1. Optimization of mold design and manufacturing
Mold is the key foundation of Precision Shaft Die Casting Processing. In the mold design stage, the first thing to do is to ensure the parallelism of the two end faces of the mold cavity. Through high-precision processing equipment and precise measuring tools, the parallelism error of the two end faces of the mold cavity is controlled within a very small range, for example, within ±0.01mm. At the same time, setting reasonable positioning devices on the parting surface of the mold, such as precisely positioned guide pins and guide sleeves, can keep the mold in an accurate position during the mold closing process, thereby ensuring the parallelism of the two end faces during shaft die casting. In the mold manufacturing process, advanced processing technologies such as electrospark machining and precision grinding are used to finely process the mold cavity so that the surface roughness of the cavity reaches below Ra0.8, creating conditions for die-casting the two end faces of the shaft with good flatness.
2. Precise control of die-casting process parameters
Die-casting process parameters have an important influence on the flatness of the two end faces of the shaft. Pouring temperature is one of the key factors. The appropriate pouring temperature can ensure the fluidity and filling of the molten metal. Generally speaking, the pouring temperature should be controlled within a suitable range according to different alloy materials. For example, when aluminum alloy is die-casted, the pouring temperature can be controlled at 680-720℃. Too high a pouring temperature will cause uneven shrinkage of the molten metal, resulting in deviation in the flatness of the two end faces of the shaft; too low a pouring temperature will result in incomplete filling. The die-casting pressure also needs to be precisely controlled. Excessive pressure may cause deformation of the mold and affect the flatness of the two end faces of the shaft. The pressure should be reasonably adjusted according to the size of the shaft and the structure of the mold so that the molten metal can smoothly fill the mold cavity. In addition, the die-casting speed should also be moderate to avoid uneven impact of the molten metal on the two end faces of the mold cavity.
3. Reasonable application of die-casting post-processing technology
The post-die-casting treatment should not be ignored to ensure the flatness of the two end faces of the shaft. After demolding, the shaft should first be properly cooled to avoid deformation caused by uneven temperature. For some shafts with slightly deviated flatness, a straightening process can be used. There are many ways to straighten, such as mechanical straightening and thermal straightening. Mechanical straightening is to apply pressure to the shaft through a press to straighten the bent part, but this method may leave certain marks on the shaft surface and require subsequent surface treatment. Thermal straightening uses the plastic deformation characteristics of metal to correct the bending of the shaft at a certain temperature. This method is relatively gentle to improve the flatness of the two end faces of the shaft.
4. Establishment of quality inspection and feedback mechanism
Establishing a complete quality inspection system is an important means to ensure the flatness of the two end faces of the shaft. During the die-casting process, regular sampling inspections are carried out on shaft products, and high-precision flatness measuring instruments such as electronic levels or three-coordinate measuring machines are used to accurately measure the flatness of the two end faces of the shaft. If it is found that the flatness does not meet the standard, the cause should be analyzed in time, which may be mold wear, changes in die-casting process parameters, or improper post-processing. According to the analysis results, the mold or process parameters are adjusted in time, and the adjustment information is fed back to the production process to form an effective quality control closed loop and continuously optimize the guarantee measures for the flatness of the two end faces of the shaft.
