Manufacturing Plan For Wing Of PAV

Manufacturing work outes atomic number 18 differed according to the fabrication techniques much(prenominal) as sheet metal underframeing and machining processes. For the wings of a new personal dividing line vehicle (PAV) skins ands ribs be generated by sheet metal forming process and spars argon produced by machining process. Finally all produced move be assembled together to produce lowest wing structure.In addition, since the comp matchlessnts that build up ailerons and flaps be very similar to wing structure, manufacturing techniques utilize for skins, ribs and spars argon also reasonable for them. Since there should be actuator and hinge fittings to connect ailerons and flaps to wing structure, they be considered in machined move manufacturing process section.SKIN MANUFACTURINGManufacturing process of skins is shown in dactyl -1 course-1 1Tools for sheet metal forming trading operationsStretching Dies, Drill fixtures, drill plates, holding toolsFirst CutAluminu ms Raw Materials atomic number 18 cut by trim machine or hand router to get available sizes for manufacturing with much luxuriant excess portions.Heat TreatmentBlanks argon hence solution fondness treated to provide necessary mechanical properties to the split. Heat discussion operations are done according to the design requirements which are defined by engineering drawings. Heat word processes are applied to make split generally T4, T5 or T6 tempers.Stretch Forming SkinsOn the deprave pack together, skins are stretch formed and their tooling spates are marked. afterward removing the skins from stretch getes, the marked tooling holes are drill for succeeding fabrication operations. An example of stretch forming process is shown in class 2.Figure 2 2Skin RoutingRouting operation could be done with devil techniquesThe first one is using a routing shell tool which has cardinal parts which have exactly same form of the skin. The skin is then conciliated in between them which is fixed with the tooling holes previously undefended by and by stretching and a hand router is traveled around the tool to circumstance the skin to its final contour. A photo of a router shell is shown in Figure 3.The second technique is using a five bloc gantry routing centre with flexible vacuum assisted table. The skin is positioned with the assist of vacuum assisted columns as shown in Figure -4 and tooling holes are utilise to clothe the machining coordinate axes.Figure 3 3Figure 4 4During routing operation, take turns holes are also drilled. Also during routing operation, excess portions like access openings or nearwhat pockets are removed from the skin. pop out TreatmentSurface treatment operations are also defined by the engineering drawings. most of the surface treatment operations applied are rinsing for miserableing, chromic stinging anodizing, primer and cover for corroding preserveion. Primer coating and video are also called as Chemic al Conversion Coating (CCC) which is beneficial for bust prevention.In our case, chromic acid anodizing is applied to 2024 skins for preventing corrosion and paving the way for painting. onward chromic acid anodizing, fine holes should be masked to keep holdings faithful.A classifiable anodise process would consist of a solvent wash and/ or an alkaline clean to remove any oils or greases from the surface. followed by a de-oxidiser stage to remove the natural oxide film from the surface, followed by chromic acid. This pretends you a clean oxide free surface which once anodised will give better chemical bond of the anodised layer. There is a water rinse stage between each tank to prevent contamination of the bath solutions. From there you have cardinal choices, spray directly onto te anodise honeycomb structure which will give good paint adhesion, or seal the anodised layer for enhanced corrosion protection but poorer paint adhesion.PaintingFinally, primer, top coat and final paint are applied on the skin.RIB (SHEET METAL) MANUFACTURINGManufacturing process of ribs is shown in Figure 5Figure 5 1Tools for sheet metal forming trading operationsHydro press forming dies, Drill fixtures, drill plates, holding toolsThe main difference of manufacturing of ribs from skins is hydro press forming process preferably of stretch forming.Hydro press FormingAfter heat treatment, blanks pay back ready to be formed. In aerospace industry fluid cell forming (hydro press forming) is frequently utilize for forming operation. That is generally because of the reality that aircraft parts are make in elfin quantities and parts are mostly different in geometry. Therefore it is necessary to manufacture a different tool for either part and that is very costly. Although the machine is quite expensive, to decrease the tooling costs, hydro press forming is preferred since only male dies are necessary to form parts instead of male-female die combination. That is illustrated in the figure. Also an some other advantage of hydro press forming is that, on the table of the press machine, several tools, with the blanks on them, could be located promiscuously at once. In one cycle all the parts are formed simultaneously. Also in general press machines are equipped with two tables which make it possible to decrease set up season to half. nigh photos related with hydro press forming are shown in Figure 6.Figure 6 4SPAR, HINGE, RIB AND FITTING MANUFACTURINGManufacturing process for machined parts, spars, hinges, ribs and fittings is shown inFigure-7Figure 7 1Tools specific to machining operationsMilling fixturesMachiningIf necessary those parts which will be machined on hoagieing centers, are firstly cut from blocks of raw sensible to their required deport sizes. They are mostly skin milled. Skin mill is done to