| Taking the sofa frame-grouping work in a furniture enterprise in Shandong province as theresearch object, based on the human engineering principle, using the method of industrialengineering as a guide, the job content，work time，production posture，metabolic rate andheight etc., of the sofa frame-grouping work were studied by field measurement,human-machine emulation and field experiment method in this paper, to find ways to improvethe work efficiency and reduce the operation fatigue. The main conclusions are as follows:(1) The sofa frame-grouping work efficiency is far below the predictive inference leveland has enough space for improvement. Sofa frame-grouping operating mode is not uniform,which lead to a significant difference in working efficiency among workers. The total effectivetime (T1) and total invalid operation time (T2) of four workers respectively account for88.10%and11.90%of the total operation time (T). Preparation and operation is the main work contentsof the sofa frame-grouping work.(2) Sofa frame-grouping typical postures are upright, bending forward, stoop and squat;squatting operation time account for51.73%of the total operation time. And the four kinds ofpostures account for83.14%of the total survey time. Heavy air nail gun and longtime squattingwork lead to shoulder and leg fatigue symptoms.(3) By using the software of3DSSPP, the typical working postures in the sofaframe-grouping work were analyzed. The results show that average pressure in the L4/L5andL5/S1lumbar disc is the biggest when using squat posture. The average shear force has theL4/L5and L5/S1lumbar disc is the biggest in stoop posture. Stooping operation is not ideal tokeep balance and stoop posture cannot keep for a long time. Squat and stoop postures can causethe waist injury to operator easily.(4) By using EEPP software, the typical process of sofa frame-grouping work was analyzed.Energy metabolism rate of frame-grouping is4.30kcal/min, and the result is beyond the energymetabolism of standard which E.A. Miller suggested. If you don’t rest will cause the fatigueaccumulation.By calculation, if accumulation time rate is7.50%, it may not cause fatigue, andthe frame-grouping action is a major cause of fatigue. Through the calculation, according to ourstandard (GB3869-83), the sofa frame-grouping work belongs to the second polar physicallabor.(5) By improving the sofa frame-grouping work height, the operators’ bad postures can becorrected and work fatigue is reduced, with the improvement of operational suitability and workefficiency. There was a significant positive correlation at the level of α=0.01between theoperational suitability and fatigue degree of the working height. The height of600mm-700 mm in sofa frame-groping work can satisfy the stitching work for the most sofa framecomponents.(6) The sofa frame-grouping auxiliary operation tool design includes table, wood placingrack and the tool holder. The traditional operation modes and production efficiency can beeffectively improved by use of these tools.(7) Optimization of sofa frame-grouping operation space including the sofaframe-grouping station space layout and the workshop layout design. The optimized sofaframe-grouping station space size is8000mm x6200mm, with a20%decrease in occupiedarea. Every area has been divided clearly and effectively used. The optimized the workshopcovers an area of880square meters, about24%less than before and the workshop utilizationrate is improved by17%. The problem of logistics main channel blockage has been solved bythe improvement of logistics channels.(8) The improvement of the optimization scheme is simulated by using the EEPPsoftware.The result shows that the optimized workers P3finish6PCS double sofa seat frame(size:1170mm×920mm×160mm) connection, the operation time reduces by213s, with theefficiency increasing by12.97%. Moving distance is reduced by61.5m and decreases by73.65%than before. The optimized preparation and frame-grouping work of energy metabolic rates areall in the range of E.A. miller suggested value and the energy consumption is reduced by91.51%and28.65%respectively. Thus, the optimization scheme of sofa frame-grouping work cansignificantly improve the work efficiency and fatigue, which has some reference value. |
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