Basic structure

biographical notes

The engine block is the skeleton of the engine and the installation foundation of various mechanisms and systems of the engine. The main parts of the engine are all installed inside and outside and bear various loads. Therefore, the car body must have sufficient strength and rigidity. Engine cylinder block is mainly composed of cylinder block, cylinder liner, cylinder head and cylinder gasket.

cylinder block

The cylinder block and upper crankcase of water-cooled engine are often cast into a whole, which is called cylinder block-crankcase or cylinder block. The cylinder block is usually made of gray cast iron. The cylindrical cavity in the upper part of the cylinder block is called the cylinder, the lower part is the crankcase supporting the crankshaft, and its inner cavity is the space for the crankshaft to move. Many reinforcing ribs, cooling water jackets and lubricating oil passages are cast in the cylinder block.

The cylinder block should have sufficient strength and rigidity. According to the different installation plane positions of the cylinder block and the oil pan, the cylinder block is usually divided into the following three forms.

1. General cylinder block: characterized in that the installation plane of oil pan is at the same height as the rotation center of crankshaft. The advantages of this cylinder block are small height, light weight, compact structure, convenient processing and convenient disassembly and assembly of crankshaft; But its disadvantages are poor rigidity and strength.

2. Gantry cylinder block: characterized in that the installation plane of oil pan is lower than the rotation center of crankshaft. Its advantages are good strength and rigidity, and it can bear large mechanical load. But its disadvantages are poor manufacturability, heavy structure and difficult processing.

3. Tunnel cylinder block: The main bearing hole of the crankshaft of this type of cylinder block is integral with rolling bearings, and the main bearing hole is larger, and the crankshaft is loaded from the back of the cylinder block. Its advantages are compact structure, good rigidity and strength, but its disadvantages are high machining accuracy, poor manufacturability and inconvenient disassembly and assembly of crankshaft.