SU1433535A1 - Method of straightening continuous articles - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular to the technology of metal straightening, and can be used in metallurgy and mechanical engineering for straightening non-rigid long products, as well as small batches of long products of a wide variety of sizes. The purpose of the invention is to improve the quality of editing products. The product (s) 1 is mounted on supports 2 and 3, and the force is applied by means of a loading device 6. In the process of dressing, supports 2 are displaced relative to supports 3, and supports 3 are moved vertically. The displacement of the supports or the provision of a gap between the I and one or two of the supports 2 and 3 closest to the point of application of the force before applying the force causes the straightening force to be perceived by several supports 2 and 3. As a result, the stress from the weight load and reactions decreases. Supports 2 and 3 in the areas of I 1 that are remote from the place of application of force and the quality of those who passed the rule of I 1 increases. I zp f-ly, 3 ill., 2 tab. (//

Description

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The invention relates to the processing of metals by pressure, in particular to the technology of metal straightening, and can be used in metallurgy and mechanical engineering for straightening non-rigid long products, as well as small batches of long products of a wide assortment.

The aim of the invention is to increase the quality of straightening non-rigid long products by reducing the stresses caused by the weight load and the reaction of the supports by more evenly distributing the load between the supports.

Fig, 1 shows the editing scheme on three pillars; Fig. 2 is the same, in chtephekh, whereby the necessary clearance between the supports and the product is preliminarily established; in fig. 3 is an editing scheme that implements the proposed editing method with supports moving during the editing process.

In FIG. 3, the principles are accepted. The following definitions: 1 product to be edited; 2 — fixed supports; 3 - movable supports; 4 - stops providing the horizontal position of the item before straightening; 5 — stops that limit the movement of the supports 3 to h; 6 - loading device; 7 - control valve; 8 - support cylinders 3; 9 - hydraulic cylinder loading device 6.

The method is implemented as follows.

The method of straightening is carried out by placing the products on supports and on applications that are perpendicular, perpendicular to pro-. the axial axis of the product, while the supports located on both sides of the place of application of force and closest to it, are placed at a distance from more distant supports, not less than 0.866 distances between the supports closest to the force, and by the time of the beginning of plastic deformation of the product or both pairs, closest to the place of application of the force, are displaced from the position ensuring the horizontal position of the product before straightening, in the direction of the force acting by the value h, determined by the ratio

C. AB GrA 2A + ZV

2Ed 3Ed 2A + B where GT is the limit to account for the material

products; E is the modulus of elasticity;

to

20

25

, "35

d is the diameter of the product on the straightened area;

A is the distance from one of the supports closest to the point of application of the correction, to the nearest more distant support; B is the distance between the nearest

to effort supports. Preferably, the forces closest to the point of application of the support are fixed in such a way that, before the beginning of the straightening, between the bottom and the product there is a gap equal to h,

The displacement of the supports or the provision of a gap between the product and one or two supports closest to the place of application of force before application causes the straightening force to be perceived by several (at least three) supports, while at a distance from the place of application the edging of the product decreases from the weight load and reactions of the supports, which leads to an increase in the quality of the processed products.

The quantitative ratios of the proposed method of editing are chosen as follows,

Considered two extreme cases of the ratio of the weight load and the stiffness of sections of products

When editing hard or relatively light products, if GrAB

h

2Ed

 This straightening force is perceived only by two supports, between which the force is applied, and the remaining supports are not loaded, do not directly participate in the straightening process and do not reduce the stresses of the weight load. With a further increase in the value of the displacement, the dressing force is distributed between a large number of supports. Finally, with an increase in the displacement (gap) above the value

 Г В 2А 1 Ed L 2 3T2A + ByJ, the dressing force is fully perceived by external (relative to the main, closest to the place of application of the force and covering it) the supports, while the main bearings are not loaded and the pattern changes, the editing force changes, the quality of editing Therefore, for rigid or relatively lightweight products, the condition must be fulfilled.

h

, C5, A

Gd + B 2A 1 1 2 - 3 (2A + B) J

O-ch-i

2Ed Ed 2 3 (2A + B).

When straightening long products with a relatively large linear weight at displacement values (gap) h within

GTA 2А + ЗВ 3Ed 2А + В

The straightening force is distributed between the ocHoaHbtt-iH and the supporting external supports, the latter providing a reduction in the stresses of the weight load. For large values of h, the main supports are completely unloaded and the entire straightening force is distributed only between the external supports. As in the previous case, this leads to a change in the conditions and quality of edits.

Real products occupy an intermediate position in relation to the cases considered.

