Casting die and casting method of long-cylindrical shell iron casting with ribbed inner chamber

Abstract

The invention discloses a casting die and a casting method of a long-cylindrical shell iron casting with a ribbed inner chamber. The casting die comprises a lower sandbox, an outer metal die, a wet sand core, a sprue cup and a box pressing iron. The outer metal die is positioned on the box body of the lower sandbox, the wet sand core is positioned on the molding sand of the lower sandbox, the excircle of the wet sand core and the inner wall of the outer metal die form a cavity, the outlet end part of the spiral cross gate of the lower sandbox is positioned in a middle position between the excircle of the wet sand core and the inner wall of the outer metal die, the sprue cup is arranged on the circular straight sprue of the upper end surface of the wet sand core, and the box pressing iron is arranged on the upper end surface of the wet sand core. The inner wall of the outer metal die is coated with a layer of a metal release agent before casting, the outer metal die is preheated to 130-160 DEG C, and molten iron enters from the sprue cup to start casting, and casting is completed when the whole cavity is full of the molten iron; and heat insulation is carried out for 2-2.5 H after the casting, then cooling is carried out, the box is opened, the obtained casting is taken out, the cast gate is removed through a mechanical technology, the casting is transferred to a sand roll and undergoes sand cleaning, and the sand removed casting is manually polished.

Description

Technical field [0001] The invention relates to the technical field of production of nodular cast iron parts, in particular to a casting mold and a casting method for a long-cylinder cast iron part with ribs in an inner cavity. Background technique [0002] At present, all kinds of hydraulic valve sealing rings used in construction machinery, adjusting nuts on automobile reducers, and gasket fastening nuts used on construction machinery are basically processed by turning the inner cavity into a long rib with ribs. The barrel cast iron is cut into ring parts with different thicknesses. The long barrel cast iron with ribs in the cavity is as attached Figure 4 , Attached Figure 5 As shown, the inner wall of the cylinder 7 is evenly distributed with a plurality of protruding ribs 7-1. Such parts are restricted by the working environment, and air holes, shrinkage holes and sand inclusions are not allowed on the parts. [0003] In the actual production, most of the long-tube iron casti...

AI Technical Summary

Problems solved by technology

[0006] The long cylindrical iron castings with ribs in the inner cavity produced by the existing sand casting process have the following problems: since the green sand cylinder and green sand core of the casting mold are molded by sand, when pouring, molten iron is injected from the top of the cavity, The produced castings are prone to porosity, sand inclusion and shrinkage defects, the product failure rate is as high as 40%, and cracks are prone to appear at the joint between the rib and the cylinder

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