forklift fundamental

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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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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


- 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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OVER ALL WIDTH no. 16

Width between end of both sidesas Drive axle, Tires, Fenders, Forks, Carriages


- 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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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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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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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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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

forklift fundamental

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