How to prevent defects from tin bronze plate

The defects of the tin bronze plate are mainly manifested in the unreasonable structural design of the casting, sharp corners, and the wall thickness of the casting is too different; the sand mold (core) has poor retreat; the mold is partially overheated; the pouring temperature is too high; Premature; heat treatment is overheated or overburned, and the cooling rate is excessive.
How to prevent tin bronze plate casting defects: improve the structural design of the casting, avoid sharp corners, strive for uniform wall thickness, and smooth transition; take measures to increase the concession of the sand mold (core); ensure that all parts of the casting solidify at the same time or sequentially, and improve pouring System design; appropriately reduce the pouring temperature; control the cooling time of the mold; adopt the thermal correction method when the casting is deformed; correctly control the heat treatment temperature and reduce the quenching cooling rate.
After the tin bronze crankshaft is bent and deformed, eccentric wear occurs on the working surface of the cylinder, the copper sleeve of the small end of the connecting rod and the connecting rod bushing are overheated and worn in the early stage of the bearing steel sleeve, and the crank shaft is ground into a conical shape. Therefore, in the overhaul or intermediate repair of the compressor, the bending of the crankshaft should be checked, so as to detect and take corresponding measures as soon as possible, so as to avoid greater damage to the copper sleeve of the agricultural machinery. Before the inspection, the crankshaft should be cleaned and placed on the “V”-shaped frame of the inspection platform, or the center hole at both ends of the crankshaft should be pushed on the lathe with a thimble, and then the dial indicator should be used for inspection.
During inspection, align the dial indicator with one or two main journals in the middle of the crankshaft at the measuring point, and slowly rotate the crankshaft by hand for one turn. The swing indicated on the dial indicator is the bending swing of the crankshaft. The result of the cylinder ear ring copper sleeve measured in this way may have a large error, because it also involves the out-of-roundness of the two main journals and the middle main journal supported on the “V” frame. Whether the bending swing of the crankshaft has any influence; if so, adjust the bending swing of the crankshaft according to the situation.