RU1784306C - Rolling mill cage - Google Patents

Abstract

Usage: in pipe production in the production of mountains of embossed pipes by longitudinal rolling. The essence of the invention: each of the work rolls is equipped with a device for applying solid briquetted grease mounted on a bed perpendicular to the longitudinal axis of the roll and the rolling axis. The device comprises a cylindrical body with a lid, the cavity of which is filled with tightly packed solid lubricant briquettes and connected to a water supply system. The body walls facing the roll are profiled under the stream. The lubricating device is stationary in the bed, and the ends of the housing are located above the top of the roll caliber with a clearance. In this case, the solid lubricant briquettes have the shape of the ends, which ensures their joining by a thorn connection, the spike of which faces the surface of the roll. A pipeline for supplying water to the device is connected to the upper end of the housing, from inside of which a cylindrical groove is made. 1 s.p., f-ly, 4 ill., 1 tab. with C

Description

. The invention relates to the field of metal forming, in particular to tube rolling equipment, and relates to stands equipped with devices for applying solid briquetted grease to rolls in the production of hot rolled pipes.

A known rolling mill stand is provided with a device for applying solid briquetted grease 1 comprising a cylinder whose piston is made of solid lubricant and the inner surface of the cylinder having protrusions forming a gap between the piston and the inner surface of the cylinder for supplying coolant.

The disadvantage of this stand is that in the device, the portion of the briquette located in the roll stream is not covered by the walls of the cylinder. As a result, a window is formed between the cylinder and the working surface of the roll, through which the remnants of the wiped briquettes are carried out by the roller, which reduces the duration of lubrication of the rollers, and this reduces their wear resistance. In this case, the number of transshipments increases, which leads to a decrease in mill productivity.

In addition, a disadvantage of this device is the connection of a coolant supply pipe to the cylinder head. In this case, the height of the lid increases, and this leads to a reduction in work

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whose briquette height, reduced the operating time of the rolls with grease, which, in turn, reduces the wear resistance of the rolls and leads to an increase in the number of transhipments. And this reduces the productivity of the mill.

The aim of the invention is to increase productivity by increasing the wear resistance of the rolls and simplifying the design.

Pobtavlein goal is achieved by the fact that the device for applying lubricant is installed in the frame stationary, and the ends of the walls of the housing are located above the top of the caliber of the roll with a gap while the briquettes of solid lubricant have a shape that ensures their joining, and the pipeline for supplying water is connected to the upper end of the housing which is made cylindrical groove. The jointing of the lubricant briquettes is provided by a spike connection, the spike of which is profiled under the stream and facing the surface of the roll.

The proposed technical solution differs from the known new set of features previously unknown.

Installing the device for applying grease to the bed is stationary, i.e. without dismantling and sub-adjustments when replacing rolls, simplifies the design and operation of the stands, reducing the time for their preparation for the next rolling. In addition, this makes it possible to connect the water supply pipe to the upper end of the cylinder body through the body of the bed, and this increases the working height of the briquette by reducing the height of the cylinder cover, which in turn increases the operating time of the lubricated rollers, increasing their wear resistance. Due to the increase in wear resistance, the number of transhipments decreases, which means that the productivity of the mill increases.

The location of the ends of the housing walls, profiled under the stream, above the top of the roll caliber with a gap, when lubricating briquettes ensure their joining, allows, on the one hand, to replace the rolls without first removing the housing walls from the roll handle, which simplifies the design and operation of the stands, and with connect the briquettes as a whole, which eliminates the need to have a enclosing body in the device and a flange sleeve connected to it via a key connection with an axial displacement controller tim housing, at the upper end of which is formed by a regulator external thread, since in this case no longer necessary to overlap the window between the walls of the housing and the surface vzlka.

After all, lubricant briquettes form a whole, i.e. there is nothing to fall out of the window.

Thus, the construction of the stand equipped with a device for applying solid briquetted grease is greatly simplified.

Due to the discontinuation of the axial displacement regulator - a structural element that changes the distance from the housing

Prior to the roll, the briquette height in the device will be the maximum possible and constant for all rolled pipes. This increases the operating time of the rolls with grease, which increases the wear resistance of the rolls and, as a result, increases the productivity of the mill.

