Preparation method for arc thread anchor bolt assembly for wind turbine

Abstract

The invention discloses a preparation method for an arc thread anchor bolt assembly for a wind turbine. A round steel rod is selected and rolled into a billet of the corresponding length in a fixed-length or double-length mode according to the need, the ultrasound+magnetic leakage combined damage detection is conducted on the billet, the heat treatment is conducted on the billet, the straighteningtreatment is conducted on the billet, and the surface oxide scale is removed; the vortex or magnetic powder damage detection treatment is conducted on the billet, and arc threads are rolled at the two ends of a workpiece through a thread rolling machine to obtain an anchor bolt; the round steel rod is selected and discharged to the stipulated size to be used as the billet by using a saw machine,forging, molding and punching are conducted on the billet, the end face and the inner hole are lathed by using a lathe, and the chamfering is conducted; and arc thread inner threads are formed by taping of a screw tap, and the heat treatment is conducted on the workpiece by using a vacuum furnace to obtain a nut. According to the preparation method for the arc thread anchor bolt, material removingbasically does not need, straightening and surface oxide skin removing are only needed, the diameter tolerance before anchor bolt thread rolling is controlled at + / -0.3mm, the material utilization rate is high, the production process is fewer, and the production cost is low.

Description

technical field [0001] The invention belongs to the technical field of wind power generating set tower bolt connection and anchor bolt connection, and in particular relates to a preparation method of an arc threaded anchor bolt assembly for a wind generating set. Background technique [0002] The prestressed wind turbine foundation is a new type of wind turbine foundation technology proposed by the United States, Canada and other countries in the early 21st century. It can effectively solve the problems of low construction efficiency, poor bending and overturning resistance, and adaptability to the application environment. It has excellent anti-slip, anti-overturning and environmental resistance properties. High-strength anchor bolts are the core components of prestressed fan foundations. Prestressed anchor bolt components include anchor bolts, nuts, etc., and are usually connected by threads. The thread profiles of existing threads can be divided into triangular threads, zi...

AI Technical Summary

Problems solved by technology

For the thread pair connected by metric thread, the diameter tolerance of the anchor bolt material before rolling the thread is generally required to be ±0.1mm, and the material utilization rate is low

In actual use, once the thread bumps, it will affect the installation and use of the normal threaded connection pair

Metric thread tooth type, the connection between bolts and nuts, anchor bolts and nuts is not smooth enough, which is prone to stress concentration. Under the action of high-frequency reciprocating dynamic loads such as wind turbines under normal working conditions, it is easy to break or loosen. Once a failure occurs, it is difficult to detect it in time through manual inspection and maintenance, and there are certain engineering hidden dangers

In addition, some domestic anchor bolt manufacturers adopt the heat treatment method of intermediate frequency quenching + intermediate frequency tempering. On the one hand, the end effect of anchor bolt heat treatment causes material waste, and on the other hand, the surface hardness of anchor bolts is too high, which is not conducive to later rolling processing.

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