Summary: | 碩士 === 高雄醫學大學 === 職業安全衛生研究所 === 88 === Among the dangerous machinery equipment, overhead crane (hereinafter referred to as crane) is one of the largest quantity and widely used in factories. It has a complete and perfect arrangement on the aspect of hardware inspection, stipulations of laws and decrees as well as investigation, but it seldom probed into the areas of ergonomic and the symptoms of musculokeletal and the controlling systems, this study therefore aims at the aforesaid items in co-operation with qualified operators of the ironworks and practically proceed on investigation, making interview and on-site test. Result indicates more than 90% expressed it is a job required high-spirited attention in operating the crane, while investigating the causes for improper manipulation or terrifying happenings in proportion, lack of spiritual concentration by personnel ranks number one as 32.7%, and the machinery equipment, on the contrary, ranks the last as around 10%. And 86.7% operators represent they had the record of experiencing the symptoms of sour and ache of muscular and bone, the upper limbs with higher occurrence ratio, especially the palm and neck.
For controller manipulation, 61.3% personnel consider feeling a bit uncomfortable after using wired-controller, 8.7% for wireless-controller, if these two controllers existed simultaneously, about 76% personnel prefer using wireless-controller, only 13.3% prefer using wired-controller, the advantages of these two types of controller are: wired-controller has better control capability and low rate in failure, whereas the wireless- controller is more safer, convenient, comfortable and efficient for use, their disadvantages are just the reverse each other. Those personnel occurred with accident by using wired-controller expressed they could have avoided such happening by using wireless-controller instead; in order to lessen the burden of physical strength, spiritual stress of the operating personnel, thus reducing the occurrence of contingency, when selecting crane in a factory, a wireless-controller should be adopted in first priority, however, care must be taken against interference caused by frequency and the potential risks of operator in manipulating with a more relax manner. The average force exerted by imitating the controller with a grip simulator is 6.74kgs, which is higher than the average gripping force of 4.5kgs by domestic male, with a view of minimizing the occurrence of contingency and muscular and skeleton injury, so as to make improvement on the man-made harm, the specification of controller should be formulated, it is proposed to be holding a weight of 0.5-1.0 kg, and the model size should preferably be 20cm in length, 5-8 cm in width and 3cm in height, and the examination result found in the MSDs'' ergonomic checking list, for those with score higher than 5 points, upper limb accounted for 30% and back and lower limb accounted for 25%; the category of risk factor in the MSDs'' checking list shall be applicable in the manipulation of crane, but it is advisable to make modification and improvement on the risk factors, operating hours and scoring method before its application.
Poor environment of the occupational field and unhealthy physiological conditions could result to high percentage of manipulation error, reflecting a high demand for the characteristic of highly attention and manipulative operation in carrying out the task, moreover, it is essential to make improvement on the specification for the manipulative system, so as to enhance the security of the operator and to avoid the occurrence of man-made injury.
Key words: crane;MSDs
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