at 2352 chassis components design university qp
TRANSCRIPT
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7/25/2019 AT 2352 Chassis components design University QP
1/14
.
,','-'
ll'Il"rD.Tech'
I)BCIRttli
IIX./LMII\lATlO.htr.
N0vtilv{iiIilli.ri.)i:liti.ti,iitiiii
3(}1-}"r.
Sixlli
Serncstcr.
Au
tor:robile
Engin+ering
,.T
I
3 S
1
_*
hUTO
IvIOTIVE
Ct{"AriSIS
D
i1:$
if.t
},1
(Regulat.iou
2004)
Tirne
:
Three
hours
fi'lttximur;:
: 100
:narlis
Answctr
ALL
guestions.
PART
r\'
(10
x
2
=
2A
rnarlis)
1.
.
$/[r:rt.
hsppens
if.ii:e
cillrnrete,
of
thc
driven plate
is
i,cr.ee.scd'l
Z.
Why
is
'
cone
cltrtch
,r,oro
ofto.ti.rc than
piate
clulch
?
;r.
3.
lVhat
is the
conditiori
for
maximunr
tracLiorr.l
z'
t
4.
Ho.r
are
intermcdiate
gears
decidcd?
6.
Wh.st
ure
thc loadg
and strcsscs
ihe
franrc,
hns
to
rvithsfand?
6.
,
what
is
the
eliect
ola
camber
ect
give'
to
cnch
rcaf-springl
7
.
Wrut,
a.ra
the
type
of strcsses
encountod by
fronl
*rJci.
B.
lYJrat
are
nra-in
causcrccd
r1{rrltion
o.
r"un*u.
?op
5.1
,r,
ir*t*r=1ll]':f",r-ii
to
pro'iclr
t}re
ill
f
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ff
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es
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l
r-r:.+
r'a""n,
a,,,
r.,-,,,,,.,,,
rr:ru'
lrrlarinl;r;
of
rr
4
rspeccl
gcnr
l;ox,
r,rbcn
2iiri
1?
(a)
calctrlatc
lhq
maxmum
be'ding
*roraent,
&i:d
rnorimu::i
section
rnodulus
ssuming
thc
follorving
particrrllr:.
\\tcel
base
=
lBC
cm
:
Ovcrall
length
=
860.
cm
[:,1ual
ovcr.liang
on
aither
nide.
2',l00
N
acti,g
ar
c'G'
of
load
45
cr'in
froul
or.front
r*ci.
1BC,
N.
^cLinJ;
at
C..G
of
load
46
cnr
U",,,,,,
,.ru,;;;;;;
I800
N
acling
ie
c.'c
of
lo*d
45 crn
in front
c,f
rc&r
*vJs,
6?5
I{
ncting
;,,"'i.-:.(}
ol.loacl
45 cm
Lrehilri
tlc
rerrr
ax,lc.
::;f
i::?f:l;;:i:jl:'J,,,
die,-ribured
road
or
1.75
Nlnrin
r,,
ov*
rhc
Anrrrnrrr
rjynanric
o[rcss
ie
l,u,ice
l,irc
st-a.Lic
sLrcas
inclur:ed.
i"acl.,
ori
flr-ont.
rlnrl
g;eni'
is
in
cngrrgenieat.
Or'
C
BOOB
-
7/25/2019 AT 2352 Chassis components design University QP
10/14
"
r$
B
E
,:
':,
11,
.1;
'l
h)
,z{tnrsion
-
bar suspension
is to be
dcsigued
to
support
a
rnaximum
static
/
Ioad
of
B4S3.S
N
at
the
end
of
a
lever
arm
250
nlm
long.
'Ihe
deflection
of
the
lever
above
the
horizontal
is
to
be
30'rvith
a
total
angle
ofdeflection
of
90o.
Assuming
a
safe
nllowable
stress
of
?84800
liPa,
cillculate
(r)
The
diameter
of
torsion
bar
(ii)
1'he
effective
iength
and
(iii)
Thc load rate.
The
load
distribution
between
the
front
and
the
near
a-de
of a
moi'or
vehicle
rveighing
1450
kgs
is
tbat
46?o of
thc
total load is
taken
by
the
front
axle.
The
viidth
of the
track
is
140
cm
and
the
distance
betrveen
the
ccntres of
the
spring
pads
is
66
cm.
