Understanding Piston Components: Functions and Maintenance

The engine serves as the heart and soul of any vehicle, transforming fuel (gasoline or diesel) into energy that propels the car forward. One of its key components is the piston.

The piston component in a car acts like the heart that pumps power into the engine. For those looking to grasp the piston thoroughly, let's delve into the following article!

What is a Piston?

A piston is a cylindrical-shaped component that moves up and down. Its primary function is to transfer energy generated from fuel combustion to the crankshaft, producing rotational motion.

Moreover, this component is typically made from heat-resistant metals designed to withstand high pressures and temperatures.

Understanding Piston Components and Their Functions

Behind its seemingly simple appearance, the piston features a complex design comprising intricate geometries and components, including:

1. Piston Head The piston head, also known as the crown, represents the top surface of the piston assembly. It withstands extreme temperatures and pressures during engine operation, with heat levels reaching up to 2500°C or higher.

   Therefore, the piston head is usually made from special alloys capable of enduring heat and force compared to other parts of the piston.

   Its design facilitates the distribution of combustion energy to other areas within the piston and downwards to the crankshaft. The primary functions of the piston head include containing combustion pressure and enabling even combustion distribution by rotating the fuel-air mixture.

   Additionally, the piston head serves to protect the components beneath it from heat damage. This component plays a crucial role as a barrier and initiator of crankshaft power in the engine.

   Mechanically, the engine converts explosion energy into up and down motion for the piston rod. Thus, the explosion occurs within the piston head gap and cylinder wall.

2. Piston Skirt This is the component surrounding the cylinder part of the piston assembly, just below the piston pin. The piston skirt is typically grooved and made from cast iron or steel. To prevent the piston from binding at high temperatures, the skirt is often elliptically shaped.

   Its function is to stabilize the piston assembly within the cylinder. Piston movement is typically irregular. Without a skirt, the piston may strike the cylinder walls.

3. Piston Rings The next piston component is the rings or bands. These are circular pieces that fit into grooves in the piston skirt.

   Piston rings serve several functions, including sealing the combustion chamber by maintaining the proper gap between the piston and cylinder walls. Additionally, they help move engine oil up and down the cylinder walls.

   There are three types of piston rings: compression rings, wiper rings, and oil control rings.

   Compression rings are located at the top of the piston assembly. They are also known as pressure rings and prevent combustion gases from leaking into the cylinder bore.

   Next, there are wiper rings that scrape oil from the cylinder walls. The last ring is known as the piston oil control ring. This part serves to wipe oil from the cylinder walls.

   In some pistons, the oil control ring also has small holes to help remove excess oil returning to the engine pan.

4. Connecting Rod This piston component connects to the crankshaft at one end and the piston pin at the other end. It is commonly referred to as a conrod, short for connecting rod.

   Depending on the engine application, conrods can be made from various materials, including steel, aluminum, or iron. In terms of design, this component has three main parts: the small end, big end, and beam.

   The small end connects to the pin, while the big end connects to the crankshaft. Meanwhile, the beam is the part located between both ends. In some pistons, the beam is equipped with holes to allow lubricating oil from the piston rings.

5. Piston Pin The piston pin refers to the shaft connecting the piston to the piston rod. There are four types of connections between the piston and piston pin.

   These types include Bolted Type (connected using screws or bolts), Press Fit (installation of the piston pin by pressing), Fixed (installation of the piston pin by welding), and Full Floating (allows the piston pin to move more flexibly).

   The piston pin's function is not limited to connection but also plays a crucial role in transferring power from the piston to the piston rod.

   Through the piston's reciprocating motion, the piston pin converts linear motion into rotational motion on the crankshaft, which is the core of generating power in the vehicle's engine.

6. Piston Bolt To connect the conrod to the crankshaft, a piston bolt is required. Its purpose is to withstand mechanical pressure from piston rod movement. The bolt is one of the piston assembly components that can be replaced separately.

   There are various designs of piston bolts, including hexagonal, flat, round, raised, threaded or non-threaded. There are also closed bolts and through bolts.

7. Snap Ring To maximize the adhesive force on the piston pin, a snap ring is installed in the hole according to the spatial needs of the piston rod. The snap ring acts as a retainer or lock to ensure the piston pin remains securely in place.

   Without the snap ring, the piston pin may not be properly installed or could even come out of the piston rod hole, leading to more severe damage.

Piston Component Maintenance

To maintain optimal engine performance and longevity, it's essential to take the time to maintain your piston. Here are some methods you can apply:

• Use high-quality fuel to reduce carbon deposits.
• Monitor engine performance for early signs of wear.
• Properly align piston rings.
• Replace spark plugs every 10,000 km to help prevent piston cracking.
• Use a piston ring compressor to insert the piston.
• Regularly change oil and oil filter to prevent dirt and contaminants from clogging piston rings.
• Ensure the cooling system functions properly to prevent the piston engine from overheating.
• Perform routine maintenance according to schedule.

Conclusion

Overall, the piston is an indispensable part of every car. Therefore, the piston component should receive the best maintenance or service to ensure your car's engine performance remains optimal and extends its lifespan.