fig. 1
The firing order is a sequence of giving spark/firing to the cylinders of multi-cylinder inline engines. Firing order is provided in multi-cylinder inline engines in order to avoid vibrations (If firing order is not provided in multi-cylinder inline engines, then all the pistons will move in upward direction at the same time and same way they move in the downward direction at the same time. This creates a lot of vibration.) For avoiding these vibrations, firing order is provided in multi-cylinder inline engines.
Numerical
Solution:
Given data:
The force and couple data is given in table:
Plane | Mass (m), kg | Radius (r), m | Centrifugal Force (m x r), kg.m | Distance From R.P.(l), m | Couple (m x r x l), kg.m ^{ 2 } | Primary Crank Position ' θ ' | Secondary Crank Position '2 θ ' |
---|---|---|---|---|---|---|---|
1 | 1.5 | 0.05 | 0.075 | -0.3 | -0.022 | 0° | 0° |
2 | 1.5 | 0.05 | 0.075 | -0.15 | -0.011 | 576° i.e. 216° | 1152° i.e. 72° |
3 (R.P.) | 1.5 | 0.05 | 0.075 | 0 | 0 | 432° i.e. 72° | 864° i.e. 144° |
4 | 1.5 | 0.05 | 0.075 | 0.15 | 0.011 | 144° | 288° |
5 | 1.5 | 0.05 | 0.075 | 0.3 | 0.022 | 288° | 576° i.e. 216° |
fig.2 (a) Position of planes
fig.2 (b) Primary crank positions
For drawing a primary force polygon, take a suitable scale of 1 cm = 0.075 kg.m. From fig.2(c) it is seen that, primary force polygon is closed and hence there is no unbalanced primary force.
fig.2 (c) Primary force polygon
fig.2 (d) Primary couple polygon
fig.2 (e) Secondary crank positions
fig.2 (f) Secondary force polygon
Draw the secondary force polygon by taking a suitable scale of $1 \ cm = 0.075 \ kg.m$. From fig.2 (f), it is seen that the secondary force polygon is closed, hence there is no unbalanced secondary force.
fig.2 (g) Secondary couple polygon
Draw the secondary couple polygon by taking suitable scale of $1 \ cm = 0.011 \ kg m^2$. The vector $\overrightarrow {od'}$ represents the unbalanced secondary couple ${C_s}$
Now from fig.2 (g), measure $\overrightarrow {od'}$;
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