RU2538129C1 - Method of radial forging - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: multipass reversing radial forging is performed by two mutually perpendicular pairs of two-start flat dies. Squeezing deformation zone is formed in every pass along forging axis and aligned with gaging zone as well as deformation gaging zone is formed. Deformation zones formed by one pair of flat dies are located along forging zone in staggered order relative to deformation zones formed by another pair of flat dies. Every pair of flat dies produces at the workpiece an extra gaging zone to be located between said aligned zone and gaging zone.

EFFECT: ingot is straightened by bending in two mutually perpendicular planes, higher quality of produced work pieces.

8 dwg

Description

The invention relates to the processing of metals by pressure, and in particular to methods of radial forging.

There is a method of multi-pass reversible radial forging simultaneously by two mutually perpendicular pairs of two-way strikers. Kovtenyuk, I.A. Pospelov et al. Mastering the technology of radial forging of strips made of steel DI-32 // Forging and stamping. 1986, No. 12. C.2-3 /, used to obtain strip blanks (hereinafter we will call them simply blank).

In this method, on the workpiece, one pair of dies during forging in each pass forms two deformation zones - crimp combined with calibrating and calibrating, and the other pair of dies one deformation zone - crimping combined with calibrating. The use of such a deformation scheme of the workpiece helps to reduce its curvature (crescent) formed due to asymmetric deformation conditions. The curvature (crescent) of the workpiece is reduced by straightening by bending due to its retention by frictional forces of a pair of strikers forming one deformation zone, and simultaneous impact on it in the perpendicular plane by a pair of strikers forming two deformation zones. Due to this, the workpiece is exposed at three points, which leads to the action on the workpiece in the plane of formation of two bending moment deformation zones on it. This helps to reduce the curvature (crescent) of the resulting workpiece. Moreover, the deformation zones formed by one pair of strikers are staggered on the workpiece in relation to the deformation zone formed by another pair of strikers.

The disadvantage of this method is the effect on the workpiece of bending moment, leading to a decrease in its curvature, in only one plane. In this case, editing in the plane of action on the workpiece of two deformation zones is not carried out in full due to the fact that the workpiece is held by the dies, forming one deformation zone, only by friction between the workpiece and the working surface of these dies. Because of this, the workpiece can be displaced from the forging axis along the working surface of these strikers in the direction of one of the strikers, forming two deformation zones, which violates the three-point dressing scheme necessary, as is known, for straightening by bending. This reduces the quality of the workpiece by the parameter of curvature. It should be noted that forging a curved workpiece in the next pass is almost impossible due to the stop of the front end of the workpiece in the end surface of the striker.

Thus, the disadvantage of this analogue is the ability to edit the workpiece in only one plane with its low quality, which does not ensure the quality of the resulting workpiece by the parameter of curvature.

Closest to the proposed solution in terms of technical nature and the achieved effect is a method of multi-pass reversible radial forging simultaneously by two mutually perpendicular pairs of two-way strikers / Forging on radial crimping machines. V.A. Tyurin, V.A. Lazorkin, I.A. Pospelov et al. - M.: Mechanical Engineering, 1990. - p.26 /, / Instruction manual. GFM GmbH, Austria, Ennserstr. 14, A-4403 Steyr, Austria. E-Mail: Office@gfm.at, Web: www.gfm.at/.

With this method of radial forging, each pair of strikers during forging forms two deformation zones in succession along the axis of the forging on the workpiece in each pass. The first deformation zone along the forging axis is a crimp combined with a calibrating one. The second deformation zone along the forging axis is a calibrating one. These deformation zones formed by one pair of strikers are staggered along the forging axis in relation to the deformation zones formed by another pair of strikers.

The use of this forging method simultaneously with the deformation of the workpiece allows the elimination of its curvature formed due to asymmetric conditions of deformation of the workpiece by straightening by bending in two mutually perpendicular planes.

However, in this way it is impossible to ensure the quality of editing. This is due to the fact that when editing a workpiece by bending in the same plane when two bending zones are affected by one deformation pair, its retention in the deformation zones formed by the second pair of dies is carried out only by friction between the workpiece and the working surface of these dies. In this regard, the workpiece can be displaced from the axis of the forging along the working surface of the second pair of strikers, which violates the required, as is known, three-support scheme for bending dressing. The task of the front end of the curved billet in the strikers in the next passage is almost impossible because of its emphasis on the end part of the striker.

Thus, the main disadvantage of this method is the low quality of the resulting blanks by the parameter of their curvature.

The objective of the invention is to improve the quality of the resulting blanks.

