For the design of the positioning structure of the water jacket sand core of the cylinder block, many factories producing the cylinder block only adopt the structure of casting the water hole at the cylinder block and cylinder head, that is, the core formed after the extension of the water hole sand core structure at the corresponding part of the water jacket sand core is combined and bonded with the core seat made on the top cover sand core. The core head formed by the medium and large sand holes at both ends of the water jacket sand core in the length direction is directly in contact with the sand mold. In this way, the water jacket sand core, the top cover sand core and the lower mold cavity have a mutual positioning relationship. This not only complicates the positioning structure of water jacket sand core, but also reduces the reliability of its positioning structure. Moreover, this positioning structure also makes the combination of water jacket sand core and top cover sand core more difficult to operate and less reliable in the process of handling, core assembly and core lowering.
For the positioning structure of the water jacket sand core of the cylinder block, our factory not only adopts the above-mentioned bonding method of the core head of the water hole, but also adopts the two ends Φ The core head structure of 50 sand hole is enlarged and the appropriate core head seat positioning structure is made at the corresponding positions at both ends of the top cover sand core, so that the gravity of the water jacket sand core mainly acts on both ends in the process of handling, core assembly and core lowering Φ 50 sand production hole structure. In this way, it not only facilitates the handling, core assembly, core lowering and other operations, reduces the damage rate of the sand core, but also simplifies the positioning relationship of the water jacket sand core, that is, the positioning of the water jacket sand core is only related to the top cover sand core, rather than directly contacting with the appearance, which improves the dimensional accuracy.