Method for low-pressure casting of aluminium alloy patterned ring by using low-pressure casting mould

Abstract

The invention discloses a method for low-pressure casting of an aluminium alloy patterned ring by using a low-pressure casting mould. The method is conducted by the following steps of: A, sequentially pre-heating an outer mould, a plaster mould core and a pouring gate to the temperatures of 350 DEG C, 110 DEG C and 400 DEG C, respectively; B, mould filling process, that is, pouring aluminium liquid into a mould cavity from the pouring gate with the pouring temperature being 700 DEG C, filling pressure being 0.3bar and filling speed being 0.007bar / s, maintaining the pressure at 1.0bar for 2000seconds within 50-60 seconds after mould filling; C, filling cooling water into a cooling liquid runner of the outer mould from a water inlet while maintaining the pressure, enabling the cooling water to flow out of a water outlet after going around the outer mold in the runner for a circle, wherein the flow of the cooling water is 150-200cm<3> / s and the time of duration is 500-600 seconds; and D, promoting a casting piece to cool to the temperature of 550 DEG C within 300 seconds by the cooling water taking away heat, and pressure relief and demould are conducted when the temperature of the casting piece is cooled to the temperature of 350 DEG C.

Description

Technical field: [0001] The invention relates to a low-pressure casting method using an aluminum alloy pattern ring low-pressure casting mold. Background technique: [0002] The aluminum alloy tread ring is an important part of the tire mold for vulcanization forming tire tread. The processing methods of this part are generally used at home and abroad. There are mainly the following three types: [0003] 1. Carving process: suitable for truck tire moulds; [0004] 2. Electrocorrosion process: suitable for truck tire and passenger tire molds; [0005] 3. Aluminum alloy casting process: suitable for passenger tire molds. [0006] Due to the requirements of safety, comfort and aesthetics, the pattern design of passenger tires is more complicated than that of truck tires, and the shape accuracy and dimensional accuracy of the pattern are required to be high. Therefore, the pattern ring processing of the mold mainly adopts the aluminum alloy casting process. [0007] At prese...

AI Technical Summary

Problems solved by technology

Therefore, when the outer mold and runner with the same parameters are poured into castings with a wall thickness of more than 80mm, due to the heavy weight of molten aluminum, relatively large heat capacity, and too long cooling time, the condensation sequence of the casting will change, and point F of the runner will first Cooling at the E point of the casting cuts off the feeding channel, resulting in insufficient feeding at the E point of the casting, resulting in porosity and shrinkage defects, and in severe cases, it will be scrapped

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