The use of double tool lathes to process the same workpiece, if using a different process, the efficiency will be a lot of difference. The core here is the balance of cycle time, ie processing time. Among them, one is the balance between the processing time between the front and the back of the two processes, and the second is the balancing of the processing time between the top and bottom tool carriers in each process. If the measures are reasonable, the ergonomics can be improved a lot. As shown in Figure 1 and Figure 2 is a bearing inner ring before and after the two processes. In the previous process, the T1 and T2 tools are mounted on the upper tool holder, and the T3 and T4 are installed on the lower tool holder. After the process, the T1, T2, and T3 tools are mounted on the upper tool holder, and the T4, T5, and T6 tools are installed on the lower tool holder. . 
Figure 1 Prior process of bearing inner ring
1. Small oil groove cutting part and small outside diameter fine cut part 2. Raceway fine cut part
3. Small end face rough cut 4. Small outside diameter and raceway rough cut
5. Large oil groove cutting part 6. Large rib cutting part and fine-faced part Figure 2 The inner ring of the bearing is processed according to the conventional method. The previous process does not have the T3 knife in the figure, but there is more in the process chart. T7 knife (actually the previous process T3 knife moved over), that is, the large rib 3 roughing part placed in the latter process turning. The cycle time of the previous process was 61s, and the cycle time of the later process was 89s. This workpiece is mass-processed, the former process time is very loose, and the post-process time is very tight, which affects the processing efficiency. The first measure is to move a knife to the previous process after the process, as shown in the figure. The original process used 3 knives, namely, one knives installed two knives, and the other knives were equipped with a knives. No matter how arranged, the processing time of the upper and lower knives cannot be balanced. Now, after the two cutters are installed on the upper and lower cutters, the cutting path can be reasonably arranged so that both the upper and lower cutters can end cutting at the same time, and the cutter can be retracted at the same time. This reduces the cycle time of the previous process to 72 s. At this time, the cycle time of the subsequent process is 78 s. At this point, the cutting time of upper and lower tool rests of the upper process is balanced, and the processing time of the front and rear processes is still unbalanced. It was observed that the time of the upper and lower tool post processing of the post process is one of early completion and one end of late is very different. Thus, in the following process 6, the three knives were mounted on the upper knives, and three on the premise of the lower knives. Four kinds of cutting programs were performed. After calculation and actual cutting, the present program was selected: The lower tool post basically ends cutting and retracting. The cycle time is also 72s. At this point, not only the processing time of the upper and lower turrets of the pre- and post-processes is balanced, but also the cycle time of the pre- and post-processes is balanced. It can also be said that this is the best solution. If the former and latter processes are combined into one production line, then the cycle time of this line will be reduced from the original 89s to the current 72s, shortening the processing time by 19% and significantly improving the work efficiency.
Figure 1 Prior process of bearing inner ring
1. Small oil groove cutting part and small outside diameter fine cut part 2. Raceway fine cut part
3. Small end face rough cut 4. Small outside diameter and raceway rough cut
5. Large oil groove cutting part 6. Large rib cutting part and fine-faced part Figure 2 The inner ring of the bearing is processed according to the conventional method. The previous process does not have the T3 knife in the figure, but there is more in the process chart. T7 knife (actually the previous process T3 knife moved over), that is, the large rib 3 roughing part placed in the latter process turning. The cycle time of the previous process was 61s, and the cycle time of the later process was 89s. This workpiece is mass-processed, the former process time is very loose, and the post-process time is very tight, which affects the processing efficiency. The first measure is to move a knife to the previous process after the process, as shown in the figure. The original process used 3 knives, namely, one knives installed two knives, and the other knives were equipped with a knives. No matter how arranged, the processing time of the upper and lower knives cannot be balanced. Now, after the two cutters are installed on the upper and lower cutters, the cutting path can be reasonably arranged so that both the upper and lower cutters can end cutting at the same time, and the cutter can be retracted at the same time. This reduces the cycle time of the previous process to 72 s. At this time, the cycle time of the subsequent process is 78 s. At this point, the cutting time of upper and lower tool rests of the upper process is balanced, and the processing time of the front and rear processes is still unbalanced. It was observed that the time of the upper and lower tool post processing of the post process is one of early completion and one end of late is very different. Thus, in the following process 6, the three knives were mounted on the upper knives, and three on the premise of the lower knives. Four kinds of cutting programs were performed. After calculation and actual cutting, the present program was selected: The lower tool post basically ends cutting and retracting. The cycle time is also 72s. At this point, not only the processing time of the upper and lower turrets of the pre- and post-processes is balanced, but also the cycle time of the pre- and post-processes is balanced. It can also be said that this is the best solution. If the former and latter processes are combined into one production line, then the cycle time of this line will be reduced from the original 89s to the current 72s, shortening the processing time by 19% and significantly improving the work efficiency.