The gear hobbing and tool shifting on the gear hobbing machine can be completed by manual operation or automatic control on the gear hobbing machine. Automatic control of knife channeling is most suitable for mass production. However, manual gear shifting is usually used for a small number of production tasks and hob positioning gear machining.
When the hob uses manual gear shifting, it can still be set at a fixed value until the wear of the hob reaches the maximum allowable value. The gear of the hob is worn to a certain extent, and then the hob moves to the next gear.
When setting the tool shifting position of each tool, the maximum wear position of hob teeth usually occurs at the coarse hobbing (that is, the place where the tool just contacts the part). When setting a new hob channeling position, if the number of machined parts of hob teeth is less than the maximum allowable number of wear, that is, the maximum wear does not occur. Hob teeth will wear unevenly and waste.
If the hob must be machined with locating teeth, manual tool shifting is usually used. Every hobbing tool shifting must ensure a fixed size, and accuracy is very important. If automatic tool shifting is used, it is difficult to control whether the accuracy and position of tool shifting can be maintained. The amount of gear shifting depends on the position relationship between the hob and the gear. It is difficult to control the rotation ratio within a certain range by automatic control.
Many new gear hobbing machines have diversified functions of automatic tool shifting. After each hob is installed, the hob can automatically roll the teeth and move the tool according to the requirements of the parts, and reach the allowable number of hob wear. Change hob clamping and loosening into automatic control. The hob can be used for gear shifting and gear alignment with parts. Through many times of practice, the sharpened hob is installed on the gear hobbing machine, the hob moves in the same direction, and the increment is from small to large, so as to ensure that all tooth surfaces are used.
The main advantage of automatic hobbing and channeling of hob is that the wear of hob teeth can be controlled and the physical strength of operators can be saved when channeling. Once the number of gear hobbing tool shifting and the number of tool shifting of each hob are determined, an operation procedure can be established to ensure the repeated grinding performance of the hob. There should be corresponding grinding records for each hob, which can provide users with an accurate hob use cost.