REMOTE CONTROLLED SCREW JACK

Submitted in the partial fulfillment of the requirement for the award

“DIPLOMA IN MECHANICALENGINEERING ”

SUBMITTED BY:

1. S.BARANI 4. E.VIGNESH 2. S.MURALI 5. RAMAMOORTHY ANAND 3. N.S.VENKATESAN 6.

Under guidance of

Mr. N.MUTHUKUMAR

MARCH 2012

DEPARTMENT OF MECHANICAL ENGINEERING.

AMK TECHNOLOGICAL POLYTECHNIC COLLEGECHENNAI-602103

AMK TECHNOLOGICAL POLYTECHNIC COLLEGECHENNAI-602103

BONAFIDE CERTIFICATE

This is to certify that this Project work on

“REMOTE CONTROLLED SCREW JACK”

submitted by …………………… ……………. Reg. No. ……………

in partial fulfillment for the award of

DIPLOMA IN MECHANICAL ENGINEERING

This is the bonafide record of work carried out by him under our supervision during

the year 2012

Submitted for the Viva-voce exam held on ……………..

H.O.D. PROJECT GUIDE

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT

At the outset, we would like to emphasize our sincere thanks to the Principal

Mr. R.J.KUMAR M.E for encouragement and valuable advice.

we thank our Esquired Head of Department Mr R.RAJKUMAR M.E for

presenting his felications on us.

We are grateful on our Entourages Mr. N.MUTHUKUMAR for guiding in

various aspects of the project making it a grand success.

We also owe our sincere thanks to all staff members of the MTMR and

FOUNDRY Department.

Ultimately, we extend our thanks to all who had rendered their co-operation

for the success of the project.

CONTENTS

CONTENTS

CHAPTER NO. TITLE

1. INTRODUCTION

2. SYNOPSIS

3. CONSTRUCTION

4. WORKING PRINCIPLE

5. PRINCIPLE OF DC MOTOR

6. FORWARD AND REVERSE CONTROL

7. DESCRIPTION OF RELAY CONTROL

8. FEATURES OF MOTORISED JACK

9. ADVANTAGES

10. APPLICATIONS

11. MECHANICAL SPARE PARTS DIAGRAM

12. FINSIHING AND PAINTING

11. COST ESTIMATION

12. CONCLUSION

13. BIBILOGRAPHY

INTRODUCTION

INTRODUCTION

This project concentrates on providing descriptions of all the basic operating

principles and design of screw jack..

In our technical education the project work plays a major role. Every student

is put in to simulate life particularly where the student required bringing his

knowledge, skill and experience of the project work.

It helps how to evolve specifications under given constrains by systematic

approach to the problem a construct a work device. Project work thus integrates

various skills and knowledge attainment during study and gives orientation towards

application.

As the students solve the various problems exposed by the project work, the

students get the confidence to overcome such problems in the future life. It helps in

expanding the thinking and alternatives for future applications.

SYNOPSIS

SYNOPSIS

In current situation , car tire is removed for repair work a jack is used and it

is operated now by manually and not so easy to handle by the driver. In this

project , the screw jack unit is placed under the chassis unit which can be lifted by

operating the hand held remote control .

This screw jack is operated by a DC motor which is coupled to the main

screw rod of jack unit. The power supply for this jack unit is taken from the battery

which is already available in the same vehicle.

. The electrical power from the battery is given to electric motor through the

forward and reverse control relay with the help of two switches. One switch is used

for raising the chassis unit and the second switch is used for lowering the chase

unit.

Thus, by introducing this project in the automobile vehicle dual

advantage is obtained . One is the easy and convenient to operate and the tire

removal work is simplified.

CONSTRUCTION

CONSTRUCTION

The projects consists of

1. M.S . BASE FRAME

2. SCREW JACK

3. 12 VDC MOTOR.

4. ELECTRIC RELAY PANEL

5. REMOTE CONTROL UNIT

6. CONTROLLER UNIT.

1. M.S . BASE FRAME

This unit is fabricated in a M.S. “L” angle material having the size of 25 x 25

x 3 MM (L X B X T) . The jack unit is mounted on this base frame. The screw

jack unit is fitted under this chase unit..

