SU1260051A1 - Cooled mandrel for continuous rolling mill - Google Patents

Description

The invention relates to pipe production, in particular to a tool for a continuous pipe mill with a retained mandrel.

The aim of the invention is to reduce the flow rate of coolant and regulate its delivery.

Figure 1 shows the mandrel, a general view, figure 2 - the same, in the process of work.

The cooled mandrel consists of a rod I with an internal cavity 2 and holes 3 in the wall, working rings 4 fixed on it and rigidly attached inside bushings 5 having a flange 6 and an axial channel 7 for supplying coolant and disks 8 that have axial pressure the recess 9 under the end of the sleeve and the longitudinal channels 10 for supplying coolant.

Cooled mandrel works as follows.

The cooling fluid flows under pressure into the cavity 2. The core 1 of the mandrel. Through the longitudinal channels 10 in the Disk 8, the cooling liquid enters the holes 3 radially placed in the walls of the hollow rod, through which it sprinkles onto the working ring A corresponding to the first stand of the mill. After the tube has been gripped by the rollers of the first stand, due to the elastic deformation of the mandrel bar, a gap is formed between the end of the sleeve 5 and the recess 9 of the disk 8 through which the cooling fluid flows through the axial channel 7 of the sleeve and the longitudinal channels 10 of the next disk enters the holes 3 that feed the lubricant - coolant on the working ring A, corresponding to the second stand.

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When the pipe is seized by the rollers of the second stand, coolant is supplied in the same way to the working ring, corresponding to: the third stand, etc.

At that, as the subsequent cages fill the metal, the axial force on the mandrel rod increases, which leads to the increase in the gaps between the bushings and disks in the first cages due to the elastic deformation of the rod and the supply of coolant to the cavity.

As the pipe leaves the mill stand, the supply of coolant decreases, and after the pipe is removed from the pipe, the last fly is supplied to the first working ring, preparing it to receive the following pipe.

Preliminary calculations made for the projected continuous 5-cell mill with a retained mandrel showed that with a mandrel bar diameter of 150 mm, a wall thickness of 40 mm, an axial rolling force in one stand of 60–75 tons and the distance between the mount bushings and a disk of 750 mm gap formed by the elastic deformation of the rod, is 0.2-0.25 mm.

With a cavity diameter of 50 mm and a coolant pressure of 20 atm, about 35 l / s is supplied to the working rings of the mandrel, which is quite enough for reliable lubrication and cooling of the working rings and mandrel bar.

The mandrel allows you to adjust the supply of coolant in the process of rolling the pipe in a continuous mill, which reduces its consumption by DOG-40% and increases the service life of the cutting tool.

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Claims (1)

COOLED CORRECTION OF A CONTINUOUS MILL, containing a hollow core with channels for supplying cooler ⁴ and holes in the walls and working rings fixed to it at intervals, characterized in that, in order to reduce consumption. cutting fluid and regulating its supply, it is equipped with bushings located in the cavity of the shaft with an axial channel having flanges rigidly attached to the rod coaxially to each working ring, and discs, · covering the profile end of each sleeve with an axial recess attached to the rod at a distance from the axis of fastening of the sleeve flange, comprising 0.8-0.9 of the interval between the working rings, and having longitudinal channels connecting the cavity inside the rod between each sleeve and the disk with the cavity between the disk and the subsequent conductive sleeve. SU ,, 1260051