The Drilling Machine is one of the most important machine tools in a workshop, As regards its importance it is second only to the Lathe Machine, Although it was primarily designed to originate a hole, it can perform a number of similar operations, In a Drilling Machine holes may be drilled quicky and at a low cost. The hole is generated by the rotating edge of a cutting tool known as the drill which exerts large force on the work clamped a hole it is loosely called a “Drill Press”.
Holes were drilled by the egyptians in 1200 B.C. ABOUT 3000 YEARS AGO BY BOW DRILLS. The Bow drill is the mother of present day metal cutting drilling machine.
TYPES OF DRILLING MACHINE:-
1.Portable Drilling machine
2.Sensitive Drilling Machine
(a) Bench Mounting Drilling Machine
(b) Flour Mounting Drilling Machine
3.UP -Right Drilling Machine
(a) Round Column Drilling Machine
(b) Box Column Section Drilling Machine
4.Radial Drilling Machine.
(a) Plain Radial Drilling Machine
(b) Semi Universal Radial Drilling Machine
(c) Universal Radial Drilling Machine
5.Gang Drilling Machine
6.Multiple Spindle Drilling Machine.
7.Automatic Drilling Machine
8.Deep Hole Drilling Machine
(a) Vertical Deep Hole Drilling Machine
(b) Horizontal Deep Hole Drilling Machine
PORTABLE DRILLING MACHINE: As the name implies this type of drilling machine can be operated with ease any where in the workshop and is used for drilling holes in work pieces in any position which can not be drilled in a standard drilling machine. Some of the portable machines are operated by hand power, but most of the machines are driven by individual motor. The entire drilling mechanism including the motor is compact and small in size. The motor is usually of Universal type which me be driven by both A.C. and D.C.The maximum size of the drill that it can accommodate is not more than 12mm to 31mm. The machine is opened at high speed as smaller size drills are only used.Some of the portable machines are drivenby pneumatic power.
SENSITIVE DRILLING MACHINE: The sensitive drilling machine is a small machine designed for drilling a small holes at high speed in liht jobs. The base of the machine may be mounted on a bench or on the floor. It consists of a vertical column, a horizontal table, a head supporting the motor and driving mechanism and a vertical spindle for driving and rotating the drill. There is no arrangement for any automatic feed of the drill spindle.The drill is fed into the work by purely hand control. High speed and hand feed are necessary to attain required cutting speed by small diameter drill.
UPRIGHT DRILLING MACHINE: The UPRIGHT DRILLING MACHINE is also known as PILLAR DRILLING MACHINE. The upright drilling machine is designed for handling medium sized workpieces. In construction the machine is very very similar to a sensitive Drilling Machine. for having a vertical column mounted upon the base.But this is larger and heavier than a sensitive drill and is supplied with power feed arrangement. In an upright drilling machinea large number of spindle speeds and feeds may be avaialble for drilling different types of work, The table of the machinealso have different types of work. The table of the machine also have different types of adjustments. Thre are two general classes of upright drilling machine:
- ROUND COLUMN SECTION OR PILLAR DRILL MACHINE
- BOX COLUMN SECTION
RADIAL DRILLING MACHINE: The RADIAL DRILLING MACHINE is intended for drilling medium to large and heavy work pieces. The machine consists of a heavy , round and vertical column mounted on a large base. The column supports a radial arm which can raised and lowered to accommodate workpieces of different heights. The arm may be swing around to any position over the work bed.The drill head containing mechanism for rotating and feeding the drill is mounted on a radial arm and can be moved horizontally on the guide ways and clamped at any desired position. These three movements in a radial drilling machine when combined together permit the drill to be located at any desired point on a large workpiece, for drilling the hole. When several holes are drilled on a large workpiece, the position of the arm and the drill head is altered so that the drill spindle may be moved from one position to the other after drilling the hole without altering the setting of the work. This versatility of the machine allows it to work as large workpieces. The work my be mounted on the table or when the work is very large it may be placed on the floor.
PLAIN RADIAL DRILLING MACHINE: The Plain RADIAL DRILLING MACHINE also known as BACK GEARED FINE FEED RADIAL DRILLING MACHINE. In a Plain radial drilling machine provisions are madefor vertical adjustment of the arm, horizontal movement of the drill head along the arm and circular movement of the arm in horizontal plane about the vertical column
GANG DRILLING MACHINE When a number of single spindle drilling machine colums are placed side by side on a common base and have a common worktable, the machine is known as the GANG DRILLING MACHINE. . In a gang drilling machine four to six spindles may be mounted side by side..In some machines the drill spindles are permanently spaced on the work table..
DEEP HOLE DRILLING MACHINE: Special machines and drill are required for drilling deep holes in the rifle barrels, crank shaft, long shafts etc. The machine is operated at high speed and low feed. Sufficient quantity of lubricant is pumped to the cutting points for removal of chips and cooling the cutting edges of the drill. A long job is usually supported at several points to prevent any deflection. the work is usually rotated while the drill is fed into the work. this helps in feeding the drill in a straight path. In some machines both the work and the drill are rotated for accurate location.
AUTOMATIC DRILLING MACHINE: Automatic drilling machine can perform a series of machining operations at successive units and transfer the work from one unit to the other automatically, Once the work is loaded at the first machine, the work will move from onw machine to the other where different operations can be performed and the finsihed work comes out from the last uint without any manual handling.
MULTIPLE SPINDLE DRILLING MACHINE: The function of a multiple spindle drilling machine is to drill a number of holes in a piece of work simultaneously and to reproduce the same pattern of holes in a number of identical pieces in a mass production work. Such machines have several spindles driven by a single motor and all the spindles holding drills are fed into the work simultaneously. Feeding motion is usually obtained by raising the work table.But the feeding motion may also be secured by lowering the drill heads. The spindles are so constructed that their centre distance may be adjusted in any position as required by various jobs within the capacity of the drill head. For this purpose, the drill spindles are connected to the main drive by universal joints. Drill jigs may be used for guiding the drills in mass production work
SEMI UNIVERSAL DRILLING MACHINE: In a semi universal drilling machine, in addition to the above three movements, the drill head can be swing about a horizontal axis perpendicular to the arm. This fourth movement of the drill head permits drilling hole at an angle to the horizontal plane other than the normal position
UNIVERSAL DRILLING MACHINE: In a Universal Machine, in addition to the above four movements, the arm holding the drill head may be rotated on a horizontal axis. All these five movements in a universal machine enables it to drill on a work piece
at any angle.