forklift fundamental
TRANSCRIPT
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Forklift Fundamental
February 2008
Overseas Sales & Marketing
Forklifts Business Group
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CONTENTS
What are forklifts
Terminology
Load Capacity
Mast Types
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What are Forklifts
Classification by Industrial Truck Association (ITA, USA)
Class 1 : Counter-balancedElectric Riding type Forklift
Class 2 : Riding type Electric
Warehouse Equipment
Class 3 : Pedestrian type Electric
Warehouse Equipment
Class 4 : Counter-balanced Internal-combustion
Cushion Tire type Forklift
Class 5 : Counter-balanced Internal-combustion
Pneumatic Tire type Forklift
Class 6 : Tractors
Class 7 : Rough Terrain Forklift
Class 8 : Manual and Semi-powered Pallet truck
Conventional Forklifts
- Class 1 : C/B Electric
- Class 4 : C/B I.C. Cushion type
- Class 5 : C/B I.C. Pneumatic type
Warehouse Equipment
- Class 2 : WH - Riding type
- Class 3 : WH - Pedestrian type
Class 1 - 5 are regarded as forklifts
and others ( 6 8) are not.
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What are Forklifts
C/B Forklifts and Reach Truck Doosan Range
Classification by number of Wheels
3-wheels ... Surffix T
4-wheels ... Surffix S or X
Classification by fuel type
Diesel ... Prefix D
LPG ... Prefix G or GC
Gasoline ... Prefix G or GC
Classification by riding type
Sitting type Suffix J or JW
Standing type Suffix S
Class 1
C/B Electric
: Prefix B
Class 4
C/B I.C.Cushion type
: Prefix GC
Class 5
C/B I.C.
Pneumatic ty
pe
: Prefix D or G
Class 2
WH, Riding type
: Prefix BR
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What are Forklifts
Warehouse Equipments (WH)
Class 2
WH
Riding type
Class 3
WH
Pedestrian type
Ride Pallet Reach Truck High Level
Truck High Lift Stacker Order Picker
Power Pallet Truck Low Lift Warkie High Lift Stacker Pedestrian
Low Lift Pallet Truck Horizontal Pedestrian High Level
Order Picker Stacker Order Picker
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Overhead guard
MAST
Carriage
Counter-weight
Forks
Load
Backrest
Front Working Lights
Seat with Hip Restraint
Tilt Cylinders
Steer / Rear Tires
Drive / Front
Tires
Front Combination Lights
Major Components
What are Forklifts
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Rear Combination Lights
StrobeLight
Back-Up Alarm
Rear Working Light
Steering Wheel& Knob
Control Levers
Parking
Brake
What are Forklifts
Major Components
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CONTENTS
What are forklifts
Terminology
Load Capacity
Mast Types
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Terminology Dimensions of Mast
MFH : Maximum Fork Height no. 9
Height from ground to upper face of forks,
at upright / vertical position of mast
with rated load weight
It is the required height for stored height of load.
OAL : Over All Height no. 17 & 19
(Mast Fully Lowered Height)
Height from ground to upper end of mastat fully lowered fork position
at upright / vertical position of mast
If overhead guard is higher than this, OAL is
height to the upper end of overhead guard
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Terminology - Dimensions of Mast
FFH : Full Free Lift Height no. 10
Height from ground to to upper face of forkswithout extending the mast (or, height to the position
of forks without change of masts OAL), without load
In case of FF and FFT mast, FFH is different for
cases of with Load backrest and without,
due to the height of Load backrest.
It is useful for operation with low ceiling building,
container or entrance door.
Maximum Mast Extended Height no. 18
Over all height from ground to height upper end of
equipment (carriage, load backrest or forks)when fork is fully lifted or when mast is fully
extended, at upright / vertical position of mast
This height is different for cases of with Load
backrest and without, due to the height of Load
backrest.
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Terminology - Dimensions of Mast
TILT ANGLE no. 14
a) FORWARD TILT ANGLEAngle degree of tilting the mast to maximum
forward position, from vertical position of mast.
b) BACKWARD TILT ANGLE
Angle degree of tilting the mast to maximum
backward position, from vertical position of mast
As this angle is critical for trucks stability and rated lifting capacity at high fork position,
the degree could be reduced.
