Mould Manufacturing Finishing Process – Parts Heat Treatment
There are three main types of machine tools used in grinding: surface grinders, internal and external cylindrical grinders, and tool grinders. The grinding deformation and grinding cracks must be strictly controlled during finishing grinding. Even very small cracks will be revealed during subsequent processing. Therefore, the feed of fine grinding should be small, not large enough, and the cooling liquid should be sufficient. The parts whose dimension tolerance is within 0.01mm should be heated as much as possible. From the calculations, it can be seen that when the temperature difference is 3°C, the 300mm-long steel piece has a material change of 10.8μm, 10.8=1.2×3×3 (1.2μm/°C per 100mm deformation), and each of the finishing processes needs to fully consider this. The effect of one factor.
It is very important to choose the right grinding wheel for fine grinding. For the high vanadium and high-molybdenum state of the mold steel, the GD single crystal corundum grinding wheel is more suitable. When processing hard alloys and materials with high quenching hardness, organic bonding is preferred. Agent diamond wheel, organic binder grinding wheel self-grinding, grinding rough workpiece up to Ra = 0.2μm, in recent years, with the application of new materials, CBN grinding wheel, namely cubic boron nitride grinding wheel shows Very good processing results, in the CNC molding grinding, coordinate grinding machine, CNC internal and external grinding machine finishing, the effect is better than other types of grinding wheel. In the grinding process, it is necessary to pay attention to dressing the grinding wheel in time to maintain the sharpness of the grinding wheel. When the grinding wheel is passivated, the workpiece will be rubbed and pressed on the surface of the workpiece, causing the workpiece surface to burn and the strength to decrease.
Most of the processing of plate parts uses surface grinders. In processing, they often encounter a thin and long thin plate parts. The processing of such parts is difficult. Because during processing, under the action of magnetic adsorption, the workpiece is deformed and clings to the surface of the workbench. When the workpiece is removed, the workpiece will be deformed again and the thickness will be measured uniformly, but the parallelism will not meet the requirements. Magnetically shielded grinding method can be used. When grinding, the block is placed under the workpiece under the same height, and the four-faced block resists death. When the machining is performed, the small-input tool can be used, and the multi-beam knife can be used. After machining one side, it can be used for direct adsorption processing. , This can improve the grinding effect and achieve parallelism.
Shaft parts have a rotary surface, and their machining uses a wide range of internal and external cylindrical grinding machines and tool grinding machines. In the processing process, the head frame and the top are equivalent to the busbar. If there is a problem of runout, the processed workpiece will also have this problem and affect the quality of the parts. Therefore, the headstock and the top inspection work must be done before processing. When grinding the inner hole, the coolant must be poured fully into the grinding contact position to facilitate the smooth discharge of the grinding. For machining thin-walled shaft parts, it is best to use a clamping process table. The clamping force must not be too large. Otherwise, it will easily cause “inside triangle” deformation on the circumference of the workpiece.