Transcript Formula SAE - Pittsburg State University

Formula SAE
04/27/2007
AET
Team Members
Andrew Tyler
Shawn Albertson
Paul Vandevender
Adam Pompa
Matt Davied
Jake Speilbusch
Introduction
PSU Racing is embarking on its inaugural
FSAE competition. Our team of six
members was formed August 2006 and
has been diligently working to meet the
goals set forth by the FSAE Rules
committee to compete in the west
competition June 2007.
Objective
The objective for the 2007 PSU racing
team is to complete the build of the vehicle
and finish all dynamic events at the west
competition as well as laying a foundation
to ensure success and continual
improvement by the team at future events.
Manufacturability
• Our vehicle design utilizes commercially
available products except for the frame,
uprights, fuel tank and drivers control
components. This ensures replacement
parts availability if needed, as well as
properly engineered parts for the
application.
Reliability
• Designing our vehicle to use commercially
available products minimizes design risk
by utilizing proven designs to meet the
criteria of the event. Our fuel injection
system, E.C.U. and drive-train were all
assembled from commercially available
components designed to meet our
application.
Cost Efffectiveness
• As stated above, we are a first year team
and have an initial budget of $15,000. We
have chosen designs that meet the criteria
set forth by the rules committee and
satisfy our goal of producing a low-cost
vehicle. This approach will also help us to
meet the goal of building a vehicle under
$15,000.
Conceptual Designs
The first conceptual design utilized side
pods housing two radiators and electronic
equipment. The second conceptual
design utilized a single rear mounted
radiator with no side pods. After carefully
analyzing cost and manufacturing time
projections, the second conceptual design
was chosen to be produced.
Two Basic Body Designs
• Side Louver Design
– Consists of bullet type car but with side
louvers.
– Space for radiator and electronics.
– Added Weight
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Two Basic Body Designs
• Bullet design
– Consists of a straight through body with no
wings or side louvers.
– Streamline design.
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Frame
• The vehicle utilizes a tubular space frame that is composed of T.I.G.
(Tungsten Inert Gas) welded 4130 chrome-moly steel tubing.
• The cockpit was designed to give the driver room for entering and
exiting the car, as well as provide room for steering and shifting
motion of various sized drivers.
• The front portion of the frame provides ample room for drivers with
different leg lengths.
• The rear portion of the frame was designed using the engine as a
rigid component.
• A-arm and suspension mounting points of the frame were analyzed
using Pro-Mechanica and designed to have a safety factor of 3.
• Throughout the frame, the members have been triangulated to
increase rigidity and reliability.
Impact Attenuator
• The guidelines set forth by the SAE were met by utilizing
proprietary soy-based foam from Pittsburg State
University’s organic polymer research center.
• The foam, through finite element analysis as well as
destructive testing, showed an average deceleration of
9.17g. Substantially lower than the 20g maximum.
• The foam was chosen because of superior performance
to other materials as well as cost. The foam material
used in the attenuator was purchased for $3.24, a cost
that is well below other material with similar properties.
Upright Assembly
• Both the front and rear uprights are green sand castings
of 356 aluminum alloy with a T6 heat treatment.
• The uprights were analyzed using Pro-Mechanica and
designed to have a safety factor of 3.
• Using pre-manufactured hubs and bearings from
commercially available vehicles allows the owner to
purchase replacement parts from various suppliers.
• Each upright assembly includes the same hub and
bearings, this simplifies the manufacturing process.
Suspension
• The suspension utilizes double a-arms in both the front
and rear.
• The a-arms are comprised of ¾” 4130 chrome-moly steel
alloy round tubing. The material allows our safety factor
of 3 to be met.
• A single vertical coil-over shock with push rod activation
is used on each corner of the vehicle for the dampening
system.
• The a-arms attach to the uprights and frame using 3/8”
I.D. heim joints. The heim joints are installed in double
shear to ensure a safety factor of 3.
