What are the processing steps of the gear during the machining process? What problems do we need to pay attention to during the processing?
Hot die forging is still a rough forging process widely used in automotive gear parts. In recent years, cross wedge rolling technology has been widely promoted in shaft processing. This technology is particularly suitable for more complex stepped shaft blanks, which not only have high precision, low processing margin, but also high production efficiency.
The purpose of this process is to obtain a hardness suitable for the subsequent gear cutting process and to prepare the tissue for the final heat treatment to effectively reduce the heat treatment deformation. The material of the gear steel used is usually 20CrMnTi. The general normalizing fire is relatively large due to the influence of personnel, equipment and environment, making it difficult to control the cooling rate and uniformity of the workpiece, resulting in large difference in hardness and uneven metallographic structure. Affecting metal cutting and final heat treatment, the thermal deformation is large and irregular, and the quality of the parts cannot be controlled. To this end, an isothermal normalizing process is employed. Practice has proved that the use of isothermal normalizing effectively changes the drawbacks of general normalizing, and the product quality is stable and reliable.
3. Turning processing
In order to meet the positioning requirements of high-precision gear machining, the machining of the blanks is all based on CNC lathes. The mechanical clamping does not re-grind the turning tools, which realizes the simultaneous completion of the machining of the aperture, end face and outer diameter under one clamping, which guarantees the inside. The verticality requirements of the holes and the end faces ensure that the size of the large-scale tooth blank production is small. Thereby, the accuracy of the tooth blank is improved, and the processing quality of the subsequent gear is ensured. In addition, the high efficiency of CNC lathe processing also greatly reduces the number of equipment and economical.
4. Rolling, shaping
The equipment used for machining the tooth part still uses a large number of ordinary gear hobbing machines and gear shaping machines. Although the adjustment and maintenance are convenient, the production efficiency is low. If the large capacity is completed, multiple machines need to be produced at the same time. With the development of coating technology, the re-coating of the hob and the inserting blade is very convenient. The coated tool can significantly improve the service life, generally can increase by more than 90%, effectively reducing the number of tool changes. And sharpening time, the benefits are significant.
The radial shaving technology is widely used in the production of high-volume automotive gears because of its high efficiency, easy designation of tooth profile and tooth orientation.
6. Heat treatment
Automotive gears require carburizing and quenching to ensure good mechanical properties. For products that are no longer subjected to grinding after heat, stable and reliable heat treatment equipment is essential.
7. Grinding processing
Mainly for the heat-treated gear inner hole, end face, outer diameter of the shaft and other parts to improve the dimensional accuracy and reduce the shape tolerance.http://www.delinggearbox.com/