Umbrella 2
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+ | While a number of improvements could potentially be made for an umbrella design, we also acknowledge that a cheaper but less durable umbrella will continue to be a part of the market despite greater quality being available. We believe that this is mostly due to what we suspect as customer ignorance of overall purchasing impact of what is comparable to one time use products or personal taste, i.e. paper plates over ceramic. We would like to do more research into consumer habits and ideology to determine if this is a point worth addressing in the overall umbrella market and lifecycle improvement. In the specifically mechanical sense, we found greater difficulty in suggesting specific improvements, as an enormous variety of designs of differing mechanical basis are used in the market. Regarding the design we dissected, it seemed that some parts could be condensed into fewer components, or that use of a stronger or thicker overall material would improve umbrella life, but we recognized the inherent cost increases associated with these changes. We especially saw this when using the EIO-LCA to extrapolate the increased manufacturing costs. Because we know there are so many variations of umbrellas, some optimized for cost, some convenience, we saw that no one variation could ever address all potential issues, and that similar to spaghetti sauce or gum flavors, different varieties were a necessity based on consumer need and variety demand. In summation, we learned a great deal about what factors determine producer and user costs, which materials and processes impact the environment most, and how “green engineering” is not simply a responsible choice, but also should be accompanied by an associated economic trend towards recyclability for more cost effective products. We believe that the current lack of efficient end life processing, and the fact that simple reversible failure modes are not being addressed, canopy tear patches, bent spoke realignment, are the areas which an umbrella production market need to be concerned with most. |
Revision as of 16:44, 6 February 2011
Contents |
Executive Summary
Our team chose to analyze a standard collapsible umbrella. This decision was prompted by an acknowledgment that the device is widely used, has many variations and its universal application as a rain protection device. We conducted a study to illustrate proper use and operation, but also to discover what and when issues arise with an umbrella. As expected, most of our concerns were centered on different ways that the umbrella can fail to keep its user protected from precipitation, but also with durability in response to repeated elemental punishment or daily use. Performing a product dissection, enabled us to tabulate all individual components based on part weight material and other relevant metrics, and sub-assembly analysis gave us significant insight into how and why an umbrella might fail and how that is directly related to its design and manufacturing processes. In analyzing the different possible modes of failure, we confirmed that almost all problems are either with canopy tears or removal, or dynamic breakdown, i.e. the umbrella will no longer open and/or close properly due to plastic deformation of components. Analyzing the manufacturing processes and involved costs showed us why we were observing these problems. Umbrella convenience was linked heavily to weight, size and cost, the optimization of which necessitates using less material, especially in structural components like the spokes, which reduced the umbrellas durability. Thus, when an umbrella canopy inverts, the spokes likely suffer some deformation or weakening when the user flips it back to the proper configuration, leading to a shorter umbrella life when a part eventually fails. If, however, along the lines of a cobbler, there were provisions for umbrella repair, we believe more efficient materials could be used in manufacturing as users could justify the increased cost paid as they saw associated life extension. All in all, we predict that we will not truly be redesigning an umbrella per se, but more likely an accompanying device which either dries or in some way repairs common issues, if we find that the market is ripe for such developments.
Major Stakeholders and Product Needs
Consumers
- Appealing
- Durable
- Lightweight
- Effective
- Safe
- Easy to use
- Portable
- Inexpensive
- Comfortable to hold
- Easy to clean/dry
Retailers
- Ease of storage
- Cost/Profit
- Durability
- Customer Satisfaction
Product Function
The operation of this particular umbrella was very simple. The pictures below depict the general use of an umbrella.
The umbrella consists of a handle which is connected to a telescoping shaft. The telescoping shaft is a mechanism that extends in order to expand several mechanical arms, or spokes, outward when the umbrella is in use. The extension of these spokes serves to expand the canopy, made of polyester, producing a dome shape. This dome shape deflects rain and snow from reaching the user. The concentric tube is located at the top of the shaft. It holds the spokes firmly together and is used to extend the telescoping shaft. There is a locking mechanism also located at the top of the telescoping shaft so that the canopy does not close when the user is holding the umbrella. To collapse the umbrella, the concentric tube is pulled downwards to shorten the telescoping shaft and contract the spokes. The umbrella is then stored.
To use an umbrella the following steps are taken:
Usability Study
After using this particular umbrella, numerous issues have been encountered. The polyester material is very loosely connected to the spokes. This results in an ineffective umbrella where the area of coverage from preciptation is decreased. Furthermore, the spokes of the umbrella was observed to have many moving parts. The outcome is a sacrifice in strength. A common outcome is bending of the spokes due to excessive winds. We noted that a stronger mechanical design for the spokes was needed for the umbrella. Additionally, precipitation contacted the user during use when high winds was present. During our study, snow reached the user in a direction perpendicular to the position of the umbrella. This also diminished the effectiveness of the umbrella. Finally, storing and cleaning the product was a major issue. It was observed that after use, many users commonly shake off the excess water from the umbrella onto the floor of the location they enter.
