RU2250150C1 - Method for making double-flange bushings - Google Patents

Abstract

FIELD: plastic working of metals, possibly in forging shops of metallurgical and machine engineering plants for manufacturing automobile wheels and similar products.

SUBSTANCE: method comprises steps of preparing initial blank; forming of it intermediate semi-finished product in the form of cup having shaped bottom, wall and in zone of transition of wall to bottom - thickened portion defined at inner side of cup by surface of revolution, by annular protrusion on outer end of bottom and by flange on end of wall; making central protrusion on inner end of bottom; forming flange on wall by applying axial effort to its end for increasing thickness of wall having constant diametrical size at inner side; then finally shaping blank due to expanding annular protrusion on bottom of cup for forming other flange. Blank is finally shaped during two stages. At first stage height of central protrusion of bottom is increased due to radial motion of bottom material from its center and simultaneously thickness of said protrusion and diametrical size of bottom with flange are decreased, part of wall adjoined to bottom is thickened. At second stage sleeve is calibrated from inside for achieving final diametrical size of its cavity. Then bushings are subjected to heat treatment and mechanical working.

EFFECT: enhanced strength characteristics of reduced-cost wheels.

3 cl, 3 dwg, 2 ex

Description

The present invention relates to the field of metal forming and can be used in forge shops of metallurgical and engineering plants in the manufacture of automobile wheels and the like.

A known method of manufacturing products such as wheels, including the preparation of the original billet, the formation of the intermediate semi-finished product in the form of a bowl, the formation of an annular protrusion and a process on the bottom of the bowl, molding on the bowl of the flange and the disk part with a relief, the formation of the rim and other flanges from the ring ledge, as well as thermal and machining (RF Patent No. 2063838, class B 21 K 1/28, publ. 1996).

The disadvantage of this method is the complexity of the die tooling, as well as low productivity due to the need to perform a large number of technological transitions of pressure treatment.

A known method of manufacturing glasses with two flanges, for example automobile wheels, comprising preparing the initial billet, forming an intermediate semi-finished product in the form of a bowl with a shaped bottom, wall, thickening when the wall goes into the bottom, the rotation surface bounded on the inside of the bowl, an annular protrusion on the outer end of the bottom and a flange at the end of the wall, the final formation of the workpiece, including the distribution of the annular protrusion at the bottom of the bowl into another flange, heat treatment and machining (RF Patent No. 2135320, class . In 21 K 1/28, publ. 1999 - prototype).

The disadvantage of this method is the difficulty in ensuring the desired quality of the finished product due to the insufficiently rational structure of the fibers during deformation, which impairs the strength characteristics under cyclic loading during operation, as well as the narrow specialization of the resulting blanks, which significantly increases the cost of manufacturing small batches of wheels. The latter is most important for sports car wheels, the shape and dimensions of which are strictly individualized in accordance with the requirements of each customer.

The proposed method for the manufacture of glasses with two flanges, for example, automobile wheels, involves preparing the initial billet and forming an intermediate semi-finished product in the form of a bowl with a shaped bottom, wall, thickening when the wall goes into the bottom, the rotation surface bounded on the inside of the bowl, an annular protrusion on the outer end of the bottom and a flange at the end of the wall. Then, the workpiece is finally formed by distributing an annular protrusion at the bottom of the bowl into another flange. When forming an intermediate semi-finished product on the inner end of the bottom perform a Central protrusion. A flange on the wall is formed by applying axial force to its end, by increasing the wall thickness at the end with its constant diametrical dimensions on the inside. The final formation of the workpiece is carried out in two stages. At the first stage, the height of the said central protrusion at the bottom is increased with a decrease in the thickness of the latter, and the diametrical dimensions of the bottom with its flange, said bulge and adjacent to the last part of the wall are increased by radial movement of the bottom material from its center. At the second stage, the glass is calibrated by distributing the glass from the inside to the final diametrical dimensions of its cavity. Steps one and two may be repeated in the same sequence. The height of the Central protrusion and the thickness of the bottom are determined by the relations:

и

and

, где

where

h ₁ and h ₂ - the height of the Central ledge,

H ₁ and H ₂ - the thickness of the bottom,

respectively, the intermediate semi-finished product and the final formed workpiece. Then they conduct heat treatment and machining.

The proposed method differs from the prototype in that when forming an intermediate semi-finished product on the inner end of the bottom, a central protrusion is performed, a flange on the wall is formed by applying axial force to its end, by increasing the wall thickness at the end with its constant diametrical dimensions on the inside, and the final formation the blanks are carried out in two stages: at the first, they increase the height of the mentioned central protrusion at the bottom while reducing the thickness of the latter, and also increase the diametrical dimensions of the bottom with its flange, said bead and the adjacent wall part to the latter by radial displacement of bottom material from its center, and the second - calibrated distribution inside the glass on the end diametrical dimensions of its cavity.

In this case, the stages of the final formation of the workpiece can be repeated in the same sequence. The height of the Central protrusion and the thickness of the bottom are determined by the relations:

и

and

h ₁ and h ₂ - the height of the Central ledge,

H ₁ and H ₂ - the thickness of the bottom,

respectively, the intermediate semi-finished product and the final formed workpiece.

The technical result of the invention is the possibility of batch processing of geometrically close wheels with a rational structure of the fibers during deformation, which allows combining high strength characteristics under cyclic loading in extreme conditions and low cost of wheels. This is especially significant in the manufacture of small batches of sports wheels with a thin bottom relative to the wall thickness.

The invention is illustrated in the drawing, which shows:

figure 1 - the formation of the intermediate semi-finished product;

figure 2 - the first stage of the final formation of the glass;

figure 3 - the second stage of the final formation of the glass.

Example.

