© August 2018 | IJIRT | Volume 5 Issue 3 | ISSN: 2349-6002

Design and Analysis of Brake master cylinder for an ATV

Mr. Shantanu Chavan1 , Mr. Vishal Tile 2 , Mr. Mohit Chavhan3 , Mr. Shubham Agnihotri4
1, 2, 3, 4
Student, Mechanical Engineering, MIT Pune

Abstract- Braking system is a means of converting In the initial position when the brake pedal is not
momentum into heat energy by creating friction in the pressed, the position of piston can be seen as follows:
wheel brakes. The braking system which works with the The ports of the master cylinder are open in the initial
help of hydraulic principles is known as hydraul ic
position.
braking systems. The most frequently used system
When the pedal is pressed, the piston moves forward
operates hydraulically, by pressure applied through a
liquid. These are the foot operated brakes that the against the spring force. The piston cup seals the
driver normally uses to slow or stop the car. Our special compensating port. This prevents the entry of more
interest in hydraulics is related to the actions in fluid into the front section. Thus pressure starts to
automotive systems that result from pressure applied to build up. This pressure is carried by the fluid lines to
a liquid. This is called hydraulic pressure. S ince liquid the brake caliper. When the pedal is released again,
is not compressible, it can transmit motion. A typical the piston returns to its original position. However,
braking system includes two basic parts. These are the the fluid does not return to its original position at the
master cylinder with brake pedal and the wheel brake
same time. Thus, a low pressure region is developed.
mechanism. The other parts are the connecting tubing,
This is the reason why small holes are provided in the
or brake lines, and the supporting arrangements. The
present paper is about designing of Twin master piston seat and also conical nature of piston cup.
cylinder system for and all-terrain vehicle and doing a Fluid from the reservoirs enters through the inlet
feasibility study of its strength using ANS YS . Our work ports. It flows through the holes on the piston side to
is focused on reducing weight which is one of the factors the low pressure area.
to increase the efficiency. Reduction in weight and When the pressure becomes equal, the excess fluid is
space, due to its compactness. The twin Master cylinder returned back to the reservoir via the compensating
system is a great advancement in braking system for an port.
ATV. 3-D CAD modelling is done using
III. CALCULATIONS
S OLIDWORKS 2017, whereas the analysis of its
strength is done using ANS YS .
Important Parameters:
Index Terms- Hydraulic system, brake, master cylinder, Pedal Force applied by driver (FP) = 250 N
analysis, design, twin master cylinder Pedal Leverage = 4.5
Wheel Torque (Tc) = 161 Nm
1. INTRODUCTION Brake caliper piston diameter (Dc) = 32 mm
Maximum piston travel of caliper (Lc) = 1.5mm
Twin master cylinder set-up: Radius of disc (R) = 190 mm
It consists of two master cylinders each having Assumptions:
separate hydraulic circuits in Front rear split. One Deceleration = 0.8g
master cylinder provides hydraulic pressure for the Coefficient of friction between tire and ground = 0.78
front brakes while the other provides pressure for the Coefficient of friction between pads and disc = 0.35
rear. Master cylinders are actuated by bias bar Dynamic weight transfer = 75.66 kg
through pedals. The force provided by the driver is Piston Diameter Calculations:
divided according to the necessity required to satisfy FM = Force on master cylinder
the torque required at each wheels.
FC = Force on caliper
II. WORKING

IJIRT 147001 INTERNATIONAL JO URNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 38

 © August 2018 | IJIRT | Volume 5 Issue 3 | ISSN: 2349-6002

A C = Area of caliper piston This part helps in retraction of piston when the pedal
( ) is released. As soon as pedal is released, the piston
comes back to its original position.
P = Pressure in the system Material: ASTM A 228

A M = Area of Piston

Fig.3: Spring
M = Master cylinder bore diameter Copper Washer:
This part is placed between the piston surface and the
√ seal. It is used for unidirectional flow of fluid during
retraction.
Stroke Length Calculations: Material: Copper
V = Volume displaced by caliper piston

LM = Stroke length of master cylinder Fig.4: Copper Washer

Piston Cup:
This part provides the sealing and holds the generated
pressure until the pedal is released.
IV. CAD MODELLING Material: EPDM