Engine and Transmission
• 600 cc Honda Sport Bike Engine
– Fuel Injected
• 6 speed Honda Transmission
– Linked to mechanical ratchet shifter
Engine Control Unit
• An engine control unit (ecu) manufactured by
Dynojet research is used to control the fuel
injection system.
• This system uses the stock ecu in conjunction
with the unit from Dynojet.
• This allows use of the factory spark curve and
only change the fuel map which is most effected
by the restricted intake.
• The unit costs substantially less than a stand
alone ecu.
Restrictive Intake
• An intake was manufactured using widely
available polyvinylchloride (pvc) piping.
• The 20mm restrictor was manufactured out of
aluminum billet.
• The intake system uses 2” pvc to connect the
restrictor to the factory air box which contains
one set of the factory injectors.
Drive-Train
• A Torsen differential was selected and modified to
accept a 38 tooth 525 sprocket input.
• This unit will provide traction to each rear wheel
proportionally, but allow one side to free wheel during
turns to prevent wheel hop.
• Power is transmitted from the differential via splined
constant velocity shafts which are then splined to
commonly available wheel hubs.
• The constant velocity shafts used are from a
commercially available vehicle and cost effective to
purchase rather than manufacture.
Ergonomics
• Drivers comfort was a major concern during design.
• This matter was addressed by utilizing a movable pedal
assembly to ensure drivability by drivers with crotch
height of anywhere from 30” to 36”. This range was
chosen to accommodate male drivers who fall between
the 5th and 95th percentile according to the Design
Criteria for Military Systems, Equipment and Facilities.
This range also accommodates female drivers within the
50th-99th percentile.
Competition
• Static Events
– Cost and Manufacturing Analysis
– Presentation
– Design
Competition
• Dynamic Events
– Acceleration
– Skid Pad
– Autocross
– Fuel Economy
– Endurance
Customer Requirements
• Minimum 60 inch wheel base
• Must have 4 wheels that are not in a
straight line.
• Wheels must be a least 8 inches in
diameter.
• Must have dry (slick) and wet (treaded)
tires to compete.
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Customer Requirements
• Steering must affect at least two wheels.
• Brakes must act on all four wheels from a
single control.
• Must be equipped with 5 point safety
harness.
• Engine is restricted to 610cc or less.
• Air intake restricted to 20 mm.
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Frame
PRV
Analysis
• Static loading using Pro-Mechanica
• Loads– 650 lbs
• Car and Driver
– 2 G’s Lateral
– 2 G’s Braking
– 3 G’s Vertical
PRV
Analysis
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PRV
PRV
SAA
Ex. Working Drawing
SAA
Routing Sheet
COMPANY NAME:
Date:
Oper. #
5
PSU Racing
Part Name:
11/17/2006
Rear Passenger Hub
Size of Run: 1 Unit
Description
Rapid Prototype
Create RPT part
OperationMaterial
RPT
Time
Feed/ Speeds
Poly
24hr
NA
10
Create Flask
Ram
Ram part inflask
green sand
Add gating system
Remove patterns
Place on pouring line
Green Sand
.5hr
NA
15
Pour Part
Pour 356 Al Alloy
in flask
Allow to cool
Break out part
Casting
356 Al Alloy
2hr
NA
20
Solution Treatment
Heat treat part in
furnace
Quench
Age part in furnace
Heat treat
356 Al Alloy
24hr
NA
25
Machine Holes
Machine bearing
surface
Machine ball joint
clearance
Mill
356 Al Alloy
1hr
?
MD/AT
Final Assembly
SAA
SAA
MD
Conclusions
• In conclusion, our vehicle design is simple yet effective.
Through F.E.A, destructive testing, and research it is
determined this design meets or exceeds all criteria set
forth by the S.A.E. and PSU Racing. The goals of
manufacturing a product that is easy to manufacture,
reliable, and cost effective were met. By meeting the
goals set forth, a vehicle that is marketable to the
average weekend racer was produced. We appreciate
the time taken by the advisory committee to review this
report.
Questions?