1D;ONE Best Quality Professional Best Quality PISTON Factory manufacturers Factory,Facility & certificates: equipped world-leading Bosch/Siemens machines
1D;ONE Professional Best Quality PISTON Factory manufacturers,Japan NPR technology and 170 qualify trained technicians, CCIP coating, ISO/TSl6949-2002,ISO-2015 approved ect.
1D Best Quality PISTON Factory,Facility & certificates: equipped world-leading Bosch/Siemens machines
The whole piston can be divided into three parts: piston crown, piston head and piston skirt.
The main function of the piston is to bear the combustion pressure in the cylinder and transmit this force to the crankshaft through the piston pin and connecting rod. In addition, the piston forms a combustion chamber together with the cylinder head and cylinder wall.
The piston top is an integral part of the combustion chamber, so it is often made into different shapes. The piston top of gasoline engine mostly adopts flat top or concave top, so as to make the combustion chamber compact, small heat dissipation area and simple manufacturing process. Convex piston is often used in two stroke gasoline engine. The piston crown of diesel engine is often made into various pits.
The piston head is the part above the piston pin seat. The piston ring is installed on the piston head to prevent high-temperature and high-pressure gas from channeling into the crankcase and engine oil from channeling into the combustion chamber; Most of the heat absorbed by the piston top is also transmitted to the cylinder through the piston head, and then transmitted through the cooling medium.
The piston head is machined with several ring grooves for installing the piston ring. The number of piston rings depends on the sealing requirements, which is related to the engine speed and cylinder pressure. The number of rings of high-speed engine is less than that of low-speed engine, and the number of rings of gasoline engine is less than that of diesel engine. General gasoline engine adopts 2 gas rings and 1 oil ring; The diesel engine has 3 gas rings and 1 oil ring; The low-speed diesel engine adopts 3 ~ 4 gas rings. In order to reduce friction loss, the height of the ring belt shall be reduced as far as possible, and the number of rings shall be reduced under the condition of ensuring sealing.
All parts below the piston ring groove are called piston skirts. Its function is to guide the piston to make reciprocating motion in the cylinder and bear side pressure. When the engine is working, the piston will be bent and deformed due to the action of gas pressure in the cylinder. After the piston is heated, due to the large amount of metal at the piston pin, its expansion is greater than that at other places. In addition, the piston will also produce extrusion deformation under the action of side pressure. As a result of the above deformation, the section of the piston skirt becomes an ellipse of the long axis in the direction of the piston pin. In addition, due to the uneven distribution of temperature and mass along the axis of the piston, the thermal expansion of each section is large at the top and small at the bottom
1. It shall have sufficient strength, stiffness, small mass and light weight to ensure the minimum inertial force.
2. Good thermal conductivity, high temperature, high pressure and corrosion resistance, sufficient heat dissipation capacity and small heating area.
3. There should be a small friction coefficient between the piston and the piston wall.
4. When the temperature changes, the change of size and shape shall be small, and the minimum clearance with the cylinder wall shall be maintained.
5. It has small coefficient of thermal expansion and specific gravity, and has good antifriction and thermal strength.
Because the piston of internal combustion engine works under the conditions of high temperature, high pressure and high load, the requirements for the piston are relatively high. Therefore, this paper mainly discusses the classification of internal combustion engine piston.
1. According to the fuel used, it can be divided into gasoline engine piston, diesel engine piston and natural gas piston.
2. According to the materials used to manufacture the piston, it can be divided into cast iron piston, steel piston, aluminum alloy piston and combined piston.
3. According to the process of manufacturing piston blank, it can be divided into gravity casting piston, squeeze casting piston and forging piston.
4. According to the working condition of the piston, it can be divided into two categories: non pressurized piston and pressurized piston.
5. According to the purpose of piston, it can be divided into car piston, truck piston, motorcycle piston, marine piston, tank piston, tractor piston, lawn mower piston, etc.