RU1779455C - Method for producing circular parts with deep external groove - Google Patents

Abstract

Usage: in the manufacture of ring parts such as rims of track rollers of tracked vehicles, booster housings of variable gearboxes, etc. SUMMARY OF THE INVENTION: Annular recesses are formed at the ends of the workpiece. Then, on the lateral forming surface of the workpiece, a trough profile is formed by transverse rolling. The formation of the gutter is carried out in one turn of the workpiece by rolls having different profile radii of the working sections. Profile radius of the first -. L. made equal to 0.2-0.35 profile radius of the last roll. The radii of the remaining rolls are selected from the condition that the specific pressures in the contact zones of all the rolls are equal. 1 tablet, 6 ill. sl c

Description

The invention relates to the processing of metals by pressure, in particular forging and stamping and rolling production, and can be used in the manufacture of ring parts such as rims of track rollers of tracked vehicles, boosters cases of variable speed gearboxes, and the like.

A known method of manufacturing parts with an annular groove, according to which the billet for rolling is obtained by casting, is made on the surface of its disk part by annular wave-like protrusions and depressions, and transverse rolling is carried out by pointed rods. external groove and decrease in effort on a roll

The disadvantage of this method is that significant metal lumps are maintained along the bottom and side walls of the trough, which increase the laboriousness of machining the parts and lose metal into the chips.

The closest technical solution to the proposed one as a prototype is a method of manufacturing parts with an annular groove on a cylindrical surface.

The disadvantage of this method is that the process is characterized by a significant duration and laboriousness, as well as an increased consumption of energy and metal.

The aim of the invention is to increase efficiency by reducing the complexity and energy intensity of the process.

The goal is achieved in that the groove profile is formed in one revolution of the workpiece by rolls with different profile radii of the working sections, while the radius of the first roll is made equal to 0.2-035

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the radius of the last roll, and the radii of the remaining rolls are selected from the condition that the specific pressure is equal in the contact zones of all the rolls.

The given quantitative interval of the profile radius of the working section of the first roll is due to the following data obtained during the experimental work on the rolling of ring parts with a deep outer groove of 38XC and 40XH2MA steels. It has been found that when the profile radius of the working section of the first roll is less than 0.2 (e.g. 0.15) of the profile radius of the last roll, an intensification of the rolling process is observed as a result of an increase in the rate of introduction of the first roll into the workpiece. However, after rolling 3-5 parts, the roll is intensively heated, softened, the edge of the roll is plastically deformed, and the roll quickly fails. The manufacture of the first roll with a profile radius of the working section of more than 0.35 (for example, 0.4) of the profile radius of the last roll causes a significant increase in its wear resistance, however, the speed of roll penetration into the workpiece decreases sharply, the rolling time increases, and the workpiece rolls on the mandrel those. an increase in the diameter of the hole, which is a defect.

The requirement to fulfill the profile radii of the working sections of the remaining rolls from the condition that the individual pressures are equal in the contact zones of all the rolls is due to the need for uniform deformation of the workpiece during rolling along the depth and width of the groove per revolution of the part. With this ratio of roll parameters, the process of forming the trough proceeds in the following sequence. The first roll is introduced and cuts the workpiece to a certain depth, depending on the deformation resistance of the workpiece material and the force applied to the roll; subsequent rolls selected from the condition of equal specific pressures in the contact zones with the workpiece provide an increase in the width of the trough, and the final roll calibrates the part to the required dimensions. Failure to comply with the condition that the specific pressures are equal in the contact zones of all the rolls leads to the formation of sunsets and other defects in the zone of the product trough.

In FIG. 1 shows an initial annular preform with end recesses; in FIG. 2 is a diagram of a process for transverse rolling a workpiece with an external trough on a three-roll mill; Fig. 3 - section AA

in FIG. 2; in FIG. 4 is a section BB in FIG. 2; in FIG. 5 is a sequence of shaping the trough with rolls with different profile radii of the working sections;

Fig. 6 is a rolled part with a deep outer groove.

