The Study On Joint Property Of Eccentric Fittings Of Panel-type Furniture

Eccentric fittings is a kind of tighten fittings which is most widely used in panel-type furniture and its joint property directly influences the strength and rigidity of furniture and the quality of products. At present, there are some primal problems which seriously affect its manufacturing, application and exploitation: there is no national standard which leads to the specifications is not united; the quantity of eccentric fitting is uneven; the joint parameter is determined by experience and different kind of materials share the same joint parameter, which is lack of scientific basis; the basic research of theory is not emphasized. Therefore, this paper has studied such aspects as the characteristic of the drawing strength of inbuilt nut and direct assembling bolt,the mechanical characteristic of T-type and L-type joint and the improvement of designing eccentric fittings.The results are listed as follows:The utmost drawing strength of nylon inbuilt nut in particleboard(PB), medium density fiberboard (MDF) and bamboo glue-laminated panel increases with the increase ofαwhich is the ratio of diameters of the oriented hole and nylon inbuilt nut. The drawing strength which attained comparatively high value whenαis about 0.91 shows a trend of declining after it reached the maximum.The utmost drawing strength of direct assembling bolt in particleboard, medium density fiberboard and bamboo glue-laminated panel is about 23.1%, 39.1% and 36.3% bigger than that of nylon inbuilt nut respectively. It declines with the increase of times of direct assembling bolt knocked-down. But it can still reach that of nylon inbuilt nut after knocked-down 8 to 9 times.The breaking bending moment and rigid efficiency of 2-in-1 eccentric fittings are better than those of 3-in-1 eccentric fittings when they use the same mounting distance of eccentric house . The breaking bending moment and rigid efficiency of T-type joint are better than those of L-type joint. The influence degree of furniture material to breaking bending moment and rigid efficiency in bamboo glue-laminated panel is bigger than those in medium density fiberboard and particleboard orderly. With the increase of the mounting distance of eccentric house, the breaking bending moment increases, while the rigid efficiency increases obviously. The breaking bending moment and rigid efficiency decline when the mounting distance occurs minus warp, and they increase when the mounting distance occurs plus warp.In this paper, the assumption of designing eccentric fittings and the suggestion of founding guild among the companies of furniture hardware as quickly as possible have been put forward. Furthermore, the study on furniture hardware could be explored deeply with the support of the academic research institute, which is the basis of the establishment of national standard used in the fields of the manufacturing of eccentric fittings and the applied technology industry.