obtain a smooth flat plane to locate the stock on the mill machine table. After skin mill, some holes are drilled on the stock for the sake o f transportation and hook on the machine tables or fixtures. For complex milling operations in which there are more than one stages of operations, it is common to use a milling fixture, see Figure -8. Another reason for use of milling fixtures is that in aerospace industry manufacturing tolerances are so tight and geometries are mostly very complex that is why it is necessary to provide same machining conditions and set up for every single part. Milling fixtures are tools, on which stock material is located and clamped. Their main functionality is that they hold the machined part tightly passim the machining process which prevents machining defects and dimensional inaccuracies.,Figure 8 4To obtain required dimensional tolerances, some holes require boring. Boring operation removes only a small quantity of material therefore before boring operation the hole must be drilled very close to the final dimension of the hole diameter.Dimensional accuracy of the machined parts are general ly check over with the utilization of Coordinate Measuring Machines (CMM). These machines are very precise such as they are capable of measuring ten thousands of a millimetre in three dimensional spaces. Although they are quite expensive and they necessitate an air conditioned, humidity controlled and vibration isolated chamber, they are the most accurate and flexible measurement equipments.Shot PeeningMachined parts are exposured to shot peening operation. That process is done to remove and minimize the existing surface cracks on the machined parts. Machined parts are generally bear high amount of repetitive tensial and compressive lashings and these repetitive loading is mostly the main cause of fatigue failure. Surface cracks are the mostly affected defects from repeated loading and they tend to originate under these conditions. That is why they must be removed or minimise to prevent them to grow and increase the fatigue durability of the part.Surface treatmentAs explained before both chromic acid anodizing, primer coating and painting are the surface treatment operations applied on the parts to make them resistant to corrosion. Another advantage of these chemical conversion coating processes is that they make the part more durable to the fatigue, since they penetrate to surface cracks, scratches and holes. For instance, rowdiness is a corrosion type which is more susceptible to such surface defects. Therefore surface treatment processes both provide a defensive coating in corrosive environments and they generate a smoother silky surface, which is a requirement to decrease air drag, especially for the outer surfaces which are in contact with the air during flight.ASSEMBLY OPERATIONSAssembly Operations are shown in Figure 9Figure 9 1Tools for collection operationsAssembly and sub conference trip the light fantastics and fixturesAssembly JigIn aerospace fabrication processes, since the parts have very complex geometries and position tolerances a re so tight, it necessary to use a fixture to locate parts in their required positions and apply assembly joining operation in these positions without letting them to move. For an air plane wing a single assembly jig could be use for this purpose, see Figure 10.Figure 10 5Spars are located on the jig. They must have a planate smooth contact surface and they must have previously opened tooling holes. Those holes are used to pin the spar on the jig and some clamps are used to fix the spar in its position.Ribs are located. They are installed on the jig with the utilization contacting surface of spar and some other location surfaces and they are pinned from their tooling holes. Clamps are used to fix ribs in their location.Some of the holes are transferred from ribs to spars or the contrary.Bottom skin is loaded on the jig by the aid of tooling holes on the lugs at each lateral short edge. To wrap the rib spar assembly the skin could be touch by some belts or some header plates coul d be used to bring the skin to its required form and clamp it to hold it in its required position.Some of the tack holes on the skin are attach with clecos, which is a temporary fastener. Pilot holes are drilled to their final sizes and countersinking is applied to locations where countersunk rivets and bolts will be used.After drilling and countersinking is applied parts are separated to remove chips.Before putting parts together again, sealer is applied. Sealant is a viscous chemical isolation material which is a polymer in general (polyurethane, polysulfide, etc). It is applied when it is still in fluid form and it solidifies as a result of chemical reaction which takes place as soon as the sealer is exposed to air. They are used to prevent fluid leakage into internal structural components. This leakage could result blasting failure since corrosion which erodes material would work against the mechanical strength and ineptness of the structure. For different purposes and for d ifferent locations specific types of sealants are applied. For instance polysulfide based sealant is applied to the surfaces where there is fuel content. For fuel tanks these polysulfide based sealants are used since they withstand the attack of sulfur compounds that are pre direct in fuel.After sealant application, outer skin is brought to close the wing and it is fastened with dodge rivets and bolts since it will only be possible to reach rivet from one side.When riveting and bolting completed the wing is removed from the assembly jig and it is sent to paint shop for the application of top coating and painting. After that manufacturing and assembly operations will be completed.