The problem is achieved in that in the inventive method of multi-pass reverse radial forging simultaneously by two mutually perpendicular pairs of two-shot strikers with the formation on the workpiece in each pass sequentially along the forging axis of the crimped deformation zones and calibrating deformation zones, in which the deformation zones formed by one pair strikers located along the forging axis in a checkerboard pattern with respect to the deformation zones formed by another pair of strikers, according to the invention, each giving a pair of strikers forms an additional calibrating deformation zone on the workpiece, which is located between the combined crimp with the calibrating deformation zone and the calibrating deformation zone.

The formation of an additional gauge deformation zone on the workpiece by each pair of strikers provides not only an increase in the quality of the geometric dimensions of the cross section of the workpiece, but also simultaneous deformation of the workpiece by editing it by bending in two mutually perpendicular planes when creating in each plane a three-support scheme necessary for editing by bending. This ensures an increase in the quality of the resulting blanks by the parameter of curvature.

The location of the additional calibrating deformation zone between the combined crimp with the calibrating deformation zone and the calibrating deformation zone during the deformation of each pair of strikers does not violate the reverse radial forging mode, in which the workpiece is deformed by two pairs of two-way strikers when it is moved in both forward and backward directions.

The location of additional calibrating zones, without violating the staggered order of their location on the workpiece, allows simultaneous deformation of the workpiece with two pairs of strikers without the possible formation of burrs (whiskers) on the workpiece between mutually perpendicular pairs of strikers.

Therefore, the method proposed according to the invention allows simultaneously reducing the size of the cross section of the workpiece by plastic deformation and straightening the workpiece by bending in two mutually perpendicular planes while providing forging of the workpiece by two mutually perpendicular pairs of strikers with its movement in the forward and reverse directions along the forging axis.

Thus, the application of the proposed method of radial forging can significantly improve the quality of the resulting workpieces.

The proposed method of radial forging is illustrated in the drawings.

Figure 1 shows a section aa along the forging axis onto a deformable workpiece, a longitudinal section of a pair of strikers located horizontally, strikers of a vertical pair and a deformation zone formed by a vertical pair of strikers in one passage.

Figure 2 shows a view of B on mutually perpendicular pairs of strikers and the cross section of the workpiece.

Figure 3 shows a rotated section BB along the forging axis onto a deformable workpiece, a longitudinal section of a pair of strikers located vertically, strikers of a horizontal pair and a deformation zone formed by a horizontal pair of strikers in one pass.

Figure 4 shows the workpiece along the axis of the forging with deformation zones formed by horizontal and vertical pairs of strikers in one pass.

Figure 5 shows a section GG along the axis of the forging on a deformable workpiece, a longitudinal section of a pair of strikers located horizontally, the strikers of a vertical pair and the deformation zone formed by a vertical pair of strikers in the next return passage.

Figure 6 shows a view of D on mutually perpendicular pairs of the strikers and the cross section of the workpiece in the next return passage.

7 shows a rotated section EE along the axis of the forging onto a deformable workpiece, a longitudinal section of a pair of strikers located vertically, strikers of a horizontal pair and a deformation zone formed by a horizontal pair of strikers in the next return passage.

On Fig shows the workpiece along the axis of the forging with deformation zones formed by horizontal and vertical pairs of strikers in the next return passage.

Using figure 1 ... 8 consider the technology of radial forging using the proposed method.

Radial forging is carried out by two pairs of mutually perpendicular two-way strikers (Figs. 1-3, 5-7). In this example, one pair of strikers 1 is located horizontally, the second pair of strikers 2 is located vertically. Each firing pin has three work surfaces. The two extreme working surfaces of each striker are made obliquely at an angle α to the forging axis and are designed to crimp the workpiece (to reduce its cross section). Next we will call them crimp surfaces. The working surfaces combined with them are made parallel to the forging axis. They are designed to calibrate the size of the cross section of the workpiece after it is deformed by the crimping surfaces and to move the workpiece in the forging direction along the forging axis. Below we will call these surfaces gauge. This arrangement of the working surfaces on the strikers allows the workpiece to be deformed both during direct and reverse movement of the workpiece, i.e. in reverse mode. Between the indicated working surfaces on the strikers of each pair, a third working surface is made parallel to the forging axis. It performs the functions of an additional calibrating surface, and also in the case of bending of the workpiece under asymmetric conditions of its deformation, it creates, together with two other working surfaces of the striker, a three-support editing scheme. To allow simultaneous deformation of the workpiece with two mutually perpendicular pairs of strikers, their design is made on the basis of the protrusion-groove. During the reciprocating movement of the strikers, the protrusions of one pair of strikers enter the grooves of the other pair of strikers.

Consider the process of deforming a workpiece in two passes.

The first passage is illustrated in figures 1-4. The second passage is illustrated in FIGS. 5-8.