Design
a suitable
I-Seqgion
for
[ re
froni
axle
assuming
that
the
rvidth of the
flange
and
its thiclcness
are
Q.6
and
0.2
of the
o'rerall
depth
of
the
section
respcctivcly
and
thc
tirickness
of
the
rveb
0.25
of
width
of the
{lange
. Assume
a
worldng
strcss
of 915
kgflcm2.
t:
.
l,'
.
ir:
,i.
f.
r.;
;r
i?--
axlc
'ot
\.,
r
ehaft
ie Lo be deeigned
for
a full floating
ncsr
o'xlc.
Givcn:
Maximum
cngine
Lorque
=
Rear
axlc
ratio =
190
Nrrr
5:l
4:1,2,5;L,1.4:1
ear
ratios
Pcrnriasible
ahoar
stregs for
axlo
ghafL
mstcrial
is
Calculal.e
the
dismetsr
of
tlro
uxle shaft.
and
1:1
13734 N/rn2.
XloT
/,
.,/
t
li
l"
r4?).d
,/
Or
,/G
f6
'
X cary
has
pivot.
pins
f
.Ia
m
apart,
l.he
lcngth;pf
euch
trtrclc
itrttrs
'is
O.f6IO
m
and
the
trick
rod
behind the
axlo
is
1.64
ru long.
I)ctc::mi:ic
'
the
whcelbgso
for
true
rolling
of all
wheels
when
the inner
rvhecl stu[r
axle
is
at 55"
to
thc
bcrrlrs
tirao
of
tb.e car.
15.
(a)
An
automobilc
cnginc
devclops
30
krv
at
1500.r.p.m
and
its
bottom
gear
,
n
.
ratio
is 3,06.
It
a
propeller
shaft
pf
40
mnr.outside
dianrctcr
is
to be
uscd,
.
deLermine
thc
inside diameter
of
mild
B-tecl
tube
to
be
uscd,
assurning
n
safe
shear strcss
of
55
x
1C3
l
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7/25/2019 AT 2352 Chassis components design University QP
11/14
Reg.
No.:
J
8053
B.E./B.Tech.
DEGREE
DGMINATION,
I\,IAY/JUNE
2009.
Sixth
Semestr
Automobile
Engineering
AT
1351
-
AUTOMOTTTru
CIIASSIS
DESIGN
r
(Regulation 2004)
Time
:
Three
hours
Maximum
:
100
marks
Answer
ALL
questions.
PARTA-(10 xZ=2}marks)
1.
why
is
a clutch
needed
in
an
automotive
transmission
system?
2.
What
are
overrruuring
clutehes?
List out
the
variouscesistances
that
a
vehicle
in
motion
has
to encounter
and
briefly
explain
them
Why
is
geometric
progression
preferred
in
gear
ratios?
Give the reason
for
the wide
use
of channel
section
with its web
in
vertical
orientation,
for
the
side members
of
eornrnercial
vehicles.
Why
are
ghackles
used
along with
leaf
springs?
What
are
the
different
sections
used
in
a rigid
type
front
a:rle
of
a
commercial
vehicle.
Justi$
the
usage
of
these
sections.
Iflat
is
meant
by steering
etror cunre?
What is its
use
in
the
design
of
steering
linkagee?
Why
is
hollow
shaft
uaed as
propeller
ahafts?
/
Hon,
are the various
reaction. forrces
and
torques
takeu care in
a Hotch
kise
drive?
3.
4.
5.
6.
7.
8.
9.
10.
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7/25/2019 AT 2352 Chassis components design University QP
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PARTB-(5x16=80marks)
11.
(a)
Calculate
the inner radius
and outer
radius
of
the friction
lining
of a
single
plate
two
sided
dry
B?e
clutch
and
the axial
spring
thrust
exerted
by
the
cluteh
springs
to keep
it
engaged
from the
following
data
:
Maximum
torque transmitted
=
13.56
Nm
Co-bfficient
offrictionsurface
=
0.8
Ma:cimum
axial
pressure
=
8.2g
x10a
Pa
External
radius
of
friction
surface
=
L.25 times
internal
radius.
L2.
(a)
Or
A
cone
clutch
with
cone
angle 20"
is
to
transmit
?.80
kw at
7b0
rpm.
The
normal
intensity
of
pressure
between
the
contact faces
is
not
to
exceied 11.8 x10a
N/m2.