3) SCREW JACK ASSEMBLY UNIT;

A jackscrew is a type of jack which is operated by turning a leadscrew. In the

form of a screw jack it is commonly used to lift heavy weights such as the

foundations of houses, or large vehicles.

4) 12 VDC Motor with built in speed reduction gear box;

This DC motor is shunt type 12V DC motor. This motor is having built in type

speed reduction gear box unit. It has high torque and low speed capacity. The

electrical supply to the motor is from 12 V DC battery. The DC Motor drives the

Jack mechanism. The Photo view of motor is shown below.

PRINCIPLE OF DC MOTOR

A DC motor is a dc machine working as a motor to convert dc electrical

energy into mechanical energy (dc) motor are very commonly used in cars, trucks,

aircrafts, etc. They are also used in large ratings, where wide range of speed control

is necessary.

When a conductor is carried a current and in lying in magnetic filed. Force

acting on the conductor. This is the principle of a Dc motor. The conductor is

housed in armature slots and current is applied from the dc source through brushes

and commutator. The field poles provide the magnetic field.

The construction of dc motor and generator are similar. However their

external appearance may be somewhat different. A motor has a rather closed frame

because it is may be operating in dusty environment and unskilled workers may be

working in its vicinity.

TYPES OF DC MOTOR

DC Shunt Motor:

This motor has medium starting torque, a speed regulation of 5 – 10 % and

excellent adaptability to adjustable speed service. It can be used for constant speed

drives like pumps, fans blowers, etc,. However for all these applications, a 3 phase

induction motor is preferable, because it ;is cheaper, more rugged and requires

lesser maintenance than dc motor. However a dc shunt motor is cheaper for low

speed drives. Moreover, whenever a wide range of speed control is required, dc

shunt motor is used. The main application of dc shunt motor is in steel and

aluminium, rolling mills and ward – Leonard speed control system.

Dc Series Motor:

This motor has a very high starting torque. Moreover it speed decreases with

increase in load torque. So that its power input remains more or less constant. It is

best suited for hoist cranes and traction. Speed control is generally obtained

through armature control. They are used for battery-powered vehicles.

Compound Motor:

A differential compound is rarely used. The characteristics of a cumulative

compounds motor depend on the relative strength of series and shunt fields. It has

good starting torque and dropping speed – load characteristic. They can be used for

pulsating loads needing flywheel action, viz. shears, conveyors, crushers, hoists,

plunger pumps, etc., Whenever the supply voltage is likely to vary considerably, a

compound motor is preferred. Because its induction and contribution to back emf,

the series field helps in reducing the fluctuations of current drawn from mains.

RATINGS OF MOTOR

Motors are rated by their voltage, current draw, output speed, and torque.

Operating Voltage

Operating voltage specifies the nominal (normal) voltage the manufacturer

recommends for the motor. Most small DC motors are designed for 1.5 to 12 volt

operation, with the majority in the 3-6 volt range. Larger DC motors designed for

heavy-duty applications usually require 12 to 24 volts, with some needing upwards

of 90 volts. Often, but not always, the higher the voltage, the more powerful the

motor (this does not apply to stepper motors, where very low voltages — on the

order of just a few volts — are common for heavy-duty motors). Most motors can

be run at operating voltages higher or lower than the specified rating. 

Lower voltages reduce torque and speed.

Higher voltages increase torque and speed.

(Note: For stepper motors, speed is not greatly altered by changing the voltage.)

Avoid applying excessively high voltages to a motor, or else it could overheat and

burn out. R/C servo motors contain their own electronics which are not designed for

use over about 7.2 volts. 

Current Draw

Current draw is the amount of current, specified in milliamps or amps, that the

motor requires to produce a certain amount of torque. Motors consume different

amounts of current depending on how they are operated:

 No-load. A motor that doesn’t have anything attached to its shaft isn’t doing

any work, and is said to be free-running. No-load current tends to be very low.

Load. As the motor does work, its load and current draw increases.

