26 June 2017

Broaching machine

Broaching process is the simplest of all machine tools that can be performed on a broaching machine. It can be consist of a work welding fixture, broaching tools, a drive mechanism and suitable supporting frame. Although the component parts are few, several variations are possible. 

There are two principal types of machine :
  • Horizontal 
  • Vertical 
In addition to these standard types, there are special and continuously operating machines. Both horizontal and vertical types have one or more rams depending on production recruitment. Dual ram models are arranged so that when one ram is on the cutting stroke the other is on the return stroke and the return stroke is performed quickly to gain time, which is used to and load the machine. 

Broaching machines usually pull or push the approach through, or past a work piece that is held in a fixture. On some machines, however, the work piece is moved past that is fixed position. Most broaching machines operated to secure a smooth, uniform cutting action.

Horizontal broaching machine :

Most of all broaching machines at the pull type. They may be used for either internal or external broaching. The horizontal broaching machine consists of a bed or a little more than twice the length of broaching stroke, a broach pilot and the drive mechanism of pulling the brooch. 
It is used in many application especially for broaching keyways, splines, slots, round holes and other internal shapes or contours. They have the disadvantages of taking more floor space than vertical machines. 

Vertical broaching machine :

The vertical type may be obtained in either push or pull type. The push-type is more popular. It can be employed in multiple operations, since they are convenient to pass work from one machine to another, and they are more likely to be found doing surface operations. Of the three models available pull-up, pull-down and push down, the pull-up type is most popular. 

Vertical machines require an operator platform or a pit and are economical of floor space than the horizontal type.

Surface broaching machine :

Surface broaching machines have their broaching tools attached to the ram or ram forced in a straight path along with guide ways past the work piece. On some machines, the ram moves horizontally on other vertically. When two rams are used, the machine is called duplex broach. 

Continuous broaching machines : 

For mass production of smart small parts, the highly productive continuous broaching method is used on rotary or horizontal continuous-broaching machines. 

In this machine the work piece is loaded on the table which rotate continuously. During the operation the broach is stationary. 

In the horizontal continuous broaching machine the work piece travel as they are carried by an endless chain. The work piece are loaded into work holding fixture that is mounted on the continuous moving chain. During the operation the broach is stationery as before. Such machines are used for broaching small parts.