The shape of tool edge is also an important factor affecting the tooth surface roughness in gear hobbing. Two hole diameters are selected in the experiment Φ The integral high-speed steel hob with positive rake angle of 40mm and length of 143 mm shall be passivated respectively. The first hob is 50 μ The cutting edge of M arc is passivated, and the second hob is passivated at 10 μ M arc for edge passivation, select 2 groups of 10 20CrMnTi gear specimens for experiment, measure the tooth surface roughness and take the average value.

Analyze the data and draw the box line as shown in the figure. It can be seen from the figure that the passivation arc size of the hob edge has an obvious influence on the tooth surface roughness, with 50 μ The surface accuracy ratio of gear machined by M edge arc hob is 10 μ The gear surface precision processed by cutting edge arc of M is higher.