Design Manufacture And Testing Of A Car Tyre Inflating System

ABSTRACT

This paper detail the design and fabrication of a portable car tyre inflator to deliver compressed air at high pressure (200kpa). The aim is to build a working proto-type of a portable car tyre inflator and test it for efficiency and effectiveness. The device has a mass flow rate of ṁ=7.09x 10^-6 kg/s and a volumetric flow rate of VD=3.55×10^-2 m³/s. it was designed to pump a deflected non punctured car tyre in the shortest possible time of about 3-5minutes. The tyre inflator device comprises a single cylinder reciprocating compressor, gear drive, a dc electric motor, a dc battery of 12V 75A, transformer, etc. The device is to be connected to the car battery via the cigarette lighter socket provided in the car. The design consideration, analysis and calculation are based on thermodynamic principles of positive displacement reciprocity machine, strength and rigidity of the mechanical element. The materials selected for the design are so chosen in view of economy, light weight and compatibility for easy handling. The device was tested after fabrication and it was found to be very efficient in its performance. 10 car tyres were inflated with the device and it was found that the time it took to inflate the tyres was with the time range of 3-5 minutes, showing that it objective was achieved. The functioning of the compressor was appreciable in all the tests conducted delivering a volumetric efficiency of 0.85 about 85% which shows more air is been used in the piston compression stroke.

Keywords – Tyre, Inflator, Mass Flow Rate and Volumetric Flow Rate.

 TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• PROBLEM STATEMENT
• AIM AND OBJECTIVES OF THE PROJECT
• ADVANTAGES OF PROJECT
• LIMITATION OF THE PROJECT
• APPLICATIONS OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF THE STUDY
• ORIGIN OF CAR TYRE INFLATING SYSTEM
• ORIGIN OF CAR TYRE INFLATING SYSTEM
• REVIEW OF RELATED WORKS
• PNEUMATICS NEED OF COMPRESSED AIR
• SELECTION OF PNEUMATICS
• PRODUCTION OF COMPRESSED AIR
• RECIPROCATING COMPRESSOR
• CHARACTERISTICS OF COMPRESSED AIR
• CHARACTERISTICS OF PNEUMATICS

CHAPTER THREE

MATERIALS AND METHOD

• METHODOLOGY
• MATERIAL SELECTION
• DESIGN SPECIFICATION
• DESIGN OPERATION SEQUENCE
• THE DESIGN THEORY AND FORMULAE
• DESIGN CALCULATION OF THE RADIAL STRESS ΔR, AND THE TANGENTIAL STRESS ΔT IN THE CYLINDER
• DESIGN CALCULATIONS FOR THE DELIVERY PRESSURE

CHAPTER FOUR

• RESULT AND DISCUSSION

CHAPTER FIVE

5.1     SUMMARY AND CONCLUSION

REFERENCES

CHAPTER ONE

1.0                                           INTRODUCTION

1.1                              BACKGROUND OF THE STUDY

The automobile is one of the sectors that play a big role in the economics of all the countries of the world. One of the most critical problems of vehicle is the correct performance of the tyre. Making sure that tyres are inflated for the right amount of pressure for the load being carried and for the right road condition can lead to preservation of tyres and this will generally result into optimal vehicle operation without any risk (Fowler et al, 2009).

Worthy of note is the fact that incorrect inflation of pressure in tyre affects vehicle handling, passenger’s comfort, braking conditions, reduction in fuel economy as well as tyre life span. Hence, there is a great need to pay serious attention to tyre pressure condition (Autos and Boats, 2014).

Wheel being one of the major parts of an automobile vehicle, comprises tyre and rim in which the tyre is filled with compressed air. The pressure of tyre contributes significantly to the overall efficiency of automobile vehicles and must be kept within the prescribed range.

According to America Automobile Association, 80% of Vehicles have at least one under inflated tyre and when the pressure of the tyre is below 2 psig than the ideal pressure, the fuel efficiency is reduced by 10% (Mushiri et al, 2016).

