DESIGN PROJECTS

REPORT

ON

DEVELOPING A NEW CAR JACK

BY

ALLEN ANILKUMAR 2010H141026G

SANDEEP PATIL 2010H141028G

UDAY PULELLA 2010H141029G

NISSIM J. DOLE 2010H141032G

Submitted to

Prof. B. J. C. Babu

BIRLA INSTITUTE OF TECHNOLOGY & SCIENCE, PILANI

K. K. BIRLA GOA CAMPUS

November 2011

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ACKNOWLEDGEMENT

We are very grateful to our guide Prof B.J.C. BABU, Mechanical Engineering

Department for giving us the opportunity to work under them in this project and for their

constant guidance and inspiration throughout the project. This project required a lot of input

from the members other than the team. We are truly grateful to those people who gave us

their valuable time and input for the customer survey form. We are grateful to our friends

from the Non-engineering background who gave us thoughts and insights about several

aspects. We are thankful to all, who directly or indirectly were involved in this project.

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CONTENT

I. Introduction 4

1. Project Title 5

2. Mission statement 5

3. Customer need from survey 6

4. Interpreted and sorted needs 7

5. Product specification and comparison 8

6. Summary of technology 10

7. Product function, Function structure and FAST diagram 13

8. Concept generation 17

9. Concept screening and selection 19

10. Conclusion 20

II. Appendix 1 21

III. Appendix 2 26

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I. INTRODUCTION

As we know that screw jack existing in this world long ago. Jacks are having

applications in myriads of areas like ranging from lifting the vehicle for removing punctures

or underbody overhaul to raising heavy structures like bridges or columns of the buildings. In

our day today life we required Jacks to lift the car when it has flattened tires. Jacks differ in

their properties according to the type of vehicle they are required for. These are mechanical

devices which are portable and hence can be stored in the vehicle. The vehicle owner must

ensure that he/she has to have a jack in his vehicle so that if there is no garage nearby, one

can at least fix his vehicle himself. It is always a good idea to be aware of all the necessary

devices that are required for your vehicle. This will ensure that if ever your car breaks down

you can fix it by using these tools. If you are a car owner then you may have certainly visited

a garage where there are all types of equipment that are necessary to repair the car.

However the type of Screw jack commonly used in motor vehicles are of mechanical

scissor type or simple screw jack. Typically scissor kind of screw jacks is widely used in

hatchbacks as well as in the sedans like Maruti 800, Swift, indigo, Skoda etc. When one use

these kinds of jacks he/she needs to apply comparatively large efforts to lift the car. These are

comparatively more incasing of scissor jacks as it is having short crow bar. These

applications of force depend particularly on age, gender and knowledge of particular person.

So as to reduce the efforts for lifting the vehicle we are working on the on these jacks and

trying to implicate some contraption or kind of mechanism. To achieve our task we followed

the methods what we had been taught and studied in Product Design. We applied these

techniques to achieve our target and formulated various solutions.

This report is categorised into the following

1. Project Title

2. Mission statement

3. Customer needs

4. Interpreted and sorted needs

5. Product specifications

6. Summary of technologies

7. Production Functions, Function tree, FAST diagram.

8. Concept generation9. Concept scoring and selection10. Conclusion

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1. PROJECT TITLE

Project Title:

Implementation of product design principles to explore possibilities of new car jack

designs.

2. MISSION STATEMENT

Product description: Is a device that lifts heavy equipment like automobiles

Key business goals: Advancement of jack technology

Market capitalisation

Primary market: Leading 4 wheeler original equipment manufacturer

Secondary market: Automobile service stations and small scale enterprises

Assumptions: Portable, Reliable, Light weight, Compact

Stake holders: End customer, Retailer, Manufacturer

Avenues for creative design: Size, power consumption

Scope limitations: Weight, compatibility issues

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3. CUSTOMER NEEDS

A customer survey was conducted using the internet. The summary of the survey is

described in appendix I.

