Using Failure Mode and Effects Analysis to design a comfortable automotive driver seat.
Given enough time and use, all designs will fail. There are no fail-free designs. This is especially true when it comes to automotive seating comfort where the characteristics and preferences of individual customers are many and varied. To address this problem, individuals charged with automotive seating comfort development have, traditionally, relied on iterative and, as a result, expensive build-test cycles. Cost pressures being placed on today's vehicle manufacturers have necessitated the search for more efficient alternatives. This contribution aims to fill this need by proposing the application of an analytical technique common to engineering circles (but new to seating comfort development), namely Design Failure Mode and Effects Analysis (DFMEA). An example is offered to describe how development teams can use this systematic and disciplined approach to highlight potential seating comfort failure modes, reduce their risk, and bring capable designs to life.
Critical Design Factors on Performance of Car Jack Lifting Operations
Car jack is an equipped accessory package in every units of car sold to customer that used to uplift the cars while replacing tires during an emergency or repair. The automotive manufacturers are actively conducting their Product Improvement Campaign and the objective of the campaign is to improve the quality of product sold to the customers. The current jack design has a possibility of failure during its operations. The customer satisfaction point of view will be converted to engineering characteristic to acquire the concept of design and input into new design proposal and at the same time eliminate the possibility of failure of the current design. The research is conducted to improve the current jack design on its performance in lifting operations. The scope of research is to identify the critical zone in jack design structure that possibly causing the failure during its operations. To optimize the existing design, it is proposed some modification on the jack structure with a minimum weight increment but improve the design structural strength. The failure root cause analysis, reliability test and Design Failure Mode and Effect Analysis have been used to identify the specific critical area in the structure and resolve them by proposing the new improved jack design. The current car jack sample in market is used as an industrial sample for design analysis to find the target area for further improvement. From the analysis, we can know the critical design factors in the current car jack design and the required design improvement to enhance its performance in lifting operations.
Spine Load in the Context of Automotive Seating
In modern society the automobile is an essential companion in everyday life. Be it commuting to and from work or during our leisure time - every week most of us spend many hours sitting in their car. In this context the seat is the main interface between the human being and the automobile itself. Functioning well, this close relationship can foster the well-being of the passenger and raise his spirit; being flawed it can otherwise cause severe pain in the back after a longer journey. Thus, for car manufacturers, the aspects of seat comfort are becoming more and more prominent in distinguishing themselves from their competitors. Despite its importance the development of comfort parameters in automotive seating is still being consigned to the subjective judgements of a poor number of seating experts or randomly selected test subjects. Easily influenceable by parameters like affection, physical conditions or environmental factors and a lack of standardization these subjective evaluations have a big intra individual and inter individual range. A first approach to improve the objective judgement of an automotive seat was made by the concept of ``optimal'' load distribution (Mergl, 2006; Zenk, 2006 ), based on the identification of a close interconnection between the pressure on the seat and the discomfort felt by the person sitting on it. In the next step further objectification of seat comfort will be achieved by an in vivo measuring of the pressure in the spinal disc, which is a reliable indicator for the load in the spine. For this experiment a pressure sensor is implanted with a canula in the middle of an intervertebral disc of a voluntary subject. In this way the local pressure on the disc is measured in an automobile, concentrating on the very seat settings which cause pain in the upper back. The significant lowest pressure values (0.5 bar) are achieved in an ideal seat position with an ``optimal'' load distribution. By contrast the pressure on the disc increases by load distributions differing from an optimal one. From these results we will be able to improve our knowledge on how to avoid uncomfortable seating in automobiles and start making well-founded recommendations for seat design.