LOAD MOMENT CONSTANT no. 22
Distance between center of front tires and forks faceat vertical position of mast
It is making influence to trucks length and
trucks rated capacity.
Forward
Tilt Angle
Backward
Tilt Angle
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Terminology - Dimensions of Vehicle
OVER ALL LENGTH
Length between rear-end and front-end of forks
Points to be considered :
- Minimum turning radius
- Minimum intersection (90 degrees) aisle width
LENGTH TO FORK FACE no. 15
Length between rear-end of vehicle and forks face
WHEEL BASE no. 38
Distance between center of front wheel and
center of rear wheel
While wheel base is increasing, vehicles front-read
stability and rated capacity are getting better,
but, working condition is getting worse due to
bigger turning radius.
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Terminology - Dimensions of Vehicle
TURNING RADIUS no. 21
Minimum radius of trucks outside trace of turning
at minimum travel speed ,by maximum steering angle,
with un-load
AISLE 90 DEGREE STACKING no. 23(= RIGHT ANGLE STACKING AISLE)
Minimum aisle width for forklifts turning
by 90 degrees angle for staking load
Points to be considered :
- Aisle width between shelves at both sides
Caution : It is variable depending on size of load
Calculation of real Aisle Width
: Turning Radius (Minimum) + LMC (Load Moment
Constant) + Length of Load / Forks + Clearance
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Terminology - Dimensions of Vehicle
OVER ALL WIDTH no. 16
Width between end of both sidesas Drive axle, Tires, Fenders, Forks, Carriages
Points to be considered :
- Width of entrance, aisle and load
- Turning radius of forklift
WHEEL TREAD
Width between centers of left and right wheels
While wheel tread is increasing, vehicles left-right
stability and rated capacity are getting betterbut, working condition is getting worse due to
bigger turning radius and in narrow aisle.
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Terminology - Dimensions of Vehicle
GROUND UNDERCLEARANCE
The height from ground to lowest position of vehicle,such as lowest end of outer mast, drive axle
housing or frame
Considering point
: rough surface and obstacles on ground
TOTAL SERVICE WEIGHT (UN-LOADED) no. 32
Total weight of vehicle without load and operator
Considering point: Transportation and lifting the truck for moving
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Terminology - Performance
GRADEABILITY no. 30
Tangent percent (tan %) of a slope which forklifts ability to ascend with rated load
The gradeability varies by surface condition.
If the surface is clear or wet, it would be reduced.
So, actual gradeability would be different from the
data on specification sheet.
Measuring unit of it is different from manufacturer
to manufacturer.Formula of Gradeability
= Height of Slope (H) / Length of Slope (L) X 100%
DRAWBAR PULL no. 28
Towing force exerted in the direction of motion of
forklift trucks coupling pointThe maximum force is determined upon the
friction
between the drive wheels and the supporting
surface when the load is being moved at a rate
of
1 MPH.
This data is extremely important because the bigger\the drawbar pull, the stronger the truck is.
H
L
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Terminology - Performance
TRAVEL SPEED no. 24
Trucks maximum driving speed with loaded orunload when the accelerator pedal is to the floor
and the engine is at wide open throttle and
maximum RPM.
LIFTING AND LOWERING SPEED no. 25 & 26
Mast and/or forks speed of lifting and lowering
speed with load or unload
The lowering speed is limited and controlled by
a valve to prevent both vehicle instability and
damage to the load which can result from sudden
drops caused by the weight of the load.
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Terminology - Performance
LOAD CENTER no. 4
Distance from fork face to center of load
If a load has for example a length of 1 meter,
its load center is at 500 mm
Load center by lifting capacity :
- 1.0 to 3.0 ton: 500mm as base
- 3.5 to 5.0 ton: 600mm as base and 500mm as option- 5.5 and over : 600mm as base
CENTER OF GRAVITY (C.G.)
Each solid body has a certain weight and a Center ofGravity which is assumed to be located in the exact
center i.e. at the equidistant center of all its sides.
(in the case of a regularly shaped body.)
