RU2077400C1 - Method of making parts with non-parallel edges - Google Patents

Abstract

FIELD: cutting sheet metal by strips having width variable along their length. SUBSTANCE: method comprises steps of providing at least two mutually parallel portions with lengthwise variable width for part to be made on constant-width blank; forming on each of said portions corrugations having development of cross section with lengthwise variable width increased in opposite directions for providing constant width of said portions for each part to be made; longitudinally separating said blanks at simultaneously trimming their peripheral and reshaping corrugation to plane for making parts with non-parallel edges turned by 180 degrees one relative to another in plane of blank. EFFECT: enhanced efficiency. 2 cl, 8 dwg

Description

 The invention relates to the processing of metals by pressure and is intended for use when cutting sheet material into strips with a variable length in width and manufacturing parts with non-parallel edges, including a cross-sectional sweep that varies in length.

 A known method implemented in a device for the longitudinal cutting of sheet material (see as.with. N 1156867, class B23D 19/08, 1985), which consists in the fact that directly when cutting to the edges of the workpiece are applied transversely directed during the cutting process compressive forces, which allows to obtain a workpiece with non-parallel edges (with a variable length along the width).

 Significant disadvantages of this method include the low productivity due to the need for a smooth application of compressive forces, and, accordingly, the low cutting and moving speeds of the strip, since when the strip moves faster and transverse forces are applied, jamming of the knives and their breakage is possible. In addition, setting up the device on which the described method is implemented when switching to a new workpiece size is a very time-consuming operation. In addition, in connection with the manufacture of one piece from each blank, comparatively large peripheral sections pass into the trim (metal waste).

 Closest to the technical nature of the claimed is the selected as a prototype for the manufacture of parts with varying lengths of the scanning width of the cross section, the author M.E.Doktorov (see application for invention N 4926138/27, class B 21 D 5/06 from 04/08/91 , according to which a decision was made on the issuance of AS from 08/26/91).

 In the manufacture of parts according to the specified method, forming is provided on a flat workpiece with a constant width of the corrugations with a varying cross-sectional scan length, trimming the peripheral sections of the intermediate workpiece before molding the corrugation into a plane to obtain an intermediate workpiece of constant width and shaping the part of a given shape and size.

 At the same time, in order to reduce the complexity of manufacturing parts and increase productivity, at least two parts and a technological jumper are made from one billet, while sections with a variable length width for future parts are placed on the workpiece in parallel with each other, and a section of the technological jumper with a variable the length of the width is placed on the workpiece between them, corrugations with varying lengths are formed on each of the mentioned sections, ensuring parallelness of the boundary lines of the sections of future parts it simultaneously with cutting and removal of the peripheral portions is carried longitudinal separation of blanks and removing the jumper, and the details given shape and dimensions of the resulting molded preforms.

 The prototype under consideration also provides in some cases for the manufacture of parts from a workpiece, the width of which corresponds in cross sections to at least the sum of the maximum widths of the sections of the workpiece with a variable sweep width for two parts and the width of the workpiece section for the technological bridge between them.

 Significant disadvantages of the prototype include the increased complexity of manufacturing parts with non-parallel edges and low productivity, due to the need for additional manufacturing between parts of the jumper with a variable length and its removal in the profiling stream from the mill. At the same time, there is an increased metal consumption due to the departure of the jumper into the edge.

The aim of the invention is to increase productivity and reduce waste due to the manufacture of adjacent parts rotated in the plane of the workpiece at an angle of 180 ^o relative to each other.

 To achieve this goal, in the method of ME Doktorov for the manufacture of parts with non-parallel edges, along which at least two sections with a variable width for future parts are parallel to each other are placed on a blank of constant width, molding on each of the said sections of corrugations with variable along the length of the sweep width of the cross section to ensure the constancy of the width of the mentioned sections for each of the future parts, the longitudinal separation of the workpieces simultaneously with the cutting of peripheral parts weaving and re-shaping the corrugations into a plane to obtain parts with non-parallel edges, forming corrugations in two adjacent sections of the workpiece for future parts is carried out with an increase in the width of the development of corrugations of one section and with a decrease in the width of the development of corrugations of another section.

In the manufacture of parts according to the claimed method, it is advisable to combine the boundary lines of adjacent future parts along the length on the workpiece, and determine the width of the workpiece according to
B _zag ≥b _max +0.5 (b _max + b _min ) (n-1), (1)
where B _{zag the} width of the workpiece;
b _max and b _min maximum and minimum scan widths of the part, respectively;
n the number of parts placed in the workpiece across the width.

