DE2943240A1 - PILGRIMAGE ROLL CALIBRATION - Google Patents

Description

The invention relates to a pilger roll calibration for optimizing the roll utilization.

As is known, the circumference of the roller is used in pilger rollers divided into the working area and the empty caliber. The working area of the roller consists of:

Reducing cone (mouth)
Polishing caliber
Outlet cone (outlet),

those about caliber depths with the associated angles or routes can be defined.

The pilger roller calibrations known today have, as FIG. 1 shows, a total working angle of 180 to 210 degrees with proportions of 48-54% for the mouth, 30-36% for the polishing caliber and 12-18 % for the outlet. The corresponding degrees of angle of the roller circumference depend on the total angle that the working length of the rollers assumes.

The wear of the pilger rollers occurs most strongly in the mouth, depending on the running time - in the point of application "A" between hollow block and rollers - on. This point determines the amount required for mechanical post-processing and thus the number of possible roller uses.

To avoid great post-processing depths, it has been suggested that to move the Α-point in the direction of the working caliber, since then turning with less Can decrease in diameter. However, this measure means that the area of the spout is far in

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Direction of the empty caliber is shifted and there because of the strong opening of the empty caliber the required Roll material is missing in order to realize the desired curve function for the exit cone can. If the exit cone is too steep and therefore short, the rollers will loosen quickly Pipe. The roller pressure that is still fully applied acts on an area that is too small. As a result of too high Surface pressure, this leads to damage to the pipe that exceeds the permissible tolerance limit and lead to higher failure rates.

Another proposal provides for the outlet cone to be designed as a reducing roller cone (DE-PS 545 843). This design is said to have the advantage that after the first cone has worn out, the rollers can be easily removed Are ready for use again without reworking. The practical use of this proposal has the following Disadvantage:

- The curves for the reduced cone and the outlet cone show because of their different tasks a significantly different course.

- The steeper course of the mouth curve leads to the conversion of the outlet cone into a reducing cone, that the rollers detach too quickly from the pipe and the above-mentioned damage to the pipe occurs.

- During the necessary post-machining, the working area of the rollers is shifted in the direction Empty caliber. In this area, however, there is no appropriate roller material to achieve the desired groove shape to be able to.

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294324Q

It is generally known that stronger stress cracks (also Called fire cracks or water cracks). When the outlet is converted into a second mouth appear this damage is offset again by approx. 180 degrees. The roll core cross-section is thereby additionally weakened. This weakening is further increased by the notch effect. To make matters worse, that the maximum of the rolling force occurs in the area of the cross-sectional weakening.

The weakening of the roll cross-section leads to frequent breaks and thus to economic disadvantages.

It is the object of the invention to create a calibration with which it is possible to significantly improve a calibration To achieve the degree of utilization of the pilger rollers without negative effects on the pipe quality.

To solve this problem, a pilger roller calibration is proposed as described in the claim is.

The calibration according to the invention is initially based on the curves for the reducing cone and the outlet cone to optimize so far that a curve can take over both functions. For this purpose, the reducing cone, which is formed by a curve of higher function (hyperbola, parabola e-function), on its rear, the The part facing the polishing caliber is converted into a curve with an almost linear course. The one calibrated in this way Part should encompass an angle of approx. 25 ° and not exceed the following limit values:

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Roll diameter

Caliber depth above the caliber base circle

1200 - 850 mm 840 - 400 mm 390 - 250 mm

1.5 - 1.8 mm / 10 degrees 0.8 - 1.2 mm / 10 degrees 0.4 - 0.6 mm / 10 degrees

In the subsequent area between approx. 25 and 50 °, the curve follows the function

η y = d (a + b e ^c ' ^x ).