Manufacturers rate the current draw under load using different standards,

making it hard to judge a motor using this specification alone.

Stalled. When the motor shaft stops rotating, it “stalls” and draws as much

current as will flow through the windings. This specification is useful for

“worst case scenario” engineering planning.

Shorted. Maximum current flows into the motor when the coils are shorted

out.  The motor will not run, and like any short circuit, if operated in this way

for any length of time, serious damage can result to other systems on the robot.

Torque

Torque is the way the strength of the motor is measured. It is typically calculated by

attaching a lever to the end of the motor shaft, and a weight or gauge on the end of

that lever. The length of the lever usually depends on the unit of measurement given

for the weight. Examples:

 

Metric measurements use Newton meters (Nm), kilograms-force meters

(kgf-m), or sometimes gram-centimeters (gm-cm).

Standard measurements use ounce-inches (oz-in), or pound-feet (lb-ft), or

pound-inches (lb-in). It’s common to reverse the nomenclature and call it foot-

pounds and inch-pounds.

Speed

The speed of the motor indicates how fast its shaft is turning. DC motors without a

gearbox spin at 3,000 to over 12,000 RPM (revolutions per minute). With a gear

box, the speed can vary from under 1 RPM, on up.

Stepping motors are not rated in RPM, but pulses (or steps) per second. The speed

of a stepper motor is a function of the number of steps required to make one full

revolution, times the number of steps applied to the motor each second. Typical

values are 200 or 300 PPS.

5) ELECTRIC RELAY PANEL .

RELAY:

SPECPCATION OF RELAY:

a) Nature of supply: dc

b) Coil voltage: 12v

c) No of NO and NC contacts: 1

d) No of poles: single pole double throw

e) Shape of contact point: flat

f) Contact point material: silver or silver alloy

g) Type of relay: electro dynamic

TRANSMITTER AND RECEIVER:

These miniature RF modules provide a cost effective high performance FM

radio data link, as either 315, 433.92 or 868 MHz. Manufactured using later

trimmed thick film creaming hybrid the modules exhibits extremely stable

electronic characteristics over an industrial temperature range. These are no

adjustable components and ensure very reliable operation over time.

This transmitter and receiver pairs enables the simple implementation of a

data link at distances up to 5 meters in building and 25 meters open ground. These

transmitter and receiver modules are optimized for wireless transmission of encoded

data packets. To reduce development time and ensure reliability and security chips

from the RF solutions range encryption IC’s can be used to encode and decode the

data.

These modules will suit one to one and multi node wireless links in

applications including car and building security, inventory tracking, remote

industrial process monitoring and computer networking. Because of their small size

and low power requirements, both modules are ideal for use in portable, battery-

powered applications such as hand-held terminals.

CIRCUIT DETAILS

1. Micro controller system

2. Interface Circuit for stepper motor

3. Power supply (230V A.C. to 12 V and 5V DC)

4. Key Board Circuit

MICRO CONTROLLER SYSTEM:

This system monitors the engine condition by using PIC 16F870 (28 pin IC

Package) micro controller. The pin details of micro controller are shown in figure.

The circuit diagram for this micro controller board is shown below,

in no 2&5.The pin no 1 is RESET switch..The INPUTS are connected to

port B .The OUTPUTS are connected to PORT C.6 MHZ crystal is

connected to pin no 9,10.

POWER SUPPLY 5V DC AND 12V DC;

A 12 –0 v step down transformer is used to stepdown 230V AC to 12V

AC .This 12V AC supply is converted to 12V DC using four rectifier diodes. The

voltage from the rectifier section is regulated to 12V DC using 7812 IC . From 12V

DC the 7805 IC is used for regulating 5V DC for the power supply of

microcontroller.

the power supply circuit is shown in fig.

INTRODUCTION:

All the electronic components starting from diode to Intel IC’s only work

with a DC supply ranging from +5V to +12V. We are utilizing for the same, the

cheapest and commonly available energy source of 230V-50Hz and stepping down,

rectifying, filtering and regulating the voltage.

