RU2582169C1 - Method of producing tubular elements from metal rubber material and mould therefor - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metal forming. Production of tubular elements from MR material involves obtaining pieces of wire in form of stretched spirals. Billet is formed as roll with hole. Blank is placed in mold and compacted in two passes. Pressed in two directions perpendicular to axis of symmetry of workpiece opening. After first pass is obtained tubular blank with two ledges on outer surface. At second step element of cylindrical shape is obtained. Provided device to implement this method. Mold consists of holder for even and odd passes. Cartridge contains matrix, two pairs of male dies. Working end of punch forms with inner surfaces of plates matrices cartridge blunt and sharp edges. Width of punch holder for each subsequent transition is less than width of punch holder for previous transition. Puncheons are composed in form of tee.

EFFECT: technical result is production of parts of MR material with same density along whole length, simplified production of parts from MR material due to combination of several identical transitions, simplified design of mould.

6 cl, 6 dwg, 1 tbl

Description

The group of inventions relates to the field of metal forming, in particular to the processing of metal rubber material (MP) - a metal analogue of rubber, in the manufacture of long products such as a body of revolution used as seals, filters for cleaning liquids and gases, wicks of heat pipes and so on.

A known method of manufacturing porous products from non-woven wire material (AS No. 997931; IPC ³ B21F 21/00; publ. 02/23/1983, bull. No. 7), including the formation of a workpiece by laying with mutual crossing of a spiral wound wire and subsequent cold compression of the workpiece. Laying of a spiral wire is carried out by tightly winding it on a cylindrical rod, and compression of the workpiece wound on the rod is carried out by longitudinal cold rolling for several passes between the rollers, while in the process of rolling the rod with the workpiece is rotated around the longitudinal axis.

The disadvantage of this method is the complexity of its implementation. In this way, it is difficult to achieve the stability of the properties of the obtained products due to the need to rotate the rod with the workpiece during compression of the workpiece by longitudinal cold rolling between the rollers. The complexity of the method has limited its application to the manufacture of single samples in laboratory conditions.

The closest analogue is a method of manufacturing parts from materials with an disordered structure and a mold for its implementation (RF patent No. 2262407; IPC B21F 45/00; B21F 21/00; B30B 15/02; publ. 20.10.2005). A method of manufacturing parts from materials with an disordered structure includes obtaining pieces of wire in the form of stretched spirals, forming a flat billet, folding it into a roll using a rod, placing the resulting rolled billet with a hole in the mold and pressing it in several transitions. At each transition, pressing is carried out in at least three directions perpendicular to the axis of symmetry of the hole of the rolled preform, with obtaining, after the first transition, the density of the preform close to the density of the finished part. In the manufacture of a part in the form of a body of revolution, pressing at each subsequent transition, with the exception of the last, is carried out with a force exceeding the pressing force at the previous transition, and the last pressing transition is conducted with a force equal to the pressing force at the previous transition, after each transition, a blank is obtained in the form bodies of revolution with at least three protrusions on the outer surface, each of which is formed by the intersection of adjacent faces of the polyhedron, and at subsequent pressing transitions, I am the second, the projections obtained in the previous passage are removed. The mold for the manufacture of parts from materials with an disordered structure contains a clip with a rod fixed in it and two punches and is additionally equipped with at least one punch, each of the punches is arranged to move in a direction perpendicular to the axis of symmetry of the rod, while the working end face of each of the punches is made in the form of a flat surface parallel to the axis of symmetry of the rod or at an angle to this axis, or a concave cylindrical surface with two edges at the edges, or of a conical surface with two edges on the edges, the said edges of the concave cylindrical and conical surfaces are made sharp or obtuse, the obtuse edges being formed by flat surfaces located in the same plane, and the axis of symmetry of the concave cylindrical and conical surfaces of each of the punches in one of its extreme positions coincides with the axis of symmetry of the rod.

A disadvantage of the known analogue is the inability to obtain tubular elements (TE) with a ratio of wall thickness to the length of the TE more than 100.

The objective of the group of inventions is the development of tubular elements of material MP with a ratio of wall thickness to a length of more than 100 with the same density along the entire length.

The technical result achieved by using the present inventions is that they provided:

- manufacture of parts from MP material with the same density along the entire length;

- simplification of the manufacturing technology of parts from MP material by combining several transitions of the same type;

- simplification of the design of the mold.