Docking of lubricant briquettes and any other connection, the spike of which is profiled under the stream and facing the roll,

can significantly reduce the running-in time of the briquette to the brook surface of the roll, which helps to increase the wear resistance of the rolls, and ultimately the productivity of the mill.

Figure 1 shows a General view of the stands of the rolling mill with a briquette of grease in the initial position; figure 2 is a vertical section of the stand AA; in Fig.3 - part of the stand with a device for applying lubricant with the maximum

worn briquette; figure 4 - docked briquettes of lubricant in a vertical section of the stand.

The stand of the rolling mill comprises a bed 1 in which calibrated work rolls 2 are located. Each work roll 2 is provided with a device for applying solid briquetted grease 3. Each device contains a cylindrical body 4 with a groove 5 on the inner surface,

cover b and gasket 7. The cavity 8 of the housing 4 is filled with tightly packed solid lubricant briquettes 3 and connected to the cooling water supply system 9 through a common pipeline 10. Moreover, the connection

the pipeline 10 to the device is produced through the upper end of the housing 4 having a cylindrical groove 11. The walls 12 of the housing 1 facing the roll are profiled under the stream and located above the top of the caliber of the roll 2 with a gap, and the grease briquettes 3 are joined by means of a spike connection, consisting of nests 13 and spike 14, which is also profiled under a stream and facing the surface of the worker

roll 2. In this case, the tenon configuration fits into the minimum profile of the rolling roll.

A lubricating device is mounted on the bed 1 perpendicular to the longitudinal axis of the roll and the rolling axis and is rigidly fixed to it by bolts 15.

The proposed mill stand operates as follows.

After the assembled stand is installed 5 tons per ton on the base of the mill, the drives are connected to the work rolls, and the cooling water system to the lubrication devices. At the beginning of rolling, the rotation drive of the work rolls 10 2 and the supply of cooling water are turned on.

When the cooling water supply is turned on, it flows through the pipeline 10 and a cylindrical groove 11, which forms a gap with the lateral surface of the lubricant briquette 3, 15, enters the cavity 8 of the housings 5, where under the influence of the briquettes a force is created that ensures their pressing and moving against the rough surface of the work rolls 2 .When the work rolls 2 are rotated for 20 due to mechanical abrasion, a lubricant layer is applied to their surface.

Further, the lubricant is transferred to the deformation zone. At the same time, the cooling fluid flows through the groove 5 onto the 25 surface of the work rolls 2, where they are cooled by heat transfer and evaporation.

As the briquette of solid lubricant 3 is abraded, the cavity 30 of the housing 4 is released. When the briquette 3 completely leaves the cylindrical part of the housing 4, water begins to flow freely from it. In this case, the lubrication process on the rolling roll 2 is stopped, and further rolling of the pipes continues without lubrication of the rolls.

At the end of the rolling process, the water supply system is turned off and the work rolls 2 are stopped. Then the stands are dumped out of the mill.

Before the next rolling, devices are recharged. To do this, the lid 6 is removed, and then a new briquette is attached to the remainder of the old briquette. In this case, the briquette connection is spiked, after which the stands are installed in the mill line and the process is repeated.

With full wear, the vlokoz tranships them. Moreover, due to the gap 50 between the walls 12 of the housing 5 and the roll profile, the rolls are transshipped without dismantling the lubricating devices.

After the transfer of the rolls and the installation of the stands in the mill line, the process of rolling pipes 55 with the application of solid briquetted grease is repeated.

The proposed mill stand was tested under conditions of rolling seamless tubes of steel grade 30

102 x 6.0 mm, in hot condition, on the finishing group of the stands of the 18 stand reduction mill TPA 140-1 PNTZ. In the finishing stand of the rolling mill with work rolls on which a caliber with a width of 102 mm was cut, devices for applying solid briquetted grease were installed. Outlets for supplying cooling water were connected to the upper end of the housing of each of the devices from a common pipeline. Solid lubricant briquettes made of graphite electrodes of the GE brand by mechanical machining by cutting with a cross-section diameter of 102 mm and a height of 200 mm were installed in the device housings. The lower part of the briquette facing the roll was made in the form of a spike 48 mm high, having the shape of a truncated cone entering the profile of a brook, and an opening was made in the upper part of the briquette body for this spike. In this case, the spike and groove under it were made coaxially with the briquette. In addition, the ends of the casing walls, profiled under the stream, were located with a gap of 20 mm above the top of the roll profile. In this form, the crate was installed in the finishing group of the TPA 140 reduction mill. After installation, the cooling system was connected and the crate was ready for operation.