The manufacture of at least two future parts from one workpiece rotated in its plane by an angle of 180 ^o relative to each other and the increase in the width of the corrugation sweep along the length on adjacent sections of the workpiece for future parts in opposite directions, allows the simultaneous molding of at least two parts without making jumpers along the length between them and thereby reduce the complexity of manufacturing parts and increase productivity. In this case, the rotation of two future parts in the plane of the workpiece at an angle of 180 ^° relative to each other allows you to place sections in the workpiece for making parts from them parallel to each other without jumpers, and then after parallelizing the corrugations with varying lengths in the sections of future parts, maintain this parallelism , arrange the future edges of the parts parallel to each other along the workpiece and further divide the workpiece by longitudinal cutting along straight lines with high-performance methods, for example Measurement by cutting with circular knives in the profiling stream. It should be noted that the placement according to the claimed method in the workpiece of at least two sections to make parts of them parallel to each other and without jumpers allows to reduce metal waste in the trim in comparison with the prototype, since according to the claimed method only peripheral sections of the workpiece are cut when forming from it at least two parts, while according to the prototype peripheral sections of the workpiece provided for each part fall into the trim.

 In this case, according to the claimed method, one part will account for 2 / n of peripheral sections going to waste, while for the prototype, the waste is determined by the total value of 2 / n + P, where P is the waste in the form of a jumper per one part. In this regard, in the manufacture of parts according to the claimed method, the metal consumption will be less than the prototype.

 The increase in the width of the development of corrugations along the length of adjacent sections of the workpiece for future parts in opposite directions allows you to shift and direct the boundary lines between future parts in the plane of the workpiece along the profiling line, preserving their straightness, and to ensure parallel placement of future parts in the workpiece, abandoning the jumpers between them and to further divide the sections of the workpiece by longitudinal cutting along the mentioned boundary lines in a high-performance non-waste way, for example Emer circular knives in flow profiling.

 In order to reduce metal waste in the manufacture of parts by reducing the allowance for length in the workpiece, the future parts are combined in length.

 According to the claimed method, parts of the same or different shapes can be manufactured, and their manufacture can be carried out by technological transitions both simultaneously and sequentially.

The width of the workpiece B _zag , from which parts are made according to the claimed method can be constant in length and correspond to the value determined by the formula (1).

Moreover, the correspondence in the cross sections of the width of the workpiece to the value (1), allows to reduce the consumption of the workpiece in comparison with the prototype, for which the width of the workpiece will correspond to the value n • b _max , by a value of 0.5 (n-1) • (b _max -b _min ).

 It should be noted that the inventive method can be used not only for the manufacture of flat parts with non-parallel edges, but also for bent profiles with a cross-sectional sweep width varying in length, as well as for producing flat parts with corrugations of constant and variable sweep width .

 To form corrugations with a sweep width varying in length, universal rolls are used, on one of which protrusions with variable sizes along the perimeter of its barrel are made, on the other a hollow, the depth of which corresponds to the maximum height of the protrusion. The longitudinal cutting of the workpiece with the corrugations made on it is carried out in one of the working stands of the mill with the help of circular knives mounted on the shafts.

 For the corrugation to corrugate into a flat section during the forming of the part, rolls with cylindrical sections can be used.

 The invention is further illustrated by the description of specific, but not limiting, embodiments of the invention and the accompanying drawings, in which: FIG. 1, a blank for the manufacture of parts with a variable cross-sectional scan length, dashed lines indicate the contours of the sections of the blank for the part, FIG. 2, a blank for manufacturing three parts; FIG. 3 a variant of the intermediate blank after forming corrugations with a variable length scan in the areas intended for parts, in FIG. 4 separate sections of the workpiece for parts and for trimming after longitudinal separation of the intermediate workpiece, in FIG. 5 parts with non-parallel edges, dashed lines highlighted "excess" of metal, laid in the corrugation, in Fig. 6 is a diagram of technological transitions used for shaping parts with non-parallel edges; FIG. 7 is a variant of the caliber of the rolls for shaping the corrugations in sections of the workpiece for parts, FIG. 8 is a section along A A of the rolls in FIG. 7.

