Self-tangency broaching anchor bolt

Abstract

The invention discloses a self-tangency broaching anchor bolt comprising a sleeve, wherein the lower end of the sleeve is provided with an expansion structure, the upper end of the sleeve is provided with a clamp groove which is embedded with an installing tool, the expansion structure comprises a plurality of expansion pieces, the lower end of the expansion structure is provided with a milling structure, the milling structure comprises a plurality of cutter teeth which are peripherally and evenly distributed around the axis of the sleeve, one sides, which face to a sleeve rotating direction, of the cutter teeth are provided with cutting edges, the cutting edges are slantwise arranged opposite to the end face of the sleeve, and the bottom ends of the cutting edges are convex towards the sleeve rotating direction; and the cutter teeth are directly machined by the lower end of the expansion structure, a hard material wear layer is arranged on the working faces of the cutter teeth or the cutting edges are provided with hard alloy blocks, or the cutter teeth are wholly formed by the hard alloy and are fixed at the lower end of the expansion structure. The self-tangency broaching anchor bolt uses the milling principle of a milling cutter, so that the cutting edges are matched with the hard alloy or hard material wear layer, therefore, the transverse and lengthways milling performance can be greatly improved when the anchor bolt is expanded.

Description

technical field [0001] The invention relates to a self-cutting reaming anchor bolt, in particular to an expansion anchor bolt which automatically reams holes during the expansion process and can not only mill concrete but also metal materials in the concrete. Background technique [0002] When the existing post-reaming anchor bolt application technology is installed, the drill bit is used to drill holes on the concrete substrate, and then the bottom end is reamed with a special reaming drill bit. After the head of the anchor bolt expands, it forms a lock with the reaming space. Solid structure, no expansion stress. However, in actual reaming, steel bars are often encountered in concrete. The current design of reaming drills is only for cutting and reaming concrete substrates. The cutting performance of steel bars is very poor, and it is impossible to ream concrete with steel bars. At the same time, the reaming drill bit has defects such as cumbersome operation, inaccurate p...

AI Technical Summary

Problems solved by technology

[0005] However, the milling function of the above two milling structures of self-cutting and reaming anchor bolts is still not good enough. It is a vertical relationship, which causes the anchor bolt structure itself to have a small cutting force on the material, which is an effect with the passivation or chipping of the milling cutter. It is difficult to apply effective milling force to the steel bar during the milling process; the second reason is that the anchor bolt expands In the later period, because the distance between cracks 1-4 becomes larger, the milling continuity of each cutter tooth decreases. As the expansion progresses, the milling force becomes smaller and the milling process becomes slower and slower. In fact, it is difficult to achieve a stable expansion degree. ;Anchor bolts using cemented carbide blocks, because the gap between the alloy blocks is large, the milling continuity is not high, the milling performance of the metal material is also not ideal, and the alloy block will fall off during the milling process

[0006]Tubular milling structures are also common in the tubular drill bits of water drilling rigs, and the front end also has a milling structure. The gap is formed, but the tubular drill bit does not expand horizontally when it is deep in the longitudinal direction, that is, it only mills longitudinally and does not mill horizontally. Good milling performance, but poor milling performance for tough metal materials

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