Search Results

It is a common practice of automotive industry to avoid dynamic contact between two surfaces with similar roughness for plastics and interior trim parts. That means reduce the friction and, consequently the squeak noise to the minimum level to meet zero noise level. Unfortunately, for design or economics reasons, that is not possible for some applications and a very disturbing noise may bother the costumer. A material incompatibility leads to an acute noise when two similar surfaces have relative movement due to multiple adherences between the surfaces, that is called stick-slip phenomenon. To characterize this noise, a Squeak and Rattle Evaluation testing should be performed in the worst case condition over the life of the vehicle. As a result, a scale of Risk Priority Number (RPN) provides a pass/fail judgement to implement any improvement required to address the issue.

The unpleasant noise (creak) originated from latch-striker interaction, perceived mainly when the vehicle is submitted to uneven road conditions is generated by stick-slip phenomenon mainly due materials incompatibility of contact surfaces. Generally, eliminate this incompatibility is unfeasible due technical and/or economics constrains; this scenario makes it necessary to act in other fronts to neutralize the effects of that incompatibility. Reduce the coefficient of friction from one of contact surfaces is an alternative that can be easily applied at striker through a thin thickness coating with that property.

Vehicle sound quality has become lately one of the main topics of study in the automotive industry which is associated with the quality of the product. Into the automotive development the static operational sound quality is one of the attributes that is considered. The sounds produced through the manipulation of items like the doors and interior components (windows, seats, safety belts, windshield wipers, and others) generated for safety and warning purposes are items related to the vehicle quality for customers. Those sounds based on relative level of intensity, duration, harmony and degree of contribution are elements that the customer will retain in mind, an overall quality impression. The sound produced during gear lever manipulation is important to the customer in order that the event should transmit low intensity and robust and soft impression.