RU2300436C2 - Method for profiling thin-wall sections of flat blanks at preliminary shaping stage and universal apparatus for performing the same - Google Patents

Abstract

FIELD: plastic working of metals, namely manufacture of thin-wall sections.

SUBSTANCE: method comprises steps of cutting flat blank by two bands at preliminary shaping stage; removing burrs from cut line by micro-grinding; feeding cut blank to first profiling stand for preliminary shaping through two grooved passes. In second stand for preliminary shaping lateral deformed portions are bent by value depending upon mechanical properties of blank metal and used shaping schedule. Then cross corrugations are partially rolled out at leveling inner stresses and deformations along cross section due to increased rate of profiling in comparison with profiling rate in first stand for preliminary shaping. First and second profiling stands of apparatus being unit for preliminary shaping and they have working roll drive in the form of system of outer gear transmissions providing possibility for enhancing profiling rate at outlet of first stand. Profiling rolls are paired rolls mounted with possibility of separate profiling of two blanks and they have closed working gage. Shafts for mounting profiling rolls are in the form of inserts. Housing of stand unit is cast of two blocks parting along axis of upper shafts.

EFFECT: improved quality of sections, enlarged manufacturing possibility and enhanced efficiency of process.

5 cl, 6 dwg

Description

The invention relates to the field of metal forming and can be used, in particular, in the manufacture of thin-walled profiles from sheet blanks by roll profiling for aerospace products and the construction industry. The invention is aimed at expanding technological capabilities, improving productivity and quality of bent from a sheet of profiles.

A known method of profiling predominantly channels (AS No. 1754267 USSR, IPC ⁵ B21D 5/06, publ. 08/15/92. Bull. No. 31), which consists in bending of profile elements along transitions with a technological bend of a part of each profile profile with a width of (0 , 25-0.45) b, where b is the width of the shelf, by an angle Δα with subsequent straightening in the last two transitions.

The disadvantages of this analogue are:

profiling is carried out in nine transitions, which is cumbersome for thin-walled profiles, requires an increased amount of equipment;

technological hemming of part of the shelves is carried out at transitions from the third to the seventh, which complicates the equipment;

the strictly regulated width of the flange fold section, its straightening at the last two transitions also complicates the design of the rolls, and in other cases the quality of the profiles is not guaranteed, the edges of the flanges are undulated.

The well-known "Method for the manufacture of bent profiles of hire" according to A.S. No. 1068199 USSR, IPC ⁵ B21D 5/06, publ. 01/23/1984, Bull. No. 3, according to which, in order to improve the profile quality by eliminating the undulation of the shelves in the manufacture of predominantly channels with a variable wall height, sequential corrugation with cross-sectional dimensions that are variable in length along the length, is performed at translations in the place where the constant-width section with the narrowed section are mated; in the section of the future profile wall and gradually decreasing in the sections of future shelves to zero at the edges, and then when folding the shelves the corrugations are straightened out with crowding out metal TCA profiling direction.

The disadvantages of the method are:

uncertainty in the size and location of the transverse corrugation, which does not guarantee quality, because the formed stock of material must correspond to the geometry of the cross section of the profile, the thickness of the workpiece and the mechanical properties of the material;

it is not clear when and at which transition or transitions the transverse corrugation is carried out and how it is straightened during folding (gradually or at the last transition, etc.).

Closest to the technical nature of the claimed is the selected as a prototype "Method for profiling thin-walled profiles and a device for its implementation" according to the patent No. 2236319 of the Russian Federation, IPC ⁷ V21D 5/06, publ. 09/20/2004, bull. No. 26, according to which bending is carried out sequentially in transitions with the provision of the necessary metal supply by rolling transverse corrugations at the first forming transition with a constant step over the entire width of the workpiece, with a depth that decreases gradually from the maximum width of the future profile wall to zero along both edges of the bent sections of the flat workpiece and the displacement of the metal reserve is carried out by rolling the transverse corrugations at subsequent transitions with the elimination of waviness along the edges due to the alignment of deformations and stresses eniya the entire cross section manufactured profile.

The prototype and the claimed invention have the following similar essential features:

rolling transverse corrugations with a constant pitch over the entire width of the workpiece;

ensuring the necessary supply of metal in bending areas;

gradual decrease in the depth of the corrugations from the maximum width of the future wall to zero along both edges of the bent sections of the workpiece;

the displacement of the metal typed in the corrugations in the direction of profiling by rolling during folding of the shelves;

bending sequential in transitions;

There are profiling stands for preliminary shaping.

The disadvantages of the prototype are:

there is no guarantee of the symmetry of the process and quality along the edges of the future profile;

low productivity;

uncertainty in the duration and profile parameters in the second profile stand.

