Method for casting brake bottom plate blank for automobile, and casting mold used by method

Abstract

The invention discloses a method for casting a brake bottom plate blank for an automobile. The method is suitable for manufacturing of brake bottom plate blanks with various specifications. The method comprises the following steps of: pouring ZG270-500 molten steel of which the temperature is 20 to 100 DEG C higher than that of a liquid phase line into a pressure chamber to reach the lower edges of ingates; filling the molten steel into a mould cavity under the action of the pressure of 1 to 9MPa; pressurizing to 20 to 150MPa, and maintaining pressure until molten metal is completely solidified; and opening a mould and taking a workpiece, and performing annealing treatment by using waste heat of the workpiece to obtain the brake bottom plate blank. The cores of a casting mold are arrangedon a lower type so as to realize demoulding; an upper type is provided with through holes to exert the function of fixing the cores and discharging air; the inner cavity of the pressure chamber is circular, the shape and size of the port of the pressure chamber are the same as those of the axle hole of a brake bottom plate; and the port of the pressure chamber is provided with 2 to 4 ingates which are communicated with the chamber of the axle hole. In the method, a dead head is saved and the utilization rate of a material is high; the dust pollution of molding sand is avoided; the machining allowance of the obtained blank is low; and the waste heat is used for heat treatment, and the energy is saved.

Description

technical field [0001] The invention relates to a casting method of a brake base blank for automobiles, which is suitable for the manufacture of brake base blanks of various specifications. Background technique [0002] The brake base plate is an important part of the car brake, each car needs 2 pieces, and the market demand is relatively large. In the prior art, the material of the brake base plate is cast steel or ductile iron, and the structure of the brake base plate is relatively special. There is a circular or square hole in the middle, which is used to be installed on the axle. There are pin holes at both ends, which are used to install positioning pins or support pins. Its shape is relatively complex and its mechanical properties are high. At present, the blanks of the brake base plate are produced by sand casting or precision casting. [0003] In the existing casting technology, no matter sand casting or precision casting, a large amount of molding sand is require...

AI Technical Summary

Problems solved by technology

The use of such a large amount of molding sand has caused serious dust pollution and even silicosis in the process of processing and recycling

In addition, the wall thickness of the brake bottom plate is uneven, and it is easy to produce shrinkage porosity or shrinkage cavity defects if it is produced by existing sand casting

In order to supplement the liquid shrinkage and solidification shrinkage of the metal and obtain dense castings, a large riser must be used, because the weight of the riser is equivalent to the weight of the workpiece, resulting in a process yield of only 55-70%.

The cutting and remelting of these risers also brings loss of material, waste of energy and repeated investment of labor

Even the workpiece is often scrapped due to defects such as shrinkage cavity, shrinkage porosity, and trachoma

Images