Technology for making strengthened anchor such as end cold-pressing

Abstract

The invention provides a processing method of a cold-pressed head and other strong bolts. It has a rod body on which an axial spiral rib is processed. The cold-rolled and hot-rolled anchor body base material is cold-pressed by using a cold-pressed head facility. The length is about 70-150 mm. The end of the one-way spiral anchor rod without longitudinal reinforcement is cold-pressed and rounded. It is processed into a cylindrical rod body that meets the technical requirements of thread rolling, and then the standard metric thread is rolled out through the thread rolling process. During installation and construction, it can confiscate and stir the anchoring agent, the propulsion and rotation resistance is small, the rod body has good grip and wrapping force, high strength, and the transfer effect of the anchoring force and bearing capacity is improved. The force can be transmitted to the rod body to increase the bearing strength. The material of the rod body is saved, and the cost is low. The anchor rod processing method of the present invention has the following advantages: it can reduce the material loss and strength loss during the processing of the anchor rod parent rod, make the strength of the end reach about 95% of the tensile strength of the anchor rod parent material, and basically realize the anchor rod etc. Strong, eliminates stress concentration and brittle fracture, and improves the overall strength of the bolt by 15-25%.

Description

technical field [0001] The invention relates to mining support technology for mine resources, and relates to a processing method for strong bolts such as cold pressure heads used for bolt support in underground mining roadways. Background technique [0002] The existing anchor rods generally have one-way left-handed ribs and no longitudinal ribs. After many improvements, good support effects have been achieved. However, in practice, it is found that the existing anchor rods still have many shortcomings: when fully anchored, The effect of confiscating and stirring the anchoring agent is not good, the grip force of the rod body is slightly poor, the pitch, height, angle, and weight of the rib are too large, the rod body is not round, and the resistance to propulsion and rotation of the anchor rod is easy to be large, and the force is easily transmitted to the rib. Frequently passing the anchor rod through the anchoring agent reduces the stirring effect and causes poor anchorin...

AI Technical Summary

Problems solved by technology

[0002] The existing anchor rods generally have one-way left-handed ribs and no longitudinal ribs. After many improvements, good support effects have been achieved. However, in practice, it is found that the existing anchor rods still have many shortcomings: when fully anchored, The effect of confiscating and stirring the anchoring agent is not good, the grip force of the rod body is slightly poor, the pitch, height, angle, and weight of the rib are too large, the rod body is not round, and the resistance to propulsion and rotation of the anchor rod is easy to be large, and the force is easily transmitted to the rib. Frequently make the anchor rod pass through the anchoring agent to reduce the stirring effect and cause poor anchoring force

This processing method reduces the effective cross-sectional area of ​​the threaded section, and then loses 15-25% of the tensile strength of the base material of the anchor rod, and causes the anchor rod to form stress concentration and fail first during use.

2. The disadvantage of thermal processing is that it produces iron oxide scale, thermal expansion and cold contraction cause extension, cylindrical body is thinner than the base metal rod body, and the size error is too large, so it is difficult to achieve the strength of the anchor rod body.

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