Abstract: Disclosed is an automatic welding system for cylinder block recycling. The system welds a cylinder head seating part, an upper cylinder liner assembly part, a lower cylinder liner assembly part and a main bearing assembly part, to enable a cylinder block of an engine to be recycled. The system comprises a supporting section for rotatably supporting the cylinder block; a driving section installed on the supporting section for rotating the cylinder block; a welding section for welding the cylinder head seating part, the upper cylinder liner assembly part, the lower cylinder liner assembly part and the main bearing assembly part of the cylinder block; a moving section for moving the welding section along a lengthwise direction of the cylinder block to a welding execution position; and a central controlling section for controlling the driving section, welding section and the moving section.

Abstract: A cylinder liner is described which comprise a body and an oil pocket which is filled with lubrication oil. The body is made of iron cart. The oil pocket is formed on inner surface of the body and includes a plurality of recess rows which are arranged, in the diagonal direction, on the inner surface of the body. Each of recesses is reverse-dotted on the inner surface of the body by a knurling process.