Load
Center
(L/C)
Load Moment
Constant (LMC)
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Terminology - Performance
RATED LOAD CAPACITY no. 3
Maximum lifting weight of load at load centerat vertical position of mast
As there are various factors influencing to the
capacity, those factors have to be reviewed
to determine actual capacity.
The load capacity of a forklift truck varies dependingon the horizontal distance between the vertical
surface of the forks and the center of gravity of the
load.
LOAD CAPACITY CHART
A forklift truck equipped with a load chart indicates
this relationship between the distance and the load
capacity. The X-axis shown on the load chart is
called the load center and the Y-axis is the
maximum load capacity.
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CONTENTS
What are forklifts
Terminology
Load Capacity
Mast Types
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And that its position varies based on the load position
If the load position changes, the location of the
C.G. also does, accordingly
We may reasonably estimate that the center of gravity
of the load agrees with its physical center, when theload has a uniform form
CENTER OF GRAVITY (C.G.)
Imbalance happens and then, upset
if the weight of one of its sides
is increased or separatedSuch accident is more likely on unven grounds or ramps
and when the mast is fully extended and inclinedbackwards with heavy loads.
Load Capacity
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The lift truck without loadis a mass that has its
own center of gravity
Load Capacity
What happens when lifting a load ?
When a forklift takes
a load, the centers of
gravity moves to the
wheel and the load
are combined
forming a resulting
center of gravity
When the load rises the resultingcenter of gravity movers upwards
following an intermediate vertical
line between the centers of gravity
of the lift truck and the load
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Load Capacity
What happens when the mast tilts forwards ?
.... The resulting
center of gravity
moves up
The weight of the load, and the
elasticity of the mast makes the
situation still even more critical
Whenever one inclines the loadedmast towards ahead, it is
necessary to be an extreme carefulThe truck looses
its balance !
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Once again, materials handl ing equipm ent is sure and stable.
However, any manoeuvre with lo ad and especial ly when the mast is extended requires
som e precaut ions. And of cou rse, any bruta l manoeuvre shoud be avoided.
Load Capacity
What if the loaded mast is tilted backwards
while highly extended ?
Here again, we risk upset !
Forkflifts lean on 4 points, 4-wheels
in terms of lateral (right-left)
stability, the forklifts leans on
this triangle of stability
But, as the back axis has a swing
capacity so that the 4 wheels lean on
the ground on unequal lands
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Once again, when a forklift takes
a load, the resulting center ofgravity moves ahead
...and that the resulting center of
gravity also moves according tothe tilt of the mast
Load Capacity
And, for the same reason,
when the mast tiltsbackwards..
The resulting
center of gravity
moves backwards
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The lif t ing (load) capacity is always specif iedwi th load center
Such a long load shou ld be l ight in
order to be handled s afely
Here the capaci ty is even more
reduced du e to a very long load
length
With su ch a distant load center, the
l i f t ing capaci ty is cons iderably
reduced !
Load Capacity
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Each s pecif icat ion sh eet includ es a curv e which i l lustrates theinf luence of the load center on the load capacity
Load Capacity
Model : D30S-5, G30E-5, G30P-5Mast A : MFH 2030 4350
Mast B : MFH 4960This truck has a nominal capacity
of 3000 kg center at 500 mm.If the center of the load were
located to 700 mm, the capacity
would be approximately 2500 kg.If the center of the load were
located to 900 mm the capacity
would be of about 2200 kg.
And with the load center at
1200 mm the capacity would bereduced to less than 1800 kg.
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Load Capacity
MAST CAPACITY CALCULCATION by Load CenterP : Basic (Nominal) rated capacity of Mast (KG)LMC: Distance from drive wheel center to
fork shank front face (mm)
LC : Truck rated load center (mm)
W : Allowable capacity in special customer's
load center (kg)
LC : Special L.C of customer (mm)
T : Fork Thickness (mm)
Capacity conversion from truck rated L.C. to
customer's special L.C.
