A lathe that can automatically complete a work cycle according to a certain program after loading and adjustment, and repeatedly process a batch of workpieces. A lathe that can automatically complete work cycles except for 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 higher productivity.

According to the number of spindles, automatic lathes are divided into two categories: single spindle and multi spindle. The former mainly has three types: single axis longitudinal cutting, single axis turret, and single axis transverse cutting; The latter mainly has two types: sequential operation and parallel operation, and there are vertical and horizontal types according to the configuration of the spindle.

Machine tools generally use cams and stops to automatically control the movement of tool holders, spindle boxes, and other auxiliary movements. The single axis longitudinal cutting automatic lathe (Figure 1) uses cold drawn bar stock as the blank, and in addition to rotation, it also feeds longitudinally with the main axle box. The tool holder cuts and feeds laterally, achieving high machining accuracy.

The machine tool is also equipped with accessories for drilling, reaming (see Reaming), and thread cutting, making it an important mechanical processing equipment in the instrument industry. The single axis turret automatic lathe has a turret tool holder and multiple lateral tool holders, which can be sequentially cut with multiple cutting tools and is suitable for processing small workpieces with complex shapes.

The spindle box and tool holder of a single axis transverse cutting automatic lathe do not engage in longitudinal feed motion, but rather complete the cutting process through the transverse feed motion of the forming tool. This type of machine tool is only used for machining pins and shafts with simple shapes and small dimensions.

The multiple spindles (usually 4, 6, and 8) of a sequential operation multi axis automatic lathe (Figure 2) are installed in a periodically indexable spindle drum. The billets clamped in the spindle are sequentially processed by each workstation to complete different processes, and cut or unloaded at the last workstation.

This type of lathe is suitable for processing workpieces with complex shapes. Parallel operation multi axis automatic lathes have several fixed spindle positions (usually 2 or 4), and are suitable for processing workpieces with simple shapes by performing the same process on several workstations simultaneously.

Automatic lathes with cams and stops as control components work stably and reliably, and still account for the majority in automatic lathes.

But when the workpiece changes, the cam needs to be redesigned and manufactured, and it takes a lot of time to adjust the machine tool, so it is only suitable for mass production. Since the 1950s, there have been programs controlled automatic lathes using pin boards and digital controlled automatic lathes using perforated strips or electronic computers, which have also been applied in small and medium-sized batch production.

Safety operating procedures

(1) Before work, lubricate the machine tool according to regulations, check if all handles are in place, and run the machine slowly for five minutes to confirm that everything is normal before operation.

(2) The chuck chuck should be securely fastened, and the wrench should not be left on the chuck or chuck when starting the machine.

(3) The workpiece and tool clamping should be firm, and the tool bar should not extend too long (except for boring holes); When rotating the small tool holder, stop it to prevent the tool from colliding with the chuck, workpiece, or scratching the hand.

(4) When the workpiece is running, the operator cannot stand directly against the workpiece, do not lean against the lathe, and do not step on the oil pan.

(5) When high-speed cutting, chip breakers and protective screens should be used.

(6) It is prohibited to reverse brake at high speeds, and the vehicle should be backed up and parked smoothly.

(7) Remove iron filings using a brush or special hook.

(8) When using a file to polish the workpiece, the right hand must be in front and the left hand must be behind; When using sandcloth to polish the workpiece, tools such as "hand clamps" should be used to prevent twisting.

(9) All labor, quantity, and cutting tools should be placed in a safe location nearby, in a neat and orderly manner.

(10) If the lathe has not stopped stably, it is prohibited to take or measure workpieces from the front of the lathe.

(11) When the lathe is working, it is prohibited to open or remove protective devices.

(12) Near the end of work, the lathe should be cleaned and tested, and the tailstock and slide box should be retracted to the far right end of the bed.