Three-roller tube-rolling machine with two threading-bar mode

Abstract

The invention discloses a three roll pipe mill adopting two methods of threading-core rod, which belongs to the production equipment of seamless steel tube. The invention solves a technical problem of slow rolling resulting from on-line threading rod or unstable rolling quality of a thin-wall tube resulting from off-line threading rod adopted by the existing three roll pipe mill with a full floating mandrel. The invention comprises the main body of three roll pipe mill, a main motor (6), a mill background (7), an on-line rod-threading device (4) and an off-line rod-threading device (3) arranged on a mill foreground. A traverse mechanism is arranged between the on-line rod-threading device (4) and the off-line rod-threading device (3) and used for realizing parallel movement between two work stations of a pre-rolled steel pipe adopting on-line threading-core rod and the pre-rolled steel pipe adopting off-line threading-core rod. The invention has the beneficial effect that both the on-line rod-threading device and the off-line rod-threading device are arranged. One of threading-core methods can be adopted according to product and production process. As a result, rolling quality can be ensured and rolling speed can be improved.

Description

technical field [0001] The invention relates to a seamless steel pipe production equipment, in particular to a three-roll pipe mill in the seamless steel pipe production equipment. Background technique [0002] At present, the full-floating mandrel three-roll pipe mill can be roughly divided into two types according to the way of rolling the steel pipe through the mandrel. One is the three-roll pipe mill that adopts the method of threading the rod outside the rolling center line, that is, pre-piercing. The advantage of this kind of pipe rolling machine is that the rolling rhythm is fast, and the disadvantage is that for thin-walled pipes, the pre-piercing method will cool the steel pipe, thereby affecting the rolling quality. The other is to thread the rod on the rolling center line, that is, to thread the rod online. The advantage of this pipe rolling machine is that the rolling quality is guaranteed, but the disadvantage is that the rolling rhythm is slow and the productio...

AI Technical Summary

Problems solved by technology

[0003] The invention solves the technical problem that the rolling rhythm of the existing full-floating mandrel three-roll pipe mill is slow when the rod is threaded online or the rolling quality of the thin-walled pipe is unstable when the rod is threaded outside the line.

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