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To calculate the capacity of a forkliftif the center of gravity of the load
located at 500 mm
Mathematical calculation of the lifting capacity
Basic (Nominal) Capacity .... = 2000 kg
Distance to the load gravity center
------------------------------. = 500 mm
Load Moment Constant (LMC) = 445 mm
(Distance from drive wheel axis
to the forks front face)
Load Capacity
First, we will determine the nominal capacity of forklift through following calculation :
Front moment of the forklift : 2000 x (500 + 445) = 1.890.000 kg/mmDistance from the front axis to frontal face of the forks ......... 445 mmCenter of gravity of the load .............................................. 700 mm
1.890.000
445 + 700= 1,650.6 kg at 700mm L.C.
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Load Capacity
ATTACHMENT INSTALLED CAPACITY CALCULATION
Wa : Attachment Weight (kg)LL : Attachment Load Lost
(Attachment thickness - mm)
CG : Attachment Center of Gravity (mm)
LCa : Rated Load Center of Attachment (mm)
Pa : Maximum Allowable Capacity of
Attachment at Rated Load Center (kg)
A : Longitudinal Length of Unit Load (mm)
W : Unit Load Weight (kg)LMC: Distance from drive wheel center
to fork shank front face (mm)
LC : Truck rated Load Center (mm)
T : Fork Thickness (mm)
P : Basic (Nominal) rated capacity of Mast
(Attachment uninstalled capacity-kg)
Pc : Attachment installed capacity (kg)
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Load Capacity
1) Select proper Attachment (Confirm related data from catalog etc)
a) Check rated Load Center of Attachment and customer's actual working Load Center.
If same, following calculation is unnecessary. Only need to compare rated capacity of
Attachment and customer's working Load.
b) If working L.C is longer than rated L.C of Attachment, make sure whether Attachment
Capacity is larger by following formula.
2) Calculate capacity when attachment is installed
3) Compare Pc and W value. When Pc is larger than W, considered Truck and Mast will be
possible. If smaller, select more large capacity truck and recalculate.
4) If working Load Center (working load x 0.5) is smaller than truck rated L.C,
working load center shall be considered with truck rated Load Center.
ATTACHMENT INSTALLED CAPACITY CALCULATION
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Load Capacity
USING LOAD CAPACITY TABLE (Excel File)
Doosan is offering Rated Load Capacity Table by Excel File.
1) In order to find the capacity, following points have to be known.
- Truck Model - Attachment
- Mast - Tilt Angle of Mast
- Tire - Load Center required
2) Choose Type of Attachment - supplied from Doosana) Models with capacity
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Load Capacity
USING LOAD CAPACITY TABLE (Excel File)
Capacity at Load Center 900mm of :D25S-5 + Integrated Sideshifter + FFT 4730 mast + Tilt angle 6-8 degrees ?
1. Open excel file of
the Model and
Choose Sheet of
Attachment
2. Find Mast, Tilt angle,
Tire andLoad Center
3. You can not miss
the Capacity
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CONTENTS
What are forklifts
Terminology
Load Capacity
Mast Types
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MAST types
Standard Mast (STD)
2-stage Low Free Lift Mast
Duplex Mast
- Total visibility
- Limited Free Lift
(+/- 150mm).
- It cannot work in areas wit
h low height of warehouse
or entrance.
Full Free Lift Mast (FFL)
2-stage Full Free Lift Mast
Duplex Mast
- Forks free left without
moving mast.
- Suitable for waoring in a
container of low warehouse
of entrance.
Full Free Triple Mast (FFT)
3-stage Full Free Lift Mast
Triplex Mast
- Forks free left without
moving mast.
- Application for high lifting
height is necessary as well
as for low height area
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MAST types
Standard Mast (STD) : 2-stage Mast / Duplex Mast
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MAST types
Full Free Lift Mast (FFL) : 2-stage Full Free Lift Mast
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MAST types
Full Free Triple Mast (FFT) : 3-stage Full Free Lift Mast / Triplex Mast
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MAST types
Quadruple Mast : Quad Mast / 4-Stage Mast
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MAST types
How to choose a Mast
OAL
Height of Entrance Door
Clearance has to be more than 100 mm.
a) Check the entrance Door and choose OAL of mast
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MAST types
How to choose a Mast
b) Check MFH of mast and height of load and height to warehouse
Max. Stacking
Height
& over
Height
of Load
Height of Warehouse
& over & over
Height
of Load
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THANK YOU