356 Machine Drawing
dharm
d:\N-Design\Des19-1.pm5
(iii) Draw the main outlines and add all the internal features.
(iv) Cross-hatch the sectional views.
(v) Draw the dimension lines and add dimensions and notes.
7. Check the dimensions of the mating parts.
8. Prepare the parts list and add the title block.
Exercises
Prepare the part drawings of the engine parts, machine tool parts and accessories and miscellaneous
parts shown in Figs. 19.1 to 19.22.
19.2 Engine Parts
19.2.1 Petrol Engine Connecting Rod
Figure 19.1 shows the assembly drawing of a petrol engine connecting rod, the big end of which is
split into two halves. It is used in center crank engines.
The bearing bush 4 which is in one piece, is fitted at the small end of the connecting rod 1.
The small end of the rod is connected to the piston. The main bearing bush, which is split into two
halves, is placed at the big end of the connecting rod. The big end of the rod is connected to the
crank pin of the center crank. First, the split bearing brasses 3 are placed on the crank pin, then
the big end of the connecting rod and the cap 2 are clamped onto these, by means of two bolts 5 and
nuts 6.
6X62M6(^12) R62
R25 R25
R20
195
R75
f 22
X
f 19
f 30
R25 28
25 20
5
2
9 17 12
3
36
R40
38
f 35
f 38
f 44
R40R40
30
3 1
X–X
12 3
4
DIA4,
DRILL CSK
R18
f 19
f 22
f 26
Parts list
Part No. Name Matl. Qty.
1 2 3 4 5 6
Rod
Cap
Bearing brass
Bearing bush
Bolt
Nut
FS
FS
GM
P Bronze
MCS
MCS1 1 2 1 2 2
28Fig. 19.1 Petrol engine connecting rod