When constructing an internal combustion engine, engineers always encounter the same problem-the bottom of the piston and the cylinder cannot be the same diameter. The oil shall not penetrate into the combustion chamber. A massive piston wedge in a cylinder, even if it is slightly smaller than the diameter, but a narrow flexible ring fitted with a movable lock. Application of the rings proved to be an ideal compromise. Types of piston rings
Types of piston rings
The piston rings are of two types-compression and oil.
Compresession rings are used to create pressure in the combustion chamber.
The design of the engine provides a small gap between the walls of the cylinder and the piston. The pattern does not allow the necessary pressure to be created in the combustion chamber, as the expanding gases would inevitably flow into the engine's crankcase. This was accomplished with the assistance of compression rings. These are steel thin rings with incisions. The cut is called a lock, because it allows a resilient circle to shrink and clench within strictly defined limits without, at the same time, derelating the piston. In order for the rings to be freely compressed, the outer surface of the cylinder is removed from the ring groovy groovy groans.
The rings are made of elastic steel. In fact, the ring is a kind of spring. They are in a depressed condition and, at the expense of this, are closely attached to the cylinder wall. As the rings are stagnating during the operation, the light density does not fall, at least until the wear reaches a critical point.
piston rings in the piston hull
The majority of pistons in modern engines are equipped with three rings. Two upper rings, low-session, low-winged.
Compresessional loops, even if the two rings are located one above the other, cannot completely eliminate the breakthrough of the combustion chamber.
The problem of a breakthrough is trying to solve it in a number of ways. For example, when the rings are mounted on the factory floor, the rings are arranged so that the locks do not lie above the other. It's best to make them 180 degrees, so they can "look" in different directions. In fact, this condition must be observed during the overhaul of the engine.
Warming helps to extend the life of any engine, whatever the manufacturer says. The rings continue to be rubdown against the wall of the cylinders, such as the structure of the IVS
During the cycle of the ring, the rings are attached to the mirror of the cylinders, and the gaps are practically eliminated. This is due in no small part to the existence of the engine run-in regime. If the manufacturer prescribes such a mode in the service book, it should be followed by the responsible owner with the engine run-in, the more reliable "will lie" on the mirror of the cylinders, and the longer the engine will be.
The hoisting ring performs a simpler function, removing the excess oil that falls on the top of the cylinder from the bottom. In the lower part of the crankcase, there is a real oil mist that occurs when the wheel rotates. The scattered oil of the cylinder sashes the walls of the cylinder, allowing the pistons to slip freely upwards and downwards, but it is not possible to allow it to enter the combustion chamber. Under the influence of the temperature it will be partially burned, partly buried, i.e. it will settle in the form of a dense soar on the valves, the cylinder wall, the surface of the piston, the word everywhere. If this happens, the engine will be out of order very quickly. By the way, the expression "rings" has a direct relationship to the law. The oil flashes between the cylinder wall and the worn oil-ring, the oil burns, and the unburned rest of the cylinder thickly clings the compression rings which end up decompressing and remain in a tight condition.
Operation of piston rings
In the cylinder process, all rings lose their elasticity. This process is uneven and begins in the castle area. At the location of the lock (in the gap) the contact with the cylinder wall is gradually deteriorated and overheating occurs. In addition, the rings are subject to high wear and tear when they are dizzy to high speeds.
In compression rings, the shape of the lock can be a step, a slash, or a rectangular lock. The most common rings appear with a rectangular incision. These rings do not cost the manufacturer, but they have the most poor sealing properties.
Materials for piston rings
The most common material for the manufacture of piston rings is a highly durable grey cast iron.
The cast of the cast iron preserves the strength and strength throughout the life of the service. This material has shown itself to the best side in the high friction-rings of cast iron have not been erased for a long time. With the strength of the ring material, it is well and equally applied, and closely attached to the mirror of the cylinder.
The apparent simple shape of the piston ring is difficult to produce
To increase the thermostability of the rings in the grey cast iron, alloying additives are added: nickel, chrome and other such substances.
The technology of piston rings
The seemingly simple shape of the piston ring process poses a number of difficulties.
They are related above all to increased accuracy requirements and to the shape of the ring. In addition, they make an incision that complicates the technology of production.
It is important to withstand the outer surface roughness of 2.5 um. Having such a rough surface, the ring is processed more quickly against the wall of the cylinder (mirror). If you flick the outer surface, the tition will be long, and the engine will have to be rolled over for tens of thousands of kilometers.
During the manufacture of piston rings, cracks and other defects on their surface shall not be allowed.
In the process of making piston rings it is important to make them perfectly level so that the pressure on the edges of the piston is evenly distributed.
The magic rings are taken in forms, then the metal is tempered, "released" and cut out the lock. When the surface is cooled by the endurance of the material, the ring shall be subjected to a polishing to make the desired shape.
A porous chrome or molybdenum layer is applied to the working surface of the oil rings to increase the durability and to protect against corrosion.
