Green sand casting is the most economical and widely used casting method. 65%-70% of castings in industrialized countries are produced by green sand process. an absolute advantage. The core process of clay sand casting is modeling, and modeling technology is a key factor related to the quality of sand casting products.Classification and characteristics of box molding technology
1. Microseismic compaction modeling
The principle of microseismic compaction modeling is: the sand box is lifted to a certain height by the microseismic mechanism and then falls to collide with the body, so that the falling speed of the molding sand in the sand box becomes a great impact force, so that the molding sand layer is compacted , and then the flat plate is compacted for a second time. The compactness distribution after microseismic compaction shows the characteristics of high hardness on the parting surface and the back of the sand mold, and low hardness in the middle of the sand mold. The microseismic amplitude is 5~25mm, the frequency is 500-1000 times/min, and the specific compaction pressure is about (2-3) kgf/cm². Microseismic compaction molding machines generally use several groups of molding machines equipped with conveyor lines to form a mechanized production line. Because the noise of the microseismic compaction molding machine is greater than 80 decibels, the production efficiency is low, and the labor cost is relatively high.
2. The working principle of high-pressure molding is that the sand is compacted twice by the high-pressure indenter after adding sand by gravity. In terms of the shape of the high-pressure molding press head, there are flat indenters, forming indenters and multi-contact heads. Since the multi-contact type has the characteristic of automatically adjusting the stroke of the indenter according to the shape of the model, it has a wide range of applications. The compaction specific pressure of the high-pressure molding machine is ( 10~ I5 ) kgf/cm², the microseismic frequency is about 500-1000 times/min, and the microseismic amplitude is about 5-25mm. The compactness distribution after high-pressure microseismic compaction shows the characteristics of high hardness on the parting surface and the back of the sand mold, and low hardness in the middle of the sand mold. If the sand mold is relatively thin, it will exist, the sand mold is difficult to exhaust, the sand mold rebounds greatly, and it is easy to produce defects such as sand inclusion.
3. The principle of static pressure molding is to use compressed air to instantly pressurize the sand mold. The compressed air flows from the back of the sand mold through the molding sand to the pattern, and is discharged through the exhaust plug on the pattern to complete the air pre-compacting. The second process is used to compact the sand mold. For final compaction, the specific compaction pressure is high pressure (10~12) kgf/cm², the pressure required for air pre-compacting is greater than 4kgf/cm², and the template needs to be exhausted to complete the air pre-compacting after static pressure molding. Exhaust plugs with 1% to 2% of the sand mold area should be opened on the template.
Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of Green Sand Molding Line,Self-hardening sand molding line,foundry machines,Sand molding machine,Sand casting equipment,sand mixer,GS high efficiency rotary mixer,Resin sand mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,sand casting molding machine,sand reclamation equipment，foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.