3-D CAD modelling is done in SOLIDWORKS 2017

software. Topological optimization was done by
making several iterations of components by
comparing its strength, weight and feasibility. Final Fig.5: Piston Cup
design of components are shown below: Push rod:
This part, as the name suggests, is used to push the
Casing: piston when the pedal is pressed.
This part houses the piston, piston cups, washer and Material: Mild Steel
spring. It is designed so as to bear the pressure
generated by the piston arrangement.
Material: Aluminium 7075-T6

Fig.6: Push rod

Push rod adjuster:
This part connects the push rod to the pedal.
Material: Mild Steel
Fig.1: Casing
Piston:
This part slides in the casing to produce the pressure.
Material: Aluminium 7075-T6

Fig.2: Piston Fig.7: Push rod adjuster

Spring:

IJIRT 147001 INTERNATIONAL JO URNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 39

 © August 2018 | IJIRT | Volume 5 Issue 3 | ISSN: 2349-6002

Exploded view of master cylinder: mesh density where curvature is small or edges are
closed in proximity.
Material used is Al 6061 with Syt=350 Mpa,
Poisson’s ratio=0.33 and Density=2700 kg/m3.
The boundary conditions applied are pressure
generated in cylinder casing and the axial force
applied through the push rod. The casing is fixed at
the mounting points. For the braking system consider
which is for an ATV the applied braking force is
assumed to be 350 N. The force is magnify by the
Fig.8: Master cylinder exploded view
leverage of 4.5 provided by the pedal assembly and
1575 N force is applied by the push rod. Also the
Assembled view of master cylinder:
maximum pressure generated in system is applied on
inner surfaces of casing.
The results of maximum stress and deformation
shows that the master cylinder is safe for designed
shell and mounting thickness.

Fig.9: Master cylinder assembled view

V. FINITE ELEMENT ANALYSIS

Finite Element Analysis is a practical application of

Finite Element Method (FEM). FEM is a numerical (a) Casing (b) Cut section
technique for finding approximate solutions to Fig.10: FEA Model
boundary value problems for partial differential
equations. It uses subdivision of a whole problem Maximum Stress (Cylinder casing) = 177.6 Mpa
domain into simpler parts, called finite elements, and Maximum Deformation (Cylinder casing) = 0.02 mm
variational methods from the calculus of variations to Maximum Stress (Piston) = 138.52 Mpa
solve the problem by minimizing an associated error Maximum Deformation (Piston) = 0.0108 mm
function. Analogous to the idea that connecting many
tiny straight lines can approximate a larger circle, VI. CONCLUSION
FEM encompasses methods for connecting many
simple element equations over many small The model was proposed using design oriented
subdomains, named finite elements, to approximate a calculations. On the basis of study on modelling and
more complex equation over a larger domain. analysis technology using ANSYS, the FEA of
A simple structural analysis was performed as the master cylinder was realized. The stress and
first step to see if components were structurally deformation of the model were under control.
strong. If a component failed with the loadings, then
no need to continue stress or fatigue analysis since REFERENCES
the component is not strong enough to be used. The
analysis of the various components of the master [1] C.J.Buynacek and W.L.Winterbottom,
cylinder was done in ANSYS 16.0 WORKBENCH Aluminium master cylinders.
for meshing as well as solving. [2] Melior, Inc., Introduction to Brake Systems –
Meshing of all the parts was done in ANSYS. The Study guide. LEXUS Technical training, Master
mesh is generated by using tetrahedron elements of 1 cylinder.
mm size. Mesh quality is further improved by using [3] Thomas D. Gillespie.” Fundamentals of Vehicle
proximity and curvature function. This improves Dynamics.”

IJIRT 147001 INTERNATIONAL JO URNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 40

 © August 2018 | IJIRT | Volume 5 Issue 3 | ISSN: 2349-6002

[4] Walter W. Wright and Michael Hallden-

Abberton "Polyimides" in Ullmann's
Encyclopedia of Industrial Chemistry, 2002,
Wiley-VCH, Weinheim.
[5] Limpert Rudolf, “Brake Design and Safety,
society of automotive engineers, Warrandale,
Inc, Second Edition, USA, 1992, PP 11- 157.

IJIRT 147001 INTERNATIONAL JO URNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 41