Test 2. Turret lather

Turret lathes differ from centre lathes and engine lathes In that they do not have p tailstock but have a turn Instead, at the end opposite the spindle. The turret serves to hold cutting tools used in machining the work.

Turret lathes are expedient when a considerable number of different tools, having axis aligned with the work axis (drills, core drills, reamers, etc.), are required for machining. They are also used for doing turning operations without making test outs and measurement. The machining possibilities of turret lathes are very extensive.

It is accepted that parts having length dimensions of the 4th or 5th grade of accuracy and external diameters с the 3 rd or 4 th grade of accuracy, can be economically machined on turret lathes.

The use of multiple-tool holders on turret lathes enables them to make multiple outs simultaneously.

The two main groups of turret lathes are those with vertical and those with horizontal axis of turret rotation.

Turret lathes of the first group, with a turret indexing about a vertical axis, usually have a cross slide carriag with a square turret similar to the type used on engine lathes.

The more extensively used turret lathes with a horizontal axis of turret indexing do not have a cross slid carriage.

Hexagon turrets which index about a vertical axle have six tool holes. Tools which can be used in a standar set up (for machining a number of similar parts) are mounted in the tool holes of the turret to the beet advantage Turret lathes with a vertical axis of the turret are avail able with either a front carriage or with both front and re; carriage. Hear carriages are employed for grooving, facing, and cutting off and have only a cross-feed. Front carriages in these turret lathes perform the same operations as on engine lathes.

Turrets of all types of turret lathes travel along the spindle axis to the stops. Turret lathes with a horizontal ax of turret indexing usually have a circular, turret with 12 or 16 tools holes. Such turrets may be indexin periodically for consecutive operation of the tools. The turret may be also rotated slowly and continuously as fee in facing grooving, etc.

The type of turret lathes is particularly applicable when several operation elements require cross-feed of tools clamped in the turret.

Date: 2015-05-04; view: 669; Нарушение авторских прав