Sophisticated Design

Automatic Tailgate

Final PresentationDecember 5, 2001

Ted Akiskalos

June Doan

Tarek Elshazly

Maggie Kim

David Nimitz

Sharon Ramey

Objective

To build an automatic system that will facilitate the operation of a truck tailgate

Goals and Constraints

To develop an automatic truck tailgate that is:

• Cheap• Robust • Compact• Reliable• Not a major interference to truck load• Easy to use

Overall Design

Agenda

• Part Drawings- Locking Mechanism- System Cover- Bracket

• Engineering Analysis

•Prototype Presentation

Locking Mechanism

Parts (con’t.)System Cover

Parts (con’t.)

Bracket

Front View Back View

Parts Detaching Pin

Cable Detachable Cable Secure

0.5”

1.5”

0.4”

1.5”

0.6”

2”6”

1/14”

Front View

Side View

2”

6”

Spool

2”

Cable

Eyelet

Engineering Analysis

lbW

inWinlb

LWLF

M

T

O

903

171730

3

0

To find weight of tailgate:FT

W

Fx

Fy

L

FT = Force required to lift the tailgate from the edge (30lb)W = Weight of the tailgateFx & Fy are the reaction forces in the X and Y axis, respectivelyL= Length from hinge to end of tailgate

L/3

o

L

Engineering Analysis (con’t.)

lblbTF

F

inlbinT

LWlT

M

x

x

O

lbT

88.3145cos08.45cos

0

3

17901645sin

3sin

0

08.45

To find tension in cable:

To find added force in x direction:

W

Fy

L/3

T

45o1”

Fx

W = Weight of the tailgate (90lb)Fx & Fy are the reaction forces in the X and Y axis, respectivelyT = Tension in the cableL= Length from hinge to end of tailgatel= Length from hinge to attachment point of cable

ol

Measuring the Tension in the Cable

Engineering Analysis (con’t.)

Motor requirements

ininld 13.251624

12

4

1

Distance connection point on tailgate travels:

inlblbdTW .98.1132"13.2508.45*

Work required:

hpWs

inlb

s

inlb

dt

dWP 017.08.12

.3.113

10

.98.1132

Power required:

inlbininlbrTTorque .08.451.08.45*

Torque needed: T

r

Spool

Motor

16”

20”

x

Open tailgate

Closed tailgateD=3/8”

17”

4”

Engineering Analysis (con’t.)Hole extension

20”

16”

x

4”

90-

Triangle created in open position:

To solve for hole extension, x:

34.51

16/20tan

"2.3"4/)34.5190tan(

xx

Hole Extension

Fabricating Spool

Motor and Drive Mechanism Mounted on Truck

Installing a Support Bracket for Spool

Preliminary Cable, Pin Assembly

Completed Cable, Pin Assembly

Fitting the Cover to the Side of the Bed using a

Template

Securing the Cover

A Pin used to Keep the Spring in Place

Lower Limit Switch

Mounting Switch under a latch

Wiring a circuit

DifferencesDesign•Operate from cab with handle

•L-bracket to mount motor only

•Cover for motor only

•Larger spool

•Use existing latch

•Gravity only force

•Circuit

•Raised by slight angle

•Momentary push button

•Four pole/double throw relays

•Rod holding limit switch

•Possible to have tailgate half open

Prototype•Operate from existing tailgate latch

•L-bracket and two straight brackets to mount motor and align spool

•Cover for motor and circuit; brackets added

•Smaller spool

•Removed springs from latch

•Spring Force

•Circuit

•Manual activation

•Push and hold button

•Single pole/double throw relays

•Rubber clasp, extension holding switch

•Safety feature added to prevent this