Online length measuring method for thermal-state steel pipe

Abstract

The invention provides an online length measuring method for a thermal-state steel pipe. The online length measuring method is characterized in that an optical fiber type hot metal detector with response time being 5ms is separately above each of a roller way with a distance of 1.5-2m from an outlet of a tandem mill and a roller way with a distance of 12-14m from the outlet of the tandem mill. After the thermal-state steel pipe is rolled by the tandem mill, the head part of the thermal-state steel pipe firstly passes through the first hot meal detector with a shorter distance, the first hot metal detector is used for converting a detected value into an electric signal which is input into a PLC, and the PLC starts timing; when the head part of the thermal-state steel pipe passes through the second hot metal detector, the PLC reads a first timing interval; and when the tail end of the steel pipe deviates from the first hot metal detector, timing of PLC is ended, and the PLC calculates length Y of the steel pipe by setting procedures. The online length measuring method is simple and reliable, can completely meet technological requirements, can operate on an HMI of a computer and can display effective steel pipe length, wherein detected length is 12-35m, and detection errors are +/-10mm; and the length of the steel pipe is detected, so that tandem-rolling regulating precision is improved and unit yield is increased.

Description

Technical field: [0001] The invention belongs to the technical field of automatic length detection, and in particular relates to a method for online detection of the length of a hot steel pipe. Background technique: [0002] In the production of seamless steel pipes, it is of great significance to measure the length of the blank pipe at the exit of continuous rolling. By measuring the length of the steel pipe, the production operation can be easily adjusted according to the length of the continuous rolling roll gap to ensure product quality. [0003] Steel pipe length measurement is generally realized by laser. Due to high investment cost, complex technology, difficult maintenance, and short service life, it is rarely used on site. Therefore, the adjustment accuracy of the continuous rolling mill is low, the production adjustment time is long, and the yield and quality of the production line are reduced. Invention content: [0004] The purpose of the present invention is ...

AI Technical Summary

Problems solved by technology

[0003] Steel pipe length measurement is generally realized by laser. Due to high investment cost, complex technology, difficult maintenance, and short service life, it is rarely used on site.

As a result, the adjustment accuracy of the continuous rolling mill is low, the production adjustment time is long, and the yield and quality of the production line are reduced.

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