Mechatronic Modeling: Pretensioner Mechanism Simulation Analysis as part of a Retractor Mechanism.

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Mechatronic Modeling Pretensioner Mechanism
Simulation Analysis as part of a Retractor
Mechanism.

• 04/19/2006
• Guillermo Cazares

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Presentation Content

• Background Information
• Functional Analysis
• Simulation Analysis
• Results
• Conclusion

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Problem Statement

• Analyze the performance of Pretensioner Mechanism
  as part of a retractor assembly in a seat belt
  system.
• Transfer of Pressure over the piston.
• Transfer of torque to belt and determine the
  length of belt.
• Note The requirement is that 80mm of belt must
  be pulled into spool in 12ms.
• (Beside packaging and weight requirements)

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Background Information

• Components of a Seatbelt System

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Background Information
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Background Information
Belt
Locking Mechanism
Pretensioner Unit
Retractor Assembly
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Background Information
Damper
Tube
Assembly Vent
Piston
Shaft
Spring
O-Ring
Gearwheel
Cover
Pinion
Housing
Hub
Roller
Gas generator
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Background Information
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Schematic Diagram
Signal From CU
Igniter Fires Propeller Pressurizes the Chamber
Piston Movement
Pinion Gear Wheel Rotates
Hub Rotates
Rollers Engage Hub to rotate Spool
Spool Pulls In Webbing
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Bond Graph
Transformer 1 Hydraulic Power to Mechanical
Translation Power
Transformer 2 Mechanical Translation Power to
Mechanical Rotational Power
Transformer 3 Mechanical Rotational Power.
Transformer 4 Mechanical Rotational Power.
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Results
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Comparison Results
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Results
Force at the Piston
Speed of Piston
Torque at the Spool
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Further Simulation
Radius of 25 mm
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Conclusion

• The simulation used did give us the expected
  results expect that I had to remove some of the
  unknown R and C elements that in reality are
  present in the system.
• At the same time the model provided useful
  information that is very difficult and costly to
  attain.
• It allows you to gain knowledge of the behavior
  of a system with simple click of a button.

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Questions?

• Thank you for your Attention