Coremaking Machine
A coremaking machine is a device used in a foundry to create metal cores, which are cylinders or other shapes used to form the inner structure of a mold. The core is then used in the sand casting process, which is basically a method of forming metal parts by pouring molten metal into a cavity created by a sand-mold and then allowing the metal to cool. Cores are made from a range of materials, such as sand or ceramic, and allow for more complicated shapes and designs than otherwise impossible with traditional casting techniques.
A coremaking machine usually comprises two parts; the first part is a plunger that is used to press the core material into the mold cavity. This plunger is usually operated by a hydraulic or pneumatic system, while the second part is a extraction unit which is used to remove the finished core from the machine. The plunger is connected to a plunger motion system that provides the power and motion required to move the plunger through the coremaking process.
The plunger is usually operated by a combination of a linear double-acting cylinder and a planetary gearbox. The double-acting cylinder is used to provide the force required for movement, while the planetary gearbox is used to control the speed at which the plunger is operated. The plunger motion system also contains a pressure transducer which is used to monitor and regulate the pressure being exerted on the plunger. The force and speed of the plunger are both adjustable and dependant on the type and size of the core being made.
Once the plunger has been moved to the necessary starting position, a mold core is placed into the center of the cavity and the plunger is actuated. The plunger compresses the core material into the cavity and helps to shape the desired core. Depending on the material used, the core may be deposited into the cavity in layers, which may be cut into the wanted shape as each layer is added. The plunger can then be moved back and forth to even out the shape and to ensure that the most accurate form possible is achieved. This process must be repeated for each core that is to be made.
Once the core making process is finished, the plunger is then retracted and the core is extracted from the machine using the extraction unit. The extraction unit is usually a mechanical device that uses air pressure, a vacuum or a combination of both to remove the core from the machine. The core is then ready to be used in the sand casting process.
Coremaking machines are an essential part of the sand casting process as they are able to produce cores which are complex shapes and have various wall thickness, which could not have been achieved manually. They are becoming increasingly popular due to the high degree of accuracy and control that can be achieved and the range of shapes that can be created.
