Presenters: Mr. Moresh Kolhe Mr. Babu Bhondave Mahindra ... › content › dam › mathworks › ... · Mahindra & Mahindra herein referred to as M&M, and its subsidiary companies

1Copyright © 2012 Mahindra & Mahindra Ltd. All rights reserved. 1

Presenters:

Mr. Moresh KolheMr. Babu Bhondave

Mahindra & Mahindra (AFS)

2Copyright © 2012 Mahindra & Mahindra Ltd. All rights reserved.

Overview of Presentation

• Introduction.

• Objective.

• PST valve model using Simulink-Simscape.

• Results and Summary

• Summary


Introduction

• Power shuttle transmission generally used in Tractors, consists of multi-plate (wet) clutch and an additional hydraulic unit i.e. power shuttlevalve.

• The Forward/Reverse operation with Power shuttle transmissionprovides better comfort, controllability and improves productivityespecially in Loader-Dozer application..

• The power shuttle valve is operated by a F/R lever. In forward position,the pressure is built in the forward clutch whereas in reverse position,the pressure is built in the reverse clutch.

• This pressure rise in the F/R clutch makes the vehicle to make in F/Rdirection. Flow to tank line is blocked during the flow to F/R clutch.


Objective

• To study the pressure modulation and effect of variousparameters on pressure modulation of the Power shuttlevalve.

• To optimize the pressure modulation curve for shifting jerksand delay.

• To reduce the no of trials to be done on actual vehicle forthe purpose of optimization.


Power Shuttle Transmission

PST Valve

Forward Clutch engaged and

Reverse Clutch disengaged

F/R Lever

Reverse Clutch engaged and

Forward Clutch disengaged

PST Valve

Pedal pressed, Clutch disengaged

Inching Pedal

Pedal released, Clutch Engaged


PST Valve Model

• Power shuttle valve components like priority section, modulationsection, inching section etc. are modelled.

• Operator input operates the F/R and inching control.

• Mathematical model for Spring and Constraints is developed in Simulinkand for other components Simscape is used.

• Priority valve ensures a fairly constant flow rate from Pump to the F/Rvalve which also flows to modulation valve.

• F/R valve is connected to the Clutch which is engaged by the fluidpressure.

• Inching valve relieves the pressure in the clutch thereby allows inchingof the vehicle.


PST Valve Model


Results

Pressure v/s Time for F/R operation.


Results

Pressure v/s Time for Inching operation.


Conclusion

• A optimized solution for this PST is obtained, which is very close to theactual requirement.

• Using this simulation for determining modulation curve, physical testneeded for PST optimization reduced significantly.

• The results obtained from this kind of simulation provides not only basisfor evaluation of PST valve performance but also for enhancement thatcan be done in the design.

• Other issues, if simulated and verified, they can be resolved at an earlystage.

• Risk of introducing new concepts can be reduced with these kind ofvirtual validation


References

• H. Merrit, Hydraulic Control Systems, JohnWiley & Sons, INC, 1967.

• John S. Cundiff, Fluid Power Circuits and Controls (Fundamentals andApplications), CRC Press, 2001.

• Matlab-Simulink-Simscape users guide.

• Matlab-Simulink-Simscape Tutorials.

12

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Copyright © 2012 Mahindra & Mahindra Ltd. All rights reserved.

Thank you

Visit us at www.mahindra.com

Acknowledgement

I wish to express my warm thanks to Mahindra management for providing the opportunity to

work on this project. Also I would like to express my sincere gratitude to Knowledge Management

team for their support.

Documents

Presenters: Mr. Moresh Kolhe Mr. Babu Bhondave Mahindra ... › content › dam › mathworks › ... · Mahindra & Mahindra herein referred to as M&M, and its subsidiary companies