A sports wheel with dimensions 13 ’’ × 21 ’’ was manufactured from aluminum alloy of type 6061. The initial billet 1 with dimensions of ⌀500 mm × 125 mm and a mass of 66 kg was heated and fit into the die cavity 2 with a shaped ejector 3 and punch 4.

A deforming force was applied and backward extrusion formed a semi-finished product in the form of a bowl with a height of H = 400 mm, an outer diameter of D ₁ = 505 mm and a wall thickness of 5S = 10 m. At the same time, since the axial force acted on the open end of the bowl, flange 6 was formed by increasing the thickness wall 5 at the end to S _f = 25 mm, keeping the inner diameter D ₂ constant. In this case, an annular protrusion 7 was formed on the outer surface of the bottom part. The transition zone from the bottom 8 to the wall 5 was made thickened. The thickening 9 from the inside is bounded by a conical surface with a taper angle α = 32 °, the shape and dimensions of which are determined by the conical part 10 of the punch 4. The conical angle of the surface of the annular protrusion β = 7 °. At the end of the punch 4, a cavity 11 is made, forming a central protrusion 12.

The final formation of the wheel blank was carried out in two stages. First, the calibration punch 13 began to distribute the flange 6, then formed the flange 14 of the annular protrusion 7 with a partial flow of the workpiece material into the cavity 15 of the punch 13, transforming the central protrusion 12 into a more massive protrusion 16. Then the entire bottom part of the glass was deformed, ending the movement of the workpiece material into the protrusion 16 and creating its intense flow from the bottom center in the radial direction to the periphery, which not only contributed to the formation of the flange 14, but also increased the diametrical dimensions of the stack wall itself and near its bottom to the D ₃ = 530 mm. The wall 5 thus lagged behind the punch 13 with the formation of an annular gap 17.

Subsequently, the second stage of the final formation of the wheel blank was carried out, changing the calibration punch 13 to the punch 18 of large diametric dimensions, the shape of the cup was calibrated from the inside, increasing the flange 6 to a diameter D ₄ = 574 mm, equal to the diameter of the flange of the wheel 21 ''. At the same time, the bottom part was deformed, increasing the dimensions of the flange 14 also to a diameter of D ₄ = 574 mm. At the same time, the transition zone from the flange 14 to the wall 5 retained diametric dimensions close to those after the first calibration. The height of the central protrusion 12 h ₁ = 40 mm was increased to the height of the protrusion 16 h ₂ = 70 mm, and the thickness of the bottom 8 was reduced from a thickness of H ₁ = 25 mm to a thickness of H ₂ = 16 mm.

Thus, using a minimum amount of die tooling and a minimum press force, a relatively large size workpiece was obtained. From a semi-finished product with a maximum diameter of D ₁ + 2S _f = 535 mm and a projection area of F ₅₃₅ = 2247 cm ² , a wheel blank was obtained with a maximum diameter of D ₄ = 574 mm and a projection area of F ₅₇₄ = 2586 cm ² , which is 15% more than the semi-finished product.

Example 2

For the manufacture of a new workpiece for the 13 '' × 21 '' wheel blank obtained in Example 1, the new blank for the 13 '' × 22 '' wheel was repeated both stages of final shaping similarly to the previously described in example 1, but with larger punches, namely, in the first stage final shaping continued to increase the height of the Central protrusion 16 and reduce the thickness of the bottom 8.

At the same time, flange 6 was additionally distributed and the diameter of flange 14 was increased with a simultaneous increase in the diametrical dimensions of the glass wall 5.

In this example, completing the final shaping, the next punch increased the diameter D _{4 of the} flange 6 to 600 mm, increased the height h _{2 of the} central protrusion to 74 mm and reduced the thickness H _{2 of the} bottom to 15 mm, increasing the diameter D _{4 of the} flange 14 also to 600 mm.

Thus, a blank was obtained with a projection area of F = 2826 cm ² , i.e. In total, the area of the workpiece was increased by more than 25% of the original.

The proposed method allows to significantly expand the range and improve the quality of finished products due to the rationalization of die tooling and, as a result, improving the structure of the fibers during deformation and preventing cracking during the formation of flanges. The latter is especially significant in the manufacture of products from alloys of the magnesium-lithium system.

Claims (3)

1. A method of manufacturing glasses with two flanges, for example, automobile wheels, comprising preparing the initial billet, forming an intermediate semi-finished product in the form of a bowl with a shaped bottom, wall, thickening when the wall goes into the bottom, the rotation surface bounded on the inside of the bowl, an annular protrusion on the outside the bottom end and the flange at the end of the wall, the final formation of the workpiece, including the distribution of the annular protrusion at the bottom of the bowl into another flange, heat treatment and machining, characterized in that when the formation of the intermediate semi-finished product on the inner end of the bottom perform a Central protrusion, the flange on the wall is formed by applying axial force to its end, by increasing the wall thickness at the end with its constant diametrical dimensions on the inside, and the final formation of the workpiece is carried out in two stages: at the first increase the height of the said central protrusion at the bottom with a decrease in the thickness of the latter, and also increase the diametrical dimensions of the bottom with its flange, the aforementioned thickening and adjacent to the last Tew wall by radial displacement of bottom material from its center, and the second calibrated distribution inside the glass on the end diametrical dimensions of its cavity. 2. The method according to claim 1, characterized in that the stages of the final formation of the workpiece are repeated in the same sequence. 3. The method according to claim 1, characterized in that the height of the Central protrusion and the thickness of the bottom is determined from the ratios:

where h ₁ and h ₂ - the height of the Central protrusion, respectively, of the intermediate semi-finished product and the final formed workpiece; H ₁ and H ₂ - the bottom thickness, respectively, of the intermediate semi-finished product and the final formed workpiece.

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