In the first pass, the workpiece 3 of height H ₀ and width B ₀ is set into the strikers in the direction of forging along the forging axis and is deformed simultaneously by a pair of horizontal 1 and a pair of vertical strikers 2. The first crimping surfaces of the strikers 1 and 2 along the forging (Figs. 1-3) due to their reciprocating movement in the vertical and horizontal planes (shown by double horizontal and vertical arrows), the workpiece is compressed by the value Δh ₁₁ , Δh ₂₁ and its calibration. In this case, on the horizontal and vertical surfaces of the workpiece 3, three deformation zones are formed (Figs. 1, 3, 4). Vertical strikers 2 formed a combined crimp and gauge deformation zone with a length of l _obzh21 and l _k21 , _respectively , an additional calibrating deformation zone of length l _k2d and a calibrating deformation zone of length l _k22 (Figs. 1, 4). Horizontal strikers 1 form a combined crimp and gauge deformation zone with a length of l _obzh11 and l _k11 , _respectively , an additional calibrating deformation zone of length l _k1d and a calibrating deformation zone of length l _k12 (Figs. 3, 4). As a result of deformation in this passage, a workpiece 3 of height H ₁ and width B _{1 is} obtained.

To be able to implement forging simultaneously with two mutually perpendicular pairs of pins 1 and 2 without the formation of burrs in the case of non-known "rule inscribed shapes" crumple zone l _obzh21 length together with l _K21 and deformation zone length l _k2d and l _k22 formed by a vertical pair of strikers 2 are arranged in a checkerboard pattern with respect to a deformation zone of length l _obj11 together with l _k11 and deformation zones of length l _k1d and l _k12 formed by a horizontal pair of strikers 1 (Fig. 4).

When the resulting workpiece 3 is bent with a cross section H ₁ , B ₁ simultaneously with the deformation of the workpiece 3, it is straightened by bending in two planes by acting on the workpiece with forces P, P ₁ and P ₂ , at points b, a, c (Fig. 1) and at points e, f, d (figure 3). The shoulders of applying the forces P, P ₁ and P ₂ for dressing the workpiece are m and n.

In the second pass, the workpiece 3 of height H ₁ and width B ₁ is set into strikers in the forging direction along the forging axis and is deformed simultaneously by a pair of horizontal strikers 1 and a pair of vertical strikers 2. The first crimping surfaces of the strikers 1 and 2 along the forging (Figs. 5-7 ) due to their reciprocating movement in the vertical and horizontal planes (shown by double horizontal and vertical arrows), the workpiece is compressed by the value Δh ₁₂ , Δh ₂₂ and its calibration. Moreover, on the horizontal and vertical surfaces of the workpiece, three deformation zones are formed (Figs. 5, 7, 8). 2 is formed by vertical strikers combined clamp and calibrating deformation area length, respectively, l and l _{obzh22 k22,} additional calibrating deformation zone length l _k2d and calibrating deformation zone length l _K21 (5, 8). Horizontal strikers 1 form a combined crimp and gauge deformation zone with a length of respectively l _obj12 and l _k12 , an additional calibrating deformation zone of length l _k1d and a calibrating deformation zone of length l _k11 ( _Figs . 7, 8). As a result of deformation in this passage, a workpiece 3 of height H ₂ and width B _{2 is} obtained.

To be able to implement forging simultaneously with two mutually perpendicular pairs of pins 1 and 2 without the formation of burrs in the case of non-known "rule inscribed shapes" crumple zone l _obzh22 length together with l _k22 and deformation zone length l _k2d and l _K21 formed by a vertical pair of strikers 2, are arranged in a checkerboard pattern with respect to a deformation zone of length l _obj12 together with l _k12 and deformation zones of length l _k1d and l _k11 formed by a horizontal pair of strikers 1 (Fig. 8).

When the resulting workpiece 3 is bent with a cross section of H ₂ , B ₂ simultaneously with the deformation of the workpiece 3, it is straightened by bending in two planes by acting on the workpiece with forces P, P ₁ and P ₂ , at points b, a, c (Fig. 5) and at points e, f, d (Fig.7). The shoulders of applying the forces P, P ₁ and P ₂ for dressing the workpiece are m and n.

In the following passes, the forging and dressing processes are similar to the two passes described.

To carry out dressing of the workpiece without changing the cross section of the workpiece, the specific dressing forces of the ores acting on the contact surface unit of the additional calibrating section should not exceed the yield strength of the workpiece metal σ _t at the temperature of forging and dressing.

To fulfill this condition, a certain length of the additional calibrating section of the strikers is necessary.

