INFLUENCES OF BRAKE SHOE THICKNESS AGAINTS DISC BRAKE VIBRATION SYSTEM ON Influences Of Brake Pad Thickness Againts Disc Brake System Vibration On Various Braking Condition.

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INFLUENCES OF BRAKE SHOE THICKNESS

AGAINTS DISC BRAKE VIBRATION SYSTEM ON

VARIOUS BRAKING CONDITION

PUBLICATION ARTICLE

Submitted as a Partial Fulfillment of the Requirements for GettingBachelor Degree of Engineering in Automotive Department

Arranged by :

Dwi Aji Saputra

NIM : D 200 102 012

MECHANICAL ENGINEERING PROGRAM STUDY

ENGINEERING FACULTY

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INFLUENCES OF BRAKE SHOE THICKNESS AGAINTS DISC BRAKE VIBRATION SYSTEM ON VARIOUS BRAKING CONDITION

Dwi Aji Saputra

Automotive Department of Muhammadiyah University of Surakarta Jln. A. Yani Pabelan-Kartasura. Tromol Pos I Telp. (0271) 715448 Kartasura

Email: Dasfotograph@yahoo.co.id

ABSTRACT

Abstract :

The aim of this study is to determine the condition of the brake vibration and analyze the

parameters that affect the vibration response occurring. Test was carried out by varying the

thickness of the brake lining. Data taken for thickness of the brake lining (7,5 and 3)mm, with

a variation of the braking pressure 0.6bar and 1bar, shaftrotation (425, 637, 850, and

1061)rpm, the axial and radial direction, vibration measurement used Lutron VB_8202

vibration meter.

Vibration on acceleration measurements show that vibration acceleration in the

radial direction which seems higher when compared to the axial direction, can be in the know

in the axial direction 425 RPM vibration acceleration value is not more than 8.2m / s while the

radial direction up to 11.6m/s .

Increasing the value of amplitude 2-4.7 m/s2_{in dictateLessing of Brake pad}

worn.The increase in vibration owing to the reduced value of brake lining.

Keywords :Brake, Brake lining thickness, Brake pressure, Damping.

Background

Brakes are an important component

of motor vehicle. Brake function is to

stopping or slowing down. In general, the

vehicle uses hydraulic brake system. The

Components of hydraulic brake are master

cylinder and caliper (cylinder body).

Cylinder Master distributes a braking

pressure from the pedal tocalipers (cylinder

body) through the brake hose. The

caliper (cylinder body) is usedto forward a

hydraulic pressure to brake pad.

Brake works by using

pressureprinciple to slow down the rotation

so that it reveals a friction between the

discs (disc brake) with brake pads. These

friction causes vibration, heat and

noise. Disc roughness and friction

factorstringer the vibration of brake pad and

caliper.

Vibration in the brake components

during operation can cause noise. It comes

from the friction between brake pads that

have been worn by the disc brakes. One of

factors which cause the vibration when

braking operation is worn thin brake

pad. The effects of excessive vibration will

cause inconvenience driving. In addition,

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the performance or the operation of the

braking was not optimal.

Brake pad is so extremely important

when braking. It needs special attention to

the condition of the brake pad. Therefore,

there should be a study to determine the

effect of thebrake pads thickness against

the brake disc vibration in the system.

PROBLEM LIMITATION

From above explanation, it can be

taken a problem formulations, namely: how

to influence the thickness of the brake pads

on a range of braking conditions on the

vibration of the disc brake system.

OBJECTIVE

The purpose of this study is

determining the effect of the brake lining

thickness at various braking conditions on

the vibration disc brake system in the form

of changes in the value of the vibration

amplitude.

FORMULATION

To determine the direction of research,

given the extent of the problem as follows:

a. All components of the braking device

is assumed to be at normal

conditions (80% for the master,

calipers, discs and brake hoses).

b. Load conditions are considered

constant.

c. Data Display is only in the form of

vibration amplitude value.

d. At the same braking pressure, the

frictional force is assumed to be the

same for all variations in the

thickness of the brake lining.

The friction coefficient is assumed to be

the same on this test.

LITERATURE REVIEW

Oura (2009), conducted a research on

the mechanism of the appearance of disc

brake squeal vibration.

Carried out research on testing squeal

vibration using Pads with different

thicknesses. The experiment was done with

testing equipment squeal by using brake

pieces with size 20x20 mm with a thickness

variation of the brake lining as testing

material.The experiment was conducted

with dynamic stiffness test apparatus which

was providing a constant pressure. The test

results showed the dynamic stiffness of

Pads became stiff when braking pressure

was increasing, and the stiffness increased

with the thin Pads. Results of the testing

showed the frequency squeal was high

when the stiffness of Pads became hard.

