04-05-2012, 11:25 AM
Crank and connecting
mech mini project.docx (Size: 25.6 KB / Downloads: 67)
INTRODUCTION
Coimbatore is a highly industrial city. This is mainly due to entrepreneurship of local people. As there is no public sector undertaking. The small-scale industries through lathe and other general-purpose machines like drilling machines tools; they find it difficult to get a good finished square and polygon shaping in the components.
For producing square and polygon holes we have slotting and broaching machines. But it slow process, the cost is high and setting time is more. A lot of time and manual work is involved in this method. So this process “DESIGN AND FABRICATION OF SLOTING ATTACHMENT IN DRILLING MACHINE” is very much useful, if it is provided with good quality form tools of different shapes and sizes. Hence need exists for attachment which can produced non-circular holes at maximum cost. Thus an attempt is made to design and fabricate such an attachment.
REVIEW OF STATE OF ART
Available Method of Producing Non-Circular Holes:-
All component which are produced do not have circular holes, they are non circular holes also. Now-a-day most of the components having non circular holes are produced using broaching or slotting machine. By using our attachment such kind of jobs can be easily completed especially for small scale industries and for batch production where procurement and operation of machining and slotting machines would be uneconomical.
Disadvantages of Present methods:
• It is difficult.
• Possibility of injuries is more.
• Labour cost and production cost is more.
• More physical and mental fatigue.
• Skilled operators and supervisors are required.
TYPE OF SLOTTING MACHINE
The slotting machine falls under the category of reciprocating mechanism similar to the shaper and a planer.
• Puncher slotter
• Precision slotter
Puncher slotter:
The Puncher slotter is a heavy rigid machine designed to operating large quantity of metal from large forgings. The stroke length may be varied from 1800 to 2000mm.
Precision slotter:
The Precision slotting machines is lighter and operate at low speeds when compared to puncher slotting machine. The machine is designed to finish the jobs in appropriate manner by using special jigs. The machine can handle the jobs identical works due to increase the production. The precision slotting machine also used for general purpose work. The machine has quick return mechanism.
Slotter size:
The size of a general purpose or precision slotter usually from 80mm to 900mm.
Slotting machine parts
Base:
The base is rigidly built to take all the cutting tools and the entire load of the machine. The bottom of the bed is smoothly finished to provide good seating of the work piece. The column is fitted to the bed at the centre and tightly bolted. The column can be rotated in any direction.
Column:
The column is a vertical member which is made of M.S. pipe. It is fitted to the centre of the base by two bolts.
Ram/slider:
The ram is a reciprocating member of the slotting machine. It is mounted on the side ways between the top and bottom levels. It supports the tools.
Drive mechanism:
The slotter removes the metal during the downward cutting stroke. During the upward return stroke, the metal is not removed. The ram is driven by whith worth mechanism.
Holding methods:
The slotter can be fixed on the job itself while machining heavy jobs .If we want to machines smaller jobs they are held by vice, ’T’ bolts, and clamps by special fixtures. The slotting machines are used to cut the job without touching the table.