Anna University Model Question Paper BE VI sem Mechanical HYDRAULIC AND PNEUMATIC CONTROLS






TIME – 3 Hours                                                                    MAXIMUM : 100 Marks




   PART – A                     (10 x 2 = 20 Marks)


  1. What do you mean by cushioning of Fluid power actuators?.
  2. A double acting cylinder is hooked up in the regenerative circuit.

     The relief valve setting is 68.94 bar and the Piston area

      is 6.35 x 10-3m2 & the rod area is 1.778 x 10-3 m2. If the pump

      flow is 75.706 lpm find the cylinder speed for retracting stroke

  1. List out the four types of fire resistant hydraulic fluids?
  2. What is F-R-L and what is the function of a lubricator?
  3. State the functions of accumulator in hydraulic Circuits?
  4. Draw the symbol for a relief value and pressure reducing value.

      7.  List out the basic types of filtering methods used in hydraulic systems.

8.   List out the most widely used types of seal configurations.

9.   What is a Pneumatic Vacuum System?

    10.  What is the use of ladder diagram?


PART B                             (5 x 16 = 80 Marks)


11(a) (i) .For the Hydraulic system shown below, the following data are given

        The pump is adding 3.68 kW of power to the fluid.

         Pump flow is 0.001896m3/sec

         The pipe has a 0.0254m inside diameter.

         The specific gravity of oil is 0.9

         The kinematic viscosity of oil is 100mm2/sec

         The elevation difference between stations 1 and 2 is 6.096m

         Pipe lengths are as follows:0. 305m, 1.22m, 4.88m. 



Find the pressure available at the inlet to the Hydraulic motor

(Station2). The tank top surface of the hydraulic tank is exposed

 to atmosphere. The head loss due to friction between station1

and 2 is not known?                                                                      (8 Marks)

(ii) Explain with neat diagrams closed loop (servo) electro hydraulic

     control system and open loop hydraulic system                        (8 Marks)


 12. (a) (i) Explain the working of an unbalanced fixed displacement

                 vane pump with a neat sketch.                                               (8 Marks)

            (ii) Explain the working of an axial piston pump of bent – axis

                 type with neat sketch.                                                               (8 Marks)

( OR )

 (b) (i). Draw and explain constructional features of a 5/3-direction

            control valve of linear type along with its graphical symbol.    (8 Marks)

(ii). With neat sketch explain the operations of a pressure-

      reducing valve. Sketch its graphical symbol                            (8 Marks)


  1. (a) With the help of circuits, explain how synchronizing of two

           linear actuators are achieved by connecting them in series

           and in parallel                                                                                 (16 Marks)

( OR )


      (b)(i). Construct a hydraulic circuit to explain the application of regenerative system in a drilling machine.                         (8 Marks)

                 (ii) Construct a double pump hydraulic circuit employed

                      in a punching press and explain how it functions.              (8 Marks)


14) a.(i) Design a fluidic box sorting system for two different sized

              boxes moving on a conveyor by making use of the

              preferenced  flip flop ,DCV and Push buttons.                        (8 Marks)

(ii) Design a fluidic sequencing control of two pneumatic cylinders

     using flip-flop, OR Gate, Push buttons, Directional control valves

     etc for the following sequence;

           Cylinder 1 extends

           Cylinder 2 extends

           Both cylinders retract together.                                           (8 Marks)

( OR )

.        (b) (i) Briefly explain the various electrical devices used in the

                   control of Fluid Power systems.                                                (9 Marks)

             (iI) Design and explain Electro pneumatic circuit for automobile reciprocation of a Double acting cylinder using pressure

                   switches.                                                                              (9 Marks)                                                    

15 (a).(i) What is PLC? Explain the elements of PLC with

              block diagram.                                                                             (12 Marks)

   (ii). Write down the advantage of PLC over electro mechanical

         relays system.                                                                       (4 Marks)

( OR )

       (b). Design and explain a sequential circuit using cascade method

              for the following sequence.                                                    (16 Marks)

                              A + B + A  B           



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