TITLE PAGE.

REPORT FOR A RACING CAR COIL SPRING CARRIED OUT AT THE UNIVERSITY OF BOLTON.MSP4001 CHASSIS AND ELECTRONIC PRINCIPLES.6TH AND 7TH OF MAY 2015.JAMES AUGUSTUS.

AKINWUMIJU BENJAMIN OLUWASEGUN 20277275.

FD. MOTORSPORTS TECHNOLOGY.

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ABSTRACT.

1.1 TITLE PAGE.

1.2 ABSTRACT.

1.3 TABLE OF CONTENT.

1.4 INTRODUCTION.

1.5 MAIN BODY

.

1.6 DATA TABLE AND GRAPH.

1.7 HYSTERESIS.

1.8 CALCULATION FOR DISPLACEMENT.

1.9 PROCEDURE AND PROCESSES USED IN MANUFACTURING COIL SPRINGS.

2.0 CONCLUSION.

2.1 REFFERENCES.

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TABLE OF CONTENT.

(1) ABSTRACT (Page 2).

(2) TABLE OF CONTET (Page 3).

(3) INTRODUCTION (Page 4).

(4) THE MAIN BODY (Page 5 – 9).

(5) CONCLUSION (Page 10).

(6) APPENDIXES (Page 11 - 13).

(7) REFFERENCES.

INTRODUCTION3 | P a g e

Coil springs are mechanical equipment made of mechanical devices that basically help in storing energy due to the force applied on it by absorbing and releasing it in order to control the force in between the two surfaces that are in contact for example an absorber shock. The springs are made in form of an elastic material that are formed into coil shapes so that they can compress and also return to their original length when unloaded. There are three various forms of springs which are;

(1) Compression springs. (Found in valve of a Gasoline Engine).(2) Extension Springs. (Found in vice-Grip Pliers)(3) Torsion Springs. (Found in Car Engines)

An example of a compression spring is the coil spring, due to the materials is made up of, torsion springs can be compressed or extended and the quality of a coil spring can be known by the amount of energy it can withstand when it is been tested. Because a coil spring that is capable of absorbing the greatest amount of energy when been tested is the best. Metal coil springs are been manufactured by winding up the wires around a shape former which gives the spring the shape needed. For a cylindrical Coil Spring one we need a cylinder to get the shape.

Before springs are been manufactured there are things to be put into consideration for example; (1) the heavier the wire, the stronger the spring.

(2) The smaller the coil, the stronger the spring.

(3) The more number of working coils we have, the lesser the load you will need to apply to it in order to get it move to a certain distance.

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MAIN BODYThis exercise was carried out at the University of Bolton by using a race car compression coil spring in order to know the forces and the deflection of the coil spring.

We started by taken the measurement of the spring with a Vernier calliper before placing it on the spring deflection rig. We started by taking the following measurement below;

(1) Length. 125.42mm

(2) Inside Diameter. 58.03mm

(3) Outside Diameter. 81.99mm

(4) Diameter Thickness. 12.12mm

(5) Distance between Coiling’s (Top) 12.83mm

(6) Distance between Coiling’s. (Middle) 14.55mm

(7) Distance between Coiling’s. (Bottom) 13.16mm

(8) Number of Coiling’s. 5

After taken the basic measurement we then proceeded into the main experiment by placing the coil spring on the spring deflection rig, then set the reading metre to zero point. And after that a force is been placed on the coil spring the reading is been taken and then place another force on the spring from the initial reading not setting it back to zero point then take the readings and so on. This is done quite a number of times and the following readings below are obtained;

FORCE (kg). DISPLACEMENT (mm).

0 060 3.75117 5.63

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178 7.64240 9.63302 11.63364 13.64420 15.49477 17.33532 19.13

Below is a graph showing the Force (kg) against Displacement (mm).

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HYSTERESIS, the term hysteresis can simply be defined as the after effect of an engineering material after being worked out. For example, when taken a measurement of a body on a weighing scale, if you step on the scale gently you will get your actual body weight as the readings on the scale rises up. Compare to when you jump on the scale with a force, the readings shoots up and then goes down after to give the actual body weight. So the difference in the changes between the readings and the force applied to the scale is referred to as Hysteresis.

In the case of the coil spring used for the experiment, there was an evidence of hysteresis after the experiment. The actual readings taken on the coil spring during the experiment was carried out was not the same as the final reading when the data’s were been used to calculate the displacement at 500(kg) so, after the experiment was been carried out and comparing the two results I could see there was an evidence of hysteresis.