According to the claimed method in the manufacturing process of parts with non-parallel edges, it is advisable to use a workpiece of constant length L width B _zag (Fig. 1) to simultaneously perform at least two parts. The feasibility of using a workpiece of constant width, and not variable (without edge sections going to waste), is confirmed by the possibility of obtaining it from a roll blank by a relatively simple and high-performance method by longitudinal cutting with circular knives on a longitudinal dissolution unit. To obtain a curly blank without edge sections that go to waste (trimming), it is necessary to use additional low-productivity labor-intensive technological operations, including cutting and slitting. In addition, the manufacture of parts from such a workpiece is difficult due to the lack of base sections on the workpiece to center it in the rolls and in the mill during the shaping of parts. At the same time, sections 1 and 2 with a variable in length L of width b _s (from b _max to b _min ) are placed parallel to each other in the workpiece to make parts of them, and sections 3 and 4 of the workpiece are future waste and are subsequently separated from the workpiece longitudinal sharp, for example with circular knives, and are removed in the form of trimmings having a variable width Δb in length, varying from Δb _min to Δb _max .

It should be noted that a workpiece of constant width of appropriate sizes can be used for the manufacture of three (Fig. 2) and more parts. Moreover, the workpiece contains sections 1 and 2 for making parts, each of which is rotated relative to adjacent in its plane by an angle of 180 ^o relative to each other, and two edge sections 3 and 4. It is not advisable to provide jumpers between future parts in the workpiece because of the increased metal consumption of the workpiece and the complexity of the process of longitudinal cutting.

In the process of manufacturing several parts from one workpiece in sections 1 and 2 (Fig. 1 and Fig. 2), corrugations 5 and 6 (Fig. 3) are formed along the workpiece for future parts with a cross-section sweep width varying along the length L, ensuring a constant width b _dz mentioned sections for each part of the intermediate workpiece. At the same time, the sweep width of corrugations 5 and 6 along the length L in adjacent sections of the workpiece for future parts is increased in opposite directions. Then the boundary line 7 between the sections 8 and 9 of the workpiece for making parts from them, as well as the boundary lines 10 between the mentioned sections 8 and 9 and the peripheral sections 3 and 4 of the workpiece become straight and parallel to each other, and this allows in the same process stream with by forming parts after molding the corrugations in a high-performance way without waste into technological jumpers between the parts, divide the workpiece by the mentioned boundary straight lines 7 and 10, for example, circular knives installed in the work x stands of roll forming mill.

 Corrugations 5 and 6 with a variable cross-sectional sweep width can be made of both variable and constant width along the length by both simultaneously shaping them on the workpiece in one technological transition when profiling in mill rolls, and by alternately shaping them in a number of technological transitions.

The maximum width l _{max of the} scan of the corrugation is located on the side of the maximum width b _{max of the} scan of the part, the width l _min from the side of the minimum width of b _{min of the} scan of the part. The difference between the largest width l _{max of the} corrugation of the corrugation and the maximum length f _{max of the} chord (corrugation width) is kept equal to the difference between the largest width b _{max of the} scan of the part and the smaller width b _{min of the} scan of the part, i.e.
l _max -f _max = b _max -b _min (2)
The dimensions of the workpiece for the manufacture of parts by the present method is determined from the conditions of their placement both in length and in width with minimal waste. In this case, it is advisable to combine future details in the workpiece along the length, and determine the width of the workpiece according to dependence (1). It should be borne in mind that at B _zag = b _max +0.5 (b _max + b _min ) x (n-1) metal _{waste to the edge} is minimal and amounts to V _out = (b _max -b _min ) • S • L, where S and L are the thickness and length of the workpiece. When B _zag > b _max +0.5 (b _max + b _min ) (n-1) metal waste increases and amounts to
V _ref = [(b _max -b _min ) + 2 • Δb _min ] • S • L
It should be noted that in some cases, with insufficient width of the workpiece, the production of parts by the present method can be performed with increased metal waste by longitudinal displacement of future parts relative to each other in the workpiece.

After achieving a constant width b _dz along the length of the sections for future parts, a longitudinal cut of the intermediate workpiece is performed, as a result of which separate blanks 11 and 12 (Fig. 4) of constant width for parts and waste 13 and 14 are cut. Then the trim is removed, and from the obtained individual intermediate blanks of constant width, parts 15 and 16 (Fig. 5) are formed with non-parallel edges 17 and 18. At the same time, the width of the part is increased by straightening the corrugation and moving the "excess" 19 of the metal into the part wall, providing an increase in the wall width from b _dz to b _d , including up to b ₁ and b ₂ at the end sections of the part in accordance with the change in the length of the part of the difference between the width of the corrugation of the corrugation and the length of the chord on which it rests, i.e. "excess" of metal.

