Review questions

REVIEW QUESTIONS

On Control Circuits

1. Make a circuit sketch for control of a double-acting hydraulic cylinder.

 [Ans. Refer Section 8.4] •

On Regenerative Circuits

2. Design and explain the working of a regenerative circuit. (or) Design the circuit to speed up the extending speed of a double-acting cylinder with suitable circuit.

[A.U., May/June 2009; Nov/Dec 2009; May/Jun 2013; Apr/May 2018] 

[Ans. Refer Section 8.5]

3. Explain the working of a hydraulic circuit used in drilling machine.

[A.U., Nov/Dec 2010] 

[Ans. Refer Section 8.6]

4. Explain with a circuit how in a shaping operation a fast approach, slow feed and rapid return can be achieved.

[A.U., Nov/Dec 2006] 

[Ans. Refer Section 8,6]

5. Explain with a circuit the technique of how a punching operation can be achieved.

[A.U., Nov/Dec 2006] 

[Ans. Refer Section 8.6]

On Pump Unloading and Counterbalance Valve Circuits

6. Design the hydraulic press circuit using unloading valve with sketch.

[A.U., May/June 2006; Apr/May 2018] 

[Ans. Refer Section 8.7] 

7. Explain a hydraulic press circuit which employs double-pump unloading principle.

[A.U., May/Jun 2013] 

[Ans. Refer Section 8.8]

8. Explain the use of counter-balance valve with a circuit.

[A.U., May/Jun 2012] 

[Ans. Refer Section 8.9]

On Sequencing Circuits

9. Design and explain the working of a sequencing circuit. (or) Two hydraulic cylinders have to work in sequence. Design a suitable circuit. Draw the circuit. (or) Explain the sequencing of two double-acting cylinders with a neat circuit.

[A.U., Apr/May 2005; Nov/Dec 2007; Apr/May 2008; May/Jun 2009] 

[Ans. Refer Section 8.10]

10. Design a hydraulic sequence circuit for a milling machine with one cylinder for operating the power vice jaw and the other for controlling the cutler travel.

[A.U., Nov/Dec 2005] 

[Ans. Refer Section 8.10] 

11. Draw a single-cylinder continuous reciprocation circuit using suitable components and give the specifications of them.

[A.U., May/June 2006] 

[Ans. Refer Section 8.11]

On Synchronizing Circuits

12. What is synchronizing? Explain the synchronizing circuit with suitable approaches. 

[A.U., May/June 2006; Nov/Dec 2006; Nov/Dec 2011] 

[Ans.. Refer Section 8.12]

13. With a neat sketch, explain how two hydraulic cylinders motion can be synchronized. 

[A.U., Nov/Dec 2005] 

[Ans. Refer Section 8.12.2]

14. With neat sketches, explain the various types of synchronising circuits.

[A.U., May/June 2006] 

[Ans. Refer Sections 8.12.1 – 8.12.3]

15. Describe an hydraulic circuit for synchronizing two cylinders with flow control valves.

[A.U., Apr/May 2008] 

[Ans. Refer Section 8.12.3]

On Fail-safe Circuits

16. Explain the fail-safe circuit with an example.

 [A.U., Nov/Dec 2009]

 [Ans. Refer Section 8.13]

17. Explain the working principle of a fail-safe circuit with overload protection.

[A.U., Apr/May 2005; Nov/Dec 2006] 

[Ans. Refer Section 8.13.2] 

18. Develop a two-handed safety circuit for the operation of a press and explain.

[A.U., May/June 2006; Nov/Dec 2006] 

[Ans. Refer Section 8.13.3]

On Speed Control Circuits

19. Draw and explain the meter-in, meter-out and bleed-off circuits.

[A.U., Nov/Dec 2016; Apr/May 2017] 

[Ans. Refer Sections 8.14.1 – 8.14.3]

On Hydropneumatic/Electrohydraulic System

20. Highlight the advantages of an air-over-oil circuit and explain it with a suitable application. 

[A.U, Nov/Dec 2006; Nov/Dec 2011] 

[Ans. Refer Section 8.17] 

21. Explain with a neat sketch, automotive power-steering application of mechanical- hydraulic servo system.

22. Explain the working of electrohydraulic servo system with neat sketch.

[A.U., Nov/Dec 2006; Nov/Dec 2016; Apr/May 2018; Nov/Dec 2018]

[Ans. Refer Section 8.20]

On Hydrostatic Transmission System

23. What is meant by hydrostatic transmission? Explain the open-circuit hydrostatic transmission system.

PROBLEM FOR PRACTICE

A double-acting cylinder is hooked up in the regenerative circuit of Fig.8.3. The relief valve setting is 100 bars. The piston area is 180 cm2 and the rod area is 60 cm2. If the pump flow is 0.0015 m3/s, find the cylinder speed and load-carrying capacity for the (i) extending stroke, and (ii) retracting stroke.

[Ans. (i) 0.246 m/s; 68.25 kN; (ii) 0.246 m/s; 68.25 kN]