190102 A Flashcards
List the 3 functions of a vehicle frame.
- Support the load the vehicle is carrying
- Resist shock and torsional loads while vehicle in operation
- provide a platform where motor components are attached
Define maximum bending moment
The pont at whiuch the aximium force is concentarted on a frame
Which 2 components make up a ladder type frame?
- Parallel frame rails
- Cross members
What is the function of the frame crossmembers?
to reinforce the frame assembly
Which one of the following is not a common frame rail shape?
a) trapezoid
b) channel
c) box
d) I-beam
Trapezoid
What is the surface between the flanges of an I-beam frame rail called?
Web
What is the function of a gusset that is attached to a frame crossmember?
Provide resistance to frame weaving
The _________ and _________of frame components affect the strength of the frame.
size and strength
Define the term yield strength as it applies to the strength of frame materials.
Refers to the amount of stress that the material can withstand without becoming deformed
Which of the following frame materials would have the highest yield strength?
a) mild steel
b) high strength, low alloy steel
c) heat-treated alloy steel
d) copper-aluminum alloy
c) heat-treated alloy steel
The term section modulus refers to the strength of frame components based on which 4 aspects?
1) height
2) Width
3) thickness
4) Shape
A frame with a high resisting bending moment (RBM) has _____________ than a frame with a low RBM.
less strength
List four (4) functions of a vehicle suspension system.
1) Secure the axles to the frame while maintaining proper alignment.
2) Support the weight of the vehicle and its cargo while maintaining lateral stability.
3) Cushion shock loads.
4) Allow axle movement so that the tires follow the contour of the road.
The combined weight of the components below the connection point is called ______________ because ____________
unsprung weight because it is located below the suspension system
The suspension system must hold the axles in alignment with the frame. This means the wheels are held ____________________
wheels are held parallel to the frame rails
What are the 3 most common types of energy-absorbing devices used in suspension
systems?
- leaf spring
- rubber cushion
- rubber air spring
The energy-absorbing device of a suspension system is released when _________________
it rebounds.
Solid-mount suspension systems are best suited to applications that ________________
operate on rugged terrain.
Equalizer beams reduce the effect of shock loads to the vehicle frame by ____%
50%
Axles are stabilized against braking and acceleration forces by _____________________
longitudinal torque
rods
What is the function of transverse torque rods?
The function of transverse torque rods is to provide improved side-to-side stability by distributing side loads more evenly across the entire length of the axle.
Progressive leaf springs provide a low spring rate when the vehicle is _______________ and a high spring rate _____________
Progressive leaf springs provide a low spring rate when the vehicle is unloaded and a high spring rate under load.
Auxiliary springs help to support the vehicle when it is ________________
loaded
_______________ accommodate changes in spring length as the suspension jounces and
rebounds.
Spring shackles
What is the main function of a shock absorber?
The main function of a shock absorber is to dampen spring oscillation.
What is the function of vertical drive pins on a rubber cushion type suspension?
The function of vertical drive pins on a rubber cushion type suspension is to allow the saddles to move up and down as the load cushions deflect, thus maintaining
alignment of the saddles with the frame rails.
An advantage that air spring suspensions have over other suspension types is that they provide superior
________________
ride quality
What is the function of the pressure protection valve in an air spring suspension?
ensures that a minimum safe pressure is maintained in the air reservoir for air brake operation if a leak occurs in the suspension air system
When does the ride height control valve supply air to the air springs?
when additional load is added to the vehicle.
What is the function of the two-way control valve and dump valves?
The function of the two-way control valve and dump valves is to allow the driver to exhaust the air springs so that the suspension will lower when connecting or disconnecting a trailer.
