Design and Technology - Lab Report Example

Design and Technology Introduction Design for assembly can be defined as the process of systematic anlysis aimed at symplifying the structure of the product as well as reducing the products asembly cost.In the case the assembly quality of the product is associated with the number of parts.The DFA technique can enable the rating of the assemblability by the designers quantitatively (Pugh 1991).The Technique as well ensures the rules of DFA are strictly adhered to and correct improvement and evaluation of the influencing factors (El Wakil 1998).The achievement of design improvement can be by review and interpretation of the results that have been evaluated.Furthermore, the technique as well has the capacity of intergrating components that could probably be removed as a whole or put together with other parts.Lastly, DFA index is very critcal assembly efficiency indicator of the component design.This value is directly proprotional to the design efficiency. Support Assembly efficiency of the Manual assembly can be desagnated as: Ema=Nmin xta/tma Where: Nmin represents the theoretic least number of components Ta represents the time of assembly for a single part Tma represents the time estimated for the completion of the product assembling The major product to be improved using DFA is Pneumatic piston assembly Figure 1 shows the exploded diagram of the product with dimensions and order of assembly Figure 1.The original design of the pneumatic piston Pneumatic piston design improvement is shown in figure 3 where, assembly efficiency was used.Figure 1 above shows the pneumatic piston original design.Furthermore,the attached worksheet corresponds to the subassembly and it is observed that the design efficiency is 29 percent( figure 2). 1 2 3 4 5 6 7 8 9 Name of assembly Part I.D.N0 Number of times the operation is carried out consecutively Two-digit manual handling code Manual handing time per part Two –digit manual insertion code Manual insertion time per part Operation time, seconds (2)*[(4)+(6)] Operation cost, cents 0,8*7 Figures for estimation of theoretical minimum parts Part name P or c s t β α 6 1 30 1.95 0 1.5 3.45 1.38 1 Main block 5 1 10 1.5 2 2.5 4 1.6 1 piston 4 1 10 1.5 0 1.5 3.0 1.2 1 Piston stop 3 1 5 1.84 0 1.5 3.34 1.34 1 spring 2 1 23 2.36 08 6.5 8.86 3.54 0 cover 1 2 11 1.8 39 8 19.6 7.84 0 screw 42.25 16.90 4 Design efficiency = 3×NM/TM 0.29 TM CM NM Figure 2.Pneumatic piston assembly worksheet Figure 3 show s the redesigned pneumatic piston and it is with the worksheet (figure 4) that corresponds to its subassembly. it is observed in the worksheet that the design efficiency is 90 percent. Figure 3. The new design of the pneumatic piston 1 2 3 4 5 6 7 8 9 Name of assembly Part I.D.N0 Number of times the operation is carried out consecutively Two-digit manual handling code Manual handing time per part Two –digit manual insertion code Manual insertion time per part Operation time, seconds (2)*[(4)+(6)] Operation cost, cents 0,8*7 Figures for estimation of theoretical minimum parts Part name P or c s t β α 4 1 30 1.95 0 1.5 3.45 1.38 1 Main block 3 1 10 1.5 0 1.5 3.0 1.2 1 Piston 2 1 5 1.84 0 1.5 3.34 1.34 1 spring 1 1 10 1.5 0 2 3.5 1.4 1 Stop and cover 13.29 5.32 4 Design efficiency = 3×NM/TM 0.9 TM CM NM Figure 4. Redesigned pneumatic piston assembly worksheet The applied DFA method might be extended to a high speed robot and automatic assembly. It has been found to be very critical majorly in situation redesigning whereby the operational times detailed knowledge is well known or it could be calculated for the given product(Pugh 1991).In addition to this DFA technique explored in detail other techniques of assembly evaluation do exist and include Lucas and AEM DFA methods (El Wakil 1998) Summary In summary, assembly efficiency is considered to be a very critical measure or index in the DFA technique. It can be employed in the evaluation of product assembly and it determines whether the design can facilitate the assembly of the product with the aim of providing a foundation to the effective improvement of the design Figure 2 show s the redesigned pneumatic piston and it is with the worksheet that corresponds to the subassembly. When the worksheet of the original design and new design are compared, it is evident that in the new design, the assembly efficiency increased by 90 percent where the original design had 27 percent, assembly efficiency. References El Wakil, S. D. (1998) Processes and design for manufacturing. 2nd edn. Boston: PWS Publishing Company Pugh, S. (1991) Total design: integrated methods for successful product engineering. Harlow: Pearson Education Read More