The minimum length of the additional calibrating section of the strikers can be determined using the symbols shown in figures 1, 3, 5, 7, from the following known ratio / Machines and assemblies of metallurgical plants. In three volumes. T.3. Machines and assemblies for the production and decoration of rolled products. Textbook for high schools. A.I. Tselikov et al. - M.: Metallurgy, 1981. p.306 /, obtained from the condition of equal moments of external and internal forces when editing. Taking into account the need for excess of external forces over internal forces for making corrections and taking into account the difference in the reactions of forces P ₁ , P ₂ in a , c, f and d, this condition in the accepted notation will have the form

$$P\ge {\sigma }_T\times (m+n)\times W_P/(n+m),\left(\mathrm{one}\right)$$

where W _p - plastic moment of resistance of the cross section of the workpiece.

When editing the workpiece according to figures 1 and 5

$$W_P=0,25\times B_i\times {\mathrm{<figure-callout\; id="2"\; label="H\; i"\; filenames="00000009.png,00000010.png"\; state="\{\{state\}\}">H\; </figure-callout>}}_i^{}.\left(2\right)$$

When editing the workpiece according to figure 3 and 7

$$W_P=0,25\times B_i^2\times H_i^{}.\left(3\right)$$

The editing force, in turn, when editing according to figure 1, 5 is equal to

$$P=p_{\mathrm{at}d}\times Bi\times l_{\mathrm{to}\mathrm{one}d}.\left(\mathrm{four}\right)$$

The editing force when editing according to figure 3, 7 is equal to

$$P=p_{\mathrm{at}d}\times Hi\times l_{\mathrm{to}2d}.\left(5\right)$$

Substituting relations (2), (4) in (1) and (3), (5) in (1), and also assuming the equality p _beats = σ _T , after the transformations we obtain

$$l_{\mathrm{to}\mathrm{one}d}\ge 0,25(m+n){\mathrm{<figure-callout\; id="2"\; label="H\; i"\; filenames="00000009.png,00000010.png"\; state="\{\{state\}\}">H\; </figure-callout>}}_i^{}/(n+m),\left(6\right)$$

$$l_{\mathrm{to}2d}\ge 0,25(m+n){\mathrm{<figure-callout\; id="2"\; label="B\; i"\; filenames="00000009.png,00000010.png"\; state="\{\{state\}\}">B\; </figure-callout>}}_i^{}/(n+m).\left(7\right)$$

Thus, when implementing the proposed method, the cross-sectional area of the workpiece is reduced with its additional calibration and straightening by bending. This suggests that the application of the proposed method provides high quality blanks both in the geometric dimensions of the cross section and in the parameter of curvature.

Consider the implementation of the proposed method of radial forging on a radial forging machine (RCM) of the SKK-14 model of GFM, working at one of the enterprises in Chelyabinsk, when hot forging a square billet H ₂ = 40 mm, B ₂ = 40 mm from the original billet H ₀ = 60 mm, B ₀ = 60 mm. Material - tool steel quick cutting P18. The workpiece compression is adopted Δh ₁₁ = Δh ₂₁ = Δh ₁₂ = Δh ₂₂ = 10 mm Then H ₁ = 50 mm, B ₁ = 50 mm.

The following parameters of the strikers were adopted: α = 12 deg, l _k11 = l _k12 = l _k21 = lk ₂₂ = 16 mm. Taking into account the deformation conditions and the geometry of the strikers, m = 75 mm, n = 45 mm.

The minimum lengths of additional calibrating zones are determined using relations (6) and (7). After calculations, it was obtained for the first pass l _k1d = l _k2d ≥22.2 mm, for the second pass l _k1d = l _k2d ≥14.2 mm. To carry out dressing editing in two passes, the length of the additional calibrating zone should be taken, which ensures dressing of the workpiece without changing its cross section in excess of 22.2 mm. For practical implementation, the length of the additional calibrating zone is equal to 25 mm.

After the development of working drawings of the strikers with the accepted and calculated basic parameters, as well as their manufacture, the proposed radial forging method will be implemented in industrial conditions on a radial forging machine (RCM) of the SKK-14 model.

Claims (1)

 A multi-pass reversible radial forging method, comprising deforming a workpiece simultaneously with two mutually perpendicular pairs of two-way strikers with the formation on the workpiece in each pass sequentially along the forging axis of each pair of strikers of a crimp deformation zone combined with a calibrating and calibrating deformation zone, said deformation zones formed by one a pair of strikers located along the forging axis in a checkerboard pattern with respect to the deformation zones formed by another pair of strikers, characterized the fact that the deformation is carried out with the formation on the workpiece by each pair of strikers of an additional calibrating zone of deformation, which is located between the crimp zone combined with the calibrating and calibrating zone of deformation.

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