Principles for the selection of counterweight casting methods

Heavy industry counterweights are generally classified according to the modeling method, and are customarily divided into ordinary sand counterweights and extra-heavy iron. Common sand weights include three types: green sand, dry sand, and chemically hardened sand. According to different molding materials, special weights can be divided into two categories: one type uses sand and gravel as the main molding materials, such as investment weights, shell-type weights, negative pressure weights, and mud-type weights. Weights, solid counterweights, ceramic counterweights, etc.; one type uses metal as the main casting material, such as metal counterweights, centrifugal counterweights, continuous counterweights, pressure counterweights, low-pressure counterweights, etc. Heavy blocks etc. The heavy industry counterweight process can be divided into three basic parts, namely, counterweight metal preparation, mold preparation and casting processing.

　　The principle of choosing the casting method of counterweight:

　　1 The main reason for the use of sand casting for the counterweight is that sand casting has lower cost than other casting methods, simple production process, and short production cycle. When the wet type cannot meet the requirements, consider using the clay sand surface dry sand type, dry sand type or other sand types. The weight of castings made from clay green sand can range from a few kilograms to dozens of kilograms, while the weight of castings produced by dry clay can reach dozens of tons.

　　2 The casting method of the counterweight should be compatible with the production batch. Low pressure casting, die casting, centrifugal casting and other casting methods are only suitable for mass production due to the expensive equipment and molds.

　　3 The method of counterweight modeling should be suitable for factory conditions.

　　 For example, it also produces large-scale machine bed and other castings. Generally, the core assembly method is used, and the pattern and sand box are not made, and the core is assembled in the pit; while in other factories, the sand box method is used to make the pattern. Different enterprises have different production conditions (including equipment, site, staff quality, etc.), production habits, and accumulated experience. According to these conditions, we should consider what products are suitable for and what products are not suitable (or cannot).

　　4 It is necessary to take into account the precision requirements and cost of castings.

　　 The classification of light industrial counterweights is not clearly defined, and can be roughly divided into two categories. One type is plate processing and forming; the other type is profile processing and forming. The materials mainly include various plates, sheets, round iron, flat iron, square iron, and other profiles.