It is known "Device for the manufacture of profiles" (patent No. 2148455, IPC ⁷ B21D 5/06, publ. BI No. 13, 05/10/2000), according to which profiles from sheet blanks are made in alternating forming and pulling working stands, each of which is included in one common kinematic chain associated with the drive. The working stand has two shafts located one above the other, on which roll forming rolls (rollers) are rigidly fixed. The upper shaft of each stand is located at the ends in slide sleeves having the ability to move vertically along the guide cheeks of the stand body.

The device has the following disadvantages:

the complexity of the kinematic chain, consisting of a system of gears, including with additional external gearing, which increases power loss and reduces the efficiency of the device;

there is no certainty in eliminating the waviness along the edges of the bent sections of a thin workpiece (S ₀ ≤1.0 mm), which does not guarantee the quality of the profiles.

Also known is the device presented in RF patent No. 2236319 "Method for profiling thin-walled profiles and a device for its implementation", publ. 09/20/2004, Bull. No. 26, adopted as a prototype, which contains a number of cross-profiling stands installed in the technological sequence, connected by a single kinematic chain with a common drive;

each profiling stand has two shafts located one above the other, with profiling rolls mounted on them;

profiling rolls of the first stand of various designs allow you to create transverse corrugations on the profiled workpiece of variable height with a constant pitch.

The prototype and the claimed invention have the following similar essential features:

contains a number of stands milling for transitions installed in the technological sequence;

profiling stands are connected by a single kinematic chain with a common drive;

each profiling stand has two shafts located one above the other, with profiling rolls mounted on them;

profiling rolls of the first profiling stand have a cylindrical shape, a closed working gauge, made with some clearance to reduce the effort when pulling the workpiece;

the lower profiling fleece is made of metal, has a triangular rounded cross-section over the entire length of the corrugation, alternating with smooth segmented surfaces at a constant step t = (10 ... 20) S ₀ , where S ₀ is the initial thickness of the workpiece;

corrugation height h≤ (3 ... 5) S ₀ from the calculation of the set of excess metal in the corrugations of the workpiece to eliminate profile waviness along the edges;

the upper profiling roll is lined along its length with an elastic material such as polyurethane, taking into account equal stiffness, it creates different heights of the transverse corrugations, the largest in the area of the future profile wall and the smallest (close to zero) at the ends.

These signs are necessary to ensure a technical result.

The device has the following disadvantages:

it is not clear how the workpiece is fed into the first profile stand;

excessive metal consumption, since all stands are of the same width;

poor performance.

The technical result is the expansion of technological capabilities, increasing productivity and quality profiles.

To achieve a technical result, the claimed invention "A method for profiling thin-walled profiles from flat blanks at the stage of preliminary shaping and a universal device for its implementation" contains, in addition to those common with prototypes, the following significant distinguishing features:

a flat billet before entering the first profiling stand is cut and served with two streams, thereby increasing the production program;

remove burrs along the cutting line by micro-grinding, which guarantees the quality of the profiles;

in the second translation, the side of the deformable sections is bent at an angle of 25-30 ° depending on the mechanical properties of the workpiece metal and the adopted shaping scheme, the transverse corrugations are partially rolled out and the internal stresses and strains are aligned over the cross section;

increase at the output the profiling speed by 3-5% compared with the profiling speed in the first preforming stand.

According to the second claim, the flat preform is cut into two strips of different widths and simultaneously profiles of two different cross-sectional shapes are shaped.

According to the third claim, the device is a preliminary shaping unit, consisting of two profiling stands with drive of working shafts through an external gear system with the possibility of increasing the profiling speed at the output of corrugated workpieces from the second profiling stand by 3 ... 5%;

profiling rolls are made paired, have a closed working caliber, mounted on the insert shafts, which increases the productivity and quality of the profiles;

created the possibility of simultaneous independent profiling of two workpieces;

the block body is made of two-part castings with a connector along the axis of the upper shafts with profiling rolls installed.

According to the fourth claim, paired profiling rolls are made of prefabricated, consisting of two parts, each of which has a closed working caliber, respectively, of the adopted profiling scheme;

adjustment to the thickness of the workpiece is carried out by replacing the upper profiling rolls, which simplifies the process and expands technological capabilities.

According to the fifth claim, three guide rollers are mounted on the axis at the entrance to the workpiece in front of the slit in front of the slit, which allows adjustment along the width of each profiled strip;

the central roller is reinstalled according to the cutting line of the workpiece, and the other two are moved along the axis due to the thread in the opposite direction to limit the width of the profiled workpieces.

The technical result is the expansion of technological capabilities, increasing productivity and quality profiles.

