RU2274508C1 - Method for forming double-flange sleeves - Google Patents

Abstract

FIELD: plastic working of metals, possibly forging shops of metallurgical and machine engineering factories at making automobile wheels and similar products.

SUBSTANCE: method comprises steps of preparing initial blank by hot die forging; forming intermediate semi-finished product in the form of cup with wall passing to its bottom and with front rim in bottom zone and back rim near free end of cup; calibrating received intermediate semi-finished product according to final size between rims due to changing cup depth at applying deforming effort along axis of sleeve to back rim or to near-bottom portion of sleeve and fixing other of said two portions. Then calibrated semi-finished product is subjected to heat treatment and mechanical working.

EFFECT: possibility for producing semi-finished products of wheels with different distances between rims due to using universal fitting that needs only minimized tuning.

5 cl, 2 dwg, 4 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 glasses with two flanges (automobile wheels), including processing by hot rolling (rolling) of the initial billet with the formation of an intermediate semi-finished product in the form of a bowl with a wall that goes into the bottom, as well as the front flange in the area of the bottom and rear flange at the free end of the bowl ( L. Golovanov, BBS Factory in Schiltach, Automotive Review, No. 1, 2008, p. 2).

The disadvantages of this method are the relatively low strength characteristics of the finished wheels.

A known method of manufacturing glasses with two flanges, mainly automobile wheels, including preparing the initial billet, forming a hot forging intermediate intermediate product in the form of a bowl with a wall that goes into the bottom, as well as the front flanges in the bottom and rear flanges at the free end of the bowl, heat treatment and machining (see RF patent No. 2063837, class. In 21 To 1/28, publ. 1996 - prototype).

The disadvantages of this method are the high unit cost (per wheel) of specialized die tooling for a particular wheel size in the manufacture of small batches, as well as significant labor costs when switching to other wheels. Technological preparation of the production of wheels in this way takes a lot of time.

The proposed method for the manufacture of glasses with two flanges, mainly automobile wheels, involves preparing the initial billet and forming an intermediate semi-finished product by hot stamping in the form of a bowl with a wall turning into the bottom, as well as the front flange in the zone of the bottom and rear flange at the free end of the bowl. Then the semi-finished product is calibrated for the final size of the distance between the flanges by changing the depth of the bowl, applying a deforming force along the axis of the glass to one of the elements of the pair: the back flange is the part of the glass in the area of its bottom and holding the other element of the said pair motionless.

The distance between the flanges can be reduced by applying a compressive force to the rear flange and holding the glass part in the zone of its bottom motionless, or increase by applying a tensile force to the glass part in the zone of its bottom and holding the back flange motionless.

After the said calibration, the bottom of the glass may be minted. Then conduct heat treatment and machining.

The proposed method differs from the prototype in that the semi-finished product is calibrated for the final size of the distance between the flanges by changing the depth of the bowl, applying a deforming force along the axis of the glass to one of the elements of the pair: the rear flange is part of the glass in the area of its bottom and holding the other element of the said pair motionless.

The distance between the flanges is reduced by applying a compressive force to the rear flange and holding the glass part in the zone of its bottom motionless, or increases by applying a tensile force to the glass part in the zone of its bottom and holding the back flange motionless. After the said calibration, the bottom of the glass may be minted.

The technical result of the invention is the possibility of group processing of geometrically similar wheels in a universal tooling, suitable for both reducing and increasing the distance between flanges with minimal readjustment within the framework of the concept of "flexible" production.

The invention is illustrated by drawings, which show the relative position of the semi-finished product and the parts of the tool: on the left - before calibration, on the right - upon completion.

Figure 1 - reducing the distance between the flanges;

figure 2 is an increase in the distance between the flanges.

The prepared initial cylindrical billet (not shown) is hot-formed by deformation to form an intermediate semi-finished product in the form of a bowl with a wall 1 passing into the bottom 2, as well as the front flange 3 in the zone of the bottom 2 and rear flange 4 at the free end 5 of the bowl.

Equipment for calibration by compression of the semi-finished product (figure 1) includes two half rings 6 and 7, placed in a round mandrel 8. The latter is mounted with the possibility of axial movement in the vertical hole of the rack 9, mounted on the table 10 of the press. An elastic element 11 is connected with parts 8 and 9. The axial movement of the mandrel 8 is limited by a stop 12. A support plate 13 is fixed on the table 10 with an opening 14 for the passage of the ejector 15. A calibration punch with a cylindrical 17 and conical 18 sections is fixed on the press slide 16. A round cage 19 of the Central hole covers the cylindrical section 17 of the punch. The clip 19 is fixed to the slider 16 through the distance ring 20.

