Design Of Respiratory Facemask And Mechanical Analysis Of Snap-Fit

Staff health and safety in the dust and harmful (toxic) gas environment have obtained more and more recognition in our country, but dust, harmful (toxic) gases on the human body is still a serious occupational hazard. The reason is not poor working conditions and infirmness personal protection awareness but the respiratory protective equipment quality, performance and wearing comfort. The research and development of Respiratory Protective Equipment in China is relatively weak, There is not enough mature technology, and incomplete design system in respiratory protective equipment. Therefore, there will have important theoretical and social significance if the prevention and protection of occupational dust dust health personnel have been enhanced with design theory, methods and structure of respiratory protective equipment studying.In this paper, a example is put, that is the self-absorption filter masks of respiratory protective mask, we put a new design concept through study it's design process and design method, and a design scheme improved have put through the analysis and comparison to the existing design scheme. The main work follows:The dead space volume of self-priming filter masks has been a controversial topic. In the paper through analyzing the characteristics of respiratory protective masks and technical requirements under "Respiratory Protective Equipment-Self-priming filter type particulate respirator" (GB 2626-2006) and "respiratory protection-self-absorption filter respirators" (GB2890-2009), the rough calculation of dead space volume have been proposed, which is the design reference of dead space volume.Inspiratory resistance and filtration efficiency of respiratory protective mask is always a pair of conflicting technical parameters, this method to increase filtrative rate by increase the thickness of the dust filter box will inevitably increase inspiratory resistance. In the paper through compared the characteristics of domestic and foreign products according to the characteristics and technical requirements of Self-priming filter protective mask, the second cavity structure and a related self-priming filter protective mask design have put. The structure can meet breathing method, separate respiratory and suction, solve the contradiction between filtration efficiency and expiratory resistance, more greatly reduce the expiratory resistance than similar protective mask.The assembly mechanics analysis to the snap connections between the protective mask and filter box according to the tightness requirement of self-priming filter mask, and the finite element numerical analysis on the snap have use the software of ABAQUS. The allowable deformation have been calculated according to the allowable stress of the snap connection, and then determine the maximum interference amount of snap, thus meeting the sealing requirements under ensuring Installation and removal. Meanwhile, the structure and size calculation of ring snaps have been proposed.