BASIC THEORY

A. Brake Work System

In general, the brake discs are currently

working to apply the principles of

hydraulics. The hydraulic system consists

of a master cylinder, brake calipers, brake

oil reservoir to place and other supporting

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on brake master so piston inside brake

master push fluid brake to fluid path, and

then entering to piston chamber brake

caliper. At Outer Piston, brake pad is

installed, this brake pad clamps disc brake

by using piston pressure to outer direction

which is caused by the pressure of brake

fluid so that the friction effect among dsisc

and brake pad are generated braking

process. Frictional forces that occur in the

disc braking system can be explained in the

following figure:

Figure 1. How Disc Brakes Work

(Anonim, 2012)

B. Disc Brake Components

In general, disc brake components

are as follows:

a. Brake Pad

Brake consists of a mixture of fiber and

little metallic iron powder. Generally brake

pad is given lining brake to show the thicks

of brake pad.Thus, the worn of the brake

can be checked easierwhen unloading

brake components. In some brake pads,

the use of metallic plate attached to the

side of the brake piston whose function is to

prevent noise when braking.

Brake is also a major component of the

brake as it serves as a grappling discs so

that the rate of the vehicle can be reduced

and eventually stopped completely, usually

made of composite materials or pasta.

Brake commonly used in today's modern

vehicles is appropriate types of brakes,

whether wearing drum brake or disc brake.

To canvass brake used in generally disc

brake pad or brake disc called a pad, while

used on drum brakes are often called brake

shoe.

Figure 2. Brake Pad

b. Disc

In general, disc brake or disc made of

cast iron and holes for ventilation and

cooling function. Given the age of the brake

ventilation and longer lasting.

Figure 4. Disc

c. Caliper

Caliper is also called a cylinder body,

which functions holds-piston and the

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the brake master cylinder of the caliper.

The components contained in the circuit

calipers as follows:

1. Piston

2. Piston Ring

3. Rubber Protector

4. Torque plate

The cause of the vibration on the brake disc (brake pad)

1. Disk disc is not smooth 2. Disc Thickness

3. Unbalance disc

4. Worn disc Brake and Brake pad 5. Dust and dirt.

Brake force this optained from the

friction between Brake pad and disc.

Vibration happens on the brake during

operation is vibration excited or self-excited

vibration where the system generates a

number of excitation that produces

oscillatory motion in the system itself.

Numbers fnis one of the most important in

the amount of vibration analysis and is

called the natural frequency. With the

equation to find the natural frequency of the

brake lining is:

/

With a record of angular frequency ω, with

units of radians per second, often used in

equations because it simplifies the

equations, but the amount is usually

converted into a frequency "standard"

(units of Hz) when stating the frequency of

the system.

Vibration

Vibration is a back and forth motion

within a certain interval. Vibration

associated with the oscillatory motion of

objects and force associated with these

objects. All objects that have mass and

elasticity is able to vibrate, so most

machines and structural engineering

(engineering) experience some degree of

vibration and design requires

consideration of the nature of the

oscillation.

2

The magnitude of we can see the

equation:

2

Displacement deviation can write

as:

Harmonic motion velocity and acceleration

can be obtained by differentiation of

equation by using dot notation for

derivatives, then ;

a. Free Vibration without damping

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k

x(t)

F

Figure 2.7. Vibration without dampers

b. Free Vibration with Dampig

Where :

/

k c

x(t)

Figure 2.8 Vibration with damping

Factors affecting the value of the vibration on the brake

a. Stiffness

Stiffness of the structure is an

essential. Restrictions are useful for

maintaining the rigidity of construction so

as not sagged more than the required

deflection. Stiffness is defined as the force

required to obtain one unit of

displacement. Stiffness value is the slope

angle of the relationship between load and

deflection. The more rigid a structure

greater rigidity values.

b. Friction force

Friction is the force that is generated

by two objects rub against each other and

the direction opposite to the motion of

objects. Here is the friction on the beam.

With the equation to calculate the friction

force is:

Fg = .N

Figure 2.11 Friction on the beam

c. Damping

Damping is the absorption of incident

energy (energy dissipation) by a structure

due to various reasons. Some of the

causes include the release of energy by

movement between molecules within the

material, the release of energy by friction

linking devices and systems support, the

release of energy by friction in the air. The

energy release is also the result of plastic

joints. Since the damping function of

energy release then this will reduce the

structural response.

Therefore greatly affect the vibration

damping. Where the damping is strongly m

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influenced by the critical damping value

(critical damping), the point at which the

system no longer oscillates. The amount of

attenuation is usually expressed in damping

ratio. The coefficient of damping required to

reach the point of critical damping is:

2 2√ 2

If the value of the damping coefficient to

reach the point of critical damping, then the

system will be difficult muffled. So it is

difficult to stop oscillating system,

consequently a large vibration.

∆ _··

· ∆

·

F F

c

Page 2.12 Deflection axial

Where : ∆

/

...

