VEHICLE N.V.H. (NOISE, VIBRATION AND HARSHNESS)

Development of the entire automobile is the primary responsibility of the Car Product Engineering Office. It provides for the compatibility of components such as axle, frame, body, ect., in respect to the final vehicle package, by having a section of the Vehicle Engineering Office, composed of Development Engineers, Solely responsible for improving N.V.H. characteristics to the degree needed to meet the established model image. The initial phase of an N.V.H. improvement program is to determine the various problems. Most of the N.V.H. problems are in one of the following categories: 1. Shake--A 10 to 20 cps vibration excited by wheel rotation and wheel hop disturbances to which the body and frame respond. 2. Harshness--A 15 to 70 cps vibration that produces a hard tire sensation for the body and frame response. It is closely aligned with shake. 3. Boom--An audible 30 to 50 cps vibration which is set off by drivetrain and tire and wheel excitations. It is associated with a pressure sensation in the ears caused by a standing wave effect. 4. Driveline Rumble--A 70 to 80 cps vibration, known as first mode powertrain bending, excited by the drivetrain rotation forces. 5. Tip-in-Moan--A 90 to 140 cps vibration, known as second mode powertrain bending, excited by the engine firing impulses on light acceleration. 6. Axle Noise--A 250 to 500 cps vibration set off by axle gear tooth contact frequency. 7. Gear Rattle--A 40 to 100 cps vibration caused by manual transmission gear lash during low speed acceleration in high gear. 8. Accessory Rumble and Whine--Vibrations ranging from 30 cps up through the audible range, produced by engine accessories. 9. Road Noise--A 50 to 200 cps vibration excited by road surfaces.

  • Corporate Authors:

    Ford Product Engineering Office

    Dearborn, MI  USA 
  • Authors:
    • Alexander, R W
  • Publication Date: 0

Media Info

  • Features: Figures;
  • Pagination: 12 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00261256
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 22 1974 12:00AM