Drilling Machine

Drill Bit:    Drill bit, usually a rotatory cutting tool (attached to the machine) which forces the cutting edge against the workpiece and cutting off iron chips (scrap or also swarf) from the hole when it is drilled. 

Drilling Machine: A portable power tool which is used to cut around hole into / or through metal, plastic, wood or other solid materials through rotatory frill bits into a workpiece.

    In rock drilling, the hole is usually not made through a circular cutting motion, though the bit it is usually rotated. Instead, the hole is usually made by hammering a drill bit into the hole with quickly repeated short movements. 

    the hammering action can be performed from outside the hole (top-hammer drill) or within the hole (down-the-hole drill, DTH). Drills used for horizontal drilling are called drifter drills.

Components of Drilling Machine

• Base: Base is generally bolted or fitted with the ground to support the weight of drilling machine.
• Column: Column is located on one side of the base, which can carry the load of the arm and drill head, with a sliding table mounted on it.
• Arm: At the top of the column, which carries the drill head and the housing of the driving mechanism is called as arm.
• Drill head: Drill head is mounted on one side of the arm, consists of feed and driving mechanism. It can slide up and down.
• Worktable: Worktable is mounted on the column, can move vertically and horizontally as per the requirement.
• Feed mechanism: Feed mechanism is hand and automatic feed by an electrical motor. A drilling machine for tapping a pipe includes a rotatable boring bar which is advanced linearly by a ball bearing nut and screw combination, the nit being fixed to the boring bar and the screw being rotated by a power source.
  

  Drilling Machine

• Spindle: Spindle is a circular taper shaft which helps to hold the drill chuck. It is made of high carbon chromium steel or SS or steel alloys.
• Chuck: A chuck is an attachment clamp-like that holds the drill bit or other tools used in drilling equipment. It is situated on the spindle, that holds the drill jig.
• Electric Motor: In a drilling machine, single phase AC motor is used which can run at 600-5000 RPM or may be more for high duty drilling machine.
  

Working of Drilling Machine

1. Portable drilling machine (Hand drilling machine): Portable drilling machine is generally small in size and contains a universal motor, used for drilling holes on the rocks or any rigid surface, suitable for any location. The piece to be drilled is held in a vice.
2. Sensitive drilling machine (Bench drilling machine): Sensitive drilling machine is perfect for producing small holes at high speeds, usually consists of a base, worktable, spindle, drill head, driving mechanism and column. The work is started from the drill fed into the piece by hand.
3. Radial drilling machine: Redial drilling machines are mainly for drilling large and heavy workspaces, the table can be adjusted to suit different heights. It allows the operator to make the spindle directly over the workpiece rather than move the part to the tool, and also capable to create intersecting or angular holds in one setup. 
4. Upright drilling machine: Upright drilling machines are larger and stronger than sensitive drilling machine, designed for handling medium to large-sized holes.
5. Gang drilling machine: Gang drilling machine can be used for drilling, reaming, counterboring and tapping, just need to move the machine back and forth.
6. Deep mole drilling machine: Deep mole drilling machine is a special type that is designed to drill deep holes in the connecting rods, spindles and others, with high cutting speed and less feed.
7. Multiple spindle drilling machine: Multiple Spindle drilling machine is with several spindles, perfect for drilling a large number of holes into a part and drilling same holes on identical workpieces. 
8. CNC Drilling machine: Computer Numerical Control drilling machine can automatically change tooling with a turret or automatic tool changer. The program controls the speeds, feeds & table position and complete work with good finishing.
9. Micro drill press: Micro drill press is extremely accurate, high spindle speed, used to handle tiny or very small parts. 
10. Turret type drilling machine: Turret type drilling machine is equipped with several drilling heads mounted on a turret, the tool can be quickly indexed into position.

Hazards of Drilling Machine

Hazards are as follows:

• Injury or cut from flying or rotating scrap which comes out during drilling.
  

Drilling Scrap

• Electric shock or spark if not connected properly.
• Hand Vibration syndrome (i.e., physical hazard) after prolonged use.
• Metal dust which may inhaled by workers.
• Cutting oil during drilling process.
• Back pain after prolonged drilling while sitting at one place (As per Ergonomic hazards, Musculoskeletal Disorder).

Safety Precautions

• Drilling is considered as hot work. Hence, work permit must be taken prior work commence.
• Toolbox Talk to be given by company’s Safety Officer before assign such drilling tasks.
• Worker should not do horseplay with such power tools to avoid injury.
• Proper work permit to be ensured when drill to be conducted in confined space also.
• The spindles, chucks as much of tools as possible should be guarded.
• It should be ensured that all set screws are recessed.
• No neck ties, lose or flapping clothing, long hair styles, or finger-ring should be not allowed which leads to near miss or incident.
• Spindle or chucks should not be stopped by hand. Such horseplay to be avoided.
• The work always be clamped securely to table to promote safe work practices.
• One should never attempt to hold work by hand while drilling.
• If work piece skips from the clamp, then operator should stop machine at that same time.
• Properly sharpened drills should be used and should be ensured that they are running to avoid broken or splintered drills.
• Correct speed should be selected, avoid horseplay and drill should be never forced or fed too fast.
• Never make any adjustments while the machine is operating or rotating.
• Never clean away chips with your hands. Use brush or broom.
• Keep all loose clothing away from turning tools to avoid injury or near miss.
• Make sure that the cutting tools are running straight before starting the operation.
• Never place tools or equipment on the drilling tables, such habits violate 5’S’ principles.
• Keep all guards in place while operating.
• Ease up on the feed as the drill breaks through the work to avoid damaged tools or workplaces.
• Ensure housekeeping (i.e., cleaning, and securing of tools, wires, extension boards, electrical sockets, etc.) after completion of work to maintain electrical safety also.
• Remove all chink keys and wrenches before operating the machine to maintain industrial hygiene.
• Always wear goggles (i.e., Personal Protection Equipment) while operating any drilling machines.
• Keep doing stretching exercises after prolonged work.