With the increasingly fierce market competition, the quality requirements of engine products are higher and higher, especially the requirements of high quality and fast delivery. Traditional casting is difficult to meet the requirements of high quality and fast delivery in the face of cylinder block. The cylinder block casting researched by ZHY casting is the core component of gas engine. Its overall appearance and inner cavity are in the shape of “V”, which is composed of cylinder mouth, water cavity and cam cavity. As the backbone structure of the engine, the casting has very high quality requirements. Through the innovative research on 3D printing process of gas engine cylinder block, an efficient and stable 3D printing process for cylinder block casting was successfully developed.
Casting dimension 1 700 mm × 1 000 mm × The structure of the casting is shown in Fig. 1.
The casting material is gray cast iron, according to ASTM a247-2016 “standard test method for evaluating graphite microstructure in Iron Castings”, the graphite is type A, the size is 4 ~ 5, the volume fraction of pearlite in the matrix structure is ≥ 90%, the tensile strength of the body is ≥ 258 MPa, and the hardness is 170 ~ 241 Hb; RT test level is level II in key area, and no leakage is found after 30 min of 1 MPa water pressure test.
The practice shows that the production efficiency, product quality and production difficulty of V-type gas engine cylinder block castings produced by 3D printing sand core technology are improved, which can meet the high-efficiency production of this kind of cylinder block castings.