Grinding machine | Interview Question and Answers
Grinding machine | Interview , VIVA ,Oral Question and Answers
1.What is meant by Grinding?
Grinding is a metal removal process or operation performed by means of rotating abrasive wheel that acts as a cutting tool against the work piece.
2.Why is grinding called finishing process?
Grinding is called finishing process, because the grinding process removes metal usually in the order of 0.25 to 0.50 mm. Which produces very high quality surface finish.
3.What is the approximate thickness of metal removed in grinding operation ?
The approximate thickness of metal removed in grinding operation is 0.01 to 0.03 mm.
4.What are the main types of grinding?
The two main types of grinding are:
a) Rough or Non-precision grinding, b) Precision grinding.
Read More : Types of Grinding Machines -LearnMech
5.What are the different types of rough grinders?
a) Floor stand and bench type grinders b) Portable and flexible shaft grinders c) Swing frame grinders d) Abrasive belt grinders.
6.What are the types of precision grinders?
a) Cylindrical grinders b) Internal grinders c) Surface grinders d) Tool and cutter grinders e) Special grinding machines
7.What is surface grinding?
Surface grinding is the process of producing and finishing flat surfaces by means of a grinding machine using a revolving abrasive wheel.
8.What are the types of surface grindings?
The different types of surface grindings ate:
1. Reciprocating table surface grindings – a. Horizontal type b. Vertical type.
2. Rotating table. – a. Horizontal spindle b. Vertical spindle.
9. What types of work can be ground by a surface grinder?
Surface grinder can be used for flat surface, irregular surface, curved surface, tapered surface, convex surface and concave surface.
10. What are the types of internal grinders?
The different types of internal grinders are:
1. Chucking grinders
a) Plain b) Universal
2. Planetary grinders 3. Centreless grinders
11. What is the use of internal grinders?
Internal grinders are used to finish straight, tapered, or formed holes to correct size, shape and finishing.
12. What are the different types of external grinders?
External grinders are divided into
a) Plain cylindrical grinders
b) Universal grinders
c) Special grinders such as the centre less grinders.
13. What are the uses of external grinders?
External grinders are used for grinding cylindrical surfaces and to produce external cams eccentrics and special form on the outside diameter of the work.
14. List out the surfaces ground by the plain cylindrical grinder?
External cylinders, tapers, fillets, undercuts and shoulders are some
a) The head stock spindle may be used alive or dead.
b) The headstock can be swiveled at an angle in horizontal plane.
c) The wheel head and slide can be swiveled and traversed at any angle.
15. Explain briefly; the meaning of centre less grinding?
Grinding the diameter of the work piece without mounting on centres is known as centre less grinding.
16. What are the operations done in centre less grinders?
The various operations are:
a) Through feed grinding b) In feed grinding c) End feed grinding
17. What are the main disadvantages in centre less grinding?
The main disadvantages are:
a) The hollow work cannot be grinded
b) The work having multiple diameters is not easily handled.
18. How does the centre less grinding operate ?
The centre less grinding operates with two wheels as the cutting or grinding wheel, to remove excess stock and a regulating wheel is used to control the speed of rotation of work and rate of feed.
19. Why is the centre less grinders called specialized machine for Cylindrical parts?
Centre less grinders are called specialized machine for cylindrical parts because it was developed form the rapid production of cylindrical, external taper, or external profile work.
20. What are the advantages of centre less grinding?
The advantages of centre less grinding are:
a) The work piece is suppressed through the operations.
b) No tendency for chatter or deflection of work
c) Easy control of the size of the work
d) No need of chucking or mounting.
21. What are the types of wheel that are mounted on way grinders?
Cup, Ring or segmented wheels are the wheels that are mounted on vertical spindle of a way grinders.
22. What are the work holding and supporting devices used in grinders ?
Work holding and supporting devices include:
a) Steady rest for cylindrical grinders.
b) Chucks and fixtures for other grinders,
c) Magnetic chucks used particularly on surface grinders.
23. What are the two types of magnetic chucks?
a) Electromagnetic chuck b) Permanent magnetic chuck.
24. What is the use of magnetic chuck in surface grinding?
The magnetic chuck helps in firmly holding the workplace without any distortion due to pressure of the jaws, which is undesirable. Magnetic chuck is used for holding a very thin work piece, made of magnetic material. Moreover more number of similar work piece can be conveniently located on the surface for simultaneous grinding.
25. How are the non-ferrous metals held in magnetic chuck?
Non-ferrous metals may be held on a magnetic chuck by clamping them in suitable fixtures made of iron or steel by exhausting air from a vaccum chuck.
26. What are the attachments used in grinding machines?
The different attachments are:
a) Equipments for contour grinding
b) Attachments to improve grinding results
c) Measuring and sizing device
27. What is meant by measuring and sizing devices?
The measuring and sizing devices range from simple measuring devices to continuous reading gauge, which actually control the feeding of the machine.
28. What are the attachments used to improve grinding results?
The attachments include wheel reciprocating attachments for better finish, ultrasonic cleaning devices and electrolytic attachments to aid in grinding extremely hard materials.
29. What is meant by dressing of grinding wheels?
Dressing of the grinding wheels refer to conditioning the face of the wheel for the operations to be performed ,like opening the face for free cutting, smoothing the face for finishing and removing and load from the free face.
30. What are the different types of fine finishing process?
Milling, super finishing, polishing, buffing, metal spraying,galvanizing and electroplating are the fine finishing process.
31. What is honing?
Honing is a machining process similar to grinding, used to finish a fine before surface.
32. How does honing differ from grinding?
Grinding machines run at high speeds and pressure, which results in high temperatures. But, Honing requires slow speed and low-Pressure, which keeps surface temperature relatively low.
33. What are the materials normally be worked by the Honing process?
Steels of all varieties, Cast iron, aluminum, magnesium, brass, bronze, glass, ceramics, hard rubbers, graphite etc., are few examples honing.
34. Give the product applications of lapping?
Lapping is done as precision tools, gauges, valves and on other similar places, where resistance to wear of moving parts, better sealing characteristics and longer life of cutting edges are preminent factors.
35. 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.
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