The co-efficient
of
frietion
is
0.2.
If
the
face
width
is
U5 of
the mean
diameter
find out
the main
dimensions
of the clutch
and
the
axial force
required
while
running.
The
co-efficient
of
rolling
resistance
for
a
truck
weighing
OZ2gB.b N
is
0.018
and the
co-efficient
of air resistanee
is
0.02?6
in
the formula
R= kW
x
IG
A\P Neutons
where
A is
the
projected
frontal area in m2
and
V the
speed
in
km/hr,
and Y
is
the
weight
of
the
vehicle. The
transmission
efficiency
in
top
gear
of
6:2:1
is
90vo and
that in
the
second
gear
of
15:1
is 80Vo.T\e
projected
frontal
area of
the
truck is b.b?4 m2. If
the truck
has a
maximum
speed
of 88
km/hr
in top
ga,
calculate :
(i)
The
engine
brake
power
requires.
(ii)
The
engine
speed
if the driving
wheels
got
an
effective diameter
of
0.8125
m.
(iii)
The
maximr:m
grade
the truck
can
negotiate
at the above engine
speed in
second
gear.
Or
(b)
Determine
the
gear
ratios
for
a
four
speed.
gear
box for a vehicle of
weight
13341.6
Newtons
powered
by
an engine
giving
20.6
kW at 1800
rpm.
The
vehicle
has
a projected
frontal
area
of
2.23m2
and has an
effective wheel
disrneter
0.71m.
the
maximum
gradient
that the
vehicle can negotiate is
1 in
4. The
tractive
effort
may
be
taken
as 50
Newtons
per
224A Newton
weight
of
the
vehicle.
The
wind
resistance
is
given
by 0.036?9
A\P,
where
A
is
the
projected
frontal
area
in m2
and
%
the vehicle
speed
in ka/hr.
Assume
a transmission
efficiency
of 0.75 and at
top
gear
the
vehicle is
expected to
climb a
gradient
of
1
in 40.
(b)
\r
.:
1
t-.
2
J
8068
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7/25/2019 AT 2352 Chassis components design University QP
13/14
13.
(a)
A
vehicle
having
an
overall
length
of
360
cm
is having
a wheel
base
of
180
cm
and
the
overhang
at
front and
""*
are equar.
The following
is the
loading
pattern
of
the
side
member
of the frame.
(i)
A2lA kgf
aeting
at
4b
cm
in
front
of
front
axle.
(ii)
A
180
kgf
acting
at 45
cm
behind
the
front
ude.
(iii)
A
180
kgf
acting at
45 cm
in front
of
rear
a:rle.
(iv)
67.5
kgf
acting
at
45 cm
behind
the
rear
a:de.
(v)
A uniformly
distributed
load
of
1.?5
kgflcm
run
over
the
entire
length
of
the
frame.
14'
(a)
Aggrrrning
a dynamic
stress
equal
to
twice
the
static
stress
and
the
allowable
bending
stress is
O00kgflcm2.
Find
out
the
rnaximum
bending
moment
and
section
modulus
for
the
channel
section.
Or
A
semi
elliptic
leaf
spring
of a vehicle
has
its leaves
?Emm
wide
and
10mm
thick
and
its effective
length
is
g00mm.If
the
stress is
not
to
exceed
220725
k
Pa when
the
spring
is
loaded
to
4g0b
N, find
out the
number
of leaves
required
and
the
deflection
under
this
condition.
If
the
spring
is
just
flat
uhder
the
load
what
is
its initial
radius
of
curvature.
TakeE=196.2x106kPa.
T'he
load
distribution
between the
front
and the
rear a:
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7/25/2019 AT 2352 Chassis components design University QP
14/14
1\J
\1.
v.
1*,-l
\/
g'
}\
\,
.{
i
7
(b)
sketeh
a
seni'Iloating
t5rpe
rear axle
coastrrrction
and name
its
co_mponents.
Further
uJ
o"f
tu"
loads
and
stres";;thg
";
th;."-ty;
of
axleg.
Design
a
fult
lloating
rear
axle
from
the
foilowing
data :
Ivlaoirnrrrn
engine
torque
=196
N-m
Gear
ratios
=
4:1,
2.6:1,1.4:1
&
L:l
.:
the
diameter
of
the
ulun
"fo".ic
to
be founj
out.
4
J
8068