Inflation of tyres is done by the help of an air compressor also known as inflator. An air compressor is a device that converts power into potential energy by forcing air into a smaller volume and thus increasing its pressure (Timothy, 2014). Finite Element analysis as a powerful and economic method has been used widely for Engineering designs (James, 2014).

The importance of Central Tyre Inflation (CTI) system which permits a vehicle operator to optimize tyre and vehicle performance  by varying inflation pressures in response to changing operating conditions such as load being carried, road condition and vehicle speed while the vehicle is in motion was emphasized by (James, 2014).

Car tyres are the only part of the car that have contact with the road. Tyres are fitted on the rims and inflated (Fowler, 2009). Safety in acceleration, steering, cornering and braking depends on tyre’s contact with the road. There are different types of tyres, ranging from radial ply to self-supporting run flat. These tyres must be kept at correct pressure for optimum performance. Driving over pot-holes, kerbs, pointed objects even at low speed can cause puncture which results in flat tyres.

However, when tyre pressure decrease it makes the car to be unbalanced, it also affects the speed of the car and can cause damage to the tyre. Therefore, the need to inflate the tyre when the pressure reduce cannot be over emphasized. Hence this work tends to proffer solution to drivers whose tyre pressure has reduced, especially when the place to volcanize the tyre is not close at hand.

2.2                                    PROBLEM STATEMENT

Often times, many car/ vehicle owners inflate tyres without a recourse to the recommended optimum inflation pressure for specific cars. Correct tyre inflation is of great importance not only to service life of the tyre but also economic, handling characteristics and the safety of  the tyre and human life. Driving an under-inflated tyre has serious negative consequences on tyre durability, steering response, directional stability, fuel efficiency which impacts on higher rolling resistance and low mileage.

Putting into consideration time factor and availability of a vulcanizer stand most especially while on a long journey is dangerous and time wasting, and it is obvious that the existing way of maintaining the pressure level of an automobile vehicle tyre is too tedious. The problem will be more complex and dynamic if the tyre pressure level can no longer sustain the vehicle in motion in addition to an already deflated spare tyre along an area where people do not live. The design presented in this work is therefore geared towards improving the efficiency of automobile tyres and reducing cost as well as time spent in looking for a vulcanizer stations whenever vehicle tyre got deflated.

1.3                                                    AIM AND OBJECTIVES

The main aim of this work is to manufacture a car tyre inflating system that has the capability to adjust the pressures in all four tires of a passenger vehicle to obtain the proper pressure for varying road/driving conditions. Specifically, the objectives are:

• To maintains the required tyre pressure
• The automatic system saves human energy & time in filling the air in tyres when they are in under inflated
• To builds a Low-cost system
• Improves fuel efficiency & tyre life: This system helps in less consumption of fuel and also improves tyre life by reducing chances of wear in
• To replace the traditional or existing means of inflating tyre

1.4                                                              ADVANTAGES OF PROJECT

There are many dangers to having under inflated tyres, because they are designed for use at their recommended pressure. Under inflation can lead to increased deformation in the tyre wall as it concentrates the load upon the tread shoulders, this reduces the amount of surface contact the tyre has with the road. This can have many consequences.

• Increased wear of the tyres treads which will lead to a higher chance of aquaplaning in the
• Reduced handling characteristics and a reduced control of the vehicle.
• Longer stopping
• Higher chance of the tyre delaminating, which could lead to a sudden tyre

Manufacturing this machine serves as a way of stopping these consequences.

1.5                                                              LIMITATION OF THE PROJECT

• High capital investment
• In measurement of high pressures, cost of sensors is
• Higher temperature will affect the proper working of the sensors.

1.6                              APPLICATIONS OF THE PROJECT

The area of application of a car tyre inflating system is as below:

• Automobile Application
• Car Manufacturing Industry
• All two-wheeler application
• All four-wheeler applications