JAYALAKSHMI INSTITUTE OF TECHNOLOGY

THOPPUR, DHARMAPURI

AUTOMATIC COCONUT DEHUSKING MACHINE

USING MECHATRONICS PRINCIPLES

Presented by

K.NANDHAKUMAR

J.JOVIN JAMES

nandhakarthik92@gmail.com

ABSTRACT

The outer shell (husk) of the coconut is removed for various purposes like extraction of

oil, coir products, preparation of food items, etc. Until now the shell of the coconut is

removed manually. The manual dehusking involves risk due to injury and consumes

more time to dehusk (peel) the coconut shell and labor fatigue. This leads to less

productivity and more labor cost. To overcome this, there is a need to automate the

dehusking process.

The invention of the project is that, the removal of the husk of coconuts by low cost

automation. This project technique consists of pair of curved shells, multi hooks and two

double acting pneumatic cylinders to remove the husk of the coconut, and one single

acting pneumatic cylinder to hold and press the coconut. Here 5/2 spring return single

solenoid direction control valve is used to actuate the two pistons which are used to

remove the husk and 2/2 single solenoid direction valve is used to actuate the holding

cylinder which press and hold the coconut in the shell.

The range of operating pressure is 12 to 16 bars. The project is an attempt to replace man

power required to dehusk (peel) the outer shell of the coconut.

All the analysis and conclusions in this paper are strictly based on the project

“AUTOMATIC COCONUT DEHUSKING MACHINE”, done at our college.

INTRODUCTION

The outer shell (husk) of the coconut is removed for various purposes like

extraction of oil, coir products, preparation of food items, etc. The outer shell is now

being removed manually. Manual dehusking involves risk and consumes more time. This

leads to less productivity and more labor cost. To overcome this, there is a need to

automate the dehusking process.

Low Cost Automation (LCA), the buzzword in all industrial firms generally

involves pneumatic, electrical as well as electronic components. LCA is important in the

automation of factories, for example, the electronic component assembly plants.

Automation saves a lot of tedious manual work and speeds up the production processes.

Agriculture is a potential area for automation. Automation can be applied for

activities like irrigation, harvesting, ploughing, weeding, etc. Our project aims at

automating the process of removing the outer shell of the coconut by help of pneumatics

and mechanical parts.

The following are the reason for automating:

To remove the husk easily

To increase productivity

To reduce manual power

To reduce the risks and accidents

To reduce labour cost and time consumption.

The following are the objectives of the project

1. To automate the process of Dehusking with low cost

Holding the coconut

Pressing the coconut into hook

Peeling the outer shell of the coconut

Control of the operation of the System.

2. To design, model and assembly of the components of the system.

3. To compare the various factors of dehusking for both present and the automated

system.

The following are the advantages of our system:

Improved safety

Increases the productivity.

Reduces the risk and accidents.

Avoids manual effort.

Reduces labor cost and time consumption.

METHODS OF ATTAINING AUTOMATION:

Automation can be attained by the following ways

Hydraulics

Pneumatics

Electric control

Due to the requirement of higher productivity we would like to go for fixed low cost

automation process.

Comparison between manual & Automatic

* Approximately

DESCRIPTION OF EQUIPMENT

MANUAL AUTOMATION

NO. OF

COCONUTS

/ hour

20* 30*

RISK MORE LESS

TIME MORE LESS

The complete equipment has been described under the categories of mechanical,

pneumatics, and Control Circuit.

1. MECHANICAL COMPONENTS

The various mechanical components of the system consists of the following

The base table is an important component of the system. The flange, rotating part and

other components of the system are mounted on the base table. The base table is designed

so that to withstand the shock load and vibrations generated by the system. The size of

the base table is 820 X 620 X 875mm.

HOOK BLADES:

Hooks are placed at the bottom of the shell. It is capable of piercing the outer shell of

the coconut. It is placed in the bottom inner circumference of the shell, so that all the

hooks can pierce into the shell of the coconut. It is made of high carbon steel (HCS)

which is sharp at the end. The high carbon steel is cut to required length and it is

hardened. The one end of the hook is very sharp and the other end is attached with the

bottom of the shell. As the hooks are very sharp, it can easily pierce into the shell of the

coconut. The reason for using high carbon steel is that to withstand the stress and

deformation developed in it, while peeling the coconut.

Base Table

CURVED SHELL

A Pair of shells is used, which has multi hooks present at its bottom and two cylinders

are attached to it. The coconut will be placed inside the shell and it will hold the coconut.

The pair of shells are made up of mild steel and attached to the base with help of

hinges present at its tangential curve. Hence the shell can be oscillated when the cylinder

moves linearly. Multi hooks are placed at the bottom of the shell. So that when coconut is

placed and pressed in the shell, the multi hooks get pierced into the shell. Also at the

bottom of the shell (opposite side of the shell where hooks are attached), hinges are

present to hold the piston of the cylinder. Hence when the piston is actuated, the shell

obtains oscillating movement as it attached with the base table with help of other hinges.

PNEUMATIC CYLINDERS

The pneumatic cylinder is an actuator, which converts air pressure into linear

motion. When the pressure on one side of the piston is relatively higher than on the other

side, it results in linear displacement. The speed of traversal is proportional to the

pressure difference.

