RU2288796C2 - Safety apparatus for stand of rolling mill or tube welding mill - Google Patents

Abstract

FIELD: plastic working of metals, namely apparatuses for protecting rolls against overloads in rolling or welding stands of rolling or tube welding mills.

SUBSTANCE: safety apparatus includes safety member arranged between roll chock and screw down mechanism. Said safety member includes upper flange and thrust bearing engaged with screw down mechanism. According to invention lower flange of safety member includes cylindrical recess where unit for measuring efforts is placed. Mean portion of safety member is barrel-shaped and it is provided with through cavity and oval vertical windows arranged uniformly along barrel-shaped surface.

EFFECT: elimination of idle periods and breakage of manufacturing equipment, improved design of safety apparatus that may be loaded by compression and bending efforts, enlarged manufacturing possibilities of mill, lowered labor consumption for making simplified-operation safety apparatus.

2 dwg

Description

The invention relates to the field of metal forming and can be used in working and welding stands of rolling pipe welding mills to protect work rolls from overload.

In stands of pipe welding mills, the following types of safety devices are currently mostly used:

- on aggregates of a small assortment of pipes (⌀ 6-114 mm) in the form of a set of cylindrical compression springs of different diameters according to OST 247.64.04-78;

- on aggregates of an average pipe assortment (⌀ 114-203 mm) in the form of a cup spring plate according to GOST 3057-79;

- on aggregates for pipes (⌀203-530 mm) in the form of pneumohydraulic pressure trains by analogy with the design described in ed. testimonial. No. 301574, cl. G 01 L 1/02, claimed 04/26/70, publ. 04/21/71

The above types of safety devices have a common drawback - high complexity and manufacturing costs and narrow technological capabilities.

Besides:

- compression springs for a working force of more than 5 tons require significant dimensions for their placement;

- Belleville springs have insufficient service life and large deviations (+ 20%) in effort and magnitude of deformations;

- Mesdozas are practically inoperative due to the small volume of the working medium and natural leaks.

A safety device of a rolling stand of repeated action is known (ed. Certificate of the USSR No. 601060, class B 21 B 33/00, decl. 02.06.76, publ. 05.04.78), including located between the pillows and their pressure devices wedge mechanisms and compression springs preloaded by setscrews.

The disadvantage of this device is that in its composition and design it does not provide a reliable limitation of overloads in the stands, and the overloads exceed the permissible ones more, the longer the safety device travels. And this move should be as large as possible, especially for hot rolling mills, characterized by large reductions.

In addition, the use of a wedge mechanism causes additional spacer efforts in the stand, the set screws require periodic monitoring and tightening, which leads to an increase in mill downtime.

Of the known closest in technical essence is the safety device of the mill stand described in ed. testimonial. USSR No. 1424893, class At 21 At 33/00, stated 01/30/87, publ. 09/23/88

This device comprises a safety element located between the roll cushion and the pressure screw, made in the form of a cup with a weakening groove, an upper flange, a bottom and a thrust plate interacting with the pressure screw, and a support ring located between the upper roll cushion and the glass flange. The device is equipped with means for fixing the bottom relative to the end face of the support ring facing the pillow and means for adjusting the stiffness of the contact zone between the end face of the support ring and the flange of the safety glass. Moreover, the means for adjusting the stiffness of the contact zone between the end face of the support ring and the cup flange is made in the form of a set of washers having different thicknesses and different outer diameters, the washers being made of a material with an elastic modulus less than the elastic modulus of the materials of the cup and the support ring.

The main disadvantage of this safety device is the complexity of its design. At the same time, materials with different modulus of elasticity are used for the glass and support ring. At a working load, its main elements work in tension-compression, which, due to insignificant deformations, does not allow using the device in a wide range of acting forces on the rolls.

Rolling and tube welding mills equipped with these devices that do not have the means to measure the forces on the rolls and the ability to stop the units in the event of unacceptable dynamic loads or accidents will have frequent downtime or even breakdown of technological equipment due to destruction of the glasses.

The objective of the present invention is to provide a safety device for rolling mill or tube welding mills with wider technological capabilities, allowing it to be loaded with both compressive and bending stresses in a wide range of acting forces on the rolls, as well as eliminate downtime and breakdowns of technological equipment in the event of unacceptable dynamic overloads .

The next objective of the present invention is to simplify its design and reduce the complexity and cost of its manufacture and operation.

