The piston is a cylinder open at its bottom base is closed at the top and subject to the rod at its middle. The movement of the piston is up and down inside the cylinder, compressing the mixture, the combustion pressure transmitted to the crankshaft through the connecting rod, the output power from the combustion gases in the exhaust stroke and produces a vacuum in the cylinder that “sucks” the mixture in the intake stroke.
The piston, which at first glance may seem simpler parts, has been and is one that has required further study. Should be light, so that minimizes inertia loads, but in turn must be rigid enough to withstand the heat and pressure developed inside the combustion chamber l.
Begin with the materials. The pistons of the engines used as main element aluminum, a metal with large qualities. In the manufacture of pistons, aluminum are added other elements to obtain appropriate formulas that provide relevant characteristics with the type and engine application. These alloys are those which permit a high quality product such as the Sealed Power pistons.
Cast aluminum pistons (Suffix P, NP)
One of the oldest processes and still in effect, is the casting of aluminum ingots in large crucibles (where metals are heated until they melt or go from solid to liquid) that is then poured into molds in water-cooled systems special. Later, they began the machining process, carried out by different machines controlled by computers and finally go through a series of thermal processes that give the properties required by the original equipment manufacturers. These same Pistons Sealed Power brand are those vehicles leaving the factory and are the same ones offered in the repuesteras as spare parts.
Figure 1
Pressure forged pistons (Suffix F)
In this process, use pieces of aluminum alloy bars cut to size and subjected to pressures up to 3000 tons of force, in the forging dies are exactly the dimensions of the piston and ring grooves with precision machined to provide optimal quality and reliability in the use of these, in other daily use as heavy duty and even car engines competencies (Figure 1).
Figure 2
Hypereutectic pistons (prefix H)
These pistons are manufactured with modern systems of higher metallurgical technology in which new formulations are used for adding a larger amount of silicon, achieving a uniform molecular expansion used in their composition. This manufacturing technique provides these pistons special features such as support increased strength, endurance and control of the expansion at high temperatures, reducing the risk of the piston to stick or grip on the cylinder, the life is higher since the grooves of the rings and piston pin hole are more durable, plus can be installed in new engines and motors also are used in previous years. This particular technology is imposed Sealed Power pistons especially for new generations of high-compression engines. By using pistons with code “H” will be reliable repair (Figure 2).
Figure 3
Coating piston (suffix C)
The first minutes of operation of a new or repaired are critical to engine life. Brand Pistons Sealed Power have been at the forefront of technology in the lining of the piston skirts. Initially we used the tin (this gives you an opaque figure 3) but be harmful to health has been eliminated by the manufacturers of pistons. In place is using the new anti-friction coating composed of molybdenum and graphite on the slopes (giving a black, figure 4).
Figure 4
This process patented by Sealed Power extends the life of the engines that use it, avoid scratching the pistons helps prevent damage from inadequate lubrication and improves the sealing of the pistons.They are also used uncoated pistons that look bright color to be machined aluminum (Figure 1).
more terms:
- types of pistons
- types of piston