1. DOUBLE ACTING CYLINDER

A "double-acting" cylinder has two ports through which the supply of air is

reversed to cause displacement in either direction. The general specification for a

pneumatic cylinder is in terms of the bore diameter of the cylinder, the stroke length of

the piston and the maximum operating pressure range.

To return the piston to its resting position, not only apply pressure to the second

port, but also open up the first port so that the gas in it can be expelled. In this project

double acting cylinders are used for the obtaining movement of the shell.

Specifications of double acting cylinder

2. SINGLE ACTING CYLINDER

A "single-acting" cylinder has a single port for compressed air. The forward

stroke takes place when the air is fed in the input port; the return stroke takes place when

the air supply to the input port is stopped. This is achieved by the spring force inside the

cylinder. When air pressure is removed; the cylinder does nothing to retract the piston.

Whatever the piston pushed out must push the piston back in. When air pressure is

removed, the spring pushes the piston back into the resting position. In some cases the

cylinder is sealed and the trapped air performs as an "air spring".

In this project the single acting cylinder is used to press and hold the coconut into

the shell.

PARAMETER VALUE

Make JANATICS

Stroke Length 160mm

Bore Diameter 40mm

Max Pressure 20 bar

DOUBLE ACTING CYLINDER

Specifications of single acting cylinder

DIRECTION CONTROL VALVE:

DCV’s are used to control the direction of flow of fluid through a pneumatic

system. In this project two direction control valves are used. The 2/2 single solenoid

DCV is used to actuate the single acting cylinders and 5/2 single solenoid spring return

DCV used to actuate the double acting cylinders. The specifications are given below.

Specification:

Double acting cylinder with solenoid Single acting cylinder with solenoid

Actuation Actuation

PARAMETER VALUE

Make JANATICS

Stroke Length 80mm

Bore Diameter 30mm

Max Pressure 20 bar

PARAMETER VALUE

Make JANATICS

Actuation Mechanism Solenoid

Return mechanism Spring

Actuating Voltage 230 V A.C

Type 5/2 valve

PARAMETER VALUE

Make AIRMAX

Actuation Mechanism Solenoid

Return mechanism Spring

Actuating Voltage 230 V A.C

Type 2/2 valve

SINGLE ACTING CYLINDER

ELECTRO – PNEUMATIC CIRCUIT:

To remove the outer shell of the coconut, three cylinders should be actuated in

synchronizing manner. Firstly, the press and hold cylinder is actuated and followed by

the shell actuating cylinders simultaneously. The press and cylinder is actuated by 2/2

single solenoid DCV and the shell actuating cylinders are actuated by 5/2 single solenoid

spring return DCV.

WORKING:

The working guidelines of the automatic coconut dehusking machine is explained below

Switch ON the system

Specify the mode of operation (manual or Automatic)

Check the input air supply is 12 bar

Use Emergency stop incase of any problem

SEQUENCE OF OPERATIONS FOR AUTOMATIC COCONUT

DEHUSKING MACHINE:

STEP PARAMETER FUNCTION

1 Cylinder 1 ON Press and hold the coconut

2 Cylinder 2 and

Cylinder 3 ON

and OFF

Performs the movement of shell

to peel the outer shell of the

coconut.

3 Cylinder 1 OFF Leaves the coconut freely.

Sequence of operations

Firstly, the coconut is placed vertically between two shells. Then auto mode or

manual mode is selected. Then press button is pressed which activates the solenoid to

actuate the single acting cylinder. Hence the coconut is pressed into hooks. Now all the

hooks in the pair shells will get pierce into the coconut. Then shell button is pressed in

the control box, which actuates both the double acting cylinder simultaneously. This

moves the shell in oscillating movement which removes the husk of coconut as the hooks

were present inside the coconut. Thus husk of the coconut removed separately by

automation.

CONCLUSION

The project highlights the following results:

Use of pneumatics arrangements instead of manual system.

Reduction of dexterity of human hands and provides safety to labour.

Reduction in the man power required for the dehusking process, since the process

is made automatic.

Automation of the dehusking process reduces the 2/3 of cycle time which

increases productivity.

Reduces the risk and accidents.

Extremely high speed operation

Simple and safe operation

Efficient use of space

Avoids manual effort.

Reduces labor cost and time consumption.

SCOPE FOR FUTURE WORK

The implemented Automatic Coconut Dehusking Machine can be made further

advanced by the following ways:

In our dehusking process, a closed loop control system using limit switches feed

back to electro – pneumatic circuit is used. In future, the microcontrollers and

PLC can be interfaced to making it as a flexible system.

Spring arrangements can be made for accommodating coconut of different

sizes.Separate conveyors can be used, one for collecting the coconut and the other

for collecting the husk.

BIBLIOGRAPHY

Pneumatic control - Werner Deppert / Kurt Stoll 1986

Pneumatic application - Werner Deppert / Kurt Stoll 1986

Automated assembly - jack. D.Lane (Society of Manufacturing Engg.Michigan,

1986)

Assembly and assembly automation- Dr.V.Radhakrishnan professor, IIT, Madras.

(Engg. Staff college of hyderabad.1986)

Strength of materials – R.K.Rajput

Fluid power-Anthony Esposito

Automation and production system - Mikell P Groover

Pro/e – user’s guide

Festo manuals

http://www.hypac.com

http://www.festo.com