Three-roll plug steadier

Abstract

The invention discloses a three-roll plug steadier, which comprises three corresponding rolls, three swing rods and three sets of linkage mechanisms. The output end of any swing rod is in pivoted connection with one corresponding roll, the input end of any swing rod is in fixed connection with one end of an output rod of one corresponding linkage mechanism and hinged on the fixed rotation shaft of the output rod, the input rods of the three linkage mechanisms share the same fixed rotation shaft and are in linkage, the transmission ratios of any two linkage mechanisms are 1, and the transmission ratio of the other linkage mechanism is -1 plus or minus 0.5%. The three-roll plug steadier provided by the invention can improve equipment utilization rate and service life and lower production costs while greatly improving production quality of seamless steel tubes.

Description

technical field [0001] The invention relates to rolling equipment for the production of seamless steel pipes, in particular to a three-roller core-holding device in the background of a piercing machine in the production of seamless steel pipes. Background technique [0002] The three-roller core-holding device is one of the key equipment on the seamless steel pipe production line. There are several three-roller core-holding devices on the background of the piercing machine or the front desk of the cross-rolling pipe mill. Its function is to hold the ejector rod, Mandrel and capillary, so that the center line always coincides with the rolling line. Therefore, whether the structure of the three-roller core-holding device is reasonable directly affects the production quality of seamless steel pipe products. [0003] The structure of existing three-roller core-holding device 1 is as follows: figure 1 As shown, it includes three holding rollers 11 , three swing bars 12 and three...

AI Technical Summary

Problems solved by technology

But in the process of actually adjusting the holding rollers 11, since each holding roller 11 is connected by different swing rods 12 and link mechanisms 13, the transmission ratio of each link mechanism 13 is different, and the input rod 132 of the link mechanism 13 During linkage, the output rod 131 cannot guarantee the linkage, so the angular displacement of each holding roller 11 after being transmitted by the swing rod 12 is different, which will lead to deviations in the center coincidence degree of the three hugging rollers 11 after adjustment, and the center coincidence degree The deviation increases with the increase of the opening of the holding roller 11, such as figure 2 shown

Generally, the opening range is 140-790 mm. In the prior art, when the opening is small (less than 600 mm), the center coincidence is better, but when the opening is large (greater than 600 mm), the center coincidence is very poor.

Moreover, even when th

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