Back bolt and connection structure

Abstract

The invention provides a back bolt and a connection structure. The back bolt comprises an anchor pole and an expansion member. The expansion member has a cylinder main body and a plurality of expansion positions at one end of the cylinder main body, the external diameter of each expansion position is the same as that of the cylinder main body, each expansion position has a protruding portion, and the protruding portion is used as a bearing portion cooperating with a cone position of an bottom-expanded hole in a plate after the expansion position expands. The plurality of expansion portions at one end of the cylinder main body form an expansion segment, and the inner side of the expansion segment form a thinning position used for easily expanding and bending. The back bolt can well match a bottom-expanded hole, the anti-rotation and limiting measure does not influence cooperation between the back bolt and the bottom-expanded hole, and the cooperation having the good matching effect can be kept, permanent whole connection can be achieved, and the stress of an expansion position can be reduced to the minimum or zero. A never loosen connection structure can be formed using the back bolt, the connection structure can resist strong earthquake, and start-stop impact of a subway, and welding reinforcement is needless.

Description

technical field [0001] The invention relates to a back bolt, which is used for the decoration of dry-hanging boards of various buildings. It is anchored and connected through the back of the board, so it is called "back bolt". It is especially suitable for the use of dry-hanging curtain walls such as subway stations, ceramic plates, glass-ceramics, etc., and can also be used in other building structure connection fields. The invention also relates to connection structures utilizing such back bolts. Background technique [0002] At present, the cone screw load-bearing back bolts used in the curtain wall of the building envelope mainly consist of three types: "one-piece cylindrical expansion ring, disc-shaped expansion element, and disc-shaped set point force-bearing expansion element". [0003] The first type adopts the conjoined cylindrical expansion type. Although the market share ranks first, it has the function of the flexible layer to balance the force on the four expan...

AI Technical Summary

Problems solved by technology

[0003] The first type adopts the conjoined cylindrical expansion type. Although the market share ranks first, it has the function of the flexible layer to balance the force on the four expansion expansion elements. However, the anatomical study of its slices shows that its defects are reflected in the expansion. The protruding arc-shaped rings of the four expansion elements match only 40-50% with the conical surface of the expanded bottom hole of the plate; and because the outer diameter of the expansion section is smaller than the outer diameter of the conjoined cylinder, the protruding arc-shaped rings of the four expansion elements will be under load. When the negative wind pressure tensile force and the suspension tensile force are relatively large, the side recess whose outer diameter of the expansion section is smaller than the outer diameter of the conjoined cylinder bends toward the hole wall, so that the protruding arc surface pulls and slides out of the conical surface of the expanded bottom hole of the plate Possibly; there is also a very high manufacturing cost of the one-piece cylindrical expansion part, which is complicated in technology. It needs to use stainless steel seamless pipes that are 1.6 times more expensive than stainless steel wire rods. It is completed through complicated cutting and processing, and the waste of materials is also quite serious. Larger areas for further improvement

[0004] The second type uses a disc-shaped expansion element, which is stamped from a stainless steel plate. After expansion, it is in a sheet shape and cannot match the conical surface of the bottom expansion hole of the plate. In addition, the cross-section of the metal expansion element is not compatible with the brittle stone and porcelain plate. Direct load bearing, especially high brittle porcelain plates, glass-ceramics, glass, etc. are more insufficient

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