At the moment of starting the mill, the work rolls began to rotate and the coolant supply system was turned on, using industrial water under a pressure of 2 atm. The cooling water provided pressure and movement of the solid lubricant briquettes to the rough surface of the rolling rolls, as well as cooling of the rolling rolls during the rolling process. In the process of mechanical abrasion of the lubricant briquette during the rotation of the work rolls, it fell into the deformation zone, thereby separating the contact surfaces of the roll and the rolled pipe.

At the end of rolling, the water supply system was turned off and the work rolls stopped. Further, the stands were thrown out of the camp. Before the next rolling, briquettes were recharged. For this, a new one was docked to the remainder of the old briquette. After that, the test stand was again installed and the mill line and the process were repeated. Moreover, the integrity of the stacked briquettes was not broken, and the removal of the remnants of the old briquette was not observed.

During transshipment of the rolls, they were easily removed and put back in their initial position.

In order to determine the operational efficiency of the proposed mill stand in comparison with the prototype, the pipe rolling process in the proposed mill stand was carried out until the working part of the briquette h was completely abraded.

h - H - hi - h2, where H is the total briquette height;

hi is the height of the nest under the spike;

h2 is the distance from the roll flange to the device body (ha ™ 20 mm).

In the proposed stand, the height of the working part of the briquette was 132 mm.

At the same time, the rolling time and wear of the work rolls were recorded. Then, during the same time, the tubes were rolled 102 x V6.0 mm according to the prototype, in which the briquette height was designed for the maximum diameter of the rolled tubes, so that the briquetting height for this mill (assortment on the outer diameter 57 ... 102) was 22, 5 mm. In addition, the height of the briquette in the rTp type reduces the height of the lid, which in turn provides cooling water. The reduction in height is 25 mm. Thus, the briquette height in the prototype was 47.5 mm higher in the proposed solution and amounted to 84.5 mm. . The height of the roll profile was 50 mm.

During rolling, wear of the work rolls was recorded.

The wear resistance of the rolls was determined by the number of rolled tubes with an outer diameter size in the tolerance range determined by GOST.

The increase in productivity was found by increasing the main working time of the stand, which increased due to the reduction in the number of stops of the mill for transhipment.

Comparative data on the magnitude of the wear of the work rolls, wear resistance and performance are shown in the table, which shows that, compared with the prototype in the proposed stand:

1. The number of pipes rolled in the field of tolerance for the outer diameter on one set of work rolls is 28.6% more;

2. The number of transhipments per year decreased by 12;

3. Productivity increased by 887 tons per year.

Thus, the proposed design of the rolling stand in comparison with the prototype allows you to: increase productivity by 1-1.5%;

-increase the wear resistance of the rolls by 1.4 times;

-to simplify the design of the stand;

-increase the yield by 1.4-1.5 times.

Claims (2)

1. A cage of a rolling mill containing a bed, horizontal stream rolls, permanently mounted on the bed for each roll of the lubricating device in the form of a sealed cylindrical body with walls profiled under the stream facing the roll and a lid, the cavity of which is connected to the coolant supply system under pressure and filled with solid lubricant briquettes, characterized in that , with in order to increase productivity by increasing wear resistance, the ends of the housing walls are located above the top of the roll caliber with a gap relative to the radial plane of the shaft, and the ends of the solid lubricant briquettes have a shape that ensures their joining. 2. A cage according to claim 1, characterized in that the joint of the lubricant briquettes is made by a spike connection, the spike of which profiled under a stream and facing the surface of the roll. The results of the comparative test of the proposed mill stand and stand of the prototype Index The total volume of pipes rolled during the time i of abrasion of the working part of the briquette in the proposed stand, pcs. The working part of the briquette, mm Number of pipes rolled in the tolerance field, pcs Wear resistance of the rolls at the top of the caliber, mm / t The duration of the mill during pipe rolling in the tolerance field (without transshipment of rolls), hours, days Number of transshipments per year Estimated mill productivity, pcs .; t / year K5 The proposed mill stand The stand of the rolling mill according to the prototype 30000 84.5 20420 3.31,170; 7 . 30, 835200; 93542 , ", 827280; 92655 Gglf / 3/5 / Fig L