Mechanical Function
There are 2 mechanical functions of the compact umbrella. The first is to extend and contract the shaft of the umbrella. How this is done is by making the shaft telescoping. Three separate metal shafts are connected together and are allowed to collapse into itself. When the shaft is extended it is held in place by 2 ball bearings for each connecting shafts. These ball bearings lock into place and prevent each individual shaft from moving. The second function is to open and close the canopy of the umbrella. This is done by the use of a four-bar linkage which consists of the spokes, spokes support and concentric tube. The concentric tube controls the extension and contraction of the spokes. As the concentric tube is pushed up the shaft the spokes extends and vice versa. The 8 spokes supports are connected to the concentric tube by a steel wire.
Bill of Materials
Assembly Diagram
The image below depicts the major components of the product.
The image below shows a more detailed look at the more intricate portion of our product.
Design for Environment (DFE) Analysis
When creating a product, engineers must address the potential impact on the environment during the development process. A Design for Environment, DFE, analysis was conducted by our group. We aimed to identify the environemental impacts by utilizing an Economic Input-Output Life Cycle Assessment (EIO-LCA) of an umbrella. Furthermore, we also strive to determine the impact on the cost of production if Congress were to pass a tax on the CO2. This was accomplished using Carnegie Mellon’s EIO-LCA website. We calculated the greenhouse gases and toxic releases associated with our product, assuming $1 million dollars of ecnomic activity was used in the sector: #33299C: Other fabricated metal manufacturing. We have decided that this sector best contains our product as it includes the main material used in life cycle of the product: aluminum. Although our product contains textile components, we have chosen not to consider the textile manufacturing sector as our product contains mostly aluminum by weight. During our analysis, we concluded that there were no known energy inputs during the use phase of the life cycle assessment. Therefore, we have chosen to disregard an examination on the potential impacts on the enviornment from umbrella usage. The results from using the EIO-LCA website are summarized in the following tables. The energy in Tera Joules (TJ), emission of greenhouse gases, in metric tons of CO2 equivalent (MTCO2E), and toxic releases from the top 5 contributors of the production phase of the product are shown below.
Energy
The table below shows that when an additional 1 million dollars is spent in the sector, Other fabricated metal manufacturing, there is an increase of 12.5 TJ of energy.
The results show that the majority of this increased energy is produced by Power Generation & Supply. Approximately 25% of the increased energy is derived from this sector.
Greenhouse Gases
The table below shows that an additional 1 million dollars spent will result in an increase of 839 metric tons of CO2 Equivalent (MTCO2E).
The results indicate once again, the large role of the Power Generation & Supply sector. This sector is responsible for nearly 31% of the increased emissions. However, the sector that contains our product has a smaller role. The Other fabricated metal manufacturing sector contributes about 7% of the increased emissions.
Toxic Releases
An additional 1 million dollars spent in the sector, Other fabricated metal manufacturing, will also result in an increase in toxic releases by 703 kg.
Results of our analysis indicate that the Gold, silver, and other metal mining sector is responsible for an overwhelming 91% of the increase in amount of toxic releases. The sector, Other fabricated metal manufacturing, is only responsible for approximately 1% of the increased toxic releases.
Life Cycle Assessment (LCA)
The emissions associated with umbrella manufacturing from the sector: #33299C: Other fabricated metal manufacturing are presented in the table below. The table also shows what the implied CO2 tax will be assuming Congress passes a tax of $30 per metric ton equivalent of CO2. Again, we concluded that there are no known energy inputs during the use phase of the life cycle assessment, aside from that of the user. Therefore, we have chosen to disregard umbrella usage from the life cycle assessment.
DFE Conclusion
Based on the results of the Life Cycle Assessment, we concluded that most of any life cycle improvements would be in the manufacturing processes, and specifically in the amount of, and methods used to manipulate, the aluminum components, or else in a dynamic shift in user behavior. This conclusion seemed reasonable, as we assume that there will always be some sort of canopic textile, and that umbrellas will presumably not begin to utilize noticeable energy during their use phase, but people may be convinced to repair a more expensive model or require a drying device to increase their convenience. However, although choosing to mostly ignore the end life processing in our analysis, we believe that a significant difference can be effected through the implementation of a recyclable design, or a more durable overall design, and that GHG emissions can be lowered. If more umbrellas stay in use, then less will be purchased, and presumably demand decrease will necessitate supply decrease and less manufacturing means less power usage and consequently emissions, while also easing the burden on landfills, and raw materials gathering.
FMEA
The conventional compact umbrella was designed for portability and cheapness. However in doing so durability and robustness is sacrificed. The parts with the highest RPN number was found to be at the spokes sub-assembly and the canopy. These 2 parts are the most likely parts that fail and break in the lifetime of an umbrella. The spokes are lightweight and very flimsy and tend to bend and break from either impact or wind resistance. The canopy tends to rip and tear in the connection joint of the spokes and canopy. The spokes can be made more robust and also be lightweight if less parts were used for the assembly and if different material was used. For the canopy instead of using threads to tie it to the spokes, a clip on attachment or velcro will be suffice.