Friction constant-resistance grading yielding anchor rod

Abstract

The invention relates to a friction constant-resistance grading yielding anchor rod. In order to overcome the defects in the prior art, the friction constant-resistance grading yielding anchor rod comprises an arch-shaped supporting body, a fastening nut, an anchor rod body, a screw rod and a rotating cylinder, wherein one end of the screw rod is directly, coaxially and fixedly connected with theouter end of the rotating cylinder and is integrally formed with the outer end of the rotating cylinder; an external thread is arranged at the outer end of the anchor rod body; the rotating cylinder is rotationally arranged at the outer end of the anchor rod body in a sleeving manner and is in threaded fit with the outer end of the anchor rod body, and the lead angle of the thread is 60-65 degrees; the main body of the fastening nut is frustum-shaped, and the outer diameter of the small end of the fastening nut is smaller than the diameter of a through hole in a bulge and the diameter of the through hole is smaller than the outer diameter of the large end of the fastening nut; and the arch-shaped supporting body at the periphery of the bulge is pressed on surrounding rock at the peripheryof a matched anchor hole; and the small end of the arch-shaped supporting body extends outwards to form a cylindrical section. The friction constant-resistance grading yielding anchor rod has the advantages of convenience in processing and mounting, can provide constant anchoring force at the beginning, can automatically and gradually improve the anchoring force within a certain range when the load is increased, and is widely applied to various mines.

Description

technical field [0001] The invention relates to a frictional constant resistance graded yielding anchor rod. Background technique [0002] At present, in coal mines and metal mines that have entered deep mining, due to the large buried depth of the roadway and the large in-situ stress in the roadway, a certain amount of uncontrollable deformation will still occur after the roadway is supported by ordinary bolts, and then the surrounding rock will gradually enter Stable state; this requires the bolt to have the ability to give way in the initial stage of roadway support, so that the roadway can be deformed appropriately to release the elastic energy accumulated in the surrounding rock, which requires the bolt to have the function of giving way. [0003] The yielding device of the traditional yielding bolt often adopts the yielding ring or the yielding tube. After the yielding ring is activated, the effective support length of the bolt is slightly longer than before the yieldi...

AI Technical Summary

Problems solved by technology

The present invention has good supporting effect and high bearing capacity, but the structure is still relatively complicated, and it is necessary to weld the piston on the anchor rod (ie the second anchor rod 2-1 described in the patent), assemble steel balls and other parts, install It is cumbersome, and when the constant resistance extrusion friction sleeve is pressed, it is deformed under pressure, the deformation state is different, and the force applied to the anchor is different, it is difficult to achieve real constant resistance, and its deformation is not elastic, not It is reversible, if there is a rupture or leakage of steel balls, the entire anchor will fail

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