1. Lecture 02 Assembly Automation Vibratory Feeders

2. Introduction Vibratory feeder Mechanics of Vibratory Feeder

3. Force acting on vibratory feeding

4. for sliding up the track to occur Where condition for forward sliding up the track to occur is, therefore, given by combining Equation Similarly, it can be shown that, for backward sliding to occur during the vibration cycle (Eq: 1) (Eq: 2) (Eq: 3) (Eq: 4)

5. Normal track acceleration The operating conditions of a vibratory conveyor may be expressed in terms of the dimensionless normal track acceleration A n /g n, where A n is the normal track acceleration (A n = a n ω 2 = a 0 ω 2 sin ψ), g n the normal acceleration due to gravity G n =(g cos θ), and g the acceleration due to gravity (9.81 m/sec2) (Eq: 5)

6. Substitution of Equation 5 in Equation 3 and Equation 4 gives, for forward sliding, for backward sliding The limiting condition for forward conveying to occur is given by comparing Equation 6 and Equation 7. Thus, for forward conveying Force acting on vibratory feeding (Eq: 6) (Eq: 7) (Eq: 8)

7. With sufficiently large vibration amplitudes, the part will leave the track and “hop” forward during each cycle. This can occur only when the normal reaction N between the part and the track becomes zero. and, therefore, for the part to leave the track, Force acting on vibratory feeding (Eq: 10) (Eq: 9)

8. For μ s= 0.8, θ = 3 deg,Ø=30 deg find An/gn for forward sliding and backward sliding

9. Limiting conditions 4.7 1 0.34 0.8

10. Effect of various parameters On conveying velocity (v m ) where fv m =constant Frequency (f) Track Acceleration (A n /g n ) Vibrating angle ( ψ) Track angle ( θ) Coefficient of friction (µ)

11. Frequency & track acceleration

12. Vibration angle

14. Track angle

15. Coefficient of friction

16. Typical part motions

17. Effective length of the hop (J)

18. Effective height of the hop(H)

19. Load sensitivity

20. Solution of load sensitivity Load detector switch Modification to the feeder By changing spring stiffness Use on/off control Sensor control

22. Spiral elevators

23. Balanced feeders

24. Orientation of Parts Active Orienting devices-reorientation Passive Orienting devices-rejection base -In bowl -Out bowl

25. Passive-in bowl

26. Typical Orienting systems

27. Orienting systems- Washers

28. Orientation – Machined washer

29. Orientation – cup shaped parts

30. Orientation – truncated cones

31. Orientation – U-shaped parts

32. Orientation – narrowed track

33. Wall projection and narrowed track

34. Active Orienting systems

35. Analysis of orienting systems

37. Natural resting aspect

38. Probability of orientation

39. Natural resting aspect Assumptions Surfaces can be divided in to two categories Soft surfaces Hard surfaces Probability that the part come to rest in a particular natural resting aspect depends on two factors Energy barrier tending to prevent a change of aspect Amount of energy possessed by the part when it begins to fall Parts are being dropped from sufficient height

40. Natural resting aspect

43. Out-of-Bowl tooling