Fundamentals of Lathe andDrill Machine.pptx

Fundamentals of Lathe andDrill Machine.pptx

1. Drill Machine

2. Introduction The process of drilling means making a hole in a solid metal piece by using a rotating tool called drill. The drilling machine is a single purpose machine for the production of holes and it is generally best method of producing holes. T wist drill is universally used for drilling.

3. T wist D rill

4. Twist drills usually have a taper shank, at the end which is fitted into the drilling machine having a tapered sleeve of matching taper . The drill has two lips at the other end where the cutting takes place, when the drill rotates. The angle between the two cutting lips is usually 118 °.

5. The chips formed at the cutting edges are automatically guided upwards through the helical grooves cut into the body of the drill These grooves are called flutes. This is necessary, otherwise, the chips will interfere with the metal cutting.

6. Classification of Drilling Machine Portable Drilling Machine Sensitive Drilling Machine Upright or Column Drilling Machine Radial drilling Machine Gang Drilling Machine  Multi-Spindle Drilling Machine Automatic Drilling Machine

7. Portable Drilling Machine It is a small compact drilling machine used principally for drilling operations which can be performed on a regular drill press . It is equipped with a small electric motor which gives power while working and is specified by the maximum drilling capacity.

8. Sensitive Drilling Machine Machines of this type are usually hand fed and operate on the principle of rack and pinion drive . The drill head is counterbalanced and fed through a hand lever system . This arrangement allows the operator to feed the force acting on the drill and hence the term ‘sensitive’.

9. Upright or Column Drilling Machine These are similar to sensitive drilling machines, except that they have power feeding mechanism for rotating the drill and are designed for heavier work . Generally these machines have box type column which is more rigid and consequently adapted for heavier work.

10. Gang Drilling Machine  Gang drilling machines have two or more drill heads mounted on the same table. These can be run either simultaneously or in sequence.  Spindles are lined in a row, driven either manually or by power . Such a machine is useful when a work piece is to have several operations performed, such as drilling, counter boring, reaming etc., or for drilling holes of several different sizes.

11. Multi-Spindle Drilling Machine These have been developed for the purpose of drilling several holes simultaneously. These machines are essentially production machines, and once set-up, will drill many parts, with such accuracy that all the parts are interchangeable. 

12. Automatic Drilling Machine These are used for high production work. These are built of a number of unit heads with single or multiple spindles in angular, horizontal or vertical positions in various combinations on a special base. Indexing table and work holding fixture at each station are also provided.

13. Radial drilling Machine It is the largest and most versatile of the drilling machines and is very well suited for drilling large number of holes . It is a single spindle machine intended for handling large and heavy work or work which is beyond the capacity of the small drilling machines . It consists of vertical column with a radial arm that can be swung through an arc of 180° or more.

14. Specifications Radial drilling Machine Maximum Drilling capacity in steel in mm Drilling capacity in cast iron Spindle Speed range Spindle feed range Spindle motor horse power Table size or working surface Overall dimension Net weight

15. Basic parts of Radial drilling Machine

16. Base It is the bottommost part of the radial drilling machine . It is made up of cast iron because cast iron has high compressive strength. The base is used to support the assembly of parts on it. It also absorbs the vibrations and shocks induced by the machine parts.

17. Column & Table Column is present at one end of the base. It is a vertical pillar which act as support for rotating the radial arm in 360 degrees . Table is mounted above the column. It is provided with T slots for mounting the work piece directly on its face. It is usually round or rectangle in shape.

18. Radial Arm This is the part which is connected to the column. This part can rotate 360 degrees around the column. The face of the radial arm is accurately machined and drill head slides over it. This arm goes up and down in the column. In big machines, hydraulics are used to move the arm up and down.

19. Spindle & Motor Spindle is the part of the drilling machine that holds the tool of drilling machine and is responsible for its rotation . The motor is present at the top of drill head which drives the horizontal spindle.

20. Drilling Machine Operations

21. Drilling Drilling is the most important and common drilling machine operation.

22. Boring Boring is a type of drilling operation in which we increase the diameter of the hole which was previously produced. 

23. Spot Facing In the spot facing, the surface around the hole is squared. In this process, that surface also gets finished.

24. Tapping In tapping, a tap is used for making internal threads. That means tap works as a cutting tool inside the tapping.

25. Counter boring In the counter boring , the end of the hole is enlarged cylindrically. A counter bore works as a tool in the counter boring .

26. Reaming The size of the hole after the drilling process may not be perfect. Most of the time, its internal surface may not be finished properly . T he internal surface of the hole gets appropriately finished with this process. Reamer is used for reaming. Reamer is a multi-point cutting tool.

27. Countersinking Countersinking is usually done to make a cone-shaped enlargement at the end of the hole. The included angle of the conical surface may be 60º to 90º.