To achieve a technical result, the claimed invention "A method for profiling thin-walled profiles from flat blanks at the stage of preliminary shaping and a device for its implementation" contains, in addition to those common with the prototype, the following significant distinguishing features:

a flat billet before entering the first profiling stand is cut and served with two streams, thereby increasing the production program;

remove burrs along the cutting line by micro-grinding, which guarantees the quality of the profiles;

in the second profiling stand, bending of the lateral deformable sections at an angle of 25-30 ° depending on the mechanical properties of the workpiece metal and the adopted shaping scheme, partially roll the transverse corrugations and equalize the internal stresses and strains over the cross section;

increase at the output the profiling speed by 3-5% compared with the profiling speed in the first preforming stand.

According to the second claim, the flat preform is cut into two strips of different widths and simultaneously profiles of two different cross-sectional shapes are shaped.

According to the third claim, the device is a preliminary shaping unit, consisting of two profiling stands with drive of working shafts through an external gear system with the possibility of increasing the profiling speed at the output of corrugated workpieces from the second profiling stand by 3 ... 5%;

profiling rolls are made paired, have a closed working caliber, mounted on the shafts with the possibility of dismantling when disassembling the stand, which increases the productivity and quality of the profiles;

created the possibility of simultaneous independent profiling of two workpieces;

the block body is made of two-part castings with a connector along the axis of the upper shafts with profiling rolls installed.

According to the fourth claim, paired profiling rolls are made of prefabricated, consisting of two parts, each of which has a closed working gauge according to the adopted profiling scheme;

adjustment to the thickness of the workpiece is carried out by replacing the upper profiling rolls, which simplifies the process and expands technological capabilities.

According to the fifth claim, three guide rollers are mounted on the axis at the entrance to the workpiece in front of the slit in front of the slit, which allows adjustment along the width of each profiled strip;

the central roller is reinstalled according to the cutting line of the workpiece, and two other movements along the axis due to the thread in the opposite direction to limit the width of the profiled workpieces.

According to the second claim, the workpiece is cut into two strips of different widths due to a change in the position of the roller cutting knife and two different section shapes are profiled simultaneously.

The method is carried out in a device consisting of a cast housing 3 with a connector on the axis of the shafts 9 of the upper forming rollers 4, 7, the drive of which is carried out by gearing 10, 11 (Fig. 1, 2) through spurious gears meshed with the gear 12, mounted rigidly on the shaft of the individual drive 13. Gear 10 has an increased number of teeth compared to gear 11, which provides a linear speed V ₁ movement of the workpiece from the first forming stand is 3-5% less than the linear speed V ₂ profiling forgings in the second forming stand.

For a set of metal in the form of corrugation 6, the lower metal roller 5 has overhangs periodically alternating in diameter with triangular rounded shapes of height h = (3 ÷ 5) S ₀ , spaced from each other with a step t = (10-20) S ₀ ( figure 3). The upper metal roller 4 has an outer lining 14 of elastic material (polyurethane) of minimum thickness in the area of the non-deformable part of the workpiece (wall) and maximum along the borders of the working caliber (Figs. 3, 4), which guarantees a variable corrugation height across the width of the bent sections of the workpiece due to reduce the rigidity of the polyurethane shell to the edge of the workpiece.

In the second forming stand, the upper and lower rollers 7, 8 are metal, without corrugation, with a smooth cylindrical surface in the central part turning into a conical one depending on the adopted shaping scheme, the upper roller has a lining 15 made of elastic material, which allows slightly (approximately one a third to precipitate the corrugations created on the profiled blank in the first forming stand.

At the entrance to the housing 3 in front of the slit 2 according to paragraph 5 of the claims, guide rollers 16 are installed for adjustment to the width of the workpieces (figure 2). The central roller is reinstalled on the smooth part of the axis, and the extreme ones move in the opposite direction along its threaded part when the axis is rotated manually in the bearings of the bracket.

In the second profiling stand, preliminary bending of the lateral deformable sections of the workpiece is performed at an angle φ ₁ = 25 ... 30 ° depending on the mechanical properties of the workpiece metal and the adopted profile shaping scheme (FIGS. 5, 6). The creation of σ _rast provides axial tension and alignment of stresses and strains along the sections of the workpieces 7, thereby eliminating the edge waviness. The adjustment of working calibers by the thickness of the workpiece is carried out by replacing the upper rollers of the forming stands.

According to the second claim, the workpiece is cut into two strips of different widths due to a change in the position of the roller cutting knife and two different section shapes are profiled simultaneously.

The method is carried out in a device consisting of a cast housing 3 with a connector along the axis of the shafts 9 of the upper forming rollers 4, 7, the drive of which is carried out by means of gears 10, 11 (Fig. 1, 2) through spurious gears engaged with the gear 12, planted firmly on the shaft individual drive 13. The gearing 10 has a large in comparison with the toothing 11, the number of teeth, which provides a linear velocity V ₁ of the workpiece from the first forming stand for 3-5% less than the linear velocity V ₂ zag profiling Preparations for the second shaping stand.