In FIG. 6 shows a variant of the sequence of technological transitions during the shaping of parts with non-parallel edges according to the claimed method in rolls of a roll forming mill. In this case, the blank 20 of constant width B _zag after 1 transition (from the master stand) is fed to the subsequent ones. In the second transition, a change (decrease) in the width of the sections of the workpiece 21 is made uneven in length due to the shaping of the corrugations 22 and 23 with the cross-sectional width varying along the length of the scan. In the III technological transition produce a longitudinal cutting of the workpiece and the removal of peripheral sections 13 and 14 in the waste. From the obtained intermediate blanks 11 and 12 with the aforementioned corrugations 22 and 23 in the IV and V technological transitions, parts 15 and 16 with non-parallel edges are formed by straightening the corrugation and thereby obtaining a wall of variable length along the width. In this case, for shaping on the workpiece 21 corrugations 22 and 23 on one of the coaxial rolls lower 24 (Fig. 7 and Fig. 8) protrusions 25 are made with varying circumference of the roll height, and on the second roll upper 26 there are ring cavities reciprocal to the protrusions 27.

 It should be noted that from one workpiece, regardless of the number of manufactured parts, two peripheral sections go into waste, which indicates the advisability of simultaneously producing more parts from one workpiece.

 The inventive method can be implemented using a conventional roll forming mill, in the first stands of which corrugations are formed with a variable sweep width and an increase in the said widths in adjacent sections in opposite directions, and in subsequent stands of the mill on the working shafts there are mounted circular knives for longitudinal dissolution of the workpiece on separate blanks and removal of peripheral sections into waste, as well as rolls for straightening the corrugations on individual blanks and shaping parts with non-parallel to omkami.

According to the above calculations and experimental verification of the claimed invention in comparison with the prototype has the following advantages:
a) the productivity of the equipment increases, since it becomes possible according to the claimed method to produce at least two parts without a jumper in the workpiece between them, while on the base - the productivity of the equipment decreases due to the need for shaping the jumper and its removal in the profiling stream;
b) the consumption of the workpiece is reduced, since in the manufacture of at least two parts according to the claimed method, waste is provided in the form of two peripheral sections of the workpiece going to the edge, while the basic variant provides for the same waste in the form of two peripheral sections and additionally waste in the form of jumpers between future parts in the workpiece.

 With an increase in the number of simultaneously manufactured parts from one billet, the productivity of their manufacture increases, metal waste and the complexity of manufacturing parts decrease.

 The claimed technical solution does not adversely affect the environment.

 The inventive method of manufacturing parts with non-parallel edges is of significant interest to the national economy, as it allows to increase productivity and reduce metal waste in the production of the above-mentioned parts.

Claims (1)

1 1. A method of manufacturing parts with non-parallel edges, comprising placing at least two sections with a constant width on the workpiece of constant width for future parts parallel to each other, molding on each of the said corrugations with a variable cross-section length along the scanning width to ensure constant width of the mentioned sections for each of the future parts, the longitudinal separation of the blanks simultaneously with the cutting of the peripheral sections and the reformation of the corrugations into a plane with obtaining d hoists with non-parallel edges, characterized in that, in order to increase productivity and reduce waste by making adjacent parts rotated in the plane of the workpiece by an angle of 180 <198> one relative to another, corrugations are formed on two adjacent sections of the workpiece for future parts with an increase in width scanning corrugations of one section and decreasing the width of scanning corrugations of another section.2 2. The method according to claim 1, characterized in that the boundary lines of adjacent future parts are aligned along the length on the workpiece, and the width B <Mv> is closed < D> blanks are determined by the dependence In <Mv> zag <D> <$ E >> => b <Mv> max <D> + 0.5 (b <Mv> max <D> + b <Mv> min <D >) <195> (n 1), where B <Mv> zag <D> workpiece width, b <Mv> min <D> and b <Mv> max <D> are the minimum and maximum scan widths of the part, respectively, n is the number of placed in the workpiece according to the width of the parts.

Images