SU1454540A1 - Method of producing roll-formed sections - Google Patents

Abstract

The invention relates to the processing of metals by pressure and is intended for use in the molding of parts of curved rolled sections, mainly of the type of channels with a constant height of the flange, consisting of extreme sections with wide and narrow walls of constant width and an average section with a wall of variable width on a roll bending mill. The purpose of the invention is to improve the quality of profiles by eliminating reformed. The invention relates to the processing of metals by pressure and is intended for use in forming parts of curved profiles of a prrkat, mainly of channel type with a constant height of the shelf, consisting of extreme sections with a wide and narrow wall of constant width and middle section with a wall of variable width on the bending equipment. The aim of the invention is to improve the quality of the profiles due to the elimination of the shelves in the wall. In the molding process, the shaping forces are applied to the shelves in all sections of the profile and shear forces to the bending points in the middle section of the profile. The shearing forces from the outer side of the bend sites begin to apply when passing through the axial plane of the rolls of the transition section from the wide end section of the profile to the middle section. The inner surface of the places of bending is freed from the influence of the shaping forces, beginning at the wide wall section when passing through the axial plane of the rolls of the section that is from the mentioned transition point at a distance equal to the length of the contact surface of the upper roll with the bend sheet beyond the axial plane of the rolls . The method makes it possible to reduce the laboriousness of the work on setting up the mill, as well as to improve the quality of the profiles by eliminating the reshaping of the shelf into a wall in the middle section with a variable width. 5 il. (L ael 4ib sd 4ib 10 reforming shelves into a wall and seizing the elements of the rolls. Fig. 1 shows a channel with a variable width of the wall, a general view; Fig. 2 shows the diagram of forces acting on the place of bending and the profile shelf when forming middle section with a wall of variable width; in Fig. 3 - section A-A in Fig. 2; in Fig. 4 - working stand of the mill for forming a channel with a variable width along the wall, general view;

Description

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On the other hand, with the removal of the upper section at the moment of the entry of the middle section with the wall of variable width into the forming planks, it is a top view.

In the process of forming profiles of channel type with a variable width of wall 1 in width, the extreme narrow and wide sections 2 and 3, respectively, with a constant wall width and middle section 4 with a variable wall width, are used for rolls 5 and 6 a wide end simultaneously with the application of the shaping forces to the bending of the shelves 7, transverse shear forces are applied on all sections of the profile from the external surface, to the place 8 of the bend. At the same time, the shear forces PC begin to apply when passing the rolls 5 and 6 through the axial plane of the transition section from section 3 with a wide wall to the middle section 4, and the inner surface of the bend places 8 is freed from the action of the forming force by starting release on the section of the wide wall 3 at passing through the axial plane of the section rolls located from section B-B at a distance L equal to the distance of the contact surface of the upper roll 5 with the place 8 of the bend behind the axial plane of the rolls. The time t required to cross-section B through the distance L is determined by the calculated

t r: - sin, De-2rsin2 |),

etc , . where d is the total angle of the hem in this transition, hail;

D - forming upper in

roll, mm;

Mr. V

etc

inner bend radius, mm;

profiling speed, mm / s Releasing the inner surface of bending site 8 from the impact of forming forces at time t before applying shear to the profile on the outside, which begins to be applied when passing through the axial plane of the rolls of section Bb of the transition from the extreme section 3 with a wide wall constant width to the middle section 4 with a wall of variable width, allows you to start the displacement of the upper forming element to the profiling axis at the moment when it begins to contact the inner surface of the month that 8 bend

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five

540

0

a profile in the cross section of the transition of the end section 3 with a constant wall width to the middle section 4 with a variable wall width. The lower forming element begins to shift later, at the moment of passage of the said cross section of the transition through the axial plane of the rolls.

Thus, the upper forming element does not prevent the profile from tapering in a section of variable width, the profile bend is qualitatively molded in the middle section with a wall of variable width, the shelf does not reshape into a wall.

