Drilling is the process of producing hole on the work piece by using a rotating cutter called drill. The machine used for drilling is known as drilling machine. By a drilling machine holes are drilled.
There are two types of drilling machine available in the market for performing drilling operations.
We desired a drilling machine which will automatically index the job and gives automatic feed to the drill head. This machine is designed to perform drilling. Even though this is designed to drill a hole on circumference of a job, this can also perform a number of similar operations like drilling, remaining, boring, counter boring, counter sinking, tapping etc with slight alterations on the machine. We designed a drilling machine which uses only mechanical principles. Therefore it is very easy for maintenance and which improves the reliability of the machine.
This machine serves the main purpose of fabricating female die which is of immense use in textile industry.
The principle of operation of this machine is explained under three sub headings.
1. Driving mechanism
2. Feed mechanism
3. Indexing mechanism
1. DRIVING MECHANISM:
In driving mechanisms a single-phase AC motor is used for driving the whole machine. Though the speed of the motor is less, it can carry more loads on it. Power of the motor is 0.75 hp. The rotary motion of the motor is transmitted to the worm gear in the gearbox by chain and sprocket mechanism. A wheel is aligned to the worm gear and the motion is transmitted.
2. FED MECHANISM:
One side of the wheel inside the gearbox connected to the crank disc. Main function of the crank disc is to convert the rotary motion into linear vertical motion to get vertical feed for drilling head. A link mechanism in a lever connects crank disc and hand drilling machine. It helps to transmit vertical feed to the hand drilling machine.
3. INDEXING MECHANISM:
From the wheel with the help of link mechanism, motion is transmitted to an arm to which pawl-1 is connected. The movement of pawl is in such a way that it will push two teeth of ratchet-1 in each revolution to the front. After that the pawl will come back and the process is repeated.
INDEXING ROTARY MOTION OF THE JOB:
One side of the ratchet-1 is connected to three spur gears in order to reduce speed and the job will rotate depending on the movement of the ratchet. And hence the rotary motion of the ratchet is induced accurately.
INDEXING THE HORIZONTAL MOVEMENT OF THE JOB:
One small rod is connected parallel to ratchet-1. One rod is also placed perpendicular to the ratchet-1 in such a way that after each revolution of rod 1 with respect to the ratchet wheel; it should strike on rod 1. Rod 2 is connected to one spring arrangement so that is should comeback to the initial position after the rod 1 get struck rod 2 once. As rod 2 moves up due to the striking of rod 1. This will cause the pawl 2 to push one tooth of ratchet-2, which is connected, to rack and pinion, which will cause it to push one teeth of the rack and pinion. Rack and pinion is connected to the horizontal slide and it moves. Hence after each revolution of Job one horizontal motion will be there.
It is mainly used for drilling holes on female die.
It is used for large diesel engine pistons.
It is used in cylindrical component to drill and index in many industries.
It is used for drilling the hole cycle pre wheel spoke hole.
It is used in automobile wheel hub over drill holes.
It is applicable in drilling holes on flange couplings.
It is used for manufacturing hole on hand wheel.
Used to provide multiple numbers of holes on the periphery of index plate which may be used for index jig design.
It is used to drill holes on polygonal globes.
Taper drilling can be done easily and accurately.
It can index the job automatically at different uniform angles
Drilling time is faster than manual time.
It is very much advantageous to Mass Production Company.
Power consumption is less.
This equipment may be economical when compared to NC drilling machines, radial drilling machines, etc.
This equipment has no indexing drill jigs.
This machine reduces manual work of labour (40 to 50 hours)
Machine work = 20 hours (approx)
Automation cost is very high.
Construction of this machine is very complicated one.
Sachin is a B-TECH graduate in Mechanical Engineering from a reputed Engineering college. Currently, he is working in the sheet metal industry as a designer. Additionally, he has interested in Product Design, Animation, and Project design. He also likes to write articles related to the mechanical engineering field and tries to motivate other mechanical engineering students by his innovative project ideas, design, models and videos.