STEP DOWN TRANSFORMER:

When AC is applied to the primary winding of the power transformer, it can

either be stepped down or stepped up depending on the value of DC needed. In our

circuit the transformer of 230V/15-0-15V is used to perform the step down

operation where a 230V AC appears as 15V AC across the secondary winding.

Apart from stepping down voltages, it gives isolation between the power source and

power supply circuitries.

RECTIFIER UNIT:

In the power supply unit, rectification is normally achieved using a solid state

diode. Diode has the property that will let the electron flow easily in one direction

at proper biasing condition. As AC is applied to the diode, electrons only flow

when the anode and cathode is negative. Reversing the polarity of voltage will not

permit electron flow. A commonly used circuit for supplying large amounts of

DCpower is the bridge rectifier. A bridge rectifier of four diodes (4 x IN4007) are

used to achieve full wave rectification. Two diodes will conduct during the

negative cycle and the other two will conduct during the positive half cycle, and

only one diode conducts. At the same time one of the other two diodes conducts for

the negative voltage that is applied from the bottom winding due to the forward bias

for that diode. In this circuit due to positive half cycle D1 & D2 will conduct to

give 0.8V pulsating DC. The DC output has a ripple frequency of 100Hz. Since

each alteration produces a resulting output pulse, frequency = 2 x 50 Hz. The

output obtained is not a pure DC and therefore filtration has to be done.

The DC voltage appearing across the output terminals of the bridge rectifier

will be somewhat less than 90% of the applied rms value. Normally one alteration

of the input voltage will reverse the polarities. Opposite ends of the transformer

will therefore always be 180 degree out of phase with each other. For a positive

cycle, two diodes are connected to the positive voltage at the top winding.

FILTERING CIRCUIT:

Filter circuits which is usually capacitor acting as a surge arrester always

follow the rectifier unit. This capacitor is also called as a decoupling capacitor or a

bypassing capacitor, is used not only to ‘short’ the ripple with frequency of 120Hz

to ground but also to leave the frequency of the DC to appear at the output. A load

resistor R1 is connected so that a reference to the ground is maintained. C1, R1 is

for bypassing ripples. C2, R2 is used as a low pass filter, i.e. it passes only low

frequency signals and bypasses high frequency signals. The load resistor should be

1% to 2.5% of the load.

1000f/25V : for the reduction of ripples from the pulsating

10f/25V : for maintaining the stability of the voltage at the load side.

0.1f : for bypassing the high frequency disturbances

BLOCK DIAGRAM FOR POWER SUPPLY

STEP DOWN BRIDGE POSITIVETRANSFORMER RECTIFIER CHARGE

CAPACITOR

5V 12V REGULATOR REGULATOR

MOTHER DISPLAY BOARD BOARD RELAY

VOLTAGE REGULATOR:

The voltage regulators play an important role in any power supply unit. The

primary purpose of a regulator is to aid the rectifier and filter circuit in providing a

constant DC voltage to the device. Power supplies without regulators have an

inherent problem of changing DC voltage values due to variations in the load or due

to fluctuations in the AC linear voltage. With a regulator connected to the DC

output, the voltage can be maintained within a close tolerant region of the desired

output. IC7812 and 7912 is used in this project for providing +12V and 12V DC

supply.

1 5 TO 12 V DC DRIVE CARD

Here we have to drive the 12V DC load(MOTOR). The 5V signal

from the PIC 16F870 micro-controller is fed into the input of interface

circuit. SL100 transistor is used here for high speed switching purpose

and IRF 540N MOSFET is connected to the motor to handle the larger

current drawn by the motor.

WORKING PRINCIPLE

WORKING PRINCIPLE

The working principle of this MOTORISED JACK is explained in block diagram

Power supply12 VDC

230 V AC

ELECTRIC RELAYPANEL

This MOTORISED JACK has one 12 VDC motor. This DC motor drive is

transmitted to the jack unit through the screw rod .. The vehicle tyre is lifted up and

down by pressing the switch in the panel board. The 12 V DC supply is supplied

from the 12 V DC motor. The vehicle is moved up slowly without any sack .