Depending on the roll barrel diameter, the limit values are:

Roll diameter

function

1,200 - 850 mm y = d * I9.42153 * 1O " ² +1.344203

d = 14.25 to 20.0

840

- 400mm y = d.Ii, 94Ο49 · 1Ο " ¹ + 1.32633 * 10 ~ ³ .e ⁶ ' ⁴⁰⁹⁶ ' (5ο) _J

d = 7.3 to 14.3

- 250 mm y

Γ / x \ ⁰ ' ⁶

= d · [ΐ, 94θ49 · 1θ " ¹ + 1.32633 · 1Ο" ³ · β ⁶ ' ^4θ96 Ί5θ) _

d = 4.0 to 7.2

According to the invention, the working range of the roller is expanded from 180-210 degrees to 210-235 degrees. The division of the working area into working cone / outlet - polishing caliber - working cone / outlet takes place with proportions of approx. 36 %, 28 % and 36 %.

During machining, the angles of the

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" ⁷ " 29432A0

individual working areas for all roll barrel diameters kept constant with a fluctuation of plus / minus 3 degrees.

The calibration according to the invention enables a type of calibration and pass diameter sequence adapted to the roll barrel diameter to minimize the reworking rate and to avoid roll breakage. In this case, a calibration according to the invention with two reducing cones is used in the upper roller diameter range (30% to a maximum of 40% of the workload).

For the remaining approx. 60 % of the workload, conventional calibration is carried out with only one reducing cone. This eliminates the stress cracks in the area of the second mouth and the associated negative effects.

In the upper roll diameter range, after six uses, a pass diameter that is at least as high as the post-rotation rate is obtained incised. This larger caliber diameter is then used for another 4-6 inserts with two reducing Maintain cones. Then it is recalibrated to the conventional caliber shape. The selected caliber diameter must be greater by at least the rate of rotation.

In the accompanying drawings, both the usual caliber shape as well as the caliber shape according to the invention shown schematically.

Show it:

1 shows a conventional calibration

2 shows a calibration proposed according to the invention

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29432A0

The working range of the rollers can be seen from FIG. 2, namely from 0 to III, ie from 210 to 235 degrees. The division of the working area into working cone / outlet - polishing caliber - working cone / outlet is proportionally approx. 36 %, 28 % and 36 %, with these angles being kept constant during reworking of the individual working areas for all roll barrel diameters with a fluctuation of plus / minus 3 degrees will.

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Readers

Claims (1)

- ■ PATENTANWALTSBÜRO BERLIN - MÖNCHEN 'PATENTANWÄLTE DIPL-ING. W. MEISSNER DIPL-ING. P. E. MEISSNER DIPL-ING. H.-J. PRESTING Authorized Representatives before the European Patent Office Professional Representatives before the European Patent Office thr sign your letter from our sign Case 20 326 / Mjr / bey HERBERTSTR. 22, 1000 BERLIN 33 10/22/1979 Mannesmann AG 4000 Düsseldorf "Pilger roll calibration" claims 1. Pilger roll, which consists of a reducing cone, a polishing ^ "caliber and an exit cone calibration having, characterized, that a) the reducing cone on its rear part facing the polishing caliber in an angular range of almost 25 ° runs linearly and the subsequent area between 25 ° and 50 ° of the function 130018/0529 '' Branch (§38 PaO) TELEX: TELEGRAM: PHONE: BANK ACCOUNT: CHECK ACCOUNT: Munich: 1-856 44 INVENTION BERLIN BERLINER BANK AG. W. MEISSNER, BLN-W St. ANNASTR. 11 INVEN d BERLIN 030/891 SO 37 BERLIN 31 122 82-109 8000 MONKS 22
TEL .: 089/22 35 44 030/892 23 82 3695716000 ORIGINAL INSPECTED y = d. (a + b e ^c '*) follows, b) the working range 0 - III of the roller ranges from 210 - 235 degrees, c) the division of the working area into the working cone / outlet - polishing caliber - working cone / outlet in a ratio of approx. 36 %, 28 %, 36 % takes place. Use of a pilger roller according to claim 1 with the measure that after several uses the caliber is reworked by machining, the angles of the individual working areas for all Roll barrel diameter are kept constant within a tolerance of plus / minus 3 degrees and that the outlet cone is conventionally calibrated for the last use or operations. 130018/0529