As always

GrA .Ed

L B 2 3 (2A + B) J

GrA 3Ed

2А + ЗВ 2А + В

2А + ЗВ GrAB

2A + B

2Ed

at

L 2

It turns out that in the entire possible range of ratios of the weight and stiff parameters of the products, the purpose of the invention is reached at 866-B;

GrAB (5 tА 2А + ЗВ

2Ed 3Ed 2A + B Article 1 is mounted on fixed 2 and movable 3 supports. The latter are equipped with hydraulic cylinders 8 and stops 4 and 5, limiting the movement of the supports: the stops 4 correspond to the upper position of the supports 3 ensuring the horizontal position of the product before straightening, and the stops 5 restrict the movement of the supports 3 to a given offset value h. The dressing force is created by the loading device 6 with the hydraulic cylinder 9, the cavities of which are connected via the control valve 7. The piston areas of the hydraulic cylinders are chosen so that each of the hydraulic cylinders of the supports 3 creates only a certain proportion of the loading device force, for example, 1/4 . Before the start of the adjustment, the valve 7 is open, the product 1 is not loaded, and the supports 3 are in the extreme

1433535

0

five

0

five

0

five

0

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top position. Then the valve 7 is closed and with the help of a loading device they begin to deform the product. At the same time, the supports 3 begin to shift from down to the original position. When a certain force is reached, the straightening of the support 3 is fixed by the stops 5 at the position corresponding to the specified displacement value h, and the loading device continues to increase the straightening force up to a certain value ensuring the linearity of the product axis after straightening. Then, using an external control device (not shown in Fig. 3), the pressure from the hydraulic system is supplied to the cavities of the hydraulic cylinders, ensuring removal of the loading device 6 and the return of the supports 3 to the initial position (to the stops 4).

Example 1. A product formed by successive welding of pipes, 045x4, ЗМООО и080х22 "" 2000 from steel 12X18H10T to each other, is subjected to straightening. Four supports are located in the middle of pipes 0 80 X22x2000 and near the welds: 1 mm. The editing force is applied to the middle of the product,

Editing is carried out according to the proposed method with moving the supports closest to the place of application of the force, and the displacement of the supports is limited to 5.12 or 19 mm. For this material and the layout of the supports, the calculated displacement limits are 11 mm and 12.3 mm.

In tab. Figure 1 shows the calculated values of the stresses on the supports and the maximum stresses in the welds when straightening (the indicated data refer to the moment of the onset of plastic deformation of the product).

Table 1

50

4020

114

55

PRI mme R 2. The product, similar to the product from example 1, is welded from

1) rub080 22 2000,, and 80 22 22 из 2000 from steel 12X18H10T, Chet-ffe supports are located at the edges of the product jiiw. And in the places of welds,; In tab. Table 2 shows the results of {calculating the correction parameters for the pre-set tiaeMOMy method with the internal supports set in advance with the necessary clearance, as well as the calculation for reference on the known sposbbam. The straightening force is applied in the middle of the product to eliminate the existing margin

 | T a 9 l and c and 2

i From the examples, it follows that in these cases the use of the proposed {method provides a significant 5; S1Schizheniya stresses in parts of the product; remote from the straightened area,

Thus, the proposed method allows, due to the redistribution of efforts between, from; with the supports, to reduce the stress of 40 NIN in areas of the product that are not directly corrected, and to avoid occurrence during correction of the secondary curvature of the product and residual stresses and in the result increase the quality of the edited products,

S

five

Claims (2)

1. A method of straightening lengthy products, including mounting the product on several supports and applying to the product perpendicular to its extension axis of the bending force, about tons of l. that, in order to improve the quality of product editing by reducing the stresses caused by the support reactions, the supports located on either side of the place where the USH1 is located closest to it are installed from more distant supports less than 0.866 the distance between the supports closest to the force, and by the time of the beginning of plastic deformation of the bend of the product one or both of the supports closest to the place of application 5 are displaced from the position ensuring the horizontal position of the product before straightening, in the direction of the force Inu h, e n is determined by the ratio SztAV, GjA 2Ed. 3Ed 2А + ЗВ 2А + В where O .. is the yield strength of the material of the product; E is the modulus of elasticity; d is the diameter of the product in the etched area; A is the distance from one of the supports nearest to the point of application of the force to the nearest more distant support j B is the distance between the supports nearest to the force. 2. The method of pop, 1, is different and - With the fact that the closest to the place of application of force, the supports are fixed in such a way that before they begin to edit, the merchandise and the product provide a gap equal to the value of h. FIG. one FIG. g