Calibration by compression of the semi-finished product is as follows. Push table 10 press. The semi-finished product in the form of a bowl with a wall 1, bottom 2 and flanges 3 and 4 is lowered into the opening of the mandrel 8 about half the height of the semi-finished product. From two sides they move horizontally to the closure of the semirings 6 and 7 with the coverage of the wall 1 and lower them into the mandrel 8. After that, completely lower the semifinished product until the flanges 4 touch with the semirings 6 and 7. Moreover, between the end face of the semifinished product from its bottom 2 side and facing prefabricated surface of the plate 13 provides a gap Δ ₁ .

Table 10 is moved to the working position. When lowering the slider 16 down, the surface 21 of the cage 19 presses the end 5 of the flange 4 to the half rings 6 and 7. The axial force acts on the flange 4, the semi-finished product moves down. The elastic element 11 is deformed. With further lowering of the slider 16, the selection of the gap Δ ₁ and the emphasis of a part of the glass in the area of its bottom in the plate 13, the distance between the flanges 3 and 4 decreases by reducing the depth of the bowl, since the part of the glass in the area of its bottom is stationary, and to the rear flange 4 through the surface 19, a compressive deformation force is transmitted.

Depth of the bowl before calibration H ₁ , after - H ₂ , and H ₁ > H ₂ . In this case, the inner surface of the wall 1 rests on the conical portion 18 of the punch.

The decrease in the distance between the flanges 3 and 4 is accompanied by a thickening of the wall 1.

The distance between the flanges before calibration is K ₁ , after - K ₂ , and K ₁ > K ₂ .

The wall thickness before calibration is S ₁ , after - S ₂ , and S ₁ <S ₂ .

The calibration process can be completed before the end face 22 of the punch touches the bottom 2. If you lower the punch further, then when you touch the end 22 with the inner surface of the bottom 2, the embossing process begins with the final design of the relief of the bottom 2.

Equipment for tensile calibration of the semi-finished product (figure 2) contains the same elements as described previously. Only instead of the elastic element 11 and the abutment 12, a distance ring 23 is installed. The mandrel 8 is mounted on the column 9 through the ring 23. On the slider, instead of the distance ring 20, an elastic element 24 is mounted, articulated with the slide 16 and the clip 19. The clip is mounted with the possibility of axial movement relative to the slide 16 on a cylindrical portion 17 of the punch limited by a stop 25.

The tensile calibration of the semi-finished product is as follows. The semi-finished product is loaded into a tensile calibration tool as described above. In this case, a gap Δ _{2 is} provided between the bottom 2 and the surface of the plate. When lowering the slider 16, the surface 21 of the cage 19 presses the end 5 of the flange 4 to the half rings 6 and 7, ensuring its immobility.

The elastic element 24 is deformed. Further lowering of the slider 16 is accompanied by its relative movement relative to the stationary holder 19. The punch with its end 22 touches the bottom 2 of the semi-finished product and, lowering, increases the distance between the flanges 3 and 4 by increasing the depth of the bowl, since the rear flange 4 is fixed, and to the bottom 2 through the end 22, a tensile deformation force is transmitted.

The depth of the bowl before calibration is H ₃ , after - H ₄ , and H ₃ <H ₄ . In this case, the inner surface of the wall 1 tightens the conical portion 18 of the punch.

An increase in the distance between the flanges is accompanied by a thinning of the wall 1. The distance between the flanges before calibration is K ₃ , after - K ₄ , and K ₃ <K ₄ .

The wall thickness before calibration is S ₃ , after - S ₄ , and S ₃ > S ₄ .

The calibration process can be completed before the bottom 2 touches the plate 13. If the punch is lowered further, the gap Δ ₂ is selected and when touching the bottom 2 with the plate 13, the embossing process begins with the final design of the relief of the bottom 2.

The calibration process, both compression and stretching, can be performed more than once.

The calibrated semi-finished product was removed from the snap-in for calibration by both compression and tension as follows.

The slider moved the punch upward, removing it from the semi-finished product. The latter was lifted by the pusher so that the front flange 3 pushed the semicircles 6 and 7 out of the mandrel 8, since the movement of the latter was limited either by securing it to the stand 9 (Fig. 1) or by the stop 12 (Fig. 2).

Half rings 6 and 7 were separated from the semi-finished product. Then, the semi-finished product was lowered by moving down the ejector until the semi-finished product was laid on the plate 13.

Table 10 was pulled out of the press working area and the calibrated semi-finished product was removed from the tooling.

