Howo Diesel Engine Parts VG1560037011 Piston
Howo Diesel Engine Parts VG1560037011 Piston Howo Diesel Engine Parts VG1560037011 Piston Piston effect The function of the piston is to form a combustion chamber together with the cylinder head and the cylinder to bear the gas pressure and transmit the pressure to the crankshaft through the...Send InquiryChat Now
Howo Diesel Engine Parts VG1560037011 Piston
Howo Diesel Engine Parts VG1560037011 Piston Piston effect
The function of the piston is to form a combustion chamber together with the cylinder head and the cylinder to bear the gas pressure and transmit the pressure to the crankshaft through the piston pin and the connecting rod so as to push the crankshaft to rotate; the key part of the engine doing work is reciprocating motion of the piston, Complete the engine intake, compression, expansion work and exhaust process. The two-stroke gasoline engine pistons commonly used in motorcycles also have the effect of controlling intake, scavenging, exhaust and tissue combustion.
Piston structural features
1, the piston structure: Pistons mainly by the piston top, ring, skirt, pin seat composition.
(a) The top of the piston top piston, together with the cylinder wall and cylinder head, forms the combustion chamber whose shape depends on the type of combustion chamber. The top of the four-stroke piston corresponds to the valve part of the common pit, is designed to avoid the valve.
(b) The piston annulus consists of a land bank and a ring groove, and is the main seal area of the piston group. At the same time, most of the high heat absorbed by the top of the piston is also transmitted to the piston ring and then to the cylinder wall, dissipating through the cylinder fins or coolant.
(c) Piston Skirt Piston Skirt refers to the lowermost cylindrical portion of the annular groove to the underside of the piston, which acts as a guide and a lateral pressure for reciprocation of the piston in the cylinder. In order to adapt to thermal deformation, the piston cylinder cross-section is oval, in the direction of the piston is tapered, or barrel.
(d) The pedestal is located above the center of the skirt. Its function is to install the piston pin and withstand the gas pressure from the top of the piston. It is passed on to the piston pin and then to the connecting rod. Pin holes at both ends of the snap ring groove, used to install the piston pin retaining ring (referred to as snap ring) to prevent the piston pin axial movement.
2, two-stroke piston: two-stroke piston multi-use convex spherical to meet the needs of the scavenging process. When the piston is at top dead center, the skirt must cover the vent so that its skirt is long and has a window cutout to allow the cylinder block to form an intake or scavenge passage. In the meantime, a locating pin with a diameter of 1.5-2mm is installed in the piston ring groove to limit the circumferential movement of the piston ring, so as to avoid pulling the inner surface of the cylinder body or breaking the ring itself when the piston ring opening is turned to the gas port position on the cylinder body .
Due to the particularity of the two-stroke engine, the lubricating oil participating in combustion can become carbon molecules accumulated in the ring groove of the piston under high temperature and high pressure, which can easily cause the piston ring to stick to lose its sealing effect and cause serious Under high temperature gas channeling and other malignant failures. Therefore, the first piston ring groove, was designed as a single wedge (and some piston two ring grooves are used single wedge).
Piston assembly (combination) is composed of piston, piston ring, piston pin, piston pin gear ring and so on. Are optimized combination
Piston assembly method: When assembling the piston, the selected piston first install a piston pin retainer, and then the piston pin coated with lubricating oil, gently knock it into the piston pin hole, and should extend the piston pin hole The inner end surface of about 2mm, so that the rest of the gap just put the connecting rod small head. Then insert the protruding piston pin into the small hole of the connecting rod, align the piston and gently tap the piston pin until the snap ring groove is completely exposed. Do not beating too hard, so as not to pre-set the piston pin retainer damage, and finally fitted with another piston pin retainer. Piston and piston pin with the transition fit, can be used hot assembly. Before assembly, should check the piston pin and piston pin hole with the situation, to hand push the pin into the pin hole 1/3, and then gently hammer into the appropriate. Assembly, the first piston into the oil heated to 100 ℃ ~ 120 ℃, and insulation for a certain period of time, and then remove the piston and connecting rod small hole aligned, the rapid insertion of the piston pin. When installing the piston, the opening position of the piston ring must not be aligned with the exhaust port and the scavenging port of the cylinder. Otherwise, the piston opening may collide with the exhaust port or scavenging port of the cylinder to cause damage. General provisions, the piston on the top of the arrow or mark should be aligned exhaust direction, in order to avoid wrong, remember to disassemble the piston assembly direction. Some motorcycle engine piston top groove milling, the purpose is to avoid collision with the relief valve, assembly, the groove should be aligned with the position of the pressure relief valve, otherwise, the pressure relief valve and the piston will be damaged.