Exhaust unit and method for low-pressure casting with metal mold

Abstract

The invention relates to an exhaust unit and method for low-pressure casting with a metal mold. The exhaust unit comprises a body; the body is internally provided with a cavity used for exhausting; a high temperature resistant liquid-isolating breathable layer made of ceramic fiber is arranged within the cavity; a fixture is arranged above the high temperature resistant liquid-isolating breathable layer; an exhaust vent is provided below the high temperature resistant liquid-isolating breathable layer and comprises a conical hole and a conical-holed protrusion communicated with each other; the small end of the conical hole is communicated with the conical-holed protrusion which is tubular in shape; the conical-holed protrusion is provided on one side close to the high temperature resistant liquid-isolating breathable layer. The exhaust unit has the advantages that demolding is easy, exhausting is effective, exhausting condition of a casting product and changes in gas-forming amount of casting material are conveniently directly detected, and the exhaust unit is economical and applicable, simple to operate, environment friendly and pollution free. The exhaust method has the advantages the process is simple, the efficiency is high, a workpiece is effectively avoided being voided or material short, and the product yield is up to more than 99.9%.

Description

Technical field [0001] The invention relates to an exhaust device and an exhaust method, which is suitable for casting technology, particularly suitable for metal mold precision low-pressure casting. Specifically, it relates to a metal mold low-pressure casting exhaust device and an exhaust method, belonging to the technical field of casting . Background technique [0002] Metal mold low pressure casting technology has been widely used in my country, especially in the cast aluminum industry. [0003] In the casting process, the exhaust in the casting cavity is one of the key links. A poor exhaust system will hold the cavity in the cavity. In severe cases, it will also generate back pressure, resulting in the molten metal not being able to completely fill the cavity, resulting in casting defects or scrap. [0004] There are a variety of exhaust methods in the industry, which can be roughly divided into: groove type, slot type and mesh type. However, the above-mentioned methods are e...

AI Technical Summary

Problems solved by technology

However, the copper screen is not easy to fix. Because the liquid aluminum will be embedded during casting, the copper screen will remain on the casting after each casting and cannot be removed for reuse. A new copper screen must be replaced before each casting , not only cumbersome, but also wasteful

[0006] The Chinese patent with the application number 201310220519.6 discloses a metal type low-pressure casting mold, which includes a bottom plate, left and right molds, sand cores, keels, bolts and an upper mold. The inside is a Huff structure, and there are vent holes at the connection. The upper mold is set on

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