Research On Evaluation Method Of The Assembly Operation Ergonomics For Transmission

In the past decade,the pace of development of Chinese auto industry has been remarkable.The number of auto manufacturers and auto parts manufacturers in China is also growing on a large scale.At present,the assembly methods of many companies are still mainly manual,and assembly operators are high participation groups in the assembly process.The quality problems and occupational diseases still occur frequently due to human error.In this paper,the transmission is used as the research object,and the man-machine ergonomics evaluation study of the gearbox assembly operation for DCT factory of G Company was carried out,in order to improve the man-machine-environment of the assembly operation,improve the assembly efficiency and reduce the occurrence of occupational diseases.The main research contents of this paper are as follows:(1)The ergonomics evaluation index system for assembly operations was established.The current ergonomics related standards and similar index systems was analyzed,under the guidance of the selection and construction principles of indicators,combined with the related factors that affect the comfort of workers' assembly work and the research background of this paper,the evaluation index framework was constructed.Based on the improved Delphi method,the initial index was selected and the ergonomics evaluation index system for the assembly operation was established.According to the relevant industrial standards,the evaluation method of individual indexes for ergonomics was studied,and the applicable evaluation methods for each index were given.Combined with field data collection of G Company and ergonomics,the operation flow and action of workers were decomposed,man-machine-environment was analyzed,relevant data were obtained and comfort index was obtained.It provided the basis for comprehensive evaluation of ergonomics in transmission assembly operations.(2)A grey multi-level fuzzy analytic hierarchy process evaluation model for ergonomics evaluation of assembly operations was established.On the basis of the evaluation system of multi-index work efficiency for the comfort of assembly operation,taking the assembly of transmission in G Company as an example,the grey correlation degree analysis method was used to determine the correlation degree among the indexes,and the fuzzy relation matrix was established.The weight of the index was determined in combination with the analytic hierarchy process.Finally,the two were combined fuzzily to establish a multi-level fuzzy synthesis model for the comfort of assembly operations,and the ergonomics were evaluated for the workers,machines and environments of variable shell assembly,and the combinedmodel was evaluated by using MATLAB software.The result of evaluation showed that the degree of comfort of current assembly work was the most closely related to "less comfortable",and this result was consistent with the actual investigation and investigation.Therefore,corresponding measures should be taken to improve human factors.(3)Based on the theory of ergonomics,an improvement plan was proposed.Through the analysis of ergonomic evaluation results,it could be seen that working posture was the factor that affected the weight of the assembly work comfort.Adding a weightlifter to carry the shell can shorten the shell transport distance to reduce the physical load.Based on the NIOSH lift equation,the improved postoperative posture reassessment will be conducted to compare the results of the on-site operation posture evaluation before and after the improvement.The results showed that the program had obvious effects: reducing the employee transport distance and ease Work fatigue,avoiding heavy loads for a long time,and improving assembly efficiency and operating comfort.