A lathe is a machine tool that uses a turning tool to turn a rotating workpiece. Drills, reamers, reamers, taps, dies and knurling tools can also be used on the lathe for corresponding processing. Lathes are mainly used for machining shafts, disks, sleeves and other workpieces with rotating surfaces. They are the most widely used machine tools in machinery manufacturing and repair plants.
In ancient times, lathes were cut by hand or pedals, rotating a workpiece through a rope, and holding a tool. In 1797, the British mechanical inventor Mozley created a modern lathe that uses a screw to drive a tool post. In 1800, it used an exchange gear to change the feed speed and the pitch of the thread being processed. In 1817, another Englishman, and Roberts, adopted a four-stage pulley and back wheel mechanism to change the spindle speed.
In order to improve the degree of mechanization and automation, Fitch in the United States invented a turret lathe in 1845; in 1848, a turning lathe appeared in the United States; in 1873, Spencer in the United States made a single-axis automatic lathe, and soon he made it again. Three-axis automatic lathes; lathes with gearboxes driven by separate motors appeared in the early 20th century.
After the First World War, due to the needs of the arms, automobile and other machinery industries, various efficient automatic lathes and specialized lathes developed rapidly. In order to increase the productivity of small batches of workpieces, lathes with hydraulic profiling devices were popularized in the late 1940s, and at the same time, multi-tool lathes were also developed. In the 1950s, program-controlled lathes with perforated cards, latch plates and dials were developed. Numerical control technology began to be used on lathes in the 1960s, and it developed rapidly after the 1970s.
Lathes are divided into many types according to their uses and functions.
Ordinary lathes have a wide range of processing objects, a large range of adjustment of the spindle speed and feed rate, and can process the internal and external surfaces, end faces, and internal and external threads of the workpiece. This lathe is mainly operated manually by the workers, which has low production efficiency and is suitable for single-piece, small-batch production and repair workshops.
The turret lathe and the rotary lathe have a turret tool holder or a return tool holder capable of holding multiple tools, which can be used by a worker to complete a variety of processes by using different tools in turn in one clamping of the workpiece, which is suitable for batch production.
The automatic lathe can automatically complete the multi-step processing of small and medium-sized workpieces according to a certain program, can automatically load and unload, and repeatedly process a batch of the same workpiece, which is suitable for large-scale and mass production.
Multi-tool semi-automatic lathes are divided into single-axis, multi-axis, horizontal and vertical. The single-axis horizontal layout is similar to that of ordinary lathes, but the two sets of tool holders are installed at the front, back, or top of the spindle, respectively, for machining discs, rings, and shafts. The productivity is 3 to 5 times higher than that of ordinary lathes.
The profiling lathe can automatically follow the shape and size of the prototype or the sample to automatically complete the processing cycle of the workpiece. It is suitable for the small batch and batch production of more complex workpieces. The productivity is 10-15 times higher than that of the ordinary lathe. There are multi-tool post, multi-axis, chuck, vertical and other types.
The main axis of the vertical lathe is perpendicular to the horizontal plane, the workpiece is clamped on a horizontal rotary table, and the tool holder is moved on the beam or column. It is suitable for processing large, heavy, and difficult to install workpieces on ordinary lathes, which are generally divided into two categories: single column and double column.
While turning the shovel tooth lathe, the tool post periodically reciprocates in the radial direction, which is used to form the tooth surface of the shovel milling cutter, hob, etc. A small grinding wheel, usually with a shovel attachment, is used to grind the tooth surface.
Specialized lathes are lathes used to process specific surfaces of certain types of workpieces, such as crank lathes, camshaft lathes, wheel lathes, axle lathes, roll lathes, and ingot lathes.
Combined lathe is mainly used for turning, but after adding some special parts and accessories, it can also perform boring, milling, drilling, inserting, grinding and other processing. It has the characteristics of "one machine and multiple functions" and is suitable for engineering vehicles, ships or mobiles. Repair work at a repair station.