## 5 Verification of Comprehensive Evaluation Model for Honing Processing Quality
### Effect of CBN Grain Size on Honing Quality  
#### 5.4.1 The Relationship Between Grain Size and Honing Precision  
(1) Total deviation between grain size and helix  
As shown in Figure 6, As the abrasive mesh size increases, the size of the abrasive decreases. After honing, the average value of the spiral deviation of 300# and 540# abrasive particles decreases successively, and the difference between them is very small. The smaller the abrasive grain size, the more concentrated the helical total deviation distribution of the workpiece tooth surface after honing so that the minimum helical error of 540# is smaller than the corresponding value of 300#. After machining with 100#, 300#, and 540# grinding wheels, the total screw deviation of the workpiece tooth surface is improved in different degrees, and the improvement degree is affected by the error accumulation and error recurrence before honing. Under the machining of the 540# honing wheel, the maximum error of the tooth line of No. 21 gear did not decrease significantly. In actual production, by increasing the number of honing operations, the error replication coefficient and the maximum error of the helix of the workpiece tooth surface can be effectively reduced. The honing precision can be improved to meet the design requirements. Figure 5: Gear honing quality test instrument and method. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & **Mesh** & **Coating** & **Impact** & **Horbiece** & **Honing** & **Honing** & **Feed** & **Time t** & **Cutting** \\  & **Size** & **Thickness** & **Toughness T1** & **Workpiece** & **Speed v\({}_{\text{e}}\)** & **Depth a\({}_{\text{p}}\)** & **Speed f** & **Time t** & **Conditions** \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Numerical value \\ \end{tabular} } & 100* & 0.25 & 41\% & \multirow{3}{*}{20 CrMnTi 0.075} & 20 CrMnTi 0.07n (HRCS8-60) & & & & No Cutting fluid \\ \cline{1-1} \cline{6-10}  & 300* & 0.075 & 48\% & & & & & No Cutting fluid \\ \cline{1-1} \cline{6-10}  & 540* & 0.025 & 50\% & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Honing gear experimental parameters. Grain size and single pitch deviation. In the electronic gearbox, the workpiece gear and the honing wheel are forced to engage according to the theoretical transmission ratio, which plays a significant role in correcting the pitch deviation. In Figure 7, with the increase in abrasive mesh size, the algebraic difference between the measured tooth pitch and the theoretical tooth pitch decreases progressively. The distribution of pitch deviation is also gradually approaching the zero line, which indicates that the ability to correct the change of common normal length is enhanced, so the machining accuracy of honing teeth is improved. The pitch error of the workpiece shows an obvious sinusoidal distribution after 540\({}^{\#}\) abrasive honing, which reflects the circular run-out error between the honing wheel and the workpiece. It is a random error generated by the previous process. After honing, the pitch error is obviously reduced. Due to error accumulation, the pitch error of the workpiece is still approximately sinusoidal. In the subsequent work, the error recurrence coefficient can be effectively reduced by increasing the number of honing operations. Figure 6: CBN grain size and total deviation of tooth surface helix. Figure 7: Comparison of single pitch deviation before and after honing. (3) Cumulative total deviation of grain size and tooth profile  
As shown in Figure 8, the average value of the cumulative total deviation of the tooth profile decreases with the increase of abrasive mesh size, which indicates that the accuracy of the workpiece is gradually improved after honing. For the wheel with a large prehoned tooth profile deviation, the tooth profile deviation curve of the honed wheel after precision reshaping is closer to the theoretical value.