The technical result is achieved by the fact that

, где D_заг - диаметр исходной заготовки; d - внутренний диаметр ТЭ; П_ТЭ - пористость готового ТЭ; D_ТЭ - внешний диаметр ТЭ; П_заг - пористость исходной заготовки;- a method of manufacturing tubular elements of material MP includes obtaining pieces of wire in the form of stretched spirals, forming a workpiece in the form of a roll with a hole, placing the resulting workpiece in a mold and pressing it in several transitions. The pressing is carried out in two directions, perpendicular to the axis of symmetry of the hole of the rolled preform, to obtain after the first transition a tubular workpiece with two protrusions on the outer surface, at the second transition, the protrusions are removed to obtain a cylindrical element. The number of transitions is due to the density of the body of the manufactured part. The diameter of the initial workpiece for the tubular element is calculated by the formula $$D_{s\mathrm{but}g}=\sqrt{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="00000008.png"\; state="\{\{state\}\}">d</figure-callout>}}^2+\frac{\left(\mathrm{one}-P_{TE}\right)\times \left(D_{TE}^2-d^2\right)}{\mathrm{one}-P_{s\mathrm{but}g}}}$$

where D _zag is the diameter of the initial billet; d is the inner diameter of the fuel cell; P _TE - porosity of the finished TE; D _TE - the outer diameter of the TE; P _zag is the porosity of the initial billet;

- the mold for the manufacture of tubular elements made of MP material contains at least one clip for even and odd transitions, each clip contains a matrix consisting of two plates, tightened by means of pins, with a fixed mandrel fixed in it, two punches mounted to move in a direction perpendicular to the axis of the mandrel. The working end face of each of the punches is made in the form of a concave cylindrical surface and forms obtuse edges with the inner surfaces of the matrix plates of the holder for odd transitions, and sharp edges with the inner surfaces of the holder of the matrix plates for even transitions. The symmetry axis of the concave cylindrical surface of each of the punches in the extreme positions coincides with the axis of symmetry of the mandrel. The width of the cartridge punch for each subsequent transition is less than the width of the cartridge punch for the previous transition. The punches are made in the form of a brand. Concave cylindrical surfaces in the form of a groove are made on the working plane of the matrix plates, the axis of symmetry of which coincides with the axis of symmetry of the mandrel. Between the mating surfaces of the plates of the dies and punches installed restrictive plates.

The initial interlocking of the coils in the MP material preserves the shape of both the workpiece and the finished part. This property of the MP material allows you to transfer parts from one cage to another for a subsequent transition.

The accumulation of material (spiral) for the tubular element of MP is carried out in the radial direction due to the wall thickness. The blank is in the form of a thick-walled pipe. The compaction of the MP material is carried out by pressing the outer diameter of the workpiece.

The proposed method for the manufacture of tubular elements (TE) from the material MP consists in bilateral radial pressing. Pressing is performed in one or more paired transitions. At the first transition (if necessary, subsequent odd transitions) receive a tubular workpiece with two protrusions on the outer surface. At the second transition (if necessary, even further transitions), the protrusions are removed, receiving a cylindrical FC. The number of transitions is due to the density of the body of the manufactured part. The number of transitions is selected based on the porosity of the finished fuel cell.

The group of inventions is illustrated by drawings. In FIG. 1 shows a clip for the first (as well as each odd) transition, FIG. 2 - clip for the second (as well as each even) transition, in FIG. 3 - initial blank, in FIG. 4 - intermediate preform, in FIG. 5 - finished part; where 1 is the mandrel, 2 is the punch, 3 is the matrix plate, 4 is the tie pin, 5 is the restriction plate, 6 is the workpiece.

To implement this method, a mold was designed. The mold includes a set of clips (Fig. 1 and Fig. 2). Each of the cages contains a matrix consisting of two plates 3, a fixed mandrel 1, two punches 2, movable in a direction perpendicular to the axis of the mandrel 1. The working end of each of the punches 2 is made in the form of a concave cylindrical surface with obtuse (in the holder for odd transitions) , or sharp (in a clip for even transitions) edges. To increase rigidity, the punches 2 are made in the form of a brand.

To compensate for the lateral pressure effect on the matrix plates 3, tie rods 4 are introduced into the cage design. The number of studs 4 is determined by the length of the obtained TE.

The accuracy of the working stroke of the punches 2 is provided using restrictive plates 6, the height of which is calculated for each transition, depending on the intermediate value of the thickness of the wall of the FC and the value of the elastic aftereffect of the material. Elastic aftereffect - the linear expansion of the elastic material after it is removed from the mold.

The magnitude of the elastic aftereffect depends on the grade of the starting material and on the intermediate value of the porosity of the fuel cell; it is determined during trial pressing.

On the working plane of the matrix plates 3, concave cylindrical surfaces are made in the form of a groove, the axis of symmetry of which coincides with the axis of symmetry of the mandrel 1. The diameter of the cylindrical groove and its depth are calculated for each transition depending on the intermediate value of the diameter of the FC.