12 V DCMOTORJACK UNIT

DESCRIPTION OF SCREWJACK

DESCRIPTION OF SCREWJACK;

A jackscrew is a type of jack which is operated by turning a leadscrew. In the form

of a screw jack it is commonly used to lift heavy weights such as the foundations of houses, or

large vehicles.

Contents A jackscrew operates this automotive scissors-jack.

Applications

A jackscrew's threads must support heavy loads. In the most heavy-duty

applications, such as screw jacks, a square thread or buttress thread is used, because

it has the lowest friction. In other application such as actuators, an Acme thread is

used, although it has higher friction.

The large area of sliding contact between the screw threads means jackscrews have

high friction and low efficiency as power transmission linkages, around 30%–50%.

So they are not often used for continuous transmission of high power, but more

often in intermittent positioning applications.

Advantages

An advantage of jackscrews over some other types of jack is that they are self-

locking, which means when the rotational force on the screw is removed, it will

remain motionless where it was left and will not rotate backwards, regardless of

how much load it is supporting. This makes them inherently safer than hydraulic

jacks, for example, which will move backwards under load if the force on the

hydraulic actuator is accidentally released.

Mechanical advantage

The mechanical advantage of a screw jack, the ratio of the force the jack exerts on

the load to the input force on the lever, ignoring friction, is

where

is the force the jack exerts on the load

is the rotational force exerted on the handle of the jack

is the length of the jack handle, from the screw axis to where the force is

applied

is the pitch of the screw threads; the distance between them.

However, most screw jacks have large amounts of friction which

increase the input force necessary, so the actual mechanical

advantage is often only 30% to 50% of this figure.

FEATURES OF MOTORIZED JACK

FEATURES OF THE JACK

It is compact in size

electrical power consumption is less

It can be utilized at our work shop

It is simple in construction

Low cost

Less weight and easy to handle

It reduces the man power

It is compact in size.

ADVANTAGES

ADVANTAGES

Comfort to the driver

The tyre can be removed without much more effort

This jack operation is simple.

The current consumption is very low

Simple in construction and easy maintained

It is compact in size and less weight

It is easy to operate with out hands-on training

APPLICATION

APPLICATION

It can be used as chase lifting system.

It is used in light vehicle l.

It is used in automatic remote control application by adding microcontroller

circuit..

MECHANICAL SPARE

PARTS DIAGRAM

FINISHING AND PAINTING

FINISHING AND PAINTING

JOB PREPARATION;

Before welding, remove any bend in the L angle with the sludge hammer on the

anvil block. Then it is cut to the required length with the hacksaw blade and

fabricated to required dimensional shape with arc welding.

FINISHING OPERATION BEFORE PAINTING;

After welding, any slag on the welded area is removed with the chipping hammer

and cleaned with the metal wire brush. Then all the surfaces are rubbed with the

emery sheet.

Metal primer is applied on the surfaces with the brush .After drying the metal

primer, the second coating is applied with the paint.

COST ESTIMATION

COST ESTIMATION

1. JACK unit - 700.00

2. 12 V DC Motor - 1000.00

3. REMOTE CONTROL UNIT - 800.00

4. M.S. FRAME - 600.00

5. Relay 2 Nos - 600.00

6. CONTROLLER UNIT - 1800.00

7. PUSH BUTTONS & WIRES - 200.00

8. MOTOR COUPLER UNIT - 300.00

9. METAL PRIMER - 100.00

---------------

6000.00

-------------------

CONCLUSION

CONCLUSION

We make this project entirely different from other projects. Since concepts

involved in our project is entirely different that a single unit is used to various

purposes, which is not developed by any of other team members.

By doing this project work, we understood the working principle and uses of

relay,screwjack and DC motor etc.,

.

Once again we express our sincere thanks to our staff members.

BIBLIOGRAPHY

BIBLIOGRAPHY

1. A course in Automobile Technology - R.S. Khurumi

2. Electrical Technology - B.L. Theraja

3. Automobile Technology - R.S. Khrumi

www.google.com

PHOTO VIEW