1. Noun interpretation block material
by the engine cylinder block and cylinder head of two parts, connected to each other by means of bolts.
block material should have sufficient strength, good castability and machinability, and the price is low, the common block material is cast iron, alloy cast iron. Cast iron has many inherent deficiencies, such as large weight, poor heat dissipation, higher coefficient of friction and the like. Therefore, engine manufacturers are looking for a more suitable material, such as iron density than aluminum.
using an aluminum alloy cylinder now more and more common, because light weight aluminum alloy cylinder, good thermal conductivity, the capacity of the coolant can be reduced. After starting, the cylinder rapidly reaches its operating temperature, and the thermal expansion coefficient of aluminum pistons and exactly the same, a small gap variation after heating, can reduce the impact of noise and oil consumption. And the head and thermal expansion of the same alloy, cold working can reduce thermal stress generated by the impact. Similarly there are also disadvantages of aluminum, it is easy and the water produced during combustion chemical reaction, corrosion resistance and less iron block.
a water-cooled cylinder and a cylinder liner cylinder engine has three structural types: linerless, dry cylinder liner, cylinder cover. Linerless cylinder: cylinder bore formed integrally with the cylinder, the inner surface of the piston is not in contact with the casement, the majority of iron cylinder gasoline engine with this type of simple structure, less processing surface, the rigidity of the cylinder are better.