ABRASIVE PROCESS AND BROACHING
1. What is broaching?
Broaching is a processes of machining a surface with a special multipoint cutting tool called ' broach' which has successively higher cutting edges in a fixed path.
2.Indicate any two specification of a broaching machine?
1.Maximum length of stroke in mm
2.Maximum force developed by the slide in tones
3.What are the advantages and limitation of broaching?
1.Roughing, semi finishing & finishing cuts are completed in one pass of the broach 2.Broaching can be used for either external or internal surface finish
1.High initial cost of the broach tool compare to other tools
2.Job work or batch work is not advisable due to the high tool cost.
4.What are the different operations that can be performed on a broaching machine?
2.Broaching a key way
5.What are the advantages of gear planning process?
Any given module can be cut using a single cutter.
The rate of production is higher when compared to forced cutter method. It is a simple flexible and accurate method of generating gears.
6.What are the limitations of gear hobbing?
1.Internal gears cannot be generated.
2.Hobbing process cannot be applied very near to shoulders
7.State the purpose of grinding?
1.To remove small amount of metal from work pieces & finish then to close tolerances.
2.To obtain the better surface finish.
The machining accuracy of holes produce by this machine tool lies with in a range of 0.0025 mm.
8. Define the term “grade” used in grinding wheel?
Grade or hardness indicates the strength with which the bonding material holds the abrasive grain in the grinding wheel.
9. What is meant by dressing &truing?
The process of loading &breaking away the glazed surface so that new sharp abrasive particles are again present to work for efficient cutting is called dressing.
Truing is a process of trimming the cutting surface of the wheel to run true with the axis.
10. What is process of lapping?
Lapping is a surface finishing process used for producing geometrically accurate flat, cylindrical &spherical surfaces.
11.What are the three types dividing heads?
1.Plain or simple.
12.What are the other forming methods for manufacturing gears?
1.Gear cutting by single point form tool. 2.Gear cutting by shear speed shaping process. 3.Gear broaching.
13.List the gear generating process?
1.Gear shaping process.
2.Gear planning process.
3.Gear hobbing process.
14.Mention the applications of gear shaping process?
1.Gear shaping used for generating both internal & external spur gears. 2.Helical gears can
also be generated using special attachments.
15.What are the limitations of gear hobbing?
1.Internal gears cannot be generated.
2.Hobbing process cannot be applied very near to shoulders.
16.What are the advantages of gear planning process?
1.Any given model can be cut using a single cutter.
2.It is a simple flexible &accurate method of generating gears.
17.List the various gear finishing processes?
1.Gear shaving. 2. Gear burnishing.
2.Gear grinding. 4.Gear lapping.
18. How the centre less grinder operates?
The centre less grinder operates with two wheels as the cutting wheel, to remove the excess stock and a regulating wheel which is used to control the speed of rotation of the work and the rate of feed.
19. What are the advantages of centre les grinding?
The work pieces are suppressed through the wheels
No tendency for chatter and deflection of the work piece. Easy size control of the work.
No need of chucking or mounting of the work piece.
20. What is honing?
Honing ids also a surface finishing process like grinding, which uses a “hon” tool that consists of stones to abrade the metals.
21. What is meant by polishing?
Polishing is the surface finishing operation performed by a polishing wheel, for the purpose of removing appreciable metal to take out scratches, hole marks, Pits and other defects from rough surfaces.
22. What is meant by buffing?
is used give much high lustrous, reflective finish that can not be obtained by
polishing. The buffing process consists of applying a very fine abrasive with