The method can be implemented with the help of a number of working stands of a profiligene mill, each of which contains frame 9, top 5 and bottom 6 forming rolls mounted on shafts 10 and 11 with the possibility of axial movement. Each wasp cage contains mechanisms 12 and 13 of the movement of the rolls 6, made in the form of hydraulic cylinders, which begin to work on command from BU 1 and BU 2 (control units), including by the signal from contact sensors CD 1 and CD 2, respectively, installed along the profiling and in contact with the front end. The profile thus controls the cross section. -B-B in its different positions. So the sensor CD 1, coming into contact with the front end of the profile, gives a signal to the control unit BU 1, which, using a time switch, which takes into account the speed of profiling Vj, p, turns on the mechanism 12 for moving the roll 5 at the moment the contact of the inner surface of the bend in section B -B (when it is in position B -B) with an upper roll 5.

Accordingly, when the front end of the profile contacts the CD 2 sensor, it gives a signal to the control unit BU 2, which, using a time relay, activates the mechanism 13 for moving the lower forming element of the roll 6 at the moment of passing through the BB section (its position) to the axial plane of the rollers.

If the inner surface of the place of bending is freed from the influence of the forming forces during time t (less than the estimated time t), then the width of the wall will correspond to the width of the edge30

35

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45

50

55

there is a section 3 with a wide wall of constant width. As a result, the middle section 4 will be poorly molded, the shelf will be reformed into the wall.

If the inner surface of the place of bending 8 is freed from the influence of the forming forces during time tj (greater than the estimated time t), then the width of the upper roll 5 even at the time of forming the extreme section 3 with a wide wall of constant width will correspond to a wall of smaller width in the middle section 4 s variable wall width. As a result, at the extreme section 3 with a wide wall of constant width, the place of the 8th bend will be undeformed, with an inner radius greater than the calculated one, which reduces the strength characteristics of the channel bar. For example, the time t for which the inner surface of the bend 8 is freed from the influence of the shaping force before the shearing force is applied from the outer side of the profile, which begins to be applied when passing through the axial plane of the rolls of the transition section from the end portion with a wide wall of constant width to the middle section with a wall of variable width, i.e. the time during which the upper roll begins to shift before the beginning of the mixture (the lower one in the fifth stand of the mill when forming the channel 200 (250) X 90 X. 4 will be

t --- sin, | 2r (D5Vnp

2rsin2 |)

35Qsin | - 20 (400-2-10 sin2 | u, 16 c,

The lice values in the formula are substituted in mm and in mm / s.

If we start the displacement in time, 15 s, then the inner surface of the profile bend in the middle section with a variable wall width will be in contact with the upper roller, which corresponds at that moment along the width to the outer section with a wide wall equal to (tt): (0.16, 15) mm. As a result, the profile shelf will be reshaped into the wall.

If we start the displacement in time t 0.17 s, then the internal surface of the bend at the extreme section of the profile will not be in contact with the upper roller on the length (t -t) V |, p (0.17-1.16) mm, since upper

145D54i

. The roller will begin to move before this surface comes into contact with it. As a result, the place of bending will be reformed, with an inner radius, large calculated, which reduces the characteristics of the channel.

As shown by the data of experimental verification as a result of using the Q of the proposed method, when forming profiles with a variable width along the wall width, the maximum deviations for the channel 200 (250) x 90 x 4 along the flange width in the middle section of the profile g with variable width are ± 1.5 mm that meets the requirements of the standards for these profiles.

The invention, in comparison with the known Q method, has the following

advantages: quality profiles are increased by eliminating re-shaping the shelf into a wall in the middle section with a variable width of the wall, 5 maximum deviations in the width of the shelf when producing channel 200 (250 x 90 x 4 are ± 1.5 mm, while The known method is up to -5 mm, P reduces the laboriousness of the work on setting up the mill, since in the case of simultaneous displacement of the upper and lower forming elements, constant adjustment of each stand is necessary in order to at least partially compensate for molding; it provides the possibility of introducing a new technology that allows profile-type profiles with channel widths of variable length along the length to be produced.

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Claims (1)

Formula invented Shadows A method of making bent rolling profiles, mainly of channel type with a constant shelf height and variable wall width, by successively bending the profile flanks in the rolls of the roll forming mill by applying bending forces on all sections of the profile and shearing forces to the bending points in rolls five 0 five wide end, distinguished by the fact that, in order to improve the quality of the profiles, consisting of extreme sections with wide and narrow walls of constant width and the middle section of the change associated with them fPue. Fi.Z КЩЩЩ КKD2 L.I V