Good mechanical properties fabrication drill bushing guide bush
Bushing can be divided into many types, common ones are: machine copper roller and copper bearing, which are important components of machinery. How their production process directly affects product quality? Their production process can be divided into precision casting, centrifugal casting sand mold casting, metal mold casting, etc
1. Precision cast bushing.
Investment casting is also known as investment casting: it is to select the appropriate investment materials to make the investment mold, and then melt the investment mold away to obtain the cavity, and then cast the composite bushing. The advantages of precision casting composite bushing are relatively high, with less machining allowance, but the process is complex, the cost is high, the internal quality is not stable, and there is a certain proportion of defective products.
2. Centrifugally cast bushing.
Centrifugal casting also uses metal mold to inject copper liquid into the high-speed rotating mold, so as to make the copper liquid fill the mold with centrifugal movement and resist the formation of copper sleeve. Because the centrifugal movement can well form the free surface of the composite sleeve, the inner hole of the cylinder can be obtained without the core, because it is the centrifugal rotation, which produces centrifugal force, and the gas and clamp generated in the forming of the composite sleeve are ribbed The ballast can be effectively discharged, so as not to produce defects such as pores, sand holes and ballast inclusions.
3. Sand casting copper sleeve.
Sand casting is the original casting method, which has a history of thousands of years. Sand casting equipment is simple, labor intensity is high, and environment is poor. The casting composite bushing is easy to have defects such as sand hole, air Confucius and shrinkage porosity. Now only small-scale production workshops still use this process to produce composite bushing.
4. Metal mold casting composite bushing, the metal mold is steel mold as the mold, generally static casting, metal mold casting composite bushing external dimension comparison standard, because is static casting, also easy to produce a series of quality problems such as porosity, shrinkage porosity, ballast, etc., the qualified proportion of products is relatively low, so it is rarely used.