What are the manufacturing processes of automobile mold […]
What are the manufacturing processes of automobile molds in the production process
Casting is a production method in which molten metal is poured into the cavity of a mold and cooled and solidified to obtain a Auto Plastic Parts Mold. In the process of automobile manufacturing, there are many parts made of cast iron, which account for about 10% of the total vehicle weight, such as cylinder block, transmission case, steering gear housing, rear axle housing, brake drum, various brackets, etc. . Sand molds are usually used to manufacture iron castings. The raw material of the sand mold is mainly sand, mixed with binder and water. The sand material must have a certain adhesive strength so that it can be molded into the required shape and can withstand the erosion of hot molten iron without collapse. In order to mold a cavity in the sand mold that matches the shape of the casting, wood must be used to make a model, called a wooden mold. The volume of the hot molten iron will shrink after cooling. Therefore, the size of the wooden mold needs to be increased according to the shrinkage rate on the basis of the original size of the casting, and the surface that needs to be cut is thickened accordingly. Hollow castings need to be made into sand cores and corresponding core wooden molds (core boxes). With wooden molds, cavity sand molds can be turned (casting is also called "foundation"). When making sand molds, it is necessary to consider how to separate the upper and lower flasks in order to take out the wooden mold, and also consider where the molten iron flows in and how to fill the cavity in order to obtain high-quality castings. After the sand mold is made, it can be poured, that is, the molten iron is poured into the cavity of the sand mold. When pouring, the temperature of molten iron is 1250-1350 degrees, and the temperature is higher during smelting.
In the automobile manufacturing process, forging is widely used. Forging is divided into free forging and model forging. Free forging is a processing method in which a metal blank is placed on an anvil and subjected to impact or pressure (known as "ironing"). The blanks of automobile gears and shafts are processed by free forging. Model forging is a processing method in which metal blanks are placed in the cavity of a forging die and subjected to impact or pressure. Model forging is a bit like the process of pressing dough into a biscuit shape in a mold. Compared with free forging, the shape of the workpiece produced by die forging is more complicated and the size is more accurate. Typical examples of automobile die forgings are: engine connecting rods and crankshafts, automobile front axles, steering knuckles, etc.
Cold stamping or sheet metal stamping is a processing method in which sheet metal is cut or formed under pressure in a die. Daily necessities, female aluminum pots, lunch boxes, washbasins, etc. are made by cold stamping processing methods. For example, to make a lunch box, you first need to cut out a rectangular blank with 4 rounded corners (known as "blanking" by experts), and then use a punch to press this blank into a concave mold to form (known as "drawing" by experts) ). In the deep drawing process, the flat sheet material becomes a box shape, and its four sides are vertically bent upwards, and the material at the four corners is accumulated and wrinkles can be seen. Auto parts processed by cold stamping include: engine oil pan, brake bottom plate, car frame and most body parts. These parts are generally formed through processes such as blanking, punching, deep drawing, bending, flanging, and trimming. In order to manufacture cold stamped parts, a die must be prepared. The die is usually divided into two pieces, one of which is installed above the press and can slide up and down, and the other is installed under the press and fixed. During production, the blank is placed between the two punching dies. When the upper and lower dies are closed, the stamping process is completed. The productivity of stamping processing is high, and parts with complex shapes and high precision can be manufactured.