mt ii manuals

7/29/2019 MT II Manuals

1/3

STUDY OF SHAPING MACHINE

BASE:

The base is made of cast iron. Cast iron is used to absorb vibration. The base is bolted to the floor. It

takes the entire load coming on the machine.

COLUMN:

It is made of cast iron. It has a box like construction. It is hollow inside. It is mounted upon the base.

Quick return mechanism for ram is placed inside the column. At the top of the column there are two

machined guide ways. The ram reciprocates on these guide ways. There are two guide ways at the

front vertical face of the column. Cross rail moves vertically along these guide ways.

CROSS RAIL:

This is mounted on the front vertical guide ways of the column. Cross rail has got two horizontal

guide ways in its front face. It is called saddle. The guide ways are perpendicular to the ram

movement. The table can be moved along these guide ways. Horizontal cross feed screw is fitted in

the cross slide. For vertical movement of the cross slide an elevating screw is provided.

TABLE:

It is a rectangular hollow cast iron block. The table slides on the horizontal guide ways of the cross

rail. It has machined surface on the top and slides. These surfaces have T-slots for clamping work.

The table can be moved horizontally by rotating the cross feed screw. The front face of the table is

supported by an adjustable table support.

RAM:

Ram carries the tool head at its front end. Ram reciprocates on the guide ways on the top of the

column. It is connected to the quick return mechanism. The stroke position of the ram can be

adjustable table support.

TOOL HEAD:

The tool head holds the tool. Vertical and angular feed can be given to the tool head. There is a

vertical slide. This slide can be moved vertically by rotating the down feed screw. A graduated dial is

fixed to the handle for the accurate movement of the vertical slide. There is a swivel base for the

tool head. It is graduated in degrees. The tool can be swivel led to the required angle. Apron is


2/3

clamped upon the vertical slide by a screw and nut. Apron can be tilted to the right or left and

clamped in that position.

QUICK RETURN MECHANISM

In shaper, the rotary motion of the driving motor is converted into reciprocating motion. This is done

by a mechanism placed inside the column. The ram holding the tool gets the reciprocating motion.

In a standard shaper metal is cut in the forward cutting stroke. During the return stroke , no

metal is cut. So it is known as idle stroke. To reduce the total machining time, the time taken for the

idle stroke should be reduced. So the return stroke is made faster than the cutting stroke. This is

done by a mechanism called quick return mechanism. The cutting stroke takes place at the required

cutting speed (cutting speed depends upon the work piece material, the tool material and machining

condition)

Quick return of the ram can be obtained by the following quick return mechanism.

1. Crank and slotted link mechanism2. Whit worth mechanism3. Hydraulic mechanism

We are using Crank and slotted link mechanism in our manufacturing technology loboratory for

shaping machine

WORKING OF CRANK AND SLOTTED LINK MECHANISM

An electric motor runs the driving pinion at uniform speed. The pinion rotates the bull gear at

uniform speed. Bull gear is a large gear fitted within the column.

A slide is fitted along the diameter on the face of the bull gear. The bull gear slide in the bull gear

slide. The position of the slide block can be adjusted radially by rotating the stroke adjusting screw.

This is done by rotating the bevel gears through a handle from outside.

A crank pin is fitted to the bull gear sliding block. The rocker arm sliding block is fitted freely over the

crank pin. The slotted link or rocker arm is pivoted at its bottom end. The upper end of the rocker

arm is in the form of a fork. It is freely connected to the ram block by a pin. The slotted link has a

slot, length wise. The rocker arm sliding block fits into this slot.


3/3

When the bull gear rotates, the crank pin also rotates. The rocker arm sliding block also rotates on

the crank pin circle. At the same time, the sliding blocks slides up and down in slotted of the slotted

link (rocker arm). This gives a rocking movement (oscillating movement) to the rocker arm. This

makes the ram to reciprocate.

PAWL AND RATCHET MECHANISM

In shaper, Pawl and ratchet mechanism is used as an automatic table feed mechanism. The

figure shows the automatic feed mechanism for the table of the shaper. The driving disc

gets the drive from the bull gear. The disc has a T-slot on its face along its diameter. A crank

pin fits into the slot. The position of the crank pin can be adjusted

mt ii manuals

Documents