Study of the Relationship between DTV, BTV and BPV over Judder-Type Vibration of Disc Brake Systems Fras-Le SA

Format:

Conference/Event

Author/Creator:

Jardim, Jardim, author.

Contributor:

Tamagna, Alberto

Conference Name:

SAE 2010 Annual Brake Colloquium And Engineering Display (2010-10-10 : Phoenix, Arizona, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Vehicle brake judder is a vibration phenomenon responsible foran expressive number of customer complaints. In order to preventjudder from occurring, new vehicle developments are putting inpractice dynamometer and vehicle brake tests to assess the DTVgrowth and the effectiveness of applied countermeasures, whennecessary.The measurement of DTV is very sensitive and requires highprecision sensors. Due to these facts, incorrect DTV measurementsare not uncommon, since the rig or vehicle setup, theassembly/disassembly of the sensors or brakes and even thevibration of the dynamometer itself may figure as sources formeasurement errors. In the other hand, if the test vehicle ordynamometer is equipped to acquire brake torque and brake pressurevariations (BTV and BPV, respectively), those measurements maysuffer less interference from external parameters and present goodrelationship with DTV and judder.As a study to verify this correlation, discs in different levelsof DTV were prepared and assembled on a vehicle, instrumented tovibration measurements. A test procedure with snubs at differentpressures was carried out with each disc, as a way to evaluate thecondition for critical judder. After that, the same procedure wassimulated in an inertia dynamometer, were the BTV and BPV weremeasured against the different levels of DTV.As a result it was observed that theBTVrelativemeasurement, as well as theBPVmaximummeasurement, in snubs with pressure between 30 and 50 bar, presentwell-defined levels which allow identifying if a brake disc DTV isabove the acceptable limit for non-generation of vibrationsclassified as uncomfortable. From this observation, the conclusionis that brake test procedures can incorporate additional snubs withpressure in the range of 30 to 50 bar, in strategically definedstages, where theBTVrelativeand/orBPVmaximummeasurements may figure as part of the criteria for brakeapproval

Notes:

Vendor supplied data

Publisher Number:

2010-01-1694

Access Restriction:

Restricted for use by site license