Home » Science and Mathematics » Piston Type and materials

Piston Type and materials

  • Piston Type and materials used in engines
  • Used materials
  • It is usually made from gray cast iron, from soft cast steel, from aluminum alloy, or from some chrome-nickel-doped steels and rolled iron, as in some diesel engines. The pistons made of gray cast iron are resistant to abrasion, but when gray cast iron joins steel in small amounts, cast mild steel is obtained, which is preferred for piston construction due to its strength, abrasion resistance and relatively lightness.

 

  • Cast iron and steel casting pistons are preferred on heavy-duty engines used mostly on tractors and road machines. Because these engines change sudden speeds and suddenly there is no transition to high speeds, the heavy weight of the piston in these types of engines is not a significant drawback. Aluminum alloy pistons, however, have a high ability to conduct heat, so they pass through the heat without holding them in place, and therefore operate at lower temperatures.

 

  • Since the expansion coefficient of pistons made of aluminum alloy is high, this type of pistons is given more space between the cylinder and the piston than the cast iron pistons. However, aluminum alloy pistons are provided with some special shapes so that the engine can run without any piston knocking while operating at engine regime temperature without piston knocking while the engine is cold. The pistons made of aluminum alloy are subjected to thermal treatment by some companies and then electrolytic (anodic) processes are applied.

 

  • As a result of this process, a thin layer of aluminum oxide layer with a thickness of 0.0005 mm is formed on the piston surface. This layer enhances the resistance of the piston against wear and provides better lubrication of the piston surface. Some other companies, such as tin or similar soft materials, use the electrolytic surface of the piston surface to serve as a lubricant on the piston surface, in particular to shorten the piston’s first mixing cycle.

 

  • Piston Structure
  • Piston Structure

     

     

     

     

    Piston Structure

 

  • Piston heads are generally flat, curved, and in some diesel engines are made in the form of a bowl (concave). In some V8 engines, the piston plugs are hollowed out to prevent the piston head from hitting the valve heads. By reinforcing the piston head, reinforcing arms are built into the inner part of the piston to increase resistance to burnt gas pressure. These reinforcement arms also help to convey the heat from the piston head to the cylinder wall and to the cooling water. In some heavy-duty engines, the local steel reinforcements are installed to protect the piston head and seat belts from high pressure and heat. The piston pin nests just below the start of the piston skirt rest on the piston pin. Often the material around the piston pin chamber is discharged in the pistons, thereby reducing both the weight of the piston and the expansion of the piston in the pin direction. At the beginning of the piston there are knapsacks. Generally, the petrol engine pistons have two compressions, two oil straps. In some engines, this second oil line is located on the plunger.

 

  • If the compression plumes in the platen are flat, there are oil drain holes in the oil platters. Some of the pistons also have a channel in the first set of pistons, which is called a heat dam. This channel prevents the overheating of the piston head from moving into the blinds, collecting the carbon particles and making them harmless. Generally, to prevent deformation of the piston skirt, a reinforcing balance strip is made on the inside of the skirt during casting. In the piston made of aluminum alloy, the material in the direction of the piston pin axis is discharged as much as possible and the dimension is reduced so that the piston can be expanded and contracted in the direction of the pin during operation. In some motors, the piston rod is screwed to the 1.6mm compression-time bearing surface side or the work-piece bearing surface side from the axis of the pivot pin to prevent the piston skirt knock in the cylinder, although the piston pin nests are usually on the axis of symmetry of the piston.

 

  • Piston Types
  • In gasoline engines, flat skirt, flat diagonal razor, T razor, U razor and auto thermic pistons are used. Bottom of page you can found piston types image  (Flat head, Recessed head, Concave head, Dome head)
Piston Type and materials
Author: wik Date: 6:41 pm
Science and Mathematics, Technology


Wik's Random Content