OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Fig 2 shows the actual photograph of a connecting rod. The past data of percentage of rejected conrod during
different machining processes for a six month period has been shown in Fig 3.
e
g
a
%
1.5
1.3
1.1
0.9
0.7
0.5
0.3
0.1
- 0.1
1.01%
0.19
0.25
0.57 0.48
0 0
0.16
1.31%
1.15%
0.25
0.17
0.75% 0.81% 0.26 0.33
0.1
0.11 0.11
0.16
0.44 0.72 0.73 0.36 0.55
0 0
MAR APR MAY JUN JUL AUG AVG.
TOTAL 1.01 0.75 0.81 1.15 1.31 0.86 0.98
OTHERS 0.19 0.11 0.1 0.17 0.25 0.24 0.18
FINE BORING 0.25 0.16 0.11 0.26 0.33 0.13 0.2
HONING 0.57 0.48 0.44 0.72 0.73 0.36 0.55
DDG 0 0 0.16 0 0 0.13 0.06
Fig 3. Percentage rejection of connecting rod
0.86% 0.98%
0.13 0.06
To identify the root cause of conrod rejection, it was necessary to collect data of its manufacturing process. As
we see in Fig 3, 55% of data rejection was at Honing process. For the same period of six months Honing process
data was collected for analysis as shown in Fig 4.
0.24
0.13
0.18
0.2
L
O
T
S
I
Z
E
1000
800
600
400
200
0
66%
658
Sizing P lug
Rough
87%
206
Sizing Plug
Semi F inish
94% 98% 100%
69
36 23
Ledge Setting setting Taper
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Fig 4. Rejection Contribution by different process during Honing
As it is clearly visible from Fig 4, 87% of rejection could be attributed to processes of sizing plug rough and
sizing plug semi finish. Data on quantity of rejected conrod during study period for the above said processes
were collected as shown in Fig 5.
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