What is the function and structural form of piston rings
Piston rings are metal rings installed on pistons. Their functions and structural forms are as follows:
The function of piston rings:
Sealing: Ensure the airtightness between the engine combustion chamber and the piston to prevent gas leakage.
Lubrication: During the movement of the piston, the oil film on the cylinder wall is scraped off and brought to the top of the piston, forming lubrication.
Heat dissipation: Transfer part of the gas heat to the cylinder wall and then dissipate it into the air to reduce the engine temperature.
Control exhaust gas emissions: During the movement of the piston, the exhaust gas is sheared to facilitate its discharge.
The structural form of piston rings:
Integral piston rings: Made of a single piece of material, they have a simple structure but relatively low strength and are prone to deformation.
Spliced piston rings: Composed of two or more materials spliced together, they have high strength and are suitable for high-speed and high-load engines.
Combined piston rings: Composed of ring plates of different shapes and materials, they can be adjusted as needed to enhance performance.
These structural and functional designs enable the piston rings to play a crucial role in the engine, ensuring its normal operation and performance.
Piston rings are mainly made of cast iron , and there are also supplementary types such as alloy cast iron, steel and special composite materials.
The main material types of piston rings are
Cast iron materials
Youdaoplaceholder0 Conventional gray cast iron : In China, grades of gray cast iron such as HT250 and HT300 are commonly used. Their metallographic structure should meet the requirements of fine lamellar pearlite matrix and uniform graphite distribution to ensure wear resistance.
Youdaoplaceholder0 alloy cast iron : By adding elements such as Cr, Mo, and Cu to enhance performance, cr-mo and cr-mo-cu alloy cast iron are formed, further strengthening wear resistance and high-temperature resistance.
Special application materials
Youdaoplaceholder0 Steel materials : Steel piston rings are used in high-power engines, and their surface properties are enhanced through processes such as thermal spraying and electroplating.
Youdaoplaceholder0 composite materials : such as piston rings made of MC nylon 6 and molybdenum disulfide filler, which are suitable for specific scenarios like compressors and have the advantages of low friction and lightweight.
Youdaoplaceholder0 material processing and strengthening process
Youdaoplaceholder0 Surface treatment : including techniques such as chromium plating, nitriding, phosphating, and physical deposition, it can significantly enhance wear resistance and corrosion resistance.
Youdaoplaceholder0 Microscopic control : By optimizing the morphology of graphite (such as fine straight flaky or vortex distribution) and adjusting the eutectic structure of phosphorus, the mechanical properties of the material are improved.
Piston ring faults are mainly manifested as abnormal oil consumption, reduced power, and intensified abnormal noise, which are mainly caused by factors such as carbon deposits getting stuck, material defects, or improper installation. Youdaoplaceholder0 Common solutions include targeted treatment plans such as non-disassembly repair, component replacement and working condition adjustment.
Youdaoplaceholder0 Main fault phenomenon
Youdaoplaceholder0 Abnormal oil consumption : Wear or jamming of the piston rings causes oil to enter the combustion chamber, and blue smoke comes out of the exhaust pipe, requiring frequent oil replenishment.
Youdaoplaceholder0 Decline in power performance : Seal failure leads to insufficient cylinder pressure, manifested as weak acceleration and increased fuel consumption.
Youdaoplaceholder0 Abnormal noise and overheating : When the ring breaks or the oil scraping fails, the engine makes knocking sounds, accompanied by an abnormal increase in water temperature.
The standard usage method of piston ring compressors can be divided into five core steps: lubrication preparation, component protection, compressor installation, piston positioning and tool separation . Special attention should be paid to lubrication treatment, component alignment and operation taboos.
Youdaoplaceholder0 Core operating steps
Youdaoplaceholder0 lubrication treatment .
Apply engine oil evenly to the piston ring grooves and the inner walls of the cylinders to reduce the coefficient of friction.
Wipe with a non-fibrous cloth to avoid foreign matter residue affecting the sealing performance.
Youdaoplaceholder0 component protection .
After removing the connecting rod cover, put the rubber hose over the threaded end of the connecting rod bolt to prevent the cylinder wall from being scratched during installation.
Check the direction marking on the top of the piston (such as an arrow) to ensure it matches the engine model.
Youdaoplaceholder0 compressor installation .
Select a compressor model that matches the diameter of the piston and ensure that the rigidity and strength of the iron sheet meet the standards.
Press down the release claw as per the instruction manual, and rotate the ratchet device counterclockwise to unfold the compression ring and wrap around the piston.
Tighten the compressor clockwise to fully embed the piston rings into the ring grooves.
Youdaoplaceholder0 piston positioning .
Insert the lower part of the piston into the cylinder at an Angle and gently tap the top with a wooden mallet handle until the compression ring touches the cylinder plane.
Continuously observe the distance between the big end of the connecting rod and the main journal of the crankshaft to avoid collision accidents.
Youdaoplaceholder0 tool separation .
After confirming that the first piston ring has entered the cylinder, stop striking. It is strictly forbidden to force it forward with metal tools.
Rotate the ratchet release claw clockwise, slowly relieve the pressure of the compressor, and then remove the tool.
Youdaoplaceholder0 Key points to note
Youdaoplaceholder0 Lubrication specification : Do not use engine oil with viscosity not meeting the SAE 30 standard, otherwise it may cause carbon deposits in the ring groove.
Youdaoplaceholder0 positioning verification : After the piston is pushed in, it is necessary to check the alignment of the letter/number marks on the connecting rod and the connecting rod journal.
Youdaoplaceholder0 Tool contraindications : If the compressor gets stuck during disengagement, the piston should be retracted to readjust the position of the compression ring. Violent operation is strictly prohibited.
Youdaoplaceholder0 Equipment selection suggestions
Cast iron compressors are suitable for pistons with a diameter of no more than 100mm, while cast steel ones are compatible with large-displacement engines.
Compressors with bidirectional ratchet locking devices can enhance operational stability and reduce the risk of loosening during operation.
If you want to know more, keep reading the other articles on this site!
Please call us if you need such products.
Zhuo Meng Shanghai Auto Co., Ltd. is committed to selling MG&MAXUS auto parts welcome to buy.
