A brief report on Hydraulics And Pneumamatics Experiments, conducted at BOSCH - REXROTH centre at gulbarga

1. HYDRAULIC AND
PNEUMATIC EXPERIMENTS
– A REPORT
CONDUCTED AT BOSCH HYDRAULIC AND PNEUMATIC
CENTRE
GULBARGA
DEPARTMENT OF MECHANICAL ENGINEERING
SUBMITTED ON
5/6/2017
Submitted by,
Vidyasagar Ghantoji
6th sem ‘A’ section
Roll No. 06
Vtu no. : 3PD13ME093
THIS IS THE BRIEF REPORT ON THE EXPERIMENTS THAT ARE CARRIED OUT AT THE HYDRAULICS
AND PNEUMATICS LABROTARY OF BOSCH CENTRE KALABURAGI. THE EXPERIMENTS LEARNT ARE
BRIEFED HERE IN THIS REPORT.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
INDEX
TOPIC Page
no.
Remarks
 Structure of a pnematic system 4
 Direct control of a single acting cylinder 5
 Indirect control of a single acting cylinder 6
 Direct control of a double acting cylinder 8
 Speed control of a single acting cylinder 9
 Quick exhaust valve 11
 Circuit using a Roller Valve 13

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Poojya Doddappa Appa College Of Engineering, Gulbarga
Acknowledgement
I would like to express my gratitude in completing this report and performing the
experiments successfully and the efforts in teaching by my beloved lecturer Mr.
R. M. Latthe
Prof. R. M. Latthe has been a very great inspiration under whose guidance I have
been able to learn and understand and complete the experiments in the
BOSCH- REXROTH laboratory which is one of its kind in this North Karnataka.
Without his perseverance we wouldn’t have had any hands on experience of
handling and learning on this machines and circuits.
Because of the efforts of Prof. R. M. Latthe students of this area will be benefitted
All along prof. R.M. Latthe has been with me in successfully completing
He is definitely one of his kind!

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Poojya Doddappa Appa College Of Engineering, Gulbarga
The above flow chart shows the structure of a pneumatic system

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Poojya Doddappa Appa College Of Engineering, Gulbarga
1. DIRECT CONTROL OF A SINGLE ACTING CYLINDER.
Fig: Direct control of single acting cylinder.
This is the circuit in the figure which shows the direct control of a single acting
cylinder which is used to control the actuator using the 3/2 DCV which is a spring
retracted valve and even has a push button. Where the working fluid ( i.e. air over
here) is sent directly to the single acting cylinder and the actuator moves.
Here for the extension the flow of the working fluid is done from 1 to 2 port of
the DCV, for retraction the port 2 is directly connected to the exhaust port

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Poojya Doddappa Appa College Of Engineering, Gulbarga
2. INDIRECT CONTROL OF A SINGLE ACTING CYLINDER.
Fig:Indirect control of single acting cylinder

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Poojya Doddappa Appa College Of Engineering, Gulbarga
This is the circuit which shows that a cylinder is being controlled by a 3/2
DCV where there is a push button and a spring retracted type and the other is
operated using piolet and spring operated type. As the name suggests this is the
indirect acting single acting control system where the working fluid (i.e., air here)
is sent to the cylinder or the actuator indirectly via the push button and the DCV
and hence the work is completed
Generally, in the industrial applications the indirect type of single acting
cylinder is preferred so as to maintain the safety precaution aspects as the pressure
in the industrial applications exceed to 6 bar. For extension the flow of the air is
from 1 to 2 ports of the DCV which is being operated using push button for which
it sends the signal to the DCV to get the extension of the actuator. For the
retraction process the port 2 of the DCV which is piolet operated is directly
connected to the exhaust port and hence the work is safely done.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
3. DIRECT CONTROL OF A DOUBLE ACTING CYLINDER.
Fig: Direct control of a double acting cylinder.
This is the circuit which shows the double acting cylinder
which is being controlled by the action of 5/2 control valve. This 5/2 control
valve is a spring balanced as shown above. In the direct acting control valve of a
double acting cylinder the working fluid (i.e., air here) is directly sent to the
cylinder and the cylinder is actuated.
For extension the flow is taking place from the port 1 to port 2
of the DCV as shown above in the circuit where the exhaust air is being ejected
from the rod end of the cylinder from port 4 to pot 5. The retraction part is done
by port 1 to pot 4 as the working fluid is sent by the DCV to the piston end of
the cylinder the excess air from the piston end is removed by the port 2 to port 3
as it is directly being released to the atmosphere

