1、will reduce the cost and time of the design, manufacturing andassembly of mechanical conveyor systems used in the food andbeverage industry. The improved methodology for design andproduction of conveyor components is based on the minimisa-tion of materials, parts and costs, using the rules of design
2、 formanufacture and design for assembly. Results obtained on a testconveyor system verify the benets of using the improved tech-niques. The overall material cost was reduced by 19% and theoverall assembly cost was reduced by 20% compared to conven-tional methods.Keywords Assembly Cost reduction Desi
3、gn DFA DFM Mechanical conveyor1 IntroductionConveyor systems used in the food and beverage industry arehighly automated custom made structures consisting of a largenumber of parts and designed to carry products such as foodcartons, drink bottles and cans in fast production and assemblylines. Most of
4、 the processing and packaging of food and drink in-volve continuous operations where cartons, bottles or cans are re-quired to move at a controlled speed for lling or assembly oper-ations. Their operations require highly efcient and reliable me-chanical conveyors, which range from overhead types to
5、oor-mounted types of chain, roller or belt driven conveyor systems.In recent years, immense pressure from clients for low costbut efcient mechanical conveyor systems has pushed con-veyor manufacturers to review their current design and assemblymethods and look at an alternative means to manufacture
6、moreeconomical and reliable conveyors for their clients. At present,S.H. Masood (u) Industrial Research Institute Swinburne,Swinburne University of Technology,Hawthorn, Melbourne 3122, AustraliaE-mail: *.aumost material handling devices, both hardware and software, arehighly specialised, inexible an
7、d costly to congure, install andmaintain 1. Conveyors are xed in terms of their locations andthe conveyor belts according to their synchronised speeds, mak-ing any changeover of the conveyor system very difcult and ex-pensive. In todays radically changing industrial markets, there isa need to implem
8、ent a new manufacturing strategy, a new systemoperational concept and a new system control software and hard-ware development concept, that can be applied to the design ofa new generation of open, exible material handling systems 2.Ho and Ranky 3 proposed a new modular and recongurable2D and 3D conv
9、eyor system, which encompasses an open re-congurable software architecture based on the CIM-OSA (opensystem architecture) model. It is noted that the research in thearea of improvement of conveyor systems used in beverage in-dustry is very limited. Most of the published research is directedtowards i
10、mproving the operations of conveyor systems and inte-gration of system to highly sophisticated software and hardware.This paper presents a research investigation aimed at im-proving the current techniques and practices used in the de-sign, manufacturing and assembly of oor mounted type chaindriven m
11、echanical conveyors in order to reduce the manufactur-ing lead time and cost for such conveyors. Applying the con-cept of concurrent engineering and the principles of design formanufacturing and design for assembly 4, 5, several criticalconveyor parts were investigated for their functionality, mater
12、ialsuitability, strength criterion, cost and ease of assembly in theoverall conveyor system. The critical parts were modied andredesigned with new shape and geometry, and some with newmaterials. The improved design methods and the functionality ofnew conveyor parts were veried and tested on a new te
13、st con-veyor system designed, manufactured and assembled using thenew improved parts.2 Design for manufacturing and assembly (DFMA)In recent years, research in the area of design for manufacturingand assembly has become very useful for industries that are con-552sidering improving their facilities a
14、nd manufacturing methodol-ogy. However, there has not been enough work done in the areaof design for conveyor components, especially related to the is-sue of increasing numbers of drawing data and re-engineeringof the process of conveyor design based on traditional methods.Emphasise standardisationU
15、se the simplest possible operationsUse operations of known capabilityMinimise setups and interventionsUndertake engineering changes in batchesA vast amount of papers have been published that have investi-gated issues related to DFMA and applied to various methodolo-gies to achieve results that prove
16、d economical, efcient and costeffective for the companies under investigation.The main classications of DFMA knowledge can be iden-tied as (1) General guidelines, (2) Company-specic best prac-tice or (3) Process and or resource-specic constraints. Generalguidelines refer to generally applicable rule
17、s-of-thumb, relat-ing to a manufacturing domain of which the designer shouldbe aware. The following list has been compiled for DFMguidelines 6.These design guidelines should be thought of as “optimalsuggestions”. They typically will result in a high-quality, low-cost, and manufacturable design. Occa
18、sionally compromisesmust be made, of course. In these cases, if a guideline goesagainst a marketing or performance requirement, the next bestalternative should be selected 7.Company-specic best practice refers to the in-house designrules a company develops, usually over a long period of time, andwhi
19、ch the designer is expected to adhere to. These design rulesare identied by the company as contributing to improved qualityand efciency by recognising the overall relationships betweenDesign for a minimum number of partsDevelop a modular designMinimise part variationsDesign parts to be multifunction
20、alDesign parts for multiuseDesign parts for ease of fabricationAvoid separate fastenersMaximise compliance: design for ease of assemblyMinimise handling: design for handling presentationEvaluate assembly methodsEliminate adjustmentsAvoid exible components: they are difcult to handleUse parts of know
21、n capabilityAllow for maximum intolerance of partsUse known and proven vendors and suppliersUse parts at derated values with no marginal overstressMinimise subassembliesparticular processes and design decisions. Companies use suchguidelines as part of the training given to designers of productsrequi
22、ring signicant amounts of manual assembly or mainte-nance. Note that most of the methodologies are good at eitherbeing quick and easy to start or being more formal and quanti-tative. For example, guidelines by Boothroyd and Dewhurst 8on DFA are considered as being quantitative and systematic.Whereas
23、 the DFM guidelines, which are merely rules of thumbderived from experienced professionals, are more qualitative andless formal 9.3 Conventional conveyor system designDesign and manufacturing of conveyor systems is a very com-plex and time-consuming process. As every conveyor system isa custom-made
24、product, each project varies from every otherproject in terms of size, product and layout. The system designFig. 1. Layout of conveyor sys-tem for labelling plasic bottles553is based on client requirements and product specications. More-over, the system layout has to t in the space provided by theco
25、mpany. The process of designing a layout for a conveyor sys-tem involve revisions and could take from days to months or insome instances years. One with the minimum cost and maximumclient suitability is most likely to get approval.Figure 1 shows a schematic layout of a typical conveyorsystem install
26、ed in a production line used for labelling ofplastic bottles. Different sections of the conveyor system areidentied by specic technical names, which are commonlyused in similar industrial application. The “singlizer” sec-tion enables the product to form into one lane from multiplelanes. The “slowdow
27、n table” reduces the speed of productonce it exits from ller, labeller, etc. The “mass ow” sec-tion is used to keep up with high-speed process, e.g., ller,labeller, etc. The “transfer table” transfers the direction of prod-uct ow. The purpose of these different conveyor sections isthus to control th
28、e product ow through different processingmachines.A typical mechanical conveyor system used in food and bev-erage applications consists of over two hundred mechanical andelectrical parts depending on the size of the system. Some ofthe common but essential components that could be standard-ised and a
29、ccumulated into families of the conveyor system areside frames, spacer bars, end plates, cover plates, inside bendplates, outside bend plates, bend tracks and shafts (drive, tail andslave). The size and quantity of these parts vary according to thelength of conveyor sections and number of tracks correspond-ing to the width and types of chains required. The problems andshortcomings in the current design, manufacturing and assemblyof mechanical conveyors are varied, but include:4 Areas of impr
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