SU1488087A1 - Method of producing axial symmetrical articles - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular, to the production of axisymmetric parts by face rolling. The purpose of the invention is to improve the quality of parts and increase productivity by creating an adjustable effort of lateral support to the outer surface of the deformable part of the workpiece from the side of the restriction roller. The change in the backpressure force is accomplished by moving the support roller at a rate of 0.5-0.75 of the rate of increase in the radius of the outer surface of the deformable part of the workpiece when rolling without backwater. The speed of movement of the limit roller is determined by the mathematical relationship. 4 il.

Description

The invention relates to the processing of metals by pressure, in particular to the production of axisymmetric parts by face rolling.

The aim of the invention is to improve the quality of the parts and increase the productivity of labor by creating an adjustable effort for the lateral support from the side of the restriction roller.

FIG. 1 shows a diagram of the initial stage of rolling; in fig. 2 - scheme of the intermediate stage of rolling; in fig. 3 - scheme of the final stage of rolling; in fig. 4 is a diagram explaining the approximation of the shape of the lateral surface of the rolled part without support to the calculation of the speed of movement of the limiting roller.

The method is implemented in a device consisting of an annular matrix 1 with a bar stock 2 installed inside it and an ejector 3 which simultaneously performs the function of an abutment. Outside the matrix is placed conical roll roller 4, the axis of which is angled to the axis of the workpiece. The roller 4 can progressively move along the axis of the workpiece 2 both in the direction of the matrix 1 and away from it. On

an axis parallel to the axis of the annular matrix 1, a freely rotating supporting roller 5 is disposed, which is mounted for movement both along the axis of the workpiece 2 and perpendicularly to it.

The rolling process is carried out as follows. The workpiece 2 (Fig. II is installed in the matrix 1 until the abutment into the ejector 3, the matrix with the workpiece is rotated, the roll roller 4 is brought to the free end of the workpiece, and the supporting roller 5 is attached to the side surface. Figure 2 is rotated. With the roller 4, at the same time the support roller is retracted from the deformation zone with a variable speed V and a variable force P.

The essence of the method lies in the fact that to the workpiece 2 in the rolling zone radial varying forces. A lateral backpressure creates a compressive stress exceeding the tangential tensile stress by moving the support roller 5 in a radial direction with a variable speed lower than the radius growth rate side surface of the part.

(L

4ib

CX) 00

about

00

In this way, favorable conditions for the deformation of the workpiece are created in the rolling zone during the whole process, which allows to deform low-plastic metals.

The speed of movement of the support roller 5 in the radial direction varies depending on the material of the workpiece being rolled, the angle of the roll, the temperature of the workpiece, the moment of rolling within

,

where Va is the growth rate of the radius of the side surface of the part without lateral support. The speed of movement of the supporting role

ka 5 is an addiction

,

where a is the backwater ratio, the specific

the value of which is determined experimentally in the range of values, 5-0.75. Wherein

V a / X

where Rx is the current radius of the flange;

RO is the radius of the original billet;

tx is the time for changing the radius of the flange.

The value of R is determined from the condition of constancy of the volume of the deformable part of workpiece 2. Since the free surface of the deformable part has a complex shape, it is approximated to the surface of a truncated cone with height hy and bases R and (Fig. 4).

Consequently

(R, + Ro + R.Ro)

, (75-0.5); y, o / (V3 | -0.75-1.5).

one.

Express time through the speed of movement of the roll roller 4 1 / „and the current height hy

ho-hy

Vn

receive:

Va RoVn--. (, 75-1.5).

PO - Pun

in this case, the speed of movement of the support roller 5 to create lateral support

(, 75-1.5).

In the process of face rolling, the tensile stresses at the periphery of the deformable part of the workpiece change due to a change in the contact friction conditions, the contact area and an increase in the radius

five

,

five

P

five

0

five

0

five

with

peripheral layers, so the force of the backwater should be variable.

Upon reaching the predetermined dimensions of the rollout part diameter, the movement of the support roller 5 is stopped, and the roll roller 4 and the support roller 5 are retracted to the initial position, the die 1 stops and the ejector 3 removes the rolled part.

Example. The billet is deformed from steel 20 with initial dimensions: mm, mm at the speed of movement of the roll roll, mm / s. The measured values of the growth rate of the diameter of the side surface of the deformable part of the workpiece without lateral support () are; initial 2.5 mm / s, final 8 mm / s. At the same time, cracks are observed on the outer surface.

Then, the same blank is processed with lateral support of the outer surface of its deformable part, first with a minimum (, 75) at the speed of the radial movement of the support roller at the beginning of the rolling 1.87 mm / s and at the end 6 mm / s. Cracks on the side of the product is not detected. When machining the workpiece with a further reduction in the backwater (, 75), cracks appear. The backwater is then increased to a value of 5. At the same time, at the beginning of rolling, the speed of movement in the radial direction of the support roller is 1.25 mm / s, and at the end of 4 mm / s, the quality of manufacture of the part is satisfactory. During the subsequent rolling with even greater support (, 5), sunsets and clips formed on the parts.

Claims (1)

Invention Formula The method of obtaining axisymmetric parts, including face rolling of the original billet in a rotating matrix using a roll roll set at an angle to the axis of the workpiece with the possibility of rotation and translational movement along this axis, as well as a restrictive roller installed with the possibility of free rotation and movement along and perpendicular the axis of the workpiece, in accordance with the speed of the radial movement of the outer side surface of the product being rolled, characterized in that, in order to increase product quality and performance by providing an adjustable lateral force backwater from the limiting roller, the latter is moved in a direction aerpen- Dikulja polar axis of the workpiece, at a speed lower than said speed of radial movement sheetable surface of the article, starting from the relationship ./ o-Vn: - (V3r- ° -0 75-1,5), / go -V the speed of movement of the limiting roller in the direction perpendicular to the axis of the workpiece; the backpressure coefficient, determined experimentally in the range of values 0.5 ... 0.75; radius of the original billet; - the speed of movement of the roll roll; - the initial height of the deformable part of the workpiece; - the current value of the height of the deformable part of the workpiece. FIG. Pi (G Phie.g Fia. H Phie. k