It is the simplest and accurate machine used in production shops. The workpiece is held stationary i.e. clamped in position and the drill rotates to make a hole. Drilling is basically a simple purpose machine tool as its main purpose is to make holes in the workpiece.
Drilling Operation
Drilling is the operation of production circular hole in the workpiece by using a rotating cutter called a drill. The machine used for drilling is called drilling machine.
Operations performed by Drilling Machine
1. Drilling: Drilling produces holes in an object by forcing a rotating drill tool against work(drill press) or forcing a stationary drill against a rotating work(as a lathe machine).
2. Boring: This is the operation of enlarging a hole already drilled or cast. It produces more accurate (true) holes than drilling. It is internal turning operation producing different types of revolution.
3. Reaming: A reamer enters the workpiece axially and enlarges an existing hole to the diameter of the tool. Reaming removes a minimal amount of material and is often performed after drilling to obtain both a more accurate diameter and a smoother internal finish.
4. Threading: Threading is an operation of making helical grooves in a workpiece. It is usually done using a tool on a lathe machine.
5. Counter Boring: A counter bore tool enters the workpiece axially and enlarges the top portion of an existing hole to the diameter of the tool. Counter boring is often performed after drilling to provide space for the head of a fastener, such as a bolt, to sit below the surface of a part. The counter boring tool has a pilot on the end to guide it straight into the existing hole.
6. Counter Sinking: A counter sink tool enters the workpiece axially and enlarges the top portion of an existing hole to a cone-shaped opening. Counter sinking is often performed after drilling to provide space for the head of a fastener, such as a screw, to sit flush with the workpiece surface. Common included angles for a counter sink include 60, 82, 90, 100, 118 and 120 degrees.
7. Tapping: A tap enters the workpiece axially and cuts internal threads into an existing hole. The existing hole is typically drilled by the required tap drill size that will accommodate the desired tap. Threads may be cut to a specified depth inside the hole (bottom tap) or the complete depth of a through hole (through tap).
Component parts of Drilling Machine
1. Bed: The bed is the main part of the machine on which the whole machine is being mounted. The bed is made up of cast iron, so it has high compressive strength and good wear resistance.
2. Pillar: The pillar is a type of vertical column that rests on the bed. Pillar is present at the center of the bed. Pillar helps the motor and the spindle head.
3. Swiveled Table: The table is the place where the workpiece is being mounted. The table is attached to the column and it can be rotated around the column and can have an upward and downward moment. A table can be adjusted at any angle as per the requirement.
4. Motor: The motor is present at the top of the column. Inside motor shaft is there which connected to a stepped pulley so that we can increase or decrease the speed of the rotation of the motor.
5. Stepped pulley: Two stepped pulleys are present on either side of the column at the top. Out of these two, one pulley will be an upward direction while the other pulley is inverted. Always both the pulleys will be there in the opposite direction. The basic function of the stepped pulley is to control the speed of the rotation of the motor.
6. Spindle: Spindle arrangement is present at top of the column opposite to the arrangement of the motor. The top of the spindle is attached to one of the stepped pulleys. The bottom of the spindle is connected to the chuck.
7. Chuck: Chuck is present at the bottom of the spindle. The basic function of the chuck is to hold the cutting tool firmly.
8. Drill bit: A drill bit is an actual cutting tool that is used to create a hole in the workpiece.
9. Hand wheel: The basic function of the hand wheel is to adjust the spindle position as per the requirement.
Advantages of drilling machine:
1. High speed
2. High output
3. Easy to operate
4. High flexibility
5. Low maintenance and lower cost
Disadvantages of drilling machine:
1. Limited size workpiece
2. Rough hole
3. Chipped cutting lips
4. Oversized holes
5. Breaking of drill
Hi. I’m Designer of Blog Magic. I’m CEO/Founder of ThemeXpose. I’m Creative Art Director, Web Designer, UI/UX Designer, Interaction Designer, Industrial Designer, Web Developer, Business Enthusiast, StartUp Enthusiast, Speaker, Writer and Photographer. Inspired to make things looks better.
0 comments:
Post a Comment
If you have any doubts about study. Please let me know