Machine Tool Applications

A lathe that can automatically complete a work cycle and repeatedly process a batch of workpieces according to a certain program after loading and adjustment. A lathe that can automatically complete a work cycle other than loading and unloading workpieces is called a semi-automatic lathe. Automatic lathes can reduce the physical labor intensity of workers, shorten auxiliary time, and allow one person to supervise multiple machine tools, resulting in high productivity.

According to the number of spindles, automatic lathes are divided into two categories: single axis and multi axis. The former mainly includes three types: single axis longitudinal cutting, single axis turret, and single axis transverse cutting; The latter mainly includes two types of operations: sequential operation and parallel operation, and can be classified into vertical and horizontal according to the configuration of the spindle. Machine tools generally use camshafts and blocks to automatically control the movement of the tool holder, spindle box, and other auxiliary movements. The single axis longitudinal cutting automatic lathe (Figure 1) uses cold drawn bars as raw materials. In addition to rotation, it also feeds longitudinally with the spindle box and horizontally with the tool holder, achieving high machining accuracy. The machine tool is also equipped with accessories for drilling, reaming (see reaming), and threading, and is an important mechanical processing equipment in the instrumentation industry. The single axis turret automatic lathe has turret tool holders and multiple transverse tool holders, which can be sequentially cut with various cutting tools and are suitable for processing small workpieces with complex shapes. The spindle box and tool holder of the single axis cross cutting automatic lathe do not perform longitudinal feed motion, but are cut by the transverse feed motion of the forming tool. This machine tool is only used for processing pin and shaft workpieces with simple shapes and small sizes. The multiple (usually 4, 6, or 8) spindles of the sequential operation multi axis automatic lathe (Figure 2) are installed in the spindle drum that can be periodically rotated. The billet clamped in the spindle passes through each station in sequence to complete different processing steps, and is cut or unloaded at the last station. This lathe is suitable for processing workpieces with complex shapes. Parallel operation multi axis automatic lathes have several fixed position spindles (usually 2 or 4), which can perform the same process on several workstations at the same time, making them suitable for processing workpieces with simple shapes.

The automatic lathe with cam and stopper as control components works stably and reliably, and still accounts for the majority in automatic lathes. But when the workpiece is changed, the cam needs to be redesigned and manufactured again, and it takes a lot of time to adjust the machine tool, so it is only suitable for mass production. Since the 1950s, program-controlled automatic lathes controlled by pin plates and digitally controlled automatic lathes controlled by perforated belts or electronic computers have emerged, and have therefore been applied in small and medium-sized production.