Industry news|2022-04-14| admin
There are many processing techniques for precision racks, each of which is based on different materials and requirements for rack accuracy, and then selects the correct processing method. There are two main processing methods for precision racks, for some racks with high precision and hardness, including material heat treatment and tooth profile processing. Two wire cutting tooth profiles and two heat treatment profiles are used. After two heat treatments and two wire cutting cycles, the fabricated rack can not only overcome the hardenability of the material after heat treatment, but also meet the hardness requirements, ensure the requirements of high tooth shape accuracy, and improve the coaxiality between the tooth shape and the outer circle. Spend.
Therefore, this method has great advantages, that is, the overall hardness of the tooth profile can meet the requirements, and the accuracy of the tooth profile can meet the design requirements, thereby greatly improving the machining quality of the rack. The processing of the shelf largely determines the hardness and precision of the shelf. Therefore, in the process of shelf processing, the whole process of shelf should be strictly controlled, and different shelf processing methods should ensure that products can be processed into products that meet the requirements of use.
Process flow of precision rack surface quenching: First, put the processed rack into the induction coil. When alternating current of different frequencies is applied to the inductor, an alternating magnetic field will be generated around it. The electromagnetic induction of the alternating magnetic field cuts off the felt current in the part. The diffusion of the induced current on the cross section of the workpiece is very uneven, and the current density on the surface of the workpiece is relatively high and gradually decreases inward.
At this time, the electric energy of the high-density current on the surface of the rack is converted into heat energy, so that the surface temperature of the rack rises, and the surface temperature of the parts rises rapidly. The higher the current frequency, the greater the current density difference between the surface layer and the inner layer, and the thinner the heating layer. After the temperature of the heating layer exceeds the critical temperature of the steel, the rack is rapidly cooled and quenched.
The precision rack tooth surface has higher strength and better wear resistance than the rack tooth surface without heat treatment after vacuum quenching heat treatment.
Precision racks have the characteristics of high strength and high wear resistance. All materials are tempered, so the strength of the rack is greatly improved, suitable for high-precision linear motion, and the direction of linear motion can be changed at any angle. The rack module is small, easy to move and install, and very convenient to use and install in the occasion of reciprocating motion.
Micro-deformation control and process stability control in gear machining are complex. In order to obtain good machinability and a uniform metallographic structure that tends to deform, isothermal normalizing should be used after forging. For low-speed spur gears with low precision, the teeth can be shaved before heating, but not after heating. The application of radial shaving method expands the application range of shaving. There are two methods for hot finishing of cylindrical gears: honing and grinding. The honing cost is low, but the tooth profile correction ability is weak, the grinding precision is high, and the cost is high.