Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
19.73 Кб


Automation is a word coined in the 1940s to describe process by which machines do the tasks previously performed by people. The word was new but the idea was not. As one knows, simple automatic devices are not new, too. Soon after the first machine tools appeared late in the 18th century, engineers modified them so that they could work by themselves for some of the time. An operator simply set his machine so that it cut a piece of metal automatically. He did not have to do anything while the operation took place.

When machining a workpiece in a metal cutting machine tool one can classify all operations as either processing or handling ones. Processing operations are those in which the actual cutting process or chip removal takes place. The rest are handling operations including loading and clamping the work, releasing and unloading it, checking the size of it, etc.

Machine tools performing the majority of the required handling operations without the direct participation of the operator are called automatic machine tools. Automatics have a fully automatic working cycle repeated to produce duplicate parts without participation of the operator, all of the working and handling operations being performed in a definite sequence by the control system.

Machine tools performing actual machining operations automatically in the same manner as in automatics are called semi-automatics. In this case, however, the operator loads the blank into the machine, starts the machine, checks the work size and removes the completed piece by hand. That is, the machining cycle is automatic, the operator starting each subsequent cycle.


It is known that cutting is one of the oldest arts practised in the stone age

It was in the time of Peter the Great when the first Russian machine tools were built

Now nearly in every machine shop one can find a lot of machines being used for working metals. These cutting machines are generally called machine tools and are extensively used in different branches of engineering to produce machines, instruments and tools of all kinds.

. Fundamentally, all machine tools remove metal and can be divided into the following categories: turning machines (lathes), drilling machines, boring machines, milling and grinding machines. The cutting tool is that part of a machine tool which serves for removing material from a revolving work.

The shape of the tool is known to depend upon a large number of factors such as the specific operation the material to be cut and the material the tool is made of.

Cutting tools are made of hardened steel or alloy metals

These tools having one effective cutting edge along which excess material from the workpiece is removed are known as single-point cutting tools.

Other tools removing excess material on two or more cutting edges simultaneously are known as multipoint cutting tools

It is known that cutting tools used for longitudinal turning and subdivided into roughing tools and finishing tools

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]