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Poojya Doddappa Appa College Of Engineering, Gulbarga
4. SPEED CONTROL OF A SINGLE ACTING CYLINDER.
Fig: Speed control of double acting cylinder.
The above circuit shows the speed conrtol of the double acting cylinder
where thespped of the cylinder can be controlled using a fow conrol valve in the
circuit, when this flow control valve is introduced in the circuit it just controls the
flow of the working fluid with the help of a valve which and when can be adjusted
according to our requirements and needs. This even help to maintain the proper
functioning of the whole system and thus by not harming the personnel working
near it.
There are 2 types of the speed control system
 Meter IN
 Meter OUT

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Poojya Doddappa Appa College Of Engineering, Gulbarga
The above circuit shows a Meter OUT system where in the
cyclinder is maintained at the definite movement of the cylinder. For the
extension of the cylinder the flow of the working fluid is taking place from the
port 1 to port 2 of the Direction control valve and the excess air present is removed
from the rod end of the actuator/ cylinder.
The double acting cylinder is controlled by the action of one 5/2
valve which is spring balanced and push button operated as shown in the figure.
This is the speed control of the double acting cylinder where the speed of the
cylinder is to be maintained for the proper functioning of the system to do a
particular work.For extension the flow of the working fluid is from port 1 to port
2 of the DCV and the extension of the actuator takes place thus by ejecting the
air present in the rod end of the cylinder from ports 4 and 5, the air which is
ejected will be passing through the check valve and the throttle valve and then
flow to the orifice which can control the speed of the air thus by controlling the
speed of the cylinder too. Hence for the retraction of the cylinder the flow of the
working fluid is from the ports 1 to 4 and the flow is directly from the ports which
doesn’t turn up with the orifice and hence the piston is moved from the position
2 to 3 and the excess air from the rod end of the cylinder is exhausted from the
outlet to the atmosphere.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
5. USE OF QUICK EXHAUST VALVE TO THE SYSTEM (ANY).
Fig: Quick exhaut valve single cylinder (left) double cylinder circuit (right)
The above type of circuit shows the usage of the quick exhaust
valve where in the valve is fixed at the exhaust side of the woking fluid ( i.e., air
here) the quick return motion of the cylinder shall get some productive time so as
to contuine the next cycle of the work. The quick exhaust vlave is designed in
such a way that the cross section area is greater than the normal exhaust valve so
as to expel out much amount of the working fluid from the cylinder to continue
the work this valve allows the exhaust air directly to the atmosphere with a certain
amount of greater force than that of the normal exhaust valves.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
The main component of quick exhaust valve is a silencer which
tends to reduce lot much amount if noise created while the working fluid is
expelled but however, there is a ‘Pop’ sound which is caused while the expelling
of the fluid which is not inevitable but a silencer reduces the noise for a greater
extent. The below photo shows a quick exhaust valve with a silencer
Fig: Quick exhaut valve with silencer.
Fig: A Muffler / Silencer
The above photo shows a muffler / silencer which reduces the noise of the air which comes
out to a greater extent. This is a brass type of adustable muffler/ silencer.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
6. AUTOMATIC RETURN OF THE DOUBLE ACTING CYLINDER USING
ROLLER VALVE.
Fig: Roller valve for the double acting cylinder
.
Fig: Circuit of double acting cylinder with roller valve.

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Poojya Doddappa Appa College Of Engineering, Gulbarga
The above circuit shows the system which uses the roller valve in
series connected in the path of the cylinder. As the cylinder end touches the roller
the roller at once send the signal to the piolet operated DCV and hence the
retraction takes place at once. This type of valve is very helpful in setting up the
distance of the cylinder and confine that distance to a certain extent. This doesn’t
need any of the switch nor push button to retract due to the presence of the roller
valve.
This type of element is connected so as to adjust the distance to be
travlled by the piston from the cylinder in the circuit.
Figure shows the complete view of the roller valve used in the circuit.