In FIG. marked: B0, D0, hn - respectively, the rim thickness, outer diameter and web thickness of the original workpiece

0 for rolling; Di, D2 and hi are the outer and inner diameters of the annular recess and the web thickness in the recess zone; d

-diameter of the central hole in the workpiece; Pv is the force applied from the side of the roll to the deformable workpiece; Rz

- clamping force of the rolled billet with forming washers; p, ha, gr - respectively, the profile radii of the working parts of the first, second and final

0 rolls; Dn and Bp are the diameter and thickness along the coronal part of the product; b and I are the width and depth of the rolled trough; 1 - the first roll; 2 - deformable workpiece; 3 - mandrel; 4 - final roll; 5 - intermediate 5 intermediate roll; 6 - movable forming washer; 7 - stationary forming washer.

The proposed method of manufacturing ring parts with a deep outer

0 trough is implemented as follows.

Billets for rolling with a diameter of D0

578 mm. web thickness hn 54 mm and

the height of the coronal part В0 67 mm was dropped from the stack 38XC on the stamping hammer 5 МЧЧ 16Т. After trimming, flashing and flashing of the central hole of the billet was transferred to the KPS 500 three-roll cross-rolling mill line. The stamped billet (Fig. 1) was heated to a hot deformation temperature of 1180 ° C in a pusher gas furnace, cleaned of scale, installed on a mandrel, and clamped with molding washers with a force of 2MN and deformed by rolls with different profile radii of the working parts: first n, second G2 and final rn 14 mm (Figs. 3-5). The force exerted by the rolls on the workpiece Pb was 500 kN (Fig. 2). An annular part was rolled with an external diameter. Dn 560 mm, the height of the coronal part Ln 152 mm. having an external trough with a width of 34 mm and a depth of I 100 mm (Fig. 6). When conducting experimental work varied values

5 profile radii of the first and second rolls and the volume of the end annular recesses on the blanks for rolling.

It has been found that when performing end recesses in accordance with the prototype (20-30% of the volume of the deformable metalp), their significant filling with metal of the deformable billet under the action of the first and second rolls is noted. As a result, in the final stage of rolling under the action of the final roll, an oncoming metal flow appears, which leads to the formation of folds and sunsets along the bottom and walls of the gutter. Positive results on the quality of the parts being manufactured and the force parameters of deformation were achieved with the volume of end recesses equal to 35-40% of the volume of the deformable metal. In the process of experimental work, the workpieces and parts were measured after each technological transition and metallographic analysis was performed on templates cut from the parts. The experimental results are presented in the table.

Similar values were obtained during the transverse rolling of products with a diameter of Dp 558 mm, a thickness of the disk part hn 70 mm, a height of the coronal part Bn 94 mm, having an external trough 38 mm wide and 1 74 mm deep from 40XH2MA steel.

The proposed method in comparison with the prototype provides a reduction in metal consumption by 2-3%. a decrease in the complexity of manufacturing parts by 30-35% and the energy intensity of the process by 18-20%. The method can be used in tractor construction, in the manufacture of road machines and engine building

Claims (1)

The claims A method of manufacturing annular parts with a deep outer trough, in which annular recesses are formed at the ends of the workpiece, and then a trough profile is formed on the lateral forming surface of the workpiece, characterized in that, in order to increase efficiency by reducing the complexity and energy intensity of the process, the trough profile form in one revolution of the workpiece rolls with different profile radii of the working sections, while the profile radius of the first roll is made equal to O, 2 ... 0.35 profile radius of the last roll, and the radii of the remaining rolls are selected from the condition of equal specific pressures in the contact zones of all the rolls. The results of experiments on the manufacture of parts with an annular outer groove of the transverse rolling mill KPS 500 / $ No.l LT C ai g- t- n & "Cs Fig 4 1779% Figure 5