Browse Prior Art Database

Diesel Dual Mass Flywheels with Solenoid assisted, centrifugal Locking Toggles

IP.com Disclosure Number: IPCOM000032846D
Publication Date: 2004-Nov-15
Document File: 2 page(s) / 13K

Publishing Venue

The IP.com Prior Art Database

Abstract

A Dual Mass Flywheel is equipped with 3 equispaced spring assisted Bob weights or Toggles to lock the Dual Masses (DM) at cranking or low engine RPM's. These toggles, positioned on the DMF periphery allow a Bell housing ECU controlled solenoid to assist by magnetic field and control the locking action over a small rpm range. Importantly excitation or stall conditions are pre empted by logging engine rpm decay rates and then locking the DM's earlier & releasing accordingly.

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 52% of the total text.

Diesel Dual Mass Flywheels with Solenoid assisted, centrifugal Locking Toggles.

Modern vehicles have mandatory fuel economy declarations. Wind tunnel optimised bodies create low wind noise which now make other noise sources perceptible. Lighter more powerful engines with multispeed, high geared manual trans-missions mean higher engine loads at lower speeds and with thinner oils. The resultant torsional vibrations all react to expose inadequate natural damping and result in transmission gear rattle & body noise.

Dual Mass Flywheels (DMF) work by dividing their mass into 2 parts (primary engine side and secondary transmission or driven side) and they have been developed to move the offending speed resonance lower below the normal engine operating range. This is achieved (in most cases) by connecting the 2 masses via a radial spring damping system supported by a ball bearing to allow controlled, 20-30 Deg relative rotation providing worthy improvements in refinement.

The shortfall of DMF's is their ability to self excite at lower than normal engine speeds which are inadvertently encountered in normal day driving.  These momentary excursions, especially on higher torsional vibration 4 cyl Diesels, (i.e. a 500rpm clutch/manoeuvre situation) are sufficient for DM self excitation which can then help the engine to stall or run roughly. In worst cases, excitation can lead to destructive DMF damage,

METHOD -Principles & Detail:

 

Principle: The DMF is equipped with 3 equispaced spring assisted Bob weights or Toggles to lock the Dual Masses (DM) at cranking or low engine RPM's. These toggles, positioned on the DMF periphery allow a Bell housing ECU controlled solenoid to assist by magnetic field and control the locking action over a small rpm range. Importantly excitation or stall conditions are pre empted by logging engine rpm decay rates and then locking the DM's earlier & releasing accordingly.

A nominal threshold to lock the DM's on a reducing speed would be for example; belo...