SU1630867A1 - Method of manufacturing ring-shaped forgings - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in the production of blanks for large-sized bearings, bandages and rings. The purpose of the invention is to increase the durability of a punch by reducing the required effort of deforming and locking the dies during punching and reducing consumption. metal by reducing the thickness of the otter. The weighed and deposited preform is placed in the cavity between the split dies of the closed die. When stamping is carried out in two stages, the workpiece is affected by the force of the punch. In the first stage, the locking force of the dies is complete in terms of technological need. The stage is completed with the value of underfilling of the sharp corners of the punch 0.05-0.1 of the outer radius of the forging and the thickness of the bridge under the punch of 0.2-0.3 of the height of the forging. The second stage is carried out with the same punching force, but the locking force of the dies is reduced until the otter thickness reaches 0.05-0.15 of the radius of the forging hole. The forging is then removed from the die, the otter is sprinkled, and rolling is carried out. The invention makes it possible to reduce the required deformation forces and locking of the dies and to reduce metal waste in the otter. 6 Il. Ј (/

Description

The invention relates to the processing of metals by pressure, in particular to methods for manufacturing large-sized ring forgings using stamping in closed dies, and can be used in workshops of metallurgical plants engaged in the production of blanks for large-size bearings, tires and rings using rolling.

The purpose of the invention is to increase the durability of the punch by reducing the required deformation efforts and locking the dies during punching and reducing the metal consumption by decreasing the thickness of the otter.

FIG. 1 - FIG. Figure 4 shows the sequence of operations performed in the manufacture of ring forgings; in fig. 5 shows the action of stamping, clamping (locking) of die punching patterns and changing the shape of the blank to be stamped as a result of performing sequential punching techniques; in fig. 6 is a graph of average normal stresses on a punch, related to the deformation resistance of the sample material, on the magnitude of the underfill of acute punch angles and the thickness of the jumper under the punch at the first punching stage (for the prototype method and the proposed method).

The method is carried out as follows.

The heated piece cylindrical billet (Fig. 1), cut from the ingot with a wavy (like "chamomile) side of the top05

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besieged, they are upset to obtain a forging (FIG. 2), weighed, and then stamped in a die with detachable dies in two stages, resulting in a stamped workpiece (FIG. 3) with a thin bottom. Then, the otter is cut and the forging (Fig. 4) is ready for rolling.

The amount of under-preparation of the workpiece as a result of the first punching stage is determined by the size h (Fig. 5), and the thickness of the lintel under the forming punch is determined by the size Well. The relative diameter of the product obtained by stamping is determined by the parameter n Dy / D0, and the slope of the side surface is determined by the angle a.

The first punching stage is performed at the full amount of the technologically required RZ effort to lock the dies 1 and 2 (Fig. 5) by increasing the Punching Put force applied to the forming punch 35 and finish when the acute punch corners are underfilled by h (0.05-0, 1) R0 and the lintel thickness under the molding punch equal to Nu (0.2-0.3) H. At the second punching stage, deepen the resulting hole to an otter thickness equal to Hb 0.05-0.15 Ry by reducing the locking force dies without increasing pui stamping force. The thickness of the otter is finally corrected within the specified limits by the difference in mass of the forged head and product.

The substantiation of the limits on the sizes of H, Well and H регла regulated by the proposed method (Fig. 2) is closely related to its goals, which cause a positive effect (primarily due to an additional effect). To substantiate these limits, extensive experimental and theoretical research has been carried out on the technologically required efforts of stamping and locking the dies during stamping in dies with separable dies.

The regulated undersupply of acute punch angles by the value of Н (0.05-0.1) Ro and thickness fy (0.2-0.3) H of the jumper under the forming punch, achieved as a result of the first punching step, allow to obtain billet, suitable for the geometry of the outer surface for subsequent rolling. Under these conditions, in particular, the origin of the waviness of the side surface of the hogging (“chamomile), which is necessary for the normal operation of the roll mill, is eliminated. At the same time, the value of the thickness hy (0.2-0.3) N of the lintel for large-sized products without the use of the second stage would have resulted in large technological losses of metal with otter. At the same time, an attempt to reduce hu, in the framework of the first stage, would lead to a sharp decrease in the durability of the stamp or plastic deformation of the forming punch itself, which follows from the analysis of the results of the aforementioned studies. The effect of additional insertion of the molding punch in the second stage and a corresponding decrease in the bottom thickness from H y to hg (Fig. 5) is associated with a change in the stress and strain state of the material with a decrease in the locking force of the die. Compared with the known methods (for example, with open firmware) in the proposed method, at the second punching stage, the product form is not distorted from further insertion of the forming punch, since the contact of the dies with the workpiece along its outer surface is not disturbed at the second punching stage. This is the essence of the new additional effect associated with the mechanics of the interaction of the deformable workpiece with the tool on the surface of their

 contact.

Example. In the manufacture of an annular forging of a flange with an outer diameter of 1765 mm, an inner diameter of 1,400 mm, and a height of 280 mm, a cylindrical billet with a diameter of 586 mm and a wavy side surface (chamomile) with a height of 716 mm is upset to 275 mm. After weighing the deposited preform, it is stamped in a die with detachable dies in two stages. As a result of the first stage, a pre-stamped billet with an outer diameter of 980 mm and a height of 260 mm with a hole and jumper thickness equal to mm under the molding punch is obtained. The lack of filling in the sharp corners of the stamp is 5 mm. As a result of the second stage, the bottom thickness is reduced to an otter thickness equal to H {50.7 mm, calculated from the difference in the mass of the stamped billet and the final Q dimension. After punching, an otter is cut and the extruded billet is rolled to an outer diameter of 1765 mm, an internal diameter of 1400 mm and a height of 280 mm. Ring forging is ready.

Using the proposed method

The manufacture of large-sized ring forgings in comparison with the prototype method makes it possible to reduce the stamping and locking forces of the dies, increase the durability of the punch and reduce the metal consumption.

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Claims (1)

Invention Formula A method of manufacturing ring forgings, mainly large-sized, including the weighing of a cylindrical billet, its draft, extrusion by stamping in a closed die with separable dies, a deforming punch force, an otter cut and rolling, In order to increase die resistance by reducing the required deforming efforts and locking the dies during punching, as well as reducing the metal consumption by decreasing the otter thickness, the punching is carried out in two stages, the first of which is carried out at the full amount of technologically required locking force matrices and complete it upon reaching the underfill angle of the sharp corners of the punch 0.05-0.1 of the outer radius of the forging and the thickness of the lintel under the punch of 0.2-0.3 of the height of the forging, and in the second stage I deform t at the same magnification of the punch with a decrease in the locking force of the dies to obtain an otter thickness of 0.05-0.15 of the radius of the forging hole. figure 1 fig.Z FIG. 2 FIG. H FIG. five O123 4 h; h4, HH 5