Manufacturing method of brake drum

Abstract

The invention discloses a manufacturing method of a brake drum. The manufacturing method mainly comprises the following steps: respectively manufacturing an upper mould shell model, a lower mould shell model and a sprue cup shell model on a core shooting machine, then assembling to form an integral film-coated sand shell model; placing a sand box on a ramming platform; putting dried sand into the sand box, and ramming to form a bottom sand layer; placing the assembled film-coated sand shell model into the sand box, putting the dried sand into the sand box, and ramming; coating a back film, vacuumizing; and pouring, releasing a negative pressure, opening the box, drawing and removing a casting head of a casting of the brake drum. The manufacturing method achieves the characteristic of combining advantages of two processes by combining a V-method casting process and a film-coated sand shell model casting process.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a method for manufacturing a brake drum. Background technique [0002] At present, the main casting processes of automobile brake drum blanks are: [0003] 1. V-method casting process: V-method casting uses a plastic film to seal the sand box, and the air in the mold is drawn out by a vacuum pumping system. There is a pressure difference between the inside and outside of the mold to make the dry sand dense and form a cavity with a certain strength. After setting the core, closing the box, pouring and evacuating the casting, the casting is solidified, and the negative pressure is released, and the molding sand is then collapsed to obtain the casting. [0004] The surface of the casting produced by this process is smooth, the outline is clear, and the material is uniform. The biggest advantage different from the traditional sand casting is that no binder is used, which greatly re...

AI Technical Summary

Problems solved by technology

[0012] 1. Disadvantages of V-method casting process: In the actual production process, V-method casting needs to spray paint during the molding process. There is a certain amount of dust during spraying, and when the spraying is not in place, it is easy to cause sand sticking, sand inclusion, sand collapse, etc. Casting defects, the box closing process has very strict requirements on the management of sand boxes and mold plates, and is responsible for the wrong box defects that are prone to occur in the box closing process

[0013] 2. Disadvantages of coated sand shell mold casting process: The coated sand shell mold casting process is affected by the strength of the shell mold, and is suitable for the production of castings with small contour size and thin wall thickness

[0014] 3. Disadvantages of iron mold sand-coated casting process: when iron mold sand-coated production, the sand mold is thermally cured by the hot core box method, which requires a certain temperature and time, which affects the production efficiency of iron mold sand-coated, and affects the production of large-scale products It is not suitable; the molding machine covered with sand for iron mold can be said to be a hot core box core shooter, so it is not suitable for the production of large and complex parts.

[0015] 4. Disadvantages of clay wet sand casting process: when mixing sand, the viscous clay slurry should be coated on the surface of the sand grains, and high-power sand mixing equipment with kneading effect is required, otherwise it is impossible to obtain good quality molding sand; After mixing well, it has quite high strength. The molding sand is not easy to flow and hard to pound when molding. It is laborious and requires certain skills when molding by hand. When molding by machine, the equipment is complicated and huge; the rigidity of the mold is not high, and the hardness of the casting Dimensional accuracy is poor; castings are prone to defects such as sand washing, sand inclusions, and pores

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