Main Functions and Importance:
Engine/Machinery Protection: Prevents impurities such as sand and dust from entering the cylinders, reducing wear on precision components such as pistons, cylinders, and valves, preventing cylinder scoring.
Performance Guarantee: Provides sufficient clean air, maintaining the engine's optimal air-fuel ratio, preventing carbon buildup, and ensuring power output and fuel efficiency.
Environmental Improvement: In residential/commercial settings, it purifies indoor air, removes pollutants, and protects health.

Types and Operating Methods:
Automotive Air Filters: Typically consist of a filter element and a housing, mostly dry-type (filter paper/non-woven fabric), with a pleated design to increase the filtration area.

Filtration Methods:
Filter Type: Uses filter paper/screen to block impurities (most common).
Inertial Type: Uses airflow rotation or sharp turns to throw out denser impurities.
Oil Bath Type: Dust-laden air impacts the oil sump, trapping most dust, which is then further filtered by an oil mist filter.
Multi-Stage Filters: Includes a coarse filter (cyclone type), a main filter (fine filtration), and a safety filter (backup protection).

Maintenance and Replacement:
Inspection and Cleaning: Lightly soiled areas can be cleaned with compressed air.
Timely Replacement: Replace when severely contaminated or when the maintenance cycle has been reached. Replacement intervals depend on the operating environment (e.g., sandy environments cause faster wear).
Inferior Filters: May cause insufficient or excessive air intake, poor filtration, and serious damage to the engine.

Application Scenarios:
Automotive/Transportation: Engine intake.
Industrial/Commercial: Clean rooms, precision operating rooms, air compressors, etc.
Residential/Commercial: Air purifiers, air conditioning systems.