Does your new Electric Vehicle make annoying sounds?

12/1/2022 / Author: Michael Koper

According to a recent JD Power survey, one of the top complaints that new EV car owners commented on was the noise from either the road or the wind generated when driving their new EVs’. Much of the annoying noises come from pothole-filled roadways, aggressive tire treads humming, and poor fit and finish from misaligned car body parts. Known as cabin noise, many manufacturers publish the cabin noise in decibels (dB), typically stated in the range of 60-90 dB are the acceptable level of cabin noise. The problem is most of the measurements are taken under controlled conditions yielding the best possible results that do not reflect the road conditions or other environmental situations encountered in everyday driving.

Automakers constantly challenge design teams to reduce noise, known in the industry as “NVH”; noise, vibration, and harshness. With traditional ICEs (internal combustion engines), the engine generates a certain amount of noise during its operation. Some models have exhausts designed to accentuate the engine’s roar, thus increasing cabin noise. With today’s EV, engine noise is non-existent. However, this makes the reduction of NVH even more crucial, so the driver doesn’t hear all the environmental noises, such as wet road surfaces, wind whistles, and vehicle rattles. Remember that rattles occur in many cars due to use conditions, loose fasteners (consisting of clips, screws, bolts, rubber grommets, etc.), and poorly fitting body panels. Design and manufacturing teams cannot control operator driving conditions; however, they can control the torque settings of fasteners and the alignment of body panels.

Fit & Finish

 

The measurement of body panels is known as the Flush and Gap metrology methodology taken during vehicle manufacturing. Each vehicle assembled is measured against the design parameters set forth by the design teams. Generally, most gaps (door to door, door to fender, fender to hood, headlamp to hood, windshield to roof, etc.) are 1.25mm to 2mm in size, holding a tolerance of +/-0.3mm, and flushness is the measurement of how the surfaces of the panels align with one another. Ideally, alignment is 0mm. When a vehicle is assembled with wide gaps or out-of-alignment panels, it’s subject to improperly tightened or missed fasteners, spacers, or deficient critical spot welds. Misassembled vehicles can cause automakers warranty issues and poor customer reviews. One solution to these manufacturing issues is the Eines Eifis® Flush N Gap measurement system.

The Eines Eifis® Flush N Gap measurement tunnel provides hundreds of points of accurate measurement on assembled or semi-assembled vehicles. This critical measurement system scans while the vehicle moves without touching the surface. Additionally, the system guides the fitters in the auto plant to the exact location to make necessary adjustments or alignments.

In the age of world-class manufacturing, does your quality depart measure 100% of all assembled vehicles? Many of the plants I enter currently measure a sampling of vehicles manually, leaving it to chance that the unmeasured vehicles meet manufacturer specifications.

Do you want to learn more about reducing NVH and measuring 100% of all vehicles manufactured?


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