To calculate the displacement of the spring when there is a load on it, the following formula will have to be applied;

Slope of a graph where;

Y= mx + c.

Y= Y value = Force.

X= x value = Displacement.

M= Slope of graph (Gradient).

0= C= where the slope crosses the Y axis.

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According to the data from the experiment I realised that there is a distortion on the line from the starting point to the first data which is 3.75 (mm) when the load was been placed on the coil spring.

Like I rightly mention in the early part of this report, a spring is a mechanical device that help in storing energy whenever a force is been placed on it by absorbing and releasing it when needed. Springs are to be designed in order to meet the quality of their demands in terms of flexibility, and the environment in which are going to be exposed. The springs are manufactured in two major processes, (1) the pre-heat treated (oil-quenched) and (2) Annealed (unquenched) in which wire is used for the production.

The pre-heat treated, with this type of process there is use of wire and the springs will be stress free after the coiling process.

But in the case of Annealed, the wires used are been tampered with and will be hardened after the coiling process in order to get high quality strength. And in both cases the steel done in these two different processes will have the same spring quality process in terms of their characteristics.

The processes used for the coiling are;

(1) Cold Coiling.

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(2) Heat Treatment.(3) Grinding.(4) Shot Peening and Pre-setting.

(1) Cold Coiling, in the cold form process the wires used are formed into spring through the help of a machine that is been controlled by a computer controlled automatic coiling machine.

(2) Heat Treatment, this method is also used in the process of coil making by heating the steel used to a certain temperature in order to make the steel more hardened or a softer material.

(3) Grinding, in this process the coil springs end will be grinded after production so as to allow the spring edges fits into the seats or the place they would want place them. This is also done by the use of a computer controlled spring grinding machines.

(4) Shot Peening and Pre-setting, when the coil springs are been cooled down in the treatment, there is need to reduce the stress on the spring during compression, this is done by introducing and controlling the level of positive residual stresses in the material by the process of shot peening and pre-settings in order to raise the spring to its highest performing level. This process also helps in preparing the spring material ready for surface treatment which is been processed in zinc phosphate and painting.

In terms of the costing for a coil spring for a typical road saloon car to that of a performance racing car. Basically on a normal road saloon car the compression coil spring work alongside with the dampers fitted to the car in other to assist the car whenever they are in contact with bumps and humps on the road, and also the coil spring carries the sprung materials on the car like the; (1) the chassis, (2) the engine, (3) transmission, (4) the driver and so on. But in the case of a compression coil spring on a race car, the springs are been produce in order to maximize the ride height of the car by adjusting it to a certain height on the race track, and not for the drivers use. Springs on a racing car is more expensive than that of a saloon road car. The coil spring on a racing car has to be designed in order to meet the quality of their demands in terms of flexibility and thickness so as to withstand the weight of the car and other sprung materials fitted to the car, unlike that of a saloon car that is been assisted by a damper.

To get the best quality for a racing car coil spring, it will cost more money in terms of production than that of a saloon road car.

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CONCLUSION.

Basically compression coil springs help in storing energy due to the force applied on it by absorbing and releasing it in order to control the force in between the two surfaces that are in contact for example an absorber shock. Springs are like elastic material that are formed into coil shapes so that they can compress and also return to their original length when unloaded. The three forms of springs are (1) Compression springs. (2) Extension Springs. (3)Torsion Springs.

Before springs are been manufactured there are things to be put into consideration for example; (1) the heavier the wire, the stronger the spring.

(2) The smaller the coil, the stronger the spring.

(3) The more number of working coils we have, the lesser the load you will need to apply to it in order to get it move to a certain distance.

The coil spring on a racing car has to be designed in order to meet the quality of their demands in terms of flexibility and thickness so as to withstand the weight of the car and other sprung materials fitted to the car, unlike that of a saloon car that is been assisted by a damper. Due to this, it makes it more expensive to produce than that of a normal road saloon car.

In the case of the coil spring used for the experiment, there was an evidence of hysteresis after the experiment. The actual readings taken on the coil spring during the experiment was carried out was not the same as the final reading when the data’s were been used to calculate the displacement at 500(kg) so, after the experiment was been carried out and comparing the two results I could see there was an evidence of hysteresis.

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APPENDIXES.

IMAGES OF COIL SPRINGS.

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REFFERENCES.

European springs and pressings ltd, compression springs and compression springs manufactural 2015.

http:// home.endlink.net/bazillion/intro.html. Page 1 – 5 Educypedia.

www.kilensprings.com/springs-production/coil/-spring-manufacturing.asp.

www.madehow.com/volume-6/springs.html

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