Further the customer needs for carjacks were found out as follows

1. The jack ought to lift the vehicle

2. It must be easy to position

3. It should have more area for placement

4. It should have Less energy requirement

5. It is good if take less time for lifting

6. It should be compact

7. It must be easy to operate

8. It is nice if it uses less maintenance

9. It is good to have corrosion resistance

10. It should be reliable

11. It must be portable

12. It is good if it is compatible with all car models

13. It is nice if it could be easily to operated in low light

14. It should be light in weight

15. It has be affordable

16. It should not damage any part of the chassis

17. It must not be noisy

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4. INTERPRETED AND SORTED NEEDS

The customer needs obtained in the previous section were interpreted by the design team.

We found seven broad categories of interest. The needs were sorted under these seven

categories.

The need number (for reference in section 5) is given in brackets

I. Purchase1. Cost (1)

II. Store1. Portable (2)2. Compact (3)3. Light weight (4)

III. Mounting1. Easy to position (5)2. Wide base (6)3. Portable (7)4. No damage to chassis (8)5. Low light visibility (9)

IV. Lifting1. Raising the car (10)2. Compatibility with all car models (11)3. Quick operation (12)4. Less energy requirement (13)5. Stable positioning (14)

V. Lowering1. Slow descent (15)2. Smooth operation (16)3. Stable positioning (17)

VI. Un-mounting1. Easy removal (18)2. No damage to chassis (19)3. Low light visibility (20)

VII. Usability1. Simple usage (21)2. Less maintenance (22)3. Corrosion resistance (23)4. Light weight (24)5. Compatible with all car models (25)6. Silent operation (26)7. Easy usage in low light (27)

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5. PRODUCT SPECIFICATIONS

From the interpreted customer needs, the product metrics have been deduced as in table 1.

METRIC NO.

NEED NO.

METRICIMPORTANC

EUNITS

1 10 Raise of the car 5 h(mm)

2 13Energy

requirement5 T(Nm)

36,14,1

7Stable position 4 A(mm2)

4 5 Positioning 3 NA5 18 Removal 3 NA

6 8,19 Minimum Damage 4Dent, Ding

7 12 Operating time 4 t(s)8 15 Lowering time 4 t(s)9 21 Usability 3 NA10 22 Maintenance 3 Rupees11 4,24 Lightweight 3 M(Kg)

12 26 Silent operation 2Noise(dB

)13 16 Smooth operation 3 NA14 3 Compact 4 NA15 2 Portable 4 NA

169,20,2

7Darkness visibility 4 Lumax

17 1 Cost 4 Rupees18 11,25 Compatibility 3 NA19 23 Corrosion 3 NA

20Bureau of Indian

STD3 NA

Table1. Product metrics

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We also compared three existing jack models and found out marginal and target

specifications. Hence table two has been prepared for comparison between the existing

models.

MET. NO.