For a set of metal in the form of corrugations 6, the lower metal roller 5 has overhangs periodically alternating in diameter of triangular rounded shape with a height h = (3-5) S ₀ located from each other with a step t = (10-20) S ₀ ( figure 3). The upper metal roller 4 has an outer lining 14 of elastic material (polyurethane) of minimum thickness in the area of the non-deformable part of the workpiece (wall) and maximum along the boundaries of the working gauge (Figs. 3, 4), which guarantees a variable height of corrugations along the width of the bent sections of the workpiece due to reduce the rigidity of the polyurethane shell to the edge of the workpiece.

On the second profiling stand, the upper and lower rollers 7, 8 are metal, without corrugations, with a smooth cylindrical surface in the central part turning into a conical one depending on the adopted shaping scheme, the upper roller has a lining 15 of elastic material, which allows slightly (about one third) to precipitate the corrugations created on the profiled blank in the first forming stand.

At the entrance to the housing 3 in front of the slot 2, guide rollers 16 are installed for adjustment to the width of the workpieces. The central roller is reinstalled on the smooth part of the axis, and the extreme ones move in the opposite direction along its threaded part when the axis is rotated manually in the bearings of the bracket.

From the second profiling stand for preliminary bending, corrugated workpieces 17, 18 (Fig. 6) enter the stand for subsequent and final profile shaping.

According to paragraph 4 of the claims, the paired profiling rolls are prefabricated, consisting of two parts, each of which has a closed working gauge according to the adopted profiling scheme. In figure 4, adjustment for the thickness of the workpiece S _{0 is} carried out by replacing the upper profiling rolls.

According to paragraph 5 of the claims, at the input of FIG. 5, the blanks into the block body of the first and second profiling stands 5, 10 are cast, stepped in plan with a connector along the axes 32 for assembly and disassembly when replacing the profiling roller pairs. The installation of the rolls on the shafts 26 with a center distance A provides for dismantling during parsing. The stepped shape is associated with a decrease in the width of the profiling rolls.

Claims (5)

1. The method of profiling thin-walled profiles from flat blanks at the stage of preliminary shaping, including the creation in the first profiling stand of the preliminary shaping of the necessary supply of metal by rolling transverse corrugations over the entire width of the blank with a constant step depth that decreases gradually from the maximum width of the future profile wall to zero along the edges of the bending sections of the flat workpiece, and bending in the second profiling stand, characterized in that they cut the plane of the preform into two strips, the burrs are removed by micro-grinding along the cutting line, and it is fed into the first profiling pre-forming stand with two streams, in the second pre-forming stand, the side deformable sections are bent at an angle of 25-30 ° depending on the mechanical properties of the preform metal and of the adopted shaping scheme, the transverse corrugations are partially rolled out and the internal stresses and strains are aligned over the cross section due to the profiling speed increased by 3-5% as compared with NIJ velocity profiling in the first stand preliminary shaping. 2. The method according to claim 1, characterized in that the flat preform is cut into two strips of different widths and simultaneously profiles of two different cross-sectional shapes. 3. A device for profiling thin-walled profiles from flat blanks at the stage of preliminary shaping, containing profiling stands, each of which has two shafts located one above the other, with profiling rolls mounted on them, the lower roll of the first profiling stand of cylindrical shape is made of metal with constant step corrugations in the form of rounded protuberances of triangular cross-sectional shape h≤ height (3 ... 5) S _0, where S ₀ - the initial thickness of the blank, alternating with smooth Segment surfaces, the upper profiling roll is made of metal, has a cylindrical shape in the area corresponding to the profile wall, smoothly turning into a conical shape in the area corresponding to the foldable shelves, and is lined along the entire length with elastic material having the smallest thickness on the cylindrical part, gradually increasing to ends, characterized in that the first and second profiling stands are a preliminary shaping unit and have a drive of working shafts, made in the form of a system in external gears with the possibility of increasing the profiling speed by 3-5% at the exit of the corrugated workpieces from the second profiling stand relative to the speed at the exit of the first stand, while the profiling rolls are paired with the possibility of simultaneous independent profiling of two workpieces, have a closed working gauge, shafts for the installation of the profiling rolls is made in the form of inserts, and the block body is molded in two parts with a connector along the axis of the upper shafts. 4. The device according to claim 3, characterized in that the paired profiling rolls are prefabricated, consist of two parts, each of which has a closed working gauge according to the adopted profiling scheme, while the upper profiling rolls are made with the possibility of replacement for adjustment to the thickness of the workpiece . 5. The device according to claim 3, characterized in that it is equipped with three guide rollers mounted at the input of the workpiece into the block body in front of its slit on the axis to allow adjustment of the workpiece width, while the central roller is configured to reset accordingly the workpiece cutting line, and the other two are axial movements in the opposite direction to limit the width of the profiled workpieces.

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