RESEARCH METHODOLOGY

Flow chart diagram

Material and Tools

Tools wich used in this research are as

follows :

a. Brake pad vibration test equipment (with electric motor 3 phase 5,5 HP) b. 3 couple Brake pad with different

thickness (7mm, 5mm, 3mm). c. Piezoelectric Accelerometer.

d. Vibration meter markLutronVB_8202 e. Tachometer.

f. Inverter. g. Pulley dan bel

MAKING OF DATA

Thickness Variation (A = 7, B = 5, C = 3) mm Braking Pressure Variation (0,6, and 1) Bar Variations Rpm (425, 637, 850 and 1061)

START

Making tool vibrations test disc thickness brake Pad

Acceleration value of data vibrations

Analysis

Conclusion

END

k

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Af

re 9.Test da

ibration met

Acceleromete

Brake Pad

is complete

d the data

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ata making s er

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assembled

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he first ste

with recor

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he excel pro

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and also br

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raking press

f the motor.

uency of the

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calculate t

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a processin

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ation data in

program. W

a graph whic

brake linin

tation of th

sure variatio

Measureme

e system eac

tion with th

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8.9

425 637 850 1061

RMS

Vibration Graphs on axial direction for pressure 1 bar

Pad 7

Pad 5

Pad 3

RPM Data And Analysis

Then, the data above are analized to

knowing the vibration at different brake

pressure and shaft rotation speed. Data

measurment shown at following figure :

Rotation (RPM)

Vibration Velocity (m/s²) Thickness

Figure 10. Relationship between the

rotation axes of the vibration amplitude in

the axial direction, the braking pressure of

0.6bar

Figure 11. Relationship between the axis

rotations of the vibration amplitude in the

axial direction, the braking pressure of 1bar

425 637 850 1061

RMS V

A

LUE

(m/s

2)

Vibration Graphs on axial direction for pressure 0.6 bar

Pad 7

425 637 850 1061

RMS

Vibration Graphs on Radial direction for pressure 0.6 bar

Pad 7

Pad 5

Pad 3

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Figure 12. The relationship between the

rotation axis of the vibration amplitude in

the radial direction at a pressure of 0.6bar

Rotation

(RPM)

Vibration velocity (m/s²)

Thickness

Figure 13. Relationship between the axis

rotations of the vibration amplitude in the

radial direction at a pressure of 1bar

Discussion

The results of processing the vibration

acceleration values indicate that an

increase in the value of the acceleration of

vibration generated each variation of the

thickness of the brake lining. This increase

is indicated by the value of the acceleration

of vibration that occurs in brake that has

experienced wear and worn. The results of

the processing vibration indication that the

brake pads are still good or still thick

produces low vibration acceleration value.

From vibration value measurment, we

can find the value of brake pad natural

frequency and critical damping coeficient

which will get result as table below:

Table 1. Values of natural frequencies and

critical damping coefficient value of each

brake pad.

Thick Brake

Pad (mm) (Hz) (Ns/m)

7 493,63 184,61

5 1111,94 373,27

3 4447,92 1352,16

Based on the results of these calculations

with a critical damping coefficient is greater,

and the system will easily vibrate because

of small damping ratio.

On the axial direction of the

measurement pressure of 1 bar (Figure 4.2)

and the measurement of radial pressure of

1 bar (Figure 4.4) it can be seen that the

thickness of the lining 5mm shaft speed

637 rpm surge approaching the vibration

amplitude values even exceed the value of

the amplitude of vibration in the lining

thickness of 3mm.On the measurement of

vibration velocity shows that the vibration of

velocity in the radial direction which

appears larger when compared to the axial

direction, as shown in the graph measuring

the axial direction for the braking pressure

0.6 bar (Figure 10) and radial graphs for

9.6

425 637 850 1061

RMS

Vibration Graphs on Radial direction for pressure 1 bar

Pad 7

Pad 5

Pad 3

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braking pressure 0.6 bar (Figure 12) it can

be seen the difference value of the

resonance. 425 rpm for shaft rotation in the

direction of axial value does not exceed 8.2

m/s2, while in the radial direction vibration

reaches the value of 11.6 m/s2. This occurs

due to the effect of centrifugal force on the

rotation axis to the radial direction, so that

the force that occurs on the radial direction

is greater than the axial direction.

Conclusion

From data analysing and discusion can be

of tained conclusion as follow :

1. Increasing the value of aplitude2-4,7

m/s2in dicate lessing of Brake pad

worn.The increasing of aplitude value is

cause by the lessing of pad mass, that

affect the decreasing of damping value

to vibration, then Increasing of braking

pressure and shaft rotation will increase

exitation force that cause the value of

amplitude greater.

Sugesstion

1. Next, we can do research to detect the

level of brake pad worn using other

brand.

2. Before take the data, it is better to know

the brake resonansi frequency.

Sugegestion

Untuk selanjutnya dapat di lakukan

penelitian untuk mendeteksi tingkat

keasuan kampas rem cakram

dengan bahan atau merk yang

berbeda.

Sebelum pengambilan data

henaknya mengetahui frekuensi

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