METRIC UNITSINSTA

JACK 2.5TAKM 30 SJ35T

INSTA JACK 2.5T

AKM 30

SJ35TMarginal

valueIdeal value

1 Rise of the car h(mm) 260 350 440 ** *** **** >255 >550

2 Energy requirement T(Nm) 35 40 27 *** ** **** >25 <20

3 Stable position A(mm2) 220 350 300 ** *** *** >225 >500

4 Positioning NA GOOD FAIR FAIR **** ** **

5 Removal NA FAIR GOOD FAIR ** *** **

6 Minimum Damage Dent,Ding FAIR FAIR FAIR *** *** *** >450 <200

7 Operating time t(s) 1200 2000 2400 **** *** *** >1200 <600

8 Descendance t(s) 450 420 450 *** **** *** >420 <300

9 Usability NA GOOD POOR FAIR *** ** **

10 Maintainance Rupees 150 175 150 *** ** *** >50 <As small

11 Lightweight M(Kg) 6 5 7 **** ***** *** >10 <5

12 Silent operation Noise(dB) 5 5 5 **** **** **** >20 <5

13 Smooth operation NA GOOD POOR FAIR **** ** ***

14 Compact NA GOOD FAIR FAIR **** *** *** >1-2min <2 min

15 Portable NA EXCELLENT FAIR FAIR ***** *** *** >Fair Excellent

16 Darkness visibility Lumax NA NA NA * * * >fair Excellent

17 Cost Rupees 2000 1500 1400 ** *** *** >1300 <1100

18 Compatibility NA FAIR POOR POOR **** ** ** Domestic All

19 Corrosion NA OIL PAINT GALVANIZEDOIL

PAINT*** **** *** oil paint galvanized

20Buereau of Indian

STDNA FAIR FAIR FAIR *** *** *** As per As per

Table2. Marginal and Ideal values for the product metrics

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6. SUMMARY OF TECHNOLOGY

The project team made a survey of the existing jack technologies and arrived at the

following findings.

Graph1. S-curves

A mechanical jack is a device which lifts heavy equipment. The most common form

is a car jack, floor jack or garage jack which lifts vehicles so that maintenance can be

performed. Car jacks usually use mechanical advantage to allow a human to lift a vehicle by

manual force alone. More powerful jacks use hydraulic power to provide more lift over

greater distances. Mechanical jacks are usually rated for a maximum lifting capacity (for

example, 1.5 tons or 3 tons

Hydraulic jack

Hydraulic jacks are typically used for shop work, rather than as an emergency jack to

be carried with the vehicle. Use of jacks not designed for a specific vehicle requires more

than the usual care in selecting ground conditions, the jacking point on the vehicle, and to

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ensure stability when the jack is extended. Hydraulic jacks are often used to lift elevators in

low and medium rise buildings.

A hydraulic jack uses a fluid, which is incompressible, that is forced into a cylinder

by a pump plunger. Oil is used since it is self-lubricating and stable. When the plunger pulls

back, it draws oil out of the reservoir through a suction check valve into the pump chamber.

When the plunger moves forward, it pushes the oil through a discharge check valve into the

cylinder. The suction valve ball is within the chamber and opens with each draw of the

plunger. The discharge valve ball is outside the chamber and opens when the oil is pushed

into the cylinder. At this point the suction ball within the chamber is forced shut and oil

pressure builds in the cylinder.

In a bottle jack the piston is vertical and directly supports a bearing pad that contacts

the object being lifted. With a single action piston the lift is somewhat less than twice the

collapsed height of the jack, making it suitable only for vehicles with a relatively high

clearance. For lifting structures such as houses the hydraulic interconnection of multiple

vertical jacks through valves enables the even distribution of forces while enabling close

control of the lift.

In a floor jack (aka 'trolley jack') a horizontal piston pushes on the short end of a

bellcrank, with the long arm providing the vertical motion to a lifting pad, kept horizontal

with a horizontal linkage. Floor jacks usually include castors and wheels, allowing

compensation for the arc taken by the lifting pad. This mechanism provides a low profile

when collapsed, for easy manoeuvring underneath the vehicle, while allowing considerable

extension.

Pneumatic jack

A pneumatic jack is a hydraulic jack that is actuated by compressed air - for example,

air from a compressor - instead of human work. This eliminates the need for the user to

actuate the hydraulic mechanism, saving effort and potentially increasing speed. Sometimes,

such jacks are also able to be operated by the normal hydraulic actuation method, thereby

retaining functionality, even if a source of compressed air is not available.

House jack

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A house jack, also called a screw jack is a mechanical device primarily used to lift

houses from their foundation. A series of jacks are used and then wood cribbing temporarily

supports the structure. This process is repeated until the desired height is reached. The house

jack can be used for jacking carrying beams that have settled or for installing new structural

beams. On the top of the jack is a cast iron circular pad that the 4" × 4" post is resting on.

This pad moves independently of the house jack so that it does not turn as the acme-threaded

rod is turned up with a metal rod. This piece tilts very slightly but not enough to render the

post dangerously out of plumb.