Examples of the method.

Example 1

A cylindrical billet of aluminum alloy 6061 is converted into an intermediate semi-finished product of a 7.5 × 17 "wheel in the form of a conical bowl with a bottom 2, a flange (front flange 3) in the bottom zone, a conical wall 1 for the rim and a second flange using one of the known methods of hot forging (rear flange 4) at the free end of the bowl. The total height of the bowl h ₁ = 220 mm

The diameter of the flanges is D = 478 mm. Wall thickness S ₁ = 12 mm. The angle α of the wall taper is variable from 1 to 3 °.

The semifinished product was heated and installed as described above into a snap calibration tool. The semi-finished product was deformed with an average degree of deformation of 17% to a size of h ₂ = 182.4 mm, which corresponds to a wheel size of 6 × 17 ". During the upsetting process, wall 1 begins to lean on the conical portion of the punch 18, maintaining stability and acquiring the shape of the latter on the inner surface.

After calibration, the bottom of the semi-finished product was minted with a punch on the plate 10.

Subsequently, complete thermal and mechanical processing was performed to obtain a 6 × 17 "wheel.

Example 2

For particularly precise products, for example, high-speed wheels for sports of the highest achievements, the compression calibration process for the same semi-finished product was divided into stages:

a) preliminary - with a degree of deformation of ~ (14-16)%;

b) final - with a degree of deformation of ~ (0.5-3)% in a freshly quenched state, followed by final heat treatment (aging).

Subsequently, machining was performed to obtain the same 6 × 17 ″ wheel.

This process option dramatically reduces the value of residual stresses, which eliminates warping of the finished wheel.

Example 3

An intermediate semi-finished wheel 6 × 17 "in the form of a bowl with an inner diameter at the rear flange of 4 d = 420 mm and a taper angle of the wall α = 4 ° was made from a magnesium alloy of type AZ80 A similar to that described in Example 1. The wall thickness S ₃ = 15 mm and total bowl height h ₃ = 190 mm.

The semifinished product was heated and installed as described above into a tensile calibration tool. The semi-finished product was deformed to a final size of h ₄ = 237 mm, which corresponded to the size of the finished wheel 8 × 17 ".

In this case, the average degree of deformation along the height of the bowl was ~ 25%, and the actual along the wall ~ 31%.

In the process of stretching, the wall 1 of the bowl covered the conical portion 18 of the punch, acquiring the shape of the punch on the inner surface of the wall, that is, preventing distortion of the geometric shape of the wall.

Example 4

Similar to the semi-finished product described in example 3, but from the less ductile magnesium alloy MA14. The size and shape of the punch and half rings 6 and 7 were chosen such that after the contact of the end face 22 of the punch with the bottom 2 of the semi-finished product, the semi-finished product was radially pinched between the surface of the conical section 18 and the inner surface of the half rings 6 and 7, first according to the maximum diameter of the punch and with further lowering of the punch to the force wall tension, shear is added as the wall 1 is pulled over the cone section 18. Such a deformation scheme made it possible to significantly optimize the calibration process and obtain a calibrated semifinished product of the same size as in example 3.

Thus, the proposed method allows, within the framework of the concept of "flexible" production, to calibrate the "universal" semi-finished wheels for various distances between flanges, that is, a wide range of wheel sizes can be obtained by group processing. This is especially significant for the production of prototypes and small (pre-production) batches of automobile wheels made of aluminum and magnesium alloys by hot volumetric stamping with a structure that provides optimal wheel strength characteristics under conditions of dynamic loading during operation.

Claims (5)

1. A method of manufacturing glasses with two flanges, mainly automobile wheels, including preparing the initial billet, forming an intermediate semi-finished product by hot stamping in the form of a bowl with a wall turning into the bottom, as well as a front flange in the bottom zone and a rear flange at the free end of the bowl, heat treatment and machining, characterized in that the semi-finished product is calibrated to the final size of the distance between the flanges by applying a deforming force along the axis of the glass to one of the elements p ara rear flange - part of the glass in the area of its bottom and holding another element of the said pair motionless with a change in the depth of the bowl. 2. The method according to claim 1, characterized in that the distance between the flanges is reduced by applying a compressive force to the rear flange and holding a part of the glass in the zone of its bottom motionless. 3. The method according to claim 1, characterized in that the distance between the flanges is increased by applying tensile forces to a part of the glass in the area of its bottom and holding the rear flanges motionless. 4. The method according to claim 1, characterized in that after the said calibration, the bottom of the glass is minted. 5. The method according to claim 1, characterized in that the semi-finished product is calibrated more than once.

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