The task is achieved in that the safety device of the stand of a rolling or pipe welding mill, comprising a safety element located between the roll cushion and the pressure screw with the upper flange and the thrust bearing interacting with the pressure screw, according to the invention is equipped with a force measuring device on the roll installed in a cylindrical recess made for it in the lower flange mounted on the safety element, the middle part of which is made barrel-shaped with a through cavity ew and oval vertical windows evenly spaced on a barrel-shaped surface.

Such a constructive implementation of the safety device of the mill stand or pipe welding mills will allow to expand technological capabilities, eliminate breakdowns and downtime of technological equipment in the event of unacceptable dynamic overloads.

This is achieved by performing the middle part of the safety element barrel-shaped with oval vertical windows, while the sizes of the safety devices in terms of working effort are easily obtained by changing the size of the parts of the safety element, the number of oval vertical windows and replacing one steel grade with another or changing the heat treatment (changes mechanical properties of the material).

In addition, by providing the device with a means of measuring the force on the roll and the possibility of disconnecting the stands drives at the time of the occurrence of unacceptable dynamic loads or accidents, downtime and breakdown of technological equipment are completely eliminated.

The proposed design of the safety device is much simpler, has less complexity and the cost of its manufacture and operation.

To explain the invention, a specific embodiment of the invention is provided below with reference to the accompanying drawings, in which:

figure 1 shows the safety device cages rolling or pipe welding mills, General view;

figure 2 is a section aa in figure 1.

The safety device of the stand of a rolling or tube welding mill comprises a safety element 3 located between the roll cushion 1 and the pressure screw 2 with the upper and lower flanges 4, 5. A cylindrical recess 6 is made in the upper flange 4 to secure the thrust bearing 7, which interacts with the spherical end 8 of the pressure screw 2 A cylindrical recess 9 is made in the lower flange 5, in which a force measuring means 10 is mounted, the lower part of which is located in the cylindrical recess 11 of the roll pillow 1. The middle part 12 of the safety element 3 is made barrel-shaped with a through cavity. The height of the middle part "H", its maximum outer diameter "D" is greater than the diameter of the flanges by 2V, where B is the size of the protruding middle barrel-shaped part of the safety element. The internal cavity also has a barrel-shaped shape. The wall thickness "δ" of the middle barrel-shaped part of the safety element 3 is the same over the entire surface. To the entire height "H" in the middle barrel-shaped part of the safety element 3 there are oval vertical windows 13 arranged uniformly over the entire surface.

Depending on the range of working forces on the roll, the safety element 3 is made of steel with a tensile strength of 700-1600 N / mm ² .

The device operates as follows.

Before starting a rolling or tube-welding mill for the production of the current assortment, the distance between the rolls is set, according to the calibration, using the pressure screw drives (not shown), and the maximum force on the roll (not shown) is set according to calibration.

The sizes of the safety element according to the magnitude of the working forces are determined by changing the size of the parts of the safety element, the number of oval vertical windows and replacing with another steel grade or changing the heat treatment.

Moreover, both the distance between the rolls and the forces on the roll should be the same on both sides of the rolls.

After setting up all the stands, test rolling or molding and welding of the tube stock is carried out, followed by checking its dimensions, and for the tube stock, the quality of the welded joint.

Upon receipt of high-quality rolled products or welded pipes, a rolling mill or pipe welding mill for the production of this assortment is included.

In the event of unacceptable dynamic forces on the roll (or crashes) in the stands (or cages), as well as a decrease in this force below the minimum permissible value, a means of measuring forces 10 on the roll will turn off the stands (stands) drives. The mill operator in this case is an active participant in the technological process.

At any time, he can see the current operating force on each cushion of workers or pipe welding stands on the remote control board, that is, indirectly monitor the quality of the products.

The proposed safety device of the stand of rolling or pipe welding mills, in comparison with the known ones, will expand technological capabilities due to its design features, allowing it to be loaded with both compressive and bending stresses, and will also eliminate downtime and breakdowns of technological equipment in the event of unacceptable dynamic overloads.

The device also allows to reduce the complexity and cost of its manufacture and operation.

Claims (1)

The safety device of the stand of a rolling or tube welding mill, comprising a safety element located between the roll cushion and the pressure screw with an upper flange and a thrust bearing interacting with the pressure screw, characterized in that it is equipped with a force measuring means on the roll installed in a cylindrical recess made for it in a lower flange mounted on a safety element, the middle part of which is made barrel-shaped with a through cavity and oval vertical windows, aspolozhennymi uniformly over the barrel surface.

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