chassis frame

chassis frame

1. Chassis Frame 1

2. Chassis
Frame
Body
Chassis Frame 2

3. The Functions of the Chassis frame
1.To carryall the stationary loads attached to it and loads of passenger and cargo
carried in it .
2.To withstand torsional vibration caused by the movement of the vehicle
3.To withstand the centrifugal force caused by cornering of the vehicle
4.To control the vibration caused by the running of the vehicle
5.To withstand bending stresses due to rise and fall of the front and rear axles.
Various loads acting on the Chassis frame
1.Stationary loads namely the loads of permanent attachment like all the parts of the
chassis, body etc.
2.Short duration loads while turning , braking etc.
3.Momentary loads while quick acceleration , sudden braking etc.
4.Loads applied while crossing roads of irregular and uneven surfaces
5.Loads caused by sudden accidents, head on collusions etc.
6.Loads caused by irregular and overloading of vehicle.
Chassis Frame 3

4. Ladder frames
•Itconsistsoftwosymmetricalbeams,rails,orchannels
runningthelengthofthevehicle,andseveraltransverse
cross-membersconnectingthem.
•Usedbyearlymotorcars•Earlycar’sbodyframedidnot
contributemuchforvehiclestructure.Itisnowseenmainly
ontrucks.
•Carriedallload(bendingandtorsion)
Advantages:–
•Thisladderframeresiststwistingbetterthanaunibody
vehicle,soit’sgenerallypreferredfortowingorcarrying
heavyloadsandforaggressiveoff-roaddriving.
•It’salsoeasiertomodifythesevehicles’suspensionsto
makeroomforadditionalwheeltravelorlargertiresand
wheels.
•Usedinflatplatforms,boxvans,tankersanddetachable
containers
•Stillusedinlightcommercialvehicleslikepickup.
Chassis Frame 4

5. Integrated Frame and Body (Monocoque)
•Theintegratedframeandbodytypeof
construction,alsoreferredtoasunitized
construction,combinestheframeand
bodyintoasingle,one-piecestructure.
•Thisisdonebyweldingthecomponents
together,byformingorcastingtheentire
structureasonepiece,orbycombining
thesetechniques.
•Inatrulyintegratedstructure,theentire
frame-bodyunitistreatedasaload-
carryingmemberthatreactstoallloads
experiencedbythevehicle-roadloadsas
wellascargoloads.
•Today99%carproducedinthisplanet
aremadeofsteelMonocoquechassis.
Chassis Frame 5

6. •Itdoesn’trelyonheavysteelrailslikethoseofa
body-on-framevehicle,unibodyconstructioncuts
significantweightoutofthevehicle,allowingfor
betterfueleconomy.
•Italsooffersbetterhandlingandridecomfortandis
safer,sincetheentirebodycanabsorbtheenergy
forcesinacrash.
•Cheapformassproduction.
Disadvantage:
• Impossible for small volume production
Spot-winding:
•Twoplatesareconnectedby
resistancetoelectriccurrentflow&
workpieceareheldtogetherunder
pressureexertedbyelectrodes.
•Thespotweldedtogetherbyrobot
arminstreamproductionline.
Chassis Frame 6

7. Semi Integral Frame:
• In this type of frame load is transferred to the body
structure also.
• This Frame however is heavy.
• In semi integral frame half frame is fixed in the front end
on which engine gear box and front suspension is
mounted.
• This type of frame is used in some of the European &
americancars.
Chassis Frame 7

8. Tubular space frame:
•Itis3-dimensionaldesign
•Tubularspaceframechassisemploysdozensof
circularsectiontube,positionsindifferent
directionstoprovidemechanicalstrengthagainst
forcefromanywhere.
•Thesetubesarewelded&formsaverycomplex
structure.
•Forhigherstrengthrequiredbysportscars,
tubularspaceframechassisusuallyincorporatea
strongstructureunderbothdoors.
Advantage:•Verystronginanydirection
(comparedwithladderchassisandMonocoque
chassisofthesameweight)
Disadvantage:•Verycomplex,costlyandtime
consumingtobebuilt.•Itengagesalotofspaces
risethedoorsealandresultindifficulttoaccessto
thecabin.•Impossibleforrobotizedproduction.
Chassis Frame 8

9. Backbone chassis frame:
•Itconsistsofastrongtubularbackbone
(usuallybutnotalwaysrectangularincross
section)thatconnectsthefrontandrear
suspensionattachmentareas.Thetunnelor
backbonebecomesaprimaryloadbearing
member.
•Providesnearlyallthemechanicalstrength.
•Itisalmostatrademarkdesignfeatureof
CzechoslovakTatraheavytrucks(cross-
country,militaryetc.)
Chassis Frame 9

10. Framearemadeoffollowingsections:
Channelsections
•Boxsections
•Tubularsections
*Channelsectiongoodinbending,tubularintorsion&boxinbending
&tortion
Chassis Frame 10

11. Chassis Frame 11