As an example of the implementation of the claimed group of inventions, TEs were produced with porosity P = 50%, 300 mm long, 14.4 mm in diameter, 1 mm thick, made of X20H80 GOST 8803-89 nichrome wire.

The mass of TE was calculated by the formula Q = (1-P) × γ × V; where Q is the mass, g; P - porosity of the part, P = 0.5; γ is the density of the material of the wire, γ = 8.35 g / cm ³ ; V is the volume of the part, V = 14.14 cm ² ; Q = 59 g.

The blank 6 in the form of a roll was mounted in a holder for an odd transition (Fig. 1) with punches 2 with blunt edges. Pressing was carried out until the stroke of punch 2 was limited. An intermediate blank (Fig. 4) of a cylindrical shape with two protrusions along the generatrix was obtained. Next, the intermediate blank 6 was installed in the cage for an even transition (Fig. 2), with punches 2 with sharp edges. Pressing was carried out until the stroke of punch 2 was limited. An intermediate blank 6 of a cylindrical shape was obtained. Similarly, subsequent transitions were carried out to obtain a FC (Fig. 5) of a given porosity (6 transitions were required to obtain a FC with a porosity of 50%).

The calculation of the executive dimensions of the mold holders for the transitions was carried out:

1) The strokes of the punch on the transitions are selected based on the condition Δ = 0.45 ... 0.65 × t; where Δ is the stroke of the punch, mm; t is the wall thickness of the original billet, mm;

2) The diameter of the groove of the punch D _p = D _zag -2 × Δ; where D _zag is the diameter of the initial billet, mm;

3) The width of the groove of the punch s _p = D _p × sin45 °, where D _p is the diameter of the groove of the punch;

;4) Punch groove height $$h_P=\frac{D_P-\sqrt{{\mathrm{<figure-callout\; id="2"\; label="D\; P"\; filenames="00000008.png"\; state="\{\{state\}\}">D\; </figure-callout>}}_P^{}+s_{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="00000008.png"\; state="\{\{state\}\}">P</figure-callout>}}^2}}{2}$$

;

5) The diameter of the wall groove D _st is equal to the diameter of the groove of the punch at the previous transition;

6) The width of the grooves of the wall S _article = s _p ;

;7) The height of the groove wall $$h_{\mathrm{from}t}=\frac{D_{\mathrm{from}t}-\sqrt{D_{\mathrm{from}\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="00000008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+s_{\mathrm{from}\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="00000008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}}{2}$$

;

.8) Punch width $$S=\sqrt{D_{\mathrm{from}t}^2-s_{\mathrm{from}\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="00000008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}$$

.

The results of calculating the executive dimensions of the mold holders are shown in table 1.

The proposed invention made it possible to obtain a FC with a ratio of wall thickness to a length of more than 100 from MP material and to ensure the manufacture of parts with the same density along the length.

Claims (6)

1. A method of manufacturing tubular elements from metal rubber, comprising obtaining pieces of wire in the form of stretched spirals, forming an initial preform in the form of a roll with a hole, placing the resulting initial preform in a mold and pressing it in at least two transitions, characterized in that it is pressing carried out in two directions perpendicular to the axis of symmetry of the hole of the original billet with obtaining after the first transition of the tubular billet with two protrusions on the outer surface, while on the second the transition protrusions are removed to obtain a cylindrical element. 2. The method according to p. 1, characterized in that the number of transitions is due to the density of the body of the manufactured parts. 3. The method according to p. 1, characterized in that the diameter of the initial billet for the tubular element is calculated by the formula

where D _zag is the diameter of the initial billet;
d is the inner diameter of the tubular element;
P _TE - porosity of the finished tubular element;
D _TE - the outer diameter of the tubular element;
P _zag is the porosity of the initial billet. 4. A mold for the manufacture of tubular elements from metal rubber, containing at least one ferrule for an even transition and at least one ferrule for an odd transition, each of the ferrules contains a matrix consisting of two plates tightened by means of pins, secured in it a stationary mandrel, two pairs of punches installed with the possibility of movement in the direction perpendicular to the axis of the mandrel, the working end of each of the punches is made in the form of a concave cylindrical surface and forms with internal the edges of the cage matrix plates for an odd transition have obtuse edges, and with the inner surfaces of the cage matrix plates for an even transition there are sharp edges, while the width of the cartridge punch for each subsequent transition is less than the width of the cartridge punch for the previous transition, and between the mating surfaces of the matrix plates and punches restrictive plates, and the axis of symmetry of the concave cylindrical surface of the punches in extreme positions coincides with the axis of symmetry of the mandrel. 5. The mold according to claim 4, characterized in that the punches are made in the form of a brand. 6. The mold according to claim 4, characterized in that concave cylindrical surfaces in the form of a gutter are made on the working plane of the matrix plates.

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