?

When the piston in the compression chamber moves down, it creates a vacuum effect in the cylinder. As the piston descends, it increases the volume of the chamber, which reduces the pressure inside. This lower pressure relative to the outside atmosphere causes air to be drawn into the cylinder through the open intake valve. This process is essential in the intake stroke of an engine, where the primary goal is to fill the combustion chamber with air (or a mixture of air and fuel) for the subsequent compression and combustion phases.

As the piston moves down, the air enters the cylinder, preparing it for the next cycle of the engine's operation. Understanding this mechanism is crucial for those studying engine functionality within the context of mechanical systems or emergency response equipment utilized by fire departments, such as compressors for breathing apparatus or power tools.