Zero-torque anchor rod pre-tightening machine tool

Abstract

The invention discloses a zero-torque anchor rod pre-tightening machine tool amongin machine tools for increasing the pre-tightening force of anchor rods. The zero-torque anchor rod pre-tightening machine tool A product mainly comprises a hydraulic jack, a bearing sleeve, a connecting rod, a transition nut, a tail nut and a fastening nut structure. The zero-torque anchor rod pre-tightening machine tool disclosed by the invention is connected with an anchor rod by characterized in that the parts are utilized for forming the zero-torque machine tool for increasing the pre-tightening force of an anchor rod, the connecting rod and the transition nut are utilized for connecting the zero-torque anchor rod pre-tightening machine tool and the anchor rod; the hydraulic jack pushes the bearing sleeve to act on an anchor rod pallet,; simultaneously, the connecting rod is pulled to pre-tighten the anchor rod,; and finally, the fastening nut structure is used for fastening the anchor rod with high pre-tightening force. According to the zero-torque anchor rod pre-tightening machine tool disclosed by the invention, the problems that as an existing anchor rod only due to utilizes aation of the thread structure on the existing anchor rod, the increase of the pre-tightening force is low, the combined stress of the end part of the anchor rod is concentrated, the anchor rod is easily twisted in the fastening process, and the stressing of a roadway support is not uniform and the like are solved. The zero-torque anchor rod pre-tightening machine tool disclosed by the invention has the advantages of ultrahighthat the pre-tightening force is ultrahigh, zero torque is achieved, the alleviation of concentration of the combined stress at the root part of the thread is reduced and simplicity in the operation is simple, and is applicable to high pre-tightening force operation of the anchor rod or the fastening operation of the thread structure.

Description

technical field [0001] The invention relates to a zero-torque bolt pre-tightening tool among tools for increasing the pre-tightening force of the bolt. Background technique [0002] The bolt preload is the main indicator of roadway support strength, and increasing the bolt preload can effectively improve the overall strength of the support. The pre-tightening force of the existing bolt is mainly increased by increasing the torque of the bolt nut to increase the pre-tightening force. This method has no obvious effect on the increase of the pre-tightening force of the bolt. At the same time, it increases the compound stress concentration at the root of the bolt thread, which often results in a large torque force. The anchor rod is broken and damaged along the thread root. With the demand for high-stress roadway support and large-section roadway support in deep mining, the demand for high pre-tightening force of bolt support is increasing. Construction needs develop a special...

AI Technical Summary

Problems solved by technology

The pre-tightening force of the existing bolt is mainly increased by increasing the torque of the bolt nut to increase the pre-tightening force. This method has no obvious effect on the increase of the pre-tightening force of the bolt. At the same time, it increases the compound stress concentration at the root of the bolt thread, which often results in a large torque force. The anchor rod is broken and damaged along the root of the thread

With the demand for high-stress roadway support and large-section roadway support in deep mining, the demand for high pre-tightening force of bolt support is increasing. Construction needs develop a special tool to increase the pre-tightening force of the bolt to meet the construction needs of high-pre-tightening force anchors for high-strength support. It has the characteristics of reducing the composite stress concentration of anchor bolts, convenient construction, simple structure, common use with on-site construction equipment and convenient on-site construction management, etc.

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