Strand jack

A strand jack is a specialized hydraulic jack that grips steel cables; often used in concert,

strand jacks can lift hundreds of tons and are used in engineering and construction.

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7. PRODUCT FUNCTION, FUNCTION TREE, FAST DIAGRAM

For the purpose of breaking down the entire jack functions into simple ones, the project team

started from the folowing black box diagram.

Black box diagram

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FAST diagram

After developing the black box, to study, analyze and understand the product functions, how

the functions relate to one another, and which functions require attention to increase the

product value, the FAST diagram was constructed. It helped to display the functions in

logical sequence, prioritize them and test their discrepancies

From the FAST diagram, three main sub functions were identified and function structures

were drawn for each. The separate function trees are shown below.

Sub function1. Mounting

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Sub function2. Raising

Sub function3. Lowering

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The three structures were combined to form the total function structure as

Function structure

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8. CONCEPT GENERATION

The above function structure was used to identify probable areas for innovation. The team

identified that newer energy sources could be explored. For this reason we chose the various

members in column A of table 3.

Table3. Concept combinations

The above table would lead to 5*4*5=100 combinations. Hence we considered only viable

options. We eliminated various alternatives and ended up with the following combination

table.

Table4. Viable concept combinations

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At this stage, the team ended up with 15 concepts made from the combinations of the above

alternatives and one additional concept (concept 16- refer sketches for details). These 16

combinations were taken forward for concept screening.

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9. CONCEPT SCORING AND SELECTION

For the purpose of concept scoring, we considered the interpreted needs from section 4 and

ended up in five criteria: Ease of use, quickness of operation, efficiency, portability and

affordability. We gave rating to each of these five criteria and formulated the following

scores for each of the 16 concepts.

Sl No.

ConceptCriteria

Total score

Ease of use

Quickness of operation

EfficiencyPortabilit

yAffordabilit

yRating in

10035 10 15 20 20

1 A1B3C1 1 1 4 3 5 265

2 A1B3C2 1 1 5 5 4 300

3 A1B3C3 1 1 4 4 4 265

4 A2B3C1 3 3 5 4 1 310

5 A2B3C2 4 2 3 3 3 325

6 A2B3C3 2 1 3 3 3 245

7 A3B3C1 2 4 3 5 4 335

8 A3B3C2 2 3 2 4 4 290

9 A3B3C3 2 2 2 4 4 280

10 A4B3C1 5 5 4 4 1 385

11 A4B3C2 5 4 5 5 3 450

12 A4B3C3 4 4 4 4 2 360

13 A5B3C1 4 5 4 2 1 310

14 A5B3C2 4 4 5 3 3 375

15 A5B3C3 3 4 4 2 2 285

16 Balloon 3 1 3 5 5 360

Table5. Concept scoring

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10.CONCLUSION

With the help of this exercise we are able to gather the vital customer needs about the

product car jack and its usage. These methods also helps in revealing the problems or

difficulties end users are facing. To reduce the difficulties faced by the users we applied

techniques such as FAST method, Function structure to understand thorough working of the

screw jack. To generate the technical specification we collected the information of existing

jacks of various manufacturers and compared them against the interpreted and grouped

customer needs. From these techniques we are able to specify the nominal and marginal

values for the screw jack. By means of concept generation we are able to develop around 100

concepts however out of that we zeroed on viable 16 ideas. These ideas are generated by

means of concept combination. Each and every idea was later screened against specific

criteria. In the end we inferred that Concept 11 (Car battery operated 4 bar mechanism in

direct contact with chassis) is the best design. This concept results in drastic reduction of user

effort for lifting the vehicle.

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APPENDIX I

Appendix I consists of the questionnaire which we have developed for gathering the vital

customer needs. From this method we categorized the grouped needs and interpreted

need. This technique helps us in devising the concept generation and concept selection.

The summary of the survey is as follows

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How often do you have a flat tire?

22

Where you able to position jack properly?

23

24

How much did it take for you to install the jack and lift the vehicle?

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APPENDIX II

Sketches of concepts:

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27

28

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